JP2005148681A - Antireflection film, polarizing plate and picture display device using the antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide antireflection film whose reflectance is low, which has few luminescent point defects and also which is manufactured at low cost with good productivity. <P>SOLUTION: In the antireflection film having a light diffusing layer and a low refractive index layer on a transparent supporting body, the light diffusing layer is constituted by dispersing light transmissive particles in a matrix composed of light transmissive resin, and the difference of a refractive index between the matrix and the light transmissive particles is 0.02 to 0.2, the refractive index of the low refractive index layer is 1.20 to 1.55, and the number of the luminescent point defects of ≥50μm is ≤20/m<SP>2</SP>. Desirably, an antistatic layer is provided, and the light diffusing layer and the low refractive index layer are formed under air atmosphere whose cleanliness is equal to or above a class 10 based on regulation on air cleanness in Federal Regulation 209E. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an antireflection film, a polarizing plate using the antireflection film, and an image display device.

In general, antireflection films are used for display devices such as cathode ray tube display (CRT), plasma display (PDP), electroluminescence display (ELD), and liquid crystal display (LCD). In order to prevent reflection of light, it is arranged on the outermost surface of the display so as to reduce the reflectance by using the principle of optical interference.
Conventionally, a multilayer film obtained by laminating a plurality of metal oxide transparent thin films in order to prevent reflection of light of various wavelengths is usually used as the antireflection film. The transparent thin film of metal oxide is formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, particularly a vacuum vapor deposition method which is a kind of physical vapor deposition method. This metal oxide transparent thin film has excellent optical performance as an antireflection film, but the formation method by vapor deposition is low in productivity and is not suitable for mass production. There has been proposed a method of forming an antireflection film by coating (see, for example, Patent Documents 1 to 7).

However, in an antireflection film composed of a multilayer film in which, for example, a high refractive index layer and a low refractive index layer are laminated, when foreign matter such as dust or dust is present on the substrate or the coating film, When the film thickness is disturbed, the color and reflectance are greatly changed, and it is a problem that the portion becomes conspicuous as a bright spot defect of the coating film. In particular, in the coating method in which the film is formed by coating as compared with the vapor deposition method, the coating liquid has fluidity, and therefore, in the portion where the foreign material exists, the repelling or the like occurs due to the liquid to the foreign material portion, and the film thickness is disturbed. A part becomes large and the bright spot defect of a coating film becomes large with respect to the foreign material used as a nucleus, and it becomes conspicuous. When the number of bright spot defects is large, the yield at the time of manufacture is lowered, and in particular in recent years when the screen has been enlarged, it has been a big problem. Furthermore, when the screen is displayed in black, it is preferred that the color is not close to gray, but it is a problem because even a slight defect in the bright spot is noticeable near gray.
It is conceivable to remove dust from the manufacturing equipment as a method for preventing foreign matter that causes such bright spot defects from being mixed into the coating layer, but this requires a large and expensive equipment, which is costly. There was a problem.
Japanese Patent Publication No. 60-59250 JP 59-50401 A JP-A-2-245702 Japanese Patent Laid-Open No. 5-13021 JP 7-48527 A JP-A-8-110401 JP-A-8-179123

An object of the present invention is to provide an antireflection film that has a low reflectance, has a small number of bright spot defects, and can be manufactured with high productivity and low cost. Another object of the present invention is to provide a polarizing plate using the antireflection film.
A further object of the present invention is to provide an image display device with few bright spot defects and little reflection.

As a result of intensive studies, the present inventors have found that the above object can be achieved by an antireflection film, a polarizing plate and an image display device having the following constitution.
(1) An antireflection film having at least a light diffusion layer and a low refractive index layer on a transparent support, wherein the light diffusion layer is at least one kind of transparent material in a matrix made of at least a light-transmitting resin. The optical particles are dispersed, the refractive index difference between the matrix and the translucent particles is 0.02 to 0.2, and the refractive index of the low refractive index layer is 1.20 to 1.50. An antireflection film, wherein the number of bright spot defects having a size of 50 μm or more is 20 / m ² or less.
(2) The antireflection film as described in (1) above, which has at least one antistatic layer on a transparent support.
(3) The CIE1976L ^* a ^* b ^* color space a ^* and b ^* values of specularly reflected light with respect to the incident light of 5 degrees of the CIE standard light source D65 in the wavelength range of 380 nm to 780 nm are −7 ≦ a ^* ≦ 7, respectively. -10 <= b ^* <= 10, The antireflection film as described in said (1) or (2) characterized by the above-mentioned.
(4) The antistatic layer contains at least one selected from an ionic polymer compound and conductive inorganic fine particles as a conductive material, according to any one of (1) to (3) above Antireflection film.
(5) The antireflection film as described in any one of (1) to (4) above, wherein the ionic polymer compound is a quaternary ammonium cationic polymer having molecular crosslinking.
(6) Any of the above (1) to (5), wherein the ionic polymer compound is a polymer having a unit having a structure represented by the following general formulas (1), (1a) and (1b) An antireflection film according to claim 1.

In the general formula (1), R ₁ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom, or —CH ₂ COO ⁻ M ⁺ . Y represents a hydrogen atom or —COO ⁻ M ⁺ . L represents -CONH-, -COO-, -CO- or -O-. J represents an alkylene group having 1 to 12 carbon atoms or an arylene group. Q represents a group selected from the following group A.

M ⁺ represents a proton or a cation. R ₂ , R ₂ ′ and R ₂ ″ each independently represents an alkyl group having 1 to 4 carbon atoms. X ⁻ represents an anion. P and q each independently represent 0 or 1.

In the general formulas (1a) and (1b), R ₃ , R ₄ , R ₅ and R ₆ represent a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ₃ and R ₄ , R ₅ and R _6. May be bonded to each other to form a nitrogen-containing heterocycle. A, B and D are each independently a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, an arylene group, an alkenylene group, an arylene alkylene group, —R ₇ COR ₈ —, —R ₉ COOR ₁₀ OCOR ₁₁ —, — _{R 12 OCR 13 COOR 14 -,} - R 15 - (oR 16) m -, - R 17 CONHR 18 NHCOR 19 -, - R 20 OCONHR 21 NHCOR 22 - or -R ₂₃ NHCONHR ₂₄ NHCONHR ₂₅ - represents a. _{R 7, R 8, R 9} , R 11, R 12, R 14, R 15, R 16, R 17, R 19, R 20, R 22, R 23 and R ₂₅ represents an alkylene group. R ₁₀ , R ₁₃ , R ₁₈ , R ₂₁ and R ₂₄ each represent a linking group selected from a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylene alkylene group and alkylene arylene group. m represents a positive integer of 1 to 4. X- represents an anion. E represents a single bond, —NHCOR ₂₆ CONH— or a group selected from the above D. R ₂₆ represents a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylene alkylene group or alkylene arylene group. Z ₁ and Z ₂ represent a nonmetallic atom group necessary for forming a 5-membered or 6-membered ring together with the —N═C— group, and are represented by E in the form of a quaternary salt of ≡N ⁺ [X ⁻ ] —. You may connect. n represents an integer of 5 to 300.

(7) The low refractive index layer is formed from a composition containing a hydrolyzate of the organosilane compound (A) represented by the following general formula (2) and / or a partial condensate thereof: The antireflection film according to any one of (1) to (6).

General formula (2) (R) _m1 Si (X) _m2

In general formula (2), X represents —OH, a halogen atom, —OR ₃₀ or —OCOR ₃₀ . R and R ₃₀ each represent an alkyl group having 1 to 10 carbon atoms. m1 and m2 each represent an integer and satisfy m1 + m2 = 4.

(8) The composition containing the hydrolyzate of the organosilane compound (A) and / or a partial condensate thereof comprises the following hydrolyzate of organosilanes (B) and (C) and / or a partial condensate thereof: The composition contains a hydrolyzate of organosilane (C) and / or a partial condensate thereof in an amount of 2 to 150% by weight based on that of organosilane (B), and contains organosilane (B) and (C). At least one has a fluorine atom in R < ₃₁ > in general formula, The antireflection film as described in said (7) characterized by the above-mentioned.
(B) General formula (2b): R ₃₁ Si (X ₁ ) ₃ (wherein R ₃₁ is an organic group having 1 to 10 carbon atoms, and X ₁ has the same contents as X in the general formula (2)). Organosilane represented by:
(C) Organo represented by general formula (2c): (R ₃₁ ) ₂ Si (X ₁ ) ₂ (wherein R ₃₁ and X ₁ represent the same contents as defined in (B) above). Silane.
(9) A silyl group having a silicon atom bonded to a hydrolyzable group and / or a hydroxyl group at a terminal or a side chain, wherein the composition containing the hydrolyzate of the organosilane compound (A) and / or a partial condensate thereof The antireflection film as described in (8) above, which contains a silyl group-containing vinyl polymer (D) having at least one in the polymer.

(10) The light diffusing layer and the low-refractive index layer are formed in an air atmosphere having a cleanliness of class 10 or higher based on air cleanliness regulations in US Federal Regulations 209E. The antireflection film as described.
(11) The polarizer is a polarizing plate sandwiched between two protective films, and at least one protective film is the antireflection film according to any one of (1) to (10) above. A polarizing plate.
(12) An image display device comprising the antireflection film according to any one of (1) to (10) or the polarizing plate according to (11) on an outermost surface of a display.

The antireflection film of the present invention is excellent in that it has a low reflectance, has a small number of bright spot defects, and can be produced with high productivity and low cost. Moreover, the antireflection film of the present invention can be a film having excellent antifouling properties and scratch resistance.
Furthermore, the antireflection film of the present invention can be suitably used as a protective film for a polarizing plate, thereby providing a polarizing plate having antireflection properties. In these image display apparatuses using the antireflection film and polarizing plate of the present invention, it is possible to perform image display with excellent visibility and high display quality.

The present invention will be further described below.
First, a preferred embodiment of the antireflection film of the present invention will be described with reference to the drawings.
FIG. 1A schematically shows a cross-sectional view of one embodiment of the antireflection film according to the present invention. As shown in FIG. 1A, the antireflection film of this embodiment has a layer structure having a light diffusion layer 6 and a low refractive index layer 4 in this order on a transparent support 1. The light diffusion layer 6 is formed by dispersing at least one kind of light-transmitting particles 7 in a matrix made of at least a light-transmitting resin, and the refractive index difference between the light-transmitting particles 7 of the light diffusion layer 6 and the matrix is 0. 0.02-0.2. The refractive index of the low refractive index layer 4 is in the range of 1.20 to 1.50.
In the antireflection film of the present invention, a functional layer such as a hard coat layer or an antistatic layer may be provided. As shown in FIG. 1B, for example, the functional layer 2 can be provided between the transparent support 1 and the light diffusion layer 6. The functional layer 2 may be a single layer or a plurality of layers, for example, 2 to 4 layers. The low refractive index layer 4 is coated on the outermost layer.
Hereinafter, each layer will be described. In the present specification, the description “numerical value A” to “numerical value B” represents the meaning of “numerical value A to numerical value B”.

[Light diffusion layer]
The light diffusion layer is formed by dispersing translucent particles in a matrix made of at least translucent resin. The translucent resin mainly functions as a binder and imparts hard coat properties to the layer. The matrix may have an inorganic filler for increasing the refractive index of the layer, preventing crosslinking shrinkage, and increasing the strength. The translucent particles are added mainly for imparting antiglare properties or reducing viewing angle dependency.

The translucent resin is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a polymer having a saturated hydrocarbon chain as a main chain. The binder polymer preferably has a crosslinked structure.
As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.
In order to make the layer have a high refractive index, the monomer structure must contain at least one atom selected from an aromatic ring, a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom. preferable.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra ( (Meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polymer Acrylate), vinylbenzene and its derivatives (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinylsulfone (eg, divinylsulfone), acrylamide (eg, , Methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like. Two or more of these monomers may be used in combination.

Polymerization of these monomers having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Therefore, in this case, the light diffusion layer is prepared by preparing a coating liquid containing, for example, a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, translucent particles, and an inorganic filler. Is coated on a transparent support or a lower layer, dried, and then cured by a polymerization reaction with ionizing radiation or heat.

As radical photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds And fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoins include benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
Various examples are described in the latest UV curing technology (P.159, issuer; Kazuhiro Takasagi, publisher; Technical Information Association, Inc., published in 1991), which is useful for the present invention.
Preferable examples of commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 907) manufactured by Nippon Ciba-Geigy Co., Ltd.
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.
In addition to the photopolymerization initiator, a photosensitizer may be used. As a specific example of the photosensitizer, n? Mention may be made of butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone.

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. Ammonium sulfate, potassium persulfate, etc., 2-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile, 2-azo-bis-cyclohexanedinitrile, etc. as diazo compounds, diazoaminobenzene, p-nitrobenzene And diazonium. The thermal radical initiator is preferably used in the range of 0.1 to 15 parts by mass, more preferably in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the polyfunctional monomer.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Accordingly, in this case, the light diffusion layer is prepared by preparing a coating liquid containing, for example, a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, translucent particles, and an inorganic filler, and using the coating liquid as a transparent support. Alternatively, after coating and drying on the lower layer, it can be formed by curing by a polymerization reaction with ionizing radiation or heat. Examples of photoacid generators that generate cations by the action of light include ionic compounds such as triarylsulfonium salts and diaryliodonium salts, and nonionic compounds such as nitrobenzyl esters of sulfonic acids. Various known photoacid generators such as the compounds described in the study group, published by Organic Materials for Imaging, Inc. (1997) can be used. Among these, a sulfonium salt or an iodonium salt is particularly preferable, and PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ^{− and the} like are preferable as a counter ion. The photoacid generator is preferably used in the range of 0.1 to 15% by mass, more preferably 1 to 10% by mass, based on the total mass of the polyfunctional epoxy compound.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
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 for introducing 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 binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

The light diffusion layer contains at least one kind of translucent particles for the purpose of imparting antiglare properties or reducing the viewing angle dependency. The average particle diameter of the translucent particles is preferably 0.5 to 5 μm, more preferably 1.0 to 4 μm. For example, inorganic compound particles or resin particles are used.
Specific examples of translucent particles include inorganic compound particles such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles. Preferably mentioned. Of these, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are preferred.
As the shape of the translucent particles, either a true sphere or an indefinite shape can be used, but a true sphere is preferable.

  In addition, the light diffusion layer may contain two or more kinds of translucent particles, preferably two or more kinds of particles having different particle diameters, and particles having a larger particle diameter give antiglare properties. However, it is possible to impart other optical characteristics with particles having a smaller particle diameter. For example, when an antireflection film is attached to a high-definition display of 133 ppi or higher, it is required that there is no problem in optical performance called glare. This glare originates from the fact that the pixels are enlarged or reduced due to unevenness existing on the film surface (contributing to anti-glare properties) and loses uniformity of brightness, but with a particle size smaller than the particles that impart anti-glare properties. By using particles different from the refractive index of the binder, it can be greatly improved.

  Furthermore, the particle size distribution of the translucent particles is preferably monodisperse, and the closer the particle size of each particle is, the better. 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 of the total number of particles, more preferably 0.1%. Or less, more preferably 0.01% or less. Matt particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and by increasing the number of classifications or increasing the degree thereof, translucent particles having a more preferable distribution can be obtained. .

It is preferable that 3-30 mass% of translucent particle | grains are contained in the total solid of a light-diffusion layer. Especially preferably, it is 10-20 mass%.
The particle size distribution of the translucent particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

In order to increase the refractive index of the layer, the light diffusing layer includes an oxidation of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony in addition to the above light-transmitting particles. It is preferable that an inorganic filler having an average particle diameter of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less is contained.
Conversely, in order to increase the refractive index difference between the translucent particles and the layer matrix, the light diffusion layer using the high refractive index translucent particles keeps the refractive index of the layer matrix low. It is also preferable to use a silicon oxide. The preferred particle size is the same as that of the aforementioned inorganic filler.
Specific examples of the inorganic filler used in the light diffusion 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 . TiO ₂ and ZrO ₂ are particularly preferable from the viewpoint of increasing the refractive index. The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.
The amount of these inorganic fillers added is preferably 10 to 90% of the total mass of the light diffusion layer, more preferably 20 to 80%, and particularly preferably 30 to 75%.
Such a filler does not scatter because the particle size is sufficiently smaller than the wavelength of light, and the matrix, which is a dispersion in which the filler is dispersed in the binder polymer, behaves as an optically uniform substance.

  The difference between the refractive index of the matrix of the light diffusion layer of the present invention (translucent resin, a mixture with an inorganic filler added if necessary) and the refractive index of the translucent particles is 0.02 to 0.2. It is preferable that the refractive index of the matrix of the light diffusion layer is 1.48 to 2.00. The refractive index difference is more preferably 0.04 to 0.15, and the refractive index of the light diffusion layer matrix is more preferably 1.50 to 1.80. In order to set the refractive index of the matrix of the light diffusion layer within the above range, the kind and amount ratio of the light-transmitting resin and the inorganic filler may be appropriately selected. How to select can be easily known experimentally in advance.

  The film thickness of the light diffusion layer is preferably 1 to 10 μm, and more preferably 1.2 to 6 μm.

Since the antireflection film of the present invention has a light diffusion layer, it is also effective for improving the viewing angle of, for example, a liquid crystal display device. The present inventors have confirmed that the intensity distribution of scattered light measured with a goniophotometer correlates with the viewing angle improvement effect. That is, the more the light emitted from the backlight is diffused by the antireflection film of the present invention installed on the viewing side surface, the better the viewing angle characteristics. However, if it is diffused too much, backscattering will increase and the front luminance will decrease, or the scattering will be too great and the image clarity will deteriorate. Therefore, it is necessary to control the scattered light intensity distribution within a certain range. Therefore, as a result of intensive studies, in order to achieve the desired visual characteristics, the scattered light intensity at 30 °, which correlates particularly with the visual angle improvement effect, is 0.01 with respect to the light intensity at the output angle 0 ° of the scattered light profile. % To 0.2% is preferable, 0.02% to 0.15% is more preferable, and 0.03% to 0.1% is particularly preferable.
The scattered light profile can be measured using the automatic goniophotometer GP-5 manufactured by Murakami Color Research Laboratory Co., Ltd. for the prepared antireflection film.

[Antistatic layer]
In the present invention, it is preferable to provide an antistatic layer from the viewpoint of preventing static electricity on the film surface and reducing the number of bright spot defects. The antistatic layer can be formed by, for example, applying a conductive coating solution containing conductive fine particles and a reactive curable resin, or depositing or sputtering a metal or metal oxide that forms a transparent film. Conventionally known methods such as a method of forming a conductive thin film can be listed.
In the antireflection film of the present invention, the antistatic layer can be formed directly on the transparent support or via a primer layer that strengthens the adhesion to the transparent support. Further, the antistatic layer can be used as a part of the antireflection film. In this case, when used in a layer close to the outermost layer, sufficient antistatic properties can be obtained even if the film is thin.
The coating method is not particularly limited, and an optimum method is selected from known methods such as roll coating, gravure coating, bar coating, and extrusion coating according to the characteristics of the coating liquid and the coating amount. Just do it.

The thickness of the antistatic layer is preferably from 0.01 to 10 μm, more preferably from 0.03 to 7 μm, and even more preferably from 0.05 to 5 μm. The surface resistance of the antistatic layer is preferably from 10 ⁵ ~10 ¹² Ω / sq, more preferably from 10 ⁵ ~10 ⁹ Ω / sq, most be 10 ⁵ ~10 ⁸ Ω / sq preferable. The surface resistance of the antistatic layer can be measured by a four probe method.
The antistatic layer is preferably substantially transparent. Specifically, the haze of the antistatic layer is preferably 10% or less, more preferably 5% or less, further preferably 3% or less, and most preferably 1% or less. . The transmittance of light having a wavelength of 550 nm is preferably 50% or more, more preferably 60% or more, further preferably 65% or more, and most preferably 70% or more.
The antistatic layer of the present invention is preferably excellent in strength, and the specific strength of the antistatic layer is preferably not less than H with a pencil hardness of 1 kg load (as defined in JIS-K-5400). It is more preferably 2H or more, further preferably 3H or more, and most preferably 4H or more.

  In the present invention, the antistatic layer preferably contains at least one selected from conductive inorganic fine particles and ionic polymer compounds as a conductive material.

(Conductive inorganic fine particles)
The specific surface area of the conductive inorganic fine particles is preferably from 10 to 400 m ² / g, more preferably from 20 to 200 m ² / g, and more preferably 30 to 150 m ² / g.

  The conductive inorganic fine particles are preferably formed from a metal oxide or nitride. Examples of metal oxides or nitrides include tin oxide, indium oxide, zinc oxide and titanium nitride. Tin oxide and indium oxide are particularly preferred. The conductive inorganic fine particles are mainly composed of oxides or nitrides of these metals, and can further contain other elements. The main component means a component having the largest content (mass%) among the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, S, B, Nb, In, V and halogen atoms are included. In order to increase the conductivity of tin oxide and indium oxide, it is preferable to add Sb, P, B, Nb, In, V and a halogen atom. Particularly preferred are tin oxide containing Sb (ATO) and indium oxide containing Sn (ITO). The ratio of Sb in ATO is preferably 3 to 20% by mass. The ratio of Sn in ITO is preferably 5 to 20% by mass.

  The average primary particle diameter of the conductive inorganic fine particles used in the antistatic layer is preferably 1 to 150 nm, more preferably 5 to 100 nm, and most preferably 5 to 70 nm. The average particle diameter of the conductive inorganic fine particles in the formed antistatic layer is preferably 1 to 200 nm, more preferably 5 to 150 nm, still more preferably 10 to 100 nm, and more preferably 10 to 80 nm. Most preferably. The average particle diameter of the conductive inorganic fine particles is an average diameter weighted by the mass of the particles, and can be measured by a light scattering method or an electron micrograph.

The conductive inorganic fine particles may be surface-treated. The surface treatment is performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include alumina and silica. Silica treatment is particularly preferred. Examples of organic compounds used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Silane coupling agents are most preferred. Two or more kinds of surface treatments may be performed in combination.
The shape of the conductive inorganic fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape.
Two or more kinds of conductive inorganic fine particles may be used in combination in the antistatic layer.

  The proportion of the conductive inorganic fine particles in the antistatic layer is preferably 20 to 90% by mass, preferably 25 to 85% by mass, and more preferably 30 to 80% by mass.

  The conductive inorganic fine particles are used for forming an antistatic layer in the form of a dispersion. As the dispersion medium for the conductive inorganic fine particles, a liquid having a boiling point of 60 to 170 ° C. is preferably used. Examples of dispersion media include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ester (eg, methyl acetate, ethyl acetate, Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Hydrocarbon (eg, benzene, toluene, xylene), amide (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methyl) Carboxymethyl-2-propanol) are included. Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are particularly preferable.

  The conductive inorganic fine particles can be dispersed in the medium using a disperser. Examples of dispersers include sand grinder mills (eg, pinned bead mills), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

(Ionic polymer compound)
Examples of the ionic polymer compound that can be used in the antistatic layer of the present invention include quaternary ammonium cationic polymers. Among them, a quaternary ammonium cationic polymer that undergoes molecular crosslinking is preferable because it can improve the antifouling property and scratch resistance (film strength) of the film. Examples of preferable ionic polymer compounds also include polymers having units having structures represented by the following general formulas (1), (1a) and (1b).

In the general formula (1), R ₁ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom, or —CH ₂ COO ⁻ M ⁺ . Y represents a hydrogen atom or —COO ⁻ M ⁺ . L represents -CONH-, -COO-, -CO- or -O-. J represents an alkylene group having 1 to 12 carbon atoms or an arylene group. Q represents a group selected from the following group A.

M ⁺ represents a proton or a cation (for example, alkali metal and Ca are preferable, and Li, Na, and K are particularly preferable). R ₂ , R ₂ ′ and R ₂ ″ each independently represents an alkyl group having 1 to 4 carbon atoms. X ⁻ represents an anion (for example, a halogen ion, a sulfonate anion, a carboxylate anion, etc.). P and q each independently represents 0 or 1;

In the general formulas (1a) and (1b), R ₃ , R ₄ , R ₅ and R ₆ represent a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ₃ and R ₄ , R ₅ and R _6. May be bonded to each other to form a nitrogen-containing heterocycle.
A, B and D are each independently a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, an arylene group, an alkenylene group, an arylene alkylene group, —R ₇ COR ₈ —, —R ₉ COOR ₁₀ OCOR ₁₁ —, — _{R 12 OCR 13 COOR 14 -,} - R 15 - (oR 16) m -, - R 17 CONHR 18 NHCOR 19 -, - R 20 OCONHR 21 NHCOR 22 - or -R ₂₃ NHCONHR ₂₄ NHCONHR ₂₅ - represents a. _{R 7, R 8, R 9} , R 11, R 12, R 14, R 15, R 16, R 17, R 19, R 20, R 22, R 23 and R ₂₅ represents an alkylene group. R ₁₀ , R ₁₃ , R ₁₈ , R ₂₁ and R ₂₄ each represent a linking group selected from a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylene alkylene group and alkylene arylene group. m represents a positive integer of 1 to 4. X- represents an anion (for example, a halogen ion, a sulfonate anion, a carboxylate anion, etc.).

  However, when A is an alkylene group, a hydroxyalkylene group or an arylenealkylene group, it is preferable that B is not an alkylene group, a hydroxyalkylene group or an arylenealkylene group.

E represents a single bond, —NHCOR ₂₆ CONH— or a group selected from the above D. R ₂₆ represents a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylene alkylene group or alkylene arylene group.

Z ₁ and Z ₂ represent a nonmetallic atom group necessary for forming a 5-membered or 6-membered ring together with the —N═C— group, and are represented by E in the form of a quaternary salt of ≡N ⁺ [X ⁻ ] —. You may connect. n represents an integer of 5 to 300.

  Specific examples of the ionic polymer compound including the polymer having a unit having a structure represented by the general formulas (1), (1a) and (1b) are shown below, but the present invention is not limited to these. Absent. In addition, the subscripts (m, p, q (including q1, q2, q3), r, x, y, z) in the following specific examples IP-7 to 21 are molar ratios of each repeating unit in the polymer. Represents.

  Further, phosphazene compounds described in JP-A-6-248092 can also be preferably used.

In the present invention, one kind of ionic polymer compound may be used alone, or several kinds of ionic polymer compounds may be used in combination. The content of the antistatic layer of the ionic polymer compound is preferably ^{0.005~2.0g / m 2, 0.01~1.0g / m} 2 is more preferable.

[Hard coat layer]
The antireflection film of the present invention is preferably provided with a so-called smooth hard coat layer in order to impart physical strength to the film, and can be provided on the surface of the transparent support. In particular, it is preferably provided between the transparent support and the light diffusion layer.

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 applying 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.

  Specific examples of the photopolymerizable polyfunctional monomer having a photopolymerizable functional group include those exemplified in the description of the light diffusion layer, and it is preferable to perform polymerization using a photopolymerization initiator and a photosensitizer. The photopolymerization reaction is preferably performed by ultraviolet irradiation after the hard coat layer is applied and dried.

The hard coat layer preferably contains inorganic fine particles having an average primary particle size of 200 nm or less. The average particle diameter here is a mass average diameter. By setting the average particle size of the primary particles to 200 nm or less, a hard coat layer that does not impair the transparency can be formed.
The inorganic fine particles have functions of increasing the hardness of the hard coat layer and suppressing curing shrinkage of the coating layer. It is also added for the purpose of controlling the refractive index of the hard coat layer.
As inorganic fine particles, in addition to the inorganic fine particles exemplified in the high refractive index layer, silicon dioxide, aluminum oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate, titanium dioxide, zirconium oxide, tin oxide, ITO, zinc oxide, etc. Fine particles. Preferred are silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, tin oxide, ITO, and zinc oxide.

The preferable average particle diameter of the primary particles of the inorganic fine particles is 5 to 200 nm, more preferably 10 to 150 nm, still more preferably 20 to 100 nm, and particularly preferably 20 to 50 nm.
In the hard coat layer, the inorganic fine particles are preferably dispersed as finely as possible.
The particle size of the inorganic fine particles in the hard coat layer is preferably 5 to 300 nm, more preferably 10 to 200 nm, more preferably 20 to 150 nm, and particularly preferably 20 to 80 nm in terms of average particle diameter.

  The content of the inorganic fine particles in the hard coat layer is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and particularly preferably 15 to 75% by mass with respect to the total mass of the hard coat layer.

  The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably 0.2 to 10 μm, more preferably 0.5 to 7 μm, and particularly preferably 0.7 to 5 μm.

  The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400. Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better. It is also preferable that the light diffusion layer and the antistatic layer have these characteristics.

In the formation of the hard coat layer, when formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound, the crosslinking reaction or the polymerization reaction is preferably performed in an atmosphere having an oxygen concentration of 10% by volume or less. . By forming in an atmosphere having an oxygen concentration of 10% by volume or less, a hard coat layer excellent in physical strength and chemical resistance can be formed. Preferably, it is formed by a crosslinking reaction or polymerization reaction of an ionizing radiation curable compound in an atmosphere having an oxygen concentration of 6% by volume or less, more preferably an oxygen concentration of 4% by volume or less, particularly preferably an oxygen concentration of 2 Volume% or less, most preferably 1 volume% or less. It is preferable for the light diffusion layer and the antistatic layer to perform the crosslinking reaction or the polymerization reaction under the oxygen concentration as described above.
As a method of reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.
The hard coat layer is preferably constructed by applying a coating composition for forming a hard coat layer on the surface of the transparent support.

[Low refractive index layer]
The refractive index of the low refractive index layer of the antireflection film of the present invention is 1.20 to 1.50, preferably 1.30 to 1.48. The film thickness of the low refractive index layer is preferably 50 to 200 nm, more preferably 70 to 130 nm.
Further, the low refractive index layer preferably satisfies the following formula (VII) from the viewpoint of reducing the reflectance.

Formula (VII) (m / 4) × 0.7 <n ₁ d ₁ <(m / 4) × 1.3

In the formula, m is a positive odd number, n ₁ is the refractive index of the low refractive index layer, and d ₁ 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 (VII) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (VII) exists in the said wavelength range.

  The low refractive index layer of the antireflection film of the present invention comprises a composition composed of a hydrolyzate of an organosilane compound (A) represented by the following general formula (2) and / or a partial condensate thereof (hereinafter referred to as low refraction). It is also preferable that the film is formed from the composition for the rate layer, since the antifouling property and scratch resistance (film strength) of the film can be improved.

General formula (2) (R) _m1 Si (X) _m2

In general formula (2), X represents —OH, a halogen atom, —OR ₃₀ or —OCOR ₃₀ . R and R ₃₀ each represent an alkyl group having 1 to 10 carbon atoms. m1 and m2 each represent an integer and satisfy m1 + m2 = 4.

The low refractive index layer formed from the above composition is a SiO ₂ gel layer formed by a so-called sol-gel method. The lower silicon alkoxide used for forming the SiO ₂ gel layer is a compound represented by R _a Si (OR ′) _b , wherein R and R ′ each represents an alkyl group having 1 to 10 carbon atoms, a + b is 4. More specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, methyltri Methoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyldimethoxysilane, methyldiethoxy Examples thereof include silane and hexyltrimethoxysilane.

The composition for a low refractive index layer preferably contains a hydrolyzate of the following organosilanes (B) and (C) and / or a partial condensate thereof. In this case, an organosilane (C 2) to 150 mass% of the organosilane (B), and at least one of the organosilanes (B) and (C) is a fluorine atom at R ₃₁ in the general formula It is preferable to have.

(B) General formula (2b): R ₃₁ Si (X ₁ ) ₃ (wherein R ₃₁ is an organic group having 1 to 10 carbon atoms, and X ₁ has the same contents as X in the general formula (2)). Organosilane represented by:
(C) Organo represented by general formula (2c): (R ₃₁ ) ₂ Si (X ₁ ) ₂ (wherein R ₃₁ and X ₁ represent the same contents as defined in (B) above). Silane.

Furthermore, the composition for a low refractive index layer is a silyl group-containing vinyl polymer (D) having at least one silyl group having a silicon atom bonded to a hydrolyzable group and / or a hydroxyl group at a terminal or a side chain. ) Is preferably contained.
Hereinafter, the organosilanes (B) and (C) and the silyl group-containing vinyl polymer (D) will be described.

(Organosilane (B))
The organosilane (B) is preferably an organosilane represented by the general formula (2b ′): R ₃₁ Si (OR ₃₂ ) _{3. In the} composition for a low refractive index layer, it is hydrolyzed and condensed. The resulting hydrolyzate and / or partial condensate serves as a binder in the composition. R ₃₁ in the organosilane is an organic group having 1 to 10 carbon atoms, for example, an alkyl group such as methyl group, ethyl group, n-propyl group, i-propyl group, γ-chloropropyl group, vinyl group, etc. , CF ₃ CH ₂ CH ₂ CH _2- , C ₂ F ₅ CH ₂ CH ₂ CH _2- , C ₃ F ₇ CH ₂ CH ₂ CH _2- , C ₂ F ₅ CH ₂ CH _2- , CF ₃ OCH ₂ CH ₂ CH _2- , C ₂ F ₅ OCH ₂ CH ₂ CH _2- , C ₃ F ₇ OCH ₂ CH ₂ CH _2- , (CF ₃ ) ₂ CHOCH ₂ CH ₂ CH _2- , C ₄ F ₉ CH ₂ OCH ₂ CH ₂ CH _2- , 3- (perfluorocyclohexyloxy) propyl, H (CF ₂ ) ₄ CH ₂ OCH ₂ CH ₂ CH _2- , H (CF ₂ ) ₄ CH ₂ CH ₂ CH _2- , γ-glycid A xylpropyl group, γ-methacryloxypropyl group, γ-mercaptopropyl group, phenyl group, 3,4-epoxycyclohexylethyl group and the like can be mentioned. R ₃₂ in the organosilane is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl. Group, sec-butyl group, tert-butyl group, acetyl group and the like.

Specific examples of these organosilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane. I-propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl Triethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, Cycloalkenyl trimethoxysilane, phenyl triethoxysilane, 3,4-epoxy cyclohexylethyl trimethoxysilane, 3,4-epoxycyclohexyl ethyl trimethoxy _{silane, CF 3 CH 2 CH 2 CH} 2 Si (OCH 3) 3, C 2 H ₅ CH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₂ F ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₃ F ₇ CH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₂ F ₅ OCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₃ F ₇ OCH ₂ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ , (CF ₃ ) ₂ CHOCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₄ F ₉ CH ₂ OCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , H (CF ₂ ) ₄ CH ₂ OCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , 3- (perfluorocyclohexyloxy) propylsilane Etc.

Among these, organosilane having a fluorine atom is preferable. In the case of using the organosilane having no fluorine atom as R _31, it is preferable to use methyltrimethoxysilane or methyltriethoxysilane. Said organosilane may be used individually by 1 type, and can also use 2 or more types together.

(Organosilane (C))
Organosilane (C) of the general formula _{(2c ') :( R 31)} 2 Si (OR 32) 2 ( wherein, R ₃₁ and R ₃₂ are the organosilane (B) R ₃₁ as defined in the description of and A diorganosilane represented by the same formula as R ₃₂ ). However, R ₃₁ and R ₃₂ may not be the same substituent as the organosilane (B). In the composition for a low refractive index layer, it becomes a hydrolyzate and / or a partial condensate obtained by hydrolysis and condensation, and acts as a binder in the composition, and also softens the coating film and has alkali resistance. It is to improve. R ₃₁ and R ₃₂ in accordance in diorganosilane are the same as R ₃₁ and R ₃₂ of the organosilane.

Specific examples of these diorganosilanes are dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-i-propyl. dimethoxysilane, di -i- propyl diethoxy silane, diphenyl dimethoxy silane, diphenyl diethoxy _{silane, (CF 3 CH 2 CH 2} ) 2 Si (OCH 3) 2, (CF 3 CH 2 CH 2 CH 2) 2 Si ( OCH ₃ ) ₂ , (C ₃ F ₇ OCH ₂ CH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ , (H (CF ₂ ) ₆ CH ₂ OCH ₂ CH ₂ CH ₂ ] ₂ Si (OCH ₃ ) ₂ , ( C ₂ F ₅ CH ₂ CH ₂ ) ₂ Si (OCH ₃ ) _{2 and the} like can be mentioned, and an organosilane having a fluorine atom is preferred. When organosilane having no fluorine atom is used as R ₃₁ , dimethyldimethoxysilane and dimethyldiethoxysilane are preferable. Such organosilanes represented by (R ₃₁ ) ₂ Si (OR ₃₂ ) ₂ may be used alone or in combination of two or more. The ratio of the hydrolyzate and / or partial condensate of organosilane (C) in the composition for low refractive index layer is 2 to 150 mass with respect to the hydrolyzate and / or partial condensate of organosilane (B). %, Preferably 5 to 100% by mass, more preferably 10 to 60% by mass. When it exceeds 150 mass%, the adhesiveness and curability of the resulting coating film tend to be lowered.

(Silyl group-containing vinyl polymer (D))
The silyl group-containing vinyl polymer (D) has a main chain composed of a vinyl polymer, and has at least one silyl group having a silicon atom bonded to a hydrolyzable group and / or a hydroxyl group at a terminal or a side chain in one polymer molecule. One, preferably two or more are contained, and most of the silyl groups are represented by the following general formula (2d).

In general formula (2d), Z is a hydrolyzable group such as a halogen atom, an alkoxy group, an acyloxy group, a phenoxy group, an amino group and / or a hydroxyl group, R ₃₆ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or C1-C10 aralkyl group, a is an integer of 1-3.

  The silyl group-containing vinyl polymer (D) may be produced by reacting (i) a hydrosilane compound with a vinyl resin having a carbon-carbon double bond, and (b) represented by the following general formula (2d ′). You may manufacture by superposing | polymerizing the silane compound represented and various vinyl type compounds, and the manufacturing method is not limited.

In general formula (2d ′), Z, R ₃₆ and a are the same as those in general formula (2d), and R ₃₇ is an organic group having a polymerizable double bond.

  Here, examples of the hydrosilane compound used in the production method shown in (a) above include halogenated silanes such as methyldichlorosilane, trichlorosilane, and phenyldichlorosilane; methyldiethoxysilane, methyldimethoxysilane, Examples include alkoxysilanes such as phenyldimethoxysilane, trimethoxysilane, and triethoxysilane; and acyloxysilanes such as methyldiacetoxysilane, phenyldiacetoxysilane, and triacetoxysilane.

  In addition, the vinyl resin used in the production method shown in (a) is not particularly limited except that the vinyl resin containing a hydroxyl group is excluded. For example, methyl (meth) acrylate, ethyl (meth) acrylate, (Meth) acrylic acid esters such as butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate; (meth) acrylic acid, itacon Acids, carboxylic acids such as fumaric acid and acid anhydrides such as maleic anhydride; epoxy compounds such as glycidyl (meth) acrylate; amino compounds such as diethylaminoethyl (meth) acrylate and aminoethyl vinyl ether; (meth) acrylamide, N- t-Butyl (meth) acrylamide, Itako Amide compounds such as acid diamide, α-ethylacrylamide, crotonamide, fumaric acid diamide, maleic acid diamide, N-butoxymethyl (meth) acrylamide; acrylonitrile, styrene, vinyltoluene, α-methylstyrene, vinyl chloride, vinyl acetate, A vinyl compound obtained by copolymerizing a vinyl compound selected from vinyl propionate, N-vinyl pyrrolidone, and compounds represented by the following FM-1 to FM-23 with a monomer having a double bond in a side chain such as allyl methacrylate. Resins are preferred, and those using at least one fluorine-containing monomer as a copolymerization monomer are particularly preferred.

  On the other hand, the following are mentioned as a silane compound used with the manufacturing method shown by (b).

  Further, as the vinyl compound used in the production method shown in (b), it is possible to use a vinyl compound used at the time of polymerization of the vinyl resin in the production method of (a). In addition to being described in the production method of (A), vinyl compounds containing hydroxyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyvinyl ether, N-methylolacrylamide and the like are listed. You can also. Moreover, what used 1 type of fluorine-containing monomers is especially preferable.

  Preferable specific examples of the silyl group-containing vinyl polymer as described above include, for example, trialkoxysilyl group-containing acrylic polymers represented by the following general formula (2d ″).

In the general formula (2d ″), R ₃₈ and R ₄₀ are a hydrogen atom, a fluorine atom or a methyl group, R ₃₉ is a hydrogen atom, and an alkyl group having 1 to 12 carbon atoms (for example, methyl, ethyl, n-propyl, allyl, n-butyl, i-butyl, n-pentyl, n-hexyl, benzyl, (CF ₃ ) ₂ CH-, CF ₃ CH _2- , C ₇ F ₁₅ CH _2- , C ₂ F ₁₅ CH ₂ CH _2- , R ₄₁ represents an alkylene group having 1 to 4 carbon atoms such as a methylene group, an ethylene group, a propylene group, or a butylene group, and R _42. is the same as _{R 39, r / (1 +} r) = 0.01~0.4 ( molar ratio), preferably 0.02 to 0.2 (molar ratio).

  The number average molecular weight of the silyl group-containing vinyl polymer is preferably 2,000 to 100,000, more preferably 4,000 to 50,000.

  Specific examples of the silyl group-containing vinyl polymer (D) used in the present invention as described above include Kanekazemulac and the following polymers manufactured by Kaneka Chemical Co., Ltd., but are not limited thereto. Is not to be done. In the following specific examples, the numerical value in parentheses is the polymerization composition ratio (mass ratio).

PP-1: Methyl methacrylate / γ-methacryloxypropyltrimethoxysilane (90/10)
PP-2: Methyl methacrylate / γ-methacryloxypropyltrimethoxysilane (85/15)
PP-3: Methyl methacrylate / γ-methacryloxypropyltrimethoxysilane (80/20)
PP-4: Methyl methacrylate / γ-methacryloxypropyltrimethoxysilane (70/30)
PP-5: Methyl methacrylate / ethyl acrylate / γ-methacryloxypropyltrimethoxysilane (50/35/15)

PP-6: Ethyl methacrylate / γ-methacryloxypropyl trimethoxysilane (85/15)
PP-7: n-butyl methacrylate / styrene / γ-methacryloxypropyltrimethoxysilane (50/35/15)
PP-8: Methyl methacrylate / methyl acrylate / γ-acryloxypropyltrimethoxysilane (35/40/15)
PP-9: methyl methacrylate / methyl acrylate / γ-acryloxypropyltrimethoxysilane (40/40/20)
P-10: Methyl methacrylate / n-butyl acrylate / vinyl trimethoxysilane (60/30/10)

PP-11: FM-1 / γ-methacryloxypropyltrimethoxysilane (85/15)
PP-12: FM-4 / γ-methacryloxypropyltrimethoxysilane (90/10)
PP-13: FM-4 / γ-methacryloxypropyltrimethoxysilane (85/15)
PP-14: FM-4 / γ-methacryloxypropyltrimethoxysilane (70/30)
PP-15: FM-4 / FM-7 / γ-methacryloxypropyltrimethoxysilane (30/55/15)

PP-16: FM-2 / FM-4 / γ-methacryloxypropyltrimethoxysilane (30/50/20)
PP-17: FM-3 / FM-4 / γ-methacryloxypropyltrimethoxysilane (25/60/15)
PP-18: FM-4 / methyl methacrylate / γ-methacryloxypropyltrimethoxysilane (60/25/15)
PP-19: FM-7 / methyl methacrylate / γ-acryloxypropyltrimethoxysilane (40/45/15)
PP-20: FM-4 / methyl methacrylate / vinyltrimethoxysilane (65/20/15)

  The ratio of the silyl group-containing vinyl polymer (D) in the composition for forming a low refractive index layer is preferably 2 to 300% by mass, more preferably 5 to 200% by mass, and still more preferably, with respect to the organosilane (B). 10 to 100% by mass. If it is less than 2% by mass, the alkali resistance of the resulting coating film tends to decrease, while if it exceeds 300% by mass, the durability of the resulting coating film tends to deteriorate.

  The low refractive index layer of the present invention is formed of a network polymer structure mainly composed of organosilicon prepared by the above-described method. The main component (monomer) for constructing this network structure is the aforementioned organosilane (B) or organosilane (C). Preferred combinations of these organosilicon monomer compounds in the present invention are exemplified below and in the examples. The mixing ratio indicates the mass (g) of each compound used.

SP-1: 10 g of methyltrimethoxysilane, 5 g of dimethyldimethoxysilane, 2 g of 3,3,3-trifluoropropyltriethoxysilane, 2.5 g of compound (PP-2)
SP-2: methyltrimethoxysilane 12 g, dimethyldiethoxysilane 8 g, 3,3,3-trifluoropropyltriethoxysilane 2 g, compound (PP-2) 3 g
SP-3: 15 g of ethyltriethoxysilane, 5 g of dimethyldiethoxysilane, 2 g of 3,3,3-trifluorobutyltriethoxysilane, 2 g of compound (PP-2)
SP-4: 10 g of methyltrimethoxysilane, 5 g of dimethyldimethoxysilane, 2 g of 3,3,3-trifluoropropyltriethoxysilane, 1.5 g of compound (PP-2)
SP-5: methyltrimethoxysilane 10 g, dimethyldimethoxysilane 5 g, 3-perfluoroethoxypropyltrimethoxysilane 5 g, compound (PP-5) 2.5 g
SP-6: Ethyltrimethoxysilane 20 g, 3,3,3-trifluorobutyltriethoxysilane 7 g, bis (3,3,3-trifluoropropyl) diethoxysilane 5 g, compound (PP-7) 3 g
SP-7: tetraethoxysilane 2 g, methyltrimethoxysilane 10 g, dimethyldimethoxysilane 5 g, 3,3,3-trifluoropropyltriethoxysilane 2 g, compound (PP-2) 2.5 g
SP-8: 18 g of cyclohexyltrimethoxysilane, 12 g of bis (3,3,3-trifluoropropyl) triethoxysilane, 3 g of tetraethoxysilane, 5 g of compound (PP-12)
SP-9: methyltrimethoxysilane 12 g, dimethyldipropoxysilane 10 g, 3,3,3-trifluoropropyltriethoxysilane 5 g, compound (PP-8) 2.5 g
SP-10: 12 g of methyltriethoxysilane, 5 g of dimethyldimethoxysilane, 5 g of bis (3,3,3-trifluoropropyl) trimethoxysilane, 4.5 g of compound (PP-8)

  The low refractive index layer of the present invention preferably contains a fluorine-containing polymer as a low refractive index binder. The fluoropolymer is preferably a fluoropolymer that is crosslinked by heat or ionizing radiation having a coefficient of dynamic friction of 0.03 to 0.15 and a contact angle with water of 90 to 120 °. An inorganic filler for improving the film strength can also be used.

  Examples of the fluorine-containing polymer used in the low refractive index layer include hydrolysis and dehydration condensate of perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane). And a fluorine-containing copolymer having a fluorine-containing monomer unit and a structural unit for imparting crosslinking reactivity as structural components.

  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-dioxole. Etc.), partially (meth) acrylic acid or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemical), M-2020 (manufactured by Daikin), etc.), fully or partially fluorinated vinyl ethers, etc. However, perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of refractive index, solubility, transparency, availability, and the like.

  As structural units for imparting crosslinking reactivity, structural units obtained by polymerization of monomers having a self-crosslinkable functional group in advance in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether, carboxyl groups, hydroxy groups, amino groups , Obtained by polymerization of a monomer having a sulfo group or the like (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 obtained by introducing a crosslinking reactive group such as a (meth) acryloyl group into these structural units 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) And the like.

  In addition to the above-mentioned fluorine-containing monomer units and structural units for imparting crosslinking reactivity, monomers not containing fluorine atoms can be copolymerized as appropriate from the viewpoints of solubility in solvents and film transparency. There are no particular limitations on the monomer units that can be used in combination. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2) -Ethylhexyl), methacrylates (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-silane) B hexyl acrylamide), 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 above polymer.

  The fluorine-containing polymer particularly useful as a binder for the low refractive index layer of 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 a crosslinking reaction alone (a radical reactive group such as a (meth) acryloyl group, a ring-opening polymerizable group such as an epoxy group or an oxetanyl group). These cross-linking reactive group-containing polymer units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymer units of the polymer.

A preferable form of the copolymer includes the following general formula (3).
General formula (3)

In General Formula (3), L represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, and 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-**, *-(CH 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 linking site on the polymer main chain side, ** is the linking on the (meth) acryloyl group side) Represents a part). m ₃ represents 0 or 1.

X ₁ represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

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. Adhesion to a substrate, Tg of a polymer (in terms of film hardness) Can be selected from various viewpoints such as solubility in solvents, transparency, slipperiness, dustproof / antifouling properties, etc., even if it is composed of one or more vinyl monomers depending on the purpose Good.
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 mol% of each constituent component, and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65. Preferably, 35 ≦ x ≦ 55, 30 ≦ y ≦ 60, and 0 ≦ z ≦ 20, and particularly preferably 40 ≦ x ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10.

Among the copolymers represented by the general formula (3), the following general formula (4) may be mentioned as a particularly preferred form.
General formula (4)

In the general formula (4), X, x, and y have the same meaning as in the general formula (3), and the preferred range is also the same.
n ₁ represents an integer of 2 ≦ n ₁ ≦ 10, preferably 2 ≦ n ₁ ≦ 6, and particularly preferably 2 ≦ n ₁ ≦ 4.
B represents 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 (3) is applicable.
Z1 and Z2 represent respective repeating units mol%, and represent values satisfying 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65. It is preferable that 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10 respectively, and it is particularly preferable that 0 ≦ z1 ≦ 10 and 0 ≦ z2 ≦ 5.

  In the copolymer represented by the general formula (3) or (4), for example, a (meth) acryloyl group is introduced into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by a polymer reaction. Can be synthesized.

  Although the preferable example of a copolymer useful as a binder of the low refractive index layer of this invention below is shown, this invention is not limited to these.

  The copolymer is synthesized by synthesizing precursors such as a hydroxyl group-containing polymer by various polymerization methods such as solution polymerization, precipitation polymerization, suspension polymerization, precipitation polymerization, bulk polymerization, and emulsion polymerization, and then polymer reaction. This can be done by introducing a (meth) acryloyl group. The polymerization reaction can be performed by a known operation such as a batch system, a semi-continuous system, or a continuous system.

  The polymerization initiation method includes a method using a radical initiator, a method of irradiating light or radiation, and the like. These polymerization methods and polymerization initiation methods are, for example, the revised version of Tsuruta Junji “Polymer Synthesis Method” (published by Nikkan Kogyo Shimbun, 1971), Takatsu Otsu, Masato Kinoshita, “Experimental Methods for Polymer Synthesis” It is described in pp. 47-154 published in 1972.

  Among the above polymerization methods, a solution polymerization method using a radical initiator is particularly preferable. Solvents used in the solution polymerization method include, for example, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, benzene, toluene, acetonitrile, A single organic organic solvent such as methylene chloride, chloroform, dichloroethane, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, or a mixture of two or more thereof may be used, or a mixed solvent with water may be used.

  The polymerization temperature needs to be set in relation to the molecular weight of the polymer to be produced, the type of initiator, etc., and can be from 0 ° C. or lower to 100 ° C. or higher, but it is preferable to carry out the polymerization in the range of 50 to 100 ° C.

The reaction pressure can be selected as appropriate, but it is usually 1-100 kg / cm ² , particularly about 1-30 kg / cm ² . The reaction time is about 5 to 30 hours.

  As the reprecipitation solvent for the obtained polymer, isopropanol, hexane, methanol and the like are preferable.

Next, the inorganic fine particles (inorganic filler) that can be contained in the low refractive index layer of the present invention are described below.
The coating 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. If the amount is too large, fine irregularities are formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance are deteriorated.
Since the inorganic fine particles are contained in the low refractive index layer, it is desirable that the inorganic fine particles have a low refractive index. Examples thereof include fine particles of magnesium fluoride and silica. In particular, silica fine particles are preferable in terms of refractive index, dispersion stability, and cost. The average particle diameter of the silica fine particles is preferably 30% or more and 150% or less of the thickness of the low refractive index layer, more preferably 35% or more and 80% or less, and further preferably 40% or more and 60% or less. 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 150 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
If the particle size of the silica fine particles is too small, the effect of improving the scratch resistance is reduced. If it is too large, fine irregularities are formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance are deteriorated. The silica 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 a spherical diameter, but there is no problem even if the shape 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, it is preferable to use hollow silica fine particles, and the hollow silica fine particles have a refractive index of 1.17 to 1.40, more preferably 1.17 to 1. .35, more preferably 1.17 to 1.30. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell silica forming the hollow silica particles. At this time, represented the radius of the cavity inside the particle a, in When the radius of the outer shell of the particle b, formula (VIII) [x = (4πa 3/3) / (4πb 3/3) × 100] The porosity x is preferably 10 to 60%, more preferably 20 to 60%, and most preferably 30 to 60%.
If the hollow silica particles are made to have a lower refractive index and a higher porosity, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. From the viewpoint of scratch resistance, the low refractive index is less than 1.17. Rate particles do not hold.
The refractive index of these hollow silica particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

Further, at least one kind of silica fine particles having an average particle size of less than 25% of the thickness of the low refractive index layer (referred to as “small size particle size silica particles”) is used as silica fine particles having the above particle size (“large size particles”). It is preferably used in combination with “silica fine particles having a diameter”.
Since the fine silica particles having a small size can be present in the gaps between the fine silica particles having a large size, the fine particles can contribute as a retaining agent for the fine silica particles having a large size.
When the low refractive index layer is 100 nm, the average particle size of the silica fine particles having a small size is preferably from 1 nm to 20 nm, more preferably from 5 nm to 15 nm, and particularly preferably from 10 nm to 15 nm. Use of such silica fine particles is preferable in terms of raw material costs and a retaining agent effect.

Silica fine particles are treated with a 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 increase the affinity and binding to the binder component. Further, chemical surface treatment with a surfactant, a coupling agent or the like may be performed. 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. Among these, silane coupling treatment is particularly effective.
The above coupling agent is used as a surface treatment agent for the inorganic filler 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 silica fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.
What has been described above for silica fine particles also applies to other inorganic fine particles.

  The composition for forming a low refractive index layer of the present invention is usually in the form of a liquid, and the copolymer is an essential constituent, and various additives and a radical polymerization initiator are dissolved in an appropriate solvent as necessary. Produced. 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. %.

  From the viewpoint of film hardness of the low refractive index layer, it is not always advantageous to add an additive such as a curing agent, but from the viewpoint of interfacial adhesion with other layers, a polyfunctional (meth) acrylate compound, A small amount of a curing agent such as a functional epoxy compound, a polyisocyanate compound, an aminoplast, a polybasic acid or an anhydride thereof, or inorganic fine particles such as silica may be added. When adding these, it is preferable that it is the range of 0-30 mass% with respect to the total solid of a low refractive index layer membrane | film | coat, It is more preferable that it is the range of 0-20 mass%, 0-10 mass % Range is particularly preferred.

  For the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipping properties, known silicone-based or fluorine-based antifouling agents, slipping agents, and the like can 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 preferable silicone compounds include 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), Chisso Corporation, FM-0725, FM-7725, DMS-U22, RMS-033, RMS-083, UMS-182 (named above), etc. It is not limited to.

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 group, perfluorocyclopentyl, etc. 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 CH 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, R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink, Megafac F-171. , F-172, F-179A, Defender MCF-300 (named above), but not limited thereto.

  For the purpose of imparting properties such as dust resistance and antistatic properties, a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, or the like can be appropriately added. 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 refractive index layer. Particularly preferred is 0.1 to 5% by mass. Examples of preferable compounds include, but are not limited to, Dainippon Ink Co., Ltd., MegaFuck F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

[Coating solvent]
In the antireflection film of the present invention, the solvent composition of the coating solution used for forming the light diffusion layer, the antistatic layer, and the low refractive index layer is preferably a ketone solvent or an aromatic hydrocarbon solvent. Particularly preferred are ketone solvents. The solvent may be either alone or mixed, and when mixed, the content of the ketone solvent is preferably 10% by mass or more of the total solvent contained in the coating composition. Preferably it is 30 mass% or more, More preferably, it is 60 mass% or more.

  The coating solvent may contain a solvent other than the ketone solvent. For example, as a solvent having a boiling point of 100 ° C. or lower, hexane (boiling point 68.7 ° C., hereinafter “° C.” is omitted), heptane (98.4), cyclohexane (80.7), benzene (80.1), etc. Hydrocarbons such as dichloromethane (39.8), chloroform (61.2), carbon tetrachloride (76.8), 1,2-dichloroethane (83.5), trichloroethylene (87.2), etc. Hydrogens, diethyl ether (34.6), diisopropyl ether (68.5), dipropyl ether (90.5), ethers such as tetrahydrofuran (66), ethyl formate (54.2), methyl acetate (57. 8), esters such as ethyl acetate (77.1), isopropyl acetate (89), acetone (56.1), 2? Ketones such as butanone (= methyl ethyl ketone, 79.6), alcohols such as methanol (64.5), ethanol (78.3), 2-propanol (82.4), 1-propanol (97.2), And cyano compounds such as acetonitrile (81.6) and propionitrile (97.4), carbon disulfide (46.2), 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 higher include, for example, octane (125.7), toluene (110.6), xylene (138), tetrachloroethylene (121.2), chlorobenzene (131.7), dioxane (101.3). ), Dibutyl ether (142.4), isobutyl acetate (118), cyclohexanone (155.7), 2-methyl-4-pentanone (= MIBK, 115.9), 1-butanol (117.7), N, N-dimethylformamide (153), N, N-dimethylacetamide (166), dimethyl sulfoxide (189), and the like. Cyclohexanone and 2-methyl-4-pentanone are preferable.

By diluting the light diffusing layer, the antistatic layer and the low refractive index layer component of the present invention with the solvent having the above-mentioned composition, a coating solution for these layers is prepared. The concentration of the coating solution is preferably adjusted as appropriate in consideration of the viscosity of the coating solution and the specific gravity of the layer material, but is preferably 0.1 to 20% by mass, more preferably 1 to 10% by mass.
Moreover, the solvent of each functional layer and the low refractive index layer may be the same composition, and may differ.

[Inorganic filler]
In the antireflection film of the present invention, an inorganic filler is preferably added to each layer on the transparent support. The inorganic filler added to each layer may be the same or different, and the type and amount added are preferably adjusted appropriately according to the required performance such as the refractive index, film strength, film thickness, and coatability of each layer. .

The shape of the inorganic filler used in the present invention is not particularly limited, and for example, any of a spherical shape, a plate shape, a fiber shape, a rod shape, an indeterminate shape, a hollow shape, and the like are preferably used. Good and more preferable. Further, the kind of the inorganic filler is not particularly limited, but an amorphous one is preferably used, and a metal oxide, nitride, sulfide or halide is preferably used. Is particularly preferred. As metal atoms, Na, K, Mg, Ca, Ba, Al, Zn, Fe, Cu, Ti, Sn, In, W, Y, Sb, Mn, Ga, V, Nb, Ta, Ag, Si, B Bi, Mo, Ce, Cd, Be, Pb, Zr, Ni and the like. Although the average particle diameter of an inorganic filler changes with layers to add, in order to obtain a transparent cured film, it is preferable to set it as the value within the range of 0.001-0.2 micrometer, More preferably, it is 0.001. It is -0.1 micrometer, More preferably, it is 0.001-0.06 micrometer. Here, the average particle diameter of the particles is measured by a Coulter counter.
Although the usage method of the inorganic filler in this invention is not restrict | limited in particular, For example, it can use in a dry state or can also be used in the state disperse | distributed to water or the organic solvent.

  In the present invention, for the purpose of suppressing aggregation and sedimentation of the inorganic filler, it is also preferable to use a dispersion stabilizer in combination with the coating solution for forming each layer. As the dispersion stabilizer, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivative, polyamide, phosphate ester, polyether, surfactant, silane coupling agent, titanium coupling agent and the like can be used. In particular, a silane coupling agent is preferable because the film after curing is strong. Although the addition amount of the silane coupling agent as a dispersion stabilizer is not particularly limited, for example, the value is preferably 1 part by mass or more with respect to 100 parts by mass of the inorganic filler. Also, the method of adding the dispersion stabilizer is not particularly limited, but a hydrolyzed one can be added, or a dispersion stabilizer silane coupling agent and an inorganic filler are mixed. Thereafter, a method of further hydrolysis and condensation can be employed, but the latter is more preferable.

[Transparent support]
As the transparent support of the antireflection film of the present invention, a plastic film is preferably used. Examples of the polymer forming the plastic film include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, typically TAC-TD80U, TD80UF, etc. manufactured by Fuji Photo Film), polyamide, polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene). Naphthalate), polystyrene, polyolefin, norbornene-based resin (Arton: trade name, manufactured by JSR Corporation), amorphous polyolefin (ZEONEX: trade name, manufactured by Nippon Zeon Corporation), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable, and triacetyl cellulose is particularly preferable.

  Triacetyl cellulose consists of a single layer or a plurality of layers. Single-layer triacetyl cellulose is prepared by drum casting or band casting disclosed in JP-A-7-11055, and the latter triacetyl cellulose is a special feature of the published patent publication. It is prepared by the so-called co-casting method disclosed in Japanese Utility Model Publication Nos. 61-94725 and 62-43846. That is, the raw material flakes are solvents such as halogenated hydrocarbons (dichloromethane, alcohols (methanol, ethanol, butanol, etc.), esters (methyl formate, methyl acetate, etc.), ethers (dioxane, dioxolane, diethyl ether, etc.), etc. A solution (called a dope) with various additives such as a plasticizer, an ultraviolet absorber, an anti-degradation agent, a slipping agent, and a peeling accelerator is added to the horizontal endless as necessary. When casting by a dope supply means (called a die) on a support composed of a metal belt or a rotating drum, a single dope is cast in a single layer if it is a single layer, and a high concentration in the case of multiple layers. A low-concentration dope is co-cast on both sides of the cellulose ester dope, and the film is dried to some extent on the support to release the rigid film, and then peeled off from the support. A process comprising passed through a drying section by species of the conveying means to remove the solvent.

  A typical solvent for dissolving triacetylcellulose as described above is dichloromethane. However, from the viewpoint of the global environment and working environment, the solvent preferably does not substantially contain a halogenated hydrocarbon such as dichloromethane. “Substantially free” means that the proportion of halogenated hydrocarbon in the organic solvent is less than 5% by mass (preferably less than 2% by mass). In preparing a triacetyl cellulose dope using a solvent substantially free of dichloromethane or the like, a special dissolution method as described later is essential.

  The first dissolution method is called a cooling dissolution method and will be described below. First, triacetyl cellulose is gradually added to a solvent at a temperature around room temperature (-10 to 40 ° C.) while stirring. Next, the mixture is -100 ~? Cool to 10 ° C (preferably -80 to -10 ° C, more preferably -50 to -20 ° C, most preferably -50 to -30 ° C). The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a cooled diethylene glycol solution (−30 to −20 ° C.). When cooled in this manner, the mixture of triacetyl cellulose and solvent solidifies. Furthermore, when this is heated to 0 to 200 ° C. (preferably 0 to 150 ° C., more preferably 0 to 120 ° C., most preferably 0 to 50 ° C.), a solution in which triacetyl cellulose flows in the solvent is obtained. The temperature can be raised by simply leaving it at room temperature or in a warm bath.

  The second method is called a high temperature melting method and will be described below. First, triacetyl cellulose is gradually added to a solvent at a temperature around room temperature (-10 to 40 ° C.) while stirring. The triacetyl cellulose solution of the present invention is preferably swollen beforehand by adding triacetyl cellulose to a mixed solvent containing various solvents. In this method, the dissolution concentration of triacetyl cellulose is preferably 30% by mass or less, but is preferably as high as possible from the viewpoint of drying efficiency during film formation. Next, the organic solvent mixed solution is heated to 70 to 240 ° C. under a pressure of 0.2 MPa to 30 MPa (preferably 80 to 220 ° C., more preferably 100 to 200 ° C., most preferably 100 to 190 ° C.). Next, since these heated solutions cannot be applied as they are, it is necessary to cool them below the lowest boiling point of the solvent used. In that case,? It is common to cool to 10-50 degreeC and to return to a normal pressure. For cooling, the high-pressure and high-temperature vessel or line containing the triacetylcellulose solution may be left at room temperature, and more preferably, the apparatus may be cooled using a coolant such as cooling water. A cellulose acetate film substantially free of halogenated hydrocarbons such as dichloromethane and a process for producing the same are disclosed in JIII Journal of Technical Disclosure (Publication No. 2001-1745, published on March 15, 2001, hereinafter Published Technical Report 2001-1745). (Abbreviated as No.).

  When the antireflection film of the present invention is used in a liquid crystal display device, it is disposed on the outermost surface of the display by providing an adhesive layer on one side. When the transparent support is triacetylcellulose, triacetylcellulose is used as a protective film for protecting the polarizing layer of the polarizing plate. Therefore, it is preferable in terms of cost to use the antireflection film of the present invention as it is for the protective film.

When the antireflection film of the present invention is disposed on the outermost surface of a display by providing an adhesive layer on one side or used as it is as a protective film for a polarizing plate, it is a transparent support for sufficient adhesion. It is preferable to carry out a saponification treatment after forming an outermost layer mainly composed of a fluorine-containing polymer. The saponification treatment is performed by a known method, for example, by immersing the film in an alkali solution for an appropriate time. After being immersed in the alkali solution, it is preferable to sufficiently wash with water or neutralize the alkali component by immersing in a dilute acid so that the alkali component does not remain in the film.
By the saponification treatment, the surface of the transparent support opposite to the side having the outermost layer is hydrophilized.
The hydrophilized surface is particularly effective for improving the adhesion with a deflection film containing polyvinyl alcohol as a main component. In addition, the hydrophilic surface makes it difficult for dust in the air to adhere to it, so it is difficult for dust to enter between the deflection film and the antireflection film when bonded to the deflection film, thus preventing point defects due to dust. It is valid.
The saponification treatment is preferably carried out so that the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. More preferably, it is 30 ° or less, particularly preferably 20 ° or less.

Specific means for the alkali saponification treatment can be selected from the following two means (1) and (2). (1) is superior in that it can be processed in the same process as a general-purpose triacetylcellulose film, but since the surface of the antireflection film is saponified, the surface is alkali-hydrolyzed and the film deteriorates. The point that it becomes dirty when the liquid remains can be a problem. In that case, although it becomes a special process, (2) is excellent.
(1) After the antireflection layer is formed on the transparent support, the back surface of the film is saponified by immersing it in an alkaline solution at least once.
(2) Before or after the formation of the antireflection layer on the transparent support, an alkaline solution is applied to the surface of the antireflection film opposite to the surface on which the antireflection film is formed, and is heated, washed and / or washed. By summing, only the back surface of the film is saponified.

[Method for producing antireflection film]
The antireflection film of the present invention can be formed by the following method, but is not limited to this method.
First, a coating solution containing components for forming each layer is prepared. Next, in the case of forming a hard coat layer, a coating solution for forming the hard coat layer is prepared by using 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. The coating is applied onto a transparent support by a method or an extrusion coating method (see U.S. Pat. No. 2,681,294), followed by heating and drying. A microgravure coating method is particularly preferred. Thereafter, the monomer for forming the hard coat layer is polymerized and cured by light irradiation or heating. Thereby, a hard coat layer is formed.
Here, if necessary, a plurality of hard coat layers can be formed, and smooth hard coat layer application and curing can be performed by the same method before the light diffusion layer application.
Next, in the same manner, a coating liquid for forming a light diffusion layer is applied on the hard coat layer, and light irradiation or heating is performed to form the light diffusion layer. Subsequently, a coating liquid for forming a low refractive index layer is applied onto the light diffusion layer, and light irradiation or heating is performed to form the low refractive index layer. In this way, the antireflection film of the present invention is obtained.

  The micro gravure coating method used in the present invention is a gravure roll having a diameter of about 10 to 100 mm, preferably about 20 to 50 mm and engraved with a gravure pattern on the entire circumference, below the support and in the transport direction of the support. The gravure roll is rotated in reverse with respect to the gravure roll, the excess coating liquid is scraped off from the surface of the gravure roll by a doctor blade, and a fixed amount of the coating liquid is removed from the support in a position where the upper surface of the support is in a free state. The coating method is characterized in that the coating liquid is transferred onto the lower surface for coating. A roll-shaped transparent support is continuously unwound, and at least one layer of at least one of a hard coat layer or a low refractive index layer containing a fluorine-containing polymer is provided on one side of the unwound support. Can be applied by.

  As coating conditions by the micro gravure coating method, the number of gravure patterns imprinted on the gravure roll is preferably 50 to 800 lines / inch, more preferably 100 to 300 lines / inch, and the depth of the gravure pattern is 1 to 600 μm. Is preferable, 5 to 200 μm is more preferable, the rotation speed of the gravure roll is preferably 3 to 800 rpm, more preferably 5 to 200 rpm, and the conveyance speed of the support is 0.5 to 100 m / min. It is preferably 1 to 50 m / min.

In the antireflection film of the present invention, since the light diffusion layer and the low refractive index layer are laminated by coating, bright spot defects are easily noticeable when foreign matters such as dust and dust are present. The bright spot defect in the present invention is a defect that is visually observed by reflection on the coating film, and can be detected by an operation such as black coating on the back surface of the antireflection film after coating. The bright spot defects that can be visually observed are generally 50 μm or more in size. (Hereinafter, such bright spot defects are referred to as “bright spot defects”).
In the antireflection film of the present invention, the number of bright spot defects is 20 or less per square meter, preferably 10 or less, more preferably 5 or less, and particularly preferably 1 or less. By setting the number of bright spot defects to 20 or less per square meter, the bright spot defects can be made inconspicuous as a whole film. This effect is particularly remarkable when the color of the reflected light is neutral (having a ^* and b ^* values described later).

  In order to continuously produce the antireflection film of the present invention, a process of continuously feeding a roll-shaped support film, a process of applying and drying a coating liquid, a process of curing a coating film, and a support having a cured layer A step of winding the body film is performed. An example of such a process is shown in FIG.

  In FIG. 2, the film support is continuously sent out from the roll-shaped film support 11 to the clean chamber 15, and the static electricity charged on the film support is discharged by the electrostatic discharger 12 in the clean chamber 15. Subsequently, the foreign matter adhering to the film support is removed by the dust removing device 13. Subsequently, the coating solution is applied onto the film support in the application unit 14 installed in the clean chamber 15, and the applied film support is sent to the drying chamber 16 and dried. The film support having the dried coating layer is fed from the drying chamber 16 to the radiation curing chamber 17, and irradiated with radiation, the monomer contained in the coating layer is polymerized and cured. Further, the film support having a layer cured by radiation is sent to the thermosetting section 18 and heated to complete the curing, and the film support 19 having the cured layer is wound up into a roll shape.

  The above steps may be performed every time each layer is formed, or a plurality of coating units-drying chambers-radiation curing units-thermosetting chambers may be provided to continuously form each layer.

  In order to produce an antireflection film with few bright spot defects in the present invention, the coating process in the coating unit 14 and the drying process performed in the drying chamber 16 are performed in a highly clean air atmosphere and are coated. It is preferable that dust and dust on the film support have been sufficiently removed before this is performed. The air cleanliness of the coating process and the drying process is desirably class 10 (353 particles / 0.5 m or more / (cubic meter) or less) based on the standard of air cleanliness in the US Federal Standard 209E. Preferably it is class 1 (35.5 particles / (cubic meter) or less) having a particle size of 0.5 μm or more. Moreover, it is more preferable that the degree of air cleanliness is high also in the feeding and winding parts other than the coating-drying process.

  As a dust removal method used in a dust removal step as a pre-process for coating, a method of pressing a nonwoven fabric, a blade or the like against the film surface described in JP-A-59-150571, described in JP-A-10-309553 Highly clean air is blown at a high speed to peel off the deposit from the film surface, and suction is performed at a suction port adjacent to the film. Ultrasonic-vibrated compressed air described in JP-A-7-333613 is sprayed to deposit. And a dry dust removal method such as a method of peeling and suctioning (manufactured by Shinkosha, New Ultra Cleaner, etc.). In addition, a method of introducing a film into a cleaning tank and peeling off deposits with an ultrasonic vibrator, supplying a cleaning liquid to the film described in Japanese Patent Publication No. 49-13020, and then blowing and sucking high-speed air As described in JP-A-2001-38306, a wet dust removal method such as a method in which a web is continuously rubbed with a roll wetted with a liquid and then the liquid is sprayed onto the rubbed surface for cleaning. be able to. Among such dust removal methods, a method using ultrasonic dust removal or a method using wet dust removal is particularly preferable in terms of dust removal effect.

  In addition, it is particularly preferable to remove static electricity on the film support before performing such a dust removal step from the viewpoint of increasing dust removal efficiency and suppressing adhesion of dust. As such a static elimination method, a corona discharge ionizer, a light irradiation ionizer such as UV or soft X-ray, or the like can be used. The charged voltage of the film support before and after dust removal and coating is desirably 1000 V or less, preferably 300 V or less, and particularly preferably 100 V or less.

  Moreover, it is preferable to filter the coating liquid used for application | coating just before application | coating. As a filter for filtration, it is preferable to use a filter having a pore diameter as small as possible within a range in which components in the coating solution are not removed.

[Various performances of antireflection film]
The antireflection film of the present invention preferably has a haze value of 3 to 70%, more preferably 4 to 60%. The average reflectance from 450 nm to 650 nm is preferably 3.0% or less, more preferably 2.5% or less.
When the antireflection film of the present invention has a haze value and an average reflectance in the above range, good antiglare properties and antireflection properties can be obtained without causing deterioration of the transmitted image.

The antireflection film of the present invention has CIE1976L ^* a ^* b ^* color space a ^* and b ^* values of specular reflection light with respect to 5 degree incident light of CIE standard light source D65 in the wavelength range of 380 nm to 780 nm, respectively. ≦ a ^* ≦ 7, −10 ≦ b ^* ≦ 10 is preferable, and 0 ≦ a ^* ≦ 5 and −7 ≦ b ^* ≦ 0 are more preferable. By setting the color of the specularly reflected light from the antireflection film in the above range, when the film is applied to a liquid crystal display device, even when bright external light such as an indoor fluorescent lamp is reflected. It is preferable because the color is neutral and not concerned. When a ^* > 7, redness is strong, and when a ^* <− 7, cyan is strong, which is not preferable. Further, b ^* <-7 is not preferable because bluish color is strong, and b ^* > 0 is not preferable because yellow color becomes strong.
Measurement of the color of the antireflection film (measurement of a ^* , b ^* value) is performed by attaching an adapter ARV-474 (trade name) to a spectrophotometer V-550 (trade name, manufactured by JASCO Corporation). In the wavelength region of 380 to 780 nm, the specular reflectance at an incident angle of -5 degrees at an incident angle of 5 degrees is measured, and from the measured reflection spectrum, the color of specularly reflected light with respect to 5 degrees incident light of the CIE standard light source D65 This can be done by calculating the a ^* and b ^* values of the CIE 1976L ^* a ^* b ^* color space that represents.

[Polarizer]
The polarizing plate of the present invention is mainly composed of a polarizer and two protective films sandwiching the polarizer from both sides. The antireflection film of the present invention is preferably used for at least one of the two protective films sandwiching the polarizer from both sides. Since the antireflection film of the present invention also serves as a protective film, the production cost of the polarizing plate can be reduced. In addition, by using the antireflection film of the present invention as the outermost layer, reflection of external light and the like can be prevented, and a polarizing plate excellent in antiglare property and the like can be obtained.

As the polarizer, a known polarizing film or a polarizing film cut out from a long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction may be used. A long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction is produced by the following method.
That is, with a polarizing film stretched by applying tension while holding both ends of a continuously supplied polymer film by a holding means, stretched at least 1.1 to 20.0 times in the film width direction, The progress of the film is such that the difference between the moving speeds in the longitudinal direction of the holding device is within 3%, and the angle formed between the moving direction of the film at the exit of the process of holding both ends of the film and the substantial stretching direction of the film is inclined by 20 to 70 °. It can be produced by a stretching method in which the direction is bent while holding both ends of the film. In particular, those inclined by 45 ° are preferably used from the viewpoint of productivity.

  The method for stretching the polymer film is described in detail in paragraphs 0020 to 0030 of JP-A-2002-86554.

  The antireflection film of the present invention can be applied to an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), or a cathode ray tube display device (CRT). Since the antireflection film of the present invention has a transparent support, the transparent support side is adhered to the image display surface of the image display device.

  The antireflection film of the present invention, when used as one side of the surface protective film of the polarizing film, is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optical It can be preferably used for a transmissive, reflective, or transflective liquid crystal display device of a mode such as a curry compensate bend cell (OCB).

  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-). (2) In addition to (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Collection) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for viewing angle expansion ), (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).

  The OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. It is disclosed in the specifications of Japanese Patent Nos. 45882525 and 5410422. 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 also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

  In an ECB mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and is most frequently used as a color TFT liquid crystal display device, and is described in many documents. For example, it is described in “EL, PDP, LCD display” published by Toray Research Center (2001).

  In particular, for TN mode and IPS mode liquid crystal display devices, as described in JP-A-2001-100043, an optical compensation film having a viewing angle widening effect is included in the two protective films on the back and front of the polarizing film. By using it on the surface opposite to the antireflection film of the present invention, a polarizing plate having an antireflection effect and a viewing angle expansion effect can be obtained with the thickness of one polarizing plate, which is particularly preferable.

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited thereto. Unless otherwise specified, “part” and “%” are based on mass.

(Synthesis of perfluoroolefin copolymer (1))
Into a stainless steel autoclave with a stirrer 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. Furthermore, 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 5.4 kg / cm ² . The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 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 perfluoroolefin copolymer (1). The resulting polymer had a refractive index of 1.421.

(Synthesis of fluorine-based surface modifier FP-1)
In a reactor equipped with a stirrer and a reflux condenser, 39.93 g of 1H, 1H, 7H-dodecafluoroheptyl acrylate, 1.1 g of dimethyl 2,2′-azobisisobutyrate and 30 g of 2-butanone were added, and the atmosphere was nitrogen. For 6 hours at 78 ° C. to complete the reaction. The mass average molecular weight was 2.9 × 10 ⁴ .

(Preparation of sol solution a)
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. After that, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain sol solution a. The mass average molecular weight was 1600, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100%. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

(Preparation of coating solution A for light diffusion layer)
50 g of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (PETA, Nippon Kayaku Co., Ltd.) was diluted with 38.5 g of toluene. Furthermore, 2 g of a polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was added and mixed and stirred. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.51.
Further, a 30% toluene dispersion of crosslinked polystyrene particles having an average particle size of 3.5 μm (refractive index: 1.60, SX-350, manufactured by Soken Chemical Co., Ltd.) dispersed in this solution for 20 minutes at 10,000 rpm with a Polytron disperser. Add 13.3 g of a 30% toluene dispersion of 1.7 g and crosslinked acrylic-styrene particles having an average particle size of 3.5 μm (refractive index 1.55, manufactured by Soken Chemical Co., Ltd.), and finally, fluorine-based surface modification Agent FP-1, 0.75 g, and 10 g of silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to obtain a finished solution.
The mixture solution was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a coating solution A for the light diffusion layer.

(Preparation of coating solution B for light diffusion layer)
285 g of commercially available zirconia-containing UV curable hard coat liquid (Desolite Z7404, manufactured by JSR Corporation, solid content concentration of about 61%, ZrO ₂ content of solid content of about 70%, polymerizable monomer, polymerization initiator contained), dipenta 85 g of a mixture of erythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was mixed, and further diluted with 60 g of methyl isobutyl ketone and 17 g of methyl ethyl ketone. Furthermore, 28 g of a silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed and stirred. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61.
Further, a 30% methyl isobutyl ketone dispersion of classified strengthened crosslinked PMMA particles (refractive index: 1.49, MXS-300, manufactured by Soken Chemical Co., Ltd.) having an average particle size of 3.0 μm was added to this solution at 10,000 rpm with a Polytron disperser. 35 g of a dispersion dispersed for 20 minutes was added, and then a 30% methyl ethyl ketone dispersion of silica particles having an average particle diameter of 1.5 μm (refractive index 1.46, Seahosta KE-P150, manufactured by Nippon Shokubai Co., Ltd.) 90 g of a dispersion dispersed at 10,000 rpm for 30 minutes was added, and finally 0.12 g of a fluorine-based surface modifier (FP-1) was mixed and stirred to obtain a finished solution.
The mixture solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution B for the light diffusion layer.

(Preparation of coating solution C for light diffusion layer)
Instead of the crosslinked PMMA having an average particle size of 3.0 μm and the silica particles having an average particle size of 1.5 μm in the coating solution B for light diffusion layer, crosslinked polystyrene particles having an average particle size of 3.5 μm (refractive index 1.61, SX -350, manufactured by Soken Chemical Co., Ltd.) A light diffusion layer coating solution C was prepared by simply replacing the 30% toluene dispersion with an equal mass.
(Preparation of coating solutions D to F for light diffusion layer)
In the light diffusion layer coating liquid C, the zirconia content is appropriately changed, and the refractive index of the cured film excluding the crosslinked polystyrene particles is 1.55, 1.70, 1.82. ~ F was created.

(Adjustment of coating solution A for low refractive index layer)
Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.42 (JN7228A, solid content concentration 6%, manufactured by JSR Corporation) 13 g, silica sol (silica, MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30 %, Nissan Chemical Co., Ltd.) 1.3 g, sol liquid 0.6 g, methyl ethyl ketone 5 g, and cyclohexano 0.6 g were added. After stirring, the mixture was filtered through a polypropylene filter having a pore size of 1 μm for a low refractive index layer. A coating solution A was prepared. The refractive index of the cured film was 1.42.

(Adjustment of coating liquid B for low refractive index layer)
In the coating liquid A for the low refractive index layer, the coating liquid including the addition amount is used except that 1.95 g of hollow silica sol (refractive index 1.31, average particle size 60 nm, solid content concentration 20%) is used instead of silica sol. In the same manner as A, a coating solution B for a low refractive index layer was prepared. The refractive index of the cured film was 1.39.

(Preparation of coating solution C for low refractive index layer)
In the coating solution for the low refractive index layer, curing is achieved by replacing a part of the thermally crosslinkable fluorine-containing polymer with a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.). The film was prepared so that the refractive index of the film was 1.51, and a coating liquid C for low refractive index layer was prepared.

(Preparation of coating solution D for low refractive index layer)
MTEOS is dissolved in methyl ethyl ketone as a solvent so that the solid content concentration becomes 3% by weight when it is assumed that methyltriethoxysilane (MTEOS) is ideally hydrolyzed and condensed to SiO ₂ or MeSiO _1.5. The mixture was stirred for 30 minutes until the temperature was stabilized at 25 ° C. (A solution). Hydrochloric acid having a concentration of 0.005 mol / l as a catalyst was added to the A liquid in an equimolar amount with the alkoxide group of MTEOS and hydrolyzed at 25 ° C. for 3 hours (liquid B). A mixture of sodium acetate and acetic acid as a curing agent was added to this B liquid and stirred at 25 ° C. for 1 hour to obtain a SiO ₂ sol liquid. The refractive index of the cured film was 1.40.

(Preparation of coating solution E for low refractive index layer)
15.2 g of perfluoroolefin copolymer (1), silica sol (silica, MEK-ST with different particle size, average particle size 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Co., Ltd.) 1.4 g, reactive silicone X-22-164B (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 g, sol solution a 7.3 g, photopolymerization initiator (Irgacure 907 (trade name), manufactured by Ciba Geigy) 0.76 g, methyl ethyl ketone 301 g, cyclohexanone 9 After adding 0.0 g and stirring, the mixture was filtered through a polypropylene filter having a pore size of 5 μm to prepare a coating solution D for a low refractive index layer. The refractive index of the cured film was 1.42.

[Example 1]
(1) Coating of light diffusion layer An 80 μm-thick triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) is unwound in the form of a roll, and the light diffusion layer coating liquid A is lined up. Using a gravure roll with a diameter of 40 mm and a doctor blade with a gravure pattern of several 180 lines / inch and a depth of 40 μm, it was applied at a gravure roll rotation speed of 30 rpm and a conveying speed of 30 m / min, and dried at 60 ° C. for 150 seconds. Then, using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge, the coating layer is cured by irradiating ultraviolet rays with an illuminance of 400 mW / cm ² and an irradiation amount of 250 mJ / cm ^2. A functional layer having a thickness of 6 μm was formed and wound up.

(2) Coating of low refractive index layer The triacetyl cellulose film coated with the light diffusing layer is unwound again, and the low refractive index layer coating solution A is a gravure pattern with 180 lines / inch and a depth of 40 μm. Using a micro gravure roll having a diameter of 50 mm and a doctor blade having a gravure roll rotation number of 30 rpm and a conveying speed of 15 m / min, applying at 120 ° C. for 150 seconds and further drying at 140 ° C. for 8 minutes. Using a 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge, UV light with an illuminance of 400 mW / cm ² and an irradiation amount of 900 mJ / cm ² is used and a low refractive index of 100 nm is obtained. A layer was formed and wound up (Sample 1).

Antireflection films of Samples 2 to 14 were produced in the same manner as Sample 1 except that the coating solution for the light diffusion layer and the low refractive index layer was changed as shown in Table 1 below.
In each of the samples 1 to 14, the thicknesses of the light diffusion layer and the low refractive index layer were finely adjusted, and the colors were set to a ^* = 2 and b ^* =-3.

For samples 1 to 10, the coating and drying steps are performed in an air atmosphere having an air cleanliness of 30 particles / cubic meter or less (air cleanliness class 1 or lower in US Federal Standard 209E) as particles of 0.5 μm or more. Immediately before coating, the coating was performed by removing dust from the surface of the film by blowing high-clean air described in JP-A-10-309553 at a high speed and removing the dust from the film by sucking it through the adjacent suction port. . The charged voltage of the base before dust removal was 200V or less. The above coating was performed for each layer in each step of feeding-dust removal-coating-drying- (UV or heat) curing-winding (condition 1).
Samples 11 to 14 were prepared as Samples 1 and 7 except that the air cleanliness in the coating / drying zone was 10000 particles / cubic meter or more (air cleanliness class 100 to 1000 in the US federal standard 209E) as 0.5 μm or more particles. 9 and 10 were used to prepare an antireflection film (Condition 2).
Table 1 shows the coating liquid for the light diffusion layer and the low refractive index layer of the prepared sample, and the conditions of air cleanliness during coating and drying.

(Saponification treatment of antireflection film)
After film formation, each sample was subjected to the following treatment.
A 1.5 mol / l aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / l dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The prepared antireflection film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.
In this way, a saponified antireflection film was prepared and evaluated as follows.

(Evaluation of antireflection film)
About the obtained antireflection film, the following items were evaluated. The results are shown in Table 2.

(1) Average reflectance Using a spectrophotometer (manufactured by JASCO Corporation), the spectral reflectance at an incident angle of 5 ° was measured in a wavelength region of 380 to 780 nm. For the results, an integrating sphere average reflectance of 450 to 650 nm was used.
(2) Steel wool scratch resistance evaluation A rubbing test was performed using a rubbing tester under the following conditions.
-Evaluation environmental conditions: 25 ° C, 60% RH
・ Rubbing material: Steel wool (manufactured by Nippon Steel Wool Co., Ltd., grade No. 0000) was wound around the rubbing tip (1 cm × 1 cm) of a tester that was in contact with the sample, and the band was fixed so as not to move.
Travel distance (one way): 13 cm, rubbing speed: 13 cm / sec, load: 500 g / cm ² , tip contact area: 1 cm × 1 cm, rubbing frequency: 10 reciprocations.
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.
A: Even if looked very carefully, no scratches were visible.
○: Slightly weak scratches are visible when viewed very carefully.
○ △: Weak scratches are visible.
Δ: Medium scratches are visible.
Δ × ˜ ×: There is a scratch that can be seen at first glance.

(3) Evaluation of resistance to rubbing with a cotton swab A cotton swab is fixed to the rubbing tip of a rubbing tester, and the upper and lower sides of the sample are fixed with clips in a smooth dish, and the sample and the swab are immersed in water at 25 ° C at room temperature 25 ° C. A rubbing test was performed by applying a load of 500 g and changing the number of rubbing. Rubing distance (one way): 1 cm, rubbing speed: about 2 reciprocations / second.
The rubbed sample was observed, and the rub resistance was evaluated as follows based on the number of times film peeling occurred.
X: film peeling with 0-10 reciprocation xΔ: film peeling with 10-30 reciprocation △: film peeling with 30-50 reciprocation ○ △: film peeling with 50-100 reciprocation ○: film peeling with 100-150 reciprocation ◎: 150 No film peeling even when reciprocating

(4) Bright spot defects The back side of the film after coating all the layers was black-coated with magic ink, and then the bright spot defects on the coating film were visually determined. “The number per square meter was counted.

  From Table 2, it is clear that the antireflection film of the present invention has few bright spot defects and low reflectance, and can improve image quality (contrast and viewing angle dependency) when applied to a liquid crystal display device. .

[Example 2]
[Preparation of dispersion for antistatic layer]
(Preparation of ATO dispersion)
20 parts by mass of ATO (antimony-containing tin oxide, specific surface area: 95 m ² / g, powder specific resistance: 2 Ω · cm), 3 parts by mass of the following anionic monomer (1), 3 parts by mass of the following anionic monomer (2) And 74 parts by mass of cyclohexanone was dispersed by a sand grinder mill to prepare an ATO dispersion.

(Preparation of coating solution A for antistatic layer)
In ATO dispersion, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.), photopolymerization initiator (Irgacure 907, Ciba Geigy), photosensitizer (Kayacure DETX) Nippon Kayaku Co., Ltd.), methyl ethyl ketone and cyclohexanone were added to prepare a coating solution for an antistatic layer. The added amount is 65/35 in the mass ratio of the total amount of monomers (total amount of dipentaerythritol hexaacrylate, anionic monomer (1) and anionic monomer (2)) and ATO, photoinitiator and photosensitizer. The mass ratio to the sensitizer is 3/1, the mass ratio of the total amount of photopolymerization initiator and photosensitizer to the total amount of monomers is 6/100, and the mass ratio of methyl ethyl ketone to cyclohexanone is 1/1. It adjusted so that it might become.

(Formation of antistatic layer)
Before applying the light diffusing layer in Samples 1, 9, 10, 11, 13, and 14 prepared in Example 1, the coating solution for the antistatic layer was uniformly applied with a bar coater, and the layer was irradiated with ultraviolet rays. Curing was performed to form an antistatic layer having a thickness (dry film thickness) of 6 μm, and Samples 15 to 20 were prepared. These were examined for bright spot defects in the same manner as in Example 1. The results are shown in Table 3. Samples 15 to 20 had the same performance as Samples 1, 9, 10, 11, 13, and 14 without the antistatic layer, except that they had few bright spots and excellent dust resistance.

[Example 3]
(Preparation of antistatic coating solution B)
Conductive polymer dispersion (IP-24 5% methanol dispersion, average particle size 0.2 μm)
10 parts by mass of cellulose diacetate resin (trade name: Acetate Flakes L-AC, manufactured by Daicel Chemical Industries, Ltd.)
0.2 parts by mass, 20 parts by mass of methanol, 40 parts by mass of acetone, 25 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol

(Preparation of antistatic coating solution C)
・ Cellulose diacetate resin (trade name: Acetate Flakes L-AC, manufactured by Daicel Chemical Industries, Ltd.)
0.1 parts by mass, 1% acetone-dispersed fine particle silica (trade name: Aerosil 200V, manufactured by Nippon Aerosil Co., Ltd.) 0.05 parts by mass, methyl ethyl ketone 40 parts by mass, ethyl acetate 30 parts by mass, isopropylene glycol 30 parts by mass

In the preparation of the antistatic layer of Samples 15 to 20 prepared in Example 2, the C liquid was further applied on the antistatic layer formed by applying the B liquid so that the application amount was 22 ml / m ^2. / M ^{2 was} applied to prepare Samples 21 to 26 on which an antistatic layer was formed. Similar to Example 2, the performance was the same as that of Samples 1, 9, 10, 11, 13, and 14 without the antistatic layer, except that the number of bright spots was small and the dust resistance was excellent. Furthermore, the same effect was acquired even if it changed the electroconductive polymer of B liquid to IP-11.

[Example 4]
(Preparation of coating solution F for low refractive index layer)
-Methyltrimethoxysilane 100 parts by mass-Dimethyldimethoxysilane 50 parts by mass-Silyl group-containing vinyl polymer (50% solid content): Compound PP-2 50 parts by mass-Diisopropoxyaluminum ethyl acetoacetate 20 parts by mass-Isopropyl alcohol 40 30 parts by mass of ion exchange water

(Preparation of coating solutions G and H for low refractive index layer)
Coating liquids G and H for the low refractive index layer were prepared by changing the silyl group-containing vinyl polymer (50% solid content) from compound PP-2 to compounds PP-12 and PP-15 in the preparation of the F solution.
The refractive index of the cured film obtained by curing the F to H liquids was 1.40.
Samples 27, 28, and 29 were prepared by changing the coating liquid for the low refractive index layer from the A liquid to the F to H liquids in the preparation of the sample 15 of Example 2. The coating solution for the low refractive index layer was applied and then dried and cured at 100 ° C. for 1 hour.
These samples were evaluated in the same manner as in Example 1. The results are shown in Table 4.

  From Table 4, it is clear that the antireflection film of the present invention has few bright spot defects and low reflectance, and can improve image quality (contrast and viewing angle dependency) when applied to a liquid crystal display device. .

[Example 5]
Sample 21 was prepared by changing the air cleanliness at the time of application when preparing Sample 15 prepared in Example 2, and further by finely adjusting the refractive index and film thickness of each layer, Sample 22 having a different color. ˜25 were created to evaluate the conspicuousness of bright spot defects.

These samples were mounted on the outermost layer of a liquid crystal display device to evaluate the preference for color and the conspicuousness of bright spot defects.
For the color tone, a fluorescent lamp was reflected on the screen when the power of the liquid crystal display device was turned off, and the neutrality of the reflected light was subjected to sensory evaluation (5: preferred to 1: not preferred).
The visibility of the bright spot defect was evaluated by observing the screen of the liquid crystal display device when the power was turned off to give a 5-point evaluation (5: not noticed at all: 1: easily noticed).

From Table 6, even if the a ^* and b ^* values of the CIE1976L ^* a ^* b ^* color space are −7 ≦ a * ≦ 7 and −10 ≦ b * ≦ 10, respectively, the number of bright spot defects is 20 / In the samples exceeding m ² (samples 11 and 18), the bright spot defects are conspicuous, but it becomes unnoticeable by setting the number of bright spot defects to 20 pieces / m ² or less. It can be seen that both the conspicuousness of defects can be achieved.

[Example 6]
The PVA film was immersed in an aqueous solution of 2.0 g / l iodine and 4.0 g / l potassium iodide at 25 ° C. for 240 seconds, and further immersed in an aqueous solution of boric acid 10 g / l at 25 ° C. for 60 seconds. Introduced into a tenter stretching machine of the form shown in FIG. 2 of 2002-86554, stretched 5.3 times, bent the tenter in the stretching direction as shown in FIG. 2 of the above publication, and thereafter kept the width constant. It was. After drying in an atmosphere of 80 ° C., it was detached from the tenter. The difference in transport speed between the left and right tenter clips was less than 0.05%, and the angle between the center line of the introduced film and the center line of the film sent to the next process was 46 °. The substantial stretching direction at the tenter outlet was inclined by 45 ° with respect to the center line 22 of the film sent to the next process. Wrinkles and film deformation at the tenter exit were not observed.
Further, it was bonded to TD80U (cellulose triacetate, retardation value: 3.0 nm) manufactured by Fuji Photo Film Co., Ltd., which had been saponified using an aqueous solution of PVA (manufactured by Kuraray Co., Ltd., PVA-117H) 3%, and further 80 ° C. And dried to obtain a polarizing plate having an effective width of 650 mm. The absorption axis direction of the obtained polarizing plate was inclined 45 ° with respect to the longitudinal direction. The polarizing plate had a transmittance at 550 nm of 43.7% and a polarization degree of 99.97%. Further, as shown in FIG. 2, when the substrate was cut into a size of 310 × 233 mm, a polarizing plate having an absorption efficiency of 91.5% and a 45 ° absorption axis inclined with respect to the side was obtained.
Next, the antireflection film of the present invention prepared in Examples 1 to 4 (saponified) was bonded to the above polarizing plate to prepare a polarizing plate with antiglare antireflection. Using this polarizing plate, a liquid crystal display device in which the antireflection film was arranged as the outermost layer was produced. As a result, there was no reflection of external light, and an excellent contrast was obtained, and the reflected image was conspicuous due to antiglare properties. It had excellent visibility.

[Example 7]
An 80 μm-thick triacetylcellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.), immersed in a 1.5 mol / l, 55 ° C. NaOH aqueous solution for 2 minutes, neutralized and washed with water, and Examples 1 was prepared by adsorbing iodine to polyvinyl alcohol and stretching the antireflective film of Sample 1 prepared in 1 (the saponification treatment of the triacetylcellulose film surface (adhesive surface with the polarizer) on the back surface). A polarizing plate was prepared by adhering and protecting both sides. The thus-prepared polarizing plate is a liquid crystal display device of a notebook personal computer equipped with a transmission type TN liquid crystal display device so that the antireflection film side is the outermost surface (Sumitomo 3M Co., Ltd., which is a polarization separation film having a polarization selection layer). When the polarizing plate on the viewing side of D-BEF made of D-BEF (having between the backlight and the liquid crystal cell) was replaced, a display device with extremely high display quality was obtained with very little background reflection.

[Example 8]
The antireflection film of this invention produced in Examples 1-4 was affixed as a visual recognition side protective film (protective film on the opposite side to the liquid crystal cell side) of the visual recognition side polarizing plate of a transmission type TN liquid crystal cell. As the protective film on the liquid crystal cell side of the viewing side polarizing plate and the protective film on the liquid crystal cell side of the polarizing plate on the backlight side, the disc surface of the discotic structural unit is inclined with respect to the transparent support surface, and the disco Viewing angle widening film (Wide View Film SA12B, Fuji Photo Film Co., Ltd.) having an optical compensation layer in which the angle formed by the disk surface of the tick structural unit and the transparent support surface changes in the depth direction of the optical anisotropic layer. As a result, a liquid crystal display device having excellent contrast in a bright room, extremely wide viewing angles in the vertical and horizontal directions, extremely excellent visibility, and high display quality was obtained.
In addition, when the antireflection film of Sample 2 (light diffusion layer coating liquid B) prepared in Example 1 was used, the scattered light intensity at 30 ° with respect to the emission angle of 0 ° was 0.06%. In particular, the viewing angle is improved in the downward direction and the yellowness in the left-right direction is improved, and the liquid crystal display device is very good. As a comparison, when an antireflection film produced in exactly the same manner as Sample 2 was used except that the crosslinked PMMA particles and silica particles were removed from the light diffusion layer coating solution B, 30 ° with respect to an emission angle of 0 °. The scattered light intensity was substantially 0%, and the downward viewing angle was increased and the yellowishness improving effect was not obtained at all.

[Example 9]
When the antireflection film of the present invention produced in Examples 1 to 4 is bonded to a glass plate on the surface of an organic EL display device via an adhesive, reflection on the glass surface is suppressed, and display with high visibility is achieved. A device was obtained.

[Example 10]
Using the antireflection film of the present invention prepared in Examples 1 to 4, a polarizing plate with a single-sided antireflection film was prepared, and a λ / 4 plate was placed on the opposite side of the polarizing plate having the antireflection film. When pasted and pasted on the glass plate on the surface of the organic EL display device, surface reflection and reflection from the inside of the surface glass were cut, and a display with extremely high visibility was obtained.

It is the schematic diagram which showed sectional drawing of embodiment of the antireflection film concerning this invention. It is the schematic diagram which showed an example of the application | coating process of an antireflection film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent support body 2 Functional layer 4 Low-refractive-index layer 6 Light-diffusion layer 7 Translucent particle 11 Film support body 12 Static electricity removal apparatus 13 Dust removal apparatus 14 Application | coating part 15 Clean room 16 Drying room 17 Radiation hardening part 18 Thermosetting room 19 Film support

Claims (12)

An antireflection film having at least a light diffusing layer and a low refractive index layer on a transparent support, wherein the light diffusing layer is at least one kind of translucent particle in a matrix made of at least a translucent resin. The refractive index difference between the matrix and the translucent particles is 0.02 to 0.2, the refractive index of the low refractive index layer is 1.20 to 1.50, 50 μm An antireflection film characterized in that the number of bright spot defects having the above size is 20 / m ² or less.   The antireflection film according to claim 1, further comprising at least one antistatic layer on the transparent support. The CIE 1976 L ^* a ^* b ^* color space a ^* and b ^* values of specularly reflected light with respect to 5 ° incident light of the CIE standard light source D65 in the wavelength range of 380 nm to 780 nm are −7 ≦ a ^* ≦ 7 and −10, respectively. The antireflection film according to claim 1, wherein ≦ b ^* ≦ 10.   The antistatic film according to any one of claims 1 to 3, wherein the antistatic layer contains at least one selected from an ionic polymer compound and conductive inorganic fine particles as a conductive material.   The antireflective film according to any one of claims 1 to 4, wherein the ionic polymer compound is a quaternary ammonium cationic polymer having molecular crosslinking. 6. The antireflection according to claim 1, wherein the ionic polymer compound is a polymer having a unit having a structure represented by the following general formulas (1), (1a) and (1b). the film.

In the general formula (1), R ₁ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom, or —CH ₂ COO ⁻ M ⁺ . Y represents a hydrogen atom or —COO ⁻ M ⁺ . L represents -CONH-, -COO-, -CO- or -O-. J represents an alkylene group having 1 to 12 carbon atoms or an arylene group. Q represents a group selected from the following group A.

M ⁺ represents a proton or a cation. R ₂ , R ₂ ′ and R ₂ ″ each independently represents an alkyl group having 1 to 4 carbon atoms. X ⁻ represents an anion. P and q each independently represent 0 or 1.

In the general formulas (1a) and (1b), R ₃ , R ₄ , R ₅ and R ₆ represent a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ₃ and R ₄ , R ₅ and R _6. May be bonded to each other to form a nitrogen-containing heterocycle. A, B and D are each independently a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, an arylene group, an alkenylene group, an arylene alkylene group, —R ₇ COR ₈ —, —R ₉ COOR ₁₀ OCOR ₁₁ —, — _{R 12 OCR 13 COOR 14 -,} - R 15 - (oR 16) m -, - R 17 CONHR 18 NHCOR 19 -, - R 20 OCONHR 21 NHCOR 22 - or -R ₂₃ NHCONHR ₂₄ NHCONHR ₂₅ - represents a. _{R 7, R 8, R 9} , R 11, R 12, R 14, R 15, R 16, R 17, R 19, R 20, R 22, R 23 and R ₂₅ represents an alkylene group. R ₁₀ , R ₁₃ , R ₁₈ , R ₂₁ and R ₂₄ each represent a linking group selected from a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylene alkylene group and alkylene arylene group. m represents a positive integer of 1 to 4. X- represents an anion. E represents a single bond, —NHCOR ₂₆ CONH— or a group selected from the above D. R ₂₆ represents a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylene alkylene group or alkylene arylene group. Z ₁ and Z ₂ represent a nonmetallic atom group necessary for forming a 5-membered or 6-membered ring together with the —N═C— group, and are represented by E in the form of a quaternary salt of ≡N ⁺ [X ⁻ ] —. You may connect. n represents an integer of 5 to 300. The low refractive index layer is formed from a composition containing a hydrolyzate of an organosilane compound (A) represented by the following general formula (2) and / or a partial condensate thereof: The antireflection film according to any one of 6.
General formula (2) (R) _m1 Si (X) _m2
In general formula (2), X represents —OH, a halogen atom, —OR ₃₀ or —OCOR ₃₀ . R and R ₃₀ each represent an alkyl group having 1 to 10 carbon atoms. m1 and m2 each represent an integer and satisfy m1 + m2 = 4. The composition containing the hydrolyzate of the organosilane compound (A) and / or its partial condensate contains the hydrolyzate of the following organosilanes (B) and (C) and / or its partial condensate: The composition contains a hydrolyzate of organosilane (C) and / or a partial condensate thereof in an amount of 2 to 150% by weight based on that of organosilane (B), and at least one of organosilane (B) and (C) is contained. The antireflection film according to claim 7, wherein R ₃₁ in the general formula has a fluorine atom.
(B) General formula (2b): R ₃₁ Si (X ₁ ) ₃ (wherein R ₃₁ is an organic group having 1 to 10 carbon atoms, and X ₁ has the same contents as X in the general formula (2)). Organosilane represented by:
(C) Organo represented by general formula (2c): (R ₃₁ ) ₂ Si (X ₁ ) ₂ (wherein R ₃₁ and X ₁ represent the same contents as defined in (B) above). Silane.   A composition containing a hydrolyzate of the organosilane compound (A) and / or a partial condensate thereof is a polymer of a silyl group having a silicon atom bonded to a hydrolyzable group and / or a hydroxyl group at a terminal or a side chain. The antireflection film according to claim 8, comprising a silyl group-containing vinyl polymer (D) having at least one silyl group therein.   10. The reflection according to claim 1, wherein the light diffusion layer and the low refractive index layer are formed in an air atmosphere having a cleanliness of class 10 or higher based on air cleanliness regulations in the US Federal Regulations 209E. Prevention film.   A polarizing plate having a polarizer sandwiched between two protective films, wherein at least one protective film is the antireflection film according to claim 1.   An image display device comprising the antireflection film according to claim 1 or the polarizing plate according to claim 11 on an outermost surface of the display.

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