Compounds and lubricant compositions containing the same

Abstract

A lubricating composition including an oil of lubricating viscosity and at least one of an ortho-oxy substituted diphenylamine compound, a para-oxy substituted diphenylamine compound, or a substituted N-arylchroman-6-amine compound. Methods of using such lubricating compositions are also disclosed.

1 . A lubricating composition comprising an oil of lubricating viscosity and at least one of an ortho-oxy substituted diphenylamine compound, a para-oxy substituted diphenylamine compound, or a substituted N-arylchroman-6-amine compound. 
     
     
         2 . The lubricating composition of  claim 1 , wherein the ortho-oxy substituted diphenylamine compound is represented by the general formula I: 
       
         
           
           
               
               
           
         
         wherein:
 each R 1  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, a substituted or unsubstituted aryl group, or a C 2  to C 24  carbonyl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
 each R 2  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, or a substituted or unsubstituted aryl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
 each R 3  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, or a substituted or unsubstituted aryl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; and 
 each R 4  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, a substituted or unsubstituted aryl group, a C 2  to C 24  carbonyl group, a C 2  to C 24  carboxyl group, a C 2  to C 24  carboxylate group, or a group represented by general formula I (such that a symmetrical molecule is created with 2 groups represented by general formula I joined by a methylene group); wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
 wherein, taken together, R 1 , R 2 , R 3 , and R 4  provide a total of at least 8 carbon atoms. 
 
       
     
     
         3 . The lubricating composition of  claim 1 , wherein the para-oxy substituted diphenylamine compound is represented by the following general formula II: 
       
         
           
           
               
               
           
         
         wherein:
 each R 5  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, a substituted or unsubstituted aryl group, or a C 2  to C 24  carbonyl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
 each R 6  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, a substituted or unsubstituted aryl group, or a group represented by general formula II (such that a symmetrical molecule is created with 2 groups represented by general formula II joined by a methylene group); wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
 each R 7  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, or a substituted or unsubstituted aryl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; and 
 each R 8  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, a substituted or unsubstituted aryl group, a C 2  to C 24  carbonyl group, a C 2  to C 24  carboxyl group, or a C 2  to C 24  carboxylate group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
 wherein, taken together, R 5 , R 6 , R 7 , or R 8  provide a total of at least 8 carbon atoms. 
 
       
     
     
         4 . The lubricating composition of  claim 1 , wherein the substituted N-arylchroman-6-amine compound is represented by the following general formula III: 
       
         
           
           
               
               
           
         
         wherein:
 each R 9  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, a substituted or unsubstituted aryl group, or a group represented by general formula III (such that a symmetrical molecule is created with 2 groups represented by general formula III joined by a methylene group); wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
 
         each R 10  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, or a substituted or unsubstituted aryl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
         each R 11  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, or a substituted or unsubstituted aryl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; and 
         each R 12  is, independently, H, a C 2  to C 24  alkyl group, a C 2  to C 24  alkenyl group, or a substituted or unsubstituted aryl group; wherein, for a substituted aryl group, the substitution is a C 1  to C 24  hydrocarbyl substituent; 
         wherein, taken together, R 9 , R 10 , R 11 , and R 12  provide a total of at least 8 carbon atoms. 
       
     
     
         5 . The lubricating composition of  claim 1 , wherein the at least one of an ortho-oxy substituted diphenylamine compound, a para-oxy substituted diphenylamine compound, or a substituted N-arylchroman-6-amine compound is present in the lubricating composition in an amount 0.1 to 5.0 weight percent, based on the total weight of the lubricating composition. 
     
     
         6 . The lubricating composition of  claim 1 , wherein the lubricating composition comprises at least one additional lubricant additive comprising at least one of an ashless polyisobutenyl succinimide dispersant, an overbased or neutral metal-based detergent, an anti-wear agent, a polymeric viscosity modifier, an ashless antioxidant different from the at least one of an ortho-oxy substituted diphenylamine compound, a para-oxy substituted diphenylamine compound, or a substituted N-arylchroman-6-amine compound. 
     
     
         7 . The lubricating composition of  claim 6 , wherein the ashless polyisobutenyl succinimide dispersant is present in the lubricating composition in an amount of from 0.5 to 4.0 weight percent, based on the total weight of the lubricating composition. 
     
     
         8 . The lubricating composition of  claim 6 , wherein the metal-based detergent comprises at least one of a neutral alkaline earth metal detergent or an overbased alkaline earth metal detergent, in an amount of from 0.2 to 15 weight percent, based on the total weight of the lubricating composition. 
     
     
         9 . The lubricating composition of  claim 8 , wherein the at least one of a neutral alkaline earth metal detergent or an overbased alkaline earth metal detergent comprises at least one of an alkylbenzene sulfonate detergent, a sulfur-coupled phenate detergent, or an alkylsalicylate detergent. 
     
     
         10 . The lubricating composition of  claim 6 , wherein at least one anti-wear agent is present in an amount of from 0.05 to 3 weight percent, based on the total weight of the lubricating composition. 
     
     
         11 . The lubricating composition of  claim 10 , wherein the at least one anti-wear agent comprises a phosphorus-containing compound in an amount effective to deliver 200 to 2000 ppm phosphorus to the lubricating composition. 
     
     
         12 . The lubricating composition of  claim 10 , wherein the at least one anti-wear agent comprises a zinc dialkyl dithiophosphate. 
     
     
         13 . The lubricating composition of  claim 6 , wherein the ashless antioxidant different from the at least one of an ortho-oxy substituted diphenylamine compound, a para-oxy substituted diphenylamine compound, or a substituted N-arylchroman-6-amine compound is present in an amount of from 0.01 to 5 weight percent, based on the total weight of the lubricating composition. 
     
     
         14 . The lubricating composition of  claim 1 , wherein the lubricating composition comprises less than 0.1 weight percent of a diarylamine antioxidant. 
     
     
         15 . The lubricating composition of  claim 1 , wherein the lubricating composition is substantially free of a diarylamine antioxidant. 
     
     
         16 . A method of lubricating an internal combustion engine comprising supplying to the internal combustion engine the lubricating composition of  claim 1 . 
     
     
         17 . A method of improving the oxidative resistance of a crankcase lubricant, wherein the method comprises lubricating the crankcase with the lubricating composition of  claim 1 . 
     
     
         18 . A method of reducing viscosity increase of a crankcase lubricant during operation and/or testing, wherein the method comprises lubricating the crankcase with the lubricating composition of  claim 1 . 
     
     
         19 . A method of reducing acid number increase of a crankcase lubricant during operation and/or testing, wherein the method comprises lubricating the crankcase with the lubricating composition of  claim 1 .