WO2012020722A1 - Laminated polyester film and optical laminated film using same - Google Patents

Abstract

[Problem] To provide a laminated polyester film which is a highly adhesive film for optical use that has high processability and excellent adhesion to a hardcoat layer, while suppressing interference patterns when used as a base for a hardcoat film for optical use, said laminated polyester film not only suppressing interference patterns but also having achieved adhesion in high temperature and high humidity environments and coatability by an in-line coating method at high levels. [Solution] A laminated polyester film obtained by laminating a lamination layer (C layer) on at least one surface of a polyester film, which is characterized in that the minimum value of the spectral reflectance (Rmin) on the C layer side at a wavelength from 500 nm to 650 nm is 4.0-6.0% (inclusive) and the amount of change (?r) of the spectral reflectance is 0.0-1.0% (inclusive).

Description

Laminated polyester film and optical laminated film using the same

The present invention relates to a laminated polyester film having good suppression of interference fringes and adhesion to a hard coat agent comprising an active ray curable resin and the laminated polyester when used as a base material for an optical film for hard coat such as a touch panel. The present invention relates to an optical laminated film using a film.

Since an optical film for hard coat is required to have functions such as surface scratch resistance and antifouling properties, a method of providing a hard coat layer on a film substrate such as polyethylene terephthalate has been performed. In such a film, there is a problem in visibility because there is a clear interface with a difference in refractive index between the base film made of polyethylene terephthalate and the primer layer or hard coat layer provided on the surface. That is, when viewed from a certain angle, there are problems such as partial iris-like reflection, which impairs visibility, and poor adhesion. When an easy-adhesion layer is provided on the polyester film in order to improve the adhesion, the adhesion is improved, but the easy-adhesion layer and the base material layer, which generally have a lower refractive index than the base polyester film, and It was difficult to eliminate interference fringes due to the difference in refractive index with the hard coat layer.

Regarding the method of suppressing interference fringes generated when a hard coat layer is provided on such a laminated polyester film, the optical interface caused by the difference in refractive index between the easy adhesion layer, the base material layer and the hard coat layer is eliminated. Is the best way. As a method for solving this, there is a method in which two types of resins having different refractive indexes are used in the easy-adhesion layer and the refractive index is continuously improved from the surface layer of the easy-adhesion layer toward the base material layer (Patent Document 1). . However, in this method, the refractive index of the high refractive index resin is not sufficiently high, and the suppression of interference fringes at the interface between the easy adhesion layer and the base material layer is insufficient. Therefore, studies have been made to increase the refractive index of the resin itself by copolymerizing a monomer containing an aromatic substituent such as a fluorene group with the resin used in the easy adhesion layer (Patent Document 2). However, the polyester film before crystal orientation is completed is subjected to corona discharge treatment as necessary, and an easy-adhesive coating agent is applied, dried, then stretched and heat treated to complete crystal orientation, so-called in-line coating method. Despite the need for an aqueous dispersion of refractive index resin, high refractive index resin often has a rigid chemical structure, and a large amount of highly hydrophilic sulfonate group is used to disperse the resin in water. Therefore, there was a problem in adhesiveness in a high temperature and high humidity environment. In addition, a resin copolymerized with a fluorene group generally tends to have a high glass transition temperature, resulting in poor stretch following ability, poor applicability in the in-line coating method, and fine cracks in the easily adhesive layer. There existed problems, such as film haze getting worse, and the dispersion | variation in the surface reflectance by a place is large, and it is inferior to coating uniformity.

In addition, studies have been made to increase the refractive index of the easy-adhesion layer by providing an easy-adhesion layer containing high-refractive-index metal oxide fine particles such as titanium oxide particles on the polyester film (Patent Document 3). The coating method tends to cause problems such as film haze deterioration due to surface scattering by particle protrusions and generation of aggregated particles or voids at the particle / binder interface.

In addition, studies have been made to increase the refractive index of the easy-adhesion layer by providing an easy-adhesion layer containing a water-soluble titanium chelate compound or zirconium compound on the polyester film (Patent Document 4). And the content of zirconium is low, a large amount of chelate compound is required to improve the refractive index, and metal chelate compounds are decomposed by heat treatment. There was a concern that the quality of the optical laminated film may be lowered.

JP 2004-107627 A Japanese Patent Laid-Open No. 10-110091 JP 2001-330708 A JP 2005-097571 A

An object of the present invention is an optically easy-adhesive film excellent in suppression of interference fringes and excellent adhesion to a hard coat layer when used as a substrate for an optical film for hard coat, in a high-temperature and high-humidity environment. The object is to provide a laminated polyester film having both the adhesiveness and the property that realizes the applicability by the in-line coating method at a high level.

(1) A polyester film in which a laminated film (C layer) is laminated on at least one surface of a layer (S layer) made of polyester as a base material layer, at a wavelength of 500 nm to 650 nm on the C layer side A laminated polyester film having a minimum value (Rmin) of spectral reflectance of 4.0% to 6.0% and a change amount (Δr) of spectral reflectance of 0.0% to 1.0%.
(2) The C layer contains a polyester resin (A) having a fluorene skeleton and / or a naphthalene skeleton and an acrylic resin (Q), and the content (a) of the polyester resin (A) in the C layer and the acrylic resin The laminated polyester film according to (1), wherein the weight ratio (a) / (b) of the content (b) of (Q) is from 40/60 to 95/5.
(3) The laminated polyester film according to (2), wherein the wetting tension of the polyester resin (A) is higher than the wetting tension of the acrylic resin (Q), and the difference is 2 mN / m or more and 10 mN / m or less.
(4) The laminated polyester film according to (2) or (3), wherein the wetting tension of the polyester resin (A) is higher than the wetting tension of the acrylic resin (Q), and the difference is 2 mN / m or more and 6 or less.
(5) The polyester resin (A) has at least a fluorene skeleton, and the polyester resin (A) does not have a dicarboxylic acid component (Aa-3) having a sulfonate group, or the polyester resin (A The laminated polyester film according to any one of (2) to (4), which is less than 0.1 mol% based on the amount of the dicarboxylic acid component (Aa) constituting
(6) The laminated polyester film according to any one of (1) to (5), wherein the thickness tolerance of the C layer is 10 nm or less.
(7) The initial adhesion index of the surface of the C layer, the heat and heat resistance index when left in a constant temperature and humidity environment at a temperature of 80 ° C. and a relative humidity of 90%, and the adhesion index after boiling for 3 hours The laminated polyester film according to any one of (1) to (6), wherein all are 3 or more and 5 or less.
(8) A hard coat layer made of an actinic radiation curable resin is laminated on the surface of layer C of the laminated polyester film according to any one of (1) to (7), and 500 nm on the hard coat layer side. To 650 nm, an optical laminated film having an average waviness amplitude of spectral reflectance of 1.0% or less.
(9) The optical laminated film according to (8), wherein the hard coat layer has a refractive index of 1.43 to 1.60.

The laminated polyester film of the present invention relates to a laminated polyester film for a hard coat, has good processing suitability when laminating a hard coat layer, and is particularly excellent in reducing interference fringes and color unevenness and initial adhesion to the hard coat layer. Provided is a laminated polyester film excellent in moisture resistance and heat-and-heat adhesiveness in a high temperature and high humidity environment. ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the optical film excellent in the surface external appearance and abrasion resistance, and it becomes possible to aim at performance enhancement of optical films, such as a touchscreen.

It is the schematic of the coating device by the metaling wire bar which concerns on one embodiment of the lamination | stacking polyester film of this invention. FIG. 2 is an enlarged view of a metering wire bar portion of FIG. 1. It is the schematic of the coating device by the metaling wire bar which concerns on one embodiment of the lamination | stacking polyester film of this invention. FIG. 4 is an enlarged view of a metering wire bar portion of FIG. 3. 6 is a wavelength / wave reflectance graph showing the waviness amplitude of reflectance of a hard coat film.

The laminated polyester film of the present invention has a laminated film (C layer) on at least one surface of a layer (S layer) made of polyester as a base material layer, and has a spectral reflectance of 500 nm to 650 nm on the C layer side. The minimum value (Rmin) is preferably 4.0% or more and 6.0% or less, more preferably 4.5% or more and 5.7% or less, and 4.7% or more and 5.5% or less. It is particularly preferred. In addition, the change amount (Δr) of the spectral reflectance is preferably 1.0% or less, more preferably 0.7% or less, and still more preferably 0.4% or less. The optical properties of the C layer in the present invention are preferably such that the refractive index difference between the polyester film as the base material and the hard coat layer laminated thereon is small, and in order to suppress interference fringes The reflectance needs to be in the above range. When the spectral reflectance is out of the above range, the interference fringes when the optical laminated film is formed deteriorate. The method for achieving such a range is not particularly limited, but the refractive index of the C layer is continuously improved from the surface layer to the base material layer so that the refractive index is close to that of the base material layer and the hard coat layer. This is achieved by using the method.

In order to set the minimum value of the spectral reflectance at 500 nm to 650 nm on the C layer side within the above range, the C layer contains a polyester resin (A) and an acrylic resin (Q) having a fluorene skeleton and / or a naphthalene skeleton. The weight ratio (a) / (b) of the content (a) of the polyester resin (A) and the content (b) of the acrylic resin (Q) in the C layer is 40/60 or more and 95/5 or less. More preferably, it is more preferably 50/50 or more and 90/10 or less, and particularly preferably 60/40 or more and 80/20 or less. In order to make the change amount of the spectral reflectance within the above range, it is necessary to continuously improve the refractive index of the C layer from the surface layer to the base material layer, so the C layer is formed. The wetting tension of the polyester resin (A) is higher than the wetting tension of the acrylic resin (Q), and the difference is preferably 2 to 10 mN / m or less, more preferably 3 to 8 mN / m, and more preferably 4 to Particularly preferred is 6 mN / m. In the coating layer provided by applying a coating material consisting of polyester resin (A) and acrylic resin (Q) having a large difference in wetting tension on the base polyester film, due to the layer separation phenomenon due to the wetting tension difference of each resin The resin with low wetting tension on the surface side and the resin with high wetting tension on the substrate side mutually exclude each other, so that both layers are selectively arranged in two layers, and a clear interface is formed to completely form two layers There is a problem that becomes a structure. On the other hand, when an incomplete layer separation phenomenon occurs, such as when the difference in wetting tension is small, there is a problem that the layers are not separated at all. The laminated polyester film for optics of the present invention has a polyester resin (A) and an acrylic resin (Q), which are constituent components of the coating layer, within the above-mentioned range, so that the polyester resin ( A) The layer separation between the acrylic resin (Q) and the acrylic resin (Q) is appropriately advanced, and the composition ratio of the polyester resin (A) and the acrylic resin (Q) is continuously changed from the base material layer side to the hard coat layer side. Is possible. Further, by adding a fluorene skeleton and / or naphthalene skeleton to the polyester resin (A), it becomes possible to increase the refractive index to the same degree as the base polyester layer of the polyester resin (A), and the refractive index in the thickness direction in the C layer. Can be continuously changed. In addition, regarding the problem that the polyester resin (A) has a fluorene skeleton and / or a naphthalene skeleton, which is a conventional problem, the stretchable followability is lowered, the acrylic resin component can be formed by the configuration as described above. It is considered to play a role as a stretching aid, and is preferable because stretchability is greatly improved and coating uniformity is improved. As a preferable form of the polyester resin (A), the polyester resin (A) needs to be higher than the wetting tension of the acrylic resin (Q), and is an aqueous dispersion having a polyester skeleton having a hydrophilic group such as a carboxylic acid group or a sulfonic acid group. Further, as the hydrophilic group having a wetting tension difference with the acrylic resin (Q) within the above range, a carboxylic acid group is preferable, and when there are too many sulfonic acid groups, the surface tension difference with the acrylic resin (Q) is within the above range. May deviate. Moreover, as a preferable form of the acrylic resin (Q), it is necessary that it is lower than the wetting tension of the polyester resin (A), and when used as an aqueous coating agent, it is an aqueous dispersion of acrylic particles, that is, an emulsion. preferable. The layer C formed by applying the resin composition is expected to continuously improve the composition ratio of the acrylic resin (Q) from the base material layer to the hard coat layer. Since the acrylic resin (Q) is selectively present on the side, it is preferably equal to or close to the wetting tension of the acrylic resin (Q). The preferable wetting tension of the polyester resin (A) and the acrylic resin (Q) is 30 mN / m or more and 50 mN / m or less, and the wetting tension of any resin is 40 mN / m or less. It is preferable from the viewpoints of the moisture and heat resistant adhesion index and the adhesion index after boiling. The polyester resin (A) to be described later does not have a dicarboxylic acid component (Aa-3) having a sulfonate group, or is equal to or less than the amount of the dicarboxylic acid component (Aa) constituting the polyester resin (A). It can be easily achieved by having less than 1 mol%.

The layer thickness of the C layer is preferably in the range of 50 to 300 nm, more preferably in the range of 70 to 170 nm, in order to suppress interference fringes with the hard coat layer. When the thickness of the C layer is out of the above range, the C layer hardly forms the structure as described above, and the effect of suppressing the reflected light at the interface hardly occurs, and interference fringes are easily generated when the hard coat layer is provided. .

The laminated polyester film of the present invention can be made into a hard coat film by laminating a hard coat layer on the surface of the C layer. The initial adhesion index between the C layer surface and the hard coat layer, a temperature of 80 ° C., a relative humidity. It is preferable that the moisture and heat resistant adhesion index when left in a 90% constant temperature and humidity environment for 250 hours is 3 or more and 5 or less. Furthermore, it is more preferable that the adhesion index after boiling in 3 hours, which is a technique for evaluating more severe wet heat resistance, is 3 or more and 5 or less. The upper limit of the initial adhesion index, the heat-and-moisture resistant adhesion index, and the adhesion index after boiling is an evaluation index that does not peel at all. Adhesiveness of the laminated polyester film of the present invention and the hard coat layer in a wet heat environment is strongly demanded particularly for a hard coat film used for a portable device. In the application, condensation in a bathroom, a hot and humid area, a cold region, etc. Is required to have moisture and heat resistance. Until now, a heat-and-moisture resistance test for 250 hours to 500 hours has been carried out, but in order to shorten the inspection time and to obtain the ultimate heat-and-moisture resistance, a boiling test has recently been imposed. When the initial adhesion index is less than 3, it is not preferable because the moisture and heat resistant adhesion index and the adhesion index after boiling tend to be 3 or more. When the moisture and heat resistance index is 3 or more, it is possible to suppress a decrease in adhesion between the laminated polyester film and the hard coat layer even in a high temperature and high humidity environment, and it is preferably used in applications where moisture and heat resistance is required. be able to. In addition, when the adhesion index after boiling for 3 hours is 3 or more, the adhesiveness is maintained even in a severer high temperature and high humidity environment, so that it can be used in a very severe environment and is particularly preferable. The initial adhesion index is an index indicating the initial adhesion of the surface of the C layer with the hard coat layer. After the hard coat layer is laminated on the laminated polyester film of the present invention, the environmental load at high temperature and / or high humidity is reduced. It is the index | index which measured the adhesiveness of the lamination | stacking polyester film of this invention, and a hard-coat layer, without giving. The moisture and heat resistant adhesion index when left in a constant temperature and humidity environment at a temperature of 80 ° C. and a relative humidity of 90% for 250 hours is an index indicating the moisture and heat resistance of the C layer surface to the hard coat layer. The index is obtained by laminating a hard coat layer on a laminated polyester film and then measuring the adhesiveness between the laminated polyester film of the present invention and the hard coat layer by applying an environmental load of constant temperature and humidity at the high temperature and high humidity described above. The adhesion index after boiling after 3 hours is an index indicating the adhesiveness after boiling on the surface of the C layer with the hard coat layer. The hard coat layer is laminated on the laminated polyester film of the present invention, and 3% in boiling water. It is an index obtained by measuring the adhesion between the laminated polyester film of the present invention and the hard coat layer by applying an environmental load after immersion for a period of time.

As a method for setting the moisture and heat resistance adhesion index and the adhesion index after boiling to the above ranges, the C layer contains a polyester resin (A) having a fluorene skeleton and / or a naphthalene skeleton and an acrylic resin (Q), and a polyester resin ( A) does not have a dicarboxylic acid component (Aa-3) having a sulfonate group, or has less than 0.1 mol% with respect to the amount of the dicarboxylic acid component (Aa) constituting the polyester resin (A), etc. Is mentioned. Further, by adding a cross-linking agent to the C layer, it is possible to further improve the moist heat resistance index and the boiling index after boiling (details will be described later).

The laminated polyester film of the present invention needs to have a C layer having the above reflectance characteristics on a hard coat processed surface of a layer (S layer) to be a base material layer. In addition to improving the adhesiveness at the interface between the hard coat layer and the C layer by such a configuration, the light reflection at the interface between the hard coat layer and the laminated polyester film is suppressed, so that the rainbow color due to interference An optical laminated film with a reduced pattern can be obtained.

In order to make the spectral reflectance within the above range in the C layer of the laminated polyester film of the present invention, a layer in which the polyester resin (A) and the acrylic resin (Q) are mixed is formed, and the polyester resin (A) This can be achieved by improving the refractive index to the same level as the base material layer. Such a polyester resin (A) is achieved by having a fluorene skeleton and / or a naphthalene skeleton, and realizes a coating property by an in-line coating method at a high level and has a refractive index of the polyester resin (A) as a base material. In order to make it closer to the layer, it preferably has a fluorene skeleton. The polyester resin (A) having a fluorene skeleton can be obtained by adjusting the copolymerization amount of the dicarboxylic acid component (Aa-1) having a fluorene skeleton and the glycol component (Ab-1) having a fluorene skeleton. The polyester resin (A) having a fluorene skeleton refers to a polyester resin having an ester bond in the main chain or side chain, and can be obtained by the following method I) or II). Further, a method in which I) and II) are used together (a method in which a dicarboxylic acid component (Aa), a glycol component (Ab), and a component (Ac) are used as constituent components and these are subjected to a polycondensation reaction) may be used.
I) A method in which a dicarboxylic acid component (Aa) and a glycol component (Ab) are used as constituent components and both are subjected to a polycondensation reaction.
II) A method in which a component (Ac) having at least one alcoholic functional group (hydroxyl group) and at least one carboxyl group is used as a component and subjected to a polycondensation reaction.

In the method I), the dicarboxylic acid component (Aa) is classified into a dicarboxylic acid component (Aa-1) having a fluorene skeleton and a dicarboxylic acid component (Aa-2) having no fluorene skeleton. The glycol component (Ab) is classified into a glycol component (Ab-1) having a fluorene skeleton and a glycol component (Ab-2) having no fluorene skeleton. In the present invention, in order to introduce a fluorene skeleton into the polyester resin (A), a dicarboxylic acid component (Aa-1) having a fluorene skeleton and / or a glycol component (Ab-1) having a fluorene skeleton are copolymerized. It is preferable.

In the method II), the component (Ac) is classified into a component (Ac-1) having a fluorene skeleton and a component (Ac-2) having no fluorene skeleton. In the present invention, the component (Ac-1) having a fluorene skeleton is preferably copolymerized in order to introduce the fluorene skeleton into the polyester resin (A).

Hereinafter, the method when the method I) is used as the polyester resin (A) having a fluorene skeleton (hereinafter sometimes referred to as “fluorene copolymer resin (A)”) will be described in detail. The method II) Is the same as the method of I).

First, in the present invention, the dicarboxylic acid component (Aa) includes an ester-forming derivative obtained by alkylating a dicarboxylic acid. The dicarboxylic acid component (Aa) includes not only dicarboxylic acids in a narrow sense but also polyvalent carboxylic acids having 3 or more valences. The dicarboxylic acid component (Aa) includes an acid anhydride.

In the present invention, the glycol component (Aa) includes not only a narrowly-defined glycol but also a trivalent or higher polyol.

Examples of the dicarboxylic acid component (Aa-1) having a fluorene skeleton include 9,9-bis (t-butoxycarbonylmethyl) fluorene, 9,9-bis [2- (t-butoxycarbonyl) ethyl] fluorene, 9 , 9-bis [1- (t-butoxycarbonyl) ethyl] fluorene, 9,9-bis [2- (t-butoxycarbonyl) -1-cyclohexylethyl] fluorene, 9,9-bis [2- (t- Butoxycarbonyl) -1-phenylethyl] fluorene, 9,9-bis [1- (t-butoxycarbonyl) propyl] fluorene, 9,9-bis [2- (t-butoxycarbonyl) propyl] fluorene, 9,9 -Bis [2- (t-butoxycarbonyl) -1-methylethyl] fluorene, 9,9-bis [2- (t-butoxycarbonyl) -1-methylpropyl] fluorene, 9,9-bis [2- (t-butoxycarbonyl) butyl] fluorene, 9,9-bis [2- (t-butoxycarbonyl) -1-methylbutyl] fluorene, 9,9 -Bis [5- (t-butoxycarbonyl) pentyl] fluorene and the like are exemplified, but not limited thereto.

As the dicarboxylic acid component (Aa-2) having no fluorene skeleton, aromatic, aliphatic and alicyclic dicarboxylic acids having no fluorene skeleton and polyvalent carboxylic acids having 3 or more valences can be used. In the present invention, as the dicarboxylic acid component (Aa-2), terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6 -Naphthalenedicarboxylic acid, 1,2-bisphenoxyethane-p, p'-dicarboxylic acid, phenylindanedicarboxylic acid and the like can be used. Examples of the aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1, 4-Cyclohexanedicarboxylic acid and the like, and ester-forming derivatives thereof can be used.

As the glycol component (Ab-1) having a fluorene skeleton, 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-methylphenyl Fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-ethylphenyl] fluorene, 9 , 9-bis [4- (2-hydroxyethoxy) -3,5-diethylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-propylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-dipropylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-iso Lopyrphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-diisopropylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-n-butylphenyl] Fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-di-n-butylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) 10-3-isobutylphenyl Fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-diisobutylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3- (1-methylpropyl) Phenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-bis (1-methylpropyl) phenyl] fluorene, 9,9- Bis [4- (2-hydroxyethoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-diphenylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-benzylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-dibenzylphenyl] fluorene, 9,9-bis [4- (3- Hydroxypropoxy) phenyl] fluorene 9,9-bis [4- (4-hydroxybutoxy) phenyl] fluorene and the like, but are not limited thereto.
Examples of the glycol component (Ab-2) having no fluorene skeleton include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, , 5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethyl Hexane-1,3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5- Pentanediol, 2,2,4-trimethyl-1,6-hexanedio 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4'-thio Diphenol, bisphenol A, 4,4′-methylenediphenol, 4,4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4, 4′-isopropylidenephenol, 4,4′-isopropylidenebindiol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and the like can be used. It is not limited.

The copolymerization amount of the dicarboxylic acid component (Aa-1) having a fluorene skeleton in the polyester resin (A) having a fluorene skeleton is 40 mol% with respect to the amount of the dicarboxylic acid component (Aa) constituting the polyester resin (A). It is preferable that it is above, and more preferably 80 mol% or more. Although an upper limit is not specifically limited, It is preferable that it is 95 mol% or less.

Further, the copolymerization amount of the glycol component (Ab-1) having a fluorene skeleton in the polyester resin (A) having a fluorene skeleton is based on the amount of the glycol component (Ab) constituting the fluorene copolymerized polyester resin (A). It is preferable that it is 40 mol% or more, More preferably, it is 80 mol% or more. The upper limit is not particularly limited, but is particularly preferably 95 mol% or less.

When the copolymerization amount is less than 40 mol%, the polyester resin (A) is not sufficiently increased in refractive index, and interference fringes may occur when the hard coat layer is laminated. In addition, the upper limit is not particularly limited, but if the copolymerization ratio exceeds 95 mol%, the glass transition temperature of the polyester resin (A) becomes high, the stretchability becomes poor, the handling property is deteriorated, When the C layer is provided by using an in-line coating method to be described later, the stretchable followability becomes poor and a uniform C layer may not be provided.

The amount of copolymerization of the dicarboxylic acid component (Aa-1) having a fluorene skeleton and the glycol component (Ab-1) having a fluorene skeleton in the polyester resin (A) having a fluorene skeleton is such that the fluorene copolymer polyester resin (A) When the total of the substance amount of the dicarboxylic acid component (Aa) and the glycol component (Ab) constituting 100 is 100 mol%, it is preferably 20 mol% or more, more preferably 40 mol% or more. Although an upper limit is not specifically limited, It is preferable that it is 50 mol% or less.

In addition, with respect to the polyester resin (A) having a naphthalene skeleton, the dicarboxylic acid component and / or diol component having the fluorene skeleton has, for example, the naphthalene skeleton exemplified above. It can be obtained by the method.

The optical laminated film of the present invention can be produced by laminating the C layer by applying a water-based coating agent containing the polyester resin (A) to the surface of the S layer, followed by drying and heat treatment.

In order to obtain a water-based coating material containing the polyester resin (A), the polyester resin (A) is preferably water-soluble. In order to make the polyester resin (A) water-soluble, it is preferable to introduce a hydrophilic component such as a compound containing a carboxylate group or a compound containing a sulfonate group into the side chain of the polyester resin (A). The introduction of the hydrophilic component is achieved by using a dicarboxylic acid component (Aa-3) having a sulfonate group or a trivalent or higher polyvalent carboxylic acid component (Aa-4) as the dicarboxylic acid component (Aa). can do.

Examples of the dicarboxylic acid component (Aa-3) having a sulfonate group include sulfoisophthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7 dicarboxylic 5 [4-sulfophenoxy] isophthalic acid. Alkali metal salts, alkaline earth metal salts, and the like.

As the trivalent or higher polyvalent carboxylic acid component (Aa-4), an acid anhydride may be used in addition to the polyvalent carboxylic acid such as trimellitic acid. Specifically, 1,2,4,5-butanetetracarboxylic dianhydride (pyromellitic anhydride), 1,2,3,4-pentanetetracarboxylic dianhydride, 3,3 ′, 4, 4′-benzophenone tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 5- (2,5-di Oxotetrahydrofurfuryl) -3-cyclohexene-1,2-dicarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5, 6-naphthalenetetracarboxylic dianhydride, ethylene glycol bistrimellitic dianhydride, 2,2 ′, 3,3′-diphenyltetracarboxylic dianhydride, thiophene-2,3,4, - tetracarboxylic dianhydride, ethylene tetracarboxylic dianhydride, and the like.

However, in applications requiring resistance to moisture and heat, such as the recent flat panel display applications, when a sulfonate group is used as the hydrophilic component of the polyester resin (A), the hydrophilicity of the sulfonate group. Depending on the strength of the adhesive, the adhesion to the adherend in a high-temperature and high-humidity environment may be reduced.

Therefore, in the present invention, the polyester resin (A) does not have a dicarboxylic acid component (Aa-3) having a sulfonate group, or the amount of the dicarboxylic acid component (Aa) constituting the polyester resin (A). It is preferable to have less than 0.1 mol%. The amount of the dicarboxylic acid component (Aa-3) having a sulfonate group is more preferably 0.05 mol% or less, and particularly preferably not (0 mol%).

Therefore, in the present invention, when imparting hydrophilicity (water solubility) to the polyester resin (A), it is preferable to copolymerize a trivalent or higher polyvalent carboxylic acid component (Aa-4). By copolymerizing the trivalent or higher polyvalent carboxylic acid component (Aa-4), a carboxyl group can be introduced into the side chain of the polyester resin (A). Moreover, it is good also as a carboxylate group by neutralizing this carboxyl group with ammonia, sodium hydroxide, etc. By using a carboxylate group, the hydrophilicity can be further enhanced.

In the copolymerization of the polyvalent carboxylic acid component, a trivalent or higher polyvalent carboxylic acid anhydride (Aa-) is added to the polyester polyol (polyester oligomer) obtained by reacting the dicarboxylic acid component (Aa) and the glycol component (Ab). It is preferable to use a method of introducing a carboxyl group into the side chain of the polyester resin (A) by reacting 4). By using this method, a carboxyl group can be more efficiently introduced into the side chain of the polyester resin (A).

The substance amount (Aa-4m (mol)) of the polyvalent carboxylic acid anhydride (Aa-4) used at this time is equal to the substance amount (Aam (mol)) of the glycol component (Aa) used in the esterification reaction. It is preferable to set the substance amount to 0.5 to 1.0 times the difference (Aam−Abm (mol)) in the substance amount (Abm (mol)) of the dicarboxylic acid component. If it is less than 0.5 times, the adhesiveness of the prepared polyester resin coating film to the base material may be deteriorated in a high temperature and high humidity environment, and if it exceeds 1.0 times, the number average molecular weight of the polyester may not be increased. Yes, not preferred.

In addition, when water-solubilizing the polyester resin (A), a trace amount of a water-soluble organic solvent may be contained from the viewpoint of improving the storage stability and handling properties of the coating material. Examples of water-soluble organic solvents include water-soluble alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, water-soluble ketones such as acetone, and water-soluble ethers such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, carbitol, and butyl carbitol. Can be mentioned. These can be used alone or in combination. The content is preferably 10% or less, preferably 7% or less, more preferably 5% or less, based on the total amount of the coating material, from the viewpoint of explosion-proof properties and environmental pollution.

Next, an example of a method for producing the polyester resin (A) will be described. First, succinic acid or an ester-forming derivative thereof is used as a dicarboxylic acid component (Aa-2) having no fluorene skeleton, and 9,9-bis [4- (2-hydroxy) is used as a glycol component (Aa-1) having a fluorene skeleton. Ethoxy) phenyl] fluorene is subjected to an esterification reaction using a glycol component such as ethylene glycol as a glycol component (Ab-2) having no fluorene skeleton and a catalyst to obtain a polyester polyol. At this time, it is preferable that the addition amount of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and ethylene glycol is 1.01 to 2.0 times mol with respect to all dicarboxylic acid components. In order to polymerize a polyester polyol, since an excess glycol component is required with respect to the dicarboxylic acid component, 1.01 times mol or more of the glycol component is required with respect to the dicarboxylic acid component. However, if it exceeds 2.0 moles, the number average molecular weight distribution of the polyester resin (A) may not increase, which is not preferable.

Examples of the catalyst include titanium-based catalysts such as tetraisopropyl titanate and tetra-n-butyl titanate, antimony-based compounds such as antimony trioxide, germanium-based catalysts such as germanium oxide, and catalysts such as zinc acetate, manganese acetate, and dibutyltin oxide. Preferably, tetra-n-butyl titanate is used. The addition amount of the catalyst is preferably 10 to 1000 ppm with respect to the dicarboxylic acid component, and if it is less than 10 ppm, the reaction may not proceed. On the other hand, if it exceeds 1000 ppm, there is no advantage of shortening the reaction time. The esterification reaction at this time is not particularly limited by temperature and time, and may be carried out within a known range. For example, it is usually carried out at 160 to 240 ° C. for about 1 to 10 hours while distilling water or alcohol. Thereafter, the reaction system is gradually decompressed at about 200 to 260 ° C., and the reaction is carried out at 0.01 to 0.5 MPa for about 0.1 to 3 hours.

Next, polycarboxylic acid anhydride (Aa-4) is added to the obtained polyester polyol. If this reaction is carried out at 160 to 200 ° C. for about 1 to 10 hours, the desired polyester polyol can be obtained. It is done. At this time, the catalyst may be added to the same extent.

In the present invention, the intrinsic viscosity of the polyester resin (A) is not particularly limited, but it is preferably 0.3 dl / g or more from the viewpoint that the adhesion to an adherend such as a hard coat layer is good. More preferably, it is 0.35 dl / g or more, Most preferably, it is 0.4 dl / g or more. The upper limit of the intrinsic viscosity is not particularly limited, but is preferably 0.8 dl / g or less from the viewpoint of handling properties. The polyester resin (A) having the intended intrinsic viscosity can be obtained by adjusting melt polymerization conditions such as polymerization time and polymerization temperature.

The glass transition point (hereinafter sometimes abbreviated as Tg) of the polyester resin (A) is preferably 50 to 170 ° C., more preferably 50 to 150 ° C. If the Tg is less than 50 ° C., the heat-and-moisture resistance is likely to deteriorate, whereas if it exceeds 150 ° C., the C layer may not be uniformly applied in the in-line coating method described later. In order to make Tg within the above range, there is a method of using an aliphatic dicarboxylic acid component as the dicarboxylic acid component (Aa-2) other than the dicarboxylic acid component having a fluorene skeleton of the fluorene copolymerized polyester resin (A). .

The acid value of the polyester resin (A) is preferably 20 mgKOH / g or more, more preferably 30 mgKOH / g or more. By setting the acid value within the above range, it is possible to improve the adhesiveness, particularly the wet heat resistant adhesiveness. In order to make the acid value within the above range, it can be obtained by adjusting the amount of the polyvalent carboxylic acid anhydride (Aa-4) reacted with the polyester polyol during the polymerization of the fluorene copolymerized polyester resin (A).

The acrylic resin (Q) is a monomer component constituting the acrylic resin, for example, alkyl acrylate, alkyl methacrylate (the alkyl group is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, etc.) T-butyl group, 2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.), 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, Hydroxy group-containing monomers such as 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide Amide group-containing monomers such as N, N-dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide, N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate, etc. Amino group-containing monomers, glycidyl acrylate, epoxy group-containing monomers such as glycidyl methacrylate, monomers such as acrylic acid, methacrylic acid and salts thereof (lithium salt, sodium salt, potassium salt, etc.) or monomers containing such salts These may be (co) polymerized using one or more of them. Furthermore, other types of monomers other than those described above can be used in combination. Although it does not specifically limit as another kind of monomer which can be used here, For example, epoxy group containing monomers, such as allyl glycidyl ether, styrene sulfonic acid, vinyl sulfonic acid, and their salts (lithium salt, sodium salt, potassium salt, ammonium salt) Monomers containing sulfonic acid groups or salts thereof, such as crotonic acid, itaconic acid, maleic acid, fumaric acid and their salts (lithium salts, sodium salts, potassium salts, ammonium salts, etc.) or the like Monomers containing salts, monomers containing acid anhydrides such as maleic anhydride and itaconic anhydride, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl malein Monoesters, alkyl fumaric acid monoester, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoester, vinylidene chloride, vinyl acetate, etc. can be used vinyl chloride.

Also, a modified acrylic copolymer, for example, a block copolymer modified with polyester, urethane, epoxy or the like, a graft copolymer and the like can be included. The glass transition point (Tg) of the acrylic resin (Q) used for the laminated film is not particularly limited, but is preferably 0 to 90 ° C., more preferably 10 to 80 ° C. When the acrylic resin (Q) having a low Tg is used, the heat-resistant adhesion tends to be inferior, and conversely, when it is too high, the film forming property may be inferior. Further, the molecular weight of the acrylic resin (Q) is preferably 100,000 or more, more preferably 300,000 or more from the viewpoint of adhesiveness.

More preferable acrylic resin (Q) used for the C layer is selected from methyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-methylol acrylamide, glycidyl methacrylate, and acrylic acid (co-polymer). ) Polymers can be mentioned. It is preferable to use an aqueous acrylic resin (Q) obtained by dissolving, emulsifying, or suspending the acrylic resin (Q) in water as a raw material for the C layer from the viewpoint of preventing environmental pollution and explosion-proof during application. Such an aqueous acrylic resin (Q) is a copolymer of a monomer having a hydrophilic group (such as acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and its salt) and the above-mentioned monomers, a reactive emulsifier or a surfactant. Can be prepared by methods such as emulsion polymerization, suspension polymerization, and soap-free polymerization. The mode of the acrylic resin (Q) used for the laminated film is not particularly limited, but is preferably an aqueous dispersion having a particle size of 100 nm, that is, an emulsion, and further an aqueous dispersion having a particle size of 60 nm or less. It is more preferable that If the acrylic resin (Q) is completely dissolved in water, the layer separation action with the polyester resin (A) is reduced, and an emulsion having a particle size larger than 100 nm increases the haze of the film and is not suitable as an optical laminated film. Appropriate.

In addition, it is preferable that the C layer contains a crosslinking agent (B) in addition to the polyester resin (A) and the acrylic resin (Q) from the viewpoint of improving the heat and heat resistance. When the cross-linking agent (B) is contained in the C layer, the total of the polyester resin (A) and acrylic resin (Q) and the cross-linking agent (B) should be adjusted to 90% by weight or more with respect to the entire C layer. Is preferred. By setting the total content in the above range, it is possible to achieve a high refractive index of the C layer. In addition, although the upper limit of total content is not specifically limited, 100 weight% becomes a substantial upper limit.

In the present invention, as the crosslinking agent (B), by using one or more crosslinking agents selected from the group consisting of melamine crosslinking agents, oxazoline crosslinking agents, and carbodiimide crosslinking agents, a fluorene copolymer polyester resin ( It is preferable because improvement in wet heat resistance due to deactivation of the carboxyl groups of A) and acrylic resin (Q) and improvement in wet heat resistance due to the progress of the self-crosslinking reaction of the crosslinking agent (B) are observed. Moreover, content in the C layer of crosslinking agents (B), such as a melamine type, an oxazoline type, a carbodiimide type, is not specifically limited, You may use 2 or more types of crosslinking agents. In particular, when all melamine-based, oxazoline-based, and carbodiimide-based crosslinking agents are contained, the adhesion index after boiling is remarkably improved, which is particularly preferable. Although the details of the mechanism for this phenomenon are unknown, the crosslinkable reactive groups of the polyester resin (A) and acrylic resin (C) and the above three types of crosslinkers have no partial bias, and the entire C layer is sufficient. It is considered that the moisture and heat resistant adhesiveness is improved by the crosslinking reaction.

The melamine-based crosslinking agent used in the present invention is not particularly limited, but is partially or completely etherified by reacting melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, or a methylolated melamine with a lower alcohol. A compound, a mixture thereof, and the like can be used. The melamine-based crosslinking agent may be a monomer, a condensate composed of a dimer or higher polymer, or a mixture thereof. As the lower alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. The functional group has an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, and an imino group type methylated melamine resin, a methylol group type melamine resin, or a methylol group type. Examples include methylated melamine resins and fully alkyl type methylated melamine resins. Of these, methylolated melamine resins are most preferred. Furthermore, an acidic catalyst such as p-toluenesulfonic acid may be used to accelerate the thermal curing of the melamine-based crosslinking agent.

Further, the oxazoline-based crosslinking agent used in the present invention is not particularly limited as long as it has an oxazoline group as a functional group in the compound, but includes at least one monomer containing an oxazoline group, And what consists of an oxazoline group containing copolymer obtained by copolymerizing at least 1 type of another monomer is preferable.

Examples of the monomer containing an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-Isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be used, and one or a mixture of two or more thereof can also be used. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

In the oxazoline-based cross-linking agent, the at least one other monomer used for the monomer containing the oxazoline group is not particularly limited as long as it is a monomer copolymerizable with the monomer containing the oxazoline group. Acrylates or methacrylates such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, etc. Acids, unsaturated carboxylic acids such as methacrylic acid, itaconic acid and maleic acid, unsaturated nitriles such as acrylonitrile and methacrylonitrile, acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylate Unsaturated amides such as amides, vinyl esters such as vinyl acetate and vinyl propionate, vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, olefins such as ethylene and propylene, vinyl chloride, vinylidene chloride and vinyl fluoride. Halogen-α, β-unsaturated monomers, α, β-unsaturated aromatic monomers such as styrene, α-methylstyrene, etc. can be used, and these should be used alone or in a mixture of two or more. You can also.

In addition, the carbodiimide-based crosslinking agent used in the present invention is particularly a compound having one or two or more cyanamide groups in the molecule having a carbodiimide group or a tautomeric relationship as a functional group in the compound. It is not limited. Specific examples of such carbodiimide compounds include dicyclohexylmethane carbodiimide, dicyclohexyl carbodiimide, tetramethylxylylene carbodiimide, urea-modified carbodiimide, and the like, and these may be used alone or as a mixture of two or more. .
The resin constituting the C layer and the crosslinking agent in the present invention can be mixed and used at an arbitrary ratio, but the content (c) of the crosslinking agent (B) is 100% by weight of the entire C layer. The addition of 5 wt% or more and 50 wt% or less is preferable from the viewpoint of improving the adhesion under normal conditions, more preferably 10 to 40 wt%, and particularly preferably 15 to 35 wt%. When the addition amount of the cross-linking agent is less than 5% by weight, the effect of addition is small, and the heat-and-moisture resistance to the hard coat layer is lowered, resulting in poor practicality. On the other hand, when it exceeds 50% by weight, the refractive index of the entire C layer is lowered, so that interference fringes when used as a base material for an optical hard coat film are deteriorated. In particular, when using an oxazoline-based cross-linking agent and a carbodiimide-based cross-linking agent other than melamine-based cross-linking agents, the heat-and-moisture resistance is remarkably improved. In some cases, it is necessary to adjust the refractive index on the resin side.

As a preferred embodiment of the present invention, it is more preferable to incorporate fine particles in the C layer because the slipperiness and blocking resistance are improved. The fine particles to be incorporated are not particularly limited, but inorganic particles such as colloidal silica, titanium oxide, aluminum oxide, zirconium oxide, calcium carbonate, carbon black, zeolite particles, acrylic particles, silicone particles, polyimide particles, “Teflon (registered trademark) ) "Organic particles such as particles, cross-linked polyester particles, cross-linked polystyrene particles, cross-linked polymer particles, and core-shell particles may be used. Any of these particles may be used or a plurality of types may be used in combination.

The number average primary particle diameter of these particles is preferably in the range of 0.01 to 0.6 μm. Here, the average primary particle diameter is an average of the particle diameters of primary particles defined as particles generated by the growth of a single crystal nucleus in JIS-H7008 (2002). The particle diameter of the primary particles (hereinafter referred to as the primary particle diameter) is the average value of the major axis and the minor axis. For the measurement of such average primary particle size, the sample was observed at a magnification of 50,000 times using a scanning electron microscope (SEM) according to JIS-H7804 (2005), and the major axis of each primary particle was used using photographs. The average primary particle diameter can be determined from the number average value obtained by measuring the primary diameter by measuring the average diameter and determining the primary particle diameter by average. If the average primary particle size of the particles is less than 0.01 μm, the particles may aggregate and deteriorate the haze of the C layer. Conversely, if it exceeds 0.6 μm, The effect of blocking resistance is difficult to obtain, and depending on the thickness of the C layer, particles may fall off. The average primary particle size of the particles is more preferably in the range of 20 to 500 nm, still more preferably in the range of 20 to 400 nm. The particles may be monodispersed particles or aggregated particles in which a plurality of particles are aggregated. In some cases, a plurality of types of particles having different average primary particle sizes may be used in combination. The addition amount of the particles should be appropriately adjusted and designed according to the thickness of the C layer, the resin composition, the average primary particle size, the required slipperiness and use, etc., but is 0 for 100 parts by weight of the entire C layer. It is preferably in the range of 0.05 to 8 parts by weight, more preferably in the range of 0.1 to 5 parts by weight.

Furthermore, in the layer C of the laminated polyester film of the present invention, various additives, for example, an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, within a range not inhibiting the effects of the present invention, Pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents and the like may be blended.

In the present invention, examples of the method for obtaining the optical laminated film having the S layer and the C layer include a method of laminating the C layer on the S layer. Among these, a method of coating (coating) a coating agent constituting the C layer on the S layer and laminating is preferable. As such a coating method, there is a method in which coating is performed in a process separate from the manufacturing process of the S layer, a so-called offline coating method, and a laminated polyester film in which coating is performed during the manufacturing process of the S layer and the C layer is laminated on the S layer. There is a so-called in-line coating method that obtains at once. However, in the present invention, it is preferable to adopt an in-line coating method from the viewpoint of cost and uniformity of the coating thickness, and the solvent of the coating liquid used in that case should be an aqueous system from the viewpoint of environmental pollution and explosion-proof properties. Most preferred.

In carrying out the present invention, the application method of the aqueous coating agent is not particularly limited. For example, a reverse coating method, a spray coating method, a bar coating method, a gravure coating method, a rod coating method, a die coating method, etc. Although it can be used, in order to reduce the thickness unevenness of the C layer, a gravure coating method and a metalling wire bar coating method are preferable, and a metaling wire bar coating method is particularly preferable.

When using the metalling wire bar coating method, it is preferable to apply the coating agent uniformly with a bar, but the coating appearance may be deteriorated if the coating liquid scraped off by the bar is poor. It is preferable to install covers as illustrated in FIGS. 1 and 2 upstream and downstream of the metering wire bar in order to smoothly remove the scraped coating liquid and prevent defects due to splashing. The clearance (X) between the metalling wire bar and the upstream cover is 0.7 to 2.0 mm, and the clearance (Y) between the metalling wire bar and the downstream cover is 0.3 to 0 narrower than (X). It is preferable to set the thickness to 7 mm because it can ensure liquid drainage and prevent defects due to liquid splashing. If the gap (X) between the metering wire bar and the upstream cover is less than 0.7 mm, the liquid-removing property will deteriorate, so the thickness unevenness of the C layer may deteriorate. This is not preferable because the coating defects due to the coating increase. Further, when the gap (Y) between the metering wire bar and the downstream cover is less than 0.3 mm, the liquid drainage from the downstream side is deteriorated, and therefore the thickness unevenness of the C layer may be deteriorated. If it exceeds 7 mm, coating defects due to splashing increase, which is not preferable. By making the gap (X) between the metering wire bar and the upstream cover larger than the gap (Y) between the metering wire bar and the downstream cover, it is possible to improve liquid drainage from the upstream side. 3 and 4, the coating liquid is directly supplied to the lower part of the metalling wire bar, the lower part of the bar is filled with the coating liquid, and the lower part of the metalling wire bar is filled with the coating liquid. In the case of using the method of applying to the film by using the rotation, it is possible to apply with a small supply amount, and the thickness unevenness of the C layer is stabilized, which is more preferable. The thickness unevenness of the C layer can use the thickness tolerance of the C layer as an index, and the thickness tolerance of the C layer is preferably 10 nm or less.

In the present invention, before applying the aqueous coating agent, the surface of the S layer as the base material layer is subjected to corona discharge treatment or the like, and the wetting tension of the surface is preferably 47 mN / m or more, more preferably 50 mN / m. The above is preferable. This is because the adhesion between the C layer and the S layer is improved and the coating property is also improved.

The polyester constituting the layer (S layer) using the polyester used as the base material layer is a general term for polymers having an ester bond as the main bond chain of the main chain. Preferred polyesters include ethylene terephthalate, At least one component selected from ethylene-2,6-naphthalate, butylene terephthalate, ethylene-α, β-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate and the like as a main component Can be used. These constituent components may be used singly or in combination of two or more. Among them, it is particularly preferable to use a polyester having ethylene terephthalate as a main constituent in view of quality, economy and the like. In applications where heat acts on the substrate, polyethylene-2,6-naphthalate having excellent heat resistance and rigidity is more preferable.

Further, these polyesters may be further partially copolymerized with other dicarboxylic acid components and diol components, preferably 20 mol% or less.

The intrinsic viscosity (measured in o-chlorophenol at 25 ° C. according to JIS K7367 (2000)) is preferably 0.4 to 1.2 dl / g, more preferably 0.5 to 0.8 dl / g. Is within the range.

Further, in this polyester, various additives such as antioxidants, heat stabilizers, weathering stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents. An agent, a nucleating agent, a crosslinking agent, etc. may be added to such an extent that the properties are not deteriorated.

In particular, it is preferable to contain an ultraviolet absorber in the polyester film in order to impart ultraviolet cutting ability. Preferred examples of the ultraviolet absorber include salicylic acid compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, benzoxazinone compounds, cyclic imino ester compounds, and the like. M + P and M / P of the polyester described later (M is the concentration of the catalytic metal element remaining in the film (mmol%), P is the concentration of the phosphorus element remaining in the film (mmol%). ) A benzoxazinone-based compound is most preferable from the viewpoint of the expression of the effect of improving dispersibility by controlling wrinkles. These compounds can be used alone or in combination of two or more. Further, stabilizers such as H A L S and antioxidants can be used in combination, and it is particularly preferable to use a phosphorus-based antioxidant in combination.

Examples of the benzotriazole-based compound include 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol and 2- (2H-benzotriazole-2). -Yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl) -4-methylphenol, 2- (2H-benzotriazol-2-yl) ) -4,6-di-t-butylphenol, 2- (2H-benzotriazol-2-yl) -4,6-di-t-amylphenol, 2- (2H-benzotriazol-2-yl) -4 -T-butylphenol, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3) , Can be exemplified 5'-di -t- butyl-phenyl) -5-chloro-benzotriazole, or the like.

Examples of benzophenone compounds include 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4' -Tetrahydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid and the like.

Examples of the benzoxazinone compounds include 2-p-nitrophenyl-3,1-benzoxazin-4-one, 2- (p-benzoylphenyl) -3,1-benzoxazin-4-one, 2- ( 2-naphthyl) -3,1-benzoxazin-4-one, 2,2'-p-phenylenebis (3,1-benzoxazin-4-one), 2,2 '-(2,6-naphthylene) Examples thereof include bis (3,1-benzoxazin-4-one).

In the laminated polyester film of the present invention, the transmittance at a wavelength of 380 nm is preferably 5.0% or less, and the transmittance at 380 nm is more preferably 3.0% or less. When this is applied to a display member that requires display substrate protection, the transmittance at a wavelength of 380 nm from the viewpoint of the ultraviolet protection function of other materials and other compounds, and the wavelength at a wavelength of 380 nm from the viewpoint of luminance and light transmittance. The transmittance is defined in the above range, and the total light transmittance, haze, and b value are also controlled while controlling the transmittance within the above range, such as LCD, electronic paper, EL display, plasma display, projection TV member, etc. It can be suitably used as various display members.
In addition, the addition of fine particles often reduces the properties relating to transparency such as light transmittance and haze. When added, the particle diameter is as small as possible, and preferably less than about ¼ of the visible light wavelength where scattering is less likely to occur. What has a particle diameter is preferable and it is preferable that the addition amount is also a trace amount.

In the present invention, it is preferable to use a biaxially oriented polyester film as the S layer using the polyester. Here, “biaxial orientation” refers to a pattern showing a biaxial orientation pattern by wide-angle X-ray diffraction. A biaxially oriented polyester film is generally obtained by stretching an unstretched polyester sheet about 2.5 to 5 times in the longitudinal direction and width direction of the sheet, and then applying heat treatment to complete crystal orientation. Can do.

Further, the S layer used in the present invention may be a laminated structure in which the S layer itself is two or more layers. As the laminated structure, for example, a composite film having an inner layer portion and a surface layer portion, which is substantially free of particles in the inner layer portion, and provided with a layer containing particles in the surface layer portion. The inner layer portion and the surface layer portion may be chemically different polymers or the same type of polymers. In the display application which is the main purpose of the present invention, it is preferable from the viewpoint of optical properties such as transparency that the S layer does not contain particles.

The layer thickness of the S layer serving as the substrate is not particularly limited and is appropriately selected depending on the application, but is usually 10 to 500 μm, preferably 20 to 300 μm.

Next, the production method of the laminated polyester film of the present invention will be described by taking as an example the case of using a polyethylene terephthalate (hereinafter abbreviated as PET) film as the S layer, but is not limited thereto.

The PET pellets having an intrinsic viscosity of 0.5 to 0.8 dl / g constituting the S layer are vacuum-dried, then supplied to an extruder, melted at 260 to 300 ° C., extruded into a sheet form from a T-shaped die, and electrostatically The film was wound around a mirror casting drum having a surface temperature of 10 to 60 ° C. using an applied casting method, and cooled and solidified to produce an unstretched PET film. This unstretched film is stretched 2.5 to 5 times between rolls heated to 70 to 100 ° C. in the longitudinal direction (referring to the traveling direction of the film and also referred to as “longitudinal direction”). At least one surface of this film is subjected to corona discharge treatment in air, the surface has a wetting tension of 47 mN / m or more, and an aqueous coating material constituting the C layer is applied to the treated surface. The coated optical laminated film is held with a clip and guided to a drying zone, dried at a temperature lower than Tg of the polyester resin (A) constituting the S layer, then raised to a temperature equal to or higher than Tg, and again in the vicinity of Tg. And then continuously stretched by 2.5 to 5 times in the transverse direction (referred to as a direction perpendicular to the film traveling direction) in a heating zone at 70 to 150 ° C., followed by 200 to Heat treatment is performed in a heating zone at 240 ° C. for 5 to 40 seconds, and a polyester film in which a C layer is laminated on an S layer having crystal orientation completed is obtained through a cooling zone at 100 to 200 ° C. During the heat treatment, a 3 to 12% relaxation treatment may be performed as necessary. Biaxial stretching may be longitudinal, transverse sequential stretching, or simultaneous biaxial stretching, and may be re-stretched in either the longitudinal or transverse direction after longitudinal and transverse stretching.
The laminated polyester film of the present invention has a heat shrinkage rate of 0.0 to 0.7% in the width direction (TD) at 120 ° C. in order to obtain high processing suitability for a hard coat, and the width direction (TD) at 190 ° C. ) In the width direction (TD) at 120 ° C. is preferably 0.2 to 0.5%, and at 190 ° C. The thermal shrinkage in the width direction (TD) is preferably −0.2 to 0.3%. By setting the heat shrinkage rate within the range of 120 ° C., film curling after hard coating can be prevented. In addition, the thermal shrinkage rate in the width direction (TD) at 190 ° C. is set to a value lower than 120 ° C., which is the above range, in consideration of curling properties during long-term durability. Since it can prevent, it is preferable. This is thought to be due to the fact that the distortion due to the entanglement of amorphous molecular chains that cannot be solved in a short time is gradually released over time. By keeping the state low, it is possible to maintain the temporal stability. In order to make the heat shrinkage rate within the above range, a relaxation treatment of 4 to 12% is performed in the heating zone of 200 to 240 ° C. in the transverse stretching step, and again 0.1 to 3.0% in the cooling zone of 100 to 200 ° C. This can be achieved by performing a fine stretching.
The thickness of the laminated polyester film is not particularly limited, but preferably 3 to 300 μm. The coating material used in this case is preferably an aqueous coating material from the viewpoint of environmental pollution and explosion-proof properties.

The surface of the layer C of the laminated polyester film according to one aspect of the present invention thus obtained is an initial stage with the hard coat layer using the actinic radiation curable resin because the acrylic resin (Q) is localized. Excellent adhesion, and C layer contains fluorene copolymer polyester resin (A), which is a high refractive index resin, so that the difference in refractive index from the substrate layer can be reduced, and when a hard coat layer is provided on the surface of C layer The suppression of interference fringes can be made excellent. Further, when the dicarboxylic acid component (Aa-3) having a sulfonate group is not included as a hydrophilic component, it is possible to suppress the decrease in adhesiveness with the hard coat layer in a high temperature and high humidity environment to the utmost limit. Further, by adding the crosslinking agent (B), the coating property is improved, and not only a coating film (C layer) with less coating unevenness is obtained, but also the adhesion to the hard coat layer is made stronger. it can. Such a laminated polyester film includes a hard coat film, an antireflection film further provided with an antireflection layer, an optical laminated film for a touch panel provided with a conductive metal oxide layer, an optical laminated film for electronic paper, and the like. It can be used as an optical laminated film for display members.

Next, an optical laminated film in which a hard coat layer is provided on the laminated polyester film of the present invention will be described.

In the present invention, the material constituting the hard coat layer is not particularly limited as long as it transmits visible light, but preferably has a high light transmittance. Examples of materials used include acrylic resins, polycarbonate resins, vinyl chloride resins, polyester resins, urethane resins, and actinic radiation curable resins. In particular, acrylic resins, urethane resins, and actinic radiation curable resins can be suitably used in terms of scratch resistance, productivity, and the like.

The actinic radiation curable resin used as a constituent component of the hard coat layer according to the present invention includes, for example, pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) as monomer components constituting the actinic radiation curable resin. Acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, bis (meth) Chloroylthiophenyl) sulfide, 2,4-dibromophenyl (meth) acrylate, 2,3,5-tribromophenyl (meth) acrylate, 2,2-bis (4- (meth) acryloyloxypheny) ) Propane, 2,2-bis (4- (meth) acryloyloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) ) Acryloylpentaethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxyethoxy-3,5-dibromophenyl) propane, 2,2-bis (4- (meth) acryloyloxydiethoxy-3, 5-dibromophenyl) propane, 2,2-bis (4- (meth) acryloyloxypentaethoxy-3,5-dibromophenyl) propane, 2,2-bis (4- (meth) acryloyloxyethoxy-3,5 -Dimethylphenyl) propane, 2,2-bis (4- (meth) acryloyloxyethoxy-3-phenyl Enyl) propane, bis (4- (meth) acryloyloxyphenyl) sulfone, bis (4- (meth) acryloyloxyethoxyphenyl) sulfone, bis (4- (meth) acryloyloxypentaethoxyphenyl) sulfone, bis (4- (Meth) acryloyloxyethoxy-3-phenylphenyl) sulfone, bis (4- (meth) acryloyloxyethoxy-3,5-dimethylphenyl) sulfone, bis (4- (meth) acryloyloxyphenyl) sulfide, bis (4 -(Meth) acryloyloxyethoxyphenyl) sulfide, bis (4- (meth) acryloyloxypentaethoxyphenyl) sulfide, bis (4- (meth) acryloyloxyethoxy-3-phenylphenyl) sulfide, bis (4- (meta Acu Use of polyfunctional (meth) acrylic compounds such as liloyloxyethoxy-3,5-dimethylphenyl) sulfide, di ((meth) acryloyloxyethoxy) phosphate, tri ((meth) acryloyloxyethoxy) phosphate These can be used alone or in combination of two or more.

In addition to these polyfunctional (meth) acrylic compounds, styrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, divinylbenzene are used to control the hardness, transparency, strength, refractive index, etc. of actinic radiation curable resins. , Vinyl toluene, 1-vinyl naphthalene, 2-vinyl naphthalene, N-vinyl pyrrolidone, phenyl (meth) acrylate, benzyl (meth) acrylate, biphenyl (meth) acrylate, diallyl phthalate, dimethallyl phthalate, diallyl biphenylate, or barium A reaction product of a metal such as lead, antimony, titanium, tin, or zinc and (meth) acrylic acid can be used. These may be used alone or in combination of two or more.

In the present invention, the description “(meth) acrylic compound” is an abbreviation of “methacrylic compound and acrylic compound”, and the same applies to other compounds.

As a method for curing the actinic radiation curable resin in the present invention, for example, a method of irradiating with ultraviolet rays can be used. In this case, about 0.01 to 10 parts by weight of photopolymerization is started with respect to the compound. It is desirable to add an agent.

The actinic radiation curable resin used in the present invention is not limited to isopropyl alcohol, ethyl acetate, methyl ethyl ketone, etc. within the range that does not impair the effects of the present invention for the purpose of improving workability during coating and controlling the coating film thickness. An organic solvent can be blended.

In the present invention, active rays mean electromagnetic waves that polymerize acrylic vinyl groups such as ultraviolet rays, electron beams, and radiation (α rays, β rays, γ rays, etc.), and practically, ultraviolet rays are simple and preferable. . As the ultraviolet ray source, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, or the like can be used. The electron beam method is advantageous in that the apparatus is expensive and requires operation under an inert gas, but it does not need to contain a photopolymerization initiator or a photosensitizer.

The refractive index of the hard coat layer in the present invention can be adjusted so that the refractive index difference at the interface with the surface of the C layer is small, thereby suppressing light reflection that causes interference fringes. The refractive index of such a hard coat layer is preferably 1.43 to 1.60, and more preferably 1.45 to 1.55. The thickness of the hard coat layer should be appropriately adjusted and designed according to the intended use and is not particularly limited, but is usually 1 to 10 μm, preferably 2 to 5 μm. When the thickness of the hard coat layer is within such a preferable range, the hard coat properties are sufficiently expressed, and on the other hand, the film is not curled due to shrinkage at the time of curing of the hard coat layer.

In the present invention, it is preferable that an antireflection layer for suppressing flickering is provided on the surface of the hard coat layer, or an antifouling treatment for preventing contamination is performed.

In particular, in the present invention, it is particularly preferable that a high refractive index hard coat layer and a low refractive index layer, which are antireflection layers, are laminated in this order on the hard coat layer and used as an antireflection film.
The antireflection layer is not particularly limited, but can be formed by laminating a low refractive index compound or sputtering or vapor deposition of an inorganic compound such as magnesium fluoride or silicon oxide. As for the antifouling treatment, an antifouling treatment with a silicone resin, a fluorine resin or the like can be performed.
The interference fringes generated at each interface of the optical laminated film as described above can be reduced by reducing the waviness amplitude of the spectral reflectance spectrum on the hard coat layer side. In the optical film of the present invention, it is more preferable to use a laminated structure of a base film and a hard coat layer described below because an optical laminated film without interference fringes can be formed.

The average waviness amplitude of the reflectance at a wavelength of 500 to 600 nm described in the present invention is measured as follows. First, the surface on which the hard coat layer of the optical laminated film is laminated is used as the measurement surface, and the opposite surface is a black glossy tape (Yamato Co., Ltd.) having a width of 50 mm so that the average visible light transmittance at a wavelength of 500 to 600 nm is 5% or less. ) Made of vinyl tape No. 200-50-21: black) is used as a measurement sample so that air bubbles are not caught. FIG. 5 shows the results observed when the measurement surface of the optical laminated film is measured with a spectrophotometer at an incident angle of 5 degrees from the measurement surface. In FIG. 5, the curve represents the relationship between the wavelength and the measured reflectance. In the reflectivity, undulation at a wavelength of 500 to 650 nm, that is, a maximal value in a calculus meaning that the reflectivity fluctuates up and down as the wavelength changes (first derivative = 0, second derivative <0). And the minimum value (primary differential coefficient = 0, secondary differential coefficient> 0) is defined as the waviness amplitude. As shown in FIG. 5, the line (peak line) connecting the peaks (maximum points) of the ridges of the swell of the reflectance at a wavelength of 500 to 600 nm and the line (valley lines) connecting the valleys (minimum points) of the undulations. The difference between the two line graphs of reflectance, that is, the waviness amplitude, 11 sample points at 10 nm intervals including the boundary points (500 nm, 600 nm) (wavelength is (500 + 10 × i (i = 0 to 10)) The value obtained by averaging these 11 values is defined as the average undulation amplitude. In the optical laminated film of the present invention, the average waviness amplitude of the reflectance on the hard coat layer side is preferably 1.0% or less. The average waviness amplitude is more preferably 0.7% or less, and still more preferably 0.4% or less. When the average waviness amplitude of the reflectance on the hard coat layer side is larger than 1.0%, an iris pattern is generated when light having a wavelength intensity distribution such as a fluorescent lamp is reflected, and visibility is deteriorated.

[Characteristic measurement method and effect evaluation method]
The characteristic measuring method and the effect evaluating method in the present invention are as follows.

(1) Layer thickness of layer C Three points of the center and both ends in the width direction of the product roll were sampled at three locations every 1 m in the flow direction, and a total of nine points were used as measurement samples. The cross section of the optical laminated film is cut into ultra-thin sections, and the cross-sectional structure can be visually observed with a transmission electron microscope (TEM) by RuO ₄ staining, OsO ₄ staining, or by staining both sections by double staining. The thickness of the C layer was measured from the cross-sectional photograph. The measured value was an average value and tolerance of 9 points. The thickness tolerance of the C layer is the maximum and minimum of the measured values obtained by sampling three points at the center and both ends in the width direction of the product roll at three points every 1 m in the flow direction, and using a total of nine points as measurement samples. The difference in values. Although the width | variety of a product roll is not specifically limited, It will be 300 mm or more from a normal film forming apparatus, and it is about 1.5 m at the maximum.
・ Measurement device: Transmission electron microscope (H-7100FA type, manufactured by Hitachi, Ltd.)
・ Measurement conditions: Acceleration voltage 100kV
-Sample preparation: frozen ultrathin section method-Magnification: 300,000 times.

(2) Wetting tension On a 188 μm thick polyethylene terephthalate (PET) film (Toray Industries, Inc. “Lumirror” 188T60) obtained by cutting the prepared aqueous dispersion into A4 size, using a # 14 (Mill) bar coater It apply | coated on PET film so that the coating film thickness before drying might be set to about 32 micrometers. Thereafter, it was dried by heating at 60 ° C. for 30 minutes. The wetting tension of the film surface on the coated surface side was measured according to the method described in JIS-K-6768-1999.

(3) Spectral reflectance The film sheet cut into A4 cut size with the film flow direction as the long side (longitudinal direction) was divided into 3 parts each in length and width, and a total of 9 points were used as measurement samples. Spectral reflectance is measured by measuring the length of the sample and the tape so that air bubbles are not caught on the back side of the measurement surface with a black glossy tape of 50 mm width (vinyl tape No. 200-50-21 made by Yamato Co., Ltd.). After bonding together in the direction, the sample was cut into about 4 cm square sample pieces, and the spectral reflectance at an incident angle of 5 ° was measured with a spectrophotometer (UV2450, manufactured by Shimadzu Corporation). The direction in which the sample was set in the measuring instrument was aligned with the longitudinal direction of the sample in the front-rear direction toward the front of the measuring instrument. In order to standardize the reflectance, an attached Al ₂ O ₃ plate was used as a standard reflecting plate. The average value of 9 points was used for the measured value. Further, the amount of change in reflectance at a wavelength of 500 nm to 650 nm can be obtained from the difference between the maximum value and the minimum value of the reflectance in the wavelength region.

(4) Interference fringes, refractive index Actinic ray curable resin (purple UV-1700B [refractive index: 1.50 to 1.51] manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) constituting the hard coat layer on the laminated polyester film Using a bar coater, it was uniformly coated so that the film thickness after curing was 1.5 μm.

Next, with a concentrating high-pressure mercury lamp (H03-L31 manufactured by Eye Graphics Co., Ltd.) having an irradiation intensity of 120 W / cm set at a height of 9 cm from the surface of the C layer, the integrated irradiation intensity was 300 mJ / cm ² . In this manner, ultraviolet rays were irradiated and cured, and a hard coat layer was laminated on the laminated polyester film to obtain an optical laminated film. Note that an industrial UV checker (UVR-N1 manufactured by Nippon Batteries Co., Ltd.) was used for measuring the cumulative irradiation intensity of ultraviolet rays.

The refractive index of the hard coat layer was measured at a refractive index of 633 nm with a phase difference measuring device (NPDM-1000 manufactured by Nikon Corporation) for the coating film formed on the silicon wafer by a spin coater. As a result, the refractive index of the hard coat layer was 1.50.

Next, a sample having a size of 8 cm (laminated polyester film width direction) × 10 cm (laminated polyester film longitudinal direction) was cut out from the obtained optical laminated film, and a black glossy tape (Yamato Co., Ltd.) was formed on the opposite surface of the hard coat layer. Vinyl tape No. 200-50-21: black) was pasted together so as not to bite the bubbles.

Place this sample in a dark room 30cm directly under a three-wavelength fluorescent lamp (Matsushita Electric Industrial Co., Ltd., 3-wavelength daylight white (F · L 15EX-N 15W)) and visually observe the degree of interference fringes while changing the viewing angle. Observed and evaluated as follows. A practical level was B, and A and S were good.

S: Interference fringes are almost invisible A: Interference fringes are slightly visible B: Weak interference fringes are visible

C: Interference fringes are strong.

(5) Average waviness amplitude measurement The reflectance at a wavelength of 500 to 650 nm on the antireflection layer side of the optical laminated film is measured by the same method as in (3), and the line connecting the peaks of the waviness (the peak line) and the valley bottom of the waviness For the line connecting the parts (valley line), the difference in each wavelength (11 places, where the wavelength is (500 + 10 × i (i = integer from 0 to 10)) nm) at the sample points at intervals of 20 nm (the peak line− The valley bottom line) was determined, and the average was defined as the average waviness amplitude. The average waviness amplitude was 1% or less at a practical level, 0.7% or less was good, and 0.4% or less was very good.

(6) Initial adhesion index 100 crosscuts of 1 mm ² were put on the hard coat layer surface of the optical laminated film. The work was carried out according to the procedure of item 7 of JISK5600-5-6 (1999) except for the following points.
Test conditions and number of tests: Regardless of the provisions of JISK5600-5-6 (1999), section 7.1.1, the test conditions were 23 ° C. and relative humidity 65%. The number of tests was 1.
-Curing of test plates: Regardless of the provisions of JISK5600-5-6 (1999), section 7.1.2, the curing conditions were 23 ° C, relative humidity 65%, and the curing time was 1 hour.
-Number of cuts: The number of cuts was set to 11 regardless of the provisions in Section 7.1.3 of JISK5600-5-6 (1999).
Cut interval: Regardless of the provisions of JISK5600-5-6 (1999), paragraph 7.1.4, the cut interval was set to 1 mm.
・ Cutting and removal of coating film by manual procedure: The provisions of 7.2.5 of JISK5600-5-6 (1999) shall not apply mutatis mutandis. That is, brushing using brush is not performed. Also, JISK5600-5-6 (1999) clause 7.2.6 states the provisions of the second paragraph (“the center of the tape is placed on the grid in a direction parallel to a set of square cuts as shown in FIG. Put the tape flat with your finger at a minimum of 20 mm and the place where it covers the grid, and apply the other rules mutatis mutandis. As the tape, cellophane tape (Cello Tape (registered trademark) CT405AP manufactured by Nichiban Co., Ltd.) is used.

Also, the tape was affixed by using a hand roller (HP 515, manufactured by Audio Technica Co., Ltd.) by reciprocating it at a load of 19.6 N / m at a roller moving speed of 5 cm / sec. Subsequently, the tape was peeled off at a speed of 10 cm / second in a direction of 90 ° with respect to the surface direction of the hard coat layer, and a five-step evaluation was performed based on the remaining number of lattices provided in the hard coat layer. Initial adhesion was very good when 5 or more, good when 4 or more, 3 as practical level, and poor initial adhesion as 2 or less.

5: 100/100 (remaining number / measured number)
4: 90/100 or more, less than 100/100 3: 80/100 or more, less than 90/100 2: 50/100 or more, less than 80/100 1: less than 50/100

(7) Moist heat resistant adhesive index An optical laminated film was obtained in the same manner as in (4). The obtained optical laminated film was left in a constant temperature and humidity chamber at a temperature of 80 ° C. and a relative humidity of 90% for 250 hours to obtain a sample for a moisture and heat resistance test. The obtained sample for moisture and heat resistance test was subjected to an adhesion test in the same manner as in (6), and was subjected to a five-step evaluation based on the number of remaining grids to obtain a moisture and heat resistance index. 5 or higher was very good in heat-and-heat adhesion, 4 or more was good, 3 was a practical level, and 2 or less was poor in heat-and-heat adhesion.

5: 100/100 (remaining number / measured number)
4: 90/100 or more, less than 100/100 3: 80/100 or more, less than 90/100 2: 50/100 or more, less than 80/100 1: less than 50/100

(8) Adhesion index after boiling An optical laminated film was obtained in the same manner as in (4). The obtained optical laminated film was cut into a size of 100 mm × 100 mm, and the film piece was immersed in boiling water (100 ° C.) made of pure water for 3 hours. Thereafter, the film piece was taken out and dried, and an adhesion test was performed in the same manner as in (6). A five-step evaluation was performed based on the number of remaining lattices, and the adhesion index after boiling was obtained. Adhesiveness after boiling 5 or more was very good, 4 or more was good, 3 was a practical level, and 2 or less was poor adhesion after boiling. In addition, the adhesion test after boiling is a very severe test, and even if this test is poor, there is no practical problem as long as the moisture and heat resistant adhesion index of item (7) is at a practical level.

5: 100/100 (remaining number / measured number)
4: 90/100 or more, less than 100/100 3: 80/100 or more, less than 90/100 2: 50/100 or more, less than 80/100 1: less than 50/100

Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited thereto. Moreover, the adjustment method of resin etc. which are used by each Example and a comparative example is shown as a reference example.

Reference Example 1-1 Preparation of fluorene copolymerized polyester resin (A-1) 75 mol parts of dimethyl 2,6-naphthalenedicarboxylate as a dicarboxylic acid component (Aa-2) having no fluorene skeleton under a nitrogen gas atmosphere 90 parts by mole of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene as the glycol component (Ab-1) having a fluorene skeleton, and ethylene glycol 10 as the glycol component (Ab-2) having no fluorene skeleton Mole part was charged into a transesterification reactor, and 100 parts by weight of tetrabutyl titanate (catalyst) was added to 1 million parts by weight of dicarboxylic acid ester derivative (dimethyl succinate) and esterified at 160 to 200 ° C. for 5 hours. After performing the conversion reaction, methanol was distilled off. Furthermore, reaction was performed for 30 minutes under reduced pressure of 240 ° C. and 0.2 MPa to obtain a polyester polyol.

Next, 25 mol parts of 1,2,4,5-benzenetetracarboxylic dianhydride, which is a trivalent or higher polyvalent carboxylic acid component (Aa-4), is added to the polyester polyol at a reaction temperature of 160 to 180 ° C. Reaction was performed for 3 hours to obtain a fluorene copolymer polyester resin (A-1). The Tg of the polyester resin was 130 ° C. Incidentally, the copolymerization amount of the glycol component (Ab-1) having a fluorene skeleton of the fluorene copolymerized polyester resin (A-1) is the sum of the amount of the dicarboxylic acid component (Aa) and the amount of the glycol component (Ab). When it is mol%, it is 45 mol%. The fluorene copolymerized polyester resin (A-1) is a polyester resin that does not have a dicarboxylic acid component (Aa-3) having a sulfonate group.
<Composition of fluorene copolymer polyester resin (A-1)>
(Dicarboxylic acid component and polycarboxylic acid component)
・ 75 parts by mole of 2,6-naphthalenedicarboxylic acid ・ 25 parts by mole of 1,2,4,5-benzenetetracarboxylic acid (glycol component)
・ 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene 90 mol parts ・ Ethylene glycol 10 mol parts (Reference Example 1-2) Fluorene Copolyester Resin (A-1) Aqueous Dispersion (A- Preparation of 1aq) 531.6 parts of water with respect to 100.0 parts by weight of the fluorene copolymerized polyester resin (A-1) (hereinafter simply referred to as “parts”), 2.0 parts of 25% by weight of ammonia water, 33.4 parts of butyl cellosolve was added and dissolved at 40 ° C. Subsequently, the reaction vessel was sealed, the internal temperature of the vessel was raised to 120 ° C., and the reaction was performed for 2 hours to obtain an aqueous dispersion (A-1aq) of a fluorene copolymerized polyester resin. The composition of the aqueous dispersion (A-1aq) of the fluorene copolymerized polyester resin is shown below. The wetting tension of the resin solid obtained by heating and drying A-1aq was 40 mN / m.
Fluorene copolymer polyester resin (A-1): 100 parts (14.993% by weight)
Water: 533.1 parts (79.925% by weight)
Ammonia: 0.5 part (0.075% by weight)
Butyl cellosolve: 33.4 parts (5.007% by weight)
(Reference Example 2-1) Preparation of fluorene copolymerized polyester resin (A-2) The following copolymer composition was added all at once, and transesterification and polycondensation were carried out in the same manner as polyester resin (A-1). A copolyester resin (A-2) was obtained. The Tg of the polyester resin was 130 ° C. The copolymerization amount of the glycol component (Ab-1) having a fluorene skeleton of the fluorene copolymerized polyester resin (A-2) is the sum of the amount of the dicarboxylic acid component (Aa) and the amount of the glycol component (Ab). When mol% is assumed, it is 40 mol%. The copolymerization amount of the dicarboxylic acid component (Aa-3) having a sulfonate group is 5 mol% with respect to the amount of the dicarboxylic acid component (Aa).
As a dicarboxylic acid component (Aa-2) having no fluorene skeleton, 90 mol parts of dimethyl 2,6-naphthalenedicarboxylate, 5 mol parts of dimethyl isophthalate. As a glycol component (Ab-1) having a fluorene skeleton, 9, 80 mol parts of 9-bis [4- (2-hydroxyethoxy) phenyl] fluorene / glycol component (Ab-2) having no fluorene skeleton, 10 mol parts of ethylene glycol, 10 mol parts of diethylene glycol / dicarboxylic acid having a sulfonate group As an acid component (Aa-3), 5 mol parts of dimethyl 5-sodiumsulfoisophthalate.
<Composition of fluorene copolymer polyester resin (A-2)>
(Dicarboxylic acid component and polycarboxylic acid component)
・ 90 parts of 2,6-naphthalenedicarboxylic acid ・ 5 parts of isophthalic acid ・ 5 parts of sodium sulfoisophthalic acid (glycol component)
・ 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene 80 mol parts ・ Ethylene glycol 10 mol parts ・ Diethylene glycol 10 mol parts (Reference Example 2-2) Fluorene Copolyester Resin (A-2) Water Preparation of Dispersion (A-2aq) 100 parts by weight of the fluorene copolymerized polyester resin (A-2) and 400 parts by weight of tetrahydrofuran were dissolved at 80 ° C., and then 500 parts by weight of water at 80 ° C. was added to the polyester. A water / tetrahydrofuran solution of resin (A-2) was obtained. 50 parts by weight of butyl cellosolve was added to the obtained water / tetrahydrofuran solution, and tetrahydrofuran in the obtained solution was distilled. Water was added after cooling, and an aqueous dispersion (A-2aq) of the polyester resin (A-2) was added. )
The composition of the polyester resin aqueous dispersion (A-2aq) is shown below. The wetting tension of the resin solid obtained by heating and drying A-2aq was 46 mN / m.
Fluorene copolymer polyester resin (A-2): 100 parts by weight (10% by weight)
Water: 850 parts by weight (85% by weight)
-Butyl cellosolve: 50 weight part (5 weight%).

(Reference Example 3-1) Preparation of fluorene copolymerized polyester resin (A-3) The following copolymer composition was added all at once, and transesterification and polycondensation were carried out in the same manner as polyester resin (A-1). A copolyester resin (A-3) was obtained. The Tg of the polyester resin was 130 ° C. Incidentally, the copolymerization amount of the glycol component (Ab-1) having a fluorene skeleton of the fluorene copolymerized polyester resin (A-3) is the sum of the amount of the dicarboxylic acid component (Aa) and the amount of the glycol component (Ab) being 100. When mol% is assumed, it is 40 mol%. The copolymerization amount of the dicarboxylic acid component (Aa-3) having a sulfonate group is 10 mol% with respect to the amount of the dicarboxylic acid component (Aa).
As the dicarboxylic acid component (Aa-2) having no fluorene skeleton, 90 mole parts of dimethyl 2,6-naphthalenedicarboxylate As the glycol component (Ab-1) having a fluorene skeleton, 9,9-bis [4- ( 2-hydroxyethoxy) phenyl] fluorene 80 mol part / glycol component (Ab-2) having no fluorene skeleton, ethylene glycol 10 mol part, diethylene glycol 10 mol part / sulfonic acid group-containing dicarboxylic acid component (Aa-3) As 10 parts by weight of dimethyl 5-sodiumsulfoisophthalate.
<Composition of fluorene copolymer polyester resin (A-3)>
(Dicarboxylic acid component and polycarboxylic acid component)
・ 90 parts of 2,6-naphthalenedicarboxylic acid ・ 10 parts of 5-sodiumsulfoisophthalic acid (glycol component)
・ 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene 80 mol parts ・ Ethylene glycol 10 mol parts ・ Diethylene glycol 10 mol parts (Reference Example 3-2) Fluorene Copolyester Resin (A-3) Water Preparation of Dispersion (A-3aq) 100 parts by weight of the fluorene copolymerized polyester resin (A-3) and 400 parts by weight of tetrahydrofuran were dissolved at 80 ° C., and then 500 parts by weight of water at 80 ° C. was added to the polyester. A water / tetrahydrofuran solution of Resin (A-3) was obtained. To the obtained water / tetrahydrofuran solution, 50 parts by weight of butyl cellosolve was added, and tetrahydrofuran in the obtained solution was distilled. Water was added after cooling, and an aqueous dispersion (A-3aq) of the polyester resin (A-3) was added. )
The composition of the polyester resin aqueous dispersion (A-3aq) is shown below. The wetting tension of the resin solid obtained by heating and drying A-3aq was 50 mN / m.
Fluorene copolymer polyester resin (A-3): 100 parts by weight (10% by weight)
Water: 850 parts by weight (85% by weight)
-Butyl cellosolve: 50 weight part (5 weight%).

Reference Example 4 Preparation of Methylol Group Melamine Crosslinker Water Dispersion (B-1aq) Water Dispersion (Sanwa Chemical Co., Ltd.) containing 78.8% by weight of methylol group melamine crosslinker (B-1) “Nicarac” MW12LF) was diluted with water to have the following composition to obtain a methylol-based melamine crosslinking agent aqueous dispersion (B-1aq).
-Methylol-based melamine crosslinking agent (B-1): 25% by weight
-Water: 75 weight%.

Reference Example 5 Preparation of Oxazoline Crosslinking Agent Water Dispersion (B-2aq) An aqueous dispersion containing 10% by weight of an oxazoline crosslinking agent (B-2) (“Epocross” WS300 manufactured by Nippon Shokubai Co., Ltd.) Using.
・ Oxazoline crosslinking agent (B-2): 25% by weight
-Water: 75 weight%.

Reference Example 6 Preparation of Carbodiimide Crosslinking Agent Water Dispersion (B-3aq) An aqueous dispersion (Nisshinbo Co., Ltd. “Carbodilite” V04) containing 40% by weight of carbodiimide crosslinking agent (B-3) has the following composition: Dilution with water to obtain a carbodiimide-based crosslinking agent aqueous dispersion (B-3aq).
-Carbodiimide crosslinking agent (B-3): 25% by weight
-Water: 75 weight%.

Reference Example 7 Preparation of Colloidal Silica Water Dispersion (C-1aq) Water dispersion containing 40% by weight of colloidal silica (“Spherica Slurry 140” manufactured by Catalytic Chemical Industry Co., Ltd.) To obtain a colloidal silica aqueous dispersion (C-1aq).
Colloidal silica: 5% by weight
-Water: 95 weight%.

Reference Example 8 Preparation of Surfactant Water Dispersion (D-1aq) An aqueous dispersion containing 50% by weight of an acetylenic diol surfactant (“Olfin” EXP4051F manufactured by Nissin Chemical Industry Co., Ltd.) has the following composition: The resultant was diluted with water to obtain a surfactant aqueous dispersion (D-1aq).
・ Surfactant: 5% by weight
-Water: 95 weight%.

Reference Example 9-1 Preparation of Polyester Resin (P-1) 60 mol parts of terephthalic acid, 15 mol parts of isophthalic acid, 5 sebacic acid 5 as dicarboxylic acid component (Aa-2) having no fluorene skeleton under nitrogen gas atmosphere As a glycol component (Ab-2) having no fluorene skeleton, 40 mol parts of diethylene glycol, 35 mol parts of 1,4-butanediol and 25 mol parts of ethylene glycol were charged into a transesterification reactor, and tetrabutyl titanate ( (Catalyst) was added in an amount of 100 parts by weight to 1 million parts by weight of the total dicarboxylic acid component, and the esterification reaction was carried out at 160 to 240 ° C. for 5 hours, and then the distillate was removed.

Thereafter, 20 parts by weight of trimellitic acid as a trivalent or higher polyvalent carboxylic acid component (Aa-4) and 100 parts by weight of tetrabutyl titanate with respect to 1 million parts by weight of the total dicarboxylic acid were added at 240 ° C. After removing the distillate until the reaction product became transparent, a polycondensation reaction was performed under reduced pressure at 220 to 280 ° C. to obtain a polyester resin (P-1). The Tg of the polyester resin was 20 ° C.

The polyester resin (P-1) is a polyester resin in which a component having a fluorene skeleton is not copolymerized. The polyester resin (P-1) is a polyester resin that does not have a dicarboxylic acid component (Aa-3) having a sulfonate group.
<Composition of polyester resin (P-1)>
(Dicarboxylic acid component and polycarboxylic acid component)
・ 60 mol parts of terephthalic acid ・ 15 mol parts of isophthalic acid ・ 5 mol parts of sebacic acid ・ 20 mol parts of trimellitic acid (glycol component)
-40 mol part of diethylene glycol-35 mol part of 1,4-butanediol-25 mol part of ethylene glycol

Reference Example 9-2 Preparation of Polyester Resin (P-1) Water Dispersion (P-1aq) Water dispersion was carried out in the same manner as the fluorene copolymerized polyester resin (A-1), and the polyester resin aqueous dispersion ( P-1aq) was obtained. The wetting tension of the resin solid obtained by heating and drying P-1aq was 40 mN / m.
The composition of the polyester resin aqueous dispersion (P-1aq) is shown below.
Polyester resin (P-1): 100 parts (25.000% by weight)
Water: 299.9 parts by weight (74.975% by weight)
-Ammonia: 0.1 weight part (0.025 weight%).

Reference Example 10-1 Preparation of Polyester Resin (P-2) 60 mol parts of terephthalic acid, 15 mol parts of isophthalic acid, 15 sebacic acid 15 as a dicarboxylic acid component (Aa-2) having no fluorene skeleton under nitrogen gas atmosphere As a glycol component (Ab-2) having no fluorene skeleton, 40 mol parts of diethylene glycol, 35 mol parts of 1,4-butanediol and 25 mol parts of ethylene glycol were charged into a transesterification reactor, and tetrabutyl titanate ( (Catalyst) was added in an amount of 100 parts by weight to 1 million parts by weight of the total dicarboxylic acid component, and the esterification reaction was carried out at 160 to 240 ° C. for 5 hours, and then the distillate was removed.

Thereafter, 10 parts by weight of dimethyl 5-sodiumsulfoisophthalate as a dicarboxylic acid component (Aa-3) having a sulfonate group and 100 parts by weight of tetrabutyl titanate are further added to 1 million parts by weight of the total dicarboxylic acid component. After removing the distillate at 240 ° C. until the reaction product became transparent, a polycondensation reaction was performed under reduced pressure at 220 to 280 ° C. to obtain a polyester resin (P-2). The Tg of the polyester resin was 20 ° C. The polyester resin (P-2) is a polyester resin in which a component having a fluorene skeleton is not copolymerized. The copolymerization amount of the dicarboxylic acid component (Aa-3) having a sulfonate group is 10 mol% with respect to the amount of the dicarboxylic acid component (Aa).
<Composition of polyester resin (P-2)>
(Dicarboxylic acid component and polycarboxylic acid component)
・ Terephthalic acid 60 mol part ・ Isophthalic acid 15 mol part ・ Sebacic acid 15 mol part ・ 5-sodium sulfoisophthalic acid 10 mol part (glycol component)
Diethylene glycol 40 mol parts 1,4-butanediol 35 mol parts Ethylene glycol 25 mol parts (Reference Example 10-2) Preparation of polyester resin (P-2) aqueous dispersion (P-2aq) Polyester resin (P- 2) After dissolving 100 parts by weight and 75 parts by weight of tetrahydrofuran at 80 ° C., 250 parts by weight of water at 80 ° C. was added to obtain a water / tetrahydrofuran solution of the polyester resin (P-2). Further, tetrahydrofuran in the obtained solution was distilled, and water was added after cooling to obtain an aqueous dispersion (P-2aq) of a polyester resin. The wetting tension of the resin solid obtained by heating and drying P-2aq was 50 mN / m.
The composition of the aqueous dispersion (P-2aq) of the polyester resin is shown below.
Polyester resin (P-2): 100 parts (25% by weight)
-Water: 300 parts (75 weight%).

Reference Example 11-1 Preparation of Polyester Resin (P-3) Polyester resin (P-3) was prepared by the transesterification and polycondensation in the following copolymer composition in the same manner as polyester resin (P-2). Obtained. The Tg of the polyester resin was 100 ° C. The polyester resin (P-3) is a polyester resin in which a component having a fluorene skeleton is not copolymerized. The copolymerization amount of the dicarboxylic acid component (Aa-3) having a sulfonate group is 1 mol% with respect to the amount of the dicarboxylic acid component (Aa).
・ 99 mol parts of 2,6-naphthalenedicarboxylic acid as dicarboxylic acid component (Aa-2) not having fluorene skeleton ・ 90 mol parts of ethylene glycol and 10 mol parts of diethylene glycol as glycol component (Ab-2) not having fluorene skeleton ・1 mol part of dimethyl 5-sodiumsulfoisophthalate as the dicarboxylic acid component (Aa-3) having a sulfonate group.
<Composition of polyester resin (P-3)>
(Dicarboxylic acid component and polycarboxylic acid component)
・ 99 parts by mole of 2,6-naphthalenedicarboxylic acid ・ 1 mole part of 5-sodiumsulfoisophthalic acid (glycol component)
-Ethylene glycol 90 mol part-Diethylene glycol 10 mol part (Reference Example 11-2) Preparation of polyester resin (P-3) aqueous dispersion (P-3aq)
100 parts by weight of polyester resin (P-3) and 400 parts of tetrahydrofuran were dissolved at 80 ° C., and then 500 parts by weight of water at 80 ° C. were added to obtain a water / tetrahydrofuran solution of polyester resin (P-3). . To the obtained water / tetrahydrofuran solution, 50 parts by weight of butyl cellosolve was added, and tetrahydrofuran in the obtained solution was distilled. After cooling, water was added to obtain an aqueous dispersion (P-3aq) of a polyester resin. The wetting tension of the resin solid obtained by heating and drying P-1aq was 42 mN / m.
The composition of the polyester resin aqueous dispersion (P-3aq) is shown below.
Polyester resin (P-3): 100 parts by weight (10% by weight)
Water: 850 parts by weight (85% by weight)
-Butyl cellosolve: 50 weight part (5 weight%).

Reference Example 12 Preparation of Acrylic Emulsion (Q-1) 1 part by weight of p-dodecylbenzenesulfonic acid Na as an emulsifier (Qa-1) and methacryl as a monomer in 300 parts of water serving as a solvent under reduced pressure in a nitrogen gas atmosphere 65 parts by weight of methyl acid (MMA) (Qb-1), 30 parts by weight of ethyl methacrylate (EMA) (Qb-2), 3 parts by weight of N-methylolacrylamide (N-MAM) (Qb-3), acrylic acid ( AA) (Qb-4) 2 parts by weight were charged into an emulsion polymerization reactor, and 100 parts by weight of sodium persulfate (initiator) was added to 1 million parts by weight of the total monomer components, and the mixture was heated at 30-80 ° C. After reacting for 10 hours, the pH was adjusted to 7.0 to 9.0 with an aqueous ammonia solution (alkali).

Thereafter, unreacted monomers were removed and concentrated under reduced pressure at 70 ° C. to obtain 35% of an acrylic emulsion. The average particle diameter of the acrylic emulsion was 45 nm and Tg was 55 ° C. The wetting tension of the solid resin obtained by heating and drying Q-1aq was 36 mN / m.
<Composition of acrylic resin (Q-1)>
-65 parts by weight of methyl methacrylate-30 parts by weight of ethyl methacrylate-3 parts by weight of N-methylolacrylamide-2 parts by weight of acrylic acid (Reference Example 13) Preparation of acrylic emulsion (Q-2) under reduced pressure under nitrogen gas atmosphere In 300 parts of water as a solvent, 1 part by weight of p-dodecylbenzenesulfonic acid Na as an emulsifier (Qa-1), 62 parts by weight of methyl methacrylate (MMA) (Qb-1) as a monomer, ethyl methacrylate (EMA) (Qb -2) 30 parts by weight, 3 parts by weight of N-methylolacrylamide (N-MAM) (Qb-3) and 5 parts by weight of acrylic acid (AA) (Qb-4) were charged into an emulsion polymerization reactor, and persulfuric acid was added thereto. Add 100 parts by weight of sodium (initiator) to 1 million parts by weight of all monomer components, and at 30-80 ° C. for 10 hours After the response, it was adjusted to be pH 7.0 ~ 9.0 with aqueous ammonia (alkali).

Thereafter, unreacted monomers were removed and concentrated under reduced pressure at 70 ° C. to obtain 35% of an acrylic emulsion. The average particle diameter of the acrylic emulsion was 45 nm and Tg was 55 ° C. Further, the wetting tension of the resin solid material obtained by heating and drying Q-2aq was 38 mN / m.
<Composition of acrylic resin (Q-2)>
-62 parts by weight of methyl methacrylate-30 parts by weight of ethyl methacrylate-3 parts by weight of N-methylolacrylamide-5 parts by weight of acrylic acid (Reference Example 14) Preparation of acrylic emulsion (Q-3) under reduced pressure under nitrogen gas atmosphere In 300 parts of water as a solvent, 1 part by weight of p-dodecylbenzenesulfonic acid Na as an emulsifier (Qa-1), 60 parts by weight of methyl methacrylate (MMA) (Qb-1) as a monomer, ethyl methacrylate (EMA) (Qb -2) 27 parts by weight, 3 parts by weight of N-methylolacrylamide (N-MAM) (Qb-3) and 10 parts by weight of acrylic acid (AA) (Qb-4) were charged into an emulsion polymerization reactor, and persulfuric acid was added thereto. Add 100 parts by weight of sodium (initiator) to 1 million parts by weight of all monomer components, and 10 hours at 30-80 ° C. After the reaction, it was adjusted so that the pH 7.0 ~ 9.0 with aqueous ammonia (alkali).

Thereafter, unreacted monomers were removed and concentrated under reduced pressure at 70 ° C. to obtain 35% of an acrylic emulsion. The average particle diameter of the acrylic emulsion was 45 nm and Tg was 55 ° C. The wetting tension of the solid resin material obtained by heating and drying Q-3aq was 40 mN / m.
<Composition of acrylic resin (Q-3)>
・ Methyl methacrylate 60 parts by weight ・ Ethyl methacrylate 27 parts by weight ・ N-methylolacrylamide 3 parts by weight ・ Acrylic acid 10 parts by weight (Reference Example 15) Preparation of acrylic emulsion (Q-4) In 300 parts of water as a solvent, 1 part by weight of p-dodecylbenzenesulfonic acid Na as an emulsifier (Qa-1), 62 parts by weight of methyl methacrylate (MMA) (Qb-1) as a monomer, ethyl methacrylate (EMA) (Qb -2) 30 parts by weight, N-methylolacrylamide (N-MAM) (Qb-3) 3 parts by weight, acrylic acid (AA) (Qb-4) 0.25 parts by weight, acrylonitrile (AN) (Qb-5) 4.75 parts by weight are charged into an emulsion polymerization reactor, and sodium persulfate (initiator) is added to the total monomer component of 1 million. After adding 100 parts by weight with respect to parts by weight and reacting at 30 to 80 ° C. for 10 hours, the pH was adjusted to 7.0 to 9.0 with an aqueous ammonia solution (alkali).

Thereafter, unreacted monomers were removed and concentrated under reduced pressure at 70 ° C. to obtain 35% of an acrylic emulsion. The average particle diameter of the acrylic emulsion was 40 nm, and Tg was 55 ° C. Further, the wetting tension of the resin solid obtained by heating and drying Q-4aq was 34 mN / m.
<Composition of acrylic resin (Q-4)>
-62 parts by weight of methyl methacrylate-30 parts by weight of ethyl methacrylate-3 parts by weight of N-methylolacrylamide-0.25 parts by weight of acrylic acid-4.75 parts by weight of acrylonitrile Example 1
A PET film to be a base material layer (S layer) is prepared. PET pellets (intrinsic viscosity 0.63 dl / g) substantially free of externally added particles are sufficiently vacuum-dried, then supplied to an extruder, melted at 285 ° C., and sintered by compressing stainless steel fibers. After filtering with a 5 μm filter and then with a sintered filter of stainless steel powder with an average opening of 14 μm, it is extruded into a sheet form from a T-shaped die, and mirror casting with a surface temperature of 25 ° C. using an electrostatic application casting method. It was wound around a drum and solidified by cooling. This unstretched film was heated to 90 ° C. and stretched 3.4 times in the longitudinal direction to obtain a uniaxially oriented (uniaxially stretched) film.

Next, various aqueous dispersions prepared in the above reference examples were mixed at the ratios shown in Table 3 and Table 5 (comparative examples are shown in Table 7 and Table 9), and the aqueous coating composition constituting the C layer was changed to Table 4 and The compositions shown in Table 6 (comparative examples are shown in Tables 8 and 10) were prepared. The obtained aqueous coating material was applied to the uniaxially stretched film using the bar coating method shown in FIG. At this time, the gap (X) between the metalling wire bar and the upstream cover was 1.2 mm, and the gap (Y) between the metalling wire bar and the downstream cover was 0.5 mm.

A uniaxially stretched film coated with a water-based coating was held with a clip and guided to a preheating zone, dried and preheated at an atmospheric temperature of 120 ° C., and continuously stretched 3.5 times in the width direction in a 120 ° C. stretching zone. The obtained biaxially oriented (biaxially stretched) film was subsequently heat treated in a heating zone at 230 ° C. for 10 seconds, then subjected to a 7% relaxation treatment while cooling from 230 ° C. to 160 ° C., and subsequently from 160 ° C. to 120 ° C. Re-stretching of 0.5% was performed while cooling to ° C. A laminated polyester film in which the C layer was laminated on the S layer in which crystal orientation was completed by the above method was obtained.

The thickness of this laminated polyester film was 125 μm, the TD heat yield at 120 ° C. for 30 minutes was 0.4%, the TD heat yield at 190 ° C. for 20 minutes was 0.1%, the thickness of the C layer was 128 nm, and the tolerance was 8 nm. . Table 2 shows the characteristics of the obtained laminated polyester film. The interference fringes of the optical laminated film were at a practical level and the average waviness amplitude was good. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Example 2
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 122 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also very good. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Example 3
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this optical laminated film are shown in Table 2. The interference fringes of the optical laminated film were at a practical level and the average waviness amplitude was good. The wetting tension on the surface of the C layer was 2 mN / m higher than that of the acrylic resin (Q-1) composition film (Comparative Example 7), but both the initial adhesion index with the hard coat layer and the wet heat resistance index were good. However, the adhesion index after boiling was at a practical level.

Example 4
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 128 nm, and the tolerance was 8 nm. Table 2 shows the characteristics of the obtained laminated polyester film. The interference fringes of the optical laminated film were at a practical level and the average waviness amplitude was good. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-4) composition film (Comparative Example 9), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are both very good. there were.

Example 5
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 122 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also very good. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-4) composition film (Comparative Example 9), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are both very good. there were.

Example 6
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this optical laminated film are shown in Table 2. The interference fringes of the optical laminated film were at a practical level and the average waviness amplitude was good. Further, the wetting tension on the surface of the C layer was 1 mN / m higher than that of the acrylic resin (Q-4) composition film (Comparative Example 9), but both the initial adhesion index to the hard coat layer and the wet heat resistance index were good. However, the adhesion index after boiling was at a practical level.

Example 7
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 128 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were practical levels. Further, the wetting tension on the surface of the C layer was the same as that of the acrylic resin (Q-2) composition film (Comparative Example 8), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling were all very good. It was.

Example 8
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 122 nm, and the tolerance was 8 nm. The properties of this laminated film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also very good. Further, the wetting tension on the surface of the C layer was equivalent to that of the acrylic resin (Q-2) composition film (Comparative Example 8), and both the initial adhesion index and the wet heat resistance index with the hard coat layer were very good. The adhesion index of was good.

Example 9
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 123 nm, and the tolerance was 8 nm. The properties of this laminated film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also very good. Further, since an oxazoline-based crosslinking agent and a carbodiimide-based crosslinking agent were used in addition to the melamine-based crosslinking agent, the adhesion index after boiling with the hard coat layer was improved to a very good level.

Example 10
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 3 and 4 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. The minimum value was a practical level, the interference fringes of the optical laminated film were a practical level, and the average waviness amplitude was good. Further, the wetting tension on the surface of the C layer was 1 mN / m higher than that of the acrylic resin (Q-2) composition film (Comparative Example 8), but both the initial adhesion index to the hard coat layer and the wet heat resistance index were good. However, the adhesion index after boiling was at a practical level.

Example 11
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 128 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were practical levels. The wetting tension on the surface of the C layer was equivalent to that of the acrylic resin (Q-2) composition film (Comparative Example 8), and the initial adhesion index with the hard coat layer was very good, but the polyester resin having a sulfonic acid group was formed. Although it was a component, the adhesion index after boiling was a rejected level, but the moisture and heat resistance index was good.

Example 12
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were practical levels. Further, the wetting tension on the surface of the C layer was 1 mN / m higher than that of the acrylic resin (Q-2) composition film (Comparative Example 8), and the initial adhesion index with the hard coat layer was good. The initial adhesion index was good because it has polyester resin as the main component, but the moisture and heat resistance index is a failure level, and the adhesion index after boiling is not measurable because the hard coat peeled off in the boiling process there were.

Example 13
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 128 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were practical levels. Further, the wetting tension on the surface of the C layer was equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index with the hard coat layer was very good, but it constituted a polyester resin having a sulfonic acid group. Although it was a component, the adhesion index after boiling was a rejected level, but the moisture and heat resistance index was good.

Example 14
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 122 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were good. Further, the wetting tension on the surface of the C layer was equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index with the hard coat layer was very good, but it constituted a polyester resin having a sulfonic acid group. Since it was a component, the adhesion index after boiling was at a rejected level, but the moist heat resistant index was at a practical level.

Example 15
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 123 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were good. Moreover, in addition to the melamine-based crosslinking agent, an oxazoline-based crosslinking agent and a carbodiimide-based crosslinking agent were used, but because the polyester resin having a sulfonic acid group is a constituent component, the adhesion index after boiling was a failure level, The moisture and heat resistance index was good.

Example 16
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were practical levels. The wetting tension on the surface of the C layer was 1 mN / m higher than that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index with the hard coat layer was good. The initial adhesion index was good because it has polyester resin as the main component, but the moisture and heat resistance index is a failure level, and the adhesion index after boiling is not measurable because the hard coat peeled off in the boiling process there were.

Example 17
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 81 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also good. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Example 18
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 162 nm, and the tolerance was 10 nm. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also at a practical level. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Example 19
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used and the coating was performed by the bar coating method shown in FIG. At this time, the gap (a) between the metalling wire bar and the upstream cover was 1.2 mm, and the gap (b) between the metalling wire bar and the downstream cover was 0.5 mm. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 122 nm, and the tolerance was 15 nm. The properties of this laminated polyester film are shown in Table 2. Although the average waviness amplitude of the optical laminated film was very good, the interference fringes were partially observed at a slightly stronger level as compared with Example 2. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Example 20
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used and the coating was performed using the gravure coating method. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 122 nm, and the tolerance was 30 nm. The properties of this laminated polyester film are shown in Table 2. Although the average waviness amplitude of the optical laminated film was very good, the interference fringes were partially observed at a slightly stronger level as compared with Example 2. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Example 21
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 5 and 6 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 117 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also at a practical level. Further, the wetting tension on the surface of the C layer was 1 mN / m higher than that of the acrylic resin (Q-1) composition film (Comparative Example 7), but both the initial adhesion index to the hard coat layer and the wet heat resistance index were good. Met. However, the adhesion index after boiling was a failure level.

Example 22
Except for applying the corona discharge treatment to both surfaces of the uniaxially stretched film using the aqueous coating agents shown in Tables 5 and 6, and applying the both surfaces using the bar coating method shown in FIG. A laminated polyester film was obtained. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 122 nm on both sides, and the tolerance was 8 nm on both sides. The properties of this laminated polyester film are shown in Table 2. The interference fringes and average waviness amplitude of the optical laminated film were also very good. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Comparative Example 1
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 115 nm, and the tolerance was 25 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. The initial adhesion index was at a practical level, but the moisture and heat resistance adhesion index and the adhesion index after boiling were at a rejected level.

Comparative Example 2
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 115 nm, and the tolerance was 20 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. In addition, both the initial adhesion index and the moisture and heat resistance adhesion index were unacceptable levels, and the adhesion index after boiling was not measurable because the hard coat was peeled off during the boiling process.

Comparative Example 3
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 115 nm, and the tolerance was 15 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. In addition, both the initial adhesion index and the moisture and heat resistance adhesion index were unacceptable levels, and the adhesion index after boiling was not measurable because the hard coat was peeled off during the boiling process.

Comparative Example 4
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 115 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. The initial adhesion index was at a practical level, but the moisture and heat resistance adhesion index and the adhesion index after boiling were at a rejected level.

Comparative Example 5
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 115 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. In addition, both the initial adhesion index and the moisture and heat resistance adhesion index were unacceptable levels, and the adhesion index after boiling was not measurable because the hard coat was peeled off during the boiling process.

Comparative Example 6
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The laminated polyester film had a thickness of 125 μm and the C layer had a thickness of 115 nm. The properties of this laminated polyester film are shown in Table 2. Since the polyester resin having a naphthalene skeleton is the main composition of the layer C of this laminated polyester film, the stretchability of the layer C is poor and whitening occurred in the stretching step, so the predetermined evaluation was not performed.

Comparative Example 7
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 136 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. Further, the initial adhesion index, the moist heat resistance index and the adhesion index after boiling were all very good.

Comparative Example 8
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 136 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. Further, the initial adhesion index, the moist heat resistance index and the adhesion index after boiling were all very good.

Comparative Example 9
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 136 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the average swell amplitude and the fringe pattern of the optical laminated film were unacceptable. Moreover, both the initial adhesion index and the moist heat resistance index were very good, and the adhesion index after boiling was good.

Comparative Example 10
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 7 and 8 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 130 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are all very good. there were.

Comparative Example 11
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. Also, the wetting tension on the surface of the C layer is equivalent to that of the polyester resin (A-1) composition film (Comparative Example 1), and the initial adhesion index with the hard coat layer is a practical level, the moisture and heat resistance index and the adhesion index after boiling are rejected. It was a level.

Comparative Example 12
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 130 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. The wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-4) composition film (Comparative Example 9), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are both very good. there were.

Comparative Example 13
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 130 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. Further, the wetting tension on the surface of the C layer was equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index with the hard coat layer was very good, but the moisture and heat resistance index was good. However, the adhesion index after boiling was not acceptable.

Comparative Example 14
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. The wetting tension on the surface of the C layer is similar to that of the polyester resin (A-3) composition film (Comparative Example 1), the initial adhesion index with the hard coat layer is a practical level, and the moisture and heat resistance index is a reject level. The adhesion index after boiling was not measurable because the hard coat was peeled off during the boiling process.

Comparative Example 15
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 128 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. Moreover, both the initial adhesion index with the hard coat layer and the wet heat resistance index were good, and the adhesion index after boiling was at a practical level.

Comparative Example 16
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. The initial adhesion index with the hard coat layer and the moisture and heat resistance adhesion index were practical levels, but the boiling index after boiling was a failure level.

Comparative Example 17
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 128 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. The wetting tension on the surface of the C layer was equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index with the hard coat layer was very good. Since the resin contains a large amount of sulfonate group, the moisture and heat resistance index was unacceptable, and the adhesion index after boiling was not measurable because the hard coat was peeled off during the boiling process.

Comparative Example 18
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm, the C layer had a thickness of 116 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. The wetting tension on the surface of the C layer is the same as that of the acrylic resin (Q-1) composition film (Comparative Example 7). However, since the main component of the C layer is a polyester resin, the initial adhesion index with the hard coat layer is extremely high. Since the polyester resin contains a large amount of sulfonate group, the moisture and heat resistance index is unacceptable, and the adhesion index after boiling was not measurable because the hard coat was peeled off during the boiling process. .

Comparative Example 19
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 122 nm, and the tolerance was 8 nm. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. Further, the wetting tension on the surface of the C layer is equivalent to that of the acrylic resin (Q-1) composition film (Comparative Example 7), and the initial adhesion index to the hard coat layer, the moisture and heat resistance index, and the adhesion index after boiling are extremely good. It was.

Comparative Example 20
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The laminated polyester film had a thickness of 125 μm and the C layer had a thickness of 122 nm. The properties of this laminated polyester film are shown in Table 2. The ratio of the polyester resin having a naphthalene skeleton as a constituent component of the C layer is high, but since the acrylic resin (Q-1) is added, the stretchability of the C layer is improved and the whitening tends to be improved. However, since the coating unevenness of the appearance of the C layer remained, it could not be used as an optical film, so the predetermined evaluation was not performed.

Comparative Example 21
A laminated polyester film was obtained in the same manner as in Example 1 except that the aqueous coating agents shown in Tables 9 and 10 were used. The thickness of this laminated polyester film was 125 μm, the thickness of the C layer was 115 nm, and the tolerance was 8 nm. Part of the polyester resin having a naphthalene skeleton was contained as a component of the C layer, but no whitening occurred because the polyester resin (P-1) was the main component. The properties of this laminated polyester film are shown in Table 2. Both the interference fringes and the average waviness amplitude of the optical laminated film were unacceptable levels. Moreover, although both the initial adhesion index with the hard coat layer and the moist heat resistance adhesion index were practical levels, the adhesion index after boiling was a failure level.

The laminated polyester film of the present invention is useful for a hard coat film because of its excellent adhesion to a hard coat layer in a high temperature and high humidity environment. In particular, it is excellent in reducing iris patterns and is suitable as a laminated film for display members such as touch panels.

1 Base film (A layer)
2 Advancing direction of base film 3 Metalling wire bar 4 Roll for gripping bar 5 Cover on the upstream side of the metalling wire bar 6 Cover on the downstream side of the metalling wire bar 7 Coating agent supply section 8 Liquid receiving pan 9 Coating liquid a The gap between the metering wire bar and the upstream cover b The gap between the metalling wire bar and the downstream cover 11 Waviness amplitude 12 Peak line 13 Hard coat layer side reflectance curve 14 Valley bottom line

Claims (9)

A polyester film in which a laminated film (C layer) is laminated on at least one surface of a layer (S layer) made of polyester as a base material layer, the spectral reflectance at a wavelength of 500 nm to 650 nm on the C layer side The minimum value (Rmin) is 4.0% or more and 6.0% or less, and the change amount (Δr) of the spectral reflectance is 0.0% or more and 1.0% or less. the film. The C layer contains a polyester resin (A) having a fluorene skeleton and / or a naphthalene skeleton and an acrylic resin (Q), and the content (a) and the acrylic resin (Q) of the polyester resin (A) in the C layer. The laminated polyester film according to claim 1, wherein the weight ratio (a) / (b) of the content (b) is 40/60 or more and 95/5 or less. The laminated polyester film according to claim 2, wherein the wetting tension of the polyester resin (A) is higher than the wetting tension of the acrylic resin (Q), and the difference is 2 mN / m or more and 10 mN / m or less. The laminated polyester film according to claim 2 or 3, wherein the wetting tension of the polyester resin (A) is higher than the wetting tension of the acrylic resin (Q), and the difference thereof is 2 mN / m or more and 6 mN / m or less. The polyester resin (A) has at least a fluorene skeleton, and the polyester resin (A) does not have a dicarboxylic acid component (Aa-3) having a sulfonate group, or constitutes a polyester resin (A) The laminated polyester film according to any one of claims 2 to 4, which has less than 0.1 mol% based on the amount of the dicarboxylic acid component (Aa) to be produced. The laminated polyester film according to any one of claims 1 to 5, wherein a thickness tolerance of the C layer is 10 nm or less. The initial adhesion index of the surface of the C layer, the moisture and heat resistance adhesion index when left in a constant temperature and humidity environment at a temperature of 80 ° C. and a relative humidity of 90%, and the adhesion index after boiling for 3 hours are all The laminated polyester film according to any one of claims 1 to 6, which is 3 or more and 5 or less. A hard coat layer using an actinic radiation curable resin is laminated on the surface of the layer C of the laminated polyester film according to any one of claims 1 to 7, and the hard coat layer side has a wavelength of 500 nm to 650 nm. An optical laminated film having an average waviness amplitude of spectral reflectance of 1.0% or less. The optical laminated film according to claim 8, wherein the refractive index of the hard coat layer is 1.43 to 1.60.

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