JP2008003580A - Protective film for polarizing plate, polarizing plate and liquid crystal display device - Google Patents

Abstract

Provided are a protective film for a polarizing plate and a polarizing plate suitable as a protective film for a polarizing film, which can maintain the quality of display images of a liquid crystal display device or the like over a long period of time.
A coating layer having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer is formed on one side of a transparent base film made of cellulose acylates, and the opposite side of the transparent base film A protective film for a polarizing plate, wherein at least a layer having a hard coat property is provided, and the moisture permeability at 60 ° C. and 95% relative humidity is 300 g / m ² · day or less.
[Selection figure] None

Description

  The present invention relates to a protective film for a polarizing plate having a coating layer on a transparent substrate film.

  Recently, liquid crystal display devices (hereinafter referred to as LCDs) are widely used in place of CRTs because of their thinness, light weight, and low power consumption. The demand for polarizing plates is rapidly increasing with the spread of LCDs. The field of use is also expanding from small products such as conventional calculators and watches to large products such as automotive instruments, PC monitors, and televisions.

  Since the display device is often in use for a long time at all times, the polarizing plate is susceptible to physical damage, and if it is damaged, the display image quality is impaired, so the mechanical strength of the polarizing plate is enhanced. Is desired. Furthermore, long-term durability has been demanded so that the image quality of the LCD does not deteriorate even when used for a long time in an environment having temperature and humidity changes.

  In the polarizing plate, a polarizing plate protective film (hereinafter sometimes referred to as a protective layer) is bonded to both sides or one side of a polarizing film having polarizing ability through an adhesive layer. As a material for the polarizing film, polyvinyl alcohol (hereinafter sometimes referred to as PVA) is mainly used. After the PVA film is uniaxially stretched, it is dyed with iodine or a dichroic dye or dyed. The polarizing film is formed by stretching and further crosslinking with a boron compound. As the protective layer, cellulose triacetate (hereinafter sometimes referred to as TAC) is mainly used because it is optically transparent and has low birefringence and a smooth surface.

  However, when cellulose triacetate is used as a protective layer, there has been a problem that unevenness of a display image may occur due to a change in the size of the polarizing film due to a change in temperature or humidity during long-term use. In addition, cellulose triacetate has a problem that it has a small surface hardness and is easily damaged.

  As a technique for solving these problems, it has been reported that a sheet made of norbornene resin is useful as a protective film (protective layer) for a polarizing film (Patent Document 1). However, a sheet made of norbornene-based resin has a problem that moisture permeability is sufficiently small and it is difficult to receive a change in humidity, but adhesion to a polarizing film is insufficient.

Moreover, it has been reported that the wet heat property of a polarizing plate improves by using the protective film which provided the layer containing a vinylidene chloride copolymer on the surface of a cellulose triacetate film (patent documents 2, 3). However, although wet heat properties are improved, since the surface hardness is low, further hard coat treatment is necessary, but there is no description regarding the hard coat. In Patent Documents 2 and 3, there is no description of moisture permeability, and the material and film thickness described in those patents do not have a sufficient moisture permeability reduction effect intended in the present invention.
Furthermore, there is a problem that generally a vinylidene chloride copolymer is easily colored by ultraviolet rays.

  In order to solve the above problems, a coating layer formed from a coating solution containing a polymer containing a chlorine-containing vinyl monomer, a compound having an ethylenic double bond, and a polymerization initiator is used. There have been reports of reducing moisture permeability, imparting hard coat properties, and suppressing coloring (Patent Document 4). However, the moisture permeability required in the present invention has not been achieved, and improvements in that aspect are necessary.

JP-A-10-101907 JP-A-62-161103 JP 2001-215331 A JP 2006-91656 A

  The objective of this invention is providing the protective film for polarizing plates suitable as a protective film of a polarizing film which can maintain the display image quality of displays, such as a liquid crystal display device, over a long period of time.

  As a result of intensive studies, the present inventors have a coating layer having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer on one side of the transparent substrate film and have a hard coat property on the opposite side. The inventors have found that the above-mentioned problems can be solved by a protective film for polarizing plates, and have completed the present invention.

That is, the present invention
(1) A coating layer having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer is formed on one side of a transparent substrate film made of cellulose acylates, and on the opposite side of the transparent substrate film A protective film for a polarizing plate, provided with at least a layer having a hard coat property and having a moisture permeability of 300 g / m ² · day or less at 60 ° C. and 95% relative humidity.
(2) The protective film for polarizing plate as described in (1) above, wherein the layer having hard coat properties has scattering properties.
(3) The protective film for a polarizing plate according to the above (1) or (2), wherein the chlorine-containing vinyl monomer is vinylidene chloride.
(4) The protective film for a polarizing plate according to any one of (1) to (3) above, wherein the coating layer has a thickness of 1 μm or more and 10 μm or less.
(5) The protective film for polarizing plates according to any one of the above (1) to (4), wherein the film thickness of the transparent substrate film is from 30 μm to 120 μm.
(6) The protective film for a polarizing plate according to any one of (1) to (5), wherein the cellulose acylates are cellulose acetate, cellulose acetate propionate, or cellulose acetate butyrate.
(7) The protective film for a polarizing plate according to any one of the above (1) to (6), which has an easy-adhesion layer between the transparent substrate film and the coating layer or on the surface of the coating layer. .
(8) The ultraviolet light absorber is contained in at least one of the transparent base film, the easy adhesion layer between the transparent base film and the coating layer, and the light transmittance at a wavelength of 380 nm is 5% or less, The protective film for a polarizing plate according to any one of the above (1) to (7), wherein the transmittance at a wavelength of 600 nm is from 80% to 100%.
(9) The protective film for a polarizing plate according to (8), wherein the ultraviolet absorber is any one of a benzotriazole compound, a benzophenone compound, and an ultraviolet absorbing polymer.
(10) The protective film for a polarizing plate as described in (9) above, wherein the ultraviolet absorber contains at least one ultraviolet absorber represented by the following general formula (1).

(Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a hydrogen atom or a monovalent organic group, and at least one of R ¹ , R ² and R ³ has a total carbon number of 4 Represents an unsubstituted branched or straight chain alkyl group of ˜20, and R ¹ , R ² and R ³ are different from each other.

(11) The protective film for a polarizing plate according to any one of (1) to (10), wherein the coating layer contains at least one kind of particles having a particle size of 0.5 to 12 μm.
(12) The above (1) to (1), wherein at least one of the coating layer and the easy-adhesion layer contains a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer and a hydrophilic polymer compound. (11) The protective film for polarizing plates in any one of.
(13) At least one of the surface of the transparent substrate film and the surface of the coating layer is subjected to at least one of corona discharge treatment and glow discharge treatment, according to any one of (1) to (12) above A protective film for polarizing plates.
(14) The coating composition used for forming the coating layer contains at least a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer and an organic solvent, and the organic solvent forms a transparent substrate film. The protective film for polarizing plates according to any one of (1) to (13), which contains a solvent that can swell or dissolve.
(15) A second coating layer having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer is further formed on the coating layer according to (14), and the second coating layer is formed. A protective film for a polarizing plate, wherein the coating composition used for forming is an aqueous dispersion of the polymer.
(16) The protective film for a polarizing plate according to any one of (1) to (15), wherein the coating layer contains at least one of an antioxidant and a metal complex.

(17) A coating composition for a coating layer containing a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer and a solvent capable of dissolving or dispersing the polymer is applied on a transparent substrate film; The method for producing a protective film for a polarizing plate according to any one of (1) to (16), wherein the coating layer is formed by drying.
(18) After the coating layer coating solution is applied and dried to form a coating layer, the second coating layer is applied onto the coating layer and dried to form the coating layer, and then wound up from one delivery. The method for producing a protective film for a polarizing plate according to (17), wherein each layer is continuously formed in the step.
(19) A polarizing film and a protective film for a polarizing plate as described in (1) to (7) above, or a protective film for a polarizing plate prepared by the production method as described in any of (17) or (18) above. And a polarizing film, wherein the polarizing film is located on the opposite side of the layer having a hard coat property with respect to the transparent substrate film.
(20) A liquid crystal display device using the polarizing plate according to (19).

A layer having a polymer containing a repeating unit derived from the chlorine-containing vinyl monomer of the present invention, wherein the coating layer is formed on one side of a transparent substrate film made of cellulose acylates and has a hard coat property on the opposite side The protective film for polarizing plate characterized by having a moisture permeability of 300 g / m ² · day or less at 60 ° C. and 95% relative humidity has a low moisture permeability, a large degree of polarization, A polarizing plate excellent in image quality can be produced. Further, by providing a layer having hard coat properties, a protective film for a polarizing plate having high pencil hardness and low colorability can be produced. If the protective film for polarizing plates of this invention is used, the display image quality of displays, such as a liquid crystal display device, can be maintained high quality over a long period of time.

  Hereinafter, the protective film for polarizing plates of the present invention will be described in detail.

A basic configuration of a preferred embodiment of the protective film for polarizing plate of the present invention will be described with reference to the drawings.
Here, FIG. 1 is a cross-sectional view schematically showing a preferred embodiment of the protective film for polarizing plate of the present invention, but the protective film for polarizing plate of the present invention is not limited to this form.
A protective film 1 for polarizing plate of the present invention shown in (1) of FIG. 1 includes a transparent base film 2 and a coating layer 3 having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer (hereinafter, It may be described as a coating layer), and it is preferable to provide a layer 4 having hard coat properties on the opposite surface of the transparent substrate film 2. It is also preferable to add internal scattering properties and surface scattering properties to the layer 4 having hard coat properties. Further, it is also preferable to provide a low refractive index layer on the hard coat layer 4 for the purpose of reducing the reflectance of the surface. It is also preferable from the viewpoint of adhesion between layers to have an easy adhesion layer between the transparent substrate film 2 and the coating layer 3 or at least one of the surfaces of the coating layer 3, and it is also preferable that the easy adhesion layer is composed of a plurality of layers. . It is also preferable to use any one of the easy-adhesion layers as an antistatic layer.

FIG. 2 is a cross-sectional view schematically showing a preferred embodiment of the polarizing plate of the present invention using the protective film for polarizing plate of the present invention, but the polarizing plate of the present invention is not limited to this embodiment.
A polarizing plate 5 of the present invention shown in FIG. 2 includes a polarizing plate protective film 1 of the present invention and a polarizing plate protective film 7 opposite to the polarizer 6. In the polarizing plate 5 of the present invention, the coating layer 3 is bonded to the polarizer 6. Although the protective film 7 for polarizing plates on the opposite side is not particularly limited, it is preferably a transparent substrate film made of cellulose acylates having no coating layer from the viewpoint of productivity.

FIG. 3 is a sectional view schematically showing a preferred embodiment of the liquid crystal display device of the present invention using the polarizing plate of the present invention using the liquid crystal display device, but the liquid crystal display device of the present invention is limited to this embodiment. It is not a thing.
The liquid crystal display device 8 of the present invention shown in FIG. The polarizing plate 5 of the present invention is preferably used on both sides as shown in FIG. 3, but it is also effective on one side. In the polarizing plate of the present invention, the opposite protective film 7 side is preferably attached to a liquid crystal cell via an adhesive.
An optical compensation film is also preferably used as the protective film on the opposite side of the polarizing plate of the present invention, and the optical compensation film is preferably a base film in which an optical compensation layer is formed on the base film. Moreover, it is also preferable to stick and use an optical compensation film on the opposite protective film through an adhesive.

[Coating layer]
The coating layer of the present invention is characterized by having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer (hereinafter also referred to as a chlorine-containing polymer).
In general, examples of the chlorine-containing vinyl monomer include vinyl chloride and vinylidene chloride. A chlorine-containing polymer can be obtained by copolymerizing these vinyl chloride or vinylidene chloride monomers with a monomer copolymerizable therewith.

[Monomer copolymerizable with chlorine-containing vinyl monomer]
Examples of the copolymerizable monomer include olefins, styrenes, acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, itaconic acid diesters, maleic acid esters, fumaric acid diesters, N- Examples thereof include monomers selected from alkylmaleimides, maleic anhydride, acrylonitrile, vinyl ethers, vinyl esters, vinyl ketones, vinyl heterocyclic compounds, glycidyl esters, unsaturated nitriles, unsaturated carboxylic acids and the like.

Examples of olefins include dicyclopentadiene, ethylene, propylene, 1-butene, 1-pentene, isoprene, chloroprene, butadiene, 2,3-dimethylbutadiene and the like.
Examples of styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropyl styrene, chloromethyl styrene, methoxy styrene, acetoxy styrene, chloro styrene, dichloro styrene, bromo styrene, trifluoromethyl styrene, vinyl. And benzoic acid methyl ester.

Specific examples of acrylic esters and methacrylic esters include the following.
Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, t-octyl acrylate, 2-methoxyethyl acrylate, 2-butoxyethyl acrylate, 2-phenoxyethyl acrylate, chloroethyl acrylate, Cyanoethyl acrylate, dimethylaminoethyl acrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, oct Methacrylate, benzyl methacrylate, cyanoacetoxyethyl methacrylate, chlorobenzyl methacrylate, sulfopropyl methacrylate, N-ethyl-N-phenylaminoethyl methacrylate, 2-methoxyethyl methacrylate, 2- (3-phenylpropyloxy) ethyl methacrylate, dimethylamino Phenoxyethyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, cresyl methacrylate, naphthyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, 3 -Chloro-2-hydro Cypropyl methacrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, diethylene glycol monoacrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, 5-hydroxypropyl Methacrylate, diethylene glycol monomethacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate.

Specific examples of vinyl ethers include the following.
Methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl ether, dimethylaminoethyl Vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthranyl ether .

Specific examples of the vinyl esters include the following.
Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl dimethyl propionate, vinyl ethyl butyrate, vinyl valerate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, Vinyl butoxy acetoacetate, vinyl phenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinyl cyclohexyl carboxylate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate.

  Acrylamides include acrylamide, methylacrylamide, ethylacrylamide, propylacrylamide, butylacrylamide, t-butylacrylamide, cyclohexylacrylamide, benzylacrylamide, hydroxymethylacrylamide, methoxyethylacrylamide, dimethylaminoethylacrylamide, phenylacrylamide, dimethylacrylamide, and diethyl. Examples include acrylamide, β-cyanoethyl acrylamide, and N- (2-acetoacetoxyethyl) acrylamide.

  Examples of methacrylamides include methacrylamide, methyl methacrylamide, ethyl methacrylamide, propyl methacrylamide, butyl methacrylamide, tert-butyl methacrylamide, cyclohexyl methacrylamide, benzyl methacrylamide, hydroxymethyl methacrylamide, methoxyethyl methacrylamide , Dimethylaminoethylmethacrylamide, phenylmethacrylamide, dimethylmethacrylamide, diethylmethacrylamide, β-cyanoethylmethacrylamide, N- (2-acetoacetoxyethyl) methacrylamide and the like.

  Further, acrylamides having a hydroxyl group can be used, and examples thereof include N-hydroxymethyl-N- (1,1-dimethyl-3-oxo-butyl) acrylamide, N-methylol acrylamide, N-methylol methacryl. Examples include amide, N-ethyl-N-methylol acrylamide, N, N-dimethylol acrylamide, N-ethanol acrylamide, N-propanol acrylamide, N-methylol acrylamide and the like.

  Examples of the itaconic acid diesters include dimethyl itaconate, diethyl itaconate, and dibutyl itaconate. Examples of maleic acid diesters include diethyl maleate, dimethyl maleate, and dibutyl maleate. Examples of the fumaric acid diesters include diethyl fumarate, dimethyl fumarate, dibutyl fumarate and the like.

  Examples of vinyl ketones include methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, and the like. Examples of the vinyl heterocyclic compound include vinyl pyridine, N-vinyl imidazole, N-vinyl oxazolidone, N-vinyl triazole, and N-vinyl pyrrolidone. Examples of glycidyl esters include glycidyl acrylate and glycidyl methacrylate. Examples of unsaturated nitriles include acrylonitrile and methacrylonitrile. Examples of N-alkylmaleimides include N-ethylmaleimide and N-butylmaleimide.

Examples of the unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid and the like, and further anhydrides such as fumaric acid, itaconic acid and maleic acid.
Two or more kinds of these copolymerizable monomers may be used.

  Examples of the chlorine-containing polymer in the present invention include JP-A-53-58553, JP-A-55-43185, JP-A-57-139109, JP-A-57-139136, JP-A-60. -235818, JP-A 61-108650, JP-A 62-256871, JP-A 62-280207, JP-A 63-256665, and the like.

  The ratio of the chlorine-containing vinyl monomer in the chlorine-containing polymer is preferably 50 to 99% by mass, more preferably 60 to 98% by mass, and most preferably 70 to 97% by mass. If the ratio of the chlorine-containing vinyl monomer is 50% or more, problems such as deterioration in moisture permeability do not occur, and if it is 99% or less, solubility in various solvents is obtained, which is preferable.

Chlorine-containing polymers are available from Asahi Kasei Chemicals Corporation and Kureha Chemical Corporation. The following are listed as available from Asahi Kasei Chemicals Corporation.
“Saran Resin R241C”, “Saran Resin F216”, “Saran Resin R204”, “Saran Latex L502”, “Saran Latex L529B”, “Saran Latex L536B”, “Saran Latex L544D”, “Saran Latex L549B”, “Saran Latex L551B” “Saran Latex L557”, “Saran Latex L561A”, “Saran Latex L116A”, “Saran Latex L411A”, “Saran Latex L120”, “Saran Latex L123D”, “Saran Latex L106C”, “Saran Latex L131A”, “ “Saran Latex L111”, “Saran Latex L232A”, “Saran Latex L321B”. Saran Resin F216 and R204 are more preferably used because they are soluble in ketone solvents (methyl ethyl ketone, cyclohexanone, etc.), and Saran Resin R204 is more preferable because it has high crystallinity and can lower the moisture permeability of the coating layer. Used.

The thickness of the coating layer is preferably 1 to 10 μm, more preferably 1.0 to 7 μm, and still more preferably 1.0 to 5 μm. If the thickness of the coating layer is equal to or less than the upper limit value, it is preferable because it has excellent low moisture permeability and does not cause adverse effects such as an increase in curling and deterioration of the brittleness of the coating layer. If the curl becomes too large, it will hinder subsequent processes for producing a polarizing plate, for example, a bonding process with a polarizing film and handling. Further, it is not preferable that the curl remains not only in the manufacturing process but also as the polarizing plate, which causes display unevenness in the LCD.
Therefore, in order to reduce the curl to such an extent that it does not occur or is practically not problematic, the upper limit of the coating layer thickness is preferably within the above range.
Moreover, it is preferable if the thickness of the coating layer is equal to or less than the above upper limit value because there are no adverse effects such as formation of a brittle film or easy coloring. On the other hand, the lower limit of the thickness of the coating layer is defined as a range that is more preferable than moisture resistance, and the effect of the present invention can be sufficiently exhibited by setting the above range. The coating layer consists of at least one layer, and two or more layers are also possible.

Regarding the thickness of the coating layer, in-plane uniformity is also required. The coating layer of the present invention is produced continuously by wet coating on a roll-shaped transparent substrate film having a width of 1 m or more and less than 3 m and a total length of 100 m or more and less than 10,000 m. However, the thickness distribution is preferably within ± 20% of the average thickness and within ± 10% of the average thickness in the plane in the width direction and the longitudinal direction. More preferably, the variation is within ± 5% with respect to the average thickness.
If the variation is within ± 20% with respect to the average thickness, the variation in the moisture permeability of the coating layer by the measurement method described later can be suppressed, and the display quality unevenness that is the effect of the present invention is further reduced.

  The haze of the coating layer is preferably 5% or less, more preferably 3% or less, and most preferably 1% or less. The ratio between the surface haze and the internal haze may be arbitrary, but the surface haze is more preferably 1% or less.

Since the coating layer of the present invention is often wet coated, the solvent used in the coating composition is an important factor. Requirements include sufficiently dissolving the above solute and being less likely to cause coating unevenness and drying unevenness during the coating to drying process.
In order to form a mixed region between the support and the coating layer, a solvent having a property of dissolving or swelling the base film is selected as the solvent of the coating solution for forming the coating layer. There is a need. This is because if such a solvent is used in the coating solution, the interface between the base film and the coating layer becomes unclear at the same time because the coating layer is formed while dissolving or swelling the support immediately after coating. The layer of the area | region which mixed the resin component of this and the resin component of the base film is formed.

Further, in order to achieve both control of the unevenness on the surface of the coating layer (reducing or flattening the unevenness) and the strength of the coating layer, at least a solvent that does not dissolve the transparent base film (for example, triacetylcellulose film) is used. It is preferable to mix one or more types, and it is more preferable that at least one of the solvents that dissolve the transparent substrate film has a higher boiling point than at least one of the solvents that do not dissolve the transparent substrate film.
Furthermore, it is preferable that the boiling point temperature difference between the solvent having the highest boiling point among the solvents that dissolve the transparent substrate film and the solvent having the highest boiling point among the solvents that do not dissolve the transparent substrate film is 25 ° C. or more, The temperature is more preferably 35 ° C. or higher, and further preferably 50 ° C. or higher.

When the base film is a cellulose acylate film, as a solvent having the property of dissolving or swelling the base film,
Ethers having 3 to 12 carbon atoms: Specifically, dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5- Trioxane, tetrahydrofuran, anisole, phenetole, etc.
Ketones having 3 to 12 carbon atoms: specifically, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, methylcyclohexanone, etc.
Esters having 3 to 12 carbon atoms: Specifically, ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, propion brewed ethyl, n-pentyl acetate, γ-butyrolactone, etc. ,
Organic solvent having two or more kinds of functional groups: Specifically, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-methoxyethanol, 2-propoxyethanol 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, N-methylpyrrolidone and ethyl acetoacetate.
These can be used alone or in combination of two or more. As a solvent for dissolving the transparent substrate film, tetrahydrofuran or a ketone solvent is preferable, and methyl ethyl ketone and cyclohexanone are particularly preferable.

As a solvent that does not dissolve the transparent substrate film (preferably triacetyl cellulose), methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-methyl- 2-butanol, cyclohexanol, isobutyl acetate, methyl isobutyl ketone, 2-octanone, 2-pentanone, 2-hexanone, 2-heptanone, 3-pentanone, 3-heptanone, 4-heptanone, toluene, propylene glycol monomethyl ether acetate Can be mentioned.
These can be used alone or in combination of two or more.

  The mass ratio (A / B) of the total amount (A) of the solvent that dissolves the transparent base film and the total amount (B) of the solvent that does not dissolve the transparent base film is preferably 20/80 to 100/0, and 30/70. ~ 100/0 is more preferable, and 40/60 to 100/0 is still more preferable.

In the present invention, when the chlorine-containing polymer is vinylidene chloride, it is preferable to use tetrahydrofuran as the main solvent.
Further, by selecting a copolymer of vinylidene chloride, it is more preferable that it can be dissolved in toluene, propylene glycol monomethyl ether acetate, a ketone solvent, etc., and toluene, a ketone solvent, etc. are used without using tetrahydrofuran. In particular, it is particularly preferable to use methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone when controlling the evaporation rate.
Further, it is also preferable to add the above solvent within a range where the solute dissolves in tetrahydrofuran. Further, it is also preferable to add the above solvent within a range where the solute dissolves in tetrahydrofuran. When tetrahydrafuran is used, a reducing substance such as p-cresol, resorcin, hydroquinone, ferrous salt, hindered phenol (for example, 2,6-di-tert-butyl-4-methylphenol) is used from the viewpoint of light stabilization. It is preferable to add 0.01 to 1% by mass in the coating solution. The coating layer is preferably used because it is effective in preventing coloring of the coating layer.
When the chlorine-containing polymer is supplied as a latex dispersion, water is preferably used as the main solvent. In the case of a latex dispersion, it is preferable to use a surfactant, a thickener or the like in combination.

Since the chlorine-containing polymer is decomposed and colored by heat, light, and ultraviolet light, it preferably contains a deterioration preventing agent. Examples of the deterioration preventing agent include an antioxidant, an ultraviolet absorber, and a certain metal complex.
Examples of the antioxidant include a chroman compound, a coumaran compound, a phenol compound (for example, hindered phenols), a hydroquinone derivative, a hindered amine derivative, and a spiroindane compound. In addition, compounds described in JP-A No. 61-159644, hydroxamic acid (such as AI to AV in JP-A-8-76311), and epoxy compounds are also effective.
Examples of ultraviolet absorbers include benzotriazole compounds (US Pat. No. 3,533,794, etc.), 4-thiazolidone compounds (US Pat. No. 3,352,681 etc.), benzophenone compounds (Japanese Patent Laid-open No. Sho 56-56). 2784, etc.) and other compounds described in JP-A Nos. 54-48535, 62-136641, 61-88256, and the like. Further, an ultraviolet absorbing polymer described in JP-A-62-260152 is also effective.
US Pat. Nos. 4,241,155, 4,245,018, columns 3-36, 4,254,195, columns 3-8, JP-A-62-174741 61-88256 (27) to (29), 63-199248, JP-A-1-75568, 1-74272 and the like. Examples of useful degradation inhibitors are Research Disclosure No. No. 17643, No. VII, I to J, i. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544 at page 527, ibid. 307105, page 872, ibid. No. 15162, and compounds described in JP-A-62-215272 (125) to (137).
Various metal stabilizers generally used for vinyl chloride resins are also preferably used, and metal soaps such as Zn and Ba and organotin stabilizers are particularly effective. Specific examples include various compounds described in "Practical Handbook for Additives for Plastics and Rubber" (published by Chemical Industry Co., Ltd.) (148) to (304).
It is also preferred that stearic acid such as lead, zinc and barium, silver salts, magnesium oxide and the like are used together. Moreover, you may use antioxidants as described in Paragraph [0013]-[0020] of Unexamined-Japanese-Patent No. 2004-359819. The above antioxidants, ultraviolet absorbers and metal complexes may be used in combination.
It is preferable to add 0.1 mass%-10 mass% of the said antioxidant, a ultraviolet absorber, and a metal complex with respect to a chlorine containing polymer. If the addition amount is 0.1% by mass or more, its ability to prevent deterioration will be sufficiently exhibited, and changes in various durability tests will not be seen or become very small. The addition amount of 10% by mass or less is preferable because the deterioration preventing ability is sufficient and there is no influence on other performance such as moisture permeability.

  It is also preferable to add particles to the coating layer in order to improve blocking resistance. The particles can be inorganic particles or organic resin particles. The average particle diameter of the particles is preferably 0.5 to 2 times, more preferably 0.8 to 1.5 times, and particularly preferably 0.9 to 1.2 times the film thickness of the coating layer. From the viewpoint of particle aggregation and sedimentation, 0.5 to 12 μm is preferable, 0.8 to 8.0 μm is more preferable, and 1.0 to 6 μm is further preferable. It is particularly preferable to design such that the ratio of particle diameters falls within the above range. Further, two or more kinds of organic resin particles having different particle diameters may be used in combination.

  The particles are preferably blended so as to be contained in the chlorine-containing polymer in an amount of 0.1 to 30% by mass, and blended so as to be contained in the chlorine-containing polymer in an amount of 0.2 to 5% by mass. It is more preferable, and it is particularly preferable that 0.25 to 1% by mass is contained in the chlorine-containing polymer. When the blending amount is 0.1% by mass or more and 30% by mass or less, the blocking resistance is good and the moisture permeability can be suppressed low, which is preferable.

The particle size distribution of the particles is preferably monodisperse particles because of ensuring transparency and homogeneity of the coated surface. For example, when a particle having a particle size of 20% or more than the average particle size is defined as a coarse particle, the ratio of the coarse particle is preferably 1% or less of the total number of particles, and preferably 0.1% or less. More preferred is 0.01% or less.
The particle size distribution of the resin particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution. Particles having a particle size distribution as described above are also effective means of classification after the preparation or synthesis reaction. By increasing the number of classifications or increasing the degree thereof, particles having a preferable distribution can be obtained. it can.
It is preferable to use a method such as an air classification method, a centrifugal classification method, a sedimentation classification method, a filtration classification method, or an electrostatic classification method for classification.

  When applying a coating layer containing a chlorine-containing polymer on a transparent substrate film, if inorganic particles are used to improve anti-blocking properties, the type is particularly limited as long as the above particle size and content are satisfied. However, examples of the fine particles include silica powders such as silicia (manufactured by Fuji Silysia), Mizukaseal (manufactured by Mizusawa Chemical Co., Ltd.), and dip seals (manufactured by Nippon Silica Industry).

When using particles for improving blocking resistance, organic resin particles can also be used. From the viewpoint of sedimentation in the coating solution, the specific gravity is lighter than that of the silica powder, so that it is preferably used. As the organic resin particles, plastic beads are preferable, and those having particularly high transparency and a refractive index difference from the chlorine-containing polymer of 0.001 or more and 0.3 or less are preferable.
The type of the organic resin particles is not particularly limited as long as the above particle diameter and content are satisfied. As the organic resin particles, crosslinked polymethyl methacrylate particles (refractive index 1.49), crosslinked poly (acryl-styrene) copolymer particles ( 1.54), melamine resin particles (refractive index 1.57), polycarbonate particles (refractive index 1.57), polystyrene particles (refractive index 1.60), cross-linked polystyrene particles (refractive index 1.61), poly Vinyl chloride particles (refractive index 1.60), benzoguanamine-melamine formaldehyde particles (refractive index 1.68), etc. are used.
Among the organic resin particles, crosslinked polystyrene particles, crosslinked polymethylmethacrylate particles, and crosslinked poly (acryl-styrene) particles are preferably used.

  Here, the refractive index of the chlorine-containing polymer can be quantitatively evaluated by directly measuring it with an Abbe refractometer or by measuring a spectral reflection spectrum or a spectral ellipsometry. The refractive index of the organic resin particles is determined by measuring the turbidity by dispersing an equal amount of the organic resin particles in a solvent in which the refractive index is changed by changing the mixing ratio of two types of solvents having different refractive indexes. Is measured by measuring the refractive index of the solvent with an Abbe refractometer.

Examples of the method for producing the organic resin particles according to the present invention include a suspension polymerization method, an emulsion polymerization method, a soap-free emulsion polymerization method, a dispersion polymerization method, a seed polymerization method and the like, and may be produced by any method. .
These production methods are described, for example, in “Experimental Methods for Polymer Synthesis” (Takayuki Otsu and Masaaki Kinoshita, Chemical Dojinsha), pages 130 and 146 to 147, “Synthetic Polymers”, Vol. 1, p. 246-290, 3rd volume, p. 1 to 108, etc., and Japanese Patent Nos. 2543503, 3508304, 2746275, 3521560, 3580320, and Japanese Patent Laid-Open No. 10-1561. Reference can be made to methods described in JP-A No. 7-2908, JP-A No. 5-297506, JP-A No. 2002-145919, and the like.

  It is also preferable to add additives other than particles to the coating layer in order to improve blocking resistance. For example, it is also preferable to add 0.2 to 5.0 parts of a wax emulsion such as paraffin wax (manufactured by Nippon Seiwa), behenic acid (manufactured by Nippon Oil & Fats), stearic acid (manufactured by Nippon Oil & Fats). It is also preferable to use a modified wax as described in paragraphs [0012] to [0016] of JP-A-9-143419. Furthermore, in order to increase the adhesion between the coating layer containing the chlorine-containing polymer and the transparent substrate film, and other layers, isocyanate adhesives such as Coronate L (made by Nippon Polyurethane) and Takenate A-3 (Takeda Pharmaceutical) It is also preferable to add 0.1 to 1.0 part of the agent with respect to the chlorine-containing polymer. If the addition amount is not increased more than 0.1 part, the effect of improving the adhesion cannot be obtained, and if the addition amount is not more than 1.0 part, the stability to light is remarkably deteriorated.

[Light resistance test]
JIS K 5600-7-5 “Paint General Test Method—Light Resistance—” describes that a light resistance test is performed using a xenon lamp as a light source.
In the present invention, a xenon lamp light source is used as the light resistance test, the irradiance is 100 ± 25 W / m ² (wavelength: 310 to 400 nm), the test chamber temperature is 35 ± 5 ° C., the black panel temperature is 50 ± 5 ° C., the relative humidity. JIS K 5600-7-5 is adopted under the condition of 65 ± 15%.

[Evaluation of light resistance]
In the present invention, the degree of change in appearance (color of transmitted light) was evaluated as a measure for measuring the light resistance of the protective film for polarizing plate.
The inventors of the present invention quantitatively measure and display these as numerical values to be displayed by the following mathematical formula (1) (color difference ΔE * ab value in the CIE1976L * a * b * color space). ) Was found to be appropriate.
For example, if the transparency deteriorates (the transmittance decreases), ΔL * increases, and as a result, the transmitted light color change amount ΔE * ab value increases.
Further, if the color of the transmitted light changes, Δa * and Δb * increase, and the transmitted light color change ΔE * ab value also increases. The correspondence between the transmitted light color change ΔE * ab value and the sensory evaluation results for the appearance change is almost as shown in Table 1 below. The color change is the degree of change in the appearance of the protective film for polarizing plates, that is, light resistance. It can be seen that this is an appropriate evaluation characteristic that correctly reflects
The transmitted light color change ΔE * ab value is preferably 4.5 or less, more preferably 3.0 or less, and even more preferably 2.0 or less. By setting the transmitted light color change ΔE * ab value to 4.5 or less, high light resistance can be achieved.

Formula (1): ΔE * ab = [(ΔL *) ² + (Δa *) ² + (Δb *) ² ] ^1/2
ΔL * = L1 * -L2 *
Δa * = a1 * −a2 *
Δb * = b1 * −b2 *

(In the formula, L1 *, a1 *, b1 *, L2 *, a2 *, and b2 * represent the color of the transmitted light of the CIE standard light source C of the protective film for polarizing plate, and the CIE 1976 L * a * b * color space. The L * value, a * value, and b * value of L1 *, a1 *, and b1 * are L * values of the protective film for a polarizing plate before the light resistance test is performed. Value, a * value, and b * value, and L2 *, a2 *, and b2 * are the L * value, a * value, and b * of the protective film for polarizing plate after the light resistance test was performed. Represents the value.)

  In the above mathematical formula (1), L1 *, a1 *, b1 *, L2 *, a2 *, and b2 * are values calculated in detail by the following method.

[Calculation of L1 *, a1 *, and b1 *]
Using a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation), the spectral transmittance is measured in a wavelength region of 380 to 780 nm.
Next, the obtained spectral transmittance data and the spectral distribution data of the CIE C standard light source are multiplied for each wavelength to obtain spectral transmitted light for the C light source.
The LIE *, a *, and b * values of the CIE 1976 L * a * b * color space in the CIE standard light source C are calculated from the obtained spectral transmission light data under the standard light, and L1 *, a1 *, and Let b1 *.

[Calculation of L2 *, a2 *, and b2 *]
After carrying out a light resistance test for 25 hours in accordance with JIS K 5600-7-5 using a light resistance test apparatus (super xenon weather meter SX120 type (long life xenon lamp), manufactured by Suga Test Instruments Co., Ltd.) L * value, a * value, and b * value calculated from values measured in the same manner using a photometer (UV-3150, manufactured by Shimadzu Corporation) are set as L2 *, a2 *, and b2 *. .

The mixed region formed after coating the coating layer is the solid content concentration of the coating layer coating solution, the solvent type, the solvent composition, the type of ionizing radiation curable compound, the additive, the type of transparent substrate film to which the coating layer is applied. It is affected by various conditions such as the coating amount of the coating layer coating solution, drying conditions, and curing conditions. In the present invention, the above conditions are not particularly limited as long as a mixed region is formed between the transparent base film and the coating layer and there is an effect of suppressing interference unevenness of the coating layer.
The layer thickness of the mixed region is preferably in the range of 0.2 to 10 μm, more preferably 0.3 to 7 μm, and still more preferably 0.5 to 5 μm. When the thickness of the layer in the mixed region is smaller than this range, the effect of suppressing the interference unevenness of the coating layer is small, and when it is larger than this range, the strength of the coating layer tends to decrease. The thickness of the layer in the mixed region was obtained by cutting the cross section of the protective film for polarizing plate using a microtome, observing the cross section using the scanning electron microscope (S-570, manufactured by Hitachi, Ltd.) in the reflected electron mode, and taking the photograph. The layer thickness of the mixed region can be obtained from the photograph.

[Transparent substrate film]
As the transparent base film used in the present invention, a cellulose acylate film is used because it is optically uniform, has a smooth surface, and has good secondary workability in producing a polarizing plate. .
The cellulose acylate used in the present invention is an aliphatic carboxylic acid ester or aromatic carboxylic acid ester having about 2 to 22 carbon atoms, and is particularly preferably a lower fatty acid ester of cellulose.
The lower fatty acid in the lower fatty acid ester of cellulose means a fatty acid having 6 or less carbon atoms. For example, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate phthalate, etc. Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate as described in JP-A-8-231761, U.S. Pat. No. 2,319,052 can be used. Alternatively, esters of aromatic carboxylic acids and cellulose described in JP-A Nos. 2002-179701, 2002-265639, and 2002-265638 are also preferably used. Among the above description, the lower fatty acid esters of cellulose that are particularly preferably used are cellulose triacetate and cellulose acetate propionate described later. These cellulose esters can be used as a mixture.

The degree of substitution (DS) of cellulose acylate means the ratio of acylation of three hydroxyl groups present in the cellulose structural unit (glucose having β1 → 4 glycosidic bonds). The degree of substitution can be calculated by measuring the amount of bound fatty acid per unit weight of cellulose. The measurement method is performed according to ASTM-D817-91.
The cellulose acylate of the present invention balances the humidity dependence of the retardation and the dimensional stability by appropriately balancing the hydrophobicity of the acyl group and the hydrophilicity of the hydroxyl group. That is, if the alkyl chain in the acyl group is too short on average and / or the hydroxyl group ratio is too high, the humidity dependency of retardation will increase. Also, if the alkyl chain in the acyl group is too long on average and / or if the hydroxyl group ratio is too high, the Tg decreases,
Dimensional stability will deteriorate.
Therefore, the cellulose triacetate preferably used in the present invention preferably has a degree of acetylation of 2.83 or more and 2.91 or less and no other acyl group having 3 or more carbon atoms. The degree of acetylation is more preferably 2.84 or more and 2.89 or less.

In addition to cellulose triacetate, a preferred cellulose ester has an acyl group having 2 to 4 carbon atoms as a substituent, when the substitution degree of acetyl group is X and the substitution degree of propionyl group is Y, the following formula ( It is a cellulose ester satisfying a) and (b) simultaneously.
Formula (a) 2.6 ≦ X + Y ≦ 2.9
Formula (b) 0 ≦ X ≦ 2.5
Among them, cellulose acetate propionate (total acyl group substitution degree = X + Y) satisfying 1.9 ≦ X ≦ 2.5 and 0.1 ≦ Y ≦ 0.9 is preferable. The portion not substituted with an acyl group usually exists as a hydroxyl group. These can be synthesized by known methods.

  30-120 micrometers is preferable and, as for the thickness of a transparent base film, 40-80 micrometers is more preferable. If the thickness of the base film is equal to or greater than the lower limit, problems such as a decrease in film strength are unlikely to occur. If the thickness is equal to or less than the upper limit, the weight increases excessively, particularly for large televisions of 20 inches or more. It is preferable because adverse effects such as disadvantages are less likely to occur.

[UV absorber]
It is preferable to contain one or more kinds of ultraviolet absorbers represented by the following general formula (1) in any of the transparent substrate film, coating layer, easy-adhesion layer, and hard coat layer of the present invention.
The average value of the octanol / water partition coefficient (hereinafter referred to as logP) represented by the following formula (A) relating to the ultraviolet absorber (hereinafter referred to as average logP) and the acylation degree DS of cellulose acylate are represented by the following formula (B). It is more preferable that the cellulose acylate film satisfying the above is used as the transparent substrate film.

(In the formula (1), R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a hydrogen atom or a monovalent organic group, and at least one of R ¹ , R ² and R ³ ) Represents an unsubstituted branched or straight chain alkyl group having 4 to 20 carbon atoms, and R ¹ , R ² and R ³ are different from each other.

(In the formula (A), _{W n} represents the mass fraction of the n-th ultraviolet absorber, _{(logP) n} represents a logP of n-th ultraviolet absorber)

      5.0 × DS−6.7 ≦ average log P ≦ 5.0 × DS−5.1 Formula (B)

The average value of logP of the ultraviolet absorbent used in the present invention is (5.0 × DS−6.7) or more and (5.0 × DS−5.1) or less, and (5.0 × DS-6). .5) and (5.0 × DS-5.2) or less are preferable. When the average value of logP is too large, the surface shape is deteriorated, and when the average value of logP is too small, the retention property of the ultraviolet absorbent under high temperature and high humidity is deteriorated. Moreover, the compound represented by General formula (1) has an absorption maximum in the wavelength range of 330-360 nm.

The ultraviolet absorber used in the present invention preferably has a molecular weight of 250 to 1000 from the viewpoint of volatility. More preferably, it is 260-800, More preferably, it is 270-800, Most preferably, it is 300-800. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.
It is preferable that the ultraviolet absorber does not evaporate during the dope casting for producing the cellulose acylate film, the drying process, the coating layer, the easy-adhesion layer, the hard coat layer, and the like, and the drying process.
From the viewpoint of protecting the coating layer, the UV absorber additive layer should be added to the layer having a hard coat property on the surface side of the coating layer and the undercoat layer between the coating layer and the layer having the hard coat property. From the viewpoint of protecting each member of the liquid crystal display device, it is preferably added to any layer of the protective film for polarizing plate of the present invention including the transparent substrate film.

(Compound addition amount)
The addition amount of the ultraviolet absorber used in the present invention described above is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on cellulose acylate. It is especially preferable that it is 2-3 mass%.
When adding to a coating layer, an easily bonding layer, a hard-coat layer, etc., it is preferable that it is 0.01-10 mass% with respect to the total solid, and it is more preferable that it is 0.1-5 mass%. The content is particularly preferably 0.2 to 3% by mass.
(Method of compound addition)
The timing of adding these ultraviolet absorbers may be any time during the dope and coating layer preparation process, or may be performed at the end of the dope and coating layer preparation process.

Next, the ultraviolet absorber represented by the general formula (1) will be described in detail.
R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a hydrogen atom or a monovalent organic group, and at least one of R ¹ , R ² and R ^{3 is} a C 4-20 It represents a substituted branched or straight chain alkyl group, and R ¹ , R ² and R ³ are different from each other. Examples of the substituent include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methyl, ethyl, iso-propyl, tert-butyl, n -Octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 carbon atoms). -8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 carbon atoms). -8, for example, propargyl, 3-pentynyl, etc.), an aryl group (preferably having 6 to 30 carbon atoms, More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, and examples thereof include amino, methylamino, dimethylamino, diethylamino, dibenzylamino and the like.

An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably C6-C20, More preferably C6-C16, Most preferably C6-C12, for example, phenyloxy, 2-naphthyloxy, etc.), acyl groups (preferably C1-C1) 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, and more). Preferably it has 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl or ethoxycarbonyl. An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, such as phenyloxycarbonyl). An acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetoxy and benzoyloxy), an acylamino group (preferably having a carbon number) 2 to 20, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetylamino, benzoylamino, etc.), an alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms. An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino). ), A sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methanesulfonylamino and benzenesulfonylamino). A sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl, etc. ), A carbamoyl group (preferably having 1 to 20 carbon atoms, More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl etc. are mentioned. ), An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, ethylthio, etc.), an arylthio group (preferably carbon 6 to 20, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and the like, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably carbon atoms). 1 to 16, particularly preferably 1 to 12 carbon atoms such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably carbon atoms). 1 to 12, for example, methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably having 1 to 1 carbon atoms) 0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, More preferably, it has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include diethyl phosphoric acid amide and phenyl phosphoric acid amide), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, Chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 and the hetero atom includes, for example, a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, an imidazoli , Pyridyl, quinolyl, furyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), a silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably Are those having 3 to 24 carbon atoms, and examples thereof include trimethylsilyl and triphenylsilyl). These substituents may be further substituted.
Further, when there are two or more substituents, they may be the same or different, and may be connected to each other to form a ring if possible, but at least one of R ¹ , R ² and R ³ is It represents an unsubstituted branched or straight chain alkyl group having 4 to 20 carbon atoms in total, and R ¹ , R ² and R ³ are different from each other.

R ¹ and R ³ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably an alkyl group having 1 to 12 carbon atoms (preferably Is carbon number 4-12).

R ² is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, or a halogen atom, more preferably a hydrogen atom or an alkyl group. Group, aryl group, alkyloxy group, aryloxy group and halogen atom, more preferably hydrogen atom and alkyl group having 1 to 12 carbon atoms, particularly preferably hydrogen atom and methyl group, most preferably hydrogen atom. It is.

R ⁴ and R ⁵ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and a halogen atom, and particularly preferably a hydrogen atom and a chlorine atom.

  Specific examples of the compound represented by formula (I) are given below, but the present invention is not limited to the following specific examples.

  Examples of other ultraviolet absorbers preferably used in the present invention include compounds described in paragraphs [0123] to [0248] of JP-A-2006-282929.

[Protective film for polarizing plate]
As for the protective film for polarizing plates of this invention, the coating layer is formed on the transparent base film, and the thickness of a coating layer is 1.1-10 micrometers, Preferably it is 2-8 micrometers. If the thickness of the coating layer is equal to or less than the upper limit value, it is preferable because it has excellent low moisture permeability and does not cause adverse effects such as increased curl. If the curl becomes too large, it will hinder subsequent processes for producing a polarizing plate, for example, a bonding process with a polarizing film and handling. In addition to the manufacturing process, the remaining curl as a polarizing plate is not preferable because it causes display unevenness in the LCD. Accordingly, the upper limit of the thickness of the coating layer is preferably within the above range in order to reduce the curl to such an extent that it does not occur or is practically unproblematic. On the other hand, the lower limit of the film thickness is defined by a range more preferable than physical properties such as water permeability and pencil hardness, and is preferably 1.1 μm or more. The coating layer consists of at least one layer, and two or more layers are also possible.

Next, the moisture permeability will be described in detail.
The measurement method of moisture permeability is “Polymer Physical Properties II” (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285-294: Measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) Can be applied as appropriate.

[Measurement method 1 of moisture permeability]
70 mmφ film samples according to the present invention were each conditioned at 60 ° C. and 95% RH for 24 hours, and the moisture content per unit area was calculated from the mass difference before and after humidity adjustment according to JIS Z-0208 (g / m ² ). did. The moisture permeability of a commercially available cellulose acetate film measured by the above measurement method is generally 80 μm in thickness and 1400 to 1500 g / m ² · day under the above conditions. The upper limit of the water vapor transmission rate of the protective film for polarizing plate of the present invention is preferably 300 g / m ² · day or less, and more preferably 150 g / m ² · day or less. If the moisture permeability is higher than the above upper limit value, the effect of reducing the occurrence of unevenness in the display image due to the change in the size of the polarizing film due to the change in temperature and humidity during low-term use is low. The lower limit is not particularly limited, but is preferably 20 g / m ² · day or more, more preferably 30 g / m ² · day or more from the viewpoint of productivity during polarizing plate processing. Therefore, the range of 30 to 150 g / m ² · day is most preferable.
Within this range, the performance (polarization degree, single plate transmittance) as a polarizing plate is not deteriorated, and unevenness of the display image is caused by changes in the size of the polarizing film due to changes in temperature and humidity during long-term use. Can be prevented from occurring. It is practically useful.

[Measurement method 2 of moisture permeability]
In the present invention, the moisture permeability was calculated according to JIS Z-0208, except that the humidity control condition was changed to 60 ° C. and 95% RH. At this time, the operation of taking out and weighing the cup placed in the thermo-hygrostat at an appropriate time interval is repeated, and the increase in mass per unit time is obtained with two successive weighings, and it becomes constant within 5%. The evaluation continued until. Moreover, in order to exclude the influence by the moisture absorption etc. of a sample, the blank cup which does not put a hygroscopic agent was measured, and the value of moisture permeability was correct | amended.

[Measurement method 3 of moisture permeability]
A measurement method called a mocon method is also preferably used for measuring moisture permeability. In the present invention, the moisture permeability by the Mocon method was measured and calculated with a PERMARTRAN-W3 / 33 type water vapor permeability measuring device manufactured by Mocon under the conditions of 40 ° C. and a relative humidity of 90% RH.

  The cured coating layer may be composed of a single layer or a plurality of layers, but is preferably a single layer that is simple in the production process. The single layer in this case refers to a coating layer formed of the same composition, and may be formed by a plurality of coatings as long as the composition after coating and drying has the same composition. On the other hand, the term “multiple layers” refers to the formation of a plurality of compositions having different compositions.

  In the present invention, fine particles may be added to the coating layer forming coating solution. By adding fine particles, effects such as improved hardness, improved adhesion to a transparent substrate film, and reduced moisture permeability can be obtained.

[Fine particles]
As the fine particles, any of inorganic fine particles, organic fine particles, and organic-inorganic composite fine particles can be used. Examples of the inorganic fine particles include silicon dioxide particles, titanium dioxide particles, zirconium oxide particles, aluminum oxide particles, antimony oxide particles, and indium oxide particles.

  In general, the inorganic fine particles may easily form aggregates or cracks in the coating layer after curing, simply by mixing. In the present invention, in order to increase the affinity between the inorganic fine particles and the organic component, the surface of the inorganic fine particles can be treated with a surface modifier containing an organic segment.

  The filling amount of the fine particles is preferably 2 to 40% by volume, more preferably 3 to 30% by volume, and most preferably 5 to 30% by volume with respect to the volume of the coating layer after filling.

  An inorganic layered compound can also be added to the coating layer forming coating solution. As the layer compound, synthetic mica and synthetic smectite are preferably used. Specific examples of the synthetic mica include “Micro Mica MK-100”, “Micro Mica MK-200”, “Micro Mica MK-300”, “Somasif ME-100”, “Somasif MAE”, manufactured by Corp Chemical Co., Ltd. "Somasif MTE", "Somasif MEE", "Somasif MPE", etc. are listed, and synthetic smectites include "Lucentite SWN", "Lucentite SAN", "Lucentite STN", "Lucentite SEN", "Lucentite" Tight SPN "and the like. Synthetic smectite, “Lucentite STN”, and “Lucentite SPN” are preferred from the viewpoint of transparency of the coating layer after curing and dispersibility in the coating liquid for forming the coating layer.

Moreover, it is preferable that the protective film for polarizing plates of this invention is substantially colorless. “Substantially colorless” means that the absolute values of a ^* and b ^* expressed in the L ^* , a ^* , and b ^* color system are 3.0 or less. 2.5 or less is more preferable, and 2 or less is particularly preferable. Substantially colorless, it is preferable because the color tone is neutral gray when used as a polarizing plate, and troubles such as troubles in color display are not caused.

  The protective film for polarizing plate in the present invention preferably has a value when curl is expressed by the following formula (2) in the range of −15 to +15, more preferably in the range of −12 to +12. More preferably, it is −10 to +10. In this case, the measurement direction of the curl in the sample is measured in the conveyance direction of the base material in the case of application in a web form.

Carl = 1 / R ... Formula (2)
In the above mathematical formula (2), R represents a radius of curvature (m).

It is preferable that the curl value is in the above range and the curl is small. If it is in said range, a crack and film | membrane peeling will not occur by manufacture of a film which has a coating layer, a process, and handling in a market, and it is preferable. It is possible to reduce the curl within the above range and increase the surface hardness by setting the volume shrinkage ratio before and after curing to 15% or less.
The curl is measured using the curl measurement template of Method A in “Measuring Method of Curling of Photographic Film” of JIS K-7619-1988. The measurement conditions are 25 ° C., humidity 60% RH, and humidity control time 10 hours.
Here, “curl plus” means a curl in which the coating layer coating side of the film is inside the curve, and “minus” means a curl in which the coating side is outside the curve.
The transmittance of the protective film for polarizing plate of the present invention using the ultraviolet absorber represented by the general formula (1) is preferably 5% or less at a wavelength of 380 nm, and preferably 80% or more and 100% or less at a wavelength of 600 nm. . If the transmittance at a wavelength of 380 nm is 5% or less, absorption in the visible region does not occur, and thus the color of the polarizing plate protective film does not occur, which is preferable. If the transmittance at a wavelength of 600 nm is 80% or more, the transmittance in the visible region is high, and contrast reduction when used in a liquid crystal display device does not occur.

  In the protective film for polarizing plate of the present invention, when only the humidity is changed from 80% RH to 10% RH based on the curl measurement method, the absolute value of the difference between the curl values is 24 to 0, and further 15 It is preferable to be in the range of ˜0, particularly 8˜0. This is a property related to handling properties, peeling, and cracking when a polarizing plate protective film is attached under various humidity conditions.

The cracking resistance of the protective film for polarizing plate of the present invention is preferably 30 mm or less, more preferably 25 mm or less, with a radius of curvature at which cracking occurs when the coating layer coating side is rolled outward. Most preferably, it is 20 mm or less.
About the crack of an edge part, it is preferable that there is no crack or the length of a crack is less than 1 mm on average. This crack resistance is an important characteristic for preventing crack defects in handling such as coating, processing, cutting, and sticking of a film having a coating layer.

[Layer with hard coat properties]
The film of the present invention is preferably provided with a layer having a hard coat property (hereinafter sometimes referred to as a hard coat layer) on one surface of the transparent support in order to impart the physical strength of the film. .
Preferably, a low refractive index layer is provided thereon, and more preferably, an intermediate refractive index layer and a high refractive index layer are provided between the hard coat layer and the low refractive index layer to constitute an antireflection film.
The hard coat layer may be composed of a laminate of two or more layers.

  The refractive index of the hard coat layer in the present invention is preferably in the range of 1.48 to 2.00, more preferably 1.49 to 1, from the optical design for obtaining an antireflection film. .90, more preferably 1.50 to 1.80. In the present invention, since there is at least one low refractive index layer on the hard coat layer, if the refractive index is too small, the antireflection property is lowered, and if it is too large, the color of the reflected light tends to be strong. is there.

From the viewpoint of imparting sufficient durability and impact resistance to the film, the thickness of the hard coat layer is usually about 0.5 μm to 50 μm, preferably 1 μm to 20 μm, more preferably 2 μm. ˜15 μm, most preferably 3 μm to 10 μm.
The strength of the hard coat layer is preferably 2H or more, more preferably 3H or more, and most preferably 4H or more in the pencil hardness test.
Furthermore, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound. For example, it may be formed by coating a coating composition containing an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer on a transparent support and subjecting the polyfunctional monomer or polyfunctional oligomer to a crosslinking reaction or a polymerization reaction. it can.
The functional group of the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable.

In place of or in addition to the monomer having a polymerizable unsaturated group, a crosslinkable functional group may be introduced into the binder. Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer having a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used.
That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition. These binders having a crosslinkable functional group can form a crosslinked structure by heating after coating.

  The hard coat layer contains matte particles having an average particle diameter of 1.0 to 10.0 μm, preferably 1.5 to 7.0 μm, such as inorganic compound particles or resin particles, for the purpose of imparting internal scattering properties. May be.

  For the purpose of controlling the refractive index of the hard coat layer, a high refractive index monomer, inorganic particles, or both can be added to the binder of the hard coat layer. In addition to the effect of controlling the refractive index, the inorganic particles also have the effect of suppressing cure shrinkage due to the crosslinking reaction. In the present invention, a polymer formed by polymerizing the polyfunctional monomer and / or the high refractive index monomer after the hard coat layer is formed, and the inorganic particles dispersed therein are referred to as a binder.

The haze of the hard coat layer varies depending on the function imparted to the antireflection film.
In the case where the sharpness of the image is maintained, the reflectance of the surface is suppressed, and the light scattering function is not imparted inside and on the surface of the hard coat layer, the haze value is preferably as low as possible, specifically 10% or less is preferable. More preferably, it is 5% or less, and most preferably 2% or less.

On the other hand, in addition to the function of suppressing the reflectance of the surface, in the case of imparting an antiglare function by surface scattering of the hard coat layer, the surface haze is preferably 1% to 15%, and preferably 2% to 10%. It is more preferable that
Also, when it is difficult to see the pattern, color unevenness, brightness unevenness, glare, etc. of the liquid crystal panel due to internal scattering of the hard coat layer, or to add the function of expanding the viewing angle by scattering, the internal haze value (from the total haze value) The value obtained by subtracting the surface haze value) is preferably 10% to 90%, more preferably 15% to 70%, and most preferably 20% to 50%.
The film of the present invention can freely set surface haze and internal haze according to the purpose.

  In addition, for the surface irregularity shape of the hard coat layer, in order to obtain a clear surface for the purpose of maintaining the sharpness of the image, among the characteristics indicating the surface roughness, for example, the centerline average roughness (Ra) is set. The thickness is preferably 0.10 μm or less. Ra is more preferably 0.09 μm or less, and still more preferably 0.08 μm or less. In the film of the present invention, the surface unevenness of the hard coat layer is dominant to the surface unevenness of the film, and the center line average roughness of the antireflection film is adjusted by adjusting the center line average roughness of the hard coat layer. It can be set as the said range.

  In order to maintain the sharpness of the image, it is preferable to adjust the clarity of the transmitted image in addition to adjusting the uneven shape of the surface. The clearness of the transmitted image of the clear antireflection film is preferably 60% or more. The transmitted image clarity is generally an index indicating the degree of blurring of an image reflected through a film, and the larger this value, the clearer and better the image viewed through the film. The transmitted image definition is preferably 70% or more, and more preferably 80% or more.

[Surface improver]
The coating solution used to make any layer on the base film has at least one of fluorine-based and silicone-based to improve surface defects (coating irregularities, drying irregularities, point defects, etc.) It is preferable to add a surface improver.

  The surface improver preferably changes the surface tension of the coating solution by 1 mN / m or more. Here, when the surface tension of the coating liquid changes by 1 mN / m or more, the surface tension of the coating liquid after the addition of the surface conditioner is added, including the concentration process during coating / drying. It means that it changes by 1 mN / m or more as compared with the surface tension of the coating liquid that has not been applied. The surface improver is preferably a surface improver that has an effect of lowering the surface tension of the coating solution by 1 mN / m or more, more preferably a surface improver that lowers by 2 mN / m or more, and 3 mN / m. It is more preferable that the surface conditioner be lowered.

  Preferable examples of the fluorine-based surface improver include compounds containing a fluoroaliphatic group. Examples of preferred compounds include those described in JP-A-2005-115359, JP-A-2005-221963, and JP-A-2005-234476.

[Light scattering layer]
When the protective film for a polarizing plate of the present invention is used on the surface of a liquid crystal display device, a reflection image of a surrounding object may be reflected on the surface, which may reduce the visibility of the display image. It is preferable that the surface of the hard coat layer is provided with unevenness to impart the ability to scatter light on the surface (antiglare property).
Further, the coating layer of the present invention may have a higher refractive index than the base film, and interference unevenness occurs due to the refractive index difference between the coating layer and the base film. In order to prevent the deterioration of visibility due to this interference unevenness, it is preferable to impart light scattering properties.

As a method for forming anti-glare properties, a method of laminating and forming a mat-shaped shaping film having fine irregularities on the surface as described in JP-A-6-16851, described in JP-A-2000-206317. A method of forming by curing shrinkage of an ionizing radiation curable resin due to a difference in ionizing radiation dose, as described in JP 2000-338310 A, and a mass ratio of a good solvent to a translucent resin is reduced by drying. A method of forming unevenness on the surface of the coating film by solidifying the light-transmitting fine particles and the light-transmitting resin while gelling, and providing surface unevenness by external pressure as described in JP-A-2000-275404 There are known methods, and these known methods can be used.
The antiglare layer that can be used in the present invention preferably contains a binder capable of imparting hard coat properties, translucent particles for imparting antiglare properties, and a solvent as essential components. It is preferable that irregularities on the surface be formed by the protrusions of the protrusions themselves or protrusions formed by an aggregate of a plurality of particles.
The antiglare layer having antiglare properties preferably has both antiglare properties and hard coat properties.
Details of the binder and translucent particles will be described below.

[binder]
The film of the present invention can be formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound. That is, a coating composition containing an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer as a binder is coated on a transparent support, and the polyfunctional monomer or polyfunctional oligomer is formed by a crosslinking reaction or a polymerization reaction. be able to.
The functional group of the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable.

As a specific example of a photopolymerizable polyfunctional monomer having a photopolymerizable functional group,
(Meth) acrylic acid diesters of alkylene glycol such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate;
(Meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts such as 2,2-bis {4- (acryloxy-diethoxy) phenyl} propane and 2,2-bis {4- (acryloxy-polypropoxy) phenyl} propane ;
Etc.

  Furthermore, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. More preferably, a polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule is preferable. Specifically, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, pentaerythritol tetra (meth) acrylate, penta Erythritol tri (meth) acrylate, (di) pentaerythritol triacrylate, (di) pentaerythritol pentaacrylate, (di) pentaerythritol tetra (meth) acrylate, (di) pentaerythritol hexa (meth) acrylate, tripentaerythritol triacrylate , Tripentaerythritol hexatriacrylate and the like. In the present specification, “(meth) acrylate”, “(meth) acrylic acid”, and “(meth) acryloyl” represent “acrylate or methacrylate”, “acrylic acid or methacrylic acid”, and “acryloyl or methacryloyl”, respectively. .

As the monomer binder, monomers having different refractive indexes can be used to control the refractive index of each layer. Examples of particularly high refractive index monomers include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like.
Further, for example, dendrimers described in JP-A-2005-76005 and JP-A-2005-36105, and norbornene ring-containing monomers as described in JP-A-2005-60425 can also be used.

Two or more polyfunctional monomers may be used in combination.
Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
It is preferable to use a photopolymerization initiator for the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator, a photoradical polymerization initiator and a photocationic polymerization initiator are preferable, and a photoradical polymerization initiator is particularly preferable.

<Photoinitiator>
Examples of photo radical polymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides (JP-A No. 2001-139663, etc.), 2, 3 -Dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like.
Examples of acetophenones include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxy-dimethylphenylketone, 1-hydroxy-dimethyl-p-isopropylphenylketone, 1-hydroxy Cyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 4-phenoxydichloroacetophenone, 4-t- Butyl-dichloroacetophenone is included.

Examples of benzoins include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether It is.
Examples of benzophenones include benzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone, 4,4′-dimethylaminobenzophenone (Michler ketone), 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone and the like are included.

  Examples of the borate salt are described in Japanese Patent Nos. 2764769 and 2002-116539, and Kunz, Martin “Rad Tech'98. Proceeding April 19-22, 1998, Chicago”. And the organic borate compounds described. For example, the compounds described in JP-A-2002-116539, paragraph numbers [0022] to [0027] can be mentioned. Examples of other organic boron compounds include JP-A-6-348011, JP-A-7-128785, JP-A-7-140589, JP-A-7-306527, and JP-A-7-292014. Specific examples include organoboron transition metal coordination complexes and the like, and specific examples include ion complexes with cationic dyes.

Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
Examples of the active esters include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], sulfonic acid esters, cyclic active ester compounds, and the like.
Specifically, Examples 1 to 21 described in JP-A 2000-80068 are particularly preferable.
Examples of the onium salts include aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts.

Specific examples of the active halogens include Wakabayashi et al., “Bull Chem. Soc Japan” 42, 2924 (1969), US Pat. No. 3,905,815, JP-A-5-27830, M.M. P. Examples include compounds described in Hutt “Journal of Heterocyclic Chemistry”, Vol. 1 (No. 3), (1970) and the like, and in particular, an oxazole compound substituted with a trihalomethyl group: an s-triazine compound. More preferred are s-triazine derivatives in which at least one mono-, di- or trihalogen-substituted methyl group is bonded to the s-triazine ring. Specific examples include S-triazine and oxathiazole compounds, such as 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl). -4,6-bis (trichloromethyl) -s-triazine, 2- (p-styrylphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3-Br-4-di (ethyl) Acetate) amino) phenyl) -4,6-bis (trichloromethyl) -s-triazine, 2-trihalomethyl-5- (p-methoxyphenyl) -1,3,4-oxadiazole. Specifically, p.14 to p30 in JP-A-58-15503, p6-p10 in JP-A-55-77742, and p287 in JP-B-60-27673. 1-No. 8, p443-p444 No. of JP-A-60-239736. 1-No. 17, No. 4,701,399. Compounds such as 1-19 are particularly preferred.
Examples of inorganic complexes include bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium.
Examples of coumarins include 3-ketocoumarin.

These initiators may be used alone or in combination.
“Latest UV Curing Technology”, Technical Information Association, 1991, p. 159, and “UV curing system” written by Kayo Kiyomi, 1989, General Technology Center, p. Various examples are also described in 65-148 and are useful in the present invention.

  Commercially available radical photopolymerization initiators include KAYACURE (DETX-S, BP-100, BDKM, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, ITX, QTX, BTC, manufactured by Nippon Kayaku Co., Ltd. MCA, etc.), Irgacure (651, 184, 500, 819, 907, 369, 1173, 1870, 2959, 4265, 4263, etc.) manufactured by Ciba Specialty Chemicals Co., Ltd., Esacure (KIP100F, KB1, manufactured by Sartomer) EB3, BP, X33, KT046, KT37, KIP150, TZT) and the like and combinations thereof are preferred examples.

  It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, More preferably, it is the range of 1-10 mass parts.

<Photosensitizer>
In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone.
Further, one or more auxiliary agents such as an azide compound, a thiourea compound, and a mercapto compound may be used in combination.
Examples of commercially available photosensitizers include KAYACURE (DMBI, EPA) manufactured by Nippon Kayaku Co., Ltd.

<Thermal initiator>
As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.
Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Diazo compounds such as 2,2′-azobis (isobutyronitrile), 2,2′-azobis (propionitrile), 1,1′-azobis (cyclohexanecarbonitrile) as azo compounds such as ammonium sulfate and potassium persulfate And diazoaminobenzene, p-nitrobenzenediazonium and the like.

[Translucent particles]
The translucent particles may be organic particles or inorganic particles. As the translucent particles, plastic beads are preferable, and those having particularly high transparency and a refractive index difference from the binder of 0.01 to 0.3 are preferable.
As organic particles, polymethyl methacrylate particles (refractive index 1.49), crosslinked poly (acryl-styrene) copolymer particles (refractive index 1.54), melamine resin particles (refractive index 1.57), polycarbonate particles ( Refractive index 1.57), polystyrene particles (refractive index 1.60), crosslinked polystyrene particles (refractive index 1.61), polyvinyl chloride particles (refractive index 1.60), benzoguanamine-melamine formaldehyde particles (refractive index 1. 68) etc. are used.
Examples of the inorganic particles include silica particles (refractive index: 1.44), alumina particles (refractive index: 1.63), zirconia particles, titania particles, and inorganic particles having hollows and pores.

  Of these, cross-linked polystyrene particles, cross-linked poly ((meth) acrylate) particles, and cross-linked poly (acryl-styrene) particles are preferably used, and a binder is selected according to the refractive index of each light-transmitting particle selected from these particles. By adjusting the refractive index, the internal haze, surface haze, and centerline average roughness of the present invention can be achieved.

  The refractive index of the binder (translucent resin) and translucent particles in the present invention is preferably 1.45 to 1.70, more preferably 1.48 to 1.65. In order to make the refractive index within the above range, the type and amount ratio of the binder and translucent particles may be appropriately selected. How to select can be easily known experimentally in advance.

  Here, the refractive index of the binder can be quantitatively evaluated by directly measuring it with an Abbe refractometer or by measuring a spectral reflection spectrum or a spectral ellipsometry. The refractive index of the translucent particles is measured by measuring the turbidity by dispersing an equal amount of the translucent particles in the solvent in which the refractive index is changed by changing the mixing ratio of two types of solvents having different refractive indexes. It is measured by measuring the refractive index of the solvent when the turbidity is minimized with an Abbe refractometer.

  In the case of the above translucent particles, the translucent particles easily settle in the binder, and therefore an inorganic filler such as silica may be added to prevent sedimentation. As the amount of the inorganic filler added increases, it is more effective in preventing the translucent particles from settling, but adversely affects the transparency of the coating film. Therefore, preferably, an inorganic filler having a particle size of 0.5 μm or less is contained in an amount of less than 0.1% by mass so as not to impair the transparency of the coating film with respect to the binder.

The average particle diameter of the translucent particles is preferably 0.5 to 10 μm, more preferably 2.0 to 8.0 μm. An average particle size of 0.5 μm or more and 10 μm or less is preferable because it does not cause display character blur and does not cause problems such as curling and cost increase.

  Moreover, you may use together and use 2 or more types of translucent particle | grains from which a particle diameter differs. It is possible to impart an antiglare property with a light-transmitting particle having a larger particle diameter, and to reduce surface glare with a light-transmitting particle having a smaller particle diameter.

  The said translucent particle | grain is mix | blended so that 3-30 mass% may be contained in the addition layer total solid. More preferably, it is 5-20 mass%. If it is less than 3% by mass, the effect of addition is insufficient, and if it exceeds 30% by mass, problems such as image blur, surface turbidity and glare occur.

Moreover, the density of the translucent particles is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ² .

<Translucent particle preparation, classification method>
Examples of the method for producing translucent particles according to the present invention include suspension polymerization, emulsion polymerization, soap-free emulsion polymerization, dispersion polymerization, seed polymerization, and the like. Good. These production methods are described in, for example, “Experimental Methods for Polymer Synthesis” (Takayuki Otsu and Masaaki Kinoshita, Chemical Dojinsha), pages 130 and 146 to 147, “Synthetic Polymers”, Vol. 246-290, 3rd volume, p. 1 to 108, etc., and Japanese Patent Nos. 2543503, 3508304, 2746275, 3521560, 3580320, and Japanese Patent Laid-Open No. 10-1561. Reference can be made to methods described in JP-A No. 7-2908, JP-A No. 5-297506, JP-A No. 2002-145919, and the like.

The particle size distribution of the translucent particles is preferably monodisperse particles in terms of haze value and diffusibility control, and uniformity of the coated surface. For example, when particles having a particle size of 20% or more than the average particle size are defined as coarse particles, the proportion of coarse particles is preferably 1% or less, more preferably 0.1% or less of the total number of particles. Yes, more preferably 0.01% or less. Particles having such a particle size distribution are also effective means of classification after preparation or synthesis reaction, and particles having a desired distribution can be obtained by increasing the number of classifications or increasing the degree of classification. .
It is preferable to use a method such as an air classification method, a centrifugal classification method, a sedimentation classification method, a filtration classification method, or an electrostatic classification method for classification.

Two or more kinds of mat particles having different particle diameters may be used in combination. It is possible to impart anti-glare properties with mat particles having a larger particle size and to impart other optical characteristics with mat particles having a smaller particle size. For example, when an anti-glare antireflection film is attached to a high-definition display of 133 ppi or higher, a problem in display image quality called “glare” may occur. “Glitter” is derived from the fact that pixels are enlarged or reduced due to unevenness present on the surface of the antiglare and antireflection antireflection film, resulting in loss of luminance uniformity, but particles smaller than mat particles that impart antiglare properties. It can be greatly improved by using mat particles having a diameter different from that of the binder.
The particle size distribution of the mat particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

[Phase separation]
As an example of a method for creating a light scattering layer, a method for creating a light scattering layer by spinodal decomposition of a plurality of polymers can be given as an example of a method other than the use of translucent particles to exhibit antiglare properties. In particular, it is possible to impart good light scattering properties by giving a difference in the refractive indexes of the phase separated phases.
The light scattering layer formed by spinodal decomposition is composed of a plurality of polymers having different refractive indexes, and is usually a phase having at least a co-continuous phase structure in an operating atmosphere (especially at room temperature of about 10 to 30 ° C.). A separation structure is formed.
The co-continuous phase structure is formed by spinodal decomposition from a liquid phase containing a plurality of polymers (liquid phase at room temperature, for example, a mixed liquid or a solution).
The bicontinuous phase structure is usually formed by spinodal decomposition through evaporation of a solvent using a composition (for example, a mixed solution or a solution) containing a plurality of polymers and forming a liquid phase at room temperature.
Since such a light scattering layer is formed from a liquid phase, it has a uniform and fine co-continuous phase structure. When such a transmissive light scattering sheet is used, incident light is substantially isotropically scattered, and directivity can be imparted to the transmitted scattered light. Therefore, both high light scattering and directivity can be achieved.

  In order to enhance light scattering properties, a plurality of polymers can be used in combination so that the difference in refractive index is, for example, about 0.01 to 0.2, and preferably about 0.1 to 0.15. If the difference in refractive index is less than 0.01, the intensity of the transmitted scattered light decreases. If the difference in refractive index is greater than 0.2, high directivity cannot be imparted to the transmitted scattered light.

  The plurality of polymers include, for example, styrene resins, (meth) acrylic resins, vinyl ester resins, vinyl ether resins, halogen-containing resins, olefin resins (including alicyclic olefin resins), polycarbonate resins, and polyesters. Resin, polyamide resin, thermoplastic polyurethane resin, polysulfone resin (polyethersulfone, polysulfone, etc.), polyphenylene ether resin (2,6-xylenol polymer, etc.), cellulose derivatives (cellulose esters, cellulose carbamates) , Cellulose ethers, etc.), silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubbers or elastomers (diene rubbers such as polybutadiene, polyisoprene, styrene-butadiene copolymers, Acrylonitrile - butadiene copolymer, acrylic rubber, urethane rubber, silicone rubber, etc.) can be chosen a suitable combination and the like.

  Preferred polymers include, for example, styrene resins, (meth) acrylic resins, vinyl ester resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins, Cellulose derivatives, silicone resins, rubbers or elastomers are included. As the plurality of polymers, a resin that is non-crystalline and is soluble in an organic solvent (in particular, a common solvent capable of dissolving the plurality of polymers) is usually used. In particular, resins with high moldability or film formability, transparency and weather resistance, such as styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) Etc. are preferable.

These plural polymers can be used in appropriate combinations. For example, in a combination of polymers, at least one polymer may be selected from cellulose derivatives, particularly cellulose esters (eg, cellulose C2-4 alkyl carboxyls such as cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate). Acid esters) and may be combined with other polymers.

  The glass transition temperature of the polymer can be selected from the range of, for example, −100 ° C. to 250 ° C., preferably −50 to 230 ° C., more preferably about 0 to 200 ° C. (for example, about 50 to 180 ° C.). From the viewpoint of sheet strength and rigidity, the glass transition temperature of at least one of the constituent polymers is 50 ° C. or higher (for example, about 70 to 200 ° C.), preferably 100 ° C. or higher (for example, 100 to 170 ° C.). It is advantageous that The weight average molecular weight of the polymer can be selected from the range of, for example, 1,000,000 or less (about 10,000 to 1,000,000), preferably about 10,000 to 700,000.

  Since the present invention employs a wet method in which a solvent is evaporated from a liquid phase containing a plurality of polymers and spinodal decomposition is performed, in principle, a substantially isotropic common is used regardless of the compatibility of the plurality of polymers. A light scattering layer having a continuous phase structure can be formed. For this reason, it may be configured by combining a plurality of mutually compatible polymers. However, in order to easily control the phase separation structure by spinodal decomposition and to form a co-continuous phase structure efficiently, incompatible (phase separation) In many cases, a plurality of polymers are combined.

The plurality of polymers can be constituted by a combination of the first polymer and the second polymer, and each of the first polymer and the second polymer may be constituted by a single resin or a plurality of resins. Also good. The combination of the first polymer and the second polymer is not particularly limited. For example, when the first polymer is a cellulose derivative (for example, cellulose esters such as cellulose acetate propionate), the second polymer is a styrene resin (polystyrene, styrene-acrylonitrile copolymer, etc.), (meta ) Acrylic resins (such as polymethyl methacrylate), alicyclic olefin resins (such as polymers containing norbornene as monomers), polycarbonate resins, polyester resins (such as poly C2-4 alkylene arylate copolyester) Or the like.

  The ratio of the first polymer to the second polymer is, for example, the former / the latter = about 10/90 to 90/10 (weight ratio), preferably about 20/80 to 80/20 (weight ratio), and more preferably Is about 30/70 to 70/30 (weight ratio), particularly about 40/60 to 60/40 (weight ratio). When the ratio of one polymer is too large, the volume ratio between the separated phases is biased, so that the intensity of scattered light decreases. In addition, when forming a sheet | seat with a 3 or more polymer, content of each polymer is 1 to 90 weight% normally (for example, 1 to 70 weight%, Preferably it is 5 to 70 weight%, More preferably, it is 10 (About 70% by weight).

  The light scattering layer constituting the light scattering sheet of the present invention has at least a co-continuous phase structure. The co-continuous phase structure is sometimes referred to as a co-continuous structure or a three-dimensional continuous or connected structure, and means a structure in which at least two constituent polymer phases are continuous (for example, a network structure). . The light scattering layer only needs to have at least a co-continuous phase structure, and may have a structure in which a co-continuous phase structure and a droplet phase structure (independent or isolated phase structure) are mixed. In spinodal decomposition, a co-continuous phase structure is formed as the phase separation progresses, and when the phase separation is further advanced, the continuous phase becomes discontinuous due to its surface tension, and the droplet phase structure (spherical, true spherical) Sea island structure of independent phase). Therefore, depending on the degree of phase separation, an intermediate structure between the co-continuous phase structure and the droplet phase structure, that is, a phase structure in the process of shifting from the co-continuous phase to the droplet phase can be formed. In the present invention, the intermediate structure is also referred to as a co-continuous phase structure. When the phase separation structure is a mixed structure of a co-continuous phase structure and a droplet structure, the ratio of the droplet phase (independent polymer phase) is, for example, 30% or less (volume ratio), preferably 10% or less ( Volume ratio). The shape of the co-continuous phase structure is not particularly limited, and may be a network shape, particularly a random network shape.

  The bicontinuous phase structure is generally isotropic with reduced anisotropy in the layer or sheet plane. Note that isotropic means that the average interphase distance of the co-continuous phase structure is substantially equal in any direction in the sheet plane.

  The bicontinuous phase structure usually has regularity in the interphase distance (distance between the same phases). For this reason, the light scattered on the sheet is directed to a specific direction by Bragg reflection. Therefore, even when mounted on a reflective liquid crystal display device, the transmitted scattered light can be directed in a certain direction, the display screen can be made highly bright, and a conventional particle-dispersed transmissive light scattering sheet Thus, a problem that cannot be solved, that is, reflection of a light source (for example, a fluorescent lamp) on the panel can be avoided.

  In the light scattering sheet, the average interphase distance between the co-continuous phases is, for example, about 0.5 to 20 μm (for example, 1 to 20 μm), preferably about 1 to 15 μm (for example, 1 to 10 μm). If the average interphase distance is too small, it is difficult to obtain high scattered light intensity, and if the average interphase distance is too large, the directivity of transmitted scattered light decreases.

  The average interphase distance of the co-continuous layer can be calculated from a photomicrograph (such as a transmission microscope, a phase contrast microscope, or a confocal laser microscope) of the light scattering layer or light scattering sheet. In addition, the scattering angle θ at which the scattered light intensity is maximized is measured by a method similar to the scattered light directivity evaluation method described later, and the average interphase distance d of the co-continuous phase is calculated from the following Bragg reflection condition equation. May be.

2d · sin (θ / 2) = λ
(Where d is the average interphase distance of co-continuous phases, θ is the scattering angle, and λ is the wavelength of light)
[Emboss]
An example of a method for creating a light scattering layer is a method for creating a light scattering layer by an embossing method as an example of a method other than the use of translucent particles to exhibit antiglare properties.
The light scattering layer prepared by the embossing method is an ionizing radiation curable resin composition or a thermosetting resin composition formed on a transparent substrate with a mat-shaped molding film having fine irregularities on the surface. A light diffusion layer consisting essentially of is formed.
When the resin is an ionizing radiation curable resin composition, the light scattering layer is produced by coating the ionizing radiation curable resin composition on a transparent substrate and then applying the ionizing radiation curable resin. By laminating a mat-shaped shaped film having fine irregularities on the surface of the uncured coating film of the composition, and then irradiating ionizing radiation on the coated film on which the shaped film is laminated, It is preferable to manufacture the coating film of the ionizing radiation curable resin composition by a manufacturing method in which the shaped film is peeled from the cured coating film of the ionizing radiation curable resin.
When the resin is a thermosetting resin composition, the thermosetting resin composition is applied on a transparent substrate, and then the uncured coating film of the applied thermosetting resin composition is applied. A mat-like shaped film having fine irregularities on the surface is laminated, and then the coating film laminated with the shaped film is heated and cured, and then the cured thermosetting resin composition is applied. It is preferable to manufacture by the manufacturing method which peels a shaping film from a film | membrane.

When laminating the shaping film on the coating film of the uncured ionizing radiation curable resin composition, if the coated resin is of a solvent dilution type, the solvent is dried and then laminating, If the applied resin is solventless, lamination is performed as it is.
The film forming component of the ionizing radiation curable resin composition used for the light diffusing layer of the embossing method is preferably one having an acrylate functional group, such as a polyester resin, polyether resin, acrylic resin having a relatively low molecular weight. , Epoxy or urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, oligomers or prepolymers of polyfunctional compounds such as polyhydric alcohols and prepolymers, and ethyl (meth) as a reactive diluent Monofunctional monomers such as acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone and polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tri Lopylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) ) Those containing a relatively large amount of acrylate or the like can be used.

  The film forming component is particularly preferably a mixture of polyester acrylate and polyurethane acrylate. The reason is that polyester acrylate is very hard and suitable for obtaining a hard coat, but polyester acrylate alone has low impact and is brittle. In order to give the properties, polyurethane acrylate is used in combination. The blending ratio of polyurethane acrylate with respect to 100 parts by weight of polyester acrylate is 30 parts by weight or less. If this value is exceeded, the coating film is too soft and the hardness is lost.

  Further, in order to make the ionizing radiation curable resin composition into an ultraviolet curable resin composition, acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime ester, tetra Methyl thiuram monosulfide, thioxanthones, and n-butylamine, triethylamine, tri-n-butylphosphine, and the like can be used as a photosensitizer. In particular, in the present invention, it is preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexa (meth) acrylate as a monomer.

  The coating material for forming a hard coat (scratch resistance) coating film having light diffusibility contains 10 parts by weight or more and 100 parts by weight or less of solvent-drying resin with respect to 100 parts by weight of ionizing radiation curable resin. Also good. As the solvent-drying resin, a thermoplastic resin is mainly used. The types of solvent-drying thermoplastic resins added to ionizing radiation curable resins are usually those used, especially when a mixture of polyester acrylate and polyurethane acrylate is used for ionizing radiation curable resins. In the solvent drying type resin, polymethyl methacrylate acrylate or polybutyl methacrylate acrylate can keep the hardness of the coating film high. In addition, in this case, since the refractive index is close to that of the main ionizing radiation curable resin, the transparency of the coating film is not impaired, and this is advantageous in terms of transparency, particularly low haze value, high transmittance, and compatibility.

  In addition, when using a cellulose-based resin such as triacetylcellulose as the transparent substrate, the solvent-drying resin to be included in the ionizing radiation curable resin includes nitrocellulose, acetylcellulose, cellulose acetate propionate, ethylhydroxyethylcellulose, etc. The cellulosic resin is advantageous in terms of adhesion and transparency of the coating film.

  The film thickness of the antiglare layer is preferably 1 to 25 μm, and more preferably 2 to 15 μm. If it is too thin, the hard property is insufficient, and if it is too thick, curling and brittleness may be deteriorated and workability may be lowered.

When suppressing iridescent unevenness in the light scattering layer, the total haze is preferably 10% to 80%, more preferably 20% to 70%. Moreover, it is preferable that surface haze is 0.3%-70%, and it is more preferable that it is 0.3%-20%.
Furthermore, when it is difficult to see the pattern, color unevenness, brightness unevenness, glare, etc. of the liquid crystal panel due to internal scattering of the hard coat layer, or to add the function of expanding the viewing angle by scattering, the internal haze value (from the total haze value) The value obtained by subtracting the surface haze value) is preferably 10% to 80%, more preferably 15% to 70%, and most preferably 20% to 60%.
The film of the present invention can freely set surface haze and internal haze according to the purpose.

  On the other hand, the center line average roughness (Ra) of the antiglare layer is preferably in the range of 0.01 to 0.40 μm, and more preferably in the range of 0.05 to 0.20 μm. If it exceeds 0.40 μm, problems such as glare and whitening of the surface when external light is reflected occur. Further, it is preferable that the value of the transmitted image definition is 5 to 60%.

  The strength of the antiglare layer is preferably 2H or more, more preferably 3H or more, and most preferably 4H or more in the pencil hardness test.

[Solvent for layer having hard coat property]
Since the hard coat layer of the present invention is often wet-coated on the coating layer, the solvent used in the coating composition is an important factor. The requirements include sufficiently dissolving various solutes such as the translucent resin, not dissolving the translucent fine particles, and being less likely to cause coating unevenness and drying unevenness during the coating to drying process. In addition, the solubility of the lower layer is not too high (necessary for failure prevention such as deterioration of flatness and whitening), and conversely, the support is dissolved and swollen to the minimum extent (necessary for adhesion). This is a preferable characteristic. One type of solvent may be used, but it is particularly preferable to adjust the solubility of the support, the swelling property, the solubility of the material, the drying property, the aggregation property of the particles, and the like by using two or more types of solvents. By adding a small amount of highly swellable solvent to the low-swelling main solvent of the transparent support, it is possible to improve the adhesion with the transparent support without deteriorating other performance and surface condition. it can.
As specific examples, various ketones (such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone) and various cellosolves (such as ethyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether) are preferably used as the solvent. In addition, various alcohols (propylene glycol, ethylene glycol, ethanol, methanol, isopropyl alcohol, 1-butanol, 2-butanol, etc.), toluene and the like are preferably used.

[High refractive index layer (medium refractive index layer)]
On the film of the present invention, when a high refractive index layer and a medium refractive index layer are provided on the hard coat layer and optical interference is used together with the low refractive index layer described later, the antireflection property can be further improved.
In the following description, the high refractive index layer and the medium refractive index layer may be collectively referred to as a high refractive index layer. In the present invention, “high”, “medium”, and “low” in the high refractive index layer, medium refractive index layer, and low refractive index layer represent the relative refractive index relationship between the layers. In terms of the relationship with the transparent substrate, the refractive index preferably satisfies the relationship of transparent substrate film> low refractive index layer, high refractive index layer> transparent substrate film.
In the present specification, the high refractive index layer, the middle refractive index layer, and the low refractive index layer may be collectively referred to as an antireflection layer.

  In order to construct an antireflection film by constructing a low refractive index layer on a high refractive index layer, the refractive index of the high refractive index layer is preferably 1.55 to 2.40, and 1.60. To 2.20 is more preferable, 1.65 to 2.10 is more preferable, and 1.80 to 2.00 is particularly preferable.

  When an antireflection film is prepared by coating a hard coat layer, a medium refractive index layer, a high refractive index layer, and a low refractive index layer in order from the transparent base film, the refractive index of the high refractive index layer is 1.65. It is preferably ˜2.40, more preferably 1.70 to 2.20. The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.55-1.80.

Specific examples of the inorganic particles used in the high refractive index layer and the medium refractive index layer include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , ITO and SiO _2. Etc. Among these, TiO ₂ and ZrO ₂ are particularly preferable in terms of increasing the refractive index.
The inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment on the surface, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.

The content of the inorganic particles in the high refractive index layer is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and still more preferably 15 to 75% by mass with respect to the mass of the high refractive index layer. Two or more kinds of inorganic particles may be used in combination in the high refractive index layer.
When the low refractive index layer is provided on the high refractive index layer, the refractive index of the high refractive index layer is preferably higher than the refractive index of the transparent substrate film.
The high refractive index layer contains an ionizing radiation curable compound containing an aromatic ring, an ionizing radiation curable compound containing a halogenated element other than fluorine (for example, Br, I, Cl, etc.), and atoms such as S, N, P, etc. A binder obtained by a crosslinking or polymerization reaction such as an ionizing radiation curable compound can also be preferably used.

  The film thickness of the high refractive index layer can be appropriately designed depending on the application. When using a high refractive index layer as an optical interference layer described later, 30 to 200 nm is preferable, 50 to 170 nm is more preferable, and 60 to 150 nm is still more preferable.

  The haze of the high refractive index layer is preferably as low as possible when it does not contain particles that impart an antiglare function. For example, it is preferably 5% or less, more preferably 3% or less, and still more preferably 1% or less. The high refractive index layer is preferably constructed on the transparent substrate film via another layer.

  When the protective film for polarizing plates of the present invention is used on the surface of a liquid crystal display device, it is also preferable to form a low refractive index layer on the surface of the hard coat layer as a method for preventing reflection. The low refractive index layer that can be preferably used in the present invention will be described below.

[Low refractive index layer]
The low refractive index layer used in the present invention has a thermosetting property and / or a photocuring property mainly comprising a fluorine-containing compound containing a fluorine atom in a range of 35 to 80% by mass and containing a crosslinkable or polymerizable functional group. It is preferably formed by applying a composition having the same.
The refractive index of the low refractive index layer in the antiglare antireflection film of the present invention is preferably 1.45 or less, more preferably 1.30 or more and 1.40 or less, and 1.33 or more and 1.37 or less. Further preferred.
Further, the low refractive index layer preferably satisfies the following mathematical formula (3) from the viewpoint of reducing the reflectance.

Formula (3)
(M / 4) × 0.7 <n1 × d1 <(m / 4) × 1.3 Expression (3)

In Equation (3), m is a positive odd number, n1 is the refractive index of the low refractive index layer, and d1 is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm.
In addition, satisfy | filling said numerical formula (3) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (3) exists in the said wavelength range.

The low refractive index layer is a cured film formed by, for example, applying, drying and curing a curable composition containing a fluorine-containing compound as a main component. The curable composition used in forming the low refractive index layer contains at least two of (A) a fluorine-containing compound, (B) inorganic fine particles, and (C) an organosilane compound. Is preferable, and it is particularly preferable that all three types are contained. As the fluorine-containing compound, it is preferable to use a fluorine-containing polymer having a low refractive index or a fluorine-containing sol-gel material. As a fluorine-containing polymer or fluorine-containing sol-gel, a material having a dynamic friction coefficient of 0.03 to 0.30 on the surface of a low refractive index layer formed by crosslinking with heat or ionizing radiation and having a contact angle with water of 85 to 120 ° Is preferred.
The material for forming the low refractive index layer will be described below.

<Fluoropolymer for low refractive index layer>
The fluoropolymer has a cured film having a coefficient of dynamic friction of 0.03 to 0.20, a contact angle with water of 90 to 120 °, and a sliding angle of pure water of 70 ° or less, and heat or ionization. A polymer that is cross-linked by radiation is preferable from the viewpoint of improving productivity in the case of applying and curing a roll film while conveying the web.
Also, when the antiglare film or antiglare antireflection film of the present invention is mounted on a liquid crystal display device, the lower the peel strength from a commercially available adhesive tape, the easier it is to peel off after sticking a sticker or memo. The force is preferably 500 gf (4.9 N) or less, more preferably 300 gf (2.9 N) or less, and most preferably 100 gf (0.98 N) or less. Further, the higher the surface hardness measured with a microhardness meter, the harder it is to scratch. Therefore, the surface hardness is preferably 0.3 GPa or more, and more preferably 0.5 GPa or more.

  The fluorine-containing polymer used in the low refractive index layer is preferably a fluorine-containing polymer containing a fluorine atom in a range of 35 to 80% by mass and containing a crosslinkable or polymerizable functional group. In addition to hydrolyzate and dehydration condensate of alkyl group-containing silane compound [for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane], a fluorine-containing monomer unit and a crosslinking reactive unit are constituted. Examples thereof include a fluorine-containing copolymer as a unit. In the case of a fluorinated copolymer, the main chain preferably consists of only carbon atoms. That is, it is preferable that the main chain skeleton does not have an oxygen atom or a nitrogen atom.

  Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3- Dioxoles, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, etc. However, perfluoroolefins are preferable, and hexafluoropropylene is particularly preferable from the viewpoint of refractive index, solubility, transparency, availability, and the like.

  Examples of the crosslinking reactive unit include a structural unit obtained by polymerization of a monomer having a self-crosslinking functional group in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether; carboxyl group, hydroxy group, amino group, sulfo group A structural unit obtained by polymerization of a monomer having, for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc. And a structural unit in which a crosslinkable reactive group such as a (meth) acryloyl group is introduced by a polymer reaction (for example, it can be introduced by a technique such as allowing acrylic acid chloride to act on a hydroxy group).

  In addition to the fluorine-containing monomer unit and the cross-linking reactive unit, from the viewpoint of solubility in a solvent, film transparency, and the like, a monomer not containing a fluorine atom is appropriately copolymerized to introduce another polymerization unit. You can also. There are no particular limitations on the monomer units that can be used in combination, such as olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate), Methacrylic esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl vinyl ether, ethyl vinyl ether) , Cyclohexyl vinyl ether, etc.], vinyl esters [vinyl acetate, vinyl propionate, vinyl cinnamate, etc.], acrylamides [N-tertbutylacrylamide, N-cyclohexylacrylic acid, etc.] Amides], methacrylamides, and acrylonitrile derivatives.

  As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be appropriately used in combination with the fluoropolymer.

The fluorine-containing polymer particularly useful in the present invention is a random copolymer of perfluoroolefin and vinyl ethers or vinyl esters. In particular, it preferably has a group capable of undergoing crosslinking reaction alone (radical reactive group such as (meth) acryloyl group, ring-opening polymerizable group such as epoxy group and oxetanyl group).
These crosslinkable group-containing polymerized units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymerized units of the polymer.

  A preferred form of the fluorine-containing polymer for the low refractive index layer used in the present invention is a copolymer represented by the general formula (2).

In the general formula (2), L represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, which is linear. Alternatively, it may have a branched structure, may have a ring structure, and may have a heteroatom selected from O, N and S.
Preferred examples include * — (CH ₂ ) ₂ —O — **, * — (CH ₂ ) ₂ —NH — **, * — (C
_{H 2) 4 -O - **,} * - (CH 2) 6 -O - **, * - (CH 2) 2 -O- (CH 2) 2 -O - **, * - CONH- (CH ₂ ) _3— O — **, * —CH ₂ CH (OH) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** (* represents the polymer main chain side) Represents a linking site, and ** represents a linking site on the (meth) acryloyl group side). m represents 0 or 1;
In general formula (2), X represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

  In the general formula 1, A represents a repeating unit derived from an arbitrary vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with hexafluoropropylene. Tg (contributes to film hardness), solubility in solvents, transparency, slipperiness, dust / antifouling properties, etc., can be selected as appropriate, depending on the purpose, depending on the single or multiple vinyl monomers It may be configured.

  Preferred examples include methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, vinyl ethers such as allyl vinyl ether, vinyl acetate, vinyl propionate, butyric acid. (Meth) such as vinyl esters such as vinyl, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane Acrylates, styrene, styrene derivatives such as p-hydroxymethylstyrene, crotonic acid, maleic acid, itaconic acid Can be mentioned unsaturated carboxylic acids and derivatives thereof, more preferably ether derivatives, vinyl ester derivatives, particularly preferably a vinyl ether derivative.

x, y, and z represent the mol% of each constituent component, and preferably 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65, and more preferably 35 ≦ x ≦ 55 and 30 ≦ y ≦. 60, 0 ≦ z ≦ 20, particularly preferably 40 ≦ x ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10. However, x + y + z = 100.
A particularly preferred form of the copolymer used in the present invention is general formula (3).

In general formula (3), X represents the same meaning as in general formula (2), and the preferred range is also the same.
n represents an integer of 2 ≦ n ≦ 10, preferably 2 ≦ n ≦ 6, and particularly preferably 2 ≦ n ≦ 4.
B represents a unit of a repeating unit derived from an arbitrary vinyl monomer, and may be composed of a single composition or a plurality of compositions. As an example, what was demonstrated as an example of A in the said General formula (2) is applicable.
x, y, z1 and z2 represent mol% of each repeating unit, and x and y preferably satisfy 30 ≦ x ≦ 60 and 5 ≦ y ≦ 70, respectively, more preferably 35 ≦ x ≦ 55. 30 ≦ y ≦ 60, particularly preferably 40 ≦ x ≦ 55 and 40 ≦ y ≦ 55. z1 and z2 preferably satisfy 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65, more preferably 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10, and 0 ≦ z1 ≦ 10, 0 It is particularly preferable that ≦ z2 ≦ 5. However, x + y + z1 + z2 = 100.
The copolymer represented by the general formula (2) or (3) is, for example, a copolymer containing a hexafluoropropylene component and a hydroxyalkyl vinyl ether component having a (meth) acryloyl group by any one of the methods described above. It can be synthesized by introduction. As the reprecipitation solvent used at this time, isopropanol, hexane, methanol and the like are preferable.
Preferable specific examples of the copolymer represented by the general formula 1 or 2 include those described in [0035] to [0047] of JP-A-2004-45462, and the method described in the publication Can be synthesized.

<Inorganic fine particles for low refractive index layer>
The amount of the inorganic fine particles is preferably ^{1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . If the amount is too small, the effect of improving the scratch resistance is reduced. It is preferable to be inside.
Since the inorganic fine particles are contained in the low refractive index layer, it is desirable to have a low refractive index. Examples thereof include fine particles of magnesium fluoride and silicon oxide (silica). In particular, silica fine particles are preferable in terms of refractive index, dispersion stability, and cost.
The average particle size of the inorganic fine particles is, for example, preferably 10% to 100%, preferably 30% to 100%, more preferably 35% to 80%, and still more preferably 40% to 60% of the thickness of the low refractive index layer. It is as follows. That is, when the thickness of the low refractive index layer is 100 nm, the particle diameter of the silica fine particles is preferably 30 nm to 100 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
If the particle size of the inorganic fine particles is too small, the effect of improving the scratch resistance is reduced. Therefore, it is preferable to be within the above range. The inorganic fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably spherical, but there is no problem even if it is indefinite.
Here, the average particle diameter of the inorganic fine particles is measured by a Coulter counter.

  In order to further reduce the increase in the refractive index of the low refractive index layer, the inorganic fine particles preferably have a hollow structure, and the refractive index of the inorganic fine particles is preferably 1.17 to 1.40, more preferably. 1.17 to 1.35, more preferably 1.17 to 1.30. Here, the refractive index represents the refractive index of the entire particle, and does not represent the refractive index of only the inorganic material of the outer shell in the case of inorganic fine particles having a hollow structure. At this time, when the radius of the cavity in the particle is a and the radius of the particle shell is b, the porosity x is expressed by the following formula (4).

^{x = (4πa 3/3)} / (4πb 3/3) × 100 ···· ( Equation 4)

The porosity x is preferably 10 to 60%, more preferably 20 to 60%, and still more preferably 30 to 60%.
If the refractive index of hollow inorganic fine particles is made lower and the porosity is increased, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. Therefore, from the viewpoint of scratch resistance, the refractive index is 1 Particles with a low refractive index of less than .17 do not hold.
The refractive index of the inorganic fine particles can be measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

In addition, at least one kind of inorganic fine particles (hereinafter referred to as “small size inorganic fine particles”) having an average particle size of less than 25% of the thickness of the low refractive index layer is referred to as “inorganic fine particles (hereinafter referred to as“ small size inorganic fine particles ”). It may be used in combination with “large-size inorganic fine particles”.
Since the small-sized inorganic fine particles can be present in the gaps between the large-sized inorganic fine particles, they can contribute as a retaining agent for the large-sized inorganic fine particles.
When the low refractive index layer is 100 nm, the average particle size of the small-sized inorganic fine particles is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm. Use of such inorganic fine particles is preferable in terms of raw material costs and a retaining agent effect.
As described above, the inorganic fine particles have an average particle size of 30 to 100% of the thickness of the low refractive index layer as described above, have a hollow structure, and have a refractive index of 1.17 to 1. What is 40 is used especially preferably.

Inorganic fine particles are treated with physical surface treatment such as plasma discharge treatment or corona discharge treatment in order to stabilize dispersion in the dispersion or coating solution, or to improve the affinity and binding properties with the binder component. Further, chemical surface treatment with a surfactant, a coupling agent or the like may be performed. Of these, the use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Of these, silane coupling treatment is particularly effective.
The coupling agent is used as a surface treatment agent for the inorganic fine particles of the low refractive index layer in advance for surface treatment prior to the preparation of the layer coating solution, and is further added as an additive during preparation of the layer coating solution. It is preferable to make it contain in a layer.
The inorganic fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.

Next, (C) the organosilane compound will be described.
<Organosilane compound for low refractive index layer>
The curable composition includes an organosilane compound, a hydrolyzate of the organosilane, and a partial condensate of the hydrolyzate of the organosilane (hereinafter, the obtained reaction solution is also referred to as “sol component”). It is preferable to contain at least one selected from the group consisting of scratch resistance, particularly in terms of achieving both antireflection ability and scratch resistance.
These components function as a binder for the low refractive index layer by applying the curable composition and then condensing in a drying and heating process to form a cured product. In the present invention, since the fluorine-containing compound preferably has the fluorine-containing polymer, a binder having a three-dimensional structure is formed by irradiation with actinic rays.
The organosilane compound is preferably represented by the following general formula (4).

In the general formula (4), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl and the like.
The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.
X represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I or the like). ), And R ² COO (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, such as CH ₃ COO, C ₂ H ₅ COO, etc.), preferably An alkoxy group, particularly preferably a methoxy group or an ethoxy group.
m represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.

When R ¹⁰ or X there are a plurality, a plurality of R ¹⁰ or X groups may be different, even the same, respectively.
The substituent contained in R ¹⁰ is not particularly limited, but a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy etc.), aryloxy (phenoxy etc.) ), Alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxy) Carbonyl, etc.), aryloxy Carbonyl groups (phenoxycarbonyl, etc.), carbamoyl groups (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl, etc.), acylamino groups (acetylamino, benzoylamino, acrylicamino, methacrylamino) Etc.), and these substituents may be further substituted.

When there are a plurality of R ^{10 s} , at least one is preferably a substituted alkyl group or a substituted aryl group.
Among the organosilane compounds represented by the general formula (4), an organosilane compound having a vinyl polymerizable substituent represented by the following general formula (5) is preferable.

In the general formula (5), R ¹ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom and a chlorine atom are preferred, a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom and a chlorine atom are more preferred, and a hydrogen atom and a methyl group Is particularly preferred.
Y represents a single bond or * -COO-**, * -CONH-** or * -O-**, preferably a single bond, * -COO-** or * -CONH-**, * -COO-** is more preferable, and * -COO-** is particularly preferable. * Indicates the position bonded to ═C (R ¹ ) —, **
Represents the position of binding to L.

  In the general formula (5), L represents a divalent linking chain. Specifically, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group having a linking group (for example, ether, ester, amide, etc.) inside, and a linking group inside. A substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an alkylene group having a linking group therein is preferred, an unsubstituted alkylene group, an unsubstituted arylene group Further, an alkylene group having an ether or ester linking group inside is more preferable, an unsubstituted alkylene group, and an alkylene group having an ether or ester linking group inside is particularly preferable. Examples of the substituent include a halogen, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group, and these substituents may be further substituted.

In the general formula (5), n represents 0 or 1. When there are a plurality of Xs, the plurality of Xs may be the same or different. n is preferably 0.
In the general formula (5), R ¹⁰ has the same meaning as in the general formula (4), and is preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and an unsubstituted alkyl group or an unsubstituted aryl group. Is more preferable.
Moreover, in the said General formula (5), X is synonymous with General formula (4), A halogen atom, a hydroxyl group, and an unsubstituted alkoxy group are preferable, A chlorine atom, a hydroxyl group, and an unsubstituted C1-C6 alkoxy Group is more preferable, a hydroxyl group and an alkoxy group having 1 to 3 carbon atoms are more preferable, and a methoxy group is particularly preferable.

  Two or more compounds of the general formula (4) and general formula (5) may be used in combination. Although the specific example of a compound represented by General formula (4) and General formula (5) below is shown, it is not limited.

  Of the above (M-1) to (M-10), (M-1), (M-2), and (M-5) are particularly preferable.

The hydrolyzate and / or partial condensate of the organosilane compound is generally produced by treating the organosilane compound in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples thereof include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium; metal chelate compounds having a metal such as Zr, Ti or Al as a central metal. In the present invention, it is preferable to use a metal chelate compound, an acid catalyst of inorganic acids and organic acids. Inorganic acids are preferably hydrochloric acid and sulfuric acid, and organic acids are preferably those having an acid dissociation constant (pKa value (25 ° C.)) of 4.5 or less in water, and further, acid dissociation constants in hydrochloric acid, sulfuric acid and water Is preferably an organic acid having an acid dissociation constant of 2.5 or less in hydrochloric acid, sulfuric acid or water, more preferably an organic acid having an acid dissociation constant of 2.5 or less in water. Specifically, methanesulfonic acid, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

As the metal chelate compound, (wherein, R ³ represents an alkyl group having 1 to 10 carbon atoms) Formula R ³ OH alcohol and R ⁴ COCH ₂ COR ⁵ (formula represented by, R ⁴ is the number of carbon atoms 1 to 10 alkyl groups, R ⁵ is an alkyl group having 1 to 10 carbon atoms or a compound represented by an alkoxy group having 1 to 10 carbon atoms) and selected from Zr, Ti, and Al. Any metal having a central metal as the metal can be used without any particular limitation. Within this category, two or more metal chelate compounds may be used in combination.
The metal chelate compound used in the present invention has the general formula Zr (OR ³ ) _p1 (R ⁴ COCHCOR ⁵ ) _p2 , Ti (OR ³ ) _q1 (R ⁴ COCHCOR ⁵ ) _q2 , and Al (OR ³ ) _r1 (R ⁴ Those selected from the group of compounds represented by COCHCOR ⁵ ) _r2 are preferred and serve to promote the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound.
R ³ and R ⁴ in the metal chelate compound may be the same or different and each is an alkyl group having 1 to 10 carbon atoms, specifically, an ethyl group, n-propyl group, i-propyl group, n-butyl group, sec -Butyl group, t-butyl group, n-pentyl group, phenyl group and the like. R ⁵ represents an alkyl group having 1 to 10 carbon atoms as described above, or an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and n-butoxy. Group, sec-butoxy group, t-butoxy group and the like. Moreover, p1, p2, q1, q2, r1, and r2 in the metal chelate compound represent integers determined so as to be p1 + p2 = 4, q1 + q2 = 4, and r1 + r2 = 3, respectively.

Specific examples of these metal chelate compounds include tri-n-butoxyethylacetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n-propylacetate). Zirconium chelate compounds such as acetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium, diiso Titanium chelate compounds such as propoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum, diisopropyl Poxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, monoacetylacetonate bis (ethyl) An aluminum chelate compound such as acetoacetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonato) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

  In the present invention, it is preferable that a β-diketone compound and / or a β-ketoester compound is further added to the curable composition. This will be further described below.

The β-diketone compound and / or β-ketoester compound represented by the general formula R ⁴ COCH ₂ COR ⁵ is used in the present invention, and is used as a stability improver for the curable composition used in the present invention. It works. Here, R ⁴ represents an alkyl group having 1 to 10 carbon atoms, and R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. That is, by coordinating with a metal atom in the metal chelate compound (zirconium, titanium and / or aluminum compound), the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound by these metal chelate compounds is performed. It is considered that the promoting action is suppressed and the storage stability of the resulting composition is improved. R ⁴ and R ⁵ constituting the β- diketone compound and / or β- ketoester compound are the same as R ⁴ and R ⁵ constituting the metal chelate compound.

Specific examples of the β-diketone compound and / or β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate-n-butyl, acetoacetate. Acetic acid-sec-butyl, acetoacetic acid-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4-octane-dione, 2,4-nonane -Dione, 5-methyl-hexane-dione and the like can be mentioned. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred. These β-diketone compounds and / or β-ketoester compounds may be used alone or in combination of two or more. In the present invention, the β-diketone compound and / or β-ketoester compound is preferably used in an amount of 2 mol or more, more preferably 3 to 20 mol, per 1 mol of the metal chelate compound. Within the above range, good storage stability can be obtained.

The compounding amount of the organosilane compound is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass, and most preferably 1 to 10% by mass based on the total solid content of the low refractive index layer.
The organosilane compound may be added directly to the curable composition (coating liquid for antiglare layer, low refractive index layer, etc.), but the organosilane compound is treated in the presence of a catalyst in advance to prepare the organosilane compound. It is preferable to prepare a silane compound hydrolyzate and / or a partial condensate, and prepare the curable composition using the resulting reaction solution (sol solution). In the present invention, first, the organosilane compound A composition containing a hydrolyzate and / or a partial condensate and a metal chelate compound is prepared, and a liquid obtained by adding a β-diketone compound and / or a β-ketoester compound thereto is added to at least an antiglare layer or a low refractive index layer. It is preferable to coat it in a single layer coating solution.
In the present invention, both the antiglare layer and the low refractive index layer contain a hydrolyzate of organosilane and / or a partial condensate thereof represented by the general formula (4). A cured film formed by applying and curing is preferred.

  5-100 mass% is preferable, the usage-amount of the sol component of the organosilane with respect to a fluorine-containing polymer in a low refractive index layer has more preferable 5-40 mass%, 8-35 mass% is still more preferable, 10-30 mass % Is particularly preferred. If the amount used is small, it is difficult to obtain the effect of the present invention, and if the amount used is too large, the refractive index increases or the shape / surface shape of the film deteriorates.

  An inorganic filler other than the above-described inorganic fine particles can be added to the curable composition in an addition amount within a range that does not impair the desired effect of the present invention. As the inorganic filler, inorganic fine particles described for the antiglare layer are preferable, and it is particularly preferable to add a material that can impart conductivity, such as indium, tin, and antimony, within a range that does not greatly affect the refractive index.

(Sol-gel material)
Various sol-gel materials can also be used as the material for the low refractive index layer. As such a sol-gel material, metal alcoholates (alcohols such as silane, titanium, aluminum, and zirconium), organoalkoxy metal compounds, and hydrolysates thereof can be used. In particular, alkoxysilane, organoalkoxysilane and its hydrolyzate are preferable. Examples of these include tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, etc.), alkyltrialkoxysilane (methyltrimethoxysilane, ethyltrimethoxysilane, etc.), aryltrialkoxysilane (phenyltrimethoxysilane, etc.), dialkyl. Examples thereof include dialkoxysilane and diaryl dialkoxysilane. In addition, organoalkoxysilanes having various functional groups (vinyl trialkoxysilane, methylvinyl dialkoxysilane, γ-glycidyloxypropyltrialkoxysilane, γ-glycidyloxypropylmethyl dialkoxysilane, β- (3,4-epoxy) Cyclohexyl) ethyltrialkoxysilane, γ-methacryloyloxypropyltrialkoxysilane, γ-aminopropyltrialkoxysilane, γ-mercaptopropyltrialkoxysilane, γ-chloropropyltrialkoxysilane, etc.), perfluoroalkyl group-containing silane compounds ( For example, it is also preferable to use (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, etc.). In particular, the use of a fluorine-containing silane compound is preferable from the viewpoint of lowering the refractive index of the layer and imparting water and oil repellency, and it is also preferable to contain the fluorine-containing compound (A) described above.

[Other substances contained in curable composition for low refractive index layer]
In the curable composition, various additives, a radical polymerization initiator, and a cationic polymerization initiator are added to the above-mentioned (A) fluorine-containing compound, (B) inorganic fine particles, and (C) an organosilane compound as necessary. Further, they are prepared by dissolving them in a suitable solvent. At this time, the concentration of the solid content is appropriately selected according to the use, but is generally about 0.01 to 60% by mass, preferably 0.5 to 50% by mass, particularly preferably 1% to 20% by mass. %.

  Curing agents such as polyfunctional (meth) acrylate compounds, polyfunctional epoxy compounds, polyisocyanate compounds, aminoplasts, polybasic acids or anhydrides thereof from the viewpoint of interfacial adhesion with the lower layer directly in contact with the low refractive index layer Can also be added in small amounts. When adding these, it is preferable to set it as the range of 30 mass% or less with respect to the total solid of a low-refractive-index layer film, It is more preferable to set it as the range of 20 mass% or less, The range of 10 mass% or less It is particularly preferable that

In addition, for the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipping properties, a known silicone compound or fluorine compound antifouling agent, slipping agent, and the like may be appropriately added. When these additives are added, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass.

  Preferable examples of the silicone compound include those having a substituent at the terminal and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferred silicone compounds are X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821 (named above), manufactured by Chisso Corporation, FM-0725, FM-7725, FM-4421, FM-5521, FM6621, FM-1121, Gelest DMS-U22, RMS-033, RMS- 083, UMS-182, DMS-H21, DMS-H31, HMS-301, FMS121, FMS123, FMS131, FMS141, FMS221 (named above) but not limited thereto.

As the fluorine compound, a compound having a fluoroalkyl group is preferable. The fluoroalkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and a straight chain (for example, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ) ₄ H, etc.), even branched structures (eg, —CH (CF ₃ ) ₂ , —CH ₂ CF (CF ₃ ) ₂ , —CH (CH ₃ ) CF ₂ CF ₃ , —CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H, etc.), but alicyclic structures (preferably 5-membered or 6-membered rings such as perfluorocyclohexyl groups) , A perfluorocyclopentyl group or an alkyl group substituted with these, and may have an ether bond (for example, —CH ₂ OCH ₂ CF ₂ CF ₃ , —CH ₂ CH ₂ OCH ₂ C). ₄ F ₈ H, —CH ₂ CH ₂ OCH ₂ CH ₂ C ₈ F ₁₇ , —CH ₂ C H ₂ OCF ₂ CF ₂ OCF ₂
CF ₂ H, etc.). A plurality of the fluoroalkyl groups may be contained in the same molecule.
It is preferable that the fluorine-based compound further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, Ltd., R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink Co., Ltd., Megafac F-171. , F-172, F-179A, defender MCF-300 (trade name), etc., but are not limited thereto.

  In addition, the aforementioned silicone compound or fluorine compound, which can be appropriately added for the purpose of imparting properties such as antifouling property, water resistance, chemical resistance and slipperiness, has a molecular structure for the low refractive index layer. (A) It is also preferable to include in the molecular structure of the fluorine-containing compound in the curable composition. That is, it is desirable to contain it in the form of a block or a graph in the molecular structure of the aforementioned fluorine-containing polymer or fluorine-containing sol-gel.

  For the purpose of imparting properties such as dust resistance and antistatic property, a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, or the like may be added as appropriate. These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass, more preferably in the range of 0.05 to 10% by mass of the total solid content of the low n layer. Particularly preferably 0.1 to 5% by mass. Examples of preferred compounds include, but are not limited to, Dainippon Ink Co., Ltd., MegaFace F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

[Solvent for low refractive index layer]
As a solvent used in the coating composition for forming the low refractive index layer of the present invention, it is possible to dissolve or disperse each component, to easily form a uniform surface in the coating process and the drying process, and liquid storage stability. Can be used, and various solvents selected from the viewpoint of having an appropriate saturated vapor pressure can be used. From the viewpoint of the drying load, it is preferable that the main component is a solvent having a boiling point of 100 ° C. or lower at normal pressure and room temperature, and it is more preferable to contain a small amount of a solvent having a boiling point of 100 ° C. or higher in order to adjust the drying speed. .
Examples of the solvent having a boiling point of 100 ° C. or lower include hydrocarbons such as hexane (boiling point 68.7 ° C.), heptane (98.4 ° C.), cyclohexane (80.7 ° C.), benzene (80.1 ° C.), Halogenated carbonization such as dichloromethane (39.8 ° C), chloroform (61.2 ° C), carbon tetrachloride (76.8 ° C), 1,2-dichloroethane (83.5 ° C), trichloroethylene (87.2 ° C) Hydrogens, diethyl ether (34.6 ° C), diisopropyl ether (68.5 ° C), dipropyl ether (90.5 ° C), ethers such as tetrahydrofuran (66 ° C), ethyl formate (54.2 ° C), Esters such as methyl acetate (57.8 ° C.), ethyl acetate (77.1 ° C.), isopropyl acetate (89 ° C.), acetone (56.1 ° C.), 2-butanone (methyl ethyl) Ketones such as Luketone, 79.6 ° C, methanol (64.5 ° C), ethanol (78.3 ° C), 2-propanol (82.4 ° C), 1-propanol (97.2 ° C), etc. Alcohols, cyano compounds such as acetonitrile (81.6 ° C.), propionitrile (97.4 ° C.), carbon disulfide (46.2 ° C.), and the like. Of these, ketones and esters are preferable, and ketones are particularly preferable. Among the ketones, 2-butanone is particularly preferable.
Examples of the solvent having a boiling point of 100 ° C. or more include, for example, octane (125.7 ° C.), toluene (110.6 ° C.), xylene (138 ° C.), tetrachloroethylene (121.2 ° C.), and chlorobenzene (131.7 ° C.). , Dioxane (101.3 ° C), dibutyl ether (142.4 ° C), isobutyl acetate (118 ° C), cyclohexanone (155.7 ° C), 2-methyl-4-pentanone (same as MIBK, 115.9 ° C) 1-butanol (117.7 ° C.), N, N-dimethylformamide (153 ° C.), N, N-dimethylacetamide (166 ° C.), dimethyl sulfoxide (189 ° C.) and the like. Cyclohexanone and 2-methyl-4-pentanone are preferable.

(Formation of layer)
The coating layer used in the present invention, and if necessary, a hard coat layer, a low refractive index layer or other layers are coated with a coating solution on a transparent support, heated and dried, and then, if necessary, The monomer and curable resin for forming each layer are cured by light irradiation and / or heating. Thereby, each layer is formed.

  Although the coating method of each layer of the film of the present invention is not particularly limited, a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, an extrusion coating method (die coating method) ( U.S. Pat. No. 2,681,294) and known methods such as a micro gravure coating method are used. Among them, a micro gravure coating method and a die coating method are preferable, and a die coating method is preferably used in order to supply with high productivity.

  In the present invention, a mode in which a plurality of layers of two or more layers are formed, such as forming a second coating layer on the coating layer or forming a low refractive index layer on a layer having hard coat properties, is preferably used. . At least two of the plurality of layers are continuously applied in the process of feeding from one transparent substrate film to winding with a coating machine having a coating station, a drying zone, and a plurality of UV curing zones as required. Forming is very preferable from the viewpoint of productivity and cost.

  Drying is preferably performed under conditions where the organic solvent concentration in the applied liquid film is 5% by mass or less after drying, more preferably 2% by mass or less, and even more preferably 1% by mass or less. The drying conditions are affected by the thermal strength of the substrate, the conveyance speed, the length of the drying process, and the like, but it is preferable that the organic solvent content is as low as possible in terms of film hardness and adhesion prevention. When an organic solvent is not contained, the drying step can be omitted and ultraviolet irradiation can be performed immediately after coating.

  The coating layer of the present invention may be subjected to heat treatment in order to increase the crystallinity. A preferable heat treatment temperature is 40 ° C. to 130 ° C., and the heat treatment time can be appropriately determined according to the required crystallinity, but is usually about 5 minutes to 48 hours.

  Furthermore, for the purpose of improving the adhesion between the transparent substrate film and the coating layer, one or both surfaces of the transparent substrate film can be subjected to a surface treatment by an oxidation method, an unevenness method, or the like as desired. Examples of the oxidation method include corona discharge treatment, glow discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like.

[Easily adhesive layer]
In the present invention, it will be described that an easy adhesion layer is provided on both sides or one side of the coating layer. The easy adhesion layer may be composed of one layer, or may be composed of two or more layers. In the present invention, it is preferable to provide an easy-adhesion layer having the following two-layer structure between the transparent support / coating layer.
(composition)
First layer: water-dispersible or water-soluble synthetic resin, and carbodiimide compound,
Antistatic layer second layer containing conductive metal oxide particles as essential components: Surface layer containing water-dispersible or water-soluble synthetic resin and crosslinking agent as essential components

The easy adhesion layer is provided with an antistatic layer and a surface layer in this order on a support. In the antistatic layer of the present invention, the haze of the low charging support obtained by providing the antistatic layer on the support is 3% or less, and the surface electrical resistance of the surface layer of the resulting photosensitive material is 1 ×. Conductivity is imparted so as to be in the range of 10 ⁶ to 1 × 10 ¹¹ Ω. By providing the antistatic layer, it is possible to suppress the occurrence of trouble with dust caused by static electricity that occurs in the manufacturing process of handling the plastic support.

  The antistatic layer is a layer containing conductive metal oxide particles, and generally further contains a binder. The conductive metal oxide particles are preferably acicular particles having a major axis to minor axis ratio (major axis / minor axis) in the range of 3 to 50. In particular, those having a major axis / minor axis in the range of 10 to 50 are preferable. The minor axis of such acicular particles is preferably in the range of 0.001 to 0.1 μm, and particularly preferably in the range of 0.01 to 0.02 μm. The major axis is preferably in the range of 0.1 to 5.0 μm, and particularly preferably in the range of 0.1 to 2.0 μm.

As the material of the conductive metal oxide particles, ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃
In ₂ O ₃ , MgO, BaO and MoO ₃ and composite oxides thereof, and metal oxides further containing different atoms in these metal oxides.
As the metal oxide, SnO ₂ , ZnO, Al ₂ O ₃ , TiO ₂ , In ₂ O ₃ and MgO are preferable, SnO ₂ , ZnO, In ₂ O ₂ and TiO ₂ are preferable, and SnO ₂ is particularly preferable. .
Examples of containing a small amount of different atoms include Zn or Al, In, TiO ₂ Nb or Ta, In ₂ O ₃ Sn, and SnO ₂ Sb, Nb or halogen elements. An element doped with 0.01 to 30 mol% (preferably 0.1 to 10 mol%) of the element can be used. When the added amount of the different element is less than 0.01 mol%, sufficient conductivity cannot be imparted to the oxide or composite oxide. When the added amount exceeds 30 mol%, the degree of blackening of the particles increases, and the charge is increased. Since the prevention layer is dark, it is not suitable as a protective film for polarizing plates.
Therefore, in the present invention, the material of the conductive metal oxide particles is preferably one containing a small amount of a different element with respect to the metal oxide or the composite metal oxide. Also preferred are those containing an oxygen defect in the crystal structure.
As the conductive metal oxide particles containing a small amount of the dissimilar atom, SnO ₂ particles are preferred antimony-doped, SnO ₂ particles are preferred which are particularly doped antimony 0.2-2.0 mol%.
Therefore, in the present invention, it is advantageous to use a metal oxide particle such as antimony-doped SnO ₂ having the dimensions of the short axis and the long axis in order to form an antistatic layer that is transparent and has good conductivity. is there. Thereby, the protective film for polarizing plates which has a low-chargeable support body and whose surface electrical resistance of the surface layer is in the range of 1 × 10 ⁶ to 1 × 10 ¹¹ Ω can be easily obtained.

About the reason why an antistatic layer which is transparent and has good conductivity can be advantageously formed by using acicular metal oxide particles having the dimensions of the short axis and the long axis (eg, antimony-doped SnO ₂ ). Is considered as follows.
In the antistatic layer, the needle-like metal oxide particles extend long in the major axis direction parallel to the surface of the antistatic layer, but the length of the minor axis in the thickness direction of the layer. It only occupies. Since such acicular metal oxide particles are long in the major axis direction as described above, they are easier to contact with each other than ordinary spherical particles, and high conductivity can be obtained even in a small amount.
Accordingly, the surface electrical resistance can be reduced without impairing the transparency.
Further, in the needle-like metal oxide particles, the minor axis diameter is usually smaller than or substantially the same as the thickness of the antistatic layer and rarely protrudes on the surface. Therefore, it is almost completely covered by the surface layer provided on the antistatic layer.
Therefore, the advantage that there is almost no occurrence of powder falling, which is the detachment of the protruding portion from the layer, during the transport of the protective film for polarizing plate can be obtained.

The antistatic layer of the present invention generally contains a binder that disperses and supports conductive metal oxide particles. As a material for the binder, various polymers such as an acrylic resin, a vinyl resin, a polyurethane resin, and a polyester resin can be used. From the viewpoint of preventing powder falling, a cured product of a polymer (preferably an acrylic resin, a vinyl resin, a polyurethane resin, or a polyester resin) and a carbodiimide compound is preferable.
In the present invention, from the viewpoint of maintaining a good working environment and preventing air pollution, it is preferable to use either a water-soluble polymer or a carbodiimide compound, or an aqueous dispersion such as an emulsion.
Further, the polymer has any group of a methylol group, a hydroxyl group, a carboxyl group, and an amino group so that a crosslinking reaction with the carbodiimide compound is possible. A hydroxyl group and a carboxyl group are preferred, and a carboxyl group is particularly preferred. The content of hydroxyl group or carboxyl group in the polymer is preferably 0.0001 to 1 equivalent / 1 kg, particularly preferably 0.001 to 1 equivalent / 1 kg.

Acrylic resins include acrylic acid esters such as acrylic acid and alkyl acrylate, acrylamide, acrylonitrile, methacrylic acid esters such as methacrylic acid and alkyl methacrylate, and homopolymers of any monomer of methacrylamide and methacrylonitrile. Or the copolymer obtained by superposition | polymerization of 2 or more types of these monomers can be mentioned.
Among these, homopolymers of monomers of acrylic acid esters such as alkyl acrylates and methacrylic acid esters such as alkyl methacrylates, or copolymers obtained by polymerization of two or more of these monomers preferable. For example, mention may be made of homopolymers of monomers of acrylic acid esters and methacrylic acid esters having an alkyl group having 1 to 6 carbon atoms, or copolymers obtained by polymerization of two or more of these monomers. it can. The acrylic resin has the above composition as a main component and, for example, partially uses a monomer having any group of a methylol group, a hydroxyl group, a carboxyl group, and an amino group so that a crosslinking reaction with a carbodiimide compound is possible. The resulting polymer.

  Examples of the vinyl resin include polyvinyl alcohol, acid-modified polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl methyl ether, polyolefin, ethylene / butadiene copolymer, polyvinyl acetate, vinyl chloride / vinyl acetate copolymer, vinyl chloride / ( A meth) acrylic acid ester copolymer and an ethylene / vinyl acetate copolymer (preferably ethylene / vinyl acetate / (meth) acrylic acid ester copolymer) can be mentioned. Among these, polyvinyl alcohol, acid-modified polyvinyl alcohol, polyvinyl formal, polyolefin, ethylene / butadiene copolymer and ethylene / vinyl acetate copolymer (preferably ethylene / vinyl acetate / acrylic acid ester copolymer) are used. preferable. The vinyl resin can be crosslinked with a carbodiimide compound so that, for example, polyvinyl alcohol, acid-modified polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl methyl ether, and polyvinyl acetate leave a vinyl alcohol unit in the polymer. Thus, the polymer having a hydroxyl group is used, and the other polymer is, for example, a crosslinkable polymer by partially using a monomer having any of a methylol group, a hydroxyl group, a carboxyl group, and an amino group.

  Examples of the polyurethane resin include polyhydroxy compounds (eg, ethylene glycol, propylene glycol, glycerin, trimethylolpropane), aliphatic polyester polyols obtained by reaction of polyhydroxy compounds and polybasic acids, polyether polyols (eg, Polyurethane derived from poly (oxypropylene ether) polyol, poly (oxyethylene-propylene ether) polyol), polycarbonate-based polyol, and polyethylene terephthalate polyol, or a mixture thereof and polyisocyanate can be given. In the polyurethane resin, for example, the hydroxyl group remaining unreacted after the reaction between polyol and polyisocyanate can be used as a functional group capable of crosslinking reaction with a carbodiimide compound.

  As the polyester resin, generally used is a polymer obtained by reacting a polyhydroxy compound (eg, ethylene glycol, propylene glycol, glycerin, trimethylolpropane) with a polybasic acid. In the polyester resin, for example, after the reaction between the polyol and the polybasic acid is completed, the hydroxyl group and carboxyl group remaining unreacted can be used as a functional group capable of crosslinking reaction with the carbodiimide compound. Of course, a third component having a functional group such as a hydroxyl group may be added.

  Among the above polymers, acrylic resins and polyurethane resins are preferable, and acrylic resins are particularly preferable.

As the carbodiimide compound used in the present invention, a compound having a plurality of carbodiimide structures in the molecule is preferably used.
Polycarbodiimide is usually synthesized by a condensation reaction of organic diisocyanate. Here, the organic group of the organic diisocyanate used for the synthesis of the compound having a plurality of carbodiimide structures in the molecule is not particularly limited, and either aromatic or aliphatic, or a mixed system thereof can be used. An aliphatic system is particularly preferred from the viewpoint of reactivity.
As the synthetic raw material, organic isocyanate, organic diisocyanate, organic triisocyanate and the like are used.
As examples of organic isocyanates, aromatic isocyanates, aliphatic isocyanates, and mixtures thereof can be used.
Specifically, 4,4′-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane Diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,3-phenylene diisocyanate, etc. are used. As organic monoisocyanates, isophorone isocyanate, phenyl isocyanate are used. Cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate and the like are used.
Moreover, the carbodiimide type compound that can be used in the present invention is also available as a commercial product such as Carbodilite V-02-L2 (trade name: manufactured by Nisshinbo Co., Ltd.).
The carbodiimide compound of the present invention is preferably added in an amount of 1 to 200% by mass, more preferably 5 to 100% by mass, based on the binder.

  To form the antistatic layer of the present invention, first, for example, a dispersion obtained by dispersing the conductive metal oxide particles as they are or in a solvent such as water (including a dispersant and a binder as necessary) An antistatic layer-forming coating solution is prepared by adding and mixing (dispersing as necessary) an aqueous dispersion or aqueous solution containing the binder (eg, polymer, carbodiimide compound and appropriate additive). The antistatic layer is a coating method generally known on the surface of a plastic film such as polyester (the side where no photosensitive layer is provided), such as dip coating, air knife coating, It can be applied by a curtain coating method, a wire bar coating method, a gravure coating method, an extrusion coating method or the like. The plastic film such as polyester to be applied may be any one before sequential biaxial stretching, before simultaneous biaxial stretching, after uniaxial stretching and before re-stretching, or after biaxial stretching. The surface of the plastic support on which the coating solution for forming the antistatic layer is preferably subjected to surface treatment such as ultraviolet treatment, corona treatment, glow discharge treatment and the like in advance.

The layer thickness of the antistatic layer of the present invention is preferably in the range of 0.01 to 1 μm, more preferably in the range of 0.01 to 0.2 μm. If the coating agent is less than 0.01 μm, it is difficult to uniformly apply the coating agent, and uneven coating tends to occur on the product. If it exceeds 1 μm, the antistatic performance and scratch resistance may be inferior.
The conductive metal oxide particles are preferably contained in the antistatic layer in the range of 10 to 1000% by weight with respect to the binder (eg, the total of the polymer and the carbodiimide compound), and more preferably 100 to 500%. A range of% by weight is preferred. If it is less than 10% by weight, sufficient antistatic properties cannot be obtained, and if it exceeds 1000% by weight, the haze becomes too high.

The antistatic layer of the present invention and the following surface layer can be used in combination with additives such as a matting agent, a surfactant and a slipping agent, if necessary. Examples of the matting agent include particles of oxides such as silicon oxide, aluminum oxide, and magnesium oxide having a particle diameter of 0.001 to 10 μm, and particles of a polymer or a copolymer such as polymethyl methacrylate and polystyrene. Can do.
Examples of the surfactant include known anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants.
Examples of slip agents include natural waxes such as carnauba wax, phosphate esters of higher alcohols having 8 to 22 carbon atoms or amino salts thereof; palmitic acid, stearic acid, behenic acid and esters thereof; and silicone compounds. Can do.

  In the present invention, a surface layer is provided on the antistatic layer. The surface layer is provided mainly to assist the adhesion imparting with the adhesive layer and the anti-detachment function of the conductive metal oxide particles of the antistatic layer. As the material for the surface layer, various polymers such as acrylic resin, vinyl resin, polyurethane resin, and polyester resin can be generally used, and polymers described as the binder in the antistatic layer are preferable.

The crosslinking agent used for the surface layer is preferably an epoxy compound.
As the epoxy compound, 1,4-bis (2 ′, 3′-epoxypropyloxy) butane, 1,3,5-triglycidyl isocyanurate, 1,3-diglycidyl-5- (γ-acetoxy-β-oxy) Propyl) isocyanurate, sorbitol polyglycidyl ethers, polyglycerol polyglycidyl ethers, pentaerythritol polyglycidyl ethers, diglyceryl polyglycidyl ether, 1,3,5-triglycidyl (2-hydroxyethyl) isocyanurate, glycerol Epoxy compounds such as polyglycerol ethers and trimethylolpropane polyglycidyl ethers are preferable, and specific commercial products thereof include, for example, Denacol EX-521 and EX-614B (manufactured by Nagase Kasei Kogyo Co., Ltd.). DOO but it can not be construed as being limited thereto.

  In addition, it can be used in combination with other compounds within the range of addition amounts that do not affect the optical properties. For example, CEKMeers and THJames “The Theory of the Photographic Process” 3rd edition (1966), USA Patent No. 3316095, No. 3232264, No. 3288775, No. 2732303, No. 3363718, No. 33232763, No. 2732316, No. 2586168, No.3103437, No. 3017280, No. 2983611, No. 2725294, Examples thereof include curing agents described in Nos. 2,725,295, 3,100,704, 3,091,537, 3,213,313, 3,543,292 and 3,125,449, British Patents 994869, 1,167,207, and the like.

  As typical examples, melamine compounds containing 2 or more (preferably 3 or more) methylol groups and / or alkoxymethyl groups and their condensation polymers, melamine resins or melamine urea resins, mucochloric acid, Mucobromic acid, mucofenoxycycloic acid, mucophenoxypromic acid, formaldehyde, glyoxal, monomethylglyoxal, 2,3-dihydroxy-1,4-dioxane, 2,3-dihydroxy-5-methyl-1,4-dioxanesuccinaldehyde, Aldehyde compounds such as 2,5-dimethoxytetrahydrofuran and glutaraldehyde and derivatives thereof; divinylsulfone-N, N′-ethylenebis (vinylsulfonylacetamide), 1,3-bis (vinylsulfonyl) -2-propanol, Renbismaleimide, 5-acetyl-1,3-diacryloyl-hexahydro-s-triazine, 1,3,5-triacryloyl-hexahydro-s-triazine and 1,3,5-trivinylsulfonyl-hexahydro-s- Active vinyl compounds such as triazine; 2,4-dichloro-6-hydroxy-s-triazine sodium salt, 2,4-dichloro-6- (4-sulfoanilino) -s-triazine sodium salt, 2,4-dichloro- Active halogen compounds such as 6- (2-sulfoethylamino) -s-triazine and N, N′-bis (2-chloroethylcarbamyl) piperazine; bis (2,3-epoxypropyl) methylpropylammonium · p -Toluenesulfonate, 2,4,6-triethylene-s-triazine, 1,6-hexa Ethyleneimine compounds such as tylene-N, N′-bisethyleneurea and bis-β-ethyleneiminoethylthioether; 1,2-di (methanesulfoneoxy) ethane, 1,4-di (methanesulfoneoxy) butane and Methanesulfonic acid ester compounds such as 1,5-di (methanesulfonoxy) pentane; carbodiimide compounds such as dicyclohexylcarbodiimide and 1-dicyclohexyl-3- (3-trimethylaminopropyl) carbodiimide hydrochloride; 2,5-dimethyliso Isoxazole compounds such as oxazole; inorganic compounds such as chromium alum and chromium acetate; N-carboethoxy-2-isopropoxy-1,2-dihydroquinoline and N- (1-morpholinocarboxy) -4-methylpyri Dehydration condensation type pe Active ester compounds such as N, N'-adipoyldioxydisuccinimide and N, N'-terephthaloyldioxydisuccinimide: toluene-2,4-diisocyanate and 1,6-hexamethylene diisocyanate And the like, and epichlorohydrin compounds such as polyamide-polyamine-epichlorohydrin reactant, but are not limited thereto.

  In order to form the surface layer of the present invention, first, the above polymer, epoxy compound, and appropriate additive are added to and mixed with a solvent such as water (including a dispersant and a binder as necessary). Disperse accordingly) to prepare a surface layer coating solution.

  The surface layer is formed by a coating method generally well-known on the antistatic layer of the present invention, such as a dip coating method, an air knife coating method, a curtain coating method, a wire bar coating method, a gravure coating method, and an extrusion coating method. It can form by apply | coating the said surface layer coating liquid. The layer thickness of the surface layer is preferably in the range of 0.01 to 1 μm, and more preferably in the range of 0.01 to 0.2 μm. If it is less than 0.01 μm, the anti-detachment function of the conductive metal oxide particles of the antistatic layer is insufficient, and if it exceeds 1 μm, it is difficult to uniformly apply the coating agent, and uneven coating tends to occur on the product.

  In the present invention, these formed coating layers and hard coat layers contain an antifouling agent, or contain a low surface energy curable resin containing fluorine and / or silicon, and are cured by irradiation with ultraviolet rays. An antifouling coating layer can be obtained by laminating an antifouling layer mainly composed of an adhesive composition.

  The antifouling agent used in the present invention imparts antifouling properties such as water repellency and oil repellency to the coating layer, such as the preparation of the coating liquid for forming the coating layer and the transparent substrate film Any coating material may be used as long as it has no inconvenience when applied to the surface and exhibits water repellency and oil repellency on the surface of the antifouling coating layer when the antifouling coating layer is formed. Examples thereof include a cured resin containing fluorine and / or silicon.

[Curable resin containing fluorine and / or silicon]
The curable resin containing fluorine and / or silicon contained in the coating layer or antifouling layer used in the present invention includes a known fluorine curable resin, silicon curable resin, or fluorine and silicon-containing part. A curable resin having a block is exemplified, and a curable resin containing a segment having good compatibility with the resin or metal oxide and a segment containing fluorine or silicon is preferable, and the coating layer or the antifouling layer is obtained. By adding, fluorine or silicon can be unevenly distributed on the surface.

  Specific examples of these curable resins include block copolymers or graft copolymers of fluorine- or silicon-containing monomers and other hydrophilic or lipophilic monomers. Examples of the fluorine-containing monomer include perfluoroalkyl group-containing (meth) acrylic acid esters such as hexafluoroisopropyl acrylate, heptadecafluorodecyl acrylate, perfluoroalkylsulfonamidoethyl acrylate, and perfluoroalkylamidoethyl acrylate. . Examples of the silicon-containing monomer include monomers having a siloxane group by a reaction such as polydimethylsiloxane and (meth) acrylic acid. Hydrophilic or lipophilic monomers include (meth) acrylic acid esters such as methyl acrylate, hydroxyl-containing polyester and (meth) acrylic acid ester at the terminal, hydroxyethyl (meth) acrylate, and polyethylene glycol (meth) acrylic acid Examples include esters.

  Commercially available curable resins include acrylic oligomers having a perfluoroalkyl chain microdomain structure, such as “Defenser MCF-300”, “Defenser MCF-312”, “Defenser MCF-323”, etc. “Megafac F-170”, “Megafac F-173”, “Megafac F-175”, etc. of oligomers containing oily groups, “Megafac F-171”, etc. of oligomers containing perfluoroalkyl groups / hydrophilic groups { As described above, manufactured by Dainippon Ink & Chemicals, Inc., and fluorinated alkyl-based “Modiper F-200” and “Modiper”, which are block polymers of vinyl monomers composed of a segment having excellent surface migration and a segment compatible with the resin. F-220 "," Modiper F-600 "," Modiper F-820 ", etc. "Modiper FS-700" silicon-based "Modiper FS-710", etc. {above, NOF Corp.} are exemplified.

  In order to provide an antifouling layer on the coating layer, a curable resin having a low surface energy and containing fluorine atoms is preferred. Specifically, JP-A-57-34526 and JP-A-2-19811 are preferred. Examples thereof include a silicon curable resin containing a fluorinated hydrocarbon group and a fluorinated hydrocarbon group-containing polymer described in JP-A-3-17901.

  When producing a polarizing plate using the protective film for polarizing plates of the present invention as at least one of the surface protective films of two polarizing films, the protective film for polarizing plates is opposite to the coating layer. It is preferable to improve the adhesion on the adhesive surface by hydrophilizing the surface of the transparent substrate film, that is, the surface to be bonded to the polarizing film. The hydrophilized surface is effective for improving the adhesiveness with the adhesive layer mainly composed of polyvinyl alcohol. As the hydrophilic treatment, the following saponification treatment is preferably performed.

[Saponification]
(1) Method of immersing in alkaline solution This is a technique in which a protective film for polarizing plate is immersed in an alkaline solution under appropriate conditions, and all surfaces having reactivity with alkali on the entire surface of the film are saponified. It is preferable from the viewpoint of cost because it does not require any equipment. The alkaline liquid is preferably a sodium hydroxide aqueous solution. A preferred concentration is 0.5 to 3 mol / L, particularly preferably 1 to 2 mol / L. The liquid temperature of a preferable alkali liquid is 30-75 degreeC, Most preferably, it is 40-60 degreeC.
The combination of the saponification conditions is preferably a combination of relatively mild conditions, but can be set according to the material and configuration of the light scattering film and the antireflection film, and the target contact angle.
After being immersed in the alkaline solution, it is preferable to sufficiently wash with water or neutralize the alkaline component by immersing in a dilute acid so that the alkaline component does not remain in the film.

By saponification treatment, the surface opposite to the surface having the antiglare layer or antireflection layer of the transparent support is hydrophilized. The protective film for polarizing plate is used by adhering the hydrophilic surface of the transparent support to the polarizing film.
The hydrophilized surface is effective for improving the adhesiveness with the adhesive layer mainly composed of polyvinyl alcohol.
In the saponification treatment, the lower the contact angle with water on the surface of the transparent support opposite to the side having the antiglare layer or the low refractive index layer, the better from the viewpoint of adhesiveness to the polarizing film. At the same time, since it is damaged by alkali from the surface having the antiglare layer and the low refractive index layer to the inside, it is important to set the reaction conditions to the minimum necessary. When the contact angle to water of the transparent support on the opposite surface is used as an index of damage to each layer due to alkali, particularly when the transparent support is triacetylcellulose, preferably 10 to 50 degrees, more preferably Is 30 to 50 degrees, more preferably 40 to 50 degrees. If it is 50 degrees or more, there is a problem in the adhesion to the polarizing film, which is not preferable. On the other hand, if it is less than 10 degrees, the damage is too great, and physical strength is impaired.

(2) Method of applying alkaline solution As a means for avoiding damage to each film in the above-mentioned immersion method, the alkaline solution is applied only to the surface opposite to the surface having the antiglare layer or the low refractive index layer under appropriate conditions. An alkaline solution coating method of coating, heating, washing with water and drying is preferably used. The application in this case means that an alkaline solution or the like is brought into contact only with the surface to be saponified, and in addition to the application, it may be carried out by spraying or contacting a belt containing the solution. Including. By adopting these methods, a separate facility and process for applying an alkaline solution are required, which is inferior to the immersion method (1) from the viewpoint of cost. On the other hand, since the alkali solution contacts only the surface to be saponified, the opposite surface can have a layer using a material that is weak against the alkali solution. For example, vapor deposition films and sol-gel films have various effects such as corrosion, dissolution, and peeling due to alkali solution, so it is not desirable to use the immersion method. Is possible.

  In any of the saponification methods (1) and (2), since each layer can be formed after being unwound from a roll-shaped support, a series of steps are added in addition to the above-described antiglare antireflection film production process. You may carry out by operation. Furthermore, the polarizing plate can be produced more efficiently than the same operation with a single wafer by continuously performing the pasting step with the polarizing plate made of the unwound support.

(3) Method of protecting and saponifying an antiglare layer and an antireflection layer with a laminate film When the antiglare layer and / or the low refractive index layer is insufficient in resistance to an alkaline solution as in the above (2) Then, after forming the final layer, the laminate film is bonded to the surface on which the final layer is formed and then immersed in an alkaline solution to hydrophilize only the surface of the triacetyl cellulose opposite to the surface on which the final layer is formed. After being laminated, the laminate film can be peeled off. Even in this method, only the surface opposite to the surface on which the final layer of the triacetyl cellulose film is formed is subjected to the hydrophilization treatment necessary for the polarizing plate protective film without damaging the antiglare layer and the low refractive index layer. be able to. Compared with the method (2), there is an advantage that a laminate film is generated as waste, but a device for applying a special alkaline solution is unnecessary.

(4) Method of immersing in alkaline solution after forming up to antiglare layer Up to antiglare layer is resistant to alkaline solution, but when low refractive index layer is insufficiently resistant to alkaline solution, after forming up to antiglare layer It is also possible to soak both surfaces in an alkali solution to hydrophilize both surfaces, and then form a low refractive index layer on the antiglare layer. Although the manufacturing process becomes complicated, there is an advantage that the interlayer adhesion between the antiglare layer and the low refractive index layer is improved particularly when the low refractive index layer has a hydrophilic group such as a fluorine-containing sol-gel film.

(5) Method of forming a coating on a previously saponified triacetyl cellulose film Saponification is performed by immersing a triacetyl cellulose film in an alkaline solution in advance, and a coating layer is formed directly on one side or via another layer. May be formed. In the case of saponification by dipping in an alkaline solution, interlayer adhesion between the coating layer and the triacetyl cellulose surface hydrophilized by saponification may deteriorate. In such a case, after saponification, only the surface on which the coating layer is to be formed is treated by corona discharge, glow discharge, etc. to remove the hydrophilic surface and then form an antiglare layer or other layer. I can deal with it. Further, when the antiglare layer or other layer has a hydrophilic group, the interlayer adhesion may be good.

  Below, the polarizing plate using the protective film for polarizing plates of this invention and the liquid crystal display device using this polarizing plate are demonstrated.

(Preparation of polarizing film)
The protective film (optical film) for polarizing plates of the present invention constitutes a polarizing plate by sticking to at least one surface of a polarizer. The other surface of the polarizer is preferably laminated with a protective film for polarizing plate having a moisture permeability of 700 to 3000 g / m ² · day, more preferably 1000 to 1700 g / m ² · day. Usually used TAC is preferably used.
A normal cellulose acetate film may be used, but a cellulose acetate film manufactured by a solution casting method and stretched in the width direction in the form of a roll film at a stretching ratio of 10 to 100% may be used.
Furthermore, in the polarizing plate of the present invention, one side is the protective film for polarizing plate of the present invention, whereas the other protective film is an optical compensation film having an optically anisotropic layer made of a liquid crystalline compound. good.
In the polarizing plate of the present invention, one side is the protective film for polarizing plate of the present invention, whereas the other protective film is a film having Re of 0 to 10 nm and Rth of -20 to 20 nm (for example, JP 2005-301227, paragraph number [0095]).

  Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film.

Of the two protective films of the polarizer, the film other than the polarizing plate protective film of the present invention is preferably an optical compensation film having an optical compensation layer comprising an optically anisotropic layer. The optical compensation film (retardation film) can improve the viewing angle characteristics of the liquid crystal display screen.
A known film can be used as the optical compensation film, but the optical compensation film described in JP-A-2001-100042 is preferable in terms of widening the viewing angle.

  When the polarizing plate protective film of the present invention is used together with a liquid crystal display device or the like, it is preferably disposed on the viewing side opposite to the liquid crystal cell.

<Liquid crystal display device>
The film and polarizing plate of the present invention can be advantageously used in a liquid crystal display device such as a liquid crystal display device, and is preferably used as the outermost layer of the display.
The liquid crystal display device has a liquid crystal cell and two polarizing plates arranged on both sides thereof, and the liquid crystal cell carries a liquid crystal between two electrode substrates. Furthermore, one optically anisotropic layer may be disposed between the liquid crystal cell and one polarizing plate, or two optically anisotropic layers may be disposed between the liquid crystal cell and both polarizing plates.

  The liquid crystal cell is preferably in TN mode, VA mode, OCB mode, IPS mode or ECB mode.

<TN mode>
In the TN mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and are twisted and aligned at 60 to 120 °.
The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.

<VA mode>
In a VA mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied.
The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of Tech. Papers (Proceedings) 28 (1997) 845 in which the VA mode is converted into a multi-domain (for MVA mode) in order to enlarge the viewing angle. ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).

<OCB mode>
The OCB mode liquid crystal cell is a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in substantially opposite directions (symmetrically) at the upper and lower portions of the liquid crystal cell. US Pat. No. 4,583,825, No. 5,410,422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. Therefore, this liquid crystal mode is called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

<IPS mode>
The IPS mode liquid crystal cell is a type in which a nematic liquid crystal is switched by applying a lateral electric field. IDRC (Asia Display '95), p. 577-580 and p. 707-710.

<ECB mode>
In the ECB mode liquid crystal cell, rod-like liquid crystalline molecules are substantially horizontally aligned when no voltage is applied. The ECB mode is one of the liquid crystal display modes having the simplest structure, and is described in detail in, for example, Japanese Patent Application Laid-Open No. 5-203946.

<Brightness enhancement film>
As the brightness enhancement film, a polarization conversion element having a function of separating light emitted from a light source (backlight) into transmitted polarized light, reflected polarized light, or scattered polarized light is used. Such a brightness enhancement film can improve the emission efficiency of linearly polarized light by using retroreflected light from a reflected polarized light or scattered polarized light backlight.
An example is an anisotropic reflective polarizer. An anisotropic reflective polarizer includes an anisotropic multiple thin film that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in the other vibration direction.
An example of the anisotropic multi-thin film is DBM manufactured by 3M (see, for example, JP-A-4-268505).
An example of the anisotropic reflective polarizer is a composite of a cholesteric liquid crystal layer and a λ / 4 plate. An example of such a composite is PCF manufactured by Nitto Denko (see JP-A-11-231130, etc.). An example of the anisotropic reflective polarizer is a reflective grid polarizer.
As a reflective grid polarizer, a metal grid reflective polarizer (see US Pat. No. 6,288,840, etc.) in which metal is finely processed to produce reflected polarized light in the visible light region, metal fine particles are placed in a polymer matrix. And the like (see JP-A-8-184701, etc.).
Moreover, an anisotropic scattering polarizer is mentioned. An example of the anisotropic scattering polarizer is DRP manufactured by 3M (see US Pat. No. 5,825,543).
Furthermore, there is a polarizing element that can perform polarization conversion in one pass. For example, the one using smectic C * can be mentioned (see JP 2001-201635 A). An anisotropic diffraction grating can be used.
The polarizing plate of the present invention can be used together with a brightness enhancement film. In the case of using a brightness enhancement film, it is more preferable that the polarizing plate and the brightness enhancement film are in close contact with each other in order to prevent moisture from entering the polarizing plate and suppress light leakage. The adhesive for bonding the polarizing plate and the brightness enhancement film is not particularly limited. For example, acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate / vinyl chloride copolymer, modified polyolefin, epoxy-based, fluorine-based, natural rubber, synthetic rubber and other rubber-based polymers Can be appropriately selected and used. In particular, those excellent in optical transparency, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties and excellent in weather resistance, heat resistance and the like can be preferably used.

<Touch panel>
The film of the present invention can be applied to touch panels described in JP-A-5-127822 and JP-A-2002-48913.

<Organic EL device>
The film of the present invention can be used as a substrate (base film) such as an organic EL element or a protective film.
When the film of the present invention is used for an organic EL device or the like, JP-A-11-335661, JP-A-11-335368, JP-A-2001-192651, JP-A-2001-192652, JP-A-2001-192653, JP-A-2001-335776, JP-A-2001-247859, JP-A-2001-181616, JP-A-2001-181617, JP-A-2002-181816, JP-A-2002-181617, JP-A-2002-056776, etc. The contents described in each publication can be applied. Moreover, it is preferable to use together with the content of each gazette of Unexamined-Japanese-Patent No. 2001-148291, Unexamined-Japanese-Patent No. 2001-221916, and Unexamined-Japanese-Patent No. 2001-231443.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, the embodiment of this invention is not limited to these.

<Preparation of coating solution>
[Coating layer coating solution 1]
Chlorine-containing polymer: R204 12g
{"Saran Resin R204" manufactured by Asahi Kasei Life & Living Co., Ltd.}
Tetrahydrofuran 63g

[Coating layer coating solution 2]
Chlorine-containing polymer: 10g
{90% by mass of vinylidene chloride, 10% by mass of acrylate ester, mass average molecular weight 7 × 10 ⁴ , melting point 145 ° C.}
UV absorber 0.8g
{BASF YUBINAR D-50}
Tetrahydrofuran 42g
Toluene 18g

[Coating layer coating solution 3]
Chlorine-containing polymer: 9.241 g of R241C
{"Saran Resin R241C" manufactured by Asahi Kasei Life & Living Co., Ltd.}
MEK (methyl ethyl ketone) 22.5 g
Cyclohexanone 2.50g
Sirisia (Fuji Silysia) 0.034g
Paraffin wax (manufactured by Nippon Seiwa) 0.11 g

[Coating layer coating solution 4]
Chlorine-containing polymer: F216 9.62 g
{"Saran Resin F216" manufactured by Asahi Kasei Life & Living Co., Ltd.}
MiBK (methyl isobutyl ketone) 10.0 g
Cyclohexanone 15.0g
Sirisia (Fuji Silysia) 0.034g
Paraffin wax (manufactured by Nippon Seiwa) 0.11 g

[Coating layer coating solution 5]
A coating layer coating solution 5 was prepared in the same manner as the coating layer coating solution 4 except that the amount of MiBK / cyclohexanone added to the coating layer coating solution 4 was changed to 5.0 g / 20.0 g.

[Coating layer coating solution 6]
A coating layer coating solution 6 was prepared in the same manner as the coating layer coating solution 4 except that the amount of MiBK / cyclohexanone added to the coating layer coating solution 4 was changed to 0 g / 25.0 g.

[Coating layer coating solution 7]
A coating layer coating solution 7 was prepared in the same manner as the coating layer coating solution 4 except that the addition amount of MiBK / cyclohexanone in the coating layer coating solution 4 was changed to 20.0 g / 5.0 g.

[Coating layer coating solution 8]
A coating layer coating solution 8 was prepared in the same manner as the coating layer coating solution 4 except that the amount of MiBK / cyclohexanone added to the coating layer coating solution 4 was changed to 25.0 g / 0 g.

[Coating layer coating solution 9]
-Chlorine-containing polymer: 10.0 g of R204
{"Saran Resin R204" manufactured by Asahi Kasei Life & Living Co., Ltd.}
・ Tetrahydrofuran 68.0g
{Stabilizer containing BHT 250PPM}
・ Toluene 22.0g
・ MXS-300 0.02g
{Manufactured by Soken Chemical Co., Ltd .: 3 μm cross-linked PMMA particle classification enhanced product}
・ UV absorber UV-2 0.5g
{"TINUVIN329" manufactured by Ciba Specialty Chemicals Co., Ltd.}

[Coating layer coating solution 10]
Instead of MXS-300 in coating solution 9 for coating layer, MX-180TA {manufactured by Soken Chemical Co., Ltd., 1.8 μm highly crosslinked PMMA particles} was changed to 0.05 g, and was the same as coating solution 9 for coating layer Thus, a coating layer coating solution 10 was prepared.

[Coating liquid 11 for coating layer]
-Chlorine-containing polymer: L549B 20.0g
{"Saran Latex L549B" manufactured by Asahi Kasei Life & Living Co., Ltd.}
・ Distilled water 45.0g
・ MXS-300 0.02g
{Manufactured by Soken Chemical Co., Ltd .: 3 μm cross-linked PMMA particle classification enhanced product}
・ UV absorber UV-2 0.5g
{"TINUVIN329" manufactured by Ciba Specialty Chemicals Co., Ltd.}

[Coating liquid S1 for easy adhesion layer]
Styrene butadiene latex (solid content 43%) 300g
2,4-dichloro- 6hydroxy -s-triazine sodium salt (8%) 49 g distilled water 1,600 g

[Coating liquid S2 for easy adhesion layer] -First layer coating liquid (for antistatic layer)-
Distilled water 781.7 parts by mass Polyacrylic resin (Julimer ET-410: manufactured by Nippon Pure Chemicals, solid content 30%)
30.9 parts by mass Needle-like structure tin oxide particles (FS-10D: Ishihara Sangyo, solid content 20%)
131.1 parts by mass Carbodiimide compound (Carbodilite V-02-L2: Nisshinbo, solid content 40%)
6.4 parts by mass Surfactant (Sandet BL: Sanyo Chemical Industries, solids 44.6%) 1.4 parts by mass Surfactant (Naroacty HN-100: Sanyo Chemical Industries, 100% solids)
0.7 parts by mass Silica fine particle dispersion (Seahoster KE-W30: Nippon Shokubai 0.3 μm, solid content 20 %) 5.0 parts by mass

-2nd layer coating solution (for surface layer)-
Distilled water 941.0 parts by mass Polyacrylic resin (Julimer ET-410: manufactured by Nippon Pure Chemicals, solid content 30%) 57.3 parts by mass Epoxy compound (Denacol EX-521: manufactured by Nagase Chemicals, solid content 100%)
1.2 parts by mass
Surfactant (Sandet BL: manufactured by Sanyo Chemical Industries, solid content: 44.6%) 0.5 parts by mass

[Coating solution S3 for easy adhesion layer]
-First layer coating solution-
Distilled water 823.0 parts by mass Styrene-butadiene copolymer latex (Nipol Latex LX407C5: ZEON Corporation solid content 40%) 151.5 parts by mass 2,4-dichloro-6-hydroxy-s-triazine sodium salt (H- 232: Sankyo Chemical Co., Ltd., solid content 8%) 25.0 parts by mass Polystyrene fine particles (average particle size 2 μm)
(Nipol UFN1008: Nippon Zeon solid content 10%) 0.5 parts by mass

-Layer 2 coating solution-
Distilled water 982.4 parts by weight Gelatin (alkali treatment) 14.8 parts by weight Methyl cellulose (TC-5: manufactured by Shin-Etsu Chemical Co., Ltd.) 0.46 parts by weight The following compound (Cpd-21) 0.33 parts by weight
Proxel (Cpd-22 solid content 3.5%) 2.0 parts by mass

[Preparation of coating solution for hard coat layer]
(Preparation of sol solution a)
In a 1,000 ml reaction vessel equipped with a thermometer, nitrogen introduction tube and dropping funnel, 187 g (0.80 mol) acryloxypropyltrimethoxysilane, 27.2 g (0.20 mol) methyltrimethoxysilane, 320 g (10 mol) methanol ) And 0.06 g (0.001 mol) of KF, and 15.1 g (0.86 mol) of water was slowly added dropwise at room temperature with stirring. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours, and then heated and stirred for 2 hours under methanol reflux.
Then, 120 g of sol liquid a was obtained by depressurizingly distilling a low boiling point and further filtering. As a result of GPC measurement of the substance thus obtained, the mass average molecular weight was 1,500, and among the components higher than the oligomer component, the component having a molecular weight of 1,000 to 20,000 was 30%.
Moreover, from the measurement result of ¹ H-NMR, the structure of the obtained substance was a structure represented by the following general formula.

Furthermore, the condensation rate α as determined by ²⁹ Si-NMR was 0.56. From this analysis result, it was found that the silane coupling agent sol was mostly composed of a linear structure.
From the gas chromatography analysis, the raw material acryloxypropyltrimethoxysilane had a residual rate of 5% or less.

(1) Preparation of coating solution for light scattering layer
[Composition of coating liquid 1 for hard coat layer]
PET-30 40.0g
DPHA 10.0g
Irgacure 184 2.0g
SX-350 (30%) 2.0g
Cross-linked acrylic-styrene particles (30%) 13.0 g
FP-13 0.06g
Sol liquid a 11.0g
Toluene 38.5g

[Composition of hard coat layer coating solution 2]
PET-30 50.0g
Irgacure 184 2.0g
SX-350 (30%) 2.0g
Cross-linked acrylic-styrene particles (30%) 13.0 g
FP-13 0.06g
Sol liquid a 11.0g
Toluene 28.5g
Cyclohexanone 10.0g

[Composition of coating liquid 3 for hard coat layer]
PET-30 28.0g
DPHA 12.0g
Agglomerated silica (secondary agglomerated diameter 1.5 μm) 5.0 g
Irgacure 184 1.0g
Irgacure 907 0.2g
FP-13 0.08g
MiBK 40.0g
Cyclohexanone 15.0g

[Composition of coating liquid 4 for hard coat layer]
PET-30 46.0g
Irgacure 184 1.7g
MX-600 (30%) 28.6g
FP-13 0.06g
Sol liquid a 7.0g
MiBK 13.0g
MEK (methyl ethyl ketone) 6.0 g

[Composition of coating liquid 5 for hard coat layer]
PET-30 46.0g
DPHA 10.0g
Irgacure 184 2.0g
FP-13 0.06g
Sol liquid a 7.0g
MiBK 13.0g
MEK 6.0g

[Composition of hard coat layer coating solution 6]
Desolite Z7404 100.0g
DPHA 31.0g
KBM-5103 10.0g
KEP-150 8.9g
MXS-300 3.4g
MEK 29.0g
MiBK 13.0g

[Composition of hard coat layer coating solution 7]
CAP482-20 2.4g
Cyclomer P 13.4g
DPHA 16.3g
Irgacure 184 1.2g
MEK 51.0g
Butanol 14.0g
Propylene glycol monomethyl ether 3.5g

  The coating liquid was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare hard coating layer coating liquids 1 to 7.

The compounds used when preparing the above coating solutions for hard coat layers are shown below.
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate [manufactured by Nippon Kayaku Co., Ltd.]
PET-30: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [manufactured by Nippon Kayaku Co., Ltd.]
・ Irgacure 184: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]
・ Irgacure 907: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]
SX-350: average particle size 3.5 μm crosslinked polystyrene particles [refractive index 1.60, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion, used after dispersion for 20 minutes at 10,000 rpm with a Polytron disperser]
Crosslinked acrylic-styrene particles: average particle size 3.5 μm [refractive index 1.55, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion, used after dispersion for 20 minutes at 10,000 rpm with a Polytron disperser]
・ FP-13 fluorine surface modifier

MX-600:
Average particle size 6 μm PMMA particles [refractive index 1.49, manufactured by Soken Chemical Co., Ltd., 30% MiBK dispersion, used after dispersion for 20 minutes at 10,000 rpm with a Polytron disperser]
-Agglomerated silica: secondary agglomerated diameter 1.5 μm (primary particle size of several tens of nm), [manufactured by Nippon Silica Co., Ltd.]
Desolite Z7404: Photopolymerizable hard coat composition liquid containing zirconia fine particles [manufactured by JSR Corporation]
KBM-5103: γ-acryloyloxypropyltrimethoxysilane [manufactured by Shin-Etsu Chemical Co., Ltd.]
KE-P150: 1.5 μm silica particles [manufactured by Nippon Shokubai Co., Ltd.]
MXS-300: 3 μm cross-linked PMMA particles [manufactured by Soken Chemical Co., Ltd.]
CAP482-20: cellulose acetate propionate [manufactured by Eastman Chemical Co.]
・ Cyclomer P: Reactive oligomer [manufactured by Daicel UCB Co., Ltd.]

[Preparation of coating solution for low refractive index layer]
-Synthesis of perfluoroolefin copolymer (1)-
In an autoclave with a stirrer made of stainless steel having an internal volume of 100 ml, 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether, and 0.55 g of dilauroyl peroxide were charged, and the inside of the system was deaerated and replaced with nitrogen gas. Further, 25 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 0.53 Mpa (5.4 kg / cm ² ). The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 0.31 MPa (3.2 kg / cm ² ), the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. After drying, 28 g of polymer was obtained. Next, 20 g of the polymer was dissolved in 100 ml of N, N-dimethylacetamide, and 11.4 g of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 19 g of a perfluoroolefin copolymer (1) represented by the following structural formula. The resulting polymer had a refractive index of 1.421.

-Preparation of sol solution b-
A stirrer, a reactor equipped with a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts of diisopropoxyaluminum ethyl acetoacetate were added and mixed. Thereafter, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain a sol solution b. The mass average molecular weight was 1,600, and among the components higher than the oligomer component, the component having a molecular weight of 1,000 to 20,000 was 100%. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

-Preparation of dispersion A-
Hollow silica fine particle sol (isopropyl alcohol silica sol, average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20 mass%, silica particle refractive index 1.31, prepared by changing the size according to Preparation Example 4 of JP-A-2002-79616 ) 30 g of acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 1.5 g of diisopropoxyaluminum ethyl acetate were added to and mixed with 500 g, and 9 g of ion-exchanged water was added. After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature, and 1.8 g of acetylacetone was added. While adding cyclohexanone to 500 g of this dispersion so that the silica content was almost constant, solvent substitution was performed by distillation under reduced pressure at a pressure of 20 kPa. There was no generation of foreign matter in the dispersion, and the viscosity when adjusted to a solid content concentration of 20% by mass with cyclohexanone was 5 mPa · s at 25 ° C. When the residual amount of isopropyl alcohol in the obtained dispersion A was analyzed by gas chromatography, it was 1.5%.

[Preparation of coating solution 1 for low refractive index layer]
Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.44 containing polysiloxane and hydroxyl group (JTA113, solid content concentration 6%, manufactured by JSR Corporation) 13 g, colloidal silica dispersion MEK-ST-L (trade name, average) Particle size 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Co., Ltd.) 1.3 g, sol solution b 0.65 g, methyl ethyl ketone 4.4 g, cyclohexanone 1.2 g were added, and after stirring, made of polypropylene with a pore size of 1 μm It filtered with the filter and the low refractive index layer coating liquid 1 was prepared. The refractive index of the layer formed with this coating solution was 1.45.

[Preparation of coating solution 2 for low refractive index layer]
8. Heat-crosslinkable fluorine-containing polymer (fluorine-containing silicone thermosetting polymer described in Example 1 of JP-A-11-189621), 37.6 g, curing agent (Cymel 303; trade name, manufactured by Nippon Cytec Industries Co., Ltd.) 40 g, 0.92 g of a curing catalyst (Catalyst 4050; trade name, manufactured by Nippon Cytec Industries Co., Ltd.) was dissolved in 500 g of methyl ethyl ketone, and 195 parts by mass of dispersion A (silica + surface treatment agent 39. 0 parts by mass), colloidal silica dispersion (silica, MEK-ST particle size difference product, average particle size 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Co., Ltd.) 30.0 parts by mass (as solid content 9. 0 mass parts), sol liquid b 17.0 mass parts (5.0 mass parts as solid content), PM980M (photopolymerization initiator, manufactured by Wako Pure Chemical Industries) 0.3 quality Part was added. Was added. The coating liquid 2 for low refractive index layer was prepared by diluting with cyclohexane and methyl ethyl ketone so that the solid content concentration of the entire coating liquid was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 8 to 92. The refractive index of the layer formed with this coating solution was 1.39.

[Preparation of coating solution 3 for low refractive index layer]
Perfluoroolefin copolymer (1) 15.4 g, hollow silica sol (refractive index 1.31, average particle size 60 nm, solid content 20%) 2.2 g, reactive silicone X-22-164C (trade name; Shin-Etsu) (Manufactured by Chemical Industry Co., Ltd.) 0.3 g, sol liquid b 7.3 g, photopolymerization initiator (Irgacure 907 (trade name), Ciba Specialty Chemicals Co., Ltd.) 0.76 g, methyl ethyl ketone 298 g, cyclohexanone 12. After adding 0 g and stirring, the mixture was filtered through a polypropylene filter having a pore diameter of 5 μm to prepare a coating solution 3 for a low refractive index layer. The refractive index of the layer formed by this coating solution was 1.40.

[Preparation of coating solution 4 for low refractive index layer]
Ethylenically unsaturated group-containing fluorine-containing polymer (fluorine polymer (A-1) described in Production Example 3 of JP-A-2005-89536) 45.0 g as a solid content is dissolved in 500 g of methyl isobutyl ketone, and dispersion A 195 parts by mass (silica + 39.0 parts by mass as surface treatment agent solids), colloidal silica dispersion (silica, MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30%, Nissan Chemical ( Co., Ltd.) 30.0 parts by mass (9.0 parts by mass as solids), sol liquid b 17.0 parts by mass (5.0 parts by mass as solids), PM980M (photopolymerization initiator, manufactured by Wako Pure Chemical Industries, Ltd.) 2.0 parts by weight were added. A coating solution 4 for a low refractive index layer was prepared by diluting with methyl ethyl ketone so that the solid content concentration of the entire coating solution was 6% by mass. The refractive index of the layer formed with this coating solution was 1.38.

[Preparation of coating solution 5 for low refractive index layer]
2.65 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.), silica dispersion A (hollow silica dispersion, solid concentration 20%) 30.0 g, sol solution b 2.93 g, reactive silicone X-22-164C (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.) 0.15 g, fluorine-containing compound F3035 (trade name; manufactured by Nippon Oil & Fats Co., Ltd., solid content concentration 30%) 0.15 g, 0.20 g of photopolymerization initiator (Irgacure 907 (trade name), manufactured by Ciba Specialty Chemicals Co., Ltd.), 103 g of methyl ethyl ketone, and 3.5 g of cyclohexanone were added, stirred, and then filtered through a polypropylene filter having a pore size of 1 μm. Thus, a coating solution 5 for a low refractive index layer was prepared.

[Preparation of coating solution 6 for low refractive index layer]
Opstar JTA105 (manufactured by JSR Corporation, solid content: 5 mass%) as a fluorine compound having a fluoroalkyl group and a polysiloxane structure, 100 mass parts, Opstar JTA105A (manufactured by JSR Corporation, solid content: 5 mass%), 1 mass part, 151.5 parts by mass of butyl acetate and 164.0 parts by mass of Colcoat N103X (manufactured by Colcoat Co., Ltd., number average molecular weight 950 in terms of ethylene glycol, solid content: 2% by mass) as a siloxane oligomer were mixed. Further, hollow silica fine particle sol (isopropyl alcohol silica sol, average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20% by mass, silica particle refractive index 1.31, size was changed according to Preparation Example 4 of JP-A-2002-79616. Preparation) 42.5 g was added to prepare a coating solution 6 for a low refractive index layer.

(Example 1)
(Preparation of protective film for polarizing plate)
<Coating of easy-adhesion layer 1>
An 80 μm-thick triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) is unwound in a roll form (width 1,340 mm, total length 3,900 m), and one side (adhesive interface with the coating layer) The coating liquid S1 for an easy adhesion layer was applied to the surface to be 90 nm so that the dry film thickness was 90 nm.

<Coating layer coating>
An 80 μm-thick triacetylcellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) coated with the easy-adhesion layer 1 is unrolled in a roll form, and coated with a coater having a throttle die. The liquid 1 was applied by extruding directly onto the surface on which the easy-adhesion layer S1 of the protective film for polarizing plate on the backup roll was applied. It apply | coated on conditions with a conveyance speed of 30 m / min, dried at 60 degreeC for 5 minutes, and wound up.

<Coating of easy-adhesion layer 2>
An 80 μm-thick triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) coated with the easy-adhesion layer 1 and the coating layer is unrolled in a roll form and applied to the easy-adhesion layer on the coating layer. The liquid S1 was applied so that the dry film thickness was 90 nm.

<Coating of hard coat layer>
A 80 μm thick triacetylcellulose film (TAC-TD80U, manufactured by FUJIFILM Corporation) coated with an easy-adhesion layer 1, a coating layer, and an easy-adhesion layer 2 is unrolled in the form of a roll and has a throttle die. Is used to extrude the hard coat layer coating solution 1 directly onto the surface of the support opposite to the surface of the protective film for polarizing plate on the backup roll on which the easy adhesion layer 1 / coating layer / easy adhesion layer 2 is coated. And applied. After coating at a transfer speed of 30 m / min, drying at 30 ° C. for 15 seconds and 90 ° C. for 20 seconds, and further using a 160 W / cm air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) under a nitrogen purge. The coating layer is cured by irradiating with an ultraviolet ray with an irradiation amount of 90 mJ / cm ² to form a hard coat layer having an antiglare property with a thickness of 6.0 μm, and a protective film for polarizing plate of winding Example 1 is produced. did.

(Measurement of physical properties of protective film for polarizing plate)
Hereinafter, each physical property of the protective film for polarizing plate according to the present invention was measured.

[Moisture permeability 1]
The measurement method of moisture permeability is "Polymer Physical Properties II" (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285-294: Measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) The film sample of 70 mmφ according to the present invention was conditioned at 60 ° C. and 95% RH for 24 hours, and using a moisture permeable cup according to JIS Z-0208, moisture permeability = The amount of water per unit area (g / m ² ) was calculated as mass after humidity control-mass before humidity control. The moisture permeability value was not corrected for a blank cup without a hygroscopic agent.

[Moisture permeability 2]
In the present invention, the moisture permeability was calculated according to JIS Z-0208 except that the humidity control condition was changed to 60 ° C. and 95% RH. At this time, the operation of taking out and weighing the cup placed in the thermo-hygrostat at an appropriate time interval is repeated, and the mass increase per unit time is obtained for each of two consecutive weighings, and it is constant within 5%. Evaluation continued until.
Moreover, in order to exclude the influence by the moisture absorption etc. of a sample, the blank cup which does not put a hygroscopic agent was measured, and the value of moisture permeability was correct | amended.

[Moisture permeability 3]
In the present invention, the moisture permeability was measured with a PERMARTRAN-W3 / 33 type moisture permeability measuring device manufactured by Mocon under the conditions of 40 ° C. and a relative humidity of 90% RH.

〔hardness〕
<Pencil hardness>
The strength of the film of the present invention was evaluated by a pencil hardness test according to JIS-K5400.

[Measurement of layer thickness of coating layer and mixed region]
The cross section of the protective film for polarizing plate is cut using a microtome, observed from the cross section using a scanning electron microscope (S-570, manufactured by Hitachi, Ltd.) in a reflection electron mode, and a coating layer and mixed from the photographed photograph The layer thickness of the region was determined.
Further, in order to confirm the film thickness distribution of the coating layer, the film thickness was determined at intervals of 20 cm in both the width direction and the longitudinal direction, and the variation with respect to the average film thickness was determined.

[Adhesion]
The adhesion between the film layers or between the support and the coating layer was evaluated by the following method.
On the surface of the coating layer side (the coating layer side or the hard coat layer side), cut a total of 100 square squares by making 11 vertical and 11 horizontal cuts in a grid pattern with a cutter knife at 1 mm intervals, A polyester pressure-sensitive adhesive tape (NO. 31B) manufactured by Nitto Denko Corporation is pressure-bonded, and the test for peeling after leaving for 24 hours is repeated three times at the same place, and the presence or absence of peeling is visually observed.

[Evaluation criteria]
○: no peeling △: some peeling, but no problem in practical use ×: peeling on the entire surface

[Steel wool scratch resistance evaluation]
A rubbing tester was used to rub and test under the following conditions.

[Evaluation environmental conditions]
25 ° C, 60% RH
Rubbing material: Steel wool (No. 0000, manufactured by Nippon Steel Wool Co., Ltd.) was wound around the rubbing tip (1 cm × 1 cm) of a tester in contact with the sample, and the band was fixed so as not to move. Then, the reciprocating rubbing motion under the following conditions was given.
Moving distance (one way): 13 cm, rubbing speed: 13 cm / second,
Load: 500 g / cm ² , tip contact area: 1 cm × 1 cm,
Number of rubs: 10 round trips.
An oil-based black ink was applied to the back side of the rubbed sample and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following criteria.

[Evaluation criteria]
○: At first glance no scratches are visible.
Δ: Scratches are visible when viewed closely ×: Clear scratches are visible

[Haze]
The total haze, internal haze, and surface haze of the obtained film were measured by the following measurements.
1. The total haze value of the film obtained according to JIS-K7136 is measured.
2. A few drops of silicone oil were added to the front and back surfaces of the obtained film on the low refractive index layer side, and sandwiched from the front and back using two 1 mm thick glass plates (micro slide glass product number S 9111, manufactured by MATSANAMI), Two glass plates and the obtained film were optically adhered to each other, and the haze was measured in a state where surface haze was removed, and measurement was performed by sandwiching only silicone oil between two separately measured glass plates. The value obtained by subtracting haze was calculated as the internal haze of the film.
3. The value obtained by subtracting the internal haze calculated in 2 above from the total haze measured in 1 above was calculated as the surface haze of the film.

[Integral reflectance]
The back side of the film was roughened with sandpaper, then treated with black ink, and the back side was removed, and the surface side was 380 to 780 nm using a spectrophotometer (manufactured by JASCO Corporation). In the region, the integrated spectral reflectance at an incident angle of 5 ° was measured. The arithmetic average value of the integrated reflectance of 450 to 650 nm was used for the result.

[Specular reflectivity]
The back side of the film was roughened with sandpaper, then treated with black ink, and the back side was removed, and the surface side was 380 to 780 nm using a spectrophotometer (manufactured by JASCO Corporation). In the region, the specular spectral reflectance at an incident angle of 5 ° was measured. The arithmetic average value of the specular reflectance of 450-650 nm was used for the result.

[Dustproof]
The polarizing plate-processed sample was attached to a glass plate, and the manner of dust on the surface after standing for 1 hour in a general room was visually confirmed.

[Evaluation criteria]
○: Dust is hardly attached △: Dust is a little worrisome x: Dust is worrisome

[Light resistance]
In the present invention, as a light resistance test, a light resistance test apparatus (super xenon weather meter SX120 type (long life xenon lamp), manufactured by Suga Test Instruments Co., Ltd.) is used, and irradiance is 100 ± 25 W / m ² (wavelength Before and after the light resistance test 25 hr was performed according to JIS K 5600-7-5 under the conditions of 310 nm to 400 nm), test chamber temperature 35 ± 5 ° C., black panel temperature 50 ± 5 ° C., relative humidity 65 ± 15%. In addition, ΔE * ab was determined according to the above equation (1) using the L * value, a * value, and b * value calculated from the values measured using the spectrophotometer described above.

[Crack resistance]
The radius of curvature at which cracks occur when the coating layer coating side is rounded out is determined.

(Preparation of polarizing plate)
(Production of polarizer)
A 120 μm-thick polyvinyl alcohol film was immersed in an aqueous solution containing 1 part by mass of iodine, 2 parts by mass of potassium iodide, and 4 parts by mass of boric acid, and stretched 4 times at 50 ° C. to produce a polarizer.

(Other protective films for polarizing plates)
In addition, a WV film coated with an optically anisotropic layer (manufactured by FUJIFILM Corporation) was immersed in an aqueous 1.5 mol / L sodium hydroxide solution at 55 ° C. for 120 seconds, and then washed with water and dried.

  The polarizer is applied to the surface of the protective film 1 for polarizing plate 1 to which the easy adhesion layer 1 / coating layer / easy adhesion layer 2 is applied and the surface to which the optically anisotropic layer of the saponified WV film is not applied. A fully saponified polyvinyl alcohol 5% aqueous solution was bonded as an adhesive to produce a polarizing plate 1.

[Degree of polarization]
The polarizing plate obtained as described above was allowed to stand for 1,000 hours in an environment of 60 ° C. and 95% RH, and then the degree of polarization was measured. The degree of polarization is obtained from the following formula (5). (Wavelength 550nm)

[Evaluation criteria]
○: No problem with polarization degree of 99% or more.
Δ: The degree of polarization is 98% or more and less than 99%, and there is no practical problem.
X: The degree of polarization is less than 98%, which is a problem.

[Coloring]
The protective film for polarizing plates was visually observed to determine the degree of coloring (yellowing).

[Evaluation criteria]
○: Level with almost no coloring.
Δ: Level that is very lightly colored but has no problem in practice ×: Level that coloring is a problem

[Performance of LCDs]
The polarizing plate provided in the liquid crystal display device (MRT-191S, manufactured by Mitsubishi Electric Corp.) using a TN type liquid crystal cell is peeled off. Instead, the polarizing plate 1 of the present invention is placed on the outer side (air interface side), And it stuck through the adhesive so that the transmission axis of a polarizing plate might correspond with the polarizing plate stuck on the product. The liquid crystal display device was displayed in a dark room, and the following characteristics were visually evaluated.

<Evaluation of light leakage after high and low humidity treatment (peripheral unevenness evaluation)>
After the liquid crystal display device is treated at 60 ° C. for 90% for 50 hours or 70 ° C. for 10% for 50 hours and left in an environment at 25 ° C. for 60% for 2 hours, the liquid crystal display device is displayed in black and multiple light leaks from the front Visual evaluation by an observer.

[Evaluation criteria]
◎ No light leakage was observed △ There was light leakage but it was at a level that was not a problem × Light leakage was clearly observed

[Interference unevenness (rainbow unevenness)]
Polarization using the protective film for polarizing plate of the present invention instead of the polarizing plate on the viewing side provided in a liquid crystal display device (TH-15TA2, manufactured by Matsushita Electric Industrial Co., Ltd.) using a TN type liquid crystal cell The plate was affixed via an adhesive so that the coating layer was on the viewing side and the transmission axis of the polarizing plate coincided with the polarizing plate affixed to the product. The liquid crystal display device was displayed in black in a 1,000 (lux) bright room with a three-wavelength fluorescent tube installed, and the following criteria were evaluated visually from various viewing angles.

<Judgment standard for interference unevenness>
○: No interference unevenness ○ △: No interference unevenness Δ: Weak interference unevenness ×: Strong interference unevenness

(Preparation of the protective film for polarizing plates of Examples 2-15 and Comparative Examples 1-2)
Except for changing the presence / absence of each layer, the type of coating liquid, and the film thickness as shown in Table 2, the protective films for polarizing plates of Examples 2 to 15 and Comparative Examples 1 and 2 were the same as Example 1. Produced.

  The easy adhesion layers S2 and S3 were coated as shown below.

(Coating of coating liquid S2 for easy adhesion layer)
Two layers were applied to the surface to be coated by the following method.
The first layer coating liquid of the easy-adhesion layer coating liquid S2 was applied by a bar coating method while being transported at a transport speed of 105 m / min. The coating amount was 7.1 ml / m ^2, and an antistatic layer was obtained by drying at 180 ° C. for 1 minute in an air flotation drying zone.
Subsequently, the second layer coating liquid of the easy adhesion layer coating liquid S2 was applied onto the first layer of the easy adhesion layer 1 by a bar coating method while maintaining the conveyance speed of 105 m / min. The coating amount was 5.05 ml / m ^2, and an easy-adhesion layer S2 having a two-layer structure was obtained by drying at 160 ° C. for 1 minute in an air floating drying zone.

(Coating of coating liquid S3 for easy adhesion layer)
Two layers were applied to the surface to be coated by the following method.
The first layer coating solution of the easy-adhesion layer coating solution S3 was applied by a bar coating method while being transported at a transport speed of 105 m / min. The coating amount was 5.05 ml / m ^2, and the first easy-adhesion layer was obtained by drying at 180 ° C. for 1 minute in an air floating drying zone.
Subsequently, the second layer coating solution of the easy adhesion layer coating solution S3 was applied onto the first layer of the easy adhesion layer 2 by a bar coating method while maintaining the conveyance speed of 105 m / min. The coating amount was 8.7 ml / m ^2, and an easy-adhesion layer S3 having a two-layer structure was obtained by drying at 160 ° C. for 1 minute in an air floating drying zone.

  Moreover, about the protective film for polarizing plates produced in Examples 2-15 and Comparative Examples 1-2 similarly to Example 1, moisture permeability ("moisture permeability 1"), hardness (pencil hardness), adhesion Properties (coating layer side and hard coat layer side), steel wool rubbing, haze ("internal haze" and "external haze"), integral reflectance, specular reflectance, and dust resistance were measured. Table 3 shows the measurement results.

  Furthermore, it carried out similarly to Example 1, produced the polarizing plate using the protective film for polarizing plates produced in Examples 2-15 and Comparative Examples 1-2, About the produced polarizing plate, a polarization degree, Coloring and light resistance were measured. Table 3 shows the measurement results.

  In addition, the performance of the above-described liquid crystal display was evaluated for the liquid crystal display devices using the polarizing plates produced in Examples 2 to 15 and Comparative Examples 1 and 2 in the same manner as in Example 1. Table 3 shows the measurement results.

(Example 16)
<Preparation of protective film for polarizing plate>
(Coating of low refractive index layer)
The protective film for polarizing plate of Example 3 was unwound in the form of a roll, and the coating liquid 1 for the low refractive index layer was applied to the hard coating layer of the protective film for polarizing plate on the backup roll using a coater having a throttle die. The film was directly extruded onto the surface and coated to form a low refractive index layer having a thickness of 100 nm, wound up, and a protective film for polarizing plate of Example 16 was produced. The drying / curing conditions are shown below.
Drying: Dried at 90 ° C. for 60 seconds.
Curing: After curing at 110 ° C. for 10 minutes, using a 240 W / cm air-cooled metal halide lamp (manufactured by Igraphic Co., Ltd.) in an atmosphere with an oxygen concentration of 0.1% by nitrogen purge, the irradiation dose is 400 mJ / cm ² . Irradiated with ultraviolet rays.

(Preparation of the protective film for polarizing plates of Examples 17-18)
Protective films for polarizing plates of Examples 17 to 18 were produced in the same manner as in Example 10 except that the coating liquid for hard coat layer and the coating liquid for low refractive index layer were changed as shown in Table 2.

(Preparation of protective film for polarizing plate of Examples 19-22)
The coating liquid for hard-coat layer and the coating liquid for low refractive index layers were changed as shown in Table 2, and the protective film for polarizing plates of Examples 19-22 was produced from the coating liquid for low refractive index layers. At that time, the drying / curing conditions were changed as shown below.
Drying: Dried at 90 ° C. for 60 seconds.
Curing: Irradiation with ultraviolet rays with an irradiation amount of 400 mJ / cm ² was performed using a 240 W / cm air-cooled metal halide lamp (manufactured by Eyegraphic Co., Ltd.) in an atmosphere with an oxygen concentration of 0.1% by nitrogen purge.

(Example 23)
<Preparation of protective film for polarizing plate>
After producing a film with a hard coat layer by the same method as in Example 3 above, corona discharge treatment was performed under the conditions of 2.0 kW and a line speed of 12 m / min. Using a coater having a throttle die on the corona-treated film with a hard coat layer, the coating liquid 6 for the low refractive index layer is directly extruded onto the surface on which the hard coat layer on the backup roll is applied, The low refractive index layer having a thickness of 100 nm was wound up and cured at 120 ° C. for 3 minutes. Thereafter, ultraviolet rays having an irradiation amount of 400 mJ / cm ² were irradiated by nitrogen purge using an air-cooled metal halide lamp (manufactured by Eye Graphic Co., Ltd.) having an oxygen concentration of 0.1% at 240 W / cm. Thus, the protective film for polarizing plates of Example 23 was produced.

(Example 24)
<Preparation of protective film for polarizing plate>
After producing a film with a hard coat layer by the same method as in Example 3, the hard coat layer coating solution 4 was applied using a coater having a throttle die. After coating at a transfer speed of 30 m / min, drying at 30 ° C. for 15 seconds and 90 ° C. for 20 seconds, and further using a 160 W / cm air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) under a nitrogen purge. The coating layer was cured by irradiating with an ultraviolet ray having an irradiation amount of 200 mJ / cm ² . At this time, the film thickness after curing of the coating liquid 4 for hard coat layer was 1.5 μm. Thus, the protective film for polarizing plates of Example 24 was produced.

(Preparation of the protective film for polarizing plates of Examples 25-30)
Protective films for polarizing plates of Examples 25 to 30 were produced in the same manner as in Example 2 except that the coating liquid for hard coat layer and the coating liquid for low refractive index layer were changed as shown in Table 2.
In Example 30, after forming the first coating layer, the second coating layer was coated and laminated in the same manner, and the other layers were formed by the same method as in Example 2.

The evaluation results of the obtained protective film for polarizing plate, polarizing plate and liquid crystal display are summarized in Table 3. The polarizing plate of the present invention has no problem of degree of polarization and coloring, can suppress peripheral unevenness, and exhibits practically preferable performance. In addition, it exhibited favorable performance for use on the surface of a liquid crystal display device, which has good scratch resistance and dust resistance, and can reduce reflection due to low reflectance and surface scattering. Although Example 9 was inferior in scratch resistance, the other performances were good, and the performance was sufficient for use inside the liquid crystal display device (the back side of the liquid crystal cell as viewed from the viewer side).
Moreover, the film thickness distribution of the coating layer of each protective film for polarizing plates was good, with all being ± 15% or less.

  In Examples 25 to 26, the surface area of the coating was poor and the curl was large.

  In all of the protective films for polarizing plates of Examples 5, 6, and 16 to 24, the transmittance of light with a wavelength of 380 nm was 5% or less, and the transmittance with a wavelength of 600 nm was 80% or more.

For Examples 4 and 5, Example 4 and Example 5 were performed except that the surface of the coating layer was subjected to a corona discharge treatment under the condition of 727 J / m ² in the state of being conveyed at a conveyance speed of 105 m / min before being bonded to the polarizer. As a result of producing and evaluating a protective film for a polarizing plate, a polarizing plate, and a liquid crystal display device under the same conditions as in Example 5, adhesion to the polarizer was improved without affecting other performance.

  Table 4 shows the results of evaluating the moisture permeability of the polarizing plate protective films of the above Examples and Comparative Examples by changing the measurement method. In any measurement method, it can be seen that the protective film for polarizing plate of the present invention exhibits low moisture permeability.

(Examples 15-2 to 15-10)
Implemented in the same manner as in Example 15 except that the drying conditions after coating of the coating layer used in Example 15 were performed in a combination of drying temperature, drying time and coating layer thickness as shown in Table 5. When the protective films for polarizing plates, polarizing plates, and liquid crystal display devices of Examples 15-2 to 15-10 were prepared and evaluated, the moisture permeability was as shown in Table 5, and the other performances were almost the same as those of Example 15. Evaluation results were obtained. However, Example 15, Example 15-2 to Example 15-8 are superior in moisture permeability to Example 15-9, and are more resistant to cracking of protective film products for polarizing plates than Example 15-10. The result was excellent.

(Other examples)
Polarization is performed in the same manner as in Example 2 except that 5% by mass of the above UV-1 (ultraviolet absorber 1) is added to the chlorine-containing polymer in the coating layer coating solution used in Example 2 above. As a result of producing and evaluating a protective film for a plate, a polarizing plate, and a liquid crystal display device, ΔE * ab was 3.0 or less and light resistance was further improved without affecting other performance.

  Further, in Example 2, except that 5% by mass of a benzophenone-based compound UV-11 (Adeka Stub LA-51, manufactured by Asahi Denka Co.) represented by the following structural formula was added to the chlorine-containing polymer in the coating solution. As a result of producing and evaluating a protective film for a polarizing plate, a polarizing plate, and a liquid crystal display device by the same method as in Example 2, ΔE * ab was 3.0 or less without affecting other performance, and light resistance was improved. Further improved.

  Further, in Example 2, the same method as in Example 2 except that 5% by mass of UV-12 (ultraviolet absorbing polymer) represented by the following structural formula was added to the chlorine-containing polymer in the coating layer coating solution. As a result of producing and evaluating a protective film for a polarizing plate, a polarizing plate, and a liquid crystal display device, ΔE * ab was 3.0 or less and light resistance was further improved without affecting other performances.

  Example 2 except that 5 mass% of hydroxamic acid (the following structural formula H-1) was added to the chlorine-containing copolymer as an antioxidant in the coating layer coating solution used in Example 2 above. As a result of producing and evaluating a protective film for a polarizing plate, a polarizing plate, and a liquid crystal display device by the same method as described above, ΔE * ab was 3.0 or less and light resistance was further improved without affecting other performance.

  Same as Example 2 except that 5% by mass of a metal complex (the following structural formula M) is added to the chlorine-containing copolymer as an antioxidant in the coating layer coating solution used in Example 2 above. As a result of producing and evaluating a protective film for polarizing plate, a polarizing plate, and a liquid crystal display device by the method, ΔE * ab was 3.0 or less and light resistance was further improved without affecting other performance.

Structural formula (M)

  Same as Example 2 except that 1% by mass of dibutyltin dilauryl mercaptoide is added to the chlorine-containing copolymer as a metal stabilizer in the coating layer coating solution used in Example 2 above. As a result of producing and evaluating a protective film for polarizing plate, a polarizing plate, and a liquid crystal display device by the method, ΔE * ab was 3.0 or less and light resistance was further improved without affecting other performance.

As a result of producing and evaluating the protective film for polarizing plates of Examples 27 to 30, the polarizing plate using the protective film for polarizing plates, and the liquid crystal display device in the same manner as in Example 2, ΔE * ab was 3 The light resistance was good at 0.0 or less. Further, the blocking resistance was remarkably improved, and the rolled form in the roll form was also good.
Furthermore, for Examples 27 to 30, the transparent base film was replaced with the normal 1,340 mm wide TAC (TD80U manufactured by FUJIFILM Corporation), except that TAC having a width of 1,600 mm was used. As a result of producing and evaluating in the same manner as in No. 2, a polarizing plate corresponding to a large panel of 42 inches or more was obtained with high productivity while obtaining the same performance.
For Examples 28 and 30, using a coating machine having two coating stations, the hard coat layer and the low refractive index layer or the first coating layer and the second coating layer were continuously applied. When produced, the same performance was obtained, the cost was reduced, and a polarizing plate protective film with very high production efficiency could be obtained.

(Polarizing plate T)
A polarizing plate T was produced in the same manner as in Example 1 except that the WV film was changed to a normal TAC (TD80 manufactured by FUJIFILM Corporation).

(Polarizing plate Z)
A polarizing plate Z was produced in the same manner as in Example 1 except that the WV film was low retardation TAC (Z-TAC, manufactured by FUJIFILM Corporation, Re = 1 nm, Rth = -3 nm).

[Performance of LCDs]
Further, the polarizing plate provided in the VA liquid crystal display device (LC-26GD3, manufactured by Sharp) is peeled off while leaving the retardation film, and the polarizing plate T of the present invention is attached to the product instead of the polarizing plate T of the present invention. Affixed to match the polarizing plate.
Polarized light in which the polarizing plate provided in the IPS liquid crystal display device (Th-26LX300, manufactured by Matsushita Electric Industrial Co., Ltd.) is peeled off and the polarizing plate Z of the present invention is attached to the product instead of the polarizing plate Z of the present invention. Affixed to match the board.
Further, the polarizing plate provided in the IPS liquid crystal display device (32LC100, manufactured by Toshiba Corporation) is left on the front side retardation film, the back side retardation film is peeled off, and the polarizing plate Z of the present invention is polarized instead. It stuck so that the transmission axis of a board might correspond with the polarizing plate stuck on the product. All were pasted so that the side on which the coating layer was applied was on the outside. Moreover, it was confirmed that any liquid crystal display device can significantly reduce the peripheral unevenness by using the polarizing plate of the present invention. Further, the scratch resistance and reflectivity were sufficient for use on the surface of a liquid crystal display device.
Moreover, about the apparatus of Examples 1-24, the liquid crystal display device which changed only the polarizing plate of the backlight side into the polarizing plate T, and also put the brightness improvement film (product made from DBEF, 3M) in the backlight side is produced, The brightness of the display has been improved without deteriorating the surrounding unevenness and other performance. Furthermore, in the apparatus using the brightness enhancement film, it was recognized that the change in the color of the viewing angle was small in the apparatus using Z-TAC with extremely small retardation for the protective film for polarizing plate in contact with the brightness enhancement film.
In addition, it was found that in a liquid crystal display device in which a brightness enhancement film was placed and a film having a brightness enhancement film adhered to a polarizing plate with an adhesive, peripheral unevenness did not occur even under more severe conditions.

  Protective film for polarizing plate and polarizing plate in the same manner as in the above example, except that a cellulose acylate film prepared as described below was used instead of TD80-UL used in the above example as a transparent substrate film As a result of producing and evaluating the liquid crystal display device, the durability of the polarizing plate was further improved without affecting other performance.

(Preparation of cellulose acylate solution)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution A.

[Composition of cellulose acylate solution A]
Cellulose triacetate (acetyl substitution degree 2.86) 100.0 parts by mass Triphenyl phosphate (plasticizer 1) 6.0 parts by mass Biphenyl phosphate (plasticizer 2) 3.0 parts by mass Methylene chloride (first solvent) 402 .0 parts by mass
Methanol (second solvent) 60.0 parts by mass

(Preparation of matting agent solution)
The following composition was put into a disperser and stirred to dissolve each component to prepare a matting agent solution A.

[Matting agent solution A composition]
Silica particles having an average particle size of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd. 2.2 parts by mass Cellulose triacetate (acetyl substitution degree 2.88) 2.0 parts by mass Triphenyl phosphate (plasticizer 1) 0.2 parts by mass Parts Biphenyl phosphate (plasticizer 2) 0.1 parts by weight Methylene chloride (first solvent) 83.5 parts by weight Methanol (second solvent) 12.0 parts by weight

(Preparation of UV absorber solution)
The following composition was put into a mixing tank, stirred while heating to dissolve each component, and an ultraviolet absorbent solution A was prepared.

[UV absorber solution A composition]
UV-1 (UV absorber 1) 3.0 parts by weight UV-10 (UV absorber 2) 12.0 parts by weight Cellulose triacetate (acetyl substitution degree 2.86) 4.4 parts by weight Triphenyl phosphate (plasticizer) 1) 0.4 parts by mass Biphenyl phosphate (plasticizer 2) 0.2 parts by mass Methylene chloride (first solvent) 70.0 parts by mass
Methanol (second solvent) 10.0 parts by mass

(Preparation of cellulose acylate film 1)
97.4 parts by mass of cellulose acylate solution A, 1.3 parts by mass of matting agent solution A and 1.3 parts by mass of ultraviolet absorber solution A were mixed after filtration, and cast using a band casting machine. When the residual solvent was 60%, the film was peeled off from the band, and the film was held at 100 ° C. using a clip tenter and held at 130 ° C. for 30 seconds with the width after 5% stretching. Thereafter, the clip was removed and dried at 130 ° C. for 40 minutes (drying (1)) to produce a cellulose acylate film. The resulting cellulose acylate film had a residual solvent amount of 0.2% and a film thickness of 80 μm.

  In each Example using the protective film for polarizing plates of the present invention, light leakage did not occur, coloring was practically satisfactory, and preferable performance was exhibited. In addition, it exhibited favorable performance for use on the surface of a liquid crystal display device, which has good scratch resistance and dust resistance, and can reduce reflection due to low reflectance and surface scattering.

It is sectional drawing which shows typically one preferable embodiment of the protective film for polarizing plates of this invention. It is sectional drawing which shows typically one preferable embodiment of the polarizing plate of this invention. It is sectional drawing which shows typically one preferable embodiment of the liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Protective film for polarizing plates 2 Transparent base film 3 Covering layer 4 Layer having hard coat properties 5 Polarizing plate 6 Polarizer 7 Protective film for polarizing plate on the opposite side 8 Liquid crystal display device 9 Liquid crystal cell

Claims (20)

A coating layer having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer is formed on one surface of a transparent substrate film made of cellulose acylates, and at least a hard coat is formed on the opposite surface of the transparent substrate film The protective film for polarizing plates which provides the layer which has property, and is 60 g and the moisture permeability in 95% relative humidity is 300 g / m < ² > * day or less.   The protective film for polarizing plates according to claim 1, wherein the layer having hard coat properties has scattering properties.   The protective film for polarizing plates according to claim 1 or 2, wherein the chlorine-containing vinyl monomer is vinylidene chloride.   The thickness of a coating layer is 1 micrometer or more and 10 micrometers or less, The protective film for polarizing plates of Claim 1 to 3 characterized by the above-mentioned.   The protective film for a polarizing plate according to any one of claims 1 to 4, wherein the transparent substrate film has a thickness of 30 µm to 120 µm.   The protective film for a polarizing plate according to claim 1, wherein the cellulose acylates are cellulose acetate, cellulose acetate propionate, or cellulose acetate butyrate.   The protective film for polarizing plates according to any one of claims 1 to 6, further comprising an easy-adhesion layer between the transparent substrate film and the coating layer and on the surface of the coating layer.   At least one of the transparent substrate film, the easy adhesion layer between the transparent substrate film and the coating layer, and the coating layer contains an ultraviolet absorber, the light transmittance at a wavelength of 380 nm is 5% or less, and the wavelength is 600 nm. The transmittance | permeability is 80% or more and 100% or less, The protective film for polarizing plates in any one of Claims 1-7 characterized by the above-mentioned.   The protective film for a polarizing plate according to claim 8, wherein the ultraviolet absorber is any one of a benzotriazole compound, a benzophenone compound, and an ultraviolet absorbing polymer. The protective film for a polarizing plate according to claim 9, wherein the ultraviolet absorber contains at least one ultraviolet absorber represented by the following general formula (1).

(Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a hydrogen atom or a monovalent organic group, and at least one of R ¹ , R ² and R ³ has a total carbon number of 4 Represents an unsubstituted branched or straight chain alkyl group of ˜20, and R ¹ , R ² and R ³ are different from each other.   The protective film for polarizing plates according to any one of claims 1 to 10, wherein the coating layer contains at least one particle having a particle size of 0.5 to 12 µm.   At least one of a coating layer and an easily bonding layer contains the polymer and hydrophilic polymer compound which contain the repeating unit induced | guided | derived from a chlorine containing vinyl monomer, The any one of Claims 7-10 characterized by the above-mentioned. The protective film for polarizing plates of description.   The protective film for a polarizing plate according to any one of claims 1 to 12, wherein at least one of the surface of the transparent base film and the surface of the coating layer is treated by at least one of corona discharge treatment and glow discharge.   The coating composition used for forming the coating layer contains at least a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer and an organic solvent, and the organic solvent swells or dissolves the transparent substrate film. The protective film for polarizing plates in any one of Claims 1-13 containing the possible solvent.   A second coating layer having a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer is further formed on the coating layer according to claim 14, and the second coating layer is formed. A protective film for a polarizing plate, wherein the coating composition used is an aqueous dispersion of the polymer.   The protective film for polarizing plates according to any one of claims 1 to 15, wherein the coating layer contains at least one of an antioxidant and a metal complex.   A coating layer coating composition containing a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer and a solvent capable of dissolving or dispersing the polymer is applied on a transparent substrate film and dried. The method for producing a protective film for a polarizing plate according to claim 1, wherein the coating layer is formed.   In the step of forming the coating layer by applying and drying the coating layer coating solution, a second coating layer or a layer having hard coat properties is applied on the coating layer and dried to form the coating layer once. The method for producing a protective film for a polarizing plate according to claim 17, wherein each layer is continuously formed in a process from feeding to winding.   It has a polarizing film, the protective film for polarizing plates in any one of Claims 1-16, or the protective film for polarizing plates created with the manufacturing method in any one of Claim 17 or 18, and has a transparent base material. A polarizing plate, wherein a polarizing film is located on the opposite side of a layer having a hard coat property with respect to a film.   A liquid crystal display device using the polarizing plate according to claim 19.

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