Use of a particular copolymer for preventing deposits on the valves of indirect injection petrol engines

Abstract

The copolymers according to the invention are very particularly effective in preventing and/or cleaning the deposits on the valves while preventing the latter from sticking at low temperature.

1 . The use, in order to prevent deposits at low temperature on the fuel intake valves in indirect injection spark ignition engines, of one or more copolymer(s) comprising:
  at least one unit of following formula (I):   
       
         
           
           
               
               
           
         
         in which: 
         u=0 or 1, 
         R 1 ′ represents a hydrogen atom or a methyl group, 
         E represents —O— or —N(Z)— or —O—CO— or —CO—O— or —NH—CO— or —CO—NH—, with Z representing H or a C 1  to C 6  alkyl group, 
         G represents a group chosen from a C 1  to C 34  alkyl group, an aromatic nucleus, an aralkyl group comprising at least one aromatic nucleus and at least one C 1  to C 34  alkyl group, and 
          at least one unit of following formula (II): 
       
       
         
           
           
               
               
           
         
         in which: 
         v=0 or 1, 
         R 1 ″ is chosen from the hydrogen atom and the methyl group, 
         Q is chosen from the oxygen atom and an —NR′— group with R′ being chosen from a hydrogen atom and C 1  to C 12  hydrocarbon chains, 
         R represents a C 1  to C 34  hydrocarbon chain which can also contain one or more nitrogen and/or oxygen atoms and/or carbonyl groups, which is substituted by at least one amino group comprising a primary, secondary or tertiary amine or quaternary ammonium functional group, and optionally one or more hydroxyl groups. 
       
     
     
         2 . The use of a copolymer as recited in  claim 1 , in which the amino group present in the group R of the formula (II) is chosen from:
 the groups having at least one amine, imine, amidine, guanidine, aminoguanidine or biguanidine functional group, such as alkylamines, polyalkylenepolyamines, polyalkylenimines, alkylimines, alkylamidines, alkylguanidines and alkylbiguanidines, it being possible for the alkyl substituent to be linear or branched, cyclic or acyclic, and preferably having from 1 to 34 carbon atoms, more preferentially from 1 to 12 carbon atoms, and the quaternized forms of these groups; and   monocyclic or polycyclic heterocyclic groups, having from 3 to 34 atoms, preferably from 5 to 12 atoms, more preferentially from 6 to 10 atoms, and at least one nitrogen atom, it being understood that the polycyclic heterocyclic groups have, optionally, fused rings.   
     
     
         3 . The use of a copolymer as recited in  claim 1 , in which the group R of the formula (II) is represented:
 when v has the value 1, by the formula (V):
   L-R′ 2   (V)
 
   when v has the value 0, by the formula (V) or the formula (V′):
   L-R′ 2   (V)
 
   L-  (V′)
 
 in which formulae (V) and (V′): 
   R 2 ′ is chosen from C 1  to C 34  hydrocarbon chains, optionally substituted by at least one hydroxyl group, and
  L is chosen from the group consisting of: 
    the following groups:
 amine: —NH 2 ; —NHR a , —NR a R b ; 
 imine: —HC═NH; —HC═NR a ; —N═CH 2 , —N═CR a H; —N═CR a R b ; 
 amidine: —(C═NH)—NH 2 ; —(C═NH)—NR a H; —(C═NH)—NR a R b ; —(C═NR a )—NH 2 ; —(C═NR a )—NR b H; —(C═NR a )—NR b R c ; —N═CH(NH 2 ); —N═CR a (NH 2 ); —N═CH(NR a H); —N═CR a (NR a H); —N═CH(NR a R b ); —N═CR a (NR b R c ); 
 guanidine: —NH—(C═NH)—NH 2 ; —NH—(C═NH)—NHR a ; —N═C(NH 2 ) 2 ; —N═C(NR a H) 2 ; —N═C(NR a R b ) 2 ; —N═C(NR a H)(NR b H); 
 aminoguanidine: —NH—(C═NH)—NH—NH 2 ; —NH—(C═NH)—NH—NHR a ; —N═C(NH 2 )(NH—NH 2 ); —N═C(NR a H)(NH—NH 2 ); —N═C(NR a H)(NR′—NH 2 ); —N═C(NR a R b )(NH—NH 2 ); —N═C(NR a R b )(NR a —NH 2 ); 
 biguanidine: —NH—(C═NH)—NH—(C═NH)—NH 2 ; —NH—(C═NH)—NH—(C═NH)—NHR a ; —N═C(NH 2 )—NH—(C═NH)—NH 2 ; —N═C(NH 2 )—NH—(C═NR a )—NH 2 ; —N═C(NH 2 )—NH—(C═NH)—NR a H; —N═C(NH 2 )—NH—(C═NR a )—NR b H; —N═C(NH 2 )—NH—(C═NH)—NR a R b ; —N═C(NH 2 )—NH—(C═NR a )—NR b R c ; —N═C(NR a H)—NH—(C═NH)—NH 2 ; —N═C(NR a H)—NH—(C═NR b )—NH 2 ; —N═C(NR a H)—NH—(C═NH)—NR b H; —N═C(NR a H)—NH—(C═NR b )—NR c H; —N═C(NR a H)—NH—(C═NH)—NR b R c ; —N═C(NR a H)—NH—(C═NR b )—NR c R d ; —N═C(NR a R b )—NH—(C═NH)—NH 2 ; —N═C(NR a R b )—NH—(C═NR c )—NH 2 ; —N═C(NR a R b )—NH—(C═NH)—NR c H; —N═C(NR a R b )—NH—(C═NR c )—NR d H; —N═C(NR a R b )—NH—(C═NH)—NR c R d ; —N═C(NR a R b )—NH—(C═NR c )—NR d R e ; 
 the quaternized forms of the above groups, when these contain at least one quaternizable nitrogen atom; and 
 polyamine and polyalkylenepolyamine groups, in particular those of formulae —NH—(R f —NH) k —H; —NH—(R f —NH) k —R a ; 
 with R a , R b , R c , R d  and R e  representing, independently of one another, a C 1 -C 34 , preferably C 1 -C 12 , alkyl group, optionally comprising one or more NH 2  functional groups and one or more —NH— bridges; 
 R f  represents a C 1 -C 6 , preferably C 2 -C 4 , alkyl group; k represents an integer ranging from 1 to 20, preferably from 2 to 12. 
   
     
     
         4 . The use of a copolymer as recited in  claim 1 , in which the copolymer contains units of formula (II) comprising a group R containing at least one quaternary ammonium functional group. 
     
     
         5 . The use of a copolymer as recited in  claim 4 , in which from 5 mol % to 95 mol % of the units of formula (II) of the copolymer comprise, in the group R, at least one quaternary ammonium functional group, preferably from 10% to 90%, more preferentially from 20% to 80% and more preferentially still from 40% to 60%, with respect to the total molar amount of units of formula (II) in the copolymer. 
     
     
         6 . The use of a copolymer as recited in  claim 1 , in which the quaternary ammonium functional group(s) optionally present in the group R of the units of formula (II) is (are) represented by one of the following formulae (III) and (IV): 
       
         
           
           
               
               
           
         
         in which: 
         X −  is chosen from hydroxide or halide ions and organic anions, preferably organic anions, 
         R 2  is chosen from C 1  to C 34  hydrocarbon chains, optionally substituted by at least one hydroxyl group, 
         R 3 , R 4  and R 5  are identical or different and are chosen independently from C 1  to C 18  hydrocarbon chains, it being understood that the R 3 , R 4  and R 5  groups can contain one or more groups chosen from: a nitrogen atom, an oxygen atom and a carbonyl group and that the R 3 , R 4  and R 5  groups can be connected together in pairs to form one or more rings, 
         R 6  and R 7  are identical or different and are chosen independently from C 1  to C 18  hydrocarbon chains, it being understood that the R 6  and R 7  groups can contain one or more groups chosen from: a nitrogen atom, an oxygen atom and a carbonyl group and that the R 6  and R 7  groups can be connected together to form a ring. 
       
     
     
         7 . The use of a copolymer as recited in  claim 6 , in which the quaternary ammonium functional group(s) present in the group R of the units of formula (II) is (are) represented by the formula (III), in which:
 X −  is chosen from organic anions, preferably conjugate bases of carboxylic acids,   R 2  is chosen from C 1  to C 34  hydrocarbon chains, preferably C 1  to C 18  alkyl groups,   R 3 , R 4  and R 5  are identical or different and are chosen independently from C 1  to C 18  hydrocarbon chains, optionally substituted by at least one hydroxyl group, it being understood that at least one of the R 3 , R 4  and R 5  groups contains one or more hydroxyl group(s).   
     
     
         8 . The use of a copolymer as recited in  claim 1 , in which, in the formula (I), the group G is a C 4  to C 34  alkyl. 
     
     
         9 . The use of a copolymer as recited in  claim 1 , in which, in the formula (I), R 1 ′ is a hydrogen atom. 
     
     
         10 . The use of a copolymer as recited in  claim 1 , in which, in the formula (I), the group E is chosen from: —O— and —N(Z)—, with Z representing H or a C 1  to C 6  alkyl group. 
     
     
         11 . The use of a copolymer as recited in  claim 1 , in which, in the formula (I), the group E is chosen from: —O—CO— and —NH—CO—; preferably, the group E is the —O—CO— group, it being understood that the group E=—O—CO— is connected to the vinyl carbon by the oxygen atom and that the group E=—NH—CO— is connected to the vinyl carbon by the nitrogen atom. 
     
     
         12 . The use of a copolymer as recited in  claim 1 , in which, in the formula (I), the group E is chosen from: —CO—O— and —CO—NH—; preferably the group E is the —CO—O— group, it being understood that the group E is connected to the vinyl carbon by the carbon atom. 
     
     
         13 . The use of a copolymer as recited in  claim 1 , in which the copolymer is chosen from block copolymers and random copolymers; preferably, the copolymer is a block copolymer. 
     
     
         14 . The use of a copolymer as recited in  claim 13 , in which the copolymer is a block copolymer comprising at least:
  a block A corresponding to the following formula (XI):   
       
         
           
           
               
               
           
         
         in which:
 p is an integer ranging from 2 to 100, preferably ranging from 5 to 80, preferably ranging from 10 to 70, more preferentially ranging from 20 to 60, and 
 R 1 ′, u, E and G are as defined in  claim 1 , and 
 
          a block B corresponding to the following formula (XII): 
       
       
         
           
           
               
               
           
         
         in which:
 n is an integer ranging from 2 to 50, preferably from 3 to 40, more preferentially from 4 to 20, more preferentially still from 5 to 10, 
 
         R 1 ″, v, Q and R are as defined in  claim 1 . 
       
     
     
         15 . The use of a copolymer as recited in  claim 14 , in which, from 5 mol % to 95 mol % of the units of the block B comprise a group R containing at least one quaternary ammonium functional group. 
     
     
         16 . The use of a copolymer as recited in  claim 15 , in which the block B comprises from 5 mol % to 95 mol % of units corresponding to the formula (XIII): 
       
         
           
           
               
               
           
         
         in which:
 R 1 ″ is chosen from the hydrogen atom and the methyl group, 
 Q is chosen from the oxygen atom and the —NR′— group, with R′ being chosen from a hydrogen atom and C 1  to C 12  hydrocarbon chains, 
 X −  is chosen from organic anions, preferably conjugate bases of carboxylic acids, 
 R 2  is chosen from C 1  to C 34  hydrocarbon chains, preferably C 1  to C 18  alkyl groups, 
 R 3 , R 4  and R 5  are identical or different and are chosen independently from C 1  to C 18  hydrocarbon chains, optionally substituted by at least one hydroxyl group, it being understood that at least one of the R 3 , R 4  and R 5  groups contains at least one hydroxyl group. 
 
       
     
     
         17 . The use of a copolymer as recited in  claim 15 , in which:
 the block A consists of a chain of structural units derived from a C 1 -C 34  alkyl (meth)acrylate monomer, and   the block B consists of a chain of structural units derived from alkyl (meth)acrylate or alkyl(meth)acrylamide monomers, 5 mol % to 95 mol % of which have an alkyl radical consisting of a C 1  to C 34  hydrocarbon chain substituted by a quaternary ammonium group and optionally one or more hydroxyl groups, and 5 mol % to 95 mol % of which have an alkyl radical consisting of a C 1  to C 34  hydrocarbon chain substituted by a group chosen from primary, secondary or tertiary amines, preferably tertiary amines, and optionally one or more hydroxyl groups.   
     
     
         18 . The use of a copolymer as recited in  claim 1 , in which the copolymer is incorporated in a liquid fuel in a total content of at least 5 ppm by weight, preferably of at least 10 ppm, more preferentially at a content of 10 to 5000 ppm, more preferentially still of 20 to 2000 ppm and better still of 50 to 1000 ppm. 
     
     
         19 . The use of a copolymer as recited in  claim 1 , for preventing the sticking of said valves, which is determined according to the standardized method CEC F-16-T96. 
     
     
         20 . A process for keeping clean, at low temperature, the fuel intake valves in an indirect injection spark ignition engine comprising at least the following stages:
 the preparation of a fuel composition by additivation of a fuel with a copolymer as defined in  claim 1 , then   the injection of said fuel composition into the spark ignition engine.