Patent ID: 9347018
Filing Date: 2016-05-24
CPC Classification: C10M,C10N

Claim Text:
1. A lubricating oil composition comprising: (A) a lubricant base oil having a kinematic viscosity at 100° C. of from 1.5 to 20 mm (B) a polymethacrylate-containing viscosity index improver which comprises (b-1) a polymethacrylate-containing viscosity index improver having a weight average molecular weight of from 10,000 to 50,000 and (b-2) a polymethacrylate-containing viscosity index improver having a weight average molecular weight of from 100,000 to 270,000, in which a mass ratio (b-1)/(b-2) is from 4 to 0.25; and (C) a sulfur-containing compound having an acid value of not more than 1.0 mg-KOH/g and having formula (1): wherein R is a hydrocarbon group comprising from 8 to 30 carbon atoms, and wherein the composition comprises the polymethacrylate-containing viscosity index improver (B) in an amount of 3 to 15% by mass, based on a total amount of the composition, and the composition comprises the sulfur-containing compound in an amount of 0.1 to 3% by mass, based on the total amount of the composition.