JP2003041185A - Resin composition for coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for coating use giving a coating film having excellent smoothness and finished appearance in a wet-on-wet coating of buildings, building materials, plastics, automobiles, etc. SOLUTION: The resin composition for coating is composed of a curing agent having a hydrazine residue acting as a one-pack cold-curing functional group and a block isocyanate group acting as a thermosetting functional group in one molecule and a resin containing >=2 keto groups or hydroxy groups acting as a functional group to crosslink with the curing functional group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating resin for overpainting, and more specifically, a coating resin for use in buildings, steel structures, building materials, plastics, automobiles and the like. Among them, it particularly relates to a resin for paint, which is suitable for a resin for automobile paint.

[0002]

2. Description of the Related Art Conventionally, in the formation of a thermosetting coating film, the coating film is extremely resistant to heat and external force after the coating process until the object is set and heated to complete the thermosetting reaction. Weak condition. That is, by vertical curing of the coating film on the vertical surface, sagging occurs due to a decrease in viscosity due to heating, the volatile composition in the coating film changes due to heating, or the solvent parameter of the coating film changes, Partial precipitation and re-dissolution of the non-volatile matter will occur, and the finished appearance of the coating film after thermosetting will deteriorate. Further, in the overcoating, there is a problem that the upper layer coating film and the lower layer coating film are mixed with each other, and the finish appearance of the coating film after thermosetting is deteriorated.

Further, conventionally, when a coating film having a multi-layered structure is formed on the surface of an automobile body, lower coating layers such as an undercoat coating layer and an intermediate coating layer are sequentially formed on the surface of the automobile body. After that, after applying a thermosetting resin coating compounded with a metallic pigment or a coloring pigment as the top coating base coating, the solid content of the top coating base coating is increased by preheating, and the thermosetting property is applied to the top by the wet-on-wet method. A so-called two-coat / one-bake method of overcoating is widely used in which a resin coating is applied as an overcoat clear coating, and then the entire coating film is thermally cured by baking (baking) by heating. In order to obtain a high finish appearance by this method, it is necessary to prevent the topcoat base coating layer and the topcoat clear coating layer from being mixed with each other after the topcoat clear coating material is applied.

However, in order to increase the amount of non-volatile components in the overcoat base and clear paint, the molecular weight of both paint resins must be lowered in order to increase the amount of non-volatile components in the topcoat base and the clear paint in consideration of the recent environment-friendly high solidification system. When it is used for coating, there is a problem that the topcoat clear coating film layer component is easily mixed with the topcoating base coating film layer, and as a result, the smoothness and finish appearance of the coating film are deteriorated due to metal reversion, dimples, and blurring.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin composition for coatings, which is superior in smoothness and finished appearance to conventional coating films, especially in overcoating.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, a curing agent in which a one-liquid room temperature curing functional group and a thermosetting functional group coexist in one molecule, In the wet-on-wet coating, a relatively low temperature condition, such as during preheating, can be obtained by using a composition of the curing functional group of (1) and a resin having a functional group that causes a crosslinking reaction in the intermediate coating and / or the top coating base coating. Even in a short time, it is possible to prevent mixing of solvents and the like from the overcoat base coating film or the overcoat clear coating film, and the finish appearance of the coating film after coating with the overcoat clear coating and heat curing The inventors have found that a coating film which is excellent in solvent resistance, water resistance, acid resistance, weather resistance, chemical resistance, heat resistance and smoothness is formed, and has reached the present invention. That is, the first aspect of the present invention is characterized by containing a curing agent (A) having a blocked isocyanate group and a hydrazine residue in one molecule and a compound (B) having two or more keto groups in one molecule. And a resin composition for paint.

In the second aspect of the invention, the compound (B) is 1
The resin composition for coating composition of the invention 1 is a compound (C) having one or more hydroxyl groups in the molecule. Furthermore, the third aspect of the invention is characterized by containing a compound (D) having two or more hydroxyl groups in one molecule.
2 is a resin composition for paint.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The curing agent (A) of the present invention is generally a compound having an isocyanate group, an isocyanate group blocking agent (hereinafter simply referred to as “blocking agent”), and a compound having a hydrazine and / or a hydrazine residue (hereinafter, If necessary, it is referred to as a "hydrazine compound")). Examples of the compound having an isocyanate group used for preparing the curing agent (A) of the present invention include diisocyanates and polyisocyanate compounds.

Examples of the above diisocyanates include:
Alkylene diisocyanates such as hexamethylene diisocyanate (HDI); Cycloalkylene diisocyanates such as 4,4′-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), isophorone diisocyanate (IPDI), dimethylcyclohexane diisocyanate (hydrogenated XDI); 2 , 4-Tolylene diisocyanate, 2,6-Tolylene diisocyanate and mixtures thereof (TDIs), diphenylmethane-4,4'-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3-dimethyl- 4,4-diphenylene diisocyanate (TODI), crude TDI
s, polymethylene polyphenyl diisocyanate, crude MDI, arylene diisocyanate such as phenylene diisocyanate, xylylene diisocyanate (XD
Examples thereof include aralkylene diisocyanate such as I) and the like, and combinations thereof.

Of these diisocyanates, preferred are those from the viewpoint of improving the curability and solvent resistance of a coating film obtained from a resin composition comprising a curing agent (A) described below and a compound having a keto group and a hydroxyl group. They are alkylene diisocyanate and cycloalkylene diisocyanate.

On the other hand, the above-mentioned polyisocyanate is obtained by oligomerizing diisocyanate by forming a biuret bond, a urea bond, an isocyanurate bond, a urethane bond, an allophanate bond, a uretdione bond and the like to provide a trimer to a 20mer. Is common. The diisocyanate that can be used for producing the polyisocyanate compound has a linear or branched carbon number of 2 to 20.
Alkylenediisocyanate, C5-C20 cycloalkylenediisocyanate which is unsubstituted or substituted with an alkyl group having 1-18 carbon atoms, an alkoxy group having 1-8 carbon atoms or an alkylene group having 1-6 carbon atoms An arylene diisocyanate having 6 to 20 carbon atoms, which is unsubstituted or substituted with an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, and unsubstituted or having 1 to 18 carbon atoms Is an at least one diisocyanate selected from the group consisting of C8 to C20 aralkylene diisocyanates substituted with C1 to C8 alkoxy groups.

In addition to the above method, the polyisocyanate may be prepared by a polymer containing only an isocyanate group-containing radically polymerizable monomer or a copolymer with another polymerizable radically polymerizable monomer. Good. The isocyanate group-containing radical-polymerizable monomer is a compound having at least one isocyanate group and at least one radical-polymerizable double bond in one molecule, and examples thereof include methacryloyl isocyanate, 2-isocyanatoethyl methacrylate and m-. Alternatively, p-isopropenyl-α, α′-dimethylbenzyl isocyanate and the like can be mentioned.

Examples of the blocking agent used for preparing the curing agent (A) of the present invention include phenols such as phenol, cresol, ethylphenol and butylphenol, butyl cellosolve, propylene glycol monomethyl ether, benzyl alcohol, methanol and ethanol. Alcohols such as 2-ethylhexanol; active methylenes such as dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate and acetylacetone; mercaptans such as butyl mercaptan, dodecyl mercaptan; acetanilide, acetic amide, ε-
Acid amides such as caprolactam, δ-valerolactam and γ-butyrolactam; acid imides such as succinimide and maleic imide;

Imidazoles such as imidazole and 2-methylimidazole, ureas such as urea, thiourea and ethylene urea; oximes such as formaldoxime, acetoaldoxime, acetone oxime, methylethylketoxime and cyclohexanone oxime; diphenylamine and aniline. , Amines such as carbazole; ethyleneimine,
There are imine type such as polyethyleneimine, and oxime type;
Acid amide type and active methylene type are preferable, and particularly acetone oxime, methyl ethyl ketoxime, ethyl acetoacetate, methyl acetoacetate, dimethyl malonate, diethyl malonate, and ε-caprolactam are preferable. These blocking agents may be used alone or in combination of two or more.

Examples of the hydrazine compound used for preparing the curing agent (A) of the present invention include hydrazine and hydrates thereof; ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-1. , 4-dihydrazine and other dihydrazine compounds; oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itadonic acid diphthalic acid, itaconic diphthalic acid, dihydric acid dihydrazide, itaconic acid diphthalic acid Dicarboxylic acid dihydrazides such as phthalic acid dihydrazide; Tricarboxylic acid trihydrazides such as trimellitic acid trihydrazide; Carbonic acid dihydrazides represented by the following formula (1);

[0016]

[Chemical 1]

(In the formula, X represents an integer of 0 or 1.) Bissemicarbazides represented by the following formula (2):

[0018]

[Chemical 2]

(In the formula, R ¹ is a linear or branched alkylene group having 2 to 20 carbon atoms, a cycloalkylene group having 5 to 20 carbon atoms, or not substituted or having 1 carbon atom.
Represents an arylene group having 6 to 10 carbon atoms, which is substituted with an alkyl group having 18 to 18 or an alkoxy group having 1 to 8 carbon atoms. ) And mixtures thereof.

In the present invention, as described above, a diisocyanate, a polyisocyanate compound which is an oligomer of at least one dimer of these diisocyanates, or a polymer of an isocyanate group-containing radically polymerizable monomer is used. Alternatively, a blocking agent, which is a compound having one functional group that reacts with an isocyanate group, and a compound having a hydrazine and / or a hydrazine residue are reacted with the copolymer, and a one-liquid room-temperature curing function is included in one molecule. A curing agent (A) of the present invention having a hydrazine residue as a group and a blocked isocyanate group as a thermosetting functional group is obtained.

More specifically, for example, the following two methods can be mentioned. In the first method, a blocking agent in an equimolar amount with a part of the isocyanate groups of the compound having an isocyanate group is reacted quantitatively with the isocyanate group, and then the residual isocyanate group is added in an excess of 1.5 to 20 times. The curing agent (A) of the present invention is obtained by reacting an equivalent amount of a hydrazine residue in a hydrazine compound having an equivalent amount of a hydrazine residue and removing the unreacted hydrazine compound.

In the second method, a hydrazine compound in an equimolar amount with a part of the isocyanate groups of the compound having an isocyanate group is quantitatively reacted with the isocyanate group, and then the remaining isocyanate group and the blocking agent are quantitatively analyzed. To obtain the curing agent (A) of the present invention. In the case of the second method, since a hydrazine compound having an equimolar amount to the amount of the isocyanate group to be reacted is charged, in the case of a hydrazine compound having two or more hydrazine residues, one molecule of the hydrazine compound is reacted with two or more isocyanate groups. However, the amount of the curing functional group possessed by the compound having an isocyanate group may decrease. In that case, the first method is preferred.

Another method is to use a radical polymerizable monomer containing an isocyanate group as a starting material. For example, the compound (i) obtained by reacting the isocyanate group of the isocyanate group-containing radically polymerizable monomer with the blocking agent in an equimolar amount in advance, and the isocyanate group of the isocyanate group-containing radically polymerizable monomer with 1.5 to 20
Compound (ii) obtained by reacting an equivalent amount of a hydrazine residue in a hydrazine compound having a double excess equivalent amount of the hydrazine residue, and then removing an unreacted hydrazine compound
Is prepared, and then the compound (i), (ii), and / or another radical-polymerizable monomer is polymerized at an arbitrary ratio to obtain the curing agent (A) of the present invention.

The isocyanate group blocking reaction can be carried out with or without the presence of a solvent. When using a solvent, it is necessary to use a solvent which is inert to the isocyanate group. After completion of the blocking reaction, it can be diluted with a solvent which is active with respect to isocyanate groups. In the blocking reaction, an organic metal salt of tin, zinc, lead, etc. and 3
You may use a primary amine etc. as a catalyst. The blocking reaction can be generally carried out at -20 to 150 ° C, preferably 0 to 100 ° C. If the temperature is too high, side reactions may occur. On the other hand, if the temperature is too low, the reaction rate becomes slow, which is disadvantageous. It is preferably blocked so as to be substantially free of isocyanate groups.
The molar ratio of the blocked isocyanate group to the hydrazine residue of the curing agent (A) is 3/7 in order to obtain good coating physical properties.
Is preferably 9/1, more preferably 1 /
It is 1 to 4/1. And it is preferable that there is no free isocyanate group in the curing agent (A).

In the present invention, a monoketone represented by the following formula (3) (for example, acetone) is used in place of the human azine compound for the purpose of preventing excessive polymerization of the compound having an isocyanate group due to the chain extension action of the hydrazine compound. , Methylethylketone, methylisobutylketone, cyclohexanone, etc.) or monoaldehyde (eg acetaldehyde), etc. to block one of the terminal hydrazine groups of all or part of the hydrazine compound, and use a hydrazone compound derivative You can also R ² R ³ C═O (3) (In the formula, R ² and R ³ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms, or 5 to 5 carbon atoms.
A cycloalkyl group having 20 carbon atoms, or an aryl group having 6 to 10 carbon atoms which is unsubstituted or substituted with an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, and if necessary, R ² and R ³ may together form a cyclic structure. )

When the terminal hydrazine capped compound is used for the hydrazine compound, at least one terminal hydrazine residue is capped to form a hydrazone residue, or a terminal hydrazine compound capped with the same. A mixture with unreacted hydrazine compound is obtained. That is,
The end cap of the curing agent of the present invention comprises at least one end group.
Exemplary ethynylphenylbiadamantane derivatives ^{R 2 R 3 C = N- (} R 2 and R ³ are as defined above) has a blocked terminal group represented by the. This terminal blocking agent is a monoaldehyde or monoketone of the terminal blocking group (R ² R ³ C =) derived from the monoaldehyde or monoketone used as the blocking agent due to the progress of hydrolysis in the preheating step at the time of coating described later. As a result of desorption,
A coating film with a high degree of crosslinking is formed. Especially, 30 ~ 200 ℃
Monoketone having a boiling point of is preferable as a blocking agent having good hydrolyzability.

To impart water solubility to the curing agent (A) of the present invention or to improve its water solubility, a compound having a hydrophilic group is reacted with a part of the isocyanate groups of diisocyanate or polyisocyanate. You can do that. The reaction of the compound having an isocyanate group with a hydrophilic group may be before, during or after reacting the isocyanate group with the blocking agent, or before reacting with the compound having an isocyanate group and hydrazine and / or hydrazine residue, during the reaction. , Any of the latter may be used. Examples of the compound having a hydrophilic group include a nonionic hydrophilic group, an ionic hydrophilic group, and an active hydrogen-containing compound having at least one group selected from the group consisting of groups capable of being converted into an ionic system. .

Examples of the compound having a nonionic hydrophilic group include polyethylene glycol monoalkyl ether, polyethylene glycol, polyoxyethylene-oxypropylene (random and / or block) glycol, polyoxyethylene-oxytetramethylene ( Polyether polyols such as random and / or block) glycols and the like. Of these, polyethylene glycol monoalkyl ether is preferably used because polyether or polyol tends to cause a chain extension reaction with diisocyanate or polyisocyanate to cause a high molecular weight.

The active hydrogen-containing compound having an ionic hydrophilic group is preferably a carboxylic acid or sulfonic acid which is an active hydrogen-containing compound having an anion group, or a salt thereof with an amine compound or an alkali metal salt thereof. Examples thereof include an onium salt, which is an active hydrogen-containing compound having a cation group, and the like.

Examples of the active hydrogen-containing compound having an anion group include those obtained by neutralizing an active hydrogen-containing compound having an acid group that can be converted into an anion group with a base. Examples of the active hydrogen-containing compound having an acid group that can be converted to an anion group include lactic acid, glycolic acid, 4-hydroxybutyric acid, p-phenolcarboxylic acid and other monohydroxycarboxylic acids; glycine, alanine, aspartic acid, Amino acids such as β-alanine; p
-Monohydroxy sulfonic acids such as phenol sulfonic acid; amino sulfonic acids such as taurine and the like, and combinations thereof, and α, α'-dimethylolpropionic acid, α,
Examples include α, α′-dimethylolalkanoic acid such as α′-dimethylolacetic acid. Of these, α, α′-dimethylolalkanoic acid tends to cause a chain extension reaction with diisocyanate or polyisocyanate to induce a high molecular weight, so that the above monohydroxycarboxylic acid,
Amino acids, monohydroxy sulfonic acids, amino sulfonic acids, or combinations thereof are preferred. Examples of the base that can be used to neutralize the acid group of the active hydrogen-containing compound having an acid group that can be converted into the above-mentioned anion group include, for example, triethylamine, ammonia, diethanolamine,
Amine compounds such as dimethylaminoethanol, methyldiethanolamine, dibutylamine; KOH, Na
Examples thereof include alkali metal hydroxides such as OH and LiOH; and combinations thereof.

Examples of the active hydrogen-containing compound having a cation group include those obtained by neutralizing an active hydrogen-containing compound having a base that can be converted into a cation group. For example, N-alkyldialkanolamines such as N-methyldiethanolamine and N-butyldiethanolamine, and their alkylene oxide (ethylene oxide, propylene oxide, etc.) adducts having 2 to 4 carbon atoms,
Examples thereof include N, N-dialkylmonoalkanolamines such as N, N-dimethylethanolamine and N, N-diethylethanolamine, and combinations thereof. Of these, especially N, N-dimethylethanolamine,
N, N-dialkylmonoalkanolamines such as N, N-diethylethanolamine are preferred. Acids that can be used to neutralize the base of these active hydrogen-containing compounds include, for example, acetic acid, lactic acid, hydrochloric acid, phosphoric acid, sulfuric acid and combinations thereof. Further, as the alkylating agent,
Examples thereof include dimethyl sulfate, diethyl sulfate, methyl chloride, methyl iodide, benzyl chloride and the like.

In addition to the above, other methods of imparting water solubility to the curing agent (A) or improving water solubility include:
For example, Japanese Patent Application No. 10-130387 discloses a method of reacting a hydrazine residue in a curing agent (A) with a ketone acid.

The composition of the present invention contains at least a curing agent (A) and a compound (B) having two or more keto groups in one molecule. Due to the presence of the compound (B), this composition, or a composition obtained by adding other components to this composition as the case requires, is used as a topcoat base coating in a coating step, after the topcoat base coating, a clear top coating. By forming a coating film having excellent solvent resistance by a crosslinking reaction that occurs between the keto group of the compound (B) and the hydrazine residue of the curing agent (A) during preheating performed before,
It is possible to suppress the mixing of the coating layer components with the top clear clear coating to be subsequently applied, and as a result of the baking step after top clear clear coating, it is possible to form a finished coating film excellent in smoothness and finish appearance. .

At this time, in the case where the hydrazine residue of the curing agent (A) is end-capped, the elimination by hydrolysis of the monoketone or monoaldehyde derived from the end-capping agent is caused by the removal of the compound (B) or (C). Before mixing, it may be carried out by hydrolysis and evaporation, or a resin composition for coating containing a curing agent (A) which is not subjected to hydrolysis is prepared, and a curing process by preheating after coating is carried out. May be spontaneously desorbed in. Examples of the compound (B) having two or more keto groups in one molecule of the present invention include keto group-containing polyurethane, keto group-containing polyvinyl alcohol, acetoacetylated polyvinyl alcohol, acetoacetylated hydroxyalkyl cellulose, keto group. Examples thereof include polymers of contained radically polymerizable monomers, and copolymers of radically polymerizable monomers copolymerizable with the monomers.

Among these, a polymer of a radically polymerizable monomer containing a keto group and a copolymer of a radically polymerizable monomer copolymerizable with the monomer are, for example, the following keto group. It is possible to polymerize the contained radically polymerizable monomer and other monomer by a usual method. Examples thereof include diacetone acrylamide, diacetone methacrylamide, acrolein, vinyl methyl ketone, acetoacetoxyethyl methacrylate, acetoacetoxyethyl acrylate, formyl styrene, and the like, and combinations thereof. The keto group-containing radically polymerizable monomer polymer and the copolymer of the monomer and the radically polymerizable monomer copolymerizable with the keto group have a keto group value of 20 to 150, preferably 30 to 150. 10
0, the acid value is 0 to 100, preferably 5 to 60.

Further, the compound (B) has 1 in its molecule.
It may be a compound (C) having one or more hydroxyl groups.
The blocking agent is thermally desorbed from the hydroxyl group of the compound (C) and the blocked isocyanate group of the curing agent (A) in the baking step after the above-mentioned topcoat base paint coating step, preheat, and topcoat clear coating step. A crosslinking reaction proceeds with the resulting isocyanate groups, and as a result, a good coating film is formed.

Examples of the compound (C) include a polyurethane containing a hydroxyl group and a keto group, a polyvinyl alcohol containing a keto group, an acetoacetylated polyvinyl alcohol, an acetoacetylated hydroxyalkyl cellulose, a radical polymerizable monomer containing a keto group. Examples thereof include polymers of hydroxyl group-containing radically polymerizable monomers, and copolymers of radically polymerizable monomers copolymerizable with the monomers. Among these, a copolymer of a keto group-containing radically polymerizable monomer and a hydroxyl group-containing radically polymerizable monomer, and a copolymer of a radically polymerizable monomer copolymerizable with the monomer are as described above. A keto group-containing radically polymerizable monomer used in the preparation of the compound (B), and a hydroxyl group-containing radically polymerizable monomer shown below,
Alternatively, it can be polymerized from other monomers by a usual method.

Examples of the hydroxyl group-containing radically polymerizable monomer include hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and N-methylol. (Meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N, N-dihydroxyethyl (meth) acrylamide and the like can be mentioned. Examples of other radically polymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and iso-butyl (meth) acrylate. , 3-benzyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-heptyl (meth) acrylate, octyl (meth) acrylate,
Alkyl ester of (meth) acrylic acid such as 2-octyl (meth) acrylate, nonyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and 2-ethylbutyl (meth) acrylate. A carboxyl group-containing monomer such as (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid;
Examples thereof include styrene, vinyltoluene and glycidyl methacrylate. Further, the copolymer of a keto group-containing radically polymerizable monomer and a hydroxyl group-containing radically polymerizable monomer, and the copolymer of a radically polymerizable monomer copolymerizable with the monomer, The keto group value is 20 to 150, preferably 30 to 100, and the hydroxyl value is 20 to 150, preferably 30.
˜100, acid value 0˜100, preferably 5˜60.

The composition containing the curing agent (A) and the compound (B) or (C) of the present invention may further contain a compound (D) having two or more hydroxyl groups in one molecule.
The compound (D) imparts thermosetting property in the baking step by being used in combination with the composition of the curing agent (A) and the compound (B) having two or more keto groups in one molecule. When used in combination with a curing agent (A) and a compound (C) having two or more hydroxyl groups and one or more keto groups in one molecule, the thermosetting property in the baking step can be improved. Can be further enhanced.

The compound (D) can be used without any particular limitation as long as it is usually used for coating. Acrylic polyols, polyester polyols, polyether polyols, aliphatic hydrocarbon polyols, epoxy resins, Fluorine polyol and the like are examples. Among them, acrylic polyols, polyester polyols, and fluorine polyols are preferable.

Among them, the acrylic polyols can be polymerized by a usual method from the hydroxyl group-containing radically polymerizable monomer used for preparing the above-mentioned compound (C) and other monomers. The acrylic polyols have a hydroxyl value of 20 to 150, preferably 30 to 1
00, the acid value is 0 to 100, preferably 5 to 70.

The polyester polyols include, for example, phthalic acid and its acid anhydride, isophthalic acid, terephthalic acid,
Trimellitic acid and its acid anhydride, hexahydrophthalic acid and its acid anhydride, succinic acid, adipic acid, pimelic acid, sebacic acid, polybasic acid components such as brassic acid and ethylene glycol, diethylene glycol, propylene glycol, Neopentyl glycol, 1,6
It can be produced by condensation polymerization of a polyol component such as -hexanediol, trimethylolpropane, glycerin, pentaerythritol and tricyclodecanedimethanol according to a conventional method. These polyester polyols have a hydroxyl value of 20 to 150, preferably 30 to 130, and an acid value of 50 or less,
5-30 are suitable.

Examples of the polyether polyols include polyether polyols obtained by adding polyhydric alcohols such as glycerin and propylene glycol, alone or in admixture, to alkylene oxides such as ethylene oxide and propylene oxide, in admixture. , Polytetramethylene glycols, ethylenediamine to alkylene oxide, polyetherpolyols obtained by reacting a polyfunctional compound such as ethanolamine, and obtained by polymerizing acrylamide or the like using these polyethers as a medium, So-called polymer polyols and the like are included.

Examples of the aliphatic hydrocarbon polyols include end-hydrogenated polybutadiene and hydrogenated products thereof. Examples of the epoxy resins include novolac type, β-methyl epichloro type, cyclic oxirane type, glycidyl ether type, glycol ether type, epoxy type of aliphatic unsaturated compound, epoxidized aliphatic ester type,
Examples thereof include polycarboxylic acid ester type, aminoglycidyl type, halogenated type and resorcin type epoxy resins.

Examples of the fluoropolyols include copolymers of fluoroolefin, cyclohexyl vinyl ether, vinyl monocarboxylic acid ester, etc. disclosed in JP-A-57-34107, JP-A-61-275311, and the like. To be The molar ratio of the latent isocyanate group and the hydroxyl group of the polyvalent hydroxyl compound in the composition containing the compound having a blocked isocyanate group is usually 0.5 to
Set to 2.5.

With respect to the resin composition for coatings using the composition of the present invention, the molar ratio of the hydrazine residue in the curing agent (A) to the keto group of the compound (B) or compound (C) is 1 /.
0.1 to 0.1 / 1, preferably 2/1 to 0.
It is 5/1. The molar ratio of the blocked isocyanate groups in the curing agent (A) to the total hydroxyl groups of the compound (C) and the compound (D) is 1 / 0.1 to 0.1 / 1, preferably 2 /. It is 1 to 0.5 / 1.

The composition of the present invention can be used in combination with other curing agents. Examples of the curing agent include melamine resins such as methylated melamine, methylolated melamine and butyrolated melamine, and urea resins such as methylated urea and butylated urea. For the composition of the present invention, the following raw materials commonly used in the technical field can be used. For example, quinacridone-based, azo-based, phthalocyanine-based organic pigments, titanium oxide, barium sulfate, calcium carbonate,
Inorganic pigments such as silica, other pigments such as carbon-based pigments, metal foil pigments, rust-preventive pigments, hindered amine-based, benzotriazole-based UV absorbers, hindered phenol-based, phosphorus-based, sulfur-based, etc. antioxidants Agents, urethanization (blocking agent dissociation) catalysts, leveling agents, rheology control agents, pigment dispersants, and other additives and solvents.

The composition of the present invention can be used by directly coating it on a substrate of an article to be coated such as a building, a steel structure, a building material, and a plastic. Further, it can be used as a base coating for automobiles, an intermediate coating for automobiles, a plastic coating, a coating for precoat metal, etc., or an electrodeposition coating by making the composition of the present invention hydrophilic. The coating method when the composition of the present invention is used as a base coating for automobiles is a pigment such as a pigment aluminum paste in the composition of the present invention, a dispersant,
A paint mixed with additives such as a rheology control agent is adjusted to a coating viscosity of about 15 to 30 seconds (Ford cup # 4, 20 ° C), and an air atomization type electrostatic coating machine and a rotary atomization type electrostatic coating machine are adjusted. And the like so as to have a dry film thickness of 10 to 60 μm. In the examples and comparative examples of the present invention, coating with a spray gun was performed for convenience.

Curing of a coating film using the composition of the present invention is 7
The hydrazine residue of the curing agent and the keto group of the compound having a keto group are subjected to dehydration condensation reaction at about 0 to 100 ° C. for about 5 to 15 minutes, and then at 120 to 180 ° C. for about 10 minutes.
In about 30 minutes, the isocyanate blocking agent of the curing agent is liberated, and the reaction is carried out by reacting the isocyanate with the hydroxyl group of the compound having a hydroxyl group. The present invention will be described based on Examples and Comparative Examples. "Parts" and "%" in Examples and Comparative Examples are by weight unless otherwise specified.

[0050]

[Reference Example 1] (Synthesis of a compound having a blocked isocyanate group and a hydrazine residue in one molecule (curing agent A))
A polyisocyanate compound using HMDI as a raw material in a four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser (trade name “Duranate 24A-10, manufactured by Asahi Kasei Co., Ltd.”
0 ", NCOwt%: 23.5%) 100 parts, t
After dissolving in 99 parts of -BuOH, 34 parts of methyl ethyl ketoxime was added in the range of 40 to 50 ° C over 1 hour with stirring. It was confirmed by gas chromatographic analysis that methyl ethyl ketoxime had disappeared, and a partially blocked polyisocyanate solution was obtained.

Next, 80% hydrazine monohydrate 35 was added to a 4-necked flask equipped with a stirrer, a thermometer, and a reflux condenser.
Part, propylene glycol monopropyl ether 191
Part, and a mixture of 44 parts of t-BuOH were added, and a total amount of 233 parts of the partially blocked polyisocyanate solution was added to 0-10.
In the range of 0 ° C, the mixture was added over 2 hours with stirring. Then, it stirred at room temperature for 1 hour, and obtained the reaction liquid. Next, in order to remove water, hydrazine and t-BuOH in the reaction solution,
Distillation under reduced pressure gave a compound having a blocked isocyanate group and a hydrazine residue.

[0052]

[Reference Example 2] (Synthesis of compound having a blocked isocyanate group and a hydrazine residue in one molecule (curing agent A))
A polyisocyanate compound using HMDI as a raw material in a four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser (trade name “Duranate 24A-10, manufactured by Asahi Kasei Co., Ltd.”
0 ", NCO wt%: 23.5%) 100 parts, ethyl acetoacetate 49 parts, acetylacetone zinc monohydrate 0.1
Then, the solution was dissolved in 99 parts of t-BuOH. Then 90
The temperature was raised to ° C, the reaction was carried out for 12 hours, and it was confirmed by gas chromatography analysis that ethyl acetoacetate had disappeared, and a partially blocked polyisocyanate solution was obtained.

Next, 80% hydrazine monohydrate 35 was added to a 4-necked flask equipped with a stirrer, a thermometer, and a reflux condenser.
Part, propylene glycol monopropyl ether 191
Part, and a mixture of 44 parts of t-BuOH were added, and a total amount of 249.1 parts of the partially blocked polyisocyanate solution was added to 0 part.
In the range of 10 ° C, the mixture was added over 2 hours with stirring.
Then, it stirred at room temperature for 1 hour, and obtained the reaction liquid. Next, in order to remove water, hydrazine and t-BuOH in the reaction solution, vacuum distillation was performed to obtain a compound having a blocked isocyanate group and a hydrazine residue.

[0054]

[Reference Example 3] (Synthesis of compound having a blocked isocyanate group and a hydrazine residue in one molecule (curing agent A))
100 parts of 2-isocyanatoethyl methacrylate (trade name "Karenzu MOI" of Showa Denko KK), 88 parts of ethyl acetoacetate, and 1 water of acetylacetone zinc in a four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser. Japanese food 0.
1 part was added and dissolved in 50 parts of t-BuOH. Then 9
The temperature was raised to 0 ° C. and the reaction was performed for 12 hours. After confirming that the absorption of the isocyanate group disappeared by the infrared spectrum, t-BuOH was distilled off under reduced pressure to obtain a blocked isocyanate monomer.

40 parts of 80% hydrazine monohydrate, 218 parts of propylene glycol monopropyl ether, t in a four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser.
A mixture of 50 parts of -BuOH was added, and 33 parts of 2-isocyanatoethyl methacrylate was dissolved in 67 parts of t-BuOH, and the total amount of the solution was added in the range of 0 to 10 ° C over 2 hours with stirring. Then, it stirred at room temperature for 1 hour, and obtained the reaction liquid. Next, water, hydrazine and t-Bu in the reaction solution
Distillation under reduced pressure was performed to remove OH and propylene glycol monopropyl ether to obtain a hydrazine residue-containing monomer.

229 parts of n-butyl cellosolve was placed in a four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser, and heated to 90 ° C. In addition, 120 parts of blocked isocyanate monomer, 110 parts of methyl methacrylate, 95 parts of butyl acrylate, 63 parts of 50% 2-dimethylaminoethanol / n-butyl cellosolve solution were added to 25 parts of acrylic acid.
A mixture of 88 parts of a neutralized acrylic acid salt solution, 39 parts of a semicarbazide group-containing monomer, and 4 parts of 2,2-azobisisobutyronitrile was added dropwise over 3 hours. After the dropping, 0.3 part of azobisisobutyrylonitrile was added and post-polymerization was carried out at 90 ° C. for 1 hour to obtain an acrylic resin solution having a blocked isocyanate group and a hydrazine residue (solid content: 5
6.6%).

[0057]

Reference Example 4 (Synthesis of Compound (C) Having Two or More Keto Groups and One or More Hydroxyl Groups in One Molecule) A 4-neck flask equipped with a stirrer, a thermometer, and a reflux condenser was used. -Butyl cellosolve was added in 260 parts and heated to 90 ° C. 137 parts of methyl methacrylate, 1 butyl acrylate
A mixture of 63 parts, 55 parts of 2-hydroxyethyl methacrylate, 36 parts of diacetone acrylamide, and 4 parts of 2,2-azobisisobutyronitrile was added dropwise over 3 hours. After the dropping, 0.3 part of azobisisobutyrylonitrile was added and post-polymerization was carried out at 90 ° C. for 1 hour to obtain an acrylic resin solution having a keto group and a hydroxyl group (solid content 59.2%).

[0058]

[Reference Example 5] (Synthesis of compound (C) having two or more keto groups and one or more hydroxyl groups in one molecule) Ion in a four-necked flask equipped with a stirrer, thermometer, reflux condenser 257 parts of exchanged water and 2.4 parts of a 38% aqueous solution of allyl sulfosuccinate (trade name: Eleminol JS-2, manufactured by Sanyo Kasei Co., Ltd.) were added, and the temperature in the flask was raised to 80 ° C. Five minutes after adding 7 parts of a 2% ammonium persulfate aqueous solution thereto, 151 parts of methyl methacrylate, 186 parts of butyl acrylate, 63 parts of 2-hydroxyethyl methacrylate, 8 parts of acrylic acid, 41 parts of diacetone acrylamide, 235 parts of ion-exchanged water, polyoxyethylene nonylphenyl ether (trade name: Emulgen 920,
5 parts of 25% aqueous solution of Kao Corporation, 38% of JS-2
An emulsion mixture of 3 parts of the aqueous solution and 1 part of ammonium persulfate was dropped into the flask over 3 hours. The temperature in the flask was kept at 80 ° C. during the dropping. After the dropping was completed, the temperature in the flask was set to 80 ° C. and kept for 2 hours. After that, 30 parts of ion-exchanged water was added and cooled to room temperature, 59 parts of 25% diethylaminoethanol aqueous solution was added, and the mixture was filtered through a wire mesh of 200 mesh to obtain a solid content of 44.3%, a keto group having an average particle size of 110 nm, and a hydroxyl group. An aqueous copolymer emulsion having

[0059]

[Reference Example 6] (Synthesis of compound having blocked isocyanate group) 4 equipped with stirrer, thermometer, reflux condenser
Polyisocyanate compound using HMDI as a raw material in a two-necked flask (trade name "Duranate 24A" of Asahi Kasei Corporation)
-100 ", NCO wt%: 23.5%) 100 parts, and dissolved in 99 parts ethyl acetate, 51 parts methyl ethyl ketoxime was added in the range of 40 to 50 ° C over 1 hour with stirring. It was confirmed by infrared spectrum that the absorption of isocyanate groups had disappeared, and a blocked polyisocyanate solution (solid content: 59.5%) was obtained.

[0060]

[Reference Example 7] (Synthesis of compound having blocked isocyanate group) 4 equipped with stirrer, thermometer, reflux condenser
Polyisocyanate compound using HMDI as a raw material in a two-necked flask (trade name "Duranate 24A" of Asahi Kasei Corporation)
-100 ", NCO wt%: 23.5%) 100 parts, ethyl acetoacetate 76 parts, and acetylacetone zinc monohydrate 0.2 parts were added and dissolved in ethyl acetate 99 parts. Then, the temperature was raised to 90 ° C. and the reaction was performed for 12 hours. It was confirmed by infrared spectrum that the absorption of isocyanate groups had disappeared, and a blocked polyisocyanate solution (solid content: 62.8%) was obtained.

[0061]

[Reference Example 8] (Synthesis of compound having blocked isocyanate group) 4 equipped with stirrer, thermometer, reflux condenser
2-isocyanatoethyl methacrylate (trade name "Karenzu MOI" of Showa Denko KK) 100 in a two-necked flask.
Parts, 88 parts of ethyl acetoacetate, zinc acetylacetone 1
0.1 part of hydrate was added and dissolved in 50 parts of t-BuOH. Then, the temperature was raised to 90 ° C. and the reaction was performed for 12 hours. After confirming that the absorption of the isocyanate group disappeared by the infrared spectrum, t-BuOH was distilled off under reduced pressure to obtain a blocked isocyanate monomer.

260 parts of n-butyl cellosolve was placed in a four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser, and heated to 90 ° C. A mixture of 120 parts of blocked isocyanate monomer, 141 parts of methyl methacrylate, 103 parts of butyl acrylate, 25 parts of acrylic acid and 4 parts of 2,2-azobisisobutyronitrile was added dropwise over 3 hours. After the dropping, 0.3 part of azobisisobutyrylonitrile was added and post-polymerization was carried out at 90 ° C. for 1 hour to obtain an acrylic resin solution having a blocked isocyanate group (solid content: 59.2).
%) Was obtained.

[0063]

Reference Example 9 (Synthesis of Compound (D) Having Two or More Hydroxyl Groups in One Molecule) A 4-necked flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 260 n-butyl cellosolve.
A portion was added and heated to 90 ° C. 167 parts of methyl methacrylate, 168 parts of butyl acrylate, 2 parts of methacrylic acid
A mixture of 55 parts of hydroxyethyl and 4 parts of 2,2-azobisisobutyronitrile was added dropwise over 3 hours. After dropping, 0.3 part of azobisisobutyronitrile was added, and post-polymerization was carried out at 90 ° C. for 1 hour to obtain an acrylic resin solution having a hydroxyl group (solid content 59.2%).

[0064]

Reference Example 10 (Synthesis of Compound (D) Having Two or More Hydroxyl Groups in One Molecule) Ion-exchanged water (257 parts) and allylsulfosuccinic acid were added to a four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser. Salt (Product name: Eleminor JS-2,
Inject 2.4 parts of 38% aqueous solution of Sanyo Kasei Co.,
The temperature in the flask was raised to 80 ° C. Five minutes after adding 7 parts of 2% ammonium persulfate aqueous solution thereto, 186 parts of methyl methacrylate, 193 parts of butyl acrylate,
63 parts of 2-hydroxyethyl methacrylate, 8 parts of acrylic acid, 235 parts of ion-exchanged water, 5 parts of 25% aqueous solution of polyoxyethylene nonylphenyl ether (trade name: Emulgen 920, manufactured by Kao Corporation), JS-2 An emulsion mixture of 3 parts of 38% aqueous solution and 1 part of ammonium persulfate was dropped into the flask over 3 hours. The temperature in the flask was kept at 80 ° C. during the dropping. After the dropping was completed, the temperature in the flask was set to 80 ° C. and kept for 2 hours. Then deionized water 30
Parts, and cooled to room temperature, added with 25 parts of 25% diethylaminoethanol aqueous solution and filtered through a wire mesh of 200 mesh to obtain a copolymer aqueous emulsion having a hydroxyl group with a solid content of 44.3% and an average particle size of 110 nm. It was

[0065]

Example 1 In 100 parts of an acrylic resin solution having a keto group and a hydroxyl group synthesized in Reference Example 4, 24 parts of a compound having the isocyanate block synthesized in Reference Example 1 and a hydrazine residue, and 0.27 of dibutyltin dilaurate were prepared. Department,
Pigment aluminum paste (Asahi Kasei Co., Ltd., trade name MH-8)
801) 19 parts was gradually added with stirring. After thoroughly stirring this with a lab disper, add ethyl acetate little by little while stirring to make the viscosity of the Ford Cup #
4 was adjusted to 20 seconds. This metallic paint was applied to a commercially available water-polished test plate coated with a cationic electrodeposition paint and a polyester resin-based intermediate coating paint.
Spray gun paint to a thickness of 20μm, 80 ℃
At 10 minutes, a dry film was formed using a heat dryer. After removing this coated plate from the dryer and cooling it to room temperature, 10 to 20 urethane two-component paint (trade name: Retan PG2K Clear A Base, manufactured by Kansai Paint Co., Ltd.) was used as a clear paint.
A spray gun was applied to a thickness of μm. After setting for 5 minutes, the coated plate was baked at 140 ° C. for 30 minutes with a heat dryer. The evaluation results of this coating film are shown in Table 1. In addition, the evaluation result "solvent resistance test after preheating"
Is the evaluation result of the coating film not coated with the urethane two-component paint.

[0066]

Example 2 In 100 parts of the acrylic resin solution having the keto group and hydroxyl group synthesized in Reference Example 4, 23 parts of the compound having the isocyanate block synthesized in Reference Example 2 and a hydrazine residue, and 0.23 of dibutyltin dilaurate were used. Department,
Pigment aluminum paste (Asahi Kasei Co., Ltd., trade name MH-8)
801) 19 parts was gradually added with stirring. After thoroughly stirring this with a lab disper, add ethyl acetate little by little while stirring to make the viscosity of the Ford Cup #
4 was adjusted to 20 seconds. This metallic paint was applied to a commercially available water-polished test plate coated with a cationic electrodeposition paint and a polyester resin-based intermediate coating paint.
Spray gun paint to a thickness of 20μm, 80 ℃
At 10 minutes, a dry film was formed using a heat dryer. After removing this coated plate from the dryer and cooling it to room temperature, 10 to 20 urethane two-component paint (trade name: Retan PG2K Clear A Base, manufactured by Kansai Paint Co., Ltd.) was used as a clear paint.
A spray gun was applied to a thickness of μm. After setting for 5 minutes, the coated plate was baked at 140 ° C. for 30 minutes with a heat dryer. The evaluation results of this coating film are shown in Table 1. In addition, the evaluation result "solvent resistance test after preheating"
Is the evaluation result of the coating film not coated with the urethane two-component paint.

[0067]

Example 3 100 parts of the aqueous emulsion having a keto group and a hydroxyl group synthesized in Reference Example 5, 78 parts of an acrylic resin solution having the isocyanate block synthesized in Reference Example 3 and a hydrazine residue, and dibutyltin dilaurate of 0. 20 parts of pigment aluminum paste (manufactured by Asahi Kasei Corp., trade name MH-8801) was gradually added with stirring. After thoroughly stirring this with a lab disper, 176 parts of distilled water was gradually added with stirring to obtain a solid content of 25.
A 0% aqueous acrylic resin paint was obtained. To this paint, a polyacrylic acid (trade name: Primal ASE-60, manufactured by Nippon Acrylic Chemical Co., Ltd.), which is an emulsion type thickener, is used.
Dimethylaminoethanol neutralized 2% aqueous solution (prepared by adding 10 parts of Primal ASE-60 to 130 parts of 0.88% aqueous solution of 2-dimethylaminoethanol little by little with stirring) to give a paint viscosity of Ford Cup # 4
It was adjusted to be 20 seconds. This metallic paint was applied to a commercially available water-polished test plate coated with a cationic electrodeposition paint and a polyester resin-based intermediate coating paint, respectively, and 10-2
A spray gun coating was applied to a thickness of 0 μm, and a dry film was formed by a heating dryer at 80 ° C. for 10 minutes. After removing this coated plate from the dryer and cooling it to room temperature, 10 to 20 μ of urethane two-component paint (trade name: Retan PG2K Clear A Base, manufactured by Kansai Paint Co., Ltd.) was used as a clear paint.
Spray gun coating was applied to achieve m thickness. After setting for 5 minutes, the coated plate was baked at 140 ° C. for 30 minutes with a heat dryer. The evaluation results of this coating film are shown in Table 1. The "solvent resistance test after preheating" of the evaluation result is the evaluation result of the coating film not coated with the urethane two-component paint.

[0068]

Comparative Example 1 100 parts of the hydroxyl group-containing acrylic resin solution synthesized in Reference Example 9, 28 parts of the isocyanate block solution synthesized in Reference Example 6, 0.27 parts of dibutyltin dilaurate, and pigment aluminum paste (Asahi Kasei Co., Ltd.) (Trade name: MH-8801, manufactured by Trademark Co., Ltd.) was gradually added with stirring. After thoroughly stirring this with a lab disper, ethyl acetate was added little by little with stirring to adjust the paint viscosity to 20 seconds with a Ford cup # 4. This metallic paint was spray-painted on a commercially available water-polished test plate coated with a cationic electrodeposition paint and a polyester resin-based intermediate coating paint to a thickness of 10 to 20 μm, and dried by heating at 80 ° C. for 10 minutes. Dry film was formed in a container. After removing this coated plate from the dryer and cooling it to room temperature, a urethane two-component paint as a clear paint (trade name: Retan PG2K clear A base, Kansai Paint Co., Ltd.)
Was manufactured by spray gun coating so as to have a thickness of 10 to 20 μm. After setting for 5 minutes, apply this painted plate to 140
It was baked in a heat dryer at 30 ° C. for 30 minutes. The evaluation results of this coating film are shown in Table 1. The "solvent resistance test after preheating" of the evaluation result is the evaluation result of the coating film not coated with the urethane two-component paint.

[0069]

Comparative Example 2 In 100 parts of the hydroxyl group-containing acrylic resin solution prepared in Reference Example 9, 31 parts of the compound having an isocyanate block prepared in Reference Example 7, 0.27 part of dibutyltin dilaurate, and a pigment aluminum paste (Asahi Kasei Co., Ltd., trade name MH-8801) 18 parts was gradually added with stirring. After thoroughly stirring this with a lab disper, ethyl acetate was added little by little with stirring to adjust the paint viscosity to 20 seconds with a Ford cup # 4. This metallic paint was spray-painted on a commercially available water-polished test plate coated with a cationic electrodeposition paint and a polyester resin-based intermediate coating paint to a thickness of 10 to 20 μm, and dried by heating at 80 ° C. for 10 minutes. Dry film was formed in a container. After taking this coated plate out of the dryer and cooling it to room temperature, spray gun of urethane 2-liquid paint (trade name: Retan PG2K clear A base, Kansai Paint Co., Ltd.) as a clear paint to a thickness of 10 to 20 μm. Painted. After setting for 5 minutes, the coated plate was baked at 140 ° C. for 30 minutes with a heat dryer.
The evaluation results of this coating film are shown in Table 1. The "solvent resistance test after preheating" of the evaluation result is the evaluation result of the coating film not coated with the urethane two-component paint.

[0070]

Comparative Example 3 100 parts of the hydroxyl group-containing aqueous emulsion synthesized in Reference Example 10 was added with 75 parts of the acrylic resin solution having an isocyanate block synthesized in Reference Example 8, 0.20 part of dibutyltin dilaurate, and a pigment aluminum paste (Asahi Kasei Co., Ltd., trade name MH-8801) 20 parts was gradually added with stirring. After thoroughly stirring this with a lab disper, in order to neutralize the acrylic acid in the acrylic resin solution, 176 parts of a 2% aqueous solution of 2-dimethylaminoethanol was gradually added with stirring to obtain a solid content of 2
A 5.2% aqueous acrylic resin paint was obtained. A 2% neutralized 2-dimethylaminoethanol aqueous solution of polyacrylic acid (trade name: Primal ASE-60, manufactured by Nippon Acrylic Chemical Co., Ltd.), which is an emulsion-type thickener, is added to this paint. 10 parts of Primal ASE-60 was added little by little to 130 parts of 88% aqueous solution with stirring) to adjust the viscosity of the paint to 20 seconds with a Ford cup # 4. This metallic paint is applied to a commercially available water-polished test plate coated with a cationic electrodeposition paint and a polyester resin-based intermediate coating paint, respectively.
Spray gun paint to a thickness of ~ 20μm and apply 80
A dry film was formed in a heating dryer at 10 ° C. for 10 minutes. After removing this coated plate from the dryer and cooling it to room temperature, it is a two-component urethane paint (trade name: Retan PG2K) as a clear paint.
Clear A base, made by Kansai Paint Co., Ltd. 10-2
A spray gun was applied to a thickness of 0 μm. After setting for 5 minutes, the coated plate was baked at 140 ° C. for 30 minutes with a heat dryer. The evaluation results of this coating film are shown in Table 1.
Shown in. The "solvent resistance test after preheating" of the evaluation result is the evaluation result of the coating film not coated with the urethane two-component paint.

[0071]

[Evaluation method] Smoothness: Visual evaluation ○ ・ ・ ・ ・ ・ Smoothness is good △ ・ ・ ・ ・ ・ Smoothness is slightly poor × ・ ・ ・ ・ ・ Smoothness is poor (textures and pinholes) Solvent resistance: Xylene Rub the coated surface 50 times with the included cotton swab and visually evaluate the condition.

◯: No melting, scratches or swelling of the coated surface. △: Melting, scratches and swelling on the coated surface are slightly observed. X: Melting, scratches and swelling of the coated surface are observed. Interlayer adhesion: Cuts reaching the bare ground are made in a grid pattern with a cutter knife, an adhesive tape is placed on the grid pattern, and the state of adhesion of the coating film after rapid peeling is visually observed. The cross-shaped cuts are made by drawing parallel lines of 11 vertical grooves that are orthogonal to the center of the test piece at intervals of 1 mm so that 100 squares are formed in one square centimeter.

◯: There is no peeling of the coating film. Δ: A small amount of peeling is observed between the metallic coating and the clear coating. X: Many delaminations are observed. Image clarity: Measured with an image clarity measuring device (manufactured by Suga Test Instruments Co., Ltd.). The numbers in the table are ICM values in the range of 0 to 100%, and the larger the number, the better the image clarity (image clarity).
If the M value is 80 or more, it means that the image clarity is extremely excellent. The compositions of Examples 1-3 and Comparative Examples 1-3 are shown in Table 2.

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

EFFECT OF THE INVENTION In wet-on-wet coating in which a topcoat base paint containing the coating resin composition of the present invention is applied and preheated, and then a topcoat clear paint is applied, even in a state where the temperature is relatively low during preheating. Overcoat base paint will cure in a time, and it is possible to prevent mixing of solvents etc. from the clear topcoat,
A coating film obtained by applying a clear top coating composition and then thermally curing it by baking forms a coating film having excellent finished appearance (visibility), solvent resistance, interlayer adhesion, and smoothness. Therefore, it is particularly useful as a paint when performing overcoating, and exhibits excellent performance as a paint resin for applications such as buildings, steel structures, building materials, plastics, automobiles, etc., especially as a resin for automobile paints. .

Continued front page    F-term (reference) 4J038 BA052 CE022 DG051 DG101                       DG121 DG131 DG161 DG201                       DG271 DG291 DG301 GA03                       JB19 KA03 NA01 NA03 NA04                       NA14 PA07 PA19 PB05 PB07                       PC08

Claims (3)

[Claims] 1. A curing agent (A) having a blocked isocyanate group and a hydrazine residue in one molecule and 2 in one molecule.
A resin composition for coating material, which comprises a compound (B) having one or more keto groups. 2. The resin composition for coating according to claim 1, wherein the compound (B) is a compound (C) having one or more hydroxyl groups in one molecule. 3. The resin composition for coating composition according to claim 1, which contains a compound (D) having two or more hydroxyl groups in one molecule.