Lubricating oil viscosity index improver and lubricating oil composition containing the same

Abstract

Proposed is a lubricating oil viscosity index improver containing a liquid alpha-olefin copolymer in which ethylene and an alpha-olefin monomer having 3 or more carbon atoms are copolymerized, wherein the liquid alpha-olefin copolymer is characterized by having a weight average molecular weight (Mw) in the range of 10,000 to 120,000 g/mol, a permanent shear stability index (PSSI) of greater than 1 and less than 25, and a thickening power of greater than 2.5 cSt and less than 3.6 cSt at a temperature of 100° C. In addition, proposed is a lubricating oil composition containing the lubricating oil viscosity index improver.

Dependencies are inferred from the claim text.