JPH0192685A - Outer packaging component for timepiece - Google Patents

Abstract

PURPOSE:To improve the turbidity and color irregularity of a molded product by using color glass fiber as a reinforcing material for plastic. CONSTITUTION:The color glass fiber is used as the reinforcing material for plastic. Then light incident on the glass fiber is diffused and reflected irregularity because of the synergetic effect between the red of a color master batch and the red glass fiber as the reinforcing material, so that the light is seen as red light. Consequently, the turbidity and color irregularity of the molded product are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exterior part for a watch manufactured using colored glass fiber as a plastic reinforcement material.

[Conventional technology]

It is well known that conventionally, in order to strengthen plastics, plastic is used as a matrix and reinforcing materials are combined with this to give it excellent properties, and it is widely used as reinforced plastics or engineering plastics. The base material of this reinforcing material may be in the form of powder, fiber, whiskers, cloth, etc., and the material may be a polymeric material such as glass, carbon, metal, or aromatic aramid. Among these, thermoplastic resins, glass fiber composite materials (GFTP) reinforced with glass fibers such as glass chopped strands and glass milled fibers, and charcoal short fibers are being used as plastic materials for watch exterior parts. Using carbon fiber composite material (OFTP) as a reinforcing material, watch cases and bands are made by injection molding, which is highly productive, economical, and easy to achieve high molding precision. The glass fiber used as the reinforcing material is colorless, and the plastic is colored by adding a color masterbatch. In recent years, there has been a remarkable diversification of colors, and because plastic can be easily colored, it is also actively used in the exterior parts of watches.

[Problem that the invention seeks to solve]

However, with the above-mentioned conventional technology, depending on the design of the watch case, for example, the glass fibers may be exposed to the surface even under the best injection molding conditions, and as a result, despite the use of red or black colorants, The problem is that the case looks cloudy or uneven, detracting from its appearance as a watch case.

The present invention is intended to solve these problems, and its purpose is to improve the cloudiness and unevenness caused by molding and to provide a product that is comparable as an exterior part for a watch.

[Means for solving problems]

The exterior part for a watch according to the present invention is characterized in that colored glass fiber is used as a plastic reinforcing material.

Examples of matrices for thermoplastic reinforced plastics and engineering plastics include polyamide, polycarbonate, polyacetal JAB Stl resin, polyethylene terephthalate, and polypropylene. Glass fiber and carbon fiber are added as reinforcing materials to improve mechanical strength, heat resistance, chemical resistance, and two-dimensional stability.

In the same way, plastic materials for watches use glass fiber composite materials (GFTP) and carbon fiber composite materials (CFTP), and color masterbatches are added to achieve colored molded products. However, as mentioned in the ``Problems to be Solved by the Invention'' section, a phenomenon occurred in which glass fibers (GF) floated to the surface of the molded product and the color tone of the GF part appeared different from that of the normal part. Since the added glass fibers are transparent when observed under a microscope, it was found that the incident light rays were diffused and reflected diffusely, resulting in a cloudy or uneven appearance.

Therefore, according to the present invention, the same color as the color masterbatch,
Alternatively, glass fibers of a similar color are added to improve the cloudiness and color unevenness of the molded product.

The following will explain based on examples.

〔Example〕

(1) Using 7% polycarbonate (PO) as a base matrix, 1 t of PC red color master batch diluted 10 times as a red coloring agent and 2 t of red glass fiber as a reinforcing material were kneaded, and 106 pellets were made using a pelletizer. Molding conditions are resin temperature 290℃, injection pressure 110℃.
C1'/, 11 e Injection speed 1000/, injection time 2
．． 5 See, cooling; 200 cases for watches at 9° C. were molded for 15 seconds. The molded product was inspected for cloudiness and color unevenness, and it was found that the finish was comparable to that of an exterior part for a watch. In other words, due to the synergistic effect of the red color of the color masterbatch and the red glass fiber of the reinforcing material, the incident light on the glass fiber is diffused and appears red even when reflected diffusely, and there is no cloudiness or color unevenness phenomenon, making it suitable for use as a watch case. The appearance has been improved.

In addition, the mechanical strength is ASTM, D63B, D790, D2
As a result of measurements based on 56, all of them had the same strength as those molded from natural (colorless) glass fiber.

(2) Polycarbonate (PC) 7KP was used as a base matrix, PC blue color masterbatch was diluted 10 times as a blue coloring agent, blue glass fiber was kneaded as a reinforcing material, and 109 pellets were made using a pelletizer. 200 pieces were molded under exactly the same molding conditions as in Example (1). The color tone of the molded product showed little change due to heating during melting, which was improved by adding a very small amount of additives to the color masterbatch. Therefore, there was no cloudiness or color unevenness that occurred with conventional techniques, and the result was a good finish for a watch case.

(3) Polyethylene terephthanate (pH!T)
Using 7t as a base matrix, 1t of black colorant color master batch diluted 10 times, and black glass fiber 29 as a reinforcing material were kneaded, and 1015 pellets were made using a pelletizer. The molding conditions were a resin temperature of 300° C., an injection pressure of 650 terres, an injection time of 2.5 seconds, and a cooling time of 17 seconds to mold 200 watch cases.

The molded products were inspected for cloudiness and color unevenness, and all of them had a finish comparable to that of a watch case.

〔Effect of the invention〕

As described above, according to the present invention, by using colored glass fiber as a reinforcing material for plastic, cloudiness and color unevenness caused by raised glass fibers, which could not be avoided under the molding conditions, can be avoided with color masterbatch. The present invention uses reinforced plastic that can be improved through synergistic effects and can be used as an exterior part for watches with a good finish.

We have talked about glass fiber, which is actively used as a reinforcing material for engineering plastics, but regarding glass beads that are also used as a reinforcing material, we can obtain the same effect in coloring plastics by using magenta glass beads. It is. Furthermore, the present invention is applicable not only to exterior parts for watches, but also to items that can be colored to give a beautiful appearance, and is not particularly limited to exterior parts for watches.

that's all Applicant: Seiko Epson Corporation

Claims (1)

[Claims] Exterior parts for watches that use colored glass fiber as a plastic reinforcement.