JP2002233815A - Method of forming photoluminescent coating film and coated material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a photoluminescent coating film, by which the coating film exhibiting high designable photoluminecent feeling such as starts twinkling in a dark night sky is formed, that is, a photoluminescent material in the photoluminescent material-containing clear coating film appears so as to be shone brightly without being buried in the base coating film, and a coated material. SOLUTION: The method of forming the photoluminescent coating film is performed by forming a color base coating film layer having a L value of 1-20 on the base material so be coated and after that, forming the photoluminescent clear coating film layer containing 0.001-0.1 mass% aluminum flake pigment, if necessary, an interfeerent mica pigment and/or a colored mica pigment in a dry coating film on the color base coating film layer and next, forming a top clear coating film layer on the photoluminescent clear coating film layer.

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 brilliant coating film and a coated article coated by the method.

[0002]

2. Description of the Related Art In a field requiring a high design such as an automobile body, a coating film using a brilliant paint containing a brilliant pigment is required. For example, Japanese Patent Application Laid-Open No. Hei 9-323064 discloses a method for forming a glittering coating film which is excellent in glittering glitter due to multi-directional reflection and shows a three-dimensional glitter.
(1) a step of forming a brilliant-containing base coating film on a substrate to be coated, and then (2) (A) an average particle diameter (D50) of 20 ±
5 μm, average particle thickness of 0.5 to 1.5 μm, rosin
An aluminum flake pigment having a gradient n of not less than 2.5 in a Ramler diagram or a synthetic mica powder pigment coated with a metal oxide (B) is a resin solid content of at least one brilliant.
It describes a step of forming at least one clear coating film containing a glittering material containing 0.005 to less than 0.1 part by weight based on 00 parts by weight.

However, according to the above publication, since the glittering material is contained in the base coating film, the appearance of the glittering material in the clear coating film is buried in the base coating film. The characteristics of the luminous material inside were buried, and the luster was like a star blinking in the Milky Way, and could not be said to be a highly designed luminosity like a star blinking in the dark night sky.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to make the appearance of a brilliant material in a brilliant clear coating film so that the brilliant material in the brilliant material-containing clear coating film is not buried in the base coating film. It is an object of the present invention to provide a method for forming a brilliant coating film and a coated article capable of forming a shining glittering coating film having a highly designable luminous feeling such as a twinkling star in a dark night sky.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned problems, and as a result, have reached the present invention. 1. After forming a color base coating layer having an L value of 1 to 20 on a substrate to be coated, the dried base coating contains 0.001 to 0.1% by mass of an aluminum flake pigment on the color base coating layer. A glittering coating film forming method, comprising forming a glittering clear coating layer, and then forming a top clear coating layer on the glittering clear coating layer. 2. The above glittering coating film forming method, wherein the L value of the color base coating film layer is 1 to 10. 3. The above method for forming a glitter coating film, wherein the glitter coating film layer contains the interference mica pigment and / or the colored mica pigment together with the aluminum flake pigment in an amount of 0.001 to 0.1% by mass in the dried coating film. 4. The above glittering coating film forming method, wherein the top clear coating layer is formed of a clear coating, and the clear coating is a coating containing a resin containing a carboxyl group-containing polymer and an epoxy group-containing polymer. 5. A coated article obtained by the above-described method for forming a glittering coating film.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.

In the method for forming a brilliant coating film of the present invention, the base material on which an electrodeposition coating film or an intermediate coating film has been formed is wet-on-wet (W / W W) or wet-on-dry (W / D) to form the color base coating layer. The above-mentioned W / W is a method in which a base coat is applied, then dried by air drying or the like, and applied to an uncured or semi-cured base coat. This is a method in which the film is baked and cured, and then applied to the undercoat film. In this way, after forming the color base coating layer, the further W / W or W
/ D, on the color base coating layer, containing the aluminum flake pigment, and optionally the interference mica pigment and / or the colored mica pigment to be incorporated as required, in the dried coating film in an amount of 0.001 to 0.1% by mass. To form a transparent clear coating layer. On the bright clear coating film layer thus formed, at least one top clear coating layer is formed as a top clear coating layer.

Substrate to be Coated The substrate to be coated is not limited, and metals such as iron, aluminum, copper and alloys thereof; inorganic materials such as glass, cement and concrete; polyethylene resin and polypropylene Resins, ethylene-vinyl acetate copolymer resin, polyamide resin, acrylic resin, vinylidene chloride resin, polycarbonate resin, polyurethane resin, epoxy resin and other resins, and various plastic materials such as FRP; wood, paper, cloth and other fibers Natural or synthetic materials such as materials. In the glitter coating film forming method of the present invention, a color base coating layer having an L value of 1 to 20 is formed on the substrate to be coated directly or via an undercoat coating film. In the case where the coating product obtained by the forming method is an automobile body and parts, it is preferable that the base material to be coated is previously subjected to undercoating such as degreasing treatment or chemical conversion treatment, electrodeposition coating, or intermediate coating. . The intermediate coating is performed for hiding the base, imparting chipping resistance, and ensuring adhesion with the top coat.

Formation of Color Base Coating Layer The color base coating layer in the glitter coating forming method of the present invention comprises a vehicle comprising a resin for forming a coating and, if necessary, a crosslinking agent, a coloring pigment, and, if necessary, a coloring pigment. It is formed from a color base paint containing a bright pigment. The color base paint can take various forms such as a solvent type, an aqueous type and a powder type obtained by dispersion. As the solvent-based paint or the water-based paint, a one-pack paint may be used, or a two-pack paint such as a two-pack urethane resin paint may be used. Such a paint may contain a curing catalyst, a surface conditioner, and other additives in addition to the above components. This color base coating layer is a coating layer that hides the underlying layer.

In the glittering coating film forming method of the present invention, the resin for forming a coating film contained in the color base coating material used for forming the color base coating film layer includes (a) an acrylic resin, (b) a polyester resin, (C) alkyd resin, (d) fluorine resin, (e) epoxy resin, (f) polyurethane resin, (g) polyether resin, and the like. These may be used alone or in combination of two or more. Preferably, it is an acrylic resin or a polyester resin.

The acrylic resin (a) includes a copolymer of an acrylic monomer and another ethylenically unsaturated monomer. Acrylic monomers that can be used in the above copolymerization include acrylic acid or methacrylic acid methyl, ethyl, propyl, n-butyl, i-butyl, t-butyl, 2-ethylhexyl, lauryl, phenyl, benzyl, 2-hydroxy Esterified compounds such as ethyl and 2-hydroxypropyl, ring-opened adducts of caprolactone of acrylic acid or 2-hydroxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide and N-
Methylol acrylamide, polyhydric alcohol (meth)
There are acrylic esters and the like. Other ethylenically unsaturated monomers copolymerizable therewith include styrene, α-methylstyrene, itaconic acid, maleic acid, vinyl acetate and the like.

Examples of the polyester resin (b) include saturated polyester resins and unsaturated polyester resins. Examples thereof include condensates obtained by heat-condensing a polybasic acid and a polyhydric alcohol. Examples of the polybasic acid include saturated polybasic acids such as phthalic anhydride, terephthalic acid, and succinic acid, and unsaturated polybasic acids such as maleic acid, maleic anhydride, and fumaric acid. Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol and diethylene glycol, and trihydric alcohols such as glycerin and trimethylolpropane. The resin for forming a coating film includes a curable type and a lacquer type, but a type having a curable type is usually used.

In the case of a type having curability, amino resins, (block) polyisocyanate compounds, amines, polyamides, imidazoles, imidazolines,
It is used by mixing with a crosslinking agent such as a polyvalent carboxylic acid, and the curing reaction can proceed at heating or at room temperature. Also,
Lacquer type coating film forming resin without curability,
It is also possible to use together with a type having curability.

When the vehicle contains a cross-linking agent, the ratio of the resin for forming a film to the cross-linking agent is 90 to 50% by weight and the content of the cross-linking agent is 10 to 50% by weight in terms of solid content. Preferably, the coating film forming resin is 85 to 60% by weight, and the crosslinking agent is 15 to 40% by weight. If the crosslinking agent is less than 10% by weight (the resin for forming a coating film exceeds 90% by weight), the crosslinking in the coating film is not sufficient. On the other hand, when the cross-linking agent exceeds 50% by weight (the resin for forming a coating film is 50% by weight)
), The storage stability of the coating material is reduced and the curing speed is increased, so that the appearance of the coating film is deteriorated.

As the color pigment contained in the color base paint, there may be mentioned organic pigments and inorganic pigments which have been conventionally used for paints. For example, organic pigments include azo lake pigments, phthalocyanine pigments, indigo pigments, perylene pigments, quinophthalone pigments,
Dioxazine pigments, quinacridone pigments, isoindolinone pigments, metal complex pigments and the like, and as the inorganic pigments, yellow iron oxide, red iron oxide, titanium dioxide,
And carbon black. On the other hand, as the glitter pigment contained in the color base paint, conventionally used for paints, for example, aluminum flake pigment, colored aluminum flake pigment, graphite pigment, mica pigment, metal titanium flake, stainless flake, plate Iron oxide, phthalocyanine flakes or metal-plated glass flakes.

In the above color base paint, the type and amount of the above color pigment and, if necessary, the glitter pigment are selected and added so that the L value of the coating film obtained therefrom is 1 to 20. When the L value exceeds 20, the aluminum flake pigment in the glitter clear coating film and the interference mica pigment and / or the colored mica pigment to be blended as necessary are embedded in the base coating film,
There is a possibility that the aluminum flake pigment and the interference mica pigment and / or the colored mica pigment to be blended if necessary may not exhibit a glittering shine. Preferred L values are 1 to
It is 10. Here, the L value means a lightness index in the Hunter's color difference formula obtained from the tristimulus values X, Y, Z specified in JIS Z28722.

[0017] The content of the above-mentioned coloring pigment and, if necessary, the glittering pigment (solids weight ratio of the pigment to 100 parts by weight of the paint solids: PWC) is preferably less than 50%, more preferably less than 30%. More preferred. If it exceeds 50%, the appearance of the coating film deteriorates. Talc, calcium carbonate,
Various extender pigments such as precipitated barium sulfate and silica can be used in combination.

In addition to the above-mentioned components, the above-mentioned color base paint comprises a polyamide wax which is a lubricating dispersion of an aliphatic amide, a polyethylene wax which is a colloidal dispersion mainly composed of polyethylene oxide, an anti-settling agent, a curing catalyst, an ultraviolet absorbing agent. Agents, antioxidants, leveling agents, surface conditioners such as silicone and organic polymers, anti-sagging agents, thickeners, defoamers, lubricants, cross-linkable polymer particles (microgels), etc., appropriately added and contained. be able to. The performance of paints and coatings can be improved by blending these additives in a proportion of, for example, 15 parts by weight or less with respect to 100 parts by weight of the vehicle (based on solid content).

When the above-mentioned color base paint is of a solvent type or an aqueous type, the above-mentioned components are usually provided in a form dissolved or dispersed in a solvent. Any solvent may be used as long as it dissolves or disperses the vehicle, and an organic solvent and, if necessary, water can be used. Examples of the organic solvent include those commonly used in the field of coatings.
Examples thereof include hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, cellosolve acetate and butyl cellosolve, and alcohols. When the use of an organic solvent is regulated from the viewpoint of the environment, it is preferable to use water. In this case, it may contain a suitable amount of hydrophilic organic solvent.

The dry film thickness of the color base coating layer is 1
0-100 μm is preferred. If it is less than 10 μm, it is difficult to hide the underlayer, and if it is more than 100 μm, the appearance of the coating film may be poor. More preferably, it is 20 to 50 μm.

The glittering clear coating layer in the glistening coating forming method of forming the present invention glittering clear coating layer, on top of the color base coating film layer, is blended as aluminum flake pigment, as well as necessary It is formed by a bright clear paint containing 0.001 to 0.1% by mass of an interference mica pigment and / or a colored mica pigment in a dry coating film.

The brilliant clear coating material can take various forms such as a solvent type, an aqueous type or a powder type.
As the solvent-based paint or the water-based paint, a one-pack paint may be used, or a two-pack paint such as a two-pack urethane resin paint may be used. The brilliant clear coating material may include aluminum flake pigments, and other brilliant pigments of a type and amount within a range that does not impair the effects of interference mica pigments and / or colored mica pigments that are optionally blended, and Color pigments can be included. The vehicle, other glitter pigments, coloring pigments, and other components contained in the glitter clear paint are the same as those described in the color base paint.

The aluminum flakes are obtained by converting aluminum commonly used as a glitter material of metallic paint into flakes and treating them with a fatty acid or the like. Depending on the orientation state in the coating film, leafing type or semi-leafing is used. Type or non-leafing type.
The average particle size is preferably 5 to 60 μm, more preferably 15 to 30 μm. When the average particle diameter is less than 5 μm, it is difficult to exhibit a glittering feeling, and when the average particle diameter is 60 μm or more, the appearance of the coating film may be poor. On the other hand, the thickness is 0.
It is 1 to 3 μm, preferably 0.2 to 1.5 μm. When the thickness is less than 0.2 μm, an excessive share is applied at the time of coating circulation, and the glittering pigment is deformed or broken to cause a problem that the coating is discolored with time.
If it exceeds m, the coating film appearance may be degraded.

The above-mentioned interference mica pigment, which is added to the composition as required, is a coating of a thin film of titanium dioxide or iron oxide on the surface of natural muscovite or synthetic mica, and is a pigment exhibiting a glittering feeling and an interference color. It is. Such an interference mica pigment has a particle size range of 1
A scaly one having a particle size of ６０60 μm, preferably 1-40 μm and an average particle size of 15-25 μm can be used.
The average particle size in the present invention means the average particle size of the major axis. In the interference mica pigment, a desired interference color can be obtained by adjusting the amount of titanium dioxide or iron oxide to be coated (coating thickness).

The colored mica pigment to be added to the compound as required is preferably a mica pigment obtained by coating a surface of natural muscovite or synthetic mica with a colored pigment in a flaky shape. Such a colored mica pigment has a particle size range of 1 to 60 μm, preferably 1 to 40 μm.
In this case, a scale-like material having an average particle size of 15 to 25 μm can be used. The color of the colored mica pigment can obtain a desired interference color by adjusting the type and amount (coating thickness) of the colored pigment to be coated.

The content of the above-mentioned aluminum flake pigment, the interference mica pigment and / or the colored mica pigment to be blended as required in the bright clear coating film may be either the aluminum flake pigment alone or the aluminum flake pigment. Even when the pigment is used in combination with an interference mica pigment and / or a colored mica pigment,
1 to 0.1% by mass, preferably 0.05 to 0.1% by mass.
% By mass. When the content is less than 0.001% by mass or more than 0.1% by mass, the aluminum flake pigment and the interference mica pigment and / or the colored mica pigment blended as required in the glittering material-containing clear coating film shine. In particular, it is not possible to obtain a high design sensation like a star blinking in a dark night sky.

When the aluminum flake pigment and the interference mica pigment and / or the colored mica pigment are used in combination, the solid content mixing ratio is: aluminum flake pigment / interference mica pigment and / or colored mica pigment = 95/5.
~ 50/50 is preferred. The dry film thickness of the bright clear coating layer is preferably 5 to 100 μm. If the thickness is less than 5 μm, a brilliant feeling with saturation cannot be sufficiently exhibited, and
If it exceeds 300, the appearance of the coating film may be insufficient. More preferably, it is 10 to 40 μm.

Formation of Top Clear Coating Layer In the method for forming a glitter coating film of the present invention, after forming a glitter clear coating layer, a top clear coating layer is formed thereon. The top clear coating layer in this case is a colorless and transparent clear coating that does not conceal the underlying layer, and may be a so-called color clear coating that imparts a translucency. By forming a top clear coating layer on the coating layer, it is possible to improve the gloss and prevent the above-mentioned aluminum flake pigment and the protrusion of the interference mica pigment and / or the colored mica pigment to be added as required. . The top clear coating layer is formed from a clear coating.Examples of the clear coating include those commonly used for overcoating, and the above-mentioned curable coating film forming resin and a crosslinking agent. Can be used.

These clear coatings may be used, if necessary,
As long as the transparency is not impaired, coloring pigments, extender pigments,
Additives such as a modifying agent, an ultraviolet absorber, a leveling agent, a dispersant, and an antifoaming agent can be blended. In addition, Tokuhei 8
When the clear paint containing a carboxyl group-containing polymer and an epoxy group-containing polymer described in JP-A--19315 is coated with the bright clear coating layer by acid rain and wet-on-wet, the aluminum flake pigment It is preferably used from the viewpoint of not disturbing the orientation of the interference mica pigment and / or the colored mica pigment to be blended as required. In addition, the top clear coating layer can take various forms such as a solvent type, an aqueous type, or a powder type. As the solvent-based paint or the water-based paint, a one-pack paint may be used, or a two-pack paint such as a two-pack urethane resin paint may be used.

The dry film thickness of the top clear coating layer is as follows:
It is preferably from 20 to 400 μm, and if it is out of this range, the appearance of the coating film may be insufficient. More preferably 30 to
200 μm.

The method for forming each coating layer is not particularly limited, but a spray method or a roll coater method is preferred for applying a solvent type paint or an aqueous paint, and an electrostatic coating is preferred for applying a powder paint. . As drying conditions, 80 to 16
It is baked at 0 ° C. for a predetermined time to obtain a coating film.

Coated Product The coated product of the present invention is obtained by the above-described method for forming a glittering coating film, and has a color base coating layer having an L value of 1 to 20,
A bright clear coating layer containing 0.001 to 0.1% by mass of the above-mentioned aluminum flake pigment, and optionally an interference mica pigment and / or a colored mica pigment, and then a top clear coating layer Is formed. In the coated product on which these multilayer coating films are formed, the appearance of the glittering material in the glittering clear coating film is not buried in the base coating film, and the glittering material in the glittering clear coating film is glittering. It has a highly luminous feeling, such as a twinkling star in the dark night sky.

[0033]

EXAMPLES Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, the compounding amount represents a weight part unless there is particular notice.

Examples 1 to 11 and Comparative Examples 1 to 2 Preparation of Coated Substrates Dull steel plates (length 300 mm, width 100 mm and thickness 0.8 mm) were degreased and then treated with a zinc phosphate treatment agent ("Surfdyne SD2000"). And Nippon Paint Co., Ltd., and then subjected to a chemical electrodeposition coating ("Power Top U-5").
0 ", manufactured by Nippon Paint Co., Ltd.) was electrodeposited so that the dry film thickness was 25 μm. Next, after baking at 160 ° C. for 30 minutes, a color base paint (“Olga S-90”, manufactured by Nippon Paint Co., Ltd.) toned so that the L value becomes the value shown in Table 1 is adjusted to a dry film thickness of 40 μm. And sprayed at 140 ° C. for 30 minutes to form a color base coating layer.

Preparation of glitter clear paint Acrylic resin (styrene / methyl methacrylate / ethyl methacrylate / hydroxyethyl methacrylate /
Methacrylic acid copolymer, number average molecular weight about 20,000,
A hydroxyl value of 45, an acid value of 15, and a solid content of 50% by weight, and a melamine resin (trade name, “Uban 20SE”, manufactured by Mitsui Chemicals, Inc., solid content of 60% by weight) are blended at a solids weight ratio of 80:20. Aluminum flake pigments and interference mica pigments and / or colored mica pigments, as required, were blended with the vehicle obtained in the types and ratios shown in Table 1. Subsequently, an organic solvent (weight ratio of toluene / xylene / ethyl acetate / butyl acetate = 70/15/1)
0/5) with a stirrer so as to obtain an appropriate viscosity for coating to prepare a bright clear paint.

Bright clear coating film and top clear
Formation of a coating film The glittering clear paint obtained above was spray-coated on the surface of the substrate on which the color base was formed so that the dry film thickness became 15 µm, to form a glittering clear coating film. Coating was performed using an electrostatic coating machine (“Auto REA”, manufactured by ABB Industries) at an atomization pressure of 2.8 kg / cm ² . The atmosphere of the booth during painting is temperature 25 ° C, humidity 75
%. Set for 3 minutes after painting, apply top clear paint so that dry film thickness is 35 μm,
Set at room temperature for 10 minutes and at 140 ° C for 30 minutes.
Baked for a minute to form a top clear coating. The glitter of the obtained multilayer coating film was evaluated by the following evaluation method. Table 1 shows the results. The clear paint used to form the top clear coating film is an acrylic / melamine resin clear paint 1
(Trade name: "Super Lac O-130 Clear", manufactured by Nippon Paint Co., Ltd.) or clear paint 2 containing a carboxyl group-containing polymer and an epoxy group-containing polymer
("Macflow O-520 Clear", manufactured by Nippon Paint Co., Ltd.). Table 1 shows the evaluation results.

Evaluation method Glitter: The appearance of the brilliant material in the brilliant clear coating film in the coated product obtained from the obtained multilayer coating film is not buried in the base coating film, but the brilliant material-containing clear coating film. It was visually evaluated whether or not the luminous material in the inside shines brilliantly, in particular, whether or not it exhibits a brilliant feeling like a twinkling star in a dark night sky. 3: The above-mentioned glitter is remarkable. 2: The above-mentioned glitter is temporarily recognized. 1 .... The above-mentioned glitter is not recognized.

[0038]

[Table 1]

As is clear from the results shown in Table 1, this example is a coated article obtained by the method for forming a glittering coating film of the present invention. The luminous material in the brilliant material-containing clear coating film shines without being buried in the film, and expresses a highly brilliant feeling such as a star blinking in a dark night sky. On the other hand, in the comparative example, since the glittering material in the glittering material-containing clear coating film is out of the range of the present invention, the glittering material in the clear coating film has high design sensation such as a star blinking in the dark night sky. The result was not obtained.

[0040]

According to the present invention, a color base coating layer having an L value of 1 to 20 is formed on a substrate to be coated, and then an aluminum flake pigment and, if necessary, mixed with the color base coating layer. Of the interference mica pigment and / or the colored mica pigment
By forming a glitter clear coating film layer containing the bright clear coating film containing by mass, and then forming a top clear coating film layer on the glitter clear coating film layer, the appearance of the glitter material in the glitter clear coating film becomes a base. Without being buried in the coating film, the glittering material in the glittering material-containing clear coating film can shine brilliantly, and it is possible to express a high design brilliant feeling, especially like a star blinking in the dark night sky, As a result, it has become possible to form a coating film that can provide a more luxurious glitter. In addition, since the coating film obtained by the present invention exhibits the above-mentioned brilliant feeling, it is preferably used in fields where brilliancy is required, such as a vehicle outer plate, an outer surface of a container such as an automobile and a motorcycle, a coil coating, and a home appliance industry.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4D075 AE06 AE15 CB13 DB02 DB06 DB07 DB12 DB13 DB18 DB20 DB21 DB36 DB38 DB47 DB48 DB50 DC12 EA43 EB16 EB22 EB33 EB35 EB36 EB37 EB38 EC04 EC10 EC23 EC54 4F100 AB03 AK01C12K AK12 AK25J AL01 AT00A BA04 BA07 BA10A BA10D CA13B CA13C CC00B CC00C CC01D DE02C EH46 EH462 EJ68 GB16 GB31 GB32 GB48 HB00 HB00B HB00C JL10B JL10C JN01C JN01D JN21 JN21C YY00B YY00C

Claims (5)

[Claims] After forming a color base coating layer having an L value of 1 to 20 on a substrate to be coated, the color base coating layer is
Aluminum flake pigment in 0.001
Forming a bright clear coating film layer containing 0.1% by mass,
Next, a glittering coating film forming method for forming a top clear coating layer on the glittering clear coating layer. 2. An L value of the color base coating layer is from 1 to 1.
The method for forming a glittering coating film according to claim 1, wherein the value is 0. 3. The dried clear coating film containing the interference mica pigment and / or the colored mica pigment together with the aluminum flake pigment in the glittering clear coating layer in an amount of 0.001 to 0.1% by mass. 3. The method for forming a glittering coating film according to item 2. 4. The method according to claim 1, wherein the top clear coating layer is formed of a clear paint, and the clear paint is a paint containing a resin containing a carboxyl group-containing polymer and an epoxy group-containing polymer. 3. The method for forming a glittering coating film according to the above item. 5. A coated article obtained by the method for forming a glittering coating film according to claim 1.