JP3249439B2 - How to paint on metal molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for coating metal products used for exterior parts such as vehicles.

[0002]

2. Description of the Related Art Conventionally, for example, of exterior parts of a vehicle or the like,
As a method of coating metal products that require appearance quality, after performing cationic electrodeposition coating that is effective for corrosion resistance and drying, undercoat coating from above, and then topcoat There is known a so-called three-coat two-bake coating method in which coating is performed and dried.
When it is desired to further improve the appearance quality, so-called 4-coat 3-bake coating in which intermediate coating and drying are added may be performed between the cationic electrodeposition coating and the undercoat coating.

On the other hand, in order to reduce the number of painting steps and to improve the work efficiency, for example, Japanese Patent Laid-Open Publication No. Hei 5-3 discloses a coating method in which the same effect as that of two-coating can be obtained by coating only one coat.
A coating method such as 17804 has been proposed.

In this coating method, as shown in FIG. 3, a color clear coat 52 is applied to the surface of a resin molded article 51 containing a metallic powder and a coloring material without applying a base coat, and the resin molded article 51 is coated. The color tone and the color tone of the color clear coat 52 interact to enhance the design.

[0005]

However, forming a plurality of coats by repeating the three-coat, two-bake or four-coat, three-bake coating, as in the former, requires labor and time and is not efficient. .

[0006] In the latter case of JP-A-5-317804, the effect of a plurality of coats can be obtained with only one coat, so that it is efficient. Even if it is attempted to apply, it is difficult to form a metal by coloring and it is difficult to apply.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a coating method which is not inferior to the coating quality of conventional high-grade coated products or the like while reducing the number of coating steps when coating a metal molded product.

[0008]

In order to achieve the above object, according to the present invention, a color resin paint is electrodeposited on the surface of a metal molded article to form a base coat, and then a color clear paint is applied thereon. To form a top coat, and by the interaction of the base coat color and the top coat color,
A color tone different from that of the base coat paint and the top coat paint was obtained.

Here, as the metal molded product, for example, an iron-based, aluminum-based, or other conductive molded product may be used. As the color resin paint to be electrodeposited, for example, an acrylic resin paint, an epoxy resin paint, and other general water-soluble baking paints that can be electrodeposited can be applied.

The color clear paint is prepared by dispersing a coloring material or the like in a film-forming resin having high transparency, and without completely hiding the hue of the base coat of the undercoat, the color clear paint of the base coat and the color clear paint are used. Colorants and the like interact with each other so that different tones are obtained. As the color clear paint, for example, any general overcoat paint such as an acrylic or polyester bake-curing type or a reaction-curing type can be used.

The colorant contained in the color resin paint and the color clear paint includes, for example, a colorant having a normal hue such as red, blue, and yellow, and a colorant having a pearl tone, a metallic tone, a fluorescent tone, and the like. Is also included. In addition, as a method of applying the color clear paint, for example, spray painting or the like can be applied.

[0012]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a sectional view of a painted surface painted by the painting method according to the present invention, and FIG. 2 is a process chart for explaining the painted method.

The coating method according to the present invention is constructed as an improved technique for coating iron-based metal products among exterior parts such as vehicles, for example. Even for parts requiring appearance quality, painting is performed so that appearance quality is not deteriorated, and man-hours are reduced.

That is, as shown in FIG. 2, a pretreatment for painting is performed on a metal-made product such as an iron-based product. This pre-treatment is the same as the conventional general pre-treatment, such as degreasing to remove oil or the like adhering to the surface of the molded article, surface adjustment to promote the formation of a chemical conversion coating, increasing the adhesion of the coating, etc. And the like, and if necessary, may be performed by omitting some of the steps in accordance with the molding state of the metal molded article.

After the pre-coating treatment, an electrodeposition coating is performed with, for example, a color acrylic resin paint. That is, a metal molded product is immersed in a batch tank containing a color acrylic resin paint, a DC voltage is applied between the metal molded product and the tank, and the resin, pigment, etc. in the paint are electrophoretically removed from the metal molded product. To form a coating film.

As shown in FIG. 1, a base coat 2 is formed on the surface of a metal molded product 1 by this color acrylic electrodeposition coating. At this time, the base coat 2 mainly has a weather resistance function, an appearance function and the like. To have the function of overcoating. In addition, such electrodeposition coating is automatically performed only by immersing it in a batch tank, and thus does not require any human labor. In addition, weather resistance can be improved by electrodepositing a color acrylic resin paint.

For such color acrylic resin electrodeposition, for example, by preparing a batch tank of 3 to 4 colors and acting in combination with the color of a color clear paint described later, a variety of colors can be obtained. Can be done.

When the color acrylic resin electrodeposition is completed, it is dried. This drying usually requires about 30 minutes to completely dry the base coat 2. However, when a baking type paint is applied to the color clear coating in the subsequent step,
The process is finished in a dry state at a temperature of 140 to 150 ° C. for about 5 minutes, and the time can be reduced.

A color clear paint is applied to the upper surface of the base coat 2 by spray coating or the like. Then, Figure 1
As shown in FIG. 5, a top coat 3 made of a color clear paint is formed on the base coat 2. And the color clear paint used for this color clear coating is a material in which a coloring material or the like is dispersed in a highly transparent film-forming resin, and the hue of the base coat of the base is not completely hidden,
The colorant of the base coat and the colorant of the color clear paint interact to provide different shades.

The colorant contained in the color resin paint and the color clear paint may be, for example, a colorant having a normal hue such as red, blue, or yellow, or a colorant having a pearl tone, a metallic tone, a fluorescent tone, or the like. Is also included.

When the color clear coating is completed, the color clear coating is dried and finished. Thus 2 coats 2
The product finished by the baking method has a hue of the top coat 3 and a hue of the base coat 2 acting on each other to produce different tones, and various colors can be expressed by a combination of colors.

Further, the above-mentioned coating method using two coats and two bake is a conventional three coat two bake or four coat three bake.
Compared with the coating quality of baking and the like, the cost can be reduced because the conventional man-hour can be greatly reduced.

The present invention is not limited to the above embodiment. Those having substantially the same configuration as those described in the claims of the present invention and exhibiting the same operation and effect belong to the technical scope of the present invention. For example, the material of the metal molded product is not limited to the iron type, and the color resin electrodeposition paint may be a resin paint other than the acrylic resin.

[0024]

As described above, according to the coating method of the present invention, a color resin paint is electrodeposited on the surface of a metal molded product to form a base coat, and then a color clear paint is applied from above to form a top coat. Is formed so that a color tone different from the color tone of the base coat paint and the color of the top coat paint is obtained by the interaction between the color tone of the base coat and the color tone of the top coat, so that the conventional three-coat two-bake or four-coat three-bake, etc. Coating process can be greatly reduced. Moreover, since the colors of the base coat and top coat interact to express a variety of colors,
The appearance quality can be easily improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a painted surface painted by a painting method according to the present invention.

FIG. 2 is a process chart for explaining the present coating method.

FIG. 3 is an explanatory view of a method for coating a conventional resin molded product.

[Explanation of symbols]

1. Molded metal products, 2. Base coat, 3. Top coat.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B05D 1 / 36,5 / 06 B05D 7 / 14,7 / 24

Claims (2)

(57) [Claims] [Claim 1] After the formation of the base coat the color resin coating electrodeposition coating to the surface of the metal molded article, before over this
Face with a different color tone from the pigment contained in the color resin paint
A topcoat formed by applying a color clear paint containing a base material, so that a color tone different from that of the basecoat paint and the topcoat paint can be obtained by the interaction between the color tone of the basecoat and the color tone of the topcoat. A method for coating a metal molded article characterized by the following. 2. A coating on the metal molded product according to claim 1.
In the method, after forming the base coat, the base coat is formed.
Heat the scotch to a dry state, then
Apply a color clear paint from above, and then
The special feature is that the paint and color clear paint are baked simultaneously.
This is a method of coating metal molded products.