JPH0343881B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing synthetic resin buttons such as buttons for clothing and operation buttons for other electronic devices.

<Conventional technology> Conventional methods for manufacturing resin buttons include casting methods using polyester or acrylic resin as materials, and centrifugal molding methods, but all of these methods are inexpensive because the molds are relatively simple. On the other hand, since it was a single-color molding, it was not possible to mold it in multiple colors with decorative effects such as letters, symbols, and patterns.

Therefore, methods for applying such characters, symbols, patterns, etc. include multicolor injection molding methods such as two-, three-, and four-color injection molding methods, sublimation printing methods, and intaglio transfer printing methods. The two-color molding method will be explained with reference to FIG. 3. The characters or pattern portion 5 are molded in advance with a synthetic resin of a predetermined color in a separate mold, while the inside of the mold that forms the button body is molded in advance. The pattern part 5 is fixed at a predetermined position and the button body 6 is formed of a synthetic resin of a different color from the pattern part 5. In other words, the pattern part 5 is inserted into the button body 6. The same applies to colors, and the number of man-hours depends on the number of colors.
The number of molds, etc. also increases.

Therefore, in this case, the wear resistance can be used for 10 to 20 million times, and the decorative effect is also excellent, but the amortization cost of the molding die is high, and it is difficult to produce high-mix, low-volume production. It is not suitable for printing, and it is not possible to express delicate colored patterns like printing.

For this purpose, sublimation printing is a method that can create subtle colored patterns, but this method uses heat-activated ink to print the desired characters, symbols, patterns, etc. on the base transfer paper or film. ,this
After it is brought into close contact with the specified surface of the button body molded with PBT resin, by heating the contact surface of the transfer paper or film, the heat-activated component in the heat-activated ink vaporizes and spreads to the surface layer of the button body. Penetrates and prints a multicolored pattern.

In this case, it is difficult to print white characters due to bleeding due to seepage, the border lines may blur and become unclear, and cosmetics such as hand creams of the operators (women and women) of computers, word processors, etc. may adhere to the fingertips. However, when this comes into contact with the surface of the button body again, so-called secondary seepage occurs, which causes seepage into the surface layer, further staining the surface.

In addition, for these reasons, the above-mentioned intaglio transfer printing method is more stable, but in this case, after printing specified characters, symbols, etc. on the button body, UV paint (ultraviolet rays) is applied by spray painting method. The coating layer is formed using a cured paint.

However, although the UV ink used for the above coating layer has good abrasion resistance, workability, and is suitable for high-mix, low-volume production, the coating efficiency of the UV paint to the object to be coated is poor, and the UV paint itself is expensive. Therefore, there was a drawback that the product could not be supplied at a low price.

<Problems to be Solved by the Invention> The conventional synthetic resin buttons described above were not sufficient in terms of abrasion resistance, decorative effect, touch feel, clarity of characters (patterns), etc.

SUMMARY OF THE INVENTION It is an object of the present invention to address the above-mentioned drawbacks and provide a synthetic resin button of better quality easily and at a lower cost.

<Means for Solving the Problems> The present invention uses a preformed thermoplastic synthetic resin as a base material, onto which desired characters, patterns, etc. are transferred using an intaglio plate using a heat-drying pigment ink, and then a matting agent is applied. This is a method for manufacturing synthetic resin buttons that is coated with an ultraviolet curable ink containing 2 to 10% of synthetic resin and coated with a transfer exterior.

<Example> First, the most important aspect of the present invention is to apply a coating layer on the outermost side of a base material on which letters, patterns, etc. have been applied using ultraviolet curing (UV) ink mixed with a matting agent such as polyethylene, polypropylene, or silica. The purpose of this formation is to improve abrasion resistance, maintain the clarity of printed colors such as letters and patterns, and provide a good touch feeling to the fingertips. Next, a description will be given with reference to drawings and embodiments.

Example 1 A product base material 1 was formed by injection molding using acrylic resin as a raw material, and a printing ink for heat-dried pads was applied to the surface using a transfer intaglio plate obtained by color separation.
SS-8000 (evaporative drying type = manufactured by Toyo Ink Co., Ltd.)
The transfer layer 2 is formed by printing with hot air at a temperature of 60° C. for 30 minutes.

Next, use UV curable ink such as Nabcoat #1020.
After adding 5% of Aerosil 300 (manufactured by Nippon Aerosil Co., Ltd.) as a matting agent to (manufactured by Nitto Kasei Co., Ltd.) and stirring to make it uniform, one part of the surface of the base material 1 was coated using an intaglio plate with a depth of 30μ. The outer layer 3 was formed by transferring from the surface of the transfer layer 2 to the surface of the transfer layer 2, and irradiating it for 10 seconds with a high-pressure mercury lamp with an intensity of 80 W/nm to obtain a product 4. Note that the product in this case is a button for clothing. Therefore, we conducted a JISH8682 sand fall abrasion test on the above button, and as a result, it was able to withstand 5 minutes without any abnormalities.

Example 2 A product base material 1 was formed using an injection molding method using ABS resin as a raw material, and the surface was printed with ABS Tampo 120 White (manufactured by Seiko Advance Co., Ltd.) printing ink using a transfer intaglio plate with a depth of 20 μ. Transfer layer 2 is dried with hot air at a temperature of 50℃ for 30 minutes.
form. Furthermore, as an ultraviolet curing ink
Add 8% of Aerosil 200 (manufactured by Nippon Aerosil Co., Ltd.) as a matting agent to EXP1719 (manufactured by Fujikin Kasei Co., Ltd.), and stir to homogenize and increase the depth.
Transfer printing is performed on the surfaces of the substrate 1 and the transfer layer 2 using a 25μ intaglio plate, and this is irradiated for 10 seconds from a distance of 20cm with a high-pressure mercury lamp having an intensity of 80W/nm to form a product 4 having an outer layer 3, that is, a personal product. I made a push button for a computer.

Next, the above product was subjected to a JISH8682 sand fall abrasion test for 5 minutes, and no abnormalities were observed.

On the other hand, when a push button obtained by conventional two-color molding was subjected to the above-mentioned JISH8682 sand fall abrasion test for 1 minute, noticeable scratches were found on the button surface. In this way, significant differences were confirmed between the products obtained by the method of the present invention and conventional products.

<Effects of the Invention> When the button obtained by the method of the present invention was compared with a conventional product, a remarkable difference was observed.

In other words, the product manufactured by the method of the present invention has extremely high wear resistance, and as a result, the surface of the product maintains its luster for a long time, even in applications where the product is frequently touched, such as operating buttons on a computer. The printed various function displays do not wear out at all.

In addition, even after long-term use, there is no color bleeding in the characters or patterns, and the clarity does not become unclear as before, allowing it to maintain its beauty for a long time.

Moreover, since the surface is finished very smoothly, the touch feeling is good especially on the operation buttons, etc., and there is no feeling of fatigue on the fingertips.It has excellent wear resistance and decorative effect.Furthermore, it is extremely easy to manufacture and can be provided at low cost. I can do it.

[Brief explanation of drawings]

The attached drawings show an example of a button obtained by carrying out the method of the present invention, in which FIG. 1 is a plan view of the operation button, FIG. 2 is a sectional view taken along line A-A in FIG. It is a longitudinal cross-sectional view showing an example of a color button.

Claims (1)

[Claims] 1. A transfer layer of desired characters, patterns, etc. is printed using heat-drying pigment ink on the surface of a thermoplastic synthetic resin base material such as a copolymer of polypropylene, polycarbonate, acrylonitrile, and butadiene styrene, using an intaglio transfer method. 1. A method for producing a synthetic resin button, which comprises drying the transfer layer, and then printing an outer layer on the transfer layer using an intaglio printing method using an ultraviolet curing ink containing 2 to 10% of a polyethylene, polypropylene, or silica-based matting agent.