JP2003126774A - Coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating method giving a good finish in a very short time as a coating method for an automotive outer panel, a railway vehicle, industrial machinery, woodwork, etc. SOLUTION: A surface to be coated is coated with a photo-curable putty composition (I) and further coated with a photo-curable primer composition (II) comprising an acrylic resin (A) containing a polymerizable unsaturated group in a side chain through a urethane bond, a urethane (meth)acrylate oligomer (B) containing one or more polymerizable unsaturated groups in one molecule and a photopolymerization initiator (C). After irradiation with light, the coated surface is coated with a colored base coating material composition (III) and a clear composition (IV) in order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method for outer panels of automobiles, railway vehicles, industrial equipment, woodworking, etc., and relates to a coating method capable of obtaining a good finish in a very short time. The present invention is particularly useful for repairing automobiles.

[0002]

2. Description of the Related Art For repair coating of automobile outer panels, etc., the old coating film on the damaged part is peeled off, putty material is filled into the damaged part, the putty surface is ground after drying, and then on top of this. A coating system is used in which a primer is painted, polished, and then top-coating and clear-coating are performed in order.

As a coating material used in such a repair system, for example, an unsaturated group-containing polyester resin type room temperature curing type two-component type coating material is used for the putty layer, and an acrylic urethane type coating material is used for the primer layer and the clear layer. A two-pack type paint is generally used, and usually, natural drying or forced drying with hot air is performed. In this repair coating method, there is a problem that it takes a long time as a whole of all repair steps because it takes 20 minutes to 1 hour to dry the coating in a 60 ° C. atmosphere for curing. Further, all of the coating materials are of the two-component type, which is difficult to handle, and there has been a demand for a shift to the one-component type.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a one-pack type photocurable composition in an undercoat layer, and further used it as a base coat material or a clear paint. According to the present invention, it is found that the use of a one-pack type composition makes it possible to form a coating film which is easy to handle and the time required for the entire repairing process can be significantly shortened, and which has good properties such as hardness, interlayer adhesion and finish. Reached

That is, the present invention is as follows: A photocurable putty composition (I) is applied to the surface of an object to be coated, and then an acrylic resin (A) containing a polymerizable unsaturated group in its side chain through a urethane bond is added thereto, and one is present in one molecule. The above-mentioned urethane (meth) acrylate oligomer (B) containing a polymerizable unsaturated group and the photocurable primer composition (II) containing a photopolymerization initiator are coated and irradiated with light, and then a colored base is formed thereon. 1. A coating method characterized by sequentially coating the coating composition (III) and the clear composition (IV), 2. The coating method according to 1, wherein the colored base coating composition (III) and the clear composition (IV) are both one-pack type. The clear composition (IV) contains (a) a resin containing at least one functional group selected from a siloxy group and an isocyanate group, and (b) a siloxy group and an isocyanate group.
A compound containing at least one functional group which is selected from the group G and which can react with the functional group contained in the resin (a),
3. The coating method according to 1 or 2, which is a one-pack type clear composition containing (c) a siloxy group dissociation catalyst. The clear composition (IV) contains (a) a resin containing at least one functional group selected from a siloxy group and an isocyanate group, and (b) a siloxy group and an isocyanate group.
A compound containing at least one functional group which is selected from the group G and which can react with the functional group contained in the resin (a),
4. The coating method according to 1 or 2, which is a one-pack type clear composition containing (c) a siloxy group dissociation catalyst, (d) a polymerizable unsaturated group-containing compound, and (e) a photopolymerization initiator. A resin, in which the clear composition (IV) has (f) a polymerizable unsaturated group and at least one functional group selected from a siloxy group and an isocyanate group, (b)
A compound containing at least one functional group selected from a siloxy group and an isocyanate group and capable of reacting with the functional group contained in the resin (a), (c) a siloxy group dissociation catalyst, and (e) photopolymerization 5. The coating method according to 1 or 2, which is a one-pack type clear composition containing an initiator. A coating layer formed of the photocurable putty composition (I) and a coating layer formed of the photocurable primer composition (II) formed on the coating surface are irradiated with light rays to simultaneously expose both coating surfaces. 6. The coating method according to item 1, which is cured. 7. The coating method according to item 3, wherein the colored base coating composition (III) is coated, the clear composition (IV) is coated on the coating film surface, and both coating film surfaces are simultaneously cured by heating. The coating according to 4 or 5, wherein the colored base coating composition (III) is applied, the clear composition (IV) is applied on the coating film surface, and both coating film surfaces are simultaneously cured by irradiation with light rays. About the method.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The composition used in each coating step in the present invention will be described.

Photocurable Putty Composition (I) The photocurable putty composition (I) used in the method of the present invention is
The polymerizable unsaturated group-containing resin and the polymerizable unsaturated compound contain a photopolymerization initiator.

The polymerizable unsaturated group-containing resin is a resin having at least one ethylenically unsaturated group in one molecule, and examples thereof include polyester resin, acrylic resin, vinyl resin, polybutadiene resin, alkyd resin, epoxy resin, A resin such as a urethane resin having a (meth) acrylate group or an allyl group introduced therein may be used, and these may be used alone or in combination of two or more.

The polymerizable unsaturated compound is added as a reactive diluent in order to adjust the viscosity of the paint and the concentration of unsaturated groups in the paint. Specifically, it is a monomer having an ethylenically unsaturated group. Or an oligomer can be mentioned, for example, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
Isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tetra ( (Meth) acrylate, dipentaerythritol (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, 2,2-bis (4- (3-methacryloxy-2-hydroxypropoxy) -phenyl) propane, di (methacryloxy) Ethyl) trimethylhexamethylenediurethane, (meth) acrylic acid ester of monohydric or polyhydric alcohol such as 2,2-bis (4-methacryloxypolyethoxyphenyl) propane; ethylene Recall dimaleate, propylene glycol diitaconate; 4- (meth) acryloyloxy methoxycarbonyl phthalate, 4- (meth)
4- (meth) acryloyloxyl group-containing aromatic polycarboxylic acid such as acryloyloxyethoxycarbonylphthalic acid and its acid anhydride; styrene, α-methylstyrene, chlorostyrene, vinyltoluene, t-butylstyrene, divinylbenzene, etc. Aromatic vinyl compounds;
Examples thereof include diallyl phthalate, diallyl isophthalate, triallyl phthalate; epoxy acrylate, polyester acrylate, polydimethylsilicone di (meth) acrylate, urethane oligomer and the like, and these can be used alone or in combination of two or more.

In the present invention, "(meth) acrylate" means "acrylate or methacrylate".

The photopolymerization initiator may be any one as long as it can generate radicals by being excited by the light energy of irradiation with light rays such as ultraviolet rays, visible rays and near infrared rays to initiate radical polymerization. -Phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-
1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropane-1 -One, 4- (2-hydroxyphenoxy) -phenyl (2-hydroxy-2
-Propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio)
Acetophenone compounds such as phenyl] -2-morpholinopropanone-1; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,
Thioxanthone compounds such as 4-dichlorothioxanthone; benzyl, benzyl dimethyl ketal, benzyl-
Benzyl compounds such as β-methoxyethyl acetal and 1-hydroxycyclohexyl phenyl ketone; benzophenone, methyl o-benzoylbenzoate, Michler's ketone, benzophenone compounds such as 4,4′-bisdiethylaminobenzophenone and 4,4′-dichlorobenzophenone Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether and other benzoin ether compounds; camphor
Quinone, anthraquinone, 3-ketocoumarin, α-naphthyl, 2,4,6-trimethylbenzoyl, diphenylphosphine oxide, acylphosphine oxide, 2,
4,6-Trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl)-
Phenylphosphine oxide, 10-butyl-2-chloroacridone, fluorenone and the like can be mentioned.

The photopolymerization initiator may optionally contain a boron sensitizer, an oxygen scavenger, a chain transfer agent, and an organic peroxide.

In the above-mentioned photocurable putty composition (I), in order to improve the adhesion to the substrate and the overcoat layer, the workability, etc., further, if necessary, a fiber material such as cellulose acetate butyrate or nitrocellulose. It may contain a derivative, a non-reactive diluent, a thermoplastic resin, a phosphoric acid group-containing compound, a filler and the like.

Photocurable primer composition (II) Photocurable primer composition (II) used in the present invention
Is an acrylic resin (A) containing a polymerizable unsaturated group in a side chain through a urethane bond, a urethane (meth) acrylate oligomer (B) containing one or more polymerizable unsaturated groups in one molecule, and It contains a polymerization initiator (C).

The acrylic resin (A) containing a polymerizable unsaturated group in its side chain via a urethane bond is, for example, a method of reacting a hydroxyl group-containing acrylic resin with a compound having an isocyanate group and a polymerizable unsaturated group in one molecule. It is obtained by introducing a polymerizable unsaturated group into an acrylic resin by a method of reacting an isocyanate group-containing acrylic resin with a compound having a hydroxyl group and a polymerizable unsaturated group in one molecule. Examples of the polymerizable unsaturated group include a (meth) acryloyl group, a vinyl group, a vinyl ether group, an allyl group, and the concentration thereof is 0.2 to 2.0 mo in the solid content of the acrylic resin (A).
It is suitable that the content is 1 / kg, preferably 0.3 to 1.5 mol / kg.

The urethane (meth) acrylate oligomer (B) is added to improve adhesion and water resistance. For example, a compound containing two or more isocyanate groups in one molecule, a hydroxyl group-containing polymerization. Those obtained by the reaction with a polyunsaturated monomer and a monohydric alcohol can be preferably used.

The hydroxyl group-containing polymerizable unsaturated monomer is used for introducing a polymerizable unsaturated group into the urethane (meth) acrylate oligomer (B), and the monohydric alcohol is urethane (meth) acrylate. Oligomer (B)
It is used for the purpose of blocking the excess isocyanate groups of and the concentration of unsaturated groups. The amount of the polymerizable unsaturated group of the urethane (meth) acrylate oligomer (B) is 1.0 to 2.5 m in the solid content of the component (B).
It is preferably within the range of ol / kg.

As the photopolymerization initiator (C), the same ones as described for the photocurable putty composition (I) can be used.

The photocurable primer composition (II) preferably contains a polymerizable unsaturated compound as listed in the description of the photocurable putty composition (I). The photocurable primer composition (II) further contains an extender pigment, a fibrin derivative, a non-reactive diluent, a thermoplastic resin, a phosphate group-containing compound, a filler, resin particles and the like, if necessary. be able to.

In the present invention, the photocurable primer composition (II) is to be applied to the putty surface, and it is desirable that the putty layer be cured. However, from the viewpoint of process reduction, the photocurable putty composition is used. After coating the composition (I), the photocurable primer composition (II) may be coated on the surface of the coating film while it is uncured, and both coating surfaces may be simultaneously cured by irradiation with light.

When the wet-on-wet coating process is adopted as described above, the coating layers formed by the photocurable putty composition (I) and the photocurable primer composition (II) are both light rays. It is desirable that the photocurable putty composition (I) is 10 to 30% and the photocurable primer composition (II) is 10 to 40% in PVC (pigment volume concentration). Is preferred. Further, in these (I) and (II), it is preferable to contain an extender pigment having a high light transmittance as the pigment used. Examples of such extender pigments having high light transmittance include talc,
Examples thereof include mica, barium sulfate, kaolin, calcium carbonate, clay, silica, quartz and glass. Further, in this case, a filler and resin particles may be used in combination if necessary. Further, in this case, the photopolymerization initiator used in the compositions (I) and (II) is a compound that is excited at a long wavelength such as visible light or near infrared light in order to cure the coating film inside. preferable.

Colored Base Coating Composition (III) In the coating method of the present invention, the colored base coating composition (II
For I), organic solvent-based paints, water-based paints, etc. which are usually used for repair such as acrylic lacquer, urethane-curable paint, fluororesin paint, etc. can be used without particular limitation.

In the colored base layer, a coating film can be obtained by ordinary drying at room temperature and forced drying by heating. In the present invention, the colored base coating composition (III) is particularly used for shortening the repair process. After coating, it is desirable to apply the clear composition (IV) described below in an uncured state. In this case, as the colored base coating composition (III), a one-pack type composition is preferable, and a resin having an active hydrogen group and a composition containing a coloring pigment as a main component are particularly preferable.

Examples of the active hydrogen group contained in the resin include a hydroxyl group, a hydroxyphenyl group and an amino group.
In the present invention, a resin having a hydroxyl group is preferable because it has good curability and little coloring, and examples thereof include a hydroxyl group-containing acrylic resin, a hydroxyl group-containing polyester resin, a hydroxyl group-containing polyurethane resin, and a hydroxyl group-containing polyether resin. .

As the above-mentioned color pigment, an aluminum paste is used.
Examples thereof include bright pigments such as strike powder, pearl powder, graphite, MIO, titanium white, phthalocyanine blue, and carbon black. An extender pigment may be blended if necessary.

Further, if necessary, additives for paints such as a phosphoric acid group-containing acrylic resin, an ultraviolet absorber, a light stabilizer, an antioxidant, a surface conditioner, a pigment dispersant and a curing catalyst may be added. it can.

One-pack clear composition (IV) The clear composition (IV) used in the present invention is usually used for repairing acrylic lacquer, urethane curable paint, fluororesin paint, etc. 1 Although liquid type or two-component type paints can be used without limitation, the clear composition (I
As V), a one-pack type composition is preferable, and the following (1) to (3) are particularly preferable.

(1) A resin (a) containing at least one functional group selected from a siloxy group and an isocyanate group, a function selected from a siloxy group and an isocyanate group and contained in the resin (a). A one-pack type clear composition containing a compound (b) containing at least one functional group capable of reacting with a group, and a siloxy group dissociation catalyst (c).

(2) A resin (a) containing at least one functional group selected from siloxy groups and isocyanate groups, a function selected from siloxy groups and isocyanate groups and contained in resin (a). 1 containing a compound (b) containing at least one functional group capable of reacting with a group, a siloxy group dissociation catalyst (c), a polymerizable unsaturated group containing compound (d), and a photopolymerization initiator (e) Liquid clear composition.

(3) Resin (f) having a polymerizable unsaturated group and at least one functional group selected from a siloxy group and an isocyanate group, selected from a siloxy group and an isocyanate group. Liquid containing at least one functional group capable of reacting with the functional group contained in the resin (a), a siloxy group dissociation catalyst (c), and a photopolymerization initiator (e) Type clear composition.

The resin (a) containing at least one functional group selected from the siloxy group and the isocyanate group is usually selected from vinyl monomers having each of these reactive functional groups. It can be obtained by copolymerizing these with other vinyl-based monomers that can be copolymerized by a conventional method such as a solution polymerization method in the presence of a radical polymerization initiator. Specifically, a monomer mixture containing one or both of a siloxy group-containing vinyl monomer and an isocyanate group-containing vinyl monomer is copolymerized.

Typical examples of the siloxy group-containing vinyl monomer include, for example, trimethylsiloxyethyl (meth) acrylate, trimethylsiloxypropyl (meth) acrylate, trimethylsiloxybutyl (meth) acrylate, triethylsiloxyethyl (meth). )
Examples thereof include trialkylsiloxyalkyl (meth) acrylates such as acrylate, triethylsiloxypropyl (meth) acrylate, and triethylsiloxybutyl (meth) acrylate, but not limited to these, the hydroxyl group in the hydroxyl group-containing vinyl monomer is commonly known. Any compound can be used as long as it is a compound converted to a siloxy group with the silylating agent. That is, hydroxyethyl (meth) acrylate to which ε-caprolactone is added, polyoxyalkylene glycol (meth) acrylates converted into siloxy groups with a silylating agent such as trimethylchlorosilane and t-butyldimethylchlorosilane, respectively. Can also be used.

Typical examples of the isocyanate group-containing vinyl monomer include, for example, isocyanate ethyl (meth) acrylate, isocyanate propyl (meth) acrylate, and meta-isopropenyl-α, α-dimethylbenzyl isocyanate. However, the present invention is not limited to this, and an adduct of a hydroxyl group-containing vinyl monomer such as hydroxyethyl (meth) acrylate and a polyfunctional isocyanate compound such as isophorone diisocyanate can also be used.

Typical examples of other vinyl monomers copolymerizable with the above-mentioned vinyl monomer having a reactive functional group are, for example, vinyl aromatic compounds such as styrene, α-methylstyrene and vinyltoluene. Group compounds; methyl (meta)
Acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (n-, i-, t-) butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) Carbon number of acrylic acid or methacrylic acid such as acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate ~ 24 alkyl ester or cycloalkyl ester; methoxybutyl (meth) acrylate,
C2-C18 alkoxyalkyl esters of acrylic acid or methacrylic acid such as methoxyethyl (meth) acrylate and ethoxybutyl (meth) acrylate; (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, 2 -Carboxyl group-containing polymerizable unsaturated monomer such as carboxyethyl (meth) acrylate; epoxy group-containing polymerizable unsaturated monomer such as glycidyl (meth) acrylate; perfluorobutylethyl (meth)
Acrylate, perfluoroisononylethyl (meth)
Perfluoroalkyl (meth) acrylates such as acrylate and perfluorooctylethyl (meth) acrylate; CF2 = CF2, CHF = CF2, CH2 = CF
2, CClF = CF2 and other general formulas CX2 = CX2 (wherein X is the same or different and represents H, Cl, Br, F, an alkyl group or a haloalkyl group, provided that at least one F is contained in the formula. 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole, 4- (meth) acryloyloxy-1,2,2,
UV-absorbing or UV-stable polymerizable unsaturated monomers such as 6,6-pentamethylpiperidine; and polymers of one and / or more of these monomers at one end A so-called macromonomer having a copolymerizable double bond in the above is also mentioned as a monomer copolymerizable with the vinyl-based monomer having a reactive functional group. These can be appropriately selected and used according to the desired physical properties.

Examples of the solvent used in the solution polymerization of the above monomer mixture include alkylbenzene derivatives such as benzene, toluene and xylene; acetic acid ester solvents such as ethyl acetate, propyl acetate, amyl acetate, methoxybutyl acetate and cellosolve acetate. Ether solvents such as dioxane, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, and diethylene glycol diethyl ether; ketone solvents such as methyl isobutyl ketone. These can be used alone or in admixture of two or more.

As the radical polymerization initiator, benzoyl peroxide, di-t-butyl hydroperoxide, t-butyl hydroperoxide, cumyl peroxide,
Peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, t-butylperoxybenzoate, lauryl peroxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate; α, α′-azo Examples thereof include azo compounds such as bisisobutyronitrile, α, α′-azobis-2-methylbutyronitrile, azobisdimethylvaleronitrile and azobiscyclohexanecarbonitrile.

The resin (a) may further contain an alkoxysilyl group from the viewpoint of improving curability and acid resistance.
In order to contain the alkoxysilyl group, an alkoxysilyl group-containing vinyl monomer is further used as the copolymerization component.

Typical examples of the above-mentioned alkoxysilyl group-containing vinyl monomer include, for example, vinyltrimethoxysilane, vinyltriethoxysilane and γ- (meth).
Acryloyloxypropyltrimethoxysilane, γ-
(Meth) acryloyloxypropyldimethoxymethylsilane, γ- (meth) acryloyloxypropyltriethoxysilane, styrylethyltrimethoxysilane,
Examples thereof include vinyl tris (2-methoxyethoxy) silane and vinyl triacetoxy silane.

The resin (a) obtained by the usual radical solution polymerization method using the above vinyl-based monomer, solvent and polymerization initiator has a weight average molecular weight of 1,000 to 200,000.
It is preferably 0, more preferably 2,000 to 100,000. When the weight average molecular weight is less than 1,000, it is difficult to obtain a satisfactory drying property, and the weather resistance and durability of the resulting coating film tend to decrease. On the other hand, 20
If it is more than 10,000, the finished appearance is deteriorated, which is not preferable.

On the other hand, the resin (f) having a polymerizable unsaturated group and at least one functional group selected from a siloxy group and an isocyanate group is a polymerizable unsaturated group per molecule. At least one or more, preferably about 2
50, at least one or more functional groups selected from siloxy groups and isocyanate groups are averaged to about 2 to 1 per molecule.
Those containing about 100, preferably about 2 to about 50 are preferable. Usually, a vinyl monomer having a functional group is appropriately selected, and a monomer containing other vinyl monomer copolymerizable therewith is usually used. A monomer mixture, specifically, a monomer mixture containing one or both of a siloxy group-containing vinyl monomer and an isocyanate group-containing vinyl monomer as listed in the above resin (a). It can be obtained by introducing a polymerizable unsaturated group into a copolymer obtained by copolymerization by a conventional method such as a solution polymerization method in the presence of a radical polymerization initiator.

The polymerizable unsaturated group is not particularly limited as long as it causes a radical polymerization reaction by light having a wavelength of 300 nm, and specifically, it is a (meth) acryloyl group, a vinyl group or a vinyl ether group. , Allyl groups and the like. Among these, a (meth) acryloyl group is particularly preferable.

As a method for introducing the above-mentioned polymerizable unsaturated group,
A conventionally known method can be used without particular limitation. For example, a carboxyl group is introduced into a copolymerization component of the above copolymer by using a carboxyl group-containing polymerizable unsaturated monomer, and glycidyl (meth) acrylate is added thereto. Or an epoxy group is introduced into the copolymerization component of the above copolymer by using an epoxy group-containing polymerizable unsaturated monomer, and (meth) acrylic acid is added thereto, or the above copolymer is added. Has an isocyanato group, 2-hydroxyethyl (meth) acrylate or the like is added thereto, or when the above copolymer has a siloxy group (hydroxyl group), 2-hydroxyethyl is added thereto. An equimolar addition reaction product of ethyl (meth) acrylate or the like and a diisocyanate compound is added,
Among these, from the viewpoints of weather resistance and coating film physical properties, the siloxy group (hydroxyl group) in the copolymer is
A resin obtained by a method in which an equimolar addition reaction product of hydroxyethyl (meth) acrylate or the like and a diisocyanate compound is added is suitable.

The compound (b) containing at least one functional group selected from the siloxy group and the isocyanate group and capable of reacting with the functional group contained in the resin (a) is a low molecular weight compound or a resin. Alternatively, when the resin (a) has a siloxy group, it is a compound containing an isocyanate group or a resin containing an isocyanate group and a siloxy group, and when the resin (a) has an isocyanate group, it is a siloxy group. It is a group-containing compound or a resin containing a siloxy group and an isocyanate group. The compound (b) may be the same as the resin (a) when the resin (a) has both a siloxy group and an isocyanate group.

As the isocyanate group-containing compound used as the component (b), a polyisocyanate compound containing at least two isocyanate groups in one molecule can be used. Typical examples are tetramethylene diisocyanate, Aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; hydrogenated xylylene diisocyanates, 1,4-diisocyanates cycloaliphatic diisocyanates such as cyclohexane or isophorone diisocyanate; tolylene diisocyanate, 4,4 ′
-Organic diisocyanate itself such as aromatic diisocyanates such as diphenylmethane diisocyanate, or each of these organic diisocyanates and polyhydric alcohols,
Addition product with low molecular weight polyester or water, or a cyclized polymer of the above organic diisocyanates,
Further, an isocyanate / biuret body and the like can be mentioned. Further, as the component (b), a resin obtained by copolymerizing an isocyanate group-containing vinyl-based monomer with styrene, (meth) acrylic acid ester or the like can also be used.

From the viewpoint of scratch resistance and solubility in a solvent, the polyisocyanate compound is an adduct of diisocyanate and a long-chain polyhydric alcohol, for example, the above-mentioned diisocyanate and 10 to 30 carbon atoms. Polyols such as alkylenediols, polycaprolactone polyols, polyether polyols and polyester polyols
A polyisocyanate compound obtained by reacting a diisocyanate compound with a polycaprolactone diol and / or triol can be preferably used.

As the siloxy group-containing compound used as the above-mentioned component (b), a compound containing at least two siloxy groups in one molecule can be used. Specifically, it contains at least two hydroxyl groups in one molecule. Any compound can be used as long as it is a compound in which the hydroxyl group of the compound is converted into a siloxy group by a known and commonly used silylating agent. Typical of these compounds are, for example, ethylene glycol, propylene glycol, 1,2-butanediol,
Dihydric alcohols such as 1,3-butanediol and 2,3-butanediol; polylactone diols obtained by adding lactones such as ε-caprolactone to these dihydric alcohols; glycerin, trimethylolpropane, pentaerythritol And other trihydric alcohols; polylactone polyols obtained by adding lactones such as ε-caprolactone to these trihydric or higher alcohols with silyl groups such as trimethylchlorosilane and t-butyldimethylchlorosilane. And the like. Further, as the component (b), the siloxy group-containing vinyl-based monomer listed in the description of the resin (a) is copolymerized with other vinyl-based monomers such as styrene and (meth) acrylic acid esters. The resulting resin can also be used.

As the siloxy group- and isocyanate group-containing resin used as the component (b), the siloxy group-containing vinyl type monomer and the isocyanate group-containing vinyl type monomer listed in the explanation of the resin (a) are used. The thing obtained by copolymerizing a monomer and these and other vinyl type monomers copolymerizable with them by a conventional method can be used.

The component (b) may further contain an alkoxysilyl group from the viewpoint of improving curability and acid resistance.
In order to contain the alkoxysilyl group, the alkoxysilyl group-containing vinyl-based monomer listed in the description of the resin (a) is further used as the copolymerization component.

In the present invention, in particular, as the component (a), a resin containing two or more siloxy groups in one molecule,
From the practical viewpoint, it is appropriate to select a polyisocyanate compound as the component (b).

The siloxy group content in the above-mentioned components (a) and (b) is the composition amount as the siloxy group-containing vinyl monomer and compound in both components, and the solid content is 5 to 60% by weight.
Further, it is preferably in the range of 10 to 50% by weight. If it is less than 10% by weight, the crosslink density of the coating film tends to be low, and the physical properties of the coating film tend to deteriorate. On the other hand, if the amount is more than 60% by weight, further improvement in performance cannot be expected.

The siloxy groups in the components (a) and (b) are hydrolyzed by water in the air after coating to form hydroxyl groups. Therefore, the composition amount as the isocyanate group-containing vinyl monomer and compound in the components (a) and (b) is such that the hydroxyl groups formed from the isocyanate group and the siloxy group have an equivalent ratio of NCO / OH = 0.5. It is preferable to be in the range of 2.0.

The siloxy dissociation catalyst (c) promotes hydrolysis of siloxy groups by water in the air after coating to form hydroxyl groups. For example, phosphoric acid and its acid ester, phosphorous acid. Esters; sulfonic acids such as paratoluenesulfonic acid and naphthalenedisulfonic acid and amine salts thereof; carboxylic acids such as trichloroacetic acid and trifluoroacetic acid, and acidic compounds such as amine salts thereof.

The siloxy group dissociation catalyst (c) is added in an amount of 0.01 to 1 with respect to the solid content of the resin composition in the coating material.
It is preferably in the range of 0% by weight, more preferably 0.1 to 5% by weight. If it is less than 0.01% by weight, the curability is lowered, and if it is more than 10% by weight, the water resistance of the coating film tends to be poor.

The above polymerizable unsaturated group-containing compound (d) is
Any conventionally known one can be used without limitation, and specifically, it can be appropriately selected and used from among those listed in the description of the photocurable putty composition.

The amount of the polymerizable unsaturated group-containing compound (d) used is 5 with respect to 100 parts by weight of the total resin solid content in the coating material.
It is desirable to be in the range of ˜90 parts by weight, preferably 5 to 80 parts by weight. If the amount used is less than 5 parts by weight, the rapid drying property due to photo-curing of the obtained coating film becomes insufficient, and if it exceeds 90 parts by weight, the volume shrinkage of the coating film becomes large and the adhesion and physical properties of the coating film deteriorate. Is not desirable.

As the above-mentioned photopolymerization initiator (e), conventionally known ones can be used without limitation, and concretely, it can be appropriately selected and used from among those listed in the description of the above-mentioned photocurable putty composition.

The amount of the photopolymerization initiator (e) blended is 0.01 to 10% by weight based on the solid content of the resin composition in the coating material.
The range of is suitable.

In the above one-pack type clear composition (IV), if necessary, a curing catalyst such as a urethanization catalyst, a water binder,
A fibrin derivative, a non-reactive diluent, a thermoplastic resin, an antiblocking agent, an organic solvent, an ultraviolet absorber, a light stabilizer, a coating surface adjusting agent, an antioxidant, a flow adjusting agent and the like can be appropriately contained.

The above one-pack type clear composition (IV) can also be made into an aerosol paint by adding a propellant to the above paint component and filling the paint component together with the propellant into an aerosol container. . The propellant may be a known dimethyl ether.
Tellurium, LP gas and the like can be used alone or in combination.

Coating In the coating method of the present invention, examples of the substrate surface include metal surfaces such as iron, zinc, and aluminum, chemically treated surfaces thereof, plastics, wood, and the like, and old coating surface coated on these. To be When the surface to be coated is a damaged portion, it is appropriate to perform sanding around the damaged portion as necessary to the periphery thereof. The sanded damaged part is treated with the photocurable putty composition (I). The treatment method can be appropriately selected depending on the state of the damaged portion, and the photocurable putty composition (I) is adjusted to the coating viscosity with the polymerizable unsaturated compound as described above and sprayed on the damaged portion. And a method of filling the damaged portion with the above photocurable putty composition (I) by spatula attachment or the like.

The surface of the putty thus obtained may be cured by irradiation with light, or the photocurable primer composition (II) may be applied in an uncured state and both layers may be simultaneously cured by irradiation with light. Good.

As the light source to be used, conventionally known light sources can be used without limitation. Specific examples thereof include halogen lamps, xenon lamps, krypton lamps, metal halide lamps, fluorescent lamps, sunlight, semiconductor lasers, and light emitting diodes. Irradiation conditions can be appropriately selected depending on the thickness and composition of the treatment layer.

The photocurable primer composition (II) can be coated by a conventionally known method such as a sprayer, roll coater, gravure coater, screen, etc. You may spray-paint by adjusting. The primer coating film has a dry film thickness of 30 to 500 μm, preferably 5
It is in the range of 0 to 300 μm. The primer coating film that has been cured by irradiation with light is polished as necessary and then used for top coating.

The coating of the colored base coating composition (III) comprises
It can be carried out by a conventionally known method such as a sprayer, roll coater, gravure coater and screen, and spray coating may be carried out by adjusting the coating viscosity. The resulting colored base coating film has a dry film thickness in the range of 5 to 100 μm, preferably 5 to 50 μm. In the present invention, after coating the colored base coating composition from the viewpoint of shortening the process and improving the adhesiveness, the clear composition (IV) is left uncured on the coated surface.
However, the colored base coating film may be dried or forcedly dried by heating if necessary.

The clear composition (IV) is coated, for example, by
It can be carried out by a conventionally known method such as a sprayer, roll coater, gravure coater and screen, and spray coating may be carried out by adjusting the coating viscosity.

The clear coating film obtained is one which is cured by heating or light irradiation depending on its composition. Specifically, the clear composition (IV) is heat-dried in the one-pack type clear composition (1), Clear composition (IV)
When the one-part clear composition (2) or (3) is irradiated with light, both coating films can be simultaneously cured when the colored base coating film is uncured. The thickness of the clear coating film is 10 to 200 μm, preferably 30 to 1 as a dry film thickness.
The range of 00 μm is preferable.

In the case of heat drying, usually 50 to 100 ° C.
Can be heated for 10 to 60 minutes, and in the case of light irradiation, as the light source used for light irradiation, those listed above can be used, and the irradiation conditions are the thickness of the clear film or the colored base film and It can be appropriately selected depending on the composition and the like.

[0068]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. Hereinafter, "parts" and "%" are based on weight unless otherwise specified.

Production of Photocurable Putty Composition Production Examples 1 and 2 Each composition was blended according to the formulation shown in Table 1 below, and then sequentially added and dispersed and mixed with stirring to produce each putty composition (PT1), (PT
2) was obtained. As a putty composition (PT3), "LU
C poly putty "(Kansai Paint Co., Ltd., unsaturated polyester resin type room temperature curing type two-part type putty composition) was used. Table 2 shows the pot life and polishable dry time (including light irradiation time) of these compositions. (Note 1) "SP-1507": Showa Polymer Co., Ltd., acrylate group-containing epoxy resin (Note 2) "SP-5003": Showa Polymer Co., Ltd., acrylate group-containing epoxy resin (Note 3) N, N, 2,4,6-Pentamethylaniline: Chain transfer agent

[0070]

[Table 1]

[0071]

[Table 2]

Acrylic tree for photocurable primer composition
Production of fats Production Examples 3 to 7 A reactor was equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, a dropping pump, and a blow-in tube for dry air, 50 parts of xylene was charged, and the temperature was raised to 115 ° C with stirring. While maintaining the mixture of the monomer and the polymerization initiator shown in Table 3 below at 115 ° C., the mixture was added dropwise at a constant rate over 3 hours using a dropping pump. 1.5 hours after completion of dropping 110
℃, then azobisisobutyronitrile 0.5
What was dissolved in 10 parts of xylene was added dropwise at a constant rate over 1.5 hours, and the temperature was kept at 110 ° C. for 3 hours, and stirring was continued. Then, 25 parts of xylene was added and the mixture was cooled to 80 ° C. while being diluted. Subsequently, while supplying dry air to the liquid phase, 0.06 part of hydroquinone monomethyl ether as a polymerization inhibitor, 0.06 part of dibutyltin dilaurate as a urethanization catalyst, and an unsaturated group-introducing component having the composition shown in Table 3 were used. , 14 parts of xylene and 80 ° C for 7 hours
And the addition reaction was completed to obtain acrylic resin solutions (A1) to (A5) for the primer composition.

[0073]

[Table 3]

Production of Urethane Acrylate Oligomer Production Examples 8 to 10 A reactor was equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, a dropping pump, and a blow-in tube for dry air, and an isocyanate compound having the formulation shown in Table 4 and xylene 26 were prepared.
Parts, polymerization inhibitor hydroquinone monomethyl ether 0.
47 parts, urethanization catalyst dibutyltin dilaurate 0.4
7 parts were charged, and the temperature was raised to 80 ° C. with stirring while supplying dry air to the liquid phase. Subsequently, a mixture of a hydroxyl group-containing polymerizable unsaturated monomer having a composition shown in Table 4 and a monohydric alcohol was added dropwise at a constant rate over 3 hours while maintaining the temperature at 80 ° C., and then 5 The temperature was kept at 80 ° C. for an hour to complete the addition reaction, and 216 parts of isopropanol was added and the mixture was cooled while being diluted to obtain urethane (meth) acrylate oligomer solutions (B1) to (B3). (Note 4) "N-3
300 ”: trade name, manufactured by Sumika Bayer Urethane Co., solid content 100%, hexamethylene diisocyanate-based polyisocyanate

[0075]

[Table 4]

Production of Photocurable Primer Composition Production Examples 11 to 16 An acrylic resin solution, a urethane acrylate oligomer solution, isobornyl acrylate, a pigment and xylene are blended in the blending composition shown in Table 5 below, followed by mixing and stirring. After adding glass beads with a diameter of 1.5 mm, batch sand 2
After the dispersion for 0 minutes, the phosphoric acid monomer and the photopolymerization initiator were added thereto, and the mixture was stirred and viscous with xylene for about 20 seconds (Ford cup # 4/20 ° C.) to obtain a primer composition (PR1). (PR6) was obtained. As the two-component primer composition, "JUST Urethane Prasaf" (Kansai Paint Co., Ltd., acrylic urethane resin-based two-component primer) was used. Table 6 shows the pot life and polishable dry time (including light irradiation time) of these compositions.

(Note 5): "Kayamer PM-21": manufactured by Nippon Kayaku Co., Ltd., unsaturated group-containing phosphoric acid monomer (Note 6): "Irgacure 819": manufactured by Ciba Specialty Chemicals, bis (2, 4, 4) 6-trimethylbenzoyl) -phenylphosphine oxide (Note 7) "Microace L-1": manufactured by Nippon Talc Co., Ltd., talc (Note 8) "precipitable barium sulfate 100": manufactured by Sakai Chemical Industry Co., Ltd.

[0078]

[Table 5]

[0079]

[Table 6]

Preparation of Colored Base Paint "Retan PG Hybrid Primary Color No. 835" (Kansai Paint Co., Ltd., colored base paint containing a hydroxyl group-containing acrylic resin as the main resin component) was used as "PG Hybrid Thinner 20".
What was diluted and viscous for 11 to 12 seconds (Ford cup # 4/25 ° C) was used as a one-pack type colored base paint.

Production of Clear Acrylic Resin Production Examples 17 and 18 A reactor was equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, a dropping pump and a blow-in tube for dry air. After the temperature was raised to 0 ° C, 1 part of the mixture of the monomer and the polymerization initiator shown in Table 7 was added.
While maintaining the temperature at 15 ° C., the solution was added dropwise at a constant rate over 3 hours by using a dropping pump. After the dropping was completed, the temperature was maintained at 110 ° C. for 1.5 hours, and then a solution prepared by dissolving 0.5 parts of azobisisobutyronitrile in 10 parts of xylene was added dropwise at a constant rate over 1.5 hours. The temperature was kept at 0 ° C. and stirring was continued to complete the polymerization reaction. Then, 25 parts of xylene was added and the mixture was diluted and cooled to 80 ° C. to obtain an acrylic resin solution (C1) for one-pack type clear. Following the same operation as described above, hydroquinone monomethyl ether 0.06 was added as a polymerization inhibitor while supplying dry air to the liquid phase.
Part, dibutyltin dilaurate as a urethanization catalyst.
06 parts, an equimolar adduct of isophorone diisocyanate and hydroxyethyl acrylate having the composition shown in Table 7, and 14 parts of xylene were added and the addition reaction was carried out at 80 ° C. for 7 hours to obtain a clear acrylic resin solution (C2). .

[0082]

[Table 7]

Production of Clear Composition Production Examples 19 to 21 Acrylic resin solutions for clear, polyisocyanate compounds (Note 9), diisopropyl phosphate (siloxy group dissociation catalyst), dibutyltin dilaurate having the composition shown in Table 8 below. (Urethane-forming catalyst), trimethyl orthoacetate (water-binding agent), urethane acrylate (Note 10), isobornyl acrylate, and photopolymerization initiator (Note 11)
Was blended, stirred with a disper, and mixed with "PG hybrid thinner 20" for 13 to 14 seconds (Ford cup # 4 /
It was diluted and viscous at 25 ° C.) to obtain 1-pack type clear coating compositions (CR1) to (CR3). As the two-pack type clear composition, "PG Multi Clear HX (Q)" (Kansai Paint Co., Ltd., acrylic urethane resin two-pack type clear) was used. Table 9 shows the pot life and drying time (including light irradiation time) of these compositions.

(Note 9) "TPA-100": Asahi Kasei Corporation, trade name, hexamethylene diisocyanate polyisocyanate (Note 10) "CN983": Sartomer, trade name,
Urethane acrylate oligomer (Note 11) "IRGACURE-184": Ciba Specialty Chemicals, trade name, 1-hydroxy-cyclohexyl-phenyl ketone

[0085]

[Table 8]

[0086]

[Table 9]

Coating Example 1 A mild steel plate (90 × 150 × 0.8 mm) was coated with the putty composition (PT1) obtained in the above Production Example with a spatula to give a “square light” (Ushio Lighting). 2 with an irradiation distance of 20 cm using a metal halide lamp manufactured by the company
Irradiated for minutes. After lightly polishing the putty surface obtained, spray coating the primer composition (PR1) obtained in the above Production Example to a dry film thickness of about 50 to 100 μm, and then irradiating with a “square light” 2 at 20 cm
It was irradiated and cured for a minute. The obtained primer surface is # 60
After lightly sanding with 0 water resistant paper, a 1-pack type colored base paint viscous as described above was spray-coated to a dry film thickness of 15 μm, and left at room temperature (about 20 ° C.) for 5 minutes. The clear composition (CR1) obtained in the above Production Example was spray coated on the surface of the base coating film so that the dry film thickness was 40 μm, and dried by heating at 60 ° C. for 20 minutes to cure both coating film surfaces. A test coated plate was obtained.

Examples 2 and 3 and Comparative Example 1 A test coated plate was prepared in the same manner as in Example 1 except that each composition used was as shown in Table 10 below.

Example 4 The putty composition (PT2) obtained in the above Production Example was applied to a mild steel plate (90 × 150 × 0.8 mm) with a spatula to a thickness of 5 mm, and the above Production Example was applied to the coated surface. Spray-coat the primer composition (PR4) obtained in step 1 to a dry film thickness of about 50 to 100 μm, and then apply “Square Light”.
(Ushio Lighting Co., Ltd., metal halide lamp) was irradiated for 2 minutes at an irradiation distance of 20 cm to cure both coating film surfaces. After lightly polishing the obtained primer surface with # 600 waterproof paper, spray-coat the one-component type colored base paint viscous as described above to a dry film thickness of 15 μm, and leave it at room temperature (about 20 ° C.) for 5 minutes. did. The one-pack type clear composition (CR2) obtained in the above Production Example was spray-coated on the base coated surface so that the dry film thickness was 40 μm, and the irradiation was performed with a “square light” at an irradiation distance of 20 cm for 10 minutes. A test coated plate was prepared by drying and curing both coating surfaces.

Example 5 Each coating composition used in Example 4 is shown in Table 10 below.
In addition, as shown in the above, and for the curing of the putty layer and the primer layer and the curing of the base layer and the clear layer, both of "Square Light" are changed to "Prisma Light" (Halogen lamp manufactured by Coke Co., Ltd.) and the irradiation distance is 50 cm. 10 for each condition
A test coated plate was prepared in the same manner as in Example 4 except that the test coated plate was dried for a minute.

Comparative Example 2 On a mild steel plate (90 × 150 × 0.8 mm), "LUC poly putty" (manufactured by Kansai Paint Co., unsaturated polyester resin type room temperature curing type two-component putty base agent) was used immediately before use. 2% of "LUC putty common curing agent" (Kansai Paint Co., Ltd., organic peroxide type compound) was blended, and this putty composition was applied with a spatula to a thickness of 5 mm, and polishing at 20 ° C was possible. Dried until. Then "JUST Urethane Plastic Surface" (Kansai Paint Co., Ltd., acrylic urethane resin type 2
20% of "JUST Urethane Plasaf Curing Agent" (manufactured by Kansai Paint Co., Ltd.) in the liquid type primer
2 "Retan PG2K thinner" (made by Kansai Paint Co., Ltd.)
0% is blended, and this primer composition is dried at a film thickness of 50 to
Spray coating was performed so that the thickness was about 100 μm, and forced drying was performed at 60 ° C. until polishing was possible. The primer surface thus obtained was lightly polished with # 600 waterproof paper, and the one-pack type colored base paint viscous as described above was dried to a film thickness of 15 μm.
Spray coating was carried out so as to obtain the above temperature, and the mixture was left at room temperature (about 20 ° C.) for 5 minutes. Immediately before using "PG Multi-Clear HX (Q)" on the base coated surface, a clear composition was prepared in which 50% of "PG Multi-Clear HX Standard Curing Agent" and 20% of "PG Hybrid Thinner 20" were mixed with the main agent. Spray paint the dry film thickness to 40μm,
It was dried at 60 ° C. for 20 minutes.

Evaluation Test Each test coated plate obtained above was evaluated according to the following criteria. The results are shown in Table 10.

(* 1) Total drying time: The total heating and light irradiation time (minutes) in each step is shown.

(* 2) Adhesion: In the process of preparing each test coated plate, after coating the clear composition with a lamp or forced drying and leaving it at 20 ° C. for 24 hours, the test coated plate was reached with a knife until it reached the substrate. Incisions were made to form 100 Goban stitches at 2 mm intervals, and an adhesive tape was applied thereon, and the number of Goban stitches left on the coated surface when the tape was rapidly peeled off was evaluated according to the following criteria. ◯: The number of burrs left on the coated surface was 100, and ×: The number of burred holes remaining on the coated surface was 99 or less.

(* 3) Initial Pencil Hardness: In the process of preparing each test coated plate, the pencil hardness of the coating film surface after being irradiated with a lamp after being coated with a clear paint or forcedly dried and then left at 20 ° C. for 2 hours is JIS K. -5400 8.4.2 (1990)
It was measured based on. The evaluation was broken.

(* 4) Finishing property: In the process of preparing each test coated plate, after clear coating, after irradiation with a lamp or forced drying, the surface was visually observed after standing for 24 hours at 20 ° C. based on the following criteria. evaluated.

⊚: Very good, ◯: Good, Δ: Slightly distorted on coated surface, ×: Slightly distorted on coated surface.

(* 5) Water resistance: Each test coated plate was immersed in tap water for 7 days, and then the state of the coated surface (generation of blister) was observed, and the same test and bending test as the above adhesion test were conducted. . For the bending test, each test coated plate should be 90 degrees from the center.
It was bent into a ° angle and the state of the bent portion was visually observed.

Coating surface condition (◯: good, Δ: partial blister)
Occurrence, x: Blistering on the entire surface) Adhesiveness (○: No peeling, Δ: Partial peeling, ×: Peeling on the entire surface) (: Peeling between base material and putty, peeling between putty and primer, primer ~ Peeling between colored bases) Bending test (○: good, △: slightly peeling, x: peeling) (: peeling between base material and putty, peeling between putty and primer, peeling between primer and colored base)

[0100]

[Table 10]

[0101]

EFFECTS OF THE INVENTION According to the method of the present invention, a one-pack type photocurable composition having fast curing property is used as a composition used in the undercoating step, and each one-pack type composition is used in the top coating step. By using, it is easy to handle, the time for measuring and mixing the paint can be omitted, and the time required for the entire painting process can be greatly reduced. In addition, since the wet-on-wet coating is possible between the putty filling / primer layer and the colored base layer / clear layer, the process time can be further shortened, and the formed coating film has good curability. ,
It has excellent adhesion between the layers.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) C09D 7/12 C09D 7/12 133/00 133/00 175/04 175/04 175/14 175/14 201 / 02 201/02 (72) Inventor Hajime Yushima 5-24-15 Higashiooi, Shinagawa-ku, Tokyo Kansai Paint Co., Ltd. F-term (reference) 4D075 AE12 AE17 BB26Z BB42Y BB42Z BB46Y BB46Z BB48Y BB48Z CA02 CA13 CA38 CA44 CB06 DA06 DA27 DB02 DB05 DB07 DB21 DB31 DC11 DC15 EA14 EA21 EA41 EA43 EB07 EB12 EB14 EB16 EB20 EB22 EB33 EB35 EB36 EB37 EB38 EB42 EC07 EC11 EC37 EC60 4J038 GA15 FA17 GA07 GA15 GA03 GA15 FA08 GA17 GA15 GA08 GA17 GA15 GA08 GA17 GA15 GA08 GA17 GA15 FA08 GA17 GA15 FA08 GA11 GA16 FA08 GA17 GA15 FA08 GA17 GA15 FA08 GA17 GA15 FA08 GA11 GA16 FA08 GA17 GA15 FA08 GA11 GA16 FA08 GA17 GA15 FA08 GA17 GA15 FA08 GA11 GA16 FA08 GA17 GA15 FA08 GA11 GA15 FA08 GA11 GA16 FA08 GA17 GA15 FA08 GA11 GA15 FA08 GA11 GA16 FA08 GA17 GA15 FA08 GA17 GA15 FA08 GA11 GA16 FA07 GA03 FA08 GA11 GA16 FA08 GA17 GA12 FA11 GA11 FA than GA2

Claims (8)

[Claims] 1. A photocurable putty composition (I) is applied to the surface of an object to be coated, and then an acrylic resin (A) containing a polymerizable unsaturated group in its side chain via a urethane bond, 1). 1 in the molecule
A urethane (meth) acrylate oligomer (B) containing one or more polymerizable unsaturated groups and a photocurable primer composition (II) containing a photopolymerization initiator (C) are applied, and after irradiation with light, A coating method, which comprises sequentially coating a colored base coating composition (III) and a clear composition (IV) on the above. 2. The coating method according to claim 1, wherein each of the colored base coating composition (III) and the clear composition (IV) is a one-pack type. 3. A clear composition (IV) selected from (a) a resin containing at least one functional group selected from a siloxy group and an isocyanate group, and (b) selected from a siloxy group and an isocyanate group. A one-pack type clear composition comprising a compound containing at least one functional group capable of reacting with the functional group contained in the resin (a), and (c) a siloxy group dissociation catalyst. Or the coating method according to 2. 4. The clear composition (IV) is selected from (a) a resin containing at least one functional group selected from a siloxy group and an isocyanate group, and (b) selected from a siloxy group and an isocyanate group. A compound containing at least one functional group capable of reacting with the functional group contained in the resin (a), (c) siloxy group dissociation catalyst, (d) polymerizable unsaturated group-containing compound, and (e) Contains a photopolymerization initiator 1
The coating method according to claim 1 or 2, which is a liquid type clear composition. 5. A resin (b), wherein the clear composition (IV) has (f) a polymerizable unsaturated group and at least one functional group selected from a siloxy group and an isocyanate group. ) A compound containing at least one functional group selected from a siloxy group and an isocyanate group and capable of reacting with the functional group contained in the resin (a), (c) a siloxy group dissociation catalyst, and (e) light. The coating method according to claim 1 or 2, which is a one-pack type clear composition containing a polymerization initiator. 6. A coating layer made of the photocurable putty composition (I) and a coating layer made of the photocurable primer composition (II) formed on the coating surface are irradiated with a light beam to both. The coating method according to claim 1, wherein the coating surface is simultaneously cured. 7. A colored base coating composition (III) is applied,
The coating method according to claim 3, wherein the clear composition (IV) is coated on the surface of the coating film and both coating surfaces are simultaneously cured by heating. 8. A colored base coating composition (III) is applied,
The coating method according to claim 4 or 5, wherein the clear composition (IV) is applied onto the surface of the coating film, and both surfaces of the coating film are simultaneously cured by irradiation with light rays.