TW201730231A - Polarizing plate - Google Patents

Abstract

An object of the present invention is to provide a polarizing plate which is capable of maintaining optical performance without moving iodine from a polarizing film to other layer such as a protective film or an adhesive film. The polarizing plate of the present invention contains a first cured material layer composed of a cured product of a curable composition having a polymerizable compound and an adhesive film in this order on one surface of a polarizing film having iodine in polyvinyl alcohol, wherein the composition of the polymerizable compound contained in the curable composition, relative to the total amount of 100 mass% of the polymeriable compound, includes: (A1) 35 to 70 mass% of an oxetane compound having two or more oxetanyl groups, (A2) 0 to 40 mass% of an aliphatic epoxy compound having two or more epoxy groups, (A3) 15 to 50 mass% of an alicyclic epoxy compound having two or more epoxy groups, and (A4) 0 to 20 mass% of an aromatic epoxy compound having one or more aromatic rings.

Description

Polarizer

The present invention relates to a polarizing plate, and more specifically to a polarizing plate comprising a cured layer composed of a cured product of a curable composition on one surface of a polarizing film containing iodine. Moreover, the present invention is also applicable to, for example, a curable composition which is a material constituting a polarizing plate and a cured product of the curable composition.

In the conventional image display panel such as a liquid crystal display panel or an organic electroluminescence (organic EL) display panel, the polarizing plate can be used after being attached to an image display element such as a liquid crystal cell or an organic EL element. As such a polarizing plate, it is known that at least one surface of a polarizing film that adsorbs iodine in a polyvinyl alcohol-based resin film is provided, and a transparent protective film and an image display element are adhered via an adhesive. A polarizing plate with a laminated structure. As an adhesive agent used for constituting such a polarizing plate, for example, Patent Document 1 describes an aliphatic epoxy, an alicyclic epoxy, and/or an oxetane, and a photopolymerization initiator. The photo-cation hardening type adhesive (curable composition) and the cured hardened material function as an adhesive.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-063397

However, in the iodine-containing polarizing film, when the protective film is laminated using an adhesive as described in the above-mentioned patent document, iodine contained in the polarizing film is relatively easily transmitted through the adhesive layer. If the iodine completely penetrates the adhesive layer, the optical properties of the polarizing plate are sometimes lowered. The movement of iodine from such a polarizing film is particularly remarkable in a high-temperature and high-humidity environment, and therefore it is sought that the iodine contained in the polarizing film does not face the adhesive layer even in a high-temperature and high-humidity environment. A polarizing plate that moves and maintains optical performance.

An object of the present invention is to provide a polarizing plate in which iodine does not move from a polarizing film toward an adhesive layer and optical performance can be maintained. Further, it is an object of the invention to provide a curable composition which is particularly suitable as a material constituting such a polarizing plate.

The present invention provides the following suitable aspects [1] to [7].

[1] A polarizing plate which is provided on one surface of a polarizing film containing iodine in polyvinyl alcohol, and sequentially includes a first cured layer composed of a cured product containing a curable composition of a polymerizable compound, and an adhesive layer. The composition of the polymerizable compound contained in the curable composition is (O1) an oxygen heterocycle having two or more oxetanyl groups, based on 100% by mass of the total amount of the polymerizable compound. Butane compound 35 (A2) an aliphatic epoxy compound having two or more epoxy groups (0 to 40% by mass), (A3) an alicyclic epoxy compound having two or more epoxy groups, 15 to 50% by mass, And (A4) 0 to 20% by mass of a polarizing plate of an aromatic epoxy compound having one or more aromatic rings.

In the polarizing plate, the composition of the polymerizable compound contained in the curable composition may be 35 to 70% by mass of (A1) an oxetane compound having two or more oxetanyl groups, ( A2) 3 to 40% by mass of the aliphatic epoxy compound having 2 or more epoxy groups, 15 to 50% by mass of the (A3) alicyclic epoxy compound having 2 or more epoxy groups, and (A4) having 1 The aromatic epoxy compound of the above aromatic ring is 0.1 to 20% by mass.

In the polarizing plate, the composition of the polymerizable compound contained in the curable composition may be 35 to 70% by mass of the oxetane compound having two or more oxetanyl groups (A1). (A2) 0% by mass of an aliphatic epoxy compound having two or more epoxy groups; (A3) 15 to 50% by mass of an alicyclic epoxy compound having two or more epoxy groups; (A4) 0% by mass of the aromatic epoxy compound having one or more aromatic rings, and in this case, the content (Wa1) of the oxetane compound having two or more oxetanyl groups with respect to (A1), (A3) The mass ratio (Wa3/Wa1) of the content (Wa3) of the alicyclic epoxy compound having two or more epoxy groups is preferably 0.45 to 1.5.

Further, in the polarizing plate, the composition of the polymerizable compound contained in the curable composition may be 35 to 70% by mass of the oxetane compound having two or more oxetanyl groups (A1). (A2) 0% by mass of an aliphatic epoxy compound having two or more epoxy groups, (A3) 15 to 50% by mass of an alicyclic epoxy compound having two or more epoxy groups, and (A4) having 1 0.1 to 20% by mass of the aromatic epoxy compound of the above aromatic ring, in which case, the content (Wa1) of the oxetane compound having two or more oxetanyl groups relative to (A1), (A3) The mass ratio (Wa3/Wa1) of the content (Wa3) of the alicyclic epoxy compound having two or more epoxy groups is 0.45 to 1.5, and the oxalate having two or more oxetanyl groups relative to (A1) The content (Wa1) of the cyclobutane compound (A4) is preferably from 0.05 to 0.5 by mass (Wa4/Wa1) of the content (Wa4) of the aromatic epoxy compound having one or more aromatic rings.

[2] The polarizing plate according to the above [1], wherein the (A2) aliphatic epoxy compound having two or more epoxy groups is a compound represented by the formula (I): [wherein, Z represents Alkylene groups having 1 to 9 carbon atoms, alkylidene groups having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a formula -C _m H _2m -Z ¹ -C _n H _2n - a divalent group (wherein -Z ¹ - represents -O-, -CO-O-, -O-CO-, -SO ₂ -, -SO- or - CO-, m and n each independently represent an integer of 1 or more, and the total of m and n is 9 or less)]; (A3) an alicyclic epoxy compound having two or more epoxy groups, which is a formula (II) ) the compound shown: In the formula, R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and when the alkyl group has a carbon number of 3 or more, it may have an alicyclic structure; X represents an oxygen atom and a carbon number; The alkanediyl group of 1 to 6 or by the following formulae (IIa) to (IId): Any of the divalent groups shown in the formula (wherein Y ¹ to Y ⁴ each independently represent an alkanediyl group having 1 to 20 carbon atoms, and when the alkanediyl group is a carbon number of 3 or more, may have an alicyclic structure , a and b each independently represent an integer from 0 to 20)].

[3] The polarizing plate according to [1] or [2], wherein the first transparent protective film is provided between the first cured material layer and the adhesive layer.

[4] The polarizing plate according to any one of the above [1], wherein the surface of the polarizing film opposite to the first cured material layer is hardened by a curable composition. A second transparent protective film is provided in the second cured layer formed of the object.

[5] A curable composition comprising a polymerizable compound and a composition comprising a polymerizable compound, and (B) a photocationic polymerization initiator, wherein the amount of the polymerizable compound is 100% by mass based on the total amount of the polymerizable compound The composition of the polymerizable compound is (A1) 35 to 70% by mass of an oxetane compound having two or more oxetanyl groups, and (A2) an aliphatic epoxy compound 0 having two or more epoxy groups. 40% by mass, (A3) 15 to 50% by mass of the alicyclic epoxy compound having two or more epoxy groups, and (A4) 0 to 20% by mass of the aromatic epoxy compound having one or more aromatic rings.

In the curable composition, the composition of the polymerizable compound may be 35 to 70% by mass of the oxetane compound having two or more oxetanyl groups (A1), (A2) 3 to 40% by mass of the aliphatic epoxy compound having 2 or more epoxy groups, 15 to 50% by mass of the alicyclic epoxy compound having 2 or more epoxy groups (A3), and (A4) The aromatic epoxy compound of one or more aromatic rings is 0.1 to 20% by mass.

Further, in the curable composition, the composition of the polymerizable compound may be 35 to 70% by mass of (A1) an oxetane compound having two or more oxetanyl groups, and (A2) having 2 0% by mass of the aliphatic epoxy compound having an epoxy group or more, (A3) 15 to 50% by mass of the alicyclic epoxy compound having 2 or more epoxy groups, and (A4) having a fragrance of one or more aromatic rings 0% by mass of the group epoxy compound. In this case, the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1) and (A3) have two or more epoxy groups. The mass ratio of the alicyclic epoxy compound (Wa3) (Wa3/Wa1) is preferably 0.45 to 1.5.

Further, in the curable composition, the composition of the polymerizable compound may be 35 to 70% by mass of (A1) an oxetane compound having two or more oxetanyl groups, and (A2) having two The above epoxy group-containing aliphatic epoxy compound is 0% by mass, and (A3) is an alicyclic epoxy compound having 15 or more epoxy groups, 15 to 50 5% by weight and (A4) an aromatic epoxy compound having one or more aromatic rings in an amount of 0.1 to 20% by mass, and in this case, an oxetane compound having two or more oxetanyl groups relative to (A1) Content (Wa1), (A3) The mass ratio (Wa3/Wa1) of the content (Wa3) of the alicyclic epoxy compound having two or more epoxy groups is 0.45 to 1.5, and has two or more with respect to (A1) The content (Wa1) of the oxetane compound of the oxetane group (A4), the mass ratio (Wa4/Wa1) of the content (Wa4) of the aromatic epoxy compound having one or more aromatic rings is 0.05 to 0.5 is preferred.

[6] The curable composition according to the above [5], wherein the (A2) aliphatic epoxy compound having two or more epoxy groups is a compound represented by the formula (I): Wherein Z represents an alkylene group having 1 to 9 carbon atoms, an alkylene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a formula -C _m H _2m -Z ¹ -C _n H _2n - The divalent base shown (wherein -Z ¹ - represents -O-, -CO-O-, -O-CO-, -SO ₂ -, -SO- or -CO-, m and n are each independently The above represents an integer of 1 or more, and the total of m and n is 9 or less)]; the alicyclic epoxy compound having two or more epoxy groups in the above (A3) is a compound represented by the formula (II): In the formula, R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and when the alkyl group has 3 or more carbon atoms, it may have an alicyclic structure, and X represents an oxygen atom. An alkanediyl group having 1 to 6 carbon atoms or by the following formulas (IIa) to (IId): Any one of the divalent groups shown in the formula (wherein Y ¹ to Y ⁴ each independently represent an alkanediyl group having 1 to 20 carbon atoms, and when the alkanediyl group is a carbon number of 3 or more, it may have an alicyclic formula The structures, a and b each independently represent an integer from 0 to 20)].

[7] A cured product comprising the curable composition according to the above [5] or [6].

According to the present invention, it is possible to provide a polarizing plate in which iodine does not move from the polarizing film toward the adhesive layer and maintains excellent optical properties. Moreover, it is possible to provide a material which is particularly suitable as a material for such a polarizing plate. The hardening composition of the material.

1‧‧‧ polarizing film

2‧‧‧1st hardened layer

3‧‧‧Adhesive layer

4‧‧‧2nd hardened layer

5‧‧‧2nd transparent protective film

6‧‧‧1st transparent protective film

10‧‧‧Polar plate

X‧‧‧ liquid crystal unit

Fig. 1 is a cross-sectional view showing the structure of an embodiment of a polarizing plate of the present invention.

Fig. 2 is a cross-sectional view showing the structure of one embodiment of the polarizing plate of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. Further, the scope of the present invention is not limited to the embodiments described herein, and various modifications may be made without departing from the scope of the invention.

When the structure of one embodiment of the polarizing plate of the present invention is described with reference to Fig. 1, the polarizing plate (10) of the present invention is provided on one surface of the polarizing film (1) with the first cured layer (2). ) and the structure of the adhesive layer (3). If necessary, a transparent protective film (5) may be provided on the surface opposite to the first cured layer of the polarizing film (1) via the second cured layer (4).

Further, in the polarizing plate of the present invention, the first transparent protective film (6) may be provided between the first cured material layer (2) and the adhesive layer (3). This embodiment is shown in Fig. 2. In the polarizing plate (10), a second transparent protective film may be provided on the surface opposite to the first cured layer of the polarizing film (1), via the second cured layer (4). 5).

The polarizing plate (10) of the present invention is disposed on one surface of the liquid crystal cell (X) via an adhesive layer, and further, a polarizing plate which is the same as or different from the polarizing plate of the present invention is disposed on the liquid crystal cell. On the other surface, a liquid crystal display panel is constructed.

Hereinafter, each structural component of the polarizing plate of the present invention will be described in detail.

[1st hardened layer]

The polarizing plate of the present invention has a first cured layer composed of a cured product of a curable composition on one surface of a polyvinyl alcohol containing a polarizing film of iodine. The curable composition contains (A1) an oxetane compound having two or more oxetanyl rings (oxetane rings) (hereinafter, sometimes referred to as "oxetane compound" A1)") is a polymerizable compound.

The oxetane compound (A1) is a compound having two or more oxetanyl groups in the molecule, and may be an aliphatic compound, an alicyclic compound or an aromatic compound. Examples of the oxetane compound (A1) include, for example, bis1,4-bis[{(3-ethyloxetan-3-yl)methoxy}methyl]benzene. (also known as tolyldioxybutane), bis(3-ethyl-3-oxetanylmethyl)ether, and the like. These oxetane compounds (A1) may be used singly or in combination of different plural kinds. Since the oxetane compound (A1) having two or more oxetanyl groups is contained, a cured product having a high crosslinking density and a high density can be obtained by curing the curable composition. Therefore, by providing the cured layer composed of such a cured product on one surface of the polarizing film, the movement of iodine from the polarizing film can be effectively suppressed. Further, when the adhesive layer contains an ionic compound, when the ionic compound moves toward the polarizing film, the ionic compound acts on the iodine in the polarizing film to lower the optical performance, but the oxetane compound (A1) is contained. The movement of the ionic compound from the adhesive layer toward the polarizing film can be suppressed.

The curable composition may contain (A2) an aliphatic epoxy compound having two or more epoxy groups (hereinafter, sometimes referred to as "aliphatic" The epoxy compound (A2)") may contain the aliphatic epoxy compound (A2) as a polymerizable compound and its content is 0 (zero)% by mass. The aliphatic epoxy compound (A2) is one in which at least two or more compounds are bonded to an epoxy ring bonded to an aliphatic carbon atom. Examples of the aliphatic epoxy compound (A2) include a 2-functional group such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether. The epoxy compound; a trifunctional or higher epoxy compound such as trimethylolpropane triglycidyl ether or neopentyltetraethylene tetraglycidyl ether.

When the aliphatic epoxy compound (A2) is contained, the oxirane ring bonded to the aliphatic carbon atom has two functions in the molecule from the viewpoint of the adhesion between the polarizing film and the transparent protective film. An epoxy compound (also referred to as an aliphatic diepoxy compound) is preferred, and an aliphatic diepoxy compound represented by the following formula (I) is more preferable. In particular, an aliphatic diepoxy compound represented by the following formula (I) containing the curable composition as the aliphatic epoxy compound (A2) can provide a curable composition having low viscosity and easy coating.

In the formula (I), Z represents an alkylene group having 1 to 9 carbon atoms, an alkylene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a formula -C _m H _2m -Z ¹ -C _n H _2n - a divalent group as shown. Further, in the above formula -C _m H _2m -Z ¹ -C _n H _2n -, -Z ¹ - represents -O-, -CO-O-, -O-CO-, -SO ₂ -, -SO- or -CO-, m and n each independently represent an integer of 1 or more, and the total of m and n is 9 or less.

The divalent alicyclic hydrocarbon group may be a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, and examples thereof include a divalent residue represented by the following formula (I-1).

Specific examples of the compound represented by the formula (I) include diglycidyl ether of an alkane diol, diglycidyl ether of an oligomeric alkyl diol of about 4 or more, or an alicyclic type II. A diglycidyl ether of an alcohol or the like.

Examples of the glycol which can form the compound represented by the above formula (I) include ethylene glycol, propylene glycol, 1,3-propanediol, and 2-methyl-1,3-propanediol. , 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2, 4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl Base-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl An alkane diol such as benzyl-1,8-octanediol or 1,9-decane diol; or an oligoalkylene group of diethylene glycol, triethylene glycol, tetraethylene glycol or dipropylene glycol An alicyclic diol such as an alcohol; cyclohexane diol or cyclohexane dimethanol.

In the present invention, the aliphatic epoxy compound (A2) is 1,4-butanediol diglycidyl ether from the viewpoint of being a curable composition which is low in viscosity and easy to apply. 6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether is preferred. In the point of maintaining optical performance, 1,6-hexanediol diglycidyl ether, cyclohexane dimethanol diminute Glycerol ether, neopentyl alcohol polyglycidyl ether is preferred. As the aliphatic epoxy compound (A2), one type of aliphatic epoxy compound may be used alone, or a plurality of different types may be used in combination.

The curable composition contains an alicyclic epoxy compound having two or more epoxy groups (hereinafter referred to as "alicyclic epoxy compound (A3)") as the polymerizable compound (A3). When the alicyclic epoxy compound (A3) is contained, the cured layer after the curable composition is cured has a high modulus of elasticity, and cracking of the polarizing film due to heat shrinkage can be suppressed.

The alicyclic epoxy compound (A3) is a compound having two or more epoxy groups bonded to the alicyclic ring in the molecule. "The epoxy group bonded to the alicyclic ring" means the following formula (a): The oxygen atom -O- crosslinked in the structure shown. In the above formula (a), m is an integer of 2 to 5.

In the above formula (a), two or more compounds in the form of one or more hydrogen atoms in (CH ₂ ) _m are bonded to a compound having another chemical structure, and the alicyclic epoxy compound (A3) can be obtained. . One or a plurality of hydrogen atoms in (CH ₂ ) _m may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group.

Among them, the cured material has a high glass transition temperature, and has an epoxycyclopentane structure from the viewpoint of excellent adhesion between the polarizing film and the transparent protective film [m=3 in the above formula (a)] Or epoxy cyclohexane structure The alicyclic epoxy compound of [m=4 in the above formula (a)] is more preferable, and the alicyclic diepoxy compound represented by the following formula (II) is more preferable. In particular, the alicyclic diepoxide compound represented by the following formula (II) is contained in the curable composition as the compound (A3), and the cured layer of the curable composition is cured to have high elasticity. Also, cracking due to thermal contraction of the polarizing film can be suppressed.

In the formula (II), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and when the alkyl group has a carbon number of 3 or more, it may have an alicyclic structure. The alkyl group having 1 to 6 carbon atoms may be a linear or branched alkyl group, and examples of the alkyl group having an alicyclic structure include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and the like.

In the formula (II), an X-based oxygen atom, an alkanediyl group having 1 to 6 carbon atoms or the following formulas (IIa) to (IId):

The base of two valencies shown in either of them.

Examples of the alkanediyl group having 1 to 6 carbon atoms include a methylene group and a sub Ethyl, propane-1,2-diyl and the like.

When X in the formula (II) is a divalent group represented by any one of the above formulae (IIa) to (IId), Y ¹ to Y ^{4 in} each formula are each independently a carbon number of 1 to 20 The alkanediyl group may have an alicyclic structure when the alkanediyl group has a carbon number of 3 or more.

a and b each independently represent an integer of 0 to 20.

The compound represented by the formula (II) may, for example, be a compound of the following A to G. Further, the chemical formulae A to G shown later correspond to the compounds A to G, respectively.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate

B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate

C: ethylene bis(3,4-epoxycyclohexanecarboxylate)

D: bis(3,4-epoxycyclohexylmethyl) adipate

E: bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate

F: diethylene glycol bis(3,4-epoxycyclohexylmethyl ether)

G: ethylene glycol bis(3,4-epoxycyclohexylmethyl ether)

In the present invention, as the alicyclic epoxy compound (A3), 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate is used from the viewpoint of easy availability. Better. As the alicyclic epoxy compound (A3), one type of alicyclic epoxy compound may be used alone or in combination of plural kinds.

The curable composition may contain (A4) an aromatic epoxy compound having one or more aromatic rings (hereinafter, sometimes referred to as "aromatic The epoxy compound (A4)") may not contain the aromatic epoxy compound (A4) as a polymerizable compound, and its content may be 0 (zero)% by mass. When the aromatic epoxy compound (A4) is contained, the curable composition is a hydrophobic resin, and the obtained cured layer is also rendered hydrophobic. Therefore, it is possible to prevent intrusion of moisture from the outside under high temperature and high humidity, and it is possible to effectively suppress the movement of iodine contained in the polarizing film.

The aromatic epoxy compound (A4) is a compound having one or more aromatic rings in the molecule, and specific examples thereof include the following compounds.

a monovalent phenol having at least one aromatic ring of phenol, cresol, butyl phenol or the like, or a mono/polyglycidyl etherate of the epoxide adduct, such as bisphenol A, bisphenol F, or a glycidyl etherate or an epoxy novolac resin which further adds an epoxide compound; a shrinkage of an aromatic compound having two or more phenolic hydroxyl groups such as resorcin or hydroquinone or catechol Mono/polyglycidyl etherate of an aromatic compound having two or more alcoholic hydroxyl groups such as phenylenediethanol, benzenediethanol or phenylbutanol; phthalic acid, terephthalic acid, and benzotriene a glycidyl ester of a polybasic acid aromatic compound having two or more carboxylic acids such as an acid; a glycidyl ester of benzoic acid such as benzoic acid or benzoic acid or naphthoic acid; or an epoxide of styrene oxide or divinylbenzene; Wait.

When the aromatic epoxy compound (A4) is contained, from the viewpoint of low viscosity of the curable composition, it is preferred to contain a compound selected from the group consisting of phenols. Glycidyl ether, glycidyl ether compound of an aromatic compound having two or more alcoholic hydroxyl groups, glycidyl ether compound of polyvalent phenol, glycidyl ester of benzoic acid, glycidyl ester of polybasic acid, styrene oxide Or at least one of the group consisting of epoxides of divinylbenzene.

Moreover, in order to improve the hardenability of the curable composition, the aromatic epoxy compound (A4) is preferably an epoxy group equivalent of from 80 to 500.

As the aromatic epoxy compound (A4), one type of aromatic epoxy compound may be used alone, or a plurality of different types may be used in combination.

A commercially available product can be used as the aromatic epoxy compound (A4), and examples thereof include Denacol EX-121, Denacol EX-141, Denacol EX-142, Denacol EX-145, Denacol EX-146, and Denacol EX-147. , Denacol EX-201, Denacol EX-203, Denacol EX-711, Denacol EX-721, On Court EX-1020, On Court EX-1030, On Court EX-1040, On Court EX-1050, On Court EX-1051 On Court EX-1010, On Court EX-1011, On Court EX-1012 (above, Nagasechemtex); OGSOL PG-100, OGSOL EG-200, OGSOL EG-210, OGSOLEG-250 (above, manufactured by Osaka Gas Chemical Co., Ltd.); HP4032, HP4032D, HP4700 (above, manufactured by Nippon DIC Co., Ltd.); ESN-475V (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.); Epikote YX8800 (manufactured by Mitsubishi Chemical Corporation); MARPROOF G- 0105 SA, MARPROOF G-0130 SP (manufactured by NOF Corporation); EPICLON N-665, EPICLON HP-7200 (above, DIC); EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, XD- 1000, NC-3000, EPPN-501H, EPPN-501HY, EPPN-502H, NC-7000L (above, AKKA Glycyrol ED-501, ADEKA Glycyrol ED-502, ADEKA Glycyrol ED-509, ADEKA Glycyrol ED-529, ADEKA RESIN EP-4000, ADEKA RESIN EP-4005, ADEKA RESIN EP-4100, ADEKA RESIN EP-4901 (manufactured by ADEKA CORPORATION); TECHMORE VG-3101L, EPOX-MKR 710, EPOX-MKR 151 (above, manufactured by Printec), and the like.

The content of the polymerizable compounds (A1) to (A4) in the curable composition is 100% by mass based on the total amount of the total polymerizable compound contained in the curable composition, and is (A1) 35 to 70% by mass. (A2) 0 to 40% by mass, (A3) 15 to 50% by mass, and (A4) 0 to 20% by mass.

In one embodiment of the present invention, the content of the polymerizable compounds (A1) to (A4) may be (A1) 35 to (100% by mass) based on the total amount of the total polymerizable compound contained in the curable composition. 70% by mass, (A2) 3 to 40% by mass, (A3) 15 to 50% by mass, (A4) 0.1 to 20% by mass, preferably (A1) 45 to 55% by mass, (A2) 10 to 25% by mass %, (A3) 25 to 35 mass%, (A4) 0.1 to 20% by mass. When the content of the oxetane compound (A1) is within the above range, a dense cured layer can be easily formed. When the content of the aliphatic epoxy compound (A2) is within the above range, the viscosity of the curable composition is low, and a composition which can be easily applied can be obtained. When the content of the alicyclic epoxy compound (A3) is within the above range, it can be rapidly cured by irradiation with an active energy ray such as ultraviolet rays, and a cured layer having sufficient hardness can be easily formed. When the content of the aromatic epoxy compound (A4) is within the above range, the cured layer becomes hydrophobic and becomes a cured layer in which iodine is hard to permeate.

Furthermore, in another embodiment of the present invention, the content of the polymerizable compounds (A1) to (A4) in the curable composition is 100% based on the total amount of the total polymerizable compound contained in the curable composition. The mass % may be (A1) 35 to 70% by mass, (A2) 0% by mass, (A3) 15 to 50% by mass, and (A4) 0% by mass.

In this case, the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1), and the content of the alicyclic epoxy compound having two or more epoxy groups (A3) The mass ratio (Wa3/Wa1) of (Wa3) is preferably 0.45 to 1.5, more preferably 0.6 to 1.25. When the mass ratio of the content of the oxetane compound (A1) to the alicyclic epoxy compound (A3) is within the above range, by curing the curable composition, the crosslinking density is high, and denser hardening can be obtained. Things.

Furthermore, in another embodiment of the present invention, the content of the polymerizable compounds (A1) to (A4) in the curable composition is 100% of the total amount of the total polymerizable compound contained in the curable composition. The mass % may also be: (A1) 35 to 70% by mass, (A2) 0% by mass, (A3) 15 to 50% by mass, and (A4) 0.1 to 20% by mass.

In this case, the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1), and the content of the alicyclic epoxy compound having two or more epoxy groups (A3) The mass ratio (Wa3/Wa1) of (Wa3) is preferably 0.45 to 1.5, more preferably 0.6 to 1.25. Further, the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1), and the content of the aromatic epoxy compound having one or more aromatic rings (A4) (Wa4) The mass ratio (Wa4/Wa1) is preferably from 0.05 to 0.5, more preferably from 0.1 to 0.45. When the mass ratio of the content of the oxetane compound (A1) to the alicyclic epoxy compound (A3) is within the above range, by curing the curable composition, the crosslinking density is high, and denser hardening can be obtained. When the mass ratio of the content of the oxetane compound (A1) to the aromatic epoxy compound (A4) is within the above range, a hydrophobic resin can be obtained by curing the curable composition.

The curable composition may contain a polymerizable compound different from the above (A1) to (A4) as a polymerizable compound. In the present invention, as the polymerizable compound which can be contained in the curable composition, as long as it is available As the effect of the present invention, a known polymerizable compound can be used.

Examples of such a polymerizable compound include an aliphatic monoepoxy compound and an alicyclic monoepoxy compound.

When the curable composition contains a polymerizable compound different from the above (A1) to (A4) as a polymerizable compound, the content thereof is 100% by mass based on the total amount of the total polymerizable compound contained in the curable composition. It is preferably 10% by mass or less, more preferably 5% by mass or less.

In one embodiment of the present invention, the curable composition does not contain the polymerizable compound different from the above (A1) to (A4), and the content thereof is 0% by mass.

The aforementioned hardenable composition usually contains a polymerization initiator for initiating polymerization. As the polymerization initiator, for example, a photocationic polymerization initiator (B) can be mentioned. The photocationic polymerization initiator is a polymerization initiator which initiates a cationically polymerizable compound by irradiation with an active energy ray such as visible light, ultraviolet light, X-ray, or electron beam to generate a cationic species or a Lewis acid. The photocationic polymerization initiator has excellent storage stability and workability even when it is mixed in a polymerizable compound because it acts as a photocatalyst. Examples of the compound which generates a cationic species or a Lewis acid by irradiation with an active energy ray include an onium salt of an aromatic onium salt or an aromatic onium salt, an aromatic diazonium salt, an iron-aromatic hydrocarbon complex, and the like.

The aromatic onium salt is a compound having a diarylsulfonium cation, and as the cation, a diphenylphosphonium cation is typically exemplified.

The aromatic onium salt is a compound having a triarylsulfonium cation, and as the cation, typically, for example, a triphenylphosphonium cation or a 4,4'-double (two) Phenylhydrazine) diphenyl sulfide cations and the like. The aromatic diazonium salt is a compound having a diazonium cation, and as the cation, a benzene diazonium cation is typically exemplified. Further, the iron-aromatic complex is typically a cyclopentadienyl iron (II) arene cation complex.

The cation shown above is paired with an anion to form a photocationic polymerization initiator. Examples of the anion constituting the photocationic polymerization initiator include a specific phosphorus anion [(Rf) _n PF _6-n ] ^- , a hexafluorophosphate anion PF ₆ ^- , a hexafluoroantimonate anion SbF ₆ ^- , and Fluorohydroxy decanoate anion SbF ₅ (OH) ^- , hexafluoroarsenate anion AsF ₆ ^- , tetrafluoroborate anion BF ₄ ^- , quinone (pentafluorophenyl) borate anion B (C ₆ F ₅ ) ₄ ^- Wait. Among them, the photocationic polymerization initiator is a special phosphorus anion [(Rf) _n PF _6-n ] ^- , hexafluorofluoride from the viewpoint of the curability of the polymerizable compound and the safety of the obtained cured layer. Phosphate anion PF ₆ ^{- is} preferred.

The photocationic polymerization initiator may be used singly or in combination of a plurality of different types. Among them, the aromatic onium salt has ultraviolet absorbing properties even in a wavelength region of around 300 nm, and therefore has excellent curability and can produce a cured product having good mechanical strength or adhesion strength, which is preferable.

The content of the photocationic polymerization initiator in the curable composition is usually 0.5 to 10 parts by mass, preferably 6 parts by mass or less, based on 100 parts by mass of the polymerizable compound. When the content of the photocationic polymerization initiator is within the above range, the polymerizable compound can be sufficiently cured, so that a high mechanical strength or a bonding strength can be imparted to the cured layer composed of the obtained cured product. On the other hand, when the amount is too large, it starts from photocationic polymerization. The product of the initiator is reacted with the hydroxyl group of the polyvinyl alcohol constituting the polarizing film, and the optical property of the polarizing film is lowered.

In the present invention, the curable composition may contain a general additive used in the curable composition as necessary. Examples of such an additive include an ion trapping agent, an antioxidant, a chain shifting agent, a polymerization accelerator (polyol, etc.), a sensitizer, a sensitizing aid, a light stabilizer, a tackifier, and a thermoplastic resin. , fillers, flow regulators, plasticizers, defoamers, leveling agents, decane coupling agents, pigments, antistatic agents, UV absorbers, etc.

As a sensitizer, a photo sensitizer is mentioned, for example. The photosensitizer is a compound which exhibits a maximum absorption at a wavelength longer than the maximum absorption wavelength shown by the photocationic polymerization initiator (B), and which promotes the polymerization initiation reaction by the photocationic polymerization initiator (B). Further, the photosensitizing agent is a compound which further promotes the action of the photosensitizer. Depending on the type of the transparent protective film, it is preferred to blend such a light sensitizer to further adjust the light sensitizing aid.

The photosensitizer is, for example, preferably a compound which exhibits a maximum absorption of light at a wavelength longer than 380 nm. The photocationic polymerization initiator (B) described above exhibits a maximum absorption at a wavelength of around 300 nm or shorter, and a light of a wavelength near this is induced to generate a cationic species or a Lewis acid, and the starting polymerizable compound (A1) Cationic polymerization to (A4), but if such a photosensitizer is formulated, light having a longer wavelength than this, especially a wavelength longer than 380 nm, is also induced. As such a photosensitizer, the lanthanoid compound can be advantageously used. When a specific example of a quinone-based light sensitizer is listed, the following compounds are mentioned.

9,10-Dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diisopropoxyanthracene, 9,10-dibutoxyanthracene 9,10-dipentyloxy fluorene, 9,10-dihexyloxyindole, 9,10-bis(2-methoxyethoxy)anthracene, 9,10-bis(2-ethoxyethoxy)蒽, 9,10-bis(2-butoxyethoxy)anthracene, 9,10-bis(3-butoxypropoxy)anthracene, 2-methyl- or 2-ethyl-9 , 10-dimethoxyanthracene, 2-methyl- or 2-ethyl-9,10-diethoxyanthracene, 2-methyl- or 2-ethyl-9,10-dipropoxyfluorene , 2-methyl- or 2-ethyl-9,10-diisopropoxy oxime, 2-methyl- or 2-ethyl-9,10-dibutoxyanthracene, 2-methyl- or 2-ethyl-9,10-dipentyloxy fluorene, 2-methyl- or 2-ethyl-9,10-dihexyloxyanthracene, and the like.

In the polarizing plate of the present invention, the first cured layer is, for example, a polymerizable compound (A1) to (A4) and a photocationic polymerization initiator, and if necessary, a polymerizable compound other than (A1) to (A4) is mixed. And the curable composition obtained by the additive is applied to the polarizing film, or when the first transparent protective film is used, it is applied onto the first transparent protective film, and is coated by irradiating an active energy ray such as an ultraviolet ray or an electron beam. The hardening composition of the cloth hardens and forms to make.

When the active energy ray is irradiated to the layer composed of the curable composition, a cationic species or a Lewis acid is produced from the photocationic polymerization initiator. By the cationic species or the Lewis acid, polymerization of the polymerizable compound is carried out after the irradiation of the active energy ray, whereby the curable composition is cured to form a cured layer.

In the polarizing plate of the present invention, the thickness of the first cured layer is not particularly limited, but is preferably in the range of 0.5 to 20 μm, more preferably in the range of 1 to 10 μm. The thickness of the first cured layer is usually 0.5 μm or more from the viewpoint of effectively suppressing the movement of iodine. Further, the curable composition can be sufficiently cured, and is usually 20 μm or less.

The polarizing plate of the present invention is provided between the polarizing film and the adhesive layer, or between the polarizing film and the transparent protective film, and has a hardening composition containing the polymerizable compounds (A1) to (A4). The first cured layer formed of the object can prevent the iodine contained in the polarizing film from moving toward the adhesive layer or the transparent protective film. In particular, in a high-temperature and high-humidity environment, the intrusion of moisture from the outside accelerates the movement of iodine, but this effect can be effectively suppressed in the polarizing plate of the present invention (that is, the durability is excellent). Therefore, the polarizing plate of the present invention can maintain optical properties.

In addition, when an ionic compound which is an antistatic agent or the like is contained, for example, the ionic compound present in the adhesive layer passes through the transparent protective film or the adhesive layer constituting the polarizing plate, and moves toward the polarizing film. It causes interaction with iodine in the polarizing film to lower the optical properties of the polarizing plate. The polarizing plate of the present invention has a polarizing film and a sticky layer Since the first cured layer composed of the cured product of the curable composition described above is formed between the layers, the movement of the ionic compound from the adhesive layer can be suppressed, whereby the deterioration of the optical performance of the polarizing plate can be suppressed.

Further, the first cured layer also functions as an adhesive layer that follows the polarizing film and the transparent protective film.

[adhesive layer]

The adhesive constituting the adhesive layer is not particularly limited, and conventionally known adhesives can be used. For example, base polymerization using an acrylic, rubber, polyurethane, organic oxime, polyvinyl ether or the like can be used. Adhesive of matter. Further, it may be an energy ray-curable adhesive or a thermosetting adhesive. Among these, an acrylic resin excellent in transparency, adhesion, reworkability, weather resistance, heat resistance, and the like is suitable as an adhesive for the base polymer.

In the case where the adhesive layer contains an acrylic resin in the present invention, the acrylic resin is not particularly limited, and a conventional one may be used. However, in the polarizing plate of the present invention, from the viewpoint of adhesion and reworkability. The adhesive layer to be contained preferably contains the following acrylic resin (P).

The acrylic resin (P) is represented by the following formula (III): [wherein, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group having 1 to 14 carbon atoms which may be substituted by an alkoxy group having 1 to 10 carbon atoms. The structural unit derived from the alkyl (meth)acrylate (P1) is contained as a main component, and further contains an unsaturated monomer (P2) derived from a polar functional group (hereinafter, sometimes referred to as "containing An acrylic resin of a structural unit of a monomer having a polar functional group.

Here, in the present specification, (meth)acrylic means any of acrylic acid or methacrylic acid, and "(meth)" at the time of (meth)acrylate or the like has the same meaning.

In the above formula (III) which is an alkyl (meth)acrylate (P1) which is a main structural unit of the acrylic resin (P), R ₁ is a hydrogen atom or a methyl group, and R ₂ is an alkyl group having 1 to 14 carbon atoms. . The alkyl group represented by R ₂ may be substituted with a hydrogen atom of 1 to 10 carbon atoms in each group.

Among the alkyl (meth)acrylates (P1) represented by the formula (III), examples of the R _{2 being an} unsubstituted alkyl group include methyl acrylate, ethyl acrylate, and propyl acrylate. a linear alkyl acrylate such as n-butyl acrylate, n-octyl acrylate, or lauryl acrylate; a branched alkyl acrylate such as isobutyl acrylate, 2-ethylhexyl acrylate, or isooctyl acrylate; a linear alkyl methacrylate such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, and lauryl methacrylate; A branched alkyl methacrylate such as isobutyl acrylate, 2-ethylhexyl methacrylate, or isooctyl methacrylate. Among these, n-butyl acrylate is preferable, and specifically, n-butyl acrylate is preferably 50% by mass or more based on the total amount of all monomers constituting the acrylic resin (P).

When an alkyl group in which R ₂ is substituted by an alkoxy group, that is, an alkoxyalkyl group, as the alkyl (meth)acrylate represented by the formula (III), specifically, 2-methoxy acrylate can be exemplified. Ethyl ethyl ester, ethoxymethyl acrylate, 2-methoxyethyl methacrylate, ethoxymethyl methacrylate, and the like.

These alkyl (meth)acrylates (P1) may be used singly or in combination of plural kinds.

In the polar functional group-containing monomer (P2), the polar functional group may be a heterocyclic group such as a free carboxyl group, a hydroxyl group, an amine group or an epoxy ring. The monomer having a polar functional group is preferably a (meth)acrylic compound having a polar functional group. Examples of the examples include unsaturated monomers having a free carboxyl group such as acrylic acid, methacrylic acid, and β-carboxyethyl acrylate; 2-hydroxyethyl (meth)acrylate and (meth)acrylic acid 2 -hydroxypropyl ester, 2- or 3-chloro-2-hydroxypropyl (meth)acrylate, and unsaturated monomer having a hydroxyl group such as diethylene glycol mono(meth)acrylate; acryloylmorpholine, Vinyl caprolactam, N-vinyl-2-pyrrolidone, tetrahydrofurfuryl (meth) acrylate, caprolactone modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, and unsaturated monomer having a heterocyclic group such as 2,5-dihydrofuran; N,N-dimethylaminoethyl (A) An unsaturated monomer or the like having an amine group different from a hetero ring such as an acrylate. The polar functional group is preferably a free carboxyl group, a hydroxyl group, an amine group or an epoxy ring. These polar functional group-containing monomers may also be used singly or in combination of plural kinds.

Among these, it is preferred to contain an unsaturated monomer having a hydroxyl group as one of the polar functional group-containing monomers (P2) constituting the acrylic resin (P). Further, in addition to the unsaturated monomer having a hydroxyl group, an unsaturated monomer having other polar functional groups, such as a free carboxyl group, is used in combination. Unsaturated monomers are also effective.

In the acrylic resin (P), the structural unit derived from the alkyl (meth)acrylate (P1) represented by the above formula (III) is based on the total amount of all monomers constituting the acrylic resin (P). It is preferably 80 to 96% by mass, more preferably 82% by mass or more, and still more preferably 94% by mass or less. The structural unit derived from the polar functional group-containing monomer (P2) is preferably 0.1 to 5% by mass, more preferably 0.5% by mass or more, based on the total amount of the all monomers constituting the acrylic resin (P). Preferably, it is 3 mass% or less.

In the polarizing plate of the present invention, the acrylic resin (P) constituting the adhesive layer may contain the alkyl (meth)acrylate (P1) represented by the above formula (III) and derived from and containing a polar functional group. A structural unit of a different monomer of the monomer (P2). Examples of such an example include an unsaturated monomer (P3) derived from one olefinic double bond and at least one aromatic ring in the molecule (hereinafter sometimes referred to as "a single ring containing an aromatic ring" a structural unit derived from a molecule, a structural unit derived from a (meth) acrylate having an alicyclic structure in a molecule, a structural unit derived from a styrene monomer, and a structure derived from a vinyl monomer The unit is derived from a structural unit of a monomer having a plurality of (meth) acrylonitrile groups in the molecule.

An unsaturated monomer (an aromatic ring-containing monomer) (P3) having one olefinic double bond and at least one aromatic ring in the molecule, having a (meth) acrylonitrile group as an olefinic double bond The basis is better. As such an example, a benzyl (meth) acrylate, a neopentyl glycol benzoate (meth) acrylate, etc. are mentioned, in Formula (IV): [wherein, R ₃ represents a hydrogen atom or a methyl group, n is an integer of 1 to 8, and R ₄ represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group] and an aromatic ring-containing (meth)acrylic acid is represented. The compound is preferred.

In the above formula (IV) which represents a (meth)acrylic compound containing an aromatic ring, when R ₄ is an alkyl group, when the number of carbon atoms is from 1 to 9, and the same is an aralkyl group, the carbon number is from 7 to 11, when it is an aryl group, its carbon number may be 6 to 10. Examples of the alkyl group having 1 to 9 carbon atoms include a methyl group, a butyl group, and a decyl group. Examples of the aralkyl group having 7 to 11 carbon atoms include a benzyl group, a phenethyl group, and a naphthylmethyl group. Further, examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a tolyl group, and a naphthyl group.

Specific examples of the (meth)acrylic compound containing an aromatic ring of the formula (IV) include 2-phenoxyethyl (meth)acrylate and 2-(2-phenoxyethoxy) (meth)acrylate. Ethyl ester, ethylene oxide modified (meth) acrylate of nonylphenol, 2-(o-phenylphenoxy)ethyl (meth)acrylate, and the like. These aromatic ring-containing monomers may be used singly or in combination of different plural kinds. Among these, in 2-phenoxyethyl (meth)acrylate [in the above formula (IV), a compound of R ₄ =H, n = 1], 2-(o-phenyl) (meth)acrylate Phenoxy)ethyl ester [in the above formula (IV), R ₄ =o-phenyl, a compound of n=1], or 2-(2-phenoxyethoxy)ethyl (meth)acrylate [In the above formula (IV), the compound of R ₄ =H, n=2] is suitably used as one of the aromatic ring-containing monomers (P3) constituting the acrylic resin (P).

The alicyclic structure means a cycloalkane structure having a carbon number of usually 5 or more, preferably 5 to 7. Specific examples of the acrylate having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, and trimethyl acrylate. Cyclohexyl ester, tertiary butylcyclohexyl acrylate, cyclohexyl α-ethoxy acrylate, cyclohexyl phenyl acrylate, etc., and specific examples of the methacrylate having an alicyclic structure include methyl Isobornyl acrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, cyclododecyl methacrylate, methylcyclohexyl methacrylate, trimethylcyclohexyl methacrylate, A Tertiary butyl cyclohexyl acrylate, cyclohexyl phenyl methacrylate, and the like.

Specific examples of the styrene-based monomer include, in addition to styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, and triethyl. Alkyl styrenes such as styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene; fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene And halogenated styrene such as iodine styrene; further, nitrostyrene, ethyl styrene styrene, methoxy styrene, divinyl benzene, and the like.

Specific examples of the vinyl monomer include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl fatty acid vinyl ester; vinyl chloride; Or a halogenated ethylene such as ethylene bromide; a vinylidene halide such as vinylidene chloride; a nitrogen-containing aromatic compound such as vinyl pyridine, vinyl pyrrolidone or vinyl carbazole; Ethylene; conjugated diene monomer such as butadiene, isoprene, and chloroprene; and acrylonitrile, methacrylonitrile, and the like.

Specific examples of the monomer having a plurality of (meth) acrylonitrile groups in the molecule include 1,4-butanediol di(meth)acrylate and 1,6-hexanediol II ( Methyl) acrylate, 1,9-decanediol di(meth) acrylate, ethylene glycol di(meth) acrylate, diethylene glycol di(meth) acrylate, tetraethylene glycol (Meth) acrylate, tripropylene glycol di(meth) acrylate, etc., having two (meth) acrylonitrile groups in the molecule; trimethylolpropane tri(meth) acrylate, etc. in the molecule A monomer having three (meth) acrylonitrile groups therein.

The monomer different from the (meth)acrylic acid alkyl ester (P1) and the polar functional group-containing monomer (P2) represented by the formula (III) may be used alone or in combination of two or more. In the case of the adhesive, in the acrylic resin (P), the alkyl (meth)acrylate (P1) and the polar functional group-containing monomer (P2) are structural units of different monomers. It is usually contained in an amount of from 0 to 20 parts by mass, preferably from 0 to 10 parts by mass, based on 100 parts by mass of the nonvolatile matter of the resin.

The resin component constituting the adhesive composition may contain two or more kinds of the (meth)acrylic acid alkyl ester (P1) derived from the above formula (III) and the polar functional group-containing monomer (P2). The structural unit of the acrylic resin. Further, in the acrylic resin (P), an acrylic resin different therefrom may be mixed, for example, an acrylic acid having a structural unit derived from an alkyl (meth)acrylate of the formula (III) and containing no polar functional group. Used as a resin or the like. Containing alkyl (meth)acrylate (P1) derived from formula (III) The acrylic resin (P) having a structural unit of the monomer (P2) having a polar functional group is preferably 80% by mass or more, and more preferably 90% by mass or more based on the total amount of the acrylic resin (P).

An acrylic resin (P) containing an interpolymer of a monomer mixture of a (meth)acrylic acid alkyl ester (P1) represented by the formula (III) and a monomer having a polar functional group (P2), preferably by The standard polystyrene-equivalent weight average molecular weight Mw of the gel permeation chromatography (GPC) is in the range of 1,000,000 to 2,000,000. When the weight average molecular weight in terms of the standard polystyrene is within the above range, the adhesion under high temperature and high humidity is increased, and the possibility of peeling or floating between the liquid crystal cell and the adhesive layer tends to be low, and it is reworked. Sex has a tendency to improve. Further, even if the size of the polarizing plate attached to the adhesive layer changes, the adhesive layer easily changes in accordance with the dimensional change thereof, and there is no difference between the brightness of the peripheral portion of the liquid crystal cell and the brightness of the central portion. The tendency to suppress white spots or uneven color.

The ratio of the weight average molecular weight Mw to the number average molecular weight Mn is preferably in the range of 3 to 7 in terms of the molecular weight distribution represented by Mw/Mn. When the molecular weight distribution Mw/Mn is in the range of 3 to 7, the liquid crystal display panel or the liquid crystal display device can suppress the occurrence of poor white spots or the like even when exposed to a high temperature.

Further, the acrylic resin (P) preferably has a glass transition temperature of from -10 to -60 ° C from the viewpoint of exhibiting adhesion. The glass transition temperature of the resin can generally be determined by a differential scanning calorimeter.

The acrylic resin (P) constituting the adhesive composition can be, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, or a suspension polymerization method. It is manufactured by various methods such as the law. In the production of the acrylic resin, a polymerization initiator can usually be used. The content of the polymerization initiator is preferably 0.001 to 5 parts by mass based on 100 parts by mass of the total of all monomers used in the production of the acrylic resin.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, or the like can be used. The photopolymerization initiator may, for example, be 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl) ketone or the like. As the thermal polymerization initiator, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis ( Cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methyl Azo such as oxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), and 2,2'-azobis(2-hydroxymethylpropionitrile) Compound; lauryl peroxide, tertiary butyl hydroperoxide, benzammonium peroxide, tertiary butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarboxylic acid Ester, dipropyl peroxydicarboxylate, tertiary butyl peroxy neodecanoate, tertiary butyl peroxypivalate, and (3,5,5-trimethylhexyl) An organic peroxide such as an oxide; an inorganic peroxide such as potassium persulfate, ammonium persulfate or hydrogen peroxide. Further, a redox initiator such as a peroxide and a reducing agent may be used in combination as a polymerization initiator.

As a method for producing the acrylic resin (P), a solution polymerization method is particularly preferred. Specific examples of the solution polymerization method and description thereof include mixing a desired monomer and an organic solvent, adding a thermal polymerization initiator under a nitrogen atmosphere, and stirring at 40 to 90 ° C, preferably 50 to 80 ° C. 3 to 10 hours method. Also, in order to control the reaction, continuously in the polymerization The monomer or the thermal polymerization initiator may be added intermittently or may be added in a state of being dissolved in an organic solvent. Here, as the organic solvent, for example, an aromatic hydrocarbon such as toluene or xylene; an ester such as ethyl acetate or butyl acetate; an aliphatic alcohol such as propanol or isopropanol; acetone or A can be used. Ketoether, ketones such as methyl isobutyl ketone, and the like.

The adhesive layer contained in the polarizing plate of the present invention is preferably composed of an acrylic resin (P) and a crosslinking agent. As a crosslinking agent which can be used, for example, a compound which reacts with a structural unit derived from a monomer (P2) containing a polar functional group in an acrylic resin (P) to crosslink an acrylic resin. Specific examples thereof include a cyanate ester compound, an epoxy compound, an aziridine compound, and a metal chelate compound. Among these, the isocyanate compound, the epoxy compound, and the aziridine compound have at least two functional groups capable of reacting with a polar functional group in the acrylic resin (P) in the molecule.

The isocyanate compound is a compound having at least two isocyanato groups (-NCO) in the molecule, and examples thereof include toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and Xylyl isocyanate, xylyl hydrogen diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and the like. Further, an adduct of these isocyanate compounds and a polyol such as glycerin or trimethylolpropane, or an isocyanate compound may be used as a dimer or a trimer. Crosslinker. Two or more kinds of isocyanate compounds may be mixed and used.

The epoxy compound is a compound having at least two epoxy groups in the molecule, and examples thereof include a bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, and polyethylene glycol diglycidyl ether. Glycerol diglycidyl ether, glycerol triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N-diglycidylaniline, N,N,N ', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, and the like. Two or more epoxy compounds may be mixed and used.

The aziridine compound is a compound having at least two 3-membered ring skeletons composed of one nitrogen atom and two carbon atoms of ethyleneimine in the molecule, and examples thereof include diphenylmethane. -4,4'-bis(1-aziridinecarboxamide), toluene-2,4-bis(1-aziridinecarboxamide), triethylene melamine, isophthalic acid bis- -1- (2-methylaziridine), gin-1-aziridine phosphine oxide, hexamethylene-1,6-bis(1-aziridinecarboxamide), trimethylolpropane ginseng-β - aziridine propionate, tetramethylolmethane-β-aziridine propionate, and the like.

Examples of the metal chelate compound include polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, ruthenium, magnesium, vanadium, chromium, and zirconium, and acetonitrile or ethyl bromide. a compound in which thioglycolate is coordinated, and the like.

Among these crosslinking agents, isocyanate compounds, in particular, ditolyl diisocyanate, toluene diisocyanate or hexamethylene diisocyanate, or these isocyanate compounds and glycerol or trishydroxyl An adduct obtained by reacting a polyol such as a propane or the like, or an isocyanate system thereof The compound is formed into a dimer, a trimer or the like, and these isocyanate-based compounds are preferably mixed, and are preferably used. When the polar functional group-containing monomer (P2) has a polar functional group selected from the group consisting of a free carboxyl group, a hydroxyl group, an amine group and an epoxy ring, it is preferred to use at least one isocyanate compound as a crosslinking agent. Examples of suitable isocyanate-based compounds include an addition product of toluene diisocyanate, a reaction of ditolyl diisocyanate with a polyhydric alcohol, a dimer of toluene diisocyanate, and a trimer of ditolyl isocyanate, hexamethylene diisocyanate, an adduct obtained by reacting hexamethylene diisocyanate with a polyhydric alcohol, a dimer of hexamethylene diisocyanate, and A trimer of hexamethylene diisocyanate.

In the adhesive layer constituting the polarizing plate of the present invention, the crosslinking agent is preferably 0.01 to 5 parts by mass based on 100 parts by mass of the acrylic resin (P). The content of the crosslinking agent is preferably from 0.1 to 5 parts by mass, more preferably from 0.2 to 3 parts by mass, per 100 parts by mass of the acrylic resin (P). When the amount of the crosslinking agent is within the above range, the durability of the adhesive layer tends to be improved, and the white point of the liquid crystal display panel tends to be conspicuous, which is preferable.

In the adhesive for forming an adhesive layer in the present invention, a decane-based compound is preferred, and in particular, a decane-based compound is preferably contained in the acrylic resin before the crosslinking agent is blended. Since the decane-based compound enhances the adhesion to the glass, the adhesion of the liquid crystal cell and the adhesive layer which are caught by the glass substrate is improved by containing the decane-based compound, and a high adhesion to the display panel can be secured.

Examples of the decane-based compound include vinyl trimethoxy decane, vinyl triethoxy decane, and vinyl ginseng (2- Methoxyethoxy)decane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxydecane, N-(2-aminoethyl)-3-aminopropyl Trimethoxy decane, 3-aminopropyltriethoxy decane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 2 -(3,4-epoxycyclohexyl)ethyltrimethoxydecane, 3-chloropropylmethyldimethoxydecane, 3-chloropropyltrimethoxydecane, 3-methylpropenyloxy Propyltrimethoxydecane, 3-mercaptopropyltrimethoxydecane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltriethoxydecane, 3-epoxy Propyloxydimethoxymethylnonane, 3-glycidoxypropylethoxydimethyldimethyloxane, and the like. These decane-based compounds may be used singly or in combination of two or more.

The decane compound may be a polyoxyxene oligomer type. When the polyoxynene oligomer is represented by a (monomer)-(monomer) copolymer, for example, those shown below can be mentioned.

3-mercaptopropyltrimethoxynonane-tetramethoxydecane copolymer, 3-mercaptopropyltrimethoxydecane-tetraethoxydecane copolymer, 3-mercaptopropyltriethoxydecane-tetramethoxy a mercapto-containing copolymer, a copolymer containing a mercaptopropyl group such as a 3-mercaptopropyltriethoxydecane-tetraethoxydecane copolymer; a mercaptomethyltrimethoxydecane-tetramethoxydecane copolymer, Mercaptomethyltrimethoxydecane-tetraethoxydecane copolymer, mercaptomethyltriethoxydecane-tetramethoxydecane copolymer, and mercaptomethyltriethoxydecane-tetraethoxydecane copolymer a copolymer containing a mercaptomethyl group; 3-methacryloxypropyltrimethoxydecane-tetramethoxydecane copolymer, 3-methylpropenyloxypropyltrimethoxydecane-tetraethyl Oxyquinone Copolymer of alkane, 3-methacryloxypropyltriethoxydecane-tetramethoxydecane copolymer, 3-methylpropenyloxypropyltriethoxydecane-tetraethoxydecane copolymerization , 3-methacryloxypropylmethyldimethoxydecane-tetramethoxydecane copolymer, 3-methylpropenyloxypropylmethyldimethoxydecane-tetraethoxy a decane copolymer, a 3-methacryloxypropylmethyldiethoxydecane-tetramethoxydecane copolymer, and a 3-methylpropenyloxypropylmethyldiethoxydecane-four a copolymer containing a methacryloxypropyl group such as an ethoxylated decane copolymer; a 3-propenyloxypropyltrimethoxydecane-tetramethoxydecane copolymer, 3-propenyloxypropyl Trimethoxydecane-tetraethoxydecane copolymer, 3-propenyloxypropyltriethoxydecane-tetramethoxydecane polymer, 3-propenyloxypropyltriethoxydecane-four Ethoxy decane copolymer, 3-propenyl methoxy propyl methyl dimethoxy decane-tetramethoxy decane copolymer, 3-propenyl methoxy propyl methyl dimethoxy decane - tetraethoxy Lysane copolymerization , 3-propenylmethoxypropylmethyldiethoxydecane-tetramethoxydecane copolymer, and 3-propenyloxypropylmethyldiethoxydecane-tetraethoxydecane copolymer, etc. Copolymer containing propylene methoxypropyl; vinyl trimethoxy decane-tetramethoxy decane copolymer, vinyl trimethoxy decane-tetraethoxy decane copolymer, vinyl triethoxy decane - Tetramethoxydecane copolymer, vinyltriethoxydecane-tetraethoxydecane copolymer, vinylmethyldimethoxydecane-tetramethoxydecane copolymer, vinylmethyldimethoxy Ethylene-tetraethoxy decane copolymer, vinyl methyl diethoxy decane-tetramethoxy decane copolymer, and vinyl methyl diethoxy decane-tetraethoxy decane copolymer Copolymerization 3-aminopropyltrimethoxydecane-tetramethoxydecane copolymer, 3-aminopropyltrimethoxydecane-tetraethoxydecane copolymer, 3-aminopropyltriethoxy Co-ane-tetramethoxydecane copolymer, 3-aminopropyltriethoxydecane-tetraethoxydecane copolymer, 3-aminopropylmethyldimethoxydecane-tetramethoxydecane copolymerization , 3-aminopropylmethyldimethoxydecane-tetraethoxydecane copolymer, 3-aminopropylmethyldiethoxydecane-tetramethoxydecane copolymer, and 3-amine An amine group-containing copolymer or the like such as a propylmethyldiethoxydecane-tetraethoxydecane copolymer.

Most of these decane-based compounds are liquid. The amount of the decane-based compound in the adhesive is usually 0.01 to 10 parts by mass, preferably 0.03 to 1 part by weight based on 100 parts by mass of the nonvolatile content of the acrylic resin (P) (total amount when two or more types are used). The ratio of parts by mass. When the amount of the decane-based compound is within the above range with respect to 100 parts by mass of the non-volatile content of the acrylic resin (P), the adhesion between the adhesive layer and the liquid crystal cell is improved, so that it is preferable to suppress decane from the adhesive layer. It is preferred that the compound has a tendency to bleed out.

In the present invention, the adhesive layer may contain an ionic compound. Ionic compounds can function as antistatic agents. In particular, the acrylic resin (P) contains an aromatic ring-containing (meth)acrylic compound represented by the above formula (IV), and when n in the formula (IV) is 2 or more, white spots can be effectively suppressed. When an ionic compound is blended in an adhesive containing an acrylic resin in which a monomer is copolymerized, it is possible to impart good antistatic properties while imparting an effect of suppressing white spots. The so-called ionic compound refers to The compound, the cation and the anion which are present in a combination of a cation and an anion may be either inorganic or organic, but from the viewpoint of compatibility with the acrylic resin (P), at least one of a cation and an anion contains an organic group. The ionic compound is preferred.

Examples of the inorganic cation constituting the ionic compound include an alkali metal ion such as a lithium cation [Li ⁺ ], a sodium cation [Na ⁺ ], a potassium cation [K ⁺ ], a phosphonium cation [Cs ⁺ ], and a ruthenium cation [ Be ²⁺ ], magnesium cation [Mg ²⁺ ], alkaline earth metal ions such as calcium cation [Ca ²⁺ ], and the like. Among them, from the viewpoint of metal corrosion resistance, lithium cation [Li ⁺ ], potassium cation [K ⁺ ] or sodium cation [Na ⁺ ] is preferably used, and from the viewpoint of durability, potassium cation is used [ K ⁺ ] is better.

Examples of the organic cation constituting the ionic compound include a pyridinium cation represented by the following formula (V) and a fourth ammonium cation represented by the following formula (VI).

In the formula (V), R ₅ to R ₉ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₁₀ represents an alkyl group having 1 to 16 carbon atoms. In the formula (VI), R ₁₁ represents an alkyl group having 1 to 12 carbon atoms, and R ₁₂ , R ₁₃ and R ₁₄ each independently represent an alkyl group having 6 to 12 carbon atoms.

The pyridinium-based cation represented by the above formula (V) has a total carbon number of 6 or more, but the total carbon number thereof is 8 or more, particularly 10 or more, from the viewpoint of compatibility with the acrylic resin (P). It is better. Further, the total carbon number is 36 or less, and more preferably 30 or less. In the pyridinium cation represented by the formula (V), R ₇ bonded to the carbon atom at the 4th position of the pyridine ring is an alkyl group, and R ₅ , R ₆ , R ₈ of the other carbon atom of the pyridine ring. And R ₉ is preferably a hydrogen atom, preferably a cation.

Specific examples of the pyridinium-based cation represented by the formula (V) include the following.

N-methyl-4-hexylpyridinium cation, N-butyl-4-methylpyridinium cation, N-butyl-2,4-diethylpyridinium cation, N-butyl-2-hexylpyridine Ruthenium cation, N-hexyl-2-butylpyridinium cation, N-hexyl-4-methylpyridinium cation, N-hexyl-4-ethylpyridinium cation, N-hexyl-4-butylpyridinium cation And N-octyl-4-methylpyridinium cation, N-octyl-4-ethylpyridinium cation, N-octylpyridinium cation, and the like.

The ammonium cation represented by the above formula (VI) is a tetraalkylammonium cation having a total carbon number of 20 or more, and further 22 or more, from the viewpoint of compatibility with the acrylic resin (P). It is better. Further, the total carbon number is 36 or less, and preferably 30 or less.

Specific examples of the tetraalkylammonium cation represented by the formula (VI) include those shown below.

Tetrahexylammonium cation, tetraoctyl ammonium cation, tributylmethylammonium cation Ionic, trihexylmethylammonium cation, trioctylmethylammonium cation, trimethylmethylammonium cation, trihexylethylammonium cation, trioctylethylammonium cation, and the like.

On the other hand, examples of the anion constituting the ionic compound include the following.

Chloride anion [Cl ^- ], bromide anion [Br ^- ], iodide anion [I ^- ], tetrachloroaluminate anion [AlCl ^4- ], heptachlorodisuccinate anion [Al ₂ Cl ₇ ^- ] , tetrafluoroborate anion [BF ₄ ^- ], hexafluorophosphate anion [PF ₆ ^- ], perchlorate anion [ClO ₄ ^- ], nitrate anion [NO ₃ ^- ], acetate anion [CH ₃ COO ^- ], trifluoroacetate anion [CF ₃ COO ^- ], methane sulfate anion [CH ₃ SO ₃ ^- ], trifluoromethane sulfate anion [CF ₃ SO ₃ ^- ], bis(trifluoromethanesulfonyl)醯imino anion [(CF ₃ SO ₂ ) ₂ N ^- ], ginseng (trifluoromethanesulfonyl) carbon anion [(CF ₃ SO ₂ ) ₃ C ^- ], hexafluoroarsenate anion [AsF ₆ ^- ] , hexafluoroantimonate anion [SbF ₆ ^- ], hexafluoroantimonate anion [NbF ₆ ^- ], hexafluoroantimonate anion [TaF ₆ ^- ], (poly) hydrofluorofluoride anion [F(HF) _n ^- ] (n is about 1 to 3), thiocyanate anion [SCN ^- ], dicyanamide anion [(CN) ₂ N ^- ], perfluorobutane sulfate anion [C ₄ F ₉ SO ₃ ^- ], bis(pentafluoroethanesulfonyl) quinone imine [(C ₂ F ₅ SO ₂ ) ₂ N ^- ], perfluorobutyric acid An ester anion [C ₃ F ₇ COO ^- ], (trifluoromethanesulfonyl) (trifluoromethanecarbonyl) quinone imine [(CF ₃ SO ₂ )(CF ₃ CO)N ^- ], and the like.

Specific examples of the ionic compound can be appropriately selected from the above combinations of cations and anions. Examples of the ionic compound which is a combination of a specific cation and an anion include the following.

Lithium bis(trifluoromethanesulfonyl) quinone imine, lithium hexafluorophosphate, lithium iodide (lithium iodide), lithium bis(pentafluoroethanesulfonyl) quinone imine, lithium ruthenium (trifluoromethane Sulfosyl)carbonate (Methanide), sodium bis(trifluoromethanesulfonyl) quinone imine, sodium bis(pentafluoroethanesulfonyl) quinone imine, sodium ginseng (trifluoromethanesulfonyl) carbon Anion, potassium bis(trifluoromethanesulfonyl) quinone imine, potassium bis(pentafluoroethanesulfonyl) quinone imine, potassium ginseng (trifluoromethanesulfonyl) carbon anion, N-methyl-4 -hexylpyridinium bis(trifluoromethanesulfonyl) quinone imine, N-butyl-2-methylpyridinium bis(trifluoromethanesulfonyl) quinone imine, N-hexyl-4-methylpyridine Bis(trifluoromethanesulfonyl) quinone imine, N-octyl-4-methylpyridinium bis(trifluoromethanesulfonyl) quinone imine, N-methyl-4-hexylpyridinium hexafluoro Phosphate, N-butyl-2-methylpyridinium hexafluorophosphate, N-hexyl-4-methylpyridinium hexafluorophosphate, N-octyl-4-methylpyridinium hexafluorophosphate, N-methyl-4-hexylpyridinium perchlorate, N-butyl-2-methylpyridinium perchlorate, N-hexyl-4-methylpyridinium Chlorate, N-octyl-4-methylpyridinium perchlorate, tetrahexylammonium bis(trifluoromethanesulfonyl) quinone imine, tributylmethylammonium bis(trifluoromethanesulfonyl) hydrazine Imine, trihexylmethylammonium bis(trifluoromethanesulfonyl) quinone imine, trioctylmethylammonium bis(trifluoromethanesulfonyl) quinone imine, tetrahexylammonium hexafluorophosphate, tributyl Alkyl ammonium hexafluorophosphate, trihexylmethyl ammonium hexafluorophosphate, trioctylmethyl ammonium hexafluorophosphate, tetrahexylammonium perchlorate, tributylmethylammonium perchlorate, trihexylmethylammonium Perchlorate, trioctylmethylammonium perchlorate, and the like.

These ionic compounds can be used individually or in combination of 2 or more types, respectively. When containing an ionic compound, its amount is relative to C. The ethylenic acid resin (P) is usually from 0.5 to 8 parts by mass, preferably from 0.8 to 4 parts by mass, per 100 parts by mass.

In the present invention, the adhesive layer may further contain a crosslinking catalyst, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, a resin other than an acrylic resin, or the like.

An ultraviolet curable compound such as a polyfunctional acrylate or a photoinitiator is blended in the adhesive, and after the adhesive layer is formed, it is cured by irradiation with ultraviolet rays, and a harder adhesive layer can also be used. In this way, the second crosslinked structure is specifically realized in the adhesive, and the function of improving durability such as heat resistance is exhibited. Further, when a crosslinking agent and a crosslinking catalyst are used together in the adhesive, the adhesive layer can be prepared by aging for a short period of time, and in the polarizing plate containing the obtained adhesive, generation between the polarizing plate and the adhesive layer can be suppressed. Float or peel off, or cause foaming in the adhesive layer, and the workability is also good.

As the crosslinking catalyst, for example, hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine may be mentioned. An amine compound such as trimethylenediamine, a polyamine resin, or a melamine resin. When an amine compound is formulated as a crosslinking catalyst in the adhesive, the crosslinking agent is preferably an isocyanate compound.

Further, it may contain fine particles and be an adhesive layer which exhibits light scattering. In the adhesive layer, an antioxidant or an ultraviolet absorber can also be added. Examples of the ultraviolet absorber include a salicylate-based compound, a benzophenone-based compound, a benzotriazole-based compound, a cyanoacrylate-based compound, and a nickel-salted salt-based compound.

The adhesive layer can be applied, for example, to the above-mentioned adhesive as an organic solvent solution, and applied to a film or layer (for example, a polarizing film or the like) to be laminated by a die coater or a gravure coater. It is set by its drying method. Further, a film-like adhesive formed on a plastic film (referred to as a separator) subjected to release treatment may be transferred to a film or layer to be laminated. The thickness of the adhesive layer is not particularly limited, but is preferably in the range of 2 to 40 μm, more preferably in the range of 5 to 35 μm, and even more preferably in the range of 10 to 30 μm.

The adhesive layer has a storage modulus of from 0.10 to 5.0 MPa in the range of from 23 to 80 ° C, more preferably from 0.15 to 1.0 MPa. When the storage elastic modulus at 23 to 80 ° C is 0.10 MPa or more, it is possible to suppress the white point caused by the shrinkage of the polarizing plate when the liquid crystal display panel in a state in which the liquid crystal cell is bonded to the polarizing plate is exposed to a high temperature or the like. It is better.

Moreover, when it is 5 MPa or less, it is difficult to cause a decrease in durability due to a decrease in adhesive strength, which is preferable. Here, "the storage elastic modulus of 0.10 to 5.0 MPa is shown in 23 to 80 ° C" means that the storage elastic modulus can obtain the above range even at any temperature within this range. The storage modulus is generally decreased as the temperature rises, so that when the storage elastic modulus at 23 ° C and 80 ° C falls within the above range, in the temperature of this range, storage in which the adhesive layer can exhibit the above range can be observed. Elasticity rate. Further, the storage modulus of the adhesive layer can be measured by a commercially available viscoelasticity measuring device such as a viscoelasticity measuring device "DYNAMIC ANALYZER RDA II" manufactured by REOMETRIC.

In a suitable aspect, the polarizing plate of the present invention The adhesive layer is an acrylic resin, a decane compound, and an isocyanate compound as a crosslinking agent, which are a copolymer of butyl acrylate, methyl acrylate, 2-hydroxyethyl acrylate, 2-phenoxyethyl acrylate, and acrylic acid. And antistatic components.

[Polarizing film]

The polarizing film constituting the polarizing plate of the present invention has a function of extracting linearly polarized light from incident natural light. In the present invention, the polyvinyl alcohol-based resin film contains iodine and is adsorbed and oriented. As the polyvinyl alcohol-based resin constituting the polyvinyl alcohol-based resin film, a polyvinyl acetate-based resin can be used. As the polyvinyl acetate-based resin, in addition to the polyvinyl acetate of the homopolymer of vinyl acetate, a copolymer of vinyl acetate and other monomers copolymerizable therewith (for example, ethylene-vinyl acetate copolymerization) may be mentioned. Things, etc.). Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and decyl acrylates having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin is usually from 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may also be modified. For example, polyvinyl formal, acetal, and polyvinyl butyral modified with an aldehyde may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually from 1,000 to 10,000, preferably from 1,500 to 5,000.

A film made of such a polyvinyl alcohol-based resin can be used as a film of a polarizing film. The method of forming a film of a polyvinyl alcohol-based resin is not particularly limited, and a film can be formed by a conventionally known method. The film thickness of the germ film composed of the polyvinyl alcohol-based resin is not particularly limited, but it is easy to consider The extensibility is, for example, 10 to 150 μm, preferably 15 to 100 μm, more preferably 20 to 80 μm.

The polarizing film is usually subjected to a step of uniaxially stretching such a polyvinyl alcohol-based resin film; the polyvinyl alcohol-based resin film is dyed with iodine to thereby adsorb iodine; and the iodine-adsorbing polyvinyl alcohol-based resin is used. The film is treated with an aqueous solution of boric acid; and the step of washing with an aqueous solution of boric acid followed by washing with water.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be carried out before the dyeing of iodine, or simultaneously with the dyeing, or after the dyeing. When the uniaxial stretching is carried out after dyeing, the uniaxial stretching can also be carried out before the boric acid treatment or in the boric acid treatment. Uniaxial stretching can also be performed at these multiple stages. When uniaxially extending, it is also possible to extend a single shaft between rolls having different peripheral speeds, or to use a hot roll to extend toward a single shaft. Further, the uniaxial stretching system may be a dry stretching extending in the air, or a solvent may be used to extend the wet state of the polyvinyl alcohol resin film in a state of being swollen. The stretching ratio is preferably 8 times or less, more preferably 7.5 times or less, still more preferably 7 times or less from the viewpoint of suppressing deformation of the polarizing film. Further, the stretching ratio is preferably 4.5 times or more from the viewpoint of exhibiting the function as a polarizing film.

In the present invention, a method in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing iodine and potassium iodide and dyed is usually used. The content of iodine in the aqueous solution is usually 0.01 to 1 part by mass per 100 parts by mass of water, and the content of potassium iodide is usually 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing, usually 20 to 40 ° C, Further, the immersion time (dyeing time) of the aqueous solution is usually 20 to 1800 seconds.

The boric acid treatment after dyeing with iodine can be carried out by immersing the dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid. The amount of boric acid in the aqueous solution containing boric acid is usually 2 to 15 parts by mass, preferably 5 to 12 parts by mass per 100 parts by mass of water. In the present invention, the aqueous solution containing boric acid preferably contains potassium iodide. The amount of potassium iodide in the aqueous solution containing boric acid 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 for the aqueous solution containing boric acid is usually from 60 to 1200 seconds, preferably from 150 to 600 seconds, more preferably from 200 to 400 seconds. The temperature of the aqueous solution containing boric acid is usually 50 ° C or higher, preferably 50 to 85 ° C, more preferably 60 to 80 ° C.

The polyvinyl alcohol-based resin film after boric acid treatment is usually washed with water. The water washing treatment can be carried out, for example, by immersing a boric acid-treated polyvinyl alcohol-based resin film in water. The temperature of the water in the water washing treatment is usually 5 to 40 ° C, and the immersion time is usually 1 to 120 seconds. After washing, the drying treatment is carried out to obtain a polarizing film. The drying treatment can be carried out using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually from 30 to 100 ° C, preferably from 40 to 95 ° C, more preferably from 50 to 90 ° C. The drying treatment time is usually from 60 to 600 seconds, preferably from 120 to 600 seconds.

In the polyvinyl alcohol-based resin film, uniaxial stretching, dyeing with iodine, and boric acid treatment are carried out to obtain a polarizing film. The thickness of the polarizing film may be, for example, 5 to 40 μm.

[2nd hardened layer]

The polarizing plate of the present invention may have a second cured layer composed of a cured product of a curable composition on a surface of the polarizing film opposite to the first cured layer. The curable composition constituting the second cured layer may be the same as or different from the curable composition constituting the first cured layer. The second cured layer may be appropriately selected in accordance with the adhesion to the polarizing film or the second transparent protective film.

In one embodiment of the present invention, the second cured layer also exhibits a transparent protective film (5 in Figs. 1 and 2) for the polarizing film and the layer on the opposite side of the liquid crystal cell. When the curable composition constituting the second cured layer is different from the curable composition constituting the first cured layer, the curable composition constituting the second cured layer can be used, for example. Photohardenability followers known in the art. For example, a mixture of a photocurable epoxy resin and a photocationic polymerization initiator or a mixture of a photocurable acrylic resin and a photoradical polymerization initiator may be mentioned. The curable composition that forms the cured product constituting the second cured material layer is appropriately selected depending on the adhesion of the polarizing film or the second transparent protective film, and is described in, for example, International Publication No. 2014/129368. A photocurable adhesive containing a photocurable component and a photocationic polymerization initiator can be used.

In the present invention, the second cured layer can be made of a curable composition (photocurable adhesive) on the surface opposite to the surface on which the first cured layer of the polarizing plate is laminated. The method is formed by coating. For example, a casting method, a Meyer bar coating method, a gravure coating method, a corner wheel coating method, a doctor blade method, a die coating method, a dip coating method, and a spray method can be used. Wait. The casting method is a method in which the film of the object to be coated is moved in the approximate vertical direction, the approximate horizontal direction, or the oblique direction therebetween, and the adhesive is allowed to flow down on the surface thereof to expand. After the application of the curable composition, the polarizing film and the transparent protective film bonded thereto are superposed, and the film is adhered by being kneaded by a kneading roller or the like. The adhesion of the film using the kneading roll can be, for example, a method of uniformly pressing and expanding by pressing with a roll or the like after applying the curable composition, and after applying the curable composition, passing through the roll and the roll. A method of pressurizing and expanding, and the like. At this time, the material of the roller used may be metal or rubber. Moreover, when a film is passed between a plurality of rolls, when the extrusion is expanded, the plurality of rolls may be of the same material or different materials.

When a photocurable adhesive is used, the photocurable adhesive is cured by irradiation of an active energy ray. Although the light source of the active energy ray is not particularly limited, it is preferably an active energy ray having a light-emitting distribution at a wavelength of 400 nm or less, specifically, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, and a black light. Lights, microwave excitation mercury lamps, metal halide lamps, etc. are preferred.

The light irradiation intensity of the photocurable adhesive is appropriately determined depending on the composition of the photocurable adhesive, and is not particularly limited, but the irradiation intensity in the wavelength range in which the activation of the polymerization initiator is effective is preferably 0.1 to 6000mW / cm ^2, more preferably 10 to line 1000mW / cm ^2, and still more preferably 20 to line 500mW / cm ^2. When the irradiation intensity is within the above range, the reaction time can be ensured, and yellowing of the epoxy resin or deterioration of the polarizing film due to heat radiated from the light source and heat generated during curing of the photocurable adhesive can be suppressed. . The light irradiation time of the photocurable adhesive may be appropriately selected by a photocurable adhesive which is cured, and is not particularly limited, but is expressed as a product of the irradiation intensity and the irradiation time. The cumulative amount of light is preferably set to 10 to 10000 mJ/m ² , preferably 50 to 1000 mJ/m ² , more preferably 80 to 500 mJ/m ² . When the amount of accumulated light of the photocurable adhesive is within the above range, the active species derived from the polymerization initiator is generated in a sufficient amount, and the curing reaction can be performed more surely, and the irradiation time is not too long, and can be maintained. Good productivity.

Further, when the photocurable adhesive is cured by irradiation with an active energy ray, for example, the polarizing film of the polarizing film, the transmittance and the hue, and the transparency of the transparent protective film and the various films constituting the optical layer are polarized. It is preferable that each function is hardened without lowering the condition. The thickness of the second cured layer is not particularly limited, but is usually 0.1 to 10 μm.

[Transparent protective film]

In one embodiment, the polarizing plate of the present invention has a first transparent protective film (6 in FIG. 2) in which one layer is interposed between the first cured layer on one surface of the polarizing film. Further, in one embodiment, the polarizing plate of the present invention has a second transparent protective film (fifth in Figs. 1 and 2) on which the second cured layer is laminated on the other surface of the polarizing film. In one embodiment, the polarizing plate of the present invention has the first transparent protective film from the viewpoint of contributing to prevention of prevention of shrinkage and expansion of the polarizing film, temperature, humidity, ultraviolet rays, and the like. . On the other hand, from the viewpoint of the reduction in thickness of the polarizing plate, in one embodiment, the polarizing plate of the present invention does not contain the first transparent protective film. The first hardened layer of the present invention replaces the transparent The protective film also contributes to prevention of the prevention of the polarizing film, and it is preferable that the polarizing plate of the present invention does not contain the first transparent protective film from the viewpoint of achieving good balance of prevention of deterioration of the polarizing film and reduction in thickness of the polarizing plate. .

As a material for forming a transparent protective film, it is preferable to be excellent in transparency, mechanical strength, thermal stability, moisture shielding property, and the like. For example, a polyester-based polymer such as polyethylene terephthalate or polyethylene naphthalate, a cellulose-based polymer such as diethyl hydrazine cellulose or triethylene fluorenyl cellulose, or the like may be mentioned. An acrylic polymer such as polymethyl methacrylate, a styrene polymer such as polystyrene or an acrylonitrile/styrene copolymer (AS resin), or a polycarbonate polymer. Further, examples thereof include polyolefins having a polyethylene, polypropylene, ring or norbornene structure; polyolefin polymers such as ethylene/propylene copolymers, vinyl chloride polymers, nylon or aromatic polyamides, and the like. Amidoxime polymer, quinone-based polymer, fluorene-based polymer, polyether fluorene-based polymer, polyetheretherketone-based polymer, polyphenylene sulfide-based polymer, vinyl alcohol-based polymer, partial A vinyl chloride polymer, a vinyl butyral polymer, an aromatic acid ester polymer, a polyoxymethylene polymer, an epoxy polymer, or a mixture of the above polymers, etc., also form a polymer of a transparent protective film. example. The transparent protective film is a thermosetting type such as an acrylic type, a polyurethane type, an acrylamide type, an epoxy type, or a polyoxymethylene type, and the ultraviolet curable type resin can also form a cured layer. Among them, those having a hydroxyl group having reactivity with an isocyanate crosslinking agent are preferred, and a cellulose-based polymer is particularly preferred.

In the polarizing plate of the present invention, the first transparent protective film and the second transparent protective film may be composed of the same material or may be composed of different materials.

The thickness of the transparent protective film is not particularly limited, but the first transparent protective film and the second transparent protective film are generally 500 μm or less, preferably 1 to 300 μm, preferably 5 to 200 μm, and 10 to 100 μm is more preferred. Further, the transparent protective film may be formed of a transparent protective film or the like which has been subjected to an optical compensation function.

In the polarizing plate of the present invention, the first cured layer can effectively suppress the movement of iodine from the polarizing film to the adhesive layer and the movement of the ionic compound from the adhesive layer to the polarizing film, so that the first constituent of the polarizing plate 1 The choice of transparent protective film material is wide. In other words, it is not necessary to use a transparent protective film that does not easily transmit an ionic compound, and a polarizing plate can be formed by using a transparent protective film which is generally inexpensive and permeable to an ionic compound. Thereby, the production cost can be made cheap, and the polarizing plate of the present invention is also advantageous from the industrial viewpoint.

Specifically, for example, the absorbance of light of 360 nm can be used as an initial absorbance, and immersed in an atmosphere of 23° C. and 60% RH in an atmosphere of 50% by mass of potassium iodide for 4.5 hours, and taken out at 23° C. in the atmosphere. After 15 seconds of water washing and drying in the dark at 23 ° C for 15 hours in the air, the absorbance of the measured light of 360 nm was transparent as a transparent protective film having a large value of 5% or more for the initial absorbance. Protective film.

The polarizing plate of the present invention may further laminate an optical layer such as a retardation film, a viewing angle compensation film, and a brightness enhancement film, if necessary. In the polarizing plate of the present invention, the optical layer can be formed using materials known in the art.

The polarizing plate of the present invention can be produced by a known method. For example, a curable composition is applied to a transparent protective film to form a second hardened composition layer, and a polarizing film is bonded to the second hardened composition layer to form a laminated body. When the polarizing plate of the first protective film is not contained, the curable composition is applied onto the releasable film to form a first hardened composition layer, and the polarizing film side of the laminated body is bonded to the coated surface. Then, the second hardened composition layer and the first hardened composition layer are cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam to form a second hardened composition layer and a first cured layer. Thereafter, the release film is peeled off, and it is only necessary to form an adhesive layer on the first cured layer.

On the other hand, when the polarizing plate of the first transparent protective film is applied, the curable composition is applied onto the transparent protective film to form the first hardened composition layer, and after the coated surface is bonded to the polarizing film side of the laminated body The first energy-sensitive layer is cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam to form a first cured layer, and secondly, an adhesive layer is formed on the first transparent protective film. Further, the polarizing plate not including the first transparent protective film is preferable from the viewpoint of being able to be a thinner polarizing plate.

[Sclerosing composition and cured product thereof]

The invention also relates to a sclerosing composition. The curable composition of the present invention contains, as a polymerizable compound, (A1) an oxetane compound 35 having two or more oxetanyl groups, to 100% by mass based on the total amount of the polymerizable compound. 70% by mass, (A2) an aliphatic epoxy compound having 2 or more epoxy groups, 0 to 40% by mass, (A3) an alicyclic epoxy compound having 2 or more epoxy groups, 15 to 50% by mass % and (A4) 0 to 20% by mass of the aromatic epoxy compound having one or more aromatic rings, and Containing (B) a photocationic polymerization initiator. The suitable content of the polymerizable compounds (A1) to (A4) in the curable composition of the present invention, and the polymerizable compound in the curable composition of the first cured layer constituting the above-described polarizing plate of the present invention ( The contents of A1) to (A4) are the same. Further, the polymerizable compounds (A1) to (A4) and the photocationic polymerization initiator (B) and the polymerizable compound in the curable composition of the first cured layer constituting the above-described polarizing plate of the present invention ( A1) to (A4) and the photocationic polymerization initiator (B) are the same.

In the cured product produced by curing the curable composition of the present invention, it is difficult to permeate iodine under high temperature and high humidity, and for example, a cured layer which is a constituent of a polarizing plate used in an image display processing device or the like can be suitably used. Or the material of the adhesive layer. In particular, since the cured product of the curable composition of the present invention is excellent in compactness, it is possible to effectively suppress iodine contained in the polarizing film or an antistatic component (ionic compound) contained in the adhesive layer to constitute polarized light. The other layers of the board move. Therefore, for example, the cured layer formed of the cured product of the curable composition of the present invention can suppress the movement of various components as a layer constituting the polarizing plate, and a polarizing plate excellent in optical performance can be obtained. In addition, by using the cured product of the curable composition of the present invention instead of the transparent protective film provided in the conventional polarizing plate, a thinner polarizing plate can be produced.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited to the examples. In addition, "%" and "parts" in the examples and comparative examples indicate "% by mass" and "parts by mass" unless otherwise stated.

Example 1

1. Modulation of the curable composition (A) constituting the first cured layer

The curable composition (A) of Example 1 was prepared by mixing the polymerizable compounds (A1), (A2), (A3) and (A4) and the photocationic polymerization initiator (B) according to the composition of the following Table 1. .

2. Modulation of the curable composition (a) constituting the second cured layer

The following polymerizable compounds (a1), (a2), (a3), and (a4) and a photocationic polymerization initiator (b1) are mixed to prepare a curable composition (a).

(a1) 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate: 25 parts by mass

(a2) neopentyl diglycidyl ether: 55 parts by mass

(a3) A polymer having a weight average molecular weight of 15,000 (GMA-PMMA (polymethyl methacrylate)) which is a radical polymerization of a monomer composed of 25 parts of glycidyl methacrylate and 75 parts of methyl methacrylate. Copolymer): 15 parts by mass

(a4) hydroxybutyl vinyl ether: 5 parts by mass

(b1) triarylsulfonium hexafluorophosphate: 2.25 parts by mass

3. Modulation of the adhesive composition constituting the adhesive layer

The acrylic adhesive was prepared in the following manner.

70.4 parts by mass of butyl acrylate, 20.0 parts by mass of methyl acrylate, 0.6 parts by mass of acrylic acid, 8.0 parts by mass of 2-phenoxyethyl acrylate and 1.0 part by mass of 2-hydroxyethyl acrylate were added as a polymerization initiator. 0.14 parts by mass of azobisisobutyronitrile, polymerization reaction, modulation of acrylic tree fat. An isocyanate-based crosslinking agent (Coronate L; an ethyl acetate solution of a trimethylolpropane adduct of toluene diisocyanate (solid content concentration: 75%), Japan was added to 20.0 parts by mass of the solid content of the acrylic resin. 0.45 parts by mass of a decane coupling agent (KBM-403: 3-glycidoxypropyltrimethoxydecane (liquid), manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.45 parts by mass An electrostatic solvent (1-hexylpyridinium hexafluorophosphate (compound represented by the following formula (VII))) was added in an amount of 3.0 parts by mass to prepare an organic solvent solution of an acrylic resin adhesive.

4. Production of polarizing plate

(1) The polarizing plate of Example 1

(i) Production of laminated body (1)

Corona discharge treatment was carried out on the surface of an acrylic resin (PMMA) film (product name "Technolloy S001", manufactured by Sumitomo Chemical Co., Ltd.) (corresponding to the second transparent protective film) having a thickness of 60 μm containing an ultraviolet absorber. On the corona discharge treatment surface, the curable composition (a) prepared as described above was applied by a bar coater so as to have a film thickness after hardening of about 3 μm to form a layer of a curable composition (a) (corresponding to In the second hardened layer). Next, a polyvinyl alcohol (PVA)-iodine-based polarizing film having a thickness of 25 μm was bonded to the curable composition (a) layer to prepare a laminate. The ultraviolet light irradiation device (the lamp is a "D bulb" manufactured by Fusion UV Systems Co., Ltd.) equipped with a belt conveyor is used to irradiate the polarizing film side of the laminate with a cumulative light amount of 280 nm to 320 nm of 200 mJ/cm ² . Ultraviolet light is used to cure the curable composition, and a laminate (1) composed of an acrylic resin film (second transparent protective film) / a second cured layer / a polarizing film is produced.

(ii) Production of laminated body (2)

In a single surface of a cycloolefin film (product name "ZEONOR", manufactured by Zeon Co., Ltd.) having a thickness of 50 μm, the bar coater of the curable composition (A) of Example 1 prepared as described above was used. The film thickness after hardening was about 3 micrometers. The side of the polarizing film of the laminated body (1) was bonded to the coated surface to prepare a laminate. From the side of the cycloolefin film of the laminate, an ultraviolet irradiation device equipped with a belt conveyor (the lamp is a "D bulb" manufactured by Fusion UV Systems Co., Ltd.) was used, and the cumulative light amount at 280 nm to 320 nm was 200 mJ/cm ² . The ultraviolet ray is irradiated to cure the curable composition (A), and then the cycloolefin film is peeled off. In this manner, a laminate (2) composed of an acrylic resin film (second transparent protective film) / a second cured layer / a polarizing film / a first cured layer was produced.

(iii) Production of a polarizing plate (without the first transparent protective film)

The organic solvent solution of the acrylic resin adhesive prepared in the above 3. was subjected to a release treatment of a polyethylene terephthalate film having a thickness of 38 μm [trade name "SP-PLR382050", manufactured by Lintec Co., Ltd. ( In the release treatment surface, which is referred to as "release film"), it is applied by a die coater so as to have a thickness of 20 μm after drying, and dried to prepare a release film-like adhesive. Then, on the side of the first cured product layer of the layered product (2) produced in the above (ii), the surface (adhesive surface) opposite to the release film of the sheet-like adhesive is bonded by a laminator. After that, at a temperature of 23 ° C, phase The mixture was aged for 7 days under the conditions of a humidity of 65% to obtain a polarizing plate (without a first transparent protective film) provided with an adhesive layer. The polarizing plate is attached to the adhesive layer to form a structure in which the release film is attached.

(iv) Production of a polarizing plate (with a first transparent protective film)

Corona discharge treatment was carried out on the surface of a cellulose-based transparent protective film having a thickness of 40 μm (trade name "ZRE 34", manufactured by Fujifilm Co., Ltd.) (corresponding to the first transparent protective film). The treatment surface was coated with the curable composition (A) of Example 1 having the composition of Table 1 so that the film thickness after curing was about 3 μm using a bar coater. On the coated surface, the polarizing film side of the layered product (1) produced in the same manner as in the above (i) was bonded to each other to form a laminate. From the side of the cellulose-based transparent protective film of the laminate, an ultraviolet irradiation device equipped with a belt conveyor [the lamp is a "D bulb" manufactured by Fusion UV Systems Co., Ltd.] is used, and the cumulative amount of light from 280 nm to 320 nm becomes 200 mJ/cm. ^In the method of ² , ultraviolet rays are irradiated to cure the curable composition (A), thereby producing an acrylic resin film (second transparent protective film) / second cured material layer / polarizing film / first cured layer / cellulose A layered body (2') composed of a transparent protective film (first transparent protective film). Then, a sheet-like adhesive is bonded to the side of the cellulose-based transparent protective film of the layered product (2') in the same manner as in the above (iii), and a polarizing plate provided with an adhesive layer (the first transparent protective film) is obtained. ).

(2) Polarizing plates of Examples 2 to 12

A curable composition having a composition according to Table 1 was used as a curable composition constituting the first cured layer, and a polarizing plate (without the first transparent protective film) and a polarizing plate were obtained in the same manner as in the polarizing plate of Example 1. (there are 1 transparent protective film).

(3) Polarizing plates of Comparative Examples 1 to 7

Using a curable composition having a composition according to Table 2 as a curable composition constituting the first cured layer, a polarizing plate (without the first transparent protective film) and a polarizing plate were obtained in the same manner as in the polarizing plate of Example 1. There is a first transparent protective film).

In addition, the cellulose-based transparent protective film [trade name "ZRE 34", manufactured by Fujifilm Co., Ltd.) was measured for the absorbance at 360 nm as the initial absorbance. The film was immersed in a 50% by mass potassium iodide aqueous solution at the same temperature for 23 hours in an atmosphere of 23 ° C 60% RH, taken out, washed with water at 23 ° C for 15 seconds, and dried in the atmosphere at 23 ° C in the dark. After the hour, the absorbance of light for 360 nm was measured for this film, and the absorbance was increased by 22% with respect to the initial absorbance.

5. Durability evaluation of polarizing plates

Each of the obtained polarizing plates of Examples 1 to 12 and Comparative Examples 1 to 7 was cut into a size of 30 mm × 30 mm, and the release film was peeled off, and the alkali-free glass was attached to the adhesive layer side [trade name "EAGLE" XG", seeking the company system]. Regarding this sample, durability evaluation based on optical properties was performed as follows.

Each sample was subjected to autoclave treatment at a temperature of 50 ° C and a pressure of 5 kg/cm ² (490.3 kPa) for 1 hour, and then left to stand in an environment of a temperature of 23 ° C and a relative humidity of 55% for 24 hours. For this sample, the "Film holder with polarizing film" of the option accessory was placed in an ultraviolet-visible spectrophotometer (U V2450, manufactured by Shimadzu Corporation) to measure the transmission of the polarizing plate in the wavelength range of 380 to 700 nm. The transmission spectrum of the axial direction and the absorption axis direction is used to determine the degree of polarization Py (unit: %). Thereafter, the mixture was allowed to stand in an environment of 85 ° C and a relative humidity of 85% for 12 hours, and then the transmission spectrum was measured in the same manner. The degree of polarization Py in a state before standing for 12 hours in an environment of 85 ° C and a relative humidity of 85% was used as an initial value, and the change in polarization degree ΔPy was calculated from the following formula. This result is shown in Table 1.

△Py=Py-initial Py after test

The compounds in Table 1 are as follows.

Oxetane compound (bifunctional): bis(3-ethyl-3-oxetanylmethyl)ether (OXT221, manufactured by Toagosei Co., Ltd.)

Aliphatic epoxy compound (1) (bifunctional): 1,4-butanediol diglycidyl ether (EX-214, manufactured by Nagase Chemical Technology Co., Ltd.)

Aliphatic epoxy compound (2) (bifunctional): 1.6-hexanediol diglycidyl ether (EX-212, manufactured by Nagase Chemical Technology Co., Ltd.)

Aliphatic epoxy compound (3) (bifunctional): neopentyl glycol diglycidyl ether (EX-211, manufactured by Nagase Chemical Technology Co., Ltd.)

Aliphatic epoxy compound (4) (2-functional): cyclohexane dimethanol diglycidyl ether (EX-216, manufactured by Nagase Chemical Technology Co., Ltd.)

Aliphatic epoxy compound (5) (4-functional): pentaerythritol polyglycidyl ether (EX-411, manufactured by Nagase Chemical Technology Co., Ltd.)

Alicyclic epoxy compound (bifunctional): 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (CEL2021P, manufactured by Daicel Chemical Co., Ltd.)

Aromatic epoxy compound (1) (trifunctional): 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-([ 2,3-epoxypropoxy]phenyl]ethyl]phenyl]propane (TECHMORE VG 3101L, manufactured by Printec Co., Ltd.)

Aromatic epoxy compound (2) (bifunctional): resorcinol diglycidyl ether (EX-201, manufactured by Nagase Chemical Technology Co., Ltd.)

Aromatic epoxy compound (3) (bifunctional): bisphenol F type epoxy (jER806, manufactured by Mitsubishi Chemical Corporation)

Aromatic epoxy compound (4) (1 functional): p-tertiary butyl phenyl glycidol Ether (EX-146, Changchun Chemical Technology Co., Ltd.)

Aliphatic epoxy compound (1-functional): 2-ethylhexyl glycidyl ether (EX121, manufactured by Nagase Chemical Technology Co., Ltd.)

Oxetane compound (1-functional): 3-ethyl-3-hydroxymethyl oxetane (OXT101, manufactured by Toagos Corporation)

Photocationic polymerization initiator: triarylsulfonium hexafluorophosphate

Example 13

(A1) The amount of the oxetane compound (bifunctional) (OXT221) is 60 parts by mass, and (A2) does not use the aliphatic epoxy compound (1) (bifunctional) (EX-214) (usage amount) 0 parts by mass), (A2) does not use an aliphatic epoxy compound (2) (bifunctional) (EX-212) (amount used is 0 parts by mass), (A3) an alicyclic epoxy compound (2-functional) (CEL2021P The amount of use is 40 parts by mass, and the amount of the (A4) aromatic epoxy compound (1) (trifunctional) (TECHMORE VG 3101L) is 0 parts by mass, and the rest is the same as in the first embodiment. The curable composition (A) is prepared. The curable composition constituting the first cured layer was treated in the same manner as in Example 1 except that the curable composition (A) obtained above was used instead of the curable composition (A) obtained in Example 1. A polarizing plate (without the first transparent protective film) provided with an adhesive layer was obtained, and durability evaluation was performed in the same manner as in Example 1, and ΔPy was -0.04.

Example 14

In addition to making (A1) oxetane compound (2-functional) (OXT 221) The curable composition was prepared in the same manner as in Example 13 except that the amount of the (A3) alicyclic epoxy compound (bifunctional) (CEL 2021P) was 50 parts by mass. (A), a polarizing plate (without a first transparent protective film) provided with an adhesive layer was obtained, and durability evaluation was performed, and ΔPy was -0.04.

The (A1) oxetane compound (2) (bifunctional) used in the following Examples 15 to 18 is as follows.

(A1) oxetane compound (2) (bifunctional): xylylene dioxetane (OXT121, manufactured by Toagosei Co., Ltd.)

Example 15

(A1) The amount of use of the oxetane compound (2) (bifunctional) (OXT121), except that the amount of the (A1) oxetane compound (bifunctional) (OXT221) is 45 parts by mass. 5 parts by mass, the amount of the (A3) alicyclic epoxy compound (bifunctional) (CEL 2021 P) is 40 parts by mass, and (A4) an aromatic epoxy compound (3 functional) (TECHMORE VG) The amount of use of 3101L) was changed to 10 parts by mass, and the curable composition (A) was prepared in the same manner as in Example 13 to obtain a polarizing plate (without a first transparent protective film) provided with an adhesive layer. Durability evaluation was performed, and ΔPy was -0.07.

Example 16

In addition to the amount of (A1) oxetane compound (bifunctional) (OXT 221) used as 40 parts by mass, (A1) the oxetane compound (2) (bifunctional) (OXT 121) The amount used is set to 10 parts by mass, (A3) The amount of use of the alicyclic epoxy compound (bifunctional) (CEL 2021P) is 40 parts by mass, and (A4) the amount of the aromatic epoxy compound (3-functional) (TECHMORE VG 3101L) is used. The hardening composition (A) was prepared in the same manner as in Example 13 except that 10 parts by mass, and a polarizing plate (without the first transparent protective film) provided with the pressure-sensitive adhesive layer was obtained, and durability evaluation was performed, ΔPy. Is -0.08.

Example 17

(A1) The oxetane compound (2) (bifunctional) (OXT 121) is not used except that the amount of the (A1) oxetane compound (2-functional) (OXT 221) is 50 parts by mass. (0 parts by mass), (A3) The amount of the alicyclic epoxy compound (bifunctional) (CEL 2021P) is 45 parts by mass, and (A4) an aromatic epoxy compound (3 functional) (TECHMORE VG) The amount of use of 3101L) was changed to 5 parts by mass, and the curable composition (A) was prepared in the same manner as in Example 16 to obtain a polarizing plate (without a first transparent protective film) provided with an adhesive layer. Durability evaluation was performed, and ΔPy was -0.06.

Example 18

The amount of (A3) alicyclic epoxy compound (bifunctional) (CEL 2021P) used is set to 50 parts by mass, and the amount of the (A1) oxetane compound (2-functional) (OXT 221) is 50 parts by mass. 35 parts by mass, (A4) The same applies to Example 17 except that the amount of the aromatic epoxy compound (trifunctional) (TECHMORE VG 3101L) is 15 parts by mass. When the curable composition (A) was prepared, a polarizing plate (without a first transparent protective film) provided with an adhesive layer was obtained, and durability evaluation was performed, and ΔPy was -0.05.

In the polarizing plates of Examples 1 to 18 having a first cured layer composed of a cured product containing a curable composition of the polymerizable compounds (A1) to (A4) in the range of the present invention, the degree of polarization changes ΔPy was small, and the optical performance did not change much even in a severe environment of high temperature and high humidity, and it was confirmed that high durability was exhibited. On the other hand, in Comparative Examples 1 to 7 having a first cured layer composed of a cured product containing a curable composition of the polymerizable compounds (A1) to (A4) in a range not in the range of the present invention, Any of the obtained polarizing plates had a large change in polarization degree ΔPy, and a decrease in optical performance was observed. In addition, when the curable composition constituting the first cured layer contains the polymerizable compounds (A1) to (A4) in the range of the present invention, optical properties are not present even if a transparent protective film is not present between the polarizing film and the adhesive layer. Without deterioration, it was found that high durability was exhibited (Examples 1 to 18). On the other hand, when the curable composition constituting the first cured layer contains the polymerizable compounds (A1) to (A4) in the range of the present invention, even if a transparent protective film is present between the polarizing film and the adhesive layer, It was also found that the optical performance was drastically lowered (Comparative Examples 1 to 7).

1‧‧‧ polarizing film

2‧‧‧1st hardened layer

3‧‧‧Adhesive layer

4‧‧‧2nd hardened layer

5‧‧‧2nd transparent protective film

10‧‧‧Polar plate

X‧‧‧ liquid crystal unit

Claims (17)

a polarizing plate which is provided on one surface of a polarizing film containing iodine in a polyvinyl alcohol, and has a first cured layer and an adhesive layer which are composed of a cured product containing a curable composition of a polymerizable compound. The composition of the polymerizable compound contained in the curable composition is (A1) an oxetane compound having two or more oxetanyl groups, in an amount of 100% by mass based on the total amount of the polymerizable compound. (A2) an aliphatic epoxy compound having two or more epoxy groups (0 to 40% by mass), (A3) an alicyclic epoxy compound having two or more epoxy groups, 15 to 50% by mass, And (A4) 0 to 20% by mass of the aromatic epoxy compound having one or more aromatic rings. The polarizing plate according to claim 1, wherein the composition of the polymerizable compound contains: (A1) 35 to 70% by mass of an oxetane compound having two or more oxetanyl groups, (A2) 3 to 40% by mass of the aliphatic epoxy compound having two or more epoxy groups; (A3) 15 to 50% by mass of the alicyclic epoxy compound having two or more epoxy groups, and (A4) The aromatic epoxy compound of one or more aromatic rings is 0.1 to 20% by mass. The polarizing plate according to claim 1, wherein the composition of the polymerizable compound contains: (A1) 35 to 70% by mass of an oxetane compound having two or more oxetanyl groups, (A2) 0% by mass of an aliphatic epoxy compound having two or more epoxy groups; (A3) 15 to 50% by mass of an alicyclic epoxy compound having two or more epoxy groups; and (A4) having one The aromatic epoxy compound of the above aromatic ring is 0% by mass. The polarizing plate according to claim 3, wherein the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1) and (A3) have two or more The mass ratio (Wa3/Wa1) of the epoxy group-containing alicyclic epoxy compound (Wa3) is from 0.45 to 1.5. The polarizing plate according to claim 1, wherein the composition of the polymerizable compound contains: (A1) 35 to 70% by mass of an oxetane compound having two or more oxetanyl groups, (A2) 0% by mass of the aliphatic epoxy compound having two or more epoxy groups; (A3) 15 to 50% by mass of the alicyclic epoxy compound having two or more epoxy groups, and (A4) having The aromatic epoxy compound of one or more aromatic rings is 0.1 to 20% by mass. The polarizing plate according to claim 5, wherein the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1) and (A3) have two or more The mass ratio (Wa3/Wa1) of the epoxy group-containing alicyclic epoxy compound (Wa3) is 0.45 to 1.5, and the oxetane compound having 2 or more oxetanyl groups relative to (A1) The content (Wa1), (A4), the mass ratio (Wa4/Wa1) of the content (Wa4) of the aromatic epoxy compound having one or more aromatic rings is 0.05 to 0.5. The polarizing plate according to any one of claims 1 to 6, wherein the (A2) aliphatic epoxy compound having two or more epoxy groups is a compound represented by the formula (I). Wherein Z represents an alkylene group having 1 to 9 carbon atoms, an alkylene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a formula -C _m H _2m -Z ¹ -C _n H _2n - The base of the two valences (wherein -Z ¹ - represents -O-, -CO-O-, -O-CO-, -SO ₂ -, -SO- or -CO-, m and n are each independently The above represents an integer of 1 or more, and the total of m and n is 9 or less); the alicyclic epoxy compound having two or more epoxy groups in the above (A3) is a compound represented by the formula (II) In the formula, R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and when the alkyl group has a carbon number of 3 or more, it may have an alicyclic structure; and X represents an oxygen atom and a carbon number of 1 to Alkanediyl group of 6 or formula (IIa) to (IId) below Any of the divalent groups shown in the formula (wherein Y ¹ to Y ⁴ each independently represent an alkanediyl group having 1 to 20 carbon atoms, and when the alkanediyl group has a carbon number of 3 or more, may have an alicyclic structure , a and b each independently represent an integer of 0 to 20). The polarizing plate according to any one of claims 1 to 7, wherein the first transparent protective film is provided between the first cured material layer and the adhesive layer. The polarizing plate according to any one of the first to eighth aspects of the present invention, wherein the surface of the polarizing film opposite to the first cured material layer is formed of a cured product of a curable composition. The second cured layer is provided with a second transparent protective film. A curable composition comprising a curable composition containing a polymerizable compound, and comprising a composition of a polymerizable compound and (B) photocationic polymerization The initiator, wherein the composition of the polymerizable compound is 100% by mass based on the total amount of the polymerizable compound: (A1) an oxetane compound having two or more oxetanyl groups 35 to 70 (% by mass), (A2) 0 to 40% by mass of the aliphatic epoxy compound having two or more epoxy groups, and (A3) 15 to 50% by mass of the alicyclic epoxy compound having two or more epoxy groups, and A4) The aromatic epoxy compound having one or more aromatic rings is 0 to 20% by mass. The curable composition according to claim 10, wherein the composition of the polymerizable compound contains: (A1) an oxetane compound having two or more oxetanyl groups, 35 to 70 mass (A2) 3 to 40% by mass of the aliphatic epoxy compound having 2 or more epoxy groups; (A3) 15 to 50% by mass of the alicyclic epoxy compound having 2 or more epoxy groups, and ( A4) The aromatic epoxy compound having one or more aromatic rings is 0.1 to 20% by mass. The curable composition according to claim 10, wherein the composition of the polymerizable compound contains: (A1) an oxetane compound having two or more oxetanyl groups, 35 to 70 quality%, (A2) 0% by mass of an aliphatic epoxy compound having two or more epoxy groups; (A3) 15 to 50% by mass of an alicyclic epoxy compound having two or more epoxy groups; and (A4) having one The aromatic epoxy compound of the above aromatic ring is 0% by mass. The sclerosing composition according to claim 10, wherein the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1), (A3) has 2 The mass ratio (Wa3/Wa1) of the content (Wa3) of the alicyclic epoxy compound of the above epoxy group is 0.45 to 1.5. The curable composition according to claim 10, wherein the composition of the polymerizable compound contains: (A1) an oxetane compound having two or more oxetanyl groups, 35 to 70 mass %, (A2) 0% by mass of the aliphatic epoxy compound having two or more epoxy groups, (A3) 15 to 50% by mass of the alicyclic epoxy compound having two or more epoxy groups, and (A4) having The aromatic epoxy compound of one or more aromatic rings is 0.1 to 20% by mass. The curable composition according to claim 14, wherein the content (Wa1) of the oxetane compound having two or more oxetanyl groups (A1), (A3) has 2 More than one epoxy group The mass ratio (Wa3/Wa1) of the alicyclic epoxy compound (Wa3) is 0.45 to 1.5, and the content of the oxetane compound having 2 or more oxetanyl groups relative to (A1) (Wa1) (A4) The mass ratio (Wa4/Wa1) of the content (Wa4) of the aromatic epoxy compound having one or more aromatic rings is 0.05 to 0.5. The curable composition according to any one of claims 10 to 15, wherein the aliphatic epoxy compound having two or more epoxy groups (A2) is represented by the formula (I) Compound, Wherein Z represents an alkylene group having 1 to 9 carbon atoms, an alkylene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a formula -C _m H _2m -Z ¹ -C _n H _2n - The divalent base shown (wherein -Z ¹ - represents -O-, -CO-O-, -O-CO-, -SO ₂ -, -SO- or -CO-, m and n are each independently The above represents an integer of 1 or more, and the total of m and n is 9 or less); the alicyclic epoxy compound having two or more epoxy groups in the above (A3) is a compound represented by the formula (II). In the formula, R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and when the alkyl group has a carbon number of 3 or more, it may have an alicyclic structure; X represents an oxygen atom and a carbon number of 1 to 6 alkanediyl or the following formula (IIa) to (IId) Any one of the divalent groups shown in the formula (wherein Y ¹ to Y ⁴ each independently represent an alkanediyl group having 1 to 20 carbon atoms, and when the alkanediyl group has a carbon number of 3 or more, it may have an alicyclic structure. a and b each independently represent an integer of 0 to 20). A cured product comprising the curable composition according to any one of claims 10 to 16.