JPH0256152B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of painting an automobile body, etc., and more specifically, to a method of painting an automobile body, etc., in which parts that do not need to be painted are masked and painted.

Conventionally, when painting the body of a car, the parts that do not need to be painted are masked and painted. Masking involves pasting paper or synthetic resin film to the parts that do not need to be painted, or applying a synthetic resin solution that eliminates the need for painting. Methods such as applying it to the area and drying it to form a peelable film have been adopted. However, although these masking methods can reliably protect areas that do not require painting and prevent the formation of a coating film on areas that do not require painting, they have the trouble of having to peel off the masking film after painting. In particular, most of the painting process for automobile bodies is automated, and there is very little human intervention in the painting process, but peeling and removal of the masking film is difficult to automate and requires manual labor. The masking film is peeled off one by one, which is very troublesome and also poses problems in terms of workability. For this reason, there has been a desire to simplify the peeling and removal of the masking film, to reduce the need for human hands, and to automate it.

The present invention was made in response to the above-mentioned needs, and it is possible to peel off and remove the masking film on parts that do not need to be painted after painting an automobile body, etc., with almost no human intervention. The purpose of the present invention is to provide a method for painting automobile bodies, etc., which can also automate peeling and removal.

That is, in order to achieve the above object, the present invention applies a synthetic resin film that shrinks at the baking or drying temperature of the paint film to the parts of the object to be painted, such as automobile bodies, that do not need to be painted, using an adhesive with weak adhesive strength. Then, after painting with an appropriate paint, this coating film is baked or dried, and the synthetic resin film is shrunk during or immediately after this baking or drying process, thereby eliminating the need for painting. The adhesive is shrunk following this contraction, and the shrunken synthetic resin film is peeled off from the object to be coated together with the adhesive.

The present invention will be explained in more detail below.

The painting method according to the present invention is effectively employed for painting automobile bodies, etc., and is applied when painting is performed by masking unnecessary parts of the object to be painted.

In the present invention, as such a masking method, a synthetic resin film that shrinks at the temperature employed in the baking or drying process after painting is attached to the parts of the object to be painted that do not need to be painted via an adhesive with weak adhesive strength. It is something.

In this case, the synthetic resin film that shrinks at the baking or drying temperature of the coating film, such as biaxially stretched polypropylene film, polyethylene film, polyvinyl chloride, etc., is suitably used. In addition, as an adhesive for adhering this shrinkable synthetic resin film to the object to be painted, the shrinkable synthetic resin film is applied to the object to be painted during painting, and the film is applied when baking or drying the coating film. An adhesive is used that has such a weak adhesive force that when it shrinks, the adhesion of the object to be coated is released following this shrinkage, and it is peeled off from the object. A width of about 25mm is used. In this case, when adhering the shrinkable synthetic resin film to the object to be painted, one side of the film may be coated with the adhesive with weak adhesive strength, and the film may be applied to the object to be painted. The shrinkable synthetic resin film may be adhered to the film surface of a so-called slightly adhesive film, on which a layer of the adhesive with weak adhesive strength has been formed in advance, and this may be applied to the object to be coated. In addition, as such a slightly adhesive film,
Specifically, Nitto Denko's slightly adhesive film SPV
etc. may be used.

In the present invention, the parts of the object to be painted that do not need to be painted are masked by the method described above, and then the parts are painted. In this case, the coating method and type of paint are not necessarily limited; for example, spray coating, electrodeposition coating, electrostatic coating, etc. may be employed, and modified alkyd resins such as alkyd resins and amino-alkyd resins, Paints such as amino-acrylic resin, amino-epoxy resin, amino-polyester resin, and polyurethane resin are used, and in any case, appropriate coating methods and paints are used depending on the type of object to be painted, such as an automobile body, and the purpose of painting. is selected. Although the method of the present invention can be applied to any of the undercoating, intermediate coating, and finishing coating, it is particularly suitable for finishing coating.

After painting, the paint film is baked or dried, and in this case, the baking or drying temperature and time are set to normal conditions depending on the type of paint.
In the present invention, in this baking or drying process, the shrinkable synthetic resin film that shrinks at the baking or drying temperature starts to shrink, and at the same time, the adhesive layer that adheres the shrinkable synthetic resin film starts shrinking. The shrinkable synthetic resin film is stretched by the film, contracts by the shrinkage force following the film, and is peeled off from the object to be coated, so that the shrinkable synthetic resin film peels off from the object to be coated together with the adhesive. be. In this case, peeling of the film may occur during the baking or drying process, or it may occur near the end of the baking or drying process or after the completion of the baking or drying process. In any case, the type and thickness of the shrinkable synthetic resin film or adhesive to be used depends on the material, surface condition, surface shape, etc. of the parts of the object to be painted that do not need to be painted, so that shrinkage will occur during this baking or drying stage. It is preferable to select

As described above, the present invention eliminates the need for painting by attaching a synthetic resin film that shrinks at the baking or drying temperature of the paint film via a weak adhesive to parts of objects to be painted such as automobile bodies that do not require painting. After masking the area and then painting with appropriate paint,
By baking or drying this coating film and shrinking the synthetic resin film during or immediately after this baking or drying process, the adhesive is caused to follow this shrinkage and shrink, and the adhesive is removed from the object to be coated. And since the shrunken synthetic resin film is peeled off at the same time, the masking film (synthetic resin film and adhesive layer) will naturally peel off from the object to be coated, and even if it does not completely peel off, Since most of the paint has peeled off from the object to be coated, it can be easily removed. Therefore, according to the present invention, peeling and removal of the masking film hardly requires human intervention, and the masking film can be naturally peeled off during or immediately after the baking or drying process of the coating film. Therefore, along with the automation of the baking or drying process, the removal of the masking film can also be automated.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to examples, but the present invention is not limited to the following examples.

Example 1 Nitto Denko's slightly adhesive vinyl chloride film SPV-201 (peel adhesion 150 g/25
mm) and then painted with alkyd resin paint. This was baked and dried at 140°C for 1 hour, but the polypropylene film shrunk during the drying process.
Following this, the slightly adhesive film shrank, and the polypropylene and the slightly adhesive film peeled off together.

In the obtained coated plate, no coating film was formed on the adhesive portion of the film, and it was recognized that masking was good.

Example 2 Nitto Denko's slightly adhesive polyethylene film SPV-3261 (peel adhesion strength 50 g/25 mm) with biaxially oriented polypropylene film adhered to the designated area of a steel plate whose entire surface had been previously coated with epoxy resin paint was attached. After that, the coating was painted, baked and dried in the same manner as in Example 1, and the same results as in Example 1 were obtained.

Claims (1)

[Claims] 1. Apply a synthetic resin film that shrinks at the baking or drying temperature of the paint film via a weak adhesive to the parts of the object to be painted, such as an automobile body, that do not need to be painted, to mask the parts that do not need to be painted, and then mask the parts that do not need to be painted. After painting with a paint, this paint film is baked or dried, and the synthetic resin film is shrunk during or immediately after this baking or drying process, so that the adhesive follows this shrinkage and shrinks. . A method for painting automobile bodies, etc., characterized in that the adhesive and the shrunken synthetic resin film are peeled off from the object to be painted.