EP3487962A1

EP3487962A1 - Use of copolymers to improve the properties of fuels when cold

Info

Publication number: EP3487962A1
Application number: EP17751441.1A
Authority: EP
Inventors: Julie Prevost
Original assignee: Total Marketing Services SA
Current assignee: TotalEnergies Marketing Services SA
Priority date: 2016-07-21
Filing date: 2017-07-20
Publication date: 2019-05-29
Also published as: FR3054240B1; FR3054240A1; WO2018015667A1

Abstract

The invention relates to the use of copolymers and additive concentrates containing such copolymers to improve the low-temperature properties of fuels, also referred to as cold-resistance properties, in particular the flow properties thereof during storage and/or use at low temperature. The invention also relates to the use of copolymers as an anti-sedimentation additive and the use of copolymers to expand the flow improving effect of the cold flow improver (CFI) by raising the cold filter plugging point (CFFP) of the fuel.

Description

USE OF COPOLYMERS FOR IMPROVING THE COLD PROPERTIES OF

FUELS OR FUELS

The present invention relates to the use of copolymers and additive concentrates containing such copolymers for improving the properties of low-temperature fuels or fuels, also known as cold-holding properties, in particular their flow properties during storage and / or their use at low temperature. The present invention relates in particular to the use of copolymers to enhance the fluidizing (flow) effect of the cold-flow additive (CFI) by improving the Filterability Limit Temperature (TLF) of the fuel or fuel.

The present invention also relates to the use of copolymers as an anti-sedimentation additive, also called WASA or "Wax Anti-Settling Additive", for retarding and / or preventing the sedimentation of crystals of n-alkyl, isoalkyl or n-alkyl substituted compounds. alkenyl.

The present invention also relates to fuel and fuel compositions additive with a cold-flow additive (CFI) comprising such copolymers.

STATE OF THE PRIOR ART

Fuels containing n-alkyl, iso-alkyl or n-alkenyl substituted compounds such as paraffin waxes are known to exhibit deteriorated flow properties at low temperatures, typically below 0 ° C. In particular, it is known that the middle distillates obtained from crude oils of petroleum origin by distillation such as diesel or heating oil contain different amounts of n-alkanes or n-paraffins according to their origin. These n-alkyl, iso-alkyl or n-alkenyl substituted compounds tend to crystallize by lowering the temperature, clogging pipes, lines, pumps and filters, for example in motor vehicle fuel systems. In winter or under conditions of use of fuels or fuels below 0 ° C, the phenomenon of crystallization can lead to the decrease of the flow properties of fuels and, consequently, difficulties during their transport, storage and / or their use. The cold operability of fuels is important, especially for starting cold engines. If the paraffins are crystallized at the bottom of the tank, they can be driven to start in the fuel system and particularly clog the filters and prefilters arranged upstream systems injection pump and injectors. Similarly, for the storage of domestic fuel oils, paraffins precipitate at the bottom of the tank and can be driven and obstruct the pipes upstream of the pump and the boiler supply system (nozzle and filter).

These problems are well known in the field of fuels, and many additives or additive mixtures have been proposed and marketed to reduce the size of the paraffin crystals and / or change their shape and / or prevent them from forming. The smallest crystal size possible is preferred because it minimizes the risk of clogging or filter clogging. The usual flow improvers known as cold flow improvers (CFI) for crude oils and middle distillates are co- and ter-polymers of ethylene and ester (s). vinyl (s) and / or acrylic (s), alone or in admixture. Cold Flow Additives (CFI) for lowering the Filtration Limit Temperature (TLF) and pour point (PE) inhibit crystal growth at low temperatures by promoting dispersion of paraffin crystals; these are, for example, polymers of ethylene and vinyl acetate and / or vinyl propionate (EVA or EVP), also known as TLF additives (Temperature Limit of Filtration). This type of additive, widely known by those skilled in the art, is systematically added to conventional distillates of conventional type at the refinery outlet. These additive distillates are used as fuel for diesel engines or as heating fuel. Additional quantities of these additives can be added to the fuels sold at petrol stations, in particular to meet the specifications of Grand froid.

In order to improve both the TLF and the pour point of the distillates, additives with the function of acting in combination with these additives on the pour point of the distillates are added to these TLF additives. The prior art extensively describes such combinations of additives improving both the Temperature Limit of Filtration (TLF) and the flow temperature at low temperatures of the hydrocarbon distillates of conventional type.

By way of example, mention may be made of US Pat. No. 3,254,527, which describes a distillate distillation distillate of between 177 and 400 ° C. containing an additive consisting of from 90 to 10% by weight of an ethylene copolymer comprising from 10 to 30% of vinyl acetate units of molar mass by weight of between 1000 and 3000 g. mol ^"1 and from 10 to 90 wt.% of a lauryl polyacrylate and / or a lauryl polymethacrylate of molar mass by weight ranging from 760 to 100,000 g. mol ^{" 1} . By way of example, mention may also be made of JP 2003 286495 A, which describes the use as cold-flow additive of copolymers obtained by copolymerization of ethylene and of a monomer comprising an aromatic ring. By way of example of combination, one can also cite the document EP0857776 in which the alkylphenol-aldehyde resins resulting from the condensation of alkylphenol and aldehyde have been proposed in association with copolymers or terpolymers ethylene / vinyl ester, to improve the fluidity of mineral oils. The document FR2903418 describes in particular the use of a combination of a polyacrylate or polymethacrylate with a cold-cooling additive (CFI) of the EVA or EVP type, to reveal the effectiveness of the CFI additives by amplifying their effect on the TLF.

In addition to improving the flow of the oil and the distillate, another purpose of the flow enhancement additives is to ensure the dispersion of the paraffin crystals, so as to retard or prevent the sedimentation of the crystals of the crystals. paraffins and thus the formation of a paraffin-rich layer in the bottom of containers, tanks or storage tanks; these paraffin-dispersing additives are referred to as anti-settling additives or WASA (acronym for Wax Anti-Settling Additive).

Modified alkylphenol aldehyde resins have been described in FR2969620 as an anti-sedimentation additive in combination with a TLF additive.

Due to the diversification of fuel or fuel sources, there is still a need to find new additives to improve the properties of low-temperature fuels also called cold-holding properties, including their flow properties during their production. storage and / or their use at low temperatures. This requirement is particularly important for fuels comprising one or more n-alkyl, iso-alkyl or n-alkenyl substituted compounds having a tendency to crystallize in said fuels when stored and / or used at low temperatures. . Thus, the object of the present invention is to provide novel additives and concentrates containing them which can advantageously be used as additives to improve cold-holding properties, in particular the cold-flow properties of these fuels, during their storage and / or their use at low temperature, typically below 0 ° C.

The object of the present invention is furthermore to propose new additives and concentrates containing them acting both on the TLF and retarding and / or preventing the sedimentation of the crystals of n-alkyl, isoalkyl or n-substituted-substituted compounds. alkenyl, in particular paraffins.

Finally, another object of the invention is to provide a fuel or fuel composition having improved cold-holding properties, particularly at temperatures below 0 ° C, preferably below -5 ° C.

OBJECT OF THE INVENTION

The Applicant has discovered that the copolymers mentioned below and additive concentrates containing such copolymers, have remarkable properties as an additive for improving the cold-holding properties of fuels during their storage and / or their use. at low temperature.

SUMMARY OF THE INVENTION

The invention relates to the use of a copolymer as an additive for improving the cold-holding properties of a fuel or a fuel, this copolymer being obtained by copolymerization of at least: (i) an apolar monomer (m _a ) having the following formula I):

G (l)

With

u = 0 or 1

w = 0 or 1 E = -O- or -NH (Z) -, or -O-CO-, or -NH-CO- or -CO-NH-, where Z is H or a C1-C6 alkyl group, with the proviso that when E = -O-CO- E is connected to the vinyl carbon by the oxygen atom,

G represents a group chosen from a C1-C4 alkyl, an aromatic ring, an aralkyl comprising at least one aromatic ring and at least one C1-C34 alkyl group, and

(ii) an α, β-unsaturated polar monomer (m _b ) containing at least one styrene derivative or an alpha-methylstyrene derivative. One of the monomers being polar and the other monomer being apolar, it is understood that the monomers (m _a ) and the monomers (m _b ) are distinct.

According to a preferred embodiment, the polar monomer (m _b ) is chosen from styrene and alpha-methylstyrene derivatives whose aromatic nucleus is substituted by at least one R group or at least one C 1 to C hydrocarbon chain. C- | ₂ , linear or branched, preferably acyclic, substituted by at least one R group, said R group being chosen from:

groups comprising from 1 to 40 atoms chosen independently from C, N, and optionally O, and comprising at least one primary, secondary, tertiary or quaternary ammonium amine function,

the hydroxyl group,

- a group -OQ,

- a group - (OC _y H _2y O) rH,

- a group - (OC _y H _2y O) rQ,

a group -0- (CO) -Q, and

a group - (CO) -OQ,

y is an integer from 2 to 8, f is an integer from 1 to 10 and Q is selected from C 1 to C ₂₄ alkyl chains. According to a still more preferred embodiment, the group R is chosen from groups having a primary, secondary or tertiary amine function.

According to an advantageous embodiment, the group R is chosen from the group consisting of: -NH ₂ ; groups having at least one amine, imine, amidine, guanidine, aminoguanidine or biguanidine function; heterocyclic groups having from 3 to 34 atoms and at least one nitrogen atom. According to another preferred embodiment, the polar monomer (m _b ) is chosen from styrene and alpha-methylstyrene derivatives, the aromatic nucleus of which is substituted by at least one linear or branched C 1 -C 12 hydrocarbon-based chain, preferably acyclic, preferably selected from alkyl groups, said chain being substituted by one or more groups containing a quaternary ammonium.

According to an advantageous embodiment, the group R is chosen from groups having at least one quaternary ammonium function, preferably chosen from tertiary quaternary ammoniums.

According to an even more advantageous embodiment, the quaternary ammonium function is chosen from quaternary ammoniums of iminium, amidinium, formamidinium, guanidinium and biguanidinium.

According to another advantageous embodiment, the quaternary ammonium function is chosen from quaternary ammoniums of pyrrolinium, pyridinium, imidazolium, triazolium, triazinium, oxazolium and isoxazolium. According to yet another advantageous embodiment, the group R is chosen from trialkylammonium groups, preferably the polar monomer (m _b ) is chosen from the isomers of (vinylbenzyl) trialkylammoniums, alone or as a mixture.

According to another preferred embodiment, the polar monomer (m _b ) is chosen from monomers derived from styrene or alpha-methylstyrene whose aromatic nucleus is substituted by at least one -O- (CO) -Q group, Q being selected from C1 to C4 alkyls

According to another preferred embodiment, the polar monomer (m _b ) is chosen from monomers derived from styrene or alpha-methylstyrene whose aromatic nucleus is substituted by at least one hydroxyl group or by a C 1 to C 3 hydrocarbon chain. C12, linear or branched, preferably acyclic, substituted by at least one hydroxyl group. According to a preferred embodiment, the group E of the apolar monomer (m _a ) is chosen from -O-, -NH (Z) - with Z represents H or a C 1 -C 6 alkyl group, and -O- Where E is connected to the vinyl carbon by the oxygen atom.

According to a preferred embodiment, in formula (I), w is equal to 0.

According to a preferred embodiment, in formula (I), the group G is a C4-C30 alkyl.

According to another preferred embodiment in formula (I), the group G is an aralkyl comprising at least one aromatic ring and at least one C4-30 alkyl group.

According to a preferred embodiment, the copolymer is a block or random copolymer, preferably a block copolymer.

Advantageously, the copolymer is a block copolymer obtained by block copolymerization and controlled.

Even more preferably, the copolymer is a diblock copolymer.

According to a preferred embodiment, the block copolymer is represented by the following formula (III) or (IV):

(III)

in which

m = 0 or 1,

n is an integer ranging from 2 to 50, preferably from 3 to 20,

p is an integer ranging from 2 to 50, preferably from 3 to 20,

R ₀ is chosen from hydrogen or the methyl group, preferably R ₀ is H,

Ri is chosen from hydrocarbon chains, preferably alkyl groups, cyclic or acyclic, saturated or unsaturated, linear or branched Ci to C32, preferably C ₄ -C _24, more preferably a Cio to C ₂₄ and groups resulting from a reversible addition-fragmentation chain transfer (RAFT) radical transfer agent, it being understood that if R1 is a group derived from a transfer agent then m = 0, R ₂ represents the group - (E) _u -G,

R ₃ is a substituent in the ortho, meta or para position on the aromatic ring, preferably in the para position, chosen from the group consisting of at least one R group or at least one linear or branched C ₁ -C ₁₂ hydrocarbon-based chain; , preferably acyclic, substituted by at least one R group, said R group being chosen from:

a group comprising from 1 to 40 atoms chosen independently from C, N, and optionally O, and comprising at least one primary, secondary, tertiary or quaternary ammonium amine function,

a hydroxyl group or -CH ₂ OH,

C 1 to C ₂₄ , preferably C 1 to C ₁₂ , alkoxy groups _,

- polyalkoxy groups: - (OC _y H _2y O) rH where y is an integer from 2 to 8, preferably 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 1 to 10, preferably of

2 to 8, more preferably 2 to 4,

- polyalkoxy groups: - (OC _y H _2y O) RR8 where y is an integer from 2 to 8, preferably 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 1 to 10, preferably from 2 to 8, more preferably from 2 to 4, and R ₈ represents a C 1 to C ₂₄ alkyl, preferably C1 to C12 _,

the groups -OCOR ₉ and -COOR ₉ in which R ₉ is chosen from C 1 to C ₂₄ , preferably C 1 to C 12 _, more preferably C 1 to C ₆ , linear or branched, preferably acyclic, and

R ₄ is selected from the group consisting of:

- hydrogen;

- OH ;

halogens, preferably bromine; and,

- hydrocarbon chains, cyclic or acyclic, saturated or unsaturated, linear or branched Ci to C32, preferably C, to C _24, more preferably Ci-C1 _0, preferably alkyl groups, said chains being optionally substituted by one or more groups containing at least one heteroatom selected from N and O, R ₅ and R ₆ are identical or different and independently selected from the group consisting of hydrogen and alkyl groups C1 to Ci _0, preferably -C C ₄ , linear or branched, more preferably acyclic, even more preferentially the methyl group,

R ₇ is selected from hydrogen or methyl, preferably R ₇ is H.

The invention also relates to the use of a copolymer as defined above as an anti-sedimentation additive, in particular for retarding and / or preventing the sedimentation of crystals of n-alkyl, isoalkyl or n-substituted-substituted compounds. alkenyl during storage and / or use at low temperatures.

The invention further relates to the use of a copolymer as defined above as an additive for improving the cold-holding properties of a fuel or fuel from one or more sources selected from the group consisting of mineral, animal, vegetable and synthetic sources, said copolymer being used with at least one cold-cooling additive (CFI) improving the low-temperature flow properties of said fuel or fuel during its storage and / or its use at low temperature .

Preferably, said fuel or fuel comprises one or more n-alkyl, iso-alkyl or n-alkenyl substituted compounds having a tendency to crystallize in said fuel or a fuel during storage and / or use at low temperature. . According to a preferred embodiment, the use is intended to amplify the fluidifying effect of the cold-flow-making additive (CFI) by improving the Filtration Limit Temperature (TLF) according to standard NF EN 1 16 of said fuel or fuel. The invention also relates to an additive concentrate comprising a copolymer as defined above and comprising at least one cold-cooling additive (CFI), preferably chosen from ethylene and ester (s) copolymers and terpolymers. vinyl (s) and / or acrylic (s), alone or in admixture. According to a preferred embodiment, the additive concentrate further comprises at least one organic liquid, said organic liquid being inert with respect to the copolymer and miscible with fuels or fuels derived from one or more sources chosen from group consisting of mineral, animal, vegetable and synthetic sources. The invention also relates to the use of a concentrate as defined above, for retarding or preventing the sedimentation of the crystals of the n-alkyl, isoalkyl or n-alkenyl substituted compounds of the fuel or fuel during its storage. and / or its use at low temperature. The invention also relates to the use of a concentrate as defined above to improve the fluidizing (flow) effect by improving the filterability limit temperature (TLF) of the fuel or fuel.

The invention also relates to the use of a concentrate as defined above, in which the fuel or fuel is chosen from diesel fuel, bio-gas oils, gas oil and bio-diesel fuel mixtures of type B _x and fuel oils, preferably domestic fuel oils (FOD).

The invention further relates to a fuel or fuel composition comprising: (1) a fuel or fuel from one or more sources selected from the group consisting of mineral, animal, plant and synthetic sources,

(2) the copolymer as defined above, and,

(3) cold-improving cold-forming additive (CFI), preferably chosen from copolymers and terpolymers of ethylene and of vinyl ester (s) and / or acrylic (s) (EVA and or EVP), alone or as a mixture, said additive being present in the fuel or fuel composition in an amount sufficient to improve the behavior low temperature flow of the fuel or fuel (1) during storage and / or use at a low temperature.

According to a preferred embodiment, in the fuel or fuel composition: (1) the fuel or fuel is derived from one or more sources selected from the group consisting of mineral, animal, plant and synthetic sources, includes one or a plurality of n-alkyl, isoalkyl or n-alkenyl substituted compounds having a tendency to crystallize in said fuel or fuel during storage and / or use at a low temperature,

(2) the copolymer as defined above is present in the composition in an amount sufficient to retard or prevent the sedimentation of the crystals of said n-alkyl, iso-alkyl or n-alkenyl substituted compounds, during storage and / or the low temperature use of said fuel or fuel (1). According to a preferred embodiment, the composition contains at least 10 ppm, preferably between 10 and 5000 ppm of the copolymer and at least 10 ppm, preferably between 10 and 5000 ppm of the cold-flow additive.

According to a preferred embodiment, in the composition, the fuel or fuel is selected from gas oils, bio-diesel, blends of diesel and bio-diesel type B _x and fuel oils, more preferably from gas oils, biodiesel, diesel and bio-diesel fuel mixtures type B _x .

DETAILED DESCRIPTION

Other advantages and features will emerge more clearly from the following description. The particular embodiments of the invention are given by way of non-limiting examples. The Applicant has discovered that the copolymers mentioned below and the additive concentrates containing such copolymers can be used to improve the cold-holding properties of fuels comprising one or more n-alkyl, isopropyl-substituted compounds. alkyl or n-alkenyl having a tendency to crystallize in said fuels during storage and / or use at low temperature. The Applicant has also discovered that the copolymers mentioned below and the additive concentrates containing such copolymers can be used as an anti-settling additive, also called WASA or "Wax Anti-Settling Additive", to retard and / or prevent sedimentation of crystals of n-alkyl, isoalkyl or n-alkenyl substituted compounds during storage and / or use at low temperatures.

The Applicant has also discovered that the copolymers mentioned below and the additive concentrates containing such copolymers can be used as an additive improving the filterability limit temperature (TLF) for fuels, by combining them with an improvement additive. cold flow improver ("Cold Flow Improvers" or CFI) during storage and / or use at low temperatures.

The copolymer used as an additive improving the cold properties of a fuel or a fuel is obtained by copolymerization of at least one apolar (m _a ) and at least one styrenic monomer (m _b ).

According to one embodiment, the copolymer is chosen from block copolymers and random copolymers.

According to a preferred embodiment, the copolymer is a block copolymer.

The copolymer can be obtained by copolymerizing at least one apolar monomer (m _a ), and at least one polar monomer (m _b )

The olaire monomer (m _a ) _has the following formula (I):

G (l)

With

u = 0 or 1

w = 0 or 1 Advantageously, the monomer (m _a ) is such that w = 0.

The group E of the apolar monomer (m _a ) is chosen from

- E = -O-,

- E = -NH (Z) - with Z represents H or a linear or branched, cyclic or acyclic, preferably acyclic, C 1 -C 6 alkyl group,

E = -O-CO- being understood that E is then connected to the vinyl carbon by the oxygen atom,

E = -NH-CO-, and

- E = -CO-NH-.

According to a first variant, the apolar monomer (m _a ) is chosen from those verifying u = 0. Preferably, and according to this first variant, the copolymer is a block copolymer.

According to another variant, the monomer (m _a ) is chosen from those verifying u = 1.

According to a preferred variant, the apolar monomer (m _a ) is chosen from those verifying: u = 1, and the group E is chosen from:

- E = -O-,

E = -NH (Z) - with Z represents H or a linear or branched, cyclic or acyclic, preferably acylic, C 1 -C 6 alkyl group, preferably CH ₃ , and

E = -O-CO- where E is connected to the vinyl carbon by the oxygen atom. According to a still more preferred variant, the apolar monomer (m _a ) is chosen from those verifying: u = 1, and the group E is chosen from:

o E = -O-, and

o E = -O-CO- where E is connected to the vinyl carbon by the oxygen atom. The group (G) of the apolar monomer (m _a ) may be a C 1 -C 3 alkyl, preferably a C 4 -C 30 alkyl radical, more preferably a C 6 -C 24, still more preferably a C 8 -C 18 alkyl radical. The alkyl radical is a linear or branched radical, cyclic or acyclic, preferably acyclic. This alkyl radical can comprise a linear or branched part and a cyclic part.

The group (G) of the apolar monomer (m _a ) is advantageously an acyclic alkyl in C1-C34, preferably an alkyl radical C4-C30, more preferably C6-C24, still more preferably C8-C18, linear or branched, preferably linear.

Mention may be made, without limitation, of alkyl groups such as octyl, decyl, dodecyl, ethyl-2-hexyl, isooctyl, isodecyl and isododecyl.

Among the alkyl vinyl ester monomers, mention may be made, for example, of vinyl octanoate, vinyl decanoate, vinyl dodecanoate, vinyl tetradecanoate, vinyl hexadecanoate, vinyl octodecanoate and docosanoate. vinyl, 2-ethylhexanoate vinyl.

The group (G) of the apolar monomer (m _a ) may also be an aromatic ring, preferably a phenyl or aryl group. Among the aromatic groups, there may be mentioned, without limitation, the phenyl or naphthyl group, preferably the phenyl group.

The group (G) of the apolar monomer (m _a ) may, according to another preferred variant, be an aralkyl comprising at least one aromatic ring and at least one C 1 -C 34 alkyl group. Preferably, according to this variant, the group (G) is an aralkyl comprising at least one aromatic ring and one or more C4-C30 alkyl groups, advantageously C6-C24, still more preferably C8-C18.

The aromatic ring may be mono-substituted or substituted on a number of its carbon atoms. Preferably, the aromatic ring is monosubstituted.

The C1-C34 alkyl group may be in the ortho, meta or para position on the aromatic ring, preferably in para.

The alkyl radical is a linear or branched radical, cyclic or acyclic, preferably acyclic. The alkyl radical is preferably an acyclic radical, linear or branched, preferably linear.

The aromatic ring may be directly attached to the E group or the vinyl carbon but may also be connected to it via an alkyl substituent. By way of example of group (G), mention may be made of a benzyl group substituted in para with a C 4 -C 30 alkyl group.

Preferably, according to this variant, the group (G) of the apolar monomer (m _a ) is an aralkyl comprising at least one aromatic ring and at least one C 4 -C 30 alkyl group, advantageously C 6 -C 24, still more preferably C 8 at C18.

The polar monomer (m _b ) is chosen from styrene and alpha-methylstyre derivatives whose aromatic ring is substituted with at least one R group or with at least one C 1 -C 12 and preferably C 1 -C 8 hydrocarbon-based chain. ₄ , linear or branched, preferably acyclic, advantageously -CH ₂ -, substituted by at least one R group.

By hydrocarbon chain is meant a chain consisting exclusively of carbon and hydrogen atoms, said chain being linear or branched, cyclic, polycyclic or acyclic, saturated or unsaturated, and optionally aromatic or polyaromatic. A hydrocarbon chain may comprise a linear or branched part and a cyclic part. It may include an aromatic part and an aromatic part.

The substitution on the aromatic ring of the styrenic group is ortho, meta or para, preferably para.

Preferably, the aromatic ring of the styrenic group is substituted by a single substituent. According to a first variant, the group R is chosen from:

the hydroxyl group,

- alkoxy groups: -OQ, Q is an alkyl to C _24,

- polyalkoxy groups: - (OC _y H _2y O) rH where y is an integer ranging from 2 to 8, and f is an integer ranging from 1 to 10,

- carboxylates or alkyl esters: - (CO) -OQ, where Q represents an alkyl to C _24,

- alkyl carboxylates or alkyl esters: -0- (CO) -Q, Q is an alkyl to C _24.

According to the first variant, the group R is preferably chosen from:

the hydroxyl group,

- alkoxy groups: -OQ, Q is an alkyl to C _2,

- polyalkoxy groups: - (OC _y H _2y O) rH where y is an integer ranging from 2 to 4, most preferably from 2 to 3 and f is an integer ranging from 2 to 8, more preferably from 2 to 4,

- polyalkoxy groups: - (OC _y H _2y O) rQ where y is an integer preferably ranging from 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 2 to 8, more preferably from 2 to 4 , Q is an alkyl to C _2,

the carboxylates or alkyl esters: - (CO) -OQ, Q representing a Ci-Ci ₂ alkyl,

the alkyl carboxylates or alkyl esters: -O- (CO) -Q, Q representing a C1-C12 alkyl.

Even more preferably, R is selected from alkyl carboxylates: -0- (CO) -Q, Q is an alkyl to C _24, preferably Ci-Ci _2.

According to a preferred embodiment, the group R is the acetoxy group.

According to another preferred embodiment, the group R is the hydroxyl group. According to a preferred embodiment, the polar monomer (m _b ) is chosen from monomers derived from styrene or alpha-methylstyrene whose aromatic ring is substituted with a -CH ₂ -R group.

According to this preferred embodiment, the group R is preferably chosen from: - the hydroxyl group and,

the alkyl carboxylates: -O- (CO) -Q, Q representing a C 1 to C ₂₄ alkyl, preferably C 1 to C _2, more preferably C 1 to C ₈ , still more preferably C 1 to C ₄ , example the acetoxy group. According to this preferred embodiment, the R group is preferably the hydroxyl group.

The polar monomer (m _b ) may, in particular, be chosen from monomers derived from styrene or alpha-methylstyrene, the aromatic ring of which is substituted by at least one alkyl carboxylate group -O- (CO) -Q, Q is an alkyl to C _24, preferably Ci to Ci _2, most preferably C, to C _8, more preferably to C _4, for example the acetoxy group.

The alkyl carboxylate group -O- (CO) -Q may be in the ortho, meta or para position on the aromatic ring, preferably in the para position. According to one particular embodiment, the polar monomer (m _b ) is chosen from monomers derived from styrene or alpha-methylstyrene whose aromatic nucleus is substituted in the ortho, meta or para position by at least one hydroxyl group or by a linear or branched, preferably acyclic, C 1 to C ₁₂ , preferably C 1 to C ₄ , hydrocarbon chain substituted by at least one hydroxyl group.

According to a second variant, the group R is chosen from groups having at least one primary, secondary or tertiary amine function. In particular, the group R is chosen from the group consisting of: -NH ₂ ; groups having at least one amine, imine, amidine, guanidine, aminoguanidine or biguanidine function; heterocyclic groups having from 3 to 34 atoms and at least one nitrogen atom.

Advantageously, according to this variant, the group R is connected to the aromatic group or the hydrocarbon chain, preferably via a nitrogen atom present in the group R,

According to the second preferred variant, advantageously, the group R is chosen from the group consisting of:

groups having at least one amine, imine, amidine, guanidine, aminoguanidine or biguanidine function, such as alkyl-amines, polyalkylene polyamines, polyalkylenimines, alkylimines, alkylamidines, alkylguanidines and alkyl-biguanidines, alkyl substituent preferably having 1 to 34 carbon atoms, preferably 1 to 12 and being linear or branched, cyclic or acyclic.

monocyclic or polycyclic heterocyclic groups having from 3 to 34 atoms, preferably from 5 to 12 atoms, more preferably from 6 to 10 atoms, and at least one nitrogen atom, it being understood that the polycyclic heterocyclic groups have, if appropriate , merged cycles. The number of atoms includes hetero atoms. By fused rings are meant rings having at least two atoms in common. The heterocyclic groups may further comprise an oxygen atom and / or a carbonyl group and / or one or more unsaturations.

By way of example of heterocyclic R group, mention may be made of the following radicals: triazole, aminotriazole, pyrrolidone, piperidine imidazole, morpholine, isoxazole, oxazole and indole, said radical preferably being linked to the hydrocarbon chain or to the aryl group by an atom nitrogen. Advantageously, the group R is chosen from the group consisting of:

- groupings:

• amine: -NH ₂ ; -NHR ', -NR'R ";

Imine: -HC = NH; -HC = NR '; -N = CH ₂ , -N = CR'H; -N = CR'R "

Amidine: - (C = NH) -NH ₂ ; - (C = NH) -NR'H; - (C = NH) -NR'R "- (C = NR ') - NH ₂ ;

- (C = NR ') - NR "H; - (C = NR') - NR" R "'; -N = CH (NH ₂ ); -N = CR' (NH ₂ );

-N = CH (NR'H); -N = CR '(NR'H); -N = CH (NR'R "); -N = CR '(NR" R "');

Guanidine: -NH- (C = NH) -NH ₂ ; -NH- (C = NH) -NHR '; -N = C (NH ₂ ) ₂ ;

-N = C (NR'H) ₂ ; -N = C (NR'R ") ₂ ; -N = C (NR'H) (NR" H),

Aminoguanidine: -NH- (C = NH) -NH-NH ₂ ; -NH- (C = NH) -NH-NHR ';

-N = C (NH ₂ ) (NH-NH ₂ ); -N = C (NR'H) (NH-NH ₂ ); -N = C (NR'H) (NR'-NH ₂ );

-N = C (NR'R ") (NH-NH ₂₎ -N = C (NR'R") (NR'-NH _2),

Biguanidine: -NH- (C = NH) -NH- (C = NH) -NH ₂ ; -NH- (C = NH) -NH- (C = NH) -NHR '

-N = C (NH ₂ ) -NH- (C = NH) -NH ₂ ; -N = C (NH ₂₎ -NH- (C = NR ') - NH _2;

-N = C (NH ₂ ) -NH- (C = NH) -NR'H; -N = C (NH ₂ ) -NH- (C = NR ') - NR "H _;

-N = C (NH ₂ ) -NH- (C = NH) -NR'R "; -N = C (NH ₂ ) -NH- (C = NR ') - NR" R "';

-N = C (NR'H) -NH- (C = NH) -NH ₂ ; -N = C (NR'H) -NH- (C = NR ") - NH ₂ ;

-N = C (NR'H) -NH- (C = NH) -NR "H; -N = C (NR'H) -NH- (C = NR") - NR "'H _;

-N = C (NR'H) -NH- (C = NH) -NR "R"'; -N = C (NR'H) -NH- (C = NR ") - NR" R ""_; -N = C (NR'R ") - NH- (C = NH) -NH _2; -N = C (NR'R") - NH- (C = NR "') - NH _2;

-N = C (NR'R ") - NH- (C = NH) -NR"'H; -N = C (NR'R ") - NH- (C = NR"') - NR "" H _; -N = C (NR'R ") - NH- (C = NH) -NR" R ""; -N = C (NR'R ") - NH- (C = NR"') - NR "" R ""'

the groups -NH- (R _a -NH) _k -H; -NH- (R _a -NH) _k -R '; and

R ', R ", R'", R '"andR""are independently from each other an alkyl group HC ₃ 6, preferably C ₂ Ci, optionally comprising one or more functions NH ₂ and one or more -NH- bridges;

R _a represents a C ₁ -C ₆ alkyl group, preferably C ₂ -C ₄ alkyl, k represents an integer ranging from 1 to 20, preferably from 2 to 12.

Examples of R groups having an amino function include polyamines and polyalkylene polyamines, for example ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine.

According to one variant, the group R is chosen from groups having at least one quaternary ammonium function obtained by quaternization of the primary amines, secondary or tertiary as described above, according to any known method.

The group R may, in particular, be chosen from groups having at least one quaternary ammonium function obtained by quaternization of at least one amine, imine, amidine, guanidine, aminoguanidine or biguanidine function; heterocyclic groups having from 3 to 34 atoms and at least one nitrogen atom.

Advantageously, the group R is chosen from groups having at least one quaternary ammonium function obtained by quaternization of the tertiary amines.

According to a particular embodiment, the quaternary ammonium is selected from the quaternary ammonium of iminium, amidinium, formamidinium, guanidinium and biguanidinium. According to another particular embodiment, the group R is chosen from groups having at least one quaternary ammonium functional group chosen from heterocyclic groups having from 3 to 34 atoms and at least one nitrogen atom, preferably from quaternary ammoniums of pyrrolinium. , pyridinium, imidazolium, triazolium, triazinium, oxazolium and isoxazolium.

According to a particular embodiment, the group R is chosen from quaternary ammoniums, preferably comprising at least one C ₁ to C ₄ , preferably C 1 to C ₄ , hydrocarbon chain, linear or branched, cyclic or acyclic, preferably acyclic, said chain optionally comprising one or more oxygen atoms in the form of an ether function or in substitution, preferably in substitution. The hydrocarbon chain may, for example, be an alkyl chain substituted with a hydroxyl group, this type of quaternary ammonium salt being obtainable by reaction of a tertiary amine with an epoxide according to any known method. Advantageously, the group R is chosen from trialkylammonium groups. The alkyl substituents of trialkylammonium are preferably selected from alkyl groups having from 1 to 10 carbon atoms, preferably from 1 to 4 carbon atoms, and being linear or branched, cyclic or acyclic, preferably acyclic. Alternatively, the R group is selected from quaternary ammonium substituted with at least one hydrocarbon chain, preferably alkyl, Ci-Ci _0, still more preferably C ₁ -C ₄ linear or branched, cyclic or acyclic, preferably acyclic, comprising one or more hydroxyl groups.

According to a particular embodiment, the polar monomer (m _b ) is represented by the following formula (II):

(he)

In which :

t = 0, 1

g = 0, 1

X represents a C 1 to C ₁₂ , preferably C 1 to C ₄ , hydrocarbon chain, more preferably the -CH ₂ group,

R is as described above _.

The monomers derived from styrene (t = 0) will generally be preferred in formula (II) over monomers derived from alpha-methylstyrene (t = 1).

The monomer derived from styrene (m _b ) is, for example, selected from vinyl phenols and (vinyl phenyl) methanols in the ortho, meta and para position, preferably para. The monomer derived from styrene (m _b ) is, for example, chosen from acetoxystyrene in the ortho, meta and para position, preferably para.

According to another preferred embodiment, the monomer (m _b ) is chosen from the (vinylbenzyl) trialkylammonium isomers in the ortho, meta or para position, preferably in para, alone or as a mixture.

The copolymer may be a block copolymer, a random copolymer or any other form of copolymer.

According to a particular embodiment, the block copolymer comprises at least a block A consisting of a chain of structural units derived from one or more apolar monomers selected from apolar monomers (m _a ) of formula (I) and a block B consisting of a chain of structural units derived from one or more polar monomers selected from polar monomers (m _b ),

It being understood that block A is derived solely from apolar monomers (m _a ) and that block B contains only polar blocks (m _b ).

According to a particular preferred embodiment, the block copolymer comprises at least: a block A consisting of a chain of structural units derived from an apolar monomer chosen from apolar monomers (m _a ) of formula (I) and,

a B block consisting of a chain of structural units derived from a polar monomer selected from polar monomers (m _b).

According to a particular preferred embodiment, the block copolymer is represented by one of the following formulas (III) and (IV):

(IV) in which

m = 0 or 1,

n is an integer ranging from 2 to 50, preferably from 3 to 20,

p is an integer ranging from 2 to 50, preferably from 3 to 20,

R ₀ is chosen from hydrogen or the methyl group, preferably R ₀ is H,

Ri is chosen from hydrocarbon chains, preferably alkyl groups, cyclic or acyclic, saturated or unsaturated, linear or branched Ci to C32, preferably C ₄ -C _24, more preferably a Cio to C ₂₄ and groups resulting from a reversible addition-fragmentation chain transfer agent (RAFT), a reversible additive-fragmentation chain transfer agent

Transfer), it being understood that if T is a grouping from a transfer agent then m = 0.

RAFT transfer agents are well known to those skilled in the art. A wide variety of RAFT transfer agents are available or quite easily synthesizable. By way of example, mention may be made of thiocarbonylthio, dithiocarbonate, xanthate, dithiocarbamate and trithiocarbonate transfer agents, for example S, S-bis (α, α'-dimethyl-α-acetic acid) trithiocarbonate (BDMAT ) or 2-cyano-2-propylbenzodithioate R ₂ represents the group - (E) _u -G

The groups E, G, and u, have the same definition as that given above in the formula (I).

R ₃ is a substituent in the ortho, meta or para position on the aromatic ring, preferably in the para position, chosen from the group consisting of at least one R group or at least one linear or branched C 1 -C 12 hydrocarbon-based chain, preferably acyclic, substituted by at least one group R, said group R being chosen from:

a hydroxyl group or -CH ₂ OH,

- alkoxy groups to C _24, preferably Ci-Ci ₂

. polyalkoxy groups: - (OC _y H _2y O) rH where y is an integer from 2 to 8, preferably 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 1 to 10, preferably 2 to 8, more preferably 2 to 4,

. polyalkoxy groups: - (OC _y H _2y O) RR8 where y is an integer from 2 to 8 preferably from 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 1 to 10, preferably from 2 to 8, more preferably from 2 to 4, and R ₈ represents a C ₁ -C 4 alkyl, preferably Ci-Ci ₂

the groups -OCOR ₉ and -COOR ₉ in which R ₉ is chosen from C 1 to C ₂₄ , preferably C 1 to C 12, more preferably C 1 to C ₆ alkyl groups, which are linear or branched, preferably acyclic,

groups comprising from 1 to 40 atoms chosen from C, N, and optionally O, and comprising at least one primary, secondary, tertiary, or quaternary ammonium amine function, in particular represented by the following formula (V):

-CH ₂ -N ⁺ (R ₁₀ ) (R 1) (R ₁ ) Z ^- (V)

in which

Z ^" is chosen from hydroxide ions, halides and organic anions, in particular the acetate ion,

and,

Rio, Ru and R ₁₂ are, identical or different, and chosen independently from C 1 to C ₁₀ , preferably C 1 to C ₄ , alkyl groups, linear or branched, cyclic or acyclic, preferably acyclic,

the groups of formula (VI) below:

-CH ₂ -R ₁₃ (VI)

in which

R-13 is chosen from groups comprising from 1 to 40 atoms chosen from C, N, and optionally O, and comprising at least one primary, secondary or tertiary amine function,

and,

R ₄ is selected from the group consisting of:

- hydrogen;

- OH

halogens, preferably bromine; and,

linear or branched, C 1 to C ₃₂ , preferably C 1 to C ₂₄ , hydrocarbon chains, cyclic or acyclic, saturated or unsaturated,

more preferably C ₁ -C ₁₀ , preferably alkyl groups, said chains being optionally substituted with one or more groups containing at least one heteroatom selected from N and O,

R ₅ and R ₆ are identical or different and independently selected from the group consisting of hydrogen and C 1 to C ₁₀ , preferably C 1 to C ₄ , alkyl groups, linear or branched, more preferably acyclic, even more preferably methyl group,

R ₇ is selected from hydrogen or methyl group, preferably R ₇ is H.

R 1 is preferably chosen from linear or branched, C ₁ to C 32, preferably C ₄ to C _24, more preferably C ₁₀ alkyl, cyclic or acyclic groups;

R ₃ is, according to a first preferred variant, a substituent in the ortho, meta or para position on the aromatic ring, preferably in the para position, chosen from the groups - OCOR ₉ where R ₉ is as described above.

According to another preferred variant, at least one of the groups R ₃ , R ₄ and R ₁₃ is a group having at least one primary, secondary or tertiary amine function chosen independently from the group consisting of:

monocyclic or polycyclic heterocyclic groups having from 3 to 34 atoms, preferably from 5 to 12 atoms, more preferably from 6 to 10 atoms, and at least one nitrogen atom, it being understood that the polycyclic heterocyclic groups have, if appropriate , merged cycles. The number of atoms includes hetero atoms. By fused rings are meant rings having at least two atoms in common. The heterocyclic groups may further comprise an oxygen atom and / or a carbonyl group and / or one or more unsaturations. By way of example of a heterocyclic group, mention may be made of the following radicals: triazole, aminotriazole, pyrrolidone, piperidine imidazole, morpholine, isoxazole, oxazole and indole, said radical preferably being linked by a nitrogen atom.

Advantageously, according to this variant, at least one of the groups R ₃ , R ₄ and R ₁₃ is chosen from the group consisting of:

- groupings:

• amine: -NH ₂ ; -NHR ', -NR'R ";

Imine: -HC = NH; -HC = NR '; -N = CH ₂ , -N = CR'H; -N = CR'R "

Amidine: - (C = NH) -NH ₂ ; - (C = NH) -NR'H; - (C = NH) -NR'R "- (C = NR ') - NH ₂ ; - (C = NR ') - NR "H; - (C = NR') - NR" R "'; -N = CH (NH ₂ ); -N = CR' (NH ₂ );

-N = CH (NR'H); -N = CR '(NR'H); -N = CH (NR'R "); -N = CR '(NR" R "');

^• guanidine: -NH- (C = NH) -NH _2; -NH- (C = NH) -NHR '; -N = C (NH ₂ ) ₂ ; -N = C (NR'H) ₂ ;

-N = C (NR'R ") ₂ ; -N = C (NR'H) (NR" H),

Aminoguanidine: -NH- (C = NH) -NH-NH ₂ ; -NH- (C = NH) -NH-NHR ';

-N = C (NR'R ") (NH-NH ₂₎ -N = C (NR'R") (NR'-NH _2),

Biguanidine: -NH- (C = NH) -NH- (C = NH) -NH ₂ ; -NH- (C = NH) -NH- (C = NH) -NHR ';

-N = C (NR'H) -NH- (C = NH) -NH ₂ ; -N = C (NR'H) -NH- (C = NR ") - NH ₂ ;

-N = C (NR'H) -NH- (C = NH) -NR "H; -N = C (NR'H) -NH- (C = NR") - NR "'H _;

-N = C (NR'R ") - NH- (C = NH) -NR"'H; -N = C (NR'R ") - NH- (C = NR"') - NR "" H _;

-N = C (NR'R ") - NH- (C = NH) -NR" R "'; -N = C (NR'R") - NH- (C = NR "') - NR""R""' _,

the groups -NH- (R _a -NH) _k -H; -NH- (R _a -NH) _k -R '; and

R ', R ", R" \ R "" and R "" are independently from each other an alkyl group HC ₃ 6, preferably C ₂ Ci, optionally comprising one or more functions and NH ₂ one or more bridges -NH-;

R _a represents an alkyl group Ci-C _6, preferably C ₂ -C _4, k represents an integer ranging from 1 to 20, preferably 2 to 12.

Examples of groups comprising an amino function include polyamines and polyalkylene polyamines, for example ethylene diamine, diethylene triamine, triethylene tetramine and tetraethylene pentamine. The copolymer may be prepared by any known method of polymerization. The various techniques and polymerization conditions are widely described in the literature and fall within the general knowledge of those skilled in the art.

It is understood that one would not depart from the invention if one obtained the copolymer according to the invention from other monomers different from (m _a ) and (m _b ), insofar as the final copolymer corresponds to that of the invention, that is to say obtained from at least (m _a ) and (m _b ). For example, it would not go beyond the invention, if one obtained the copolymer by copolymerization of monomers different from (m _a ) and (m _b ), followed by post-functionalization. For example, blocks derived from an apolar monomer (m _a ) can be obtained from vinyl alcohol or acrylic acid, respectively by transesterification or amidification reaction.

For example, the poly (vinyl phenol) blocks can be obtained from poly (acetoxystyrene) blocks obtained by copolymerization of acetoxystyrene polar monomers (m _b ), followed by hydrolysis according to any known method.

For example, the poly (styrene alkyl ester block) can be obtained from a poly (vinyl phenol) moiety by esterification reaction.

As an example of post-functionalization, mention may be made of nucleophilic substitution reactions well known to those skilled in the art. Thus, a block copolymer comprising a quaternary ammonium group of formula (V) with Rio, u and R ₁₂ being methyl groups and Z a chlorine, can be obtained from a copolymer of formula (III) or (IV) in which R ₃ is a -CH ₂ Cl group, by reaction with trimethylamine. The chloride counterion may be substituted by treatment of the thus obtained block copolymer in an ion exchange column according to any known method.

The block copolymers can be obtained by sequential polymerization, preferably by sequential and controlled polymerization and, optionally followed by one or more post-functionalizations.

The controlled polymerizations can be radical controlled polymerizations or ionic controlled polymerizations.

The choice of the polymerization process is based on the general knowledge of those skilled in the art as a function of the monomers chosen.

According to a particular embodiment, the block copolymer described above is obtained by sequenced and controlled polymerization. The polymerization is advantageously chosen from controlled radical polymerization; for example, by atom transfer radical polymerization (ATRP in English "Atom Transfer Radical Polymerization"); radical polymerization with nitroxide (NMP). mediated polymerization "); degenerative transfer processes (degenerative transfer processes) such as degenerative iodine transfer polymerization (ITRP-iodine transfer radical polymerization) or radical polymerization by reversible addition-fragmentation chain transfer ( RAFT in English "Reversible Addition-Fragmentation Chain Transfer"; polymerizations derived from ATRP such as polymerizations using initiators for the continuous regeneration of the activator (ICAR -Initiators for continuous activator regeneration) or using electron-regenerated activators regenerated by electron (ARGET) transfer "). Block copolymers can be synthesized by living cationic polymerization. The living cationic polymerization is characterized by a decrease in the reactivity of the cationic propagating species, which makes it possible to suppress the termination and transfer reactions while keeping a sufficient reactivity for the propagation. By way of example, mention may be made of the publication "Macromolecular Engineering by atom transfer radical polymerization", JACS, 136, 6513-6533 (2014) which describes a controlled and sequenced polymerization process for forming block copolymers.

The sequenced and controlled polymerization is typically carried out in a solvent, under an inert atmosphere, at a reaction temperature generally ranging from 0 to 200 ° C, preferably from 50 ° C to 130 ° C. The solvent may be chosen from polar solvents, in particular ethers such as anisole (methoxybenzene) or tetrahydrofuran or apolar solvents, in particular paraffins, cycloparaffins, aromatics and alkylaromatics having from 1 to 19 carbon atoms. carbon, for example, benzene, toluene, cyclohexane, methylcyclohexane, n-butene, n-hexane, n-heptane and the like.

For the Atom Transfer Radical Polymerization (ATRP), the reaction is generally carried out under vacuum in the presence of an initiator, a ligand and a catalyst. By way of example of a ligand, mention may be made of N, N, N ', N ", N" -Pentamethyldiethylenetriamine (PMDETA), 1,1,4,7,10,10-hexamethyltriethylene tetramine (HMTETA), 2,2'-Bipyridine (BPY) and Tris (2-pyridylmethyl) amine (TPMA). As an example of a catalyst, mention may be made of: CuX, CuX ₂ , with X = Cl, Br and ruthenium complexes Ru ²⁺ / Ru ³⁺ . The ATRP polymerization is preferably carried out in a solvent chosen from polar solvents. According to the sequenced and controlled polymerization technique, it can also be envisaged to work under pressure. The numbers of apolar monomer equivalents (m _a ) of block A and of polar monomer (m _b ) of block B reacted during the polymerization reaction are identical or different.

The number of apolar monomer equivalents (m _a ) of block A is preferably from 2 to 50, preferably from 3 to 20.

The number of polar monomer equivalents (m _b ) of block B is preferably from 2 to 50, preferably from 3 to 20. The number of equivalents of apolar monomer (m _a ) of block A is advantageously greater than or equal to that of the polar monomer _(b m) of the block B.

In addition, the molar mass in weight M _w of block A or block B is preferably less than or equal to 15,000 g. mol ^"1 , more preferably less than or equal to 10,000 g. mol. ^{" 1} .

The block copolymer advantageously comprises at least one sequence of AB, ABA or BAB blocks in which said blocks A and B are linked together without the presence of an intermediate block of a different chemical nature. Other blocks may optionally be present in the block copolymer described above insofar as these blocks do not fundamentally change the character of the block copolymer. However, block copolymers containing only blocks A and B will be preferred. Between each block A and B, there may optionally be an intermediate portion resulting from the random polymerization of the polar (m _b ) and apolar (m _a ) monomers, depending on the type of copolymerization chosen and / or the type of initiator or transfer agent.

Advantageously, A and B represent at least 70% by weight, preferably at least 90% by weight, more preferably at least 95% by weight, more preferably at least 99% by weight of the block copolymer. According to a particular embodiment, the block copolymer is a diblock copolymer. According to another particular embodiment, the block copolymer is an alternating block triblock copolymer comprising two blocks A and a block B (ABA) or comprising two blocks B and a block A (BAB).

According to one particular embodiment, the block copolymer also comprises a terminal chain I consisting of a linear or branched, C ₁ to C 32, preferably C ₄ to C ₂₄ , hydrocarbon, cyclic or acyclic, saturated or unsaturated hydrocarbon chain, more preferably preferentially at C1 ₀ to C ₂₄ .

The term "cyclic hydrocarbon chain" means a hydrocarbon chain at least a part of which is cyclic, in particular aromatic. This definition does not exclude hydrocarbon chains comprising both an acyclic and a cyclic moiety.

The terminal chain I may comprise an aromatic hydrocarbon chain, for example a benzene chain and / or a linear or branched, saturated and acyclic hydrocarbon-based chain, in particular an alkyl chain.

The terminal chain I is, preferably, selected from alkyl chains, preferably linear, more preferably alkyl chains of at least 4 carbon atoms, even more preferably of at least 12 carbon atoms.

For the ATRP polymerization, the terminal chain I is located in the terminal position of the block copolymer. It can be introduced into the block copolymer by means of the polymerization initiator. Thus, the terminal chain I may, advantageously, constitute at least a part of the polymerization initiator and is positioned within the polymerization initiator in order to introduce, during the first polymerization initiation step. , the terminal chain I in the terminal position of the block copolymer.

The polymerization initiator is, for example, chosen from free radical initiators used in the ATRP polymerization process. These free radical initiators well known to those skilled in the art are described in particular in the article "Atom Transfer Radical Polymerization: Current Status and Future Prospects, Macromolecules, 45, 4015-4039, 2012 ".

The polymerization initiator is, for example, chosen from alkyl esters of a carboxylic acid substituted by a halide, preferably a bromine in the alpha position, for example ethyl 2-bromopropionate or α-bromoisobutyrate. ethyl chloride, benzyl choride or bromide, ethyl α-bromophenylacetate and chloroethylbenzene. Thus, for example, ethyl 2-bromopropionate may make it possible to introduce into the copolymer the terminal chain I in the form of a C ₂ alkyl chain and benzyl bromide in the form of a benzyl group.

For the RAFT polymerization, the transfer agent can conventionally be removed from the copolymer at the end of the polymerization according to any known method.

According to one variant, the terminal chain I can also be obtained in the copolymer by RAFT polymerization according to the methods described in the article by Moad, G. et al., Australian Journal of Chemistry, 2012, 65, 985-1076. The terminal chain I may, for example, be modified by aminolysis when a transfer agent is used to give a thiol function. By way of example, mention may be made of thiocarbonylthio, dithiocarbonate, xanthate, dithiocarbamate and trithiocarbonate transfer agents, for example S, S-bis (α, α'-dimethyl-α-acetic acid) trithiocarbonate (BDMAT or 2-cyano-2-propyl benzodithioate.

According to a particular embodiment, the block copolymer is a diblock copolymer (also called diblocks). The block copolymer structure may be of the IAB or IBA type, advantageously IAB. The terminal chain I may be directly linked to block A or B according to the structure IAB or IBA respectively, or to be linked via a linking group, for example an ester, amide, amine or ether function. The linking group then forms a bridge between the terminal chain I and the block A or B. According to one particular embodiment, the block copolymer can also be functionalized at the end of the chain according to any known method, in particular by hydrolysis, aminolysis and / or nucleophilic substitution.

By aminolysis is meant any chemical reaction in which a molecule is split into two parts by reaction of a molecule of ammonia or an amine. A general example of aminolysis is to replace a halogen of an alkyl group by reaction with an amine, with elimination of hydrogen halide. The aminolysis can be used, for example, for an ATRP polymerization which produces a copolymer having a terminal halide or for a RAFT polymerization to transform the thio, dithio or trithio bond introduced into the copolymer by the RAFT transfer agent. thiol function.

It is thus possible to introduce a terminal chain I 'by post-functionalization of the block copolymer obtained by sequenced and controlled polymerization of the monomers (m _a ) and (m _b ) described above. The terminal chain I 'advantageously comprises a hydrocarbon chain, linear or branched, cyclic or acyclic, C 1 to C 32, preferably C 1 to C ₂₄ , more preferably C 1 to C ₀ , even more preferably an alkyl group, optionally substituted. by one or more groups containing at least one heteroatom selected from N and O, preferably N.

For ATRP polymerization using a metal halide as a catalyst, this functionalization may, for example, be carried out by treating the copolymer IAB or IBA obtained by ATRP with a primary alkylamine to C ₃₂ or an alcohol to C ₃₂ under conditions soft so as not to modify the functions present on blocks A, B and I.

In formulas (III) and (IV), block A corresponds to the repeating pattern n times and block B to the repeating pattern p times. In addition, the R-ι group may consist of the terminal chain I as described above and / or the R ₄ group may consist of the end chain I as described above.

In addition, the molar and / or mass ratio between block A and B in the block copolymer, and in particular the m, n and p values of formulas (III) and (IV), will be chosen so that the block copolymer is soluble in the fuel or fuel and / or the organic liquid of the concentrate for which it is intended. Likewise, this ratio and these values m, n and p will be optimized according to the fuel or fuel and / or the organic liquid so as to obtain the best properties when cold.

The optimization of the molar and / or mass ratio, in particular for defining the values m, n and p of the formulas (III) and (IV) can be carried out by routine tests accessible to those skilled in the art. According to one particular embodiment, the molar ratio between the apolar monomer (m _a ) and the polar monomer (m _b ), or between the blocks A and B in molar percentage between the apolar monomer (m _a ) of the block A and the polar monomer (m _b ) of block B is preferably between 95: 5 and 5: 95, more preferably between 70:30 and 30:70.

Other blocks may optionally be present in the block copolymer insofar as they do not fundamentally change the character of the block copolymer. However, block copolymers containing only blocks A and B will be preferred. Advantageously, the block copolymer comprising at least one block A and at least one block B is prepared according to any known process for block copolymerization and controlled from only two types. of α, β-unsaturated monomers.

According to a particular embodiment, the equivalents of the monomers of the block A and of the block B reacted during the polymerization reaction are identical or different and, independently, between 2 and 20, preferably between 3 and 16. By number of equivalents is meant the ratio between the amounts of material (in moles) of the monomers of the block A and the block B during the polymerization reaction. The copolymer described above is used as a cold-holding additive for the fuel or fuel. The term cold-holding additive, an additive that improves the cold-holding properties of a fuel or fuel, especially the cold operability during storage and / or its use at low temperature, typically less than 0 ° C, preferably below -5 ° C.

The copolymer is particularly advantageous as a fuel or fuel additive comprising one or more n-alkyl, iso-alkyl or n-alkenyl substituted compounds having a tendency to crystallize in the fuel or fuel, during storage and / or use at low temperature.

The fuels or fuels may be chosen from liquid hydrocarbon fuels or liquid fuels alone or as a mixture.

The liquid fuel is advantageously derived from one or more sources selected from the group consisting of mineral, animal, vegetable and synthetic sources. Oil will preferably be chosen as a mineral source. The liquid fuel is preferably chosen from hydrocarbon fuels and non-essentially hydrocarbon fuels, alone or as a mixture. Hydrocarbon fuel is a fuel consisting of one or more compounds consisting solely of carbon and hydrogen.

The term "non-substantially hydrocarbon fuel" is understood to mean a fuel consisting of one or more compounds consisting essentially of carbon and hydrogen, that is to say which also contain other atoms, in particular oxygen atoms.

The hydrocarbon fuels or fuels include in particular middle distillates boiling temperature ranging from 100 to 500 ° C. These distillates may, for example, be chosen from distillates obtained by direct distillation of crude hydrocarbons, vacuum distillates, hydrotreated distillates, distillates obtained from catalytic cracking and / or hydrocracking of vacuum distillates, distillates resulting from ARDS type conversion processes (in English "atmospheric residue desulfuration") and / or visbreaking, the distillates from the valuation of Fischer Tropsch cuts. Hydrocarbon fuels or fuels are typically gasoline and diesel (also called diesel fuel).

Gas oils (diesel fuels) include, in particular, any commercially available diesel fuel compositions. As a representative example, mention may be made of gas oils that comply with the NF EN 590 standard.

Non-essentially hydrocarbon fuels or fuels include oxygenates, for example distillates resulting from BTL conversion (in English "biomass to liquid") of plant biomass and / or animal, taken alone or in combination; biofuels, for example oils and / or esters of vegetable and / or animal oils; biodiesels of animal and / or vegetable origin and bioethanols.

Mixtures of hydrocarbon fuel and hydrocarbon fuel are not essentially typically type diesel B or type E _x _x essences. Diesel gasoline type B _x for diesel engines, a diesel fuel which contains x% (v / v) of vegetable or animal oil esters (including used cooking oils) transformed by a chemical process called transesterification, obtained by reacting this oil with an alcohol to obtain fatty acid esters (EAG). With methanol and ethanol, fatty acid methyl esters (EMAG) and fatty acid ethyl esters (EEAG) are obtained respectively. The letter "B" followed by a number indicates the percentage of EAG contained in the diesel fuel. Thus, a B99 contains 99% of EAG and 1% of middle distillates of fossil origin (mineral source), B20, 20% of EAG and 80% of middle distillates of fossil origin, etc. Type B ₀ gas oils which do not contain oxygenated compounds, Bx type gas oils which contain x% (v / v) of vegetable oil or fatty acid esters, most often methyl esters (EMHV or EMAG) . When the EAG is used alone in the engines, the term fuel is designated by the term B100.

The sulfur content of the liquid fuel is preferably less than or equal to 5000 ppm, preferably less than or equal to 500 ppm, and more preferably less than or equal to 50 ppm, or even less than or equal to 10 ppm and advantageously without sulfur. .

The copolymer described above is also used as an anti-sedimentation additive. The copolymer advantageously makes it possible to retard or prevent the sedimentation of the crystals of the n-alkyl, iso-alkyl or n-alkenyl substituted compounds. In particular, the copolymer may advantageously be used to retard or prevent the sedimentation of the crystals of n-alkanes, preferably n-alkanes containing at least 12 carbon atoms, more preferably at least 20 carbon atoms, even more preferably at minus 24. The copolymer, according to the invention, is furthermore used as a cold-holding additive in combination with at least one cold-cooling additive (CFI) improving the low-temperature flow properties of the fuel or fuel during its operation. storage and / or use at low temperatures. The cold-flow-making additive (CFI) is preferably chosen from copolymers and terpolymers of ethylene and of vinyl ester (s) and / or acrylic (s), alone or as a mixture. By way of example, mention may be made of copolymers of ethylene and of unsaturated ester, such as ethylene / vinyl acetate copolymers (EVA), ethylene / vinyl propionate (EVP), ethylene / vinyl ethanoate (EVE), ethylene / methyl methacrylate (EMMA), and ethylene / alkyl fumarate described, for example, in US3048479, US3627838, US3790359, US3961961 and EP261957. The cold-flow additive (CFI) is advantageously chosen from copolymers of ethylene and of vinyl ester (s), alone or as a mixture, in particular ethylene / vinyl acetate (EVA) and ethylene / ethylene copolymers. vinyl propionate (EVP), more preferably ethylene / vinyl acetate copolymers (EVA).

The copolymer is used to amplify the fluidizing (flow) effect of the cold-flow additive (CFI) by improving the temperature limit of filterability (TLF) of the fuel or fuel, the TLF being measured according to the NF EN 1 standard. 16.

This effect, the purpose of which is to improve the Filtration Limit Temperature (TLF), is usually called the "TLF booster" effect insofar as the presence of the copolymer improves the fluidifying nature of the CFI additive. This improvement is reflected, in particular, by a significant decrease in the TLF of the fuel composition or fuel additive with this combination compared to the same fuel composition or fuel additive only with the CFI additive, at the same rate of treatment. Generally, a significant decrease in the TLF results in a reduction of at least 3 ° C. of the TLF according to the NF EN 1 16 standard. In this case, the copolymer has a double effect, "TLF booster" and antisedimentation.

The copolymer may be added to the fuels within the refinery, and / or be incorporated downstream of the refinery, optionally mixed with other additives, in the form of an additive concentrate, also called the use "additive package".

The copolymer is used as a cold-running additive in the fuel or fuel at a content, advantageously at least 10 ppm, preferably at least 50 ppm, more preferably at a content of between 10 and 5 000 ppm, more preferably between 10 and 1 OOOppm.

According to another particular embodiment, an additive concentrate comprises the copolymer as described above, mixed with an organic liquid.

The organic liquid must be inert with respect to the copolymer and miscible with the fuels or fuels as described above. The term "miscible" means that the copolymer, as described according to the invention, and the organic liquid form a solution or a dispersion so as to facilitate the mixing of the copolymer in the fuels according to the conventional methods of additive fuels.

In particular, the organic liquid must be miscible with fuels comprising one or more n-alkyl, iso-alkyl or n-alkenyl substituted compounds having a tendency to crystallize in said fuel or a fuel during its storage and / or of its use at low temperature. The fuel or fuel is preferably selected from gas oils, biodiesel, gasolines type B _x and fuel oils, preferably domestic fuel oils (FOD).

According to a preferred variant, the fuel or fuel is preferably selected from gas oils, biodiesel, gasolines type B _x . The organic liquid is advantageously chosen from aromatic hydrocarbon solvents such as the solvent sold under the name "SOLVESSO", alcohols, ethers and other oxygenated compounds and paraffinic solvents such as hexane, pentane or isoparaffins. alone or in mixture.

The additive concentrate advantageously comprises at least one cold-cooling additive (CFI) improving the cold-resistance, preferably improving the low-temperature flow properties of the fuel or fuel during its storage and / or its use at low temperature. low temperature. The cold-flow-making additive (CFI) is preferably chosen from copolymers and terpolymers of ethylene and of vinyl ester (s) and / or acrylic (s), alone or as a mixture as described herein. -above.

The additive concentrate may also comprise one or more other additives commonly used in fuels or fuels and different from the copolymer described above.

The additive concentrate may typically comprise one or more other additives selected from detergents, anti-corrosion agents, dispersants, demulsifiers, defoamers, biocides, re-deodorants, procetane additives, modifiers lubricant additives or lubricity additives, combustion assistants (catalytic combustion and soot promoters), cloud point improvers, pour point, TLF, agents anti-settling agents, anti-wear agents and / or conductivity modifiers.

Among these additives, mention may be made in particular of:

a) procetane additives, in particular (but not limited to) selected from alkyl nitrates, preferably 2-ethyl hexyl nitrate, aryl peroxides, preferably benzyl peroxide, and alkyl peroxides, preferably ter-butyl peroxide; b) anti-foam additives, in particular (but not limited to) selected from polysiloxanes, oxyalkylated polysiloxanes, and fatty acid amides from vegetable or animal oils. Examples of such additives are given in EP861882, EP663000, EP736590;

c) detergent and / or anti-corrosion additives, in particular (but not limited to) selected from the group consisting of amines, succinimides, alkenylsuccinimides, polyalkylamines, polyalkylamines, polyetheramines, quaternary ammonium salts and triazole derivatives; examples of such additives are given in the following documents: EP0938535, US2012 / 00101 12 and WO2012 / 004300.

d) lubricity additives or anti-wear agents, in particular (but not limited to) selected from the group consisting of fatty acids and their ester or amide derivatives, in particular glycerol monooleate, and monocarboxylic acid derivatives and polycyclic. Examples of such additives are given in the following documents: EP680506, EP860494, WO98 / 04656, EP915944, FR2772783, FR2772784.

e) cloud point additives, including (but not limited to) selected from the group consisting of long-chain olefin terpolymers / (meth) acrylic ester / maleimide, and fumaric acid / maleic acid ester polymers. Examples of such additives are given in FR2528051, FR2528051, FR2528423, EP1 12195, EP172758, EP271385, EP291367;

f) anti-sedimentation additives and / or paraffin dispersants, in particular (but not exclusively) selected from the group consisting of polyamine-amidated (meth) acrylic acid / alkyl (meth) acrylate copolymers, alkenylsuccinimides of polyamine, phthalamic acid derivatives and double chain fatty amine; alkylphenol resins. Examples of such additives are given in the following documents: EP261959, EP593331, EP674689, EP327423, EP512889, EP832172; US2005 / 0223631; US5998530; W093 / 14178.

g) polyfunctional cold operability additives selected from the group consisting of olefin and alkenyl nitrate polymers as described in EP573490; These other additives are generally added in an amount ranging from 100 to 1000 ppm (each). The use of such an additive concentrate may be the same as that of the copolymer described above, in particular, the concentrate may be used to retard or prevent the sedimentation of the crystals of the n-alkyl, iso-substituted compounds, alkyl or n-alkenyl of the fuel or fuel during storage and / or use at low temperatures.

The additive concentrate may advantageously comprise between 5 and 99% by weight, preferably between 10 and 80%, more preferably between 25 and 70% of copolymer as described above. Preferably, the additive concentrate comprises from 5 to 94% by weight of cold-flow additive (CFI), preferably from 10 to 80%, more preferably from 30 to 70%, the percentages being expressed relative to the mass. total additive concentrate.

Advantageously, the ratio between the mass of copolymer and the mass of cold-flow additive (CFI) present in the additive concentrate is from 1: 99 to 99: 1, preferably from

90: 10 to 10:90, more preferably 70:30 to 30:70.

The additive concentrate may, typically, comprise between 1 and 95% by weight, preferably 10 to 70%, more preferably 25 to 60% of organic liquid, the remainder corresponding to the copolymer and, optionally, to the other additives different from the copolymer such as as described above.

In general, the solubility of the copolymer in the organic liquids, the fuels or the fuels described above will depend in particular on the average molar masses by weight and by number, respectively M _w and M _n, of the copolymer. The average molar masses M _w and M _n of the copolymer will be chosen so that the copolymer is soluble in the fuel or fuel and / or the organic liquid of the concentrate for which it is intended. The average molar masses M _w and M _n of the copolymer may also have an influence on the effectiveness of this copolymer as cold-holding additive. We will choose the average molecular weights M _w and M _n so as to optimize the effect of the copolymer, especially the CFPP and anti-settling in the fuels or the fuels described above.

The optimization of the average molar masses M _w and M _n can be carried out by tests routines accessible to those skilled in the art.

According to a particular embodiment, the copolymer advantageously has a weight average molecular weight (Mw) of between 1,000 and 30,000 g. mol ^"1 , preferably between 4000 and 10,000 g, mol ^{" 1} , more preferably less than 4000 g. mol ^"1 , and / or a number-average molar mass (Mn) of between 1,000 and 15,000 g. mol- ¹ , preferably between 4,000 and 10,000 g. mol ^"1 , more preferably less than 4000 g, mol ^{" 1} . The number and weight average molar masses are measured by Size Exclusion Chromatography (SEC). The operating conditions of the SEC, in particular, the choice of the solvent will be chosen according to the chemical functions present within the block copolymer according to the invention.

According to a particular embodiment, a fuel or fuel composition is prepared according to any method known for adding:

(1) a fuel or fuel with,

(2) at least one copolymer and,

(3) a cold-cooling additive (CFI) improving the cold resistance of the fuel or fuel, the fuel or fuel, the copolymer and the cold-flow-making additive (CFI) being as described above.

The copolymer is present in the fuel or fuel composition in an amount sufficient to retard or prevent the sedimentation of the crystals of said n-alkyl, iso-alkyl or n-alkenyl substituted compounds during storage and / or use at low temperatures. temperature of said fuel or fuel (1).

The fuel or fuel composition advantageously comprises at least 10 ppm, preferably at least 50 ppm, advantageously between 10 and 5000 ppm, more preferably between 10 and 1000 ppm of the copolymer described above. The cold-flow-making additive (CFI) is preferably chosen from copolymers and terpolymers of ethylene and of vinyl ester (s) and / or acrylic (s), alone or as a mixture. The cold-flow additive (CFI) is advantageously chosen from copolymers of ethylene and of vinyl ester (s), alone or as a mixture, in particular ethylene / vinyl acetate copolymers (EVA) and ethylene / vinyl propionate (EVP), more preferably ethylene / vinyl acetate copolymers (EVA). The coolant additive (CFI) is present in the fuel or fuel composition in an amount sufficient to improve the low temperature flow behavior of the fuel or fuel (1) during storage and / or use at low temperature.

The fuel or fuel composition advantageously comprises at least 10 ppm, preferably at least 50 ppm, more preferably between 10 and 5000 ppm, even more preferably between 10 and 1000 ppm of the cold-flow additive (CFI). . In addition to the copolymer (2) and the cold-flow-reducing additive (3) described above, the fuel or fuel composition (1) may also contain one or more other additives different from the additives (2) and (3) chosen from detergents, anti-corrosion agents, dispersants, demulsifiers, defoamers, biocides, deodorants, friction modifiers, lubricity additives or lubricity additives, combustion assistants (Catalytic combustion promoters and soot), cloud point improving agents, pour point, TLF, anti-sedimentation agents, anti-wear agents and / or conductivity modifiers.

The additives different from additives (2) and (3) are, for example, those mentioned above.

According to another particular embodiment, a method for improving the cold-holding properties of a fuel or fuel composition derived from one or more sources selected from the group consisting of mineral sources, preferably oil, animal, vegetable and synthetic comprises the successive stages of:

a) determining an additive composition most suitable for the fuel or fuel composition to be treated as well as the treatment rate necessary to reach a given specification relating to the cold-holding properties for the specific fuel or fuel composition, said composition comprising at least the copolymer according to the invention in combination, optionally, with a cold-flow additive (CFI). Alternatively, the additive composition is constituted by the additive concentrate according to the invention.

b) treating the fuel or fuel composition with the amount determined in step a) of the copolymer and, optionally, with the cold-flow additive (CFI). It being understood that the process for improving the cold-holding properties is advantageously intended for a fuel or fuel composition comprising one or more a plurality of n-alkyl, isoalkyl or n-alkenyl substituted compounds having a tendency to crystallize in said fuel or fuel during storage and / or use at a low temperature. Step a) is carried out according to any known process and is common practice in the field of fuel additives. This step involves defining a representative characteristic of the cold-holding properties of the fuel or fuel, for example the low temperature flow characteristics, setting the target value and then determining the improvement that is required to achieve the specification.

The determination of the amount of copolymer to be added to the fuel or fuel composition to achieve the specification will typically be made by comparison with the fuel or fuel composition containing the CFI additive but without block copolymer or statistic.

The amount of copolymer required to treat the fuel or fuel composition may vary depending on the nature and origin of the fuel or fuel, particularly depending on the level of n-alkyl, iso-alkyl or n-alkenyl substituted compounds. . The nature and origin of the fuel or fuel may therefore also be a factor to be taken into account for step a).

The method for improving the cold-holding properties may also comprise an additional step after step b) of checking the target reached and / or adjusting the treatment rate with the copolymer as a cold-holding additive and, optionally, with cold-flow additive (CFI).

The performance of the copolymers as an anti-sedimentation additive (WASA) is evaluated by testing their ability to avoid the sedimentation of fuel compositions additive with conventional EVA. The anti-settling properties of the fuel compositions can be evaluated by the following ARAL sedimentation test: 250mL of the fuel composition are cooled in 250mL test pieces in a climatic chamber at -13 ° C. according to the following temperature cycle: change from + 10 ° C to -13 ° C in 4h then isothermal at -13 ° C for 16h. At the end of the test, a visual quotation of the sample appearance and the sedimented phase volume is performed, then 20% of the lower volume is taken, for PTR (ASTM D7689) and temperature point characterization. filtering limit (TLF) in English CFPP "Cold Filter Plugging Point" in (° C) according to the NF EN 1 16 standard. The PTR deviation is then compared before and after sedimentation (ie on the 20% by volume of the bottom of the test specimen). The smaller the gap, the better the anti-settling effect. Generally, it is believed that an additive has an anti-sedimentation effect when the PTR deviation before and after sedimentation is less than 3.

The performance of each copolymer as a TLF booster additive can also be evaluated by testing their ability to lower the TLF of the fuel compositions additive with conventional EVA.

EXAMPLE

Reaction products:

Polymerization initiator: α, α'-Azoisobutyronitrile, AIBN, (CAS 78-67-1)

- RAFT Transfer Agent:

methyl 2- [methyl (4-pyridinyl) carbamothioylthio] propionate, Dithiocarbamate - To obtain the A-monomers block _a :

Vinyl Laurate, LV

- To obtain block B - Monomer m _b :

4-chloromethylstyrene, CMS

2-dimethylaminoethanol, DMAE

EXAMPLE 1 Synthesis by radical radical polymerization by reversible addition-fragmentation chain transfer (RAFT) of a block copolymer LV (block A) / DMAE-MS _qua t (block B) of following formula:

• Synthesis of the RAFT Agent: Dithiocarbamate

In a 1 L three-necked flask equipped with a magnetic bar and a condenser are introduced 4-methylaminopyridine and 320 ml of tetrahydrofuran (THF). The medium is then degassed and placed under an inert atmosphere (nitrogen). The medium is cooled to -10 ° C and n-Butyl Lithium (n-BuLi) is added dropwise. The exotherm is controlled so as not to exceed the temperature of 0 ° C. The medium is maintained at -10 ° C. for 1 hour. Carbon disulfide (CS ₂ ) is added dropwise to control the exotherm and to remain between -5 ° C and + 5 ° C. A yellow solid appears. The medium is stirred for 2 h at 0 ° C. and then brought to ambient temperature. Methyl 2-bromopropionate is introduced into the reaction medium at one time. The medium is stirred for 2 hours. The solvent is evaporated under reduced pressure. The solid obtained is dissolved in 200 mL of ethyl acetate. The organic phase is washed with 3 χ 200 ml of distilled water with neutral pH control on the last aqueous phase, and then dried over Na ₂ SO ₄ sodium sulphate. The product is then purified on a silica column (450 g of silica). 26.7 g (Yield: 93%) of a pale yellow solid with a purity of 94% (measured by ¹ H NMR) are obtained.

The characteristics are listed in Table 1 below:

Table 1

* Weight-average molecular weight expressed in g / mol and measured by size exclusion chromatography (CES, in English SEC)

• Synthesis of the block copolymer

Obtaining Block A from LV Monomers

In a three-necked flask of 100 mL equipped with a magnetic bar and a condenser are introduced DiThiocarbamate prepared according to the previous protocol, 1,4-dioxane, LV and AIBN. The medium is then degassed and placed under an inert atmosphere (nitrogen) and then heated at 110 ° C. for 26 hours. The medium is then precipitated in 3 × 400 ml of methanol, dissolved in THF and evaporated under reduced pressure. 30.2 g (Yield: 89.69%) of a brown oil are obtained. The characteristics are listed in Table 2 below:

Table 2

(1) Mass-average molecular weight expressed in g / mol and measured by measuring steric exclusion chromatography (CES, in English SEC)

(2) Average number-average molecular weight expressed as g / mol and measured by steric exclusion chromatography (CES, in English SEC)

(3) Polydispersity

(4) Degree of Polymerization (DP) Measured by Size Exclusion Chromatography (SEC)

Obtaining the Block Copolymer LV (Block A) / CMS (Block B)

In a 50 ml three-necked flask equipped with a magnetic bar and a condenser are introduced the previously synthesized A block, para-toluenesulfonic acid (APTS), 1,4-dioxane, CMS and AIBN. The medium is then degassed and placed under an inert atmosphere (nitrogen) and heated at 110 ° C. for 48 hours. At the end of the reaction, the mixture is cooled to room temperature and treated with N, N-diisopropylethylamine (5 eq / APTS) for 1 h. The polymer is then precipitated in 3x400 mL of methanol, dissolved in THF and evaporated under reduced pressure. 9.2 g of a dark brown oil (Yield: 69%) are obtained with a LV / CMS 20 / 3.8 ratio determined by ¹ H NMR.

The quantities and characteristics of the reaction products are listed in the following Table 3:

Table 3

CAS name M _w * m (g) n (mol) eq

CMS 1592-20-7 152.62 4.1 1 0.0269 13.45

BlockA - 4950 10.0 0.0020 1

AIBN 78-67-1 164.21 0.0369 0.0002 0.1

Acid 6192-52-5 190 0.5758 0.0030 1.5 Paratoluenesulfonic acid

1,4-dioxane 123-91-1 - 5.61 - - * Weight-average molecular weight expressed in g / mol and measured by size exclusion chromatography (CES, in English SEC)

Obtaining the LV block copolymer (block A) / DMAE-MS _qua t (block B)

In a 100 ml monocolumn flask equipped with a magnetic bar and a condenser are introduced the previously synthesized LV block copolymer (block A) / CMS (block B), THF and DMAE. The medium is then degassed and placed under an inert atmosphere (nitrogen) and heated at 55 ° C. for 12 hours. The medium is evaporated under reduced pressure. 10.1 g of a brown / black oil diluted in 12.0% by weight toluene (value determined by 1 H NMR) are obtained.

The quantities and characteristics of the reaction products are listed in the following Table 4:

Table 4

Example 2 Evaluation of the Cold Performance of a Copolymer According to the Invention in a Diesel Fuel Composition

A copolymer according to the invention is tested as an anti-sedimentation additive in a diesel engine distillate. For example, the motor distillate may be of type B ₇ , GOM whose characteristics are listed in Table 5 below: GOM GOM (B ₇ )

% Total paraffins measured by

gas chromatography

20.39

two-dimensional (GC ₂ D)

(total% mass) ⁽¹⁾

Number of carbons 7 8 9 10 11

(% mass) * ¹ '0.09 0.19 1.26 2.08 2.11

Number of carbons 12 13 14 15 16

(% mass) * ¹ '1.93 1.67 1.74 1.55 1.24

Number of carbons 17 18 19 20 21

(% mass) * ¹ '1.10 1.16 1.00 0.87 0.74

Number of carbons 22 23 24 25 26

(% mass) * ¹ '0.59 0.36 0.33 0.21 0.14

Number of carbons 27 28

(% mass) * ¹ '0.06 0

TLF (° C) NF EN 116 -7

PTE (° C) ASTM D97 * ²⁾ -12

PTR (° C) ASTM D7689 -8

MV15 (kg / m ³⁾ EN IS012185 * ³ '837.3

Sulfur content (mg / kg) <10

EMHV content (% vol) * ⁴⁾ 7

Distillation ASTM D86 (° C)

0% 5% 10% 20% 30% 40% 50% 60% 70% 80%

163.8 185.1 191.4 205.5 223.8 242.5 261.3 281.1 300.5 318.9

90% 95% 100%

337.2 350.2 360.5

(1) the percentages being expressed in relation to the total mass of the fuel.

(2) Pour point (PTE, in English PP for "For Point")

(3) Density of the fuel measured at 15 ° C

(4) Methyl ester content of vegetable oil Preparation and cold-holding property of fuel compositions

A composition C is prepared by solubilizing 100 ppm by weight of the copolymer (100% of active material) in a gas oil composition containing 300 ppm by weight of a cold-flow additive (CFI). For example, the cold-reducing additive may be an additive marketed by the company TOTAL under the name CP7936C, which is an ethylene-vinyl acetate (EVA of Ethylene-vinyl acetate) comprising 30.5% w / w vinyl acetate and concentrated to 70% w / w in an aromatic solvent (Solvesso 150, sold by ExxonMobil). By way of comparison, a control composition C ₀ corresponding to the diesel fuel containing only 440 ppm by weight of the cold-flow-reducing additive (CFI) is prepared, this rate corresponding to a polymer treatment rate equivalent to that of the composition C.

The performance of the copolymer as an anti-sedimentation additive (WASA) is evaluated by testing its ability to avoid sedimentation of the fuel composition C additive with conventional EVA. The anti-settling properties of the fuel composition C are evaluated by the following ARAL sedimentation test: 250mL of the fuel composition C are cooled in 250mL test pieces in a climatic chamber conditioned at -13 ° C. according to the cycle of next temperature: change from + 10 ° C to -13 ° C in 4h then isothermal at -13 ° C for 16h. At the end of the test, a visual quotation of the sample appearance and volume of the sedimented phase is performed, then 20% of the lower volume is taken, for PTR cloud point characterization (ASTM D7689) and filterability limit temperature TLF (NF EN 1 16). The PTR deviation is then compared before and after sedimentation (i.e. on the 20% by volume of the bottom of the specimen). The smaller the gap, the better the anti-settling effect. Generally, it is believed that an additive has an anti-sedimentation effect when the PTR deviation before and after sedimentation is less than 3.

The copolymer performance is also evaluated as a TLF booster additive by testing its ability to lower the Cold Filter Plugging Point (CFPP) of the fuel composition C additive with conventional EVA.

Claims

Use of a copolymer as an additive to improve the cold-holding properties of a fuel or a fuel, this copolymer being obtained by copolymerization of at least:

(i) an olaire monomer (m _a ) having the following formula (I):

G (l)

With

u = 0 or 1

w = 0 or 1

E = -O- or -NH (Z) -, or -O-CO-, or -NH-CO- or -CO-NH-, where Z is H or a C1-C6 alkyl group, with the proviso that when E = -O-CO- E is connected to the vinyl carbon by the oxygen atom,

G represents a group chosen from a C1-C4 alkyl, an aromatic nucleus, an aralkyl comprising at least one aromatic nucleus and at least one C1-C34 alkyl group, and

(ii) an α, β-unsaturated polar monomer (m _b ) containing at least one styrene derivative or an alpha-methylstyrene derivative.

2. Use according to claim 1, in which the polar monomer (m _b ) is chosen from styrene and alpha-methylstyrene derivatives, the aromatic ring of which is substituted by at least one R group or at least one hydrocarbon chain. Ci -C ₁₂ linear or branched, preferably acyclic, substituted with at least one R moiety, said R group being selected from:

the hydroxyl group,

- a group -OQ, - a group - (OC _y H _2y O) rH,

- a group - (OC _y H _2y O) rQ,

a group -0- (CO) -Q, and

a group - (CO) -OQ,

y is an integer from 2 to 8, f is an integer from 1 to 10 and Q is selected from C 1 to C ₂₄ alkyl chains.

3. Use according to claim 2, wherein the group R is chosen from groups having a primary, secondary or tertiary amine function.

4. The use as claimed in claim 2, in which the polar monomer (m _b ) is chosen from styrene and alpha-methylstyrene derivatives whose aromatic nucleus is substituted by at least one linear C ₁ -C ₁₂ hydrocarbon-based chain. or branched, preferably acyclic, preferably selected from alkyl groups, said chain being substituted by one or more groups containing a quaternary ammonium.

5. Use according to claim 2, wherein the polar monomer (m _b ) is selected from monomers derived from styrene or alpha-methylstyrene whose aromatic ring is substituted by at least one group -O- (CO) - Q being selected from among the alkyls in

6. Use according to claim 2, wherein the polar monomer (m _b ) is chosen from monomers derived from styrene or alpha-methylstyrene whose aromatic ring is substituted by at least one hydroxyl group or by a hydrocarbon chain. Ci to Ci ₂ , linear or branched, preferably acyclic, substituted by at least one hydroxyl group.

7. Use according to any preceding claim wherein the group E of apolar monomer (m _a) is selected from -O-, -NH (Z) - where Z is H or an alkyl group C1-C6, and -O-CO- where E is attached to the vinyl carbon by the oxygen atom.

8. Use according to any one of the preceding claims, wherein in formula (I), w is 0.

The use according to any one of the preceding claims, wherein in the formula (I), the group G is chosen from a C4-C30 alkyl, an aralkyl comprising at least one aromatic ring and at least one C4-C30 alkyl group.

Use according to any one of the preceding claims wherein the copolymer is a block or random copolymer, preferably a block copolymer.

The use according to claim 10, wherein the block copolymer is represented by the following formula (III) or (IV):

(III)

(IV)

in which

m = 0 or 1,

n is an integer ranging from 2 to 50, preferably from 3 to 20,

p is an integer ranging from 2 to 50, preferably from 3 to 20,

R ₀ is chosen from hydrogen or the methyl group, preferably R ₀ is H,

Ri is chosen from hydrocarbon chains, preferably alkyl groups, cyclic or acyclic, saturated or unsaturated, linear or branched Ci to C32, preferably C ₄ -C _24, more preferably a Cio to C ₂₄ and groupings from a radionuclide transfer agent by reversible addition-fragmentation chain transfer (RAFT), it being understood that if R 1 is a group derived from a transfer agent, then m = 0,

R ₂ represents the group - (E) _u -G,

R ₃ is a substituent at the ortho, meta or para position on the aromatic ring, preferably in the para position, selected from the group consisting of at least one R group or at least one C 1 -C 6 hydrocarbon chain; ₂ , linear or branched, preferably acyclic, substituted by at least one R group, said R group being chosen from:

a hydroxyl group or -CH ₂ OH,

C 1 to C ₂₄ , preferably C 1 to C ₁₂ , alkoxy groups _,

. polyalkoxy groups: - (OC _y H _2y O) RR8 where y is an integer from 2 to 8, preferably 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 1 to 10, preferably 2 to 8, more preferably 2 to 4, and R ₈ represents an alkyl to C _24, preferably Ci-Ci ₂

the groups -OCOR ₉ and -COOR ₉ in which R ₉ is chosen from C 1 to C ₂₄ , preferably C 1 to C _2, more preferably C 1 to C ₆ alkyl groups, which are linear or branched, preferably acyclic, and ,

R ₄ is selected from the group consisting of:

- hydrogen;

- OH ;

halogens, preferably bromine; and,

linear or branched, C 1 to C ₃₂ , preferably C 1 to C _24, more preferably C 1 to C ₁₀ , hydrocarbon, cyclic or acyclic, saturated or unsaturated, preferably alkyl groups, said chains being optionally substituted; by one or more groups containing at least one heteroatom selected from N and O, R ₅ and R ₆ are identical or different and independently selected from the group consisting of hydrogen and C 1 to C ₁₀ alkyl, preferably C ₁ to C ₁₀ alkyl groups; at C ₄ , linear or branched, more preferably acyclic, even more preferentially methyl group,

R ₇ is selected from hydrogen or methyl, preferably R ₇ is H.

12. Use of a copolymer as defined in any one of the preceding claims as an anti-sedimentation additive, in particular for retarding and / or preventing the sedimentation of crystals of n-alkyl, isoalkyl or n-substituted-substituted compounds. alkenyl during storage and / or use at low temperatures.

13. Use of a copolymer as defined in any one of claims 1 to 1 1 as an additive to improve the cold-holding properties of a fuel or fuel from one or more sources selected from the group consisting of mineral, animal, plant and synthetic sources, said copolymer being used with at least one cold-cooling additive (CFI) improving the low-temperature flow properties of said fuel or fuel during storage and / or use thereof at low temperature.

14. Use according to claim 13, for amplifying the fluidifying effect of the cold-flow additive (CFI) by improving the Filtration Limit Temperature (TLF) according to standard NF EN 1 16 of said fuel or fuel.

15. An additive concentrate comprising a copolymer as defined in any one of claims 1 to 1 1 and comprising at least one cold-cooling additive (CFI), preferably chosen from ethylene and polyethylene copolymers and terpolymers. vinyl ester (s) and / or acrylic (s), alone or in admixture.

16. Use of a concentrate according to claim 15, for retarding or preventing the sedimentation of the crystals of the n-alkyl, isoalkyl or n-alkenyl substituted compounds of the fuel or fuel during storage and / or use thereof. low temperature.

17. Use according to claim 16, wherein the fuel or fuel is selected from gas oils, biodiesel, mixtures of gas oil and bio-diesel type B _x and fuel oils, preferably domestic fuel oils (FOD). ).

18. Fuel or fuel composition comprising:

(1) fuel or fuel from one or more sources selected from group consisting of mineral, animal, vegetable and synthetic sources,

(2) the copolymer as defined in any one of claims 1 to 1 1, and,

(3) cold-improving cold-forming additive (CFI), preferably chosen from copolymers and terpolymers of ethylene and of vinyl ester (s) and / or acrylic (s) (EVA and or EVP), alone or as a mixture, said additive being present in the fuel or fuel composition in an amount sufficient to improve the low temperature flow behavior of the fuel or fuel (1) during storage and / or its use at low temperature.