Combination of phosphate based additives and sulfonate salts for hydraulic fluids and lubricating compositions

摘要

Disclosed are synergistic antioxidant compositions composed of (1) amine salts of alkyl phosphates and (2) ethylenediamine, ammonium or metal salts of alkylarylsulfonates. The antioxidant compositions are useful for formulating zinc-free antiwear hydraulic fluids and gear lubricating oils in conjunction with thiophosphate type antiwear agents, corrosion and rust inhibitors.