Lubricating composition including n-alkylated dianiline

Abstract

A lubricating composition includes an oil of lubricating viscosity, an N-alkylated dianiline compound, and at least one of a) an ashless antioxidant, and b) an overbased calcium detergent. The ashless antioxidant may be selected from a diarylamine antioxidant, a phenolic antioxidant, and combinations thereof. The lubricating composition may contain less than 0.15 weight percent of phosphorus.

1 . A lubricating composition comprising:
 a) an oil of lubricating viscosity;   b) an N-alkylated dianiline compound; and   c) an ashless antioxidant selected from a diarylamine antioxidant, a phenolic antioxidant, and combinations thereof, and   d) an overbased calcium detergent;   wherein the lubricating composition comprises less than 0.15 weight percent of phosphorus; and   wherein the N-alkylated dianiline is an N,N′-alkylated dianiline compound represented by the formula:   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently selected from alkyl groups of 1 to 24 carbon atoms; 
         R 3  and R 4  are independently selected from hydrocarbyl groups of 1 to 6 carbon atoms; 
         each n is from 0 to 3, and 
         X represents a C 1 -C 3  alkylene group. 
       
     
     
         2 . (canceled) 
     
     
         3 . The lubricating composition of  claim 1 , wherein the lubricating composition has a TBN of at least 4 mg KOH/g, as measured in accordance with ASTM D-2896. 
     
     
         4 . (canceled) 
     
     
         5 . The lubricating composition of  claim 1 , wherein at least one of R 1  and R 2  includes a cyclohexyl group. 
     
     
         6 . (canceled) 
     
     
         7 . The lubricating composition of  claim 1 , wherein the N-alkylated dianiline compound is at least 0.10 weight percent of the lubricating composition. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . The lubricating composition of  claim 1 , wherein X is a methylene group. 
     
     
         11 . The lubricating composition of  claim 1 , wherein the N-alkylated dianiline compound is represented by the formula: 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently selected from alkyl groups of 1 to 24 carbon atoms. 
       
     
     
         12 . The lubricating composition of  claim 11 , wherein the N-alkylated dianiline compound is represented by the formula: 
       
         
           
           
               
               
           
         
       
     
     
         13 . The lubricating composition of  claim 1 , wherein the N-alkylated dianiline compound is selected from the group consisting of: 
       
         
           
           
               
               
           
         
         and mixtures thereof. 
       
     
     
         14 . The lubricating composition of  claim 13 , wherein the N-alkylated dianiline compound is selected from 4,4′-2-ethylhexylmethylenedianiline, 4,4′-cyclohexylmethylenedianiline, and mixtures thereof. 
     
     
         15 . The lubricating composition of  claim 1 , wherein the oil of lubricating viscosity is at least 40 weight percent of the lubricating composition. 
     
     
         16 . The lubricating composition of  claim 1 , wherein the ashless antioxidant is at least 0.1 weight % of the lubricating composition. 
     
     
         17 . The lubricating composition of  claim 1 , wherein a ratio of the ashless antioxidant to the N-alkyl dianiline compound is from 20:1 to 1:20. 
     
     
         18 . The lubricating composition of  claim 1 , wherein the ashless antioxidant comprises at least one of:
 a phenolic ester and a diarylamine; and   a sulfurized olefin.   
     
     
         19 . (canceled) 
     
     
         20 . The lubricating composition of  claim 1 , wherein the overbased calcium detergent is selected from sulfonates, non-sulfur containing phenates, sulfur containing phenates, salixarates, salicylates, mixtures thereof, and borated equivalents thereof. 
     
     
         21 . The lubricating composition of  claim 1 , wherein the overbased calcium detergent is present in an amount to deliver at least 2 mg KOH/g of total base number (TBN), as measured in accordance with ASTM D-2896, to the composition. 
     
     
         22 . The lubricating composition of  claim 1 , wherein the overbased calcium detergent is least 0.01 wt. % of the lubricating composition. 
     
     
         23 . The lubricating composition of  claim 1 , wherein a ratio of calcium to magnesium in the lubricating composition, by weight, is at least 9:10. 
     
     
         24 . The lubricating composition of  claim 1 , further comprising a polyolefin succinimide dispersant, wherein a polyolefin group of the polyolefin succinimide dispersant has a number average molecular weight of at least 300. 
     
     
         25 . The lubricating composition of  claim 1 , further comprising a zinc dialkyldithiophosphate. 
     
     
         26 . The lubricating composition of  claim 1 , wherein the lubricating composition comprises at least 0.02 weight percent of phosphorus. 
     
     
         27 . (canceled) 
     
     
         28 . A method for reducing deposit formation in an internal combustion engine comprising lubricating the internal combustion engine with a lubricating composition comprising:
 a) an oil of lubricating viscosity;   b) an N-alkylated dianiline compound;   c) an ashless antioxidant selected from a diarylamine antioxidant, a phenolic antioxidant, and combinations thereof, and   d) an overbased calcium detergent;   wherein the lubricating composition comprises less than 0.15 weight percent of phosphorus; and   wherein the N-alkylated dianiline is an N,N′-alkylated dianiline compound represented by the formula:   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently selected from alkyl groups of 1 to 24 carbon atoms; 
         R 3  and R 4  are independently selected from hydrocarbyl groups of 1 to 6 carbon atoms; 
         each n is from 0 to 3, and 
         X represents a hydrocarbylene group. 
       
     
     
         29 . (canceled) 
     
     
         30 . A method for forming a lubricating composition comprising:
 forming an N,N′-alkylated dianiline compound represented by the formula:   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently selected from alkyl groups of 1 to 24 carbon atoms; 
         R 3  and R 4  are independently selected from hydrocarbyl groups of 1 to 6 carbon atoms; 
         each n is from 0 to 3, and 
         X represents a hydrocarbylene group; and 
         combining the N-alkylated dianiline compound with an oil of lubricating viscosity and at least one of:
 an ashless antioxidant selected from a diarylamine antioxidant, a phenolic antioxidant, and combinations thereof, and 
 an overbased calcium detergent; 
 
         whereby the lubricating composition comprises less than 0.15 weight percent of phosphorus. 
       
     
     
         31 . The lubricating composition of  claim 1 , wherein R 1  and R 2  are independently selected from alkyl groups of at least 4 carbon atoms.