JPH05222225A - Formed articles having coated layers - Google Patents

Abstract

PURPOSE:To provide formed articles with no fluctuation in the coated layers each article by forming the coated layer on the resin base material and forming the exposed part whose exposure is gradually changed by removing a part of the coated layer with laser beams or the like. CONSTITUTION:The base material 1 (for example, the back panel of a car) formed from a synthetic resin such as poly(methyl methacrylate) or polycarbonate is applied and baked with an acrylic lacquer on its inside surface to form a coated layer 2 of 10 to 30mum thickness. Then, the layer beam L is focused on the part from which the coated layer should be removed and allowed to irradiate the part with the output of 1 to 30W/m<2>. Only the coated layer irradiated is vaporized off. At this time, as the laser goes near the edge part, the interval I between the slit 3 of the removed coat layer and the slit 3 are made narrower (I1<I2<I3...) to form the exposed part in which the exposure density gradually changes. Thus, the formed articles having uniform color tone to the gradual change in the coated layer are produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article having a coating layer on the surface of automobile back panels, radiator grills, various display panels and the like.

[0002]

2. Description of the Related Art Conventionally, for example, in a back panel mounted between rear combination lamps of an automobile, a coating film is formed on the back surface of the back panel so that the film thickness of the end portion is gradually reduced to improve the design. Some are formed so that you can see the gradation of colors. To form such a color, a coating mask is arranged apart from the back surface of the substrate and spray coating is performed.

[0003]

However, since the molded products in the conventional color forming method are painted by hand, it is easy for the molded products to vary in the gradual change of the film thickness, and the mechanical coating However, it was not possible to obtain a satisfactory and uniform product as an automobile part. Further, there is a problem that it is difficult to follow a sudden change in shape in the case of a molded product having an uneven surface.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a molded product having a uniform color with respect to gradual change of a coating film, and for a molded product having a complicated shape. Another object of the present invention is to provide a molded article having a coating layer capable of obtaining a sufficient gradation color.

[0005]

In order to achieve the above object, therefore, in the molded article of the present invention, a coating layer is formed on the surface of the resin base material, and the coating layer exposes the base material. It is characterized in that it has an exposed portion to be exposed and the exposure density of this exposed portion is changed.

[0006]

[Function] When forming a gradually changing color, an exposed portion is formed in the coating film layer. By changing the exposure density of the exposed portion, gradually changing colors can be seen.

[0007]

Embodiment 1 An embodiment in which the present invention is embodied in a back panel of an automobile will be described below with reference to FIGS. As shown in FIG. 1, the back panel 5 of this embodiment comprises a base material 1 formed of a synthetic resin material and a coating layer 2 formed on the inner surface of the base material 1 and having a thickness of about 15 micrometers. It is configured. Here, since the coating layer 2 is partially removed by irradiation with the laser beam L described later, it is preferable to set the film thickness to 10 to 30 micrometers.

The synthetic resin material is a transparent synthetic resin such as PMMA (polymethylmethacrylate) or PC (polycarbonate). Here, the term "transparent" includes colorless and transparent, colored and transparent, and translucent. The coating layer 2 is formed of a paint having good adhesion to the inner surface of the base material 1, such as acrylic lacquer or urethane paint.

Next, a method of gradually changing the exposed portion of the coating film layer in the back panel 5 constructed as described above will be described. In this embodiment, a method of removing the coating film with a laser beam is used to form a gradually changing color. As the laser, a laser beam processing method that takes advantage of the characteristics of laser light was used. In this method, high-power laser light with good parallelism is applied to the surface of the workpiece in a converged state by utilizing an optical system means such as a lens, and is suitable for material removal. In addition, since this laser beam processing method can focus on a minute spot, it can sufficiently follow a complicatedly shaped substrate and can perform processing in a non-contact state. Since it can be processed at difficult angles, it is easy to automate, and since the force applied to the workpiece during processing is small, it is possible to process thin films. There are three types of lasers, a gas laser, a liquid laser, and a solid-state laser. In this embodiment, a solid-state laser (Nd-YAG laser) that can obtain a high output and has a small device was used.

Next, a method of forming an exposed portion whose exposure density is gradually changed by using the above-described laser light will be described with reference to FIGS.
It will be described with reference to FIG. First, prior to this irradiation with laser light, an acrylic lacquer is baked on the entire inner surface of the base material 1 at a low temperature to form a coating layer 2. And
As shown in FIG. 3, on the substrate 1 on which the coating layer 2 is formed as described above, the laser beam L is focused on the portion where the coating is to be removed by using an Nd-YAG laser beam machine, and 1 to 30 W /
The laser beam L is emitted from the irradiation unit 4 with an output of m ² .

When the coating film layer 2 is irradiated with the laser beam L, the temperature of the coating film at the irradiated portion reaches the evaporation temperature of itself in a very short time. As a result, only the portion irradiated with the laser light L is vaporized and removed. At this time, as shown in FIG. 2, as the portion to be removed is moved toward the end, the slit 3 of the removed coating film 3 is removed.
And the gap 3 between the slits 3 is narrowed (l ₁ <l ₂ <l
₃ )) to form an exposed portion in which the desired exposure density is gradually changed.

When the base material has irregularities, the height difference is about 3
The same output can be set up to about 0 mm, and if it is more than 0 mm, it can be handled by changing the output program when tracing the shape of the substrate.

[0013]

Example 2 A part of the coating layer was removed in the same manner as in Example 1. At this time, as shown in FIG. 4, by increasing the area S of the removed slit 3 toward the end (S
_{1> S 2> S 3 ...} ), it was varied the exposure density.

As described above, according to the molded article of this embodiment,
The work of arranging the masking material used in the prior art is unnecessary, and the predetermined color can be accurately formed by a simple process of irradiating the laser light L. In addition, it can easily follow complicated shapes and can be visually recognized as a beautiful appearance.

The present invention is not limited to the construction of the above-mentioned embodiment, and the present invention may be embodied in, for example, exterior parts for automobiles such as radiator grills, interior parts for automobiles, and various display panels. Further, in the removed portion of the coating film, the slit may be formed in a curved shape or a diagonal shape, or may be removed in a dot shape such as a circle in addition to the slit. Further, in this embodiment, the means of removing the coating film by laser was used, but the exposed portion may be formed by masking coating or screen coating. Also in this case, the same operation and effect as those of the above-mentioned embodiment are exhibited.

[0016]

As described in detail above, according to the molded product of the present invention, there is no variation among products as compared with the molded product of the conventional method, and the coating accuracy is remarkably improved. Further, a complicated shape can be easily followed, and a molded product having an excellent appearance can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a back panel according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view taken along the line AA of FIG. 1 in the first embodiment.

FIG. 3 is a view for explaining the manufacturing method according to the embodiment.

FIG. 4 is a partial cross-sectional view taken along the line AA of FIG. 1 in the second embodiment.

[Explanation of symbols]

 1 ... Substrate 2 ... Coating layer 3 ... Slit 5 ... Back panel L ... Laser light

Claims (1)

[Claims] 1. A molded article having a coating layer on the surface of a resin base material, wherein the coating layer has an exposed portion through which the base material is exposed, and the exposure density of the exposed portion is changed. A molded product having a characteristic coating layer.