Patent ID: 7732385

Claim:
A lubricating oil additive comprising at least one lubricating oil additive selected from the group consisting of (1) to (5) below: (1) a lubricating oil additive obtained by dissolving Component (A) in Component (B) comprising an amine-based antioxidant; (2) a lubricating oil additive obtained by reacting Component (A) with Component (B) comprising a succinimide and/or derivative thereof; (3) a lubricating oil additive obtained by reacting Component (A) with Component (B) comprising an aliphatic amine having 8 to 30 carbon atoms; (4) a lubricating oil additive obtained by reacting Component (A) with Component (B) comprising a mixture of an amine-based antioxidant and a succinimide and/or derivative thereof; and (5) a lubricating oil additive obtained by reacting Component (A) with Component (B) comprising a mixture of an amine-based antioxidant and an aliphatic amine; wherein Component (A) comprises at least one compound selected from the group consisting of zinc salts of phosphorus compounds represented by formulas (2): wherein X 4 , X 5 , X 6 , and X 7 are each oxygen and R 14 , R 15 , and R 16 are each independently hydrogen or a hydrocarbon group having 1 to 30 carbon atoms provided that at least one of them is hydrogen.