JPS6260966B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing decorative molded articles.

Attempts have been made to apply makeup to molded articles. For example, attempts have been made for a long time to apply a pattern to the resulting molded product by printing or the like, or to express the feel of beetroot or marble by kneading various coloring materials in advance. However, in the former case, it is difficult to apply makeup to a three-dimensional shape having unevenness, regardless of whether it is a flat molded product, and in the latter case, it is difficult to always obtain a constant pattern.
There have also been attempts to print on a synthetic resin sheet in advance and integrate the synthetic resin sheet and the molded product during molding. However, in this method, the pattern is formed only by printing on the synthetic resin sheet, and the resulting product has an appearance similar to that of a decorative sheet pasted along the surface of the molded product, and lacks depth.

As a method for applying deep decoration to a molded article, there is also known a method of using a decorative sheet printed on the molded article using penetrating ink. For example, there is a method of printing with a water-soluble ink and then molding using an aqueous composition, or a method of printing with a sublimation transfer ink and then molding using a composition that accepts the sublimation transfer ink. However, this method is limited in its target compositions.

The present invention was made in order to solve the above-mentioned conventional drawbacks, and a decorative sheet is created by providing a printed pattern on a colorless transparent or colored transparent synthetic resin sheet, and then the decorative sheet is placed in an injection mold. A method for producing a decorative molded article is provided, which is characterized in that a molded article is obtained which is integrated with a decorative sheet by molding using a molding resin composition containing colored fibers. This is the main idea.

The present invention will be explained in detail below.

First, in the method of the present invention, a decorative sheet is created by providing a printed pattern on a colorless transparent or colored transparent synthetic resin sheet. As a synthetic resin sheet,
It is preferable to select a material that has good adhesion to the molding resin described below, and should be selected and used because it is easy to print and mold. For example, films or sheets of polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene ternary copolymer resin, acrylic resin, etc. can be used, and can be colorless and transparent to colored and transparent. things are used. It is sufficient that the degree of transparency is such that the surface of the molded product can be visually recognized, but the more transparent the material, the better the ability to express depth, which is the effect of the present invention. The above synthetic resin sheet may be a single layer or a multilayer. In the case of a multilayer, one of the layers may be colorless and transparent, and the other layer may be colored and transparent. Further, a primer layer may be provided on the synthetic resin sheet in order to improve adhesion to a molding resin described later. Furthermore, since the synthetic resin sheet is ultimately molded to match the shape of the molded object, it is preferable to use one with high plasticity so as not to leave any distortion after molding.

The above synthetic resin sheet is printed using a known printing method and ink. The ink used here is selected in consideration of its adhesion to the synthetic resin sheet and the adhesion to the synthetic resin sheet for molding since the printed surface of the synthetic resin sheet and the synthetic resin for molding usually come into contact. In addition, it is necessary to select dyes and pigments that are colorants of the ink that can withstand the heat during molding, which will be described later. Various types of printed patterns can be used, but the resin composition described below is suitable for reproducing wood grain patterns.
It is preferable to use a pattern related to wood grain, such as one that expresses the contours of a wood grain pattern or one that expresses a wood grain conduit, and it is preferable to print using a plate made to imitate precious wood or the like. After printing in this manner, it may be bonded with another transparent film or a transparent protective layer may be provided to protect the printed surface, if necessary.

The decorative sheet obtained as described above is then placed inside an injection mold. A preferred embodiment at this time is to previously shape the decorative sheet along the mold. The pre-forming method may be a method in which the decorative sheet is molded in a separate mold by a molding method using vacuum or compressed air, or a method such as vacuum forming using a molding mold. . These pre-formed molds do not need to match the molding mold in detail; therefore, when a separate mold is used, the separate mold should approximately reproduce the shape of the molding mold. It's enough.

After the decorative sheet is set inside an injection mold, molding is performed using a molding resin composition containing colored fibers.

Various types of colored fibers can be used as the colored fibers used above, but in particular, diameters of 0.1 to 1.0 mm and lengths of 2
If a material with a diameter of about 50 mm to 50 mm is used, the molding resin composition will have a directionality that corresponds to the flow of the molding resin composition during molding, giving an appearance similar to the fiber structure of wood. The molded product is suitable as a base for a woodgrain pattern. Coloring of the colored fibers can be carried out by a known method, and the fibers can be colored to match or differ from the coloring of the synthetic resin constituting the resin composition. Also, if the refractive index of the fiber and the refractive index of the synthetic resin are equal, it will be difficult to distinguish the fibers in the molded product.
When the refractive indexes are different, fibers in the molded product can be easily distinguished, and the three-dimensional effect can be improved by refraction of light. The mixing ratio of the colored fibers in the resin composition can be arbitrarily determined within a range that does not reduce fluidity during molding. The material of the colored fiber used for the above purpose is preferably one that can withstand the molding temperature of the resin, and in this sense, natural fibers such as wool, linen, cotton, rayon, which has high heat resistance among chemical fibers, etc. Kyupura, polynosic, polyester, etc. can be used, but it is preferable to use glass fiber, which has higher heat resistance.

In addition, as the synthetic resin in the above, polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene ternary copolymer resin, polypropylene resin, nylon resin, etc. are usually used.
Anything other than these may also be used.

The present invention has the above-mentioned configuration, and therefore, it can be applied to various molding resins and can be applied to any shape as long as it can be molded, and can be used as a decorative sheet. By using the pattern in combination with the texture of the material itself, it is possible to give a deep and complex appearance, and the method of the present invention is particularly suitable for expressing wood grain patterns.

Claims (1)

[Claims] 1 A decorative sheet is created by providing a printed pattern on a colorless transparent or colored transparent synthetic resin sheet, then the decorative sheet is set inside an injection mold, and then colored fibers are added to create a molding resin. 1. A method for producing a decorative molded article, which comprises performing molding using a composition to obtain a molded article that is integrated with a decorative sheet.