JP2002254025A - Forming method for new design paint film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming method for new design paint film which has quality feeling like an agate or a jade and deep solid like paint color. SOLUTION: A forming method for paint film which paints metalic base paint with brilliant pigment, paints white clear paint on it by wet-on-wet method, and after that, forms compound paint film by heating them. This method features that metallic base paint contains aluminum brilliant pigment having an average particle diameter (D5) 4.8-7.0 μm and aspect ratio 1-50, and titanium like white pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a composite coating consisting of a metallic base coating / clear coating as a surface finish coating on an automobile body and parts thereof.

[0002]

2. Description of the Related Art In general, the surface (1) of an automobile body or a component is
As shown in Fig. 1, an undercoating film having corrosion resistance and weather resistance
After being coated with (2) or the intermediate coating film (3), a top coating film (10) is formed thereon for the purpose of protecting the surface and imparting cosmetics. The top coat (10) is usually composed of a base coat (11) having a main color-forming function and a clear coat (1) for protecting the base coat (11).
It consists of 2). The base coating films are broadly classified into solid color base coating films having no shading or glittering appearance, and metallic color base coating films having glitter such as metallic luster.

[0003] Here, the glitter or the glitter is generally defined by measuring a flip-flop value (FF value) and an L value. The solid color base coating film usually has an FF value of 1 or less, and the F of the metallic color base coating film.
The F value is 8 to 10 or more. However, this FF value may be exceptionally high in matte black coatings (FF value 11.0) and metallic black coatings (FF value 12.0). Therefore, the L value is also measured together with the FF value in order to accurately know the glittering appearance or the glitter. L
The value is a measure that generally represents whiteness, and can be used as an auxiliary measure of the FF value because no exceptions appear in the color of the coating film, particularly in a black coating film.

[0004] In order to impart a high glitter to the metallic color base coating, glittering pigments such as flaky aluminum pigments and mica pigments are blended in addition to the coloring pigments and extenders used for the solid color coatings. Have been. The scaly shape means a thin metal piece. By blending an aluminum pigment having such a shape into a coating film, it is easy to orient in a planar shape, and a glittering luster can be imparted.

[0005] Recently, automobile bodies intended for the purchase of young women are lighter than conventional metallic colors.
In some cases, a so-called pastel metallic-like coating film having a soft color and not much glittering (FF value of 4 or 5 or more) is applied to an automobile body. Such a color tone can be obtained by combining a light metallic base film with a slightly colored clear paint film of the same color, or by overlaying a light solid color base paint film and a light metallic base film and then forming a clear paint film. Are obtained. The slightly colored clear coating film is also called a cloudy clear coating film, and imparts softness and depth to the composite coating film by forming on the base coating film. However, there is no known method for forming a coating film having a less brilliant feeling and a softer and deeper color than such a pastel metallic coating film.

[0006]

As described above, various types of coating films having a metallic luster and a light pastel-like brilliant coating film having a glittering appearance, starting with a solid coating film having no shading, have already been proposed. Are being considered and adopted.
However, although the FF value is higher than that of the solid color, it is not so glittery, glossy but not metallic, and a coating film having a deep and soft color tone is not yet known.

[0007]

Means for Solving the Problems The present inventors have found that a known light metallic paint color can be obtained by blending a combination of an aluminum-based brilliant pigment having a specific size and a titanium-based white pigment in a metallic base coating film. It has been found that it has a medium brightness of solid color, is milky white, and has a texture like agate and jade. In particular, it has been found that by using an aluminum-based brilliant pigment having a smaller average particle size and aspect ratio than those conventionally used, the glittering appearance is reduced and a deeper color is given to the coating color. Was. That is, the present invention applies a metallic base paint containing a brilliant pigment, applies a clear white opaque paint thereon in a wet-on-wet manner, and then heats them to form a composite coating film. A coating film forming method, wherein the metallic base paint is
Average particle size (D50) of brilliant pigment: 4.8 to 7.0 µm
And a titanium-based white pigment in combination with an aluminum-based brilliant pigment having an aspect ratio of 1 to 50. The clear white opaque paint used in the present invention is characterized by containing a titanium-based white pigment.

[0008]

DETAILED DESCRIPTION OF THE INVENTION metallic base coating metallic base coating is mainly the combination of the aluminum-based luster pigment and the titanium-based white pigment, and contains a film-forming resin and a curing agent, optionally Pigments other than the above and various additives are added. The metallic base paint suitably used in the present invention basically contains a combination of an aluminum-based brilliant pigment and a titanium-based white pigment.

The aluminum-based brilliant pigment has an average particle size (D50) of 4.8 to 7.0 μm, preferably 6 to 7 μm, and an aspect ratio of 1 to 50, preferably 10 to 40. This is a conventional one (for example, an average particle diameter (D50) of 15 to 25 μm, an aspect ratio of 60 to 1).
As compared with 10), the flip-flop value of the coating film can be reduced, and softness and deep glitter can be imparted.

An aluminum-based brilliant pigment having such dimensions is, for example, available from Toyo Aluminum Co., Ltd. under the trade name "Alpaste 96-0635" (average particle diameter (D50)).
6.7 μm and an aspect ratio of 38.5).

Examples of the titanium-based white pigment include titanium dioxide (for example, product name “CR-9” manufactured by Ishihara Sangyo Co., Ltd.).
7 "," CR-95 "," R-820 ", DuPont
“R-900” manufactured by Carmagee, “CR-88” manufactured by Carmagee
8 ") is used.

By using a titanium-based white pigment in combination with the aluminum-based brilliant pigment, it has a known light metallic paint color and a medium luminosity of a solid color, and has a hue like agate and jade. The unique texture of is brought. If it contains only the aluminum-based brilliant pigment and does not contain the titanium-based white pigment, it becomes a metallic coating film from green to dark red, and does not exhibit the above texture.

In the present invention, the aluminum-based brilliant pigment in the metallic base coating composition has a pigment weight concentration (PWC) of 1 to 3.
20% by weight, preferably 3 to 10% by weight, and 5 to 15% by weight of PWC, preferably 7 to
Each is contained at 12% by weight. Particularly, the weight ratio of the aluminum-based glitter pigment to the titanium-based white pigment is 1: 3.
１1: 1. When the PWC of the aluminum-based brilliant pigment is less than 1% by weight, a deep feeling and softness cannot be obtained in the coating color, and when the PWC exceeds 20% by weight, the glittering appearance is enhanced. The value is out of the range (0.3 to 4.5). If the titanium-based white pigment is added in an amount outside the above-mentioned PWC range, the agate or jade-like texture characteristic of the present invention cannot be obtained.

[0014] Metallic base paints include, in addition to the above-mentioned aluminum glitter pigments and titanium white pigments, organic azo chelate pigments, insoluble azo pigments, condensed azo pigments, diketopyrrolopyrrole pigments, benzimidazolones. It may contain an organic coloring pigment such as a pigment, a phthalocyanine pigment, an indigo pigment, a perinone pigment, a perylene pigment, a dioxane pigment, a quinacridone pigment, an isoindolinone pigment, and a metal complex pigment. In addition, the metallic base coating, if necessary, graphite,
Addition of inorganic coloring pigments such as yellow iron oxide, red iron oxide, carbon black, titanium dioxide, etc., and even a small amount of extender pigments (calcium carbonate, barium sulfate, clay, talc, etc.) and flat bright pigments such as mica powder Good.

The total amount of all organic coloring pigments in the metallic base paint is 1 to 20% by weight, preferably 2 to 10% by weight.
Is added in an amount of When the PWC exceeds 20% by weight, the appearance of the coating film is deteriorated. When the PWC of the all-organic coloring pigment is out of the above range, a pastel soft and deep color coating film cannot be formed.

Further, the PWC of all the pigments in the metallic base paint (that is, the total of the aluminum-based glittering pigment and the titanium-based white pigment, and the organic and inorganic coloring pigments, extender pigments and flat glittering pigments) is 1 -40% by weight, preferably 5-20% by weight. PWC of all pigments
Exceeds 40% by weight, both the adhesion of the coating film and the appearance of the coating film decrease.

The film-forming resin contained in the film-forming resin and the curing agent metallic base paint is not particularly limited as long as it is a commonly used film-forming resin. For example, acrylic resin, polyester resin ,
Alkyd resins, polyether resins, polyolefin resins, urethane resins and the like can be mentioned, and these can be used alone or in combination of two or more.

In particular, it is preferable to use an acrylic resin and / or a polyester resin from the viewpoint of weather resistance and water resistance.

The number average molecular weight of the film-forming resin (by GPC using styrene polymer as a standard) is 500
It is from 0 to 30,000, preferably from 7,000 to 25,000. If the number average molecular weight is less than 5,000, sufficient workability and curability cannot be obtained, and if it exceeds 30,000, the non-volatile content at the time of coating becomes too small, and the workability is reduced.

The film-forming resin has a hydroxyl value of from 20 to 180.
mgKOH / g (solid content), preferably 30 to 160 m
gKOH / g (solid content). When the hydroxyl value exceeds the upper limit, the water resistance of the coating film decreases, and when the hydroxyl value falls below the lower limit, the curability of the coating film decreases. In addition, the film-forming resin is 2 to 30 mg.
KOH / g (solid content), preferably 3 to 25 mg KOH
/ G (solid content). Regarding the acid value, as in the case of the hydroxyl value, if it exceeds the upper limit, the water resistance of the coating film decreases, and if it falls below the lower limit, the curability of the coating film decreases.

The film-forming resin is contained in the metallic base paint in an amount of 60 to 90 parts by weight, preferably 70 to 85 parts by weight.

Examples of the curing agent used in combination with the film-forming resin include an amino resin, a blocked isocyanate compound, an epoxy compound, an aziridine compound, a carbodiimide compound, and an oxazoline compound. From the viewpoints of various performances and costs, amino resins and / or blocked isocyanate compounds are preferably used.

The amino resin suitably used is not particularly limited, and examples thereof include benzoguanamine and melamine resins. On the other hand, examples of the blocked isocyanate include trimethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, or a blocking agent having active hydrogen in a polyisocyanate such as an isocyanate obtained by reacting these isocyanates with a compound having active hydrogen. Those obtained by the addition, and those which can be cured by reacting with the functional group in the resin component by generating a isocyanate group by dissociation of the blocking agent by heating.

In the metallic base paint, a curing agent is used in an amount of 20 to 10 parts by weight based on 100 parts by weight of the resin solid content of the film-forming resin.
It is used in an amount of 0% by weight. Hardener content in paint is 2
If the amount is less than 0% by weight, the curability becomes insufficient. If the amount exceeds 100% by weight, the cured film becomes too hard and brittle.

The metallic base paint may further contain various commonly used additives such as a viscosity control agent, a surface conditioner, an antioxidant and an antifoaming agent.

A metallic base paint is prepared by kneading or dispersing all of the above-mentioned compositions using a conventionally used apparatus and means such as a kneader or a roll.

According to the present invention, the metallic base paint is prepared at room temperature (20
C.) so that the coating viscosity at 10 ° C. becomes 10 to 30 seconds / # 4 Ford cup, preferably 10 to 18 seconds / # 4 Ford cup.

Clear Coating In the present invention, a clear coating exhibiting a light cloudy color is preferably used by containing 0.3 to 1.0% by weight of PWC containing a titanium-based white pigment. As the titanium-based white pigment used here, any of those described for the metallic base paint can be used.

The finely colored clear coating film is usually known as a turbid clear coating film, but in most cases a color similar to the color of the base coating film is employed. But,
In the present invention, the hue of the metallic base coating film applied under the cloudy clear coating film is not necessarily white as long as the combination of the above-mentioned glittering pigments is blended. A paint color other than white, such as green, blue, purple, or pink, is preferred. That is, in addition to the combination of the brilliant pigments, the desired coating color may be toned with a coloring pigment or an extender pigment.

The clear paint is an organic solvent type or an aqueous type (water-soluble, water-soluble) if it is a general overcoat clear paint containing, in addition to the pigment, a film-forming resin and a curing agent.
(Aqueous dispersibility, emulsion) and non-aqueous dispersion type.

The film-forming resin is not particularly limited, and acrylic resins, polyester resins, epoxy resins, urethane resins and the like can be used. These are compounded in combination with a curing agent such as an amino resin and / or a blocked isocyanate resin.

That is, as the organic solvent type clear paint, a combination of an acrylic resin and / or a polyester resin and an amino resin, or an acrylic resin having a carboxylic acid / epoxy curing system, in terms of transparency or acid etching resistance. And / or a combination of polyester resins is preferably used. In the case of an aqueous clear coating, a resin containing a resin obtained by neutralizing an acrylic resin and / or a polyester resin with a base and making the resin aqueous is used. The neutralization can be carried out before or after the polymerization, such as with diethylethanolamine and triethylamine.
This can be done by adding a secondary amine. Alternatively, in the case of a powder type clear coating material, a thermoplastic and thermosetting powder coating material may be used, and a thermosetting powder coating material is more preferably used because a coating film having good physical properties can be obtained. Among epoxy-based, acrylic-based, and polyester-based powder clear coatings, acrylic powder clear coatings are particularly preferably used because of their excellent weather resistance. Furthermore, epoxy-containing acrylic resin / polycarboxylic acid-based powder clear coating is most preferred because there is no volatile matter at the time of curing, a good coating appearance is obtained, and yellowing is small.

It is preferable that a viscosity control agent is added to such a clear paint in order to ensure coating workability. Further, various additives such as a curing catalyst and a surface conditioner may be added as necessary.

Such a clear paint is adjusted so that the solid content in the diluted paint at the time of application is 30 to 60% by weight, preferably 35 to 55% by weight. When the solid content of the diluted paint at the time of application exceeds 60% by weight, the appearance deteriorates, and when it is less than 30% by weight, the coating workability deteriorates.

The cloudy clear paint thus obtained has a coating viscosity at room temperature (20 ° C.) of 15 to 40 seconds / # 4 Ford cup, preferably 18 to 30, using a suitable diluent after preparation, if necessary. It can be adjusted to be 30 seconds / # 4 Ford Cup.

[0036] In the coating film formation method of a coating film forming method of the present invention, coating a metallic base paint object to be coated, after painted wet-on-wet method the white cloudy clear coating thereon, article to be coated Is heated to obtain a desired composite coating film.

The formed composite coating is a finish coating formed on the surface of the body and parts of vehicles such as passenger cars, trucks, motorcycles, and buses. Therefore, the object to be coated is
For example, metals such as iron, copper, aluminum, tin, zinc and the like and alloys containing these metals, glass, plastics, foams and castings may be used. When the object to be coated is a metal substrate, before the metallic composite coating film is formed,
It is preferable that the undercoat film and the intermediate coat film are formed beforehand by a chemical conversion treatment with a phosphate, a chromate salt, or the like. As the electrodeposition paint, a cationic type and an anion type can be used, but the cationic type electrodeposition paint gives a composite coating film having excellent corrosion protection. As the intermediate coating, a gray intermediate coating mainly using carbon black and titanium dioxide as main pigments is often used, but a so-called color intermediate coating in which various coloring pigments are combined may be used.

On the surface of the object to be coated, the metallic base paint is coated in a multi-stage manner by an electrostatic atomizing method such as an air atomizing method and / or a rotating atomizing method so as to obtain a uniform glitter. Preferably, the dry film thickness is 5 to 3 in 2 stages.
The paint is applied to a thickness of 5 μm, preferably 7 to 25 μm. For example, electrostatic air spray coating called "Auto REA", and rotary atomization type electrostatic coating called "μ (micro micro) bell", "micro (micro) bell" or "meta bell" etc. Can be used. When applying the metallic base coating composition by the air atomization type electrostatic air spray coating, the specific coating conditions include a discharge rate of 300 to 500 cc / min and an atomization air pressure of 2.
0-5.0 kg / cm ² , pattern air pressure 1.0-3.0.
0 kg / cm ² and an applied voltage of −90 to −60 kV. On the other hand, when using a rotary atomization type electrostatic coating machine, the coating conditions include, for example, a discharge amount of 200 to 350 cc.
/ Min, cone diameter 5-100mmφ, number of revolutions 10000
30,000 rpm, shaving air pressure 1.5-4.0
kg / cm 2 and an applied voltage of −90 to −50 kV.

The metallic base coating film can be cured by itself at a temperature of about 100 to 180 ° C.
After forming a clear coating on the metallic base coating by applying a clear coating on the metallic base coating to smooth and protect the coating surface unevenness and flicker caused by the glittering pigment in the metallic base coating, Simultaneously heat and cure.

The clear coating is preferably formed by using a rotary atomizing type electrostatic coating machine such as a μμ bell, μ bell, etc. described above, with a dry film thickness of about 10 to 80 μm, more preferably 20 μm.
It is painted so as to be about 60 μm.

After the application of the cloudy clear coating, the uncured metallic base coating and the clear coating are simultaneously heated and cured to form a composite coating (so-called two-coat one-bake method). The curing temperature is 80-180 ° C, preferably 12
Set to 0-160 ° C. By curing at a temperature in this range, a cured coating film having a high degree of crosslinking can be obtained. If the curing temperature exceeds 180 ° C., the coating film becomes hard and brittle, and if it is less than 80 ° C., the curing is not sufficient. The curing time varies depending on the curing temperature, but is suitably from 120 ° C to 160 ° C for 10 to 30 minutes.

The formed composite coating film has a total film thickness of 30 to 3
It is 00 μm, preferably 50 to 250 μm. If it exceeds the upper limit, the physical properties of the film such as a thermal cycle decrease, and if it falls below the lower limit, the strength of the film itself decreases.

The composite coating formed in the present invention has a flip-flop value of 0.3 to 4.5, preferably 1.0 to 4.0.
It is set between 0. As a result, a novel surface finish coating film having a solid design (poor luster) having a texture and depth similar to agate or jade can be obtained.

[0044]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to specific examples, but the present invention is not limited to the following examples. Parts and% mean parts by weight and% by weight, respectively, unless otherwise specified. Preparation nitrogen inlet tube of Example 1 acrylic resin, a stirrer, temperature controller, the reaction vessel 1L equipped with a dropping funnel and a cooling tube was charged with 80 parts of butyl acetate 20 parts of xylene, and the temperature of 120 ° C.. 5 parts of styrene, 30 parts of methyl methacrylate, 10.4 parts of 2-hydroxyethyl methacrylate, 44.4 parts of ethyl acrylate, 7 parts of ethyl methacrylate, 2.3 parts of methacrylic acid and 2 parts of t-butyl peroxy-2-hexanoate By mixing, a monomer solution was separately prepared. This monomer solution was added to the reaction vessel over 3 hours with stirring, and then stirring was continued for 1 hour. Thereby, the number average molecular weight is 21,000 and the hydroxyl value is 4
5 and an acid value of 15 mgKOH / g (solid content) were obtained.

Preparation of Metallic Base Coating A-1 An aluminum-based brilliant pigment (trade name "Alpaste 9" manufactured by Toyo Aluminum Co., Ltd.) was added to 56 parts of the acrylic resin.
6-0635 ", an average particle size (D50) of 6.7 [mu] m, an aspect ratio of 38.5) 5.2 parts, and a dispersion paste [titanium-based white pigment (trade name" CR-97 "manufactured by Ishihara Sangyo Co., Ltd.))
8.3 parts of which were previously dispersed with a pigment until the particle size became 5 μm or less]. There, butylated melamine resin (“Uban 20N60” manufactured by Mitsui Toatsu Co., Ltd., solid content 60
%) And 10 parts of crosslinkable resin particles (viscosity control agent manufactured by Nippon Paint Co., solid content 20%, solvent type; xylene, average particle size 55 nm by dynamic light scattering method) and further dispersed uniformly. As a result, a metallic base paint A-1 was obtained (organic solvent content: 64% by weight).

The obtained metallic base paint A-1 has
Toluene / ethyl acetate / butyl acetate = 5/2/3 so that the addition amount of ethylethoxypropionate is 8%.
The coating viscosity was adjusted to 12.5 seconds / # 4 Ford cup at 20 ° C. using a diluting solvent consisting of

Preparation of cloudy clear paint B-1 (melamine type) Acrylic-melamine curing clear paint "Olga TO-563 Clear" manufactured by Nippon Paint Co., Ltd. and titanium oxide pigment "CR-97" manufactured by Ishihara Sangyo Co., Ltd. Was added and dispersed until the particle size became 5 μm or less. In the obtained clear coating material B-1, the PWC of the titanium-based white pigment was 0.5% by weight.

The resulting clear coating was SW-1500.
(100%) 20 seconds / # 4 Ford cup at 20 ° C. using a diluting solvent composed of an aromatic organic solvent manufactured by Exxon
Was adjusted to the coating viscosity.

Table 1 summarizes the compositions used in the above-mentioned metallic base paints and clear paints and the amounts thereof.

[0050]

[Table 1]

[Table 2]

^* : Acrylic-melamine-curable clear coating ¹⁾ : Nippon Paint Co., Ltd. Aluminum-based brilliant pigment manufactured by Toyo Aluminum Co., Ltd., average particle size (D50) 6.7 μm, aspect ratio 3
8.5 ²⁾ : Titanium white pigment manufactured by Ishihara Sangyo Co., Ltd., average particle diameter (D50) 6.7 μm ³⁾ : Green pigment manufactured by Toyo Ink Co., Ltd. ⁴⁾ : Yellow pigment manufactured by Dainippon Ink Co., Ltd. ⁵⁾ : Yellow pigment manufactured by Bayer Corporation ⁶⁾ : Brown pigment manufactured by BASF Japan ⁷⁾ : Red pigment manufactured by Ciba Geigy ⁸⁾ : Butylated melamine resin manufactured by Mitsui Toatsu (solid content: 60)
%) ⁹⁾ : Viscosity control agent manufactured by Nippon Paint Co., solid content 20%, solvent type: xylene, average particle size 55 nm by dynamic light scattering method

Preparation of Test Coated Plate A test coated plate was prepared in the following procedure. Dull steel sheet with a thickness of 0.8 mm that has been subjected to zinc phosphate conversion treatment (dimensions: 20 × 3
(0 cm), a cationic electrodeposition paint ("Power Top V-20" manufactured by Nippon Paint Co., Ltd.) was electrodeposited so as to have a dry film thickness of 20 μm, and was cured by heating at 160 ° C. for 30 minutes (undercoat film). . Next, "Olga TO-8" is used as an intermediate coating.
70-gray "(polyester melamine paint manufactured by Nippon Paint Co., Ltd.) was applied by air spraying to a dry film thickness of about 20 μm, left at room temperature for 3 minutes and then at 140 ° C. for 30 minutes.
And then cured (intermediate coating film). On the intermediate coating film,
Apply the previously prepared metallic base paint in a dry film thickness of 15
The amount of paint applied was set to 290 (1 s) by "Metabell" (air electrostatic coating machine manufactured by Randsburg) so that the particle size became μm.
t. ) / 260 (2st.) Cc / min, air motor rotation speed 25000 rpm, shaving air pressure 500
NI, applied voltage -60kV, interval time 1.5
The coating was electrostatically applied by two-stage coating for 8 minutes, and after setting for 8 minutes, the clear white opaque coating prepared above was applied by hand spraying to a dry film thickness of 30 μm.
Then, after leaving it at room temperature for 7 minutes, the uncured metallic base coating film and the clear coating film are simultaneously cured by baking in a dryer at 140 ° C. for 30 minutes, and used for a test including the composite coating film of the present invention. A coated plate was obtained.

Evaluation Test Each test was carried out using the test coated plate according to the following procedure. (1) Measurement of flip-flop value and L value Using a variable-angle color difference meter (“CR354” manufactured by Minolta Co., Ltd.), the FF value and L value intensity at a position 45 degrees from the specularly reflected light were measured.

(2) Glitter The presence or absence of glitter (metallic feeling) was examined by visually observing the test coated plate.

(3) Depth The coated plate for the test was visually observed, and the presence or absence of texture such as agate or jade and texture such as glasswork was examined in accordance with the following evaluation criteria. Evaluation criteria: ：: good (all of the above textures are fully expressed) △: insufficient (one of the textures is insufficient) ×: poor (all of the textures are insufficient)

Table 2 summarizes the test results of the above (1) to (3).

Example 2 and Comparative Examples 1-3 Metallic base paints A-2 and A-2 were prepared in the same manner as in Example 1 except that the compositions and amounts shown in Table 1 were used.
-3 and clear paints B-2 and B-3 were prepared. These were used in accordance with Table 2, and in accordance with the same procedure as in Example 1, test coated plates were prepared, and then evaluation test (1)
To (4) were performed. Table 2 shows the results.

[0058]

[Table 3]

From the results shown in Table 2, it can be seen that good results were obtained in Examples 1 and 2 using the metallic base paint and the cloudy clear paint according to the present invention.

[0060]

According to the present invention, a combination of an aluminum-based brilliant pigment of a specific size and a titanium-based white pigment in a metallic base coating film reduces the glittering appearance, and more preferably, has no brilliant feeling. Gives depth to the paint color,
Thereby, an agate or jade-like texture can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a laminated coating film formed on a base steel sheet, including a composite coating film formed according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base steel plate, 2 ... Undercoat, 3 ... Intercoat, 10
... composite coating film (top coat film) of the present invention, 11 ... metallic color base coating film, 12 ... cloudy clear coating film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // C09D 5/29 C09D 5/29 201/00 201/00 F term (reference) 4D075 AE06 BB26Z CB13 DC11 EC11 4J038 CB001 CB002 CG141 CG142 DA111 DA112 DB001 DB002 DD001 DD002 DG031 DG032 DG301 DG302 DJ001 DJ002 GA03 GA06 HA066 HA166 KA08 MA12 MA14 PA19 PB07 PC02 PC03 PC08

Claims (4)

[Claims] 1. A metallic base paint containing a brilliant pigment is applied, and a clear white opaque paint is applied thereon by a wet-on-wet method, and then heated to form a composite coating film. A method for forming a coating film, wherein the metallic base paint has an average particle size (D5
0) A method for forming a coating film, comprising a combination of an aluminum-based brilliant pigment having a size of 4.8 to 7.0 μm and an aspect ratio of 1 to 50, and a titanium-based white pigment. 2. A metallic base paint comprising an aluminum-based glitter pigment and a titanium-based white pigment in a weight ratio of 1: 3 to 1: 2.
The method for forming a coating film according to claim 1, wherein 3. The composite coating film having a flip-flop value of 0.3.
The coating film forming method according to claim 1, wherein the number is from 4.5 to 4.5. 4. The method according to claim 1, wherein the clear paint contains a titanium-based white pigment at a pigment weight concentration of 0.3 to 1.0% by weight.