Use of nanomaterials as effective viscosity modifiers in lubricating fluids

Abstract

Nanomaterials have been used as a supplement or replacement of traditional polymer-based viscosity modifiers for lubricants and other related fluids. Compared with traditional polymer-based viscosity modifiers, nanomaterials possess better viscosity-index modification functions, i.e., more even viscosity increase across the whole temperature range. Meanwhile, a cost-effective way of making nanomaterials have been developed based on commercially available graphite materials, and the resulting nanoparticles of graphite are nanodisks (nanoplates). Furthermore, it provides a viscosity modifier which exhibits temporary shear loss, which can contribute to fuel economy, but no permanent shear loss.

Description

[0001] This application claims priority from U.S. Provisional Application Ser. No. 60 / 592,570 filed on Jul. 31, 2004 and Provisional Application Ser. No. 60 / 254,959 filed on Dec. 12, 2000 and U.S. Pat. No. 6,783,746 which issued on Aug. 31, 2004 from application Ser. No. 10 / 021,767 filed on Dec. 12, 2001 and application Ser. No. 10 / 929,636 filed on Aug. 30, 2004 and application Ser. No. 10 / 730,762 filed on Dec. 8, 2003 which claims priority from PCT / US02 / 16888 filed on May 30, 2002 and application Ser. No. 10 / 737,731 filed on Dec. 16, 2003 all of which are incorporated herein in their entirety.TECHNICAL FIELD [0002] The present invention relates to a novel use of nanomaterial as a viscosity modifier for a lubricating oil and a lubricating oil composition. More particularly, the invention relates to a novel viscosity modifier for a lubricating oil capable of producing a lubricating oil composition having excellent viscosity index and lubricating oil compositions containing such a vis...

AI Technical Summary

Benefits of technology

[0047] It is an object of the present invention to provide a uniform and stable dispersion where due to the absence of polymeric materials the dispersion exhibits no permanent, only temporary loss in viscosity due to shear fields and turbulence.

[0048] It is an object of the present invention to provide a uniform and stable dispersion where the carbon nanoma

Problems solved by technology

While there have been various patents filed on lubricants containing graphite, e.g. U.S. Pat. No. 6,169,059, there are none which specifically rely on graphite to improve the viscosity index of the fluid.

Furthermore, there are none which teach specifically the use of nanometer-sized graphite with mean particle size much significantly less than 1000 nm in order to increase viscosity index.

While graphite-containing automotive engine oil was once commercialized

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