JP2000005695A - Metallic finish method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the weatherability (resistance to color degradation) of a metallic coating film by applying a metallic coating liquid containing a metallic pigment consisting of a colored aluminum flakes whose surface is covered with a resin containing an ultraviolet absorbent or a photostabilizer and a clear coating liquid on an object to be coated such as a body outer plate. SOLUTION: A metallic coating liquid to be used is a metallic coating liquid containing a metallic pigment consisting of colored pigment-colored aluminum flakes whose surface is covered with a resin containing an ultraviolet absorbent or a photostabilizer. On the outer hand, a clear coating liquid is for example, composed mainly of a resin component and a solvent and is blended with a colored pigment or the like to such an extent that the feel of transparency of a coating film is not impaired, according to necessity. An object to be coated formed of metal or plastics such as a body outer plate is coated with the metallic coating liquid and the clear coating liquid in that order. After that, these coating films are metallic-finished using a 2-coat 1-bake process which crosslinks and cures the coating films simultaneously. Thus it is possible to obtain a metallic coating film whose sheen feel does not fade away on account of color degradation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallic paint containing a colored metallic pigment coated with a resin containing an ultraviolet absorber or a light stabilizer and a metallic finishing method for applying a clear paint.

[0002]

2. Description of the Related Art It is known that an aluminum flake-containing metallic paint and a clear paint are sequentially applied to an object to be coated such as an outer panel of an automobile body to form a metallic coating film. Form a coating film with excellent glitter. Aluminum flakes colored with a coloring pigment are described in, for example, JP-A-1-315470.
JP-A-9-40885, JP-A-9-59532
And Japanese Patent Application Laid-Open No. Hei 9-124973.

[0003] In order to improve the design of the metallic coating film, it is conceivable to use a metallic coating material containing the above-mentioned colored aluminum flakes. Has the defect that the color fades. To eliminate this defect,
Although it has been proposed to use a phthalocyanine-based pigment having excellent weather resistance as a pigment for coloring aluminum flakes, the color tone range of the metallic coating film is limited.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to improve the weather resistance (fading resistance) of a metallic coating film formed by applying a metallic paint containing a colored aluminum flake and a clear paint. As a result, the object was achieved by coating the surface of the colored aluminum flake with a resin containing an ultraviolet absorber or a light stabilizer.

That is, the present invention relates to a metallic paint (A) comprising a metallic pigment (A) in which the surface of an aluminum flake colored with a color pigment is coated with a resin containing an ultraviolet absorber or a light stabilizer. ) And a clear paint (B).

The method of the present invention will be described in detail.

Metallic paint (A) : clear paint (B)
This is a paint to be applied to an object to be coated prior to the coating of aluminum flakes. The surface of an aluminum flake ("colored aluminum") colored with a coloring pigment is coated with a resin containing an ultraviolet absorber or a light stabilizer. Metallic paint containing pigment ("resin-coated colored aluminum").

As an aluminum flake for preparing colored aluminum, for example, an average particle size of 1 to 200 μm, particularly 5 to 50 μm, a thickness of 0.1 to 5 μm, and a shape factor (average aspect ratio) obtained by dividing the average particle size by the thickness. Ratio) of about 5 to 100 is preferable. The aluminum flakes include those coated with a fatty acid such as oleic acid or stearic acid at the time of grinding.

As the coloring pigment for coloring the surface of the aluminum flake, organic pigments and inorganic pigments for paints can be applied, and there is no particular limitation. For example, diketopyrrolopyrrol-based, quinacridone-based, dioxazine-based, and Indolinone-based, condensed azo-based, sulene-based, perinone-based, piperine-based, phthalone-based, etc., phthalocyanine-based and phthalocyanine-based phthalocyanine-based resins having relatively excellent weather resistance, and carbon black , Titanium oxide, transparent iron oxide, mica, metal oxide-coated mica, and the like. The particle size of these color pigments is 0.01 to 1 μm.
m, particularly 0.02 to 0.1 μm, is used in an amount of 0.1 to 1 m ² of the surface area of the aluminum flake.
01 to 2 g, especially 0.03 to 0.5 g, is suitable.

[0010] The coloring of the aluminum flake surface with a coloring pigment can be carried out by a known method, and specific examples thereof include the following methods.

A: An aluminum flake and a coloring pigment are mixed and dispersed in an organic solvent solution of a resin, and the mixture is sprayed and dried to form a powdered colored aluminum flake.

B: a double bond and a carboxyl group formed by thermally polymerizing a carboxylic acid having a double bond (for example, higher unsaturated fatty acid such as linseed oil fatty acid or soybean oil fatty acid) on the surface of aluminum flake. A colored aluminum flake obtained by chemically adsorbing a coloring pigment via a compound having the following formula (see JP-A-1-315470).

C: 0.2 to 100 parts by weight of the coloring pigment
A colored aluminum flake obtained by adhering 0.01 to 0.5 g of a surface-treated coloring pigment coated with 100 parts by weight of a monobasic aromatic carboxylic acid per 1 m ² of the surface area of the aluminum flake. No. Hei 9-40885). Benzoic acid, aminobenzoic acid, aminohydroxybenzoic acid, naphthoic acid, as monobasic aromatic carboxylic acids
Amino naphthoic acid, cinnamic acid, amino cinnamic acid and the like can be used. Also included are aluminum flakes and titanium chelates attached to the surface of aluminum flakes together with a monobasic aromatic carboxylic acid.

D: Colored aluminum flakes obtained by depositing an organic color pigment on the surface of aluminum flakes (see JP-A-9-59532). Deposition amount of the organic coloring pigment is an aluminum frame - the surface area of the click 1 m ² per 0.
It is preferably from 0.5 to 0.5 g. In addition, those obtained by coating the deposited layer of the organic coloring pigment with a silane coupling agent or a titanium coupling agent are also included.

E: 0.2 to 100 parts by weight of the coloring pigment
A surface-treated coloring pigment coated with 100 parts by weight of an amino compound (having no carboxyl group) is used in an amount of 0.01 to 0.5 g per 1 m ² of the surface area of the aluminum flake.
Colored aluminum flakes adhered (Japanese Unexamined Patent Publication No.
No. 124973). C6 as amino compound
To 12 aliphatic diamines, N-β- (aminoethyl)-
γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane and the like can be used. Also, the method includes attaching an aluminum chelate or a titanium chelate to the surface of the aluminum flake together with the amino compound.

The resin-coated colored aluminum can be obtained by coating the above-mentioned colored aluminum with a resin containing an ultraviolet absorber or a light stabilizer.

As a method of coating the surface of the colored aluminum with these resins, for example, polymerizing a polymerizable monomer containing at least one selected from ultraviolet-absorbing polymerizable monomers and photostable polymerizable monomers. (A method), and a method of adding and mixing an ultraviolet absorber or a light stabilizer to the resin, and coating with the resin (Method B).

Method A : The surface of the colored aluminum is coated with a resin obtained by polymerizing one or more monomer components selected from ultraviolet-absorbing polymerizable monomers and light-stable polymerizable monomers. Is the way.

The UV-absorbing polymerizable monomer is a compound having at least one UV-absorbing functional group and at least one polymerizable double bond in the same molecule. For example, 2- (2
'-Hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazole and the like. The light-stable polymerizable monomer is a compound having one or more light-stable functional groups and one or more polymerizable double bonds in the same molecule. For example, 2,2,6,6-tetramethyl-4-
Piperidyl methacrylate and 1,2,2,6,6-
Pentamethyl-4-piperidyl methacrylate can be exemplified.

As the resin used in the method A, a polymer composed of only one or two or more monomers selected from the ultraviolet absorbing polymerizable monomer and the light-stable polymerizable monomer, or And copolymers obtained by using other polymerizable monomers in combination.

Other polymerizable monomers other than the above-mentioned UV-absorbing polymerizable monomer and light-stable polymerizable monomer, and further having one or more polymerizable double bonds in one molecule. For example, (meth) acrylic acid, itaconic acid, fumaric acid, maleic acid and carboxyl group-containing polymerizable monomers such as anhydrides and half-esterified products thereof; (meth) acrylic acid and monovalent alcohol Monoesterified product with (C1-24); (meth) acrylic acid and alkoxy (C1-20) monovalent alcohol-
Di, tri, and tetraesters of (meth) acrylic acid and a di- or higher-valent polyhydric alcohol having 2 to 10 carbon atoms; N, N-dimethylaminoethyl acrylate; N, N-dimethylaminoethyl methacrylate
N, N-diethylaminoethyl acrylate, N, N
N-diethylaminoethyl methacrylate, Nt-butylaminoethyl acrylate, Nt-butylaminoethyl methacrylate, N, N-dimethylaminopropyl acrylate, N, N-dimethyl Aminoacrylic monomers such as aminopropyl methacrylate; acrylamide, methacrylamide, N-methylacrylamide,
Acrylamide-based monomers such as N-methylmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-butylacrylamide, N-butylmethacrylamide, N-dimethylacrylamide, N-dimethylmethacrylamide; And glycidyl group-containing monomers such as glycidyl methacrylate;
Styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl acetate, vinyl chloride and the like can be mentioned.

As the resin for coating the surface of the colored aluminum in the method A, a) a polymer composed of only an ultraviolet-absorbing polymerizable monomer, b) a polymer composed of only a light-stable polymerizable monomer, and c) ultraviolet absorption A polymer obtained by using a polymerizable monomer and a light-stable polymerizable monomer in combination, and d) these a), b) and c) as well as other polymerizable monomers.
And the like.

Among them, the ratio of the UV-absorbing polymerizable monomer to the light-stable polymerizable monomer in c) is 1 to 90%, especially 1%, based on the total weight of both monomers.
0-80%, the latter is 99-10%, especially 90-20% is suitable. Further, the proportion of other polymerizable monomers in d) is suitably 90% or less, especially 70% or less based on the total weight of all monomers.

The polymerization of the monomers for preparing the above-mentioned polymers a) to d) can be carried out by a method known per se, and the number average molecular weight of the obtained polymer is about 2,000 to about 3
000000, especially 10,000 to about 100,000 are suitable.

As a method of coating the surface of the colored aluminum with these resins, for example, i) the above monomer component is added to a dispersion of the colored aluminum in an organic solvent, and the mixture is polymerized with stirring to form a coating on the surface of the flake. To precipitate a polymer of
i) Preparing a polymer in advance and coating by dispersing colored aluminum in an organic solvent solution. The amount of the resin (polymer) to be coated is suitably from 0.5 to 40 parts by weight, particularly from 5 to 20 parts by weight, per 100 parts by weight of the colored aluminum.

Method B : A method of coating the surface of colored aluminum with a resin mixed with an ultraviolet absorber and / or a light stabilizer.

Known UV absorbers or light stabilizers can be used, for example, benzophenone, 2,4-
Dihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-
Methoxybenzophenone, 2,2'-dihydroxy-
4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-
4-dodecyloxybenzophenone, 2-hydroxy-4
-Methoxy-5-sulfobenzophenone, 5-chloro-
2-hydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4- (2-hydroxy-3 Benzophenones such as -methylacryloxy) propoxybenzophenone; 2- (2'-hydroxy-
5'-methyl-phenyl) benzotriazole, 2-
(2'-hydroxy-3 ', 5'-di-tert-butyl-phenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methyl-phenyl) benzotriazo- 2- (2'-hydroxy-3 ', 5'-di-tert-butyl-phenyl) -5
-Chlorobenzotriazole, 2 (2'-hydroxy-
3 ', 5'-Di-tert-isoamyl phenyl)
Benzotriazoles such as benzotriazole and 2- (hydroxy-5-tert-butyl-phenyl) benzotriazole; ethyl-2-cyano-3,3'-
Acrylates such as diphenyl acrylate, 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate; hydroxy-5-methoxy-acetophenone, 2-hydroxy-naphthophenone, 2-ethoxy -Para-methoxycinnamate, nickel-bisoctylphenyl sulfide, [2,2'-thiobis (4-
t-octylphenolite)]-n-butylamine-nickel and the like, and these compounds can be used alone or in combination of two or more.

As the resin into which these ultraviolet absorbers or light stabilizers are mixed, the polymerizable monomers described in the above method A (however, a polymerizable monomer having an ultraviolet absorbing functional group and a light stable functional group) are used. Polymerizable monomer having
) Polymers, polyester resins, alkyd resins,
Urethane resin and the like. The number average molecular weight of these resins is from about 2000 to about 3,000,000, especially 1000
A range from 0 to about 100,000 is suitable.

The compounding amount of the ultraviolet absorber or light stabilizer is
1 to 90 parts by weight per 100 parts by weight of resin (solid content),
Particularly, a range of 10 to 50 parts by weight is suitable. The amount of the resin (including an ultraviolet absorber or a light stabilizer) that coats the colored aluminum is 0.1 to 100 parts by weight of the colored aluminum.
5 to 40 parts by weight, especially 5 to 20 parts by weight (solid content) are suitable.

In the method B, as a method of coating the surface of the colored aluminum with a resin mixed with an ultraviolet absorber or a light stabilizer, for example, an ultraviolet absorber or a light stabilizer is added to an organic solvent dispersion of the colored aluminum. Is added and polymerized with stirring to synthesize a resin, whereby a resin containing an ultraviolet absorber or a light stabilizer can be precipitated on the surface of the colored aluminum. Alternatively, the method can be carried out by preparing a resin solution in which an ultraviolet absorber or a light stabilizer is mixed, and dispersing colored aluminum in the resin solution.

The resin-coated colored aluminum prepared by the method A and the method B is dispersed in an organic solvent or a resin solution. However, the resin-coated colored aluminum is dispersed in an organic solvent or the like to form a paste. You can also.

The metallic paint (A) can be prepared by mixing and dispersing the resin-coated colored aluminum in a solvent (organic solvent or water) together with the thermosetting resin composition.

Examples of the thermosetting resin composition include an acrylic resin, a polyester resin, an alkyd resin, a polyurethane resin, a cellulose acetate butyrate resin having a crosslinkable functional group such as a hydroxyl group, a melamine resin and a (block) polyisocyanate. And a composition comprising a crosslinking agent such as a compound. The amount of the resin-coated colored aluminum is suitably in the range of 1 to 50 parts by weight, particularly 3 to 20 parts by weight, per 100 parts by weight (solid content) of the thermosetting resin composition.

The metallic paint (A) may optionally contain a coloring pigment, a metallic pigment, a light interference pigment, a pigment dispersant, an antifoaming agent, an anti-settling agent, a curing catalyst, and the like, as necessary.

It is preferable that the coating film of the metallic paint (A) is colored with colored aluminum and has a glittering brilliant feeling, and it is not possible to see through the bare ground.

The metallic paint (A) is prepared by mixing and dispersing the above components in a solvent such as an organic solvent or water, and has a solid content of 20 to 60% by weight, preferably 25 to 50% by weight at the time of coating. %, The viscosity is 10-30.
It is preferred that the temperature be adjusted to sec / ford cup # 4/20 ° C.

The metallic paint (A) may be applied directly to a metal or plastic object such as an outer panel of a car body, but usually, an undercoat paint (for example, It is preferable to apply a cationic electrodeposition coating), an intermediate coating (optional), or the like in advance and apply it to a cured object.

The metallic paint (A) can be applied by a method such as electrostatic coating, air spray, airless spray, etc., and its film thickness is 10 to 40 μm based on the cured coating film.
Is preferred. This coating film can be cross-linked and cured at a temperature of about 100 to about 170 ° C., and in the method of the present invention, after being cross-linked and cured, or without being cross-linked and cured without being cross-linked, the clear paint (B) described below. To paint.

Clear paint (B) : metallic paint (A)
This is a paint to be applied to the uncured or cured coating surface, mainly composed of a resin component and a solvent, and if necessary, a coloring pigment and other paint additives to such an extent that the transparency of the coating film is not impaired. It is a liquid paint which forms a colorless or colored transparent coating film by blending the above.

The resin component is preferably a thermosetting resin composition. Specifically, a base resin such as an acrylic resin, a polyester resin, an alkyd resin, or a urethane resin having a crosslinkable functional group such as a hydroxyl group, a carboxyl group, or an epoxy group is used. ,
Melamine resins, urea resins, polyisocyanate compounds (including block bodies), carboxyl group-containing compounds (or resins), epoxy group-containing compounds (or resins), and the like, are used in combination with crosslinking agents. Can use an organic solvent and / or water.

The clear paint (B) can be applied by a method such as electrostatic coating, air spray, or airless spray, and its film thickness is in the range of 10 to 100 μm based on the cured coating film. Is preferred. The clear coating (B) coating itself can be cross-linked and cured at a temperature of about 100 to about 170C.

According to the method of the present invention, an object to be coated such as a metal or plastic, such as an automobile outer panel, is directly applied, or an undercoat (eg, a cationic electrodeposition paint) or an intermediate coat (optional) is applied in advance. A metallic coating material (A) is applied to the cured object by electrostatic coating, air spray, airless spray, or the like to a thickness of 10 to 40 μm based on the cured coating film, and is applied to a thickness of about 100 to about 170. C to be cured by heating to a temperature of
The clear paint (B) is applied to the painted surface. The clear paint (B) is applied to the coated surface of the metallic paint (A) by electrostatic coating, air spray, airless spray or the like. The thickness is preferably in the range of 10 to 40 μm based on the cured coating film. Then, at a temperature of about 100 to about 170 ° C., 10 to 40
The metallic coating film according to the present invention can be formed by heating and curing these coating films for about a minute. That is, the method of the present invention can be achieved by applying the metallic paint (A) and the clear paint (B) by a two-coat two-bake system (2C2B) and a two-coat one-bake system (2C1B).

[0043]

[Effect of the Invention] A metallic coating film obtained by sequentially applying a metallic coating material containing resin-coated colored aluminum and a clear coating material has a colored glitter, has excellent design, and can be left outdoors for a long period of time. Almost no fading of the colored glitter is recognized.

[0044]

EXAMPLES Examples and comparative examples of the present invention will be described. Parts and% are based on weight in principle,
The film thickness of the coating film is for the cured coating film.

1. Sample 1) Coated object Degreasing and zinc phosphate treated steel sheet (JIS G314
1. Cationic electrodeposition paint (“ELECRON 9400HB”, manufactured by Kansai Paint Co., Ltd., trade name, epoxy resin polyamine-based cationic resin as a curing agent for block size isocyanate compound on 400 × 300 × 0.8 mm size) Is applied by a conventional method so as to have a film thickness of 20 μm (as a cured coating film), and is heated at 170 ° C. for 20 minutes for crosslinking and curing. ("LuGabeque middle coating gray", Kansai Paint Co., Ltd.)
(Trade name, polyester resin / melamine resin type, organic solvent type) was applied so as to have a thickness of 30 μm (as a cured coating film), and was heated at 140 ° C. for 30 minutes to be crosslinked and cured.

2) Metallic paint (A) (A-1): 400 parts of mineral spirits, 140 parts of aluminum flake (trade name, "Aluminum Paste 725N", manufactured by Showa Aluminum Co., Ltd.) (85% of metallic aluminum), 2.4 parts of a carboxylic acid having a double bond (“Harima Kasei Kogyo Co., Ltd.,“ Diacid ”)” obtained by thermally polymerizing acrylic acid and soybean oil fatty acid were added, and nitrogen gas was introduced thereinto.
After stirring for 1 hour while maintaining the temperature of ° C, the mixture was cooled to room temperature and filtered to obtain a thermally polymerized carboxylic acid-treated aluminum flake. On the other hand, in a pot mill, 30 parts of mineral spirit, 24 parts of a red pigment (manufactured by Dainippon Ink and Chemicals, Inc., "Color Fine Red 236A") and a pigment dispersant (manufactured by Kao Corporation, "Homogenol L-100")
0.48 parts were added, and the pigment was dispersed and pulverized.

Then, per 1 m ² of the surface area of the aluminum flakes treated with the thermally polymerized carboxylic acid, 0.2 parts by weight of the dispersed and pulverized coloring pigment was mixed with mineral spirit, and the mixture was introduced at room temperature for 10 minutes while introducing nitrogen gas. With vigorous stirring, a red aluminum flake pigment was obtained in which the coloring pigment was adsorbed on the surface of the thermally polymerized carboxylic acid.

150 parts (solid content) of the red aluminum flake pigment thus obtained was placed in a flask containing 1600 parts of mineral spirit without removing the mineral spirit, and 3 parts of acrylic acid was added.
For 15 minutes and then 6 parts of trimethylolpropane trimethacrylate, 2- (2'-hydroxy-5'-
(Methacryloxyethylphenyl) -2H-benzotriazole (ultraviolet absorbing polymerizable monomer) 12 parts, 2,
12 parts of 2,6,6-tetramethyl-4-piperidyl methacrylate (photostable polymerizable monomer) and 4.2 parts of azobisisobutyronitrile were added to 170 parts and 150 parts of mineral spirit, respectively. The dissolved product was added and the temperature was raised to 100 ° C. over 3 hours to carry out polymerization to coat the surface of the red aluminum flake pigment with a resin. This was filtered to remove excess mineral spirits.

A hydroxyl-containing acrylic resin (having a hydroxyl value of 80,
70 parts of acid value 7, number average molecular weight 12000), 30 parts of butylated melamine resin, 15 parts of the above resin-coated red aluminum flake pigment, and 2 parts of carbon black in an organic solvent (toluene / xylene = 1/1) (Weight ratio) and adjusted to a viscosity of 15 seconds (for ford cup # 4/20 ° C.) to obtain a metallic paint. The undercoat concealment film thickness of a single coating film of this paint is 10 μm. (A-2): Pyrrolopyrrole-based red pigment (IRGAZIN DPP, manufactured by Nippon Ciba Geigy Co., Ltd.)
To 1 g of RED B0), 0.5 part of benzoic acid and 10 g of mineral spirit were added, followed by ball mill dispersion in a pot mill for 24 hours. Then, an aluminum paste ("Miragro-100" manufactured by Toyo Aluminum Co., Ltd.) was added to the pot mill.
0 ", 11 parts (70% of metallic aluminum) and 20 parts of mineral spirit were added, and further ball-milled for 1 hour to obtain a slurry. This was washed out with 70 parts of mineral spirit to obtain an aluminum flake pigment colored red. Red pigment is aluminum frame
0.1 g per 1 m ² of the surface area of the steel.

Next, 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazo-per 10 parts of the colored aluminum flake pigment was used.
(UV absorbing polymerizable monomer) 0.25 parts, 2,
0.25 part of 2,6,6-tetramethyl-4-piperidyl methacrylate (photostable polymerizable monomer), 0.25 part of 1,6 hexanediol diacrylate, and 0.25 part of acrylic acid In addition, the mixture was heated to 80 ° C. with stirring, 0.05 parts of azobisisobutyronitrile was added as a polymerization initiator, and the mixture was reacted for 12 hours to polymerize these monomers. Was precipitated.

A hydroxyl group-containing acrylic resin (having a hydroxyl value of 80,
70 parts of acid value 7, number average molecular weight 12000), 30 parts of butylated melamine resin, 15 parts of the above resin-coated red aluminum flake pigment, and 2 parts of carbon black were mixed with an organic solvent (toluene / xylene = 1/1 weight). Ratio), and adjusted to a viscosity of 15 seconds (Food cup # 4/20 ° C.) to obtain a metallic paint. The undercoat concealment film thickness of a single coating film of this paint is 10 μm.

(A-3): Blue phthalocyanine pigment (manufactured by BASF, "Helio-Genbre-L6900")
After adding 10 g of mineral spirit to 1 g and dispersing uniformly, aluminum paste (manufactured by Toyo Aluminum Co., Ltd .;
11 mg of “MG1000”, average particle diameter 30 μm, thickness 1 μm, metal content 70%) and 20 g of mineral spirit were added, and further dispersed. The aluminum flake obtained by removing the solvent from the obtained dispersion is colored blue,
The blue pigment weighed 0.08 g per m ² of aluminum flake surface area.

0.25 g of 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazole (ultraviolet absorbing polymerizable monomer) per 10 g of this blue colored aluminum flake, 1,2,
0.25 g of 2,6,6-pentamethyl-4-piperidyl methacrylate (light-stable polymerizable monomer), 0.25 g of hexanediol diacrylate, 0.2 of acrylic acid
5 g are added and heated at 80 ° C. under nitrogen with stirring,
Azobisisobutyronitrile 0.05 as a polymerization initiator
Then, the monomers were polymerized by reacting for 12 hours and precipitated on the surface of the colored aluminum flake pigment.

A hydroxyl-containing acrylic resin (having a hydroxyl value of 80,
70 parts of acid value 7, number average molecular weight 12000), 30 parts of butylated melamine resin, 15 parts of the above resin-coated blue aluminum flake pigment, and 2 parts of carbon black in an organic solvent (toluene / xylene = 1/1 weight) Ratio), and adjusted to a viscosity of 15 seconds (Food cup # 4/20 ° C.) to obtain a metallic paint. The undercoat concealment film thickness of a single coating film of this paint is 10 μm.

(A-4): In (A-1), as a monomer component of a resin for coating the surface of the red aluminum flake pigment, "3 parts of acrylic acid, trimethylo-
Except for using “30 parts of propane trimethacrylate”, the surface of the red aluminum flake pigment was coated with a resin in the same manner as described in (A-1).

Using this red aluminum flake pigment, a metallic paint was obtained in the same manner as in (A-1).
(For Comparative Example) 6) Clear Paint (B) (B-1): "Lugabe Clear", manufactured by Kansai Paint Co., Ltd., trade name, acrylic resin / amino resin, organic solvent type.

2. Examples and Comparative Examples A metallic paint (A-
1) to (A-4) were formed using a REA gun to a film thickness of 15 to 1
The coating was performed so as to be 8 μm. After leaving at room temperature for 2 minutes, a clear paint (B) was applied to the uncured coating film surface to a film thickness of 35 μm using a mini-bell type rotary electrostatic coater.
After leaving it indoors for 3 minutes, it was heated in a hot air circulating drying oven at 140 ° C. for 30 minutes to simultaneously crosslink and cure these two layers of coating films. These coating processes are as shown in Table 1.

[0058]

[Table 1]

3. Performance Test Results Performance tests were performed on the multilayer coating films of the coated steel sheets obtained in Examples and Comparative Examples, and the results are also shown in Table 1.

The test was performed for accelerated weathering. Specifically, these coated steel sheets were exposed to a sunshine weatherometer for 400 hours, 800 hours, and 1200 hours, and the color difference ΔE between before and after the exposure was determined based on JISZ8730 for each coated surface. I asked. ΔE
The smaller the value, the smaller the discoloration due to the radiation and the better the weather resistance.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09C 1/64 C09C 1/64 3/10 3/10 F term (Reference) 4D075 AE03 AE10 AE12 BB26Z CA32 CB13 DB01 DB02 DB31 DC12 EA05 EA19 EA43 EB07 EB22 EB32.

Claims (7)

[Claims] 1. A metallic paint (A) and a clear paint containing a metallic pigment obtained by coating the surface of an aluminum flake colored with a coloring pigment with a resin containing an ultraviolet absorber or a light stabilizer. A metallic finishing method characterized by painting (B). 2. The metallic finishing method according to claim 1, wherein the resin for coating the surface of the colored aluminum flake is a polymer containing a UV-absorbing polymerizable monomer or a photostable polymerizable monomer as a constituent. 3. The metallic finishing method according to claim 1, wherein the resin coating the colored aluminum flake surface is a resin obtained by mixing an ultraviolet absorber or a light stabilizer. 4. The ultraviolet-absorbing polymerizable monomer is 2- (2 ′)
-Hydroxy-5'-methacryloxyethylphenyl)
The metallic finishing method according to claim 2, which is -2H-benzotriazole. 5. The photo-stable polymerizable monomer is 2,2,6,6
3. At least one selected from tetramethyl-4-piperidyl methacrylate and 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate.
Metallic finishing method described in 1. 6. The metallic coating according to claim 1, wherein the metallic coating (A) and the clear coating (B) are applied sequentially and then heated to cross-link and cure the two-layer coating simultaneously. Finishing method. 7. The metallic finishing method according to claim 1, wherein the object to be coated is a metal or plastic outer plate of an automobile body.