JPH05111668A - Coating method using resin composition for laminated coating - Google Patents

Abstract

PURPOSE:To improve stability in above coating of automobile bodies by coating the automobile bodies with a resin formed of a vinyl polymer having plural pieces of hemiacetal ester groups and hemiketal ester groups in the molecule, etc., and a compd. contg. plural pieces of epoxy groups in the molecule. CONSTITUTION:The automobile bodies are coated by using the resin compsn. for laminated coating formed by compounding the vinyl polymer having at least two pieces of the hemiacetal ester groups and/or hemiketal ester groups in one molecule, etc., or a polyether resin, polyester resin, polyamide resin, or polyurethane resin having the similar groups and the compd. contg. two pieces of the epoxy groups in one molecule. This resin compsn. for laminated coating has excellent storage stability as a one-pack type coating material and is, therefore, good in workability. The coating film is highly resistant to acids and weather.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method using a novel and useful resin composition for laminated coating. More specifically, a vinyl polymer having a specific group such as a hemiacetal ester group and / or a hemiketal ester group, and a polyester resin, a polyurethane resin, a polyether resin and / or a polyamide resin having such a specific group are used. A resin composition for layered coating, which is a one-part curable resin composition having excellent storage stability and curability, and which provides a cured film having various properties such as excellent acid resistance. And an improved method of layer coating.

The coating method of the present invention, which is carried out using such a useful resin composition for multilayer coating, is used in various fields for coatings such as car bodies and metal coatings.

[0003]

2. Description of the Related Art In recent years, mainly in the field of coatings such as automobile bodies and metal coatings, there has been a problem of so-called coating appearance deterioration, in which deterioration due to exposure, particularly deterioration of appearance due to acid rain, is caused. ing.

However, as long as the conventional acrylic polyol / melamine resin-based coating material is used, it has become impossible to satisfy the performance requirements required for maintaining the coating appearance.

In the midst of these movements, various curable coating materials such as a combination of a carboxyl group-containing polymer and an epoxy group-containing compound have been developed and studied, but such carboxyl group-containing compound / epoxy group-containing compound has been studied. The compound system is inferior in stability in one solution and has a serious defect that can be said to be fatal in terms of workability.

[0006]

Up to now, the only means for protecting the carboxyl groups in the carboxyl group-containing polymers has been to use trialkylsilyl ester groups exclusively.

However, such a vinyl-based polymer having a trialkylsilyl ester group is easily hydrolyzed by moisture in the air during storage to regenerate the carboxyl group. However, the long-term stability is poor.

[0008] Therefore, the problem to be solved by the present invention is to provide a vinyl polymer having a group in which a carboxyl group is protected in the form of a specific ester; and / or a carboxyl group is protected in the form of such a specific ester. For one-pack type multi-layer coating that has good storage stability and excellent curability by using a polyether resin, polyester resin, polyamide resin or polyurethane resin containing The resin composition, further, while forming a cured film excellent in acid resistance,
As a solvent-based resin composition, it is to provide a laminated coating method using a resin composition for laminated coating which can significantly reduce the composition viscosity as compared with the conventional combination of a carboxyl group-containing compound / polyepoxy compound. .

[0009]

Therefore, the present inventors have
Focusing on the problems to be solved by the invention as described above, as a result of repeated and diligent studies, the obtained vinyl polymer, polyether resin, polyester resin, polyamide resin and carboxyl group in the polyurethane resin, respectively, , A novel thing that is protected by a specific form, such as a hemiacetal ester group and / or a hemiketal ester group,

That is, a vinyl polymer, a polyether resin, a polyester resin, a polyamide resin and a polyurethane resin having a unique protective group called a hemiacetal ester group and / or a hemiketal ester group in the molecule are extremely stable. Moreover, the present invention has been completed here by discovering that the above-mentioned problems to be solved by the invention can be successfully solved.

That is, the present invention provides, inter alia, at least two of each of the general formulas

[0012]

[Chemical 4]

[Wherein, X in the formula, which may be the same or different, each represents an alkylene group having 1 to 10 carbon atoms, or an alkyl group, an alkoxyl group, an aryl group, or an alkanoyl group having 1 to 10 carbon atoms. It represents an alkylene group having 1 to 10 carbon atoms, which may or may not be substituted with at least one atomic group selected from the group consisting of an oxy group, an aryloxy group, an aralkyl group and a halogen atom. ] A hemiacetal ester group as shown in

[0014]

[Chemical 5]

[Wherein R 2 s, which may be the same or different, each represents a hydrogen atom or a carbon number of 1 to
And R3 is at least selected from the group consisting of an alkyl group having 1 to 22 carbon atoms, or a cycloalkyl group, an aralkyl group, an aryl group, an alkoxyl group, an alkanoyloxy group and a halogen atom. It represents an alkyl group having 1 to 22 carbon atoms, which may or may not be substituted with one kind of atomic group. ] A hemiacetal ester group as shown in

[0016]

[Chemical 6]

[Wherein, X in the formula is as defined above, and R 1 s may be the same or different and each may be substituted with a cycloalkyl group, an aralkyl group or an alkoxyl group. It represents an alkyl group having 1 to 18 carbon atoms which may not be substituted. ] Or a general formula

[0018]

[Chemical 7]

[Wherein R2 is as defined above, and R3 is an alkyl group having 1 to 22 carbon atoms, or a cycloalkyl group, an aralkyl group, an aryl group, an alkoxyl group, an alkanoyloxy group. Represents an alkyl group having 1 to 22 carbon atoms, which may or may not be substituted with at least one atomic group selected from the group consisting of a group and a halogen atom, and
R5 represents an alkyl group having 1 to 10 carbon atoms. ] The vinyl polymer (A) having a hemiketal ester group as shown in, or having at least two hemiacetal ester groups and / or hemiketal ester groups as described above in one molecule. ,
A resin composition for laminated coating comprising a polyether resin, a polyester resin, a polyamide resin and / or a polyurethane resin (B) and a compound (C) having at least two epoxy groups in one molecule as essential components. It is intended to provide a coating method using objects,

Further, a vinyl polymer (A) having a specific group such as a hemiacetal ester group and / or a hemiketal ester group in such various forms as described above, or such various forms as described above. A polyether resin having a specific group of hemiacetal ester group and / or hemiketal ester group,
Polyester resin, polyamide resin and / or polyurethane resin (B) and epoxy group-containing compound (C)
Another object of the present invention is to provide a coating method using a resin composition for laminated coating, which comprises, as an essential component, and a curing catalyst (D).

In the present invention, the term "multilayer coating" means, for example, first coating a substrate (base material) with a crosslinkable base coat paint containing a brightening agent and / or a coloring pigment, and then coating In a wet state, a thermosetting clear coat paint (clear paint 1) is applied to the surface of the base coat to be crosslinked, that is, a coating method by a so-called 2 coat 1 bake system;

Alternatively, a coating method by a so-called 3 coat 2 bake system in which a thermosetting clear coat paint (clear paint 2) is further applied to the thus obtained laminated coated product to crosslink it;

Alternatively, first, a crosslinkable base coat paint in the form of a mixture of a brightening agent and / or a coloring pigment is applied on an object to be coated (base material) to crosslink it, and then a heat treatment is applied to the basecoat coated surface. It refers to various systems such as a coating method using a so-called two-coat, two-bake system, in which a curable clear coat paint is applied and crosslinked.

The vinyl-based polymer (A) mentioned above refers to a polymer having a specific group of at least two hemiacetal ester groups and / or hemiketal ester groups per molecule. As the polymer (A), only typical ones are exemplified by acrylic polymers, vinyl ester polymers, α-olefin polymers, fluoroolefin polymers or chlorinated olefin polymers. And so on.

In order to prepare the vinyl polymer (A), for example, homopolymerization of vinyl monomers having various hemiacetal ester groups or hemiketal ester groups represented by the above-mentioned general formula is carried out. It is possible to employ a method in which the carboxyl group in the polymer containing a carboxyl group prepared in advance is converted into a hemiacetal ester group or a hemiketal ester group, or the like.

Further, it is selected from the group consisting of a polyether resin, a polyester resin, a polyamide resin and a polyurethane resin, each of which has at least two hemiacetal ester groups and / or hemiketal ester groups in one molecule. To prepare at least one resin (B), a method of reacting each resin having a carboxyl group with an α, β-ethylenically unsaturated ether compound, or a method of reacting various resins having a carbosyl group with α-halogeno A method such as reaction with an ether compound can be adopted, but the method is particularly simple.

Of these, as vinyl monomers having a hemiacetal ester group represented by the general formula [I] or [III-1], which are used first or in the case of the following method, for example, In the carboxyl group-containing monomers, or having a carboxyl group, polyether resin, polyester resin, polyamide resin and polyurethane resin, respectively, for example,
General formula

[0028]

[Chemical 8]

[Wherein Y in the formula may be the same or different and each is an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an aryl group, an alkanoyloxy group, an aryloxy group, an aralkyl group and a halogen. It represents an alkylene group having 1 to 9 carbon atoms, which may or may not be substituted with at least one atomic group selected from the group consisting of atoms, and Z is a hydrogen atom or 1 to 9 carbon atoms. An alkyl group, an alkoxyl group 10,
It represents an aryl group, an alkanoyloxy group, an aryloxy group, an aralkyl group or a halogen atom. ] Or a compound of the general formula

[0030]

[Image Omitted] R2-CH = CH-OR3 [V] [wherein R2 and R3 in the formula are as described above. ] The compound etc. which are obtained by carrying out an addition reaction of the compound shown by these are mentioned.

Such addition reaction products, that is, the hemiacetal ester group-containing vinyl-based monomers represented by the above-mentioned general formula [I], are particularly representative as compounds obtained by reaction with methacrylic acid. If you stop by exemplifying only

[0032]

[Chemical 10]

[0033]

[Chemical 11]

Or

[0035]

[Chemical 12]

The number of carbon atoms of X in the above-mentioned general formula [I] is 1-10, preferably 2-6.
Within the range, it is appropriate.

Next, as the hemiacetal ester group-containing vinyl monomers represented by the above-mentioned general formula [III-1], particularly as an addition reaction product with methacrylic acid, that is, as a methacrylic acid ester, To give an example of only

[0038]

[Chemical 13]

[0039]

[Chemical 14]

[0040]

[Chemical 15]

Or

[0042]

[Chemical 16]

And so on.

R 2 in the above general formula [III-1]
As, respectively, a hydrogen atom or a carbon number of 1 to
An alkyl group of 10 is preferably an alkyl group having 1 to 6 carbon atoms, and R3 is preferably an alkyl group having 1 to 22 carbon atoms, preferably 1 to 12 carbon atoms. Suitable alkyl groups are

On the other hand, the hemiketal ester group-containing vinyl monomers represented by the above general formula [II] are, for example, carboxyl group-containing monomers,

The hemiketal ester group-containing polyether resin, polyester resin, polyamide resin and / or polyurethane resin represented by the general formula [II] is, for example, a carboxyl group-containing polyether resin or polyester resin. , The polyamide resin and the polyurethane resin are respectively represented by the general formula [VIII]

[0047]

[Chemical 17]

[However, R 1, Y and Z in the formula are as defined above. ] It is prepared by subjecting a compound represented by

As such an addition reaction product, that is, the hemiketal ester group-containing vinyl monomers represented by the above-mentioned general formula [II], particularly, a compound obtained by a reaction with methacrylic acid is typical. If you stop by exemplifying only

[0050]

[Chemical 18]

[0051]

[Chemical 19]

Or

[0053]

[Chemical 20]

1-alkoxy-1-methacryloyloxycycloalkanes having up to 18 carbon atoms, such as:

[0055]

[Chemical 21]

Or

[0057]

[Chemical formula 22]

Having a substituent other than the 1 position, such as
So-called substituent-containing 1-alkoxy-1-methacryloyloxycycloalkanes and the like are included.

The number of carbon atoms of X in the above-mentioned general formula [II] is in the range of 1 to 10, preferably 2 to 6.
Within the range, it is appropriate.

On the other hand, the hemiketal ester group-containing vinyl-based monomers represented by the above general formula [III-2] are, for example, carboxyl group-containing monomers,

The hemiketal ester group-containing polyether resin, polyester resin, polyamide resin and / or polyurethane resin represented by [III-2] is, for example, a carboxyl group-containing polyether resin, polyester resin or polyester resin. Resin, polyamide resin and / or polyurethane resin, respectively, for example,
General formula

[0062]

R2-CH = CR5-OR3 [X] [wherein R2, R3 and R5 in the formula are all
It shall be as described above. ] It is prepared by subjecting a compound represented by

Such addition reaction products, that is, the hemiketal ester group-containing vinyl monomers represented by the above-mentioned general formula [III-2] are particularly compounds obtained by reaction with methacrylic acid. To give an example of only typical ones,

[0064]

[Chemical formula 24]

[0065]

[Chemical 25]

Or

[0067]

[Chemical formula 26]

And so on.

The various monomers as listed above are vinyl polymers containing a hemiacetal- and / or hemiketal ester group represented by the general formula [I], [II] or [III], respectively. Of the ester group-containing vinyl monomers to be prepared, only the methacrylic acid derivative is merely used. In addition to these, acrylic acid-, crotonic acid- or carboxyethyl (meth) acrylate Kind;

Monovinyl esters of various saturated dicarboxylic acids such as succinic acid, adipic acid or sebacic acid; maleic acid, fumaric acid or itaconic acid,
Various unsaturated dicarboxylic acids; Half esters of the above-listed unsaturated dicarboxylic acids with monohydric alcohols;

Alternatively, a carboxyl group-containing monomer such as an addition reaction product of a hydroxyl group-containing monomer typified by 2-hydroxyethyl (meth) acrylate and an acid anhydride such as succinic anhydride or phthalic anhydride. For various compounds such as monomers, the above-mentioned general formula [IV],
Needless to say, various monomers in the form obtained by addition reaction of various compounds represented by [V], [VI] or [VII] can also be used.

Hemiacetals such as those listed above
Alternatively, by using a hemiketal ester group-containing vinyl polymer, or if necessary, as described later, other monomers copolymerizable with the ester group-containing monomer may be added. By using the vinyl polymer (A) of the present invention
In order to prepare the resin, a known and conventional polymerization method can be applied, and each of the carboxyl groups used in preparing the hemiacetal ester group- and / or hemiketal ester group-containing resin (B) can be used. The resin is prepared by a known and conventional method.

To produce the vinyl polymer (A),
According to the suspension polymerization method, emulsion polymerization method, bulk polymerization method or solution polymerization method, radical polymerization method, ionic polymerization method or photopolymerization method can be used.

As the above-mentioned other copolymerizable monomers to be used at that time, only typical ones will be exemplified. Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) ) Acrylate,
C1-C22 alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate or lauryl (meth) acrylate; cyclopentyl (meth)
Alicyclic alkyl (meth) acrylates such as acrylate, cyclohexyl (meth) acrylate or isobornyl (meth) acrylate; benzyl (meth)
Including aralkyl (meth) acrylates such as acrylate or phenethyl (meth) acrylate,

2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4
-Various hydroxyl group-containing monomers such as hydroxybutyl (meth) acrylate, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether or 2-hydroxyethyl allyl ether;

Alkyl esters of crotonic acid such as methyl crotonic acid or ethyl crotonic acid; unsaturated dicarboxylic acids such as dimethyl maleate, dibutyl maleate, dimethyl fumarate, dibutyl fumarate, dimethyl itaconate or dibutyl itaconate Dialkylesters of styrene; various aromatic vinyl monomers such as styrene, p-tert-butylstyrene, α-methylstyrene or vinyltoluene; (meth) acrylamide or N, N-dimethyl (meth) acrylamide , Various (meth) acrylamides;

Various cyano group-containing monomers such as (meth) acrylonitrile or crotononitrile; vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinyl chloride or chloride Like vinylidene,
Various haloolefins; ethylene, propylene, isobutylene or 1-butene, various α-olefins; or vinyl acetate, vinyl propionate, vinyl pivalate or vinyl versatate,
Various carboxylic acid vinyl esters,

Further, various alkyl- or cycloalkyl vinyl ethers such as ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether or cyclohexyl vinyl ether can be used.

Furthermore, various carboxyl group-containing monomers as described above can be copolymerized in an amount within the range that does not impair the characteristics of the present invention. To prepare vinyl polymers by the above-mentioned method, a carboxyl group-containing unit amount such as used in obtaining various hemiacetal- or hemiketal ester group-containing vinyl monomers as described above is used. A homopolymer of the body, or a copolymer of such a carboxyl group-containing monomer and another monomer copolymerizable with the monomer,
The above general formulas [IV], [V], [VI] or [X]
It suffices to add various compounds such as

Such an addition reaction is carried out by adding 4 parts of the above-mentioned carboxyl group-containing (co) polymer solution dissolved in a solvent in the presence of a so-called acid catalyst such as hydrochloric acid, sulfuric acid or phosphoric acid.
At a reaction temperature of about 0 to 100 ° C., various compounds represented by the above general formulas [IV], [V], [VI] or [X] are added dropwise, and the reaction is performed for about 5 to 10 hours. It's like punishment.

As the solvent to be used here, only typical ones will be exemplified. For example, toluene, xylene, cyclohexane, n-hexane or octane can be used.
Various hydrocarbon systems; various ester systems such as ethyl acetate, butyl acetate or amyl acetate; or acetone,
Of course, various ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, and cyclohexanone may be used alone or in combination of two or more kinds.

Thus, the number average molecular weight of the vinyl polymer (A) obtained by the above method or is suitably in the range of 300 to 300,000.

When it is less than 300,
It is inferior in curability, and is inferior in stability when, for example, water is present.
If it exceeds 0, the workability is inevitably deteriorated, and in any case, it is not preferable.

The amount of the hemiacetal- or hemiketal ester group introduced into the vinyl polymer (A) is the proportion of the monomers corresponding to the monomer structure into which these groups are introduced. Is appropriately in the range of 1 to 100% by weight, preferably in the range of 2 to 100% by weight.

When the amount is less than 1% by weight, when used in combination with the epoxy group-containing compounds (C), which will be described later, the problem of lowering the curability arises. This is because the object of the invention cannot be achieved and the effects of the present invention cannot be obtained.

On the other hand, the number average molecular weight of the resin (B) having at least two hemiacetal ester groups and / or hemiketal ester groups is 250
To 50,000, more preferably 30
The range of 0 to 30,000 is suitable.

When it is less than 250, the volatilization of the component (B) is large at the time of baking, while when it exceeds 50,000, the workability is inevitably deteriorated. Absent.

Then, only representative examples of the above-mentioned epoxy-containing compounds (C) are exemplified, and aliphatic epoxy glycols such as ethylene glycol, hexanediol, neopentyl glycol or hydrogenated bisphenol are listed. Diglycidyl ethers; diglycidyl ethers of halogen-substituted aliphatic glycols such as dibromoneopentyl glycol; or 4,4′-hexafluoroisopropylidenediphenol, hydroquinone, catechol, resorcin, bisphenol A, bisphenol S or bisphenol F Such as halogen (un) substituted aromatic diols,

Alternatively, diglycidyl ethers of aromatic diols such as ethylene oxide- or propylene oxide adducts of the above halogen (un) substituted aromatic diols; poly (triol) such as glycerin or trimethylolpropane. Glycidyl ethers; Polyglycidyl ethers of polyols such as sorbitol, sorbitan or pentaerythritol; Diglycidyl ethers such as ether-substituted aliphatic glycols (aliphatic diols) such as polyethylene glycol, polypropylene glycol or polytetraethylene glycol Tris (2-hydroxyethyl) isocyanurate polyglycidyl ethers;

Diglycidyl esters of aliphatic or aromatic dicarboxylic acids such as adipic acid, phthalic acid or terephthalic acid; hydrocarbons such as butadiene, hexadiene, octadiene, dodecadiene, cyclooctadiene, α-pinene or vinylcyclohexene. Bisepoxides of the systematic diene; epoxyhexylmethanol esters of epoxy group-containing carboxylic acids such as epoxycyclohexanecarboxylic acid, epoxycyclohexanedicarboxylic acid or 6- (epoxycyclohexanecarbohexanoic acid); butanetetracarboxylic acid or propanetricarboxylic acid Epoxyhexyl methanolic esters of polycarboxylic acids, such as acids;

Alternatively, obtained from an epoxy group-containing vinyl monomer, such as glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, vinylcyclohexene oxide or glycidyl vinyl ether, or containing the above-mentioned epoxy group. Epoxy group-containing (co) polymers and the like obtained from a combination of the vinyl monomer and the above-mentioned vinyl monomers, which are copolymerizable with the vinyl monomer.

To prepare the resin composition for laminate coating used in the present invention from the components (A) or (B) and (C) listed above, these components (A) or The component (B) and the component (C) have an equivalent ratio of the hemiacetal group and / or hemiketal ester group of the component (A) or (B) to the epoxy group of the component (C) of 1: 0. .2 to 1: 5, preferably,
It suffices to mix them so as to be 1: 0.4 to 1: 2.5.

The resin composition for laminated coating used in the present invention comprises the above-mentioned component (A) or (B),
The component (C) can be used in a form in which the curing catalyst (D) is further contained, and when it is used in such a form, it can be cured at a lower temperature. .

This is also one of the effects of the present invention.

The curing catalyst (D) acts as a catalyst for efficiently deprotecting the above-mentioned hemiacetal- or hemiketal ester group, and
The form acting as a catalyst for promoting the reaction between the epoxy group and the carboxyl group is designated.

Among the curing catalysts (D), first, only those particularly representative as the catalyst acting as a catalyst for deprotecting the hemiacetal- or hemiketal ester group will be exemplified. Various organic sulfonic acids such as sulfonic acid, propanesulfonic acid, toluenesulfonic acid, naphthalenedisulfonic acid, trifluoromethanesulfonic acid or trichloromethanesulfonic acid; various organic phosphoric acids such as methylphosphoric acid, isopropylphosphoric acid or diisopropylphosphoric acid and the like Esters of

1,8-diazabicyclo [5.4.0] undecene-7 (DBU), 1,5-diazabicyclo [4.3.0] nonene-5 (DBN) or 1,4-
Diazabicyclo [2.2.2] octane (DABCO)
Various organic tertiary amines such as; acetic acid, butyric acid, 2,2
Various organic carboxylic acids such as dimethylpentanoic acid or benzoic acid; various metal acid salts such as tin octylate, magnesium naphthenate, zinc octylate or calcium octylate; imidazole, N-methylimidazole, 1,2 Various imidazoles such as -dimethyl-imidazole or 2,4-dimethylimidazole;

Various salts obtained from the above acids and bases; tetramethylammonium salt, tetraethylammonium salt, trimethyl (2-hydroxypropyl) ammonium salt, tetrabutylammonium salt, tetrakis (hydroxymethyl) ammonium salt Various quaternary ammonium salts such as salts, cyclohexyltrimethylammonium salt or o-trifluoromethylphenyltrimethylammonium salt;

Alternatively, a tetramethylphosphonium salt,
Tetraethylphosphonium salt, tetrapropylphosphonium salt, tetrabutylphosphonium salt, trimethyl (2
Various phosphonium salts such as -hydroxypropyl) phosphonium salt, triphenylammonium salt or benzyltriphenylphosphonium salt.

Next, only the particularly representative ones which act as a catalyst for accelerating the reaction between the epoxy group and the carboxyl group will be illustrated. For example, trimethylphosphine, triethylphosphine or triphenylphosphine. , Various organic phosphines; tetramethylammonium salt, tetrabutylammonium salt,
Trimethyl (2-hydroxypropyl) ammonium salt, cyclohexyl trimethyl ammonium salt, tetrakis (hydroxymethyl) ammonium salt or o-
Various quaternary ammonium salts such as trifluoromethylphenyltrimethylammonium salt;

Imidazole, N-methylimidazole,
Various imidazoles such as 2,4-dimethylimidazole or 3,5-diethylimidazole; Various metal alcoholates such as tetraisopropyl aluminate or tetraisopropyl titanate; or tetramethylphosphonium salt, tetraethylphosphonium salt, tetrapropyl Phosphonium salt, tetrabutylphosphonium salt, trimethyl (2-hydroxypropyl)
Various phosphonium salts such as phosphonium salt, triphenylphosphonium salt or benzyltriphenylphosphonium salt are used. In addition to these typical curing catalysts, atomic groups or groups that exhibit the above-mentioned catalytic effect are also included. Various polymers and polymer compounds having, for example, are also effective catalysts.

Various curing catalysts (D) as listed above
In order to prepare the resin composition for laminated coating used in the present invention in a form in which is also contained as an essential constituent component, first, the above-mentioned (A) or (B) component and (C) component are previously prepared. As described above, after being mixed, the component (D) is added to 100 g of the total solid content (total solid content) of both components (A) or (B) and (C). The component (D) may be blended in such a ratio that the amount of the atomic group or group exhibiting the catalytic effect is 30 mmol or less, preferably 15 mmol or less.

When the amount of the component (D) used exceeds 30 millimoles (0.03 moles) and becomes too large, the storage stability of the resin composition for laminated coating is inevitably extremely lowered. In addition, the water resistance of the cured product is significantly reduced, which is not preferable in any case.

The thus-obtained resin composition for laminate coating used in the present invention contains the curing catalyst (D), whether or not it is used, and the components (A) or (B) and (C). By baking for 30 seconds to 1 hour in a temperature range of about 100 to 250 ° C. according to the functional group content, etc., it is possible to provide a sufficiently cured cured film having excellent acid resistance. Is.

The resin composition for laminated coating used in the present invention may be an organic solvent solution type, an organic solvent dispersion type, a solventless liquid type or a solventless solid type, or a powder type depending on its application. In any form such as (powder),
Can be used.

Furthermore, the resin composition for laminated coating used in the present invention may be blended with known and commonly used additives such as a leveling agent and an ultraviolet absorber, if necessary.

Thus, the resin composition for laminated coating used in the present invention is a so-called laminated type in which a coating film is formed by a two-coat one-bake system, a two-coat two-bake system, or a three-coat two-bake system. It can be used as a top clear coat for painting.

At this time, the coating composition for base coat is not particularly limited, and any composition can be used as long as it can form a coating film. As typical examples of the base coat composition, a hydroxyl group-containing resin and a melamine resin; a hydroxyl group-containing resin and a polyisocyanate; a carboxyl group-containing resin and an epoxy group-containing resin; or a hydrolyzable silyl group-containing resin. Etc., and those in which at least one of organic, inorganic, and metallic pigments is mixed with a combination of two or more thereof.

[0109]

EXAMPLES Next, the present invention will be explained more concretely by reference examples, examples, comparative examples, application examples and comparative application examples. In the following, parts and% are, unless otherwise specified,
All are based on weight.

Reference Example 1 [Preparation example of hemiacetal ester group-containing copolymers (A)] 500 parts of xylene was placed in a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel and a nitrogen gas introducing tube. Then, 300 parts of butyl acetate were charged, and the temperature was raised to 110 ° C. under aeration of nitrogen gas.

Then, at the same temperature, 85 parts of styrene, n-
424 parts of butyl methacrylate, 210 parts of n-butyl acrylate, 1 represented by the above formula [VII-4]
281 parts of-(i-butoxy) ethyl methacrylate,
A mixture of 200 parts of xylene, 5 parts of t-butylperoxyoctoate (TBO) and 20 parts of t-butylperoxybenzoate (TBB) was added dropwise over 4 hours.

Thereafter, the mixture was kept at the same temperature for 15 hours, the nonvolatile content (NV) was 50%, the Gardner viscosity (VIS) at 25 ° C. was G 2 -H, and the number average molecular weight (Mn ) Was obtained to obtain a solution of the target polymer of 7,570. Hereinafter, this is abbreviated as resin (A-1).

Reference Example 2 (Same as above) As a monomer for copolymerization, 249 of 1- (ethoxy) ethyl methacrylate represented by the above formula [VII-1].
Parts, 89 parts of styrene, 4 parts of n-butyl methacrylate
NV in the same manner as in Reference Example 1 except that 43 parts and 219 parts of n-butyl acrylate were used.
Is 49.9%, VIS is OP, and Mn is 8,
A solution of the target polymer of 300 was obtained. Hereinafter, this is abbreviated as resin (A-2).

Reference Example 3 (same as above) As the copolymerization monomer, 377 of the hemiacetal ester group-containing monomers represented by the above formula [VII-8].
Parts, 75 parts of styrene, 3 parts of n-butyl methacrylate
NV in the same manner as in Reference Example 1 except that 70 parts and 178 parts of n-butyl acrylate were used.
Of 50.0%, VIS is P, and Mn is 8,500 to obtain a solution of the target polymer. Hereinafter, this is abbreviated as resin (A-3).

Reference Example 4 (same as above) A reaction vessel similar to that of Reference Example 1 was charged with 950 parts of xylene and 450 parts of butyl acetate, and the mixture was placed under a nitrogen atmosphere at 1
The temperature was raised to 10 ° C.

Then, at the same temperature, 74 parts of styrene, n-
125 parts of butyl methacrylate, 313 parts of n-butyl acrylate, 1 represented by the above formula [VII-4]
488 parts of-(i-butoxy) ethyl methacrylate,
60 parts of TBO, 10 parts of TBB and 10 parts of xylene
A mixture of 0 parts was added dropwise over 6 hours.

After the completion of dropping, the temperature was kept at the same temperature for 15 hours, NV was 39.4%, and VIS was A3 -A4.
And a solution of the target polymer having Mn of 2,930 was obtained. Hereinafter, this is abbreviated as resin (A-4).

Reference Example 5 (same as above) In a 2 liter autoclave, the formula

[0119]

[Chemical 27]

192 parts of the compound represented by the formula: 288 parts of ethyl vinyl ether, 480 parts of chlorotrifluoroethylene, 640 parts of methyl isobutyl ketone and 19.2 parts of 2,2'-azobis (2,4-dimethylvaleronitrile). 2 parts were charged and a polymerization reaction was carried out at 60 ° C. for 20 hours, NV was 58.0%, VIS was T, and
A solution of the target polymer having Mn of 20,000 was obtained. Hereinafter, this is abbreviated as resin (A-5).

Reference Example 6 [Preparation Example of Copolymers (A) Containing Hemicetal Group] As a monomer for copolymerization, 328 of the monomer containing a hemiketal ester group represented by the above formula [IX-1] is used. Parts, 80 parts of styrene, 400 parts of n-butyl methacrylate and 192 parts of n-butyl acrylate, except that NV was 50.
A solution of the target polymer having 0%, VIS, OP, and Mn of 8,300 was obtained. Hereinafter, this is a resin (A-
It is abbreviated as 6).

This was analyzed by infrared absorption spectrum analysis (IR spectrum analysis)
It was confirmed that m-1 (benzene ring), 1090 cm-1 (-OCH3) and 1720 cm-1 (ester bond) had a specific absorption.

Reference Example 7 [Preparation example of resin (B) containing hemiacetal ester group] A reactor was charged with 1,000 parts of polyethylene glycol having a molecular weight of 1,000 and 200 parts of succinic anhydride.
The temperature was raised to 140 ° C. with stirring under a nitrogen atmosphere.

Then, the reaction was carried out at the same temperature for 4 hours to obtain a polyether having two carboxyl groups per molecule. Hereinafter, this is abbreviated as an intermediate (M-1). Furthermore, to the intermediate (M-1), 400 of ethyl acetate was added.
Parts and 1 part of acetyl chloride, and while stirring, 4
Keeping at 0 ° C., 158.4 parts of ethyl vinyl ether was added dropwise over 3 hours.

After that, when the reaction was further continued for 4 hours, Mn was 1,350 and NV was 76.2 having two acetal ester groups per molecule.
% Polyether resin was obtained. Hereinafter, this is abbreviated as resin (B-1).

Reference Example 8 (same as above) A reactor was charged with 476 parts of an adduct of trimethylolpropane and ε-caprolactone in a molar ratio of 1: 3 and 300 parts of succinic anhydride, and the mixture was stirred under a nitrogen atmosphere to give 14
The temperature was raised to 0 ° C.

Then, the reaction was carried out at the same temperature for 4 hours to obtain a polyester resin having 3 carboxyl groups per molecule. Hereinafter, this is abbreviated as an intermediate (M-2).

Further, to this intermediate (M-2), 500 parts of ethyl acetate and 1 part of acetyl chloride were added, and the mixture was kept at 40 ° C. with stirring to obtain 315 parts of isobutyl vinyl ether for 3 hours. Was dropped.

After that, the reaction was continued for further 4 hours to obtain a polyester resin having 3 acetal ester groups per molecule and having Mn of 1,100 and NV of 67.7%. Hereafter, this is resin (B-2)
Is abbreviated.

Reference Example 9 [Preparation example of resin (B) containing hemiketal ester group] 1,500 parts of polypropylene glycol having Mn of 500 and 3 parts of hexamethylene diisocyanate were placed in a reactor.
36 parts and 0.9 part of dibutyltin dilaurate were charged, and the temperature was raised to 100 ° C. with stirring under a nitrogen atmosphere.

Then, after reacting at the same temperature for 8 hours, 500 parts of butyl acetate, 9 parts of triphenylphosphine and 296 parts of phthalic anhydride were added, and 120 parts of
The temperature was raised to 0 ° C., and the reaction was carried out at the same temperature for 6 hours to obtain a polyurethane resin having two carboxyl groups per molecule. Hereinafter, this is abbreviated as an intermediate (M-3).

Further, to the intermediate (M-3), 500 parts of butyl acetate and 2.3 parts of acetyl chloride were added, and the mixture was maintained at 40 ° C. with stirring to give 17 parts of dihydropyran.
6.4 parts was added dropwise over 3 hours.

After that, the reaction was continued for a further 4 hours to obtain a polyurethane resin having 2 hemiketal ester groups per molecule and having Mn of 2,300 and NV of 69.5%. . Hereinafter, this is a resin (B-3)
Is abbreviated.

Reference Example 10 (Same as above) A reactor was charged with 776 parts of dimethyl terephthalate, 1,6.
— Hexanediol (361 parts), ethylene glycol (126 parts) and zinc acetate (2.5 parts) were charged, and the methanol removal reaction was performed at 160 to 210 ° C. under a nitrogen atmosphere.

Then, the reaction mixture was kept at 160 ° C. to obtain 192 parts of trimellitic anhydride and 1 part of succinic anhydride.
00 parts was added and the reaction was carried out at the same temperature for 3 hours,
A polyester resin having 3 carboxyl groups per molecule was obtained. Hereinafter, this is abbreviated as an intermediate (M-4).

Further, to this intermediate (M-4), 500 parts of butyl acetate and 1.5 parts of acetyl chloride were added, and the mixture was maintained at 40 ° C. with stirring, and 227 parts of 2-methoxypropene was added to 3 parts. Dropped over time.

After that, the reaction was continued for a further 4 hours to obtain a polyester resin having 3 hemiketal ester groups per molecule, Mn of 1,500 and NV of 74.7%. . Hereinafter, this is a resin (B-4)
Is abbreviated.

Reference Example 11 [Preparation Example of Epoxy Group-Containing Polymers (C)] In a reaction vessel similar to that of Reference Example 1, 1,400 parts of xylene was charged and heated to 125 ° C. under a nitrogen atmosphere. .

Then, at the same temperature, 100 parts of styrene,
210 parts of n-butyl methacrylate, 184 parts of n-butyl acrylate, 50 parts of glycidyl methacrylate
A mixture of 6 parts, 60 parts of TBO, 10 parts of di-tert-butyl peroxide and 100 parts of xylene was added dropwise over 6 hours.

After the dropping, the temperature was kept at the same temperature for 15 hours, NV was 41.7%, and VIS was A4 -A5.
And a solution of the target polymer having Mn of 2,930 was obtained. Hereinafter, this is abbreviated as resin (C-1).

Reference Example 12 (Same as above) Except that 100 parts of styrene, 520 parts of n-butyl methacrylate, 127 parts of n-butyl acrylate and 253 parts of glycidyl methacrylate were used as the monomers for copolymerization. In the same manner as in Reference Example 11, NV is 52.8%, VIS is G-H2, and
A solution of the target polymer having Mn of 8,200 was obtained. Less than,
This is abbreviated as resin (C-2).

Reference Example 13 (same as above) In a reactor, 500 parts of xylene and 30 parts of butyl acetate were added.
0 part was charged and the temperature was raised to 110 ° C. under a nitrogen atmosphere.

Next, 100 parts of styrene, 253 parts of n-butyl methacrylate, t-butyl peroxy-2
A mixture of 20 parts of ethylhexanoate, 5 parts of TBB and 200 parts of xylene was added dropwise over 4 hours.

After that, the reaction was continued at the same temperature for 10 hours to obtain a solution of epoxy group-containing acrylic polymer having NV of 50% and Mn of 8,150. Hereinafter, this is abbreviated as resin (C-3).

Reference Example 14 (same as above) In a 1 liter stainless steel autoclave sufficiently substituted with nitrogen gas, 75 parts of ethyl vinyl ete, 75 parts of glycidyl vinyl ether, "Veova 9" (made by Shell Co., Netherlands) , A vinyl ester of a branched fatty acid having an alkyl group C8), and 3 parts of butyl acetate.
33 parts and 10 parts of azobis (2,4-dimethylvaleronitrile) were charged.

Then, 250 of the chlorotrifluoroethylene liquefied and collected was injected under pressure and stirred at 60 ° C. for 15 minutes.
After reacting for a time, unreacted chlorotrifluoroethylene was purged with nitrogen.

Further, xylene was added so that NV was 50% to obtain a solution of epoxy group-containing fluoroolefin copolymer having Mn of 20,000. Hereinafter, this is abbreviated as resin (C-4).

Reference Example 15 (Preparation Example of Carboxyl Group-Containing Vinyl Polymers) In this example, the carboxyl formed by deprotecting the hemiacetal ester groups in the resins (A-1) and (A-2) It is an example of preparation of control polymers having the same composition as the group-containing vinyl polymers.

First, in a reaction vessel similar to that of Reference Example 1, 500 parts of xylene and 300 parts of isobutanol were charged, and the temperature was raised to 110 ° C. under a nitrogen atmosphere. At this temperature, 100 parts of styrene and n were added. -A mixture of 500 parts of butyl methacrylate, 247 parts of n-butyl acrylate, 153 parts of methacrylic acid, 20 parts of TBO, 5 parts of TBB and 200 parts of xylene was added dropwise over 4 hours.

Thereafter, the mixture was kept at the same temperature for 15 hours to obtain a solution of a control polymer having NV of 51.3%, VIS of XY2 and Mn of 7,800. . Hereinafter, this is abbreviated as resin (A'-1).

Reference Example 16 (Preparation Example of Hydroxy Group-Containing Vinyl Polymers) As a monomer for copolymerization, 100 parts of styrene, 500 parts of n-butyl methacrylate, 240 parts of n-butyl acrylate, and 2-hydroxy were used. 1 of ethyl methacrylate
NV was 51.0% in the same manner as in Reference Example 9 except that 50 parts and 10 parts of acrylic acid were used.
And VIS is OP and Mn is 8,300.
A solution of the reference polymer was obtained. Hereafter, the resin (Ref
-1) is abbreviated.

Examples 1 to 8 Component (A), component (C), component (D) and thinner were mixed in a ratio as shown in Table 1 by a conventional method, and NV was 46.5%. A resin composition for laminated coating used in the method of the present invention was prepared.

[0153]

[Table 1]

<< Footnote >> All of the "compounds" in the table are
Means "part". Compound (C-5) ... "Eporide GT-401"
[Daicel KK-made alicyclic epoxy resin having four epoxy groups per molecule; epoxy equivalent = 223] Compound (D-1) ..... triphenylphosphine compound (D-2) ..... DBU paratoluene sulfonate

[0155]

[Table 2]

Then, using each of the resin compositions for laminate coating thus obtained as a top coat, 2 coats and 1 bake finish, or 2 coats 2 were prepared, respectively.
The performance of the coating film obtained by baking was evaluated.

By the way, the coated plate used in this case was an electrodeposition coated plate such as "Beckolite GF-542" (hydroxyl group-containing polyester resin manufactured by Dainippon Ink and Chemicals, Inc.), "Super Betukamine L-". 117-60 "(butyl etherified melamine resin manufactured by the same company; nonvolatile content = 6)
(0%) and carbon black, so-called intermediate coating paint was applied and baked.

As the base paint, "Acrydeik 47-712" (hydroxyl group-containing acrylic resin manufactured by Dainippon Ink and Chemicals, Inc.), "Super Betukamine"
L-117-60 "and" aluminum paste 7160.
A metallic base coating containing NS "(aluminum paste manufactured by Toyo Aluminum Co., Ltd.) was used.

The results are summarized in Table 2. However, (1) and (2) in Table 2 are data in the case of 2 coat 1 bake finish, while (3) and (4) in Table 2 are in the case of 2 coat 2 bake finish. It is data.

The "storage stability" data listed in the table shows that the viscosity of each resin composition for lamination coating after storage at 40 ° C. for 20 days was
It is a value (quotient) obtained by dividing by the initial viscosity of each of these various types of resin compositions for laminated coating, and is represented by this value.

[0161]

[Table 3]

<< Footnote >> All of the "compounds" in the table are
Means "part". CPS: Abbreviation for "centipoise" Storage stability: A value obtained by dividing the viscosity (temporal viscosity) after maintaining the resin composition for laminated coating at 40 ° C for 20 days by the initial viscosity. (Quotient) Erichsen value ……… Unit is “millimeter (mm)” Impact resistance ………… With 1/2 inch notch, 500
Drop distance under a load of g (cm) Thinner resistance ………… Visually judge the appearance of the coating film after 50 times of xylene rubbing Acid resistance ………… Droplet of 10% sulfuric acid aqueous solution on the coating film After placing, this coating film is left in a hot air dryer at 60 ° C for 30 minutes, then the coating film is washed with water and dried to visually determine the appearance of the coating film.

[0163]

[Table 4]

[0164]

[Table 5]

[0165]

[Table 6]

Comparative Example 1 Table 3 shows the control carboxyl group-containing vinyl polymer (A′-1) obtained in Reference Example 15, the component (C), the component (D) and the thinner. In the ratio as shown,
A resin composition for laminated coating for control having an NV of 46.5% was prepared by blending by a conventional method.

Thereafter, a cured coating film was prepared in the same manner as in Examples 1 to 8 and various properties and various performances were compared and examined. The results are shown together in the same table.

However, (2) in Table 3 is the data in the case of 2 coat 1 bake finishing, and (3) in Table 3
Is data for 2 coat 2 bake finish. Comparative Example 2 Reference hydroxyl group-containing vinyl polymer (Ref-1) obtained in Reference Example 16 and "Super Beckamine L-1.
17-60 "and thinner in a ratio as shown in Table 3 by a conventional method, and NV is 46.5%.
A control resin composition for laminated coating was prepared.

Thereafter, a cured coating film was prepared in the same manner as in Examples 1 to 8 and various characteristics and various performances were compared and examined. The results are shown together in the same table.

[0170]

[Table 7]

<< Footnote >>"L-117-60" ... "Super Betukamin L
-117-60 "

[0172]

[Table 8]

<< Footnote >> All "combinations" in the table are
Means "part".

[0174]

[Table 9]

Examples 9 to 14 Component (B), component (C), component (D) and thinner were mixed in a ratio as shown in Table 4 by a conventional method, and as shown in the same table. A resin composition for laminated coating having a specific NV was prepared.

Then, the performance of the coating films obtained by the two-coat one-bake finish or the two-coat two-bake finish, respectively, using the thus-obtained resin compositions for laminated coating as top coats, respectively. An evaluation was made.

The results are shown together in the same table.

Data on the storage stability of each resin composition for multi-layer coating are also shown in the same table. In addition,
(2) in Table 4 and a part of (4) in the table are data in the case of 2-coat 1-bake finish, while all (6) in the table and (8 in the table are the same. ) Part of 2 coat 2
This is the data for bake finishing.

Comparative Examples 3 and 4 The carboxyl group-containing intermediates (M-1) and (M-2) obtained in Reference Examples 7 and 8 respectively,
The component (C), the component (D) and the thinner are mixed in a ratio as shown in Table 4 by a conventional method to prepare a clear composition for control having NV as shown in the same table. did.

Thereafter, a cured coating film was prepared and various performances were evaluated in the same manner as in Examples 9 to 14. The results are shown together in the same table. In addition, data on the storage stability of each resin composition for multi-layer coating are also shown in the same table.

A part of (4) in Table 4 is the data in the case of 2 coat 1 bake finishing, while a part of (8) in the same table is the case of 2 coat 2 bake finishing. It is data.

[0182]

[Table 10]

<< Footnote >> All "combinations" in the table are
Means "part".

Compound (C-6): Sorbitol polyglycidyl ether having an epoxy equivalent of 170 (C-7): Epiclone 1050-7
0X ”[Bisphenol A diglycidyl ether type epoxy resin manufactured by Dainippon Ink and Chemicals, Inc .; xylene solution, NV = 70%, epoxy equivalent = 680] TMBAA …… abbreviation of trimethylbenzylammonium acetate Compound (D-4) ……………… Magnesium content is 2%
Naphthenate Magnesium

[0185]

[Table 11]

<< Footnote >> Storage stability: The clear composition is stored for 30 days at 40 ° C., and the viscosity is divided by the initial viscosity of the composition. Thinner property ………… Visually judge the appearance of the coating film after 30 times of rubbing xylene.

[0187]

[Table 12]

[0188]

[Table 13]

[0189]

[Table 14]

[0190]

[Table 15]

[0191]

[Table 16]

[0192]

[Table 17]

[0193]

As described above in detail, the resin composition for laminate coating used in the present invention has a form in which it is protected by a hemiacetal ester group and / or a hemiketal ester group as an active ingredient. , A vinyl polymer having a specific structure, or a resin containing a polyether resin, a polyester resin, a polyamide resin and / or a polyurethane resin, and thus having excellent storage stability as a one-pack paint. Therefore, of course, the workability is good, the coating film obtained by the coating finishing method of the present invention is also excellent in acid resistance, weather resistance and coating appearance, which is extremely useful. It is a thing.

Therefore, it can be said that the coating finishing method using the resin composition for laminated coating according to the present invention establishes a novel aspect of automobile coating.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B05D 7/24 X 8616-4D T 8616-4D

Claims (7)

[Claims] 1. A vinyl polymer (A) having at least two hemiacetal ester groups and / or hemiketal ester groups in one molecule, or at least two hemiacetal ester groups in one molecule and / or At least one resin (B) selected from the group consisting of a polyether resin, a polyester resin, a polyamide resin and a polyurethane resin having a hemiketal ester group.
And a compound (C) having at least two epoxy groups in one molecule, which is used to obtain a resin composition for laminate coating. 2. A vinyl polymer (A) having at least two hemiacetal ester groups and / or hemiketal ester groups in one molecule, or at least two hemiacetal ester groups and / or in one molecule. At least one resin (B) selected from the group consisting of a polyether resin, a polyester resin, a polyamide resin and a polyurethane resin having a hemiketal ester group.
And a resin composition for laminated coating obtained by mixing the compound (C) having at least two epoxy groups in one molecule with the curing catalyst (D). 3. The above-mentioned hemiacetal ester group or hemiketal ester group is represented by the general formula: [Wherein, X in the formula, which may be the same or different, is an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an aryl group, an alkanoyloxy group, an aryloxy group, an aralkyl group and a halogen. 1-10 carbon atoms, which may or may not be substituted with at least one atomic group selected from the group consisting of atoms.
Is represented by the following alkylene group. ] Or a general formula: [Wherein, X in the formula, which may be the same or different, is an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an aryl group, an alkanoyloxy group, an aryloxy group, an aralkyl group and a halogen. 1-10 carbon atoms, which may or may not be substituted with at least one atomic group selected from the group consisting of atoms.
And R1 is an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl group,
It represents an alkyl group having 1 to 18 carbon atoms, which may or may not be substituted with an aralkyl group or an alkoxyl group. ] Or a general formula: [Wherein R 2 and R 4 in the formula may be the same or different and each is a hydrogen atom or has 1 to 1 carbon atoms]
And R3 may be the same or different and each has 1 to 2 carbon atoms.
2 may or may not be substituted with at least one atomic group selected from the group consisting of an alkyl group, cycloalkyl group, aralkyl group, aryl group, alkoxyl group, alkanoyloxy group and halogen atom. , And represents an alkyl group having 1 to 22 carbon atoms. ] The coating method of Claim 1 or 2 which has a structure shown by these. 4. The above resin (B) is at least one selected from the group consisting of a polyether resin, a polyester resin, a polyamide resin and a polyurethane resin, each of which has at least two carboxyl groups in one molecule.
The coating method according to claim 1 or 2, which is synthesized by a reaction between a seed and an α, β-ethylenically unsaturated ether compound. 5. The coating method according to claim 1, wherein the compound (C) having at least two epoxy groups in one molecule is a vinyl polymer. 6. The coating method according to claim 1, wherein the laminated coating is a two-coat one-bake method. 7. The coating method according to claim 1, wherein the laminated coating is a two-coat two-bake method.