JP2008233279A - Polarizing plate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate having excellent chip-cutting resistance. <P>SOLUTION: The polarizing plate is formed by layering protective films 5 and 6 composed of a cyclic olefin based resin film on both surfaces of a polarizing film 2 via adhesive layers 3 and 4. The adhesive layers 3 and 4 are composed of a radiation curing composition including: (A) a compound represented by a formula (1); (B) an alicyclic epoxy compound: (C) a compound having at least one hydroxyl group and a number average molecular weight of ≥500; and (D) a photoacid generator. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polarizing plate and a method for producing the same.

In recent years, liquid crystal display devices have been widely used as display devices for displaying characters, images, and the like. Such a liquid crystal display device usually includes a liquid crystal cell composed of two polarizing plates and a glass substrate, a transparent electrode, a color filter, a light distribution film, a liquid crystal, and the like disposed therebetween.
In general, a polarizing plate used in a liquid crystal display device is provided on one or both sides of a polarizing film (polarizer) obtained by adsorbing iodine or a dichroic dye on a stretch-oriented polyvinyl alcohol (hereinafter also referred to as PVA) -based sheet. A protective film such as a triacetyl cellulose (hereinafter also referred to as TAC) film is bonded through an adhesive layer.

As such a polarizing plate, in a polarizing plate in which a protective film is bonded to at least one surface of a polyvinyl alcohol polarizing film via a polyvinyl alcohol adhesive layer, the adhesive layer contains polyvinyl alcohol containing a water-soluble epoxy compound. There has been proposed a polarizing plate comprising an adhesive based on a ratio of a water-soluble epoxy compound and a polyvinyl alcohol resin in the adhesive of (5 to 50) / 100 (solid content weight ratio) ( Patent Document 1). This document also describes that the protective film is triacetyl cellulose having a saponified surface.
According to the technique described in Patent Document 1 using a water-based adhesive and a TAC-based protective film, the adhesive can be cured by evaporating the moisture of the adhesive through the TAC-based protective film having high moisture permeability. . Therefore, a polarizing plate can be obtained by a relatively simple manufacturing process. In addition, since the water-based adhesive and the TAC-based protective film have high adhesiveness, a polarizing plate having excellent adhesive strength can be obtained.
However, because of the high moisture permeability of the TAC protective film, there is a problem that the heat and moisture resistance is low. That is, there is a problem that deformation or the like may occur in a high-temperature and high-humidity environment such as when mounted on a vehicle, and it is difficult to maintain high polarization performance.

Therefore, a method using a cyclic olefin resin film (cycloolefin resin film; hereinafter also referred to as COP resin film) having low moisture permeability instead of the TAC protective film has been proposed.
For example, on one surface of a polarizing film made of a polyvinyl alcohol resin, through a first adhesive layer formed from an aqueous composition containing a polyester ionomer type urethane resin and a compound having a glycidyloxy group. A cycloolefin resin film is laminated, and a cellulose acetate film is laminated on the other surface through a second adhesive layer having an aqueous composition different from that of the first adhesive layer. A polarizing plate is proposed (Patent Document 2).
Moreover, in the manufacturing method of the polarizing plate which adhere | attaches and laminate | stacks a polarizer and the protective film of a polarizer, it contains at least aqueous emulsion, polyvinyl alcohol, and a polyisocyanate compound, and the viscosity (20 degreeC) by a B-type viscosity meter is shown. There has been proposed a method for producing a polarizing plate characterized in that the polarizer and the protective film are wet-laminated using a water-based urethane adhesive adjusted to 0.03 to 1 Pa · s ( Patent Document 3). This document also describes that the protective film is made of a thermoplastic saturated norbornene resin.
Japanese Patent Laid-Open No. 09-258023 JP-A-2005-208456 JP 2004-37841 A

According to the technique described in Patent Document 2, the moisture of the water-based adhesive can be evaporated through a highly moisture-permeable cellulose acetate film, so that polarization can be performed in a relatively simple process as in the technique of Patent Document 1. A board can be obtained.
However, since the cellulose acetate film having high moisture permeability is provided on one side, the problem of insufficient heat and moisture resistance and the adhesion between the first adhesive layer, which is a water-based adhesive, and the cycloolefin resin film are present. There is a problem of being insufficient.
According to the technique described in Patent Document 3, since the protective films on both sides of the polarizer are made of a thermoplastic saturated norbornene-based resin, a polarizing plate having good moisture and heat resistance can be obtained.
However, since a protective film with low moisture permeability is used, it takes a long time to evaporate and cure the water of the water-based urethane adhesive, which is a water-based adhesive, or compared to the case where a TAC-based film is used. There is a problem that the manufacturing process becomes complicated. Moreover, since the protective film which consists of a thermoplastic saturated norbornene-type resin is hydrophobic, there exists a problem that adhesiveness with an aqueous adhesive is inadequate.
On the other hand, when manufacturing a polarizing plate, excellent chip cut resistance is required. That is, the polarizing plate is usually obtained by cutting a laminated sheet for a polarizing plate into a desired size, but at the time of this cutting, peeling (the adhesive layer is missing) at the cutting portion (end after cutting). There is a problem that may occur. This peeling not only lowers the polarization performance of the peeled portion, but also promotes moisture absorption of the polarizing plate and may cause deformation under high temperature and high humidity.
The present invention has been made in view of the above-described background, and can be manufactured in a short time with a simple manufacturing process. Chip cut resistance (no peeling during cutting), moisture heat resistance, protective film -It aims at providing the polarizing plate excellent in the adhesiveness of an adhesive bond layer, etc., and its manufacturing method.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has adhered a polarizing film and a protective film using a radiation curable composition containing a specific component, thereby preventing chip cut resistance, durability, etc. It was found that a polarizing plate excellent in the manufacturing process can be manufactured in a short time by a simple manufacturing process, and the present invention was completed.

（式（１）中、Ｒ^１３、Ｒ^１４及びＲ^１５は、それぞれ独立に、一価の有機基であって、Ｒ^１３〜Ｒ^１５のうち少なくとも２つが、−Ｒ^１６ＯＣＯＣＲ^１７＝ＣＨ_２であり、Ｒ^１６は、炭素数２〜８の２価の有機基であり、Ｒ^１７は、水素原子又はメチル基である。）、（Ｂ）脂環式エポキシ化合物、（Ｃ）水酸基を少なくとも１個含有し、数平均分子量が５００以上である化合物、及び（Ｄ）光酸発生剤、を含む放射線硬化性組成物の硬化物からなることを特徴とする偏光板。
［２］ 上記（Ｃ）成分の数平均分子量が、１，０００以上である前記［１］の偏光板。
［３］ 上記（Ｃ）成分が、下記式（２）で表される化合物
ＨＯ−（Ｒ^１−Ｏ−ＣＯ−Ｏ）_ｍ−（Ｒ^２−Ｏ−ＣＯ−Ｏ）_ｎ−Ｒ^３−ＯＨ （２）
（式中、Ｒ^１およびＲ^２はそれぞれ独立に炭素数２〜１２の２価の炭化水素基を表し、Ｒ^３は、Ｒ^１とＲ^２のいずれかと同じ構造を表す。ｍは２〜１５０、ｎは０〜１５０であり、かつ、ｍ＋ｎは２〜２００である。）である、前記［１］又は［２］の放射線硬化性接着剤用組成物。
［４］ 上記放射線硬化性組成物が、厚さ２００μｍの硬化物としたときに波長５５０ｎｍの光の透過率が７０％以上である、前記［１］〜［３］のいずれかの偏光板。
［５］ 上記保護フィルムが、環状オレフィン系樹脂からなる前記［１］〜［４］のいずれかの偏光板。
［６］ 前記［１］〜［５］のいずれかの偏光板の製造方法であって、偏光膜の少なくとも片面に、上記放射線硬化性組成物を介して保護フィルムを積層する工程と、該放射線硬化性組成物を光照射して硬化させ、偏光板を得る硬化工程を含む偏光板の製造方法。 That is, the present invention provides the following [1] to [6].
[1] A polarizing plate in which a protective film is laminated on at least one surface of a polyvinyl alcohol polarizing film with an adhesive layer interposed therebetween, and the adhesive layer is represented by (A) the following formula (1). Compound

(In the formula ^{(1), R 13, R} 14 and ^{R 15} are each independently a monovalent organic ^group, at least two of R 13 ^{to R 15,} with -R 16 ^OCOCR 17 = CH ₂ R ¹⁶ is a divalent organic group having 2 to 8 carbon atoms, and R ¹⁷ is a hydrogen atom or a methyl group.), (B) an alicyclic epoxy compound, (C) at least one hydroxyl group. A polarizing plate comprising a cured product of a radiation curable composition containing a compound having a number average molecular weight of 500 or more and (D) a photoacid generator.
[2] The polarizing plate according to [1], wherein the number average molecular weight of the component (C) is 1,000 or more.
[3] A compound in which the component (C) is represented by the following formula (2): HO— (R ¹ —O—CO—O) _m — (R ² —O—CO—O) _n —R ³ —OH (2)
(In the formula, R ¹ and R ² each independently represent a divalent hydrocarbon group having 2 to 12 carbon atoms, R ³ represents the same structure as either R ¹ or R ² , and m represents ² to 150. , N is 0 to 150, and m + n is 2 to 200.) The composition for a radiation curable adhesive according to the above [1] or [2].
[4] The polarizing plate according to any one of [1] to [3], wherein when the radiation curable composition is a cured product having a thickness of 200 μm, the transmittance of light having a wavelength of 550 nm is 70% or more.
[5] The polarizing plate according to any one of [1] to [4], wherein the protective film is made of a cyclic olefin resin.
[6] The method for producing a polarizing plate according to any one of [1] to [5], wherein a step of laminating a protective film on at least one surface of the polarizing film via the radiation curable composition, and the radiation A method for producing a polarizing plate comprising a curing step of obtaining a polarizing plate by curing the curable composition by light irradiation.

Since the polarizing plate of the present invention is made of a cured product of a radiation curable composition having a specific component composition, the chip has excellent chip cut resistance (the adhesive layer does not peel off during cutting). Have.
Since the polarizing plate of the present invention is composed of a cured product of a non-aqueous radiation curable composition having a specific component composition for the adhesive layer, even if a non-moisture permeable cyclic olefin resin film is used as a protective film, Good adhesiveness can be obtained in a short time without the need for moisture transpiration. Moreover, a cyclic olefin resin film can also be applied as a protective film on both surfaces of the polarizing film. In this case, particularly excellent moisture and heat resistance can be obtained, and high polarization performance can be maintained even in a high temperature and high humidity environment.
According to the method for producing a polarizing plate of the present invention, a protective film is laminated on one side or both sides of a polarizing film via a radiation curable composition for forming an adhesive layer, and the radiation curable composition is irradiated with radiation. A polarizing plate can be produced by a simple operation of curing. Therefore, it is not necessary to remove moisture as in the case of using a water-based adhesive. Further, even when a non-moisture permeable cyclic olefin-based resin film is used as a protective film, the production process does not become complicated and time-consuming as in the case of using an aqueous adhesive, and each A polarizing plate that is a laminated film having excellent interlayer adhesion can be obtained.

The polarizing plate of the present invention is a polarizing plate in which a protective film is laminated on one side or both sides of a polyvinyl alcohol polarizing film via an adhesive layer.
First, components (A) to (D) and other optional components of the radiation curable composition forming the adhesive layer will be described in detail.

（式（１）中、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立に、一価の有機基であって、Ｒ^１３〜Ｒ^１５のうち少なくとも２つが、−Ｒ^１６ＯＣＯＣＲ^１７＝ＣＨ_２であり、Ｒ^１６は、炭素数２〜８の２価の有機基であり、Ｒ^１７は、水素原子又はメチル基である。） [Component (A)]
The component (A) constituting the radiation curable adhesive composition is an isocyanuric acid derivative having a polymerizable unsaturated group represented by the following formula (1).

(In the formula (1), R ¹ , R ² and R ³ are each independently a monovalent organic group, and at least two of R ^{13 to} R ¹⁵ are represented by -R ¹⁶ OCOCR ¹⁷ = CH ₂ . Yes, R ¹⁶ is a divalent organic group having 2 to 8 carbon atoms, and R ¹⁷ is a hydrogen atom or a methyl group.)

  The component (A) used in the present invention has a function of improving the curability (curing speed) of the radiation-curable adhesive composition.

  The component (A) preferably has two or more polymerizable unsaturated groups in the molecule. The polymerizable unsaturated group is not particularly limited, but is preferably a (meth) acrylate group. By having two or more polymerizable unsaturated groups, the crosslinking density is increased, and the decrease in hardness due to the addition thereof can be reduced.

  Specific examples of the component (A) that can be used in the present invention include tris [2- (meth) acryloyloxyethyl] isocyanurate, bis [2- (meth) acryloyloxyethyl) (2-hydroxyethyl) isocyanurate. Bis [2- (meth) acryloyloxyethyl] isocyanurate, and (meth) acrylates of ethylene oxide (EO), propylene oxide, or caprolactam adducts to these starting alcohols. Of these, tris [2- (meth) acryloyloxyethyl] isocyanurate and bis [2- (meth) acryloyloxyethyl) (2-hydroxyethyl) isocyanurate are particularly preferred.

As a commercial item which can be used suitably as a component (A), Aronix M-215, M-313, M-315, M-325, M-326, M-327 (above, Toa Gosei Chemical Co., Ltd. product) SR-368 (manufactured by Sartomer) and the like. Said compound can be used individually by 1 type or in combination of 2 or more types.
The content of the component (A) used in the present invention is preferably 3 to 40% by mass, more preferably 5 to 35% by mass, particularly preferably, based on 100% by mass of the total composition excluding the organic solvent. It is 7-30 mass%. If it is less than 3% by mass, the curability immediately after light irradiation may be insufficient, and if it exceeds 40% by mass, the adhesive strength with the PVA-based molded product may be inferior.

[Component (B)]
Component (B) constituting the radiation curable composition is an alicyclic epoxy compound, preferably an alicyclic epoxy compound having two or more alicyclic epoxy groups in one molecule. When an alicyclic epoxy compound having two or more alicyclic epoxy groups in one molecule is contained in an amount of 50% by mass or more in the total amount of the component (B), good curing speed and mechanical strength can be maintained.
Specific examples of the alicyclic epoxy compound used as the component (B) include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5 -Spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6 -Methylcyclohexyl-3 ', 4'-epoxy-6'-methylcyclohexanecarboxylate, ε-caprolactone modified 3,4-epoxycyclohexylmethyl-3', 4'-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4- Epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), diethylene glycol (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate), epoxycyclohexahydrophthalic acid dioctyl, epoxycyclohexahydrophthalic acid di-2-ethylhexyl and the like.

  Among these alicyclic epoxy compounds, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, ε-caprolactone modified 3,4-epoxy Cyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3,4-epoxy More preferred is cyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexane Cyclohexylmethyl) adipate is more preferable.

  These commercially available products include Celoxide 2021, Celoxide 2021P, Celoxide 2081, Celoxide 2083, Celoxide 2085, Epolide GT-300, Epolide GT-301, Epolide GT-302, Epolide GT-400, Epolide 401, Epolide 403 (or more, Daicel Chemical Industries, Ltd.).

  The content of the (B) alicyclic epoxy compound in the radiation curable composition is preferably 20 to 80% by mass, more preferably 25 to 75% by mass, and particularly preferably 30 to 70% by mass. When the content is less than 20% by mass, the mechanical strength and heat resistance of the adhesive layer tend to be insufficient. When this content rate exceeds 80 mass%, there exists a tendency for deformation | transformation, such as curvature of the adhesive bond layer formed by hardening | curing a radiation-curable composition, to become large.

[Component (C)]
Component (C) constituting the radiation curable adhesive composition is a compound containing one or more hydroxyl groups and having a number average molecular weight of 500 or more.
Component (C) has one or more, preferably 1 to 4, hydroxyl groups in one molecule.
The number average molecular weight of the component (C) is 500 or more, preferably 1,000 or more, more preferably 1,500 or more. The upper limit of the average molecular weight is not particularly limited, but is preferably 20,000, more preferably 10,000 from the viewpoint of preventing an excessive increase in the viscosity of the adhesive composition. When the average molecular weight is less than 500, the chip cut resistance (cutting resistance) cannot be sufficiently improved, which is not preferable.
The number average molecular weight of the component (C) is a value measured according to ASTM D2503.
By using the component (C), a laminated film having excellent chip cut resistance can be obtained.

  Examples of the compound suitably used as component (C) include polycaprolactone diol, polyether diol, polyester diol, and other polyols.

  Examples of the polycaprolactone diol include polycaprolactone diol obtained by reacting ε-caprolactone and diol. Examples of the diol used here include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,2-polybutylene glycol, 1,6-hexanediol, neopentyl glycol, Examples include 1,4-cyclohexanedimethanol and 1,4-butanediol. Examples of commercially available products of these polycaprolactone diols include Plaxel 205, 205H, 205AL, 212, 212AL, 220, and 220AL (manufactured by Daicel Chemical Industries, Ltd.).

As the polyether diol, an aliphatic polyether diol is preferable, for example,
Examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, and polydecamethylene glycol. Commercial products of these polyether diols include PEG
Examples include # 600, # 1000, # 1500, # 1540, # 4000 (manufactured by Lion Corporation), Exenol 720, 1020, 2020, 3020, 510, Preminol PPG4000 (manufactured by Asahi Glass Co., Ltd.), and the like.

  The polyester diol is preferably a copolymer of an aliphatic diol compound and an aliphatic dicarboxylic acid compound. Examples of the aliphatic diol compound include 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 3-methyl- 1,5-pentanediol and the like, and examples of the aliphatic dicarboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid and the like. One or more aliphatic diols can be used, and one or more aliphatic dicarboxylic acids can be used. Commercially available products of these polyester diols include Kuraray polyol N-2010, O-2010, P-510, P-1010, P-1050, P-2010, P-2050, P-3010, P-3050 (or more, Kuraray Co., Ltd.).

Examples of other polyols include trihydric or higher polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol, sorbitol, sucrose, and quadrol, ethylene oxide (EO), propylene oxide (PO), butylene oxide, tetrahydrofuran, and the like. A polyether polyol obtained by modifying with a cyclic ether compound of Specific examples of such compounds include EO-modified trimethylolpropane, PO-modified trimethylolpropane, tetrahydrofuran-modified trimethylolpropane, EO-modified glycerol, PO-modified glycerol, tetrahydrofuran-modified glycerol, EO-modified pentaerythritol, PO-modified pentaerythritol, Tetrahydrofuran-modified pentaerythritol, EO-modified sorbitol, PO-modified sorbitol, EO-modified sucrose, PO-modified sucrose, EO-modified sucrose, EO-modified quadrole, etc. can be exemplified, and among these, EO-modified trimethylolpropane, PO-modified trimethylol Propane, PO-modified glycerin and PO-modified sorbitol are preferred.
Commercially available products of the above other polyols include Sannix TP-700, Sannix GP-1000, Sannix SP-750, Sannix GP-600 (manufactured by Sanyo Chemical Co., Ltd.), and the like. .

  Moreover, as a polyol used suitably as a component (C), the polymer of a hydroxyl-containing unsaturated compound can be mentioned. Examples of the hydroxyl group-containing unsaturated compound include a hydroxyl group-containing (meth) acrylate. Specifically, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, 1,6- Hexanediol mono (meth) acrylate, neopentylglycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethanedi (meth) acrylate, pentaerythritol tri (meth) acrylate , Dipentaerythritol penta (meth) acrylate. Furthermore, the compound obtained by addition reaction of glycidyl group containing compounds, such as alkyl glycidyl ether, allyl glycidyl ether, and glycidyl (meth) acrylate, and (meth) acrylic acid is mentioned.

The component (C) is also preferably a polycarbonate diol represented by the following formula (2).
HO— (R ¹ —O—CO—O) _m — (R ² —O—CO—O) _n —R ³ —OH (2)
(In the formula, R ¹ and R ² each independently represent a divalent hydrocarbon group having 2 to 12 carbon atoms, R ³ represents the same structure as either R ¹ or R ² , and m represents ² to 150. , N is 0 to 150, and m + n is 2 to 200.)
The method for producing the polycarbonate diol represented by the above formula (2) is not particularly limited, and examples thereof include known methods such as a transesterification reaction between a diol compound and a carbonate compound, and a polycondensation reaction between a diol compound and phosgene. . Examples of the diol compound used for producing the component (C) include 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and 2-methyl. -1,8-octanediol and the like. Moreover, in order to obtain moderate chip cut resistance (cutting resistance) and peel strength, an aliphatic hydrocarbon group having 6 carbon atoms such as 1,6-hexanediol and 3-methyl-1,5-pentanediol is used. The polycarbonate diol to contain is more preferable.

  Commercially available compounds suitable for use as the polycarbonate diol include DN-980, 981, 982, 983 (manufactured by Nippon Polyurethane Co., Ltd.), PC-8000 (manufactured by PPG), PC-THF-CD (manufactured by BASF). ), Kuraray polyol C-590, C-1090, C-2050, C-2090, C-3090, C-2065N, C-2015N (above, manufactured by Kuraray Co., Ltd.), Plaxel CD CD210PL, Plaxel CD CD220PL (above And Daicel Chemical Industries, Ltd.).

  In the composition for radiation curable adhesive, the content of component (C) is preferably 3 to 50% by mass, more preferably 5 to 45% by mass, and particularly preferably 7 to 40% by mass. When the content is less than 3% by mass, the chip cut resistance of the adhesive layer is inferior, which is not preferable. On the other hand, if the content exceeds 50% by mass, the viscosity of the radiation curable adhesive composition becomes too high, resulting in poor coating properties, and poor adhesive strength between the adhesive layer and the adherend. Therefore, it is not preferable.

[Component (D)]
Component (D) constituting the radiation curable composition is a photoacid generator.
The photoacid generator is a photocationic polymerization initiator that releases Lewis acid upon receiving light.
Examples of the photoacid generator include an onium salt having a structure represented by the following general formula (3). This onium salt has a substantial light absorption wavelength below 400 nm.
_{^{[R 4 a R 5 b R}} 6 c R 7 d Z] p + [MX q + p] p- (3)
(Wherein the cation is an onium ion, Z represents S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl or N≡N, and R ⁴ , R ⁵ , R ⁶ and R ⁷ represents an organic group which is the same or different from each other, a, b, c and d are each an integer of 0 to 3, and (a + b + c + d-1) is equal to the valence of Z. M is a halide. The metal or metalloid which comprises the central atom of a complex [ _{MXq + p} ] is shown, for example, B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, X is a halogen atom such as F, Cl, Br, etc., p is the net charge of the halide complex ion, and q is the valence of M.)

In the general formula (3), specific examples of the onium ion include diphenyliodonium, 4-methoxydiphenyliodonium, bis (4-methylphenyl) iodonium, bis (4-tert-butylphenyl) iodonium, bis (dodecylphenyl). Diaryliodonium such as iodonium, triarylsulfonium such as triphenylsulfonium and diphenyl-4-thiophenoxyphenylsulfonium, bis [4- (diphenylsulfonio) -phenyl] sulfide, bis [4- (di (4- ( 2-hydroxyethyl) phenyl) sulfonio) -phenyl] sulfide, η ⁵ -2,4- (cyclopentadienyl) [1,2,3,4,5,6-η]-(methylethyl) -benzene] -Iron (1+) etc. are mentioned.
In the general formula (2), specific examples of the anion [MX _{q + p} ] include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarce. Nate (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ) and the like.
Moreover, the onium salt which has an anion represented with general formula [ _MXq (OH) < ^- >] can be used. Further, perchlorate ion (ClO ₄ ⁻ ), trifluoromethane sulfonate ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluene sulfonate ion, trinitrobenzene sulfonate anion, trinitrotoluene sulfonate Onium salts having other anions such as anions can also be used.

  Examples of onium salts used as component (D) include aromatic halonium salts described in, for example, JP-A-50-151996, JP-A-50-158680, JP-A-50-151997, VIA group aromatic onium salts described in JP-A-52-30899, JP-A-56-55420, JP-A-55-125105, etc., VA described in JP-A-50-158698, etc. Aromatic aromatic onium salts, oxosulfoxonium salts described in JP-A-56-8428, JP-A-56-149402, JP-A-57-192429, etc., JP-A-49-17040 And aromatic thiobililium salts described in US Pat. No. 4,139,655. Moreover, an iron / allene complex, an aluminum complex / photolytic silicon compound-based initiator, and the like can also be mentioned. Photoacid generators preferably used as component (D) are aromatic onium salts such as diaryl iodonium salts and triarylsulfonium salts, and more preferably triarylsulfonium salts.

(D) Examples of commercially available photoacid generators include UVI-6950, UVI-6970, UVI-6974, UVI-6990 (manufactured by Union Carbide), Adekaoptomer SP-150, SP-151, SP-170, SP-172 (above, manufactured by Asahi Denka Kogyo Co., Ltd.), Irgacure
261 (above, manufactured by Ciba Specialty Chemicals Co., Ltd.), CI-2481, CI-2624, CI-2639, CI-2064 (above, manufactured by Nippon Soda Co., Ltd.), CD-1010, CD-1011, CD -1012 (above, manufactured by Sartomer), DTS-102, DTS-103, NAT-103, NDS-103, TPS-103, MDS-103, MPI-103, BBI-103 (above, manufactured by Midori Chemical Co., Ltd.) ), PCI-061T, PCI-062T, PCI-020T, PCI-022T (above, Nippon Kayaku Co., Ltd.), CPI-110A, CPI-101A (above, San Apro Co., Ltd.) and the like. . Among these, UVI-6970, UVI-6974, Adeka optomer SP-170, SP-172, CD-1012, MPI-103, CPI-110A, CPI-101A are high in the composition containing them. It is particularly preferable because photocuring sensitivity can be expressed. Said photo-acid generator can be used individually by 1 type or in combination of 2 or more types.
A sensitizer may be used in combination in order to promote the generation of acid by the photoacid generator. Examples of the sensitizer include dihydroxybenzene, trihydroxybenzene, hydroxyacetophenone, dihydroxydiphenylmethane, and the like.

  In the radiation curable composition, the content of the photoacid generator (D) is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, and particularly preferably 0.3 to 3% by mass. It is. When the content is less than 0.1% by mass, the radiation curability of the radiation curable composition is lowered, and an adhesive layer having sufficient mechanical strength cannot be formed. If the content exceeds 10% by mass, the photoacid generator may adversely affect the long-term characteristics of the adhesive layer, which is not preferable.

[Component (E)]
The radiation curable composition may further contain an aliphatic epoxy compound as component (E). The component (E) aliphatic epoxy compound is an optional component added to control the mechanical strength and the like of the adhesive layer.
Specific examples of the aliphatic epoxy compound include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and polyethylene glycol diglycidyl. Ether, glycerin triglycidyl ether, polypropylene glycol diglycidyl ethers; polyether polyol obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, etc. Diglycidyl esters of aliphatic long-chain dibasic acids; Monoglycidyl ethers of higher aliphatic alcohols; Glycidyl esters of higher fatty acids Le acids; epoxidized soybean oil; butyl epoxy stearate, epoxy stearic octyl, epoxidized linseed oil, epoxy polybutadiene, and the like.

  In the radiation curable composition, the content of the (E) aliphatic epoxy compound is preferably 0 to 50% by mass, more preferably 0 to 45% by mass, and particularly preferably 0 to 40% by mass. When the content exceeds 50% by mass, the content of the essential component (B) alicyclic epoxy compound and the like is decreased, and the effects of the present invention are hardly obtained, which is not preferable.

Moreover, various additives can be mix | blended with the radiation-curable composition used by this invention as another arbitrary component in the range which does not impair the objective and effect of this invention. Such additives include epoxy resin, polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine-based oligomer, Polymers or oligomers such as silicone oligomers and polysulfide oligomers; polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization initiators; leveling agents; wettability improvers; Plasticizers; UV absorbers; silane coupling agents; inorganic fillers; pigments; dyes and the like.
The radiation curable composition can be prepared by uniformly mixing the components (A) to (D) and, if necessary, the optional components. The viscosity (25 ° C.) of the radiation curable composition thus obtained is usually 2,000 mPa · s or less, preferably 500 mPa · s or less, more preferably 300 mPa · s or less.
In addition, solvents, such as an organic solvent, can be added to a radiation curable composition as needed. However, in the present invention, the radiation curable composition can be prepared even without solvent. In this invention, it is preferable not to contain a solvent from surfaces, such as maintenance of work environment and an environmental load.
The radiation curable adhesive composition has a light transmittance of 550 nm when the cured product has a thickness of 200 μm, preferably 70% or more, more preferably 80% or more. If the transmittance is less than 70%, the transmittance of the polarizing plate itself is also not preferable.
Moreover, it is also preferable to use what was filtered with the filter etc. for the radiation-curable composition.

Next, the polarizing plate of the present invention and the manufacturing method thereof will be described with reference to the drawings as appropriate.
FIG. 1 is a cross-sectional view schematically showing an example of the polarizing plate of the present invention. FIG. 2 is a flowchart showing an example of a method for producing a polarizing plate of the present invention.
In FIG. 1, a polarizing plate 1 includes a polyvinyl alcohol polarizing film 2, adhesive layers 3 and 4 formed on both surfaces (lower surface and upper surface) of the polarizing film 2, and each of the adhesive layers 3 and 4. It consists of protective films 5 and 6 formed by being laminated on one side (specifically, the lower surface of the adhesive layer 3 and the upper surface of the adhesive layer 4).

[Polarizing film]
As the polarizing film, a polyvinyl alcohol polarizing film (hereinafter also referred to as a PVA polarizing film) is used. The PVA polarizing film is generally used as a polarizing film, and is stretched and oriented by adsorbing iodine or a dichroic dye on a polyvinyl alcohol film.
The thickness of the polarizing film is not particularly limited, but is determined to be, for example, 10 to 40 μm.
[Adhesive layer]
An adhesive bond layer is a hardened | cured material layer formed by carrying out the radiation curing of the above-mentioned radiation-curable composition.
By forming an adhesive layer using the radiation curable composition described above, excellent chip cut resistance can be obtained, and even if the protective film is COP type or TAC type, the protective film The adhesive strength between the adhesive layer and the adhesive layer can be made excellent.
Although the thickness of an adhesive bond layer is not specifically limited, For example, it determines so that it may become 0.01-5.0 micrometers.

[Protective film]
Examples of the protective film include acetate resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate resin, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and cyclic olefins. A film made of an optically transparent resin such as an acrylic resin or an acrylic resin is used. Among these, a cyclic olefin resin film (COP film) and a triacetyl cellulose resin film (TAC film) are preferable.
Examples of the configuration of the polarizing plate include the following (1) to (3).
(1) TAC film / adhesive layer / PVA polarizing film / adhesive layer / TAC film (2) TAC film / adhesive layer / PVA polarizing film / adhesive layer / COP film (3) COP Film / Adhesive Layer / PVA Polarizing Film / Adhesive Layer / COP Film In the present invention, it is preferable that at least one protective film is a COP film. That is, as a structure of a polarizing plate, said (2) and (3) are preferable and said (3) is more preferable. According to the configurations of (2) and (3) above, since a COP film having low moisture permeability is used as a protective film, a polarizing plate having excellent moisture and heat resistance can be obtained.

In the present invention, of the upper and lower protective films, one of the protective films needs to be an ultraviolet absorber-preventing protective film, and the other protective film needs to be an ultraviolet transmissive protective film.
The UV-protective protective film plays a role of protecting the liquid crystal cell from external ultraviolet rays when the polarizing plate is disposed on both surfaces of the liquid crystal cell. An ultraviolet absorber is appropriately blended in the ultraviolet protective protective film. The light transmittance at a wavelength of 380 nm of the ultraviolet protective film is, for example, 10% or less.
The said ultraviolet-permeable protective film is for hardening a radiation-curable composition by performing radiation irradiation (light irradiation) from the said protective film side. The ultraviolet ray transmissive protective film does not contain an ultraviolet absorber or contains an ultraviolet absorber so that the radiation curable composition can be cured by irradiating light through the protective film. The transmittance of light at a wavelength of 380 nm of the ultraviolet transparent protective film is, for example, 60% or more.

A retardation can also be provided in the protective film.
Although the thickness of a protective film is not specifically limited, For example, it determines so that it may become 10-200 micrometers.
The protective film can also be subjected to various surface treatments before application of the radiation curable composition.

(Cyclic olefin resin film)
In addition, as the above-mentioned cyclic olefin-based resin film, a film made of a resin obtained by polymerizing a monomer composition containing at least one cyclic olefin-based compound and further hydrogenating as necessary is suitable. is there.
As said cyclic olefin type compound, the cyclic olefin type compound represented by following General formula (4) can be mentioned, for example.

(In Formula (4), R ^{8 to} R ¹¹ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted carbon atom which may have a linking group containing oxygen, nitrogen, sulfur or silicon. It represents a 1-15 hydrocarbon group or other monovalent organic group. Alternatively ^{R 8} and ^{R 9} or ^{R 10} and ^{R 11} are bonded to each other may form an alkylidene group, ^{R 8} and R ⁹ , R ¹⁰ and R ¹¹ or R ⁹ and R ¹⁰ are bonded to each other to form a carbocyclic or heterocyclic ring (these carbocyclic or heterocyclic rings may have a monocyclic structure, or other rings may be condensed to form a polycyclic ring). The formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring, and x is 0 or an integer of 1 to 3, y is Represents 0 or 1, but when x is 0, y is also 0.)

Specific examples of the cyclic olefin compound represented by the general formula (4) include, but are not limited to, the following compounds.
Bicyclo [2.2.1] hept-2-ene (norbornene)
5-methyl-bicyclo [2.2.1] hept-2-ene, 5-ethyl-bicyclo [2.2.1] hept-2-ene, 5-cyclohexyl-bicyclo [2.2.1] hept 2-ene-5-phenyl-bicyclo [2.2.1] hept-2-ene-5- (4-biphenyl) -bicyclo [2.2.1] hept-2-ene-5-methoxycarbonyl- Bicyclo [2.2.1] hept-2-ene · 5-phenoxycarbonyl-bicyclo [2.2.1] hept-2-ene · 5-phenoxyethylcarbonyl-bicyclo [2.2.1] hept-2 -Ene, 5-phenylcarbonyloxy-bicyclo [2.2.1] hept-2-ene, 5-methyl-5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-methyl- 5-phenoxycarboni -Bicyclo [2.2.1] hept-2-ene.5-methyl-5-phenoxyethylcarbonyl-bicyclo [2.2.1] hept-2-ene.5-vinyl-bicyclo [2.2.1] ] Hept-2-ene, 5-ethylidene-bicyclo [2.2.1] hept-2-ene, 5,5-dimethyl-bicyclo [2.2.1] hept-2-ene, 5,6-dimethyl -Bicyclo [2.2.1] hept-2-ene, 5-fluoro-bicyclo [2.2.1] hept-2-ene, 5-chloro-bicyclo [2.2.1] hept-2-ene 5-bromo-bicyclo [2.2.1] hept-2-ene5,6-difluoro-bicyclo [2.2.1] hept-2-ene5,6-dichloro-bicyclo [2.2 .1] Hept-2-ene-5,6-dibromo-bicyclo [2.2.1 Hept-2-ene, 5-hydroxy-bicyclo [2.2.1] hept-2-ene, 5-hydroxyethyl-bicyclo [2.2.1] hept-2-ene, 5-cyano-bicyclo [2 2.1] hept-2-ene, 5-amino-bicyclo [2.2.1] hept-2-ene, tricyclo [4.3.0.1 ^2,5 ] dec-3-ene, tricyclo [ 4.4.0.1 ^2,5 ] Undec-3-ene.7-methyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene.7-ethyl-tricyclo [4.3. 0.1 ^2,5] dec-3-ene-7-cyclohexyl - tricyclo [4.3.0.1 ^2,5] dec-3-ene-7-phenyl - tricyclo [4.3.0.1 ^{2 , 5]} dec-3-ene-7- (4-biphenyl) - tricyclo [4.3.0.1 ^{2, 5]} dec-3-ene-7,8 Methyl - tricyclo [4.3.0.1 ^{2, 5]} dec-3-ene-7,8,9- trimethyl - tricyclo [4.3.0.1 ^{2, 5]} dec-3-ene-8- Methyl-tricyclo [4.4.0.1 ^2,5 ] undec-3-ene · 8-phenyl-tricyclo [4.4.0.1 ^2,5 ] undec-3-ene · 7-fluoro-tricyclo [ 4.3.0.1 ^2,5 ] dec-3-ene.7-chloro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene.7-bromo-tricyclo [4.3. 0.1 ^2,5] dec-3-ene-7,8-dichloro - tricyclo [4.3.0.1 ^2,5] dec-3-ene-7,8,9- trichloro - tricyclo [4. 3.0.1 ^2,5 ] dec-3-ene · 7-chloromethyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene · 7-dichloromethyl-tricycl B [4.3.0.1 ^2,5 ] dec-3-ene · 7-trichloromethyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene · 7-hydroxy-tricyclo [4 .3.0.1 ^2,5 ] dec-3-ene · 7-cyano-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene · 7-amino-tricyclo [4.3.0 .1 ^2,5] deca-3-ene-tetracyclo [4.4.0.1 ^2,5. 1 ^7,10 ] dodec-3-ene pentacyclo [7.4.0.1 ^2,5 . 1 ^8,11 . 0 ^7,12] pentadeca-3-ene-hexacyclo [8.4.0.1 ^2,5. 1 ^7,14 . 1 ^9,12 . 0 ^8,13] heptadec-3-en-8-methyl - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10] dodeca-3-ene-8-ethyl - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10] dodeca-3-ene-8-cyclohexyl - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] dodec-3-ene-8-phenyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8- (4-biphenyl) -tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10] dodeca-3-ene-8-methoxycarbonyloxy - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] dodec-3-ene-8-phenoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10] dodeca-3-ene-8-phenoxyethyl carbonyl - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] dodec-3-ene-8-phenylcarbonyloxy-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-methyl-8-methoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-methyl-8-phenoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-methyl-8-phenoxyethylcarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-vinyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10] dodeca-3-ene-8-ethylidene - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10] dodeca-3-ene-8,8-dimethyl - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10] dodeca-3-ene-8,9-dimethyl - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] dodec-3-ene-8-fluoro-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-chloro-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10] dodeca-3-ene-8-bromo - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] dodec-3-ene.8,8-dichloro-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene.8,9-dichloro-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene. 8,8,9,9-tetrachloro-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-hydroxy-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-hydroxyethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene-8-methyl-8-hydroxyethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10] dodeca-3-ene-8-cyano - tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] dodec-3-ene-8-amino-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene In addition, these cyclic olefin type compounds may be used individually by 1 type, and may use 2 or more types together.

The kind and amount of the cyclic olefin compound are appropriately selected depending on the properties required for the obtained resin.
As the cyclic olefin compound, a compound having a structure (hereinafter referred to as “polar structure”) containing at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom in the molecule. When used, it is preferable because it is excellent in adhesion and adhesion to other materials. In particular, in the formula (4), R ⁸ and R ¹⁰ are a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, preferably a hydrogen atom or a methyl group, and any one of R ^{9 and} R ¹¹ is A compound having a polar structure and the other being a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms is preferable because the water absorption (wet) property of the resin is low. Furthermore, a cyclic olefin compound in which the group having a polar structure is a group represented by the following general formula (5) is easy to balance the heat resistance and water absorption (wet) property of the resulting resin, and can be preferably used. .

-(CH ₂ ) _z COOR ¹² (5)
(In formula (5), R ¹² represents a substituted or unsubstituted hydrocarbon group having 1 to 15 carbon atoms, and z represents an integer of 0 to 10)
In general formula (5), the smaller the value of z, the higher the glass transition temperature of the resulting hydrogenated product and the better the heat resistance. Therefore, z is preferably an integer of 0 to 3. Furthermore, the monomer whose z is 0 is preferable in that its synthesis is easy. In addition, R ¹² in the general formula (5) tends to decrease the water absorption (wet) property of the resulting hydrogenated polymer as the carbon number increases, but also tends to decrease the glass transition temperature. Therefore, from the viewpoint of maintaining heat resistance, a hydrocarbon group having 1 to 10 carbon atoms is preferable, and a hydrocarbon group having 1 to 6 carbon atoms is particularly preferable.

  In the general formula (4), when an alkyl group having 1 to 3 carbon atoms, particularly a methyl group, is bonded to the carbon atom to which the group represented by the general formula (5) is bonded, heat resistance and water absorption It is preferable in terms of (wet) balance. Further, in the general formula (4), a compound in which x is 0 or 1, and y is 0 is highly reactive, a polymer can be obtained in a high yield, and polymer hydrogen having high heat resistance. It is preferably used because an additive is obtained and it is industrially easily available.

In the said cyclic olefin type resin, the other monomer which can be copolymerized with the said cyclic olefin type compound is included in a monomer composition, and it can superpose | polymerize.
Examples of other copolymerizable monomers include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and cyclododecene, and non-conjugated cyclic polyenes such as 1,4-cyclooctadiene, dicyclopentadiene, and cyclododecatriene. Can be mentioned.
These other copolymerizable monomers may be used alone or in combination of two or more.

As a polymerization method of the monomer composition containing the cyclic olefin compound, for example, a known method by metathesis ring-opening polymerization or addition polymerization described in JP-A-2006-201736, JP-A-2005-164632, or the like is known. The method can be used.
Moreover, the known method described in said literature can also be used also about the method of hydrogenation of the obtained (co) polymer.
The hydrogenation rate of the hydrogenated polymer is preferably 50% or more, more preferably 70% or more, still more preferably 90% or more, particularly preferably 99% or more as a value measured by 500 MHz and ¹ H-NMR. . The higher the hydrogenation rate, the better the stability to heat and light, and stable characteristics can be obtained over a long period of time.

The intrinsic viscosity [η] _inh of the cyclic olefin resin is preferably 0.2 to 2.0 dl / g, more preferably 0.35 to 1.0 dl / g, and particularly preferably 0.4 to 0.85 dl / g. It is.
The number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) of the cyclic olefin resin is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and particularly preferably 1. 50,000 to 250,000.
The weight average molecular weight (Mw) of the cyclic olefin-based resin is preferably 10,000 to 2,000,000, more preferably 20,000 to 1,000,000, and particularly preferably 30,000 to 500,000.
The glass transition temperature (Tg) of the cyclic olefin resin is preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and particularly preferably 150 ° C. or higher.
The saturated water absorption rate of the cyclic olefin resin is preferably 1% by mass or less, and more preferably 0.1 to 0.8% by mass. When the saturated water absorption exceeds 1% by mass, the protective film obtained from the resin may have a problem in durability such as water absorption (wet) with time and deformation depending on the environment used. On the other hand, if it is less than 0.1% by mass, there may be a problem in adhesion. The saturated water absorption is ASTM
According to D570, it is a value obtained by immersing in 23 ° C. water for 1 week and measuring the increased mass.

In the present invention, additives such as an antioxidant and an ultraviolet absorber can be further added as long as the effects of the present invention are not impaired.
Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2′-dioxy-3,3′-di-t-butyl-5,5′-dimethyldiphenylmethane, tetrakis [ And methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane.
Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone.

(Method for producing cyclic olefin-based resin film)
About the manufacturing method of a cyclic olefin resin film, the well-known method described in Unexamined-Japanese-Patent No. 2006-201736, Unexamined-Japanese-Patent No. 2005-164632, etc. can be used. That is, the cyclic olefin-based resin film can be suitably molded by directly melt-molding the cyclic olefin-based resin or by a method of dissolving and casting in a solvent (cast molding).

Next, the manufacturing method of a polarizing plate is demonstrated.
In the method for producing a polarizing plate of the present invention, a protective film is laminated on at least one surface (specifically, one surface or both surfaces) of a polarizing film via a liquid radiation curable composition, and then the liquid radiation curable composition is used. The composition is cured by irradiation with radiation (for example, ultraviolet rays).
In FIG. 2, the manufacturing method of the polarizing plate 1 includes the step (a) of preparing the polyvinyl alcohol polarizing film 2 and the application of a radiation curable composition for forming an adhesive layer to one side of each of the protective films 5 and 6. Then, the step (b) of obtaining the laminates 5 ′, 6 ′ of the protective films 5, 6 and the radiation curable composition layers 3 ′, 4 ′, and the upper surface and the lower surface of the polyvinyl alcohol polarizing film 2, respectively. The step (c) of laminating the laminates 5 ′ and 6 ′ so that the composition layers 3 ′ and 4 ′ face the surface of the polarizing film 2 and the composition layers 3 ′ and 4 ′ are cured by light irradiation. And the step (d) of forming the adhesive layers 3 and 4 is included.
Hereinafter, it demonstrates for every process.

[Step (a)]
Step (a) is a step of preparing a polyvinyl alcohol polarizing plate 2 (see (a) in FIG. 2).
[Step (b)]
In the step (b), a radiation curable composition for forming an adhesive layer is applied to one surface of the protective film 5 (6), and the protective films 5 ′ and 6 ′ having the composition layers 3 ′ and 4 ′ are applied. This is a obtaining step (see (b) in FIG. 2).
Specifically, a radiation curable composition for forming an adhesive layer is applied to one side of each of the protective films 5 and 6, and drying or the like is performed as necessary to form a layer 3 made of the radiation curable composition. ', 4' is formed.
The method for applying the radiation curable composition is not particularly limited, and examples thereof include a die coating method, a roll coating method, a gravure coating method, and a spin coating method.

[Step (c)]
Step (c) is a step of laminating laminates 5 ′ and 6 ′ of protective films 5 and 6 and radiation curable composition layers 3 ′ and 4 ′ on the upper and lower surfaces of polyvinyl alcohol polarizing film 2. (See (c) in FIG. 2). The stacked body 5 ′ is stacked so that the composition layer 3 ′ faces the lower surface of the polarizing film 2. The stacked body 6 ′ is stacked so that the composition layer 4 ′ faces the upper surface of the polarizing film 2.

[Step (d)]
Step (d) is a step in which the composition layers 3 ′ and 4 ′ are cured by irradiating the radiation 7 to form the adhesive layers 3 and 4 (see (d) and (e) in FIG. 2). ).
Specifically, the radiation 7 is irradiated from the upper surface of the protective film 6. As a result, the radiation curable composition layers 3 ′ and 4 ′ are cured to form adhesive layers 3 and 4, and the polarizing film 2 and the protective films 5 and 6 are bonded via the adhesive layers 3 and 4. The polarizing plate 1 is completed (see (e) in FIGS. 1 and 2).
The dose of radiation is not particularly limited, wavelength 200 to 450 nm, the light intensity 1 to 500 mW / cm ^2, irradiation amount by irradiation so that 10~10,000mJ / cm ² exposure It is preferable to do.
Visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays, and the like can be used as the type of radiation to be irradiated, and ultraviolet rays are particularly preferable. As the light irradiation device, for example, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, an excimer lamp, or the like is preferably used.
In the present invention, radiation is irradiated from the side of the ultraviolet transparent protective film. FIG. 2 shows a case where the protective film 6 is an ultraviolet transmissive protective film.
The obtained polarizing plate is usually used after being subjected to processing such as cutting.

Hereinafter, the present invention will be specifically described by way of examples.
[1. Preparation of radiation curable composition for forming adhesive layer]
Components (A) to (D) and optional components were added to a container equipped with a stirrer at the blending ratio shown in Table 1, and stirred for 4 hours to mix uniformly. Stirring was stopped and the mixture was allowed to stand for 24 hours to obtain a radiation curable composition for forming an adhesive layer used in Examples 1 to 5 (hereinafter sometimes abbreviated as “adhesive composition”). . Similarly, the composition for adhesives used for Comparative Examples 1-5 was obtained.
In addition, the compound name of each component in Table 1 is as follows.
(A-1) Aronics M-315: Tris [2- (meth) acryloyloxycyethyl] isocyanurate (manufactured by Toagosei Co., Ltd.)
(A-2) Aronics M-215: Bis [2- (meth) acryloyloxyethyl) (2-hydroxyethyl) isocyanurate (manufactured by Toagosei Co., Ltd.)
(B) component:
(B-1) Celoxide 2021P: 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate (manufactured by Daicel)
(B-2) KRM2199: Bis (3,4-epoxycyclohexylmethyl) adipate (manufactured by Adeka)
(C) component:
(C-1) Kuraray polyol P-510: Poly [(3-methyl-1,5-pentanediol) -alt- (adipic acid)] (manufactured by Kuraray Co., Ltd .; number average molecular weight 700)
(C-2) Kuraray polyol P-1010: poly [(3-methyl-1,5-pentanediol) -alt- (adipic acid)] (manufactured by Kuraray Co., Ltd .; number average molecular weight 1,000)
(C-3) Kuraray polyol C-2090: poly ((3-methyl-1,5-pentanediol; 1,6-hexanediol) carbonate) (manufactured by Kuraray Co., Ltd .; number average molecular weight 2,000)
(C-4) Kuraray polyol C-590: Poly ((3-methyl-1,5-pentanediol; 1,6-hexanediol) carbonate) (manufactured by Kuraray Co., Ltd .; number average molecular weight 500)
(D) component:
CPI-110A: Diphenyl [4- (phenylthio) phenyl] sulfonium hexafluoroantimonate (manufactured by San Apro)
Other ingredients:
SR-NPG: Neopentyl glycol diglycidyl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd.)
Sanniks GP-400: Polyoxypropylene glyceryl ether (manufactured by Sanyo Chemical Industries)
IRGACURE 184: 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Specialty Chemicals)
Hitaloid 4861: Urethane acrylate (manufactured by Hitachi Chemical Co., Ltd.)
Kayalad DPHA: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)

[2. Production or preparation of adhesive substrate]
[Production Example 1]
“Apel APL6013T” (trade name) manufactured by Mitsui Chemicals was dissolved in cyclopentane to obtain a resin solution having a resin concentration of 30% by mass. This resin solution was applied onto a polyethylene terephthalate film with a bar coater, allowed to stand for 1 hour, and then dried at 80 ° C. for 12 hours to obtain an appel film having a thickness of 72 μm.

[Production Example 2]
A 75 μm topas film was obtained in the same manner as in Production Example except that “TOPAS5013” (trade name) manufactured by Polyplastics was dissolved in methylene chloride.

[Production Example 3]
100 parts by weight of cellulose acetate (oxidation degree 60.8%), 12 parts by weight of triphenyl phosphate, 300 parts by weight of methylene chloride, and 50 parts by weight of methanol are put into a sealed container and kept at 80 ° C. under pressure while stirring. Dissolved completely. The solution was then filtered, cooled and kept at 30 ° C., and applied to a PET film affixed to a crow substrate with a 15 mil applicator. After standing in this state for 5 minutes, drying was further terminated in an oven at 100 ° C. for 1 hour to obtain a TAC film 1 having a film thickness of 80 μm (no ultraviolet absorber).

[Production Example 4]
A staining solution was prepared by dissolving 20 parts by mass of boric acid, 0.2 parts by mass of iodine, and 0.5 parts by mass of potassium iodide in 480 parts by mass of water. A PVA film (Vinylon film # 40, manufactured by Aicello) was immersed in this dyeing solution for 30 seconds, and then the film was stretched twice in one direction and dried to prepare a PVA film having a thickness of 30 μm.
The following were used as other films described in Table 1.
TAC film 2: “Fujitac 80D” (trade name) manufactured by Fuji Photo Film Co., Ltd.
Arton R5300: Product made by JSR (trade name)
Arton R5300U: JSR UV-absorbing film (trade name)
ZEONOR film: "ZEONOR ZF14-100" (trade name) manufactured by ZEON CORPORATION
Films other than PVA film are subjected to corona discharge treatment on the film surface with a discharge amount of 320 W · min / m ² using a corona surface treatment apparatus (“AGF-012” manufactured by Kasuga Denki Co., Ltd.), and after the surface treatment. Adhesion was carried out within 1 hour.

[3. Production of polarizing plate]
[Example 1]
The adhesive composition of Example 1 is coated on the TAC film 2 (protective film 1) using a wire bar coater # 3, and the PVA film of Production Example 4 is free from defects such as bubbles. Were pasted together. Next, on the TAC film 1 (protective film 2) of Production Example 3, the composition for an adhesive of Example 1 was applied using a wire bar coater # 3, and on the PVA of the bonded film, It bonded so that defects, such as a bubble, may not enter. On the glass plate, fix the four sides of the protective film 2 with tape so that the protective film 2 is on top, and from the side of the protective film 2 with a metal halide lamp (illuminance 220 mW / cm ² , irradiation light quantity 1,000 mJ / cm ² ). Irradiated with light.

[Examples 2 to 5, Comparative Examples 1 to 5]
A polarizing plate was produced in the same manner as in Example 1 except that the adhesive composition was changed as shown in Table 1.

[Transmittance of light having a wavelength of 550 nm in the adhesive composition]
A PET film (film thickness: 188 μm, surface untreated product) is fixed on a glass plate with an adhesive, and an adhesive composition (Examples 1-5, Comparative Example) is used on the PET film with a gap 15 mil applicator. 1-5) was applied. This coating film was irradiated with light using a metal halide lamp (illuminance 220 mW / cm ² , irradiation light quantity 1,000 mJ / cm ² ) to cure the adhesive composition, and allowed to stand at 23 ° C. and 50% RH for 24 hours. did. After peeling the cured product from the PET film and confirming that the film thickness is 200 ± 5 μm, using U-3410 self-recording spectrophotometer (manufactured by Hitachi, Ltd.), air is used as a reference for the cured product. The transmittance of light having a wavelength of 550 nm was measured.

[4. Evaluation of polarizing plate]
[Chip cut resistance after standing for 1 hour after light irradiation]
After pasting by light irradiation, a polarizing plate that was allowed to stand at 23 ° C. and 50% RH for 1 hour was used as a super dumbbell cutter (SSK-12862-06, manufactured by Dumbbell) and an SD-type lever-type sample cutter (SDL- 200, manufactured by Dumbbell), and punched out to a size of 50 mm × 80 mm. The periphery of the punched polarizing plate was visually observed to obtain initial characteristics. The case where no peeling was observed was indicated by ◎, the case where a stripe-like pattern was observed at the end but not peeled, and the case where peeling was observed at the end were indicated by ×.

[Chip cut resistance after standing for 24 hours after light irradiation]
After pasting by light irradiation, the sample was allowed to stand at 23 ° C. and 50% RH for 24 hours, and then the chip cut resistance after standing for 24 hours after light irradiation was evaluated according to the same criteria as described above.

[Moisture and heat resistance]
After being bonded by light irradiation, the polarizing plate film that was allowed to stand at 23 ° C. and 50% RH for 24 hours was exposed to an environment of 60 ° C. and 90% RH (relative humidity) for 250 hours. The chip cut resistance was evaluated.
The results are shown in Table 2.

  From Table 2, it can be seen that the polarizing plates of Examples 1 to 5 are excellent in chip cut resistance (after 1 hour, after 24 hours, and after wet heat). On the other hand, it can be seen that the polarizing plates of Comparative Examples 1, 2, 4, and 5 are inferior in chip cut resistance (after 1 hour, after 24 hours, and after wet heat). Moreover, although the polarizing plate of the comparative example 3 is excellent in the chip cut resistance after 24 hours and after wet heat, it turns out that it is inferior to the chip cut resistance (initial chip cut resistance) after 1 hour.

It is sectional drawing which shows typically an example of the polarizing plate of this invention. It is a flowchart which shows an example of the manufacturing method of the polarizing plate of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polarizing plate 2 Polyvinyl alcohol-type polarizing film 3 Adhesive layer 3 'Layer which consists of a radiation-curable composition 4 Adhesive layer 4' Layer which consists of a radiation-curable composition 5 Protective film 5 'The protective film 5 and a radiation-curable composition Laminate with layer 3 ′ made of material 6 Protective film 6 ′ Laminated body with layer 4 ′ made of protective film 6 and radiation curable composition 7 Radiation (ultraviolet)

Claims (6)

A polarizing plate in which a protective film is laminated on at least one surface of a polyvinyl alcohol polarizing film via an adhesive layer, wherein the adhesive layer is (A) a compound represented by the following formula (1)

(In the formula ^{(1), R 13, R} 14 and ^{R 15} are each independently a monovalent organic ^group, at least two of R 13 ^{to R 15,} with -R 16 ^OCOCR 17 = CH ₂ R ¹⁶ is a divalent organic group having 2 to 8 carbon atoms, and R ¹⁷ is a hydrogen atom or a methyl group.), (B) an alicyclic epoxy compound, (C) at least one hydroxyl group. A polarizing plate comprising a cured product of a radiation curable composition containing a compound having a number average molecular weight of 500 or more and (D) a photoacid generator.   The number average molecular weight of the said (C) component is 1,000 or more, The polarizing plate of Claim 1. The component (C) is a compound represented by the following formula (2): HO— (R ¹ —O—CO—O) _m — (R ² —O—CO—O) _n —R ³ —OH (2)
(In the formula, R ¹ and R ² each independently represent a divalent hydrocarbon group having 2 to 12 carbon atoms, R ³ represents the same structure as either R ¹ or R ² , and m represents ² to 150. , N is 0 to 150, and m + n is 2 to 200.) The polarizing plate according to claim 1 or 2.   The polarizing plate according to any one of claims 1 to 3, wherein the radiation curable composition has a transmittance of light having a wavelength of 550 nm of 70% or more when the cured product has a thickness of 200 µm.   The polarizing plate according to claim 1, wherein the protective film is made of a cyclic olefin resin.   It is a manufacturing method of the polarizing plate of any one of Claims 1-5, Comprising: The process of laminating | stacking a protective film on the at least single side | surface of a polarizing film through the said radiation-curable composition, This radiation-curable property A method for producing a polarizing plate comprising a curing step of obtaining a polarizing plate by irradiating the composition with light irradiation.

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