JP3786282B2 - Thermosetting powder coating composition - Google Patents

Description

  The present invention relates to a thermosetting powder coating composition that is excellent in low-temperature curability, excellent in storage stability, and capable of forming a film excellent in various properties such as acid resistance.

  Thermosetting powder coating compositions are widely used in general metal coatings as environmentally friendly coatings that do not volatilize organic solvents into the atmosphere during coating. Among them, thermosetting powder coating compositions in which epoxy group-containing vinyl polymers and polyester resins are used as resin components can form films with excellent physical properties such as processability and solvent resistance. As a result, demand is expanding rapidly.

  Since such a thermosetting powder coating composition does not contain an organic solvent, it can be said that it is the most excellent coating composition from the viewpoint of VOC reduction. On the other hand, compared with a thermosetting solvent-based coating, A high baking temperature is required to crosslink and cure the coating composition, which is problematic in terms of energy saving and energy cost reduction.

  In addition, since there is a problem that it is difficult to apply to materials that are relatively weak to heat, such as plastic and wood, and materials that do not easily rise in temperature, it is urgent to lower the baking temperature of thermosetting powder coating compositions. It is an issue.

  Curing systems currently in practical use as thermosetting powder coating compositions include a combination of a hydroxyl group-containing polyester and a blocked isocyanate, a combination of an acid group-containing polyester and an epoxy compound, an acid group-containing polyester and triglycidyl isocyanate. A combination with nurate, a combination of an epoxy group-containing vinyl polymer and a dibasic acid, etc. are employed, and the baking condition of the thermosetting powder coating composition using them is generally about 180 ° C. . Even for epoxy group-containing vinyl polymers and dibasic acid curing systems that can be cured at relatively low temperatures, the baking temperature needs to be 140 ° C. or higher.

  On the other hand, thermosetting solvent-based paints are generally used under drying and baking conditions of 120 ° C. or lower if they are excellent in low-temperature curability, such as amino resin curing type. Therefore, on the line side in the industry, in order to replace the current thermosetting solvent-based paint with a thermosetting powder coating composition, it is necessary to set a baking furnace at a higher temperature than the existing baking conditions. Therefore, the fact that the thermosetting powder coating composition needs to be baked at a high temperature is an obstacle to replacement with an environment-friendly thermosetting powder coating composition.

  As a method for lowering the baking temperature of the thermosetting powder coating composition, use of a curing agent having excellent low-temperature curability such as an amino resin or use of a highly active catalyst can be considered. Insufficient or facilitates the solid-phase reaction, resulting in a decrease in blocking resistance of the thermosetting powder coating composition during storage, causing problems in storage stability, and cannot be put to practical use It was.

  Other conventionally known types of curing include, for example, a vinyl polymer having both an epoxy group and a hydroxyl group, an aliphatic dibasic acid, a condensate of an amino group-containing compound and an aldehyde compound, or the condensate. There is a resin composition for powder coatings containing an aminoplast obtained by etherification of the above as an essential component, and the resin composition for powder coatings requires a baking temperature of 150 ° C. (for example, Patent Documents) 1).

  Also known is a powder coating resin composition containing a resin comprising a copolymer having both a carboxylic acid alkyl ester group and a hydroxyl group, and a transesterification catalyst such as tetraisopropyl titanate or paratoluenesulfonic acid as a curing catalyst. (For example, see Patent Document 2). In the composition, a transesterification reaction between a carboxylic acid alkyl ester group and a hydroxyl group is used for the crosslinking curing reaction, but a baking temperature of 180 ° C. is required.

  In addition, although it is not research on thermosetting powder coating compositions, diphenylammonium triflate obtained using diphenylammonium and trifluoromethanesulfonic acid as a curing system capable of low-temperature curing is n-octanol or the like. Comparison of 80 to 110 ° C. in esterification of monohydric alcohol with monohydric acid such as 3-phenylpropionic acid and transesterification of monoester such as methyl 3-phenylpropionate with monohydric alcohol Have been reported to be effective in improving the reactivity under low temperature conditions (for example, Non-Patent Document 1).

JP-A-9-87552

JP-A-8-92503 Tetrahedron Letters (2000), 41 (27), 5249-5252

  However, when the above-mentioned diphenylammonium triflate is used to crosslink and cure a compound having a carboxylic acid ester group and a hydroxyl group by a transesterification reaction, the resulting coating is markedly colored. It could not be applied to a thermosetting powder coating composition. Further, in Non-Patent Document 1, there is a knowledge about a curing reaction of a compound having a large number of reactive functional groups, such as a resin used in a thermosetting powder coating composition, and a thermosetting powder coating composition. It is not described at all.

  As described above, even when trying to improve the low-temperature curability in the thermosetting powder coating composition by making full use of conventional techniques, storage stability such as blocking resistance is sacrificed, and those that are put to practical use are It was not obtained. That is, none of the conventional thermosetting powder coating compositions that can be used practically have low-temperature curability, and a high-temperature baking furnace is required for crosslinking and curing.

  For this reason, conventional thermosetting powder coating compositions are difficult to use for materials that are relatively weak against heat, such as plastic and wood, and materials that do not easily rise in temperature. Therefore, it has been difficult to replace the current thermosetting solvent-based paint.

An object of the present invention is to provide a thermosetting powder coating composition that is particularly excellent in low-temperature curability and excellent in storage stability such as blocking resistance.
Another object of the present invention is to provide a thermosetting powder capable of forming a film having excellent hardness, solvent resistance, acid resistance, bending resistance, etc. in addition to the excellent low-temperature curability and storage stability. The object is to provide a body paint composition.

  Based on the premise that the present inventors can be applied to a thermosetting powder coating composition that requires essentially good storage stability, as a result of repeated research on a curing system excellent in low-temperature curability, An organic sulfonate formed from a carboxylic acid amide compound and an organic sulfonic acid having a fluorine atom has a function of remarkably accelerating a transesterification reaction between a hydroxyl group and a carboxylic acid ester group, and is called coloring of a cured product I found no problem.

  As a result of research on the basis of this new knowledge, a polymer having a hydroxyl group and a polymer having a carboxylic acid ester group, or a polymer having both a hydroxyl group and a carboxylic acid ester group, the carboxylic acid amide compound and fluorine By using a mixture containing an organic sulfonate formed from an organic sulfonic acid having an atom, a thermosetting powder coating composition excellent in storage stability such as blocking resistance can be obtained. It has been found that a film can be formed by crosslinking and curing at a temperature much lower than that of a conventional thermosetting powder coating composition.

  Furthermore, the film formed by crosslinking and curing under low temperature conditions using the obtained thermosetting powder coating composition has a good appearance, and heat curing such as hardness, solvent resistance, acid resistance, and bending resistance. The present invention was completed by confirming that the general characteristics required for the conductive powder coating composition were also good.

  That is, the present invention relates to a thermosetting powder coating composition containing a film-forming component that can be cross-linked and cured by an ester exchange reaction between a carboxylic acid ester group and a hydroxyl group, and an ester exchange reaction catalyst. It is composed of an organic sulfonate (X) formed from an acid amide and an organic sulfonic acid having a fluorine atom, and the carboxylic acid amide is a compound represented by the following general formula (I) or in one molecule And a thermosetting powder coating composition characterized by being a compound having two or more N-alkanoyl-2,2,6,6-tetramethylpiperidin-4-yl groups.

  The present invention also provides the thermosetting powder coating composition as described above, wherein the organic sulfonate (X) has a structure represented by the following general formula (IV).

[Wherein, R 1, R 2 and R 3 each independently represents a hydrogen atom or a monovalent organic group. Further, R2 and R3 Luke to form a divalent group represented by one general formula bonded to each other (II), or, R1 and R2 are bonded total number of carbon atoms comprising the 2 mutually Either 11 substituted or unsubstituted alkylene groups may be formed .

(In the formula, R4 represents a hydrogen atom or a methyl group, and Y represents a direct bond, a methylene group, a substituted methylene group, or an oxygen atom.)
R 5 represents a monovalent organic group having a fluorine atom. ]

  Furthermore, the present invention provides a cured product obtained by coating the thermosetting powder coating composition on a substrate and curing the applied thermosetting powder coating composition.

  According to the present invention, it is possible to provide a highly practical thermosetting powder coating composition that is particularly excellent in low-temperature curability and excellent in storage stability such as blocking resistance.

  The thermosetting powder coating composition of the present invention can set conditions for crosslinking and curing at a much lower temperature than before, and can greatly reduce energy costs in the production process.

  For this reason, the thermosetting powder coating composition of the present invention is not applicable to the conventional thermosetting powder coating compositions, and is relatively difficult to increase in temperature or a member that is relatively weak against heat, such as plastic and wood. Can be used, and the application range of the environment-friendly thermosetting powder coating composition can be greatly expanded.

  In addition, the present invention is expected to accelerate the replacement of currently used thermosetting solvent-based paints with environmentally conscious thermosetting powder coating compositions in coating lines operating in the industry. it can.

Hereinafter, embodiments of the present invention will be described in detail.
First, the film-forming component that can be cross-linked and cured by transesterification between a carboxylic ester group and a hydroxyl group used in the present invention will be described.
As the film forming component, a polymer such as vinyl polymer, polyester resin or polyurethane resin having two or more hydroxyl groups and / or two or more carboxylic acid ester groups in one molecule is used as an essential component. In addition, a low molecular weight compound can be used in combination as appropriate.

  The number average molecular weight of the polymer used as the film forming component is preferably in the range of 1000 to 30000, more preferably in the range of 2000 to 10,000, and particularly preferably in the range of 2000 to 5000.

  Moreover, it is preferable that 80 weight% or more of the said film formation component is a polymer which has the number average molecular weight of the range of 1000-30000, and it is more preferable that it is 90 weight% or more.

  When the number average molecular weight and blending ratio of the polymer used as a film forming component are within the above ranges, the obtained thermosetting powder coating composition should have excellent storage stability such as blocking resistance. And a film excellent in hardness, solvent resistance, acid resistance, flex resistance and the like can be formed. Furthermore, the curability and workability of the thermosetting powder coating composition are also improved.

  Moreover, as a softening point which the film formation component used by this invention has, the range which is 50-130 degreeC is preferable, More preferably, it is the range of 90-120 degreeC. If the softening point is within such a range, the resulting thermosetting powder coating composition has good storage stability and fluidity in the molten state, and can form a film having excellent smoothness.

  More specifically, what can be used as the forming component will be described in detail. Compound (A) having two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule, two or more in one molecule The compound (B) having a hydroxyl group and having no carboxylate group, and the compound (C) having two or more carboxylate groups in one molecule and having no hydroxyl group can be exemplified. .

  The compound (A) having two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule has, for example, a number average molecular weight in the range of 1000 to 30,000, and in one molecule. The polymer (a-1) having both two or more hydroxyl groups and two or more carboxylic acid ester groups, and a number average molecular weight of less than 1000, and two or more hydroxyl groups and two in one molecule The low molecular compound (a-2) etc. which have the above carboxylic acid ester group together can be used.

  Specific examples of the compound that can be used as the polymer (a-1) have a number average molecular weight in the range of 1000 to 30000, each having two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule. And vinyl polymers, polyester resins, polyurethane resins, and the like. Among these, by using a vinyl polymer, it is possible to form a film that is particularly excellent in acid resistance.

  The vinyl polymer having two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule includes two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule, respectively. An acrylic polymer, a vinyl ester polymer, an α-olefin polymer, a fluoroolefin polymer, an aromatic vinyl polymer, and the like are included, and an acrylic polymer is particularly preferable.

  Such a vinyl polymer having two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule includes a vinyl monomer having a hydroxyl group and a vinyl monomer having a carboxylic acid ester group. Various known and commonly used methods using other monomers based on vinyl groups that do not have other hydroxyl groups and carboxylic acid ester groups that can be used as essential monomers and can be copolymerized with these monomers. Can be manufactured by applying

  That is, the desired vinyl polymer can be produced by radical polymerization, ionic polymerization, or photopolymerization according to conventional methods such as solution polymerization, solution dispersion polymerization, bulk polymerization, etc. It is simple to use radical polymerization.

  The obtained vinyl polymer is used in a solid state when the solvent is removed if necessary and the thermosetting powder coating composition of the present invention is produced.

  Moreover, among the vinyl monomers having a hydroxyl group that are used for general purposes, many of them also have a carboxylic acid ester group, and a vinyl monomer having both a hydroxyl group and a carboxylic acid ester group as a monomer. When a monomer is used, a vinyl polymer having two or more hydroxyl groups and two or more carboxylic acid ester groups in the target molecule can be produced even if the monomer is homopolymerized. be able to.

  Among the vinyl monomers having a hydroxyl group, those having no carboxylic acid ester group include N-methylol (meth) acrylamide, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 2-hydroxyethyl allyl ether. Etc. can be used.

  Examples of vinyl monomers having both a hydroxyl group and a carboxylic acid ester group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. And ethyl-α-hydroxymethyl acrylate. Furthermore, a vinyl monomer having a hydroxyl group obtained by reacting these various hydroxyl group-containing vinyl monomers with ε-caprolactone can also be used.

  In addition to the vinyl monomer having both the hydroxyl group and the carboxylic acid ester group, methyl (meth) acrylate, ethyl (meth) can be used as the vinyl monomer having the carboxylic acid ester group. Various alkyl (meth) acrylates having an alkyl group having 1 to 22 carbon atoms, such as acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate;

Various alicyclic alkyl (meth) acrylates such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate;

Various aralkyl (meth) acrylates such as benzyl (meth) acrylate and phenethyl (meth) acrylate;

Various alkoxyalkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 1-methoxyethyl (meth) acrylate, 1-ethoxyethyl (meth) acrylate;

Various halogen-substituted alkyls such as 2-chloroethyl (meth) acrylate, 2-fluoroethyl (meth) acrylate, 2,2-difluoroethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, etc. ) Acrylate;

Various alkyl esters of crotonic acid such as methyl crotonic acid and ethyl crotonic acid;

Dialkyl esters of various unsaturated dicarboxylic acids such as dimethyl malate, dibutyl malate, dimethyl fumarate, dibutyl fumarate, dimethyl itaconate, dibutyl itaconate;

Various carboxylic acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate;

Various unsaturated carboxylic acids such as 2-carboxyethyl (meth) acrylate;

Monovinyl esters of various saturated dicarboxylic acids such as succinic acid, adipic acid, sebacic acid;

Various half esters of various unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and monohydric alcohols;

Carboxyl group-containing monomers that are addition reaction products of hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate and various acid anhydrides such as succinic anhydride and phthalic anhydride, and 2-phosphorylate Examples thereof include various monomers having an acid group other than a carboxyl group such as ruoxyethyl (meth) acrylate.

  Moreover, as a vinyl monomer which does not have the said other copolymerizable hydroxyl group and carboxylic ester group which can be used when manufacturing the vinyl polymer as a polymer (a-1), styrene, various aromatic vinyl monomers such as p-tert-butylstyrene, α-methylstyrene, vinyltoluene;

Various (meth) acrylamides such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; various cyano group-containing vinyl-based monomers such as (meth) acrylonitrile and crotononitrile Mer;

Various haloolefins such as vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinyl chloride, vinylidene chloride;

Various α-olefins such as ethylene, propylene, isobutylene and 1-butene; various unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, and various simple units having acid groups other than carboxyl groups such as vinyl sulfonic acid. Mer;

Examples thereof include alkyl vinyl ethers such as ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, and cyclohexyl vinyl ether.

  Next, it has a number average molecular weight in the range of 1000 to 30000 that can be used as the polymer (a-1), and has two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule. As the polyester resin, a known method using a polyvalent carboxylic acid and a polyhydric alcohol as described below in such a ratio that the hydroxyl group of the polyhydric alcohol is excessive with respect to the carboxyl group of the polyvalent carboxylic acid. What is obtained by condensing with can be used.

  In this case, usable polyvalent carboxylic acids include oxalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid and the like; terephthalic acid, isophthalic acid, orthophthalic acid Acid, aromatic dicarboxylic acid such as 2,6-naphthalenedicarboxylic acid; 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, alicyclic dicarboxylic acid such as hexahydrophthalic anhydride, tetrahydrophthalic anhydride; Examples thereof include unsaturated dicarboxylic acids such as acid, fumaric acid and itaconic acid; trifunctional or higher carboxylic acids such as trimellitic acid and pyromellitic acid, and hydroxycarboxylic acids such as P-oxybenzoic acid and tartaric acid.

  Examples of the polyhydric alcohol that can be used include ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 1,4-butylene glycol, 1 , 3-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, 1,4-cyclohexanedimethanol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct , Cyclohexanedimethanol, hydrogenated bisphenol A, ethylene oxide adduct of hydrogenated bisphenol A, propylene oxide adduct of hydrogenated bisphenol A, glycerin, trimethylolpropane, tri Hydroxymethyl aminomethane, pentaerythritol, and dipentaerythritol.

  A polyurethane resin having a number average molecular weight in the range of 1000 to 30000 that can be used as the polymer (a-1) and having both two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule. Will be described. The polyurethane resin can be produced by applying a known polyurethane resin production method.

  For example, by reacting a polyol and a polyisocyanate such as an acrylic polyol or a polyester polyol having two or more carboxylic acid ester groups with a condition in which the hydroxyl group of the polyol is excessive with respect to the isocyanate group of the polyisocyanate. The polyurethane resin can be obtained.

  Examples of polyisocyanates that can be used in this case include diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate and hydrogenated products thereof, and tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, Examples thereof include polyisocyanates such as isophorone diisocyanate and lysine diisocyanate.

  The number of hydroxyl groups and carboxylic acid ester groups possessed by the polymer (a-1) is determined based on the balance between curability and stability of the resulting thermosetting powder coating composition. The total amount of hydroxyl groups and carboxylic acid ester groups per gram is preferably in the range of 0.1 mol to 8.6 mol, and more preferably in the range of 0.3 mol to 8.6 mol.

  The polymer (a-1) used in the present invention has two or more hydroxyl groups and two or more carboxylic acid ester groups in one molecule, and is produced by a known method as described above. In the polymer (a-1), a compound having one hydroxyl group and / or one carboxylic acid ester group is usually mixed in one molecule, but the hydroxyl group and the carboxylic acid ester group are contained in one molecule. As long as the main component is a compound having two or more compounds, the object of the present invention can be achieved without causing a problem.

  In addition to the polymer (a-1) described above, the thermosetting powder coating composition of the present invention has a number average molecular weight of less than 1000, and two or more hydroxyl groups and two or more hydroxyl groups in one molecule. A low molecular compound (a-2) having a carboxylic acid ester group can also be used in combination.

  Examples of such low molecular compounds (a-2) that can be used include dihydroxyalkane dicarboxylic acid diesters such as dimethyl dihydroxymalonate and diethyl dihydroxymalonate; dihydroxyalkene dicarboxylic acids such as dimethyl dihydroxyfumarate and diethyl dihydroxyfumarate Diesters; Dihydroxy such as dimethyl 2,5-dihydroxyterephthalate, diethyl 2,5-dihydroxyterephthalate, dimethyl 2,5-dihydroxy-1,4-benzenediacetate, diethyl 2,5-dihydroxy-1,4-benzenediacetate Aromatic dicarboxylic acid diesters and the like can be mentioned.

  These are diesters of various dihydroxydicarboxylic acids and alkanols such as dihydroxyalkane dicarboxylic acid, dihydroxyalkene dicarboxylic acid, and dihydroxy aromatic dicarboxylic acid.

  In addition to these, diesters of these dihydroxydicarboxylic acids with various substituted alkanols can also be used.

  Examples of the substituted alkanol include various alkoxy group-substituted alkanols such as 2-methoxyethanol, 2-methoxypropanol, and 3-methoxypropanol; 2-chloroethanol, 2-fluoroethanol, 2,2,2-trifluoroethanol, and the like And various carboxylic acid ester-substituted alkanols such as glycolic acid methyl ester, lactate ethyl ester, hydroxypropionic acid methyl ester, malic acid dimethyl ester, and the like, and a thermosetting powder coating composition obtained. Can be used as long as the storage stability (anti-blocking property) is not impaired.

  Next, a compound (B) which has two or more hydroxyl groups in one molecule and does not have a carboxylic ester group, which can be used as a film forming component constituting the thermosetting powder coating composition of the present invention. Will be described. As the compound (B), for example, a polymer having a number average molecular weight in the range of 1000 to 30000, having two or more hydroxyl groups in one molecule, and having no carboxylic ester group (b- 1) and a low molecular compound (b-2) having a number average molecular weight of less than 1000 and having two or more hydroxyl groups in one molecule and having no carboxylic ester group it can.

  As said polymer (b-1) which can be used as this compound (B), it has a number average molecular weight of the range of 1000-30000, respectively, and has 2 or more hydroxyl groups in 1 molecule, Examples thereof include vinyl polymers, polyurethane resins, polyether resins and the like that do not have a carboxylic acid ester group.

  The vinyl polymer that can be used as the polymer (b-1) is a homopolymer of a vinyl monomer having a hydroxyl group and not having a carboxylic acid ester group, or It can be obtained by copolymerizing with another vinyl monomer having no hydroxyl group and carboxylic acid ester group copolymerizable therewith.

  Examples of vinyl monomers having a hydroxyl group and not having a carboxylic acid ester group that can be used in this case include cyclohexyl vinyl ether, N-methylol (meth) acrylamide, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl. Examples include vinyl ether and 2-hydroxyethyl allyl ether.

  These and other vinyl monomers that do not have copolymerizable hydroxyl groups and carboxylic acid ester groups can be used when producing the vinyl polymer as the polymer (a-1). The vinyl-type monomer which does not have the other hydroxyl group and carboxylic ester group which were illustrated as above can be used.

  In order to produce a vinyl polymer that can be used as the compound (B) using these vinyl monomers, when producing the vinyl polymer as the polymer (a-1), Similarly, a known and usual polymerization method can be applied, and the solution radical polymerization method is the simplest.

  Further, the obtained vinyl polymer is used in a solid state when the solvent is removed as necessary and the thermosetting powder coating composition of the present invention is produced.

  Further, the polymer (b-1) other than the vinyl polymer such as polyurethane resin and polyether resin which can be used as the above-mentioned compound (B) is produced by a known and usual method such as a solution reaction method or a solid layer reaction method. However, when the solvent is used, the polymer is obtained in a solid state when the thermosetting powder coating composition of the present invention is produced by removing the solvent. use.

  A polyurethane having a number average molecular weight in the range of 1000 to 30000 and having two or more hydroxyl groups in one molecule and having no carboxylate group, which can be used as the polymer (b-1). The resin can be produced by various known methods. For example, a compound obtained by reacting a polyisocyanate with a compound having at least two hydroxyl groups in one molecule at a ratio such that the hydroxyl groups of the compound are excessive with respect to the isocyanate groups of the polyisocyanate. Can be used.

  Examples of the polyisocyanate that can be used in this case include the polyisocyanates exemplified as those that can be used when obtaining the polyurethane resin as the polymer (a-1).

  Moreover, as a compound which has at least 2 hydroxyl group in 1 molecule which can be used when manufacturing the said polyurethane resin, it illustrates as what can be used in obtaining the polyester resin as an above described polymer (a-1). In addition to the polyhydric alcohols, there may be mentioned polymers such as polyethylene glycol and polypropylene glycol which have at least two hydroxyl groups in one molecule and have no carboxylic acid ester group.

  Examples of the polyether resin that can be used as the polymer (b-1) include polyethylene glycol and polypropylene glycol having a number average molecular weight in the range of 1000 to 30000.

  The hydroxyl group possessed by the polymer (b-1) having a number average molecular weight in the range of 1000 to 30000 as described above, having two or more hydroxyl groups in one molecule, and having no carboxylic acid ester group The amount is preferably in the range where the hydroxyl value is from 10 to 400, and more preferably in the range from 20 to 300.

  In addition to the polymer (b-1) described above, the thermosetting powder coating composition of the present invention has a number average molecular weight of less than 1000, and has two or more hydroxyl groups in one molecule. A low molecular compound (b-2) having no carboxylic acid ester group can also be used in combination.

  Examples of the low molecular weight compound (b-2) include various alkane diols such as ethylene glycol, propylene glycol, butanediol, hexanediol, and dodecanediol; various cycloalkanediols such as cyclohexanediol and methylhexanediol; and trimethylolpropane. These diols, lactone adducts of these diols, and the like can be used, and can be used as long as the storage stability (blocking resistance) of the resulting thermosetting powder coating composition is not impaired.

  Next, compound (C) which has two or more carboxylic acid ester groups in one molecule and does not have a hydroxyl group, which can be used as a film forming component constituting the thermosetting powder coating composition of the present invention Will be described. As the compound (C), for example, a polymer having a number average molecular weight in the range of 1000 to 30000, having two or more carboxylic acid ester groups in one molecule, and having no hydroxyl group (c- 1) and a polyvalent carboxylic acid ester compound (c-2) having a number average molecular weight of less than 1000 and having no hydroxyl group can be used.

  The polymer (c-1) is a vinyl polymer having a number average molecular weight in the range of 1000 to 30000, having two or more carboxylic acid ester groups in one molecule, and having no hydroxyl group. Polyester resin or the like can be used.

  Among these, the vinyl polymer has a carboxylate group and is homopolymerized with a vinyl monomer having no hydroxyl group, or the monomer can be copolymerized with other monomers. It is obtained by copolymerizing with a vinyl monomer having no hydroxyl group and carboxylic ester group.

  At that time, the vinyl monomer having a carboxylic acid ester group and not having a hydroxyl group has already been exemplified as being usable when producing a vinyl polymer as the polymer (a-1). A vinyl monomer having a carboxylic acid ester group other than the vinyl monomer having both the hydroxyl group and the carboxylic acid ester group can be used.

  Moreover, as the vinyl monomer having no other hydroxyl group and carboxylic acid ester group copolymerizable with these various vinyl monomers, the vinyl polymer as the polymer (a-1) is used. The vinyl monomer which does not have the other hydroxyl group and carboxylic acid ester group which were illustrated as what can be used when manufacturing this can be used.

  In order to produce a vinyl polymer that can be used as the compound (C) using these vinyl monomers, the vinyl polymer as the polymer (a-1) is produced. Similarly, a known and usual polymerization method can be applied, and the solution radical polymerization method is the simplest.

  Further, the obtained vinyl polymer is used in a solid state when the solvent is removed as necessary and the thermosetting powder coating composition of the present invention is produced.

  Polyester having a number average molecular weight in the range of 1000 to 30000 and having two or more carboxylic acid ester groups in one molecule and not having a hydroxyl group, which can be used as the polymer (c-1). As the resin, a ratio in which the carboxyl group of the polyvalent carboxylic acid is excessive with respect to the hydroxyl group of the polyhydric alcohol so that no hydroxyl group remains in the obtained polyester resin as the polyvalent carboxylic acid and the polyhydric alcohol. And a product obtained by condensation by a known method can be used.

  Under the present circumstances, as said polyhydric carboxylic acid or polyhydric alcohol, the polyhydric carboxylic acid and polyhydric alcohol which were already illustrated as what can be used when manufacturing the polyester resin as said polymer (a-1) are respectively mentioned. Can be used.

  Inclusion of the carboxylic acid ester group of the polymer (c-1) having a number average molecular weight in the range of 1000 to 30000 and having two or more carboxylic acid ester groups in one molecule and no hydroxyl group The amount is preferably in the range of 0.2 to 12.0 moles per 1,000 grams of polymer, more preferably 0.4 to 10 moles.

  In addition to the polymer (c-1) described above, the thermosetting powder coating composition of the present invention has a polycarboxylic acid ester compound (c) having a number average molecular weight of less than 1000 and having no hydroxyl group. -2) can also be used in combination.

  Examples of the polyvalent carboxylic acid ester compound (c-2) include various alkyl alkanedicarboxylates such as dimethyl oxalate, diethyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl adipate, and dimethyl sebacate. Esters; various polycarboxylic acid alkyl esters such as trimethyl propanetricarboxylate and tetramethyl butanetetracarboxylate; various alkenedicarboxylic acid alkyl esters such as dimethyl maleate and dimethyl phthalate; dimethyl phthalate, diethyl phthalate, and phthalic acid Various aryl dicarboxylic acid alkyl esters such as dibutyl, dimethyl isophthalate, dimethyl terephthalate, dibutyl terephthalate; trimellitic acid trimethyl ester, pyromellitic acid tetramethyl ester How the various aryl polycarboxylic acid alkyl esters and the like.

  These are alkyl esters obtained from various polyvalent carboxylic acids and alkanols. In addition to these, esters of these various polyvalent carboxylic acids and substituted alkanols can also be used.

  Examples of the substituted alkanol that can be used in this case include various alkoxy group-substituted alkanols such as 2-methoxyethanol, 2-methoxypropanol, and 3-methoxypropanol; 2-chloroethanol, 2-fluoroethanol, 2,2,2-triol, and the like. Various halogen-substituted alkanols such as fluoroethanol; various carboxylic acid ester-substituted alkanols such as glycolic acid methyl ester, lactate ethyl ester, hydroxypropionic acid methyl ester, malic acid dimethyl ester, and the like. It can be used as long as the storage stability (blocking resistance) of the body coating composition is not impaired.

Next, the transesterification catalyst constituting the present invention will be described.
In the present invention, an organic sulfonate (X) formed from a carboxylic acid amide and an organic sulfonic acid having a fluorine atom is used as the transesterification catalyst, and other known catalysts can be used in combination as necessary. Such an organic sulfonate (X) has a function of promoting a transesterification reaction between a hydroxyl group and a carboxylic acid ester group of the film-forming component constituting the thermosetting powder coating composition of the present invention which has already been described. Have

  The organic sulfonate (X) is a reaction product of a carboxylic acid amide compound and an organic sulfonic acid having a fluorine atom, and the carboxylic acid amide group of the carboxylic acid amide compound and the organic sulfonic acid having a fluorine atom are It is a compound having at least one structure in which one sulfonic acid group is bonded in a molar ratio of 1: 1.

  As the carboxylic acid amide compound that can be used in producing the organic sulfonate (X), a known compound having at least one carboxylic acid amide group in one molecule can be used. Typical examples thereof include compounds represented by the following general formula (I), or compounds having two or more N-alkanoyl-2,2,6,6-tetramethylpiperidin-4-yl groups in one molecule. Is mentioned.

[Wherein, R 1, R 2 and R 3 each independently represents a hydrogen atom or a monovalent organic group. Further, R2 and either R3 form a divalent group represented by one general formula bonded to each other (II), or the total number of carbon atoms R1 and R2 is bonded to each other 2 to 11 Or a substituted or unsubstituted alkylene group may be formed .

(In the formula, R 4 represents a hydrogen atom or a methyl group, and Y represents a direct bond, a methylene group, a substituted methylene group, or an oxygen atom. )]

  Regarding R1, R2, and R3 constituting the carboxylic acid amide compound represented by the general formula (I), specific examples of the monovalent organic group include substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted Or an unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, an alkadienyl group, an oxygen atom or a sulfur atom. Examples include heterocyclic residues constituting a part of the ring.

  When these organic groups have a substituent, examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, cyano group, hydroxyl group, alkoxy group, carboxyl group, alkoxycarbonyl group, carboxylic acid Various atomic groups such as an amide group and an aryloxycarbonyl group can be mentioned.

  Next, specific examples of the divalent group represented by the general formula (II) include tetramethylene group, pentamethylene group, 3-oxa-1,5-pentylene group, 1,1,4,4-tetramethyl. Tetramethylene group, 1,1,5,5-tetramethylpentamethylene group, 3-hydroxy-1,1,5,5-tetramethylpentamethylene group, 3-methoxy-1,1,5,5-tetramethyl Pentamethylene group, 3-acetoxy-1,1,5,5-tetramethylpentamethylene group, 3-propionyloxy-1,1,5,5-tetramethylpentamethylene group, 1,1,5,5-tetra Examples thereof include a methyl-3-oxa-1,5-pentylene group.

  Next, in the general formula (I), R1 and R2 are bonded to each other to form a substituted or unsubstituted alkylene group having 2 to 11 total carbon atoms.

  Specific examples of the unsubstituted alkylene group having 2 to 11 carbon atoms in total include ethylene group, propylene group, trimethylene group, (1-methyl) trimethylene group, (2-methyl) trimethylene group, tetramethylene group, (1-methyl) trimethylene group, (2-methyl) tetramethylene group, pentamethylene group, undecamethylene group and the like can be mentioned.

  Specific examples of the substituted alkylene group having 2 to 11 carbon atoms in total include substituted ethylene groups such as a chloroethylene group, a hydroxyethylene group, a carboxyethylene group, and a methoxycarbonylethylene group;

Substituted propylene groups such as 2-carboxypropylene group, 2-methoxycarbonylpropylene group, 1-chloropropylene group, 1-hydroxypropylene group, 1-methoxycarbonylpropylene group;

Substitution of (1-chloro) trimethylene group, (1-cyano) trimethylene group, (2-hydroxy) trimethylene group, (1-carboxy) trimethylene group, (1-methoxy) trimethylene group, (1-methoxycarbonyl) trimethylene group, etc. A trimethylene group;

(1-chloro) tetramethylene group, (2-chloro) tetramethylene group, (1-cyano) tetramethylene group, (2-hydroxy) tetramethylene group, (1-carboxy) tetramethylene group, (1-methoxy) tetra A substituted tetramethylene group such as a methylene group, (1-methoxycarbonyl) tetramethylene group, (2-methoxycarbonyl) tetramethylene group;

Substituted pentamethylene groups such as (1-chloro) pentamethylene group, (2-cyano) pentamethylene group, (1-methoxy) pentamethylene group, (1-methoxycarbonyl) pentamethylene group;

(1-chloro) undecamethylene group, (2-cyano) undecamethylene group, (1-hydroxy) undecamethylene group, (1-carboxy) undecamethylene group, (2-carboxy) undecamethylene group, ( Examples thereof include substituted undecamethylene groups such as 1-methoxy) undecamethylene group, (1-methoxycarbonyl) undecamethylene group, and (2-methoxycarbonyl) undecamethylene group.

  Among the substituted or unsubstituted alkylene groups having 2 to 11 total carbon atoms formed by bonding R1 and R2 listed above, various substituted or unsubstituted trimethylene groups, A substituted or unsubstituted pentamethylene is preferable, and a trimethylene group and a pentamethylene group are more preferable. As the carboxylic acid amide compound forming the organic sulfonate (X), N-methyl-2-pyrrolidone is particularly preferable because the action of the organic sulfonate (X) as a curing catalyst is particularly excellent.

  Next, two or more N-alkanoyl-2,2,6,6-tetramethylpiperidin-4-yl per one molecule as described above, which can be used as a carboxylic acid amide compound for forming an organic sulfonate (X) The compound having a group will be described. Typical examples of the alkanoyl group contained in such a compound include an acetyl group, a propanoyl group, an isobutanoyl group, and a 2-ethylhexanoyl group.

  Specific examples of the compound having an N-2,2,6,6-tetramethylpiperidin-4-yl group having an alkanoyl group include bis (1-acetyl-2,2,6,6-tetramethylpiperidine- 4-yl) adipate, bis (1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, bis (1-propanoyl-2,2,6,6-tetramethylpiperidine-4- Yl) adipate, bis (1-isobutanoyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate and the like.

  Next, the organic sulfonic acid which has a fluorine atom which can be used when manufacturing organic sulfonate (X) is demonstrated.

  The organic sulfonic acid having a fluorine atom refers to a compound having a sulfonic acid group bonded to an organic group having a fluorine atom as a substituent. As the organic sulfonic acid, either a monovalent acid or a divalent or higher acid can be used. From the viewpoint of the solubility of the obtained organic sulfonate (X), 1 represented by the following general formula (III) Particularly preferred is a divalent acid.

(In the formula, R5 represents a monovalent organic group having a fluorine atom.)

  Specific examples of R5, which is a monovalent organic group having a fluorine atom, contained in the monovalent acid represented by the general formula (III), each have a fluorine atom and have 1 to 20 carbon atoms. An alkyl group, a cycloalkyl group, a cycloalkenyl group, an aralkyl group, an aryl group, an alkenyl group, an alkadienyl group, a heterocyclic residue in which an oxygen atom or a sulfur atom constitutes a part of the ring, and the like. A part or all of the hydrogen atoms contained in these organic groups may be substituted with fluorine atoms.

  Particularly preferred as R5 is an organic group having two fluorine atoms at the α-position represented by the following formula (V) from the viewpoint of the catalytic activity of the organic sulfonate (X).

(In the formula, R6 represents a hydrogen atom, a fluorine atom, or a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms.)

  Specific examples of the substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms as R6 contained in the general formula (V) include an alkyl group, a cycloalkyl group, and an alkenyl group. When R6 is a hydrocarbon group having a substituent, examples of the substituent include halogen atoms such as fluorine atom, chlorine atom and bromine atom, cyano group, alkoxycarbonyl group and alkoxy group.

  Among these, since the action of the organic sulfonate (X) as a curing catalyst is particularly excellent, an alkane sulfonic acid having a fluorine atom at the 1-position is preferable, and trifluoromethane sulfonic acid is particularly preferable.

  The organic sulfonate (X) used in the present invention is formed from the above-described carboxylic acid amide compound represented by the general formula (I) and the organic sulfonic acid having a fluorine atom represented by the general formula (III). Those having a structure represented by the general formula (IV) are preferred. Among these, N-methyl-2-pyrrolidone trifluoromethanesulfonate is most preferable because the action of the organic sulfonate (X) as a curing catalyst is particularly excellent.

  When the carboxylic acid amide compound has one carboxylic acid amide group, the resulting organic sulfonate (X) contains one salt structure contained in the above general formula (IV) per molecule. Is contained. When the carboxylic acid amide compound has two or more carboxylic acid amide groups, the resulting organic sulfonate (X) has one molecule according to the use ratio of the carboxylic acid amide compound and the organic sulfonic acid. One or more salt structures contained in the above general formula (IV) are contained therein.

Next, the manufacturing method of organic sulfonate (X) used by this invention is demonstrated.
The organic sulfonate (X) can be produced by reacting the aforementioned carboxylic acid amide compound with an organic sulfonic acid having a fluorine atom.

  The use ratio of each raw material in this case is preferably such that the molar ratio of the carboxylic acid amide group of the carboxylic acid amide compound to the sulfonic acid group of the organic sulfonic acid having a fluorine atom is from 10: 1 to 1:10. A range of 5: 1 to 1: 5 is more preferable, and a range of 1.5: 1 to 1: 1.5 is particularly preferable.

  Since this reaction is exothermic, it is preferably carried out under cooling. The reaction temperature is preferably about 0 to 50 ° C., more preferably 0 ° C. to room temperature.

  When the carboxylic acid amide or organic sulfonic acid is in a solid, powder, or crystal form, the reaction can be carried out using a solvent. As the solvent used in that case, a solvent that does not react with organic sulfonic acid is suitable.

  As a reaction method, an organic sulfonic acid may be added to the carboxylic acid amide, or a carboxylic acid amide may be added to the organic sulfonic acid. Moreover, both components can also be made to react in a solvent.

  Since the reaction is a kind of neutralization reaction, the reaction time may be about 10 minutes to several hours.

  After completion of the reaction, the produced organic sulfonate (X) may be isolated by a generally used isolation method. That is, when the organic sulfonate (X) is precipitated insoluble in the solvent, it may be filtered off, and when dissolved in the solvent, the target organic can be obtained by a desolvation method or a precipitation method. Sulfonate (X) can be obtained. If necessary, the target salt can be purified by various methods such as a solvent washing method, a recrystallization method, and a reprecipitation method.

Below, the specific compounding ratio of each film forming component and organic sulfonate (X) constituting the thermosetting powder coating composition of the present invention will be described.
First, when the thermosetting powder coating composition of the present invention contains two components of the compound (A) and the organic sulfonate (X), the compound (A) and the organic sulfonate (X) The blending ratio of is preferably in the range of 0.3 to 60 mmol, more preferably in the range of 0.35 to 50 mmol of organic sulfonate (X) with respect to 100 g of compound (A).

  Next, the case where the thermosetting powder coating composition of the present invention contains three components of the compound (B), the compound (C) and the organic sulfonate (X) will be described.

  In this case, regarding the blending ratio of the compound (B) and the compound (C), the ratio of the equivalent of the hydroxyl group that the compound (B) has to the equivalent of the carboxylic acid ester group that the compound (C) has is the ratio between the former and the latter. A range of 1: 0.1 to 1:10 in terms of equivalent ratio is preferable, and a range of 1: 0.2 to 1: 5 is more preferable. In addition, the organic sulfonate (X) is preferably in a range of 0.3 to 60 mmol, more preferably 0.35 to 50, with respect to 100 g of the total amount of both components (B) and (C). The range is millimolar.

  From the viewpoint of storage stability of the resulting thermosetting powder coating composition, at least one of the compound (B) and the compound (C) is mainly a polymer having a number average molecular weight in the range of 1000 to 30000. It is preferable to be a component.

  Next, the case where the thermosetting powder coating composition contains four components of compound (A), compound (B), compound (C) and organic sulfonate (X) will be described. In this case, regarding the blending ratio of the compound (B) and the compound (C), the ratio of the equivalent of the hydroxyl group that the compound (B) has to the equivalent of the carboxylic acid ester group that the compound (C) has is the ratio between the former and the latter. A range of 1: 0.1 to 1:10 in terms of equivalent ratio is preferable, and a range of 1: 0.2 to 1: 5 is more preferable.

  Moreover, the compounding quantity of a compound (A) is not restrict | limited in particular, In addition to said compound (B) and a compound (C), it can mix | blend in arbitrary ratios. The organic sulfonate (X) component is preferably in a range of 0.3 to 60 mmol with respect to 100 grams of the total amount of these three components of compound (A), compound (B), and compound (C), More preferably, it is the range which is 0.35-50 mmol.

  Next, a method for producing the thermosetting powder coating composition of the present invention using each component will be described. In order to produce the thermosetting powder coating composition of the present invention, various known and commonly used methods can be applied.

  For example, in order to obtain the desired thermosetting powder coating composition from the aforementioned compound (A), compound (B), compound (C), and organic sulfonate (X), raw materials are appropriately selected and further required Depending on the level, a light stabilizer such as an ultraviolet absorber, a hindered amine type light stabilizer, etc., and various known materials such as antioxidants, pigments, pigment dispersants, etc. are mixed and melt kneaded. Thereafter, a thermosetting powder coating composition can be produced by a mechanical pulverization method of further pulverizing.

  The thermosetting powder coating composition of the present invention can also be produced by a spray drying method in which a solution containing the various raw materials described above is prepared and the solution is spray dried.

  The thermosetting powder coating composition of the present invention can be used as it is as a clear thermosetting powder coating composition, or as a thermosetting powder coating composition colored by blending pigments. You can also.

  The thermosetting powder coating composition of the present invention can also be used in a form containing various known and conventional curing agents within the range not impairing the characteristics and effects of the present invention.

  At that time, as the curing agent, those having reactivity with a hydroxyl group can be used. For example, aromatic diisocyanates such as tolylene diisocyanate, aliphatic diisocyanates such as hexamethylene diisocyanate, or alicyclic diisocyanates such as isophorone diisocyanate. Various polyisocyanates such as;

A prepolymer having various isocyanate groups or a prepolymer having a blocked isocyanate group, which is derived from the polyisocyanate;

  Examples include various amino resins such as melamine resin and urea resin, silicon resin and epoxy resin.

  The thermosetting powder coating composition of the present invention is coated on a substrate to be coated by a known and conventional method, and then cured by crosslinking to form a cured coating film (film) on the substrate to be coated. Thus, a cured product of the target thermosetting powder coating composition can be provided.

  Examples of the substrate to be coated include various metal materials or metal products such as iron, aluminum, stainless steel, tin plate, tin plate, and surface treatment such as chemical conversion treatment, zinc phosphate treatment, and chromate treatment. And those subjected to electrodeposition coating, tiles, glass, various inorganic building materials, heat-resistant plastics, and wood.

  More specifically, automobile body or automobile (for) parts, motorcycle or two-wheeled vehicle (for) parts, various building materials such as gates or fences, various interior and exterior materials such as aluminum sashes, iron or non-ferrous such as aluminum wheels Examples include metal parts, plastic products, and various woodworking products.

Next, the present invention will be described with reference examples, examples and comparative examples.
The hydroxyl value, acid value, softening point, and number average molecular weight of each sample were determined by the following methods.
[Hydroxyl value]; Dissolve the sample in a mixed solution of acetic anhydride and pyridine, heat and reflux at 100 ° C. for 1 hour, acetylate the hydroxyl group, add ion-exchanged water, and further heat and reflux, then cool. It was determined by back titration with a toluene / methanol solution of potassium hydroxide.

  [Acid Value] Obtained by dissolving a sample in cyclohexanone and titrating with a 0.1 N potassium hydroxide methanol solution.

  [Softening point]; Using a ring and ball type automatic softening point tester (manufactured by Meihosha Mfg. Co., Ltd.) The temperature when dropped was measured (unit: ° C).

  [Number average molecular weight]: Tetrahydrofuran was measured as an eluent by liquid chromatography using a column TSKgel G5000HXL, G4000HXL, G3000HXL, and G2000HXL manufactured by Tosoh Corporation.

Reference Example 1 [Preparation Example of Hydroxyl and Carboxylic Acid Ester Group Combined Vinyl Polymer (A-1)]
A reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel and a nitrogen gas introduction tube was charged with 100 parts by weight of xylene and heated to 135 ° C. under a nitrogen atmosphere.
Next, at the same temperature, 30 parts by weight of styrene, 27 parts by weight of methyl methacrylate, 18 parts by weight of butyl acrylate, 35 parts by weight of 2-hydroxypropyl methacrylate, and tert-butyl peroxy-2-ethylhexanoate (hereinafter referred to as TBO). .) A mixture of 3 parts by weight was added dropwise over 6 hours.

  After completion of the dropwise addition, the reaction solution was held at the same temperature for 15 hours to complete the reaction. Further, the obtained polymer solution was kept under a reduced pressure of about 20 Torr to remove xylene. A vinyl polymer (A-1) having a number average molecular weight of 2500, a softening point of 111 ° C., and a hydroxyl value of 148 was obtained.

Reference Example 2 [Preparation Example of Hydroxyl and Carboxylic Ester Group Combined Vinyl Polymer (A-2)]
In a reaction vessel similar to that of Reference Example 1, 100 parts by weight of xylene was charged and heated to 135 ° C. in a nitrogen atmosphere.
Next, at the same temperature, 30 parts by weight of styrene, 28 parts by weight of methyl methacrylate, 17 parts by weight of butyl acrylate, “Placcel FM-1” (trade name, manufactured by Daicel Chemical Industries, Ltd., ε-caprolactam adduct of 2-hydroxyethyl methacrylate ) A mixture consisting of 25 parts by weight and 2.4 parts by weight of TBO was added dropwise over 6 hours.

  After completion of the dropwise addition, the reaction solution was held at the same temperature for 15 hours to complete the reaction. Further, the obtained polymer solution was kept under a reduced pressure of about 20 Torr to remove xylene. A vinyl polymer (A-2) having a number average molecular weight of 2000, a softening point of 96 ° C., and a hydroxyl value of 57 was obtained.

Reference example 3 [Preparation example of hydroxyl group and carboxylic acid ester group combined vinyl polymer (A-3)]
In a reaction vessel similar to that of Reference Example 1, 100 parts by weight of xylene was charged and heated to 135 ° C. in a nitrogen atmosphere.
Next, at the same temperature, a mixture composed of 46 parts by weight of styrene, 26 parts by weight of dibutyl fumarate, 28 parts by weight of 2-hydroxypropyl methacrylate, and 4 parts by weight of TBO was added dropwise over 6 hours.

  After completion of the dropwise addition, the reaction solution was held at the same temperature for 15 hours to complete the reaction. Further, the obtained polymer solution was kept under a reduced pressure of about 20 Torr to remove xylene. A vinyl polymer (A-3) having a number average molecular weight of 2300, a softening point of 108 ° C. and a hydroxyl value of 107 was obtained.

Reference Example 4 [Preparation Example of Vinyl Polymer (A-4) Combined with Hydroxyl and Carboxylic Acid Ester Groups]
In a reaction vessel similar to Reference Example 1, 100 parts by weight of xylene and 50 parts by weight of normal butanol were charged, and the temperature was raised to 114 ° C. in a nitrogen atmosphere.
Subsequently, at the same temperature, a mixture composed of 20 parts by weight of styrene, 20 parts by weight of methyl methacrylate, 60 parts by weight of 2-hydroxyethyl methacrylate, and 7 parts by weight of TBO was dropped over 6 hours.

  After completion of the dropwise addition, the mixture was held at the same temperature for 15 hours to complete the reaction, and further 100 parts by weight of toluene was added to the obtained polymer solution, followed by vacuum distillation, and By holding under reduced pressure of about 20 Torr and removing the solvent, a vinyl polymer (A-4) having a number average molecular weight of 2000, a softening point of 120 ° C. and a hydroxyl value of 259 was obtained.

Reference Example 5 [Preparation Example of Polyester Resin Combined with Hydroxyl and Carboxylic Acid Ester Groups (A-5)]
Neopentyl glycol 160 parts by weight, ethylene glycol 210 parts by weight, trimethylolpropane 60 parts by weight, terephthalic acid 450 parts by weight, isophthalic acid 300 parts by weight in a reaction vessel equipped with a stirrer, thermometer, rectification column and nitrogen gas inlet Then, 0.5 part by weight of dibutyltin oxide was charged, and the temperature was raised to 240 ° C. over 5 hours while stirring in a nitrogen atmosphere. The dehydration condensation reaction was continued at 240 ° C. to obtain a polyester resin (A-5) having a number average molecular weight of 1900, an acid value of 5 mgKOH / g, a hydroxyl value of 102 mgKOH / g, and a softening point of 115 ° C.

Reference Example 6 [Preparation example of vinyl polymer (B-1) having two or more hydroxyl groups in one molecule]
A reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel and a nitrogen gas introduction tube was charged with 100 parts by weight of xylene and heated to 135 ° C. under a nitrogen atmosphere.
Next, at the same temperature, a mixture composed of 90 parts by weight of cyclohexyl vinyl ether, 10 parts by weight of 2-hydroxyethyl vinyl ether, and 6 parts by weight of TBO was added dropwise over 6 hours.

  After completion of the dropwise addition, the reaction solution was held at the same temperature for 15 hours to complete the reaction. Further, the obtained polymer solution was kept under a reduced pressure of about 20 Torr to remove xylene. A vinyl polymer (B-1) having a number average molecular weight of 2000, a softening point of 102 ° C., and a hydroxyl value of 55 was obtained.

Reference Example 7 [Preparation example of vinyl polymer (C-1) having two or more carboxylic acid ester groups in one molecule]
In a reaction container similar to that in Reference Example 1, 100 parts by weight of xylene was charged and heated to 135 ° C. in a nitrogen atmosphere.
Subsequently, at the same temperature, a mixture composed of 70 parts by weight of styrene, 30 parts by weight of ethyl acrylate, and 4 parts by weight of TBO was dropped over 6 hours.

  After completion of the dropwise addition, the reaction solution was held at the same temperature for 15 hours to complete the reaction. Further, the obtained polymer solution was kept under a reduced pressure of about 20 Torr to remove xylene. A vinyl polymer (C-1) having a number average molecular weight of 2000, a softening point of 101 ° C., and a hydroxyl value of 0 was obtained.

Reference Example 8 [Preparation example of vinyl polymer (C-2) having two or more carboxylic acid ester groups in one molecule]
In a reaction vessel similar to that of Reference Example 1, 100 parts by weight of xylene was charged and heated to 135 ° C. in a nitrogen atmosphere.
Next, at the same temperature, a mixture consisting of 75 parts by weight of methyl methacrylate, 15 parts by weight of normal butyl methacrylate, 10 parts by weight of 2-ethylhexyl acrylate, and 4 parts by weight of TBO was added dropwise over 6 hours.

  After completion of the dropwise addition, the reaction solution was held at the same temperature for 15 hours to complete the reaction. Further, the obtained polymer solution was kept under a reduced pressure of about 20 Torr to remove xylene. A vinyl polymer (C-2) having a number average molecular weight of 2000, a softening point of 106 ° C., and a hydroxyl value of 0 was obtained.

Reference Example 9 [Preparation Example of Epoxy Group-Containing Vinyl Polymer (D-1)]
In a reaction vessel similar to that of Reference Example 1, 100 parts by weight of xylene was charged and heated to 135 ° C. in a nitrogen atmosphere.
Next, at the same temperature, a mixture composed of 25 parts by weight of styrene, 20 parts by weight of methyl methacrylate, 25 parts by weight of butyl methacrylate, 30 parts by weight of glycidyl methacrylate, and 4 parts by weight of TBO was added dropwise over 6 hours.

  After completion of the dropwise addition, the reaction solution was held at the same temperature for 15 hours to complete the reaction. Further, the obtained polymer solution was kept under a reduced pressure of about 20 Torr to remove xylene. A vinyl polymer (D-1) having a number average molecular weight of 2200, a softening point of 110 ° C., and an epoxy equivalent of 535 was obtained.

Reference Example 10 [Preparation example of N-methyl-2-pyrrolidone trifluoromethanesulfonate (X-1)]
A reaction vessel equipped with a stirrer, a dropping funnel and a nitrogen gas introduction tube was charged with 9.91 parts by weight of N-methyl-2-pyrrolidone and 100 parts by weight of toluene. The mixture was cooled to about 5 ° C. with stirring under a nitrogen atmosphere, and 15.0 parts by weight of trifluoromethanesulfonic acid was added dropwise over 1 hour.

  After completion of the dropwise addition, the reaction was continued for another 5 hours. After the reaction, toluene was distilled off under reduced pressure. This was washed with n-heptane, filtered, and dried under reduced pressure to obtain 23.5 parts by weight of white powdery salt (X-1). It was. Yield = 97%.

Reference Example 11 Preparation Example of N, N-dimethylacetamide / trifluoromethanesulfonate (X-2) In a reaction vessel equipped with a stirrer, a dropping funnel and a nitrogen gas introduction tube, 8.7 g of N, N-dimethylacetamide and 100 ml of toluene was charged. The mixture was cooled to about 5 ° C. with stirring under a nitrogen atmosphere, and 15.0 parts by weight of trifluoromethanesulfonic acid was added dropwise over 1 hour.

  After completion of the dropwise addition, the reaction was continued for another 2 hours. After the reaction, toluene was distilled off under reduced pressure to obtain a solid salt (X-2) quantitatively.

Reference Example 12 Preparation example of N, N′-diacetyl-bis (2,2,6,6-tetramethylpiperidin-4-yl) sebacate trifluoromethanesulfonate (X-3) Stirrer, dropping funnel and introduction of nitrogen gas A reaction vessel equipped with a tube was charged with 5.64 g of N, N′-diacetyl-bis (2,2,6,6-tetramethylpiperidin-4-yl) sebacate and 100 mg of toluene. The mixture was cooled to about 5 ° C. with stirring under a nitrogen atmosphere, and 3.0 g of trifluoromethanesulfonic acid was added dropwise over 10 minutes.

  After completion of the dropwise addition, the reaction was continued for another hour. After the reaction, toluene was distilled off under reduced pressure to obtain 8.6 g of oily salt (X-3). The yield was 99%.

Examples 1-10 and Comparative Examples 1-5
(Preparation of thermosetting powder coating composition)
Each of the blends of the raw materials obtained in each of the reference examples in the ratios shown in Table 1, Table 2 and Table 3 is “APV kneader / MP-2015 type” (manufactured by Tsubako Yokohama Sales Co., Ltd. 2). A thermosetting property having an average particle size of 30 to 40 μm by melt-kneading at 90 to 100 ° C. using a shaft extrusion kneader, finely pulverizing, and classifying with a 200 mesh wire mesh. Powder coating compositions (P-1) to (P-8) and (p-1) to (p-6) were prepared.

1) DDA; 1,12-dodecanedioic acid (manufactured by Ube Industries, Ltd.)
2) POWDERMATE 570 FL; surface conditioner (trade name, manufactured by Troy Chemical Corporation)
3) Superbecamine L-164; butyl etherified melamine resin. Nonvolatile content is 97% or more. (Product name, manufactured by Dainippon Ink & Chemicals, Inc.)
“TIPT”; tetraisopropyl titanate “p-TSA”; para-toluenesulfonic acid

Subsequently, using the obtained thermosetting powder coating compositions (P-1) to (P-8) and (p-1) to (p-5), various coating compositions were formed according to the following coating film forming method. After producing the coating film, the coating film performance test was performed about each coating film.
About (p-6), blocking generate | occur | produced immediately after coating preparation, and the coating-film formation by coating was impossible. The results are shown in Tables 4, 5, and 6.

[Coating method]
The film thickness after baking thermosetting powder coating compositions (P-1) to (P-8) and (p-1) to (p-5) on the base material is 60 to 70 μm, respectively. Thus, after electrostatic powder coating is performed on the substrate, baking is performed under the condition of 120 ° C./20 minutes, and a coating film made of a thermosetting powder coating composition (hereinafter referred to as a powder coating film). To be coated was obtained.
In addition, as the base material, a 0.8 mm (thickness) × 70 mm × 150 mm zinc phosphate treated steel plate was used.

Hardness: Pencil hardness (using Mitsubishi Uni, JIS K5600-5-4). The pencil hardness is applied to the paint film so that no scratches remain.

Solvent resistance: The film after rubbing the coating film 10 times with a felt soaked with xylene was visually judged.
A: The coating film is glossy and there is no noticeable damage to the coating film.
○: The coating film has gloss, but is etched with a solvent.
Δ: The gloss of the coating film is inferior and is etched with a solvent.
X: The coating film is dissolved by the solvent and has no gloss.

Acid resistance: A panel on which 0.1 milliliter of 10% sulfuric acid aqueous solution was placed on the surface of the coating was held in a hot air dryer at 70 ° C for 30 minutes, and then the surface of the coating was washed with water and dried. Then, the state of the surface of the coating film was visually judged.

◎ ・ ・ ・ No etching.
○ ・ ・ ・ Slightly etched.
Δ: Slightly high degree of etching.
X: The coating film is dissolved by etching.

Flexibility: The crack of the coating film at a portion bent at 90 ° with the coating surface facing upward at 25 ° C. was determined.
◎ ・ ・ ・ No cracks are observed.
○: Slight cracking is observed.
Δ: Cracks are observed in about half of the bent length.
X: cracks are observed on the entire surface.

Storage stability: The amount of paint sprayed when applied with a spray gun after 2 weeks storage at room temperature.
○: Can be painted well.
Δ: Blocking slightly, and sometimes the discharge of paint from the spray gun is not constant.
X: Blocking occurs and spray coating is impossible.

Claims (8)

A thermosetting powder coating composition containing a film-forming component capable of crosslinking and curing by transesterification reaction between a carboxylic ester group and a hydroxyl group, and a transesterification catalyst, wherein the transesterification catalyst comprises a carboxylic acid amide and a fluorine atom It is composed of an organic sulfonate (X) formed from an organic sulfonic acid having a carboxylic acid amide, and the carboxylic acid amide is a compound represented by the following general formula (I) or two or more in one molecule A thermosetting powder coating composition, which is a compound having an N-alkanoyl-2,2,6,6-tetramethylpiperidin-4-yl group.

[Wherein, R 1, R 2 and R 3 each independently represents a hydrogen atom or a monovalent organic group. Further, R2 and R3 Luke to form a divalent group represented by one general formula bonded to each other (II), or, R1 and R2 are bonded total number of carbon atoms comprising the 2 mutually Either 11 substituted or unsubstituted alkylene groups may be formed .

(In the formula, R 4 represents a hydrogen atom or a methyl group, and Y represents a direct bond, a methylene group, a substituted methylene group, or an oxygen atom. )] The thermosetting powder coating composition according to claim 1, wherein the film-forming component contains a polymer having two or more hydroxyl groups and / or two or more carboxylic acid ester groups in one molecule. The thermosetting powder coating composition according to claim 1, wherein the film forming component is a vinyl polymer. The thermosetting powder coating composition according to any one of claims 1 to 3, wherein the carboxylic acid amide compound is N-methyl-2-pyrrolidone. The thermosetting powder coating composition according to any one of claims 1 to 3, wherein the organic sulfonic acid having a fluorine atom is represented by the general formula (III).

(In the formula, R5 represents a monovalent organic group having a fluorine atom.) The thermosetting powder coating composition according to any one of claims 1 to 3, wherein the organic sulfonate (X) has a structure represented by the general formula (IV).

[Wherein, R 1, R 2 and R 3 each independently represents a hydrogen atom or a monovalent organic group. Further, R2 and R3 Luke to form a divalent group represented by one general formula bonded to each other (II), or, R1 and R2 are bonded total number of carbon atoms comprising the 2 mutually Either 11 substituted or unsubstituted alkylene groups may be formed .

(In the formula, R4 represents a hydrogen atom or a methyl group, and Y represents a direct bond, a methylene group, a substituted methylene group, or an oxygen atom.)
R 5 represents a monovalent organic group having a fluorine atom. ] 6. The thermosetting powder coating composition according to claim 5 , wherein R5 in the general formula (III) is a monovalent organic group represented by the general formula (V).

[Wherein, R 6 represents a hydrogen atom, a fluorine atom, or a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms. ] Hardened | cured material obtained by apply | coating the thermosetting powder coating composition in any one of Claims 1-3 to a base material, and carrying out cross-linking hardening of this coated thermosetting powder coating composition.