Fuel additives with improved miscibility and reduced tendency to form emulsions

Abstract

This invention relates to an additive package containing an organic solvent, a detergent additive and a reaction product mixture obtained by reacting a carboxylic acid compound of formula (I): R 1 COOR 2 with an alkanol amine of formula (II): NHR 3 R 4 to form a reaction product containing a polysubstituted alkanol amine derivative, where the reaction is performed by: (a) heating the carboxylic acid of formula (I) to a first temperature; (b) adding thereto the alkanol amine of formula (II) under controlled conditions avoiding an increase of temperature above the first temperature range; (c) maintaining temperature in the first temperature range; and (d) increasing the temperature of the reaction mixture to a second temperature in a second temperature range of 160 to 210° C. and allowing further reaction of residual free carboxylic acid molecules with any reactive group in the reaction mixture.

1 . An additive package, comprising:
 an organic solvent;   a detergent additive; and   a reaction product mixture, obtained by reacting a carboxylic acid compound of formula (I) with an alkanol amine of formula (II) to form a reaction product comprising a poly-substituted alkanol amine derivative:
   R 1 COOR 2   (I);
 
   NHR 3 R 4   (II),
 
   wherein:   R 1  is an aliphatic C 1 -C 30 -hydrocarbon radical;   R 2  is hydrogen or alkyl, mono- or polyhydroxyalkyl, or ammonium;   R 3  and R 4  independently of each other represent hydrogen or a residue of formula (III):
   —[(CH 2 ) x NH] y (CH 2 ) z R 5   (III);
 
   R 3  and R 4  are not both hydrogen atoms;   x and z are independently from each other integers from 1 to 6;   y is 0 or an integer of 1 to 3;   R 5  is hydroxyl or a residue of formula (IV):
   —NH(CH 2 ) z′ OH  (IV);
 
   z′ is an integer from 1 to 6; and   the reaction is performed by:   (a) heating the carboxylic acid of formula (I) to a first temperature in a first temperature range of 100 to 155° C.;   (b) adding thereto the alkanol amine of formula (II) under controlled conditions avoiding an increase of temperature above the first temperature range;   (c) maintaining temperature in the first temperature range; and   (d) increasing the temperature of the reaction mixture to a second temperature in a second temperature range of 160 to 210° C. and allowing further reaction of residual free carboxylic acid molecules with any reactive group in the reaction mixture,   such that a molar ratio of carboxyl groups of the carboxylic acid of formula (I) to a molar sum of OH and NH groups of the alkanol amine of formula (II) is in a range of about 1.8:3 to 3:3.   
     
     
         2 . The additive package of  claim 1 , comprising said polysubstituted alkanol amine derivative in a proportion of more than 20 wt. %, based on a total weight of the product. 
     
     
         3 . The additive package of  claim 1 , wherein the molar ratio of carboxyl groups of the carboxylic acid of formula (I) to the molar sum of OH and NH groups of the alkanol amine of formula (II) is in a range of about 1.9:3 to 2.5:3. 
     
     
         4 . The additive package of  claim 1 , wherein the first temperature during at least one of (b), (c) and (d) is maintained in a range of 120 to 135° C. 
     
     
         5 . The additive package of  claim 1 , wherein the second temperature in (d) is maintained in a range of 175 to 190° C. 
     
     
         6 . The additive package of  claim 1 , wherein:
 x and z are independently from each other integers from 1, 2 or 3;   y is 0 or 1; and   z′ is an integer of 1, 2, or 3.   
     
     
         7 . The additive package of  claim 1 , wherein the compound of formula (I) is at least one selected from the group consisting of a C 8 -C 30 -carboxylic acid and an alkyl ester thereof. 
     
     
         8 . The additive package of  claim 1 , wherein the compound of formula (II) is a polyaminoalkanol,
 wherein:   one of R 3  and R 4  is hydrogen and the other is the residue of formula (III);   x is 2 or 3;   y is 0 or 1;   z is 2 or 3; and   R 5  is hydroxyl or the residue of formula (IV).   
     
     
         9 . A method of improving a storage stability of an additive package, the method comprising adding to said package at least one reaction product mixture obtained by reacting a carboxylic acid compound of formula (I) with an alkanol amine of formula (II) to form a reaction product comprising a polysubstituted alkanol amine derivative:
   R 1 COOR 2   (I);
     NHR 3 R 4   (II),
   wherein:   R 1  is an aliphatic C 1 -C 30 -hydrocarbon radical;   R 2  is hydrogen or alkyl, mono- or polyhydroxyalkyl, or ammonium;   R 3  and R 4  independently of each other represent hydrogen or a residue of formula (III):
   —[(CH 2 ) x NH] y (CH 2 ) z R 5   (III);
 
   R 3  and R 4  are not both hydrogen atoms;   x and z are independently from each other integers from 1 to 6;   y is 0 or an integer of 1 to 3;   R 5  is hydroxyl or a residue of formula (IV):
   —NH(CH 2 ) z′ OH  (IV);
 
   z′ is an integer from 1 to 6;   the reaction is performed by:   (a) heating the carboxylic acid of formula (I) to a first temperature in a first temperature range of 100 to 155° C.;   (b) adding thereto the alkanol amine of formula (II) under controlled conditions avoiding an increase of temperature above the first temperature range;   (c) maintaining temperature in the first temperature range; and   (d) increasing the temperature of the reaction mixture to a second temperature in a second temperature range of 160 to 210° C. and allowing further reaction of residual free carboxylic acid molecules with any reactive group in the reaction mixture,   such that a molar ratio of carboxyl groups of the carboxylic acid of formula (I) to a molar sum of OH and NH groups of the alkanol amine of formula (II) is in a range of about 1.8:3 to 3:3; and   the additive package comprises a detergent additive in an organic solvent.   
     
     
         10 . The method of  claim 9 , wherein the detergent additive is at least one selected from the group consisting of a polyalkene monoamine, a polyalkene Mannich amine and a polyalkene succinimide. 
     
     
         11 . A reaction product mixture, obtained by reacting a carboxylic acid compound of formula (I) with an alkanol amine of formula (II) to form a reaction product comprising a polysubstituted alkanol amine derivative:
   R 1 COOR 2   (I);
     NHR 3 R 4   (II),
   wherein:   R 1  is an aliphatic C 1 -C 30 -hydrocarbon radical;   R 2  is hydrogen or alkyl, mono- or polyhydroxyalkyl, or ammonium;   R 3  and R 4  independently of each other represent hydrogen or a residue of formula (III):
   —[(CH 2 ) x NH] y (CH 2 ) n R 5   (III),
 
   such that R 3  and R 4  are not both hydrogen atoms;   x and z are independently from each other integers from 1 to 6;   y is 0 or an integer of 1 to 3;   R 5  is hydroxyl or a residue of formula (IV):
   —NH(CH 2 ) z′ OH  (IV);
 
   z′ is an integer from 1 to 6; and   the reaction is performed by:   (a) heating the carboxylic acid of formula (I) to a first temperature in a first temperature range of 100 to 155° C.;   (b) adding thereto the alkanol amine of formula (II) under controlled conditions avoiding an increase of temperature above the first temperature range;   (c) maintaining temperature in the first temperature range; and   (d) increasing the temperature of the reaction mixture to a second temperature in a second temperature range of 160 to 210° C. and allowing further reaction of residual free carboxylic acid molecules with any reactive group in the reaction mixture,   such that a molar ratio of carboxyl groups of the carboxylic acid of formula (I) to a molar sum of OH and NH groups of the alkanol amine of formula (II) is in a range of about 1.8:3 to 3:3.