Hydrocarbon resin from bio-based and / or recycled materials, and rubber composition comprising said hydrocarbon resin

Abstract

The invention relates to a hydrocarbon resin based on an aromatic distillation fraction obtained from the pyrolysis of a styrene feedstock, followed by its separation into a styrene-rich stream comprising at least 99% by weight of styrene, and on a bio-based aliphatic stream.

Description

[0001] HYDROCARBON RESIN DERIVED FROM BIOSOURCED AND / OR RECYCLED MATERIALS AND RUBBER COMPOSITION COMPRISING THIS HYDROCARBON RESIN

[0002] Technical field of the invention

[0003] The present invention relates to the field of hydrocarbon resins, rubber compositions comprising such resins, as well as vehicle tires comprising such rubber compositions.

[0004] Prior art

[0005] It is known from the prior art that elastomers with a low glass transition temperature ("Tg") allow an improvement in terms of abrasion performance (WO 2015 / 043902) and are therefore very useful when seeking to obtain the best compromise between performance properties that are difficult to reconcile simultaneously, such as wear resistance and grip, which must be high, and rolling resistance, which must be low in order to minimize fuel consumption.

[0006] These low Tg elastomers exhibit poor compatibility with hydrocarbon-based plasticizing resins typically used in vehicle tires.

[0007] However, the compatibility of resins with the elastomeric matrix, and in particular their ability to disperse correctly in the mixture, is essential for them to play their role correctly. The compatibility of the resin with an elastomeric matrix depends, among other things, on properties such as the glass transition temperature and the softening point of the resin, these properties being dependent on the molar mass, the nature and the ratio of aromatic units to aliphatic units of the resin (see for example J. Appl Polym. Sci 2022 139(15) 51950). Resins comprising aliphatic and aromatic units and having high Tg make it possible, in particular, to modify the Tg of the mixture.

[0008] Such resins are well known in the state of the art. For example, document EP 0 936 229 teaches the manufacture of hydrocarbon resins from aliphatic and aromatic monomers in cationic polymerization, from petroleum-based streams. Documents WO2016 / 043851, US9139721 or FR2968006 describe hydrocarbon resins with high Tg. Document FR 3 099 166 describes a tire comprising a rubber composition comprising a specific hydrocarbon resin derived from petroleum fractions having improved road behavior at different temperatures. While the performance of tires such as rolling resistance and wear resistance are key to limiting their environmental impact, it is also important to limit the use of fossil resources as much as possible when manufacturing rubber articles.

[0009] WO2022 / 101562 and WO2022 / 101563 describe the production of hydrocarbon resins from residues from the pyrolysis of rubber chips. These documents do not address the impact of these resins on the performance of rubber compositions.

[0010] Continuing its research, the applicant discovered that a resin derived from bio-sourced and / or recycled resources made it possible to maintain, or even improve, key performances of rubber compositions usable in vehicle tires, thus being able to advantageously replace petroleum-sourced hydrocarbon resins.

[0011] Detailed description of the invention

[0012] The invention relates to a hydrocarbon resin based on an aromatic distillation cut originating from the pyrolysis of a styrenic feedstock and then its separation into a styrene-rich stream comprising at least 99% by mass of styrene and an aliphatic stream of biosourced origin, said resin having the following characteristics: ■

[0013] • a glass transition temperature (noted Tg) ranging from 20°C to 140°C

[0014] • a number-average molar mass less than 5000 g / mol

[0015] • a dispersity D less than 3

[0016] • An aromatic proton rate, determined by 1H NMR, between 0.5% mol and 50% mol J

[0017] • A rate of aliphatic protons, determined by 1H NMR, between 50% mol and 99.5% mol J

[0018] • A rate of ethylenic protons, determined by 1H NMR, less than or equal to 10%mol The sum of the rates of aromatic, aliphatic and ethylenic protons being equal to 100%.

[0019] Preferably, the rate of aromatic protons, determined by 1H NMR, is between 2 mol% and 30 mol% and preferably is between 2 mol% and 20 mol%.

[0020] Preferably, the feedstock of styrenic compounds comprises at least 90% by weight of polystyrene, preferably at least 93% by weight of polystyrene, and preferably at least 95% by weight of polystyrene. Preferably, the hydrocarbon resin according to the invention is obtained by a process comprising at least ■ a. A step of preparing the feedstock of styrenic compounds so as to be able to feed this feedstock into the pyrolysis step; b. A step of pyrolysis of the feedstock of styrenic compounds making it possible to obtain at least one gaseous effluent and one pyrolysis oil, said gaseous effluent comprising at least 20% by weight of aromatic compounds c. A step of separating the gaseous effluent into at least one styrene-rich stream comprising at least 99% by weight of styrene d.A resin synthesis step comprising a polymerization section fed by the styrene-rich stream from step c) and by a stream of aliphatic compounds comprising at least 5% by weight of terpene compounds of biosourced origin, followed by a finishing section and producing a polymerized effluent e. A treatment step comprising a section for separating the polymerized effluent from step d) into a solvent-rich effluent and a resin-rich effluent, and a drying section fed by the resin-rich effluent in order to produce a stream of hydrocarbon resins.

[0021] The invention also relates to a rubber composition based on at least one elastomer and one hydrocarbon resin according to the invention.

[0022] The rubber composition according to the invention preferably comprises a reinforcing filler and a crosslinking system.

[0023] The rubber composition according to the invention preferably comprises from 10 to 150 pce, preferably from 50 to 130 pce of silica.

[0024] The elastomer of the rubber composition according to the invention is preferably a diene elastomer.

[0025] The rubber composition according to the invention preferably comprises mainly a diene elastomer having a glass transition temperature Tg of less than -20°C, preferably between -20°C and -110°C.

[0026] The rubber composition according to the invention comprises at least 60 phr, preferably at least 70 phr, more preferably at least 80 phr of at least one diene elastomer chosen from the group consisting of polybutadiene, butadiene copolymers and mixtures of these elastomers.

[0027] Preferably, the butadiene copolymer is a butadiene-styrene copolymer.

[0028] The invention also relates to a vehicle tire comprising a rubber composition according to the invention or a resin according to the invention.

[0029] The vehicle tire according to the invention preferably comprises a tread comprising a hydrocarbon resin according to the invention or a rubber composition according to the invention.

[0030] Definitions

[0031] The carbon-containing compounds mentioned in the description may be of fossil or bio-sourced origin. In the latter case, they may be, partially or totally, derived from biomass or obtained from renewable raw materials derived from biomass. This includes, in particular, polymers, plasticizers, fillers, etc.

[0032] The term "composition based on" means a composition comprising the mixture and / or the product of the in situ reaction of the different basic constituents used, some of these constituents being able to react and / or being intended to react with each other, at least partially, during the different phases of manufacture of the composition or during the subsequent curing, which may modify the composition as initially prepared. Therefore, the compositions described below may be different in the uncrosslinked state and in the crosslinked state.

[0033] Unless expressly stated otherwise, all percentages (%) given are percentages by weight ("wt. %). Furthermore, any range of values ​​referred to as "between a and b" represents the range of values ​​extending from more than a to less than b (i.e., the limits a and b are excluded), while any range of values ​​referred to as "from a to b" represents the range of values ​​extending from a to b (i.e., including the strict limits a and b). A Cn compound means a compound comprising n carbon atoms. Similarly, a Cn'Cm compound means a set of compounds comprising from n to m carbon atoms.

[0034] A heteroatom is an atom other than carbon or hydrogen, for example nitrogen, sulfur, oxygen.

[0035] A compound is said to be predominant when it represents more than 50% by weight of compounds of the same nature. Thus, a predominant elastomer is an elastomer which represents more than 50% by weight compared to the total weight of the elastomers present.

[0036] Hydrocarbon resin

[0037] The present invention relates to a hydrocarbon resin obtained from a charge of styrenic compounds and a flow of aliphatic compounds of biosourced origin, said resin having the following characteristics ■

[0038] • a glass transition temperature (noted Tg) ranging from 20°C to 140°C

[0039] • a number-average molar mass of less than 5000 g / mol, preferably less than 4000 g / mol and more preferably less than 3000 g / mol

[0040] • a dispersity D of less than 3, preferably less than 2.5 and more preferably less than 2;

[0041] • A rate of aromatic protons, determined by 1H NMR, between 0.5% mol and 50% mol, preferably between 2% mol and 30% mol and more preferably between 2% mol and 20% mol

[0042] • A level of aliphatic protons, determined by 1H NMR, between 50% mol and 99.5% mol, preferably between 70% mol and 98% mol, preferably between 80% mol and 98% mol

[0043] • A level of ethylenic protons, determined by 1H NMR, less than or equal to 10 mol%, preferably less than or equal to 5 mol%, preferably less than or equal to 4 mol%, the sum of the levels of aromatic, aliphatic and ethylenic protons being equal to 100%. Preferably, the level of ethylenic protons, determined by 1H NMR, is greater than or equal to 0.5 mol%, preferably greater than or equal to 1 mol%.

[0044] The hydrocarbon resin according to the invention is based on an aromatic distillation cut originating from the pyrolysis of a styrenic feedstock and then its separation into a styrene-rich stream comprising at least 99% by mass of styrene and an aliphatic stream of biosourced origin. By styrenic compound feedstock is meant a feedstock which comprises styrene-based polymers, such as styrenic rubbers and polystyrene.

[0045] Preferably, the filler of styrenic compounds is a filler of styrenic compounds derived from plastic waste. Such a filler preferably comprises at least 90% by weight of polystyrene, preferably at least 93% by weight of polystyrene, and more preferably at least 95% by weight of polystyrene. The filler of styrenic compounds may comprise other compounds, in particular if it is derived from plastic waste. These other compounds may be, in a non-limiting manner, plastic compounds such as polyethylene, polypropylene, elastomers, organic materials such as paper, food, or inorganic materials such as glass, metal, sand.

[0046] The flow of aliphatic compounds comprises at least 5% by weight of terpenic compounds, of bio-sourced origin.

[0047] The stream of aliphatic compounds is of bio-sourced origin. That is, it comes from biomass or is derived from biomass products.

[0048] By derived from biomass, it is meant that the compounds are derived, after possible treatment, from plant, animal, fungal or microbe organisms. Preferably, the stream of aliphatic compounds is derived from plant organisms. By derived from products derived from biomass, it is meant that the biomass used to obtain the stream of aliphatic compounds may have undergone a treatment such as a biological treatment, based for example on the functioning of plants, animals, or microorganisms, a chemical treatment, such as for example a treatment in the presence of acid, an alkali treatment, in the presence or absence of a catalyst, and / or a physical treatment such as pressurization, a heat treatment, an electromagnetic treatment or a microwave treatment.

[0049] Obtaining the resin

[0050] The hydrocarbon resin according to the invention can be obtained by the process described below.

[0051] Step a) of preparation

[0052] The charge of styrenic compounds is conditioned in a preparation step a) to be able to feed the pyrolysis step b). This preparation step may include grinding, degassing and heating operations in order to cause the plastic compounds to melt, for example in an extrusion device during which the temperature is gradually increased, the vapor effluents (water, light compounds generated by the partial decomposition of the polystyrene charge) and the solid effluents (non-fusible debris such as metal debris, glass) are separated.

[0053] Preferably, the charge of styrenic compounds is gradually heated to a temperature between 100°C and 300°C, preferably between 150°C and 300°C and more preferably between 200°C and 300°C, this temperature making it possible to obtain the melting of the polystyrene, when such a compound is present, by limiting its thermal decomposition.

[0054] Step b) of pyrolysis

[0055] The charge of styrenic compounds feeds a pyrolysis step making it possible to obtain at least one gaseous effluent and one pyrolysis oil, said pyrolysis oil comprising at least 20% by weight of aromatic compounds.

[0056] Pyrolysis means the thermal decomposition of compounds in an inert atmosphere.

[0057] The feedstock is fed to a pyrolysis step, carried out at a temperature and pressure such that the depolymerization of the styrenic compounds into styrene oligomers and styrene monomer takes place. Preferably, the pyrolysis step is carried out at a temperature ranging from 300 to 900°C, preferably from 300°C to 800°C.

[0058] The pyrolysis step is preferably carried out at a pressure ranging from 0.8 bar to 7.5 bar, preferably ranging from 1 bar to 6 bar and more preferably ranging from 1 bar to 4.5 bar.

[0059] Preferably, the pyrolysis step implements a microwave pyrolysis step. Such microwave pyrolysis usable for the pyrolysis of a charge of styrenic compounds is for example described in document WO 2020 / 202089.

[0060] The use of a microwave-assisted pyrolysis step allows for higher heat transfer rates and reaction temperatures, which promote end-of-pipe scission reactions and minimize the formation of styrene oligomers. A microwave pyrolysis step is also characterized by a lower temperature in the reaction mass than a conventional pyrolysis section. The lower temperatures in the reaction mass result in lower evaporation rates of styrene oligomers and help avoid over-cracking the styrene product. The use of a microwave pyrolysis step will reduce the formation of styrene oligomers compared to a conventional pyrolysis step. The pyrolysis step produces at least an off-gas and a pyrolysis oil. The off-gas may also contain entrained liquid droplets.Besides styrene oligomers, the off-gas comprises the majority of the styrene monomer produced in the pyrolysis step, as well as gaseous light aromatic compounds under operating conditions such as alpha-methylstyrene, ethylbenzene, cumene and toluene.

[0061] The gaseous effluent comprises at least 20% by weight of aromatic compounds, preferably at least 20% by weight of styrene.

[0062] Preferably, the gaseous effluent comprises at most 10% by weight of ethylbenzene, preferably at most 5% by weight of ethylbenzene and preferably at most 3% by weight of ethylbenzene.

[0063] Preferably, the gaseous effluent comprises at least 10% by weight of compounds whose boiling point is higher than that of styrene.

[0064] The pyrolysis oil may also comprise solid elements, unfused polymers, produced during pyrolysis, or debris not separated in the feedstock preparation step. This flow preferably feeds a separation section in which the possible solid fraction is separated from the liquid fraction, the latter being able to be recycled in a mixture with the feed of the pyrolysis step or used in step d) of resin synthesis.

[0065] The pyrolysis step can be carried out in a pyrolysis reactor, and can be operated continuously, semi-continuously or in batch processing. Such reactors are well known to those skilled in the art.

[0066] Step c) separation

[0067] A separation step c) is fed at least with the gaseous effluent from step b) and produces at least one stream rich in light compounds, one stream rich in styrene and one stream rich in heavy compounds.

[0068] The light-rich stream consists mainly of compounds lighter than styrene, particularly toluene and ethylbenzene. The light-rich stream is a T100°C-140°C cut, preferably a T110 cut. o C _ 140 o C. By "Cup Ta°Cb°C" is meant that the bubble point and the dew point of the cup, measured at atmospheric pressure, are included in the temperature range from a°C to b°C. The stream rich in light compounds therefore has a bubble point and a dew point measured at atmospheric pressure included in the temperature range from 100 to 140°C, preferably from 110 to 140°C.

[0069] Preferably, the cumulative content of toluene and ethylbenzene in the stream rich in light compounds is at least equal to 60% by mass, preferably is at least equal to 70% by mass, and preferably is at least equal to 75% by mass.

[0070] The styrene-rich stream mainly comprises aromatic compounds comprising from 6 to 9 carbon atoms. The separation step c) is carried out in such a way that the styrene-rich stream comprises at least 99% by mass of styrene and that the styrene recovery rate, i.e. the ratio of the styrene flow rate in the aromatic-rich stream to the styrene flow rate in the gaseous effluent from step b) is at least equal to 90%, preferably at least equal to 95% and more preferably at least equal to 97%.

[0071] Preferably, the stream rich in aromatic compounds is a T140°C-150°C cut, preferably a T144°C-146°C cut.

[0072] The stream rich in heavy compounds mainly comprises compounds heavier than styrene, as well as non-depolymerized styrenic compounds, and in particular styrene oligomers when the feed includes polystyrene.

[0073] The flow rich in heavy compounds is a T150°C-220°C cut, preferably a T160°C-210°C cut.

[0074] Preferably, the alpha-methylstyrene content in the stream rich in heavy compounds is at least equal to 60% by mass, preferably is at least equal to 70% by mass, preferably is at least equal to 80% by mass and very preferably is at least equal to 90% by mass.

[0075] Preferably, separation step c) is carried out by distillation.

[0076] In a first variant of this preferred arrangement, a first column fed with the gaseous effluent from step b) separates this effluent into a stream rich in light compounds and a raffinate, the latter being separated by means of a second column into a stream rich in styrene and a stream rich in heavy compounds.

[0077] In a second variant of this preferred arrangement, the separation is carried out in a single distillation column. In this variant, at the top of the column, the vapor effluent is cooled to a temperature between 30°C and 50°C, preferably between 35°C and 45°C. The condensed liquid fraction is returned to the top of the column as reflux, while the vapor fraction is then subcooled to a temperature between -5°C and 10°C, preferably between -5°C and 5°C in order to condense any styrene entrained with the light compounds. The condensed stream after subcooling is returned to the top of the column as reflux. The residual vapor fraction constitutes the stream rich in light compounds. This stream can then be recovered, for example in the form of energy.A first cooling allows to use as much of the cooling water at ambient temperature as cold utility and minimizes the use of specific cold utility to obtain subcooling, which has a favorable impact on the life cycle analysis of the process.

[0078] In this variant, the distillation column is operated at a pressure of between 0.1 and 2.0 bara, preferably between 0.5 and 1.5 bara and more preferably between 0.5 and 1.1 bar, the operating pressure being understood as the pressure measured at the top of the column. By "bara" is meant absolute bar, as opposed to a pressure expressed in relative bar, commonly noted "barg" according to the English notation "bar gauge".

[0079] In this variant and preferably, the distillation column is fed at the bottom of the column with at least the gaseous effluent from step b) and produces at the top of the column a flow rich in light compounds, at the bottom a flow rich in heavy compounds, and by a lateral withdrawal a flow rich in styrene, said column having as its only heat input said gaseous effluent from step b).

[0080] The gaseous effluent from step b) is at a high temperature, preferably at a temperature above 300°C. This temperature is sufficient so that the column does not require any further heat input.

[0081] By feeding the feedstock at the bottom of the column, the feedstock is rapidly cooled, thus limiting any potential styrene polymerization reactions. This feedstock also allows for better management of so-called heavy compounds. Indeed, the absence of a recirculation system at the bottom of the column, usually used to maintain the distillation column at the correct temperature, greatly limits the risk of fouling by so-called heavy compounds, which are particularly viscous.

[0082] The distillation column implemented in this variant of step c) of the process comprises from 5 to 20 theoretical stages, preferably at most 15 theoretical stages, preferably from 8 to 12 theoretical stages.

[0083] A styrene-rich stream is withdrawn onto an intermediate tray. This withdrawal tray is located in the lower third of the distillation column, preferably 1 to 3 theoretical stages from the bottom tray. This withdrawal at a low position in the column, slightly removed from the bottom tray, limits the entrainment of heavy compounds into the styrene-rich stream and thus limits the risk of fouling subsequent equipment.

[0084] Preferably, and in order to further limit the risk of polymerization, a styrene polymerization inhibitor to polystyrene, such as 2,2,6,6 _ tetramethyl-4-oxopiperidinooxy, may be fed into the distillation column of step c), or the distillation columns of step c) of the process, preferably at the column head.

[0085] Toluene and ethylbenzene type compounds, which do not react in step d) of resin synthesis, can be used as solvent in this synthesis step, which makes it possible to avoid the addition of a solvent of external origin to the process.

[0086] Step d) of resin synthesis

[0087] A step d) of resin synthesis comprising a polymerization section is fed by the styrene-rich stream from step c) and by a stream of aliphatic compounds comprising at least 5% by weight of terpene compounds of biosourced origin, followed by a finishing section and producing a polymerized effluent.

[0088] The resin synthesis step mainly consists of oligomerizing the monomers included in the styrene-rich stream from step c), in particular styrene and alpha-methylstyrene, and the stream of aliphatic compounds comprising at least 5% by weight of terpene compounds of biosourced origin, and thus of preparing new oligomeric materials of the resin type, by controlling the macrostructure, in particular by limiting the content of low molecular weight compounds, such as monomers, dimers and trimers, and high molecular weight compounds, i.e. those whose molecular weight is greater than 5000 g / mol, as well as the microstructure. By dimer is meant a compound comprising two monomers linked by a covalent bond. A dimer can be a homodimer, that is, the combination of two identical monomers, a heterodimer, that is, the combination of two different monomers, or a mixture of homodimer and heterodimer.A trimer is a compound comprising three monomers linked by a covalent bond. A trimer can be a homotrimer, i.e., the combination of three identical monomers, a heterotrimer, i.e., the combination of at least two different monomers, or a mixture of homotrimer and heterotrimer.

[0089] By terpene compounds of biosourced origin, we mean compounds of the terpene family which are unsaturated hydrocarbons of plant origin. The terpene compounds useful for the purposes of the invention are preferably chosen from terpenes comprising at most 20 carbon atoms, preferably chosen from the compounds limonene, alpha-pinene, beta-pinene, myrcene, farnesene and their mixtures, preferably chosen from the compounds limonene, alpha-pinene, beta-pinene and their mixtures and preferably are limonene.

[0090] Limonene is a terpene hydrocarbon that can be obtained, in particular, from citrus peels or by microbial fermentation.

[0091] By feeding the resin synthesis step with the aromatic-rich stream from step c) and a stream of aliphatic compounds, the ratio of aromatic and aliphatic units in the resin produced can be controlled and thus the resin can be adapted to the polymer matrix in which this resin is intended to be incorporated. This allows a resin with excellent compatibility to be obtained from renewable and / or recycled resources.

[0092] Thus, the process allows the styrene-rich stream to be used according to the desired parameters for the resin produced, which allows for great versatility. Preferably, when the styrene-rich stream is produced by distillation in step c), no further treatment is required before using this stream for resin production.

[0093] Preferably, the mass ratio of the flow from step c) to the flow of aliphatic compounds feeding step d) is adjusted to regulate the proportion of aliphatic and aromatic protons in the resin.

[0094] Preferably, the polymerization section is also supplied with a stream of solvent chosen from aliphatic, aromatic, halogenated solvents and their mixtures. Preferably, the solvent chosen from aliphatic, aromatic, halogenated solvents and their mixtures is chosen from C7-C10 aromatic solvents, C6 aliphatic solvents _ C8 and CPC2 chlorinated solvents and their mixtures, preferably among toluene, methylcyclohexane and dichloromethane.

[0095] Preferably, a fraction of the pyrolysis oil from step b) is used as a solvent stream. Preferably, the process is fed only with the feedstock of styrenic compounds and the stream of aliphatic compounds comprising at least 5% by weight of terpene compounds of biosourced origin, the solvent required in step d) being provided by at least one stream from step c) and / or at least one fraction of the pyrolysis oil from step b), preferably at least one fraction of the pyrolysis oil from step b) feeding step d).

[0096] Preferably, synthesis step d) is fed by the flow from step c) and by a flow of aliphatic compounds comprising at least 5% by weight of terpene compounds and by a flow of solvent such that the monomer content is between 50 and 75% by weight. Thus, the solvent flow rate can be adapted so as to adjust the monomer content in step d). This content makes it possible to limit the exothermicity within step d), while making it possible to obtain a polymerized effluent whose viscosity allows it to be conveyed to the downstream steps of the process.

[0097] Preferably, the resin obtained by the process comprises less than 1% by weight of compounds whose molecular mass is greater than 5000 g / mol. Preferably, the resin obtained comprises at most 50% by weight of dimeric and trimeric compounds.

[0098] The polymerization section is operated in the absence of a catalyst, or in the presence of an acid catalyst, such as a Bronsted acid, Lewis acid or Friedel-Crafts acid, said catalyst being able to be homogeneous or heterogeneous. Preferably, said polymerization section is operated in the presence of an acid catalyst, such as a Bronsted acid or Lewis acid. Said polymerization section can also be operated in the presence of ligands, a cocatalyst, and / or a cationic polymerization initiator, for example of the proton or carbocation generator type.

[0099] Preferably, the catalyst is a Lewis acid comprising ligands from the aluminum halide family. Preferably, these ligands are chosen from aluminum chlorides, for example aluminum trichloride, alkylaluminum chlorides, such as diethylaluminum chloride and ethylaluminum dichloride, and arylaluminum chlorides, such as phenylaluminum chloride. Preferably, the catalyst also comprises a co-ligand with Lewis base character, making it possible to modulate the acid character of the Lewis acid ligand, of the aliphatic ether type (for example diethyl ether, dibutyl ether), aromatic ether (diphenyl ether), or ester (ethyl acetate) or alkyl amines (triethylamine) or arylamines (diphenylamine, triphenylamine). The polymerization section can also be operated with ligands containing phosphorus, sulfur or any other heteroatom.

[0100] The polymerization section is preferably operated at a temperature ranging from -60°C to +300°C, preferably ranging from -60°C to +120°C, very preferably ranging from -50°C to +100°C and preferably ranging from -40°C to +90°C and very preferably ranging from +20 to +90°C.

[0101] The average residence time in the polymerization section is preferably between 0.25 h and 7 h, preferably between 0.5 h and 4 h. When the polymerization section is operated continuously, the average residence time in said section is the ratio of the reaction volume of said section to the volume flow rate of the feeds of the section.

[0102] The quantity of catalyst, including possible ligands and co-ligands, is preferably within a range from 0.05% to 5% by weight relative to the weight of olefinic monomers entering the polymerization section, and preferably ranges from 0.1% to 2% by weight relative to the weight of olefinic monomers entering the polymerization section.

[0103] The stream from the polymerization section is then treated in a finishing section producing a polymerized effluent.

[0104] This finishing section makes it possible to stop the polymerization reaction by the addition of a compound which deactivates the catalyst and stops the chains still growing. The finishing section is preferably implemented by contacting with a flow comprising a stopper compound chosen from water, a C1-C3 alcohol and their mixtures, preferably chosen from water, methanol, ethanol and their mixture, very preferably water at a temperature between 5 and 80°C, preferably at a temperature between 15 and 30°C (for example at room temperature), followed by separation by phase decantation of a polymerized effluent and an effluent mainly comprising the stopper compound. The molar ratio of stopper compound to polymerization catalyst in the finishing section is at least equal to 1.1, preferably at least equal to 2.

[0105] When the stopper compound is water, the volume ratio of reaction medium to water in the finishing section is preferably between 20 : l and 10 : l, preferably between 10 : l and 5 : 1 and preferably between 5 : 1 and LL

[0106] The flow from the polymerization section and the flow comprising the stopper compound are brought into contact with stirring for a period preferably ranging from 5 min to 2 h, preferably ranging from 15 min to 45 min, in order to promote contact between the stopper compound and the reaction medium.

[0107] At the end of this agitation phase, a decantation phase is carried out in order to separate on the one hand an organic phase constituting the polymerized effluent containing mainly the resins, the solvent, the unconverted monomers, dimers, trimers and oligomers of low molecular weight and a phase containing mainly the stopper compound, the catalytic residues and organic residues soluble in the stopper compound.

[0108] The decantation phase is preferably carried out for a period ranging from 5 min to 4 h, preferably ranging from 15 min to 2 h.

[0109] The phase containing mainly the stopper compound can then be processed in order to recycle the stopper compound in the finishing section.

[0110] The polymerized effluent then feeds the treatment stage.

[0111] Step e) treatment of the polymerized effluent

[0112] The method comprises a step of treating the polymerized effluent from step d) comprising a section for separating a solvent-rich effluent and a resin-rich effluent, and a drying section fed with the resin-rich effluent in order to produce the resins.

[0113] The implementation of the polymerized effluent treatment step in the process makes it possible to adjust the characteristics of the resins, in particular by eliminating low molecular weight oligomers (e.g. dimers, trimers, tetramers) and by reducing the dispersity, in order to control the properties of the resins obtained (e.g. glass transition temperature). The separation section of a solvent-rich effluent and a resin-rich effluent makes it possible, on the one hand, to recover a majority of the solvent and unconverted monomers for subsequent use, preferably for recycling in the resin synthesis step of the process, and, on the other hand, to concentrate the resins in the resin-rich effluent.

[0114] The separation section can be carried out by any method known to those skilled in the art, in particular and preferably by evaporation, distillation, coagulation of resins, liquid-liquid extraction or a combination of these methods.

[0115] In a preferred arrangement, the separation section is carried out by distillation in at least one distillation column so as to produce a solvent-rich effluent at the top and a resin-rich effluent at the bottom. This section makes it possible to eliminate the residual monomers and oligomers at the top as well as the majority of the solvent used in the resin synthesis step and thus to adjust the macrostructure of the resins as well as its properties, for example the glass transition temperature noted Tg, in particular by reducing the dispersity by eliminating the low molecular weight compounds. The resin-rich effluent comprises the majority of the resins feeding the separation section. The resin recovery rate, corresponding to the ratio of the resin flow rate in the resin-rich effluent to the resin flow rate in the feed of the separation section, is preferably greater than 80%, more preferably greater than 90%.This recovery rate can be adjusted by increasing the number of separation stages in the separation section, or by adjusting the operating parameters of said section, for example the reflux rate.

[0116] In another preferred arrangement, the separation section is carried out by coagulation of the resins. In this arrangement, the polymerized effluent from step d) is brought into contact with a coagulation solvent in which the resins are not soluble in order to precipitate them. The coagulation solvent solubilizes the residual monomers, the solvent used in the resin synthesis step and the low molecular weight oligomers.

[0117] The coagulation solvent is preferably chosen from polar protic or aprotic solvents with a low boiling point such as alcohols, for example methanol, ethanol and isopropanol, acetone, ethers, for example tetrahydrofuran (denoted THF) and dioxane.

[0118] The coagulation separation section is preferably operated with a coagulation solvent / medium to be coagulated volume ratio ranging from L1 to 10 : l, preferably ranging from 2:1 to 5:1. The coagulation separation section is preferably operated at a temperature ranging from 5°C to 40°C.

[0119] The stream comprising the coagulation solvent, constituting the solvent-rich effluent, can then be recycled, for example to the resin synthesis stage, undergoing a purification treatment stage beforehand, if necessary.

[0120] In another preferred arrangement, the separation section is carried out by liquid-liquid extraction. In this arrangement, the polymerized effluent from step d) is washed with a stream comprising mainly water. This extraction can be carried out in one or more stages, preferably in one to three stages.

[0121] Liquid-liquid extraction can also be implemented upstream of a separation by distillation or by coagulation of the resins as described previously.

[0122] In another preferred arrangement, the separation section is carried out by evaporation, for example by evaporation in a wiped film evaporator.

[0123] The viscosity of the resin-rich effluent depends on the resin content in the effluent and its temperature. These contents and temperatures are therefore adjusted so that the effluent can be transported to the drying section. One can seek to maintain a high temperature to achieve a high resin content while maintaining an effluent viscosity that allows its transport, while ensuring that it remains below the temperatures at which the resins thermally degrade.

[0124] The resin-rich effluent then feeds a drying section in which it is filtered and then dried. At the end of the drying step, the dried resins have a residual solvent content (grouping together the solvent(s) used in the synthesis step as well as the solvent(s) possibly used in the separation section) of less than 3% by weight, preferably less than 1.5% by weight and more preferably less than 0.8% by weight relative to the mass of resins. The dried resins have a residual content of free monomers of less than 5% by weight, preferably less than 2% by weight and more preferably less than 1% by weight relative to the mass of resins.

[0125] The content of the hydrocarbon resin in the rubber composition may be in a range of 15 phr to 150 phr, 25 phr to 120 phr, 40 phr to 115 phr, 50 phr to 110 phr, and 65 phr to 110 phr. Below 15 phr of the present hydrocarbon resin, the effect of the present hydrocarbon resin becomes insufficient and the rubber composition may have adhesion problems. Above 150 phr, the composition may have manufacturing difficulties in terms of easy incorporation of the present hydrocarbon resin into the composition.

[0126] Rubber composition

[0127] The present invention also relates to a rubber composition based on at least one elastomer and a hydrocarbon resin according to the invention. Said rubber composition may further comprise various optional components, well known to those skilled in the art. Some of them are also described below.

[0128] Elastomer

[0129] The rubber composition according to the invention comprises at least one elastomer, preferably diene. By diene type elastomer, it is recalled that it must be understood an elastomer which is derived at least in part (i.e. a homopolymer or a copolymer) from oak monomers (monomers carrying two carbon-carbon double bonds, conjugated or not).

[0130] These diene elastomers can be classified into two categories: ■ "essentially unsaturated" or "essentially saturated". "Essentially unsaturated" generally means a diene elastomer derived at least in part from conjugated oak monomers, having a content of units or patterns of diene origin (conjugated dienes) which is greater than 15% (mol %); thus, diene elastomers such as butyl rubbers or copolymers of dienes and alpha-olefins such as EPDM do not fall within the preceding definition and can be described in particular as "essentially saturated" diene elastomers (low or very low content of patterns of diene origin, always less than 15% (mol %)). The diene elastomers included in the rubber composition according to the invention are preferably essentially unsaturated.

[0131] The term “diene elastomer” which may be used in the rubber compositions in accordance with the invention is understood in particular to mean: ■ a) any homopolymer of a diene monomer, conjugated or not, having from 4 to 18 carbon atoms; b) any copolymer of a diene, conjugated or not, having from 4 to 18 carbon atoms and at least one other monomer.

[0132] The other monomer may be ethylene, an olefin or a diene, conjugated or not. Suitable conjugated dienes are conjugated dienes having 4 to 12 carbon atoms, in particular 1,3-dienes, such as 1,3-butadiene and isoprene.

[0133] Suitable olefins are vinylaromatic compounds with 8 to 20 carbon atoms and aliphatic carbon monoolefins with 3 to 12 carbon atoms.

[0134] Suitable vinyl aromatic compounds are, for example, styrene, ortho-, methyl-, para-methylstyrene, the commercial mixture "vinyl-toluene", para-tert-butylstyrene.

[0135] Suitable aliphatic chromoolefins are, in particular, acyclic aliphatic chromoolefins having from 3 to 18 carbon atoms.

[0136] The diene elastomer is preferably a diene elastomer of the highly unsaturated type, in particular a diene elastomer selected from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR), polybutadienes (BR), butadiene copolymers, isoprene copolymers and mixtures of these elastomers. Such copolymers are more preferably selected from the group consisting of butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR), isoprene-butadiene-styrene copolymers (SBIR), ethylene-butadiene copolymers (EBR) and mixtures of such copolymers.

[0137] The above diene elastomers can be, for example, block, random, sequenced, microsequenced, and can be prepared in dispersion or in solution; they can be coupled and / or star-shaped or even functionalized with a coupling and / or star-shaped or functionalizing agent, for example epoxidized.

[0138] By "isoprene elastomer" is meant a homopolymer or a copolymer of isoprene, in other words a diene elastomer chosen from the group consisting of natural rubber (NR) which can be plasticized or peptized, synthetic polyisoprenes (IR), the various copolymers of isoprene, in particular copolymers of isoprene-styrene (SIR), isoprene-butadiene (BIR) or isoprene-butadiene-styrene (SBIR), and mixtures of these elastomers.

[0139] According to a particularly preferred embodiment of the invention, the elastomer is a diene elastomer having a glass transition temperature Tg of less than -20°C, preferably between -20°C and -110°C, more preferably between -60°C and -110°C, more preferably between -60°C and -90°C. Such elastomers are known to those skilled in the art and described for example in documents WO2015 / 185394 and WO2017 / 168099.

[0140] Preferably, the predominant diene elastomer is selected from the group consisting of polybutadiene, butadiene copolymers and blends of these elastomers, and more preferably from the group consisting of polybutadiene, butadiene and styrene copolymers and blends of these elastomers.

[0141] The butadiene copolymer is preferably a copolymer of butadiene and a vinylaromatic monomer. Suitable vinylaromatic compounds are, for example, styrene, ortho-, meta-, para-methylstyrene, the commercial mixture "vinyl-toluene", para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, vinylmesitylene, divinylbenzene, vinylnaphthalene. Preferably, the vinylaromatic monomer of the butadiene and vinylaromatic monomer copolymer is styrene.

[0142] According to this embodiment, the predominant elastomer, preferably diene, having a very low Tg, is present in the composition at a content preferably greater than or equal to 60 phr, more preferably greater than or equal to 70 phr and even more preferably greater than or equal to 80 phr. More preferably, the composition comprises 100 phr of elastomer having a very low Tg as defined above.

[0143] Reinforcing charge

[0144] The rubber composition according to the invention preferably comprises a reinforcing filler. Any type of reinforcing filler known for its ability to reinforce an elastomeric composition suitable for the manufacture of pneumatic tires may be used, for example an organic filler such as carbon black, a reinforcing inorganic filler such as silica, or a blend of these two types of filler, in particular a blend of carbon black and silica.

[0145] Suitable carbon blacks are all carbon blacks, in particular HAF, ISAF, SAF type blacks conventionally used in tires (so-called tire grade blacks). Among the latter, mention will be made more particularly of reinforcing carbon blacks of the 100, 200 or 300 series (ASTM grades), such as for example blacks NI 15, N134, N234, N326, N330, N339, N347, N375, or even, depending on the intended applications, blacks of higher series (for example N660, N683, N772). The carbon blacks could for example already be incorporated into an isoprene elastomer in the form of a masterbatch (see for example applications WO 97 / 36724 or WO 99 / 16600). The BET specific surface area of ​​carbon blacks is measured according to standard D6556-10 [multi-point method (minimum 5 points) — gas: nitrogen - relative pressure range P / PO: 0.1 to 0.3].

[0146] By "reinforcing inorganic filler" is meant in the present application, by definition, any inorganic or mineral filler (whatever its color and its natural or synthetic origin), also called "white" filler, "light" filler or even "non-black filler" as opposed to carbon black, capable of reinforcing on its own, without any other means than an intermediate coupling agent, a rubber composition intended for the manufacture of pneumatic tires, in other words capable of replacing, in its reinforcing function, a conventional pneumatic grade carbon black. Such a filler is generally characterized, in a known manner, by the presence of hydroxyl groups (-OH) on its surface.

[0147] Suitable reinforcing inorganic fillers are, in particular, mineral fillers of the siliceous type, in particular silica (SiOa), or of the aluminous type, in particular alumina (AI2O3). The silica used may be any reinforcing silica known to those skilled in the art, in particular any precipitated or pyrogenic silica having a BET surface area and a CTAB specific surface area both of less than 450 m 2 / g, preferably 30 to 400 m 2 / g. Examples of highly dispersible precipitated silicas (known as "HDS") include "Ultrasil 7000" and "Ultrasil 7005" silicas from Degussa, "Zeosil 1165MP", "1135MP" and "1115MP" silicas from Rhodia, "Hi-Sil EZ150G" silica from PPG, "Zeopol 8715", "8745" and "8755" silicas from Huber, and high specific surface silicas as described in application WO 03 / 16837.

[0148] The physical state in which the reinforcing inorganic filler is present is irrelevant, whether in the form of powder, microbeads, granules, beads or any other suitable densified form. Of course, the term reinforcing inorganic filler also means mixtures of different reinforcing inorganic fillers, in particular highly dispersible siliceous and / or aluminous fillers.

[0149] The reinforcing inorganic filler used, particularly if it is silica, preferably has a BET surface area of ​​between 45 and 400 m 2 / g, more preferably between 60 and 300 m 2 / g.

[0150] Preferably, the rubber composition according to the invention comprises from 1 to 100 phr, more preferably from 1 to 80 phr and more preferably from 1 to 60 phr of carbon black, the optimum being in a known manner different depending on the particular applications targeted ■ the level of reinforcement expected on a bicycle tire, for example, is of course lower than that required on a tire capable of rolling at high speed in a sustained manner, for example a motorcycle tire, a tire for a passenger vehicle or for a utility vehicle such as a heavy goods vehicle. In a preferred arrangement, the reinforcing filler mainly comprises carbon black, and preferably consists of carbon black.

[0151] Preferably, the rubber composition according to the invention comprises from 10 to 150 phr, preferably from 50 to 130 phr of silica. In a preferred arrangement, the reinforcing filler mainly comprises silica and preferably consists of silica.

[0152] To couple the reinforcing inorganic filler to the elastomer, it is optionally possible to use in a known manner an at least bifunctional coupling agent (or bonding agent) intended to ensure a sufficient connection, of a chemical and / or physical nature, between the inorganic filler (surface of its particles) and the elastomer, in particular organosilanes, or bifunctional polyorganosiloxanes.

[0153] In particular, polysulfurized silanes, called "symmetrical" or "asymmetrical" depending on their particular structure, may be used, as described for example in applications W003 / 002648 (or US 2005 / 016651) and W003 / 002649 (or US 2005 / 016650).

[0154] Examples of polysulfurized silanes include polysulfides (particularly disulfides, trisulfides or tetrasulfides) of bis-(alkoxyl(Cl-C4)-alkyl(Cl _ C4)silyl-alkyl(Cl _ C4)), such as bis(3) polysulfides _ trimethoxysilylpropyl) or bis(3 _ triethoxysilylpropyl). Among these compounds, bis(3) tetrasulfide is used in particular _ triethoxysilylpropyl), abbreviated TESPT, of formula [(C2H5O)3Si(CH2)3S2]2 or bis-(triethoxysilylpropyl) disulfide, abbreviated TESPD, of formula [(C2H5O)3Si(CH2)3S]2. Also mentioned as preferred examples are polysulfides (in particular disulfides, trisulfides or tetrasulfides) of bis-(monoalkoxyl(Cl-C4)-dialkyl(Cl _ C4)silylpropyl), more particularly bis-monoethoxydimethylsilylpropyl tetrasulfide as described in patent application US 2004 / 132880.

[0155] As coupling agent other than polysulfurized alkoxysilane, mention will be made in particular of bifunctional POS (polyorganosiloxanes) or hydroxysilane polysulfides as described in patent applications WO 02 / 30939 and WO 02 / 31041, or silanes or POS bearing azodicarbonyl functional groups, as described for example in patent applications WO 2006 / 125532, WO 2006 / 125533, WO 2006 / 125534. In the rubber compositions in accordance with the invention, the content of coupling agent is preferably in a range from 5 to 18% by weight relative to the quantity of silica, preferably in a range from 8 to 12% by weight relative to the quantity of silica.

[0156] A person skilled in the art will understand that, as a filler equivalent to the reinforcing inorganic filler described in this paragraph, a reinforcing filler of another nature, in particular organic, could be used, provided that this reinforcing filler is covered with an inorganic layer such as silica, or else comprises functional sites on its surface, in particular hydroxyl sites, making it possible to establish the bond between the filler and the elastomer in the presence or absence of a covering or coupling agent.

[0157] Crosslinking system

[0158] The rubber composition according to the invention comprises a sulfur-based crosslinking system comprising a metal oxide, a stearic acid derivative and a vulcanization accelerator. This is then referred to as a vulcanization system. The sulfur can be provided in any form, in particular in the form of molecular sulfur, or a sulfur donor agent.

[0159] Sulphur is used at a rate ranging from 1 to 20 pce, preferably from 1 to 10 pce.

[0160] The vulcanization accelerator is used at a preferential rate such that the sulfur / vulcanization accelerator mass ratio is less than or equal to 4.

[0161] Any compound capable of acting as an accelerator for the vulcanization of diene elastomers in the presence of sulfur may be used as an accelerator, in particular accelerators of the thiazole type and their derivatives, accelerators of the sulfenamide, thiuram, dithiocarbamate, dithiophosphate, thiourea and xanthate types. Examples of such accelerators include the following compounds: 2-mercaptobenzothiazyl disulfide (abbreviated as "MBTS"), N-cyclohexyl-2-benzothiazyl sulfenamide ("CBS"), N,N-dicyclohexyl-2-benzothiazyl sulfenamide ("DCBS"), N-tert-butyl-2-benzothiazyl sulfenamide ("TBBS"), N-tert-butyl-2-benzothiazyl sulfenimide ("TBSI"), tetrabenzylthiuram disulfide ("TBZTD"), zinc dibenzyldithiocarbamate ("ZBEC") and mixtures of these compounds. The mass ratio of metal oxide to stearic acid derivative in the crosslinking system is less than 4, and preferably less than 3.The metal oxide is preferably zinc oxide.

[0162] The crosslinking system may also optionally include a vulcanization retarder.

[0163] The rubber compositions may preferably comprise additives commonly used in elastomeric compositions particularly intended for the manufacture of vehicle tires, such as, for example, pigments, protective agents, such as antiozonant waxes, chemical antiozonants or antioxidants, plasticizing agents other than those described above, antifatigue agents, reinforcing resins, or acceptors (for example, a phenolic novolak resin) or donors (for example, HMT or H3M) of methylene.

[0164] The rubber compositions may further comprise a plasticizer system. This plasticizer system may be composed of a hydrocarbon-based resin having a Tg greater than 20°C, in addition to the specific hydrocarbon resin described above, and / or a plasticizer oil.

[0165] Preparation of rubber compositions

[0166] The rubber composition in accordance with the invention is manufactured in suitable mixers, using preparation phases well known to those skilled in the art ■ a thermomechanical working or mixing phase, which can be carried out in a single thermomechanical step during which all the necessary constituents, in particular the elastomeric matrix, the hydrocarbon resin, the fillers, and any other various additives, are introduced into a suitable mixer such as a conventional internal mixer (for example of the 'Banbury' type). The incorporation of the filler into the elastomer can be carried out in one or more stages by thermomechanically mixing.In the case where the filler, in particular carbon black or silica, is already incorporated in whole or in part into the elastomer in the form of a masterbatch as described for example in applications WO 97 / 36724 or WO 99 / 16600, it is the masterbatch which is directly kneaded and where appropriate the other elastomers or fillers present in the composition which are not in the form of a masterbatch, as well as any other various additives, are incorporated. The thermomechanical kneading is carried out at high temperature, up to a maximum temperature of between 110°C and 200°C, preferably between 130°C and 185°C, for a duration generally of between 2 and 10 minutes.a second phase of mechanical work is then carried out in an external mixer such as a roller mixer, after cooling the mixture obtained during the first phase to a lower temperature, typically below 120°C, for example between 40°C and 100°C.

[0167] The possible crosslinking system will be added during the second phase. For example, a polyacid or polydienophile crosslinking system will typically be added during the first phase. A peroxide or sulfur crosslinking system will typically be added during the second phase.

[0168] The final composition thus obtained can then be calendered, for example in the form of a sheet or plate, in particular for characterization in the laboratory, or even extruded in the form of a semi-finished (or profile) rubber.

[0169] The composition can be either in the raw state (before crosslinking or vulcanization), or in the cooked state (after crosslinking or vulcanization), can be a semi-finished product which can be used in a tire.

[0170] The curing can be carried out, in a manner known to those skilled in the art, at a temperature generally between 130°C and 200°C, under pressure, for a sufficient time which can vary for example between 5 and 90 min depending in particular on the curing temperature, the crosslinking system adopted, the crosslinking kinetics of the composition considered or even the size of the tire.

[0171] Vehicle bandage

[0172] The present invention also relates to vehicle tires comprising a rubber composition based on at least one elastomer and a hydrocarbon resin according to the invention.

[0173] The vehicle tire may be a pneumatic or non-pneumatic tire. By non-pneumatic, it is meant that this tire is capable of supporting the load of the vehicle by a means other than a pressurized inflation gas, for example by means of stays. The vehicle tire according to the invention will be chosen from, without limitation, tires intended to equip a two-wheeled vehicle, a passenger vehicle, a “heavy load” vehicle (i.e., a subway, a bus, off-road vehicles, heavy load transport vehicles, such as trucks, tractors or trailers), an aircraft, construction equipment, a heavy agricultural vehicle or a material handling vehicle.

[0174] Preferably, the pneumatic tire according to the invention comprises a tread comprising a rubber composition according to the invention or a hydrocarbon resin according to the invention. In a manner known to those skilled in the art, the tread is the part of the pneumatic tire which circumferentially surrounds this tire and ensures contact with the rolling surface.

[0175] Description of figures

[0176] [Fig 1] Figure 1 represents a schematic view of the method according to the invention.

[0177] A charge of styrenic compounds (1) feeds a step a) of preparing the charge of styrenic compounds so as to be able to feed (2) this charge in the step b) of pyrolysis. Step b) of pyrolysis of the charge of styrenic compounds makes it possible to obtain at least one gaseous effluent (3) and one pyrolysis oil (4), said gaseous effluent (3) comprising at least 20% by weight of aromatic compounds.

[0178] The gaseous effluent (3) is then treated in a separation step c) in which it is separated into at least one styrene-rich stream (5) comprising at least 99% by weight of styrene.

[0179] The flow (5) feeds a step d) of resin synthesis comprising a polymerization section also fed at least by a flow (6) of aliphatic compounds comprising at least 5% by weight of terpene compounds of biosourced origin, and optionally by a flow of solvent (7), the polymerization section being followed by a finishing section producing a polymerized effluent (8).

[0180] The polymerized effluent (8) feeds a treatment step e) comprising a section for separating the polymerized effluent (8) from step d) into a solvent-rich effluent (9) and a resin-rich effluent, and a drying section fed by the resin-rich effluent in order to produce a stream of hydrocarbon resins (10).

[0181] Measurement methods

[0182] Glass transition temperature The glass transition temperature Tg is measured in a known manner by differential scanning calorimetry, or DSC (Differential Scanning Calorimetry), for example and unless otherwise specified, according to ISO 11357'2 of 2014.

[0183] Macrostructure (Mw, Mn, Mz and D)

[0184] The macrostructure (mass-average, number-average, centrifugation average molar mass and polydispersity index, respectively denoted Mw, Mn, Mz and D) is determined by size exclusion chromatography (SEC) as shown below. Mz reflects the thermodynamic equilibrium between sedimentation and diffusion and depends on its size. This higher-order average is used as an indication of the proportion of high molar masses present in the sample.

[0185] As a reminder, SEC analysis, for example, consists of separating macromolecules in solution according to their size through columns filled with a porous gel; the molecules are separated according to their hydrodynamic volume, the largest being eluted first.

[0186] The sample to be analyzed is simply previously solubilized in a suitable solvent, tetrahydrofuran at a concentration of 1.5 g / liter. Then the solution is filtered through a 0.45 μm porosity filter, before injection into the apparatus at a flow rate of 1 ml / min and a temperature of 35°C. The apparatus used is, for example, a "Waters Alliance" chromatographic chain.

[0187] A Moore calibration is carried out with a series of commercial standards of low-D polystyrene (less than 1.2), of known molar masses, covering the mass range to be analyzed. From the recorded data (molar mass distribution curve) Mw, Mn, as well as D = Mw / Mn, are deduced.

[0188] All molar mass values ​​indicated in this application are therefore relative to calibration curves produced with polystyrene standards.

[0189] The molar distribution of aliphatic, ethylenic and aromatic protons is measured using a spectrometer, here a Brucker AVANCE III 400 MHz spectrometer and is expressed as raw peak area ratios. The solvent used is CDC13 (deuterated chloroform) at 25°C and 120 scans.

[0190] Hydrocarbon resin NMR data are measured by dissolving 20 ± 1 mg of sample in 0.7 mL of solvents. Samples are dissolved in a 5 mm NMR tube at 25 °C until the sample is dissolved. CDCl3 appears as a peak at 7.20 ppm and is used as a reference peak for the samples. 1H NMR signals for aromatic protons are located between 8.5 ppm and 6.2 ppm. Ethylene protons lead to signals between 6.2 ppm and 4.5 ppm. Finally, signals corresponding to aliphatic protons are located between 4.5 ppm and 0 ppm. Signals corresponding to solvent, water, and other possible impurities are subtracted when integrating the resin signals.

[0191] The areas of each category of protons are reported to the sum of these areas to give a distribution in % of area of ​​each category of protons.

[0192] Dynamic properties

[0193] The dynamic properties of tan(5) at 23°C and 100°C are measured on a viscoanalyzer (Metravib VA4000), according to ASTM D 5992-96. The response of a sample of crosslinked composition (cylindrical specimen 4 mm thick and 400 mm 2 section), subjected to sinusoidal stress in alternating simple shear, at a frequency of 10 Hz, under the defined temperature conditions, at 23°C and 100°C, according to standard ASTM D 1349-99. A strain amplitude sweep is carried out from 0.1 to 50% (forward cycle), then from 50% to 1% (return cycle). The results used are the loss factor tan(5). For the return cycle, the maximum value of tan(5) observed is indicated. The value of tan(5) measured at 100°C is an indicator of grip on dry ground. A high value denotes improved grip. The value of tan(5) measured at 23°C is an indicator of rolling resistance. A low value denotes lower rolling resistance.

[0194] The dynamic property tan(5) at 0°C is measured on a viscoanalyzer (Metravib V A4000), according to ASTM D 5992 - 96. The response of a crosslinked composition sample (cylindrical specimen 4 mm thick and 10 mm in diameter), subjected to sinusoidal stress in alternating simple shear, at a frequency of 10 Hz, during a temperature sweep from -80°C to +100°C with a ramp of +1.5°C / min, under a maximum stress of 0.7 MPa, is recorded. The value of the tangent of the loss angle (Tan delta) is then recorded at 0°C. The value of tan(5) measured at 0°C is an indicator of wet grip. A high value denotes improved grip.

[0195] Tensile tests

[0196] The tests were carried out in accordance with French standard NF T 46-002 of September 1988. All tensile measurements were carried out under normal temperature (23±2°C) and hygrometry (50±5% relative humidity) conditions, according to French standard NF T 40-101 (December 1979).

[0197] The breaking stresses (in MPa) and the elongations at break (AR in %) are measured at 23°C ± 2°C, according to standard NF T 46-002, on samples cooked for 40 minutes at 150°C. The breaking energy is equal to the product of the breaking elongation and the breaking stress.

[0198] Examples of resins

[0199] A charge of styrenic compounds (1), here polystyrene, feeds a preparation step a), here an extruder, in which it is heated to a temperature of 250°C. The liquid part of the charge (2) feeds a pyrolysis step b), here a microwave pyrolysis, carried out at a temperature of 340°C and at a pressure of 1.1 bar. The gaseous effluent (3) from the pyrolysis step is separated by distillation in a separation step c) into a stream rich in light compounds (4), a stream rich in styrene (5) comprising 99.2% by weight of styrene and a stream rich in heavy compounds (6).

[0200] The styrene-rich stream (5) of 99% by weight styrene feeds a resin synthesis step. This step is also fed by a bio-sourced limonene stream comprising 99% by weight limonene and a toluene stream. The toluene stream flow rate is such that the monomer concentration (styrene + limonene) is 30% by weight at the reactor inlet.

[0201] Aluminum chloride (1.5 mol% relative to the limonene and styrene monomer content) is introduced into the reactor under an inert atmosphere. The reactor is then kept under an inert atmosphere throughout the reaction. The medium is stirred and operated at a temperature of 25°C for 1 h. The reaction is then stopped by adding water.

[0202] The reaction medium, constituting the polymerized effluent, is separated into a solvent-rich effluent and a resin-rich effluent by coagulation of the resins with water. The resin-rich effluent is then dried in an oven at 150°C for 48 h. A resin is recovered in the form of an orange translucent solid.

[0203] These steps are reproduced by varying the mass ratio of the limonene stream to the styrene-rich stream at the inlet of the resin synthesis step, the other parameters remaining unchanged. The resins obtained have the characteristics presented below ■

[0204] [Table 1]

[0205] Table 2 presents commercial hydrocarbon resins. Resin T1 is a bio-based resin derived from the polymerization of limonene, "Dercolyte L120" from DRT. Resin T2 is a resin derived from the polymerization of dicyclopentadiene (DCPD) of petro-sourced origin, whose trade name is "Escorez 5600" from Exxon.

[0206] [Table 2]

[0207] Examples of rubber compositions Rubber compositions are manufactured by introducing all the constituents into an internal mixer, with the exception of the vulcanization system. The vulcanizing agents (sulfur and accelerator) are introduced into an external mixer at low temperature (the rollers constituting the mixer being at 30°C). The compositions are cured under pressure at 150°C for 40 minutes.

[0208] Table 3 shows different rubber compositions using the resins presented in Tables 1 and 2 as well as some of their properties.

[0209] [Table 3]

[0210] Table 3 References

[0211] (1) SBR of Tg = -88 °C as described in the examples of WO2017 / 168099

[0212] (2) Carbon black, grade ASTM N234 (3) Silica, “Zeosil 1165 MP” from Solvay, type HDS

[0213] (4) N-(l,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine ("Santoflex 6 _ Flexsys' PPD and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)

[0214] (5) Coupling agent ■ “Si69” from Evonik — Degussa

[0215] (6) Diphenylguanidine, “Perkacit DPG” from Flexsys (7) Stearin, “Pristerene 4931” from Uniqema

[0216] (8) Zinc oxide, industrial grade — Umicore

[0217] (9) N-Cyclohexyl-2-benzothiazolesulfenamide (“Santocure CBS” from Flexsys)

[0218] The results are expressed on a base of 100, with the value of 100 being assigned to the CTI control. A value greater than 100 indicates that the value of the corresponding property is greater than that of the control. A value less than 100 indicates that the value of the corresponding property is less than that of the control. Compared with compositions based on a petro-sourced hydrocarbon resin or based on a bio-sourced polylimonene resin, it is observed that the compositions in accordance with the invention exhibit similar performances in terms of grip on dry and wet ground, similar rolling resistance and improved breaking energy.

Claims

CLAIMS

1. Hydrocarbon resin based on an aromatic distillation cut originating from the pyrolysis of a styrenic feedstock and then its separation into a styrene-rich stream comprising at least 99% by mass of styrene and an aliphatic stream of biosourced origin, said resin having the following characteristics: ■ • a glass transition temperature (noted Tg) ranging from 20°C to 140°C; • a number-average molar mass less than 5000 g / mol • a dispersity D less than 3 • An aromatic proton rate, determined by 1H NMR, between 0.5% mol and 50% mol • A rate of aliphatic protons, determined by 1H NMR, between 50% mol and 99.5% mol • A rate of ethylenic protons, determined by 1H NMR, less than or equal to 10% mol The sum of the aromatic, aliphatic and ethylenic proton rates being equal to 100%.

2. Hydrocarbon resin according to the preceding claim in which the level of aromatic protons, determined by 1H NMR, is between 2 mol% and 30 mol% and preferably is between 2 mol% and 20 mol%.

3. A hydrocarbon resin according to any preceding claim, wherein the styrenic compound filler comprises at least 90% by weight of polystyrene, preferably at least 93% by weight of polystyrene, and most preferably at least 95% by weight of polystyrene.

4. Hydrocarbon resin according to any one of the preceding claims obtained by a process comprising at least ■ a. A step of preparing the charge of styrenic compounds so as to be able to feed this charge into the pyrolysis step; b. A step of pyrolysis of the feedstock of styrenic compounds making it possible to obtain at least one gaseous effluent and one pyrolysis oil, said gaseous effluent comprising at least 20% by weight of aromatic compounds c. A step of separation of the gaseous effluent into at least one styrene-rich stream comprising at least 99% by weight of styrene d. A step of synthesis of resins comprising a polymerization section supplied with the styrene-rich stream from step c) and with a stream of aliphatic compounds comprising at least 5% by weight of terpene compounds of biosourced origin, followed by a finishing section and producing a polymerized effluent e. A treatment step comprising a section for separation of the polymerized effluent from step d) into a solvent-rich effluent and a resin-rich effluent, and a drying section supplied with the resin-rich effluent in order to produce a stream of hydrocarbon resins.

5. Rubber composition based on at least one elastomer and one hydrocarbon resin according to any one of the preceding claims.

6. Rubber composition according to the preceding claim comprising a reinforcing filler and a crosslinking system.

7. Rubber composition according to any one of claims 5 to 6 comprising from 10 to 150 phr, preferably from 50 to 130 phr of silica.

8. A rubber composition according to any one of claims 5 to 7 wherein the elastomer is a diene elastomer.

9. Rubber composition according to any one of claims 5 to 8 in which the elastomer predominantly comprises a diene elastomer having a glass transition temperature Tg of less than -20°C, preferably between -20°C and -110°C.

10. Rubber composition according to any one of claims 5 to 9 comprising at least 60 phr, preferably at least 70 phr, more preferably at least 80 phr of at least one diene elastomer chosen from the group consisting of polybutadiene, butadiene copolymers and mixtures of these elastomers.

11. A rubber composition according to the preceding claim wherein the butadiene copolymer is a butadiene-styrene copolymer.

12. A vehicle tire comprising a rubber composition according to any one of claims 5 to 11 or a resin according to any one of claims 1 to 4.

13. A vehicle tire according to the preceding claim, wherein the tread comprises a hydrocarbon resin according to any one of claims 1 to 4 or a rubber composition according to any one of claims 5 to 11.

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