Resin molded product for electric parts and manufacturing method thereof

Abstract

A molded resin for use as electrical parts which is excellent in heat resistance, mechanical properties, electrical properties, dimensional stability, flame retardancy, and moldability and can be produced by ordinary injection molding. A resin composition comprising a thermoplastic polymer, a crosslinking agent comprising a polyfunctional monomer or oligomer having an unsaturated group at an end of the backbone, an inorganic filler, and reinforcing fibers is molded and solidified. Thereafter, the thermoplastic polymer is crosslinked by irradiation with a radiation. The crosslinking agent is adsorbed beforehand onto the inorganic filler in an adsorption step and then kneaded together with the thermoplastic polymer, reinforcing fibers, etc. The composition is irradiated with a radiation after injection molding.

Description

technical field [0001] The present invention relates to resin molding for electrical parts having excellent thermal properties such as heat resistance, flame retardancy, dimensional stability, and mechanical properties such as wear resistance, which are suitable for contact support parts such as electromagnetic switches, housings, etc. products and methods of manufacture thereof. Background technique [0002] Generally speaking, compared with widely used plastics, resin molded products used in electrical parts and the like require not only high strength, dimensional stability, and wear-resistant mechanical properties, but also thermal properties such as heat resistance and flame retardancy. Conventionally, thermosetting resins such as epoxy resins and phenolic resins have been used for such resin molded products for electrical parts. [0003] However, in recent years, resin molded products for electrical parts have been required to be environmentally friendly and recyclable...

AI Technical Summary

Problems solved by technology

For example, in the thermoplastic resin molded articles disclosed in JP-A-57-119911, JP-A-59-12935, and JP-A-61-7336, it is easy to cure by crosslinking. Cause shrinkage or resin decomposition, etc., and then easily lead to deformation; and when kneading into the resin or molding, there is also the risk of gasification and foaming of the crosslinking aid, or the formation of gel due to composition changes; Contamination, deterioration of moldability, problems of thin and precise molded products cannot be obtained; in addition, after adding flame retardants, etc., bleed out occurs, and problems of uniform resin composition cannot be obtained, etc.

[0014] However, when used as molding parts such as the above-mentioned electromagnetic switches, connectors, or circuit breakers, there may be unreacted monomers or decomposed gases of the crosslinking agent due to radiation crosslinking, and oligomers may bleed out to cause electrodes, etc. Metal pollution, adhesion during driving can easily lead to misoperation, and reduce mechanical properties such as wear resistance and cause dimensional changes, etc.

[0015] In the resin compositions disclosed in Japanese Patent Application Laid-Open No. 2001-40206 and Japanese Patent Laid-Open No. 2002-265631 using a thermal catalyst and a silane coupling agent to realize crosslinking and curing, during injection molding, even if heating is used in the mold, the Part of the cross-linking reaction will be carried out, which makes it difficult to control the cross-linking, and the remaining part of the barrel cannot be recovered during molding.

[0016] And when the use of compounding melamine derivatives, cyanuric acid, cyanuric acid, etc. to impart flame retardancy to products disclosed in Japanese Patent Application Publication No. 47-41745 and Japanese Patent Application Publication No. 51-39750, also There are problems such as insufficient heat resistance, dimensional change, and mechanical properties of the resulting molded product

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