Diesel detergents

Abstract

A composition for use in preventing deposits in an engine and/or fouling of injectors is prepared by reacting (a) an alkenyl-substituted succinic acid having a molecular weight of about 250 to about 3000 and (b) a polyaziridine having an average molecular weight of about 250 to about 5000.

1 . A composition comprising a reaction product of (a) an alkeny-1-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (b) a polyaziridine having an average molecular weight of about 250 to about 5000. 
     
     
         2 . The composition of  claim 1 , wherein the alkenyl-substituted succinic anhydride has an average molecular weight of about 600 to about 2000. 
     
     
         3 . The composition of  claim 1 , wherein the alkenyl-substituent group contains at least 30 carbon atoms. 
     
     
         4 . The composition of  claim 1 , wherein the alkenyl-substituent group of the alkenyl-substituted succinic anhydride has an average molecular weight of about 200 to about 2950. 
     
     
         5 . The composition of  claim 1 , wherein the alkenyl-substituted succinic anhydride is polyisobutylene succinic anhydride. 
     
     
         6 . The composition of  claim 5 , wherein the polyisobutylene succinic anhydride has an average molecular weight of about 600 to about 2000. 
     
     
         7 . The composition of  claim 5 , wherein the alkenyl-substituent group of the polyisobutylene succinic anhydride contains at least 30 carbon atoms. 
     
     
         8 . The composition of  claim 5 , wherein the alkenyl-substituent group of the polyisobutylene succinic anhydride has an average molecular weight of about 200 to about 2950. 
     
     
         9 . The composition of  claim 1 , wherein the polyaziridine has an average molecular weight of about 250 to about 3000. 
     
     
         10 . The composition of  claim 1 , wherein the polyaziridine is a mixture in which the predominant polyaziridine molecule contains at least about 8 nitrogen atoms per molecule. 
     
     
         11 . The composition of  claim 1 , wherein the average number of nitrogen atoms per molecule of the polyaziridine is about 7.0 to about 120.0. 
     
     
         12 . The composition of  claim 1 , wherein the alkenyl-substituted succinic anhydride and the polyaziridine are reacted at a molar ratio of about 1.0:1.0 to about 2.5:1.0. 
     
     
         13 . The composition of  claim 12 , wherein the alkenyl-substituted succinic anhydride and the polyaziridine are reacted at a molar ratio of about 1.2:1.0 to about 1.9:1.0. 
     
     
         14 . A fuel composition comprising the composition of  claim 1  in a minor amount and a major amount of a hydrocarbon. 
     
     
         15 . The fuel composition of  claim 14 , wherein the hydrocarbon boils in the diesel fuel range. 
     
     
         16 . The fuel composition of  claim 14 , wherein the composition of  claim 1  is present in an amount that is about 10 to about 10,000 parts per million. 
     
     
         17 . The fuel composition of  claim 14 , wherein the fuel composition additionally contains one or more additives selected from the group consisting of cetane improvers, friction modifiers, detergents, dispersants, antioxidants, heat stabilizers, corrosion inhibitors, dehazers, metal deactivators, antifoaming agents, cosolvents, package compatibilisers, lubricity additives, antistatic additives, cold flow additives, and demulsifiers. 
     
     
         18 . An engine comprising the composition of  claim 1 . 
     
     
         19 . A method of preventing injector fouling comprising contacting an injector with the composition of  claim 1 . 
     
     
         20 . A method of preventing deposits in an engine comprising contacting the engine with the composition of  claim 1 . 
     
     
         21 . A method of preparing the composition of  claim 1 , wherein the method comprises contacting (a) the alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 with (b) the polyaziridine having an average molecular weight of about 250 to about 5000. 
     
     
         22 . The method of  claim 21 , wherein the alkenyl-substituted succinic anhydride has an average molecular weight of about 600 to about 2000. 
     
     
         23 . The method of  claim 21 , wherein the alkenyl-substituent group of the alkenyl-substituted succinic anhydride contains at least 30 carbon atoms. 
     
     
         24 . The method of  claim 21 , wherein the alkenyl-substituted succinic anhydride is polyisobutylene succinic anhydride. 
     
     
         25 . The method of  claim 21 , wherein the polyaziridine has an average molecular weight of about 250 to about 3000. 
     
     
         26 . The method of  claim 21 , wherein the polyaziridine is a mixture in which the predominant polyaziridine molecule contains at least about 8 nitrogen atoms per molecule. 
     
     
         27 . The method of  claim 21 , wherein the average number of nitrogen atoms per molecule of the polyaziridine is about 7.0 to about 120.0. 
     
     
         28 . The method of  claim 21 , wherein the alkenyl-substituted succinic anhydride and the polyaziridine are reacted at a molar ratio of about 1.0:1.0 to about 2.5:1.0. 
     
     
         29 . The method of  claim 28 , wherein the alkenyl-substituted succinic anhydride and the polyaziridine are reacted at a molar ratio of about 1.2:1.0 to about 1.9:1.0. 
     
     
         30 . Use of a composition comprising a reaction product of (a) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (b) a polyaziridine having an average molecular weight of about 250 to about 5000.