JP2001201631A - Protective film for polarizing plate and polarizing plate utilizing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective film for a polarizing plate having an excellent antistatic property and an excellent adhesive property to a PVA(polyvinyl alcohol) polarizer film and the polarizing plate without abnormal liquid crystal display utilizing it. SOLUTION: The protective film for the polarizing plate, which comprises a conductive layer containing a conductive material on a resin film, is characterized by having <=1011 Ω/cm surface specific resistance of the conductive layer (at 23 deg.C, 55% RH) and by providing the conductive layer with an easy-to-adhere function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a protective film for a polarizing plate and a polarizing plate using the same.

[0002]

2. Description of the Related Art A polarizing plate in which a cellulose triacetate film is bonded as a protective film to a polarizer of a polyvinyl alcohol film (PVA film) uniaxially stretched by dyeing is widely used as a liquid crystal display device, such as a personal computer, a liquid crystal television,
It is widely used for display units such as calculators, electric appliances, clocks, and high-definition displays such as car navigators.

[0003] In the case of a cellulose triacetate film most widely used as a protective film, the surface is saponified in advance with an alkali solution and then laminated with a polyvinyl alcohol-based adhesive or the like to form a polarizing film. However, the alkali treatment uses a high-concentration alkaline solution, which is not preferable in terms of work safety and environmental protection. Further, the alkali treatment may cause a bleed out of a plasticizer or a decrease in quality such as an increase in haze. . In addition, if a process for imparting functionality such as an antistatic process, a hard coat process, and an antireflection process is performed before the alkali treatment, the effect is reduced by the alkali treatment. There are problems such as being limited after processing.

On the other hand, JP-A-6-94915 and 6-1.
Nos. 18232 and 7-333436 describe the preparation of a protective film for a polarizing plate which does not require alkali treatment. That is, this is a method in which a layer containing a certain kind of hydrophilic polymer compound is provided on the surface to be bonded to the polarizer. However, this is because the surface resistivity is high, and in the polarizing plate manufacturing process, the protective film for the polarizing plate is likely to be charged with static electricity, dust and film cuttings easily adhere to the surface of the protective film, and when bonded to a polarizer. In some cases, visibility is impaired as a foreign matter defect.

[0005] Further, when bonding with a polarizer using a polyvinyl alcohol-based adhesive, fine bubbles may be generated at the interface between the two, and a fine foreign substance failure may appear on the bonding surface. Do you get it. It has been found that these defects greatly impair visibility and significantly reduce the yield in the polarizing plate manufacturing process. It is a major problem to improve these, and there has been a demand for a solution to the problem.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polarizing plate protective film having excellent antistatic properties and good adhesion to a PVA polarizer film, and a liquid crystal by using the same. An object of the present invention is to provide a polarizing plate free from abnormal display.

[0007]

The above objects of the present invention have been attained by the following items 1 to 15.

[0008] 1. On a protective film for a polarizing plate having a conductive layer containing a conductive material on a resin film,
The surface resistivity of the conductive layer is 10 ¹¹ Ω / cm (23 ° C., 5
5% RH) or less, and the conductive layer has an easy adhesion function.

[0009] 2. The conductive layer is a hydrophilic polymer compound (a)
Or a layer (2) containing at least one of gelatin or a gelatin derivative and a cellulose ester, and the conductive material is either the layer (1) or the layer ( 2. The protective film for a polarizing plate as described in 1 above, which is contained in 2).

[0010] 3. The resin film has a layer containing a -COOM group-containing high molecular compound represented by the following general formula [1] or [2], a hydrophilic high molecular compound (a), gelatin or a gelatin derivative on at least one surface. 3. The protective film for a polarizing plate as described in 1 or 2 above.

[0011]

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In the formula, A is a repeating unit formed by polymerization of a vinyl monomer, B is a hydrogen atom, -CO-OM or-
Represents CO-R, M represents a hydrogen atom or a cation,
When z = 0, B is a hydrogen atom. R represents —O—R ′ or —N (R ′) (R ″), where R ′ forms a heterocyclic ring together with an alkyl group, an aralkyl group, an aryl group, a heterocyclic residue or R ″ R "represents a hydrogen atom, a lower alkyl group or a nonmetal atom necessary for forming a heterocyclic ring in cooperation with R ';
Each ₁ and R ₂ represents a hydrogen atom or a lower alkyl group, X represents -CO-O- or -O-CO-, R ₃
Represents a halogen-substituted alkyl group or a halogen-substituted alkyloxyalkyl group, and m, p, q, r, x, y, and z each represent a value indicating mol% of each monomer, and m and x each represent , 0 to 60, p, q, r, x, y and z are each 0 to 100, and m + p + q + r = 100, x +
y + z = 100.

4. 4. The protective film for a polarizing plate as described in 2 or 3, wherein the hydrophilic polymer compound (a) is a polyvinyl alcohol derivative, a hydrophilic cellulose derivative or a natural polymer.

5. 5. The protective film for a polarizing plate according to any one of 1 to 4, wherein the conductive material is mainly composed of an ionic polymer compound.

6. The conductive material is Sn, Ti, In, A
a metal oxide containing, as a main component, an element selected from the group consisting of 1, Zn, Si, Mg, Ba, Mo, W and V, and having a volume resistivity of 10 ⁷ Ω · cm or less. The protective film for a polarizing plate according to any one of the above items 1 to 5, wherein

[7] Primary particle size of metal oxide is 0.2
7. The protective film for a polarizing plate as described in 6 above, wherein the thickness is not more than μm.

8. 8. The protective film for a polarizing plate according to any one of the above items 1 to 7, wherein the conductive layer contains fine particles having an average particle size of 5.0 μm or less.

9. Any one of the above-mentioned items 1 to 8, wherein the resin film has a curl prevention layer on the other surface of the surface having the conductive layer, and the curl prevention layer comprises a composition containing a solvent. 2. The protective film for a polarizing plate according to claim 1.

10. The protective film for a polarizing plate according to any one of the above items 2 to 9, wherein the layer (1) or the layer (2) contains a crosslinking agent.

11. On the other side of the surface having the conductive layer on the resin film, a layer containing at least one hydrophilic polymer compound (a) or a layer containing at least one kind of gelatin or a gelatin derivative and a cellulose ester is provided. The protective film for a polarizing plate according to any one of the above items 1 to 10, which has the following.

[12] The hydrophilic polymer compound (a) is a polyvinyl alcohol derivative, a hydrophilic cellulose derivative or a natural polymer, and the cellulose ester is cellulose triacetate, cellulose diacetate, cellulose acetate propionate or cellulose acetate butyrate. 12. The protective film for a polarizing plate as described in 2, 3, 4 or 11 above.

13. The resin film is a cellulose ester film, a polycarbonate film, a polyester film or a polyacrylate film, and
13. The protective film for a polarizing plate according to any one of the above items 1 to 12, wherein the resin film has a light transmittance of 85% or more.

14. 14. The protective film for a polarizing plate according to any one of the items 1 to 13, wherein the resin film contains a cellulose ester.

[15] A polarizing plate, comprising the polarizing plate protective film according to any one of 1 to 14.

Hereinafter, the present invention will be described in detail. In the protective film for a polarizing plate of the present invention, on the resin film,
A conductive layer containing a conductive material and having a surface resistivity of 10 ¹¹ Ω / cm or less (23 ° C., 55% RH) is provided to provide an antistatic function. It improves the adhesion to the polarizer and other constituent layers during the production of the polarizing plate. As a result, foreign matter defects due to adhesion of dust and film cuttings due to static electricity during bonding are generated. In addition, the abnormal display of the liquid crystal of the polarizing plate was reduced.

The resin film according to the present invention will be described. As the resin film according to the present invention, for example, a cellulose ester film, a polycarbonate film,
Polyester films and polyacrylate films are preferably used.

Further, from the viewpoint of improving the brightness of the liquid crystal screen, the light transmittance of the resin film is preferably 85% or more.

In the present invention, the light transmittance was measured using a Shimadzu MPS-2000 and a wavelength of 500.
Measured in nm.

From the viewpoint of having sufficient mechanical strength at the time of molding, the number average molecular weight of the resin film according to the present invention is preferably in the range of 70,000 to 300,000, and more preferably 80,000 to 200,000.

In order to provide the conductive layer according to the protective film for a polarizing plate of the present invention with a function of easily adhering to a polarizer and / or other constituent layers, for example, the conductive layer may have a hydrophilic property. It is preferable to have a layer (1) containing at least one kind of the molecular compound (a) or a layer (2) containing at least one kind of gelatin or a gelatin derivative and a cellulose ester. It is preferably contained in the layer (1) or the layer (2).

The hydrophilic polymer compound (a) is preferably a hydrophilic cellulose derivative (eg, methylcellulose, carboxymethylcellulose, hydroxycellulose, etc.), a polyvinyl alcohol derivative (eg, polyvinyl alcohol, vinyl acetate-vinyl alcohol copolymer) , Polyvinyl acetal, polyvinyl formal,
Polyvinyl benzal, etc.), natural polymer compounds (eg, gelatin, casein, gum arabic, etc.), hydrophilic polyester derivatives (eg, partially sulfonated polyethylene terephthalate, etc.), hydrophilic polyvinyl derivatives (eg, poly- N-vinylpyrrolidone, polyacrylamide, polyvinylindazole, polyvinylpyrazole, etc.), among which hydrophilic cellulose derivatives, polyvinyl alcohol derivatives, natural polymer compounds and the like are more preferably used. Of course, the above derivatives can be used alone or in combination of two or more.

As the cellulose ester, cellulose triacetate, cellulose diacetate, cellulose acetate propionate or cellulose acetate butyrate is preferably used.

Further, in the protective film for a polarizing plate of the present invention, the polymer film having a -COOM group represented by the above general formula [1] or [2] on at least one surface of the resin film, Having a layer containing at least one of the hydrophilic polymer compound (a) and the above-mentioned gelatin or gelatin derivative, thereby improving the adhesiveness of the protective film for a polarizing plate to a polarizer and other polarizing plate constituent layers. Can be done.

In the above general formulas [1] and [2], examples of the vinyl monomer which forms the repeating unit represented by A include styrene, nitro group, fluorine atom,
Styrene, vinyl methyl ether, vinyl ethyl ether, vinyl chloroethyl ether, vinyl acetate, chloro substituted with chlorine atom, bromine atom, chloromethyl group, lower alkyl group (lower represents 1 to 5 carbon atoms), etc. Unsaturated acid such as vinyl acetate, vinyl propionate, acrylic acid, methacrylic acid or itaconic acid, alkyl ester of acrylic acid or methacrylic acid (the alkyl group has 1 to 5 carbon atoms, an unsubstituted alkyl group or chlorine atom, phenyl Phenyl ester of acrylic acid or methacrylic acid (the phenyl group is an unsubstituted phenyl group or a phenyl group substituted with a chlorine atom or a phenyl group), acrylonitrile, vinyl chloride, vinylidene chloride, ethylene, Acrylamide, 1-5 carbon atoms
Acrylamide, vinyl alcohol, chrysidyl acrylate, acrolein, and the like substituted with an alkyl group or chlorine, a phenyl group, and the like, preferably styrene, styrene having a substituent, vinyl acetate, vinyl methyl ether, alkyl acrylate, acrylonitrile, and the like. Can be

The alkyl group represented by R 'is preferably an alkyl group having 1 to 24 carbon atoms, and may be any of a linear alkyl group, a branched alkyl group and a cycloalkyl group, and the alkyl group has a substituent. It may be.

Examples of the substituent include a hydroxyl group, a hydroxycarbonyl group and a -COOM '(M' represents a cation) group, and particularly a halogen having 2 to 18 carbon atoms substituted by a halogen atom such as a fluorine atom. A substituted alkyl group or a halogen-substituted alkyloxyalkyl group having 2 to 18 carbon atoms is preferably used from the viewpoint of improving adhesion.
The number of halogen atoms substituted by the halogen-substituted alkyl group and the halogen-substituted alkyloxyalkyl group is preferably 1 to 37. The halogen-substituted alkyl group and the halogen-substituted alkyloxyalkyl group, and the halogen-substituted alkyl group and the halogen-substituted alkyloxyalkyl group represented by R ₃ in the general formula [2] are preferably represented by the following general formula [A].

[0037]

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In the formula, R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ each represent a hydrogen atom or a fluorine atom;
And n2 is 0 or 1, n1 is 0 when n2 is 0, n1 is 2 or 3 when n2 is 1, and n3 is an integer of 1 to 17. However,
n1 + n3 is 1-17. When there are two or more R ₄ in the general formula [A], they may be the same or different. Similarly, when there are a plurality of R ₅ , R ₆ and R ₇ in the general formula [A], they may be the same or different.

In the general formulas [1] and [2], when R 'is a halogen-substituted alkyl group or a halogen-substituted alkyloxyalkyl group as described above, R in the general formula [1] is preferably —OR ′.

The heterocyclic ring represented by R 'or the heterocyclic ring formed by R' and R "is preferably a saturated or unsaturated heterocyclic ring containing an oxygen atom, a sulfur atom or a nitrogen atom, such as aziridine, pyrrole and pyrrolidine. , Pyrazole,
Examples include a heterocycle selected from heterocycles such as imidazole, imidazoline, triazole, piperidine, piperazine, oxazine, morpholine, and thiazine.

The cation represented by M includes, for example, ammonium ion, sodium ion, potassium ion, lithium ion and the like.

The -COOM group-containing high molecular compound represented by the above general formula [1] or [2] may be used alone or in combination of two or more thereof. Alternatively, the molecular weight of the -COOM group-containing polymer compound represented by [2] may be an average molecular weight of about 500 to 50.
Those having a molecular weight of about 000 (weight average molecular weight) are preferably used.

Hereinafter, specific examples of the high molecular compound having a -COOM group represented by the general formula [1] or [2] will be given.
The present invention is not limited to these.

[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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The conductive material according to the present invention will be described. As the conductive material according to the present invention, an ionic polymer compound, a metal oxide or the like is preferably used.

As the ionic polymer compound, Japanese Patent Publication No. Sho 4
9-23828, 49-23827, 47-2
Anionic polymer compounds as found in No. 8937;
JP-B-55-734, JP-A-50-54672, JP-B-59-14735, JP-B-57-18175, and JP-A-57-17575.
Ionene-type polymers having a dissociating group in the main chain, such as those described in JP-A Nos. 7-18176 and 57-56059; JP-B-53-13223 and JP-B-57-15376.
No., JP-B No. 53-45231, and No. 55-145783
No. 55-65950, No. 55-67746, No. 57-11342, No. 57-19735, Japanese Patent Publication No. 5
No. 8-56858, JP-A-61-27853, JP-A-62-28585.
9346, a cationic pendant polymer having a cationic dissociating group in the side chain.

Particularly preferred ionic polymer compounds include polymers having units of the following general formulas [3], [3a] and [3b].

[0052]

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[0053]

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In the formula, R ₃ , R ₄ , R ₅ and R ₆ each represent a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and R ₃ and R ₄ and / or R ₅ and R ₆ are bonded to each other. A nitrogen-containing heterocycle such as piperazine may be formed. A, B and D each represent a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, an arylene group, an alkenylene group, an arylene alkylene group,
_{-R 7 COR 8 -, - R} 9 COOR 10 OCOR 11 -, - R
_{12 OCR 13 COOR 14 -, -} R 15 - (OR 16) m -, -
_{R 17 CONHR 18 NHCOR 19 -,} - R 20 OCONHR
₂₁ NHCOR ₂₂ -or -R ₂₅ NHCONHR ₂₄ NHC
ONHR ₂₅ - represents a. R ₇ , R ₈ , R ₉ , R ₁₁ , R ₁₂ , R
_{14, R 15, R 16,} R 17, R 19, R 20, R 2 2, R 23 and R ₂₅ is an alkylene _{group, R 10, R 13, R} 18, R 21 and R
₂₄ is a linking group selected from a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylenealkylene group, and alkylenearylene group;
Represents a positive integer, and X ⁻ represents an anion.

However, when A is an alkylene group, a hydroxyalkylene group or an arylenealkylene group, it is preferred that B is not an alkylene group, a hydroxylalkylene group or an arylenealkylene group.

E is a mere bond, —NHCOR ₂₆ CON
Represents a group selected from H- or D. R ₂₆ represents a substituted or unsubstituted alkylene group, alkenylene group, arylene group, arylenealkylene group, or alkylenearylene group.

Z ₁ and Z ₂ each represent a nonmetallic atom group (≡N + [X
-]-May be linked to E in the form of a quaternary salt.

N represents an integer of 5 to 300. Further, in the present invention, the following general formulas [3], [3a], [3b]
An ionic polymer compound having a unit represented by the following formula is preferably used. Hereinafter, specific examples of the ionic polymer compound according to the present invention will be described, but the present invention is not limited thereto.

[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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The ionic polymer compound may be used alone, or may be used in combination of several kinds of ionic polymer compounds. The content of the ionic polymer compound according to the present invention in the protective film for a polarizing plate is preferably from 0.005 g to 2.0 g / m ² , and particularly preferably from 0.01 g to 1.0 g / m ² . .

Examples of the metal oxide include a metal oxide having conductivity. Examples of metal oxides include Sn,
Ti, In, Zn, Al, Si, Mg, Ba, Mo, W
And V as the main components, and have a volume resistivity of 10 ⁷ Ω /
cm (25 ° C., 20% RH), or a composite oxide of these metals, with ZnO, TiO ₂ and SnO ₂ being particularly preferred. Examples of including heteroatoms include, for example, addition of Al and In to ZnO, and Nb and Ta to TiO ₂ .
And the like, and addition of Sb, Nb, a halogen element and the like to SnO ₂ are effective. The addition amount of these different atoms is preferably in the range of 0.01 mol% to 25 mol%, and particularly preferably in the range of 0.1 mol% to 15 mol%.

The volume resistivity of these conductive metal oxide powders is preferably 10 ⁷ Ωcm,
Particularly preferably, it is 10 ⁵ Ωcm or less, and the primary particle diameter is preferably 10 nm to 0.2 μm, and the powder having a specific structure in which the major axis of the higher-order structure is 30 nm to 6 μm is used for the conductive layer. It is preferable to contain 0.01% to 20% or less in volume fraction.

In order for the conductive layer of the protective film for a polarizing plate of the present invention to exhibit a sufficient antistatic effect and to maintain a sufficient easy adhesion, the hydrophilic polymer compound (a) or The amount of the conductive material based on at least one of gelatin or a gelatin derivative and cellulose ester is preferably 20% to 300%, more preferably 30% to 200%.

Further, in the present invention, fine particles may be added to the conductive layer, for example, fine particles containing silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, etc. as constituents. Can be given.

The fine particles described above have an average particle size of 0.01
10 μm to 10 μm, more preferably 0.01 to 5 μm
m, 0.05 to 10 by mass ratio to the solid content in the coating composition
Parts are preferred, with 0.1 to 5 parts being particularly preferred.

The crosslinking agent according to the present invention will be described. As a crosslinking agent, metal oxides, for example, aluminum oxide,
Boric acid, cobalt oxide and the like are preferred. A compound having a vinyl sulfone group such as meta-xylene vinyl sulfonic acid; a compound having an epoxy group such as bisphenol glycidyl ether; a compound having an isocyanate group; a compound having a blocked isocyanate group; Compounds having an active halogen group such as chlorotriazine and 2-sodiumoxy-4,6-dichlorotriazine, compounds having an aldehyde group such as formaldehyde and glyoxal, mucochloric acid, tetramethylene-1,4-bis (ethyleneurea) And compounds having at least one group selected from compounds having an ethyleneimine group, such as hexamethylene-1,6-bis (ethyleneurea), and compounds having an active ester-forming group. Combined use of the above crosslinking agents Good.

Among these, a metal oxide, a compound having a vinyl sulfone group, a compound having an ethyleneimine group, a compound having an epoxy group, and a compound having an aldehyde group are particularly preferable.

In the present invention, the compound having a vinylsulfone group is a compound having a vinyl group bonded to a sulfonyl group or a group having a group capable of forming a vinyl group, preferably a vinyl group or a vinyl group bonded to a sulfonyl group. A compound having at least two groups that can be formed and represented by the following general formula [4] is preferable.

Formula (4) (CH ₂ ＣＨCHSO ₂ ) _n A In the formula, A is an n-valent linking group, for example, an alkylene group,
It is a substituted alkylene group, a phenylene group, or a substituted phenylene group, and may have an amide linkage, an amino linkage, an ether linkage, or a thioether linkage in between. As the substituent, a halogen atom, a hydroxyl group, a hydroxyalkyl group, an amino group, a sulfonic acid group,
Sulfate groups and the like. n is 1, 2, 3 or 4.

Typical examples of the vinyl sulfone crosslinking agent are shown below, but the present invention is not limited to these.

[0077]

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[0078]

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As the compound having an ethyleneimine group, a compound having a bifunctional or trifunctional structure and a molecular weight of 700 or less is particularly preferably used. Specific examples of the crosslinking agent having an ethyleneimine group are shown below, but the present invention is not limited thereto.

[0080]

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[0081]

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The compound having an epoxy group is particularly preferably a compound having two or more epoxy groups and having a molecular weight of 300 or less per functional group. Specific examples of the crosslinking agent having an epoxy group are shown below, but the present invention is not limited thereto.

[0083]

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[0084]

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The use amount of the crosslinking agent according to the present invention varies depending on the cellulose ester film to be applied, but is preferably 0.1 to 10% by mass, and more preferably 1 to 8% by mass of the added polysaccharide.

The resin film according to the present invention may contain various additives, for example, a plasticizer, an antioxidant, a dye (a coloring agent, etc.) can be used.

The content of the above-mentioned additives in the resin film is preferably from 10 to 1,000 ppm by mass, more preferably from 50 to 500 ppm.

For a liquid crystal display device, it is preferable to add a plasticizer, an antioxidant, an ultraviolet inhibitor or the like for imparting heat and moisture resistance. As a method of adding additives,
When preparing the solution of the resin film, it may be added together with the resin film or the solvent, or may be added during or after the solution is prepared. Further, a substance previously dissolved in an organic solvent may be added to the dope composition.

As the antioxidant described above, hindered phenol compounds are preferably used.
Di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t- Butyl-5-methyl-
4-hydroxyphenyl) propionate], 1,6-
Hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,
4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-
Triazine, 2,2-thio-diethylenebis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], octadecyl-3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-
Butyl-4-hydroxy-hydrocinnamamide), 1,
3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanu Late and the like. In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-
Tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4
-Hydroxyphenyl) propionate] is preferred.
Further, for example, N, N'-bis [3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionyl] hydrazine and other hydrazine-based metal deactivators;
A phosphorus-based processing stabilizer such as 4-di-t-butylphenyl) phosphite may be used in combination. The addition amount of these compounds is from 1 ppm to 1.
0% is preferable and 10 to 1000 ppm is more preferable. In addition, a heat stabilizer such as inorganic fine particles such as kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide, and alumina, and salts of alkaline earth metals such as calcium and magnesium may be added. .
Further, an antistatic agent, a flame retardant, a lubricant, an oil agent and the like may be added in some cases.

As the plasticizer, phthalic esters, phosphoric esters, alkylphthalylalkyl glycolates, citric esters, adipic esters, trimellitic esters and the like are preferably used. For example, methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl glycolate, ethyl phthalyl methyl glycolate , Ethyl phthalyl propyl glycolate, propyl phthalyl ethyl glycolate, methyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, Propyl phthalyl butyl glycolate, butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate,
Octyl phthalyl methyl glycolate, octyl phthalyl ethyl glycolate, methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate,
Triphenyl phosphate, tricresyl phosphate, phenyl diphenyl phosphate, dimethyl phthalate, diethyl phosphate, dioctyl phthalate,
Examples include diethylhexyl phthalate, acetyl triethyl citrate, acetyl tributyl citrate, butyl oleate, methyl acetyl ricinoleate, dibutyl sebacate, and triacetin. The content of these plasticizers in the resin film is preferably 1 to 30% by mass, more preferably 5 to 20%. Further, when the additive is a plasticizer having a melting point higher than 350 ° C. under the atmospheric pressure, the interaction between the plasticizers works stronger than the interaction between the plasticizer and the resin film, and the non-chlorine-based organic material of the resin film. 350 ° C due to reduced solubility in solvents
Plasticizers having the following boiling points are preferably used.

Examples of the plasticizer having a boiling point of 350 ° C. or less include ethylphthalylethyl glycolate, dimethylphthalate,
Examples include diethyl phthalate, dibutyl phthalate, and dioctyl adipate.

As the above-mentioned ultraviolet ray inhibitor, a wavelength of 370 nm
From the viewpoints of the following ultraviolet absorbing ability and good liquid crystal display properties, those having little absorption of visible light having a wavelength of 400 nm or more are preferable. The content is preferably from 0.2 g to 3 g per 1 m ² of the resin film, more preferably,
0.5 g to 2 g.

Specific examples of these ultraviolet absorbers preferably used in the present invention include oxybenzophenone compounds, benzotriazole compounds, salicylate compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds and the like. No.

As the benzotriazole ultraviolet absorber, a compound represented by the following general formula [5] is preferably used.

[0095]

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In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ may be the same or different and include a hydrogen atom, a halogen atom, a nitro group, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, and an alkoxy group. group, an acyloxy group, an aryloxy group, an alkylthio group, an arylthio group, a mono- or dialkylamino group, an acylamino group or a 5- to 6-membered heterocyclic group, the carbon of R ₄ and R ₅ are 5- or 6-membered ring closure A ring may be formed.

Specific examples of the ultraviolet absorbent according to the present invention are shown below, but the present invention is not limited to these.

UV-1: 2- (2'-hydroxy-5 '
-Methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-
tert-butylphenyl) benzotriazole UV-3: 2- (2'-hydroxy-3'-tert-
Butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-
tert-butylphenyl) -5-chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ",
4 ", 5", 6 "-tetrahydrophthalimidomethyl)
-5'-methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,
3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol) UV-7: 2- (2'-hydroxy-3'-tert-
(Butyl-5'-methylphenyl) -5-chlorobenzotriazole A compound represented by the following general formula [6] is preferably used as a benzophenone-based ultraviolet absorber which is one of the ultraviolet absorbers according to the present invention.

[0099]

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In the formula, Y represents a hydrogen atom, a halogen atom or an alkyl group, an alkenyl group, an alkoxy group and a phenyl group, and these alkyl group, alkenyl group and phenyl group may have a substituent. A is a hydrogen atom,
Represents an alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, an alkylcarbonyl group, an alkylsulfonyl group or a -CO (NH) _n-1 -D group, wherein D is an alkyl group,
Represents an alkenyl group or a phenyl group which may have a substituent. m and n represent 1 or 2.

In the above, the alkyl group is, for example, a linear or branched aliphatic group having up to 24 carbon atoms, the alkoxy group is, for example, an alkoxy group having up to 18 carbon atoms, and the alkenyl group is, for example, carbon atom. Number 1
The alkenyl group up to 6 represents, for example, an allyl group, a 2-butenyl group and the like. Examples of the substituent to the alkyl group, alkenyl group, and phenyl group include a halogen atom, for example, a chlorine atom, a bromine atom, a fluorine atom, etc., a hydroxyl group, a phenyl group (the phenyl group is substituted with an alkyl group or a halogen atom, etc.). May be used).

The specific examples of the benzophenone-based compound represented by the general formula [2] are shown below, but the present invention is not limited thereto.

UV-8: 2,4-dihydroxybenzophenone UV-9: 2,2'-dihydroxy-4-methoxybenzophenone UV-10: 2-hydroxy-4-methoxy-5-sulfobenzophenone UV-11: bis ( 2-methoxy-4-hydroxy-5
-Benzoylphenylmethane) The above-mentioned ultraviolet absorber preferably used in the present invention is a benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber having high transparency and an excellent effect of preventing deterioration of a polarizing plate or a liquid crystal element. A benzotriazole-based ultraviolet absorber which causes less unnecessary coloring is particularly preferable.

Regarding the distribution of the ultraviolet absorbent in the film, the ultraviolet absorbent moves to the surface together with the plasticizer in the drying step or the heat treatment step, thereby contaminating the step or causing an appearance failure due to reattachment and the like. The content of the ultraviolet absorber is preferably such that the concentration on the film surface side is lower than the average concentration of the entire film.

[0105]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto.

Example 1 << Preparation of Protective Film Sample 1 for Polarizing Plate >> Cellulose triacetate film having a thickness of 80 μm (manufactured by Konica Corporation, trade name: Konica Cat KC80UVSF (hereinafter TA))
C), the lower layer liquid (1) having the following composition
0 ml / m ² , and 25 ml of the upper layer liquid (1) having the following composition
/ M ² in this order and dried at 100 ° C. for 5 minutes, respectively. Then, the coating liquid (1) for the anti-curl layer having the following composition is applied to the opposite surface in a film thickness such that the curl degree is +1 (1).
(00 ° C., 5 minutes) to prepare a protective film sample 1 for a polarizing plate.

<< Preparation of Lower Layer Liquid (1) >> Compound (14) 0.5 g Acetone 40 ml Ethyl acetate 50 ml Isopropyl alcohol 10 ml << Preparation of Upper Layer Liquid (1) >> Polyvinyl alcohol (PVA) (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) , Trade name: Gohsenol NH-26) 0.1 g Conductive material (IP-11) 0.15 g Saponin (manufactured by Merck Ltd., surfactant) 0.03 g Crosslinking agent (glyoxal) 0.025 g Pure water 55 ml Methanol 40 ml Isopropyl alcohol 5 ml << Preparation of coating solution (1) for anti-curl layer >> Cellulose diacetate (manufactured by Daicel Corporation, trade name: acetate flake L-50) 0.5 g 2% acetone-dispersed fine particle silica (ultrasonic dispersion) (Nippon Aerosil Co., Ltd., trade name: Aerosil 200) 0.2 g 40 ml of ethyl acetate 55 ml of isopropyl alcohol 5 ml << Preparation of Protective Film Sample 2 for Polarizing Plate >> Protective film sample for polarizing plate 1 except that the upper layer solution (1) of Example 1 was replaced with the upper layer solution (2) having the following composition. In the same manner as in the above, protective film sample 2 for a polarizing plate was produced.

<< Preparation of Upper Layer Liquid (2) >> Polyvinyl alcohol (PVA) (trade name: Gohsenol NH-26, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 0.2 g Conductive material (IP-15) 0.3 g Crosslinking (Glyoxal) 0.025 g saponin (manufactured by Merck Ltd., surfactant) 0.03 g pure water 58 ml methanol 40 ml diethylene glycol 2 ml << Preparation of polarizing plate protective film sample 3 >> 75 μm thick polyethylene terephthalate film (Diafoil) (Product name: Diamond Foil, hereinafter abbreviated as PET)
Is subjected to a corona discharge treatment under the condition of 20 W / m ² · min, and then the lower layer liquid (2) having the following composition and the upper layer liquid (3) having the following composition are 20 ml / m ² and 25 ml, respectively.
/ M ² in this order and dried at 100 ° C. for 5 minutes, respectively, to prepare a polarizing plate protective film sample 3 which is a polarizing plate protective film.

<< Preparation of Lower Layer Liquid (2) >> Compound (14) 0.4 g Polyester resin (manufactured by Toyobo Co., Ltd., trade name: Byron # 200) 0.1 g acetone 40 ml methyl ethyl ketone 50 ml dimethylformamide 10 ml << upper layer liquid ( Preparation of 3) >> Polyvinyl alcohol (PVA) (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: Gohsenol NH-26) 0.3 g Conductive material (IP-4) 0.2 g Saponin (manufactured by Merck Ltd.) (Surfactant) 0.03 g Cross-linking agent (glyoxal) 0.03 g Pure water 70 ml Methanol 30 ml << Preparation of protective film sample 4 for polarizing plate >> A 75 μm-thick polycarbonate film (manufactured by Lonza Japan Co., Ltd.)
(Trade name: optical grade polycarbonate film, hereinafter abbreviated as PC)) is subjected to a corona discharge treatment on one surface under a condition of 50 W / m ² · min, and then 20 ml of a lower layer liquid (3) having the following composition is applied to the corona discharge treated surface. / M ² , and 30 ml / m ^{2 of the} same upper layer liquid (1) as used in Example 1 were applied in this order, and dried at 100 ° C. for 5 minutes to prepare a protective film sample 4 for a polarizing plate.

<< Preparation of Lower Layer Solution (3) >> Compound (14) 0.5 g Ethyl acetate 40 ml Acetone 50 ml Dimethylformamide 10 ml << Preparation of protective film sample 5 for polarizing plate >> With a film thickness of 50 μm
Was manufactured in the same manner except that the acrylate film (manufactured by Nippon Carbide Co., Ltd .; hereinafter abbreviated as PMMA) was used.

<< Preparation of Protective Film Sample 6 for Polarizing Plate >> Upper Layer Liquid (1) Used for Producing Protective Film Sample 1 for Polarizing Plate
Was replaced with the upper layer solution (4) of the following composition to prepare a protective film sample for polarizing plate 6 in the same manner as in the preparation of the protective film sample for polarizing plate 1.

<< Preparation of Upper Layer Liquid (4) >> Polyvinyl alcohol (PVA) (trade name: Gohsenol NH-26, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 0.2 g Conductive material (IP-22) 0.3 g Saponin (Surfactant, manufactured by Merck Ltd.) 0.03 g Pure water 58 ml Methanol 40 ml Diethylene glycol 2 ml << Preparation of protective film sample 7 for polarizing plate >> The TAC film used for preparing protective film sample 1 for polarizing plate was subjected to the following method. The protective film sample 7 for a polarizing plate was produced in the same manner as the production of the protective film sample 1 for a polarizing plate except that the lower solution (1) was replaced with the lower solution (4) having the following composition in place of the TACF produced in the above. .

<< Production of TACF >> A TAC film containing fine particles (abbreviated as TACF) was produced by the following steps.

(Preparation of Fine Particle Dispersion) Ethanol 27 L Fine particles (silicon dioxide, trade name: Aerosil 200V, primary particle diameter 15 nm, manufactured by Nippon Aerosil Co., Ltd.) 300 g 500
After preliminarily dispersing at 30 rpm for 30 minutes, the particles were dispersed at a pressure of 19.613 MPa with a Manton-Gaulin type high-pressure disperser to prepare a fine particle dispersion.

(Preparation of Additive Solution A) 22 parts of the above fine particle dispersion liquid cellulose triacetate synthesized from cotton linter (degree of acetylation: 61.0%) 12 parts 2- (2′-hydroxy-3 ′, 5′-di) -T-butylphenyl) benzotriazole (ultraviolet absorber) 26 parts methylene chloride 29 parts For the above-mentioned additive liquid A, a centrifugal particle size distribution analyzer (CAP)
The average particle diameter of the fine particles (silicon dioxide) was 1.2 μm as measured by A500 (manufactured by Horiba, Ltd.).

(Preparation of Dope Composition A) Cellulose triacetate synthesized from cotton linter (degree of acetylation: 61.0%) 85 parts Cellulose triacetate synthesized from wood pulp (degree of acetylation: 61.0%) 15 parts Ethyl Phthalylethyl glycolate (plasticizer) 4 parts Methylene chloride 475 parts Ethanol 50 parts The above-mentioned compound is charged into a closed container, heated to 70 ° C, and stirred with cellulose triacetate (TAC).
Was completely dissolved to obtain a dope composition A. The time required for dissolution was 4 hours. After filtering the dope composition A, the content of the fine particles with respect to cellulose triacetate was 0.1%.
After mixing the dope composition A and the additive solution A with the in-line mixer so as to be 0.05% by mass, the mixture was uniformly cast on a stainless steel belt support at a dope temperature of 35 ° C. and 30 ° C. using a belt casting apparatus. . After drying to a range where the peeling was possible, the dope was peeled off from the stainless steel belt support.
At this time, the residual solvent amount of the dope was 25%. The time required from dope casting to peeling was 3 minutes.

The residual solvent amount of the dope according to the present invention is defined by the following equation. Residual solvent amount = (mass before heat treatment of dope−mass after heat treatment of dope) / (mass after heat treatment of dope) × 100
% The heat treatment for measuring the residual solvent amount is 115 ° C.
Represents that heat treatment is performed for one hour.

After the dope film was separated from the stainless steel belt support, the first zone was 50 ° C., the second zone was 90 ° C., and the third zone 1
After passing through a drying zone at 20 ° C., drying was further completed in a drying and heating zone at 130 ° C., and both ends of the film were subjected to knurling with a width of 10 mm and a height of 4 μm to prepare a cellulose triacetate film sample 1 having a thickness of 40 μm. The film width was adjusted to 1300 mm and the winding length was adjusted to 3000 m. The winding tension is 196 N / initial tension.
The final tension was 1300 mm and the final tension was 98 N / 1300 mm.

<< Preparation of Lower Layer Solution (4) >> Gelatin 1 g Cellulose diacetate (DAC, manufactured by Daicel Corporation, trade name: acetate flake L-50) 0.7 g Crosslinking agent (glyoxal) 0.01 g Glacial acetic acid 2 ml Pure Water 3 ml Methanol 27 ml Acetone 68 ml << Preparation of Protective Film Sample 8 for Polarizing Plate >> Except for replacing the lower layer solution (5) having the following composition with the upper layer solution (4) used in preparing the protective film sample 6 for polarizing plate. In the same manner as in the preparation of the protective film sample 3 for a polarizing plate, a protective film sample 8 for a polarizing plate was prepared.

<< Preparation of Conductive Fine Particle Dispersion Composition >> Conductive SnO ₂ antimony composite fine particles (manufactured by Mitsubishi Materials Corp., primary particles: 0.015 nm) 200 g Nitrocellulose 5 g Methyl ethyl ketone 150 g The above composition was prepared using a sand mill. Time dispersed.

Using the conductive fine particle dispersion composition prepared as described above, a lower layer solution (5) having the following composition was prepared.

<< Lower Layer Liquid (5) >> Compound (14) 0.4 g Polyester resin (manufactured by Toyobo Co., Ltd., trade name: Byron # 200) 0.2 g Conductive fine particle dispersion composition 0.6 g Crosslinking agent (glyoxal) 0.08 g Acetone 65 ml Methanol 25 ml Methyl cellosolve 10 ml << Preparation of protective film sample 9 for polarizing plate >> The lower layer solution (3) used for preparing the protective film sample 4 for polarizing plate was changed to the lower layer solution (6) having the following composition. And the upper layer liquid having the following composition (5)
A protective film sample 9 for a polarizing plate was prepared in the same manner as in the preparation of the protective film sample 4 for a polarizing plate, except for replacing the above.

<< Preparation of Underlayer Liquid (6) >> Compound (14) 0.4 g Conductive material (IP-11) 0.2 g 2% acetone-dispersed fine particle silica (trade name: ultrasonic dispersion (trade name, manufactured by Nippon Aerosil Co., Ltd.) : Aerosil 200)) 0.2 g Saponin (manufactured by Merck Ltd., surfactant) 0.03 g Crosslinking agent (glyoxal) 0.05 g Pure water 55 ml Methanol 40 ml Isopropyl alcohol 5 ml << Preparation of upper layer solution (5) >> polyvinyl alcohol (PVA) (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: Gohsenol NH-26) 0.3 g Saponin (manufactured by Merck Ltd., surfactant) 0.03 g Crosslinking agent (glyoxal) 0.025 g Pure water 55 ml 40 ml of methanol 5 ml of isopropyl alcohol << Preparation of protective film sample 10 for polarizing plate >> Changing the lower layer solution used in the production of Lum sample 5 in the lower layer solution having the following composition (7), a protective upper layer liquid polarizer film sample 9
Was prepared in the same manner as in the preparation of the polarizing plate protective film sample 5, except that the upper layer liquid (5) used in the preparation was used.

<< Preparation of Lower Layer Liquid (7) >> Compound (14) 0.5 g Emulsion-type acrylic resin (Nippon Carbide Industry Co., Ltd., trade name: Nicazole A-08) 0.2 g Conductive material (IP- 15) 0.3 g Crosslinking agent (glyoxal) 0.05 g Acetone 40 ml Ethyl acetate 20 ml Methanol 30 ml Pure water 10 ml << Preparation of protective film sample 11 for polarizing plate >> The upper layer liquid used for preparing protective film sample 1 for polarizing plate is as follows. Protective film sample for polarizing plate 1 except that the composition was replaced with the upper layer liquid (6)
In the same manner as in the preparation of the above, a protective film sample for polarizing plate 11 was prepared.

<< Preparation of Upper Layer Liquid (6) >> Hydroxypropyl methylcellulose phthalate (trade name: HP-55, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 g Conductive material (IP-22) 0.2 g Saponin (Merck ( 0.03 g Crosslinking agent (glyoxal) 0.03 g Acetone 30 ml Methanol 60 ml Isopropyl alcohol 10 ml << Preparation of protective film sample 12 for polarizing plate >> Instead of applying the layer coating solution, a composition containing an ultraviolet curable resin having the following composition is applied to a dry film thickness of 4 μm, dried at 80 ° C. for 5 minutes, and then 10 cm under a 60 W / cm high pressure mercury lamp.
Was cured for 4 seconds from the above distance, and a protective film sample for polarizing plate 12 was prepared in the same manner as in the preparation of the protective film sample for polarizing plate 1 except that a hard coat cured coating layer was provided.

<< Preparation of UV Curable Resin Composition (A) >> Dipentaerythritol hexaacrylate monomer 60 g Dipentaerythritol hexaacrylate dimer 20 g Dipentaerythritol hexaacrylate trimer and higher components 20 g Diethoxybenzophenone UV Initiator 3 g Silicone surfactant 1 g Methyl ethyl ketone 75 g Methyl propylene glycol 75 g When the pencil hardness of the cured coating layer of protective film sample 12 for polarizing plate was measured, it showed a hardness of 3H and exhibited a scratch resistance effect.

<< Preparation of Protective Film Sample 13 for Polarizing Plate >>
In the preparation of the polarizing plate protective film sample 1, instead of applying the curl preventing layer coating solution, the following antistatic layer coating solution composition (1) was applied so as to be 20 μm / m ² ,
After drying at 80 ° C. for 5 minutes, the antistatic layer (1) was provided, and the ultraviolet-curable resin composition (A) used for preparing the polarizing plate protective film sample 12 was further applied on the antistatic layer (1). A protective film sample 13 for a polarizing plate was prepared in the same manner as in the preparation of the protective film sample 1 for a polarizing plate, except that a cured film was formed in the same manner as in the preparation of the protective film sample 12 for a polarizing plate.

<< Preparation of Antistatic Layer Coating Liquid Composition (1) >> Conductive material (IP-20, 5% methanol dispersion, average particle size 0.2 μm) 10 ml Polymethyl methacrylate resin (manufactured by Mitsubishi Rayon Co., Ltd.) 0.5 g methyl propylene glycol 65 ml methyl ethyl ketone 20 ml ethyl lactate 5 ml << Preparation of Protective Film Sample 14 for Polarizer >> Ultraviolet-curable hard coat layer as in the preparation of Protective Film Sample 12 for polarizer And a protective film sample for polarizing plate 14 was prepared in the same manner as in the preparation of the protective film sample for polarizing plate 12 except that an antireflection layer having the following composition was further provided thereon.

The following composition A for a medium refractive index layer was applied on the hard coat layer and dried at 80 ° C. for 20 minutes. Next, a 3 kW high-pressure mercury lamp was irradiated from a distance of 25 cm for 10 seconds to cure, thereby providing a medium refractive index layer. Incidentally, the thickness of the middle refractive index layer was 80 nm, and the refractive index was 1.66. still,
In the present invention, the measurement of the refractive index is performed by an automatic birefringence meter KO.
Using a BRA-21DH (manufactured by KS Systems) under the environment of 23 ° C. and 55% RH, a wavelength of 590 n
It was measured by irradiating m light.

<< Composition A for Medium Refractive Index Layer >> Titanium tetra-n-butoxide 30 g Diethoxybenzophenone (ultraviolet initiator) 0.1 g γ-methacryloxypropyltrimethoxysilane 5 g cyclohexanone 1400 g isopropyl alcohol 3500 g Composition B for high refractive index layer having the following composition on the medium refractive index layer
Was applied and dried at 80 ° C. for 5 minutes. Then, 3kW
Was irradiated for 10 seconds from a distance of 25 cm from the high-pressure mercury lamp to cure, thereby providing a high refractive index layer. The thickness of the high refractive index layer is 8
At 5 nm, the refractive index was 1.90.

<< Composition B for High Refractive Index Layer >> Titanium tetra-n-butoxide 75 g Tetraethoxysilane 8.3 g Surfactant (F-177 manufactured by Dainippon Ink Co., Ltd.) 1 g Cyclohexanone 2500 g Toluene 5700 g A fluorine-containing monomer composition having the following composition was applied on the high refractive index layer, and dried at 80 ° C. for 5 minutes. Next, a 3 kW high-pressure mercury lamp was irradiated for 10 seconds from a distance of 25 cm to cure, thereby providing a low refractive index layer. In addition, the thickness of the low refractive index layer was 90 nm, and the refractive index was 1.37.

<< Fluorine-Containing Monomer Composition (Composition C for Low Refractive Index Layer) >> Methacrylic acid-3,3,4,4,5,5,6,6-octafluorohexyl 45 g Diacrylic acid-2,2 , 3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl ethylene glycol 45 g dipentaerythritol hexaacrylate (photopolymerizable monomer) 10 g Surfactant (F-177 manufactured by Dainippon Ink and Chemicals, Inc.) 1 g Cyclohexanone 3500 g Isopropyl alcohol 7700 g As described above, TAC-ultraviolet curable hard coat layer-medium refractive index layer-high refractive index layer-low refractive index A protective film sample 14 for a polarizing plate comprising a layer was produced. When the reflectance of the obtained protective film sample for polarizing plate 14 was measured, the reflectance was 0.1%, and a large antireflection effect was recognized.

<< Preparation of Protective Film Sample 15 for Polarizing Plate >>
A protective film sample for a polarizing plate 15 was prepared in the same manner as in the production of the protective film sample for a polarizing plate 13 except that the composition containing the ultraviolet-curable resin used for preparing the protective film sample for a polarizing plate 13 was changed to the following composition. Produced.

<< Preparation of UV Curable Resin Composition (B) >> Dipentaerythritol hexaacrylate monomer 50 g Dipentaerythritol hexaacrylate dimer 20 g Dipentaerythritol hexaacrylate trimer and higher components 20 g 1,4- Butanediol diglycidyl ether 10 g Diethoxybenzophenone (UV polymerization initiator) 3 g Aromatic sulfonium salt UV initiator 0.5 g Silicone surfactant 1 g Silica fine particles (average particle size of 4.5 μm) 2 g Hydrophobic silica fine particles (Average particle size: 0.01 μm) 2 g Methyl ethyl ketone 50 g Ethyl acetate 50 g Isopropyl alcohol 50 g The above-described composition is stirred by a high-speed stirrer (TK homomixer, manufactured by Tokushu Kika Kogyo 8 Co., Ltd.), and then the collision type dispersion machine (Menton Gawley, It was dispersed by Rin Co., Ltd.). When the haze value of the obtained protective film sample for polarizing plate 15 was measured, it was 8%, and an antiglare effect without reflection of a fluorescent lamp was recognized. In the present invention, the antiglare effect means that light is scattered on the surface of the layer by providing a structure having irregularities on the surface of the layer.

<< Preparation of Protective Film Sample 16 for Polarizing Plate >>
Protective film sample for polarizing plate 1 except that a conductive material (IP-20) was used instead of the conductive material (IP-11) from the upper layer liquid (1) used for producing the protective film sample 1 for polarizing plate. In the same manner as in the preparation of above, protective film sample 16 for polarizing plate was prepared.

<< Preparation of Polarizing Plate Protective Film Sample 17 (Comparative Sample) >> Polarization was performed except that the conductive material (IP-11) was removed from the upper layer liquid (1) used for preparing the polarizing plate protective film sample 1. In the same manner as in the preparation of the protective film sample 1 for a plate, a protective film sample 17 for a polarizing plate was prepared.

<< Preparation of Polarizing Plate Protective Film Sample 18 (Comparative Sample) >> Polarization was performed except that the conductive material (IP-4) was removed from the upper layer liquid (3) used for preparing the polarizing plate protective film sample 3. In the same manner as in the preparation of the protective film sample 3 for a plate, a protective film sample 18 for a polarizing plate was prepared.

<< Preparation of Polarizing Plate Protective Film Sample 19 (Comparative Sample) >> The upper layer liquid (1) used in preparing the polarizing plate protective film sample 4 was used in preparing the polarizing plate protective film sample 9. A protective film sample 19 for a polarizing plate was prepared in the same manner as in the preparation of the protective film sample 4 for a polarizing plate, except that (5) was used.

<< Preparation of Polarizing Plate Protective Film Sample 20 (Comparative Sample) >> Polarization was performed except that the conductive material (IP-11) was removed from the upper layer liquid (1) used for preparing the polarizing plate protective film sample 5. In the same manner as in the preparation of the protective film sample 5 for a plate, a protective film sample 20 for a polarizing plate was prepared.

<< Preparation of Protective Film Sample for Polarizing Plate Sample 21 (Comparative Sample) >> Protective Film Sample for Polarizing Plate Sample 1 except that polyvinyl alcohol was removed from the upper layer liquid (1) used for preparing the protective film sample for polarizing plate 1. In the same manner as in the preparation of above, a protective film sample for polarizing plate 21 was prepared.

<< Preparation of Protective Film Sample for Polarizing Plate Sample 22 (Comparative Sample) >> Protective Film Sample for Polarizing Plate Sample 2 except that polyvinyl alcohol was removed from the upper layer liquid (2) used for preparing the protective film sample for polarizing plate 2. In the same manner as in the preparation of the above, a protective film sample for polarizing plate 22 was prepared.

<< Preparation of Protective Film Sample for Polarizing Plate Sample 23 (Comparative Sample) >> Protective Film Sample for Polarizing Plate Sample 3 except that polyvinyl alcohol was removed from the upper layer liquid (3) used for preparing the protective film sample for polarizing plate 3. In the same manner as in the preparation of the above, a protective film sample for polarizing plate 23 was prepared.

<< Preparation of Protective Film Sample for Polarizing Plate 24 (Comparative Sample) >> Protective film sample for polarizing plate sample 6 was prepared except that polyvinyl alcohol was removed from the upper layer liquid (4) used for preparing protective film sample for polarizing plate 6. In the same manner as in the preparation of the above, a protective film sample for polarizing plate 24 was prepared.

<< Preparation of Polarizing Plate Protective Film Sample 25 (Comparative Sample) >> The TAC film was immersed in an 8% by mass aqueous sodium hydroxide solution at 60 ° C. for 2 minutes, washed with running water for 2 minutes, dried and saponified. A treated polarizing plate protective film sample 25 was prepared.

<< Preparation of Protective Film Sample for Polarizing Plate 26 (Comparative Sample) >> Protective Film Sample for Polarizing Plate Sample 5 except that polyvinyl alcohol was removed from the upper layer liquid (1) used for preparing the protective film sample for polarizing plate 5. In the same manner as in the preparation of the above, a protective film sample for polarizing plate 26 was prepared.

<< Preparation of Polarizing Plate Protective Film Sample 27 (Comparative Sample) >> Polarization was performed except that the conductive material (IP-11) was removed from the upper layer liquid (1) used for preparing the polarizing plate protective film sample 7. A polarizing plate protective film sample 27 was prepared in the same manner as in the production of the plate protective film sample 7.

Various characteristics of each of the protective film samples for a polarizing plate obtained as described above were evaluated by the evaluation methods described below.

<< Adhesive Property (Initial Adhesion, Processability, Durability) Between Protective Film for Polarizing Plate and Polarizer >> A polarizing plate was prepared by laminating a polarizer and a protective film in the following steps.

(1) A protective film sample having a size of 18 cm × 5 cm is placed on a glass plate with the coated side up.

(2) Immerse a polarizer composed of a uniaxially stretched polyvinyl alcohol dyed film of the same size as the protective film sample in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds (both sides of the polarizer) do.

(3) The excess adhesive adhering to the polarizer was gently removed, placed on the above protective film sample, and then placed in such a manner that the coated surface of the same sample film and the adhesive were in contact with each other. Are laminated and arranged.

(4) Excessive adhesive and air bubbles are removed from the end of the laminate of the polarizer and the protective film laminated as described above with a hand roller, and they are bonded together. The pressure of the hand roller is about 0.2 to 0.3 MPa, and the roller speed is about 2 m /
Minutes.

(5) The sample is left in a dryer at 80 ° C. for 2 minutes. The adhesiveness (initial adhesiveness, processability, and durability) between the polarizer and the polarizing plate protective film was evaluated for the polarizing film thus produced in the following manner.

After bonding the polarizer and the protective film, the peelability was measured by hand, and the degree of material destruction was evaluated according to the following three grades.

<< Adhesiveness: Initial Adhesion >> After the protective film for a polarizing plate and the polarizer were bonded together, the peelability was measured by hand, and the following three grades were evaluated based on the degree of occurrence of material destruction.

：: The more the material is broken, the better the adhesion between the polarizing plate protective film and the polarizer. ：: The material is partially broken, but the area of peeling between the polarizing plate protective film and the polarizer is large. Peeling between the protective film for polarizing plate and the polarizer << Adhesiveness: Workability >> The sheet was cut using a single blade, and the following three grades were evaluated based on the degree of floating of the adhesive surface.

：: There is no lifting of the bonding surface. Δ: There is a slight lifting of the bonding surface. ×: There is floating of the bonding surface. << Adhesiveness: Durability >> Condition (A) 75 ° C., relative humidity 90
% Condition and condition (B) 90 ° C., relative humidity 10%
Under each of the following conditions, each polarizing plate was left for 500 hours, the appearance change was observed, and the width of peeling from the edge was measured. The ranking of the evaluation is as follows.

：: 0.5 mm or less Δ: 0.6 to 1.5 mm ×: 1.6 mm or more Electrostatic properties of the polarizing plate protective film sample, and then the polarizing plate protective film sample and the polarizer were bonded together. The characteristics of the produced polarizing plate were evaluated as follows.

<< Surface Resistivity >> Each of protective film samples 1 to 27 for a polarizing plate was treated at 23 ° C. and 55% RH for 24 hours.
The humidity was adjusted for a time, and the measurement was performed using a Teraohmmeter model VE-30 manufactured by Kawaguchi Electric Co., Ltd. The electrodes used for the measurement were two electrodes (the part in contact with the sample was 1 cm x 5 c
m) were arranged in parallel at an interval of 1 cm, a sample was brought into contact with the electrode, and the measurement was performed. The value obtained by doubling the measured value was defined as the surface resistivity Ω / cm ² . In the present invention, the surface resistivity indicates a value on the surface of the conductive layer.

<< Measurement of Charge Amount after Peeling of Protective Film, Dust Adhesion Test, Abnormal Display of Liquid Crystal >> Each of the polarizers has a conductive layer having an easy adhesion function of protective film samples 1 to 27 for polarizing plate. In the polarizing plate produced by bonding the surfaces on the sides, polyethylene /
A surface protective film (also referred to as a protective film) made of an ethylene / vinyl acetate copolymer two-layer extruded film is attached, and on the other surface, an acrylic pressure-sensitive adhesive layer having a thickness of 20 μm is provided. It was covered and protected with a separate film composed of a polyester film treated with a silicone release agent.

The obtained sample was subjected to a charge amount test, a dust adhesion test, and a liquid crystal abnormal display test as described below.

<< Measurement of Charge Amount after Peeling of Protect Film >> The protect film of each sample described above was quickly peeled off, and the amount of charge generated on the surface of the resin film of the polarizing plate at the time of peeling was measured by using a charge-type potential meter (product Name: KS-471
(Manufactured by Kasuga Electric Co., Ltd.) under the conditions of 25 ° C. and 20% RH.

<< Test of Abnormal Display of Liquid Crystal >> Each of the above-described samples was incorporated into a liquid crystal panel to produce a printed image, and then an abnormal display of the liquid crystal (image or blurred characters) after peeling off the protective film was removed. Observed visually. If the charge amount after peeling off the protect described above is large, abnormal display of the liquid crystal often occurs.

<< Dust Adhesion Amount >> The adhesion amount of dust on the surface of the acrylic pressure-sensitive adhesive layer of the polarizing plate after the separation film of each sample described above was rapidly peeled off was evaluated as follows.

The dried tobacco ash was put into a glass Petri dish, and the surface of the acrylic adhesive layer was brought close to the height of 1 cm for 10 seconds with the tobacco ash, and adhesion of dust was observed.

・ ・ ・: No dust adhesion was observed at all △: Dust adhesion was slightly observed ×: Dust adhesion was remarkably observed For the polarizing plate of the present invention obtained above Protective film samples 1 to 16, Comparative protective film samples for polarizing plate 17 to 2
7 was used to prepare a polarizing plate, and the yield of the polarizing plate was determined as follows.

<< Polarization Plate Yield >>
The ratio of the area of the polarizing plate having no defective part to the area (length × width) of the polarizing plate protective film used is expressed as a percentage.
In the present invention, the expression "no defective portion" means a polarizing plate having no adhesion of dust and abnormal display of liquid crystal as described above.

Tables 1, 2, and 3 show the obtained results.

[0169]

[Table 1]

[0170]

[Table 2]

[0171]

[Table 3]

Tables 1, 2 and 3 show that the protective film sample for a polarizing plate of the present invention has extremely good adhesion to a polarizer (initial adhesion, workability, durability) and a liquid crystal panel. The polarizer is built into the device, and the amount of charge after peeling off the protective film is small, so there is no abnormal display of the liquid crystal (meaning that images and characters are blurred), and a polarizer with no defective parts can be obtained in high yield. It can be seen that it can be obtained.

[0173]

Industrial Applicability According to the present invention, a protective film for a polarizing plate having excellent antistatic ability and good adhesion to a PVA polarizer film, and a polarizing plate free from abnormal liquid crystal display by using the same. Could be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H049 BA02 BB22 BB33 BB67 2H091 FA08X FA08Z FB02 FD06 GA16 GA17 LA07 LA30 4F100 AA17B AA17C AA18B AA18H AA19B AA19H AAJB AA19AJB AA19AJB AA19BJ AK01D AK21B AK24B AK25A AK41A AK45A AR00B BA02 BA03 BA04 BA07 BA10A BA10C BA10D BA13 CA02B CA02C DE01B GB90 JB05B JB05D JG01B JG01C JG04B JL11B JN01A YY00A YY00B

Claims (15)

[Claims] 1. A protective film for a polarizing plate having a conductive layer containing a conductive material on a resin film, wherein the surface specific resistance of the conductive layer is 10 ¹¹ Ω / cm (23 ° C., 55
% RH) or less, and the conductive layer has an easy adhesion function. 2. The conductive layer comprises a layer (1) containing at least one hydrophilic polymer compound (a) or a layer (2) containing at least one gelatin or gelatin derivative and a cellulose ester. The protective film for a polarizing plate according to claim 1, wherein a conductive material is contained in the layer (1) or the layer (2). 3. A layer containing a -COOM group-containing polymer compound represented by the following general formula [1] or [2], a hydrophilic polymer compound (a), gelatin or a gelatin derivative on at least one surface of a resin film. The protective film for a polarizing plate according to claim 1, comprising: Embedded image [In the formula, A represents a repeating unit formed by polymerization of a vinyl monomer, B represents a hydrogen atom, -CO-OM or -CO-R, M represents a hydrogen atom or a cation, and when z = 0, , B are hydrogen atoms. R is -OR 'or -N
(R ′) (R ″), wherein R ′ represents an alkyl group, an aralkyl group, an aryl group, a heterocyclic residue or a nonmetal atom necessary for forming a heterocyclic ring in cooperation with R ″. R "
Represents a hydrogen atom, a lower alkyl group or a nonmetal atom necessary for forming a heterocyclic ring together with R ′, R ₁ and R ₂ each represent a hydrogen atom or a lower alkyl group, and X represents —C
Represents O—O— or —O—CO—, R ₃ represents a halogen-substituted alkyl group or a halogen-substituted alkyloxyalkyl group, and m, p, q, r, x, y, and z represent each monomer Where m and x are each 0
-60, p, q, r, x, y and z are each 0-100.
M + p + q + r = 100, x + y + z = 100
It is. ] 4. The protective film for a polarizing plate according to claim 2, wherein the hydrophilic polymer compound (a) is a polyvinyl alcohol derivative, a hydrophilic cellulose derivative or a natural polymer. 5. The protective film for a polarizing plate according to claim 1, wherein the conductive material contains an ionic polymer compound as a main component. 6. The conductive material is Sn, Ti, In, Al,
It is a metal oxide containing, as a main component, an element selected from the group consisting of Zn, Si, Mg, Ba, Mo, W and V, and having a volume resistivity of 10 ⁷ Ω · cm or less. The protective film for a polarizing plate according to any one of claims 1 to 5. 7. The metal oxide has a primary particle size of 0.2 μm.
The protective film for a polarizing plate according to claim 6, wherein m is not more than m. 8. The protective film for a polarizing plate according to claim 1, wherein the conductive layer contains fine particles having an average particle size of 5.0 μm or less. 9. The method according to claim 1, further comprising a curling prevention layer on the other side of the surface having the conductive layer on the resin film, wherein the curling prevention layer comprises a composition containing a solvent. Item 10. The protective film for a polarizing plate according to any one of Items 1 to 8. 10. The protective film for a polarizing plate according to claim 2, wherein the layer (1) or the layer (2) contains a crosslinking agent. 11. A layer containing at least one hydrophilic polymer compound (a) or at least one kind of gelatin or a gelatin derivative and a cellulose ester on the other side of the side having a conductive layer on a resin film. The protective film for a polarizing plate according to any one of claims 1 to 10, further comprising a layer containing: 12. The hydrophilic polymer compound (a) is a polyvinyl alcohol derivative, a hydrophilic cellulose derivative or a natural polymer, and the cellulose ester is cellulose triacetate, cellulose diacetate, cellulose acetate propionate or cellulose acetate butyrate. The protective film for a polarizing plate according to claim 2, wherein the rate is a rate. 13. The method according to claim 1, wherein the resin film is a cellulose ester film, a polycarbonate film, a polyester film or a polyacrylate film, and the resin film has a light transmittance of 85% or more. The protective film for a polarizing plate according to claim 1. 14. The protective film for a polarizing plate according to claim 1, wherein the resin film contains a cellulose ester. 15. A polarizing plate comprising the protective film for a polarizing plate according to claim 1. Description: