PURPOSE: To obtain a lubricating oil composition with largely improved water separating ability and storage stability by compounding mineral oil and/or synthetic oil as the base oil with a zinc thiophosphate wear-proofing agent, a metal cleaner, an ashless dispersant and a nonionic demulsifier.
CONSTITUTION: The title lubricating oil composition comprises mineral oil and/or synthetic oil as the base oil, a zinc thiophosphate wear-proofing agent, one or more metal cleaners selected from among overbased sulfonates, overbased phenater and overbased phosphenater having an average molecular weight of 400 or more, an ashless dispersant, and a nonionic demulsifier having an average molecular weight of 7,000 or more. The overbased metal cleaners include, for example, Na, Ca, Mg and Ba sulfonates, Ca, Mg and Ba phenater, and Ca, Mg and Ba phosphenater. The nonionic demulsifier includes polyoxyalkylene glycol monoether, polyalkylene adduct of alkylenediamine, etc.
KAMON REIJI
NAKAMURA YOSHINOBU
