Lubricating oil composition for corrosion control

Abstract

A lubricating oil composition is disclosed. The composition includes a major amount of an oil of lubricating viscosity, one or more alkylhydroxy benzoate compound derived from isomerized normal alpha olefins, and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine. The molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition. The diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.

1 . A lubricating oil composition comprising:
 major amount of an oil of lubricating viscosity;   one or more alkylhydroxybenzoate compound derived from isomerized normal alpha olefins; and   oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine;   wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.   
     
     
         2 . The lubricating oil composition of  claim 1 , wherein the alkylhydroxybenozate compound has a TBN of 10 to 300 mg KOH/g on an oil-free basis. 
     
     
         3 . The lubricating oil composition of  claim 1 , wherein the one or more alkylhydroxybenzoate compound has a TBN of 600 mg KOH/g or greater on an oil-free basis. 
     
     
         4 . The lubricating oil composition of  claim 1 , wherein the one or more alkylhydroxybenzonate compound is a mixture of alkylhydroxybenzoate compound having a TBN of 10 to 300 mg KOH/g on an oil-free basis and alkylhydroxybenzoate compound having a TBN of 600 mg KOH/g or greater on an oil-free basis. 
     
     
         5 . The lubricating oil composition of  claim 1 , wherein the molybdenum-containing antioxidant is molybdenum succinimide, molybdenum dithiocarbamate, or trinuclear molybdenum compound. 
     
     
         6 . The lubricating oil composition of  claim 1 , further comprising a friction modifier, viscosity index improver, corrosion inhibitor, or pour point depressant. 
     
     
         7 . The lubricating oil composition of  claim 1 , wherein the isomerized normal alpha olefins contain 10 to 40 carbon atoms. 
     
     
         8 . A method for reducing copper corrosion in an engine, the method comprising:
 lubricating the engine with a lubricating oil composition comprising:
 major amount of an oil of lubricating viscosity; 
 one or more alkylhydroxybenzoate compound derived from isomerized normal alpha olefins; and 
 oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine; 
 wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition. 
   
     
     
         9 . The method of  claim 8 , wherein the alkylhydroxybenozate compound has a TBN of 10 to 300 mg KOH/g on an oil-free basis. 
     
     
         10 . The method of  claim 8 , wherein the one or more alkylhydroxybenzoate compound has a TBN of 600 mg KOH/g or greater on an oil-free basis. 
     
     
         11 . The method of  claim 8 , wherein the one or more alkylhydroxybenzonate compound is a mixture of alkylhydroxybenzoate compound having a TBN of 10 to 300 mg KOH/g on an oil-free basis and alkylhydroxybenzoate compound having a TBN of 600 mg KOH/g or greater on an oil-free basis. 
     
     
         12 . The method of  claim 8 , wherein the molybdenum-containing antioxidant is molybdenum succinimide, molybdenum dithiocarbamate, or trinuclear molybdenum compound. 
     
     
         13 . The method of  claim 1 , wherein the lubricating oil composition further comprises a friction modifier, viscosity index improver, corrosion inhibitor, or pour point depressant. 
     
     
         14 . The method of  claim 8 , wherein the isomerized normal alpha olefins contain 10 to 40 carbon atoms. 
     
     
         15 . A lubricating oil composition comprising:
 major amount of an oil of lubricating viscosity;   one or more alkylhydroxybenzoate compound derived from C 10 -C40 isomerized normal alpha olefins; and   oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine;   wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.   
     
     
         16 . The lubricating oil composition of  claim 15 , wherein the alkylhydroxybenozate compound has a TBN of 10 to 300 mg KOH/g on an oil-free basis. 
     
     
         17 . The lubricating oil composition of  claim 15 , wherein the one or more alkylhydroxybenzoate compound has a TBN of 600 mg KOH/g or greater on an oil-free basis. 
     
     
         18 . The lubricating oil composition of  claim 15 , wherein the one or more alkylhydroxybenzonate compound is a mixture of alkylhydroxybenzoate compound having a TBN of 10 to 300 mg KOH/g on an oil-free basis and alkylhydroxybenzoate compound having a TBN of 600 mg KOH/g or greater on an oil-free basis. 
     
     
         19 . The lubricating oil composition of  claim 15 , wherein the molybdenum-containing antioxidant is molybdenum succinimide, molybdenum dithiocarbamate, or trinuclear molybdenum compound. 
     
     
         20 . The lubricating oil composition of  claim 15 , further comprising a friction modifier, viscosity index improver, corrosion inhibitor, or pour point depressant.