JP3505284B2 - Thermosetting powder coating, coating method using the same, and coated product - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting powder coating material. More specifically, the present invention relates to excellent appearance characteristics (smoothness, sharpness, etc.), physical characteristics (shock resistance, resistance to impact). Chipping resistance, scratch resistance, adhesion, etc.), the coating does not become yellowish, and yellowing resistance (in this specification means little change in yellowness over time), weather resistance and UV resistance And a thermosetting powder coating which can develop a coating film after baking having chemical properties (acid resistance, solvent resistance, etc.), has excellent storage stability, and has low-temperature curability. Further, the present invention relates to a coating method using the coating composition and a coated product.

[0002]

[Prior art]

[Research and development trends in the technical field of paints from the perspective of ecology, etc. and expectations for powder type paints] Conventionally, solvent-type paints have been used for painting objects, and in fields where severe quality is required such as for automobiles For use, paints have been developed and used that meet various requirements. In recent years, in the technical field of paints, from the viewpoint of local or global environmental conservation, improvement of occupational safety and health environment, prevention of fire and explosion, resource saving, etc., solvent type paints have been replaced by powder type paints. Has been expected.

As the expectation for higher functionality and diversification of powder type paints increases due to historical or social demands, powder type paints have high coating film performance comparable to solvent type paints. (For example, impact resistance, acid rain resistance, etc.) have been required. However, although the coating film performance required for powder-type paints has become strict, it cannot always be said that powder-type paints that completely satisfy such requirements have been put on the market.

Specific examples of conventional powder coatings include epoxy resin and polyester resin powder coatings containing bisphenol A as a main component. However,
These have not only a problem in weather resistance, but also a problem in resistance to acid rain, which has recently been particularly problematic, and there is a problem in applications that are intended for outdoor use such as car body painting.

JP-A-49-34546 discloses a coating material which is cured by a reaction between an acrylic resin component having a glycidyl group and an aliphatic dibasic acid which is a curing agent component. However, the curing rate of the powder coating was not sufficient, and high temperature and long baking conditions were essential. The coating film formed from the powder coating material was not always sufficient in physical properties such as solvent resistance and adhesion.

In order to solve such a problem, when a curing catalyst is added to a powder coating composition, the smoothness of the coating film is insufficient or the storage stability of the coating composition is deteriorated. The problem of occurs. Even if an attempt was made to perform low temperature curing by increasing the functional group density of the glycidyl group of the acrylic resin component or the carboxyl group of the curing agent component without using a catalyst, the same other problems arose. Many researches and developments have been promoted for the purpose of solving the problems of the above-mentioned known technology.

JP-B-58-2983 discloses a copolymer containing 5 to 20% by weight of a monomer having a glycidyl group,
A coating which is crosslinked and cured from an acid anhydride group is disclosed. However, if the monomer having a glycidyl group is 20
In the case of the copolymer containing less than or equal to wt%, the cross-linking density of the obtained coating film was insufficient, and the coating film physical properties and weather resistance were not always sufficient.

Further, the compound having an acid anhydride group disclosed in JP-B-58-2983 is an aromatic or alicyclic cyclic acid anhydride, and when these acid anhydrides are used. Has a problem that the compatibility between the resin and the acid anhydride compound is low. Since these acid anhydrides generally have high melting points, when used as a curing agent, the physical properties of the coating film formed, such as appearance and impact resistance, were not sufficient.

Japanese Unexamined Patent Publication (Kokai) No. 63-165463 discloses that a specific glycidyl group-functional acrylic resin, an aliphatic dibasic acid (anhydride) and an alkyl titanate compound as main components are melted and cured at a low temperature and have a hardness. , A thermosetting acrylic resin powder coating composition which gives a coating film excellent in impact resistance, bending resistance and the like is disclosed.

That is, a glycidyl group-functional acrylic resin obtained by copolymerizing (A) an alkyl ester of (meth) acrylic acid having 1 to 14 carbon atoms and a glycidyl ester of (meth) acrylic acid as main components. , (B)
Aliphatic dibasic acid (preferably adipic acid, sebacic acid,
Decanedicarboxylic acid, muconic acid, etc.) or a linear acid anhydride thereof, and an alkyl titanate compound represented by the formula (C) Ti (OR) ₄ (R is an alkyl group having 15 to 20 carbon atoms) (eg; Tetrapentadecyl titanate, etc.),
A thermosetting acrylic resin powder coating containing as a main component is disclosed.

However, the present invention does not disclose that the aliphatic dibasic acid and the aliphatic dibasic acid linear anhydride used as the curing agent component are used at the same time, and the aliphatic dibasic acid alone can be obtained. Insufficient cross-link density of the coating film makes it inferior in solvent resistance, scratch resistance, coating appearance, etc. In addition, only aliphatic dibasic acid linear acid anhydride has storage stability and impact resistance. There was a problem with the yellowing of the coating film.

Japanese Unexamined Patent Publication (Kokai) No. 5-112743 discloses that a monomer having at least 20% by weight of a glycidyl group and 35 to 50 are used.
Disclosed is a powder coating containing a resin component containing an acrylic resin synthesized from a system containing wt% styrene monomer and a curing agent component containing an aliphatic or alicyclic dicarboxylic acid or a linear acid anhydride thereof. ing. The coating film obtained from this paint has excellent coating film smoothness. However, regarding the resin component, when the amount of styrene exceeds 30% by weight, the coating film becomes yellowish and the yellowing resistance and weather resistance are poor, which is a problem. Further, regarding the curing agent component, there is no disclosure of using aliphatic dicarboxylic acids and their linear acid anhydrides at the same time, and when only dicarboxylic acids are used, there is a problem with the coating film appearance and solvent resistance. When only the linear acid anhydride of dicarboxylic acid is used, there are problems in storage stability of the coating composition, yellowing of the coating film, impact resistance and the like.

Japanese Unexamined Patent Publication (Kokai) No. 5-132634 discloses, as an acrylic resin component, a copolymer synthesized from a system containing a monomer having a glycidyl group and tertiary butyl acrylate or tertiary butyl methacrylate as a curing agent component. There is disclosed a technique of forming a coating film by using the same one as described in JP-A-5-112743 and in the same curing mode as the conventional technique. However, regarding the acrylic resin component, when tert-butyl acrylate or tert-butyl methacrylate is used as a monomer, these may cause a side reaction with another monomer having a glycidyl group during the polymerization, or during the polymerization. In addition, thermal decomposition may occur during solvent removal during recovery, and a gelled product which is a product of an undesirable side reaction is likely to occur. When a coating film is formed from a powder coating composition containing such a gel-like material, it is not preferable because uneven coating is generated on the surface of the coating film.

US Pat. No. 3,845,016 discloses an acrylic resin component obtained by copolymerizing a reaction system containing a monomer having a glycidyl group, methacrylonitrile, and methyl methacrylate as a curing agent component with a linear acid. A method for forming a coating film using an anhydride is disclosed. However, regarding the acrylic resin component, the copolymer of the acrylic resin component lacks storage stability of the powder coating composition,
The coating film formed from the composition had a problem of lacking gloss and smoothness. Further, regarding the curing agent component, there is no disclosure of using a dicarboxylic acid and a linear acid anhydride of a dicarboxylic acid at the same time, and since only the linear acid anhydride of a dicarboxylic acid is used, the storage stability of the coating composition is improved. However, there was a problem in impact resistance and yellowing of the coating film.

US Pat. No. 3,919,346 and US Pat. No. 3,919,347 are copolymers composed of a system containing a monomer having a glycidyl group and a monomer having a hydroxyl group as an acrylic resin component. Is disclosed as a curing agent component using a dicarboxylic acid anhydride to crosslink and cure. However, even in this invention, there is no disclosure of simultaneously using a dicarboxylic acid and an anhydride of a dicarboxylic acid as a curing agent, and since only an acid anhydride group is used, the storage stability of the coating is poor, Further, there were problems in impact resistance and yellowing of the coating film.

Japanese Unexamined Patent Publication (Kokai) No. 50-51542 discloses a copolymer composed of a system containing, as an acrylic resin component, 5 to 20% by weight of a monomer having a glycidyl group, a dicarboxylic acid and a linear acid anhydride. This is a method of crosslinking and curing using a curing agent, but in the case of a copolymer containing 20% by weight or less of a glycidyl group, the crosslink density of the obtained coating film is insufficient and the physical properties of the coating film are It was inferior in weather resistance.

As shown in the above-mentioned prior art, when only an aliphatic polycarboxylic acid is used as a curing agent for an acrylic resin having a glycidyl group, low temperature curing property, scratch resistance of the obtained coating film, Inferior in acid resistance, solvent resistance, smoothness, and image clarity, when using only aliphatic polycarboxylic acid linear acid linear anhydride, storage stability of the paint, the coating film obtained There are problems such as inferior impact resistance and yellowing,
Further, the coating film obtained by curing only the aliphatic polycarboxylic acid linear acid anhydride is apt to cause cracks and pinholes, and particularly when used as a transparent coating for automobile top coating, the appearance (visibility) is deteriorated. There was a problem with.

[0018]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention is a coating film for topcoating and intermediate coating, particularly for automobile bodies and automobile parts (aluminum wheels, wipers, pillars, door handles, etc.). Excellent appearance characteristics (smoothness, sharpness, etc.), physical characteristics (impact resistance, chipping resistance, scratch resistance, adhesion, etc.), weather resistance, UV resistance, chemical characteristics (required as properties) For the purpose of providing a thermosetting powder coating composition capable of developing a coating film after baking having acid resistance, solvent resistance, etc.) and yellowing resistance, having excellent storage stability and having low temperature curability. It was made. Further, the present invention has been made for the purpose of providing a thermosetting powder coating composition having the above-mentioned excellent performance even when coated and baked on an aqueous undercoat coating.

[0019]

In order to solve the above problems, the inventor of the present invention has earnestly studied and reached the present invention. That is, in the present invention, at least one glycidyl group and at least one unsaturated double bond are intramolecularly contained as (a1) in 100 molecules by weight of the monomers (a1), (a2) and (a3). 60 parts by weight in excess of 20 parts of the ethylenically unsaturated monomer having 1 to 30 parts by weight of styrene as (a2), and
As (a3), a copolymer obtained by polymerizing in a reaction system containing 10 to 79 parts by weight of an ethylenically unsaturated monomer having neither a carboxyl group nor a tertiary butyl ester group in the molecule. It is intended to provide a thermosetting powder coating material containing (A), an aliphatic polycarboxylic acid (B), and an aliphatic polycarboxylic acid linear acid anhydride (C).

The present invention further comprises the above-mentioned components (A), (B) and (C), a salt (D) of a tertiary amine compound and an organic acid and / or a melting point of about 20 ° C to about 150 ° C. It is intended to provide a thermosetting powder coating material further containing a primary amine compound (E).

The component (A) of the present invention is a thermosetting powder coating composition having a glass transition temperature of about 20 to about 100 ° C. and a number average molecular weight of about 1,000 to about 30,000 as determined by Fox's formula. To provide.

In the present invention, the components (A), (B) and (C) are contained, and 1 equivalent of the glycidyl group in the molecule of the copolymer (A) is added to the aliphatic polycarboxylic acid (B). The carboxyl group is 0.1 to 1.2 equivalents, the acid anhydride group in the aliphatic polycarboxylic acid linear anhydride (C) is 0.1 to 1.2 equivalents, and the carboxyl group in (B) is And (C) to provide a thermosetting powder coating material in which the total of acid anhydride groups is 0.5 to 2 equivalents.

In the present invention, the carboxyl group in the aliphatic polyvalent carboxylic acid (B) is about 0.3 to about 0.8 equivalent to 1 equivalent of the glycidyl group in the copolymer (A), and Group polycarboxylic acid, the acid anhydride group in the linear acid anhydride (C) is about 0.2 to about 0.6 equivalent, and the carboxyl group in the aliphatic polycarboxylic acid (B) and the aliphatic group. It is a thermosetting powder coating material in which the total number of acid anhydride groups in the polycarboxylic acid linear acid anhydride (C) is about 0.7 to about 1.2 equivalents.

In the present invention, as the following component (a1), monomers 20 to 60 having a glycidyl group and an unsaturated double bond are used.
% By weight, 1 to 30% by weight of (a2) and 1 to 30% by weight of styrene, and other monomers which are radically copolymerizable with (a1) and (a2) and have no carboxyl group in the molecule. ~ 79 wt%, glass transition temperature 2
Copolymer (A) having a number average molecular weight of 2000 to 10000 at 0 to 100 ° C., an aliphatic dibasic acid (B), an aliphatic polycarboxylic acid linear acid anhydride (C), and an organic amine salt ( D), the carboxyl group in the aliphatic dibasic acid (B) is 0.1 to 1.2 per 1 glycidyl group in the copolymer (A), linear aliphatic polycarboxylic acid The acid anhydride group in the acid anhydride (C) is 0.1 to 1.2 per 1 glycidyl group in the copolymer (A), and the carboxyl group in (B) and the aliphatic polyvalent group. The total number of acid anhydride groups in the carboxylic acid linear acid anhydride (C) is 0.5 to 1 glycidyl group.
2, the organic amine salt (D) is the above composition (A),
0.03 to 100 parts by weight of (B) and (C) in total
It is a thermosetting powder coating material formed by using parts by weight.

In the present invention, a monomer 2 having a glycidyl group and an unsaturated double bond as (a1) is added to 100 parts by weight of the total weight of the monomers (a1), (a2) and (a3).
0 to 60 parts by weight, (a2) 1 to 30 parts by weight of styrene, and (a3) 10 to 79 parts by weight of a monomer having no carboxyl group and no glycidyl group in the molecule. The glass transition temperature obtained by polymerization is about 20 to about 100 ° C., the number average molecular weight is about 2,000 to about 10,000.
Is a copolymer (A), an aliphatic polycarboxylic acid (B),
In a thermosetting powder coating composition containing an aliphatic polycarboxylic acid linear acid anhydride (C) and a solid amine compound (E), with respect to 1 equivalent of glycidyl groups in the molecule of the copolymer (A). The carboxyl group in the aliphatic polycarboxylic acid (B) is 0.1 to 1.2 equivalents, and the acid anhydride group in the aliphatic polycarboxylic acid linear acid anhydride (C) is 0.1. To 1.2 equivalents, the total of the carboxyl group in (B) and the acid anhydride group in (C) is 0.5 to 2 equivalents, and the solid amine compound (E) has the above composition. Items (A), (B) and (C)
It is 0.01 to 3 parts by weight with respect to the total weight of 100 parts by weight.

The present invention is based on 100 parts by weight of the copolymer (A), the aliphatic polycarboxylic acid (B) and the aliphatic polycarboxylic acid linear acid anhydride (C), and the tertiary amine. It is a thermosetting powder coating material in which the salt (D) of the compound and the organic acid is about 0.01 to about 3 parts by weight.

The present invention has a melting point of about 20 with respect to a total of 100 parts by weight of the copolymer (A), the aliphatic polycarboxylic acid (B) and the aliphatic polycarboxylic acid linear acid anhydride (C). ℃ ~
It is a thermosetting powder coating composition containing about 0.01 to about 3 parts by weight of the tertiary amine compound (E) at about 150 ° C.

In the present invention, the salt (D) of the tertiary amine compound and an organic acid is 1,8-diazabicyclo [5.4.0].
-7-A thermosetting powder coating which is a salt of undecene and an organic acid. In the present invention, the tertiary amine compound (E) having a melting point of about 20 ° C. to about 150 ° C. has an N-methyl-N, N-dialkyl (alkyl group having 2 to 30 carbon atoms) amine structure.
It is a thermosetting powder coating material which is at least one kind of compound selected from the group of primary amine compounds.

The copolymer (A) of the present invention is a monomer (a).
1), (a2), (a3) in total 100 parts by weight,
(A1): 20 to 60 parts by weight (a2): 10 to 30 parts by weight and (a3): 10 to 70 parts by weight A thermosetting powder coating obtained by polymerization in a reaction system. .

The copolymer (A) of the present invention is a monomer (a).
1), (a2), (a3) in total 100 parts by weight,
(A1): 25 to 50 parts by weight (a2): 10 to 20 parts by weight and (a3): a thermosetting powder coating obtained by polymerization in a reaction system containing 25 to 65 parts by weight. .

The present invention is a thermosetting powder coating material in which the number average molecular weight of the copolymer (A) is about 2,000 to about 10,000.

It is an object of the present invention to provide a thermosetting powder coating material in which the aliphatic polycarboxylic acid linear acid anhydride (C) is a dehydration condensation product of the aliphatic polycarboxylic acid (B). .

The aliphatic polycarboxylic acid (B) of the present invention
To provide a thermosetting powder coating which is dodecane diacid.

The present invention is to provide a thermosetting powder coating material in which the aliphatic polycarboxylic acid linear acid anhydride (C) is a dehydration condensation product of dodecane diacid.

The present invention relates to the aliphatic polycarboxylic acid (B)
To provide a thermosetting powder coating which is dodecane diacid.

The present invention provides a method for coating an automobile body or automobile parts with the thermosetting powder coating composition according to the present invention.

The present invention electrostatically coats a thermosetting powder coating which is the top coating of Claim 1 or 2 on a base coating of a pigmented or metallic aqueous coating, and simultaneously bake the base coating and the top coating. It is to provide a coating method characterized by the above. The coating method of the present invention is a method of coating an automobile body or an automobile part with the thermosetting powder coating material of the present invention for top coating or intermediate coating.

The present invention is a method of using the coating material according to the present invention for forming a coating film, and a coating film obtained thereby.

Further, the present invention is an automobile or an automobile part coated with the coating material according to the present invention.

The present invention is a method for producing a thermosetting powder coating material, which comprises melting and kneading a raw material containing the coating material component according to the present invention at a temperature of about 40 to about 130 ° C., followed by cooling and pulverizing. Another object of the present invention is to provide a coating method characterized in that the pulverized thermosetting powder coating material is attached to an object to be coated and baked at about 100 to about 180 ° C.

In the present invention, the thermosetting powder coating composition according to the present invention is applied to an object by an electrostatic coating method, and the amount is about 100 to about 180.
It is to provide a coating method characterized by baking at ℃.

The present invention uses the above (A), (B), (C), or the combination of these with (D) and / or (E), and the component (A) having a specific styrene content. In this respect, it is particularly characteristic, and by controlling the composition and the composition ratio of these, it is possible to exhibit higher effects.

The coating film formed by using the thermosetting powder coating material of the present invention is excellent in low-temperature curing property, mechanical properties, appearance and storage stability of the coating composition.

[0044]

DETAILED DESCRIPTION OF THE INVENTION

[Structure of the present invention] The basic structure of the present invention is as follows (A).
To (C), and optionally (D) and / or (E), are thermosetting powder coating compositions.

(1) Copolymer (A) In the present specification, the copolymer may be a random copolymer, an alternating copolymer, a block copolymer, a graft copolymer or the like, and the polymer is , Linear, macrocyclic, branched, star-shaped,
It may be a three-dimensional mesh or the like.

In the present invention, the monomer (a1) having a glycidyl group and an unsaturated double bond in the copolymer (A) is not particularly limited as long as it is a compound having both a glycidyl group and an unsaturated double bond. Not done.

Specific examples of the monomer (a1) include glycidyl acrylate, glycidyl methacrylate, β-methylglycidyl acrylate, β-methylglycidyl methacrylate, N-glycidyl acrylic acid amide, allyl glycidyl ether and glycidyl vinyl sulfonate. Among these, glycidyl acrylate,
Glycidyl methacrylate is preferable, and these can be used alone or in combination of two or more kinds.

The amount of the monomer (a1) used in the copolymer (A) is preferably more than 20% by weight and about 60% by weight, more preferably 25 to 50% by weight. Monomer (a1)
When the amount used is more than 20% by weight, the resulting coating film has a high cross-linking density and good coating characteristics such as impact resistance, scratch resistance and solvent resistance are preferable. When the amount of the monomer (a1) used is about 60% by weight or less, the appearance of the coating film such as smoothness and sharpness is good, which is preferable.

The styrene component (a) copolymerized in (A)
2) is preferably in the range of 1 to 30% by weight, 10 to 30
% Is more preferable, and 10 to 20% is even more preferable.

The styrene component contributes to the properties such as gloss and smoothness of the coating film and the storage stability of the coating composition. Regarding the amount of the styrene component (a2) used, if it is 1% by weight or less,
The effect due to styrene is reduced, and if it is 30% by weight or more, the coating film tends to be yellowish and the yellowing resistance and weather resistance tend to be lowered.

Used in polymerizing the copolymer (A),
As the ethylenically unsaturated monomer (a3),
Unlike the monomer (a1) and styrene (a2), a compound having neither a carboxyl group nor a tertiary butyl ester group in the molecule and having a radical-polymerizable unsaturated group can be used. It is possible, and you may use together 1 type or more. Specific examples of the monomer (a3) include carboxylic acid esters, unsaturated hydrocarbons, nitriles, amides and the like. Among these, carboxylic acid esters are preferred, and primary or primary An ester of a secondary alcohol and acrylic acid or methacrylic acid is more preferable.

Specific examples of esters of primary or secondary alcohols with acrylic acid or methacrylic acid include:
Methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, stearyl acrylate, cyclohexyl acrylate, benzyl acrylate, phenyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, 1,4 butanediol monoacrylate, acrylic acid derivatives such as dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate , Stearyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, 1,4 butanediol monomethacrylate, methacrylic acid derivatives such as dimethylaminoethyl methacrylate, vinyl acetate, propionic acid Vinyl esters such as vinyl, dicarboxylic acid esters such as maleic acid and itaconic acid, unsaturated hydrocarbons such as α-methylstyrene, vinyltoluene, t-butylstyrene, vinylanisole, vinylnaphthalene, divinylbenzene and chlorostyrene. , Nitriles such as acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinylamide , N-methylol acrylamide, N-methylol methacrylamide, diacetone acrylamide, diacetone methacrylamide and other amides, vinyl chloride, vinylidene chloride, vinyl fluoride, monochlorotrifluoroethylene, tetrafluoroethylene, halogenated ethylene such as chloroprene Unsaturated monomers, ethylene, propylene, isoprene, butadiene, α-olefins or dienes having 4 to 20 carbon atoms, alkyl vinyl ethers such as lauryl vinyl ether, nitrogen-containing vinyls such as vinylpyrrolidone and 4-vinylpyrrolidone, Examples thereof include ethylenically unsaturated monomers including nitriles such as acrylonitrile and methacrylonitrile, and these can be used alone or in combination of two or more.

The amount of the monomer (a3) used is preferably 10 to 79% by weight, more preferably 10 to 70% by weight of the copolymer (A).
% Is more preferable, and 30 to 65% by weight is even more preferable.

When a compound having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid or itaconic acid is used as the monomer (a3) in the copolymerization of (A),
It is not preferable because it may cause gelation during polymerization, decomposition of the copolymer (A) due to heating during solvent removal or preparation of a coating composition, and formation of spots on the coating film after coating film formation. .

In the copolymerization of (A), the monomer (a
When t-butyl (meth) acrylate is used as 3), the same problem as described above may occur, which is not preferable.

The calculated glass transition point (Tg) of the copolymer (A) obtained by the Fox equation is about 20 to about 100 ° C., preferably about 30 to about 90 ° C., more preferably 50. ~ 80 ° C. If the Tg is 20 ° C. or lower, the storage stability of the coating composition tends to deteriorate.

[Calculated value of glass transition point-evaluation of glass transition point (Tg) of heteropolymer] The glass transition point (Tg) of a polymer having a specific monomer composition is Fox (Fo).
It can be calculated by the formula of x). Here, the Fox equation is for calculating the Tg of the copolymer based on the Tg of the homopolymer of the individual monomers forming the copolymer, See the Bulletin of the American Physical Society, Series 2 (Bulletin of
the American Physical So
cietie, Series 2) Vol. 1, No. 3, p. 123 (1956).

The Tg of various ethylenically unsaturated monomers, which is the basis for evaluating the Tg of a copolymer according to Fox's equation, can be found, for example, in New Polymer Bunko, Volume 7, Introduction to Synthetic Resins for Paints (Kitaoka Kyozo, Polymer Society, Kyoto, 1
974) The numerical values described in Table 10-2 (main raw material monomers of acrylic resin for paints) on pages 168 to 169 can be adopted.

All the descriptions are made part of the disclosure of the present application specification by clearly indicating the cited document and the citation range, and from the matters or the disclosures described in the present application specification by referring to the explicitly cited range. Only the matters or disclosures that can be derived directly and unambiguously by those skilled in the art.

The method for synthesizing the copolymer (A) is not particularly limited as long as it has substantially the desired properties. The copolymer (A) can be synthesized by a known and publicly known ordinary method, and can be prepared by a radical polymerization method including a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, and a bulk polymerization method. Especially, the solution polymerization method is preferably used.

As a method for adjusting the molecular weight of the copolymer (A), mercaptans such as dodecyl mercaptan, disulfides such as dibenzoyl sulfide,
Chain transfer agents for C1-C18 alkyl esters of thioglycolic acid such as 2-ethylhexyl thioglycolate, halogenated hydrocarbons such as urea tetrabromide, chain transfer effects of isopropyl alcohol, isopropylbenzene, toluene, etc. It is possible to use means such as polymerization in the presence of a large organic solvent.

The number average molecular weight of the above copolymer (A) is preferably from about 1,000 to about 30,000, and from about 2,000.
More preferably about 20,000, most preferably about 2.5
It is from 00 to about 6,000.

When the number average molecular weight is about 1,000 or more, the storage stability of the coating composition is good, which is preferable. The number average molecular weight of the copolymer (A) was evaluated by gel permeation chromatography (GPC) using polystyrene as a standard. (2) Aliphatic polycarboxylic acid (B) In the present invention, the aliphatic polycarboxylic acid (B) is particularly preferably an aliphatic compound having at least two carboxyl groups in the molecule. Without limitation, one kind or two or more kinds can be used.

Specific examples of the aliphatic polycarboxylic acid (B) include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, citric acid, maleic acid, citraconic acid and itaconic acid. , Glutaconic acid, undecane 2 acid, dodecane 2 acid, pentadecane 2 acid, tridecane 2 acid, tetradecane 2 acid, hexadecane 2 acid, octadecane 2 acid, eicosane 2 acid, docosane 2 acid, tetratocoic acid 2 acid, and the like. Among them, dodecanedioic acid is preferable, and these can be used alone or in combination of two or more kinds.

In the present specification, the concept of "aliphatic" includes an alicyclic group having a low degree of aromaticity, such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid. Can also be used as the component (B).
Aromatic polycarboxylic acids are not preferable in terms of coating properties such as smoothness, impact resistance and weather resistance.

The amount of the aliphatic polycarboxylic acid (B) used is
With respect to 1 equivalent of the glycidyl group in the copolymer (A),
The carboxyl group in (B) is preferably about 0.1 to about 1.2 equivalents, more preferably about 0.3 to about 0.8 equivalents.
When the amount of the aliphatic polycarboxylic acid (B) used is within this range, the resulting coating film has good properties such as solvent resistance, impact resistance, and storage stability of the paint.

Here, the amount of (B) used is generally
The ratio of the total equivalents of the carboxyl groups of (B) and the acid anhydride groups of (C) to the equivalents of glycidyl groups of (A) corresponds to about 0.5: about 1 to about 1: about 0.5. Is the amount.

(3) Aliphatic polycarboxylic acid linear acid anhydride (C) At least one kind of aliphatic polycarboxylic acid linear acid selected from the group consisting of aliphatic polycarboxylic acid linear acid anhydrides Acid anhydride (C).

In the present invention, the aliphatic polycarboxylic acid linear acid anhydride (C) is substantially a linear dimer or higher oligomer or poly with or without a carboxyl group in the molecule. Which is an aliphatic acid anhydride (anhydrido), and is not particularly limited as long as it is a compound having at least two carboxyl groups and / or acid anhydride (anhydride) groups substantially existing in the molecule, 1 Type or 2
More than one type can be used.

(C) is generally a polycarboxylic acid linear acid anhydride and / or an aliphatic dicarboxylic acid linear acid anhydride represented by the following general formula.

[0071] _{HO- [OC (CH2) m COO} ] n -H (m ≧ 1, n ≧ 2, preferably n is from about 40 or less, more preferably 30 or less, m is about 25 or less, preferably 20 The following natural numbers) Here, specific examples of the polycarboxylic acid linear acid anhydride include:
For example, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane diacid, dodecane diacid,
A dehydrated linear condensate of eicosane diacid and octadecane diacid is preferable, and a dehydrated linear condensate of dodecane diacid is more preferable.

In the specification of the present application, the concept of "linear" includes not only linear, but also linear dimeric or higher oligo- or poly-aliphatic acid anhydrides (anhydrides) as macrocycles. It also includes the case of forming. Further, a copolymerized linear condensate of two or more kinds of aliphatic polycarboxylic acids can also be used.

When a cyclic acid anhydride of polyvalent carboxylic acid such as succinic anhydride or phthalic anhydride is reacted with the copolymer (A), the acid anhydride is converted into the copolymer (A) molecule. The use of this compound is not preferable because it has a high probability of reacting only with the epoxy ring of the specific glycidyl group, and thus has a small effect of bridging a plurality of copolymer (A) molecules.

As used herein, “anhydrido”,
The concept of "anhydrido group", "anhydrido bond" and "polyanhydride" is described in the section "Polyanhydride" on pages 996 to 998, MARUZEN macromolecule dictionary (Maruzen, 1994). It also includes the concept of each word.

Polyanhydride has been actively researched and developed for biodegradable bio (medical) polymer materials and application of the materials to drug delivery systems. 1
In the early 980s, MIT researchers actively studied and attracted attention.

The linear or dimeric oligo- or poly-aliphatic acid anhydride (anhydride) can be synthesized by a method such as melt polycondensation, solution polycondensation or interfacial polycondensation.

Aliphatic polycarboxylic acid linear acid anhydride (C)
Is preferably prepared to have a melting point in the range of about 40 to about 150 ° C. Generally, when the melting point of the aliphatic polycarboxylic acid linear acid anhydride (C) is about 40 ° C. or lower, the storage stability of the coating composition tends to decrease. Generally, the melting point of the aliphatic polycarboxylic acid linear acid anhydride (C) is about 15
Above 0 ° C, the heating fluidity of the coating tends to decrease,
Appearance characteristics such as smoothness of the resulting coating film tend to deteriorate.

Aliphatic polycarboxylic acid linear acid anhydride (C)
The amount of the acid anhydride group is about 0.1 to about 1.2 equivalents, preferably about 0.2 to about 0.6 equivalents, relative to 1 equivalent of the glycidyl group in the copolymer (A). preferable.

Aliphatic polycarboxylic acid linear acid anhydride (C)
With respect to the amount used, the obtained coating film has a small appearance of popping (popping: a phenomenon that bubbles remain in the coating film) and pinholes, and the appearance of the coating film is good. Has excellent properties such as solvent resistance, impact resistance, and weather resistance.

The total amount of the carboxyl groups in the aliphatic dicarboxylic acid (B) and the acid anhydride groups in the aliphatic polycarboxylic acid linear acid anhydride (C) used is the same as that in the copolymer (A). It is preferably about 0.5 to about 2 equivalents, and more preferably about 0.7 to about 1.2 equivalents, relative to 1 equivalent of the glycidyl group.

The characteristics of the coating film formed from the powder coating composition are as follows: Aliphatic polycarboxylic acid linear acid anhydride (C)
When used together with the aliphatic dicarboxylic acid (B), excellent mechanical properties and appearance characteristics are exhibited due to a synergistic effect, as compared with the case where each is used alone.

Compared with the case where the aliphatic polycarboxylic acid (B) is used alone, when the aliphatic polycarboxylic acid linear acid anhydride (C) and the aliphatic polycarboxylic acid (B) are used in combination Is superior in low-temperature curing property, scratch resistance, chipping resistance, solvent resistance, acid resistance, smoothness, and sharpness to the coating film formed from the powder coating composition. .

Aliphatic polycarboxylic acid linear acid anhydride (C)
Compared with the case of using the same alone, when the aliphatic polycarboxylic acid linear acid anhydride (C) and the aliphatic polycarboxylic acid (B) are used in combination, the storage stability of the coating composition is more excellent. As for the characteristics of the coating film formed from the powder coating composition, excellent yellowing resistance, impact resistance are obtained, and there is no cracking, pinholes, etc. The thing of is obtained.

The aliphatic polycarboxylic acid (B) is mainly used for storage stability of the coating composition, impact resistance of the coating film, yellowing,
Contributes to the prevention of armpits and pinholes, and the aliphatic polycarboxylic acid linear acid anhydride (C) is mainly used for low-temperature curability,
Solvent resistance, scratch resistance, acid resistance, chipping resistance,
It is considered to have the effect of contributing to the improvement of smoothness.

The aliphatic polycarboxylic acid linear acid anhydride (C) is a linear acid anhydride obtained by dehydration condensation from the same compound as the aliphatic polycarboxylic acid (B) used in the coating composition. Is more preferable, and the aliphatic polycarboxylic acid (B) is a dodecane diacid, and the aliphatic polycarboxylic acid linear acid anhydride (C) is a linear acid anhydride of dodecane diacid. More preferably used.

(4) Salt (D) of tertiary amine compound and organic acid The salt (D) of tertiary amine compound and organic acid is used in combination with (A), (B) and (C). By doing so, it is possible to obtain a paint having a good coating film physical property at a lower temperature and in a shorter time, as compared with the case where (D) is not used, without impairing the storage stability of the paint.

As (D), at least one salt of a known tertiary amine compound having an action of promoting curing and a salt of an organic acid, which is generally used in the technical field of paints, can be used. . Examples of the above compound include DBU (1,8-diazabicyclo [5.4.
0] -7-undecene) octylate, formate, carbonate, adipate, orthophthalate, phthalate, phenol salt, octylate, oleate, P-toluenesulfonate, phenol novolac Examples thereof include, but are not limited to, a resin salt and a salt of DBU and an organic acid such as 2-ethylhexanoate (all manufactured by San-Apro Co., Ltd.).

The amount of (D) used is 100 parts by weight based on 100 parts by weight of the copolymer (A), the aliphatic polycarboxylic acid (B), and the aliphatic polycarboxylic acid linear acid anhydride (C). It is preferably 3 parts by weight or less, more preferably about 0.01 to about 3 parts by weight. When the amount of (D) used is 3 parts by weight or less, the storage stability of the coating composition is good, the curing reaction is at an appropriate rate, and the smoothness of the coating film and the storage stability of the coating can be maintained.

(5) Tertiary amine compound (E) having a melting point of about 20 ° C. to about 150 ° C. Tertiary amine compound (E) having a melting point of about 20 ° C. to about 150 ° C.
When used in combination with (A), (B), and (C), the paint baking conditions are lower than those in the case where (E) is not used, without impairing the storage stability of the paint. It is possible to obtain a product having good coating film properties in a short time.

As (E), among known publicly known tertiary amine compounds having an action of promoting curing, which are generally used in the technical field of paints, the melting point is about 20 ° C.
It is possible to use at least one material having a temperature of from about 150 ° C. Examples of the above-mentioned compound include tribenzylamine, (KOEI CHEMICAL COMPANY
LIMITED), Wandamine 3TD-TA, Wandamine 88-TA, Wandamine 3F-TA (all manufactured by Shin Nippon Rika Co., Ltd.), N-methyl-N, N-dialkyl (alkyl group has 2 carbon atoms) To about 30) compounds having the structure of amines, such as ARMEE
Examples thereof include compounds such as N M2HT (manufactured by Lion Akzo Co., Ltd.), and among them, ARMEENM2HT is preferable, but not limited thereto.

The amount of (E) used is 100 parts by weight based on 100 parts by weight of the copolymer (A), the aliphatic polycarboxylic acid (B), and the aliphatic polycarboxylic acid linear acid anhydride (C). Is preferably about 3 parts by weight or less, more preferably about 0.01 to about 3 parts by weight. When the amount of (E) used is 3 parts by weight or less, the storage stability of the coating composition is good, the curing reaction has an appropriate rate, and the smoothness of the coating film and the storage stability of the coating are maintained. (E) is characteristic in that the storage stability of the coating is not impaired even under conditions of high humidity such as 80% or more relative humidity.

Other specific examples of the curing catalyst include quaternary ammonium salt, phosphonium salt, phosphine, imidazole, and melamine compounds. These compounds have an appearance such as coloring and smoothness after forming a coating film, It is not preferable because the storage stability of the paint is extremely poor.

[Additives] In the method of the present invention, various additives which are usually added to paints are added. The thermosetting powder coating composition of the present invention may be a synthetic resin composition containing an epoxy resin, a polyester resin, a polyamide, etc., a natural resin containing a fibrin or a fibrin derivative, or a semi-resin according to the purpose. A synthetic resin composition may be blended to improve the appearance or physical properties of the coating film.

In the thermosetting powder coating composition of the present invention, a pigment, a flow control agent, a thixotropic agent (thixotropic agent), a charge control agent, a surface control agent, a gloss imparting agent, an antiblocking agent are appropriately added depending on the purpose. Additives such as plasticizers, ultraviolet absorbers, anti-armpitting agents, and antioxidants can also be added.

Specific examples of the antiblocking agent suitable for addition to the thermosetting powder coating composition of the present invention include aliphatic amides such as acetamide, propionic amide, stearic amide, and serotic acid amide, Bis fatty acid amides such as diacetamide, bisoleic acid amide, bislauric acid amide, methylenebisstearamide, ethylene bisstearamide, myricyl zerotate, butylene glycol dimontanate, tri-1,2-
Higher fatty acid esters such as glycerin hydroxystearate, molecular weight of about 1,000 to about 10,000
Examples thereof include polyethylene, atactic polypropylene and partially oxidized polyolefins thereof, but are not limited thereto.

The antiblocking agent is usually added in an amount of about 10 parts by weight or less based on 100 parts by weight of the thermosetting powder coating composition of the present invention.

Specific examples of the surface conditioner suitable for addition to the thermosetting powder coating composition of the present invention include (meth) acrylic acid ester type monomers or styrene type monomers alone or in combination. Polymerization oligomer, metal salt of perfluorocarboxylic acid or perfluorosulfonic acid, ester of polyethylene glycol or polypropylene glycol and perfluorocarboxylic acid, and the like,
It is not limited to these.

The surface modifier is usually added in an amount of about 5 parts by weight or less based on 100 parts by weight of the thermosetting powder coating composition of the present invention.

Specific examples of pigments suitable for adding to the thermosetting powder coating composition of the present invention for imparting an appropriate color tone include titanium oxide, iron oxide, chrome oxide, carbon black and the like. Examples thereof include inorganic pigments and organic pigments such as phthalocyanine blue, phthalocyanine green, and cincacia red, but are not limited thereto.

Specific examples of the plasticizer suitable for addition to the thermosetting powder coating composition of the present invention include adipic acid ester, phosphoric acid ester, phthalic acid ester, sebacic acid ester, adipic acid and azelaic acid. Examples thereof include, but are not limited to, polyesters and epoxidized plasticizers.

When the thermosetting powder coating composition of the present invention is used as a clear coat, a pigment is used in an amount within the range in which the complete hiding property is not expressed and the coloring property is expressed. It can also be blended.

[Kneading of powder coating composition]
(A), (B) and (C) or (A), (B),
The temperature of the material to be kneaded when mechanically kneading the composition containing (C) and (D) and / or (E) is not particularly limited as long as a substantially uniform powder coating composition can be prepared.

As the melt-kneading device, a heating roll machine, a heating kneader machine, an extruder (extruder) or the like is usually used.

Specific examples of the method of blending the thermosetting powder coating composition of the present invention include roll machines, kneader machines, mixers (Banbury type, transfer type, etc.), calender equipment, extruders (extruders), etc. The kneaders and kneaders are appropriately combined, and the conditions of each step (temperature, melting or non-melting, rotation speed, vacuum atmosphere, inert gas atmosphere, etc.) are appropriately set and sufficiently mixed. Then, after that, a method of obtaining a powder coating composition in a uniform fine powder state by a pulverizer can be adopted, but the method is not limited thereto.

As an example of an embodiment of a compounding and kneading step in which additives and the like are added to the powder coating composition of the present invention, the thermosetting powder coating composition of the present invention may optionally contain an antiblocking agent and a surface conditioning agent. Agent, plasticizer, charge control agent, pigment, filler,
Additives such as a filler are added, and the mixture is melt-kneaded sufficiently in the range of about 40 to about 130 ° C., cooled, and then uniformly pulverized to have an appropriate particle size (usually about 100 mesh or less).

[Coating Method and Baking Method] "The powder coating material obtained by pulverization is adhered to an object to be coated, heated and heat-cured to form a coating film. The thermosetting powder coating composition according to the present invention Specific examples of the method for coating a product include an electrostatic coating method, a fluid immersion method, etc. When the thermosetting powder coating composition of the present invention is used as an overcoating material, as an undercoating material thereof, In the case of using not only the conventional solvent-based paint but also the water-based paint, the coating film after baking has excellent properties as in the case of using the solvent-based paint.

That is, after coating an aqueous undercoat paint and drying for a predetermined time, the thermosetting powder coating composition of the present invention is applied onto the undercoat paint by the above-mentioned method, and heated to heat-cure. Form a coating film.

The baking of the thermosetting powder coating composition of the present invention is usually performed at a temperature of preferably about 100 to about 180 ° C, more preferably 130 to 160 ° C, usually about 10 ° C.
The cross-linking reaction of the copolymer (A) with the curing agent (B) and (C) can be carried out by carrying out the treatment for about 60 minutes. After baking and cooling to room temperature, a coating film having excellent properties can be obtained.

[Baking coating film forming mechanism of powder coating composition] The thermosetting powder coating composition according to the present invention is uniformly applied on a substrate (base, base material, coating material) and then cured by heating. The reaction (crosslinking reaction) proceeds. This curing reaction
It is thought to proceed as follows. That is, the glycidyl group in the copolymer (A) and the carboxyl group in the aliphatic polycarboxylic acid (B) react with each other, and the secondary hydroxyl group generated from the reaction reacts with the cleaved aliphatic polycarboxylic acid line. It is considered that the acid anhydride (C) is added to cause a secondary reaction.

When a salt (D) of a tertiary amine compound and an organic acid and a tertiary amine compound (E) having a melting point of about 20 ° C. to about 150 ° C. coexist, in the copolymer (A). The glycidyl group and the carboxyl group in the aliphatic polycarboxylic acid (B) react with each other by the catalytic action of (D) and (E), and the secondary hydroxyl group generated from the reaction becomes (D) and (E). Aliphatic polycarboxylic acid linear acid anhydride (C) cleaved by
Is considered to be added to cause a secondary reaction.

In addition to the above reaction, the aliphatic polycarboxylic acid linear acid anhydride (C) is reacted with the terminal carboxylic acid, glycidyl group and acid anhydride group in the presence of (D) and (E). And various glycidyl groups, and various curing reactions such as a reaction of a carboxyl group and a glycidyl group generated from a reaction between an acid anhydride group and a secondary hydroxyl group.

Therefore, a coating film having a higher crosslink density can be obtained as compared with the conventional curing system using only a glycidyl group and a carboxyl group or a glycidyl group and an acid anhydride group, and excellent mechanical properties can be obtained depending on various curing forms. A coating film having various properties such as is obtained.

[Concept of the word "derivative"] The concept of the word "derivative" used in the claims and specification of the present application is such that a hydrogen atom of a specific compound is replaced by another atom or atomic group R. The included items are included.

Here, R is a monovalent hydrocarbon group containing at least one carbon atom, and more specifically, it is an aliphatic group, an alicyclic group having a substantially low aromaticity, or a combination thereof. It may be a group, or a residue in which these are bonded with a hydroxyl group, a carboxyl group, an amino group, nitrogen, sulfur silicon, phosphorus, etc., and among these, particularly those having an aliphatic structure in a narrow sense are preferable.

R is substituted with, for example, a hydroxyl group, an alkyl group, a cycloalkyl group, an allyl group, an alkoxyl group, a cycloalkoxyl group, an allyloxyl group, or a halogen (F, Cl, Br, etc.) group. It may be a group. By properly selecting these substituents, various properties of the coating film formed by the powder coating composition according to the present invention can be controlled.

The evaluation of the coating material of the present invention will be described below. The specific measuring method will be described in the section of Examples.

[Concept of "Chipping Resistance"] "Chipping" used in the claims and specification of the present application.
The concept of the word includes the phenomenon of impact damage when a load is applied to pinpoints in a short time, and in the technical field of automotive paints in particular, when the vehicle body coating film collides with flying pebbles. It also includes the phenomenon of being scratched. The term "chipping resistance" as used in the claims and specification of this application includes the resistance of the coating to "chipping".

[Concept of "impact resistance"] The concept of the term "impact resistance" used in the claims and the specification of the present application means that a large area is subjected to impact fracture when a load is applied in a short time. In particular, in the technical field of automobile paints, it also includes the phenomenon of scratches on the coating film of an automobile body when it collides with a large object.

[Correlation between impact resistance and chipping resistance]
Conventionally, in the technical field of powder coating, almost no difference in the concept of impact resistance and chipping resistance of the coating film was recognized,
Although the impact resistance of the coating film was sometimes emphasized, little attention was paid to the importance of the chipping resistance of the coating film.

That is, although the impact resistance of the coating film was evaluated, the chipping resistance of the coating film was rarely evaluated.

Further, since the difference between the concepts of impact resistance and chipping resistance of the coating film was hardly recognized, the correlation between impact resistance and chipping resistance was hardly studied.

For example, Japanese Patent Application Laid-Open No. 3-221567 discloses a technique for curing a powder coating by an acid / isocyanate reaction as a curing method of the powder coating, thereby improving the impact resistance of the coating. ing.

Even in JP-A-3-221567, the concept of chipping resistance of the coating film was not conceived at all, and only the impact resistance of the coating film was emphasized, and the importance of the chipping resistance of the coating film was completely ignored. Had not been careful.

From such a background, the present inventors have paid attention to the correlation between impact resistance and chipping resistance of the coating film formed by the powder coating material.

However, as a result of examining the correlation between impact resistance and chipping resistance of various coating films, the present inventors have found that they are not necessarily correlated.

As a result, the present inventors considered that the impact resistance and the chipping resistance of the coating film do not necessarily have the same effect manifestation mechanism, and therefore the concepts thereof are different.

[0127]

EXAMPLES In the specification of the present application, the examples, the production examples and the modes are for supporting the understanding of the content of the invention according to the present application, and the description does not limit the invention in any way. Not the one. "Part" and "%" in the explanation
Is a value by weight unless otherwise specified.

The results of the production examples, examples and comparative examples in the present specification are shown in the table, and the abbreviations of the raw materials used in the table are shown below. ST: Styrene MMA: Methyl Methacrylate nBMA: n-Butyl Methacrylate iBMA: Iso Butyl Methacrylate GMA: Glycidyl Methacrylate nBA: n-Butyl Acrylate PB-O: t-Butyl-Peroxy-2-ethylhexanoate DDA: Dodecanedioic Acid DDA -Ah: linear acid anhydride of dodecane diacid SBA: sebacic acid SBA-Ah: linear acid anhydride of sebacic acid TPA-Ah; linear acid anhydride of terephthalic acid DBU: (1,8-diazambicyclo ° [5.4.0]-
7-undecene) DBU-Fa: formate of DBU DBU-Oa: oleate of DBU PA-Ah: phthalic anhydride TPA: terephthalic acid TBA: tribenzylamine TEA: triethylamine TPP: triphenylphosphine M2HT: ARMENEN M2HT (Manufactured by Lion Akzo Co., Ltd.) [Production Example 1] Production of copolymer (A) 66.7 parts of xylene was charged in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen introducing tube, and refluxed. The temperature was raised with stirring to the temperature. After reaching the reflux temperature, the monomers shown in Table 1 and t-butyl-peroxy-2-ethylhexanoate (Perbutyl O, manufactured by NOF CORPORATION) as a polymerization initiator were added dropwise over 5 hours. ,
After further maintaining for 1 hour, 0.5 part of perbutyl O was added dropwise at 100 ° C. and maintained for 2 hours. The solvent was removed from the obtained polymerization solution to obtain a copolymer (A).

Various physical properties of the copolymer were measured by the following methods. (1) Glass transition temperature (Tg); based on monomer composition,
The Fox equation was calculated. (2) Number average molecular weight (Mn); measured by GPC using polystyrene as a standard. As shown in Table 1, various copolymers (A) were produced by changing the types of monomers and the monomer compositions.

Production Example 2 Production of Aliphatic Polycarboxylic Acid Linear Acid Anhydride (C) 1 mol of dodecane diacid and 1.1 mol of acetic anhydride were placed in a reaction vessel and heated to 150 ° C. In order to prevent acetic anhydride from flowing out of the system, the acetic acid produced was removed by a vacuum line and reacted for 5 hours. Then, immediately, it cooled and white solid was collect | recovered. The melting point of this compound is 73-82.
It was ℃. Sebacic acid linear anhydride is also produced by the same method using sebacic acid and has a melting point of 72 to 81.
℃ was obtained. Other linear carboxylic acid anhydrides were produced in the same manner.

[0131]

[Table 1] The powder coating materials obtained in the examples of the present specification were evaluated by the following methods. Non-common evaluation methods are described in the section of each example.

[Common Performance Evaluation] (1) Visual Appearance The appearance of the coating film was observed, and particularly smoothness and sharpness were evaluated. (2) Gloss The value (60 ° gloss) measured with a gloss meter is shown. (3) Impact resistance test (DuPont type impact resistance test) It was carried out in accordance with JIS K5400 6.13.3, and the weight had a weight of 1 kg. The numerical value of the evaluation result is shown by the drop height at which the coating film is cracked or peeled. (4) Adhesion value when measured with an Erichsen tester and the coating film peels off
(mm) was shown. (5) Use gauze impregnated with solvent-resistant xylol to reciprocate 50 times on the coating surface.
Observation was carried out after rubbing. Those with no trace were marked with ⊚, those with slight traces were marked with ○, and those with traces were marked with x.

Examples 1 to 8 and Comparative Examples 1 to 10 Preparation of Powder Coating Copolymer (A) produced by using the raw materials shown in Table 1 by the method shown in Production Example, aliphatic polycarboxylic acid (B ), An aliphatic polycarboxylic acid linear acid anhydride (C) and, if necessary, a salt (D) of a tertiary amine compound and an organic acid are mixed in the proportions shown in the table, and (A), (B) and ( Remix RL-4 (manufactured by Mitsui Toatsu Chemical Co., Inc., low-viscosity acrylic resin, flow control agent), tinuvin 1 per 100 parts by weight of C).
44 (manufactured by Ciba Geigy, light stabilizer), 1 part by weight each of benzoin (anti-armpitting agent), 2 parts by weight of TINUVIN 900 (manufactured by Ciba Geigy, UV absorber), and the mixture was heated using a heating roll. Then, the mixture was melt-kneaded under the condition of 90 ° C., cooled, and then finely pulverized by a pulverizer, and the section that passed through a 150-mesh sieve was collected to prepare a powder coating material. A powder coating material was produced by the method described in Production Example using the copolymer (A) shown in Table 1 as follows, electrostatically coated, and baked to evaluate the powder coating material. 2 shows. Table 3 shows the results of comparative experiments related to this.

[0134]

[Table 2]

[0135]

[Table 3] [Adjustment of test plate] Adjustment, coating and baking of test plate The powder paint obtained by the method of the present invention or the powder paint obtained in the comparative example was electrostatically applied onto a steel plate so as to have a film thickness of 60 to 70 μm. It was painted and baked at 140 ° C. for 30 minutes to obtain a test plate.

[Performance Evaluation] The coating material was evaluated by the above-mentioned common performance evaluation method and the following method. (1) Visual appearance By observing the appearance of the coating film, ◎ is particularly excellent in smoothness and sharpness, ○ is slightly uneven, slightly cloudy.
A product having poor smoothness and sharpness was rated as x. (2) Scratch resistance A zinc phosphate-treated steel sheet having a thickness of 0.8 mm was coated with a polyester-melamine-crosslinked black paint in a thickness of 30 μm and then baked to prepare a base-treated steel sheet. On the base treated steel sheet,
The powder coating composition was electrostatically coated to a film thickness of 60 to 70 μm and baked at 140 ° C. for 30 minutes to obtain a test plate. The coating film surface of the test plate was subjected to a scratch test by rubbing with a brush using a 0.3% cleanser suspension, and the gloss value was evaluated before and after the rubbing to calculate the gloss retention rate. An item having a gloss retention of 60% or more was evaluated as ◯ as a scratch-resistant coating film, 40 to 60% was evaluated as Δ, and a coating film having less than 40% was evaluated as x, which was not scratched. (3) Weather resistance test The accelerated test for 3000 hours by QUV tester is performed, and the gloss (60 °) of the coating film before and after the accelerated test is measured,
The gloss retention rate (%) was determined. A product having a gloss retention rate of 80% or more was rated as A, a product having a gloss retention rate of 70 to 80% was rated as O, and a product having a gloss retention of less than that was rated as X.
(4) Acid resistance test 40 vol% sulfuric acid was dropped on the surface of the coating film, and the temperature was 2 at 60 ° C.
After leaving it for 0 minutes, it was washed with water and the appearance of the coating film was observed. As a result, the sample having no trace is shown as ◯, the sample having a trace is shown as Δ, and the film having the coating eroded is shown as x. (5) Storage stability The powder coating composition was stored at 40 ° C. for 3 days and stored for 10 mm.
φ, 0.3g pelletized powder coating material was prepared and stuck on a plate, then kept vertical, at 140 ° C for 30 minutes,
The sagging state of the pellets when baked was measured. A product having good flowability was marked with ⊚, and a product with poor flow property was marked with x.

The powder coatings of Examples 1 to 7 shown in Table 2 are within the scope of the claims of the present invention, and the glycidyl group in the copolymer, the styrene content in the copolymer, the powder coating preparation It was an experiment in which the functional group ratio between the resin and the curing agent, the type of curing agent, and the type of curing catalyst were changed.These results show excellent physical properties of the coating film, appearance, excellent storage stability of the coating composition, etc. It shows

Comparative Example 1 is an example using a copolymer containing no styrene, and in this case, the storage stability of the paint was poor. Comparative Example 2 is a case where styrene was excessively contained in the copolymer, but in this case, the weather resistance of the coating film was poor.

Comparative Examples 3 and 4 are cases in which the glycidyl groups in the copolymer are out of the range of the present invention. If the glycidyl groups are too small, the physical properties and weather resistance of the coating film are poor, and if they are too large, the appearance and storage stability of the paint are stable. I was inferior.

Comparative Examples 5 and 6 are
When the aliphatic polycarboxylic acid as a curing agent and the aliphatic polycarboxylic acid linear anhydride were not used in combination, the coating appearance and coating physical properties were poor only with the aliphatic polycarboxylic acid, and Only with the polyhydric carboxylic acid linear anhydride, the coating film physical properties, weather resistance and storage stability of the coating were inferior.

Comparative Examples 7-8 are examples using an aromatic compound as a curing agent, and in this case, various performances were inferior. Comparative Example 9 is an example using phthalic anhydride which is a cyclic acid anhydride, but only the glycidyl group in (A) has reacted,
Since the cross-linking effect was small, the physical properties of the coating film were poor. Comparative Example 10
Is an experiment using a liquid tertiary amine, in which case the storage stability of the paint was poor.

Example 8 A test plate was prepared according to the coating method and baking of the powder coating material described below according to the compounding method described in Examples 1 to 7 without using an amine salt. Table 2 shows the results of evaluation of the powder coating material by the method described in 1. By performing the curing temperature at 160 ° C., satisfactory performance as a powder coating material was shown.

Coating and baking of powder coating material The powder coating material obtained by using the copolymer A-1 is electrostatically coated on a steel plate so as to have a film thickness of 60 to 70 μm, and the temperature is kept at 160 ° C. for 3 days.
Baking was performed for 0 minutes to obtain a test plate.

Examples 9 to 19, Comparative Examples 11 to 18 Preparation of Powder Coating Copolymer (A) produced by using the raw materials shown in Table 1 by the method shown in Production Example, aliphatic polycarboxylic acid (B) ), An aliphatic polycarboxylic acid linear acid anhydride (C) and, if necessary, a tertiary amine compound (E) having a melting point of about 20 to 150 ° C. in the proportions shown in the table, (A), (B) And total weight of (C) 10
For 0 parts by weight, Remixix RL-4 (manufactured by Mitsui Toatsu Chemicals, Inc., low-viscosity acrylic resin, flow regulator), TINUVIN 144 (manufactured by Ciba-Geigy, light stabilizer), benzoin (anti-armpit inhibitor) 1 part by weight each of TINUVIN 90
0 (UV absorber manufactured by Ciba-Geigy Co., Ltd.) was added in an amount of 2 parts by weight, and the above mixture was melt-kneaded using a heating roll at 90 ° C., cooled, and then finely pulverized with a pulverizer to obtain 150.
The sections that passed through the mesh sieve were collected to prepare a powder coating.

[Preparation of base-treated steel sheet] A 0.8-mm-thick matte steel sheet treated with zinc phosphate was coated with a polyester-melamine-crosslinked black paint in a thickness of 30 µm, and then baked to prepare a base-treated steel sheet. .

[Preparation of test plate] Preparation, coating and baking of test plate A powder coating material obtained by using the copolymer shown in Table 1 was applied on the above-mentioned pretreated steel plate so as to have a film thickness of 60 to 70 μm. Electrostatic coating was performed and baking was performed at 140 ° C. for 30 minutes to obtain a test plate.

The paints were evaluated by the common performance evaluation method and the following method. (1) Visual appearance By observing the appearance of the coating film, ◎ is particularly excellent in smoothness and sharpness, ◯ is excellent, slightly uneven, Δ slightly cloudy. A product having poor smoothness and sharpness was rated as x. (2) A scratch resistance test was conducted by rubbing the coating film surface of the scratch resistance test plate with a brush using a 0.3% cleanser suspension, and the gloss value was evaluated before and after the rubbing to evaluate the gloss retention rate. Was calculated. An item having a gloss retention of 60% or more was evaluated as ◯ as a scratch-resistant coating film, 40 to 60% was evaluated as Δ, and a film having less than 40% was evaluated as x as a scratch-resistant coating film. (3) Weather resistance test A QUV tester is used to perform an accelerated test for 4000 hours, and the gloss (60 °) of the coating film before and after the accelerated test is measured.
The gloss retention rate (%) was determined. A product having a gloss retention of 80% or more was marked as ⊚, a product having a gloss retention of 70 to 80% was marked as ◯, a product having a gloss retention of 70 to 60% was marked as Δ, and a product having a gloss retention of 60% or less was marked as x. (4) Acid resistance test 40 vol% sulfuric acid was dropped on the surface of the coating film, and the temperature was 2 at 60 ° C.
After leaving it for 0 minutes, it was washed with water and the appearance of the coating film was observed. As a result, the sample having no trace is shown as ◯, the sample having a trace is shown as Δ, and the film having the coating eroded is shown as x. (5) The storage-stable powder coating composition is stored at 30 ° C. and 90% relative humidity for 1 month to prepare a pellet-shaped powder coating of 10 mmφ and 0.6 g, and after sticking on a plate, Keep it vertical, 140
The sagging state of the pellet was measured when baked at 30 ° C. for 30 minutes. Items hung over 20 mm are ○, 10-20
mm is Δ, and less is x. The results of evaluation of the powder coating material by the above method are shown in Tables 4 and 5, and the related comparative example is shown in Table 6.

[0148]

[Table 4]

[0149]

[Table 5]

[0150]

[Table 6] The powder coatings of Examples 9 to 19 shown in Tables 4 and 5 are within the scope of the claims of the present invention, and the glycidyl group in the copolymer,
It was an experiment in which the styrene content in the copolymer, the functional group ratio between the resin and the curing agent at the time of powder coating production, the type of curing agent, and the type or amount of the curing catalyst were changed. It shows the physical properties and appearance of the film, and the excellent storage stability of the coating composition.

Comparative Example 10 is an example using a copolymer containing no styrene. In this case, the appearance and gloss of the coating film and the storage stability of the coating material were poor. Comparative Example 11 is a case where the copolymer contains an excess of styrene, in which case the weather resistance of the coating film was poor.

Comparative Examples 12 and 13 are cases in which the glycidyl groups in the copolymer are out of the range of the present invention. When the glycidyl groups are too small, the physical properties and weather resistance of the coating film are poor, and when the glycidyl groups are too large, the appearance and storage stability of the paint are stable. I was inferior.

Comparative Examples 14 and 15 are cases in which the aliphatic polycarboxylic acid and the aliphatic polycarboxylic acid linear anhydride, which are curing agents, were not used together in the production of the powder coating material. The appearance of the coating film and the physical properties of the coating film were poor only with the polycarboxylic acid, and the physical properties of the coating film and the storage stability of the coating were poor with only the linear polyanhydride of the aliphatic polycarboxylic acid.

Comparative Example 16 was an experiment in which a liquid tertiary amine was used as a curing catalyst, and Comparative Example 17 was an experiment in which triphenylphosphine was used as a curing catalyst. In both cases, the storage stability of the coating was poor. .

Example 20 A powder coating material was prepared without using an amine compound, and a test plate was prepared according to the coating of the powder coating material and the above baking (however, the baking temperature was changed to 160 ° C.), and Example 9 was used.
The results of evaluation of the powder coating material by the method described in -19 are shown in Table 5. By performing the curing temperature at 160 ° C., satisfactory performance as a powder coating material was shown.

Examples 21-23, Comparative Examples 19-20 Preparation of powder coating Copolymer (A) A-1, aliphatic polycarboxylic acid (B), aliphatic polycarboxylic acid shown in Table 1 The ratio of linear acid anhydride (C), a salt of a tertiary amine compound and an organic acid (D) if necessary, or a tertiary amine compound (E) having a melting point of about 20 to 150 ° C. and titanium oxide is shown in Table 7. Blended with
Total weight of (A), (B), (C) and titanium oxide 10
For 0 parts by weight, Remixix RL-4 (manufactured by Mitsui Toatsu Chemicals, Inc., low-viscosity acrylic resin, flow regulator), TINUVIN 144 (manufactured by Ciba-Geigy, light stabilizer), benzoin (anti-armpit inhibitor) 1 part by weight each of TINUVIN 90
0 (UV absorber manufactured by Ciba-Geigy Co., Ltd.) was added in an amount of 2 parts by weight, and the above mixture was melt-kneaded using a heating roll at 90 ° C., cooled, and then finely pulverized with a pulverizer to obtain 150.
The sections that passed through the mesh sieve were collected to prepare a powder coating.

[Preparation of test plate] Preparation, coating and baking of test plate The powder coating material obtained by using the copolymers shown in Table 7 was coated on the cation electrodeposition plate to a film thickness of 60 to 70 μm. Electrostatic coating was performed and baking was performed at 160 ° C. for 30 minutes to obtain a test plate.

The paint was evaluated by a common performance evaluation method and the following method. (1) Visual appearance By observing the appearance of the coating film, ◎ is particularly excellent in smoothness and sharpness, ◯ is excellent, slightly uneven, Δ slightly cloudy. A product having poor smoothness and sharpness was rated as x. (2) Chipping test (stepping stone type impact test) Testing method for automotive coatings in the United States SAE-J400 and AS
A gravelometer (manufactured by Suga Test Instruments Co., Ltd.) according to TM D-370 was used. The coated steel sheet is left in a freezer at -20 ° C for 4 hours, and then immediately cooled in a dry ice / methanol bath at -30 ° C for 5 minutes, and the coated steel sheet is pulled out from the dry ice / methanol bath and used as a gravelometer. 50 g of road crushed stones were collided at once in each set. . The time required from the withdrawal from the dry ice methanol bath to the spraying of crushed stone was within 5 seconds. The pressure of the compressed air used for blowing was 4 Kgf / cm ² (gauge). The steel plate damaged by the collision of crushed stones was left at room temperature for 10 minutes, and then the coating film which was about to be peeled off was completely peeled off using a tape. The quality of chipping resistance was expressed by the average diameter of scratches. Therefore, the smaller the scratch diameter, the better the chipping resistance. A film having a scratch diameter of 1.5 mm or less was determined as a coating film having good chipping resistance. Experimental results and related comparative examples are shown in Table 7.

[0159]

[Table 7] The powder coatings of Examples 21 to 23 shown in Table 7 are experiments carried out within the scope of the claims of the present invention, and these results show excellent coating film physical properties, appearance, and excellent storage of coating compositions. It shows stability and chipping resistance. Comparative Example 18,
No. 19 is a case where the aliphatic polycarboxylic acid as a curing agent and the aliphatic polycarboxylic acid linear anhydride were not used together in the production of the powder coating, and the coating was performed only with the aliphatic polycarboxylic acid. The solvent resistance and chipping resistance of the film were inferior, and only the aliphatic polycarboxylic acid linear anhydride was inferior in the coating film physical properties, adhesion and chipping resistance. Example 24 (Yellow tint and yellowing resistance test) An acrylic-melamine crosslinked white paint was applied to a zinc phosphate treated 0.8 mm thick satin finished steel sheet in a thickness of 30 μm to prepare a base treated steel sheet. The powder coatings of Examples 1, 5, and 7 and Comparative Example 2 were applied to the surface-treated steel sheet to a film thickness of 60 to 70 μm.
Electrostatic coating and baking at 140 ° C. for 30 minutes to obtain a test plate. Difference in whiteness (Δb value) between the test plate coating film and the coating film of the ground-treated steel sheet only using a color difference meter
Was measured to determine the degree of yellowness. Those having a Δb value of 1.0 or more were judged to have a yellow tint. Q the test plate
A 3000-hour accelerated test was performed using a UV tester, and a yellowing resistance test was conducted in the same manner as the above Δb value. QUV
It was judged that 0.5 or more yellowed compared with the Δb value before the tester measurement. The test results are shown below. Experiment No. Powder coating Δb of copolymer (A) Yellowing resistance styrene content (wt%) 24-1 Example 5 5 0.1 0.3 24-2 Example 1 10 0.3 0.5 24 -3 Example 7 25 0.8 0.9 24-4 Comparative Example 2 45 3.5 4.4 (Comparative Example) As shown above, the styrene content of the copolymer (A) exceeds 30 wt%. And the coating becomes yellowish,
Moreover, it became easy to turn yellow.

Examples 25-26, Comparative Examples 21-22 [Preparation of Test Plate] Preparation, Painting and Baking of Test Plate A zinc-phosphate treated steel plate was coated with a white paint of acrylic-melamine cross-linked with a coating film of 30 μm. , Adjusted the base treated steel sheet. A silver metallic acrylic-melamine cross-linking aqueous base coat was applied onto the surface-treated steel sheet so that the coating film after baking was 15 μm, set for 10 minutes, and then pre-dried at 100 ° C. for 5 minutes. Then Table 8
The powder coating material of the present invention described above was electrostatically coated to a film thickness of 60 to 70 μm, and baked at 140 ° C. for 30 minutes to obtain a test plate. The coating film was evaluated by the following methods. (1) Visual appearance By observing the appearance of the coating film, ◎ is particularly excellent in smoothness and sharpness, ◯ is excellent, slightly uneven, Δ slightly cloudy. A product having poor smoothness and sharpness was rated as x. (2) Adhesion The value (mm) when the coating film was peeled off was measured by an Erichsen tester. (3) Weather resistance test A QUV tester is used to perform an accelerated test for 4000 hours, and the gloss (60 °) of the coating film before and after the accelerated test is measured.
The gloss retention rate (%) was determined. A product having a gloss retention rate of 80% or more was evaluated as ⊚, a product having a gloss retention of 70 to 80% was evaluated as ∘, a product having a gloss retention of 60 to 70% was evaluated as Δ, and a product having a gloss retention of less than that was evaluated as x. Table 8 shows the results of evaluation and comparison experiments of the powder coating material by the above method.

[0161]

[Table 8] The powder coating materials of Examples 25 to 26 shown in Table 8 are within the scope of the claims of the present invention, and all of these materials exhibit excellent coating film appearance and physical properties. On the other hand, Comparative Example 2
No. 1 is a curing agent used is only an aliphatic polyvalent carboxylic acid, Comparative Example 22 is a curing agent used is only an aliphatic polyvalent carboxylic acid linear anhydride, both are compared with the examples The coating film appearance was inferior.

[0162]

EFFECTS OF THE INVENTION When the coating composition of the present invention is used as a coating composition for automobiles, it has excellent appearance, physical properties, weather resistance, storage stability of the coating, no yellowing of the coating, and excellent yellowing resistance. Particularly, it can be preferably used as an intermediate coating or top coating for automobiles and automobile parts.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI B05D 7/24 B05D 7/24 302P C09D 5/46 C09D 5/46 163/00 163/00 (72) Inventor Mitsuyuki Mizoguchi Kanagawa 1190 Kasama-cho, Sakae-ku, Yokohama Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Takahisa Miyawaki 1190, Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Kosuke Suekaka Sakae-ku, Yokohama, Kanagawa Kasama-cho 1190 Mitsui Toatsu Chemical Co., Ltd. (56) Reference JP-A-5-112743 (JP, A) JP-A-50-51542 (JP, A) JP-A-6-173089 (JP, A) Kai 57-3868 (JP, A) JP 60-86175 (JP, A) JP 6-1944 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 5 / 03 C09D 5/46 C09D 163/00-163/10 B05D 7/14 B05D 7/24

Claims (29)

(57) [Claims] 1. Monomers (a1), (a2) and (a3)
60 parts by weight over 20 parts by weight of the ethylenically unsaturated monomer having at least one glycidyl group and at least one unsaturated double bond in the molecule as (a1), ) As styrene 1-30
Parts by weight and (a3) 10 to 79 parts by weight of an ethylenically unsaturated monomer having neither a carboxyl group nor a tertiary butyl ester group in the molecule, and polymerized in a reaction system A thermosetting powder coating material containing the resulting copolymer (A), an aliphatic polycarboxylic acid (B), and an aliphatic polycarboxylic acid linear acid anhydride (C). 2. (A) (B) and (C) according to claim 1.
In addition, a thermosetting powder coating material further containing a salt (D) of a tertiary amine compound and an organic acid and / or a tertiary amine compound (E) having a melting point of 20 ° C to 150 ° C. 3. The glass transition temperature of the component (A) according to claim 1 determined by the Fox equation is 20 to 100 ° C., and the number average molecular weight is 1,000 to 30,000. Or the thermosetting powder coating described above. 4. (A) (B) and (C) according to claim 3.
Containing 0.1 to 1.2 equivalents of carboxyl groups in the aliphatic polycarboxylic acid (B) per 1 equivalent of glycidyl groups in the copolymer (A) molecule, aliphatic polycarboxylic acid The acid anhydride group in the linear anhydride (C) is 0.1 to 1.2 equivalents, and the total of the carboxyl group in (B) and the acid anhydride group in (C) is 0.5 to 2 Equivalent amount of thermosetting powder coating. 5. The aliphatic polycarboxylic acid has 0.3 to 0.8 equivalents of carboxyl groups in the aliphatic polycarboxylic acid (B) with respect to 1 equivalent of the glycidyl group in the copolymer (A). The acid anhydride group in the acid linear acid anhydride (C) is 0.2 to 0.6 equivalent, and the carboxyl group in the aliphatic polyvalent carboxylic acid (B) and the aliphatic polyvalent carboxylic acid linear The total amount of acid anhydride groups in the acid anhydride (C) is 0.7 to 1.2 equivalents.
2. A thermosetting powder coating material according to any one of 1. 6. The following component (a1) comprises 20 to 60% by weight of a monomer having a glycidyl group and an unsaturated double bond,
As (a2), 1 to 30% by weight of styrene and (a3)
As other monomers (a1) and (a2), which are radically copolymerizable with 10 to 79% by weight of another monomer having no carboxyl group in the molecule and having a glass transition temperature of 20 to 10%.
Copolymer (A) having 0 ° C. and number average molecular weight of 2000 to 10,000, aliphatic dibasic acid (B), aliphatic polycarboxylic acid linear acid anhydride (C), and organic amine salt (D) And the carboxyl group in the aliphatic dibasic acid (B) is 0.1 to 1.2 with respect to one glycidyl group in the copolymer (A).
The number of acid anhydride groups in the aliphatic polycarboxylic acid linear acid anhydride (C) is 0.1 to 1.2 per 1 glycidyl group in the copolymer (A), and (B ) And the total amount of acid anhydride groups in the aliphatic polycarboxylic acid linear acid anhydride (C) are 0.5 to 2 per 1 glycidyl group, and the organic amine salt (D) is The thermosetting powder coating composition according to claim 2, which is formed by using 0.01 to 3 parts by weight based on 100 parts by weight of the total of the compositions (A), (B) and (C). 7. Monomers (a1), (a2) and (a3)
20 to 60 as a monomer (a1) having a glycidyl group and an unsaturated double bond with respect to the total weight of 100 parts by weight of
Parts by weight, 1 to 30 parts by weight of styrene as (a2), and 10 to 79 parts by weight of a monomer not having a carboxyl group and a glycidyl group in the molecule as (a3). Copolymer (A) having a glass transition temperature of 20 to 100 ° C. and a number average molecular weight of 2,000 to 10,000, an aliphatic polycarboxylic acid (B), and an aliphatic polycarboxylic acid linear acid anhydride. In a thermosetting powder coating composition containing (C) and a solid amine compound (E), in an aliphatic polycarboxylic acid (B) with respect to 1 equivalent of glycidyl groups in a molecule of a copolymer (A). The carboxyl group of is 0.1
1.2 equivalents, the acid anhydride group in the aliphatic polycarboxylic acid linear acid anhydride (C) is 0.1 to 1.2 equivalents,
The total of the carboxyl group in (B) and the acid anhydride group in (C) is 0.5 to 2 equivalents, and the solid amine compound (E) is the above composition (A) or (B). 3. The thermosetting powder coating material according to claim 2, which is 0.01 to 3 parts by weight with respect to 100 parts by weight as the total weight of (C). 8. A tertiary amine compound is added to 100 parts by weight in total of the copolymer (A), the aliphatic polycarboxylic acid (B) and the aliphatic polycarboxylic acid linear acid anhydride (C). The thermosetting powder coating material according to claim 2, wherein the salt (D) with an organic acid is 0.01 to 3 parts by weight. 9. A melting point of 20 ° C. to 100 parts by weight of the total of the copolymer (A), the aliphatic polycarboxylic acid (B) and the aliphatic polycarboxylic acid linear acid anhydride (C). The tertiary amine compound (E) at 150 ° C. is 0.01 to 3 parts by weight,
The thermosetting powder coating material according to claim 2. 10. A salt (D) of a tertiary amine compound and an organic acid is 1,8-diazabicyclo [5.4.0] -7.
-The thermosetting powder coating composition according to claim 8, which is a salt of undecene and an organic acid. 11. A tertiary amine compound (E) having a melting point of 20 ° C. to 150 ° C. has a structure of N-methyl-N, N-dialkyl (wherein the alkyl group has 2 to 30 carbon atoms) amine structure.
The thermosetting powder coating material according to claim 9, which is at least one kind of compound selected from the group of primary amine compounds. 12. The copolymer (A) is a monomer (a1),
(A2), (a3) to 100 parts by weight in total, (a
The heat according to claim 3, which is obtained by polymerizing in a reaction system containing 1): 20 to 60 parts by weight (a2): 10 to 30 parts by weight and (a3): 10 to 70 parts by weight. Curable powder coating. 13. The copolymer (A) is a monomer (a1),
(A2), (a3) to 100 parts by weight in total, (a
The thermosetting powder according to claim 3, which is obtained by polymerization in a reaction system containing 1): 25 to 50 parts by weight (a2): 10 to 20 parts by weight and (a3): 25 to 65 parts by weight. Body paint. 14. The thermosetting powder coating composition according to claim 13, wherein the number average molecular weight of the copolymer (A) is 2,000 to 10,000. 15. The thermosetting powder coating composition according to claim 14, wherein the aliphatic polycarboxylic acid linear acid anhydride (C) is a dehydration condensation product of the aliphatic polycarboxylic acid (B). 16. The thermosetting powder coating composition according to claim 14, wherein the aliphatic polycarboxylic acid (B) is dodecane diacid. 17. The aliphatic polycarboxylic acid linear acid anhydride (C) is a dehydration condensation product of dodecane diacid.
4. The thermosetting powder coating material according to 4. 18. The composition according to claim 15, wherein the aliphatic polycarboxylic acid (B) is dodecane diacid. 19. A method of coating an automobile body or automobile parts with the thermosetting powder coating composition according to claim 1. 20. A method of overcoating an automobile body or automobile parts using the thermosetting powder coating composition according to claim 1. 21. The thermosetting powder coating is a top coating material of claim 1 or claim 2 on the primer coating of pigmented or metallic aqueous paint was electrostatically coated, an undercoat paint and top coat paint A painting method characterized by baking at the same time. 22. A method for applying an intermediate coating to a vehicle body or an automobile part of an automobile using the coating composition according to claim 1 or 2. 23. The method according to claim 1 or 2 for forming a coating film.
A method of using the paint according to any one of 1. 24. A coating film obtained by using the coating composition according to claim 1. 25. An automobile coated with the coating composition according to claim 1 or 2. 26. An automobile part coated with the coating composition according to claim 1 or 2. 27. A raw material containing the paint component according to claim 1 or 2 is melt-kneaded at a temperature of 40 to 130 ° C.,
Next, a method for producing a thermosetting powder coating material, which comprises cooling and then pulverizing. 28. A coating method, wherein the thermosetting powder coating material produced in claim 27 is adhered to an object to be coated and baked at 100 to 180 ° C. 29. A coating method, wherein the thermosetting powder coating material according to claim 27 is attached to an object by an electrostatic coating method and baked at 100 to 180 ° C.