Quaternized nitrogen compounds and use thereof as additives in fuels and lubricants

Abstract

The present invention relates to novel quaternized nitrogen compounds, to the preparation thereof and to the use thereof as a fuel and lubricant additive, more particularly as a detergent additive; to additive packages which comprise these compounds; and to fuels and lubricants thus additized. The present invention further relates to the use of these 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 fuel composition comprising, in a majority of a customary fuel, a proportion of at least one reaction product comprising a quaternized nitrogen compound, or a fraction thereof which comprises a quaternized nitrogen compound and is obtained from the reaction product by purification, said reaction product being obtainable by
 a) reacting a hydrocarbyl-substituted polycarboxylic acid compound with a compound comprising at least one oxygen or nitrogen group reactive, especially capable of addition or condensation, with the polycarboxylic acid, and comprising at least one quaternizable amino group, to obtain a quaternizable hydrocarbyl-substituted polycarboxylic acid compound, and   b) subsequent reaction thereof with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, especially of a mono- or dicarboxylic acid, or of an aliphatic polycarboxylic acid, especially dicarboxylic acid.   
     
     
         2 . A fuel composition comprising, in a majority of a customary fuel, a proportion of at least one reaction product comprising a quaternized nitrogen compound, or a fraction thereof which comprises a quaternized nitrogen compound and is obtained from the reaction product by purification, said reaction product being obtainable by
 reacting a quaternizable hydrocarbyl-substituted polycarboxylic acid compound comprising at least one quaternizable amino group with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group,   said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, especially of a mono- or dicarboxylic acid, or of an aliphatic polycarboxylic acid, especially dicarboxylic acid.   
     
     
         3 . The fuel composition according to either of the preceding claims, wherein about 1.1 to about 2.0 or about 1.25 to about 2.0 equivalents of quaternizing agent are used per equivalent of quaternizable tertiary nitrogen atom. 
     
     
         4 . The fuel composition according to any of the preceding claims, wherein the hydrocarbyl-substituted polycarboxylic acid compound is a polyisobutenylsuccinic acid or an anhydride thereof, said acid having a bismaleation level of less than about 20% or less than about 15%. 
     
     
         5 . The fuel composition according to any of the preceding claims, wherein the quaternizing agent is a compound of the general formula 1
   R 1 OC(O)R 2   (1)
   in which   R 1  is a lower alkyl radical and   R 2  is an optionally substituted monocyclic aryl or cycloalkyl radical, where the substituent is selected from OH, NH 2 , NO 2 , C(O)OR 3 , and R 1 OC(O)—, in which R 1  is as defined above and R 3  is H or R 1 .   
     
     
         6 . The fuel composition according to any of the preceding claims, wherein the quaternizing agent is a compound of the general formula 2
   R 1 OC(O)-A-C(O)OR 1a   (2)
   in which   R 1  and R 1a  are each independently a lower alkyl radical and   A is hydrocarbylene, such as especially alkylene or alkenylene.   
     
     
         7 . The fuel composition according to any of the preceding claims, wherein the quaternized nitrogen compound has a number-average molecular weight in the range from 500 to 5000, especially 800 to 3000 or 900 to 1500. 
     
     
         8 . The fuel composition according to any of the preceding claims, wherein the quaternizing agent is selected from alkyl salicylates, dialkyl phthalates and dialkyl oxalates. 
     
     
         9 . The fuel composition according to  claim 1 , wherein the compound which is reactive, especially capable of addition or condensation, with the polycarboxylic acid and comprises an oxygen or nitrogen group and at least one quaternizable amino group 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.   
     
     
         10 . The fuel composition according to  claim 9 , wherein the compound which is reactive, especially capable of addition or condensation, with the polycarboxylic acid and comprises an oxygen or nitrogen group and at least one quaternizable amino group 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.   
     
     
         11 . The fuel composition according to any of the preceding claims, selected from diesel fuels, biodiesel fuels, gasoline fuels and alkanol-containing gasoline fuels. 
     
     
         12 . A reaction product obtainable by a process as defined in any of the preceding claims or quaternizable nitrogen compound obtained from the reaction product. 
     
     
         13 . A process for preparing a quaternized nitrogen compound according to  claim 12 , comprising the reaction of a quaternizable hydrocarbyl-substituted polycarboxylic acid compound comprising at least one tertiary quaternizable amino group with a quaternizing agent which converts the at least one tertiary amino group to a quaternary ammonium group,
 said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, especially of a mono- or dicarboxylic acid, or of an aliphatic polycarboxylic acid, especially dicarboxylic acid.   
     
     
         14 . The use of a reaction product or of a quaternized nitrogen compound according to  claim 12  or of a compound prepared according to  claim 13  as a fuel additive. 
     
     
         15 . The use according to  claim 14  as an additive 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. 
     
     
         16 . The use according to  claim 14  as a gasoline fuel additive for reducing the level of deposits in the intake system of a gasoline engine, such as especially DISI (direct injection spark ignition) and PFI (port fuel injector) engines. 
     
     
         17 . The use according to  claim 14  as a diesel fuel additive, especially as a cold flow improver, as a wax antisettling additive (WASA) or as an additive for reducing the level of and/or preventing deposits in the intake systems, such as especially the internal diesel injector deposits (IDIDs), and/or valve sticking in direct-injection diesel engines, especially in common-rail injection systems. 
     
     
         18 . An additive concentrate comprising, in combination with further diesel fuel or gasoline fuel additives, especially diesel fuel additives, at least one quaternized nitrogen compound as defined in  claim 12  or prepared according to  claim 13 .