KR20150061591A - Polarizing plate protective film, method of producing polarizing plate protective film, polarizing plate, and image display device - Google Patents

Abstract

Provided are a polarizing plate protective film which is formed by laminating, on a support, at least two layers made of low moisture permeability layer and urethane acrylate and is excellent in interlayer adhesion and tolerance to lack of uniformity caused by wind, polarizing plate, and an image display device. For example, the polarizing plate protective film comprises: a first functional layer formed of a fluoroaliphatic group-containing co-polymer represented by the following (a) and a composition containing the following A-DCP on the support; and a second functional layer formed of composition containing urethane acrylate to be in contact with the first functional layer. The content of (a) is 0.005-1wt% for the total solids of the composition for forming the first functional layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a polarizing plate protective film, a polarizing plate protective film, a polarizing plate protective film, a polarizing plate protective film,

The present invention relates to a polarizing plate protective film having at least two functional layers and having good interlayer adhesion and wind unevenness resistance, a polarizing plate protective film producing method, a polarizing plate using the polarizing plate protective film, And an image display apparatus.

In recent years, liquid crystal displays have been widely used for liquid crystal televisions, liquid crystal panels for personal computers, mobile phones, digital cameras, and the like. In general, a liquid crystal display device has a liquid crystal panel member provided with polarizing plates on both sides of a liquid crystal cell, and display is performed by controlling light from the backlighting member with a liquid crystal panel member. Here, the polarizing plate comprises a polarizer and its protective film, and general polarizers are obtained by staining a stretched polyvinyl alcohol (PVA) -based film with iodine or a dichroic dye. As the protective film, a cellulose ester film And so on.

The recent liquid crystal display devices are diversified in use with high quality, and the demand for durability has become strict. For example, for use in outdoor applications, stability against environmental changes is required, and optical films such as polarizing plate protective films and optical compensation films used in liquid crystal display devices are also required to have a dimensional or optical characteristic It is required to suppress the change of the temperature.

Patent Document 1 discloses a low moisture permeable film having a cured layer (low moisture permeable layer) obtained by applying and curing a curable composition containing a compound having a specific cyclic aliphatic hydrocarbon group and having two unsaturated double bond groups in a molecule on a transparent substrate film .

On the other hand, it has been known that a layer formed using a composition containing urethane acrylate is excellent in hardness and brittleness (flexibility), and urethane acrylate is widely used to make both hardness and brittleness at a high level (Patent Document 2) .

In film formation by a coating method using a solvent, in order to reduce unevenness due to drying caused by the difference in solvent drying speed and surface unevenness such as non-uniformity caused by wind, which is caused by dry wind, It is known to add agents. Further, when the fluoric leveling agent is eluted into the organic solvent contained in the coating liquid of the layer to be superposed on the layer to which the leveling agent is added, the fluoric leveling agent present at the interface is reduced and the abrasion resistance (Patent Document 3).

Japanese Laid-Open Patent Publication No. 2006-083225 Japanese Patent Application Laid-Open No. 7-333404 Japanese Laid-Open Patent Publication No. 2006-227353

However, when the fluorine leveling agent of Patent Document 3 is added to the cured layer of the low moisture permeable film of Patent Document 1 and a layer composed of urethane acrylate is laminated on the layer, if the fluorine leveling agent is eluted into the layer comprising urethane acrylate , It has become clear that a sufficient adhesion between the cured layer and the urethane acrylate layer may not be obtained.

An object of the present invention is to provide a polarizing plate protective film excellent in interlaminar adhesion and wind non-uniformity resistance as a laminated film of at least two layers of a low moisture permeable layer and a urethane acrylate layer on a support.

Another object of the present invention is to provide a polarizing plate using the polarizing plate protective film and a liquid crystal display using the polarizing plate.

As a result of intensive investigations by the present inventors, it has been found that a composition comprising a first functional layer (low moisture-permeable layer) formed using a compound having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated double bond group and a composition containing urethane acrylate thereon And a fluoroaliphatic group-containing copolymer having a specific structure in the first functional layer is used in a specific amount to find a polarizing plate protective film excellent in interlaminar adhesion and wind unevenness resistance, The present invention has been completed. Such a polarizing plate protective film can be preferably used as a material for an image display apparatus.

The problems to be solved by the present invention can be solved by the present invention which is the following means.

[One]

A support, a first functional layer, and a second functional layer in this order,

The first functional layer and the second functional layer being in contact with each other,

Wherein the first functional layer is a layer formed by using a composition for forming a first functional layer containing the following (A) and (B)

The content of the following component (A) in the composition for forming a first functional layer is 0.005 mass% or more and 1 mass% or less based on the total solid content in the composition for forming a first functional layer,

Wherein the second functional layer is a layer formed using a composition containing urethane acrylate.

(A) at least one kind of repeating unit derived from a fluoroaliphatic group-containing monomer represented by the following general formula (1) and at least one kind of a repeating unit derived from a monomer represented by the following general formula (2) A fluoroaliphatic group-containing copolymer having a mass ratio of a repeating unit derived from a monomer represented by the following general formula (1) to a repeating unit derived from a monomer represented by the following general formula (2) is from 99: 1 to 50:50

[Chemical Formula 1]

(In the general formula (1), R ⁰ represents a hydrogen atom, a halogen atom or a methyl group, L represents a divalent linking group, and q represents an integer of 1 or more and 18 or less)

(2)

(In the general formula (2), R ¹ represents a hydrogen atom, a halogen atom or a methyl group, L ⁴ represents a divalent linking group containing either an oxygen atom, a nitrogen atom or a sulfur atom, or a single bond, Y is _{-OH, -COOH, -SO 3 H,} -PO (OH) 2, -OPO (OH) 2, and - represents a group selected from _{(C 2 H 4 O) mH} m represents an integer of 1 or more)

(B) a curing compound for a binder having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated double bond group

[2]

The polarizing plate protective film according to [1], wherein the composition for forming a first functional layer further contains a rosin-based compound.

[3]

The polarizing plate protective film according to [1] or [2], wherein L in the general formula (1) is -COO- (R ² ) -. Provided that R ² represents an alkylene group having 1 to 8 carbon atoms.

[4]

The polarizing plate protective film according to any one of [1] to [3], wherein L ⁴ in the general formula (2) is a single bond and Y is -COOH.

[5]

The polarizing plate protective film according to any one of [1] to [4], wherein the film thickness of the first functional layer is 3 탆 or more and 25 탆 or less.

[6]

The polarizing plate protective film according to any one of [1] to [5], wherein the film thickness of the second functional layer is 2 탆 or more and 7 탆 or less.

[7]

The polarizing plate protective film according to any one of [1] to [6], wherein the support has a film thickness of 20 mu m or more and 70 mu m or less.

[8]

The method for producing a polarizing plate protective film according to any one of [1] to [7], wherein the first functional layer and the second functional layer are formed on the support so that the first functional layer and the second functional layer are in contact with each other.

[9]

A polarizer comprising the polarizer protective film according to any one of [1] to [7], which is formed as a protective film on at least one surface of the polarizer.

[10]

A polarizer comprising a polarizer, a polarizer protective film according to any one of [1] to [7], which is formed as a protective film on one surface of the polarizer, and an optically anisotropic film formed on the other surface of the polarizer.

[11]

A liquid crystal display device comprising: a liquid crystal cell; and a polarizing plate described in [9] or [10] arranged on at least one side of the liquid crystal cell, wherein the polarizing plate protective film is disposed on an image display surface.

According to the present invention, it is possible to provide a polarizing plate protective film which can improve interlaminar adhesion and is excellent in wind unevenness resistance as a laminated film of at least two layers of a layer comprising a low moisture permeable layer and a urethane acrylate layer. The polarizer and the polarizing plate using the polarizing plate protective film can be preferably used for an image display apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments related to the polarizing plate protective film, the polarizing plate and the image display apparatus of the present invention will be described in detail. The description of constituent elements described below may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a description such as "(numerical value 1) to (numerical value 2)" means "(numerical value 1) or more (numerical value 2) or less" when the numerical value indicates a physical property value or a characteristic value.

The polarizing plate protective film of the present invention comprises a support, a first functional layer, and a second functional layer in this order,

The first functional layer and the second functional layer are in contact with each other,

Wherein the first functional layer is a layer formed by using a composition for forming a first functional layer containing (A) and (B)

The content of the following component (A) in the composition for forming the first functional layer is 0.005 mass% or more and 1 mass% or less based on the total solid content in the composition for forming the first functional layer,

And the second functional layer is a layer formed by using a composition containing urethane acrylate.

(A) at least one kind of repeating unit derived from a fluoroaliphatic group-containing monomer represented by the following general formula (1) and at least one kind of a repeating unit derived from a monomer represented by the following general formula (2) (A) a fluoroaliphatic group-containing copolymer having a mass ratio of a repeating unit derived from a monomer represented by the following general formula (1) to a repeating unit derived from a monomer represented by the following general formula (2) is from 99: 1 to 50:50 A) fluoroaliphatic group-containing copolymer)

(3)

(In the general formula (1), R ⁰ represents a hydrogen atom, a halogen atom or a methyl group, L represents a divalent linking group, and q represents an integer of 1 or more and 18 or less)

[Chemical Formula 4]

(In the general formula (2), R ¹ represents a hydrogen atom, a halogen atom or a methyl group, L ⁴ represents a divalent linking group containing either an oxygen atom, a nitrogen atom or a sulfur atom, or a single bond, Y is _{-OH, -COOH, -SO 3 H,} -PO (OH) 2, -OPO (OH) 2, and - represents a group selected from _{(C 2 H 4 O) mH} m represents an integer of 1 or more)

(B) a curing compound for a binder having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated double bond group (also referred to as a curable compound (B) for a binder)

The components of each functional layer will be described in detail below.

[First functional layer]

The first functional layer is a layer formed by using a composition for forming a first functional layer containing a fluoroaliphatic group-containing copolymer (A) and a curing compound for a binder (B): The content of the following (A) in the composition is from 0.005 mass% to 1 mass% with respect to the total solid content in the composition for forming a first functional layer.

The first functional layer may be formed by applying a composition for forming a first functional layer containing the following copolymer (A) fluoroaliphatic group-containing copolymer on the support and the curable compound for binder (B) Followed by drying and curing.

[(A) Fluoro Aliphatic Group-Containing Copolymer]

In the present invention, the fluoroaliphatic group-containing copolymer (A) (hereinafter, also referred to as a fluorine-based leveling agent) in the present invention is a copolymer comprising at least one kind of a repeating unit derived from a fluoroaliphatic group-containing monomer represented by the following general formula (1) 1. A polymer comprising a repeating unit derived from a monomer represented by the following general formula (1) and at least one repeating unit derived from a monomer represented by the following general formula (2) Is a fluoroaliphatic group-containing copolymer having a mass ratio of repeating units of from 99: 1 to 50:50.

[Chemical Formula 5]

(In the general formula (1), R ⁰ represents a hydrogen atom, a halogen atom or a methyl group, L represents a divalent linking group, and q represents an integer of 1 or more and 18 or less)

[Chemical Formula 6]

(In the general formula (2), R ¹ represents a hydrogen atom, a halogen atom or a methyl group, L ⁴ represents a divalent linking group containing either an oxygen atom, a nitrogen atom or a sulfur atom, or a single bond, Y is _{-OH, -COOH, -SO 3 H,} -PO (OH) 2, -OPO (OH) 2, and - represents a group selected from _{(C 2 H 4 O) mH} m represents an integer of 1 or more)

The fluoroaliphatic group-containing copolymer (A) has a function of smoothing the surface of the first functional layer and preventing the unevenness due to wind, and also has a hydrophilic group (Y) of the general formula (2) The adhesion between the first functional layer and the second functional layer can be improved by the interaction of the urethane acrylate contained in the second functional layer.

First, the fluoroaliphatic group-containing monomer represented by the general formula (1) will be described in detail.

In the general formula (1), R ⁰ represents a hydrogen atom, a halogen atom or a methyl group, preferably a hydrogen atom, a fluorine atom or a methyl group, more preferably a hydrogen atom or a methyl group. L represents a divalent linking group and is preferably a divalent linking group containing an oxygen atom, a sulfur atom or a nitrogen atom, and is preferably -COO-, -COO (R ² ) -, -COS-, -COS (R ² ) , -CON (R ³ ) -, and -CON (R ³ ) (R ² ) -, and most preferably -COO (R ² ) -. R ² represents an alkylene group having 1 to 8 carbon atoms, and R ³ represents an alkyl group having 1 to 8 carbon atoms which may have a hydrogen atom or an aryl group as a substituent. R ² is preferably an alkylene group having 1 to 6 carbon atoms and more preferably an alkylene group having 1 to 3 carbon atoms. R ³ is preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. q represents an integer of 1 or more and 18 or less, more preferably 4 to 12, still more preferably 6 to 8, and most preferably 6.

The fluoroaliphatic group-containing copolymer (A) may contain two or more repeating units derived from a monomer containing a fluoroaliphatic group represented by the general formula (1).

Specific examples of the fluoroaliphatic group-containing monomer represented by the general formula (1) are shown below, but the present invention is not limited thereto.

(7)

[Chemical Formula 8]

[Chemical Formula 9]

[Chemical formula 10]

Next, the repeating unit derived from the monomer represented by the general formula (2) will be described. The formula (2) does not contain a fluoroaliphatic group. In the general formula (2), R ¹ represents a hydrogen atom, a halogen atom or a methyl group, preferably a hydrogen atom or a methyl group. L ⁴ represents a divalent linking group containing either an oxygen atom, a nitrogen atom, or a sulfur atom, or a single bond. If the L ⁴ represents a divalent connecting group is ^{-COO-, -COO (R 5) -} , -COS-, -COS (R 5) -, -CON (R 6) -, -CON (R 6) (R ⁵ ) -. R ⁵ represents an alkylene group having 1 to 8 carbon atoms and R ⁶ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ⁵ is preferably an alkylene group having 1 to 6 carbon atoms and more preferably an alkylene group having 1 to 3 carbon atoms. Y is _{-OH, -COOH, -SO 3 H,} -PO (OH) 2, -OPO (OH) 2, and - represents a group selected from _{(C 2 H 4 O) mH} . m represents an integer of 1 or more.

It is most preferable that L ⁴ is a single bond and Y is -COOH.

Specific examples of the monomer represented by the general formula (2) are shown below, but the present invention is not limited thereto.

(11)

[Chemical Formula 12]

The fluoroaliphatic group-containing copolymer (A) has an effect of preventing occurrence of unevenness due to wind. The weight average molecular weight of the (A) fluoroaliphatic group-containing copolymer is preferably from 5,000 to 50,000, more preferably from 8,000 to 30,000, and still more preferably from 10,000 to 20,000. When the weight average molecular weight is 5000 or more, the ability to prevent wind unevenness is sufficient, and when the weight average molecular weight is 50000 or less, the solubility and dissolving ability of the organic solvent is improved.

Here, the weight average molecular weight was measured using TSKgel GMH _XL , TSKgel G4000H _XL , TSKgel G2000H _XL (Tetrahydrofuran) by a GPC analyzer using a column of " Triton " (trade name of all manufactured by Tosoh Corporation) and a molecular weight expressed in terms of polystyrene by differential refractometer detection.

The mass ratio of the repeating unit derived from the monomer represented by the general formula (1) and the repeating unit derived from the monomer represented by the general formula (2) constituting the fluoroaliphatic group-containing copolymer (A) is from 99: 1 to 50: 50 , Preferably 97: 3 to 60:40, and more preferably 95: 5 to 70: 30.

The content of the fluoroaliphatic group-containing copolymer (A) is preferably 0.005 mass% or more and 1 mass% or less, more preferably 0.01 mass% or more and 0.5 mass% or less based on the total solid content in the composition for forming a first functional layer, And more preferably 0.05 mass% or more and 0.3 mass% or less. The addition amount of the fluoroaliphatic group-containing copolymer (A) relative to the total solid content in the composition for forming the first functional layer is not less than 0.005% by mass, thereby preventing unevenness due to wind. In addition, when the content is 1% by mass or less, sicching can be suppressed and deterioration in the surface can be prevented.

[(B) Curable compound for binder]

The curable compound (B) for a binder contained in the composition for forming a first functional layer of the present invention is a curable compound for a binder having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated double bond group.

By using a compound having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated double bond group, low moisture permeability can be realized, and adhesion to a support or other layer is excellent and light leakage of the polarizing plate can be prevented. Although details are not clear, by using a compound having a cyclic aliphatic hydrocarbon group in the molecule, a hydrophobic cyclic aliphatic hydrocarbon group is introduced into the first functional layer and hydrophobized to prevent mixing of water molecules from the outside to lower the moisture permeability . Further, by having an ethylenically unsaturated double bond group in the molecule, the cross-linking point density is increased to restrict the diffusion path of water molecules in the first functional layer. Increasing the crosslinking point density also has an effect of relatively increasing the density of the cyclic aliphatic hydrocarbon group, which makes it possible to prevent the adsorption of water molecules by making the inside of the first functional layer more hydrophobic, thereby lowering the moisture permeability.

The number of ethylenically unsaturated double bond groups in the molecule for increasing the cross-linking density is more preferably 2 or more.

The cyclic aliphatic hydrocarbon group is preferably a group derived from an alicyclic compound having 7 or more carbon atoms, more preferably a group derived from an alicyclic compound having 10 or more carbon atoms, more preferably derived from an alicyclic compound having 12 or more carbon atoms .

The cyclic aliphatic hydrocarbon group is particularly preferably a group derived from a polycyclic compound such as bicyclic or tricyclic.

More preferably, the central skeleton of the compound represented by the general formulas (A) and (B) in Japanese Patent Laid-Open Publication No. 2006-215096, the central skeleton of the compound described in Japanese Patent Application Laid-Open No. 2001-10999, And a skeleton.

Specific examples of the cyclic aliphatic hydrocarbon group include a norbornane group, a tricyclodecane group, a tetracyclododecane group, a pentacyclopentadecane group, an adamantane group, and a diamantane group.

The cyclic aliphatic hydrocarbon group (including a linking group) is preferably a group represented by any one of the following general formulas (I) to (V), more preferably a group represented by the following general formula (I), (II) , And a group represented by the following general formula (I) is more preferable.

[Chemical Formula 13]

In the general formula (I), L ₁ and L ₂ each independently represent a single bond or a divalent or higher linking group. and n represents an integer of 1 to 3.

[Chemical Formula 14]

In formula (II), L ₁ and L ₂ each independently represent a single bond or a divalent or higher linking group. and n represents an integer of 1 to 2.

[Chemical Formula 15]

In the general formula (III), L ₁ and L ₂ each independently represent a single bond or a divalent or higher linking group. and n represents an integer of 1 to 2.

[Chemical Formula 16]

In formula (IV), L ₁ and L ₂ each independently represent a single bond or a divalent or higher linking group, and L ₃ represents a hydrogen atom, a single bond or a divalent or higher linking group.

[Chemical Formula 17]

In the general formula (V), L ₁ and L ₂ each independently represent a single bond or a divalent or higher linking group.

Examples of the divalent linking group for L ₁ , L ₂ and L ₃ include an optionally substituted alkylene group having 1 to 6 carbon atoms, an amide bond which may be substituted at the N position, a urethane bond which may be substituted at the N position, A bond, an oxycarbonyl group, an ether bond and the like, and a group obtained by combining two or more of them.

Examples of the ethylenically unsaturated double bond group include polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group and an allyl group, and among them, a (meth) acryloyl group and -C (O) OCH = CH ₂ is preferable. More preferably two or more (meth) acryloyl groups in one molecule, and more preferably three or more (meth) acryloyl groups in one molecule.

The compound having a cyclic aliphatic hydrocarbon group and having two or more ethylenically unsaturated double bond groups in the molecule is constituted by bonding the group having the cyclic aliphatic hydrocarbon group and the group having an ethylenically unsaturated double bond group via a linking group.

These compounds can be obtained, for example, by reacting a polyol such as a diol or triol having the cyclic aliphatic hydrocarbon group with a carboxylic acid of a compound having a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, Can be easily synthesized by one or two-step reaction such as a derivative, an epoxy derivative, and an isocyanate derivative.

Preferred examples thereof include compounds such as (meth) acrylic acid, (meth) acryloyl chloride, (meth) acrylic acid anhydride and glycidyl (meth) acrylate, compounds described in WO2012 / 00316A (Acryloxymethyl) ethyl isocyanate), with a polyol having the cyclic aliphatic hydrocarbon group.

Hereinafter, preferable exemplary compounds M-1 to M-8 of the compound having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated double bond group are shown, but the present invention is not limited thereto.

[Chemical Formula 18]

[Chemical Formula 19]

[Chemical Formula 20]

The content of the curable compound for the binder (B) is preferably 50% by mass or more and less than 99.995% by mass, more preferably 60% by mass or more and 99.995% by mass based on the total solid content in the composition for forming a first functional layer from the viewpoint of obtaining sufficient curability %, More preferably 70 mass% or more and less than 99.995 mass%.

In the composition for forming the first functional layer of the present invention, a rosin compound, a polymerization initiator, a solvent, an inorganic layer compound and an ultraviolet absorber may be further added, if necessary. Hereinafter, each component will be described.

[Rosin compound]

In the present invention, it is also preferable that the first functional layer contains a rosin-based compound. By containing the rosin-based compound, the moisture permeability can be further reduced.

The rosin-based compound is preferably at least one selected from rosin, acid-modified rosin and esterified rosin (also referred to as rosin ester).

Examples of the rosin include tall oil rosin, gum rosin, wood rosin, etc., which are mainly composed of resin acid such as abietic acid, levopimaric acid, palustric acid, neoabietic acid, dehydroabietic acid or dihydroabietic acid Of unmodified rosins.

Examples of the rosin esters include super ester E-720, super ester E-730-55, super ester E-650, super ester E-786-60, Tamanol E-100, emulsion AM-1002, Super ester A-18, Super ester A-75, Super ester A-100, Super ester A-115, Super ester A- 125, super ester T-125 (all trade names, special rosin ester, manufactured by Arakawa Chemical Industries Co., Ltd.).

Examples of the rosin esters include esters AAG, ester gum AAL, ester gum A, ester gum AAV, ester gum 105, ester gum HS, ester gum AT, ester gum H, ester gum HP, ester gum HD, , PENCEL AZ, PENSEL C, PENCEL D-125, PENCEL D-135, PENCEL D-160, PENCEL KK (all trade names, rosin ester resin, manufactured by Arakawa Chemical Industry Co., Ltd.).

Examples of other rosins include RONDIS R, LONDIS K-25, LONDIS K-80 and LONDIS K-18 (all trade names, rosin derivatives, Arakawa Chemical Industries Ltd.) Fine Crystal KR-120, Fine Crystal KR-612, Fine Crystal KR-614, Fine Crystal KE-100, Fine Crystal KE-311, Fine Crystal KE-359, Fine Crystal KE-604, Fine Crystal 30PX, Fine Crystal Pine Crystal KM-1550 (all trade names, both of which are trade names, manufactured by Arakawa Chemical Industries, Ltd.) (All trade names, hydrogenated rosin, manufactured by Arakawa Chemical Industry Co., Ltd.), Ardyr R-140, Arradime R-95 (all trade names, all of which are manufactured by Arakawa Chemical Industries, Set 101 (all trade names, rosin acrylate, manufactured by Arakawa Chemical Industry Co., Ltd.) ), And the like.

The softening point of the rosin compound is preferably 70 to 170 占 폚. When the softening point of the rosin compound is 70 占 폚 or higher, the hardening layer is not softened and the blocking property is excellent. When the softening point is 170 DEG C or less, the solubility in a solvent can be maintained, and the haze of the cured layer is not easily increased.

In the present invention, the softening point of the rosin compound can be measured by the ring method of JIS K-2531.

The content of the rosin compound is preferably from 1 to 40% by mass, more preferably from 5 to 30% by mass, from the viewpoint of the remarkable reduction in the water vapor permeability when the total solid content of the composition for forming the first functional layer is 100% , And more preferably 10 to 25 mass%.

[Polymerization Initiator]

It is preferable that a polymerization initiator is added to the composition for forming the first functional layer. The polymerization initiator is preferably a photopolymerization initiator.

Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphinoxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, An aromatic sulfonium salt, a lophine dimer, an onium salt, a borate salt, an active ester, an active halogen, an inorganic complex, a coumarin, and the like. Specific examples of the photopolymerization initiator, preferable embodiments, and commercially available products are described in paragraphs [0133] to [0151] of JP-A No. 2009-098658, and the same can be similarly used in the present invention.

"Latest UV curing technology" (1991), p.159, and "ultraviolet curing system" Kiyomi Kato (issued by the Technical Center, 1989) p.65 ~ 148 Examples are described and are useful in the present invention.

Commercially available photocatalytic radical photopolymerization initiators include "Irgacure 651", "Irgacure 184", "Irgacure 819", and "Irgacure 819" manufactured by BASF Corporation (formerly Ciba Specialty Chemicals) Irgacure 907 "," Irgacure 1870 "(CGI-403 / Irgacure 184 = 7/3 mixed initiator), Irgacure 500, Irgacure 369, Irgacure 1173, Irgacure 2965 "," Irgacure 4265 "," Irgacure 4263 "," Irgacure 127 "," OXE01 "and the like; "Kaya Cure BP-100", "Kaya Cure BDMK", "Kaya Cure CTX", "Kaya Cure BMS", "Kaya Cure 2-EAQ" manufactured by Nippon Kayaku Co., "Kaya Cure ABQ", "Kaya Cure CPTX", "Kaya Cure EPD", "Kaya Cure ITX", "Kaya Cure QTX", "Kaya Cure BTC", "Kaya Cure MCA" etc .; Esacure (KIP100F, KB1, EB3, BP, X33, KTO46, KT37, KIP150, TZT) "manufactured by Sato MUSA, and the like, and combinations thereof are preferable examples.

The content of the photopolymerization initiator in the composition for forming a first functional layer is preferably from 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of the polymerizable compound Is preferably from 0.5 to 8% by mass, more preferably from 1 to 5% by mass, based on the total solid content in the composition.

[solvent]

The composition for forming the first functional layer may contain a solvent. As the solvent, various solvents may be used in consideration of the solubility of the monomer, the dryness upon coating, the dispersibility of the light-transmitting particles, and the like. Examples of the organic solvent include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, The organic solvent is preferably an organic solvent selected from the group consisting of methanol, ethanol, fumaric, anisole, phenetole, dimethyl carbonate, methyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, Propyl acetate, methyl propionate, methyl propionate, methyl propionate, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, 2- (2-methoxyethoxy) ethyl acetate, Diethoxyacetone, acetyl acetone, diacetone alcohol, methyl acetoacetate, methyl ethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, Ethyl acetoacetate, and the like, ethyl alcohol , Isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol, isobutyl acetate, methyl isobutyl ketone (MiBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, There may be mentioned ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, The species may be used singly or in combination of two or more species.

Among these solvents, at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, acetone, toluene and xylene is preferably used.

The solvent is preferably used so that the solid content concentration in the first functional layer forming composition is in the range of 20 to 80 mass%, more preferably 30 to 75 mass%, and still more preferably 40 to 70 mass%.

[Inorganic layer compound]

In order to reduce the moisture permeability of the first functional layer, it is also preferable to disperse the inorganic layer compound in the composition for forming the first functional layer. Since the inorganic layered compound has a hydrophilic surface, it is preferable to carry out the organizing treatment.

The inorganic layered compound is an inorganic compound having a structure in which unit crystal layers are laminated and exhibiting a property of swelling or cleavage by coordinating or absorbing a solvent between layers. Examples of such inorganic compounds include hydroscopic hydrous silicates such as smectite group clay minerals (montmorillonite, saponite, hectorite and the like), vermiculite group clay minerals, kaolinite group clay minerals and phyllosilicates (such as mica) . The synthetic inorganic layered compound is also preferably used. Examples of the synthetic inorganic layered compound include synthetic smectite (hectorite, saponite, stevensite and the like) and synthetic mica. Smectite, montmorillonite and mica are preferable, and montmorillonite , And mica are more preferable. As the inorganic layered compound that can be used as a commercially available product, MEB-3 (manufactured by Mitsubishi Chemical Corporation, a synthetic mica aqueous dispersion), ME-100 (synthetic mica manufactured by KOKUCHEMICAL CO., LTD.), S1ME Mica), SWN (synthetic smectite manufactured by Kobunshi Kogyo Co., Ltd.), SWF (synthetic smectite manufactured by Kobunshi Kogyo Co., Ltd.), Kunipia F (refined bentonite manufactured by Kunimine Chemical Industry Co., Ltd.) (Purified bentonite manufactured by HONJIN CO., LTD.), BenzelBrite 23 (manufactured by HONJIN CO., LTD.), (Purified bentonite manufactured by HONJIN CO., LTD.), Benzel A (manufactured bentonite manufactured by HONJIN CO., LTD.) And Benzel 2M (manufactured by HONJIN CO., LTD.

It is preferable that these inorganic layered compounds are subjected to an organizing treatment.

Examples of the organic layered compound subjected to the organizing treatment include the organically treated inorganic layered compounds described in JP-A No. 2012-234094, paragraphs 0038 to 0044.

The swellable layered inorganic compound is preferably subjected to a microparticulation treatment in terms of achieving both low moisture permeability and adhesion between the support / first functional layer. The swellable layered inorganic compound subjected to the microparticulation treatment is usually in the form of a plate or a flat, and the plane shape is not particularly limited and may be amorphous. The average particle diameter (average particle diameter of the planar shape) of the swellable layered inorganic compound treated with the microparticles is preferably 0.1 to 10 mu m, more preferably 0.1 to 8 mu m, and particularly preferably 0.1 to 6 mu m.

[UV absorber]

The polarizing plate protective film of the present invention can be used for a polarizing plate or an image display apparatus member. However, from the viewpoint of preventing deterioration of the polarizing plate or the liquid crystal cell, the ultraviolet absorbing agent is contained in the composition for forming the first functional layer, .

As the ultraviolet absorber, any known ultraviolet absorber may be used. For example, the ultraviolet absorber described in Japanese Patent Application Laid-Open No. 2001-72782 or Japanese Patent Application Laid-Open No. 2002-543265 can be mentioned.

As the ultraviolet absorber, it is preferable to use ultraviolet absorbers having an excellent ultraviolet absorbing ability at a wavelength of 370 nm or less and a small amount of visible light having a wavelength of 400 nm or more from the viewpoint of good liquid crystal display properties. The ultraviolet absorber may be used alone or in combination of two or more. For example, the ultraviolet absorber described in Japanese Patent Application Laid-Open No. 2001-72782 or Japanese Patent Application Laid-Open No. 2002-543265 can be mentioned. Specific examples of the ultraviolet absorber include, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic ester compounds, benzophenone compounds, cyanoacrylate compounds, and nickel complex salt compounds.

Among them, preferred are 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole Sol, 2- (2'-hydroxy-3'- (3 ", 4", 5 ", 6" -tetrahydrophthalimidemethyl) -5'-methylphenyl) benzotriazole, 2 , 2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol) butylphenyl) -5-chlorobenzotriazole, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy- (2-methoxy-4-hydroxy-5-benzoylphenylmethane), (2,4-bis- (n-octylthio) -6- (4-hydroxy- Di-tert-butyl anilino) -1,3,5-triazine, 2 (2'-hydroxy-3 ', 5'- , (2 (2'-Hi Butyl-p-cresol, pentaerythrityl-tetrakis [3- (3, 5-di-tert- amylphenyl) -5-chlorobenzotriazole, 2,6- Butyl-5-methyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert- (6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4- 3,5-di-tert-butyl anilino) -1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5- Hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate. Particularly, it is preferable to use (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di- tert -butyl anilino) (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,6-di-tert-butyl-p-cresol, pentaerythrityl- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] is preferable. (2,4-di-tert-butylphenyl) phosphite, or the like, may be used in combination with a metal-free stabilizer such as a hydrazine-based metal deactivator such as 5-di-tert- butyl-4-hydroxyphenyl) propionyl] hydrazine .

[Second Functional Layer]

The second functional layer of the present invention is formed using a composition containing urethane acrylate (also referred to as a composition for forming a second functional layer). The second functional layer can be formed by directly coating, drying and curing a composition containing urethane acrylate as a curable compound on the first functional layer formed on the support.

Urethane acrylate is a compound having an urethane bond and an acrylate. The urethane acrylate is obtained by, for example, reacting an isocyanate with a hydroxyl group-containing compound such as an alcohol, a polyol, and / or an acrylate containing a hydroxyl group, And esterifying the polyurethane compound obtained by these reactions with acrylic acid.

By containing urethane acrylate in the composition for forming the second functional layer, the balance between hardness and brittleness is excellent.

Specific examples of the urethane acrylate include UV-1700B, UV-6300B, UV-7600B, UV-7600B manufactured by Nippon Synthetic Chemical Industry Co., Ltd., UA-306H, UA- UA-100H, U-6LPA, U-15HA, UA-32P and U-324A manufactured by Shin-Nakamura Chemical Co., Ltd., such as UV-7640B, UV-7640B and UV- UN-3220HB, UN-3220HC and UN-3220HS manufactured by Negami Chemical Industry Co., Ltd., but are not limited thereto.

The content of urethane acrylate contained in the composition for forming a second functional layer is preferably contained in a proportion of 20 mass% or more and less than 100 mass% with respect to the total solid content in the composition for forming a second functional layer, Is 50 mass% or more, and more preferably 80 mass% or more.

The urethane acrylate may be used singly or in combination of two or more kinds.

The composition for forming the second functional layer may contain a polymerization initiator, a light-transmitting resin particle, a solvent, an inorganic layer compound, a fine silica particle, an ultraviolet absorber and a solvent, if necessary.

[Transparent resin particle]

The composition for forming the second functional layer of the present invention may contain light-transmitting resin particles (also referred to as light-diffusing particles). By containing translucent particles in the second functional layer forming composition, the surface of the second functional layer can be provided with a concave-convex shape or an internal haze can be imparted.

The average particle diameter of the light transmitting resin particles is 1.0 占 퐉 or more and 3.0 占 퐉 or less, preferably 1.2 占 퐉 or more and 2.8 占 퐉 or less, and more preferably 1.4 占 퐉 or more and 2.6 占 퐉 or less. In the present invention, the average particle diameter indicates the primary particle diameter. When the average particle size is 1.0 占 퐉 or more, the aggregation of the particles is controlled, whereby the surface irregularities of the second functional layer can be appropriately increased, and the retardation is manifested. In the case of forming a desired surface shape with particles having an average particle size of 3.0 m or less, it is not necessary to make the thickness of the second functional layer excessively thick, and curling or brittleness can be suppressed from being lowered.

As means for adjusting the surface irregularity shape to a specific range, it is also preferable to use two or more kinds of particles having different average particle diameters.

As the method of measuring the particle diameter of the light transmitting resin particle, any measurement method can be applied as long as it is a measurement method for measuring the particle diameter of the particles. However, the particle size distribution of the particles is measured by the Coulter counter method, , Or a method of observing particles with a transmission electron microscope (magnification: 500,000 to 2,000,000 times) to observe 100 particles and to average the average particle size.

In the present invention, the average particle diameter is a value obtained by the Coulter counter method.

In order to form the surface irregularities in the second functional layer of the present invention, the ratio of the film thickness of the second functional layer to the average particle diameter of the light transmitting resin particles (the film thickness of the second functional layer / the average particle diameter of the light transmitting resin particles) Is preferably designed to be 1.0 to 2.0, more preferably 1.1 to 1.9, and still more preferably 1.2 to 1.8. When the ratio is 1.0 or more, the unevenness of the film surface does not become excessively large, which is excellent in terms of black clarity and point defects. On the other hand, if it is 2.0 or less, it is not necessary to add a large amount of particles in order to attain desired antiglare property, and it is excellent in view of the hardness of the film.

The arithmetic mean roughness Ra of the surface irregularities of the second functional layer is preferably 0.01 to 0.25 탆, more preferably 0.01 to 0.20 탆, and still more preferably 0.01 to 0.15 탆. When the value of Ra is 0.01 mu m or more, clear diffusibility is obtained, while when the value of Ra is 0.25 mu m or less, high black clarity is exhibited.

The haze value of the second functional layer of the present invention is preferably designed to be 0.5 to 5.0%, more preferably 1.5 to 4.5%, and further preferably 2.5 to 4.0%. By designing the haze in this range, it is possible to combine excellent flash resistance and black sharpness.

The refractive index of the translucent resin particle is adjusted by changing the mixing ratio of two kinds of solvents having different refractive indexes, which are selected from methylene iodide, 1,2-dibromopropane and n-hexane, and the translucent particles are equally dispersed in a solvent whose refractive index is changed The turbidity is measured and the refractive index of the solvent when the turbidity becomes minimum is measured by an Abbe refractometer.

The translucent resin particle can be imparted with the internal scattering property by controlling the difference in refractive index with respect to the binder. However, since the contrast is lowered if the internal scattering property is large, the difference between the refractive index and the refractive index of the antiglare layer excluding the light- The refractive index difference between the light transmitting resin particle and the binder is 0.01 or less, preferably 0.005 or less, and more preferably 0. [ By setting the refractive index difference within this range, it is possible to substantially eliminate the decrease in contrast caused by the internal scattering.

Specific examples of the light transmitting resin particles include, for example, crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles, crosslinked polystyrene particles, crosslinked methyl methacrylate-methyl acrylate copolymer particles, crosslinked acrylate- Styrene copolymer particles, melamine-formaldehyde resin particles, benzoguanamine-formaldehyde resin particles, and the like. Among them, crosslinked styrene particles, crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles and the like are preferable. In addition, surface modified particles obtained by chemically bonding a compound containing a fluorine atom, a silicon atom, a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, a phosphoric acid group or the like to the surface of these resin particles and inorganic fine particles of nano size such as silica or zirconia Examples of the particles are as follows.

The number of the light transmitting resin particles used in the present invention may be one or two or more. The content of the light transmitting resin particle is preferably 0.5 to 12 mass%, more preferably 1 to 10 mass%, and more preferably 2 to 8 mass%, based on the total solid content in the composition for forming a second functional layer, % Is more preferable.

Specific examples and preferable examples of the polymerization initiator, the solvent, the inorganic layered compound, and the ultraviolet absorber which can be added to the composition for forming the second functional layer include the components which can be added to the composition for forming the first functional layer The same as the specific examples and preferred examples.

[Support]

As the support in the present invention, a known transparent resin film, a transparent resin plate, a transparent resin sheet, or the like can be used, and there is no particular limitation. Examples of the transparent resin film include a cellulose acylate film (for example, a cellulose triacetate film (refractive index: 1.48), a cellulose diacetate film, a cellulose acetate butyrate film, a cellulose acetate propionate film), a polyethylene terephthalate film, (Meth) acrylonitrile film, and the like can be used as the resin (A), the polyolefin resin film, the polyurethane resin film, the polyester film, the polycarbonate film, the polysulfone film, the polyether film, the polymethylpentene film, .

Among them, a cellulose acylate film which is high in transparency, low in optical birefringence, easy to manufacture, and generally used as a protective film of a polarizing plate is preferable, and a cellulose triacetate film is more preferable. In addition, the thickness of the support is usually about 20 탆 to 1000 탆. In the present invention, it is particularly preferable that the support is a cellulose ester film and that the film thickness of the cellulose ester film is 20 mu m or more and 70 mu m or less.

The support of the present invention preferably has higher transparency and preferably has a transmittance of visible light of 80% or more.

In the present invention, cellulose acetate having an acetylation degree of 59.0 to 61.5% is preferably used as the cellulose acylate film.

The degree of acetalization refers to the amount of acetic acid bound per unit mass of cellulose. The degree of acetylation is determined according to the measurement and calculation of the degree of acetylation in ASTM: D-817-91 (Test Method such as Cellulose Acetate). The viscosity average degree of polymerization (DP) of the cellulose acylate is preferably 250 or more, more preferably 290 or more.

In the cellulose acylate used in the present invention, the value of Mw / Mn (Mw is the weight average molecular weight and Mn is the number average molecular weight) by gel permeation chromatography is close to 1.0, in other words, the molecular weight distribution is narrow desirable. The specific Mw / Mn value is preferably 1.0 to 1.7, more preferably 1.3 to 1.65, and most preferably 1.4 to 1.6.

Generally, the hydroxyl groups at 2, 3, and 6 of cellulose acylate are not uniformly distributed at 1/3 of the total degree of substitution, and the degree of substitution of 6-position hydroxyl groups tends to be small. In the present invention, the degree of substitution of the 6-position hydroxyl group of the cellulose acylate is preferably larger than that at the 2 and 3 positions. It is preferable that the hydroxyl group at the 6-position is substituted with an acyl group of 32% or more, more preferably 33% or more, particularly preferably 34% or more with respect to the substitution degree of the whole. And the substitution degree of the 6-position acyl group of the cellulose acylate is preferably 0.88 or more. The 6-position hydroxyl group may be substituted with an acyl group having 3 or more carbon atoms, such as a propionyl group, a butyroyl group, a valeroyl group, a benzoyl group, an acryloyl group, etc. in addition to an acetyl group. The degree of substitution at each position can be determined by NMR.

In the present invention, as the cellulose acylate, in paragraphs "0043" to "0044" [Examples] [Synthesis Example 1], paragraphs "0048" to "0049" [Synthesis Example 2], and paragraphs " 0051 "to" 0052 "[Synthesis Example 3] can be used.

In the present invention, the polyethylene terephthalate film is also excellent in transparency, mechanical strength, planarity, chemical resistance and moisture resistance, and is inexpensive and preferably used. In order to further improve the adhesion strength between the transparent plastic film and the hard coat layer formed thereon, it is more preferable that the transparent plastic film is subjected to an easy adhesion treatment. Examples of the PET film on which a commercially available easy-to-adhere optical layer is formed include COSMOSHINE A4100 and A4300 manufactured by Toyo Spinning Yarn.

≪ Layer Composition of Polarizing Plate Protective Film >

In the polarizing plate protective film of the present invention, a first functional layer is formed on a support and a second functional layer is formed directly on the first functional layer. Another layer may be interposed between the support and the first functional layer.

Examples of preferable layer constitution of the polarizing plate protective film of the present invention are shown below, but it is not particularly limited to these layer constitution.

Support / first functional layer / second functional layer

The support / the first functional layer / the second functional layer / the antireflection layer

Support / Adhesive layer / First functional layer / Second functional layer

Support / Adhesive layer / First functional layer / Second functional layer / Antireflection layer

Support / ultraviolet absorbing layer / first functional layer / second functional layer

Support / ultraviolet absorbing layer / first functional layer / second functional layer / antireflection layer

Support / Adhesive layer / Ultraviolet absorbing layer / First functional layer / Second functional layer

Support / Adhesive layer / Ultraviolet absorbing layer / First functional layer / Second functional layer / Antireflection layer

Support / first functional layer / second functional layer / antiglare layer

Support / first functional layer / second functional layer / antiglare layer / antireflection layer

[Film thickness of first functional layer]

The film thickness of the first functional layer of the present invention is preferably 3 mu m or more and 25 mu m or less, more preferably 5 mu m or more and 20 mu m or less, and further preferably 7 mu m or more and 15 mu m or less. By setting the film thickness of the first functional layer to 3 mu m or more, the moisture permeability can be clearly reduced with respect to the support. When the thickness is 25 mu m or less, the deterioration width of the brittleness can be suppressed.

[Film thickness of the second functional layer]

The film thickness of the second functional layer of the present invention is preferably from 2 탆 to 7 탆, more preferably from 2.5 탆 to 6 탆, and further preferably from 3 탆 to 5 탆.

<Functional layer>

The polarizing plate protective film in the present invention may further have another functional layer. The type of the functional layer is not particularly limited, but an antireflection layer (a layer in which a refractive index is adjusted such as a low refractive index layer, a medium refractive index layer and a high refractive index layer), an antiglare layer, an antistatic layer, an ultraviolet absorbing layer, And a layer for improving the adhesion of the functional layer).

The functional layer may be a single layer or a plurality of layers. The method of laminating the functional layers is not particularly limited.

The functional layer may be laminated on the surface on which the first and second functional layers of the present invention are not laminated.

{Antireflection layer}

In the present invention, an antireflection layer may be laminated on the second functional layer. As the antireflection layer, those known in the art can be preferably used, and among them, a UV curable antireflection layer is preferable.

The antireflection layer may be a low-reflectivity layer having a film thickness of? / 4 of one layer constitution or a multilayer structure, but a low-reflectivity layer having a film thickness of? / 4 of one-layer constitution is particularly preferable. The low refractive material which can be preferably used in the present invention is described below, but the present invention is not limited to the following.

[Low Refractive Material of Antireflection Layer]

The low refractive index material of the antireflection layer will be described below.

[Inorganic fine particles]

From the viewpoints of reducing the refractive index and improving the scratch resistance, it is preferable to use the inorganic fine particles for the antireflection layer. The inorganic fine particles are not particularly limited as long as the average particle size is 5 to 120 nm, but inorganic low refractive index particles are preferable from the viewpoint of lowering the refractive index.

As the inorganic fine particles, mention may be made of magnesium fluoride or fine particles of silica in view of low refractive index. Particularly, silica fine particles are preferable in terms of refractive index, dispersion stability, and cost. The size (primary particle size) of these inorganic particles is preferably 5 to 120 nm, more preferably 10 to 100 nm, 20 to 100 nm, and most preferably 30 to 90 nm.

If the particle size of the inorganic fine particles is too small, the effect of improving the scratch resistance is reduced. If the inorganic fine particles are too large, fine irregularities are formed on the surface of the low refractive index layer to deteriorate appearance and integral reflectance such as black clarity. In the case of using hollow silica fine particles to be described later, if the particle diameter is too small, the ratio of the cavity portion is reduced, so that a sufficient reduction in the refractive index can not be expected. The inorganic fine particles may be either crystalline or amorphous, and may be monodisperse particles or aggregated particles provided that they satisfy a predetermined particle size. The shape is most preferably spherical, but it may be irregular.

The coating amount of the inorganic fine particles is preferably from 1 mg / m2 to 100 mg / m2, more preferably from 5 mg / m2 to 80 mg / m2, and still more preferably from 10 mg / m2 to 60 mg / m2. If the amount is too small, a sufficient low refractive index can not be expected or the effect of improving scratch resistance is reduced. If the amount is excessively large, fine irregularities are formed on the surface of the low refractive index layer to deteriorate appearance and integral reflectance such as sharpness of black color.

(Porous or hollow fine particles)

In order to reduce the refractive index, it is preferable to use fine particles of a porous or hollow structure. Particularly, it is preferable to use hollow silica particles. The porosity of these particles is preferably 10 to 80%, more preferably 20 to 60%, and most preferably 30 to 60%. It is preferable that the porosity of the hollow microparticles be in the above-mentioned range from the viewpoints of lowering the refractive index and maintaining the durability of the particles.

In the case of porous or hollow silica particles, the refractive index of the fine particles is preferably 1.10 to 1.40, more preferably 1.15 to 1.35, and most preferably 1.15 to 1.30. Here, the refractive index represents the refractive index as a whole particle and does not represent the refractive index of only the outer silica forming the silica particles.

The hollow silica particles may be used in combination of two or more species having different average particle sizes. Here, the average particle diameter of the hollow silica can be obtained from an electron microscope photograph.

In the present invention, the specific surface area of the hollow silica particles is preferably 20 to 300 m 2 / g, more preferably 30 to 120 m 2 / g, and most preferably 40 to 90 m 2 / g. The surface area can be determined by the BET method using nitrogen.

In the present invention, it is possible to use silica particles having no joint strength in combination with the hollow silica particles. The preferable particle size of the silica having no core is 30 nm or more and 150 nm or less, more preferably 35 nm or more and 100 nm or less, and most preferably 40 nm or more and 80 nm or less.

[Method of surface treatment of inorganic fine particles]

In the present invention, the inorganic fine particles can be surface-treated with a silane coupling agent or the like by a conventional method.

In particular, in order to improve the dispersibility of the binder for forming the antireflection layer, the surface of the inorganic fine particles is preferably treated with the hydrolyzate of the organosilane compound and / or its partial condensate, It is more preferable that either or both of the metal chelate compounds are used. The surface treatment method of the inorganic fine particles is described in paragraphs [0046] to [0076] of Japanese Laid-Open Patent Publication No. 2008-242314, and the organosilane compound, the siloxane compound, the solvent for surface treatment, Catalysts, metal chelate compounds and the like can be preferably used in the present invention.

As the antireflection layer, a fluorine-containing or non-fluorine-containing monomer having a polymerizable unsaturated group (b2) can be used. With respect to the non-fluorine monomer, it is preferable to use a compound having an ethylenically unsaturated double bond group described as being usable in the hard coat layer. As the monomer of fluorine, it is preferable to use a fluorine-containing multifunctional monomer (d) represented by the following general formula (10), containing 35 mass% or more of fluorine and having a calculated value of all cross- .

(10): Rf ₂ {- (L ¹⁰ ) _s -Y ¹⁰ } _t

(10), Rf ₂ represents a t group having at least a carbon atom and a fluorine atom, t represents an integer of 3 or more, L ¹⁰ represents a single bond or a divalent linking group, s represents 0 or 1 Y ¹⁰ represents a polymerizable unsaturated group)

Rf ₂ may contain at least any of an oxygen atom and a hydrogen atom. Rf ₂ is a chain (linear or branched) or cyclic.

Y ¹⁰ is preferably a group containing two carbon atoms forming an unsaturated bond, more preferably a radical polymerizable group, and is preferably a (meth) acryloyl group, an allyl group, an a-fluoroacryloyl group, C (O) is particularly preferably selected from OCH = CH _2. Of these, (meth) acryloyl groups, allyl groups,? -Fluoroacryloyl groups, and C (O) OCH = CH ₂ are more preferable from the viewpoint of polymerizability.

L ¹⁰ represents a divalent linking group and specifically includes an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, -O-, -S-, -N (R) -, an alkylene having 1 to 10 carbon atoms A group obtained by combining a group -O-, -S- or N (R) -, a group obtained by combining -O-, -S- or N (R) - with an arylene group having 6 to 10 carbon atoms. R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. When L represents an alkylene group or an arylene group, the alkylene group and the arylene group represented by L are preferably substituted with a halogen atom, and are preferably substituted with a fluorine atom.

Specific examples of the compound represented by the general formula (1) are described in paragraphs [0121] to [0163] of JP-A-2010-152311.

[Optically anisotropic layer]

The polarizing plate protective film of the present invention may further have an optically anisotropic layer. The optically anisotropic layer may be an optically anisotropic layer in which a film having a constant retardation is uniformly formed in a plane or an optically anisotropic layer in which a retardation region in which phase difference regions are regularly arranged in a plane is formed .

In the present invention, it is preferable that the optically anisotropic layer is formed on the other surface of the surface of the support on which the first and second functional layers are formed.

On the other hand, when the first and second functional layers are laminated on the same side of the support as the optically anisotropic layer, the first and second functional layers may be laminated between the support and the optically anisotropic layer, , And the first and second functional layers may be stacked in this order.

The optically anisotropic layer can be selected depending on the material and manufacturing conditions for various applications, but in the present invention, an optically anisotropic layer using a polymerizable liquid crystal compound is preferable. In this case, it is also preferable that an alignment film is formed between the optically anisotropic layer and the base film in contact with the optically anisotropic layer.

As a preferable example having an optically anisotropic layer uniformly formed in a plane, the optically anisotropic layer is a? / 4 film, and is particularly useful as a member of an active 3D liquid crystal display. An embodiment in which an optically anisotropic layer of a lambda / 4 film and a hard coat layer are laminated on the opposite surface via a base film is described in JP-A-2012-098721 and JP-A-2012-127982, Such an embodiment can be preferably used as a polarizing plate protective film.

On the other hand, a preferred example of the optically anisotropic layer on which the pattern is formed includes a patterned? / 4 film, and the embodiments described in Japanese Patent Publication Nos. 4825934 and 4887463 are preferably used as the polarizer protective film of the present invention .

An embodiment in which a photo alignment film described in Japanese Patent Publication No. 2012-517024 (WO2010 / 090429) is combined with a pattern exposure can also be preferably used as the polarizing plate protective film of the present invention.

[Layer Composition of Polarizing Plate Having Optically Anisotropic Layer]

In the present invention, preferable layer constitution when the polarizing plate protective film has an optically anisotropic layer is shown below.

Optically anisotropic layer / support / first functional layer / second functional layer

Optically anisotropic layer / support / adhesion layer / first functional layer / second functional layer

Optically anisotropic layer / support / first functional layer / second functional layer / antireflection layer

Optically anisotropic layer / support / adhesion layer / first functional layer / second functional layer / antireflection layer

When an optically anisotropic layer is provided, the optically anisotropic layer is preferably formed of a liquid crystal compound having a curable group such as an unsaturated polymerizable group, and it is preferable that an orientation film is formed under the liquid crystal layer. In the present invention, it is also preferable that the alignment film is formed of a curable composition containing a radically polymerizable compound.

[Production method of polarizing plate protective film]

In the method for producing a polarizing plate protective film of the present invention, a first functional layer and a second functional layer are formed on a support so that the first functional layer and the second functional layer are in contact with each other. The first functional layer and the second functional layer are as described above. The other functional layers are as described above.

[Polarizer]

The polarizing plate of the present invention comprises a polarizer and a polarizing plate protective film of the present invention formed as a protective film on at least one side of the polarizing film.

The polarizing plate of the present invention may include a polarizer, a polarizing plate protective film of the present invention formed as a protective film on one surface of the polarizing film, and an optically anisotropic film formed on the other surface of the polarizing film. In this case, the optically anisotropic film may be the same as the optically anisotropic layer.

In the present invention, the production method of the polarizing plate is not particularly limited and can be produced by a general method. There is a method in which the obtained polarizing plate protective film is subjected to alkali treatment, and the polyvinyl alcohol film is immersed and stretched in an iodine solution, and both surfaces of the polarizer are bonded using a fully saponified polyvinyl alcohol aqueous solution. Instead of the alkali treatment, the easy adhesion treatment described in JP-A-6-94915 and JP-A-6-118232 may be carried out. The above surface treatment may also be carried out. The surface of the polarizing plate protective film to be adhered to the polarizer may be a surface on which the first and second functional layers are laminated or a surface on which the first and second functional layers are not laminated.

Examples of the adhesive used for bonding the protective film treated surface and the polarizer include a polyvinyl alcohol-based adhesive such as polyvinyl alcohol and polyvinyl butyral, and a vinyl-based latex such as butyl acrylate .

The polarizing plate is composed of a polarizer and a protective film for protecting both surfaces of the polarizer, and a protective film is bonded to one surface of the polarizing plate and a separate film is bonded to the opposite surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate when the polarizing plate is shipped, when the product is inspected. In this case, the protective film is adhered for the purpose of protecting the surface of the polarizing plate, and is used on the opposite side of the surface to which the polarizing plate is adhered to the liquid crystal plate. The separate film is used for the purpose of covering the adhesive layer to be laminated on the liquid crystal plate, and is used on the side where the polarizing plate is bonded to the liquid crystal plate.

[Image display device]

An image display apparatus of the present invention comprises a liquid crystal cell and a polarizing plate of the present invention disposed on at least one side of the liquid crystal cell, and the polarizing plate protective film of the present invention contained in the polarizing plate is disposed on the image displaying surface. Examples of the image display device include a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), a cathode ray tube display (CRT) And the like.

{General Configuration of Liquid Crystal Display}

The liquid crystal display device has a configuration in which at least one optical compensation film is disposed between a liquid crystal cell in which liquid crystal is supported between two electrode substrates, two polarizing plates disposed on both sides of the liquid crystal cell, and if necessary, between the liquid crystal cell and the polarizing plate I have.

The liquid crystal layer of the liquid crystal cell is usually formed by enclosing liquid crystal in a space formed by interposing spacers between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. In the liquid crystal cell, a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for bonding the transparent electrode layer) may be further formed. These layers are usually formed on a substrate. The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.

In the liquid crystal display device, a substrate including a liquid crystal cell is usually disposed between two polarizing plates, but the protective film for a polarizing plate of the present invention can be used as any one of two polarizing plates. Of the two protective films of each polarizing plate, It is preferably used as a protective film disposed outside the liquid crystal cell with respect to the polarizer.

It is particularly preferable to arrange the polarizing plate protective film of the present invention as a protective film on the viewer side of the viewer-side polarizing plate among the two polarizing plates.

Of the two polarizing plates, the polarizing plate protective film of the present invention was disposed as a protective film on the viewer side of the viewer-side polarizing plate, and then the polarizing plate protective film of the present invention was also disposed on the backlight- It is also preferable to suppress the expansion and contraction of the polarizer included in the two polarizing plates and to prevent the panel from warping.

{Kind of liquid crystal display device}

The polarizing plate protective film of the present invention can be used for liquid crystal cells of various display modes. (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (Super Twisted Nematic) Various display modes such as ECB (Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic) have been proposed. A display mode in which the display mode is divided into orientations is also proposed. The polarizing plate protective film of the present invention is effective also in a liquid crystal display device of any display mode. It is also effective in any of liquid crystal display devices of transmission type, reflection type, and semi-transmission type.

Example

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

[Example 1]

(Preparation of Coating Composition for First Functional Layer)

Each component was mixed with the following composition and filtered through a polypropylene filter having a diameter of 5 탆 to prepare a coating composition for forming a first functional layer.

&Lt; Preparation of first functional layer-forming coating composition &gt;

A-DCP 45.62 parts by mass

Fine Crystal KR-614 8.25 parts by mass

Irgacure 907 1.10 parts by mass

Fluoroaliphatic group-containing copolymer (a) (solid concentration: 1 mass% MEK diluent) 2.75 mass parts

MEK (methyl ethyl ketone) 10.78 parts by mass

MiBK (methyl isobutyl ketone) 31.50 parts by mass

(Preparation of Coating Composition for Second Functional Layer)

Each component was added to the following composition and filtered through a polypropylene filter having a diameter of 10 탆 to prepare a coating composition for forming a second functional layer.

&Lt; Preparation of Coating Composition for Second Functional Layer Formation &gt;

UA306H 36.80 parts by mass

Irgacure 184 1.20 parts by mass

Average particle diameter 2.0 占 퐉 crosslinked methyl methacrylate-styrene copolymer particle solid content concentration 30 mass% toluene dispersion 6.68 mass parts

Toluene 43.33 parts by mass

Cyclohexanone 12.00 parts by mass

&Lt; Coating Formation of First Functional Layer &gt;

As a support, Fujitac TD60 (manufactured by Fuji Film Co., Ltd., width 1340 mm, thickness 60 占 퐉) was loosened from the roll form and the coating composition for forming the first functional layer was used to carry out the method disclosed in Japanese Laid-Open Patent Publication No. 2006-122889 Was applied by a die coating method using the slot die described in Example 1 under the conditions of a conveying speed of 30 m / min and dried at 60 캜 for 150 seconds. Thereafter, an ultraviolet ray having an illuminance of 400 mW / cm 2 and an irradiation dose of 150 mJ / cm 2 was irradiated using a cold air-cooled metal halide lamp (manufactured by E Graphics Co., Ltd.) with a nitrogen peroxide concentration of about 0.1% to 160 W / cm The coating layer was cured and wound. The coating amount was adjusted so that the film thickness of the first functional layer was 15 占 퐉.

&Lt; Coating Formation of Second Functional Layer &gt;

Subsequently, the film on which the first functional layer was formed was released from the form of a roll, and using the coating composition for forming a second functional layer, a die coat using the slot die described in Example 1 of JP-A-2006-122889 Method at a conveying speed of 30 m / min, and dried at 60 DEG C for 150 seconds. Thereafter, an ultraviolet ray having an illuminance of 400 mW / cm &lt; 2 &gt; and an irradiance of 200 mJ / cm &lt; 2 &gt; was irradiated by using a cold air-cooled metal halide lamp (manufactured by E Graphics Co., Ltd.) The coating layer was cured and wound up to produce a polarizing plate protective film. The coating amount was adjusted so that the film thickness for the second functional layer was 4 占 퐉. The resulting polarizing plate protective film was used as sample 1.

Next, as shown in Table 1 below, a coating composition for forming a first functional layer was prepared by changing the kind and amount of the fluoroaliphatic group-containing copolymer and the kind of the curable compound for a binder. Further, as shown in Table 1 below, the kind of the binder was changed to prepare a second functional layer-forming coating composition. The coating composition for forming the first functional layer and the coating composition for forming the second functional layer were coated so as to have the thicknesses shown in Table 1 below to obtain polarizing plate protective film samples 2 to 27. The addition amount of the fluoro aliphatic group-containing copolymer in Table 1 is the ratio (mass%) in the total solid content of the first functional layer-forming coating composition.

The materials used are shown below.

A-DCP: tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

AD-DA: 1,3-adamantanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

UA306H: urethane prepolymer composed of pentaerythritol triacrylate and hexamethylene diisocyanate (manufactured by Kyowa Chemical Industry Co., Ltd.)

UV-1700B (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)

· Fine Crystal KR-614 [manufactured by Arakawa Chemical Industries, Ltd.]

Irgacure 907 [manufactured by BASF]

· Irgacure 184 [manufactured by BASF]

[Chemical Formula 21]

However, the A-DCP has the same structure as the exemplified compound M-5 of the curing compound for a binder having the cyclic aliphatic hydrocarbon group and the ethylenically unsaturated double bond group.

[Chemical Formula 22]

The structures of the fluoroaliphatic group-containing copolymers (a) to (1) used are shown below. The content ratio of each repeating unit is a mass ratio. The weight average molecular weights of the fluoroaliphatic group-containing copolymers (a) to (l) used were all 12,000.

(23)

&Lt; EMI ID =

(25)

(Evaluation of polarizing plate protective film)

Each of the prepared polarizing plate protective films was evaluated as follows. The evaluation results are shown together in Table 1 below.

<1> Adhesion

The evaluation was carried out by the cross-cut method described in JIS-K-5600-5-6-1. That is, 100 checkerboard eyes were placed at the intervals of 1 mm on the surface of the polarizing plate protective film sample, and then peeled off after attaching a cellophane tape (manufactured by Nichiban Co., Ltd.). In the present invention, A and B are acceptable levels.

A: Square peeling does not occur in checkerboard

B: It is more than 90% that there is no peeling of the square among the checkered eyes

C: 50% or more and less than 90% of the checkered eyes without peeling of the square

D: Less than 50% of squares with no peeling of the square

<2> Unevenness due to wind

The polarizing plate protective film sample thus obtained was observed under a diffuse light of a triple-wavelength fluorescent lamp with a louver, and the unevenness due to wind was evaluated. Here, the unevenness due to wind is a striped shape formed in a direction substantially parallel to the traveling direction of the transparent support. In the present invention, A and B are acceptable levels.

A: There is no wind-induced irregularity even if the uncoated surface is blackened.

B: If you apply uncoated surface black, there is unevenness due to wind, but if you do not paint black, you do not know.

C: Unevenness due to wind can be seen even if the uncoated surface is not painted black

&Lt; 3 &gt;

The presence or absence of sieving in 1 m &lt; 2 &gt; of the obtained polarizing plate protective film samples was visually checked and judged according to the following criteria. In the present invention, A is an acceptable level.

A: There is no sissing.

B: There is more than 1 and less than 10 siching.

C: There are more than 10 siching

[Example 2]

Comparative Sample 28 was prepared in the same manner as Sample 1 except that the binder in the second functional layer in Example 1 was changed from UA306H to PET-30 (manufactured by Nippon Kayaku Co., Ltd.) Respectively.

(Evaluation of polarizing plate protective film)

The prepared polarizing plate protective films (Sample 1 and Comparative Sample 28) were evaluated for brittleness described below. The evaluation results are shown in Table 2 below.

&Lt; 4 &gt;

The sample 1 and the comparative sample 28 were evaluated for brittleness using the paint general test method described in JIS-K-5600-5-1-flexural resistance (cylindrical mandrel method). That is, after each sample was stored for 16 hours under the conditions of a temperature of 25 占 폚 and a humidity of 55% RH, the samples were wound on mandrels having diameters of 2, 3, 4, 5, 6, 8, 10 and 12 mm, respectively, The condition was observed to evaluate the crack resistance at the minimum mandrel diameter at which no crack occurred. The larger the diameter of the mandrel is, the smaller the crack resistance is.

Claims (11)

A support, a first functional layer, and a second functional layer in this order,
The first functional layer and the second functional layer being in contact with each other,
Wherein the first functional layer is a layer formed by using a composition for forming a first functional layer containing (A) and (B)
The content of the following component (A) in the composition for forming a first functional layer is from 0.005 mass% to 1 mass% with respect to the total solid content in the composition for forming a first functional layer,
Wherein the second functional layer is a layer formed using a composition containing urethane acrylate.
(A) at least one kind of repeating unit derived from a fluoroaliphatic group-containing monomer represented by the following general formula (1) and at least one kind of a repeating unit derived from a monomer represented by the following general formula (2) A fluoroaliphatic group-containing copolymer having a mass ratio of a repeating unit derived from a monomer represented by the following general formula (1) to a repeating unit derived from a monomer represented by the following general formula (2) is from 99: 1 to 50:50
[Chemical Formula 1]

(In the general formula (1), R ⁰ represents a hydrogen atom, a halogen atom or a methyl group, L represents a divalent linking group, and q represents an integer of 1 or more and 18 or less)
(2)

(In the general formula (2), R ¹ represents a hydrogen atom, a halogen atom or a methyl group, L ⁴ represents a divalent linking group containing either an oxygen atom, a nitrogen atom or a sulfur atom, or a single bond, Y is _{-OH, -COOH, -SO 3 H,} -PO (OH) 2, -OPO (OH) 2, and - represents a group selected from _{(C 2 H 4 O) mH} m represents an integer of 1 or more)
(B) a curing compound for a binder having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated double bond group The method according to claim 1,
Wherein the composition for forming a first functional layer further contains a rosin compound. The method according to claim 1,
Wherein L in the general formula (1) is -COO- (R ² ) -.
Provided that R ² represents an alkylene group having 1 to 8 carbon atoms The method according to claim 1,
L &lt; ⁴ &gt; in the general formula (2) is a single bond, and Y is -COOH. 5. The method according to any one of claims 1 to 4,
Wherein a thickness of the first functional layer is not less than 3 占 퐉 and not more than 25 占 퐉. 5. The method according to any one of claims 1 to 4,
And the film thickness of the second functional layer is not less than 2 占 퐉 and not more than 7 占 퐉. 5. The method according to any one of claims 1 to 4,
Wherein the support has a film thickness of 20 mu m or more and 70 mu m or less. The method for producing a polarizing plate protective film according to any one of claims 1 to 4, wherein the first functional layer and the second functional layer are formed on the support such that the first functional layer and the second functional layer are in contact with each other . A polarizer comprising the polarizer protective film according to any one of claims 1 to 4, which is formed as a protective film on at least one surface of the polarizer. A polarizer comprising a polarizer, a polarizer protective film according to any one of claims 1 to 4 formed as a protective film on one surface of the polarizer, and an optically anisotropic film formed on the other surface of the polarizer. 10. The image display device according to claim 9, comprising a liquid crystal cell and a polarizing plate according to claim 9 arranged on at least one side of the liquid crystal cell, wherein the polarizing plate protective film is disposed on an image display surface.