Grease composition, viscous agent, and mechanical element

Abstract

A grease composition comprising at least one polymer having a mesogen structure in the principal chain or in the side chain(s) thereof, and at least one viscous agent is disclosed. A viscous agent which is a discotic compound having, in the molecule thereof, a discotic core and three or more side chain groups radially extended from said discotic core is also disclosed. The discotic core and / or said side chain groups has at least one tautomeric group therein, and at least one side chain group of said three or more side chains has, at the end portion thereof, a long chain group in which 20 or more atoms selected from the group consisting of oxygen, carbon, nitrogen, silicon and sulfur atoms are linked in a straight-chain-like manner or in a branched manner.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims benefit of priority under 35 U.S.C. 119 to Japanese Patent Application Nos. 2007-031359 filed Feb. 9, 2007, 2007-031360 filed Feb. 9, 2007, 2007-031361 filed Feb. 9, 2007, 2007-031362 filed Feb. 9, 2007, 2007-262836 filed Oct. 9, 2007 and 2007-262837 Oct. 9, 2007, and the entire contents of the applications are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a grease composition, a viscous agent and a mechanical element.[0004]2. Related Art[0005]Lubricating grease used as a lubricant for mechanical components generally contains viscous agent, base oil, and additives. Most part of characteristics of grease is often determined by types of the viscous agent, or types of the base oil, wherein additives are used in order to impart characteristics not sufficiently covered by them.[0006]With recent progress made in the industrial field with ...

AI Technical Summary

Benefits of technology

[0014]An object of a first invention is to provide a grease composition having low friction performance and low wearing performance.

[0016]An object of a third invention is to provide a novel environmentally-compatible viscous agent, and is to provide a novel viscous agent capable of satisfying both of a desirable level of elastic fluid lubrication under high pressure and large shearing field, and desirable lubricating performance at various interfaces, without degrading its desirable thixotropic performance and lubricating performance.

Problems solved by technology

The grease composition has, therefore, been exhibiting important functions in lubrication and protection of contact portions of sliding components such as roller bearing, slide bearing, sintered bearing, gear, valve, cock, oil seal, electric contacts and so forth, all of which being not readily accesible for replacement of lubricating oils.

However, the viscous agent in the grease composition cannot contribute to lubricating performance, that is to reduce friction, and suffers from an intrinsic problem of gradually degrading its viscosity-enhancing function under severe shearing, which is intrinsically ascribable to its chemical structure.

Another problem is such that the grease composition is not always optimally selected for lubrication of resin surfaces, despite its relatively larger opportunities of use for resin surfaces, but is used only after being appropriately adjusted in the content of extreme pressure agents (most of which are substances of environmental impact) used for lubrication of steel base.

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