JPH0693576A - Method for coloring plastic molded product - Google Patents

Abstract

PURPOSE:To provide the method for coloring a plastic molded product, while imparting gradation to the prescribed part of the plastic molded product, the gradation being produced on the difference in the depths of color. CONSTITUTION:A plastic molded product is immersed in a dyestuff solution having a desired color, and the dyestuff solution and/or the plastic molded product is vibrated to impart the gradation to the plastic molded product at the interface between the dyestuff solution and air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coloring a plastic molded product, and more particularly to a method for coloring a predetermined part of the plastic molded product by giving a blur to a predetermined shade.

[0002]

2. Description of the Related Art When coloring plastics, it is common practice to form a molded product having a predetermined color tone by completely mixing a raw material plastic material with a colorant such as a pigment when molding the plastic. Has been.

It is also known that a pigment or the like is mixed in a raw material plastic material in a non-uniform state to obtain a molded product having a special flow pattern by injection molding.

[0004]

Among the above-mentioned coloring methods, the former method in which a colorant such as a pigment is completely mixed in a raw material plastic material and molding is performed, the obtained molded product has a uniform color tone. As it is a product, there is no interest in the product,
The latter method, which uses incomplete mixing of the colorant, can form an appropriate flow pattern by the flow of the molten resin in the mold by injection, but the density of the flow interface becomes too sharp and soft. It is difficult for the color tone of the interface to be different.

The coloring by these methods has a problem that even if the material is transparent, it becomes opaque due to coloring, and it is impossible to form shading due to blurring at the interface between the colored portion and the non-colored portion. .

[0006]

SUMMARY OF THE INVENTION The present invention is a method for coloring a plastic molded body which solves the above-mentioned problems. The plastic molded body is immersed in a dye solution adjusted to a desired color tone, leaving a predetermined portion. Then, the dye solution and / or the plastic molded product is vibrated to impart blurring to the dye liquid interface of the molded product for dyeing, which is a method for coloring a plastic molded product.

As the plastic material applicable to the present invention described above, thermoplastic resins such as acrylic resin, polystyrene and polycarbonate are preferably used.

The dye used for dyeing is not particularly limited as long as it is capable of dyeing the above-mentioned plastics, but it is insoluble in water, and dyes well on synthetic fibers in a dispersed state. The disperse dye for chemical fiber having the above formula can be preferably used.

For dyeing plastics, the temperature of the dye solution is set to about
The plastic is immersed in the dye solution for several minutes to several tens of minutes at 50 ° C. under normal temperature and atmospheric pressure. It is desirable to repeat this immersion for several tens of times.

In this dyeing, however, the plastic is immersed in the dye liquid leaving a predetermined non-dyed part, and the liquid is vibrated, the plastic is vibrated, or both. By vibrating any of the above, blurring due to the density of the dye is applied to the interface of the dye solution of the plastic. As a concrete method of imparting this blurring, the plastic surface is moved up and down and left and right to make the liquid surface wavy. Move the container itself containing the dye solution to make the surface of the liquid ripple. The vibrating body such as a vibrator is installed in the container containing the dye liquid to make the liquid surface wavy. There is a method such as.

In the coloring method of the present invention, a specific area is masked with a character or a pattern, or a portion other than the character or the pattern is masked and dyed with a dye to obtain a special variation. Coloring is possible.

[0012]

The method for coloring a plastic molded article according to the present invention is such that the plastic molded article is immersed in the dye solution leaving a predetermined portion, and the dye solution and / or the plastic molded article is vibrated to form a dye solution interface. It imparts blurring and is dyed, and it is possible to obtain a colored molded article having a high-class feeling due to the shade of the coloring caused by this blurring.

In particular, the method of the present invention is different from the method of coloring with pigments or paints in that it is colored with a dye. Therefore, when applied to transparent hard plastic, not only the uncolored portion but also the colored transparency of the colored portion can be sufficiently improved. The secured colored molded product can be obtained.

[0014]

The present invention will be described in more detail with reference to the following examples. Example 1 A table knife handle for Western tableware was molded from a transparent acrylic resin. The thick grip of this handle is used with Diacell-iton Fa, an anthraquinone-based disperse dye.
St Red (disperse dye from Mitsubishi Kasei Co., Ltd.) is immersed in the liquid, and the handle itself is moved up and down, left and right to make the liquid surface ripple and hold for about 5 minutes, then pulled up,
After the surface was dried, the surface was immersed again, and the same operation was repeated 10 times.

As a result, the gripping portion is dyed red with the dye, and the coloring of the interface portion due to the immersion in the dye is gradually thinned to obtain a blurred red colored transparent table knife handle. It was The handle of this table knife is
The dyed part and the non-dyed part of the dye gradually changed from transparent red to colorless and were beautiful.

The table knife obtained by attaching the metal part of the knife to this handle was very beautiful with a high-grade feeling due to the blurred part of the red dye.

[0017]

As described above, the method for coloring a plastic of the present invention is simple in that the dye solution and / or the plastic molded article is vibrated by immersing a part of the plastic molded article in the dye solution. It is possible to easily form blurring at the immersion interface of the dye liquid by various methods and to color it. The obtained colored product is unprecedentedly beautiful and has a high-class feeling. .

Further, since the method of the present invention is colored with a dye, there is no bleaching due to use and color transfer to other objects, and it has extremely high safety. Therefore, it is particularly useful for kitchen utensils such as kitchen knives, knives, etc. Various Western tableware, pots, boxes
It can be applied to patterns such as le to increase the added value of these products.

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Claims (2)

[Claims] 1. A plastic molded article is immersed in a dye solution prepared to have a desired color tone, leaving a predetermined portion, and the dye solution and / or the plastic molded article is vibrated to form a dye solution interface of the molded article. A method for coloring a plastic molded article, which comprises applying blurring to and dyeing. 2. The method for coloring a plastic molded body according to claim 1, wherein the plastic molded body is a transparent hard plastic molded body.