| abstract |
A base oil and (A) a general formula (I) R 1 OOC-A 1 -S- S-A 2 -COOR 2 ··· (I) A disulfide compound represented by general formula (II) R 7 OOC-CR 9 R 10 -CR 11 (COOR 8) -S-S-CR 16 (COOR 13) -CR 14 R 15 -COOR 12 ················・ (II) Containing at least one selected from disulfide compounds represented by the formula (B) and further containing (B) 10 to 2000 ppm by mass of at least one selected from alkali metal or alkaline earth metal detergents as a metal amount. A lubricating oil composition for internal combustion engines. Such a composition has low ash content, low phosphorus content and low sulfur content, yet maintains wear resistance, excellent heat resistance, and long life that can extend the interval between lubricating oils. The lubricating oil composition. |