Acid-free quaternized nitrogen compounds and use thereof as additives in fuels and lubricants

Abstract

The present invention relates to novel acid-free quaternized nitrogen compounds, to the preparation thereof and to the use thereof as a fuel and lubricant additive, more particularly as a detergent additive, as a wax antisettling additive (WASA) or as an additive for reducing internal diesel injector deposits (IDID); to additive packages which comprise these compounds; and to fuels and lubricants thus additized. The present invention further relates to the use of these acid-free quaternized nitrogen compounds as a fuel additive for reducing or preventing deposits in the injection systems of direct-injection diesel engines, especially in common-rail injection systems, for reducing the fuel consumption of direct-injection diesel engines, especially of diesel engines with common-rail injection systems, and for minimizing power loss in direct-injection diesel engines, especially in diesel engines with common-rail injection systems.

1 . A process for preparing quaternized nitrogen compounds, wherein
 a) a compound comprising at least one oxygen- or nitrogen-containing group reactive with the anhydride and additionally comprising at least one quaternizable amino group is added onto a polycarboxylic anhydride compound, and   b) the product from stage a) is quaternized.   
     
     
         2 . The process according to  claim 1 , wherein the polycarboxylic anhydride compound is a di-, tri- or tetracarboxylic anhydride. 
     
     
         3 . The process according to either of the preceding claims, wherein the polycarboxylic anhydride compound is the anhydride of a C 4 -C 10 -dicarboxylic acid. 
     
     
         4 . The process according to any of the preceding claims, wherein the polycarboxylic anhydride compound comprises at least one hydrocarbyl substituent having a number-average molecular weight (Mn) in the range from about 200 to 10 000, especially 350 to 5000. 
     
     
         5 . The process according to any of the preceding claims, wherein the compound reactive with the anhydride is selected from
 a) hydroxyalkyl-substituted mono- or polyamines having at least one quaternizable primary, secondary or tertiary amino group;   b) straight-chain or branched, cyclic, heterocyclic, aromatic or nonaromatic polyamines having at least one primary or secondary amino group and having at least one quaternizable primary, secondary or tertiary amino group;   c) piperazines.   
     
     
         6 . The process according to  claim 5 , wherein the compound reactive with the anhydride is selected from
 a) hydroxyalkyl-substituted primary, secondary or tertiary monoamines and hydroxyalkyl-substituted primary, secondary or tertiary diamines,   b) straight-chain or branched aliphatic diamines having two primary amino groups; di- or polyamines having at least one primary and at least one secondary amino group; di- or polyamines having at least one primary and at least one tertiary amino group; aromatic carbocyclic diamines having two primary amino groups; aromatic heterocyclic polyamines having two primary amino groups; aromatic or nonaromatic heterocycles having one primary and one tertiary amino group.   
     
     
         7 . The process according to any of the preceding claims, wherein the quaternizing agent is selected from epoxides, especially hydrocarbyl epoxides. 
     
     
         8 . The process according to  claim 7 , wherein the quaternization is effected without addition of an H + donor, especially without addition of acid. 
     
     
         9 . The process according to any of the preceding claims, wherein stage a) is performed at a temperature of less than about 80° C. and especially at a temperature in the range from about 30 to 70° C., in particular 40 to 60° C. 
     
     
         10 . The process according to any of the preceding claims, wherein stage a) is performed over a period of 1 to 120 minutes, especially 10 to 30 minutes. 
     
     
         11 . The process according to any of the preceding claims, wherein stage b) is performed at a temperature in the range from 40 to 80° C. 
     
     
         12 . The process according to any of the preceding claims, wherein stage b) is performed over a period of 1 to 10 hours. 
     
     
         13 . The process according to any of the preceding claims, wherein stage b) is performed with a hydrocarbyl epoxide as the quaternizing agent in the absence of free acid. 
     
     
         14 . The process according to any of the preceding claims, wherein the reaction according to stage a) and/or b) is effected in the absence of a solvent, especially of an organic protic solvent. 
     
     
         15 . A quaternized nitrogen compound obtainable by a process according to any of the preceding claims. 
     
     
         16 . A quaternized nitrogen compound according to  claim 15 , comprising at least one compound of the general formulae: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         in which R 1  is H or a straight-chain or branched hydrocarbyl radical which may optionally be mono- or polysubstituted by hydroxyl, carboxyl, hydrocarbyloxy and/or acyl radicals, or has one or more ether groups in the hydrocarbyl chain, and is especially H or short-chain hydrocarbyl, especially alkyl; 
         R 2  is H or alkyl; R 3  is hydrocarbyl, especially long-chain hydrocarbyl, for example a polyalkylene radical; 
         at least one of the R 4 , R 5  and R 6  radicals is a radical introduced by quaternization, especially a hydrocarbyl radical or hydroxyl-substituted hydrocarbyl radical, and the remaining radicals are selected from straight-chain or branched, cyclic hydrocarbyl radicals which are optionally mono- or polysubstituted and/or have one or more heteroatoms; 
         R 7  is H or a straight-chain or branched hydrocarbyl radical which may optionally be mono- or polysubstituted by hydroxyl, carboxyl, hydrocarbyloxy and/or acyl radicals, or has one or more ether groups in the hydrocarbyl chain, or R 7  together with one of the R 4 , R 5  and R 6  radicals forms a bridge group; 
         L 1  is a chemical bond or a straight-chain or branched alkylene group and 
         L 2  is a straight-chain or branched alkylene group which optionally bears one or more heteroatoms or substituents. 
       
     
     
         17 . A quaternized nitrogen compound according to  claim 15  or  16  which is essentially H +  donor-free, especially acid-free, and in particular comprises no inorganic acids or short-chain organic acids. 
     
     
         18 . The use of a quaternized nitrogen compound according to any of  claims 15  to  17  as a fuel additive or lubricant additive. 
     
     
         19 . The use according to  claim 18  as a detergent additive for diesel fuels. 
     
     
         20 . The use according to  claim 18  as a wax antisettling additive (WASA) for middle distillate fuels, especially diesel fuels. 
     
     
         21 . The use according to  claim 19  as an additive for reducing or preventing deposits in injection systems of direct-injection diesel engines, especially in common-rail injection systems, for reducing the fuel consumption of direct-injection diesel engines, especially of diesel engines with common-rail injection systems, and/or for minimizing power loss in direct-injection diesel engines, especially in diesel engines with common-rail injection systems. 
     
     
         22 . The use according to  claim 21  as an additive for controlling (preventing or reducing) internal diesel injector deposits (IDID). 
     
     
         23 . An additive concentrate comprising, in combination with further fuel additives, especially diesel fuel additives, at least one quaternized nitrogen compound according to any of  claims 15  and  16 . 
     
     
         24 . A fuel composition comprising, in a majority of a customary base fuel, an effective amount of at least one quaternized nitrogen compound according to either of  claims 15  and  16 . 
     
     
         25 . A lubricant composition comprising, in a majority of a customary lubricant, an effective amount of at least one quaternized nitrogen compound according to either of  claims 15  and  16 .