WO2023032373A1

WO2023032373A1 - Optical film, polarizing plate, and liquid crystal display device

Info

Publication number: WO2023032373A1
Application number: PCT/JP2022/022084
Authority: WO
Inventors: 卓哉小出; 公志田坂; 崇南條
Original assignee: コニカミノルタ株式会社
Priority date: 2021-09-01
Filing date: 2022-05-31
Publication date: 2023-03-09
Also published as: JPWO2023032373A1; TW202311047A; TWI825774B

Abstract

This optical film has an easily adhesive layer on at least one side of a substrate, the substrate containing a cycloolefin-based resin, the thickness of the substrate being 49 µm or less, the easily adhesive layer containing a polyurethane-based resin, and the nanoindentation hardness of the easily adhesive layer on the substrate being less than 0.52 GPa in a 23°C/50% RH environment.

Description

Optical films, polarizing plates and liquid crystal displays

The present invention relates to an optical film, a polarizing plate, and a liquid crystal display device, and more particularly to an optical film and the like that can improve adhesion to a polarizer layer and suppress light leakage in a high-temperature and high-humidity environment.

A polarizing plate used in an image display device such as a TV or a smart phone has an optical film laminated on both sides of a polarizer layer via an easy-adhesion layer.
In recent years, due to the increase in the size of image display devices, there has been a demand for large-sized polarizing plates as members, and there has also been a demand for large-sized optical films.
In addition, it is common for image display devices to be transported overseas by sea from the time they are manufactured to the time they are sold. Light leakage (white unevenness) caused by misalignment and adhesion failure due to the increase in size of the film have become apparent, and improvements have been required.

Therefore, as a technique for preventing peeling of an optical film, for example, as disclosed in Patent Document 1, a urethane composition containing polyurethane having a weight average molecular weight of 30,000 to 100,000 is applied to the surface of an optical film made of an acrylic resin. Techniques have been proposed for improving the adhesiveness between a polarizer and an acrylic resin film by providing a layer. In Patent Document 1, since an acrylic resin film is used, retardation is less likely to occur, and problems such as peeling of the film and light leakage are less likely to occur.

On the other hand, in the case of an optical film using a cycloolefin resin, which is said to be excellent in transparency, optical properties and durability, retardation is likely to occur due to the application of stress, so the film will peel off under high temperature and high humidity. Problems with poor adhesion and light leakage remained unresolved.

JP 2016-79210 A

The present invention has been made in view of the above problems and circumstances, and the problem to be solved is to improve the adhesiveness with the polarizer layer in a high-temperature and high-humidity environment and to suppress light leakage. It is to provide a film, a polarizing plate and a liquid crystal display device.

In order to solve the above problems, in the process of studying the causes of the above problems, the present inventors have found that by reducing the nanoindentation hardness of the easy-adhesion layer, a thin optical film made of a cycloolefin resin can be obtained. Also, the inventors have found that the adhesiveness to the polarizer layer is good in a high-temperature and high-humidity environment and that light leakage can be suppressed, leading to the present invention.
That is, the above problems related to the present invention are solved by the following means.

1. An optical film having an easy-adhesion layer on at least one surface of a substrate,
The base material contains a cycloolefin resin,
The thickness of the base material is 49 μm or less,
The easy-adhesion layer contains a polyurethane-based resin,
An optical film, wherein the nanoindentation hardness of the easy-adhesion layer on the substrate is less than 0.52 GPa under environmental conditions of 23°C and 50% RH.

2. 2. The optical film according to item 1, wherein the polyurethane-based resin comprises either one of a polyester polyol component and a polyether polyol component.

3. The easy-adhesion layer contains silica fine particles,
The average primary particle size of the silica fine particles is in the range of 50 to 150 nm, and
3. The optical film according to item 1 or item 2, wherein the standard deviation of the average primary particle diameter is in the range of 5 to 30 nm.

4. A polarizing plate comprising the optical film according to any one of items 1 to 3.

5. A liquid crystal display device comprising the polarizing plate according to item 4.

By the means of the present invention, it is possible to provide an optical film, a polarizing plate, and a liquid crystal display device that have improved adhesiveness to a polarizer layer and can suppress light leakage in a high-temperature and high-humidity environment.
Although the expression mechanism or action mechanism of the effects of the present invention has not been clarified, it is speculated as follows.
The thickness of the substrate is 49 μm or less, and the nanoindentation hardness of the easy-adhesion layer on the substrate is less than 0.52 GPa. Since the water content can be reduced, the hardness of the film can be kept constant, and by lowering the hardness of the easy-adhesion layer, the stress applied to the optical film in the polarizing plate can be relaxed, and the It is possible to reduce the stress strain under wet conditions. Therefore, by thinning the substrate and reducing the hardness of the easy-adhesion layer, it is possible to suppress the displacement between the polarizer layer and the optical film. As a result, the adhesion between the polarizer layer and the optical film is improved, and light leakage can be suppressed.

Schematic diagram showing an example of the configuration of the polarizing plate of the present invention Schematic diagram showing an example of the configuration of the liquid crystal display device of the present invention

The optical film of the present invention is an optical film having an easy-adhesion layer on at least one surface of a substrate, the substrate contains a cycloolefin resin, and the thickness of the substrate is 49 μm or less. The easy-adhesion layer contains a polyurethane-based resin, and the easy-adhesion layer has a nanoindentation hardness of less than 0.52 GPa on the substrate under environmental conditions of 23° C. and 50% RH.
This feature is a technical feature common to or corresponding to each of the following embodiments.

As an embodiment of the present invention, it is preferable that the polyurethane-based resin consists of either one of a polyester polyol component and a polyether polyol component. That is, by using a polyester polyol component or a polyether polyol component with a higher polarity than a polycarbonate component with a low polarity, the nanoindentation hardness of the easy adhesion layer can be lowered. Therefore, the difference in dimensional variation between the optical film and the polarizer layer can be reduced, the stress applied to the film can be reduced, and it is effective in improving adhesion and suppressing light leakage.

Further, the easy-adhesion layer contains silica fine particles, the average primary particle size of the silica fine particles is in the range of 50 to 150 nm, and the standard deviation of the average primary particle size is in the range of 5 to 30 nm. By setting the average primary particle size and the standard deviation within the above ranges, the density and surface area of the silica fine particles are increased, and when it becomes hygroscopic due to durability, the entire easy-adhesion layer It is preferable in that it uniformly absorbs water and makes it possible to obtain hardness of the easy-adhesion layer, that is, a stress-relaxable state.

The optical film of the present invention is suitably used as a polarizing plate, and the polarizing plate is suitably used as a liquid crystal display device.

The following describes the present invention, its constituent elements, and the forms and modes for carrying out the present invention. In the present application, "-" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

[Overview of the optical film of the present invention]
The optical film of the present invention is an optical film having an easy-adhesion layer on at least one surface of a substrate, the substrate contains a cycloolefin resin, and the thickness of the substrate is 49 μm or less. The easy-adhesion layer contains a polyurethane-based resin, and the easy-adhesion layer has a nanoindentation hardness of less than 0.52 GPa on the substrate under environmental conditions of 23° C. and 50% RH.

<Nanoindentation hardness>
The nanoindentation hardness of the easy-adhesion layer on the substrate according to the present invention was measured using a Triboscope (manufactured by Bruker). For the measurement, an indenter having a tip edge angle of 90° and a tip curvature radius of 35 to 50 nm was used.
As a measurement sample, an optical film is cut into 2 cm squares, and the base material side is attached on a metal plate using an adhesive. I performed the return operation. A value P/A obtained by dividing the maximum load P at this time by the area A of the indenter contact portion was calculated as the nanoindentation hardness. The maximum load was set to 20 μN.
Ten points were randomly measured for each sample, and the average value was taken as the nanoindentation hardness. The nanoindentation hardness of the easy-adhesion layer on the substrate at 23° C. and 50% RH measured as described above is less than 0.52 GPa and is within the range of 0.36 to 0.50 GPa. Preferably, it is particularly preferably in the range of 0.36 to 0.40 GPa.

Further, as means for making the nanoindentation hardness of the easy-adhesion layer less than 0.52 GPa, for example, the component composition of the polyurethane-based resin contained in the easy-adhesion layer, or the silica fine particles contained in the easy-adhesion layer control of the average primary particle size and the standard deviation of the average primary particle size.
Specifically, the polyurethane-based resin preferably comprises either one of a polyester polyol component and a polyether polyol component. It is preferable that the standard deviation is within the range of 5 to 30 nm.

[Configuration of optical film]
The optical film of the present invention has an easy-adhesion layer on at least one surface of the substrate.
Specifically, as shown in FIG. 1, the optical film 100 easily contains a polyurethane-based resin on one side of a substrate 101 containing a cycloolefin-based resin, that is, on the surface of the substrate 101 on the polarizer layer 400 side. It has an adhesive layer 102 .
Such an optical film 100 is suitably used for a polarizing plate 200 as described later. The polarizing plate 200 includes, for example, at least a polarizing plate protective film 300, a polarizer layer 400, an optical film 100, and an adhesive sheet 500, which are laminated in this order. It is preferable that the adhesive sheet 500 is arranged on the surface of the optical film 100 opposite to the easily adhesive layer 102 .

The thickness of the substrate is 49 μm or less, preferably in the range of 15 to 40 μm. The reason why the thickness is set to 49 μm or less is that there is a need to reduce the thickness of the film due to the recent trend toward larger displays.
In the present invention, the “substrate” refers to the casting film after stretching and drying the casting film on which the easy-adhesion layer is formed in the method for producing an optical film, which will be described later. Therefore, the "thickness of the base material" means the thickness of the base material which is the cast film after stretching and drying, and refers to the thickness of the base material in the state of the optical film.

1. Easy-Adhesion Layer The easy-adhesion layer according to the present invention is provided on at least the surface on which the polarizer layer is provided, of the two surfaces of the substrate. When the optical film has the easy-adhesion layer, it is possible to improve the adhesion between the optical film and the polarizer layer described below.
The easy-adhesion layer according to the present invention contains a polyurethane-based resin. Moreover, it is preferable that the easy-adhesion layer contains microparticles|fine-particles.

1-1. Polyurethane-Based Resins Polyurethane-based resins are reaction products of one or more polyol components and one or more diisocyanate components.
The one or more polyol components are selected from polyester polyols, polyether polyols, polycarbonate polyols, polycaprolactone polyols, and the like, and preferably at least one of polyester polyols and polyether polyols.

For the one or more diisocyanate components, it is desirable to use a mixture of one or more diisocyanates and one or more triisocyanates. Desirably, no more than about 10 weight percent triisocyanate component is used with the diisocyanate, based on the total weight of the reaction components.

(polyester polyol)
The polyester polyol used in the present invention usually has two or more ester bonds and two or more hydroxy groups in the molecule.
Examples of polyester polyols include polyester polyols obtained by a condensation reaction between a polyhydric alcohol and a polybasic acid. Here, the polyhydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, and 1,6-hexane. Diol, 3,3′-dimethylolheptane, 1,4-cyclohexanedimethanol, neopentyl glycol, 3,3-bis(hydroxymethyl)heptane, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, etc. These may be used alone or in combination of two or more. Examples of polybasic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, orthophthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. These may be used singly or in combination of two or more.

Specific examples include polyester polyols such as polyethylene adipate diol, polybutylene adipate diol, and polyethylene succinate diol.
For polyester polyols, the number average molecular weight (Mn) is preferably 400-2000, more preferably 500-1500, most preferably 600-1200. Number average molecular weight (Mn) can be measured by conventional gel permeation chromatography (GPC).

These polyester polyols are commercially available as reagents or industrially. Examples of commercially available products include the "Polylight (registered trademark)" series manufactured by DIC Corporation, and the "Nipporan (registered trademark)" manufactured by Tosoh Corporation. series, "Maximol (registered trademark)" series manufactured by Kawasaki Kasei Co., Ltd., and the like.

(polyether polyol)
The polyether polyol used in the present invention is generally a hydroxy compound having one or more ether bonds in the main skeleton in the molecule. The repeating unit in the main skeleton may be either a saturated hydrocarbon or an unsaturated hydrocarbon, and may be linear, branched or cyclic.

Examples of the repeating units include 1,2-ethylene glycol units, 1,2-propylene glycol units, 1,3-propanediol (trimethylene glycol) units, 2-methyl-1,3-propanediol units, 2 , 2-dimethyl-1,3-propanediol units, 1,4-butanediol (tetramethyl glycol) units, 2-methyl-1,4-butanediol units, 3-methyl-1,4-butanediol units , 3-methyl-1,5-pentanediol units, neopentyl glycol units, 1,6-hexanediol units, 1,7-heptanediol units, 1,8-octanediol units, 1,9-nonanediol units, Examples include 1,10-decanediol units and 1,4-cyclohexanedimethanol units.

Among the polyether polyols having these repeating units in the main skeleton, polytetramethylene ether glycol, polytrimethylene ether glycol, copolymerized polyether polyols obtained by reacting 1 to 20 mol % of 3-methyltetrahydrofuran with tetrahydrofuran (For example, "PTG-L1000", "PTG-L2000" and "PTG-L3500" manufactured by Hodogaya Chemical Industry Co., Ltd.), and copolymerized polyether glycol obtained by the reaction of neopentyl glycol and tetrahydrofuran, poly(oxy Propylene ether) polyol and the like are preferred.

In addition, these polyether polyols can be used alone or in combination of two or more, and can be selected according to the desired physical properties of the polyurethane.

The number average molecular weight (Mn) of the polyether polyol used in the present invention is preferably 500 or more, more preferably 1000 or more, and even more preferably 1500 or more. Also, it is preferably 5,000 or less, more preferably 4,000 or less, and even more preferably 3,500 or less.

(polycarbonate polyol)
The polycarbonate polyol used in the present invention is preferably a polycarbonate diol.
A polycarbonate diol is a polycarbonate diol having two hydroxy groups in its molecule, and can be obtained, for example, by reacting a diol compound with a carbonate compound.
Examples of the carbonate compound include dimethyl carbonate and diphenyl carbonate.

The alkylene group-containing polycarbonate diol is a polycarbonate diol having two hydroxy groups in its molecule, and can be obtained, for example, by reacting a diol compound with ethylene carbonate.
Diol compounds include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,3-propanediol, 3-methyl-1, Linear or branched chain alkanediols such as 5-pentanediol, 2-ethyl-1,6-hexanediol, and 2,4-dimethyl-1,5-pentanediol and the like can be mentioned. In addition to these alkylene groups, it may be a diol compound containing an alicyclic structure, an aromatic ring structure, or both in its skeleton. The diol compound-derived portion in the urethane portion of the copolymer may be any one of the above diol compounds, or two or more thereof may be used in combination.

(polycaprolactone polyol)
A polyol having a lactone in the molecule can be produced by ring-opening polymerization of the following lactones, and the content ratio of the polylactone unit can be easily changed by changing the amount of lactone used relative to the polyol.

Lactones include, for example, ε-caprolactone, 4-methylcaprolactone, 3,5,5-trimethylcaprolactone, 3,3,5-trimethylcaprolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, γ- valerolactone, enantholactone, and the like. These may be used alone or in combination of two or more. ε-Caprolactone is most preferred due to its availability and high reactivity.

(Diisocyanate component)
In the present invention, aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, aromatic diisocyanate compounds, and mixtures thereof are used as the diisocyanate component. Among these, it is preferable to use an aliphatic diisocyanate compound and/or an alicyclic diisocyanate compound from the viewpoint of weather resistance. For the same reason, 30 to 100% by mass, particularly 50 to 100% by mass of the diisocyanate compound is preferably an aliphatic diisocyanate compound.

Examples of diisocyanate compounds that can be suitably used in the present invention include tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, octamethylene-1,8-diisocyanate, 2,2,4-trimethylhexane- Aliphatic diisocyanate compounds such as 1,6-diisocyanate;
cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 2,4-methylcyclohexyl diisocyanate, 2,6-methylcyclohexyl diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 4,4' - isomeric mixture of methylenebis(cyclohexyl isocyanate), hexahydrotoluene-2,4-diisocyanate, hexahydrotoluene-2,6-diisocyanate, hexahydrophenylene-1,3-diisocyanate, hexahydrophenylene-1,4-diisocyanate , 1,9-diisocyanato-5-methylnonane, 1,1-bis(isocyanatomethyl)cyclohexane, 2-isocyanato-4-[(4-isocyanatocyclohexyl)methyl]-1-methylcyclohexane, 2-(3- alicyclic diisocyanate compounds such as isocyanatopropyl)cyclohexyl isocyanate and norbornane diisocyanate;
Phenylcyclohexylmethane diisocyanate, isomeric mixture of 4,4'-methylenebis(phenylisocyanate), toluene-2,3-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate (TDI), phenylene-1 ,3-diisocyanate, phenylene-1,4-diisocyanate, 1,3-bis(isocyanatomethyl)benzene, xylylene diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate, 1,3-diisocyanatomethylbenzene , 4,4′-diisocyanato-3,3′-dimethoxy(1,1′-biphenyl), 4,4′-diisocyanato-3,3′-dimethylbiphenyl, 1,2-diisocyanatobenzene, 1,4 -bis(isocyanatomethyl)-2,3,5,6-tetrachlorobenzene, 2-dodecyl-1,3-diisocyanatobenzene, 1-isocyanato-4-[(2-isocyanatocyclohexyl)methyl]2- Aromatic diisocyanate compounds such as methylbenzene, 1-isocyanato-3-[(4-isocyanatophenyl)methyl)-2-methylbenzene, 4-[(2-isocyanatophenyl)oxy]phenylisocyanate, diphenylmethane diisocyanate, etc. can be mentioned.

Among these, from the viewpoint of good adhesive strength, heat resistance, and coatability, as described above, 30 to 100% by mass of the diisocyanate compound, particularly 50 to 100% by mass, is an aliphatic diisocyanate compound, and an alicyclic It is preferably at least one diisocyanate compound selected from the group consisting of diisocyanate compounds. Specific examples of suitable compounds include tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, octamethylene-1,8-diisocyanate, 2,2,4-trimethylhexane-1,6- diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 2,4-methylcyclohexyl diisocyanate, 2,6-methylcyclohexyl diisocyanate, isophorone diisocyanate, norbornane diisocyanate, 4, Isomer mixture of 4′-methylenebis(cyclohexyl isocyanate), hexahydrotoluene-2,4-diisocyanate, hexahydrotoluene-2,6-diisocyanate, hexahydrophenylene-1,3-diisocyanate, hexahydrophenylene-1,4 - include diisocyanates. These isocyanate compounds may be used alone or in combination of two or more.

In addition, a part of the NCO group of the diisocyanate compound may be modified to urethane, urea, buret, allophanate, carbodiimide, oxazolidone, amide, imide, etc. Further, the polynuclear compound contains isomers other than the above. It also includes those that are

The amount of these diisocyanate compounds to be used is preferably 0.1 to 5 equivalents with respect to 1 equivalent of the total hydroxy groups of the polyol and the hydroxy groups and/or amino groups of the chain extender described later. , more preferably 0.8 to 2 equivalents, still more preferably 0.9 to 1.5 equivalents, most preferably 0.95 to 1.2 equivalents, and 0.98 to 1.5 equivalents. One equivalent is particularly preferred.

By setting the amount of the diisocyanate compound used to 5 equivalents or less, unreacted isocyanate groups are prevented from causing unfavorable reactions, making it easier to obtain desired physical properties. Moreover, by setting the equivalent weight to 0.1 equivalent or more, the molecular weight of the polyurethane can be sufficiently increased, and the desired performance can be easily exhibited.

(chain extender)
Chain extenders used in the production of the polyurethane according to the present invention are mainly classified into compounds having two or more hydroxy groups, compounds having two or more amino groups, and water. Among these, short-chain polyols, specifically compounds having two or more hydroxy groups, are preferred for polyurethane production. These chain extenders may be used alone or in combination of two or more.

Examples of the compound having two or more hydroxy groups include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 2-methyl-1,3- propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, 1, 2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1, 5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2, Aliphatic glycols such as 5-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol and 1,9-nonanediol, alicyclic glycols such as bishydroxymethylcyclohexane, and xylylene glycol and glycols having an aromatic ring such as bishydroxyethoxybenzene.

Examples of compounds having two or more amino groups include aromatic diamines such as 2,4- or 2,6-tolylenediamine, xylylenediamine and 4,4'-diphenylmethanediamine, ethylenediamine, 1, 2-propylenediamine, 2,2-dimethyl-1,3-propanediamine, 1,3-pentanediamine, 2-methyl-1,5-pentanediamine, 2-butyl-2-ethyl-1,5-pentanediamine , 1,6-hexanediamine, 2,2,4- or 2,4,4-trimethylhexanediamine, 1,8-octanediamine, 1,9-nonanediamine and 1,10-decanediamine, such as aliphatic diamines, and 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (IPDA), 4,4'-dicyclohexylmethanediamine (hydrogenated MDA), isopropylidenecyclohexyl-4,4'-diamine, 1,4 cycloaliphatic diamines such as -diaminocyclohexane and 1,3-bisaminomethylcyclohexane. Among these, ethylenediamine, propylenediamine, 1,3-pentanediamine and 2-methyl-1,5-pentanediamine are preferred.

The amount of these chain extenders to be used is usually 0.1 to 5.0 equivalents, preferably 0.8 to 2, when the equivalent weight obtained by subtracting the equivalent weight of the isocyanate compound from the hydroxyl group equivalent weight of the polyol is 1. 0.0 equivalent is more preferred, and 0.9 to 1.5 equivalent is even more preferred.

By setting the amount of the chain extender to the above upper limit or less, it is possible to prevent the obtained polyurethane from becoming too hard and obtain desired properties, and it is easily soluble in a solvent and easy to process. In addition, by setting the above lower limit or more, sufficient strength, elastic recovery performance, and elastic retention performance can be obtained without being too soft, and good high-temperature characteristics can be obtained.

(manufacturing of polyurethane)
In the present invention, the polyol, the isocyanate compound, and the chain extender are used as the main raw materials for the production of the polyurethane in the amounts described above. Depending on the method, it can be carried out in the absence of a solvent or in the presence of a solvent.

The solvent used at that time is not particularly limited, but from the viewpoint of versatility and solubility, N,N-dimethylacetamide and N,N-dimethylformamide, mixtures of two or more thereof, etc. Amide solvent: A solvent selected from the group consisting of N-methylpyrrolidone, N-ethylpyrrolidone and dimethylsulfoxide is preferably used, and among these, N,N-dimethylformamide and N,N-dimethylacetamide are particularly preferred.

The content of the polyurethane-based resin is preferably in the range of 65-95% by mass with respect to the easy-adhesion layer.

1-2. Fine Particles The easy-adhesion layer according to the present invention preferably contains fine particles. The microparticles can be inorganic microparticles or organic microparticles.
Examples of inorganic fine particles include fine particles of inorganic oxides such as silica, titania, alumina, and zirconia; fine particles such as
Examples of organic fine particles include fine particles of silicone resin, fluororesin, (meth)acrylic resin, and the like.
Among these, silica particles are preferable because they hardly cause haze and are less colored.

The average primary particle size of the silica fine particles is preferably in the range of 50-150 nm, more preferably in the range of 80-120 nm.
Also, the standard deviation of the average primary particle size is preferably within the range of 5 to 30 nm, more preferably within the range of 5 to 10 nm.

The average primary particle size and standard deviation are calculated as follows.
After trimming the cross-section of the optical film of the present invention with a microtome or the like, an ultra-thin section of the cross-section is prepared, and the cross-section is photographed with a transmission electron microscope (TEM) or a scanning electron microscope (SEM). Bright-field image observation is performed by the method of direct photography.
In a bright-field image taken with an electron microscope, the scattering intensity of incident electrons in a substance to be observed is proportional to the atomic number (atomic weight) of the substance. In the present invention, inorganic particles composed of atoms with a large atomic number, such as Si atoms, exhibit a dark contrast, and rubber particles composed of atoms with a small atomic number, such as C atoms, exhibit a bright contrast. indicates Thereby, silica particles in the optical film can be confirmed.
From the obtained image, the area equivalent circle diameter (Di; i = 1 to 100) of at least 100 silica fine particles was obtained, and the average primary particle diameter D of the silica fine particles and its standard deviation s were calculated by the following formula using the number average value. calculate.
As an electron microscope, for example, a TEM (JEM2010F, manufactured by JEOL Ltd.) can be used.

The content of silica fine particles is preferably in the range of 5 to 10% by mass with respect to the easy-adhesion layer.

1-3. Additives The easy-adhesion layer according to the present invention preferably further contains additives. As the additive, a cross-linking agent is preferable in order to improve adhesiveness. Moreover, various acids and bases may be contained in order to adjust the pH of the easy-adhesion layer.

The cross-linking agent used in the present invention is not particularly limited as long as it can form an easy-adhesion layer with excellent reworkability. compounds, water-based amino compounds, water-based carbodiimide compounds, and water-based aldehyde compounds are preferred. In particular, it is preferable to use a water-based epoxy compound or a water-based amino compound.

Oxazoline-based additives and nitrogen-containing heterocyclic compounds are also suitable for adjusting the pH of water-based adhesives. Among them, nitrogen-containing heterocyclic compounds are highly alkaline, so they are useful for adjusting the pH of the water-based adhesive to an appropriate range, and are effective in increasing the durability of the easy-adhesion layer through a cross-linking reaction.
These cross-linking agents may be used alone or in combination.

(Isocyanate additive)
The isocyanate-based additive according to the present invention is preferably a water-soluble or emulsified compound having two or more unblocked isocyanate groups or blocked isocyanate groups.

Examples of non-blocked isocyanate compounds include compounds obtained by reacting polyfunctional isocyanate compounds with monovalent or polyvalent nonionic polyalkylene ether alcohols. Examples of blocked isocyanate compounds include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4′-diphenylmethane diisocyanate (MDI), xylylene diisocyanate isocyanate (XDI), isophorone diisocyanate (IPDI), methylcyclohexyl diisocyanate (H6TDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI), tetramethylxylylene diisocyanate (TMXDI), 2,2,4-trimethylhexamethylene diisocyanate (TMHDI), hexamethylene diisocyanate (HDI), norbornene diisocyanate (NBDI), 2,4,6-triisopropylphenyl diisocyanate (TIDI), 1,12-diisocyanate dodecane (DDI), 2,4,-bis-(8-isocyanatooctyl)-1,3-dioctylcyclobutane (OCDI), n-pentane-1,4-diisocyanate and their isocyanurate modified products, adduct modified products, Burette-modified products, allophanate-modified products, these polymers having one or more isocyanate groups are modified with polyoxyalkylene groups, carboxy groups, etc. to make them water-soluble and/or water-dispersible, and isocyanate groups are blocked with blocking agents ( phenol, ε-caprolactam, etc.).

(Oxazoline additive)
The oxazoline additive according to the present invention is preferably an oxazoline group-containing polymer. The oxazoline group-containing polymer is a polymer having an oxazoline group in its molecule, preferably a polymer having an oxazoline group in its side chain. The main chain of the polymer is not particularly limited, and is composed of, for example, one or more skeletons selected from (meth)acrylic skeletons, styrene skeletons, and the like.

A preferable example of the oxazoline group-containing polymer is an oxazoline group-containing (meth)acrylic polymer containing a main chain composed of a (meth)acrylic skeleton and having an oxazoline group in the side chain of the main chain.

When the oxazoline group-containing polymer has an oxazoline group in a side chain, a linking group may be interposed between the main chain and the oxazoline group, but the main chain and the oxazoline group are preferably directly bonded.

The oxazoline group includes, for example, 2-oxazoline group, 3-oxazoline group, 4-oxazoline group and the like, and 2-oxazoline group and the like are preferable.

The number average molecular weight of the oxazoline group-containing polymer is preferably 5,000 or more, more preferably 10,000 or more. When the number average molecular weight is within the above range, good adhesion is exhibited. The number average molecular weight of the oxazoline group-containing polymer is usually 100,000 or less.
The number average molecular weight of the oxazoline group-containing polymer can be measured as a standard polystyrene conversion value by gel permeation chromatography (GPC).

The oxazoline group content of the oxazoline group-containing polymer (the number of moles of oxazoline groups per gram of solid content of the oxazoline group-containing polymer (A)) is preferably 0.4 mmol/g·solid or more and 10 mmol/g·solid or less. If the oxazoline group content is excessively high, it is difficult to obtain good adhesion, and if the oxazoline group content is less than the above range, the water resistance of the easy-adhesion layer may decrease. From such a viewpoint, the oxazoline group content of the oxazoline group-containing polymer (A) is more preferably 3 mmol/g·solid or more and 9 mmol/g·solid or less.

The oxazoline group-containing polymer is preferably a water-based polymer, that is, a water-soluble polymer, or a water-dispersible polymer. From the viewpoint of the optical properties of the easy adhesion layer, the oxazoline group-containing polymer is preferably a water-soluble polymer.

A commercially available product may be used as the oxazoline group-containing polymer. Specifically, Nippon Shokubai Co., Ltd. Epocross WS-300, Epocross WS-500, Epocross WS-700 (all trade names) and other oxazoline group-containing acrylic polymers; Nippon Shokubai Co., Ltd. Epocross K-1000 series, Epocross Examples include oxazoline group-containing acrylic/styrene polymers such as K-2000 series and Epocross RPS series (both trade names).

Two or more kinds of oxazoline group-containing polymers can be used in combination.
Oxazoline group-containing acrylic polymers such as Epocross WS-300 and Epocross WS-700 are preferred from the viewpoint of adhesion, optical properties and water resistance.

(Nitrogen-containing heterocyclic compound)
A nitrogen-containing heterocyclic compound is a compound having a cyclic structure (nitrogen-containing heterocyclic structure) in which at least one of the carbon atoms constituting the ring of a cyclic hydrocarbon structure is replaced with a nitrogen atom. The nitrogen-containing heterocyclic structure may be monocyclic or polycyclic such as condensed ring. A nitrogen-containing heterocyclic compound functions as a cross-linking agent, and can also be used for the purpose of adjusting the pH value.

The nitrogen-containing heterocyclic compound may have only one nitrogen-containing heterocyclic structure in the molecule, or may have two or three or more nitrogen-containing heterocyclic structures. When the nitrogen-containing heterocyclic compound has a plurality of nitrogen-containing heterocyclic structures in its molecule, the nitrogen-containing heterocyclic structures may have the same structure or different structures. When a compound having a plurality of nitrogen-containing heterocycles is used, the cross-linking reaction strengthens the water-based adhesive layer, making it possible to improve the durability.
When the nitrogen-containing heterocyclic compound has multiple nitrogen-containing heterocyclic structures in its molecule, the nitrogen-containing heterocyclic structures preferably have the same structure.

Nitrogen-containing heterocyclic structures include, for example, aziridine structure, azirine structure, azetidine structure, 1,2-oxazetidine structure, 1,3-oxazetidine structure, 1,2-thiazetidine structure, 1,3-thiazetidine structure, 1,2 -Dihydroazate structure, 1,3-diazate structure, pyrrolidine structure, pyrroline structure, imidazolidine structure, imidazoline structure, pyrazolidine structure, pyrazoline structure, oxazoline structure, thiazoline structure, pyrrole structure, pyrazole structure, imidazole structure, oxazole structure, isoxazole structure, thiazole structure, thiadiazole structure, isothiazole structure, 1,2,3-triazole structure, 1,2,4-triazole structure, tetrazole structure, 1,3,4-oxadiazole structure, furazane structure, pyridine structure, monocyclic structures such as pyridazine structure, pyrimidine structure, pyrazine structure, piperazine structure, piperidine structure, morpholine structure, thiazine structure, piperidone structure, triazine structure, oxazine structure, tetrazine structure;
polycyclic structures such as benzimidazole, benzotriazole, benzoxazole, benzothiazole, quinolidine, indolizine, indole, quinoline, isoquinoline, benzotriazine, tetrazaindene, and purine;

The nitrogen-containing heterocyclic structure can have one or more substituents bonded to the ring structure. Examples of substituents include hydrocarbon groups having about 1 to 12 carbon atoms (for example, alkyl groups).

The nitrogen-containing heterocyclic compound is preferably a compound having a structure capable of forming a crosslinked structure with an oxazoline group-containing polymer or an optical film as a protective layer. If the nitrogen-containing heterocyclic compound can form a crosslinked structure with the oxazoline group-containing polymer or optical film, it exhibits good adhesion.

The structure capable of forming a crosslinked structure with the oxazoline group-containing polymer or optical film (hereinafter sometimes referred to as "crosslinkable structure (1)") is not particularly limited. The crosslinkable structure (1) may be any structure capable of forming a crosslinked structure with a functional group such as a hydroxy group or a carboxyl group, and may be the nitrogen-containing heterocyclic structure itself.

Examples of such a nitrogen-containing heterocyclic structure include an oxazoline ring and an aziridine ring, and from the viewpoint of adhesion, an aziridine ring is preferred.
The nitrogen-containing heterocyclic compound preferably has two or more crosslinkable structures (1), more preferably two or more nitrogen-containing heterocyclic structures as the crosslinkable structures (1), and has two aziridine rings. It is more preferable to have one or more.

Nitrogen-containing heterocyclic compounds are usually non-polymers. The molecular weight of the nitrogen-containing heterocyclic compound is generally within the range of 41-2,000. The molecular weight of the nitrogen-containing heterocyclic compound may be 1,500 or less, or 1,000 or less.

The content of the nitrogen-containing heterocyclic compound in the aqueous resin composition is usually in the range of 0.1 to 50 parts by mass, preferably 0.2 to 100 parts by mass, relative to 100 parts by mass of the oxazoline group-containing polymer (A). 30 parts by mass, more preferably 0.5 to 20 or less. When the content of the nitrogen-containing heterocyclic compound is within this range, good adhesion tends to be exhibited.

The nitrogen-containing heterocyclic compound preferably has a crosslinkable structure (1) at its terminal, and more preferably has an aziridine ring at its terminal.
Nitrogen-containing heterocyclic compounds include diphenylmethane-4,4′-bis(1-aziridinecarboxamide), toluene-2,4-bis(1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1-(2 -methylaziridine), tris-1-aziridinylphosphine oxide, hexamethylene-1,6-bis(1-aziridinecarboxamide), trimethylolpropane tris-β-aziridinylpropionate, tetramethylolmethane tris-β -aziridinyl propionate, piperidine, 4-picoline, 3,5-diethylpyridine, 1,4-bis(3-aminopropyl)piperazine, and formula (B1) described in JP-A-2018-199756 -1) to the compound represented by formula (B1-4).

Nitrogen-containing heterocyclic compounds may be commercially available products, specifically, Chemitite PZ-33 and Chemitite DZ-22E (both trade names) manufactured by Nippon Shokubai Co., Ltd.; Crosslinker CL-422 and Crosslinker CL manufactured by Menadiona. -427, CROSSLINKER CL-467 (both trade names) and other aziridine compounds. In particular, CROSSLINKER CL-427 and CROSSLINKER CL-467 are preferable from the viewpoint of adhesion.

(Water-based epoxy compound)
The water-based epoxy compound may be a compound having two or more epoxy groups that are soluble in water or emulsified. For example, 1 mol of glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexane glycol and neopentyl glycol and 2 mol of epichlorohydrin Diepoxy compounds obtained by etherification; polyepoxy compounds obtained by etherification of 1 mol of polyhydric alcohols such as glycerin, polyglycerin, trimethylolpropane, pentaerythritol and sorbitol with 2 mol or more of epichlorohydrin; phthalic acid, terephthalic acid , a diepoxy compound obtained by esterifying 1 mol of a dicarboxylic acid such as oxalic acid and adipic acid with 2 mol of epichlorohydrin; and the like.

Specific examples include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin or triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline and diglycidylamine.
Examples of commercially available water-based epoxy compounds include Deconal EX-521 (manufactured by Nagase ChemteX Corporation).

(Aqueous amino compound)
The water-based amino compound may be a compound having two or more amino groups that are soluble in water or emulsified. For example, amines such as ethylenediamine, triethylenediamine, hexamethylenediamine, carbodihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide , glycolic acid dihydrazide, polyacrylic acid dihydrazide, etc.; resin, urea resin, guanamine resin, and the like.

(Aqueous carbodiimide compound)
The aqueous carbodiimide compound may be a compound that is soluble in water or has two or more emulsified carbodiimide bonds (-N=C=N-). A compound having two or more carbodiimide bonds is obtained by a method of forming -N=C=N- by decarboxylating two isocyanate groups using two or more molecules of polyisocyanate and a carbodiimidation catalyst. be able to. The polyisocyanate and carbodiimidation catalyst used when synthesizing a compound having two or more carbodiimide bonds are not particularly limited, and conventionally known ones can be used.

(Compound having an aldehyde group)
Examples of the compound having an aldehyde group include monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, crotonaldehyde, benzaldehyde and formaldehyde, dialdehydes such as glyoxal, malondialdehyde, glutaraldehyde and terephthalaldehyde, dialdehyde starch, and acrolein. A copolymerized acrylic resin and the like can be mentioned.

The easy adhesion layer according to the present invention is formed by mixing the polyurethane-based resin and fine particles, and optionally the additive (for example, a water-based epoxy compound, a water-based amino compound, etc.) and a water-soluble solvent to obtain a liquid water-based resin. It is preferable to apply the composition to at least one surface of the optical film.
Examples of the water-soluble solvent include methanol, ethanol, isopropyl alcohol, acetone, tetrahydrofuran, N-methylpyrrolidone, dimethylsulfoxide, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether and the like. Among them, it is preferable to use water as the water-soluble solvent. In addition, one type of water-soluble solvent may be used alone, or two or more types may be used in combination at an arbitrary ratio.
The amount of the water-soluble solvent is preferably set so that the viscosity of the uncured urethane resin is within a range suitable for coating.
Further, the content of the polyurethane resin in the aqueous resin composition is preferably in the range of 65 to 95% by mass, and the content of the silica fine particles in the aqueous resin composition is 5 to 10% by mass. is preferably within the range of Moreover, the content of the additive in the aqueous resin composition is preferably within the range of 0.1 to 10% by mass.

The thickness of the easy-adhesion layer is preferably in the range of 20-2000 nm.
The "thickness of the easy-adhesion layer" is the thickness of the easy-adhesion layer after stretching and drying the casting film coated with the coating material of the easy-adhesion layer, and is the thickness of the easy-adhesion layer in the state of the optical film. It refers to the thickness of the easy-adhesion layer.

2. Substrate The substrate according to the present invention contains a cycloolefin resin. Moreover, the substrate may contain an ultraviolet absorber, an antioxidant, and other components described later.

2-1. Cycloolefin Resin The cycloolefin resin is a polymer of a cycloolefin monomer or a copolymer of a cycloolefin monomer and another copolymerizable monomer.

The cycloolefin monomer is preferably a cycloolefin monomer having a norbornene skeleton.
In particular, a cycloolefin monomer having a structure represented by general formula (A-1) or (A-2) below is more preferred.

R ¹ to R ⁴ in general formula (A-1) each independently represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a polar group. However, except when all of R ¹ to R ⁴ are hydrogen atoms, there is no case where R ¹ and R ² are hydrogen atoms at the same time, or R ³ and R ⁴ are hydrogen atoms at the same time.

The hydrocarbon group having 1 to 30 carbon atoms is preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 5 carbon atoms. The hydrocarbon group having 1 to 30 carbon atoms may further have a linking group containing a halogen atom, oxygen atom, nitrogen atom, sulfur atom or silicon atom. Examples of such linking groups include divalent polar groups such as carbonyl groups, imino groups, ether bonds, silyl ether bonds and thioether bonds. Examples of hydrocarbon groups having 1 to 30 carbon atoms include methyl group, ethyl group, propyl group, butyl group and the like.

Examples of polar groups include carboxy groups, hydroxy groups, alkoxy groups, alkoxycarbonyl groups, allyloxycarbonyl groups, amino groups, amido groups and cyano groups. Among them, a carboxy group, a hydroxy group, an alkoxycarbonyl group and an aryloxycarbonyl group are preferred, and an alkoxycarbonyl group and an aryloxycarbonyl group are preferred from the viewpoint of ensuring solubility during solution film formation.

p in general formula (A-1) represents an integer of 0 to 2. Preferably, p is 1 or 2.

R ⁵ in general formula (A-2) represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. Among them, a hydrocarbon group having 1 to 5 carbon atoms is preferable, and a hydrocarbon group having 1 to 3 carbon atoms is more preferable.

R ⁶ in general formula (A-2) is a hydrogen atom, a carboxy group, a hydroxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amido group, a cyano group, or a halogeno group (fluoro, chloro, bromo group, or iodine group). Among them, a carboxy group, a hydroxy group, an alkoxycarbonyl group and an aryloxycarbonyl group are preferred, and an alkoxycarbonyl group and an aryloxycarbonyl group are more preferred from the viewpoint of ensuring solubility during solution film formation.

p in general formula (A-2) represents an integer of 0 to 2. Preferably, p is 1 or 2.

The cycloolefin monomer represented by general formula (A-2) has an asymmetric structure. That is, since the substituents R ⁵ and R ⁶ of the cycloolefin monomer represented by general formula (A-2) are substituted only on one ring-constituting carbon atom with respect to the symmetry axis of the molecule, low symmetry. Such cycloolefin monomers can promote the diffusion and transfer of ultraviolet absorbers and antioxidants when drying the cast dope in the method for producing an optical film, which will be described later. It is thought that the distribution state can be easily adjusted.

Specific examples of the cycloolefin monomer represented by the general formula (A-1) are shown in Exemplary Compounds 1 to 14, and specific examples of the cycloolefin monomer represented by the general formula (A-2) are exemplary compounds. 15-34.

Examples of copolymerizable monomers copolymerizable with cycloolefin monomers include copolymerizable monomers capable of ring-opening copolymerization with cycloolefin monomers and copolymerizable monomers capable of addition copolymerization with cycloolefin monomers. A copolymerizable monomer is included.

Examples of copolymerizable monomers capable of ring-opening copolymerization include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene and dicyclopentadiene.

Examples of addition-copolymerizable copolymerizable monomers include unsaturated double bond-containing compounds, vinyl-based cyclic hydrocarbon monomers, and (meth)acrylates.
Examples of unsaturated double bond-containing compounds are olefinic compounds having 2 to 12 (preferably 2 to 8) carbon atoms, examples of which include ethylene, propylene, butenes.
Examples of vinyl-based cyclic hydrocarbon monomers include vinylcyclopentene-based monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of (meth)acrylates include alkyl (meth)acrylates having 1 to 20 carbon atoms such as methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and cyclohexyl (meth)acrylate.

As described above, the cycloolefin resin is a cycloolefin monomer having a norbornene skeleton, preferably a cycloolefin monomer having a structure represented by general formula (A-1) or (A-2), polymerized or Polymers obtained by copolymerization, examples of which include the following.
(1) A ring-opening polymer of a cycloolefin monomer (2) A ring-opening copolymer of a cycloolefin monomer and a copolymerizable monomer capable of ring-opening copolymerization thereof (3) Above (1) or (2) Hydrogenated product of the ring-opening (co)polymer (4) The ring-opening (co)polymer of (1) or (2) above was cyclized by the Friedel-Crafts reaction and then hydrogenated (co- ) Polymers (5) Saturated copolymers of cycloolefin monomers and unsaturated double bond-containing compounds (6) Addition copolymers of cycloolefin monomers and vinyl cyclic hydrocarbon monomers, and Hydrogenated product thereof (7) Alternating copolymer of cycloolefin-based monomer and (meth)acrylate

Among them, (1) to (3) are preferable, and (3) is more preferable. That is, the cycloolefin-based resin can increase the glass transition temperature and light transmittance of the obtained cycloolefin-based resin with a structural unit represented by the following general formula (B-1). It preferably contains at least one structural unit represented by the following general formula (B-2). The structural unit represented by general formula (B-1) is a structural unit derived from the cycloolefin monomer represented by general formula (A-1) described above, and is represented by general formula (B-2). is a structural unit derived from the cycloolefin monomer represented by the general formula (A-2) described above.

X in general formula (B-1) is -CH=CH- or -CH ₂ CH ₂ -.

R ¹ to R ⁴ and p in general formula (B-1) are synonymous with R ¹ to R ⁴ and p in general formula (A-1), respectively.

X in general formula (B-2) is -CH=CH- or -CH ₂ CH ₂ -.

R ⁵ to R ⁶ and p in general formula (B-2) are synonymous with R ⁵ to R ⁶ and p in general formula (A-2), respectively.

As the cycloolefin-based resin described above, commercially available products can be preferably used, and examples of commercially available products include JSR Corporation's Arton (registered trademark) G series, It is marketed under the trade name of the RX series, and Zeonor (registered trademark) ZF14, ZF16, 1420R, 1020R, 1060R, etc., and Zeonex (registered trademark) 250, 280, 480, 480R from Nippon Zeon Co., Ltd. , E48R, F52R, 330R, RS420, etc., and these can be appropriately selected and used depending on the application.

The cycloolefin-based resins can all be obtained by known methods, for example, the methods described in JP-A-2008-107534, JP-A-2005-227606 and JP-A-4466272.

The intrinsic viscosity [η]inh of the cycloolefin resin is preferably in the range of 0.2 to 5 cm ³ /g, more preferably in the range of 0.3 to 3 cm ³ /g, and 0.3 cm 3 /g. More preferably, it is in the range of 4 to 1.5 cm ³ /g.

The number average molecular weight (Mn) of the cycloolefin resin is preferably 8,000 to 100,000, more preferably 10,000 to 80,000, even more preferably 12,000 to 50,000. The weight average molecular weight (Mw) of the cycloolefin resin is preferably from 20,000 to 300,000, more preferably from 30,000 to 250,000, even more preferably from 40,000 to 200,000. The number average molecular weight and weight average molecular weight of the cycloolefin resin can be measured by gel permeation chromatography (GPC) in terms of polystyrene.

When the intrinsic viscosity [η] inh, the number average molecular weight and the weight average molecular weight are within the above ranges, the cycloolefin resin has good heat resistance, water resistance, chemical resistance, mechanical properties, and moldability as a film. .

The glass transition temperature (Tg) of the cycloolefin resin is usually 110°C or higher, preferably in the range of 110 to 350°C, more preferably 120 to 250°C, and 120 to 220°C. It is more preferable to be within the range. When Tg is 110°C or higher, deformation under high temperature conditions is easily suppressed. On the other hand, when the Tg is 350° C. or less, the molding process becomes easy, and deterioration of the resin due to heat during the molding process can be easily suppressed.

The content of the cycloolefin resin is preferably 70% by mass or more, more preferably 80% by mass or more, relative to the optical film.

2-2. Ultraviolet Absorber The ultraviolet absorber is added for the purpose of improving the durability of the optical film. Such an ultraviolet absorber is preferably a compound that absorbs ultraviolet rays of 400 nm or less. Specifically, the transmittance of light having a wavelength of 370 nm is 10% or less, preferably 5% or less, more preferably 2%. It is the following compound.

Examples of UV absorbers include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, inorganic powders, and polymeric UV absorbers. drug is included. One type of ultraviolet absorber may be used, or two or more types may be used in combination.

Among them, benzotriazole-based compounds, benzophenone-based compounds, and triazine-based compounds are preferable, and benzotriazole-based compounds and benzophenone-based compounds are more preferable, because they have good ultraviolet absorption ability.

Examples of benzotriazole compounds include 5-chloro-2-(3,5-di-sec-butyl-2-hydroxylphenyl)-2H-benzotriazole, (2-2H-benzotriazol-2-yl)- 6-(Linear and side chain dodecyl)-4-methylphenol is included. Examples of benzophenone compounds include 2-hydroxy-4-benzyloxybenzophenone and 2,4-benzyloxybenzophenone.

Examples of commercially available products include Tinuvin series such as Tinuvin109, Tinuvin171, Tinuvin234, Tinuvin326, Tinuvin327, Tinuvin328, and Tinuvin928, all of which are commercially available products manufactured by BASF.

The content of the ultraviolet absorber (total content in the optical film) is preferably, for example, 0.1 to 10% by mass relative to the cycloolefin resin. If the content of the ultraviolet absorber is 0.1% by mass or more, the durability (particularly weather resistance) of the optical film can be sufficiently enhanced. If the content of the ultraviolet absorber is 10% by mass or less, the transparency of the optical film is less likely to be impaired. More preferably, the content of the ultraviolet absorber is 0.5 to 5% by mass.

2-3. Antioxidant (anti-degradation agent)
The antioxidant may be added for the purpose of suppressing deterioration of the optical film under high temperature and high humidity.
Examples of antioxidants include hindered phenolic compounds. Examples of hindered phenolic compounds include 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] , triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl- 4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, 2,2- thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N, N′-Hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t -butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanate, and the like. One type of antioxidant may be used, or two or more types may be used in combination.
Among them, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis [3 -(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] is preferred.

Antioxidants include hydrazine-based metal deactivators such as N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine and tris(2,4- It may be used in combination with a phosphorus-based processing stabilizer such as di-t-butylphenyl)phosphite.

The content of the antioxidant (total content in the optical film) is preferably, for example, within the range of 0.1 to 10% by mass relative to the cycloolefin resin. When the antioxidant content is 0.1% by mass or more, the durability (especially weather resistance) of the optical film can be sufficiently enhanced. If the content of the antioxidant is 10% by mass or less, the transparency of the optical film is less likely to be impaired. More preferably, the antioxidant content is in the range of 0.5 to 5% by mass.

At least one of the ultraviolet absorber and the antioxidant is preferably unevenly distributed on the surface of the optical film roughened by solvent treatment.

2-4. Other Components The optical film may further contain other additives as long as the effects of the present invention are not impaired. Examples of other additives include plasticizers, heat stabilizers, fine particles (matting agents), surfactants, fluorosurfactants, release aids, and the like.

(fine particles)
The fine particles can make the surface of the optical film uneven and improve the slipperiness. The microparticles can be inorganic microparticles or organic microparticles.
As the inorganic fine particles or organic fine particles, the same inorganic fine particles or organic fine particles as those contained in the easy-adhesion layer can be used.

The average particle size of the fine particles is preferably in the range of 1 to 500 nm, more preferably in the range of 5 to 300 nm. By setting the average particle size to 1 nm or more, the lubricating property of the easy-adhesion layer can be effectively improved, and by setting the average particle size to 500 nm or less, the haze can be kept low. The average particle size of the fine _particles is determined by measuring the particle size distribution by a laser diffraction method. .
The content of fine particles can be 10% by mass or less with respect to the optical film.

[Physical properties of optical film]
(Phase difference value)
Optical films can have various retardation values (also referred to as “retardation values”) depending on their uses. For example, when the optical film is used as an optical film for a VA mode or IPS mode liquid crystal display device, the in-plane direction retardation Ro and the thickness direction retardation Rth can satisfy, for example, the following relationship.
0 nm≦Ro≦300 nm
−200 nm≦Rth≦200 nm

The in-plane retardation Ro of the optical film more preferably satisfies 50≦Ro≦250 nm, and more preferably satisfies 50 nm≦Ro≦200 nm. The thickness direction retardation Rth of the optical film more preferably satisfies −150 nm≦Rth≦150 nm, and more preferably −120 nm≦Rth≦120 nm.

Ro and Rth of the optical film are defined by the following formulas.
Formula (2a): Ro = (n _x -n _y ) x d
Formula (2b): Rth=((n _x +n _y )/2−n _z )×d
(In the formula, nx represents the refractive index in the in-plane slow axis direction of the optical film. _ny represents the refractive index in the direction perpendicular to the in-plane slow axis of the optical film. _nz represents the optical film represents the refractive index in the thickness direction of d represents the thickness (nm) of the optical film.)

Ro and Rth of the optical film can be measured by the following methods.
(1) The optical film is conditioned at 23° C. and 55% RH for 24 hours. The average refractive index of this optical film is measured with an Abbe refractometer, and the thickness d is measured with a commercially available micrometer.
(2) Retardation Ro and Rth of the optical film after humidity control at a measurement wavelength of 590 nm are measured using an automatic birefringence meter AxoScanMuellerMatrixPolarimeter (manufactured by Axometrics), respectively, in an environment of 23°C and 55% RH. Measure below. in particular,
(i) Ro is measured by Axoscan when light with a measurement wavelength of 590 nm is incident parallel to the normal direction of the film surface.
(ii) Furthermore, by Axoscan, the in-plane slow axis of the sample piece is used as the tilt axis (rotation axis), and the angle θ with respect to the normal line of the surface of the sample piece (incident angle (θ)) from the measurement wavelength 590 nm A phase difference R(.theta.) was measured when the light of .theta. The phase difference R(θ) is measured at 6 points every 10° within the range of 0° to 50°. The in-plane slow axis of the sample piece is confirmed by Axoscan.
(iii) From the measured Ro and R (θ) and the average refractive index and thickness described above, Axoscan calculates n _x , _ny and _nz , and based on the above formula (2b), the measurement wavelength is 590 nm Calculate the Rth at

(thickness)
The thickness of the optical film (the total thickness of the substrate and the easy-adhesion layer) depends on the range of Ro and Rth required, but is preferably in the range of 15 to 60 μm, more preferably in the range of 15 to 40 μm. is more preferable.

[Method for producing optical film]
The optical film of the present invention can be produced by, for example, 1) preparing a dope containing the above cycloolefin resin and solvent, 2) casting the obtained dope on a support, drying and peeling, and casting. 3) applying a coating material for an easy-adhesion layer made of a polyurethane-based resin to the obtained cast film; and 4) stretching the cast film coated with the coating material. 5) It can be produced through a step of drying the stretched casting film and the coating material.
As described above, the coating material is applied to the casting film, stretched, and dried to form the casting film as the base material of the present invention and the coating material as the easy adhesion layer of the present invention. Thus, an optical film having an easy-adhesion layer on the substrate is produced.
After the step 5) of drying the cast film, the step of 6) cutting both ends of the obtained optical film and embossing them, 7) the step of forming a roughened surface on the optical film, and 8) It is preferable to go through a winding process.

Regarding step 1) (dope preparation step) A dope is prepared by dissolving or dispersing a cycloolefin resin in a solvent.

The solvent used for the dope contains at least an organic solvent (good solvent) capable of dissolving the cycloolefin resin. Examples of good solvents include chlorinated organic solvents such as methylene chloride; and non-chlorinated organic solvents such as methyl acetate, ethyl acetate, acetone and tetrahydrofuran. Among them, methylene chloride is preferred.

The solvent used for the dope may further contain a poor solvent. Examples of poor solvents include linear or branched aliphatic alcohols having 1 to 4 carbon atoms. When the ratio of alcohol in the dope becomes high, the film-like material tends to gel and is easily peeled off from the metal support. Examples of linear or branched aliphatic alcohols having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol and tert-butanol. Of these, ethanol is preferred because of its dope stability, relatively low boiling point, and good drying properties.

About the process of 2) (casting process) The obtained dope is cast on a support. Casting of the dope can be performed by discharging from a casting die.

The solvent is evaporated until the dope cast on the support can be peeled off from the support with a peel roll. Methods for evaporating the solvent include a method of exposing the cast dope to air, a method of transferring heat from the back surface of the support by a liquid, and a method of transferring heat from the front and back surfaces by radiant heat.

After that, the casting film obtained by evaporating the solvent is peeled off with a peeling roll.

The amount of solvent remaining in the cast film on the support after peeling depends on the drying conditions and the length of the support, but can be, for example, 50 to 120% by mass. If the film is peeled with a large amount of residual solvent, the cast film will be too soft, and the flatness of the film will be easily lost when peeled. is determined. The residual solvent amount is defined by the following formula.

Residual solvent amount (% by mass)=(mass of casting film before heat treatment−mass of casting film after heat treatment)/(mass of casting film after heat treatment)×100
The heat treatment for measuring the residual solvent amount is a heat treatment at 115° C. for 1 hour.

Regarding step 3) (easy-adhesion layer forming step) After the casting step and before the stretching step (that is, before stretching the cast film obtained by peeling from the support), the surface on which the easy-adhesion layer is formed is subjected to discharge treatment, and a coating material made of a polyurethane-based resin is applied to the surface of the discharge-treated side.
It is preferable to mix the polyurethane-based resin, optionally fine particles (silica fine particles), and an aqueous solvent, and apply the mixture as a liquid aqueous resin composition (coating material). Moreover, the content of the polyurethane resin in the aqueous resin composition is preferably within the range of 65 to 95% by mass.

About step 4) (stretching step) The casting film coated with the easy-adhesion layer is stretched.

The stretching may be performed according to the required optical properties, and it is preferable to stretch in one or more of the width direction (TD direction), the transport direction (MD direction), and the oblique direction. For example, when producing an optical film that functions as a λ/4 retardation film, stretching in an oblique direction is preferred.

The draw ratio depends on the desired optical properties, but for example, when used as a λ/4 retardation film, it is preferably in the range of 1.05 to 4.0 times, and 1.5 to 3.0 times. It is more preferable to be within the range.

The stretch ratio (times) is defined as the size in the stretching direction of the film after stretching/the size in the stretching direction of the film before stretching. In addition, when biaxially stretching, it is preferable to set it as the said draw ratio about each of TD direction and MD direction.

As described above, the stretching temperature (drying temperature during stretching) is preferably (Tg+2) to (Tg+50)° C., where Tg is the glass transition temperature of the cycloolefin resin, and (Tg+5) to (Tg+30). ) °C. When the stretching temperature is (Tg + 2) ° C. or higher, the solvent is easily volatilized appropriately, so it is easy to adjust the stretching tension to an appropriate range. It is difficult to lose sex. As for the stretching temperature, it is preferable to measure (a) the ambient temperature such as the temperature inside the stretching machine, as described above.

The amount of residual solvent in the filmy material at the start of stretching is preferably about the same as the amount of residual solvent in the filmy material at the time of peeling, for example, preferably 20 to 30% by mass, preferably 25 to 30% by mass. % range is more preferred.

Stretching in the TD direction (width direction) of the film can be performed, for example, by fixing both ends of the film with clips or pins and widening the distance between the clips or pins in the direction of travel (tenter method). The film-like material can be stretched in the MD direction, for example, by a method (roll method) in which a plurality of rolls are provided with different peripheral speeds and the difference in peripheral speeds of the rolls is utilized. In particular, a tenter method in which both ends of the casting film are held with clips and stretched is preferable in order to improve the flatness and dimensional stability of the film. By stretching the cast film in both the MD and TD directions, it is preferable to stretch in a direction that obliquely intersects the MD and TD directions (diagonal stretching).

Step 5) (Drying Step) The stretched casting film and coating material are further dried to obtain an optical film having an easy-adhesion layer on the substrate.

The casting film and the coating material can be dried, for example, while the casting film is being transported by a plurality of transport rolls (for example, a plurality of transport rolls arranged in a zigzag pattern when viewed from the side). The drying means is not particularly limited, and hot air, infrared rays, heating rolls or microwaves are used. Hot air drying is preferred because of its simplicity.

Regarding Step 6) (Cutting/Embossing Step) Both ends in the width direction of the obtained optical film are cut. Both ends of the optical film can be cut by a slitter.

Next, embossing (knurling) is applied to both ends of the optical film in the width direction. Embossing can be performed by pressing a heated embossing roller against both ends of the optical film. Fine irregularities are formed on the surface of the embossing roller, and by pressing the embossing roller against both ends of the optical film, irregularities are formed on both ends. Such embossing can minimize winding misalignment and blocking (sticking of films together) in the next winding process.

About the step of 7) (roughened surface forming step) A roughened surface is formed on the cut optical film. The roughened surface can be formed by embossing using a mold, plasma etching, sandblasting, sandpaper treatment, casting film formation under high humidity conditions, or the like, and embossing using a mold is most preferred.
In the method of embossing with a mold, the roll-shaped mold is rotated to run the optical film in the direction of rotation along the outer peripheral surface of the mold with a predetermined pressure and time, and then the optical film is peeled off from the mold. to form a roughened surface.
Here, the single-sided external haze can be adjusted by changing the mold pressure and pressing time, and the single-sided external haze value increases by lengthening the pressing time or increasing the pressure.

About the process of 8) (winding process) Then, the obtained optical film is wound up to obtain a roll body.

That is, a roll body is formed by winding the optical film around the core while transporting it. The method of winding the optical film may be any method using a generally used winder, and a method of controlling tension such as a constant torque method, a constant tension method, a taper tension method, or a program tension control method with constant internal stress. There is

The winding length of the optical film in the roll body is preferably within the range of 1000 to 7200 m. The width of the optical film is preferably in the range of 1000-3000 mm.

[Polarizer]
The polarizing plate of the present invention is a polarizing plate in which at least a polarizing plate protective film, a polarizer layer, an optical film and an adhesive sheet are laminated in this order, and the optical film is the optical film of the present invention.

<Adhesive sheet>
The adhesive sheet has an adhesive layer formed from an adhesive composition.
As the pressure-sensitive adhesive sheet, for example, a double-sided pressure-sensitive adhesive sheet having only a pressure-sensitive adhesive layer, a substrate, and pressure-sensitive adhesive layers formed on both sides of the substrate, at least one pressure-sensitive adhesive layer being formed from the pressure-sensitive adhesive composition. A double-sided pressure-sensitive adhesive sheet that is a pressure-sensitive adhesive layer formed on a substrate, a single-sided pressure-sensitive adhesive sheet that has the above-mentioned pressure-sensitive adhesive layer formed on one side of the substrate, and the pressure-sensitive adhesive layer of these pressure-sensitive adhesive sheets that are not in contact with the substrate A pressure-sensitive adhesive sheet having a separator attached to the surface can be used.

The pressure-sensitive adhesive composition preferably comprises, for example, an acrylic pressure-sensitive adhesive main agent, a cross-linking agent, an antioxidant, and the like.
Examples of the acrylic pressure-sensitive adhesive base include 4-hydroxybutyl acrylate units (4-HBA), butyl acrylate units, and methyl acrylate units.
Examples of the cross-linking agent include tolylene diisocyanate-based compounds and xylylene diisocyanate.
Examples of the antioxidant include hindered phenolic antioxidants such as pentaerythritol-tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate) (manufactured by BASF Japan, IRGANOX1010), Phosphorus antioxidants such as tris(2,4-di-t-butylphenyl)phosphite (IRGAFOS168, manufactured by BASF Japan).

The acrylic pressure-sensitive adhesive main agent in the pressure-sensitive adhesive composition is preferably contained in the range of 10 to 90% by mass, and the cross-linking agent is contained in the range of 0.01 to 5.00% by mass. The content of the antioxidant is preferably within the range of 0.01 to 5.00% by mass.

(moisture content)
The pressure-sensitive adhesive sheet preferably has a low water content in order to suppress the occurrence of high-humidity shock. . Therefore, the moisture content of the pressure-sensitive adhesive sheet is preferably in the range of 3.0 to 10.0%, particularly preferably in the range of 3.5 to 5.5%.

The moisture content of the adhesive sheet is determined by forming an adhesive layer on a polyester film with a thickness of 50 μm, cutting it to 60 mm × 130 mm, and then pasting the adhesive sheet on a polycarbonate having a thickness of 1 mm cut to 70 mm × 150 mm. It is obtained by standing in an environment of 40° C. and 95% RH for 48 hours and measuring the mass increase of the adhesive.

In order to make the water content of the pressure-sensitive adhesive sheet within the range of 3.0 to 10.0%, for example, the content of 4-hydroxybutyl acrylate units (4-HBA) in the pressure-sensitive adhesive composition is The content may be within the range of 4.0 to 25% by mass.

<Polarizer layer>
In the present invention, the term "polarizer layer" refers to an optical layer having a property of transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis when unpolarized light is incident. In other words, it refers to an optical layer that transmits only light with a plane of polarization in a certain direction.
A polarizing film (also referred to as a “polarizer film” and a “polarizer film”) constituting a typical polarizer layer known at present is a polyvinyl alcohol-based polarizing film. The polyvinyl alcohol-based polarizing film includes a polyvinyl alcohol-based film dyed with iodine and a polyvinyl alcohol-based film dyed with a dichroic dye.

The polyvinyl alcohol-based polarizing film may be a film obtained by uniaxially stretching a polyvinyl alcohol-based film and then dyeing it with iodine or a dichroic dye (preferably a film further subjected to durability treatment with a boron compound); A film obtained by dyeing an alcohol-based film with iodine or a dichroic dye and then uniaxially stretching the film (preferably, a film further subjected to a durability treatment with a boron compound) may be used. The absorption axis of the polarizing film (polarizer layer) is generally parallel to the maximum stretching direction.

For example, JP 2003-248123, JP 2003-342322, etc. ethylene unit content 1 to 4 mol%, degree of polymerization 2000 to 4000, degree of saponification 99.0 to 99.99 mol% Ethylene modified polyvinyl alcohol is used. Among them, an ethylene-modified polyvinyl alcohol film having a hot water cutting temperature of 66 to 73° C. is preferably used.

The thickness of the polarizer layer is preferably in the range of 5 to 30 μm, and more preferably in the range of 5 to 20 μm for thinning the polarizing plate.

When the optical film of the present invention is used as a λ/4 film, the angle formed by the in-plane slow axis of the optical film of the present invention and the absorption axis of the polarizer layer is in the range of 20 to 70°. It is preferably in the range of 30 to 60°, more preferably in the range of 40 to 50°. When the optical film of the present invention is used as a retardation film for VA, the in-plane slow axis of the optical film of the present invention and the absorption axis of the polarizer layer can be substantially orthogonal.

Moreover, it is preferable that the polarizer layer and the easy-adhesion layer of the optical film are bonded together via an adhesive or a pressure-sensitive adhesive.
The adhesive may be a water-based adhesive containing polyvinyl alcohol resin or urethane resin as a main component, or a photocurable adhesive containing photocurable resin such as epoxy resin as a main component. The adhesive may contain acrylic polymers, silicone polymers, polyesters, polyurethanes, polyethers, etc. as base polymers. Among them, water-based adhesives are preferable because they have good affinity with the optical film of the present invention and are less likely to be distorted due to water absorption.
The bonding of the polarizer layer and the optical film of the present invention can usually be carried out by roll-to-roll.

<Protective film for polarizing plate>
A polarizing plate protective film is arranged on the surface of the polarizer layer opposite to the optical film.
Examples of polarizing plate protective films include commercially available cellulose acylate films (e.g., Konica Minolta Tack KC6UA, KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR-1 , KC8UY-HA, KC8UX-RHA, KC8UE, KC4UE, KC4HR-1, KC4KR-1, KC4UA, KC6UA (manufactured by Konica Minolta Opto Co., Ltd.) and the like.

The thickness of the polarizing plate protective film is not particularly limited, but is preferably in the range of 10 to 100 μm, more preferably in the range of 10 to 60 μm, and preferably in the range of 20 to 60 μm. Especially preferred.
The polarizing plate protective film and the polarizer layer are preferably bonded together via an adhesive or pressure-sensitive adhesive, and the adhesive or pressure-sensitive adhesive is the adhesive or pressure-sensitive adhesive used for bonding the polarizer layer and the optical film. A similar adhesive can be used.

[Liquid crystal display device]
The liquid crystal display device according to the present invention is preferably a liquid crystal display device in which the polarizing plate is attached to at least one surface of a liquid crystal cell, and the adhesive sheet is more preferably adjacent to the liquid crystal cell. .

FIG. 2 is a schematic diagram showing an example of the basic configuration of a liquid crystal display device. As shown in FIG. 2, the liquid crystal display device 20 of the present invention includes a liquid crystal cell 30, a first polarizing plate 40 and a second polarizing plate 50 sandwiching it, and a backlight 60. FIG.

The display mode of the liquid crystal cell 30 may be any display mode such as TN (Twisted Nematic), VA (Visual Alignment), or IPS (InPlane Switching). For liquid crystal cells for mobile devices, for example, IPS mode is preferable. For liquid crystal cells for medium-sized and large-sized applications, for example, the VA mode is preferable.

The first polarizing plate 40 is arranged on the surface of the liquid crystal cell 30 on the viewing side, and the first polarizer layer 41 and the surface of the first polarizer layer 41 opposite to the liquid crystal cell 30 are arranged. and a protective film 45 (F2) disposed on the surface of the first polarizer layer 41 facing the liquid crystal cell.

The second polarizing plate 50 is arranged on the backlight side surface of the liquid crystal cell 30 , the second polarizer layer 51 and the protective layer 51 arranged on the liquid crystal cell side surface of the second polarizer layer 51 . It includes a film 53 (F3) and a protective film 55 (F4) disposed on the side of the second polarizer layer 51 opposite to the liquid crystal cell.

The absorption axis of the first polarizer layer 41 and the absorption axis of the second polarizer layer 51 are preferably orthogonal.

The protective film 45 (F2) can be the optical film of the present invention. The optical film (the easy-adhesion layer 47 of the protective film 45 (F2) and the first polarizer layer 41 are laminated via an adhesive or a pressure-sensitive adhesive. The in-plane slow axis of the protective film 45 (F2) and the absorption axis of the first polarizer layer 41. The protective films 43 (F1), 53 (F3) and 55 (F4) can be, for example, the polarizing plate protective films described above. is the substrate.

Although FIG. 2 shows an example in which the protective film 45 (F2) is the optical film of the present invention, it is not limited to this, and 53 (F3) may be the optical film of the present invention. For example, when the protective film 53 (F3) is the optical film of the present invention, the surface of the substrate of the protective film 53 (F3) opposite to the liquid crystal cell 30 (that is, the surface on the polarizer layer 51 side) is easily adhered. A layer (not shown) may be formed.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the following examples, unless otherwise specified, operations were performed at room temperature (25°C). Moreover, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass" respectively.

[Comparative Example 1]
<Optical film 101>
A commercially available e-ZB12 (manufactured by Nippon Zeon Co., Ltd.) (film a in which an easy-adhesion layer is formed on a substrate) was used as the optical film 101 .

[Comparative Example 2]
<Unstretched optical film b1>
A commercially available product "ZEONOR1420R" (manufactured by Nippon Zeon Co., Ltd.) was used as the unstretched optical film b1.

<Preparation of coating material (water-based resin composition) A>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane (“Superflex 210” manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ester-based polyurethane resin containing a carboxy group), and add an epoxy compound ( Product name “Denacol EX-521” manufactured by Nagase ChemteX Corporation) 15 parts by mass, 6 parts by mass of adipic acid dihydrazide, 5 parts by mass of silica particles (average primary particle size 100 nm, standard deviation 20 nm), and water. Then, coating material A
was obtained as a liquid water-based resin composition having a solid content of 8%.

<Application of coating material>
Using a corona treatment device (manufactured by Kasuga Denki Co., Ltd.), the unstretched optical film b1 prepared above (commercially available “ZEONOR1420R” (Nippon Zeon Co., Ltd.)) was subjected to discharge treatment on one surface. The coating material A was applied to the discharge-treated surface of the unstretched optical film b1 using a roll coater so that the dry film thickness was 2.0 μm.

<Production of optical film 102>
Then, using a tenter-type transverse stretching machine, both ends of the unstretched optical film b1 are gripped with clips, and continuously transversely uniaxially stretched at a stretching temperature of 155° C. and a stretching ratio of 2.6 times. A section was cut out and removed. As a result, the step of drying and curing the coating material A and the step of stretching the unstretched optical film b1 are carried out simultaneously, and a coating layer (made of polyurethane resin) is formed on the surface of the stretched optical film b1 (substrate). An optical film 102 laminated with an adhesive layer) was obtained. The optical film 102 had a substrate with a thickness of 39 μm, a width of 1300 mm, and an easily adhesive layer with a thickness of 50 nm.

[Example 1]
<Production of unstretched optical film b2>
Pellets of a resin containing a cycloolefin polymer (glass transition temperature: 137° C.; “ZEONOR1420R” manufactured by Zeon Corporation) were dried at 100° C. for 5 hours. The dried resin pellets were then fed into a single screw extruder. After being melted in the extruder, the resin was passed through a polymer pipe and a polymer filter, extruded into a sheet from a T-die onto a casting drum, and cooled. As a result, an unstretched optical film b2 having a thickness of 100 μm and a width of 500 mm was obtained.

<Preparation of coating material B>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane (polyurethane composed of polycarbonate polyol and aliphatic polyisocyanate; see Table I for details), and an epoxy compound (product Name “Denacol EX-521” manufactured by Nagase ChemteX Corporation) 15 parts by weight, 6 parts by weight of adipic acid dihydrazide, 5 parts by weight of silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water. Thus, a coating material B was obtained as a liquid water-based resin composition having a solid content of 8%.

<Application of coating material>
Using a corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.), discharge treatment was performed on one surface of the unstretched optical film b2 prepared above under the conditions of an output of 500 W, an electrode length of 1.35 m, and a transport speed of 15 m/min. . The coating material B was applied to the discharge-treated surface of the unstretched optical film b2 using a roll coater so that the dry film thickness was 2.0 μm.

<Production of optical film 103>
Thereafter, using a tenter-type transverse stretching machine, both ends of the unstretched optical film b2 are gripped with clips, and continuously transversely uniaxially stretched at a stretching temperature of 155° C. and a stretching ratio of 2.6 times. A section was cut out and removed. As a result, the step of drying and curing the coating material B and the step of stretching the unstretched optical film b2 are carried out simultaneously, and a coating layer (made of polyurethane resin) is formed on the surface of the stretched optical film b2 (substrate). An optical film 103 laminated with an adhesive layer) was obtained. The optical film 103 had a substrate with a thickness of 39 μm, a width of 1300 mm, and an easily adhesive layer with a thickness of 50 nm.

[Example 2]
<Production of optical film 104>
In the production of the optical film 103, the coating material B is applied in the same manner, and then using a tenter-type lateral stretching machine, the film is continuously laterally uniaxially stretched at a stretching temperature of 155°C and a stretching ratio of 3.0 times. The left and right ends were cut off and removed. As a result, the step of drying and curing the coating material B and the step of stretching the unstretched optical film b2 are carried out simultaneously, and a coating layer (made of polyurethane resin) is formed on the surface of the stretched optical film b2 (substrate). An optical film 104 laminated with an adhesive layer) was obtained. The optical film 104 had a substrate with a thickness of 30 μm, a width of 1500 mm, and an easily adhesive layer with a thickness of 50 nm.

[Example 3]
<Preparation of Coating Material C>
100 parts by mass of a water dispersion of polyurethane (polyurethane composed of polyester polyol and aliphatic polyisocyanate; see Table I for details) is taken (the amount of polyurethane in the water dispersion), and an epoxy compound (product Name “Denacol EX-521” manufactured by Nagase ChemteX Corporation) 15 parts by weight, 6 parts by weight of adipic acid dihydrazide, 5 parts by weight of silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water. Thus, a coating material C was obtained as a liquid water-based resin composition having a solid content of 8%.

<Application of coating material>
Using a corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.), discharge treatment was performed on one surface of the unstretched optical film b2 prepared above under the conditions of an output of 500 W, an electrode length of 1.35 m, and a transport speed of 15 m/min. . The coating material C was applied to the discharge-treated surface of the unstretched optical film b2 using a roll coater so that the dry film thickness was 2.0 μm.

<Manufacture of optical film 105>
Thereafter, using a tenter-type transverse stretching machine, both ends of the unstretched optical film b2 are gripped with clips, and continuously transversely uniaxially stretched at a stretching temperature of 155° C. and a stretching ratio of 2.6 times. A section was cut out and removed. As a result, the step of drying and curing the coating material C and the step of stretching the unstretched optical film b2 are carried out simultaneously, and a coating layer (made of polyurethane resin) is formed on the surface of the stretched optical film b2 (substrate). An optical film 105 laminated with an adhesive layer) was obtained. The optical film 105 had a substrate with a thickness of 39 μm, a width of 1300 mm, and an easily adhesive layer with a thickness of 50 nm.

[Example 4]
<Production of coating material D>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous polyurethane dispersion (polyether polyol and aliphatic polyisocyanate-based polyurethane; see Table I for details), and add an epoxy compound ( Product name “Denacol EX-521” manufactured by Nagase ChemteX Corporation) 15 parts by mass, 6 parts by mass of adipic acid dihydrazide, 5 parts by mass of silica particles (average primary particle size 100 nm, standard deviation 20 nm), and water are blended. Thus, a coating material D was obtained as a liquid water-based resin composition having a solid content of 8%.

<Application of coating material>
Using a corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.), discharge treatment was performed on one surface of the unstretched optical film b2 prepared above under the conditions of an output of 500 W, an electrode length of 1.35 m, and a transport speed of 15 m/min. . The coating material D was applied to the discharge-treated surface of the unstretched optical film b2 using a roll coater so that the dry film thickness was 2.0 μm.

<Production of optical film 106>
Thereafter, using a tenter-type transverse stretching machine, both ends of the unstretched optical film b2 are gripped with clips, and continuously transversely uniaxially stretched at a stretching temperature of 155° C. and a stretching ratio of 2.6 times. A section was cut out and removed. As a result, the step of drying and curing the coating material D and the step of stretching the unstretched optical film b2 are carried out simultaneously, and a coating layer (made of polyurethane resin) is formed on the surface of the stretched optical film b2 (substrate). An optical film 106 laminated with an adhesive layer) was obtained. The optical film 106 had a substrate with a thickness of 39 μm, a width of 1300 mm, and an easily adhesive layer with a thickness of 50 nm.

[Example 5]
<Production of coating material E>
100 parts by mass of a water dispersion of polyurethane (polyurethane composed of polyester polyol and alicyclic polyisocyanate; see Table I for details) (the amount of polyurethane in the water dispersion), and an epoxy compound ( Product name “Denacol EX-521” manufactured by Nagase ChemteX Corporation) 15 parts by mass, 6 parts by mass of adipic acid dihydrazide, 5 parts by mass of silica particles (average primary particle size 100 nm, standard deviation 20 nm), and water are blended. Thus, a coating material E was obtained as a liquid water-based resin composition having a solid content of 8%.

<Application of coating material>
Using a corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.), discharge treatment was performed on one surface of the unstretched optical film b2 prepared above under the conditions of an output of 500 W, an electrode length of 1.35 m, and a transport speed of 15 m/min. . The coating material E was applied to the discharge-treated surface of the unstretched optical film b2 using a roll coater so that the dry film thickness was 2.0 μm.

<Manufacture of optical film 107>
Thereafter, using a tenter-type transverse stretching machine, both ends of the unstretched optical film b2 are gripped with clips, and continuously transversely uniaxially stretched at a stretching temperature of 155° C. and a stretching ratio of 2.6 times. A section was cut out and removed. As a result, the step of drying and curing the coating material E and the step of stretching the unstretched optical film b2 are carried out simultaneously, and a coating layer (made of polyurethane resin) is formed on the surface of the stretched optical film b2 (substrate). An optical film 107 laminated with an adhesive layer) was obtained. The optical film 107 had a substrate with a thickness of 39 μm, a width of 1300 mm, and an easily adhesive layer with a thickness of 50 nm.

[Example 6]
<Production of coating material F>
100 parts by mass of an aqueous dispersion of polyurethane (polyurethane composed of a polyester polyol and an aromatic polyisocyanate; see Table I for details), and an epoxy compound (product Name “Denacol EX-521” manufactured by Nagase ChemteX Corporation) 15 parts by weight, 6 parts by weight of adipic acid dihydrazide, 5 parts by weight of silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water. Thus, a coating material F was obtained as a liquid water-based resin composition having a solid content of 8%.

<Application of coating material>
Using a corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.), discharge treatment was performed on one surface of the unstretched optical film b2 prepared above under the conditions of an output of 500 W, an electrode length of 1.35 m, and a transport speed of 15 m/min. . The coating material F was applied to the discharge-treated surface of the unstretched optical film b2 using a roll coater so that the dry film thickness was 2.0 μm.

<Manufacture of optical film 108>
Thereafter, using a tenter-type transverse stretching machine, both ends of the unstretched optical film b2 are gripped with clips, and continuously transversely uniaxially stretched at a stretching temperature of 155° C. and a stretching ratio of 2.6 times. A section was cut out and removed. As a result, the step of drying and curing the coating material F and the step of stretching the unstretched optical film b2 are carried out simultaneously, and a coating layer (made of polyurethane resin) is formed on the surface of the stretched optical film b2 (substrate). An optical film 108 laminated with an adhesive layer) was obtained. The optical film 108 had a substrate with a thickness of 39 μm, a width of 1300 mm, and an easily adhesive layer with a thickness of 50 nm.

[Example 7]
<Preparation of Coating Material G>
Coating material G was prepared in the same manner as in preparation of coating material B, except that the average primary particle size of the silica particles was 200 nm.

<Application of coating material>
The procedure was the same as in Example 1, except that the coating material G was applied to the discharge-treated surface of the unstretched optical film b2.

<Production of optical film 109>
An optical film 109 was obtained in the same manner as in Example 1, except that the coating material G was cured.

[Example 8]
<Production of Coating Material H>
Coating material H was prepared in the same manner as in preparation of coating material B, except that the average primary particle size of the silica particles was 140 nm.

<Application of coating material>
The procedure was the same as in Example 1, except that the coating material H was applied to the discharge-treated surface of the unstretched optical film b2.

<Manufacture of optical film 110>
An optical film 110 was obtained in the same manner as in Example 1, except that the coating material H was cured.

[Example 9]
<Preparation of coating material I>
Coating material I was prepared in the same manner as in preparation of coating material B, except that the average primary particle size of the silica particles was 60 nm.

<Application of coating material>
The procedure was the same as in Example 1, except that the coating material I was applied to the discharge-treated surface of the unstretched optical film b2.

<Manufacture of optical film 111>
An optical film 111 was obtained in the same manner as in Example 1, except that the coating material I was cured.

[Example 10]
<Production of Coating Material J>
Coating material J was prepared in the same manner as in preparation of coating material B, except that the standard deviation of the primary particle size of the silica particles was set to 30 nm.

<Application of coating material>
The procedure was the same as in Example 1, except that the coating material J was applied to the discharge-treated surface of the unstretched optical film b2.

<Manufacture of optical film 112>
An optical film 112 was obtained in the same manner as in Example 1, except that the coating material J was cured.

[Example 11]
<Production of Coating Material K>
Coating material K was prepared in the same manner as in preparation of coating material B, except that the standard deviation of the primary particle size of the silica particles was set to 10 nm.

<Application of coating material>
The procedure was the same as in Example 1, except that the coating material K was applied to the discharge-treated surface of the unstretched optical film b2.

<Manufacture of optical film 113>
An optical film 113 was obtained in the same manner as in Example 1, except that the coating material K was cured.

[Example 12]
<Production of coating material L>
Coating material L was prepared in the same manner as in preparation of coating material B, except that the standard deviation of the primary particle size of the silica particles was set to 5 nm.

<Application of coating material>
The procedure was the same as in Example 1, except that the coating material L was applied to the discharge-treated surface of the unstretched optical film b2.

<Manufacture of optical film 114>
An optical film 114 was obtained in the same manner as in Example 1 except that the coating material L was cured.

[Comparative Example 3]
<Production of Coating Material M>
Coating material M was prepared in the same manner as in preparation of coating material C, except that the standard deviation of the primary particle size of the silica particles was set to 5 nm.

<Application of coating material>
The procedure was the same as in Example 1, except that the coating material M was applied to the discharge-treated surface of the unstretched optical film b2.

<Production of optical film 115>
An optical film 115 was obtained in the same manner as in Example 1, except that the coating material M was cured.

[Comparative Example 4]
<Production of unstretched optical film b3>
Pellets of a resin containing a cycloolefin polymer (glass transition temperature: 135° C.; “ZEONOR1430” manufactured by Nippon Zeon Co., Ltd.) were dried at 70° C. for 2 hours using a hot air dryer through which air was passed. After that, using a T-die type film melt extruder having a resin melt kneader equipped with a screw with a diameter of 65 mm, the molten resin temperature is 270 ° C., the width of the T die is 500 mm, the thickness is 100 μm, and the length is 1000 m. to obtain an unstretched optical film b3.

<Production of coating material N1>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane (“Superflex 210” manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ester-based polyurethane resin containing a carboxy group), and add an epoxy compound ( Product name “Denacol EX-521” manufactured by Nagase ChemteX Corporation) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica particles (average primary particle size 100 nm, standard deviation 20 nm), and water. 5% solids
obtained as a liquid coating material N1.

<Production of multilayer film>
Using a corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.), under the conditions of an output of 300 W, an electrode length of 240 mm, a work electrode distance of 3.0 mm, and a conveying speed of 4 m/min, one surface of the unstretched optical film b3 prepared above. Discharge treatment was performed. The surface of the unstretched optical film b3 on the discharge-treated side was coated with the coating material N1 using a roll coater so that the dry film thickness was 0.5 μm.

<Manufacture of optical film 116>
Thereafter, using a tenter-type transverse stretching machine, both ends of the unstretched optical film b3 are gripped with clips, and continuously transversely uniaxially stretched at a stretching temperature of 140° C. for 40 seconds at a stretching ratio of 2.0. Furthermore, the left and right ends were cut and removed. As a result, the step of drying the coating material N1 and the step of stretching the film are performed simultaneously, forming an easy-adhesion layer on the surface of the base film, and obtaining the optical film 116 whose orientation axis is aligned in the width direction. rice field. The optical film 116 had a substrate with a thickness of 50 μm, a width of 1000 mm, and an easily adhesive layer with a thickness of 50 nm.

[Comparative Example 5]
<Production of coating material N2>
100 parts by mass of a water dispersion of polyurethane ("Superflex 210" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ester-based polyurethane resin containing a carboxyl group) (the amount of polyurethane in the water dispersion) is taken, and a carbodiimide compound is added thereto. 20 parts by mass of Carbodilite V-02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water are blended. , obtained as a liquid coating material N2 having a solid content of 5%.

<Manufacture of optical film 117>
An optical film 117 was obtained in the same manner as in Comparative Example 4, except that the coating material N2 was used instead of the coating material N1.

[Comparative Example 6]
<Production of coating material N3>
100 parts by mass of a water dispersion of polyurethane ("Superflex 210" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ester-based polyurethane resin containing a carboxyl group) (the amount of polyurethane in the water dispersion) is taken, and a carbodiimide compound is added thereto. A certain Carbodilite SV-02 (manufactured by Nisshinbo Chemical Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water are blended to form a solid. It was obtained as a 5% liquid coating material N3.

<Manufacture of optical film 118>
An optical film 118 was obtained in the same manner as in Comparative Example 4, except that the coating material N3 was used instead of the coating material N1.

[Comparative Example 7]
<Production of coating material N4>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane (“Superflex 210” manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a carboxyl group-containing ester polyurethane resin) is taken, and an oxazoline compound is added thereto. 20 parts of certain Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd.), 5 parts of dihydrazide sebacate, 8 parts of fine silica particles (average primary particle size: 100 nm, standard deviation: 20 nm), and water were blended to give a solid content of 5%. obtained as a liquid coating material N4.

<Production of optical film 119>
An optical film 119 was obtained in the same manner as in Comparative Example 4, except that the coating material N4 was used instead of the coating material N1.

[Comparative Example 8]
<Production of coating material O1>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 130" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ether-based polyurethane resin containing a carboxy group), and add an epoxy compound thereto. 20 parts of Denacol EX-521 (manufactured by Nagase ChemteX Corporation), 5 parts by weight of dihydrazide sebacate, 8 parts by weight of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water are blended to form a solid. It was obtained as a 5% liquid coating material O1.

<Manufacture of optical film 120>
An optical film 120 was obtained in the same manner as in Comparative Example 4, except that the coating material O1 was used instead of the coating material N1.

[Comparative Example 9]
<Production of coating material O2>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 130", a carboxy group-containing ether-based polyurethane resin manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and add a carbodiimide compound thereto. 20 parts by mass of Carbodilite V-02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water are blended. , obtained as a liquid coating material O2 having a solid content of 5%.

<Manufacture of optical film 121>
An optical film 121 was obtained in the same manner as in Comparative Example 4, except that the coating material O2 was used instead of the coating material N1.

[Comparative Example 10]
<Production of coating material O3>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 130", a carboxy group-containing ether-based polyurethane resin manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and add a carbodiimide compound thereto. A certain Carbodilite SV-02 (manufactured by Nisshinbo Chemical Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water are blended to form a solid. It was obtained as a 5% liquid coating material O3.

<Manufacture of optical film 122>
An optical film 122 was obtained in the same manner as in Comparative Example 4, except that the coating material O3 was used instead of the coating material N1.

[Comparative Example 11]
<Production of coating material O4>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 130" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ether-based polyurethane resin containing a carboxy group) is taken, and an oxazoline compound is added thereto. 20 parts by mass of Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle size 100 nm, standard deviation 20 nm), and water are mixed to form a solid. It was obtained as a 5% liquid coating material O4.

<Manufacture of optical film 123>
An optical film 123 was obtained in the same manner as in Comparative Example 4, except that the coating material O4 was used instead of the coating material N1.

[Comparative Example 12]
<Production of coating material P1>
100 parts by mass of a polyurethane water dispersion ("Superflex 150HS" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a carboxy group-containing ester/ether polyurethane resin) is taken (the amount of polyurethane in the water dispersion), and epoxy is added here. 20 parts by mass of the compound Denacol EX-521 (manufactured by Nagase ChemteX Corporation), 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water were blended. to obtain a liquid coating material P1 having a solid content of 5%.

<Manufacture of optical film 124>
An optical film 124 was obtained in the same manner as in Comparative Example 4, except that the coating material P1 was used instead of the coating material N1.

[Comparative Example 13]
<Production of Coating Material P2>
100 parts by mass of a water dispersion of polyurethane (“Superflex 150HS” manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a carboxy group-containing ester/ether polyurethane resin) (the amount of polyurethane in the water dispersion) is taken, and carbodiimide is added thereto. Compound Carbodilite V-02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water. Then, a liquid coating material P2 having a solid content of 5% was obtained.

<Manufacture of optical film 125>
An optical film 125 was obtained in the same manner as in Comparative Example 4, except that the coating material P2 was used instead of the coating material N1.

[Comparative Example 14]
<Production of coating material P3>
100 parts by mass of a water dispersion of polyurethane (“Superflex 150HS” manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a carboxy group-containing ester/ether polyurethane resin) (the amount of polyurethane in the water dispersion) is taken, and carbodiimide is added thereto. Compound Carbodilite SV-02 (manufactured by Nisshinbo Chemical Co., Ltd.) 20 parts by mass, sebacate dihydrazide 5 parts by mass, silica fine particles (average primary particle diameter 100 nm, standard deviation 20 nm) 8 parts by mass, and water are blended. , obtained as a liquid coating material P3 having a solid content of 5%.

<Production of optical film 126>
An optical film 126 was obtained in the same manner as in Comparative Example 4, except that the coating material P3 was used instead of the coating material N1.

[Comparative Example 15]
<Production of coating material P4>
100 parts by mass of a water dispersion of polyurethane (“Superflex 150HS” manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a carboxy group-containing ester/ether polyurethane resin) (the amount of polyurethane in the water dispersion) was taken, and oxazoline was added thereto. 20 parts by mass of the compound Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water are blended. , obtained as a liquid coating material P4 having a solid content of 5%.

<Manufacture of optical film 127>
An optical film 127 was obtained in the same manner as in Comparative Example 4, except that the coating material P4 was used instead of the coating material N1.

[Comparative Example 16]
<Production of Coating Material Q1>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 870" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ether-based polyurethane resin containing a carboxy group), and add an epoxy compound thereto. 20 parts by mass of Denacol EX-521 (manufactured by Nagase ChemteX Corporation), 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water are blended. It was obtained as a liquid coating material Q1 having a solid content of 5%.

<Manufacture of optical film 128>
An optical film 128 was obtained in the same manner as in Comparative Example 4, except that the coating material Q1 was used instead of the coating material N1.

[Comparative Example 17]
<Production of Coating Material Q2>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 870" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a carboxy group-containing ether-based polyurethane resin) is taken, and a carbodiimide compound is added thereto. 20 parts by mass of Carbodilite V-02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water are blended. , obtained as a liquid coating material Q2 having a solid content of 5%.

<Production of optical film 129>
An optical film 129 was obtained in the same manner as in Comparative Example 4, except that the coating material Q2 was used instead of the coating material N1.

[Comparative Example 18]
<Production of coating material Q3>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 870" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a carboxy group-containing ether-based polyurethane resin) is taken, and a carbodiimide compound is added thereto. A certain Carbodilite SV-02 (manufactured by Nisshinbo Chemical Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water are blended to form a solid. It was obtained as a 5% liquid coating material Q3.

<Manufacture of optical film 130>
An optical film 130 was obtained in the same manner as in Comparative Example 4, except that the coating material Q3 was used instead of the coating material N1.

[Comparative Example 19]
<Production of coating material Q4>
Take 100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Superflex 870" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., an ether-based polyurethane resin containing a carboxy group), and add an oxazoline compound. 20 parts by mass of Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle size 100 nm, standard deviation 20 nm), and water are mixed to form a solid. It was obtained as a 5% liquid coating material Q4.

<Manufacture of optical film 131>
An optical film 131 was obtained in the same manner as in Comparative Example 4, except that the coating material Q4 was used instead of the coating material N1.

[Comparative Example 20]
<Production of coating material R1>
100 parts by mass of an aqueous dispersion of polyurethane ("Hydran WLS201" manufactured by DIC, a carboxyl group-containing ether-based polyurethane resin) (the amount of polyurethane in the aqueous dispersion) was taken, and Denacol EX-, an epoxy compound, was added thereto. 521 (manufactured by Nagase ChemteX Corporation), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water to give a solid content of 5%. obtained as a liquid coating material R1.

<Manufacture of optical film 132>
An optical film 132 was obtained in the same manner as in Comparative Example 4, except that the coating material R1 was used instead of the coating material N1.

[Comparative Example 21]
<Production of coating material R2>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Hydran WLS201" manufactured by DIC, a carboxy group-containing ether-based polyurethane resin) was taken, and carbodiimide V-, a carbodiimide compound, was added thereto. 02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of fine silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water were mixed to obtain a solid content of 5. % liquid coating material R2.

<Production of optical film 133>
An optical film 133 was obtained in the same manner as in Comparative Example 4, except that the coating material R2 was used instead of the coating material N1.

[Comparative Example 22]
<Production of coating material R3>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Hydran WLS201" manufactured by DIC Corporation, a carboxyl group-containing ether-based polyurethane resin) was taken, and carbodiimide compound carbodilite SV- was added thereto. 02 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of fine silica particles (average primary particle size: 100 nm, standard deviation: 20 nm), and water to obtain a solid content of 5%. It was obtained as a liquid coating material R3.

<Production of optical film 134>
An optical film 134 was obtained in the same manner as in Comparative Example 4, except that the coating material R3 was used instead of the coating material N1.

[Comparative Example 23]
<Production of coating material R4>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Hydran WLS201" manufactured by DIC, a carboxyl group-containing ether-based polyurethane resin) was taken, and Epocross WS-, which is an oxazoline compound, was added thereto. 700 (manufactured by Nippon Shokubai Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle size 100 nm, standard deviation 20 nm), and water to obtain a solid content of 5%. It was obtained as a liquid coating material R4.

<Manufacture of optical film 135>
An optical film 135 was obtained in the same manner as in Comparative Example 4, except that the coating material R4 was used instead of the coating material N1.

[Comparative Example 24]
<Production of coating material S1>
100 parts by mass of an aqueous dispersion of polyurethane ("Hydran WLS202", carboxy group-containing ether-based polyurethane resin manufactured by DIC Corporation) (the amount of polyurethane in the aqueous dispersion) was taken, and Denacol EX-, an epoxy compound, was added thereto. 521 (manufactured by Nagase ChemteX Corporation), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water to give a solid content of 5%. obtained as a liquid coating material S1.

<Manufacture of optical film 136>
An optical film 136 was obtained in the same manner as in Comparative Example 4, except that the coating material S1 was used instead of the coating material N1.

[Comparative Example 25]
<Production of Coating Material S2>
100 parts by mass of an aqueous dispersion of polyurethane ("Hydran WLS202", carboxy group-containing ether-based polyurethane resin manufactured by DIC Corporation) (the amount of polyurethane in the aqueous dispersion) was taken, and Carbodilite V-, which is a carbodiimide compound, was added thereto. 02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of fine silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water were mixed to obtain a solid content of 5. % liquid coating material S2.

<Manufacture of optical film 137>
An optical film 137 was obtained in the same manner as in Comparative Example 4, except that the coating material S2 was used instead of the coating material N1.

[Comparative Example 26]
<Production of coating material S3>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Hydran WLS202" manufactured by DIC, a carboxyl group-containing ether-based polyurethane resin) was taken, and carbodiimide compound Carbodilite SV- was added thereto. 02 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of fine silica particles (average primary particle size: 100 nm, standard deviation: 20 nm), and water to obtain a solid content of 5%. It was obtained as a liquid coating material S3.

<Production of optical film 138>
An optical film 138 was obtained in the same manner as in Comparative Example 4, except that the coating material S3 was used instead of the coating material N1.

[Comparative Example 27]
<Production of coating material S4>
100 parts by mass (the amount of polyurethane in the aqueous dispersion) of an aqueous dispersion of polyurethane ("Hydran WLS202" manufactured by DIC, a carboxy group-containing ether-based polyurethane resin) was taken, and Epocross WS-, which is an oxazoline compound, was added thereto. 700 (manufactured by Nippon Shokubai Co., Ltd.) 20 parts by mass, 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle size 100 nm, standard deviation 20 nm), and water to obtain a solid content of 5%. It was obtained as a liquid coating material S4.

<Production of optical film 139>
An optical film 139 was obtained in the same manner as in Comparative Example 4, except that the coating material S4 was used instead of the coating material N1.

[Comparative Example 28]
<Production of coating material T1>
100 parts by mass of a water dispersion of polyurethane (“Pesresin A-684G” manufactured by Takamatsu Yushi Co., Ltd., a carboxyl group-containing polyester resin acrylic resin composite) (the amount of polyester in the water dispersion) is taken, and an epoxy compound is added thereto. 20 parts by mass of Denacol EX-521 (manufactured by Nagase ChemteX Corporation), 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water. , obtained as a liquid coating material T1 having a solid content of 5%.

<Production of optical film 140>
An optical film 140 was obtained in the same manner as in Comparative Example 4, except that the coating material T1 was used instead of the coating material N1.

[Comparative Example 29]
<Production of coating material T2>
100 parts by mass of a polyurethane aqueous dispersion (“Pesresin A-684G” manufactured by Takamatsu Yushi Co., Ltd., a carboxy group-containing polyester resin acrylic resin composite) (the amount of polyester in the aqueous dispersion) is taken, and a carbodiimide compound is added thereto. 20 parts by mass of Carbodilite V-02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of sebacate dihydrazide, 8 parts by mass of fine silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water. to obtain a liquid coating material T2 having a solid content of 5%.

<Production of optical film 141>
An optical film 141 was obtained in the same manner as in Comparative Example 4, except that the coating material T2 was used instead of the coating material N1.

[Comparative Example 30]
<Production of coating material T3>
100 parts by mass of a polyurethane aqueous dispersion (“Pesresin A-684G” manufactured by Takamatsu Yushi Co., Ltd., a carboxy group-containing polyester resin acrylic resin composite) (the amount of polyester in the aqueous dispersion) is taken, and a carbodiimide compound is added thereto. 20 parts by mass of Carbodilite SV-02 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of fine silica particles (average primary particle size: 100 nm, standard deviation: 20 nm), and water, It was obtained as a liquid coating material T3 having a solid content of 5%.

<Production of optical film 142>
An optical film 142 was obtained in the same manner as in Comparative Example 4, except that the coating material T3 was used instead of the coating material N1.

[Comparative Example 31]
<Production of coating material T4>
100 parts by mass of a water dispersion of polyurethane ("Pesresin A-684G" manufactured by Takamatsu Yushi Co., Ltd., a carboxyl group-containing polyester resin acrylic resin composite) (the amount of polyester in the water dispersion) is taken, and an oxazoline compound is added thereto. 20 parts by mass of Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water, It was obtained as a liquid coating material T4 having a solid content of 5%.

<Production of optical film 143>
An optical film 143 was obtained in the same manner as in Comparative Example 4, except that the coating material T4 was used instead of the coating material N1.

[Comparative Example 32]
<Production of coating material U1>
100 parts by mass of a polyurethane water dispersion (“Pesresin A-695GE” manufactured by Takamatsu Yushi Co., Ltd., a carboxyl group-containing polyester resin acrylic resin composite) (the amount of polyester in the water dispersion) is taken, and an epoxy compound is added thereto. 20 parts by mass of Denacol EX-521 (manufactured by Nagase ChemteX Corporation), 5 parts by mass of dihydrazide sebacic acid, 8 parts by mass of fine silica particles (average primary particle diameter: 100 nm, standard deviation: 20 nm), and water. , obtained as a liquid coating material U1 having a solid content of 5%.

<Production of optical film 144>
An optical film 144 was obtained in the same manner as in Comparative Example 4, except that the coating material U1 was used instead of the coating material N1.

[Comparative Example 33]
<Production of coating material U2>
100 parts by mass of a water dispersion of polyurethane ("Pesresin A-695GE" manufactured by Takamatsu Yushi Co., Ltd., a carboxy group-containing polyester resin acrylic resin composite) (the amount of polyester in the water dispersion) is taken, and a carbodiimide compound is added thereto. 20 parts by mass of Carbodilite V-02-L2 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of sebacate dihydrazide, 8 parts by mass of fine silica particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water. to obtain a liquid coating material U2 having a solid content of 5%.

<Production of optical film 145>
An optical film 145 was obtained in the same manner as in Comparative Example 4, except that the coating material U2 was used instead of the coating material N1.

[Comparative Example 34]
<Production of coating material U3>
100 parts by mass of a water dispersion of polyurethane ("Pesresin A-695GE" manufactured by Takamatsu Yushi Co., Ltd., a carboxy group-containing polyester resin acrylic resin composite) (the amount of polyester in the water dispersion) is taken, and a carbodiimide compound is added thereto. 20 parts by mass of Carbodilite SV-02 (manufactured by Nisshinbo Chemical Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of fine silica particles (average primary particle size: 100 nm, standard deviation: 20 nm), and water, It was obtained as a liquid coating material U3 with a solid content of 5%.

<Manufacture of optical film 146>
An optical film 146 was obtained in the same manner as in Comparative Example 4, except that the coating material U3 was used instead of the coating material N1.

[Comparative Example 35]
<Production of coating material U4>
100 parts by mass of a water dispersion of polyurethane (“Pesresin A-695GE” manufactured by Takamatsu Yushi Co., Ltd., a carboxy group-containing polyester resin acrylic resin composite) (the amount of polyester in the water dispersion) is taken, and an oxazoline compound is added thereto. 20 parts by mass of Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd.), 5 parts by mass of dihydrazide sebacate, 8 parts by mass of silica fine particles (average primary particle diameter 100 nm, standard deviation 20 nm), and water, It was obtained as a liquid coating material U4 having a solid content of 5%.

<Manufacture of optical film 147>
An optical film 147 was obtained in the same manner as in Comparative Example 4, except that the coating material U4 was used instead of the coating material N1.

For each optical film obtained, the nanoindentation hardness of the easily adhesive layer was measured as follows.
Measurement was performed using a Triboscope (manufactured by Bruker) as a measuring device. For the measurement, an indenter having a tip edge angle of 90° and a tip curvature radius of 35 to 50 nm was used.
Then, the obtained optical film was cut into a size of 2 cm×2 cm to prepare a measurement sample. Then, the sample to be measured was attached to a metal plate with the substrate side down using an adhesive, and the metal plate with the sample attached was attached to the measuring device, a load was applied, and an operation was performed to return it to 0. . A value P/A obtained by dividing the maximum load P at this time by the area A of the indenter contact portion was calculated as the nanoindentation hardness. The maximum load was set to 20 μN.
Ten points were randomly measured for each sample, and the average value was taken as the nanoindentation hardness.

In Tables I to VI, "COP" means cycloolefin resin.
"Hexamethylene diisocyanate" is hexamethylene-1,6-diisocyanate.

[Preparation of polarizing plate]
A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (at a temperature of 110° C. and a stretching ratio of 5 times), immersed in an aqueous solution consisting of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, then 6 g of potassium iodide, It was immersed in an aqueous solution of 7.5 g of boric acid and 100 g of water at 68°C. The immersed film was washed with water and dried to obtain a polarizer layer.
Subsequently, the easily adhesive layer side of the optical film 101 was attached to one surface of the polarizer layer using an adhesive. At that time, they were laminated so that the transmission axis of the polarizer layer and the slow axis of the optical film 101 were oriented at 45°. A Konica Minolta Tack film KC4UAH (manufactured by Konica Minolta, Inc.) saponified with an alkali was adhered to the other surface of the polarizer layer using an adhesive in the same manner to produce a polarizing plate 201 . The polarizing plates 202 to 247 were similarly produced using the optical films 102 to 147, respectively.

[Preparation of adhesive composition (A)]
To 100 parts by mass of an acrylic pressure-sensitive adhesive main agent having 4.5% by mass of 4-hydroxybutyl acrylate units (4-HBA), 60% by mass of butyl acrylate units and 35.5% by mass of methyl acrylate units, as a cross-linking agent 0.3 parts by mass of tolylene diisocyanate compound (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), pentaerythritol-tetrakis (3-(3,5-di-t-butyl-4- 0.7 parts by mass of hydroxyphenyl) propionate) (IRGANOX1010, manufactured by BASF Japan), and tris (2,4-di-t-butylphenyl) phosphite (IRGAFOS168, manufactured by BASF Japan) as a phosphorus antioxidant. was blended with 0.5 parts by mass to obtain a pressure-sensitive adhesive composition (A).

[Production of adhesive sheet]
The pressure-sensitive adhesive composition (A) prepared above is applied to a release-treated PET film so that the thickness after drying is 25 μm, and dried at 90° C. for 3 minutes to form a pressure-sensitive adhesive layer. was made.

[Fabrication of liquid crystal display device]
In the polarizing plate produced above, the pressure-sensitive adhesive sheet (pressure-sensitive adhesive layer) was provided on the surface of the optical film opposite to the easy-adhesion layer.
Next, as a liquid crystal display device, a Sharp liquid crystal television "AQ-32AD5" was prepared. The polarizing plate on the viewing side was peeled off from this device, and the polarizing plates provided with the adhesive sheet as the polarizing plate were attached so that the adhesive sheet was adjacent to the liquid crystal cell, thereby obtaining liquid crystal display devices 301 to 347.

[evaluation]
<Adhesion under high temperature and high humidity environment>
The polarizing plate obtained above was cut into a width of 25 mm to prepare a test piece. The peel-treated PET film was peeled off from the test piece, and the exposed pressure-sensitive adhesive layer was shifted to a glass plate by 1 cm. After lamination, it was kept in an autoclave adjusted to 50° C./5 atm for 20 minutes and pressure-bonded. After pressure-bonding, the polarizing plate was left in an environment of 60° C. and 95% RH for 1 hour, then pulled against the glass at an angle of 180° C. at a speed of 300 mm/min, and the adhesive strength was measured with a Tensilon. Adhesion strength was evaluated based on the following criteria.
(standard)
⊚: The optical film or adhesive layer was broken and could not be peeled off, and the adhesiveness was good even in an environment of 23°C and 50% RH.
◯: The optical film or adhesive layer was broken and could not be peeled off, and the adhesiveness was good.
◯△: Some peeling occurred between the optical film and the pressure-sensitive adhesive layer, but the adhesion was good.
Δ: Some peeling occurred between the optical film and the pressure-sensitive adhesive layer, but within the range of no problem.
x: The optical film and the pressure-sensitive adhesive layer are completely peeled off, and the adhesion is poor.

<Light leakage (white unevenness) in a high temperature and high humidity environment>
The liquid crystal display device obtained above was displayed in black in a dark room, and the uniformity of the color (black) of the screen was sensory evaluated according to the following criteria.
(standard)
A: White unevenness (light leakage) is not observed at all.
◯: Slight white unevenness, but acceptable for practical use.
◯△: Partial white unevenness is observed, which is worrisome.
Δ: Unpleasant white unevenness is observed ×: White unevenness is clearly observed.

As shown in the above results, when the optical film of the present invention is used, it is recognized that the adhesiveness in a high-temperature and high-humidity environment is better than that of the optical film of the comparative example, and that light leakage can be prevented.

INDUSTRIAL APPLICABILITY The present invention can be used for optical films, polarizing plates, and liquid crystal display devices that can improve adhesion to a polarizer layer and suppress light leakage in a high-temperature, high-humidity environment.

20 liquid crystal display device 30 liquid crystal cell 40 first polarizing plate 41 first polarizer layer 43 protective film (F1)
45 protective film (F2)
46 base material 47 easy adhesion layer 50 second polarizing plate 51 second polarizer layer 53 protective film (F3)
55 protective film (F4)
60 backlight 100 optical film 101 base material 102 easy adhesion layer 200 polarizing plate 300 polarizing plate protective film 400 polarizer layer 500 adhesive sheet

Claims

An optical film having an easy-adhesion layer on at least one surface of a substrate,
The base material contains a cycloolefin resin,
The thickness of the base material is 49 μm or less,
The easy-adhesion layer contains a polyurethane-based resin,
An optical film, wherein the nanoindentation hardness of the easy-adhesion layer on the substrate is less than 0.52 GPa under environmental conditions of 23°C and 50% RH.
The optical film according to claim 1, wherein the polyurethane resin comprises either one of a polyester polyol component and a polyether polyol component.
The easy-adhesion layer contains silica fine particles,
The average primary particle size of the silica fine particles is in the range of 50 to 150 nm, and
3. The optical film according to claim 1, wherein the standard deviation of the average primary particle size is in the range of 5 to 30 nm.
A polarizing plate comprising the optical film according to any one of claims 1 to 3.
A liquid crystal display device comprising the polarizing plate according to claim 4.