JP2006251163A - Antireflection film, polarizing plate, and image display apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film having more favorable surface hardness even when the film thickness is decreased, and facilitating reduction of curls and low-cost manufacture, and to provide a high-quality polarizing plate and an image display apparatus equipped with the above antireflection film. <P>SOLUTION: The antireflection film comprises a cellulose ester film and at least a hard coat layer deposited on the film, wherein the cellulose ester film is formed by solvent casting film formation of a cellulose ester doped composition containing an ethylenically unsaturated monomer and/or an ethylenically unsaturated monomer having a functional group, and a photopolymerization initiator. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical film, an antireflection film, a polarizing plate using the same, and a liquid crystal display device.

  Anti-reflection films generally prevent contrast degradation and image reflection due to reflection of external light in image display devices such as cathode ray tube display devices (CRT), plasma display panels (PDP), and liquid crystal display devices (LCD). In order to do this, it is placed on the outermost surface of the display that reduces the reflectivity using the principle of optical interference.

  Anti-reflection film is installed to prevent contrast degradation and image reflection due to reflection of external light. Its principle is to reduce reflectivity using the principle of optical appreciation, and to form fine irregularities on the film surface. In addition, there are those that exhibit an anti-glare effect by irregularly reflecting external light, and combinations of the above two. Since the antireflection film is usually installed on the outermost surface of the image display device, the antireflection film often receives physical impact from the outside, and the strength of the surface is the most important of the antireflection film along with the antireflection performance. Is one of the important performances.

Therefore, in the antireflection film, a hard coat layer is installed in order to ensure surface hardness, and the support film is increased in hardness. Although it is preferable to make the hard coat layer as thin as possible from the viewpoint of cost, it is necessary to increase the thickness of the hard coat layer in order to improve the surface hardness. The curl of the later film becomes remarkable, and the handleability deteriorates.
In addition, as a support for an antireflection film for liquid crystal display devices, triacetyl cellulose is generally used, but the surface strength is low as it is, and it is very brittle and easy to tear, especially under low humidity conditions. was there. Therefore, in order to improve these, a technique for adding a polymerizable monomer in the dope and performing ionization irradiation before peeling to improve the film forming speed (US Pat. No. 3,738,924), the dope A technique for forming a film by adding a polymerizable monomer containing a UV-absorbing group and a photopolymerization initiator and irradiating with UV light in a casting process to form a film (for example, JP-A Nos. 2002-20410 and 2002-47357) Etc.) are known. However, even with these supports, film strength stability under long-term storage, film coloring, and the like were not sufficient.
In order to further reduce the thickness of the liquid crystal display device, the support on which the antireflection film is coated is preferably as thin as possible. However, the thinning of the base leads to a decrease in the surface hardness of the antireflection film. It was difficult to reduce the thickness.
U.S. Pat. No. 3,738,924 JP 2002-20410 A JP 2002-47357 A

As described above, there has been no proposal of an antireflection film that secures the problem of curling while ensuring a sufficient surface hardness, and has both surface hardness and thinning. Accordingly, the present invention has been made to solve the above-mentioned problems, and the first object of the present invention is to form an antireflection film on a cellulose ester film whose surface has been hardened, thereby forming a surface. An object of the present invention is to provide an antireflection film having a better hardness. In addition, the second object of the present invention is to form an antireflection film on a cellulose ester film whose surface is hardened, thereby reducing the thickness of the hard coat layer, reducing curl and reducing the cost of film formation. It is to plan. In addition, the third object of the present invention is to secure a surface hardness equivalent to that of a conventional antireflection film by forming an antireflection film on the cellulose ester film having a high hardness and a thin surface. It is to reduce the film thickness of the antireflection film.
Another object of the present invention is to provide a high-quality polarizing plate and an image display device provided with the antireflection film.

As a result of intensive studies to solve the above-described problems, the present inventors have found that the above-described problems can be solved and the object can be achieved, and the present invention has been completed.
That is, the present invention achieves the object by the following configuration.
(1) On a cellulose ester film formed by solution casting a cellulose ester dope composition containing an ethylenically unsaturated monomer and / or a functional group-containing ethylenically unsaturated monomer and a photopolymerization initiator And an antireflection film comprising at least a hard coat layer.
(2) Semi-IPN (semi-interpenetrating network structure) in which the cellulose ester film is a cellulose ester and a crosslinked polymer obtained by polymerizing the ethylenically unsaturated monomer and / or the ethylenically unsaturated monomer having a functional group. Item 2. The antireflection film according to Item 1, which has a type polymer alloy structure.
(3) The antireflection film as described in any one of (1) or (2), wherein the ethylenically unsaturated monomer is mainly a vinyl ester.
(4) The reflection according to any one of claims 1 to 3, wherein the cellulose ester dope composition contains an ethylenically unsaturated monomer having 2 to 3 ethylenically unsaturated groups. Prevention film.
(5) The antireflection film as described in any one of (1) to (4), wherein the functional group is an ultraviolet absorbing group and / or an antistatic group.
(6) A cellulose ester film formed by solution casting a cellulose ester dope composition containing a compound having an epoxy group and / or a compound having an epoxy group and an ultraviolet absorbing group and a photopolymerization initiator An antireflection film, comprising at least a hard coat layer laminated thereon.
(7) Semi-IPN (semi-interpenetrating network structure) in which the cellulose ester film is a cellulose ester and a crosslinked polymer obtained by polymerizing a compound having an epoxy group and / or a compound having an epoxy group and an ultraviolet absorbing group. Item 7. The antireflection film according to Item 6, which has a polymer alloy structure.
(8) The antireflection film as described in any one of Items 1 to 7, wherein the cellulose ester dope composition contains fine particles.
(9) The antireflection film as described in the item, wherein the fine particles comprise a compound containing silicon oxide having a methyl group on the surface.
(10) Contains a polymer obtained by polymerizing an ethylenically unsaturated monomer mainly composed of an ethylenically unsaturated monomer selected from vinyl esters and acrylic acid esters and / or a monomer selected from vinyl esters having functional groups and acrylic acid esters. An antireflection film comprising: a cellulose ester film formed by solution casting a cellulose ester dope composition; and a hard coat layer laminated at least.
(11) The cellulose ester film is an ethylene mainly composed of a cellulose ester and an ethylenically unsaturated monomer selected from the vinyl ester and acrylate ester and / or a monomer selected from a vinyl ester having a functional group and an acrylate ester. Item 11. The antireflection film according to Item 10, which has a semi-IPN (semi-interpenetrating network structure) type polymer alloy structure with a crosslinked polymer obtained by polymerizing a polymerizable unsaturated monomer.
(12) The antireflection film as described in item 10 or 11, wherein the functional group is an ultraviolet absorbing group and / or an antistatic group.
(13) The antireflection film as described in any one of Items 10 to 12, wherein the cellulose ester dope composition contains fine particles.
(14) The antireflection film as described in (13), wherein the fine particles comprise a compound containing silicon oxide having a methyl group on the surface.
(15) The antireflection film as described in any one of Items 1 to 14, wherein the hard coat layer has a thickness of 2 μm or more and 6 μm or less.
(16) The antireflection film as described in any one of Items 1 to 15, wherein the film thickness of the cellulose ester film is 40 μm or more and less than 80 μm.
(17) The antireflection film as described in any one of Items 1 to 16, wherein the hard coat layer has an antiglare property.
(18) The antireflection film according to any one of Items 1 to 17, wherein a low refractive index layer having a refractive index lower than that of the hard coat layer is coated on the hard coat layer. .
(19) The cellulose ester film is a cellulose ester film having a multilayer structure having at least a base layer and a surface layer, and a matting agent is added only to the surface layer. The antireflection film as described in 1.
(20) The antireflection film as described in Item 19, wherein the surface layer has a center line average roughness of 0.01 μm to 5 μm.
(21) The antireflection film according to item 19 or 20, wherein the surface layer has a center line average roughness of 0.1 μm to 1 μm.
(22) A cellulose ester film produced by using inorganic particles as a matting agent and casting a composition containing inorganic particles by a co-casting method to form a surface layer, Item 19 Item 22. The antireflection film according to any one of Items 21 to 21.
(23) Use of a cellulose ester film produced by casting inorganic particles as a matting agent and casting a composition containing inorganic particles by a sequential casting method to form a surface layer. Item 22. The antireflection film according to any one of Items 19 to 21.
(24) After the cellulose ester dope composition according to any one of Items 1 to 9 is cast onto an endless metal support that moves infinitely in a solution casting film forming apparatus, drying of the web is completed with a drying apparatus. In the meantime, a cellulose ester film produced by irradiating the web with ultraviolet rays is used.
(25) A cellulose ester film produced by irradiating with ultraviolet rays between casting and peeling to an endless metal support that infinitely transfers the cellulose ester dope composition, The antireflection film as described in 24.
(26) An antireflection film comprising a cellulose ester film produced by solution casting the cellulose ester dope composition according to any one of items 10 to 14.
(27) A polarizing plate using the antireflection film according to any one of items 1 to 26.
(28) The antireflection film of Item 1 to 26 is used as one protective film of the polarizing film, and the thickness direction retardation Rth of the protective film is 40 nm to −50 nm as the other protective film of the polarizing film. A polarizing plate characterized by the above.
(29) The antireflection film described in Items 1 to 26 is used as one protective film of the polarizing film, and an optical compensation film having optical anisotropy is used as the other protective film of the polarizing film. A characteristic polarizing plate.
(30) An image display device comprising the antireflection film according to item 1 to item 26 or the polarizing plate according to item 27 to item 29.

  With the antireflection film of the present invention, it was possible to provide an antireflection film having improved curl while sufficiently securing the surface hardness, and an antireflection film having both surface hardness and thinning. Furthermore, it was possible to provide a high-quality polarizing plate and an image display device provided with the antireflection film.

  Hereinafter, the present invention will be described in more detail. In the present 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”. . Moreover, in this specification, description with "(meth) acrylate" represents the meaning of "at least one of an acrylate and a methacrylate." The same applies to “(meth) acrylic acid” and the like.

[Layer structure of antireflection film]
FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of the antireflection film according to the present invention.
FIG. 1 shows an example of the structure of the antireflection film. The antireflection film has a layer structure in the order of a transparent support (1), a hard coat layer (2), a medium refractive index layer (3), a high refractive index layer (4), and a low refractive index layer (5). Have.

  Further, as shown in FIG. 2, when a hard coat layer (2) is applied on a transparent support (1) and a low refractive index layer (5) is laminated as a refractive index layer, it is suitable as an antireflection film. Can be used.

  Furthermore, as shown in FIG. 3, the high refractive index layer (4) and the low refractive index layer (5) may be laminated on the transparent support (1) after the hard coat layer (2) is applied. It can be suitably used as an antireflection film.

  The hard coat layer (2) may have antiglare properties. The antiglare property may be formed by dispersion of matte particles as shown in FIG. 4, or may be formed by surface shaping by a method such as embossing as shown in FIG.

[Explanation of materials for each layer]
[Base film (support)]
As the transparent support used for the antireflection film of the present invention, it is preferable to use a plastic film. Examples of plastic film materials include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, nitrocellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate). , Poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, Polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, polymethylmethene Tacrylate and polyether ketone are included. In particular, when the antireflection film of the present invention is used as one side of a surface protective film of a polarizing plate for use in a liquid crystal display device, an organic EL display device or the like, triacetyl cellulose is preferably used. As the triacetyl cellulose film, a known film such as TAC-TD80U (manufactured by Fuji Photo Film Co., Ltd.) or a film published in published technical report number 2001-1745 is preferably used. Further, the support film for the antireflection film is most preferably a cellulose acetate film having the structure described below.

  The manufacturing method of the cellulose-ester film by the solution casting film forming method concerning this invention is demonstrated.

  The cellulose ester according to the present invention has an acyl group substitution degree of 2.5 to 3.0, and the acyl group is at least one selected from an acetyl group, a propionyl group, and a butyryl group. Specific examples include cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose propionate, cellulose butyrate, cellulose acetate propionate butyrate, etc. In the present invention, cellulose triacetate, cellulose Acetate propionate, cellulose acetate butyrate, and cellulose acetate propionate butyrate are preferred. When an acetyl group is included, the substitution degree of the acetyl group is preferably 1.4 or more in order to maintain mechanical properties. Cellulose ester is not particularly limited as cellulose as a raw material, and cotton linter, wood pulp, kenaf and the like can be used. You may mix and use these. It is preferable to use a large amount of cellulose ester synthesized from a cotton linter that has good releasability from a belt or drum because of high production efficiency. The ratio of cellulose ester synthesized from cotton linter is 60% by mass or more, and since the effect of peelability becomes remarkable, 60% by mass or more is preferable, more preferably 85% by mass or more, and further, it can be used alone. Most preferred. The method for synthesizing the cellulose ester is not particularly limited. For example, the cellulose ester can be synthesized by the method described in JP-A-10-45804. The measuring method of the substitution degree of an acyl group can be measured by ASTM-D817-96. The number average molecular weight of the cellulose ester is preferably from 70,000 to 300,000, more preferably from 80,000 to 200,000, in order to obtain a preferable mechanical strength as a protective film for a polarizing plate.

  The cellulose ester dope of the present invention is essentially free from low molecular weight plasticizers, UV absorbers, antistatic agents, etc. that are conventionally used, and is photopolymerized in a cellulose ester dope or web containing a polymer. A dope composition containing a polymer to be formed is formed. Therefore, a feature of the present invention is that the plasticizer, ultraviolet absorber, antistatic agent, etc. do not precipitate or volatilize from the web. However, if it is a slight amount, it may be supplementarily added to such an extent that a low-molecular plasticizer, ultraviolet absorber, antistatic agent, etc. are not precipitated. The low molecular plasticizer that can be supplementarily added in the present invention is not particularly limited, but a phosphate ester plasticizer, a phthalate ester plasticizer, a glycolate plasticizer, and the like can be preferably used. Phosphate ester plasticizers such as triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc., phthalate ester plasticizers such as diethyl phthalate, dimethoxy Ethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, dibenzyl phthalate, glycolate plasticizers such as butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalate Ruethyl glycolate or the like can be preferably used. These plasticizers can be used alone or in admixture of two or more. In the present invention, the ultraviolet absorber that can be supplementarily added is not particularly limited, and examples thereof include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, and nickel complex salts. Although a compound etc. can be mentioned, A benzotriazole type compound with little coloring is preferable. Benzotriazole ultraviolet absorbers and benzophenone ultraviolet absorbers having stability against light are preferable, and benzotriazole ultraviolet absorbers with less unnecessary coloring are particularly preferable. For example, TINUVIN109 (UV-1), TINUVIN171, TINUVIN326, TINUVIN327, and TINUVIN328 manufactured by Ciba Specialty Chemicals Co., Ltd. can be preferably used, but low molecular weight UV absorbers are similar to plasticizers depending on the amount used. In addition, there is a possibility that it may be deposited on the web or volatilized during film formation, so the amount added is about 3 to 10% by mass.

  In the method for preparing a cellulose ester dope according to the present invention, a dope is formed by dissolving in an organic solvent (good solvent) that can dissolve the cellulose ester. The dough is formed by dissolving the flakes in an organic solvent mainly containing a good solvent for the flakes of cellulose ester in a dissolution vessel while stirring. For dissolution, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, JP-A-9-95544, 9-95557 or 9-95538 Various melting methods such as a method performed by a cooling dissolution method as described in JP-A No. 11-21379 and a method performed at a high pressure as described in JP-A No. 11-21379 can be used. After dissolution, the dope is filtered with a filter medium, defoamed, and sent to the next process with a pump. The concentration of the cellulose ester in the dope is preferably 10 to 35% by mass.

  In the present invention, good solvents for cellulose ester used in forming the dope composition include methyl acetate, ethyl acetate, amyl acetate, ethyl formate, acetone, cyclohexanone, methyl acetoacetate, tetrahydrofuran, 1,3-dioxolane, 1 , 4-dioxane, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3 3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane And methylene chloride. Of these, methyl acetate and ethylene chloride can be preferably used. In addition, it is preferable to use a lower alcohol such as methanol, ethanol or butanol in combination with these organic solvents because the solubility of the cellulose ester in the organic solvent can be improved and the dope viscosity can be reduced. In particular, ethanol having a low boiling point and low toxicity is preferred. In addition, the dope film is gelled after casting on a metal support by using 5 to 30% by mass of a poor solvent for the cellulose ester of lower alcohol or cyclohexane in an organic solvent capable of dissolving the cellulose ester. (Solidify), can be peeled off from the metal support quickly, and the film forming speed can be increased.

  There are roughly three cellulose ester dope compositions of the present invention. One of them is a cellulose ester dope composition containing an ethylenically unsaturated monomer and / or an ethylenically unsaturated monomer having a functional group and a photopolymerization initiator. The second is a cellulose ester dope composition containing a compound having an epoxy group and / or a compound having an epoxy group and a functional group and a photopolymerization initiator. The above two dope compositions can be cast on an endless metal support that moves indefinitely, and the web can be photopolymerized by ultraviolet irradiation immediately after casting until the end of drying to form a polymer in the web. It is a dope composition. Another dope composition comprises an ethylenically unsaturated monomer mainly composed of a monomer selected from vinyl esters and acrylate esters and / or an ethylenically unsaturated monomer selected from vinyl esters having a functional group and acrylate esters. It is a cellulose ester dope composition containing a polymer obtained by dissolving a previously polymerized polymer together with a cellulose ester in an organic solvent.

  The polymer used in the cellulose ester dope composition of the present invention, or the polymer formed by photopolymerization in the web, is unlikely to aggregate in the web or film or to be in a phase separation state such as a sea-island structure. Any cellulose ester film having mechanical properties or optical properties equal to or higher than those of the cellulose ester film can be used without limitation. The glass transition point (hereinafter sometimes referred to as Tg) of the polymer contained in the cellulose ester film of the present invention is preferably 50 ° C. or lower. Moreover, the polymer contained in the cellulose ester film of the present invention is highly compatible with the cellulose ester, and is preferably one that exhibits water resistance, moisture permeability resistance, etc. with respect to the cellulose ester film. The polymer useful in the present invention has a number average molecular weight of 1,000 to 300,000, preferably 1500 to 250,000, more preferably 2000 to 100,000, and preferably has a molecular weight range in which the smaller molecular weight is less likely to bleed out. .

  In the first invention, the cellulose ester dope composition contains an ethylenically unsaturated monomer and / or an ethylenically unsaturated monomer having a functional group and a photopolymerization initiator. After casting, an ethylenically unsaturated monomer and / or an ethylenically unsaturated monomer having a functional group is photopolymerized to form a polymer, and water resistance can be imparted to the cellulose ester film from which the polymer is formed. . Examples of the ethylenically unsaturated monomer forming the photopolymerizable polymer useful in the present invention include vinyl acetates, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valerate, vinyl pivalate, caproic acid. Vinyl, vinyl enanthate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl cyclohexanecarboxylate, vinyl sorbate, vinyl benzoate, acrylic esters or methacrylic acid As acid esters (hereinafter, acrylic acid esters or methacrylic acid esters may be abbreviated as (meth) acrylic acid esters), methyl (meth) acrylate, ethyl acrylate, n-butyl ( Meta) Relate, heptyl (meth) acrylate, 2-methylbutyl (meth) acrylate, 3-methylbutyl (meth) acrylate, hexyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2- Ethoxyethyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) Acrylate, isomyristyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, ε-caprolactone (meth) acrylate, benzyl (meth) acrylate As vinyl ethers such as acrylate, phenethyl (meth) acrylate, 4-cyanobutyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, etc. Examples of styrenes include styrene, 4-[(2-butoxyethoxy) methyl] styrene, 4-butoxymethoxystyrene, 4-butylstyrene, 4-decylstyrene, 4- (2-ethoxymethyl) styrene, 4- (1- Ethylhexyloxymethyl) styrene, 4-hydroxymethylstyrene, 4-hexylstyrene, 4-nonylstyrene, 4-octyloxymethylstyrene, 2-octylstyrene, 4-octyl Tylene, 4-propoxymethylstyrene, and maleic acids such as dimethylmaleic acid, diethylmaleic acid, dipropylmaleic acid, dibutylmaleic acid, dicyclohexylmaleic acid, di-2-ethylhexylmaleic acid, dinonylmaleic acid, dibenzylmaleic acid However, it is not limited to these.

  In addition to the above monomers, ethylene, propylene, butadiene, 1-butylene, acrylonitrile, N-vinylpyrrolidone, maleic anhydride, acrylic acid, vinyl monomers other than the above, vinyl chloride, ethylene, propylene, (meth) acrylonitrile, N-vinylpyrrolidone, (meth) acrylic acid, maleic anhydride, crotonic acid, itaconic acid and the like may be formed with the above monomer and copolymer at 10% by mass or less. Among these monomers, those having a Tg of the homopolymer of 50 ° C. or less can impart plasticity to the cellulose ester, but in the case of a monomer that forms a homopolymer having a Tg higher than that, the Tg of the copolymer The copolymer may be formed by selecting a comonomer so that the temperature is 50 ° C. or lower. Moreover, it is preferable to form a copolymer at an arbitrary ratio even with a monomer having a Tg or less.

  The Tg of the polymer can be measured by various methods, but POLYMER HANDBOOK (THIRD EDITION) J. Mol. BRANDRUOP & E. H. It can be known from the Tg of homopolymers published on page VI-209 of IMMERGUT editing (issued by JHON WILEY & Sons). Edited by BRANDRUOP et al., POLYMER HANDBOOK (1966) pages III-139 to 179 (issued by JHON WILEY & SONS). The Tg (expressed in ° K) of the copolymer can also be determined by the following formula.

Tg (copolymer) = v ₁ Tg ₁ + v in _{2 Tg 2 + ...... + v n} Tg n _{-type, v 1, v 2 ...... v} n represents the mass fraction of each monomer in the copolymer, Tg _1, Tg ₂ ...... Tg _n represents the Tg of the homopolymer of each monomer in the copolymer.

  More preferable monomers in the present invention are vinyl esters, and specifically, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valeric acid, vinyl pivalate, caproic acid. Vinyl, vinyl enanthate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl cyclohexanecarboxylate, vinyl sorbate, and other methyl acrylate, ethyl acrylate Propyl acrylate, dimethylmaleic acid, diethylmaleic acid, propylmaleic acid and butylmaleic acid are also preferred monomers. The main reason for the ethylenically unsaturated monomer selected from the vinyl ester and the acrylate ester in the constitution (8) of the present invention is that the vinyl ester and / or the acrylate ester is 40 mass in the total ethylenically unsaturated monomer. % Is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more. In addition to the above, the vinyl ester herein includes the following UV-absorbing group or vinyl ester and / or acrylate ester having the following antistatic group.

  The ethylenically unsaturated monomer having a functional group useful in the present invention is preferably one having an ultraviolet absorbing group or an antistatic group in the side chain of the polymer. Any copolymer can be used as long as it has a Tg of 50 ° C. or lower. The ethylenic group of the ethylenically unsaturated monomer having a functional group is preferably a vinyl group, an acryloyl group or a methacryloyl group, and these are preferably used.

  Examples of the ultraviolet absorbing group of the ethylenically unsaturated monomer having an ultraviolet absorbing group useful in the present invention include a benzotriazole group, a salicylic acid ester group, a benzophenone group, an oxybenzophenone group, and a cyanoacrylate group. Any of them can be preferably used in the invention. In particular, a monomer having a benzotriazole group with little photoreactivity and almost no coloring is preferred.

  Examples of the ethylenically unsaturated monomer having an ultraviolet absorbing group useful in the present invention are shown below. In addition, in the present invention, an ultraviolet absorbing monomer constituting the ultraviolet absorbing polymer described in JP-A-6-148430 can also be preferably used.

  In the present invention, a commercially available ethylenically unsaturated monomer having an ultraviolet absorbing group may be used, or may be obtained by synthesis. As a commercially available product, for example, the UVM-1 is 1-hydroxy-2- (2-benzotriazole) -4- (2-methacryloyloxyethyl) benzene, and a reactive ultraviolet absorber RUVA manufactured by Otsuka Chemical Co., Ltd. Commercially available as -93. Similarly, 1-hydroxy-2- (2-benzotriazole) -4- (2-acryloyloxyethyl) benzene can be preferably used in the present invention.

Synthesis examples of ethylenically unsaturated monomers having an ultraviolet absorbing group useful in the present invention are shown below.
Synthesis Example (Synthesis of UVM-1) 15.5 Hydroxy-2- (2-benzotriazole) -4- (2-hydroxyethyl) benzene (Compound A) 25.5 g (0.1 mol) and 17 ml of pyridine in 800 ml of toluene (0.21 mol) was added, and 13 ml (0.128 mol) of methacryloyl chloride dissolved in 10 ml of toluene was added dropwise over about 30 minutes. After stirring at room temperature for about 1 hour, water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was recrystallized from a mixed solvent of methanol and methylene chloride to obtain 22.3 g of UVM-1. The structure of the target product was confirmed by ¹ H-NMR and IR.

(Synthesis of UVM-6) 28.3 g (0.1 mol) of 1-hydroxy-2- (2-benzotriazole) -4- (2-hydroxycarbonylethyl) benzene (compound B) and dimethylformamide in toluene. 2 ml was added. Next, 13.0 ml (0.15 mol) of oxalyl chloride was added dropwise at room temperature. After stirring for about 1 hour, concentration under reduced pressure was performed to obtain a white solid. This white solid was dissolved in 8.9 ml (0.11 mol) of pyridine and 200 ml of tetrahydrofuran, and 18.0 g (0.11 mol) of 4-hydroxybenzoic acid vinyl ester dissolved in 50 ml of tetrahydrofuran was added dropwise over about 30 minutes. did. After stirring for about 1 hour, water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure and purified by silica gel chromatography to obtain 21.8 g of UVM-6. The structure of the target product was confirmed by ¹ H-NMR and IR.

  The ratio of the monomer unit having an ultraviolet absorbing group constituting the photopolymerized polymer in the present invention is such that the compatibility of the polymer with the cellulose ester, the mechanical property or physical property of the cellulose ester film is equal to or higher than the property, Alternatively, any material may be used as long as it has sufficient ultraviolet absorption performance (it may be in the range of 1 to 100% by mass), and it may be a homopolymer or a copolymer.

  Examples of the antistatic group of the ethylenically unsaturated monomer having an antistatic group useful in the present invention include a quaternary ammonium group, a sulfonate group, and a polyethylene oxide group. A quaternary ammonium group is preferable from the viewpoint of performance.

  Examples of the ethylenically unsaturated monomer having an antistatic group useful in the present invention are shown below.

The synthesis example of the ethylenically unsaturated monomer which has an antistatic group useful for this invention is illustrated below.
Synthesis Example (Synthesis of ASM-1) In a sealed tube, 50 ml of toluene, 14.2 ml (0.1 mol) of 4-vinylbenzylyl chloride, 9.0 ml (0.1 mol) of trimethylamine, and 1.7 g of t-butylcatechol (0 0.01 mol) and heated at about 70 ° C. for 48 hours. The solid was filtered off and washed with acetone to give 12.1 g of ASM-1. The structure of the target product was confirmed by ¹ H-NMR and IR.
(Synthesis of ASM-2) 50 ml of toluene, 11.2 g (0.1 mol) of triethylenediamine (DABCO) and 7.2 ml (0.1 mol) of ethyl chloride were placed in a sealed tube and heated at about 70 ° C. for 72 hours. The solid was filtered and washed with ethyl ether to obtain N-ethyltriethylenediamine monoammonium chloride (Compound C). In 50 ml of ethanol, 7.1 ml (0.05 mol) of 4-vinylbenzyl chloride, 10.6 g (0.05 mol) of compound C and 0.9 g (0.005 mol) of t-butylcatechol were added and refluxed with heating for 48 hours. The solid was filtered and washed with acetone to obtain 7.3 g of ASM-2. The target structure was confirmed by ¹ H-NMR and IR.
(Synthesis of ASM-4) 6.7 ml (0.1 mol) of 2-chloroethanol and 8.9 ml (0.2 mol) of pyridine were added to 200 ml of tetrahydrofuran, and 10.7 ml (0 of methacryl chloride dissolved in 50 ml of tetrahydrofuran was added thereto. .11 mol) was added dropwise over about 30 minutes. After stirring at room temperature for about 1 hour, water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. After filtration and drying with anhydrous sodium sulfate, concentration under reduced pressure was performed to obtain 2-chloroethyl methacrylate. On the other hand, 11.2 g (0.1 mol) of DABCO and 11.5 ml (10.1 mol) of benzyl chloride were added to 100 ml of ethanol and refluxed for 24 hours. The solid was filtered and washed with acetone to obtain N-ethyl-DABCO.monoammonium chloride (Compound D). In ethanol, 11.9 g (0.05 mol) of compound D, 7.4 g (0.05 mol) of 2-chloroethyl methacrylate, and 0.9 g (0.005 mol) of t-butylcatechol were added and heated to reflux for 48 hours. The solid was filtered and washed with acetone to give ASM-4 as 10.5. The structure of the target product was confirmed by ¹ H-NMR and IR.

  The ratio of the ethylenically unsaturated monomer having an antistatic group to the polymer obtained by photopolymerization in the present invention is 40% by mass or less from the water absorption, durability, plasticity, necessary antistatic properties, etc. of the cellulose ester film. It is preferably 5 to 30% by mass.

  The photopolymerization initiator useful in the present invention can be used without limitation as long as the ethylenically unsaturated monomer is an initiator that can be photopolymerized in the web, but known photopolymerization initiators can be used. . Photosensitizers can also be used. Specifically, benzoin methyl ether, benzoin-n-propyl ether, benzoin-n-butyl ether, benzoin silyl ether, methyl benzoin formate, benzyl, benzophenone, hydroxybenzophenone, p-methylbenzophenone, α-hydroxyisobutylphenone, p -Isopropyl-α-hydroxyisobutylphenone, acetophenone, Michler's ketone, α, α'-dichloro-4-phenoxyacetophenone, 1-hydroxy-1-cyclohexylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, diacetyl, eosin, thionine 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropene, dichlorothioxanthone, diisopropylthioxanthone, pheny Disulfide-2-nitrosofluorene, butyroin, anisoin ethyl ether, di-t-butyl peroxide, benzoylthiazolyl sulfide, α-amyloxime ester, azobisisobutyronitrile, tetramethylthiuram disulfide, etc. I can do it. In the present invention, a photopolymerization initiator is mixed with the ethylenically unsaturated monomer in the cellulose ester dope composition. The ethylenically unsaturated monomer is 5 to 30% by mass with respect to the cellulose ester, and the photopolymerization initiator is ethylene. It is good to add about 1-30 mass% with respect to a polyunsaturated monomer. In the present invention, after the photopolymerizable ethylenically unsaturated monomer is distributed in the cellulose ester dope composition, photopolymerization can be caused in the web containing a large amount of organic solvent or in the web even if the drying is considerably advanced. Although it is possible, it is preferable to polymerize by irradiating with ultraviolet rays on a metal support.

  By incorporating a crosslinkable monomer having two ethylenically unsaturated groups into the cellulose ester dope composition containing the ethylenically unsaturated monomer and the photopolymerization initiator of the present invention, it has both flexibility and toughness after photopolymerization. A cellulose ester film can be obtained. Examples of the crosslinkable monomer having two ethylenically unsaturated groups include polyester di (meth) acrylate and polyurethane di (meth) acrylate. A commercially available product is urethane acrylate (trade name, M-1310) manufactured by Toa Gosei Co., Ltd., which can be preferably used. Examples of these compounds are given below.

  These polyester or polyurethane di (meth) acrylates have a number average molecular weight of 6000 to 100,000, preferably 1000 to 80,000. Here, n is the number of repeating units.

  In the second present invention, the cellulose ester dope composition contains a compound having an epoxy group and a photopolymerization initiator. Similar to the above-described invention, these epoxy group-containing compounds can also be photopolymerized in the web, and plasticity can be imparted to the finished film. As the compound having an epoxy group, those which can be usually used for an adhesive or the like can be used. Examples of compounds having an epoxy group useful in the present invention include, as aromatic epoxy compounds (polyglycidyl ethers of polyhydric phenols), hydrogenated bisphenol A or glycidyl ethers of bisphenol A and epichlorohydrin, and epoxy novolac resins. (For example, cresol novolac polyglycidyl ether, phenol novolac polyglycidyl ether), resole epoxy resin, resorcinol diglycidyl ether, etc., as aliphatic epoxy resin, polyglycidyl ether of aliphatic polyhydric alcohol or its alkylene oxide adduct, fat There are polyglycidyl esters of group long-chain polybasic acids, homopolymers and copolymers of glycidyl acrylate and glycidyl methacrylate. Lenglycol diglycidyl ether, propylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol glycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, Nonapropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerin triglycidyl ether, diglycerol triglycidyl ether, diglycerol tetraglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, pentaerythritol tetraglycidyl ether, Sorbitol polyglycidyl Ether, cycloaliphatic epoxy compounds such as 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3', 4 ' -Epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene dioxide, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6- Methylcyclohexyl-3 ', 4'-epoxy-6-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane) dicyclopentadiene diepoxide, di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylene Bis (3,4-epoxycyclohexanecarboxylate), dicyclopentadiene diepoxide, diglycidyl ether of tris (2-hydroxyethyl) isocyanurate, triglycidyl ether of tris (2-hydroxyethyl) isocyanurate, polyglycidyl acrylate, Polyglycidyl methacrylate, glycidyl acrylate or copolymer of glycidyl methacrylate and other monomers, poly-2-glycidyloxyethyl acrylate, poly-2-glycidyloxyethyl methacrylate, 2-glycidyloxyethyl acrylate, 2-glycidyloxyethyl acrylate Or a copolymer of 2-glycidyloxyethyl methacrylate and another monomer, bis-2,2-hydroxycyclohexylpropane di It can be mentioned glycidyl ether, and the like, can be used in combination of two or more. In this invention, it is not limited to said compound, The compound estimated from these is also included.

  Further, in the present invention, in addition to those having two or more epoxy groups in the molecule, monoepoxides can be blended and used according to desired performance.

  The compound having an ultraviolet-polymerizable epoxy group in the present invention forms a polymer, a crosslinked structure or a network structure not by radical polymerization but by cationic polymerization. Unlike radical polymerization, it is not affected by oxygen in the reaction system, so there is no induction period and the polymerization can be performed quickly.

  The compound having an epoxy group useful in the present invention undergoes an ionic polymerization reaction using a compound that releases a substance that initiates cationic polymerization upon irradiation with ultraviolet rays as a catalyst. A group of double salts of onium salts that release a Lewis acid is particularly preferred as the one that initiates cationic polymerization upon UV irradiation.

A typical example is a compound represented by the following general formula (I).
Formula (I)
[(R ¹ ) _a (R ² ) _b (R ³ ) _c (R ⁴ ) _d Z] ^{+ w} [MeX _{v + w} ] ^−w where cation is onium, Z is S, Se , Te, P, As, Sb, Bi, O, halogen (eg, I, Br, Cl), or N = N (diazo), and R ¹ _a , R ² _b , R ³ _c , and R ⁴ _d are the same Or an organic group that may be different. a, b, c, and d are each an integer of 0 to 3, and a + b + c + d is equal to the valence of Z. Me is a metal or metalloid which is a central atom of a halide complex, and B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc. X is halogen, w is the net charge of the halogenated complex ion, and v is the number of halogen atoms in the halogenated complex ion.

Specific examples of the anion [MeX _{v + w} ] ^-w of the general formula (I) include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ). , Hexafluoroarsenate (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ) and the like.

Furthermore, an anion of the general formula MX _n (OH) ^— can also be used. Other anions include perchlorate ion (ClO ₄ ⁻ ), trifluoromethyl sulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, and trinitrobenzene acid anion. An ion etc. can be mentioned.

  Among these onium salts, it is particularly effective to use an aromatic onium salt as a cationic polymerization initiator. Among them, aromatic haloniums described in JP-A-50-151996, JP-A-50-158680 and the like are particularly effective. Salt, VIA group aromatic onium salts described in JP-A-50-151997, 52-30899, 59-55420, 55-125105, JP-A-56-8428, 56- 149402, 57-192429, etc., oxosulfoxonium salts described in JP-B-49-17040, etc., aromatic diazonium salts described in US Pat. No. 4,139,655, etc. A thiopyrylium salt or the like is preferable. Moreover, an aluminum complex, a photodegradable silicon compound type | system | group polymerization initiator, etc. can be mentioned. The cationic polymerization initiator can be used in combination with a photosensitizer such as the benzophenone and derivatives thereof, the benzoin and derivatives thereof, and the thioxanthone and derivatives thereof. The sensitizer preferably has an absorption maximum from the near ultraviolet region to the visible light region.

  In the present invention, a photopolymerization initiator and / or a photosensitizer is mixed together with a compound having an epoxy group in a cellulose ester dope. A polymerization initiator is 1-30 mass% with respect to the compound which has an epoxy group, Preferably it is 1-10 mass%.

  A compound having an epoxy group and an ultraviolet absorber useful in the present invention may be mixed with a photopolymerization initiator to form a dope, or may be mixed with a compound having an epoxy group to form a dope.

  Examples of the ultraviolet absorbing group of the compound having an epoxy group and an ultraviolet absorbing group useful in the present invention include a benzotriazole group, a salicylic acid ester group, a benzophenone group, an oxybenzophenone group, and a cyanoacrylate group. Any of them can be preferably used. In particular, a benzotriazole group having low photoreactivity and almost no coloring is preferred.

  The compounds having an epoxy group and an ultraviolet absorbing group useful in the present invention are exemplified below.

  A cellulose ester dope containing a compound having an epoxy group and an ultraviolet absorbing group according to the present invention is formed in a solution casting film forming process, and an ultraviolet absorber is not deposited or volatilized from a web irradiated with ultraviolet rays. Therefore, it is possible to obtain a protective film for a polarizing plate for a liquid crystal image display device with good productivity and excellent quality. Further, the polymer of the compound having an epoxy group and an ultraviolet absorbing group preferably has water resistance with respect to the cellulose ester as described above, and the Tg of the polymer is preferably 50 ° C. or lower.

  The proportion of the compound unit having an ultraviolet absorbing group constituting the photopolymerized polymer in the present invention is such that the compatibility of the polymer with the cellulose ester, the mechanical property or physical property of the cellulose ester film is equal to or higher than the property, Or what kind of thing may be sufficient if it has sufficient ultraviolet-ray absorption performance (the range of 1-100 mass% may be sufficient).

In the present invention, a synthesis example of a compound having an ultraviolet absorbing group and an epoxy group is exemplified below.
Synthesis Example (Synthesis of UVE-1) 30.2 g (0.1 mol) of trimethylolpropane triglycidyl ether (Compound C), 12.8 g (0.05 mol) of Compound A and 0.24 g (2.5 mol) of tetramethylammonium chloride Was dissolved in 50 ml of toluene and heated to reflux for about 2 hours. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. This solution was dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel chromatography to obtain UVE-1. The structure of the target product was confirmed by ¹ H-NMR and IR.

  In the present invention, a photopolymerization initiator (in some cases, a photosensitizer) is mixed with a compound having an epoxy group in the cellulose ester dope, but the compound having an epoxy group is 5 to 30% by mass with respect to the cellulose ester. The photopolymerization initiator is 1 to 30% by mass, preferably 1 to 10% by mass, based on the compound having an epoxy group.

  Here, a method for forming the cellulose ester film of the present invention with a solution casting film forming apparatus, particularly a method for irradiating ultraviolet rays during film formation will be described.

  A cellulose ester dope composition containing an ethylenically unsaturated monomer or a compound having an epoxy group as described above is cast as a dope film from the die onto the surface of the metal support, and the organic solvent is evaporated on the metal support to form a web. (After casting, the dope film is referred to as a web), and the web is peeled before the metal support makes one round from the casting (when the residual solvent amount is 30 to 150% by mass). The metal support is a stainless steel belt or drum having a polished mirror surface. The web is heated on the metal support by applying hot air to the surface of the web, by gas heat transfer from the back surface of the metal support, or by liquid heat transfer from the back surface of the metal support. There is also a method in which the metal support is cooled to 20 ° C. or lower to solidify the dope film and peel off from the metal support without being dried too much.

The residual solvent amount can be expressed by the following formula.
Residual solvent amount (% by mass) = {(MN) / N} × 100
Here, M is the mass of the web at any point, and N is the mass when M is dried at 110 ° C. for 3 hours.

  After peeling off the web, the web is dried with a dryer that transports the web through rolls arranged in a staggered pattern and / or a dryer that transports the web by clipping both ends thereof to produce a cellulose ester film. The drying temperature of the web in the drying apparatus is 80 to 150 ° C., but it should be increased as the amount of residual solvent at that time decreases due to shrinkage of the web. Examples of the heating method include a method of blowing hot air, infrared irradiation, heating roll contact, microwave irradiation, and the like, which may be properly used. You may hold | maintain so that a width direction may not be shrunk | reduced with the tenter drying apparatus which hold | grips the both ends of a web after peeling, but may extend | stretch a little. As the tenter drying device, either a pin tenter method or a clip tenter method may be used, and as a cellulose ester film for a liquid crystal display device, a tenter drying device is used and stretched in the lateral direction by about 0.5 to 5%. preferable. The ultraviolet irradiation for photopolymerization according to the present invention may be performed at any place between casting the dope and completing the drying of the web, particularly when the web is on the metal support. It is preferable that when the organic solvent is appropriately present in the web, the movement of the molecule is easy, and the polymerization easily proceeds smoothly.

The ultraviolet irradiation source for photopolymerizing the ethylenically unsaturated monomer and the compound having an epoxy group according to the present invention is a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a carbon arc, a metal halide lamp, Sunlight etc. can be mentioned. Photopolymerization by irradiation with ultraviolet rays can be carried out in air or in an inert gas, but in the case of using an ethylenically unsaturated monomer, it may be in air, but oxygen can be used as much as possible to shorten the polymerization induction period. A gas with a low concentration is preferred. The irradiation intensity of the ultraviolet rays to be irradiated is preferably about 0.1 to 100 mW / cm ² , and the irradiation amount is preferably about 100 to 20000 mJ / cm ² .

  Next, a cellulose ester dope composition containing a polymer obtained by previously polymerizing an ethylenically unsaturated monomer according to another embodiment of the present invention will be described.

  Examples of the ethylenically unsaturated monomer constituting these polymers include those similar to the aforementioned ethylenic monomer. Of these, monomers mainly composed of vinyl esters are preferred. As the ethylenically unsaturated monomer, the same as described above, acrylic ester, vinyl ester, and maleic acid diester can be used, and those mainly composed of vinyl ester are particularly preferable. When the polymer is added to and mixed with the cellulose ester dope, the polymer can be uniformly mixed in the cellulose ester dope and has good compatibility even after becoming a cellulose ester film, and is preferably difficult to phase separate. As a polymerization method of these ethylenically unsaturated monomers, it can be carried out by methods such as solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, etc. by ordinary radical polymerization or cationic polymerization. In addition, after polymerization, any polymerization method may be added to the dope as a solution after precipitating and purifying the polymer, but in the case of solution polymerization, the polymerization solution can be added to the dope as it is. . The polymer must be dissolved in the organic solvent used in the cellulose ester dope composition. Examples of such an organic solvent include methylene chloride, ethylene chloride, chloroform, methyl acetate, methyl formate, ethyl formate, and fluoroalcohol. Particularly preferred are methylene chloride and methyl acetate.

Polymeric radical polymerization initiators useful in the present invention include benzoyl peroxide, acetyl peroxide, t-butyl hydroxy peroxide, t-butyl peroxide, cumene hydroperoxide, di-t-butyl peroxide, dicumene peroxide, azobisisobutyrate. Ronitrile, azobiscyclohexanecarbonitrile, hydrogen peroxide, potassium persulfate, ammonium persulfate, potassium persulfate and sodium bisulfite, benzoyl peroxide-ammonium ferrous sulfate, ammonium persulfate-sodium metasulfite, ammonium persulfate-thiosulfuric acid Commonly used initiators such as sodium can be used. In addition, as a cationic polymerization initiator, a cocatalyst having unpaired electrons such as Lewis acid such as BF ₃ , AlCl ₃ , TiCl ₄ , SnCl ₂ , SnCl ₄ and water, alcohol, carboxylic acid, ether, halogenated hydrocarbon, etc. Protonic acid such as sulfuric acid, phosphoric acid, trichloroacetic acid, trifluoroacetic acid, or cations such as I ₂ , BF ₃ O (C ₂ H ₅ ) ₂ , AgClO ₄ , (C ₆ H ₅ ) ₃ CCl Mention easy substances.

  Any organic solvent can be used as long as it does not easily cause chain transfer in the case of solution polymerization. For example, methanol, ethanol, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, 1,3-dioxolane, methyl acetate, ethyl acetate, methylene chloride and the like can be mentioned. In the case of emulsion polymerization, any of an anionic surfactant, nonionic surfactant, and cationic surfactant can be used, and a water-soluble polymer such as polyvinyl alcohol can also be used.

  The polymerization vessel is pressure-resistant and preferably equipped with a stirrer, a dropping funnel, a nitrogen stream introduction pipe and the like. The polymerization conditions are preferably carried out in a system in which air is substituted with nitrogen, and the polymerization temperature varies depending on the polymerization mode, but in the radical polymerization, a range of −10 to 100 ° C. is appropriate. Cationic polymerization is often carried out at extremely low temperatures, for example, −150 to −50 ° C., because the polymerization reaction is intense.

  The following are useful polymers for the present invention, but are not limited thereto.

  Here, x, y, and z are positive integers of 1 to 100, and x + y + z = 100. However, y of P-4-8 and UVP-7 is 1-50.

In the present invention, those described in JP-A-6-148430 are also preferably used in the present invention, in addition to the above-described polymers having UV-absorbing groups (UVP-1 to 7).
(Example of polymerization)
(Polymerization of P-1) 36 g of vinyl acetate monomer and 4 g of vinyl laurate monomer were placed in a 100 ml three-headed Kolben and reduced in pressure with a vacuum pump, and then purged with nitrogen three times. Dissolved in 60 ml of dehydrated tetrahydrofuran under nitrogen and heated to reflux. To this solution was added a solution of 30 mg of α, α 'azobisisobutyronitrile (AIBN) in tetrahydrofuran, and the mixture was heated to reflux for 3 hours for polymerization. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a minimum amount of tetrahydrofuran and reprecipitated with water. The precipitate was collected by filtration to obtain P-1. The mass ratio of each monomer unit of P-1 (vinyl acetate / vinyl laurate) was 90/10. Moreover, it was 16800 as a result of measuring the mass mean molecular weight of P-1 by GPC.
(Polymerization of UVP-1) 16 g of vinyl acetate monomer, 8 g of vinyl laurate monomer, and 16 g of UVM-1 monomer were placed in 100 ml of three-headed Kolben, and the pressure was reduced by a vacuum pump, followed by nitrogen substitution three times. Dissolved in 60 ml of dehydrated tetrahydrofuran under nitrogen and heated to reflux. A solution of AIBN (30 mg) in tetrahydrofuran was added to this solution, and polymerization was carried out by heating under reflux for 3 hours. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a minimum amount of tetrahydrofuran and reprecipitated with water. The precipitate was collected by filtration to obtain UVP-1. The mass ratio (x / y / z) of monomer units of UVP-1 was 40/20/40. It was 24400 as a result of measuring the mass mean molecular weight of UVP-1 by GPC.
(Polymerization of ASP-1) 24 g of vinyl acetate monomer and 16 g of ASM-1 monomer were put into a 100 ml three-headed Kolben, and the pressure was reduced by a vacuum pump, followed by nitrogen substitution three times. Dissolved in 60 ml of dehydrated tetrahydrofuran under nitrogen and heated to reflux. A solution of AIBN (30 mg) in tetrahydrofuran was added to this solution, and polymerization was carried out by heating under reflux for 3 hours. The solvent of the reaction solution was distilled off under reduced pressure, then dissolved in a minimum amount of tetrahydrofuran and reprecipitated with water. The precipitate was collected by filtration to obtain ASP-1. The mass ratio (x, y) of monomer units of ASP-1 was 60/40. It was 32000 as a result of measuring the mass mean molecular weight of ASP-1 by GPC.

  Since the cellulose ester film of the present invention does not substantially contain a low molecular plasticizer or an ultraviolet absorber, there is nothing that precipitates or volatilizes from the web during production, so that the web is not soiled, and the liquid crystal display device Then, the film is hardly deposited or volatilized even in a hot and humid state in a sealed automobile, so it can be said to be an ideal film.

  The retentivity indicating the change in mass due to the deposition and volatilization of substances from the film under high-temperature and high-humidity conditions is preferably almost zero. However, since there is a residual solvent in the film, a slight decrease in mass is inevitable. The retention in the present invention is preferably 1.0% or less, preferably 0.5% or less, more preferably 0.1% or less.

  Moreover, the dimensional stability of the cellulose ester film with respect to high temperature and humidity is also improved, and the dimensional change rate is smaller than the cellulose ester film not containing the polymer of the invention. The dimensional change rate of the cellulose ester film of the present invention is preferably within ± 1.0%, more preferably within ± 0.5% in a treatment for 50 hours under high temperature and high humidity of 80 ° C. and 90% RH. More preferably, it is within ± 0.4%, particularly preferably within ± 0.3%.

  The high temperature and high humidity properties as described above are basically not all, but often depend on water absorption. The cellulose ester film containing the polymer of the present invention has excellent properties such that the water absorption is smaller than the film not containing them. In general, the water absorption of the cellulose ester film is less than about 3% by mass under high humidity, whereas the cellulose ester film of the present invention is characterized by 2% by mass or less.

  The cellulose ester film of the present invention containing a polymer having an ultraviolet absorbing group can effectively cut ultraviolet rays without a decrease in ultraviolet absorbing material. Moreover, there is no deterioration of the ultraviolet absorption performance even under high temperature and high humidity.

  In addition, when the cellulose ester film of the present invention contains a polymer having an antistatic group, it is possible to provide a film with a high yield that hardly adsorbs foreign matters such as dust during production or handling.

  It was also found that when the cellulose ester film of the present invention contains a polymer, the retardation is improved without increasing the thickness of the film and an excellent retardation is exhibited.

  Furthermore, in the cellulose ester film production process, the curl of the film caused by the movement of the plasticizer in the thickness direction of the film during the conventional production is not caused by the cellulose ester film containing the polymer of the present invention. Curling is also difficult to occur and good flatness can be obtained.

  In addition to the above, the cellulose ester film containing the polymer of the present invention has physical, mechanical or chemical properties equivalent to or higher than those of a normal cellulose ester film not containing a polymer.

  The cellulose ester dope composition of the present invention preferably contains a fine particle matting agent, and the cellulose ester film as a protective film for a polarizing plate after film formation has an appropriate amount due to the presence of the fine particle matting agent. Sliding and scratch-resistant. The fine particle matting agent is mixed and dispersed in the cellulose ester dope. Examples of the fine particle matting agent include inorganic substances such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate. It is preferable to contain fine particles and crosslinked polymer fine particles. Of these, silicon dioxide is preferable because it can reduce the haze of the film. The average particle size of the secondary particles of the fine particles is in the range of 0.01 to 1.0 μm, and the content is preferably 0.005 to 0.3% by mass with respect to the cellulose ester. In many cases, fine particles such as silicon dioxide are surface-treated with an organic substance, particularly a compound having a methyl group, but such a substance is preferable in the present invention because the haze of the film can be reduced. Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes (particularly methoxysilane), silazane, siloxane and the like. The larger the average particle size of the fine particles, the greater the mat effect, and on the contrary, the smaller the average particle size, the better the transparency. Therefore, the average particle size of the preferred primary particles is 5 to 50 nm, more preferably 7 to 14 nm. It is. These fine particles are usually present as aggregates in the cellulose ester film, and it is preferable to form irregularities of 0.01 to 1.0 μm on the surface of the cellulose ester film. As the fine particles of silicon dioxide, AEROSIL 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, TT600, etc. manufactured by Aerosil Co., can be mentioned, preferably AEROSIL R972, R972V, R974, R202, R812. Two or more of these matting agents may be used in combination. When using 2 or more types together, it can mix and use in arbitrary ratios. In this case, matting agents having different average particle sizes and materials, for example, AEROSIL 200V and R972V can be used in a mass ratio of 0.1: 99.9 to 99.9 to 0.1.

<Semi IPN type polymer alloy>
The transparent film of the present invention comprises a cellulose ester according to the present invention which is a non-crosslinked polymer and a semi-IPN type polymer alloy of the crosslinked polymer according to the present invention.

  Here, IPN is an interpenetrating network structure, and semi-IPN is an IPN in which one is a crosslinked polymer and the other is a non-crosslinked polymer. The semi-IPN type polymer alloy includes, for example, a method in which a monomer and / or oligomer for a crosslinked polymer is crosslinked and polymerized in a state in which a non-crosslinked polymer is dissolved, or a monomer and / or a crosslinked polymer in the presence or absence of a solvent. It can be formed by non-crosslinking polymerization of a monomer in a state swollen with an oligomer. However, in the present invention, it is not necessary that the crosslinked polymer and the non-crosslinked polymer are completely compatible with each other, and those in which the phases are separated are included. Even when the crosslinked polymer and the non-crosslinked polymer are phase-separated, each of the crosslinked polymer-rich phase and the non-crosslinked polymer-rich phase has a semi-IPN structure. However, the transparent film of the present invention is not a blend of a crosslinked polymer formed into particles and a non-crosslinked polymer. This can be confirmed by the fact that most of the crosslinked polymer is not dispersed in the form of particles when the transparent film of the present invention is immersed in a solvent that dissolves the non-crosslinked polymer.

The transparent film made of the semi-IPN type polymer alloy can achieve both physical properties such as high hardness and heat resistance of the crosslinked polymer, and flexibility and optical properties of the non-crosslinked polymer.
<Crosslinked polymer>
The cross-linked polymer used in the semi-IPN structure type polymer alloy of the present invention is not particularly limited, and examples thereof include epoxy resins, phenol resins, melamine resins, cross-linked vinyl polymers, and polycyanurates. Is used, and a crosslinked vinyl polymer having high heat resistance is used. The crosslinked vinyl polymer can be obtained by polymerizing a low molecular compound having a polymerizable unsaturated double bond by heating or irradiation with energy rays.

  In the present invention, the low molecular weight compound is a compound having a molecular weight of 1000 or less and cannot be formed as a film by itself.

  Examples of the low molecular weight compound having a polymerizable unsaturated double bond used in the present invention include alkenyl groups such as vinyl groups and allyl groups, unsaturated fatty acid residues such as acrylic acid residues and methacrylic acid residues, etc. And low molecular weight compounds.

  There is no particular limitation on the low molecular weight compound having a polymerizable unsaturated double bond used in the present invention, but it may be compatible without causing haze, bleeding out or volatilization in the film at the mixing stage before polymerization. It preferably has a functional group capable of interacting with a cellulose derivative by hydrogen bonding or the like.

  Examples of such functional groups include hydroxyl groups, ether groups, carbonyl groups, ester groups, carboxylic acid residues, amino groups, imino groups, amide groups, imide groups, cyano groups, nitro groups, sulfonyl groups, sulfonic acid residues, Examples thereof include a phosphonyl group and a phosphonic acid residue, and a carbonyl group, an ester group, and a phosphoryl group are preferable.

  Examples of functional groups having such a functional group and simultaneously having a polymerizable unsaturated double bond include acrylic acid, methacrylic acid, undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid. A low molecular weight compound having a saturated fatty acid residue is preferably used.

  Moreover, since a thing with a high superposition | polymerization rate is preferable and the thing which can be energy-beam curable is preferable, acrylic type and / or methacryl type [This is described as (meth) acrylic type. The same applies to (meth) acryl groups, (meth) acrylates, (meth) acryloyl, etc.)], ie, those containing (meth) acryloyl groups.

  As a low molecular weight compound satisfying such conditions and imparting heat resistance to the crosslinked polymer and having a plurality of polymerizable unsaturated double bonds preferably used in the present invention, (meth) acrylic acid and polyhydric alcohol Examples include esters.

The polyhydric alcohol used in the present invention is represented by the following general formula (2).
General formula (2) R ^1- (OH) _n (where R ¹ is an n-valent organic group, n is a positive integer of 2 or more, and the OH group represents an alcoholic and / or phenolic hydroxyl group)
Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these.

  Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol and the like. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  The unsaturated carboxylic acid used in the polyhydric alcohol ester may be one type or a mixture of two or more types. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  Below, the specific compound of the polyhydric alcohol unsaturated carboxylic acid ester which is a low molecular compound which has multiple polymerizable unsaturated double bonds preferably used for this invention is shown.

  In addition to these, the following compounds can also be preferably used as the low molecular weight compound having a plurality of polymerizable unsaturated double bonds.

  For example, divinylsulfone, divinylbenzene, 1,4-butanediol divinyl ether, diallylamine, diallyl sulfide, diallyl disulfide, diallyl phthalate, triaryltriazine-2,4,6 (1H, 3H, 5H) -trione, N, N '-1,3-phenylenedimaleimide, N, N'-1,4-phenylenedimaleimide, (3-acryloxypropyl) trimethoxysilane, allyltriethoxysilane, allyltriphenylsilane, (5-bicycloheptenyl) ) Triethoxysilane, boron vinyldimethylsiloxide, butenyltriethoxysilane, divinyldimethylsilane, divinyltetramethyldisilane, 1,3-diallyltetramethyldisiloxane, 1,3-divinyl-1,3-diphenyl-1, 3-Dimethyl Disiloxane, hexavinyldisiloxane, methacryloxyethoxytrimethylsilane, methacryloxypropylheptacyclopentyl-T8-silsesquioxane, octavinyl-T8-silsesquioxane, methacryloxypropylmethyldiethoxysilane, methacryloxypropyltrimethoxysilane , Methacryloxypropyltris (vinyldimethylsiloxy) silane, pentavinylpentamethylcyclopentasiloxane, styrylethyltrimethoxysilane, tetraallylsilane, tetraallyloxysilane, tetrakis (2-methacryloxyethoxy) silane, tetrakis (vinyldimethylsiloxy) Silane, 1,1,3,3-tetravinyldimethyldisiloxane, tetravinylsilane, 1,3,5,7-tetravinyl-1,3 5,7-tetramethylcyclotetrasiloxane, trivinylethoxysilane, vinylmethyldimethoxysilane, 1-phenyl-1-trimethylsiloxyethylene, 2-trimethylsiloxy-4-allyloxydiphenyl ketone, tris (vinyldimethylsiloxy) methylsilane, Trivinylethoxysilane, trivinylmethylsilane, trivinylsilane, 1,3,5-trivinyl-1,3,5-trimethylcyclotrisilazane, 1,3,5-trivinyl-1,1,3,3,5, 5-pentamethyltrisiloxane, vinyltriacetoxysilane, vinyltriisopropenoxysilane, vinyltrimethoxysilane, aluminum acrylate, methacryloxytri-n-butyltin, tetraallyltin, boron vinyldimethylsiloxide, titanium Allyl acetoacetate triisopropoxide, titanium methacrylate isopropoxide, zirconium dimethacrylate dibutoxide, zirconium methacryloxyethyl acetoacetate tri-n-propoxide, copper (II) methacryloxyethyl acetoacetate, (meth) acrylic epoxy resin Oligomers such as acid esters, (meth) acrylic esters of polyester resins, (meth) acrylic esters of polyether resins, (meth) acrylic esters of polybutadiene resins, polyurethane resins having (meth) acryloyl groups at the molecular ends, Etc.

  These low molecular compounds having a polymerizable unsaturated double bond can be used alone or in combination of two or more. In addition, a low molecular compound having one unsaturated double bond group may be included in the structure of the crosslinked polymer, but in order to maintain the heat resistance of the crosslinked polymer, 50% by mass or more of the crosslinked polymer is contained in the present invention. It is preferably composed of a low molecular compound having a plurality of such unsaturated double bond groups.

  Moreover, as content of the crosslinked polymer which concerns on this invention in a transparent film, 5-50 mass% is preferable with respect to the total mass of a transparent film. If the amount of the crosslinked polymer added is less than 5% by mass, the effect of improving the heat resistance due to the addition of the crosslinked polymer is not recognized, and it tends to flow during high-temperature heating, which is not preferable. On the other hand, if it exceeds 50% by mass, the transparent film becomes brittle, which is not preferable.

Furthermore, the cellulose ester film of the present invention preferably has the following configuration in order to ensure good flatness and anti-tacking properties.
The cellulose ester film of the present invention has a multilayer structure having at least a base layer and a surface layer, and a matting agent is added only to the surface layer. This surface layer may be laminated only on one side of the base layer, or may be laminated on both sides of the base layer. That is, as shown in FIG. 6, a three-layer mode comprising a base layer 1 and a surface layer 2 laminated on both sides thereof, and as shown in FIG. 7, a base layer 1 and a surface layer 2 laminated on one surface thereof, There are two-layer embodiments. The surface layer is laminated at a position located on the surface, and another layer can be laminated between the base layer and the surface layer.

  In such a cellulose ester film, a matting agent is added only to the surface layer, and no matting agent is added to the base layer. That is, by adding a matting agent only to the surface layer, it ensures the flatness and anti-tacking property of the surface of the cellulose ester film, and in the base layer (including the intermediate layer when other layers are laminated in the middle). By not adding a matting agent, the transparency of the entire cellulose ester film is secured.

Examples of the matting agent that can be added to the surface layer of the cellulose ester film of the present invention include SiO ₂ , TiO ₂ , BaSO ₄ , CaCO ₃ , talc, and kaolin. In addition, examples of inorganic compounds include fine powders of inorganic substances such as barium sulfate, manganese colloid, titanium dioxide, strontium barium sulfate, and silicon dioxide. Further, for example, synthetic silica obtained by wet method or gelation of silicic acid, etc. And titanium dioxide (rutile type or anatase type) produced by silicon dioxide or titanium slug and sulfuric acid. It can also be obtained by pulverizing from an inorganic substance having a relatively large particle size, for example, 20 μm or more, and then classifying (vibration filtration, wind classification, etc.). A preferred inorganic compound matting agent includes conductive fine particles. Specifically, at least one crystalline metal oxide selected from ZnO, TiO ₃ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, and MoO ₃ , or these There are fine composite oxide particles.

  Further, examples of the matting agent made of a polymer compound include polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethylene carbonate, starch, and the like. . Further, a polymer compound synthesized by a suspension polymerization method, a polymer compound made spherical by a spray drying method or a dispersion method, or an inorganic compound can be used. Moreover, the polymer compound which is a polymer of one kind or two or more kinds of monomer compounds described below may be formed into particles by various means.

  For example, acrylic acid esters, methacrylic acid esters, vinyl esters, styrenes, and olefins are preferably used. Moreover, you may use the particle | grains which have a fluorine atom or a silicon atom as described in Unexamined-Japanese-Patent No. 62-14647, 62-17744, 62-177743. Among these, the particle composition preferably used is polystyrene, polymethyl (meth) acrylate, polyethyl acrylate, poly (methyl methacrylate / methacrylic acid = 95/5) (molar ratio), poly (styrene / styrenesulfonic acid = 95/5). ) (Molar ratio), polyacrylonitrile, poly (methyl methacrylate / ethyl acrylate / methacrylic acid = 50/40/10), silica and the like.

As the matting agent, various inorganic compounds and polymer compounds can be used as described above, but inorganic compounds are preferable for the dispersant using methylene chloride, and silica (SiO ₂ ) is particularly inexpensive and easily available. preferable.

The addition amount of the matting agent is preferably ^{5~500mg / m 2, 10~100mg / m} 2 is more preferable. When the addition amount of the matting agent is less than 5 mg / m ² , it becomes difficult to ensure the slipperiness and tackiness prevention property of the cellulose ester film surface, and when it exceeds 500 mg / m ² , the transparency is deteriorated.

  The thickness of the surface layer of the cellulose ester film is preferably 0.0002 mm to 0.02 mm, and more preferably 0.0005 mm to 0.01 mm. If the thickness of the surface layer is less than 0.0002 mm, it is difficult to form a uniform layer. On the other hand, if the thickness of the surface layer exceeds 0.02 mm, the advantage of lamination may be impaired.

  The total thickness of the cellulose ester film is appropriately determined depending on the use of the photographic material, the optical material, etc., but is generally set in the range of 0.02 mm to 0.5 mm.

  The center line average roughness of the surface layer of the cellulose ester film according to the present invention is preferably 0.01 μm to 5 μm, and the center line average roughness is more preferably 0.1 μm to 1 μm. When the center line average roughness of the surface layer is less than 0.01 μm, the film is squeaked and fine scratches are generated. On the other hand, if the center line average roughness exceeds 5 m, the flatness is deteriorated.

  In producing a cellulose ester film, a cellulose ester, a plasticizer and a solvent (including a matting agent in the case of a surface layer) are generally used. The cellulose ester is typically a lower fatty acid ester of cellulose (eg, cellulose acetate, cellulose acetate butyrate and cellulose acetate propionate). Lower fatty acid means a fatty acid having 6 or less carbon atoms. Cellulose acetate includes cellulose triacetate (TAC) and cellulose diacetate (DAC).

  Typical phosphoric ester plasticizers are represented by the following formulas (Ia) and (Ib).

In the formulas (Ia) and (Ib), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each an alkyl group (including a cycloalkyl group), an aryl group or an aralkyl group. is there. Each group may have a substituent. The alkyl group preferably has 1 to 12 carbon atoms. Examples of alkyl groups include methyl, ethyl, butyl, cyclohexyl and octyl. An example of an aryl group is phenyl. An example of an aralkyl group is benzyl. Examples of the substituent include an alkyl group (eg, methyl), an aryl group (eg, phenyl), an alkoxy group (eg, methoxy, butoxy) and an aryloxy group (eg, phenoxy). In the formula (Ib), R ⁸ is a divalent linking group selected from an alkylene group, an arylene group, a sulfonyl group, and combinations thereof. n is an integer of 1 or more, and preferably 1 to 10.

  The plasticizer is preferably a phosphate plasticizer, and examples of the phosphate plasticizer include triphenyl phosphate, biphenyl diphenyl phosphate, tricresyl phosphate, octyl diphenyl phosphate, triethyl phosphate and tributyl phosphate. It is. In addition, a carboxylic acid ester plasticizer may be used. Examples of carboxylate plasticizers include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diethyl hexyl phthalate, dimethoxyethyl phthalate, glycerol triacetate, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalate Ruethyl glycolate and triacetin are included. Examples of citrate esters include acetyl triethyl citrate (OACTE) and tributyl citrate (OACTB). Examples of other carboxylic acid esters include butyl oleate (BO), methylacetyl linoleate (MAL), and sebatin. Examples include dibutyl acid (DBS) and various trimellitic acid esters. Examples of other low molecular plasticizers include o- or p-tolueneethylsulfonamide.

  Generally, the plasticizer is used in the range of 5 to 40% by mass with respect to the cellulose ester. It is preferable to use it in the quantity of 10-20 mass% with respect to a cellulose ester. Trimellitic acid or pyromellitic acid ester may be used in combination with a phosphate ester plasticizer. Trimellitic acid and pyromellitic acid esters have the effect of preventing bleed out of the phosphate ester plasticizer. The esters of these acids are described in JP-A-5-5047.

  As the solvent, a lower aliphatic hydrocarbon chloride or a lower aliphatic alcohol is generally used. An example of a lower aliphatic hydrocarbon chloride is methylene chloride. Examples of lower aliphatic alcohols include methanol, ethanol, n-propyl alcohol, isopropyl alcohol and n-butanol. Examples of other solvents are substantially free of halogenated hydrocarbons, acetone, and ketones having 4 to 12 carbon atoms include, for example, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone, carbon Examples of the ester having 3 to 12 atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate and 2-ethoxy-ethyl acetate. Examples of alcohols from 1 to 6 include methanol, ethanol, propanol, iso-propanol, 1-butanol, t-butanol, 2-methyl-2-butanol, 2-methoxyethanol, 2-butoxyethanol and the like, and carbon atoms The number is 3 The ethers up to 12 include, for example, diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole, phenetole and the like, and cyclic carbonization having 5 to 8 carbon atoms. Examples of hydrogens include cyclopentane, cyclohexane, cycloheptane, and cyclooctane.

  Of these solvents, methylene chloride is particularly preferred. Other solvents may be mixed with methylene chloride. However, the mixing ratio of methylene chloride is preferably 70% by mass or more. Particularly preferred mixing ratios are 75 to 93% by mass for methylene chloride and 7 to 25% by mass for other solvents. The solvent is removed in the formation of the cellulose ester film. The residual amount of solvent is generally less than 5% by weight. The residual amount is preferably less than 1% by mass, and more preferably less than 0.5% by mass.

  An ultraviolet absorber can be added to the cellulose ester film of the present invention, and examples of the ultraviolet absorber include benzophenone-based, salicylate-based, and benzotriazole-based compounds. Examples of the benzophenone-based ultraviolet absorber include 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-dodecyloxybenzophenone. An example of the salicylate-based ultraviolet absorber is 4-t-butylphenyl salicylate. Examples of benzotriazole ultraviolet absorbers include 2- (hydroxy-5-t-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (2′-hydroxy). -3,5'-di-t-butylphenyl) -5-chlorobenzotriazole. Examples of other ultraviolet absorbers include [2,2′-thiobis (4-t-octylphenolate)] n-butylamine nickel II. The amount of the ultraviolet absorber used is generally in the range of 0.1 to 3.0% by mass relative to the cellulose ester.

  Matting agents, plasticizers, ultraviolet absorbers and the like may be added in advance in the dope in the dissolution tank, or may be added and mixed online in the middle of the dope feeding pipe.

  In order to produce the cellulose ester film of the present invention, a lamination casting method such as a co-casting method (multi-layer simultaneous casting), a sequential casting method, or a coating method can be used. When manufacturing by the co-casting method and the sequential casting method, first, dope for each layer is prepared. The co-casting method is based on a casting giusa that extrudes each casting dope for each layer (or three or more layers) on a casting support (band or drum) simultaneously from another slit or the like. This is a casting method in which a dope is extruded and each layer is cast at the same time, peeled off from a support at an appropriate time, and dried to form a film.

  In the sequential casting method, the casting dope for the first layer is first extruded from the casting gussa on the casting support and cast for the second layer without drying or drying. The dope for casting is extruded from the casting giusa, and thereafter, the dope of the third layer and thereafter is successively cast and laminated, peeled off from the support at an appropriate time, and dried to form a film. This is a casting method for molding.

  In general, the base layer film is formed by a solution casting method to prepare a coating solution to be applied to form a surface layer, and is applied to the film one side at a time or on both sides simultaneously using an appropriate coating machine. In this method, a coating film is applied and dried to form a film having a laminated structure.

  As described above, any of the co-casting method, the sequential casting method, and the coating method may be used for producing the cellulose ester film of the present invention. However, in general, the drying load after coating increases in the coating method, and the process becomes complicated in the sequential casting method, and it is difficult to maintain the flatness of the film. Since it is simple, the productivity is high, and the flatness of the film can be obtained relatively easily, it is preferable to manufacture by a co-casting method.

  The apparatus for producing the cellulose ester film of the present invention may be a solution casting apparatus using a casting band whose surface is mirror-finished or a solution casting apparatus using a casting drum. A solution casting apparatus using a casting band is shown in FIG. 8, and a solution casting apparatus using a casting drum is shown in FIG.

  In the band-type solution casting apparatus shown in FIG. 8, 11 is a stirrer into which cotton, a plasticizer and a solvent are charged. This stirrer 11 includes a transfer pump 12, a filter 13, a stock tank 14, It is connected to a casting die 17 via a casting liquid pump 15 and an additive injection pump 16 for adding a matting agent, a dye, an ultraviolet absorber (UV agent) and the like. A casting band 18 and a decompression chamber 19 are provided below the casting die 7.

  In the drum type solution casting apparatus shown in FIG. 9, reference numeral 20 denotes a casting drum, which is provided in place of the casting band 18 in the band type solution casting apparatus. The stirrer 11, the transfer pump 12, the filter 13, the stock tank 14, the casting liquid pump 15, the additive injection pump 16, and the casting die 17 are configured identically.

  As the casting die, those shown in FIGS. 10, 11 and 12 can be used.

  FIG. 10 shows a casting die used for forming a single-layer film, which is used for the sequential casting method. The casting die 30 has a single manifold 31 formed therein. FIG. 11 shows a multi-manifold type co-casting die. The co-casting die 30 is formed with three manifolds 32 and can form a film having a three-layer structure. FIG. 12 shows a feed block type co-casting die. The co-casting die 30 is provided with a manifold 33 and a feed block 34, and is joined by the feed block 34 to form a plurality of layers (FIG. 12). In this case, the dope having three layers is cast.

  In the above casting die, a coat hanger die is used, but the present invention is not limited to this, and a die having another shape such as a T die may be used.

  Further, the cellulose ester film of the present invention preferably contains an antioxidant. As the antioxidant, a hindered phenol compound is preferably used, and 2,6-di-t-butyl-p -Cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4) -Hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6 -(4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, 2,2-thio-diethylenebis [3- (3 -Di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6 -Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate and the like can be mentioned. In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] is preferred. Further, for example, hydrazine-based metal deactivators such as N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine and tris (2,4-di-t A phosphorus-based processing stabilizer such as -butylphenyl) phosphite may be used in combination. The amount of these compounds added is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio with respect to the cellulose ester.

Next, the hard coat layer will be described below.
<Hard coat layer>
The hard coat layer is a translucent resin for imparting hard coat properties, translucent fine particles for imparting antiglare properties, and an inorganic filler for increasing the refractive index, preventing cross-linking shrinkage, and increasing the strength, reaction It is composed of an initiator for initiating oxidization, additives such as a leveling agent, a thixotropic agent, and an antistatic agent.

<Translucent fine particles>
The average particle size of the translucent fine particles is preferably 0.5 to 10 μm, more preferably 2.0 to 6.0 μm. If the average particle size is less than 0.5 μm, the light scattering angle distribution spreads to a wide angle, which may cause blurring of characters on the display. On the other hand, when the thickness exceeds 10 μm, it is necessary to increase the thickness of the hard coat layer, which causes problems such as an increase in curling and an increase in material cost.
Specific examples of the translucent fine particles include organic particles such as poly ((meth) acrylate) particles, crosslinked poly ((meth) acrylate) particles, polystyrene particles, crosslinked polystyrene particles, crosslinked poly (acryl-styrene) particles, Preferred are resin particles such as melamine resin particles and benzoguanamine resin particles. Examples of the inorganic particles include silica particles, alumina particles, zirconia particles, titania particles, and inorganic particles having hollows and pores. Of these, cross-linked polystyrene particles, cross-linked poly ((meth) acrylate) particles, and cross-linked poly (acryl-styrene) particles are preferably used. By adjusting the refractive index of the light-sensitive resin, the internal haze, surface haze, and centerline average roughness of the present invention can be achieved. Specifically, a translucent resin (having a refractive index after curing of 1.50 to 1.1) mainly composed of a tri- or higher functional (meth) acrylate monomer preferably used in the hard coat layer of the present invention as described later. 53) and a combination of translucent fine particles composed of a crosslinked poly (meth) acrylate polymer having an acrylic content of 50 to 100 mass percent, particularly from the translucent resin and the crosslinked poly (styrene-acrylic) copolymer. A combination with translucent fine particles (with a refractive index of 1.48 to 1.54) is preferable.

  Further, two or more kinds of translucent fine particles having different particle diameters may be used in combination. It is possible to impart an antiglare property with the light-transmitting fine particles having a larger particle diameter, and to reduce the roughness of the surface with the light-transmitting fine particles having a smaller particle diameter.

The translucent fine particles are blended in the formed hard coat layer so as to be contained in an amount of 3 to 30% by mass in the total solid content of the hard coat layer. More preferably, it is 5-20 mass%. When it is less than 3% by mass, the antiglare property is insufficient, and when it exceeds 30% by mass, problems such as image blur, surface turbidity and glare occur.
Moreover, the density of the translucent fine particles is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ² .

In the present invention, the refractive index of the translucent resin and the translucent fine particles is preferably 1.45 to 1.70, more preferably 1.48 to 1.65. In order to set the refractive index within the above range, the kind and amount ratio of the light-transmitting resin and the light-transmitting fine particles may be appropriately selected. How to select can be easily known experimentally in advance.
In the present invention, the difference in refractive index between the translucent resin and the translucent fine particles (the refractive index of the translucent fine particles−the refractive index of the translucent resin) is preferably 0.001 to an absolute value. It is 0.030, More preferably, it is 0.001-0.020, More preferably, it is 0.001-0.015. If this difference exceeds 0.030, problems such as film character blur, a decrease in dark room contrast, and surface turbidity occur.
Here, the refractive index of the translucent resin can be quantitatively evaluated by directly measuring the refractive index with an Abbe refractometer or by measuring a spectral reflection spectrum or a spectral ellipsometry. The refractive index of the light-transmitting fine particles is obtained by measuring the turbidity by dispersing an equal amount of the light-transmitting fine particles in a solvent in which the refractive index is changed by changing the mixing ratio of two types of solvents having different refractive indexes. It is measured by measuring the refractive index of the solvent when the turbidity is minimized with an Abbe refractometer.

  Examples of the method for producing the light-transmitting fine particles according to the present invention include a suspension polymerization method, an emulsion polymerization method, a soap-free emulsion polymerization method, a dispersion polymerization method, a seed polymerization method, and the like. Good. These production methods are described in, for example, “Experimental Methods for Polymer Synthesis” (Takayuki Otsu and Masaaki Kinoshita, Chemical Dojinsha), pages 130 and 146 to 147, “Synthetic Polymers”, Vol. 246-290, 3rd volume, p. 1 to 108, etc., and Japanese Patent Nos. 2543503, 3508304, 2746275, 3521560, 3580320, and Japanese Patent Laid-Open No. 10-1561. Reference can be made to methods described in JP-A No. 7-2908, JP-A No. 5-297506, JP-A No. 2002-145919, and the like.

The particle size distribution of the translucent fine particles is preferably monodisperse particles in view of haze value and controllability of diffusibility, and uniformity of the coated surface. For example, when particles having a particle size of 20% or more than the average particle size are defined as coarse particles, the proportion of the coarse particles is preferably 1% or less of the total number of particles, more preferably 0.1% or less. Yes, more preferably 0.01% or less. Particles having such a particle size distribution are also effective means of classification after the preparation or synthesis reaction, and particles having a desired distribution can be obtained by increasing the number of classifications or increasing the degree of classification. .
It is preferable to use a method such as an air classification method, a centrifugal classification method, a sedimentation classification method, a filtration classification method, or an electrostatic classification method for classification.

  1-10 micrometers is preferable and, as for the film thickness of a hard-coat layer, 1.2-8 micrometers is more preferable. If it is too thin, the hard property is insufficient, and if it is too thick, curling and brittleness may be deteriorated and workability may be lowered.

<Translucent resin>
The translucent resin is preferably a binder polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a binder polymer having a saturated hydrocarbon chain as a main chain. The binder polymer preferably has a crosslinked structure.
As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.
In order to increase the refractive index of the binder polymer, the monomer structure has a high refractive index including at least one atom selected from an aromatic ring, a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom. It is also possible to select a monomer having a ratio, a monomer having a fluorene skeleton in the molecule, and the like.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid [for example, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di ( (Meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3- Chlorohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate], ethylene oxide-modified products and caprolactone-modified products of the above esters, vinylbenzene and its derivatives [eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2- Acryloyl ethyl ester, 1,4-divinylcyclohexanone], vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  Specific examples of the high refractive index monomer include (meth) acrylates having a fluorene skeleton, bis (4-methacryloylthiophenyl) sulfide, vinylnaphthalene, vinylphenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenylthioether, etc. Is mentioned. Two or more of these monomers may be used in combination.

Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Therefore, the hard coat layer is composed of a monomer for forming a translucent resin such as the above-mentioned ethylenically unsaturated monomer, a photo radical initiator or a thermal radical initiator, translucent fine particles, and an inorganic material as described later if necessary. It can be formed by preparing a coating liquid containing a filler and curing the coating liquid on a transparent support by a polymerization reaction by ionizing radiation or heat.

Photo radical polymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds , Fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like.
Examples of acetophenones include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxy-dimethylphenylketone, 1-hydroxy-dimethyl-p-isopropylphenylketone, 1-hydroxy Cyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 4-phenoxydichloroacetophenone, 4-t- Butyl-dichloroacetophenone is included.
Examples of benzoins include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether It is.
Examples of benzophenones include benzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone, 4,4'-dimethylaminobenzophenone (Michler's ketone), 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone and the like are included.
Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
Examples of the active esters include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (0-benzoyloxime)], sulfonic acid esters, cyclic active ester compounds, and the like.
Examples of the onium salts include aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts.
Examples of borate salts include ion complexes with cationic dyes.
Examples of active halogens include S-triazine and oxathiazole compounds, such as 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine and 2- (p-methoxyphenyl). ) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-styrylphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (3-Br-4-di ( Ethyl acetate) amino) phenyl) -4,6-bis (trichloromethyl) -S-triazine, 2-trihalomethyl-5- (p-methoxyphenyl) -1,3,4-oxadiazole.
An example of an inorganic complex is bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium.
Examples of coumarins include 3-ketocoumarin.
These initiators may be used alone or in combination.
“Latest UV Curing Technology”, Technical Information Association, 1991, p. Various examples are also described in 159 and are useful in the present invention.
Commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 819, 907, 1870 (CGI-403 / Irg184 = 7/3 mixed initiator, 500) manufactured by Ciba Specialty Chemicals, Inc. , 369, 1173, 2959, 4265, 4263, etc.), OXE01), etc., Kayacure (DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, manufactured by Nippon Kayaku Co., Ltd. , ITX, QTX, BTC, MCA, etc.), Esacure manufactured by Sartomer (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, TZT) and the like are preferable examples.
It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, More preferably, it is the range of 1-10 mass parts.
In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone.
Further, one or more auxiliary agents such as an azide compound, a thiourea compound, and a mercapto compound may be used in combination.
Examples of commercially available photosensitizers include Kayacure (DMBI, EPA) manufactured by Nippon Kayaku Co., Ltd.

As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.
Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Diazo compounds such as ammonium sulfate, potassium persulfate and the like, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (propionitrile), 1,1′-azobis (cyclohexanecarbonitrile), etc. And diazoaminobenzene, p-nitrobenzenediazonium and the like.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Therefore, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, translucent fine particles and an inorganic filler is prepared, and the coating liquid is applied onto a transparent support and then polymerized by ionizing radiation or heat. It can be cured by reaction to form a light diffusion layer.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

In addition to the above light-transmitting fine particles, silicon, titanium, zirconium, aluminum, indium, zinc, tin are used for the hard coat layer in order to adjust the refractive index of the layer and reduce the haze value due to internal scattering. And an inorganic filler comprising an oxide of at least one metal selected from antimony and having an average particle size of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less. Good. Since these inorganic fillers generally have a specific gravity higher than that of organic substances and can increase the density of the coating composition, they also have the effect of slowing the sedimentation rate of the light-transmitting fine particles.
The surface of the inorganic filler used in the hard coat layer is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.
When using these inorganic fillers, the addition amount is preferably 10 to 90% of the total mass of the hard coat layer, more preferably 20 to 80%, and particularly preferably 30 to 75%.
Such an inorganic filler does not scatter because its particle size is sufficiently smaller than the wavelength of light, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.
An organosilane compound can be used for the hard coat layer. The addition amount of the organosilane compound is preferably 0.001 to 50% by mass, more preferably 0.01 to 20% by mass, and still more preferably 0.05 to 10% by mass, based on the total solid content of the containing layer (addition layer). 0.1 to 5% by mass is particularly preferable.

<Leveling agent for hard coat layer>
Hereinafter, a copolymer containing a fluoroaliphatic group that can be preferably used in the present invention (hereinafter, the copolymer may be simply referred to as “fluorine leveling agent”) will be described in detail.

  The fluorine leveling agent of the present invention has a repeating unit corresponding to the fluoroaliphatic group-containing monomer A represented by the following general formula [1], general formula [2], general formula [3] or general formula [4]. A fluoroaliphatic group-containing copolymer containing at least one kind and at least one repeating unit corresponding to the monomer B represented by the following general formula [5] not containing a fluoroaliphatic group is preferable.

(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 n represents an integer of 1 to 18.)

(In General Formula [2], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, X represents an oxygen atom, a sulfur atom or —N (R ² ) —, m is an integer of 1-6, n Represents an integer of 1 to 18. Here, R ² represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may have a substituent.

(In the general formula [3], R ³ represents a hydrogen atom, a halogen atom or a methyl group, L ² represents a divalent linking group, and n represents an integer of 1 to 6.)

(In the general formula [4], R ⁴ represents a hydrogen atom or a methyl group, X represents an oxygen atom, a sulfur atom or —N (R ² ) —, m is an integer of 1 to 6 and n is 1 to 6) Represents the following integer: represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may have a substituent.

(In General Formula [5], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, L ¹ represents a divalent linking group, and Y represents a straight chain having 1 to 20 carbon atoms which may have a substituent. A chain, branched, or cyclic alkyl group or an aromatic group that may have a substituent.

The fluoroaliphatic group-containing monomer represented by the general formula [1] will be described.
In the general formula [1], R ⁰ represents a hydrogen atom, a halogen atom or a methyl group, more preferably a hydrogen atom or a methyl group. L represents a divalent linking group, and a divalent linking group containing an oxygen atom, a sulfur atom or a nitrogen atom is preferred. L represents a divalent linking group containing any one of an oxygen atom, a nitrogen atom, and a sulfur atom, and represents -COO-, -COO (R5)-, -COS-, -COS (R5)-, -CON ( R6)-, -CON (R6) (R5)-and the like are preferable. Here, R5 represents an alkyl group having 1 to 8 carbon atoms, R6 represents a hydrogen atom, and an alkyl group having 1 to 8 carbon atoms. n represents an integer of 1 to 18, more preferably 4 to 12, still more preferably 6 to 8, and most preferably 6.
In addition, two or more kinds of polymerization units of the fluoroaliphatic group-containing monomer represented by the general formula [1] may be included in the fluorine-based leveling agent as structural units.

In the general formula [2], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, more preferably a hydrogen atom or a methyl group. X represents an oxygen atom, a sulfur atom or —N (R ² ) —, more preferably an oxygen atom or —N (R ² ) —, and still more preferably an oxygen atom. R ² represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and still more preferably a hydrogen atom or a methyl group. m represents an integer of 1 to 6, more preferably 1 to 3, and still more preferably 1. n represents an integer of 1 to 18, more preferably 4 to 12, still more preferably 6 to 8, and most preferably 6.
In addition, two or more kinds of polymerization units of the fluoroaliphatic group-containing monomer represented by the general formula [2] may be included in the fluorine-based leveling agent as structural units.

  Specific examples of the fluoroaliphatic group-containing monomer represented by the general formula [1] or [2] are shown below, but the present invention is not limited thereto.

In the general formula [3], R ³ represents a hydrogen atom, a halogen atom or a methyl group, more preferably a hydrogen atom or a methyl group. L ² represents a divalent coupler, and a divalent coupler containing an oxygen atom, a sulfur atom, or a nitrogen atom is preferable. L ² represents a divalent linking group containing any one of an oxygen atom, a nitrogen atom, and a sulfur atom, and —COO—, —COO (R5) —, —COS—, —COS (R5) —, —CON (R6)-, -CON (R6) (R5)-and the like are preferable. Here, R5 represents an alkyl group having 1 to 8 carbon atoms, R6 represents a hydrogen atom, and an alkyl group having 1 to 8 carbon atoms. n represents an integer of 1 or more and 6 or less, more preferably 4 to 6, and still more preferably 6.
Two or more kinds of polymer units of the fluoroaliphatic group-containing monomer represented by the general formula [3] may be included as a structural unit in the fluoroaliphatic group-containing copolymer.

In the general formula [4], R ⁴ represents a hydrogen atom, a halogen atom or a methyl group, more preferably a hydrogen atom or a methyl group. X represents an oxygen atom, a sulfur atom or —N (R ² ) —, more preferably an oxygen atom or —N (R ² ) —, and still more preferably an oxygen atom. R ² represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and still more preferably a hydrogen atom or a methyl group. m represents an integer of 1 to 6, more preferably 1 to 3, and still more preferably 1. n represents an integer of 1 or more and 6 or less, more preferably 4 to 6, and still more preferably 6. Two or more kinds of polymer units of the fluoroaliphatic group-containing monomer represented by the general formula [4] may be contained as a structural unit in the fluoroaliphatic group-containing copolymer.

  Although the example of the more specific monomer of the fluoro aliphatic group containing monomer represented by General formula [3] or [4] is given below, this invention is not limited to these.

  In addition, some of the fluorinated chemical products produced by the electrolytic fluorination method that has been favorably used in the past are substances that have low biodegradability and high bioaccumulation. There is concern about toxicity and developmental toxicity. Also in the present invention, a fluorine leveling agent having a hydrogen atom at the end of the fluoroaliphatic group and a fluorine atom at the end and a short fluoroalkyl chain length of C6 or less is a more environmentally safe substance. It can be said that it is an advantage.

The repeating unit corresponding to the monomer B represented by the general formula [5] that does not contain a fluoroaliphatic group will be described. In the general formula [5], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, more preferably a hydrogen atom or a methyl group. L ¹ represents a divalent linking group, Y is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aromatic group which may have a substituent. Represents. L ¹ represents a divalent linking group containing any of an oxygen atom, a nitrogen atom, and a sulfur atom, and represents —COO—, —COO (R5) —, —COS—, —COS (R5) —, —CON (R6)-, -CON (R6) (R5)-and the like are preferable. Here, R5 represents an alkyl group having 1 to 8 carbon atoms, R6 represents a hydrogen atom, and an alkyl group having 1 to 8 carbon atoms.

  In the present invention, the amount of repeating units corresponding to the monomer B represented by the general formula [5] having an I / O value of 1.0 or more is the total number of polymerized units constituting the fluoroaliphatic group-containing copolymer Is preferably 5% by mass or less, more preferably 3% by mass or less, and most preferably 0% by mass. In particular, it is preferable not to include poly (oxyalkylene) acrylate and / or poly (oxyalkylene) methacrylate as a repeating unit corresponding to the monomer represented by the general formula [5].

The above I / O value described in the present invention is determined by the method described in Satoshi Fujita “Organicity: Organic Concept by Inorganic Value”, Yoshio Koda “Organic Conceptual Diagram” Sankyo Publishing (1984) and the like. ) / Organic (O) ”value. The I / O value is used as a means for predicting various physicochemical properties of organic compounds. Organicity can be obtained by comparing the number of carbons, and inorganicity can be obtained by comparing the boiling points of hydrocarbons having the same number of carbons. For example, one (—CH ₂ —) (actually C) is determined to have an organic value of 20, and the inorganic property is determined to have an inorganic value of 100 from the influence of hydroxyl groups (—OH) on the boiling point. What calculated | required the value of the other substituent (inorganic group) on the basis of the inorganic value 100 of this (-OH) is shown as "inorganic group table". According to this inorganic group table, the ratio I / O between the inorganic value (I) and the organic value (O) obtained for each molecule is defined as “I / O value”. It shows that the hydrophilicity increases as the I / O value increases, and the hydrophobicity increases as the I / O value decreases.

  A fluorine-based leveling agent containing a highly hydrophilic monomer as a repeating unit corresponding to the monomer represented by the general formula [5] has poor elution to the upper layer when the upper layer is applied, and deteriorates scratch resistance. When poly (oxyalkylene) acrylate and / or poly (oxyalkylene) methacrylate is used as a repeating unit corresponding to the monomer represented by the general formula [5], the scratch resistance is particularly deteriorated. preferable. Therefore, it is preferable to employ only a hydrophobic monomer as a repeating unit corresponding to the monomer represented by the general formula [5]. The hydrophobic monomer is preferably a monomer having a cyclic compound as Y in the general formula [5], more preferably an alicyclic compound, and still more preferably an alicyclic condensed ring compound. The alicyclic as used herein is a compound that does not belong to an aromatic compound among carbocyclic compounds having a structure in which carbon atoms are cyclically bonded, and a condensed ring compound is an organic compound having a cyclic structure. Two or more rings are bonded by sharing two or more atoms (Chemical Dictionary, Kyoritsu Shuppan Co., Ltd.).

  Although the example of the more specific monomer of the monomer represented by General formula [5] of this invention is given below, it is not this limitation.

5000-50000 is preferable, as for the mass average molecular weight of the fluorine-type leveling agent used by this invention, 8000-30000 is more preferable, and 10000-20000 is still more preferable. When the molecular weight is 5,000 or less, the ability to prevent wind unevenness is insufficient, and when the molecular weight exceeds 50,000, the solubility and elution in an organic solvent is lowered, which is not preferable.
Here, the mass average molecular weight and the molecular weight are converted to polystyrene by GTH analyzer using a column of TSKgel GMHxL, TSKgel G4000HxL, TSKgel G2000HxL (both trade names manufactured by Tosoh Co., Ltd.) by detection of solvent THF and differential refractometer. Is the molecular weight.

  The fluorine-based leveling agent of the present invention can be produced by a known and conventional method. For example, the above-mentioned monomers such as (meth) acrylate having a fluoroaliphatic group and (meth) acrylate having a linear, branched or cyclic alkyl group are added to a general-purpose radical polymerization initiator in an organic solvent. Can be produced by polymerization. Alternatively, other addition-polymerizable unsaturated compounds can be added in some cases and produced in the same manner as described above. Depending on the polymerizability of each monomer, a dropping polymerization method in which a monomer and an initiator are added dropwise to a reaction vessel is also effective for obtaining a polymer having a uniform composition.

  Hereinafter, examples of specific structures of the fluorine-based leveling agent that can be used in the present invention are shown, but the present invention is not limited thereto. In addition, the number in a formula shows the mass ratio of each monomer component. Mw represents a mass average molecular weight.

  The amount of the polymer units of the fluoroaliphatic group-containing monomer A represented by the general formulas [1] to [4] constituting the fluoropolymer used in the present invention is the total polymer units constituting the fluoropolymer. Based on this, it is preferably more than 10% by mass, more preferably 20 to 90% by mass, and still more preferably 30 to 80% by mass.

The amount of the fluorine-based leveling agent added to the coating solution is preferably 0.001% by mass to 1.0% by mass, and more preferably 0.01% by mass to 0.2% by mass.
The coating solution preferably has a water content of 30% by mass or less, more preferably 10% by mass or less, from the viewpoint of improving the surface condition.

  The composition of the present invention can contain necessary components such as a binder, an inorganic filler, and a dispersion stabilizer depending on applications. One or more functional layers can be formed by coating one or more coating compositions of the present invention on a support, for example, an antireflection film or a polarizing plate.

Next, the low refractive index layer will be described below.
<Low refractive index layer>
The refractive index of the low refractive index layer in the antireflection film of the present invention is 1.30 to 1.55, preferably 1.35 to 1.45.
When the refractive index is less than 1.30, the antireflection performance is improved, but the mechanical strength of the film is lowered, and when it exceeds 1.55, the antireflection performance is remarkably deteriorated.
Further, the low refractive index layer preferably satisfies the following formula (I) from the viewpoint of reducing the reflectance.
Formula (I)
(M / 4) × 0.7 <n1 × d1 <(m / 4) × 1.3
In the formula, m is a positive odd number, n1 is the refractive index of the low refractive index layer, and d1 is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm.
In addition, satisfy | filling said numerical formula (I) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (I) exists in the said wavelength range.

As the low refractive index layer, a low refractive index layer (embodiment 1) formed by crosslinking of a fluorine-containing resin that is crosslinked by heat or ionizing radiation (hereinafter also referred to as “fluorinated resin before crosslinking”), a low refractive index by a sol-gel method A layer (embodiment 2), and a low refractive index layer (embodiment 3) having voids between or inside the particles using the particles and the binder polymer are used.
A material for forming a low refractive index layer (embodiment 1) composed of a crosslink of a fluorine-containing resin that is crosslinked by heat or ionizing radiation (hereinafter also referred to as “fluorine-containing resin before crosslinking”) will be described below.
The low refractive index layer is a cured film formed, for example, by applying, drying and curing a curable composition containing a fluorine-containing polymer as a main component.
<Fluoropolymer for low refractive index layer>
The fluoropolymer has a cured film with a coefficient of dynamic friction of 0.03 to 0.20, a contact angle with water of 90 to 120 °, and a sliding angle of pure water of 70 ° or less, and heat or ionization. A polymer that is cross-linked by radiation is preferable in terms of improving productivity in the case of coating and curing a roll film while transporting the web.
In addition, when the antireflection film of the present invention is mounted on an image display device, the lower the peel strength from a commercially available adhesive tape, the easier it is to peel off after sticking a seal or memo, so the peel strength is preferably 500 gf or less, 300 gf or less is more preferable, and 100 gf or less is most preferable. Further, the higher the surface hardness measured with a microhardness meter, the harder it is to scratch. Therefore, the surface hardness is preferably 0.3 GPa or more, and more preferably 0.5 GPa or more.

  The fluorine-containing polymer used for the low refractive index layer is a fluorine-containing polymer containing a fluorine atom in a range of 35 to 80% by mass and containing a crosslinkable or polymerizable functional group, for example, containing a perfluoroalkyl group In addition to hydrolysates and dehydration condensates of silane compounds [for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane], fluorinated monomer units and crosslinking reactive units are used as constituent units. A fluorine-containing copolymer is mentioned. In the case of a fluorinated copolymer, the main chain preferably consists of only carbon atoms. That is, it is preferable that the main chain skeleton does not have an oxygen atom or a nitrogen atom.

  Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3- Dioxoles, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, etc. However, perfluoroolefins are preferable, and hexafluoropropylene is particularly preferable from the viewpoint of refractive index, solubility, transparency, availability, and the like.

  Examples of the crosslinking reactive unit include a structural unit obtained by polymerization of a monomer having a self-crosslinking functional group in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether; carboxyl group, hydroxy group, amino group, sulfo group A structural unit obtained by polymerization of a monomer having, for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc. And a structural unit in which a crosslinkable reactive group such as a (meth) acryloyl group is introduced by a polymer reaction (for example, it can be introduced by a technique such as allowing acrylic acid chloride to act on a hydroxy group).

  In addition to the fluorine-containing monomer unit and the cross-linking reactive unit, from the viewpoint of solubility in a solvent, film transparency, and the like, a monomer not containing a fluorine atom is appropriately copolymerized to introduce another polymerization unit. You can also There are no particular limitations on the monomer units that can be used in combination, such as olefins [ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.], acrylic esters [methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2 -Ethylhexyl], methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl) Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.], vinyl esters [vinyl acetate, vinyl propionate, vinyl cinnamate, etc.], acrylamides [N-tertbutylacrylamide, N-silane] B hexyl acrylamide], methacrylamides, and acrylonitrile derivatives.

  As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be appropriately used in combination with the fluoropolymer.

The fluorine-containing polymer particularly useful in the present invention is a random copolymer of perfluoroolefin and vinyl ethers or vinyl esters. In particular, it preferably has a group capable of undergoing crosslinking reaction alone (radical reactive group such as (meth) acryloyl group, ring-opening polymerizable group such as epoxy group and oxetanyl group).
These crosslinkable group-containing polymerized units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymerized units of the polymer.

  A preferred form of the fluorine-containing polymer for the low refractive index layer used in the present invention is a copolymer represented by the general formula 1.

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, It may have a branched structure, may have a ring structure, or may have a heteroatom selected from O, N and S.
Preferred examples include * — (CH ₂ ) ₂ —O — **, * — (CH ₂ ) ₂ —NH — **, * — (CH ₂ ) ₄ —O — **, * — (CH ₂ ). _{6 -O - **, * - (} CH 2) 2 -O- (CH 2) 2 -O - **, * -CONH- (CH 2) 3 -O - **, * -CH 2 CH (OH ) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** (* represents the connecting site on the polymer main chain side, and ** represents the connecting on the (meth) acryloyl group side) Represents a part). m represents 0 or 1;

  In general formula 1, X represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

  In the general formula 1, A represents a repeating unit derived from an arbitrary vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with hexafluoropropylene. Tg (contributes to film hardness), solubility in solvents, transparency, slipperiness, dust / antifouling properties, etc., can be selected as appropriate, depending on the purpose, depending on the single or multiple vinyl monomers It may be configured.

  Preferred examples include methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, vinyl ethers such as allyl vinyl ether, vinyl acetate, vinyl propionate, butyric acid. (Meth) such as vinyl esters such as vinyl, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane Acrylates, styrene, styrene derivatives such as p-hydroxymethylstyrene, crotonic acid, maleic acid, itaconic acid Can be mentioned unsaturated carboxylic acids and derivatives thereof, more preferably ether derivatives, vinyl ester derivatives, particularly preferably a vinyl ether derivative.

x, y, and z represent the mol% of each constituent component, and preferably 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65, and more preferably 35 ≦ x ≦ 55 and 30 ≦ y ≦. 60, 0 ≦ z ≦ 20, particularly preferably 40 ≦ x ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10. However, x + y + z = 100.
A particularly preferred form of the copolymer used in the present invention is General Formula 2.

In General Formula 2, X represents the same meaning as in General Formula 1, and the preferred range is also the same.
n represents an integer of 2 ≦ n ≦ 10, preferably 2 ≦ n ≦ 6, and particularly preferably 2 ≦ n ≦ 4.
B represents a unit of a repeating unit derived from an arbitrary vinyl monomer, and may be composed of a single composition or a plurality of compositions. As an example, what was demonstrated as an example of A in the said General formula 1 is applicable.
x, y, z1 and z2 represent mol% of each repeating unit, and x and y preferably satisfy 30 ≦ x ≦ 60 and 5 ≦ y ≦ 70, respectively, more preferably 35 ≦ x ≦ 55. 30 ≦ y ≦ 60, particularly preferably 40 ≦ x ≦ 55 and 40 ≦ y ≦ 55. z1 and z2 preferably satisfy 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65, more preferably 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10, and 0 ≦ z1 ≦ 10, 0 It is particularly preferable that ≦ z2 ≦ 5. However, x + y + z1 + z2 = 100.
The copolymer represented by the general formula 1 or 2 is obtained, for example, by introducing a (meth) acryloyl group into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any of the above-described methods. Can be synthesized. As the reprecipitation solvent used in this case, isopropanol, hexane, methanol and the like are preferable.
Preferable specific examples of the copolymer represented by the general formula 1 or 2 include those described in [0035] to [0047] of JP-A-2004-45462, and the method described in the publication Can be synthesized.

The curable composition preferably contains (A) the fluoropolymer, (B) inorganic fine particles, and (C) an organosilane compound described later.
<Inorganic fine particles for low refractive index layer>
The amount of the inorganic fine particles is preferably ^{1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . If the amount is too small, the effect of improving the scratch resistance is reduced. It is preferable to be inside.
Since the inorganic fine particles are contained in the low refractive index layer, it is desirable that the inorganic fine particles have a low refractive index. Examples thereof include fine particles of magnesium fluoride and silica. In particular, silica fine particles are preferable in terms of refractive index, dispersion stability, and cost.
The average particle diameter of the inorganic fine particles is preferably 30% or more and 100% or less, more preferably 35% or more and 80% or less, and still more preferably 40% or more and 60% or less of the thickness of the low refractive index layer. That is, when the thickness of the low refractive index layer is 100 nm, the particle size of the silica fine particles is preferably 30 nm to 100 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
If the particle size of the inorganic fine particles is too small, the effect of improving the scratch resistance is reduced. Therefore, it is preferable to be within the above range. The inorganic fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite.
Here, the average particle diameter of the inorganic fine particles is measured by a Coulter counter.

In order to further reduce the increase in the refractive index of the low refractive index layer, the inorganic fine particles preferably have a hollow structure, and the refractive index of the inorganic fine particles is 1.17 to 1.40, more preferably 1. It is 17-1.35, More preferably, it is 1.17-1.30. Here, the refractive index represents the refractive index of the whole particle, and does not represent the refractive index of only the inorganic material of the outer shell in the case of hollow structure inorganic fine particles. At this time, when the radius of the cavity in the particle is a and the radius of the particle outer shell is b, the porosity x represented by the following formula (II) is (formula II)
^{x = (4πa 3/3)} / (4πb 3/3) × 100
Preferably it is 10 to 60%, More preferably, it is 20 to 60%, Most preferably, it is 30 to 60%.
If the refractive index of the hollow inorganic fine particles is made lower and the porosity is increased, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. From the viewpoint of scratch resistance, the refractive index is 1 Particles with a low refractive index of less than .17 do not hold.
The refractive index of the inorganic fine particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

In addition, at least one kind of inorganic fine particles (hereinafter referred to as “small size inorganic fine particles”) having an average particle size of less than 25% of the thickness of the low refractive index layer is referred to as “inorganic fine particles (hereinafter referred to as“ small size inorganic fine particles ”). It may be used in combination with “large-size inorganic fine particles”.
Since the small-sized inorganic fine particles can be present in the gaps between the large-sized inorganic fine particles, they can contribute as a retaining agent for the large-sized inorganic fine particles.
When the low refractive index layer is 100 nm, the average particle size of the small-sized inorganic fine particles is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm. Use of such inorganic fine particles is preferable in terms of raw material costs and a retaining agent effect.
As described above, the inorganic fine particles have an average particle diameter of 30 to 100% of the thickness of the low refractive index layer as described above, have a hollow structure, and have a refractive index of 1.17 to 1. What is 40 is used especially preferably.

Inorganic fine particles are treated with physical surface treatment such as plasma discharge treatment or corona discharge treatment in order to stabilize dispersion in the dispersion or coating solution, or to improve the affinity and binding properties with the binder component. Further, chemical surface treatment with a surfactant, a coupling agent or the like may be performed. Of these, the use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Of these, silane coupling treatment is particularly effective.
The coupling agent is used as a surface treatment agent for the inorganic fine particles of the low refractive index layer in advance for surface treatment prior to the preparation of the layer coating solution, and is further added as an additive during preparation of the layer coating solution. It is preferable to make it contain in a layer.
The inorganic fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.

Next, (C) the organosilane compound will be described.
<Organosilane compound for low refractive index layer>
The curable composition contains a hydrolyzate of an organosilane compound and / or a partial condensate thereof (hereinafter, the obtained reaction solution is also referred to as a “sol component”). In particular, it is preferable in terms of achieving both the antireflection ability and the scratch resistance.
This sol component functions as a binder for the low refractive index layer by applying the curable composition and then condensing in a drying and heating process to form a cured product. Moreover, in this invention, since it has the said fluorine-containing polymer, the binder which has a three-dimensional structure is formed by irradiation of actinic light.
The organosilane compound is preferably represented by the following general formula [A].
Formula [A]
_{^{(R 10) m -Si (X}} ) 4-m
In the general formula [A], R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl and the like. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.
X represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I or the like). ), And R ² COO (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, such as CH ₃ COO, C ₂ H ₅ COO, etc.), preferably An alkoxy group, particularly preferably a methoxy group or an ethoxy group.
m represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.

When R ¹⁰ or X there are a plurality, a plurality of R ¹⁰ or X groups may be different, even the same, respectively.
The substituent contained in R ¹⁰ is not particularly limited, but a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy etc.), aryloxy (phenoxy etc.) ), Alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxy) Carbonyl, etc.), aryloxy Carbonyl groups (phenoxycarbonyl, etc.), carbamoyl groups (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl, etc.), acylamino groups (acetylamino, benzoylamino, acrylicamino, methacrylamino) Etc.), and these substituents may be further substituted.

When there are a plurality of R ^{10 s} , at least one is preferably a substituted alkyl group or a substituted aryl group.
Among the organosilane compounds represented by the general formula [A], an organosilane compound having a vinyl polymerizable substituent represented by the following general formula [B] is preferable.

General formula [B]

In the general formula [B], R ¹ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom and a chlorine atom are preferred, a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom and a chlorine atom are more preferred, and a hydrogen atom and a methyl group Is particularly preferred.
Y represents a single bond or * -COO-**, * -CONH-** or * -O-**, preferably a single bond, * -COO-** or * -CONH-**, * -COO-** is more preferable, and * -COO-** is particularly preferable. * Represents a position bonded to ═C (R ¹ ) —, and ** represents a position bonded to L.

  L represents a divalent linking chain. Specifically, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group having a linking group (for example, ether, ester, amide, etc.) inside, and a linking group inside. A substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an alkylene group having a linking group therein is preferred, an unsubstituted alkylene group, an unsubstituted arylene group Further, an alkylene group having an ether or ester linking group inside is more preferable, an unsubstituted alkylene group, and an alkylene group having an ether or ester linking group inside is particularly preferable. Examples of the substituent include a halogen, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group, and these substituents may be further substituted.

n represents 0 or 1. When there are a plurality of Xs, the plurality of Xs may be the same or different. n is preferably 0.
R ¹⁰ has the same meaning as in formula [A], preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and more preferably an unsubstituted alkyl group or an unsubstituted aryl group.
X has the same meaning as in the general formula [A], preferably a halogen atom, a hydroxyl group or an unsubstituted alkoxy group, more preferably a chlorine atom, a hydroxyl group or an unsubstituted alkoxy group having 1 to 6 carbon atoms, a hydroxyl group or a carbon number of 1 -3 alkoxy groups are more preferred, and methoxy groups are particularly preferred.

  Two or more compounds of the general formula [A] and general formula [B] may be used in combination. Although the specific example of a compound represented by general formula [A] and general formula [B] is shown below, it is not limited.

  Of these, (M-1), (M-2), and (M-5) are particularly preferable.

  The hydrolyzate and / or partial condensate of the organosilane compound is generally produced by treating the organosilane compound in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples thereof include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium; metal chelate compounds having a metal such as Zr, Ti or Al as a central metal. In the present invention, it is preferable to use a metal chelate compound, an acid catalyst of inorganic acids and organic acids. Inorganic acids are preferably hydrochloric acid and sulfuric acid, and organic acids are preferably those having an acid dissociation constant (pKa value (25 ° C.)) of 4.5 or less in water, and further, acid dissociation constants in hydrochloric acid, sulfuric acid and water. Is preferably an organic acid having an acid dissociation constant of 2.5 or less in hydrochloric acid, sulfuric acid or water, more preferably an organic acid having an acid dissociation constant of 2.5 or less in water. Specifically, methanesulfonic acid, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

As the metal chelate compound, (wherein, R ³ represents an alkyl group having 1 to 10 carbon atoms) Formula R ³ OH alcohol and R ⁴ COCH ₂ COR ⁵ (formula represented by, R ⁴ is the number of carbon atoms 1 to 10 alkyl groups, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or a compound represented by an alkoxy group having 1 to 10 carbon atoms), and is selected from Zr, Ti, and Al. Any metal having a central metal as the metal can be used without any particular limitation. Within this category, two or more metal chelate compounds may be used in combination. The metal chelate compound used in the present invention has the general formula Zr (OR ³ ) _p1 (R ⁴ COCHCOR ⁵ ) _p2 , Ti (OR ³ ) _q1 (R ⁴ COCHCOR ⁵ ) _q2 , and Al (OR ³ ) _r1 (R ⁴ Those selected from the group of compounds represented by COCHCOR ⁵ ) _r2 are preferred and serve to promote the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound.
R ³ and R ⁴ in the metal chelate compound may be the same or different and each is an alkyl group having 1 to 10 carbon atoms, specifically, an ethyl group, n-propyl group, i-propyl group, n-butyl group, sec -Butyl group, t-butyl group, n-pentyl group, phenyl group and the like. R ⁵ represents an alkyl group having 1 to 10 carbon atoms as described above, or an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and n-butoxy. Group, sec-butoxy group, t-butoxy group and the like. Moreover, p1, p2, q1, q2, r1, and r2 in the metal chelate compound represent integers determined so as to be p1 + p2 = 4, q1 + q2 = 4, and r1 + r2 = 3, respectively.

Specific examples of these metal chelate compounds include tri-n-butoxyethylacetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n-propylacetate). Zirconium chelate compounds such as acetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium, diiso Titanium chelate compounds such as propoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum, diisopropyl Poxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonate) aluminum, monoacetylacetonate bis (ethyl) An aluminum chelate compound such as acetoacetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonate) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

  In the present invention, it is preferable that a β-diketone compound and / or a β-ketoester compound is further added to the curable composition. This will be further described below.

The β-diketone compound and / or β-ketoester compound represented by the general formula R ⁴ COCH ₂ COR ⁵ is used in the present invention, and is used as a stability improver for the curable composition used in the present invention. It works. Here, R ⁴ represents an alkyl group having 1 to 10 carbon atoms, and R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. That is, by coordinating with a metal atom in the metal chelate compound (zirconium, titanium and / or aluminum compound), the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound by these metal chelate compounds is performed. It is considered that the promoting action is suppressed and the storage stability of the resulting composition is improved. R ⁴ and R ⁵ constituting the β- diketone compound and / or β- ketoester compound are the same as R ⁴ and R ⁵ constituting the metal chelate compound.

  Specific examples of the β-diketone compound and / or β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate-n-butyl, acetoacetate. Acetic acid-sec-butyl, acetoacetic acid-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4-octane-dione, 2,4-nonane -Dione, 5-methyl-hexane-dione and the like can be mentioned. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred. These β-diketone compounds and / or β-ketoester compounds may be used alone or in combination of two or more. In the present invention, the β-diketone compound and / or β-ketoester compound is preferably used in an amount of 2 mol or more, more preferably 3 to 20 mol, per 1 mol of the metal chelate compound. If it is less than 2 mol, the storage stability of the resulting composition may be inferior, which is not preferable.

The compounding amount of the organosilane compound is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass, and most preferably 1 to 10% by mass based on the total solid content of the low refractive index layer.
The organosilane compound may be added directly to the curable composition (coating solution for anti-glare layer, low refractive index layer, etc.), but the organosilane compound is treated in the presence of a catalyst in advance to prepare the organosilane compound. It is preferable to prepare a hydrolyzate and / or partial condensate of a silane compound and prepare the curable composition using the obtained reaction solution (sol solution). In the present invention, first, the organosilane compound A composition containing a hydrolyzate and / or a partial condensate and a metal chelate compound is prepared, and a liquid obtained by adding a β-diketone compound and / or a β-ketoester compound thereto is added to at least an antiglare layer or a low refractive index layer. It is preferable to coat it in a single layer coating solution.

  5-100 mass% is preferable, the usage-amount of the sol component of the organosilane with respect to a fluorine-containing polymer in a low refractive index layer has more preferable 5-40 mass%, 8-35 mass% is still more preferable, 10-30 mass % Is particularly preferred. If the amount used is small, it is difficult to obtain the effect of the present invention, and if the amount used is too large, the refractive index increases or the shape / surface shape of the film deteriorates.

  An inorganic filler other than the above-described inorganic fine particles can be added to the curable composition in an addition amount within a range that does not impair the desired effect of the present invention. Details of the inorganic filler will be described later.

[Other substances contained in curable composition for low refractive index layer]
The curable composition comprises the above-mentioned (A) fluorine-containing polymer, (B) inorganic fine particles and (C) an organosilane compound, if necessary, various additives and a radical polymerization initiator and a cationic polymerization initiator described later. It is prepared by adding them and further dissolving them in a suitable solvent. At this time, the concentration of the solid content is appropriately selected according to the use, but is generally about 0.01 to 60% by mass, preferably 0.5 to 50% by mass, particularly preferably 1% to 20% by mass. %.

  Curing agents such as polyfunctional (meth) acrylate compounds, polyfunctional epoxy compounds, polyisocyanate compounds, aminoplasts, polybasic acids or anhydrides thereof from the viewpoint of interfacial adhesion with the lower layer directly in contact with the low refractive index layer Can also be added in small amounts. When adding these, it is preferable to set it as the range of 30 mass% or less with respect to the total solid of a low-refractive-index layer film, It is more preferable to set it as the range of 20 mass% or less, The range of 10 mass% or less It is particularly preferable that

  In addition, for the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipping properties, a known silicone compound or fluorine compound antifouling agent, slipping agent, and the like may be appropriately added. When these additives are added, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass.

  Preferable examples of the silicone compound include those having a substituent at the terminal and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferred silicone compounds are X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821 (named above), Chisso Corporation, FM-0725, FM-7725, FM-4421, FM-5521, FM6621, FM-1121, Gelest DMS-U22, RMS-033, RMS- 083, UMS-182, DMS-H21, DMS-H31, HMS-301, FMS121, FMS123, FMS131, FMS141, FMS221 (named above) but not limited thereto.

As the fluorine compound, a compound having a fluoroalkyl group is preferable. The fluoroalkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and a straight chain (for example, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ) ₄ H, etc.), even branched structures (eg, —CH (CF ₃ ) ₂ , —CH ₂ CF (CF ₃ ) ₂ , —CH (CH ₃ ) CF ₂ CF ₃ , —CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H, etc.), but alicyclic structures (preferably 5-membered or 6-membered rings such as perfluorocyclohexyl groups) , A perfluorocyclopentyl group or an alkyl group substituted with these, and may have an ether bond (for example, —CH ₂ OCH ₂ CF ₂ CF ₃ , —CH ₂ CH ₂ OCH ₂ C). ₄ F ₈ H, —CH ₂ CH ₂ OCH ₂ CH ₂ C ₈ F ₁₇ , —CH ₂ C H ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ H, etc.). A plurality of the fluoroalkyl groups may be contained in the same molecule.
It is preferable that the fluorine-based compound further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink, Megafac F-171. , F-172, F-179A, Defender MCF-300 (trade name) and the like, but are not limited thereto.

  For the purpose of imparting properties such as dust resistance and antistatic properties, a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, or the like can be appropriately added. These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass, more preferably in the range of 0.05 to 10% by mass of the total solid content of the low n layer. Particularly preferably 0.1 to 5% by mass. Examples of preferred compounds include, but are not limited to, Dainippon Ink Co., Ltd., MegaFace F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

[Solvent for low refractive index layer]
As a solvent used in the coating composition for forming the low refractive index layer of the present invention, it is possible to dissolve or disperse each component, to easily form a uniform surface in the coating process and the drying process, and liquid storage stability. Can be used, and various solvents selected from the viewpoints of having an appropriate saturated vapor pressure can be used. From the viewpoint of the drying load, it is preferable that a solvent having a boiling point of 100 ° C. or lower at normal pressure and room temperature as a main component and a small amount of a solvent having a boiling point of 100 ° C. or higher for adjusting the drying speed.
Examples of the solvent having a boiling point of 100 ° C. or lower include hydrocarbons such as hexane (boiling point 68.7 ° C.), heptane (98.4 ° C.), cyclohexane (80.7 ° C.), benzene (80.1 ° C.), Halogenated carbonization such as dichloromethane (39.8 ° C), chloroform (61.2 ° C), carbon tetrachloride (76.8 ° C), 1,2-dichloroethane (83.5 ° C), trichloroethylene (87.2 ° C) Hydrogens, diethyl ether (34.6 ° C), diisopropyl ether (68.5 ° C), dipropyl ether (90.5 ° C), ethers such as tetrahydrofuran (66 ° C), ethyl formate (54.2 ° C), Esters such as methyl acetate (57.8 ° C.), ethyl acetate (77.1 ° C.), isopropyl acetate (89 ° C.), acetone (56.1 ° C.), 2-butanone (methyl ethyl) Ketones such as Luketone, 79.6 ° C, methanol (64.5 ° C), ethanol (78.3 ° C), 2-propanol (82.4 ° C), 1-propanol (97.2 ° C), etc. Alcohols, cyano compounds such as acetonitrile (81.6 ° C.), propionitrile (97.4 ° C.), carbon disulfide (46.2 ° C.), and the like. Of these, ketones and esters are preferable, and ketones are particularly preferable. Among the ketones, 2-butanone is particularly preferable.
Examples of the solvent having a boiling point of 100 ° C. or more include, for example, octane (125.7 ° C.), toluene (110.6 ° C.), xylene (138 ° C.), tetrachloroethylene (121.2 ° C.), and chlorobenzene (131.7 ° C.). , Dioxane (101.3 ° C), dibutyl ether (142.4 ° C), isobutyl acetate (118 ° C), cyclohexanone (155.7 ° C), 2-methyl-4-pentanone (same as MIBK, 115.9 ° C) 1-butanol (117.7 ° C.), N, N-dimethylformamide (153 ° C.), N, N-dimethylacetamide (166 ° C.), dimethyl sulfoxide (189 ° C.) and the like. Cyclohexanone and 2-methyl-4-pentanone are preferable.

The low refractive index layer (Aspect 2) by the sol-gel method will be described.
Various sol-gel materials can also be used as the material for the low refractive index layer. As such a sol-gel material, metal alcoholates (alcohols such as silane, titanium, aluminum, and zirconium), organoalkoxy metal compounds, and hydrolysates thereof can be used. In particular, alkoxysilane, organoalkoxysilane and its hydrolyzate are preferable. Examples of these include tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, etc.), alkyltrialkoxysilane (methyltrimethoxysilane, ethyltrimethoxysilane, etc.), aryltrialkoxysilane (phenyltrimethoxysilane, etc.), dialkyl. Examples thereof include dialkoxysilane and diaryl dialkoxysilane. In addition, organoalkoxysilanes having various functional groups (vinyl trialkoxysilane, methylvinyl dialkoxysilane, γ-glycidyloxypropyltrialkoxysilane, γ-glycidyloxypropylmethyl dialkoxysilane, β- (3,4-epoxy) Dicyclohexyl) ethyltrialkoxysilane, γ-methacryloyloxypropyltrialkoxysilane, γ-aminopropyltrialkoxysilane, γ-mercaptopropyltrialkoxysilane, γ-chloropropyltrialkoxysilane, etc.), perfluoroalkyl group-containing silane compounds ( For example, it is also preferable to use (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, etc.). In particular, the use of a fluorine-containing silane compound is preferable in terms of lowering the refractive index of the layer and imparting water and oil repellency.

  As the low refractive index layer, it is also preferable to use a layer formed by using inorganic or organic fine particles and forming microvoids between or within the fine particles. The average particle diameter of the fine particles is preferably from 0.5 to 200 mm, more preferably from 1 to 100 nm, further preferably from 3 to 70 nm, and most preferably from 5 to 40 nm. The particle diameter of the fine particles is preferably as uniform (monodispersed) as possible.

  The inorganic fine particles are preferably amorphous. The inorganic fine particles are preferably made of a metal oxide, nitride, sulfide or halide, more preferably a metal oxide or metal halide, and most preferably a metal oxide or metal fluoride. . 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 and Ni are preferred, and Mg, Ca, B and Si are more preferred. An inorganic compound containing two kinds of metals may be used. A particularly preferred inorganic compound is silicon dioxide, ie silica.

The microvoids in the inorganic fine particles can be formed, for example, by cross-linking silica molecules forming the particles. Crosslinking silica molecules reduces the volume and makes the particles porous. (Porous) inorganic fine particles having microvoids are described in the sol-gel method (described in JP-A Nos. 53-112732 and 57-9051) or the precipitation method (APPLIED OPTICS, 27, page 3356 (1988)). ) Can be directly synthesized as a dispersion.
Further, the powder obtained by the drying / precipitation method can be mechanically pulverized to obtain a dispersion. Commercially available porous inorganic fine particles (for example, silicon dioxide sol) may be used. The inorganic fine particles having microvoids are preferably used in a state of being dispersed in an appropriate medium in order to form a low refractive index layer. As the dispersion medium, water, alcohol (eg, methanol, ethanol, isopropyl alcohol) and ketone (eg, methyl ethyl ketone, methyl isobutyl ketone) are preferable.

  The organic fine particles are also preferably amorphous. The organic fine particles are preferably polymer fine particles synthesized by polymerization reaction of monomers (for example, emulsion polymerization method). The organic fine particle polymer preferably contains a fluorine atom. The proportion of fluorine atoms in the polymer is preferably 35 to 80% by mass, and more preferably 45 to 75% by mass. It is also preferable to form microvoids in the organic fine particles by, for example, cross-linking the polymer forming the particles and reducing the volume. In order to crosslink the polymer forming the particles, it is preferable to use 20 mol% or more of the monomer for synthesizing the polymer as a polyfunctional monomer. The ratio of the polyfunctional monomer is more preferably 30 to 80 mol%, and most preferably 35 to 50 mol%. Examples of the monomer used for the synthesis of the organic fine particles include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene) as examples of monomers containing fluorine atoms used to synthesize fluorine-containing polymers. , Perfluoro-2,2-dimethyl-1,3-dioxole), fluorinated alkyl esters of acrylic acid or methacrylic acid, and fluorinated vinyl ethers. A copolymer of a monomer containing a fluorine atom and a monomer not containing a fluorine atom may be used. Examples of monomers that do not contain a fluorine atom include olefins (eg, ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride), acrylic esters (eg, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate). , Methacrylate esters (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate), styrenes (eg, styrene, vinyl toluene, α-methyl styrene), vinyl ethers (eg, methyl vinyl ether), vinyl esters ( Examples include vinyl acetate, vinyl propionate), acrylamides (eg, N-tert-butylacrylamide, N-cyclohexylacrylamide), methacrylamides and acrylonitriles. Examples of polyfunctional monomers include dienes (eg, butadiene, pentadiene), esters of polyhydric alcohols and acrylic acid (eg, ethylene glycol diacrylate, 1,4-cyclohexane diacrylate, dipentaerythritol hexaacrylate), Esters of polyhydric alcohol and methacrylic acid (eg, ethylene glycol dimethacrylate, 1,2,4-cyclohexanetetramethacrylate, pentaerythritol tetramethacrylate), divinyl compounds (eg, divinylcyclohexane, 1,4-divinylbenzene), divinyl Examples include sulfones, bisacrylamides (eg, methylene bisacrylamide) and bismethacrylamides.

  Microvoids between particles can be formed by stacking at least two fine particles. When spherical particles having the same particle diameter (completely monodispersed) are closely packed, microvoids between particles having a porosity of 26% by volume are formed. When spherical fine particles having the same particle diameter are simply filled with cubic particles, microvoids between fine particles having a porosity of 48% by volume are formed. In an actual low-refractive index layer, the particle size distribution of fine particles and intra-particle microvoids exist, so the porosity varies considerably from the above theoretical value. When the porosity is increased, the refractive index of the low refractive index layer is lowered. By stacking microparticles to form microvoids and adjusting the particle size of microparticles, the size of interparticle microvoids can be easily adjusted to an appropriate value (does not scatter light and cause problems in the strength of the low refractive index layer). Can be adjusted. Furthermore, by making the particle diameters of the fine particles uniform, it is possible to obtain an optically uniform low refractive index layer in which the size of the microvoids between particles is uniform. As a result, the low refractive index layer is microscopically a microvoided porous film, but can be optically or macroscopically uniform. The interparticle microvoids are preferably closed in the low refractive index layer by fine particles and a polymer. The closed air gap also has an advantage that light scattering on the surface of the low refractive index layer is less than that of an opening opened on the surface of the low refractive index layer.

  By forming the microvoids, the macroscopic refractive index of the low refractive index layer becomes lower than the sum of the refractive indexes of the components constituting the low refractive index layer. The refractive index of the layer is the sum of the refractive indices per volume of the layer components. The refractive index of the constituent component of the low refractive index layer such as fine particles or polymer is larger than 1, whereas the refractive index of air is 1.00. Therefore, a low refractive index layer having a very low refractive index can be obtained by forming microvoids.

  The low refractive index layer preferably contains the polymer in an amount of 5 to 50% by mass. The polymer has a function of adhering fine particles and maintaining the structure of a low refractive index layer including voids. The amount of the polymer used is adjusted so that the strength of the low refractive index layer can be maintained without filling the voids. The amount of the polymer is preferably 10 to 30% by mass of the total amount of the low refractive index layer. In order to adhere the fine particles with the polymer, (1) the polymer is bonded to the surface treatment agent of the fine particles, (2) the fine particles are used as a core, and a polymer shell is formed around the fine particles. It is preferable to use a polymer as the binder. The polymer to be bonded to the surface treatment agent (1) is preferably the shell polymer (2) or the binder polymer (3). The polymer (2) is preferably formed around the fine particles by a polymerization reaction before preparing the coating solution for the low refractive index layer. The polymer (3) is preferably formed by adding a monomer to the coating solution for the low refractive index layer and performing a polymerization reaction simultaneously with or after the coating of the low refractive index layer. It is preferable to carry out by combining two or all of the above (1) to (3), and to carry out a combination of (1) and (3) or (1) to (3) in combination. Particularly preferred. (1) Surface treatment, (2) shell, and (3) binder will be described sequentially.

(1) Surface treatment It is preferable that the fine particles (particularly inorganic fine particles) are subjected to a surface treatment to improve the affinity with the polymer. The surface treatment can be classified into physical surface treatment such as plasma discharge treatment and corona discharge treatment, and chemical surface treatment using a coupling agent. It is preferable to carry out only chemical surface treatment or a combination of physical surface treatment and chemical surface treatment. As the coupling agent, an organoalkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. When the fine particles are made of silicon dioxide, surface treatment with a silane coupling agent can be carried out particularly effectively. Specific examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane. Methoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxy Propyltriethoxysilane, γ- (β-glycidyloxyethoxy) propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and β-cyanoethyltriethoxysilane are mentioned.

  Examples of silane coupling agents having a disubstituted alkyl group with respect to silicon include dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, and γ-glycidyloxypropylmethyldiethoxysilane. Γ-glycidyloxypropylmethyldimethoxysilane, γ-glycidyloxypropylphenyldiethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldi Ethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethyl Kishishiran, .gamma.-mercaptopropyl methyl diethoxy silane, .gamma.-aminopropyl methyl dimethoxy silane, .gamma.-aminopropyl methyl diethoxy silane, methyl vinyl dimethoxy silane, and methyl vinyl diethoxy silane.

  Among these, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane having a double bond in the molecule Γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxy as those having a disubstituted alkyl group with respect to silicon Silane, methylvinyldimethoxysilane and methylvinyldiethoxysilane are preferred, γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyl Oxypropyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane and γ-methacryloyloxypropylmethyldiethoxysilane are particularly preferred.

  Two or more coupling agents may be used in combination. In addition to the silane coupling agents shown above, other silane couplings may be used. Other silane coupling agents include alkyl esters of orthosilicate (eg, methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, i-propyl orthosilicate, n-butyl orthosilicate, sec-butyl orthosilicate, orthosilicate). Acid t-butyl) and hydrolysates thereof. The surface treatment with the coupling agent can be carried out by adding the coupling agent to the fine particle dispersion and leaving the dispersion at a temperature from room temperature to 60 ° C. for several hours to 10 days. In order to accelerate the surface treatment reaction, inorganic acids (eg, sulfuric acid, hydrochloric acid, nitric acid, chromic acid, hypochlorous acid, boric acid, orthosilicic acid, phosphoric acid, carbonic acid), organic acids (eg, acetic acid, polyacrylic acid, Benzenesulfonic acid, phenol, polyglutamic acid), or salts thereof (eg, metal salts, ammonium salts) may be added to the dispersion.

(2) Shell The polymer forming the shell is preferably a polymer having a saturated hydrocarbon as the main chain. A polymer containing a fluorine atom in the main chain or side chain is preferred, and a polymer containing a fluorine atom in the side chain is more preferred. Polyacrylic acid esters or polymethacrylic acid esters are preferred, and esters of fluorine-substituted alcohols with polyacrylic acid or polymethacrylic acid are most preferred. The refractive index of the shell polymer decreases as the content of fluorine atoms in the polymer increases. In order to lower the refractive index of the low refractive index layer, the shell polymer preferably contains 35 to 80% by mass of fluorine atoms, and more preferably contains 45 to 75% by mass of fluorine atoms. The polymer containing a fluorine atom is preferably synthesized by a polymerization reaction of an ethylenically unsaturated monomer containing a fluorine atom. Examples of ethylenically unsaturated monomers containing fluorine atoms include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole) , Fluorinated vinyl ethers and esters of fluorine-substituted alcohols with acrylic acid or methacrylic acid.

  The polymer forming the shell may be a copolymer composed of a repeating unit containing a fluorine atom and a repeating unit not containing a fluorine atom. The repeating unit containing no fluorine atom is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer containing no fluorine atom. Examples of ethylenically unsaturated monomers that do not contain fluorine atoms include olefins (eg, ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride), acrylic esters (eg, methyl acrylate, ethyl acrylate, acrylic acid 2- Ethylhexyl), methacrylic acid esters (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate), styrene and its derivatives (eg, styrene, divinylbenzene, vinyltoluene, α-methylstyrene), vinyl ether ( Examples, methyl vinyl ether), vinyl esters (eg, vinyl acetate, vinyl propionate, vinyl cinnamate), acrylamide (eg, N-tertbutylacrylamide, N-cyclohexylacrylamide), methacrylamide and Acrylonitrile and the like.

  When the binder polymer (3) described later is used in combination, a crosslinkable functional group may be introduced into the shell polymer to chemically bond the shell polymer and the binder polymer by crosslinking. The shell polymer may have crystallinity. When the glass transition temperature (Tg) of the shell polymer is higher than the temperature at the time of forming the low refractive index layer, it is easy to maintain microvoids in the low refractive index layer. However, if Tg is higher than the temperature at which the low refractive index layer is formed, the fine particles are not fused, and the low refractive index layer may not be formed as a continuous layer (resulting in a decrease in strength). In that case, it is desirable to use a binder polymer (3) described later in combination, and form the low refractive index layer as a continuous layer with the binder polymer. By forming a polymer shell around the fine particles, core-shell fine particles are obtained. The core-shell fine particles preferably contain 5 to 90% by volume of a core composed of inorganic fine particles, and more preferably 15 to 80% by volume. Two or more kinds of core-shell fine particles may be used in combination. Further, inorganic fine particles having no shell and core-shell particles may be used in combination.

(3) Binder The binder polymer is preferably a polymer having a saturated hydrocarbon or polyether as the main chain, and more preferably a polymer having a saturated hydrocarbon as the main chain. The binder polymer is preferably crosslinked. The polymer having a saturated hydrocarbon as the main chain is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer. In order to obtain a crosslinked binder polymer, it is preferable to use a monomer having two or more ethylenically unsaturated groups. Examples of monomers having two or more ethylenically unsaturated groups include esters of polyhydric alcohols and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-dichlorohexane diacrylate, pentaerythritol). Tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate , Pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its derivatives Examples include 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. Can be mentioned. The polymer having a polyether as the main chain is preferably synthesized by a ring-opening polymerization reaction of a polyfunctional epoxy compound.

Instead of or in addition to the monomer having two or more ethylenically unsaturated groups, a crosslinked structure may be introduced into the binder polymer by the reaction of a crosslinkable group.
Examples of crosslinkable functional groups include isocyanate groups, epoxy groups, aziridine groups, oxazoline groups, aldehyde groups, carbonyl groups, hydrazine groups, carboxyl groups, methylol groups, and active methylene groups. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. In the present invention, the cross-linking group is not limited to the above compound, and may be one showing reactivity as a result of decomposition of the functional group. As the polymerization initiator used for the polymerization reaction and the crosslinking reaction of the binder polymer, a thermal polymerization initiator or a photopolymerization initiator is used, and a photopolymerization initiator is more preferable. Examples of photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds , Fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone. Examples of benzoins include benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  The binder polymer is preferably formed by adding a monomer to the coating solution for the low refractive index layer, and at the same time as or after coating the low refractive index layer, by a polymerization reaction (if necessary, a crosslinking reaction). Even if a small amount of polymer (eg, polyvinyl alcohol, polyoxyethylene, polymethyl methacrylate, polymethyl acrylate, diacetyl cellulose, triacetyl cellulose, nitrocellulose, polyester, alkyd resin) is added to the coating solution for the low refractive index layer Good.

[Application method]
The antireflection film of the present invention can be formed by the following method, but is not limited to this method.
First, a coating solution containing components for forming each layer is prepared. Next, a coating solution for forming each layer is applied on the transparent support by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method or a die coating method, Although heated and dried, the gravure coating method, the wire bar coating method, and the die coating method are more preferable, and the die coating method is particularly preferable. Further, it is most preferable to perform coating using a die having a devised structure as described in JP-A-2003-200097, JP-A-2003-211052, and the like. Thereafter, the solvent is removed in the drying step. As the drying process, it is preferable to provide a drying zone immediately after coating and to set a drying process for controlling the drying speed by controlling the environment in the drying zone. It is more preferable to install a drying process in which a drying apparatus for precisely removing the solvent in the coating liquid is provided, as described in Kai 2003-93954 and JP-A 2003-106767.
Thereafter, the monomer for forming each layer is polymerized and cured by light irradiation or heating. Thereby, each layer is formed.
For example, if the coating film is UV curable, it is to cure each layer by irradiating an irradiation amount of ultraviolet rays of 10mJ / cm ² ~1000mJ / cm ² by an ultraviolet lamp preferred. At that time, the irradiation distribution in the width direction of the web is preferably 50 to 100%, more preferably 80 to 100%, including both ends with respect to the central maximum irradiation. Further, when it is necessary to purge nitrogen gas or the like to lower the oxygen concentration in order to promote surface hardening, the oxygen concentration is preferably 0.01% to 5%, and the distribution in the width direction is 2% or less in terms of oxygen concentration. Is preferred.

  Further, when the curing rate (100-residual functional group content) of the antiglare layer becomes a certain value of less than 100%, the low refractive index layer of the present invention is provided on the antiglare layer to reduce the amount by ionizing radiation and / or heat. When the refractive index layer is cured, if the curing rate of the lower antiglare layer is higher than before the low refractive index layer is provided, the adhesion between the antiglare layer and the low refractive index layer is improved, which is preferable.

The antireflection film of the present invention produced as described above can be used as a surface film of various known display materials with a known pressure-sensitive adhesive, or used for a liquid crystal display device by creating a polarizing plate using this. Can be used. In this case, it arrange | positions on the outermost surface of a display by providing an adhesive layer on one side. The antireflection film of the present invention is preferably used for at least one of the two protective films sandwiching the polarizing film in the polarizing plate from both sides.
Since the antireflection film of the present invention also serves as a protective film, the production cost of the polarizing plate can be reduced. Further, by using the antireflection film of the present invention as the outermost layer, reflection of external light and the like can be prevented, and a polarizing plate having excellent scratch resistance, antifouling property and the like can be obtained.

  When producing a polarizing plate using the antireflection film of the present invention as one of the surface protective films of two polarizing films, the antireflection film is on the side opposite to the side having the antireflection structure. It is preferable to improve the adhesion on the adhesive surface by hydrophilizing the surface of the transparent support, that is, the surface to be bonded to the polarizing film.

[Saponification]
(1) Method of immersing in alkaline solution This is a method of saponifying all surfaces that are reactive with alkali on the entire surface of the film by immersing a light scattering film or antireflection film in an alkaline solution under appropriate conditions. Since no special equipment is required, it is preferable from the viewpoint of cost. The alkaline liquid is preferably a sodium hydroxide aqueous solution. A preferred concentration is 0.5 to 3 mol / L, particularly preferably 1 to 2 mol / L. The liquid temperature of a preferable alkali liquid is 30-75 degreeC, Most preferably, it is 40-60 degreeC.
The combination of the saponification conditions is preferably a combination of relatively mild conditions, but can be set according to the material and configuration of the light scattering film and the antireflection film, and the target contact angle.
After being immersed in the alkaline solution, it is preferable to sufficiently wash with water or neutralize the alkaline component by immersing in a dilute acid so that the alkaline component does not remain in the film.

By saponification treatment, the surface of the transparent support opposite to the surface having the antiglare layer or antireflection layer is hydrophilized. The protective film for polarizing plate is used by adhering the hydrophilic surface of the transparent support to the polarizing film.
The hydrophilized surface is effective for improving the adhesiveness with the adhesive layer mainly composed of polyvinyl alcohol.
In the saponification treatment, the lower the contact angle to water on the surface of the transparent support opposite to the side having the antiglare layer or the low refractive index layer, the better from the viewpoint of adhesiveness to the polarizing film. At the same time, since it is damaged by alkali from the surface having the antiglare layer and the low refractive index layer to the inside, it is important to set the necessary minimum reaction conditions. When the contact angle to water of the transparent support on the opposite surface is used as an index of damage to each layer due to alkali, particularly when the transparent support is triacetylcellulose, preferably 10 to 50 degrees, more preferably Is 30 to 50 degrees, more preferably 40 to 50 degrees. If it is 50 degrees or more, there is a problem in the adhesion to the polarizing film, which is not preferable. On the other hand, if it is less than 10 degrees, the damage received by the antireflection film is too large, and physical strength is impaired, which is not preferable.

(2) Method of applying alkaline solution As a means of avoiding damage to each film in the above immersion method, the alkaline solution is applied only to the surface opposite to the surface having the antiglare layer or antireflection film under appropriate conditions. An alkaline solution coating method of heating, washing with water and drying is preferably used. The application in this case means that an alkaline solution or the like is brought into contact only with the surface to be saponified, and in addition to the application, spraying, contact with a belt containing the solution, or the like may be performed. Including. By adopting these methods, a separate facility and process for applying an alkaline solution are required, which is inferior to the immersion method (1) from the viewpoint of cost. On the other hand, since the alkali solution contacts only the surface to be saponified, the opposite surface can have a layer using a material that is weak against the alkali solution. For example, vapor deposition films and sol-gel films have various effects such as corrosion, dissolution, and peeling due to alkali solution, so it is not desirable to use the immersion method. Is possible.

  In any of the saponification methods (1) and (2), since each layer can be formed after being unwound from a roll-shaped support, in addition to the light scattering film and antireflection film manufacturing steps described above, A series of operations may be performed. Furthermore, the polarizing plate can be produced more efficiently than the same operation with a single wafer by continuously performing the pasting step with the polarizing plate made of the unwound support.

(3) Method of protecting and saponifying an antiglare layer and an antireflection layer with a laminate film As in the case of (2), when the antiglare layer and / or the low refractive index layer is insufficient in resistance to an alkaline solution. Then, after forming the final layer, the laminate film is bonded to the surface on which the final layer is formed and then immersed in an alkaline solution to hydrophilize only the side of the triacetyl cellulose opposite to the surface on which the final layer has been formed. After being laminated, the laminate film can be peeled off. Even in this method, only the surface opposite to the surface on which the final layer of the triacetyl cellulose film is formed is subjected to the hydrophilization treatment necessary for the polarizing plate protective film without damaging the antiglare layer and the low refractive index layer. Can do. Compared with the method (2), the laminate film is generated as waste, but there is an advantage that a device for applying a special alkaline solution is unnecessary.

(4) Method of immersing in alkaline solution after forming up to antiglare layer Up to antiglare layer is resistant to alkaline solution, but when low refractive index layer is insufficiently resistant to alkaline solution, after forming up to antiglare layer It is also possible to soak both surfaces in an alkali solution to hydrophilize both surfaces, and then form a low refractive index layer on the antiglare layer. Although the manufacturing process becomes complicated, there is an advantage that the interlayer adhesion between the antiglare layer and the low refractive index layer is improved particularly when the low refractive index layer has a hydrophilic group such as a fluorine-containing sol-gel film.

(5) Method of forming an antiglare layer or an antireflection layer on a previously saponified triacetyl cellulose film Saponification is performed by immersing a triacetyl cellulose film in an alkaline solution in advance, either directly or on the other side. An antiglare layer and a low refractive index layer may be formed through the layers. In the case of saponification by dipping in an alkaline solution, interlayer adhesion between the antiglare layer or other layers and the triacetyl cellulose surface hydrophilized by saponification may deteriorate. In such a case, after saponification, only the surface on which the antiglare layer or other layer is formed is treated with corona discharge, glow discharge, etc. to remove the hydrophilic surface, and then the antiglare layer or other layer is removed. It can be dealt with by forming. Further, when the antiglare layer or other layer has a hydrophilic group, the interlayer adhesion may be good.

Below, the polarizing plate using the light-scattering film or antireflection film of this invention and the liquid crystal display device using this polarizing plate are demonstrated.
[Polarizer]
The preferable polarizing plate of this invention has the light-scattering film or antireflection film of this invention as at least one of the protective film (protective film for polarizing plates) of a polarizing film. As described above, the polarizing plate protective film has a water contact angle of 10 degrees on the surface of the transparent support opposite to the side having the antiglare layer or antireflection layer, that is, the surface to be bonded to the polarizing film. It is preferably in the range of ˜50 degrees.
By using the light scattering film or antireflection film of the present invention as a protective film for a polarizing plate, a light scattering function excellent in physical strength, light resistance, or a polarizing plate having an antireflection function can be produced, and a significant cost reduction, The display device can be thinned.
In addition, a polarizing plate is produced using the light scattering film or antireflection film of the present invention as one of the protective films for polarizing plates and an optical compensation film having optical anisotropy described later as the other protective film of the polarizing film. This further improves the visibility and contrast in the bright room of the liquid crystal display device, and makes it possible to produce a polarizing plate that can greatly widen the vertical and horizontal viewing angles.

[Optical compensation layer]
By providing the polarizing plate with an optical compensation layer (retardation layer), the viewing angle characteristics of the liquid crystal display screen can be improved.
As the optical compensation layer, a known layer can be used. However, in terms of widening the viewing angle, the optical compensation layer has a layer having optical anisotropy made of a compound having a discotic structural unit, and is transparent to the discotic compound. An optical compensation layer characterized in that the angle formed with the support varies with the distance from the transparent support.
The angle preferably increases as the distance from the transparent support surface side of the optically anisotropic layer made of the discotic compound increases.
When the optical compensation layer is used as a protective film for a polarizing film, the surface on the side to be bonded to the polarizing film is preferably saponified, and is preferably performed according to the saponifying process.

[Polarizing film]
As the polarizing film, a known polarizing film or a polarizing film cut out from a long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction may be used. A long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction is produced by the following method.
That is, a polarizing film stretched by applying tension while holding both ends of a continuously supplied polymer film by a holding means, stretched at least 1.1 to 20.0 times in the film width direction, The progress of the film is such that the difference between the moving speeds in the longitudinal direction of the holding device is within 3%, and the angle formed by the film moving direction at the exit of the step of holding both ends of the film and the substantial stretching direction of the film is inclined by 20 to 70 °. The film can be produced by a stretching method in which the direction is bent while holding both ends of the film. In particular, those inclined by 45 ° are preferably used from the viewpoint of productivity.

  The method for stretching the polymer film is described in detail in paragraphs 0020 to 0030 of JP-A-2002-86554.

<Liquid crystal display device>
The antiglare antireflection film of the present invention can be applied to an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), or a cathode ray tube display device (CRT). it can. Since the antireflection film of the present invention has a transparent support, the transparent support side is adhered to the image display surface of the image display device.

  When the light scattering film and antireflection film of the present invention are used as one side of the surface protective film of the polarizing film, twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching ( It can be preferably used for a transmissive, reflective, or transflective liquid crystal display device of a mode such as IPS) or optically compensatory bend cell (OCB). In particular, it can be preferably used for VA, IPS, OCB, etc., for applications such as large liquid crystal televisions, and can also be preferably used for TN, STN, etc., if it is used for display devices with small and medium definition. For applications such as large liquid crystal televisions, it is particularly preferable for a display screen having a diagonal of 20 inches or more and a definition of XGA or less (1024 × 768 or less in a display device having an aspect ratio of 3: 4). Can be used. Since the antiglare antireflection film of the present invention has substantially no internal haze, it has a glare for a 20-inch screen with a definition exceeding XGA (1024 × 768 in a display device having an aspect ratio of 3: 4). Since it exceeds the permissible level, it is not preferred when emphasizing glare. Further, since the degree of glare occurs due to the relationship between the size of the pixel and the surface unevenness of the antiglare film on the surface, the definition becomes UXGA (aspect ratio 3 :) when the size of the display device is 30 inches. If it is 40 inches, the definition can be preferably used up to QXGA (2048 × 1536 in a display device with an aspect ratio of 3: 4) or less.

  The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625 (in Japanese Patent Publication No. 176625), and (2) a liquid crystal cell (SID97, Digest of tech. Papers (Proceedings) 28 (1997) 845 in which the VA mode is converted into a multi-domain (for MVA mode) in order to enlarge the viewing angle. ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).

  The OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. It is disclosed in the specifications of Japanese Patent Nos. 45882525 and 5410422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. Therefore, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

  In an ECB mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and is most frequently used as a color TFT liquid crystal display device, and is described in many documents. For example, it is described in “EL, PDP, LCD display” published by Toray Research Center (2001).

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these.

[Cellulose ester dope composition A]
Cellulose triacetate having a degree of acetyl substitution of 2.88 (number average molecular weight 150,000) 100 parts by weight vinyl acetate 5 parts by weight vinyl laurate 5 parts by weight benzoin 1 part by weight AEROSIL R972V 0.1 part by weight methylene chloride 475 parts by weight ethanol 25 parts by weight [ Cellulose ester dope composition B]
Cellulose triacetate with a degree of acetyl substitution of 2.88 (number average molecular weight 150,000) 100 parts by weight methyl acrylate 5 parts by weight vinyl butyrate 2 parts by weight ASM-2 3 parts by weight benzoin 1 part by weight AEROSIL R972V 0.1 part by weight methylene chloride 475 parts by weight Ethanol 25 parts by mass [cellulose ester dope composition C]
Cellulose triacetate with a degree of acetyl substitution of 2.88 (number average molecular weight 150,000) 100 parts by weight vinyl acetate 4 parts by weight vinyl stearate 3 parts by weight dipentaerythritol hexaacrylate 3 parts by weight diethoxybenzophenone 1 part by weight AEROSIL R972V 0.1 part by weight Methylene chloride 475 parts by mass Ethanol 25 parts by mass [cellulose ester dope composition D]
Cellulose triacetate with a degree of acetyl substitution of 2.88 (number average molecular weight 150,000) 100 parts by weight Vinyl acetate 4 parts by weight Vinyl stearate 3 parts by weight UVM-1 3 parts by weight M-1310 (urethane acrylate, manufactured by Toagosei Co., Ltd.) 1 part by weight Methyl acrylate 0.5 parts by weight Diethoxybenzophenone 1 part by weight AEROSIL R972V 0.1 part by weight Methylene chloride 475 parts by weight Ethanol 25 parts by weight

(Film Formation) The cellulose ester dope compositions A to D were prepared as follows. Each was put into a pressure sealed container, heated to 45 ° C., the pressure in the container was 1.2 atm, and the cellulose ester was completely dissolved while stirring to obtain a dope composition (hereinafter referred to as “dope”). The dope temperature was lowered to 35 ° C. and allowed to stand overnight, and this dope was added to Azumi filter paper No. 1 manufactured by Azumi Filter Paper Co., Ltd. After filtration using 244, the mixture was further allowed to stand overnight for defoaming. Next, a filtration pressure of 1.0 using Finemet NM (absolute filtration accuracy 100 μm) and Finepore NF (absolute filtration accuracy 50 μm, 15 μm, 5 μm in order of absolute filtration accuracy) manufactured by Nippon Seisen Co., Ltd. It filtered by * 10 < ⁶ > Pa and used for film forming. Using a dope at 35 ° C. obtained by filtration, the film was cast from a hanger type die onto an endless stainless belt having an infinite transition at 22 ° C. to form a film. While applying a wind of 40 ° C. to the web on a stainless steel belt, eight 2 kW high-pressure mercury lamps were irradiated from a distance of 15 cm to cause photopolymerization to produce a polymer in the web. This high-pressure mercury lamp has a reflector and a cooling device. The total irradiation amount at an arbitrary position of the web on the stainless steel belt was set to 300 mj / cm ² . For all webs, the web was peeled off with a residual solvent amount of 25% by mass, passed through three rolls, and then gripped at both ends of the web with pin clips as described in JP-A-62-115035. The web is introduced into a tenter dryer and dried at 90 to 115 ° C., then dried at 110 to 130 ° C. with a roll dryer, and the dried web is wound up with a residual solvent amount of 0.2% by mass to form a film. Cellulose ester films 1 to 4 having a thickness of 80 μm were obtained. Similarly, a cellulose ester film 5 having a thickness of 60 μm, a cellulose ester film 6 having a thickness of 40 μm, and a cellulose ester film 7 having a thickness of 30 μm were prepared from the cellulose ester dope composition of A above.

Preparation of Cellulose Ester Film 8 The cellulose ester dope composition of A above is used as a base layer dope, and a dope composition of the following formulation is co-cast as a surface layer dope, and each thickness after drying is 0.06 mm (base layer) ) And 0.01 (surface layer) mm. The cellulose ester film 8 was produced by drying with hot air at 100 ° C. until the residual solvent amount reached 10% by mass and then drying with hot air at 140 ° C. for 10 minutes.
[Surface dope composition]
Cellulose triacetate having a degree of acetyl substitution of 2.88 (number average molecular weight 150000) 17.0 parts by mass Methylene chloride 90.0 parts by mass Ethanol 10.0 parts by mass Triphenyl phosphate 0.51 parts by mass
0.085 parts by mass of SiO ₂

Production of Cellulose Ester Film 9 The base layer dope and the surface layer dope were successively cast using the same base layer and surface layer dope as the cellulose ester film 8, and the respective thicknesses after drying were 0.06 mm (base layer) and 0.01 mm ( Surface layer). The cellulose ester film 9 was produced by drying with hot air at 100 ° C. until the residual solvent amount reached 10% by mass, and then drying with hot air at 140 ° C. for 10 minutes.

(Preparation of coating liquid A for hard coat layer)
25.4 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was diluted with 46.3 g of methyl isobutyl ketone. Furthermore, 1.3 g of a polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was added and mixed and stirred. Subsequently, 0.04 g of fluorine leveling agent (P-1), 5.2 g of silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), cellulose acetate butyrate (CAB-531) having a molecular weight of 40,000. −1, Eastman Chemical Co., Ltd.) 0.50 g was added and stirred for 120 minutes with an air disper to completely dissolve the solute. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.520.
Finally, 30 of crosslinked poly (acryl-styrene) particles having an average particle diameter of 3.5 μm (copolymerization composition ratio = 50/50, refractive index 1.536) dispersed in this solution for 20 minutes at 10,000 rpm with a Polytron disperser. After adding 21.0 g of% methyl isobutyl ketone dispersion, the mixture was stirred with an air disper for 10 minutes.
The mixed solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution A for hard coat layer.

Preparation of coating liquid B for hard coat layer A mixture of 100 parts by mass of Desolite Z7404 (hard coat composition liquid containing zirconia fine particles: manufactured by JSR Corporation), dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku) 31 parts by mass), fluorine leveling agent (P-1) 0.08 g, KBM-5103 (silane coupling agent: manufactured by Shin-Etsu Chemical Co., Ltd.) 10 parts by mass, KE-P150 (1) 8.9 parts by mass of 0.5 μm silica particles (manufactured by Nippon Shokubai Co., Ltd.), 3.4 parts by mass of MXS-300 (3 μm crosslinked PMMA particles: manufactured by Soken Chemical Co., Ltd.), 29 parts by mass of MEK, and 13 parts by mass of MIBK The mixture was put into a mixing tank and stirred, and then filtered through a polypropylene filter having a pore size of 30 μm to prepare coating liquid B for hard coat layer. It was.

Preparation of coating solution C for hard coat layer 90 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.), polymerization initiator (Irgacure 184, Ciba Specialty Chemicals) 3.0 g, fluorine leveling agent (P-1) 0.08 g, KBM-5103 (silane coupling agent: Shin-Etsu Chemical Co., Ltd.) 10 parts by mass, MEK 35 parts by mass Then, 55 parts by mass of MIBK was put into a mixing tank and stirred, and then filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a coating liquid C for hard coat layer.

  (Low refractive index layer)

(Synthesis of perfluoroolefin copolymer (1))

Into a stainless steel autoclave with a stirrer of 100 ml, 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether and 0.55 g of dilauroyl peroxide were charged, and the inside of the system was deaerated and replaced with nitrogen gas. Further, 25 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 0.53 Mpa (5.4 kg / cm ² ). The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 0.31 MPa (3.2 kg / cm ² ), the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. After drying, 28 g of polymer was obtained. Next, 20 g of the polymer was dissolved in 100 ml of N, N-dimethylacetamide, and 11.4 g of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 19 g of perfluoroolefin copolymer (1). The resulting polymer had a refractive index of 1.421.

(Preparation of sol solution)
A stirrer, a reactor equipped with a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts of diisopropoxyaluminum ethyl acetoacetate were added and mixed. Thereafter, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain sol solution a. The mass average molecular weight was 1600, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100%. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

(Adjustment of coating solution A for low refractive index layer)
Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.44 containing polysiloxane and hydroxyl group (JTA113, solid content concentration 6%, manufactured by JSR Corporation) 13 g, colloidal silica dispersion MEK-ST-L (trade name, average) Particle size 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Co., Ltd.) 1.3 g, sol solution 0.6 g, methyl ethyl ketone 5 g, cyclohexanone 0.6 g were added, and after stirring, a polypropylene filter having a pore size of 1 μm Filtration was performed to prepare a low refractive index layer coating solution A. The refractive index of the layer formed with this coating solution was 1.45.

(Adjustment of coating liquid B for low refractive index layer)
(Preparation of dispersion A)
Hollow silica fine particle sol (Isopropyl alcohol silica sol, average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20% by mass, silica particle refractive index 1.31, prepared by changing the size according to Preparation Example 4 of JP-A-2002-79616 ) After adding 30 g of acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 1.5 g of diisopropoxyaluminum ethyl acetate to 500 g, 9 g of ion-exchanged water was added. After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature, and 1.8 g of acetylacetone was added. While adding cyclohexanone to 500 g of this dispersion so that the silica content was almost constant, solvent substitution was performed by distillation under reduced pressure at a pressure of 20 kPa. There was no generation of foreign matter in the dispersion, and the viscosity when the solid content concentration was adjusted to 20% by mass with cyclohexanone was 5 mPa · s at 25 ° C. When the residual amount of isopropyl alcohol in the obtained dispersion Ag was analyzed by gas chromatography, it was 1.5%.

(Preparation of coating solution B)
Dispersion A-1 with respect to 783.3 parts by mass (47.0 parts by mass as a solid content) of OPSTAR JTA113 (thermally crosslinkable fluorine-containing silicone polymer composition liquid (solid content 6%): manufactured by JSR Corporation) 195 parts by mass (silica + 39.0 parts by mass as surface treatment agent solids), colloidal silica dispersion (silica, MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30%, Nissan Chemical ( 30.0 parts by mass (9.0 parts by mass as solids) and 17.2 parts by mass of sol liquid a (5.0 parts by mass as solids) were added. A coating solution B for low refractive index was prepared by diluting with cyclohexane and methyl ethyl ketone so that the solid content concentration of the entire coating solution was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 10:90. The refractive index of the layer formed with this coating solution was 1.39.

(Preparation of coating solution C for low refractive index layer)
Perfluoroolefin copolymer (1) 15.2 g, hollow silica sol (refractive index 1.31, average particle size 60 nm, solid content 20%) 2.1 g, reactive silicone X-22-164B (trade name; Shin-Etsu) Chemical Industry Co., Ltd.) 0.3 g, sol solution a 7.3 g, photopolymerization initiator (Irgacure 907 (trade name), Ciba Specialty Chemicals Co., Ltd.) 0.76 g, methyl ethyl ketone 301 g, cyclohexanone 9.0 g After the addition and stirring, the mixture was filtered through a polypropylene filter having a pore size of 5 μm to prepare a coating solution C for a low refractive index layer. The refractive index of the layer formed by this coating solution was 1.40.

[Example 1]
(1) Coating of hard coat layer The cellulose ester film 1 was coated with the coating liquid A for hard coat layer by the die coating method shown in the apparatus configuration described in JP2003-211052 and the following coating conditions, and at 30 ° C. After drying for 20 seconds at 90 ° C. for 15 seconds, and further applying with UV irradiation with an irradiation amount of 90 mJ / cm ² using a 160 W / cm air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) under a nitrogen purge. The layer was cured to form a 6 μm thick anti-glare hard coat layer and wound up.

Basic conditions: The slot die 13 has an upstream lip land length I _UP of 0.5 mm, a downstream lip land length I _LO of 50 μm, a length of the opening of the slot 16 in the web running direction of 150 μm, and the length of the slot 16 The one with a length of 50 mm was used. The gap between the upstream lip land 18a and the web W is 50 μm longer than the gap between the downstream lip land 18b and the web W (hereinafter referred to as an overbite length of 50 μm), and the gap between the downstream lip land 18b and the web W _GL was set to 50 μm. Further, the gap G _B between the gap G _S, and the back plate 40a and the web W between the side plate 40b and the web W in the vacuum chamber 40 were both 200 [mu] m. In accordance with the liquid physical properties of each coating solution, in the case of anti-glare layer: anti-glare layer coating solutions A and C: coating speed = 20 m / min, wet coating amount = 17.5 ml / m ² , for anti-glare layer In the case of coating solution B: coating speed = 40 m / min, wet coating amount = 17.5 ml / m ² , low refractive index layer: coating speed = 40 m / min, wet coating amount = 5.0 ml / m ² went. The application width was 1300 mm and the effective width was 1280 mm.

(2) Coating of low refractive index layer The triacetyl cellulose film coated with the antiglare layer coating liquid A and coated with a hard coat layer is unwound again, and the low refractive index layer coating liquid A is used as described above. After being dried at 120 ° C. for 150 seconds and further dried at 140 ° C. for 8 minutes, a 240 W / cm air-cooled metal halide lamp (eye graphics) under an atmosphere with an oxygen concentration of 0.1% by nitrogen purge. Ltd.) was used to an irradiation dose of 300 mJ / cm ^2, to form a low refractive index layer having a thickness of 100 nm, was wound.
Thus, the antireflection film of Example 1 was produced. Similarly, an antireflection film was produced under the conditions shown in Table 1.
Example 21
An antireflection film was produced under the same conditions as in Example 1, except that the coating method was changed to a microgravure coating method. The produced antireflection film exhibited good performance similar to that of the antireflection film of Example 1. The details of the microgravure coating method were performed in accordance with JP-A-2-119777.

The following evaluation was implemented with respect to the produced antireflection film.
Pencil hardness evaluation Pencil hardness evaluation described in JIS K5400 was performed as an index of scratch resistance. After conditioning the antireflection film at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, using a 3H test pencil specified in JIS S6006, scratches were recognized at the evaluation of n = 5 with a load of 1 kg. No ： ○
In evaluation of n = 5, 1 or 2 scratches:
In evaluation of n = 5, 3 or more scratches: ×
Furthermore, even if a 4H test pencil showed no scratches in the evaluation of n = 5, it was evaluated as “◎”.

Curl Evaluation The curl of the hard coat film was measured using the curl measurement template of Method A in “Measurement Method of Curling of Photographic Film” of JIS K7619-1988. The measurement conditions are 25 ° C., relative humidity 60%, and humidity control time 10 hours. Here, “curl plus” means a curl where the hard coat layer coating side of the film is inside the curve, and “minus” means a curl where the coating side is outside the curve. Further, the curl is expressed by the following formula B.
(Formula B) Curl = 1 / R R is the radius of curvature (m)
According to the curl amount after adjusting the humidity for the predetermined time, the ranking is as follows.
Minus 5 to Plus 5: ◎
Minus 10 to minus 5, plus 5 to plus 10: ○
Minus 15 to minus 10, plus 10 to plus 15: △
Minus 15 or less, plus 15 or more: ×

  As is apparent from Table 1, it can be seen that the antireflection film of the present invention exhibits good surface hardness. Further, since the surface hardness can be secured even when the film thickness of the cellulose ester film is reduced, the antireflection film can be made thinner. Furthermore, since the surface hardness can be ensured even if the thickness of the hard coat layer is reduced, the cost of the hard coat layer can be reduced and the curl can be improved.

  The antireflective films obtained in Examples 1 to 20 were immersed in a 2.0 normal, 55 ° C. NaOH aqueous solution for 2 minutes to saponify the triacetyl cellulose surface on the back side of the film. Polarized by adhering and protecting both sides of a polarizer prepared by adsorbing iodine to polyvinyl alcohol with a film obtained by saponifying an acetylcellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) under the same conditions and stretching. A board was created. The thus-prepared polarizing plate is a liquid crystal display device of a notebook computer equipped with a transmission type TN liquid crystal display device (Sumitomo 3M Co., Ltd., which is a polarization separation film having a polarization selection layer) so that the antireflection film side is the outermost surface. When D-BEF made of D-BEF is replaced with a polarizing plate on the viewing side), display quality with very little background reflection and uniformity in the display surface is ensured. A very high display device was obtained.

It is a schematic sectional drawing which shows typically preferable embodiment of the antireflection film of this invention. It is a schematic sectional drawing which shows typically preferable embodiment of the antireflection film of this invention. It is a schematic sectional drawing which shows typically preferable embodiment of the antireflection film of this invention. It is a schematic sectional drawing which shows typically preferable embodiment of the antireflection film of this invention. It is a schematic sectional drawing which shows typically preferable embodiment of the antireflection film of this invention. It is a schematic sectional drawing which shows typically preferable embodiment of the cellulose-ester film used by this invention. It is a schematic sectional drawing which shows typically preferable embodiment of the cellulose-ester film used by this invention. The solution casting apparatus using the casting band of the cellulose ester film used by this invention is shown. The solution casting apparatus using the casting drum of the cellulose ester film used by this invention is shown. An example of the casting die of a solution casting apparatus is shown. An example of the casting die of a solution casting apparatus is shown. An example of the casting die of a solution casting apparatus is shown.

Explanation of symbols

(1) Transparent support (2) Hard coat layer (3) Medium refractive index layer (4) High refractive index layer (5) Low refractive index layer 1 Base layer 2 Surface layer 11 Stirrer 12 Transfer pump 13 Filter 14 Stock tank 15 Flow Casting liquid pump 16 Additive injection pump 17 Casting die 18 Casting band 19 Depressurization chamber 20 Casting drum 30 Dies 31, 32, 33 Manifold 34 Feed block

Claims (30)

  On a cellulose ester film formed by solution casting a cellulose ester dope composition containing an ethylenically unsaturated monomer and / or a functional group-containing ethylenically unsaturated monomer and a photopolymerization initiator, at least An antireflection film comprising a hard coat layer.   The cellulose ester film is a semi-IPN (semi-interpenetrating network structure) type polymer alloy comprising a cellulose ester and a crosslinked polymer obtained by polymerizing the ethylenically unsaturated monomer and / or the ethylenically unsaturated monomer having a functional group. The antireflection film according to claim 1, which has a structure.   The antireflective film according to claim 1, wherein the ethylenically unsaturated monomer is mainly a vinyl ester.   The antireflection film according to any one of claims 1 to 3, wherein the cellulose ester dope composition contains an ethylenically unsaturated monomer having 2 to 3 ethylenically unsaturated groups. .   The antireflection film according to any one of claims 1 to 4, wherein the functional group is an ultraviolet absorbing group and / or an antistatic group.   On a cellulose ester film formed by solution casting a cellulose ester dope composition containing a compound having an epoxy group and / or a compound having an epoxy group and an ultraviolet absorbing group and a photopolymerization initiator, An antireflection film, comprising at least a hard coat layer.   Semi-IPN (semi-interpenetrating network) type polymer in which the cellulose ester film is a cellulose ester and a crosslinked polymer obtained by polymerizing a compound having an epoxy group and / or a compound having an epoxy group and an ultraviolet absorbing group The antireflection film according to claim 6, which has an alloy structure.   The antireflection film according to any one of claims 1 to 7, wherein the cellulose ester dope composition contains fine particles.   9. The antireflection film according to claim 8, wherein the fine particles are composed of a compound containing silicon oxide having a methyl group on the surface.   Cellulose ester dope containing a polymer obtained by polymerizing an ethylenically unsaturated monomer mainly composed of a monomer selected from vinyl ester and acrylic acid ester having a functional group and / or an ethylenically unsaturated monomer selected from vinyl ester and acrylic acid ester An antireflection film comprising a cellulose ester film formed by solution casting of a composition and at least a hard coat layer.   The cellulose ester film is an ethylenically unsaturated monomer mainly composed of a cellulose ester and an ethylenically unsaturated monomer selected from the above vinyl esters and acrylic esters and / or a vinyl ester having a functional group and an acrylic ester. The antireflection film according to claim 10, which has a semi-IPN (semi-interpenetrating network structure) type polymer alloy structure with a crosslinked polymer obtained by polymerizing monomers.   The antireflection film according to claim 10 or 11, wherein the functional group is an ultraviolet absorbing group and / or an antistatic group.   The antireflection film according to any one of claims 10 to 12, wherein the cellulose ester dope composition contains fine particles.   14. The antireflection film according to claim 13, wherein the fine particles are made of a compound containing silicon oxide having a methyl group on the surface.   The film thickness of the said hard-coat layer is 2 micrometers or more and 6 micrometers or less, The antireflection film as described in any one of Claims 1-14 characterized by the above-mentioned.   The film thickness of the said cellulose-ester film is 40 micrometers or more and less than 80 micrometers, The antireflection film as described in any one of Claims 1-15 characterized by the above-mentioned.   The antireflection film according to any one of claims 1 to 16, wherein the hard coat layer has an antiglare property.   The antireflection film according to any one of claims 1 to 17, wherein a low refractive index layer having a lower refractive index than that of the hard coat layer is coated on the hard coat layer.   The cellulose ester film is a cellulose ester film having a multilayer structure having at least a base layer and a surface layer, and a matting agent is added only to the surface layer. Antireflection film.   The antireflection film according to claim 19, wherein the surface layer has a center line average roughness of 0.01 μm to 5 μm.   The antireflection film according to claim 19 or 20, wherein the surface layer has a center line average roughness of 0.1 µm to 1 µm.   The cellulose ester film produced by using inorganic particles as a matting agent and casting a composition containing inorganic particles by a co-casting method to form a surface layer is used. Item 22. The antireflection film according to any one of Items 21.   The cellulose ester film manufactured by using inorganic particles as a matting agent and casting a composition containing inorganic particles by a sequential casting method to form a surface layer is used. The antireflection film according to claim 21.   The cellulose ester dope composition according to any one of claims 1 to 9 is cast on an endless metal support that moves infinitely in a solution casting film forming apparatus, and then the drying of the web is completed by a drying apparatus. An antireflective film characterized by using a cellulose ester film produced by irradiating a web with ultraviolet rays.   The cellulose ester film produced by irradiating with ultraviolet rays between casting and peeling to an endless metal support that moves infinitely the cellulose ester dope composition is used according to claim 24. The antireflection film described   An antireflection film comprising a cellulose ester film produced by solution casting the cellulose ester dope composition according to any one of claims 10 to 14.   A polarizing plate comprising the antireflection film according to claim 1.   27. The antireflection film according to claim 1 to 26 is used as one protective film of the polarizing film, and the thickness direction retardation Rth of the protective film is 40 nm to −50 nm as the other protective film of the polarizing film. A polarizing plate characterized by that.   The antireflection film according to claim 1 to 26 is used as one protective film of the polarizing film, and an optical compensation film having optical anisotropy is used as the other protective film of the polarizing film. Polarizing plate.   An image display device comprising the antireflection film according to claim 1 or the polarizing plate according to claim 27 to 29.

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