JP2001240808A - Metallic coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic coating composition suitable for forming a coating film having excellent metallic appearance (dense metallic feeling, intense brightness and high flip-flop property) and high adhesive force. SOLUTION: The objective metallic coating composition contains (A) a leafing type aluminum flake pigment, (B) a film-forming resin and (C) an organic solvent having a surface tension of >=34 dyn/cm2. The weight ratio of the leafing type aluminum flake pigment to the film-forming resin is 5/95 to 30/70 and the content of the organic solvent having a surface tension of >=34 dyn/cm2 in the diluted coating material is >=40 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stably forms a coating film having a fine metallic feeling, a high brilliancy, a high metallic effect such as a high flip-flop property, and a good adhesion. The present invention relates to a metallic coating composition suitable for:

[0002]

2. Description of the Related Art Heretofore, as a coating method for giving a glittering metallic feeling to a coating film, a thickness of 0.1 to 1 μm and an average particle size of 5 to 6 which have been pulverized by a ball mill together with a fatty acid.
A metallic paint containing 0 μm aluminum flake pigment is used.

[0003] Aluminum flake pigments to be blended with these metallic paints as brilliant materials are classified into non-leafing and leafing types according to their properties. Non-leafing type aluminum flake pigments are usually pulverized together with oleic acid, and when a metallic paint containing this brilliant is applied, the brilliant is irregularly dispersed inside the enamel coating film. Therefore, it is difficult to form a coating film having a high metallic sensation with high glitter and high flip-flop property. On the other hand, since leafing type aluminum flake pigments are pulverized together with stearic acid, their surface tension is low, and when a metallic paint containing this glittering material is applied, the glittering material floats on the upper surface of the enamel coating, Since it is oriented in parallel with the material, it has a high glitter and is suitable for forming a coating film having an excellent metallic feeling with a high flip-flop property. High flip-flop property means that the intensity of the reflected light at the highlight portion is high and the intensity of the diffuse reflected light at the shade portion is low.

However, the conventional coating composition containing a leafing type aluminum flake pigment as a glittering material has a problem in that cohesion and separation occur between the glittering materials floating on the upper surface of the enamel coating film, and the adhesion cannot be secured. Had. In addition, when the blending ratio of the leafing type aluminum flake pigment is reduced so as not to cause cohesive peeling, the leafing type aluminum flake pigment floating on the upper layer surface of the enamel coating film is reduced, and the glittering feeling is high, and a uniform metallic feeling is obtained. No coating film was obtained.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made of a metal having a fine metallic feeling, a high brilliancy and a high flip-flop property. An object of the present invention is to provide a coating composition suitable for stably forming a coating film having excellent feeling and good adhesion.

[0006]

The present invention relates to a leafing type aluminum flake pigment containing a leafing type aluminum flake pigment (A), a coating film forming resin (B), and an organic solvent (C) having a surface tension of 34 dyn / cm ² or more. An organic solvent (C) having a weight ratio of the flake pigment (A) to the film-forming resin (B) of 5:95 to 30:70 and a surface tension of 34 dyn / cm ² or more;
Is a metallic coating composition characterized by containing 40% by weight or more in a diluent coating material, so that the coating film has good adhesion and can stably form a coating film having an excellent metallic appearance. It was done.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The objects to be coated with the metallic coating composition of the present invention include metals including iron, aluminum, copper or alloys thereof, inorganic materials such as glass and concrete, polyethylene, polypropylene, and the like. Ethylene-vinyl acetate copolymer, polyamide, polyacryl,
Polyester, vinyl chloride resin, vinylidene chloride resin,
Polycarbonate, polyurethane, acrylonitrile
Examples include resin molded articles such as butadiene-styrene copolymers, plastic materials such as various FRPs, wood, and paper. These objects to be coated may be directly coated with the metallic coating composition of the present invention, or may be subjected to an appropriate undercoat or precoat treatment in advance. Further, the undercoat made of the thermosetting composition and the metallic coating composition of the present invention can be applied and cured by a wet-on-wet method.

As the leafing type aluminum flake pigment (A) used in the present invention, a normal leafing type aluminum flake pigment which is pulverized by a ball mill together with a fatty acid such as stearic acid can be used.
The leafing type aluminum flake pigment is preferably a leafing type aluminum pigment having a thickness of 0.1 to 1 μm and an average particle size in the longitudinal direction of 1 to 60 μm, particularly 1 to 20 μm. When the thickness is 1 μm or more or the average particle size in the longitudinal direction is 60 μm or more, the feeling of denseness of the coating film is inferior, which is not preferable.

As the film-forming resin (B) used in the present invention, any film-forming resin conventionally used for paints can be used without limitation. Examples of the main resin of the typical coating film forming resin include an acrylic resin, a polyester resin, an alkyd resin, a fluororesin, a silicone resin, and an epoxy resin. These can be used alone or in combination of two or more. Examples of the functional groups involved in crosslinking contained in these main resins include a hydroxyl group, a carboxyl group, an acid anhydride group, an epoxy group, and a silane group.

The film-forming resin (B) is usually used as a one-pack or two-pack type by mixing a main resin with a crosslinking agent such as a melamine resin or an isocyanate compound. Further, these crosslinking agents are not limited to one kind, and two or more kinds can be used in combination.

In the present invention, the weight ratio of the leafing type aluminum flake pigment (A) to the coating film forming resin (B) is 5
Pairs 95 to 30:70, especially 10:90 to 25:75 are preferred. When the blending amount of the leafing type aluminum flake pigment (A) is higher than 30 to 70, cohesive peeling of the enamel coating film easily occurs in the adhesion test. On the other hand, when the blending amount of the leafing type aluminum flake pigment (A) is less than 5:95, the glittering material floating on the upper layer surface of the enamel coating film is insufficient, so that the glittering feeling is poor and the glittering material is not oriented. Are likely to be present, and a coating film having a uniform metallic appearance cannot be stably formed.

The surface tension used in the present invention is 34 dyn /
The organic solvent (C) of not less than ² cm ² is preferably contained in the diluted paint at 40% by weight or more, particularly preferably at 50% by weight or more. When the content of the organic solvent (C) having a surface tension of 34 dyn / cm ² or more is less than 40% by weight, the efficiency with which the leafing type aluminum flake pigment (A) floats on the upper layer surface of the enamel coating film is low, and the luster is inferior. In addition, a portion where the glittering material is not oriented is likely to be present, and a coating film having a uniform metallic feeling cannot be stably formed. Specific examples of such an organic solvent (C) include dioxane, acetophenone, 2-pyrrolidone, N-methylpyrrolidone, cyclohexanone, anisole, tetrahydrothiophene, dimethylsulfoxide, sulfolane, 2-phenoxyethanol, furfuryl alcohol, and tetrahydrofuran. Furyl alcohol, diethylene glycol, diethylene glycol monomethyl ether, triethylene glycol,
2-chloroethanol, furfural, bis (2-chloroethyl) ether, morpholine, dichloroacetic acid, o-
Chloroaniline, DBE (trademark, manufactured by DuPont, dibasic acid ester) and the like.

The metallic coating composition of the present invention composed of these raw materials is an organic solvent having a high surface tension (C).
Is added in an appropriate amount to increase the efficiency with which the leafing type aluminum flake pigment (A) floats on the upper layer surface of the enamel coating film, and the leafing type aluminum flake pigment does not cause cohesive peeling of the enamel coating film in the adhesion test. Even when the blending ratio of (A) is low, the glitter is high,
This is to form a coating film having a uniform metallic appearance.

The metallic coating composition of the present invention comprises, in addition to the essential components, a leafing type aluminum flake pigment (A), a film-forming resin (B), and an organic solvent (C) having a surface tension of 34 dyn / cm ² or more, Other components can be added as needed. As such other components, pigments, additives, organic solvents and the like conventionally used in paints can be used.

As the pigment, those conventionally used for paints are conventionally used. For example, organic pigments such as azo lake pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, quinophthalone pigments, and dioxazine pigments are used. And quinacridone pigments and the like, and inorganic substances include graphite, yellow iron oxide, red iron oxide, carbon black, titanium dioxide and the like. As additives, thixotropic agents such as organic bentonite and synthetic silica, ultraviolet absorbers, hindered amine light stabilizers (HAL
S), a quencher, an antioxidant, a curing catalyst and the like. Further, as the organic solvent, an aromatic hydrocarbon solvent,
Ester solvents, ketone solvents, alcohol solvents, ether solvents and the like can be used.

The coating of the metallic coating composition of the present invention comprises:
The coating can be performed by a conventionally known coating method such as an air spray method and an electrostatic method using an atomizing type coating machine.

The metallic coating composition of the present invention is suitably applied so as to have a dry film thickness of 3 to 30 μm, preferably 5 to 15 μm, at a temperature of 60 to 200 ° C.
By heating for 0 to 60 minutes, a cured coating film can be obtained.

In the metallic coating composition of the present invention, a clear coat coating or a colored transparent coating can be applied on the cured coating film. As a coloring agent to be incorporated in the colored transparent coating, a pigment or a dye conventionally used for coatings can be used. Examples of the pigment include organic azo lake pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, quinacridone pigments, and the like. Examples include lead, yellow iron oxide, red iron oxide, carbon black, and titanium dioxide. Examples of the dye include anthraquinone type, perinone type, and azo type. The colored transparent paint may contain a coloring agent that allows the cured metallic paint film of the present invention to be seen through the cured paint film.

[0019]

The present invention will be more specifically described below with reference to examples and comparative examples. However, the present invention is not limited to these embodiments, but is based on the configuration described in the claims. In addition, in each of Examples and Comparative Examples, unless otherwise specified, parts represent parts by weight and% represents% by weight.

Examples 1 and 2 and Comparative Examples 1 to 5 Epoxy resin cationic electrodeposition paint, Aqua, NO. 4
200F (trademark, manufactured by NOF CORPORATION) with a dry film thickness of 25
It was electrodeposited to a thickness of μm and baked at 175 ° C. for 30 minutes to obtain an object to be coated. Next, the metallic coating compositions of Examples 1-2 and Comparative Examples 1-5 having the composition shown in Table 1 were spray-coated on the surface so as to have a dry film thickness of 10 μm.
After leaving at room temperature for 10 minutes, it was baked at 140 ° C. for 30 minutes to prepare a coated plate. An acrylic / melamine resin clear coat paint and Bellcoat HS-1 clearing aluminum for aluminum (manufactured by Nippon Oil & Fats Co., Ltd.) were used as the clear coat paint on this coated plate as Solvesso 100 (manufactured by Esso Co., Ltd., trademark, The viscosity was adjusted with an aromatic organic solvent) for 25 seconds (Food cup No. 4, 20 ° C.), and spray coating was performed so that the dry film thickness was 35 μm. 1 at room temperature
After leaving it for 0 minutes, it was baked at 140 ° C. for 30 minutes to prepare a test piece. Using these test pieces, the adhesion and appearance were evaluated by the following test methods. Table 1 shows the evaluation results.

(1) Adhesion The adhesion was measured by cutting a line with a cutter knife so as to reach the substrate and drawing 100 squares of 1 mm × 1 mm.
A cellophane tape was adhered to the surface, and the state of the coated surface after sharply peeling off was observed.は indicates no peeling of the paint film. × indicates that peeling of the painted film is 10
Indicates that more than one was found.

(2) Metallic appearance The metallic appearance was evaluated by visual evaluation. ○ is finished in a uniform plating tone. × indicates an inferior plating appearance or an uneven appearance in which a portion where the glittering material is not oriented exists.

(3) IV The IV was obtained by using a laser-type metallic feeling measuring device ALCOPE LMR-200 manufactured by Kansai Paint Co., Ltd.
This is a value given by the following equation from the signal output iv at 35 °. IV = K ₁ × iv (K ₁ is a coefficient) An IV of 300 or more was evaluated as good.

(4) FF FF is a value given by the following equation based on the signal output iv at the light receiving angle of −35 ° and the signal output sv at the light receiving angle of 0 ° measured in the above (3). FF = K ₃ × (iv−sv) / (iv + sv) (K ₃ is a coefficient) An FF of 1.70 or more was evaluated as good.

[0025]

[Table 1]

Examples 3-4, Comparative Examples 6-10 A 3 mm thick, 7 cm × 12 cm A manufactured by Sumitomo A & L Co., Ltd.
The BS substrate and the plastic MV were degreased using isopropyl alcohol to obtain an object to be coated. Next, the two-pack metallic coating compositions of Examples 3 to 4 and Comparative Examples 6 to 10 having the composition shown in Table 2 were spray-coated so as to have a dry film thickness of 10 μm, and left at room temperature for 10 minutes. At 75 ° C. for 30 minutes to prepare a coated plate. An acrylic / urethane resin-based two-pack clear coat paint, clear for high urethane LV8 leafing aluminum (manufactured by NOF Corporation), Solvesso 100 (manufactured by Esso Corporation), as a clear coat paint, was applied to this coated plate. , An aromatic organic solvent) for 20 seconds (Food Cup No. 4, 20 ° C.), and spray-coated to a dry film thickness of 35 μm. After leaving it at room temperature for 10 minutes, it was baked at 75 ° C. for 30 minutes to prepare a test piece. Using these test pieces,
Adhesion and appearance were evaluated by the methods described above. Table 2 shows the evaluation results.

[0027]

[Table 2]

As is clear from the results in Tables 1 and 2, it was confirmed that the metallic coating compositions of Examples 1 to 4 of the present invention formed coating films having excellent metallic appearance and good adhesion. Was done. It was confirmed that the metallic appearance was good both visually and as measured values. On the other hand, the weight ratio of the leafing type aluminum flake pigment (A) to the coating film forming resin (B) is within the range of the present invention (5:95 by weight ratio).
It can be seen that Comparative Examples 1, 2, 6, and 7 out of 30 to 70) were inferior in metal appearance or adhesion. That is, in Comparative Examples 1 and 6 in which the blending amount of the leafing type aluminum flake pigment (A) is too small, the glittering material floating on the upper layer surface of the enamel coating film is insufficient, so that the glittering feeling is poor and the glittering material is not oriented. Were easily present, and the metallic appearance was deteriorated. On the other hand, in Comparative Examples 2 and 7 in which the blending amount of the leafing type aluminum flake pigment (A) is too large, the enamel coating film was apt to undergo cohesive peeling, and the adhesion was poor. On the other hand, an organic solvent (C) having a surface tension of 34 dyn / cm ² or more
In Comparative Examples 3, 4, 8, and 9 in which the blending amount of (A) was out of the range (40% by weight or more) of the present invention, the leafing type aluminum flake pigment (A) was sufficiently applied to the upper layer surface of the enamel coating film. The metal appearance was poor because it did not float. In Comparative Examples 5 and 10 in which the non-leafing aluminum flake pigment was blended in place of the leafing aluminum flake pigment (A) of the present invention, no metallic appearance was obtained.

[0029]

In summary, according to the metallic coating composition of the present invention, not only the metallic feeling is high, the metallic feeling is high, the glittering property is strong, the flip-flop property is high, etc., but also the adhesiveness is excellent. A good coating film can be formed stably.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akiko Tanaka 1-4-1 Chuo, Wako-shi, Saitama Pref. In Honda R & D Co., Ltd. (72) Inventor Tsuyoshi Tsunoda 4-13-13 Nishioi, Shinagawa-ku, Tokyo ( 72) Inventor Shinji Komune 2-8-24-205 F-term (reference) 4J038 CD091 CD092 CG002 CG141 DB001 DB002 DD001 DD002 DG001 DG002 DL031 DL032 DL161 DL162 GA03 GA06 GA07 GA15 HA066 KA03 KA06 KA20 MA12 MA09 NA01 NA12 PA19 PC01 PC06 PC08 PC10

Claims (1)

[Claims] 1. A leafing type aluminum flake pigment (A), a film-forming resin (B), and a surface tension of 34 dyn / c.
containing m ² or more organic solvents (C), the weight ratio 5: 95 to 30 pairs 70 of leafing type aluminum flake pigment (A) Tainurimaku forming resin (B), the surface tension 34dyn
A metallic coating composition comprising an organic solvent (C) of at least 40% by weight / cm ² or more in a diluted coating material.