JPH0465478A - High-solid coating composition - Google Patents

Abstract

PURPOSE:To obtain the title composition consisting essentially of a resin mixture of a silicon compound in which hydroxyl groups are chemically bonded to a silicon atom and hydroxyl group-containing resin and curing agent having a functional group capable of reacting with the hydroxyl group and having excellent acid resistance and weather resistance. CONSTITUTION:The aimed high-solid coating composition consisting essentially of a resin mixture of (A) 5-50 wt.% silicon compound containing >= 2 hydroxyl groups chemically bonded to a silicon atom in one molecule and having 200-4,000 weight-average molecular weight and 100-600 hydroxyl group equivalent, (B) 10-80 wt.% hydroxyl-containing resin such as acrylic resin or polyester resin and (C) 10-50 wt.% curing agent such as an alkyletherified melamine resin or isocyanate compound having a functional group capable of reacting with a hydroxyl group.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a novel high solids coating composition, more specifically, a coating composition containing a silicone compound in which a hydroxyl group is chemically bonded to a silicon atom and having excellent acid resistance and weather resistance. The present invention relates to a high solids coating composition.

[Conventional technology] In recent years, the paint industry has been facing problems such as environmental pollution.
The need for high-solid paints is increasing with the aim of reducing organic solvent emissions, and in terms of paint film performance, due to the problem of paint film deterioration due to acid rain, etc., we are developing paints with excellent weather resistance and acid resistance. There is an urgent need to develop new paints.

Generally, in order to convert a paint into a bindrid, a low molecular weight base and a curing agent are used, and attempts have also been made to use a reactive diluent in combination. Usually, a relatively low molecular weight polyol is used as a base material, a low molecular weight alkyl etherified melamine resin or incyanate compound is used as a curing agent, and a low molecular weight polyester compound is used as a reactive diluent. Often used.

However, because conventional high-solid paints use low-molecular-weight bases and curing agents, there are limits to the acid resistance of the paint film, and low-molecular-weight polyesters are used as reactive diluents. Even when a compound is used, there is a drawback that the weather resistance and acid resistance of the coating film are insufficient.

On the other hand, a coating using a reaction product of a silicone compound in which a methoxy group is chemically bonded to a silicon atom and a diol compound is known (Japanese Patent Application Laid-Open No. 168770/1982).

However, although this paint has relatively good weather resistance, it has the drawback of poor acid resistance.

[Problems to be Solved by the Invention] Under these circumstances, the present invention was made with the object of providing a high solids coating composition with excellent weather resistance and acid resistance.

[Means for Solving the Problem] As a result of intensive research to develop a high solids coating composition with excellent weather resistance and acid resistance, the present inventors found that a specific silicone compound improves the acid resistance and acid resistance of the coating film. A composition whose main component is a resin mixture containing this material, a hydroxyl group-containing resin, and a curing agent having a specific functional group in predetermined proportions is suitable for dramatically improving weather resistance. The present invention was completed based on this finding.

That is, the present invention provides (A) a compound having a weight average molecular weight of 2 or more having two or more hydroxyl groups per molecule chemically bonded to a silicon atom.
00 to 4,000 and 5 to 50% by weight of a silicone compound having a hydroxyl equivalent of 100 to 600, (B) 10 to 80% by weight of a hydroxyl group-containing resin, and (C) 10 to 10% of a curing agent having a functional group capable of reacting with a hydroxyl group. The object of the present invention is to provide a high solids coating composition comprising as a main component a resin mixture of 50% by weight.

The present invention will be explained in detail below.

The silicone compound as component (A) in the composition of the present invention has two or more hydroxyl groups per molecule chemically bonded to a silicon atom, and has a weight average molecular weight of 200 to 4.
,000, and the hydroxyl equivalent is 100 to 60
A value in the range 0 is used. If the number of hydroxyl groups chemically bonded to a silicon atom is less than two per molecule, the crosslinking density of the resulting coating film will be low, and the mechanical properties, particularly the impact resistance, will be reduced. Further, if the weight average molecular weight is less than 200, the weather resistance of the coating film will be insufficient, and if it exceeds 4.000, it will be difficult to increase the solid content required for the vine lid paint. Furthermore, if the hydroxyl equivalent is less than 100, the mechanical properties of the coating film, especially the flexibility (e.g. bending resistance), will be poor;
If it exceeds 600, the weather resistance of the coating film tends to decrease.

Examples of the silicone compound used as the component (A) include KR-211°KR-212, KR-21
4, KR-216 [both manufactured by Shin-Etsu Chemical Co., Ltd. and commercially available under the trade name Konato.

In the composition of the present invention, examples of the hydroxyl group-containing resin used as component (B) include acrylic resins, polyester resins, alkyd resins, epoxy resins, polyurethane resins, fluororesins, and silicone resins.

One type of these resins may be used, or two or more types may be used in combination within the range of compatibility.

Further, in the composition of the present invention, examples of the curing agent having a functional group capable of reacting with a hydroxyl group used as component (C) include alkyl etherified melamine resins and incyanate compounds. Among these, the alkyl etherified melamine resin is preferably one in which the number of carbon atoms in the alkyl group is 8 or less and the number average molecular weight is 1,000 or less. If the number of carbon atoms in the alkyl group exceeds 8, the water resistance of the resulting coating film may be lowered, and if the number average molecular weight exceeds 1.000, it becomes difficult to form a paint with a high degree of solidity, which is not preferable.

As such alkyl etherified melamine resin,
For example, as a commercial product, Cynor 300. ．． Cymel 30
1, Cymel 303, Cymel 350, Cymel 111
6. Cymel 1130, Cymel 1168 [both manufactured by American Cyanamid Company, product name], Nikaratsuku M
W-30, Nikaratsuku MW-22A, Nikaratsuku MX-
40, Nikaratsuku MX-45 [all three-phase chemicals (
Co., Ltd., product name], Regimin 730, Regimin 731,
Examples include Regimin 735, Regimin 745, Regimin 746, Regimin 747, Regimin 753, Regimin 755, Regimin 764 [all manufactured by Monsanto, trade name], Kneepan 120 [manufactured by Mitsui Toatsu Co., Ltd., trade name], etc. .

In this case, aromatic or aliphatic sulfonic acid compounds can be used as the curing catalyst, but aliphatic sulfonic acid compounds are preferable in terms of the storage stability of the paint, the appearance of the coating film, and the like.

In addition, as an incyanate compound, 2
Aromatic or aliphatic compounds having more than one isocyanate group, such as 2,4-toIJ diisocyanate, 4
．． 4'-diphenylmethane diisocyanate, 1.6-
Hexamethylene diisocyanate, cyclohexane-1
, 4-diisocyanate and other polyisocyanate compounds, and polyisocyanate compounds such as alcohols such as ethanol and hexanol, compounds with phenolic hydroxyl groups such as phenol and cresol, oximes such as acetoxime and methyl ethyl ketoxime, and ε-caprolactam. , blocked isocyanate compounds blocked with blocking agents such as lactams such as γ-caprolactam.

One type of curing agent containing a functional group capable of reacting with these hydroxyl groups may be used, or two or more types may be used in combination.

In the composition of the present invention, the content ratios of the silicone compound as the component (A), the hydroxyl group-containing resin as the component (B), and the curing agent as the component (C) are as follows: component (A), component (B), and component (C). Component (A) is 5 to 50% by weight based on the total weight of (
Component B) is 10 to 80% by weight, component (C) is 10 to 50% by weight.
It is necessary that the amount be within the range of % by weight.

If the content of component (A) is less than 5% by weight, the effect of improving the acid resistance and weather resistance of the resulting coating film will not be sufficiently exhibited, and if it exceeds 50% by weight, the mechanical properties of the resulting coating film, especially There is a tendency for flexibility to decrease. Furthermore, if the content of component (B) is less than 10% by weight, the resulting coating film will have poor mechanical properties, especially flexibility, and if it exceeds 80% by weight, it will be difficult to achieve the high solid content required for high solid paints. becomes.

On the other hand, if the content of component (C) is less than 10% by weight, the resulting coating film will not have sufficient hardness, and if it exceeds 50% by weight, the mechanical properties, especially the flexibility, of the resulting coating film will tend to decrease. It will be done.

The high solids coating composition of the present invention can be prepared by dispersing each of the above-mentioned components using a dispersion device used in ordinary coating production, such as a ball mill.
It can be prepared by mixing using a sand mill, attritor, etc. using a conventional addition method. At this time, in addition to coloring agents such as pigments, dyes, glass flakes, and aluminum flakes, additives commonly used in paints, such as pigment dispersants, viscosity modifiers, leveling agents,
A curing catalyst, anti-gelling agent, ultraviolet absorber, radical scavenger, etc. can also be added.

The paint thus obtained can be applied to the desired substrate, such as metals and other inorganic materials, plastics and other materials, by conventional coating methods such as air spray coating, airless spray coating, electrostatic coating, and dipping. It is applied to organic materials using a system such as 1 coat 1 bake, 2 coats 2 bake, 2 coats 1 bake, 3 coats 3 bake, 3 coats 2 beta, etc., and is usually dried at a temperature of 60 to 180 degrees Celsius for about 20 to 60 minutes. As a result, an excellent coating film can be obtained.

[Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, the coating film performance was evaluated as follows.

(1) Pencil hardness Using a pencil specified in JIS S-6006, scratch the coating film with the angle between the test piece and the pencil at 45 degrees,
The hardness symbol that is one level lower than the one scratched twice or more after being scratched five times is taken as the evaluation value.

(2) 60 degree specular gloss Based on JIS K-54006, 760 degree specular gloss.

(3) QUU test QUV [manufactured by Q-Pane 1, trade name:] was used to conduct an accelerated weathering test, and the 60 degree specular gloss and coating film cracking occurrence time after 2000 hours (cracking due to coating film deterioration, The time at which cracks were observed by visual observation was determined.

(4) Apply 0.2rnn of acid-resistant 0.4N HCfi solution on the coating film, hold it at a temperature of 85℃ for 15 minutes, and then visually observe the condition of the spot marks immediately after washing with tap water. Evaluation was made according to the criteria.

Good: There is no change in color or gloss of the paint film, and there is no blistering. Defects such as these are not recognized at all.

Slightly poor: Changes in color, gloss, or blistering in the paint film There are some defects such as:

Bad: Changes in color, gloss, or blistering in the paint film Defects such as these are noticeable.

(5) Flexibility It was evaluated according to the JIS K-54008, 1 bending resistance test method according to the following criteria.

Good: No cracking or peeling of the paint film is observed.

Defect: Cracks, peeling, etc. are observed in the paint film.

Production Examples 1 to 3 Production of Acrylic Resin Solutions 61.8 parts by weight of methyl amyl ketone was charged into a four-bottle flask equipped with a reflux condenser, a stirrer, a dropping funnel, and a thermometer, and the temperature was raised to 150°C without stirring. It was heated up to. Then the first
100 parts by weight of a mixture of the monomer components and polymerization initiator shown in the table was added dropwise at a constant addition rate over 2 hours at a temperature of 150°C. After the dropwise addition was completed, the reaction was terminated by maintaining the temperature at 150° C. for another 2 hours to obtain acrylic resin solutions 1 having the characteristic values shown in Table 1.

(Leaving space below) Production Example 4 Production of crosslinked polymer fine particles (a) Production of aqueous dispersion of crosslinked polymer fine particles Surface active diluted aqueous solution Deionized water 380.0 parts by weight Syntrex L100'' 7.0 parts by weight Polymerization initiator Aqueous solution-1 Deionized water 1000 parts by weight Sodium persulfate 0.3 parts by weight Vinyl monomer mixture 2-hydroxyethyl acrylate 2.0 parts by weight 1.6-hexanethiol dimethacrylate 40.0 parts by weight Styrene 10. 0 parts by weight n-butyl methacrylate 48.0 parts by weight Polymerization initiation aqueous solution -2 Deionized water 10.0 parts by weight Sodium persulfate 0.3 parts by weight Note 1) Syntrex L100 [manufactured by Nippon Oil & Fats Corporation, sodium lauryl sulfate] Product name, 100% active ingredients
] A surfactant aqueous solution was charged into a flask equipped with a stirring device, a reflux condenser, a dropping funnel (two), a nitrogen introduction tube, and a thermometer, and the temperature was raised to 80°C under a nitrogen stream to form a polymerization initiator aqueous solution.
1 was added. After raising the temperature to 80°C again, the vinyl monomer mixture was added dropwise over 3 hours while keeping the mixture in the flask at 80±2°C. During the dropwise addition of the monomer mixture,
One hour after the start of the dropwise addition, the polymerization initiator aqueous solution-2 was added dropwise over a period of 2 hours. After finishing dropping the vinyl monomer mixture and polymerization initiator aqueous solution-2, polymerization was further carried out at 80°C for 2 hours to obtain an aqueous dispersion AI of crosslinked polymer fine particles having the characteristic values shown in Table 2. Ta.

(b) Production of non-aqueous dispersion of crosslinked polymer fine particles 500 parts by weight of the aqueous dispersion AI of crosslinked polymer fine particles obtained in (a), 200 parts by weight of methyl isobutyl ketone and 22.7 parts by weight of 3N NaOH aqueous solution The mixture was heated to 85°C, and a hydrolysis reaction was carried out at 85±2°C for 3 hours. Next, the temperature was lowered to 80°C, and 3N hydrochloric acid aqueous solution was added to 22.7°C.
After adding parts by weight and neutralizing, 18.5 parts by weight of the acrylic resin solution ■ obtained in Production Example 3 was added as a particle dispersion stabilizing resin, and after stirring for 10 minutes, a 20% by weight aqueous solution of triethylamine acetate (after After adding 25 parts by weight of the mixture, stirring was immediately stopped and the mixture was allowed to stand. An organic layer in which cross-linked polymer fine particles were dispersed was separated into an upper layer and an aqueous layer was separated from the lower part, so the lower aqueous layer was removed.

200 parts by weight of deionized water was added to the remaining organic layer in which crosslinked polymer fine particles were dispersed, and the temperature was raised to 70°C while stirring.
20% by weight of triethylamine acetate when reaching C
12.5 parts by weight of the aqueous solution was added, and stirring was immediately stopped and the mixture was allowed to stand still. Once again, the organic layer in which the crosslinked polymer fine particles were dispersed was separated into two layers: the upper layer was the aqueous layer, and the lower aqueous layer was removed. In the remaining organic layer, 1.7% by weight of water remained as determined by a Karl Fischer moisture meter.

Next, the temperature of the organic layer was cooled to 50°C, and 70 parts by weight of methyl orthoformate was added dropwise from the dropping funnel over 30 minutes, followed by a reaction at 50°C for 30 minutes to decompose the remaining water. After that, 200 parts by weight of xylene was added, a new Dean-Stark trap was installed between the reflux condenser and the flask, the upper part of the reflux condenser was connected to the aspirator, and the inside of the flask was brought to a reduced pressure state while heating and stirring. 100mm
H9, the non-volatile content of the dispersion under conditions of 80 ± 10°C is 40
A non-aqueous dispersion A2 of crosslinked polymer fine particles was obtained by distilling off the solvent until the amount was reduced to % by weight. Table 2 shows the characteristic values of the obtained non-aqueous dispersion.

(Production method of 20% by weight aqueous solution of triethylamine acetate salt) 7.5 parts by weight of acetic acid is dissolved in 80 parts by weight of deionized water, and 12.5 parts by weight of triethylamine is added thereto over 30 minutes while stirring at room temperature. Prepared by

(Margin below) Table 2 Notes 1) JIS K-54008, 2 Based on heating residue 2
) 60 rpm using a Brookfield viscometer.

Measured under the condition of 20℃ 3) Measured using Nicomp, model 370j (product name) manufactured by Pacific Scientific 4) Measured using KF-O5 type moisture meter manufactured by Mitsubishi Chemical Corporation Example 1 (1) 111.2 parts by weight of the acrylic resin solution obtained in Preparation/Production Example 3 of base coat paint (111.2 parts by weight) of methylated melamine resin [heating residue 98% by weight, Cymel 303, manufactured by American Cyanamid, trade name] 30. 6 parts by weight Non-aqueous dispersion A2 of crosslinked polymer fine particles obtained in Production Example 4 83.5 parts by weight Aluminum pigment [heating residue 65% by weight, aluminum paste 716ON, manufactured by Toyo Aluminum Co., Ltd., trade name ] 15.4 parts by weight Sulfonic acid catalyst (described later) 1.6 parts by weight Ultraviolet absorber [Chikubin 9001 manufactured by Ciba Geigy, trade name j
1010 parts by weight of a 10% by weight xylene solution and 1.01 parts by weight of n-butyl alcohol.
A base coat paint was prepared by diluting the base coat with a coating viscosity (Ford Cup No. 4, 14 seconds at 20° C.) with chloroalcohol=s/F/2 weight ratio.

(Production method of sulfonic acid catalyst) In a three-necked flask equipped with a stirrer, add C+aHs, 5
356.0 parts by weight of O3Na and 86 parts by weight of n-butyl alcohol
Add 1.4 parts by weight of the mixture and add 3 parts by weight while stirring at room temperature.
98.1 parts by weight of 7.2% by weight hydrochloric acid was added to remove sodium. At this time, the desodification reaction proceeded immediately after the addition of hydrochloric acid, and 58.5 parts by weight of NaCe was precipitated.

The precipitated NaCl2 was filtered off by suction filtration;
Add 79.0 parts by weight of pyridine to the filtrate to obtain an active ingredient concentration (aliphatic sulfonic acid) blocked with equimolar pyridine.
A 25% by weight aliphatic sulfonic acid compound solution was obtained.

(2) Preparation of paint for clear coat - silicone compound [heating residue 70% by weight, molecule 13,
000, hydroxyl equivalent of active ingredient 343, KR-214, manufactured by Shin-Etsu Chemical Co., Ltd., trade name 11010 parts by weight・Acrylic resin solution obtained in Production Example 2■ 133.3 parts by weight・Methylated melamine resin [heated Residue 98% by weight, Cymel 303, manufactured by American Cyanamid Company, trade name 1 13.3 parts by weight 10% by weight xylene solution of Tinuvin 900 [see above, (
1)] 10.0 parts by weight hindered amine light stabilizer L Sanol LS440,
10.0 parts by weight of a 10% by weight xylene solution manufactured by Ciba Geigy, trade name] 1.6 parts by weight of a sulfonic acid catalyst [(1) above], 1.0 parts by weight of n-butyl alcohol. , the coating viscosity (
A clear coat coating material was prepared by diluting the solution to 4.20° C. for 25 seconds.

(3) Preparation of coating film A cationic electrodeposition paint [trade name Aqua No. 4200, manufactured by NOF Corporation] was applied to a zinc phosphate-treated mild steel plate to a dry film thickness of 2
Electrodeposition coating was applied to a thickness of 0 μm, baked at 175°C for 25 minutes, and then an intermediate coating [Product Name Ko Pico No. 1500] was applied.
A test plate was prepared by air spray painting CP Sealer (manufactured by NOF Corporation) to a dry film thickness of 40 μm and baking it at 140'C for 30 minutes. On this test plate, the above (
1) Apply the base coat paint at intervals of 1 minute and 30 seconds.
Air spray painting was performed in two stages to a dry film thickness of 20 μm. After being set horizontally for 3 minutes, the clear coat paint described in (2) above was applied by air spray and baked horizontally at a temperature of 140°C for 30 minutes to obtain a smooth coating film. Furthermore, as shown in Table 5, this coating film had excellent acid resistance and weather resistance.

Examples 2 to 3 (1) Preparation of paints for base coats Each paint for base coats was prepared by performing the same operation as in Example 1 (1) using a mixture having the raw material composition shown in Table 3.

(Margin below) Table Note 1) Acrylic resin solutions obtained in Production Examples 1 to 3 2) Cynor 1168: Methyl butyl mixed alkyl etherified melamine resin, heating residue 98% by weight, manufactured by American Cyanamid Company, trade name Regiminch 55: Methyl butyl mixed alkyl etherified melamine resin, heating residue 100% by weight, manufactured by Monsanto, trade name 3) Non-aqueous dispersion of crosslinked polymer fine particles obtained in Production Example 4 4) Above, Example 1 5) Above, Example 1 6) Above, Example 1 (2) Creation of clear coat A mixture having the raw material composition shown in Table 4 was subjected to the same operation as in Example 1 (2). Each clear coat paint was created.

(Left below) (3) Creation of coating film Using the obtained paints (1) and (2), Example 1 (3)
) By performing the same operation as in Example 2.3, smoothness was achieved in all cases of Example 2.3, and as shown in Table 5, acid resistance and
A coating film with excellent weather resistance was obtained.

Example 4 (1) Creation of base coat paint/Production Acrylic resin solution obtained in Example 3 ■ 88.0 parts by weight/Production f! ! 55.7 parts by weight of non-aqueous dispersion A2 of crosslinked polymer fine particles obtained in 4. Aluminum paste 716ON [see above, Example 1, 15.
4 parts by weight, 10% by weight xylene solution of Tinuvin 900, isocyanate group content 21% by weight, 145.0 parts by weight of Coronate EH1 manufactured by Nippon Polyurethane Industries Co., Ltd., trade name, were added to thinner (toluene/xylene/acetic acid n). -Butyl-
Paint viscosity at 4/4/2 weight ratio (Ford Cup No. 4
．． A base coat paint was prepared by diluting the base coat at 20° C. for 14 seconds.

(2) Preparation of paint for clear coat - silicone compound [residue on heating 70% by weight, molecular weight 3.
000, hydroxyl equivalent of active ingredient 420, KR-211, manufactured by Shin-Etsu Chemical Co., Ltd., trade name 114.3 parts by weight・Acrylic resin solution obtained in Production Example 3 ■75.0 parts by weight・Tinuvin 900/10 Weight% quintessence solution [Supra, Example 1] [Supra, Example 1] 1000 parts by weight 10.0 parts by weight - Before dissolving 10% by weight of xylene, Sanol LS440 was mixed with hexamethylene solution before coating. [Supra, Example 1
] Diisocyanate trimer [heating residue 100%, 10
．． 0 parts by weight To the mixture having the above composition, 145.0 parts by weight of Corobut EH (see above, (1)) was added before coating, and thinner (xylene/n-butyl acetate-515 weight ratio) was added. Paint viscosity (
A clear coat paint was prepared by diluting Ford Cup N004 (25 seconds at 20°C).

(3) Creation of coating film Example 1 (3) using the obtained paints (1) and (2)
By performing the same operation as above, a smooth coating film with excellent acid resistance and weather resistance as shown in Table 5 was obtained.

(Leaving space below) Comparative Examples 1 to 3 (1) Creation of base coat paint A mixture having the same raw material composition as the base coat paint of Examples 1 to 3 was subjected to the same operation as Example 1 (1). , base coat paints of Comparative Examples 1 to 3 were prepared, respectively.

(2) Preparation of paints for clear coats Each paint for clear coats was prepared by performing the same operation as in Example 1 (2) using a mixture having the raw material composition shown in Table 6.

(Left below) (3) Creation of coating film Using the obtained paints (1) and (2), Example 1 (3)
), but as shown in Table 7, no coating film with satisfactory coating performance and weather resistance was obtained. That is, in Comparative Example 1, the acid resistance and bending resistance were insufficient, and the coating film was also slightly inferior in weather resistance. This was because the amount of silicone compound in the clear coat was less than 5% by weight, so the effect of improving acid resistance and weather resistance was insufficient, and the amount of curing agent in the clear coat was more than 50% by weight, resulting in poor bending resistance. It has become inferior to. In Comparative Example 2, although the effect of improving acid resistance and weather resistance was observed, the coating film had insufficient bending resistance. This is because the amount of silicone compound in the clear coat exceeded 50% by weight, and the amount of hydroxyl group-containing resin was less than 10% by weight. In Comparative Example 3, the coating film was insufficient in acid resistance and coating hardness. This was because the amount of silicone compound in the clear coat was less than 5% by weight, resulting in poor acid resistance, and furthermore, the amount of curing agent in the clear coat was less than 10% by weight, resulting in poor coating film hardness.

(The following is a blank space) [Effects of the Invention According to the present invention, the hydroxyl group chemically bonded to the silicon atom is
Contains 2 or more per molecule and has a weight average molecular weight of 20
By containing a silicone compound having a hydroxyl equivalent weight of 0 to 4,000 and a hydroxyl equivalent of 100 to 600, a high solid coating composition capable of forming a coating film with excellent acid resistance and weather resistance can be obtained.

Claims (1)

[Claims] 1 (A) Weight average molecular weight 200 to 4,000, having two or more hydroxyl groups per molecule chemically bonded to silicon atoms
and a silicone compound with a hydroxyl equivalent of 100 to 600 5 to
50% by weight, and (B) 10 to 80% by weight of hydroxyl group-containing resin.
and (C) a curing agent 1 having a functional group that can react with a hydroxyl group.
A high solids coating composition comprising as a main component a resin mixture of 0 to 50% by weight.