HEAT-RESISTANT LUBRICATING OIL COMPOSITION

摘要

A heat-resistant lubricating oil composition prepared by mixing a lube base oil comprising an organic acid ester or a mixture thereof with polyphenyl ether or organopolysiloxane with 0.05 to 10 wt.% of a polyphenyl thio ether of general formula (I) as an antioxidant, wherein R<1>, R<2> and R<3> are each hydrogen or C1-C24 hydrocarbyl; x, y and z are each an integer of 1 to 4; and m is an integer of 0 to 3; another heat-resistant lubricating oil composition containing, as the base oil, a mixture comprising 10 to 90 wt.% of the above lube base oil and 90 to 10 wt.% of the above polyphenyl thio ether; and a process for preparing the above polyphenyl thio ether. The above compositions exhibit high-level resistances to heat and oxidation under high-temperature conditions and therefore are fit for use under severe conditions, e.g., in jet engine, gas turbine or the like.