TW201538321A - Polarizing plate and liquid crystal panel - Google Patents

Abstract

The present invention provides a polarizing plate and a liquid crystal panel using the polarizing plate. The polarizing plate comprises: a polyvinyl alcohol-based polarizer and a first protection layer laminated on one surface of the polarizer via a first adhesive layer, wherein the first adhesive layer is a cured product of a non-solvent active energy ray-cured adhesive. The first protection layer is a methacrylate-based resin layer comprising 50 to 95 wt% of a first constitution unit represented by general formula (I), 0.1 to 20 wt% of a second constitution unit represented by general formula (II), and 0.1 to 49.9 wt% of a third constitution unit represented by general formula (III).

Description

Polarizer and LCD panel

The present invention relates to a polarizing plate in which a protective film is bonded to at least one surface of a polyvinyl alcohol-based polarizer, and a liquid crystal panel using the polarizing plate.

The polarizing plate is widely used as a polarized supply element of an image display device such as a liquid crystal display device or a polarized detecting element. The polarizing plate is generally a member of a protective film that is bonded to one surface or both surfaces of a polarizer using an adhesive.

Japanese Laid-Open Patent Publication No. 2013-033237 (Patent Document 1) discloses a film composed of a specific methacrylic resin (referred to as "acrylic thermoplastic resin" in Patent Document 1), and has heat resistance and moisture resistance. It is excellent in abrasion resistance, mechanical strength, adhesion to a polarizer, and optical isotropy, and can be used as a protective film for a polarizer.

The protective film described in Patent Document 1 is excellent in heat resistance, moisture resistance, scratch resistance, mechanical strength, and optical isotropic properties. However, the adhesion to the polarizer is not sufficient, for example, the polarizing plate is cut. When the size is specified, a defect in which the protective film is peeled off from the polarizer occurs at the end portion thereof. When the peeled polarizing plate is generated, it is easy to further peel off from the peeled portion, and the dichroic dye contained in the polarizing plate is detached from the peeled portion.

Therefore, the present invention is directed to a polarizing plate comprising a protective layer composed of a specific methacrylic resin as described in Patent Document 1, and an object thereof is to provide an improvement in adhesion between a polyvinyl alcohol-based polarizer and the protective film. a polarizing plate, and a liquid crystal panel using the polarizing plate.

The present invention provides the following polarizing plate and liquid crystal panel.

[1] A polarizing plate comprising: a polyvinyl alcohol-based polarizer; and a first protective layer laminated on a surface of the one side via a first adhesive; wherein the first adhesive layer is a solvent-free active energy ray a cured layer of a curable adhesive; the first protective layer is a layer containing a methacrylic resin having a following general formula (I): 50 to 95% by weight:

[In the formula (I), R ¹ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkylalkyl group having 4 to 12 carbon atoms, or a cycloalkane having 5 to 12 carbon atoms; a arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms or an alkoxy group having a halogen atom, a hydroxyl group, a nitro group, a carbon number of 1 to 12, and a carbon number of 1 to 12 The first constituent unit represented by the aryl group having 6 to 14 carbon atoms of at least one substituent group in the group, and 0.1 to 20% by weight of the following general formula (II):

[In the formula (II), R ² represents an arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms or an alkoxy group having a halogen atom, a hydroxyl group, a nitro group and a carbon number of 1 to 12; a aryl group having 6 to 14 carbon atoms of a group of at least one substituent group of a group having 1 to 12 carbon atoms and an arylalkyl group having 7 to 14 carbon atoms; and R ³ and R ⁴ each independently represent hydrogen a second structural unit represented by an atom, an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms, and 0.1 to 49.9% by weight of the following general formula (III):

[In the formula (III), R ⁵ represents a cycloalkyl group having 3 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms, a cycloalkylalkyl group having 4 to 12 carbon atoms or having a halogen atom, a hydroxyl group, or the like. a carbon having 1 to 12 carbon atoms of at least one substituent of a nitro group and an alkoxy group having 1 to 12 carbon atoms; and R ⁶ and R ⁷ each independently represent a hydrogen atom and an alkyl group having 1 to 12 carbon atoms; The third constituent unit represented by a group or an aryl group having 6 to 14 carbon atoms.

[2] The polarizing plate according to [1], wherein the aforementioned active energy The line hardening adhesive includes an active energy ray-curable epoxy compound.

[3] The aforementioned active energy ray-curable epoxy compound

The polarizing plate according to [1] includes a (meth)acrylic compound.

[6] The polarizing plate according to [1], wherein the active energy ray-curable adhesive comprises a (meth) acrylamide monomer having at least one (meth) acrylonitrile group and a guanamine bond in the molecule.

[7] The polarizing plate according to any one of [1], wherein the first protective layer is a film extending in at least one direction, and the stretching ratio is 1.2 times or more.

[8] The polarizing plate according to any one of [1], wherein the first protective layer is laminated on a surface of one side of the polyvinyl alcohol-based polarizer via the first adhesive layer. And a second protective layer containing a thermoplastic resin different from the methacrylic resin on the surface of the other side of the polyvinyl alcohol-based polarizer via a second adhesive layer.

[9] The polarizing plate according to any one of [1] to [8], further comprising an adhesive layer.

[10] The polarizing plate according to [9], wherein the adhesive layer is disposed on an outer surface of the first protective layer.

[11] The polarizing plate according to [9], wherein the adhesive layer is disposed on an outer surface of the second protective layer.

[12] A liquid crystal panel comprising: a liquid crystal cell and a matching The polarizing plate of any one of [1] to [11] which is provided on the surface of at least one side.

[13] The liquid crystal panel according to [12], wherein the liquid crystal cell is a liquid crystal cell of a transverse electric field effect mode (IPS mode).

In the present specification, the term "(meth)acrylic acid" means at least one selected from the group consisting of acrylic acid and methacrylic acid. The same applies to "(meth) acrylate" and "(meth) acryl thiol".

According to the present invention, it is possible to provide a polyvinyl alcohol-based polarizer and a heat-resistant property, moisture resistance, scratch resistance, mechanical strength, and optical isotropic property which are exhibited by the protective layer containing the specific methacrylic resin. A polarizing plate of the protective layer. This polarizing plate is suitable for use as a liquid crystal panel.

1, 2‧‧‧ polarizing plate

3‧‧‧LCD panel

10‧‧‧ polarizer

15‧‧‧1st adhesive layer

21‧‧‧1st protective layer

22‧‧‧2nd protective layer

25‧‧‧2nd adhesive layer

30‧‧‧Adhesive layer

40‧‧‧Liquid Crystal Unit

Fig. 1 is a schematic cross-sectional view showing an example of a layer configuration of a polarizing plate of the present invention.

Fig. 2 is a schematic cross-sectional view showing another example of the layer configuration of the polarizing plate of the present invention.

Fig. 3 is a schematic cross-sectional view showing an example of a layer configuration of a liquid crystal panel of the present invention.

<Polarizer>

Hereinafter, the polarizing plate of the present invention will be described in detail in the embodiment.

(1) Layer composition of polarizing plate

The polarizing plate of the present invention includes a polarizer and a first adhesive layer laminated on the surface of one side of the cured layer of the cured layer of the solvent-free active energy ray-curable adhesive (hereinafter also referred to as the present adhesive). The first protective layer containing a specific methacrylic resin (hereinafter, this methacrylic resin is also referred to as "methacrylic resin [A]"). An example of the layer configuration of the polarizing plate of the present invention is shown in Fig. 1. The polarizing plate 1 shown in Fig. 1 includes a polarizer 10, a first protective layer 21 laminated on one surface of the polarizer 10 via the first adhesive layer 15, and a second adhesive layer interposed therebetween. 25 is laminated on the second protective layer 22 on the other surface of the polarizer 10.

The polarizing plate of the present invention may or may not include the second protective layer 22 laminated on the other surface of the polarizing plate 10, without being limited to the example of FIG. When the second protective layer 22 is included, the protective layer may contain the methacrylic resin [A] in the same manner as the first protective layer 21, or may be composed of other different thermoplastic resins. Further, the second adhesive layer 25 may be formed of the same adhesive as the first adhesive layer 15, or may be formed of another different adhesive. The second protective layer 22 may be directly laminated on the surface of the polarizer 10 without interposing the second adhesive layer 25.

The polarizing plate of the present invention as shown in Fig. 1 may further include an adhesive layer 30. When the adhesive layer 30 is provided with both the first and second protective layers 21 and 22, it can be disposed on the outer surfaces of the first or second protective layers 21 and 22, and when the second protective layer 22 is not provided, for example, The polarizing plate 2 shown in FIG. 2 can be disposed on the outer surface (surface opposite to the first protective layer 21) of the polarizing plate 10. Further, although not shown, the polarizing plate of the present invention may have a coating layer on the outermost surface thereof in order to impart desired optical characteristics or other characteristics (Table Surface treatment layer).

(2) Polarizer

The polarizer 10 of a polyvinyl alcohol-based polarizer having a polyvinyl alcohol-based resin as a main component has a property of absorbing a linearly polarized light having a vibrating surface having a parallel optical axis and penetrating a vibrating surface having a vertical optical axis. The optical element may be, for example, a polyvinyl alcohol-based resin film in which a dichroic dye which is one-axis extension is adsorbed and aligned. As the dichroic dye system, iodine or a dichroic organic dye is used. The polyvinyl alcohol-based resin constituting the polarizer 10 may be vinyl acetate and other monomers copolymerizable therewith (for example, ethylene, an unsaturated carboxylic acid, etc.) in addition to polyvinyl alcohol which is a saponified product of polyvinyl acetate. a vinyl alcohol-based copolymer of a saponified product of a copolymer. The thickness of the polarizer 10 is usually about 2 to 40 μm.

The polarizer 10 can be, for example, a step of one-axis stretching through a polyvinyl alcohol-based resin film, a step of dyeing a dichromatic dye by dyeing a polyvinyl alcohol-based resin film with a dichroic dye, and a polycondensation of a dichroic dye. The vinyl alcohol-based resin film is produced by a step of treating with a boric acid aqueous solution and a step of washing with a boric acid aqueous solution and then washing with water. The dyeing of the dichroic dye can be carried out by immersing the film in an aqueous solution containing a dichroic dye, and the treatment with the aqueous boric acid solution can be carried out by immersing the membrane in an aqueous solution of boric acid.

The one-axis extension of the polyvinyl alcohol-based resin film can be carried out before dyeing of the dichroic dye, simultaneously with dyeing, or after dyeing. When the one-axis extension is performed after dyeing, the one-axis extension can be performed before boric acid treatment or boric acid treatment get on. Moreover, one-axis extension can be performed at these multiple stages.

Further, the polarizer 10 can be obtained by stretching and dyeing a laminate of a polyvinyl alcohol-based resin layer and a base film. In this case, the stretched and dyed polyvinyl alcohol-based resin layer becomes a polarizer. The laminate can be obtained, for example, by applying a polyvinyl alcohol-based resin to a base film. The base film laminated on the polarizer can be peeled off and used as a protective film. The magnification of the above extension is usually 3 to 7 times.

(3) The first protective layer

The first protective layer 21 is a layer containing the methacrylic resin [A] having the first, second, and third structural units represented by the above formulas (I), (II), and (III), respectively. A layer composed of the methacrylic resin [A] is preferable, and when the additive is contained, the resin component other than the additive is a layer composed of the methacrylic resin [A].

(3-1) The first constituent unit of the methacrylic resin [A]

The first constituent unit constituting the methacrylic resin [A] is a constituent unit represented by the above formula (I), and in the formula (I), R ¹ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkylalkyl group having 4 to 12 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms or having a halogen atom (F, An aryl group having 6 to 14 carbon atoms of at least one substituent group of a group of a group of a hydroxyl group, a nitro group, a hydroxy group, a nitro group, an alkoxy group having 1 to 12 carbon atoms, and an alkyl group having 1 to 12 carbon atoms . In the present specification, the alkyl group of the alkyl group, the arylalkyl group and the alkoxy group may be linear or branched.

The number of carbon atoms which may be an alkyl group of R ¹ (the same for the alkyl group which may be a substituent of the aryl group of R ¹ ) is preferably from 1 to 6, more preferably from 1 to 4. Specific examples of the alkyl group which may be R ¹ include a methyl group, an ethyl group, a n- or i-propyl group, a n-, an iso- or a 3-butyl group, a 2-ethylhexyl group, a decyl group, a fluorenyl group, Dodecyl. Among them, from the viewpoints of transparency and weather resistance of the methacrylic resin [A], it is preferably methyl, ethyl, n- or i-propyl, n-, iso- or 3-butyl, 2 Ethylhexyl, more preferably methyl.

The number of carbon atoms which may be a cycloalkylalkyl group of R ¹ is preferably from 5 to 10, more preferably from 6 to 8. Specific examples of the cycloalkylalkyl group which may be R ¹ include a cyclopentylmethyl group, a cyclopentylethyl group, a cyclohexylmethyl group, a cyclohexylethyl group and the like.

Specific examples of the cycloalkyl group which may be R ¹ include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, tricyclodecyl, bicyclooctyl, tricyclododecyl, isodecyl, adamantane Base, tetracyclododecyl. Among them, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a tricyclodecanyl group, a bicyclooctyl group, a tricyclododecyl group, and an isodecyl group are preferable.

Specific examples of the arylalkyl group which may be R ¹ include a benzyl group, a 1- or 2-phenylethyl group, a 3-phenylpropyl group, a 6-phenylhexyl group, and an 8-phenyloctyl group. Among them, a benzyl group, a 1- or 2-phenylethyl group, and a 3-phenylpropyl group are preferred. Specific examples of the aryl group which may be R ¹ include a phenyl group, a naphthyl group, and an anthracenyl group. Among them, a phenyl group is preferred.

An aryl group which may have the above-mentioned specific substituent of R ¹ , more preferably a phenyl group having a substituent, and specific examples thereof include 2,4,6-tribromophenyl, 2- or 4-chlorophenyl, 2- or 4-bromophenyl, 2- or 4-methylphenyl, 2- or 4-ethylphenyl, 2- or 4-methoxyphenyl, 2- or 4-nitrophenyl, 2,4,6-trimethylphenyl, of which 2,4,6-tribromophenyl is more preferred.

The content of the first constituent unit is 50 to 95% by weight, more preferably 60 to 92% by weight, still more preferably 70 to 90% by weight, more preferably 100 to 90% by weight, more preferably 70 to 90% by weight, more preferably 100% by weight of the methacrylic resin [A]. It is from 79 to 90% by weight. When the content of the first constituent unit is less than 50% by weight, it is disadvantageous in the surface of the total light transmittance and weather resistance of the methacrylic resin [A]. The methacrylic resin [A] may contain only one type of first constituent unit, or may contain two or more kinds.

The first constituent unit is derived from the following general formula (I'): The constituent unit of methacrylic acid or methacrylate shown. R ^{1 of the} formula (I') has the same meaning as R ^{1 of the} formula (I). Among the methacrylates, methyl methacrylate or benzyl methacrylate is preferably used from the viewpoint of transparency and weather resistance of the methacrylic resin [A].

(3-2) Second constituent unit of the methacrylic resin [A]

The second constituent unit constituting the methacrylic resin [A] is a constituent unit represented by the above formula (II), and in the formula (II), R ² represents an arylalkyl group having a carbon number of 7 to 14 and carbon. The aryl group of 6 to 14 or having an alkyl group selected from a halogen atom (F, Cl, Br or I atom), a hydroxyl group, a nitro group, an alkoxy group having 1 to 12 carbon atoms, a carbon number of 1 to 12, and a carbon number The aryl group having 6 to 14 carbon atoms of at least one substituent group of 7 to 14 arylalkyl groups. R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms.

Specific examples of the arylalkyl group which may be R ² include a benzyl group, a 1- or 2-phenylethyl group, a 3-phenylpropyl group, a 6-phenylhexyl group, and an 8-phenyloctyl group. Among them, from the viewpoint of heat resistance and low birefringence of the methacrylic resin [A], benzyl group is preferred.

Specific examples of the aryl group which may be R ² include a phenyl group, a naphthyl group, and an anthracenyl group. Among them, from the viewpoint of heat resistance and low birefringence of the methacrylic resin [A], a phenyl group is preferred.

The alkoxy group which may be a substituent of the aryl group of R ^{2 has} a carbon number of from 1 to 10, more preferably from 1 to 8. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a n- or iso-propoxy group, a n-, an iso- or a 3-butoxy group, a 2-ethylhexyloxy group, and a 1-anthracene group. Baseoxy. Specific examples of the alkyl group having 1 to 12 carbon atoms and the arylalkyl group having 7 to 14 carbon atoms which may be a substituent of the aryl group of R ² , and an alkyl group and carbon which may have a carbon number of 1 to 12 as R ¹ Specific examples of the arylalkyl group of 7 to 14 are the same.

The aryl group which may be the above-mentioned specific substituent of R ² is preferably a phenyl group having a substituent or a naphthyl group having a substituent, and a specific example thereof is an aryl group which may have a substituent of R ¹ The specific examples are the same.

The number of carbon atoms which may be an alkyl group of R ³ and R ⁴ is preferably from 1 to 6, more preferably from 1 to 4. Specific examples of the alkyl group which may be R ³ and R ⁴ include a methyl group, an ethyl group, a n- or i-propyl group, a n-, an iso- or a 3-butyl group, a 2-ethylhexyl group, a fluorenyl group, Mercapto, dodecyl. Among them, from the viewpoints of transparency and weather resistance of the methacrylic resin [A], it is preferably methyl, ethyl, n- or i-propyl, n-, iso- or 3-butyl, 2 Ethylhexyl, more preferably methyl.

Specific examples of the aryl group which may be R ³ and R ⁴ include a phenyl group, a naphthyl group, and an anthracenyl group. Among them, from the viewpoint of heat resistance and low birefringence of the methacrylic resin [A], a phenyl group is preferred.

R ³ and R ^{4 are} preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group, and more preferably a hydrogen atom.

The content of the second constituent unit is 0.1 to 20% by weight, more preferably 5 to 20% by weight, and still more preferably 7 to 18% by weight, based on 100% by weight of the methacrylic resin [A]. When the content of the second constituent unit is within this range, the transparency can be maintained and the heat resistance of the methacrylic resin [A] can be improved. The methacrylic resin [A] may contain only one type of second structural unit, or may contain two or more types.

The second constituent unit is derived from the following general formula (II'): A constituent unit of the N-substituted maleimide compound shown. R formula (II ') of the ^2, R ³ and R ^4, line ^2, R ^3, and R is the same meaning in the general formula (II) of R ^4. Among them, N-phenylmaleimide and N-benzyl are used from the viewpoints of heat resistance, low birefringence, and higher adhesion to the adhesive of the methacrylic resin [A]. Maleic imine is ideal.

(3-3) The third constituent unit of the methacrylic resin [A]

The third constituent unit constituting the methacrylic resin [A] is a constituent unit represented by the above formula (III), and in the formula (III), R ⁵ represents a hydrogen atom and a cycloalkyl group having 3 to 12 carbon atoms. An alkyl group having 1 to 12 carbon atoms, a cycloalkylalkyl group having 4 to 12 carbon atoms or an alkyl group having a halogen atom (F, Cl, Br or I atom), a hydroxyl group, a nitro group and a carbon number of 1 to 12 An alkyl group having 1 to 12 carbon atoms of at least one substituent group in the group of oxy groups. R ⁶ and R ⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms.

As a cycloalkyl group which may be R ⁵ , for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, tricyclodecyl, bicyclooctyl, tricyclododecyl, Isoindolyl, adamantyl, tetracyclododecyl. Among them, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group are preferable, and from the viewpoints of transparency, weather resistance, and low hygroscopicity of the methacrylic resin [A] More ideally, it is cyclohexyl.

The number of carbon atoms which may be an alkyl group of R ⁵ is preferably from 1 to 10, more preferably from 1 to 8. Specific examples of the alkyl group which may be R ⁵ include a methyl group, an ethyl group, a n- or i-propyl group, a n-, an iso- or a 3-butyl group, a n-pentyl group, a n-hexyl group, and a n-octyl group. Base, n-decyl, n-dodecyl, n-octadecyl, 2-ethylhexyl, 1-indenyl, 1-dodecyl. Among these, a methyl group, an ethyl group, and an iso-propyl group are preferable from the viewpoints of transparency and weather resistance of the methacrylic resin [A].

The number of carbon atoms which may be a cycloalkylalkyl group of R ⁵ is preferably from 5 to 10, more preferably from 6 to 8. Specific examples of the cycloalkylalkyl group which may be R ⁵ include a cyclopentylmethyl group, a cyclopentylethyl group, a cyclohexylmethyl group, a cyclohexylethyl group and the like.

The alkoxy group which may be a substituent of the aryl group of R ^{5 has} a carbon number of from 1 to 10, more preferably from 1 to 8. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a n- or iso-propoxy group, a n-, an iso- or a 3-butoxy group, a 2-ethylhexyloxy group, and a 1-anthracene group. Oxygen.

Specific examples of the alkyl group which may be the above-mentioned specific substituent of R ⁵ include dichloromethyl, trichloromethyl, trifluoroethyl and hydroxyethyl groups, of which trifluoroethyl group is preferred.

The number of carbon atoms which may be an alkyl group of R ⁶ and R ⁷ is preferably from 1 to 6, more preferably from 1 to 4. Specific examples of the alkyl group which may be R ⁶ and R ⁷ include a methyl group, an ethyl group, a n- or i-propyl group, a n-, an iso- or a 3-butyl group, a 2-ethylhexyl group, a decyl group, Mercapto, dodecyl. Among them, from the viewpoints of transparency and weather resistance of the methacrylic resin [A], it is preferably methyl, ethyl, n- or i-propyl, n-, iso- or 3-butyl, 2 Ethylhexyl, more preferably methyl.

Specific examples of the aryl group which may be R ⁶ and R ⁷ include a phenyl group, a naphthyl group, and an anthracenyl group. Among them, from the viewpoint of heat resistance and low birefringence of the methacrylic resin [A], a phenyl group is preferred.

R ⁶ and R ^{7 are} preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group, and more preferably a hydrogen atom.

The content of the third constituent unit is 0.1 to 49.9% by weight, more preferably 0.1 to 35% by weight, still more preferably 0.1 to 30% by weight, even more preferably 100% by weight of the methacrylic resin [A]. It is preferably from 0.1 to 15% by weight. When the content of the third constituent unit is in this range, The methacrylic resin [A] has both transparency and low hygroscopicity. The methacrylic resin [A] may contain only one type of third structural unit, or may contain two or more types.

The third constituent unit is derived from the following general formula (III'): A constituent unit of the N-substituted maleimide compound shown. R formula (III ') of the ^5, R ⁶ and R ^7, Department of general formula (III) of R ^5, the same meanings as R ⁶ and R ^7. Among them, from the viewpoint of weather resistance of the methacrylic resin [A], N-methyl maleimide, N-ethyl maleimide, N-isopropyl maleimide, N-cyclohexylmaleimide is preferred, and among these, N-cyclohexyl group is used from the viewpoint of low hygroscopicity of methacrylic resin [A] and higher adhesion to the present adhesive. Maleic imine is more ideal.

The total content of the second and third constituent units is preferably 5 to 50% by weight, more preferably 5 to 40% by weight, and still more preferably 10, when the methacrylic resin [A] is 100% by weight. Up to 35% by weight, more desirably 10 to 30% by weight, particularly desirably 15 to 30% by weight. When the total content is in this range, it is advantageous in terms of heat resistance, weather resistance, low hygroscopicity, optical properties, and the like of the methacrylic resin [A].

From the viewpoint of optical characteristics (for example, low birefringence and low photoelastic coefficient) of the methacrylic resin [A], the molar ratio of the content of the second constituent unit to the content of the third constituent unit is preferably more than 0. It is 15 or less, more preferably 10 or less.

When the methacrylic resin [A] is 100% by weight from the viewpoint of the optical properties of the methacrylic resin [A], the total content of the first, second, and third constituent units is preferably 80% by weight or more. .

(3-4) Other constituent units of the methacrylic resin [A]

The methacrylic resin [A] may contain other constituent units other than the first, second, and third constituent units. The other constituent unit is not particularly limited as long as it is a constituent unit derived from another monomer copolymerizable with the monomers forming the first, second, and third constituent units.

Specific examples of the above other monomers include: an aromatic vinyl group; an unsaturated nitrile; an acrylate having a cyclohexyl group, a benzyl group or an alkyl group having 1 to 18 carbon atoms; an olefin; a diene; a vinyl ether; a vinyl ester; Allyl ester or methyl allyl ester of saturated fatty acid monocarboxylic acid such as vinyl fluoride; allyl propionate; polyvalent (meth) acrylate; polyvalent aryl ester; epoxy propyl compound; unsaturated carboxylic acid . The other monomers may be used alone or in combination of two or more.

Specific examples of the aromatic vinyl group include styrene, α-methylstyrene, and divinylbenzene. Specific examples of the unsaturated nitrile include acrylonitrile, methacrylonitrile, ethacrylonitrile, and phenylacrylonitrile.

Specific examples of the acrylate include methyl acrylate, ethyl acrylate, n- or iso-propyl acrylate, n-, iso- or 3-butyl acrylate, n- or iso-amyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, cyclohexyl acrylate, benzyl acrylate.

Specific examples of the olefin include ethylene, propylene, isobutylene, and diisobutylene. Specific examples of the diene include butadiene and isoprene. Specific examples of the vinyl ether include methyl vinyl ether and butyl vinyl ether. Specific examples of the vinyl ester include vinyl acetate and vinyl propionate. Further, specific examples of the fluorinated ethylene include vinylidene fluoride.

Specific examples of the polyvalent (meth) acrylate include ethylene glycol (meth) acrylate, diethylene glycol (meth) acrylate, trimethylolpropane tri (meth) acrylate, hexane diol Di(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, bisphenol A ethylene oxide or propylene oxide adduct (meth) acrylate, di(meth) acrylate of ethylene oxide or propylene oxide adduct of halogenated bisphenol A, ethylene oxide or propylene oxide adduct of isocyanurate Di- or tri(meth)acrylate.

Specific examples of the polyvalent aryl compound include diallyl phthalate and triallyl isocyanurate. Specific examples of the epoxy propyl compound include glycidyl (meth)acrylate and allylepoxypropyl ether. Specific examples of the unsaturated carboxylic acid include acrylic acid, methylene succinic acid, maleic acid, fumaric acid, and the like. Among the above, as the other monomer, styrene or α-methylstyrene is preferably used.

From the viewpoint of low hygroscopicity of the methacrylic resin [A], the content of the other constituent unit is preferably 0.1 to 20% by weight, more preferably 0.1 to 20% by weight, based on 100% by weight of the methacrylic resin [A]. It is desirably from 0.1 to 15% by weight, more desirably from 0.1 to 10% by weight. Further, from the viewpoint of weather resistance, the content of other constituent units is preferably 10% by weight or less. More preferably, it is 7% by weight or less.

The methacrylic resin [A] including the first to third constituent units and any other constituent units contained therein may be composed of one type of copolymer including such a constituent unit, and for example, one or more constituent units may be used. It is composed of two or more kinds of copolymers of different types and contents.

(3-5) Method for Producing Methacrylic Resin [A]

The methacrylic resin [A] can be produced by the method described in the above Patent Document 1. Specifically, the methacrylic resin [A] can be prepared by radical polymerization of the monomer composition of each of the above constituent units. The monomer composition may contain a solvent or a polymerization initiator as needed.

(3-6) Physical properties and optical properties of methacrylic resin [A]

The weight average molecular weight Mw of the methacrylic resin [A] is converted into polymethyl methacrylate by GPC measurement from the viewpoint of the mechanical strength of the first protective layer 21 and the moldability of the methacrylic resin [A]. It is ideal for 3000 to 1000000, more ideal for 30,000 to 800000, and more ideal for 60,000 to 600,000. Molecular weight distribution (Mw/Mn) of the methacrylic resin [A], from the viewpoint of moldability of the methacrylic resin [A], conversion of polymethyl methacrylate by GPC measurement, from 1 to 10 Ideal, 1.1 to 7 is more ideal, and 1.2 to 5 is more ideal.

The glass transition temperature Tg of the methacrylic resin [A] is preferably from 120 to 180 ° C, more preferably from 130 to 180 ° C, from the viewpoint of heat resistance of the first protective layer 21.

The first protective layer 21 preferably has a tensile modulus of elasticity of from 1,000 to 5,000 MPa and preferably from 1,500 to 5,000 MPa from the viewpoint of the load force as a protective film. In addition, from the viewpoint of the protective polarizer at the time of the heat-resistant endurance test after the polarizing, the first protective layer 21, which is accompanied by the shrinkage of the polarizer at the time of curing of the adhesive, does not shrink due to heat, the first protective layer 21 The high temperature tensile modulus is preferably higher. Specifically, the tensile modulus at 80 ° C is preferably from 1,000 to 4,000 MPa, more preferably from 1,500 to 4,000 MPa.

The methacrylic resin [A] and the first protective layer 21 composed of the same are described in the above-mentioned Patent Document 1, and the photoelastic coefficient C _R measured by the method described in the document is defined by the document. The absolute value is 3.0 × 10 ^-12 Pa ^-1 or less, and may be 2.0 × 10 ^-12 Pa ^-1 or less, and further may be 1.0 × 10 ^-12 Pa ^-1 or less. In addition, according to the definition described in the document, the phase difference Re in the in-plane direction and the phase difference Rth in the thickness direction measured by the method described in the document are all 8 nm or less, 6 nm or less, and further 4 nm or less. Further, according to the definition described in the literature, the total light transmittance measured by the method described in the literature may be 85% or more, or may be 90% or more.

In this way, the methacrylic resin [A] constituting the first protective layer 21 is a resin having excellent optical characteristics such as low birefringence (optical isotropic property), and the first protective layer 21 containing the same is suitable as a polarizing plate. The protective layer is particularly a protective layer of a polarizing plate used as a liquid crystal panel of the IPS mode. The first protective layer 21 may be a protective layer disposed on the liquid crystal cell side of the polarizer 10 when the liquid crystal panel is used, or may be protected from the liquid crystal cell side. In particular, the first protective layer 21 is a protective layer disposed on the liquid crystal cell side of the polarizer 10, and is a polarizer disposed on the polarizing plate on the viewing side of the liquid crystal cell and a polarizing plate disposed on the back side. In the cross Nicol formed between the polarizers, the first protective layer 21 having excellent optical characteristics such as low birefringence (optical isotropic) is disposed, which is advantageous for identification of the liquid crystal display device. Increase in sex. In addition, when the first protective layer 21 composed of the methacrylic resin [A] is disposed as a protective layer on the liquid crystal cell side of the polarizer 10, the low photoelasticity is exhibited as described above, for example, in a high temperature environment. In a high-temperature, high-humidity environment, even when a bending stress due to bending of the liquid crystal cell and a compressive stress accompanying thermal contraction of the polarizer 10 are applied, the low birefringence is continuously exhibited, and the visibility of the liquid crystal display device is maintained. advantageous. However, when the second protective layer 22 is composed of the methacrylic resin [A] described above, the second protective layer 22 is a protective layer disposed on the liquid crystal cell side of the polarizer 10, and of course, it may be the same as described above. Effect.

(3-7) Composition of the first protective layer

The first protective layer 21 may contain the methacrylic resin [A], preferably a methacrylic resin [A], or a resin component other than the additive may be a methacrylic resin when the additive is contained. A] The film formed. The film formation can be carried out by a conventionally known method such as a melt extrusion method, a hot press molding method, an injection molding method, or a solvent casting method.

The first protective layer 21 may be a stretched film extending in at least one direction. The mechanical strength of the first protective layer 21 can be increased by stretching. When the stretched film composed of the methacrylic resin [A] is generally subjected to elongation treatment, The adhesion to the adhesive layer is lowered. According to the present invention, even when the first protective layer 21 is a stretched film, good adhesion can be obtained.

Examples of the elongation treatment include, for example, one-axis extension, two-axis extension, and the like. The direction of extension may be, for example, a mechanical flow direction (MD) of the unstretched film, a direction perpendicular thereto (TD), a direction inclined with respect to the mechanical flow direction, and the like. The two-axis extension can be a two-axis extension extending in two extending directions at the same time, and can also extend in the specified direction and then extend in two directions in sequence. The extension treatment, for example, using two or more pairs of clamping rollers whose rotational speed is increased on the outlet side, extends in the longitudinal direction (mechanical flow direction: MD), and the both ends of the unstretched membrane are held by the chuck and vertically mechanically flowed. Direction (TD) expansion is carried out.

The stretching ratio of the stretching treatment is usually 1.1 times or more, and even if the stretching ratio is 1.2 times or more, according to the present invention, good adhesion to the adhesive layer can be obtained. The stretching ratio is usually 5 times or less, and preferably 3.5 times or less. Further, the stretching ratio of the biaxial stretching means the stretching ratio in the direction in which the stretching ratio is large.

The thickness of the first protective layer 21 is, for example, about 1 to 200 μm, and is preferably from 5 to 150 μm, more preferably from 10 to 120 μm, from the viewpoint of the thickness of the polarizing plate and the strength and handleability of the first protective layer 21.

The first protective layer 21 may contain a thermoplastic resin other than the methacrylic resin [A]. Specific examples of the other thermoplastic resin include olefin-based polymers such as polyethylene, polypropylene, and ethylene-propylene copolymer; halogen-containing polymers such as vinyl chloride and vinyl chloride resins; polystyrene and styrene-methyl Methyl acrylate copolymer, styrene-acrylonitrile copolymer, etc. Styrene polymer; polyester such as polyethylene terephthalate; polyarylate; polycarbonate; polyamine; polyacetal. However, in order to ensure heat resistance, moisture resistance, damage resistance, mechanical strength, optical isotropic property, etc. of the first protective layer 21 derived from the methacrylic resin [A], the content of the other thermoplastic resin is methyl When the content of the acrylic resin [A] is 100% by weight, it is preferably from 0 to 25% by weight, more preferably from 0 to 10% by weight.

Further, the first protective layer 21 may contain one or more kinds of additives such as rubber particles, a lubricant, a dispersant, a heat stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent, and an antioxidant.

The blending of the rubber particles is advantageous in that the film forming property of the methacrylic resin [A], the impact resistance of the first protective layer 21, and the surface smoothness of the first protective layer 21 are improved. The rubber particles include a layer showing rubber elasticity (hereinafter also referred to as a rubber elastic layer).

The rubber particles may be particles composed only of a rubber elastic layer, or may be particles having a multilayer structure of a rubber elastomer layer and other layers. Examples of the polymer contained in the rubber elastomer layer include an olefin-based elastomeric polymer, a diene-based elastomeric polymer, a styrene-diene-based elastomeric copolymer, and an acrylic elastomeric polymer. Among them, from the viewpoint of light resistance and transparency, an acrylic elastic polymer is preferred.

The acrylic elastomeric polymer is mainly composed of an alkyl acrylate, that is, a copolymer containing 50 parts by weight or more of a constituent unit derived from an alkyl acrylate based on the total amount of the monomers. The acrylic elastomeric polymer may be a homopolymer of an alkyl acrylate, or may comprise 50 or more by weight of a constituent unit derived from an alkyl acrylate and a composition derived from another polymerizable monomer. A copolymer of less than 50 parts by weight of the unit.

As the alkyl acrylate constituting the acrylic elastomer, the alkyl group usually has a carbon number of 4 to 8. Examples of the other polymerizable monomer include alkyl methacrylate such as methyl methacrylate and ethyl methacrylate; styrene monomers such as styrene and alkyl styrene; and acrylonitrile and a monofunctional monomer such as an unsaturated nitrile such as methacrylonitrile, or an ethylenic ester of an unsaturated carboxylic acid such as allyl (meth)acrylate or methyl allyl (meth)acrylate; a polyfunctional monomer such as a dibasic acid of a dibasic acid such as diallyl diol dicarboxylate; or an unsaturated carboxylic acid diester of a diol such as an alkanediol di(meth)acrylate.

The rubber particles containing the acrylic elastomer polymer are preferably particles having a multilayer structure of a layer having an acrylic elastomer polymer. Specifically, for example, a two-layer structure having a hard polymer layer mainly composed of an alkyl methacrylate on the outer side of the layer of the acrylic elastomer polymer or a layer of the layer other than the acrylic elastomer polymer A three-layer structure of a hard polymer layer mainly composed of an alkyl acrylate.

The monomer composition of the alkyl methacrylate-based polymer constituting the hard polymer layer formed on the outer side or the inner side of the layer of the acrylic elastomer polymer, using a monomer composition mainly composed of methyl methacrylate ideal. The acrylic rubber particles having such a multilayer structure can be produced, for example, by the method described in JP-A-55-27576.

The rubber particles are included in the outermost rubber elastic layer from the viewpoints of the film forming property of the methacrylic resin [A], the impact resistance of the first protective layer 21, and the surface smoothness of the first protective layer 21 ( Eg C The particles composed of the layer of the olefinic elastomeric polymer have an average particle diameter of preferably from 10 to 500 nm, more preferably from 10 to 350 nm. The average particle diameter is more preferably 30 nm or more, further 50 nm or more, further preferably 300 nm or less, and further 280 nm or less.

The average particle diameter of the particles composed of the outermost rubber elastic layer of the rubber particles was measured by the following method. The rubber particles and the methacrylic resin [A] were mixed and thinned, and the cross section was dyed with an aqueous solution of cerium oxide. It was observed that only the rubber elastomer layer was colored and substantially rounded, and the mother layer of the methacrylic resin [A] was observed. Not stained. Therefore, from the film cross section thus dyed, a sheet was prepared using a microtome or the like and observed with an electron microscope. Then, 100 dyed rubber particles were taken out at random, and the respective particle diameters (to the diameter of the outer shell of the rubber elastic layer) were calculated, and the average number of the numbers was defined as the average particle diameter. As a result of measurement by such a method, the above average particle diameter obtained is a number average particle diameter.

The outermost layer is a hard polymer mainly composed of methyl methacrylate, and when rubber particles surrounded by a rubber elastomer layer are mixed with the methacrylic resin [A] of the precursor, the outermost layer of the rubber particles is The parent methacrylic resin [A] is mixed. Therefore, the cross section was stained with cerium oxide, and when observed by an electron microscope, the rubber particles were observed to be particles in a state in which the outermost layer was removed. Specifically, when the inner layer is an acrylic elastic polymer and the outer layer is a rubber particle having a two-layer structure of a hard polymer mainly composed of methyl methacrylate, it is observed that the acrylic elastic polymer portion of the inner layer is dyed. A single layer of structured particles. Moreover, the innermost layer is a hard polymer mainly composed of methyl methacrylate, and the intermediate layer is an acrylic elastic polymerization. When the outermost layer is a rubber particle having a three-layer structure of a hard polymer mainly composed of methyl methacrylate, it is observed that the central portion of the innermost layer is not dyed, and only the acrylic elastic polymer portion of the intermediate layer is Particles of the 2-layer structure dyed.

The rubber particles are blended to form the methyl group of the first protective layer 21 from the viewpoints of the film forming property of the methacrylic resin [A], the impact resistance of the first protective layer 21, and the surface smoothness of the first protective layer 21. The total amount of the acrylic resin [A] is preferably from 3 to 60% by weight, more preferably 45% by weight or less, still more preferably 35% by weight or less. When the rubber particles are more than 60% by weight, the dimensional change of the first protective layer 21 is increased, and the heat resistance is lowered. On the other hand, when the rubber particles are less than 3% by weight, the heat resistance of the first protective layer 21 is good, but the winding property is poor at the time of film formation, and the productivity may be lowered.

Further, when rubber particles having a multilayer structure having a rubber elastomer layer and other layers are used as the rubber particles, the weight of the rubber elastic layer and the portion of the inner layer is the weight of the rubber particles. For example, when the acrylic rubber particles having the above three-layer structure are used, the total weight of the acrylic elastic polymer portion of the intermediate layer and the hard polymer portion mainly composed of methyl methacrylate of the innermost layer is the weight of the rubber particles. When the acrylic rubber particles having the three-layer structure are dissolved in acetone, the acrylic elastomeric polymer portion of the intermediate layer and the hard polymer portion mainly composed of methyl methacrylate in the innermost layer remain as insoluble components, which is easy. The weight ratio of the intermediate layer to the innermost layer in the acrylic rubber particles having a three-layer structure was determined.

When the first protective layer 21 contains rubber particles, the resin composition containing the methacrylic resin [A] and the rubber particles used for the production of the first protective layer 21 can be made of methacrylic resin [A]. In addition to the rubber particles being melt-kneaded or the like, a rubber particle may be produced first, and in the presence of the rubber particles, a monomer composition which is a raw material of the methacrylic resin [A] may be polymerized.

(4) The first adhesive layer

The first adhesive layer 15 is a layer for bonding the polarizer 10 and the first protective layer 21, and is a solvent-free active which is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. An energy ray hardenable adhesive is formed. Therefore, the first adhesive layer 15 is a cured layer of the active energy ray-curable adhesive. By using a solventless active energy ray-curable adhesive, the adhesion between the polarizer 10 and the first protective layer 21 can be improved. On the other hand, when a solvent (especially an organic solvent) is contained in the active energy ray-curable adhesive, even if the curable component contained in the adhesive is the same, sufficient adhesion cannot be obtained, and the polarizing plate is cut into a designated one. When it is large, at the end, the defect that the first protective layer 21 is peeled off from the polarizer 10 is likely to occur.

The term "solvent-free" as used in the present specification means that the solvent is not actively added. Specifically, when the total amount of the solventless active energy ray-curable adhesive is 100% by weight, the content of the inorganic and organic solvent is 5 Below weight%.

As a solventless active energy ray-curable adhesive, For example, a cationically polymerizable material containing a cationically polymerizable curable component such as an active energy ray-curable epoxy compound (hereinafter also referred to as an epoxy compound), and a (meth)acrylic compound may be used. The radical polymerizable property of a radically polymerizable curable component as a main component, a cationically polymerizable curable component such as an epoxy compound, and a (meth)acrylic compound, etc. A mixed type of both components. The adhesion between the polarizer 10 and the first protective layer 21 is particularly effective, and the transparency, mechanical strength, thermal stability, and the like of the adhesive layer are also excellent. Therefore, it is preferable that the cationic polymerizable property and the aforementioned The radical polymerizable one is more preferably a cationic polymerizable one.

(4-1) Cationic polymerizable curable component

The cationically polymerizable curable component is, for example, an epoxy compound. The epoxy compound refers to a compound having one or more molecules, preferably two or more epoxy groups in the molecule, and is curable by cationic polymerization by irradiation with an active energy ray. The epoxy compound may be used alone or in combination of two or more.

From the viewpoints of adhesion between the polarizer 10 and the first protective layer 21, weather resistance, refractive index, cationic polymerizability, and the like, the epoxy compound is preferably one having no aromatic ring in the molecule. As such an epoxy compound, for example, a hydrogenated epoxy compound (epoxypropyl ether of a polyhydric alcohol having an alicyclic ring), an aliphatic epoxy compound, or an alicyclic epoxy compound. In the viewpoint of the adhesion between the polarizer 10 and the first protective layer 21, the cationically polymerizable solvent-free active energy ray-curable adhesive contains an alicyclic ring. Epoxy compounds are preferred.

The hydrogenated epoxy compound is obtained by reacting epichlorohydrin in an alicyclic polyol obtained by hydrogenating an aromatic ring of an aromatic polyol. Specific examples of the aromatic polyol include: bisphenol type compounds such as bisphenol A, bisphenol F, and bisphenol S; phenol novolac resin, cresol novolac resin, hydroxybenzaldehyde phenol novolac A novolac resin such as a resin; a polyfunctional compound such as tetrahydroxydiphenylmethane, tetrahydroxybenzophenone or polyvinylphenol. Desirable in hydrogenated epoxy compounds are, for example, diethylene oxide propyl ethers of hydrogenated bisphenol A.

Specific examples of the aliphatic epoxy compound include a polyepoxypropyl ether of an aliphatic polyol or an alkylene oxide adduct thereof. More specifically, for example, diepoxypropyl ether of 1,4-butanediol; diepoxypropyl ether of 1,6-hexanediol; triepoxypropyl ether of glycerol; Triepoxypropyl ether of propane; diepoxypropyl ether of polyethylene glycol; diepoxypropyl ether of propylene glycol; by aliphatic polyol addition of ethylene glycol, propylene glycol or glycerol A polyepoxy propyl ether of a polyether polyol obtained by one or two or more kinds of alkylene oxides (ethylene oxide or propylene oxide).

The alicyclic epoxy compound is an epoxy compound having one or more epoxy groups bonded to an alicyclic ring in the molecule. The "epoxy group bonded to the alicyclic ring" means a bridged oxygen atom -O- of the structure shown by the following formula. In the following formula, m is an integer of 2 to 5.

The group in which one or a plurality of hydrogen atoms in the above formula (CH ₂ ) _m are removed is bonded to a compound having another chemical structure, and can be an alicyclic epoxy compound. 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. In the alicyclic epoxy compound, a compound having an oxabicyclohexane ring (in the above formula m=3) or an oxabicycloheptane ring (in the above formula m=4) is used, since the polarizer 10 can be imparted thereto. It is preferable because it has good adhesion to the first protective layer 21. Specific examples of the alicyclic epoxy compound to be used are exemplified below, but are not limited to these compounds.

(a) an epoxycyclohexylcarboxylic acid epoxycyclohexyl methyl ester represented by the following formula (IV);

In the formula (IV), R ⁸ and R ⁹ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.

(b) an epoxycyclohexylcarboxylic acid of an alkanediol represented by the following formula (V);

In the formula (V), R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and n represents an integer of 2 to 20.

(c) an epoxycyclohexylmethyl ester of a dicarboxylic acid represented by the following formula (VI);

In the formula (VI), R ¹² and R ¹³ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and p represents an integer of 2 to 20.

(d) an epoxycyclohexyl methyl ether of polyethylene glycol represented by the following formula (VII);

In the formula (VII), R ¹⁴ and R ¹⁵ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and q represents an integer of 2 to 10.

(e) an epoxycyclohexyl methyl ether of an alkanediol represented by the following formula (VIII);

In the formula (VIII), R ¹⁶ and R ¹⁷ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and r represents an integer of 2 to 20.

(f) a diepoxytrispirocyclic compound represented by the following formula (IX);

In the formula (IX), R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.

(g) a diepoxymonospirocyclic compound represented by the following formula (X);

In the formula (X), R ²⁰ and R ²¹ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.

(h) a vinylcyclohexene diepoxide represented by the following formula (XI);

In the formula (XI), R ²² represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.

(i) an epoxycyclopentyl ether represented by the following formula (XII);

In the formula (XII), R ²³ and R ²⁴ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.

(j) a dicyclooxy tricyclodecane represented by the following formula (XIII);

In the formula (XIII), R ²⁵ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.

Among the alicyclic epoxy compounds exemplified above, it is preferred to use the following alicyclic epoxy compound from the viewpoint of adhesion between the polarizer 10 and the first protective layer 21 and ease of availability.

(IV-a) an esterified product of 7-oxabicyclo[4.1.0]heptane-3-carboxylic acid with (7-oxabicyclo[4.1.0]heptan-3-yl)methanol [in formula (IV), Compound with R ⁸ =R ⁹ =H, compound name: 3', 4'-epoxycyclohexenecarboxylic acid 3,4-epoxycyclohexenylmethyl ester], (IV-b) 4-methyl Esterified product of -7-oxabicyclo[4.1.0]heptane-3-carboxylic acid with (4-methyl-7-oxabicyclo[4.1.0]heptan-3-yl)methanol [Formula (IV) , R ⁸ =R ⁹ =4-CH ₃ compound], (Va) 7-oxabicyclo[4.1.0]heptane-3-carboxylic acid ester with 1,2-ethanediol [Formula (V) ), a compound of R ¹⁰ =R ¹¹ =H, n=2], and an esterified product of (VI-a)(7-oxabicyclo[4.1.0]heptan-3-yl)methanol with adipic acid (VI), R ¹² =R ¹³ =H, p=4 compound], (VI-b)(4-methyl-7-oxabicyclo[4.1.0]heptan-3-yl)methanol and hexamethylene Acid esterified compound [Compound of formula (VI), R ¹² = R ¹³ = 4-CH ₃ , p = 4], (VIII-a) (7-oxabicyclo[4.1.0]heptan-3-yl An esterified product of methanol and 1,2-ethanediol [a compound of the formula (VIII), R ¹⁶ = R ¹⁷ = H, r = 2].

The epoxy equivalent of an epoxy compound, usually 30 to 3000 The g/equivalent is more preferably in the range of 50 to 1500 g/equivalent. When the epoxy equivalent is less than 30 g/eq, the adhesion between the polarizer 10 and the first protective layer 21 is low, and the flexibility of the adhesive layer after curing is low. On the other hand, when it exceeds 3000 g/eq, there is a case where the compatibility with other components contained in the adhesive is low.

From the viewpoint of the adhesion between the polarizer 10 and the first protective layer 21, when the total amount of the hardening component contained in the cationically polymerizable solventless active energy ray-curable adhesive is 100% by weight, the epoxy The content of the compound is preferably 40% by weight or more, more preferably 50% by weight or more, and still more preferably 60% by weight or more.

As a commercial product of an epoxy compound, for example, "jER" series by Mitsubishi Chemical Corporation, "EPICLON" by DIC (share), "EPOTOHTO (registered trademark)" by Nippon Steel & Metal Chemical Co., Ltd., (share) ADEKARESIN (registered trademark) manufactured by ADEKA, "DENACOL (registered trademark)" by NAGASE CHEMTEX Co., Ltd., "DOWEPOXY" manufactured by Dow Chemical Co., Ltd., and "TEPIC (registered trademark)" manufactured by Nissan Chemical Industries Co., Ltd. Commercial products such as "CELLOXIDE" series and "CYCLOMER" manufactured by DAICEL Co., Ltd., and "CYRACURE UVR" series manufactured by Dow Chemical Co., Ltd., etc., are commercially available as alicyclic epoxy compounds.

(4-2) Cationic polymerization initiator

The cationically polymerizable and mixed solvent-free active energy ray-curable adhesive usually contains a cationic polymerization initiator, and preferably contains a photocationic polymerization initiator. Photocationic polymerization initiator, by visible light, A cationic species or a Lewis acid is generated by irradiation of an active energy ray such as ultraviolet light, X-rays, or an electron beam to initiate polymerization of an epoxy group.

By using a photocationic polymerization initiator, the method of hardening the adhesive by irradiation with an active energy ray can be cured at room temperature, and the heat resistance of the polarizer 10 or the deformation due to expansion can be reduced, and the film can be well adhered. It is advantageous at the point between the membranes. Further, the photocationic polymerization initiator is excellent in storage stability and workability even when it is mixed with an epoxy compound by using light as a catalyst.

Examples of the photocationic polymerization initiator include an aromatic diazonium salt; an aromatic iodonium salt; an onium salt such as an aromatic sulfonium salt; and an iron-aromatic hydrocarbon complex.

Specific examples of the aromatic diazonium salt include benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and benzenediazonium hexafluoroborate.

Specific examples of the aromatic iodonium salt include diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and di(4- Nonylphenyl) iodonium hexafluorophosphate.

Specific examples of the aromatic sulfonium salt include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, 4,4' - bis(diphenylthioindenyl) diphenyl sulfide bis(hexafluorophosphate), 4,4'-bis[bis(β-hydroxyethoxy)phenylthioindolyl] diphenyl sulfide double ( Hexafluoroantimonate), 4,4'-bis[bis(β-hydroxyethoxy)phenylsulfonyl]diphenyl sulfide bis(hexafluorophosphate), 7-[di(p-tolyl) Thiothio]-2-isopropylthioxanthone hexafluoroantimonate, 7-[bis(p-tolyl)thiol]-2- Isopropyl thioxanthone tetrakis(pentafluorophenyl)borate, 4-phenylcarbonyl-4'-diphenylthioindenyl diphenyl sulfide hexafluorophosphate, 4-(p-but-3-butyl Phenylcarbonyl)-4'-diphenylsulfanyl-diphenyl sulfide hexafluoroantimonate, 4-(p-tert-butylphenylcarbonyl)-4'-bis(p-tolyl)sulfide Mercapto-diphenyl sulfide tetrakis(pentafluorophenyl)borate.

Further, specific examples of the iron-aromatic complex include xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, and Toluene-cyclopentadienyl iron (II)-tris(trifluoromethylsulfonyl) methanide.

The cationic polymerization initiator may be used alone or in combination of two or more. Among them, the aromatic sulfonium salt is preferred because it has ultraviolet absorbing properties in a wavelength region of 300 nm or more, and therefore has good curability and can provide a cured product having good mechanical strength and adhesion strength.

The amount of the cationic polymerization initiator to be added is usually from 0.5 to 20 parts by weight, preferably from 1 to 15 parts by weight, per 100 parts by weight of the cationically polymerizable curable component such as an epoxy compound. When the compounding amount of the cationic polymerization initiator is less than 0.5 part by weight, the hardening becomes insufficient. The mechanical strength of the subsequent layer or the adhesion between the polarizer 10 and the first protective layer 21 tends to decrease. In addition, when the amount of the cationic polymerization initiator is more than 20 parts by weight, the ionic substance in the cured product increases, and the hygroscopicity of the cured product increases, and the durability of the polarizing plate may be lowered.

(4-3) Radical polymerizable curable component

As a radically polymerizable curable component, for example, it has an ethylene property. A compound that saturates a bond, and the like. Examples of the compound having an ethylenically unsaturated bond include a (meth)acrylic compound and a vinyl compound.

Examples of the vinyl compound include styrene, styrenesulfonic acid, vinyl acetate, vinyl propionate, and N-vinyl-2-pyrrolidone.

The (meth)acrylic compound is, for example, a (meth) acrylate monomer having at least one (meth) acryloxy group in the molecule, and having at least one (meth) acryl fluorenyl group and decylamine in the molecule. The (meth)acrylic acid oligomer having at least two (meth)acryloyl groups in the molecule obtained by reacting a (meth)acrylamide monomer and two or more functional group-containing compounds obtained by reacting ( Methyl) propylene fluorenyl compound. The (meth)acrylic acid oligomer is preferably a (meth) acrylate oligomer having at least two (meth) acryloxy groups in the molecule. The (meth)acrylic compound may be used alone or in combination of two or more. The radical polymerizable and mixed solvent-free active energy ray-curable adhesive preferably contains (meth)acryl oxime. Amine monomer.

As the (meth) acrylate monomer, for example, a monofunctional (meth) acrylate monomer having one (meth) propylene fluorenyloxy group in the molecule and two (meth) acryloxy groups in the molecule A bifunctional (meth) acrylate monomer or a polyfunctional (meth) acrylate monomer having three or more (meth) acryloxy groups in the molecule.

Examples of the monofunctional (meth) acrylate monomer include tetramethylammonium (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2- or 3-hydroxypropyl (meth) acrylate. , 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, (meth)acrylic acid Isobutyl ester, 3 butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, (methyl) Benzyl acrylate, isodecyl (meth)acrylate, phenoxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate Ester, ethyl carbitol (meth) acrylate, trimethylolpropane mono (meth) acrylate, neopentyl alcohol mono (meth) acrylate, phenoxy polyethylene glycol (methyl) Acrylate and the like.

As the monofunctional (meth) acrylate monomer, a carboxyl group-containing (meth) acrylate monomer can be used. As a carboxyl group-containing (meth) acrylate monomer, for example, 2-(meth) propylene methoxyethyl phthalic acid, 2-(meth) propylene methoxyethyl hexahydrophthalic acid, Carboxyethyl (meth)acrylate, 2-(meth)acryloxyethyl succinic acid, N-(methyl)propenyloxy-N',N'-dicarboxymethyl-p-phenylene Diamine and 4-(meth)acryloxyethyltrimellitic acid and the like.

As a difunctional (meth) acrylate monomer, for example, an alkanediol di(meth)acrylate, a polyoxyalkylene glycol di(meth)acrylate, a halogen-substituted alkanediol di(methyl) ) acrylates, di(meth) acrylates of aliphatic polyols, di(meth) acrylates of hydrogenated dicyclopentadiene or tricyclodecane dialkyl alcohol, dioxane diol or two Di(meth) acrylates of oxane dialtanols, di(meth) acrylates of bisphenol A or alkylene oxide adducts of bisphenol F, epoxy groups of bisphenol A or bisphenol F Di(meth)acrylates and the like.

More specific examples of the difunctional (meth) acrylate monomer, such as ethylene glycol di(meth) acrylate, 1,3-butylene glycol di(methyl) Acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl Diol (meth) acrylate, trimethylolpropane di (meth) acrylate, neopentyl alcohol di (meth) acrylate, di-trimethylol propane di (meth) acrylate, Diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di( Methyl) acrylate, polypropylene glycol di(meth) acrylate, polybutylene diol di(meth) acrylate, silicone di(meth) acrylate, hydroxytrimethyl acetic acid neopentyl diester Di(meth)acrylate, 2,2-bis[4-(methyl)propenyloxyethoxyethoxyphenyl]propane, 2,2-bis[4-(methyl)propene oxime Oxyethoxyethoxycyclohexyl]propane, hydrogenated dicyclopentadienyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, 1,3-dioxane- 2,5-diyldi(meth)acrylate [alias: dioxanediol di(meth)acrylate] An acetal of hydroxytrimethylacetaldehyde and trimethylolpropane [chemical name: 2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl- Di(meth)acrylate of 1,3-dioxane], tris(hydroxyethyl)isocyanurate di(meth)acrylate, and the like.

The trifunctional or higher (meth) acrylate monomer is glycerol tri(meth) acrylate, trimethylolpropane tri(meth) acrylate, di-trimethylolpropane tri ( Methyl) acrylate, di-trimethylolpropane tetra(meth) acrylate, neopentyl alcohol tri(meth) acrylate, neopentyl alcohol tetra (meth) acrylate, dipentaerythritol Poly(methyl) groups of trifunctional or higher aliphatic polyols such as tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate Acrylate In addition to the above, other poly(meth)acrylates of a halogen-substituted polyol having a trifunctional or higher group, a tri(meth)acrylate of an alkylene oxide adduct of glycerin, and a ring of trimethylolpropane Tris(meth)acrylate of an oxane adduct, 1,1,1-tris[(meth)acryloxyethoxyethoxyethoxy]propane, tris(hydroxyethyl)isocyanurate Tris(meth)acrylates and the like.

As a (meth) acrylamide monomer having at least one (meth) acrylonitrile group and a guanamine bond in the molecule, for example, N-hydroxyethyl (meth) acrylamide and N-methylol ( N-hydroxyalkyl (meth) acrylamide monomer such as methyl) acrylamide; N,N-dihydroxyethyl(meth) acrylamide and N,N-dimethylol (methyl) N,N-dihydroxyalkyl (meth) acrylamide monomer such as acrylamide; N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (methyl) N-alkoxyalkyl (meth) acrylamide monoamine such as acrylamide, N-methoxyethyl (meth) acrylamide and N-ethoxyethyl (meth) acrylamide N,N-dimethoxymethyl(meth)acrylamide, N,N-diethoxymethyl(meth)acrylamide, N,N-dimethoxyethyl (A N,N-dialkoxyalkyl (meth) acrylamide monomer such as acrylamide and N,N-diethoxyethyl (meth) acrylamide; N-methyl ( N-monoalkyl (meth) propylene such as methyl acrylamide, N-isopropyl acrylamide, N-butyl (meth) acrylamide, and N-hexyl (meth) acrylamide Indoleamine monomer; N,N-dimethyl(meth)acrylamide and N,N- Ethyl N,N-dialkyl(meth)acrylamide monomer such as (meth)acrylamide; aminomethyl (meth) acrylamide and aminoethyl (meth) acrylamide N-aminoalkyl (meth) acrylamide monomer; N-thiol alkane such as thiol methyl (meth) acrylamide and thiol ethyl (meth) acrylamide a base (meth) acrylamide monomer; and N-propylene decylmorpholine, N-propylene hydrazinopiperidine, N-methyl acrylonitrile piperidine, and N-propenylpyrrolidine (Pyrrolidine) A (meth) acrylamide monomer having an aliphatic heterocyclic structure or the like.

A commercially available product can be used as the (meth)acrylamide monomer. Specifically, for example, N-hydroxyethyl acrylamide (trade name "HEAA", manufactured by Xingren Co., Ltd.), N-methoxymethyl propylene decylamine (trade name "NMMA", manufactured by MRC UNITEC Co., Ltd.), N - Butoxymethyl propylene amide (trade name "NBMA", manufactured by MRC UNITEC Co., Ltd.), N-methoxymethyl methacrylamide (trade name "WASUMA 2MA", manufactured by Takino Industrial Co., Ltd.), and the like.

On the other hand, the (meth)acrylic acid oligomer is an urethane (meth)acrylic acid oligomer, a polyester (meth)acrylic acid oligomer, or an epoxy (meth)acrylic acid oligomer. Polymer, etc.

The amine ester (meth)acrylic acid oligomer refers to a compound having an amine ester bond (-NHCOO-) and at least two (meth)acrylonium groups in the molecule. Specifically, an amine esterification reaction product, a polyol, and a polyisocyanate of a hydroxyl group-containing (meth)acrylic monomer having at least one (meth)acrylonium group and at least one hydroxyl group in the molecule; The amine ester compound containing an isocyanate group at the end of the polyisocyanate reaction has a molecular An amine esterification reaction product of at least one (meth)acrylonitrile group and at least one hydroxyl group (meth)acrylic acid monomer.

As the hydroxyl group-containing (meth)acrylic monomer used in the above amine esterification reaction, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or 2-(meth)acrylic acid Hydroxybutyl ester, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerol di(meth) acrylate, trimethylolpropane di(meth) acrylate, neopentyl alcohol N-hydroxyl groups such as (meth) acrylate, dipentaerythritol penta (meth) acrylate, N-hydroxyethyl (meth) acrylamide, and N-hydroxymethyl (meth) acrylamide An alkyl (meth) acrylamide monomer or the like.

As a polyisocyanate for the esterification reaction of a hydroxyl group-containing (meth)acrylic monomer, for example, hexamethylene diisocyanate, octadecyl diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, or Toluene diisocyanate, xylylene diisocyanate, diisocyanate obtained by hydrogenating aromatic isocyanates in the diisocyanates (for example, hydrogenated tolyl diisocyanate, hydrogenated xylylene diisocyanate, etc.), triphenylmethane triisocyanate a di- or tri-isocyanate such as diphenylmethylbenzene triisocyanate or a polyisocyanate obtained by multi-quantifying the above diisocyanate.

Further, as the polyol used for the amine ester compound having an isocyanate group at the terminal by reaction with the polyisocyanate, in addition to the aromatic, aliphatic or alicyclic polyol, a polyester polyol or a poly Ether polyols and the like. As aliphatic and alicyclic polyols, such as 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, and propylene Alcohol, neopentyl glycol, trimethylolethane, trimethylolpropane, di-trimethylolpropane, neopentyl alcohol, dipentaerythritol, dimethylol heptane, dimethylol Propionic acid, dimethylol butyric acid, glycerol, hydrogenated bisphenol A, and the like.

The polyester polyol is obtained by dehydration condensation reaction of the above polyol with a polyvalent carboxylic acid or an anhydride thereof. As the polycarboxylic acid or its anhydride, for example, succinic acid (anhydride), adipic acid (anhydride), maleic acid (anhydride), methylene succinic acid (anhydride), trimellitic acid (anhydride), Pyromellitic acid (anhydride), phthalic acid (anhydride), isophthalic acid, terephthalic acid, hexahydrophthalic acid (anhydride), and the like.

The polyether polyol is a polyalkylene oxide-modified polyol obtained by reacting the above polyol or a dihydroxybenzene with an alkylene oxide in addition to a polyalkylene glycol.

The polyester (meth)acrylic oligomer refers to a compound having an ester bond and at least two (meth)acrylonium groups in the molecule. Specifically, it can be obtained, for example, by a dehydration condensation reaction of (meth)acrylic acid, a polyvalent carboxylic acid or an anhydride thereof with a polyhydric alcohol. a polycarboxylic acid or an anhydride thereof used as a dehydration condensation reaction, for example, succinic acid (anhydride), adipic acid (anhydride), maleic acid (anhydride), methylene succinic acid (anhydride), and benzotriene Formic acid (anhydride), pyromellitic acid (anhydride), hexahydrophthalic acid (anhydride), phthalic acid (anhydride), isophthalic acid, terephthalic acid, and the like. Further, as the polyol used in the dehydration condensation reaction, for example, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, Trimethylolethane, trimethylolpropane, di-trimethylolpropane, pentaerythritol, dipentaerythritol, dimethylol heptane, dimethylolpropionic acid, dimethylol Butyric acid, glycerol, hydrogenated bisphenol A, and the like.

The epoxy group (meth)acrylic acid oligomer can be obtained, for example, by an addition reaction of a polyepoxypropyl ether and (meth)acrylic acid, and has at least two (meth)acrylonium groups in the molecule. Polyepoxypropyl ether used as an addition reaction, such as ethylene glycol diepoxypropyl ether, propylene glycol diepoxypropyl ether, tripropylene glycol diepoxypropyl ether, 1,6-hexanediol Epoxypropyl ether, bisphenol A diglycidyl ether, and the like.

When the total amount of the curable component contained in the radically polymerizable solventless active energy ray-curable adhesive is 100% by weight, the content of the (meth)acrylic compound is preferably 40% by weight or more, and 50% by weight. More than % is more desirable, and 60% by weight or more is more desirable.

(4-4) Radical polymerization initiator

The radical polymerizable and mixed solvent-free active energy ray-curable adhesive usually contain a radical polymerization initiator, and preferably contain a photoradical polymerization initiator. The radical polymerization initiator may be used alone or in combination of two or more.

As the radical polymerization initiator, for example, 1-methylnaphthalene, 2-methylnaphthalene, 1-fluoronaphthalene, 1-chloronaphthalene, 2-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene, 1-iodophthalene, Naphthalene derivatives such as 2-iodophthalene, 1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene and 1,4-dicyanonaphthalene; anthracene, 1,2-benzene And hydrazine, 9,10-dichloropurine, 9,10-dibromofluorene, 9,10-diphenylanthracene, 9-cyanoguanidine, 9,10-dicyanoguanidine and 2,6,9,10 - anthracene derivatives such as tetracyanoguanidine; anthracene derivatives; carbazole, 9-methylcarbazole, 9-phenyloxazole, 9-prop-2-enyl-9H-carbazole, 9-propyl -9H-carbazole, 9-vinylcarbazole, 9H-carbazole-9-ethanol, 9-methyl-3-nitro-9H- Carbazole, 9-methyl-3,6-dinitro-9H-carbazole, 9-octylcarbazole, 9-oxazole methanol, 9-carbazole propionic acid, 9-carbazole propionitrile, 9-B 3-,6-dinitro-9H-carbazole, 9-ethyl-3-nitrocarbazole, 9-ethylcarbazole, 9-isopropylcarbazole, 9-(ethoxycarbonylmethyl Carbazole, 9-(morpholinylmethyl)carbazole, 9-acetamidocarbazole, 9-allylcarbazole, 9-benzyl-9H-carbazole, 9-carbazoleacetic acid, 9-(2-Nitrophenyl)carbazole, 9-(4-methoxyphenyl)oxazole, 9-(1-ethoxy-2-methyl-propyl)-9H-carbazole, 3-nitrocarbazole, 4-hydroxycarbazole, 3,6-dinitro-9H-carbazole, 3,6-diphenyl-9H-carbazole, 2-hydroxycarbazole and 3,6-di a carbazole derivative such as ethyl-9-ethylcarbazole; benzophenone, 4-phenylbenzophenone, 4,4'-bis(dimethoxy)benzophenone, 4, 4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, methyl 2-benzylidene benzoate, 2-methyldi Benzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 3,3-dimethyl-4-methoxybenzophenone, and 2,4,6-trimethyl a benzophenone derivative such as benzophenone; an aromatic carbonyl compound ;[4-(4-methylphenylthio)phenyl]-phenyl ketone; xanthone, thioxanthone, 2-chlorothiazepinone, 4-chlorothiazepinone, 2 -isopropyl thioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthiaxanone, 2,4-diethylthiaxanone and 1-chloro-4-propanol A thioxanthone derivative such as oxythiazinone; and a hydrogen abstraction photoradical generator such as a coumarin derivative.

Further, for example, a cleavage type photoradical generator which generates a radical by cleavage by irradiation with an active energy ray. Specific examples thereof include arylalkyl ketones such as benzoin ether derivatives and acetophenone derivatives, oxime ketones, mercaptophosphine oxides, and thiobenzoic acid S-phenyl esters. Titanocene and their high molecular weight derivatives Things and so on. As a commercially available cleavage type photoradical generator, for example, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-methyl-1-[4-( Methylthio)phenyl-2-morpholinylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-dodecylbenzimidazole 1-hydroxy-1-methylethane, 1-(4-isopropylbenzylidene)-1-hydroxy-1-methylethane, 1-benzylidene-1-hydroxy- 1-methylethane, 1-[4-(2-hydroxyethoxy)-benzylidenyl]-1-hydroxy-1-methylethane, 1-[4-(propyleneoxyoxyethoxy) -Benzylmercapto]-1-hydroxy-1-methylethane, diphenyl ketone, phenyl-1-hydroxy-cyclohexyl ketone, benzyl dimethyl ketal, bis(cyclopentane) Alkenyl)-bis(2,6-difluoro-3-pyrrolyl-phenyl)titanium, (η 6-isopropylbenzene)-(η 5-cyclopentadienyl)iron(II)hexafluorophosphate Salt, trimethyl benzhydryl diphenylphosphine oxide, bis(2,6-dimethoxy-benzylidenyl)-(2,4,4-trimethyl-pentyl)-phosphine oxide , bis(2,4,6-trimethylbenzylidene)-2,4-dipentyloxyphenylphosphine oxide or bis(2,4,6-trimethylbenzylidene)benzene Phosphine oxide, (4-morpholinylbenzylidene)-1-benzyl-1-dimethylamino Alkyl and 4- (methylthio benzoyl-yl) -1-methyl-1-morpholino-ethane.

The amount of the radical polymerization initiator to be added is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, per 100 parts by weight of the radical polymerizable curable component such as a (meth)acrylic compound. When the amount of the radical polymerization initiator exceeds 20 parts by weight, the durability of the obtained polarizing plate may be lowered.

(4-5) photosensitizer

The adhesive may further contain a photosensitizer as needed. By using a photosensitizer The reactivity of the highly hardenable component may improve the mechanical strength of the adhesive layer and the adhesion between the polarizer 10 and the first protective layer 21. Examples of the photosensitizer include a carbonyl compound, an organic sulfur compound, a persulfide compound, a redox compound, an azo and a diazo compound, a halogen compound, a photoreducible dye, and the like.

More specific examples of the photosensitizer are, for example, benzoin methyl ether, benzoin isopropyl ether, and benzoin derivatives such as α,α-dimethoxy-α-phenylacetophenone; benzophenone, 2,4- Dichlorobenzophenone, methyl o-benzylidene benzoate, 4,4'-bis(dimethylamino)benzophenone and 4,4'-bis(diethylamino)di a benzophenone derivative such as benzophenone; a thioxanthone derivative such as 2-chlorothiazinone or 2-isopropylthioxanthone; 2-chloroindanone and 2-methylfluorenone And other anthrone derivatives; acridinone derivatives such as N-methylacridone and N-butylacridone; others, such as α,α-diethoxyacetophenone, diphenylethylene Benzil, fluorenone, xanthone, uranium-quinone compounds, halogen compounds, and the like. The photosensitizer may be used alone or in combination of two or more. The photosensitizer is preferably contained in an amount of from 0.1 to 20 parts by weight per 100 parts by weight of the adhesive.

(4-6) cationic polymerization accelerator

The cationically polymerizable solvent-free active energy ray-curable adhesive may further contain a cationic polymerization-promoting compound such as an oxetane or a polyhydric alcohol.

Oxycyclobutanes are compounds having a 4-membered cyclic ether in the molecule. Specific examples of oxycyclobutanes include 3-ethyl-3-hydroxymethyloxetane Alkane, 1,4-bis[(3-ethyl-3-oxocyclobutyl)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxycyclobutane, di[ (3-ethyl-3-oxocyclobutane)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxycyclobutane, 3-ethyl-3{[ (3-Ethyloxycyclobutane-3-yl)methoxy]methyl}oxycyclobutane, phenol novolac resin oxycyclobutane. The oxycyclobutanes usually contain a ratio of 5 to 50% by weight, preferably 10 to 40% by weight, in the solventless active energy ray-curable adhesive. The oxocyclobutanes may be used alone or in combination of two or more.

The polyol is preferably an acidic group other than a phenolic hydroxyl group, for example, a polyol compound having no functional group other than a hydroxyl group, a polyester polyol compound, a polycaprolactone polyol compound, and a phenolic hydroxyl group. A polyol compound, a polycarbonate polyol, or the like. The molecular weight of the polyol is usually 48 or more, more preferably 62 or more, still more preferably 100 or more, and still more preferably 1,000 or less. The polyol is usually contained in the present adhesive in an amount of 50% by weight or less, preferably 30% by weight or less. The polyols may be used alone or in combination of two or more.

(4-7) Thickness of other additives and first adhesive layer

The cationically polymerizable and mixed solvent-free active energy ray-curable adhesive may contain a (meth)acrylic compound or the like together with a cationically polymerizable curable component such as an epoxy compound. By using a (meth)acrylic compound in combination, it is expected to improve the adhesion between the polarizer 10 and the first protective layer 21, the hardness of the adhesive layer, and the mechanical strength, and further, the viscosity and hardening of the adhesive. Adjustments such as speed can be performed more easily. As such The (meth)acrylic compound is, for example, the same as described above.

When a (meth)acrylic compound is blended in a cationically polymerizable and mixed solventless active energy ray-curable adhesive, the amount is a cationically polymerizable and mixed solvent-free active energy ray-curable adhesive. When the total amount of the curable component contained in the content is 100% by weight, it is preferably 30% by weight or less, more preferably 20% by weight or less. When the amount of the (meth)acrylic compound is too large, the adhesion between the polarizer 10 and the first protective layer 21 tends to decrease.

The radically polymerizable solvent-free active energy ray-curable adhesive may contain an epoxy compound. When the radically polymerizable solventless active energy ray-curable adhesive contains an epoxy compound, the amount is a curable component contained in the radically polymerizable solventless active energy ray-curable adhesive. When the total amount is 100% by weight, it is preferably from 0 to 20% by weight, more preferably from 0 to 5% by weight. The durability and water resistance of the first adhesive layer 15 tend to be good as long as the content of the epoxy compound is 5% by weight or less.

Further, the radically polymerizable solvent-free active energy ray-curable adhesive may contain a cationic polymerization initiator together with the radically polymerizable initiator. By using a cationic polymerization initiator in combination, it is expected to improve the adhesion between the polarizer 10 and the first protective layer 21, the hardness of the adhesive layer, and the mechanical strength, and further, the viscosity and the curing speed of the adhesive. Adjustments can be made easier. As such a cationic polymerization initiator, for example, the same as described above.

Free radical polymerizable solvent-free active energy line hard When the cationic polymerization initiator is blended in the binder, the amount is preferably 100% by weight of the total amount of the curable component contained in the radically polymerizable solventless active energy ray-curable adhesive. It is from 0.01 to 10% by weight, more desirably from 0.1 to 3% by weight.

Further, the present adhesive may contain an ion scavenger, an antioxidant, a chain transfer agent, an adhesion-imparting agent, a thermoplastic resin, a filler, a flow regulator, a plasticizer, an antifoaming agent, an antistatic agent, and a tone as needed. Additives such as flat agents. Examples of the ion scavenger include inorganic compounds such as powdered lanthanoid, lanthanide, magnesium, aluminum, calcium, titanium, and the like, and antioxidants such as hindered phenol antioxidants.

The thickness of the first adhesive layer 15 is, for example, about 0.01 to 10 μm, preferably about 0.01 to 5 μm, more preferably 4 μm or less (for example, 3 μm or less).

(4-8) bonding of the polarizer to the first protective layer

The adhesive is applied to the bonding surface of the polarizing plate 10 or the bonding surface of the first protective layer 21, and the two films are laminated via the applied adhesive layer, and are pressed from the top and bottom, for example, by using a bonding roller or the like. The first protective layer 21 is bonded to the polarizer 10 by curing the adhesive layer by irradiation of the active energy ray.

As a coating method of this adhesive agent, for example, a doctor blade, a wire bar, a slit coater, a notch wheel coater, a gravure coater, etc. are mentioned. Among them, a gravure coater is preferably used as the adhesive application device in consideration of coating of a film, degree of freedom of a route, correspondence with respect to width, and the like.

This adhesive is usually adjusted to 15 to 40 ° C after preparation. The specified temperature within the range is ±5 ° C (for example, 30 ° C ± 5 ° C when the specified temperature is 30 ° C), preferably ± 3 ° C, more preferably ± 1 ° C. By adjusting the temperature of the adhesive, the viscosity can be adjusted to control the coating thickness of the adhesive.

The active energy ray may be visible light, ultraviolet light, X-ray, electron beam or the like, and it is preferable to use ultraviolet rays from the viewpoints of easiness of preparation, ease of preparation of the adhesive, stability, and hardenability thereof. The light source of the active energy ray is not particularly limited, and for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, a black light, a microwave-excited mercury lamp, a metal halide lamp, etc., having a light-emitting distribution having a wavelength of 400 nm or less can be used. More ideal.

The light irradiation intensity of the present adhesive is determined depending on the respective compositions of the present adhesive, and is not particularly limited, and is preferably 10 to 5000 mW/cm ² . When the light irradiation intensity of the resin composition is less than 10 mW/cm ² , the reaction time becomes too long, and when it exceeds 5000 mW/cm ² , the adhesive may be generated due to heat radiated from the lamp and heat generation during polymerization of the composition. Yellowing of constituent materials and the like, deterioration of the polarizer 10, thermal shrinkage of the film, and surface defects (concavities and convexities on the surface of the film) caused by the film. When the thickness of the film on the irradiation side is thinner than 40 μm, the influence of the heat is more remarkable when the light irradiation intensity is stronger, and the glass transition temperature Tg is also significantly higher than 120 °C. In addition, the intensity of the light irradiation is preferably the intensity of the wavelength region effective for activation of the photopolymerization initiator, and more preferably the wavelength in the wavelength region of 400 nm or less, and more preferably the wavelength region of the UVB region (260 to 320 nm). strength. Moreover, the effect of this heat, the closer to the light source, the greater the impact.

The amount of irradiation light of the ultraviolet active energy ray is preferably 10 to 1000 mJ/m ^{2 in terms} of the cumulative amount of light in the UVB region (260 to 320 nm). When the amount of accumulated light is within this range, the polarizer 10 and the first protective layer 21 can be bonded to each other more closely by using the adhesive. When the cumulative amount of light is 10 mJ/m ² , the generation of the active species from the initiator is insufficient, and the hardening of the adhesive becomes insufficient. On the other hand, when the accumulated light amount exceeds 1000 mJ/m ² , the irradiation time becomes very long, which is unfavorable for production, or requires strong irradiation energy, and as described above, a problem caused by heat radiated from the lamp is generated.

When the polarizing plate includes the second protective layer 22 laminated via the second adhesive layer 25, the second protective layer 22 may be formed after the first protective layer 21 is laminated and the first adhesive layer 15 is cured. When the laminate and the second adhesive layer 25 are cured, the first protective layer 21 and the second protective layer 22 are bonded in this order, and when the second adhesive layer 25 is also formed of an active energy ray-curable adhesive, After the first and second protective layers 21 and 22 are simultaneously laminated, the first and second adhesive layers 15 and 25 are simultaneously cured.

Before the bonding of the first protective layer 21, in order to further improve the adhesion to the polarizer 10, the bonding surface of the first protective layer 21 with the polarizer 10 and the first protective layer 21 of the polarizer 10 may be used. At least one of the bonding surfaces is subjected to corona discharge treatment, plasma irradiation treatment, electron beam irradiation treatment, and other surface activation treatment. Further, in order to further improve the adhesion to the polarizer 10, an easy-adhesion layer (primer layer) may be provided on the bonding surface of the first protective layer 21 and the polarizing film 10.

(5) 2nd protective layer

The second protective layer 22 is a layer that is arbitrarily attached to the surface of the polarizer 10 opposite to the first protective layer 21 side. The second protective layer 22 may be, for example, a translucent resin, and is preferably an optically transparent thermoplastic resin film.

Specific examples of the thermoplastic resin constituting the second protective layer 22 include a chain-like polyolefin resin (such as a polypropylene resin or a polyethylene resin) and a cyclic polymerization in addition to the methacrylic resin [A]. a polyolefin-based resin such as an olefin resin (northene-based resin); a polyester-based resin such as polyethylene terephthalate; or a (meth)acrylic resin other than the methacrylic resin [A]; Cellulose resin such as cellulose triacetate or cellulose diacetate; polycarbonate resin; polyvinyl alcohol resin; polyvinyl acetate resin, polyarylate resin; polystyrene resin , a polyether oxime resin, a polyfluorene-based resin; a polyamidide-based resin; a polyimide-based resin; and such a mixture or copolymer.

The cyclic olefin resin is a resin having a monomer unit composed of a cyclic olefin such as a norbornene or a polycyclic norbornene-based monomer, for example, a hydrogenated product of a ring-opening copolymer of the above cyclic olefin, and a use 2 a hydride of a ring-opening copolymer of a cyclic olefin or more, a cyclic olefin, and a chain olefin (such as ethylene or propylene) and/or an aromatic compound having a vinyl group (styrene or α-methylstyrene, An addition polymer such as a nucleoalkyl group substituted with styrene or the like.

The (meth)acrylic resin other than the methacrylic resin [A] may be a main component (including 50% by weight or more) of a methacrylic resin other than the methacrylic resin [A], and is preferably a methyl group. A resin composed of a methacrylic resin other than the acrylic resin [A].

The methacrylic resin other than the methacrylic resin [A] is a resin other than the methacrylic resin [A] mainly composed of methacrylate (containing 50% by weight or more). The methacrylic resin may be a homopolymer of one type of methacrylate, or may be a copolymer of methacrylate and another methacrylate, acrylate or other polymerizable monomer. As methacrylate, including methyl methacrylate, ethyl methacrylate, n- or isopropyl methacrylate, n-, iso- or 3-butyl methacrylate, 2-ethyl methacrylate An alkyl group such as a hexyl hexyl ester, a cyclohexyl methacrylate or a 2-hydroxyethyl methacrylate having an alkyl group having 1 to 8 carbon atoms. The alkyl group preferably has a carbon number of from 1 to 4. The methacrylate may be used alone or in combination of two or more.

As the acrylate copolymerizable with the methacrylate, an alkyl acrylate can be used, and specific examples thereof include methyl acrylate, ethyl acrylate, n- or isopropyl acrylate, n-, isopropyl- or 3- An alkyl acrylate having a carbon number of 1 to 8 of an alkyl group such as butyl ester, 2-ethylhexyl acrylate, cyclohexyl acrylate or 2-hydroxyethyl acrylate. The alkyl group preferably has a carbon number of from 1 to 4. The acrylate may be used alone or in combination of two or more.

Specific examples of the other polymerizable monomer copolymerizable with the methacrylate include, for example, a monofunctional monomer having one polymerizable carbon-carbon double bond in the molecule and at least two polymerizable carbon-carbons in the molecule. A double bond polyfunctional monomer. Specific examples of the monofunctional monomer include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, halogenated styrene, and hydroxystyrene; and vinyl cyanide such as acrylonitrile or methacrylonitrile. ;acrylic acid, An unsaturated acid such as methacrylic acid, maleic anhydride or methylene succinic anhydride; N-methyl maleimide, N-cyclohexylmaleimide, N-phenyl malayan Maleic imine such as amine; allyl alcohol such as methyl allyl alcohol or allyl alcohol; vinyl acetate, vinyl chloride, ethylene, propylene, 4-methyl-1-pentene, 2-hydroxymethyl Other monomers such as 1-butene, methyl vinyl ketone, N-vinyl pyrrolidone, N-vinyl carbazole.

Specific examples of the polyfunctional monomer include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate; Enyl ester of an unsaturated carboxylic acid such as propyl ester, allyl methacrylate or allyl cinnamate; diallyl phthalate, diallyl maleate or urocyanurate A polyene ester of a polybasic acid such as triallyl isocyanurate or an aromatic polyene compound such as divinylbenzene. The other polymerizable monomers may be used alone or in combination of two or more.

In order to improve the film forming property of the (meth)acrylic resin, the impact resistance of the second protective layer 22, and the surface smoothness of the second protective layer 22, the second protective layer 22 made of a (meth)acrylic resin may be used. Contains the above rubber particles. Regarding the rubber particles, the above description regarding the first protective layer 21 is cited.

Among the above, the second protective layer 22 is preferably a film containing a methacrylic resin [A] or a film containing a (meth)acrylic resin other than the methacrylic resin [A]. When the film of the resin of the same system is used for the protective layer on both surfaces of the polarizer 10, the operation of the dimensional change is symmetrical, and the polarizing plate can be prevented from being bent. This is the IPS mode. Particularly effective.

The second protective layer 22 of the film may be a stretched film extending in at least one direction. The film formation method, the stretched state of the second protective layer 22 of the film, the thickness of the film, the additive, and the like are described above with respect to the first protective layer 21.

Further, the second protective layer 22 may be a cured layer of an active energy ray-curable resin composition directly laminated on the surface of the polarizer 10. Such a cured layer can be directly coated with an active energy ray-curable resin composition by a surface of the polarizer 10, and then irradiated with an active energy ray to cure the coating layer, or a peelable substrate (release type) After coating the active energy ray-curable resin composition on the film or the like, the layer is laminated on the surface of the polarizer 10 on the side of the coating layer, and the active energy ray is applied to cure the coating layer, and then the substrate is peeled off. Formed by the method. The thickness of the second protective layer 22 composed of the cured layer is, for example, about 1 to 30 μm.

As the active energy ray-curable resin composition, the same composition as the above-described solvent-free active energy ray-curable adhesive can be used, and the above description is incorporated in the detailed description.

(6) 2nd adhesive layer

The second adhesive layer 25 is a layer for bonding the polarizer 10 and the second protective layer 22 of the film. The adhesive agent forming the second adhesive layer 25 is derived from the solvent-free active energy ray-curable adhesive, other active energy ray-curable adhesive, and water-based adhesive depending on the type of the thermoplastic resin constituting the second protective layer 22 and the like. (adhesive, water composed of aqueous solution of polyvinyl alcohol resin) A two-component amine ester emulsion adhesive, etc.) is selected. When the second protective layer 22 is a film containing the methacrylic resin [A], the solvent-free active energy ray-curable adhesive similar to the first adhesive layer 15 is used in order to obtain good adhesion.

The thickness of the second protective layer 22 and the bonding method of the polarizer 10 and the second protective layer 22 of the film are described above with respect to the first adhesive layer 15.

Before the bonding of the second protective layer 22, in order to further improve the adhesion to the polarizer 10, the bonding surface of the second protective layer 22 to the polarizing film 10 and the bonding of the polarizing film 10 to the second protective layer 22 are applied. At least one of the mating surfaces is subjected to corona discharge treatment, plasma irradiation treatment, electron beam irradiation treatment, saponification treatment, and other surface activation treatment. Further, in order to further improve the adhesion to the polarizer 10, an easy-adhesion layer (undercoat layer) may be provided on the bonding surface of the second protective layer 22 and the polarizing film 10.

(7) Adhesive layer

The polarizing plate may include an adhesive layer 30 for bonding the polarizing plate to another member such as a liquid crystal cell. The adhesive layer 30 can be disposed on the outer surfaces of the first or second protective layers 21 and 22 when the first and second protective layers 21 and 22 are provided, for example, as shown in the polarizing plate 1 of Fig. 1 . However, when the second protective layer 22 is formed of a methacrylic resin [A], particularly when the polarizing plate is applied to an IPS mode liquid crystal panel, optical characteristics such as low birefringence (optical isotropic property) are excellent. The first protective layer 21 is preferably used as a protective layer disposed on the liquid crystal cell side of the polarizer 10, so that the outer surface of the first protective layer 21 is formed. On the surface, it is preferable to arrange the adhesive layer 30. When the second protective layer 22 is a cured layer of the active energy ray-curable resin composition, the adhesive layer 30 may be disposed on the outer surface of the first protective layer 21 or on the outer surface of the second protective layer 22. .

On the other hand, when the second protective layer 22 is not provided in the polarizing plate 2 shown in FIG. 2, an adhesive may be disposed on the outer surface (surface opposite to the first protective layer 21) of the polarizing plate 10. Layer 30.

Adhesive used in the adhesive layer 30, for example, an acrylic adhesive, an amine ester adhesive, an anthrone adhesive, a polyester adhesive, a polyamide adhesive, a polyether adhesive, or a fluorine adhesive. Among them, an acrylic adhesive is preferred from the viewpoints of transparency, adhesion, reliability, and reworkability.

The adhesive layer 30 can be formed by applying the above-mentioned adhesive in the form of an organic solvent solution, applying it to the surface on which the adhesive layer is formed, and drying it. The sheet-like adhesive on the release-treated plastic film (also referred to as a release film) is transferred to the surface on which the adhesive layer is formed. In either method, it is preferred to laminate the outer surface of the adhesive layer 30 after the surface on which the adhesive layer is formed to adhere the release film for the protective surface. The thickness of the adhesive layer 30 is usually 2 to 40 μm.

The release film may be a film made of a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, or a polyester resin such as polyethylene terephthalate. Among them, a stretch film of polyethylene terephthalate is preferred.

(8) Coating layer

The polarizing plate may be provided on the outer surface of the first or second protective layers 21 and 22 (the outer surface of the protective layer away from the liquid crystal cell side) when the adhesive layer 30 is provided in order to impart desired optical characteristics or other characteristics. The outermost surface of the polarizing plate on the opposite side of the side of the adhesive layer 30 is provided with a coating layer. Specific examples of the coating layer include a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, and an antifouling layer. The method of forming the coating layer is not particularly limited, and a conventional method can be used.

<LCD panel>

The liquid crystal panel of the present invention includes a liquid crystal cell and the above-described polarizing plate of the present invention disposed on at least one surface thereof. An example of the layer configuration of the liquid crystal panel of the present invention is shown in Fig. 3. In the liquid crystal panel 3 shown in Fig. 3, the polarizing plate 1 shown in Fig. 1 is used for the polarizing plates disposed on both surfaces of the liquid crystal cell 40, or the polarizing plate of the present invention can be used only in any of the polarizing plates. It is desirable that at least the polarizing plate on the viewing side uses the polarizing plate of the present invention. When the second protective layer 22 is a film containing the methacrylic resin [A], the second protective layer 22 can be used as a protective layer on the liquid crystal cell 40 side. When the polarizing plate 2 shown in FIG. 2 is used, the polarizing plate 2 is bonded to the liquid crystal cell 40 with the first protective layer 21 facing outward.

The driving mode of the liquid crystal cell 40 may be any conventionally known mode such as an IPS mode, a VA (Vertical Alignment) mode, or a TN (Twisted Nematic) mode, but as described above, it is preferable to be an IPS mode. IPS mode, in A nematic liquid crystal uniformly aligned in the absence of an electric field is image-displayed by driving of a transverse electric field, and has an advantage of a wide viewing angle as compared with other driving modes. The color change (also referred to as the color shift in the oblique direction) of the image at the angle of the observation screen is large, and this disadvantage can be improved by using a polarizing plate including the first protective layer having excellent optical isotropic properties.

In the liquid crystal panel of the present invention and the liquid crystal display device using the same, since the polarizer of the polarizing plate contained in the polarizing plate has excellent adhesion to the protective layer, it is excellent in durability.

example

Hereinafter, the present invention will be more specifically described by showing examples and comparative examples, but the present invention is not limited to the examples.

<Examples 1 to 7, Comparative Examples 1 to 13> (1) Production of polarizer

The polyvinyl alcohol film having a thickness of 75 μm having an average polymerization degree of about 2400 and a saponification degree of 99.9 mol% or more was immersed in pure water at 30° C., and then immersed in a weight ratio of iodine/potassium iodide/water at 0.02/2/100 at 30° C. Aqueous solution. Then, it was immersed in an aqueous solution of potassium iodide/boric acid/water in a weight ratio of 12/5/100 at 56.5 °C. Subsequently, the mixture was washed with pure water at 8 ° C, and then dried at 65 ° C to obtain a polarizing plate of a polyvinyl alcohol film in which iodine was adsorbed and aligned. The stretching was carried out mainly in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times, and the obtained polarizing plate had a thickness of 27 μm.

(2) Production of protective layer (protective film) ‧ Preparation

[a] Methacrylic resin film a: A biaxially stretched film having a thickness of 40 μm composed of the above methacrylic resin [A] (MD stretching ratio: 1.8 times, TD stretching ratio: 2.5 times). In the film, the methacrylic resin [A] is methyl methacrylate / N-phenyl maleimide / N-cyclohexyl maleimide = about 84% / about 8% / about 8% (weight ratio) copolymer. The weight average molecular weight Mw of the methacrylic resin [A] was 167,500 in terms of GPC, and the Mw/Mn was 2.5.

[b] Methacrylic resin film b: It was produced in the following procedure. A copolymer of methyl methacrylate/methyl acrylate = 96% / 4% by weight was prepared as a methacrylic resin. Further, as the rubber particles, the innermost layer is composed of a hard polymer obtained by polymerizing a small amount of allyl methacrylate in methyl methacrylate, and the intermediate layer is mainly composed of butyl acrylate, and styrene is used. A soft elastomer composed of a small amount of allyl methacrylate polymerized, and the outermost layer is a three-layered elastomer particle composed of a hard polymer polymerized with a small amount of ethyl acrylate in methyl methacrylate to the intermediate layer. The average particle diameter of the elastomer is 240 nm, and in the rubber particles, the total weight of the innermost layer and the intermediate layer is 70% of the total particles.

70% by weight of the above methacrylic resin and 30% by weight of the rubber particles were mixed in a super mixer, and melt-kneaded into pellets in a two-axis extruder. The pellet was placed in a 65 mm φ one-axis extruder, extruded through a T-die at a set temperature of 275 ° C, and cooled by sandwiching the film with two mirror rollers, to obtain a methacrylic acid having a thickness of 50 μm. Resin film b.

[c] Methacrylic resin film c: a biaxially stretched film having a thickness of 40 μm composed of a copolymer of methyl methacrylate/methyl acrylate = 96% / 4% by weight (MD stretching ratio: 2.0 Double, TD stretching ratio: 2.0 times).

[d] TAC film d: a triacetyl cellulose film "KC4UY" (thickness: 40 μm) manufactured by Konica Minolta Optical Co., Ltd.

[e] COP film e: "ZEONOR" (thickness: 23 μm) of a cyclic polyolefin resin film of Japan ZEON Co., Ltd.

(3) Preparation of adhesive

[f-1] Ultraviolet curable adhesive f-1: A solventless ultraviolet curable adhesive obtained by mixing the following formulation components. % indicates the content (% by weight) when the total amount of the adhesive is 100% by weight.

‧3', 4'-Epoxycyclohexenylcarboxylic acid 3,4-epoxycyclohexenylmethyl ester ("CELLOXIDE 2021", manufactured by DIACEL Chemical Industries, Inc.): 80%

‧ 1,4-butanediol diepoxypropyl ether: 19%

‧Photocationic polymerization initiator containing triarylsulfonium hexafluorophosphate as a main component: a small amount

[f-2] Ultraviolet curable adhesive f-2: A solvent-containing ultraviolet curable adhesive containing 25% by weight of toluene mixed with 75 parts by weight of the ultraviolet curable adhesive f-1.

[f-3] Ultraviolet curable adhesive f-3: A solvent-containing ultraviolet curable adhesive containing 25% by weight of methyl ethyl ketone mixed with 75 parts by weight of the ultraviolet curable adhesive f-1.

[g] Ultraviolet curable adhesive g: A solventless ultraviolet curable adhesive obtained by mixing the following formulation components. % indicates the content (% by weight) when the total amount of the adhesive is 100% by weight.

‧3', 4'-Epoxycyclohexenylcarboxylic acid 3,4-epoxycyclohexenylmethyl ester ("CELLOXIDE 2021", manufactured by DIACEL Chemical Industries, Inc.): 52%

‧3-ethyl-3-hydroxymethyloxetane ("ARON OXETANE OXT-101" by East Asian Synthetic Co., Ltd.): 20%

‧3-ethyl-3{[(3-ethyloxocyclobutane-3-yl)methoxy]methyl}oxycyclobutane ("ARON OXETANE OXT-221" by East Asia Synthetic Co., Ltd.) :5%

‧1,6-hexanediol diacrylate ("LIGHT ACRYLATE 1,6HX-A" by Kyoeisha Chemical Co., Ltd.): 22%

‧1-Hydroxycyclohexyl phenyl ketone (light free radical initiator "IRGACURE 184" manufactured by BASF): small amount

‧Photocationic polymerization initiator containing triarylsulfonium hexafluorophosphate as a main component: a small amount

[h] Water-based adhesive h: It was produced in the following order. Polyvinyl alcohol powder [trade name "KL-318" manufactured by Kuraray Co., Ltd., average polymerization degree 1800] was dissolved in hot water at 95 ° C to prepare a polyvinyl alcohol aqueous solution having a concentration of 3 wt%, and mixed in the obtained aqueous solution. A cross-linking agent [product name "SUMIREZ RESIN 650" manufactured by Tajika Chemical Industry Co., Ltd.] in a ratio of 1 part by weight based on 2 parts by weight of the polyvinyl alcohol powder was obtained as a water-based adhesive.

[i-1] ultraviolet curable adhesive i-1: a solventless ultraviolet curable adhesive obtained by mixing the following formulation components. % indicates the content (% by weight) when the total amount of the adhesive is 100% by weight.

‧4-propenylmorpholine: 46%

‧ Hydroxyethyl acrylamide: 46%

‧Tripropylene glycol diacrylate: 7%

‧2-Methyl-1-[4-(methylthiophenyl)-2-(N-morpholinyl)propan-1-one (photoinitiator “IRGACURE 907” manufactured by BASF): small amount

[i-2] Ultraviolet curable adhesive i-2: A solvent-based ultraviolet curable adhesive containing 25% by weight of methyl ethyl ketone mixed with the ultraviolet curable adhesive i-175% by weight.

(4) Production of polarizing plate

The adhesive layer shown in Table 1 was applied to the surface of the first protective layer and the second protective layer polarizer shown in Table 1, and the first protective layer was laminated so that the adhesive layer became the polarizer side. On the one side of the polarizer, the second protective layer is laminated on the other side, and the first protective layer/adhesive layer/polarizer/adhesive layer/second protective layer is obtained by bonding the roller. The layered body of the layer. Then, ultraviolet rays were irradiated from the side of the first protective layer, and the adhesive layers on both sides were cured to obtain a polarizing plate. In the ultraviolet irradiation, a metal halide lamp was used, and the distance between the lamp and the laminate was kept at 200 mm, the illuminance in the wavelength region of 260 to 320 nm was 200 mW/cm ² , and the cumulative light amount was 200 mJ/cm ² . In Comparative Example 9 using a water-based adhesive, the laminate was placed in a drying furnace instead of ultraviolet rays, and the adhesive layer was dried by heat treatment at 80 ° C for 300 seconds to obtain a polarizing plate.

Further, before the application of the adhesive, the surface of the first protective layer and the second protective layer is surface-activated (the saponification is performed at the time of the TAC film). For the protective layer other than it, corona discharge treatment).

<Evaluation of adhesion>

The evaluation test shown below was performed to evaluate the adhesion (adhesion force) between the polarizer and the protective layer. The results are combined and shown in Table 1.

(1) Evaluation of the adhesion after the bonding

Three minutes after the completion of the irradiation of the ultraviolet ray, the protective layer to be evaluated and the polarizer shown in Table 1 were peeled off by hand, and the state at the time of peeling by hand and the force applied by hand were evaluated based on the following evaluation criteria. Synergy. In addition, in Comparative Example 9 using a water-based adhesive, the above evaluation test was performed 3 minutes after the completion of the heat treatment (drying treatment).

A: It must be carefully and carefully removed to be peeled off, or the degree of adhesion of the protective layer is not peeled off when the force is applied.

B: There is no adhesion to the extent of the breakage of the protective layer, and it is not a weak adhesion to the extent of peeling with a little force.

C: The adhesion to the extent that it can be peeled off with a little force is extremely weak

(2) 180° peel test (evaluation of final adhesion)

After 24 hours from the end of the irradiation of the ultraviolet rays (in the case of the completion of the heat treatment in Comparative Example 9), the 180° peeling test was performed in the following procedure. First, from the polarizing plate, a rectangular evaluation sample in which the absorption axis direction of the polarizer was 150 mm long and 25 mm in width was obtained. Then, the protective layer side of the evaluation object shown in Table 1 of the sample for evaluation was attached to the glass using double-sided tape. Glass substrate. Then, at one end in the longitudinal direction of the evaluation sample attached to the glass substrate, a starting portion (peeling portion) was formed between the protective layer and the polarizing plate to be evaluated shown in Table 1, and the initial portion of the polarizing plate was formed. The laminate of the protective layer of the non-evaluation target was clamped with a jig of a universal testing machine ("Autograbh AGS-50NX" manufactured by Shimadzu Corporation), and the universal testing machine was used in an environment of a temperature of 23 ° C and a relative humidity of 50%. The laminated body which was accommodated was pulled up at a peeling speed of 300 mm/min in the direction of one end in the longitudinal direction opposite to the sandwiching side, and a 180° peeling test was performed, and the stress (N/25 mm) at the time of peeling was measured.

(3) Evaluation of peeling when cutting polarizing plates

The polarizing plate after 24 hours from the end of the irradiation of the ultraviolet rays (in the case of the completion of the heat treatment in Comparative Example 9) was cut with a Thomson blade, and the protective layer and the polarizer of the evaluation object shown in Table 1 were visually confirmed on the cut surface. Whether it is seen between the peeling.

1‧‧‧Polar plate

10‧‧‧ polarizer

15‧‧‧1st adhesive layer

21‧‧‧1st protective layer

22‧‧‧2nd protective layer

25‧‧‧2nd adhesive layer

30‧‧‧Adhesive layer

Claims (13)

A polarizing plate comprising: a polyvinyl alcohol-based polarizer; and a first protective layer laminated on a surface of the one side via a first adhesive; wherein the first adhesive layer is solvent-free active energy ray hardenability a cured layer of the adhesive; the first protective layer is a layer containing a methacrylic resin having a following general formula (I): 50 to 95% by weight: [In the formula (I), R ¹ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkylalkyl group having 4 to 12 carbon atoms, or a cycloalkane having 5 to 12 carbon atoms; a arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms or an alkoxy group having a halogen atom, a hydroxyl group, a nitro group, a carbon number of 1 to 12, and a carbon number of 1 to 12 The first constituent unit represented by the aryl group having 6 to 14 carbon atoms of at least one substituent group in the group, and 0.1 to 20% by weight of the following general formula (II): [In the formula (II), R ² represents an arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms or an alkoxy group having a halogen atom, a hydroxyl group, a nitro group and a carbon number of 1 to 12 a aryl group having 6 to 14 carbon atoms of a group of at least one substituent group of a group having 1 to 12 carbon atoms and an arylalkyl group having 7 to 14 carbon atoms; and R ³ and R ⁴ each independently represent hydrogen a second structural unit represented by an atom, an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms, and 0.1 to 49.9% by weight of the following general formula (III): [In the formula (III), R ⁵ represents a cycloalkyl group having 3 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms, a cycloalkylalkyl group having 4 to 12 carbon atoms or having a halogen atom, a hydroxyl group, or the like. a carbon having 1 to 12 carbon atoms of at least one substituent of a nitro group and an alkoxy group having 1 to 12 carbon atoms; and R ⁶ and R ⁷ each independently represent a hydrogen atom and an alkyl group having 1 to 12 carbon atoms; The third constituent unit represented by a group or an aryl group having 6 to 14 carbon atoms. The polarizing plate according to claim 1, wherein the active energy ray-curable adhesive comprises an active energy ray-curable epoxy compound. The polarizing plate according to claim 2, wherein the active energy ray-curable epoxy compound comprises a compound having one or more epoxy groups bonded to an alicyclic ring in the molecule. The polarizing plate of claim 1, wherein the active energy ray-curable adhesive further comprises a cationic polymerization initiator. The polarizing plate according to claim 1, wherein the active energy ray-curable adhesive comprises a (meth)acrylic compound. The polarizing plate of claim 1, wherein the active energy ray-curable adhesive comprises a (meth) acrylamide monomer having at least one (meth) acrylonitrile group and a guanamine bond in the molecule. . The polarizing plate according to claim 1, wherein the first protective layer is a film extending in at least one direction, and the stretching ratio is 1.2 times or more. The polarizing plate according to Item 1, wherein the first protective layer is laminated on the surface of one side of the polyvinyl alcohol-based polarizer via the first adhesive; and the polyethylene is A second protective layer containing a thermoplastic resin different from the methacrylic resin interposed between the second adhesive layer on the other surface of the alcohol-based polarizer. The polarizing plate of claim 1, further comprising an adhesive layer. The polarizing plate according to claim 9, wherein the adhesive layer is disposed on an outer surface of the first protective layer. The polarizing plate according to claim 9, wherein the adhesive layer is disposed on an outer surface of the second protective layer. A liquid crystal panel comprising: a liquid crystal cell; and a polarizing plate according to any one of claims 1 to 11, wherein the liquid crystal cell and the surface disposed on at least one side thereof. The liquid crystal panel of claim 12, wherein the liquid crystal cell is a liquid crystal cell of a transverse electric field effect mode.