JP2015101606A - Coating composition and coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition for forming a coating film having excellent chipping resistance, adhesiveness, finishing property and gasohol resistance without using a primer.SOLUTION: There is provided a coating composition which comprises a block copolymer (I), a hydroxyl group-containing urethane resin (II), a polyolefin-based resin (III), a curing agent (IV) and a conductive pigment (V). The block copolymer (I) comprises: a polymer block (A) containing a polymerizable unsaturated monomer (a1) having an epoxy group and the other polymerizable monomer (a2) so that the mass ratio is 5/95 to 100/0; and a polymer block (B) containing a polymerizable saturated monomer (a3) having at least one functional group selected from a hydroxyl group. a carboxyl group and an amino group and the other polymerizable unsaturated monomer (a4) so that the mass ratio is 3/97 to 50/50 and the block polymer has a weight average molecular weight of 2000 to 500000.

Description

  The present invention relates to a coating composition and a coated article capable of forming a coating film having excellent chipping resistance, adhesion, finish, and gasohol property for both a metal member and a plastic member.

  Generally, an automobile body has a metal member that forms the body and a plastic member such as a bumper.

  In such car body painting, conventionally, a metal member and a plastic member, separate paints suitable for the respective members, and a separate painting process are applied, and then the plastic member is attached to the metal member. ing.

  However, in recent years, in order to reduce the equipment cost in the manufacturing process of the automobile body and to match the color tone of the metal member and the plastic member, there is a demand for a method of painting with the plastic member mounted on the metal member.

  For example, Patent Document 1 discloses a method for painting an automobile body in which a polypropylene resin member is assembled to a metal steel plate.

  However, since the intermediate coating material disclosed in Patent Document 1 is not conductive, a conductive primer coating must be applied to the polypropylene member. That is, in Patent Document 1, conductive primer paint → intermediate paint → top coat paint is applied in order to the polypropylene member, and intermediate coat → top coat paint is applied in order to the metal member. That is, since the plastic member and the metal member are not all coated with the same paint and the same coating process, it is not sufficient in terms of cost reduction and color matching.

  In Patent Document 2, an electrodeposition-coated metal member and a plastic member are assembled and integrated, and a specific paint (conductive primer paint) → intermediate paint → top coat paint is applied to the surfaces of both members in order. A forming method is disclosed. However, this coating method is also a process that requires a conductive primer coating, and is not sufficient for cost reduction.

JP 2012-213692 A JP-A-1-288372

  The present invention has been made in consideration of these points, and a coating film having excellent chipping resistance, adhesion, finish, and gasohol property for metal members and plastic members without using a primer coating. It aims at providing the coating composition which can form, and a coated article.

  As a result of intensive studies to achieve the above object, the present inventors have developed a coating composition containing a specific block copolymer, a hydroxyl group-containing urethane resin, a polyolefin resin, a curing agent, and a conductive pigment. By using it, it discovered that the said subject could be solved and came to complete this invention.

That is, the present invention provides the following coating composition and an article obtained by coating the coating composition.
1.
A coating composition containing a block copolymer (I), a hydroxyl group-containing urethane resin (II), a polyolefin resin (III), a curing agent (IV), and a conductive pigment (V),
The block copolymer (I) contains a polymerizable unsaturated monomer (a1) containing an epoxy group and another polymerizable unsaturated monomer (a2) in a mass ratio of 5/95 to 100/0. A polymer block (A), a polymerizable unsaturated monomer (a3) containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group, and another polymerizable unsaturated monomer (a4). It is a block copolymer having a weight average molecular weight of 2,000 to 500,000, including a polymer block (B) contained so as to have a mass ratio of 3/97 to 50/50. Paint composition.

  According to the coating composition of the present invention, a coating film having excellent chipping resistance, adhesion, finish, and gasohol property is formed on both a metal member and a plastic member without using a primer. It becomes possible.

  Hereinafter, the coating composition of the present invention will be described in more detail.

  The coating composition of the present invention contains a specific block copolymer (I), a hydroxyl group-containing urethane resin (II), a polyolefin resin (III), a curing agent (IV), and a conductive pigment (V). It is.

Block copolymer (I)
In the present invention, the block copolymer (I) has an epoxy group-containing polymerizable unsaturated monomer (a1) and other polymerizable unsaturated monomer (a2) in a mass ratio of 5/95 to 100/0. A polymer block (A) containing the polymerizable unsaturated monomer (a3) containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group, and another polymerizable unsaturated monomer (a4). And a polymer block (B) containing 3/97 to 50/50 by mass ratio.

  The polymer block (A) is composed of a polymerizable unsaturated monomer (a1) containing an epoxy group and another polymerizable unsaturated monomer (a2) in a mass ratio of 5/95 to 100/0, preferably 8 / It contains so that it may become 92-80 / 20. If the polymerizable unsaturated monomer (a1) containing an epoxy group is less than this range, the resistance to hot water adhesion may be lowered.

  The polymerizable unsaturated monomer (a1) containing an epoxy group contains one or more epoxy groups selected from a glycidyl group, a 3,4-epoxycyclohexyl group, and a 2,3-epoxy-2-methylpropyl group. Examples include: glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, allyl glycidyl ether, 2,3-epoxy-2-methylpropyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meta ) Acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and the like.

  The other polymerizable unsaturated monomer (a2) is a monomer that can be copolymerized with the monomer (a1) other than the polymerizable unsaturated monomer (a1) containing an epoxy group. For example, methyl (meth) acrylate, ethyl ( (Meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) Acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl acrylate (trade name, Osaka) Organic Chemistry), cyclohex Alkyl or cycloalkyl (meth) acrylate such as (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, tricyclodecanyl (meth) acrylate; isobornyl (meth) ) A polymerizable unsaturated monomer having an isobornyl group such as acrylate; a polymerizable unsaturated monomer having an adamantyl group such as adamantyl (meth) acrylate; a tricyclodecenyl group such as tricyclodecenyl (meth) acrylate Polymerizable unsaturated monomer; aromatic ring-containing polymerizable unsaturated monomer such as benzyl (meth) acrylate, styrene, α-methylstyrene, vinyltoluene; vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltrie Toxisilane, vinylmethyldiethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltriisopropoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- ( (Meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane, γ- (meth) acryloyloxypropyltri-n-propoxysilane, γ- (meth) acryloyloxypropyltriisopropoxysilane, Polymerizable unsaturated monomers having hydrolyzable silyl groups such as vinyltriacetoxysilane and β- (meth) acryloyloxyethyltrimethoxysilane; perfluorobutylethyl (meth) acrylate, Perfluoroalkyl (meth) acrylates such as fluorooctylethyl (meth) acrylate; polymerizable unsaturated monomers having fluorinated alkyl groups such as fluoroolefins; N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate, acetic acid Vinyl compounds such as vinyl; hydroxyl group-containing polymerizability such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and allyl alcohol Unsaturated monomer; 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, 2-methacryloyloxy Phosphoric acid group-containing polymerizable unsaturated monomers such as cyclopropyl acid phosphate; N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylamide, methylenebis Nitrogen-containing polymerizable unsaturated monomers such as (meth) acrylamide, ethylenebis (meth) acrylamide, 2- (methacryloyloxy) ethyltrimethylammonium chloride, adducts of glycidyl (meth) acrylate and amines; 2-acrylamide-2 -Methylpropanesulfonic acid, 2-sulfoethyl (meth) acrylate, allylsulfonic acid, 4-styrenesulfonic acid and the like; polymerizable unsaturated monomers having a sulfonic acid group such as sodium salt and ammonium salt of these sulfonic acids; Carboxylic group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate; polymerizable unsaturated monomers having acid anhydride groups such as maleic anhydride, itaconic anhydride and citraconic anhydride A monomer etc. are mentioned, These can be used individually or in combination of 2 or more types.

  Another polymerizable unsaturated monomer (a2) is a (meth) acrylic acid having a hydrocarbon group having 8 or more carbon atoms as a part of the component from the viewpoint of improving the compatibility of the paint blending component and the stability of the paint. It is desirable to include an ester. Examples of the (meth) acrylic acid ester having a hydrocarbon group having 8 or more carbon atoms include 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, stearyl (meth) acrylate, isostearyl acrylate ( Trade name, manufactured by Osaka Organic Chemical Co., Ltd.), lauryl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, tricyclodecanyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meta) ) Acrylate and the like. These can be used alone or in combination of two or more. Among these, (meth) acrylate having a hydrocarbon group having 10 or more carbon atoms is particularly preferable.

  In the present specification, “(meth) acrylate” means acrylate or methacrylate, and “(meth) acrylic acid” means acrylic acid or methacrylic acid. In addition, “(meth) acryloyl” means acryloyl or methacryloyl, and “(meth) acrylamide” means “acrylamide or methacrylamide”.

  The polymer block (B) is different from the polymer block (A), and is composed of a polymerizable unsaturated monomer (a3) containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group. The other polymerizable unsaturated monomer (a4) is contained in a mass ratio of 3/97 to 50/50, preferably 5/95 to 40/60. If the amount of the polymerizable unsaturated monomer (a3) containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group is less than this range, the resistance to hot water adhesion of the resulting coating film may be decreased, and many In some cases, the compatibility of the paint blending components and the stability of the paint may be reduced.

  Examples of the polymerizable unsaturated monomer (a3) containing at least one functional group selected from a hydroxyl group, a carboxyl group, and an amino group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3 -Monoesterified product of (meth) acrylic acid such as hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate and a dihydric alcohol having 2 to 8 carbon atoms, the (meth) acrylic acid and 2 to 2 carbon atoms Hydroxyl-containing polymerizable unsaturated monomers such as ε-caprolactone modified products of monoesterified products with dihydric alcohol of 8 and allyl alcohol; carboxyl groups such as (meth) acrylic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate Containing polymerizable unsaturated monomer; N, N-dimethylaminoethyl ) Acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-di-t-butylaminoethyl (meth) acrylate, N, N-dimethylaminobutyl ( Examples thereof include tertiary amino group-containing polymerizable unsaturated monomers such as (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylamide, and these can be used alone or in combination of two or more.

  The other polymerizable unsaturated monomer (a4) is copolymerized with the monomer (a3) other than the polymerizable unsaturated monomer (a3) containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, Stearyl (meth) acrylate, isostear Acrylate (trade name, manufactured by Osaka Organic Chemical Co., Ltd.), cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, tricyclodecanyl (meth) acrylate A polymerizable unsaturated monomer having an isobornyl group such as isobornyl (meth) acrylate; a polymerizable unsaturated monomer having an adamantyl group such as adamantyl (meth) acrylate; and tricyclodecenyl Polymerizable unsaturated monomers having a tricyclodecenyl group such as (meth) acrylate; aromatic ring-containing polymerizable unsaturated monomers such as benzyl (meth) acrylate, styrene, α-methylstyrene, vinyltoluene; Methoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltriisopropoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meta ) Acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane, γ- (meth) acryloyloxypropyltri-n-propoxysilane, γ- Polymerizable unsaturated compounds having hydrolyzable silyl groups such as (meth) acryloyloxypropyltriisopropoxysilane, vinyltriacetoxysilane, and β- (meth) acryloyloxyethyltrimethoxysilane Monomer; perfluoroalkyl (meth) acrylate such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate; polymerizable unsaturated monomer having a fluorinated alkyl group such as fluoroolefin; N-vinylpyrrolidone; Vinyl compounds such as ethylene, butadiene, chloroprene, vinyl propionate, vinyl acetate; 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, 2-methacryloyloxypropyl acid phosphate, etc. Phosphoric acid group-containing polymerizable unsaturated monomer: glycidyl (meth) acrylate, allyl glycidyl ether, 3,4-epoxycyclohexylethyl A) polymerizable unsaturated monomer containing an epoxy group such as acrylate; (meth) acrylonitrile, (meth) acrylamide, methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide, 2- (methacryloyloxy) ethyltrimethylammonium chloride, Nitrogen-containing polymerizable unsaturated monomers such as adducts of glycidyl (meth) acrylate and amines; 2-acrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl (meth) acrylate, allylsulfonic acid, 4-styrenesulfonic acid Polymerizable unsaturated monomers having a sulfonic acid group such as sodium salt and ammonium salt of these sulfonic acids; polymerizable unsaturated monomers having an acid anhydride group such as maleic anhydride, itaconic anhydride, citraconic anhydride, etc. Named, this Al may be used alone or in combination.

  Another polymerizable unsaturated monomer (a4) is a polymerizable unsaturated monomer having a ring structure as a part of the component or an acyclic group having 1 to 8 carbon atoms from the viewpoint of improving the warm water resistance of the resulting coating film. It is desirable to include a (meth) acrylic acid ester having a hydrocarbon group. Examples of the polymerizable unsaturated monomer having a ring structure and the (meth) acrylic acid ester having an acyclic hydrocarbon group having 1 to 8 carbon atoms include styrene, methyl (meth) acrylate, ethyl (meth) acrylate, n- Propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl ( Examples include meth) acrylate, cyclohexyl (meth) acrylate, 4-t-butylcyclohexyl methacrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and tricyclodecenyl (meth) acrylate. These can be used alone or in combination of two or more.

  The block copolymer (I) can be produced by a conventionally known method. Although the manufacturing method is not particularly limited, it is manufactured using, for example, an addition-cleavage type chain transfer agent such as 2,4-diphenyl-4-methyl-1-pentene from the viewpoint of coating film performance and economical efficiency of the manufacturing process. And a method using a catalytic chain transfer agent such as a cobalt complex, and particularly using an addition-cleavage type chain transfer agent such as 2,4-diphenyl-4-methyl-1-pentene. The method is preferred.

  Examples of the production method using an addition-cleavage chain transfer agent that is 2,4-diphenyl-4-methyl-1-pentene include the following (i) and (ii). In this method, from the viewpoint of suppressing a decrease in chain transferability of the polymerization at the time of production, 50 mol% or more of the polymerizable unsaturated monomer constituting the polymer block is a polymerizable unsaturated monomer having a methacryloyl group. Is appropriate.

  (I) In the presence of 2,4-diphenyl-4-methyl-1-pentene and a radical polymerization initiator, a polymerizable unsaturated monomer (a1) containing an epoxy group and other polymerizable unsaturated monomers (a2) The first monomer component containing is radical polymerized to produce a macromonomer having an ethylenically unsaturated group at the end corresponding to the polymer block (A), and then in the presence of the macromonomer, a hydroxyl group, carboxyl A radical addition-cleavage-type chain of a second monomer component containing a polymerizable unsaturated monomer (a3) containing at least one functional group selected from a group and an amino group and another polymerizable unsaturated monomer (a4) An AB block copolymer containing the polymer block (B) is produced by transfer polymerization.

  (Ii) a polymerizable unsaturated monomer containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group in the presence of 2,4-diphenyl-4-methyl-1-pentene and a radical polymerization initiator; A first monomer component containing (a3) and other polymerizable unsaturated monomer (a4) is radically polymerized to produce a macromonomer having an ethylenically unsaturated group at the end corresponding to the polymer block (B). Then, in the presence of the macromonomer, the second monomer component containing the polymerizable unsaturated monomer (a1) containing the epoxy group and the other polymerizable unsaturated monomer (a2) is radically added and cleaved. An AB block copolymer containing the polymer block (A) is produced by transfer polymerization.

  Similarly, the block copolymer (I) is an ABA block polymer, a BAB block polymer, and monomers of the polymer blocks (A) and (B) such as (iii) and (iv) below. A monomer component having a composition different from that of the component may be subjected to radical addition-fragmentation chain transfer polymerization to form an ACB block copolymer, an ABC block copolymer, or the like.

  (Iii) Polymerizable unsaturated monomer (a1) and other polymerizable unsaturated monomer (a2) containing an epoxy group in the presence of 2,4-diphenyl-4-methyl-1-pentene and a radical polymerization initiator To produce a macromonomer having an ethylenically unsaturated group at the end corresponding to the polymer block (A), and then in the presence of the macromonomer, the polymer block ( AC block comprising a polymer block (C) having an ethylenically unsaturated group at its terminal by radical addition-cleavage chain transfer polymerization of a second monomer component having a composition different from that of the monomer component of A) and (B) A polymerizable monomer containing a macromonomer corresponding to a copolymer and further containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group A third monomer component containing the monomer (a3) and other polymerizable unsaturated monomer (a4) is subjected to radical addition-fragmentation chain transfer polymerization to produce an ACB block copolymer containing the polymer block (B). .

  (Iv) A polymerizable unsaturated monomer containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group in the presence of 2,4-diphenyl-4-methyl-1-pentene and a radical polymerization initiator A first monomer component containing (a3) and other polymerizable unsaturated monomer (a4) is radically polymerized to produce a macromonomer having an ethylenically unsaturated group at the end corresponding to the polymer block (B). Then, in the presence of the macromonomer, a second monomer component having a composition different from that of the polymer components of the polymer blocks (A) and (B) is subjected to radical addition-cleavage chain transfer polymerization to end the ethylenic group. A macromonomer corresponding to a BC block copolymer containing a polymer block (C) having a saturated group is produced, and in the presence of the macromonomer, an epoxide is produced. A polymer block (A) containing radically addition-cleavable chain transfer polymerization of a third monomer component containing a polymerizable unsaturated monomer (a1) containing a group and another polymerizable unsaturated monomer (a2) An ACB block copolymer is produced.

  Further, ABAC, BABC, ABCA, BACB and the like may be obtained by multistage polymerization. In these cases, it is sufficient that at least one or more blocks of A and B are included, but if the number of stages is too large, the productivity decreases, so the number of stages is preferably 10 or less, preferably 4 or less. . In the multi-stage polymerization as described above, the unreacted residual monomer component at the previous polymerization may be brought in at the next polymerization.

  The amount of 2,4-diphenyl-4-methyl-1-pentene used is not particularly limited, but is usually 1 to 50 parts by mass, preferably 2 to 100 parts by mass of the first monomer component. It is suitable from the viewpoint of the molecular weight of the resin and the polymerization rate to be in the range of ˜30 parts by mass.

  The radical polymerization can be performed by a method such as solution polymerization in an organic solvent using 2,4-diphenyl-4-methyl-1-pentene which is an addition-cleavage type chain transfer agent.

  Examples of the radical polymerization initiator used for polymerization include cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, 1,1-bis (t-butylperoxy) -3,3,5. -Trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate, cumene hydroperoxide, 2,5-dimethylhexane-2, 5-dihydroperoxide, 1,3-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diisopropylbenzene peroxide, t-Butyl cumyl peroxide, decanoyl peroxy Id, lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, di-t-amyl peroxide, bis (t-butylcyclohexyl) peroxydicarbonate, t-butylperoxybenzoate, 2,5- Peroxide-based polymerization initiators such as dimethyl-2,5-di (benzoylperoxy) hexane and t-butylperoxy-2-ethylhexanoate; 2,2′-azobis (isobutyronitrile), 1 , 1-azobis (cyclohexane-1-carbonitrile), azocumene, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 4,4 ′ -Azobis (4-cyanovaleric acid), 2- (t-butylazo) -2-cyanopropane, 2,2'-azobis ( , 4,4-trimethyl pentane), 2,2'-azobis (2-methylpropane), dimethyl 2,2'-azobis (2-methylpropionate) may be mentioned azo-based polymerization initiators such as.

  The organic solvent is not particularly limited and conventionally known solvents can be used, for example, hydrocarbon solvents such as n-butane, n-hexane, n-heptane, n-octane, cyclopentane, cyclohexane, cyclobutane; toluene, xylene Aromatic solvents such as n-butyl ether, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol, dipropylene glycol dimethyl ether; ethyl acetate, Ester solvents such as n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate; methyl ethyl ketone, methyl isobutyl Tons, ketone solvents such as diisobutyl ketone; may be mentioned amide solvents such as such as N- methylpyrrolidone; ethanol, isopropanol, n- butanol, sec- butanol, alcohol solvents such as isobutanol.

  When performing the first polymerization in solution polymerization in an organic solvent, 2,4-diphenyl-4-methyl-1-pentene, polymerization initiator, polymerizable unsaturated monomer component used in the first stage polymerization , And a method in which the organic solvent is mixed and heated while stirring, 2,4-diphenyl-4-methyl-1-pentene and the organic solvent are charged into the reaction vessel in order to suppress the temperature rise of the system due to reaction heat, and 60 ° C. A method in which a polymerizable unsaturated monomer component and a polymerization initiator used in the first stage polymerization are mixed and dropped over a predetermined time while stirring at a temperature of ˜250 ° C., 2,4-diphenyl- A method in which a part or all of 4-methyl-1-pentene is added to the polymerizable unsaturated monomer component used in the first stage polymerization and a method of mixing or dropping dropwise the polymerization initiator are used.In either case, polymerization may be performed in the presence of an inert gas such as nitrogen or argon as necessary.

  The second and subsequent polymerizations are methods in which the polymerization unsaturated monomer components used in the second and subsequent polymerizations are sequentially polymerized in the same reaction tank after the completion of the first polymerization reaction, and the first polymerization reaction product is reacted. A method in which the tank is charged and the second and subsequent polymerizations are sequentially performed in the presence of the tank, and the first and second polymerization reactions are sequentially performed, and then the third and subsequent polymerizations are performed in the reaction tank in which the second polymerization reaction is performed. The method includes, for example, a method in which the first and second polymerization reactions are sequentially performed, the reaction product is charged into a reaction vessel, and the third and subsequent polymerizations are performed in the presence thereof. In any case, aging time may be taken as necessary, and 2,4-diphenyl-4-methyl-1-pentene, the radical polymerization initiator and the organic solvent described above are directly added to the reaction vessel, It may be added by mixing with a polymerizable unsaturated monomer component used for the second and subsequent polymerizations.

  The polymerization can be generally performed in about 1 to 10 hours per stage. You may provide the additional catalyst process which heats a reaction tank, dripping a polymerization initiator as needed after superposition | polymerization of each step.

  The compounding amount of the monomer component in each of the above steps is based on the total monomer amount constituting the block copolymer (I), and a polymerizable unsaturated monomer containing an epoxy group constituting the polymer block (A) ( Polymerization containing a total amount (M1) of a1) and other polymerizable unsaturated monomers (a2) and at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group constituting the polymer block (B) The total amount (M2) of the polymerizable unsaturated monomer (a3) and the other polymerizable unsaturated monomer (a4) is (M1): 5 to 95% by mass, preferably 10 to 90% by mass, (M2): 5 It is desirable to set it to -95 mass%, Preferably it is 10-90 mass% from the point of coating-film compatibility or coating-material stability. It is desirable that (M1) / (M2) = 1/19 to 19/1, preferably 1/10 to 10/1.

  The block copolymer (I) obtained as described above has a weight average molecular weight of 2,000 to 500,000, preferably 3,000 to 100,000, from the viewpoint of improving the warm water resistance of the resulting coating film. .

  In this specification, the weight average molecular weight and the number average molecular weight are values calculated based on the molecular weight of standard polystyrene from a chromatogram measured by gel permeation chromatograph (GPC). As the gel permeation chromatograph, “HLC8120GPC” (manufactured by Tosoh Corporation) was used. As the columns, four columns of “TSKgel G-4000HXL”, “TSKgel G-3000HXL”, “TSKgel G-2500HXL”, “TSKgel G-2000HXL” (both manufactured by Tosoh Corporation, trade name) were used, Mobile phase: Tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 cc / min, detector: RI

  The block copolymer (I) obtained as described above comprises a solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the polymer block (B). The solubility parameter value (SPB) difference (SPB-SPA) derived from the monomer composition is 0.2 or more, preferably 0.3 to 1.8, so that the compatibility of the paint compounding components is improved. And desirable from the viewpoint of the stability of the paint.

  The solubility parameter value derived from the monomer composition constituting the polymer block in the present invention is a value calculated according to the following procedure.

  Here, the solubility parameter value is a measure of compatibility.In the present invention, a resin for measuring the solubility parameter value is synthesized by the following method, and measured by the cloud point titration method. This is the numerical value obtained. The synthesis of the resin for measuring the solubility parameter value is performed according to the following procedure.

  First, 70 g of dipropylene glycol dimethyl ether is charged into a flask and maintained at 90 ° C. with stirring in a nitrogen atmosphere. A mixture of 100 g of a monomer mixture having the same composition as that of the polymer block, 15 g of dipropylene glycol dimethyl ether and 2 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) was added to this over 3 hours. Add a mixture of 15 g of dipropylene glycol dimethyl ether and 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and ripen at 90 ° C. for 1 hour to measure the solubility parameter value. A solution of the resin is obtained. At this time, in order to ensure the solubility of the resin, a part of dipropylene glycol dimethyl ether may be substituted with another solvent as necessary. Next, the resin is dissolved in a good solvent, the poor solvent is added dropwise thereto, and the amount of the poor solvent required to cause white turbidity is measured. This is performed separately for two types of poor solvent (n-hexane) having a low solubility parameter value and poor solvent (deionized water) having a high solubility parameter value.

  Specifically, first, 0.5 g (solid content) of the resin to be measured is weighed into a 100 ml beaker and dissolved in 10 ml of tetrahydrofuran as a good solvent. Prepare two of these. Next, while stirring one of them, n-hexane, which is a poor solvent, is dropped into this using a burette, and the amount of n-hexane required to become cloudy is measured (this is referred to as H (ml)). For the other, similarly, the same experiment is performed using deionized water, which is a poor solvent, and the amount of deionized water required to become cloudy is measured (this is defined as W (ml)). Titration is performed in a constant temperature room at 20 ° C. The solubility parameter value is obtained by substituting H and W into the following equation.

Solubility parameter value = ((9.52 × (1-α) + 7.24 × α) × (√α) + (9.52 × (1-β) + 23.43 × β) × (√β)) / ((√α) + (√β))
However, α = H / (H + 10) and β = W / (W + 10).

  In addition, 9.52 is derived from the solubility parameter value of tetrahydrofuran, 7.24 is derived from the solubility parameter value of n-hexane, and 23.43 is derived from the solubility parameter value of deionized water.

  In the coating composition of the present invention, the content of the block copolymer (I) is 3 to 40% by mass, preferably 10 to 30% by mass, based on the total resin solid content in the coating composition. From the viewpoint of chipping resistance and adhesion of the obtained coating film.

Hydroxyl-containing urethane resin (II)
In the present invention, the hydroxyl group-containing urethane resin (II) can be obtained by reacting a polyol and a polyisocyanate by a method known per se.

  The hydroxyl group-containing urethane resin (II) preferably has a hydroxyl value in the range of 1 to 100 mgKOH / g, from the viewpoint of chipping resistance, smoothness and water resistance of the resulting coating film, and 10 to 80 mgKOH / g. More preferably, it is in the range of 20-50 mgKOH / g.

  In addition, the hydroxyl group-containing urethane resin (II) preferably has a weight average molecular weight in the range of 5,000 to 100,000 from the viewpoint of chipping resistance, smoothness and water resistance of the resulting coating film. More preferably, it is within the range of 20,000 to 70,000, and even more preferably within the range of 30,000 to 50,000.

  The hydroxyl group-containing urethane resin (II) preferably has a number average molecular weight in the range of 2,000 to 20,000 from the viewpoint of chipping resistance, smoothness and water resistance of the resulting coating film. More preferably within the range of 4,000 to 16,000, still more preferably within the range of 5,000 to 12,000, and particularly preferably within the range of 6,000 to 9,900. .

  Especially, it is preferable to use the hydroxyl group-containing urethane resin which has a branched structure from a viewpoint of chipping resistance of the obtained coating film, adhesiveness, finish, and gasohol property, and also the hydroxyl group-containing urethane resin which has especially a nurate structure ( U) is preferred.

[Hydroxyl-containing urethane resin having a nurate structure (U)]
A hydroxyl group-containing urethane resin (U) having a nurate structure is obtained by reacting a polyol component (p) comprising a cyclic polyol compound (p1) having a nurate structure and another polyol compound (p2) with a polyisocyanate compound (q). can get.

[Polyol component (p)]
The polyol component (p) is composed of a cyclic polyol compound (p1) having the following nurate structure and another polyol compound (p2).

[Cyclic polyol compound having a nurate structure (p1)]
Examples of the cyclic polyol compound (p1) having a nurate structure include tris (hydroxyalkyl) isocyanurate such as tris (hydroxyethyl) isocyanurate, tris (hydroxypropyl) isocyanurate and tris (hydroxybutyl) isocyanurate, the tris Ε-caprolactone modified form of (hydroxyalkyl) isocyanurate, tris (hydroxyethyl) isocyanurate, diol compound and dicarboxylic acid, and the hydroxyl group in tris (hydroxyethyl) isocyanurate and diol compound is converted to a carboxyl group in dicarboxylic acid. Esterified tris (hydroxyethyl) isocyanurate obtained by reacting in excess, and polyisocyanate compound having nurate structure and diolization And things, hydroxyl groups in the diol compound is the reaction product obtained by reacting with excess state to isocyanate groups in the polyisocyanate compounds and the like having a isocyanurate structure. These can be used alone or in combination of two or more.

  Among these, from the viewpoint of chipping resistance and water resistance of the obtained coating film, tris (2-hydroxyethyl) isocyanurate and ε-caprolactone modified form of tris (2-hydroxyethyl) isocyanurate are preferable. 2-Hydroxyethyl) isocyanurate is more preferred.

In addition, from the viewpoint of chipping resistance and water resistance of the obtained coating film, the content ratio C _p1 of the cyclic polyol compound (p1) having the nurate structure with respect to the total amount of the polyol component (p) is in the range of 1 to 75 mol%. It is preferable that it is in the range of 10 to 65 mol%, more preferably in the range of 20 to 60 mol%, and particularly preferably in the range of 40 to 50 mol%.

[Other polyol compounds (p2)]
The other polyol compound (p2) is a polyol compound other than the cyclic polyol compound (p1) having the nurate structure.

  Examples of the other polyol compound (p2) include polyether polyol, polycarbonate polyol, polyester polyol, polyether ester polyol, polyalkylene polyol, and polyacryl polyol. These can be used alone or in combination of two or more.

  Among these, it is preferable to use polyether polyol and / or polycarbonate polyol from the viewpoint of water resistance of the resulting coating film.

  Examples of the polyether polyol include polymers or copolymers of alkylene oxides (for example, ethylene oxide, propylene oxide and butylene oxide), polymers or copolymers of heterocyclic ethers (for example, tetrahydrofuran), and the like. Examples thereof include copolymers of alkylene oxide and heterocyclic ether. These can be used alone or in combination of two or more.

  Specific examples of the polyether polyol include, for example, polyethylene glycol, polypropylene glycol, polyethylene-polypropylene glycol (block or random copolymer), polyethylene-tetramethylene glycol (block or random copolymer), polytetramethylene ether glycol. And polyoxyalkylene glycols such as polyhexamethylene ether glycol and polyhydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol and 1,2,4-butanetriol as initiators, Examples include compounds obtained by adding alkylene oxide (for example, ethylene oxide, propylene oxide, butylene oxide, etc.) to the initiator. These can be used alone or in combination of two or more.

  As said polycarbonate polyol, the polycarbonate polyol obtained by reaction with carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate, and phosgene, and a polyol can be used, for example.

  Examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 3- Methylpentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,3-propanediol, 2-methyl-1,5-pentanediol, bisphenol A, Diols such as hydrogenated bisphenol A, trimethylolpropane and cyclohexanedimethanol, and trimethylolmethane, trimethylolethane, trimethylolpropane, trimethylolbutane, glycerin, 1,2,6-hexanetriol, trieta Amines, cyclohexane-1,2,3-trimethanol, cyclohexane-1,2,4-trimethanol, cyclohexane-1,3,5-trimethanol, reaction products of monoethanolamine and glycidol and pentaerythritol And triols. These can be used alone or in combination of two or more.

  As the polyol, it is preferable to use a diol. Examples of the diol include 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, and 2-methyl-1,5-pentanediol from the viewpoint of chipping resistance of the resulting coating film. Preferably mentioned. Among these, 1,6-hexanediol is preferable.

  A commercially available product can be used as the polycarbonate polyol. Examples of commercially available products include “T-5650J” (diol components: 1,6-hexanediol and 1,5-pentanediol), “T-4671”, and “T-4672” (all manufactured by Asahi Kasei Chemicals Corporation). Diol components: 1,6-hexanediol and 1,4-butanediol) and “UM-CARB90” (diol components: 1,6-hexanediol and 1,4-cyclohexanedimethanol) and UH manufactured by Ube Industries, Ltd. -CARB200 "(diol component: 1,6-hexanediol) and the like.

  Among these, from the viewpoint of water resistance of the resulting coating film, the other polyol compound (p2) is a polyether diol compound (p2-1-1) represented by the following general formula (1) and the following general formula (2). It is preferable to contain at least one diol compound (p2-1) of the polycarbonate diol compound (p2-1-2) represented by Especially, the said polycarbonate diol compound (p2-1-2) is more preferable from a viewpoint of the chipping resistance of the coating film formed.

In formula (1), R ¹ represents an alkylene group having 3 or more carbon atoms. R ¹ has 3 or more carbon atoms, preferably 3 to 6 and more preferably 4 to 5. m represents an integer of 2 to 100, preferably 4 to 80, and more preferably 8 to 40. Each R ¹ in the m repeating units may be the same or different from each other.

In Formula (2), a plurality of R ² each independently represents an alkylene group having 3 or more carbon atoms. R ² has 3 or more carbon atoms, preferably 3 to 22, more preferably 4 to 9, and still more preferably 6 to 9. n represents an integer of 2 to 100, preferably 4 to 80, and more preferably 8 to 40.

  Examples of the polyether diol compound (p2-1-1) include polyoxypropylene glycol, polytetramethylene ether glycol, polypentamethylene ether glycol, and polyhexamethylene ether glycol. These can be used alone or in combination of two or more. Of these, polytetramethylene ether glycol is preferable.

  A commercial item can be used as said polyether diol compound (p2-1-1). Examples of commercially available products include “New Pole PP-1000” and “New Pole PP-2000” manufactured by Sanyo Kasei Co., Ltd., “PTMG650”, “PTMG1000”, “PTMG1500”, “PTMG2000” and “PTMG2000” manufactured by Mitsubishi Chemical Corporation. PTMG3000 "and" POLYTHF1000S "manufactured by BASF-Japan can be used.

In addition, from the viewpoint of chipping resistance and water resistance of the obtained coating film, the content ratio C _p2-1-1 of the polyether diol compound (p2-1-1) with respect to the total amount of the polyol component (p) is 10 to 10. It is preferably in the range of 99 mol%, more preferably in the range of 20 to 90 mol%, further preferably in the range of 30 to 80 mol%, and in the range of 40 to 70 mol%. Particularly preferred.

In addition, from the viewpoint of chipping resistance and water resistance of the resulting coating film, the content ratio C _{p1 of the} cyclic polyol compound (p1) having a nurate structure with respect to the total amount of the polyol component (p) and the total amount of the polyol component (p) The ratio C _p1 / C _p2-1-1 to the content ratio C _p2-1-1 of the polyether diol compound (p2-1-1) with _{respect to} is in the range of 1/99 to 75/25. Preferably, it is in the range of 10/90 to 70/30, more preferably in the range of 15/85 to 60/40, and in the range of 30/70 to 45/55. Particularly preferred.

  The hydroxyl value of the polyether diol compound (p2-1-1) is preferably in the range of 10 to 180 mgKOH / g, preferably in the range of 30 to 150 mgKOH / g, from the viewpoint of water resistance of the resulting coating film. It is more preferable that it is in the range of 50 to 120 mgKOH / g.

  The number average molecular weight of the polyether diol compound (p2-1-1) is within the range of 400 to 10,000 from the viewpoint of chipping resistance, smoothness and water resistance of the resulting coating film. Preferably, it is in the range of 500 to 5,000, more preferably in the range of 700 to 2,500, and particularly preferably in the range of 800 to 1,500.

  As the polycarbonate diol compound (p2-1-2), for example, a polycarbonate diol obtained by a reaction of a carbonic acid derivative such as diphenyl carbonate, dimethyl carbonate and phosgene with a diol having an alkylene group having 3 or more carbon atoms is used. be able to.

  Examples of the diol having an alkylene group having 3 or more carbon atoms include 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 3-methylpentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,5-pentanediol and the like Can be mentioned. These can be used alone or in combination of two or more.

  Of these, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and 2-methyl-1,5-pentanediol are preferred from the viewpoint of chipping resistance of the resulting coating film. , 6-hexanediol is more preferred.

  A commercial item can be used as said polycarbonate diol compound (p2-1-2). Examples of commercially available products include “T-5650J”, “T-4671” and “T-4672” manufactured by Asahi Kasei Chemicals Corporation, and “UH-CARB50”, “UH-CARB100”, “UH-” manufactured by Ube Industries, Ltd. CARB200 "," UH-CARB300 ", etc. can be mentioned.

Moreover, from the viewpoint of chipping resistance and water resistance of the obtained coating film, the content ratio C _p2-1-2 of the polycarbonate diol compound (p2-1-2) with respect to the total amount of the polyol component (p) is 10 to 99 mol. %, Preferably in the range of 20-90 mol%, more preferably in the range of 30-80 mol%, particularly preferably in the range of 40-70 mol%. preferable.

From the viewpoint of chipping resistance and water resistance of the resulting coating film, the content ratio C _{p1 of the} cyclic polyol compound (p1) having a nurate structure relative to the total amount of the polyol component (p) and the total amount of the polyol component (p) The ratio C _p1 / C _{p2-1-2 to} the content ratio C _p2-1-2 of the polycarbonate diol compound (p2-1-2) is preferably in the range of 1/99 to 75/25, More preferably within the range of 10/90 to 70/30, still more preferably within the range of 15/85 to 60/40, and particularly preferably within the range of 30/70 to 45/55. .

  The hydroxyl value of the polycarbonate diol compound (p2-1-2) is preferably in the range of 10 to 240 mgKOH / g, and in the range of 30 to 150 mgKOH / g, from the viewpoint of water resistance of the resulting coating film. More preferably, it is more preferably in the range of 50 to 120 mg KOH / g.

  The number average molecular weight of the polycarbonate diol compound (p2-1-2) is preferably in the range of 400 to 10,000 from the viewpoint of chipping resistance, smoothness and water resistance of the resulting coating film. , More preferably in the range of 500 to 5,000, still more preferably in the range of 800 to 3,500, and particularly preferably in the range of 1,500 to 2,500.

Further, when the polyether diol compound (p2-1-1) and the polycarbonate diol compound (p2-1-2) are used in combination as the diol compound (p2-1), the chipping resistance and water resistance of the resulting coating film are obtained. In view of the above, the content ratio C _p2-1 of the diol compound (p2-1) with respect to the total amount of the polyol component (p) is preferably in the range of 10 to 99 mol%, and in the range of 20 to 90 mol%. More preferably, it is more preferably in the range of 30 to 80 mol%, and particularly preferably in the range of 40 to 70 mol%.

In addition, from the viewpoint of chipping resistance and water resistance of the coating film obtained, the content ratio C _{p1 of the} cyclic polyol compound (p1) having the nurate structure to the total amount of the polyol component (p) and the total amount of the polyol component (p) preferably the ratio _C p1 _{/ C p2-1} the content _{C p2-1} of the diol compound (p2-1) is in the range of 1 / 99-75 / 25 for, 10 / 90-70 / More preferably, it is within the range of 30, more preferably within the range of 15/85 to 60/40, and particularly preferably within the range of 30/70 to 45/55.

[Polyisocyanate compound (q)]
The polyisocyanate compound (q) is a compound having at least two isocyanate groups in one molecule. Examples of the polyisocyanate compound (q) include aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates and aromatic polyisocyanates, and derivatives of these polyisocyanates. These can be used alone or in combination of two or more.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3. Aliphatic diisocyanates such as butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dimer acid diisocyanate and methyl 2,6-diisocyanatohexanoate (common name: lysine diisocyanate) and 2 , 6-Diisocyanatohexanoic acid 2-isocyanatoethyl, 1,6-diisocyanato-3-isocyanatomethylhexane, 1,4,8-triisocyanatooctane 1,6,11-triisocyanatoundecane, 1,8-diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane and 2,5,7-trimethyl-1,8-diisocyanato-5 -Aliphatic triisocyanates such as isocyanatomethyloctane.

  Examples of the alicyclic polyisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name) : Isophorone diisocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane (common name: hydrogenated xylylene diisocyanate) or Mixtures thereof, alicyclic diisocyanates such as methylenebis (1,4-cyclohexanediyl) diisocyanate (common name: hydrogenated MDI) and norbornane diisocyanate and 1,3,5-triisocyanate Socyanatocyclohexane, 1,3,5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 2- (3 -Isocyanatopropyl) -2,6-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 3- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo ( 2.2.1) Heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 6- (2-isocyanate) Natoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 5- (2-isocyanatoethyl) -2-isocyanate Tomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2.1) -heptane and 6- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2.1) Alicyclic triisocyanates such as heptane.

  Examples of the araliphatic polyisocyanate include methylene bis (1,4-phenylene) diisocyanate (common name: MDI), 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω, ω′-diisocyanato- Aromatic aliphatic diisocyanates such as 1,4-diethylbenzene and 1,3- or 1,4-bis (1-isocyanato-1-methylethyl) benzene (common name: tetramethylxylylene diisocyanate) or mixtures thereof and 1,3 , 5-triisocyanatomethylbenzene and other araliphatic triisocyanates.

  Examples of the aromatic polyisocyanate include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, or a mixture thereof. Aromatic diisocyanates such as 4,4′-toluidine diisocyanate and 4,4′-diphenyl ether diisocyanate, triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatobenzene and 2 And aromatic triisocyanates such as 4,4′-diphenylmethane-2,2 ′, 5,5′-tetraisocyanate and the like.

  Examples of the polyisocyanate derivative include dimer, trimer, biuret, allophanate, uretdione, uretoimine, isocyanurate, oxadiazine trione, polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI) of the polyisocyanate compound. And crude TDI.

  The polyisocyanate compound (q) is preferably an alicyclic diisocyanate or a derivative of the alicyclic diisocyanate from the viewpoint of chipping resistance, water resistance, smoothness and sharpness of the resulting coating film. Diisocyanate is more preferred.

[Method for producing hydroxyl group-containing urethane resin (U) having a nurate structure]
The hydroxyl group-containing urethane resin (U) having a nurate structure is obtained by reacting a polyol component (p) composed of the cyclic polyol compound (p1) having the nurate structure and another polyol compound (p2) with a polyisocyanate compound (q). Obtained by.

  Specifically, for example, in the polyol component (p) and the polyisocyanate compound (q), the hydroxyl group in the polyol component (p) is excessive with respect to the isocyanate group in the polyisocyanate compound (q). It can obtain by making it react.

  The blending ratio of the polyol component (p) and the polyisocyanate compound (q) is determined from the number of moles of hydroxyl groups in the polyol component (p) and the number of polysoles from the viewpoint of chipping resistance, smoothness and water resistance of the resulting coating film. It is preferable that the ratio OH / NCO with the number of moles of isocyanate groups in the isocyanate compound (q) is adjusted to be in the range of 51/49 to 80/20, and in the range of 53/47 to 70/30. Is more preferable, and the range of 55/45 to 65/35 is more preferable.

  The reaction of the polyol component (p) and the polyisocyanate compound (q) can be performed by a conventionally known method. Specifically, for example, the polyol component (p) and the polyisocyanate compound (q) are preferably 10 to 170 ° C., more preferably 20 by using an organic solvent inert to a hydroxyl group and an isocyanate group as a reaction solvent. The reaction can be carried out at a temperature in the range of ˜150 ° C., preferably for 1 to 24 hours, more preferably in the range of 2 to 8 hours.

  Examples of the reaction solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, N-methylpyrrolidone, toluene, and xylene. These can be used alone or in combination of two or more.

  In the above reaction, a catalyst, a reaction terminator, a chain extender and the like can be used as necessary.

  Examples of the catalyst include salts of metals such as dibutyltin dilaurate, dioctyltin dilaurate, lead octylate and tetra n-butyl titanate with organic and inorganic acids, organic metal derivatives, organic amines such as triethylamine, and diazabicyclone. Examples include decene catalysts. These can be used alone or in combination of two or more.

  As the reaction terminator, for example, monofunctional compounds such as monoalcohols and monoamines, and compounds having two types of functional groups having different reactivities with respect to isocyanate can be used.

  Specific examples of the reaction terminator include monoalcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol and tert-butyl alcohol, monoethylamine, n- Examples thereof include monoamines such as propylamine, diethylamine, di-n-propylamine and di-n-butylamine, and alkanolamines such as monoethanolamine and diethanolamine. These can be used alone or in combination of two or more.

  Of these, alkanolamines are preferable in that the reaction can be easily controlled. Moreover, the said reaction terminator can be used in order to adjust the number average molecular weight of the hydroxyl-containing urethane resin (U) which has a nurate structure.

  As the chain extender, for example, water and polyamine can be used.

  Examples of the polyamine include aliphatic polyamines such as ethylenediamine, N-hydroxyethylethylenediamine, tetramethylenediamine, hexamethylenediamine and diethylenetriamine, 4,4′-diaminodicyclohexylmethane, 1,4-diaminocyclohexane and isophoronediamine. Aliphatic polyamines having aromatic rings such as alicyclic polyamines, xylylenediamine and tetramethylxylylenediamine, aromatic polyamines such as 4,4′-diaminodiphenylmethane, tolylenediamine and phenylenediamine, and hydrazine, carbodihydrazide, adipine And hydrazines such as acid dihydrazide, sebacic acid dihydrazide and phthalic acid dihydrazide. These can be used alone or in combination of two or more.

  In the coating composition of the present invention, the content of the hydroxyl group-containing urethane resin (II) is 1 to 30% by mass, preferably 10 to 25% by mass, based on the total resin solid content in the coating composition. From the viewpoint of chipping resistance, adhesion, finish, and gasohol property of the resulting coating film.

Polyolefin resin (III)
In the present invention, examples of the polyolefin resin (III) include polyolefin resins and chlorinated polyolefin resins. Especially, it is preferable that it is a chlorinated polyolefin resin. When using chlorinated polyolefin resin, the chlorination rate is 50 mass% or less, Preferably it is 10-45 mass%, More preferably, it is 15-30 mass%. A non-chlorinated polyolefin resin and a chlorinated polyolefin resin may be used in combination.

  As the polyolefin resin, for example, at least one olefin selected from olefins having 2 to 10 carbon atoms, particularly 2 to 4 carbon atoms such as ethylene, propylene, butylene, hexene, octene, and decene is (co) polymerized. Polyolefins obtained from the above, and unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid, (meth) acrylic acid (preferably unsaturated mono- or di-carboxylic acids) or unsaturated carboxylic acids thereof. Those obtained by graft polymerization according to a method known per se can be used, and those modified with maleic anhydride are preferred. Further, the unsaturated carboxylic acid or anhydride-modified polyolefin may be acrylic-modified, amine-modified, or alcohol-modified. Examples of polymerizable unsaturated monomers that can be used for acrylic modification include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and cyclohexyl (meth). Alkyl esters of (meth) acrylic acid such as acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; (meth) acrylic acid, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) ) Acrylic monomers such as acrylate, (meth) acrylamide, (meth) acrylonitrile; and styrene, and the like. These may be used alone or in combination of two or more. As the amine and alcohol, known ones can be used alone or in combination of two or more.

  Examples of the chlorinated polyfin resin include a resin obtained by chlorinating the above-mentioned polyolefin, and a maleic anhydride-modified chlorinated polyolefin resin obtained by reacting maleic anhydride after producing a chlorinated polyolefin resin. These may be further acrylic-modified, amine-modified, or alcohol-modified. These modifications can be performed in the same manner as described above.

  By using a maleic anhydride-modified polyolefin resin and / or a chlorinated polyolefin resin, it is possible to improve adhesion to the polyolefin resin molded article and paint stability.

  The polyolefin resin and the chlorinated polyolefin resin may have a functional group such as a hydroxyl group or a carboxyl group in the molecule, and the weight average molecular weight is 3,000 to 300,000, particularly 5,000 to 150,000. The range of is suitable.

  In the coating composition of the present invention, the content of the polyolefin resin (III) is 20 to 50% by mass, preferably 25 to 45% by mass, based on the total resin solid content in the coating composition. The resulting coating film is suitable from the viewpoint of chipping resistance, adhesion, finish and gasohol.

Curing agent (IV)
In the present invention, examples of the curing agent (IV) include polyisocyanate compounds, blocked polyisocyanate compounds, melamine resins, epoxy resins, and polycarbodiimide compounds.

  Examples of the polyisocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and lysine diisocyanate; burette type adducts, isocyanurate ring adducts of these aliphatic polyisocyanates, Allophanate type adducts, uretdione type adducts; alicyclic diisocyanates such as isophorone diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4- or -2,6-diisocyanate; -Type diisocyanate burette-type adducts, isocyanurate cycloadducts; xylylene diisocyanate, tetramethylxylylene diisocyanate , Aromatic diisocyanate compounds such as tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate; burette-type adducts of these aromatic diisocyanates, isocyania Nurate ring adducts; hydrogenated MDI and derivatives of hydrogenated MDI; isocyanates at the hydroxyl groups of polyols such as ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylolpropionic acid, polyalkylene glycol, trimethylolpropane, hexanetriol Urethane adducts obtained by reacting polyisocyanate compounds in an excess ratio of groups; Burette type adducts of these urethanated adducts, with isocyanurate rings Mention may be made of things like.

  The blocked polyisocyanate compound is obtained by adding a blocking agent to the isocyanate group of the polyisocyanate compound, and the blocked polyisocyanate compound produced by the addition is stable at room temperature, but the baking temperature of the coating film ( When heated to about 80 to about 200 ° C.), it is desirable that the blocking agent can be dissociated to regenerate free isocyanate groups. Examples of the blocking agent that satisfies such requirements include, for example, phenol, lactam, alcohol, ether, oxime, active methylene, mercaptan, acid amide, imide, amine, imidazole, and pyrazole. And the like blocking agents. Among these, a blocked polyisocyanate compound with an active methylene-based blocking agent is preferable from the viewpoint of curability at low temperatures.

  As the melamine resin, an alkyl etherified melamine resin etherified with an alkyl group such as methyl, ethyl, n-butyl, isobutyl, hexyl, 2-ethylhexyl is particularly preferable. These melamine resins may further have a methylol group, an imino group or the like. The melamine resin usually has a number average molecular weight in the range of 500 to 5,000, particularly 800 to 3,000.

  In the coating composition of the present invention, the content of the curing agent (IV) is 5 to 20% by mass, preferably 7 to 15% by mass, based on the total resin solid mass in the coating composition. From the viewpoint of chipping resistance, adhesion, finish, and gasohol property of the coating film to be formed.

Conductive pigment (V)
The conductive pigment (V) used in the present invention is not particularly limited as long as it can impart conductivity to the formed coating film, and is in the form of particles, flakes, fibers (including whiskers). Any of these shapes can be used. Specific examples include conductive carbon such as conductive carbon black, carbon nanotube, carbon nanofiber, and carbon microcoil; metal powder such as silver, nickel, copper, graphite, and aluminum, and further doped with antimony. Tin oxide coated with phosphorus, tin oxide doped with phosphorus, acicular titanium oxide surface coated with tin oxide / antimony, antimony oxide, zinc antimonate, indium tin oxide, carbon and graphite whiskers coated with tin oxide, etc. A pigment having a flaky mica surface coated with a conductive metal oxide such as tin oxide or antimony-doped tin oxide; and a conductive pigment containing tin oxide and phosphorus on the surface of titanium dioxide particles. These can be used alone or in combination of two or more. Of these, conductive carbon can be particularly preferably used.

  In the coating composition of the present invention, the content of the conductive carbon (V) is 5 to 40% by mass, preferably 10 to 35% by mass, based on the total resin solid mass in the coating composition. The resulting coating film is suitable from the viewpoint of chipping resistance, adhesion, finish and gasohol.

Other Components The coating composition of the present invention comprises the block copolymer (I), the hydroxyl group-containing urethane resin (II), the polyolefin resin (III), the curing agent (IV), and the conductive pigment (V) as essential components. Furthermore, it can contain resin components such as polyester resin, acrylic resin other than component (I), and epoxy resin, phenol resin, and polycarbonate resin, if necessary.

  The resin component contains at least one of the hydroxyl group-containing polyester resin (VI), the hydroxyl group-containing acrylic resin and the epoxy resin other than the component (I), particularly chipping resistance, adhesion, finish, and gasohol. From the viewpoint of sex.

  The hydroxyl group-containing polyester resin (VI) can be obtained, for example, by subjecting a polybasic acid and a polyhydric alcohol to an esterification reaction with an excess of hydroxyl groups by a method known per se. A polybasic acid is a compound having two or more carboxyl groups in one molecule. For example, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, pyro Examples include merit acid, itaconic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, hymic acid, succinic acid, het acid, and anhydrides thereof. The polyhydric alcohol is a compound having two or more hydroxyl groups in one molecule, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, butylene glycol, hexanediol, 2-ethyl-2- Examples include butyl-1,3-propanediol, cyclohexanedimethanol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol and the like. Introduction of a hydroxyl group can be performed, for example, by using a polyhydric alcohol having 3 or more hydroxyl groups in one molecule. Further, as the polyester resin, a fatty acid-modified polyester resin modified with a fatty acid such as soybean oil fatty acid, castor oil fatty acid, dehydrated castor oil fatty acid or the like can also be used. Moreover, the polyester resin may be modified with an epoxy compound such as butyl glycidyl ether, alkylphenyl glycidyl ether, or neodecanoic acid glycidyl ester, if necessary.

  The hydroxyl group-containing polyether resin (VI) usually has a hydroxyl value of 10 to 150 mgKOH / g, particularly 50 to 85 mgKOH / g, an acid value of 50 mgKOH / g or less, particularly 1 to 30 mgKOH / g, and a number average. A molecular weight in the range of 1,500 to 100,000, particularly 2,000 to 30,000 is suitable.

  In the coating composition of the present invention, when the hydroxyl group-containing polyester resin (VI) is used, the amount used is 5 to 15% by mass, preferably 7 to 20% by mass, based on the total resin solid content in the coating composition. It is preferable from the viewpoint of chipping resistance, adhesion, finish, and gasohol property of the resulting coating film.

  A hydroxyl group-containing acrylic resin other than component (I) is usually a hydroxyl group-containing polymerizable unsaturated monomer, a (meth) acrylic acid alkyl ester monomer and, if necessary, other polymerizable unsaturated monomers, a known polymerization method, For example, it can be obtained by polymerization by a solution polymerization method or the like.

  The hydroxyl group-containing polymerizable unsaturated monomer is a compound having a hydroxyl group and a polymerizable unsaturated group, and examples thereof include (meth) acrylic compounds such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. Examples include monoesterified products of acids and diols having 2 to 10 carbon atoms, and ε-caprolactone modified products of these compounds having a hydroxyl group and a (meth) acryloyl group. Examples of (meth) acrylic acid alkyl ester monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, ( Examples thereof include monoesterified products of (meth) acrylic acid and monoalcohol having 1 to 20 carbon atoms such as (meth) acrylic acid-2-ethylhexyl, (meth) lauryl acrylate, and stearyl (meth) acrylate. The other polymerizable unsaturated monomer is a compound having a polymerizable unsaturated group other than the hydroxyl group-containing polymerizable unsaturated monomer and the (meth) acrylic acid alkyl ester monomer, and examples thereof include (meth) acrylic acid and maleic acid. Examples thereof include carboxyl group-containing polymerizable unsaturated monomers such as: epoxy group-containing polymerizable unsaturated monomers such as glycidyl (meth) acrylate; (meth) acrylamide, acrylonitrile, styrene, vinyl acetate, vinyl chloride and the like.

  The hydroxyl group-containing acrylic resin other than component (I) usually has a hydroxyl value of 10 to 100 mgKOH / g, particularly 50 to 90 mgKOH / g, and an acid value of 10 to 100 mgKOH / g, particularly 30 to 60 mgKOH / g. Of these, the weight average molecular weight is suitably in the range of 2,000 to 100,000, particularly 3,000 to 50,000.

  In the coating composition of the present invention, when a hydroxyl group-containing acrylic resin other than component (I) is used, the amount used thereof is 5 to 15% by mass, preferably 7 to 7%, based on the total resin solid content in the coating composition. 20% by mass is preferable from the viewpoint of chipping resistance, adhesion, finish, and gasohol property of the resulting coating film.

  Examples of the epoxy resin include bisphenol A type epoxy resin; bisphenol F type epoxy resin; novolac type epoxy resin; hydrogenated bisphenol A type epoxy resin; ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene Glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, hexahydrophthalic acid diglycidyl ester, glycerin polyglycidyl ether, diglycerin Aliphatic types such as polyglycidyl ether and polyglycerin polyglycidyl ether Epoxy resins. These can be used alone or in combination of two or more.

  Examples of the commercially available epoxy resin include “jER828,” “jER828,” “jER828EL,” “jER828XA,” “jER834” (manufactured by Japan Epoxy Resin Co., Ltd.), “EPICLON840”, “EPICLON840-S”, “EPICLON 850”, “EPICLON 850-S”, “EPICLON 850-CRP”, “EPICLON 850-LC” (manufactured by DIC), “Epototo YD-127”, “Epototo YD-128” (manufactured by Toto Kasei) Bisphenol A type epoxy resins such as “Lika Resin BPO-20E” and “Lika Resin BEO-60E” (manufactured by Shin Nippon Chemical Co., Ltd.); “jER806”, “jER807” (manufactured by Japan Epoxy Resin), “EPICLON830” " Bisphenol F type epoxy resins such as “EPICLON830-S”, “EPICLON835” (manufactured by DIC), “Epototo YDF-170” (manufactured by Tohto Kasei), etc .; novolaks such as “jER152” (manufactured by Japan Epoxy Resin) Type epoxy resin: “jERYX8000”, “jERYX8034” (manufactured by Japan Epoxy Resin Co., Ltd.), “Epototo ST-3000” (manufactured by Tohto Kasei Co., Ltd.), “Likaresin HBE-100” (manufactured by Shin Nippon Rika Co., Ltd.) “Denacol EX -252 "(manufactured by Nagase ChemteX Corp.)," SR-HBA "(manufactured by Sakamoto Pharmaceutical Co., Ltd.) and other hydrogenated bisphenol A type epoxy resins;" YED205 "," YED216M "," YED216D " Japan Epoxy Resin Co., Ltd.), “Epototo YH-300” “Epototo YH-301”, “Epototo YH-315”, “Epototo YH-324”, “Epototo YH-325” (manufactured by Toto Kasei Co., Ltd.), “Denacol EX-211”, “Denacol EX-212”, “DENACOL EX-212L”, “DENACOL EX-214L”, “DENACOL EX-216L”, “DENACOL EX-313”, “DENACOL EX-314”, “DENACOL EX-321”, “DENACOL EX-321L”, “ Denacol EX-411, Denacol EX-421, Denacol EX-512, Denacol EX-521, Denacol EX-611, Denacol EX-612, Denacol EX-614, Denacol "EX-614B", "Denacol EX-622", "Denacol EX- "810", "Denacol EX-811", "Denacol EX-850", "Denacol EX-850L", "Denacol EX-851", "Denacol EX-821", "Denacol EX-830", "Denacol EX-832" ”,“ Denacol EX-841 ”,“ Denacol EX-861 ”,“ Denacol EX-911 ”,“ Denacol EX-941 ”,“ Denacol EX-920 ”,“ Denacol EX-931 ”(above, manufactured by Nagase ChemteX Corporation) ), “SR-NPG”, “SR-16H”, “SR-16HL”, “SR-TMP”, “SR-PG”, “SR-TPG”, “SR-4PG”, “SR-2EG”, “SR-8EG”, “SR-8EGS”, “SR-GLG”, “SR-DGE”, “SR-DGE”, “SR-4GL”, “SR 4GLS "," SR-SEP "(or, BanHajime manufactured Yakuhin Kogyo Co., Ltd.) aliphatic epoxy resins such as are exemplified.

  The epoxy resin has an epoxy equivalent of 110 to 500, preferably 130 to 350, more preferably 150 to 250, from the viewpoint of chipping resistance, adhesion, finish, and gasohol property of the coating film to be formed. It is preferable to be within.

  The epoxy resin preferably has a molecular weight in the range of 170 to 2,800, preferably 200 to 800 from the viewpoint of chipping resistance, adhesion, finish, and gasohol properties of the coating film to be formed. It is. Moreover, it is preferable that this epoxy resin has a hydroxyl group from a viewpoint of the chipping resistance of the coating film formed, adhesiveness, finish property, and gasohol property.

  In the coating composition of the present invention, the amount used when an epoxy resin is used is 1 to 10% by mass, preferably 2 to 7% by mass, based on the total resin solid content in the coating composition. The resulting coating film is suitable from the viewpoint of chipping resistance, adhesion, finish and gasohol.

  Known phenol resins and polycarbonate resins can be used.

  The coating composition of the present invention further includes coatings such as color pigments, extender pigments, organic solvents, silane coupling agents, curing catalysts, thickeners, antifoaming agents, surface conditioners, and film-forming aids as necessary. Additives can be contained.

  Examples of color pigments include titanium oxide, carbon black, chrome lead, ocher, yellow iron oxide, Hansa Yellow, pigment yellow, chrome orange, chrome vermillion, permanent orange, amber, permanent red, brilliant carmine, fast violet, and methyl violet. Examples include rake, ultramarine, bitumen, cobalt blue, phthalocyanine blue, pigment green, naphthol green, and aluminum paste. These can be used alone or in combination of two or more.

  Examples of extender pigments include talc, silica, calcium carbonate, barium sulfate, and zinc white (zinc oxide). These can be used alone or in combination of two or more.

The organic solvent is not particularly limited as long as it can mix and dissolve or disperse the above-described resin components. For example, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, alcohol solvents, ester solvents And solvents such as ketone solvents.

  Examples of the silane coupling agent include 2- (3,4 epoxy cyclohexyl) ethyl trialkoxysilane, 3-glycidoxypropyltrialkoxysilane, 3-glycidoxypropylmethyl dialkoxysilane, N-2- (amino Ethyl) -3-aminopropylmethyl dialkoxysilane, N-2- (aminoethyl) -3-aminopropyltrialkoxysilane, 3-aminopropyltrialkoxysilane, 3-aminopropylmethyl dialkoxysilane, 3-mercaptopropyl Methyl dialkoxysilane, 3-mercaptopropyltrialkoxysilane, N-phenyl-3-aminopropyltrialkoxysilane, 3-ureidopropyltrialkoxysilane, 3-chloropropyltrialkoxysilane, bis (trialkoxy) Rirupuropiru) tetrasulfide, 3-isocyanate propyl trialkoxysilane can be exemplified. These can be used alone or in combination of two or more.

  As described above, the coating composition of the present invention can be applied to the metal member and the plastic member surface.

  Examples of the metal member include iron, aluminum, brass, copper, tinplate, stainless steel, galvanized steel, and zinc alloy (eg, Zn—Al, Zn—Ni, Zn—Fe, etc.) plated steel.

  The metal member may have a surface subjected to a surface treatment such as a phosphate treatment, a chromate treatment, or a complex oxide treatment, and an undercoat film is formed on the surface of the metal member. May be. Examples of the undercoat paint include electrodeposition paints, and among them, cationic electrodeposition paints are preferable.

  As the plastic member, for example, a polyolefin obtained by (co) polymerizing one or two or more of olefins having 2 to 10 carbon atoms such as ethylene, propylene, butylene, and hexene is particularly suitable. , Polycarbonate, ABS resin, urethane resin, polyamide and the like. Examples of molded articles made of these plastic substrates include automobile outer plate parts such as bumpers, spoilers, grills, and fenders; and home appliance outer plate parts. Prior to the coating of the coating composition of the present invention, these plastic molded products can be appropriately subjected to degreasing treatment, washing treatment, etc. by a method known per se.

  The metal member and the plastic member can be assembled by a known method.

  The coating of the coating composition of the present invention is performed by air spraying, airless spraying, dip coating, brushing on the metal member and plastic member surface so that the dry film thickness is usually in the range of 1 to 20 μm, preferably 3 to 15 μm. It is suitable to carry out using etc. After coating of the composition, the obtained coating surface can be set at room temperature for about 30 seconds to 60 minutes, if necessary, or preheated at a temperature of about 40 to about 80 ° C. for about 1 to 60 minutes ( Can be preheated), or can be cured by heating at a temperature of about 60 to about 140 ° C., preferably about 70 to about 120 ° C. for about 20 to 40 minutes. It is possible to perform the top coating of the next step without preheating after coating the coating composition. After coating the coating composition of the present invention, the coating composition is set at room temperature (about 20 to about 35 ° C.) for about 30 seconds to 10 minutes. Is preferred.

  In the present invention, the top coating material can be applied to the coating surface of the coating composition of the present invention. As the top coating, a colored coating or a clear coating may be used alone, or the base coating and the clear coating may be sequentially applied using the colored coating as a base coating. In addition, as a colored base coating layer, for example, a white base coating and an interference pearl base coating may be sequentially applied on the coating by the coating composition of the present invention to form a multilayer film.

  As the colored paint, those known per se can be used. Usually, an organic solvent and / or water as a main solvent, a colored component such as a colored pigment, a bright pigment and a dye, a base resin, a crosslinking agent, etc. The thing containing the resin component of this can be used.

  Examples of the base resin used in the colored paint include resins such as acrylic resins, polyester resins, and alkyd resins having reactive functional groups such as hydroxyl groups, epoxy groups, carboxyl groups, and silanol groups. . Examples of the crosslinking agent include amino resins such as melamine resins and urea resins, (block) polyisocyanates, polyepoxides, polycarboxylic acids, and the like having a reactive functional group capable of reacting with the functional group.

  The colored paint contains paint additives such as extender pigments, curing catalysts, UV absorbers, coating surface conditioners, rheology control agents, antioxidants, antifoaming agents, waxes, and preservatives as necessary. be able to.

  The colored paint is a dry film thickness on the coating film of the present uncured or cured present paint composition, usually 5 to 50 μm, preferably 5 to 30 μm, more preferably 10 to 20 μm. The coating surface to be obtained can be set at room temperature for about 1 to 60 minutes, if necessary, or preheated at a temperature of about 40 to about 80 ° C. for about 1 to 60 minutes, Alternatively, it can be cured by heating at a temperature of about 60 to about 140 ° C., preferably about 80 to about 120 ° C. for about 20 to 40 minutes. In the present invention, it is particularly preferable to perform clear coating without curing the colored base paint after coating.

  Examples of the clear paint include a resin component such as a base resin and a crosslinking agent, an organic solvent, water, and the like. Further, if necessary, an ultraviolet absorber, a light stabilizer, a curing catalyst, a coating surface conditioner, An organic solvent-based or water-based thermosetting paint that contains paint additives such as rheology control agents, antioxidants, antifoaming agents, and waxes. It is possible to use one having transparency to the extent that it can be performed.

  Examples of the base resin include acrylic resin, polyester resin, alkyd resin, fluororesin, urethane resin, and silicon-containing resin containing at least one reactive functional group such as a hydroxyl group, a carboxyl group, a silanol group, and an epoxy group. In particular, a hydroxyl group-containing acrylic resin is suitable. As said crosslinking agent, it has a reactive functional group which can react with these functional groups, melamine resin, urea resin, (block) polyisocyanate compound, epoxy compound, carboxyl group-containing compound, acid anhydride, alkoxysilane group-containing Examples of the compound include polyisocyanate compounds.

  The clear coating is applied on an uncured or cured colored base coating so that the dry film thickness is usually within the range of 10 to 50 μm, preferably 20 to 40 μm. If necessary, the surface is set at room temperature for about 1 to 60 minutes, or preheated at a temperature of about 40 to about 80 ° C. for about 1 to 60 minutes, and then about 60 to about 140 ° C., preferably about 70 to It can be carried out by heating and curing at a temperature of about 120 ° C. for about 20 to 40 minutes.

  According to the coating composition of the present invention, it is possible to form a coating film having excellent chipping resistance, adhesion, finish, and gasohol property for metal members and plastic members without using a primer coating. This is presumably because the block copolymer (I) contributes as a component for improving the compatibility between the component contributing to adhesion to the metal member and the component contributing to adhesion to the plastic member. That is, the polymer block (B) in the block copolymer (I) has an affinity for the highly polar component considered to contribute to the adhesion to the metal member, while the adhesion to the plastic member. Since the polymer block (A) in the block copolymer (I) has an affinity for the low polar component that is thought to contribute to the compatibility, the compatibility between the high polar component and the low polar component is improved. And it is guessed that the coating film which is excellent in the adhesiveness and finishing property to both members is obtained.

  Since the coating composition of this invention has the outstanding adhesiveness with respect to a metal member and a plastic member, it is guessed that the coating film which is excellent in chipping resistance and gasohol property is obtained. Moreover, since the coating composition of this invention is excellent in various coating film performances as mentioned above with respect to a metal member and a plastic member, it is possible to apply simultaneously after assembling both members.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to only these examples. “Part” and “%” are based on mass. Moreover, the film thickness of a coating film is based on a cured coating film.

Production Example 1 of Block Copolymer (I)
Charge 10 parts of “Swazol 1000” (manufactured by Maruzen Petrochemical Co., Ltd., hydrocarbon solvent) and 2 parts of 2,4-diphenyl-4-methyl-1-pentene to the flask and raise the temperature to 155 ° C. under a nitrogen stream. did. To this, 6 parts glycidyl methacrylate, 14 parts 2-ethylhexyl methacrylate, 5 parts lauryl methacrylate, 4 parts isobornyl methacrylate, 1 part 2-ethylhexyl acrylate, 1.5 parts di-t-amyl peroxide, and "Swazole 1000" 10 parts of the mixture was added dropwise to obtain a solution of the polymer block (A). The weight average molecular weight was about 3,000. Next, this solution is kept at 90 ° C., and 15 parts of 2-hydroxyethyl methacrylate, 5 parts of 2-hydroxyethyl acrylate, 45 parts of 2-ethylhexyl methacrylate, 2 parts of lauryl methacrylate, 2 parts of isobornyl methacrylate, 2-ethylhexyl A mixed liquid of 1 part of acrylate, 1 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 20 parts of isobutyl acetate was added dropwise, and 2,2′-azobis (2,4-dimethylvaleronitrile) 0 was further added. .5 parts was added to produce a polymer block (B) to obtain a solution (I-1) containing an AB type block copolymer. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 0.8.

Production Example 2
10 parts of “Swazole 1000” and 2 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 155 ° C. under a nitrogen stream. To this, a mixture of 20 parts of glycidyl methacrylate, 1 part of isobornyl methacrylate, 8 parts of stearyl methacrylate, 1 part of cyclohexyl methacrylate, 1.4 parts of di-t-amyl peroxide, and 10 parts of dipropylene glycol dimethyl ether was added dropwise. A solution of the combined block (A) was obtained. The weight average molecular weight was about 3,000. Next, this solution is kept at 90 ° C., and 20 parts of 2-hydroxyethyl methacrylate, 0.1 part of methacrylic acid, 39 parts of 2-ethylhexyl methacrylate, 9.9 parts of isobornyl methacrylate, 1 part of styrene, 2, 2 A mixed solution of 0.9 part of '-azobis (2,4-dimethylvaleronitrile) and 20 parts of isobutyl acetate was added dropwise, and 0.5 part of 2,2'-azobis (2,4-dimethylvaleronitrile) was further added. Then, a polymer block (B) was produced, and a solution (I-2) containing an AB type block copolymer was obtained. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 0.4.

Production Example 3
10 parts of “Swazole 1000” and 2.2 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 155 ° C. under a nitrogen stream. To this, a mixture of 5 parts of glycidyl methacrylate, 25 parts of lauryl methacrylate, 19 parts of isobornyl methacrylate, 1 part of isobutyl methacrylate, 1.3 parts of di-t-amyl peroxide and 10 parts of “Swazole 1000” was added dropwise. A solution of the combined block (A) was obtained. The weight average molecular weight was about 4,000. Next, this solution is kept at 90 ° C., 14 parts of 2-hydroxyethyl methacrylate, 4 parts of 2-hydroxyethyl acrylate, 0.1 part of 2- (dimethylamino) ethyl methacrylate, 19 parts of 2-ethylhexyl methacrylate, lauryl methacrylate 2.9 parts, 10 parts of cyclohexyl methacrylate, 1 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 20 parts of isobutyl acetate were added dropwise, and 2,2′-azobis (2,4 -Dimethylvaleronitrile) 0.5 part was added, the polymer block (B) was produced | generated, and the solution (I-3) containing an AB type block copolymer was obtained. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 1.3.

Production Example 4
10 parts of “Swazole 1000” and 2 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 155 ° C. under a nitrogen stream. To this, 9 parts glycidyl methacrylate, 2 parts 3,4-epoxycyclohexylmethyl methacrylate, 1 part 2-ethylhexyl methacrylate, 17 parts lauryl methacrylate, 1 part isobornyl methacrylate, 1.5 parts di-t-amyl peroxide, and A mixture of 10 parts of dipropylene glycol dimethyl ether was added dropwise to obtain a polymer block (A) solution. The weight average molecular weight was about 3,000. Next, this solution is kept at 115 ° C., 1 part 2-hydroxyethyl methacrylate, 6 parts 2-hydroxyethyl acrylate, 25 parts 2-ethylhexyl methacrylate, 11 parts isobornyl methacrylate, 2 parts 2-ethylhexyl acrylate, isobutyl A mixed solution of 15 parts of methacrylate, 10 parts of cyclohexyl methacrylate, 1 part of t-butyl-peroxy-2-ethylhexanoate and 20 parts of isobutyl acetate is added dropwise, and 2,2′-azobis (2,4-dimethylvaleronitrile is further added. ) 0.5 part was added to produce a polymer block (B) to obtain a solution (I-4) containing an AB type block copolymer. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 0.4.

Production Example 5
10 parts of “Swazole 1000” and 6.5 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask, and the temperature was raised to 140 ° C. under a nitrogen stream. To this, a mixture of 16.5 parts of glycidyl methacrylate, 3 parts of 2-ethylhexyl methacrylate, 30 parts of lauryl methacrylate, 3 parts of t-butyl-peroxy-2-ethylhexanoate and 10 parts of “Swazole 1000” was dropped. A solution of polymer block (A) was obtained. The weight average molecular weight was about 3,000. Next, this solution is kept at 90 ° C., 14 parts of 2-hydroxyethyl methacrylate, 31 parts of 2-ethylhexyl methacrylate, 5.5 parts of isobutyl methacrylate, 2,2′-azobis (2,4-dimethylvaleronitrile) 1 A mixture of 20 parts of isobutyl acetate and 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is added to form a polymer block (B), which is AB type. A solution (I-5) containing a block copolymer was obtained. The weight average molecular weight was about 6,000, and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 0.7.

Production Example 6 (for comparative example)
10 parts of “Swazole 1000” and 2 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 155 ° C. under a nitrogen stream. To this 0.3 parts glycidyl methacrylate, 14 parts 2-ethylhexyl methacrylate, 10.7 parts lauryl methacrylate, 4 parts isobornyl methacrylate, 1 part 2-ethylhexyl acrylate, 1.5 parts di-t-amyl peroxide, and A mixture of 10 parts of dipropylene glycol dimethyl ether was dropped to obtain a solution of the polymer block (A). The weight average molecular weight was about 3,000. Next, this solution is kept at 90 ° C., and 15 parts of 2-hydroxyethyl methacrylate, 5 parts of 2-hydroxyethyl acrylate, 45 parts of 2-ethylhexyl methacrylate, 2 parts of lauryl methacrylate, 2 parts of isobornyl methacrylate, 2-ethylhexyl A mixed liquid of 1 part of acrylate, 1 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 20 parts of isobutyl acetate was added dropwise, and 2,2′-azobis (2,4-dimethylvaleronitrile) 0 was further added. .5 parts was added to produce a polymer block (B) to obtain a solution (I-6) containing an AB type block copolymer. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 1.0.

Production Example 7 (for comparative example)
10 parts of “Swazole 1000” and 6.5 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask, and the temperature was raised to 140 ° C. under a nitrogen stream. A mixture of 3 parts of 2-ethylhexyl methacrylate, 46.5 parts of lauryl methacrylate, 3 parts of t-butyl-peroxy-2-ethylhexanoate, and 10 parts of ethylene glycol monobutyl ether was added dropwise to the polymer block ( A solution of A) was obtained. The weight average molecular weight was about 3,000. Next, this solution is kept at 90 ° C., and 35 parts of 2-hydroxyethyl methacrylate, 10 parts of 2-ethylhexyl methacrylate, 5.5 parts of isobutyl methacrylate, 2,2′-azobis (2,4-dimethylvaleronitrile) 1 A mixture of 20 parts of ethylene glycol monobutyl ether is added dropwise, and 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is further added to form a polymer block (B). A solution (I-7) containing a B-type block copolymer was obtained. The weight average molecular weight was about 6000, and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 2.4.

Production Example 8 (for comparative example)
10 parts of “Swazole 1000” and 2 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 155 ° C. under a nitrogen stream. To this, a mixture of 5 parts of glycidyl methacrylate, 11 parts of 2-ethylhexyl methacrylate, 14 parts of lauryl methacrylate, 1.5 parts of di-t-amyl peroxide, and 10 parts of dipropylene glycol dimethyl ether was dropped to form a polymer block (A ) Was obtained. The weight average molecular weight was about 3000. Next, this solution was kept at 90 ° C., and 1 part of 2-hydroxyethyl methacrylate, 50 parts of 2-ethylhexyl methacrylate, 19 parts of isobutyl methacrylate, 1 part of 2,2′-azobis (2,4-dimethylvaleronitrile), A mixed solution of 20 parts of isobutyl acetate was added dropwise, and 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) was further added to form a polymer block (B). A solution (I-8) containing a polymer was obtained. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 0.1.

Production Example 9
10 parts of dipropylene glycol dimethyl ether and 6 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 140 ° C. under a nitrogen stream. To this, 15 parts of 2-hydroxyethyl methacrylate, 0.1 part of methacrylic acid, 20 parts of 2-ethylhexyl methacrylate, 1.9 parts of lauryl methacrylate, 10 parts of isobornyl methacrylate, 3 parts of 2-ethylhexyl acrylate, t-butyl- A mixture of 3 parts of peroxy-2-ethylhexanoate, 5 parts of “Swazole 1000” and 5 parts of ethylene glycol monobutyl ether was added dropwise to obtain a polymer block (B) solution. The weight average molecular weight was about 6,000. Next, this solution is kept at 90 ° C., and 18 parts of glycidyl methacrylate, 5 parts of 2-ethylhexyl methacrylate, 26 parts of lauryl methacrylate, 1 part of styrene, 1 part of 2,2′-azobis (2,4-dimethylvaleronitrile) Then, a mixed solution of 20 parts of isobutyl acetate was added dropwise, and 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) was further added to form a polymer block (A). A solution (I-9) containing a copolymer was obtained. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 0.6.

Production Example 10 (for comparative example)
10 parts of dipropylene glycol dimethyl ether and 6 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 140 ° C. under a nitrogen stream. To this, 15 parts of 2-hydroxyethyl methacrylate, 0.1 part of methacrylic acid, 20 parts of 2-ethylhexyl methacrylate, 1.9 parts of lauryl methacrylate, 10 parts of isobornyl methacrylate, 3 parts of 2-ethylhexyl acrylate, t-butyl- A mixture of 3 parts of peroxy-2-ethylhexanoate, 5 parts of “Swazole 1000” and 5 parts of ethylene glycol monobutyl ether was added dropwise to obtain a polymer block (B) solution. The weight average molecular weight was about 6000. Next, this solution is kept at 90 ° C., and a mixed solution of 5 parts of 2-ethylhexyl methacrylate, 45 parts of lauryl methacrylate, 1 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 20 parts of isobutyl acetate is added. Then, 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is further added to form a polymer block (A), and a solution containing an AB type block copolymer (I— 10) was obtained. The weight average molecular weight was about 10,000 and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA) was 1.2.

Production Example 11
10 parts of “Swasol 1000” and 6 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask, and the temperature was raised to 140 ° C. under a nitrogen stream. To this, 10 parts glycidyl methacrylate, 10 parts 2-ethylhexyl methacrylate, 8 parts lauryl methacrylate, 2 parts isobornyl methacrylate, 3 parts t-butyl-peroxy-2-ethylhexanoate, and 10 parts dipropylene glycol dimethyl ether The mixture was added dropwise to obtain a polymer block (A1) solution. The weight average molecular weight was about 3,000. Next, this solution is kept at 115 ° C., and 18 parts of 2-hydroxyethyl methacrylate, 2 parts of 2-hydroxyethyl acrylate, 40 parts of 2-ethylhexyl methacrylate, 7 parts of isobutyl methacrylate, 3 parts of cyclohexyl methacrylate, t-butyl-peroxy A mixture of 1 part of 2-ethylhexanoate and 20 parts of isobutyl acetate was added dropwise, and 0.3 part of 2,2′-azobis (2,4-dimethylvaleronitrile) was further added to form a polymer block (B). To obtain a solution containing an AB type block copolymer. The weight average molecular weight was about 10,000. To this, 18 parts of glycidyl methacrylate, 4 parts of 2-ethylhexyl methacrylate, 7 parts of isobornyl methacrylate, 1 part of cyclohexyl methacrylate, 0.5 part of t-butyl-peroxy-2-ethylhexanoate and 13 parts of "Swazole 1000" Then, 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is further added to form a polymer block (A2) and a solution containing an AB-A type block copolymer. (I-11) was obtained. The weight average molecular weight was about 130,000 and the solid content was about 70%. The solubility parameter value (SPA1) derived from the monomer composition constituting the polymer block (A1) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA1) is 0.7, which constitutes the polymer block (B) with the solubility parameter value (SPA2) derived from the monomer composition constituting the polymer block (A2). The difference (SPB-SPA2) in solubility parameter values (SPB) derived from the monomer composition was 0.4.

Production Example 12 (for comparative example)
10 parts of “Swasol 1000” and 6 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask, and the temperature was raised to 140 ° C. under a nitrogen stream. To this was added dropwise a mixture of 10 parts 2-ethylhexyl methacrylate, 18 parts lauryl methacrylate, 2 parts isobornyl methacrylate, 3 parts t-butyl-peroxy-2-ethylhexanoate, and 10 parts dipropylene glycol dimethyl ether. A solution of the polymer block (A1) was obtained. The weight average molecular weight was about 3,000. Next, this solution is kept at 115 ° C., and 18 parts of 2-hydroxyethyl methacrylate, 2 parts of 2-hydroxyethyl acrylate, 40 parts of 2-ethylhexyl methacrylate, 7 parts of isobutyl methacrylate, 3 parts of cyclohexyl methacrylate, t-butyl-peroxy A mixture of 1 part of 2-ethylhexanoate and 20 parts of isobutyl acetate was added dropwise, and 0.3 part of 2,2′-azobis (2,4-dimethylvaleronitrile) was further added to form a polymer block (B). To obtain a solution containing an AB type block copolymer. The weight average molecular weight was about 10,000. To this, a mixture of 22 parts of 2-ethylhexyl methacrylate, 7 parts of isobornyl methacrylate, 1 part of cyclohexyl methacrylate, 0.5 part of t-butyl-peroxy-2-ethylhexanoate and 13 parts of “Swazole 1000” was added dropwise. Further, 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is added to form a polymer block (A2), and a solution containing an ABA type block copolymer (I— 12) was obtained. The weight average molecular weight was about 13,000 and the solid content was about 70%. The solubility parameter value (SPA1) derived from the monomer composition constituting the polymer block (A1) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The difference (SPB-SPA1) is 1.1, and constitutes the solubility parameter value (SPA2) derived from the monomer composition constituting the polymer block (A2) and the polymer block (B). The difference in the solubility parameter value (SPB) derived from the monomer composition (SPB-SPA2) was 1.0.

Production Example 13
10 parts of dipropylene glycol dimethyl ether and 4 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 140 ° C. under a nitrogen stream. To this is a mixture of 9 parts 2-hydroxyethyl methacrylate, 20 parts 2-ethylhexyl methacrylate, 1 part cyclohexyl methacrylate, 1.8 parts t-butyl-peroxy-2-ethylhexanoate, and 10 parts "Swazole 1000". The solution was added dropwise to obtain a polymer block (B1) solution. The weight average molecular weight was about 4,000. Next, this solution was kept at 115 ° C., and mixed with 17 parts of glycidyl methacrylate, 3 parts of 2-ethylhexyl methacrylate, 30 parts of lauryl methacrylate, 1 part of t-butyl-peroxy-2-ethylhexanoate and 20 parts of isobutyl acetate. The solution is added dropwise, and further 0.3 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is added to produce a polymer block (A) to obtain a solution containing a B-A type block copolymer. It was. The weight average molecular weight was about 8,000. To this, a mixture of 9 parts 2-hydroxyethyl methacrylate, 11 parts 2-ethylhexyl methacrylate, 10 parts isobutyl methacrylate, 0.5 parts t-butyl-peroxy-2-ethylhexanoate, and 13 parts "Swazole 1000" Further, 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is added to form a polymer block (B2) and a solution containing a B-A-B type block copolymer ( I-13) was obtained. The weight average molecular weight was about 12,000, and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB1) derived from the monomer composition constituting the polymer block (B1) The difference (SPB1-SPA) is 0.8, and constitutes the solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the polymer block (B2). The difference (SPB2-SPA) in solubility parameter values (SPB2) derived from the monomer composition was 0.9.

Production Example 14 (for comparative example)
10 parts of dipropylene glycol dimethyl ether and 4 parts of 2,4-diphenyl-4-methyl-1-pentene were charged into a flask and heated to 140 ° C. under a nitrogen stream. To this is a mixture of 21 parts 2-hydroxyethyl methacrylate, 8 parts 2-ethylhexyl methacrylate, 1 part cyclohexyl methacrylate, 1.8 parts t-butyl-peroxy-2-ethylhexanoate and 10 parts ethylene glycol monobutyl ether. Was dropped to obtain a polymer block (B1) solution. The weight average molecular weight was about 4,000. Next, this solution was kept at 115 ° C., and mixed with 17 parts of glycidyl methacrylate, 3 parts of 2-ethylhexyl methacrylate, 30 parts of lauryl methacrylate, 1 part of t-butyl-peroxy-2-ethylhexanoate and 20 parts of isobutyl acetate. The solution is added dropwise, and further 0.3 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is added to produce a polymer block (A) to obtain a solution containing a B-A type block copolymer. It was. The weight average molecular weight was about 8,000. To this, a mixture of 16 parts 2-hydroxyethyl methacrylate, 11 parts 2-ethylhexyl methacrylate, 3 parts isobutyl methacrylate, 0.5 part t-butyl-peroxy-2-ethylhexanoate, and 13 parts ethylene glycol monobutyl ether. Further, 0.5 part of 2,2′-azobis (2,4-dimethylvaleronitrile) is added to form a polymer block (B2) and a solution containing a B-A-B type block copolymer ( I-14) was obtained. The weight average molecular weight was about 12,000, and the solid content was about 70%. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB1) derived from the monomer composition constituting the polymer block (B1) The difference (SPB1-SPA) is 2.1, and constitutes a solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the polymer block (B2). The difference (SPB2-SPA) in solubility parameter values (SPB2) derived from the monomer composition was 1.5.

Production and production example 15 of hydroxyl group-containing urethane resin (II)
In a four-necked reaction vessel equipped with a thermometer, thermostat, stirring device, reflux condenser, nitrogen inlet tube and dropping device, “PLACCEL-M” (trade name, manufactured by Daicel Chemical Industries, ε-caprolactone) 456 parts , 261 parts of tris (2-hydroxyethyl) isocyanurate and 0.03 part of tetrabutyl titanate were charged and heated to 160 ° C. while stirring. The reaction was carried out at the same temperature for about 4 hours to obtain a modified ε-caprolactone of tris (2-hydroxyethyl) isocyanurate.

Production Example 16
In a four-necked reaction vessel equipped with a thermometer, thermostat, stirring device, reflux condenser, nitrogen inlet tube and dropping device, 243 parts of methyl isobutyl ketone, 20 parts of tris (2-hydroxyethyl) isocyanurate (molecular weight 261) "PTMG-1000" (trade name, manufactured by Mitsubishi Chemical Corporation, polytetramethylene ether glycol, number average molecular weight 1,000, hydroxyl value 112 mg KOH / g) 102 parts, N-methyl-2-pyrrolidone 24 parts and dibutyltin dilaurate 0.016 part was charged and heated to 110 ° C. while stirring. Subsequently, 40 parts of methylenebis (1,4-cyclohexanediyl) diisocyanate was added while maintaining the temperature of the liquid at 110 ° C., and the reaction was continued until the isocyanate value became 1.0 mg NCO / g or less based on the resin solid content. Next, 111 parts of methyl isobutyl ketone was added to obtain a hydroxyl group-containing urethane resin solution (II-1) having a solid content of 30%. The obtained hydroxyl group-containing urethane resin had a hydroxyl value of 45 mgKOH / g, a weight average molecular weight of 20,000, and a number average molecular weight of 6,000.

Moreover, content rate C _a1 of the cyclic polyol compound (a1) having a nurate structure with respect to the total amount of the polyol component (a) in the obtained hydroxyl group-containing urethane resin was calculated as follows.

Number of moles of cyclic polyol compound (a1) having a nurate structure = 20/261 (tris (2-hydroxyethyl) isocyanurate)
≒ 0.0766 [mol]
Number of moles of polyol component (a) = 20/261 (tris (2-hydroxyethyl) isocyanurate) +102/1000 (“PTMG-1000”)
≒ 0.0766 + 0.102
= 0.1786 [mol]
Content ratio C _{a1 of the} cyclic polyol compound (a1) having a nurate structure with respect to the total amount of the polyol component (a)
= 0.0766 / 0.1786 × 100
≒ 43 [mol%]
Moreover, content rate C _a2-1 of the diol compound (a2-1) with respect to the total amount of the polyol component (a) in the obtained hydroxyl group-containing urethane resin was calculated as follows.

Total number of moles of diol compound (a2-1) = 102/1000 (“PTMG-1000”)
= 0.102 [mol]
Content ratio C _a2-1 of diol compound (a2-1) with respect to the total amount of polyol component (a)
= 0.102 / 0.1786 × 100
≒ 57 [mol%]
Moreover, ratio C _a1 / C _a2-1 of said C _a1 and C _a2-1 of the obtained hydroxyl-containing urethane resin was _43/57 from said calculation value.

Production Example 17
In a four-necked reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser, nitrogen inlet tube and dropping device, 243 parts of methyl isobutyl ketone, tris (2-hydroxyethyl) isocyanurate obtained in Production Example 15 Ε-caprolactone modified product of 55 parts, “PTMG-1000” (trade name, manufactured by Mitsubishi Chemical Corporation, polytetramethylene ether glycol, number average molecular weight 1,000, hydroxyl value 112 mg KOH / g) 102 parts, N-methyl-2 -30 parts of pyrrolidone and 0.020 part of dibutyltin dilaurate were charged and heated to 110 ° C while stirring. Subsequently, 40 parts of methylenebis (1,4-cyclohexanediyl) diisocyanate was added while maintaining the temperature of the liquid at 110 ° C., and the reaction was continued until the isocyanate value became 1.0 mg NCO / g or less based on the resin solid content. Subsequently, 135 parts of methyl isobutyl ketone was added to obtain a hydroxyl group-containing urethane resin solution (II-2) having a solid content of 30%. The obtained hydroxyl group-containing urethane resin had a hydroxyl value of 42 mgKOH / g, a weight average molecular weight of 25,000, and a number average molecular weight of 6,000.

In addition, C _a1 of the obtained hydroxyl group-containing urethane resin was 43, and C _a2-1 was 57.

Production Example 18
In a four-necked reaction vessel equipped with a thermometer, thermostat, stirring device, reflux condenser, nitrogen inlet tube and dropping device, 243 parts of methyl isobutyl ketone, 11 parts of 1,4-cyclohexanedimethanol (molecular weight 144), “ PTMG-1000 "(trade name, manufactured by Mitsubishi Chemical Corporation, polytetramethylene ether glycol, number average molecular weight 1,000, hydroxyl value 112 mg KOH / g) 102 parts, N-methyl-2-pyrrolidone 23 parts and dibutyltin dilaurate 015 parts were charged and heated to 110 ° C. with stirring. Subsequently, 40 parts of methylenebis (1,4-cyclohexanediyl) diisocyanate was added while maintaining the temperature of the liquid at 110 ° C., and the reaction was continued until the isocyanate value became 1.0 mg NCO / g or less based on the resin solid content. Next, 105 parts of methyl isobutyl ketone was added to obtain a hydroxyl group-containing urethane resin solution (II-3) having a solid content of 30%. The obtained hydroxyl group-containing urethane resin had a hydroxyl value of 20 mg KOH / g, a weight average molecular weight of 12,000, and a number average molecular weight of 4,000.

Moreover, C _a1 of the obtained hydroxyl group-containing urethane resin was 0, and C _a2-1 was 100.

Production Example 19
In a four-necked reaction vessel equipped with a thermometer, thermostat, stirring device, reflux condenser, nitrogen inlet tube and dropping device, 243 parts of methyl isobutyl ketone, “PTMG-1000” (trade name, manufactured by Mitsubishi Chemical Corporation, Poly Tetramethylene ether glycol, number average molecular weight 1,000, hydroxyl value 112 mg KOH / g) 133.9 parts, N-methyl-2-pyrrolidone 24 parts and dibutyltin dilaurate 0.016 parts were charged and heated to 110 ° C. with stirring. The temperature rose. Next, 28.1 parts of methylenebis (1,4-cyclohexanediyl) diisocyanate is added while maintaining the temperature of the liquid at 110 ° C., and the reaction is continued until the isocyanate value becomes 1.0 mg NCO / g or less based on the resin solid content. It was.
Subsequently, 111 parts of methyl isobutyl ketone was added to obtain a hydroxyl group-containing urethane resin solution (II-4) having a solid content of 30%. The obtained hydroxyl group-containing urethane resin had a hydroxyl value of 18.6 mgKOH / g, a weight average molecular weight of 17,000, and a number average molecular weight of 6,000.

  Of the hydroxyl group-containing urethane resin solutions (II-1) to (II-4), (II-1) and (II-2) correspond to the hydroxyl group-containing urethane resin (U) having a nurate structure.

Production Example 20 of Curing Agent (IV) 20
In a flask, 142 parts of “Duranate TPA-100”, 60 parts of toluene and 140 parts of dibutyl malonate were added. While stirring, 1.3 parts of a 28% methanol solution of sodium methoxide was added and reacted at 70 ° C. for 10 hours. It was. Thereafter, 63 parts of 1-butanol was added and aged at 70 ° C. to obtain a solution of a blocked polyisocyanate curing agent (IV-1).

Production Example 21
In a flask, 142 parts of “Duranate TPA-100” (manufactured by Asahi Kasei Chemicals Co., Ltd., polyisocyanate, isocyanate content 23%) was charged, and while stirring, 76 parts of 3,5-dimethylpyrazole was added little by little. The reaction was performed at 110 ° C. Thereafter, 47 parts of 1-butanol and 50 parts of toluene were added, and it was confirmed that the reaction rate of the isocyanate group was 99% or more, and a solution of a blocked polyisocyanate curing agent (IV-2) was obtained.

Production Production Example 22 of Hydroxyl-Containing Polyester Resin 22
Into the flask, 218 parts of neopentyl glycol, 222 parts of 2-ethyl-2-butyl-1,3-propanediol, 158 parts of trimethylolpropane, 135 parts of adipic acid, 498 parts of hexahydrophthalic anhydride, 240 ° C. After dehydrating and condensing, 61 parts of trimellitic anhydride is added and reacted, and 120 parts of propylene glycol monopropyl ether and 300 parts of propylene glycol monomethyl ether are further added to obtain a solution (VI-1) containing a hydroxyl group-containing polyester resin. It was. The hydroxyl value of the hydroxyl group-containing polyester resin was about 80 mgKOH / g, the acid value was about 30 mgKOH / g, and the number average molecular weight was about 2,500.

Production Example 23
In a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and water separator, 52.6 parts (0.36 mol) of adipic acid (molecular weight 146), 1,2-cyclohexanedicarboxylic acid anhydride (molecular weight 154) ) 20.8 parts (0.135 mol), 1,4-cyclohexanedicarboxylic acid (molecular weight 172) 23.2 parts (0.135 mol), isophthalic acid (molecular weight 166) 44.8 parts (0.27 mol), trimethylol After 33.5 parts (0.25 mol) of propane (molecular weight 134) and 78 parts (0.0.75 mol) of neopentyl glycol (molecular weight 104) were charged and heated from 160 ° C. to 230 ° C. over 3 hours, While condensing water was distilled off with a water separator, it was kept at 230 ° C. and reacted until the acid value reached 5 mgKOH / g. Next, dilute with a mixed solvent of xylene / "Swazole 1000" (trade name, manufactured by Maruzen Petrochemical Co., Ltd., petroleum aromatic hydrocarbon solvent) = 50/50 (mass ratio) to a solid content concentration of 60%, A hydroxyl group-containing polyester resin solution (VI-2) was obtained. The obtained hydroxyl group-containing polyester resin had a hydroxyl value of 118 and a number average molecular weight of 1,870.
Preparation Example 1 of Coating Composition
20 parts (solid content) of a block copolymer (I-1), 20 parts (solid content) of a hydroxyl group-containing urethane resin (II-1), 35 parts (solid content) of "Super Clon 892L" (Note 1), a curing agent (IV-1) 10 parts (solid content), "Denacol EX-252" (Note 3) 5 parts, hydroxyl group-containing polyester resin (VI-1) 10 parts, and "Vulcan XC-72" (Note 5) 20 parts Was mixed with a mixed solvent of xylene / toluene = 1/1 to obtain a coating composition (1) having a viscosity of 13 seconds / Ford Cup # 4/20 ° C.

Examples 2-17 and Comparative Examples 1-12
The coating compositions (2) to (29) were obtained in the same manner as in Example 1 except that the composition was as shown in Table 1 in Example 1.

In addition, the mixing | blending of Table 1 is a solid content display, (Note 1)-(Note 5) in Table 1 are as follows.
(Note 1) Supercron 892L: trade name, manufactured by Nippon Paper Chemicals, maleic anhydride-modified chlorinated polypropylene, chlorination rate 22%, solid content 20%
(Note 2) Unistor P-401: Trade name, manufactured by Mitsui Chemicals, non-chlorine modified polyolefin, solid content 8%
(Note 3) Denacol EX-252: trade name, manufactured by Nagase ChemteX Corporation, hydrogenated bisphenol A type epoxy resin, epoxy equivalent 213)
(Note 4) Cymel 327: Product name, manufactured by Nippon Cytec Industries, Inc., melamine resin, solid content 90%
(Note 5) Vulcan XC-72: trade name, manufactured by Cabot Specialty Chemicals, conductive carbon black
As a metal member for producing a test coated plate, a zinc phosphate-treated cold rolled steel sheet (450 mm × 300 mm × 0.8 mm), a thermosetting epoxy resin-based cationic electrodeposition coating composition (trade name “Electron GT-10”, Kansai Paint Co., Ltd.) was electrodeposited to a film thickness of 20 μm and cured by heating at 170 ° C. for 30 minutes.

  As a plastic member, “TSOP-1 (TC-6)” (trade name, manufactured by Nippon Polychem, 350 mm × 10 mm × 2 mm) was prepared.

  The surfaces of the metal member and the plastic member were degreased by wiping with gauze containing petroleum benzine. A steel plate and a polypropylene plate obtained as described above were arranged adjacent to each other to obtain a test plate.

The coating compositions (1) to (29) prepared above were spray-coated on the test plate so as to have a dry film thickness of 10 μm, set at room temperature for 3 minutes, and then “WBC-713T” as a colored base coating. # 1F7 "(trade name, manufactured by Kansai Paint Co., Ltd., acrylic / melamine resin-based water-based base coat paint, silver coating color) was electrostatically applied to a dry film thickness of 15 μm.
Next, “Soflex # 500 clear” (trade name, acrylic urethane organic solvent-type clear paint manufactured by Kansai Paint Co., Ltd.) is applied as a clear paint so as to have a dry film thickness of 30 μm. After being left for a minute, it was heated in an oven at 95 ° C. for 30 minutes to obtain a test coating plate on which a multilayer coating film was formed. Various coating film performance tests described below were conducted on the multilayer coating film.

Coating film performance test finish: Evaluated using W4 value measured by “Wave Scan DOI” (trade name, manufactured by BYK Gardner). The smaller the W4 value, the higher the clearness of the coating surface.
A: W4 value is less than 10.0 B: W4 value is 10.0 to 20.0
X: W4 value exceeds 20.0.

Chipping resistance: A test plate is placed on a specimen holder of a stepping stone testing machine (trade name “QGR GRvelometer” (manufactured by Q Panel)), and at −20 ° C., 30 cm away from the test plate 100 g of granite crushed stone with a particle size of 6 was collided with the test plate at an angle of 90 ° by compressed air of 480 to 520 kPa, and then the obtained test plate was washed with water and dried, and a cloth adhesive tape ( Nichiban Co., Ltd.) was attached, and the tape was peeled off and evaluated based on the area where the electrodeposition surface and the base member were exposed (abbreviated as peeled area).
A: The ratio of the peeled area to the test coating plate area is less than 5%. A: The ratio of the peeling area to the test coating board area is less than 5 to 10%.

Water resistance adhesion: After immersing the test plate in warm water at 40 ° C. for 240 hours, pulling it up and drying at 20 ° C. for 12 hours, the multi-layer coating film of the test plate is cut into a grid shape with a cutter so as to reach the substrate, Make 100 2mm x 2mm gobangs. Subsequently, an adhesive cellophane tape was attached to the surface, and the remaining state of the goby eye coating after the tape was rapidly peeled off at 20 ° C. was examined, and the water resistance was evaluated according to the following criteria.
◎: 100 galvanic coatings remain, and no small chipping of the coating occurs at the edge of the cutter cut ◯: 100 galvanic coatings remain, but the coating is small at the cutting edge of the cutter Spotting occurs x: The remaining number of goby eye coatings is 99 or less.

Gasohol resistance: This will be explained for each member.
In the case of plastic parts: Each test coating is immersed in a gasoline / methanol = 90/10 weight ratio test solution at 20 ° C, and after 30 minutes have elapsed, the coating surface state of swelling and peeling is observed. evaluated.
A: No abnormality at all
○: blistering less than 3 mm in diameter or peeling occurred x: blistering larger than 3 mm in diameter, peeling occurred
For metal parts: Each test coating is immersed in a test liquid of gasoline / methanol = 90/10 weight ratio at 40 ° C., and the state of blistering and peeling after 60 minutes is observed. Evaluation was made according to the same criteria.

Claims (11)

A coating composition containing a block copolymer (I), a hydroxyl group-containing urethane resin (II), a polyolefin resin (III), a curing agent (IV), and a conductive pigment (V),
The block copolymer (I) contains a polymerizable unsaturated monomer (a1) containing an epoxy group and another polymerizable unsaturated monomer (a2) in a mass ratio of 5/95 to 100/0. A polymer block (A), a polymerizable unsaturated monomer (a3) containing at least one functional group selected from a hydroxyl group, a carboxyl group and an amino group, and another polymerizable unsaturated monomer (a4). It is a block copolymer having a weight average molecular weight of 2,000 to 500,000, including a polymer block (B) contained so as to have a mass ratio of 3/97 to 50/50. Paint composition. The coating composition according to claim 1, wherein the other polymerizable unsaturated monomer (a2) contains a (meth) acrylic acid ester having a hydrocarbon group having 8 or more carbon atoms as a part of the component. The solubility parameter value (SPA) derived from the monomer composition constituting the polymer block (A) and the solubility parameter value (SPB) derived from the monomer composition constituting the polymer block (B) The coating composition according to claim 1 or 2, wherein the difference (SPB-SPA) is 0.2 or more.   Hydroxyl group-containing urethane resin obtained by reacting a polyol component (p) composed of a cyclic polyol compound (p1) having a nurate structure and another polyol compound (p2) with a polyisocyanate compound (q), the hydroxyl group-containing urethane resin (II). The coating composition according to any one of claims 1 to 3, which is a resin (U).   The coating composition according to any one of claims 1 to 4, wherein the cyclic polyol compound (p1) having a nurate structure is tris (hydroxyalkyl) isocyanurate.   The coating composition according to any one of claims 1 to 5, wherein the curing agent (IV) is a blocked polyisocyanate compound.   The coating composition according to any one of claims 1 to 6, wherein the conductive pigment (V) is conductive carbon. Furthermore, the coating composition of any one of Claim 1 thru | or 7 containing an epoxy resin.   The coating method which coats the coating composition of any one of Claims 1-8 on the to-be-coated object containing a metal member and a plastic member.   A coating composition according to any one of claims 1 to 8 is applied onto an object to be coated containing a metal member and a plastic member, and then a colored base paint and a clear paint are successively applied to the coated surface. A painting method characterized by   A coated article obtained by the coating method according to claim 9 or 10.