JPH0570719A - Metallic paint and method of application thereof - Google Patents

Abstract

PURPOSE:To provide a bright metallic coating film excellent in flip flop properties and brilliancy in a medium- to high-lightness range by applying a metallic paint containing a colored scaly aluminum pigment and mica powder and then a clear paint. CONSTITUTION:The lightness of a coating film is adjusted to a Munsell value of 3 or more by mixing 100 pts.wt. solid resin component of a vehicle constituent (e.g. an ordinary thermosetting coating resin composition) with 5-30 pts.wt. colored scaly aluminum pigment prepared by the chemisorption of a colored pigment on the surface of an aluminum pigment via a thermally polymerizable carboxylic acid having one or more double bonds and two or more carboxyl groups in the molecule and subsequent coating with a polymer prepared from a radical-polymerizable unsaturated carboxylic acid and a monomer having three or more radical-polymerizable double bonds and 0.1-30 pts.wt. mica powder (e.g. white mica) to form dispersion, and adding thereto, if necessary, other colored pigment, metallic pigment, extender and various additives.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel metallic paint having excellent flip-flop properties, and a bright metallic paint film having excellent luster even in the range of medium to high brightness and high saturation, and its coating method. Regarding

[0002]

2. Description of the Related Art Metallic paints using aluminum pigments are known and have a flip-flop property (flip-flop property).
/ Frop) and is often used as a paint for automobiles. However, in recent years, the demand for cosmetics (finished appearance) has become high, and it is strongly desired to develop a metallic paint that forms a coating film having an excellent metallic feeling and flip-flop property even in a color region having high lightness and saturation. However, the metallic paint using the above-mentioned aluminum pigment is insufficient to meet such demand. Further, it has been attempted to use mica, a coloring pigment, or the like instead of or at the same time as the aluminum pigment, but it has not been possible to meet the above demand.

[0003]

Therefore, as a result of intensive research to develop a metallic coating material satisfying the above-mentioned needs, the present inventor achieved the object by using a colored aluminum pigment and mica powder in combination. The present invention has been completed.

That is, the present invention provides a metallic coating material containing a flaky colored aluminum pigment and a mica powder, and coating the metallic coating material,
Next, the present invention relates to a coating method characterized by applying a clear paint.

In the present invention, the flip-flop property means that when the metallic coating surface is viewed at a specular reflection angle with respect to the incident angle of light (highlight color) and when viewed at other angles (shade color). It is said that each has a metallic feeling, and if the metallic feeling is different between the two, it is said to have "flip-flop characteristics". Therefore, a metallic coating film having a flip-flop property can be said to be a coating film having a high degree of beauty, since the metallic feeling changes every moment depending on the viewing angle.

First, the colored aluminum pigment itself used in the present invention is known, for example, JP-A-1-315470.
The colored metallic pigments described in the publication can be preferably used. That is, the colored aluminum pigment is obtained by chemically adsorbing the colored pigment through a thermally polymerized carboxylic acid having one or more double bonds and two or more carboxyl groups in the same molecule on the surface of the aluminum pigment. Some (primary color pigment), or one that is further chemically adsorbed with it is coated with a polymer composed of a radically polymerizable unsaturated carboxylic acid and a monomer having three or more radically polymerizable double bonds (secondary coloring). Pigment). Details of these are omitted because they are described in the above publication, but the outline thereof is as follows.

The shape of the aluminum pigment to be colored is preferably a scaly shape, and its average particle size is 1 to 100 μm.
Especially 2 to 50μ, average thickness 0.1 to 5μ, especially 0.3
~ 3μ is preferred. The aluminum pigment is preferably coated with a fatty acid such as oleic acid and stearic acid before the above treatment.

The coloring pigment for coloring the aluminum pigment may be either an organic pigment or an inorganic pigment as long as it does not dissolve in the organic solvent used during its production, and is not particularly limited. The organic solvent used in the production of the colored aluminum pigment is preferably one or more selected from aliphatic hydrocarbons, aromatic hydrocarbons, esters and ethers.

The heat-polymerized carboxylic acid is one in one molecule obtained by heat-polymerizing, for example, linseed oil fatty acid, soybean oil fatty acid or acrylic acid having a double bond and a carboxyl group.
Those having one or more double bonds and two or more carboxyl groups are used. Those that do not undergo thermal polymerization may have insufficient adsorption on the surface of the aluminum pigment. The amount of the heat-polymerized carboxylic acid used varies depending on the specific surface area of the aluminum pigment and the amount of the color pigment, but is 0.2 to 15 parts by weight, particularly 1 to 100 parts by weight of the aluminum pigment having a specific surface area of 1 m ² / g. 7 parts by weight is preferred.

First, an outline of a method for producing a primary color pigment will be described. An aluminum pigment and a heat-polymerized carboxylic acid are added to an organic solvent, and the temperature is raised and the mixture is stirred. The amount of the organic solvent is preferably 10 to 70 parts by weight of the aluminum pigment per 100 parts by weight of the organic solvent, and the stirring temperature is suitably 50 to 150 ° C. After stirring, the mixture is filtered, and the aluminum pigment having the layer of the thermally polymerized carboxylic acid formed on the surface is collected as a filter cake. Next, a color pigment dispersed and stirred together with an organic solvent is added to this, and the mixture is kneaded, stirred or mixed with stirring. The amount of the coloring pigment varies depending on the specific surface area of the aluminum pigment, but in the case of the aluminum pigment having an average particle size of 22μ and WCA (water coating surface area of aluminum pigment) 7400 cm ² / g, 1 to 50 parts by weight relative to 100 parts by weight of the aluminum pigment. Parts, especially 5 to 20 parts by weight are preferred. This operation is 60
It is preferably carried out at a temperature of not higher than ° C. A primary coloring pigment is obtained here, but it is preferable to separate the organic solvent in order to use it as the metallic pigment in the present invention as it is.

Next, a method for producing the secondary color pigment will be described. Examples of the radical polymerizable unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid and fumaric acid, and examples of the monomer having three or more radical polymerizable double bonds include trimethylolpropane triacrylate and tricarboxylic acid. Methylolpropane trimethacrylate, tetramethylolethane triacrylate, tetramethylolethane tetraacrylate and the like are suitable.

In order to produce a secondary color pigment using these, a radical-polymerizable unsaturated bond is added by adding 400 to 2000 parts by weight of an organic solvent to 100 parts by weight of the aluminum content of the primary color pigment and stirring vigorously. After the addition of the carboxylic acid and the addition of 5 to 20% by weight of a monomer having three or more radically polymerizable double bonds and a polymerization initiator, the surface of the primary color pigment is formed by a highly crosslinked resin film. To be covered. The secondary color pigment thus obtained is separated from the organic solvent and appropriately dried to obtain a colored metallic pigment excellent in water resistance and chemical resistance.

The scaly colored aluminum pigment used in the present invention has an excellent metallic luster and can be colored in any color. In the present invention, it is preferable to use a secondary color pigment among the above colored aluminum pigments.

The mica powder used in the present invention includes mica whose surface is coated with titanium oxide (so-called white mica, interference mica, etc.), colored mica coated with iron oxide and organic pigments, all of which are known. Can be used. The shape of the mica powder is preferably scaly pieces, and its size (particle size, thickness, etc.) is preferably in the same range as that of the aluminum pigment to be colored.

The metallic coating material of the present invention contains the above-mentioned scaly colored aluminum pigment and mica powder,
Specifically, it is obtained by mixing and dispersing these in a vehicle component.

As the vehicle component, an ordinary resin composition for thermosetting paints is preferable, and for example, one or more base resins selected from acrylic resins, alkyd resins, polyester resins and modified resins thereof, amino resins and poly resins. Examples thereof include a composition comprising a crosslinking agent selected from isocyanate compounds (including blocked compounds).

In the present invention, the amount of the scaly colored aluminum pigment is 10% by weight of the resin solid content of the vehicle component.
5 to 30 parts by weight, particularly 10 to 20 parts by weight, are preferred per 0 part by weight. The amount of the mica powder blended was similarly 0.
A range of 1 to 30 parts by weight, particularly 1 to 15 parts by weight is preferable.

The metallic coating material of the present invention can be obtained by mixing and dispersing the above-mentioned scaly colored aluminum pigment and mica powder in a vehicle component. If necessary, other coloring pigments, metallic pigments, extender pigments and It is possible to mix various additives. In particular, the brightness of the metallic coating is determined by the Munsell value (V).
On the other hand, it is desirable to adjust it to 3 or more, preferably 5 or more, because the technical effect of the present invention can be sufficiently exhibited. Further, the metallic paint is most preferably an organic solvent type using an organic solvent as a solvent or a dispersion medium, but may be an aqueous type having water as a main solvent or a dispersion medium.

The feature of the coating method of the present invention resides in that the above metallic paint is applied, and then the clear paint is applied to the coated surface.

The clear coating is for coating on the coating surface of the metallic coating and contains a thermosetting resin as a vehicle component. As these vehicle components, it is preferable to use one or more selected from those exemplified as the vehicle components of the metallic paint. Further, a color pigment or a metallic pigment may be added to the clear coating material to such an extent that the original transparency is not impaired. Further, an ultraviolet absorber, a flow regulator and other additives for paints can be blended as required.

In the coating method of the present invention, the object to be coated is not particularly limited, and for example, metal or plastic is suitable.
Then, prior to the coating of the metallic paint, an undercoat paint (for example, a cationic electrodeposition paint) or an intermediate paint is preferably applied to these objects to be coated in advance as needed. Known paints can be applied to any of these.

The metallic coating is preferably applied by, for example, electrostatic coating, spray coating or dip coating. The coating film thickness is preferably in the range of 10 to 70 .mu. Can be arbitrarily selected depending on the crosslinking agent, but is preferably in the range of, for example, room temperature to 200 ° C. Then, the clear paint is applied to the hardened or uncured metallic coating surface. The coating method can be performed in the same manner as the above metallic paint, and the film thickness is 20% based on the cured coating film.
The range of .about.100 .mu. Is preferable, and the curing temperature may be in the same range as that of the metallic coating film. That is, the coating method of the present invention can be performed by either the 2-coat 1-bake method or the 2-coat 2-bake method.

The metallic paint of the present invention contains both the scaly colored aluminum pigment and the mica powder as essential components. Therefore, the formed metallic coating film has a high metallic brightness with high brightness even if it has high brightness and high saturation, and also has excellent flip-flop property, so that it has excellent cosmetic properties (finished appearance), and It is possible to finish a coating film that is rich in variety.

Examples and comparative examples relating to the present invention will be described below. Examples 1 and 2 and Comparative Examples 1 to 6 Metallic paints were manufactured by mixing and dispersing according to the composition and the blending amount shown in Table 1.

[0025]

[Table 1]

Colored aluminum red: "Friend Color F5"
00RE "trade name, Showa Aluminum Powder Co., Ltd., a flaky colored aluminum pigment, which corresponds to the secondary color pigment. Colored aluminum blue:" Friend Color F500BL "trade name, Showa Aluminum Powder Co., Ltd. Aluminum powder a: "Aluminum paste 55-516"
Product name, Toyo Aluminum Co., Ltd., aluminum powder paste Aluminum powder b: "Aluminum paste 55-519"
Product name, Toyo Aluminum Co., Ltd., same as above Interference Mica Blue: "EXTERIOR MEALIN HILITE BLUE"
Product name, Marl

Performance Test Results The metallic paints obtained in the above Examples and Comparative Examples were applied to a coated plate which had been coated with a cationic electrodeposition paint and an intermediate coating paint and cured so that the thickness would be 20μ based on the cured coating film. Then, after leaving at room temperature for 5 minutes, "Magiclon TC71 clear" (Kansai Paint Co., Ltd., trade name, organic solvent type amino resin / acrylic resin type 2 coat 1 bake clear paint) is also applied to the cured coating film. After being coated so as to have a thickness of 50 μ, both coating films were cured by heating at 160 ° C. for 30 minutes.

About the obtained coating film, a highlight portion (CR200, manufactured by Minolta Co., Ltd.) and a shade portion (manufactured by Suga Test Instruments Co., Ltd., SM color color computer MODEL)
The hue (H), lightness (V) and saturation (C) in SM-5) were measured. The results are shown in Table 2.

[0029]

[Table 2]

From the results shown in Table 2, in all the coating films obtained in the examples, the highlights and the shades both show a remarkable increase in saturation in colorimetry and visual evaluation, and the metallic appearance is pearly. And the brightness of aluminum tone are harmonized, and a coating film having an excellent finished appearance having excellent flip-flop properties can be obtained. On the other hand, in Comparative Examples 1 and 5 using only colored aluminum, the chroma was slightly increased as compared with Comparative Examples 2 and 6 in which an aluminum pigment and a coloring pigment were used in combination, but the color saturation was not sufficient, and the metallic composition had a flip-flop property. Is inferior. Further, Comparative Examples 3 and 4 in which an aluminum pigment, a coloring pigment and mica are used in combination have a flip-flop property but are inferior in saturation.

Claims (2)

[Claims] 1. A metallic paint comprising a flaky colored aluminum pigment and mica powder. 2. A coating method comprising applying the metallic paint according to claim 1 and then applying a clear paint.