JPS63302979A - Painting method for automobile - Google Patents

Abstract

PURPOSE:To elevate the workability for painting by introducing unibase coat painting stage clear-coat painting stage and baking/drying stage, etc. CONSTITUTION:A body 1 and a bumper 2 are painted with the same paint (unibase coat) to obtain a metallic base coat. Then, the surface of the body 1 is coated with acryl melamine resin and baked in a drying furnace 7. On the other hand, clear coat is applied to a metallic base coated bumper 2, too, and amine curing is performed by an amine curing device 8. In this manner, acryl reaction is promoted, the coated film is cured and the bumper 2 completes painting. According, color matching property can be improved between the body and the parts.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method of painting an automobile body, bumper, etc.

(Prior Art) In automobiles, a body made of a steel plate is combined with a bumper made of urethane having the same color as the body.

Conventionally, in such automatic 1m painting, the steel plate body and the resin bumper have been painted in completely separate processes. Specifically, in the case of metallic painting, as shown in Figure 2, a one-component acrylic melamine resin is applied to the surface of the body a, and then an acrylic melamine resin is applied and a clear coat is applied. This coating is baked and dried using drying oven C (20 minutes at 140°C).

In addition, for bumper d, as shown in Fig. 3, a two-component urethane resin base coat e is applied to the surface of the bumper d, and then a two-component urethane resin clear coat f is applied to give a clear coat. was similarly baked and dried using drying oven C (20 minutes at 120°C).

(Problems to be Solved by the Invention) However, this method of painting completely separately has a drawback in terms of color matching between the two. Moreover, since they were all separate, it was said that the workability was not very good.

This invention was made in view of these problems, and its purpose is to improve color matching between a body made of steel plate and parts made of resin, and to improve workability. Our goal is to provide a method for painting cars that is possible.

[Structure of the Invention] (Means and effects for solving the problem) That is, a process of coating a body made of a steel plate and parts made of resin attached to the body with Unibase Coat, and a process of coating the body with the Unibase Coat. The process of applying a clear coat on the base coat that has been applied to the parts, the process of baking and drying this paint, the process of applying a clear coat on the base coat that has been applied to the above-mentioned parts, and the process of subjecting this paint to an amine hardening process. By painting the parts, using the same paint as the base coat allows the body and parts to match in the same color and improves workability.

(Example) Hereinafter, the method of this invention will be explained based on an example shown in FIG.

For example, a body made of steel plate 1. To explain this using an example of applying metallic paint of the same color to rim urethane (or PP; polypropylene) bumper 2, first apply metallic base coat to body 1 and bumper 2 using the same paint (unibase coat). Paint (unibase coat process). This base coat is a metallic base coat made of acrylic resin with a common two-component base coat, in which base coat 3 is common and curing agent 4.5 is used separately for body 1 and bumper 2. Specifically, acrypolyol is used as the main agent 3, and blocked isocyanate or inthyanate is used as the curing agent 4. For example, a gun 6 is used to coat the surface of the body 1 with two liquids of acrypolyol and blocked isocyanate. This is done by coating the surface of the bumper 2 with a two-part paint consisting of acrypolyol and isocyanate. Note that the body 1 and the bumper 2 may be coated using a one-component supply system instead of a two-component supply system, for example, using polynistate melamine as a unibase coat.

After completing this Unibase Coat process,
Next we move on to the clear coat process.

Specifically, the surface of the body 1 is coated with acrylic melamine resin. And, as before,
When this coating is baked and dried in the drying oven 7 (baking drying process), the coating film is hardened and the VLJ installation process of the body 1 is completed.

-2 is also given one clear coat. For example, aqua polyol is used as the main agent 3, and isocyanate is used as the hardening agent 4.
This is done by applying the same two-component urethane paint to the surface of the bumper 2 (clear coating process). Then, such coating is subjected to amine curing (curing using vaporized amine liquid) using amine curing treatment 818. As a result, the acrylic reaction is accelerated, the coating film is cured (amine curing process), and the coating of the bumper 2 is completed.

The painting method for such automobiles is based on the body 1. Since a common base coat is used for the bumper 2, it is possible to significantly improve the color matching properties of the bumper 2 and the bumper 2 compared to conventional painting methods. Moreover, since the same paint is used, workability is also improved.

Furthermore, the method of curing the paint film by accelerating the acrylic reaction using amine treatment can cure the paint film at a lower temperature and in a shorter time than conventional baking drying, which reduces costs by saving energy. be able to. Moreover,
Amine curing seals pinholes and improves appearance.

In one embodiment, the present invention is applied to a rim acrylic bumper, but the present invention is not limited thereto, and can also be applied to SMC, etc., and furthermore, to exterior parts such as grills, interior parts, etc. Further Effects of the Invention As described above, according to the present invention, it is possible to improve color matching between a body made of a steel plate and parts made of resin, which are painted in the same color, and to improve designability. can.

Moreover, the amine treatment allows parts made of resin to be cured at lower temperatures and in a shorter time than conventional baking drying, and costs can be reduced by saving energy. Moreover, it has the advantage of improving appearance.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a preferred embodiment of the present invention method along with the progress of the painting process, Fig. 2 is a block diagram showing the progress of the body painting process in a conventional automobile painting method, and Fig. FIG. 3 is a configuration diagram showing the progress of the painting process for a bumper that is the same color as the body. 1...Body, 2...Bumper, 3...Main agent, 4
... Curing agent, 7... Drying oven, 8... Amine treatment I
II.

Claims (1)

[Claims] a step of applying Unibase Coat to a body made of a steel plate and parts made of resin attached to the body;
A process of applying a clear coat onto the base coat applied to the body, a process of baking and drying this paint, a process of applying a clear coat onto the base coat applied to the parts, and a process of subjecting this paint to amine curing treatment. A method for painting an automobile, comprising: