JPS6040450B2 - thermosetting resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a heat treatment film that does not contain volatile components during curing and has excellent mechanical properties, rust prevention, weather resistance, and blocking resistance, and is particularly suitable for powder coatings. The present invention relates to a curable resin composition.

Powder coatings are less likely to cause a fire than traditional solvent-based coatings.
It is superior in terms of pollution problems, resource saving, labor saving, etc., and with the help of continuous progress in paint performance, painting equipment, and painting technology, it is now being used to paint home appliances and automobiles.
Initially, thermoplastic materials such as vinyl chloride resin and polyethylene resin were used as materials for powder coatings. However, recently, thermosetting resins such as epoxy resins, acrylic resins, and polyester resins, which have excellent workability and film properties, have become the main materials for powder coatings. Powder coatings made from epoxy resin have the greatest feature of rust prevention, but their greatest feature is film resistance, but their tear resistance is extremely poor, so they cannot be thinned down for outdoor use, and acrylic resins are Although the powder paint used as the material has excellent weather resistance, it has poor rust prevention and mechanical properties, and the properties of both epoxy and acrylic paints are inconsistent. On the other hand, powder coatings made from polyester resins that can be combined with various curing agents have good weather resistance, rust prevention, and mechanical properties, and have come to be widely used for both outdoor and indoor applications. Polyester resins are roughly divided into those whose functional groups are hydroxyl groups and those whose functional groups are carboxyl groups.

When the functional group of a polyester resin is a hydroxyl group, representative examples of curing agents combined with this resin include blocked polyisocyanates, N-acyl polylactam compounds, and amide/resins. When powder coatings are cured, blocking agents such as go-caprolactam and phenol, which make the functional groups of the curing agent inactive at room temperature, or condensates such as methanol, butanol, and water escape into the atmosphere. It has the disadvantage of being non-polluting, which is one of the features of body paints, and it causes foaming in the cured film, making it impossible to obtain a thick film with one coat. On the other hand, when the functional group of a polyester resin is a carboxyl group, curing agents that can be combined with this resin include polyoxazoline compounds and polyepoxy compounds. It can be said to be ideal in that it does not jump out. However, powder coatings that use polyoxazoline compounds as curing agents have the disadvantage that the polyoxazoline compounds tend to lose their activity due to the influence of moisture in the atmosphere, and do not function as a coating. In addition, bisphenol-type epoxy resin is generally used as a polyepoxy compound, and powder coatings using this bisphenol-type epoxy resin as a curing agent are made using epoxy resins with a small epoxy equivalent, such as Epicoat 8 (Shell Co., Ltd. product). A type with a reduced amount of epoxy resin added and an epoxy resin with a large epoxy equivalent, such as Epicoat 100L and Epicoat 1.
There is a type in which the amount of epoxy resin added is approximately the same as the amount of polyester resin using 007 (a product of Shell Co., Ltd.). Types using epoxy resins with low epoxy equivalents have good weather resistance, but because the epoxy resins are liquid, the blocking resistance of powder coatings is poor, and types using epoxy resins with high epoxy equivalents have good weather resistance. Since the epoxy resin is solid, the blocking resistance is not zero, but the film resistance is poor because the amount of the epoxy resin added is large. An ideal powder coating is free of volatile components during curing and has excellent film properties, particularly weather resistance, rust prevention, mechanical properties, and blocking resistance.

However, a thermosetting resin composition that satisfies these properties has not been found, and an immediate solution has been strongly desired. The present inventors focused on the combination of epoxy groups and carboxyl groups to create a curing system free of volatile components, and attempted to solve the problem by adding epoxy groups to polyester resin. In other words, conventional functional groups were limited to hydroxyl groups and carboxyl groups, which caused the above-mentioned problems.If it were possible to add epoxy groups to polyester resin, it would be possible to add aliphatic groups such as sebacic acid and dodecanedioic acid to the curing agent. Carboxylic acid, carboxyl group-containing polyester resin, carboxyl group-containing acrylic resin, etc. can be used, and it can be an ideal thermosetting resin composition for powder coatings. The present invention is directed to (1) an epoxy group-containing polyester resin obtained by reacting a hydroxyl group-containing polyester resin with an epoxy ester resin intermediate having both an epoxy group and an alkyl ester group obtained by reacting a polyepoxy compound and a terephthalic acid monoalkyl ester; [B--Regarding a thermosetting resin salmon composition whose main ingredient is a curing agent having two or more carboxyl groups.

The polyepoxy compound which is a component of the above-mentioned epoxy shester resin intermediate is a compound having two or more epoxy groups in the molecule. Bisphenol type epoxy resin obtained, hydrogenated bisphenol A type epoxy resin obtained by reaction of hydrogenated pisphenol such as hydrogenated bisphenol A with epichlorohydrin, terephthalic acid diglycidyl ester, isophthalic acid diglycidyl ester , polyglycidyl ester type epoxy resins such as hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, endomethylenetetrahydrophthalic acid diglycidyl ester, p-oxybenzoic acid glycidyl ester ether, etc. Glycidyl ester ether type epoxy resin, tris(2-epoxypropyl)
isocyanurate, acrylic acid glycidyl ester or methacrylic acid diglycidyl ester and other copolymerizable unsaturated monomers, preferably having a molecular weight of 3,000
Examples include acrylic resins having 0 to 30,000 oxirane groups.

Among these, bisphenol type epoxy resins such as Epicoat 823, Epicoat 1001 (product of Shell Co., Ltd.), water additives thereof, and tris-(2-epoxypropyl) isocyanurate are suitable from an industrial perspective. Specific examples of the terephthalic acid monoalkyl ester include terephthalic acid monomethyl ester, terephthalic acid monoethyl ester, and terephthalic acid monobutyl ester, and terephthalic acid mono/methyl ester is industrially suitable.

The ratio of the polyepoxy compound and the terephthalic acid monoalkyl ester must be such that the epoxy ester resin intermediate obtained by the reaction of the epoxy group of the polyepoxy compound and the carboxyl group of the terephthalic acid monoalkyl ester has at least one epoxy group. Must be. For this purpose, the terephthalic acid mono-lower alkyl ester/polyepoxy compound (equivalent ratio) is 1/n to n-1/n (where n is the average number of epoxy groups in one molecule of the polyepoxy compound). React in proportion. Although it may be outside this range, it is not preferable if a large amount of the polyepoxy compound for the reaction remains or if the number of epoxy groups in the obtained epoxy shester resin intermediate (1) is too small and the number of crosslinking points is too small. For the reaction of a polyepoxy compound and mono-lower alkyl terephthalate, both are placed in a reaction vessel, and amines such as ethanolamine, diethylamine, dibutylamine, piverizine, morpholine, diphenylamine, triethylamine, and pyridine, diethylamine hydrochloride,
Amine salts such as dimethylamine hydrochloride, quaternary ammonium salts such as dimethyldiphenylammonium chloride, dodecyldimethylbenzylammonium bromide, tetraethylammonium chloride, tetrahexylammonium chloride dotecyltrimethylammonium chloride triethylphenylammonium chloride, A catalyst such as salts of inorganic acids such as trisodium phosphate, sodium hydroxide, sodium sulfate, and sodium chlorate is added in an amount of 0.01 to 5% by weight, preferably 0.05 to 1% by weight based on the total amount of raw materials charged. In the presence or absence, 40~
It may be carried out at a temperature of 23,000 qC, preferably 60 to 150 qC.

There are no particular restrictions on the carboxylic acid that is a component of the hydroxyl group-containing polyester resin, and known raw materials can be used. Specific examples include malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecane 2 acid, dimer acid, phthalic acid, isophthalic acid, isophthalic acid dimethyl ester, terephthalic acid, terephthalic acid monomethyl ester, dibutyl terephthalate,
Dimethyl terephthalate, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid,
Methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endomethylenehexahydrophthalic acid,
Naphthalene dicarboxylic acid, diphenolic acid, trimellitic acid, pyromellitic acid, trimesic acid, cyclobentanedicarboxylic acid, 3,3',4,4'-penzophenonetetracarboxylic acid, 1,2,3,4- Butanetetracarboxylic acid, 2,2-pis(4-carboxyphenyl)propane, dimidocarboxylic acid obtained from trimellitic anhydride and 44,4'-diaminophenylmethane, tris-(8-carboxyethyl) ) Isocyanurate, isocyanurate ring-containing polyimidopolycarboxylic acid obtained from isocyanurate ring-containing polyisocyanurate and trimellitic anhydride, such as tolylene diisocyanate, xylene diisocyanate or isophorone diisocyanate tertiary reactant and trimellitic acid One or more types of isocyanurate ring-containing polyimide polycarboxylic acids obtained from acid anhydrides are used. Alcohols include ethylene glycol, diethylene glycol,
Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol isobentyl glycol, hydrogenated bisphenol A, 1,3-butanediol, 1,4-butanediol, ,1,6-hexanediol, neobentyl glycol , xylylene glycol, 1,4-cyclohexanedimethanol, glycerin, trimethylolethane, trimethylolpropane, bis(8-hydroxyethyl)terephthalate, tris(8-hydroxyethyl)isocyanurate, 2
, 2,4-trimethylbentane-1,3-diol.

Examples of oxycarboxylic acids include p-oxybenzoic acid, vanillic acid, p-hydroxymethylbenzoic acid, 5-hydroxylisophthalic acid, dimethylolpropionic acid, malic acid, and tartaric acid. These raw materials can be used as their ester-forming derivatives. These raw materials are used in proportions such that the amount of hydroxyl group equivalents is in excess.

The acid value of the obtained hydroxyl group-containing polyester resin is 20 (3 KOH/night) or less, preferably 10 (KOH
o/d) or less, and the hydroxyl value is preferably 20 to 20, preferably 30 to 150. Acid value is 20
If it exceeds (o/t of KOH), when a polyester resin intermediate is added, the number of epoxy groups will be consumed by reaction with carboxyl groups, and the epoxy content of the epoxy group-containing polyester resin will decrease, which is not preferable. If the hydroxyl number is less than 2 degrees, the amount of the epoxy shester resin intermediate (■) to be reacted will be small, resulting in fewer crosslinking points in the epoxy group-containing polyester resin that is finally obtained. Preferably, the tee is lowered. The hydroxyl group-containing polyester resin is produced, for example, as follows.

The raw materials are charged into a reaction vessel, and the reaction is started at a temperature of 160° to 190° while blowing an inert gas such as nitrogen gas. If it forms, it is continuously removed from the reaction system. After several hours from the start of the reaction, the temperature was increased to 200 to 25 pm.
The reaction is accelerated by increasing the temperature to obtain a polyester resin containing hydroxyl groups. To further accelerate the reaction, if the reaction is an esterification reaction, a metal organic compound such as dibutyltin dilaurate, dibutyltin dioctate, dibutyltin oxide, or a metal alkoxide catalyst such as tetrabutyl titanate is added to all raw materials. Use 0.1 to 1% by mass based on the amount charged, and when the reaction is a transesterification reaction, metal oxides such as zinc oxide and antimony oxide, zinc acetate, calcium acetate, lead acetate, and magnesium acetate. It is effective to use a metal acetate or metal alkoxide catalyst such as 0.005 to 0.05% by mass based on the total amount of raw materials charged. To produce an epoxy shester resin by reacting the above epoxy shester resin intermediate with a hydroxyl group-containing polyester resin, both are mixed in the presence of a transesterification catalyst such as zinc oxide, zinc acetate, calcium acetate, or tetrabutyl titanate, preferably with nitrogen gas. The reaction is carried out in an atmosphere of an inert gas such as, at a temperature of 180 to 230°C while continuously removing the lower alcohol produced.

The epoxy group-containing polyester resin obtained in this way has a softening point of 50 to 20 when used as a powder coating.
It is adjusted to 0 qo, preferably 70 to 150 qo.

Therefore, it is preferable that the amount of aromatic carboxylic acid (including aromatic oxycarboxylic acid when aromatic oxycarboxylic acid is used) is at least 70 mol % based on the total amount of rubocic acid. If the softening point of the resulting resin is lower than 50°C, a powder coating using the same will have good blocking resistance. On the other hand, if it is too high, it is not preferable, and if it exceeds 200 mm, the smoothness of the powder coating using it will decrease. Further, the ratio of the epoxy shester intermediate (A') to the hydroxyl group-containing polyester resin (B) is (A)/(8) from 20 to 80.
A range of 80/20 (weight ratio) is desirable, especially,
(A')/(B) is 30/70 to 70/30 (weight ratio)
If (A)/(B') is less than 20/80, the number of epoxy groups will be small and the crosslinking density will not increase, and (A')/
When (B') exceeds 80/20, flexibility decreases.

The curing agent for component 'B) may be any curing agent as long as it has two or more carboxyl groups in one molecule.

These polycarboxylic acids include aromatic polycarboxylic acids represented by phthalic acid, tetrahydrophthalic acid, trimellitic acid, pyromellitic acid, etc., and their acid anhydrides such as adipic acid, sebacic acid, dodecashinic acid, 1,2, 3,4
Examples include aliphatic polycarboxylic acids such as monobutanetetracarboxylic acid, and polyester resins and Acrylic resins containing carboxyl groups. When mechanical properties are important, aliphatic polycarboxylic acids, particularly dodecanedioic acid, 1,2,3,4-butanetetracarboxylic acid, or carboxyl group-containing polyester resins are preferred.

The carboxyl group-containing polyester resin preferably has a number average molecular weight of 1,000 to 5,000 and an acid value of 20 to 200.
is preferably 30 to 100 in terms of various properties (mechanical properties, blocking resistance, leveling properties, etc.). The same raw materials as those for the hydroxyl group-containing polyester described above can be used. Carboxyl group-containing acrylic resins that require stain resistance are preferred.

Acrylic resin has a number average molecular weight of 3,000 and is obtained by reacting (meth)acrylic acid with a monomer that can be copolymerized with it.
~30,000 and an acid value of 20 to 200 are preferable in terms of properties. Monomers copolymerizable with acrylic acid or methacrylic acid include acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; similar methacrylic acid alkyl esters; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2
-Hide. Hydroxyl alkyl acrylates such as xyethyl acrylate, similar hydroxyalkyl methacrylates, styrene, vinyltoluene, styrenic monomers such as p- to rt-butylstyrene and Q-methylstyrene, unsaturated substances such as acrylonitrile and methacrylonitrile. Nitrile compounds, unsaturated amide compounds of acrylic acid or methacrylic acid such as acrylic acid amide, methacrylic acid amide, glycidyl methacrylate, glycidyl acrylate,
These include vinyl esters such as vinyl acetate, vinyl halides such as vinyl chloride, and these may be used alone or in combination. Among these, acrylic acid alkyl ester, methacrylic acid alkyl ester and styrenic monomer are preferred. Further, the monomer having a functional group reactive with a carboxyl group is preferably used in an amount of 5% by weight or less based on the total monomers used. Of course, the characteristics can also be finely adjusted by mixing these curing agents. The ratio of the epoxy shester resin, which is the wind component, and the curing agent, which is the component B, is preferably BI=20/80 to 95/5 (weight ratio). In particular, leg/'B' is preferably 30/70 to 90/10 (weight ratio). In particular, ■/legs are 30/70-90/
10 (weight ratio) is preferable. If it exceeds 95/5, the crosslinking density will be insufficient and the properties will not be achieved, and if it is less than 20/8, the carboxyl group of the reaction will remain, resulting in a decrease in water resistance, etc., which is not preferable.

The resin composition according to the present invention may contain known colorants, pigments, fillers, fluidity regulators, and hardening accelerators as appropriate. Synthesis Example 1 1 Manufacturing components of eboxy acid ester resin intermediate
Charge amount (mass) Epicote 828
760 Terephthalic acid monomethyl ester 360 Put the above ingredients into a reaction container,
The reaction was carried out at 200° C. for 30 minutes to obtain a polyester resin intermediate containing an epoxyester group.

ii Production components of hydroxyl group-containing polyester resin Charge amount (mass) Terephthadimethylester 677 Neobentyl glycol 380 1,6-Hexanediol 121,4-Cyclohexane dimethanol 15 Trimethylolethane
13 Zinc acetate (catalyst) 1
The above components were placed in a reaction container and kept at 170°C for 3 hours while removing by-product methanol from the reaction system.
The reaction was advanced by raising the temperature to 22,000 over a period of time to obtain a hydroxyl group-containing polyester resin with a hydroxyl value of 74.

01 Manufacturing component of epoxy shester resin Charge amount (mass) Polyester resin intermediate 1120 Hydroxyl group-containing polyester resin 1500 Tetrabutyl titanate 2 Charge the above components into a reaction vessel 220
The transesterification reaction was carried out at 0.00°C to obtain an epoxy shester resin having an epoxy equivalent of 127 and a softening point of 114°C.

Example 1 Paint composition Composition ratio (mass) Epoxy group-containing polyester resin resin intermediate obtained in Synthesis Example 1
90.0 Dodecanedioic acid
10.0 Motaflow (Monsanto company product name acrylic polymer) 0.7 Penzoin
0.5 Rutile type titanium white 45.02-Methylimidazole 0.1 After drain-blending the above composition with a mixer at 1,00 pm for 1 minute,
Melt lacrimation was carried out using a Co-kneader PR-46 manufactured by Busu Co., Ltd.

After rapidly cooling the tear paste, it was crushed and classified to obtain a powder coating of 150 mesh or less. This powder coating was electrostatically sprayed onto a zinc phosphate-treated steel plate to a thickness of 60 ym, and a test piece was obtained by applying two powders at 180°C.

Synthesis Example 2 1 Manufacturing components of epoxy acid ester resin intermediate
Charge amount (mass) Tris(2-epoxypropyl) isocyanurate 594 Terephthalic acid monomethyl ester 360 Place the above components in a reaction container and react at 210°C for 4 minutes to create a polyester resin intermediate that uses both epoxy and methyl ester groups. I got it.

ii Production components of hydroxyl group-containing polyester resin Interpolation amount (mass) Terephthadimethyl ester Neobentyl glycol 4311,6-hexanediol 8 Trimethylolpropaso
13 Zinc acetate (catalyst) 1
111 Manufacturing components of epoxy shester resin
Charge amount (mass) Polyester resin intermediate
954 Hydroxyl group-containing polyester resin 800 Tetrabutyl titanate 2 The above components were charged into a reaction vessel and a transesterification reaction was carried out at 220°C to obtain an epoxy group-containing polyester resin having an epoxy equivalent of 469 and a softening point of 1070.

Synthesis Example 3 Manufacture of carboxyl group-containing polyester resin Components Charged amount (mass) Terephthal
1161 ethylene glycol
267 neoventyl glycol
Spot 5 ■ 1,6-hexanediol
24 trimethylolpropane
56 diptyltin oxide (catalyst) 10@{Tsuru Tsuru Chirui Shinre (Emblem 320) The above ■ ingredients were placed in a reaction container and the reaction was carried out at 180°C for 5 hours and then at 220°C for a skin time, then the @ ingredients were added. addition 2
The acid value was 49 (KOH o/
(2) A carboxyl group-containing polyester resin having a softening point of 1190 was obtained.

Example 2 Paint composition Composition ratio (mass) Epoxy group-containing polyester resin obtained in Synthesis Example 2
30.0 Carboxyl group-containing polyester resin obtained in Synthesis Example 3 70.0 Modaf.

- (Monsanto product name, acrylic polymer)
0.7 pensoin
0.5 rutile type titanium white
45.02-Methylimidazole
0.1 A powder coating was obtained in the same manner as in Example 1 with the above composition.

A test piece was prepared in the same manner as in Example 1 using this powder coating.

Synthesis Example 4 i Manufacture of hydroxyl group-containing polyester resin Components Charged amount (mass) Terephthadimethyl ester 655 neobentyl glycol 4011,6-hexanediol
121,4-Cyclohexane dimethanol 15 Trimethylolethane 1
2 Zinc acetate (catalyst) 1 The above components were placed in a reaction vessel and the reaction proceeded under the same conditions as in Example 1 to obtain a polyester resin with a hydroxyl value of 110.

u Production mechanical components of epoxy ester resin Charge amount (mass) Epoxy ester resin intermediate obtained in Synthesis Example 1
Epoxy shester resin intermediate in 560 Synthesis Example 2
477 Hydroxyl group-containing polyester resin obtained in Synthesis Example 4
1000 Tetrabutyl titanate 2 The above components were charged into a reaction vessel, and transesterification reaction was carried out using a Matsubio to obtain an epoxy-containing ester resin having an epoxy equivalent of 679 and a softening point of 111°C.

Synthesis Example 5 Manufacturing component of carboxyl group-containing acrylic resin Charge amount (mass) Styrene
133 Butyl acrylate 117 Methyl methacrylate
50 methacrylic acid
Spotted azobisisobutyronitrile (polymerization initiator) 8 Ethyl cellosolve (solvent) 1,600 Of the above ingredients, ethyl cellosolve was charged into a reaction vessel, and 12,000 and the remaining components were added dropwise over 2 hours.

Then, the reaction temperature was raised to 130°C and kept at this temperature for 7 hours.
After dropping the copolymerization solution into a large amount of water to precipitate the copolymerization solution, it was dried for 1 hour under reduced pressure of 60q○ (less than 5 days) to obtain a carboxyl group with an acid value of 78 (KOH female/night). A containing acrylic resin was obtained. Example 3 components
Composition ratio (mass) Epoxy group-containing polyester resin obtained in Synthesis Example 4 50.0 Carboxyl group-containing acrylic resin obtained in Synthesis Example 5
50.0modaf.

1 (Monsanto company product name acrylic polymer)
0.7 penzoin
0.5 rutile type titanium white
45.02-Methylimidazole
0.1 A powder coating material was obtained in the same manner as in Example 1 with the above composition.

A test piece was prepared in the same manner as in Example 1 using this powder coating.

Example 4 Paint composition Charge amount (mass) Epoxy group-containing polyester resin obtained in Synthesis Example 1 95.01,
2,3,4-butanetetracarboxylic acid
5.0 moda flow
0.7 penzoin
0.5 Hetyl titanium white
45.02-Methylimidazole
0.1 A powder coating was obtained in the same manner as in Example 1 with the above composition.

A test piece was prepared in the same manner as in Example 1 using this powder coating.

Synthesis Example 6 Manufacture of carboxyl group polyester resin Components Charged amount (mass) @ trimellitic anhydride 64 The above component
The temperature was raised to 20°C to proceed with the reaction.

The reaction temperature was lowered to 180 oo, and the @component was added and reacted for 2 hours to obtain a carboxyl group-containing polyester resin having an acid value of 40 (KOHm9/night) and a softening point of 120°C. Comparative example
1 Paint composition Composition ratio (mass) Carboxyl group-containing polyester resin obtained in Synthesis Example 6 88.0 Epicoat 828 12.0 Motaflow (Monsanto Co., Ltd. trade name acrylic polymer)
0.7 penzoin
0.5 rutile type titanium white
45.02-Methylimidazole
0.1 A powder coating similar to that of Example 1 was obtained using the above composition example.

A test piece was obtained in the same manner as in Example 1 using this powder coating.

Synthesis Example 7 Manufacture of carboxyl group polyester resin Constituent components Charge amount (mass) The above component
After proceeding with the skin time reaction at
A carboxyl group-containing polyester resin was obtained.

Comparative example 2 Paint composition Composition ratio (mass) Carboxyl group-containing polyester resin obtained in Synthesis Example 7 50.0 Epicoat 1004 50.0 Motaflow 0◆7
Penzoin 0.5
Rutile type titanium white 45.02-Methylimidazole 0.1 A powder coating similar to Example 1 was obtained using the above composition example.

A test piece was prepared in the same manner as in Example 1 using this powder coating.

Table 1 shows the results of tests using the powder coatings and test pieces obtained in Examples 1 to 4 and Comparative Examples 1 to 2.

Table 1 Test results {1' 60 degree mirror reflectance '21 Load 500 kg and 1 kg {3} Salt soubre test: (35oo, 5% NaC
Evening) After 50m hours, the sellotape was <separation.

■ Sunshine User Meter Test: Gloss retention rate after 30 feeding hours.

(5) Magic ink (black) 250○, degree of contamination after 24 hours (xylene/butanol wiping) Evaluation criteria○: No trace at all.

△: There are some traces.

×: There are traces.

(6) Condition evaluation criteria after leaving the powder coating at 25q○ for 7 days: ○: The powder coating flows with the slightest impact.

△: A state in which the powder paint flows due to a light impact, but small souls can be seen in the paint.

×: The whole state is a lump.

As is clear from the above, the thermosetting resin composition of the present invention is suitable for powder coatings and has extremely excellent mechanical properties (Erichsen, Impact), rust prevention, weather resistance, and blocking resistance. It is something.

The thermosetting resin composition according to the present invention is applied to coating home appliances, automobile bodies, building materials, and the like.

Claims (1)

[Scope of Claims] 1 (A) An epoxy ester resin intermediate having both an epoxy group and an alkyl ester group obtained by reacting a polyepoxy compound having at least two epoxy groups with a terephthalic acid monoalkyl ester, and a hydroxyl group A thermosetting resin composition comprising as main ingredients an epoxy group-containing polyester resin obtained by reacting a containing polyester resin, and (B) a curing agent having two or more carboxyl groups. 2 The epoxy-containing polyester resin contains at least 7 aromatic carboxylic acids (including aromatic oxycarboxylic acids when aromatic oxycarboxylic acids are used) in the total carboxylic acid components.
The thermosetting resin composition according to claim 1, which is an epoxy ester group-containing polyester resin containing 0 mol% and having a softening point of 50 to 200°C. 3 The polyepoxy compound is bisphenol type epoxy resin, hydrogenated bisphenol type epoxy resin, tris(
Claim 1, which is at least one compound selected from the group of 2-epoxypropyl) isocyanurates.
The thermosetting resin composition according to item 1 or 2. 4 Claims 1 and 2 in which the terephthalic acid monoalkyl ester is terephthalic acid monoethyl ester
The thermosetting resin composition according to item 1 or 3. 5. Claims 1 and 2, wherein the curing agent having a carboxyl group is at least one compound selected from the group of aliphatic carboxylic acids, carboxyl group-containing polyester resins, and carboxyl group-containing acrylic resins. , the thermosetting resin composition according to item 3 or 4. 6 Claims 1, 2, 3, 3 or 4 which are 1,2,3,4-butanetetracarboxylic acid and/or dodecanedioic acid as a curing agent having a carboxyl group
The thermosetting resin composition described in .