Patent ID: 7696137

Claim:
A lubricating oil composition comprising a lubricating base oil, (A) at least one type of compound selected from the group consisting of zinc salts of phosphorus compounds represented by formula (1) below, and (B) at least one type of compound selected from the group consisting of metal salts of phosphorus compounds represented by formulas (2) and (3) below: wherein R 1 is a hydrocarbon group containing no oxygen or nitrogen, and R 2 and R 3 are each independently hydrogen or a hydrocarbon group having 8 to 30 carbon atoms, which may contain nitrogen and/or oxygen; wherein R 4 and R 5 are each independently a hydrocarbon group having 3 to 30 carbon atoms, which may contain nitrogen and/or oxygen, Y 1 is a metal element, and n is an integer corresponding to the valence of Y 1 ; wherein R 6 is a hydrocarbon group having 3 to 30 carbon atoms, which may contain nitrogen and/or oxygen, and Y 2 is a metal element; and wherein Y 1 in formula (2) and Y 2 in formula (3) are each independently a metal selected from the group consisting of alkaline earth metals and zinc.