ESTER-BASED LUBRICATING OIL COMPOSITION

摘要

PURPOSE: To obtain the subject composition having extremely excellent oxidation stability to cause little increase in acid value, variation of viscosity and generation of sludge and exhibiting prolonged life by using a specific amine-based antioxidant in combination with a specific phenolic antioxidant. CONSTITUTION: This composition is produced by incorporating (A) a base oil composed of an unsaturated fatty acid polyol ester with (B) 0.8-5wt.% of a dehydrative condensation product of an alkylated phenol andα-naphthylamine and (C) 0.1-1wt.% of 2,6-di-t-butyl-p-cresol. Preferably, the component A is e.g. a reaction product of an unsaturated fatty acid such as telacrylic acid and a polyol such as ethylene glycol and the component B is e.g. a compound produced by the dehydrative condensation of an alkylated phenol such as p- methylphenol andα-naphthylamine, etc.