JP2005097402A - Curable resin composition, antireflection coating, antireflection film and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition which is a coating type composition having a low reflectance and an excellent scratch resistance, suitably mass-producing a coating, and is also useful for forming a low-refractive index layer of an antireflection coating stable against external stimuli. <P>SOLUTION: The curable resin composition contains a radically reactive group-having fluorine-containing polymer and a polymerization inhibitor. The antireflection coating having the low-refractive index layer formed by curing the resin composition, is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a curable resin composition, an antireflection film, an antireflection film, and an image display device (particularly a liquid crystal display device) using the same. Specifically, the present invention relates to a curable resin composition having a low refractive index and being stable against external stimuli such as heat and shear, and an antireflection film, an antireflection film and an image display device using the same.

  In general, an antireflection film prevents contrast reduction and image reflection due to reflection of external light in an image display device such as a cathode ray tube display (CRT), a plasma display panel (PDP), and a liquid crystal display (LCD). And is placed on the outermost surface of the display to reduce reflectivity using the principle of optical interference.

  Such an antireflection film can be produced by forming a low refractive index layer having an appropriate thickness on the high refractive index layer. It is desirable for mass production to form these layers by applying a coating solution for forming each layer. As a material for forming the low refractive index layer, a material having a refractive index as low as possible is desired from the viewpoint of antireflection performance. At the same time, since it is used for the outermost surface of the display, high scratch resistance is required.

  In order to achieve high scratch resistance, it is most important to provide a sufficient strength and strength to the coating itself. However, the material for forming the low refractive index layer is required to have a low refractive index, and as means for lowering the refractive index of the material, (1) introducing fluorine atoms, (2) reducing the density (introducing voids) Although there is a means, all have a problem that the film strength is impaired and the abrasion resistance is lowered.

  Therefore, various methods for imparting strength to the formed film of the low refractive index layer have been proposed. Specifically, a film is formed with a polymer having a crosslinkable group, and this is cured by a crosslinking reaction. There is. That is, there is a technique that achieves both strength and low refractive index by forming a low refractive index layer with a polymer having a crosslinkable reactive group introduced as much as possible while introducing fluorine that satisfies the refractive index requirement ( For example, see Patent Document 1). As the crosslinking reactive group, a radical polymerizable group is particularly suitable from the viewpoint of reactivity. This proposal makes it possible to achieve both low refractive index properties and scratch resistance.

Such polymers having many cross-linking reactive groups are highly reactive and can form high strength films. On the other hand, the curable composition may be polymerized and gelated by external stimuli such as heat and shear during storage or coating process, and there are still industrial problems. In particular, when applied by a gravure coater, the polymer may partially gel on the gravure roll due to the shearing of the gravure roll and doctor blade, resulting in deterioration of the coated surface.
Japanese Patent Application No. 2002-199203 ([0006] to [0012])

From the background as described above, a liquid curable resin composition that can form a film having a low refractive index and excellent strength and is useful as a low refractive index layer of an antireflection film that is stable against external stimuli. The current situation is what is required.
An object of the present invention is, firstly, a coating-type composition having a low reflectivity, excellent scratch resistance, suitable for mass production of a coating film, and having a low antireflection film that is stable against external stimuli. It is to provide a curable resin composition useful for forming a refractive index layer. The second is to provide a coating-type antireflection film having low reflectance, excellent scratch resistance, and suitable for mass production. Third, the antireflection film is disposed on a transparent support. It is to provide an antireflection film, and fourthly, to provide an image display device in which the antireflection film is disposed.

The object of the present invention has been achieved by the invention having the following constitution.
(1) A curable resin composition comprising a fluorine-containing polymer having a radical reactive group and a polymerization inhibitor.
(2) The curable resin composition according to (1), wherein the radical reactive group is an acryloyl group or a methacryloyl group.
(3) The curable resin composition according to (1) or (2), wherein the fluorine-containing polymer is a polymer compound represented by the following general formula 1.

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms. A represents a polymerized unit derived from any vinyl monomer, and B represents a hydrogen atom or a methyl group. m represents 0 or 1, and x, y, and z represent mol% of each polymerized unit and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65.
(4) Any of (1) to (3), wherein the polymerization inhibitor is a compound belonging to at least one of phenols, quinones, nitro compounds, nitroso compounds, amines, and sulfides The curable resin composition described in 1.
(5) The curable resin composition according to any one of (1) to (4), wherein the polymerization inhibitor is a compound represented by the following general formula 2.

In General Formula 2, R ₁ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ₂ and R ₃ each represent an alkyl group having 1 to 8 carbon atoms.
(6) The addition amount of the polymerization inhibitor is 0.0001 to 10% by mass with respect to the total solid content in the curable resin composition, according to any one of (1) to (5), Curable resin composition.
(7) An antireflection film having a low refractive index layer obtained by curing the curable resin composition described in (1) to (6).
(8) An antireflection film in which the antireflection film according to (7) is provided on a transparent support.
(9) An image display device comprising the antireflection film according to (8).

The curable resin composition of the present invention is stable against external stimuli such as heat and shear, and can form a large-area cured film by coating. Moreover, since the cured film formed from the curable composition of the present invention has a smooth surface, excellent strength, and a low refractive index, it can be suitably applied to a low refractive index layer of an antireflection film.
Moreover, since the antireflection film, antireflection film and image display device of the present invention use the curable resin composition of the present invention, they have a low refractive index and excellent surface strength.

Hereinafter, the present invention will be described in more detail.
First, after describing the curable resin composition of the present invention, an antireflection film, an antireflection film and an image display device using the curable resin composition will be described.

<Curable resin composition>
The curable resin composition of the present invention comprises a fluorine-containing polymer having a radical reactive group and a polymerization inhibitor.
[Fluoropolymer]
The fluorine-containing polymer contained in the curable resin composition of the present invention has a radical reactive group.
Examples of such a fluorine-containing polymer include a fluorine-containing copolymer having a fluorine-containing polymer unit (hereinafter referred to as “fluorine-containing polymer unit”) and a polymer unit having a radical reactive group as constituent components.

  Specific examples of the fluorinated monomer forming the fluorinated polymer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3 -Dioxole, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, “Biscoat 6FM” (trade name, manufactured by Osaka Organic Chemical Co., Ltd.) and M-2020 (trade name, manufactured by Daikin)), complete Alternatively, partially fluorinated vinyl ethers and the like can be mentioned. Perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of refractive index, solubility, transparency, availability, and the like.

The radical reactive group polymerization unit is not particularly limited as long as it is a group having an unsaturated bond that can be polymerized, and examples thereof include an acryloyl group, a methacryloyl group, and an allyl group. Above all,
In particular, an acryloyl group or a methacryloyl group is preferred because of the excellent hardness of the formed film. Hereinafter, these are collectively referred to as “(meth) acryloyl group”.

In order to introduce the radical reactive group into the fluorine-containing polymer, a method of copolymerizing the monomer containing the radical reactive group and the fluorine-containing monomer, a vinyl monomer having no radical reactive group is used as the fluorine-containing polymer. After the copolymerization with the monomer, it can be carried out by a method such as a method in which the radical reactive group is introduced into the fluoropolymer by a polymer reaction, but the latter method is preferably used.
As a method for introducing the radical reactive group by polymer reaction, the following methods (1) to (6) are preferable. In the following methods (1) to (6), the case where a (meth) acryloyl group is used as a radical reactive group is exemplified. However, the following methods (1) to (6) are applied to a (meth) acryloyl group. It is not limited.

(1) After synthesizing a polymer having a nucleophilic group such as hydroxyl group or amino group, (meth) acrylic acid chloride, (meth) acrylic acid anhydride, (meth) acrylic acid and methanesulfonic acid mixed acid anhydride, etc. How to act,
(2) A method of allowing (meth) acrylic acid to act on the polymer having a nucleophilic group in the presence of a catalyst such as sulfuric acid,
(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,
(4) A method of allowing (meth) acrylic acid to act after synthesizing a polymer having an epoxy group,
(5) A method of causing a compound having both an epoxy group such as glycidyl methacrylate and a (meth) acryloyl group to act on a polymer having a carboxyl group,
(6) A method in which dehydrochlorination is performed after polymerizing a vinyl monomer having a 3-chloropropionic acid ester moiety.
Among these, it is particularly preferable to introduce a (meth) acryloyl group (radical reactive group) by the method (1) or (2) for a polymer containing a hydroxyl group.

In addition to the polymer units having the radical reactive group, the fluorine-containing polymer according to the present invention is appropriately copolymerized with a monomer that does not contain a fluorine atom, from the viewpoint of solubility in a solvent, film transparency, and the like. In addition, other polymerization units having no fluorine atom can be contained.
Other monomers that do not contain a fluorine atom forming a polymer unit are not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), (meth) acrylic acid esters (acrylic acid 2 -Ethylhexyl, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane, butyl (meth) acrylate, ethylene Glycol di (meth) acrylate), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, p-hydroxymethylstyrene, etc.), vinyl ethers (methyl vinyl ether, ethyl vinyl) Ether, cyclohexyl vinyl ether, t-butyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, allyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, vinyl butyrate, etc.), acrylamide (N-tert butyl acrylamide, N-cyclohexyl acrylamide, etc.), methacrylamides, acrylonitrile derivatives, unsaturated carboxylic acids (crotonic acid, maleic acid, itaconic acid, etc.), etc., or derivatives thereof.

In the fluorinated polymer according to the present invention, the content of the fluorinated polymer unit is preferably from 30 to 95 mass%, more preferably from 40 to 90 mass%, particularly preferably from 45 to 80 mass%, based on the entire fluorinated polymer. . Further, the content of the polymerization unit having a radical reactive group is preferably 5 to 70% by mass, more preferably 10 to 60% by mass in the entire fluoropolymer, although it depends on the type of fluorine-containing monomer used together. 20-55 mass% is especially preferable.
When the other polymerized units are contained, the content thereof is preferably 0.01 to 45% by mass, more preferably 0.1 to 40% by mass in the whole fluoropolymer.
Further, the fluorine content in the fluoropolymer is preferably 20 to 80% by mass, more preferably 30 to 75% by mass, and particularly preferably 35 to 70% by mass in the entire fluoropolymer.
When the above ranges are satisfied, the formed film is more excellent in low refractive index and exhibits more sufficient scratch resistance.

  The following general formula 1 etc. are mentioned as a preferable form of the said fluorine-containing polymer used for the curable resin composition of this invention.

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms, preferably a linking group having 1 to 6 carbon atoms, and particularly preferably a linking group having 2 to 4 carbon atoms. L may be a straight chain or may have a branched structure, or may have a ring structure. Moreover, when L is a ring structure, it may have a hetero atom selected from O, N, and S.
As a preferable example of L,
* ‐ (CH ₂ ) ₂ -O-**, *-(CH ₂ ) ₂ -NH-**, *-(CH ₂ ) ₄ -O-**, *-(CH ₂ ) ₆ -O- * *, *-(CH ₂ ) ₂ -O- (CH ₂ ) ₂ -O-**, * -CONH- (CH ₂ ) ₃ -O-**, * -CH ₂ CH (OH) CH ₂ -O -**, * -CH ₂ CH ₂ OCONH (CH ₂ ) ₃ -O-**
(* Represents 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, B represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable. A polymer unit having such a structure can be given as a specific example of the polymer unit having the radical reactive group.

In General Formula 1, A 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. Adhesiveness to a substrate, Tg ( 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. It 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, y, and z represent mol% of each polymerization unit, and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65. Preferably, 35 ≦ x ≦ 55, 30 ≦ y ≦ 60, and 0 ≦ z ≦ 20, and particularly preferably 40 ≦ x ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10. Since the total amount of x, y and z is 100, for example, when z is 0, the values of x and y are selected from the above range so that the total amount of x and y is 100. The

  Preferred specific examples (P-1 to P-35) of the fluoropolymer used in the curable resin composition of the present invention are shown below, but the present invention is not limited to these. In addition, the subscript part of () in each chemical formula shows mol% of each superposition | polymerization unit.

  The number average molecular weight of the fluoropolymer is preferably in the range of 600 to 1,000,000, and more preferably in the range of 1000 to 100,000.

[Method for producing fluoropolymer]
The fluorine-containing polymer used in the present invention can be synthesized by various polymerization methods such as solution polymerization, precipitation polymerization, suspension polymerization, precipitation polymerization, bulk polymerization, and emulsion polymerization. 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 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, and the like, and can be from 0 ° C. or lower to 100 ° C. or higher, but it is preferable to perform the polymerization in the range of 50 to 100 ° C.
The reaction pressure may be appropriately selected, preferably 1 to 100 kg / cm ^2, about 1 to 30 kg / cm ² is more preferable. The reaction time is preferably about 5 to 30 hours.
As the reprecipitation solvent for the obtained polymer, isopropanol, hexane, methanol and the like are preferable.

[Blending amount]
The fluorine-containing polymer is preferably 20 to 99.9% by mass, preferably 35 to 99% by mass, of the total solid content in the curable resin composition, from the viewpoint of low refractive index and scratch resistance. More preferably.

[Polymerization inhibitor]
The curable resin composition of the present invention contains a polymerization inhibitor as an essential component.
Examples of the polymerization inhibitor that can be suitably used in the present invention include hydroquinone, hydroquinone monomethyl ether, mono-tert-butylhydroquinone, catechol, p-tert-butylcatechol, p-methoxyphenol, p-tert-butylcatechol, Phenols such as 2,6-di-tert-butyl-m-cresol, pyrogallol and β-naphthol, quinones such as benzoquinone, 2,5-diphenyl-p-benzoquinone, p-toluquinone and p-xyloquinone; nitrobenzene, Nitro compounds or nitroso compounds such as m-dinitrobenzene, 2-methyl-2-nitrosopropane, α-phenyl-tert-butylnitrone, 5,5-dimethyl-1-pyrroline-1-oxide; chloranil-amine, diphenylamine, The E sulfonyl picryl hydrazine, phenol -α- naphthylamine, pyridine, amines such as phenothiazine; dithio benzoylsulfamoyl sulfide, a radical polymerization inhibitor of sulfides or the like, such as dibenzyl tetrasulfide and the like. These may be used alone or in combination.
More preferred are compounds belonging to at least one of phenols, quinones, nitro compounds, nitroso compounds, amines and sulfides. Among them, it is preferable to use phenols because of high radical scavenging ability and low refractive index of the resulting film.

  A particularly preferred polymerization inhibitor used in the curable resin composition of the present invention includes a compound represented by the following general formula 2. By using the compound represented by the following general formula 2, not only heat but particularly high stability against shearing can be imparted to the curable resin composition.

In General Formula 2, R ₁ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R ₁ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.
R ₂ and R ₃ each represent an alkyl group having 1 to 8 carbon atoms, and may be linear or have a branched structure or a ring structure. R ₂ and R ₃ are preferably a structure represented by * —C (CH ₃ ) ₂ —R ′ containing a quaternary carbon (* represents a site connected to an aromatic ring, and R ′ represents 1 to 5 carbon atoms. Represents an alkyl group.
R ₂ is more preferably a t-butyl group, a t-amyl group or a t-octyl group. R ₃ is more preferably a t-butyl group or a t-amyl group. As such a compound, Sumilizer GM, Sumilizer GS (both trade names, manufactured by Sumitomo Chemical Co., Ltd.) and the like are listed as commercially available compounds.

  Examples of polymerization inhibitors (I-1 to I-34) preferably used in the present invention are shown below, but the present invention is not limited to these. I-1 to I-18 correspond to the specific examples of the general formula 2, but I-19 to I-34 are other compounds.

  These polymerization inhibitors are preferably added in an amount of 0.0001 to 10% by mass with respect to the total solid content in the curable resin composition in order to exhibit sufficient stability against external stimuli. More preferably, it is 0.0001-5 mass%, Most preferably, it is 0.001-2 mass%.

[Other ingredients]
From the viewpoint of film hardness, an additive such as a curing agent may be added. For example, a curing agent such as a polyfunctional (meth) acrylate compound, a polyfunctional epoxy compound, a polyisocyanate compound, an aminoplast, a polybasic acid or an anhydride thereof, or inorganic fine particles such as silica can be added in a small amount. When adding these, it is preferable that it is the range of 0-30 mass% with respect to the total solid of a curable resin composition, It is more preferable that it is the range of 0-20 mass%, 0-10 mass % Range is particularly preferred.

  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 of the total solid content of the low n layer, more preferably 0 to 10% by mass. Especially preferably, it is a case of 0-5 mass%.

Moreover, it is preferable to add a radical polymerization initiator in order to allow the radical reaction by the radical reactive group to proceed smoothly and to sufficiently exhibit the scratch resistance.
The radical polymerization initiator may be in any form of generating radicals by the action of heat or generating radicals by the action of light.

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-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile, 2-azo-bis-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 radical polymerization initiator added is not particularly limited as long as the radical reactive group is an amount capable of initiating a polymerization reaction, but is generally 0.1 to the total solid content in the curable resin composition. 15 mass% is preferable, More preferably, it is 0.5-10 mass%, Most preferably, it is 2-5 mass%.

  The curable resin composition of the present invention may contain a solvent. The solvent that can be used is not particularly limited as long as the composition containing the fluorine-containing polymer is uniformly dissolved or dispersed without causing precipitation, and two or more kinds of solvents may 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 curable resin composition of the present invention as necessary.
The curable resin composition of the present invention can be used by coating on a high refractive index layer, a medium refractive index layer, and other various substrates, which will be described later, and curing to form a film.
And since the curable resin composition of this invention contains the said fluorine-containing polymer which has the said radical reactive group, and the said polymerization inhibitor as mentioned above, it is excellent also in the intensity | strength of the film formed by low refractive index. In addition, gelation does not occur during storage or external stimuli in the coating process.

<Antireflection film>
The antireflection film of the present invention has a low refractive index layer obtained by curing the curable resin composition of the present invention.
The antireflection film of the present invention may have a single layer structure or a multilayer structure. That is, when the antireflection film has a single layer structure, it consists of only a low refractive index layer. When the antireflection film has a multilayer structure, the antireflection film comprises two or more layers having at least a low refractive index layer. The antireflection film preferably has a multilayer structure, and has a two-layer structure of the low refractive index layer and a high refractive index layer, or a three-layer structure having an intermediate refractive index layer between the low refractive index layer and the high refractive index layer. Is preferred.
[Low refractive index layer]
The low refractive index layer is a layer formed by curing the curable resin composition of the present invention. As will be described later, it is disposed on the upper layer of the high refractive index layer. That is, the upper surface of the low refractive index layer becomes the surface of the antireflection film.
The refractive index of the low refractive index layer is 1.20 to 1.49, more preferably 1.20 to 1.45, and particularly preferably 1.20 to 1.43. 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 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.

[High refractive index layer and medium refractive index layer]
In the antireflection film of the present invention, the high refractive index layer and the medium refractive index layer used in combination with the low refractive index layer are layers having a higher refractive index than the low refractive index layer. The medium refractive index layer is a layer having a refractive index higher than that of the low refractive index layer and lower than that of the high refractive index layer.

The high refractive index layer and the medium refractive index layer are mainly composed of only an organic material or an organic material and an inorganic material, respectively.
Examples of the organic material used here include thermoplastic resin compositions (eg, polystyrene, polystyrene copolymer, polycarbonate, polymers having aromatic rings other than polystyrene, heterocyclic rings, and alicyclic groups, or halogen groups other than fluorine. A polymer (eg, a resin composition using a melamine resin, a phenol resin, or an epoxy resin as a curing agent); a urethane resin-forming composition (eg, an alicyclic or aromatic isocyanate and a polyol). And a radically polymerizable composition (a modified resin composition or a composition containing a modified prepolymer that can be radically cured by introducing a double bond into the polymer or monomer). be able to. The organic material used for the high refractive index layer or the medium refractive index layer is preferably a material having a high film forming property.

An organic material and an inorganic material can be used in combination for the high refractive index layer or the medium refractive index layer. When an organic material and an inorganic material are used in combination, a high refractive index can generally be secured by the inorganic material, and therefore, an organic material having a lower refractive index than that used when the organic material is used alone can be used. Examples of such organic materials include copolymers of acrylic monomers such as pentaerythritol hexaacrylate and vinyl monomers, polyesters, alkyd resins, fibrous polymers, urethane resins, and various types of resins that cure these resins. And a composition containing a curing agent or a compound having a curable functional group. These organic materials are transparent and can disperse inorganic materials stably.
Specific examples of the compound having a curable functional group include trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol. Polyurethane poly (meth) acrylates such as penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate, urethane obtained by reaction of polyisocyanate and hydroxyl-containing (meth) acrylate such as hydroxyethyl (meth) acrylate ( And (meth) acrylate.

Furthermore, an organically substituted silicon compound can be used as the organic material. Examples of the silicon-based compound include a compound represented by the following general formula 3 or a hydrolysis product thereof.
General formula 3: R ^a _m R ^b _n SiZ _(4-mn)
Here, R ^a and R ^b each represents an alkyl group, an alkenyl group, an allyl group, or a hydrocarbon group substituted with halogen, epoxy, amino, mercapto, methacryloyl, or cyano, and Z represents an alkoxy group, an alkoxyalkoxy It represents a hydrolyzable group selected from a group, a halogen atom, and an acyloxy group, and m and n are 0, 1 or 2, respectively, under the condition that m + n is 1 or 2.

  Examples of the inorganic material include inorganic fine particles. Preferable inorganic compounds constituting the inorganic fine particles include oxides of metal elements such as aluminum, titanium, zirconium and antimony. The inorganic fine particles are commercially available as a powder or a colloidal dispersion in which the powder is dispersed in a solvent such as water. When using these, it is preferable to mix and disperse in the said organic material or organosilicon compound.

Further, as the inorganic material, an inorganic material that can be dispersed in a solvent with a film-forming property or that is liquid itself can be used. Examples of such inorganic materials include alkoxides of various elements, salts of organic acids, coordination compounds (eg, chelate compounds) bonded to coordination compounds, and inorganic polymers).
More specifically, titanium tetraethoxide, titanium tetra-i-propoxide, titanium tetra-n-propoxide, titanium tetra-n-butoxide, titanium tetra-sec-butoxide, titanium tetra-tert-butoxide, aluminum tri Ethoxide, aluminum tri-i-propoxide, aluminum tributoxide, antimony triethoxide, antimony riboxide, zirconium tetraethoxide, zirconium tetra-i-propoxide, zirconium tetra-n-propoxide, zirconium tetra-n- Metal alcoholate compounds such as butoxide, zirconium tetra-sec-butoxide and zirconium tetra-tert-butoxide; diisopropoxytitanium bis (acetylacetonate), dibutoxytitanium bis ( Acetylacetonate), diethoxytitanium bis (acetylacetonate), bis (acetylacetonezirconium), aluminum acetylacetonate, aluminum di-n-butoxide monoethylacetoacetate, aluminum di-i-propoxide monomethylacetoacetate and tri- Examples include chelate compounds such as n-butoxide zirconium monoethyl acetoacetate; and inorganic polymers mainly composed of carbon zirconyl ammonium or zirconium.

In addition to the compounds listed above, compounds having a relatively low refractive index can be used in combination for the high refractive index layer and the medium refractive index layer. Examples of such a compound include various alkyl silicates or hydrolysates thereof, particulate silica, particularly silica gel dispersed in colloidal form.
In addition, a dispersion solvent or a solvent can be used for the high refractive index layer and the medium refractive index layer. Examples of the dispersion solvent or solvent include cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone toluene, toluene, ethyl acetate, DMF, 2-propanol, and n-butanol.
Furthermore, additives that are usually added to conventional antireflection films can be appropriately used in the high refractive index layer and the medium refractive index layer.

  As an embodiment of the high refractive index layer and the medium refractive index layer, a dispersion of the above inorganic material, a monomer such as dipentaerythritol hexaacrylate, a polymerization initiator such as a photopolymerization initiator and a thermal polymerization initiator, Examples thereof include those formed using a layer-forming composition obtained by dissolving a sensitizer and a catalyst used as necessary in a solvent (the same as the dispersion medium can be exemplified). For such a configuration, a configuration related to a high refractive index layer and a medium refractive index layer in a conventional antireflection film is appropriately applied.

  The refractive index of the high refractive index layer is preferably in the range of 1.57 to 2.40. 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 strength of the high refractive index layer is preferably 1H or more, more preferably 2H or more, and most preferably 3H or more, 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 in the range of 1.50 to 1.85. 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. The thickness of the medium 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 strength of the medium refractive index layer is preferably 1 H or more, more preferably 2H or more, and most preferably 3H or more, with a pencil hardness of 1 kg load.

[Method of forming antireflection film]
The antireflective film of the present invention is formed by applying the composition for forming the high refractive index layer or the medium refractive index layer to various base materials, etc., performing light irradiation or the like, and curing the high refractive index layer. Are formed by coating the curable resin composition for the low refractive index layer on the high refractive index layer or the medium refractive index layer, and further curing by applying light irradiation or heating. be able to.

<Antireflection film>
The antireflection film of the present invention is obtained by providing the antireflection film of the present invention on a transparent support.
A basic configuration of an antireflection film suitable as an embodiment of the antireflection film of the present invention will be described with reference to the drawings.
Fig.1 (a) is a schematic diagram which shows the cross section of one Embodiment of this invention.
The antireflection film shown in FIG. 1A has an antireflection film 1 in which a high refractive index layer 4 and a low refractive index layer 3 are formed in this order on a transparent support 5.
In such a configuration, as described in JP-A-59-50401, when the high refractive index layer 4 satisfies the following formula (I) and the low refractive index layer 3 satisfies the following formula (II), It is preferable because an antireflection film having excellent antireflection performance can be obtained.

Formula (I): (mλ / 4) × 0.7 <n ₁ d ₁ <(mλ / 4) × 1.3

In the formula, 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.

Formula (II): (nλ / 4) × 0.7 <n ₂ d ₂ <(nλ / 4) × 1.3

Where 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 the transparent support, and the refractive index n ₂ of the low refractive index layer is generally 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. Further, the refractive index n ₁ of the high refractive index layer is generally in the range of 1.57 to 2.40.

  Further, as described above, the antireflection film of the present invention may have a structure having an antireflection film composed of two layers of a low refractive index layer and a high refractive index layer, and further, an intermediate refractive index layer, a hard coat layer, etc. It is preferable to form a layer in advance and to have three or more antireflection films on which a low refractive index layer and a high refractive index layer are formed according to the method described above. More preferably, it is a form in which three or more layers of middle, high and low refractive index layers are laminated. An embodiment of such an antireflection film is shown in FIG.

That is, in the antireflection film shown in FIG. 1B, the hard coat layer 6, the medium refractive index layer 7, the high refractive index layer 4, and the low refractive index layer 3 are formed in this order on the transparent support 5. The antireflection film 2 is provided.
In such a configuration, as described in JP-A-59-50401, the medium refractive index layer 7 is represented by the following formula (III), the high refractive index layer 4 is represented by the following formula (IV), and the low refractive index layer. 3 preferably satisfies the following formula (V).

Formula (III): (hλ / 4) × 0.7 <n ₃ d ₃ <(hλ / 4) × 1.3

Where 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.

Formula (IV): (jλ / 4) × 0.7 <n ₄ d ₄ <(jλ / 4) × 1.3

Where 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.

Formula (V): (kλ / 4) × 0.7 <n ₅ d ₅ <(kλ / 4) × 1.3

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.

As described above, the refractive index n ₃ of the middle refractive index layer is preferably in the range of 1.50 to 1.85, and the refractive index n ₄ of the high refractive index layer is generally in the range of 1.57 to 2.40. Good.
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, medium refractive index, and low refractive index described here refer to the relative refractive index between layers. For example, 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.

[Other layers]
The antireflection film can be provided with a hard coat layer as described above, and may further be provided with a moisture proof layer, an antistatic layer, an undercoat layer and 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]
As the transparent support that can be preferably used in the present invention, a plastic film is more preferable than a glass plate as the transparent support. Examples of plastic film materials include cellulose acylates (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, nitrocellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate). Phthalate, 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, polymethyl Methacrylate and polyether ketone are included. Cellulose acylate, polycarbonate, polyethylene terephthalate and polyethylene naphthalate are preferred, cellulose acylate is more preferred, and triacetyl cellulose is further preferred.
The thickness of the cellulose acylate film varies depending on the purpose of use, but is usually in the range of 5 to 500 μm, more preferably in the range of 20 to 250 μm, and most preferably in the range of 30 to 180 μm. In addition, as an optical use, the range of 30-110 micrometers is especially preferable. About manufacturing a cellulose acylate film using a non-chlorinated solvent, it is described in detail in JIII Journal of Technical Disclosure No. 2001-1745, and the cellulose acylate film described here is also preferably used in the present invention. it can.

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.

[Method for forming antireflection film]
Each layer of the antireflection film is transparently supported by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method or an extrusion coating method (described in US Pat. No. 2,681,294). It can be formed by coating directly on the body or via another layer. Two or more layers may be applied simultaneously. The methods of simultaneous application are described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973). The antireflection film of the present application is preferably dried after applying the coating composition of each layer and cured by ionizing radiation or heat. It is preferable to use ionizing radiation, and in the case of curing using ultraviolet rays, ultraviolet rays emitted from light rays such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp can be used.

The lower the reflectance of the antireflection film, the better. The average reflectance of the antireflection film is preferably 2% or less, more preferably 1% or less, and most preferably 0.7% or less in the wavelength region of 450 to 650 nm. The haze of the antireflection film (when it has no anti-glare function described below) 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 H or higher, more preferably 2H or higher, 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. When fine particles are used for the low refractive index layer, irregularities can be formed on the surface of the antireflection film by the fine particles. When the antiglare function obtained by the fine particles is insufficient, a small amount (0.1 nm) of relatively large particles (particle size: 50 nm to 2 μm) is added to the low refractive index layer, high refractive index layer, medium refractive index layer or hard coat layer. ˜50 mass%) may be added.
In addition, the antireflection film enlarges the viewing angle (particularly the downward viewing angle) of the liquid crystal display device, and suppresses a decrease in contrast, gradation or black / white inversion, or hue change even when the viewing angle in the viewing direction changes. It may have a light diffusion function. This light diffusing function can be realized by the effect of internal scattering of the translucent fine particles when the antireflection film contains the translucent fine particles. When the antireflection film has an antiglare function and / or a light diffusion function, the haze of the antireflection film is preferably 3 to 60%, and more preferably 4 to 40%.

<Image Display Device> The image display device of the present invention includes the antireflection film of the present invention.
Examples of the image display device include a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), and a cathode ray tube display device (CRT). In the image display device of the present invention, it is desirable that the transparent support side of the antireflection film is bonded to the image display surface of the image display device. The antireflection film of the present invention can also be used for a case cover, an optical lens, a spectacle lens, a window shield, a light cover, and a helmet shield.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these.
1) Synthesis of fluorinated polymer 1 (P-1) 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether and 0.55 g of dilauroyl peroxide were charged into a 100 ml stainless steel autoclave with a stirrer, and the inside of the system was deaerated. And replaced with nitrogen gas. Furthermore, 25 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 5.4 kg / cm ² . The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 3.2 kg / cm ² , the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. Drying gave 28 g of polymer.
Next, 20 g of this polymer was dissolved in 100 ml of N, N-dimethylacetamide, and 11.4 g of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 19 g of P-1. The resulting polymer had a refractive index of 1.421.

2) Synthesis of fluoropolymer (P-21) 31.0 g of ethyl acetate, 10.01 g of glycidyl vinyl ether (GVE), 1.80 g of ethyl vinyl ether (EVE) and peroxidation in a stainless steel autoclave with a capacity of 100 ml 0.398 g of dilauroyl was charged, the inside of the system was deaerated and replaced with nitrogen gas. Further, 18.78 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 5.4 kg / cm ² . The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 3.2 kg / cm ² , the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The reaction solution was added to a large excess of n-hexane. The polymer obtained was dissolved in a small amount of ethyl acetate and reprecipitated twice to completely remove the residual monomer. Drying gave 17.7 g of polymer.
Next, 15 g of this polymer was dissolved in 40 ml of methyl isobutyl ketone (MIBK), 10.5 g of acrylic acid, 128 mg of triethylbenzylammonium chloride, 84 mg of Irganox 1010 manufactured by Ciba Geigy Co. as a polymerization inhibitor were added thereto, and the mixture was stirred at 100 ° C. for 5 hours. did. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 12.2 g of P-21. The obtained polymer had a refractive index of 1.427.

(Preparation of curable resin composition)
The components shown in Table 1 below were mixed and dissolved in methyl ethyl ketone, and then filtered through a polytetrafluoroethylene filter having a pore size of 0.25 μm to prepare a curable resin composition.
In the table, Irg907 represents Ciba Geigy photopolymerization initiator Irgacure 907 (trade name), and DPHA represents dipentaerythritol hexaacrylate.
The values in parentheses in Table 1 represent the mass ratio of each component during drying. Moreover, the polymerization inhibitor was described in [] as an addition amount with respect to the total solid content in the curable resin composition. Any photopolymerization initiator was added at a ratio of 5% by mass with respect to the total solid content in the curable resin composition.
Moreover, in Table 1, each symbol (P-1, P-21, I-18, etc.) described in the column of the fluorine-containing polymer and the polymerization inhibitor corresponds to the number of the exemplified compound described above. In addition, there are polymers for which no synthesis example is shown, but all of them could be synthesized in the same manner as in the above synthesis examples 1) and 2).

(Evaluation of curable resin composition)
The following items were evaluated about the adjusted curable resin composition. The results are shown in Table 2.
(1) Evaluation of storage stability The curable resin composition was placed in a light-shielding container and stored for one week in a thermostatic bath set at 40 ° C., and then the amount of change in double bonds was measured. The amount of double bonds was determined by an infrared spectrophotometer for the resin composition before and after storage. That is, absorption due to stretching vibration of a carbonyl group in the vicinity of 1700 cm ⁻¹ (the integrated value of this peak is assumed to be a), and absorption due to bending vibration of a double bond near 810 cm ⁻¹ (the integrated value of this peak is referred to as b). Ratio) (= b / a) was determined before and after storage. Further, the value of b / a before aging was x, the value after aging was y, and the value of y / x was calculated as the double bond residual rate.

(2) Evaluation of process stability In order to evaluate stability against shearing by a gravure coater, a microgravure roll having a diameter of 180 lines / inch and a gravure pattern having a depth of 40 μm and a doctor blade and a doctor blade are used. In a gravure coater equipped with a shearing force for 30 minutes at a gravure roll rotational speed of 30 rpm, the resin composition was taken out and (1) double bond before and after shearing as in the storage stability evaluation. The survival rate was determined.

(Creation of antireflection film)
In order to evaluate the performance as an antireflection film, an antireflection film was prepared by the following operation.

(Preparation of titanium dioxide dispersion)
Titanium dioxide fine particles having a core / shell structure (TTO-55B, shell material: 9% by mass of the whole alumina particles, manufactured by Ishihara Sangyo Co., Ltd.) 30 parts by weight, cross-linking reactive group-containing polymer P- (1) 4.5 parts by weight Part, 0.3 parts by weight of a commercially available cationic monomer (DMAEA, manufactured by Kojin Co., Ltd.) and 65.2 parts by weight of cyclohexanone were dispersed by a sand grinder mill to prepare a titanium dioxide dispersion having a weight average diameter of 53 nm. .

(Preparation of coating solution for medium refractive index layer)
18.08 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA (trade name), manufactured by Nippon Kayaku Co., Ltd.) and a photopolymerization initiator (Irgacure) were added to 49.60 g of the titanium dioxide dispersion. 907, manufactured by Ciba Geigy Co., Ltd.), 0.920 g of photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.), 0.307 g of methyl ethyl ketone, and 500 g of cyclohexanone were added and stirred. The solution was filtered through a polypropylene filter having a pore diameter of 0.4 μm to prepare a coating solution for forming a middle refractive index layer.

(Preparation of coating solution for high refractive index layer)
To 110.0 g of the titanium dioxide dispersion, 6.29 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA (trade name), manufactured by Nippon Kayaku Co., Ltd.), photopolymerization initiator (Irgacure) 907, manufactured by Ciba Geigy Co., Ltd.), photosensitizer (Kaya Cure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.173 g, methyl ethyl ketone 230.0 g and cyclohexanone 460.0 g were added and stirred. A coating solution for forming a high refractive index layer was prepared by filtering through a polypropylene filter having a pore diameter of 0.4 μm.

(Preparation of coating solution for hard coat layer)
125 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA (trade name), Nippon Kayaku Co., Ltd.) and urethane acrylate oligomer (UV-6300B (trade name), Nippon Synthetic Chemical Industry Co., Ltd. 125 g) 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 coating solution for forming a hard coat layer.

(Coating each layer)
The antireflection film shown in FIG. 1B was manufactured as follows.
On the triacetyl cellulose film (TD80U (trade name), manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm as the transparent support 5, the hard coat layer coating solution was applied using a bar coater. After drying at 90 ° C., the coating layer was cured by irradiating with ultraviolet rays to form a hard coat layer 6 having a thickness of 6 μm.
On the hard coat layer 6, the medium refractive index layer coating solution was applied using a bar coater. After drying at 60 ° C., the coating layer was cured by irradiating with ultraviolet rays to form a medium refractive index layer 7 (refractive index 1.70, film thickness 70 nm, TTB-55B, 21% by volume).
On the middle refractive index layer 7, the coating liquid for high refractive index layer was applied using a bar coater. After drying at 60 ° C., the coating layer was cured by irradiating with ultraviolet rays to form a high refractive index layer 4 (refractive index 1.95, film thickness 75 nm).
On the high refractive index layer 4, the curable resin composition shown in Table 1 (present inventions S1 to S13 and Comparative Examples S14 to S16) and the same procedure as the evaluation of the curable resin composition were performed at 40 ° C. The curable resin composition to which shearing with a gravure coater was applied was applied using a bar coater, dried at 90 ° C., then irradiated with ultraviolet rays in a nitrogen atmosphere, and further at 120 ° C. for 10 minutes. The mixture was heated and then allowed to cool to room temperature to form a low refractive index layer 3 (film thickness 85 nm), whereby an antireflection film 2 was produced.

(Evaluation of antireflection film)
The obtained antireflection film was tested for the following evaluation items. The results are shown in Table 2.
(1) Evaluation of coating film surface shape Antireflection film provided with a low refractive index layer comprising a curable resin composition not subjected to aging at 40 ° C. and shearing by a gravure coater (hereinafter referred to as A) An antireflective film (hereinafter referred to as “B”) comprising a low refractive index layer comprising a curable resin composition with aging at 40 ° C., and a curable resin composition to which shearing is applied by a gravure coater About the anti-reflective film (henceforth C) provided with the low-refractive-index layer, the coating surface shape was evaluated. The determination was in accordance with the following criteria.
Observed with an optical microscope (100 times), the coated surface is smooth and no foreign matter is seen: ○
Observation with an optical microscope (100x) shows foreign matter on the coated surface: ×
The following evaluations were all performed on the antireflection film A.
(2) Evaluation of average reflectance Using a spectrophotometer (manufactured by JASCO Corporation), a 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.
(3) 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.
(4) Evaluation of scratch resistance The prepared film was rubbed 20 times under a load of 500 g / cm ² using steel wool # 0000, and then the level of scratching was confirmed. The determination was in accordance with the following criteria.
Not at all ： ○
Small scratches: △
Scratch is remarkable: ×

  As is clear from the results shown in Table 2, the curable resin composition of the present invention has excellent storage stability, is stable against shearing during coating, and the cured film has excellent strength but low refraction. Therefore, the antireflection film (antireflection film) formed by using this exhibits excellent characteristics. On the other hand, in Comparative Examples 1 to 3, there is no abnormality in the strength, surface shape, and reflectance of the cured film under conditions without shearing or heating, but the resin composition is unstable with respect to heat and shear. Yes, when such an external stimulus is applied, the polymerization progresses inhomogeneously, so that the coated surface is deteriorated.

1A and 1B are schematic views each showing a cross section of an embodiment of the antireflection film of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Antireflection film 3 Low refractive index layer 4 High refractive index layer 5 Transparent support 6 Hard-coat layer 7 Middle refractive index layer

Claims (9)

  A curable resin composition comprising a fluorine-containing polymer having a radical reactive group and a polymerization inhibitor.   The curable resin composition according to claim 1, wherein the radical reactive group is an acryloyl group or a methacryloyl group. The curable resin composition according to claim 1 or 2, wherein the fluoropolymer is a polymer compound represented by the following general formula 1.

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms. A represents a polymerized unit derived from any vinyl monomer, and B represents a hydrogen atom or a methyl group. m represents 0 or 1, and x, y, and z represent mol% of each polymerized unit and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65.   The curability according to any one of claims 1 to 3, wherein the polymerization inhibitor is a compound belonging to at least one of phenols, quinones, nitro compounds, nitroso compounds, amines, and sulfides. Resin composition. The curable resin composition according to claim 1, wherein the polymerization inhibitor is a compound represented by the following general formula 2.

In General Formula 2, R ₁ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ₂ and R ₃ each represent an alkyl group having 1 to 8 carbon atoms.   6. The curable resin composition according to claim 1, wherein the addition amount of the polymerization inhibitor is 0.0001 to 10% by mass with respect to the total solid content in the curable resin composition. Stuff.   An antireflection film having a low refractive index layer obtained by curing the curable resin composition according to claim 1.   An antireflection film, wherein the antireflection film according to claim 7 is provided on a transparent support.   An image display device comprising the antireflection film according to claim 8.

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