JPH08183057A - Manufacture of resin-molded product having metallic tone - Google Patents

Abstract

PURPOSE: To control the orientation of metallic foils on the surface of a molded product and give depth to the external appearance of the product in molding resin with which metallic foils are mixed and in manufacturing a resin-molded product having the appearance of a metallic tone. CONSTITUTION: In the manufacture of a resin-molded product having a metallic tone, wherein metallic foils 7 are mixed with resin 6 to be molded and give the appearance of a metallic tone to the resin-molded product, resin molding is performed by inserting a film 4 into a cavity of molds 1, 2 when the resin is molded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding method in which a resin having gloss such as a metal foil is mixed with a resin, and the resin mixed with the metal foil is molded into a molded product.

[0002]

2. Description of the Related Art Conventionally, as a filler for imparting a glossy appearance to a thermoplastic resin, there have been known many molded products obtained by mixing and melt-molding metal particles, metal foil and the like. For example, in Japanese Patent Laid-Open No. 61-159453, an average particle size of 35
A resin molded article, characterized in that it contains 0.1 to 15 parts by volume of glossy particles having an average shape ratio of 0.125 to 1 and a thermoplastic resin and glossy particles of 100 to 100 parts by volume in total. It is shown.

It is said that the resin molded product having the above composition has no weld mark, is low in cost, and is advantageous in terms of productivity.

Such a resin molded product containing the glossy member has a uniform metallic or metallic appearance on the entire surface (hereinafter, the resin molded product including the glossy member is referred to as a metallic tone resin molded product). .) So, as its use,
It can be used as a high-grade molded product such as a camera exterior product.

In these metallic resin molded products, when a flat member such as a metal foil is used as the glossy member mixed with the thermoplastic resin, the resin molded product is molded by injection molding. The metal foil on the surface of the product is oriented in the direction in which the plane of the metal foil can be seen from the outside as shown in FIG. When observed in a sectional view showing the flow of resin in the cavity, as shown in FIG. 5, the metal foil 13 surrounded by the resin 12 near the resin molding die 11 is shown.
Are oriented in the same direction. As shown in FIG. 6, when the resin flows in the cavity of the resin molding die 11, the resin near the die is deprived of heat by the die to form the solidified layer 14. . Further, the resin 15 in the portion near the center of the cavity and away from the mold flows without solidifying. At this time, as shown in FIG.
Is between the solidified layer 14 and the fluid resin 15, the end of the metal foil 13 on the solidified layer 14 side is fixed together with the solidified layer 14. On the other hand, the end of the metal foil 13 on the side of the fluid resin 15 tends to flow together with the fluid resin 15 in the traveling direction of the resin. As a result, the metal foil 13 rotates around the end fixed by the solidified layer 14, and the fluid resin 1 of the metal foil 13 rotates.
The rotation stops when the end on the 5 side comes into contact with the solidified layer 14, and the state is fixed in that state. For this reason, the direction of the metal foil on the surface of the molded product is oriented in one direction. Therefore, when observing the surface of this molded product after resin molding, as shown in FIG. 4, it can only be seen that metal foils having the same rectangular shape are lined up, which gives a deep appearance to the molded product. I couldn't.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention provides a metallic resin molded product which is capable of increasing the depth of the appearance of the product such that the metal foil or the like on the surface of the metallic resin molded product is not oriented in a certain direction. The technical problem is to provide a manufacturing method.

[0007]

The technical means taken in the present invention to solve the above technical problems is to form a resin molded product by mixing a resin with a metal foil, a metal fiber and mica. In the method for producing a metallic resin molded article having a metallic appearance, in the resin molding, a film is previously inserted into the cavity of the resin molding die, and then the resin molding die is closed. That is, a method for producing a metallic resin molded article, which is characterized in that resin molding is performed by using

[0008]

The reason why the solidified resin and the molten resin are mixed in the cavity of the mold is that the solidification speed of the resin in the cavity varies depending on the location. That is, the resin flowing on the side closer to the mold has a faster solidification rate because it is cooled more quickly by the mold. On the other hand, the resin distant from the mold has a slow solidification rate because cooling by the mold is slow. Therefore,
If the distribution of the solidification rate on the same plane in the cavity is reduced, the orientation of the metal foil on the resin surface will be reduced.

According to the above technical means, in the method of manufacturing a metallic resin molded product, when resin molding is performed,
It is considered that the problem can be solved by inserting a film in the cavity of the mold in advance and then performing resin molding, or performing film insert molding. That is, by interposing the film between the mold and the resin, the heat transfer from the resin to the mold becomes poor. Therefore, the difference between the solidification speed of the resin on the side close to the film and the solidification speed of the resin on the part away from the film becomes small, and the molten resin solidifies almost uniformly. Thereby, the orientation of the metal foil is suppressed on the surface of the molded product after resin molding, and a metallic resin molded product having a deep appearance can be molded.

[0010]

1 is a schematic sectional view of an apparatus for producing a metallic resin molded product by injection molding according to an embodiment of the present invention. The resin molding die includes a fixed die 1 and a movable die 2. The movable mold 1 is provided with a runner 8 for feeding the resin from the injection molding machine 3 into the cavity of the mold. The film 4 is fixed by a pin 5 provided on the movable mold 2.

As for the molding method, first, the film 4 is attached in the cavity of the fixed mold 2 while the mold is opened, and the pin 5
The film 4 is fixed in the cavity of the fixed mold 2 by.

After that, the mold is closed, the molten resin is injected from the injection molding machine 3 into the mold, and after the completion of filling, the mold is opened through a holding pressure and cooling process, and the molded product is taken out.

As a molded product, in this embodiment, a center pillar (length: about 450 mm, which is an automobile part,
Width: about 50 mm, thickness: about 3 mm) was molded.

Polycarbonate resin (trade name: Iupilon, manufactured by Mitsubishi Gas Chemical Co., Inc.) 95 to 97 is used as the resin.
Injection molding was performed under the molding conditions shown in Table 1 using a material composed of 3% to 5% by volume of metal foil consisting of aluminum foil and 3% by volume.

[0015]

[Table 1]

As the film, a film (trade name: Iupilon sheet, thickness: 0.5 mm) made of polycarbonate resin manufactured by Mitsubishi Gas Chemical Co., Ltd. was used. Further, in the present embodiment, since the film and the resin material are the same polycarbonate resin, both are easily melt-bonded and the surface of the product is formed by the film.

Observing the surface of the metallic resin molded product molded by the film insert molding method based on the molding conditions of Table 1, the metal foil on the surface of the molded product was randomly fixed as shown in FIG. No orientation in a certain direction was observed. As is clear from FIG. 2 showing the flow of the resin in the cavity, the resin on the side closer to the film 4 has a slower solidification rate due to cooling from the mold than in the case without the film. Therefore, the difference in the solidification rate between the resin near the film and the resin near the center of the cavity is reduced, and the metal foil is fixed in a random state. On the other hand, the resin near the die on the side where the film is not inserted has a high solidification speed, and therefore the difference in solidification speed with the resin near the center of the cavity is large. That is,
As mentioned in the conventional problem, one end of the metal foil near the mold is fixed first, and the other end is not fixed, so the metal foil rotates around the fixed end, The metal foil is oriented in a certain direction.

In the case of the present embodiment, if the design surface of the molded product is set as the side where the film is inserted, the metal foil is randomly fixed on the surface of the product, and a product with a deep appearance can be provided. it can.

[0019]

The present invention has the following effects.

According to the present invention, in the method for producing a metallic resin molded product, which is obtained by mixing a metal foil, a metal fiber and mica into a resin to form a resin, and giving the resin molded product a metallic appearance. At the time of molding, a film was previously inserted into the cavity of the resin molding die, and then the mold was closed to perform resin molding. By inserting the film in the cavity,
The cooling rate of the resin in the vicinity of the mold was reduced to reduce the difference in the cooling rate with the resin in the vicinity of the center of the cavity. As a result, the metal foil in the vicinity of the surface of the molded product was randomly fixed, and the orientation in a certain direction was suppressed, so that the depth of the product appearance could be increased.

In the embodiment of the present invention, the film material and the resin material are the same material (polycarbonate resin in the case of the embodiment). As a result, the film and the resin are easily adhered, so that the film can be used as a product while being adhered to the resin, and the inserted film can be effectively used without being discarded.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the flow of resin in the cavity of the mold in the example of the present invention.

FIG. 3 is a surface appearance of a resin molded product in an example of the present invention.

FIG. 4 is a surface appearance of a resin molded product according to a conventional technique.

FIG. 5 is a cross-sectional view showing a flow of resin in a cavity of a mold according to a conventional technique.

FIG. 6 is an enlarged cross-sectional view of the resin in the cavity of the mold showing that the metal foil is oriented on the resin surface in the prior art.

[Explanation of symbols]

 1 movable type 2 fixed type 3 injection molding machine 4 film 5 pins 6 resin 7 metal foil 8 runner

Claims (1)

[Claims] 1. A method for producing a metallic resin molded product, comprising mixing a metal foil, a metal fiber, and mica into a resin to form a resin, and giving the resin molded product a metallic appearance.
When performing the resin molding, a film is inserted into the cavity of the resin molding die in advance, and then the resin molding die is closed to perform resin molding, and a metallic resin molded article is manufactured. Method.