JP2017111211A - Optical film, polarizing plate, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film that is excellent in durability and adhesion, a polarizing plate, and an image display device.SOLUTION: There is provided an optical film that includes a cured layer of a curable composition and a surface layer in this order on a base material film, where the curable composition contains at least a compound including an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond, and the surface layer contains at least a polyurethane resin.SELECTED DRAWING: None

Description

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

In recent years, an image display device represented by an electroluminescence display (ELD), a liquid crystal display device (LCD), or the like is required to have a thinner image display device and an improved image quality.
In order to achieve such a reduction in thickness, it is necessary to reduce the thickness of the member itself constituting the image display device. In recent years, the use of image display devices has been diversified, including outdoor use, and there are increasing opportunities for use in harsh environments as compared to the conventional case.
On the other hand, with respect to image quality, it is generally known that the image quality may deteriorate due to the influence of moisture that has passed through the member and entered the image display apparatus. Since the image quality is more likely to be deteriorated in the environment where the image display device is used in recent years, it is required to improve the durability of the image display device.

  By the way, as an optical film that is a member of an image display device, a cellulose resin is preferably used from the viewpoint of versatility and workability. Modification of the optical film itself is also required because of the necessity for increasing the durability described above. Examples of such an optical film include Patent Documents 1 to 4.

JP-A-9-197128 JP 2012-172062 A JP2015-11059A WO2014 / 119487

From the viewpoint of enhancing the durability of the image display device as described above, the present inventors have studied Patent Documents 1 to 4, and it is clear that there is a problem in durability when used for a long time under high temperature and high humidity conditions. It became.
For example, in the method described in Patent Document 2, the performance of suppressing moisture permeation, that is, the low-moisture permeability is insufficient, so that the polarizing plate performance deteriorates when used for a long time under high-temperature and high-humidity conditions, and the image quality deteriorates. Was found to occur. On the other hand, in the case of using a polarizing plate protective film including the transparent substrate layer described in Patent Documents 1 and 4 and a moisture-proof layer in order to achieve low moisture permeability, It was found that the moisture-proof layer peeled off. Moreover, when the liquid crystal display device incorporating the polarizing plate protective film containing the vinyl chloride resin described in Patent Document 3 is discarded as it is, there is a concern about the influence on the environment. Accordingly, an object of the present invention is to provide an optical film, a polarizing plate, and an image display device that are excellent in polarizing plate durability and adhesion.

  The optical film of the present invention is an optical film having a cured layer of a curable composition and a surface layer in this order on a base film, and the curable composition has at least an aliphatic cyclic hydrocarbon group and an ethylenic group. It contains a compound having a saturated double bond, and the surface layer contains at least a polyester urethane resin.

  In one embodiment, the aliphatic cyclic hydrocarbon group is a group represented by the following general formula (I).

  In general formula (I), L and L ′ each independently represent a divalent or higher valent linking group, and n represents an integer of 1 to 3.

  In one aspect, the substrate film is a cellulose acylate film.

  The further aspect of this invention is related with the polarizing plate containing a polarizer and at least 1 sheet of optical film.

  In one aspect, it is a polarizing plate in which the surface layer of the optical film is disposed on the polarizer side.

  In one embodiment, the surface layer is in contact with the polarizer through an adhesive layer including an epoxy-based material.

The further aspect of this invention is related with the image display apparatus which has a polarizing plate.

  According to the present invention, it is possible to provide an optical film, a polarizing plate, and an image display device excellent in polarizing plate durability and adhesion.

It is a figure which shows 1 aspect of the laminated constitution of the optical film of this invention. It is a figure which shows 1 aspect of the laminated constitution of the polarizing plate of this invention.

  Hereinafter, the optical film, polarizing plate, and image display device of the present invention will be described in detail. In the present invention, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value. In the present invention, “(meth) acrylate” represents “acrylate” and “methacrylate”.

<< 1. Optical film >>
An optical film according to one embodiment of the present invention is an optical film having a cured layer and a surface layer of a curable composition on a substrate film, and the curable composition has at least an aliphatic cyclic hydrocarbon group and an ethylenic group. The optical film contains a compound having an unsaturated double bond, and the surface layer contains at least a polyester urethane resin.

  In the optical film that is thinner than the conventional optical film, moisture easily enters from the outside to the inside of the liquid crystal display device, and particularly under the severer usage conditions such as high temperature and high humidity conditions, It is thought that moisture penetration is further promoted. In the polarizer containing the polyvinyl alcohol resin dyed with iodine widely used, the water soaked in the polarizer in this way, the hydrolysis reaction of boric acid crosslinking over time, the polyiodide ion and the above It is thought that decomposition of the complex proceeds. Further, it is presumed that the diffusion of iodines to the outside of the polarizer causes the amount of iodines contained in the polarizer to decrease, resulting in a decrease in polarization performance and degradation of image quality.

However, in the study by the present inventors, the polymer described in Patent Document 1 is used for the purpose of suppressing the intrusion of the moisture into the layer containing cellulose acylate from the viewpoint of easy bonding with a polarizer. When the layers were laminated, it was found that peeling between the layer containing cellulose acylate and the polymer layer occurred.
Here, the present inventors provide an optical film having a cured layer of a curable composition containing a compound having at least an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond, and a surface layer containing at least a polyester urethane resin. In addition to the adhesion of each layer constituting the optical film, it has been found that the adhesion between the optical film and the polarizer can be enhanced.
Furthermore, it was found that the polarizing plate using the optical film of the present invention is excellent in polarizing plate durability and can suppress deterioration in image quality even when used for a long time under high temperature and high humidity conditions.

  Hereinafter, the cured layer, the surface layer, and the base film of the curable composition of the optical film of the present invention will be described in detail.

<1-1: Cured layer of curable composition> [Compound having an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond]
A compound having an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond can function as a binder.

  By using a compound having an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond, the durability of the polarizing plate can be improved. Although details are not clear, by using a compound having an aliphatic cyclic hydrocarbon group in the molecule, it is possible to prevent the uptake of the molecule from the outside and reduce the ability to diffuse iodine. Moreover, by having an ethylenically unsaturated double bond in a molecule | numerator, a crosslinking point density is raised and the diffusion path | route of the water molecule in an iodine diffusion prevention layer is restrict | limited. Increasing the crosslinking point density also has the effect of relatively increasing the density of the aliphatic cyclic hydrocarbon group, making the cured layer of the aliphatic cyclic hydrocarbon monomer composition more hydrophobic and adsorbing water molecules. It is thought to prevent and reduce moisture permeability.

In order to increase the crosslinking point density, the number of ethylenically unsaturated double bonds in the molecule is more preferably 2 or more.
The aliphatic cyclic hydrocarbon group is preferably a group derived from an alicyclic compound having 7 or more carbon atoms, more preferably a group derived from an alicyclic compound having 10 or more carbon atoms, and further preferably Is a group derived from an alicyclic compound having 12 or more carbon atoms. The aliphatic cyclic hydrocarbon group is particularly preferably a group derived from a polycyclic compound such as bicyclic or tricyclic. More preferably, the central skeleton of the compound described in the claims of JP-A No. 2006-215096, the central skeleton of the compound described in JP-A No. 2001-10999, or the skeleton of an adamantane derivative may be used.

  Specific examples of the aliphatic cyclic hydrocarbon group include a norbornane group, a tricyclodecane group, a tetracyclododecane group, a pentacyclopentadecane group, an adamantane group, and a diamantane group.

  As the aliphatic cyclic hydrocarbon group (including a linking group), a group represented by any one of the following general formulas (I) to (V) is preferable, and the following general formula (I), (II), or (IV) Is more preferable, and a group represented by the following general formula (I) is more preferable.

  In general formula (I), L and L ′ each independently represent a single bond or a divalent or higher linking group. n represents an integer of 1 to 3.

  In general formula (II), L and L ′ each independently represent a single bond or a divalent or higher linking group. n represents an integer of 1 to 2.

  In general formula (III), L and L ′ each independently represent a single bond or a divalent or higher linking group. n represents an integer of 1 to 2.

  In general formula (IV), L and L ′ each independently represent a single bond or a divalent or higher valent linking group, and L ″ represents a hydrogen atom, a single bond or a divalent or higher valent linking group.

In general formula (V), L and L ′ each independently represent a single bond or a divalent or higher linking group.
As the divalent or higher valent linking group for L, L ′ and L ″, an alkylene group having 1 to 6 carbon atoms which may be substituted, an amide bond which may be substituted at the N position, and a substitution at the N position Examples thereof include a urethane bond, an ester bond, an oxycarbonyl group, an ether bond and the like obtained by combining two or more thereof.

Examples of the ethylenically unsaturated double bond include polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group and —C (O) OCH═CH ₂ is preferred. More preferably, a compound containing two or more (meth) acryloyl groups in one molecule described below can be used.

  The compound having an aliphatic cyclic hydrocarbon group and having two or more ethylenically unsaturated double bonds in the molecule has the above-described group having an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond. It is configured by bonding through a linking group.

These compounds include, for example, polyols such as diols and triols having the above aliphatic cyclic hydrocarbon groups, and carboxylic acids and carboxylic acid derivatives of compounds having (meth) acryloyl groups, vinyl groups, styryl groups, allyl groups, etc. It can be easily synthesized by a one-step or two-step reaction with an epoxy derivative, an isocyanate derivative or the like.
Preferably, compounds such as (meth) acrylic acid, (meth) acryloyl chloride, (meth) acrylic anhydride, glycidyl (meth) acrylate, and compounds described in WO2012 / 00316A (eg, 1,1-bis ( (Acryloxymethyl) ethyl isocyanate) can be synthesized by reacting with a polyol having the above cyclic aliphatic hydrocarbon group.

  Hereinafter, although the preferable specific example of the compound which has an aliphatic cyclic hydrocarbon group and has an ethylenically unsaturated double bond is shown, this invention is not limited to these.

[Compound having an ethylenically unsaturated double bond not having an aliphatic cyclic hydrocarbon group]
In the aliphatic cyclic hydrocarbon monomer composition used in the present invention, a compound having an ethylenically unsaturated double bond having no aliphatic cyclic hydrocarbon group in the molecule can be used in combination as long as the effect of the present invention is not impaired. .

  The compound having an ethylenically unsaturated double bond that does not have an aliphatic cyclic hydrocarbon group is preferably a (meth) acrylate compound that does not have an aliphatic cyclic hydrocarbon group. Acrylic acid diesters, (meth) acrylic acid diesters of polyoxyalkylene glycol, (meth) acrylic acid diesters of polyhydric alcohols, (meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts, epoxy (meth) acrylates , Urethane (meth) acrylates, polyester (meth) acrylates, and the like.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. For example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, EO modified Tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate Rate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyurethane polyacrylate, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.

  Commercially available polyfunctional acrylate compounds having a (meth) acryloyl group can be used, such as NK ester A-TMMT manufactured by Shin-Nakamura Chemical Co., Ltd., KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd. Can be mentioned. The polyfunctional monomer is described in paragraphs [0114] to [0122] of JP-A-2009-98658, and the same can be used in the present invention.

The compound having an ethylenically unsaturated double bond that does not have an aliphatic cyclic hydrocarbon group is a compound having a hydrogen bonding substituent, adhesion to the support, low curl, It is preferable from the viewpoint of fixability of fluorine or silicone compounds. The hydrogen-bonding substituent refers to a substituent in which an atom such as nitrogen, oxygen, sulfur, or halogen and a hydrogen bond are bonded by a covalent bond, specifically, —OH, —SH, —NH—, —CHO. , -CONH-, -OCONH- and the like, and urethane (meth) acrylates and (meth) acrylates having a hydroxyl group are preferred. Commercially available polyfunctional acrylates having a (meth) acryloyl group can also be used. Shin Nakamura Chemical Co., Ltd. NK Oligo U4HA, NK Ester A-TMM-3, Nippon Kayaku Co., Ltd. KAYARAD PET-30 etc. can be mentioned.
The content in the case of containing a compound having an ethylenically unsaturated double bond not having an aliphatic cyclic hydrocarbon group is when the total solid content of the aliphatic cyclic hydrocarbon monomer composition is 100% by mass It is preferable that it is 1-30 mass%, 2-20 mass% is more preferable, and 3-15 mass% is still more preferable.

[Other materials contained in the curable composition]
In the range which does not impair the effect of this invention, the curable composition used for this invention is a polymerization initiator, an epoxy monomer, a photo-acid generator (cationic polymerization initiator), a ultraviolet absorber, surfactant, a weather resistance. Various additives such as a property improver, a hardness improver, an antiglare property imparting agent, a slip property imparting agent, and a matting agent, and a solvent can be included.

(Polymerization initiator)
The curable composition of the present invention preferably contains a polymerization initiator. As the polymerization initiator, a radical photopolymerization initiator is preferable.
Photo radical polymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, oximes, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, disulfide compounds, lophine dimers, oniums Examples thereof include salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins. Specific examples, preferred embodiments, commercially available products, and the like of the photopolymerization initiator are described in paragraphs [0133] to [0151] of JP-A-2009-098658, and can be suitably used in the present invention as well. it can.

  “Latest UV Curing Technology” {Technical Information Association, Inc.} (1991), p. 159, and “UV Curing System” written by Kiyomi Kato (published by the General Technology Center in 1989), p. Various examples are also described in 65-148 and are useful in the present invention.

  Commercially available photocleavable photoradical polymerization initiators include “Irgacure 651”, “Irgacure 184”, “Irgacure 819”, “Irgacure 907”, “Irgacure 1870” (CGI-403 / Irgacure 184 = manufactured by BASF) 7/3 mixed initiator), “Irgacure 500”, “Irgacure 369”, “Irgacure 1173”, “Irgacure 2959”, “Irgacure 4265”, “Irgacure 4263”, “Irgacure 127”, “OXE01”, etc .; “Kaya Cure DETX-S”, “Kaya Cure BP-100”, “Kaya Cure BDK”, “Kaya Cure CTX”, “Kaya Cure BMS”, “Kaya Cure 2-EAQ”, “Kaya Cure ABQ”, “Kaya Cure CPTX” manufactured by Yakuhin Co., Ltd. "," “Cure EPD”, “Kaya Cure ITX”, “Kaya Cure QTX”, “Kaya Cure BTC”, “Kaya Cure MCA”, etc .; Etc., and combinations thereof are preferred examples.

  The content of the photopolymerization initiator in the curable composition used in the present invention is such that the polymerizable compound contained in the composition is polymerized and set so that the starting point does not increase excessively. 0.5-8 mass% is preferable with respect to the total solid content in a thing, and 1-5 mass% is more preferable.

〔solvent〕
The curable composition used in the present invention can contain a solvent. Various solvents can be used as the solvent in consideration of the solubility of the monomer, the drying property during coating, and the like. Examples of such organic solvents include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole, phenetole, dimethyl carbonate, carbonic acid. Methyl ethyl, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, Methyl propionate, ethyl propionate, γ-ptyrolactone, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-metho Siethanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, methyl acetoacetate and other methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl Alcohol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol , Hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, tolu Examples thereof include ene and xylene, and these can be used alone or in combination of two or more.

  Of the above solvents, it is preferable to use at least one of dimethyl carbonate, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone (MIBK), acetylacetone, and acetone, and methyl acetate, methyl ethyl ketone, and methyl isobutyl ketone (MIBK). It is more preferable to use either one.

  It is preferable to use a solvent so that the solid content of the curable composition of the present invention is in the range of 20 to 80% by mass, more preferably 30 to 75% by mass, and still more preferably 40 to 70% by mass. It is.

[Thickness of cured layer of curable composition]
The film thickness of the layer obtained by curing the curable composition of the present invention is preferably 0.5 to 25 μm, more preferably 1 to 20 μm, still more preferably 1.5 to 15 μm. It is particularly preferably 10 to 10 μm.
The film thickness of the layer obtained by curing the curable composition can be determined from the difference between the film thicknesses before and after lamination of the cured layer of the aliphatic cyclic hydrocarbon monomer composition on the base film.

[Configuration of layer obtained by curing curable composition, production method]
The cured layer of the curable composition of the present invention may be a single layer or a plurality of layers. The lamination method of the cured layer of the curable composition is not particularly limited, but the cured layer of the aliphatic cyclic hydrocarbon monomer composition is produced as a co-cast with a base film, or the aliphatic cyclic It is preferable to provide a cured layer of a hydrocarbon-based monomer composition on the base film by coating, and to provide a cured layer of the aliphatic cyclic hydrocarbon-based monomer composition on the base film by coating. More preferred.

Although there is no restriction | limiting in particular about the specific method of the process of apply | coating a curable composition, The die-coat coating system using a slot die can be used preferably. Moreover, there is no restriction | limiting in particular about the conveyance speed at the time of application | coating, However, It is preferable to apply | coat on conditions with a conveyance speed of 1-100 m / min. There is no restriction | limiting in particular also about the drying after application | coating, It is preferable to dry for 30 to 1000 second at a drying temperature of 25-140 degreeC.
When performing curing by UV light, the illuminance is preferably 10~5000mW / cm ^2, more preferably 30~3000mW / cm ^2, more preferably 50~1000mW / cm ^2.
In addition, curing with UV light can be performed under air if there is no problem with stickiness of the film surface after curing, but the oxygen concentration during curing is preferably 10 ppm to 20000 ppm, more preferably 50 ppm to 10000 ppm, More preferably, it is 100 ppm to 5000 ppm.
Curing with UV light can be carried out in two or more stages. Moreover, after providing a curable composition and performing UV curing, a surface layer may be provided and UV curing may be performed again. In this case, the integrated amount of illuminance is preferably in the above range.

[Moisture permeability of cured layer of curable composition]
The moisture permeability of the optical film is measured under conditions of 40 ° C. and relative humidity 90% based on JIS Z-0208. From the gas permeation type of the composite film ("Science of Barrier Properties of Packaging Materials (Basic Course of Packaging Science 5)" p68-72 Tsutomu Nakagawa, Japan Packaging Society), J _f the moisture permeability J _s, when the separation of the optical film to the hardened layer of the base film and an aliphatic cyclic hydrocarbon monomer composition, the moisture permeability of the layer formed by curing a curable composition when formed into a J _b The following equation holds.
1 / J _f = 1 / J _s + 1 / J _b (1)
The moisture permeability J _f of the optical film and the moisture permeability J _s of the base film can be directly measured, and the moisture permeability J _b of the layer obtained by curing the curable composition is calculated based on the measured values. Can do.
In this invention, it is preferable that the water vapor transmission rate of the layer which hardened | cured the curable composition is 30-400 g / m < ² > / day.

<1-2: Surface layer>
The surface layer of the present invention contains at least a polyester urethane resin.
[Polyester urethane resin]
The polyester urethane resin of the present invention is a polymer having an ester bond and a urethane bond (—O—CO—NH—) in one molecule.
The monomer used for the synthesis of the polyester urethane resin of the present invention contains at least (U1) diol, (U2) dicarboxylic acid and (U3) diisocyanate. These three types of monomers preferably have (a) hydroxyl (—OH), (b) carboxyl (—COOH) and (c) isocyanate (at each end of a hydrocarbon group having an unbranched structure, respectively. -NCO) is included.
The hydrocarbon group having an unbranched structure is preferably an alkylene group, an alkenylene group, an alkynylene group, an arylene group, or a combination thereof.
The alkylene group, alkenylene group and alkynylene group preferably have a linear structure.
When the hydrocarbon group is an alkylene group, alkenylene group, or alkynylene group, the number of carbon atoms is preferably 1 to 8, more preferably 2 to 6, and most preferably 2 to 4. .
The arylene group may have an alkyl group having 1 to 8 carbon atoms as a substituent.
The arylene group is preferably a phenylene group or a naphthylene group, more preferably a phenylene group, and most preferably a p-phenylene group.
As the hydrocarbon group, the alkylene group, the arylene group, or a combination thereof is particularly preferable.

(U1) Diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and 1,5-pentanediol. preferable.
(U2) As the dicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, oxalic acid and malonic acid are preferable.
(U3) Diisocyanates include ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, m-xylylene diisocyanate, p-phenylene diisocyanate. , Tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate and 1,5-naphthalene diisocyanate are preferred.

The number average molecular weight (Mn) of the polyester urethane resin is preferably in the range of 2,000 to 100,000, and more preferably in the range of 5,000 to 50,000. The number average molecular weight (Mn) in the present invention is a number average molecular weight in terms of polystyrene measured by GPC.
The content of the polyester urethane resin is used in the range of 25 to 100% by mass with respect to the total solid content when the total solid content of the composition for the surface layer is 100% by mass. It is preferably 30 to 80% by mass, and more preferably 35 to 75% by mass.
Examples of commercially available polyester urethane include Byron series (trade name): manufactured by Toyobo Co., Ltd., Byron UR-1510, Byron UR-1700, Byron UR-2300, Byron UR-3200, Byron UR-3210, Byron UR-3260, Byron UR-3500, Byron UR-6100, Byron UR-8300, Byron UR-8700 and the like can be preferably used.

[Other materials included in surface layer composition]
Furthermore, the composition for the surface layer is (meth) acrylic monomer, radical photopolymerization initiator, epoxy monomer, photoacid generator (cationic polymerization initiator), ultraviolet absorber, surfactant, weather resistance improver, hardness improvement Various additives and solvents such as an agent, an antiglare imparting agent, a slipperiness imparting agent, and a matting agent can be included.

[Film thickness of surface layer]
The film thickness of the surface layer of the present invention is preferably 0.05 to 2.5 μm, and more preferably 0.1 to 1.0 μm.

<The process of apply | coating the composition for surface layers>
The specific method of the process of apply | coating the composition for surface layers is the same as the process of applying a curable composition, and its preferable range is also the same.
In addition, curing with UV light may or may not be performed. When performed, it is the same as the step of applying the curable composition, and the preferred range is also the same.

<Iodine diffusion prevention layer>
In the optical film of the present invention, the cured layer of the curable composition and the surface layer may be combined and referred to as an iodine diffusion preventing layer.
When the compound represented by the general formula (I) is used as the compound having an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond, the effect can be more exhibited.

<1-3. Base film>
[Material of base film]
As a material for forming the base film, a polymer excellent in optical performance transparency, mechanical strength, thermal stability, isotropy and the like is preferable. The term “transparent” as used in the present invention indicates that the visible light transmittance is 60% or more, preferably 80% or more, and particularly preferably 90% or more. Examples include polycarbonate polymers, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, (meth) acrylic polymers such as polymethyl methacrylate, and styrene polymers such as polystyrene and acrylonitrile / styrene copolymers (AS resin). It is done. Polyolefins such as polyethylene and polypropylene, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers, polyethersulfone polymers Examples thereof include polyether ether ketone polymers, polyphenylene sulfide polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, and polymers obtained by mixing the above polymers. The polymer film of the present invention can also be formed as a cured layer of an ultraviolet-curable or thermosetting resin such as acrylic, urethane, acrylic urethane, epoxy, or silicone.

  In addition, as a material for forming the base film, a cellulose polymer (particularly preferably, cellulose acylate) represented by triacetyl cellulose, which has been conventionally used as a transparent protective film of a polarizing plate, is preferably used. it can.

[Cellulose acylate]
As the cellulose acylate film, for example, those described in paragraph numbers [0072] to [0075] of JP2013-228720A can be used.

[Other additives]
Additives such as UV absorbers, matting agents, retardation developing agents, plasticizers, UV absorbers, deterioration inhibitors, release agents, infrared absorbers, wavelength dispersion adjusting agents can be added to the base film. , They may be solid or oily. That is, the melting point and boiling point are not particularly limited. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when an optical film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ.

  The base film may contain rubber-like particles. Examples thereof include acrylic particles such as a soft acrylic resin, acrylic rubber, and rubber-acrylic graft type core-shell polymer, or a styrene-elastomer copolymer. Furthermore, additives that improve impact resistance and stress whitening resistance described in JP-B-60-17406, JP-B-3-39095 and the like are also preferably used.

In the said base film, when adding these additives, it is preferable that the total amount of an additive is 50 mass% or less with respect to a base film, and it is more preferable that it is 30 mass% or less.
These additives improve the brittleness of the film and greatly improve the folding resistance test of the film (e.g., crack evaluation when bent 180 degrees).
In order to achieve low haze, the refractive index of the additive preferably has substantially the same refractive index as the base film, and the refractive index difference is preferably 0.5 or less, more preferably 0.3 or less. preferable.

[Characteristics of base film]
(Base film thickness)
The film thickness of the substrate film is preferably 5 to 100 μm, more preferably 10 to 80 μm, particularly preferably 15 to 70 μm, and particularly preferably 20 to 60 μm.

(surface treatment)
The base film is optionally surface-treated to achieve improved adhesion between the base film and the cured layer of the curable composition or other layers (eg, polarizer, subbing layer and back layer). can do. For example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment here may be low-temperature plasma that occurs in a low pressure gas of 10 ^{−3 to} 20 Torr, and plasma treatment under atmospheric pressure is also preferable. A plasma-excitable gas is a gas that is plasma-excited under the above conditions, and includes chlorofluorocarbons such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, tetrafluoromethane, and mixtures thereof. It is done. Details of these are described in detail in pages 30 to 32 in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention), and are preferably used in the present invention. be able to.
By similarly surface-treating the cured layer and the surface layer of the curable composition, the adhesion of each layer can be improved.

<1-4. Functional layer>
The optical film of the present invention can be provided with a functional layer according to the purpose as desired. Examples of the functional layer include a hard coat layer, an antireflection layer, a light scattering layer, an antifouling layer, an antistatic layer, and the like, and these layers may also have a plurality of functions.
From the viewpoint of enhancing the effects of the present invention, these layers are preferably provided on the surface of the base film opposite to the cured layer of the aliphatic cyclic hydrocarbon monomer composition.

<< 2. Polarizing plate >>
The polarizing plate of the present invention includes a polarizer and at least one optical film of the present invention.
The polarizing plate of the present invention comprises a polarizer and at least one optical film of the present invention disposed on one side of the polarizer. In general, a polarizing plate in which both sides of a polarizer are sandwiched between polarizing plate protective films and the both sides are protected is widely used.
In addition, when it has a polarizing plate protective film on both sides of a polarizer, it may have a polarizing plate protective film different from the optical film of the present invention on the surface opposite to the surface having the optical film of the present invention. A known polarizing plate protective film may be included.
For example, the polarizing plate protective film different from the optical film of the present invention includes additives or types thereof, those having different contents, those having different properties, those having different functional layers, those having different functional layers, and the like. .

<2-1: Polarizer>
The polarizer is composed of at least a dichroic dye and a resin.

[resin]
A polyvinyl alcohol resin is preferably used for the polarizer of the present invention. The polarizer in the present invention contains a polyvinyl alcohol resin as a main component, and usually occupies 80% by mass or more of the polarizer. Polyvinyl alcohol is usually a saponified polyvinyl acetate, but may contain components copolymerizable with vinyl acetate such as unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, and vinyl ethers. Absent. A modified polyvinyl alcohol resin containing an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group, or the like can also be used.

  The degree of saponification of the polyvinyl alcohol-based resin is not particularly limited, but is preferably 80 to 100 mol%, particularly preferably 90 to 100 mol% from the viewpoint of solubility and the like. Moreover, although the polymerization degree of polyvinyl alcohol-type resin is not specifically limited, 1,000-10,000 are preferable and 1,500-5,000 are especially preferable.

The elastic modulus of the polyvinyl alcohol-based resin film before stretching is preferably 0.1 MPa or more and 500 MPa or less, more preferably 1 MPa or more and 100 MPa or less when expressed in Young's modulus.
By setting it as such a range, the polyvinyl alcohol-type resin film which is excellent in the wrinkle generation | occurrence | production suppression effect after extending | stretching, and has sufficient intensity | strength can be manufactured.

  Although the thickness of the polyvinyl alcohol-type resin film before extending | stretching is not specifically limited, From a viewpoint of stability of film holding | maintenance and the uniformity of extending | stretching, 1 micrometer-1 mm are preferable and 20-200 micrometers is especially preferable. The film thickness of the stretched polyvinyl alcohol-based resin film is preferably 2 to 100 μm, and 7 to 25 μm is preferable for improving light leakage. This thickness determines the thickness of the polarizer film.

[Dichroic dye]
The polarizer of the present invention contains a dichroic dye. Here, the dichroic dye refers to a dye having different absorbance depending on the direction, and includes iodine ion, diazo dye, quinone dye, and other known dichroic dyes. The dichroic dye, I ₃ ^- and I ₅ ^- can be preferably used an iodine ion or a dichroic dye higher such.
In the present invention, higher-order iodine ions are particularly preferably used. Higher-order iodine ions can be found in “Applications of Polarizing Plates” by Ryo Nagata, CMC Publishing and Industrial Materials, Vol. 28, No. 7, p. 39-p. As described in No. 45, polyvinyl alcohol can be immersed in a solution obtained by dissolving iodine in a potassium iodide aqueous solution and / or a boric acid aqueous solution and adsorbed and oriented in polyvinyl alcohol.

  As content of a dichroic pigment | dye, 0.1-50 mass parts is preferable with respect to polyvinyl alcohol-type resin, 0.5-20 mass parts is more preferable, 1.0-5.0 mass parts is further more preferable. .

  In addition to the polyvinyl alcohol resin and the dichroic dye, the polarizer of the present invention may contain a plasticizer and a surfactant as necessary.

<2-2: Manufacturing method of polarizer>
As a method for producing the polarizer of the present invention, for example, it is preferable to form a polarizer by introducing a film of a polyvinyl alcohol-based resin and then introducing iodine. The production of the polyvinyl alcohol-based resin film is performed by the method described in paragraph Nos. 0213 to 0237 of JP-A-2007-86748, JP-A-3342516, JP-A-09-328593, JP-A-2001-302817, This can be done with reference to Japanese Unexamined Patent Publication No. 2002-144401.

  In the present invention, in particular, a step of forming a polyvinyl alcohol-based resin solution having a polyvinyl alcohol-based resin into a film, a step of stretching a polyvinyl alcohol-based resin film, and a polyvinyl alcohol-based resin film after stretching with a dichroic dye And a step of crosslinking the polyvinyl alcohol resin film after dyeing with boric acid.

<2-3: Shape and configuration>
The shape of the polarizing plate of the present invention is not only a polarizing plate in the form of a film piece cut into a size that can be incorporated into a display device as it is, but also produced in a long shape by continuous production and rolled up into a roll shape. The polarizing plate of the aspect (for example, aspects with a roll length of 2500 m or more or 3900 m or more) is also included. In order to use for a large-screen liquid crystal display device, the width of the polarizing plate is preferably 1470 mm or more.

The polarizing plate of the present invention is composed of a polarizer and at least one optical film of the present invention. Further, a protective film (not the optical film of the present invention) is provided on one side of the polarizing plate, and the opposite side is provided. It is also preferable that a separate film is laminated.
The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the contact bonding layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.

<2-4: Laminating method of polarizer and optical film>
The polarizing plate of the present invention can be produced by laminating at least one optical film of the present invention on at least one surface of the polarizer obtained above. When laminating, it is preferable to use an adhesive layer.
The polarizing plate of the present invention is preferably prepared by a method of applying an adhesive composition to a surface of an optical film, applying the adhesive composition, bonding the resultant to a polarizer, irradiating ultraviolet rays, and curing the resin.
Examples of the adhesive used in the adhesive composition for the adhesive layer for bonding the treated surface of the optical film and the polarizer include JP 2012-140610 A, JP 2012-208250 A, JP Examples of known adhesives described in JP-A-2015-203733.

Among these, it is preferable that an epoxy material is included, and it is particularly preferable that the epoxy material is an epoxy compound having a cycloaliphatic epoxy group or a glycidyl compound. Specific examples include the following.
Celoxide 8000, Celoxide 2021P, Cyclomer M100, EHPE3150 (manufactured by Daicel Co., Ltd.), TTA20, TTA22, TTA27 (manufactured by Tetrachem), Ricaresin DME-100, Ricaresin HBE-100, (Shin Nippon Rika Co., Ltd.) Celoxide 8000, Celoxide 2021P, TTA22, and Rica Resin DME-100 are preferable.

[Other materials]
The adhesive composition containing the epoxy-based material preferably contains a photocationic polymerization initiator. Preferred examples of the cationic photopolymerization initiator include compounds that generate cationic species and Lewis acids upon irradiation with active energy rays, such as onium salts such as aromatic diazonium salts, aromatic iodonium salts and aromatic sulfonium salts, iron -An allene complex etc. can be mentioned.
Furthermore, the adhesive containing an epoxy-based material may contain other additives such as an oxetane compound, an acrylic monomer, a photo radical polymerization initiator, a sensitizer, a surfactant, and a solvent.

  The optical film of the present invention is preferably bonded so that the layer obtained by curing the curable composition is on the side close to the polarizer. The above configuration is preferable because diffusion of iodines to the outside of the polarizer can be effectively suppressed, and the polarization performance is hardly deteriorated when stored in a high temperature and high humidity environment for a long period of time.

<2-5: Functionalization of polarizing plate>
The polarizing plate of the present invention is a functionalized polarized light combined with a polarizing plate protective film having functional layers such as an antireflection film, a brightness enhancement film, a forward scattering layer, an antiglare (antiglare) layer, etc. for improving visibility of the display. It is also preferably used as a plate. The antireflection film, the brightness enhancement film, the other functional optical film, the forward scattering layer, and the antiglare layer for functionalization are described in paragraph numbers 0257 to 0276 of Japanese Patent Application Laid-Open No. 2007-86748. A functionalized polarizing plate can be produced.

<2-6: Performance of polarizing plate>
[Degree of polarization]
The polarizing plate of the present invention preferably has a degree of polarization of 95% or more, more preferably 98% or more, and most preferably 99.5% or more.

  In the present invention, the polarization degree of the polarizing plate is determined by the following formula from the orthogonal transmittance and the parallel transmittance measured at a wavelength of 380 nm to 700 nm using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation. And further calculating the weighted average of the light source (auxiliary illuminant C) and the CIE visibility (Y).

Polarization degree (%)
= {(Parallel transmittance−Orthogonal transmittance) / (Parallel transmittance + Orthogonal transmittance)} ^1/2 × 100

[Polarizing plate durability]
The polarizing plate of the present invention is excellent in polarizing plate durability under wet heat aging conditions. For this reason, the amount of change in the degree of polarization before and after the polarizing plate durability test is small.
The polarizing plate of the present invention measures orthogonal transmittance and parallel transmittance using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation, and calculates the degree of polarization by the above formula. It is preferable that the amount of change in polarization degree is less than 1% when stored for 720 hours in an environment of 85% humidity.

  Two samples (5 cm × 5 cm) in which the polarizing plate of the present invention is bonded onto glass through an adhesive are prepared. Under the present circumstances, it sticks so that the polarizing plate protective film of this invention may become the glass side. The orthogonal transmittance measurement is performed by setting the glass side of the sample facing the light source. Each of the two samples is measured, and the average value is defined as the orthogonal transmittance and the parallel transmittance. Specifically, it is as described in the examples.

[Other characteristics]
Other preferable optical characteristics and the like of the polarizing plate of the present invention are described in paragraph numbers 0238 to 0255 of JP-A-2007-086748, and it is preferable to satisfy these characteristics.

<< 3. Image display device >>
Examples of the image display device according to one embodiment of the present invention include a liquid crystal display device and an antireflection application of an organic electroluminescence display device.
If a liquid crystal display device is demonstrated as an example, the liquid crystal display device of this invention will have a liquid crystal cell and the polarizing plate of this invention at least. The liquid crystal display device has a configuration in which a liquid crystal cell is disposed between two polarizing plates like a first polarizing plate and a second polarizing plate. The driving mode of the liquid crystal cell is not particularly limited, but each driving mode such as TN, OCB, VA, IPS is generally used. Furthermore, it is preferable to use an optically anisotropic layer that performs optical compensation in accordance with the driving mode of the liquid crystal cell, and is disposed between the liquid crystal cell and the polarizing plate. In addition, the polarizing plate protective film may have the function of the optically anisotropic layer.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Production of Reference Example 101]
<Preparation of cellulose acylate>
A cellulose acylate having an acetyl substitution degree of 2.87 was prepared. This was carried out by adding sulfuric acid (7.8 parts by mass with respect to 100 parts by mass of cellulose) as a catalyst, adding carboxylic acid as a raw material for the acyl substituent, and carrying out an acylation reaction at 40 ° C. In addition, aging was performed at 40 ° C. after acylation. Further, the low molecular weight component of the cellulose acylate was removed by washing with acetone.

<Preparation of dope 101 solution for air side surface layer>
(Preparation of cellulose acylate solution 1)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution 101.
―――――――――――――――――――――――――――――――――――
Composition of Cellulose Acylate Solution 1 ――――――――――――――――――――――――――――――――――――
Cellulose acetate with an acetyl substitution degree of 2.87 and a polymerization degree of 370
100.0 parts by mass Sucrose benzoate (benzoyl substitution degree 5.5)
6.0 parts by mass Sucrose acetate isobutyrate manufactured by Sigma-Aldrich
4.0 parts by weight Methylene chloride (first solvent) 353.9 parts by weight Methanol (second solvent) 89.6 parts by weight n-butanol (third solvent) 4.5 parts by weight ――――――――― ――――――――――――――――――――――――――

(Preparation of matting agent solution 2)
The following composition was charged into a disperser and stirred to dissolve each component to prepare a matting agent solution 2.
―――――――――――――――――――――――――――――――――――
Composition of Matte Solution 2 ―――――――――――――――――――――――――――――――――――
Silica particles having an average particle size of 20 nm (AEROSIL R972,
Nippon Aerosil Co., Ltd.) 2.0 parts by weight Methylene chloride (first solvent) 69.3 parts by weight Methanol (second solvent) 17.5 parts by weight n-butanol (third solvent) 0.9 parts by weight The above cellulose Acylate solution 1 0.9 parts by mass ―――――――――――――――――――――――――――――――――――

  1.3 parts by mass of the matting agent solution 2 and 98.7 parts by mass of the cellulose acylate solution 1 were added and mixed using an in-line mixer to prepare an air-side surface dope 101 solution.

<Preparation of base layer dope 102>
(Preparation of cellulose acylate 3 solution)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a base layer dope 102.
―――――――――――――――――――――――――――――――――――
Composition of base layer dope 102 (cellulose acylate solution 3) ―――――――――――――――――――――――――――――――――――
Cellulose acetate with an acetyl substitution degree of 2.87 and a polymerization degree of 370
100.0 parts by mass Sucrose benzoate (benzoyl substitution degree 5.5)
6.0 parts by mass Sucrose acetate isobutyrate manufactured by Sigma-Aldrich
4.0 parts by mass The following UV absorber C 2.0 parts by mass Methylene chloride (first solvent) 297.7 parts by mass Methanol (second solvent) 75.4 parts by mass n-butanol (third solvent) 3.8 parts by mass Department ――――――――――――――――――――――――――――――――――――
UV absorber C

<Preparation of dope 103 solution for support surface layer>
1.3 parts by mass of the matting agent solution 2 and 99.3 parts by mass of the cellulose acylate solution 1 prepared in the air layer side surface dope 101 liquid were mixed using an in-line mixer, and the support side surface dope 103 was mixed. A liquid was prepared.

<Formation of base film>
(Casting)
Using a drum casting apparatus, the above-prepared dope (base layer dope) and the surface layer dope on both sides of the dope are made uniformly into a stainless steel casting support (support temperature -9 ° C) from the casting port. It was cast into. Stripped in a state where the amount of residual solvent in the dope of each layer is about 70% by mass, fixed both ends in the width direction of the film with a pin tenter, and 1.28 in the lateral direction in a state of residual solvent amount of 3-5% by mass. The film was dried while being stretched twice. Then, it dried further by conveying between the rolls of the heat treatment apparatus, and the cellulose acylate film of Reference Example 101 was obtained. The thickness of the cellulose acylate film as the obtained base film was 60 μm (air side surface layer 3 μm, base layer 54 μm, support side surface layer 3 μm), and the width was 1480 mm.

[Production of Example 101]
(1) Optical film having a layer obtained by curing a curable composition and a surface layer <Preparation of curable composition (A-1)>
Curable composition A-1 was prepared with the composition shown below, and prepared by filtering through a polypropylene filter having a pore size of 30 μm.

―――――――――――――――――――――――――――――――――――
Composition of Curable Composition A-1 ――――――――――――――――――――――――――――――――――――
Compound having aliphatic cyclic hydrocarbon group and ethylenically unsaturated double bond: A-DCP [manufactured by Shin-Nakamura Chemical Co., Ltd.] 100.7 parts by mass Irgacure 127 [manufactured by BASF] 2.1 parts by mass Surface activity Agent A 0.02 parts by weight Methyl ethyl ketone 29.2 parts by weight Methyl isobutyl ketone 19.4 parts by weight Methyl acetate 48.6 parts by weight ――――――――――――――――――――― ―――――――――――――

  Surfactant A is the following compound.

<Preparation of surface layer composition (B-1)>
Surface layer composition B-1 was prepared with the composition shown below, filtered through a polypropylene filter having a pore size of 30 μm, and adjusted.

―――――――――――――――――――――――――――――――――――
Composition of surface layer composition B-1 ――――――――――――――――――――――――――――――――――――
Polyester urethane resin: Byron UR-1510
(Methyl ethyl ketone solution with a solid content of 30% by mass)
[Toyobo Co., Ltd.] 11.7 parts by mass Methyl ethyl ketone 20.7 parts by mass Methyl isobutyl ketone 67.5 parts by mass ――――――――――――――――――――――― ――――――――――――

<Formation of cured layer of curable composition>
On the surface of the base film described above in Reference Example 101 on the side of the casting support, the curable composition (A-1) is applied by a microgravure coating method under conditions of a conveyance speed of 30 m / min, and 60 ° C. For 120 seconds, and under a nitrogen purge, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with an oxygen concentration of about 100 ppm and a base film temperature of 25 ° C., an illuminance of 400 mW / The coating layer was cured by irradiating with an ultraviolet ray of cm ² and an irradiation amount of 100 mJ / cm ² to form a cured layer of a curable composition having a thickness of 5 μm.

(Oxygen concentration)
The oxygen concentration was determined by measuring the concentration in the exposure apparatus using an oxygen concentration meter OX-102 (manufactured by Yokogawa Electric Corporation).

<Formation of surface layer>
The film provided with a layer obtained by curing the obtained curable composition is in contact with the cured layer of the curable composition, and the surface layer composition (B-1) is transported at a speed of 30 m / min by a microgravure coating method. After coating at 60 ° C. and drying for 120 seconds, an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm with an oxygen concentration of about 100 ppm and a substrate film temperature of 25 ° C. under a nitrogen purge. ), Irradiating ultraviolet rays with an illuminance of 400 mW / cm ² and an irradiation amount of 300 mJ / cm ² to cure the cured layer of the curable composition and the coating layer of the composition for the surface layer including the polyester urethane resin, A surface layer containing a 0.1 μm thick polyester urethane resin in contact with the cured layer of the curable composition was formed. The obtained optical film was used as the optical film of Example 101.

(2) Production of polarizing plate <Preparation of composition C-1 for adhesive layer>
Each component was mixed with the composition shown below and stirred at 50 ° C. for 1 hour to obtain an adhesive layer composition C-1.
―――――――――――――――――――――――――――――――――――
Composition of Composition C-1 for Adhesive Layer ―――――――――――――――――――――――――――――――――――
Celoxide 2021P [manufactured by Daicel Corporation] 25.0 parts by mass Aron oxetane OXT-221 [manufactured by Toagosei Co., Ltd.] 50.0 parts by mass Rica Resin DME-100 [manufactured by Shin Nippon Rika Co., Ltd.] 25.0 parts by mass Photocationic polymerization initiator: CPI-100P [manufactured by San Apro]
5.0 Mass parts ――――――――――――――――――――――――――――――――――――

<Production of polarizer>
A polyvinyl alcohol film having an average polymerization degree of 2400, a saponification degree of 99.9 mol%, and a thickness of 75 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Subsequently, the film was stretched to 3.5 times while dyeing in an iodine solution of 0.3 wt% (weight ratio: iodine / potassium iodide = 0.5 / 8) at 30 ° C. for 1 minute. Thereafter, the total draw ratio was stretched to 6 times while being immersed in a 4% by weight boric acid aqueous solution at 65 ° C. for 0.5 minutes. After stretching, drying was performed in an oven at 70 ° C. for 3 minutes to obtain a polarizer having a thickness of 26 μm. The moisture content of the polarizer was 13.5% by weight.

<Lamination>
The surface layer side of the optical film produced in Example 101 was subjected to corona treatment (9.4 kJ / m ² ). On the surface of the surface layer subjected to the corona treatment, the composition C-1 for adhesive layer prepared above is MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, number of gravure roll lines: 1000 / INCH, rotation) The film was applied to a thickness of 0.5 μm using a speed of 140% / line speed).
In addition, for the cycloolefin film having a thickness of 40 μm (Arton RX4500 manufactured by JSR), the adhesion prepared as described above was applied to the surface of the cycloolefin film subjected to the corona treatment after the corona treatment. The agent layer composition C-1 was applied to a thickness of 0.5 μm.
Then, the surface which apply | coated the composition C-1 for adhesive bond layers was bonded together to the one side surface of a polarizer, respectively. Thereafter, both film surfaces were heated to 50 ° C. using an IR heater from both sides of the laminated film (optical film of Example 101 / polarizer / cycloolefin-based film structure). The active energy rays shown below were irradiated to cure the adhesive layer composition C-1. Thereafter, it was dried with hot air at 70 ° C. for 3 minutes to obtain a polarizing plate 101.

(Active energy rays)
As an active energy ray, an ultraviolet ray (gallium sealed metal halide lamp) irradiation device: Fusion UV Systems, Inc. Light HAMMER10 bulb: V bulb Peak illuminance: 1600 mW / cm ² , integrated irradiation amount 1000 mJ / cm ² (wavelength 380 to 440 nm) used. In addition, the illumination intensity of the ultraviolet-ray was measured using the Sola-Check system by Solatell.

[Production of Examples 102 to 112 and Comparative Examples 113 and 114]
In the same manner as in Example 101, using the surface layer compositions B-2 to B-10 having the composition described in Table 1, the film thickness, irradiation amount, oxygen concentration, and active energy ray curable adhesion described in Table 1 The optical film of Examples 102-112 and Comparative Examples 113 and 114 was produced with the agent composition. Furthermore, the polarizing plates of Examples 102 to 112 and Comparative Examples 113 and 114 were obtained in the same manner as the polarizing plate 101 produced in Example 101.

-Byron UR-1700: Polyester urethane resin (methyl ethyl ketone solution having a solid content of 30% by mass) [manufactured by Toyobo Co., Ltd.]
Byron UR-3500: Polyester urethane resin (methyl ethyl ketone / toluene (mass ratio: 82/18) solution having a solid content of 40% by mass) [manufactured by Toyobo Co., Ltd.]
MEK-AC-4130Y: particle size; 40-50 nm organosilica sol (methyl ethyl ketone dispersion having a solid content of 30% by mass) [manufactured by Nissan Chemical Co., Ltd.]
MEK: methyl ethyl ketone MiBK: methyl isobutyl ketone Surfactant B: the following compounds (ratio is molar ratio)

Composition of Composition C-2 for Adhesive Layer ―――――――――――――――――――――――――――――――――――
Composition of Composition C-2 for Adhesive Layer ―――――――――――――――――――――――――――――――――――
Celoxide 2021P [manufactured by Daicel Corporation] 59.0 parts by mass Aron Oxetane OXT-221 [manufactured by Toagosei Co., Ltd.] 5.0 parts by mass Light acrylate 1,6HX-A [manufactured by Kyoeisha Chemical Co., Ltd.]
30.0 parts by mass Photocationic polymerization initiator: CPI-100P [manufactured by San Apro]
5.0 parts by mass Photoradical polymerization initiator: Irgacure 184 [manufactured by BASF] 1.0 parts by mass ――――――――――――――――――――――――――― ―――――――

[Evaluation]
<Peeling force evaluation>
Each polarizing plate of each Example and Comparative Example produced above was bonded on a glass plate via an adhesive so that the optical film side of the present invention of each polarizing plate was directed to the glass plate side. The size of each polarizing plate was 2.5 cm wide × 15 cm long, and the length of the bonded portion was 7 cm.
A trigger for separation (width: 25 mm, length: 10 mm) was made with a razor at the interface between the optical film attached to the glass and the polarizer so as to be parallel to the direction of the interface. Thereafter, the member on the polarizer side is oriented in the 90 ° direction so as to peel off the optical film attached to the glass and the member on the polarizer side (for example, in the case of the polarizing plate 101, the laminated polarizer and the cycloolefin film). Interfacial peeling was advanced by pulling the polarizing plate in the vertical direction when placed on a horizontal desk, and only the film edge was peeled off. The load at this time was measured, and this value was defined as the delamination force (N / 25 mm). Tensilon (RTG-1310, manufactured by A & D Co., Ltd.) was used for peeling, and the peeling speed was 300 mm / min. Evaluation was made according to the following criteria, and the results are shown in Table 2.
A: When the delamination force exceeds 3.0 N / 25 mm B: When the delamination force is 1.5 to 3 N / 25 mm C: When the delamination force is less than 1.5 N / 25 mm

(Polarizing plate durability)
About the polarizing plate of each Example produced above and a comparative example, polarization degree was measured and polarizing plate durability was evaluated.
Thereafter, the degree of polarization was measured by the same method even after storage for 720 hours in an environment of 85 ° C. and 85% relative humidity. The degree of polarization before and after aging was determined and evaluated according to the following criteria, and the results are shown in Table 2 below as the polarizing plate durability.
A: Polarization degree change amount is less than 0.1% B: Polarization degree change amount is 0.1% or more and less than 1% C: Polarization degree change amount is 1 or more and less than 5% D: Polarization degree change amount is 5% or more

In Comparative Examples 113 and 114, during polarizing plate durability evaluation, a part of the polarizing plate and the optical film were peeled off, and a portion with a large change in polarization degree and a portion with a small change in polarization degree were mixed. The part D was mixed.

  From the results of Table 2, the polarizing plates of Examples 101 to 112 using the optical film of the present invention have a greater delamination force between the optical film and the polarizer than the polarizing plates of Comparative Examples 113 and 114, and In addition, it does not peel off during durability evaluation and has excellent adhesion. Further, even when stored in a high temperature and high humidity environment, the change in polarization degree is small, and the polarizing plate durability under wet heat aging conditions is excellent.

DESCRIPTION OF SYMBOLS 1 Base film 2 Cured layer 3 of curable composition Surface layer 4 Adhesive layer 5 Polarizer

Claims (7)

  An optical film having a cured layer of a curable composition and a surface layer in this order on a base film, wherein the curable composition has at least an aliphatic cyclic hydrocarbon group and an ethylenically unsaturated double bond. An optical film comprising: a compound having a surface layer, wherein the surface layer includes at least a polyester urethane resin. The optical film according to claim 1, wherein the aliphatic cyclic hydrocarbon group is a group represented by the following general formula (I).

In general formula (I), L and L ′ each independently represent a single bond or a divalent or higher linking group, and n represents an integer of 1 to 3.   The optical film according to claim 1, wherein the substrate film is a cellulose acylate film.   A polarizing plate comprising a polarizer and at least one optical film according to claim 1.   The polarizing plate according to claim 4, wherein the surface layer of the optical film is disposed on the polarizer side.   6. The polarizing plate according to claim 4, wherein the surface layer is in contact with a polarizer through an adhesive layer containing an epoxy material. An image display device comprising a liquid crystal cell and the polarizing plate according to claim 4 disposed in at least one of the liquid crystal cells.

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