EP3487893A1

EP3487893A1 - Copolymer and use thereof as detergent additive for fuel

Info

Publication number: EP3487893A1
Application number: EP17748554.7A
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: FR3054223A1; WO2018015664A1; WO2018015664A9

Abstract

The invention relates to a copolymer and to the use thereof as a detergent additive in an internal combustion engine liquid fuel. The copolymer is obtained by copolymerisation of at least: - one non-polar monomer (m_a) corresponding to Formula (I): and - one polar monomer (m_b) chosen from monomers derived from styrene or from alpha-methylstyrene, the aromatic nucleus of which is substituted with at least one group R or with at least one linear or branched, preferably acyclic, C₁ to C₁₂ hydrocarbon-based chain substituted with at least one group R, said group R being chosen from: - a hydroxyl group, - a group -OR', - a group -(OC_yH_2yO)_f-H, - a group -(OC^yH_2yO)_f-R', - a group -0-(CO)-R', and - a group -(CO)-OR', y is an integer ranging from 2 to 8, f is an integer ranging from 1 to 10 and R' is chosen from C₁ to C₂₄ alkyl chains. The invention also relates to a process for keeping clean and/or for cleaning at least one of the internal parts of an internal combustion engine.

Description

COPOLYMER AND ITS USE AS ADDITIVE DETERGENT FOR

The present invention relates to a copolymer and its use as a detergent additive in a liquid fuel of an internal combustion engine.

The invention also relates to a method for maintaining the cleanliness and / or cleaning of at least one of the internal parts of an internal combustion engine. STATE OF THE PRIOR ART

Liquid fuels from internal combustion engines contain components that can degrade during engine operation. The problem of deposits in the internal parts of combustion engines is well known to motorists. It has been shown that the formation of these deposits has consequences on engine performance and in particular has a negative impact on fuel consumption and particulate emissions. Advances in fuel additive technology have addressed this problem. Additives known as detergents used in fuels have already been proposed to maintain the cleanliness of the engine by limiting the deposits ("Keep-clean" effect) or by reducing the deposits already present in the internal parts of the combustion engine (effect " clean-up "in English). By way of example, mention may be made of US4171959 which describes a detergent additive for petrol fuel containing a quaternary ammonium salt. WO2006135881 discloses a detergent additive containing a quaternary ammonium salt used to reduce or clean deposits including the intake valves. Nevertheless, engine technology is constantly evolving and fuel requirements must evolve to cope with these advances in combustion engine technology. In particular, the new petrol or diesel direct injection systems expose the injectors to more severe pressure and temperature conditions, which favors the formation of deposits. In addition, these new injection systems have more complex geometries to optimize the spraying, including more holes with smaller diameters but, on the other hand, induce greater sensitivity to deposits. The presence of deposits can alter the performance of combustion including increasing pollutant emissions and particulate emissions. Other consequences of the excessive presence of deposits have been reported in the literature, such as increased fuel consumption and maneuverability problems. Preventing and reducing deposits in these new engines is essential for optimal operation of today's engines. There is therefore a need to provide detergent fuel additives promoting optimal operation of combustion engines, especially for new engine technologies.

There is also a need for a universal detergent additive capable of acting on the deposits whatever the engine technology and / or the nature of the fuel. US 2013/012618 A1 discloses a resin composition comprising a copolymer obtained by copolymerization of monomers derived from styrene.

US 2015/183397 A1 discloses a polyelectrolyte comprising two polymeric segments. EP 0 489 550 A1 describes the preparation of homopolymers and / or copolymers of hydroxystyrene by the hydrolysis of homopolymers and / or copolymers of 4-acetoxystyrene.

JP H02 173645 A discloses a photosensitive composition comprising a polymer comprising units derived from vinyl esters of C 1 -C 17 carboxylic acids. JP 2003 286495 A discloses a fuel additive for improving their fluidity at low temperature, said additive being obtained by copolymerization of ethylene and a monomer comprising an aromatic ring.

OBJECT OF THE INVENTION

The Applicant has discovered that the copolymers according to the invention have remarkable properties as a detergent additive in liquid fuels of an internal combustion engine. The copolymers according to the invention used in these fuels make it possible to maintain the cleanliness of the engine, in particular, by limiting or avoiding the formation of deposits (Keep-clean effect) or by reducing the deposits already present in the internal parts of the combustion engine. (clean-up effect).

The advantages associated with the use of such copolymers according to the invention are:

- optimal operation of the motor,

- a reduction in fuel consumption,

- better handling of the vehicle,

- reduced pollutant emissions, and

- economy due to less engine maintenance. The object of the present invention relates to a copolymer obtained by copolymerization of at least:

an olar monomer (m _a ) corresponding to the following formula (I)

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

a polar monomer (m _b ) chosen from monomers derived from styrene or alpha-methylstyrene, the aromatic nucleus of which is substituted by 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:

the hydroxyl group,

a group -OR ',

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

a group - (OCyH _2y O) rR ',

a group -O- (CO) -R ', and

a group - (CO) - OR ',

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

Preferentially, the group G is chosen from a C4-C34 alkyl, an aralkyl comprising at least one aromatic ring and at least one C4-C34 alkyl group. According to an advantageous embodiment, the group E of the apolar monomer (m _a ) is -O-.

According to another advantageous embodiment, the group E of the apolar monomer (m _a ) is -NH (Z) - with Z represents H or a C 1 -C 6 alkyl group.

According to yet another advantageous embodiment, the group E of the apolar monomer (m _a ) is and -O-CO- where E is connected to the vinyl carbon by the oxygen atom. Advantageously, the apolar monomer (m _a ) is such that w is equal to 0.

According to a first preferred variant, the group G of the apolar monomer (m _a ) is a C 4 -C 30 alkyl. According to another preferred 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.

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

According to a particularly preferred embodiment, the copolymer is a block copolymer. In particular, the block copolymer comprises at least:

- a block A consisting of a chain of structural units derived from one or more polar monomers selected from polar monomers (m _a) of formula (I) and,

a block B consisting of a chain of structural units derived from one or more polar monomers chosen from polar monomers (m _b ).

Advantageously, the copolymer comprises at least one block sequence AB, ABA or BAB where said blocks A and B are linked together without the presence of intermediate block of different chemical nature.

According to a particular development, the block copolymer is obtained by sequential polymerization, optionally followed by one or more post-functionalizations. Advantageously, the group R of the polar monomer (m _b ) is chosen from:

the hydroxyl group and,

- a group -0- (CO) -R 'wherein R' is selected from hydrocarbon chains to C _24. According to a preferred embodiment, the polar monomer (m _b) is chosen from monomers derived from styrene or alpha-methylstyrene which the aromatic ring is substituted by at least one group -0- (CO) -R ', R '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. C ₁₂ , linear or branched, preferably acyclic, substituted by at least one hydroxyl group.

The subject of the present invention also relates to a fuel concentrate which comprises one or more copolymers as defined above, in admixture with an organic liquid, said organic liquid being inert with respect to the copolymer (s) and miscible with said copolymer. fuel, said fuel being derived from one or more sources selected from the group consisting of mineral, animal, plant and synthetic sources.

The subject of the present invention further relates to a fuel composition which comprises:

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

(2) one or more copolymers as defined above.

Preferably, the fuel composition comprises at least 5 ppm copolymer (s) as defined above.

According to one embodiment, the fuel composition comprises the copolymer or copolymers as defined above in the form of a concentrate.

The copolymer of the invention is preferably used as a detergent additive in a liquid fuel of an internal combustion engine. Advantageously, the copolymer of the invention is used in a liquid fuel of internal combustion engine, to maintain cleanliness and / or clean at least one of the internal parts of the internal combustion engine. The copolymer is preferably used in the internal combustion engine liquid fuel to limit or prevent the formation of deposits in at least one of the internal parts of the internal combustion engine and / or to reduce the deposits existing in at least one of the internal combustion engine parts. internal parts of said engine. The copolymer is preferably used to reduce the fuel consumption of the internal combustion engine.

The copolymer is preferably used to reduce pollutant emissions, in particular, particulate emissions from the internal combustion engine.

According to a particular embodiment, the internal combustion engine is a spark ignition engine.

According to another particular embodiment, the internal combustion engine is a diesel engine, preferably a direct injection diesel engine. The copolymer may, in this case, be used to limit or avoid and / or reduce the deposits of soap and / or varnish type.

In particular, the copolymer can, in this case, be used to reduce and / or avoid the loss of power due to the formation of deposits in the internal parts of a direct injection diesel engine, said power loss being determined according to the CEC engine test method F-98-08.

The copolymer can also be used to reduce and / or avoid the restriction of the fuel flow emitted by the injector of a direct injection diesel engine during its operation, said flow restriction being determined according to the method of engine test standard CEC F-23-1 -01.

The object of the present invention also relates to a method for maintaining the cleanliness and / or cleaning of at least one of the internal parts of an internal combustion engine comprising at least the following steps:

the preparation of a fuel composition by additivation of a fuel with one or several copolymers and,

the combustion of said fuel composition in said internal combustion engine.

In particular, the internal part of the spark ignition engine kept clean and / or cleaned is selected from the intake system of the engine, in particular the intake valves (IVD), the combustion chamber (CCD or TCD) and the fuel injection system, in particular the injectors of an indirect injection system (IFP) or the injectors of a direct injection system (DISI).

According to another particular embodiment, the internal combustion engine is a diesel engine, preferably a direct injection diesel engine.

In particular, the inner part of the diesel engine kept clean and / or cleaned is the injection system of the diesel engine.

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. According to a particular embodiment, a copolymer is obtained by copolymerizing at least one non-polar monomer (m _a) and at least one polar monomer (m _b).

According to one embodiment, the copolymer is chosen from block copolymers or statistics.

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

The apolar monomer (m _a ) _has the following formula (I)

^G (l)

With

u = 0 or 1

w = 0 or 1

Advantageously, the apolar 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 acylic, 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 C 1 -C 6 alkyl group, preferably CH 3, linear or branched, cyclic or acyclic, preferably acyl, 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

- E = -O-, and

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. 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 ) can also be an aromatic ring. 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, there may be mentioned 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 preferably chosen from monomers derived from styrene or alpha-methylstyrene, the aromatic nucleus of which is substituted by at least one R group or at least one C 1 -C 12 hydrocarbon-based chain, preferably to C _4, linear or branched, preferably acyclic, preferably -CH ₂ -, substituted with at least one group R

The term "hydrocarbon-based chain" means a chain consisting exclusively of carbon and hydrogen atoms, said chain possibly 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 comprise an aliphatic 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. The group R is chosen from:

the hydroxyl group,

- alkoxy groups: -OR ', R' representing 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,

- polyalkoxy groups: - (OC _y H _2y O) rR 'where y is an integer ranging from 2 to 8, and f is an integer ranging from 1 to 10, R' is alkyl to C _24, - carboxylates or alkyl esters: - (CO) -OR ', R' representing an alkyl to C _24,

the alkyl carboxylates or alkyl esters: -O- (CO) -R ', R' representing a C1 to C4 alkyl;

C ₂₄ . The group R is preferably chosen from:

the hydroxyl group,

the alkoxy groups: -OR ', R' representing a C1-C6 alkyl; ₂ ,

- polyalkoxy groups: - (OC _y H _2y O) rH where y is an integer of from 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 2 to 8, more preferably 2 to 4, - polyalkoxy groups: - (OCyH _2y O) rR 'where y is an integer ranging from 2 to 4, more preferably from 2 to 3 and f is an integer ranging from 2 to 8, more preferably 2 to 4, R' representing a C1 to C12 alkyl _,

- carboxylates or alkyl esters: - (CO) -OR ', where R' is alkyl to C _2.

Even more preferably, R is selected from alkyl carboxylates: -0- (CO) -R ', R' representing 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 variant, 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) -R ', R' 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 for example the acetoxy group.

According to this preferred embodiment, the group R is preferably chosen from 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) -R ', R 'is (C ₁ -C ₂₄₎ alkyl, preferably C 1 -C 4 alkyl; ₂ , more preferably C ₁ -C ₈ , still more preferably C ₁ -C ₄ , for example the acetoxy group.

The alkyl carboxylate group -O- (CO) -R 'may be in the ortho, meta or para position on the aromatic ring, preferably in the para position. According to a 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 a hydrocarbon chain Ci-Ci _2, preferably to C _4, linear or branched, preferably acyclic, substituted by at least one hydroxyl group.

According to one particular embodiment, the monomer derived from styrene (m _b ) is represented by the following formula (II):

(II)

In which :

t = 0 yes

g = 0 or 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, in particular selected from -OH, -OR ', -O- (CO) -R' and - (CO) -OR 'with R' being selected from C1 to C hydrocarbon chains ₂₄ , preferably C 1 to C _2, more preferably C 1 to C _8, still more preferably C 1 to C _4. In general, monomers derived from styrene (t = 0) are preferred 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.

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 _(b _m). 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, blocks poly (vinyl phenol) can be obtained from poly blocks (acetoxystyrene) obtained by copolymerization of polar monomers _b m acetoxystyrene, followed by hydrolysis of any known method.

For example, the poly (styrene alkyl ester block) can be obtained from a poly (vinyl phenol) moiety by esterification reaction. 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). 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"); the radical polymerization by nitroxide (NMP in English "Nitroxide-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), dioxane or tetrahydrofuran or apolar solvents, in particular paraffins, cycloparaffins, aromatics and alkylaromatics having from 1 to 19 carbon atoms, 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 the A block is preferably from 2 to 50, preferably from 5 to 50, more preferably from 10 to 50. The number of polar monomer equivalents (m _b ) of the block B is preferably from 2 to 50, preferably from 2 to 40, more preferably from 2 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 (m _b ) of block B. In addition, the molar mass by 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 A and B blocks will be preferred.

Between each block A and B, there may optionally exist an intermediate portion resulting from the random polymerization of the polar monomers (m _b ) and apolar (m _a ), depending on the type of copolymerization chosen and / or the type of initiator or agent of transfer. 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 of which at least one a part is cyclic, especially 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. and co., Australian Journal of Chemistry, 2012, 65, 985-1076. The terminal chain I may, for example, be introduced by aminolysis when a transfer agent is used, in particular 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 removal of hydrogen halide. Aminolysis can be used, for example, for ATRP polymerization which produces a copolymer having a terminal halide or for RAFT polymerization to remove the thio, dithio or trithio linkage introduced into the copolymer by the RAFT transfer agent.

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, Ci to C ₃ 2, preferably C, to C _24, more preferably Ci to C 1 _0, more preferably an alkyl group, optionally substituted with 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.

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 5 to 50, more preferably from 10 to 50, p is an integer ranging from 2 to 50, preferably from 2 to 40, more preferably from 2 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 chain transfer radical polymerization transfer agent by addition-fragmentation (RAFT in English "Reversible Addition-Fragmentation Chain Transfer), it being understood that if Ri is a group resulting 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-propyl benzodithioate.

R ₂ represents the grouping - (E) _u -G

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

R ₃ is a substituent in the ortho, meta or para position on the aromatic ring, preferably in the para position, selected from the group consisting of:

a hydroxyl group or -CH ₂ OH,

the C1- _C24 , preferably C1-C12, 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 from 2 to 8, more preferably from 2 to 4,

- polyalkoxy groups: - (OC _y H _2y O) RR8 where y is as described above, 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 the methyl group,

R ₇ is chosen from hydrogen or the methyl group, preferably R ₇ is H. R 1 is preferably chosen from linear or branched C 1 to C 32 alkyl, cyclic or acyclic, saturated or unsaturated, from preferably C ₄ to C _24, more preferably C ₀ to C ₂₄ .

R ₃ is preferably 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.

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.

The copolymer described above is particularly advantageous when it is used as a detergent additive in a liquid fuel of an internal combustion engine.

By detergent additive liquid fuel is meant an additive that is incorporated in a small amount in the liquid fuel and has an effect on the cleanliness of said engine compared to said liquid fuel not specially additivé. 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. "Non-essentially hydrocarbon fuel" is understood to mean a fuel consisting of one or more compounds consisting essentially of carbon and hydrogen, i.e. say that also contain other atoms, especially oxygen atoms.

Hydrocarbon fuels include in particular medium distillates boiling temperature ranging from 100 to 500 ° C or lighter distillates having a boiling point in the range of gasolines. 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 are typically gasolines and gas oils (also called diesel fuel).

The gasolines include, in particular, all commercially available spark ignition engine fuel compositions. As a representative example, mention may be made of species that comply with the NF EN 228 standard. The essences generally have octane numbers that are sufficiently high to prevent the phenomenon of knocking. Typically, gasoline fuels marketed in Europe, compliant with the NF EN 228 standard, have a motor octane number (MON) of greater than 85 and a research octane number (RON in English). Research Octane Number ") of a minimum of 95. Gasoline fuels generally have an RON of 90 to 100 and a MON of 80 to 90, with RON and MON being measured according to ASTM D 2699- 86 or D 2700-86.

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 include oxygenates, for example distillates resulting from BTL (biomass to liquid) conversion of plant and / or animal biomass, 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 a diesel engine means a diesel fuel which contains x% (v / v) of vegetable or animal oil esters (including used cooking oils) converted 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. E _x type gasoline for a spark ignition engine means a petrol fuel which contains x% (v / v) oxygenates, usually ethanol, bioethanol and / or ethyl tertiary butyl ether. (ETBE).

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 used as a detergent additive in the liquid fuel at a content, preferably at least 10 ppm, preferably at least 50 ppm, more preferably at a content ranging from 10 to 5 000 ppm, even more preferably from 10 to 1 000 ppm.

According to a particular embodiment, the use of a copolymer as described above in the liquid fuel makes it possible to maintain the cleanliness of at least one of the internal parts of the internal combustion engine and / or to clean at least one of the parts internal combustion engine.

The use of the copolymer in the liquid fuel makes it possible, in particular, to limit or avoid the formation of deposits in at least one of the internal parts of said engine (keep-clean effect) and / or to reduce the deposits existing in least one of the internal parts of said engine (effect "clean-up" in English). Thus, the use of the copolymer in the liquid fuel makes it possible, in comparison with the liquid fuel with no particular additives, to limit or avoid the formation of deposits in at least one of the internal parts of said engine or to reduce the deposits existing in at least one of the internal parts. said engine.

Advantageously, the use of the copolymer in the liquid fuel makes it possible to observe both the effects, limitation (or prevention) and reduction of deposits ("keep-clean" and "clean-up" effects).

Deposits are distinguished according to the type of internal combustion engine and the location of deposits in the internal parts of said engine.

According to a particular embodiment, the internal combustion engine is a spark ignition engine, preferably direct injection (DISI in English "Direct Injection Spark Ignition Engine"). The targeted deposits are located in at least one of the internal parts of said spark ignition engine. The internal part of the spark-ignition engine kept clean (keep-clean) and / or cleaned (clean-up) is advantageously chosen from the intake system of the engine, in particular the intake valves (IVD). Intake Valve Deposit "), the" Combustion Chamber Deposit "(CCD) and the fuel injection system, in particular the injectors of an indirect injection system (PFI in English "Port Fuel Injector") or the injectors of a direct injection system (DISI).

According to another particular embodiment, the internal combustion engine is a diesel engine, preferably a direct injection diesel engine, in particular a diesel engine with common rail injection system (IDRC). "). The targeted deposits are located in at least one of the internal parts of said diesel engine.

Advantageously, the targeted deposits are located in the injection system of the diesel engine, preferably located on an external part of an injector of said injection system, for example the nose of the injector and / or on an internal part. of an injector of said injection system (IDID in English "Internai Diesel Injector Deposits"), for example on the surface of an injector needle. The deposits may consist of deposits related to the phenomenon of coking ("coking" in English) and / or deposits soap and / or varnish (in English "lacquering").

The copolymer as described above may advantageously be used in the liquid fuel to reduce and / or avoid the loss of power due to the formation of deposits in the internal parts of a direct injection diesel engine, said power loss being determined according to the CEC standard motor test method F-98-08.

The copolymer as described above may advantageously be used in the liquid fuel to reduce and / or avoid the restriction of the fuel flow emitted by the injector of a direct injection diesel engine during its operation, said restriction of flow determined by the CEC F-23-1-01 engine test method.

Advantageously, the use of the copolymer as described above makes it possible, in comparison with the liquid fuel that is not particularly additive, to limit or avoid the formation of deposits on at least one type of deposits previously described and / or to reduce the deposits existing on at least one of a type of depots previously described.

According to a particular embodiment, the use of the copolymer described above also makes it possible to reduce the fuel consumption of the internal combustion engine.

According to another particular embodiment, the use of the copolymer described above also makes it possible to reduce the emissions of pollutants, in particular the particulate emissions of the internal combustion engine.

Advantageously, the use of the copolymer makes it possible to reduce both the fuel consumption and the pollutant emissions.

The copolymer described above may be used alone, in the form of a mixture of at least two of said copolymers or in the form of a concentrate.

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

The concentrate described above comprises an organic liquid inert with respect to the copolymer described above and miscible in the liquid fuel described above. The term "miscible" means that the copolymer and the organic liquid form a solution or a dispersion so as to facilitate the mixing of the copolymer in liquid fuels according to the conventional fuel additive processes.

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 concentrate may advantageously comprise from 5 to 99% by weight, preferably from 10 to 80%, more preferably from 25 to 70% of copolymer as described above.

The concentrate may typically comprise from 1 to 95% by weight, preferably from 10 to 70%, more preferably from 25 to 60% of organic liquid, the balance corresponding to the copolymer, it being understood that the concentrate may comprise one or more copolymers. as described above.

In general, the solubility of the copolymer in the organic liquids and liquid 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 liquid 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 a detergent additive. The average molar masses M _w and M _n will thus be chosen so as to optimize the effect of the copolymer, in particular the effect of detergency (engine cleanliness) in the liquid fuels described above.

The optimization of the average molar masses M _w and M _n can be carried out by routine tests accessible to those skilled in the art. According to a particular embodiment, the copolymer advantageously has a weight average molecular weight (M _w ) ranging from 500 to 30,000 g. mol ^"1 , preferably from 1000 to 10,000 g. mol ^"1 , more preferably less than or equal to 4000 g. mol ^{" 1} , and / or a number-average molar mass (Mn) ranging from 500 to 15,000 g. mol ^"1 , preferably from 1000 to 10,000 g, mol ^{" 1} , more preferably less than or equal to 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 functions chemicals present within the copolymer.

According to a particular embodiment, the copolymer is used in the form of an additive concentrate in combination with at least one other fuel additive for an internal combustion engine other than the copolymer described above.

The additive concentrate may typically comprise one or more other additives selected from detergent additives different from the copolymer described above, for example from anti-corrosion agents, dispersants, demulsifiers, anti-foam agents, biocides, deodorants, procetane additives, friction modifiers, lubricity additives or lubricity additives, combustion assistants (catalytic combustion promoters and soot), cloud point improvers, pour point, TLF ("Filterability Limit Temperature"), anti-settling agents, anti-wear agents and 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) Cold Flow Improver (CFI) chosen from copolymers of ethylene and 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.

d) lubricity additives or anti-wear agents, including (but not limited to) chosen from the group consisting of fatty acids and their ester or amide derivatives, in particular glycerol monooleate, and mono- and polycyclic carboxylic acid derivatives. 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) detergent additives including (but not limited to) selected from the group consisting of succinimides, polyetheramines and quaternary ammonium salts; for example those described in US4171959 and WO2006135881.

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 molar and / or mass ratio between the polar monomer (m _b ) and the apolar monomer (m _a ) and / or between the block A and B in the block copolymer described above will be chosen so that the copolymer is soluble in the fuel and / or the organic liquid of the concentrate for which it is intended. Likewise, this ratio can be optimized according to the fuel and / or the organic liquid so as to obtain the best effect on engine cleanliness. The optimization of the molar and / or mass ratio 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 from 95: 5 to 70:30, more preferably from 85:15 to 75:25.

According to a particular embodiment, a fuel composition is prepared according to any known method by adding the liquid fuel described above with at least one copolymer as described above. The combustion of this fuel composition comprising such a copolymer in an internal combustion engine has an effect on the cleanliness of the engine compared to the liquid fuel that is not particularly additive and allows, in particular, to prevent or reduce the fouling of the internal parts of said engine. . The effect on the cleanliness of the engine is as previously described in the context of the use of the copolymer.

According to a particular embodiment, the combustion of the fuel composition comprising such a copolymer in an internal combustion engine also makes it possible to reduce the fuel consumption and / or the pollutant emissions.

The copolymer is preferably incorporated in a small amount in the liquid fuel described above, the amount of copolymer being sufficient to produce a detergent effect as described above and thus improve engine cleanliness. The fuel composition advantageously comprises at least 10 ppm, preferably at least 50 ppm, advantageously from 10 to 5000 ppm, more preferably from 10 to 1000 ppm of the copolymer described above.

In addition to the copolymer described above, the fuel composition may also comprise one or more other additives different from the copolymer according to the invention chosen from the other known detergent additives, for example from anti-corrosion agents, dispersants, demulsifiers, anti-foaming agents, biocides, re-deodorants, procetane additives, 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 various additives of the copolymer according to the invention are, for example, the fuel additives listed above.

According to a particular embodiment, the copolymer is a block copolymer as described above.

According to a particular embodiment, a method of keeping clean ("keep-clean") and / or cleaning ("clean-up") of at least one of the internal parts of an internal combustion engine includes less the following steps: the preparation of a fuel composition by additivation of a fuel with one or more copolymers as described above and,

- Combustion of said fuel composition in the internal combustion engine. According to a particular embodiment, the internal combustion engine is a spark ignition engine, preferably direct injection (DISI).

The inner part kept clean and / or cleaned of the spark ignition engine is preferably selected from the engine intake system, in particular the intake valves (IVD), the combustion chamber (CCD or TCD) and the fuel injection system, in particular the injectors of an indirect injection system (IFP) or the injectors of a direct injection system (DISI).

According to another particular embodiment, the internal combustion engine is a diesel engine, preferably a direct injection diesel engine, in particular a diesel engine with Common Rail injection systems (IDRC).

The internal part kept clean and / or cleaned of the diesel engine is preferably the injection system of the diesel engine, preferably an external part of an injector of said injection system, for example the nose of the injector and / or an internal part of an injector of said injection system, for example the surface of an injector needle.

The method of maintaining the cleanliness and / or cleaning comprises the successive steps of:

a) determining the additive most suitable for the fuel, said additive corresponding to the selection of the copolymer or copolymers described above to be incorporated in combination, optionally, with other fuel additives as described above and the determination of the of treatment necessary to achieve a given specification relating to the detergency of the fuel composition.

b) incorporation into the fuel of the selected copolymer or copolymers at the rate determined in step a) and, optionally, the other fuel additives.

The copolymer or copolymers can be incorporated in the fuel, alone or in mixture, successively or simultaneously.

Alternatively, the copolymer (s) may be used in the form of a concentrate or an additive concentrate as described above.

Step a) is carried out according to any known method and is common practice in the field of additive fuel. This step involves defining at least one representative characteristic of the detergency properties of the fuel composition.

The representative characteristic of the fuel detergency properties will depend on the type of internal combustion engine, for example diesel or spark ignition, the direct or indirect injection system and the location in the engine of the targeted deposits for cleaning and / or maintaining cleanliness.

For direct injection diesel engines, the characteristic characteristic of the fuel detergency properties may, for example, correspond to the power loss due to the formation of the deposits in the injectors or the restriction of the fuel flow emitted by the injector at the fuel injector. during the operation of said engine.

The representative characteristic of the detergency properties may also correspond to the appearance of lacquering deposits at the injector needle (IDID). Methods for evaluating the detergent properties of fuels have been widely described in the literature and are subject to general knowledge of those skilled in the art. By way of non-limiting example, the tests standardized or recognized by the profession or the methods described in the following literature are:

For direct injection diesel engines:

- the DW10 method, CEC Standard F-98-08 Engine Test Method, for Measuring Power Loss of Direct Injection Diesel Engines

- the XUD9 method, CEC Standard F-23-1 -01 Issue 5 Engine Test Method, for measuring the fuel flow restriction emitted by the injector

the method described by the Applicant in the application WO2014 / 029770 page 17 to 20, for the evaluation of lacquering deposits (IDID), this method being cited by way of example and / or incorporated by reference into the present application.

For indirect injection controlled ignition engines:

- the Mercedes Benz M102E method, standardized test method CEC F-05-A-93, and

- the Mercedes Benz M1 1 1 method, standardized test method CEC F-20-A-98. These methods make it possible to measure the deposits on the intake valves (IVD), the tests being generally carried out on a Eurosuper gasoline meeting the EN228 standard.

For direct injection spark ignition engines:

- the method described by the plaintiff in the article "Evaluating Injector Fouling in

Direct Injection Spark Ignition Engines ", Mathieu Arondel, Philippe China, Julien Gueit; Conventional and future energy for automobiles; 10th international colloquium; January 20-22, 2015, p.375-386 (Technische Akademie Esslingen by Techn Akad, Esslingen, Ostfildern), for the evaluation of coking deposits on the injector, this method being cited as an example and or incorporated by reference into the present application.

the method described in the document US20130104826, for the evaluation of coking deposits on the injector, this method being cited by way of example and / or incorporated by reference into the present application.

The determination of the amount of copolymer to be added to the fuel composition to reach the specification (step a) described above) will be carried out typically by comparison with the fuel composition but without the copolymer according to the invention, the specification given for the detergency may for example be a target value of power loss according to the DW10 method or a flow restriction value according to XUD9 method mentioned above.

The amount of copolymer may also vary depending on the nature and origin of the fuel, particularly depending on the level of n-alkyl, iso-alkyl or n-alkenyl substituted compounds. Thus, the nature and origin of the fuel may also be a factor to consider for step a).

The cleansing and / or cleaning process may also include an additional step after step b) of checking the target achieved and / or adjusting the additive rate with the copolymer (s) as a detergent additive.

Claims

1. Block copolymer obtained by copolymerization of at least:

an olar monomer (m _a ) corresponding to the following formula (I)

G (I)

With

u = 0 or 1,

w = 0 or 1,

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

the hydroxyl group,

a group -OR ',

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

- a group - (OC _y H _2y O) rR ',

a group -O- (CO) -R ', and

a group - (CO) - OR ',

2. A copolymer according to claim 1, wherein the group E of apolar monomer (m _a) is selected from -O-, -NH (Z) - where Z is H or C1 -C6 alkyl group, or -O- Where E is connected to the vinyl carbon by the oxygen atom.

3. Copolymer according to one of claims 1 and 2, wherein w is equal to 0.

4. Copolymer according to any one of the preceding claims, wherein the group G is selected from a C4-C30 alkyl or an aralkyl comprising at least one aromatic ring and at least one C4-C30 alkyl group.

The block copolymer according to any one of the preceding claims, wherein the copolymer comprises at least:

a block A consisting of a chain of structural units derived from one or more apolar monomers chosen from apolar monomers (m _a ) of formula (I) and,

6. Copolymer according to any one of claims 1 to 5, 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) -R ', R' being chosen from C 1 to C ₂₄ alkyls.

7. Copolymer according to any one of claims 1 to 6, 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 hydroxyl group or by a hydrocarbon chain -C ₁₂ linear or branched, preferably acyclic, substituted by at least one hydroxyl group.

8. Fuel concentrate comprising one or more copolymers according to any one of claims 1 to 7, in admixture with an organic liquid, said organic liquid being inert with respect to the copolymer or copolymers and miscible with said fuel, said fuel being from one or more sources selected from the group consisting of mineral, animal, plant and synthetic sources.

9. Fuel composition that includes:

(2) one or more copolymers obtained by copolymerization of at least:

an apolar monomer (m _a ) corresponding to the following formula (I)

^G (l)

With

u = 0 or 1,

w = 0 or 1,

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

a polar monomer (m _b ) chosen from monomers derived from styrene or alpha-methylstyrene, the aromatic nucleus of which is substituted by 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: - the hydroxyl group,

a group -OR ',

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

a group - (OCyH _2y O) rR ',

a group -O- (CO) -R ', and

a group - (CO) - OR ',

The composition of claim 9, wherein the fuel composition comprises at least 5 ppm copolymer (s) (2).

11. Use as a detergent additive in a liquid fuel of an internal combustion engine of a copolymer obtained by copolymerization of at least:

an apolar monomer (m _a ) corresponding to the following formula (I)

(L)

With

u = 0 or 1,

w = 0 or 1,

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

a polar monomer (m _b ) chosen from monomers derived from styrene or alpha-methylstyrene, the aromatic nucleus of which is substituted by at least one R group or at least one C 1 -C 6 hydrocarbon-based chain; ₂ , linear or branched, preferably acyclic, substituted by at least one R group, said R group being chosen from: - the hydroxyl group,

a group -OR ',

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

a group - (OCyH _2y O) rR ',

a group -O- (CO) -R ', and

a group - (CO) - OR ',

12. Use according to claim 1 1, for:

- maintain cleanliness and / or clean at least one of the internal parts of the internal combustion engine, and / or

- to reduce the fuel consumption of the internal combustion engine, and / or to

- reduce pollutant emissions, in particular, particulate emissions from the internal combustion engine.

13. Use according to claim 1 1, to limit or avoid and / or reduce deposits related to the phenomenon of coking and / or soap-like deposits and / or varnish.

14. A method of maintaining the cleanliness and / or cleaning of at least one of the internal parts of an internal combustion engine comprising at least the following steps:

the preparation of a fuel composition by additivation of a fuel with one or more copolymers obtained by copolymerization of at least:

1 / an olaire monomer (m _a ) corresponding to the following formula (I)

G (l)

With

u = 0 or 1,

w = 0 or 1,

the hydroxyl group,

a group -OR ',

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

- a group - (OC _y H _2y O) rR ',

a group -O- (CO) -R ', and

a group - (CO) - OR ',

y is an integer from 2 to 8, f is an integer from 1 to 10 and R 'is selected from C1 to C ₂₄ alkyl chains

or concentrate according to claim 8 and,

the combustion of said fuel composition in said internal combustion engine.