JP3163725B2 - Powder coating composition for forming a coating film having a turtle pattern, coating method, coating film and coated product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention have a hexagonal pattern on the surface of the coating film
The present invention relates to a powder coating composition for forming a coating film , a coating method thereof, a coating film and a coated product.

[0002]

2. Description of the Related Art Powder coatings have been widely used in the field of application due to their advantages of no pollution and labor saving. In recent years, however, there has been a strong demand for the development of powder coatings having a design property on the coating film surface. As a method for imparting a design property to a coating surface of a powder coating, for example, Japanese Patent Application Laid-Open No. 60-168771 discloses a method of mixing a polyester resin-based powder coating composition and an acrylic resin-based powder coating composition. Disclosed are powder coating compositions for precoating that provide a textured coating.

Japanese Patent Application Laid-Open No. 63-91168 discloses that two kinds of powder paints containing a powdery silicon-based additive in one or both of them are used, and two coats and one bake are performed to obtain a hammer tone, a pearl tone, etc. A method for forming a special pattern coating film by using a powder coating is disclosed. Japanese Patent Application Laid-Open No. 1-288376 discloses a method for producing a coated metal plate having a concavo-convex pattern by mixing a thermoplastic resin with a thermosetting powder coating to obtain a concavo-convex pattern.

However, in any of the coating compositions,
Although a simple concavo-convex pattern can be formed, a coating film having a turtle pattern that is uniform, dense, and excellent in design cannot be formed.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide a uniform, dense, three-dimensional appearance of a tortoiseshell pattern having excellent design properties, which is different from the conventional concavo-convex pattern, and is also excellent in coating film performance. It is intended to provide a powder coating composition for forming a coating film having a turtle pattern .

Another object of the present invention is a method for coating the above powder coating composition, which is excellent in coating film performance and, unlike conventional concavo-convex patterns, is uniform, dense and has a three-dimensional appearance. An object of the present invention is to propose a simple coating method for forming a turtle pattern having a design property.

Another object of the present invention is to provide a coating film formed from the above powder coating composition, which is excellent in coating film performance and, unlike conventional concavo-convex patterns, is uniform, dense, and three-dimensional. An object of the present invention is to provide a turtle-patterned coating film having excellent design properties.

Still another object of the present invention is a coated article having a coating film formed from the above powder coating composition, which is excellent in coating film performance and, unlike the conventional uneven pattern, is uniform and dense. Accordingly, it is an object of the present invention to provide a painted article on which a turtle pattern having an excellent design with a three-dimensional effect is formed.

[0009]

SUMMARY OF THE INVENTION The present invention provides the following powder coating composition, a coating method thereof, a coating film and a coated product. (1) (A) and the powder coating resin 60 to 95 parts by weight of solid at room temperature containing a hydroxyl group, (B) the following general formula room temperature in a solid represented by [1] tetraalkoxy methyl glycol U Lil 5 to 40 parts by weight

Embedded image (Wherein, R represents an alkyl group and at least 2 of 4
Each is a methyl group, and the rest is an alkyl group having 2 to 4 carbon atoms. (C) 0.1 to 3 parts by weight of a sulfonic acid compound blocked with an amine compound having a secondary or tertiary amino group having a boiling point of 80 to 250 ° C as sulfonic acid, relative to 100 parts by weight of the mixture comprising A powder coating composition for forming a coating film having a turtle pattern, characterized by the following. (2) After coating the powder coating composition according to (1) above on a substrate, baking at a temperature of 150 to 300 ° C. for 20 seconds to 60 minutes to form a coating film having a thickness of 20 to 200 μm. The coating method of the powder coating composition according to the above (1), which is characterized in that: (3) After the powder coating composition according to (1) is applied on a substrate, the composition is baked at a temperature of 150 to 300 ° C. for 20 seconds to 60 minutes, and has a thickness of 20 to 200 μm. A coating film formed from the powder coating composition according to the above (1). (4) After coating the powder coating composition according to the above (1) on a substrate, it has a coating film having a thickness of 20 to 200 μm formed by baking at a temperature of 150 to 300 ° C. for 20 seconds to 60 minutes. A coated article having a coating film formed from the powder coating composition according to the above (1).

As the resin for powder coating at room temperature and containing a hydroxyl group as the component (A) used in the present invention, any resin containing a hydroxyl group which is usually used for powder coating can be used without limitation. The hydroxyl value is 10 to 320 mgKOH /
g, preferably 25 to 300 mg KOH / g, and a glass transition temperature (Tg) of 30 to 120 ° C, preferably 35 to 1
A temperature of 00 ° C is desirable. As the component (A), for example, an acrylic resin containing a hydroxyl group, a polyester resin, a fluororesin and the like can be mentioned, and any of them can be used as a commercial product or a synthetic product.

As an acrylic resin for powder coating, for example, Almatex PD-800 manufactured by Mitsui Toatsu Chemicals, Inc.
0, PD-8100 and S.D. C. JONCRYL J-587, J-800, SCX manufactured by Johnson
-802 (all are trade names).

Examples of the polyester resin for powder coating include ER-6620 and ER-6 manufactured by Nippon Ester Co., Ltd.
640, XI-6021, XI-7909, XI-70
19. Fine Dick M-8000, M-8070, M-8076 manufactured by Dainippon Ink and Chemicals, Inc., Upikacoat GV-110, GV manufactured by Upika Japan
-150, GV-741, Hitachi Chemical Co., Ltd. P
C Resin 2H, 3H, URALAC P manufactured by DSM
-4215, 30-3000, 3 manufactured by CARGILL
0-3002, 30-3011, 30-3012, 30
-3020, UCB Crylcot 2383, 2392, 3145, Bayer Crelan
U-502, Alfalat manufactured by Hoechst
AN-739, AN-759, VAN9969
(Both are trade names).

Examples of the fluorine resin for powder coating include Lumiflon LF-710 manufactured by Asahi Glass Co., Ltd., and Cefral Coat manufactured by Central Glass Co., Ltd. (both are trade names). These components (A) can be used alone or in combination of two or more.

[0014] tetraalkoxy methyl glycol window drills (B) component used in the present invention has been made to be used as curing agent are those represented by the general formula (1). In the general formula [1], at least two Rs are a methyl group, the rest is an alkyl group having 2 to 4 carbon atoms, and all may be a methyl group. As the alkyl group having 2 to 4 carbon atoms other than the methyl group among the alkyl groups represented by R,
Examples include an ethyl group, an isopropyl group, a butyl group, and an isobutyl group.

[0015] In at least two methoxy groups of the alkoxy group is a functional group of tetraalkoxy methyl glycol window Lil, the remaining portion of the alkoxy group having 2 to 4 carbon atoms, and the methoxy group (A) component of The rapid cross-linking reaction with the hydroxyl group produces a three-dimensional turtle pattern. When three or more of the alkoxyl groups have 2 to 4 carbon atoms, these functional groups are compared with the methoxy group (A)
Since the reactivity with the hydroxyl group of the component is low, a three-dimensional turtle pattern is not formed or is insufficient.

Such a tetraalkoxymethyl glyco
The Lumpur U Lil, e.g. CYANAMID Co. P
underlink 1174 (trade name, all functional groups are methoxy groups) and the like.

The boiling point of component (C) used in the present invention is 80 to 2
A sulfonic acid compound blocked with an amine compound having a secondary or tertiary amino group at 50 ° C. (hereinafter sometimes referred to as a blocked acid catalyst) is used as a curing catalyst and includes, for example, p-toluenesulfonic acid, dodecyl Aromatic sulfonic acids such as benzenesulfonic acid, dinonylnaphthalenesulfonic acid, and dinonylnaphthalenedisulfonic acid, and the following structural formulas [2] to

One or two or more of the aliphatic sulfonic acids represented by [9] are used with a boiling point of 80 to 25.
Blocked with an amine compound having a secondary or tertiary amino group at 0 ° C.

[0018]

Embedded image (In the formula, R ¹ represents an alkyl group having 1 to 22 carbon atoms, R ² represents an alkyl group having 4 to 8 carbon atoms, and R ³ represents an alkyl group having 13 to 17 carbon atoms.)

The use of an aliphatic sulfonic acid is preferable because it has excellent compatibility with a resin as compared with an aromatic sulfonic acid, and thus has a low risk of crystallizing in a coating material and causing a bump in a coating film. Aliphatic sulfonic acid is obtained by converting sodium sulfonate or potassium salt of aliphatic sulfonic acid, which is generally used as a surfactant, into sodium salt or potassium salt to convert it to a free acid. Can be.

Here, examples of the aliphatic sulfonic acid salt as a starting material include those represented by the following structural formulas [10] to [17].

[0021]

Embedded image (In the formula, R ⁴ represents an alkyl group having 1 to 22 carbon atoms, R ⁵ represents an alkyl group having 4 to 8 carbon atoms, and R ⁶ represents an alkyl group having 13 to 17 carbon atoms.)

These aliphatic sulfonic acid salts can be converted to the free acid by desodiumization or depotassiumization with an inorganic acid. Aliphatic sulfonic acid salts having less than 4 carbon atoms have difficulty in compatibility with resins like aromatic sulfonic acids, and therefore those having 4 or more carbon atoms are preferred.

As the above-mentioned inorganic acid, usual sulfuric acid, hydrochloric acid,
Nitric acid, phosphoric acid, or the like can be used. At this time, the amount of the inorganic acid used is not limited, but later coating film performance,
In particular, in order not to impair the water resistance, the amount is preferably in the range of 0.5 to 1.5 times equivalent to the aliphatic sulfonate.

If the amount is less than 0.5 equivalents, unreacted aliphatic sulfonate remains. If the amount exceeds 1.5 equivalents, the aliphatic sulfonate is not treated with sodium or potassium. In any case, the water resistance of the coating film is lowered, which is not preferable. The conditions for sodium removal or potassium removal can be quantitatively determined at room temperature according to a conventional method.

Other acid catalysts include organic carboxylic acids such as maleic acid and phthalic acid, carboxylic acids inherent in polyols, and phosphate catalysts, all of which have a weak action as an acid catalyst and are described above. promoting effect of the crosslinking reaction for the hexagonal pattern formed in combination with tetraalkoxy methyl glycol window Lil weak. Also, the use of unblocked sulfonic acid does not provide a turtle pattern.

The amine compound having a boiling point of 80 to 250 ° C. and having a secondary amino group as a blocking agent includes, for example, di-2-ethylhexylamine, disecondary butylamine, diallylamine, N-methylhexylamine,
-Pipecoline, 4-pipecholine, 2,4-lupetidine,
2,6-lupetidine, 3,5-lupetidine, morpholine, N-methylbenzylamine; amine compounds having a tertiary amino group include, for example, N-methylmorpholine,
Triethylamine, tributylamine, N, N-dimethylallylamine, N-methyldiallylamine, triallylamine, N, N, N ', N'-tetramethyl-1,2
-Diaminoethane, N, N, N ', N'-tetramethyl-1,3-diaminopropane, N, N, N', N'-tetraallyl-1,4-diaminobutane, N-methylpiperidine, pyridine, 4-ethylpyridine, tripropylamine, N-propylpyridylallylamine, 3-dimethylaminopropanol, 2-ethylpyrazine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, 2,4-lutidine, 2,5- Lutidine, 3,4-lutidine, 3,5
-Lutidine, 2,4,6-collidine, 2-methyl-4-
Ethylpyridine, 2-methyl-5-ethylpyridine,
N, N, N ', N'-tetramethylhexamethylenediamine, N-ethyl-3-hydroxypiperidine, 3-methyl-4-ethylpyridine, 3-ethyl-4-methylpyridine, 4- (5-nonyl) Pyridine; amine compounds having secondary and tertiary amino groups include, for example, imidazole and N-methylpiperazine;
A mixture of two or more species is used.

If the boiling point of the blocking agent is less than 80 ° C., the dissociation of the blocking agent is too fast, so that foaming occurs in the coating film and a three-dimensional turtle pattern cannot be obtained. Dissociates too slowly to obtain a turtle pattern.

The production of the blocked sulfonic acid compound is as follows:
An amine compound having a tertiary or tertiary amino group and a sulfonic acid are charged in a container and stirred at 20 to 30 ° C. for 10 to 20 minutes.

The mixing ratio of the amine compound / sulfonic acid is 0.5 to 2, preferably 0.8 to 1.5 in molar ratio, and only in this case, a beautiful three-dimensional turtle pattern is formed. . When the molar ratio of the amine compound / sulfonic acid is less than 0.5, there are many sulfonic acids which are not blocked, so that the curing reaction proceeds from a low temperature at the time of baking, and a three-dimensional turtle pattern is not formed. When the ratio exceeds 2, no improvement is observed by the addition of the blocking agent, and the corrosion resistance of the obtained coating film decreases.

The mixing ratio of each component is as follows: Component (A) 60 to 9
5 parts by weight, 0 preferably a 65-9 4 parts by weight, (B) component 5-40 parts by weight, preferably to 100 parts by weight of the mixture consisting of 6 to 35 parts by weight, (C) component as acid 0.1 to 3 parts by weight, preferably 0.2 to 2 parts by weight.

[0031] When the amount of the component (A) exceeds the less than 60 parts by weight or 9 4 parts by weight, reaction with tetra-alkoxymethyl glycol U Lil (B) is insufficient, there is a three-dimensional effect And it is difficult to form a uniform turtle pattern.

If the amount of the component (B) is less than 5 parts by weight, sufficient crosslinking is not carried out, and a three-dimensional turtle pattern is unlikely to be formed. This makes it difficult to obtain a three-dimensional tortoiseshell pattern.

If the amount of the component (C) is less than 0.1 part by weight, the catalytic effect at the time of baking is insufficient, so that a three-dimensional tortoiseshell pattern is not formed. On the other hand, when the amount exceeds 3 parts by weight, the reaction is too fast to cause cracks, and there is no three-dimensional effect, and sufficient corrosion resistance cannot be obtained.

The powder coating composition of the present invention contains (A)
In addition to the essential components of (C), coloring pigments such as inorganic pigments such as titanium dioxide, red iron oxide, yellow iron oxide and carbon black, phthalocyanine blue, phthalocyanine green, quinacridone red pigment, and isoindolinone yellow pigment; Organic pigments; metal powders such as aluminum powder and copper powder; talc, barium sulfate, silica, calcium carbonate,
Extenders such as alumina white and clay; mica powder and the like may be added. In both cases of the clear powder coating and the colored powder coating, a thermoplastic resin containing no hydroxyl group, such as a fluororesin, a vinyl copolymer resin, a polyethylene resin, a polypropylene resin, and a polyester resin can be added.

These pigments, metal powders, thermoplastic resins and the like are used in an amount of 40 parts by weight per 100 parts by weight of the powder coating composition of the present invention.
It is preferably less than part by weight, and can be used as a pattern adjuster for adjusting the size of the pattern of the turtle pattern. If the amount used exceeds 40 parts by weight, the corrosion resistance of the coating film is reduced.

In addition, additives such as a leveling agent, a pigment dispersant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, and an antifoaming agent may be added to the powder coating composition of the present invention as required. Can also. Also, add silicone resin additives,
By intentionally repelling the coating film, a hammer tone tone and a turtle pattern can be imparted.

Usually, the powder coating mainly uses the electrostatic spraying method. Therefore, from the viewpoint of the coating workability (coating efficiency and throwing power), the particle diameter of the powder coating composition of the present invention is 15%.
Desirably, the mesh size is 0 mesh or less.

As the substrate on which the powder coating composition of the present invention is coated, any substrate can be used as long as it can withstand the baking conditions described below. A metal plate such as a steel plate, an aluminum plate, and a stainless steel plate is preferable.

To apply the powder coating composition of the present invention,
A commercially available electrostatic coating machine (loading voltage -50)
~ -90 kV) or evenly by powder coating, etc., then 150 ~ in hot air baking furnace, infrared furnace, induction heating furnace, etc.
300 ° C, preferably at 160 to 250 ° C for 20 seconds to 60
For 20 minutes, preferably 30 seconds to 30 minutes.
The coating thickness is set to 00 μm, preferably 30 to 100 μm. By coating in this manner, a turtle-patterned coating film having excellent coating performance such as corrosion resistance and excellent three-dimensional appearance is formed.

The baking conditions are determined in the above range according to the base material (substrate) to be used. For example, when a 0.5 mm thick iron plate is used, baking may be performed at 160 to 180 ° C. for 15 to 20 minutes. . When the coating thickness of the powder coating is less than 20 μm, a sufficient three-dimensional turtle pattern cannot be obtained.
If it exceeds m, a foaming phenomenon occurs in the coating film, and a beautiful turtle pattern cannot be obtained.

The coating film formed by baking the powder coating composition of the present invention has dense (fine) irregularities in the form of a crepe pattern in a two-dimensionally unspecified direction. It varies depending on the composition of the paint, the coating conditions, the baking conditions, and the like. By preparing these, a coating film having an arbitrary turtle pattern can be obtained.

FIG. 1 is a schematic plan view schematically showing a coated article formed from the powder coating composition of the present invention, and FIG. 2 is a schematic sectional view thereof.

In the figure, reference numeral 10 denotes a coating material, on which a coating film 2 is formed on a substrate 1. In the coating film 2, a high and tortoise-shaped irregular network pattern 3 is formed almost uniformly on the entire surface of the coating film 2, and furthermore, a crepe-shaped dense unevenness 4 is formed on the inside of the coating film 2 in an unspecified direction. It is formed almost uniformly, is uniform and dense as a whole, and has a three-dimensional appearance and has an excellent design.

A coated article having a coating having such a turtle pattern has excellent design properties and excellent coating performance such as corrosion resistance. Household appliances such as washing machines and air conditioners; Road materials such as poles, soundproof walls, and guardrails; Building materials such as inner and outer walls, pillars, roofs, and partition boards of buildings;
Telecommunications equipment; metal products such as iron, galvanized steel, stainless steel, aluminum, etc. such as pipes, fittings, metal machinery, garbage cans, glove compartments, steel furniture, steel desks, and beverage cans;
It can be used in the fields of glass, wood, gypsum board, woven fabric made of glass fiber or the like as a raw material, heat-resistant paper, plastics having a heat resistance of 150 ° C. or more, and printed or colored materials thereof.

Although the mechanism of the formation of the turtle pattern has not been fully elucidated, when the uncured coating film reaches a certain baking condition, rapid surface hardening progresses, so that the surface layer is distorted and corrected. Therefore, it is considered that a turtle pattern appears on the surface layer. In the present invention, in the presence of a sulfonic acid catalyst (blocked acid catalyst) blocked with a specific amine compound, tetraalkoxymethyl containing a large amount of a methoxy group highly reactive with a hydroxyl group of the resin (A) for powder coating materials. by blending glycol U Li <br/> Le, it is estimated that the hexagonal pattern caused by such a rapid surface hardening at baking.

[0046]

As described above, according to the present invention, according to the present invention, a solid at room temperature containing a hydroxyl group in the powder coating resin, solid at room temperature tetraalkoxy methyl glycol U Lil and having a boiling point of 80 to 250 ° C. The sulfonic acid compound blocked with an amine compound having a secondary or tertiary amino group is blended at a specific ratio, so that unlike the conventional uneven pattern, it is uniform and dense, and has excellent three-dimensional appearance. hexagonal pattern having a can form a coating film having, moreover powder coating composition for forming a coating film having excellent hexagonal pattern in the coating film performance.

According to the present invention, the powder coating composition can be easily applied.

According to the present invention, there is further provided a coating film formed from the above powder coating composition, which is excellent in coating film performance, and which is different from the conventional concavo-convex pattern in that it is uniform, dense, and has a three-dimensional appearance. A turtle-patterned coating film having a certain excellent design property can be obtained, and a coated article having such a coating film can be obtained.

[0049]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In each example, parts are parts by weight and% is% by weight.
Is shown.

Example 1 Based on the composition shown in Table 1, Almatex PD-8000 (trade name, solid content: 100, manufactured by Mitsui Toatsu Chemicals, Inc.)
%) And Powder manufactured by CYANAMID
Ink 1174 (trade name, solid content 100%, all functional groups are methoxy groups), 25 parts, and tritoluene-blocked paratoluenesulfonic acid 2.0 as a tertiary amine-blocked sulfonic acid having a boiling point of 80 to 250 ° C. , And uniformly mixed for about 1 minute by a drive render (manufactured by Mitsui Kakoki Co., Ltd., trade name: Hellschl mixer), and then an extrusion kneader (manufactured by Bus Co., Ltd.) at a temperature of 80 to 100 ° C. The mixture was melt-kneaded using a trade name Buscon Kneader PR-46), cooled, and finely pulverized with a hammer-type impact pulverizer.
Next, the mixture was filtered through a 150-mesh wire net to obtain a powder coating.

The obtained powder coating is 0.5 mm × 100 m
Electrostatic coating is performed on an iron plate having a zinc phosphate treatment of mx 200 mm and baked at 170 ° C for 20 minutes to obtain a coating thickness of 50 mm.
A μm coated plate was obtained. A turtle pattern as shown in FIG. 1 was formed on the painted plate. Table 1 shows the appearance of the obtained coated plate and the performance of the cured coating film.

Examples 2 to 8, Comparative Examples 1 to 4 Based on the formulations of Examples 2 to 8 and Comparative Examples 1 to 4 in Tables 1 and 2, Powder coatings of Comparative Examples 1 to 4 were obtained. The obtained powder coating materials of Examples 2 to 8 and Comparative Examples 1 to 4 were coated in the same manner as in Example 1 by 0.5 m.
m × 100 mm × 200 mm, coated on an iron plate subjected to a zinc phosphate treatment, Examples 2 and 6 to 8 and Comparative Examples 1 to 4
Baking was performed at 70 ° C. for 20 minutes and Examples 3 to 5 at 180 ° C. for 20 minutes to obtain coated plates having a coating thickness of 50 μm.
Tables 1 and 2 show the appearance of each coated plate and the performance of the cured coating film.

[0053] In Table 1, Examples 1 and 2 (A) Type of acrylic resins for powder coatings which contain components of hydroxyl group and (B) components of tetramethoxymethyl glycol U Li <br/> Le an example of changing the ratio of, example 3-7 (a) type polyester resin for powder paint containing components of hydroxyl group, (B) component of tetramethoxymethyl glycol U <br / Example 8 is an example in which a change in the ratio to ril and a pattern adjusting agent are added, and Example 8 is an example in which a fluororesin is used as a resin for a powder coating containing a hydroxyl group as the component (A).

[0054]

[Table 1]

[0055]

[Table 2]

Footnotes to Tables 1 and 2 1) Mitsui Toatsu Chemicals, Inc., trade name, acrylic resin, hydroxyl value = 87 mgKOH / g, solid content = 100%, Tg
= 65 ° C 2) S.P. C. Manufactured by Johnson Corporation, trade name, acrylic resin, hydroxyl value = 94 mgKOH / g, solid content = 100
%, Tg = 50 ° C. 3) Nippon Ester Co., Ltd., trade name, polyester resin, hydroxyl value = 29 mg KOH / g, solid content = 100
%, Tg = 63 ° C. 4) CARGILL, trade name, polyester resin,
Hydroxyl value = 295 mg KOH / g, solid content = 100%,
Tg = 44 ° C. 5) Hitachi Chemical Co., Ltd., trade name, polyester resin, hydroxyl value = 100 mgKOH / g, solid content = 100
%, Tg = 58 ° C. 6) Asahi Glass Co., Ltd., trade name, fluororesin, hydroxyl value =
52 mg KOH / g, solid content = 100%, Tg = 60 ℃ 7) CYANAMID trade name, tetramethoxy methyl glycol U Lil (R four with methyl groups of the general formula (1)) solids = 8) paratoluenesulfonic acid blocked with tripropylamine, tripropylamine / paratoluenesulfonic acid = 1/1 (molar ratio), tripropylamine boiling point = 15
6.5 ° C. 9) Hosterflon 9205 (trademark), manufactured by Hoechst
Tetrafluorocarbon 10) Parts by weight with respect to 100 parts by weight of resin and curing agent 11) Visual judgment Good: A turtle pattern was formed on the entire surface Poor: No turtle pattern was formed on the entire surface 12) Visual judgment Good: There was a three-dimensional impression Good: Three-dimensional No feeling 13) JIS K-5400, paragraph 9.1 Good: no rust or blister on the coating film Bad: rust or blister on the coating film

[0057] Table 1 and Table 2, whereas the Examples 1 to 8 are excellent in corrosion resistance with providing good hexagonal pattern and three-dimensional appearance, tetramethoxymethyl <br/> glycol Le c Lil is Comparative example 2 Comparative example of less than 5 parts by weight 1 and tetramethoxymethyl glycol window Lil exceeds 40 parts by weight do not provide a hexagonal pattern and three-dimensional appearance, yet corrosion resistance was poor.

In Comparative Example 3 in which the amount of the blocked acid catalyst was less than 0.1 part by weight, the crevices and three-dimensional effect were not obtained, and in Comparative Example 4 in which the amount of the blocked acid catalyst exceeded 3 parts by weight, the three-dimensional effect was obtained. And the corrosion resistance was poor.

[Brief description of the drawings]

FIG. 1 is a schematic plan view schematically showing a coated article formed from the powder coating composition of the present invention.

FIG. 2 is a schematic sectional view of the painted object of FIG.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 base material 2 coating film 3 irregular network pattern 4 dense unevenness 10 painted object

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-78605 (JP, A) JP-A-4-328172 (JP, A) JP-A-2-240178 (JP, A) JP-A-4- 1353 (JP, A) JP-B 61-16780 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 5/28

Claims (4)

(57) [Claims] 1. A (A) and the powder coating resin 60 to 95 parts by weight of solid at room temperature containing a hydroxyl group, (B) a solid tetraalkoxy methyl glycol at room temperature of the general formula [1] and c Lil 5 to 40 parts by weight of 1] (Wherein, R represents an alkyl group and at least 2 of 4
Each is a methyl group, and the rest is an alkyl group having 2 to 4 carbon atoms. (C) 0.1 to 3 parts by weight of a sulfonic acid compound blocked with an amine compound having a secondary or tertiary amino group having a boiling point of 80 to 250 ° C as sulfonic acid, relative to 100 parts by weight of the mixture comprising A powder coating composition for forming a coating film having a turtle pattern, characterized by the following. 2. After the powder coating composition according to claim 1 is applied on a substrate, the composition is heated at a temperature of 150 to 300 ° C. for 20 seconds to 60 hours.
The method for coating a powder coating composition according to claim 1, wherein the coating is formed by baking for 20 minutes to form a coating film having a thickness of 20 to 200 µm. 3. After the powder coating composition according to claim 1 is applied on a substrate, the composition is heated at a temperature of 150 to 300 ° C. for 20 seconds to 60 hours.
The coating film formed from the powder coating composition according to claim 1, wherein the coating film is formed by baking for 20 minutes and has a thickness of 20 to 200 µm. 4. After applying the powder coating composition according to claim 1 on a substrate, the composition is heated at a temperature of 150 to 300 ° C. for 20 seconds to 60 hours.
A coated article having a coating film formed from the powder coating composition according to claim 1, having a coating film having a thickness of 20 to 200 µm formed by baking for minutes.