Rubber composition comprising a hydrocarbon resin obtained from rubber chips

Abstract

The invention relates to a tire for a vehicle, the tread of which comprises a rubber composition based on at least one elastomer matrix comprising at least (50) phr of a butadiene copolymer, a reinforcing filler, a crosslinking system, and a hydrocarbon resin based on a fraction resulting from the pyrolysis of a feedstock comprising rubber chips, the boiling point at atmospheric pressure of said fraction being in the range of 140 to 280°C.

Description

[0001] Rubber composition comprising a hydrocarbon resin obtained from rubber chips

[0002] Technical field of the invention

[0003] The present invention relates to the field of rubber compositions, in particular rubber compositions for pneumatic tires.

[0004] Prior art

[0005] Tires, and more generally rubber products such as conveyor belts and non-pneumatic tires, are complex objects made up of a multitude of components. For example, a tire is made up of more than 200 different raw materials.

[0006] The challenges in terms of pressure on renewable and fossil resources are such that it is essential to make the most of the resources that used rubber articles represent. However, the recycling of materials from used rubber articles, such as used tires into new tires, is still limited, in particular due to the major impact of the constituents on the tire's performance. Indeed, the recycling of materials can have a negative overall environmental impact due to the degradation of the performance of tires using these materials. There is therefore a strong need for processes for recovering end-of-life rubber articles in order to produce raw materials whose use will not degrade the performance of tires, thus leading to an overall lower environmental impact.

[0007] Much research has been conducted in this area, particularly on the recovery of oils from the pyrolysis of tire waste. For example, documents EP 0928817, WO 2013 / 170358 and JP2017 / 008214 teach the production of tire-grade carbon black from the pyrolysis of tire tire chips.

[0008] Other research focuses on the recovery of intermediate products. WO 90 / 14409 focuses on the separation of pyrolysis oils from tire waste by distillation in order to recover valuable chemical compounds, particularly limonene, with the distillation being carried out in such a way as to concentrate the species of commercial interest. The article "Production of dldimonene by vacuum pyrolysis of used tires" teaches that the amount of limonene in pyrolysis oils from tire chips can be increased by adjusting the temperature of the pyrolysis step and minimizing the residence time of the vapor phase in the reactor. The document "A review of dipentene (dldimonene) production from waste tire pyrolysis" (Danon et al., Journal of Analytical and Applied Pyrolysis 112 (2015) 1-13) also deals with the production of dipentene from tire waste.None of these documents address the subsequent use of these products. The document “Thermal depolymerization and pyrolysis of cis-l,4-polyisoprene ■ preparation of liquid polyisoprene and terpene resin” (Cataldo, Journal of Analytical and Applied Pyrolysis 44(1998) 121-130) deals with the production of resins from the depolymerization product of pure isoprene, whether natural or synthetic. However, the depolymerization of tire waste leads to numerous by-products that are not present during the depolymerization of pure polyisoprene, which have a potentially deleterious effect on resin production.

[0009] Documents WO2022 / 101562 and WO2022 / 101563 describe the synthesis of resins from rubber chips that can be used in the manufacture of new tires without impacting their performance. However, these documents are silent on the specific uses of the resins produced.

[0010] Continuing its research, the applicant discovered that a vehicle tire tread comprising a rubber composition including a resin produced from rubber chips exhibits improved dry grip performance and stiffness without degrading rolling resistance performance.

[0011] Detailed description of the invention

[0012] The invention relates to at least one vehicle tire, the tread of which comprises a rubber composition based on at least one elastomeric matrix comprising at least 50 pce of a butadiene copolymer, a reinforcing filler, a crosslinking system and a hydrocarbon resin based on a cut resulting from the pyrolysis of a filler comprising rubber chips, the boiling point at atmospheric pressure of said cut being in the range from 140 to 280°C.

[0013] Preferably, the reinforcing filler comprises from 10 to 150 pce, preferably from 50 to 130 pce of silica.

[0014] Preferably, the butadiene copolymer has a glass transition temperature Tg of less than -20°C, preferably between -20°C and -110°C. Preferably, the rubber composition comprises at least 70 phr, preferably at least 90 phr of at least one butadiene copolymer, preferably a butadiene-styrene copolymer.

[0015] Preferably, the hydrocarbon resin has the following characteristics: ■

[0016] • a glass transition temperature (noted Tg) ranging from 20°C to 140°C

[0017] • a number-average molar mass less than 5000 g / mol

[0018] • a dispersity D less than 3

[0019] • An aromatic proton rate, determined by 1H NMR, between 0.5% mol and 50% mol J

[0020] • A rate of aliphatic protons, determined by 1H NMR, between 50% mol and 99.5% mol J

[0021] • 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%.

[0022] Preferably, the aromatic proton content of the hydrocarbon resin, determined by 1H NMR, is between 2 mol% and 30 mol%, preferably is between 2 mol% and 20 mol% and very preferably is between 5 mol% and 15 mol%.

[0023] Preferably, the hydrocarbon resin is obtained by a process comprising at least ■ a) A step of pyrolysis of a feedstock comprising rubber chips making it possible to obtain at least one pyrolysis oil b) A step of separation of the pyrolysis oil into at least one raffinate, an intermediate fraction and an extract, the intermediate fraction having a boiling point at atmospheric pressure in the range from 140 to 280°C and comprising at most 10% by weight of heteroatoms c) A step of synthesis of resins comprising a polymerization section fed by the intermediate fraction from step b) and producing a polymerized effluent d) A treatment step comprising a section for separation of the polymerized effluent from step c) into a solvent-rich effluent and a resin-rich effluent, and a drying section fed by the resin-rich effluent in order to produce the hydrocarbon resin.

[0024] Preferably, the rubber chips fed in step a) of the process comprise at least 50 phr of diene elastomer, preferably at least 60 phr of diene elastomer. Preferably, the intermediate fraction constituting the cut at the base of the hydrocarbon resin has a boiling point at atmospheric pressure in the range from 150 to 280°C and preferably from 150 to 260°C.

[0025] Definitions

[0026] 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.

[0027] A Cn compound means a compound containing n carbon atoms. Similarly, a Cn'Cm compound means a set of compounds containing n to m carbon atoms.

[0028] A heteroatom is an atom other than carbon or hydrogen, for example nitrogen, sulfur, oxygen.

[0029] Vehicle bandage

[0030] The present invention relates to a vehicle tire, the tread of which comprises a rubber composition based on at least one elastomeric matrix comprising at least 50 pce of a butadiene copolymer, a reinforcing filler, a crosslinking system and a hydrocarbon resin based on a cut resulting from the pyrolysis of a filler comprising rubber chips, the boiling point at atmospheric pressure of said cut being in the range from 140 to 280°C.

[0031] The vehicle tire may be a pneumatic or non-pneumatic tire. Non-pneumatic means that the tire is capable of supporting the vehicle load by means other than pressurized inflation gas, for example by means of guy wires.

[0032] 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 handling vehicle. As known to those skilled in the art, the tread is the part of the vehicle tire which circumferentially surrounds this tire and ensures contact of the tire with the rolling surface, for example the road.

[0033] Elastomer

[0034] The rubber composition of the tire according to the invention comprises at least 50 pce of a butadiene copolymer.

[0035] 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 "vinyltoluene", para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, vinylmesitylene, divinylbenzene, vinylnaphthalene. Preferably, the vinylaromatic monomer of the butadiene and vinylaromatic monomer copolymer is styrene.

[0036] Preferably, the rubber composition according to the invention comprises at least 70 phr, preferably at least 90 phr of at least one butadiene copolymer, preferably a butadiene copolymer _ styrene.

[0037] According to a particularly preferred embodiment of the invention, the butadiene copolymer has 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.

[0038] The rubber composition of the tire according to the invention may also comprise at least one other elastomer, preferably at least one other diene elastomer.

[0039] By diene type elastomer, we recall that it should be understood that an elastomer is derived at least in part (i.e. a homopolymer or a copolymer) from diene monomers (monomers carrying two carbon-carbon double bonds, conjugated or not).

[0040] 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 diene 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 in particular be described 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.

[0041] 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.

[0042] The other monomer can be ethylene, an olefin or a diene, conjugated or not.

[0043] Suitable conjugated dienes are conjugated dienes having 4 to 12 carbon atoms, in particular 1,3'-dienes, such as 1,3'-butadiene and isoprene.

[0044] Suitable olefins are vinylaromatic compounds with 8 to 20 carbon atoms and aliphatic chromoolefins with 3 to 12 carbon atoms.

[0045] Suitable vinyl aromatic compounds are, for example, styrene, ortho-, methyl-, para-methylstyrene, the commercial mixture "vinyltoluene", para-tert-butylstyrene.

[0046] Suitable aliphatic chromoolefins are, in particular, acyclic aliphatic chromoolefins having from 3 to 18 carbon atoms.

[0047] 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.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.

[0048] Hydrocarbon resin

[0049] The tread of the vehicle tire according to the invention comprises a rubber composition based on a hydrocarbon resin based on a cut resulting from the pyrolysis of a charge comprising rubber chips, the boiling point at atmospheric pressure of said cut ranging from 140 to 280°C.

[0050] A hydrocarbon resin is a resin that consists only of carbon and hydrogen atoms.

[0051] The said hydrocarbon resin has the following characteristics: ■

[0052] • a glass transition temperature (noted Tg) ranging from 20°C to 140°C

[0053] • 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

[0054] • a dispersity D of less than 3, preferably less than 2.5 and more preferably less than 2;

[0055] • A rate of aromatic protons, determined by 1H NMR, between 0.5% mol and 50% mol, preferably between 2% mol and 30% mol, preferably between 2% mol and 20% mol and very preferably between 5% mol and 15% mol

[0056] • 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 and preferably between 85% mol and 95% mol

[0057] • 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%.

[0058] Said hydrocarbon resin is based on a cut resulting from the pyrolysis of a charge comprising rubber chips, the boiling point at atmospheric pressure of said cut ranging from 140 to 280°C. The method of obtaining the resin gives it rubber composition properties different from similar resins in terms of structure. By rubber chip is meant a small element obtained by cutting rubber articles, preferably rubber articles at the end of their life. The rubber articles are preferably stripped of their non-rubber constituent elements, such as for example textile fibers or metal wires. The rubber chips preferably have a greater length ranging from 1 to 100 mm, preferably from 1 to 50 mm and most preferably from 1 to 30 mm.The chips can have any shape, but chips of relatively uniform size and shape are preferred in order to facilitate the pyrolysis stage. This control of size and shape is well known to those skilled in the art.

[0059] Preferably, the rubber chips comprise at least 50 pce of diene elastomer. By "diene" elastomer (or indistinctly rubber), whether natural or synthetic, is meant in a known manner an elastomer consisting at least in part (i.e., a homopolymer or a copolymer) of diene monomer units (monomers carrying two carbon-carbon double bonds, conjugated or not).

[0060] Preferably, the diene elastomer is chosen from the group consisting of polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), butadiene copolymers, isoprene copolymers, and blends of these elastomers. Butadiene copolymers are particularly chosen from the group consisting of butadiene-styrene copolymers (SBR).

[0061] A high content of diene elastomer promotes the production of monomers of interest at the pyrolysis outlet, in particular limonene.

[0062] Preferably, the rubber chips are obtained from tire treads, in particular from heavy goods vehicle tire treads, the latter having high contents of diene elastomers, preferably isoprene, typically 60 to 100 pce of isoprene elastomers.

[0063] The hydrocarbon resin used in the invention can be obtained by the process described below.

[0064] Pyrolysis step a) The feedstock comprising rubber chips feeds a rubber chip pyrolysis step operated at a temperature between 300 and 900°C with an increasing temperature ramp, making it possible to obtain a gaseous effluent, a pyrolysis oil and a solid effluent, said pyrolysis oil comprising at least 1.5% by weight of C Cia olefinic monomers.

[0065] The pyrolysis step is preferably carried out at a temperature between 350 and 800°C, and preferably between 350 and 650°C, a pressure of less than 1 bar and a ratio of the residence time of the solid to the residence time of the gas ranging from 10 to 240, preferably from 10 to 120 and very preferably from 10 to 60.

[0066] A short residence time of the gas fraction compared to the residence time of the solid fraction improves the yield of monomers of interest. The residence time of the gas fraction can be reduced by feeding the pyrolysis stage with an inert gas. This preferential feeding also improves the desorption of volatile matter bound to the solid fraction.

[0067] The residence time of the solid fraction in the pyrolysis step preferably ranges from 3 to 180 min, preferably from 3 to 120 min. The residence time of the gas fraction is less than 3 min.

[0068] These particular conditions make it possible to maximize the production of compounds of interest, in particular monomers such as limonene, as well as gaseous fractions that can be used as fuels and heavy liquid fractions that can be used for the production of carbon black.

[0069] In particular, the use of an increasing temperature ramp makes it possible to optimize the yield and selectivity of the pyrolysis reactions towards the monomers of interest. Preferably, the pyrolysis step is carried out with a temperature ramp of between 1 and 10°C / min.

[0070] 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. When the pyrolysis step is operated continuously or semi-continuously, it can be carried out in several zones operated at increasing temperatures so that the flow passing through these zones undergoes a temperature increase of between 1 and 10°C / min.

[0071] The pyrolysis effluent is cooled so as to condense the volatile fractions. At the end of the condensation, three effluents are obtained: ■ a gaseous effluent comprising the incondensable gases (i.e. gaseous under normal temperature and pressure conditions, namely 0°C and 1 atm), a liquid effluent referred to as "pyrolysis oil" and a solid effluent.

[0072] Pyrolysis oil consists primarily of a mixture of hydrocarbons with a wide boiling point range. Most of these compounds are members of the alkane, olefin, naphthenes (cycloalkanes), and aromatic families. Some species containing heteroatoms are also present.

[0073] The operating conditions of the pyrolysis step of the process according to the invention make it possible to obtain a pyrolysis oil comprising at least 1.5% by weight of C4'Ci2 olefinic monomers, preferably at least 2% by weight of C Cia olefinic monomers, preferably at least 4% by weight.

[0074] Olefinic monomers are hydrocarbon compounds comprising unsaturated carbon-carbon bonds and capable of polymerizing under suitable conditions. These olefinic monomers include limonene, terpenes, aromatic olefins such as styrene, alpha-methylstyrene, indene, coumarone, linear or cyclic olefins such as dicyclopentadiene.

[0075] The pyrolysis oil preferably comprises at least 70% by weight of carbon element, preferably at least 74% by weight and preferentially at least 78% by weight.

[0076] The pyrolysis oil preferably comprises at most 5% by weight of nitrogen element, preferably at most 3% by weight and preferentially at most 1.5% by weight.

[0077] The pyrolysis oil preferably comprises at most 2% by weight of sulfur element, preferably at most 1.5% by weight and preferentially at most 1% by weight.

[0078] Step b) of separation of the pyrolysis oil The process for obtaining the resin used in the invention comprises a step of separation of the pyrolysis oil into at least one raffinate, an intermediate fraction and an extract, the intermediate fraction having a boiling point at atmospheric pressure in the range from 140 to 280°C and comprising at most 10% by weight of heteroatoms.

[0079] The boiling point at atmospheric pressure can be determined in a manner known to those skilled in the art, for example by following the requirements of standard ASTM D86-23.

[0080] Extract means a lighter fraction, i.e. one with a lower final boiling point (or cut point in the terminology used in distillation) than the intermediate fraction. Raffinate means a heavier fraction, i.e. one with a higher final boiling point than the intermediate fraction.

[0081] The separation step makes it possible to eliminate from the pyrolysis oil the constituents which could be detrimental to the proper functioning of the resin synthesis step, in particular with regard to the activity of the catalyst.

[0082] Preferably, the intermediate fraction from step b) is a cut whose boiling point at atmospheric pressure is in the range from 150 to 280°C and preferably from 150 to 260°C. This cut concentrates most of the olefinic monomers of interest, while excluding most of the compounds which may have a negative impact on the resin synthesis step.

[0083] Said intermediate fraction comprises at most 10% by weight of heteroatoms. In particular, it comprises limonene and other compounds of the terpene family, such as crpinene, B-pinene, carene, myrcene, farnesene, other oxidized or non-oxidized terpenes, aromatic olefins such as styrene, alpha-methyl-styrene, indene, coumarone, linear and cyclic olefins such as dicyclopentadiene, but also compounds inert with respect to the resin synthesis step such as aliphatic and aromatic hydrocarbons.

[0084] Preferably, the intermediate fraction resulting from step b) comprises at most 2% by weight of sulfur element, preferably at most 1.5% by weight, and preferably less than 1% by weight, very preferably less than 0.8% by weight, the latter being particularly detrimental to the subsequent step of resin synthesis. The step of separating the pyrolysis oil into at least one raffinate, an intermediate fraction and an extract can be carried out by any means known to those skilled in the art making it possible to increase the concentration of C Cia olefinic monomers and to limit the heteroatom content.

[0085] In particular and preferably, separation step b) is carried out by distillation, which can be carried out sequentially (batch) or continuously, in one or more intermediate steps.

[0086] Thus, in a preferred arrangement, separation step b) is carried out by distillation, the intermediate fraction being obtained by topping followed by tailing.

[0087] Topping means the removal of a light fraction, the cutting point of which is less than 140°C, preferably less than 150°C at atmospheric pressure. Tailing means the removal of a heavy fraction, the cutting point of which is greater than 280°C, preferably greater than 260°C.

[0088] In another preferred arrangement, separation step b) is carried out in a single distillation step, the intermediate fraction being obtained by side withdrawal from said distillation step. A particularly preferred example of implementation of this arrangement is an implementation in a so-called "internal wall" column.

[0089] In the preferred case where separation step b) is carried out by distillation, this is preferably carried out at a pressure less than or equal to atmospheric pressure, preferably less than or equal to 0.5 bar, preferably less than or equal to 0.250 bar.

[0090] Preferably, the intermediate fraction from step b) undergoes a purification treatment before feeding step c).

[0091] This purification treatment makes it possible, where appropriate, in particular to lower the content of compounds such as sulfur or carbonyl compounds before the intermediate fraction feeds a step c) of resin synthesis.

[0092] Preferably, the purification treatment is carried out by passing the intermediate fraction over a fixed bed of silica, alumina, activated carbon, ion exchange resins or a mixture of these constituents. In the arrangement in which the purification treatment is carried out, the heteroatom content in the intermediate fraction at the end of the purification treatment is less than 2% by weight, preferably less than 1% by weight, preferably less than 0.9% by weight and more preferably less than 0.8% by weight.

[0093] Step c) of resin synthesis

[0094] The process for obtaining the resin used in the invention comprises a resin synthesis step comprising a polymerization section supplied at least with the intermediate fraction from step b) and with a solvent chosen from aliphatic, aromatic, halogenated solvents and their mixtures, operated in the presence of an acid catalyst, followed by a finishing section producing a polymerized effluent.

[0095] The resin synthesis step mainly consists of oligomerizing the olefinic monomers included in the intermediate fraction feeding said synthesis step, and thus preparing new resin-type oligomeric materials, 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 with a molecular weight greater than 5000 g / mol, as well as the microstructure. A dimer means a compound comprising two monomers linked by a covalent bond. A dimer may be a homodimer, i.e. the combination of two identical monomers, a heterodimer, i.e. the combination of two different monomers, or a mixture of homodimer and heterodimer. A trimer means a compound comprising three monomers linked by a covalent bond.A trimer can be a homotrimer, that is, the combination of three identical monomers, a heterotrimer, that is, the combination of at least two different monomers, or a mixture of homotrimer and heterotrimer.

[0096] Preferably, the resin obtained by the process described herein 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.

[0097] The polymerization section is operated in the absence of a catalyst, or in the presence of an acid catalyst, of the Bronsted acid or Lewis acid type, said catalyst being able to be homogeneous or heterogeneous. Preferably, said polymerization section is operated in the presence of an acid catalyst, of the Bronsted acid or Lewis acid type. Said polymerization section can also be operated in the presence of ligands, a co-catalyst, and / or a cationic polymerization initiator, for example of the proton or carbocation generator type.

[0098] 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.

[0099] Preferably, the solvent chosen from aliphatic, aromatic, halogenated solvents and their mixtures is chosen from C7-C10 aromatic solvents, C6-C8 aliphatic solvents and CLC2 chlorinated solvents and their mixtures, preferentially from toluene, methylcyclohexane and dichloromethane.

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

[0103] 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 CLC3 alcohol and their mixtures, preferably chosen from water, methanol, ethanol and their mixtures, 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.

[0104] The molar ratio of stopper compound to polymerization catalyst in the finishing section is at least 1.1, preferably at least 2.

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

[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 treated in order to recycle the stopper compound in the finishing section. The polymerized effluent then feeds the treatment stage.

[0110] Step d) treatment of the polymerized effluent

[0111] The process for obtaining the resin used in the invention comprises a step of treating the polymerized effluent from step c) comprising a section for separating a solvent-rich effluent and a resin-rich effluent, and a drying section supplied with the resin-rich effluent in order to produce the resins.

[0112] The implementation of the step of treating the polymerized effluent in the process for obtaining the resin implemented in the invention makes it possible to adjust the characteristics of the resins, in particular by eliminating the oligomers of low molecular mass (dimers, trimers, tetramers for example) and by reducing the dispersity, in order to control the properties of the resins obtained.

[0113] 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 stage, 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. In another preferred arrangement, the separation section is carried out by coagulation of the resins. In this arrangement, the polymerized effluent from step c) 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] In another preferred arrangement, the separation section is carried out by liquid-liquid extraction. In this arrangement, the polymerized effluent from step c) 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.

[0120] Liquid-liquid extraction can also be implemented upstream of a separation by distillation or by coagulation of the resins as described previously.

[0121] In another preferred arrangement, the separation section is carried out by evaporation, for example by evaporation in a wiped film evaporator.

[0122] 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 may seek to maintain a high temperature to achieve a high resin content while maintaining an effluent viscosity that allows its transport, ensuring that it remains below the temperatures at which the resins thermally degrade. 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 hydrocarbon resins have a residual solvent content (grouping together the solvent(s) used in the synthesis step as well as the solvent(s) optionally used in the separation section) of less than 3% by weight, preferably less than 1.5% by weight and preferably less than 0.8% by weight relative to the mass of resins. The dried hydrocarbon resins have a residual content of free monomers of less than 5% by weight, preferably less than 2% by weight and preferably less than 1% by weight relative to the mass of resins.

[0123] The dried hydrocarbon resins have a glass transition temperature (Tg) ranging from 20°C to 140°C, preferably from 30 to 60°C. They have a number-average molecular mass (Mn) less than or equal to 5000 g / mol, preferably less than or equal to 3000 g / mol, preferably less than 1500 g / mol. They have a centrifugation-average molecular mass (Mz) less than or equal to 10000 g / mol, preferably less than or equal to 8000 g / mol, preferably less than 6000 g / mol.

[0124] 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.

[0125] The dispersity index (noted Ip) of the dried resins is less than 3, preferably less than 2.5, preferably less than 2.

[0126] The macrostructure (mass-average, number-average, centrifugation-average molar mass and polydispersity index, respectively denoted Mw, Mn, Mz and Ip) 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.

[0127] 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.

[0128] The sample to be analyzed is simply previously solubilized in a suitable solvent, tetrahydrofuran at a concentration of 1 g / liter. Then the solution is filtered through a 0.45 pm 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.

[0129] A Moore calibration is carried out with a series of commercial polystyrene standards with low Ip (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 Ip = Mw / Mn, are deduced.

[0130] All molar mass values ​​indicated in this application are therefore relative to calibration curves produced with polystyrene standards.

[0131] Reinforcing charge

[0132] 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.

[0133] 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].

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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. To couple the reinforcing inorganic filler to the elastomer, it is possible optionally 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.

[0140] 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).

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] Crosslinking system

[0146] 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.

[0147] Sulphur is used at a rate ranging from 1 to 20 pce, preferably from 1 to 10 pce.

[0148] The vulcanization accelerator is used at a preferential rate such that the sulfur / vulcanization accelerator mass ratio is less than or equal to 4.

[0149] 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, but are not limited to, 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.

[0150] 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.

[0151] The crosslinking system may also optionally include a vulcanization retarder.

[0152] 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.

[0153] 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.

[0154] Preparation of rubber compositions

[0155] 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 mixed and where appropriate the other elastomers or fillers present in the composition which are not in the form of a masterbatch are incorporated, as well as any other various additives.

[0156] Thermomechanical mixing 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.

[0157] The possible crosslinking system will be added during the second phase. For example, a crosslinking system based on polyacids or polydienophiles will typically be added during the first phase. A crosslinking system based on peroxides or sulfur will typically be added during the second phase. The final composition thus obtained can then be calendered, for example in the form of a sheet or plate, in particular for laboratory characterization, or extruded in the form of a semi-finished rubber product (or profile).

[0158] 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.

[0159] 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.

[0160] Measurement methods

[0161] Glass transition temperature

[0162] 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.

[0163] Macrostructure (Mw, Mn, Mz and D)

[0164] 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.

[0165] 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.

[0166] The sample to be analyzed is simply previously solubilized in a suitable solvent, tetrahydrofuran at a concentration of 1 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. 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 range of masses to be analyzed. From the recorded data (molar mass distribution curve) Mw, Mn, as well as D = Mw / Mn, are deduced.

[0167] All molar mass values ​​indicated in this application are therefore relative to calibration curves produced with polystyrene standards.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] Dynamic properties

[0172] The dynamic properties G* and tan(5) 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 2section), subjected to sinusoidal stress in alternating simple shear, at a frequency of 10 Hz, under defined temperature conditions, for example at 0°C, 23°C and 100°C according to 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 complex dynamic shear modulus G* and the loss factor tan(5). For the return cycle, the maximum value of tan(5) observed and the value of G* are 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.

[0173] Examples

[0174] Synthesis of hydrocarbon resins

[0175] A rubber chip pyrolysis stage is fed with chips having an average diameter of approximately 1 mm and a density of 504 kg / m 3 , produced by crushing heavy goods vehicle tires of all sizes and brands. These chips have an isoprene elastomer content of 65% by weight.

[0176] The pyrolysis stage is carried out under an inert nitrogen atmosphere, at a temperature between 500°C and 750°C, with a solid phase residence time of 15 min. The pyrolysis stage is also supplied by a continuous flow of nitrogen.

[0177] At the reactor outlet, a gaseous effluent, a pyrolysis oil and a solid effluent are separated. The pyrolysis oil comprises approximately 2.7% by weight of limonene, 1.0% by weight of sulfur and 0.6% by weight of nitrogen. Any oxygen present is below the detection limits.

[0178] The pyrolysis oil feeds a separation stage comprising two distillation columns. The first distillation is carried out at atmospheric pressure and without reflux with a reboiler temperature of 290°C. The extract, withdrawn at the top of the column, feeds a second distillation carried out at atmospheric pressure with a reboiler temperature of 155°C and a reflux ratio, defined as the ratio of the mass flow rate of reflux returned to the top of the second column to the mass flow rate of extract withdrawn at the top of this column, of 2.7. A raffinate is withdrawn comprising the monomers of interest, and in particular limonene, styrene and indene.

[0179] This raffinate is passed over a bed of alumina balls in order to remove polar impurities, and in particular benzothiazole.

[0180] The olefinic monomer content in the treated raffinate is approximately 9.4% by weight, including 5.6% by weight of limonene, 1.5% by weight of styrene and 0.7% by weight of indene.

[0181] A first synthesis of hydrocarbon resin is carried out in the following manner : 5 kg of treated raffinate are introduced into a 101 reactor and heated to 70°C under a nitrogen atmosphere. Aluminum chloride (4 mol% relative to the limonene, styrene and indene monomer content) is introduced into the reactor under an inert atmosphere. The reactor is kept under an inert atmosphere throughout the reaction.

[0182] The medium is stirred and operated at a temperature of 70°C for 1 hour 30 minutes. The reaction is then stopped by adding water.

[0183] The reaction medium is then transferred into a 35 l reactor containing 10 kg of water at room temperature with vigorous stirring for 15 min. The medium is allowed to settle and then the organic phase is recovered.

[0184] This is then dried in an oven at 200°C for 91 hours under a pressure of 100 mbar. A resin is recovered in the form of a translucent orange solid. This resin constitutes resin "la".

[0185] A second synthesis of hydrocarbon resin is carried out, from the same treated raffinate, in the following manner ■

[0186] 5 kg of treated raffinate are introduced into a 101 reactor and heated to 70°C under a nitrogen atmosphere. Aluminum chloride (4 mol% relative to the limonene, styrene and indene monomer content) is introduced into the reactor under an inert atmosphere. The reactor is kept under an inert atmosphere throughout the reaction.

[0187] The medium is stirred and operated at a temperature of 70°C for 1 hour 30 minutes. The reaction is then stopped by adding water.

[0188] The reaction medium is then transferred into a 35 l reactor containing 10 kg of a 0.5 N aqueous hydrochloric acid solution, at room temperature with vigorous stirring for 15 min. The medium is allowed to settle and then the organic phase is recovered.

[0189] This is then dried in an oven at 200°C for 91 hours under a pressure of 100 mbar. A resin is recovered in the form of a translucent orange solid. This resin constitutes resin “1b”.

[0190] The resins obtained have the characteristics presented below: [Table 1]

[0191] Table 2 shows a commercial hydrocarbon resin. Resin Tl is a bio-sourced resin derived from the polymerization of limonene, whose commercial reference is “Dercolyte L120” from the company DRT.

[0192] [Table 2]

[0193] Rubber compositions Rubber compositions are manufactured with the introduction of all the constituents on an internal mixer, with the exception of the vulcanization system. The vulcanizing agents (sulfur and accelerator) are introduced on 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.

[0194] Table 3 shows different rubber compositions using the resins presented in Tables 1 and 2 as well as some of their properties.

[0195] [Table 3]

[0196] Table 3 References

[0197] (la) SBR of Tg = -88 °C as described in the examples of WO2017 / 168099

[0198] (lb) SBR of Tg = -48°C as described in the examples of WO2015 / 185394

[0199] (2) Carbon black, grade ASTM N234

[0200] (3) Silica, “Zeosil 1165 MP” from Solvay, type HDS

[0201] (4) N-(l,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine ("Santoflex 6 _ Flexsys' PPD and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)

[0202] (5) Coupling agent ■ “Si69” from Evonik — Degussa

[0203] (6) Diphenylguanidine, “Perkacit DPG” from Flexsys

[0204] (7) Stearin, “Pristerene 4931” from Uniqema

[0205] (8) Zinc oxide, industrial grade — Umicore

[0206] (9) N-Cyclohexyl-2-benzothiazolesulfenamide (“Santocure CBS” from Flexsys)

[0207] The results are expressed in base 100, the value of 100 being assigned, for each composition typology, to the control (CTI and CT2). 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.

[0208] Compared to compositions based on a bio-sourced polylimonene resin, it is observed that the compositions in accordance with the invention exhibit improved performance in terms of grip on dry ground and G* stiffness, for similar rolling resistance. These performance differences are particularly interesting for a vehicle tire tread.

Claims

CLAIMS

1. Vehicle tire, the tread of which comprises a rubber composition based on at least one elastomeric matrix comprising at least 50 pce of a butadiene copolymer, a reinforcing filler, a crosslinking system and a hydrocarbon resin based on a cut resulting from the pyrolysis of a filler comprising rubber chips, the boiling point at atmospheric pressure of said cut being in the range from 140 to 280°C.

2. Bandage according to the preceding claim in which the reinforcing filler comprises from 10 to 150 pce, preferably from 50 to 130 pce of silica.

3. A bandage according to any one of the preceding claims in which the butadiene copolymer has a glass transition temperature Tg of less than -20°C, preferably between -20°C and -110°C.

4. A tire according to any preceding claim wherein the rubber composition comprises at least 70 phr, preferably at least 90 phr of at least one butadiene copolymer, preferably a butadiene copolymer _ styrene.

5. A bandage according to any preceding claim wherein the hydrocarbon resin has 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%.

6. Bandage according to the preceding claim in which the rate of aromatic protons of the hydrocarbon resin, determined by 1H NMR, is between 2 mol% and 30 mol%, preferably is between 2 mol% and 20 mol% and very preferably is between 5 mol% and 15 mol%.

7. A tire according to any one of the preceding claims, in which the hydrocarbon resin is obtained by a process comprising at least ■ a) A step of pyrolysis of a filler comprising rubber chips making it possible to obtain at least one pyrolysis oil b) A step of separation of the pyrolysis oil into at least one raffinate, an intermediate fraction and an extract, the intermediate fraction having a boiling point at atmospheric pressure in the range from 140 to 280°C and comprising at most 10% by weight of heteroatoms c) A step of synthesis of resins comprising a polymerization section fed by the intermediate fraction from step b) and producing a polymerized effluent d) A treatment step comprising a section for separation of the polymerized effluent from step c) into a solvent-rich effluent and a resin-rich effluent,and a drying section fed by the resin-rich effluent to produce the hydrocarbon resin.,

8. Tire according to the preceding claim in which the rubber chips fed in step a) of the process comprise at least 50 pce of diene elastomer, preferably at least 60 pce of diene elastomer.

9. A bandage according to any one of the preceding claims, in which the intermediate fraction constituting the cut at the base of the hydrocarbon resin has a boiling point at atmospheric pressure in the range from 150 to 280°C and preferably from 150 to 260°C.

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