JP2006284761A - Antireflection coating, antireflection film and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating type antireflection coating suited for mass-production, to provide an antireflection coating which has a low reflectance and is excellent in scratch resistance, to provide an antireflection film provided with the antireflection coating on a transparent substrate and to provide an image display device the surface of which is excellent in scratch resistance and capable of preventing reflection on the surface. <P>SOLUTION: The antireflection coating has a low-refractive index layer made of a cured coating of copolymer (A) which comprises a main chain consisting of only carbon atoms and side chains of (meth)acryloil group, and fluorine-containing multifunction monomer (B). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an antireflection film having a high refractive index layer and a low refractive index layer, and an image display device using the same.

  Anti-reflection films and anti-reflection films are generally used for display devices such as cathode ray tube display (CRT), plasma display (PDP), electroluminescence display (ELD) and liquid crystal display (LCD) to reduce contrast due to reflection of external light. In order to prevent reflection of images and images, it is arranged on the outermost surface of the display in order to reduce reflectivity using the principle of optical interference.

  Such an antireflection film or antireflection film can be produced by forming a high refractive index layer on a support and a low refractive index layer having an appropriate thickness on the high refractive index layer. At this time, it is preferable that each layer can be formed by wet coating from the viewpoint of productivity. In order to realize a low reflectance, a material having a refractive index as low as possible is desired for the low refractive index layer. Further, since the antireflection film and the antireflection film are used on the outermost surface of the display, high scratch resistance is required. In order to lower the refractive index of the material, there are means of (1) introducing fluorine atoms, (2) lowering the density (introducing voids), but in any case, there is a tendency that the film strength is impaired and the scratch resistance is lowered. Therefore, it was a difficult task to achieve both low refractive index and high scratch resistance.

Various means are known as means for curing a fluorine-containing polymer having a low refractive index. For example, as described in Patent Documents 1 to 7, it is generally performed to cure a polymer having a hydroxyl group or the like with various curing agents. I have been. However, curing agents and fluorine-containing polymers often have problems in terms of compatibility, and improvements have been desired in terms of transparency and film hardness. To solve this problem, Patent Document 8 discloses a technique in which a melamine-based curing agent and a hydroxyl group-containing low refractive index polymer are preliminarily heated and partially condensed, and an effect is recognized to some extent to increase the transparency of the film. It is hard to say that the level is sufficient. Patent Document 9 discloses a fluorine-containing polymer having a self-crosslinking (meth) acryloyl group in the side chain. However, further improvement has been desired from the viewpoint of achieving both low refractive index and scratch resistance. .
JP 57-34107 A Japanese Patent Laid-Open No. 61-258852 JP-A 61-275311 JP-A-62-185740 JP 62-292848 A JP-A-8-92323 JP-A-12-17028 Japanese Patent Laid-Open No. 10-25388 JP 2004-45462 A

  An object of the present invention is to first provide a coating-type antireflection film suitable for mass production, and secondly to provide an antireflection film having low reflectivity and excellent scratch resistance. Third, to provide an antireflection film or an antireflection film provided with the antireflection film on a transparent support, and fourth, to provide an image display device having excellent surface scratch resistance and reflection prevention. There is.

  As a result of diligent study, the inventors of the present invention have high transparency by using a polymer having a (meth) acryloyl group that is a self-crosslinking reactive group in the side chain and a fluorine-containing polyfunctional monomer as a curing agent, And it discovered that the film | membrane which can make hardness and refractive index compatible with a high level can be formed, and came to make this invention.

That is, the present invention
1) (A) a copolymer in which the main chain is composed of only carbon atoms and includes a fluorine-containing vinyl component and a component having a (meth) acryloyl group in the side chain, and (B) a fluorine-containing poly An antireflection film characterized by having a low refractive index layer comprising a cured film with a functional monomer;
2) The antireflection film as described in 1) above, wherein the copolymer (A) and the fluorine-containing polyfunctional monomer (B) are represented by the following general formulas 1 and 2, respectively.

In General Formula 1, L ₁ represents a linking group having 1 to 10 carbon atoms, and m represents 0 or 1. X represents a hydrogen atom or a methyl group. M represents a polymerized unit of an arbitrary vinyl monomer, and may be composed of a single component or a plurality of components. x, y1, y2, and z represent mol% of each constituent component, and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y1 + y2 ≦ 70, 0 ≦ y2 ≦ 6, and 0 ≦ z ≦ 65. )

In General Formula 2, Rf represents a chain-like or cyclic q-valent fluorocarbon group containing at least a carbon atom and a fluorine atom, and may contain an oxygen atom and / or a hydrogen atom, and L ₂ has 1 carbon atom. Represents a divalent group of 10 to 10, Y represents a polymerizable group, and q represents an integer of 3 or more.
3) In the copolymer represented by the above general formula 1, L ₁ is — (CH ₂ ) _n —O— (n represents an integer of 2 to 10). The antireflection film as described,
4) The antireflection film according to 2) or 3) above, wherein the fluorine-containing polyfunctional monomer (B) represented by the general formula 2 is represented by the following general formula 3:

In general formula 3, Rf, X, and q are as defined above.
5) The fluorine-containing polyfunctional monomer represented by the above general formula 2 or 3, wherein Rf is a chain-like or cyclic q-valent perfluorocarbon group which may contain an oxygen atom. ) To 4) antireflection film,
6) The antireflection film according to any one of 2) to 5) above, wherein the copolymer (A) satisfies 40 ≦ x ≦ 60, 30 ≦ y1 ≦ 60, and z = 0.
7) The components derived from the copolymer (A) and the fluorine-containing polyfunctional monomer (B) occupy 90% by mass or more of the solid content of the low refractive index layer, as described in 1) to 6) above Antireflection film,
8) The antireflection film as described in any one of 1) to 8) above, wherein the low refractive index layer is provided on a high refractive index layer containing inorganic fine particles and a polyfunctional (meth) acrylate resin.
9) An antireflection film characterized in that the antireflection film described in 1) to 8) above is provided on a transparent support, and 10) an antireflection film as described in 9) above is disposed. An image display device is provided.

  The antireflection film or film of the present invention has high antireflection performance and excellent scratch resistance. Further, the antireflection film or film of the present invention and the image display device provided with the film have excellent properties such that reflection of external light is sufficiently prevented and scratch resistance is also high.

  A preferred embodiment of the antireflection film or film of the present invention may be a single layer structure composed of only a low refractive index layer, or may be a multilayer structure laminated with a medium / high / low refractive index layer, a hard coat layer or the like. Good. A multilayer structure is preferable, and a structure in which three or more layers of middle, high, and low refractive index layers are stacked is particularly preferable. This antireflection film may be formed and disposed directly (in situ) on an image display device or the like, but it is preferable to form the antireflection film in advance and then dispose it on the image display device.

[Typical layer structure of antireflection film]
A typical layer structure of the antireflection film of the present invention will be described below with reference to FIG.
FIG. 1 is a cross-sectional view showing various layer configurations of the antireflection film. The embodiment shown in FIG. 1A has a layer structure in the order of a transparent support 4, a hard coat layer 3, a high refractive index layer 2, and a low refractive index layer 1. As shown in (a), in the antireflection film having the high refractive index layer 2 and the low refractive index layer 1, as described in JP-A-59-50401, the high refractive index layer has the following formula ( I) and the low refractive index layer preferably satisfy the following formula (II).

Where m is a positive integer (generally 1, 2 or 3), n ₁ is the refractive index of the high refractive index layer, and d ₁ is the layer thickness (nm) of the high refractive index layer.

In the formula, n is a positive odd number (generally 1), n ₂ is the refractive index of the low refractive index layer, and d ₂ is the layer thickness (nm) of the low refractive index layer.
The refractive index n ₁ of the high refractive index layer is generally at least 0.05 higher than that of the transparent support, and the refractive index n ₂ of the low refractive index layer is preferably at least 0.1 lower than the refractive index of the high refractive index layer. And at least 0.05 lower than the transparent support. Furthermore, the refractive index n ₁ of the high refractive index layer is preferably in the range of 1.57 to 2.40.

  The embodiment shown in FIG. 1B has a layer structure in the order of a transparent support 4, a hard coat layer 3, a medium refractive index layer 5, a high refractive index layer 2, and a low refractive index layer 1. As shown in (b), the antireflective film having the medium refractive index layer 5, the high refractive index layer 2 and the low refractive index layer 1 has a medium refractive index as described in JP-A-59-50401. It is preferable that the refractive index layer satisfies the following formula (III), the high refractive index layer satisfies the following formula (IV), and the low refractive index layer satisfies the following formula (V).

In the formula, h is a positive integer (generally 1, 2 or 3), n ₃ is the refractive index of the medium refractive index layer, and d ₃ is the layer thickness (nm) of the medium refractive index layer.

In the formula, j is a positive integer (generally 1, 2 or 3), n ₄ is the refractive index of the high refractive index layer, and d ₄ is the layer thickness (nm) of the high refractive index layer.

Where k is a positive odd number (generally 1), n ₅ is the refractive index of the low refractive index layer, and d ₅ is the layer thickness (nm) of the low refractive index layer.

The refractive index n ₃ of the medium refractive index layer is generally in the range of 1.5 to 1.7, and the refractive index n ₄ of the high refractive index layer is generally in the range of 1.7 to 2.2.

Moreover, (lambda) in Formula (I)-(V) is a wavelength of visible light, and is a value of the range of 380-680 nm. The high refractive index (n ₃ ), medium refractive index (n ₄ ), and low refractive index (n ₅ ) defined here mean the relative refractive index between layers, and n ₃ > n ₄ > n _5. Are in a relationship. Specifically, the medium refractive index layer is produced by a method such as changing the content of the high refractive index inorganic fine particles added to the high refractive index layer.
The low refractive index layer improved according to the present invention is used for the antireflection film having the above layer structure.

[Low refractive index layer]
The low refractive index layer is disposed on the upper layer of the high refractive index layer as shown in FIGS. The upper side of the low refractive index layer is the surface of the antireflection film.

  In the present invention, the low refractive index layer is a copolymer (hereinafter also referred to as component A) comprising a fluorine-containing vinyl structural unit and a structural unit having a (meth) acryloyl group in the side chain. And a cured film of fluorine-containing polyfunctional (meth) acrylate (hereinafter also referred to as component B). The component derived from the A component + B component preferably occupies 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. Moreover, the weight ratio of A component and B component is 1: 99-99: 1, Preferably it is 50: 50-99: 1, More preferably, it is 70: 30-95: 5.

The refractive index of the low refractive index layer is preferably 1.20 to 1.49, more preferably 1.20 to 1.45, and particularly preferably 1.20 to 1.44.
The thickness of the low refractive index layer is preferably 50 to 400 nm, and more preferably 50 to 200 nm. The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less. The specific strength of the low refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test under a 1 kg load.

The copolymer (component A) used in the low refractive index layer of the present invention is described below.
In the fluorine-containing vinyl component, fluorine may be bonded to the main chain of the copolymer or may be bonded to the side chain, but preferably it is fluorine in the main chain.
Specific fluorine-containing vinyl monomers that give a fluorine-containing vinyl structural unit by polymerization include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, etc.), (meth) acrylic acid Or partially fluorinated alkyl ester derivatives (for example, Biscoat 6FM (trade name, manufactured by Osaka Organic Chemicals) and M-2020 (trade name, manufactured by Daikin)), fully or partially fluorinated vinyl ethers, and the like. Perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of refractive index, solubility, transparency, availability, and the like. Increasing the composition ratio of these fluorine-containing vinyl monomers can lower the refractive index but lowers the film strength. In the present invention, it is preferable to introduce the fluorine-containing vinyl monomer so that the fluorine content of the copolymer is 20 to 60% by mass, more preferably 25 to 55% by mass, and particularly preferably 30 to 50% by mass. This is a case of mass%.

  The copolymer (component A) of the present invention has a polymer unit having a (meth) acryloyl group in the side chain as an essential component. The method for introducing the (meth) acryloyl group into the copolymer is not particularly limited. For example, (1) after synthesizing a polymer having a nucleophilic group such as a hydroxyl group or an amino group, (meth) acrylic acid is used. A method in which chloride, (meth) acrylic anhydride, (meth) acrylic acid and methanesulfonic acid mixed acid anhydride, etc. are allowed to act; (2) the polymer having the nucleophilic group in the presence of a catalyst such as sulfuric acid ( (3) a method of allowing a methacrylic acid to act, (3) a method of causing a compound having both an isocyanate group such as methacryloyloxypropyl isocyanate and a (meth) acryloyl group to act on the polymer having the nucleophilic group, and (4) a polymer having an epoxy group. (5) A method in which (meth) acrylic acid is allowed to act after the synthesis of (5) a polymer having a carboxyl group, Method of reacting a compound having both a carboxy group and a (meth) acryloyl group, and a method of performing dehydrochlorination after obtained by polymerizing a vinyl monomer having a (6) 3-chloropropionic acid ester moiety. Among these, in the present invention, it is particularly preferable to introduce a (meth) acryloyl group by the method (1) or (2) for a polymer containing a hydroxyl group.

  If the composition ratio of these (meth) acryloyl group-containing polymerization units is increased, the film strength is improved, but the refractive index is also increased. Generally, the (meth) acryloyl group-containing component preferably occupies 5 to 90% by mass in the copolymer (component A), depending on the type of the fluorine-containing vinyl monomer polymerization unit, and 30 to 70% by mass. More preferably, it occupies 40 to 60% by mass.

  In the copolymer useful for the present invention, in addition to the above-mentioned fluorine-containing vinyl monomer polymerization unit and the constituent component having a (meth) acryloyl group in the side chain, adhesion to the substrate, Tg of the polymer (contributes to film hardness), From various viewpoints such as solubility in a solvent, transparency, slipperiness, dust resistance and antifouling properties, other vinyl monomers can be appropriately copolymerized. A plurality of these vinyl monomers may be combined depending on the purpose, and are preferably introduced in the range of 0 to 65 mol% in the copolymer in total, and more preferably in the range of 0 to 40 mol%. The range of 0 to 30 mol% is particularly preferable.

  The vinyl monomer unit that can be used in combination is not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, etc.), styrene derivatives (styrene, p-hydroxymethyl styrene) , P-methoxystyrene, etc.), vinyl ethers (methyl vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, etc.), vinyl esters (acetic acid) Nyl, vinyl propionate, vinyl cinnamate, etc.), unsaturated carboxylic acids (acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, etc.), acrylamides (N, N-dimethylacrylamide, N-tertbutylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamides (N, N-dimethylmethacrylamide), acrylonitrile and the like.

A preferred form of the copolymer used in the present invention is that of the general formula 1. In the general formula 1, there are no particular restrictions on the polymerization forms of the four constituent components, and any form such as a random polymer, a block polymer in which the same kind of blocks are bonded, or a graft polymer may be used. In General Formula 1, L ₁ represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, May have a branched structure, may have a ring structure, and may have a heteroatom selected from O, N, and S.
Preferred examples include * — (CH ₂ ) _n —O — ** (n = 1 to 10, preferably n = 1), * — (CH ₂ ) ₂ —NH — **, * — (CH ₂ ). ₂ —O— (CH ₂ ) ₂ —O — **, —CONH— (CH ₂ ) ₃ —O — **, * —CH ₂ CH (OH) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** (* represents a connecting site on the polymer main chain side, and ** represents a connecting site on the (meth) acryloyl group side). m represents 0 or 1;

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

  In General Formula 1, M represents a polymerization unit of any vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with hexafluoropropylene. It can be selected from various viewpoints such as solvent solubility, transparency, slipperiness, dustproof / antifouling properties, etc., and is composed of single or multiple vinyl monomers depending on the purpose. May be.

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

  x, y1, y2, and z represent mol% of each constituent component, and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y1 + y2 ≦ 70, 0 ≦ y2 ≦ 65, and 0 ≦ z ≦ 65. Preferably, 35 ≦ x ≦ 55, 30 ≦ y1 + y2 ≦ 60, 0 ≦ y2 ≦ 30, 0 ≦ z ≦ 20, and particularly preferably 40 ≦ x ≦ 55, 40 ≦ y1 + y2 ≦ 55, 0 ≦ y2 ≦. 10, 0 ≦ z ≦ 10.

  The copolymer represented by the general formula 1 can be synthesized, for example, by introducing a (meth) acryloyl group into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any of the methods described above. .

  Preferred examples of the copolymer (component A) useful in the present invention are shown below, but the present invention is not limited thereto. In the following formula, 50, x, y, a, b, c, z, z1, and z2 of three or four constituent components represent the type and ratio (mol%), and the polymerization form It does not indicate.

  The fluorine-containing copolymer is preferably used in the range of 50% to less than 100% of the total solid content of the low refractive index layer film, more preferably in the range of 70% by mass to less than 99%, and particularly preferably 80%. This is a case of not less than 95% by mass.

  The copolymer used in the present invention can be synthesized by various polymerization methods such as solution polymerization, suspension polymerization, intelligent precipitation polymerization, bulk polymerization, emulsion polymerization and the like. Alternatively, after synthesizing a precursor such as a hydroxyl group-containing polymer by these methods, it can be synthesized by introducing a (meth) acryloyl group or the like by the polymer reaction. The polymerization reaction can be performed by a known operation such as a batch system, a semi-continuous system, or a continuous system.

  The polymerization initiation method includes a method using a radical initiator, a method of irradiating light or radiation, and the like. These polymerization methods and polymerization initiation methods are, for example, the revised version of Tsuruta Junji “Polymer Synthesis Method” (published by Nikkan Kogyo Shimbun, 1971), Takatsu Otsu, Masato Kinoshita, “Experimental Methods for Polymer Synthesis” It is described in pp. 47-154 published in 1972.

  Among the above polymerization methods, a solution polymerization method using a radical initiator is particularly preferable. Solvents used in the solution polymerization method include, for example, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, benzene, toluene, acetonitrile, A single organic solvent such as methylene chloride, chloroform, dichloroethane, methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol, or a mixture of two or more thereof may be used, or a mixed solvent with water may be used.

  The polymerization temperature needs to be set in relation to the molecular weight of the polymer to be produced, the type of initiator, etc., and can be from 0 ° C. or lower to 100 ° C. or higher, but it is preferable to carry out the polymerization in the range of 50 to 100 ° C.

Although the reaction pressure can be selected as appropriate, it is usually 1-100 kg / cm ² , and particularly preferably about 1-30 kg / cm ² . The reaction time is about 5 to 30 hours.

  As the reprecipitation solvent for the obtained polymer, isopropanol, hexane, methanol and the like are preferable.

  The fluorine-containing polyfunctional monomer (component B) used for the low refractive index layer of the present invention is described below. In General Formula 2, Rf represents a “fluorine-containing core portion” and represents a chain or cyclic fluorocarbon group that contains at least a carbon atom and a fluorine atom, and may contain an oxygen atom and / or a hydrogen atom. Rf is preferably a “perfluorocore part” which may contain an oxygen atom but does not contain a hydrogen atom. Preferred Rf has 3 to 50 carbon atoms, preferably 6 to 40, more preferably 9 ~ 30.

L ₂ represents a divalent group having 1 to 10 carbon atoms, more preferably a divalent group having 1 to 6 carbon atoms, and particularly preferably a divalent group having 1 to 4 carbon atoms. Alternatively, it may have a branched structure, may have a ring structure, or may have a heteroatom selected from O, N, and S.
Preferred examples include * —CH ₂ —O — **, * — (CH ₂ ) —O— (CH ₂ ) ₂ —O — **, * —CO ₂ — **, —CO ₂ — (CH ₂ ) ₂ -O-**, -CONH- (CH ₂ ) ₂ -O-** (* represents a Rf-side linking site, and ** represents a Y-side linking site). —CH ₂ —O — ** is particularly preferred.

Y is a radical, cation, or condensation polymerizable group, and examples thereof include a (meth) acryloyl group, an allyl group, a vinyl group, an alkoxysilyl group, an α-fluoroacryloyl group, and an epoxy group. Y is preferably a radically polymerizable (meth) acryloyl group or α-fluoroacryloyl group, more preferably a (meth) acryloyl group.
q represents an integer of 3 or more, preferably an integer of 4 or more, more preferably an integer of 5 or more. q is preferably 10 or less.
A more preferred embodiment of the fluorine-containing polyfunctional monomer represented by the general formula 2 is a fluorine-containing polyfunctional methacrylate represented by the general formula 3 (wherein Rf, X and q are as defined above).

  Preferred examples of the fluorine-containing polyfunctional monomer (component B) useful in the present invention are shown below, but the present invention is not limited thereto.

  The fluorine-containing polyfunctional monomer (component B) used in the present invention is a polyfunctional (per) fluoro product obtained by a liquid phase fluorination reaction described in US Pat. No. 5,093,432 or WO00 / 56694, or a functional group converter thereof. In contrast, various structures can be easily synthesized by introducing a polymerizable group. A general synthesis route of the fluorine-containing polyfunctional (meth) acrylate represented by the general formula 3 is shown below as a diagram, but the present invention is not limited to this.

本発明の低屈折率層形成組成物は、通常、液の形態をとり前記共重合体（A成分）と含フッ素多官能モノマー（Ｂ成分）を必須の構成成分とし、必要に応じて各種添加剤およびラジカル重合開始剤を適当な溶剤に溶解して作製される。この際、低屈折率層形成組成物中の固形分の濃度は、用途に応じて適宜選択されるが一般的には０．０１〜６０質量％程度であり、好ましくは０．５〜５０質量％、特に好ましくは１〜２０質量％程度である。

The low refractive index layer-forming composition of the present invention is usually in the form of a liquid, and the copolymer (component A) and fluorine-containing polyfunctional monomer (component B) are essential constituents, and various additions are made as necessary. It is prepared by dissolving an agent and a radical polymerization initiator in a suitable solvent. Under the present circumstances, although the density | concentration of the solid content in a low refractive index layer forming composition is suitably selected according to a use, generally it is about 0.01-60 mass%, Preferably it is 0.5-50 mass. %, Particularly preferably about 1 to 20% by mass.

  From the viewpoint of interfacial adhesion to the high refractive index layer, etc., the polyfunctional (meth) acrylate compound, polyfunctional epoxy compound, polyisocyanate compound, aminoplast, polybasic acid or anhydride thereof in the low refractive index layer forming composition A small amount of a curing agent such as silica or inorganic fine particles such as silica can also be added. In the case of adding these, it is preferably in the range of 0 to 20% by mass, more preferably in the range of 0 to 10% by mass with respect to the component (A component + B component) of the low refractive index layer film, A range of 0 to 5% by mass is particularly preferable.

  In addition, for the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipping properties, known silicone-based or fluorine-based antifouling agents, slipping agents, and the like can be appropriately added. When these additives are added, it is preferably added in the range of 0 to 20% by mass, more preferably 0 to 10% by mass with respect to the components (A component + B component) of the low refractive index layer film. It is a case where it is added in a range, particularly preferably 0 to 5% by mass.

  As a radical polymerization initiator for curing the low refractive index layer forming composition, any form of generating radicals by the action of heat or generating radicals by the action of light is possible.

As the compound that initiates radical polymerization by the action of heat, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.
Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Ammonium sulfate, potassium persulfate, etc., 2-azobis (isobutyronitrile), 2-azobis (propionitrile), 2-azobis (cyclohexanedinitrile), etc. as diazo compounds, diazoaminobenzene, p-nitrobenzenediazonium Etc.

When a compound that initiates radical polymerization by the action of light is used, the coating is cured by irradiation with active energy rays.
Examples of such radical photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds , Disulfide compounds, fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoins include benzoin benzene sulfonate, benzoin toluene sulfonate, 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 phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Sensitizing dyes can also be preferably used in combination with these photoradical polymerization initiators.

  The amount of the compound that initiates radical polymerization by the action of heat or light may be any amount that can initiate the polymerization of the carbon-carbon double bond, but generally the total amount in the low refractive index layer forming composition is not limited. 0.1-15 mass% is preferable with respect to solid content, More preferably, it is 0.5-10 mass%, Most preferably, it is a case of 2-5 mass%.

  The solvent contained in the low refractive index layer coating liquid composition is not particularly limited as long as the composition containing the fluorine-containing copolymer is uniformly dissolved or dispersed without causing precipitation. A solvent can also be used in combination. Preferred examples include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), ethers (tetrahydrofuran, 1,4-dioxane, etc.), alcohols (methanol, ethanol, isopropyl). Alcohol, butanol, ethylene glycol, etc.), aromatic hydrocarbons (toluene, xylene, etc.), water and the like.

  In addition, additives such as various silane coupling agents, surfactants, thickeners, and leveling agents may be appropriately added to the low refractive index layer forming composition as necessary.

[High / Medium Refractive Index Layer]
When the antireflection film of the present invention takes the form of a multilayer film, generally, the low refractive index layer has at least one layer having a higher refractive index than the low refractive index layer (that is, the high refractive index layer, the medium refractive index). Rate layer).

  Examples of organic materials for forming a layer having a higher refractive index than the low refractive index layer include film-forming thermoplastic resins (eg, polystyrene, polystyrene copolymer, polycarbonate, aromatic rings other than polystyrene, heterocycles, fats). Polymers having cyclic cyclic groups, or polymers having halogen groups other than fluorine); Thermal film forming compositions (eg, film compositions using melamine film, phenol film, epoxy film, etc. as a curing agent); urethane formation Modified to enable radical curing by introducing a double bond into the above-mentioned compound (polymer, etc.); and a radically polymerizable composition (eg, a combination of alicyclic or aromatic isocyanate and polyol); And a composition containing a film or a prepolymer). A material having high film-forming properties is preferred. For the layer having a higher refractive index, inorganic fine particles dispersed in an organic material can also be used. As the organic material to be used above, those having a refractive index lower than that in the case where the organic fine particles are used alone because inorganic fine particles generally have a high refractive index can be used. As such materials, in addition to the above-mentioned organic materials, acrylic copolymers, vinyl copolymers, polyesters, alkyd coatings, fibrous polymers, urethane coatings, various curing agents that cure these, and curability Examples thereof include various organic materials that are transparent and stably disperse inorganic fine particles, such as a composition having a functional group.

Further organically substituted silicon-based compounds can be included therein. These silicon compounds are compounds represented by the following general formula or hydrolysis products thereof.
_{Ra m Rb n SiZ (4-} mn)
(Here, Ra and Rb represent an alkyl group, an alkenyl group, an allyl group, or a hydrocarbon group substituted with a halogen atom, epoxy, amino, mercapto, methacryloyl or cyano, respectively, Z represents an alkoxyl group or an alkoxyalkoxyl group. And represents a hydrolyzable group selected from a halogen atom to an acyloxy group, m + n is 1 or 2, and m and n are 0, 1 or 2, respectively.

  Preferable inorganic compounds of inorganic fine particles dispersed in these include oxides of metal elements such as aluminum, titanium, zirconium and antimony. These compounds are commercially available in particulate form, ie as a colloidal dispersion in powder or water and / or other solvents. These are further mixed and dispersed in the above organic material or organosilicon compound.

  As a material for forming a layer having a higher refractive index than the above, an inorganic material (eg, alkoxides of various elements, organic acid salts, organic acid salts, which can be formed into a film and can be dispersed in a solvent or is a liquid itself). And coordination compounds (eg, chelate compounds) and inorganic polymers) bonded to a coordination compound. Suitable 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 riboxide, zirconium tetraethoxide, zirconium tetra-i-propoxide, zirconium tetra-n-propoxide, zirconium tetra- Metal alcoholate compounds such as n-butoxide, zirconium tetra-sec-butoxide and zirconium tetra-tert-butoxide; diisopropoxytitanium bis (acetylacetonate) Dibutoxytitanium bis (acetylacetonate), diethoxytitanium bis (acetylacetonate), bis (acetylacetonezirconium), aluminum acetylacetonate, aluminum di-n-butoxide monoethylacetoacetate, aluminum di-i-propoxide monomethyl Chelate compounds such as acetoacetate and tri-n-butoxide zirconium monoethyl acetoacetate; and inorganic polymers mainly composed of carbon zirconyl ammonium or zirconium. In addition to those described above, various alkyl silicates or hydrolysates thereof, particularly particulate silica, especially silica gel dispersed in a colloidal form can be used as a compound having a relatively low refractive index but can be used in combination with the above-mentioned compounds. .

  The refractive index of the high refractive index layer is generally 1.70 to 2.20. The refractive index can be obtained by measurement using an Abbe refractometer or estimation from the reflectance of light from the layer surface. The thickness of the high refractive index layer is preferably 5 nm to 10 μm, more preferably 10 nm to 1 μm, and most preferably 30 nm to 0.5 μm. The haze of the high refractive index layer is preferably 5% or less, more preferably 3% or less, and most preferably 1% or less. The specific strength of the high refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher, with a pencil hardness of 1 kg.

The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.50 to 1.70.
It is particularly preferable that inorganic fine particles and a polymer are used for the high refractive index layer, and the middle refractive index layer is formed by adjusting the refractive index to be lower than that of the high refractive index layer. The haze of the medium refractive index layer is preferably 3% or less.

[Other layers]
The antireflection film may further be provided with a hard coat layer, a moisture proof layer, an antistatic layer, an undercoat layer or a protective layer. The hard coat layer is provided for imparting scratch resistance to the transparent support. The hard coat layer also has a function of strengthening the adhesion between the transparent support and the layer thereon. The hard coat layer can be formed using an acrylic polymer, a urethane polymer, an epoxy polymer, a silicon polymer, or a silica compound. A pigment may be added to the hard coat layer. The acrylic polymer is preferably synthesized by a polymerization reaction of a polyfunctional acrylate monomer (eg, polyol acrylate, polyester acrylate, urethane acrylate, epoxy acrylate). Examples of the urethane polymer include melamine polyurethane. As the silicon-based polymer, a cohydrolyzate of a silane compound (eg, tetraalkoxysilane, alkyltrialkoxysilane) and a silane coupling agent having a reactive group (eg, epoxy, methacryl) is preferably used. Two or more kinds of polymers may be used in combination. As the silica compound, colloidal silica is preferably used. The strength of the hard coat layer is a pencil hardness with a 1 kg load, preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher. On the transparent support, in addition to the hard coat layer, an adhesive layer, a shield layer, a sliding layer and an antistatic layer may be provided. The shield layer is provided to shield electromagnetic waves and infrared rays.

[Transparent support]
In addition to the case where the antireflection film is directly provided on the CRT image display surface or the lens surface, the antireflection film may be formed on the transparent support and used as the antireflection film. As the transparent support, a plastic film is preferable to a glass plate. Examples of plastic film materials include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, nitrocellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate). , Poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, Polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, polymethylmethene Tacrylate and polyether ketone are included. Triacetyl cellulose, polycarbonate, polyethylene terephthalate and polyethylene naphthalate 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, and more preferably 1.0% or less. The refractive index of the transparent support is preferably 1.4 to 1.7. An infrared absorber or an ultraviolet absorber may be added to the transparent support. The addition amount of the infrared absorber is preferably 0.01 to 20% by mass of the transparent support, and more preferably 0.05 to 10% by mass. As a slip agent, particles of an inert inorganic compound may be added to the transparent support. Examples of the inorganic _{compound, SiO 2, TiO 2, BaSO} 4, CaCO 3, talc and kaolin. A surface treatment may be performed on the transparent support. Examples of the surface treatment include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment and ozone oxidation treatment. Glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment and flame treatment are preferred, and glow discharge treatment and ultraviolet treatment are more preferred.

[Formation of antireflection film]
When the antireflection film has a single layer or a multi-layer structure as described above, each layer is formed by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or extrinsic. It can be formed by coating by a rouge coating method (described in US Pat. No. 2,681,294). Two or more layers may be applied simultaneously. The method of simultaneous application is described in US Pat. Nos. 2,761,789, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973).

Curing of each layer of the antireflection film of the present invention is performed by the action of ionizing radiation and / or heat. The irradiation with ionizing radiation is preferably performed using a high-pressure mercury lamp. In this case, for example, it is preferable to irradiate ultraviolet rays under an oxygen concentration of 0.5% or less, more preferably an oxygen concentration of 0.3% or less, particularly preferably 0.2% or less. The irradiation energy should be the amount required for the curing reaction proceeds sufficiently, specifically, it is preferably in the range of ^{300mJ / cm 2 ~1500mJ / cm 2} , more preferably 400mJ / cm ² ~1000mJ / in the range of cm ^2, particularly preferably in the range of ^{500mJ / cm 2 ~800mJ / cm 2} .

  In the case of heating, a temperature range of about 30 to 200 ° C is preferable, more preferably 80 to 180 ° C, and particularly preferably 100 to 150 ° C. The heating time is preferably in the range of 30 seconds to 100 hours, more preferably 1 minute to 1 hour, and particularly preferably 2 minutes to 15 minutes.

  The lower the reflectance of the antireflection film or film (hereinafter sometimes simply referred to as an antireflection film), the better. Specifically, the specular average reflectance in the wavelength region of 450 to 650 nm is preferably 2% or less, more preferably 1% or less, and most preferably 0.7% or less. The haze of the antireflection film (when the antiglare function described below is absent) is preferably 3% or less, more preferably 1% or less, and most preferably 0.5% or less. The strength of the antireflection film is preferably 1 H or more, more preferably 2 H or more, and most preferably 3 H or more, with a pencil hardness of 1 kg. The antireflection film may have an antiglare function that scatters external light. The antiglare function is obtained by forming irregularities on the surface of the antireflection film. In a low refractive index layer using fine particles, irregularities can be formed on the surface of the antireflection film by the fine particles. When the anti-glare function obtained by the fine particles is insufficient, relatively small particles (particle size: 50 nm to 200 nm in small amounts (0.1 to 0.1) When the antireflection film has an antiglare function, the haze of the antireflection film is preferably 3 to 30%, more preferably 5 to 20%, and 7 to 7%. Most preferably, it is 20%.

The antireflection film is applied to an image display device such as a polarizing plate or a display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), or a cathode ray tube display device (CRT). . The antireflection film is disposed so that the high refractive index layer is on the image display surface side of the image display device. When the antireflection film is provided on the transparent support and used as an antireflection film, the transparent support side is adhered to the image display surface of the image display device.
Further, the antireflection film can be used for a case cover, an optical lens, a spectacle lens, a window shield, a light cover, and a helmet shield.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

<Synthesis example>
Synthesis of fluorine-containing polyfunctional monomer (M-6) M-6 was synthesized by the following route.

Synthesis of M-6b Perfluorohexane (175 ml) was placed in a 250 ml Teflon reaction vessel and kept at 20 ° C. A NaF pellet packed bed and a cooler maintained at −40 ° C. were installed in series at the outlet of the reaction vessel so that the liquid condensed by the cooler could be returned to the reaction vessel through the return line. After nitrogen gas was blown for 1 hour at a rate of 30 ml / min, fluorine gas diluted to 20% with nitrogen gas (hereinafter simply referred to as fluorine gas) was blown for 30 minutes at a rate of 200 ml / min. While blowing fluorine gas at the same rate, a solution of M-6a (21 g) in trichlorofluoromethane (21 ml) was added over 9 hours 30 minutes, and further, while fluorine gas was blown at the same rate, hexafluorobenzene (2.0 g ) In perfluorohexane (10 ml) was added over 1 hour 30 minutes. Fluorine gas was blown in at a rate of 100 ml / min for 1 hour. The solvent was distilled off at normal pressure and then purified under reduced pressure to obtain M-6b [23.9 g, b. p. = 100 ° C. (20 mmHg)].

Synthesis of M-6c Methanol (96 ml) was added dropwise at 0-5 ° C. over 50 minutes to a perfluorohexane (100 ml) solution of M-6b (23.9 g) obtained above in a nitrogen stream. After stirring at 20-25 ° C. for 20 hours, nitrogen gas was blown into the reaction solution for 1 hour. The solvent was distilled off under reduced pressure, isopropanol was added to the residue, and the precipitated crystals were separated by filtration to obtain M-6c (2.93 g). Further, the filtrate was concentrated under reduced pressure, and the residue was purified by column chromatography (developing solvent: ethyl acetate / hexane = 1/5) to obtain M-6c (7.22 g).

Synthesis of M-6d M-6c (7.22 g) was added to a dispersion of lithium aluminum hydride (0.78 g) in tetrahydrofuran (70 ml) at 0-5 ° C. over 15 minutes, and then stirred for 5 hours under reflux. . The reaction solution was cooled to room temperature, an ethanol / water (90/10) mixture (80 ml) was added dropwise over 20 minutes, and the mixture was stirred for 2 hours, and then a white solid was filtered. The filtrate was concentrated under reduced pressure, dichloromethane was added to the residue, and the precipitated crystals were filtered and dried to obtain M-6d (2.3 g).

Synthesis of M-6 To a mixture of M-6d (1.0 g) and potassium carbonate (1.7 g) in ethyl acetate (20 ml) was added dropwise methacrylic acid chloride (1.1 g) at 0 to 5 ° C., and then room temperature. For 20 hours. Ethyl acetate and water were added to the reaction solution, and the organic layer was washed with water and dried over anhydrous magnesium sulfate. After filtration, the solvent was distilled off under reduced pressure, and the residue was purified by column chromatography (developing solvent: ethyl acetate / hexane = 1/5) to obtain M-6 (0.6 g). The obtained M-6 was a mixture of two isomers (M-6e / M-6f≈5).
¹ H NMR (300 MHz, solvent: CDCl ₃ , standard: TMS) M-6a: 6.21 (s, 3H), 5.69 (s, 3H), 4.88 (d, J = 18.9, 6H), 1.97 (s, 9H) , M-6b: 6.22 (s, 3H), 5.68 (s, 3H), 4.86 (d, J = 12.9, 3H), 1.98 (s, 9H)
¹⁹ F-NMR (282.40 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) M-6e: −113.8 (t, J = 455.4, 1F), −122.2 (t, J = 350.3 Hz, 1F), −185.1 ( bs, 1F), M-6f: −113.8 (t, J = 303.6, 1F), −122.3 (t, J = 303.6 Hz, 1F), −187.1 (s, 1F)

Other fluorine-containing polyfunctional monomers of the present invention can be synthesized in the same manner.
The fluorine-containing copolymer (component A) of the present invention can be synthesized by the method described in JP-A-2004-45462.

[Example 1] Antireflection film (production of a single layer)
The copolymer of the present invention (component A) and fluorine-containing polyfunctional monomer (component B) or DPHA (dipentaerythritol hexaacrylate; manufactured by Nippon Kayaku Co., Ltd.) are mixed at a weight ratio shown in Table 1, It melt | dissolved in methyl isobutyl ketone so that it might become a density | concentration of 30 mass%, and produced the liquid which added 5 mass% of photoradical generator Irgacure 907 (brand name; Ciba Geigy company make) with respect to solid content. After coating and drying the film-forming composition on a glass substrate, a cured film having a thickness of about 20 μm is formed by irradiating ultraviolet rays with an energy of 750 mJ / cm ² with an oxygen concentration of 0.1% and reflecting. It was set as the prevention film sample (this invention -1-6 and comparative examples -1-4).

  The film hardness of these antireflection film samples was measured using a micro hardness meter (manufactured by Fisher Instruments: Fisherscope H100VP-HCU (trade name)). At this time, a square pyramid indenter (tip-to-face angle: 136 °) made of diamond was used, and the indentation depth under an appropriate test load was measured in a range where the indentation depth did not exceed 1 μm. The universal hardness value is expressed as the test load divided by the surface area calculated from the geometry of the indentation produced by the test load. Table 1 shows the universal hardness value (HU) of the film of each sample and the refractive index of the cured film (measured with an Abbe refractometer (manufactured by Atago Co., Ltd.) at a temperature of 20 ° C.).

  The antireflection film samples (present inventions 1 to 7) formed by using the copolymer of the present invention (component A) and the fluorine-containing polyfunctional monomer (component B) together are copolymer (component A) single samples (comparison) It turns out that it is excellent in the viewpoint of coexistence of high hardness and low refractive index compared with the combined sample (Comparative Example-4) of Example 1) or a copolymer (component A) and DPHA.

[Example 2] Preparation of antireflection film (multilayer) The components shown in Table 2 below were mixed and dissolved in methyl isobutyl ketone, and then filtered through a polypropylene filter having a pore size of 1 µm to obtain a coating solution for a low refractive index layer. Was prepared.
In the table, DPHA (trade name) represents dipentaerythritol hexaacrylate manufactured by Nippon Kayaku Co., Ltd., and IRG907 represents Irgacure 907 (trade name) manufactured by Ciba Geigy Co., Ltd.

Preparation of coating solution for first layer (hard coat layer) 125 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA (trade name), manufactured by Nippon Kayaku Co., Ltd.) and urethane acrylate oligomer (UV-6300B) 125 g (trade name) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. was dissolved in 439 g of industrially modified ethanol. In the obtained solution, 7.5 g of photopolymerization initiator (Irgacure 907 (trade name), manufactured by Ciba-Geigy) and photosensitizer (Kayacure-DETX (trade name), manufactured by Nippon Kayaku Co., Ltd.) 5 A solution of 0.0 g in 49 g of methyl ethyl ketone was added. The mixture was stirred and then filtered through a 1 micron mesh filter to prepare a hard coat layer coating solution.

Preparation of titanium dioxide dispersion Titanium dioxide fine particles having a core / shell structure (TTO-55B (trade name), manufactured by Ishihara Sangyo Co., Ltd.), anionic diacrylate monomer (PM21 (trade name), Nippon Kayaku ( Co., Ltd.) 4.5 parts by weight, cationic methacrylate monomer (DMAEA (trade name), manufactured by Kojin Co., Ltd.) 0.3 parts by weight and methyl ethyl ketone 65.2 parts by weight are dispersed with a sand grinder, and titanium dioxide. A dispersion was prepared.

Preparation of Second Layer (Medium Refractive Index Layer) Coating Solution To 151.9 g of cyclohexanone and 37.0 g of methyl ethyl ketone, 0.14 g of a photopolymerization initiator (Irgacure 907 (trade name), manufactured by Ciba-Geigy) and a photosensitizer 0.04 g (Kayacure-DETX (trade name), manufactured by Nippon Kayaku Co., Ltd.) was dissolved. Further, 6.1 g of the above titanium dioxide dispersion and 2.4 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) were added and stirred for 30 minutes at room temperature. A medium refractive index layer coating solution was prepared by filtration through a mesh filter.

Preparation of Third Layer (High Refractive Index Layer) Coating Solution 152.8 g of cyclohexanone and 37.2 g of methyl ethyl ketone, 0.06 g of a photopolymerization initiator (Irgacure 907 (trade name), manufactured by Ciba-Geigy) and a photosensitizer 0.02 g (Kayacure-DETX (trade name), manufactured by Nippon Kayaku Co., Ltd.) was dissolved. Further, 13.13 g of the titanium dioxide dispersion and 0.76 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA (trade name), manufactured by Nippon Kayaku Co., Ltd.) were added and stirred at room temperature for 30 minutes. Then, the mixture was filtered with a 1 micron mesh filter to prepare a coating solution for a high refractive index layer.

Preparation of antireflection film The antireflection film shown in FIG. 1B was prepared as follows.
A gelatin subbing layer is provided on a triacetylcellulose film (TACTD80U (trade name), manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 microns, and the above-mentioned hard coat layer coating solution is formed on the gelatin subbing layer. It was applied using a bar coater and dried at 120 ° C. Next, under a nitrogen atmosphere, an oxygen concentration of 0.1% was applied, and ultraviolet rays were irradiated with an energy of 500 mJ / cm ² to cure the coating layer, thereby forming a hard coat layer having a thickness of 7.5 microns.
Subsequently, the coating solution for the medium refractive index layer was applied onto the hard coat layer using a bar coater, dried at 120 ° C., and then irradiated with ultraviolet rays in a nitrogen atmosphere to cure the coating layer. A layer (refractive index: 1.72, thickness: 81 nm) was formed. Subsequently, the high refractive index layer coating solution was applied onto the middle refractive index layer using a bar coater, dried at 120 ° C., and then adjusted to an oxygen concentration of 0.1% in a nitrogen atmosphere, with 500 mJ / cm ² . The coating layer was cured by irradiating ultraviolet rays with energy to form a high refractive index layer (refractive index: 1.92, thickness: 53 nm). Further, the coating solution for low refractive index layer (present inventions Ln1 to Ln4 and Comparative Examples Ln5 and 6) shown in Table 2 above was applied on the high refractive index layer to a thickness of 85 nm using a bar coater. Under the atmosphere, the oxygen concentration was 0.1%, and ultraviolet rays were irradiated with energy of 750 mJ / cm ² to form a low refractive index layer (refractive index is shown in Table 1 as a cured film refractive index).

Evaluation of performance of antireflection film The antireflection film samples obtained by coating the first to fourth layers on the transparent support thus obtained (the present invention (1) to (7) in Table 3 below, Comparative Example (1), The following performance evaluation was performed for (2).

(1) Average reflectance (%)
Using a spectrophotometer (manufactured by JASCO Corporation), the spectral reflectance at an incident angle of 5 ° was measured in a wavelength region of 380 to 780 nm. The mirror surface average reflectance (%) of 450-650 nm was used for the result.

(2) Pencil Hardness Evaluation After the antireflection film was conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, a pencil hardness evaluation described in JIS K 5400 was performed.

(3) Scratch resistance test The film surface was rubbed 20 times under a load of 200 g using steel wool, and then the level of scratching was confirmed. The determination was in accordance with the following criteria.
Not scratched at all: ◎
Slightly scratched: ○
Fine scratches stand out: △
Scratch is remarkable: ×
The obtained results are shown in Table 3.

  As is clear from the results in Table 3, the antireflection film sample of Comparative Example, Comparative Example (1) has poor film strength, and Comparative Example (2) has high surface reflectance, whereas It can be seen that the antireflection film samples, the present inventions (1) to (7), have a very low surface reflectance and sufficiently strong film strength in a wide wavelength region.

[Creation of display device with anti-reflection film]
On the liquid crystal display surface of personal computer PC9821NS / 340W (trade name) obtained from NEC Corporation, the antireflection film samples of the present invention (1) to (7) and Comparative Examples (1) and (2) created above. The sample was pasted and a display device sample was prepared, and the degree of landscape reflection due to the surface reflection was visually evaluated.
The display device on which the antireflection film sample of the present invention (1) to (7) is installed has almost no surrounding landscape reflection, shows a comfortable visibility and has a sufficient surface strength, and has a comparative example (1), It was superior to the display device provided with the antireflection film sample of (2).

It is sectional drawing which shows the layer structure in case the antireflection film of this invention is a multilayer film (film), (a) shows 4 layer structure, (b) shows the example of 5 layer structure.

Explanation of symbols

1. 1. Low refractive index layer 2. High refractive index layer 3. Hard coat layer 4. Transparent support Medium refractive index layer

Claims (6)

  (A) a copolymer in which the main chain is composed of only carbon atoms and includes a fluorine-containing vinyl constituent component and a constituent component having a (meth) acryloyl group in the side chain, and (B) a fluorine-containing polyfunctional monomer And a low refractive index layer comprising a cured film. The antireflection film according to claim 1, wherein the fluorine-containing polyfunctional monomer is represented by the following general formula 2.

In General Formula 2, Rf represents a chain-like or cyclic q-valent fluorocarbon group containing at least a carbon atom and a fluorine atom, and may contain an oxygen atom and / or a hydrogen atom, and L ₂ has 1 carbon atom. Represents a divalent group of 10 to 10, Y represents a polymerizable group, and q represents an integer of 3 or more. The antireflection film according to claim 2, wherein the fluorine-containing polyfunctional monomer (B) represented by the general formula 2 is represented by the following general formula 3.

In General Formula 3, Rf represents a chain or cyclic q-valent fluorocarbon group containing at least a carbon atom and a fluorine atom, and may contain an oxygen atom and / or a hydrogen atom, and X is hydrogen or carbon number. Represents an alkyl group of 1 to 6, and q represents an integer of 3 or more.   The antireflection film according to claim 1, wherein the weight ratio of the components (A) and (B) is 70:30 to 95: 5.   An antireflection film comprising the antireflection film according to claim 1 on a transparent support. An image display element comprising the antireflection film according to claim 5.

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