Patent ID: 9593291
Date: 2017-03-14
CPC Classifications: C10M,C10N,F16C

Claim:
1. A lubricating oil composition, comprising a lubricant base oil and: (A) an organic zinc dithiophosphate in an amount of from 0.005% by mass to 0.10% by mass in terms of phosphorus concentration; (B) a diethanolamide comprising an aliphatic hydrocarbon group having from 16 to 22 carbon atoms in an amount of from 1% by mass to 3% by mass; (C) a calcium salicylate-based detergent, a calcium sulfonate-based detergent, or both, in an amount of from 0.1% by mass to 0.25% by mass in terms of alkaline earth metal concentration; and (D) an ashless dispersant comprising a succinic acid imide, a boron-containing succinic acid imide, or a mixture thereof, based on a total mass of the lubricating oil composition, wherein: the organic zinc dithiophosphate (A) comprises a primary zinc dialkyldithiophosphate in an amount of from 0.005% by mass to 0.05% by mass in terms of phosphorus concentration therein, based on the total mass of the lubricating oil composition; and the lubricating oil composition exhibits a friction coefficient of less than or equal to 0.062 when subjected to a frictional property test in which a diamond-like carbon (DLC) coated disc containing 20 atom % of hydrogen is subject to a load of 100 N at a temperature of 100° C. in a reciprocating friction tester operated at an amplitude of 8 mm with a frequency of 10 Hz.