JP2017190419A - Basis composition for powdery paint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a basis composition for powdery paint that imparts excellent crushability to a resin composition for powdery paint and excellent smoothness to a coating thereof.SOLUTION: A basis composition for powdery paint contains a resin having two or more segments chemically bonded, and a noncrystalline resin having a carboxyl group and/or a hydroxy group, the resin containing a segment compatible with the noncrystalline resin and a segment not compatible with the noncrystalline resin. In the basis composition for powdery paint, a weight ratio between the noncrystalline resin and the resin [noncrystalline resin/resin] is preferably 50/50-98/2.SELECTED DRAWING: None

Description

  The present invention relates to a main composition for powder coatings.

  Powder coatings are used in a wide range of fields because they have many characteristics such as being pollution-free compared to solvent-based coatings and being easy to collect and recycle.

In general, the powder coating is prepared by melt-kneading an additive such as a thermoplastic resin as a main agent, a curing agent, and a filler, and then pulverizing and classifying.
Particles that are outside the target particle size are removed in this classification process, which leads to a decrease in yield for paint resins with poor pulverization properties. Not only will be connected, it will be easy to cause fusion.
In addition, a smooth powder coating film is required for many applications. However, if an additive having a low glass transition temperature is used in order to reduce the melt viscosity of the paint, the pulverizability and blocking resistance of the paint resin are reduced. There was a problem of decline.
In order to improve this problem, a powder coating material (for example, Patent Document 1) comprising an amorphous polyester, an acrylic resin cross-linking agent, and a crystalline polyester has been studied, but it has not been satisfactory.

Japanese Patent Laid-Open No. 9-221612

  An object of the present invention is to provide a main component composition for a powder coating material that gives the resin composition for a powder coating material excellent crushability and excellent smoothness to a coating film.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention comprises a resin (A) in which two or more types of segments (a) are bonded by a chemical bond, and an amorphous resin (B) having a carboxyl group and / or a hydroxyl group. Main component composition for powder coating (X) in which (A) has a segment (a1) compatible with the amorphous resin (B) and a segment (a2) incompatible with the amorphous resin (B) It is.

The main component composition (X) for powder coatings of the present invention has the following effects.
(1) It gives excellent crushability to the resin composition for powder coatings.
(2) Excellent smoothness and curability are imparted to the coating film of the resin composition for powder coatings.

<Resin (A)>
The resin (A) in the present invention is a resin in which at least two or more types of segments are chemically bonded, and the segment (a1) compatible with the amorphous resin (B) and the amorphous resin ( It has both a segment (a2) that is incompatible with B).
In this specification, the segment (a1) that is compatible with the amorphous resin (B) is also simply referred to as the segment (a1), and the segment that is not compatible with the amorphous resin (B). (A2) is also simply referred to as segment (a2).

  In the present invention, incompatible with the amorphous resin (B) means that the amorphous resin (B) and the compound constituting each segment are mixed, and the mixture is visually observed at room temperature. It means that the whole or a part of it is cloudy.

<Segment (a1)>
The segment (a1) is not particularly limited in its chemical structure as long as it is compatible with the amorphous resin (B), and may be a segment having crystallinity or a segment having no crystallinity. From the viewpoint of grindability, a segment having crystallinity is preferred. Such a segment (a1) is composed of, for example, the following compounds such as crystalline polyester (a11), crystalline polyurethane (a12), crystalline polyurea (a13), crystalline polyamide (a14), and crystalline polyvinyl (a15). Structures to be constructed are mentioned. As a segment (a1), the structure comprised from such a compound is preferable.

Crystalline polyester (a11):
The crystalline polyester (a11) that can be used as the segment (a1) is not particularly limited as long as it is compatible with the amorphous resin (B) described later.

A preferred crystalline polyester (a11) is a polyester resin obtained by reacting a diol component (x) and a dicarboxylic acid component (y) as raw materials. If necessary, the raw material is a trivalent or higher alcohol component or a trivalent or higher valent component. These polycarboxylic acid components may be used in combination.
Examples of the diol of the diol component (x) include aliphatic diols, alkylene ether glycols having 4 to 36 carbon atoms (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); 4 to 36 alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); alkylene oxides of the above alicyclic diols (hereinafter “alkylene oxide” is abbreviated as AO) [ethylene oxide (hereinafter referred to as “AO”) , “Ethylene oxide” is abbreviated as EO, propylene oxide (hereinafter, “propylene oxide” is abbreviated as PO), butylene oxide (hereinafter, “butylene oxide” is abbreviated as BO), etc.) (Addition mole number 1-30); AO (EO, PO, BO, etc.) addition product (addition mole number 2-30) of bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); polylactone diol (polyε- Caprolactone diol and the like); polybutadiene diol and the like. Two or more of these may be used in combination.

  Among these diols, aliphatic diols are preferable from the viewpoint of compatibility. The number of carbon atoms is usually in the range of 2 to 36, and the range of 2 to 20 is preferable. Further, from the same viewpoint, a linear aliphatic diol is preferable to a branched aliphatic diol.

  Examples of the linear aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 , 8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, , 18-octadecanediol, 1,20-eicosanediol, etc., and alkylene glycols having 2 to 20 carbon atoms. Of these, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol are preferable. .

  From the viewpoint of compatibility, the content of the linear aliphatic diol is preferably 80 mol% or more, more preferably 90 mol% or more based on the diol component (x) used.

Examples of the trihydric or higher alcohol component include trihydric or higher polyols, specifically, polyols having a valence of 3 to 8 or higher.
As the polyol having a valence of 3 to 8 or more, which is used in combination with the diol component (x) as necessary, a polyhydric aliphatic alcohol (alkane having a valence of 3 to 8 or more having 3 to 36 carbon atoms) is used. Polyols and intramolecular or intermolecular dehydrates thereof such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, and polyglycerin; sugars and derivatives thereof such as sucrose and methylglucoside); trisphenols AO adduct (addition mole number 2-30) of (trisphenol PA etc.); AO adduct (addition mole number 2-30) of novolak resin (phenol novolak, cresol novolak, etc.); acrylic polyol [hydroxyethyl (meth) Copolymers of acrylate and other vinyl monomers ; And the like.

  Of these, preferred are polyhydric aliphatic alcohols having a valence of 3 to 8 or higher and AO adducts of novolac resins, and more preferred are AO adducts of novolac resins.

The crystalline polyester (a11) is selected from the group consisting of a carboxylic acid (salt) group, a sulfonic acid (salt) group, a sulfamic acid (salt) group, and a phosphoric acid (salt) group in addition to the diol component (x). A diol (x ′) having at least one functional group may be used as a structural unit.
The “acid (salt)” in the present invention means an acid or an acid salt.
A polyester resin obtained by reacting a diol component (x), a diol (x ′) having a functional group, and a dicarboxylic acid component (y) as raw materials is preferable as the crystalline polyester (a11). The diol (x ′) having a functional group may be used alone or in combination of two or more.

  Examples of the diol (x ′) having a carboxylic acid (salt) group include tartaric acid (salt), 2,2-bis (hydroxymethyl) propanoic acid (salt), and 2,2-bis (hydroxymethyl) butanoic acid (salt). And 3- [bis (2-hydroxyethyl) amino] propanoic acid (salt) and the like.

  Examples of the diol (x ′) having a sulfonic acid (salt) group include 2,2-bis (hydroxymethyl) ethanesulfonic acid (salt) and 2- [bis (2-hydroxyethyl) amino] ethanesulfonic acid (salt). And 5-sulfo-isophthalic acid-1,3-bis (2-hydroxyethyl) ester (salt) and the like.

  Examples of the diol (x ′) having a sulfamic acid (salt) group include N, N-bis (2-hydroxyethyl) sulfamic acid (salt), N, N-bis (3-hydroxypropyl) sulfamic acid (salt), Examples thereof include N, N-bis (4-hydroxybutyl) sulfamic acid (salt) and N, N-bis (2-hydroxypropyl) sulfamic acid (salt).

Examples of the diol (x ′) having a phosphoric acid (salt) group include bis (2-hydroxyethyl) phosphate (salt).
The salts that make up the acid salts include ammonium salts, amine salts (methylamine salts, dimethylamine salts, trimethylamine salts, ethylamine salts, diethylamine salts, triethylamine salts, propylamine salts, dipropylamine salts, tripropylamine salts, butylamines. Salt, dibutylamine salt, tributylamine salt, monoethanolamine salt, diethanolamine salt, triethanolamine salt, N-methylethanolamine salt, N-ethylethanolamine salt, N, N-dimethylethanolamine salt, N, N- Diethylethanolamine salt, hydroxylamine salt, N, N-diethylhydroxylamine salt, morpholine salt, etc.), quaternary ammonium salt [tetramethylammonium salt, tetraethylammonium salt and trimethyl (2-hydroxyethyl) Ammonium salts, alkali metal salts (sodium salts and potassium salts, etc.).

  Among the diols (x ′) having a functional group, preferred from the viewpoint of compatibility are the diol (x ′) having a carboxylic acid (salt) group and the diol (x ′) having a sulfonic acid (salt) group. .

  Examples of the dicarboxylic acid of the dicarboxylic acid component (y) constituting the crystalline polyester (a11) include alkane dicarboxylic acids having 2 to 50 carbon atoms (including carbon of the carbonyl group) (succinic acid, adipic acid, sebacic acid, azelaic acid , Dodecanedioic acid such as dodecanedioic acid, octadecanedicarboxylic acid, decylsuccinic acid, etc .; alkenedicarboxylic acid having 4 to 50 carbon atoms (alkenylsuccinic acid such as dodecenyl succinic acid, pentadecenyl succinic acid, octadecenyl succinic acid, etc.) , Maleic acid, fumaric acid, citraconic acid, etc.); alicyclic dicarboxylic acid having 6 to 40 carbon atoms [dimer acid (dimerized linoleic acid), etc.]; aromatic dicarboxylic acid having 8 to 36 carbon atoms (phthalic acid, isophthalic acid) Acid, terephthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-bi Enirujikarubon acid, etc.) and the like. Two or more of these may be used in combination.

Among these dicarboxylic acids, it is preferable to use an aliphatic dicarboxylic acid of an alkane dicarboxylic acid and an alkene dicarboxylic acid from the viewpoint of crystallinity, and an aliphatic dicarboxylic acid having 2 to 50 carbon atoms and an aliphatic dicarboxylic acid having 4 to 50 carbon atoms. A group dicarboxylic acid is more preferable, and a linear dicarboxylic acid is particularly preferable. For example, adipic acid, sebacic acid, dodecanedioic acid and the like are particularly preferable.
Likewise preferred are those obtained by copolymerizing an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid (terephthalic acid, isophthalic acid, t-butylisophthalic acid, and lower alkyl esters thereof). The copolymerization amount of the aromatic dicarboxylic acid is preferably 20 mol% or less.

  In the production of the crystalline polyester (a11), the tricarboxylic or higher polycarboxylic acid component used as necessary includes polycarboxylic acids having a valence of 3 to 6 or higher. Examples of polycarboxylic acids having 3 to 6 or more valences include, for example, aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), and aliphatic tricarboxylic acids having 6 to 36 carbon atoms. (Hexanetricarboxylic acid etc.), vinyl polymer of unsaturated carboxylic acid [number average molecular weight (Mn): 450-10,000] (styrene / maleic acid copolymer, styrene / acrylic acid copolymer, and styrene / fumarate) Acid copolymer, etc.). The number average molecular weight (Mn) is determined by gel permeation chromatography (GPC).

  In addition, as dicarboxylic acid or polycarboxylic acid having 3 to 6 or more valences, acid anhydrides as described above, or lower alkyl esters having 1 to 4 carbon atoms (methyl ester, ethyl ester, isopropyl ester, etc.) May be used.

Crystalline polyurethane (a12):
The crystalline polyurethane (a12) that can be used as the segment (a1) is not particularly limited as long as it is compatible with the amorphous resin (B).

As the crystalline polyurethane (a12), those having the crystalline polyester (a11) and the diisocyanate (v2) as structural units, and the crystalline polyester (a11), the diol component (x) and the diisocyanate (v2) are used. And the like as structural units.
The crystalline polyurethane (a12) having the crystalline polyester (a11) and the diisocyanate (v2) as structural units can be obtained by reacting the crystalline polyester (a11) and the diisocyanate (v2). The crystalline polyurethane (a12) comprising the crystalline polyester (a11), the diol component (x) and the diisocyanate (v2) as structural units is obtained by reacting the crystalline polyester (a11), the diol component (x) and the diisocyanate (v2). Can be obtained.

  In addition to the diol component (x), the compatibility is improved by using the diol (x ′) having the functional group as a constituent unit.

  As the diisocyanate (v2), an aromatic diisocyanate having 6 to 20 carbon atoms (excluding carbon in the NCO group; the same shall apply hereinafter), an aliphatic diisocyanate having 2 to 18 carbon atoms, a modified product of these diisocyanates (urethane group, Carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group and oxazolidone group-containing modified product) and mixtures of two or more thereof.

  Examples of the aromatic diisocyanate having 6 to 20 carbon atoms include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), crude TDI, m- or p-xylylene diene. Isocyanate (XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI), 2,4′- or 4,4′-diphenylmethane diisocyanate (MDI), crude diaminophenylmethane diisocyanate (crude MDI) Etc.

Examples of the aliphatic diisocyanate having 2 to 18 carbon atoms include a chain aliphatic diisocyanate having 2 to 18 carbon atoms and a cyclic aliphatic diisocyanate having 3 to 18 carbon atoms.
Examples of the chain aliphatic diisocyanate having 2 to 18 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6- And diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate and mixtures thereof. It is done.

  Examples of the cycloaliphatic diisocyanate having 3 to 18 carbon atoms include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis ( 2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5- or 2,6-norbornane diisocyanate and mixtures thereof.

  As the modified product of diisocyanate, a modified product containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a burette group, a uretdione group, a uretoimine group, an isocyanurate group and / or an oxazolidone group is used. Urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbyl phosphate-modified MDI, etc.), urethane-modified TDI, and mixtures thereof (for example, a mixture of modified MDI and urethane-modified TDI (isocyanate-containing prepolymer)).

  Among these diisocyanates (v2), aromatic diisocyanates having 6 to 15 carbon atoms and aliphatic diisocyanates having 4 to 15 carbon atoms are more preferable, and TDI, MDI, HDI, hydrogenated MDI and IPDI are more preferable. It is.

Crystalline polyurea (a13):
The crystalline polyurea (a13) that can be used as the segment (a1) is not particularly limited as long as it is compatible with the amorphous resin (B).

  Examples of the crystalline polyurea (a13) include those having the crystalline polyester (a11), the diamine (z), and the diisocyanate (v2) as structural units. Such crystalline polyurea (a13) can be obtained by reacting crystalline polyester (a11), diamine (z) and diisocyanate (v2).

Examples of the diamine (z) include aliphatic diamines having 2 to 18 carbon atoms and aromatic diamines having 6 to 20 carbon atoms.
Examples of the aliphatic diamine having 2 to 18 carbon atoms include a chain aliphatic diamine and a cyclic aliphatic diamine.

Examples of chain aliphatic diamines include alkylene diamines having 2 to 12 carbon atoms (ethylene diamine, propylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and polyalkylene (2 to 6 carbon atoms) polyamines [diethylene triamine, imino. Bispropylamine, bis (hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, etc.].
Cycloaliphatic polyamines include alicyclic diamines having 4 to 15 carbon atoms {1,3-diaminocyclohexane, isophorone diamine, mensen diamine, 4,4'-methylene dicyclohexane diamine (hydrogenated methylene dianiline) and 3 , 9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane and the like} and a heterocyclic diamine having 4 to 15 carbon atoms [piperazine, N-aminoethylpiperazine, 1,4-diaminoethylpiperazine, 1,4-bis (2-amino-2-methylpropyl) piperazine, etc.] and the like.

  The aromatic diamine having 6 to 20 carbon atoms is an aromatic having an unsubstituted aromatic diamine or an alkyl group (an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n- or isopropyl group, and a butyl group). Examples include diamines.

  Examples of the unsubstituted aromatic diamine include 1,2-, 1,3- or 1,4-phenylenediamine, 2,4′- or 4,4′-diphenylmethanediamine, diaminodiphenylsulfone, benzidine, thiodianiline, bis (3 , 4-diaminophenyl) sulfone, 2,6-diaminopyridine, m-aminobenzylamine, naphthylenediamine and mixtures thereof.

  The aromatic diamine having an alkyl group (alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, n- or isopropyl group and butyl group) includes 2,4- or 2,6-tolylenediamine, crude Tolylenediamine, diethyltolylenediamine, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-bis (o-toluidine), dianisidine, diaminoditolylsulfone, 1,3-dimethyl-2 , 4-diaminobenzene, 1,3-diethyl-2,4-diaminobenzene, 1,3-dimethyl-2,6-diaminobenzene, 1,4-diethyl-2,5-diaminobenzene, 1,4-diisopropyl -2,5-diaminobenzene, 1,4-dibutyl-2,5-diaminobenzene, 2,4-diaminomesitylene, 1,3,5-triethyl -2,4-diaminobenzene, 1,3,5-triisopropyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl -2,6-diaminobenzene, 2,3-dimethyl-1,4-diaminonaphthalene, 2,6-dimethyl-1,5-diaminonaphthalene, 2,6-diisopropyl-1,5-diaminonaphthalene, 2,6 -Dibutyl-1,5-diaminonaphthalene, 3,3 ', 5,5'-tetramethylbenzidine, 3,3', 5,5'-tetraisopropylbenzidine, 3,3 ', 5,5'-tetramethyl -4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetraisopropyl-4, '-Diaminodiphenylmethane, 3,3', 5,5'-tetrabutyl-4,4'-diaminodiphenylmethane, 3,5-diethyl-3'-methyl-2 ', 4-diaminodiphenylmethane, 3,5-diisopropyl- 3'-methyl-2 ', 4-diaminodiphenylmethane, 3,3'-diethyl-2,2'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 3,3', 5 5′-tetraethyl-4,4′-diaminobenzophenone, 3,3 ′, 5,5′-tetraisopropyl-4,4′-diaminobenzophenone, 3,3 ′, 5,5′-tetraethyl-4,4 ′ -Diaminodiphenyl ether, 3,3 ', 5,5'-tetraisopropyl-4,4'-diaminodiphenyl sulfone and mixtures thereof Can be mentioned.

  As the diisocyanate (v2), an aromatic diisocyanate having 6 to 20 carbon atoms (excluding carbon in the NCO group; the same shall apply hereinafter), an aliphatic diisocyanate having 2 to 18 carbon atoms, a modified product of these diisocyanates (urethane group, Carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group and oxazolidone group-containing modified product) and mixtures of two or more thereof.

  Examples of the aromatic diisocyanate having 6 to 20 carbon atoms include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), crude TDI, m- or p-xylylene diene. Isocyanate (XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI), 2,4′- or 4,4′-diphenylmethane diisocyanate (MDI), crude diaminophenylmethane diisocyanate (crude MDI) Etc.

Examples of the aliphatic diisocyanate having 2 to 18 carbon atoms include a chain aliphatic diisocyanate having 2 to 18 carbon atoms and a cyclic aliphatic diisocyanate having 3 to 18 carbon atoms.
Examples of the chain aliphatic diisocyanate having 2 to 18 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6- And diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate and mixtures thereof. It is done.

  Examples of the cycloaliphatic diisocyanate having 3 to 18 carbon atoms include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis ( 2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5- or 2,6-norbornane diisocyanate and mixtures thereof.

  As the modified product of diisocyanate, a modified product containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a burette group, a uretdione group, a uretoimine group, an isocyanurate group and / or an oxazolidone group is used. Urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbyl phosphate-modified MDI, etc.), urethane-modified TDI, and mixtures thereof (for example, a mixture of modified MDI and urethane-modified TDI (isocyanate-containing prepolymer)).

  Among these diisocyanates (v2), aromatic diisocyanates having 6 to 15 carbon atoms and aliphatic diisocyanates having 4 to 15 carbon atoms are more preferable, and TDI, MDI, HDI, hydrogenated MDI and IPDI are more preferable. It is.

Crystalline polyamide (a14):
The crystalline polyamide (a14) that can be used as the segment (a1) is not particularly limited as long as it is compatible with the amorphous resin (B).

  Examples of the crystalline polyamide (a14) include those having the crystalline polyester (a11), the diamine (z), and the dicarboxylic acid component (y) as structural units. Such crystalline polyamide (a14) can be obtained by reacting the crystalline polyester (a11), the diamine (z) and the dicarboxylic acid component (y).

Crystalline polyvinyl resin (a15):
The crystalline polyvinyl resin (a15) that can be used as the segment (a1) is not particularly limited as long as it is compatible with the amorphous resin (B).

Examples of the crystalline polyvinyl resin (a15) include a polymer obtained by homopolymerizing or copolymerizing an ester having a polymerizable double bond.
Examples of the ester having a polymerizable double bond include vinyl acetate, vinyl propionate, vinyl butyrate, diallyl phthalate, diallyl adipate, isopropenyl acetate, vinyl methacrylate, methyl-4-vinyl benzoate, cyclohexyl methacrylate, benzyl methacrylate, phenyl (meta ) Acrylate, vinyl methoxyacetate, vinyl benzoate, ethyl-α-ethoxy acrylate, alkyl (meth) acrylate having an alkyl group having 1 to 50 carbon atoms [methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate , Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) ) Acrylate and eicosyl (meth) acrylate, etc.], dialkyl fumarate (two alkyl groups are straight, branched or alicyclic groups having 2 to 8 carbon atoms), dialkyl maleate (two The alkyl group is a linear, branched or alicyclic group having 2 to 8 carbon atoms), poly (meth) allyloxyalkanes (dialyloxyethane, triaryloxyethane, tetraallyloxyethane) Monomers having a polyalkylene glycol chain and a polymerizable double bond, such as tetraallyloxypropane, tetraallyloxybutane and tetrametaallyloxyethane, etc. [polyethylene glycol (Mn = 300) mono (meth) acrylate, polypropylene Glycol (Mn = 500) monoacrylate, methyl alcohol EO 10 mol adduct (meth) acrylate and laur Lyl alcohol EO 30 mol adduct (meth) acrylate, etc.], poly (meth) acrylates [poly (meth) acrylate of polyhydric alcohols: ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyethylene glycol di (meth) acrylate and the like] and the like.

  In addition to the ester having a polymerizable double bond, the crystalline polyvinyl resin (a15) can contain compounds such as the following monomers (w1) to (w9) as constituent monomers.

Monomer (w1) Hydrocarbon having a polymerizable double bond:
Examples thereof include the following (w11) aliphatic hydrocarbon having a polymerizable double bond and (w12) aromatic hydrocarbon having a polymerizable double bond.
(W11) Aliphatic hydrocarbon having a polymerizable double bond:
For example, the following (w111) and (w112) are mentioned.
(W111) Chain hydrocarbon having a polymerizable double bond: Alkene having 2 to 30 carbon atoms (for example, isoprene, 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene, etc.).
(W112) Cyclic hydrocarbon having a polymerizable double bond: mono- or dicycloalkene having 6 to 30 carbon atoms (such as cyclohexene, vinylcyclohexene and ethylidenebicycloheptene) and mono- or dicycloalkoxy having 5 to 30 carbon atoms Diene [for example, (di) cyclopentadiene and the like] and the like.

(W12) Aromatic hydrocarbon having a polymerizable double bond:
Styrene; hydrocarbyl (alkyl, cycloalkyl, aralkyl and / or alkenyl having 1 to 30 carbon atoms) substitution of styrene (for example, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, Butyl styrene, phenyl styrene, cyclohexyl styrene, benzyl styrene, crotyl benzene, divinyl benzene, divinyl toluene, divinyl xylene, and trivinyl benzene); and vinyl naphthalene.

(W2) Monomers having a carboxyl group and a polymerizable double bond and their salts:
C3-C15 unsaturated monocarboxylic acid {For example, (meth) acrylic acid ["(meth) acryl" means acryl or methacryl. ], Crotonic acid, isocrotonic acid, cinnamic acid and the like}; C3-C30 unsaturated dicarboxylic acid (anhydride) [for example, (anhydrous) maleic acid, fumaric acid, itaconic acid, (anhydrous) citraconic acid, mesaconic acid, etc. And monoalkyl (C1-10) esters of unsaturated dicarboxylic acids having 3 to 10 carbon atoms (eg maleic acid monomethyl ester, maleic acid monodecyl ester, fumaric acid monoethyl ester, itaconic acid monobutyl ester and citracone) Acid monodecyl ester, etc.).

Examples of the salt constituting the monomer salt having a carboxyl group and a polymerizable double bond include alkali metal salts (such as sodium salt and potassium salt), alkaline earth metal salts (such as calcium salt and magnesium salt), and ammonium. Examples thereof include salts, amine salts, and quaternary ammonium salts.
The amine salt is not particularly limited as long as it is an amine compound. For example, primary amine salts (such as ethylamine salts, butylamine salts and octylamine salts), secondary amines (such as diethylamine salts and dibutylamine salts), tertiary amines ( Triethylamine salt and tributylamine salt). Examples of the quaternary ammonium salt include tetraethylammonium salt, triethyllaurylammonium salt, tetrabutylammonium salt, and tributyllaurylammonium salt.

  Examples of the salt of the monomer having a carboxyl group and a polymerizable double bond include sodium acrylate, sodium methacrylate, monosodium maleate, disodium maleate, potassium acrylate, potassium methacrylate, monopotassium maleate, acrylic Examples include lithium acid, cesium acrylate, ammonium acrylate, calcium acrylate, and aluminum acrylate.

(W3) Monomers having a sulfo group and a polymerizable double bond and their salts:
Alkene sulfonic acids having 2 to 14 carbon atoms (for example, vinyl sulfonic acid, (meth) allyl sulfonic acid and methyl vinyl sulfonic acid); styrene sulfonic acid and alkyl (2 to 24 carbon) derivatives thereof (for example, α-methyl styrene sulfone) Acid etc .; C5-C18 sulfo (hydroxy) alkyl- (meth) acrylate [for example, sulfopropyl (meth) acrylate, 2-hydroxy-3- (meth) acryloxypropylsulfonic acid, 2- (meth) acryloyloxy Ethanesulfonic acid and 3- (meth) acryloyloxy-2-hydroxypropanesulfonic acid and the like]; sulfo (hydroxy) alkyl (meth) acrylamide having 5 to 18 carbon atoms [for example, 2- (meth) acryloylamino-2,2- Dimethylethanesulfonic acid, 2- (meth) acrylic Do-2-methylpropanesulfonic acid and 3- (meth) acrylamide-2-hydroxypropanesulfonic acid, etc.]; alkyl (C3-C18) allylsulfosuccinic acid (for example, propylallylsulfosuccinic acid, butylallylsulfosuccinic acid, 2- Ethylhexyl-allylsulfosuccinic acid, etc.); poly [n (degree of polymerization, the same applies hereinafter) = 2-30] oxyalkylene (oxyethylene, oxypropylene, oxybutylene, etc.). Oxyalkylene may be used alone or in combination. The addition type may be random addition or block addition.) Sulfate ester of mono (meth) acrylate [for example, poly (n = 5-15) oxyethylene monomethacrylate sulfate and poly (n = 5-15) oxypropylene monomethacrylate sulfate Esters etc.]; And salts thereof.

  In addition, as a salt, what was illustrated as a salt which comprises the salt of the monomer which has (w2) a carboxyl group and a polymerizable double bond is mentioned.

(W4) Monomer having phosphono group and polymerizable double bond and salt thereof:
(Meth) acryloyloxyalkyl phosphate monoester (alkyl group having 1 to 24 carbon atoms) (for example, 2-hydroxyethyl (meth) acryloyl phosphate and phenyl-2-acryloyloxyethyl phosphate), (meth) acryloyloxyalkyl Phosphonic acid (alkyl group having 1 to 24 carbon atoms) (for example, 2-acryloyloxyethylphosphonic acid).
In addition, as a salt, what was illustrated as a salt which comprises the monomer which has (w2) a carboxyl group and a polymerizable double bond is mentioned.

(W5) Monomer having a hydroxyl group and a polymerizable double bond:
Hydroxystyrene, N-methylol (meth) acrylamide, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1- Buten-3-ol, 2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethylpropenyl ether, sucrose allyl ether, and the like.

(W6) Nitrogen-containing monomer having a polymerizable double bond:
For example, (w61) a monomer having an amino group and a polymerizable double bond, (w62) a monomer having an amide group and a polymerizable double bond, (w63) carbon having a nitrile group and a polymerizable double bond. And monomers having 3 to 10 carbon atoms, (w64) monomers having 8 to 12 carbon atoms having a nitro group and a polymerizable double bond.
(W61) Monomer having amino group and polymerizable double bond:
Aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, t-butylaminoethyl methacrylate, N-aminoethyl (meth) acrylamide, (meth) allylamine, morpholinoethyl (meth) acrylate, 4-vinylpyridine, 2-vinylpyridine, crotylamine, N, N-dimethylaminostyrene, methyl-α-acetaminoacrylate, vinylimidazole, N-vinylpyrrole, N-vinylthiopyrrolidone, N-arylphenylenediamine, aminocarbazole Aminothiazole, aminoindole, aminopyrrole, aminoimidazole, aminomercaptothiazole, and salts thereof.

(W62) Monomer having an amide group and a polymerizable double bond:
(Meth) acrylamide, N-methyl (meth) acrylamide, N-butyl acrylamide, diacetone acrylamide, N-methylol (meth) acrylamide, N, N′-methylene-bis (meth) acrylamide, cinnamic amide, N, N -Dimethylacrylamide, N, N-dibenzylacrylamide, methacrylformamide, N-methyl-N-vinylacetamide, N-vinylpyrrolidone and the like.
(W63) C3-C10 monomer having a nitrile group and a polymerizable double bond:
(Meth) acrylonitrile, cyanostyrene, cyanoacrylate and the like.
(W64) C8-12 monomer having a nitro group and a polymerizable double bond:
Nitrostyrene etc.

(W7) C6-C18 monomer having a glycidyl group and a polymerizable double bond:
Glycidyl (meth) acrylate and p-vinylphenylphenyl oxide.

(W8) C2-C16 monomer having a halogen element and a polymerizable double bond:
Vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, chloroprene and the like.

(W9) Ether having a polymerizable double bond, a ketone having a polymerizable double bond, and a sulfur-containing compound having a polymerizable double bond:
For example, (w91) C3-C16 ether having a polymerizable double bond, (w92) C4-C12 ketone having a polymerizable double bond, (w93) Carbon number having a polymerizable double bond. Examples thereof include 2 to 16 sulfur-containing compounds.
(W91) C3-C16 ether having a polymerizable double bond:
Vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, vinyl butyl ether, vinyl-2-ethylhexyl ether, vinyl phenyl ether, vinyl-2-methoxyethyl ether, methoxybutadiene, vinyl-2-butoxyethyl ether, 3,4-dihydro -1,2-pyran, 2-butoxy-2′-vinyloxydiethyl ether, acetoxystyrene, phenoxystyrene, and the like.
(W92) C4-C12 ketone having a polymerizable double bond:
Examples include vinyl methyl ketone, vinyl ethyl ketone, and vinyl phenyl ketone.
(W93) C2-C16 sulfur-containing compound having a polymerizable double bond:
Examples thereof include divinyl sulfide, p-vinyl diphenyl sulfide, vinyl ethyl sulfide, vinyl ethyl sulfone, divinyl sulfone, and divinyl sulfoxide.

  Among the segments (a1) that are compatible with the amorphous resin (B), the crystalline polyester (a11), the crystalline polyurethane (a12), and the crystalline polyurea (a13) are preferable from the viewpoint of moldability. More preferred are crystalline polyester (a11) and crystalline polyurethane (a12). As a segment (a1), the structure comprised from such a compound is preferable.

<Segment (a2)>
The segment (a2) that is incompatible with the (B) constituting the resin (A) together with the segment (a1) that is compatible with the amorphous resin (B) is compatible with the amorphous resin (B). If it is a structure comprised from the compound which does not carry out, it will not specifically limit. In practice, segment (a2) may be the compound itself.
Examples of the compound incompatible with the amorphous resin (B) include, for example, a long-chain alkyl monoalcohol (preferably having 18 to 42 carbon atoms), a long-chain alkyl monocarboxylic acid (preferably having 18 to 42 carbon atoms), and at least a hydroxyl group. Examples thereof include polybutadiene having one, dimethylsiloxane having at least one hydroxyl group, and preferably a long-chain alkyl monoalcohol having 18 to 42 carbon atoms and a long-chain alkyl monocarboxylic acid having 18 to 42 carbon atoms.
The segment (a2) is preferably a structure composed of such a compound. As the long-chain alkyl monoalcohol having 18 to 42 carbon atoms, for example, behenyl alcohol, stearyl alcohol and the like are preferable.

  In the resin (A) in the present invention, the segment (a1) and the segment (a2) are chemically bonded in the same molecule.

The chemical bond is preferably one or more functional groups selected from the group consisting of an ester group, a urethane group, a urea group, and an amide group from the viewpoint of moldability. From the same viewpoint, an ester group and a urethane group are further included. preferable.
In the present invention, the segment (a1) and the segment (a2) in the resin (A) are bonded with one or more functional groups selected from the group consisting of an ester group, a urethane group, a urea group, and an amide group. It is preferable. Thus, the resin (A) in which the segment (a1) and the segment (a2) are bonded with one or more functional groups selected from the group consisting of an ester group, a urethane group, a urea group, and an amide group, Preferred as the resin (A) in the present invention.

In addition to the combination of one type of segment (a1) and one type of segment (a2), when one or more types of segments (a1) and one or more types of segments (a2) include a total of three or more types of segments But you can. For example, the segment (a1) and the segment (a2) may be chemically bonded via the above-described functional group, and the above-mentioned functional group including the segment (a1) and the segment (a3) other than the segment (a2). Chemical bonding may be performed via
Examples of the segment (a3) include an amorphous segment that is compatible with the amorphous resin (B).

  Accordingly, in the case of including three or more types of segments, for example, a combination of one type of segment (a1), one type of segment (a2), and one type of segment (a3), two types of segments (a1) and 1 A combination of seed segment (a2), a combination of one kind of segment (a1) and two kinds of segments (a2), and the like can be mentioned. Here, as an example of two or more types of segments, there may be mentioned a case where the molecular weight and other physical properties are different even if the types of chemical structures are the same (for example, polyesters).

The weight average molecular weight of the resin (A) (hereinafter, the weight average molecular weight may be abbreviated as Mw) is preferably 1,000 to 150,000, and more preferably from the viewpoints of grindability and coating film smoothness. Is from 2,000 to 120,000, particularly preferably from 2,500 to 100,000, most preferably from 3,000 to 80,000.
Mw and the number average molecular weight (also referred to as Mn in this specification) are as follows using resin (A) dissolved in tetrahydrofuran (THF) and using gel permeation chromatography (GPC) as a sample solution. Measured under the following conditions.
Device (example): HLC-8120 manufactured by Tosoh Corporation
Column (example): TSK GEL GMH6 2 [Tosoh Corp.]
Measurement temperature: 40 ° C
Sample solution: 0.25 wt% THF solution Injection amount: 100 μL
Detection device: Refractive index detector Reference material: TOSANDO standard polystyrene (TSK standard POLYSYRENE) 12 points (molecular weight 500 1050 2800 5970 9100 18100 37900 96400 1900000 355000 1090000
2890000)

<Amorphous resin (B)>
The non-crystalline resin (B) having a carboxyl group and / or a hydroxyl group in the present invention is not particularly limited as long as the resin composition has a carboxyl group and / or a hydroxyl group and is softened by heat. Examples include polyester resin, acrylic resin, polyurethane resin, ABS resin, polypropylene resin, polyolefin resin, polyethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polystyrene resin, vinyl acetate copolymer resin, and the like. From the viewpoint of physical properties of the coating film, it is preferable to use a polyester resin or an acrylic resin.
The functional group equivalent of the amorphous resin (B) is preferably 1000 to 10000 g / eq, more preferably 1500 to 5000 g / eq, from the viewpoint of the smoothness of the paint and the coating film strength.
The number of functional groups in the amorphous resin (B) is preferably from 2 to 15, more preferably from the viewpoint of coating strength and storage stability of the powder coating resin composition (Y) described later. 2 to 8.
In the present invention, “non-crystallinity” means a stepwise change in endothermic amount during the second temperature increase process of measurement in the method (DSC method) defined in ASTM D3418-82 in a differential scanning calorimeter (DSC). Refers to a resin having no clear endothermic peak.

<Main agent composition for powder coating (X)>
The main component composition (X) for powder coatings of the present invention comprises the resin (A) and the amorphous resin (B).

The glass transition point (Tg _x ) of the main component composition for powder coating (X) is preferably 100 ° C. or less, more preferably 40 to 90 ° C., and even more preferably 50 to 80 ° C. from the viewpoint of moldability.
In addition, when there are two or more glass transition points of the main component composition for powder coating (X), the temperature showing the lowest temperature is defined as the glass transition point (Tg _X ).

As described above, the resin (A) is a resin in which at least two types of segments are chemically bonded, and the segment (a2) that is incompatible with the segment (a1) that is compatible with the amorphous resin (B); Have
At that time, assuming that the solubility parameter of the amorphous resin (B) is SP _B , the solubility parameter of the segment (a1) is SP _a1 , and the solubility parameter of the segment (a2) is SP _a2 , the segment (a1) It is preferable that the segment (a2) satisfies both the following relational expressions (2) and (3).

| SP _a1 −SP _B | ≦ 1.9 (2)
| SP _a2 −SP _B | ≧ 1.9 (3)
In the above formula, SP _a1 represents the SP value of the segment (a1), SP _a2 represents the SP value of the segment (a2), and SP _B represents the SP value of the resin (B).
The SP values of the segment (a1) and the segment (a2) are SP values of the compounds constituting each segment.
In addition, when including 2 or more types of segments (a1), it calculates by the arithmetic average by those containing weight ratios, and the same applies also when 2 or more types of segments (a2) are included.

The value on the left side of the relational expression (2) is usually 1.9 or less, preferably 0.1 to 1.8, from the viewpoint of compatibility between the amorphous resin (B) and the segment (a1).
Similarly, the value on the left side of the relational expression (3) is usually 1.9 or more, preferably 2.0 or more, from the viewpoint of compatibility between the amorphous resin (B) and the segment (a2). The upper limit of the value on the left side of the relational expression (3) is preferably 4.0 or less, and more preferably 3.5 or less.
By satisfying both of the relational expressions (2) and (3), plasticization at the time of heating by the resin (A) and recrystallization at the time of cooling easily occur, and pulverization of the resin composition for powder coating (Y) described later And the smoothness of the produced coating film is improved.

  In addition, SP value in this invention is the method by Fedors [Polym. Eng. Sci. 14 (2) 152, (1974)].

  One type of amorphous resin (B) may be used, or two or more types may be used.

In the present invention, the glass transition point of the amorphous resin (B) is Tg ₁ (° C.), and the amorphous resin (B) is derived from the amorphous resin (B) in the mixture obtained by adding the resin (A) to the amorphous resin (B). When the glass transition point is Tg ₂ (° C.), it is preferable that Tg ₁ (° C.) and Tg ₂ (° C.) satisfy the following relational expression (1).

When two or more glass transition points of the amorphous resin (B) are present, the temperature showing the lowest temperature is defined as the glass transition point (Tg ₁ ), and the resin (A) is similarly added to the amorphous resin (B). When there are two or more glass transition points derived from the amorphous resin (B) in the mixture to which is added, the temperature showing the lowest temperature is defined as the glass transition point (Tg ₂ ).

Tg ₁ −Tg ₂ ≦ 15 (1)

The weight ratio [(B) / (A)] between the amorphous resin (B) and the resin (A) is a viewpoint of the pulverizability, the smoothness of the coating film, and the strength of the resin composition for powder coating (Y). Therefore, it is usually preferably 50/50 to 98/2, and more preferably 70/30 to 95/3.
A mixture containing the amorphous resin (B) and the resin (A) in the above proportion is preferable as the main component composition (X) for powder coatings of the present invention. That is, the weight ratio [(B) / (A)] of the amorphous resin (B) and the resin (A) in the main component composition (X) for the powder coating of the present invention is preferably in the above range.

  The resin (A) used in the present invention is preferably crystalline. In the present invention, “crystallinity” refers to a resin having a clear endothermic peak, not a stepwise change in endothermic amount in the second temperature rising process of the DSC measurement.

<Resin composition for powder coating (Y)>
The resin composition for powder coatings (Y) of this invention contains the said main ingredient composition for powder coatings (X) and the below-mentioned crosslinking agent (C). That is, it contains the resin (A), the resin (B), and the crosslinking agent (C).

<Crosslinking agent (C)>
The crosslinking agent (C) is not particularly limited as long as it is a compound having a functional group that chemically reacts with the carboxyl group and / or the hydroxyl group of the amorphous resin (A) having a carboxyl group and / or a hydroxyl group. Compound (C1) [block isocyanate, triglycidyl isocyanurate (TGIC), etc.], β-hydroxyalkylamide (HAA), epoxy resin (C2), acrylic resin having carboxyl group and / or hydroxyl group and / or epoxy group (C3 ), A polyester resin (C4) having a carboxyl group and / or a hydroxyl group and / or an epoxy group.
The functional group equivalent of the crosslinking agent (C) is smaller than the functional group equivalent of the resin (B). The functional group equivalent of the crosslinking agent (C) is preferably 100 to 950 g / eq, more preferably 150 to 900 g / eq, from the viewpoint of coating strength and storage stability of (Y).

  The isocyanate compound (C1) preferably has a softening point of 10 to 120 ° C, particularly preferably 40 to 100 ° C. A softening point of less than 10 ° C. is not preferable because the powder coating composition is cured in a room temperature environment or a granular lump is formed. On the other hand, when the softening point exceeds 120 ° C., it becomes difficult to uniformly disperse the isocyanate compound in the powder coating composition when the powder coating composition is produced by melt kneading. Performances such as smoothness, coating strength, and moisture resistance may be impaired. In the isocyanate compound, the isocyanate group is preferably 0.05 to 1.5 equivalents, particularly preferably 0.8 to 1.2 equivalents, based on the hydroxyl groups in the resin. If the isocyanate group is less than 0.05 equivalent, the degree of cure of the powder coating composition may be insufficient, and coating performance such as adhesion, coating hardness, and chemical resistance may be lowered. Moreover, when this isocyanate group exceeds 1.5 equivalent, there exists a possibility that a coating film may become weak, heat resistance, chemical resistance, moisture resistance, etc. may be inferior.

  The blocked isocyanate is preferably solid at room temperature. For example, a polyisocyanate obtained by reacting an aliphatic, aromatic or araliphatic diisocyanate with a low molecular weight compound having active hydrogen is reacted with a blocking agent. Since it can be manufactured by masking, it is easy to manufacture. Examples of the diisocyanate include tolylene diisocyanate, 4,4′-diphenylmethane isocyanate, xylylene diisocyanate, hexamethylene diisocyanate, 4,4′-methylene bis (cyclohexyl isocyanate), methylcyclohexane diisocyanate, bis (isocyanatomethyl) cyclohexane, isophorone. Diisocyanate, dimer acid diisocyanate, lysine diisocyanate, etc. can be mentioned. Examples of the low molecular weight compound having active hydrogen include water, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, ethanolamine, diethanolamine, hexamethylenediamine. Etc., isocyanurate, uretidione, hydroxyl group Low molecular weight polyesters having, polycaprolactone and the like. Specific examples of the blocking agent include alcohols such as methanol, ethanol and benzyl alcohol, phenols such as phenol and crezone, lactams such as caprolactam and butyrolactam, and oximes such as cyclohexanone, oxime and methyl ethyl ketoxime. . For example, specific examples of the blocked isocyanate include isophorone diisocyanate blocked with ε-caprolactam (Vestagon B1530 manufactured by Evonik, Clelan UI manufactured by Bayer) and the like.

  As triglycidyl isocyanurate (TGIC), for example, as trade names, Araldite (registered trademark) PT 710, Araldite (registered trademark) PT 810, Araldite (registered trademark) PT 910, Araldite (registered trademark) PT 912 (all Huntsman) Etc.).

  As β-hydroxyalkylamide (HAA) (C2), those having two or more functional groups per molecule are particularly preferred from the viewpoint of low-temperature curability and the water resistance of a coating film obtained by coating. . Examples of β-hydroxyalkylamide include N, N-di (β-hydroxyethyl) acetamide, bis (β-hydroxyethyl) adipamide, bis (β-hydroxypropyl) adipamide, bis [N, N-di (β-hydroxy). Ethyl)] adipamide and bis [N, N-di (β-hydroxypropyl)] adipamide are particularly preferred. In the β-hydroxyalkylamide, the hydroxylamide group is preferably 0.5 to 1.5 equivalents relative to the carboxyl group in the resin.

The epoxy resin (C3) is not particularly limited, and an epoxy resin conventionally used in the production of an epoxy resin powder coating composition can be used.
Specific examples of the epoxy resin (C3) include bisphenol A type diglycidyl ether resin, bisphenol F type diglycidyl ether resin, aminoglycidyl ether resin, bisphenol AD type diglycidyl ether resin, and bisphenol Z type diglycidyl ether resin. , O-cresol novolac epoxy resins, phenol novolac epoxy resins, biphenol glycidyl ether resins, cyclopentadiene skeleton epoxy resins, naphthalene skeleton epoxy resins, etc., and resins in which substituents other than the epoxy groups of these resins are replaced with other substituents Examples thereof include a resin obtained by a modification reaction using carboxyl group-terminated polybutadiene-acrylonitrile (CTBN) or a modification reaction such as esterification. The epoxy resin preferably has an epoxy equivalent of 300 to 1200, particularly preferably 400 to 1000.

  The carboxyl group and / or hydroxyl group and / or glycidyl group-containing acrylic resin (C4) mainly refers to a vinyl copolymer having a carboxyl group and / or a hydroxyl group and / or a glycidyl group at the terminal or side chain of the molecule. Is.

Examples of the carboxyl group-containing acrylic resin (41) include a polymer obtained by homopolymerizing or copolymerizing an ester having a polymerizable double bond shown below and a compound such as the aforementioned monomers (w1) to (w9). Is a polymer having a monomer (w2) having a carboxyl group and a polymerizable double bond as an essential constituent.
Examples of the ester having a polymerizable double bond include vinyl acetate, vinyl propionate, vinyl butyrate, diallyl phthalate, diallyl adipate, isopropenyl acetate, vinyl methacrylate, methyl-4-vinyl benzoate, cyclohexyl methacrylate, benzyl methacrylate, phenyl (meta ) Acrylate, vinyl methoxyacetate, vinyl benzoate, ethyl-α-ethoxy acrylate, alkyl (meth) acrylate having an alkyl group having 1 to 50 carbon atoms [methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate , Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) ) Acrylate and eicosyl (meth) acrylate, etc.], dialkyl fumarate (two alkyl groups are straight, branched or alicyclic groups having 2 to 8 carbon atoms), dialkyl maleate (two The alkyl group is a linear, branched or alicyclic group having 2 to 8 carbon atoms), poly (meth) allyloxyalkanes (dialyloxyethane, triaryloxyethane, tetraallyloxyethane) Monomers having a polyalkylene glycol chain and a polymerizable double bond, such as tetraallyloxypropane, tetraallyloxybutane and tetrametaallyloxyethane, etc. [polyethylene glycol (Mn = 300) mono (meth) acrylate, polypropylene Glycol (Mn = 500) monoacrylate, methyl alcohol EO 10 mol adduct (meth) acrylate and laur Lyl alcohol EO 30 mol adduct (meth) acrylate, etc.], poly (meth) acrylates [poly (meth) acrylate of polyhydric alcohols: ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyethylene glycol di (meth) acrylate and the like] and the like.

  Examples of the hydroxyl group-containing acrylic resin (C42) include polymers obtained by homopolymerizing or copolymerizing the aforementioned ester having a polymerizable double bond and compounds such as monomers (w1) to (w9). It is a polymer containing a monomer (w5) having a polymerizable double bond as an essential constituent component.

Examples of the glycidyl group-containing acrylic resin (C43) include a polymer obtained by homopolymerizing or copolymerizing the above-described ester having a polymerizable double bond and a compound such as monomers (w1) to (w9). It is a polymer containing a monomer having 6 to 18 carbon atoms (w7) having a group and a polymerizable double bond as an essential component.
The glycidyl group-containing acrylic resin (C43) preferably has an epoxy equivalent in the range of 150 to 1,000.

In the resin composition for powder coatings (Y) of the present invention, a filler, an antiseptic, a heat stabilizer, a weather stabilizer, a colorant, a thickener, and a leveling are necessary as long as the effects of the present invention are not impaired. 1 type (s) or 2 or more types of additives (D) chosen from the group which consists of an agent, an antifoamer, a viscoelasticity adjusting agent, and a dynamic surface tension adjusting agent can be contained.
The (D) can be added at any stage of the production process (Y).
The total content of the additive (D) is usually 30% or less, preferably 0.1 to 20%, more preferably based on the total weight of the resin composition for powder coating (Y) after addition of the additive. 0.2 to 10%.

Examples of the filler (D1) include a colorant (such as titanium dioxide), sodium carbonate, and silica.
The content of (D1) is usually 35% or less, preferably 0.1 to 30%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

Examples of the preservative (D2) include methyl paraben and ethyl paraben.
The content of (D2) is usually 10% or less, preferably 0.1 to 3%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

Examples of the heat resistance stabilizer (D3) include tris (2,4-di-t-butylphenyl) phosphate, dioctadecyl-3,3′-thiodipropionate, and the like.
The content of (D3) is usually 10% or less, preferably 0.1 to 3%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

Examples of the weathering stabilizer (D4) include ultraviolet absorbers such as salicylic acid compounds (phenyl salicylate, etc.), benzophenones (2,4-dihydroxybenzophenone, etc.), benzotriazole compounds [2- (2′-hydroxy-5′-methylphenyl). ) Benzotriazole, etc.], cyanoacrylate compounds (2-ethylhexyl-2-cyano-3,3′-diphenylacrylate, etc.); light stabilizers such as hindered amines [octylated diphenylamine, isooctyl-3- (3,5-di-) tert-butyl-4-hydroxyphenol) propionate, etc.].
The content of (D4) is usually 10% or less, preferably 0.5 to 3%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

Colorants (D5) include pigments and dyes. Among the pigments, inorganic pigments include titanium oxide, carbon black and the like; organic pigments include azo pigments (azo lakes, monoazos, etc.) and polycyclic pigments (benzimidazolones, phthalocyanines, etc.).
Examples of the dye include nigrosine and aniline.
The content of (D5) is usually 30% or less, preferably 1 to 10%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

Examples of the thickener (D6) include montmorillonite and colloidal alumina.
The content of (D6) is usually 10% or less, preferably 0.1 to 5%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

As the leveling agent (D7), Mn is preferably 100 to 1,000, polyolefin resin [polyethylene, polypropylene, etc.], olefin- (meth) acrylic acid copolymer [ethylene- (meth) acrylic acid copolymer, etc. ], Polyvinylpyrrolidone, etc. are mentioned.
The content of (D7) is usually 6% or less, preferably 0.5 to 3%, based on the total weight of the resin composition for powder coatings (Y) after addition of the additive.

Examples of the antifoaming agent (D8) include mineral oil defoaming agents, silicone oil defoaming agents, and benzoin.
The content of (D8) is usually 6% or less, preferably 0.5 to 3%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

As the viscoelasticity adjusting agent (D9), a polymer type (Mn 10,000-500,000, for example, polycarboxylic acid, polysulfonic acid, polyether-modified carboxylic acid, polyether), association type (Mn 10,000-500). 1,000, for example, urethane-modified polyether).
The content of (D9) is usually 10% or less, preferably 0.1 to 5%, based on the total weight of the resin composition for powder coating (Y) after addition of the additive.

Examples of the dynamic surface tension adjusting agent (D10) include acetylene glycol, fluorine-containing compound and silicone-containing compound. The dynamic surface tension adjusting agent has a function of reducing the surface tension.
The content of (D10) is usually 20% or less, preferably 0.1 to 10%, based on the total weight of the resin composition for powder coatings (Y) after addition of the additive.

  The resin composition for powder coatings (Y) of the present invention may further contain a curing accelerator (E) if necessary within a range not inhibiting the effects of the present invention. Specific examples of the curing accelerator include imidazole compounds and metal salts thereof, organic phosphine compounds, phosphonium salts, and quaternary ammonium salt compounds.

  Examples of the imidazole compound include 2-ethyl-4-methylimidazole, 1-methylimidazole, 1,2-dimethylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, and 2-heptadecylimidazole. , Alkyl imidazoles such as 2-isopropylimidazole, carbamyl alkyl-substituted imidazoles such as 1- (2-carbamylethyl) imidazole, cyanoalkyl-substituted imidazoles such as 1-cyanoethyl-2-methylimidazole, 2-phenylimidazole, 2- Aromatic substituted imidazole such as phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, alkenyl substituted imidazole such as 1-vinyl-2-methylimidazole, 1-allyl-2-ethyl-4 Allyl substituted imidazole and poly imidazole such as methylimidazole.

  Examples of the metal salt of the imidazole compound include those obtained by complexing the imidazole compound with a metal salt. Examples of the metal salt include copper, nickel, cobalt, calcium, zinc, zirconium, silver, chromium, manganese, tin, iron, titanium, antimony, aluminum and the like, chloride, bromide, fluoride, sulfate, nitrate, acetate. , Salts of malate, stearate, benzoate, methacrylate and the like.

Specific examples of the method for producing (Y) include the following methods.
A resin (A) and an amorphous resin (B) having a carboxyl group and / or a hydroxyl group are previously melt-kneaded to obtain a main agent composition (Y), a coarsely pulverized composition, a crosslinking agent (C), If necessary, one or more additives (D) are premixed, melt-kneaded and cooled to obtain a powder coating composition (Y).
Thereafter, the (Y) is pulverized and classified for particle size distribution adjustment to obtain a powder coating material. The resin (A) and the amorphous resin (B) having a carboxyl group and / or a hydroxyl group are not melt-kneaded in advance, and the crosslinking agent (C) and, if necessary, one or more additives (D) The same resin composition for powder coating (Y) may be obtained by premixing and then kneading and cooling.
The preliminary mixing step is a step in which various raw materials are charged into a mixer and preliminarily mixed. Examples of the mixer include a super mixer and a Henschel mixer.
The melt-kneading step is a step of mixing the premixed raw materials under heating and dispersing the resin (A) and the crosslinking agent (C) in the amorphous resin (B). Examples of the melt kneader include an ekurtruder and a busconyder.
In the cooling step, the melt-kneaded resin composition is formed into a sheet shape with a pressure roll and then cooled and solidified.
The pulverization step is a step of finely pulverizing to an optimum particle size distribution according to the application of the paint. Examples of the pulverizer include an atomizer, a turbo mill, and a jet mill.
The classification process for adjusting the particle size distribution is performed to remove coarse particles and / or fine particles.

  The volume average particle diameter of the powder coating material is preferably 5 to 60 μm, more preferably 15 to 40 μm, from the viewpoint of coating efficiency and coating film appearance. The volume average particle size in the examples is a value measured using a particle size distribution measuring instrument using a laser diffraction scattering method [trade name “Microtrack MT3000II particle size analyzer”, manufactured by Nikkiso Co., Ltd.] Unit: μm).

The equivalent ratio [(B) / (C)] of the non-crystalline resin (B) and the crosslinking agent (C) constituting the powder coating composition (Y) of the present invention is the coating strength and storage stability. From a viewpoint of property, Preferably it is 30 / 70-70 / 30, More preferably, it is 40 / 60-60 / 40.
The equivalent ratio [(B) / (C)] can be calculated from the sum of the acid value and the hydroxyl value of (B) and the functional group equivalent of the functional group of (C).

  The method for applying the powder coating prepared from the resin composition for powder coating (Y) to the substrate is not particularly limited. For example, the powder coating is applied to the object to be coated by spray coating, electrostatic Examples thereof include powder coating and fluidized immersion coating, and electrostatic powder coating is preferred from the viewpoint of coating efficiency.

The coated object is preferably 100 to 230 ° C., more preferably 140 to 200 ° C. from the viewpoint of coating film curability and industrial, and preferably from 60 to 60 minutes from the same viewpoint. More preferably, the coating film can be formed with a curing time of 8 to 30 minutes, particularly preferably 10 to 20 minutes.
The film thickness after curing is preferably 10 to 150 μm, more preferably 20 to 100 μm, from the viewpoint of coating effect and industrial viewpoint.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to this. In the following description, “parts” represents parts by weight and “%” represents% by weight.

The SP values (SP _a1 ) and (SP _a2 ) of the segment (a1) and the segment (a2) are calculated by the method by Fedors [Polym. Eng. Sci. 14 (2) 152, (1974)].

Production Example 1
<Synthesis of segment (a1-1)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 696 parts of sebacic acid, 424 parts of 1,6-hexanediol and 0.5 part of tetrabutoxytitanate as a condensation catalyst were placed at 170 ° C. under a nitrogen stream. And reacted for 8 hours while distilling off the water produced. Next, while gradually raising the temperature to 220 ° C., the reaction is performed for 4 hours while distilling off the generated water under a nitrogen stream, and the reaction is further performed under a reduced pressure of 0.5 to 2.5 kPa. When it became below, it took out. The taken out resin was cooled to room temperature and then pulverized into particles to obtain a segment (a1-1). The SP _a1 of the segment (a1-1) was 9.9.

Production Example 2
<Synthesis of segment (a1-2)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 813 parts of adipic acid, 691 parts of ethylene glycol, and 0.5 part of tetrabutoxy titanate as a condensation catalyst are produced at 170 ° C. under a nitrogen stream. The reaction was allowed to proceed for 8 hours while distilling off water. Next, while gradually raising the temperature to 220 ° C., the reaction was carried out for 4 hours while distilling off the generated water under a nitrogen stream, and the reaction was further carried out under a reduced pressure of 0.5 to 2.5 kPa, resulting in Mw of 5000. Removed at the time. The recovered ethylene glycol was 304 parts. The taken-out resin was cooled to room temperature and then pulverized into particles to obtain a segment (a1-2). The SP _a1 of the segment (a1-2) was 11.2.

Production Example 3
<Segment (a2-1)>
As the segment (a2-1), behenyl alcohol itself was used. SP _a2 is 9.3.

Production Example 4
<Synthesis of Resin (A-1)>
950 parts of segment (a1-1) and 19 parts of segment (a2-1) were charged into a reaction vessel equipped with a stirrer and a nitrogen introduction tube, and homogenized at 180 ° C. for 3 hours. The mixture was cooled to 100 ° C., charged with 2 parts of hexamethylene diisocyanate, and further reacted at 100 ° C. for 3 hours to obtain a resin (A-1). The SP _A of the resin (A-1) was 9.8, and Mw was 17,000.

Production Example 5
<Synthesis of Resin (A-2)>
In a reaction vessel equipped with a stirrer and a nitrogen introduction tube, 305 parts of segment (a1-2) and 18 parts of segment (a2-1) were charged and homogenized at 200 ° C. for 3 hours. The mixture was cooled to 100 ° C., 1 part of hexamethylene diisocyanate was added, and the mixture was further reacted at 100 ° C. for 3 hours to obtain a resin (A-2). The SP _A of the resin (A-2) was 11.0, and Mw was 5,000.

Comparative production example 1
<Resin (ratio A-1)>
As the resin (ratio A-1), the segment (a1-2) itself was used. SP _a1 is 11.2.

Comparative production example 2
<Resin (ratio A-2)>
Segment (a2-1) itself was used as resin (ratio A-2). SP _a2 is 9.3.

The raw materials used in the examples and their symbols are as follows.
(B-1): Hydroxyl-terminated polyester resin
[Product name "Fine Dick M-8240", manufactured by Dainippon Ink,
Hydroxyl value 30, acid value 4, softening point 120 ° C.]
(B-2): Carboxyl group-terminated polyester resin
[Product name "Fine Dick M-8962", manufactured by Dainippon Ink,
Acid value 34, softening point 112 ° C]

(C-1): Isophorone diisocyanate blocked with ε-caprolactam
[Product name "Vestagon B1530", manufactured by Evonik Co., Ltd.]
(C-2): Triglycidyl isocyanurate (TGIC)
[Product name "Araldite PT-810", manufactured by Huntsman]
(C-3): β-hydroxyalkylamide (HAA)
[Product name "Primid XL-552", manufactured by EMS-CHEMIE]

Monomer (w):
(W-1): Glycidyl methacrylate (w-2): Methyl methacrylate (w-3): Styrene organic solvent (E):
(E-1): Xylene

Filler (D1)
(D1-1): Titanium dioxide
[Product name "Taipeke CR-90", manufactured by Ishihara Sangyo Co., Ltd.]
Leveling agent (D7):
(D7-1): Acrylic polymer
[Product name "Acronal 4F", manufactured by BASF,
Tg-55 ° C., Mn 16,500]
Antifoam (D8):
(D8-1): Benzoin (antifoaming agent)

Production Example 6
<Synthesis of acrylic resin having carboxyl group (C-4)>
In a pressurizable reaction vessel, 60 parts of (E-1) was charged and heated to reflux. The pressure was increased to 0.05 MPa by blowing nitrogen, and the temperature was further raised to 150 ° C. to confirm reflux.
In a separate container, 43 parts of (w-1), 9 parts of (w-2) and 48 parts of (w-3), 3.5 parts of di-tert-butyl peroxide and (E -1) Initiator solutions in which 7 parts were compatibilized were prepared. The monomer solution and the initiator solution were added dropwise to the reaction vessel over 3 hours. After completion of the dropwise addition, the mixture was reacted for 2 hours under reflux conditions. Thereafter, the solvent was removed to obtain a glycidyl group-containing acrylic resin crosslinking agent (C-4) (Mw: 5000, SP value: 10.8, Tg: 73 ° C., epoxy equivalent: 334).

Examples 1-8, Comparative Examples 1-3
In accordance with the composition (parts) shown in Table 1, the resin (A) and the resin (B) are charged and melt-kneaded at 120 ° C. using a melt kneader / cone kneader (manufactured by Busus). A composition (X) was obtained.
Next, according to the blending composition (part) in Table 1, the obtained powder coating main component composition (X), the crosslinking agent (C), and the additive (D) were charged, and the melt kneader kneader [ The resin composition for powder coatings (Y) was obtained by melt-kneading at 120 ° C.
Each obtained resin composition for powder coatings (Y) was evaluated according to the following evaluation methods (1) to (3). The results are shown in Table 1.

[Evaluation method]
(1) Crushability Each resin composition for powder coatings was roughly pulverized and then pulverized using a pulverizer atomizer [Fuji Powder Co., Ltd.]. The obtained pulverized material (sample) was 32 mesh [aperture 500 μm], 60 mesh [aperture 250 μm], 150 mesh [aperture 105 μm], 325 mesh [aperture 44 μm], 400 mesh [aperture 37 μm]. Tyler standard sieves were stacked in order from the top, and the pulverized product obtained from the trial was placed from the top, and classified for 10 minutes using a sieve shaker low tap type [manufactured by Iida Seisakusho].
From the weight of the sample remaining on each mesh, the weight average particle size [50% particle size: D ₅₀ ] and the sharpness of particle size distribution [D ₉₀ (90% particle size) / D ₁₀ (10% particle size)] are obtained. Obtained and evaluated according to the following evaluation criteria.

<Evaluation criteria>
(1-1) D ₅₀
◎: Less than 70 μm ○: 70 μm or more, less than 75 μm Δ: 75 μm or more, less than 85 μm ×: 85 μm or more <Evaluation Criteria>
(1-2) D ₉₀ / D ₁₀
A: 2.2 or more, less than 2.5 ○: 2.5 or more, less than 2.8 Δ: 2.8 or more, less than 3.1 ×: 3.1 or more

(2) Smoothness of coating film Among the powders obtained in (1) above, those that passed through a 325 mesh Tyler standard sieve [aperture 44 μm] were airflow classifier DS-2 [Nippon Pneumatic Industry The powder coating material was obtained by classifying using a product made by Co., Ltd. and removing fine particles.
The obtained powder coating material was applied to a test steel plate [the surface of a cold rolled steel plate (SPCC-SD) of 0.5 mm × 80 mm × 150 mm defined in JIS G3141 degreasing with methanol] and a corona charging type coating gun [“ GX116 ", manufactured by Parker Rising Co., Ltd.], and the coating amount was adjusted so that the cured film thickness was 40 μm.
Next, the coated object to be coated was baked at 180 ° C. for 20 minutes to obtain a test strip with a coating film. The smoothness of the coating film of this test rope was evaluated according to the following evaluation criteria.
(2-1) Visual smoothness <Evaluation criteria>
◎: Very good ○: Good △: Slightly inferior ×: Poor

(2-2) 60 degree specular gloss The reflectance (%) of the coating film was measured by the method defined in JIS K5600-4-7 when the incident angle and the light receiving angle were 60 degrees.
<Evaluation criteria>
◎: 90% or more ○: 85% or more, less than 90% △: 80% or more, less than 85% ×: less than 80%

(3) Curability of the coating film The curability of the test sheet board with the coating film obtained in the above (2) was evaluated.
(3-1) Pencil hardness The pencil scratch test prescribed | regulated to JISK6500-5-4 was done.
(3-2) Solvent resistance The coating film was subjected to a rubbing test using xylene, and the state of the coating film was visually observed and evaluated according to the following evaluation criteria.
<Evaluation criteria>
◎: No change at all ○: Slightly changed coating surface △: Dissolved on coating surface ×: Dissolved coating and exposed substrate

  From the results of Table 1, the main component composition for powder coatings (X) of the present invention imparted excellent pulverizability to the resin composition for powder coatings and was superior to the coating film as compared with the comparative one. Obviously, it imparts smoothness and curability. .

  The main component composition for powder coatings of the present invention is excellent in pulverizing properties of the coating material, and the coating film applied to the object to be coated is excellent in smoothness, so that it is particularly suitable for coating applications such as buildings and home appliances. It is extremely useful.

Claims (9)

  A resin (A) in which two or more kinds of segments (a) are bonded by a chemical bond and an amorphous resin (B) having a carboxyl group and / or a hydroxyl group are contained. A main component composition (X) for powder coatings, comprising a segment (a1) compatible with the crystalline resin (B) and a segment (a2) incompatible with the amorphous resin (B).   The main composition for powder coatings according to claim 1, wherein the resin (A) is a crystalline resin. Glass transition point Tg ₂ (° C.) of only amorphous resin (B) and glass transition point Tg ₂ derived from amorphous resin (B) of a mixture of amorphous resin (B) and resin (A) The main ingredient composition for powder coatings according to claim 1 or 2, wherein (° C) satisfies the following relational expression (1).
Tg ₁ −Tg ₂ ≦ 15 (1) The main composition for powder coating according to any one of claims 1 to 3, wherein the glass transition point Tg _T (° C) of the main composition for powder coating (X) is 50 ° C or lower.   The segment (a1) and the segment (a2) in the resin (A) are bonded with one or more organic groups selected from the group consisting of an ester group, a urethane group, a urea group, and an amide group. The main ingredient composition for powder coatings in any one of -4. The main composition for powder coatings according to any one of claims 1 to 5, wherein the segment (a1) and the segment (a2) satisfy both of the following relational expressions (2) and (3).
| SP _a1 −SP _B | ≦ 1.9 (2)
| SP _a2 −SP _B | ≧ 1.9 (3)

[In relational expressions (2) and (3), SP _a1 represents the SP value of the segment (a1), SP _a2 represents the SP value of the segment (a2), and SP _B represents the SP value of the amorphous resin (B). ]   The main ingredient for powder coating according to any one of claims 1 to 6, wherein the weight ratio [(B) / (A)] of the amorphous resin (B) to the resin (A) is 50/50 to 98/2. Composition (X).   The resin composition for powder coatings (Y) containing the main ingredient composition for powder coatings (X) in any one of Claims 1-7, and a crosslinking agent (C).   A coating film obtained by curing the resin composition (Y) for powder coating according to claim 8.