JPS6022399A - Electromagnetic wave shielding material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to an electromagnetic wave shielding material.

Quasi-magnetic shielding materials have been prized for use in electronics, etc., and the following proposals have been made to obtain materials with excellent strength and g-shielding properties.

Synthetic resin mixed with conductive fibers (hereinafter referred to as fiber-mixed material).

The nodal properties of this fiber mixture tend to improve as the length of the fibers increases and as the amount of fibers mixed in increases; however, as the length of the fibers increases This makes it necessary to use relatively short fibers.

However, in the case of fiber-containing materials, it is necessary to increase the amount of fibers mixed in, which results in the disadvantage of increasing the weight of the molded product, and furthermore, the presence of resin between the fibers results in poor insulation and resistance. This obstructs electrical conductivity, making it difficult to obtain a material with high shielding properties.

The present invention focuses on continuous fibers or long fibers (hereinafter collectively referred to as long fibers) that are difficult to mold and have not been used.
In order to obtain a 1 magnetic wave shielding material with good molding and kolding properties using 11. It has been discovered that very suitable results can be obtained by stacking fibers, impregnating them with synthetic resin and molding them, and has proposed the present invention.

Conventional materials for magnetic wave shielding are made by mixing four conductive fibers into synthetic resin, so there is no non-conductivity (non-conductivity) between the conductive fibers.
In contrast, in the present invention, conductive long fibers are stacked one on top of the other, so that the fibers are bound to each other. It is thought that shielding performance will be greatly improved because it can be held and an electromagnetic closed circuit is formed.

Furthermore, the long fibers are made of synthetic resin, and the molded product is made by infiltrating the resin, but since the synthetic resin penetrates into the gaps between the stacked long fibers, there is a risk that the bonding state may be impaired. There is no such thing as molding, and molding can be done reliably.

Next, the present invention will be explained in more detail.

The conductive fibers 7 are not particularly limited, but aluminum fibers, brass fibers, steel fibers, etc. are suitable. And 1. Continuous fibers or long fibers are used as the fibers.

On the other hand, as the synthetic resin, polyester resin, epoxy resin, etc. can be suitably used.

When molding, for example, a plurality of long fibers are dropped onto a moving endless belt to be deposited in a spiral manner on the belt, and then a plurality of long fibers are further dropped θ at intervals. A cloak-like object having a desired thickness is formed by this.

A synthetic resin is infiltrated into this mat-like material by an injection method or a molding compound method (hereinafter referred to as SMC method) to form a substrate. Note that the substrate formed by the SMC method is charged into a mold and molded into a desired shape, if necessary.

In the substrate constructed as described above, the tips of the fibers may protrude from the surface of the synthetic resin due to fluff of less than 4 feet. When you touch the tip of this fiber, it becomes energized,
Since this is dangerous, a good way to prevent this is to further coat the entire surface of the board with a non-conductive synthetic resin.

Note that 2 to 0 volume parts of the fibers are suitable for 100 volume parts of the substrate.

If the amount of fiber is 20 parts by volume or more, it will be difficult to obtain a good molded product, and if it is less than 2 parts by volume, there will be a problem that the electromagnetic wave nordability will not reach a practical level.

Example: Interwoven steel fibers are piled up to form a mat, which is inserted into a mold, and the injection method is used to infiltrate polyester resin into the volume to form a substrate with a thickness of 3. The entire surface of the substrate was completely coated with H+) ester resin.

It had good shielding properties and sufficient strength.

Claims (1)

[Claims] An electromagnetic shielding material characterized by stacking conductive long fibers, infiltrating them with synthetic resin, and molding them.