Grease composition

Abstract

Grease composition for use in resin lubrication incorporating into a grease base material which includes a base oil and a fatty acid metal salt thickener at least one saturated or unsaturated fatty acid having from 8 to 22 carbon atoms and / or fatty acid metal salt, being a metal salt of a linear saturated fatty acid having from 8 to 14 carbon atoms or a metal salt of an unsaturated fatty acid having from 16 to 22 carbon atoms and from 1 to 4 unsaturated groups, the metal having a valence of from 1 to 4 excluding fatty acid metal salts used for the thickener. The grease composition of the present invention gives satisfactory lubrication properties between resin and resin or resin and other material such as a metal.

Description

TECHNICAL FIELD OF THE INVENTION[0001]This invention relates to a grease composition for use in resin lubrication which is used at lubrication points where rolling or sliding occur when resin materials are employed.BACKGROUND OF THE INVENTION[0002]In recent years, the use of resin materials for components in various industrial machines, not least in the automotive industry, has become prominent from many points of view, such as lighter weight, lower cost, lower friction, or recycling. But as the structural elements of the components have diversified, many new problems have emerged, and all sorts of technologies are being improved.[0003]For example, in the movable parts of electric door mirrors or the sliding parts of telescopic shafts in car steering, the various sliding parts of R&P steering rack guides, the power transmission gears of electric power steering devices, the internal sliding parts of various actuators and air cylinders, linear guides and ball screw retainers in machin...

AI Technical Summary

Benefits of technology

[0015]According to this invention friction is attenuated so that it is possible to obtain satisfactory lubrication performance at lubrication points such as rolling and sliding points between parts comprising resinous materials one against another, and it is possible to use it over a wide range as a grease composition for use in resin lubrication.

Problems solved by technology

But as the structural elements of the components have diversified, many new problems have emerged, and all sorts of technologies are being improved.

However, despite the fact that the history of the technology of lubrication of resins against resins, or resins against different materials such as metals, is brief, as mentioned above their applications have broadened in recent years, but the present situation is that in the course of this diversification no technology has been presented that is able thoroughly to satisfy the various requirements imposed on lubricating greases.

For example, in the case where technology using phosphorus or sulphur additives effective against friction or wear in the aforementioned metal-to-metal cases is applied to lubrication points of resins and metallic materials, virtually no friction reduction effect such as can be obtained for metal-to-metal is obtained.

In fact there are by no means a few instances where the friction and anti-wear performance deteriorates and the life of the machine component is shortened.

This is thought to be because the chemical activity of the surfaces is much weaker in the case of resins than for metals, and there is virtually no reaction at the rubbing surfaces with organic additives such as those based on phosphorus or sulphur, and given that adsorption is also weak, the effect in regard to friction and wear is paltry, and accordingly the friction reducing effect is weak.

Also, in cases where they are used at boundaries where temperature rises are deliberately effected, the active sulphur and phosphorus in these additives permeate into the resin components and cause cracks and brittleness.

There are also cases where the contrary actions of friction and wear are promoted.