USE OF CERTAIN CATIONIC POLYMERS AS REFRIGERATION ADDITIVES FOR FUELS

Description

[0001] The present invention relates to the use of particular cationic polymers as cold-keeping additives in fuel and combustible compositions, for example to improve their cold-keeping properties during their storage and / or use at low temperatures.

[0002] The present invention also relates to fuel and combustible compositions additive with such polymers.

[0003] The present invention finally relates to additive compositions (or "additive packages") containing these polymers, in combination with at least one cold flow additive (CFI), as well as a method for lowering the filterability limit temperature of a fuel or combustible composition using such a polymer. STATE OF THE PRIOR ART

[0004] Fuels containing paraffinic compounds, including compounds containing n-alkyl, iso-alkyl or n-alkenyl groups such as paraffinic waxes, are known to exhibit deteriorated flow properties at low temperatures, typically below 0°C. In particular, middle distillates obtained by distillation from crude oils of petroleum origin such as diesel or heating oil are known to contain different amounts of n-alkanes or n-paraffins depending on their source. These compounds tend to crystallize at low temperatures, blocking pipes, lines, pumps and filters, for example in the fuel systems of motor vehicles.In winter or when fuels or combustibles are used at temperatures below 0°C, the crystallization of these compounds can lead to a reduction in the flow properties of the fuels or combustibles and, consequently, cause difficulties during their transport, storage and / or use. The cold operability of fuels or combustibles is a very important property, particularly to ensure cold engine starting. If paraffins are crystallized at the bottom of the tank, they can be carried along during start-up in the fuel circuit and clog, in particular, the filters and pre-filters located upstream of the injection systems (pump and injectors). Similarly, for the storage of domestic fuel oils, if paraffins precipitate at the bottom of the tank, they can be carried along and obstruct the pipes upstream of the pump and the boiler feed system (nozzle and filter).

[0005] These problems are well known in the field of fuels and combustibles, and many additives or additive blends have been proposed and marketed to reduce the size of paraffin crystals and / or change their shape and / or prevent them from forming. The smallest possible crystal size is preferred because it minimizes the risk of filter plugging or clogging.

[0006] Common flow improvers known as cold flow improvers (CFIs) are generally co- and ter-polymers of ethylene and vinyl and / or acrylic ester(s), used alone or in a mixture. These cold flow improvers (CFIs), intended to lower the Filterability Limit Temperature (FLT) and the pour point (FP), inhibit the growth of crystals at low temperatures by promoting the dispersion of paraffin crystals; these are, for example, polymers of ethylene and vinyl acetate and / or vinyl propionate (respectively called EVA or EVP), also commonly called FLT additives. This type of additive, very widely known to those skilled in the art, is systematically added to conventional middle distillates at the refinery outlet. These additivated distillates are used as fuels for diesel engines or as heating fuels.Additional quantities of these additives can be added to fuels sold at service stations, in particular to meet the so-called Extreme Cold specifications.

[0007] To improve both the TLF and the pour point of distillates, it is known to add to these CFI additives additional additives or "boosters" having the function of acting in combination with the CFI additives so as to increase their effectiveness. The prior art describes such combinations of additives extensively.

[0008] By way of example, mention may be made of US patent 3,275,427 describing a middle distillate of a distillation cut between 177 and 400°C containing an additive consisting of 90 to 10% by mass of an ethylene copolymer comprising 10 to 30% of vinyl acetate units with a molar mass by weight of between 1000 and 3000 g.mol -1< and 10 to 90% by mass of a lauryl polyacrylate and / or a lauryl polymethacrylate with a molar mass by weight varying from 760 to 100,000 g.mol -1<.

[0009] Document EP0857776 proposes to use alkylphenol-aldehyde resins resulting from the condensation of alkylphenol and aldehyde in association with ethylene / vinyl ester copolymers or terpolymers, to improve the fluidity of mineral oils.

[0010] Patent application WO 2008 / 006965 describes the use of a combination of a homopolymer obtained from an olefinic ester of a carboxylic acid of 3 to 12 carbon atoms and a fatty alcohol comprising a chain of more than 16 carbon atoms and optionally an olefinic double bond and a cold flow additive (CFI) of the EVA or EVP type, to increase the effectiveness of the CFI additives by amplifying their effect on the TLF.

[0011] Patent application WO 2016 / 128379 describes the use, as a cold resistance additive for a fuel or combustible, of a block copolymer comprising: (i) a block A consisting of a chain of structural units derived from one or more α,β-unsaturated alkyl acrylate or methacrylate monomers, and (ii) a block B consisting of a chain of structural units derived from one or more α,β-unsaturated monomers containing at least one aromatic nucleus.

[0012] This additive is particularly useful as a TLF booster in association with a cold flow additive (CFI).

[0013] In addition to improving the flow of the fuel composition, another purpose of cold-holding additives is to ensure the dispersion of paraffin crystals, so as to delay or prevent the sedimentation of such crystals and to avoid the formation of a paraffin-rich layer at the bottom of containers, tanks or storage reservoirs; these paraffin dispersing additives are called anti-sedimentation additives or WASA (acronym for the English term "Wax Anti-Settling Additive").

[0014] Modified alkylphenol-aldehyde resins have been described in document FR2969620 as an anti-sedimentation additive in combination with a TLF additive.

[0015] Furthermore, document CN 104 193 892 A discloses a copolymer of methacryloyloxyethyl trimethylammonium chloride and dimethyl diallyl ammonium chloride and its use as an antistatic additive in a fuel oil composition. Patent applications WO 2017 / 046526 A and WO 2018 / 125666 A disclose copolymers in accordance with the definition of this claim 1, as well as the use of said copolymers as a detergent additive for fuel or combustible.

[0016] Due to the diversification of fuel and combustible sources, there is always a need to find new additives to improve the low temperature properties of fuels or combustibles, also called cold holding properties, and in particular their flow properties during storage and / or use at low temperatures.

[0017] This need is particularly important for fuels or combustibles comprising one or more paraffinic compounds, for example compounds containing n-alkyl, iso-alkyl or n-alkenyl groups exhibiting a tendency to crystallize at low temperature.

[0018] In particular, distillates used in fuels and combustibles are increasingly derived from more complex refining operations than those from direct distillation of petroleum, and can come in particular from cracking, hydrocracking, catalytic cracking and visbreaking processes. With the growing demand for diesel fuels, the refiner tends to introduce into these fuels more difficult to exploit cuts, such as the heavier cuts from cracking and visbreaking processes which are rich in long-chain paraffins.

[0019] In addition, synthetic distillates from gas processing, such as those from the Fischer Tropsch process, as well as distillates resulting from the processing of biomass of plant or animal origin, such as NexBTL and distillates comprising esters of plant or animal oils, have appeared on the market and constitute a new range of products that can be used as a base for formulating fuels and / or domestic heating oils. These products also include long-chain paraffinic hydrocarbons.

[0020] In addition, we have seen the arrival of new crude oils on the market, much richer in paraffins than those commonly refined and whose filterability temperature of distillates from direct distillation was difficult to improve by conventional filterability additives like those previously mentioned.

[0021] It was found that the cold holding properties of distillates obtained by combining the old bases and these new sources were difficult to improve by adding conventional filterability additives, among other things due to the significant presence of long-chain paraffins and the complex distribution of paraffins in their composition. In fact, in these new combinations of distillates, discontinuous distributions of paraffins were noted, in the presence of which the known filterability additives are not always sufficiently effective.

[0022] There is therefore a need to adapt cold-holding additives to these new types of fuel bases, which are considered particularly difficult to process.

[0023] The present invention applies to fuels and combustibles containing not only conventional distillates such as those from the direct distillation of crude oils, but also to bases from other sources, such as those described above.

[0024] Thus, the aim of the present invention is to propose new additives and concentrates containing them, which can be used as additives in fuel and other fuel compositions to improve their cold holding properties, in particular the cold flow properties at low temperatures typically below 0°C, and better still below -5°C.

[0025] The aim of the present invention is further to propose new additives for fuels and combustibles, and concentrates containing such additives, acting on the Filterability Limit Temperature (FLT), the pour point (FP), and delaying and / or preventing the sedimentation of crystals of hydrocarbon compounds, in particular paraffins. SUBJECT OF THE INVENTION

[0026] The applicant has now discovered that particular cationic polymers, as described below, can be advantageously used as cold resistance additives for fuel and combustibles.

[0027] In particular, these polymers possess unexpected properties for improving the cold resistance of fuel and combustible compositions, including those which are particularly difficult to process.

[0028] The subject of the present invention is thus the use, for improving the cold resistance properties of a fuel or combustible composition, of one or more polymers comprising at least 70 mol% of units of the following formula (I): in which R 1 represents a hydrogen atom or a methyl group, E represents -O-CO-, or -CO-O- or -NH-CO- or -CO-NH-, and G represents a group of formula -R 2 -Q in which R 2 denotes a C 1 to C 34 hydrocarbon chain and Q denotes a group comprising a quaternary ammonium function and optionally one or more hydroxyl groups.

[0029] According to a preferred embodiment, the polymer defined above is used as a so-called “TLF booster” additive, i.e. in combination with a flow improvement additive or cold flow improver (CFI) whose performance it improves.

[0030] The invention also relates to a fuel or combustible composition, comprising: at least one hydrocarbon fraction from one or more sources chosen from the group consisting of mineral (preferably petroleum), animal, vegetable and synthetic sources, at least one polymer as defined above in a content ranging from 0.0001 to 0.005% by weight, relative to the total weight of the composition, and at least one cold-thinning additive chosen from copolymers of ethylene and vinyl ester(s) in a content ranging from 0.005 to 0.5% by weight, relative to the total weight of the composition.

[0031] The invention also relates to an additive composition (or "additive package") comprising such a polymer in association with at least one cold resistance additive different from the polymers according to the invention, as well as an additive concentrate containing such a composition. The cold resistance additive is chosen from copolymers and terpolymers of ethylene and vinyl ester(s), alone or as a mixture. The weight ratio between the content of polymer(s) as defined above on the one hand, and the content of copolymer(s) of ethylene and vinyl ester(s) on the other hand, is in the range from 0.1:100 to 10:100.

[0032] Other objects, characteristics, aspects and advantages of the invention will appear even more clearly on reading the description and examples which follow.

[0033] In what follows, and unless otherwise indicated, the limits of a domain of values ​​are included in this domain, in particular in the expressions "between" and "ranging from ... to ...".

[0034] Furthermore, the expressions “at least one” and “at least” used in this description are respectively equivalent to the expressions “one or more” and “greater than or equal”.

[0035] Finally, in a manner known per se, the term CN compound or group refers to a compound or group containing N carbon atoms in its chemical structure. DETAILED DESCRIPTION The cationic polymer:

[0036] The invention uses a polymer comprising at least 70 mol% of units of the following formula (I): in which R 1 represents a hydrogen atom or a methyl group, E represents -O-CO-, or -CO-O- or -NH-CO- or -CO-NH-, and G represents a group of formula -R 2 -Q in which R 2 denotes a C 1 to C 34 hydrocarbon chain, and Q denotes a group comprising a quaternary ammonium function and optionally one or more hydroxyl groups.

[0037] The group E of formula (I) is chosen from: E = -O-CO-, it being understood that E is then linked to the vinyl carbon by the oxygen atom -O-; E = -CO-O-, it being understood that E is then linked to the vinyl carbon by the carbon atom; E = -NH-CO-, it being understood that E is then linked to the vinyl carbon by the nitrogen atom; and E = -CO-NH-, it being understood that E is then linked to the vinyl carbon by the carbon atom.

[0038] According to a first embodiment, the group E of formula (I) is chosen from: -O-CO- and -NH-CO-, it being understood that the group E=-O-CO- is linked to the vinyl carbon by the oxygen atom and that the group E=-NH-CO- is linked to the vinyl carbon by the nitrogen atom. In this embodiment, the group E is preferably the group -O-CO-.

[0039] According to a second embodiment, the group E of formula (I) is chosen from: -CO-O- and -CO-NH-, it being understood that the group E is linked to the vinyl carbon by the carbon atom. In this embodiment, the group E is preferably the group -CO-O-.

[0040] According to a particularly preferred embodiment, the group E is a -CO-O- group, E being linked to the vinyl carbon by the carbon atom.

[0041] The group G of formula (I) contains a hydrocarbon chain R 2 chosen from C 1 to C 34 hydrocarbon chains, cyclic or acyclic, linear or branched. Preferably R 2 denotes a linear or branched C 1 to C 18 hydrocarbon chain, more preferably C 1 to C 8, even more preferably a linear C 2 to C 4 hydrocarbon chain.

[0042] The quaternary ammonium function(s) of the group Q may be chosen from quaternary ammoniums of pyrrolinium, pyridinium, imidazolium, triazolium, triazinium, oxazolium, isoxazolium, trialkylammonium, iminium, amidinium, formamidinium, guanidinium and biguanidinium, and preferably trialkylammonium.

[0043] According to a particularly preferred embodiment, the group G is represented by one of the following formulas (II) and (III): in which: R 2 is as defined above; X -< is an anion, preferably chosen from hydroxide ions, halide ions and organic anions, preferably from organic anions, R 3 , R 4 and R 5 are identical or different and chosen, independently of each other, from C 1 to C 24 hydrocarbon chains, preferably from C 4 to C 8 , it being understood that the groups R 3 , R 4 and R 5 may contain one or more nitrogenous and / or oxygenated groups and in particular be substituted by one or more hydroxyl group(s) and that the groups R 3 , R 4 and R 5 may be linked together two by two to form one or more cycles, R 6 and R 7 are identical or different and chosen independently from C 1 to C 24 hydrocarbon chains, preferably from C 4 to C 8 ,it being understood that the groups R 6 and R 7 may contain one or more nitrogenous and / or oxygenated groups and in particular be substituted by one or more hydroxyl group(s) and that the groups R 6 and R 7 may be linked together to form a cycle.

[0044] According to a particularly preferred embodiment, the group G is represented by the formula (II) above, in which: R 2 denotes a linear or branched C 1 to C 18 hydrocarbon chain, more preferably C 1 to C 8, even more preferably a linear C 2 to C 4 hydrocarbon chain; R 3 , R 4 and R 5 represent, independently of one another, C 1 to C 18 alkyl groups, preferably C 1 to C 12 alkyl groups, optionally substituted by at least one hydroxyl group, it being understood that at least one of the groups R 3 , R 4 and R 5 contains one or more hydroxyl group(s); X -< is the conjugate base of a carboxylic acid, preferably a monocarboxylic acid containing from 1 to 24 carbon atoms, more preferably from 2 to 18, even more preferably from 2 to 8.

[0045] According to a particularly preferred embodiment, X -< corresponds to the formula R-COO -< with R a linear or branched alkyl group, preferably linear, in C 1 to C 24 , more preferably in C 2 to C 18 , even more preferably in C 2 to C 8 .

[0046] The polymer according to the invention comprises at least 70 mol% of units of formula (I), preferably at least 80 mol%, and better still at least 90 mol%.

[0047] According to a particularly preferred embodiment, the polymer according to the invention is formed from units of formula (I), that is to say that it does not contain units different from the units of formula (I) above. According to a particularly preferred embodiment, the polymer according to the invention is a homopolymer, that is to say that it is formed from a single repeating unit of formula (I).

[0048] The polymer used in the present invention can be obtained by homopolymerization or copolymerization of one or more monomer(s) corresponding to the following formula (IV): wherein R 1 , E and G are as defined above, the preferred variants of R 1 , E and G according to formula (I) described above also being preferred variants of formula (IV).

[0049] In this embodiment, preferably, the polymer used in the invention is obtained by homopolymerization of a single monomer of formula (IV).

[0050] It is understood that it would not be a departure from the invention if the polymer according to the invention were obtained from monomers different from those of formula (IV) above, insofar as the final polymer corresponds to a polymer as defined above. For example, it would not be a departure from the invention if the polymer were obtained by polymerization of monomers different from those of formula (IV), followed by post-functionalization.

[0051] According to a preferred variant, the polymer according to the invention is obtained by polymerization of intermediate monomers corresponding to the following formula (V): in which R 1 and E are as defined above according to formula (I) and G' represents a group of formula -R 2 -P in which R 2 denotes a C 1 to C 34 hydrocarbon chain optionally substituted by one or more hydroxyl group(s), as defined above, and P denotes a group comprising a tertiary amine function capable of leading to the group Q as defined above, by reaction with a quaternization agent.

[0052] It is preferred to polymerize intermediate monomers carrying a tertiary amine function and then in a second step to functionalize the intermediate polymer thus obtained by reacting it with a quaternizing agent, rather than polymerizing monomers already quaternized.

[0053] The quaternizing agent is preferably an epoxide, and preferably an epoxide in combination with a monocarboxylic acid which is preferably a monocarboxylic acid containing from 2 to 12 carbon atoms as described above, preferably 4 to 8 carbon atoms.

[0054] Whether by direct polymerization of monomers of formula (IV) or by polymerization of intermediate monomers of formula (V) followed by post-functionalization, the actual polymerization reaction can be carried out using any known polymerization method. The various polymerization techniques and conditions are widely described in the literature and fall within the general knowledge of those skilled in the art.

[0055] The polymerization is advantageously a block polymerization. The block polymerization may be of the group transfer polymerization (GTP) type or controlled radical polymerization; for example, atom transfer radical polymerization (ATRP); nitroxide-mediated radical polymerization (NMP); degenerative transfer processes such as degenerative iodine transfer polymerization (ITRP-iodine transfer radical polymerization) or reversible addition-fragmentation chain transfer radical polymerization (RAFT);ATRP-derived polymerizations such as polymerizations using initiators for continuous activator regeneration (ICAR) or using activators regenerated by electron transfer (ARGET);

[0056] Examples of RAFT radical polymerization descriptions include the following documents: WO1998 / 01478, WO1999 / 31144, WO2001 / 77198, WO2005 / 00319, WO2005 / 000924.

[0057] The polymer according to the invention advantageously has a number-average molar mass (Mn) of between 500 and 5,000 g.mol -1< , more preferably between 1,200 and 3,000 g.mol -1< . The number-average molar masses of a polymer are, in a manner known per se, measured by nuclear magnetic resonance (NMR). Use:

[0058] The polymer described above is used to improve the cold resistance properties of a fuel or combustible composition, in particular, of a composition chosen from diesel oils, biodiesels, type B x diesel oils and fuel oils such as in particular domestic fuel oils (DFO).

[0059] The fuel or combustible composition is as described below and advantageously comprises at least one hydrocarbon fraction from one or more sources chosen from the group consisting of mineral sources, preferably petroleum, animal, vegetable and synthetic sources.

[0060] Advantageously, the polymer according to the invention is used to improve the low temperature flow properties of the fuel or combustible during its storage and / or its use at low temperature, by lowering its filterability limit temperature (or TLF, measured according to standard NF EN 116) and / or its pour point (or PE, measured according to standard ASTM D 7346) and / or by delaying or preventing the sedimentation of crystals, and preferably by lowering its filterability limit temperature (TLF, measured according to standard NF EN 116).

[0061] The polymer according to the invention can be used to delay or prevent the sedimentation of paraffin crystals and more particularly of n-alkanes, preferably n-alkanes containing at least 12 carbon atoms, more preferably at least 20 carbon atoms, even more preferably at least 24.

[0062] According to a preferred embodiment, the polymer according to the invention is used as a TLF booster additive, i.e. in combination with at least one flow improvement additive or cold flow improver (CFI).

[0063] The cold flow additive (CFI) is preferably chosen from copolymers and terpolymers of ethylene and vinyl ester(s) and / or acrylic ester(s), alone or as a mixture, preferably from ethylene / vinyl acetate copolymers (EVA) and their mixtures with a terpolymer of ethylene, vinyl acetate and another vinyl ester.

[0064] In this embodiment, the polymer according to the invention is used to amplify the fluidizing effect of the cold fluidizing additive, in particular by lowering the filterability limit temperature (FLT) and / or the pour point, and / or by delaying or preventing the sedimentation of crystals, such as those containing paraffins.

[0065] This effect is usually referred to as the "TLF booster" effect since the presence of the polymer according to the invention improves the fluidizing character of the CFI additive. This improvement results, in particular, in a significant reduction in the TLF of the fuel composition or combustible additive with this combination compared to the same fuel composition or combustible additive only with the CFI additive, at the same treatment rate. Generally, a significant reduction in the TLF results in a decrease of at least 3°C ​​in the TLF according to standard NF EN 116.

[0066] According to a particularly preferred embodiment, the polymer is used to amplify the fluidizing (flow) effect of the cold flow additive (CFI) by improving the Filterability Limit Temperature (FLT) of the fuel, the FLT being measured according to standard NF EN 116.

[0067] The polymer can be added to fuels or combustibles within the refinery, and / or be incorporated downstream of the refinery, possibly in a mixture with other additives, in the form of a concentrated composition of additives, also called according to usage "additive package".

[0068] The polymer is advantageously used at a content of at least 0.0001% by weight, relative to the total weight of the fuel or combustible composition.

[0069] Preferably, the content of said polymer ranges from 0.0001 to 0.01% by weight, preferably from 0.0002 to 0.005% by weight, and more preferably from 0.0003 to 0.002% by weight, relative to the total weight of the fuel or combustible composition. The composition of additives:

[0070] The invention also relates to an additive composition comprising a polymer as described above, and at least one cold flow additive (CFI) chosen from copolymers of ethylene and vinyl ester(s), the weight ratio between the content of polymer(s) formed from units of formula (I) on the one hand, and the content of copolymer(s) of ethylene and vinyl ester(s) on the other hand, being in the range from 0.1:100 to 10:100.

[0071] Said copolymers of ethylene and vinyl ester(s) are different from the polymers formed from units of formula (I).

[0072] Copolymers and terpolymers of ethylene and vinyl and / or acrylic ester(s) may be used alone or as a mixture. By way of example, mention may be made of copolymers of ethylene and unsaturated ester, such as ethylene / vinyl acetate (EVA), ethylene / vinyl propionate (EVP), ethylene / vinyl ethanoate (EVE), ethylene / methyl methacrylate (EMMA), and ethylene / alkyl fumarate copolymers described, for example, in documents US3048479, US3627838, US3790359, US3961961 and EP261957. Mention may also be made of terpolymers of ethylene, vinyl acetate and another vinyl ester, for example vinyl neodecanoate.

[0073] According to a preferred embodiment, the copolymers of ethylene and vinyl ester(s) are chosen from ethylene / vinyl acetate copolymers (EVA), ethylene / vinyl propionate copolymers (EVP) and terpolymers of ethylene, vinyl acetate and another vinyl ester; more preferably from ethylene / vinyl acetate copolymers (EVA) and their blends with a terpolymer of ethylene, vinyl acetate and another vinyl ester, such as in particular vinyl neodecanoate.

[0074] The weight ratio between the content of polymer(s) according to the invention on the one hand, and the content of copolymer(s) of ethylene and vinyl ester(s) on the other hand, is in the range from 0.1:100 to 10:100, preferably from 0.5:100 to 5:100. A particularly preferred weight ratio is 1:100 ± 10%.

[0075] The additive composition may also comprise one or more anti-sedimentation additives and / or paraffin dispersants (WASA), different from the polymer according to the invention and the cold-thinning additives described above. These additives may be, in particular, but not limited to, chosen from the group consisting of (meth)acrylic acid / alkyl (meth)acrylate copolymers amidated with a polyamine, polyamine alkenylsuccinimides, phthalamic acid and double-chain fatty amine derivatives; optionally grafted alkylphenol resins. Examples of such additives are given in the following documents: EP261959, EP593331, EP674689, EP327423, EP512889, EP832172; US2005 / 0223631; US5998530; WO93 / 14178.

[0076] Particularly preferred anti-settling and / or paraffin dispersant additives (WASA) are selected from alkylphenol resins and alkylphenol resins grafted for example with functional groups such as polyamines.

[0077] The additive composition may also comprise one or more other additives commonly used in fuels or combustibles, different from the polymer according to the invention and the cold resistance additives described above.

[0078] The additive composition may typically comprise one or more other additives selected from detergents, anti-corrosion agents, dispersants, demulsifiers, biocides, reodorants, procetane additives, friction modifiers, lubricity additives or smoothness additives, combustion aids (catalytic combustion and soot promoters), anti-wear agents and / or conductivity modifying agents.

[0079] Among these additives, we can cite in particular: a) procetane additives, in particular (but not limited to) chosen from alkyl nitrates, preferably 2-ethylhexyl nitrate, aryl peroxides, preferably benzyl peroxide, and alkyl peroxides, preferably tert-butyl peroxide; b) anti-foam additives, in particular (but not limited to) chosen from polysiloxanes, oxyalkylated polysiloxanes, and fatty acid amides derived 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) chosen from the group consisting of amines, succinimides, alkenylsuccinimides, polyalkylamines, polyalkyl polyamines, polyetheramines, quaternary ammonium salts and triazole derivatives; examples of such additives are given in the following documents: EP0938535, US2012 / 0010112 and WO2012 / 004300.It is also advantageous to use block copolymers formed from at least one polar unit and one apolar unit, such as for example those described in patent application FR 1761700 in the name of the Applicant; d) lubrication additives or anti-wear agents, in particular (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.

[0080] The additive composition may advantageously comprise from 0.1 to 50% by weight of polymer as described above, preferably from 0.2 to 20% by weight, and more preferably from 0.5 to 10% by weight, relative to the total weight of the additives present in said additive composition.

[0081] The present invention also relates to an additive concentrate comprising an additive composition as described above, mixed with an organic liquid. The organic liquid is advantageously inert with respect to the constituents of the additive composition, and miscible with fuels or combustibles, in particular those derived from one or more sources chosen from the group consisting of mineral sources, preferably petroleum, animal, vegetable and synthetic.

[0082] The organic liquid is preferably 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 as a mixture.

[0083] The composition of fuel or combustible: The invention also relates to a fuel or combustible composition, comprising: at least one hydrocarbon fraction from one or more sources chosen from the group consisting of mineral, animal, vegetable and synthetic sources, at least one polymer formed from units of formula (I), as defined above in a content ranging from 0.0001 to 0.005% by weight, relative to the total weight of the composition, and at least one cold-thinning additive chosen from copolymers of ethylene and vinyl ester(s) in a content ranging from 0.005 to 0.5% by weight, relative to the total weight of the composition.

[0084] Mineral sources are preferably petroleum.

[0085] The fuel or combustible composition according to the invention advantageously comprises said polymer(s) formed from units of formula (I) in a content ranging from 0.0002 to 0.005% by weight, and better still from 0.0003 to 0.002% by weight, relative to the total weight of the fuel or combustible composition.

[0086] The cold flow additives (CFI) chosen from copolymers of ethylene and vinyl ester(s) are as described above. They are different from the polymers according to the invention formed from units of formula (I).

[0087] The fuel composition advantageously contains between 50 and 1,000 ppm (between 0.005% and 0.1% by weight) in total of cold-thinning additive(s) chosen from copolymers of ethylene and vinyl ester(s).

[0088] The composition may further contain one or more anti-sedimentation additives and / or paraffin dispersants (WASA), different from the polymers according to the invention formed from units of formula (I) and copolymers of ethylene and vinyl ester(s). Such additives are advantageously chosen from those described above.

[0089] The fuels or combustibles may be chosen from liquid hydrocarbon fuels or combustibles, alone or in a mixture. The liquid hydrocarbon fuels or combustibles include in particular middle distillates with a boiling point between 100 and 500°C.These distillates may, for example, be chosen from distillates obtained by direct distillation of crude hydrocarbons, vacuum distillates, hydrotreated distillates, distillates resulting from catalytic cracking and / or hydrocracking of vacuum distillates, distillates resulting from ARDS (atmospheric residue desulfurization) and / or visbreaking conversion processes, distillates resulting from the recovery of Fischer Tropsch cuts, distillates resulting from BTL (biomass to liquid) conversion of plant and / or animal biomass, taken alone or in combination, and / or biodiesels of animal and / or plant origin and / or oils and / or esters of plant and / or animal oils.

[0090] The sulfur content of the fuels or combustibles is preferably less than 5000 ppm, preferably less than 500 ppm, and more preferably less than 50 ppm, or even less than 10 ppm, and advantageously sulfur-free.

[0091] The fuel or combustible is preferably chosen from diesels, biodiesels, type B x diesels and fuel oils, preferably domestic fuel oils (DFO).

[0092] Type B x diesel fuel for diesel engines (compression engines) is a diesel fuel that contains x% (v / v) of vegetable or animal oil esters (including used cooking oils) transformed by a chemical process called transesterification, which reacts this oil with an alcohol to obtain fatty acid esters (FAE). With methanol and ethanol, fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAE) are obtained respectively. The letter "B" followed by a number x ranging from 0 to 100, which indicates the percentage of FAE contained in the diesel. Thus, a B99 contains 99% FAE and 1% middle distillates of fossil origin, B20, 20% FAE and 80% middle distillates of fossil origin, etc.We therefore distinguish between type B 0 diesel fuels which do not contain oxygenated compounds, and type Bx diesel fuels which contain x% (v / v) of vegetable or animal oil esters or fatty acids, most often methyl esters (EMHV or EMAG). When EAG is used alone in engines, the fuel is referred to as B100.

[0093] The fuel or combustible may also contain hydrogenated vegetable oils, known to those skilled in the art as HVO (from the English “hydrotreated vegetable oil”) or HDRD (from the English “hydrogenation-derived renewable diesel”).

[0094] According to a preferred embodiment, the fuel is chosen from diesels, biodiesels, B x type diesels, hydrogenated vegetable oils (HVO), and mixtures thereof.

[0095] The fuel or combustible composition may also contain one or more additional additives, different from the polymers according to the invention and the cold resistance additives described above. Such additives may in particular be chosen from detergents, anti-corrosion agents, dispersants, demulsifiers, anti-foam agents, biocides, reodorants, procetane additives, friction modifiers, lubricity additives or smoothness additives, combustion aid agents (catalytic combustion and soot promoters), anti-wear agents and / or conductivity modifying agents, as described above.

[0096] These additional additives may generally be present in amounts ranging from 10 to 1,000 ppm (each).

[0097] According to another embodiment of the invention, a method for improving the cold resistance properties of a fuel composition comprises a step of adding to said composition a polymer formed from units of formula (I) as defined above.

[0098] According to one embodiment, this method comprises the successive steps of: a) determining a composition of additive(s) suitable for the fuel or combustible composition to be treated as well as the treatment rate, said composition of additive(s) comprising at least one polymer according to the invention formed from units of formula (I) and, optionally, at least one cold-thinning additive chosen from copolymers of ethylene and vinyl ester(s), different from the polymers formed from units of formula (I); b) treating the fuel or combustible composition with the quantity determined in step a) of said composition of additive(s).

[0099] The method of improving cold holding properties is typically intended for a fuel or combustible composition as described above.

[0100] Step (a) is carried out according to any known method and is common practice in the field of fuel or combustible additives. This step involves defining a characteristic representative of the cold holding properties of the fuel or combustible, for example the low temperature flow characteristics, setting the target value (including a given specification relating to the cold holding properties), and then determining the improvement required to achieve such a target value.

[0101] For example, a specification relating to cold resistance may be a European Extreme Cold specification defining, in particular, a maximum TLF according to standard NF EN 116. The determination of the quantity of additive composition(s) to be added to the fuel or combustible composition to achieve the specification will typically be carried out by comparison with the fuel or combustible composition without said additive composition(s).

[0102] The amount of additive composition required to treat the fuel composition may vary depending on the nature and origin of the fuel, in particular the level and nature of the paraffinic compounds it contains. The nature and origin of the fuel may therefore also be a factor to be taken into account for step a).

[0103] The method for improving cold holding properties may also comprise an additional step after step b) of verifying the target achieved and / or adjusting the treatment rate with the additive composition(s).

[0104] The following examples are given as illustrations of the invention, and should not be interpreted in such a way as to limit its scope. EXAMPLES Example 1: Synthesis of polymers according to the invention Starting compounds :

[0105] Amino monomer: Dimethylaminoethyl acrylate (2439-35-2) Initiator: 2,2'-Azobis-(2-methylpropionitrile) (AIBN) (CAS 78-67-1) Transfer agent (RAFT): 2-cyano-2-propyl dodecyl trithiocarbonate (CAS 870196-83-1) Solvent: 1,4-dioxane (CAS 123-91-1). 1.1. Protocol for the synthesis of an intermediate amino polymer:

[0106] 10.0 g (69.84 mmol) of amine monomer are introduced into a 50 mL single-necked flask, then 3.02 g (8.7 mmol) of RAFT agent and 11.2 g of 1,4-dioxane are added. The flask is then degassed for 30 minutes under nitrogen and magnetic stirring, then sealed. In parallel, 0.179 g (1.09 mmol) of AIBN are introduced into a second 25 mL flask, along with 2.0 g of 1,4-dioxane as a dissolution solvent. The second flask is in turn degassed for 30 minutes under nitrogen. The AIBN solution is then transferred using a nitrogen-purged syringe into the 50 mL flask, previously heated to 80°C, to start the polymerization. The reaction is left for 24 hours.

[0107] A sample is taken for characterization in order to determine by NMR the number-average molar mass and the conversion of the reaction. The intermediate polymer thus obtained has a number-average molar mass Mn of 1500 G.mol -1< which corresponds to an average of 8 units of formula (I) per polymer chain. The conversion rate is 99% by weight (i.e. 1% by weight of residual monomer).

[0108] Two polymers P1 and P2 according to the invention were prepared, by quaternization of the intermediate amino polymer above, in accordance with the protocols below. 1.2. Preparation of polymer P1:

[0109] 2eq (0.138 mol) of epoxyoctane and acetic acid are added to the reaction medium obtained at the end of the synthesis protocol described in 1.1 above, as well as 13g of butanol. The mixture is heated to 60°C and left stirring at constant temperature for 12h. The solvent is then evaporated at reduced pressure (55 mbar) in order to recover the polymer P1 formed.

[0110] The latter is characterized by NMR in order to determine the quaternization rate. The quaternization rate of the polymer P1 thus obtained is 100% (in molar percentage). Preparation of polymer P2:

[0111] 2eq (0.138 mol) of epoxybutane and octanoic acid are added to the reaction medium obtained at the end of the synthesis protocol described in 1.1 above, as well as 13g of butanol. The mixture is heated to 60°C and left stirring at constant temperature for 12h. The solvent is then evaporated at reduced pressure (55 mbar) in order to recover the polymer P2 formed.

[0112] The latter is characterized by NMR in order to determine the quaternization rate. The quaternization rate of the P2 polymer thus obtained is 100% (in molar percentage). Example 2: Evaluation of cold resistance performance

[0113] The polymers P1 and P2 described in example 1 were tested as cold resistance additives in a particularly difficult-to-treat diesel fuel composition G, the characteristics of which are detailed in table 1 below: [Table 1] Characteristic Method Value Density at 15°C ISO 12185 831.2 kg / m 3< Viscosity at 20°C ISO 3104 5.1 mm 2 < / s Viscosity at 40°C ISO 3104 3.5 mm 2 < / s Cloud Point (CTP)° EN 23015 -3 °C Filterability Limit Temperature (FLT) IN 116 -2°C Pour point (PTE) ASTM D 7346 -12 °C Paraffin content 21.42% by weight C16+ n-paraffin content 11.30% by weight Distillation profile D86 ISO 3405 Initial point 173,0 °C Point at 5% vol. 196,6 °C Point at 10% vol. 215,4 °C Point at 20% vol. 243,4 °C Point at 30% vol. 261,9 °C Point at 40% vol. 276,0 °C Point at 50% vol. 287,7 °C Point at 60% vol. 299,3 °C Point at 70% vol. 311,4 °C Point at 80% vol. 325,5 °C Point at 90% vol. 343,7 °C Point at 95% vol. 356,2 °C Full stop 359,0 °C Distilled volume 97,4 ml Residue 0,6 ml Losses 1,8 ml

[0114] Diesel composition G was added with a conventional cold resistance additive A, which consists of the following two commercial cold-thinning additives (CFI additives), in Solvesso 150 solvent: 0.5% by weight of additive marketed by the company Total Additifs Carburants Spéciaux, and which is an ethylene / vinyl acetate (EVA) copolymer with a molecular mass of between 2000 and 6000 gmol -1 <; 0.5% by weight of Dodiflow D4134 additive marketed by the company Clariant, and which is an ethylene / vinyl acetate / vinyl ester terpolymer.

[0115] Additive A was incorporated into diesel composition G at a content of 300 ppm by weight of active material relative to the total weight of the diesel composition.

[0116] This resulted in the G1 additive diesel composition. This has a filterability limit temperature (TLF, standard EN 116) of -6°C.

[0117] The performance as cold resistance additives of each of the polymers P1 and P2 of example 1 was tested, by evaluating their ability to lower the filterability limit temperature (TFL) of the additive diesel composition G1.

[0118] Each polymer was added at a content of 3 ppm by weight (0.0003% by weight) to composition G1, to give diesel G2, the TLF of which was then measured, in accordance with standard EN 116.

[0119] The results obtained are shown in Table 2 below: [Table 2] Product TLF (°C) Diesel G2 TFL gain compared to diesel G Diesel G -2°C - Diesel G1 (300 ppm A) -6°C 4°C Diesel G2 (300 ppm A + 3 ppm P1) -12°C 10°C Diesel G2' (300 ppm A + 3 ppm P1) -12°C 10°C

[0120] The above results show that the use of the polymers according to the invention, even used at very low contents, leads to a very significant reduction in the TLF.

Claims

1. Use, to improve the cold holding properties of a fuel or fuel composition, of one or more polymers comprising at least 70% in moles of units of the following formula : wherein R1 represents a hydrogen atom or a methyl group, E represents -O-CO-, or -CO-O- or -NH-CO- or -CO-NH-, and G represents a group of formula -R2 -Q wherein R2 denotes a C1 to C34 hydrocarbon chain and Q denotes a group comprising a quaternary ammonium function and optionally one or more hydroxyl groups.

2. Use according to the preceding claim, characterised in that the group E of the formula (I) is chosen from -CO-O-and -CO-NH-, it being understood that the group E is bonded to the vinyl carbon by the carbon atom, and preferably the group E is -CO-O-.

3. Use according to any one of the preceding claims, characterised in that the group G is represented by one of the following formulas (II) and (III): wherein: R2 is as defined in claim 1; X - is an anion, preferably selected from hydroxide ions, halides and organic anions, preferably from organic anions, R3, R4 and R5 are identical or different and chosen, independently of one another, from C1 to C24 hydrocarbon chains, preferably from C4 to C8, it being understood that the R3, R4 and R5 groups can contain one or more nitrogen and / or oxygenated groups and in particular be substituted with one or more hydroxyl group (s) and that the R3, R4 and R5 groups can be linked together two by two to form one or more rings, R6 and R7 are identical or different and independently selected from C1 to C24 hydrocarbon chains, preferably from C4 to C8, it being understood that the groups R6 and R7 can contain one or more nitrogen and / or oxygenated groups and in particular be substituted with one or more hydroxyl group (s) and that the R6 and R7 groups can be bonded together to form a ring, and preferably the group G is of formula (II).

4. Use according to the preceding claim, characterised in that the group G is represented by the formula (II) above, wherein: R2 denotes a linear or branched C1 to C18 hydrocarbon chain, more preferably C1 to C8, even more preferably a linear C2 to C4 hydrocarbon chain; R3, R4 and R5 represent, independently of each other, C1 to C18 alkyl groups, preferably C1 to C12, optionally substituted with at least one hydroxyl group, it being understood that at least one of the groups R3, R4 and R5 contains one or more hydroxyl group(s); X - is the conjugate base of a carboxylic acid, preferably of a monocarboxylic acid containing from 1 to 24 carbon atoms, more preferentially from 2 to 18, even more preferentially from 2 to 8.

5. Use of a polymer according to any one of the preceding claims, to lower the cold filter plugging point of the fuel or fuel composition measured according to standard NF EN 116 and / or the pour point measured according to standard ASTM D 7346, and / or to delay or prevent the sedimentation of crystals, and preferably to lower the cold filter plugging point measured according to standard NF EN 116.

6. Use according to any one of the preceding claims, characterised in that said polymer is used in combination with at least one cold flow additive, preferably selected from copolymers and terpolymers of ethylene and vinyl esters and / or acrylic esters, alone or in mixture, preferably selected from ethylene / vinyl acetate (EVA) copolymers and mixtures thereof with an ethylene, vinyl acetate and other vinyl ester terpolymer.

7. Use according to any one of the preceding claims, characterised in that the content of polymer formed of units of formula (I) ranges from 0.0001 to 0.01% by weight, preferably from 0.0002 to 0.005% by weight, and more preferably from 0.0003 to 0.002% by weight, relative to the total weight of the fuel or fuel composition.

8. A fuel or fuel composition, comprising: - at least one hydrocarbon fraction from one or more sources selected from the group consisting of mineral (preferably petroleum), animal, plant and synthetic sources, - at least one polymer as defined in any one of claims 1 to 4 in a content ranging from 0.0001 to 0.005% by weight, relative to the total weight of the composition, and - at least one cold flow additive selected from ethylene and vinyl ester(s) copolymers in a content ranging from 0.005 to 0.5% by weight, relative to the total weight of the composition.

9. Composition according to the preceding claim, characterised in that it contains said polymer(s) formed from units of formula (I) in a content of 0.0002 to 0.005% by weight, and more preferably 0.0003 to 0.002% by weight, relative to the total weight of the fuel or fuel composition.

10. Composition according to one of claims 8 and 9, characterised in that the copolymers of ethylene and vinyl ester(s) are selected from ethylene / vinyl acetate (EVA) copolymers, ethylene / vinyl propionate (EVP) copolymers, and terpolymers of ethylene, vinyl acetate and another vinyl ester; more preferentially selected from ethylene / vinyl acetate (EVA) copolymers and mixtures thereof with an ethylene, vinyl acetate and another vinyl ester terpolymer, such as in particular vinyl neodecanoate.

11. Composition according to one of claims 8 to 10, characterised in that it contains between 0.005% and 0.1% by weight in total of cold flow additive(s) selected from ethylene and vinyl ester(s) copolymers.

12. Composition of additives comprising a polymer as defined in one of claims 1 to 4, and at least one cold flow additive selected from ethylene and vinyl ester(s) copolymers, the weight ratio between content of polymer formed from units of formula (I) on the one hand, and the content of ethylene and vinyl ester(s) copolymer(s) on the other hand, being within the range from 0.1: 100 to 10: 100.

13. Composition of additives according to the preceding claim, characterised in that the copolymers of ethylene and vinyl ester(s) are selected from ethylene / vinyl acetate (EVA) copolymers, ethylene / vinyl propionate (EVP) copolymers, and terpolymers of ethylene, vinyl acetate and another vinyl ester; more preferentially selected from ethylene / vinyl acetate (EVA) copolymers and mixtures thereof with an ethylene, vinyl acetate and another vinyl ester terpolymer, such as in particular vinyl neodecanoate.

14. Composition of additives according to one of claims 12 or 13, characterised in that the weight ratio between content of polymer formed from units of formula (I) on the one hand, and the content of ethylene and vinyl ester(s) copolymer(s) on the other hand, is in the range from 0.5: 100 to 5: 100, and more preferably the weight ratio is 1: 100, ± 10%.