JPH1138201A - Antireflection film and image display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the film strength and durability of a low-refractive index layer and to obtain high anti-reflection efficiency by strictly regulating the film thicknesses and refractive indices of respectively layers. SOLUTION: A middle-refractive index layer, high-refractive index layer and low-refractive index layer are successively formed from a base material side toward an air surface on the front surface of a transparent base material. The middle-refractive index layer contains the metal oxide selected from aluminum, etc., and the high-refractive index layer contains titanium oxide. The low-refractive index layer contains particulates consisting of a polymer of a fluorine-contained monomer and microvoids which do not scatter light. The refractive indices and film thicknesses of the respective layers are in ranges of the middle-refractive index layer: n3=1.60×1.70, hλ/4×0.8<n3d3<hλ/4λ1.2, the high-refractive index layer: n2=1.90 to 2.20, hλ/4×0.8<n2d2<hλ/4×1.2, the low-refractive index layer: n1=1.37 to 1.46, hλ/4×0.8<n1d1<hλ/4×1.2, where (h) and (k) respectively denote 1, 2 or 3 and (n) and (d) respectively denote the refractive indices and layer thicknesses (nm) of the respectively refractive index layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display (L).
CD), a cathode ray tube display (CRT), a plasma display (PDP), an electroluminescent display (ELD), and an image having an antireflection film effective for lowering the reflectance of an image display surface of an image display device. It relates to a display device.

[0002]

2. Description of the Related Art Conventionally, visible light (about 400 to 700 nm)
As an antireflection film for light having a wide wavelength range as described above, a multilayer film in which a transparent thin film of a metal compound such as a metal oxide is laminated has been used. When a single-layer film having a low refractive index is used instead of a multilayer film as an antireflection film, it is effective for monochromatic light, but a single-layer film is effective for light having a wide wavelength range to some extent. Does not show a protective effect. In the above-described multilayer film, the more the number of layers, the more effective the antireflection film for light having a wider wavelength range. Therefore, as the conventional antireflection film, a film obtained by laminating three or more layers of metal oxide or the like by means such as physical or chemical vapor deposition has been used. However, in order to form an antireflection film having a multilayer structure by vapor deposition, physical vapor deposition whose thickness is controlled with high precision in accordance with the relationship between the refractive index and the film thickness of each layer that has been optimally designed in advance is performed on the layer. It needs to be performed in a number of times, and is complicated and very expensive. Further, in order to improve the anti-contamination property such as scratch resistance or fingerprint adhesion of the surface, it is necessary to newly provide a layer made of a fluorine-containing resin, for example.

In addition to the above-described method using a multilayer film, a method for obtaining an antireflection effect by a film whose refractive index gradually changes in the film thickness direction from the interface with air is known. For example, JP-A-2-245702 discloses that an ultrafine particle of SiO ₂ having an intermediate refractive index between a glass substrate and MgF ₂ and an ultra fine particle of MgF ₂ are mixed and applied to a glass substrate, and then applied from the glass substrate surface. SiO gradually toward the film surface
By decreasing the mixing ratio of ₂ to increase the mixing ratio of MgF _2, with greatly changes in the refractive index of the coating layer, the coating layer and the air, and the refractive index change at the interface between the coating layer and the glass substrate It is described that an anti-reflection effect can be obtained by making it gentle. The thus formed anti-reflection film exhibits a high anti-reflection effect because the change in the refractive index between the bottom surface and the glass surface is small.

[0004] Also, Japanese Patent Application Laid-Open No. 5-13021 discloses that
An antireflection film comprising two layers using ultrafine particles having MgF ₂ and SiO ₂ dispersed in ethyl silicate is disclosed. For example, the first layer is composed of 7 MgF ₂ / SiO _2.
The second layer is a layer in which MgF ₂ / SiO ₂ is 1/1, the refractive index of the first layer is 1.42, and the refractive index of the second layer is 1.44. Therefore, the change in the refractive index cannot be said to be large, and a sufficient antireflection effect cannot be obtained.

[0005] Japanese Patent Application Laid-Open No. 7-92305 discloses that
Refractive index of 1.428 consisting of core and surrounding shell
An anti-reflection film is disclosed which comprises an upper layer portion (low refractive index) having irregularities on the surface formed of air and fine particles and a lower layer portion formed only of fine particles.
And the core of the ultrafine particles is methyl methacrylate, methacrylic acid, trifluoroethyl acrylate,
Formed from N-isobutoxymethylacrylamide,
The shell part is formed from styrene, acrylic acid, and butyl acrylate.

Further, Japanese Patent Application Laid-Open No. Hei 7-168006 discloses that the surface formed of air and fine particles (eg, MgF ₂ ) has an irregular upper layer portion (low refractive index) and a fine particle only middle layer portion (medium refractive index). ), And an antireflection film comprising fine particles and a lower layer portion formed of a binder.

[0007] However, the above-mentioned Japanese Patent Application Laid-Open No. Hei 2-2457.
02, JP-A-5-13021, JP-A-7-
The antireflection films described in JP-A-92305 and JP-A-7-168006 utilize the principle that the refractive index to air gradually changes in the thickness direction. These antireflection films require complicated operations and skillful techniques for their preparation, and the obtained films do not have a satisfactory antireflection effect.

The inventors include fine particles comprising a polymer of a fluorine-containing monomer having an average particle size of 200 nm or less,
By stacking at least two fine particles, it is possible to form a low-refractive-index layer by a film containing microvoids on average between the fine particles, and by forming an antireflection film including the low-refractive layer. It has been found that a low refractive index film can be formed.

However, simply laminating the fine particles does not provide sufficient adhesion between the particles, resulting in insufficient film strength. Further, the adhesion between the layer and the lower layer is not sufficient, resulting in peeling. There was a problem that happened.

[0010]

SUMMARY OF THE INVENTION The present invention relates to an antireflection film comprising a low refractive index layer containing microvoids, which improves the film strength and durability of the low refractive index layer, and improves the film thickness and the thickness of each layer. An object of the present invention is to provide an antireflection film that exhibits a high antireflection effect by strictly defining a refractive index. The present invention also provides an antireflection film comprising a low-refractive-index layer containing microvoids that do not scatter light (hereinafter, simply referred to as microvoids). An object of the present invention is to provide an image display device provided with an anti-reflection film exhibiting a high anti-reflection effect by strictly defining the film thickness and the refractive index.

[0011]

The above-mentioned problems are solved by the following antireflection film. (1) An antireflection film in which a middle refractive index layer, a high refractive index layer, and a low refractive index layer are formed on at least one of the surfaces of the transparent substrate in order from the substrate side to the air surface, and each layer is The polymer contains at least one kind of monomer having two or more polymerizable groups, and the polymer is polymerized after forming each layer, and the medium refractive index layer is made of aluminum, titanium, zirconium, antimony. Contains at least one metal oxide selected from zinc and tin, the high refractive index layer contains titanium oxide, and the low refractive index layer contains fine particles made of a polymer of a fluorine-containing monomer and microvoids that do not scatter light, An antireflection film, wherein the refractive index and the film thickness of each layer are in the following ranges. Medium refractive index layer n3 = 1.60-1.70 hλ / 4 × 0.8 <n3 d3 <hλ / 4 × 1.2 High refractive index layer n2 = 1.90-2.20 kλ / 4 × 0.8 <n2d2 <kλ / 4 × 1.2 Low refractive index layer n1 = 1.37-1.46 λ / 4 × 0.8 <n1d1 <λ / 4 × 1.2 (In the above formula, h represents 1, 2 or 3, and n3 is medium refraction. Represents the refractive index of the refractive index layer, and d3 is the thickness of the medium refractive index layer (n
m), k represents 1, 2 or 3, n2 represents the refractive index of the high refractive index layer, d2 represents the layer thickness (nm) of the high refractive index layer, and n1 represents the refractive index of the low refractive index layer. Represents the rate, and d
1 represents the thickness (nm) of the low refractive index layer. )

(2) An antireflection film having a medium refractive index layer, a high refractive index layer, and a low refractive index layer formed on at least one of the surfaces of the transparent substrate in order from the substrate side to the air surface, Each layer contains a polymer made of a monomer having at least one kind of two or more polymerizable groups, and the medium refractive index layer is made of at least one metal selected from aluminum, titanium, zirconium, antimony, zinc, and tin. The oxide has a high refractive index layer containing titanium oxide, the low refractive index layer contains fine particles made of a polymer of a fluorine-containing monomer and microvoids that do not scatter light, and the refractive index and film thickness of each layer are in the following ranges ( A) An anti-reflection film, characterized in that: (A) Medium refractive index layer n3 = 1.60-1.70, d3 = 60-110 nm (A) High refractive index layer n2 = 1.90-2.20, d2 = 90-190 nm (A) Low refractive index layer n1 = 1.37-1.46, d1 = 70-130 nm (wherein n3 represents the refractive index of the middle refractive index layer,
d3 represents the thickness (nm) of the middle refractive index layer, n2 represents the refractive index of the high refractive index layer, and d2 represents the thickness of the high refractive index layer (n
m), n1 represents the refractive index of the low refractive index layer, and d1 represents the layer thickness (nm) of the low refractive index layer. )

(3) An antireflection film having a medium refractive index layer, a high refractive index layer, and a low refractive index layer formed on at least one of the surfaces of the transparent substrate in order from the substrate side to the air surface, Each layer contains a polymer made of a monomer having at least one kind of two or more polymerizable groups, and the medium refractive index layer is made of at least one metal selected from aluminum, titanium, zirconium, antimony, zinc, and tin. The oxide has a high refractive index layer containing titanium oxide, the low refractive index layer contains fine particles made of a polymer of a fluorine-containing monomer and microvoids that do not scatter light, and the refractive index and film thickness of each layer are in the following ranges ( B) An antireflection film, characterized in that: (B) Medium refractive index layer n3 = 1.60-1.70, d3 = 180-330 nm (B) High refractive index layer n2 = 1.90-2.20, d2 = 90-190 nm (B) Low refractive index layer n1 = 1.37-1.46, d1 = 70-130 nm (wherein n3 represents the refractive index of the middle refractive index layer,
d3 represents the thickness (nm) of the middle refractive index layer, n2 represents the refractive index of the high refractive index layer, and d2 represents the thickness of the high refractive index layer (n
m), n1 represents the refractive index of the low refractive index layer, and d1 represents the layer thickness (nm) of the low refractive index layer. )

(4) An antireflection film having a medium refractive index layer, a high refractive index layer, and a low refractive index layer formed on at least one of the surfaces of the transparent substrate in order from the substrate side to the air surface, Each layer contains a polymer made of a monomer having at least one kind of two or more polymerizable groups, and the medium refractive index layer is made of at least one metal selected from aluminum, titanium, zirconium, antimony, zinc, and tin. The oxide has a high refractive index layer containing titanium oxide, the low refractive index layer contains fine particles made of a polymer of a fluorine-containing monomer and microvoids that do not scatter light, and the refractive index and film thickness of each layer are in the following ranges ( C) An antireflection film, characterized in that: (C) Medium refractive index layer n1 = 1.60-1.70, d1 = 60-110 nm (C) High refractive index layer n2 = 1.90-2.20, d2 = 45-90 nm (C) Low refractive index layer n3 = 1.37-1.46, d3 = 70-130 nm (wherein n3 represents the refractive index of the middle refractive index layer,
d3 represents the thickness (nm) of the middle refractive index layer, n2 represents the refractive index of the high refractive index layer, and d2 represents the thickness of the high refractive index layer (n
m), n1 represents the refractive index of the low refractive index layer, and d1 represents the layer thickness (nm) of the low refractive index layer. )

(5) The micro-void volume fraction of the low refractive index layer is in the range of 0.05 to 0.50.
Or the antireflection film according to (2) or (3) or (4). (6) The antireflection film according to the above (1), (2), (3) or (4), wherein the fine particles comprising the polymer of the fluorine-containing monomer have a core-shell structure. (7) The above (1) or (2) or (3) or (4) wherein the haze value of the antireflection film is in the range of 3 to 40%.
2. The antireflection film according to 1. (8) An image display device comprising the antireflection film according to (1) or (2) or (3) or (4).

The antireflection film of the present invention comprises, from the air side to the substrate side, a low refractive index layer composed of the above-mentioned fluoropolymer fine particles and microvoids, a high refractive index layer having a higher refractive index, and a high refractive index layer. And a medium refractive index layer having a lower refractive index than the refractive index layer and a higher refractive index than the substrate. The relationship between the refractive index and the film thickness of the layer defined in the above (1) is disclosed in
It can be guided optically as described in JP 9-50401.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows another typical example of the antireflection film of the present invention. The middle refractive index layer 8 is a transparent film (support)
12, the high refractive index layer 5 is formed on the middle refractive index layer 8, and the low refractive index layer 1 is formed on the high refractive index layer 5. In the low refractive index layer of the present invention, microvoids 3 are formed between the fine particles by laminating fine particles made of a polymer of at least two fluorine-containing monomers in the thickness direction. Since the size of the particles is almost the same, the microvoids are usually formed uniformly in the size of the voids and at the intervals. The low-refractive-index layer of the present invention is fine particles in a micro structure, but can be regarded as one layer in a macro structure. Fine particles made of a polymer of a fluorine-containing monomer are generally melted or softened by solvent removal or heating and adhere to each other. Alternatively, when the fine particles made of the polymer of the fluorine-containing monomer have a functional group (reactive group), the particles can be bonded to each other by a reaction between the functional groups. Further, the fine particles made of a polymer of the fluorine-containing monomer need to be firmly adhered to a very small amount of at least one kind of polymer 4 made of a monomer having two or more polymerizable groups. The high refractive layer contains titanium oxide fine particles 6 and the middle refractive layer contains metal oxide fine particles (preferably titanium oxide or tin oxide) 9 of aluminum, titanium, zirconium, antimony, zinc or tin. Both layers contain polymers 7, 10 each consisting of at least one monomer having two or more polymerizable groups. Polymers 4, 7, 10 are 2
Since it is formed from a monomer having two or more polymerizable groups, it is insoluble in solvents. Therefore, after forming each layer,
The monomers are polymerized to form a polymer.

The refractive index of air on the surface of the low refractive index layer of the present invention is 1, and the refractive index of the fine particles comprising a polymer of the fluorine-containing monomer of the present invention is higher than the refractive index of air, generally 1. Between 25 and 1.46. The low refractive index layer of the present invention is located between the refractive index of the air layer and the refractive index of the fine particles themselves. Therefore, the refractive index of the low refractive index layer of the present invention can be made lower than the refractive index of the material by the volume fraction of microvoids by making the fine particles made of the polymer of the fluorine-containing monomer smaller. The average particle size of the fine particles made of the polymer of the fluorine-containing monomer is generally in the range of 5 to 200 nm, preferably 5 to 50 nm. The thickness of the low refractive index layer is generally 5 to 400 nm.
And the thickness is preferably 50 to 200 nm.

The average particle diameter of the fine particles made of the fluoromonomer polymer used in the present invention is 5 to 200 n.
m is generally in the range of 5 to 100 nm, preferably 5 to 100 nm.
50 nm is particularly preferred. Such fine particles are obtained, for example, from a polymer latex. When the particle size of the fine particles increases, scattering on the film surface increases. When the particle size exceeds 200 nm, the scattered light becomes undesirably colored. As the polymer of the fluorine-containing monomer used in the antireflection film of the present invention, any of a crystalline polymer and an amorphous polymer can be used. Until now, a polymer of a fluorine-containing monomer having crystallinity could not be used as a film of an optical material in order to reduce light transmittance, but use fine particles having a particle size sufficiently smaller than the wavelength of light Thus, even a film having crystallinity can be used as an anti-reflection film without reducing light transmittance. The glass transition temperature (Tg) of the fine particles made of the polymer of the fluorine-containing monomer in the present invention is preferably 70 ° C. or more, and particularly preferably 100 ° C. The upper limit varies depending on the base material used, but is 2
00 ° C or lower is preferred. When the Tg is lower than room temperature, the fine particles are excessively softened and thus are easily broken, so that microvoids disappear and the refractive index increases. As the fine particles made of a polymer of a fluorine-containing monomer, fine particles made of a polymer of two or more kinds of fluorine-containing monomers having different Tg can be used. In that case, the difference in Tg is generally at least 5 ° C., and preferably at least 20 ° C.

The monomer unit of the fluoropolymer forming the fine particles of the present invention is not particularly limited as long as the monomer contains a fluorine atom. Specific examples of these monomers include, for example, fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3
-Dioxole, etc.), acrylic or methacrylic acid moieties and fully fluorinated alkyl, alkenyl, aryl esters (e.g., compounds represented by the following general formula), fully or partially fluorinated vinyl ethers, fully or partially fluorinated vinyl esters And fully or partially fluorinated vinyl ketones, and the desired polymer can be obtained by copolymerization by combining any of these monomers at any ratio.

[0021]

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In the formula, R ₁ is a hydrogen atom, having 1 to 3 carbon atoms.
Represents an alkyl group or a halogen atom. Rf represents a completely or partially fluorinated alkyl group, alkenyl group, heterocycle or aryl group. R ₂ and R ₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a heterocyclic ring, an aryl group or a group defined by Rf. R ₁ , R ₂ , R ₃ and Rf may each have a substituent other than a fluorine atom. Further, any two or more groups of R ₂ , R ₃ and Rf may be bonded to each other to form a ring structure.

[0023]

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In the formula, A represents a fully or partially fluorinated n-valent organic group. R ₄ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a halogen atom. R ₄ may have a substituent other than a fluorine atom. n represents an integer of 2 to 8.

Examples of the monomer preferably used for the fine particles of the present invention are shown below, but the present invention is not limited to these specific structures.

[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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(Where x is an integer of 1 to 4)

Further, in addition to the above-mentioned fluorine-containing monomer, a monomer containing no fluorine atom may be used in combination for the purpose of controlling the hardness, shape, surface characteristics, particle size, particle size distribution and the like of the particles. There are no particular restrictions on the monomer units that can be used in combination, and any monomer unit that can be copolymerized by ordinary radical polymerization or ionic polymerization can be suitably used. Preferred examples of such monomers include, for example, olefins (ethylene, propylene, isoprene, butadiene, vinyl chloride, vinylidene chloride, 6-hydroxy-1-hexene,
Cyclopentadiene, 4-pentenoic acid, methyl 8-nonenoate, vinylsulfonic acid, trimethylvinylsilane, trimethoxyvinylsilane, etc., unsaturated carboxylic acids and salts thereof (acrylic acid, methacrylic acid, itaconic acid,
Maleic acid, sodium acrylate, ammonium methacrylate, potassium itaconate, etc., esters of β-unsaturated carboxylic acids (methyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate,
2-chloroethyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, methyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, glycerin monomethacrylate, 2-acetoxyethyl methacrylate, phenyl methacrylate, tetrahydrofurfuryl methacrylate, 2-methoxy Ethyl methacrylate, ω-methoxypolyethylene glycol methacrylate (additional moles = 2 to 100), ω-hydroxypolyethylene glycol methacrylate (additional moles = 2 to 100), ω-hydroxypolypropylene glycol methacrylate (additional moles = 2 to 100), 3-N, N-dimethylaminopropyl methacrylate, chloroform -3-N, N, N-trimethylammoniopropyl methacrylate, 2-carboxyethyl methacrylate, 3-sulfopropyl methacrylate, 4-oxysulfobutyl methacrylate, monobutyl maleate, dimethyl maleate, monomethyl itaconate, dibutyl itaconate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-
Amides of unsaturated carboxylic acids (acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N-methyl-N-hydroxyethylmethacrylamide, N-tertbutylacrylamide, N −
tert-octyl methacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N-
(2-acetoacetoxyethyl) acrylamide, N-
Acryloyl morpholine, diacetone acrylamide, itaconic acid diamide, N-methylmaleimide, 2-
Acrylamide-methylpropanesulfonic acid, etc.), unsaturated nitriles (acrylonitrile, methacrylonitrile, etc.), styrene derivatives (styrene, vinyltoluene, p-tertbutylstyrene, methyl vinylbenzoate, α-methylstyrene, p-chloro) Methyl styrene,
Vinylnaphthalene, p-hydroxymethylstyrene, p
-Sodium styrenesulfonate, potassium p-styrenesulfinate, p-aminomethylstyrene, etc.), vinyl ethers (methyl vinyl ether, butyl vinyl ether, methoxyethyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, benzoate) Examples thereof include vinyl acid, vinyl salicylate vinyl chlorovinyl acetate, and the like, and other polymerizable monomers (such as N-vinyl imidazole, 4-vinyl pyridine, and N-vinyl pyrrolidone). However, it is desirable that these monomers are copolymerized and used in a necessary minimum amount which does not increase the refractive index of the particles.

Further, by copolymerizing an arbitrary polyfunctional monomer in addition to the above monofunctional monomer, the hardness of the particles and the swelling with respect to the solvent can be controlled. The polyfunctional monomer to be used is not particularly limited and may be suitably used as long as it is commercially available or has a plurality of polymerizable unsaturated groups in one molecule of the synthesis. From the viewpoint of lowering the refractive index of the low refractive layer to be formed, the polyfunctional monomer may be selected from the fluorine-containing polyfunctional monomers exemplified above. Specific examples of the polyfunctional monomer include, for example, olefins (butadiene, pentadiene, 1,4-divinylcyclohexane, 1,2,5-trivinylcyclohexane and the like), esters of acrylic acid and methacrylic acid (ethylene glycol diacrylate) Ethylene glycol dimethacrylate, 1,4-cyclohexane diacrylate, pentaerythritol tetramethacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolethanetri (meth) acrylate, dipentaerythritol pentamethacrylate, pentaerythritol hexaacrylate, 1,2,4-cyclohexanetetramethacrylate), styrene derivatives (1,4-divinylbenzene, 4-vinylbenzoate) Acid-2-acryloylethyl ester, etc.), vinyl sulfones (divinyl sulfone, etc.), acrylamides (methylenebisacrylamide, diacryloylpiperazine, etc.), methacrylamides (methylenebismethacrylamide, dimethacryloylpiperazine, etc.) and the like. Can be.

Particles made of a polymer of a fluorine-containing monomer have a core-shell structure comprising a core portion containing a large amount of fluorine atoms and contributing to lowering the refractive index of the material, and a shell portion having a relatively low content of fluorine atoms. It is preferable to have
For this reason, the shell portion may have a functional group such as an acryloyl group, an epoxy group, or an isocyanate group on the surface of the shell portion so that the adhesion between the fine particles or between the fine particles and the lower layer can be improved. .

Hereinafter, examples of the polymer fine particles used in the present invention will be described. The present invention is not limited to these specific structures. () Indicates the weight% of each monomer component in the polymer. FP-1 A copolymer of FM-2 / 1,4-divinylbenzene (85/15). Average particle size = 47 nm. FP-2 A polymer of FM-27. Average particle size = 49 nm. FP-3 A copolymer of FM-1 / methyl methacrylate / 1,2,4-cyclohexanetrimethacrylate (75/15/10). Average particle size = 43 nm. FP-4 A copolymer of FM-4 / methyl methacrylate / ethylene glycol diacrylate (60/15/15). Average particle size = 47 nm. FP-5 FM-3 / FM-5 / divinylbenzene (60/20 /
20) The copolymer of). Average particle size = 45 nm. FP-6 A copolymer of FM-25 / FM-27 (60/40). Average particle size = 45 nm. FP-7 FM-3 / FM-5 / 2-hydroxyethyl acrylate / 1,2,5-trivinylcyclohexane (60/2
0/10/10) copolymer. Average particle system = 38 nm.

FP-8 A copolymer of FM-4 / FM-14 / acrylic acid / methylenebisacrylamide (60/10/5/25). Average particle size = 33 nm. FP-9 FM-4 / 2-hydroxyethyl methacrylate / 1
Copolymer of 4-divinylbenzene (75/5/20). Average particle size = 33 nm. FP-10 A copolymer of FM-4 / FM-24 / 2-hydroxyethyl methacrylate (75/5/20). Average particle size = 39 nm. FP-11 A copolymer of FM-4 / FM-14 / methacrylic acid / 1,2,4-cyclohexanetrimethacrylate / methylenebisacrylamide (60/10/5/25). Average particle size = 33 nm. FP-12 FM-14 / Monomethyl itaconate / NK ESTER
A copolymer of M40G (manufactured by Shin-Nakamura Chemical) / pentaerythritol tetraacrylate (80/5/5/10). Average particle size = 31 nm. FP-13 FM-24 / PE350G (manufactured by NOF Corporation) (90/1
0) Copolymer. Average particle size = 29 nm. A copolymer of FP-14 FM-24 / pentaerythritol tetraacrylate / PP-800 (manufactured by NOF Corporation) (80/15/5). Average particle size = 33 nm. FP-15 FM-25 / FM-28 / NK ESTER M230
G (manufactured by Shin-Nakamura Chemical Co.) (70/20/10). Average particle size = 29 nm. A copolymer of FP-16 FM-27 / NK ESTER M230G (manufactured by Shin-Nakamura Chemical) (90/10). Average particle size = 27 nm.

The refractive index of the polymer of the fluorine-containing monomer decreases almost linearly in proportion to the content of fluorine atoms, and the refractive index of the low refractive index layer further decreases as the content of microvoids increases. By increasing the content of both, the refractive index of the low refractive index layer can be sufficiently reduced. Therefore, the polymer of the fluorinated monomer is generally 0.1.
The low-refractive-index layer contains a fluorine atom in an amount of 30% by weight or more (preferably 0.30 to 0.75% by weight, particularly 0.35 to 0.75% by weight), and the low refractive index layer generally has a content of 0.05 to 0%. Containing 0.50 volume fraction microvoids and 0.10 to 0.5
0 volume fraction is preferred, and 0.10 to 0.28 volume fraction is particularly preferred.

When fine particles having a monodispersed particle size are closest packed, microvoids of 26% (0.26 volume fraction) are formed between the fine particles.
Increase to 8%. In an actual system (low-refractive index layer), these values are not satisfied because there is a certain distribution of the particle diameter. The porosity also changes depending on the conditions for forming the low-refractive-index layer (that is, the method of fusing the particles and the conditions for fusing). If the content of microvoids is too high, the mechanical strength of the film decreases, so that the volume fraction of microvoids is 0.5%.
It is preferably 0 or less. When a very small amount of a monomer having two or more polymerizable groups is used, the porosity changes depending on the ratio between the monomer and the fine particles. If the microvoids thus formed have a size of several tens to several hundreds of nm (less than the wavelength of light), the material is selected from the viewpoint of the refractive index, and the volume fraction of the formed microvoids is adjusted. By doing so, a transparent film having a target refractive index can be formed.

The monomer having two or more polymerizable groups used in the present invention is not particularly limited as long as it is polymerized by UV, electron beam, heat or the like after forming the fine particle layer. 2
As the addition amount of the monomer having at least two polymerizable groups,
The minimum amount required to obtain adhesion between the fine particles is used,
Generally, it is preferably at most 25% by weight, particularly preferably at most 10% by weight. Examples of monomers having two or more polymerizable groups include, for example, (meth) acrylates (ethylene glycol di (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol Tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethanetri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,4-cyclohexanetetramethacrylate, UV-6300B (manufactured by Nippon Gohsei)
Styrene derivatives (1,4-divinylbenzene,
4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone, etc., vinyl sulfones (divinyl sulfone, etc.), acrylamides (methylenebisacrylamide, etc.), methacrylamides, etc., as well as polyfunctional epoxy compounds (Denacol E
X-313, Denacol EX-521 (both manufactured by Nagase Kasei) and the like are preferably used, but not particularly limited thereto. Alternatively, a bifunctional acrylate compound having, for example, an isocyanate group in one molecule (eg, UV-8000B (manufactured by Nippon Synthetic Chemical)) can also be preferably used.
In addition, these monomers having a polymerizable group are a polymerization initiator (IRGACURE 907 (manufactured by Nippon Ciba Geigy Co., Ltd., K
AYACURE EPA (manufactured by Nippon Kayaku), photopolymerization accelerators (KAYACURE EPA, KAYACURE)
DETX (both manufactured by Nippon Kayaku), etc., cationic photopolymerizer (CYRACURE UVI-6990, UVI-
6974 (both manufactured by Union Carbide), diphenyliodonium hexafluorophosphate (manufactured by Tokyo Kasei), RHODORSIL PHOTOINITIAT
It is preferably used in combination with a compound that promotes polymerization, such as OR 2074 (Rhone Poulin Japan).

A small amount of a polymer binder can be further added to the low refractive index layer. However, it is necessary to use the minimum amount necessary for obtaining the adhesion between the fine particles so as not to overfill the microvoids formed between the fine particles. Preferred examples of the binder include a water-soluble resin such as polyvinyl alcohol and polyoxyethylene; an acrylic resin such as polymethyl methacrylate and polymethyl acrylate; a cellulose derivative such as diacetyl cellulose and nitrocellulose; a polyester; an alkyd resin; Polymer,
Examples thereof include, but are not particularly limited to, urethane resins, various curing agents for curing them, and compositions having a curable functional group.

Further, an organic-substituted silicon-based compound can be included therein. These silicon compounds have the general formula:

R ₁₁ aR ₁₂ bSiX _{4- (a + b)} (where R ₁₁ and R ₁₂ are each an alkyl group, an alkenyl group, an allyl group, or a carbon substituted with halogen, epoxy, amino, mercapto, methacryloyl or cyano, respectively) X represents a hydrogen group, X represents a hydrolyzable group selected from an alkoxyl group, an alkoxyalkoxyl group, a halogen atom and an acyloxy group, and under the condition that a + b is 1 or 2, a and b each represent 0, 1
Or 2. ) Or a hydrolysis product thereof.

When the fine particles comprising the polymer of the fluorine-containing monomer are an aqueous dispersion, the use of the above water-soluble resin is preferred. When the fine particles made of the polymer of the fluorine-containing monomer are dispersed in an organic solvent, the fine particles are sufficiently dissolved in the solvent used, have an affinity for the fine particles and the support, and have high transparency (that is, the acrylic resin). Resins and cellulose derivatives) are preferably used.

Preferred inorganic compounds of the inorganic fine particles dispersed in the medium refractive index layer include oxides of metal elements such as aluminum, titanium, zirconium, antimony, zinc and tin. These compounds are
It is commercially available in particulate form, ie, as a powder or as a colloidal dispersion in water and / or other solvents. These can be further mixed and dispersed in the above-mentioned organic material or organosilicon compound for use.

In addition, it is capable of forming a film and can be dispersed in a solvent.
Inorganic materials that are liquid themselves (eg, alkoxides of various elements, salts of organic acids, coordination compounds (eg, chelate compounds) bonded to coordination compounds, and active inorganic polymers) can be given. Preferred examples of these include titanium tetraethoxide, titanium tetra-i-propoxide,
Titanium tetra-n-propoxide, titanium tetra-n-
Butoxide, titanium tetra-sec-butoxide, titanium tetra-tert-butoxide, aluminum triethoxide, aluminum tri-i-propoxide, aluminum tributoxide, antimony triethoxide, antimony tributoxide, zirconium tetraethoxide,
Zirconium tetra-i-propoxide, zirconium tetra-n-propoxide, zirconium tetra-n-
Metal alcoholate compounds such as butoxide, zirconium tetra-sec-butoxide and zirconium tetra-tert-butoxide; diisopropoxytitanium bis (acetylacetonate), dibutoxytitanium bis (acetylacetonate), diethoxytitanium bis (acetylacetate) Chelate compounds such as bis (acetylacetonate zirconium), aluminum acetylacetonate, aluminum di-n-butoxide monoethylacetoacetate, aluminum di-i-propoxide monomethylacetoacetate and tri-n-butoxide zirconium monoethylacetoacetate. And an active inorganic polymer containing zirconyl ammonium carbonate or zirconium as a main component. In addition to those described above, various alkyl silicates or hydrolysates thereof, particularly fine particles of silica, particularly silica gel dispersed in a colloidal form can be used as those having a relatively low refractive index but which can be used in combination with the above compounds. .

These inorganic fine particles have an average particle size of 10 to 100 n.
Preferably, m is dispersed. Average particle size 100 n
If it exceeds m, the scattering intensity increases, the film itself becomes white, and the transparency decreases. Specifically, it is necessary to suppress the haze value of the coating to 3% or less.

As the monomer having two or more polymerizable groups and the polymer binder used for the middle refractive layer, the same ones as used for the low refractive index layer can be used. Further, a polymer binder having a relatively high refractive index as an organic material, for example, a thermoplastic resin (eg, polystyrene,
Polystyrene copolymer, polycarbonate, polymer having an aromatic ring, heterocycle, alicyclic group other than polystyrene, or polymer having a halogen group other than fluorine); thermosetting resin composition (eg, melamine resin, phenol resin) Or a resin composition using an epoxy resin or the like as a curing agent); a urethane-forming composition (eg, a combination of an alicyclic or aromatic isocyanate and a polyol); and a radically polymerizable composition (the above compound (eg, polymer)) A composition containing a modified resin or a prepolymer, which is capable of radical curing by introducing a double bond into it. Materials having high film forming properties are preferred.

Since the refractive index required for the high refractive index layer is 1.90 to 2.20, at least anatase type titanium oxide (refractive index 2.52) or rutile type titanium oxide (refractive index 2.76) among the inorganic fine particles dispersed in the organic binder. However, there is no particular limitation on using the inorganic fine particles and the inorganic material shown in the middle refractive index layer together. Polymerizable binder,
As the polymer binder, the same one as used for the medium refractive index layer can be used.

The transparent substrate used in the present invention is usually a transparent film. Examples of the material for forming the transparent film include cellulose derivatives (eg, diacetyl cellulose, triacetyl cellulose (TAC), propionyl cellulose,
Butyrylcellulose, acetylpropionylcellulose and nitrocellulose), polyamide, polycarbonate (eg, those described in U.S. Pat. No. 3,023,101), polyester (polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, poly-1,4-cyclohexanediene) Methylene terephthalate, polyethylene-1,2-diphenoxyethane-
4,4'-dicarboxylate and JP-B-48-404
No. 14), polystyrene, polyolefins (eg, polyethylene, polypropylene and polymethylpentene), polymethylmethacrylate, syndiotactic polystyrene, polysulfone, polyethersulfone, polyetherketone, polyetherimide and polyoxyethylene Can be mentioned. Triacetyl cellulose, polycarbonate and polyethylene terephthalate are preferred. The refractive index of the transparent film is preferably from 1.40 to 1.60.

The antireflection film of the present invention can be treated so that the surface has an antiglare function (that is, a function of scattering incident light on the surface to prevent a scene around the film from shifting to the film surface). . For example, an antireflection film having such a function forms fine irregularities on the surface of a transparent film, and forms an antireflection film (eg, a low refractive index layer, etc.) on the surface.
Is obtained. The formation of the fine irregularities is performed, for example, by forming a layer containing inorganic or organic fine particles on the surface of the transparent film. Or,
Different from fine particles consisting of a polymer of a fluorine-containing monomer,
Fine particles having a particle diameter of 50 nm to 2 μm are introduced into the coating solution for forming a low refractive index layer in an amount of 0.1 to 50% by weight of the fine particles comprising a polymer of a fluorine-containing monomer, and the fine particles have Irregularities may be formed. Anti-reflection coatings having anti-glare function (ie, anti-glare treatment) generally have a haze of 4 to 40%.

The antireflection film of the present invention (preferably an antireflection film having an antiglare function) is used for a liquid crystal display (LC).
D), an image display device such as a plasma display (PDP), an electroluminescence display (ELD), and a cathode ray tube display (CRT).
In the image display device having such an antireflection film, reflection of incident light is prevented, and visibility is remarkably improved. A liquid crystal display (LCD) provided with the antireflection film of the present invention has, for example, the following configuration. A liquid crystal cell comprising a pair of substrates having transparent electrodes and a liquid crystal sealed between them, and a liquid crystal display device comprising a polarizing plate disposed on both sides of the liquid crystal cell, wherein at least one of the polarizing plates has a surface of the present invention. A liquid crystal display device having an anti-reflection film.

In the present invention, a hard coat layer, an antistatic layer and the like as an intermediate layer may be provided on a transparent film. As the hard coat layer, in addition to acrylic-based, urethane-based, and epoxy-based polymers and / or oligomers and monomers (eg, ultraviolet curable resins), silica-based materials can be used alone or in combination.

At least one optional lubricant may be added to the low refractive index layer of the present invention in order to impart a slip property to the surface and improve the scratch resistance. There is no particular limitation on the lubricant, and for example, polyorganosiloxanes such as silicone oil (polydimethylsiloxane, polydiethylsiloxane, polydiphenylsiloxane, polymethylphenylsiloxane, alkyl-modified polydimethylsiloxane, etc.),
Natural wax (carnauba wax, candelilla wax, jojoba oil, rice wax, wood wax, beeswax, lanolin, whale wax, montan wax), petroleum wax (paraffin wax, microcrystalline wax, etc.), or polyethylene wax as synthetic wax , Fischer-Tropsch wax, higher fatty acid amides (stearic acid amide, oleic acid amide, N,
N'-methylenebisstearic acid amide, etc.), higher fatty acid esters (methyl stearate, butyl stearate, glycerin monostearate, sorbitan monooleate, etc.), metal salts of higher fatty acids (zinc stearate, etc.), represented by the following general formula The fluorinated lubricants (linear perfluoropolyethers, side chain perfluoropolyethers, etc.) and their derivatives (alcohol-modified perfluoropolyethers, isocyanate-modified perfluoropolyethers, etc.) can be exemplified. .

In the present invention, a lubricating layer having a thickness of 50 nm or less using at least one of the above lubricants on the low refractive index layer in order to impart a slipperiness to the surface and improve scratch resistance. May be provided. The lubricant layer may be used in combination with a suitable polymer or the like to impart film forming properties. The thickness of the lubricant layer must be sufficiently smaller than the wavelength of light so as not to affect the reflection characteristics of the porous fluoropolymer layer in the present invention. Therefore, the thickness is preferably 10 nm or less. Also, since the surface must be completely covered with at least a monolayer of lubricant,
The thickness is preferably 2 nm or more.

The medium refractive index layer, the high refractive index layer, the low refractive index layer, the intermediate layer, and the lubricating layer of the present invention can be formed by a generally known method such as a dip coating method, an air knife coating method, and the like.
Curtain coating, roller coating, wire bar coating, gravure coating, or US Pat. No. 2,68
It can be applied by an extrusion coating method using a hopper described in Japanese Patent No. 1,294, specification.
Also, if necessary, U.S. Pat. No. 2,761,791,
No. 3,508,947, 2,941,898 and 3,526,528, two or more layers according to the method described in Yuji Harazaki, “Coating Engineering”, p. 253 (published by Asakura Shoten in 1973). Layers can be applied simultaneously.

[0056]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Example 1 (1) Preparation of Antistatic Conductive Fine Particles A 1N aqueous sodium hydroxide solution having a pH of 3 was added to an ethanol solution containing 7% by weight of stannic chloride hydrate and 0.7% by weight of antimony trichloride. , To obtain a coprecipitate of colloidal stannic oxide and antimony oxide. The obtained precipitate was left at 50 ° C. for 24 hours to obtain a red-brown colloidal precipitate. Further water is added to the precipitate to remove excess ions,
The red-brown colloidal precipitate was washed with water by centrifugation. This colloidal precipitate was redispersed in water and a 15% by weight dispersion was sprayed into an incinerator heated to 600 ° C. to obtain a primary particle size of 0.1%.
A fine powder of tin oxide / antimony oxide composite of 005 μm was obtained. (2) Coating of hard coat layer 25 parts by weight of dipentaerythritol hexaacrylate, 25 parts by weight of urethane oligomer (trade name: UV-
6300B (manufactured by Nippon Gohsei), 2 parts by weight of a photopolymerization initiator (trade name: Irgacure 907 (manufactured by Ciba Geigy)) and 1 part by weight of a photosensitizer (trade name: KAYACUR)
E DETX (manufactured by Nippon Kayaku) was dissolved in 50 parts by weight of toluene, and then 10 parts by weight of the conductive fine particles were dispersed by a horizontal sand mill to prepare a hard coat layer coating solution.
This coating solution was applied to a TAC film having a thickness of 90 μm using a bar coater at room temperature, and dried at 95 ° C.
Immediately 1 minute UV using 12W / cm high pressure mercury lamp
Irradiation and crosslinking were performed to form a 7.1 μm-thick conductive hard coat layer. (3) Coating of middle refractive index layer 2 parts by weight of titanium oxide particles (Ishihara Sangyo TTO-51)
A) 3 parts by weight of PHOSPHANOL RD-720
(Toho Chemical) 5 parts by weight of dipentaerythritol hexaacrylate was mixed with 50 parts by weight of toluene and 40 parts by weight of cyclohexanone.
The mixture was dispersed for a time to prepare a dispersion of titanium oxide. 0.
2 parts by weight of a photopolymerization initiator (trade name: Irgacure 907)
(Manufactured by Ciba-Geigy)) and 0.05 parts by weight of a photosensitizer (trade name: KAYACURE DETX (manufactured by Nippon Kayaku)), and applied onto the hard coat layer using a spin coater, and dried at 115 ° C. Thereafter, ultraviolet irradiation was performed to form a medium refractive index layer (refractive index: 1.68, layer thickness: 76 nm).

(4) Coating of High Refractive Index Layer 8 parts by weight of titanium oxide particles (Ishihara Sangyo TTO-51)
A) 1.7 parts by weight of PHOSPHANOL RD-7
20 (manufactured by Toho Chemical), 0.3 parts by weight of pentaerythritol tetraacrylate, 50 parts by weight of toluene, 40 parts by weight
After mixing with parts by weight of cyclohexanone, the mixture was dispersed in a ball mill for 24 hours to prepare a dispersion of titanium oxide. 0.2 parts by weight of a photopolymerization initiator (trade name: Irgacure 907 (manufactured by Ciba Geigy)) and 0.05 parts by weight of a photosensitizer (trade name: Kayacure-DETX (manufactured by Nippon Kayaku)) are added thereto. Then, it is applied using a spin coater on the middle refraction layer formed above, dried at 115 ° C., and then irradiated with ultraviolet rays.
A high refractive index layer (refractive index: 2.10, layer thickness: 121 nm) was formed. (5) Coating of low refractive index layer Hexafluoroisopropyl methacrylate (FM-
4) A polymer of a fluorine-containing monomer obtained by emulsion copolymerization of 1,4-divinylbenzene / 2-hydroxyethyl methacrylate / methacrylic acid (weight ratio 75/20/3)
/ 2) (average particle size: 30 nm, refractive index:
1.422) and dipentaerythritol hexaacrylate (refractive index: 1.535) to obtain a coating solution (solid content: 1% by weight; fine particles made of a polymer of a fluorine-containing monomer / binder = 84/16). , Weight ratio) on the high refractive index layer using a spin coater, and drying at 115 ° C., and then irradiating the coating film with ultraviolet light, thereby comprising fine particles composed of a polymer of a fluorine-containing monomer and a very small amount of a binder. A low refractive index layer having a thickness of 91 nm was formed. The refractive index (nlayer) of the low refractive index layer is calculated from the reflectance (R) of the film obtained by coating the low refractive index layer on a separately prepared TAC film and the refractive index (nbase) of the TAC film (transparent support) as follows. I asked more.

[0058]

(Equation 1)

The volume fraction of microvoids in the low refractive index layer (V
layer) was determined from the following formula from the refractive index (nlayer) of the low refractive index layer and the refractive index (nbase) of the TAC film. Vla
yer = (nlayer-nbase) / (1-nbase) The refractive index of the film was 1.397, suggesting that it contained microvoids of about 0.11 volume fraction. (5) Evaluation of antireflection effect The reflectance characteristic of the coating film formed in (4) was measured by a spectrophotometer (V-550 manufactured by JASCO Corporation) on the surface of the optical material on the low refractive index layer side in a wavelength region of 400 to 700 nm. Incident angle of 5
The reflectance in ° was measured. Its performance is less than 0.2% reflectivity in the wavelength range of 450 nm to 650 nm, and 400 to 450 nm, 650 to 700 n.
It is less than 1.0% in the wavelength region of m, and it has been found that it has a performance equal to or higher than that of a conventional multi-layer antireflection film formed by physical vapor deposition. (6) Evaluation of film strength After humidifying the film of (4) at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, a sapphire needle with a tip of 0.05 mmR was vertically applied to the surface of the low refractive index layer, and the length was 10 cm. 0 to 100g
Was scratched at a speed of 60 cm / min so that the continuous load was obtained. This sample was visually observed on a light table, and the load at which scratches began to appear was defined as the scratch strength. The scratch strength was about 50 g, and had a film strength equivalent to a multilayer antireflection film formed by physical vapor deposition. In addition, JIS54
When scratched with a pencil hardness tester described in No. 00, the film had a film strength of 3H and was found to have sufficient strength. Further, the film was scratched with # 0000 steel wool at a pressure of 100 g / cm ² at a speed of 60 cm / min, but no scratch was observed, indicating that the film had sufficient scratch resistance.

Example 2 (1) Coating of Hard Coat Layer 25 parts by weight of dipentaerythritol hexaacrylate, 25 parts by weight of a urethane oligomer (trade name: UV-
1700B (manufactured by Nippon Gohsei), 3 parts by weight of a photopolymerization initiator (trade name: Irgacure 907 (manufactured by Ciba Geigy)) and 1 part by weight of a photosensitizer (trade name: KAYACUR)
After E DETX (manufactured by Nippon Kayaku) was dissolved in 50 parts by weight of toluene, 10 parts by weight of the conductive fine particles described in Example 1 were dispersed by a horizontal sand mill to prepare a coating solution for a hard coat layer. This coating solution is coated with P having a thickness of 100 μm.
Apply to ET film with bar coater at room temperature, 12
Immediately after drying at 5 ° C., UV irradiation was performed for 1 minute using a high-pressure mercury lamp of 12 W / cm, followed by crosslinking to form a conductive hard coat layer having a thickness of 7.0 μm. (2) Coating of middle refractive index layer 6 parts by weight of titanium oxide particles (Ishihara Sangyo TTO-51)
A), 9 parts by weight of PHOSPHANOL RD-720
After mixing 15 parts by weight of dipentaerythritol hexaacrylate with 70 parts by weight of toluene, the mixture was dispersed in a ball mill for 24 hours to prepare a titanium oxide dispersion. 0.2 parts by weight of a photopolymerization initiator (trade name: Irgacure 907 (manufactured by Ciba Geigy)) and 0.0 parts by weight
5 parts by weight of a photosensitizer (trade name: Kayacure-DETX)
(Manufactured by Nippon Kayaku)), applied onto the hard coat layer using a spin coater, dried at 120 ° C., and then irradiated with ultraviolet light to obtain a medium refractive index layer (refractive index: 1.68, layer thickness: 23).
5 nm). (3) Coating of high refractive index layer 7 parts by weight of titanium oxide particles (Ishihara Sangyo TTO-51)
A), 2.5 parts by weight of PHOSPHANOL RD-7
After mixing 20 parts (manufactured by Toho Chemical Co., Ltd.) and 0.5 parts by weight of dipentaerythritol hexaacrylate with 90 parts by weight of toluene, the mixture was dispersed in a ball mill for 24 hours to prepare a dispersion of titanium oxide. 0.2 parts by weight of a photopolymerization initiator (trade name: Irgacure 907 (manufactured by Ciba Geigy)) and 0.05 parts by weight of a photosensitizer (trade name: Kayacure-DE)
TX (manufactured by Nippon Kayaku)) is applied onto the middle refractive layer formed above using a spin coater, dried at 120 ° C., and then irradiated with ultraviolet rays to form a high refractive index layer (refractive index: 2.1).
0, layer thickness: 124 nm).

(4) Coating of Low Refractive Index Layer Hexafluoroisopropyl methacrylate (FM-
4) A polymer of a fluorine-containing monomer obtained by emulsion copolymerization of 1,4-divinylbenzene / 2-hydroxyethyl acrylate / methacrylic acid (weight ratio 75/20/3 /
Fine particles composed of 2) (average particle diameter: 30 nm, refractive index:
1.4420) and dipentaerythritol hexaacrylate (refractive index: 1.535) to obtain a coating solution (solid content: 1% by weight; fine particles composed of a polymer of a fluorine-containing monomer / binder = 84/16). , Weight ratio) on the high refractive index layer using a spin coater, and drying at 120 ° C., and then irradiating the coating film with ultraviolet light, thereby comprising fine particles composed of a polymer of a fluorine-containing monomer and a very small amount of a binder. A low refractive index layer having a thickness of 91 nm was formed. The refractive index of the low refractive index layer (nlayer) and the volume fraction of microvoids (V
layer) was determined in the same manner as in Example 1 from the reflectance (R) of a film obtained by coating a low refractive index layer on a separately prepared TAC film and the refractive index (nbase) of the TAC film (transparent support). The refractive index of the film was 1.410, suggesting that it contained microvoids of about 0.08 volume fraction. (5) Evaluation of antireflection effect The reflectance characteristics of the coating film formed in the same manner as in Example 1 were measured. Its performance was less than 0.5% in the wavelength region of 450 nm to 700 nm, and it was found that it had performance equal to or higher than that of a conventionally used multi-layer antireflection film formed by physical vapor deposition. (6) Evaluation of film strength In the same manner as in Example 1, the film was subjected to a sapphire needle scratching strength, a pencil hardness tester, and a steel wool rubbing test. The sapphire needle scratching strength was about 50 g, the pencil hardness was 3H, no scratch was observed in a steel wool rub test, and it was found that the steel had sufficient scratch resistance.

Comparative Example 1 The following medium refractive index layer, high refractive index layer, and low refractive index layer were applied on the hard coat coating material described in Example 1 in the same manner as in Example 1, and the same evaluation was performed. went. (1) Coating of middle refractive index layer 7 parts by weight of titanium oxide particles (Ishihara Sangyo TTO-51)
A), 8 parts by weight of PHOSPHANOL RD-720
After mixing 15 parts by weight of dipentaerythritol hexaacrylate with 70 parts by weight of toluene, the mixture was dispersed in a ball mill for 24 hours to prepare a titanium oxide dispersion. 0.2 parts by weight of a photopolymerization initiator (trade name: Irgacure 907 (manufactured by Ciba Geigy)) and 0.0 parts by weight
5 parts by weight of a photosensitizer (trade name: Kayacure-DETX)
(Manufactured by Nippon Kayaku)), applied onto the hard coat layer by using a spin coater, dried at 120 ° C., and then irradiated with ultraviolet rays to obtain a medium refractive index layer (refractive index: 1.73, layer thickness: 23).
5 nm). (2) Coating of high refractive index layer 7 parts by weight of titanium oxide particles (Ishihara Sangyo TTO-51)
A), 2.5 parts by weight of PHOSPHANOL RD-7
After mixing 20 parts (manufactured by Toho Chemical Co., Ltd.) and 0.5 parts by weight of dipentaerythritol hexaacrylate with 90 parts by weight of toluene, the mixture was dispersed in a ball mill for 24 hours to prepare a dispersion of titanium oxide. 0.2 parts by weight of a photopolymerization initiator (trade name: Irgacure 907 (manufactured by Ciba Geigy)) and 0.05 parts by weight of a photosensitizer (trade name: Kayacure-DE)
TX (manufactured by Nippon Kayaku)) is applied onto the above-formed middle refractive layer using a spin coater, dried at 120 ° C., and then irradiated with ultraviolet rays to form a high refractive index layer (refractive index: 2.1).
0, layer thickness: 124 nm).

(3) Coating of Low Refractive Index Layer Hexafluoroisopropyl methacrylate (FM-
4) Emulsion copolymerization of 1,4-divinylbenzene / 2-hydroxyethyl acrylate / methacrylic acid (weight ratio 7
5/20/3/2) (fine particles comprising a polymer of a fluorine-containing monomer (average particle size: 30 nm, refractive index:
1.4420) and dipentaerythritol hexaacrylate (refractive index: 1.535) to obtain a coating solution (solid content: 1% by weight; fine particles composed of a polymer of a fluorine-containing monomer / binder = 84/16). , Weight ratio) on the high refractive index layer using a spin coater, and drying at 120 ° C., and then irradiating the coating film with ultraviolet light, thereby comprising fine particles composed of a polymer of a fluorine-containing monomer and a very small amount of a binder. A low refractive index layer having a thickness of 91 nm was formed. The refractive index of the low refractive index layer (nlayer) and the volume fraction of microvoids (V
layer) was determined in the same manner as in Example 1 from the reflectance (R) of a film obtained by coating a low refractive index layer on a separately prepared TAC film and the refractive index (nbase) of the TAC film (transparent support). The refractive index of the film was 1.410, suggesting that it contained microvoids of about 0.08 volume fraction. (4) Evaluation of antireflection effect The reflectance characteristics of the coating film formed in the same manner as in Example 1 were measured. The performance was 0.1 to 0.7% in the wavelength region of 450 nm to 700 nm, and it was found that the reflectance was inferior to the conventional multi-layer antireflection film formed by physical vapor deposition at some wavelengths.

Comparative Example 2 A low refractive index layer was applied in the same manner as in Example 1 on the hard coat layer, medium refractive index layer, and high refractive index layer coated product described in Example 1, and the same evaluation was performed. Was. (1) Coating of low refractive index layer Hexafluoroisopropyl methacrylate (FM-
4) Fine particles comprising a polymer of a fluorine-containing monomer obtained by emulsion copolymerization of 1,4-divinylbenzene / hydroxyethyl acrylate / methacrylic acid (average particle size: 3
0 nm, refractive index: 1.420) and Aronix M-1
01 (refractive index: 1.545) was mixed with a coating liquid (solid content: 1% by weight; fine particles made of a polymer of a fluorine-containing monomer / binder = 84/16, weight ratio) to a high refractive index layer. A low-refractive-index layer having a thickness of 91 nm formed of fine particles composed of a polymer of a fluorine-containing monomer and a very small amount of a binder is formed by applying a spin coater thereon, drying the coating film at 120 ° C., and then irradiating the coating film with ultraviolet rays. did. The refractive index of the low refractive index layer (nlayer) and the volume fraction of microvoids (Vlaye
r) was determined in the same manner as in Example 1 from the reflectance (R) of a film in which a low refractive index layer was coated on a separately prepared TAC film and the refractive index (nbase) of the TAC film (transparent support).
The refractive index of the film was 1.420, suggesting that it contained microvoids of about 0.09 volume fraction. (2) Evaluation of film strength In the same manner as in Example 1, the film was subjected to a sapphire needle scratching strength, a pencil hardness tester, and a steel wool rubbing test. The sapphire needle scratching strength was about 30 g, the pencil hardness was H, and scratches were observed in a steel wool rub test. It was found that the scratch resistance was clearly inferior to those of the examples.

Example 3 (1) Preparation of Antireflection Polarizing Plate Using the antireflection film prepared in Example 1, a polarizing plate was prepared with the surface on which the antireflection layer was applied facing upward. (2) Mounting on LCD TVs Sharp Corporation's TFT LCD color TV 6E-C3
The polarizing plate was peeled off and the polarizing plate was peeled off and the polarizing plate was attached so that the polarizing axis would be the same. (3) Evaluation of antireflection effect The reflectance characteristics of the liquid crystal television in black display were measured in the same manner as in Example 1. Its performance was less than 0.5% in the wavelength region of 450 nm to 700 nm, and it was found that it had performance equal to or higher than that of a conventionally used multi-layer antireflection film formed by physical vapor deposition. (4) Evaluation of Film Strength In the same manner as in Example 1, the film was subjected to a sapphire needle scratching strength, a pencil hardness tester, and a steel wool rubbing test. The sapphire needle scratching strength was about 50 g, the pencil hardness was 3H, no scratch was observed in a steel wool rub test, and it was found that the sapphire needle had sufficient strength as a member of a liquid crystal television.

Comparative Example 3 TFT type liquid crystal color television 6E-C3 manufactured by Sharp Corporation
Was peeled off, and the polarizing plate (manufactured by Sanritz) was peeled off, and the polarizing plate was attached so that the polarizing axis was the same. The reflectance and the strength were evaluated in the same manner as in Example 3. (1) Evaluation of Antireflection Effect The reflectance characteristics of the liquid crystal television in black display were measured in the same manner as in Example 1. Its performance was 5.2% in the wavelength region of 450 nm to 700 nm, which was clearly worse than that without the antireflection film. (2) Evaluation of film strength In the same manner as in Example 1, the film was subjected to a sapphire needle scratching strength, a pencil hardness tester, and a steel wool rubbing test. The sapphire needle scratching strength was about 50 g, the pencil hardness was 3H, no scratch was observed in a steel wool rub test, and it was found that the sapphire needle had sufficient strength as a member of a liquid crystal television.

[0067]

[Table 1]

Embodiment 4 (1) Mounting on CRT CRT (Muliscan17sF) manufactured by Sony Corporation
The antireflection film prepared in Example 2 was stuck on one half of the surface with a commercially available acrylic pressure-sensitive adhesive. (2) Evaluation of Antireflection Effect The CRT was displayed in black, and the screen was observed by irradiating 600 cd / m2 light at an angle of 10 degrees from the perpendicular direction. The above C
RT does not show the shape of the light source on the surface on which the antireflection film is not applied because it has been subjected to anti-glare treatment, but the entire screen becomes whitish, and a clear decrease in black luminance was observed. On the other hand, on the half surface where the anti-reflection film was bonded, the rate of reduction in black luminance was clearly better than that of the surface where the anti-reflection film was not bonded, indicating that the anti-reflection film had sufficient performance.

[0069]

As is clear from Table 1, a medium refractive index layer, a high refractive index layer and a low refractive index layer were formed on at least one of the surfaces of the transparent substrate in order from the substrate side to the air surface. An anti-reflection film, wherein each layer has at least one kind of 2
A polymer comprising a monomer having at least two polymerizable groups, wherein the middle refractive index layer contains at least one metal oxide selected from aluminum, titanium, zirconium, antimony, zinc and tin, and has a high refractive index The layer contains titanium oxide, the low refractive index layer contains fine particles made of a polymer of a fluorine-containing monomer and microvoids that do not scatter light,
By strictly defining the refractive index and the film thickness of each layer, it is possible to form an antireflection film having excellent strength, which is superior to that of a multilayer inorganic vapor deposition antireflection film, by coating.

[Brief description of the drawings]

FIG. 1 shows a typical example of an antireflection film of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low refractive index layer 2 Fluorine-containing fine particles 3 Microvoid 4, 7, 10 Binder 5 High refractive index layer 6, 9 Metal oxide fine particles 8 Medium refractive index layer 11 Hard coat layer 12 Transparent film

Claims (6)

[Claims] 1. An antireflection film having a middle refractive index layer, a high refractive index layer, and a low refractive index layer formed on at least one of the surfaces of a transparent substrate in order from the substrate side to the air surface. Contains a polymer composed of a monomer having at least one kind of two or more polymerizable groups, and the polymer is polymerized after forming each layer, and the medium refractive index layer is formed of aluminum, titanium, zirconium. Containing at least one metal oxide selected from antimony, zinc and tin, the high refractive index layer containing titanium oxide, and the low refractive index layer containing fine particles made of a polymer of a fluorine-containing monomer and microvoids that do not scatter light. An antireflection film, wherein the refractive index and the film thickness of each layer are in the following ranges. Medium refractive index layer n3 = 1.60-1.70 hλ / 4 × 0.8 <n3d3 <hλ / 4 × 1.2 High refractive index layer n2 = 1.90-2.20 kλ / 4 × 0.8 <n2d2 <kλ / 4 × 1 .2 low refractive index layer n1 = 1.37-1.46 .lambda. / 4.times.0.8 <n1d1 <.lambda. / 4.times.1.2 (in the above formula, h represents 1, 2 or 3, and n3 is a medium refractive index. Represents the refractive index of the layer, d3 represents the thickness (nm) of the medium refractive index layer, k represents 1, 2 or 3, n2 represents the refractive index of the high refractive index layer, and d2 represents the high refractive index layer. , N1 represents the refractive index of the low refractive index layer, and d1 represents the layer thickness (nm) of the low refractive index layer.
Λ represents the design wavelength (nm) and is in the range of 500 to 600. ) 2. An antireflection film having a medium refractive index layer, a high refractive index layer, and a low refractive index layer, wherein each layer has a refractive index of a medium refractive index layer, a high refractive index layer, and a low refractive index layer, respectively. 2. The anti-reflection coating according to claim 1, wherein the thickness is in the range of (A), (B) or (C). (A) Medium refractive index layer n3 = 1.60-1.70, d3 = 60-110 nm (A) High refractive index layer n2 = 1.90-2.20, d2 = 90-190 nm (A) Low refractive index layer n1 = 1.37-1.46, d1 (B) Medium refractive index layer n3 = 1.60-1.70, d3 = 180-330 nm (B) High refractive index layer n2 = 1.90-2.20, d2 = 90-190 nm (B) Low refractive index layer n1 = 1.37 1.46, d1 = 70-130 nm (C) Medium refractive index layer n1 = 1.60-1.70, d1 = 60-110 nm (C) High refractive index layer n2 = 1.90-2.20, d2 = 45-90 nm (C) Low refractive index Layer n3 = 1.37-1.46, d3 = 70-130 nm 3. The antireflection film according to claim 1, wherein the volume fraction of the microvoids in the low refractive index layer that does not scatter light is in the range of 0.05 to 0.50. 4. The antireflection film according to claim 1, wherein the fine particles comprising the polymer of the fluorine-containing monomer have a core-shell structure. 5. The haze value of the antireflection film is 3% to 40%.
The antireflection film according to claim 1 or 2, wherein 6. An image display device comprising the antireflection film according to claim 1 or 2.