Use of specific copolymers for improving the cold properties of fuels or combustibles

Abstract

The subject matter of the present invention is the use, for improving the cold-resistance properties of a fuel or combustible composition, of one or more copolymers comprising:—at least one unit of formula (I): in which R1 is a hydrogen atom or a methyl group; X is —O—CO—, or —CO—O— or —NH—OO— or —CO—NH—; R2 is a C6 to C24 alkyl group; and at least one unit of formula (II): in which R is a substituted or unsubstituted imidazole ring. The invention also relates to compositions of additives containing such a polymer, and also fuel or combustible compositions to which such polymers have been added, preferably in combination with a cold flow improver (CFI) additive or a paraffin anti-settling additive (WASA).

1 . A use, for improving the cold-resistance properties of a fuel or combustible composition, of one or more copolymers comprising:
 at least one unit of the following formula (I):   
       
         
           
           
               
               
           
         
         wherein 
         R 1  is a hydrogen atom or a methyl group, 
         X is —O—CO—, or —CO—O— or —NH—CO— or —CO—NH—, and 
         R 2  is a C 6  to C 24  alkyl group; and
 at least one unit of the following formula (II): 
 
       
       
         
           
           
               
               
           
         
         wherein R is a substituted or unsubstituted imidazole ring. 
       
     
     
         2 . The use according to  claim 1 , characterised in that the group X of formula (I) is selected from: —CO—O— and —CO—NH—, it being understood that the group X is linked to the vinyl carbon by the carbon atom, and preferably the group X of formula (I) is the group —CO—O—. 
     
     
         3 . The use according to  claim 1 , characterised in that the group R2 of formula (I) is a linear or branched C 8  to C 24 , preferably C 8  to C 14  or C 16  to C 22 , more preferentially C 12  to C 14  or C 18  to C 22  and more preferably C 18  to C 22  acyclic alkyl radical. 
     
     
         4 . The use according to  claim 1 , characterised in that the unit of formula (II) is N-vinylimidazole. 
     
     
         5 . The use according to  claim 1 , characterised in that said copolymer contains from 1 to 50% in moles of units of formula (II), preferably from 5 to 40% in moles, more preferentially from 10 to 30% in moles, and more preferably from 10 to 25% in moles. 
     
     
         6 . The use according to  claim 1 , characterised in that said copolymer contains only units of formula (I) and units of formula (II). 
     
     
         7 . The use according to  claim 1 , characterised in that said copolymer is a random copolymer, or a block copolymer, and preferably said copolymer is a random copolymer. 
     
     
         8 . The use of a copolymer according to  claim 1 , for lowering the cold filter plugging point measured as per the standard NF EN 116 and/or the pour point measured as per the standard ASTM D 7346, and/or for delaying or preventing the settling of crystals, and preferably for lowering the cold filter plugging point measured as per the standard NF EN 116. 
     
     
         9 . The use according to  claim 1 , characterised in that said copolymer is used in combination with at least one cold flow improver additive, preferably selected from copolymers and terpolymers of ethylene and vinyl and/or acrylic ester(s), alone or in a mixture. 
     
     
         10 . An additive composition comprising a copolymer as defined in  claim 1 , and one or more cold-resistance additive(s) different from the copolymers comprising units of formula (I) and units of formula (II), preferably selected from cold flow improver additives, paraffin anti-settling additives and/or dispersants, and mixtures of these additives. 
     
     
         11 . The additive composition according to  claim 10 , characterised in that it contains at least one cold flow improver additive selected from the copolymers of ethylene and vinyl ester(s), alone or in a mixture; preferably selected from ethylene/vinyl acetate (EVA) copolymers, ethylene/vinyl propionate (EVP) copolymers and terpolymers of ethylene, vinyl acetate and another vinyl ester; more preferentially selected from ethylene/vinyl acetate (EVA) copolymers and mixtures thereof with a terpolymer of ethylene, vinyl acetate and another vinyl ester, such as vinyl neodecanoate in particular. 
     
     
         12 . The additive composition according to  claim 1 , characterised in that the weight ratio between the content of the copolymer(s) according to the invention, on one hand, and the content of copolymer(s) of ethylene and vinyl ester(s), on the other, is within the range from 0.01:100 to 20:100, preferably from 0.1:100 to 10:100, and more preferably from 0.5:100 to 5:100. 
     
     
         13 . A fuel or combustible composition, comprising:
 (1) at least one hydrocarbon cut derived from one or more sources selected from the group consisting of mineral, animal, plant and synthetic sources, and   (2) at least one copolymer as defined in  claim 1 .   
     
     
         14 . The composition according to  claim 13 , characterised in that it contains said copolymer(s) at a content of at least 0.0001% by weight, preferably at a content ranging from 0.0001 to 0.01% by weight, preferably from 0.0002 to 0.005% by weight, and more preferably from 0.0003 to 0.003% by weight, with respect to the total weight of the composition. 
     
     
         15 . The composition according to  claim 13 , characterised in that it further comprises at least one cold flow improver additive selected from the copolymers of ethylene and vinyl ester(s), alone or in a mixture. 
     
     
         16 . The composition according to  claim 14 , characterised in that it further comprises at least one cold flow improver additive selected from ethylene/vinyl acetate (EVA) copolymers, ethylene/vinyl propionate (EVP) copolymers and terpolymers of ethylene, vinyl acetate and another vinyl ester; more preferentially selected from ethylene/vinyl acetate (EVA) copolymers and mixtures thereof with a terpolymer of ethylene, vinyl acetate and another vinyl ester, such as vinyl neodecanoate in particular.