Abstract: 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.

Abstract: This invention relates to synergistic antiwear compositions comprising an organomolybdenum complex and an organic sulfuir compound selected from 2,5-dimercapto-1, 3,4-thiadiazole derivatives, bisdithiocarbamate esters, metal dithiocarbamates, metal phosphorodithioates and phosphorodithioate esters. The organomolybdenum complex is a reaction product prepared by reacting 1 mole fatty oil, 1.0 to 2.5 moles diethanolamine and a molybdenum source.Lubricating compositions containing the synergistic compositions possess good antiwear properties and improved oxidation stability.

Abstract: Disclosed are novel compounds prepared by reacting two moles of 2,5-dimercapto-1,3,4-thiadiazole and one mole of a hydrocarbon compound selected from terpenes, aryl compounds and aliphatic compounds which may be substituted by oxygen or oxygen containing groups. The hydrocarbon compound forms a bivalent radical linking together the two 2,5-dimercapto-1,3,4-thiadiazoles. The compounds are effective extreme pressure agents when incorporated into lubricating compositions.