JPH0112645B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for press molding a synthetic resin conductor.

A conductor made by filling synthetic resin with conductive fibers is
It is used in electromagnetic shielding materials, heating elements, antistatic packaging materials, radio wave receiving antennas, etc. In applications such as electromagnetic shielding materials and antennas, it is necessary to provide uniform and high conductivity, so conductive fibers are usually used.
Mats of filament fibers having a diameter of around 10μ are known. In cases where the conductive layer is present on the surface of a concave surface, such as in a parabolic antenna, such a conductive filament mat is placed on the surface and integrally press-molded using ordinary fiber-reinforced synthetic resin as a supporting material. obtain. however,
The conductive filament mat of the surface layer has drawbacks such as being easily wrinkled and cut due to press pressure. If the conductive filament is wrinkled and unevenly distributed, or if it has cut portions, it may cause leakage of electromagnetic waves and have a large effect on radio wave reception performance, which is a problem that should be prevented.

The present inventors have conducted intensive studies to find a press molding method for synthetic resin conductors having conductive filament mats that does not have the above-mentioned drawbacks. It was found that the problem could be solved by using in combination. That is, the present invention provides a press-molding method for a synthetic resin conductor having a conductive filament mat in its surface layer, which is characterized in that a continuous strand mat is coexisted in the surface layer. It is related to.

Generally, it is important that the conductive layer of the conductor exists uniformly on the surface with a thickness of about 1 mm and at high density. In particular, conductive materials such as parabolic antennas are required to have a smooth surface. Therefore, it is preferable that the diameter of the filament fibers constituting the conductive filament mat is not too large. For this reason, the filament fibers are easily cut during press molding, and countermeasures are required, but this can be effectively prevented according to the present invention. What is Container Strand Matsut?
A strand made of several hundred glass fiber filaments can be cut into approximately 2m lengths or without cutting.
Arrange uniformly in no direction to a predetermined thickness, e.g. 0.5
It is a pine-shaped reinforcing material stacked to ~4 mm and hardened with a binder.

By coexisting such a continuous strand mat in the inner or outer layer of the conductive filament mat layer, it is possible to prevent filament breakage. In a housing material for electromagnetic shielding, the conductive filament mat layer does not necessarily have to be located at the outermost surface, but may be located inside the continuous strand mat layer. Usually, a supporting material layer is often provided together with these layers, and these can be integrally formed by heating and press-forming. As supporting materials, for example,
So-called glass chopped strand pine impregnated with unsaturated polyester resin and thickener.
SMC, a so-called block preformed by blending short fiber reinforcing material, unsaturated polyester resin, etc.
BMC or the like is suitable, and this unsaturated polyester resin transfers to the continuous strand mat layer and the conductive filament mat layer during pressing, and can be heat-cured and integrally molded.

Reinforcing fibers in the support material are not limited to glass fibers, but include carbon fibers, boron fibers, fused silica fibers, silica fibers, alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron carbide fibers, silicon carbide fibers, Inorganic fibers such as asbestos fibers and metal fibers, or natural or synthetic fibers such as hemp, vinylon, polyamide, and polyester may be used. The thermosetting resin is not limited in any way, and unsaturated polyester resins, epoxy resins, phenolic resins, vinyl ester resins, silicone resins, polyimide resins, alkyd resins, thermosetting polyurethane resins, and the like can be employed. In addition, the filament materials of the conductive filament mat include carbon fiber, aluminum fiber, brass fiber, copper fiber, stainless steel fiber, metallized glass fiber, carbon coated glass fiber,
Examples include metallized carbon fibers.

Example 1 A parabolic antenna having a concave surface with a diameter of 800 mm and a maximum depth of 100 mm was press-molded. On the concave surface,
From the side furthest from the concave surface, SMC with a glass content of 25%,
Next, a continuous strand mat (unit weight: 450 g/m ² ) was placed, followed by a glass fiber filament mat whose filament surface layer was coated with aluminum (unit weight: 80 g/m ² ). The molded product after integral molding and solidification had good reflectance, and the aluminum-coated glass fiber filament mat did not have a single break.

Example 2 A paraboloid for a parabolic antenna was obtained in the same manner as in Example 1 except that a continuous strand mat was placed on the outermost surface of the concave surface portion. As a result, the aluminum-coated glass fiber mat did not have a single break, and the reflectance was good.

Comparative Example A paraboloid for a parabolic antenna was obtained in the same manner as in Example 1 except that the continuous strand mat was not arranged. As a result, many breaks occurred in the aluminum-coated glass fiber mat, resulting in a decrease in reflectance.

Claims (1)

[Claims] 1. A method for press-molding a synthetic resin conductor having a conductive filament mat in its surface layer, characterized in that a continuous strand mat is coexisted in the surface layer.