JPH05209148A - Fluorine-based coating agent - Google Patents

Abstract

PURPOSE:To obtain the subject coating agent having excellent cold-curing property, giving a coating film having excellent surface-hardness, antifouling property and water-resistance and useful for paint, etc., by reacting a specific fluorine- containing copolymer with a specific silane compound, etc., and dissolving the reactional product in an organic solvent. CONSTITUTION:The objective coating agent is produced by reacting (A) a fluorine-containing copolymer containing hydroxyl group and/or carboxyl group and hydrolyzable silyl group in the molecule with (B) a silane compound of formula (R<1> is H or non-hydrolyzable group; R<2> is alkyl, aryl, alkenyl or H; (x) is 0-2) (e.g. tetramethoxysilane) and/or its partial condensate and dissolving the reactional product in an organic solvent such as ethyl acetate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorine-containing coating agent having a high surface hardness and improving the problems of conventional fluorine-containing copolymer coatings, that is, the insufficient stain resistance to water-based and oil-based stains. The coating agent of the present invention can be used in a wide range of industries including the paint industry.

[0002]

PRIOR ART AND PROBLEMS THEREOF Since fluorine-containing copolymers are excellent in chemical resistance and weather resistance, they have been extensively studied as coating resins in recent years. Among them, for example, chlorotrifluoroethylene. , A cyclohexyl vinyl ether, an alkyl vinyl ether, and a hydroxyalkyl vinyl ether to obtain a fluorine-containing copolymer (JP-A-57-34107), or chlorotrifluoroethylene, a fatty acid vinyl ester and a hydroxyl group-containing allyl ether. Paints containing a solvent-soluble fluorine-containing copolymer as a main component, such as a fluorine-containing copolymer (JP-A-60-57609), have been particularly noted. All the fluorine-containing copolymers described in the above publications have a hydroxyl group in the molecule, and can be cured at room temperature by reacting with a polyvalent isocyanate compound via the hydroxyl group, and further, it can be chlorofluoroethylene unit. Since it has a high content of about 50 mol%, a cured coating film having extremely excellent weather resistance can be obtained. However, in a room temperature curable coating material in which a polyvalent isocyanate compound is used in combination, there is a problem of toxicity of the isocyanate compound. Therefore, a room temperature curable coating material that does not use an isocyanate compound has been desired.

As a means for solving the above problems, in JP-A-62-116673, a fluorine-containing copolymer comprising a fluoroolefin, a vinyl ether and a vinyl monomer having a hydrolyzable silyl group,
In addition, a room temperature curable fluorine-based coating composition comprising a condensation reaction composition of an alkoxysilane compound and an epoxy group-containing alcohol has been proposed, but a coating film obtained by this method has excellent adhesion to a substrate but is expensive. A large amount of a vinyl monomer having a different hydrolyzable silyl group was required, and the surface hardness was not good enough. In addition, JP-A-62-1
In Japanese Patent No. 85740, a fluorine-containing copolymer having an amino group and / or a carboxyl group and a fluorine-based coating obtained by simply mixing a compound having both an epoxy group and a hydrolyzable silyl group in one molecule at room temperature is disclosed. Although proposed, a coating film obtained from the paint has problems in stain resistance and water resistance.

The inventors of the present invention have a patent for a fluorine-containing coating composition which forms a cured product which is excellent in hardness, stain resistance and weather resistance and which comprises a fluorine-containing copolymer having a hydroxyl group or a carboxyl group and an alkoxysilane compound. (Japanese Patent Application No. 2-299591), however, the coating composition is still desired to be improved in room temperature curability and water resistance.

[0005]

[Wherein R ¹ represents a non-hydrolyzable group or a hydrogen atom, and R 1
² represents an alkyl group, an aryl group, an alkenyl group or a hydrogen atom, and X represents an integer of 0-2. ]

The present invention will be described in more detail below. The fluorine-containing copolymer used in the present invention is a copolymer composed of a fluoroolefin monomer unit and another vinyl monomer unit, and has a hydroxyl group and //
Alternatively, it is a fluorine-containing copolymer having a carboxyl group and a hydrolyzable silyl group. In order to obtain such a copolymer, in addition to the fluoroolefin monomer, a hydroxyl group-containing monomer and / or a carboxyl group-containing monomer, a hydrolyzable silyl group-containing vinyl monomer, and optionally other Either copolymerize a copolymerizable monomer (hereinafter referred to as all-monomer copolymerization method) or synthesize a fluorocopolymer lacking some of the functional groups required for the fluorocopolymer of the present invention. After that, a method of introducing a necessary functional group by reacting it with a reactive compound (hereinafter referred to as polymer reaction method) and the like can be mentioned.

The polymer reaction method can be further classified as follows. In the present invention, either method may be used. (A) a copolymer obtained by copolymerizing a monomer mixture containing a fluoroolefin, a hydrolyzable silyl group-containing vinyl monomer and a hydroxyl group-containing monomer by a conventional method and a carboxylic acid anhydride; How to react. As the carboxylic acid anhydride, succinic anhydride, glutamic anhydride, itaconic anhydride, adipic anhydride, phthalic anhydride, maleic anhydride and the like can be used. (B) a copolymer obtained by copolymerizing a monomer mixture containing a fluoroolefin, a vinyl monomer containing a carboxyl group and a monomer containing a hydroxyl group (hereinafter referred to as a copolymer b), and hydrolyzable A method of reacting a hydrosilane compound having a silyl group such as triethoxysilane or trimethoxysilane. (C) A method of reacting the copolymer b with a silane compound having a carboxyl group or a hydroxyl group-reactive group and a hydrolyzable silyl group. (D) a copolymer obtained by copolymerizing a monomer mixture containing a fluoroolefin, an epoxy group-containing vinyl monomer, a carboxyl group-containing vinyl monomer and a hydroxyl group-containing monomer, and an epoxy group A method of reacting a silane compound having a reactive group and a hydrolyzable silyl group.

The hydrolyzable silyl group in the present invention includes
There is a group having a structure in which a substituent as shown below is directly bonded to a silicon atom, and the silyl group is hydrolyzed,
Generates a silanol group. Examples of the substituent that constitutes the hydrolyzable silyl group include a halogen atom; an alkoxy group such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and an n-butoxy group; a formyloxy group, an acetoxy group, a propoxy group, and the like. And an iminooxy group such as a dimethylmethoxime group, a methylethylketoxime group and a diphenylketoxime group.

Next, each monomer used in the synthesis of the fluorine-containing copolymer in the present invention will be described. Examples of the fluoroolefin include monofluoroethylene, difluoroolefin, trifluoroolefin, chlorotrifluoroethylene, tetrafluoroethylene and hexafluoropropylene, and the like, and preferably chlorotrifluoroethylene or tetrafluoroethylene.

Examples of the vinyl monomer containing a carboxyl group include α, β such as acrylic acid, methacrylic acid and crotonic acid.
-Unsaturated monocarboxylic acids; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid; monoesters of unsaturated dicarboxylic acids such as monomethyl maleate, monoethyl maleate, monomethyl fumarate, monobutyl itaconic acid; malonic acid Examples thereof include monovinyl esters of polycarboxylic acids such as monovinyl, monovinyl succinate, monovinyl phthalate, and monovinyl trimellitate. From the viewpoint of copolymerization, monovinyl esters of crotonic acid or polycarboxylic acid are preferable.

As the hydroxyl group-containing vinyl monomer, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, 3-hydroxy-2,
Hydroxyalkyl vinyl ethers such as 2-dimethylpropyl vinyl ether, 2-hydroxyethyl allyl ether, 3-hydroxypropyl allyl ether, 4
-Hydroxyalkyl allyl ethers such as hydroxyethyl allyl ether, 2-hydroxyethyl crotonic acid, hydroxyalkyl crotonic acid such as 4-hydroxybutyl crotonic acid, allyl alcohol, etc., and hydroxyalkyl crotonic acid in terms of copolymerizability. , Hydroxyalkyl vinyl ethers and hydroxyalkyl allyl ethers are preferred.

The hydrolyzable silyl group-containing vinyl monomer includes vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldiethoxysilane, vinylethyldimethoxysilane, vinyltris (β-methoxyethoxy) silane. , Vinylphenyldimethoxysilane, allyltrimethoxysilane, trimethoxyethyl vinyl ether, triethoxysilylethyl vinyl ether, methyldimethoxysilylethyl vinyl ether, trimethoxylylpropyl vinyl ether, triethoxysilylpropyl vinyl ether, methyldimethoxysilylpropyl vinyl ether, γ-acryloyloxy Propyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ
-Acryloyloxypropylmethyldimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane. Examples of the epoxy group-containing vinyl monomer include vinyl glycidyl ether and allyl glycidyl ether.

Other vinyl monomers include olefins such as ethylene and propylene; chlorinated olefins such as vinyl chloride and vinylidene chloride; methyl vinyl ether,
Alkyl vinyl ethers such as ethyl vinyl ether, propyl vinyl ether and butyl vinyl ether; cyclopentyl vinyl ether, cyclohexyl vinyl ether, cycloalkyl vinyl ethers such as cyclohexyl methyl vinyl ether, allyl ethers such as allyl glycidyl ether and allyl ethyl ether; methyl crotonate, ethyl crotonate, croton Crotonic acid alkyl esters such as propyl acid propylate; vinyl acetate, vinyl propionate, vinyl pivalate, vinyl caproate, vinyl cyclohexanecarboxylate, vinyl benzoate, vinyl cinnamate, and other carboxylic acid vinyl esters.
Preferred are alkyl vinyl ethers, cycloalkyl vinyl ethers and carboxylic acid vinyl esters.

Next, the silane compound having both a hydrolyzable silyl group and a reactive group used in (c) and (d) of the polymer reaction method will be described. Specific examples of the reactive group to be present in the silane compound include a hydroxyl group, an amino group, an isocyanate group, an epoxy group and a mercapto group, which are appropriately selected depending on the kind of the functional group contained in the copolymer to be reacted. To be selected. That is, when a carboxyl group is present on the copolymer side, an epoxy group, a silane compound having a hydroxyl group or an isocyanate group, when a hydroxyl group is present on the copolymer side, a silane compound having an epoxy group or an isocyanate group, or When an epoxy group is present on the copolymer side, a silane compound having a hydroxyl group, an amino group or a mercapto group can be used.

Specific examples of the silane compound having the above functional group include γ-hydroxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane and γ.
-Aminopropyltrimethoxysilane, triethoxysilylisocyanate and β- (3,4-epoxycyclohexyl) ethyltris (dimethyliminooxy) silane.

When the fluorine-containing copolymer is obtained by the all-monomer copolymerization method, the polymerization method may be solution polymerization or bulk polymerization, and may be carried out in the presence of a radical-generating type polymerization initiator as shown below. At a polymerization temperature of 30 to 80 ° C. and a pressure of 1
~100kg / cm ² preferably 3~10kg / cm ²
Solution polymerization carried out under the conditions of is preferable. As the radical-generating type polymerization initiator, peroxides such as diisopropyl peroxydicarbonate, t-butyl peroxypivalate, benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, azobisisovaleronitrile, etc. The oil-soluble polymerization initiators such as azo compounds, the inorganic initiators such as ammonium peroxide and potassium peroxide, and the redox initiators can be used. As the solvent used for the solution polymerization, an organic carbon hydrogen compound or a fluorine organic solvent is suitable.

The preferred composition of the fluorine-containing copolymer will be described. The preferred composition of the fluorinated copolymer in the present invention is based on the total amount of all the monomer units, the fluoroolefin monomer unit is 30 to 60 mol%, more preferably 40 to 60 mol%, and hydrolyzable. The silyl group-containing vinyl monomer unit is more preferably 3 to 40 mol%, more preferably 10 to 30 mol%, the hydroxyl group-containing vinyl monomer unit is 3 to 30 mol%,
The carboxyl group-containing monomer unit is 1 to 15 mol%, preferably 1 to 15 mol%, and the other vinyl monomer unit is 10 to 64 mol%, more preferably 10 to 46 mol%. When the amount of the fluoroolefin monomer unit is less than 30 mol%, it is difficult to obtain desired chemical resistance and weather resistance, while when it exceeds 60 mol%, the solubility in an organic solvent is lowered. When the amount of the hydrolyzable silyl group-containing vinyl monomer unit is less than 3 mol%, the adhesion to the substrate and the stain resistance cannot be obtained, while when it exceeds 40 mol%, the properties corresponding to the addition amount are improved. Is not economically disadvantageous. The hydroxyl group-containing vinyl monomer is a monomer that introduces a hydroxyl group into the copolymer, and if the amount is less than 3 mol%, the effect of addition is poor, while if it exceeds 30 mol%, the polymerization yield is increased. The rate is declining and not economical.

In the present invention, the silane compound to be reacted with the above-mentioned fluorine-containing copolymer having a hydrolyzable silyl group, that is, the silane compound for conversion is a compound represented by the following general formula (I) or a partial condensate thereof. R ¹ xSi (OR ² ) _4-X (I) [wherein R ¹ represents a non-hydrolyzable group or a hydrogen atom, and R 1
² represents an alkyl group, an aryl group, an alkenyl group or a hydrogen atom, and X represents an integer of 0-2. Examples of the non-hydrolyzable group which is the substituent R ¹ in the general formula (I) include an alkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group, an epoxyalkyl group, a mercaptoalkyl group and a methacryloxyalkyl group. , A hydroxyalkyl group and the like.

More specifically, as the alkyl group, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group and the like; Phenyl, tolyl, mesityl, etc .; alkenyl, vinyl, 1-propenyl, allyl, isopropenyl, etc .; haloalkyl, γ-chloropropyl, etc .; aminoalkyl, γ-amino Propyl group, γ- (2-aminoethyl) aminopropyl group, etc .; Epoxyalkyl group as γ-glycidoxypropyl group, β- (3,4-epoxycyclohexyl) ethyl group, etc .; Mercaptoalkyl group as γ- Mercaptopropyl group etc .; as methacryloxyalkyl group γ-methacryloxypropyl group etc .; as hydroxyalkyl group γ- hydroxypropyl group or the like; may be mentioned, respectively. Preferably, it has 8 carbon atoms.
The following, more preferably an alkyl group having 4 or less carbon atoms; an aminoalkyl group having a substituent added thereto, an epoxyalkyl group, a methacryloalkyl group and a hydroxyalkyl group; a phenyl group and an alkenyl group having 2 to 3 carbon atoms. Is. Further, the alkyl group, aryl group, and alkenyl group serving as R ² are also preferably the same groups as in the case of R ¹ , and particularly preferably an alkyl group having 4 or less carbon atoms.

Of the silane compounds represented by the above general formula (I), preferably tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, Vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) aminomethyltrimethoxysilane, It is an alkoxysilane compound such as γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and γ-hydroxypropyltrimethoxysilane. Further, in the present invention, as described above, a partial condensate of the silane compound represented by the general formula (I), for example, an oligomer such as 2 monomers or 3 monomers, may also be used as the modifying silane compound. it can. These modifying silane compounds can be selected and used according to the properties to be imparted to the copolymer, such as adhesion, hardness or flexibility.

The coating agent of the present invention is a coating agent comprising an organic solvent solution of a silane-modified polymer obtained by reacting the fluorine-containing copolymer with a modifying silane compound by the method described below. That is, the silane-modified polymer as the main component of the coating agent of the present invention can be obtained by reacting the fluorine-containing copolymer with a modifying silane compound in an organic solvent in the presence of a catalyst. Examples of the organic solvent serving as a reaction medium include ethyl acetate, butyl acetate, xylene, cellosolve, cellosolve acetate, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, and the like.

The reaction ratio between the fluorine-containing copolymer and the silane-modifying compound varies depending on the characteristics of the target silane-modified polymer, but generally the total amount of hydroxyl groups and / or carboxyl groups in the copolymer is 1 An amount by which the substituent such as an alkoxy group in the silane compound for modification is in excess of the equivalent amount, preferably 2 to 100 equivalents, and more preferably 5 to 7 equivalents.
An amount of 0 equivalents of the silane compound for modification is used. When using a modification silane compound in excess of the total amount of hydroxyl groups and / or carboxyl groups, silane compounds other than those consumed by the addition reaction to the hydroxyl groups and / or carboxyl groups are added to the reaction system as water as described below. Is added,
The side chain of the fluorocopolymer is formed by the silanol condensation reaction. When the amount of the substituent such as an alkoxy group is less than 2 equivalents, the characteristics derived from the silane component are less likely to be exhibited when the coating film is formed. On the other hand, when the amount exceeds 100 equivalents, the silane-modified polymer is hydrolyzed during coating. Therefore, the reaction between the modifying silane compounds takes precedence, and there is a possibility that two layers are separated. The preferred concentration of the fluorocopolymer in the reaction solution is 10 to 10.
40% by weight.

The catalyst used in the above reaction includes inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid; p-toluenesulfonic acid,
Organic acids such as formic acid and acetic acid; cationic inorganic ion exchangers such as hydrous antimony hydroxide; cation exchange resins; inorganic bases such as sodium hydroxide and potassium hydroxide; amines such as triethylamine and monoethylamine; ammonium chloride, Examples include amine salts such as ammonium fluoride; titanium-based compounds such as tetrabutyl totanate. Acids are preferable, and the amount thereof is 100% for the silane compound for conversion.
It is 0.05-5 parts by weight, preferably 0.1-3 parts by weight, per part by weight.

The reaction temperature is preferably 0 to 200 ° C, more preferably 20 to 150 ° C. If the reaction temperature is lower than 0 ° C, the reaction progresses very slowly, and
If the temperature exceeds 0 ° C., it becomes difficult to control the reaction and gelation may occur. The reaction time is generally 0.5 to 10 hours, preferably 40 mol% or more, more preferably 60 mol% or more of the total amount of hydroxyl groups and / or carboxyl groups in the fluorocopolymer used as a raw material. It is particularly preferable to react 80 mol% or more with the alkoxy group of the modifying silane compound.

Further, in the above reaction, a more excellent silane-modified polymer can be obtained by adding 0.1 to 4 equivalents of water to 1 equivalent of alkoxy groups of the silane compound for conversion. As a method for adding water, first, without adding water, the fluorine-containing copolymer and the silane compound for modification are reacted in a non-aqueous system at a temperature of 20 to 150 ° C. for 0.5 to 5 hours, and then a residual alkoxy group 1 The most preferable method is to add 0.1 to 4 equivalents, preferably 0.2 to 2 equivalents of water to the equivalents, and continue the reaction for 0.5 to 5 hours. In this method, a part of the amount of the modifying silane compound charged is added to the hydroxyl group and / or the carboxyl group in the fluorocopolymer by the reaction in a non-aqueous system, and most of the modifying silane compound is in an unreacted state. It exists in the reaction system. By adding water in the latter half, silanol condensation reaction of the remaining silane compound for modification occurs, and a side chain of polysiloxane is formed starting from the alkoxysilane group present in the copolymer.

Further, the following metal compound consisting of zirconium, aluminum, titanium or boron is added to the above reaction system in an amount of 0.1 to 100 parts by weight per 100 parts by weight of the silane compound for conversion.
By blending 3 parts by weight, more preferably 0.5 to 2 parts by weight, the chemical resistance, hardness, processability or curability of the resulting coating agent is further improved. If the amount of the above metal compound added exceeds 3 parts by weight, gelation tends to occur during the reaction. Zirconium-based compounds are particularly effective in improving chemical resistance and workability, titanium-based compounds are effective in improving chemical resistance, and aluminum-based compounds are effective in improving hardness and low-temperature curability, Further, the boron compound is effective in improving hardness and low temperature curability.

The following compounds can be used as the metal compound. (A) Zirconium compound: tetraethoxyzirconium, tetra-i-propoxyzirconium, tetra-
n-propoxyzirconium, tetra-n-butoxyzirconium, tetra-i-butoxyzirconium, tetra-t-butoxyzirconium, zirconium bis (acetylacetonate), zirconium tetrakis (acetylacetonate). (B) Titanium-based compound: tetramethoxy titanium, tetraethoxy titanium, tetra-i-propoxy titanium, tetra-n-propoxy titanium, tetra-n-butoxy titanium, tetra-t-butoxy titanium, diacetylacetate titanium propylate, titanium. -Tetrakis (acetylacetonate).

(C) Aluminum compound: triethoxyaluminum, tri-i-propoxyaluminum,
Tri-n-propoxy aluminum, tri-n-butoxy aluminum, tri-i-butoxy aluminum, tri-t-butoxy aluminum, diethyl acetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate). (C) Boron compound: boric acid, triethyl borate. Among the above compounds, preferred compounds are tetra-i-propoxyzirconium acetylacetonate and tetra-n.
-Propoxyzirconium acetylacetonate, tetra-n-butoxyzirconium acetylacetonate and triethyl borate.

In the present invention, the hydroxyl group or carboxyl group in the copolymer is hydrolyzed by the alkoxy group or the like in the modifying silane compound by the above reaction of the fluorine-containing copolymer and the modifying silane compound. While reacting with the silanol group, the hydrolyzable silyl group in the copolymer also reacts with the hydroxyl group, the carboxyl group or the silanol group in the silane compound for modification. The coating film thus obtained, which is formed from the silane-modified polymer in which the silane component is chemically bonded uniformly without being localized in the molecule, has uniform physical properties throughout. And the physical properties of the coating film maintain the characteristics of the fluorine-containing copolymer such as weather resistance and chemical resistance, and are excellent in room temperature curing property. Therefore, the coating film surface has high hardness, stain resistance and water resistance. Is excellent in

The organic solvent solution of the silane-modified polymer obtained by the above reaction can be used as it is as a coating agent, but if necessary, the solvent may be replaced with the following organic solvent generally used for paints. .. Suitable organic solvents for paints include, for example, aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate;
There are ketones such as acetone, methyl ethyl ketone, and cyclohexanone; cellosolves such as cellosolve acetate; and halogenated hydrocarbons such as trichloromethane and dichloroethane.

A curing catalyst for accelerating the curing rate of the coating film may be added to the fluorine-based coating composition of the present invention as required. The curing catalyst may be dibutyltin dilaurate, stannous acetate, octane. Stannous acid, 2
Carboxylic acid metal salts such as tin ethylhexanoate and cobalt naphthenate; amines such as ethylamine, dibutylamine, pyridine and morpholine; mineral acids such as hydrochloric acid and nitric acid; organic acids such as acetic acid. Preferred are alkyltin salts of carboxylic acids represented by dibutyltin dilaurate and dibutyltin dioctate. The amount of the above curing catalyst added was 0.1 parts by weight per 100 parts by weight of the silane-modified polymer.
The amount is 001 to 10 parts by weight, preferably 0.005 to 5 parts by weight. If it is less than 0.001 part by weight, the effect as a curing catalyst will not be exhibited, and if it exceeds 10 parts by weight, the storage stability will be poor.

In addition to the above curing catalyst, when the fluorine-based coating composition of the present invention is used as a paint, a pigment, a flow control agent, an ultraviolet absorber, a dispersion stabilizer, an antioxidant, etc. are added to the solution of the coating composition. Various additives described above, and other resins may be added as necessary. The fluorine-based coating composition of the present invention can be applied to a substrate with a brush, spray, roll coater or the like, and examples of the substrate to be applied include metal, wood, plastic, ceramic and glass. When the fluorine-based coating composition of the present invention applied to a substrate is dried at room temperature or under heating, a curing reaction proceeds, resulting in hardness, weather resistance, stain resistance, chemical resistance, solvent resistance and water resistance. It forms an excellent coating film.

[0033]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. [Reference Example 1]: Synthesis of fluorinated copolymer (A-1) 500 g of isopropyl alcohol (hereinafter abbreviated as IPA) and t-butyl peroxypivalate (hereinafter abbreviated as BPPV) were placed in a 1-liter autoclave equipped with a stirrer. ) 3.5
After charging g, vinyl pivalate (hereinafter abbreviated as VPV) 80.7 g, ethyl vinyl ether (hereinafter abbreviated as EVE) 22.0 g, 2-hydroxyethyl vinyl ether (hereinafter abbreviated as 2-HEVE) 27.3 g, vinyl tri Charge 49.7 g of methoxysilane (hereinafter abbreviated as VTMS).
After purging with nitrogen and degassing under reduced pressure, 151.4 g of chlorotrifluoroethylene (hereinafter abbreviated as CTFE) is introduced, and the temperature is gradually raised. After polymerization at 60 ° C for 8 hours, unreacted CT
The FE was removed and the autograve was opened to obtain a copolymer solution. The solution is dried and 281 g of copolymer (A-1)
Got The number average molecular weight of this copolymer was 8,000.

Reference Examples 2 to 5: Fluorine-containing copolymer (A
-2 to A-5) Synthesis Using the monomer mixture having the composition shown in Table 1, copolymers (A-2 to A-5) were synthesized by the same method as in Reference Example 1.

[0035]

[Table 1]

Reference Example 6: Fluorine-containing copolymer (A-
Synthesis of 6) Copolymerization was carried out in the same manner as in Reference Example 1 except that 500 g of methyl isobutyl ketone was used as a polymerization solvent in place of IPA, and 35.7 g of allyl glycidyl ether was used in place of the monomer VTMS. A solution was obtained. Next, 55.6 g of γ-aminopropyltrimethoxysilane was added to this solution and reacted at 90 ° C. for 4 hours with stirring to synthesize 306 g of a fluorocopolymer (A-6).
The number average molecular weight of the obtained copolymer (A-6) was 8500.
Met.

Reference Example 7: Fluorine-containing copolymer (A-
Synthesis of 7) Using 500 g of methyl isobutyl ketone as a polymerization solvent instead of IPA, and as a monomer, CTFE151.4 g,
VPV121.8g, EVE11.0g and 2-HEVE
Polymerization was carried out in the same manner as in Reference Example 1 using 41.0 g,
A copolymer solution was obtained. By adding 25.3 g of trimethoxysilyl isocyanate to the above solution and reacting at 70 ° C. for 3 hours with stirring, the number average molecular weight was 8300.
280 g of the copolymer (A-7) was obtained.

Reference Example 8: Fluorine-containing copolymer (A-
Synthesis of 8) 500 g of methyl isobutyl ketone was used as a polymerization solvent instead of IPA, and CTFE141.4 g was used as a monomer.
VPV60.5g, EVE33.1g, 2-HEVE41.0
g and crotonic acid 13.3 g were polymerized in the same manner as in Reference Example 1 to obtain a copolymer solution. Γ in the above solution
-Glycidoxypropyltrimethoxysilane (31.6 g) was added, and the mixture was reacted at 90 ° C for 3 hours with stirring to obtain 320 g of a copolymer (A-8).

Example 1 The above fluorine-containing copolymer (A-1) was placed in a reactor equipped with a dropping funnel, a temperature system and a stirrer.
100% 50% xylene solution, 67 parts IPA and p
-Toluenesulfonic acid 0.1 part was added, and further 10 parts of a partial condensate of tetramethoxysilane [manufactured by Tama Chemical Industry Co., Ltd., trade name: methyl silicate 51] and 2 parts of methyltrimethoxysilane were added dropwise at 70 ° C. The temperature was raised to. After reacting for 4 hours as it is, a solution prepared by diluting 3.0 parts of pure water with 20 parts of IPA is gradually added dropwise and further reacted at 70 ° C. for 6 hours,
A light yellow transparent silane modified polymer (1) was obtained. After adding 0.3 parts of dibutyltin dilaurate per 100 parts of the solution of the obtained silane-modified polymer (1) and mixing them well, the mixed solution was applied to an aluminum plate having a thickness of 0.5 mm to give a dry coating film of 20 μm. It was applied and dried at room temperature for 7 days to cure. The performance of the obtained coating film was tested for pencil hardness, solvent resistance, flex resistance, stain resistance and boiling water resistance, and the results are shown in Table 3.

The physical properties of the coating film were measured by the following measuring methods. A) Pencil hardness: JIS-K5400-8, 4, 2. (B) Solvent resistance: The coating film was observed after rubbing the surface of the coating film 20 times with absorbent cotton sufficiently soaked with methyl ethyl ketone. C) Flex resistance: JIS-K5400,8,1. Specifically, the coating film plate was bent using a bending tester, the bent portion was observed, and evaluation was made by the diameter of the mandrel that did not cause cracking or peeling of the coating film. D) Contamination resistance: The carbon black 0.1% by weight aqueous dispersion is sprayed on the coating film and then dried in a dryer at 90 ° C. for 10 minutes, which is repeated 6 times. Was washed with water and the degree of dirt on the surface of the coating film was observed. E) Boiling water resistance: After the coated plate was immersed in boiling water for 5 hours, the adhesion of the coated film to the substrate was measured by the cross cut test method.

[Examples 2 to 8] With the formulations shown in Table 2,
By the same method as in Example 1, a silane modification polymer (2 to 8) solution to which dibutyltin laurate was added was synthesized. A coating film was formed in the same manner as in Example 1, the physical properties of the obtained coating film were evaluated, and the results are shown in Table 3.

[0042]

[Table 2]

[Comparative Example 1] Fluorine-containing copolymer (A-1)
50 parts of xylene 75 parts, methyl isobutyl ketone 75
A coating film was formed in the same manner as in Example 1 by using a solution prepared by dissolving 0.3 parts of dibutyltin dilaurate in the solution, and the coating film physical properties were evaluated. The results are shown in Table 3.

[Comparative Example 2] In the method for producing the copolymer of Reference Example 1, except that VTMS was not used, the same monomers as used in the same example were used in the same proportion as in the same example, and contained. A fluorocopolymer was synthesized. 50 of the above copolymer
% Xylene solution was reacted with the modifying silane compound in the same manner as in Example 1, and thereafter, dibutyltin dilaurate was added to the obtained polymer solution in the same manner as in Example 1 to obtain a coating agent, Then, a coating film was formed.
Table 3 shows the evaluation results of the obtained coating films.

[Comparative Example 3] Fluorine-containing copolymer (A-5)
50 parts xylene 75 parts and methyl ethyl ketone 75 parts
Part, and then in the resulting solution at room temperature
-4.2 parts of glycidoxypropyltrimethoxysilane, 100 parts of tetraethoxysilane, 5.0 parts of methyltrimethoxysilane and 0.3 parts of dibutyltin dilaurate were added and mixed well. A coating test piece was prepared in the same manner as in Example 1 using the resin composition solution obtained by the above method.

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[Table 3]

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EFFECTS OF THE INVENTION According to the present invention, a fluorine-based coating composition having excellent room temperature curing property, high coating surface hardness, and excellent stain resistance and water resistance without using a highly toxic isocyanate compound. Is obtained.

Claims (1)

[Claims] 1. A fluorine-containing copolymer (A) having a hydroxyl group and / or a carboxyl group and a hydrolyzable silyl group in the molecule, a silane compound represented by the following general formula (I) and / or a portion thereof. A fluorine-based coating agent obtained by dissolving the reaction product of the condensate (B) in an organic solvent. R ¹ xSi (OR ² ) _4-X (I) [wherein R ¹ represents a non-hydrolyzable group or a hydrogen atom, and R 1
² represents an alkyl group, an aryl group, an alkenyl group or a hydrogen atom, and X represents an integer of 0-2. ]