JPH1025388A - Curable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition useful for an antireflection film, an optical fiber sheath material, etc., excellent in thermosetting properties, adhesiveness to substrates, compatibility with a curing agent, etc., transparency after curing and durability, comprising a specific curable fluorine-containing copolymer. SOLUTION: This composition comprises a curable fluorine-containing copolymer obtained by reacting (A) a fluorine-containing copolymer prepared by copolymerizing at least (A1 ) a fluorine atom-containing monomer such as a compound of the formula CH2 =CH-O-Ff [Rf is a fluorine atom-containing (alkoxy)alkyl] and (A2 ) an OH- or epoxy-containing monomer such as 2- hydroxyethyl vinyl ether or vinyl glhycidyl ether with (B) at least a hydroxyalkylamino- or alkoxyalkylamino-containing compound such as methylolated melamine or an alkoxylated methylmelamine, for example, in an amount of 1-70 pts.wt. based on 100 pts.wt. of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a curable resin composition capable of forming a coating film having excellent transparency, durability and low reflectance characteristics. Particularly, the present invention relates to a curable resin composition suitable as a coating material for optical materials.

[0002]

2. Description of the Related Art Melamine resins and urea resins have been widely known as amino resins, and derivatives thereof have also been known as curing agents for polymers having functional groups such as hydroxyl groups, epoxy groups and carboxyl groups. In particular, in the case of baking paint, it is suitably used as a curing agent for forming a hard and durable coating film. In general, a coating film is formed by mixing a curing agent and an acid catalyst with an organic solvent solution or an aqueous dispersion of a functional group-containing polymer as a main component, and applying, drying, and heat-curing. In recent years, a fluorine-containing polymer has been proposed as a weather-resistant paint.
No. 07 proposes a fluorine-containing copolymer having a functional group consisting of a fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether and hydroxyalkyl vinyl ether.
No. 1 and Japanese Patent Application Laid-Open No. 62-292848 propose a copolymer comprising hexafluoropropylene, vinyl carboxylate, alkyl vinyl ether and hydroxyl group-containing vinyl ether, and a method of curing the copolymer with melamine or isocyanate. Further, JP-A-5-5
No. 1551 proposes a method of curing a copolymer comprising hexafluoropropylene, vinyl carboxylate, alkyl vinyl ether, vinyl ether containing hydroxyl group and vinyl monomer containing carboxyl group with melamine or isocyanate.

[0003]

However, conventional proposals have been made for general paints having a low fluorine content, and are capable of forming transparent low-refractive-index coatings, particularly for optical material coatings. No useful material is known yet. That is, the conventional curable composition was inferior in the transparency of the coating film. Many of the reasons are due to the fact that the conventionally proposed fluorinated paint has insufficient compatibility between the fluorine-containing polymer and the curing agent. Further, in optical applications such as an anti-reflection film, the coating film thickness for effectively exhibiting anti-reflection performance is 130 n which is １ ／ of the wavelength of a typical visible light.
m, but the adhesion of such a thin film coating was not sufficient.

The present invention provides high transparency and n _D = 1.40.
The present invention provides a curable resin composition which is capable of forming a coating film having the following low refractive index, and in which these properties and the hardness of the coating film are well-balanced and suitable for forming a coating film of an optical material. Is what you do. Still another object of the present invention is to provide
Even when a curing agent and / or a curing catalyst is further added, the curable resin composition is excellent in compatibility between the curable resin composition and the curing agent and / or the curing catalyst, and is suitable for forming a coating film of an optical material. Is provided.

[0005]

The present invention relates to a fluorine-containing compound obtained by polymerizing (A) at least (a) a monomer containing a fluorine atom and (b) a monomer containing a hydroxyl group or an epoxy group. A compound containing (B) at least a hydroxyalkylamino group or an alkoxyalkylamino group (hereinafter simply referred to as "amino compound") in a copolymer (hereinafter simply referred to as "fluorinated copolymer"). A curable resin composition containing a curable fluorinated copolymer (hereinafter, simply referred to as “curable fluorinated copolymer”) obtained by reacting the above. Hereinafter, the configuration of the present invention will be described in detail.

<Fluorine-Containing Copolymer> The curable fluorine-containing copolymer of the present invention comprises (A) at least (a) a monomer containing a fluorine atom and (b) a monomer containing a hydroxyl group or an epoxy group. Fluorine-containing copolymer obtained by polymerizing the body,
(B) A curable fluorine-containing copolymer obtained by reacting an amino compound containing at least a hydroxyalkylamino group or an alkoxyalkylamino group. First, the fluorinated copolymer will be described.

The fluorine-containing copolymer of the present invention is obtained by polymerizing at least (a) a monomer containing a fluorine atom and (b) a monomer containing a hydroxyl group or an epoxy group. The (a) monomer containing a fluorine atom (hereinafter, also simply referred to as “component (a)”) includes at least one polymerizable unsaturated double bond group and at least one fluorine atom. Compounds having, specifically,
For example, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene,
Fluoroolefins such as 3,3,3-trifluoropropylene and tetrafluoroethylene; represented by the general formula CH ₂ ＣＨCH—O—Rf (Rf represents an alkyl group or an alkoxyalkyl group containing a fluorine atom) ( Perfluoro (alkyl vinyl ether) such as perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), perfluoro (butyl vinyl ether), and perfluoro (isobutyl vinyl ether) Perfluoro (alkoxyalkyl vinyl ether) s such as perfluoro (propoxypropyl vinyl ether);
2,2,2-trifluoroethyl (meth) acrylate,
2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) ethyl (meth)
Fluorine-containing (meth) acrylates such as acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, and 2- (perfluorodecyl) ethyl (meth) acrylate And the like. These monomers containing a fluorine atom may be used alone or in combination of two or more. Particularly, it is preferable to use hexafluoropropylene in combination with perfluoroalkyl perfluorovinyl ether or perfluoroalkoxyalkyl perfluorovinyl ether as the fluorine-containing monomer.

The above-mentioned monomer (b) containing a hydroxyl group or an epoxy group (hereinafter, also simply referred to as “component (b)”) is
A compound having at least one polymerizable unsaturated double bond group and at least one hydroxyl group or epoxy group can be exemplified. Specific examples of the monomer containing a hydroxyl group include, for example, 2-hydroxyethyl vinyl ether,
-Hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 5-
Hydroxyl-containing vinyl ethers such as hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether; hydroxyl-containing allyl ethers such as 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether and glycerol monoallyl ether; allyl alcohol; hydroxyethyl (meth) An acrylate ester etc. can be mentioned. Examples of monomers containing an epoxy group include, for example, vinyl glycidyl ether, allyl glycidyl ether, glycidyl (meth) acrylate,
Glycidyl crotonate, methyl glycidyl maleate and the like can be mentioned. These monomers containing a hydroxyl group or an epoxy group may be used alone or in combination of two or more.

Further, the fluorine-containing copolymer of the present invention can be optionally copolymerized with a monomer other than (a) a monomer containing a fluorine atom and (b) a monomer containing a hydroxyl group or an epoxy group. (Hereinafter referred to as “other monomer” or simply “component (c)”).
Examples of such other monomers include compounds having at least one polymerizable unsaturated double bond group, and specific examples thereof include α, such as ethylene, propylene, and isobutene.
-Olefins: methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether,
alkyl vinyl ethers or cycloalkyl vinyl ethers such as n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n-dodecyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate Carboxylic acid vinyl esters such as vinyl caproate, vinyl versatate and vinyl stearate; methyl (meth) acrylate, ethyl (meth) acrylate,
n-butyl (meth) acrylate, isobutyl (meth)
Acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-
(Meth) acrylic esters such as (n-propoxy) ethyl (meth) acrylate; (meth) acrylic acid,
Examples thereof include carboxyl group-containing monomer compounds such as crotonic acid, maleic acid, fumaric acid, and itaconic acid. These other monomers may be used alone or in combination of two or more.

Among the other monomers, alkyl vinyl ethers, cycloalkyl vinyl ethers and vinyl carboxylate are preferably used from the viewpoint of increasing the yield in the polymerization reaction of the fluorine-containing copolymer of the present invention. You.
Particularly in terms of increasing the fluorine content copolymerized in the fluorinated copolymer, for example, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, etc. Molecular weight monomers are preferred. Further, in order to increase the hardness and lower the refractive index of the coating film after curing of the curable resin composition, it is effective to use a branched monomer such as isopropyl vinyl ether, tert-butyl vinyl ether, and vinyl pivalate. .

The preferred combination of the component (a) and the component (b) constituting the fluorine-containing copolymer of the present invention and the monomer of the component (c) used when necessary is, for example, fluorocarbon. Olefin / alkyl vinyl ether / vinyl ether containing hydroxyl group or epoxy group, fluoroolefin / perfluoro (alkyl vinyl ether)
/ Alkyl vinyl ether / hydroxyl / epoxy group-containing vinyl ether, fluoroolefin / perfluoro (alkoxyalkyl) vinyl ether / alkyl vinyl ether / hydroxyl / epoxy group-containing vinyl ether, fluoroolefin / (perfluoroalkyl) vinyl ether / alkyl vinyl ether / hydroxyl / epoxy group-containing vinyl ether , Fluoroolefin /
(Perfluoroalkoxyalkyl) vinyl ether / alkyl vinyl ether / hydroxyl or epoxy group-containing vinyl ether, fluorine-containing (meth) acrylate / hydroxyl or epoxy group-containing (meth) acrylate, and the like.

The ratio of each monomer constituting the fluorine-containing copolymer of the present invention is as follows: Component (a): 10 to 99 mol%, preferably 15 to 97 mol%, of a monomer containing a fluorine atom. Component (b): 1 to 20 mol%, preferably 3 to 15 mol%, of a monomer containing a hydroxyl group or an epoxy group, and optionally used component (c): 0% of other monomer ~ 7
0 mol%. However, when hexafluoropropylene is used as the monomer containing a fluorine atom, and the content is less than 53% by weight, for example, perfluoro (alkyl vinyl ether) or perfluoro ( It is necessary to copolymerize a fluorine-containing monomer such as (alkoxyalkyl vinyl ether). The fluorine content in the fluorine-containing copolymer of the present invention is at least 40% by weight, preferably at least 45% by weight. When the content of the fluorine atom-containing monomer is smaller than the above range, a decrease in coating film hardness, problems such as insolubilization to an organic solvent occur, and a decrease in transparency when too large,
Problems such as a decrease in adhesion to a substrate and insolubilization in an organic solvent occur. Further, if the monomer containing a hydroxyl group or an epoxy group is smaller than the above range, the curing rate is reduced, the performance of the obtained coating film becomes insufficient, and if it is too large, gelation occurs during polymerization or storage, Problems such as the resulting coating film becoming brittle occur.

The polymerization mode for producing the fluorine-containing copolymer of the present invention may be any of emulsion, suspension, bulk or solution polymerization in the presence of a radical polymerization initiator, and may be a batch system, a semi-continuous system or a continuous system. The operation of the formula can be appropriately selected. For the production of the curable resin composition of the present invention, the fluorinated copolymer is preferably a solution, and the fluorinated copolymer preferably employs solution polymerization.

Specific examples of the radical polymerization initiator include diacyl peroxides such as acetyl peroxide and benzoyl peroxide; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; hydrogen peroxide;
Hydroperoxides such as -butyl hydroperoxide and cumene hydroperoxide; di-ter
t-butyl peroxide, dicumyl peroxide,
Dialkyl peroxides such as dilauroyl peroxide; tert-butyl peroxyacetate, te
peroxyesters such as rt-butyl peroxypivalate; azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile; ammonium persulfate;
Examples thereof include persulfates such as sodium persulfate and potassium persulfate. Further, the radical polymerization initiator includes:
If necessary, an inorganic reducing agent such as sodium hydrogen sulfite and sodium pyrosulfite, and an organic reducing agent such as cobalt naphthenate and dimethylaniline can be used in combination.

Further, as the radical polymerization initiator,
Specifically, for example, perfluoroethyl iodide, perfluoropropyl iodide, perfluorobutyl iodide, (perfluorobutyl) ethyl iodide, perfluorohexyl iodide, 2- (perfluorohexyl) ethyl iodide, par Fluoroheptyl iodide, perfluorooctyl iodide, 2- (perfluorooctyl) ethyl iodide, perfluorodecyl iodide, 2- (perfluorodecyl) ethyl iodide, heptafluoro-2-iodopropane, perfluoro-3- Methyl butyl iodide, perfluoro-5
-Methylhexyl iodide, 2- (perfluoro-5
-Methylhexyl) ethyl iodide, perfluoro-
7-methyloctyl iodide, 2- (perfluoro-
7-methyloctyl) ethyl iodide, perfluoro-9-methyldecyl iodide, 2- (perfluoro-
9-methyldecyl) ethyl iodide, 2,2,3
3-tetrafluoropropyl iodide, 1H, H, 5
H-octafluoropentyl iodide, 1H, 1H,
7H-dodecafluoroheptyl iodide, tetrafluoro-1,2-diiodoethane, octafluoro-1,4-
Examples thereof include iodine-containing fluorine compounds such as diiodobutane and dodecafluoro-1,6-diiodohexane. The iodine-containing fluorine compound can be used alone or in combination with the organic peroxide, azo compound or persulfate.

The polymerization reaction of the fluorinated copolymer is preferably carried out in a solvent system using a solvent. Specific examples of preferred organic solvents include, for example, ethyl acetate, butyl acetate, isopropyl acetate, isobutyl acetate, and the like. Esters such as cellosolve acetate; acetone, methyl ethyl ketone,
Ketones such as methyl isobutyl ketone and cyclohexanone; cyclic ethers such as tetrahydrofuran and dioxane; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; and aromatic hydrocarbons such as toluene and xylene. If necessary, alcohols, aliphatic hydrocarbons and the like can be mixed and used. The fluorinated copolymer of the present invention can be used for the curable resin composition as it is in the reaction solution in which the polymerization reaction has been performed, but there is no particular limitation on performing post-treatment after the polymerization reaction. As the post-treatment, for example, a general reprecipitation method represented by a purification method in which a polymerization reaction solution is added dropwise to a solvent for insolubilizing a fluorine-containing copolymer such as alcohol to solidify the fluorine-containing copolymer. The treatment can be performed, and then this is dissolved again in a solvent to prepare a solution of the fluorinated copolymer. Further, the residual monomer may be removed from the polymerization reaction solution after completion of the polymerization, and the resulting solution may be used as it is as a solution of the fluorine-containing copolymer. The degree of polymerization of the fluorine-containing copolymer of the present invention is 0.05 as an intrinsic viscosity measured at 25 ° C. in N, N-dimethylacetamide.
-2.0 dl / g, preferably 0.1-1.5 dl / g
It is. If the intrinsic viscosity is smaller than the above range, the mechanical strength of the obtained fluorocopolymer decreases, and if it is larger than the above range, the solution viscosity becomes high, and thin film coating becomes difficult.

<Curable fluorinated copolymer> The curable fluorinated copolymer of the present invention is obtained by adding
(B) It is obtained by reacting a compound (amino compound) containing at least a hydroxyalkylamino group or an alkoxyalkylamino group. The amino compound is an amino group capable of reacting with a hydroxyl group or an epoxy group present in the fluorinated copolymer, that is, a compound containing a hydroxyalkylamino group or an alkoxyalkylamino group, specifically, for example, a melamine-based Compounds, urea compounds, benzoguanamine compounds, glycoluril compounds and the like can be mentioned. The melamine-based compound is generally known as a compound having a skeleton in which a nitrogen atom is bonded to a triazine ring, and specific examples thereof include melamine, alkylated melamine, methylolmelamine, and alkoxylated methylmelamine. . In particular, methylolated melamine and alkoxylated methyl melamine obtained by reacting melamine and formaldehyde under basic conditions, and derivatives thereof are preferable, and alkoxylated methyl melamine is particularly preferable in terms of storage stability. The melamine-based compound preferably has two or more methylol groups and alkoxylated methyl groups per molecule. There is no particular limitation on methylolated melamine and alkosylated methylmelamine. For example, various resins obtained by a method described in Plastic Materials Course [8] Urea Melamine Resin (Nikkan Kogyo Shimbun) can be used. is there. Examples of the urea compound include, in addition to urea, a polymethylolated urea, an alkoxylated methylurea which is a derivative thereof, a methylolated uron having a urone ring having a cyclic structure, and an alkoxylated methyluron. As for the amino compound such as the urea derivative, various resins described in the above “urea-melamine resin” can be used.

The amino compound used in the production of the curable fluorinated copolymer of the present invention is particularly preferably a melamine compound from the viewpoint of compatibility with the fluorinated copolymer, and more preferably an alkoxylated methyl melamine compound from the viewpoint of reactivity. Is preferred. The amount of the amino compound to be reacted with the fluorinated copolymer is 1 to 70 parts by weight, preferably 3 to 50 parts by weight, more preferably 5 to 30 parts by weight, per 100 parts by weight of the copolymer. is there. If the amount is less than 1 part by weight, the durability as a thin film, which is a feature of the present invention, is insufficient.
If it exceeds 70 parts by weight, it is difficult to avoid gelation at the time of the addition reaction, and it is not possible to maintain the low refractive index, which is a feature of the material of the present invention, when utilizing it for optical applications.

The reaction between the fluorinated copolymer of the present invention and an amino compound can be carried out, for example, by adding the amino compound to a solution of an organic solvent in which the fluorinated copolymer has been dissolved and then homogenizing the mixture by heating and stirring for a predetermined time. Perform the reaction while The heating temperature is in the range of 30 to 150 ° C, preferably 50 to 12 ° C.
It is in the range of 0 ° C. When the heating temperature is 30 ° C. or lower, the reaction is extremely slow. When the heating temperature is 150 ° C. or higher, a cross-linking reaction due to a reaction between methylol groups or alkoxylated methyl groups in the amino compound proceeds with the reaction, resulting in formation of a gel. The progress of the reaction can be quantitatively confirmed by quantifying a methylol group or an alkoxylated methyl group by infrared spectroscopy or the like, or by weighing a weight increase after recovery by reprecipitation of a dissolved copolymer. . The reaction between the fluorine-containing copolymer and the amino compound is preferably performed in a solvent system using a solvent.
For example, the same organic solvents as those used in the production of the fluorine-containing copolymer can be used.

<Curable Resin Composition> The curable resin composition of the present invention is a solvent composition containing the curable fluorinated copolymer. In particular, the curable resin composition of the present invention is a solvent composition in which a reaction solution obtained by reacting the curable fluorinated copolymer can be used as it is, but may contain various additives as necessary. it can.

<Various Additives> The curable resin composition of the present invention has a hydroxyl group for the purpose of improving the coating properties of the curable resin composition, the properties of the coated film after curing, and imparting photosensitivity. Various polymers and monomers, coloring agents such as pigments or dyes, stabilizers such as antioxidants and ultraviolet absorbers, crosslinkable compounds,
Various additives such as a thermal acid generator, a photosensitive acid generator, a surfactant, a solvent, and a polymerization inhibitor can be contained as long as the characteristics of the material are not impaired. In particular, for the purpose of improving the hardness and durability of the coating film, it is preferable to add a thermal acid generator or a photoacid generator. In using these, it is preferable to select one that does not decrease the transparency of the curable resin composition of the present invention after curing and that is uniformly dissolved in the solution.

<Polymer and Monomer Having Hydroxyl Group> Examples of the polymer having a hydroxyl group that can be blended in the curable resin composition of the present invention include, for example, a hydroxyl group-containing copolymer such as hydroxyethyl (meth) acrylate. Examples of the polymer include a polymer obtained by copolymerizing a monomer, a resin having a phenol skeleton known as a novolak resin or a resol resin. <Colorant such as pigment or dye> Specific examples of the colorant that can be added to the curable resin composition of the present invention include extenders such as alumina white, clay, barium carbonate, and barium sulfate; Lead white, yellow lead, lead red, ultramarine, navy blue,
Inorganic pigments such as titanium oxide, zinc chromate, red iron oxide and carbon black; organic pigments such as brilliant carmine 6B, permanent red 6B, permanent red R, benzidine yellow, phthalocyanine blue and phthalocyanine green; basic dyes such as magenta and rhodamine; Direct dyes such as direct scarlet and direct orange; acidic dyes such as roselin and methanyl yellow;

<Stabilizers such as antioxidants and ultraviolet absorbers> Known antioxidants and ultraviolet absorbers that can be added to the curable resin composition of the present invention can be used. . Specific examples of the antioxidant include, for example, di-tert-butylphenol, pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-
Butyl catechol, monobenzyl ether, methylhydroquinone, amylquinone, amyloxyhydroquinone, n
-Butylphenol, phenol, hydroquinone monopropyl ether, 4,4 '-[1- [4- (1- (4-
Hydroxyphenyl) -1-methylethyl) phenyl]
Ethylidene] diphenol, 1,1,3-tris (2
5-dimethyl-4-hydroxyphenyl) -3-phenylpropane, diphenylamines, phenylenediamines, phenothiazine, mercaptobenzimidazole, and the like. Specific examples of the ultraviolet absorber include a salicylic acid-based ultraviolet absorber represented by phenyl salicylate, dihydroxybenzophenone,
Ultraviolet absorbers used for adding various plastics such as benzophenone-based ultraviolet absorbers such as hydroxy-4-methoxybenzophenone, benzotriazole-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers can be used.

<Crosslinkable Compound> In the curable resin composition of the present invention, the curable fluorinated copolymer itself contained in the composition has curability. By adding a crosslinkable compound, the curing characteristics of a coating film formed from the curable resin composition of the present invention can be improved. Examples of such a crosslinkable compound include the various amino compounds and various hydroxyl group-containing compounds such as pentaerythritol, polyphenol, and glycol. In the curable resin composition of the present invention, it is particularly preferable to mix the amino compound, particularly the alkoxyalkylmelamine compound, as a crosslinkable compound. The use ratio of the crosslinkable compound is based on 100 parts by weight of the curable fluorinated copolymer in the curable resin composition.
0 to 70 parts by weight, preferably 3 to 50 parts by weight. When the use ratio of the crosslinkable compound exceeds 70 parts by weight, the cured product is brittle, so that the film strength is reduced and the refractive index is undesirably increased.

<Thermal acid generator> As the thermal acid generator which can be blended in the curable resin composition of the present invention, the heat when the coating film of the curable resin composition of the present invention is cured by heating. The conditions can be improved to milder conditions. Specific examples of the thermal acid generator include various aliphatic sulfonic acids and salts thereof, various aliphatic carboxylic acids and salts thereof such as citric acid, acetic acid and maleic acid, and various aromatic carboxylic acids such as benzoic acid and phthalic acid. Acids and their salts, alkylbenzenesulfonic acids and their ammonium salts, various metal salts,
Examples thereof include phosphoric acid and phosphoric acid esters of organic acids. The use ratio of the thermal acid generator is 0 to 100 parts by weight of the curable fluorinated copolymer in the curable resin composition.
It is 10 parts by weight, preferably 0.1 to 5 parts by weight. If the use ratio of the thermal acid generator exceeds 10 parts by weight, the storage stability of the curable composition is poor, which is not preferable.

<Photosensitive Acid Generator> The photosensitive acid generator that can be blended in the curable resin composition of the present invention includes:
Photosensitivity is imparted to the coating film of the curable resin composition of the present invention, and the coating film of the curable resin composition can be photocured by irradiating radiation such as light. Specific examples of the photosensitive acid generator include various onium salts such as iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, ammonium salts, and pyridinium salts; β-keto esters, β-sulfonyl sulfones, and α-diazo compounds thereof. Sulfone compounds such as alkyl sulfonates, haloalkyl sulfonates, etc.
Sulfonic esters such as arylsulfonic esters and iminosulfonates; sulfonimide compounds represented by the following general formula (1)

[0027]

Embedded image

(Where X represents a divalent group such as an alkylene group, an arylene group, or an alkoxylene group, and R ¹ represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, or a halogen-substituted aryl group. A diazomethane compound represented by the following formula (2):

[0029]

Embedded image

(Here, R ² and R ³ may be the same or different and each represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, and a halogen-substituted aryl group.). Can be. The photosensitive acid generator may be used alone or in combination of two or more, and may be used in combination with the thermal acid generator. The ratio of the photosensitive acid generator to be used is 0 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the curable fluorinated copolymer in the curable resin composition. If the use ratio of the thermal acid generator is more than 20 parts by weight, the strength of the coating film is inferior and the optical transparency is undesirably reduced.

<Polymerization Inhibitor> Specific examples of the thermal polymerization inhibitor which can be blended in the curable resin composition of the present invention include, for example, pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-butylcatechol, monobenzyl ether, methylhydroquinone. , Amylquinone, amiloxyhydroquinone, n-butylphenol, phenol,
Hydroquinone monopropyl ether, 4,4 '-[1-
[4- (1- (4-hydroxyphenyl) -1-methylethyl) phenyl] ethylidene] diphenol,
1,3-tris (2,5-dimethyl-4-hydroxyphenyl) -3-phenylpropane and the like can be mentioned. The use ratio of the thermal polymerization inhibitor is preferably 5 parts by weight or less based on 100 parts by weight of the curable resin composition.

<Surfactant> The curable resin composition of the present invention may contain a surfactant for the purpose of further improving the coatability of the curable resin composition. As the surfactant, known surfactants can be used, and specifically, for example, various anionic surfactants, cationic surfactants, and nonionic surfactants can be used. In particular, in order to maintain the strength as a coating film and not to lower the optical characteristics, it is preferable to use a fluorinated surfactant. The use ratio of the surfactant is preferably 5 parts by weight or less based on 100 parts by weight of the curable resin composition.

<Solvent> Since the curable resin composition of the present invention uses a curable fluorocopolymer contained in a solution containing a solvent, it is not particularly necessary to incorporate a solvent. However, a solvent can be further added for the purpose of improving the coatability of the curable resin composition and the like. Examples of such a solvent include a solvent used in the production of a fluorinated copolymer and a solvent used in the reaction of the curable fluorinated copolymer. Even a poor solvent such as a poor solvent such as water, alcohols and ethers can be blended as long as the curable resin composition has good preservability and favorable coatability.

<Method of Forming Coating Film> The curable resin composition of the present invention can be applied to various substrates in the form of a solution, and particularly when the substrate is a transparent substrate, it has excellent antireflection properties. Can be provided. As the transparent substrate, specifically,
For example, in addition to inorganic glass, various transparent plastic plates such as a polycarbonate resin, an acrylic resin, a styryl resin, and an arylate resin, a film, and the like can be given. For application to various substrates, a known application method can be used, and in particular, various methods such as dip, coater, and printing can be applied. After application, which is a feature of the present invention,
In order to obtain optical characteristics and durability, it is particularly preferable to provide a heat history by heating. Of course, even if left at room temperature, the curing reaction proceeds sufficiently with time, and the characteristics of the material of the present invention can be obtained.However, in view of industrial productivity,
Curing by heating is effective for shortening the time, and the curing can be promoted by adding the thermal acid generator as a curing catalyst. The curing catalyst is not particularly limited, and the above-mentioned various acids and salts thereof used as a curing agent such as a general urea resin and a melamine resin are used, and an ammonium salt is particularly preferably used. The heating conditions for the curing can be appropriately selected,
Needless to say, the heating temperature is lower than the heat-resistant limit temperature of the substrate used.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below more specifically by way of examples. However, the present invention
The embodiments are not limited in any way as long as the gist is not exceeded.

[0036]

EXAMPLES In the examples, parts and% indicate parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 <Production of Fluorine-Containing Copolymer> A 1.5 L stainless steel autoclave equipped with an electromagnetic stirrer was sufficiently replaced with nitrogen gas, and then 500 g of ethyl acetate and 57.2 g of ethyl vinyl ether (EVE) were obtained. Then, 10.2 g of hydroxybutyl vinyl ether (HBVE) and 3 g of lauroyl peroxide were charged, cooled to -50 ° C with dry ice-methanol, and oxygen in the system was removed again with nitrogen gas. Next, 146 g of hexafluoropropylene (HFP) was charged,
The heating was started. The pressure when the temperature in the autoclave reached 60 ° C. was 5.3 kgf / cm ² . Then 6
The reaction was continued with stirring at 0 ° C for 20 hours, and the pressure was 1.5 kgf.
The autoclave was cooled with water when it fell to / cm ² to stop the reaction. After reaching room temperature, the unreacted monomer was released and the autoclave was opened to obtain a polymer solution having a solid concentration of 28.1%. The obtained polymer solution was poured into methanol to precipitate a polymer, followed by washing with methanol and vacuum drying at 50 ° C. to obtain 193 g of a fluorine-containing copolymer. Table 1 shows the results. The resulting polymer is obtained in N, N-dimethylacetamide in intrinsic viscosity at 25 ° C. [η], glass transition temperature (Tg) by DSC, fluorine content by alizarin complexon method, and acetylation method using acetic anhydride. Was measured respectively. Further, both NMR of ¹ H-NMR and ¹³ C-NMR
From the analysis results, the elemental analysis results, the fluorine content, and the hydroxyl value, the ratio of each monomer component constituting the fluorine-containing copolymer was determined. FIG. 1 shows an infrared chart of the polymer after drying.

<Production of curable fluorine-containing copolymer composition>
100 g of the fluorinated copolymer was dissolved in 900 g of methyl isobutyl ketone (hereinafter, referred to as "MIBK") together with 10 g of alkoxylated methyl melamine (trade name: Cymel 303, manufactured by Mitsui Cytec Co., Ltd.)
The reaction was carried out under stirring at 0 ° C. for 5 hours. After the reaction, the solution was cooled to room temperature to obtain a solution of a curable fluorine-containing copolymer. Next, the solution of the curable fluorinated copolymer after the completion of the reaction was gradually poured into a large excess of cold methanol with stirring to precipitate the curable fluorinated copolymer. Further, the obtained curable fluorinated copolymer was dissolved again in MIBK, and then reprecipitated using cold methanol. The obtained curable fluorinated copolymer was dried by vacuum drying. FIG. 2 shows an infrared chart of the curable fluorinated copolymer after drying.

<Preparation of Curable Resin Composition> 100 g of the curable fluorocopolymer and 2 g of p-toluenesulfonic acid as a curing catalyst were added to MIBK and dissolved to prepare a solution of the curable resin composition.

<Formation and Evaluation of Coating Film of Curable Resin Composition> The refractive index was measured.
Using a solution, the refractive index (n ²⁵ ) at 25 ° C. of the sample coated on a silicon wafer with a spin coater so that the thickness after drying was about 0.1 μm was measured by an ellipsometer. Measurement of Transmittance / Reflectance After using a MIBK solution of the above curable resin composition to form a coating film by a casting method, the coating was formed using a press.
C. for 1 hour to form a film having a thickness of 200 .mu.m. Using this film as a sample, a wavelength of 340-70
The transmittance at 0 nm was measured. Furthermore, JIS K540
The pencil hardness of the film was measured according to 0. Using the MIBK solution of the curable resin composition, varnish was prepared by diluting with butanol until the solid content became 4 wt%. Using this varnish, a dip coat is pulled up on a transparent polycarbonate plate having a thickness of 3 mm at a speed of 100 mm.
/ Minute, followed by heating and curing at 120 ° C. for 1 hour. The thickness of the cured coating film measured by an ellipsometer is 1
It was 140 angstroms. The total light transmittance and reflectance of the polycarbonate plate on which the cured coating film was formed were measured using a spectrophotometer with a 60 mmφ integrating sphere (U-3410 manufactured by Hitachi, Ltd.). Measurement of Adhesion As an evaluation of the adhesion of the coating film to the substrate, a scratch resistance test was performed using the polycarbonate plate on which the cured coating film was formed as a sample. Using a Kimwipe manufactured by Jujo Kimberly Co., Ltd., the coating surface was repeatedly rubbed 25 times with a load of 1 kg / cm ² , and the occurrence of scratches on the coating surface was visually confirmed. Table 5 shows the results.

<Example 2-10, Comparative Example 1-3> A fluorinated copolymer was synthesized in the same manner as in Example 1 except that the charged amounts of the respective monomers were changed to the ratios shown in Table 1. did. Table 2 shows the results. Further, except that the obtained fluorine-containing copolymer was reacted with the amino compound under the conditions shown in Table 3 in the same manner as in Example 1, the curable resin was used in the same manner as in Example 1. A fluorine copolymer was obtained. Cured films were formed from these curable fluorinated copolymers under the curing conditions shown in Table 4, and various physical properties were measured. Table 5 shows the results. <Comparative Example 4> Fluorine-containing copolymer 100 used in Example 1
g was mixed with 10 g of Cymel 303 in MIBK without a heat reaction treatment in advance to prepare a varnish.
To this was added 1 g of p-toluenesulfonic acid as a curing catalyst. The film obtained by curing this material at 120 ° C. was cloudy and had a significantly reduced light transmittance, making it unsuitable as a coating material for optical applications.

[0042]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

The abbreviations in the table indicate the following contents. (A) Component HFP: Hexafluoropropylene CTFE: Chlorotrifluoroethylene FPVE: Perfluoro (propyl vinyl ether) (b) Component HBVE: Hydroxybutyl vinyl ether GVE: Glycidyl vinyl ether (c) Component EVE: Ethyl vinyl ether iso-BVE: Isobutyl vinyl ether CH : Cyclohexyl vinyl ether E: Ethylene VAc: Vinyl acetate VPi: Vinyl pivalate VeoVa10: Vinyl versatate (amino compound) BG: Benzoguanamine GU: Glycoluril

[0044]

The cured coating film formed from the curable resin composition containing the curable fluorocopolymer of the present invention has excellent transparency, durability and low refractive index. The curable resin composition of the present invention is particularly useful for forming an optical material such as an antireflection film and an optical fiber sheath material, and also for a coating material, a weather-resistant film material, and a coating material utilizing the weather resistance which is an inherent characteristic of a fluorine material. Can be suitably used. That is, the cured coating film obtained from the curable resin composition of the present invention exhibits good thermosetting properties, and has a low refractive index of n ²⁵ = 1.40 or less and excellent transparency to visible light. Furthermore, it is excellent in adhesion to a transparent substrate, and can provide a good antireflection effect. Further, the coating film obtained from the curable resin composition of the present invention has excellent weather resistance and can be suitably used as a material for a super-weather-resistant paint.

[Brief description of the drawings]

FIG. 1 is a chart showing an infrared spectrum of a fluorinated copolymer in Example 1.

FIG. 2 is a chart showing an infrared spectrum of the curable fluorine-containing copolymer in Example 1.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masahito Mase 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd.

Claims (1)

[Claims] 1. A fluorinated copolymer obtained by polymerizing (A) at least (a) a monomer containing a fluorine atom and (b) a monomer containing a hydroxyl group or an epoxy group,
A curable resin composition comprising a curable fluorinated copolymer obtained by reacting a compound containing at least a hydroxyalkylamino group or an alkoxyalkylamino group.