| abstract |
Disclosed is an additive for lubricating oil, which comprises a phosphite ester compound (A) having a specific structure and a phosphite ester compound (B) having a specific structure, wherein a mass ratio of the phosphite ester compound (A) to the phosphite ester compound (B) (phosphite ester compound (A):phosphite ester compound (B)) is 99:1 to 80:20. According to the present invention, it is possible to provide an additive for lubricating oil, capable of imparting wear resistance and demulsibility with respect to a base oil for lubricating oil, and to impart durability even in the presence of water. |