JPH03234526A - Manufacture of coated metallic plate with dyed pattern - Google Patents

Abstract

PURPOSE:To give a clear pattern to the title metallic plate, by a method wherein ultraviolet rays are applied to the surface of a coating under a state wherein a transparent film to which the pattern is applied beforehand is put over the surface of the coating by bringing the transparent film into contact with the surface of the coating, a cured coating which is changed according to the pattern is obtained and then the pattern is formed by dyeing the coating. CONSTITUTION:A coating 4 of ultraviolet curing paints is applied to a coated steel plate 1, and when it is considered that after the surface of the coating 4 is covered with a transparent film, on which a pattern to be obtained when the pattern is resolved, for example, into red is formed, ultraviolet rays are applied to the coating 4 through the transparent film, only a place other than the pattern of the transparent film is cured completely. When the same is dyed by immersing into a dyeing solution of an aimed color, the place cured completely by the ultraviolet rays is not dyed, only a patterned part (semicured part) is dyed in that color and dyeing into red in accordance with the fixed pattern becomes possible. Similarly a coating 5 of ultraviolet-curing paints is provided newly, which is dyed, for example, in blue. With this construction, the pattern can be formed without using a specific roll or mask.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a dyeing pattern that is used as a painted metal plate for home appliances and building materials, and can be applied to interior building materials that require particularly excellent design. The present invention relates to a method for manufacturing a coated metal plate.

(Conventional technology) In recent years, as the living environment has become more luxurious, homes! High design quality is now required of products and interior building materials.

In the case of a painted metal plate, such as a painted steel plate, it becomes the outer surface of the final product, so the painted surface needs to have a high degree of design. In the following, a painted steel plate will be explained as an example of the painted metal plate.

As for the design properties of painted steel plates, examples include those with patterns and those with improved image clarity.

To improve image clarity, techniques for reducing the surface roughness of the base material and methods using transparent films have already been proposed.

In addition to the conventional printing technology, we have also developed a method of applying patterns using a transfer film (Japanese Unexamined Patent Publication No. 63-28
0627, Japanese Patent Application Laid-Open No. 63-236640), or a method of laminating a resin film on which a pattern has been printed in advance has already been proposed.

(Problem B to be solved by the invention) By the way, the present inventors have proposed a dyeing technique for painted steel sheets in Japanese Patent Application No. 1-254632 with the aim of achieving both image clarity and workability that could not be achieved with these conventional methods. proposed as a number. According to this method, even bake-hardened coated steel sheets can be colored in a relatively short time.

However, in order to impart a pattern using only the dyeing method proposed in Japanese Patent Application No. 1154632, it is necessary to apply a mask paint that can be peeled off after the dyeing process along the pattern before immersion in the dye solution. However, as with other pattern-imparting methods, it is necessary to prepare a roll with a pattern engraved thereon, that is, an engraved roll.

However, there are a wide variety of patterns requested by users, and engraved rolls with different patterns are required. In addition, there are trends in patterns, and it becomes necessary to update the engraved rolls to new ones within a short period of time, such as six months or a year. Of course, even assuming that one pattern is printed in three colors, a roll is required for each color, and when you consider these factors, it is clear that this will lead to a huge increase in cost.

Therefore, an object of the present invention is to provide a pattern forming technique that does not require the above-mentioned engraving roll, and which allows for easy dyeing of pattern changes! An object of the present invention is to provide a method for manufacturing a coated metal plate with a W pattern.

(Means for solving the problem) In order to achieve the above objectives, ■ It is possible to color even a (thermally) cured coating film by a dyeing method, ■ Commercially available color copy machines have a color separation function. The present inventors focused on the basic fact that it is possible to form a color-separated pattern on a film that can transmit ultraviolet rays, such as PH7 film, and as a result of extensive research. (a) The degree of coloring due to dyeing is the crosslinking density (curing degree) of the coating film.
0)) We discovered a new fact that the degree of curing of UV-curable coatings can be easily controlled by the amount of UV irradiation.We continued to study this and created a transparent film with color-separated patterns. After irradiating the UV-curable paint with ultraviolet rays to create a coated metal plate with a simplified or two-dimensional distribution of hardness, it is immersed in a dye solution to partially color it (the less hardened areas are colored). The present inventors have discovered that it is possible to provide a clear pattern by applying the above method, and have completed the present invention.

That is, in the present invention, when curing an ultraviolet curable paint applied to a metal plate surface, the surface of the coating film is irradiated with ultraviolet rays while a transparent film with a pattern applied thereto is brought into contact with and covered with the surface of the coating film. , the production of a painted metal plate with a dyed pattern, characterized in that an effect coating film is obtained in which the degree of curing of the coating film by ultraviolet rays is changed two-dimensionally according to the pattern pattern, and then dyed to form a pattern pattern. The gist is the method.

When applying a multicolor pattern according to the present invention, prepare as many color-separated transparent films as the number of color-separated films,
After completing the irradiation and dyeing of the first color, the coating is applied again and the irradiation and dyeing of the second color is completed, and this process is repeated as many times as necessary.

(Operation) Next, the present invention will be further explained with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of a coated steel plate 1, which is a coated metal plate with a dyed pattern manufactured according to the present invention. .

Although the ultraviolet curing paint may be applied directly onto the plated steel sheet 1, it is usually preferable to apply the coating first and then perform the treatment according to the present invention. That is, the surface of the plated steel sheet 1 may be subjected to surface treatment by chemical conversion treatment such as phosphate, if necessary, and the brimer coat 2 is provided thereon, and then the ground coat 3 is provided thereon.

After the product is manufactured, it is necessary to have sufficient adhesion between the ultraviolet curable paint and the base metal, which will be described later. It is preferable to provide this brimer coat by applying a brimer coat, etc., which may be appropriately selected from known ones.

Further, the reference color, that is, the color of the background of the pattern, can be imparted by using a ground coat.

As the paint for the ground coat, one that has good adhesion to the ultraviolet curable paint is used.

These paint films can be cured by appropriate means such as heating, drying, and electron beam irradiation. These points are already well known in the method of manufacturing coated steel sheets, and the present invention is not limited to specific ones, so further explanation will be omitted.

According to the present invention, the coated steel plate 1 prepared in this way is first coated with a coating film 4 of ultraviolet curing paint, for example, a transparent film (not shown) on which a pattern is formed when decomposed into a red color. ) and then irradiates the surface with ultraviolet rays, only the parts of the transparent film other than the pattern will be completely cured. When dyed by dipping in a dyeing solution of the desired color, only the pattern area (semi-hardened area) is dyed in that color, without dyeing the area that has been completely cured by ultraviolet rays. This makes it possible to dye a red color.

In the same way, a new coating film 5 of ultraviolet curable paint is provided and dyed, for example, blue.

This is repeated as many times as necessary to form a predetermined multicolored pattern on the surface of the steel plate.

The reason why an ultraviolet curable paint is used in the present invention is as follows.

With thermosetting paints, it is not easy to form a two-dimensional, or simple, distribution of degree of curing, and even if only a portion is heated, the boundaries cannot be sharp due to heat conduction.

On the other hand, with electron beam curing paints, similar patterns can be created by using a mask that can change the amount of electron beam transmission. However, just like rolls in the printing method, a wide variety of masks must be prepared. This has no choice but to be an expensive method.

Many types of ultraviolet curing paints are already commercially available, and they may be purchased and used as appropriate in the present invention. For example, a methacrylate oligomer with an appropriate sensitizer such as benzophenone or peroxide can be used.

The coating method may be a roll coater, a curtain flow coater, or a spraying method.

Preferably, the amount of coating each time is sufficient if it is 3 to 10 g/2. If it is too large, the processability will deteriorate, and if it is too thin, the desired effect (coloring density is too faint) will not be achieved.

Next, the reason why the patterned transparent film is irradiated with ultraviolet rays while in contact with the paint surface is to create two-dimensionally different distributions of the degree of curing, and to improve the smoothness of the paint film. This is to improve.

There are no particular restrictions on irradiation with ultraviolet rays, and it is sufficient to irradiate under normal conditions using conventional equipment.

The dyeing liquid may be a general dye commonly used for fibers, etc., and is not particularly limited as long as it can dye an ultraviolet-cured coating film. Further, the treatment time, treatment temperature, etc. may be adjusted as appropriate depending on the type of ultraviolet curable paint or dyeing liquid to be applied.

There are many possible combinations of the type of dyeing liquid and the color dyed with it, and for example, it is sufficient to select an appropriate one from among these combinations depending on the purpose.

The type of metal plate is not limited to any specific type as long as it can be used as a painted metal plate, but generally refers to stainless steel plates, aluminum plates, aluminum-plated steel plates, zinc-plated steel plates, etc.

In addition, the corrosion resistance, workability, and
A clear coating film may be further provided on the dyed coating layer so as to satisfy hardness, stain resistance, etc.

Next, the present invention will be explained in more detail with reference to examples thereof.

Example 1 A conventional hot-dip galvanized steel sheet was used as the base material, and after applying a zinc phosphate chemical conversion treatment (Bonderai 3300, manufactured by Nippon Parkerizing Co., Ltd.) and a commercially available epoxy primer coat to a thickness of 5 μm, this was also commercially available. A white acrylic ground coat was applied to the sample to a thickness of 15 μm, and this was dried and solidified to obtain a test metal coated plate.

The part of the pattern that I wanted to dye red was copied in a single red color onto PET film using a regular color copy machine, and a PET film was created with reduced UV transmittance only for the part I wanted to dye red. . The color used does not have to be particularly red, as long as it can block ultraviolet rays. Similarly, another PET film was created for blue.

Here, a commercially available ultraviolet curable paint (trade name "Seika Beam" manufactured by Dainippon Seika Co., Ltd.) was applied to a film thickness of 5/j on the metal coated plate prepared as described above, and then the above red patterned PET film was laminated. In this state, the coating film was cured by irradiation with ultraviolet rays, and the PET film was peeled off. Only the areas corresponding to the red pattern were semi-cured due to the small amount of ultraviolet irradiation, and the degree of curing depended on the degree of redness, with thinner areas having a greater degree of curing.

The amount of ultraviolet irradiation was 8°-■ using two 80° high-pressure mercury lamps.
They were spaced apart and passed through at a line speed of 5 m/sin.

There are no particular restrictions on the hardness of the paint in the areas where UV rays are blocked, but it must be hardened to a degree that it will not run off when immersed in the dyeing solution. The red color can be adjusted depending on the hardness and the immersion time in the dyeing solution. Adjust the material and film thickness as appropriate.

The metal coated plate with the UV-curable coating film cured according to the pattern in this way was then coated with 10g of red dye (Terra Glue product name manufactured by Ciba-Geigi Co., Ltd.). After being immersed in a boiling water dispersion containing .

Next, for the blue color, apply ultraviolet curable paint,
The steps of UV irradiation and dyeing were repeated.

Through this operation, a patterned painted steel plate having hues of white (the color of the ground coat), red, blue, and purple was obtained, as the cross-sectional structure thereof is schematically shown in FIG. The purple parts were stained with both red and blue.

Example 2 In this example, everything was the same as in Example 1, except that an aluminum-plated steel plate, an aluminum plate, and a stainless steel plate were used as the metal plates, and the base treatment was changed to coating-type chromate treatment (Zinchrome 1415A manufactured by Nippon Parkerizing). A coating was formed and the same dyeing treatment as for galvanized steel sheets was carried out.

Regardless of the type of base metal plate, it was possible to obtain a coated metal plate having a pattern appearance completely similar to that of Example 1.

(Effects of the Invention) Since the present invention is configured as explained above, a pattern can be formed without using a special roll or mask, and it can be used as a pattern forming method for a wide variety of small loft types. , is extremely useful industrially.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a painted steel plate with a dyeing pattern obtained by the method according to the present invention. 1: Plated steel plate 3 Nigerland coat 4: Ultraviolet curable paint (partially dyed red) 5: Ultraviolet curable paint (partially dyed blue) 2 Nibrimer coat

Claims (1)

[Claims] When curing an ultraviolet curable paint applied to a metal plate surface, the coating surface is irradiated with ultraviolet rays while a transparent film with a pattern applied in advance is brought into contact with and covered with the coating surface. A method for producing a painted steel sheet with a dyed pattern, characterized in that a cured coating film whose degree of hardening is changed two-dimensionally according to the pattern is obtained, and then dyed to form a pattern.