Use of a fuel composition comprising three additives for cleaning the internal parts of petrol engines

Abstract

The present invention relates to the use, for reducing deposits in the internal parts of a spark ignition engine, of a fuel composition comprising at least three additives: a quaternary ammonium salt, a non-quaternary polyisobutylene succinimide and a Mannich base which is different from the other additives. The composition is such that the mass ratio of the quantity of the first additive to the quantity of the second additive is in the range from 0.2:1 to 2.5:1.

1 . A use, for reducing and/or preventing deposits along internal parts of a spark ignition engine, of a fuel composition comprising:
 (1) at least one first additive consisting of a quaternary ammonium salt,   (2) at least one second additive consisting of a non-quaternary polyisobutylene succinimide,   (3) at least one third additive different from the additives (1) and (2), consisting of a Mannich base, and   wherein the mass ratio of the amount of the first additive to the amount of the second additive is in the range from 0.2:1 to 2.5:1.   
     
     
         2 . The use according to  claim 1 , wherein the mass ratio of the amount of the first additive to the amount of the second additive is in the range from 1:1 to 2:1. 
     
     
         3 . The use according to  claim 1 , wherein the first additive (1) consisting of quaternary ammonium salt is obtained by reacting, with a quaternisation agent, a nitrogen compound comprising a tertiary amine function, this compound being the product of the reaction of an acylating agent substituted with a hydrocarbon group and a compound comprising at least one tertiary amine group and at least one group selected from primary amines, secondary amines and alcohols. 
     
     
         4 . The use according to  claim 3 , wherein the acylating agent substituted with a hydrocarbon group is selected from mono- or poly-carboxylic acids and derivatives thereof. 
     
     
         5 . The use according to  claim 3 , wherein the acylating agent substituted with a hydrocarbon group is a polyisobutenyl succinic anhydride. 
     
     
         6 . The use according to  claim 3 , wherein the compound comprising at least one tertiary amine group and at least one group selected from primary amines, secondary amines and alcohols is selected from amines of following formula (I) or (II): 
       
         
           
           
               
               
           
         
         wherein: 
         R6 and R7 are identical or different and represent, independently of each other, an alkyl group having from 1 to 22 carbon atoms; 
         X is an alkylene group having from 1 to 20 carbon atoms; 
         m is an integer between 1 and 5; 
         n is an integer from 0 to 20; and 
         R8 is a hydrogen atom or a C 1 -C 22  alkyl group. 
       
     
     
         7 . The use according to  claim 3 , wherein the quaternisation agent is selected from the group consisting of dialkyl sulphates, carboxylic acid esters; alkyl halides, benzyl halides, hydrocarbon carbonates, and hydrocarbon epoxides optionally in mixture with an acid, alone or in mixture. 
     
     
         8 . The use according to  claim 1 , wherein the additive (1) is selected from polyisobutylene succinimides functionalised with a quaternary ammonium group. 
     
     
         9 . The use according to  claim 1 , wherein the additive (2) consisting of a non-quaternary polyisobutylene succinimide results from the condensation:
 of a compound A consisting of a carboxylic diacid substituted with a polyisobutylene group or of an anhydride of such a diacid;   with a compound B consisting of a primary polyamine of general formula (VI) hereafter:
   H 2 N—[—(CHR1-(CH 2 ) p —CHR 2 ) n —NH] m —H  (VI)
 
   wherein R1 and R2, which are identical or different, represent hydrogen or a hydrocarbon group comprising from 1 to 4 carbon atoms, n is an integer ranging from 1 to 3, m is an integer ranging from 1 to 10; and p is an integer equal to 0 or 1.   
     
     
         10 . The use according to  claim 9 , wherein said additive (2) is obtained by condensation of compound A with compound B used in such amounts that the molar ratio A/B is in the range from 1:1 to 1:3. 
     
     
         11 . The use according to  claim 1 , wherein the additive (3) consisting of a Mannich base is obtained by reacting a phenol substituted with a hydrocarbon group, an aldehyde and an amine, the hydrocarbon substituent of said phenol comprising from 6 to 400 carbon atoms. 
     
     
         12 . The use according to  claim 1 , wherein the fuel contains a base from one or more sources selected from the group consisting of mineral, animal, vegetable and synthetic sources. 
     
     
         13 . The use according to  claim 1 , wherein the content of each additive (1) and (2) ranges from 5 to 10,000 ppm by weight, based on the total weight of the fuel composition. 
     
     
         14 . The use according to  claim 1 , wherein the content of the additive (3) ranges from 5 to 10,000 ppm by weight, based on the total weight of the fuel composition. 
     
     
         15 . (canceled) 
     
     
         16 . The use according to  claim 1 , where such use is for keeping clean (keep-clean effect) and/or cleaning up (clean-up effect) deposits in the internal parts of the spark ignition engine selected from the following: the combustion chamber and the fuel injection system. 
     
     
         17 . The use according to  claim 1 , where such use is for preventing and/or reducing coke and/or soap deposits on the fuel intake valves in the spark ignition engine, the spark ignition engine being an indirect injection spark ignition engine. 
     
     
         18 . The use according to  claim 1 , where such use is for preventing and/or reducing valve-sticking of fuel intake valves in the spark ignition engine, the spark ignition engine being an indirect injection spark ignition engine. 
     
     
         19 . The use according to  claim 1 , wherein the additive composition is used in the fuel to reduce fuel consumption of the engine (“Fuel Eco” action) and/or minimise power loss of said engine, and/or reduce pollutant emissions. 
     
     
         20 . (canceled) 
     
     
         21 . A use, for improving detergency properties of a gasoline fuel, of a fuel concentrate comprising at least the additives (1), (2) and (3), as defined in  claim 1 , in mixture with an organic liquid, said organic liquid being inert towards the first, second and third additive, and miscible with said fuel. 
     
     
         22 . A process for keeping clean and/or cleaning up at least one of the internal parts of a spark ignition engine or gasoline internal combustion engine, comprising at least the following steps:
 preparing a fuel composition by additivating a fuel with at least the additives (1), (2) and (3), as defined in  claim 1 , and then   combusting said fuel composition in said spark ignition engine.