JPH05271608A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition which has excellent storage stability and gives a coating film excellent in acid resistance and marring resistance by incorporating a specific vinyl copolymer, a functional fluororesin, and an amino resin. CONSTITUTION:This coating composition contains a thermosetting resin composition comprising 20-89wt.% vinyl copolymer, 1-50wt.% functional fluororesin, and an amino resin, the vinyl copolymer being made up of units of monomers consisting of 6-40wt.% vinyl monomer having an alkoxysilane group and represented by formula I (wherein A is a group of formula II or III; R1 is H or CH3; R2 is a 1-6C divalent saturated aliphatic group; R3 and R4 each is phenyl, a 1-6C alkyl, or a 1-10C alkoxy; R5 is a 1-10C alkyl; (m) is 0 or 1; and (n) is 1-100), 5-60wt.% hydroxylated vinyl monomer, and up to 90wt.% other copolymerizable vinyl monomer(s). This composition has excellent storage stability and can give a coating film excellent in acid resistance and marring resistance. It is particularly suited for use as an automotive topcoating composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel coating composition which is capable of forming a coating film having excellent acid resistance, scratch resistance, stain resistance and water repellency, and is particularly suitable as a top coating composition for automobiles.

[0002]

BACKGROUND OF THE INVENTION Acrylic resin / melamine resin and polyester resin /
Paints containing melamine resin as a cured resin component are widely used because they can be used as a one-pack type and form a coating film excellent in weather resistance, solvent resistance and finished appearance, but have become a social problem in recent years. There is an inherent problem that the coating film surface is deteriorated by the acid rain (pH = 5 or less) and the coating film appearance is deteriorated. Also, in addition to the above, these coatings, scratches are likely to stand out when washed in a car wash machine,
There is also a problem that the coating film is easily soiled due to the adherence of bird droppings, dirt, and the like to the body.

[0003]

[Means for Solving the Problems] The present inventors have made it possible to maintain the finished appearance, weather resistance, physical performance, etc. of a coating film,
In order to develop a top-coat paint that forms a coating film with dramatically improved acid resistance, scratch resistance, stain resistance and water repellency, earnest research was conducted.

As a result, a coating composition containing a curable resin composition prepared by mixing an alkoxysilane group-containing vinyl copolymer, a functional group-containing fluororesin and an amino resin in a specific ratio is resistant to acid and The present invention has been completed by finding that it provides a coating film excellent in scratch resistance, stain resistance and water repellency.

That is, the present invention provides the following components (A) to (C) (A) general formula (1)

[0006]

[Chemical 3]

(Where A is

[0008]

[Chemical 4]

R ₁ is a hydrogen atom or a methyl group, and R ₂
Is a divalent saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, R ₃
And R ₄ are the same or different and each is a phenyl group having 1 to 6 carbon atoms.
An alkyl group or an alkoxyl group having 1 to 10 carbon atoms,
R ₅ represents an alkyl group having 1 to 10 carbon atoms. m
Represents 0 or 1, and n represents an integer of 1 to 100. 5 to 40% by weight of a vinyl monomer containing an alkoxysilane group, 5 to 60% by weight of a vinyl monomer containing a hydroxyl group, and 90% by weight or less of another copolymerizable vinyl monomer, which is a compound represented by 20 to 89% by weight of a vinyl-based copolymer composed of (B) 1 to 50% by weight of a fluorine-based resin having a functional group and (C) an amino resin of 10 to 50% by weight. It relates to the coating composition containing it.

The coating composition of the present invention will be described in detail below.

The vinyl-based copolymer (A) used in the coating composition of the present invention is

[0012]

[Chemical 5]

(Where A is

[0014]

[Chemical 6]

R ₁ is a hydrogen atom or a methyl group, R ₂
Is a divalent saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, R ₃
And R ₄ are the same or different and each is a phenyl group having 1 to 6 carbon atoms.
Is an alkyl group or an alkoxy group having 1 to 10 carbon atoms,
₅ represents an alkyl group having 1 to 10 carbon atoms. m represents 0 or 1, and n represents an integer of 1 to 100. 5 to 40% by weight of a vinyl monomer containing an alkoxysilane group, which is a compound represented by the formula
50% by weight and other copolymerizable vinyl monomers 0
It is a vinyl-based copolymer containing 90 to 90% by weight.

In the compound of the general formula (1) which is an essential monomer in the vinyl copolymer, n is preferably 1-10.

In the general formula (1), the divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms represented by R ₂ is a linear or branched alkylene group such as methylene, ethylene, propylene, 1 , 2-butylene, 1,3-butylene, 2,3-butylene, tetramethylene, ethylethylene, pentamethylene, hexamethylene group and the like. Examples of the alkyl group having 1 to 6 carbon atoms represented by R ₃ and R ₄ include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert. -Butyl, n-pentyl, isopentyl, neopentyl, n-
Hexyl, isohexyl groups and the like can be mentioned, and R ₅
In addition to these, examples of the alkyl group having 1 to 10 carbon atoms represented by are n-heptyl, 1-methylpentyl, 2-methylhexyl, n-octyl, n-mannyl, n-decyl and the like. As the alkoxy group having 1 to 10 carbon atoms represented by R ₃ and R ₄ , a linear or branched alkoxy group such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, s
Examples include ec-butoxy, tert-butoxy, n-pentoxy, isopentoxy, n-hexyloxy, isohexyloxy, n-octyloxy and the like. Further, in the general formula (1), when n is 2 or more,
R ₃ and R ₄ may be the same or different.

Among the compounds of the general formula (1) in the present invention, those in which m is 0 include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane and the like.

Among the compounds of the general formula (1) in the present invention, m is 1 and A is

[0020]

[Chemical 7]

Examples of γ- (meta) include
Acryloxyethyltrimethoxysilane, γ- (meth)
Acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ-
(Meth) acryloxypropyltripropoxysilane,
γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropylmethyldipropoxysilane, γ- (meth) acryloxybutylphenyldimethoxysilane, γ- (meth) acryloxybutylphenyldiethoxysilane, γ- (meth) acryloxybutylphenyldipropoxysilane, γ- (meth) acryloxypropyldimethylmethoxysilane, γ
-(Meth) acryloxypropyldimethylethoxysilane, γ- (meth) acryloxypropylphenylmethylmethoxysilane, γ- (meth) acryloxypropylphenylmethylethoxysilane,

[0022]

[Chemical 8]

The following can be mentioned.

In the compound of the general formula (1), m is 1
So A

[0025]

[Chemical 9]

And the like.

Among these compounds of the general formula (1), especially acryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropyltri-n-butoxysilane, acryloxypropylmethyldimethoxysilane, methacryloxy. Propylmethyldimethoxysilane, methacryloxypropylmethyldi-n-butoxysilane and the like are preferable.

In the copolymer, the vinyl monomer having a hydroxyl group which is another essential component is, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl (meth) acrylate, butanediol. Monoacrylate, (poly) ethylene glycol-modified monoacrylate, (poly) propylene glycol-modified monoacrylate, "Plaxel FM-1",
"Plaxel FM-2", "Plaxel FM-3",
"Plaxel FA-1", "Plaxel FA-2",
"Plaxel FA-3" (both are Daicel Chemical Industries, Ltd.)
Made, product name, caprolactone-modified (meth) acrylic acid 2
-Hydroxyethyls) and the like, but are not limited to these.

As the vinyl monomer copolymerizable with the above-mentioned alkoxysilane group-containing vinyl monomer and hydroxyl group-containing vinyl monomer, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, Propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate,
Stearyl methacrylate, cyclohexyl acrylate,
Esters of acrylic acid or methacrylic acid such as cyclohexyl methacrylate with a monohydric alcohol having 1 to 22 carbon atoms; carboxyl group-containing vinyl monomers such as acrylic acid, methacrylic acid, maleic anhydride, glycidyl acrylate, glycidyl methacrylate, etc. Glycidyl group-containing vinyl monomer; acrylamide, methacrylamide, N-
Amide vinyl monomers such as methylol acrylamide and N-methylol methacrylamide; amine vinyl monomers such as dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate and tert-butylaminoethyl methacrylate; styrene, vinyltoluene, acrylonitrile, methacrylonitrile. , Other vinyl monomers such as α-methylstyrene, vinyl acetate:
And a compound having one polymerizable unsaturated bond in one molecule.

The copolymerization amount of the vinyl monomer containing an alkoxysilane group is 5 to 40% by weight, preferably 5 to 30%.
% By weight. If it is less than 5% by weight, the acid resistance will decrease,
If it exceeds 40% by weight, problems such as deterioration in storage stability of the coating material occur. The copolymerization amount of the hydroxyl group-containing vinyl monomer is 5 to 60% by weight, preferably 10 to 40% by weight. If it is less than 5% by weight, the reaction between the amino resin, the alkoxysilane group and the hydroxyl group does not proceed sufficiently and the curability,
If the acid resistance decreases, and the content exceeds 60% by weight, problems such as impaired water resistance occur. Further, other copolymerizable vinyl-based monomer is 90% by weight or less, preferably 30 to
It can be blended at 85% by weight.

The copolymerization reaction of the alkoxysilane group-containing vinyl-based monomer, the hydroxyl group-containing vinyl-based monomer, and the other vinyl-based monomer is carried out in the same manner as a usual method for synthesizing an acrylic resin or vinyl resin. It can be carried out, for example, by dissolving or dispersing both components in an organic solvent and heating in the presence of a radical polymerization initiator at a temperature of about 60 to 180 ° C. with stirring. The reaction time may be usually about 1 to 10 hours.

As the organic solvent, heptane,
Hydrocarbon solvents such as toluene, xylene, octane, mineral spirits, ester solvents such as ethyl acetate, n-butyl acetate, isobutyl acetate, methyl cellosolve acetate, butyl carbitol acetate, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, etc. Ketone solvent, ethanol, isopropanol, n
-Alcohol solvents such as butanol, sec-butanol and isobutanol, ether solvents such as n-butyl ether, dioxane, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether can be used. Of these, when a hydrocarbon solvent is used, it is preferable to use another solvent in combination from the viewpoint of solubility.

As the radical initiator, any of those usually used can be used, and examples thereof include benzoyl peroxide and t-butylperoxy-2-.
Examples thereof include peroxides such as ethylhexanoate and azo compounds such as azoisobutyronitrile and azobisdimethylvaleronitrile.

The number average molecular weight of the acrylic polymer is usually about 3,000 to 500,000, preferably 5,000 to 1
It is about 00000.

As described above, the vinyl copolymer which is the component (A) in the present invention is a compound represented by the general formula (1), which is a vinyl monomer having an alkoxysilane group and a vinyl monomer having a hydroxyl group. It is obtained by copolymerizing a monomer and another vinyl-based monomer, and an alkoxysilane group and a hydroxyl group are bonded to the vinyl-based copolymer as a side chain. Therefore, as compared with the acrylic resin, which is a conventional amino resin-curing base resin, the vinyl-based copolymer has a chemical bond that is less susceptible to hydrolysis —SiOSi—, SiO.
Since it has an alkoxysilane group capable of introducing C- at the cross-linking point, when the vinyl copolymer is used as a base resin for an amino resin curing system, the cured coating film has extremely excellent surface properties (acid resistance, Water repellency, scratch resistance, water resistance, chemical resistance, weather resistance, heat resistance), and particularly excellent acid resistance.

In the present invention, the vinyl copolymer may be used in combination with a hydroxyl group-containing resin such as acrylic polyol or polyester polyol and / or another alkoxysilane group-containing resin.

The fluorine-based resin (B) used in the coating composition of the present invention has a functional group (alkoxysilane group and hydroxyl group) in the vinyl copolymer or a functional group (amino group) in the amino resin in the molecule. It is a resin having a fluorine atom and a functional group (for example, a hydroxyl group, a carboxyl group, a hydroxyl group / carboxyl group, an isocyanate group, etc.) that reacts with an N-methylol group, an N-alkoxyl group, and the like.

Typical examples of the fluorine-based resin (B) are shown below.

[Hydroxyl group-containing resin] Typical examples of the resin include a hydroxyl group-containing polymerizable unsaturated monomer (a), a fluorine-containing polymerizable unsaturated monomer (b) and, if necessary, other polymerizable compounds. Examples thereof include polymers having an unsaturated monomer (c) as a monomer component.

Hydroxyl group-containing polymerizable unsaturated monomer (a): 1
It is a monomer having a radically polymerizable unsaturated group and a hydroxyl group in the molecule.

In addition to the above hydroxyl group-containing vinyl monomer, the following compounds can be used.

Typical examples are the compounds represented by the following general formulas (2) and (3).

General formula (2)

[0044]

[Chemical 10]

In the formula, R ₆ represents a hydrogen atom or a hydroxyalkyl group.

General formula (3)

[0047]

[Chemical 11]

Examples of the monomer component of the general formula (2) include CH ₂ ═CHOH, CH ₂ ═CHOC ₄ H ₈ OH and the like.

Examples of the monomer component of the general formula (3) include

[0050]

[Chemical 12]

And the like.

In addition to the above, an adduct of the unsaturated group-containing monomer represented by the general formulas (2) and (3) with lactones such as ε-caprolactone and γ-valerolactone is used. it can.

Fluorine-containing polymerizable unsaturated monomer (b): 1
It is a monomer containing a radically polymerizable unsaturated group and a fluorine atom in the molecule.

Typical examples are the compounds represented by the following general formulas (4) and (5).

General formula (4) CX ₂ = CX ₂ (4) In the formula, X is the same or different and is H, Cl, Br, F,
An alkyl group or a haloalkyl group is shown. However, at least one F is contained in the formula.

General formula (5)

[0057]

[Chemical 13]

In the formula, Z has the same meaning as described above and R ₇
Represents a fluoroalkyl group, and p represents an integer of 1 to 10.

The "alkyl group" in the general formula (4) is C
_1-6 pieces, preferably C _1-4 pieces. In particular,
Examples thereof include methyl, ethyl, propyl, isopropyl, butyl and pentyl groups. The "haloalkyl group" is C _1-6 , preferably C _1-4 . Specifically, for example, CHF ₂ , CH ₂ F, CCl ₃ , CH · Cl ₂ , CH ₂
Cl, CH ₂ Cl, CFCl ₂ , (CF ₂ ) ₂ CF ₃ ,
(CF ₂ ) ₃ CF ₃ , CF ₂ CH ₃ , CF ₂ CHF ₂ ,
CF ₂ Br, CH ₂ Br, can be mentioned CF ₃ and the like.

Examples of the monomer represented by the general formula (4) include CF ₂ = CF ₂ , CHF = CF ₂ , CH ₂ = CF ₂ , C
H ₂ = CHF, CClF = CF ₂ , CHCl = CF ₂ ,
CCl ₂ = CF ₂ , CClF = CClF, CHF = CC
l ₂ , CH ₂ = CClF, CCl ₂ = CC1F, CF ₃
CF = CF ₂ , CF ₃ CF = CHF, CF ₃ CH = CF
₂ , CF ₃ CF = CH ₂ , CH ₃ CF = CF ₂ , CHF
₂ CF = CHF, CH ₃ CF = CH ₂ , CF ₂ ClCF
= CF ₂ , CF ₃ CCl = CF ₂ , CF ₃ CF = CFC
1, CF ₂ ClCCl = CF ₂ , CF ₂ ClCF = CF
Cl, CFCl ₂ CF = CF ₂ , CF ₂ CCl = CCl
F, CF ₃ CCl = CCl ₂ , CClF ₂ CF = CCl
₂ , CCl ₃ CF = CF ₂ , CF ₂ ClCCl = CCl
₂ , CFCl ₂ CCl = CCl ₂ , CF ₃ CF = CHC
1, CClF ₂ CF = CHCl, CF ₃ CCl = CHC
1, CHF ₂ CCl = CCl ₂ , CF ₂ ClCH = CC
l ₂ , CF ₂ ClCCl = CHCl, CCl ₃ CF = C
HCl, CF ₂ lCF = CF ₂ , CF ₂ BrCH = CF
₂ , CF ₃ CBr = CHBr, CF ₂ ClCBr = CH
₂ , CH ₂ BrCF = CCl ₂ , CF ₃ CBr = C
H ₂ , CF ₂ CH = CHBr, CF ₂ BrCH = CH
F, CF ₂ BrCF = CF ₂ , CF ₃ CF ₂ CF = CF
₂ , CF ₃ CF = CFCF ₃ , CF ₃ CH = CFC
F ₃ , CF ₂ = CFCF ₂ CHF ₂ , CF ₃ CF ₂ CF
= CH ₂ , CF ₃ CH = CHCF ₃ , CF ₂ = CFCF
₂ CH ₃ , CF ₂ = CFCH ₂ CH ₃ , CF ₃ CH ₂ C
H = CH ₂ , CF ₃ CH = CHCH ₃ , CF ₂ = CHC
H ₂ CH ₃ , CH ₃ CF ₂ CH = CH ₂ , CFH ₂ CH
_{= CHCFH 2, CH 3 CF 2} CH = CH 3, CH 2 =
CFCH ₂ CH ₃ , CF ₃ (CF ₂ ) ₂ CF = CF ₂ ,
CF ₃ (CF ₂₎ can be cited ₃ CF = CF _2, and the like.

The "fluoroalkyl group" in the general formula (5) is a C _3-21 group. Specifically, for example, C _{4
F 9, (CF 2) 6} CF (CF 3) 2, C 8 F 17, C 10
F _{21 and the} like can be mentioned.

Examples of the monomer represented by the general formula (5) include:

[0063]

[Chemical 14]

And the like.

The above-mentioned monomers can be used alone or in combination of two or more.

When the monomer represented by the general formula (4) is used, a coating film having particularly excellent acid resistance and weather resistance is formed, and when the monomer represented by the general formula (5) is used, it is particularly repellent. A coating film having excellent water-based property can be formed.

Other polymerizable unsaturated monomer (c): A conventionally known monomer containing a radically polymerizable unsaturated group can be appropriately used according to the required performance.

The following (c-1) to (c-6) can be mentioned as typical examples.

(C-1) Olefin-based compound: For example, ethylene, propylene, butylene, isoprene, chloroprene and the like.

(C-2) Vinyl ether and allyl ether: For example, ethyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, butyl vinyl ether, tert-butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether, isohexyl vinyl ether, octyl vinyl ether, 4-methyl-1-. Chain alkyl vinyl ethers such as pentyl vinyl ether, cycloalkyl vinyl ethers such as cyclopentyl vinyl ether and cyclohexyl vinyl ether, aryl vinyl ethers such as phenyl vinyl ether, o-, m-, p-trivinyl ether, aralkyl vinyl ethers such as benzyl vinyl ether and phenethyl vinyl ether. Kind etc.

(C-3) Vinyl ester and propenyl ester: For example, vinyl acetate, vinyl lactate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl isocaproate, vinyl pivalate, vinyl caprate, etc. and isoacetate. Propenyl propionate such as isopropenyl propionate.

(C-4) Ester of acrylic acid or methacrylic acid: for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate, Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, lauryl methacrylate, etc. Acrylic acid or C1-18 alkyl ester of methacrylic acid: Acrylic acid Carbon number 2 of acrylic acid or methacrylic acid such as methoxybutyl, methoxybutyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxybutyl acrylate, ethoxybutyl methacrylate. Alkoxyalkyl esters of 8.

(C-5) Vinyl aromatic compound: For example,
Styrene, α-methylstyrene, vinyltoluene, p-
Chlorstyrene, etc.

(C-6) Others: Acrylonitrile, methacrylonitrile, etc.

[Carboxyl Group-Containing Resin] Typical examples of the resin include a carboxyl group-containing polymerizable unsaturated monomer (d), a fluorine-containing polymerizable unsaturated monomer (b) and, if necessary, other A copolymer containing the polymerizable unsaturated monomer (c) as a monomer component can be mentioned.

Carboxyl group-containing polymerizable unsaturated monomer (d): A monomer containing a radical polymerizable unsaturated group and a carboxyl group in one molecule.

Typical examples are the compounds represented by the following general formulas (6) and (7).

General formula (6)

[0079]

[Chemical 15]

In the formula, R ₈ represents a hydrogen atom or a lower alkyl group, R ₉ represents a hydrogen atom, a lower alkyl group or a carboxylyl group, and R ₁₀ represents a hydrogen atom, a lower alkyl group or a carboxy lower alkyl group. ..

General formula (7)

[0082]

[Chemical 16]

In the formula, R ₁₁ represents a hydrogen atom or a methyl group, and p represents an integer of 1-10.

In the above formula (6), the lower alkyl group is preferably a C ₄ or less, particularly a methyl group.

Examples of the general formula (6) include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid and the like.

Examples of the general formula (7) include 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 5-carboxypentyl (meth) acrylate and the like.

In addition to the above, 1 mol of a polymerizable unsaturated monomer having a hydroxyl group (a) and 1 mol of a polycarboxylic acid anhydride compound (eg, maleic anhydride, itaconic anhydride, succinic anhydride, phthalic anhydride, etc.) An addition product with can also be used.

[Carboxyl Group- and Hydroxyl Group-Containing Resin] Typical examples of the resin include a hydroxyl group-containing polymerizable unsaturated monomer (a), a carboxyl group-containing polymerizable unsaturated monomer (d), and a fluorine-containing polymer. Examples of the copolymer include a polymerizable unsaturated monomer (b) and, if necessary, another polymerizable unsaturated monomer (c) as a monomer component.

[Isocyanate Group-Containing Resin] Typical examples of the resin include isocyanate group-containing polymerizable unsaturated monomer (e), fluorine-containing polymerizable unsaturated monomer (b) and, if necessary, other components. A copolymer containing the polymerizable unsaturated monomer (c) as a monomer component can be mentioned.

Isocyanate group-containing polymerizable unsaturated monomer (e): A monomer containing a radically polymerizable unsaturated group and an isocyanate group in one molecule.

Typical examples are the monomers represented by the following general formulas (8) and (9).

General formula (8)

[0093]

[Chemical 17]

In the formula, R ₁₁ and p have the same meanings as described above, and examples thereof include a monomer represented by the formula: isocyanate ethyl (meth) acrylate.

General formula (9)

[0096]

[Chemical 18]

In the formula, R ₁₁ and p have the above-mentioned meanings, and R ₁₂ is a hydrogen atom or an alkyl group having ₅ or less carbon atoms,
Examples of the monomer include, for example, α, α-dimethyl-m-isopropenylbenzyl isocyanate.

In addition to the above, a reaction product of 1 mol of the hydroxyl group-containing polymerizable unsaturated monomer (b) and 1 mol of the polyisocyanate compound can be used. Examples of the polyisocyanate compound include toluene diisocyanate,
1,6-hexamethylene diisocyanate, 4,4'-
Diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, biphenylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, dicyclohexylmethane,
4,4'-diisocyanate, P-xylene diisocyanate, m-xylene diisocyanate, bis (4-isocyanate phenyl) sulfone, isopropylidene bis (4-phenyl isocyanate), lysine isocyanate, isophorone diisocyanate and polymers and burettes thereof Etc. can be mentioned.

Further, as the isocyanate group-containing resin,
In addition to the above, those obtained by reacting the hydroxyl group-containing resin with the above polyisocyanate compound can also be used.

In the coating composition of the present invention, the fluorine content is about 1 to 70% by weight, preferably about 5 to 60% by weight, based on the fluorine-containing polymerizable unsaturated monomer (b) as a monomer component. Can have a range of. If the content is less than the above range, scratch resistance, stain resistance, weather resistance, a coating film inferior in acid resistance, on the other hand, if the content exceeds the above range, the cost of the coating composition increases, which is not practical, and is also manufactured. However, this is not preferable because it also has drawbacks.

In the coating composition of the present invention, when the monomer represented by the general formula (4) is used as the fluorine-containing polymerizable unsaturated monomer (b), the polymer formed from this monomer is mainly Since it has a structure in which a fluorine atom is bonded to the chain, it exerts excellent effects on weather resistance, acid resistance, etc. Further, when the monomer represented by the general formula (5) is used, the fluorine atom bonded to the side chain is It exhibits excellent effects such as water repellency and stain resistance.

In the coating composition of the present invention, the above-mentioned fluororesin (B) may be modified with another resin (for example, vinyl resin, polyester resin, urethane resin, silicone resin, etc.).

The amino resin (C) used in the coating composition of the present invention includes melamine, urea, benzoguanamine,
Examples thereof include known partially or completely methylolated amino resins obtained by the reaction of an aldehyde with an amino component such as acetoguanamine, steroguanamine, spiroguanamine, dicyandiamide and the like. Examples of the aldehyde include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like. Further, an etherified product of this methylolated amino resin can be used, and examples of the alcohol used for etherification include methyl alcohol, ethyl alcohol,
n-propyl alcohol, i-propyl alcohol, n
-Butyl alcohol, i-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol and the like can be mentioned. In the present invention, it is particularly preferable to use hexamethoxymethylmelamine or an etherified melamine resin obtained by substituting a part or all of the methoxy group thereof with a C ₄ or more alcohol.

In the present invention, as the component (C), trade names such as Cymel 303 (full methoxylated melamine resin, manufactured by Mitsui Cyanamide Co., Ltd.) and Uban 20SE-60 (butylated melamine resin, manufactured by Mitsui Toatsu Co., Ltd.) are used. A commercially available amino resin can be used.

The coating composition of the present invention comprises the above (A) to (C).
The component is contained as a curable resin composition component, and the blending ratio of the components of these components can be arbitrarily selected according to the purpose, but based on the total solid content of the components (A) to (C),
Component (A) 20-89% by weight, preferably 30-80% by weight, Component (B) 1-50% by weight, preferably 10-4.
0% by weight and 10 to 50% by weight of the component (C), preferably 10 to 30% by weight. (A) component is 2
When it is less than 0% by weight, acid resistance, water repellency, scratch resistance and the like are deteriorated, while when it is more than 89% by weight, the crosslink density of the coating film is insufficient and solvent resistance and the like are poor. If the content of the component (B) is less than 1% by weight, the acid resistance, water repellency, stain resistance and the like are poor, while if it exceeds 50% by weight, the cost is high and it is not practical. When the amount of the component (C) is less than 10% by weight, the cross-linking density of the coating film becomes insufficient and the solvent resistance, scratch resistance, stain resistance, etc. are poor, while when it exceeds 50% by weight, acid resistance, etc. Is reduced.

In the coating composition of the present invention, it is preferable to further use a curing accelerating catalyst of an alkoxysilane group, if necessary. For example, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, trichloroacetic acid, phosphoric acid, mono-n-
Propyl phosphoric acid, monoisopropyl phosphoric acid, mono-n-butyl phosphoric acid, monoisobutyl phosphoric acid, mono-tert-butyl phosphoric acid, monooctyl phosphoric acid, monodecyl phosphoric acid, and other monoalkyl phosphoric acids, di-n-propyl phosphoric acid, diisopropyl phosphoric acid, di-n -Butyl phosphoric acid, diisobutyl phosphoric acid, di-te
Dialkyl phosphoric acid such as rt-butyl phosphoric acid, dioctyl phosphoric acid and didecyl phosphoric acid, phosphoric acid ester of β-hydroxyethyl (meth) acrylate, mono-n-propyl phosphorous acid, monoisopropyl phosphorous acid, mono-n-butyl phosphorous acid, monoisobutyl Monoalkyl phosphites such as phosphorous acid, mono-tert-butyl phosphite, monooctyl phosphite, monodecyl phosphite, di-n-propyl phosphite, diisopropyl phosphite, di-n-butyl phosphite, diisobutyl phosphite, The-
Acid compounds such as tert-butyl phosphite, dioctyl phosphite, didecyl phosphite and the like; dialkyl phosphites and the like; tetraisopropyl titanate, tetrabutyl titanate, tin octylate, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin. Tin-containing compounds such as dimalate; basic compounds such as butylamine, tert-butylamine, dibutylamine, hexylamine, ethylenediamine, triethylamine, isophoronediamine, imidazole, lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methylate. It is possible to use at least one of these.

What is particularly interesting about this curing catalyst is that in the amino resin of the component (C), hexamethoxymethylmelamine and part or all of its methoxy groups are converted into C ₄
When using an etherified melamine resin substituted with the above alcohol, it is common to use a strong acid catalyst such as paratoluenesulfonic acid, dodecylbenzenesulfonic acid, etc. as a curing catalyst with a hydroxyl group, and the strong acid catalyst is ,
Triethylamine, diethanolamine, 2-amino-
It is used by imparting storage stability as a one-pack type paint by neutralizing (blocking) it with an amine compound such as 2-methylpropanol. This neutralizing (blocking) strong acid catalyst cures the alkoxysilane group. It is also a catalyst. In other words, the neutralization (block) strong acid catalyst is 100
It means that it becomes a common catalyst for the reaction of the resin and the reaction of the alkoxysilane at the baking temperature of ℃ or more. More interestingly, this neutralizing (blocking) strong acid catalyst does not function as a curing catalyst for alkoxysilanes at room temperature, so that it can be stored in a one-liquid storage state under release which is generally impossible in an alkoxysilane curing system. Also made possible.

The coating composition of the present invention can be used as a clear coating, a solid color coating, a metallic coating or the like, if necessary, by adding various known additives.

The coating composition of the present invention contains, if necessary, an organic and / or inorganic thixotropic agent; organic ultrafine particles obtained by a non-aqueous polymer dispersion, an emulsion polymerization method or the like; A regulator, an ultraviolet absorber, a light stabilizer and the like can be contained.

As the solvent, all the solvents used in the conventional acrylic resin / melamine resin-based paint can be used. For example, toluene, xylene, methyl ethyl ketone,
Organic solvents such as ethyl acetate, dioxane and butanol can be mentioned. These solvents can be used alone or in an appropriate mixture.

The coating composition of the present invention can be used in the form of being dissolved or dispersed in an organic solvent.

The coating composition of the present invention can be applied by, for example, electrostatic coating, air spray coating, etc., and a conventionally used coating machine, coating equipment or the like can be used as it is. The viscosity may be appropriately selected depending on the coating machine, the type of solvent, the coating conditions and the like.

[0113]

EFFECTS OF THE INVENTION The coating composition of the present invention is excellent in acid resistance, scratch resistance, stain resistance, water resistance, weather resistance and the like without impairing the appearance of the coating film, and these effects are long-term. A lasting coating can be obtained. Therefore, the coating composition of the present invention is suitable as a top coating composition for automobiles.

[0114]

EXAMPLES Hereinafter, production examples, examples and comparative examples will be described.
The present invention will be described more specifically. In each example, parts and% are based on weight.

I. (A) Production Example of Acrylic Polymer (A-1) Styrene 100 parts n-butyl acrylate 450 parts 2-ethylhexyl methacrylate 200 parts 2-hydroxyethyl methacrylate 150 parts γ-methacryloxypropyltrimethoxysilane 100 parts azobisiso A mixture of 20 parts of butyronitrile was added to 11 parts of xylene in the same amount as the mixture.
The mixture was added dropwise at 0 ° C. over 3 hours and aged at the same temperature for 2 hours. The obtained polymer is transparent and has an average molecular weight (GP
C, the following has the same meaning. ) Was 20000.

(A-2) Methyl methacrylate 150 parts n-butyl methacrylate 500 parts 1,4-butanediol monoacrylate 200 parts γ-methacryloxypropyltrimethoxysilane 150 parts Azobisisobutyronitrile 20 parts Xylene 500 parts, n-butanol 5
The mixture was added dropwise to 00 parts of the mixed solvent at 120 ° C. for 3 hours and then aged at the same temperature for 2 hours. The obtained polymer was transparent and had an average molecular weight of 18,000.

(A-3) Styrene 100 parts n-Butyl acrylate 600 parts 2-Hydroxyethyl methacrylate 300 parts Azobisisobutyronitrile 20 parts A mixture consisting of 20 parts is dropped into the same amount of xylene at 120 ° C. for 3 hours. Then, it was aged at the same temperature for 2 hours. The obtained polymer was transparent and had an average molecular weight of 18,000.

II. Production Example of Fluorine-Based Resin Having Functional Group (B-1) Hydroxyl Group-Containing Fluorine Resin In a stainless steel autoclave with a stirrer having a capacity of 400 ml, n-butyl methacrylate 10 parts 2-hydroxyethyl acrylate 25 parts vinyl acetate 10 parts vinyl butyrate 15 parts Methyl isobutyl ketone 200 parts Azobisisobutyronitrile 2 parts Sodium borate 0.5 parts are charged, and after nitrogen substitution, cooling and solidification, and deaeration, 40 parts of monochlorotrifluoroethylene 40 parts are introduced into the autoclave, and then inside the autoclave. Warm 6
The temperature was gradually raised until it reached 0 ° C. After that, the reaction was continued under stirring for 16 hours or more, and the internal pressure of the autoclave was 1 kg.
When the temperature dropped to less than / cm ² , the autoclave was water-cooled to stop the reaction. The obtained resin solution was poured into excess heptane to precipitate the resin, which was then washed and dried to obtain 85 parts of resin.

The average molecular weight was 7,000. The obtained resin was dissolved in the same amount of xylene to obtain a resin solution having a nonvolatile content of 50%.

(B-2) Hydroxyl group- and carboxyl group-containing fluororesin n-butyl acrylate 10 parts vinyl acetic acid 5 parts 1,4 butanediol monoacrylate 30 parts vinyl acetate 10 parts vinyl butyrate 10 parts sodium borate 0.5 parts 1 Chlorofluorotrifluoroethylene 35 parts Production was carried out in the same manner as in the above (B-1) using the above monomer component to obtain a resin having an average molecular weight of 7,000. The obtained resin is dissolved in the same amount of xylene to obtain a solid content of 50.
% Resin solution was prepared.

(B-3) Isocyanate group-containing fluororesin n-butyl methacrylate 35 parts 2-ethylhexyl methacrylate 30 parts Isocyanatoethyl acrylate 10 parts Styrene 10 parts 2-perfluorooctylethyl acrylate 15 parts Azobisisobutyronitrile 2 parts To a mixture of 11% xylene in the same amount as the mixture.
The mixture was added dropwise at 0 ° C. over 3 hours and aged at the same temperature for 2 hours. The obtained resin has a solid content of 50% and an average molecular weight of 20,0.
It was 00.

Examples and Comparative Examples Examples 1 to 6 and Comparative Example 1 were mixed by mixing in the formulations shown in Table 1.
~ 3 paints were obtained.

[0123]

[Table 1]

Performance test results Clear paint: An electrodeposition coating film and an intermediate coating film were formed on a zinc phosphate-treated mild steel plate, and the following metallic paint was applied (film thickness: cured film thickness 20 μm), followed by 5 at room temperature. After leaving for a minute,
Apply the above clear paint on the coated surface (film thickness: 40
μ) and heated at 140 ° C. for 30 minutes to cure both coating films. The obtained coating film performance test results are shown in Table 2 together with the paint storability test results.

Metallic paint: Acrylic resin 100 parts (Dainippon Ink and Chemicals, Inc., Acridic 47-712) Uban 20SE-60 (same as above) 60 parts Aluminum paste 10 parts (Toyo Aluminum Co., aluminum paste 55-519) Solid color paint: The above-mentioned solid color paint was applied to each of the zinc phosphate-treated steel plates electrodeposited and intermediately coated in the same manner as described above (coating thickness: 40 μm).
It was heated at 140 ° C. for 30 minutes to be cured. The obtained coating film performance test results are shown in Table 2 together with the paint storability test results.

[0126]

[Table 2]

The test method is as follows.

Paint storage: Diluted paint (Ford Cup N
O. (4, 25 sec) 300 g was put in a beaker, lightly covered with aluminum haku, and after stirring at room temperature for 48 hours, the viscosity (Ford cup No. 4) was measured to examine the degree of thickening.

A: Less than 28 sec.

Δ: Less than 38 sec.

X: 38 seconds or more.

Scratch resistance: A dyed product friction fastness tester (manufactured by Daiei Kagaku Seiki Seisakusho) is used. Polishing powder (Dharma Cleanser) is kneaded with water and placed on the coated surface, and the tester terminal is pressed on the surface, and a 0.5 kg load is applied to rub it 25 times.

⊚: No change compared with the initial gloss.

◯: A slight luster occurred compared with the initial gloss.

Δ: Luster occurred compared to the initial gloss.

X: Remarkably glossy compared to the initial gloss.

Appearance of coating film: The appearance (armpits, stripes, smoothness, etc.) was visually evaluated.

Acid resistance: After dipping in 40% H ₂ SO ₄ at 40 ° C. for 5 hours, it was taken out and washed with water to evaluate the coated state. There were four grades of ◎, ○, △, and × depending on the degree of no abnormalities (⊚), remarkable glossiness, and soaking (x).

Impact resistance: A DuPont type impact tester was used (ram diameter 1/2 inch, weight 0.5 kg). The maximum weight drop height that does not cause cracks in the coating is displayed.

Contamination resistance: 1 g of JIS type 15 contaminated dust was placed on a 5 × 5 cm coated plate, uniformly spread by sweeping it with a brush 20 times, and left standing at 20 ° C. for 24 hours. Next, this was washed in running water using a clean brush to examine the degree of contamination.

⊚: No stain was observed ◯: Slight stain was observed Δ: Significant stain was observed and failed ×: Significant stain was observed Water repellency: Numerical value obtained by measuring the contact angle of water to the coated surface Show. Measured values are measured using a contact angle meter manufactured by Kyowa Kagaku Co., Ltd.
The contact angle was measured 3 minutes after dropping 0.03 ml of distilled water (at 20 ° C.). The larger the number, the greater the water repellency.

Water resistance: After being immersed in warm water of 40 ° C. for 240 hours, it was washed with water and the coated surface was observed and evaluated according to the following criteria.

A: No change at all

◯: Slightly glossy.

X: The coated surface was whitened.

Weather resistance: According to the QUV accelerated baculo test using an accelerated weather resistance tester manufactured by Q Panel Co.

Test conditions: UV irradiation 16 H / 60 ° C. water condensation 8 H / 50 ° C. as one cycle, 3000 hours (125 cycles) were tested to evaluate the coating film.

⊚: The gloss that is almost the same as the initial stage is maintained. ◯: There is a slight decrease in gloss, but there are no defects such as cracks and whitening. X: Significant decrease in gloss, cracking, and whitening (choking).
Phenomenon recognized and failed

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location C09D 133/14 PGE 7921-4J 161/20 PHK 8215-4J (72) Inventor Yasushi Nakao Hiratsuka, Kanagawa Prefecture Kanagawa Paint Co., Ltd. 4-17-1, Higashi-Hachiman, Higashi-shi (72) Inventor Motoshi Yabuta 4-17-1, Higashi-Hachiman, Hiratsuka, Kanagawa Kansai Paint Co., Ltd.

Claims (1)

[Claims] 1. The following components (A) to (C) (A) General formula (1) (In the formula, A is R ₁ is a hydrogen atom or a methyl group, and R ₂ is a carbon atom of 1 to
6 divalent saturated aliphatic hydrocarbon groups, R ₃ and R ₄ are the same or different and are a phenyl group, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms, and R ₅ is a carbon number. 1 to 10 alkyl groups are shown respectively. m is 0 or 1
, N is an integer of 1 to 100. 5 to 40% by weight of a vinyl monomer containing an alkoxysilane group, 5 to 60% by weight of a vinyl monomer containing a hydroxyl group, and 90% by weight or less of another copolymerizable vinyl monomer, which is a compound represented by 20-89% by weight (B) a fluorine-based resin having a functional group 1-50% by weight and (C) an amino resin 10-50% by weight. A coating composition comprising: