JPS6081900A - Method of producing conductive thermoplastic resin for shielding electromagnetic wave - 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 a method for manufacturing a conductive thermoplastic resin chip used for shielding electromagnetic waves, and particularly for manufacturing the conductive thermoplastic resin chip for shielding electromagnetic waves efficiently and inexpensively. It's about how to do it.

In Western countries, the housings of electronic devices such as computers, word processing sensors, etc. are It is mandatory to use a device that has been treated to shield electromagnetic waves emitted by the electronic device.

The aforementioned electromagnetic shielding of electronic equipment is becoming mandatory in Japan as well, and various electromagnetic shielding methods are being considered.

Shielding of electromagnetic waves like this can basically be achieved by imparting appropriate conductivity to the housing that covers the electronic device, but if the thermoplastic resin that makes up the housing is made of fibrous conductive material, Electromagnetic shielding methods are also well known in which the housing itself is made conductive by incorporating

When manufacturing such a conductive resin molded article, it is common to use a chip mixed with a fibrous conductive material and mold it into a predetermined shape.

The conductive thermoplastic resin chip for shielding electromagnetic waves as described above is conventionally made by inserting a fibrous conductive material, for example, a metal fiber 2, through a width of a molten thermoplastic resin, as shown in FIG.
A thermoplastic resin layer 3 was formed on the surface of the metal fiber 20, and the linear body was cut in the transverse direction to produce a conductive thermoplastic resin chip for shielding electromagnetic waves.

However, according to this method of manufacturing conductive thermoplastic resin chips for shielding electromagnetic waves, only one linear body for manufacturing conductive thermoplastic resin chips for shielding electromagnetic waves can be manufactured at a time, which is extremely difficult. This method has the disadvantage of being inefficient and therefore costly.

The present invention has been made in view of the above points, and by manufacturing a plurality of linear bodies of the thermoplastic resin-coated fibrous conductive material as described above at a time, the electromagnetic wave shielding conductive thermoplastic resin The purpose is to provide a method for manufacturing chips efficiently and at low cost.

Therefore, the method for manufacturing a conductive thermoplastic resin depth for shielding electromagnetic waves according to the present invention involves arranging a plurality of fibrous conductive materials at predetermined intervals in the longitudinal direction of a thermoplastic resin film or sheet, and then Thermoplastic resin films or sheets of the same quality as the sheet are laminated by heat and pressure bonding, cooled, and then longitudinally cut between the rows of the fibrous conductive material to form a linear body covered with thermoplastic resin. At the same time, the linear body is cut into chips in the transverse direction.

According to the method for manufacturing a conductive thermoplastic resin chip for shielding electromagnetic waves according to the present invention, several fibrous conductive materials are placed on a thermoplastic resin film or sheet at predetermined intervals, and this is covered with a thermoplastic resin film or sheet. After cooling and hardening, it is possible to manufacture a plurality of fibrillar conductive material filaments covered with thermoplastic resin at the same time in order to cut the gaps between several metal fibers placed. This method has the advantage that a larger amount of conductive thermoplastic resin chips for shielding electromagnetic waves can be manufactured at one time.

The present invention will be explained in more detail.

In the present invention, first, a thermoplastic resin film or sheet is prepared.

The thermoplastic resin used in the present invention is basically not limited, and resins conventionally used for housings of electronic devices of this type can be effectively used. For example, polypropylene resin, ABS resin, modified p
po resin, polyamide resin, polycarbonate resin, P
It can be a film or sheet made of one or more resins such as PS resin.

On such a film or sheet, multiple rows of tow-like fibrous conductive materials are placed at predetermined intervals.

Such fibrous conductive materials are not fundamentally limited in the present invention. Any fiber may be used as long as it has conductivity. For example, metal fibers made of iron, iron alloys such as stainless steel, aluminum, aluminum alloys, copper, copper alloys, etc., or carbon fibers such as polyacrylonitrile-based, pisody-based, rayon-based, etc. can be used. A thermoplastic resin of the same quality as the thermoplastic resin film or sheet is laminated by heat-pressing onto the film or sheet in which several fibrous conductive materials are placed, and then cooled.

The reason for laminating the thermoplastic resin of the same quality as the thermoplastic resin on which the fibrous conductive material is placed is in consideration of the adhesive properties of the plastic resin.

By cooling in this manner, the films or sheets are bonded to each other and integrated.

The fibrous conductive material of the laminate film or sheet thus formed is cut in the longitudinal direction between a plurality of rows arranged in the longitudinal direction. By cutting in this way, a linear body containing the fibrous conductive material inside can be formed.

By cutting this linear body into a predetermined size in the horizontal direction,
A large amount of conductive thermoplastic resin depth for shielding electromagnetic waves can be manufactured in large quantities.

Next, examples of the present invention will be described.

2 and 3 are schematic diagrams of an apparatus for carrying out an embodiment of the manufacturing method according to the present invention, and in the figure, 22.2
4 is a thermoplastic resin film or sheet, 25 is a hot pressure bonding roll, 27 is a fibrous conductive material, 29 is a laminated film or sheet, 200 is a cooling roll, 210 is a serrated roll, 220 and 230 are cutters, 240 is for electromagnetic wave shielding A conductive thermoplastic resin chip is shown.

The bottom thermoplastic resin film or sheet 22 wound around the storage roll 21 and the semi-molten 1-tube thermoplastic film or sheet 24 just extruded from the extruder 23 are pasted together by a hot pressure bonding roll 25. .

At this time, the fibrous conductive materials 27, 27, 27... wound around the plurality of rolls 26, 26, 26... Several are placed on the film or sheet 22.

The number of fibrous conductive materials 27, 27, 27... and thermoplastic resin films or sheets 22 and 24
The bonding is carried out, for example, as shown in FIG. That is, the fibrous conductive materials 27, 27, 27, . . . from the rolls 26, 26, 26, . be placed.

After forming the rows of fibrous conductive materials 27, 27, 27, etc. at predetermined intervals in this manner, the top film or sheet 24 is laminated and bonded using a hot pressure bonding roll 25.

The laminated film or sheet 29 laminated in this way is guided to a cooling roll 200 and cooled by the cooling roll 200 to harden the thermoplastic resin film or sheet 24, and the thermoplastic resin film or sheet 22 and the fibrous conductive 27, 27, . . . and a top thermoplastic resin film or sheet 24.

The laminated film or sheet 29 integrated in this way
passes through the Giza roll 210. The jagged roll 210 is a roll having sharp serrated protrusions 211 on the surface of the roll, and the protrusions 211 of the upper roll 210a and the lower roll 210b are engaged with each other, and the protrusions 211 are made of fibrous conductive material. Materials 27.27.27...
By installing the fibrous conductive material 27, 27, 27, etc. in the gap between the rows, the rows of the fibrous conductive material 27, 27, 27, etc. are separated from each other, forming a linear body that makes the fibrous conductive material 27 gold. can do.

If it is not possible to cut between the rows using the jagged rolls 210, a cutter 220 may be provided to cut along the grooves formed by the jagged rolls 211. In any case, by cutting the fibrous conductive material 27, 27, 27, .

This linear body is then cut into a predetermined length in the width direction using a cutter 230 to obtain a conductive thermoplastic resin chip 240 for shielding electromagnetic waves.

As explained above, according to the method of manufacturing a conductive thermoplastic resin chip for shielding electromagnetic waves according to the present invention, compared to the conventional method of manufacturing a conductive thermoplastic resin chip for shielding electromagnetic waves, the method of manufacturing a conductive thermoplastic resin chip for shielding electromagnetic waves can produce a plurality of chips in - times. Since a linear metal body containing fibrous conductive material can be manufactured, a large amount of conductive thermoplastic resin chips for shielding electromagnetic waves can be manufactured quickly and the cost can be reduced.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a conventional apparatus for producing conductive thermoplastic resin chips for shielding electromagnetic waves, and Fig. 2 shows an embodiment of the method for producing conductive thermoplastic resin chips for shielding electromagnetic waves according to the present invention. A schematic diagram of the apparatus for
FIG. 2 is an enlarged view of a portion of the device shown in the figure where several fibrous conductive materials are placed. 22... Thermoplastic resin film or sheet (bottom), 24... Thermoplastic film or sheet (top), 27... Fibrous conductive material, 28... Comb teeth, 2
00...Cooling roll, 210...Gizaro λshi. Applicant's agent Masaki Amemiya

Claims (1)

[Claims] +11 A plurality of rows of fibrous conductive materials are arranged at predetermined intervals in the longitudinal direction of a thermoplastic resin film or sheet, and then a thermoplastic resin film or sheet of the same quality as the thermoplastic resin film or sheet is heated. After laminating by crimping and cooling, the fibrous conductive material is cut in the longitudinal direction between the rows to form a linear body covered with a thermoplastic resin, and the linear body is cut in the transverse direction. A method for producing a conductive thermoplastic resin chip for shielding electromagnetic waves, the method comprising: forming a conductive thermoplastic resin chip into a chip shape. (2) The method for manufacturing a conductive thermoplastic resin chip for electromagnetic wave shielding according to claim 1, wherein the cutting in the longitudinal direction is performed in a step including means using a serrated roll.