Wear inhibitor and lubricating oil composition

Abstract

The present invention aims to provide an anti-wear agent having a high anti-wear effect and a lubricating oil composition containing the anti-wear agent. The present invention relates to an anti-wear agent containing a copolymer (A) that contains, as essential constituent monomers: a monomer (a) represented by the following formula (1); and a monomer (b) represented by the following formula (2), a weight ratio (b/a) of the monomer (b) to the monomer (a) in the copolymer (A) being 0.0005 to 0.12, the formula (1) being as follows: wherein A1 is a polymerizable group; —X1—, —X2—, and —X3— are each independently a group represented by —O— or —NH—; R1 is a C1-C4 alkylene group; R2 is a C2-C20 alkylene group; R3 is a hydrogen atom, a linear or branched C1-C44 alkyl group, a phenyl group having a linear or branched C1-C44 alkyl group, an acyl group having a linear or branched C1-C44 alkyl group, or a benzoyl group having a linear or branched C1-C44 alkyl group; and p is an integer of 1 to 100, where when p is 2 or more, a plurality of R2's are the same as or different from each other and a plurality of X3's are the same as or different from each other, the formula (2) being as follows: wherein R4 is a hydrogen atom or a methyl group; —X4— is a group represented by —O— or —NH—; R5 is a C1-C4 alkylene group; and —X5— is a group represented by —O— or —NH—.

Dependencies are inferred from the claim text.