JP2000313838A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating composition which is excellent in pot life and adhesion to a primer and gives a coating film excellent in resistances to staining and weather by incorporating a fluorocopolymer having hydrolyzable silyl groups, a reaction product of an epoxy compound with a primary or secondary amine, a cure catalyst and an organic solvent as essential ingredients into the same. SOLUTION: Preferably, the fluorocopolymer having hydrolyzable silyl groups comprises monomer units derived from an olefinic monomer having a hydrolyzable silyl group, (meth)acrylic ester monomer units and fluoroolefin monomer units as essential monomer units and has a number average mol.wt. of 1,000-100,000 and a glass transition temperature of -20 to 60 deg.C. Preferably, the coating composition further contains a condensate of hydrolyzate of an alkoxysilane as an essential ingredient. In order to improve the adhesion to a substrate, this composition is preferably applied after the application of a weak-solvent type primer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solvent-based coating composition, and more particularly to a fluorine-based coating composition having excellent stain resistance and weather resistance.

[0002]

2. Description of the Related Art In recent years, a solvent-soluble fluorine coating has been used as a resin for building coatings having high weather resistance. Particularly, among the solvent-soluble fluorine coatings, a hydrolyzable silyl group is used as a moisture crosslinkable resin. The contained resin is used. As this moisture crosslinkable resin, for example, a fluorinated copolymer obtained by copolymerizing a fluoroolefin, vinyl ether, and an olefinic monomer having a hydrolyzable silyl group is disclosed (Japanese Patent Publication No. 1-14055). ). Paints prepared from this copolymer have excellent weather resistance, but have poor adhesion to substrates, and thus have a problem that the choice of primer (undercoat material) at the time of coating is narrow. On the other hand, as a method of improving the adhesion to the primer, a method of blending an organic silicate (Japanese Patent Publication No. 63-32)
No. 826), a method of compounding a silane compound having an epoxy group (Japanese Patent Publication No. 63-25029), and a method of compounding an amine compound (Japanese Patent Application Laid-Open Nos. 9-157586 and 10-168386). Have been. However, in any of the above methods, there is no problem if the interval between the application of the primer and the application of the fluorine paint is several days, but the longer the application interval (that is, the more the curing of the primer proceeds), the closer the adhesion. There is a problem that it becomes difficult. Further, it was found that when a weak solvent type primer was used as the primer, the above-described method had little improvement effect. Further, it is necessary to add a hydrolysis-condensation product of an alkoxysilane to the paint in order to reduce the contamination of the coating film (Japanese Patent Laid-Open No. 7-48540), but in this case, the adhesion is further reduced. Further, the method of adding an amine compound has a problem that the pot life after compounding the coating composition becomes extremely short. Therefore, even when the top coat is applied after a long time has passed since the application of the primer, or when a hydrolysis-condensation product of alkoxysilane is added, the coating composition does not decrease in adhesion, and the pot life is reduced. What is not desired is desired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide excellent stain resistance and weather resistance, as well as excellent pot life,
Another object of the present invention is to provide a coating composition having excellent adhesion to a primer.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a fluorine-containing copolymer having a hydrolyzable silyl group can be added to an epoxy group-containing compound and an amine. Reactant, found that good adhesion can be obtained even after the sufficient time has elapsed after coating the primer and that the pot life is excellent,
The present invention has been completed. That is, the present invention is a coating composition containing the following (A) to (D) as essential components. (A) a fluorine-containing copolymer containing a hydrolyzable silyl group (B) a reaction product of an epoxy group-containing compound with a primary or secondary amine (C) a curing catalyst (D) an organic solvent

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The (A) fluorine-containing copolymer containing a hydrolyzable silyl group in the present invention is a copolymer comprising a fluoroolefin monomer unit and an olefinic monomer unit having a hydrolyzable silyl group as essential components. It is united.
Examples of the fluoroolefin include tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, dichlorodifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, and perfluoro (alkyl vinyl ether).
Among these, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene and trifluoroethylene are preferred from the viewpoint of polymerizability, and tetrafluoroethylene, chlorotrifluoroethylene and trifluoroethylene are more preferred.

The olefinic monomer having a hydrolyzable silyl group is a compound represented by the following formula (1). _{R-SiX n Y 3-n} (1) (R is a group having an olefinic unsaturated bond, X represents an alkyl group having 1 to 20 carbon atoms, Y is a hydrolyzable radical, n is 0 It is an integer up to 2. When there are a plurality of X and Y, they may be the same or different.) Specific examples of R include vinyl, allyl, butenyl,
Vinyloxy, allyloxy, acryloyl, methacryloyl, CH ₂ ＣＨCHO (CH ₂ ) ₃ —, CH ₂ ＣC
_{HCOO (CH 2) 3 -,} CH 2 = CHOCO (CH 2) 3
—, CH ₂ ＣC (CH ₃ ) COO (CH ₂ ) ₃ —, CH ₂ =
C (CH ₃ ) COO (CH ₂ ) ₂ —O— (CH ₂ ) ₃ — and the like, among which a vinyl group is preferable. X includes a methyl group, an ethyl group, a propyl group, an octyl group, an octadecyl group and the like. Examples of Y include a hydrolyzable group such as an alkoxy group, an amino group, an acyloxy group, a phenoxy group, a mercapto group, and an iminooxy group. Among these, an alkoxy group is particularly preferable. Specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group and the like. Among these, a methoxy group and an ethoxy group are preferable.

Specific examples of the olefinic monomer having a hydrolyzable silyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltris (β- Methoxyethoxy) silane, trimethoxysilylethyl vinyl ether, trimethoxysilylbutyl vinyl ether, methyldimethoxysilylethyl vinylether, trimethoxysilylpropylvinylether, vinyltriisopropenyloxysilane, vinylmethyldiisopropenyloxysilane, triisopropenyloxysilylethyl Vinyl ether, triisopropenyloxysilylpropyl vinyl ether, triisopropenyloxysilylbutyl vinyl ether, Rutorisu (dimethyl imino oxy) silane, vinyltris (methyl ethyl imino-oxy) silane, vinyl methyl bis (dimethyl imino oxy) silane, vinyl dimethyl (dimethyl imino oxy)
Silane, tris (dimethyliminooxy) silylethyl vinyl ether, methylbis (dimethyliminooxy)
Silylethyl vinyl ether, tris (dimethyliminooxy) silylbutyl vinyl ether, γ- (meth) acryloyloxypropyltrimethoxysilane, γ-
(Meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane and γ- (meth) acryloyloxypropyltriisopropenyloxysilane.

In addition to the above essential monomers, the fluorinated copolymer (A) contains other olefinic monomers in view of solubility in an organic solvent and flexibility of a crosslinked coating film. It is preferable to polymerize, and these monomers include (meth)
Acrylates; vinyl esters; vinyl ethers and the like. Among these, (meth) acrylates are preferred because of their long adhesion time to the primer, (B) a reaction product of an epoxy group-containing compound and an amine, and (C) a pot life after compounding a curing catalyst. preferable.

The (meth) acrylates include:
As the ester chain, those having an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, and a halogen-containing alkyl group are preferable, and oxygen,
It may contain atoms such as nitrogen and sulfur. For example, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, (meth) Neopentyl acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, ( Isobornyl (meth) acrylate, (meth)
Tricyclodecynyl acrylate, tetrahydrofurfuryl (meth) acrylate, 4-methylcyclohexylmethyl (meth) acrylate, methoxyethyl acrylate,
Alkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, chloroethyl (meth) acrylate, trifluoroethyl (meth) acrylate and pentafluoropropyl (meth) acrylate; Are used alone or as a mixture of several types. Among these, the use of alkyl acrylates is preferred for reasons such as polymerizability with the fluoroolefin and flexibility of the copolymer.

As vinyl esters, vinyl acetate,
Examples thereof include vinyl carboxylate esters such as vinyl propionate, vinyl caproate, vinyl pivalate, Vova-9 (manufactured by Shell Chemical), vinyl cyclohexanecarboxylate, and vinyl benzoate.

The vinyl ethers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, n-pentyl vinyl ether, hexyl vinyl ether, n-octyl vinyl ether,
Examples thereof include alkyl vinyl ethers such as ethylhexyl vinyl ether, chloromethyl vinyl ether, and chloroethyl vinyl ether or substituted alkyl vinyl ethers; and cycloalkyl vinyl ethers such as cyclopentyl bunyl ether and cyclohexyl vinyl ether.

Also, α-olefins such as ethylene, propylene and isobutylene, and chloroethylenes such as vinyl chloride and vinylidene chloride can be copolymerized with the fluorine-containing copolymer as long as physical properties are not impaired. Further, the fluorine-containing copolymer may include a monomer unit having a functional group such as a hydroxyl group, an epoxy group, and a carboxyl group. As the hydroxyl group-containing monomer,
2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, allyl alcohol, cinnamon alcohol, N -In addition to hydroxyl group-containing monomers such as methylol (meth) acrylamide, 2-hydroxyethyl crotonate and 4-hydroxybutyl crotonate, ring-opening addition of ε-caprolactam and ethylene oxide was performed on these hydroxyl group-containing monomers. Compound or unsaturated carboxylic acid such as (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid and ethylene glycol, ethylene oxide, propylene glycol, propylene oxide, butylene glycol, cyclohexanedimeta Lumpur, glycerol, which are reaction products of polyhydric alcohols such as trimethylolpropane monomers are exemplified. As a monomer having an epoxy group,
Examples include glycidyl (meth) acrylate and allyl glycidyl ether. Examples of the monomer having a carboxyl group include (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid and crotonic acid.

The fluorine-containing copolymer of the present invention has solubility in an organic solvent, weather resistance of a cured coating film, flexibility, stain resistance,
From the balance of the adhesion to the substrate, the ratio based on the total amount of the essential constituent monomers is fluoroolefin (a): 7.
７０70 mol%, olefinic monomer (b) having a hydrolyzable silyl group: 1-20 mol%, and other monomer (c): 20-80 mol%. A more preferred range is (a): 20 to 60 mol%,
(B): 2 to 10 mol%, (c): 30 to 75 mol%. Further, the monomer (d) which can be contained within a range that does not impair the physical properties described above can be used in the range of 0 to 30 mol% by substituting a part of the other monomer (c).
If (a) exceeds 70 mol%, the solubility of the fluorinated copolymer in an organic solvent decreases, and if it is less than 7 mol%, the weather resistance decreases. Further, when (b) is less than 1 mol%, since the number of crosslinking points is small, the strength of the film formed from the paint,
Solvent resistance decreases. On the other hand, if it exceeds 20 mol%, the stability of the copolymer will decrease. When (c) is less than 20 mol%, the effect of improving the adhesion when (B) a reactant of an epoxy group-containing compound and an amine is added is reduced, and 80% or less.
If it exceeds mol%, the proportion of the fluoroolefin decreases and the weather resistance decreases.

The molecular weight of the fluorinated copolymer is preferably in the range of 1,000 to 100,000 as a number average molecular weight (in terms of polystyrene) determined by gel permeation chromatography (GPC). Glass transition temperature (Tg)
Is preferably −20 ° C. to 60 ° C.

The fluorine-containing copolymer can be produced by a method of copolymerizing the above monomers in the presence of a radical-generating polymerization initiator. As the polymerization method, a usual method such as solution polymerization in an organic solvent can be adopted. Examples of the radical-generating polymerization initiator include diisopropyl peroxydicarbonate, te
Peroxides such as rt-butylperoxypivalate, benzoyl peroxide and lauroyl peroxide, azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile, and inorganic peroxides such as ammonium persulfate and potassium persulfate These initiators are preferably used in the range of 0.0001 to 10 mol% based on the total amount of monomers. In the case of emulsion polymerization, as an emulsifier,
Examples thereof include potassium perfluorooctanoic acid and ammonium salts, ammonium perfluorooctanesulfonate, sodium salts of higher alcohol sulfates, and polyethylene glycol ether. These emulsifiers are used in an amount of 0.1 to 100 parts by weight of the total monomers. Preferably, it is used in an amount of up to 50 parts by weight.

Examples of the organic solvent in the solution polymerization include cyclic ethers such as tetrahydrofuran and dioxane;
Hydrocarbons such as hexane and cyclohexane; toluene,
Aromatic hydrocarbon compounds such as xylene; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone and cyclohexanone; alcohols such as ethanol, isopropanol, n-butanol and n-butyl cellosolve; -Trichloro 1, 2, 2
And fluorocarbons such as trifluoroethylene, etc., and one or more of these can be used. The amount of the organic solvent used is 20 to 20 with respect to 100 parts of the total monomer.
It is preferable to use 0 parts.

The polymerization conditions are not particularly limited.
The preferred polymerization temperature is 20-100 ° C., the preferred pressure is 1-200 kg / cm 2, and the preferred polymerization time is 3-40
Time. The monomers used in the polymerization may be initially charged in batches at the beginning, or some of the monomers may be added sequentially as the polymerization proceeds. If necessary, pH
Potassium carbonate, sodium bicarbonate, hydrotalcite, anion exchange resin and the like may be added as a regulator.

The essential component (B) in the present invention is a reaction product of an epoxy group-containing compound and a primary or secondary amine, and it is presumed that an addition reaction occurs as a reaction. Examples of the epoxy group-containing compound include 1,2-epoxybutane, 1,2-epoxycyclohexane, 1,2-epoxy-4-glycidylcyclohexane, epiol series {epoxy group-containing compound of NOF Corporation},
Examples thereof include 1,2-diglycidyl phthalate and 1,4-diglycidyl phthalate. Also, γ-glycididoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and β- (3,4- Epoxy group-containing silane coupling agents such as (epoxycyclohexyl) ethyltrimethoxysilane can also be used. These epoxy group-containing compounds can be used alone or in combination.

The primary or secondary amines include
Ethylamine, propylamine, isopropylamine,
Primary amines such as butylamine, hexylamine, heptylamine, cyclohexylamine, aniline, hexamethylenediamine and ethylenediamine, secondary amines such as dimethylamine, diethylamine, diisopropylamine, dibutylamine and morpholine, ethanolamine, diethanolamine And other hydroxyl-containing amines, such as aminomethyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N
And amino group-containing silane coupling agents such as -β (aminoethyl) γ-aminopropyltriethoxysilane and γ-aminopropyltriethoxysilane. These amines can be used alone or in combination of two or more. . Among these, one of the epoxy group-containing compound and the amine is preferably a coupling agent also having a hydrolyzable silyl group, since the adhesion improving effect is large, and in particular, the pot life is not shortened. In this respect, the epoxy group-containing compound is preferably an epoxy group-containing silane coupling agent.

The reaction between the epoxy group-containing compound and the amines can be carried out by mixing a predetermined amount of the epoxy group-containing compound and the amines in a solvent-free or organic solvent while heating. In the case of a primary amine, the mixing ratio of the epoxy group-containing compound and the amine is preferably in the range of 1/1 to 4/1 by mole ratio of the epoxy group and the NH ₂ group of the amine. Similarly, in the case of secondary amines, it is preferable that the molar ratio of the epoxy group to the NH group of the amine is in the range of 1/1 to 2/1. However, when a primary amine is used, if unreacted NH ₂ remains, the pot life when mixed with the fluorinated copolymer decreases, so that the reaction is preferably charged with an epoxy group in an amount larger than the equivalent. The amount of the unreacted primary amines is preferably as small as possible. Specifically, the amount of the unreacted primary amines is 1.0 part by weight or less based on 100 parts by weight of the fluorinated copolymer in the composition. Is preferred.

The mixing ratio of (B) is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the fluorine-containing copolymer. When the proportion of (B) is 0.1 parts by weight or less, the adhesion to the weak solvent type primer cannot be improved. On the other hand, when the proportion exceeds 10 parts by weight, the pot life decreases, and the weather resistance may further decrease. is there.

The coating composition of the present invention is in the form of a two-pack type coating composition containing (C) a curing catalyst at the time of coating. As the curing catalyst, cobalt naphthenate, lead naphthenate,
Calcium octylate, lead octylate, zinc octylate, cobalt octylate, tetrapropyl titanate,
Organic tin compounds such as tetrabutyl titanate, dibutyltin dilaurate, dioctyltin dilaurate, dichlorodibutyltin, dibutyltin diacetate and triethyltin monostearate are exemplified. The amount of the curing catalyst used is 20 ppm to 5% per 100 parts by weight of the fluorocopolymer.
Is more preferable, and 100 ppm to 1% is more preferable.

The organic solvent (D) is not particularly limited as long as it is an organic solvent that dissolves the fluorine-containing copolymer.
Specifically, aromatic solvents such as toluene, xylene, and solvesso; n-heptane, n-hexane, n-pentane, n
-Octane, n-nonane, n-decane, n-undecane, terpin oil, mineral spirit, HAWS (solvent mainly composed of an aliphatic hydrocarbon manufactured by Shell Chemical), naphtha No. 6, naphtha No. 5 (all manufactured by Exxon) Solvents such as ethyl acetate, butyl acetate, and isobutyl acetate; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl amyl ketone, and ethyl amyl ketone;
alcohols such as n-butanol and i-propanol;
Cellosolves such as methyl cellosolve, n-butyl cellosolve and n-butyl cellosolve acetate; propylene glycol solvents such as propylene bricol monomethyl ether, propylene bricol monobutyl ether and propylene glycol monomethyl ether acetate; and the like, these organic solvents are used alone. Alternatively, they can be used in combination. When a weak solvent type primer is used as the primer of the coating composition in the present invention, it is preferable to use a petroleum solvent as the organic solvent of the coating composition.

It is preferable to add a hydrolysis-condensation product of an alkoxysilane to the coating composition of the present invention in order to develop stain resistance. The hydrolysis-condensation product of alkoxysilane is a hydrolysis-condensation product of alkoxysilane having two or more hydrolyzable alkoxy groups in one molecule, and the degree of condensation is 2 from the viewpoint of stain resistance and compatibility with the fluorine-containing resin.
It is preferably about 10 to 10. As such a compound, for example, those commercially available from Colcoat as ES40 (condensate of tetraethoxysilane on average of about pentamer), MS51 (condensate of tetramethoxysilane on average of about tetramer) and the like can be used. Can be. Further, Japanese Unexamined Patent Publication No.
Those synthesized by the methods described in JP-A-176304, JP-A-8-113755 and JP-A-9-31399 can be used. The mixing ratio of the hydrolyzed condensate of the alkoxysilane is 2 per 100 parts by weight of the fluorine-containing resin in terms of the solid content of the hydrolyzed condensate of the alkoxysilane.
To 100 parts by weight, preferably 5 to 80 parts by weight. When the proportion of the alkoxysilane condensate is 2 parts by weight or less, the stain resistance is not improved, and when it exceeds 100 parts by weight, the coating film formed becomes brittle.

In the coating composition of the present invention, orthoacid esters may be added for the purpose of improving the storage stability before adding the curing catalyst of the essential component (C). Ortho acid esters are compounds represented by the general formula RC (OR ') ₃ (R: hydrogen atom, methyl group, ethyl group; R': alkyl group having 1 to 3 carbon atoms). Specific examples include trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, tripropyl orthoacetate, trimethyl orthopropionate, triethyl orthopropionate, and tripropyl orthopropionate. . By adding the orthoacid ester, the storage stability of the present composition is improved, and the amount of the addition is 0.1 to 100 parts by weight of the total amount of the hydrolyzate of the fluorocopolymer and the alkoxysilane in the composition. 5-
Desirably 30 parts by weight. If the amount is less than 0.5 part by weight, the effect of improving the storage stability is not (or only slightly), and the effect is not changed even if it is added in an amount of 30 parts by weight or more.

The coating composition of the present invention is particularly excellent in adhesion to a weak solvent type primer. The weak solvent type primer is a paint prepared from a resin dissolved or dispersed in a petroleum-based solvent. Examples of such paints include a weak solvent-soluble acrylic urethane paint, a weak solvent-dispersed acrylic urethane paint, a weak solvent-soluble epoxy paint, a weak solvent-dispersed epoxy paint, and a weak solvent-soluble epoxy paint with a ketimine hardener. Type used, weak solvent-dispersed epoxy paint with ketimine hardener, weak solvent-soluble alkyd paint, weak solvent-dispersed urethane paint, weak solvent-dispersed acrylic silicone paint, weak solvent-soluble acrylic silicone paint, weak Solvent-soluble fluorine paints and weak solvent dispersion-type fluorine paints are exemplified.

Further, the coating composition of the present invention includes:
Additives such as pigments, ultraviolet absorbers, light stabilizers, flow regulators, leveling agents, slip agents, dispersants, color separation inhibitors, antioxidants, and other silane coupling agents can be added. As pigments, for example, titanium oxide, red iron,
Inorganic pigments such as calcined pigments and pearl pigments, organic pigments such as phthalocyanine blue, phthalocyanine green, quinacridone red, perylene, isoindolinone and carbon black, volume pigments such as calcium carbonate and barium sulfate, and metallics such as aluminum flakes and stainless flakes Pigments. In addition, as a matting agent, polyethylene wax, polypropylene wax, and silica matting agent can be added. Organic ultraviolet absorbers such as benzophenone-based compounds, benzotriazole-based compounds, and oxalic anilide-based compounds, and inorganic ultraviolet absorbers such as ultrafine titanium oxide and cerium oxide can be used as the ultraviolet absorber.

The coating composition of the present invention can be applied on various organic coating films by spray coating, roll coater, brushing, or the like, but can also be applied directly to a substrate. As a substrate that can be applied, it can be directly applied to a metal, plastic, wood, paper, ceramic, cement-based substrate, or the like. Examples of the metal include SUS, aluminum, and zinc steel plate. AB as plastic
Examples include S, FRP, PC, hard PVC, bakelite, epoxy, polyacryl, and polyurethane, and examples of the cement-based substrate include mortar and concrete. The thickness of the coating is preferably 10 to 100 μm when dried. As a method of coating the coating composition,
A method of coating the coating composition on a weak solvent primer is preferred because the adhesion to a substrate is improved.

[0029]

The present invention will be specifically described below with reference to examples. (Preparation of Pigment Dispersion) Consisting of chlorotrifluoroethylene (hereinafter, referred to as CTFE) / cyclohexyl acrylate (hereinafter, referred to as CHA) / vinyltrimethoxysilane (hereinafter, referred to as VMS), and the composition ratio is 38/57.
/ 5 (mol%) and the number average molecular weight Mn = 14,000
Using a 60% by weight solution of butyl acetate of a fluorine-containing copolymer (F-1) containing a hydrolyzable silyl group that is 0,
After blending the following and dispersing the pigment with a paint conditioner, the glass beads were filtered and a white dispersion (W-1) was obtained.
Was prepared. 60% butyl acetate solution of F-1 62.0 g Titanium oxide {Ishihara Sangyo Co., Ltd .: CR95} 24.8 g Dispersant (Big Chemie: Disperbyk 110) 0.3 g Naphtha No6 11.0 g Trimethyl orthoformate 1.9 g Glass beads 80.0g

The fluorinated copolymer consists of CTFE / butyl acrylate (hereinafter referred to as BA) / CHA / VMS, the composition ratio of which is 42/5/48/5 (mol%) and Mn = 13,000. Except for using a 60% by weight solution of a copolymer (F-2) of a mixed solvent of naphtha No. 6 / butyl acetate = 9/1, a white dispersion (W-
2) was prepared.

(Synthesis of Reaction Product of Epoxy Group-Containing Compound and Amines) Synthesis Example 1 Epiol NPG-100 (trade name) NOF Corporation
Dipentylglycol diglycidyl ether)
21.6 g (0.2 mol as epoxy group), 20.6 g (0.16 mol) of dibutylamine, HAWS
29.5 g of butyl acetate and 12.7 g of butyl acetate were added under a nitrogen stream.
The mixture was reacted at 0 ° C. for 8 hours to produce an adduct (A-1).
The molar ratio between the charged epoxy group and the amino group was 1.25 / 1. The conversion of dibutylamine by gas chromatography was 80 mol% (the unreacted amine in the composition was 4.9% by weight). The reaction product was used without isolation.

Synthesis Example 2 21.6 g of epiol NPG-100 (0.2 mol as an epoxy group), 15.0 g of heptylamine
(0.13 mol), 25.6 g of naphtha No6, and 9.9 g of butyl acetate were reacted under the same reaction conditions as in Synthesis Example 1 to obtain a reaction product (A-2). The charged molar ratio between the epoxy group and the amino group was 1.54 / 1. The conversion of heptylamine by gas chromatography is 90 mol% (the unreacted amine in the composition is 2.0% by weight),
The reaction product was used without isolation.

Synthesis Example 3 A-187 (trade name: epoxy group-containing silane coupling material, manufactured by Nippon Yunika Co., Ltd.) 21.7 g (0.1 mol as epoxy group), Epiol E-400 (trade name:
10.4 g (0.06 mol as an epoxy group), 17.2 g (0.15 mol) of heptylamine, ethylene glycol diglycidyl ether manufactured by NOF Corporation
A reaction product was obtained by reacting 24.7 g of naphtha No6 and 24.6 g of butyl acetate under the same reaction conditions as in Synthesis Example 1.
-3). The charged molar ratio between the epoxy group and the amino group is 1.0
7/1. The conversion of heptylamine by gas chromatography was 85 mol% (the amount of unreacted amine in the composition was 2.6% by weight). The reaction product was used without isolation.

Synthesis Example 4 A-187 21.7 g (0.1 mol), A-1170
<< Brand name: Bis (triethoxysilylpropyl) amine, manufactured by Nippon Unicar Co., Ltd. >> 27.3 g (0.08 mol), 24.5 g of naphtha No6, butyl acetate
5 g was reacted under the same reaction conditions as in Synthesis Example 1 to obtain a reaction product (A-4). The charged molar ratio between the epoxy group and the amino group was 1.25 / 1. The conversion of A-1170 by gas chromatography was 90% (unreacted amine in the composition was 2.8% by weight). The reaction product was used without isolation.

Synthesis Example 5 Epiol NPG-100 23.8 g (0.11 mol), A-1120 (trade name: manufactured by Nippon Unicar Co., Ltd.)
Synthesis Example 1 N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane｝ 11.1 g (0.10 mol), naphtha No6 24.4 g, butyl acetate 10.5 g
The reaction was carried out under the same reaction conditions as described above to obtain a reaction product (A-5).
The charged molar ratio between the epoxy group and the amino group was 1.1 / 1. The conversion of A-1120 by gas chromatography was 90 mol% (the unreacted amine in the composition was 1.6% by weight). The reaction product was used without isolation.

Synthesis Example 6 10.8 g (0.05 mol) of epiol NPG-100, 36.4 g (0.5 mol) of butylamine, 23.6 g of naphtha No6, and 12.7 g of butyl acetate were reacted in the same manner as in Synthesis Example 1. A reaction product was obtained under the conditions (A-
6). The charged molar ratio between the epoxy group and the amino group was 1/5. The conversion of butylamine by chromatography was 16 mol% (the unreacted amine in the composition was 32.4% by weight). The reaction product was used without isolation.

(Preparation of Paint Composition) Examples 1 to 7 White paints were blended according to the following Table 1 (the numbers in Table 1 indicate weight).

[0038]

[Table 1]

Comparative Examples 1 to 5 White paints were compounded according to the following Table 2 (the numbers in Table 2 indicate weight).

[0040]

[Table 2]

The following tests were carried out on the coating compositions of Examples 1 to 7 and Comparative Examples 1 to 5. The results are shown in Table 3 below. Adhesion Test 1 Escomild, a weak solvent type epoxy primer manufactured by Kansai Paint Co., Ltd., is applied on a 5052P aluminum plate (dry film thickness: about 30 μm). After drying outdoors for one month, the compositions of Examples 1 to 7 and Comparative Examples 1 to 5 are spray-coated thereon (dry film thickness: about 30 μ). After drying for one week in a constant temperature room at 23 ° C. and a relative humidity of 50%,
Immerse in hot water for 2 days. The coating film immediately after being taken out of the hot water and after being left for 4 hours was cut in a grid (100 meshes), and the cellophane tape was peeled off. The results are shown in Table 3 below. Adhesion test 2 Epoxy primer: Eton 2100 manufactured by Kawakami Paint Co., Ltd. is applied on a 5052P aluminum plate (dry film thickness: about 30).
μ). After drying one month outdoors, Examples 1 to 3
7 and the paints of Comparative Examples 1 to 5 are applied by spraying (dry film thickness: about 30 μ). 1 in a constant temperature room at 23 ° C and 50% relative humidity
After drying for a week, the dried coating film is immersed in warm water at 40 ° C. for 2 days. The coating film immediately after being taken out of the hot water and after leaving for 4 hours was cut in a grid (100 meshes), and the cellophane tape was peeled off. The results are shown in Table 3. Pot life The coating composition was blended into a polycup, and the time required to start thickening was measured. The results are shown in Table 4 below. Stain resistance 50% of the coating compositions of Examples 1 to 7 and Comparative Examples 1 to 5
Spray paint on 52P aluminum plate (dry film thickness about 30
μ). Dry for 1 week in a constant temperature room at 23 ° C. and 50% relative humidity. Dried coatings were applied to an industrial area in the southern part of Nagoya City for 45 months for three months.
Exposure at an angle of degree, the difference in lightness between the initial and the test (ΔL)
Was measured. Table 4 shows the results. Accelerated weather resistance The gloss retention (%) after 2,000 hours of testing with a sunshine weather meter under the conditions according to JIS K5400 was measured, and the results are shown in Table 4.

[0042]

[Table 3]

[0043]

[Table 4]

[0044]

EFFECT OF THE INVENTION The coating composition of the present invention not only gives a coating film excellent in stain resistance and weather resistance, but also has excellent pot life and excellent adhesion, and can be used for various applications. It is.

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Claims (4)

[Claims] 1. A coating composition comprising the following components (A) to (D) as essential components. (A) a fluorine-containing copolymer containing a hydrolyzable silyl group (B) a reaction product of an epoxy group-containing compound with a primary or secondary amine (C) a curing catalyst (D) an organic solvent 2. The method according to claim 1, wherein the (A) fluorinated copolymer having a hydrolyzable silyl group comprises an olefinic monomer unit having a hydrolyzable silyl group, a (meth) acrylate monomer unit and a fluoropolymer. The coating composition according to claim 1, wherein the olefin monomer unit is an essential constituent monomer unit. 3. The coating composition according to claim 1, wherein a hydrolysis-condensation product of an alkoxysilane is an essential component in addition to the components (A) to (D). 4. A method for coating a coating, comprising coating the coating composition according to claim 1 on a weak solvent type primer.