JP2002285044A - Thermosetting coating composition and coating film forming method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting coating composition having an organic solvent of a little amount, a method for forming a coating film and a method for forming multilayer coating film by using the same. SOLUTION: This thermosetting coating composition includes a component (a) represented by general formula 1 having a number-average molecular weight of 300-3000 and active methylene group (wherein, R<1> is a polyol residue; R<2> is H, a 1-30C organic group; R<3> is OH, a 1-6C organic group except an epoxy group, a component (b) having a number-average molecular weight of 200-3,000 and (meth)acrylate groups of more than two in one molecule, a component (c) having an onium group and a component (d) having an epoxy group and/or carbonate group of five-membered ring. The component c and/or the component d include(s) resin particles which are insoluble in an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting coating composition suitable as a top coating for automobile bodies and parts, a method for forming a coating film using the same, and a method for forming a multilayer coating film.

[0002]

2. Description of the Related Art A Michael addition reaction between a polarized double bond such as an α, β-unsaturated carbonyl group and an active methylene group or a hydroxyl group does not generate a reaction by-product and the bond formed is chemically changed. It is applied to the crosslinking of a curable resin composition such as a paint, since it is a stable bond. As typical examples, JP-A-1-121341 and JP-A-2-500
No. 282, Japanese Unexamined Patent Publication No. Hei 4-222879 and the like are disclosed.

[0003] Generally, in the Michael addition reaction, a strong base is used to generate a carbanion from an active hydrogen site. Many prior arts utilizing the Michael addition reaction to crosslink resins also use strong bases such as, for example, alkali metal hydroxides and alkoxides, quaternary ammonium hydroxides, tertiary amines, guanidines, amidines and tertiary phosphines. Used as a catalyst.

[0004] However, such a strong basic catalyst has a problem that it causes hydrolysis and the like to deteriorate the resin, and that the strong basic catalyst remains in the obtained coating film, thereby deteriorating the appearance and quality. there were.

[0005] JP-A-7-173262 and JP-A-Hei-1
In order to solve the drawbacks of strong basic catalysts, onium salts such as neutral quaternary ammonium salts which exhibit no or little catalytic activity by themselves are disclosed in the co-existence of epoxy groups. Below, a combined catalyst system for use as a catalyst in a Michael addition reaction is disclosed. Since these catalysts are neutral, the above-mentioned problems of the strongly basic catalyst can be improved.

[0006] On the other hand, in recent years, there has been a strong demand for reduction of volatile organic components contained in paints, particularly due to environmental problems. The most frequent volatile organic component contained in the paint is an organic solvent used for diluting the paint to an applicable viscosity at the time of application. In order to reduce the amount of the organic solvent used, it is generally necessary to lower the viscosity of the paint, and specifically, a method of reducing the molecular weight or a method of reducing the polarity of the resin contained in the paint is employed. .

In order to obtain good coating film quality using a coating composed of a low molecular weight resin, it is necessary to increase the amount of catalyst and the concentration of functional groups to increase the curing reaction rate during heat curing. As a result, even with the above-mentioned catalyst system using a combination of a neutral onium salt and an epoxy group, satisfactory curability has not yet been obtained, and further improvement in quality such as durability has been desired.

Further, Japanese Patent Publication No. 6-62743 discloses that
As a compound having an active methylene group, a malonic acid oligomer or a malonic acid polymer is disclosed. However, since this malonic acid oligomer or polymer has a hydroxyl group or an epoxy group which is a polar functional group at the terminal ester group of malonic acid, the malonic acid oligomer or polymer is not sufficient for lowering the polarity of the oligomer or polymer. It was not possible to reduce the amount of the organic solvent used in the coating.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to a thermosetting coating composition containing a very small amount of an organic solvent in a coating composition capable of obtaining sufficient curability and good coating film quality, and using the same. A method for forming a coating film and a method for forming a multilayer coating film are provided.

[0010]

According to the present invention, there is provided a compound represented by the following general formula 1: having a number average molecular weight of 300 to 3000 and having an active methylene group or an active methine group.

[0011]

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And / or general formula 2:

[0013]

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(Wherein, R ¹ is an organic residue of a polyol, R ² is a hydrogen atom or an organic group which may contain an oxygen atom having 1 to 20 carbon atoms, and R ³ is a carbon atom. Represents an organic group not containing 1 to 6 hydroxyl groups and epoxy groups, m is 2 or more, and n is 1 or more, and a plurality of R ² and R ³ may be the same or different. )), Having a number average molecular weight of 2
Component (b) having two or more methacrylate groups and / or acrylate groups in one molecule, component (c) having an onium salt, and having an epoxy group and / or a 5-membered ring carbonate group in one molecule. In the thermosetting coating composition containing the component (d), the component (c) is a non-aqueous dispersion (c-1) containing resin particles insoluble in an organic solvent having an onium salt, and / or
A thermosetting coating composition, wherein the component (d) contains a non-aqueous dispersion (d-1) containing resin particles insoluble in an organic solvent having an epoxy group and / or a 5-membered carbonate group. Things.

The component (a) is preferably one obtained from malonic acid, a malonic ester compound, a malonic acid derivative or an ester compound of a malonic acid derivative and a polyol, and the component (a) The chemical structure of R ¹ is preferably one having an alicyclic moiety in a linear or side chain. Component (b) is a (meth) acrylate ester of polyol, polyester (meth)
Acrylate resin, unsaturated polyester resin, epoxy (meth) acrylate resin, urethane (meth) acrylate resin, α, β-unsaturated carbonyl group-containing acrylic resin, polyether (meth) acrylate resin, and (meth) acrylate group-containing silicone It is preferably at least one selected from the group consisting of resins.

The cation of the onium salt contained in the component (c) is at least one of a tertiary sulfonium cation, a quaternary phosphonium cation, and a quaternary ammonium cation. Preferably, it is at least one of a rate, a sulfonate, a sulfate, a nitrate or a phosphate.

Further, the non-aqueous dispersion (c-1) and / or the non-aqueous dispersion (d-1) may have a solid content of 40% by weight or more and a viscosity at 20 ° C. of 10,000 mPa · s or less. preferable. Here, the total content of the non-aqueous dispersion (c-1) and / or the non-aqueous dispersion (d-1) is based on the total weight of the component (a) and the component (b). It is preferably from 10 to 150% by weight as a basis.

Further, it may further contain an isocyanate compound, a melamine resin or tris (alkoxycarbonylamino) triazine. Also, the present invention
In the method for forming a coating film for applying the thermosetting coating composition to an object to be coated, the coating solid content of the thermosetting coating composition at the time of the application is 50% by weight or more. This is a method for forming a coating film.

Further, the present invention provides a step (1) of applying a base paint on an object to be coated with an electrodeposition coating film and an intermediate coating film to form an uncured base coating film, Step (2) of applying a clear paint on the uncured base coating film obtained in (1) to form an uncured clear coating film, and the uncured film obtained in the above steps (1) and (2) A method for forming a multilayer coating film comprising a step (3) of simultaneously heating and curing a base coating film and a clear coating film to obtain a coating film, wherein the clear coating material at the time of application is the thermosetting coating material. A method for forming a multi-layer coating film, which is a composition and has a coating solid content of 50% by weight or more.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTIONThermosetting coating composition  Component (a) contained in the thermosetting coating composition of the present invention includes:
Formulas 1 and 2 having an active methylene group or an active methine group
And / or represented by the general formula 2,
For example, compounds derived from malonic acid or malonic acid derivatives,
Resins can be mentioned.

The above R ¹ is an organic residue of a polyol.
As the above polyol, specifically, ethylene glycol, diethylene glycol, propylene glycol,
Tetramethylene glycol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, glycerin, pentaerythritol, 1,4-cyclohexanedimethanol, 4,4′-isopropylidenedicyclohexanol, bis (hydroxymethyl) tricyclo [ 5,2,1,0] decane, 1,3,5-tris (2-hydroxyethyl) cyanuric acid, isopropylidenebis (3,4-cyclohexanediol), and ethylene oxide, propylene oxide or caprolactone thereof. Examples include compounds such as adducts, and polymers such as acrylic polyol, polyester polyol, polyether polyol, epoxy polyol, polyurethane polyol, and silicone polyol. From the viewpoint of lowering the polarity of the obtained component (a), the polyol is preferably one having an alicyclic moiety in a linear or side chain, for example, 1,4-cyclohexanedimethanol, 4,4′-isopropylpropane. Copolymerized redidene dicyclohexanol, bis (hydroxymethyl) tricyclo [5,2,1,0] decane, isopropylidenebis (3,4-cyclohexanediol), cyclohexyl (meth) acrylate, norbornyl (meth) acrylate, etc. Acrylic polyols can be mentioned.

R ² is an organic group which may contain a hydrogen atom or an oxygen atom having 1 to 20 carbon atoms;
For example, a hydrogen atom, a methyl group, an ethyl group, a propyl group,
Alkyl groups such as a butyl group, a hexyl group, a cyclohexyl group, an octyl group, a 2-ethylhexyl group, a lauryl group, and a stearyl group; —CH ₂ —CHR ⁴ —COOR ⁵
(R ⁴ is a hydrogen atom or a methyl group, R ⁵ is the above-mentioned alkyl group) and the like.

R ³ is an organic group having 1 to 6 carbon atoms and excluding a hydroxyl group and an epoxy group. Examples of the group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t. Alkyl groups such as -butyl group, pentyl group, isopentyl group, 2-ethylpropyl group, hexyl group, isopentyl group, 2-ethylpentyl group, 2-methoxyethyl group, 2-methoxypropyl group, 3-methoxypropyl group , A 4-methoxybutyl group,
2-ethoxyethyl group, 2-ethoxypropyl group, 3-
Examples thereof include alkoxyalkyl groups such as an ethoxypropyl group, a 4-ethoxybutyl group, a 2-propyloxyethyl group, a 4-methoxybutyl group, and a 2-ethoxybutyl group.

These terminal ester groups are activated by a carbonyl group at the β-position, and have good curability upon heating by a transesterification reaction with a hydroxyl group of component (c) or component (d) described below. be able to. The above n is 1 or more, and m is 2 or more. That is, from the viewpoint of curability, the component (a) has two or more active methylene groups or active methine groups in one molecule. Note that m
Is the valence of the polyol R ¹ (OH) _m .

Such a component (a) can be obtained, for example, from malonic acid, a malonic ester compound, a malonic acid derivative or an ester compound of a malonic acid derivative, and a polyol. Specifically, there can be mentioned a method of forming a diester compound or a monoester compound of malonic acid or a malonic acid derivative by transesterification with the polyol, and the like.

When the component (a) is obtained by such a method, the above reaction is carried out with the equivalent of malonic acid or malonic acid derivative in excess of the equivalent of the polyol, so that the resulting component (a) has a molecular terminal. An ester group of malonic acid or a malonic acid derivative can be formed.

The component (a) is described in JP-A-9-30.
An acrylic monomer having a structure of malonic acid or a malonic acid derivative in a molecule as disclosed in JP-A-9931 and other acrylic monomers and / or non-acrylic monomers are copolymerized by a conventional method. be able to. The acrylic monomer having a structure of malonic acid or a malonic acid derivative in the molecule can be obtained by a transesterification reaction between hydroxyalkyl (meth) acrylate and malonic acid diester. For example, 2- (methoxymalonyloxy) Ethyl methacrylate and the like can be mentioned. Other acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, and n-butyl (meth) acrylate.
Acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-
Hydroxypropyl (meth) acrylate, adduct of 2-hydroxyethyl (meth) acrylate and caprolactone, acrylamide, methylenebisacrylamide,
Acrylic nitrile and the like can be mentioned, and as the non-acrylic monomer, styrene, α-methylstyrene, itaconic acid, maleic acid, vinyl acetate and the like can be mentioned. By copolymerizing such an acrylic monomer, component (a) obtained from an ester compound of malonic acid or a malonic acid derivative and a polyol can be formed as a result.

In addition, the above-mentioned component (a) can be obtained, for example, by subjecting a monoester compound of malonic acid or a malonic acid derivative to an addition reaction with a polyepoxy group compound. The number average molecular weight of the component (a) contained in the thermosetting coating composition of the present invention is from 300 to 3,000. If the number average molecular weight is less than 300, the hardness and crosslinking density of the resulting coating film will be insufficient, and the solvent resistance, water resistance and weather resistance will decrease. On the other hand, when it exceeds 3,000, the viscosity of the resin increases, and the solid content at the time of applying the coating material decreases. Preferably, it is 500 to 2500.

The active hydrogen equivalent of the component (a) is as follows:
It is preferably from 40 to 1,000. If the active hydrogen equivalent is less than 40, the compatibility with other components may be reduced, and if it is more than 1,000, the crosslink density of the obtained coating film is reduced, and various properties and weather resistance of the coating film are reduced. May drop. More preferably, it is 50 to 500. The active hydrogen equivalent in the present specification means the molecular weight per functional group as methylene group is bifunctional and methine group is monofunctional.

The component (b) contained in the thermosetting coating composition of the present invention has two or more methacrylate groups and / or acrylate groups in one molecule. A compound or resin having two or more methacrylate groups and / or acrylate groups having a double bond between β carbons.

As the component (b), a (meth) acrylate ester compound of a polyol or a resin,
Polyester (meth) acrylate resin, unsaturated polyester resin, epoxy (meth) acrylate resin, urethane (meth) acrylate resin, α, β-unsaturated carbonyl group-containing acrylic resin, polyether (meth) acrylate resin, and (meth) ) At least one selected from the group consisting of acrylate group-containing silicone resins.

The (meth) acrylate ester compound of the polyol is, for example, a methacrylate ester or an acrylate ester of a polyol, and specifically, ethylene glycol di (meth) acrylate,
Neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-
Cyclohexyl dimethanol di (meth) acrylate,
4,4'-isopropylidenedicyclohexanol di (meth) acrylate, bis (hydroxymethyl) tricyclo [5,2,1,0] decane (meth) acrylate, 1,3,5-tris (2-hydroxyethyl) Compounds such as cyanuric acid tri (meth) acrylate can be exemplified.

The (meth) acrylate ester resin of the polyol is obtained, for example, by adding a methacrylate or acrylate having a functional group capable of reacting with a hydroxyl group to a hydroxyl group-containing resin. The hydroxyl group-containing resin is not particularly limited, and examples thereof include an acrylic resin, a polyester resin, a polyether resin, an epoxy resin, a polyurethane resin, and a silicone resin, and a methacrylate or a methacrylate having a functional group capable of reacting with the hydroxyl group. As acrylate,
For example, 2- (meth) acryloyloxyethyl isocyanate and the like can be mentioned.

The polyester (meth) acrylate resin includes, for example, an acid component composed of another polycarboxylic acid such as phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, sebacic acid and trimellitic acid; Can be obtained by adding, for example, glycidyl methacrylate to the carboxylic acid group-containing polyester resin obtained by the polycondensation reaction with the polyol.

Examples of the unsaturated polyester resin include α, β such as maleic anhydride and fumaric acid.
-An unsaturated dicarboxylic acid and an acid component consisting of phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, other polycarboxylic acids such as trimellitic acid,
It can be obtained by a polycondensation reaction with the above-mentioned polyol.

Other examples of the epoxy (meth) acrylate resin include those obtained by ring-opening addition of an epoxy group of an epoxy resin such as bisphenol type or novolak type by reaction with methacrylic acid or acrylic acid; As the urethane (meth) acrylate resin, for example, isophorone diisocyanate,
Polyisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, or urethane prepolymers thereof, and those obtained by addition reaction of 2-hydroxyethyl (meth) acrylate, as the polyether (meth) acrylate resin, for example, What is obtained by reacting 2-methacryloyloxyethyl isocyanate with a polyether having a hydroxyl group at the terminal, and the above-mentioned acrylic resin containing an α, β-unsaturated carbonyl group include, for example, acrylic copolymerized with glycidyl (meth) acrylate Examples include those obtained by reacting a resin with (meth) acrylic acid and those obtained by reacting a carboxy-containing acrylic resin with an epoxy group-containing acrylic monomer such as glycidyl (meth) acrylate. I can do it.

Further, examples of the (meth) acrylate group-containing silicone resin include polyorganosiloxane having a 3-methacryloyloxypropyl group at both ends. In addition, as the component (b), a plurality of hydroxyl groups, epoxy groups, and the like can be used in addition to a methacrylate group and an acrylate group. Such can be easily obtained by combining the above methods.

The number average molecular weight of the component (b) contained in the thermosetting coating composition of the present invention is from 200 to 3,000. When the molecular weight is less than 200, the resin itself volatilizes during heat curing, and the resulting coating film has reduced solvent resistance, water resistance, and weather resistance. Also, if it exceeds 3000,
The viscosity of the resin increases, and the solid content at the time of applying the paint decreases. Preferably, it is 300 to 2500.

The double bond equivalent of the component (b) is as follows:
It is preferably from 100 to 1500. When the double bond equivalent is less than 100, the obtained coating film may be hard and brittle, and an unreacted (meth) acrylate group may remain in the obtained coating film, and the weather resistance may decrease. .
On the other hand, when it exceeds 1500, the degree of crosslinking of the obtained coating film is low, and the durability may be reduced. Preferably,
100 to 1,000. In addition, the double bond equivalent in this specification means the molecular weight per one double bond.

In the thermosetting coating composition of the present invention, the ratio of the equivalent of the active hydrogen of the component (a) / the equivalent of the double bond of the component (b) is preferably from 0.3 to 3.0. It is more preferably 0.5 to 2.0. If the equivalent ratio is outside the above range, the curability may be insufficient. In addition, the equivalent of the active hydrogen is the solid content weight of the component (a) in the coating composition / the active hydrogen equivalent,
The equivalent of the double bond is determined by the solid content weight of the component (b) in the coating composition / the double bond equivalent.

The component (c) contained in the thermosetting coating composition of the present invention has an onium salt and coexists with the component (d) having an epoxy group and / or a 5-membered carbonate group described below. Below, it functions substantially as a reaction catalyst. Specific examples of the cation of the onium salt of the component (c) include a tetrabutylammonium cation, a tetramethylammonium cation, a tetrapropylammonium cation, a tetraoctylammonium cation, a tetradecylammonium cation, a tetrahexylammonium cation, Quaternary ammonium cations such as hexadecyl ammonium cation, triethylhexyl ammonium cation, 2-hydroxyethyl trimethyl ammonium (choline) cation, methyl trioctyl ammonium cation, cetyl trimethyl ammonium cation, 2-chloroethyl trimethyl ammonium cation, methyl pyridinium cation; Quaternary phosphonium cations such as tetrabutylphosphonium cation; Tertiary sulfonium cation such as chill sulfonium cation and the like.

The cation of the onium salt contained in the component (c) contained in the thermosetting coating composition of the present invention is preferably a quaternary ammonium cation that can be industrially obtained from various types.

The anion of the onium salt contained in the component (c) is one which forms a stable salt with the above-mentioned cation. Specifically, fluoride such as chloride anion, bromide anion and iodide anion is used. Excluding halide anions; carboxylate anions such as benzoate, salicylate, maleate and phthalate; sulfonate anions such as methanesulfonate, p-toluenesulfonate and dodecylbenzenesulfonate; sulfate anion; Sulfate anion such as sulfate anion; nitrate anion such as nitrate anion; phosphate anion such as phosphate anion and di-t-butyl anion; The anion of the onium salt of the component (c) contained in the thermosetting coating composition of the present invention is preferably a halide anion or a carboxylate anion from the viewpoint of curability.

The component (d) contained in the thermosetting coating composition of the present invention has an epoxy group and / or a 5-membered carbonate group, and together with the component (c) having an onium salt described above. It functions as a reaction catalyst.

In the thermosetting coating composition of the present invention, the non-aqueous dispersion (c-c) in which the component (c) having an onium salt contains resin particles insoluble in an organic solvent having an onium salt.
1) and / or a non-aqueous dispersion (d-1) in which the component (d) contains resin particles insoluble in an organic solvent having an epoxy group and / or a 5-membered carbonate group. .

Such a non-aqueous dispersion (c-1) is, for example, soluble in a resin solution obtained by dissolving a hydroxyl group-containing resin in an organic solvent, before polymerization in the resin solution. ,
It can be obtained by polymerizing a monomer mixture of an acrylic monomer having an onium salt which is insoluble after polymerization and other monomers by a conventional method.

The hydroxyl group-containing resin is not particularly limited, and may be an acrylic resin obtained by copolymerizing an acrylic monomer having a hydroxyl group and another acrylic monomer and / or a non-acrylic monomer by a conventional method, or a polyvalent resin. Examples thereof include a polyester resin obtained by polycondensation of an acid component such as a carboxylic acid and an alcohol component such as a polyhydric alcohol by a conventional method, and an alkyd resin modified with a fatty acid or an oil component.

Specific examples of the acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate.
-Adducts of hydroxyethyl (meth) acrylate and caprolactone. The other monomer does not contain a hydroxyl group. Specifically, the acrylic monomer having an active methylene group and / or an active methine group in the molecule described in the above-mentioned component (a) and other acrylic monomers Examples of the monomer include those which do not contain a hydroxyl group and non-acrylic monomers. In the hydroxyl-containing resin, the other monomer preferably does not contain an onium salt.

Specific examples of the polyhydric carboxylic acid include adipic acid, phthalic acid, maleic acid, sebacic acid and their acid anhydrides. Specific examples of the polyhydric alcohol include: Examples thereof include those described for the component (b). Furthermore, examples of the fatty acid include oleic acid, linolenic acid, and stearyl acid, and examples of the oil component include castor oil, linseed oil, and coconut oil.

In such a resin, for example, 2- (meth) acryloyloxyethyl isocyanate is partially added to the hydroxyl group of the resin in order to improve the stability of the obtained non-aqueous dispersion (c-1). May contain a (meth) acrylate group, the acrylic resin,
In addition to the polyester resin and the alkyd resin, among the above components (b), those having a hydroxyl group may be used. The organic solvent is not particularly limited and includes, for example, well-known aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, petroleum-based mixed solvents, alcohol-based solvents, ether-based solvents, ketone-based solvents, and ester-based solvents. Things can be mentioned. These may be used alone or in combination of two or more.

The acrylic monomer having an onium salt is preferably one in which the onium salt comprises the above cation and an anion. For example, 2- (methacryloyloxy) ethyltrimethylammonium chloride,
Quaternized aminoalkyl (meth) such as 2- (methacryloyloxy) ethyltrimethylammonium bromide
Acrylates; quaternized aminoalkyl (meth) acrylamides such as methacryloylaminopropyltrimethylammonium chloride and methacryloylaminopropyltrimethylammonium bromide; quaternary ammoniums such as tetrabutylammonium (meth) acrylate and trimethylbenzylammonium (meth) acrylate Meth) acrylates; quaternary phosphinoalkyl (meth) acrylates such as methacryloyloxyethyltrimethylammonium dimethyl phosphate; trioctyl (4-vinylbenzyl) phosphonium chloride, tri-n-butyl (2-methacryloyloxyethyl) phosphonium chloride, 2 -Acid phosphoxyethyl methacrylate ditetrabutylammonium salt,
Quaternary phosphonium (meth) acrylates such as tri-n-butylmethacryloyloxyethylphosphonium chloride and tri-n-octyl-4-vinylbenzylphosphonium chloride can be exemplified. These may be used alone or in combination of two or more.

The above-mentioned other monomer does not contain an onium salt, and specifically, an acrylic resin having an active methylene group and / or an active methine group in the molecule described in the above component (a). Among these monomers, there may be mentioned those which do not contain an onium salt among non-acrylic monomers and other acrylic monomers. The non-aqueous dispersion (c-
1) can have a plurality of active methylene groups, active methine groups, (meth) acrylate groups, hydroxyl groups and the like in the same molecule in addition to the onium salt.

The non-aqueous dispersion (d-1) is, for example, a resin solution obtained by dissolving a hydroxyl group-containing resin in an organic solvent. ,
Epoxy groups and / or 5 which are insoluble after polymerization
It can be obtained by polymerizing a monomer mixture comprising an acrylic monomer having a membered ring carbonate group and another monomer by a conventional method. The hydroxyl group-containing resin and the organic solvent are not particularly limited, and specific examples include those described for the non-aqueous dispersion (c-1). In addition, from the viewpoint of storage stability, in the hydroxyl group-containing resin, the other monomer preferably does not contain an epoxy group and / or a 5-membered carbonate group.

Examples of the acrylic monomer having an epoxy group include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate,
Examples include glycidyl ether of hydroxybutyl (meth) acrylate and (meth) acrylate of 3,4-epoxycyclohexanemethanol. Also, 5
Examples of the acrylic monomer having a membered carbonate group include 4-methacryloyloxymethyl-2-oxo-1,3-dioxolane.
These may be used alone or in combination of two or more.

The other monomer does not contain an epoxy group and / or a five-membered carbonate group. Specifically, an active methylene group and an active methylene group are contained in the molecule described in the above component (a). Among the acrylic monomers having an active methine group and / or other acrylic monomers, those containing no epoxy group and / or 5-membered carbonate group and non-acrylic monomers can be mentioned.

The non-aqueous dispersion (d-1) thus obtained may contain an epoxy group and / or a 5-membered carbonate group, an active methylene group, an active methine group, a (meth) acrylate group, a hydroxyl group and the like. In the same molecule.

The weight ratio between the hydroxyl group-containing resin and the monomer mixture in the non-aqueous dispersion (c-1), and the ratio between the hydroxyl group-containing resin and the monomer in the non-aqueous dispersion (d-1) The weight ratio to the mixed solution is preferably 80/20 to 10/90. When the weight ratio exceeds 80/20, the curability may decrease, and when it is less than 10/90, a stable non-aqueous dispersion may not be obtained.

The average particle size of the resin particles contained in the non-aqueous dispersion (c-1) and the non-aqueous dispersion (d-1) is preferably 0.1 to 1.0 μm. 1 to
More preferably, it is 0.5 μm. When the average particle diameter is less than 0.1 μm, polymerization is difficult and it is difficult to obtain. On the other hand, if it exceeds 1.0 μm, the composition tends to be non-uniform in the coating composition, which may cause sagging during application.

The non-aqueous dispersion (c-1) and the non-aqueous dispersion (d-1) each have a solid content of 40% by weight or more and
The viscosity at 0 ° C. is preferably 10,000 mPa · s or less, and more preferably the solid content is 50% by weight or more and the viscosity at 20 ° C. is 5000 mPa · s or less. The viscosity at a solid content of 40% by weight or more is 10
When it exceeds 000 mPa · s, the content of the organic solvent in the paint at the time of application may be large. Although the lower limit of the viscosity is not particularly limited, it is substantially 50 mPa ·
s.

The total content of the non-aqueous dispersion (c-1) and / or the non-aqueous dispersion (d-1) contained in the thermosetting coating composition of the present invention is the same as that of the component (a). 10% based on the solid content based on the total weight of component (b)
It is preferably about 150% by weight. If the total content is less than 10% by weight, curability and sagging during coating will be insufficient, and if it exceeds 150% by weight,
The viscosity of the paint may increase, and the content of the organic solvent in the paint at the time of application may increase.

As the component (c) contained in the thermosetting coating composition of the present invention, in addition to the non-aqueous dispersion (c-1),
An onium salt compound and a resin having an onium salt can be exemplified. As such, specifically,
Tetrabutylammonium chloride, tetraethylammonium bromide, diethyldibutylammonium chloride, octyltrimethylbromide, dioctyldimethylammonium salicylate, benzyllauryldimethylammonium chloride, 2-hydroxyethyltrimethylammonium chloride, tetraethylphosphonium chloride, tetraethylphosphonium bromide, tetrabutylphosphonium Onium salt-containing compounds such as chloride and trimethylsulfonium chloride can be exemplified. In addition, such an onium salt is substantially neutral, and its aqueous solution shows a neutral pH in a weakly basic to weakly acidic region.

Further, a resin which can be obtained by copolymerizing the acrylic monomer having an onium salt with another monomer by a conventional method may be used.
Specific examples of the acrylic monomer having an onium salt and the other monomer include those described for the non-aqueous dispersion (c-1).

As the component (d) contained in the thermosetting coating composition of the present invention, in addition to the non-aqueous dispersion (d-1),
Examples thereof include compounds and resins having an epoxy group and / or a 5-membered ring carbonate group. Examples of such compounds include phenyl glycidyl ether, bisphenol type epoxy resin, reaction products of epichlorohydrin and polyhydric alcohol, glycidyl compounds such as glycidyl benzoate and glycidyl (meth) acrylate;
Alicyclic epoxy compounds such as (3,4-epoxycyclohexyl) methoxycarbonyl-1,2-epoxycyclohexane and 3,4-epoxycyclohexanemethanol; and α-olefin epoxides such as epoxyhexadecane. Examples of the compound having a 5-membered ring carbonate group include 2-oxodioxolane and derivatives thereof.

Further, the epoxy group and / or 5
It may be a resin that can be obtained by copolymerizing an acrylic monomer having a membered carbonate group with another monomer by a conventional method. Specific examples of the acrylic monomer having an epoxy group and / or a 5-membered ring carbonate group and the other monomers include those described in the non-aqueous dispersion (d-1).

The content of the component (c) in the thermosetting coating composition of the present invention is defined as an onium salt equivalent relative to the total equivalent of active hydrogen equivalent and double bond equivalent contained in the coating composition. It is preferably 0.1 to 10%, and 0.1 to 10%.
More preferably, it is 2 to 5%. When the content is less than 0.1%, the curability may decrease. When the content is more than 10%, it may be difficult to uniformly contain the composition in the coating composition or the performance of the obtained coating film may be poor. May drop.

The content of the component (d) in the thermosetting coating composition of the present invention is defined as an equivalent of an epoxy group and a five-membered ring carbonate group and an equivalent of active hydrogen contained in the coating and a double bond. 0.2 with respect to the total equivalent of
It is preferably from 50 to 50%, more preferably from 1 to 30%. If the content is less than 0.2%, the curability may decrease, and if it exceeds 50%, the performance of the resulting coating film may decrease.

The thermosetting coating composition of the present invention further comprises
A curing agent such as an isocyanate compound or a melamine resin can be included for the purpose of improving curability, improving compatibility, adjusting coating film performance, and the like. Examples of the isocyanate compound include monomers such as hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl) isocyanate, norbornene diisocyanate, and the like, nurate, buret, alphanate, adduct, and uretdione. And the like. Further, a blocked isocyanate compound obtained by blocking these functional groups may be used. Examples of the melamine resin include methylated melamine, butylated melamine, melamine mixed with methylbutyl, benzoguanamine, and urea formalin resin. In addition, tris (alkoxycarbonylamino) triazine such as Cylink 2000 (manufactured by Mitsui Cytec) may be used. When the thermosetting coating composition of the present invention contains the above-mentioned curing agent, the content thereof is, for example, 1 to 1 of the total weight of the solid contents of the above components (a), (b), (c) and (d). Preferably it is 40% by weight.

The thermosetting coating composition of the present invention may contain a curing accelerator such as an organotin compound, an organozinc compound, an organoaluminum compound or an organotitanium compound for further improving the curability. In that case, the content is, for example, 0.01 to the resin solid content of the coating composition.
It is preferably about 5% by weight.

The thermosetting coating composition of the present invention can contain a coloring component in addition to the above components. As the coloring components, e.g., iron oxide, lead oxide, titanium dioxide, carbon black, coal dust, talc, barium sulfate, cadmium yellow, cadmium red, such as chrome yellow inorganic pigment; phthalocyanine blue, phthalocyanine green, carbazole violet, Anthrapyridine, azo orange, flavanthrone yellow, isoindoline yellow, azo yellow, indathrone blue,
Organic pigments such as dibromanzathrone red, perylene red, azo red, anthraquinone red, and quinacridone red; dyes such as 1: 2 chromium complex black, 1: 2 chromium complex yellow, and 1: 2 cobalt complex yellow; aluminum powder and alumina powder And glittering materials such as bronze powder, copper powder, tin powder, zinc powder, iron phosphide, metal-coated mica powder, titanium dioxide-coated mica powder, and titanium dioxide-coated glass powder. These may be used alone or in combination of two or more.

The thermosetting coating composition of the present invention may further contain, if necessary, additives known to those skilled in the art.
An organic solvent or the like can be included. Mentioned above is not particularly restricted but includes additives, anti-sagging agents, ultraviolet absorbers, light stabilizers,
Examples include antioxidants, surface conditioners, defoamers, pigment dispersants, antistatic agents, and the like.

The anti-sagging agent is not particularly limited.
For example, crosslinkable organic fine particles and silica fine particles can be used. The crosslinkable organic fine particles are, for example, using an emulsifier, emulsion-polymerizing a monomer mixture containing a polyfunctional acrylic monomer to obtain an emulsion, and then evaporating water or replacing water with an organic solvent. It can be obtained by a method well-known by those skilled in the art, such as a method of obtaining the same. The silica fine particles are not particularly limited, and examples thereof include commercially available ones such as colloidal silica and ultrafine anhydrous silica.

When the thermosetting coating material of the present invention contains the above-mentioned anti-sagging agent, the solid content of the coating is determined by the above-mentioned component (a),
It is preferably 0.1 to 10% by weight based on the total weight of the solid contents of (b), (c) and (d). If the content is less than 0.1% by weight, the sagging property at the time of application may be insufficient. If the content is more than 10% by weight, the viscosity of the coating material increases, and There is a possibility that the content of the organic solvent becomes large and the obtained coating film becomes cloudy. Such thermosetting coating composition,
The above components can be obtained by mixing and stirring using a method well-known by those skilled in the art such as a disperser or a mill.

The thermosetting coating composition of the present invention has a solid content of 50% by weight or more at a viscosity of 100 mPa · s at 20 ° C. When the obtained coating composition is out of the above-mentioned predetermined viscosity, it can be adjusted by further adding an organic solvent or distilling off the organic solvent contained in the coating under reduced pressure. The above viscosity is a standard viscosity at the time of applying a paint, and at an actual application site, the paint is controlled by this viscosity. The viscosity can be measured by a single cylindrical rotary viscometer, for example, a measuring instrument called a B-type viscometer such as Model BM manufactured by Tokyo Keiki Co., Ltd. The solid content is 5
When the content is less than 0% by weight, the content of the organic solvent in the coating material becomes large, and various problems such as environmental pollution occur. It is more preferably at least 60% by weight. The viscosity at 20 ° C. is 1
00mPa · s is a Ford Cup NO. 4 (20 ° C.)
About 30 seconds.

The method for forming a coating film of the present invention is characterized in that in the coating film forming method for applying the above-mentioned thermosetting coating composition to an object to be coated, Is 50% by weight or more. The object to be coated includes iron, steel, aluminum,
Metal materials such as tin, zinc, and alloys and castings containing these metals, and plastic materials can be exemplified, and automobile bodies and parts such as passenger cars, trucks, motorcycles, and buses are preferable. These may be surface-treated in advance, or may be coated with an undercoat to form an undercoat. It can also have intermediate coating is formed intermediate coating film coated on the undercoating film may be further base paint is applied to form the base coating film.
Such base coats, intermediate coats and base coats are well known by those skilled in the art.

The thermosetting coating composition at the time of the application is as follows:
If necessary, the viscosity can be adjusted with an organic solvent. The organic solvent is not particularly limited, and examples thereof include organic solvents well known by those skilled in the art. The viscosity of the coating composition to be applied is not particularly limited, and can be appropriately set according to a coating method described later. The coating method is not particularly limited, and examples thereof include brush coating, roller coating, air spray coating, airless spray coating, and dip coating. Particularly when the object to be coated is an automobile body or a part or the like. It is preferable to use an air electrostatic spray coating method or a rotary atomization type electrostatic coating method, and the viscosity of the coating when applied by such a method is usually 100 mP at 20 ° C.
a.s, Ford Cup NO. 4 (20 ° C.) and a viscosity of about 30 seconds. From the viewpoint of reducing the amount of the organic solvent volatilized at the time of application and heating, the coating solid content of the thermosetting coating composition at the time of application is 50% by weight or more, preferably 60% by weight or more. The coating film thickness is not particularly limited, and can be appropriately set according to the use of the obtained coated product.

The temperature for curing by heating is as follows.
80 to 200 ° C., preferably 120 to 180 ° C.
It is more preferable that the temperature is ° C. When the temperature is lower than 80 ° C, the curability of the obtained coating film may be insufficient, and when it exceeds 200 ° C, the obtained coating film may be hard and brittle. In addition, the heating time is not particularly limited, and can be appropriately set according to the heating temperature.

[0077]Multilayer coating method  The method for forming a multilayer coating film of the present invention comprises an electrodeposition coating film and an intermediate coating film.
Apply the base paint on the object on which the film has been formed.
Step (1) of forming a cured base coating film, the above steps
Clear paint on the uncured base coating film obtained in (1)
Process of applying an uncured clear coating film
(2), uncured obtained in the above steps (1) and (2)
Heat and cure the base and clear coatings simultaneously
For forming a multilayer coating film including a step (3) of obtaining a coating film by heating
Wherein the clear paint is the thermosetting paint set
It is a product and the paint solid content is 50% by weight or more.
It is a feature.

In the first step of the method for forming a multilayer coating film of the present invention, a base coating material is applied to a substrate on which an electrodeposition coating film and an intermediate coating film have been formed to form an uncured base coating film. To form.

The electrodeposition coating material for forming the electrodeposition coating film is not particularly limited, and may be either a cationic type or an anionic type. From the viewpoint of corrosion resistance and rust prevention,
It is preferably of the cationic type. Further, the intermediate coating for forming the intermediate coating film is not particularly limited, and a thermosetting coating film containing a resin having a curable functional group such as a carboxyl group, a hydroxyl group, an epoxy group, and an isocyanate group and a curing agent is formed. And those containing a coloring component and an extender. Specific examples of the coloring pigment, extender pigment and dye include those described above for the coating composition. In general, such an intermediate coating composition is preferably of a solution type such as an organic solvent type, an aqueous type (water-soluble, water-dispersible, emulsion) and a non-aqueous type.

The object to be coated and the coating method are not particularly limited, and those described in the above-mentioned coating film forming method can be used. The base paint is not particularly limited, and specifically, for example, a thermosetting coating film-forming component including a resin having a curable functional group such as a carboxyl group, a hydroxyl group, an epoxy group, and an isocyanate group and a curing agent; And those containing a coloring pigment or an extender. As the coloring pigment, extender and dye,
Specifically, those described in the above-mentioned coating composition can be exemplified.

As the above-mentioned coating method, specifically, those described in the above-mentioned coating film forming method can be mentioned. When the base paint is applied to an automobile body and parts, etc., in order to enhance the design, it is applied by multi-stage application by the air electrostatic spray coating, preferably in two stages, or by the air static spraying. It is preferable to perform the coating by a combination of the electrospray coating and the above-mentioned rotary atomization type electrostatic coating.

The above-mentioned base paint is usually applied so as to have a dry film thickness of 5 to 35 μm. When the dry film thickness is less than 5 μm, the concealment of the base may be insufficient or color unevenness may occur. When the dry film thickness is more than 35 μm, sagging at the time of application or burning at the time of heat curing may occur. Might be. Thus, an uncured base coating film can be formed.

The term “uncured base coating” is a concept including the state after the preheating treatment. As the above preheating treatment, for example, one hour at room temperature to about 100 ° C
Heat treatment for 10 minutes.

In the second step in the method for forming a multilayer coating film of the present invention, a clear paint is applied on the uncured base coating film obtained in the above step (1) to form an uncured clear coating film. Wherein the clear coating is the coating composition described above. Such a clear paint may contain a color pigment, an extender and a dye to such an extent that the transparency of the obtained coating film is not lost. Such a method is called a wet-on-wet method.

The viscosity of the clear paint to be applied can be adjusted with an organic solvent as needed for application. The method for applying the above is not particularly limited,
Those described in the above-mentioned coating film forming method can be exemplified. The organic solvent is not particularly limited, and specific examples thereof include the organic solvents described for the thermosetting coating composition. In addition, the viscosity of the clear paint to be applied is not particularly limited, and can be appropriately set according to a coating method described later. Here, from the viewpoint of reducing the amount of the organic solvent volatilized during coating and heating,
The solid content of the clear paint to be applied is preferably 50% by weight or more, and more preferably 60% by weight or more.

The above clear paint is usually applied so as to have a dry film thickness of 10 to 80 μm. When the dry film thickness is less than 10 μm, the appearance of the obtained coating film may be deteriorated. When the dry film thickness is more than 80 μm, there is a possibility that sagging may occur during application or a crack may occur during heat curing. More preferably, it is 15 to 60 μm. Thus, an uncured clear coating film can be obtained on the uncured base coating film.

In the third step in the method for forming a multilayer coating film of the present invention, the uncured base coating film and the clear coating film obtained in the above steps (1) and (2) are simultaneously heated and cured to form a coating film. What you get.

The heating and curing temperature is 80 to
Preferably it is 200 ° C., more preferably 120 ° C.
１８０180 ° C. When the temperature is less than 80 ° C,
If the curability is insufficient and the temperature exceeds 200 ° C,
The resulting coating may be hard and brittle. The time for heat curing can be appropriately set according to the above temperature, but when the temperature is 80 to 200 ° C., for example, 10 to 10
60 minutes.

As described above, the thickness of the multilayer coating film obtained by the above steps (1), (2) and (3) is usually 3
0 to 300 μm, preferably 50 to 250 μm
m is more preferable. When the film thickness is less than 30 μm, the film strength of the obtained multilayer coating film may be reduced. When the film thickness is more than 300 μm, the film physical properties may be reduced or the coating film performance may be deteriorated.

[0090]

EXAMPLES The present invention will be described in detail with reference to specific examples, but the present invention is not limited to the following examples. In the following, “parts” means “parts by weight”.

[0091]Production Example 1 Preparation of Component (a1) Solution  Condenser, stir bar, thermometer, dropping funnel, nitrogen introduction
In a flask equipped with a tube, 57 parts of xylene was added, and
° C and maintained.
B) 45 parts of ethyl methacrylate, methyl methacrylate
10 parts, cyclohexyl methacrylate 15 parts, styrene
20 parts of len, 10 parts of α-methylstyrene dimer and
Kayaester O (t-butylperoxy manufactured by Kayaku Akzo)
Octate, polymerization initiator) for 3 hours
After the addition, the mixture was aged for 0.5 hour. In addition, Kaya
0.5 hours of a mixture of 1 part of ester O and 10 parts of xylene
The mixture was added dropwise over a period of time and aged for 1.5 hours. afterwards,
Under reduced pressure, 13 parts of the solvent was distilled off to obtain a component (a1) solution.
Was. The solid content of the obtained component (a1) solution was 65.0% by weight.
%, Gel permeation chromatography (GPC)
The measured number average molecular weight is 1970 and the active hydrogen equivalent is 25.
It was 5.

[0092]Production Example 2 Preparation of Component (a2) Solution  In a device similar to that of Production Example 1, 72 parts of xylene was put and 135 parts of xylene were added.
C. After the temperature was raised to and kept at a
After dripping over 3 hours, the mixture was aged for 0.5 hour. Further
Mixed with 0.8 parts of Kayaester O and 10 parts of xylene
The solution was added dropwise over 0.5 hours, and further aged for 1.5 hours
did. Thereafter, 28 parts of the solvent was distilled off under reduced pressure, and the component (a)
2) was obtained. The solid content of the obtained component (a2) solution, GP
The number average molecular weight and active hydrogen equivalent by C measurement are shown in Table 1.
did.

[0093]Production Example 3 Preparation of Component (a3) Solution  Except that the mixture based on the composition in Table 1 was dropped,
A component (a3) solution was obtained in the same manner as in Preparation Example 1. Obtained
Component (a3) solution solid content, number average by GPC measurement
The molecular weight and active hydrogen equivalent are shown in Table 1.

[0094]Production Example 4 Preparation of Component (a4) Solution  Condenser, solvent recovery device, stirring rod, thermometer, nitrogen inlet
In a flask equipped with an inlet tube, add 1,4-cyclohexanedim
41.9 parts of tanol, 191.9 parts of dimethyl malonate
And heat it up to 120-130 ° C to completely dissolve
Was. While distilling off the generated methanol, gradually remove
Heated to ~ 180 ° C. The obtained methanol is 18.
6 parts. After the methanol has been distilled off,
The unreacted dimethyl malonate was recovered by distillation. Times
The recovered dimethyl malonate was 115.1 parts.
Furthermore, after cooling to about 50 ° C., propylene glycol
Add 17.6 parts of monomethyl ether acetate
A component (a4) solution was obtained. Of the resulting component (a4) solution
The solid content is 85.3% by weight, and the number average molecular weight by GPC is
530 and the active hydrogen equivalent were 86.

[0095]Production Example 5 Preparation of Component (a5) Solution  Same as Production Example 4 except that it was based on the formulation in Table 2.
Thus, a component (a5) solution was obtained. The resulting component (a5)
Liquid solid content, number average molecular weight by GPC measurement, active hydrogen
The equivalents are shown in Table 2.

[0096]Production Example 6 Preparation of Component (a6) Solution  The monomers shown in Table 2 were placed in the same apparatus as in Production Example 4, and 1
The temperature was raised to 20 to 130 ° C. and completely dissolved. Generate
While distilling off methanol, gradually heat to 200 ° C.
Was. The obtained methanol was 23.0 parts. Methano
After the distillation of the solvent has been completed, cool to about 50 ° C
Pyrene glycol monomethyl ether acetate 42.
Nine parts were added to obtain a component (a5) solution. Ingredients obtained
(A5) The solid content of the solution was 70.9% by weight, as determined by GPC.
The number average molecular weight is 1580 and the active hydrogen equivalent is 127.
Was.

[0097]Production Example 7 Preparation of Component (b1) Solution  65 parts of xylene was placed in the same device as in Production Example 1, and
After the temperature was raised to and maintained at 55 ° C., n-butyl methacrylate 55
Parts, styrene 10 parts, glycidyl methacrylate 25
Parts, α-methylstyrene dimer 10 parts and Kayaeste
After dropping a mixed solution consisting of 8 parts of O2 over 3 hours,
Aged for 0.5 hour. Furthermore, Kayaester O1 part and key
A mixture with 10 parts of silene was added dropwise over 0.5 hour.
Thereafter, the mixture was aged for 1.5 hours. Then, 13 parts of solvent under reduced pressure
Was distilled off to obtain an acrylic resin solution. Acrylic tree obtained
Fat solid content is 64.7%, number average molecule by GPC measurement
The amount was 2230.

Further, 12 parts of acrylic acid and 0.05 part of hydroquinone were added to 155 parts of the acrylic resin, and reacted at 120 ° C. until the acid value became 1 or less, to obtain a component (b1) solution. The resulting component (b1) solution had a solid content of 67.1% by weight and a double bond equivalent of 672.

[0099]Production Example 8 Preparation of Component (b2) Solution  In a device similar to that of Production Example 4, 1,6-hexanediol 4
3.4 parts, dimethyl phthalate 14.3 parts, maleic acid di
42.3 parts of methyl and 0.1 weight of dibutyltin oxide
After heating to 120 ° C, methanol
While distilling off, the temperature was gradually raised to 200 ° C. That
After that, keep the temperature at 200 ° C until methanol evaporates.
After continuing heating, cool and cool 39.3 parts of xylene
In addition, a component (b2) solution was obtained. Component (b2) obtained
The solid content of the solution was 65.2% by weight.
The average molecular weight was 1700 and the double bond equivalent was 264.

[0100]Production Example 9 Component (c-1-1) Nonaqueous Dispersion
Preparation of  30 parts of n-butyl acetate was placed in the same apparatus as in Production Example 1,
After the temperature was raised to 110 ° C. and maintained, 2-ethylhexyl meta
25 parts of acrylate, 7 parts of styrene, 2-hydroxyethyl
Acrylate 18 parts and Kayaester O3 parts
Over 3 hours, and then aged for 1 hour
Was. Further, 0.3 part of Kayaester O and n-butyl acetate
2 hours after dropping the mixture with 3 parts over 0.5 hours
After aging, a hydroxyl group-containing resin was obtained. For GPC measurement of this resin
Its number average molecular weight was 7,300.

To this resin solution was further added n-butyl acetate.
After adding 4 parts, 5 parts of 2- (methacryloyloxy) ethyltrimethylammonium chloride, 25 parts of methyl methacrylate, 2-hydroxyethyl acrylate 2
A monomer mixture comprising 0 parts and 0.8 part of Kayaester O was added dropwise over 3 hours, and the mixture was aged for 1 hour. afterwards,
0.08 parts of Kayaester O was added, and the mixture was aged for 1 hour to obtain a milky white component (c-1-1) non-aqueous dispersion. The solid content of the obtained dispersion was 60.4% by weight, and the viscosity measured by a B-type viscometer (model BM manufactured by Tokyo Keiki Co., Ltd.) was 1200 mPa · s at 20 ° C.

[0102]Production Example 10 Component (c-1-2) Non-aqueous dispersion
Preparation of liquid  27 parts of n-butyl acetate was placed in the same apparatus as in Production Example 1,
After the temperature was raised to 110 ° C. and maintained, 2-ethylhexyl meta
20 parts of acrylate, 10 parts of styrene, 2-hydroxy
From 10 parts of chill acrylate and 3 parts of Kayaester O3
The mixture was dropped over 3 hours, and then aged for 1 hour.
Was. Further, 0.3 part of Kayaester O and n-butyl acetate
2 hours after dropping the mixture with 3 parts over 0.5 hours
After aging, a hydroxyl group-containing resin solution was obtained. GPC measurement of this resin
The number average molecular weight was determined to be 5,500.

To this resin solution was further added n-butyl acetate
After adding 0 parts, a monomer mixture solution consisting of 8 parts of 2- (methacryloyloxy) ethyltrimethylammonium bromide, 27 parts of methyl methacrylate, 25 parts of 2-hydroxyethyl methacrylate and 0.8 part of Kayaester O is added dropwise over 3 hours. After that, it was aged for 1 hour. Thereafter, after adding 0.08 parts of Kayaester O, the mixture was aged for 1 hour to obtain a milky white component (c-1-2) non-aqueous dispersion. The solid content of the obtained dispersion was 60.2% by weight, and the viscosity measured by a B-type viscometer (model BM manufactured by Tokyo Keiki Co., Ltd.) was 1200 mPa · s at 20 ° C.

[0104]Production Example 11 Non-aqueous dispersion of component (d-1-1)
Preparation of liquid  In the same apparatus as in Production Example 1, 47 parts of n-butyl acetate was added,
After the temperature was raised to 110 ° C. and maintained, 2-ethylhexyl meta
Acrylate 25 parts, styrene 10 parts, 2-hydroxyd
From 15 parts of chill acrylate and 3 parts of Kayaester O3
Over 3 hours, and then aged for 1 hour
Was. Further, 0.3 part of Kayaester O and n-butyl acetate
2 hours after dropping the mixture with 3 parts over 0.5 hours
After aging, a hydroxyl group-containing resin solution was obtained. GPC measurement of this resin
The number average molecular weight determined was 7000.

To this resin solution was further added n-octane 20
After the addition, a monomer mixture comprising 15 parts of glycidyl methacrylate, 20 parts of methyl methacrylate, 15 parts of 2-hydroxyethyl methacrylate and 0.8 part of Kayaester O was added dropwise over 3 hours, followed by aging for 1 hour. Further, after adding 0.08 parts of Kayaester O, the mixture was aged for 1 hour to obtain a milky white component (d-1-1) non-aqueous dispersion. The solid content of the obtained dispersion was 61.0% by weight, and the viscosity measured by a B-type viscometer (model BM manufactured by Tokyo Keiki Co., Ltd.) was 830 mPa · s at 20 ° C.

[0106]Production Example 12 Component (d-1-2) Non-aqueous Dispersion
Preparation of liquid  20 parts of n-butyl acetate was placed in the same device as in Production Example 1,
After the temperature was raised to 110 ° C. and maintained, 2-ethylhexyl meta
20 parts of acrylate, 2-hydroxyethyl acrylate
A mixture consisting of 10 parts and Kayaester O3 parts is added at 3:00
The mixture was dropped over a period of time, and then aged for 1 hour. In addition, Kaya
A mixture of 0.3 part of ester O and 3 parts of n-butyl acetate
After dripping for 0.5 hours, aged for 2 hours and contains hydroxyl group
A resin solution was obtained. Number average of this resin by GPC measurement
The child size was 4,800.

To this resin solution was further added n-butyl acetate.
After adding 7 parts and 20 parts of n-octane, 30 parts of glycidyl methacrylate, 25 parts of methyl methacrylate,
A monomer mixture comprising 15 parts of 2-hydroxyethyl methacrylate and 0.8 parts of Kayaester O was added dropwise over 3 hours, and then aged for 1 hour. Further, after adding 0.08 parts of Kayaester O, the mixture was aged for 1 hour to obtain a milky white component (d-1-2) non-aqueous dispersion. The solid content of the obtained dispersion was 60.4% by weight, and the viscosity measured by a B-type viscometer (model BM manufactured by Tokyo Keiki Co., Ltd.) was 330 mPa · s at 20 ° C.

[0108]Production Example 13 Preparation of Component (a7) Solution  56 parts of n-butyl acetate was placed in the same apparatus as in Production Example 1, and
After the temperature was raised to 110 ° C. and maintained, 2-acetoacetoxy
20 parts of tyl methacrylate, 2-ethylhexyl methac
15 parts of acrylate, 45 parts of n-butyl methacrylate,
Mixed liquid consisting of 20 parts of styrene and 6 parts of Kayaester O
Was added dropwise over 3 hours and then maintained for 1 hour. further,
A mixture of 0.6 part of Kayaester O and 10 parts of n-butyl acetate
The mixture was added dropwise over 0.5 hour, and aged for 2 hours.
A minute (a7) solution was obtained. Of the obtained component (a7) solution
61.2% by weight, number average molecular weight measured by GPC
Was 8800 and the active hydrogen equivalent was 535.

[0109]Production Example 14 Preparation of Component (a8) Solution  In the same apparatus as in Production Example 4, 4,4'-isopropylidene
81 parts of dicyclohexanol and dimethyl malonate 4
Add 0.5 part, heat up to 120-130 ° C and completely dissolve
Let it go. While distilling off the generated methanol, gradually
Heated to 150-200 ° C. The resulting methanol is
21.6 parts. After the methanol has been distilled off,
Cool to approx. 50 ° C and propylene glycol monomethyl
Add 43 parts of ether ether and dissolve component (a8)
A liquid was obtained. The solid content of the obtained component (a8) solution was 70.
6% by weight, number average molecular weight measured by GPC was 1660
And active hydrogen equivalent was 163.

[0110]Production Example 15 Component (c-2) of Non-aqueous Dispersion
Preparation  30 parts of n-butyl acetate was placed in the same device as in Production Example 1,
After raising the temperature to 110 ° C and holding it, lauryl methacrylate
18 parts, 20 parts of 2-ethylhexyl methacrylate,
7 parts of styrene, 5 parts of acrylic acid and 3 parts of Kayaester O3
Is added dropwise over 3 hours, and then ripened for 1 hour.
Done. Further, 0.3 part of Kayaester O and n-butyl acetate
After dropping the mixture with 3 parts of chill over 0.5 hours,
After aging for a time, a resin solution having no hydroxyl group was obtained. This resin
Has a number average molecular weight of 6,800 by GPC measurement.

To this resin solution was further added n-butyl acetate.
After adding 4 parts, a monomer mixture solution composed of 5 parts of 2- (methacryloyloxy) ethyltrimethylammonium chloride, 25 parts of methyl methacrylate, 20 parts of 2-hydroxyethyl methacrylate and 0.8 part of Kayaester O is added dropwise over 3 hours. After that, it was aged for 1 hour. Thereafter, 0.08 parts of Kayaester O was added, and the mixture was aged for 1 hour to obtain a milky white component (c-2) non-aqueous dispersion. The solid content of the obtained dispersion was 61.7% by weight, and the viscosity at 20 ° C. was 4,200 mPa · s.

[0112]Production Example 16 Component (d-2) of Non-aqueous Dispersion
Preparation  30 parts of n-butyl acetate was placed in the same device as in Production Example 1,
After raising the temperature to 110 ° C and holding it, lauryl methacrylate
18 parts, 20 parts of 2-ethylhexyl methacrylate,
7 parts of styrene, 5 parts of acrylic acid and 3 parts of Kayaester O3
Is added dropwise over 3 hours, and then ripened for 1 hour.
Done. Further, 0.3 part of Kayaester O and n-butyl acetate
After dropping the mixture with 3 parts of chill over 0.5 hours,
After aging for a time, a resin solution having no hydroxyl group was obtained. This resin
Has a number average molecular weight of 6,800 by GPC measurement.

To this resin solution was further added n-butyl acetate.
After adding 7 parts and 20 parts of n-octane, 15 parts of glycidyl methacrylate, 20 parts of methyl methacrylate,
A monomer mixture comprising 15 parts of hydroxyethyl methacrylate and 0.8 part of Kayaester O was added dropwise over 3 hours, and the mixture was aged for 1 hour. Then, Kayaester O.O.
Of the milky white component (d-
2) A non-aqueous dispersion was obtained. The solid content of the obtained dispersion is 6
0.5% by weight, viscosity at 20 ° C. is 5600 mPa ·
s.

[0114]Production Example 17 Production of aqueous acrylic resin  In the same apparatus as in Production Example 1, dipropylene glycol methyl
23.9 parts of propylene glycol methyl ether
16.1 parts of ether were added and mixed and stirred in a nitrogen stream.
Then, the temperature was raised to 120 ° C. Then, ethyl acrylate
54.5 parts, methyl methacrylate 12.5 parts, acrylic
2-hydroxyethyl acid 14.7 parts, styrene 10.0
Part, a mixed solution of 8.5 parts of methacrylic acid, and dipropylene
Glycol methyl ether 10.0 parts, Kayaester O
2.0 parts of initiator solution in parallel over 3 hours
To the reaction vessel. After dropping, 0.5 hours at the same temperature
Aging was performed at different degrees. In addition, dipropylene glycol
5.0 parts of chill ether and 0.3 parts of Kayaester O
Was added dropwise to the reaction vessel over 0.5 hour.
Was. After completion of dropping, aging was performed at the same temperature for 1 hour. Next
Then, under reduced pressure (70 Torr) 110
After distilling off 16.1 parts of the solvent at ℃, dimethylethanol
Add amine and deionized water, and measure by GPC.
Number average molecular weight 10,000, nonvolatile content 31%, solid content acid value
An aqueous acrylic resin having 56 and a hydroxyl value of 70 was obtained.

[0115]Production Example 18 Production of pigment paste  The aqueous acrylic resin obtained in Production Example 17 was replaced with 10
0.0 parts, 28.9 parts of ion-exchanged water, dimethylamino
0.3 parts of Tanol, Degussa Carbon FW-285 (Deg
5.1 parts of carbon black manufactured by Sa AG were preliminarily mixed.
Later, remove the glass bead medium in the paint conditioner.
In addition, mixed and dispersed at room temperature for 1 hour,
A paste was obtained.

[0116]Production Example 19 Production of aqueous base paint  118.8 parts of the aqueous acrylic resin obtained in Production Example 17,
134.3 parts of the pigment paste obtained in Production Example 18,
Mel 204 (Melamine resin manufactured by Mitsui Cytec, solid content
80% by weight) 29.1 parts, ion-exchanged water 161.3 parts
By mixing and stirring, an aqueous base paint was obtained.

[0117]Example 1  Tinuvin 384 (UV absorber manufactured by Ciba Geigy) 2
Parts, 4 parts of SANOL LS-292 (a light stabilizer manufactured by Sankyo) and 4 parts
And an acrylic surface conditioner manufactured by Nippon Paint Co. (solid content 5
(0% by weight) were mixed to obtain an additive solution. Manufacturing example
154 parts of the component (a1) solution obtained in 1, pentaerythr
Litol triacrylate 24 parts, obtained in Production Example 9
34 parts of component (c-1-1) non-aqueous dispersion and Production Example 11
75 parts of the component (d-1-1) non-aqueous dispersion obtained in
After stirring and mixing with a spar to make it uniform,
Add the added additive solution and stir to obtain the thermosetting coating composition.
Obtained. The resulting coating composition was treated with n-butyl acetate.
Measured with a B-type viscometer (model BM manufactured by Tokyo Keiki Co., Ltd.)
So that the viscosity at 20 ° C. becomes 100 mPa · s
Diluted. 1 g of the diluted coating composition was weighed, and 1
After drying at 10 ° C for 1 hour, the solid content of the paint was measured.
And 58% by weight.

The viscosity of the diluted coating composition was set to NO.
It was 30 seconds when measured with a 4 Ford cup (20 ° C.). On a tin plate, the diluted coating composition was applied by air spraying so as to have a dry film thickness of 40 μm.
Test plate 1 was obtained by heating at 40 ° C. for 30 minutes. In addition, after similarly obtaining a coating film on the polypropylene plate, only the coating film was peeled off from the polypropylene plate to prepare a free film.

Further, a power top U-50 (a cationic electrodeposition paint manufactured by Nippon Paint Co., Ltd.) was electrodeposited on a 0.8 mm dull steel plate treated with zinc phosphate so as to have a dry film thickness of 25 μm. The coating was cured by heating for about 1 minute. On top of that, Olga P-2 (a polyester-based solvent-type intermediate coating material manufactured by Nippon Paint Co., Ltd.) was applied by air spraying so as to have a dry film thickness of 40 μm, and was heated and cured at 140 ° C. for 30 minutes to obtain an intermediate coating film. . Further, the aqueous base paint obtained in Production Example 19 was applied thereon by air spraying so as to have a dry film thickness of 16 μm, heated at 80 ° C. for 3 minutes, and then the diluted paint composition was dried. After air spray coating to a thickness of 40 μm, the test plate 2 was obtained by heating at 140 ° C. for 30 minutes.

[0120]Examples 2 to 18 and Comparative Examples 1 to 5  After mixing the components according to Tables 3 to 5, the mixture obtained in Example 1 was obtained.
To obtain a thermosetting coating composition by adding the added additive solution
Other than that, in the same manner as in Example 1, test plates 1, 2 and
Lee film was obtained. The measured paint composition after dilution
The paint solids of the products are shown in Tables 3-5.

[0121]Example 19  117 parts of the component (a5) solution obtained in Production Example 5,
Erythritol triacrylate 56 parts, obtained in Production Example 9
78 parts of the obtained component (c-1-1) non-aqueous dispersion, Production Example 1
89 parts of the component (d-1-2) non-aqueous dispersion obtained in
And Tronate HDT-LV2 (Polyiso manufactured by Rhodia)
10 parts of cyanate, solid content 100% by weight)
After stirring and mixing at, the additive solution obtained in Example 1
Was added and stirred and mixed to obtain a thermosetting coating composition.
Other than the above, in the same manner as in Example 1, test plates 1 and 2 and
-A film was obtained. The measured paint composition after dilution
The paint solids of the products are shown in Table 5.

[0122]Example 20  Tolonate HDT-LV2 Cymer instead of 10 parts
254 (melamine resin manufactured by Mitsui Cytec, solid content 80
(% By weight) except that it was 12 parts.
Thus, test plates 1 and 2 and a free film were obtained. In addition,
The measured paint solid content of the diluted paint composition is shown in Table 5.
did.

[0123]Example 21  Tolonate HDT-LV2 is replaced with Sumiju instead of 10 parts
BL3175 (Block made by Sumitomo Bayer Urethane Co., Ltd.)
Polyisocyanate, solid content 75% by weight) 15 parts
Except that, in the same manner as in Example 19, test plates 1, 2 and
And a free film. Note that the measured coating after dilution is
The paint solids content of the paint compositions are shown in Table 5.

[0124]Example 22  Tolonate HDT-LV2 is replaced with Sumiju instead of 10 parts
Example 19 except that 30 parts of
In the same manner as described above, test plates 1 and 2 and a free film were obtained.
Was. The measured solid content of the paint composition after dilution was measured.
Is shown in Table 5.

[0125]Example 23  Furthermore, PZS-1002 (a crosslinkable organic compound manufactured by Nippon Paint Co., Ltd.)
Fine particles, average particle size 60 nm, solid content 20% by weight) 10 parts
Test plate in the same manner as in Example 21 except that
1, 2 and free films were obtained. In addition, it was measured
The coating solid content of the diluted coating composition is shown in Table 5.

[0126]Evaluation test  The obtained diluted coating composition and test plates 1, 2 and
The following evaluation test was performed on the free film. Evaluation
The results are shown in Tables 3 to 5.

<Curability> (1) Pencil Hardness The obtained test plate 1 was subjected to JIS K 5400.
The pencil hardness was measured according to 8.4.2. HB or higher was regarded as a pass. (2) Crosslinking density The obtained free film was subjected to Vibron DDV-II-E
The crosslink density was measured by type A (dynamic viscoelasticity meter manufactured by Toyo Baldwin Co., Ltd., test conditions: frequency 11 Hz, temperature rise 2 ° C./min). 1.0 × 10 ⁻³ mol / cc or more was judged to be acceptable.

<Appearance> The appearance of the coating film of the obtained test plate 2 was visually evaluated. The evaluation criteria were as follows. ：: uniform gloss △: slightly uneven gloss ×: uneven gloss or no gloss

[0129]

[Table 1]

[0130]

[Table 2]

[0131]

[Table 3]

[0132]

[Table 4]

[0133]

[Table 5]

As is clear from the results shown in Tables 3 to 5, the thermosetting coating composition of the present invention exhibited good curability and coating quality even when the content of the organic solvent in the coating was reduced. .
In addition, the content of the organic solvent in the paint at the time of application could be reduced.

[0135]

The thermosetting coating composition of the present invention contains components (a) to (d) having a specific characteristic number and / or structure, and component (c) is component (c-1). ) And / or the component (d) is the component (d-1), so that the curability and coating quality of a so-called super-high solid paint having a very low content of an organic solvent, which has been impossible so far, have been impossible. Is good. In addition, the method for forming a coating film of the present invention uses the above-mentioned thermosetting coating composition, so that the content of the organic solvent in the coating when applied can be reduced.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 175/00 C09D 175/00 201/00 201/00 (72) Inventor Yoshifumi Ichinose Ikedanakamachi, Neyagawa-shi, Osaka 19-17 Inside Nippon Paint Co., Ltd. (72) Inventor Yuji Okura 19-17 Ikedanakacho, Neyagawa City, Osaka Prefecture Nippon Paint Co., Ltd. (72) Akihiro Kanekura 19-17 Ikedananakacho, Neyagawa City, Osaka Prefecture F-term (reference) in Nippon Paint Co., Ltd. DD181 DG221 DG261 DG262 FA041 FA042 FA061 FA062 FA091 FA092 FA101 FA102 FA111 FA112 FA151 FA152 FA181 FA182 FA211 FA212 FA231 FA232 FA251 FA 252 FA261 FA262 FA271 FA272 FA281 FA282 JB01 JC17 JC29 KA03 KA04 KA06 MA10 MA12 MA14 MA15 NA01 NA27 PB07 PC08

Claims (11)

[Claims] Claims: 1. A number average molecular weight of 300 to 3000, and
General formula 1 having an active methylene group or an active methine group: And / or general formula 2: (Wherein, R ¹ is an organic residue of a polyol, R ² is a hydrogen atom or an organic group which may contain an oxygen atom having 1 to 20 carbon atoms, and R ³ has a carbon atom number of 1 to 20). This represents an organic group not containing 6 hydroxyl groups and epoxy groups, m is 2 or more, and n is 1 or more. A plurality of R ² and R ³ may be the same or different.)
The component (a) represented by the formula, the number average molecular weight is 200 to 300.
0, two or more methacrylate groups and / or
Or a thermosetting coating composition containing a component (b) having an acrylate group, a component (c) having an onium salt, and a component (d) having an epoxy group and / or a 5-membered carbonate group. Non-aqueous dispersion (c-1) containing resin particles in which component (c) is insoluble in an organic solvent having an onium salt, and / or component (d) has an epoxy group and / or a 5-membered carbonate group Non-aqueous dispersion containing resin particles insoluble in organic solvent (d-1)
A thermosetting coating composition comprising: 2. The thermosetting coating composition according to claim 1, wherein the component (a) is obtained from malonic acid, a malonic acid ester compound, a malonic acid derivative or an ester compound of a malonic acid derivative, and a polyol. object. 3. The thermosetting coating composition according to claim 1, wherein the chemical structure of R ¹ of the component (a) has an alicyclic moiety in a linear or side chain. 4. The component (b) comprises (meth) acrylate ester of polyol, polyester (meth) acrylate resin, unsaturated polyester resin, epoxy (meth) acrylate resin, urethane (meth) acrylate resin, α, β- Acrylic resin containing unsaturated carbonyl group,
Polyether (meth) acrylate resin and (meth)
The thermosetting coating composition according to any one of claims 1 to 3, which is at least one selected from the group consisting of acrylate group-containing silicone resins. 5. The cation of the onium salt of the component (c) is at least one of a tertiary sulfonium cation, a quaternary phosphonium cation and a quaternary ammonium cation. A thermosetting coating composition according to one of the preceding claims. 6. The anion of the onium salt contained in the component (c) is at least one of a halide other than a fluoride, a carboxylate, a sulfonate, a sulfate, a nitrate or a phosphate.
6. The thermosetting coating composition according to any one of 5. 7. The non-aqueous dispersion (c-1) and / or the non-aqueous dispersion (d-1) have a solid content of 40% by weight or more and a viscosity at 20 ° C. of 10,000 mPa · s or less. The thermosetting coating composition according to any one of claims 1 to 6. 8. The total content of the non-aqueous dispersion (c-1) and / or the non-aqueous dispersion (d-1) is based on the total weight of the component (a) and the component (b). The thermosetting coating composition according to any one of claims 1 to 7, which is 10 to 150% by weight based on the solid content. 9. The thermosetting coating composition according to claim 1, which comprises an isocyanate compound, a melamine resin or tris (alkoxycarbonylamino) triazine. 10. A coating film forming method for applying the thermosetting coating composition according to any one of claims 1 to 9 to an object to be coated, wherein a thermosetting property at the time of the application is applied. A coating film forming method, wherein the coating composition has a coating solid content of 50% by weight or more. 11. A step (1) of applying a base paint on an object to be coated with an electrodeposition coating film and an intermediate coating film to form an uncured base coating film. A step (2) of applying a clear paint on the obtained uncured base coating film to form an uncured clear coating film;
And (3) simultaneously heating and curing the uncured base coating film and clear coating film obtained in (2) to obtain a coating film.
A method for forming a multilayer coating film comprising: wherein the clear coating material at the time of application is any one of claims 1 to 9.
The thermosetting coating composition according to any one of the above, wherein the solid content of the coating is 5
A method for forming a multilayer coating film, which is 0% by weight or more.