Diesel fuel compositions

Abstract

A diesel fuel composition made up of a major amount of a diesel fuel, a minor amount of at least one metallic species and a minor amount of a detergent additive is disclosed. The detergent additive includes a compound of formula: wherein: each Ar independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl alkoxy, alkoxyalkyl, hydroxy, hydroxyalkyl, halo and combinations thereof or additionally, in the case of formula II, acyloxy, acyloxyalkyl, aryloxy, aryloxy alkyl, halo and combinations thereof, each L is independently a linking moiety comprising a carbon-carbon single bond or a linking group; each Y is independently a moiety of the formula H(O(CR 2 ) n ) y X—, wherein X is selected from the group consisting of (CR′ 2 ) 2 , O and S; R and R′ are each independently selected from H, C 1 to C 6 alkyl and aryl; z is 1 to 10; n is 0 to 10 when X is (CR′ 2 ) 7 , and 2 to 10 when X is O or S; and y is 1 to 30; each Y′ is independently a moiety of the formula Z(O(CR 2 ) n ) y X—, wherein X is selected from the group consisting of (CR′ 2 ) 2 , O and S; R and R′ are each independently selected from H, C 1 to C 6 alkyl and aryl; z is 1 to 10; n is 0 to 10 when X is (CR′ 2 ) z , and 2 to 10 when X is O or S; y is 1 to 30; Z is H, an acyl group, an alkyl group or an aryl group; each a is independently 0 to 3, with the proviso that in formula (I), at least one Ar moiety bears at least one group Y; and with the proviso that in formula (II), at least one Ar moiety bears at least one group Y′ in which Z is not H; and m is 1 to 100.

1 . A diesel fuel composition comprising a major amount of a diesel fuel, a minor amount of at least one metallic species and a minor amount of a detergent additive; wherein the detergent additive comprises at least one compound of formula (I) and&or 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 is independently —OR 1″  or a moiety of the formula H(O(CR 1   2 ) n ) y X—, wherein X is selected from the group consisting of (CR 1,   2 ) z , O and S; R 1  and R 1′  are each independently selected from H, C 1  to C 6  alkyl and aryl; R 1″  is selected from C 1  to C 100  alkyl and aryl; z is 1 to 10; n is O to 10 when X is (CR 1′   2 ) z , and 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; and 
       m is 1 to 100; 
     
     
       
         
         
             
             
         
       
       wherein: 
       each Ar′ independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, hydroxy, hydroxyalkyl, acyloxy, acyloxyalkyl acyloxyalkoxy, aryloxy aryloxyalkyl, aryloxyalkoxy, halo and combinations thereof; 
       each L′ is independently a linking moiety comprising a carbon-carbon single bond or a linking group; 
       each Y′ is independently a moiety of the formula ZO- or Z(O(CR 2   2 ) n′ ) y ,X′—, wherein X′ is selected from the group consisting of (CR 2′   2 ) 2 , O and S; R 2  and R 2′  are each independently selected from H, C 1  to C 6  alkyl and aryl; z′ is 1 to 10; n′ is 0 to 10 when X′ is (CR 2′   2 ) z′ , and 2 to 10 when X∝is O or S; y′ is 1 to 30; Z is H, an acyl group, a polyacyl group, a lactone ester group, an acid ester group, an alkyl group or an aryl group; 
       each a′ is independently 0 to 3, with the proviso that at least one Ar′ moiety bears at least one group Y′ in which Z is not H; and 
       m′ is 1 to 100. 
     
   
   
       2 . A diesel fuel composition according to  claim 1  wherein said compound is a compound of formula (II) wherein Y′ is Z(O(CR 2   2 ) 2 ) y′ O—, Z is an acyl group and y′ is 1 to 6. 
   
   
       3 . A diesel fuel composition according to  claim 1  wherein Ar′is naphthalene, Y′is ZOCHCH 2 O—, Z is an acyl group and L′ is CH 2 . 
   
   
       4 . A diesel fuel composition according to  claim 1  wherein Ar′ is derived from 2-(2-naphthyloxy)-ethanol and m′ is 2 to 25. 
   
   
       5 . A diesel fuel composition according to  claim 1  wherein said Z is derived from either (i) a polyalkyl or polyalkenyl succinic acylating agent having  M   n  of from about 100 to about 5000 or (ii) from hydrocarbyl isocyanate. 
   
   
       6 . A diesel fuel composition according to  claim 1  wherein the detergent additive is present in an amount such that the fuel contains between 50 and 300 ppm by weight of a compound of formula (I) and/or a compound of formula (II), based on the weight of the fuel. 
   
   
       7 . A diesel fuel composition according to  claim 1  wherein said compound is a compound of Formula (III): 
     
       
         
         
             
             
         
       
     
     wherein one or more Y′ are groups Z(O(CR 2   2 ) n′ ) y′ X′— in which Z is derived from lactone ester of formula IV, acid ester of formula V, or a combination thereof; 
     
       
         
         
             
             
         
       
     
     wherein R 3 , R 4 , R 5 , R 6  R 7 , R 8  and R 9  are independently selected from H, alkyl and polyalkyl and polyalkenyl containing up to 200 C; and Z is bisacyl of formula VI; 
     
       
         
         
             
             
         
       
       wherein R 10  and R 11  are independently selected from H, alkyl and polyalkyl and polyalkenyl containing up to 300 C; m′ is 0 to 100; and p and s are each independently about 0 to about 25 with the proviso that p≦m′; s≦m′; and p+s≦1. 
     
   
   
       8 . A diesel fuel composition according to  claim 7 , wherein said compound is a compound of Formula (III) wherein from 2% to 98% of the Y′ units are Z(O(CR 2   2 ) 2 ) y′ O—, wherein Z is an acyl group and y′ is 1 to 6, and from 98% to 2% of Y′ units are —OR 2″ . 
   
   
       9 . A diesel fuel composition according to  claim 8 , wherein said compound is a compound of Formula (III) wherein Ar′ is naphthalene; from 2% to 98% of Y′ units are ZOCH 2 CH 2 O—, from 98% to 2% of Y′ units are —OCH 3 ; and L′ is CH 2 . 
   
   
       10 . A diesel fuel composition according to  claim 9 , wherein said compound is a compound of Formula (III) wherein Ar′ is naphthalene; from 40% to 60% of Y′ units are ZOCH 2 CH 2 O—, and from 60% to 40% of Y′ units are —OCH 3 ; m′ is from 2 to 25; p is from 1 to 10; andsis from 1 to 10. 
   
   
       11 . A method of substantially removing, or reducing the occurrence of, injector deposits in a diesel engine operated using a diesel fuel containing a minor amount of a metal-containing species, the method comprising adding to the diesel fuel a detergent additive comprising a compound of formula (I) and/or a compound of formula (II) as defined in  claim 1 , wherein the diesel engine is equipped with fuel injectors having a plurality of spray-holes, each spray-hole having an inlet and an outlet and wherein the fuel injectors have one or more of the following characteristics:
 (i) spray-holes which are tapered such that the inlet diameter of the spray-holes is greater than the outlet diameter;   (ii) spray-holes having an outlet diameter of 0.10 mm or less;   (iii) spray-holes where an inner edge of the inlet is rounded;   (iv) 6 or more spray-holes;   (v) an operating tip temperature in excess of 250° C.   
   
   
       12 . The method of  claim 11  wherein the fuel injectors have two or more of characteristics (i) to (v).