JPH091050A - Paint film forming method - Google Patents

Abstract

PURPOSE: To reduce the total thickness of a film and to form a double layered paint film with good gloss feeling by specifying the average particle size of the pigment and the weight percentage of each component of each paint when a thermosetting colored paint containing aluminum fine powder and a titanium pigment and a thermosetting metallic paint containing a metallic pigment are used. CONSTITUTION: In a 4-coat 2-bake system paint film forming method, an article is coated with a colored paint A, a metallic paint B, and a clear paint C in sequence by a wet method, and the paint film is heated to be cured. The product is coated with a clear paint, and the paint film is cured. In this paint film forming method, the colored paint A is a thermosetting colored dye which contains a base substance resin, a crosslinking agent, aluminum fine powders of at most 10μm longitudinal average particle size, and a titanium pigment and has the covering power of the cured paint film of 25μm or less. The metallic paint B is a thermosetting metallic paint which contains a base resin, a crosslinking agent, and a metallic pigment of 20-50μm longitudinal average particle size and has 5-15 pts.wt. pigment content per 100 pts.wt of the total amount of the base resin and the crosslinking agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a metallic coating film in which a colored coating material, a metallic coating material, and two types of clear coating materials are used in a four-coat, two-bake method. The present invention relates to a novel method capable of forming a metallic coating film.

[0002]

2. Description of the Related Art It is known that a multi-layer metallic coating film is formed by sequentially coating a coating material with a colored coating material, a metallic coating material and a clear coating material. The multi-layer coating film imparts a cosmetic property in combination with the glittering feeling of the metallic coating film and the color tone of the underlying colored coating film.

However, conventionally, in this method, since the colored coating material hides the lower layer, it is necessary to apply a cured coating film to a thick film of 30 μm or more, and there is a problem that the glittering feeling is not sufficient. There is.

[0004]

Means for Solving the Problems The present inventors have improved the concealing property of a colored coating film in the above-mentioned multilayer metallic coating film to reduce the film thickness thereof, and to provide a multilayer coating film excellent in brilliance. The research was repeated about the formation method. As a result, a colored paint containing aluminum fine powder having a specific particle size and a titanium oxide pigment is used as the colored paint, and a thermosetting metallic paint containing a metallic pigment having a specific particle size is used as the metallic paint. As a result, they have found that the above object can be achieved, and completed the present invention.

That is, according to the present invention, a colored coating material (A), a metallic coating material (B), and a clear coating material (C) are sequentially applied to an object to be coated by wet-on-wet and then heated to form the three-layer coating film. After curing at the same time, a clear coating (D) is applied to the cured coating surface of the clear coating (C),
In the 4-coat 2-bake coating film forming method for heating and curing the coating film, the colored coating material (A) comprises a base resin, a cross-linking agent, an aluminum fine powder having an average particle size in the longitudinal direction of 10 μm or less, and a titanium oxide pigment. It is a thermosetting colored coating material containing, the hiding power of the cured coating film is 25 μm or less,
The metallic paint (B) contains a base resin, a cross-linking agent, and a metallic pigment having an average particle size in the longitudinal direction of 20 to 50 μm, and the content of the pigment is 100 in total of the base resin and the cross-linking agent. The present invention relates to a method for forming a metallic coating film, which is a thermosetting metallic coating material in an amount of 5 to 15 parts by weight per part by weight.

The present invention will be described in detail below.

The article to be coated in the method of the present invention includes, for example, a metal or plastic material used for an outer panel of an automobile, and the material is, if necessary,
An undercoat paint such as a cationic electrodeposition paint or an intermediate paint may be applied and cured.

The colored coating material (A) in the method of the present invention comprises a base resin, a cross-linking agent, fine aluminum powder having an average particle size of 10 μm or less in the longitudinal direction and a titanium oxide pigment, and has a hiding power of 25 μm for a cured coating film. The following thermosetting colored coating composition is applied to the lower layer (on the side of the coated article) of the coating film of the metallic coating composition (B). In particular, by blending aluminum powder having an average particle size in the longitudinal direction of 10 μm or less and a titanium oxide pigment, the hiding power of the cured coating film is 25 μm.
It is characterized in that it was adjusted so that it was less than m.

The coating material (A) has an excellent hiding power, and even a thin film having a cured film thickness of 25 μm or less, particularly 8 to 15 μm, can sufficiently hide the substrate (for example, the intermediate coating surface immediately below). .

As the preferable base resin in the coating material (A), for example, acrylic resin, polyester resin, alkyd resin having a crosslinkable functional group such as hydroxyl group can be used. Further, as a preferable cross-linking agent, melamine resin, amino resin such as urea resin and polyisocyanate,
Blocked polyisocyanates and the like can be used. Also,
The paint (A) is preferably an organic solvent type.

The fine aluminum powder used in the coating material (A) is mainly flaky particles having an average particle size in the longitudinal direction of 10 μm or less, preferably 3 to 7 μm. If the average particle size is larger than 10 μm, the hiding property of the coating film is deteriorated, which is not preferable. The thickness is usually 0.0
It is preferably about 1 to 1 μm.

Here, the "average particle diameter" in the present invention means the median diameter by the laser diffraction scattering method.

The component of the fine aluminum powder is preferably metallic aluminum, and its surface may be treated with a silane coupling agent or the like.

As the titanium oxide pigment, known pigments for paints can be used, and those having an average particle diameter of 5 μm or less, particularly about 0.01 to 2 μm are preferable. The titanium oxide pigment may have its surface treated with alumina or silica.

The fine aluminum powder and the titanium oxide pigment are blended in an amount of 0.1 to 30 parts by weight, particularly 1 to 5 parts by weight, based on 100 parts by weight (solid content) of the base resin and the crosslinking agent. Titanium oxide pigment 1-20
It is preferably 0 parts by weight, particularly 10 to 100 parts by weight. When the fine aluminum powder deviates from this range, the finishability may be deteriorated, and when the fine titanium oxide pigment deviates from this range, the lightness may be increased, which is not preferable.

Further, it is essential to use the aluminum powder and the titanium oxide pigment together in the paint (A),
The total content of these components is such that the hiding power of the coating film of the coating material (A) is 25 μm or less (as a cured coating film). Specifically, per 100 parts by weight (solid content) of the base resin and the cross-linking agent, the total amount of the aluminum fine powder and the titanium oxide pigment in the above range is about 2 to 230 parts by weight, particularly 60 to 130 parts by weight. It is preferably about the same.

The hiding power is the minimum film thickness at which the color of the base material cannot be visually recognized. Specifically, it is impossible to visually distinguish black and white through a coating film applied on a black and white plate. Is the minimum film thickness (in the cured coating film). Paint (A)
However, since the fine aluminum powder and the titanium oxide pigment are used in combination, the hiding power of the thin film can be 25 μm or less. The lack of any of these does not provide the hiding power of such thin films.

The coating material (A) comprises the above-mentioned components and is obtained by mixing and dispersing these in an organic solvent. In addition to the above components, other color pigments, metallic pigments, extender pigments and the like can be appropriately added to the coating material (A), if necessary.

In the present invention, the colored coating material (A) is applied to the surface to be coated by electrostatic coating, air spraying, airless spraying, etc., based on the cured coating film, and is about 8 to 25 .mu.m, particularly 8 to 1 .mu.m.
It is preferable to apply the coating with a film thickness of 5 μm. Although the coating film itself of the coating material (A) thus obtained contains fine aluminum powder, since the powder is fine powder,
It does not have a glittering feeling.

In the present invention, the coating film (A) is not crosslinked and cured, and the following metallic paint (B) is applied to the coated surface.

The metallic paint (B) is applied to the unhardened coated surface of the wet paint of the above-mentioned colored paint (A), and comprises a base resin, a cross-linking agent, and an average particle size in the longitudinal direction of 20 to 50 μm.
Which is 5 to 100 parts by weight per 100 parts by weight of the total amount of the base resin and the crosslinking agent.
The thermosetting metallic paint is 15 parts by weight. In particular, it is characterized in that 5 to 15 parts by weight of a metallic pigment having an average particle size in the longitudinal direction of 20 to 50 μm is contained per 100 parts by weight of the total amount (solid content) of the base resin and the crosslinking agent.

The coating film of the metallic coating material (B) has a relatively small hiding property, and the color tone of the coating film of the coating material (A) as an underlying layer may be seen through.

As the preferable base resin in the coating material (B), for example, an acrylic resin, a polyester resin, an alkyd resin having a crosslinkable functional group such as a hydroxyl group can be used. Further, as a preferable cross-linking agent, melamine resin, amino resin such as urea resin and polyisocyanate,
Blocked polyisocyanates and the like can be used. Also,
The paint (B) is preferably an organic solvent type.

The metallic pigment used in the metallic paint (B) is preferably a flaky powder such as aluminum, mica, colored mica, and mica-like iron oxide.
The average particle size in the longitudinal direction of these metallic pigments is 20 to
50 μm, preferably 30-40 μm, 20 μm
If it is smaller than m, the luster is deteriorated, and if it is larger than 50 μm, the finished appearance of the coating film is deteriorated, which is not preferable. The thickness is 1/5 to 1/20 of the particle size.
It is preferably about the same.

The metallic powder is blended in an amount of 5 to 15 parts by weight per 100 parts by weight of the total amount of the base resin and the cross-linking agent (solid content). If it is less than 5 parts by weight, the luster is deteriorated. If the amount is more than 15 parts by weight, the finished appearance of the coating film is deteriorated, which is not preferable.

The paint (B) comprises the above-mentioned components, and is obtained by mixing and dispersing them in an organic solvent. In addition to the above components, other color pigments, extender pigments, and the like can be appropriately added to the coating material (B), if necessary.

Further, the coating film hiding power of the metallic coating material (B) is preferably 20 μm or more, particularly about 50 to 200 μm, and the hiding power can be adjusted by the kind of the metallic pigment or the coloring pigment and the blending amount thereof. .

The metallic coating material (B) is applied to the surface of the coating film (A) of the end-cured colored coating material by electrostatic coating, air spraying, airless spraying or the like to give a film thickness of about 10 to 15 μm (as a cross-linking cured coating film). It is preferable to paint so that

According to the method of the present invention, the coloring paint (A) is colored in a dark color (for example, J) in relation to the color tone of the coloring paint (A) and the content of the metallic pigment of the metallic paint (B).
L value in Lab colorimetric system based on ISZ8729 is 3
0 or less, particularly preferably 5 to 25), the metallic pigment in the metallic paint (B) has a glitter of the metallic pigment when the amount is 5 to 10 parts by weight per 100 parts by weight of the base resin and the crosslinking agent (solid content). In the metallic paint (B), when the coloring paint (A) is made to have a light color (for example, L value in Lab colorimetric system exceeds 30, particularly 35 to 95 is preferable) It is preferable that the amount of the metallic pigment is 10 to 15 parts by weight per 100 parts by weight of the base resin and the cross-linking agent (solid content) because the metallic unevenness of the metallic coating film can be prevented.

In the present invention, the metallic paint (B) is not crosslinked and cured, and the clear paint (C) is applied to the coated surface.

The clear coating material (C) is a thermosetting coating material which is applied to the uncured coating surface of the metallic coating material (B) and contains a base resin and a crosslinking agent.
The paint (C) is usually an organic solvent type liquid paint composition and forms a transparent coating film.

As a preferable base resin in the coating material (C), for example, an acrylic resin, a polyester resin, an alkyd resin having a crosslinkable functional group such as a hydroxyl group can be used. Further, as a preferable cross-linking agent, melamine resin, amino resin such as urea resin and polyisocyanate,
Blocked polyisocyanates and the like can be used.

The clear coating (C) does not use a crosslinking agent such as amino resins such as melamine resin and urea resin, and has functional groups such as hydroxyl group, carboxyl group, epoxy group, silanol group and isocyanate group. It is also possible to use a coating composition comprising a base resin having a crosslinking agent having a group capable of reacting with these functional groups, for example, a hydroxyl group, a carboxyl group, an epoxy group, a silanol group, an isocyanate group and the like.

The clear coating material (C) is prepared by blending the above-mentioned respective components and mixing or dissolving them in an organic solvent to dissolve or disperse them. In principle, the clear paint (C) contains no coloring pigment.

The clear coating (C) is applied to the coating surface of the end-cured metallic coating (B) by a method such as electrostatic coating, air spraying, airless spraying or the like, based on the cured coating, about 30 to 40 μm. It is preferable to apply the coating so that the film thickness becomes.

In the present invention, the above-mentioned colored paint (A), metallic paint (B) and clear paint (C) are sequentially applied by wet-on-wet, and then heated to the above 3
The coatings of the layers are simultaneously cured.

That is, the colored coating material (A) is applied to the object to be coated by a method such as electrostatic coating, air spraying or airless spraying so as to have a film thickness of about 8 to 25 μm based on the cured coating film. To do. Then, usually, after leaving at room temperature, the metallic coating (B) is applied to the uncured coating surface of the colored coating (A) by a method such as electrostatic coating, air spraying, airless spraying or the like based on the cured coating film. Paint so that the film thickness is about 15 μm. Further, usually, after leaving at room temperature, the clear coating (C) is applied to the uncured coating surface of the metallic coating (B).
Is applied by a method such as electrostatic coating, air spraying or airless spraying so as to have a film thickness of about 30 to 40 μm based on the cured coating film. In such a coating system, even when the colored coating material (A) and the metallic coating material (B) are applied wet-on-wet, neither mixed layer nor inversion is observed in both coating films.

In the present invention, in order to simultaneously heat cure the three-layer coating film comprising the coating material (A), the coating material (B) and the coating material (C), at a temperature of about 120 to 180 ° C. Heat for about 10 to 60 minutes.

In the present invention, the clear coating (D) is further applied to the coating surface of the clear coating (C) of the three-layer coating film thus cured. Only with the clear coating (C), the metallic pigment in the lower layer may be found,
They can be prevented by applying the clear paint (D).

As the clear paint (D), a paint selected from those explained in the above clear paint (C) can be used. The clear paint (D) and the clear paint (C) may have the same composition. The clear paint (D)
Is applied to the coating film surface of the cured clear coating material (C) by a method such as electrostatic coating, air spraying or airless spraying so as to have a film thickness of about 30 to 40 μm based on the cured coating film. It is preferable. Then, in order to heat-cure the clear coating (D) coating film, 120 to 180
Heating is performed at a temperature of about C for a time of about 10 to 60 minutes.

In this way, a metallic multi-layer coating film having a thin film and excellent brilliance is formed by the 4-coat 2-bake method of the present invention.

[0042]

【The invention's effect】

(1) Since the hiding power of the colored coating film in the multilayer coating film consisting of the colored coating film, the metallic coating film and the clear coating film is excellent, it is possible to reduce the total film thickness of the formed multilayer coating film. became.

(2) Even if a metallic coating is directly applied to the surface of the uncured colored coating film, no mixing layer or inversion occurs.

(3) It was possible to form a multilayer coating film having an excellent glittering feeling.

[0045]

EXAMPLES The present invention will be described more specifically below with reference to production examples, examples and comparative examples. In each case, parts and percentages are based on weight in principle.

Production Example 1 Production of Colored Paint (A) (A-1): 70 parts of hydroxyl group-containing acrylic resin (solid content), 30 parts of alkyl etherified melamine resin (solid content), aluminum fine powder (longitudinal average particle size) Diameter 5 μm)
3 parts and 80 parts of titanium oxide (average particle size: 0.05 μm) are mixed and dispersed in an organic solvent (a mixed solvent of toluene / xylene and the like) to give a solid content of 20% and a viscosity of 18 seconds (Ford cup # 4/20. C.), concealed film thickness of cured coating 13 to 1
A 5 μm colored coating material (A-1) was obtained.

(A-2): Hydroxyl group-containing acrylic resin 70
Parts (solid content), 30 parts of alkyl etherified melamine resin (solid content), aluminum fine powder (longitudinal average particle size 5
5 parts and titanium oxide (average particle size 0.05 μm)
90 parts of an organic solvent (a mixed solvent of toluene / xylene and the like) is mixed and dispersed to obtain a solid content of 20%, a viscosity of 18 seconds (Ford cup # 4/20 ° C.), and a concealed film thickness of the cured coating film of 10 to 13 μm. To obtain a colored paint (A-2).

(A-3): Hydroxyl group-containing acrylic resin 70
Parts (solid content), 30 parts of alkyl etherified melamine resin (solid content) and titanium oxide (average particle size 0.05 μm)
80 parts were mixed and dispersed in an organic solvent (mixed solvent such as toluene / xylene by weight) to give a solid content of 20%, a viscosity of 18 seconds (Ford cup # 4/20 ° C), and a concealed film thickness of the cured coating film 45 to 50 μm. To obtain a colored paint (A-3).

(A-4): Hydroxyl group-containing acrylic resin 70
Parts (solid content), alkyl etherified melamine resin 30 parts (solid content), aluminum powder (longitudinal average particle size 35
3 parts and titanium oxide (average particle size 0.05 μm)
80 parts was mixed and dispersed in an organic solvent (a mixed solvent such as toluene / xylene by weight) to give a solid content of 20%, a viscosity of 18 seconds (Ford cup # 4/20 ° C.), and a concealed film thickness of the cured coating film of 30 to 35 μm. To obtain a colored paint (A-4).

Production Example 2 Production of metallic paint (B) (B-1): 70 parts of hydroxyl group-containing acrylic resin (solid content), 30 parts of alkyl etherified melamine resin (solid content) and aluminum powder (longitudinal average particle size). 35μ
m) 10 parts by mixing with an organic solvent (a mixed solvent of toluene / xylene by weight) to obtain a solid content of 20% and a viscosity of 15
Second (Ford cup # 4/20 ° C.), a metallic coating (B-1) having a concealed film thickness of the cured coating film of 60 to 65 μm was obtained.

(B-2): Hydroxyl group-containing acrylic resin 70
Parts (solid content), 30 parts of alkyl etherified melamine resin (solid content) and 5 parts of aluminum powder (longitudinal direction average particle size 35 μm) are mixed and dispersed in an organic solvent (toluene / xylene equivalent weight mixed solvent) to give a solid. A metallic coating material (B-2) having a content of 20%, a viscosity of 15 seconds (Ford cup # 4/20 ° C.), and a hidden film thickness of the cured coating film of 65 to 70 μm was obtained.

(B-3): Hydroxyl group-containing acrylic resin 70
Parts (solid content), alkyl etherified melamine resin 30 parts (solid content), aluminum powder (longitudinal average particle size 35
μm) 10 parts and titanium oxide (average particle diameter 0.05 μm
m) 80 parts by mixing and dispersing in an organic solvent (a mixed solvent such as toluene / xylene by weight) to obtain a solid content of 20% and a viscosity of 15
Second (Ford cup # 4/20 ° C.), a metallic coating (B-3) having a concealed film thickness of the cured coating film of 20 μm was obtained.

Production Example 3 Production of Clear Coating (C) 70 parts of hydroxyl group-containing acrylic resin (solid content) and 30 parts of alkyl etherified melamine resin (solid content) are mixed with an organic solvent (a mixed solvent by weight such as toluene / xylene). Disperse, solid content 20%, viscosity 15 seconds (Ford Cup #
4/20 ° C.) clear coating material (C-1) was obtained.

Production Example 4 Production of clear paint (D) 70 parts (solid content) of a hydroxyl group-containing acrylic resin and 30 parts (solid content) of an alkyl etherified melamine resin are mixed with an organic solvent (mixed solvent such as toluene / xylene by weight). Disperse, solid content 20%, viscosity 15 seconds (Ford Cup #
4/20 ° C.) clear coating material (D-1) was obtained.

Example 1 A steel sheet was coated with a cationic electrodeposition coating composition containing an epoxy resin-based polyamino resin and a blocked isocyanate as a main component, heat-cured, and then an intermediate coating composition containing a polyester resin and a melamine resin as a main component was coated and cured. What was done was used as a to-be-coated article.

A colored paint (A-1) having a film thickness of 1 is applied to the article to be coated.
5 μm (the same applies hereinafter as a cured coating film), and allowed to stand at room temperature for 3 minutes before being applied with a metallic paint (B-
1) was applied to a film thickness of 13 μm and left at room temperature for 3 minutes, then clear coating (C-1) was applied to a film thickness of 40 μm and left at room temperature for 3 minutes, then 140 ° C. The above three-layer coating film was cured by heating for 30 minutes. Then, a clear paint (D-1) having a film thickness of 40 μm is applied to the surface of the clear coating film.
m, and leave at room temperature for 3 minutes, then 140 ℃
It was heated for 30 minutes to cure.

The total film thickness of the coating film obtained by the 4-coat 2-bake coating method of this example was 108 μm, and when the finish appearance was visually inspected, it was a film excellent in brilliance and glitter. It was

Example 2 A colored coating material (A-
2) is applied to a film thickness of 15 μm and left at room temperature for 3 minutes, and then metallic paint (B-2) is applied to a film thickness of 13 μm.
And then leave it at room temperature for 3 minutes, then apply clear coating (C-1) to a film thickness of 40 μm, leave it at room temperature for 3 minutes, and then heat it at 140 ° C. for 30 minutes. The above three-layer coating film was cured. Then, the clear coating film (D-1) was applied to the surface of the clear coating film so that the film thickness was 40 μm, left at room temperature for 3 minutes, and then heated at 140 ° C. for 30 minutes to cure.

The total film thickness of the coating film obtained by the 4-coat 2-bake coating method of the present example was 108 μm, and when the finished appearance was visually inspected, it was a film excellent in glitter and brilliance. It was

Comparative Example 1 The same coating material as in Example 1 was coated with the metallic paint (B-3) to a film thickness of 2 without coating the colored paint (A).
After coating to a thickness of 8 μm and standing at room temperature for 3 minutes, clear coating (C-1) was coated to a thickness of 40 μm and standing at room temperature for 3 minutes, and then clear coating (D-
1) was applied to a film thickness of 40 μm, left at room temperature for 3 minutes, and then heated at 140 ° C. for 30 minutes to cure the three-layer coating film.

The total film thickness of the coating film obtained by the three-coat one-bake coating method of this comparative example was 108 μm, but when the finished appearance was visually inspected, it was a coating film with inferior brilliance. It is considered that this is because the coloring paint (A) was not applied and the metallic paint (B-3) contained a large amount of the coloring pigment.

Comparative Example 2 The same coating material as in Example 1 was applied to a colored coating (A-
3) is applied to a film thickness of 50 μm and left at room temperature for 3 minutes, and then metallic paint (B-1) is applied to a film thickness of 13 μm.
And then leave it at room temperature for 3 minutes, then apply clear coating (C-1) to a film thickness of 40 μm, leave it at room temperature for 3 minutes, and then heat it at 140 ° C. for 30 minutes. The three layer coating was cured. Then, the clear coating film (D-1) was applied to the surface of the clear coating film so that the film thickness was 40 μm, left at room temperature for 3 minutes, and then heated at 140 ° C. for 30 minutes to cure.

The total film thickness of the coating film obtained by the 4-coat 2-bake coating method of this comparative example was 143 μm, which was a thick film. When the finished appearance was visually inspected, the colored coating film and the metallic coating film were mixed. However, the coating film was reversed, and the glittering feeling was inferior.

Comparative Example 3 The same coating material as in Example 1 was coated with a colored coating (A-
4) was applied to a film thickness of 35 μm and left at room temperature for 3 minutes, and then the metallic paint (B-1) was applied to a film thickness of 13 μm.
And then leave it at room temperature for 3 minutes, then apply clear coating (C-1) to a film thickness of 40 μm, leave it at room temperature for 3 minutes, and then heat it at 140 ° C. for 30 minutes. The three layer coating was cured. Then, the clear coating film (D-1) was applied to the surface of the clear coating film so that the film thickness was 40 μm, left at room temperature for 3 minutes, and then heated at 140 ° C. for 30 minutes to cure.

The total film thickness of the coating film obtained by the 4-coat 2-bake coating method of this comparative example was 128 μm, and the finish appearance was visually inspected to find that the colored coating film and the metallic coating film were mixed. However, the coating film was reversed, and the glittering feeling was inferior.

[0066]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location B05D 7/24 303 B05D 7/24 303C (72) Inventor Shigeru Nakamura Miyoshi-cho, Nishikamo-gun, Aichi Prefecture Kansai Paint Co., Ltd.

Claims (1)

[Claims] 1. A colored coating material (A), a metallic coating material (B) and a clear coating material (C) are sequentially applied to an object to be coated by wet-on-wetting, and then heated to simultaneously cure the coating films of the three layers. After that, the clear coating (D) is applied to the cured coating surface of the clear coating (C), and the coating composition is heated and cured to form a 4-coat 2-bake coating film forming method. Base resin, crosslinking agent, longitudinal average particle size 1
A thermosetting colored coating material containing a fine aluminum powder of 0 μm or less and a titanium oxide pigment, and a hiding power of a cured coating film of 25 μm or less, and the metallic coating material (B) is a base resin, a crosslinking agent and Comprising a metallic pigment having an average particle size in the longitudinal direction of 20 to 50 μm,
A method for forming a metallic coating film, which is a thermosetting metallic coating material in which the content of the pigment is 5 to 15 parts by weight per 100 parts by weight of the total amount of the base resin and the crosslinking agent.