abstract |
A lubricating oil additive comprising an alkaline earth metal salt of a sulfurized monoalkylcatechol as a main component represented by the following general formula (I): <IMAGE> (I) wherein Me represents an alkaline earth metal, R1 and R2 represent each an alkyl group having 14 to 30 carbon atoms, m is a number of from 1 to 2, which provides a lubricating oil additive excellent in anti-oxidant, friction-reducing and anti-abrasive properties at high temperature. |