Use of the reaction product formed from a hydrocarbyl-substituted dicarboxylic acid and a nitrogen compound to reduce fuel consumption

Abstract

The use of the reaction product formed from a hydrocarbyl-substituted dicarboxylic acid or anhydride thereof and a nitrogen compound I or a salt thereof as an additive in a fuel for reducing fuel consumption in gasoline engines.

1 . A process for reducing fuel consumption in a spark-ignition or self-igniting internal combustion engine employing a gasoline fuel comprising adding an effective amount for reducing fuel consumption of a reaction product formed from (a) a hydrocarbyl-substituted dicarboxylic acid whose hydrocarbyl radical has 8 to 250 carbon atoms, or the anhydride thereof, and (b) a nitrogen compound of the general formula (I): 
       
         
           
           
               
               
           
         
       
       or a salt of the nitrogen compound (I),
 wherein R 1  and R 2  each independently represent hydrogen or a C1- to C20-hydrocarbyl radical. 
 
     
     
         2 . The process according to  claim 1 , wherein the hydrocarbyl-substituted dicarboxylic acid (a) is based on succinic acid or the anhydride thereof. 
     
     
         3 . The process according to  claim 1 , wherein the hydrocarbyl substituent (a) is a linear or branched C8- to C40-alkyl or -alkenyl radical or a polyisobutenyl radical having 24 to 250 carbon atoms. 
     
     
         4 . The process according to  claim 1 , wherein the nitrogen compound (b) is unsubstituted aminoguanidine hydrogencarbonate. 
     
     
         5 . The process according to  claim 1 , wherein the gasoline fuel additionally comprises at least one additional additive which is different from the reaction product and acts as a detergent. 
     
     
         6 . The process according to  claim 5 , wherein the additional additive is amphiphilic and has at least one hydrophobic hydrocarbyl radical having a number-average molecular weight of 85 to 20,000, and at least one polar moiety. 
     
     
         7 . The process according to  claim 6 , wherein the additional additive comprises at least one group selected from the group consisting of:
 (Da) a mono- or polyamino group comprising up to 6 nitrogen atoms, at least one nitrogen atom of which having basic properties;   (Db) a nitro group;   (Dc) a hydroxyl group in combination with a mono- or polyamino group, at least one nitrogen atom of which having basic properties;   (Dd) a carboxyl group or its alkali metal or alkaline earth metal salt;   (De) a sulfonic acid group or its alkali metal or alkaline earth metal salt;   (Df) a polyoxy-C2-C4-alkylene group terminated by at least one hydroxyl group, mono- or polyamino group, at least one nitrogen atom having basic properties, or by at least one carbamate group;   (Dg) a carboxylic ester group;   (Dh) a group derived from succinic anhydride and comprising at least one of a hydroxyl group, an amino group, an amido group, and an imido group; and   (Di) a group obtained by Mannich reaction of at least one substituted phenol with at least one aldehyde and at least one mono- or polyamine.   
     
     
         8 . The process according to  claim 5 , wherein the gasoline fuel additionally comprises, in a minor amount, at least one carrier oil. 
     
     
         9 . The process according to  claim 1 , wherein the gasoline fuel additionally comprises, in a minor amount, at least one corrosion inhibitor. 
     
     
         10 . The process according to  claim 1 , wherein the reaction product is present in an amount of 10 to 5000 ppm by weight of the gasoline fuel. 
     
     
         11 . The process according to  claim 1 , wherein reaction product is present in an amount of 20 to 2000 ppm by weight of the gasoline fuel. 
     
     
         12 . The process according to  claim 1 , wherein reaction product is present in an amount of 30 to 1000 ppm by weight of the gasoline fuel. 
     
     
         13 . The process according to  claim 1 , wherein reaction product is present in an amount of 40 to 500 ppm by weight of the gasoline fuel. 
     
     
         14 . The process according to  claim 1 , wherein reaction product is present in an amount of 50 to 300 ppm by weight of the gasoline fuel.