JP2016194566A - Low moisture-permeable hard coat film, polarizing plate, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low moisture-permeable hard coat film having high hardness and low moisture permeability and less likely inducing whitening in a moisture-heat environment.SOLUTION: The low moisture-permeable hard coat film includes a cellulose ester substrate and a low moisture-permeable hard coat layer, in which the low moisture-permeable hard coat layer is formed from a composition comprising the following components (A) to (E), and content ratios of (A), (B) and (C) are within a predetermined range in a phase diagram of a ternary system shown in the figure. The components are: (A) a compound having at least three ethylenically unsaturated double bond groups in one molecule; (B) a compound having a molecular weight of 270 or less and at least two epoxy groups in one molecule, in which at least one epoxy group is an alicyclic epoxy group; (C) a compound having a molecular weight of 300 or less and one alicyclic epoxy group and one ethylenically unsaturated double bond group in one molecule; (D) a radical polymerization initiator; and (E) a cationic polymerization initiator.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a low moisture-permeable hard coat film, a polarizing plate, and an image display device that have high hardness, low moisture permeability, and can suppress surface whitening.

  In recent years, liquid crystal display devices have been widely used for liquid crystal panels such as liquid crystal televisions, personal computers, mobile phones, and digital cameras. Usually, 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 backlight member with the liquid crystal panel member. A polarizing plate comprises a polarizer and its protective film (polarizing plate protective film), and a general polarizer is obtained by stretching a polyvinyl alcohol (PVA) film dyed with iodine or a dichroic dye. For example, a cellulose ester film is used as the protective film.

  Recent liquid crystal display devices are becoming more and more demanding, and the demands for durability are becoming stricter as the quality of the liquid crystal display devices increases. As durability, improvement in the hardness of the protective film on the surface is required. In addition, for example, when used 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 also have dimensions and optical characteristics with respect to temperature and humidity changes. It is required to suppress changes.

  Compositions that can form a hard coat layer with high surface hardness include compounds having (meth) acryloyl groups in the molecule, compounds having epoxy groups in the molecule, (meth) acryloyl groups and cationic polymerizable properties. Patent Document 1 describes a composition containing a compound having a group in a molecule with a specific content.

Japanese Patent Laid-Open No. 2003-252954

  However, the hard coat layer formed from the composition described in Patent Document 1 has insufficient hardness, high moisture permeability, and the compound having an epoxy group in the molecule under high-temperature and high-humidity conditions I started crying and turned white.

Therefore, an object of the present invention is to provide a low moisture-permeable hard coat film having high hardness, low moisture permeability, and hardly whitening in a moist heat environment.
Another object of the present invention is to provide a polarizing plate and an image display device using the low moisture permeability hard coat film.

  The above problem can be solved by the following means.

[1]
A low moisture-permeable hard coat film having a cellulose ester base material and a low moisture-permeable hard coat layer,
The low moisture permeability hard coat layer is formed from a composition containing the following (A) to (E):
The content ratios of the following compositions (A), (B), and (C) in the three-component phase diagram are (80, 10, 10), (10, 10, 80), ( 10, 50, 40), a low moisture-permeable hard coat film in a range surrounded by (40, 50, 10).
(A) Compound having 3 or more ethylenically unsaturated double bond groups in one molecule (B) Molecular weight is 270 or less, 2 or more epoxy groups in 1 molecule, Compound in which at least one of them is an alicyclic epoxy group (C) The molecular weight is 300 or less, and it has one alicyclic epoxy group and one ethylenically unsaturated double bond group in one molecule. Compound (D) Radical polymerization initiator (E) Cationic polymerization initiator [2]
The low moisture-permeable hard coat film according to [1], wherein (B) is a compound represented by the following general formula (1).

In said general formula (1), R < ₁₁ >, R < ₁₂ >, R <_13> , R <_14> and R < ₁₅ > represent a hydrogen atom, a methyl group, or an ethyl group each independently.
X includes a single bond or an alkylene group that may have a substituent, an arylene group that may have a substituent, an aralkylene group that may have a substituent, an ester bond, an ether bond, or a heterocyclic ring. A (m + n) -valent linking group comprising a linking group or a combination thereof is represented.
m and n each independently represent an integer of 0 or more and 2 or less, and m + n ≧ 2.
When there are a plurality of R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ , the plurality of R ₁₁ , the plurality of R ₁₂ , the plurality of R ₁₃ , the plurality of R ₁₄ and the plurality of R ₁₅ are the same or different. It may be.
[3]
The low moisture-permeable hard coat film according to [1] or [2], wherein (B) is a compound represented by the following general formula (2).

In said general formula (2), R <_16> , R <_17> , R <_18> and R < ₁₉ > represent a hydrogen atom, a methyl group, or an ethyl group each independently.
Y includes a single bond or an alkylene group that may have a substituent, an arylene group that may have a substituent, an aralkylene group that may have a substituent, an ester bond, an ether bond, and a heterocyclic ring. A divalent linking group comprising a linking group or a combination thereof is represented.
[4]
The low moisture-permeable hard coat film according to any one of [1] to [3], wherein (B) is 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate.
[5]
The low moisture-permeable hard coat film according to any one of [1] to [4], wherein (C) is a compound represented by the following general formula (3).

In the general formula (3), R represents a monocyclic hydrocarbon or a bridged hydrocarbon, L represents a single bond or a divalent linking group, and Q represents an ethylenically unsaturated double bond group.
[6]
The low moisture-permeable hard coat film according to any one of [1] to [5], wherein (C) is epoxycyclohexylmethyl (meth) acrylate.
[7]
The low moisture-permeable hard coat film according to any one of [1] to [6], wherein an average film thickness of the low moisture-permeable hard coat layer is 5 μm or more.
[8]
The polarizing plate containing a polarizer and the low moisture-permeable hard coat film in any one of [1]-[7] provided as a protective film in the at least one surface of the said polarizer.
[9]
The polarizer, the low moisture-permeable hard coat film according to any one of [1] to [7] provided as a protective film on one surface of the polarizer, and the other surface of the polarizer An optical compensation film having optical anisotropy.
[10]
An image comprising a liquid crystal cell and the polarizing plate according to [8] or [9] disposed on at least one surface of the liquid crystal cell, wherein the low moisture-permeable hard coat film is disposed on the image display surface side. Display device.

  According to the present invention, it is possible to provide a low moisture-permeable hard coat film that has high hardness, low moisture permeability, and hardly causes whitening in a moist heat environment. Moreover, according to this invention, the polarizing plate using the said low moisture-permeable hard coat film, and an image display apparatus can be provided.

It is a state figure showing the content ratio (mass ratio) of 3 component type | system | groups of the (A) component in the composition for low moisture-permeable hard-coat layer formation of this invention, (B) component, and (C) component. It is a state figure showing the content ratio (mass ratio) of the 3 component system of the (A) component in the composition for hard-coat layer formation of the samples 1-13, (B) component, and (C) component.

  Hereinafter, preferred embodiments according to the low moisture-permeable hard coat film, the polarizing plate and the image display device of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In addition, in this specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”. “Acrylic resin” means a resin obtained by polymerizing a methacrylic acid or a derivative of acrylic acid, and a resin containing the derivative. Further, when not particularly limited, “(meth) acrylate” represents acrylate and methacrylate, and “(meth) acryl” represents acryl and methacryl.

The low moisture permeability hard coat film of the present invention is a low moisture permeability hard coat film having a cellulose ester base material and a low moisture permeability hard coat layer,
The low moisture-permeable hard coat layer is formed from a composition containing the following (A) to (E) (also referred to as “low moisture-permeable hard coat layer forming composition”),
The content ratios of the following compositions (A), (B), and (C) in the three-component phase diagram are (80, 10, 10), (10, 10, 80), ( 10, 50, 40) and (40, 50, 10), a low moisture-permeable hard coat film.
(A) Compound having 3 or more ethylenically unsaturated double bond groups in one molecule (B) Molecular weight is 270 or less, 2 or more epoxy groups in 1 molecule, Compound in which at least one of them is an alicyclic epoxy group (C) The molecular weight is 300 or less, and it has one alicyclic epoxy group and one ethylenically unsaturated double bond group in one molecule. Compound (D) Radical polymerization initiator (E) Cationic polymerization initiator

  The low moisture-permeable hard coat film of the present invention may have a low moisture-permeable hard coat layer directly on at least one surface of the cellulose ester substrate, or the low moisture-permeable hard coat film via another layer. It may have a coat layer.

[(A) Compound having 3 or more ethylenically unsaturated double bond groups in one molecule]
“(A) Compound having three or more ethylenically unsaturated double bond groups in one molecule” (“(A) component” or “(A)” contained in the composition for forming a low moisture-permeable hard coat layer in the present invention Compound (A) ”) will be described.
(A) component can express high hardness by having three or more ethylenically unsaturated double bond groups in a molecule | numerator.
Examples of the ethylenically unsaturated double bond group in the component (A) include a (meth) acryloyl group, a vinyl group, a styryl group, or an allyl group, and a (meth) acryloyl group is more preferable.

Examples of the component (A) include esters of polyhydric alcohol and (meth) acrylic acid, vinylbenzene and its derivatives, vinyl sulfone, (meth) acrylamide, and the like. Among them, from the viewpoint of hardness, a compound having three or more (meth) acryloyl groups is preferable, and examples thereof include acrylate compounds that form a hardened cured product widely used in the industry. Examples of such compounds include esters of polyhydric alcohol and (meth) acrylic acid {for example, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified tris. Methylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO-modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate DOO, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.
As specific compounds of polyfunctional acrylate compounds having three or more (meth) acryloyl groups, KAYARAD DPHA, DPHA-2C, PET-30, TMPTA, and TPA-320 manufactured by Nippon Kayaku Co., Ltd. TPA-330, RP-1040, T-1420, D-310, DPCA-20, DPCA-30, DPCA-60, GPO-303, Shin-Nakamura Chemical Co., Ltd. A- DPH, A-9550W, A-TMMT, A-TMM-3, A-TMM-3L, A-TMM-3LM-N, Osaka Organic Chemical Industries, Ltd. V # 400, V # 36095D And an esterified product of a polyol such as (meth) acrylic acid. Also, purple light UV-1400B, UV-1700B, UV-6300B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7620EA, UV-7630B, UV-7630B, UV-7640B. UV-6630B, UV-7000B, UV-7510B, UV-7461TE, UV-3000B, UV-3200B, UV-3210EA, UV-3210EA, UV-3310EA, UV-3310B, UV-3500BA , UV-3520TL, UV-3700B, UV-6100B, UV-6640B, UV-2000B, UV-2010B, UV-2250EA, UV-2750B (manufactured by Nippon Synthetic Chemical Co., Ltd.), UL-503LN (manufactured by Kyoeisha Chemical Co., Ltd.), Unidic 17-80 17-813, V-4030, V-4000BA (Dainippon Ink Chemical Co., Ltd.), EB-1290K, EB-220, EB-5129, EB-1830, EB-4358 (Daicel UCB ( Ltd.), High Corp AU-2010, AU-2020 (manufactured by Tokushi Co., Ltd.), Aronix M-1960 (manufactured by Toagosei Co., Ltd.), Art Resin UN-3320HA, UN-3320HC, UN-3320HS, UN Trifunctional urethane acrylate compounds such as -904, HDP-4T, Aronix M-8100, M-8030, M-9050 (manufactured by Toagosei Co., Ltd., KBM-8307 (manufactured by Daicel Cytec Co., Ltd.)) The above polyester compounds and the like can also be suitably used.
Moreover, (A) component may be comprised from a single compound, and can also be used in combination of a some compound.

[(B) Compound having a molecular weight of 270 or less, having two or more epoxy groups in one molecule, and at least one of the epoxy groups being an alicyclic epoxy group]
“(B) molecular weight of 270 or less, 2 or more epoxy groups in one molecule, and at least one of the epoxy groups contained in the composition for forming a low moisture-permeable hard coat layer in the present invention” Is a alicyclic epoxy group "(also referred to as" component (B) "or" compound (B) ").
When the molecular weight of the component (B) is 270 or less, the molecular weight between crosslinks in the polymer can be reduced, the hardness can be increased, and the moisture permeability can be lowered. The molecular weight of the component (B) is preferably 140 or more and 260 or less, and more preferably 200 or more and 260 or less.

  The component (B) preferably has 2 or 3 epoxy groups in one molecule, and more preferably has 2 epoxy groups.

  As the cyclic skeleton of the alicyclic epoxy group which component (B) has, cycloalkane rings such as cyclohexane ring, cyclopentane ring, cyclooctane ring and bicycloheptane ring are preferable, and cyclohexane ring is more preferable.

  The component (B) is preferably a compound represented by the following general formula (1).

In said general formula (1), R < ₁₁ >, R < ₁₂ >, R <_13> , R <_14> and R < ₁₅ > represent a hydrogen atom, a methyl group, or an ethyl group each independently.
X includes a single bond or an alkylene group that may have a substituent, an arylene group that may have a substituent, an aralkylene group that may have a substituent, an ester bond, an ether bond, or a heterocyclic ring. A (m + n) -valent linking group comprising a linking group or a combination thereof is represented.
m and n each independently represent an integer of 0 or more and 2 or less, and m + n ≧ 2.
When there are a plurality of R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ , the plurality of R ₁₁ , the plurality of R ₁₂ , the plurality of R ₁₃ , the plurality of R ₁₄ and the plurality of R ₁₅ are the same or different. It may be.

R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ each independently preferably represent a hydrogen atom or a methyl group, and more preferably all represent a hydrogen atom.

X includes a single bond or an alkylene group that may have a substituent, an arylene group that may have a substituent, an aralkylene group that may have a substituent, an ester bond, an ether bond, or a heterocyclic ring. A (m + n) -valent linking group comprising a linking group or a combination thereof is represented.
Examples of the alkylene group include a linear, branched or cyclic alkylene group, an alkylene group having 1 to 10 carbon atoms is preferable, and an alkylene group having 1 to 8 carbon atoms is more preferable. Specific examples include a methylene group, a propylene group, and a cyclohexylene group.
As the arylene group, an arylene group having 6 to 12 carbon atoms is preferable, and a phenylene group and a fluorene group are preferable.
As the aralkylene group, an alkylene group composed of a preferable range of the alkylene group and a preferable range of the arylene group is preferable.
As the linking group containing a heterocyclic ring, a linking group containing a xanthene skeleton or a carbazole skeleton is preferable.

  The alkylene group, arylene group, aralkylene group or heterocyclic ring represented by X may have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, an acyl group, an acyloxy group, and an alkoxycarbonyl group.

  X is preferably a single bond, an alkylene group, an ester bond, an ether bond, a linking group consisting of an alkylene group and an ester bond, or a linking group consisting of an alkylene group and an ether bond.

  m is preferably 1 or 2, and n is preferably 0 or 1. m + n is preferably 2 or 3.

  The component (B) is more preferably a compound represented by the following general formula (2).

In said general formula (2), R <_16> , R <_17> , R <_18> and R < ₁₉ > represent a hydrogen atom, a methyl group, or an ethyl group each independently.
Y includes a single bond or an alkylene group that may have a substituent, an arylene group that may have a substituent, an aralkylene group that may have a substituent, an ester bond, an ether bond, and a heterocyclic ring. A divalent linking group comprising a linking group or a combination thereof is represented.

Preferable ranges of R ₁₆ , R ₁₇ , R ₁₈ and R ₁₉ are the same as R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R _{15 in} the general formula (1).
The preferable range of Y is the same as X of General formula (1).

  Although the specific example of (B) component is given to the following, it is not limited to these. In the present invention, as the component (B), 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate represented by the following compound 2c is particularly preferable.

[(C) Compound having a molecular weight of 300 or less and having one alicyclic epoxy group and one ethylenically unsaturated double bond group in one molecule]
“(C) molecular weight is 300 or less, contained in the composition for forming a low moisture-permeable hard coat layer in the present invention, one alicyclic epoxy group and one ethylenically unsaturated double per molecule” The “compound having a bonding group” (also referred to as “(C) component” or “compound (C)”) will be described.

  The combined use of the component (A) and the component (B) can specifically reduce the moisture permeability of the formed layer, but there is a problem that the film surface is whitened under a high temperature and high humidity environment. Occur. In the present invention, by further containing the component (C) at a specific mass ratio, the component (A) and the component (B) are bonded via the component (C), thereby suppressing the occurrence of whitening. It is considered possible.

Examples of the ethylenically unsaturated double bond group of component (C) include polymerizable functional groups such as (meth) acryloyl group, vinyl group, styryl group, and allyl group, and (meth) acryloyl group is preferable. . By having an ethylenically unsaturated double bond group, it is possible to maintain high hardness and to impart moisture and heat resistance.
As the cyclic skeleton of the alicyclic epoxy group which component (C) has, a cycloalkane ring such as a cyclohexane ring, a cyclopentane ring, a cyclooctane ring or a bicycloheptane ring is preferable, and a cyclohexane ring is more preferable.
In the component (C), the number of alicyclic epoxy groups and ethylenically unsaturated double bond groups in each molecule is one. When each functional group is one, the total molecular weight can be 300 or less, and the hardness of the resulting film can be improved.

Although the molecular weight of (C) component is 300 or less, 210 or less are preferable and 200 or less are more preferable.
Further, from the viewpoint of suppressing volatilization during formation of the low moisture permeability hard coat layer, the molecular weight of the component (C) is preferably 100 or more, and more preferably 150 or more.

  The component (C) is preferably a compound represented by the following general formula (3).

  In general formula (3), R represents a monocyclic hydrocarbon or a bridged hydrocarbon, L represents a single bond or a divalent linking group, and Q represents an ethylenically unsaturated double bond group.

When R in the general formula (3) is a monocyclic hydrocarbon, it is preferably an alicyclic hydrocarbon, more preferably an alicyclic group having 4 to 10 carbon atoms, and an aliphatic group having 5 to 7 carbon atoms. A cyclic group is more preferable, and an alicyclic group having 6 carbon atoms is particularly preferable. Specifically, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group are preferable, and a cyclohexyl group is particularly preferable.
When R in the general formula (3) is a bridged hydrocarbon, a bicyclic bridge (bicyclo ring) or a tricyclic bridge (tricyclic ring) is preferable, and examples thereof include a bridged hydrocarbon having 5 to 20 carbon atoms, and norbornyl Group, bornyl group, isobornyl group, tricyclodecyl group, dicyclopentenyl group, dicyclopentanyl group, tricyclopentenyl group, tricyclopentanyl group, adamantyl group, C1-C4 lower alkyl group substituted adamantyl Groups and the like.
When L represents a divalent linking group, a divalent aliphatic hydrocarbon group is preferred. As a bivalent aliphatic hydrocarbon group, 1-6 are preferable, as for carbon number, 1-3 are more preferable, and 1 is still more preferable. As the divalent aliphatic hydrocarbon group, a linear, branched or cyclic alkylene group is preferable, a linear or branched alkylene group is more preferable, and a linear alkylene group is still more preferable.
Examples of Q include polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group and —C (O) OCH═CH ₂ are preferable and particularly preferable. Is a (meth) acryloyl group.

Specific examples of the component (C) are not particularly limited, and the compound represented by paragraph [0015] of JP-A-10-17614 and the following general formula (C-1) or (C-2) 1,2-epoxy-4-vinylcyclohexane and the like.
Especially, the compound represented by the following general formula (C-1) or (C-2) is more preferable, and the compound represented by the following general formula (C-1) is still more preferable.

In General Formula (C-1), R ₁ represents a hydrogen atom or a methyl group, and L ₁ represents a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms. In the formula of the general formula (C-1), L ₁ represents a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and epoxy cyclohexylmethyl (1 carbon atom). More preferred is (meth) acrylate.

In General Formula (C-2), R ₂ represents a hydrogen atom or a methyl group, and L ₂ represents a divalent aliphatic hydrocarbon group having 1 to 3 carbon atoms. The divalent aliphatic hydrocarbon group represented by L ₂ in the general formula (C-2) is preferably a linear, branched or cyclic alkylene group, and a linear or branched alkylene group. Is more preferable, and a linear alkylene group is still more preferable. By using these compounds represented by (C-1) or (C-2), higher hardness can be realized.

[Content ratio of component (A), component (B), component (C) in the composition for forming a low moisture permeability hard coat layer]
The content ratio of the component (A), the component (B), and the component (C) in the composition for forming a low moisture-permeable hard coat layer in the present invention is (80, 10) by mass ratio in the three-component phase diagram. , 10), (10, 10, 80), (10, 50, 40), and (40, 50, 10). More specifically, the content ratio of the component (A), the component (B), and the component (C) is represented by a mass ratio of (80, 10, 10) with respect to the point A, (10, (10, 80) is point B, (10, 50, 40) is point C, and (40, 50, 10) is point D. Inside and on each side of a rectangle with points A to D as vertices It is within the range of the area.

The content ratio of the component (A), the component (B), and the component (C) will be described with reference to the drawings. FIG. 1 is a state diagram showing the content ratio (mass ratio) of a three-component system of the component (A), the component (B), and the component (C) in the low moisture-permeable hard coat layer forming composition of the present invention. .
In the present invention, in FIG. 1, 3 is within the range surrounded by ■ (80, 10, 10), ◆ (10, 10, 80), ● (10, 50, 40), and ▲ (40, 50, 10). There is content of ingredients. Among them, the content of the three components is preferably within the range surrounded by (70, 15, 15), (15, 15, 70), (15, 45, 40), (40, 45, 15), 60, 20, 20), (20, 20, 60), (20, 40, 40), and a content of three components are particularly preferably within the range surrounded by (40, 40, 20).
As shown in FIG. 1, by adjusting the content ratio of the component (A), the component (B), and the component (C) in the low moisture permeability hard coat layer composition, the hardness is high, A low moisture permeability hard coat film having low moisture permeability and capable of suppressing whitening in a moist heat environment can be obtained.

[(D) radical polymerization initiator]
The (D) radical polymerization initiator contained in the composition for forming a low moisture permeability hard coat layer in the present invention will be described. “(D) Radical polymerization initiator” is also referred to as “(D) component”.
Polymerization of the compound having an ethylenically unsaturated group double bond group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical polymerization initiator or a thermal radical polymerization initiator. Commercially available compounds can be used as the photo and thermal polymerization initiators, and they are described in “Latest UV Curing Technology” (p. 159, publisher: Kazuhiro Takahisa, publisher; Technical Information Association, 1991). Issued) and Ciba Specialty Chemicals catalog.
Specific examples of the component (D) include alkylphenone-based photopolymerization initiators (Irgacure 651, Irgacure 184, DAROCURE 1173, Irgacure 2959, Irgacure 127, DAROCUREMBBF, Irgacure 907, Irgacure 369, Irgacure 369, Ergacure 37 Photogase , LUCIRINTPO) and others (Irgacure 784, Irgacure OXE01, Irgacure OXE02, Irgacure 754) and the like (above, manufactured by BASF) can be used.
When the total content of the component (A), the component (B), and the component (C) of the low moisture-permeable hard coat layer forming composition is 100% by mass, It is preferable that it is the range of 0.1-10 mass%, 0.5-8 mass% is more preferable, and 1-7 mass% is still more preferable. These radical initiators may be used alone or in combination of two or more.

[(E) Cationic polymerization initiator]
The (E) cationic polymerization initiator contained in the composition for forming a low moisture permeability hard coat layer in the present invention will be described. “(E) Cationic polymerization initiator” is also referred to as “(E) component”.
As the component (E), known compounds such as photo-initiators for photo-cationic polymerization, photo-decoloring agents for dyes, photo-discoloring agents, or known acid generators used in micro-resist, etc. and their compounds A mixture etc. are mentioned.
Examples thereof include onium compounds, organic halogen compounds, and disulfone compounds. Specific examples of these organic halogen compounds and disulfone compounds are the same as those described above for the compounds that generate radicals.

  Examples of the onium compounds include diazonium salts, ammonium salts, iminium salts, phosphonium salts, iodonium salts, sulfonium salts, arsonium salts, selenonium salts, and the like, for example, paragraph numbers [0058] to [0059] of JP-A-2002-29162. And the like.

  In the present invention, particularly preferable cationic polymerization initiators include onium salts, and diazonium salts, iodonium salts, sulfonium salts, and iminium salts are suitable for photopolymerization initiation photosensitivity, compound material stability, and the like. Of these, iodonium salts are most preferable from the viewpoint of light resistance.

  Specific examples of onium salts that can be suitably used in the present invention include acylated sulfonium salts described in paragraph No. [0035] of JP-A-9-268205 and JP-A-2000-71366. A diaryl iodonium salt or a triarylsulfonium salt described in paragraphs [0010] to [0011], a sulfonium salt of thiobenzoic acid S-phenyl ester described in paragraph [0017] of JP-A-2001-288205, Examples thereof include the onium salts described in paragraph numbers [0030] to [0033] of JP-A-2001-133696.

  Other examples include organometallic / organic halides described in JP-A-2002-29162, paragraphs [0059] to [0062], photoacid generators having o-nitrobenzyl type protecting groups, photolysis And compounds that generate sulfonic acid (iminosulfonate, etc.).

  Specific compounds of the iodonium salt-based cationic polymerization initiator include B2380 (manufactured by Tokyo Chemical Industry), BBI-102 (manufactured by Midori Chemical), WPI-113 (manufactured by Wako Pure Chemical Industries), and WPI-124 (manufactured by Wako Pure Chemical Industries). Industrial-made), WPI-169 (made by Wako Pure Chemical Industries), WPI-170 (made by Wako Pure Chemical Industries), DTBPI-PFBS (made by Toyo Gosei), Irgacure 290 (made by BASF) can be used.

As the component (E), only one type may be used, or two or more types may be used in combination.
The component (E) is 0.1 when the total content of the component (A), the component (B), and the component (C) of the low moisture-permeable hard coat layer forming composition is 100% by mass. It is preferable to add in the range of -10 mass%, and it is more preferable to add in the ratio of 0.5-5 mass%. When the addition amount is adjusted to the above range, it is preferable in view of stability of the curable composition, polymerization reactivity, and the like.

[Cellulose ester base material]
As a cellulose-ester base material in this invention, the well-known film, board, sheet | seat etc. which consist of cellulose esters can be used, and there is no limitation in particular. As the cellulose ester film, 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) or the like can be used.

  By using a cellulose ester base material, monomers such as an epoxy monomer penetrate into the cellulose ester base material, which is considered to improve the adhesion between layers. Among them, a cellulose acylate film having high transparency, optically low birefringence, easy production, and generally used as a protective film for a polarizing plate is preferable, and a cellulose triacetate film is more preferable. Moreover, the thickness of a base material shall be about 20 micrometers-about 1000 micrometers normally. In the present invention, it is particularly preferable that the substrate is a cellulose ester film and the film thickness of the cellulose ester film is 20 μm or more and 70 μm or less.

  The cellulose ester substrate preferably has higher transparency and preferably has a visible light transmittance of 80% or more.

In the present invention, it is preferable to use cellulose acetate having an acetylation degree of 59.0 to 61.5% as the cellulose acylate film.
The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose. The degree of acetylation follows the measurement and calculation of the degree of acetylation in ASTM: D-817-91 (test method for cellulose acetate and the like). The viscosity average degree of polymerization (DP) of cellulose acylate is preferably 250 or more, and more preferably 290 or more.
In addition, the cellulose acylate used in the present invention has a Mw / Mn (Mw is a weight average molecular weight, Mn is a number average molecular weight) value by gel permeation chromatography close to 1.0, in other words, a molecular weight distribution. Narrow is preferred. The specific value of Mw / Mn is preferably 1.0 to 1.7, more preferably 1.3 to 1.65, and most preferably 1.4 to 1.6. preferable.

In general, the 2, 3, and 6 hydroxyl groups of cellulose acylate are not evenly distributed by 1/3 of the total substitution degree, and the substitution degree of the 6-position hydroxyl group tends to be small. In the present invention, it is preferable that the substitution degree of the 6-position hydroxyl group of cellulose acylate is larger than that of the 2- and 3-positions. The hydroxyl group at the 6-position with respect to the total substitution degree is preferably substituted with 32% or more of an acyl group, more preferably 33% or more, and particularly preferably 34% or more. Furthermore, the substitution degree of the 6-position acyl group of cellulose acylate is preferably 0.88 or more. The 6-position hydroxyl group may be substituted with a propionyl group, butyroyl group, valeroyl group, benzoyl group, acryloyl group or the like, which is an acyl group having 3 or more carbon atoms, in addition to the acetyl group. The degree of substitution at each position can be determined by NMR.
In the present invention, as the cellulose acylate, paragraphs “0043” to “0044” [Example] [Synthesis Example 1], paragraphs “0048” to “0049” [Synthesis Example 2], and paragraph “ Cellulose acetate obtained by the method described in “0051” to “0052” [Synthesis Example 3] can be used.

<Average film thickness of low moisture permeability hard coat layer>
The average film thickness of the low moisture permeability hard coat layer in the low moisture permeability hard coat film of the present invention is preferably 5 μm or more.
When the average film thickness of the low moisture-permeable hard coat layer is 5 μm or more, sufficient hard coat properties can be obtained and moisture permeability can be lowered. Moreover, it is preferable that the average film thickness of a low moisture-permeable hard-coat layer is 30 micrometers or less, and by making it 30 micrometers or less, it is easy to dry in the application | coating and drying process to a base material, and obtains the outstanding brittleness. be able to. As for the average film thickness of a low moisture-permeable hard-coat layer, it is more preferable that it is 5-20 micrometers, and it is still more preferable that it is 5-15 micrometers.
In addition, the average film thickness of a low moisture-permeable hard-coat layer can be represented with the average value of the thickness of the normal line direction from a base material, observing the cross section of a low moisture-permeable hard-coat layer with a scanning electron microscope. In the present specification, “average film thickness” means a value obtained by measuring film thicknesses at five locations randomly by the above method and averaging the film thicknesses.

In the present specification, “low moisture permeability (low moisture permeability)” of the low moisture permeability hard coat film means that the moisture permeability of the low moisture permeability hard coat film is 40 ° C. according to the method of JIS Z-0208 (1976). In addition, it means 200 g / m ² / day or less after 24 hours at a relative humidity of 90%. Further, “low moisture permeability (low moisture permeability)” of the low moisture permeability hard coat layer means that a low moisture permeability hard coat layer is formed on a substrate having a moisture permeability of 500 g / m ² / day, When the moisture permeability of the moisture permeable hard coat film is evaluated in the same manner, it means that it is 200 g / m ² / day or less.
Further, “high hardness (high hardness)” of the low moisture-permeable hard coat film means that the pencil hardness of JIS K-5600-5-4 (1999) is 2H or more.

  The composition for forming a low moisture permeability hard coat layer may further contain a solvent, an inorganic filler, an ultraviolet absorber, and a surfactant as necessary. Hereinafter, each component will be described.

[solvent]
The composition for forming a low moisture-permeable hard coat layer can contain a solvent. As the solvent, various solvents can be used in consideration of the solubility of the monomer, the drying property during coating, the dispersibility of the translucent particles, and the like. Examples of such organic solvents include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole, phenetole, and dimethyl carbonate. , Methyl ethyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, acetic acid Propyl, methyl propionate, ethyl propionate, γ-ptyrolactone, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2 Methoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl alcohol such as methyl acetoacetate and ethyl acetoacetate, 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, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol , Hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene , Toluene, xylene and the like, and can be used alone or in combination of two or more.

Of the above solvents, it is preferable to use at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, acetone, cyclohexanone, toluene, and xylene.
Especially, it is preferable to use at least 1 sort (s) among methyl acetate, methyl ethyl ketone, acetone, and cyclohexanone from a viewpoint that it has the permeability | transmittance to a cellulose-ester base material.

  It is preferable to use a solvent so that the solid content in the composition for forming a low moisture-permeable hard coat layer is in the range of 20 to 80% by mass, more preferably 30 to 75% by mass, and still more preferably 40. -70 mass%.

[Inorganic filler]
In the present invention, it is preferable that the low moisture-permeable hard coat layer forming composition further contains an inorganic filler. It is preferable that the type and amount of the inorganic filler to be used be adjusted according to the required refractive index, film strength, film thickness, coatability, and the like.
The shape of the inorganic filler used in the present invention is not particularly limited, and for example, any of a spherical shape, a plate shape, a fiber shape, a rod shape, an indefinite shape, a hollow shape, and the like is preferably used. Further, the kind of the inorganic filler is not particularly limited, but an amorphous one is preferably used, and is preferably made of a metal oxide, nitride, sulfide or halide. Particularly preferred is silica. As metal atoms, Na, K, Mg, Ca, Ba, Al, Zn, Fe, Cu, Ti, Sn, In, W, Y, Sb, Mn, Ga, V, Nb, Ta, Ag, Si, B Bi, Mo, Ce, Cd, Be, Pb, Ni and the like. In order to obtain a transparent cured film, the average particle diameter of the inorganic filler is preferably set to a value within the range of 0.001 to 0.2 μm, more preferably 0.001 to 0.1 μm, and still more preferably. 0.001 to 0.06 μm. Here, the average particle diameter of the inorganic fine particles is observed with a transmission electron microscope, and can be calculated as an average of 100 particles.
Although the usage method of the inorganic filler in this invention is not restrict | limited in particular, For example, it can use in a dry state or can also be used in the state disperse | distributed to water or the organic solvent.

[Ultraviolet absorber]
Although the low moisture-permeable hard coat film of the present invention can be used for a polarizing plate or an image display device member, from the viewpoint of preventing deterioration of a polarizing plate, a liquid crystal cell, or the like, in the composition for a low moisture-permeable hard coat layer. By containing the ultraviolet absorber, it is possible to impart ultraviolet absorptivity to the low moisture permeability hard coat film.

  As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Only one type of ultraviolet absorber may be used, or two or more types may be used in combination. For example, the ultraviolet absorber as described in Unexamined-Japanese-Patent No. 2001-72782 and Special Table 2002-543265 is mentioned. Specific examples of the ultraviolet absorber include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, triazine compounds, and the like.

[Translucent resin particles]
The low moisture-permeable hard coat layer forming composition of the present invention may contain translucent resin particles. By including translucent particles in the composition for low moisture-permeable hard coat layer, it is possible to impart an uneven shape to the surface of the low moisture-permeable hard coat layer or to provide internal haze.
The average particle diameter of the translucent particles is preferably 3 μm to 12 μm, more preferably 4 μm to 11 μm, and most preferably 5 to 10 μm. In the present invention, the average particle size indicates the primary particle size.
It is also preferable to use two or more kinds of particles having different average particle diameters as means for adjusting the surface irregularity shape to a specific range.

The measuring method of the particle diameter of the translucent resin particles may be any measuring method as long as it is a measuring method for measuring the particle diameter of the particles. However, the particle size distribution of the particles is measured by the Coulter counter method, and the measured distribution is measured. Is calculated from the particle distribution obtained by converting to a particle number distribution, or the particles are observed with a transmission electron microscope (magnification of 500,000 to 2,000,000 times), and 100 particles are observed. There is a method of obtaining an average particle size.
In the present invention, the average particle diameter is a value obtained by the Coulter counter method.

  In order to make the surface irregularity shape in the antiglare layer of the present invention, the ratio of the film thickness of the antiglare layer to the average particle diameter of the light transmissive particles (film thickness of the antiglare layer / average particle diameter of the light transmissive particles) Is preferably 1.0 to 3.0, more preferably 1.3 to 2.7, and most preferably 1.5 to 2.5. When this ratio is 1.0 or more, the unevenness of the film surface does not become too large, which is excellent in terms of black tightening and point defects. On the other hand, if it is 3.0 or less, it is not necessary to add a large amount of particles in order to achieve the desired antiglare property, which is excellent in terms of the hardness of the film.

The uneven surface shape of the low moisture-permeable hard coat layer is preferably designed so that the arithmetic average roughness Ra is 0.01 to 0.25 μm, more preferably 0.01 to 0.20 μm, still more preferably 0.01 to 0.15 μm. When the Ra value is 0.01 μm or more, clear antiglare properties are obtained, while when the Ra value is 0.25 μm or less, high black tightening is exhibited.
The haze value in the low moisture-permeable hard coat layer of the present invention is preferably designed to be 0.5 to 5.0%, more preferably 1.5 to 4.5%, and 2.5% to 4 More preferably, it is made 0.0%. By designing the haze within this range, it is possible to achieve both excellent anti-glare properties and black tightening properties.

  The refractive index of the translucent resin particles was changed by changing the mixing ratio of two kinds of solvents having different refractive indexes selected from methylene iodide, 1,2-dibromopropane, and n-hexane. The turbidity is measured by dispersing an equal amount of translucent particles in a solvent, and the refractive index of the solvent when the turbidity is minimized is measured by an Abbe refractometer.

  The light-transmitting resin particles can impart internal scattering properties by controlling the difference in refractive index with the binder. However, since the contrast decreases when the internal scattering properties are large, the light-transmitting resin particles are excluded. It is preferable to design the difference between the refractive index of the antiglare layer to 0.010 or less, the refractive index difference between the translucent resin particles and the binder is 0.01 or less, preferably 0.005 or less, More preferably 0. By setting the difference in refractive index within this range, it is possible to substantially eliminate a decrease in contrast due to internal scattering.

  Specific examples of the translucent 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, and crosslinked acrylate-styrene copolymers. Examples thereof include resin particles such as particles, melamine / formaldehyde resin particles, and benzoguanamine / formaldehyde resin particles. Of these, crosslinked styrene particles, crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles and the like are preferable. Furthermore, the surface of these resin particles is surface-modified particles in which a compound containing fluorine atom, silicon atom, carboxyl group, hydroxyl group, amino group, sulfonic acid group, phosphoric acid group or the like is chemically bonded, or nano-sized such as silica or zirconia. Examples of the particles include inorganic fine particles bonded to the surface.

  The translucent resin particles used in the present invention may be one type or two or more types. The content of the translucent resin particles is 0.5 to 12% by mass with respect to the total solid content in the composition for low moisture permeability hard coat layer, from the viewpoint of imparting antiglare properties and high blackness. Preferably, 1-10 mass% is more preferable, and 2-8 mass% is still more preferable.

In the low moisture-permeable hard coat film of the present invention, the low moisture-permeable hard coat layer is prepared by irradiating ultraviolet light after applying the composition for low moisture-permeable hard coat layer on the cellulose ester substrate. Preferably there is. Under the present circumstances, it is preferable that the illumination intensity of an ultraviolet-ray is 10-5000mW / cm < ² >, and it is preferable that an irradiation amount is 10-10000mJ / cm < ² >.

  Moreover, it is preferable that a low moisture-permeable hard-coat layer irradiates an ultraviolet-ray in the state which set the cellulose-ester base material which apply | coated the composition for low moisture-permeable hard-coat layers to 10-90 degreeC, The state set to 30-90 degreeC It is more preferable to irradiate with ultraviolet rays. By setting the temperature within this range, the polymerizability can be increased. You may heat in order to make it in this temperature range. The temperature can be measured with PT-2LD manufactured by OPTEX.

  Furthermore, the low moisture permeability hard coat layer in the present invention can be heated after being irradiated with ultraviolet rays, but from the viewpoint of complexity of the process and suppression of damage to the substrate and other layers, after irradiation with ultraviolet rays. It is preferable that it is produced without heating.

[Functional layer]
The low moisture-permeable hard coat 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 having a refractive index adjusted such as a low refractive index layer, a medium refractive index layer, a high refractive index layer), an antiglare layer, an antistatic layer, an ultraviolet absorbing layer, or the like Is mentioned.
The functional layer may be a single layer or a plurality of layers. The method for laminating the functional layers is not particularly limited.
The functional layer may be laminated on the surface on which the low moisture-permeable hard coat layer of the present invention is not laminated.

{Antireflection layer}
In the present invention, an antireflection layer may be laminated on the low moisture permeability hard coat layer. As the antireflection layer, a known layer can be preferably used. Among them, a UV curable antireflection layer is preferable.
As the antireflection layer, for example, those described in JP-A-2013-254183, [0100] to [0146] can be applied, but the present invention is not limited thereto.

[Layer structure of low moisture permeability hard coat film]
The low moisture-permeable hard coat film of the present invention is obtained by forming a low moisture-permeable hard coat layer on a cellulose ester base material. Another layer may be interposed between the base material and the low moisture-permeable hard coat layer.
Examples of preferred layer configurations of the low moisture permeability hard coat film of the present invention are shown below, but are not particularly limited to these layer configurations.

-Cellulose ester substrate / low moisture permeability hard coat layer- Cellulose ester substrate / low moisture permeability hard coat layer / antireflection layer- Cellulose ester substrate / UV absorbing layer / low moisture permeability hard coat layer- Cellulose ester substrate / UV absorbing layer / low moisture permeability hard coat layer / antireflection layer / cellulose ester substrate / low moisture permeability hard coat layer / antiglare layer / cellulose ester substrate / low moisture permeability hard coat layer / antiglare layer / antireflection layer

{Optically anisotropic layer}
The low moisture-permeable hard coat 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 the plane, and the direction of the slow axis and the magnitude of the retardation are different from each other. It may be an optically anisotropic layer having a pattern in which retardation regions are regularly arranged in a plane.
In the present invention, the optically anisotropic layer is preferably formed on the other surface of the above-described base material on which the above-mentioned low moisture-permeable hard coat layer is formed.
On the other hand, when the low moisture-permeable hard coat layer is laminated on the same side as the optically anisotropic layer with respect to the substrate, the low moisture-permeable hardcoat layer is laminated between the substrate and the optically anisotropic layer. Alternatively, the base material, the optically anisotropic layer, and the low moisture-permeable hard coat layer may be laminated in this order.

  A preferred example having an optically anisotropic layer formed uniformly in the plane is an embodiment in which the optically anisotropic layer is a λ / 4 film, and is particularly useful as a member of an active 3D liquid crystal display device. The optically anisotropic layer of λ / 4 film and the hard coat layer are described in JP 2012-098721 A and JP 2012-127882 A as a mode in which they are laminated on the opposite surface via a substrate. Such an embodiment can be preferably used in the low moisture-permeable hard coat film of the present invention.

On the other hand, as a preferable example of the optically anisotropic layer on which the pattern is formed, there is a pattern type λ / 4 film, and the mode described in Japanese Patent Nos. 4825934 and 4887463 is the low moisture permeability of the present invention. It can be preferably used in a hard coat film.
Moreover, the aspect which combined the photo-alignment film and pattern exposure which were described in the Japanese translations of PCT publication No. 2012-517024 gazette (WO2010 / 090429 gazette) can also be used preferably with the low moisture-permeable hard coat film of this invention.
As will be described later, when producing a polarizing plate including the low moisture-permeable hard coat film of the present invention, the low moisture-permeable hard coat film of the present invention is provided on one surface of the polarizer, and the other of the polarizers is provided. An optical compensation film having optical anisotropy on the surface may be provided.

[Method for producing low moisture-permeable hard coat film]
The low moisture-permeable hard coat film of the present invention is produced by applying a composition for a low moisture-permeable hard coat layer on a cellulose ester base material, drying it, and then irradiating with ultraviolet rays to cure the applied layer. be able to. In the case of a protective film having another functional layer, the functional layer can be formed by a general method. In the step of irradiating ultraviolet rays, the effect is obtained by heating the cellulose ester substrate at a temperature of 10 ° C. to 90 ° C. with the illuminance of the ultraviolet rays being 10 to 5000 mW / cm ² and the irradiation amount being 10 to 10000 mJ / cm ^2. The reaction of the epoxy group can be advanced. On the other hand, if desired performance can be obtained after ultraviolet irradiation, it is preferable not to heat after ultraviolet irradiation in order to prevent damage to the substrate or other layers.

〔Polarizer〕
The polarizing plate of this invention contains a polarizer and the low moisture-permeable hard coat film of this invention provided as a protective film in the at least one surface of this polarizer.
The polarizing plate of the present invention includes a polarizer, a low moisture-permeable hard coat film of the present invention provided as a protective film on one surface of the polarizer, and an optical provided on the other surface of the polarizer. And an optical compensation film having anisotropy. The optical compensation film in this case can be the same as the optically anisotropic layer.
In the present invention, a method for manufacturing the polarizing plate is not particularly limited, and the polarizing plate can be manufactured by a general method. There is a method in which the obtained low moisture-permeable hard coat film is treated with an alkali and bonded to both surfaces of a polarizer prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. Instead of alkali treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed. Moreover, you may perform the above surface treatments. The bonding surface of the low moisture-permeable hard coat film with the polarizer may be a surface on which a low moisture-permeable hard coat layer is laminated, or may be a surface on which a low moisture-permeable hard coat layer is not laminated.

Examples of the adhesive used to bond the protective film treated surface and the polarizer include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latexes such as butyl acrylate, and the like.
The polarizing plate is composed of a polarizer and a protective film for protecting both surfaces of the polarizer. Further, the polarizing plate is composed of a protective film on one surface and a separate film on the other surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the contact bonding layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.

[Image display device]
The image display device of the present invention includes a liquid crystal cell and the polarizing plate of the present invention disposed in at least one of the liquid crystal cells, and the low moisture-permeable hard coat film of the present invention contained in the polarizing plate displays an image. It is arranged on the surface. Examples of the image display device include a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), and a cathode ray tube display device (CRT). It is preferable to use it for an apparatus.

<Configuration of general liquid crystal display device>
The liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing plates disposed on both sides of the liquid crystal cell, and, if necessary, at least between the liquid crystal cell and the polarizing plate. It has a configuration in which one optical compensation film is arranged.
The liquid crystal layer of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate. The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.

In a liquid crystal display device, a substrate including a liquid crystal cell is usually disposed between two polarizing plates, but the protective film for polarizing plates of the present invention can be used as any protective film of two polarizing plates. However, it is preferable that it is used as a protective film arrange | positioned on the outer side of a liquid crystal cell with respect to a polarizer among two protective films of each polarizing plate.
Of the two polarizing plates, it is particularly preferable to dispose the low moisture-permeable hard coat film of the present invention as a protective film on the viewing side of the viewing side polarizing plate.
Moreover, after arranging the low moisture-permeable hard-coat film of this invention as a protective film of the visual recognition side polarizing plate among two polarizing plates, it is further used as the backlight side protective film of the backlight side polarizing plate. It is also a preferred embodiment that the low moisture-permeable hard coat film of the present invention is disposed to suppress the expansion and contraction of the polarizer contained in the two polarizing plates and prevent the panel from warping.

<Types of liquid crystal display devices>
The low moisture-permeable hard coat film of the present invention can be used for liquid crystal cells in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-Ferroly Liquid Liquid Crystal), OCB (Optically QuantNW). Various display modes such as ECB (Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The low moisture-permeable hard coat film of the present invention is effective in any display mode liquid crystal display device. Further, it is effective in any of a transmissive type, a reflective type, and a transflective liquid crystal display device.

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited to these examples.

<Preparation of sample>
[Sample 1]
(Preparation of composition for forming hard coat layer)
Each component was mixed with the following composition, and it filtered with the polypropylene filter with the hole diameter of 5 micrometers, and prepared the composition for solid-coat layer formation (solid content concentration of 40 mass%).
A9550W 37.39 parts by mass Irgacure 184 (component (D)) 2.39 parts by mass Irgacure 290 (component (E)) 0 parts by mass Fluoroaliphatic group-containing copolymer (a)
(Solid content 40% by mass MEK diluent) 0.02 parts by mass MEK (methyl ethyl ketone) 17.99 parts by mass MiBK (methyl isobutyl ketone) 42.00 parts by mass

(Coating of hard coat layer)
As a base film, Fujitac TD60 (manufactured by Fuji Film Co., Ltd., width 1,340 mm, thickness 60 μm) is unwound from the roll form, and the above composition is used, as described in Example 1 of JP 2006-122889 A The coating was carried out by a die coating method using a slot die under the condition of a conveyance speed of 30 m / min, and the temperature of the substrate was adjusted to 60 ° C. and dried for 150 seconds by adjusting the temperature in the coating equipment. The temperature was measured with PT-2LD manufactured by OPTEX. Thereafter, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with an oxygen concentration of about 0.1% by volume under a nitrogen purge and a base material temperature of 25 ° C., a illuminance of 400 mW / cm ² , The coating layer was cured by irradiating ultraviolet rays with an irradiation amount of 300 mJ / cm ² and wound up. The coating amount was adjusted so that the thickness of the hard coat layer was 10 μm. The obtained hard coat film was designated as Sample 1.

[Samples 2 to 24]
Next, in the same manner as in sample 1, as shown in Table 1 below, the types and content ratios of components (A) to (C) in the composition, and the contents of components (D) to (E) In the same manner as in Sample 1, a composition having a solid content concentration of 40% by mass and a total content of components (A) to (C) based on the total solid content of 93.5% by mass was produced. In addition, the numerical value of (A)-(C) component in Table 1 is each ratio (mass%) when the sum total of (A)-(C) component is 100 mass%, and it is in coating composition. The total amount of the components (A) to (C) occupied was the same as the amount of A9550W in Sample 1. Content of (D)-(E) component is a ratio (mass%) when the total content of (A)-(C) component is 100 mass%. In addition, in the sample 24, 4 parts by mass of the translucent resin particles are added, and 4 parts by mass of the total amount of each component is translucent so as not to change the content ratio of the components (A) to (C). It was produced by replacing with resin particles.
Thereafter, in the same manner as in Sample 1, a coating film was coated on the substrate with the film thickness shown in Table 1 below, and Samples 2 to 24 were obtained.

The materials used are shown below.
A9550W: Dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical)
A-TMM-3: Pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical)
A-DCP: Tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical)

CEL2021P: Compound having the following structure (manufactured by Daicel)

TTA22: Compound having the following structure (manufactured by Tetrachem)

jER YL6810: Compound having the following structure (manufactured by Mitsubishi Chemical)

Cyclomer M100: Compound having the following structure (manufactured by Daicel)

Cyclomer A400: Compound having the following structure (manufactured by Daicel)

CEL8000: Compound having the following structure (manufactured by Daicel)

CEL2081: Compound having the following structure (manufactured by Daicel)

TTA27: Compound having the following structure (manufactured by Tetrachem)

Irgacure 184: 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF)
Irgacure 290: 1-hydroxy-cyclohexyl-phenyl-ketone cationic initiator (manufactured by BASF)
Translucent resin particles: cross-linked acrylic-styrene particles having an average particle size of 6 μm and a refractive index of 1.525 (manufactured by Sekisui Plastics)

<Evaluation>
The film thickness was measured about the produced samples 1-24, and the following physical-property measurement and evaluation were performed. The results are shown in Table 1 and FIG. FIG. 2 is a state diagram showing the content ratio of the ternary system of Samples 1 to 13, in which Examples are indicated by ◯ and Comparative Examples are indicated by △. Also, the numbers written beside each point correspond to the sample number.

(1) Moisture permeability (moisture permeability at 40 ° C and 90% relative humidity)
The samples of each Example and Comparative Example cut out to 70 mmφ were conditioned at 40 ° C. and 90% relative humidity for 24 hours, respectively, and measured by the method described in JIS Z-0208 (1976).

(2) Pencil Hardness Evaluation Pencil hardness evaluation described in JIS K-5600-5-4 (1999) was performed as an index of scratch resistance. Each sample was conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60% RH, and then using a 2B to 3H test pencil specified in JIS S 6006 (2013) at a load of 4.9 N, the following: Evaluation was performed as described above, and the highest hardness that was OK was taken as the evaluation value.
OK: No more than 4 scratches in the evaluation of n = 5 NG: No more than 3 scratches in the evaluation of n = 5

(3) Whitening under humid heat environment Each sample was allowed to stand for 24 hours at a temperature of 85 ° C. and a relative humidity of 85% RH, and the state of whitening of the sample after the standing was visually confirmed and judged according to the following criteria.
A: No whitening B: Whitening

  The film thickness of each of the produced samples of Examples and Comparative Examples was measured, and the following physical property measurement and evaluation were performed. The results are shown in Tables 1 and 2.

  As shown in Table 1 and FIG. 2, the low moisture permeability hard coat film of the present invention contains predetermined compounds (A) to (C) at a predetermined content ratio, and includes (B) component and (C) component. Since the molecular weight was also within the range of the present invention, the hardness was excellent, there was no whitening, and the moisture permeability was low.

Claims (10)

A low moisture-permeable hard coat film having a cellulose ester base material and a low moisture-permeable hard coat layer,
The low moisture-permeable hard coat layer is formed from a composition containing the following (A) to (E):
The content ratio of the following (A), (B), and (C) in the composition is (80, 10, 10), (10, 10, 80), ( 10, 50, 40), a low moisture-permeable hard coat film in a range surrounded by (40, 50, 10).
(A) a compound having 3 or more ethylenically unsaturated double bond groups in one molecule (B) a molecular weight of 270 or less, having 2 or more epoxy groups in one molecule, Compound in which at least one of them is an alicyclic epoxy group (C) The molecular weight is 300 or less, and it has one alicyclic epoxy group and one ethylenically unsaturated double bond group in one molecule. Compound (D) Radical polymerization initiator (E) Cationic polymerization initiator The low moisture-permeable hard coat film according to claim 1, wherein (B) is a compound represented by the following general formula (1).

In said general formula (1), R < ₁₁ >, R < ₁₂ >, R <_13> , R <_14> and R < ₁₅ > represent a hydrogen atom, a methyl group, or an ethyl group each independently.
X includes a single bond or an alkylene group that may have a substituent, an arylene group that may have a substituent, an aralkylene group that may have a substituent, an ester bond, an ether bond, or a heterocyclic ring. A (m + n) -valent linking group comprising a linking group or a combination thereof is represented.
m and n each independently represent an integer of 0 or more and 2 or less, and m + n ≧ 2.
When there are a plurality of R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ , the plurality of R ₁₁ , the plurality of R ₁₂ , the plurality of R ₁₃ , the plurality of R ₁₄ and the plurality of R ₁₅ are the same or different. It may be. The low moisture-permeable hard coat film according to claim 1 or 2, wherein (B) is a compound represented by the following general formula (2).

In said general formula (2), R <_16> , R <_17> , R <_18> and R < ₁₉ > represent a hydrogen atom, a methyl group, or an ethyl group each independently.
Y includes a single bond or an alkylene group that may have a substituent, an arylene group that may have a substituent, an aralkylene group that may have a substituent, an ester bond, an ether bond, and a heterocyclic ring. A divalent linking group comprising a linking group or a combination thereof is represented.   The low moisture-permeable hard coat film according to any one of claims 1 to 3, wherein (B) is 3 ', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate. The low moisture-permeable hard coat film according to any one of claims 1 to 4, wherein the (C) is a compound represented by the following general formula (3).

In the general formula (3), R represents a monocyclic hydrocarbon or a bridged hydrocarbon, L represents a single bond or a divalent linking group, and Q represents an ethylenically unsaturated double bond group.   Said (C) is epoxy cyclohexyl methyl (meth) acrylate, The low moisture-permeable hard-coat film as described in any one of Claims 1-5.   The low moisture-permeable hard coat film as described in any one of Claims 1-6 whose average film thickness of the said low moisture-permeable hard coat layer is 5 micrometers or more.   The polarizing plate containing a polarizer and the low moisture-permeable hard-coat film as described in any one of Claims 1-7 provided as a protective film in the at least one surface of the said polarizer.   A low moisture-permeable hard coat film according to any one of claims 1 to 7 provided as a protective film on one surface of the polarizer and the polarizer, and provided on the other surface of the polarizer. An optical compensation film having optical anisotropy.   An image display device comprising: a liquid crystal cell; and the polarizing plate according to claim 8 or 9 disposed on at least one surface of the liquid crystal cell, wherein the low moisture-permeable hard coat film is disposed on the image display surface side. .

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