JP2000066006A - Process for producing antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an antireflection film having the high strength of a low- reflective index layer by a simple method. SOLUTION: A stage for providing the surface of a transparent base 1 with a low-reflective index layer forming material layer, a stage for forming an over-coating layer 6 contg. a fluorine-contained compd. on the low-reflective index layer forming material layer and a stage for polymerizing the monomer of the low-reflective index layer forming material layer are executed in this order. As a result, the antireflection film having the transparent base 1, the low-reflective index layer 5 contg. the polymer formed by the polymn. of the monomer and the over-coating layer 6 contg. the fluorine-contained compd. is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an antireflection film having a transparent support, a low refractive index layer and an overcoat layer.

[0002]

2. Description of the Related Art An antireflection film is used for a liquid crystal display (LC).
D), a plasma display panel (PDP), an electroluminescence display (ELD), and a cathode ray tube display (CRT). As the anti-reflection film, an anti-reflection film in which a transparent thin film of a metal oxide is laminated on a transparent support has been conventionally used. The reason for using a plurality of transparent thin films is to prevent reflection of light of various wavelengths. The transparent thin film of a metal oxide can be formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Usually, it is formed by a vacuum evaporation method, which is a kind of physical evaporation method. The multilayer vapor-deposited film of metal oxide has excellent optical properties as an antireflection film.
Methods for forming an antireflection film by vapor deposition are described in JP-A-60-144702, JP-A-61-245449, JP-A-62-178901 and JP-A-9-197103.

A method of forming an antireflection film by coating instead of vapor deposition has been proposed. The method by coating is slightly inferior to the method by vapor deposition in terms of optical functions, but is characterized by easy production and high productivity. In the coating method, an optically functional layer (low refractive index layer,
The components (materials for forming each layer) of the high refractive index layer and the medium refractive index layer are applied to form an antireflection film. Specifically, the optically functional layers are sequentially formed by repeating the step of applying a monomer and the step of polymerizing the monomer to form a polymer (a binder for each layer). Methods for forming an antireflection film by coating are described in JP-B-60-59250, JP-A-59-50401, JP-A-2-245702,
5-13021, 8-110401 and 8
It is described in each publication of -179123.

[0004]

The low refractive index layer has a problem that the strength is low. It has also been found that when a high refractive index layer is provided between the transparent support and the low refractive index layer, the strength of the low refractive index layer is lower than that of the high refractive index layer. The low refractive index layer is often formed as a layer having a void in order to obtain a low refractive index. The refractive index of air is 1.00, and the layer containing air in the air gap has a very low refractive index. On the other hand, it is certain that the strength of the layer will be weakened by the presence of voids. Therefore, it was considered that the solution of the low-refractive-index layer was not practically possible because the low-refractive-index layer had a low strength due to the formation of voids for obtaining a low refractive index.

However, the present inventor has conducted research and found that one of the causes of the low strength of the low refractive index layer is the existence of voids, but there is another cause. did. As described above, in the method of producing an antireflection film by coating, a low refractive index layer or a high refractive index layer is formed in a step of applying a monomer, and then the monomer is polymerized to form a polymer (a binder for each layer). Is performed. According to the study of the present inventors, in this polymerization reaction, oxygen in the air functions as a polymerization inhibitor. In the high refractive index layer provided between the transparent support and the low refractive index layer, after the step of applying the monomer of the high refractive index layer and the step of polymerizing the monomer of the high refractive index layer, A step of applying a monomer of the low refractive index layer and a step of polymerizing the monomer of the low refractive index layer are performed thereon. Therefore, even if the polymerization reaction of the monomer of the high refractive index layer is inhibited by oxygen in the air and the formation of the polymer is insufficient, in the next step of polymerizing the monomer of the low refractive index layer, The polymerization reaction of the monomer in the high refractive index layer was completed in a state where oxygen in the air was cut off.

On the other hand, in the low refractive index layer provided as the uppermost layer, the step of forming the low refractive index layer is performed while the polymerization reaction of the monomer is inhibited by oxygen in the air and the formation of the polymer is insufficient. It ends. According to the study of the present inventors as described above, the reason that the strength of the low refractive index layer is weaker is that the formation of the polymer that functions as a binder of the low refractive index layer is insufficient, rather than the existence of voids. Turned out to be. An object of the present invention is to produce an antireflection film having a high strength of a low refractive index layer by a simple method.

[0007]

The object of the present invention has been attained by the following methods (1) to (7) for producing an antireflection film. (1) providing a low-refractive-index-layer-forming material layer containing a monomer on a transparent support; and forming an overcoat layer containing a fluorine-containing compound on the low-refractive-index layer-forming material layer;
By performing the step of polymerizing the monomer of the low refractive index layer forming material layer in this order, the transparent support, the low refractive index layer containing the polymer formed by polymerization of the monomer, and the overcoat containing the fluorine-containing compound. A method for producing an antireflection film having a layer. (2) Before the step of providing the low refractive index layer forming material layer, the step of forming the high refractive index layer on the transparent support and the step of providing the low refractive index layer forming material layer are performed on the high refractive index layer ( A method for producing the antireflection film according to 1). (3) In the step of providing the low-refractive-index-layer-forming material layer, fine particles are further added to the low-refractive-index-layer-forming material layer to form voids between or within the fine particles, thereby producing the antireflection film according to (1). how to.

(4) The method according to (1), wherein a step of partially polymerizing the monomer of the low refractive index layer is performed between the step of forming the low refractive index layer forming material layer and the step of forming the overcoat layer. For producing an anti-reflection film of the invention. (5) In the step of forming the overcoat layer, the polymerization initiator generates a gas other than oxygen in the step of further adding a polymerization initiator to the overcoat layer and polymerizing the monomers of the low refractive index layer forming material layer ( A method for producing the antireflection film according to 1). (6) In the step of forming the overcoat layer, a fluorine-containing monomer is used as a fluorine-containing compound, and in the step of polymerizing the monomer of the low refractive index layer-forming material layer, the fluorine-containing monomer is also polymerized to form a fluorine-containing polymer. A method for producing the antireflection film according to (1). (7) The method for producing an antireflection film according to (1), wherein a step of polymerizing the monomer of the low refractive index layer forming material layer by irradiation with an electromagnetic wave or a particle beam is performed. In the present specification, “monomer” means a compound having a polymerizable functional group and capable of undergoing a polymerization reaction (including a crosslinking reaction). Therefore, compounds generally classified as oligomers or polymers can be used as monomers in the present invention as long as they have a polymerizable functional group. Further, in the present specification, the low refractive index layer, the high refractive index layer and the middle refractive index layer are, respectively, "a layer having a refractive index lower than the refractive index of the transparent support", "the refractive index of the transparent support And a layer having a refractive index higher than the refractive index of the transparent support and lower than the refractive index of the high refractive index layer.

[0009]

According to the study of the present inventor, the reason for the low strength of the low refractive index layer is that oxygen in the air functions as a polymerization inhibitor, and therefore the formation of a polymer that functions as a binder for the low refractive index layer is not possible. It turned out to be enough. Therefore, the problem can be solved by performing the step of polymerizing the monomer of the low refractive index layer in a state where oxygen in the air is shut off. As a means for blocking oxygen, various methods (for example,
Use of an oxygen scavenger, execution of a polymerization reaction in a state where air is shut off by a carver sheet, and execution of a polymerization reaction under a nitrogen atmosphere). However, adopting a special means only for the polymerization reaction of the low refractive index layer reduces the productivity and increases the cost as a method of manufacturing the antireflection film. The present inventors proceeded with research and focused on an overcoat layer containing a fluorine-containing compound. The method of providing an overcoat layer containing a fluorine-containing compound on a surface-side layer is generally well known as a measure for protecting the surface layer from dirt and improving scratch resistance. However, when an overcoat layer containing a fluorine-containing compound is to be provided on the low-refractive-index layer having voids, the coating liquid for the overcoat layer penetrates into the voids of the low-refractive-index layer, and the low-refractive-index layer The porosity may decrease. If the porosity of the low refractive index layer decreases, it is expected that the refractive index of the low refractive index layer increases. As a result of further research by the present inventors, even if an overcoat layer containing a fluorine-containing compound is provided on the low-refractive index layer having voids, the material of the overcoat layer occupies the voids of the low-refractive index layer. It has been found that it is possible to lower the percentage. For example, the fluorine-containing compound in the overcoat layer,
When the fine particles of the fluorine-containing compound have a particle diameter of 20 nm or more, the fine particles close the openings of the voids, and the voids of the low refractive index layer are maintained. Also, the gap in the low refractive index layer can be maintained by adjusting the application amount of the overcoat layer to be 80% by volume or less of the gap in the low refractive index layer. Furthermore, it has been found that even if the material of the overcoat layer occupies a considerable amount of space in the low refractive index layer, the refractive index of the low refractive index layer does not increase as expected.

As a result of the research by the present inventors as described above, it has become clear that it is possible to provide an overcoat layer containing a fluorine-containing compound on the low refractive index layer. Therefore, if a step of forming an overcoat layer containing a fluorine-containing compound on the low-refractive-index layer is performed, and then a step of polymerizing the monomer of the low-refractive-index layer is performed, the oxygen in the air is generated by the overcoat layer. The polymerization reaction of the monomer of the low refractive index layer can be advanced in a state where is blocked. For the above reasons, in the method for producing an antireflection film of the present invention, an antireflection film having a high strength of a low refractive index layer can be produced by a simple method. Furthermore, in the manufactured antireflection film, the low refractive index layer is protected from contamination by providing an overcoat layer containing a fluorine-containing compound.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic structure of an antireflection film will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a main layer configuration of the antireflection film. The antireflection film shown in FIG. 1A has a layer structure in the order of a transparent support (1), a low refractive index layer (5), and an overcoat layer (6). The transparent support (1) and the low refractive index layer (5) have a refractive index satisfying the following relationship. Refractive index of low refractive index layer <refractive index of transparent support The antireflection film shown in FIG. 1B includes a transparent support (1), a hard coat layer (2), a low refractive index layer (5),
And it has a layer structure of the order of the overcoat layer (6). The relationship between the refractive index of the transparent support (1) and the refractive index of the low refractive index layer (5) is the same as that of the antireflection film shown in FIG.

The antireflection film shown in FIG. 1C comprises a transparent support (1), a hard coat layer (2), a high refractive index layer (4), a low refractive index layer (5), and an overcoat layer. It has a layer configuration in the order of (6). The transparent support (1), the high refractive index layer (4) and the low refractive index layer (5) have a refractive index satisfying the following relationship. The refractive index of the low refractive index layer <the refractive index of the transparent support <the refractive index of the high refractive index layer The antireflection film shown in FIG.
It has a layer structure of a hard coat layer (2), a medium refractive index layer (3), a high refractive index layer (4), a low refractive index layer (5), and an overcoat layer (6). The transparent support (1), the medium refractive index layer (3), the high refractive index layer (4) and the low refractive index layer (5) have a refractive index satisfying the following relationship. Refractive index of low refractive index layer <refractive index of transparent support <refractive index of medium refractive index layer <refractive index of high refractive index layer

In the most basic embodiment of the present invention, the following steps 10 are performed in this order to produce the anti-reflection film shown in FIG. Providing a low-refractive-index layer-forming material layer containing a monomer on the transparent support; forming an overcoat layer containing a fluorine-containing compound on the low-refractive-index layer-forming material layer; and 10 forming a low-refractive-index layer. Forming a low refractive index layer by polymerizing monomers of the material layer;

As described below, it is preferable to carry out a step between the steps. Providing a low refractive index layer-forming material layer containing a monomer on the transparent support; partially polymerizing the monomer of the low refractive index layer-forming material layer; a fluorine-containing compound on the low refractive index layer-forming material layer And 10) completely polymerizing the monomers of the low refractive index layer forming material layer to form a low refractive index layer.

As described below, the step is more preferably carried out by coating. A step of applying a coating liquid for a low refractive index layer containing a monomer on a transparent support to provide a low refractive index layer forming material layer; a step of partially polymerizing the monomer of the low refractive index layer forming material layer; A step of applying an overcoat layer coating solution containing a fluorine-containing compound on the refractive index layer forming material layer to form an overcoat layer; and 10) completely polymerizing the monomer of the low refractive index layer forming material layer to obtain a low refractive index. Forming a rate layer.

As described below, it is particularly preferable to use a fluorine-containing monomer as the fluorine-containing compound of the overcoat layer. A step of applying a coating liquid for a low refractive index layer containing a monomer on a transparent support to provide a low refractive index layer forming material layer; a step of partially polymerizing the monomer of the low refractive index layer forming material layer; A step of applying a coating liquid for an overcoat layer containing a fluorine-containing monomer on the material layer for forming the refractive index layer and providing the material layer for forming the overcoat layer; and 10 when the monomer of the material layer for forming the low refractive index layer is completely polymerized. Simultaneously polymerizing the fluorine-containing monomer of the overcoat layer forming material layer to form a low refractive index layer and an overcoat layer.

It is particularly preferable that the antireflection film shown in FIG. A step of applying a coating liquid for a hard coat layer containing a monomer on a transparent support to provide a hard coat layer forming material layer; a step of partially polymerizing the monomers of the hard coat layer forming material layer; a hard coat layer forming material Applying a coating liquid for a low refractive index layer containing a monomer on the layer, and providing a low refractive index layer forming material layer; simultaneously forming the hard coat layer by completely polymerizing the monomers of the hard coat layer forming material layer A step of partially polymerizing the monomer of the low-refractive-index-layer-forming material layer; applying a coating solution for an overcoat layer containing a fluorine-containing monomer on the low-refractive-index-layer-forming material layer; Providing a low refractive index layer by completely polymerizing the monomer of the low refractive index layer forming material layer and simultaneously polymerizing the fluorine-containing monomer of the overcoat layer forming material layer; Forming an overcoat layer;

It is particularly preferable that the antireflection film shown in FIG. A step of applying a coating liquid for a hard coat layer containing a monomer on a transparent support to provide a hard coat layer forming material layer; a step of partially polymerizing the monomers of the hard coat layer forming material layer; a hard coat layer forming material A step of applying a coating liquid for a high refractive index layer containing a monomer on the layer and providing a high refractive index layer forming material layer; simultaneously forming the hard coat layer by completely polymerizing the monomers of the hard coat layer forming material layer A step of partially polymerizing the monomer of the high-refractive-index layer-forming material layer; applying a low-refractive-index layer-forming coating solution containing a monomer on the high-refractive-index layer-forming material layer to provide the low-refractive-index layer-forming material layer A step of completely polymerizing the monomer of the high refractive index layer forming material layer to form the high refractive index layer and simultaneously partially polymerizing the monomer of the low refractive index layer forming material layer; Applying a coating solution for an overcoat layer containing a fluorine-containing monomer to the overcoat layer to form an overcoat layer forming material layer; and 10) completely polymerizing the monomer of the low refractive index layer forming material layer and simultaneously forming the overcoat layer forming material layer Forming a low refractive index layer and an overcoat layer by polymerizing the fluorinated monomer.

The anti-reflection film shown in FIG. 1D is particularly preferably manufactured by the following steps 10 to 10. A step of applying a coating liquid for a hard coat layer containing a monomer on a transparent support to provide a hard coat layer forming material layer; a step of partially polymerizing the monomers of the hard coat layer forming material layer; a hard coat layer forming material Applying a coating liquid for a medium refractive index layer containing a monomer on the layer and providing a medium refractive index layer forming material layer; simultaneously forming the hard coat layer by completely polymerizing the monomers of the hard coat layer forming material layer A step of partially polymerizing the monomer of the medium-refractive-index-layer-forming material layer; applying a coating liquid for a high-refractive-index layer containing a monomer on the medium-refractive-index-layer-forming material layer to provide a high-refractive-index-layer-forming material layer A step of completely polymerizing the monomer of the medium-refractive-index layer-forming material layer to form a medium-refractive-index layer and simultaneously partially polymerizing the monomer of the high-refractive-index layer-forming material layer; Applying a coating liquid for a low refractive index layer containing a monomer to a low refractive index layer and providing a low refractive index layer forming material layer; completely forming a high refractive index layer by completely polymerizing the monomers of the high refractive index layer forming material layer; A step of partially polymerizing the monomer of the refractive index layer forming material layer; a step of applying an overcoat layer coating liquid containing a fluorine-containing monomer on the low refractive index layer forming material layer to provide an overcoat layer forming material layer And 10) a step of completely polymerizing the monomer of the low refractive index layer forming material layer and simultaneously polymerizing the fluorine-containing monomer of the overcoat layer forming material layer to form a low refractive index layer and an overcoat layer.

[Transparent Support] As the transparent support, a plastic film is preferably used. Examples of the polymer forming the plastic film 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-cyclohexane dimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin ( For example, polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, Includes polymethyl methacrylate and polyether ketone. Triacetyl cellulose, polycarbonate and polyethylene terephthalate are preferred. The light transmittance of the transparent support is preferably 80% or more, and more preferably 86% or more.
The haze of the transparent support is preferably 2.0% or less, more preferably 1.0% or less. The refractive index of the transparent support is preferably from 1.4 to 1.7.

[Monomer used for each layer] The layers (hard coat layer, middle refractive index layer, high refractive index layer, low refractive index layer, overcoat layer) provided in the antireflection film are all formed by using monomers. And then polymerizing the monomers to form a polymer. The obtained polymer functions as a binder for each layer. The monomer has a polymerizable functional group capable of performing a polymerization reaction (including a crosslinking reaction).
As described above, in the present invention, it is preferable to simultaneously carry out a partial polymerization reaction of a certain layer and a complete polymerization reaction of a layer thereunder. To do so, use a compound having a similar polymerizable functional group as a monomer for each layer, and design an antireflection film so that the polymerization reaction of each layer proceeds by the same treatment (irradiation, particle beam irradiation, or heating). Is preferred. Examples of polymerizable functional groups include ethylenically unsaturated groups,
Includes isocyanate groups, epoxy groups, aziridine groups, oxazoline groups, aldehyde groups, carbonyl groups, hydrazine groups, carboxyl groups, methylol groups and active methylene groups. Ethylenically unsaturated groups are most preferred. Therefore, the monomer of each layer is particularly preferably an ethylenically unsaturated compound.

The nature or molecular structure of the monomer other than the polymerizable functional group is determined according to the function of each layer and the function of the binder of each layer. The hard coat layer is preferably a hard layer in order to impart scratch resistance to the transparent support.
In order to form a hard layer, a crosslinked polymer may be used as a binder. Crosslinked polymers can be formed from polyfunctional monomers. When an ethylenically unsaturated compound is used as a monomer, it is preferable that the monomer has two or more ethylenically unsaturated groups. In the middle refractive index layer and the high refractive index layer, a polymer having a relatively high refractive index can be used as a binder. Examples of high refractive index polymers include cyclic (aromatic, heterocyclic, alicyclic)
Polymers having a group and polymers having a halogen atom other than fluorine as a substituent are included. Such a polymer can be formed from a monomer having a cyclic group or a monomer having a halogen atom other than fluorine as a substituent.
However, when the refractive index of the layer is increased using inorganic fine particles, the refractive index of the polymer may be a relatively low value. In that case, a normal ethylenically unsaturated compound can be used as a monomer. When inorganic fine particles are added to the layer, an anionic group (eg,
It is preferable to use a monomer having carboxyl, sulfo, and phosphono.

In the low refractive index layer, it is preferable to use a polymer having a relatively low refractive index as a binder. Examples of the polymer having a low refractive index include a fluorinated polymer. The fluorine-containing polymer is a fluorine-containing monomer (for example,
(Fluorinated ethylenically unsaturated monomers). However, when the gap is formed to lower the refractive index of the layer, the refractive index of the polymer may be a relatively high value. In that case, a normal ethylenically unsaturated compound can be used as a monomer. In the case where voids are formed in the layer, it is preferable to use a crosslinked polymer as a binder in order to maintain the strength of the layer. Crosslinked polymers can be formed from polyfunctional monomers. When an ethylenically unsaturated compound is used as a monomer, it is preferable that the monomer has two or more ethylenically unsaturated groups. The overcoat layer contains a fluorine-containing compound to protect the surface of the low refractive index layer from contamination. Therefore, the overcoat layer preferably contains a fluorine-containing polymer as a binder. Fluorinated polymers can be formed from fluorinated monomers (eg, fluorine-substituted ethylenically unsaturated monomers). The fluorine-containing polymer has an excellent function of protecting the surface of the low-refractive-index layer from contamination as compared with a normal fluorine-containing compound.

The monomer having two or more ethylenically unsaturated groups is preferably an ester of a polyhydric alcohol and acrylic acid or methacrylic acid. Examples of polyhydric alcohols include ethylene glycol, 1,4-cyclohexanol, pentaerythritol, trimethylolpropane, trimethylolethane, dipentaerythritol, 1,2,4-cyclohexanol, polyurethane polyol and polyester polyol. . Trimethylolpropane, pentaerythritol, dipentaerythritol and polyurethane polyols are preferred. Examples of fluorine-substituted ethylenically unsaturated monomers include:
Fluoroolefin (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-
1,3-dioxole), fluorinated vinyl ethers and esters of fluorinated alcohols with acrylic acid or methacrylic acid. Examples of other ethylenically unsaturated monomers include olefins (eg, ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride),
Monoacrylates (eg, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate), monomethacrylates (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate), styrene and the like Derivatives (eg, styrene, divinylbenzene, vinyltoluene,
α-methylstyrene), vinyl ether (eg, methyl vinyl ether), vinyl ester (eg, vinyl acetate, vinyl propionate, vinyl cinnamate), acrylamide (eg, N-tertbutylacrylamide, N-cyclohexylacrylamide), methacrylamide and Acrylonitrile is included. Two or more ethylenically unsaturated monomers may be combined to form a copolymer or two or more polymers.

[Polymerization Initiator Used for Each Layer] The polymerization initiator is determined according to the type of monomer and the type of polymerization treatment (irradiation of electromagnetic waves, irradiation of particle beams, or heating). Generally, a photopolymerization initiator or a thermal polymerization initiator is used. It is preferable to use a photopolymerization initiator alone or to use a photopolymerization initiator and a thermal polymerization initiator in combination. 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-hydroxydimethylphenylketone, 1-hydroxycyclohexylphenylketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and -Benzyl-2-
Dimethylamino-1- (4-morpholinophenyl)-
Contains butanone. Examples of benzoins include benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of the phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. A photosensitizer may be used in addition to the photopolymerization initiator. Examples of photosensitizers include n-butylamine, triethylamine, tri-n-
Includes butylphosphine, Michler's ketone and thioxanthone.

Examples of the thermal polymerization initiator include inorganic peroxides (eg, potassium persulfate, ammonium persulfate), azonitrile compounds (eg, sodium azobiscyanovalerate), and azoamidine compounds (eg, 2,2′-azobis (eg, 2,2′-azobis)). 2-methylpropionamide) hydrochloride), cyclic azoamidine compound (eg, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane hydrochloride), azoamide compound (eg, 2, 2'-azobis ｛2
-Methyl-N- [1,1′-bis (hydroxymethyl)
-2-hydroxyethyl] propionamide), an azo compound (eg, 2,2′-azobisisobutyronitrile,
2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl-2,2'-azobis (2-methylpropionate), dimethyl-2,2'-azobisisobutyrate and organic peroxide (Eg, lauryl peroxide, benzoyl peroxide, tert-butyl peroctoate). In addition, as a polymerization initiator added to the overcoat layer, it is preferable to use a compound that generates a gas (eg, nitrogen) other than oxygen in the polymerization reaction. Many of the above thermal polymerization initiators generate nitrogen in the polymerization reaction. Gases other than oxygen in the polymerization reaction (eg,
When nitrogen is generated, air (oxygen contained therein) is expelled from the layer by the generated gas, so that the polymerization reaction is further promoted. When forming a void in the low refractive index layer,
The layer contains a large amount of air (oxygen contained therein). In such a case, when a gas other than oxygen (eg, nitrogen) is generated from the polymerization initiator added to the overcoat layer, a remarkable effect of promoting the polymerization reaction can be obtained. The polymerization initiator is preferably used in an amount of 0.1 to 15 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the monomer.

[Polymerization treatment of monomer in each layer] The polymerization treatment of the monomer is carried out by irradiation with electromagnetic waves, irradiation with particle beams or heating. These processes may be combined.
When processing is combined, it may be performed simultaneously or continuously. In the case of electromagnetic wave irradiation, ultraviolet (UV)
It is preferable to use In addition, in ultraviolet irradiation, a photopolymerization initiator is used as a polymerization initiator. As the ultraviolet light source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, or a metal halide lamp can be used. High pressure mercury lamps are particularly preferred. The dose of ultraviolet rays is 100 to 2000 mJ / cm is preferably ^2, 300 to 1500 mJ / cm ² and it is more preferably 500 to 1000 mJ / c
Most preferably, m ² . In the case of particle beam irradiation, it is preferable to use an electron beam (EB). In the electron beam (EB) irradiation, the polymerization reaction can be started without using a polymerization initiator. An electron gun can be used as a source of the electron beam. The irradiation amount of the electron beam is preferably from 10 to 200 kGy, more preferably from 20 to 150 kGy, and most preferably from 50 to 100 kGy. In the case of heating, a thermal polymerization initiator is used as a polymerization initiator. The heating temperature and the heating time are determined according to the type of the thermal polymerization initiator.

[Hard Coat Layer] As shown in FIG. 1B, a hard coat layer can be provided between the transparent support and the low refractive index layer. The hard coat layer has a function of imparting scratch resistance to the transparent support. The polymer that functions as a binder for the hard coat layer (and the monomer for forming the polymer) is as described above. It is preferable to add a filler to the hard coat layer. The filler has a function of increasing the hardness of the hard coat layer and suppressing shrinkage of the layer in the polymerization reaction of the monomer. It is preferable to use inorganic fine particles or organic fine particles as the filler. Examples of the inorganic fine particles include silicon dioxide particles, titanium dioxide particles, aluminum oxide particles, tin oxide particles, calcium carbonate particles, barium sulfate particles, talc, kaolin and calcium sulfate particles. Examples of organic fine particles include methacrylic acid-methyl acrylate copolymer powder, silicon resin powder, polystyrene powder, polycarbonate powder, acrylic acid-styrene copolymer powder, benzoguanamine resin powder, melamine resin powder, polyolefin powder, polyester powder, polyamide powder, polyimide Powder and polyfluoroethylene powder. The average particle diameter of the fine particles used as a filler is preferably 0.01 to 2 μm,
More preferably, the thickness is from 02 to 0.5 μm. The hard coat layer or its coating solution further includes a colorant (pigment, dye), an antifoaming agent, a thickener, a leveling agent, a flame retardant,
An ultraviolet absorber, an antioxidant and a modifying resin may be added. The thickness of the hard coat layer is preferably 1 to 15 μm.

[High refractive index layer and medium refractive index layer] As shown in FIG. 1C, a high refractive index layer is provided between the transparent support (or hard coat layer) and the low refractive index layer. be able to. Further, as shown in FIG. 1D, a middle refractive index layer can be provided between the transparent support (or hard coat layer) and the high refractive index layer. The refractive index of the high refractive index layer is
It is preferably 1.65 to 2.40, and 1.70.
More preferably, it is from 2.20 to 2.20. The refractive index of the middle refractive index layer is adjusted to be an intermediate value between the refractive index of the transparent support and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably from 1.55 to 1.70. The thickness of the high refractive index layer and the medium refractive index layer is 5 nm to 100 nm.
μm, more preferably 10 nm to 10 μm, and most preferably 30 nm to 1 μm. The haze of the high refractive index layer and the middle refractive index layer is preferably 5% or less, more preferably 3% or less, and most preferably 1% or less. The strength of the high refractive index layer and the middle refractive index layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more at a pencil hardness of 1 kg load.

The polymer functioning as a binder for the high refractive index layer and the medium refractive index layer (and a monomer for forming the polymer) is as described above. The high refractive index layer and the medium refractive index layer preferably contain inorganic fine particles. The inorganic fine particles used for the high refractive index layer and the medium refractive index layer preferably have a refractive index of 1.80 to 2.80, and more preferably 1.90 to 2.80. The weight average diameter of the primary particles of the inorganic fine particles is 1 to 15
The thickness is preferably 0 nm, more preferably 1 to 100 nm, and most preferably 1 to 80 nm. The weight average diameter of the inorganic fine particles in the coating layer is 1
To 200 nm, preferably 5 to 150 nm.
nm, more preferably 10 to 100 nm, and most preferably 10 to 80 nm. The specific surface area of the inorganic fine particles is preferably from 10 to 400 m ² / g, and from 20 to 200 m ² / g.
m ² / g, more preferably 30 to 150
Most preferably, it is m ² / g.

The inorganic fine particles are preferably formed from a metal oxide or sulfide. Examples of metal oxides or sulfides include titanium dioxide (eg, rutile, rutile / anatase mixed crystals, anatase, amorphous structure), tin oxide, indium oxide, zinc oxide, zirconium oxide, and zinc sulfide. Titanium oxide, tin oxide and indium oxide are particularly preferred. The inorganic fine particles contain oxides or sulfides of these metals as main components and may further contain other elements. The main component means a component having the largest content (% by weight) of the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, F
e, Mn, Pb, Cd, As, Cr, Hg, Zn, A
1, Mg, Si, P and S. The inorganic fine particles may be surface-treated. The surface treatment is performed using an inorganic compound or an organic compound. Examples of the inorganic compound used for the surface treatment include alumina, silica, zirconium oxide, and iron oxide. Alumina and silica are preferred. Examples of the organic compound used for the surface treatment include a polyol, an alkanolamine, stearic acid, a silane coupling agent, and a titanate coupling agent.
Silane coupling agents are most preferred. Two or more types of surface treatments may be performed in combination. The processing may be performed by combining the above. The shape of the inorganic fine particles is
It is preferably a rice grain, a sphere, a cube, a spindle, or an irregular shape. Two or more kinds of inorganic fine particles may be used together in the high refractive index layer and the medium refractive index layer.

The proportion of the inorganic fine particles in the high refractive index layer and the medium refractive index layer is 5 to 65% by volume. The proportion of the inorganic fine particles is preferably from 10 to 60% by volume,
More preferably, it is from about 55% by volume to about 55% by volume. The inorganic fine particles are used in the form of a dispersion to form a high refractive index layer and a medium refractive index layer. It is preferable to use a liquid having a boiling point of 60 to 170 ° C. as a dispersion medium of the inorganic fine particles in the high refractive index layer and the medium refractive index layer. Examples of dispersion media include water, alcohols (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), esters (eg, methyl acetate, ethyl acetate, Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbon (eg, hexane, cyclohexane), halogenated hydrocarbon (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Hydrocarbons (eg, benzene, toluene, xylene), amides (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ethers (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohols (eg, 1-methyl Carboxymethyl -2
-Propanol). Particularly preferred are toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol. The inorganic fine particles can be dispersed in the medium using a disperser. Examples of dispersers include sand grinder mills (eg, bead mills with pins), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. Sand grinder mills and high speed impeller mills are particularly preferred. Further, a preliminary dispersion process may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader and an extruder.

[Low Refractive Index Layer] The low refractive index layer has a refractive index of
1.20 to 1.55, preferably 1.30
It is more preferably from 1.55 to 1.55. The thickness of the low refractive index layer is preferably 50 to 400 nm,
More preferably, it is 50 to 200 nm. The polymer that functions as a binder for the low refractive index layer (and a monomer for forming the polymer) is as described above. The low refractive index layer is preferably formed as a layer having a porosity of 3 to 50% by volume before forming the overcoat layer. The porosity of the low refractive index layer before the formation of the overcoat layer is more preferably 5 to 35% by volume. The voids in the low refractive index layer can be formed as microvoids between particles or within particles using 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 size of the fine particles is preferably as uniform (monodispersed) as possible. Inorganic fine particles or organic fine particles can be used for the low refractive index layer.

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,
Most preferably, it consists of a metal oxide or metal fluoride. As metal atoms, Na, K, Mg, Ca, B
a, 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 crosslinking silica molecules forming the particles. Crosslinking silica molecules reduces the volume and makes the particles porous. Microporous (porous) inorganic fine particles can be obtained by a sol-gel method (Japanese Patent Laid-Open No.
No. 112732, JP-B-57-9051) or a precipitation method (APPLIED OPTICS, 27 , p. 3356 (198
8) According to description), it can be directly formed 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 for forming 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 formed by a polymerization reaction of a monomer (for example, an emulsion polymerization method). The polymer of the organic fine particles preferably contains a fluorine atom. The proportion of fluorine atoms in the polymer is preferably from 35 to 80% by weight, more preferably from 45 to 75% by weight. Examples of the fluorinated monomer for forming the fluorinated polymer are the same as the examples of the fluorinated monomer for forming the binder polymer described above. The microvoids in the organic fine particles can be formed, for example, by crosslinking a polymer forming the particles. Crosslinking the polymer reduces its volume,
The particles become porous. In order to crosslink the polymer forming the particles, two of the monomers for forming the polymer are used.
It is preferable that 0 mol% or more be a polyfunctional monomer.
The ratio of the polyfunctional monomer is more preferably from 30 to 80 mol%, and most preferably from 35 to 50 mol%. The example of the polyfunctional monomer is the same as the example of the polyfunctional monomer for forming the binder polymer described above.

The fine particles (particularly, inorganic fine particles) are preferably subjected to a surface treatment to improve the affinity with the polymer. The surface treatment can be classified into a physical surface treatment such as a plasma discharge treatment or a corona discharge treatment, and a chemical surface treatment using a coupling agent. It is preferable to carry out only a chemical surface treatment or a combination of a physical surface treatment and a chemical surface treatment. As the coupling agent, an organoalkoxy metal compound (eg, a titanium coupling agent, a silane coupling agent) is preferably used. When the fine particles are made of silicon dioxide, surface treatment with a silane coupling agent can be particularly effectively performed. Examples of the silane coupling agent include alkyl esters of orthosilicic acid (eg, methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, i-propyl orthosilicate,
N-butyl orthosilicate, sec-butyl orthosilicate, t-butyl orthosilicate) and hydrolysates thereof. The surface treatment with the coupling agent can be carried out by adding the coupling agent to the dispersion of fine particles, and leaving the dispersion at a temperature from room temperature to 60 ° C. for several hours to 10 days. To accelerate the surface treatment reaction, an inorganic acid (eg,
Sulfuric acid, hydrochloric acid, nitric acid, chromic acid, hypochlorous acid, boric acid, orthosilicic acid, phosphoric acid, carbonic acid), organic acid (eg, acetic acid, polyacrylic acid, benzenesulfonic acid, phenol, polyglutamic acid), or these Salts (eg, metal salts, ammonium salts) may be added to the dispersion.

[0038] A shell composed of a polymer may be formed around the fine particles as a core. The polymer forming the shell is preferably a polymer having a saturated hydrocarbon as a main chain. Polymers containing a fluorine atom in the main chain or side chain are preferred, and polymers containing a fluorine atom in the side chain are more preferred. Polyacrylates or polymethacrylates are preferred, and esters of fluorine-substituted alcohols with polyacrylic or polymethacrylic acid are most preferred. The refractive index of the shell polymer decreases as the content of fluorine atoms in the polymer increases. To reduce the refractive index of the low refractive index layer, the shell polymer preferably contains 35 to 80% by weight of fluorine atoms, and more preferably 45 to 75% by weight of fluorine atoms. Examples of the fluorinated monomer for forming the fluorinated polymer are the same as the examples of the fluorinated monomer for forming the binder polymer described above. A crosslinkable functional group may be introduced into the shell polymer, and the shell polymer and the binder polymer may be chemically bonded 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 the Tg is higher than the temperature at the time of forming the low refractive index layer, the fine particles may not be fused and the low refractive index layer may not be formed as a continuous layer (as a result, the strength may be reduced). In that case, it is desirable to form the low refractive index layer as a continuous layer with a binder polymer. The core-shell fine particles preferably contain a core in an amount of 5 to 90% by volume, and 15 to 80% by volume.
More preferably, it is contained. Two or more types of core-shell fine particles may be used in combination. Also, inorganic fine particles having no shell and core-shell particles may be used in combination. The glass transition temperature (Tg) of the shell polymer is preferably higher than the Tg of the binder polymer. The temperature difference between the shell polymer Tg and the binder polymer Tg is 5 ° C.
It is preferably at least 20 ° C., more preferably at least 20 ° C.

The microvoids between particles can be formed by stacking at least two or more fine particles. When spherical particles having the same particle size (perfectly monodispersed) are closest packed, microvoids between particles having a porosity of 26% by volume are formed. When the spherical fine particles having the same particle size are simply cubically filled, microvoids between the fine particles having a porosity of 48% by volume are formed. In an actual low refractive index layer, the porosity considerably fluctuates from the above theoretical value due to the particle size distribution of the fine particles and the presence of microvoids in the particles. Increasing the porosity lowers the refractive index of the low refractive index layer. By forming microvoids by stacking fine particles and adjusting the particle size of the fine particles, the size of the microvoids between particles can be easily adjusted to an appropriate value (does not scatter light and does not cause a problem in the strength of the low refractive index layer). Can be adjusted. Further, by making the particle diameter of the fine particles uniform, an optically uniform low refractive index layer in which the size of the microvoids between particles is also uniform can be obtained. Thus, the low refractive index layer can be a microvoid-containing porous film microscopically, but can be an optically or macroscopically uniform film.

By forming microvoids, the macroscopic refractive index of the low refractive index layer becomes a value lower than the sum of the refractive indexes of the components constituting the low refractive index layer. The refractive index of a layer is the sum of the refractive indices per volume of the components of the layer. The refractive index of a component of the low refractive index layer such as fine particles or a polymer is a value larger than 1, while the refractive index of air is 1.00. Therefore, by forming microvoids,
A low refractive index layer having a very low refractive index can be obtained. The intergranular microvoids are preferably closed in the low refractive index layer by the fine particles and the polymer. When the gap is closed, the gap remains in the low refractive index layer even after the formation of the overcoat layer. The closed void also has the advantage that light is less scattered on the surface of the low-refractive-index layer compared to an opening opened on the surface of the low-refractive-index layer. A small amount of polymer (eg, polyvinyl alcohol, polyoxyethylene, polymethyl methacrylate, polymethyl acrylate, diacetyl cellulose, triacetyl cellulose,
Nitrocellulose, polyester, alkyd resin).

[Overcoat layer] The overcoat layer is formed by applying a coating solution containing a fluorine-containing compound on the low refractive index layer. The proportion of the material of the overcoat layer occupying the voids in the low refractive index layer is preferably less than 70% by volume. The ratio of the material of the overcoat layer occupying the voids in the low refractive index layer is more preferably less than 50% by volume, further preferably less than 40% by volume, and more preferably less than 30% by volume. Most preferred. Various means can be adopted to form the overcoat layer while leaving the voids in the low refractive index layer. For example, if the voids of the low refractive index layer are formed in a state where the voids are closed by the fine particles and the binder polymer, the voids of the low refractive index layer remain even if the overcoat layer is formed by coating. Further, the viscosity of the coating liquid may be increased so that the coating liquid for the overcoat layer does not enter the gaps in the low refractive index layer. However, the fluorine-containing compound in the overcoat layer as fine particles of a fluorine-containing compound having a particle size of 20 nm or more, a method of closing the opening of the void of the low refractive index layer with the fine particles, or the coating amount of the overcoat layer,
A method of adjusting the volume to be 80% by volume or less of the voids of the low refractive index layer is preferable because it is easy to carry out. The fluorine-containing compound used for the overcoat layer preferably contains fluorine atoms in the range of 35 to 80% by weight, more preferably 45 to 75% by weight. As the fluorine-containing compound, a fluorine-containing surfactant, a fluorine-containing polymer, a fluorine-containing ether or a fluorine-containing silane compound is preferably used. Fluorine-containing polymers are particularly preferred. The fluorine-containing polymer used for the overcoat layer (and the fluorine-containing monomer for forming the polymer) is as described above.

The hydrophilic portion of the fluorinated surfactant may be any of anionic, cationic, nonionic and amphoteric. In the fluorinated surfactant, part or all of the hydrogen atoms of the hydrocarbon constituting the hydrophobic portion are replaced by fluorine atoms. Fluorinated ethers are compounds generally used as lubricants. Examples of the fluorinated ether include perfluoropolyether. Examples of the fluorine-containing silane compound include silane compounds containing a perfluoroalkyl group (eg, (heptadecafluoro-1,
2,2,2-tetradecyl) triethoxysilane). When the fluorine-containing compound is used as fine particles, the fine particles preferably have a particle diameter of 20 nm or more as described above. The particle size is more preferably from 20 to 60 nm, and most preferably from 25 to 40 nm. As described above, the coating amount of the overcoat layer is 8% of the gap of the low refractive index layer before the formation of the overcoat layer.
It is preferably adjusted to 0% by volume or less. The application amount of the overcoat layer is more preferably 70% by volume or less, and most preferably 60% by volume or less of the voids of the low refractive index layer before the formation of the overcoat layer. The coating amount of the overcoat layer is generally 2 mg / m ² or more. The thickness of the overcoat layer is preferably 20 nm or less, more preferably 2 to 20 nm, further preferably 3 to 20 nm, and most preferably 5 to 10 nm.

[Anti-reflection film] The anti-reflection film may be provided with layers other than those described above. For example, an adhesive layer, a shield layer, a slip layer, and an antistatic layer may be provided on the transparent support in addition to the hard coat layer. The shield layer is provided to shield electromagnetic waves and infrared rays. The anti-reflection film may have an anti-glare function for scattering external light. The anti-glare function is obtained by forming irregularities on the surface of the antireflection film. The haze of the anti-reflective coating is
It is preferably from 3 to 30%, more preferably from 5 to 20%, and most preferably from 7 to 20%. The anti-reflection film is a liquid crystal display (LCD),
The present invention is applied to an image display device such as a plasma display panel (PDP), an electroluminescence display (ELD), and a cathode ray tube display (CRT). The transparent support side of the antireflection film is adhered to the image display surface of the image display device.

[0044]

[Example 1] (Preparation of coating solution for hard coat layer) Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.)
125g and urethane acrylate oligomer (UV-6300B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 12
5 g was dissolved in 439 g of industrial denatured ethanol.
A photopolymerization initiator (Irgacure 907,
A solution prepared by dissolving 7.5 g of Ciba Geigy Corporation and 5.0 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) in 49 g of methyl ethyl ketone was added. After stirring the mixture, the mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for the hard coat layer.

(Preparation of Titanium Dioxide Dispersion) Titanium dioxide (primary particle weight average particle diameter: 50 nm, refractive index: 2.7)
0) 30 parts by weight, 4.5 parts by weight of anionic diacrylate monomer (PM21, manufactured by Nippon Kayaku Co., Ltd.), cationic methacrylate monomer (DMAEA, Kojin Co., Ltd.)
0.3 parts by weight) and 65.2 parts by weight of methyl ethyl ketone were dispersed by a sand grinder to prepare a titanium dioxide dispersion.

(Preparation of coating solution for middle refractive index layer) 151.9 g of cyclohexanone and 37.0 g of methyl ethyl ketone
g, 0.14 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and a photosensitizer (Kayacure DE)
TX, manufactured by Nippon Kayaku Co., Ltd.). Further, 6.1 g of the above titanium dioxide dispersion and 2.4 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) were added, and the mixture was stirred at room temperature for 30 minutes. The solution was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a medium refractive index layer.

(Preparation of coating liquid for high refractive index layer) 1152.8 g of cyclohexanone and methyl ethyl ketone
To 2 g, 0.06 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and a photosensitizer (Kayacure D)
0.02 g of ETX, manufactured by Nippon Kayaku Co., Ltd.) was dissolved. Further, 13.13 g of the above titanium dioxide dispersion and a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA,
After adding 0.76 g of Nippon Kayaku Co., Ltd. and stirring at room temperature for 30 minutes, the mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a high refractive index layer.

(Preparation of coating liquid for low refractive index layer) A silane coupling agent (KBM-503, Shin-Etsu) was added to 200 g of a methanol dispersion of silica fine particles having an average particle diameter of 15 nm (methanol silica sol, manufactured by Nissan Chemical Industries, Ltd.). 3 g of 1N hydrochloric acid and 2 g of 1N hydrochloric acid were added, and the mixture was stirred at room temperature for 5 hours and then left for 3 days to prepare a silane-coupled silica fine particle dispersion. Dispersion 3 above
To 5.04 g, 58.35 g of isopropyl alcohol and 39.34 g of diacetone alcohol were added. Photopolymerization initiator (Irgacure 907, Ciba-Geigy)
1.02 g and 0.51 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) are dissolved in 772.85 g of isopropyl alcohol, and a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.)
25.6 g was added and dissolved. The resulting solution 67.23
g was added to a mixture of the above dispersion, isopropyl alcohol and diacetone alcohol. The mixture was filtered at room temperature for 20 minutes and filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a low refractive index layer.

(Preparation of Coating Solution for Overcoat Layer) Perfluorodecyltrimethoxysilane (non-crosslinkable) was dissolved in a fluorinated solvent (Fluorinert FC-77, manufactured by 3M) to prepare a 1% by weight solution. . This solution was used as a coating solution for the overcoat layer.

(Preparation of Antireflection Film) A gelatin undercoat layer was provided on a triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm. The coating solution for a hard coat layer was applied on a gelatin undercoat layer using a bar coater, and dried at 120 ° C. to form a hard coat layer. The hard coat layer was cured by irradiation with ultraviolet rays. The thickness of the hard coat layer after curing was 7.5 μm. The coating liquid for a medium refractive index layer was applied on the hard coat layer using a bar coater, and dried at 120 ° C. to form a medium refractive index layer. The medium refractive index layer was cured by irradiating ultraviolet rays. The cured medium refractive index layer has a refractive index of 1.72 and a thickness of 0.081 μm.
Met. The coating solution for a high refractive index layer was applied on the middle refractive index layer using a bar coater, and dried at 120 ° C. to form a high refractive index layer. The high refractive index layer was cured by irradiating ultraviolet rays. The cured high refractive index layer has a refractive index of 1.92 and a thickness of 0.053 μm.
Met. The coating liquid for a low refractive index layer was applied on the high refractive index layer using a bar coater, and dried at 120 ° C. to form a low refractive index layer. The low refractive index layer was cured by irradiation with ultraviolet rays. The cured low refractive index layer has a refractive index of 1.40 and a thickness of 0.072 μm.
Met. The coating solution for the overcoat layer was applied on the low refractive index layer using a # 3 wire bar, and dried at 100 ° C. for 5 minutes to form an overcoat layer. 10 Immediately using a 160 W / cm air-cooled metal halide mercury lamp, illuminance 400 mW / cm ² , irradiation amount 600 mJ
UV rays were applied at a rate of / cm ² to form an antireflection film.

(Evaluation of antireflection film) The following items were evaluated for the obtained antireflection film. The results are shown in Table 1. (1) Average reflectance 380-7 using a spectrophotometer (manufactured by JASCO Corporation)
In the wavelength region of 80 nm, the spectral reflectance at an incident angle of 5 ° was measured. Since the antireflection performance is better as the reflectance is smaller in a wide wavelength range, the measurement results show that
The average reflectance at 50 to 650 nm was determined.

(2) Surface Contact Angle After the antireflection film was conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%, the contact angle with water was measured. (3) Fingerprint Adhesion A fingerprint was attached to the surface of the antireflection film, and the state when the fingerprint was wiped off with a cleaning cloth was observed. A: The fingerprint was completely wiped off B: A part of the fingerprint remained without being wiped C: Most of the fingerprint remained without being wiped

(4) Scratch Resistance After the antireflection film was conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%, a JIS-K-5400 was used with a test pencil specified by JIS-S-6006. According to the pencil hardness evaluation method specified by, a hardness at which no flaw was observed under a load of 1 kg was measured. (5) Dynamic friction coefficient After the antireflection film was conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%, a dynamic friction meter (HEIDON-14) was used.
And a stainless steel hard sphere with a diameter of 5 mm and a load of 100
g at a speed of 60 cm / min.

Example 2 1% by weight of a thermally crosslinkable fluoropolymer (JN-7214, manufactured by Nippon Synthetic Rubber Co., Ltd.)
0.02% by weight of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and a photosensitizer (Kayacure DE)
A methyl isobutyl ketone solution containing 0.01% by weight (TX, manufactured by Nippon Kayaku Co., Ltd.) was prepared. An antireflection film was prepared in the same manner as in Example 1, except that the obtained solution was used as a coating solution for an overcoat layer. The obtained antireflection film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 3 1% by weight of a light (ultraviolet) crosslinkable fluoropolymer (TM-011, manufactured by Nippon Synthetic Rubber Co., Ltd.) and 2,2′-azobis (2,4-dimethylvaleronitrile) 0 A methyl isobutyl ketone solution containing 0.05% by weight was prepared. An antireflection film was prepared in the same manner as in Example 1, except that the obtained solution was used as a coating solution for an overcoat layer. The obtained antireflection film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 An antireflection film was prepared in the same manner as in Example 1 except that the additional polymerization treatment 10 was not performed. The obtained antireflection film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 An antireflection film was formed in the same manner as in Example 2 except that the additional polymerization treatment 10 was not performed. The obtained antireflection film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3] 12 w
/ Cm using a high pressure mercury lamp for 1 minute, except that no additional polymerization treatment was performed after the treatment.
An anti-reflection film was formed in the same manner as in Example 1. The obtained antireflection film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0059]

[Table 1] Table 1 反射 Reflection over Additional polymerization treatment Average surface Fingerprint Scratch resistance Dynamic anti-friction film Coating layer 10 Timing Reflectance Contact angle Adhesion coefficient ─────────────────────────────── ───── Real 1 after non-crosslinkability 0.51 110 ゜ A2H 0.24 Real 2 After photocrosslinkability 0.65 104 ゜ A3H 0.13 Real 3 After thermal crosslinkability 0.61 103 {A 3H 0.19 ratio 1 non-crosslinking property not performed 0.51 109} AH 0.24 ratio 2 photocrosslinking property not performed 0.65 107 {BH 0.18 ratio 3 non-crosslinking property Between 0.51 98 ゜ B HB 0.21────────────────────────────────────

Example 4 Instead of the additional polymerization treatment 10,
An antireflection film was formed in the same manner as in Example 1 except that EB irradiation of 80 kGy was performed. The obtained antireflection film exhibited the same performance as the antireflection film prepared in Example 1.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a main layer configuration of an antireflection film.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transparent support 2 hard coat layer 3 medium refractive index layer 4 high refractive index layer 5 low refractive index layer 6 overcoat layer

Continued on the front page F term (reference) 2K009 AA03 AA15 BB28 CC22 DD02 4F100 AA20B AA21B AA21D AA21E AJ06A AK01B AK17C AK25A AK25B AK25D AK25E AK51A AL05A AL05D AL05E AR10 BA01 BA03 BA01 BA01 BA00 EJ541 EJ542 EJ612 EJ651 EJ862 GB41 JL08A JL08D JL08E JN01A JN06 JN18B JN18D JN18E

Claims (7)

[Claims] 1. A step of providing a low refractive index layer forming material layer containing a monomer on a transparent support, a step of forming an overcoat layer containing a fluorine-containing compound on the low refractive index layer forming material layer, and By performing the step of polymerizing the monomer of the low refractive index layer forming material layer in this order, the transparent support, the low refractive index layer containing the polymer formed by polymerization of the monomer, and the overcoat layer containing the fluorine-containing compound A method for producing an antireflection film having: 2. A step of forming a high refractive index layer on a transparent support and providing a low refractive index layer forming material layer on the high refractive index layer before the step of providing the low refractive index layer forming material layer. A method for producing the antireflection film according to claim 1. In the step of providing a low refractive index layer forming material layer, fine particles are further added to the low refractive index layer forming material layer,
The method for producing an antireflection film according to claim 1, wherein a void is formed between or within the fine particles. 4. The method according to claim 1, wherein a step of partially polymerizing the monomer of the low refractive index layer forming material layer is performed between the step of providing the low refractive index layer forming material layer and the step of forming the overcoat layer. A method for producing an antireflection film according to the above. 5. The step of forming an overcoat layer further comprises adding a polymerization initiator to the overcoat layer, and in the step of polymerizing monomers of the low refractive index layer forming material layer, the polymerization initiator generates a gas other than oxygen. A method for producing the antireflection film according to claim 1. 6. In the step of forming an overcoat layer, a fluorine-containing monomer is used as a fluorine-containing compound,
The method for producing an antireflection film according to claim 1, wherein the step of polymerizing the monomer of the low refractive index layer forming material layer also forms a fluorine-containing polymer by polymerizing a fluorine-containing monomer. 7. The method for producing an antireflection film according to claim 1, wherein a step of polymerizing the monomer of the low refractive index layer forming material layer by irradiation with an electromagnetic wave or a particle beam is performed.