JP3496767B2 - Resin composition for thermosetting powder coatings - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel resin composition for thermosetting powder coatings, which can simultaneously achieve excellent smoothness and coating performance such as weather resistance. When blended, it can be suitably used as a thermosetting powder coating material on the surface of various metals, plastic moldings or building materials.

[0002]

2. Description of the Related Art Powder coatings, which do not contain any organic solvent in their coating composition, have recently been in worldwide demand as coatings that can comply with the strict regulations of organic solvent emission in each country. ing. Above all, vinyl (acrylic) resin-based powder coatings have excellent weather resistance compared to other powder coatings, that is, polyester resin-based powder coatings and epoxy-based powder coatings. It is used in home appliances and other applications that require high weather resistance. On the other hand, vinyl (acrylic) resin-based powder coatings have the drawback that the melt viscosity in the film-forming process is higher than other resin-based powder coatings, and as a result, only coatings with poor smoothness can be obtained. Was there. In order to overcome this drawback, a method of reducing the melt viscosity by copolymerizing styrene with another vinyl-based monomer has been conventionally used, but it is an advantage of vinyl (acrylic) resin by using styrene. Weather resistance is sacrificed.

Various studies have already been made on the problem of compatibility between the smoothness and weather resistance of the coating film. For example, a method in which styrene and cyclohexyl methacrylate are used in combination (JP-A-50-124934) or a method in which styrene and tert-butyl (meth) acrylate are used in combination (JP-A-52-38541 and JP-A-4-359971). ), Etc., but all of them are merely methods in which styrene is used in combination with other acrylic monomers, and vinyl resins for powder coatings that do not contain styrene in the resin component that can achieve smoothness and weather resistance at the same time ( No acrylic) resin composition has been found.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to various metals,
A vinyl-based copolymer with good storage stability that shows good smoothness on the surface of plastic moldings and building materials, and easily forms a coating film with excellent weather resistance, water resistance, solvent resistance, and acid resistance. An object of the present invention is to provide a resin composition for thermosetting powder coating material containing a united resin.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a vinyl-based monomer having a specific chemical structure in its side chain is copolymerized in a vinyl resin. As a result, it has been found that the melt viscosity and photochemical stability of the conventional vinyl resin can be improved and good smoothness and coating performance such as weather resistance can be achieved at the same time, and the present invention has been completed.

That is, the present invention comprises (A) 5 to 30 % by weight of a repeating unit derived from a vinyl monomer represented by the following general formula (1):

[0007]

[Chemical 2]

(In the formula, R ¹ is a hydrogen atom or a methyl group, and R ² is bicyclo [2.2.1] heptyl, 6-methylbicyclo [2.2.1] heptyl, 5,6-dimethylbicyclo. [2.2.1] heptyl, 1-methylbicyclo [2.2.1] heptyl, 6-ethylbicyclo [2.
2.1] heptyl, 1,7,7-trimethylbicyclo [2.2.1] heptyl, bicyclo [4.4.0] decyl, tricyclo [3.3.1.1 ^3,7 ] decyl, tricyclo [ 4.4.0.1 ^2,5 ] undecyl, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecyl,
Pentacyclo [6.6.1.1 ^3,6 . 1 ^{10, 13} .
0 ^2,7 . 0 ^9,14] hexadecyl, hexacyclo [6.6.1.1 ^3,6. 1 ^{10, 13} . 0 ^2,7 . 0
^[9,14 ] heptadecyl, and a polycyclic aliphatic hydrocarbon group having 7 to 30 carbon atoms selected from those substituted with a substituent, and n represents an integer of 0 to 4. ) (B) 5 to 30% by weight of a repeating unit derived from a vinyl-based monomer having a glycidyl group in its chemical structure, and (C)
Become recurring units derived from other non-reactive vinyl monomer from 40 to 90 wt%, a range of the glass transition temperature of 50 to 100 ° C., a weight average molecular weight of 5 0
The present invention provides a resin composition for a thermosetting powder coating material, which contains a vinyl-based copolymer resin in the range of 0-50000. Hereinafter, the present invention will be described in detail.

The repeating unit (A) contained in the vinyl copolymer resin used as the resin component of the resin composition for thermosetting powder coating material of the present invention is represented by the general formula (1). It is a repeating unit derived by polymerizing a monomer. R ² in the general formula (1) is a polycyclic aliphatic hydrocarbon group, and is an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxyl group, an acyl group, a hydroxyl group, an amino group, a nitrile group, a carboxyl group, Those in which various substituents such as a halogen atom are substituted are also included. R ² is a polycyclic aliphatic hydrocarbon group having 7 to 30 carbon atoms, and a particularly preferable one is a polycyclic aliphatic hydrocarbon group having 7 to 15 carbon atoms. This polycyclic aliphatic hydrocarbon group
Is, Ru der the next thing.

Bicyclo [2.2.1] heptyl

[Chemical 3]

6-Methylbicyclo [2.2.1] heptyl

[Chemical 4]

5,6-Dimethylbicyclo [2.2.1]
Heptyl

[Chemical 5]

1-Methylbicyclo [2.2.1] heptyl

[Chemical 6]

6-ethylbicyclo [2.2.1] heptyl

[Chemical 7]

1,7,7-trimethylbicyclo [2.
2.1] Heptyl

[Chemical 8]

Bicyclo [4.4.0] decyl

[Chemical 9]

Tricyclo [3.3.1.1 ^3,7 ] decyl

[Chemical 10]

[0018]

Tricyclo [4.4.0.1 ^2,5 ] undecyl

[Chemical 12]

Tetracyclo [4.4.0.1 ^2,5 . 1
^7,10 ] dodecyl

[Chemical 13]

Pentacyclo [6.6.1.1 ^3,6 . 1
^10,13 . 0 ^2,7 . 0 ^9,14 ] Hexadecyl

[Chemical 14]

[0022]

Hexacyclo [6.6.1.1 ^3,6 . 1
^10,13 . 0 ^2,7 . 0 ^9,14 ] Heptadecyl

[Chemical 16]

Further, various polycyclic aliphatic hydrocarbon groups such as an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxyl group, an acyl group, a hydroxyl group, an amino group, a nitrile group, a carboxyl group and a halogen atom can be used. The thing etc. which the substituent substituted were mentioned.

Typical examples of these vinyl monomers include, for example, tetracyclo [4.4.0.
1 ^2,5 . 1 ^7,10 ] dodecyl acrylate, tricyclo [4.4.0.1 ^2,5 ] undecyl acrylate, bicyclo [4.4.0] decyl acrylate, 1,7,7-
Trimethylbicyclo [2.2.1] heptyl acrylate, bicyclo [2.2.1] heptyl acrylate, tricyclo [3.3.1.1 ^3,7 ] decylmethyl acrylate, tetracyclo [4.4.0.1 ^{2] , 5} . 1 ^7,10] dodecyl methacrylate, tricyclo [4.4.0.1
^2,5 ] undecyl methacrylate, bicyclo [4.4.
0] decyl methacrylate, 1,7,7-trimethylbicyclo [2.2.1] heptyl methacrylate, tricyclo [3.3.1.1 ^3,7 ] decyl methacrylate, tricyclo [3.3.1.1 ^{3, 7} ] Decylmethyl methacrylate and the like. These vinyl-based monomers may be used alone or in combination of two or more.

The repeating unit (B) of the vinyl-based copolymer resin used as the resin component of the resin composition for thermosetting powder coating material of the present invention is a vinyl-based monomer having a glycidyl group in its chemical structure. It is a repeating unit derived by polymerization. Vinyl monomers having a glycidyl group in the chemical structure, compounds having both a vinyl group and a glycidyl group in its structure For example, such as glycidyl acrylate, beta-methyl glycidyl acrylate,
Glycidyl methacrylate, β-methylglycidyl methacrylate and other acrylic acid or methacrylic acid glycidyl esters, allyl alcohol glycidyl ethers or methyl glycidyl ethers, methallyl alcohol glycidyl ethers or methyl glycidyl ethers, N-glycidyl acrylic acid amides, etc. vinylsulfonic acid glycidyl. These vinyl-based monomers having a glycidyl group in their chemical structure can be used alone or in combination of two or more.

Further, the repeating unit of (C) is a repeating unit derived by polymerizing a non-reactive vinyl monomer other than the vinyl monomer for deriving the repeating units of (A) and (B). is there. Other non-reactive vinyl monomers include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, phenyl methacrylate. , Benzyl methacrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-
Butyl acrylate, isobutyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate,
Phenyl acrylate, methacrylic acid or acrylic acid esters having no reactive functional group such as benzyl acrylate, or styrene, α-methylstyrene, vinyltoluene, fumaric acid dialkyl ester, itaconic acid dialkyl ester, acrylonitrile, methacrylonitrile, Examples thereof include ethylenically unsaturated monomers such as vinyl acetate, vinyl propionate, and vinyl chloride.
These other non-reactive vinyl monomers can be used alone or in combination of two or more.

The vinyl copolymer resin used in the present invention contains 5 to 30% by weight, preferably 10 to 30% by weight of repeating units derived from (A) the vinyl monomer represented by the general formula (1). 5% to 30% by weight, preferably 10 to 30% by weight, and (C) other non-reacting units, and (B) a repeating unit derived from a vinyl-based monomer having a glycidyl group in its chemical structure. 40 to 90% by weight, preferably 40 to 90% by weight of a repeating unit derived from a polymerizable vinyl monomer
It consists of 80% by weight. If the content of the repeating unit (A) is less than 5% by weight, the curing is not sufficient, and if it exceeds 30% by weight, the coating film becomes too brittle and the coating film performance deteriorates. Further, if the content of the repeating unit (B) is less than 5% by weight, the curability is insufficient, and if it exceeds 30% by weight, the degree of curing proceeds excessively, resulting in poor coating performance. In addition, the vinyl copolymer resin may have other repeating units other than the above within the range not impairing the object of the present invention.

The glass transition temperature of the vinyl copolymer resin used in the present invention is in the range of 50 to 100 ° C. If the glass transition temperature of this resin is less than 50 ° C., the stability as a resin for powder coating material is extremely poor, and blocking occurs and the powder cannot exist stably.
On the other hand, when the glass transition temperature of this resin exceeds 100 ° C., the melt viscosity is too high and the leveling property at the time of curing is poor, and a uniform and smooth coating film cannot be obtained.

Furthermore, the weight average molecular weight of the vinyl copolymer resin used in the present invention must be in the range of 5 000 to 50000, preferably from 5 000 to 2
The range is 0000. The weight average molecular weight of this resin is 5
If it is less than 000, the physical properties of the coating film are insufficient and the coating film performance such as coating film strength or solvent resistance is deteriorated. On the other hand, when the weight average molecular weight of this resin exceeds 50,000, the melt viscosity is too high and the leveling property at the time of curing is poor, and a uniform and smooth coating film cannot be obtained.

The vinyl-based copolymer resin used in the resin composition for thermosetting powder coating composition of the present invention comprises a vinyl-based monomer of the general formula (1), a vinyl-based monomer having a glycidyl group in its chemical structure, and It can be obtained by copolymerizing other non-reactive vinyl monomers. The polymerization method for synthesizing the vinyl-based copolymer resin used in the resin composition for the thermosetting powder coating material of the present invention is not limited at all, and a commonly used solution polymerization method, melt polymerization method, Emulsion polymerization method, suspension polymerization method, dispersion polymerization method, radiation polymerization method and the like are applicable. Further, even if a chain transfer agent such as mercaptans is used as a method for controlling the molecular weight of the vinyl-based copolymer resin, there is no effect.

The resin composition for a thermosetting powder coating material of the present invention has a functional group capable of reacting with the glycidyl group of the repeating unit (B) contained in the vinyl-based copolymer resin in the molecule.
A desired thermosetting powder coating material is put into practical use by blending a hardener that is solid at room temperature. In this case, examples of the curing agent include dibasic acid compounds such as sebacic acid, azelaic acid and dodecadioic acid or phthalic anhydride as a curing agent for epoxy-functional vinyl resin.
Examples thereof include acid anhydride compounds such as hexahydrophthalic anhydride and maleic anhydride.

The vinyl-type copolymer resin in the resin composition for thermosetting powder coating material of the present invention is used as a main resin component, and its compounding ratio is not particularly limited and may be appropriately selected. It may be selected, but it is usually in the range of 5 to 100% by weight in the resin component, preferably 20.
It may be in the range of ˜100 wt%. Further, the mixing ratio of the curing agent is not particularly limited and may be appropriately selected, but the molar ratio of the reactive group of the curing agent to the functional group of the resin component is usually in the range of 0.5 to 1.5. , Preferably within the range of 0.8 to 1.2.

The thermosetting powder coating resin composition of the present invention contains various resins such as epoxy, acrylic, polyester, polyamide, etc., which are added in addition to ordinary powder coatings, phthalocyanine-based and indanthrone-based resins. , Flavanthlon-based, quinacridone-based organic pigments and titanium dioxide,
Inorganic pigments such as iron oxide, chromium oxide and carbon black, coloring aids or UV absorbers, light stabilizers, antistatic agents, anti-armpit agents, antiblocking agents, antioxidants,
If necessary, one or more additives for paints such as a plasticizer, a flow control agent, and a curing catalyst can be added, and they are put to practical use as a powder paint. Appropriate amounts of these components may be selected according to the required characteristics. Further, these components may be added when mixing the vinyl copolymer resin and the curing agent, or may be mixed in advance with the vinyl copolymer resin or the curing agent before mixing the both. Good.

In producing the powder coating material, a so-called dry method using a melt-kneader such as a heating roll, an extruder or a kneader can be applied. Regarding the coating method of the powder coating material, the coating object is coated by a well-known coating method such as an electrostatic coating method or a fluidized dipping method, and usually 140 to 2
By baking at a temperature of 00 ° C. for 5 minutes to 2 hours, a sufficiently cured coating film can be obtained. The thickness of the coating film may be appropriately selected as necessary and is usually 20 to 20.
The range may be 0 μm, preferably 40 to 100 μm.
The range is m.

[0036]

EXAMPLES Next, the present invention will be described more specifically by way of examples. The present invention is not limited to these examples. In the examples, the coating film performance test was performed by the following method. (1) Coating smoothness The centerline average roughness of the powder coating cured coating film surface was measured using a surface roughness meter Surfcom manufactured by Toyo Seimitsu Co., Ltd. (2) Adhesiveness JIS K5400 8.5.2. It was measured by. (3) Solvent resistance The cured coating film was rubbed with a flannel dipped in xylene 100 times, and the change in coating film state was evaluated according to the following criteria. ◯: No change in coating film. Δ: Whitening of coating film. X: Coating film dissolution.

(4) Accelerated weather resistance A dew panel light control weather meter (manufactured by Suga Test Instruments Co., Ltd.) was used to measure the time for a clear cured coating film crack generation test. (5) Storage stability The powder coating material was stored at 30 ° C for 30 days, and changes in the coating material state were evaluated according to the following criteria. ◯: No change. Δ: Paint aggregation. X: Paint blocking.

Example of resin production1 Counter equipped with thermometer, stirrer, reflux condenser, nitrogen inlet tube
Display ethyl acetate in the reaction container.1In addition to the amount described in
Replace the air in the reaction vessel with a gas and heat to reflux with stirring.
Let Table there1Each monomer mixture described in
Add the mixture dropwise over 2 hours and then under reflux.
After holding for 30 minutes at1The additional catalyst components shown in
The remaining monomer is polymerized for 2 hours under reflux,
CompleteMetable1Has the resin composition and characteristic values shown in
Vinyl copolymer resin1Got Next, for synthesis under reduced pressure
Solidify by distilling off the solvent ethyl acetate,
After pulverizing, dry under reduced pressure to remove residual solvent,
A vinyl resin for powder coating was obtained. Also, powderWasOf resin
Melt viscometer (measurement device)
Name: SOLIQUID METER MR300, Rheology Co., Ltd.
Table 3 shows the values measured by the same company.

Resin Production Comparative Examples 1 and 2 In the same manner as in Resin Production Example 1 , the solvents and monomers shown in Table 2 were added to polymerize, solidify, crush and dry under reduced pressure.
The residual solvent was removed to produce an acrylic resin for powder coating.
In addition, in Table 1 and Table 2, tetracyclododecyl acrylate is tetracyclo [4.4.0.1 ^2,5 .
1 ^7,10 ] dodecyl acrylate, and isobornyl acrylate is 1,7,7-trimethylbicyclo [2.2.1] heptyl acrylate.

Example 1 Manufacture of powder coating material: 2,000 parts by weight of triglycidyl isocyanurate as a curing agent was added to 1000 parts by weight of the resin obtained in Resin Production Example 1.
10 parts by weight of TINUVIN 900 (trade name: manufactured by Ciba Geigy) as an ultraviolet absorber, and SANOL LS as a light stabilizer
10 parts by weight of 440 (trade name: manufactured by Sankyosha), 5 parts by weight of Resmix RL-4 (trade name: manufactured by Mitsui Toatsu Chemical Co., Inc.) as a leveling agent, and 5 parts by weight of benzoin as a pinhole inhibitor, Mix well with a Henschel mixer. Next, the same mixture was melt-kneaded in a heating kneader at 80 ° C. for 2 passes, pulverized with a sample mill, and finally 150
The powder was obtained by classification with a sieve of mesh. Method for preparing coating film performance test plate Bellcoat No. 1 was used as a metallic base coat on the cationic electrodeposition / intermediate coating plate. 6000BCG2 (trade name: manufactured by NOF CORPORATION) was applied for about 15 μm and then flashed at 140 ° C. for 5 minutes. Next, the above-prepared powder coating material is applied to about 80 μm using an electrostatic spray coating machine for powder coating material, and 1
A coating film performance test plate was obtained by baking at 60 ° C. for 30 minutes to cure. The obtained cured film had a center line surface roughness of about 1 μm measured by a surface roughness meter (measuring device name: Surfcom, manufactured by Toyo Seimitsu Co., Ltd.), and showed excellent smoothness. In addition, it showed sufficient curability in an adhesion test by a goose eye test and a solvent resistance test by xylene rubbing. On the other hand, in the due panel type accelerated weather resistance test (manufactured by Suga Test Instruments Co., Ltd.), no change was observed in the coating film even after a test time of 1000 hours, and excellent weather resistance was exhibited. Furthermore, 30 of the powder coating
It showed excellent storage stability as a powder coating without blocking even after storage at 1 ° C for 1 month.

[0041]

Comparative Examples 1 and 2 Resin Production The resins obtained in Comparative Examples 1 and 2 were blended with the additives shown in Table 6 in the same amounts as in Example 1 and melt-kneaded, pulverized and classified. A powder coating was obtained. Next, each powder coating material was applied in the same manner as in Example 1 and baked at the curing temperature shown in Table 8 for 30 minutes to obtain a coating film performance test plate. Next, the coating properties were evaluated using the same items as in Example 1. As a result, in Comparative Example 1, the curability and weather resistance were excellent, but the smoothness was inferior, and in Comparative Example 2, the smoothness and curability were excellent, but the weather resistance was inferior.

[0043]

[Table 1]

[0044]

[Table 2]

In Tables 1 and 2, the subscripts mean the following. * 1: Resin solid content measured value (140 ° C, 30 minutes) * 2: Resin acid value measured value (potassium hydroxide / ethanol solution) * 3: GPC measured value (polystyrene conversion) * 4: Measured resin Tg by DSC ( JIS K 712
1) In Table 1 and Table 2, the unit of the numerical value indicating the blending amount of the synthetic solvent, the monomer mixture and the additional catalyst is part by weight.

[0046]

[Table 3]

[0047]

[Table 4]

[0048]

[Table 5]

[0049]

[Table 6]

In Tables 5 and 6, the subscripts mean the following. * 1: Blocked isocyanate curing agent (manufactured by Huls) * 2: UV absorber (manufactured by Ciba Geigy) * 3: Light stabilizer (manufactured by Sankyo) * 4: Leveling agent (manufactured by Mitsui Toatsu Kagaku) In Tables 5 and 6, the unit of the numerical value indicating the blending amount of the resin, the curing agent and the additive is part by weight.

[0051]

[Table 7]

[0052]

[Table 8]

From the coating film performance test results shown in Tables 7 and 8, Example 1 according to the present invention shows excellent smoothness, curability,
Weather resistance and storage stability can be achieved at the same time.
Particularly regarding the improvement of smoothness, the melt viscosity behavior shown in Table 3 can be obtained by the effect of copolymerizing a vinyl-based monomer having a specific polycyclic aliphatic hydrocarbon group contained in the vinyl-based copolymer resin. This is probably because the reduction was achieved. Regarding the weather resistance, it is considered that styrene is not contained in the vinyl-based copolymer resin. On the other hand, in Comparative Example 1,
Since vinyl copolymer resin contains styrene, the smoothness and curability are excellent, but the weather resistance is poor. In Comparative Example 2, since the vinyl-based copolymer resin is not copolymerized with a vinyl-based monomer having a polycyclic aliphatic hydrocarbon group, the curability and weather resistance are excellent, but the smoothness is poor.
Thus, since the resin composition for thermosetting powder coating material of the present invention can achieve excellent smoothness, curability, weather resistance and storage stability at the same time, various metals, plastics or building material surfaces It can be suitably used as a powder coating material.

[0054]

The resin composition for thermosetting powder coating material of the present invention can simultaneously achieve excellent smoothness, curability, weather resistance and storage stability of the coating film. Therefore, the resin composition for thermosetting powder coating material of the present invention is extremely useful in practice.

   ─────────────────────────────────────────────────── ─── Continued front page       (56) References JP-A-61-69877 (JP, A)                 JP-A-3-74479 (JP, A)                 JP-A-5-25424 (JP, A)

Claims (3)

(57) [Claims] 1. (A) 5 to 30% by weight of a repeating unit derived from a vinyl-based monomer represented by the following general formula (1): (In the formula, R ¹ is a hydrogen atom or a methyl group, and R ² is bicyclo [2.2.1] heptyl, 6-methylbicyclo [2.2.1] heptyl, 5,6-dimethylbicyclo [2. 2.1] heptyl, 1-methylbicyclo [2.
2.1] heptyl, 6-ethylbicyclo [2.2.1]
Heptyl, 1,7,7-trimethylbicyclo [2.2.
1] heptyl, bicyclo [4.4.0] decyl, tricyclo [3.3.1.1 ^{3, 7]} decyl, tricyclo [4.4.0.1 ^{2, 5]} undecyl, tetracyclo [4.4. 0.1 ^2,5 . 1 ^7,10 ] dodecyl, pentacyclo [6.6.1.1 ^3,6 . 1 ^{10, 13} . 0
^2,7 . 0 ^9,14] hexadecyl, hexacyclo [6.6.1.1 ^3,6. 1 ^{10, 13} . 0 ^2,7 . 0
^[9,14 ] heptadecyl, and a polycyclic aliphatic hydrocarbon group having 7 to 30 carbon atoms selected from those substituted with a substituent, and n represents an integer of 0 to 4. ) (B) 5 to 30% by weight of a repeating unit derived from a vinyl-based monomer having a glycidyl group in its chemical structure, and (C)
Become recurring units derived from other non-reactive vinyl monomer from 40 to 90 wt%, a range of the glass transition temperature of 50 to 100 ° C., a weight average molecular weight of 5 0
A resin composition for a thermosetting powder coating material, which comprises a vinyl-based copolymer resin in the range of 0-50000. 2. R ^{2 of the} general formula (1) is bicyclo [2.
2.1] heptyl, 1,7,7-trimethylbicyclo [2.2.1] heptyl, bicyclo [4.4.0] decyl, tricyclo [3.3.1.1 ^3,7 ] decyl, tricyclo [ 4.4.0.1 ^2,5 ] undecyl, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecyl,
And a resin composition for thermosetting powder coating composition according to claim 1, which is a polycyclic aliphatic hydrocarbon group having 7 to 30 carbon atoms selected from those in which substituents are substituted. 3. The resin composition for thermosetting powder coating composition according to claim 1, which contains an aliphatic dibasic acid compound as a curing agent.