Lubricating Oil Composition

Abstract

A lubricating oil composition comprising: (A) an oil of lubricating viscosity in a major amount; (B) an oil-soluble polymeric additive component (B) as an additive in a minor amount. The lubricating oil composition exhibits enhanced oxidative stability when used to lubricate a spark-ignited or compression-ignited internal combustion engine which is fuelled with a biofuel.

1 . A lubricating oil composition comprising:
 (A) an oil of lubricating viscosity in a major amount; and   (B) an oil-soluble or oil-dispersible additive component (B) as an additive in a minor amount, obtained or obtainable by the reaction of at least one of an acylating agent, an alkylating agent or an arylating agent with a compound of Formula I:   
       
         
           
           
               
               
           
         
       
       wherein:
 each Ar independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, aryloxy, aryloxyalkyl, hydroxy, hydroxyalkyl, halo and combinations thereof; each L is independently a linking moiety comprising a carbon-carbon single bond or a linking group; 
 each Y independently represents —OR 1  or a moiety of the formula H(O(CR 2 R 3 ) n ) y X—, wherein: each R 1  independently represents a C 1  to C 30  alkyl group or an aryl group; each X is independently selected from the group consisting of (CR 4 R 5 ) Z , O and S; each R 2 , R 3 , R 4  and R 5  independently represents H, C 1  to C 6  alkyl or aryl; z is 1 to 10; n is 0 to 10 when X is (CR 4 R 5 ) Z  with the proviso that when n is 0 then y is 1; n is 2 to 10 when X is O or S; and y is 1 to 30; each a is independently 0 to 3, with the proviso that at least one Ar moiety bears at least one group Y of the formula H(O(CR 2 R 3 ) n ) y X—; and m is 1 to 100; and, 
 wherein the lubricating oil composition is contaminated with at least 0.3 mass %, based on the total mass of the lubricating oil composition, of a biofuel or a decomposition product thereof and mixtures thereof. 
 
     
     
         2 . A lubricating oil composition as claimed in  claim 1 , wherein each Ar in a compound of Formula I independently represents a polycyclic carbocyclic aromatic moiety, preferably each Ar represents naphthalene. 
     
     
         3 . A lubricating oil composition as claimed in  claim 1 , wherein each L in a compound of Formula I independently represents a linking group. 
     
     
         4 . A lubricating oil composition as claimed in  claim 1 , wherein each X in a compound of Formula I represents O. 
     
     
         5 . A lubricating oil composition as claimed in  claim 1 , wherein each R 2  and R 3  in a compound of Formula I are identical. 
     
     
         6 . A lubricating oil composition as claimed in  claim 1 , wherein each n in a compound of Formula I independently represents 2 to 5. 
     
     
         7 . A lubricating oil composition as claimed in  claim 1 , wherein each y in a compound of Formula I independently represents 1 to 6. 
     
     
         8 . A lubricating oil composition as claimed in  claim 1 , wherein each a in a compound of Formula I independently represents 1 to 3. 
     
     
         9 . A lubricating oil composition as claimed in  claim 1 , wherein each Y in a compound of Formula I is independently a moiety of formula H(O(CR 2 R 3 ) n ) y X— 
     
     
         10 . A lubricating oil composition as claimed in  claim 9 , wherein each Y in a compound of Formula I is HOCH 2 CH 2 O—. 
     
     
         11 . A lubricating oil composition as claimed in  claim 1 , wherein each R′ in a compound of Formula I independently represents C 1  to C 10  alkyl. 
     
     
         12 . A lubricating oil composition as claimed in  claim 11 , wherein at least one Ar moiety in a compound of Formula I bears at least one group Y of the formula —OR 1 , wherein 40 mol. % to 60 mol. % of Y groups in a compound of Formula I each independently represent H(O(CR 2 R 3 ) n ) y X— and 60 mol. % to 40 mol. % of Y groups in a compound of Formula I each independently represent —OR 1 . 
     
     
         13 . A lubricating oil composition as claimed in  claim 1 , wherein the oil-soluble or oil-dispersible additive component (B) is obtained by the reaction of an acylating agent with a compound of Formula I. 
     
     
         14 . A lubricating oil composition as claimed in  claim 13 , wherein said acylating agent is selected from the group consisting of (i) a hydrocarbyl succinic acylating agent derived from a polyalkene having a M n  of 100 to 5000; and, (ii) a hydrocarbyl isocyanate derived from a polyalkene having a M r , of 100 to 5000. 
     
     
         15 . A lubricating oil composition comprising:
 (A) an oil of lubricating viscosity in a major amount; and   (B) a minor amount of an oil-soluble or oil-dispersible additive component (B) represented by Formula II:   
       
         
           
           
               
               
           
         
       
       wherein:
 each Ar independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, aryloxy, aryloxyalkyl, hydroxy, hydroxyalkyl, halo and combinations thereof; each L is independently a linking moiety comprising a carbon-carbon single bond or a linking group; 
 each Y′ independently represents —OR 1  or a moiety of the formula Z(O(CR 2 R 3 ) n ) y X—; wherein: each R 1  independently represents a C 1  to C 30  alkyl group or an aryl group; each X is independently selected from the group consisting of (CR 4 R 5 ) Z , O and S; each R 2 , R 3 , R 4  and R 5  independently represents H, C 1  to C 6  alkyl or aryl; z is 1 to 10; n is 0 to 10 when X is (CR 4 R 5 ) Z  with the proviso that when n is 0 then y is 1; n is 2 to 10 when X is O or S; and y is 1 to 30; each a is independently 0 to 3, and each Z independently represents H, an acyl group, a polyacyl group, a lactone ester group, an acid ester group, an alkyl group or an aryl group, with the proviso that, at least one Ar moiety bears at least one substituent group Y′ of the formula Z(O(CR 2 R 3 ) n ) y X— in which Z is not H; and, 
 wherein the lubricating oil composition is contaminated with at least 0.3 mass %, based on the total mass of the lubricating oil composition, of a biofuel, a decomposition product of a biofuel or a mixture thereof. 
 
     
     
         16 . A lubricating oil composition as claimed in  claim 15 , wherein each Y′ in a compound of Formula II is independently a moiety of formula Z(O(CR 2 R 3 ) n ) y X—. 
     
     
         17 . A lubricating oil composition as claimed in  claim 16 , wherein each Y′ in a compound of Formula II is ZOCH 2 CH 2 O—. 
     
     
         18 . A lubricating oil composition as claimed in  claim 15 , wherein each R′ in a compound of Formula II independently represents C 1  to C 10  alkyl. 
     
     
         19 . A lubricating oil composition as claimed in  claim 18 , wherein at least one Ar moiety in a compound of Formula II bears at least one group Y′ of the formula —OR 1 . 
     
     
         20 . A lubricating oil composition as claimed in  claim 19 , wherein 40 mol. % to 60 mol. % of Y′ groups in a compound of Formula II each independently represent Z(O(CR 2 R 3 ) n ) y X— and 60 mol. % to 40 mol. % of Y′ groups in a compound of Formula II each independently represent —OR 1 . 
     
     
         21 . A lubricating oil composition as claimed in  claim 15 , wherein each Z independently represents H, an acyl group, a polyacyl group, a lactone ester group or an acid ester group. 
     
     
         22 . A lubricating oil composition as claimed in  claim 1 , wherein the oil-soluble or oil-dispersible additive component B is present in an amount of 0.1 to 5 mass %, based on the total mass of the lubricating oil composition. 
     
     
         23 . A lubricating oil composition as claimed in  claim 15 , wherein the oil-soluble or oil-dispersible additive component B is present in an amount of 0.1 to 5 mass %, based on the total mass of the lubricating oil composition. 
     
     
         24 . A method of lubricating a spark-ignited or compression-ignited internal combustion engine which is fuelled at least in part with a biofuel, comprising operating the engine with a lubricating oil composition as defined in  claim 1 . 
     
     
         25 . A method of lubricating a spark-ignited or compression-ignited internal combustion engine which is fuelled at least in part with a biofuel, comprising operating the engine with a lubricating oil composition as defined in  claim 15 .