JPS61167477A - Two-tone painting method - Google Patents

Abstract

PURPOSE:To paint an automotive body excellently in terms of design and performance by subjecting said body to primer coating then to finish coating of an intermediate paint to two tones and coating once a low-concealing finish paint over the entire surface of the coated film. CONSTITUTION:Intermediate coated films 3, 4 are formed by two-tone finish coating on the outside plate 1 of the automotive body on which the primer coated film 2 is formed in a method for subjecting the outside plate of said body to the two-tone finish coating. The low-concealing finish paint coated film 5 is then formed over the entire surface of the films 3, 4. As a result, painting, better in terms of design and performance than the conventional method is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-tone coating method. More specifically, the present invention relates to a method for applying a two-tone finish to the exterior of an automobile body, particularly in order to improve the appearance of the vehicle body, to provide a brightly painted color, and the like.

[Conventional technology]

Two-tone paint is applied to the exterior of the car body in order to enhance its beauty and improve its appearance, and pearl mica two-tone paint, which is a combination of this paint and pearl mica paint, is applied. As is well known.

As a typical example of such a painting method, conventional pearl mica two-tone painting is explained in the order of steps as follows: 1. Applying an undercoat paint to the entire automobile body that has been pre-treated in the undercoating process; and dry.

2. Intermediate coating process Using gray intermediate coating paint, apply it to the exterior of the car body, bake it, and sand it with water. At this time, the interior panels of the vehicle body may also be painted in color, and then dried.

3. First color base painting step A color base paint (first top coat color) of the two-tone B/A colors, that is, a colored solid paint, is applied and baked.

4. Mica-based painting process Apply mica-based paint.

5. Apply clear paint to the mica base coating film that is formed before the clear coating process,
and dry.

6. Masking process Mask the A color area with masking means such as masking tape or masking paper to prevent B color paint from adhering to the A color area in the subsequent second color base painting process.

7. Second color base painting step A color base paint of color B (second top coat color) of the two-tone B/A colors is applied and baked.

8. Mica-based painting process Said step 4. Same as .

9. Clear painting process Said step 5. Same as .

10. Masking means peeling process Now that the series of painting steps have been completed, the used masking means is peeled off to obtain the desired coating system.

[Problem that the invention seeks to solve]

However, in the two-tone painting method described above, as can be understood from the above, the color base + mica base + clear painting process is repeated twice during the top coating process, which increases the amount of paint used and causes a large amount of drying. n energy is required. Furthermore, with this method, there is a noticeable difference in film thickness at the two-tone boundary, so
It doesn't look good, and the paint film may peel or chip at the stepped areas. Furthermore, in this method, if the adhesion between the clear coating film and the second color base coating film thereon is not good, delamination may occur between these coating films.

As a method that can solve these problems, the applicant first applies a two-tone color base paint to the object to be painted, especially an automobile body, which has undergone a series of preceding painting processes, such as undercoating and intermediate coating, and then applies a two-tone color base paint. He was the first to discover a pearl mica two-tone coating method, which is characterized by sequentially applying mica-based paint and clear paint to the entire surface of the two-tone paint film, and has already applied for a patent (patent application filed in 1973).
No. 9-214252). Although this improvement method is said to be effective in improving the step difference at the closing part and the interlayer adhesion, further improvements are desired.

For example, in the conventional two-tone painting method, the effect is largely transferred to the top coat, so it naturally requires a high level of performance of the top coat, such as durability, water resistance, and color development of the color base. . moreover,
As a top coat, it is necessary to completely hide the color of the intermediate coat underneath, so the color must be muddy, and it is inevitably impossible to provide a highly saturated, non-turbid paint color. Moreover, it is not possible to design paint colors with new design effects.

That is, the present invention aims to solve the problems of the conventional techniques listed above and provide a new two-tone finish coating method that is superior in design and performance to conventional methods. It is.

[Means for solving problems]

The present inventors have recently discovered that when applying a two-tone finish coating to the outer panel of an automobile body, by combining an intermediate coat and a top coat to create a two-tone finish, a new color gamut that could not be obtained in the past can be achieved, solving the problems described above. It has been discovered that this can be provided without any points.

In the two-tone painting method of the present invention, after applying a primer coat to an automobile body, a two-tone finishing coat is applied to the outer panel of the automobile body, and then a low-hidden top coat is applied to the entire surface of this two-tone finishing coating. It is characterized by including a step of painting in one step.

In the method of the present invention, it is essential that the top coating used has low hiding power or dichroism, and therefore contains interference mica or colored mica alone or a combination of the mica and pigment. Top coats such as these are useful.

The intermediate coating used to form the two-tone pattern can be arbitrarily selected from among conventional intermediate coatings depending on the desired color, final specifications, etc. For example, it is possible to use an intermediate paint that is achromatic and has different lightness between the first paint color and the second paint color, such as a two-tone color of white and black. Alternatively, colors whose hue, brightness, and saturation are changed by adding a colored pigment can also be used as the first coating color and the second coating color. In selecting an intermediate paint, the properties of the paint material must also be considered.

This is because the intermediate coating must not only satisfy the performance conventionally required of intermediate coatings, but also must guarantee excellent interlayer adhesion. However, in the case of such a two-tone intermediate coating, the degree of freedom in material design is greater than in the case of a conventional two-tone top coating.

[Effect]

In the present invention, as a result of using a low-hidden topcoat paint, a state in which the two-tone color of the intermediate coat is achieved can be achieved, and therefore, a coating that is close to that obtained by mixing the color of the topcoat and the color of the intermediate coat can be obtained. can create colors. In this case, for example, make the middle coating two-tone with complementary colors,
When a similar color is used for the topcoat, it is possible to obtain a two-tone color that is extremely sharp and clear, and provides a new design that has never existed before. Furthermore, the use of paints containing dichroic pigments such as interference mica in the topcoat can provide particularly strikingly novel designs. This is because dichroic pigments exhibit an interference color in reflected light and a complementary color in transmitted light, so their color changes depending on the viewing direction, but this dichroism also changes subtly depending on the color of the base. It is. For example, if the intermediate coating is two-tone white/black, the transmitted light (complementary color) will be diffusely reflected on the white area, so the interference color will appear strongly only near the specular reflection, and the interference color will appear in other areas. The complementary color of the transmitted light reflected by the base is mixed again, resulting in a non-colored finish.On the other hand, on the black area, the transmitted light (complementary color) is absorbed by the black of the base, so it appears in all directions. The result is a finish in which interference colors are visible. Therefore, a completely new two-tone finish that can only be obtained by using a two-tone base is provided.

When interference mica is used as an overcoat as described above, the base need not be two-tone white/black, but may be colored in another color. In such cases, the characteristics of interference mica appear even more strongly, and the color changes further depending on the viewing direction.
It becomes pleochroic. As mentioned earlier, this is a revolutionary paint color design method that was impossible to implement with the conventional method of producing color with an overcoat.By the way, with the conventional method, interference mica and Since colored pigments are contained in the same paint, reflection and absorption occur due to the colored pigments, which destroys the characteristics of mica, making it impossible to achieve the desired color development.

〔Example〕

Next, a preferred example of the method of the present invention will be explained with reference to the accompanying drawings.

FIG. 1 is an enlarged schematic cross-sectional view along line I-'I of the automobile body shown in FIG. 2 after being two-tone painted according to the present invention. From this figure, on the steel plate 1 that makes up the car body,
An undercoat film, that is, an electrodeposition (ED) paint film 2, an intermediate paint film 3 of color A (first paint color) of the two-tone B/A colors,
It will be understood that the intermediate coat film 4, top coat film 5, and clear coat film 6 of color B (second paint color) among the two-tone B/A colors are sequentially coated.

The coating system shown in FIG. 1 can be advantageously obtained through a series of steps as follows: 0. Pre-treatment process An unpainted body steel plate manufactured at an auto body shop is subjected to a pre-treatment process. A phosphate film is formed by cleaning, degreasing and chemical conversion treatment.

1. Undercoat process: The car body steel plate 1 on which a phosphate film (not shown) is to be formed is subjected to ordinary electrodeposition coating to form an undercoat film 2 with a film thickness of about 15 to 25 μm.
form and dry.

2. First intermediate coating process Color A (first coating color) of the desired two-tone B/A colors
A color intermediate coating 3 having a film thickness of about 20 to 40 μm is formed by applying and baking the intermediate coating on a selected area on the undercoat 2 by a conventional method.

3. Masking process Masking is performed to form a parting line and to prevent the B color paint from adhering to the desired portion of the A color intermediate coating film 3 in the next second intermediate coating process.

This step can be advantageously carried out by applying appropriate masking means such as masking tape or masking paper to the required portions of the A-color intermediate coating film 3.

4. Second intermediate coating process Under the above-mentioned masking conditions, apply and bake the intermediate coating of color B (second coating color) of the two-tone B/A colors to a film thickness of approximately 20~20cm. A B color intermediate coating film 4 of 40 μm is formed.

5. Masking means peeling step After forming the color B intermediate coating film 4, the used masking means is peeled off. After water sanding, the B/A two-tone intermediate coat is completed.

6. Top coating process: Apply a low-hidden top coat that shares the BZA color to the entire surface of the formed two-tone intermediate coat to a film thickness of approximately 10 to 25 μm.
A top coat film 5 is obtained. In addition, this top coat painting process is
It may be carried out with one coat and one bake, or may be carried out with two coats and one bake.

7. Clear paint process: Apply clear paint to the entire surface of the top coat film 5 to be formed first, and then dry. The thickness of the clear coating film 5 to be formed is:
Preferably, it is about 20-40 μm.

The implementation of the method of the invention will then be illustrated by the following preferred examples.

In this example, black was used as the A-color intermediate coat (3 in Figure 1), and white was used as the B-color intermediate coat (4 in Figure 1). After white/black two-tone painting, baking, and water sanding, topcoat paint containing interference mica pigments (all interference mica pigments S series manufactured by Nihon Koken Co., Ltd.) as listed in Table 1 below is applied using a minibell paint sprayer. was used to spray the two-tone intermediate coat. The topcoats used here each consisted of 70% by weight acrylic resin and 30% by weight melamine resin and each contained 10 pwc of the interference mica pigments listed in Table 1.

In addition, the coating viscosity in this case is 15 sec/20
'C,94FC. After applying the top coat, I allowed about 3 minutes of flash time, then sprayed another layer of clear paint, and baked it. In each case, a bright, novel two-tone coating color as described in Table 1 was obtained. The two-tone separation was also good, and there was no glabellar peeling.

10- Table example Interference mica Color A (black) Color B (white) - One plate and --- Golden plate one opposite ■ Length ■ Plate 1 Interference blue
Blue Blue White Mica 2 Interference Pink Pink Pink White Mica 3 Interference Green Green Green White Mica 4 Interference Red Red Red White Mica 5 Interference Bio Purple Purple White Mica 6 Interference Yellow Yellow Yellow White Mica repeated. However, in the case of this example, green was used as the AA color intermediate coating film, and red, which is a complementary color to A color, was used as the B color intermediate coating film.

For the top coat, a paint containing the same type of interference red mica (described above) was used. The finish was good, and the red color in the specular reflection direction appeared on the B color, resulting in an extremely clear color.

The procedure described in Example 1 above was repeated. However, in the case of this example, in place of the interference mica pigment used in the topcoat in Example 1, colored mica as listed in Table 2 below (all Exterior Gerade manufactured by Marl) was used in an amount of 10 pwc each. used. Although colored mica does not have dichroism like interference mica pigments, a novel two-tone finish that was mixed with the base (black/white) was obtained.

8 Colored Red Mica 9 Colored Red Brown 10 Colored Copper 11 Colored Gold 12 Colored Bronze 13 Silver Mica Examples 14 to 17 The procedure described in Example 1 above was repeated. However, in the case of this example, a combination of mica and pigment (10 pw of mica each) was used instead of the interference mica pigment used in the topcoat in Example 1.
c and 5 pwc of pigment) (see Table 3 below) were used.

All of the pigments used in this example had high transparency and did not muddy the color. In each case, a novel two-tone finish was obtained that was unprecedented and different from the finishes of Examples 1 to 13.

Member Yul 5 Ekoza ■ Natsume! Platinum■I歿14 Colored red mica Perylene 15 White mica Phthalocyanine blue 16
White Mica Carbon Black 17 Interference Blue Mica Phthalocyanine Blue [Effects of the Invention] According to the present invention, first, it is possible to provide a novel and bright two-tone coating color that has not been seen before. Further, according to the present invention, there is no step difference in the parting line portion, so a good finish can be achieved. Furthermore, according to the present invention, inconveniences such as glabellar peeling can also be eliminated.

[Brief explanation of drawings]

1 is a schematic enlarged cross-sectional view taken along line 1-I of an automobile body painted in two-tone according to the present invention shown in FIG. 2, and FIG. 2 is a schematic side view of the automobile body painted in two-tone. It is. In the figure, 1 is a steel plate, 2 is an undercoat film, 3 is an A color intermediate coat film, 4 is an 8 color intermediate coat film, 5 is a top coat film, and 6 is a clear paint film. 2nd batch

Claims (1)

[Claims] 1. A method for applying a two-tone finish coating to the outer panel of an automobile body, in which an intermediate coat is applied as a two-tone finish to the outer panel of the vehicle body after the undercoating, and then the entire surface of the two-tone finish coating is applied. A two-tone painting method characterized by comprising the step of applying a low-hidden topcoat to the surface. 2. Apply an intermediate coat of color A of the two-tone B/A color to the selected area of the outer panel of the car body after the primer coating, and dry it, and then apply color B under the masking of the color A paint film. The two-tone coating method according to claim 1, wherein an intermediate coating is applied and dried, and a low-hidden top coating is applied over the entire surface of the formed two-tone finishing coating and dried. 3. The two-tone coating method according to claim 1 or 2, wherein the top coat contains interference mica or colored mica alone, or a combination of the mica and a pigment.