Lubricant composition and mechanical element

Abstract

A novel lubricant composition is disclosed. The lubricant composition comprises at least one organic compound, and, when disposed between two surfaces moving at peripheral speeds differing from each other, is capable of exhibiting a discotic columnar phase or a discotic lamellar phase in which a plurality of molecules of said organic compound is assembled.

Description

[0001] This application claims benefit of priority under 35 U.S.C. 119 to Japanese Patent Application No. 2005-150479 filed May 24, 2005. BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] The present invention relates to a lubricant composition applicable to mechanical elements used under frictional sliding, and in particular to a lubricant composition applicable to mechanical elements, excellent in a low traction performance under a condition of elastic-fluid lubrication condition. [0004] 2. Related Art [0005] Materials used as being disposed between solid surfaces under relative motion in machines and apparatuses, aimed at reducing friction, and preventing or moderating the surface damage are referred to as lubricant, and among them, oils are most widely used as lubricant. A lubricating oil generally contains a hydrocarbon, as a base oil, obtained in a form of fraction of petroleum, and various additives added thereto depending on purposes. Although being considerably v...

AI Technical Summary

Benefits of technology

[0008] It is therefore an object of the present invention to provide a lubricant composition having a low viscosity, and affording a low traction coefficient under strict extreme-pressure conditions over a wide temperature range, and to provide a low-traction mechanical element excellent in friction resistance.

[0012] According to the present invention, there is provided a lubricant composition having a low viscosity, and affording a low traction coefficient under strict extreme-pressure conditions over a wide temperature range, and there is also provided a low-traction mechanical element excellent in friction resistance.

[0013] According to the prior art related to lubricating techniques under extreme-pressure ever adopted, the lack of the strength of an oil film formed of low-viscosity, low-traction mineral oil or oil-and-fat-base synthetic lubricant has been compensated by polymer-base, sulfur-containing, or heavy-metal-base interface coating agent. According to the invention, such prior technique can be replaced with a novel technique using a material capable of exhibiting a discotic columnar phase or a discotic lamellar phase under extreme pressure and shear, to thereby allow a low viscosity to exhibit under extreme pressure. The present invention is successful not only in obtaining an extremely low traction performance superior to the conventional low traction coefficient, but also in obtaining a further tough friction resistance by using the material capable of covering the interface based on a highly-ordered alignment. In the current situation strictly demanding reduction in fuel consumption from the viewpoints of energy saving, prevention of global warming and environmental preservation, the present invention can therefore provide a novel technique contributive to solution of these problems ascribable to the Piezo-viscosity effect, which has been a big wall of scientific principle. The present invention is in no need of using any environmentally hazardous sulfur compounds, phosphorus compounds and heavy metals such as zinc, molybdenum and so forth, and is capable of providing a high-performance, environment-friendly lubricant composition by using organic compound(s) only.

Problems solved by technology

All of these liquid crystals are, however, rod-like liquid crystals, whereas discotic liquid crystals based on the opposite concept are generally known to have high viscosity, so that low-viscosity ones operable as lubricant are not so readily available.

“Tokkohei” No. 2-21436 and “Tokuhyohei” No. 2-503326, however, do not disclose friction coefficients under standard evaluation systems.

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