Resin composition for sliding member, and sliding member

Abstract

A resin composition for sliding members which comprises 1 to 10 wt. % hydrocarbon wax, 0.1 to 3 wt. % at least one member selected from the group consisting of phosphates, sulfates, and carbonates, 1 to 20 wt. % phenoxy resin, 0.1 to 5 wt. % compatibilizing agent, and a polybutylene terephthalate resin as the remainder; and a sliding member obtained by molding the resin composition. The resin composition for sliding members and the sliding member obtained by molding the resin composition have excellent frictional and wearing properties even when a soft metal, e.g., an aluminum alloy, is used as a mating material.

Description

TECHNICAL FIELD [0001] The present invention relates to a resin composition for sliding member and a sliding member using the resin composition. More particularly, the present invention relates to a resin composition for sliding member which is excellent in friction and wear characteristics, in particular, when used together with a slide mating member composed of a soft metal such as an aluminum alloy, and a sliding member using the resin composition. BACKGROUND ART [0002] Thermoplastic polyester resins such as polybutylene terephthalate resins and polyethylene terephthalate resins have been extensively used as materials for mechanical elements such as bearings and gears because of good mechanical strength and wear resistance thereof. However, these thermoplastic polyester resins fail to exhibit sufficient friction and wear characteristics when used singly. Therefore, solid lubricants such as graphite, molybdenum disulfide and tetrafluoroethylene resins, lubricating oil agents such ...

AI Technical Summary

Benefits of technology

[0011] In accordance with the present invention, there are provided a resin composition for sliding member which is capable of exhibiting excellent friction and wear characteristics even when used together with a mating member composed of a soft metal such as aluminum alloys, as well as a sliding member using the resin composition.PREFERRED EMBODIMENT FOR CARRYING OUT THE INVENTION

[0012] The present invention is described in detail below. First, the resin composition for sliding member according to the present invention is explained. The resin composition for sliding member according to the present invention is produced by blending a hydrocarbon-based wax, at least one compound selected from the group consisting of a phosphate, a sulfate and a carbonate, a phenoxy resin, a compatibilizing agent, and a polybutylene terephthalate resin as a main component (hereinafter referred to merely as “PBT”) with each other, and preferably further contains an aromatic polyamide resin or an aromatic polyester resin as a wear-resisting filler.

[0013] Examples of the hydrocarbon-based wax used in the present invention may include paraffin waxes, polyethylene waxes and microcrystalline waxes. These hydrocarbon-based waxes have not only the effect of reducing a coefficient of friction of the obtained sliding member, but also the effect of considerably reducing the damage to a slide mating member.

[0014] The amount of the hydrocarbon-based wax blended is usually 1 to 10% by weight, preferably 3 to 7% by weight, more preferably 5 to 7% by weight. When the amount of the hydrocarbon-based wax blended is less than 1% by weight, the hydrocarbon-based wax may fail to impart a sufficient low-frictional property to the resin composition, resulting in poor low-frictional property of the obtained resin composition. When the amount of the hydrocarbon-based wax blended is more than 10% by weight, the resultant resin composition tends to be deteriorated in moldability, and a sliding member produced from such resin composition tends to be deteriorated in strength.

[0015] The phosphate, sulfate and carbonate used in the present invention are substances having no lubricating property by themselves. However, when blended to a mixture of PBT and the hydrocarbon-based wax, these compounds can exhibit such an effect of promoting formation of a film composed of the mixture on the surface of a mating member upon sliding with the mating member, and enhancing a retention property of the film on the surface of the mating member as well as a durability thereof.

[0016] The amount of at least one compound selected from the phosphate, sulfate and carbonate is usually 0.1 to 3% by weight, preferably 0.5 to 2% by weight. When the amount of the compound blended is less than 0.1% by weight, it may be difficult to exhibit the effect of promoting formation of a film composed of a mixture of PBT and the hydrocarbon-based wax on the surface of a mating member, and enhancing a retention property of the film on the surface of the mating member as well as a durability thereof. When the amount of the compound blended is more than 3% by weight, the resultant composition tends to be deteriorated in capability of forming a film composed of the mixture on the surface of the mating member, so that it may be difficult to form a good film composed of the mixture on the surface of the mating member, resulting in poor friction and wear characteristics of the obtained sliding member.

Problems solved by technology

However, these thermoplastic polyester resins fail to exhibit sufficient friction and wear characteristics when used singly.

However, the sliding members produced from the resin compositions described in the above patent documents have such a problem that when used together with a mating member composed of aluminum alloys, a coefficient of friction thereof is high, and a wear amount thereof is large.

Also, the surface of the mating member composed of aluminum alloys tends to be severely damaged depending upon use conditions thereof.

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