POLYALKYLENE SUCCINIMIDE COMPOSITION USEFUL IN INTERNAL COMBUSTION ENGINES

摘要

A lubricating oil composition for internal combustion engines is preferably composed of a major portion of a base oil; 0.5 % to 15 % of a cyclic carbonatetreated polyalkylene succinimide additive; 0.5 % to 15 % of a borated polyalkylene succinimide additive; 0.5 % to 20 % of a metal-containing detergent; and 0.1 % to 3 % of a zinc dialkyldithiophosphate, other additives such as a molybdenum compound, an oxidation inhibitor and a viscosity index improver can be added. The molecular weight of the polyalkylenes from which the carbonated polyalkylene succinimide is derived is preferably at least 300 greater than the molecular weight of the polyalkylenes from which the borated polyalkylene succinimide is derived.