Rubber composition comprising a hydrocarbon oil based on a pyrolysis fraction

Abstract

The invention relates to a rubber composition based on at least one elastomeric matrix comprising at least one elastomer, a reinforcing filler, a crosslinking system and a hydrocarbon oil consisting of a cut resulting from the pyrolysis of a filler comprising mainly polyethylene.

Description

Title of the invention: Rubber composition comprising a hydrocarbon oil based on a fraction obtained by pyrolysis. Technical field of the invention

[0001] The present invention relates to the field of rubber compositions, in particular rubber compositions for pneumatic tires. Previous art

[0002] Pneumatic tires, and more generally rubber articles such as conveyor belts and non-pneumatic tires, are complex objects made up of a multitude of components. For example, a pneumatic tire is made up of more than 200 different raw materials.

[0003] While some raw materials such as natural rubber are derived from renewable resources, many components of pneumatic tires are still obtained from fossil resources. It is therefore crucial to minimize the use of these resources by using bio-based materials or by recycling used materials.

[0004] However, the recycling of materials, for example from used rubber or plastic articles, is still limited, particularly due to the significant impact of the constituents on tire performance. Indeed, recycling materials can have a negative overall environmental impact due to the degradation of the performance of tires using these materials.

[0005] Much research has been conducted in the field of product recycling for use in tires, particularly on the recovery of oils from the pyrolysis of tire waste. For example, documents EP 0928817, WO 2013 / 170358, and JP2017 / 008214 describe the production of tire-grade carbon black from the pyrolysis of tire tire chips. Other research focuses on the recovery of intermediate products. Document WO 90 / 14409 examines the separation of pyrolysis oils from tire waste by distillation in order to recover valuable chemical compounds, particularly limonene.

[0006] Document CA 3 032 242 describes the catalytic depolymerization of plastics for the manufacture of monomers and waxes. However, the use of the effluents produced is not addressed.

[0007] Continuing its research, the applicant discovered that a rubber composition comprising a hydrocarbon oil obtained from the pyrolysis of a filler consisting mainly of polyethylene exhibits stiffness performance improved while preserving, or even enhancing, other characteristics. Definitions

[0008] The carbon-containing compounds mentioned in the description may be of fossil origin or bio-based. In the latter case, they may be, partially or totally, derived from biomass or obtained from renewable raw materials derived from biomass.

[0009] By Cn compound, we mean a compound comprising n carbon atoms. Similarly, by Cn-Cm compounds, we mean a set of compounds comprising from n to m carbon atoms.

[0010] By heteroatom, we mean an atom other than carbon or hydrogen, for example nitrogen, sulfur, oxygen.

[0011] By majority means, in a known way, representing at least 50% by weight. Detailed description of the invention

[0012] The invention relates to a rubber composition based on at least one elastomeric matrix comprising at least one elastomer, a reinforcing filler, a crosslinking system and a hydrocarbon oil consisting of a cut resulting from the pyrolysis of a filler comprising mainly polyethylene. Rubber composition Elastomer

[0013] The rubber composition according to the invention comprises at least one elastomer, preferably a diene elastomer. By diene elastomer, it should be understood that an elastomer which is derived at least in part (i.e. a homopolymer or a copolymer) from diene monomers (monomers bearing two carbon-carbon double bonds, conjugated or not).

[0014] These diene elastomers can be classified into two categories: "essentially unsaturated" or "essentially saturated". Generally, "essentially unsaturated" means a diene elastomer derived at least in part from conjugated diene monomers, having a proportion of diene motifs or units (conjugated dienes) greater than 15% (mole percent). Thus, diene elastomers such as butyl rubbers or EPDM-type diene-alpha-olefin copolymers do not fall under the preceding definition and can be described, in particular, as "essentially saturated" diene elastomers (low or very low proportion of diene motifs, always less than 15% (mole percent)). The diene elastomers included in the rubber composition according to the invention are preferably essentially unsaturated.

[0015] The term diene elastomer is particularly understood to mean a diene elastomer that can be used in the Rubber compositions conforming to the invention:

[0016] a) any homopolymer of a diene monomer, conjugated or not, having from 4 to 18 carbon atoms;

[0017] b) any copolymer of a diene, conjugated or not, having from 4 to 18 carbon atoms and at least one other monomer.

[0018] The other monomer may be ethylene, an olefin or a diene, conjugated or not.

[0019] Conjugated dienes with 4 to 12 atoms are suitable. of carbon, in particular 1,3-dienes, such as 1,3-butadiene and isoprene.

[0020] Suitable olefins are vinylaromatic compounds having 8 to 20 carbon atoms and aliphatic α-monoolefins having 3 to 12 carbon atoms.

[0021] Suitable examples of vinylaromatic compounds include styrene, ortho-, meta-, para-methylstyrene, the commercial "vinyl-toluene" mixture, para-tert-butylstyrene.

[0022] As aliphatic α-monoolefins, acyclic aliphatic α-monoolefins having from 3 to 18 carbon atoms are particularly suitable.

[0023] 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.

[0024] The above diene elastomers can, for example, be block, statistical, sequenced, microsequenced, and be prepared in dispersion or in solution; they can be coupled and / or star-shaped or functionalized with a coupling and / or star-shaped or functionalizing agent, for example epoxy-coated.

[0025] By "isoprene elastomer" is meant a homopolymer or a copolymer of isoprene, in other words a diene elastomer selected from the group consisting of natural rubber (NR) which can be plasticized or peptized, synthetic polyisoprenes (IR), the various isoprene copolymers, in particular isoprene-styrene copolymers (SIR), isoprene-butadiene copolymers (BIR) or isoprene-butadiene-styrene copolymers (SBIR), and mixtures of these elastomers.

[0026] Preferably, the composition according to the invention comprises at least 50 parts per annum of at least one butadiene elastomer, preferably chosen from the group consisting of polybutadienes, butadiene copolymers and mixtures thereof, pre preferentially chosen from the group consisting of polybutadienes, butadiene-styrene copolymers and their mixtures.

[0027] According to a preferred embodiment of the invention, the butadiene elastomer is a butadiene copolymer having a glass transition temperature (Tg) below -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 are described, for example, in documents WO2015 / 185394 and WO2017 / 168099.

[0028] Preferably and according to this embodiment, the composition according to the invention comprises at least 70 parts, preferably at least 90 parts, of at least one butadiene copolymer, preferably a butadiene-styrene copolymer.

[0029] Preferably, according to any one of the embodiments of the invention, the composition according to the invention further comprises at least 20 parts of an isoprene elastomer selected from the group consisting of natural rubber, synthetic polyisoprenes and their mixtures. Reinforcing load

[0030] The rubber composition according to the invention comprises a reinforcing filler. Any type of reinforcing filler known for its ability to reinforce an elastomeric composition usable for the manufacture of pneumatic tires can 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.

[0031] All carbon blacks are suitable as carbon blacks, particularly those of the HAF, ISAF, and SAF types conventionally used in tires (so-called tire-grade blacks). Among these, carbon blacks of the 100, 200, or 300 series (ASTM grades) are particularly suitable, such as NI 15, N134, N234, N326, N330, N339, N347, and N375, or, depending on the intended application, blacks of higher series (e.g., N660, N683, N772). 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 specific surface area BET of carbon blacks is measured according to standard D6556-10 [multipoint method (minimum 5 points) - gas: nitrogen - relative pressure range P / P0: 0.1 to 0.3].

[0032] In the present application, the term "reinforcing inorganic filler" shall be understood, by definition, as any inorganic or mineral filler (regardless of its color and whether natural or synthetic), also called "white" filler, "light" filler, or even "non-black filler" ("non-black filler") as opposed to carbon black, capable of reinforcing, on its own and without any means other than an intermediate coupling agent, a rubber composition intended for the manufacture of pneumatic tires, in other words suitable for replacing, in its reinforcing function, a conventional carbon black of pneumatic grade; such a filler is generally characterized, in a known way, by the presence of hydroxyl groups (-OH) on its surface.

[0033] Inorganic reinforcing fillers are suitable in particular mineral fillers of the siliceous type, preferably silica (SiO2) or of the aluminous type, in particular alumina (Al2O3).

[0034] The silica used can be any reinforcing silica known to those skilled in the art, in particular any precipitated or pyrogenated silica.

[0035] Precipitated silica can be produced from raw materials derived from inorganic sand (silicon dioxide from inorganic sand), from recycled materials such as foundry sands, end-of-life tires and in particular the treads of end-of-life tires comprising mainly silica as a reinforcing filler or from bio-based raw materials such as organic waste from plants, preferably inedible organic waste from plants.

[0036] Among the plants having silicon dioxide in their tissues, we can mention mustard, in particular mustard husks, grasses and more particularly among grasses bamboo leaves, ears of corn, sugar cane bagasse, rice, wheat, in particular rice husks, wheat husks.

[0037] Silica derived from non-renewable raw materials such as natural inorganic sand is usually obtained by heating sand in a glass furnace in the presence of sodium carbonate. The resulting sodium silicate is then dissolved in water, possibly in the presence of a base such as sodium hydroxide. Precipitated synthetic silica is formed from this aqueous solution by controlled treatment of the silicate with an acid (e.g., a mineral acid and / or an acidifying gas such as carbon dioxide). Sometimes, an electrolyte (e.g., sodium sulfate) may be present to promote the formation of precipitated silica particles. The recovered precipitated silica is amorphous precipitated silica.

[0038] Silica derived from bio-based raw materials such as those mentioned above can, for example, be obtained by burning the bio-based raw material in such a way as to recover the ash of this bio-based material, which contains mainly silicon dioxide. For example, for rice husks, and in a process equivalent to that above for silicas based on mineral or recycled raw materials, the rice husk ash is generally treated with a strong base such as, for example, sodium hydroxide, to form an aqueous silicate solution (for example, sodium silicate), after which a syn-silica Precipitated silica is formed by the controlled addition of an acid (e.g., a mineral acid and / or an acidifying gas such as carbon dioxide) in which an electrolyte (e.g., sodium sulfate) may be present to promote the formation of precipitated silica particles derived from rice husks. The recovered precipitated silica is amorphous precipitated silica. Silica from rice husk ash is commonly known as RHA silica (Rice Husk Ash Silica). Bio-based silicas are available, for example, from suppliers such as Solvay, Evonik, Quechen, Wilmar International, and Wuxi.

[0039] In summary, the synthesis of a precipitation silica usable within the framework of the invention can be carried out from a sodium silicate entirely obtained from bio-based raw materials, or recycled or of non-renewable origin, but also from a mixture of bio-based and / or recycled and / or non-renewable raw materials (such as commonly used sands).

[0040] Preferably, the precipitated silica, whether obtained from mineral, recycled or bio-based raw materials, has a specific surface area BET and a specific surface area CTAB both less than 450 m2 / g, preferably within a range of 30 to 400 m2 / g, in particular 60 to 300 m2 / g.

[0041] Any type of precipitated silica can be used, in particular highly dispersible precipitated silicas (known as "HDS" for "highly dispersible" or "highly dispersible silica"). These precipitated silicas, whether highly dispersible or not, are well known to those skilled in the art.

[0042] Examples include the silicas described in applications WO03 / 016215-A1 and WO03 / 016387-A1. Among the commercial HDS silicas, the following can be used in particular: “Ultrasil ® 5000GR”, “Ultrasil ® 7000GR” from Evonik, “Zeosil ® 1085GR”, “Zeosil® 1115 MP”, “Zeosil® 1165MP”, “Zeosil® Premium 200MP”, “Zeosil® HRS 1200 MP” from Solvay. As non-HDS silica, the following commercial silicas may be used: “Ultrasil® VN2GR”, “Ultrasil® VN3GR” silicas from Evonik, “Zeosil® 175GR” silica from Solvay, “Hi-Sil EZ120G(-D)”, “Hi-Sil EZ160G(-D)”, “Hi-Sil EZ200G(-D)”, “Hi-Sil 243LD”, “Hi-Sil 210”, “Hi-Sil HDP 320G” silicas from PPG, “K160”, “K185”, “K195” silicas from Wilmar International.

[0043] The physical state of the reinforcing inorganic filler is irrelevant, whether it is in the form of powder, microbeads, granules, spheres, or any other suitable densified form. Of course, the term "reinforcing inorganic filler" also includes mixtures of different reinforcing inorganic fillers, in particular highly dispersible siliceous and / or aluminous fillers.

[0044] The reinforcing inorganic filler used, in particular if it is silica, preferably has a BET surface area of ​​between 45 and 400 m2 / g, more preferably between 60 and 300 m2 / g.

[0045] Preferably, the reinforcing filler of the rubber composition according to the invention comprises from 10 to 150 parts per annum, preferably from 50 to 130 parts per annum, of silica. In a preferred arrangement, the reinforcing filler comprises predominantly silica and preferably is made of silica.

[0046] To couple the reinforcing inorganic filler to the elastomer, optionally a coupling agent (or bonding agent) at least bifunctional can be used in a known manner 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.

[0047] In particular, polysulfide silanes, called "symmetric" or "asymmetric" depending on their particular structure, can be used, as described for example in applications WO03 / 002648 (or US 2005 / 016651) and WO03 / 002649 (or US 2005 / 016650).

[0048] Examples of polysulfurized silanes include, in particular, polysulfides (notably disulfides, trisulfides or tetrasulfides) of bis-(alkoxyl(Cl-C4)-alkyl(Cl-C4)silyl-alkyl(Cl-C4)), such as bis(3-trimethoxysilylpropyl) or bis(3-triethoxysilylpropyl) polysulfides. Among these compounds, bis(3-triethoxysilylpropyl) tetrasulfide, abbreviated TESPT, with the formula [(C2H5O)3Si(CH2)3S2]2, and bis-(triethoxysilylpropyl) disulfide, abbreviated TESPD, with the formula [(C2H5O)3Si(CH2)3S]2, are particularly useful. We will also cite as preferential examples the polysulfides (in particular disulfides, trisulfides or tetrasulfides) of bis-(monoalkoxyl(Cl-C4)-dialkyl(Cl-C4)silylpropyl), more particularly the tetrasulfide of bis-monoethoxydimethylsilylpropyl as described in US patent application 2004 / 132880.

[0049] As a coupling agent other than polysulfurized alkoxysilane, mention shall be made in particular of bifunctional POS (polyorganosiloxanes) or polysulfurized hydroxysilanes as described in patent applications WO 02 / 30939 and WO 02 / 31041, or silanes or POS bearing azo-dicarbonyl functional groups, as described for example in patent applications WO 2006 / 125532, WO 2006 / 125533, WO 2006 / 125534.

[0050] In rubber compositions according to the invention, the content of coupling agent is preferably in a range of 5 to 18% by weight relative to the amount of silica, preferably in a range of 8 to 12% by weight relative to the amount of silica.

[0051] A person skilled in the art will understand that, as an equivalent charge to the reinforcing inorganic charge described in this paragraph, a reinforcing charge of another nature, in particular organic, could be used, provided that this reinforcing charge is covered with an inorganic layer such as silica, or has functional sites on its surface, in particular hydroxyl sites, allowing the bond to be established between the charge and the elastomer in the presence or not of a coating or coupling agent.

[0052] In a preferred arrangement in which the rubber composition according to the invention comprises an isoprene elastomer, the rubber composition preferably comprises at least 25 parts per annum of carbon black. Crosslinking system

[0053] The rubber composition according to the invention preferably comprises a sulfur-based crosslinking system including a metal oxide, a stearic acid derivative, and a vulcanization accelerator. This is referred to as a vulcanization system. The sulfur may be supplied in any form, in particular as molecular sulfur or as a sulfur-donating agent.

[0054] Sulfur is used preferably at a rate of 1 to 20 pc, preferably from 1 to 10 pc.

[0055] Any compound capable of acting as a vulcanization accelerator for diene elastomers in the presence of sulfur can 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 "MBTS"), N-cyclohexyl-2-benzothiazyl sulfenamide ("CBS"), N,N-dicyclohexyl-2-benzothiazyl sulfenamide ("DCBS"), N-ter-butyl-2-benzothiazyl sulfenamide ("TBBS"), N-ter-butyl-2-benzothiazyl sulfenimide ("TBSI"), tetrabenzylthiuram disulfide ("TBZTD"), zinc dibenzyldithiocarbamate ("ZBEC") and mixtures of these compounds.

[0056] The crosslinking system may also optionally include a vulcanization retarder. hydrocarbon oil

[0057] The rubber composition according to the invention comprises a hydrocarbon oil consisting of a cut resulting from the pyrolysis of a charge comprising mainly polyethylene.

[0058] By hydrocarbon oil, we mean an oil which is made up only of carbon and hydrogen atoms.

[0059] Said hydrocarbon oil preferably has a glass transition temperature ranging from -150°C to -50°C, preferably ranging from -120°C to -70°C and a number molar mass of less than 1000 g / mol, preferably less than 700 g / mol.

[0060] Preferably, the hydrocarbon oil mainly comprises compounds having more than 13 carbon atoms, preferably at most 5% by weight of compounds comprising at most 13 carbon atoms, and preferably at most 1% by weight of compounds comprising at most 13 carbon atoms.

[0061] Such properties enable the rubber composition according to the invention to achieve the desired performance.

[0062] Said hydrocarbon resin consists of a fraction obtained from the pyrolysis of a feedstock comprising mainly polyethylene. The method of obtaining the oil gives it rubber composition properties that differ from similar oils in terms of structure.

[0063] Preferably, the charge, consisting mainly of polyethylene which is pyrolyzed, also includes polystyrene, preferably at least 5% by weight of polystyrene and preferably at least 10% by weight of polystyrene. This combination of compounds in the charge makes it possible to obtain particularly interesting properties.

[0064] Preferably, the charge comprising mainly polyethylene comprises at least 60% by weight of polyethylene, preferably at least 70% by weight of polyethylene.

[0065] Preferably, the hydrocarbon oil has alkene functions at the end of the chain.

[0066] The hydrocarbon oil used in the invention can be obtained by a process comprising at least:

[0067] a) A pyrolysis step of the charge comprising mainly polyethylene allowing to obtain at least one pyrolysis oil;

[0068] b) A step of separating the pyrolysis oil carried out at a temperature of 50 to 90°C and a pressure of 0.8 to 1.2 bar.

[0069] Such a process may, for example, correspond to the process described in document CA 3 032 242. Pyrolysis step a)

[0070] The charge, consisting mainly of polyethylene, feeds a pyrolysis stage operated at a temperature between 300 and 600°C, allowing the production of a pyrolysis oil.

[0071] Pyrolysis is defined as the thermal decomposition of compounds in an inert or oxygen-poor atmosphere, that is to say, comprising less than 5% by volume, preferably less than 3% by volume and preferably less than 2% by volume. volume of oxygen, preferably in an inert atmosphere.

[0072] The pyrolysis step is preferably carried out at a pressure of less than 1 bar under an inert atmosphere, for example under a nitrogen atmosphere.

[0073] The pyrolysis step can be carried out in a pyrolysis reactor, and can be operated continuously, semi-continuously or in batch mode. Such reactors are well known to those skilled in the art.

[0074] Preferably, the pyrolysis step of the process for obtaining hydrocarbon oil comprises microwave-assisted pyrolysis. The thermal power required for pyrolysis is, in this case, supplied by microwave radiation.

[0075] Preferably in this configuration, the power delivered by the microwave device of microwave thermally assisted pyrolysis is between 0.1 and 10 kW / kg load, preferably between 0.1 and 5 kW / kg load, preferably between 0.5 and 4 kW / kg load and preferably between 1 and 4 kW / kg load.

[0076] When the pyrolysis step is operated continuously or semi-continuously, it can be implemented in several zones. Step b) of pyrolysis oil separation

[0077] The pyrolysis oil is then treated in a separation step, for example carried out at a temperature ranging from 50 to 90°C and a pressure ranging from 0.8 to 1.2 bar. Such a separation step can be implemented by any means known to those skilled in the art, for example by evaporation in a distillation column, in an evaporator such as a scraped film evaporator, or by any other means.

[0078] The separation step makes it possible to obtain the hydrocarbon oil, which preferably comprises mainly compounds having more than 13 carbon atoms, preferably at most 5% by weight of compounds comprising at most 13 carbon atoms, and preferably at most 1% by weight of compounds comprising at most 13 carbon atoms, and an effluent of lighter compounds.

[0079] This last effluent can be treated again, for example fractionated for other uses. Other additives

[0080] The rubber composition according to the invention 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 anti-ozone waxes, anti-ozone agents or chemical antioxidants, plasticizers other than those described above, anti-fatigue agents, reinforcing resins, or acceptors (by example, a novolac phenolic resin) or methylene donors (e.g. HMT or H3M).

[0081] In a preferred arrangement, the rubber composition according to the invention may comprise from 20 to 100 parts per annum of plasticizing hydrocarbon resin.

[0082] The term "resin" is reserved in this application, by definition, for a compound which is solid at room temperature (20°C), as opposed in particular to a liquid plasticizing agent such as an oil.

[0083] Hydrocarbon resins are polymers well known to those skilled in the art, essentially based on carbon and hydrogen but potentially containing other types of atoms, and are particularly useful as plasticizing or tackifying agents in polymer matrices. They are inherently miscible (i.e., compatible) at the ratios used with the polymer compositions for which they are intended, so as to act as true diluents. They have been described, for example, in the book entitled "Hydrocarbon Resins" by R. Mildenberg, M. Zander, and G. Collin (New York, VCH, 1997, ISBN 3-527-28617-9), Chapter 5 of which is devoted to their applications, particularly in pneumatic rubber (5.5. "Rubber Tires and Mechanical Goods"). They can be aliphatic, cycloaliphatic, aromatic, hydrogenated aromatic, of the aliphatic / aromatic type, i.e. based on aliphatic and / or aromatic monomers.They can be natural or synthetic, petroleum-based or not (if so, also known as petroleum resins). Their Tg is preferably above 30°C, specifically between 30°C and 95°C.

[0084] Examples of such hydrocarbon resins may be cited from the group consisting of cyclopentadiene homopolymer or copolymer resins (abbreviated CPD), dicyclopentadiene homopolymer or copolymer resins (abbreviated DCPD), terpene homopolymer or copolymer resins, C5-cut homopolymer or copolymer resins, C9-cut homopolymer or copolymer resins, alpha-methyl-styrene homopolymer or copolymer resins and mixtures of these resins.Among the copolymer resins mentioned above, special mention can be made of those selected from the group consisting of (D)CPD / vinylaromatic copolymer resins, (D)CPD / terpene copolymer resins, terpene phenol copolymer resins, (D)CPD / C5 cut copolymer resins, (D)CPD / C9 cut copolymer resins, terpene / vinylaromatic copolymer resins, terpene / phenol copolymer resins, C5 cut / vinylaromatic copolymer resins, and mixtures of these resins.

[0085] The term "terpene" here encompasses, in a known manner, the monomers alpha-pinene, beta-pinene and limonene; preferably, a limonene monomer is used, The compound is known to exist as three possible isomers: L-limonene (levorotatory enantiomer), D-limonene (dextrorotatory enantiomer), or dipentene, a racemic mixture of the dextrorotatory and levorotatory enantiomers. Suitable vinylaromatic monomers include, for example, styrene, alpha-methylstyrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, vinyl-toluene, para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, hydroxystyrenes, vinylmesitylene, divinylbenzene, vinylnaphthalene, and any vinylaromatic monomer derived from a C9 cut (or more generally from a C8 to C10 cut).

[0086] In particular, we can mention the resins chosen from the group consisting of homopolymer (D)CPD resins, (D)CPD / styrene copolymer resins, polylimonene resins, limonene / styrene copolymer resins, limonene / D(CPD) copolymer resins, C5 / styrene copolymer resins, C5 / C9 copolymer resins, and mixtures of these resins.

[0087] C5 resins are commercially available, for example, sold by Eastman under the names "Piccotac 1105" or "Impera R1507", by Exxon under the name "Escorez 1102", by Kolon under the name "Hikorez Al 100", or by Cray Valley Total under the name "Wingtack 98". C5-C9 resins are commercially available, for example, sold by Exxon under the name "OPPERA 373", by Eastman under the name "Piccotac 8090", and by Cray Valley Total under the name "Wingtack STS". Preparation of rubber compositions

[0088] The rubber composition according to the invention is manufactured in suitable mixers, using preparation phases well known to those skilled in the art:

[0089] - a thermomechanical working or mixing phase, which can be conducted in a The only thermomechanical step in which all the necessary constituents, including the elastomeric matrix, hydrocarbon resin, fillers, and any other miscellaneous additives, are introduced into a suitable mixer such as a standard internal mixer (e.g., of the Banbury type). The incorporation of the filler into the telastomer can be carried out in one or more stages by thermomechanical mixing. If the filler, particularly 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, the masterbatch is mixed directly, and any other elastomers or fillers present in the composition that are not in masterbatch form are incorporated, as well as any other additives. other miscellaneous additives.

[0090] Thermomechanical mixing is carried out at high temperature, up to a maximum temperature between 110°C and 200°C, preferably between 130°C and 185°C, for a duration generally between 2 and 10 minutes.

[0091] - a second phase of mechanical work is then carried out in a mixer external 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.

[0092] The crosslinking system will be added during the second phase.

[0093] 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 extruded in the form of a semi-finished (or profile) of rubber.

[0094] 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 that can be used in a tire.

[0095] The cooking 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 cooking temperature, the crosslinking system adopted, the crosslinking kinetics of the composition considered or the size of the tire. Vehicle bandage

[0096] The present invention also relates to vehicle tires comprising a rubber composition based on at least one elastomer and a hydrocarbon oil according to the invention.

[0097] The vehicle tire can be pneumatic or non-pneumatic. By non-pneumatic, it is understood that this tire is capable of supporting the vehicle's load by means other than a pressurized inflation gas, for example by means of guy wires.

[0098] The vehicle tire according to the invention shall 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.

[0099] A vehicle tire typically comprises a crown, two sides, and two ridges, each side connecting each ridge to the crown. Each ridge includes at least one circumferential reinforcing element, generally in the form of a rod.

[0100] The vehicle tire also includes a carcass reinforcement anchored in each bead and extending into each sidewall and the top. The carcass reinforcement includes a carcass layer comprising a portion wrapped around each circumferential reinforcement element.

[0101] The crown comprises a tread intended to come into contact with the ground during the rolling of the vehicle tire, as well as a crown reinforcement arranged radially between the tread and the carcass reinforcement. The crown reinforcement comprises a working reinforcement including at least one working layer. The crown reinforcement also comprises a reinforcing reinforcement arranged radially outside the working reinforcement, the reinforcing reinforcement being axially delimited by two axial edges and comprising at least one reinforcing wire element wound circumferentially helically so as to extend axially from one axial edge to the other axial edge of the reinforcing reinforcement along a principal direction of the wire element(s) of each reinforcing wire element.

[0102] Thus, the invention also relates to a vehicle tire having a sidewall, as described above, said sidewall comprising at least one rubber composition according to the invention.

[0103] The invention also relates to a vehicle tire whose tread comprises a rubber composition according to the invention. Measurement methods Glass transition temperature

[0104] The glass transition temperature Tg is measured in a known manner by differential scanning calorimetry, or DSC, for example, and unless otherwise specified, according to ISO 11357-2:2014. Macrostructure (Mw, Mn)

[0105] The macrostructure (average molar mass by mass and by number, respectively denoted Mw, Mn) is determined by size exclusion chromatography (SEC) as indicated below.

[0106] As a reminder, SEC analysis, for example, consists of separating macromolecules in solution according to their size using columns filled with a porous gel; the molecules are separated according to their hydrodynamic volume, with the largest being eluted first. The sample to be analyzed is simply pre-solubilized in a suitable solvent, tetrahydrofuran, at a concentration of 1 g / liter. The solution is then filtered through a 0.45 µm porosity filter before being injected into the instrument at a flow rate of 1 ml / min and a temperature of 35°C. The instrument used is, for example, a Waters Alliance chromatographic system.

[0107] A Moore calibration is conducted with a series of commercial standards of po Lystyrene with low dispersity D (less than 1.2), of known molar masses, covering the mass range to be analyzed. From the recorded data (mass distribution curve of molar masses), Mw, Mn, and D = Mw / Mn are deduced.

[0108]

[0109] All molar mass values ​​indicated in this application are therefore relative to calibration curves produced with polystyrene standards. Tensile tests

[0110] 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 humidity (50+5% relative humidity) conditions, according to French standard NF T 40-101 (December 1979).

[0111] The tensile stresses (in MPa) and elongations at break (AR in %) were measured at 23°C ± 2°C, according to standard NF T 46-002, on samples baked for 25 minutes at 150°C or 90 minutes at 160°C, at the second elongation (i.e., after accommodation). The energy at break is equal to the product of the elongation at break and the tensile stress.

[0112] The results are expressed on a scale of 100, with the value 100 assigned to the control. A result greater than 100 indicates that the composition of the example considered exhibits a higher breaking energy than the control. Dynamic properties

[0113] The dynamic properties G* and tan(φ) are measured on a viscoelastic analyzer (Metravib VA4000), according to ASTM D 5992-96. The response of a cross-linked composite sample (cylindrical specimen 4 mm thick and 400 mm² cross-section) is recorded under sinusoidal alternating simple shear loading at a frequency of 10 Hz, under defined temperature conditions, for example, 0°C, 23°C, and 100°C, according to ASTM D 1349-99. A strain amplitude sweep is performed from 0.1 to 100% (forward cycle), then from 100% to 1% (reverse cycle). The results used are the complex dynamic shear modulus G* and the loss factor tan(φ). For the reverse cycle, the maximum observed value of tan(φ) and the value of G* are indicated. The tan(φ) value measured at 100°C indicates dry grip. A high value denotes improved grip. The tan(φ) value measured at 23°C indicates rolling resistance.A low value indicates lower rolling resistance. Examples Example 1 - Synthesis of hydrocarbon oil

[0114] A pyrolysis step as described in document CA 3 032 242 is fed with a charge comprising 75% by weight of polyethylene (low-density polyethylene, (LDPE) and 25% by weight of polystyrene in the form of granules with a largest dimension between 3 and 5 mm. The microwave pyrolysis stage is carried out under an inert nitrogen atmosphere with a power of approximately 600 W. Pyrolysis is stopped when the temperature of the gases exiting the pyrolysis process falls below 50°C.

[0115] The pyrolysis effluent is separated by distillation into an extract and a raffinate constituting the hydrocarbon oil. Distillation is carried out under vacuum at a head pressure of 42 mbar and the temperature adjusted so that the raffinate comprises at most 1% by weight of compounds containing 13 carbon atoms. The raffinate therefore consists mainly of compounds with more than 13 carbon atoms.

[0116] The hydrocarbon oil obtained has the following characteristics:

[0117] [Tables] Example: Oil Glass transition temperature (Tg, °C) -97 Number molar mass (Mn, g / mol) 432 Weight molar mass (Mw, g / mol) 637 Example 2 - Rubber compositions

[0118] The rubber compositions detailed in Table 3 are manufactured by introducing all the constituents onto an internal mixer, with the exception of the vulcanizing system. The vulcanizing agents (sulfur and accelerator) are introduced onto an external mixer at a low temperature (the rollers of the mixer being at 30 °C). The compositions are cured under pressure at 150 °C.

[0119] To make these compositions, different oils are used, the characteristics of which are indicated in the table below. Tg [°C] Mn [g / mol] Mw [g / mol] Origin TDAE -51 520 650 “Vivatec 500” from the company H&R Group MES -62 589 711 “Vivatech 200” from the company H&R Group HTO -90 - - “Agri-pure 80” from the company Cargill Hydrocarbon oil -97 432 637 See example 1

[0120] TDAE and MES oils are aromatic oils. HTO oil is a sunflower oil.

[0121] Table 3 shows different rubber compositions using the oils presented in Table 2 and the measurement results obtained.

[0122] [Tables3] Tl T2 T3 Cl T4 T5 T6 C2 NR (1) 50 50 50 50 0 0 0 0 BR (2) 50 50 50 50 0 0 0 0 SBR (3) 0 0 0 0 100 100 100 100 Silica (4) 0 0 0 0 110 110 110 110 Coupling agent (5) 0 0 0 0 8.8 8.8 8.8 8.8 Carbon black (6) 50 50 50 50 4 4 4 4 6PPD (7) 3 3 3 3 1.5 1.5 1.5 1.5 ZnO (8) 2.5 2.5 2.5 2.5 1.8 1.8 1.8 1.8 Stearic acid (9) 1.1 1.1 1.1 1.1 2 2 2 2 CBS (10) 1.4 1.4 1.4 1.4 2 2 2 2 Sulfur 1.4 1.4 1.4 1.4 1.4 1.3 1.3 1.3 1.3 DPG (11) 0 0 0 0 2 2 2 2 Resin (12) 0 0 0 0 22 22 22 22 TDAE 20 0 0 0 33 0 0 0 MES 0 20 0 0 0 33 0 0 HTO 0 0 20 0 0 0 33 0 Hydrocarbon oil 0 0 0 20 0 0 0 33 Results (base 100) Tan d 100°C max return 100 102 100 106 100 92 101 100 G*10% return at 23°C 100 101 89 132 100 127 109 134 tan(φ) 23°C max return 100 100 88 95 100 96 85 91 Breaking energy at 23°C* 100 40 73 97 100 135 144 126

[0123] Compositions T1, T2, T3 and C1 are cooked for 40 minutes. Compositions T4, T5, T6 and C2 are cooked for 60 minutes.

[0124] Table 3 references: (1) Natural rubber

[0125] (2) Neodymium Polybutadiene “SYNTECA® 63” marketed by the company Synthos

[0126] (3) SBR solution (content expressed as dry SBR) with 27% styrene and 17.5% motifs butadiene 1-2 by weight (Tg=-48°C);

[0127] (4) Silica, “Ultrasil 7000 GR” from the company Degussa(5) Coupling agent: Evonik “Si69” - Degussa(6) Carbon black, ASTM N234 grade

[0128] (7) N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (“Santaflex 6-PPD”) of Flexsys and 2,2,4-trimethyl-l,2-dihydroquinoline (TMQ)(8) Zinc oxide, industrial grade - Umicore(9) Stearin, "Pristerene 4931" from Uniqema (10) N-Cy-clohexyl-2-benzothiazolesulfenamide ("Santicure CBS" from Flexsys)

[0129] (11) Diphenylguanidine, “Perkacit DPG” from Flexsys

[0130] (12) C5 / C9 resin (“Oppera PR373” of Exxon)

[0131] The results are expressed on a base of 100, with 100 assigned to composition T1 for compositions T1, T2, T3, and C1, and to composition T4 for compositions T4, T5, T6, and C2. 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.

[0132] It is observed that the stiffness properties are improved for the examples according to the invention, while the other properties are either maintained or improved. When the composition mainly comprises a butadiene copolymer, it is further observed that the energy-at-break properties are significantly improved.

Claims

Demands

1. Rubber composition based on at least one elastomeric matrix comprising at least one elastomer, a reinforcing filler, a crosslinking system and a hydrocarbon oil consisting of a cut obtained from the pyrolysis of a filler comprising predominantly polyethylene.

2. Composition according to the preceding claim wherein the filler comprising predominantly polyethylene comprises polystyrene, preferably at least 5% by weight of polystyrene and preferably at least 10% by weight of polystyrene.

3. Composition according to any one of the preceding claims wherein the filler comprising predominantly polyethylene comprises at least 60% by weight of polyethylene, preferably at least 70% by weight of polyethylene.

4. Composition according to any one of the preceding claims wherein the hydrocarbon oil has a glass transition temperature ranging from -150°C to -50°C, preferably ranging from -120°C to -70°C and a number molar mass of less than 1000 g / mol, preferably less than 700 g / mol.

5. Composition according to any one of the preceding claims wherein the hydrocarbon oil comprises predominantly compounds having more than 13 carbon atoms, preferably at most 5% by weight of compounds comprising at most 13 carbon atoms, and preferably at most 1% by weight of compounds comprising at most 13 carbon atoms.

6. Composition according to any one of the preceding claims wherein the hydrocarbon oil is obtained by a process comprising at least: a. A pyrolysis step of the feed consisting mainly of polyethylene enabling the production of at least one pyrolysis oil; b. A separation step of the pyrolysis oil carried out at a temperature of 50 to 90°C and a pressure of 0.8 to 1.2 bar.

7. Composition according to any one of the preceding claims comprising at least 50 pieces of at least one butadien elastomer.

8. Composition according to any one of the preceding claims wherein the reinforcing filler comprises from 10 to 150 parts, preferably from 50 to 130 parts, of silica.

9. Composition according to claim 7, or claim 8 when it depends on claim 7, wherein the butadiene elastomer is a butadiene copolymer having a glass transition temperature Tg below -20°C, preferably between -20°C and -110°C.

10. Composition according to the preceding claim comprising at least 70 parts, preferably at least 90 parts, of at least one butadiene copolymer, preferably a butadiene-styrene copolymer.

11. Composition according to any one of the preceding claims further comprising 20 to 100 pieces of plasticizing hydrocarbon resin.

12. Composition according to any one of the preceding claims further comprising at least 20 pieces of an isoprene elastomer selected from the group consisting of natural rubber, synthetic polyisoprenes and mixtures thereof.

13. Vehicle bandage comprising a rubber composition according to any one of the preceding claims.

14. Vehicle tire comprising a tread of a rubber composition according to any one of claims 1 to 11

15. 1 1. Vehicle bandage having a sidewall, said sidewall comprising at least one composition according to claim 12.