| abstract |
A lubricating oil composition for an internal combustion engine, which includes a base oil, (A) at least one member selected from the group consisting of disulfide compounds represented by the general formula (I): n n R 1 OOC-A 1 -S-S-A 2 -COOR 2 (I) n nand disulfide compounds represented by the general formula (II): n n R 7 OOC-CR 9 R 10 -CR 11 (COOR 8 )-S-S-CR 16 (OOR 13 )-CR 14 R 15 COOR 12 (II), n nand (B) at least one member selected from the group consisting of alkali metal-based detergents and alkaline earth metal-based detergents, the component (B) being present in an amount of 10 to 2,000 ppm by mass in terms of metal content. n The lubricating oil composition has a low ash content, a low phosphorous content and a low sulfur content. But, Nonetheless, it can maintain wear resistance, has excellent heat resistance, can extend the lubricating oil change interval and has a long service life. |