JP2016102918A - Polarizing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate in which a stretched protective film and a polarizer are laminated with good adhesiveness.SOLUTION: The polarizing plate includes a stretched protective film disposed via an adhesive layer on at least one surface of a polarizer. The adhesive layer is a cured product of a composition that contains, as a curable component, a (meth)acrylamide compound having no hydroxyl group by greater than 35 mass% and contains substantially no (meth)acrylamide compound having a hydroxyl group.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polarizing plate.

  Patent Document 1 describes an adhesive containing 10% by weight of N-hydroxyethylacrylamide, 70% by weight of N, N-dimethylacrylamide and 20% by weight of 2-hydroxyethyl methacrylate as a curable component, A polarizing plate is described in which a protective film and a polarizing film are bonded together via the adhesive. However, Patent Document 1 does not describe any stretched protective film.

JP 2013-178466 A

  There has been a demand for a polarizing plate in which a stretched protective film and a polarizer are bonded with good adhesion.

［式（１）中、Ｑ^１は、水素原子又はメチル基を表す。
Ｑ^２及びＱ^３は、それぞれ独立して、水素原子、炭素数１〜６のアルコキシ基又はアミノ基を有していてもよい炭素数１〜６のアルキル基を表すか、あるいはＱ^２とＱ^３とが互いに結合して、それらが結合する窒素原子とともに、環を形成してもよい。］
［４］接着剤層が、さらに多官能ウレタン（メタ）アクリレート化合物を含む組成物の硬化物であって、
該組成物中の多官能ウレタン（メタ）アクリレート化合物の含有量が、水酸基を有さない（メタ）アクリルアミド化合物１００質量部に対して、１０〜４５質量部である［１］〜［３］のいずれかに記載の偏光板。
［５］接着剤層が、さらに多官能（メタ）アクリレートモノマーを含む組成物の硬化物であって、
該組成物中の多官能（メタ）アクリルモノマーの含有量が、水酸基を有さない（メタ）アクリルアミド化合物１００質量部に対して、１〜４５質量部である［１］〜［４］のいずれかに記載の偏光板。
［６］接着剤層が、硬化性成分として、さらに単官能（メタ）アクリレートモノマーを１〜４０質量％含む組成物の硬化物である［１］〜［５］のいずれかに記載の偏光板。
［７］延伸された保護フィルムが、（メタ）アクリル樹脂からなる［１］〜［６］のいずれかに記載の偏光板。
［８］硬化性成分として、水酸基を有さない（メタ）アクリルアミド化合物を３５質量％より多く含み、水酸基を有する（メタ）アクリルアミド化合物を実質的に含有しない、延伸された保護フィルム用の接着剤組成物。
［９］さらに、多官能ウレタン（メタ）アクリレート化合物を含む接着剤用組成物であって、
該組成物中の多官能ウレタン（メタ）アクリレートモノマーの含有量が、水酸基を有さない（メタ）アクリルアミド化合物１００質量部に対して、１０〜４５質量部である［８］に記載の接着剤用組成物。
［１０］さらに、多官能（メタ）アクリレートを含む接着剤用組成物であって、
該組成物中の多官能（メタ）アクリルモノマーの含有量が、水酸基を有さない（メタ）アクリルアミド化合物１００質量部に対して、１〜４５質量部である［８］又は［９］に記載の接着剤用組成物。 The present invention includes the following inventions.
[1] A polarizing plate in which a stretched protective film is provided on at least one surface of a polarizer via an adhesive layer,
Polarized light which is a cured product of a composition in which the adhesive layer contains more than 35% by mass of a (meth) acrylamide compound having no hydroxyl group as a curable component and does not substantially contain a (meth) acrylamide compound having a hydroxyl group Board.
[2] The polarizing plate according to [1], wherein the adhesive layer is a cured product of a composition containing 55 to 90% by mass of a (meth) acrylamide compound having no hydroxyl group.
[3] The polarizing plate according to [1] or [2], wherein the (meth) acrylamide compound having no hydroxyl group is a compound represented by the formula (1).

Wherein (1), ^{Q 1} represents a hydrogen atom or a methyl group.
Q ² and Q ³ each independently represent a hydrogen atom, an alkoxy group having 1 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms which may have an amino group, or Q ² and Q 3 ³ may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. ]
[4] The adhesive layer is a cured product of a composition further comprising a polyfunctional urethane (meth) acrylate compound,
The content of the polyfunctional urethane (meth) acrylate compound in the composition is 10 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. The polarizing plate in any one.
[5] The adhesive layer is a cured product of a composition further containing a polyfunctional (meth) acrylate monomer,
Any of [1] to [4], wherein the content of the polyfunctional (meth) acrylic monomer in the composition is 1 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. The polarizing plate of crab.
[6] The polarizing plate according to any one of [1] to [5], wherein the adhesive layer is a cured product of a composition further containing 1 to 40% by mass of a monofunctional (meth) acrylate monomer as a curable component. .
[7] The polarizing plate according to any one of [1] to [6], wherein the stretched protective film is made of a (meth) acrylic resin.
[8] Adhesive for stretched protective film containing as a curable component more than 35% by mass of a (meth) acrylamide compound having no hydroxyl group and substantially not containing a (meth) acrylamide compound having a hydroxyl group Composition.
[9] A composition for an adhesive further comprising a polyfunctional urethane (meth) acrylate compound,
The adhesive according to [8], wherein the content of the polyfunctional urethane (meth) acrylate monomer in the composition is 10 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. Composition.
[10] An adhesive composition comprising a polyfunctional (meth) acrylate,
[8] or [9], wherein the content of the polyfunctional (meth) acrylic monomer in the composition is 1 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. Composition for adhesives.

  Provided is a polarizing plate in which a stretched protective film and a polarizer are bonded with good adhesion.

The schematic diagram of the test method of a warm water resistance test is represented. FIG. 1 (A) represents a sample before warm water immersion, and FIG. 1 (B) represents a sample after warm water immersion.

The polarizing plate of the present invention is a polarizing plate in which a stretched protective film is provided on at least one surface of a polarizer via an adhesive layer.
The adhesive layer in the polarizing plate of the present invention is a cured product of a composition (hereinafter sometimes referred to as composition (1)),
The curable component of the composition (1) includes a composition containing more than 35% by mass of a (meth) acrylamide compound having no hydroxyl group and substantially not containing a (meth) acrylamide compound having a hydroxyl group. And
The curable component means a compound that undergoes a polymerization reaction by heat and active energy rays and cures.
In the present specification, “(meth) acrylate” means “at least one of acrylate and methacrylate”.
In the present specification, “(meth) acrylamide” means “at least one of acrylamide and methacrylamide”.
In the present specification, “(meth) acryloyl group” means “at least one of acryloyl group and methacryloyl group”.
In the present specification, “(meth) acryloyloxy group” means “at least one of acryloyloxy group and methacryloyloxy group”.

  An adhesive layer that is a cured product of the composition (1) (hereinafter sometimes referred to as an adhesive layer (1)) is in direct contact with the polarizer. There is no optical film having an optical function such as transmission, reflection or absorption of light between the adhesive layer and the polarizer.

<Adhesive layer (1)>
The adhesive layer (1) is obtained by curing the composition (1). As a method of curing the composition (1), a method of irradiating the composition (1) with active energy rays is preferable. Examples of active energy rays include ultraviolet rays, electron beams, and X-rays.

［式（１）中、Ｑ^１は、水素原子又はメチル基を表す。
Ｑ^２及びＱ^３は、それぞれ独立して、水素原子又は炭素数１〜６のアルキル基を表し、あるいはＱ^２とＱ^３とが互いに結合して、それらが結合する窒素原子とともに、環を形成してもよい。前記炭素数１〜６のアルキル基は、炭素数１〜６のアルコキシ基又は置換されていてもよいアミノ基を有していてもよい。］ The (meth) acrylamide compound not having a hydroxyl group means (meth) acrylamide which may further have a substituent other than a hydroxyl group on the N-position substituent.
As the (meth) acrylamide compound having no hydroxyl group, a compound represented by the formula (1) is preferable.

Wherein (1), ^{Q 1} represents a hydrogen atom or a methyl group.
Q ² and Q ³ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or Q ² and Q ³ are bonded to each other to form a ring together with the nitrogen atom to which they are bonded. May be. The alkyl group having 1 to 6 carbon atoms may have an alkoxy group having 1 to 6 carbon atoms or an optionally substituted amino group. ]

The alkyl group having 1 to 6 carbon atoms represented by Q ² and Q ³ may be any of linear, branched, and cyclic, for example, methyl group, ethyl group, propyl group, isopropyl group Butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, cyclopentyl group and cyclohexyl group.
Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group and hexyloxy group.
Examples of the optionally substituted amino group include an amino group; an amino group substituted with one alkyl group having 1 to 8 carbon atoms such as an N-methylamino group and an N-ethylamino group; N, N-dimethylamino And an amino group substituted with two alkyl groups having 1 to 8 carbon atoms such as an N, N-diethylamino group and an N, N-methylethylamino group.

The ring formed by Q ² and Q ³ bonded together and the nitrogen atom to which they are bonded is preferably a 5-membered ring or a 6-membered ring.
Ring, Q ² and Q ³ form together with the bond to the nitrogen atom to which they are attached to each other, in addition to the nitrogen atom, Q ² and Q ³ are attached as a ring constituent, nitrogen atom, oxygen atom or - C (= O)-may be included.
Examples of the ring formed by combining Q ² and Q ³ together with the nitrogen atom to which they are bonded include the rings described below.

Examples of (meth) acrylamide compounds having no hydroxyl group include N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, and N-tert-butyl. (Meth) acrylamide, N-hexyl (meth) acrylamide,
N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-ethyl-N-ethylmethyl (meth) acrylamide,
N- [2- (N, N-dimethylamino) ethyl] (meth) acrylamide, N- [2- (N, N-diethylamino) ethyl] (meth) acrylamide, N- [3- (N, N-dimethyl) Amino) propyl] (meth) acrylamide, N- [1-methyl-1- (N, N-dimethylamino) ethyl] (meth) acrylamide, N-acryloylpyrrolidine, 3-acryloyl-2-oxazolidinone, 4-acryloylmorpholine N-acryloylpiperidine, N-methacryloylpiperidine, N- (methoxymethyl) acrylamide,
N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide and N- (butoxymethyl) acrylamide, N- (1-methylethoxymethyl) acrylamide, N- (1-methylpropoxymethyl) acrylamide, N- (2 -Methylpropoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, N- (1,1-dimethylethoxymethyl) acrylamide, N- (2-methoxyethyl) acrylamide, N- (2-ethoxyethyl) acrylamide, N- (2-propoxyethyl) acrylamide, N- [2- (1-methylethoxy) ethyl] acrylamide, N- [2- (1-methylpropoxy) ethyl] acrylamide, N- [2- (2-methylpropoxy) ethyl Acrylamide, N- (2 Butoxyethyl) acrylamide and N- [2- (1,1-dimethylethoxy) ethyl] acrylamide.
From the viewpoint of adhesion to a polarizer or a stretched acrylic film, the (meth) acrylamide compound having no hydroxyl group is preferably N, N-dimethylacrylamide or N, N-diethyl (meth) acrylamide.

The content of the (meth) acrylamide compound having no hydroxyl group is more than 35% by mass, preferably more than 45% by mass, preferably 55 to 90%, based on the total amount of the curable component of the composition (1). It is mass%, More preferably, it is 60-85 mass%.
Two or more (meth) acrylamide compounds having no hydroxyl group may be contained.

The composition (1) may contain a compound other than the (meth) acrylamide compound having no hydroxyl group, for example, a polyfunctional urethane (meth) acrylate compound, a monofunctional (meth) acrylate monomer, a polyfunctional (meth) ) Acrylate monomers, polyfunctional (meth) acrylate oligomers and photopolymerization initiators.
The composition (1) preferably contains at least one selected from the group consisting of a polyfunctional urethane (meth) acrylate compound, a monofunctional (meth) acrylate monomer, a polyfunctional (meth) acrylate monomer, and a photopolymerization initiator. .

<Polyfunctional urethane (meth) acrylate compound>
The polyfunctional urethane (meth) acrylate compound refers to a compound having at least two (meth) acryloyloxy groups in the molecule and a urethane bond (—NHCOO—).
A polyfunctional urethane (meth) acrylate compound is obtained by reacting a hydroxyl group-containing (meth) acrylate monomer with a polyisocyanate. It can also be obtained by reacting a hydroxyl group-containing (meth) acrylate monomer with a terminal isocyanato group-containing urethane compound.
The hydroxyl group-containing (meth) acrylate monomer means a compound having at least one (meth) acryloyloxy group and at least one hydroxyl group in the molecule.
The terminal isocyanato group-containing urethane compound means a compound obtained by reacting a polyol and a polyisocyanate.

Examples of the hydroxyl group-containing (meth) acrylate monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, Examples include glycerin di (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol penta (meth) acrylate.
Polyisocyanates include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, triphenylmethane triisocyanate and dibenzylbenzene triisocyanate. And di- or tri-isocyanates; and multimers thereof.
Polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylol ethane, trimethylol propane, ditrimethylol propane, pentaerythritol, di Examples include pentaerythritol, dimethylol heptane, dimethylol propionic acid, dimethylol butanoic acid, glycerin, hydrogenated bisphenol A, and the like.

Commercially available polyfunctional urethane (meth) acrylate compounds include “AH-600”, “AT-600”, “UA-306H”, “UA-306T”, “UA-306I”, “UA-510H”, “UF-8001G”, “DAUA-167” (Kyoeisha Chemical Co., Ltd.);
“KUA-4I”, “KUA-6I”, “KUA-9N”, “KUA-10H”, “KUA-15N”, “KUA-C2I”, “KUA-PC2I”, “KUA-PEA2I”, “KUA -PEB2I ”,“ KUA-PEC2I ”(KSM Corporation);
“UV-6630B”, “UV-7510B”, “UV-7000B”, “UV-7461TE”, “UV-2000B”, “UV-2750B”, “UV-3000B”, “UV-3200B”, “UV-3500BA” , “UV-3520TL”, “UV-3210EA”, “UV-3310B”, “UV-3300B”, “UV-3700B”, “UV-6640B” (Nippon Synthetic Chemical Co., Ltd.);
“U-200PA”, “UA-160TM”, “UA-290TM”, “UA-4200”, “UA-4400” (Shin Nakamura Chemical Co., Ltd.);
“EBECRYL 204”, “EBECRYL 205”, “EBECRYL 210”, “EBECRYL 215”, “EBECRYL 220”, “EBECRYL 230”, “EBECRYL 244”, “EBECRYL 245”, “EBECRYL 264”, “EBECRYL 265”, “EBECRYL 270”, “EBECRYL 280 / 15IB”, “EBECRYL 284”, “EBECRYL 285”, “EBECRYL 294/25 HD”, “EBECRYL 1259”, “EBECRYL 1290”, “KRM 8200”, “KRM 8200AE”, “EBECRYL 4820”, “EBECRYL 4858”, “EBECRYL 5129”, “EBECRYL 8210”, “EBECRYL 8254”, “EBECRYL 8301R”, “EBECRYL 8307”, “EBECRYL 8402”, “EBECRYL 8405”, “EBECRYL 8411”, “EBECRYL 8465”, “EBECRYL 8800”, “EBECRYL 8804”, “EBECRYL 8807”, “EBECRYL 9260”, “EBECRYL 9270”, “KRM 7735”, “KRM 8296”, “KRM 8452”, “KRM 8904”, “EBECRYL 8311”, “EBECRYL 8701”, “KRM 8667”, “EBECRYL 9227EA”, “KRM 8528” (Daicel Ornex Co., Ltd.);
“UN-9200A”, “UN-7700”, “UN-7600”, “UN-6301”, “UN-6300”, “UN-5500” (Negami Kogyo Co., Ltd.) and the like.

The polyfunctional urethane (meth) acrylate compound is preferably a polyfunctional urethane (meth) acrylate compound having a molecular weight (Mw) of 10,000 or more, more preferably a polyfunctional urethane (meth) acrylate compound having a molecular weight of 15,000 or more, The polyfunctional urethane (meth) acrylate compound which is 20,000 or more is more preferable. If the molecular weight of the polyfunctional urethane (meth) acrylate compound is too small, the toughness of the adhesive layer will not be sufficient, and peeling will occur between the polarizer and the stretched protective film due to impact on the end of the polarizing plate during processing. Tend to occur.
The polyfunctional urethane (meth) acrylate compound is preferably a polyfunctional urethane (meth) acrylate compound having a molecular weight (Mw) of less than 100,000, more preferably a polyfunctional urethane (meth) acrylate compound having a molecular weight of less than 60,000, Polyfunctional urethane (meth) acrylate compounds that are less than 40,000 are more preferred. If the molecular weight of the polyfunctional urethane (meth) acrylate compound is too large, the viscosity of the composition (1) increases and the coating property deteriorates, or the elastic modulus of the adhesive layer (1) decreases and the durability of the polarizing plate. Is getting worse.

Content of a polyfunctional urethane (meth) acrylate compound is 10-45 mass parts normally with respect to 100 mass parts of (meth) acrylamide compounds which do not have a hydroxyl group, Preferably it is 15-40 mass parts, More preferably, it is 20-35 mass parts.
Two or more types of polyfunctional urethane (meth) acrylates may be included.

<Multifunctional (meth) acrylate monomer>
The polyfunctional (meth) acrylate monomer means a monomer having two or more (meth) acryloyloxy groups in the molecule, and a bifunctional (meth) acrylate monomer having two (meth) acryloyloxy groups in the molecule. : Trifunctional or higher polyfunctional (meth) acrylate monomer having 3 or more (meth) acryloyloxy groups in the molecule.

As a bifunctional (meth) acrylate monomer,
Ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol Alkylene glycol di (meth) acrylates such as di (meth) acrylate and neopentyl glycol di (meth) acrylate;
Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate and Polyoxyalkylene glycol di (meth) acrylates such as polytetramethylene glycol di (meth) acrylate;
Di (meth) acrylates of halogen-substituted alkylene glycols such as tetrafluoroethylene glycol di (meth) acrylate;
Di (meth) acrylates of aliphatic polyols such as trimethylolpropane di (meth) acrylate, ditrimethylolpropane di (meth) acrylate, pentaerythritol di (meth) acrylate;
Hydrogenated dicyclopentadienyl di (meth) acrylate, hydrogenated dicyclopentadiene such as tricyclodecane dimethanol di (meth) acrylate or di (meth) acrylate of tricyclodecane dialkanol;
Di (meth) acrylates of dioxane glycol or dioxane dialkanol, such as 1,3-dioxane-2,5-diyl di (meth) acrylate [also known as dioxane glycol di (meth) acrylate];
Di (meth) acrylates of bisphenol A or bisphenol F alkylene oxide adducts such as bisphenol A ethylene oxide adduct diacrylate and bisphenol F ethylene oxide adduct diacrylate;
Epoxy di (meth) acrylates of bisphenol A or bisphenol F such as acrylic acid adducts of bisphenol A diglycidyl ether and acrylic acid adducts of bisphenol F diglycidyl ether; silicone di (meth) acrylates;
Di (meth) acrylate of hydroxypivalic acid neopentyl glycol ester;
2,2-bis [4- (meth) acryloyloxyethoxyethoxyphenyl] propane; 2,2-bis [4- (meth) acryloyloxyethoxyethoxycyclohexyl] propane;
Di (meth) acrylate of 2- (2-hydroxy-1,1-dimethylethyl) -5-ethyl-5-hydroxymethyl-1,3-dioxane];
Tris (hydroxyethyl) isocyanurate di (meth) acrylate; and the like.

  The trifunctional or higher polyfunctional (meth) acrylate monomers include glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol. Trivalent or higher aliphatic polyols such as tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Poly (meth) acrylate is mentioned.

As the polyfunctional (meth) acrylate monomer, a poly (meth) acrylate of a trivalent or higher halogen-substituted polyol;
Tri (meth) acrylates of glycerin alkylene oxide adducts;
Tri (meth) acrylate of an alkylene oxide adduct of trimethylolpropane;
1,1,1-tris [2- {2- (meth) acryloyloxyethoxy} ethoxy] propane;
Examples also include 1,3,5-tris [2- (meth) acryloyloxyethyl] isocyanurate.

The polyfunctional (meth) acrylate monomer is preferably dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, or pentaerythritol triacrylate.
The content of the polyfunctional (meth) acrylate monomer is usually 1 to 45 parts by mass, preferably 2 to 30 parts by mass, more preferably 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. Is 3 to 19 parts by mass, more preferably 4 to 17 parts by mass.
Two or more polyfunctional (meth) acrylate monomers may be included.

<Monofunctional (meth) acrylate monomer>
The monofunctional (meth) acrylate monomer means a monomer having one (meth) acryloyloxy group in the molecule.
The monofunctional (meth) acrylate monomer is preferably a (meth) acrylate having an alicyclic structure or an ether bond in the molecule, and is a (meth) acrylate having an alicyclic structure or a cyclic ether structure in the molecule. It is more preferable.
Carbon number of an alicyclic structure is 3-12 normally, Preferably it is 5-12.
Carbon number of a cyclic ether structure is 3-12 normally, Preferably it is 5-8.

［式中、Ｒ^１は水素原子又はメチル基を表す。
Ｒ^２は、置換基を有していてもよい炭素数７〜１２の芳香族炭化水素基又は置換基を有していてもよい炭素数１〜１２の脂肪族炭化水素基を表し、該炭素数１〜１２の脂肪族炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｃ（＝Ｏ）−に置き換わっていてもよい。］ Examples of the monofunctional (meth) acrylate monomer include a compound represented by the formula (II).

[Wherein, R ¹ represents a hydrogen atom or a methyl group.
R ² represents an optionally substituted aromatic hydrocarbon group having 7 to 12 carbon atoms or an optionally substituted aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the carbon —CH ₂ — contained in the aliphatic hydrocarbon group of formula 1 to 12 may be replaced by —O— or —C (═O) —. ]

Examples of the aromatic hydrocarbon group having 7 to 12 carbon atoms represented by R ² include a phenyl group, a naphthyl group, and a tolyl group.

Examples of the aliphatic hydrocarbon group having 1 to 12 carbon atoms represented by R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n A linear or branched alkyl group having 1 to 12 carbon atoms such as a pentyl group, an n-hexyl group, a 2-methylhexyl group, a 2-ethylhexyl group, an isononyl group;
And monocyclic or polycyclic alicyclic hydrocarbon groups having 3 to 12 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, adamantyl group, dicyclopentanyl, dicyclopentenyl, and isobornyl. A linear or branched alkyl group having 1 to 6 carbon atoms or a polycyclic alicyclic hydrocarbon group having 5 to 12 carbon atoms is preferable.

Examples of the group in which at least one —CH ₂ — contained in the aliphatic hydrocarbon group having 1 to 12 carbon atoms is replaced by —O— or —CO— include the groups described below. In the following formula, * represents a bond with an oxygen atom.

Examples of the substituent that the aliphatic hydrocarbon group having 1 to 12 carbon atoms and the aromatic hydrocarbon group having 7 to 12 carbon atoms represented by R ² may have include a hydroxyl group and an alkoxy having 1 to 6 carbon atoms. Group, an aryloxy group having 6 to 12 carbon atoms and an optionally substituted amino group, and a hydroxyl group is preferable.
Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group and hexyloxy group.
Examples of the aryloxy group having 6 to 12 carbon atoms include a phenoxy group, a methylphenoxy group, and a naphthyloxy group.
Examples of the optionally substituted amino group include an amino group; an amino group substituted with one alkyl group having 1 to 8 carbon atoms such as an N-methylamino group and an N-ethylamino group; N, N-dimethylamino And an amino group substituted with two alkyl groups having 1 to 8 carbon atoms such as an N, N-diethylamino group and an N, N-methylethylamino group.

  Monofunctional (meth) acrylate monomers include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate, isononyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate 2-hydroxy-3-phenoxypropyl (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, ethyl carbitol (meth) acrylate 2-phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, 2- (N, N-dimethylamino) ethyl (meth) acrylate, 2-carboxyethyl (meth) acrylate, 1- [2- ( (Meth) acryloyloxyethyl] phthalic acid, 1- [2- (meth) acryloyloxyethyl] hexahydrophthalic acid, 1- [2- (meth) acryloyloxyethyl] succinic acid and 4- [2- (meth) acryloyl Oxyethyl] trimellit, tetrahydrofurfuryl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate acid and the like, and dicyclopentanyl acrylate is preferred.

As content of a monofunctional (meth) acrylate monomer, it is 1-40 mass% normally with respect to the sclerosing | hardenable component whole quantity of a composition (1), Preferably it is 3-35 mass%, More preferably, it is 5 ˜20 mass%.
When the monofunctional (meth) acrylate monomer contains (meth) acrylate having an alicyclic structure in the molecule, the content of (meth) acrylate having an alicyclic structure in the molecule is the composition (1). Preferably it is 3-40 mass%, More preferably, it is 5-25 mass% with respect to the curable component whole quantity.
The monofunctional (meth) acrylate monomer may contain 2 or more types.

<Multifunctional (meth) acrylate oligomer>
A polyfunctional (meth) acrylate oligomer is obtained by reacting two or more compounds having a functional group, and is a (meth) acrylate oligomer (urethane (meth) acrylate) having at least two (meth) acryloyloxy groups in the molecule. Means). Examples of (meth) acrylate oligomers include polyester (meth) acrylate oligomers and epoxy (meth) acrylate oligomers. (

The polyester (meth) acrylate oligomer means an oligomer having an ester bond and at least two (meth) acryloyloxy groups in the molecule.
The polyester (meth) acrylate oligomer can be obtained, for example, by subjecting (meth) acrylic acid, a polybasic carboxylic acid or an anhydride thereof, and a polyol to a dehydration condensation reaction.
Polybasic carboxylic acids or anhydrides thereof include succinic anhydride, adipic acid, maleic anhydride, itaconic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, phthalic acid, succinic acid, maleic acid , Itaconic acid, trimellitic acid, pyromellitic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid and the like.
Polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylol ethane, trimethylol propane, ditrimethylol propane, pentaerythritol, di Examples include pentaerythritol, dimethylol heptane, dimethylol propionic acid, dimethylol butanoic acid, glycerin, hydrogenated bisphenol A, and the like.

The epoxy (meth) acrylate oligomer can be obtained by an addition reaction between polyglycidyl ether and (meth) acrylic acid. The epoxy (meth) acrylate oligomer has at least two (meth) acryloyloxy groups in the molecule.
Examples of the polyglycidyl ether include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and bisphenol A diglycidyl ether.

<Photopolymerization initiator>
The composition (1) preferably contains a photopolymerization initiator, and the photopolymerization initiator is preferably a radical photopolymerization initiator.
The radical photopolymerization initiator is not particularly limited as long as it can initiate the polymerization of the radical polymerizable compound by irradiation with active energy rays, and a conventionally known one can be used. Specific examples of the radical photopolymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-methyl-1 Acetophenone based initiators such as [4- (methylthio) phenyl-2-morpholinopropan-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzophenone, 4-chlorobenzophenone and 4 Benzophenone initiators such as 4,4'-diaminobenzophenone; benzoin ether initiators such as benzoin propyl ether and benzoin ethyl ether; thioxanthone initiators such as 4-isopropylthioxanthone; others, xanthone, fluorenone, camphor Down, benzaldehyde, there is such as anthraquinone.

  Content of radical photopolymerization initiator is 0.5-20 mass parts normally with respect to 100 mass parts of sclerosing | hardenable components, Preferably it is 1-6 mass parts. When the amount of the radical photopolymerization initiator is small, curing is insufficient and mechanical strength and adhesiveness tend to be lowered. On the other hand, when there is too much quantity of radical photopolymerization initiator, the quantity of the sclerosing | hardenable component of a composition (1) will become relatively small, and the durable performance of the polarizing plate obtained may fall.

  The composition (1) further comprises a photosensitizer, an antistatic agent, an antioxidant, an ultraviolet absorber, a leveling agent, a solvent, a polyol, an ion trap agent, a chain transfer agent, a sensitization aid, a light stabilizer, You may contain a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, an antifoamer, a silane coupling agent, a pigment | dye, a thermal polymerization initiator, etc.

As the solvent, aliphatic hydrocarbon solvents such as n-hexane and cyclohexane;
Aromatic hydrocarbon solvents such as toluene and xylene;
Alcohol solvents such as methanol, ethanol, propanol, isopropanol and butanol;
Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone;
Ester solvents such as methyl acetate, ethyl acetate and butyl acetate;
Cellosolve solvents such as methyl cellosolve, ethyl cellosolve and butyl cellosolve;
Halogenated hydrocarbon solvents such as methylene chloride and chloroform; and the like.
The content of the solvent is appropriately determined from the viewpoint of viscosity adjustment according to processing purposes such as film formability and the optimum viscosity range in the coating method to be employed.

  The thickness of the adhesive layer (1) is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. When the thickness of the adhesive layer (1) exceeds 10 μm, the effect of thinning becomes small. The thickness of the adhesive layer (1) is preferably 0.1 μm or more from the viewpoint of adhesiveness.

  The storage elastic modulus at 80 ° C. of the adhesive layer (1) is preferably 500 MPa to 10,000 MPa. The storage elastic modulus at 80 ° C. of the adhesive layer (1) is more preferably 650 MPa to 8,000 MPa, and further preferably 800 MPa to 6,000 MPa. When the storage elastic modulus at 80 ° C. of the adhesive layer (1) is too low, it is likely that cracking of the polarizer cannot be suppressed during a thermal shock test in which heating and cooling are repeated. On the other hand, if the storage elastic modulus at 80 ° C. of the adhesive layer is too high, the adhesive layer (1) becomes brittle, and there is a tendency that problems such as chipping of the adhesive layer occur during processing of the polarizing plate. The storage elastic modulus at 80 ° C. can be measured by a dynamic viscoelasticity measuring apparatus.

  The viscosity of the composition (1) is preferably lower from the viewpoint of coatability. Specifically, the viscosity at 25 ° C. is preferably 2 to 500 mPa · s, and more preferably 5 to 100 mPa · s.

<Stretched protective film>
Examples of the protective film include cellulose acetate resin, polyolefin resin, (meth) acrylic resin, polyimide resin, polycarbonate resin, polyester resin, and the like, and acrylic resin or cycloolefin resin is preferable, and acrylic resin is more preferable.

The cycloolefin resin means a resin containing a structural unit derived from a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene-based monomer, and the cycloolefin resin is a thermoplastic resin.
Examples of the cycloolefin resin include a ring-opened polymer of cycloolefin and a hydrogenated product of a ring-opened copolymer using two or more kinds of cycloolefin. Further, it may be an addition polymer such as a cycloolefin and an aromatic compound having a polymerizable double bond such as a chain olefin and / or a vinyl group. The cycloolefin resin may have a polar group.
Examples of chain olefins include ethylene and propylene.
Examples of the aromatic compound having a polymerizable double bond such as a vinyl group include styrene, α-methylstyrene, and nuclear alkyl-substituted styrene.

50 mol% or less may be sufficient as content of the structural unit derived from a cycloolefin, Preferably it is 15-50 mol%.
In the case of a copolymer comprising a cycloolefin, a chain olefin and an aromatic compound having a vinyl group, the content of the structural unit derived from the chain olefin is usually 5 to 80 mol%, and the aromatic compound having a vinyl group The content of the monomer unit is usually 5 to 80 mol%.

  As the cycloolefin resin, an appropriate commercial product can be used. For example, “TOPAS” produced by TOPAS ADVANCED POLYMERS GmbH in Germany, sold in Japan from Polyplastics, “Arton” sold from JSR, and sold by Nippon Zeon. “ZEONOR” and “ZEONEX”, and “Apel” (all are trade names) sold by Mitsui Chemicals.

The (meth) acrylic resin is a polymer containing a structural unit derived from a (meth) acrylic monomer, and examples of the (meth) acrylic monomer include methacrylic acid esters and acrylic acid esters.
Methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and C1-C8 methacrylic acid alkylesters, such as 2-hydroxyethyl methacrylate, are mentioned, Preferably it is a C1-C4 methacrylic acid alkylester. The methacrylic acid ester may contain 2 or more types.
Examples of acrylate esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and C1-C8 acrylic acid alkyl ester, such as 2-hydroxyethyl acrylate, is mentioned, Preferably it is C1-C4 acrylic acid alkyl ester, The acrylic acid ester may contain 2 or more types. .

The (meth) acrylic resin may be a polymer composed only of structural units derived from (meth) acrylic monomers, or may contain other structural units.
Other structural units include a structural unit derived from a monofunctional monomer having one polymerizable carbon-carbon double bond in the child, and a multi-component having at least two polymerizable carbon-carbon double bonds in the molecule. Examples include structural units derived from functional monomers.

Monofunctional monomers include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, halogenated styrene and hydroxystyrene; vinyl cyanides such as acrylonitrile and methacrylonitrile; acrylic acid, methacrylic acid, maleic anhydride, Unsaturated acids such as itaconic anhydride; maleimides such as N-methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide; allyl alcohols such as methallyl alcohol and allyl alcohol; vinyl acetate; vinyl chloride; ethylene; Methyl-1-pentene; 2-hydroxymethyl-1-butene; methyl vinyl ketone; N-vinyl pyrrolidone; N-vinyl carbazole;
Polyfunctional monomers include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate; unsaturated compounds such as allyl acrylate, allyl methacrylate, and allyl cinnamate Alkenyl esters of carboxylic acids; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate; aromatic polyalkenyl compounds such as divinylbenzene;

  The (meth) acrylic resin preferably contains 50% by mass or more of a structural unit derived from a (meth) acrylic monomer, the structural unit derived from an alkyl methacrylate ester is 50 to 100% by mass, and the structural unit derived from an alkyl acrylate ester is included. It is more preferable that 0-50 mass% and other structural units are 0-50 mass%, the structural unit derived from methacrylic acid alkyl ester is 50-99.9 mass%, and the structural unit derived from acrylic acid alkyl ester is 0.00. It is more preferable that 1-50 mass% and other structural units are 0-49.9 mass%.

Since the (meth) acrylic resin can improve the durability of the film, it may have a ring structure in the main chain.
The ring structure is preferably a cyclic acid anhydride structure such as a glutaric anhydride structure and a succinic anhydride structure; a cyclic imide structure such as a glutarimide structure and a succinimide structure; a lactone ring structure such as butyrolactone and valerolactone.
As the content of the ring structure in the main chain is increased, the glass transition temperature of the (meth) acrylic resin can be increased.
The (meth) acrylic resin having a cyclic acid anhydride structure or cyclic imide structure in the main chain is a method of copolymerizing a monomer having a cyclic structure such as maleic anhydride or maleimide with a (meth) acrylic monomer, (meth) acrylic It can be obtained by a method of dehydration / demethanol condensation reaction after polymerization of a monomer, a method of reacting a (meth) acryl monomer and an amino compound, or the like.
A (meth) acrylic resin having a lactone ring structure in the main chain is prepared by preparing a polymer having a hydroxyl group and an ester group in the main chain, and if necessary, in the presence of a catalyst such as an organic phosphorus compound. It can be obtained by a method of cyclizing condensation of the compound.

  Examples of the polymer having a hydroxyl group and an ester group in the main chain include methyl 2- (hydroxymethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, isopropyl 2- (hydroxymethyl) acrylate, 2- ( It can be obtained by polymerizing a (meth) acrylic acid ester having a hydroxyl group and an ester group, such as hydroxymethyl) n-butyl acrylate and t-butyl 2- (hydroxymethyl) acrylate. A more specific method for preparing a polymer having a lactone ring structure is described in, for example, JP-A-2007-254726.

  The (meth) acrylic resin can be obtained by radical polymerization of the monomers described above. In radical polymerization, a solvent or a polymerization initiator may be used as necessary.

[Other resins]
The (meth) acrylic resin may contain other resins.
Examples of other resins include olefin resins such as polyethylene, polypropylene, ethylene-propylene copolymer and poly (4-methyl-1-pentene); halogen-containing resins such as vinyl chloride and chlorinated vinyl resins; polystyrene, styrene -Styrene resin such as methyl methacrylate copolymer and styrene-acrylonitrile copolymer; Polyester resin such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; Polyarylate composed of aromatic diol and aromatic dicarboxylic acid; Polylactic acid And biodegradable polyesters such as polybutylene succinate; polycarbonates; polyamides such as nylon 6, nylon 66 and nylon 610; polyacetals; polyphenylene oxides; Polyether ether ketone; polyether nitrile; polysulfone; polyether sulfone; polyoxyethylene Penji alkylene; polyamideimide, and the like.
The content of other resins is preferably 0 to 50% by mass, more preferably 0 to 25% by mass, and still more preferably 0 to 10% by mass.

  The (meth) acrylic resin may contain rubber particles in terms of the impact resistance and film forming property of the film. Rubber particles are rubber elastic particles including a layer exhibiting rubber elasticity. The rubber particle may be a particle composed only of a layer exhibiting rubber elasticity, or may be a particle having a multilayer structure having another layer together with a layer exhibiting rubber elasticity. Examples of rubber elastic bodies include olefin elastic polymers, diene elastic polymers, styrene-diene elastic copolymers, acrylic elastic polymers, and the like. Among these, an acrylic elastic polymer is preferably used from the viewpoint of light resistance and transparency.

  The stretched protective film may contain, for example, an ultraviolet absorber, a lubricant, a dispersant, an organic dye, a pigment, an inorganic dye, an antioxidant, an antistatic agent, a surfactant, and the like.

The stretched protective film may be either a uniaxially stretched protective film or a biaxially stretched protective film. Biaxial stretching may be simultaneous biaxial stretching in which stretching is performed simultaneously in two stretching directions, or sequential biaxial stretching in which stretching is performed in a predetermined direction and then stretching in another direction.
The stretched protective film may have an optical function such as a retardation film.

  The thickness of the stretched protective film is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less.

  A surface treatment such as an antiglare treatment, a hard coat treatment, an antistatic treatment, or an antireflection treatment may be applied to the surface of the stretched protective film opposite to the surface attached to the polarizing film.

<Polarizer>
Specifically, the polarizer has a dichroic dye adsorbed and oriented on a polyvinyl alcohol resin film. By performing uniaxial stretching either before, during or after adsorption of the dichroic dye, the dichroic dye in the polyvinyl alcohol-based resin film can be oriented in the stretching direction. A polyvinyl alcohol resin is obtained by saponifying a polyvinyl acetate resin. As polyvinyl acetate resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymer, etc. Is mentioned. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins including ethylene, vinyl ethers, and acrylamides having an ammonium group.

  The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, for example, polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like may be used. The degree of polymerization of the polyvinyl alcohol resin is usually in the range of 1,000 to 10,000, preferably in the range of 1,500 to 5,000.

  A film made of such a polyvinyl alcohol resin is used as an original film of a polarizer. The method for forming the polyvinyl alcohol resin is not particularly limited, and can be formed by a conventionally known appropriate method. Although the film thickness of the raw film which consists of polyvinyl alcohol resin is not specifically limited, For example, it is about 10-150 micrometers.

  A polarizer usually has a process of dyeing a polyvinyl alcohol resin film with a dichroic dye and adsorbing the dichroic dye (dyeing process), and a polyvinyl alcohol resin film having the dichroic dye adsorbed on the substrate. It is manufactured through a step of treating with an acid aqueous solution (boric acid treatment step) and a step of washing with water after the treatment with the boric acid aqueous solution (water washing treatment step).

  Although uniaxial stretching is also performed, the uniaxial stretching of the polyvinyl alcohol resin film may be performed before the dyeing process, may be performed during the dyeing process, or may be performed after the dyeing process. Good. When uniaxial stretching is performed after the dyeing treatment step, this uniaxial stretching may be performed before the boric acid treatment step or during the boric acid treatment step. Of course, it is also possible to perform uniaxial stretching in these plural stages. Uniaxial stretching may be performed by a method of passing a film between spaced rolls having different peripheral speeds, or by a method of sandwiching the film with a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen with the solvent may be sufficient. The draw ratio is usually about 3 to 8 times.

  The dyeing process is performed, for example, by immersing the polyvinyl alcohol resin film in an aqueous solution containing a dichroic dye. Specifically, iodine or a dichroic organic dye is used as the dichroic dye. The dichroic organic dyes include dichroic direct dyes composed of disazo compounds such as C.I. DIRECT RED 39, and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.

  When iodine is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually 0.5 to 20 parts by weight per 100 parts by weight of water. . When iodine is used as the dichroic dye, the temperature of the aqueous solution used for dyeing is usually 20 to 40 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 20 to 1,800 seconds. is there.

On the other hand, when a dichroic organic dye is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol resin film in an aqueous solution containing a water-soluble dichroic organic dye is usually employed. The content of the dichroic organic dye in this aqueous solution is usually 1 × 10 ⁻⁴ to 10 parts by mass, preferably 1 × 10 ⁻³ to 1 part by mass, more preferably 1 × 10 ⁻³ per 100 parts by mass of water. ˜1 × 10 ⁻² parts by mass. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. When a dichroic organic dye is used as the dichroic dye, the temperature of the aqueous dye solution used for dyeing is usually 20 to 80 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 10 to 10 ° C. 1,800 seconds.

  The boric acid treatment step is performed by immersing a polyvinyl alcohol-based resin film dyed with a dichroic dye in an aqueous boric acid solution. The boric acid content in the boric acid aqueous solution is usually 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the dichroic dye in the dyeing process described above, the boric acid aqueous solution used in this process preferably contains potassium iodide. In this case, the content of potassium iodide in the boric acid aqueous solution is usually 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the boric acid aqueous solution is usually 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C.

  In the water washing treatment step, the polyvinyl alcohol resin film after the boric acid treatment described above is washed with water, for example, by immersing it in water. The water temperature in the water washing treatment is usually 5 to 40 ° C., and the immersion time is usually 1 to 120 seconds. After the water washing treatment, usually a drying treatment is performed to obtain a polarizing film. The drying process can be performed using, for example, a hot air dryer or a far infrared heater. The temperature of a drying process is 30-100 degreeC normally, Preferably it is 50-80 degreeC. The time for the drying treatment is usually 60 to 600 seconds, preferably 120 to 600 seconds.

  As described above, it is possible to produce a polarizing film in which a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol resin film. The thickness of the polarizing film can be about 5 to 40 μm.

  The stretched protective film may be subjected to a surface treatment such as an antiglare treatment, a hard coat treatment, an antistatic treatment, or an antireflection treatment on the surface opposite to the surface attached to the polarizer.

  In order to improve the adhesion between the polarizer and the stretched protective film, either one or both of the polarizer and the stretched protective film are subjected to a laser treatment, a corona treatment, an ultraviolet irradiation treatment, a frame (flame). Surface treatment for improving adhesiveness such as treatment, saponification treatment, and primer treatment may be appropriately performed.

<Adhesion between polarizer and stretched protective film>
As a method for adhering the polarizer and the stretched protective film, the composition (1) is applied to one or both of the polarizer and the stretched protective film, and the other is applied to the other. The method of laminating | stacking a sticking surface and irradiating an active energy ray and hardening a composition (1) is mentioned.
For the coating of the composition (1), various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.

The light source used for curing the composition (1) is not particularly limited, and generates ultraviolet rays, electron beams , X-rays, etc., preferably ultraviolet rays. As the ultraviolet light source, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, or a metal halide lamp can be used. . The light irradiation intensity during the curing of the composition (1) varies depending on the composition, but the irradiation intensity in the wavelength region effective for activating the polymerization initiator is preferably 10 to 2500 mW / cm ^2. . If the light irradiation intensity at the time of curing of the composition (1) is too small, the time required for the reaction to sufficiently proceed becomes long. Conversely, if it is too large, the heat radiated from the lamp and the composition ( The heat generated during the polymerization in 1) may cause yellowing of the adhesive or deterioration of the attached film. The light irradiation time at the time of curing the composition (1) is also controlled for each composition and is not particularly limited, but the integrated light amount expressed as the product of the irradiation intensity and the irradiation time is 10 to 2, It is preferable to set it to be 500 mJ / cm ² . When the integrated light quantity to the composition (1) is too small, the generation of active species derived from the polymerization initiator is not sufficient, and the resulting adhesive layer may be insufficiently cured. On the other hand, if the integrated light quantity is too large, the irradiation time becomes very long, which is disadvantageous for improving productivity.

  The polarizing plate of the present invention is a polarizing plate in which a stretched protective film is provided on at least one surface of the polarizer via the adhesive layer (1), but the other surface of the polarizer is A stretched protective film may be provided via an adhesive layer (hereinafter sometimes referred to as an adhesive layer (2)) or a pressure-sensitive adhesive layer, or an unstretched protective film is provided. Alternatively, an optical film having an optical function may be provided. The optical film means a film having an optical function such as transmission, reflection, and absorption of light.

The adhesive layer (2) may be a cured product of the composition (1) or a cured product other than the composition (1). In the case of a cured product other than the composition (1), a cured product of a known composition used as an adhesive may be mentioned. For example, an adhesive component such as a polyvinyl alcohol resin or a urethane resin is dissolved in water or Examples thereof include a dispersed aqueous adhesive composition and a cured product of an acrylic adhesive composition mainly composed of a (meth) acrylic compound.
As an adhesive layer, the hardened | cured material of the composition which uses an acrylic polymer, a silicone type polymer, polyester, a polyurethane, polyether etc. as a base polymer is mentioned. Among them, like acrylic pressure-sensitive adhesives, it is excellent in transparency, retains appropriate wettability and cohesion, is excellent in adhesion to adherends such as polarizing plates and liquid layer cells, and has weather resistance and It is preferable to select and use one that has heat resistance and the like and does not cause peeling problems such as floating and peeling under the conditions of heating and humidification.
Acrylic adhesives include alkyl esters of (meth) acrylic acid having an alkyl group with 20 or less carbon atoms such as methyl, ethyl and butyl groups, and (meth) acrylic acid and hydroxyethyl (meth) acrylate. Based on an acrylic copolymer having a weight average molecular weight of 100,000 or more, which is blended with a functional group-containing acrylic monomer comprising a glass transition temperature of preferably 25 ° C. or less, more preferably 0 ° C. or less. Useful as a polymer.

  The pressure-sensitive adhesive layer is formed on the polarizing plate by, for example, dissolving or dispersing the pressure-sensitive adhesive composition in an organic solvent such as toluene or ethyl acetate to prepare a 10 to 40% by weight solution, which is the target surface of the polarizing plate. It is possible to carry out by a method of forming a pressure-sensitive adhesive layer directly by coating, a method of previously forming a pressure-sensitive adhesive layer on a protective film and transferring it to the target surface of a polarizing plate, etc. it can. The thickness of the pressure-sensitive adhesive layer is determined according to the adhesive force and the like, but a range of about 1 to 50 μm is appropriate.

  The pressure-sensitive adhesive layer contains glass fiber, glass beads, resin beads, fillers made of metal powder or other inorganic powders, pigments, colorants, antioxidants, ultraviolet absorbers, antistatic agents, etc. as necessary. You may go out. Examples of ultraviolet absorbers include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, and nickel complex compounds.

Examples of the antistatic agent include ionic compounds, conductive fine particles, and conductive polymers, and ionic compounds are preferably used. The cation component constituting the ionic compound is not particularly limited, and may be an inorganic anion or an organic anion. Examples of the structure of the organic cation include a pyridinium cation, an imidazolium cation, an ammonium cation, a sulfonium cation, and a phosphonium cation. Examples of the structure of the inorganic cation include a potassium ion and a lithium ion. On the other hand, the anion component constituting the ionic compound is not particularly limited and may be an inorganic anion or an organic anion, but an anionic component containing a fluorine atom is preferable because it gives an ionic compound having excellent antistatic performance. . As an anion component containing a fluorine atom, hexafluorophosphate anion [(PF ₆ ⁻ )], bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ] anion, bis (fluorosulfonyl) imide anion [ (FSO ₂ ) ₂ N ⁻ ] anion and the like.

The polarizing plate of this invention can be used for a liquid crystal panel and a liquid crystal display device.
The polarizing plate of the present invention can be disposed on one side or both sides of a liquid crystal cell. An adhesive layer can be used for attaching the polarizing plate and the liquid crystal cell.
The liquid crystal cell may be any type. For example, various liquid crystal cells such as an active matrix drive type liquid crystal cell represented by a thin film transistor type and a simple matrix drive type liquid crystal cell represented by a super twisted nematic type are used. Thus, a liquid crystal display device can be formed. The polarizing plates provided on both surfaces of the liquid crystal cell may be the same or different.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited by these examples. In the examples, “%” and “part” representing the content or amount used are based on mass unless otherwise specified.

(Production Example 1) Production of stretched protective film Pellet-shaped resin A and pellet-shaped resin B were charged into an extruder at a weight ratio of 75:25 to obtain a (meth) acrylic resin composition. . The obtained composition was melt-kneaded by heating to obtain a liquid melt-kneaded product. The obtained melt-kneaded product is solidified using a cooling roll while continuously extruding it from a T-die into a film shape, so that a long (meth) acrylic resin film (hereinafter referred to as a protective film) having a thickness of 120 μm is sometimes used. There was.

[A] Methyl methacrylate resin “ALTUGLAS HT121” manufactured by ARKEMA (glass transition temperature T _gA : 124 ° C., weight average molecular weight M _wA : 78200, number average molecular weight M _nA : 41200 , molecular weight distribution _{M wA / M nA: 1.9)} ,
[B] Methyl methacrylate resin (glass transition temperature T _gB : 110 ° C., weight average molecular weight M _wB : 162000, number average molecular weight M _nB : 84500, molecular weight dispersion M _wB / M _nB : 1.9)

  The obtained protective film was subjected to a longitudinal stretching process, and then subjected to a lateral stretching process (sequential biaxial stretching process) to obtain a stretched protective film having a thickness of 40 μm. The stretching temperature is the glass transition temperature of the protective film + 10 ° C. for both the longitudinal stretching and the lateral stretching, and the stretching ratios of the longitudinal stretching and the lateral stretching are 2.2 times and 2.0 times that of the protective film, respectively. .

(Manufacture examples 2-19) Preparation of adhesive composition Each of the component shown below was mixed in the mass part shown in Table 1, and the adhesive composition was prepared.

In addition, the thing of Table 1 is shown below.
DMAA: N, N-dimethylacrylamide, obtained from KJ Chemicals Corporation FA-513AS: dicyclopentanyl acrylate, obtained from Hitachi Chemical Co., Ltd. Biscoat # 150 (trade name): Tetrahydrofurfuryl acrylate, Osaka Organic Industries Obtained from Co., Ltd. 4HBA: 4-hydroxybutyl acrylate, obtained from Osaka Organic Industry Co., Ltd., solubility of methacrylic resin layer 27%,
CHDMMA: 1,4-cyclohexanedimethanol monoacrylate, obtained from Nippon Kasei Co., Ltd. A-DPH: dipentaerythritol hexaacrylate, obtained from Shin-Nakamura Chemical Co., Ltd. A-TMPT: trimethylolpropane triacrylate, Shin-Nakamura Obtained from Chemical Industry Co., Ltd. A-TMM-3: Pentaerythritol triacrylate (Triester 37%), obtained from Shin-Nakamura Chemical Co., Ltd.
UV-3000B: UV curable urethane acrylate resin, obtained from Nippon Synthetic Chemical Industry Co., Ltd. Viscosity: 45,000-65,000 mPa · s / 60 ° C., molecular weight (Mw): 18,000, number of oligomer functional groups: 2, glass transition temperature Tg: −39 ° C.
UV-3700B: UV curable urethane acrylate resin, obtained from Nippon Synthetic Chemical Industry Co., Ltd. Viscosity: 30,000 to 60,000 mPa · s / 60 ° C., molecular weight (Mw): 38,000, number of oligomer functional groups: 2, glass transition temperature Tg: −6 ° C.
DAROCUR 1173: 2-hydroxy-2-methyl-1-phenyl-propan-1-one, obtained from BASF Japan Ltd.

(Measurement of viscosity of adhesive composition at 25 ° C.)
About each adhesive composition prepared in Production Examples 2 to 19, the viscosity at a temperature of 25 ° C. was measured using an E-type viscometer “TVE-25L” manufactured by Toki Sangyo Co., Ltd. The results are shown in Table 2.

(Measurement of storage elastic modulus at 80 ° C. of cured product of adhesive composition)
After curing each adhesive composition prepared in Production Examples 2 to 19 on one side of a 50 μm-thick film made of norbornene-based resin using a coating machine [Bar Coater, manufactured by Daiichi Rika Co., Ltd.] The film was coated so that the film thickness was about 30 μm. Next, the adhesive composition was cured by irradiating ultraviolet rays with a “D bulb” manufactured by Fusion UV Systems Co., Ltd. so that the integrated light amount was 3,000 mJ / cm ² . This was cut into a size of 5 mm × 30 mm, and the cycloolefin-based resin film was peeled off to obtain a cured film of the adhesive composition. The obtained cured film was gripped with a gripping tool spacing of 2 cm using a dynamic viscoelasticity measuring device “DVA-220” manufactured by IT Measurement Control Co., Ltd. so that its long side is in the tension direction. And the shrinkage frequency was set to 10 Hz, the rate of temperature increase was set to 3 ° C./min, and the storage elastic modulus at a temperature of 80 ° C. was obtained. The results are shown in Table 2. A higher storage elastic modulus at a temperature of 80 ° C. is better. When the value of the storage elastic modulus at a temperature of 80 ° C. is low, cracking of the polarizer tends not to be suppressed during the thermal shock test.

(Examples 1-14 and Comparative Examples 1-4) Production of Polarizing Plate The surface of the stretched protective film produced in Production Example 1 was subjected to corona discharge treatment, and the corona discharge treatment surface was subjected to Production Examples 2-19. The adjusted adhesive composition was applied with a bar coater so that the film thickness after curing was about 2.5 μm. A 25 μm polyvinyl alcohol (PVA) -iodine polarizer was bonded to the coated surface. Next, a corona discharge treatment is applied to the surface of a 50 μm-thick retardation film made of norbornene resin (trade name “ZEONOR”, manufactured by Nippon Zeon Co., Ltd.), and the adhesive composition is cured on the corona discharge treatment surface. The film was coated with a bar coater so that the subsequent film thickness was about 2.5 μm. On the coated surface, a polarizer bonded with a protective film stretched on one side was bonded on the polarizer side to prepare a laminate. From the side of the stretched protective film produced in Production Example 1 of this laminate, an integrated light amount of 250 mJ / cm ² (using a “D bulb” manufactured by Fusion UV Systems, Inc.) with a belt conveyor is used. UVB was irradiated to cure the adhesive composition, and a polarizing plate was produced.
Polarizing plates obtained by curing the adhesive compositions prepared in Production Examples 2 to 15 were obtained as Examples 1 to 14, and obtained by curing the adhesive compositions prepared in Production Examples 16 to 19. The polarizing plates were referred to as Comparative Examples 1 to 4.

(Adhesion evaluation test)
Corona treatment is applied to the stretched protective film surface of the polarizing plate produced in Examples 1 to 14 and Comparative Examples 1 to 4, and then an acrylic pressure-sensitive adhesive sheet is bonded to the treated surface to provide a pressure-sensitive adhesive polarizing plate. It was. A test piece having a width of 25 mm and a length of about 200 mm was cut from the obtained polarizing plate with the pressure-sensitive adhesive, and the pressure-sensitive adhesive surface was bonded to soda glass. Next, a cutter blade was inserted between the polarizer and the stretched acrylic film, and 30 mm was peeled from the end in the length direction, and stored under the following conditions.

Condition 1: storage for 1 day in an atmosphere of temperature 23 ° C. and relative humidity 60% Condition 2: storage for 1 day in an atmosphere of temperature 60 ° C. and relative humidity 90%

After storage under the above conditions, the peeled part was grasped with a grasping part of a universal tensile tester [“AG-1” manufactured by Shimadzu Corporation]. The test piece in this state was subjected to JIS K 6854-2: 1999 “Adhesive—Peeling peel strength test method—Part 2: 180 degree peeling” in an atmosphere at a temperature of 23 ° C. and a relative humidity of 55%. A 180 degree peeling test was performed at a gripping moving speed of 300 mm / min, and an average peeling force over a length of 170 mm excluding 30 mm of the gripping part was obtained. The results are shown in Table 2.
The adhesion is better as the value of the average peeling force is larger.
If the base material is torn when determining the peeling force, it is considered as material breakage and the adhesion is sufficiently strong.
“Peeling” in condition 2 is that the stretched protective film and the polarizer are peeled off by storing in an atmosphere of a temperature of 60 ° C. and a relative humidity of 90% for one day, and the adhesion is weak.
In each of the measurement conditions of Condition 1 and Condition 2, a polarizing plate having good adhesion is preferable.

[2] Warm water resistance test Each polarizing plate was subjected to the following warm water resistance test (warm water immersion test) to evaluate the water resistance.
First, a sample was prepared by cutting the polarizing plate into a strip of 5 cm × 2 cm with the absorption axis (stretching direction) of the polarizing plate as the long side, and the dimension in the long side direction was accurately measured. At this time, the sample is uniformly colored over the entire surface due to iodine adsorbed on the polyvinyl alcohol film. 1A and 1B are diagrams schematically showing a water resistance evaluation test method. FIG. 1A shows a sample before hot water immersion, and FIG. 1B shows a sample after hot water immersion. As shown in FIG. 1 (A), one short side of the sample was gripped by the gripping part 5, and about 80% of the longitudinal direction was immersed in a water bath at 60 ° C. and held for 4 hours. Then, the sample was taken out from the water tank and the water | moisture content was wiped off.

  The polarizer which comprises a polarizing plate shrink | contracts by warm water immersion. As shown in FIG. 1B, the region 2 in which no polarizer is present between the protective films is formed by shrinking the polarizer located in the middle of the polarizing plate by immersion in warm water. The distance from the end 1a (end of the protective film) of the sample at the center of the short side to the end of the contracted polarizer was taken as the contraction length. In addition, due to immersion in warm water, iodine elutes from the peripheral portion of the polarizer in contact with the hot water, and a portion 3 in which the color is lost is generated at the peripheral portion of the sample. The length of the portion where this color was missing was defined as the iodine missing length. The total of these contraction length and iodine removal length was defined as the total erosion length X. That is, the total erosion length X is the distance from the end 1a (end of the protective film) of the sample to the region where the color peculiar to the polarizing plate remains at the center of the short side of the sample. It can be determined that the smaller the total erosion length X, the higher the adhesion (water resistance) in the presence of water. Moreover, when the extended | stretched protective film and polarizer peel, it is set as peeling and it can be judged that the adhesiveness (water resistance) at the time of water immersion is weak. The results are shown in Table 2.

  The polarizing plate of this invention is used suitably for a liquid crystal panel and a liquid crystal display device.

1: Sample 2: Area where no polarizer exists between protective films 3: Colored part of polarizing plate peripheral part 4: Shrinked polarizer 5: Gripping part

Claims (10)

A polarizing plate in which a stretched protective film is provided on at least one surface of a polarizer via an adhesive layer,
Polarized light which is a cured product of a composition in which the adhesive layer contains more than 35% by mass of a (meth) acrylamide compound having no hydroxyl group as a curable component and does not substantially contain a (meth) acrylamide compound having a hydroxyl group Board.   The polarizing plate according to claim 1, wherein the adhesive layer is a cured product of a composition containing 55 to 90% by mass of a (meth) acrylamide compound having no hydroxyl group. The polarizing plate according to claim 1 or 2, wherein the (meth) acrylamide compound having no hydroxyl group is a compound represented by the formula (1).

Wherein (1), ^{Q 1} represents a hydrogen atom or a methyl group.
Q ² and Q ³ each independently represent a hydrogen atom, an alkoxy group having 1 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms which may have an amino group, or Q ² and Q 3 ³ may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. ] The adhesive layer is a cured product of a composition further comprising a polyfunctional urethane (meth) acrylate compound,
The content of the polyfunctional urethane (meth) acrylate compound in the composition is 10 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. The polarizing plate as described in. The adhesive layer is a cured product of a composition further comprising a polyfunctional (meth) acrylate monomer,
The content of the polyfunctional (meth) acrylic monomer in the composition is 1 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. The polarizing plate as described.   The polarizing plate according to claim 1, wherein the adhesive layer is a cured product of a composition further containing 1 to 40% by mass of a monofunctional (meth) acrylate monomer as a curable component.   The polarizing plate according to claim 1, wherein the stretched protective film is made of a (meth) acrylic resin.   An adhesive composition for a stretched protective film that contains more than 35% by mass of a (meth) acrylamide compound having no hydroxyl group as a curable component and substantially not containing a (meth) acrylamide compound having a hydroxyl group. Furthermore, a composition for an adhesive comprising a polyfunctional urethane (meth) acrylate compound,
The adhesive according to claim 8, wherein the content of the polyfunctional urethane (meth) acrylate monomer in the composition is 10 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. Composition. Furthermore, an adhesive composition containing a polyfunctional (meth) acrylate,
The adhesion according to claim 8 or 9, wherein the content of the polyfunctional (meth) acrylic monomer in the composition is 1 to 45 parts by mass with respect to 100 parts by mass of the (meth) acrylamide compound having no hydroxyl group. Pharmaceutical composition.

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