EP4045618A1

EP4045618A1 - Use of particular cationic polymers as cold-resistant additives for fuels

Info

Publication number: EP4045618A1
Application number: EP20785537.0A
Authority: EP
Inventors: Ana Maria CENACCHI-PEREIRA
Original assignee: TotalEnergies Onetech SAS
Current assignee: TotalEnergies Onetech SAS
Priority date: 2019-10-14
Filing date: 2020-10-08
Publication date: 2022-08-24
Also published as: FR3101882B1; WO2021074006A1; FR3101882A1

Abstract

The present invention relates to the use, as a cold-resistant additive in a fuel composition, of one or more polymers comprising at least 70 mol% of units of formula (I), 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. The present invention also concerns fuel compositions with such polymers as additives, as well as additive compositions (or "additive packages") containing these polymers, in combination with at least one cold fluidifying additive (CFI).

Description

DESCRIPTION

TITLE: Use of particular cationic polymers as cold strength additives for fuels and fuels The present invention relates to the use of particular cationic polymers as cold strength additives in fuel and fuel compositions, for example to improve their cold resistance properties during storage and / or use at low temperature. The present invention also relates to fuel and fuel compositions supplemented with such polymers.

The present invention finally relates to additive compositions (or "additive packages") containing these polymers, in combination with at least one cold thinning additive (CFI), as well as a method for lowering the limit temperature of filterability d. a fuel or fuel composition using such a polymer.

STATE OF THE PRIOR ART

Fuels or fuels containing paraffinic compounds, especially compounds containing n-alkyl, iso-alkyl or n-alkenyl groups such as paraffin waxes, are known to exhibit deteriorated flow properties at low temperatures, typically below 0 ° C. In particular, it is known that the middle distillates obtained by distillation from crude oils of petroleum origin such as gas oil or domestic fuel oil contain different amounts of n-alkanes or n-paraffins depending on their origin. These compounds tend to crystallize at low temperature, blocking pipes, conduits, pumps and filters, for example in the fuel circuits of motor vehicles. In winter or under conditions of use of fuels or fuels at a temperature below 0 ° C, the phenomenon of crystallization of these compounds can lead to a reduction in the flow properties of the fuels or fuels and, by therefore cause difficulties during transport, storage and / or use. The cold operability of fuels or combustibles is a very important property, in particular to ensure the starting of cold engines. If paraffins crystallize at the bottom of the tank, they can be entrained on start-up in the fuel circuit and in particular clog the filters and prefilters placed upstream of the injection systems (pump and injectors). Likewise, for the storage of domestic fuel oils, if paraffins precipitate at the bottom of the tank, they can be entrained and obstruct the pipes upstream of the pump and the boiler supply system (nozzle and filter).

These problems are well known in the field of fuels and fuels, and many additives or additive mixtures 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 clogging or clogging of the filters.

The usual so-called cold flow improvers (CFI) are generally co- and ter-polymers of ethylene and of vinyl ester (s) and / or acrylic (s), used alone or as a mixture. These cold thinning additives (CFI), intended to lower the Limit Temperature of Filterability (TLF) and the pour point (PE), inhibit the growth of crystals at low temperature 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 TLF additives. This type of additive, very widely known to those skilled in the art, is systematically added to conventional middle distillates at the outlet of the refinery. These distillates with additives are used as fuels for diesel engines or as heating fuels. Additional quantities of these additives can be added to fuels sold in service stations, in particular to meet the so-called Extreme Cold specifications. To improve both the TLF and the pour point of the 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 them. efficiency. The prior art describes extensively such combinations of additives.

By way of example, mention may be made of patent US Pat. No. 3,275,427, describing a middle distillate from a distillation cut of between 177 and 400 ° C containing an additive consisting of 90 to 10% by weight of an ethylene copolymer comprising from 10 to 30% of vinyl acetate units with a molar mass by weight of between 1000 and 3000 g. mol ¹ and from 10 to 90% by weight of a poly laurylacrylate and / or a polymethacrylate of lauryl with a molar mass by weight varying from 760 to 100,000 g. mol ¹ .

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

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

Patent application WO 2016/128379 describes the use, as an additive for the cold resistance of a fuel or fuel, of a block copolymer comprising:

(i) an A block consisting of a chain of structural units derived from one or more α, b-unsaturated alkyl acrylate or methacrylate monomers, and (ii) a B block consisting of a chain of structural units derived from one or more a, b-unsaturated monomers containing at least one aromatic nucleus.

This additive is in particular useful as a TLF booster in combination with a cold thinning additive (CFI). Besides improving the flow of the fuel or fuel composition, another object of cold-resistance additives is to ensure the dispersion of the paraffin crystals, so as to delay or prevent the sedimentation of such crystals and of avoid the formation of a layer rich in paraffins at the bottom of containers, tanks or storage tanks; these paraffin dispersing additives are called anti-sedimentation additives or WASA (acronym for the English term “Wax Anti-Settling Additive”).

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

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

This need is particularly important for fuels or fuels 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.

In particular, the distillates used in fuels and fuels are increasingly derived from more complex refining operations than those derived from the direct distillation of petroleum, and may originate 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 cuts that are more difficult to exploit, such as the heavier cuts resulting from cracking and visbreaking processes which are rich in long-chain paraffins.

In addition, synthetic distillates resulting from the transformation of gas such as those resulting from the Fischer Tropsch process, as well as distillates resulting from the treatment of biomass of plant or animal origin, such as NexBTL in particular and distillates comprising esters of vegetable 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 fuel oils. These products also include hydrocarbons with long paraffinic chains.

In addition, we noted 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 hardly improved by additives of conventional filterability in the same way. than those previously mentioned.

It was found that the cold resistance properties of the distillates obtained by combining the old bases and these new sources were hardly improved by the addition of conventional filterability additives, among other things due to the large presence of long-chain paraffins. and the complex distribution of paraffins in their composition. It has in fact been possible to note, in these new combinations of distillates, discontinuous distributions of paraffins, in the presence of which the known filterability additives are not always sufficiently effective.

There is therefore a need to adapt the cold resistance additives to these new types of bases for fuels and fuels, considered to be particularly difficult to process. The present invention applies to fuels and fuels containing not only conventional distillates such as those obtained from the direct distillation of crude oils, but also to bases obtained from other sources, such as those described above.

Thus, the aim of the present invention is to provide new additives and concentrates containing them, which can be used as additives in fuel compositions and other fuels in order to improve their cold resistance properties, in particular their properties. cold flow at low temperature typically less than 0 ° C, and better still less than -5 ° C. The object of the present invention is furthermore to provide new additives for fuels and fuels, and concentrates containing such additives, acting on the Limit Filtrability Temperature (TLF), the pour point (PE), and retarding and / or preventing the sedimentation of crystals of hydrocarbon compounds, in particular paraffins.

OBJECT OF THE INVENTION The Applicant has now discovered that particular cationic polymers, as described below, could be advantageously used as cold resistance additives for fuel and fuels.

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

A subject of the present invention is thus the use, to improve the cold resistance properties of a fuel or fuel composition, of one or more polymers comprising at least 70% by moles of units of formula (I) below : 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 -R2-Q in which R2 denotes a C 1 -C 34 hydrocarbon chain and Q denotes a group comprising a quaternary ammonium function and optionally one or more hydroxyl groups.

According to a preferred embodiment, the polymer defined above is used as an additive called "TLF booster", that is to say in combination with an additive for improving flow or cold liquefying additive (in English "cold flow improvers ”or CFI) whose performance it improves.

A subject of the invention is also a fuel or fuel composition, comprising: at least one cut of hydrocarbons obtained from one or more sources chosen from the group consisting of mineral (preferably petroleum), animal sources. , vegetable and synthetic,

- at least one polymer as defined above, and

- at least one cold thinning additive chosen from copolymers of ethylene and vinyl ester (s).

A subject of the invention is also an additive composition (or “additive package”) comprising such a polymer in combination with at least one cold resistance additive different from the polymers according to the invention, as well as a concentrate of additives containing such a composition. The cold resistance additive is chosen from copolymers and terpolymers of ethylene and of vinyl ester (s) and / or acrylic (s), alone or as a mixture.

Finally, a subject of the invention is a method for lowering the limit filterability temperature of a fuel or fuel composition, comprising adding to said fuel or fuel composition of a polymer according to the invention.

Other objects, characteristics, aspects and advantages of the invention will emerge even more clearly on reading the description and the examples which follow. 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 ...".

Moreover, the expressions "at least one" and "at least" used in the present description are respectively equivalent to the expressions “one or more” and “greater than or equal”.

Finally, in a manner known per se, the term “C _N compound or group” denotes a compound or a group containing in its chemical structure N carbon atoms.

DETAILED DESCRIPTION

The cationic polymer:

The invention uses a polymer comprising at least 70 mol% of units of formula (I) below: 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 -R2-Q in which R2 denotes a C 1 to C34 hydrocarbon chain, and Q denotes a group comprising a quaternary ammonium function and optionally one or more hydroxyl groups.

The group E of formula (I) is chosen from:

-E = -O-CO-, it being understood that E is then connected 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 connected 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. 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 = -0-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-.

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 via the carbon atom. In this embodiment, the group E is preferably the group -CO-O-.

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

The group G of formula (I) contains an R2 hydrocarbon chain chosen from C1 to C34, cyclic or acyclic, linear or branched hydrocarbon chains. Preferably, R2 denotes a linear or branched C 1 to C 18, more preferably C 1 to C 8, hydrocarbon chain, even more preferably a linear C 2 to C 4 hydrocarbon chain.

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

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, halides and organic anions, preferably from organic anions,

R ₃ , R ₄ and R ₅ are identical or different and chosen, independently of one another, from C 1 to C ₂₄ hydrocarbon chains, preferably from C ₄ to C 5, 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 R ₃ , R ₄ and R _{5 groups} can be linked together in pairs to form one or more cycles,

R _O and R ₇ are identical or different and independently selected from hydrocarbon chains to C _24, preferably C ₄ to C, it being understood that R _O and R ₇ groups may contain one or more nitrogenous groups and / or oxygenated and in particular be substituted by one or more hydroxyl group (s) and that the R _Ô and R _{7 groups} can be linked together to form a ring.

According to a particularly preferred embodiment, the group G is represented by 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, 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. According to a particularly preferred embodiment, X corresponds to the formula R-COO with R a linear or branched alkyl group , preferably linear, C1 to C24, more preferably C2 to Cis, even more preferably C2 to Cs.

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

According to a particularly preferred embodiment, the polymer according to the invention is formed from units of formula (I), ie 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).

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): in which

Ri, E and G are as defined above, the preferred variants of Ri, E and G according to formula (I) described above also being preferred variants of formula (IV).

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

It is understood that one would not depart from the invention if the polymer according to the invention was 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 departing from the invention if the polymer was obtained by polymerization of monomers different from those of formula (IV), followed by post-functionalization.

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

Ri and E are as defined above according to formula (I) and G 'represents a group of formula -R2-P in which R2 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 Q group as defined above, by reaction with a quaternization agent.

It is preferred to polymerize intermediate monomers bearing a tertiary amine function and then, in a second step, functionalize the intermediate polymer thus obtained by reacting it with a quaternization agent, rather than polymerizing monomers which have already been quaternized.

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 atoms. of carbon.

Whether one proceeds 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 process. The various polymerization techniques and conditions are widely described in the literature and fall within the general knowledge of those skilled in the art.

The polymerization is advantageously a block polymerization. The sequenced polymerization may be of the group transfer polymerization (GTP) or controlled radical polymerization type; for example, by atom transfer radical polymerization (ATRP); radical polymerization by nitroxide (NMP in English "Nitroxide-mediated polymerization"); degenerative transfer processes such as degenerative iodine transfer polymerization (ITRP-iodine transfer radical polymerization) or radical polymerization by reversible chain transfer by addition-fragmentation ( 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 activators regenerated by electron transfer (ARGET in English "activators regenerated by electron transfer ”).

The following documents WO 1998/01478, WO 1999/31144, WO2001 / 77198, WO2005 / 00319, WO2005 / 000924 may be cited by way of example of a description of RAFT radical polymerization.

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 1200 and 3000 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 : The polymer described above is used to improve the cold resistance properties of a fuel or fuel composition, in particular, of a composition chosen from gas oils, biodiesels, type B _x gas oils and fuel oils. such as in particular domestic fuel oils (FOD).

The fuel or fuel composition is as described below and advantageously comprises at least one cut of hydrocarbons obtained from one or more sources chosen from the group consisting of mineral sources, preferably petroleum, animal sources. , vegetable and synthetic.

Advantageously, the polymer according to the invention is used to improve the low-temperature flow properties of the fuel or of the fuel during its storage and / or its use at low temperature, by lowering its limit filterability 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 limit filterability temperature (TLF, measured according to standard NF EN 116). 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 the n-alkanes containing at least 12 carbon atoms, more preferably at least 20 carbon atoms. , even more preferably preferably at least 24.

According to a preferred embodiment, the polymer according to the invention is used as a TLF booster additive, that is to say in combination with at least one flow improvement additive or cold flow additive. improvers ”or CFI). The cold thinning additive (CFI) is preferably chosen from copolymers and terpolymers of ethylene and of vinyl ester (s) and / or acrylic (s), alone or as a mixture, preferably from among ethylene / vinyl acetate (EVA) copolymers and their mixtures with a terpolymer of ethylene, vinyl acetate and a other vinyl ester.

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

This effect is usually referred to as the "TLF booster" effect insofar as the presence of the polymer according to the invention improves the fluidifying nature of the CFI additive. This improvement is reflected, in particular, by a significant reduction in the TLF of the fuel composition or fuel additive with this combination compared to the same fuel or fuel composition additive only with the additive CFI, at the same treatment rate. Generally, a significant drop in TLF results in a decrease of at least 3 ° C in TLF according to standard NF EN 116.

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

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

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

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. fuel or fuel composition.

The 'additives: A subject of the invention is also a composition of additives comprising a polymer as described above, and at least one cold thinning additive (CFI) chosen from copolymers of ethylene and of 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 included in the range from 0.1: 100 to 10: 100.

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

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

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

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 of vinyl ester (s) on the other hand, is included 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%.

The additive composition may also comprise one or more several anti-sedimentation additives and / or paraffin dispersants (WASA), different from the polymer according to the invention and from 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 / (meth) acrylate copolymers of alkyl amidified with a polyamine, polyamine alkenylsuccinimides, derivatives of phthalamic acid and of double chain fatty amine; optionally grafted alkylphenol resins. Examples of such additives are given in the following documents: EP261959, EP593331, EP674689, EP327423, EP512889, EP832172;

US2005 / 0223631; US5998530; W093 / 14178.

Particularly preferred anti-sedimentation and / or paraffin dispersant additives (WASA) are chosen from alkylphenol resins and alkylphenol resins grafted, for example, with functional groups such as polyamines.

The additive composition may also include one or more other additives commonly used in fuels or fuels, other than the polymer according to the invention and cold resistance additives described above. The additive composition may typically comprise one or more other additives chosen from detergents, anti-corrosion agents, dispersants, demulsifiers, biocides, reodorants, procetane additives, friction modifiers, lubricity additives. or lubricity additives, combustion aid agents (catalytic combustion and soot promoters), antiwear agents and / or conductivity modifiers.

Among these additives, there may be mentioned in particular: a) procetane additives, in particular (but not limited to) chosen from alkyl nitrates, preferably 2-ethylhexyl nitrate, aryl peroxides, preferably peroxide benzyl, 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 obtained from vegetable oils or animal. 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 W02012 / 004300. It is also possible to advantageously use block copolymers formed from at least one polar unit and one non-polar unit, such as, for example, those described in patent application FR 1761700 in the name of the Applicant; d) lubricating 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 carboxylic acid derivatives. polycyclic. Examples of such additives are given in the following documents: EP680506, EP860494, WO98 / 04656, EP915944, FR2772783,

FR2772784. The additive composition can 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 additives present in said additive composition. A subject of the present invention is also 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 fuels, in particular those obtained from one or more sources chosen from the group consisting of mineral sources, preferably petroleum, animal, vegetable and synthetic.

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. The fuel or fuel composition:

The invention also relates to a fuel or fuel composition, comprising:

- at least one cut of hydrocarbons obtained from one or more sources chosen from the group consisting of mineral, animal, plant and synthetic sources,

- at least one polymer formed from units of formula (I), as defined above, and

The mineral sources are preferably petroleum.

The fuel or fuel composition according to the invention advantageously comprises said polymer (s) formed from units of formula (I) in a content of at least 0.0001% by weight, relative to the total weight. fuel or fuel composition.

Preferably, the content of such polymer (s) 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. weight, relative to the total weight of the fuel or fuel composition. The cold thinning additives (CLI) chosen from copolymers of ethylene and vinyl ester (s) are as described above. They are different (s) from the polymers according to the invention formed from units of formula (I).

The fuel composition preferably contains at least 20 ppm (0.002% by weight), preferably at least 50 ppm (0.005% by weight), preferably between 20 and 5000 ppm (between 0.002% and 0.5% by weight), more preferably between 50 and 1000 ppm (between 0.005% and 0.1% by weight) in total of cold thinning additive (s) chosen from copolymers of ethylene and of ester (s) vinyl (s). The composition may also 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 ethylene copolymers and vinyl ester (s). Such additives are advantageously chosen from those described above.

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

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. The fuel or fuel is preferably chosen from gas oils, biodiesels, type B _x gas oils and fuel oils, preferably domestic fuel oils (FOD).

By diesel type B _x diesel (compression engine) is meant a diesel fuel which contains x% (v / v) of esters of vegetable or animal oils (including used cooking oils) transformed by a process chemical called transesterification by reacting this oil with an alcohol to obtain fatty acid esters (EAG). With methanol and ethanol, we obtain respectively fatty acid methyl esters (FAME) and ethyl esters. fatty acids (EEAG). The letter "B" followed by a number x ranging from 0 to 100, which 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, B20, 20% of EAG and 80% of middle distillates of fossil origin etc. which do not contain oxygenated compounds, type Bx diesel fuels which contain x% (v / v) of esters of vegetable or animal oils or of fatty acids, most often methyl esters (EMHV or FAME). When the EAG is used alone in engines, the fuel is designated by the term B 100.

The fuel or fuel may also contain hydrogenated vegetable oils, known to those skilled in the art under the name HVO (standing for “hydrotreated vegetable oil”) or HDRD (standing for “hydrogenation-derived renewable diesel”). . According to a preferred embodiment, the fuel or fuel is chosen from gas oils, biodiesels, type B _x gas oils, hydrogenated vegetable oils (HVO), and mixtures thereof.

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

These additional additives can generally be present in an amount ranging from 10 to 1000 ppm (each). According to another embodiment of the invention, a method of improving the cold resistance properties of a fuel or fuel composition comprises a step of adding to said composition a polymer formed from units of formula (I ) as defined above. According to one embodiment, this method comprises the successive steps of: a) determining a composition of additive (s) suitable for the composition of the fuel or fuel to be treated as well as the rate of treatment, 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 of vinyl ester (s), different from polymers formed from units of formula (I); b) treatment of the fuel or fuel composition with the quantity determined in step a) of said composition of additive (s).

The process for improving the cold resistance properties is typically intended for a fuel or fuel composition as described above.

Step a) is carried out according to any known process and falls within common practice in the field of fuel or fuel additives. This step involves defining a characteristic representative of the cold resistance properties of the fuel or fuel, for example the low temperature flow characteristics, setting the target value (in particular a given specification relating to the cold resistance properties), then determine the improvement that is required to achieve such a target value.

For example, a specification relating to cold resistance can be a European Deep Cold specification defining, in particular, a maximum TLF according to standard NF EN 116. Determination of the quantity of additive composition (s) to be added to the Fuel or fuel composition to achieve the specification will typically be achieved by comparison with the fuel or fuel composition without said composition of additive (s).

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

The method of improving the cold resistance properties may also include an additional step after step b) of verifying the target reached and / or adjusting the rate of treatment with the composition of additive (s).

The examples below are given by way of illustration 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:

- 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:

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

A sample is taken for characterization in order to determine by NMR the number-average molar mass and the reaction conversion. 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 (ie 1% by weight of residual monomer). Two polymers PI 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 the polymer P I: 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 13 g of butanol. The mixture is heated to 60 ° C. and left under stirring at constant temperature for 12 h. The solvent is then evaporated off at reduced pressure (55 mbar) in order to recover the PI polymer formed.

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

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 13 g of butanol. The mixture is heated to 60 ° C. and left under stirring at constant temperature for 12 h. The solvent is then evaporated off at reduced pressure (55 mbar) in order to recover the polymer P2 formed.

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

The PI and P2 polymers described in Example 1 were tested as cold-resistance additives in a fuel composition G of diesel fuel type which is particularly difficult to process, and the characteristics of which are detailed in Table 1 below:

[Table 1]

The gas oil composition G was additivated 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 Additives Carburants Spéciaux, and which is an ethylene / vinyl acetate (EVA) copolymer having 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.

Additive A has been incorporated into the diesel fuel composition G at a content of 300 ppm by weight of active material relative to the total weight of the diesel fuel composition.

There was thus obtained the gas oil composition with additive Gl. This has a limit filterability temperature (TLF, standard EN 116) of -6 ° C. The performances as cold-resistance additives of each of the polymers PI and P2 of Example 1 were tested, by evaluating their ability to lower the limit filterability temperature (TFL) of the additive gas oil composition G l. Each polymer was added at a content of 3 ppm by weight (0.0003% by weight) to composition Gl, to give gas oil G2, the TLF of which was then measured, in accordance with standard EN 116.

The results obtained are shown in Table 2 below:

[Table 2]

The above results show that the use of the polymers according to the invention, even used at very low levels, leads to a very significant lowering of the TLF.

Claims

1. Use, to improve the cold resistance properties of a fuel or fuel composition, of one or more polymers comprising at least 70 mol% of units of formula (I) below: in which

Ri represents a hydrogen atom or a methyl group,

2. Use according to the preceding claim, characterized in that 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, and preferably the group E is

3. Use according to any one of the preceding claims, characterized in that the group G is represented by one of the following formulas (II) and (III): in which :

R ₂ is as defined in claim 1;

R _O and R ₇ are identical or different and independently selected from hydrocarbon chains to C _24, preferably C ₄ to C, it being understood that R _O and R ₇ groups may contain one or more nitrogenous groups and / or oxygenated and in particular be substituted by one or more hydroxyl group (s) and that the R _Ô and R _{7 groups} can be linked together to form a ring, and preferably the G group is of formula (II).

4. Use according to the preceding claim, characterized in that the group G is represented by formula (II) above, in which:

R ₂ _{denotes a linear or branched C 2} 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 each other, C 1 to C 18 _{, preferably C 1 to C 12} alkyl groups, optionally substituted by at least one hydroxyl group, it being understood that at least one of R ₃ , R ₄ and R _{5 groups} contain 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 preferably from 2 to 18, even more preferably from 2 to 8.

5. Use of a polymer according to any one of the preceding claims, for lowering the limit filterability temperature of the fuel or fuel composition measured according to standard NF EN 1 16 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 limit filterability temperature measured according to standard NF EN 116.

6. Use according to any one of the preceding claims, characterized in that said polymer is used in combination with at least one cold thinning additive, preferably chosen from copolymers and terpolymers of ethylene and of vinyl ester (s). (s) and / or acrylic (s), alone or as a mixture, preferably chosen from ethylene / vinyl acetate (EVA) copolymers and their mixtures with a terpolymer of ethylene, vinyl acetate and another vinyl ester.

7. Use according to any one of the preceding claims, characterized in that the content of polymer (s) formed from 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. Fuel or fuel composition, comprising:

- at least one cut of hydrocarbons from one or more sources chosen 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, and

9. Composition according to the preceding claim, characterized in that it contains said polymer (s) formed from units of formula (I) in a content of at least 0.0001% by weight, preferably from 0.0001 to 0.01% by weight, more preferably from 0.0002 to 0.005% by weight, and better still from 0, 0003 to 0.002% by weight, based on the total weight of the fuel or fuel composition.

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

11. Composition according to one of Claims 8 to 10, characterized that it contains at least 0.002% by weight, preferably between 0.002% and 0.5% by weight, more preferably between 0.005% and 0.1% by weight in total cold thinning additive (s) chosen from copolymers of ethylene and of vinyl ester (s).

12. An additive composition comprising a polymer as defined in one of claims 1 to 4, and at least one cold thinning additive chosen from copolymers of ethylene and of vinyl ester (s), 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 of vinyl ester (s) of on the other hand, being included in the range from 0.1: 100 to 10: 100.

13. Additive composition according to the preceding claim, characterized in that the copolymers of ethylene and of vinyl ester (s) are chosen from ethylene / vinyl acetate (EVA) copolymers, ethylene / propionate copolymers. vinyl (EVP) and terpolymers of ethylene, vinyl acetate and another vinyl ester; more preferably chosen from ethylene / vinyl acetate (EVA) copolymers and their mixtures with a terpolymer of ethylene, of vinyl acetate and of another vinyl ester, such as in particular vinyl neodecanoate.

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