COMPOSIÇÃO DE BORRACHA QUE COMPREENDE POLIETILENO COM BAIXA TEMPERATURA DE FUSÃO

Abstract

RUBBER COMPOSITION COMPRISING POLYETHYLENE WITH LOW MELTING POINT. The invention relates to a rubber composition based on at least one diene elastomer, 10 to 60 phr of carbon black, 5 to 30 phr of silica, a polyethylene having a melting point between 120 °C and 160 °C, and a crosslinking system in which carbon black represents 50% to 95% by weight relative to the total weight of carbon black and silica. The invention also relates to a method for preparing the rubber composition and to a rubber article comprising the composition according to the invention.

Description

[0001] The present invention relates to rubber compositions that exhibit a good cost-benefit ratio of performance between resistance to mechanical stress and hysteresis. It is particularly of interest to rubber articles such as pneumatic tires, non-pneumatic tires, tracks, conveyor belts or any other rubber article where the aforementioned cost-benefit ratio of performance would be desirable.

[0002] In particular, the rubber compounds of the invention are very interesting when used in pneumatic tire treads for civil engineering vehicles. In fact, these tires must have very different technical characteristics from tires intended for vehicles that travel exclusively on roads (i.e., on bituminous soil), since the nature of the off-road soils in which they mainly operate is very different, and notably much more aggressive, due to their stony nature. Furthermore, unlike tires for passenger vehicles, for example, tires for heavy civil engineering equipment must be able to withstand a load that can be extremely heavy. Consequently, known solutions for tires that travel on bituminous soil are not directly applicable to off-road tires, such as tires for civil engineering vehicles.

[0003] During its journey, a tire tread is subjected to mechanical stress and wear resulting from direct contact with the ground. In the case of a tire mounted on a vehicle carrying heavy loads, the mechanical stress and wear suffered by the tire are amplified by the weight it supports. Tires for mining vehicles, in particular, are subjected to strong demands, both locally: driving over the macro-indentations represented by the pebbles that make up the tracks (crushed rock), and globally: significant torque transmission due to the inclinations of the Petition 870220073015, dated 08 / 15 / 2022, page 13 / 45 2 / 29 lanes for entering or exiting "pits, or open-pit mines, are on the order of 10%, and there are strong demands on tires when vehicles make U-turns for loading and unloading maneuvers.

[0004] This has the consequence that the cracking principles that are created in the tire tread under the effect of these demands and aggressions tend to propagate even further on the surface or inside the tread, potentially causing localized or generalized tears in the tread. These demands can therefore trigger tread damage and thus reduce the lifespan of the tread and therefore the tire. A tire that runs on stony ground is highly exposed to aggressions and therefore to the principles of cracking and cuts. The very aggressive nature of stony ground exacerbates not only this type of aggression on the tread, but also its consequences on the tread.

[0005] This is particularly true for tires fitted to civil engineering vehicles that typically operate in mines or quarries. This is equally true for tires fitted to agricultural vehicles due to the stony soil of arable land. Tires fitted to heavy-duty construction vehicles that operate on both stony and bituminous soils also experience these same stresses. Due to the two aggravating factors, which are the weight carried by the tire and the aggressive nature of the terrain, resistance to the initiation and / or propagation of tread cracks on a tire for a civil engineering vehicle, an agricultural vehicle, or a heavy-duty construction vehicle becomes crucial to minimize the impact of the stresses suffered by the tread.

[0006] Therefore, it is important to have tires for vehicles, particularly those intended for use on stony ground and carrying heavy loads, whose tread exhibits sufficient resistance to the initiation and / or propagation of cracks to minimize the effect of a crack incipient on the tread's lifespan. To solve this problem, it is known to those skilled in the art that, for example, natural rubber in treads allows one to obtain Petition 870220073015, dated 08 / 15 / 2022, page 14 / 45 3 / 29 high resistance properties to crack initiation and / or propagation.

[0007] Furthermore, it is also interesting that the proposed solutions to solve this problem do not penalize the other properties of the rubber compound, notably the hysteresis, which translates to the compound's ability to dissipate heat. In fact, the use of a highly hysteretic compound in a tire can manifest itself in an increase in the tire's internal temperature, which can trigger a decrease in the tire's durability.

[0008] Having seen the foregoing, there is a permanent objective to provide rubber compounds that offer an improved cost-benefit ratio between resistance to aggression and hysteresis.

[0009] This cost-benefit ratio of performance is equally interesting for rubber tracks intended to equip construction vehicles or agricultural vehicles for the same reasons as those set out above. It is equally interesting for conveyor belts (or conveyor belts) that can receive large quantities of soil, minerals, gravel, rocks and that can dissipate a lot of energy via internal dissipation of the constituent material of the belt at the moment of perforation of the belt between its loading and the support that triggers it.

[0010] Solutions have been proposed to improve this cost-benefit ratio. For example, application WO 2016 / 202970 Al proposes using a specific composition whose elastomeric matrix comprises a diene elastomer chosen from the group consisting of polybutadienes, butadiene copolymers and their mixtures, and a styrenic thermoplastic elastomer comprising at least one rigid styrenic segment and at least one flexible diene segment comprising at least 20% by mass of conjugated diene units.

[0011] However, manufacturers are always researching solutions to further improve the cost-benefit ratio of performance between resistance to aggression and hysteresis, preferably regardless of the nature of the elastomeric matrix.

[0012] Continuing her research, the Applicant found in a way Petition 870220073015, dated 08 / 15 / 2022, page 15 / 45 4 / 29 unexpectedly, the use of polyethylene with a melting point between 120 °C and 160 °C in the presence of a specific filler cut in a rubber compound allows for improved cost-benefit ratio of the aforementioned performance.

[0013] Thus, the invention relates to a rubber composition based on at least one diene elastomer, 10 to 60 phr of carbon black, 5 to 30 phr of silica, a polyethylene having a melting temperature between 120 °C and 160 °C, and a crosslinking system in which carbon black represents 50% to 95% by weight relative to the total weight of carbon black and silica.

[0014] The same also has as its object a rubber article comprising a rubber composition according to the invention, as well as a pneumatic or non-pneumatic tire whose tread comprises a rubber composition according to the invention. I - DEFINITIONS

[0015] The expression “composition based on” should be understood as a composition that includes the mixture and / or the product of in situ reaction of different constituents used, some of these constituents being able to react and / or being intended to react with each other, at least partially, at different stages of the composition's manufacture; the composition may thus be in the fully or partially crosslinked state or in the non-crosslinked state.

[0016] The expression “part by weight to one hundred parts by weight of elastomer” (or phr) should be understood within the scope of the present invention as the part by mass to one hundred parts by mass of elastomer.

[0017] In this document, unless expressly stated otherwise, all percentages (%) indicated are percentages (%) by mass.

[0018] On the other hand, any range of values ​​designated by the expression “between a and b” represents the domain of values ​​in the range from more than a to less than b (that is, limits a and b excluded) while any range of values ​​designated by the expression “from a to b” means the domain of values ​​in the range from a to b (that is, Petition 870220073015, dated 08 / 15 / 2022, p. 16 / 45 5 / 29 including the strict limits a and b). In this document, when a range of values ​​is designated by the expression "from a to b", the range represented by the expression "between a and b" is also and preferably designated.

[0019] When reference is made to a “major compound,” it is understood within the present invention that this compound is the major compound among compounds of the same type in the composition, that is, it is the one that represents the largest quantity by mass among compounds of the same type. Thus, for example, a major elastomer is the elastomer that represents the largest mass relative to the total mass of elastomers in the composition. Similarly, a so-called major filler is the one that represents the largest mass among the fillers in the composition. By way of example, in a system comprising a single elastomer, it is the major elastomer within the present invention; and in a system comprising two elastomers, the major elastomer represents more than half of the mass of elastomers. Conversely, a “minor” compound is a compound that does not represent the largest mass fraction among compounds of the same type.Preferably, by "majority" it is understood to mean present in more than 50%, preferably more than 60%, 70%, 80%, 90%, and most preferably the majority compound represents 100%.

[0020] The carbon-containing compounds mentioned in the description may be of fossil or biogenic origin. In the latter case, they may be partially or wholly derived from biomass or obtained from renewable raw materials derived from biomass. Notably included are polymers, plasticizers, fillers, etc.

[0021] All glass transition temperature values ​​“Tg” described in this document are measured using a method known as DSC (Differential Scanning Calorimetry) in accordance with ASTM D3418 (1999). II - DESCRIPTION OF THE INVENTION II-A COMPOSITION II-A-1 ELASTOMER MATRIX

[0022] The composition according to the invention may contain a single diene elastomer or a mixture of several diene elastomers. Petition 870220073015, dated 08 / 15 / 2022, page 17 / 45 6 / 29

[0023] By “diene” elastomer (or interchangeably rubber), whether natural or synthetic, it should be understood in a known manner an elastomer consisting at least in part (that is, a homopolymer or a copolymer) of diene monomer units (monomers bearing two carbon-carbon double bonds, conjugated or not).

[0024] These diene elastomers can be classified into two categories: “essentially unsaturated” or “essentially saturated”. A “essentially unsaturated” elastomer is generally understood to be a diene elastomer derived at least in part from conjugated diene monomers, which has a ratio of diene-origin motifs or units (conjugated dienes) that is greater than 15% (mole percent); thus, diene elastomers such as butyl rubbers or EPDM-type diene-alpha-olefin copolymers do not fall under the previous definition and can notably be qualified as “essentially saturated” diene elastomers (ratio of weak or very weak diene-origin motifs, always less than 15%). Advantageously, the diene elastomer is an essentially unsaturated diene elastomer.

[0025] Specifically, the term "diene elastomer suitable for use within the scope of the present invention" means: 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.

[0026] The other monomer can be ethylene, an olefin or a diene, conjugated or not.

[0027] By way of conjugated dienes, conjugated dienes having from 4 to 12 carbon atoms are appropriate, in particular the 1,3-dienes, such as notably 1,3-butadiene and isoprene.

[0028] As for olefins, suitable are the vinyl aromatic compounds which have from 8 to 20 carbon atoms and the aliphatic α-mono-olefins which have from 3 to 12 carbon atoms. Petition 870220073015, dated 08 / 15 / 2022, p. 18 / 45 7 / 29

[0029] Examples of vinyl aromatic compounds include, for instance, styrene, ortho-, meta-, para-methylstyrene, the commercial mixture “vinyl-toluene”, and para-tert-butylstyrene.

[0030] As aliphatic α-monoolefins, acyclic aliphatic α-monoolefins having from 3 to 18 carbon atoms are particularly suitable.

[0031] Preferably, the diene elastomer is chosen from the group consisting of polybutadienes (BR), synthetic polyisoprenes (IR), natural rubber (NR), butadiene copolymers, isoprene copolymers and mixtures thereof. Preferably, the diene elastomer is chosen from the group consisting of synthetic polyisoprenes, natural rubber and mixtures thereof.

[0032] Butadiene copolymers are preferably chosen from the group consisting of butadiene-styrene copolymers (SBR). It will be noted that SBR can be prepared in emulsion (ESBR) or in solution (SSBR). Whether it is ESBR or SSBR. Among styrene-butadiene based copolymers, in particular SBR, those with a styrene content between 5% and 60% by weight, and more particularly between 20% and 50%, a molar content (%) of -1,2 linkages in the butadiene portion between 4% and 75%, and a molar content (%) of trans-1,4 linkages between 10% and 80% can be notably mentioned. Advantageously, the butadiene-styrene copolymer is a solution-prepared SBR and has a styrene content between 5% and 60%, preferably 6% to 30%, by weight relative to the total weight of the copolymer, and a molar percentage (%) of -1,2 linkages in the butadiene portion between 4% and 75%, preferably between 15% and 30%.

[0033] Among isoprene copolymers, particular mention is made of isobutene-isoprene copolymers (butyl rubber - IIR), isoprene-styrene copolymers (SIR), isoprene-butadiene copolymers (BIR) or isoprene-butadiene-styrene copolymers (SBIR).

[0034] In a particularly advantageous manner, the diene elastomer comprises mainly, preferably exclusively, at least one polyisoprene, preferably at least one epoxidized polyisoprene.

[0035] In this document, polyisoprene means any polyisoprene, Petition 870220073015, dated 08 / 15 / 2022, page 19 / 45 8 / 29 whether epoxidized or not. Advantageously, the polyisoprene is a non-epoxidized polyisoprene chosen from the group consisting of natural rubber, a synthetic polyisoprene and one of their mixtures. Advantageously, the non-epoxidized polyisoprene has a 1,4-cis linkage molar ratio of at least 90%.

[0036] Epoxidized polyisoprene is understood to be polyisoprene that has undergone an epoxidation step. Epoxidized polyisoprene may be epoxidized natural rubber, epoxidized synthetic polyisoprene having a 1,4-cis linkage molar ratio of at least 90% before epoxidation, or a mixture thereof.

[0037] The epoxidized polyisoprene used within the scope of the present invention is an elastomer and should not be confused with a low molar mass epoxidized polyisoprene generally used as a plasticizer which is not an elastomer given its low molar mass. An epoxidized polyisoprene as an elastomer generally has a high Mooney viscosity in the as-is state. By way of indication, the Mooney viscosities (ML 1+4) at 100 °C of epoxidized polyisoprenes usable within the scope of the present invention are preferably from 30 to 150, more preferably from 40 to 150, and even more preferably from 50 to 140.

[0038] Mooney viscosity is measured using an oscillating consistometer as described in ASTM D1646 (1999). The measurement is performed according to the following principle: the sample analyzed in the raw state (i.e., before cooking) is molded (shaped) in a cylindrical container heated to a given temperature (e.g., 100 °C). After 1 minute of preheating, the rotor rotates within the container at 2 revolutions / minute, and the torque required to drive this movement is measured after 4 minutes of rotation. Mooney viscosity (ML 1+4) is expressed in “Mooney units” (MU, with 1 MU = 0.83 Newton-meter).

[0039] Epoxidized polyisoprene, whether it is epoxidized natural rubber or epoxidized synthetic polyisoprene, can be obtained by a method known as epoxidation of polyisoprene, for example, by methods based on chlorohydrin or bromhidrin or methods based on hydrogen peroxides, alkyl hydroperoxides or peracids (such as peracetic acid or performic acid). Polyisoprenes Petition 870220073015, dated 08 / 15 / 2022, page 20 / 45 9 / 29 epoxidized polymers are commercially available. The epoxidation molar ratio, which is a manufacturer's datum, corresponds to the ratio between the number of moles of epoxidized isoprene units and the number of moles of isoprene units in the polyisoprene before epoxidation. The "epoxidation rate," expressed as a molar percentage (% mol), refers to the number of moles of epoxidized cis-1,4-polyisoprene motifs present in the rubber polymer per 100 moles of total monomer motifs in that same polymer. The epoxidation rate can be notably measured by 1H NMR analysis.

[0040] As examples of commercially available epoxidized polyisoprenes, one can mention Epoxyprene 25 and Epoxyprene 50 from Guthrie or Ekoprena 25 and Ekoprena 50 from Felda.

[0041] According to the present invention, the expression "at least one epoxidized polyisoprene" should be understood as one or more epoxidized polyisoprenes that may differ either in their microstructure, their macrostructure, or their epoxidation rate. In the case where the polyisoprene comprises several epoxidized polyisoprenes, the reference to the amount of epoxidized polyisoprene in the polyisoprene applies to the total mass of epoxidized polyisoprenes in the polyisoprene. For example, the characteristic according to which epoxidized polyisoprene is present in the rubber composition at a rate greater than 50 phr means that, in the case of a mixture of epoxidized polyisoprenes, the total mass of epoxidized polyisoprenes is greater than 50 phr.

[0042] In the case where the epoxidized polyisoprene is a mixture of epoxidized polyisoprenes that may differ from each other by their molar ratio of epoxidation, the reference to a molar ratio of epoxidation, whether preferential or not, applies to each of the epoxidized polyisoprenes in the mixture.

[0043] According to the invention, the at least one epoxidized polyisoprene advantageously exhibits an epoxidation molar ratio in the range of 5% to 85%, preferably 10% to less than 80%, preferably 15% to 75%. Advantageously, the epoxidation molar ratio of the at least one epoxidized polyisoprene can be comprised in a range of 40% to 80%, of Petition 870220073015, dated 08 / 15 / 2022, page 21 / 45 10 / 29 preferably from 45% to 75%. This epoxidation ratio is particularly advantageous for improving the reinforcement of the rubber compound. Alternatively, the molar ratio of epoxidation of at least one epoxidized polyisoprene may be comprised in a range of 10% to less than 49%, preferably from 15% to less than 40%.

[0044] The diene elastomer content, preferably polyisoprene, preferably epoxidized polyisoprene, in the composition according to the invention, is advantageously comprised in a range of 50 to 100 phr, preferably 75 to 100 phr, and more preferably 100 phr. II-A-2 LOADS

[0045] According to the invention, the composition is based on a filler comprising 10 to 60 phr of carbon black and 5 to 30 phr of silica, with carbon black representing 50% to 95% by weight of the total weight of carbon black and silica.

[0046] The carbon blacks usable within the scope of the present invention may all be carbon blacks conventionally used in pneumatic or non-pneumatic tires, or their treads (so-called pneumatic grade carbon blacks). Among the latter, particularly cited are the carbon blacks of reinforcement of the 100, 200, 300 series, or the carbon blacks of the 500, 600 or 700 series (ASTM grades) such as, for example, carbon blacks N115, N134, N234, N326, N330, N339, N347, N375, N550, N683, N772). These carbon blacks may be used in the isolated state, as commercially available, or in any other form, for example as a carrier for certain tire additives used. Carbon blacks could, for example, already be incorporated into the diene elastomer, notably isoprene in the form of a masterbatch (see, for example, applications WO 97 / 36724 or WO 99 / 16600).Mixtures of various carbon blacks may also be used at the prescribed rates.

[0047] As examples of organic fillers besides carbon blacks, one can cite functionalized polyvinyl organic fillers, such as those described in Petition 870220073015, dated 08 / 15 / 2022, p. 22 / 45 11 / 29 applications WO 2006 / 069792, WO 2006 / 069793, WO 2008 / 003434 and WO 2008 / 003435.

[0048] Advantageously, the specific surface area BET of carbon black is at least 90 m2 / g, preferably between 100 and 150 m2 / g. The specific surface area BET of carbon blacks is measured according to ASTM D6556-10 [multi-point method (minimum 5 points) - gas: nitrogen - relative pressure range P / P0: 0.1 to 0.3].

[0049] Carbon black advantageously exhibits a COAN oil absorption number greater than or equal to 90 ml / 100 g. The COAN, or Compressed Oil Absorption Number, of carbon blacks is measured according to ASTM D3493-16.

[0050] Advantageously, the carbon black content (if there is one or more) in the composition according to the invention is comprised in a range of 15 to 55 phr, preferably 30 to 50 phr.

[0051] The silicas usable within the scope of the present invention may be any silica known to those skilled in the art, notably any precipitated or pyrogenated silica exhibiting a BET surface area as well as a specific CTAB surface area, both of which are less than 450 m2 / g, preferably from 30 to 400 m2 / g. It may also be a mixture of different silicas, provided that they are used at the prescribed rates.

[0052] The BET specific surface area of ​​silica is determined by gas adsorption using the Brunauer-Emmett-Teller method described in The Journal of the American Chemical Society (Vol. 60, page 309, February 1938), and more precisely according to a method adapted from the NF ISO 5794-1 standard, Annex E of June 2010 [volumetric multipoint method (5 points) - gas: nitrogen - vacuum degassing: one hour at 160 °C - relative pressure range p / po: 0.05 to 0.17].

[0053] The specific surface area values ​​CT AB of silica were determined according to the standard NF ISO 5794-1, Annex G of June 2010. The method is based on the adsorption of CTAB (N-hexadecyl-N,N,N-trimethylammonium bromide) on the outer surface of the reinforcing filler. Petition 870220073015, dated 08 / 15 / 2022, page 23 / 45 12 / 29

[0054] The silicas usable within the scope of the present invention advantageously have a specific surface area BET of less than 250 m2 / ge / or a specific surface area CTAB of less than 220 m2 / g, preferably a specific surface area BET comprised in a range of 125 to 200 m2 / ge / or a specific surface area CTAB comprised in a range of 140 to 170 m2 / g.

[0055] Examples of silicas usable within the scope of the present invention include, for instance, the highly dispersible precipitated silicas (so-called “HDS”) Ultrasil 7000 and Ultrasil 7005 from Evonik, the Zeosil 1165MP, 1135MP and 1115MP silicas from Rhodia, the Hi-Sil EZ150G silica from PPG, the Zeopol 8715, 8745 and 8755 silicas from Huber, and silicas with a high specific surface area, as described in application WO 03 / 016387.

[0056] Advantageously, the silica content (if there is one or more) in the composition according to the invention is comprised in a range of 5 to 25 phr, preferably 6 to 20 phr.

[0057] To couple the reinforcing silica to the diene elastomer, a coupling agent (or bonding agent) that is at least bifunctional can be used in a well-known manner, designed to ensure a sufficient chemical and / or physical connection between the silica (the surface of its particles) and the diene elastomer (hereinafter simply referred to as the coupling agent). In particular, at least bifunctional organosilanes or polyorganosiloxanes are used. By bifunctional, it is understood a compound that has a first functional group capable of interacting with the inorganic filler and a second functional group capable of interacting with the diene elastomer.For example, such a bifunctional compound may comprise a first functional group comprising a silicon atom, said first functional group being able to interact with the hydroxyl groups of an inorganic filler, and a second functional group comprising a sulfur atom, said second functional group being able to interact with the diene elastomer.

[0058] Those skilled in the art may find examples of coupling agents in the following documents: WO 02 / 083782, WO 02 / 30939, WO 02 / 31041, WO Petition 870220073015, dated 08 / 15 / 2022, page 24 / 45 13 / 29 2007 / 061550, WO 2006 / 125532, WO 2006 / 125533, WO 2006 / 125534, US 6,849,754, WO 99 / 09036, WO 2006 / 023815, WO 2007 / 098080, WO 2010 / 072685 and WO 2008 / 055986.

[0059] However, it is advantageous within the scope of the present invention not to use a coupling agent. Thus, preferably, the content of coupling agent in the composition according to the invention is advantageously less than 6% by weight relative to the weight of silica, preferably less than 2%, preferably less than 1% by weight relative to the weight of silica. Preferably also, the composition according to the invention does not comprise a coupling agent.

[0060] Furthermore, when the composition according to the invention comprises silica, the composition advantageously comprises a silica recovery agent. Among the silica recovery agents, one can mention, for example, hydroxysilanes or hydrolyzable silanes, such as hydroxysilanes (see, for example, WO 2009 / 062733), alkylacoxysilanes, notably alkyltriethoxysilanes such as, for example, 1-octyl-triethoxysilane, polyols (e.g., diols or triols), polyethers (e.g., polyethylene glycols), primary, secondary or tertiary amines (e.g., trialcanolamines), a guanidine that may be substituted, notably difernylguanidine, hydroxylated or hydrolyzable polyorganosiloxanes (e.g., α,ω-dihydroxy-polyorganosilanes (notably α,ω-dihydroxypolydimethylsiloxanes) (see, for example, EP 0 784 072), fatty acids such as, for example, the acid stearic.When a silica recovery agent is used, it is used at a rate between 0 and 5 phr. Preferably, the silica recovery agent is a polyethylene glycol. The rate of silica recovery agent, preferably polyethylene glycol, in the composition according to the invention is advantageously comprised in a range of 1 to 6 phr, preferably 1.5 to 4 phr.

[0061] Advantageously, the total carbon black and silica content in the composition according to the invention is comprised in a range of 15 to 90 phr, preferably 20 to 70 phr.

[0062] Advantageously, carbon black represents 60% to 90% by weight of Petition 870220073015, dated 08 / 15 / 2022, page 25 / 45 14 / 29 preference of 65% to 80% by weight, in relation to the total weight of carbon black and silica.

[0063] The composition according to the invention also has the essential characteristic of comprising a polyethylene having a melting temperature between 120 °C and 160 °C, hereinafter referred to as polyethylene for the sake of simplicity. The melting temperature is measured in a well-known manner by DSC in accordance with ASTM D3418 (2015).

[0064] Polyethylene means a polymer comprising mainly ethylene molecules. Preferably, the polyethylene (i.e., polyethylene having a melting point between 120 °C and 160 °C) comprises more than 50 mol%, preferably more than 75 mol%, and even more preferably more than 90 mol% of ethylene molecules.

[0065] Advantageously, the polyethylene does not comprise a polypropylene motif or comprises less than 10% by weight relative to the total weight of the polyethylene. Preferably, the polyethylene does not comprise a polypropylene motif.

[0066] Advantageously, polyethylene is chosen from the group consisting of high-density polyethylenes, low-density polyethylenes, linear low-density polyethylenes, medium-density polyethylenes, very high molecular weight polyethylenes, very low-density polyethylenes and mixtures of these polyethylenes.

[0067] Preferably, the polyethylene has a density in the range of 910 to 970 kg / m3, more preferably in the range of 940 to 965 kg / m3.

[0068] Preferably, the polyethylene has a melt flow index at 190 °C under 2.16 kg within a range of 0.1 to 25 g / 10 min, preferably within a range of 1 to 15 g / 10 min. The melt flow index can be measured according to ISO 1133.

[0069] Polyethylene may be a functionalized polyethylene that includes at least one functional group comprising at least one heteroatom selected from the group Petition 870220073015, dated 08 / 15 / 2022, p. 26 / 45 15 / 29 consisting of Si, N, O, S and Cl.

[0070] Advantageously, when polyethylene is functionalized, it is a polyethylene functionalized by a function chosen from the group consisting of maleic anhydride, epoxy, amine and acid functions, preferably by a maleic anhydride function.

[0071] The rate of polyethylene which has a melting temperature between 120 °C and 160 °C may be understood to be in a range of 3 to 40 phr, preferably 5 to 30 phr.

[0072] Advantageously, the total proportion of carbon black, silica and polyethylene having a melting point between 120 °C and 160 °C is comprised in the range of 20 to 90 phr, preferably 30 to 80 phr.

[0073] Advantageously, the volume fraction of the combination of carbon black, silica and polyethylene is comprised in the range of 10% to 40%, preferably 15% to 35%.

[0074] Advantageously, the total thermoplastic polymer content, that is, the sum of thermoplastic polymers, including polyethylene, is comprised in a range of 3 to 40 phr, preferably 5 to 30 phr. Particularly advantageously, the composition does not comprise any thermoplastic polymer other than polyethylene which has a melting temperature between 120 °C and 160 °C.

[0075] Usable polyethylene can be obtained by classic methods known as, notably, polymerization in the presence of metallocene catalysts. Following polymerization, the polyethylene is granulated without any crosslinking reaction. Non-functionalized and non-crosslinked polyethylenes are commercially available from manufacturers such as Dow Global Technologies, EXXONMOBIL, Silon, ENI.

[0076] As an example of commercially usable polyethylene, one can cite ERACLENE MP90U polyethylene from the company ENI or B5206 from the company SABIC, and as an example of functionalized polyethylene one can cite Exxelor™ PE 1040 from the company ExxonMobil or OREVAC 18302 from the company ARKEMA. II-A-3 NETTING SYSTEM Petition 870220073015, dated 08 / 15 / 2022, page 27 / 45 16 / 29

[0077] The crosslinking system may be any type of system known to those skilled in the art in the field of rubber compounds for tires. It may notably be sulfur-based and / or peroxide-based and / or bismaleimide-based.

[0078] Preferably, the crosslinking system is based on sulfur, and is then referred to as a vulcanization system. The sulfur can be provided in any form, notably in the form of molecular sulfur and / or a sulfur donor agent. At least one vulcanization accelerator is equally and preferably present, and optionally, preferably and equally, various known vulcanization activators can be used, such as zinc oxide, stearic acid or equivalent compounds such as stearic acid salts and transition metal salts, guanidine derivatives (in particular difernylguanidine), or known vulcanization retardants.

[0079] Sulfur is used at a preferred rate of between 0.5 and 12 phr, in particular between 1 and 10 phr. The vulcanization accelerator is used at a preferred rate of between 0.5 and 10 phr, more preferably between 0.5 and 5.0 phr.

[0080] Any compound capable of acting as a vulcanization accelerator for diene elastomers in the presence of sulfur can be used as an accelerator, notably thiazole-type accelerators, as well as their derivatives, sulfenamide-type accelerators, thiurams, dithiocarbamates, dithiophosphates, thioureas and xanthans. 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-tert-butyl-2-benzothiazyl sulfenamide (“TBBS”), N-tert-butyl-2-benzothiazyl sulfenimide (“TBSI”), tetrabenzylthiuram disulfide (“TBZTD”), zinc dibenzyldithiocarbamate (“ZBEC”), and mixtures of these compounds. II-A-4 POSSIBLE ADDITIVES

[0081] Rubber compositions may optionally include all or part of the common additives usually used in rubber compositions. Petition 870220073015, dated 08 / 15 / 2022, page 28 / 45 17 / 29 Pneumatic elastomers, such as plasticizers (such as plasticizing oils and / or plasticizing resins), pigments, protective agents such as antiozone waxes, chemical antiozonants, antioxidants, anti-fatigue agents, reinforcing resins (such as described, for example, in application WO 02 / 10269). It may also be preferable that the composition according to the invention does not comprise certain ingredients that could compromise the performance of the composition. Advantageously, the composition according to the invention does not comprise a foaming agent that could penalize the strength of the composition, degrade the abrasion resistance properties of the composition, etc. II-B PREPARATION METHOD

[0082] The present invention also relates to a method for preparing a composition for the manufacture of a rubber composition according to the invention, characterized in that it comprises the following steps: a) simultaneously or successively bringing into contact and mixing, in one or more times, at least one diene elastomer, a filler comprising carbon black and silica, wherein the carbon black represents 50% to 95% by weight relative to the total weight of carbon black and silica, and a polyethylene having a melting temperature between 120 °C and 160 °C, thermomechanically mixing the whole until reaching a maximum temperature T1 greater than or equal to the melting temperature of the polyethylene, b) lowering the temperature of the mixture obtained in step (a) to a maximum temperature T2 lower than the melting temperature of the polyethylene, and then incorporating a crosslinking system into the mixture and mixing the whole.

[0083] The nature and rates of carbon black diene elastomer, silica, optional coupling agent, polyethylene having a melting temperature between 120 °C and 160 °C, crosslinking system are as defined in point II-A above in their general embodiments, and advantageously in their preferred embodiments.

[0084] The method according to the invention can be carried out using two successive preparation phases according to a well-known general procedure. Petition 870220073015, dated 08 / 15 / 2022, page 29 / 45 18 / 29 by those skilled in the art: step (a) then constitutes a first phase of thermomechanical working or blending (perhaps described as a non-productive phase) at high temperature, up to a maximum temperature between 130 °C and 190 °C, preferably between 140 °C and 180 °C, followed by a second phase of mechanical working (perhaps described as a productive phase) (step (b) of the method according to the invention) at a lower temperature, typically below 110 °C, for example between 60 °C and 100 °C, a finishing phase during which the crosslinking system is incorporated. Such phases have been described, for example, in applications EP 0 501 227 A, EP 0 735 088 A, EP 0 810 258 A, WO 2000 / 05300 or WO 2000 / 05301.

[0085] The first (non-productive) phase can preferably be carried out in several thermomechanical stages. During the course of a first stage, at least one diene elastomer, at least one polyethylene having a melting temperature between 120 °C and 160 °C, carbon black, silica, at a temperature between 20 °C and 100 °C and preferably between 25 °C and 100 °C, is introduced into a suitable mixer, such as a common internal mixer. After a few minutes, preferably from 0.5 to 2 min., and an increase in temperature from 90 °C to 100 °C, the other ingredients (i.e., those that remain if not all are initially) can be added all at once or in parts, except for the crosslinking system, during a mixing in the range of 20 seconds for a few minutes.The total mixing time, in this non-productive phase, is preferably between 2 and 10 minutes at a temperature of 180 °C or less, and preferably 170 °C or less.

[0086] After the mixture thus obtained has cooled, the crosslinking system, preferably the vulcanization system, is then incorporated at low temperature (typically below 100 °C), usually in an external mixer, such as a mixer with cylinders; the whole thing is then mixed (production phase) for a few minutes, for example between 5 and 15 min.

[0087] The final composition thus obtained is then calendered, for example in the form of a sheet or plate, notably for laboratory characterization, or further extruded, to form, for example, a rubber profile. Petition 870220073015, dated 08 / 15 / 2022, pp. 30 / 45 19 / 29 is used for the manufacture of semi-finished products in order to obtain products such as a tire tread. These products can then be used for the manufacture of tires, according to techniques known to those skilled in the art.

[0088] Crosslinking (or cooking) is carried out in a known manner at a temperature generally between 100 °C and 200 °C, for example between 130 °C and 200 °C, under pressure, for a sufficient time which may vary, for example, between 5 and 90 min. depending notably on the cooking temperature, the crosslinking system adopted, and the crosslinking kinetics of the composition considered. Preferably, crosslinking is carried out at a temperature between 110 °C and 160 °C, preferably between 120 °C and 150 °C.

[0089] Polyethylene (whose melting point is between 120 °C and 160 °C) can be introduced in the solid state, as sold commercially, or in the liquid state. When polyethylene is introduced in liquid form, it is then necessary to carry out a complementary step of heating the polyethylene to a temperature above its melting point before it is brought into contact with the other constituents of step (a). However, it is preferable to introduce the polyethylene in the solid state.

[0090] According to the invention, the maximum temperature T1 is preferably at least 1 °C, preferably 2 °C, preferably 3 °C, preferably 4 °C, preferably 5 °C higher than the temperature of the polyethylene. Preferably, the maximum temperature T1 is 5 to 20 °C higher than the temperature of the polyethylene.

[0091] According to the invention, the maximum temperature T2 is preferably less than 120 °C, preferably less than 100 °C, and preferably even less than 90 °C. Preferably, the maximum temperature T2 is comprised within a range of 20 to 90 °C. II-C COMPOSITION SUSCEPTIBLE TO BE OBTAINED BY THE METHOD ACCORDING TO THE INVENTION AND PNEUMATIC

[0092] The present invention also relates to a rubber composition obtainable by a method in accordance with the invention. Petition 870220073015, dated 08 / 15 / 2022, p. 31 / 45 20 / 29 II-D RUBBER ARTICLE

[0093] The present invention also relates to a rubber article comprising a composition according to the invention, or a composition capable of being obtained by the method according to the invention.

[0094] Considering the improved cost-benefit ratio of performance within the scope of the present invention, the rubber article is advantageously chosen from the group consisting of pneumatic tires, non-pneumatic tires, tracks and conveyor belts.

[0095] More particularly, the invention also relates to a pneumatic or non-pneumatic tire having a tread comprising a composition according to the invention, or a composition obtainable by the method according to the invention.

[0096] The tread has a rolling surface with a pattern formed by a plurality of grooves that delimit raised elements (blocks, ribs) in order to generate edges of material, as well as cavities. These grooves represent a volume of cavities which, related to the total volume of the tread (including both the volume of raised elements and that of all the grooves) is expressed by a percentage designated in this document as "volume cavity ratio". A volume cavity ratio equal to zero indicates a tread without grooves or cavities.

[0097] The present invention is particularly well suited to tire treads intended for use on civil engineering, agricultural and heavy-duty vehicles, more particularly civil engineering vehicles whose tires are subjected to very specific restrictions, notably the stony ground on which they travel. Thus, advantageously, the pneumatic or non-pneumatic tire fitted with a tread comprising a composition according to the invention or a composition obtainable by the method according to the invention is a tire for civil engineering, agricultural or heavy-duty vehicles, preferably civil engineering vehicles. These tires are equipped with Petition 870220073015, dated 08 / 15 / 2022, pp. 32 / 45 21 / 29 tread patterns which, in relation to the tread thicknesses of tires for light vehicles, particularly passenger cars or light trucks, exhibit large thicknesses of rubber material. Typically, the used portion of the tread of a heavy-duty tire has a thickness of at least 15 mm, that of a civil engineering vehicle at least 30 mm, or even up to 120 mm. Thus, the tire tread according to the invention advantageously has one or more grooves whose average depth ranges from 15 to 120 mm, preferably 65 to 120 mm.

[0098] The pneumatic tires according to the invention may have a diameter in the range of 20 to 63 inches, preferably 35 to 63 inches.

[0099] Furthermore, the average volumetric cavity ratio in the tire tread assembly according to the invention can be comprised in a range of 5 to 40%, preferably 5 to 25%.

[00100] The invention also relates to a rubber caterpillar comprising at least one rubber element comprising a composition according to the invention or a composition obtainable by the method according to the invention, the at least one rubber element preferably being an endless rubber belt or a plurality of rubber wedges, as well as a rubber conveyor belt comprising a composition according to the invention, or a composition obtainable by the method according to the invention.

[00101] The invention relates to the tires and semi-finished products for tires previously described, the rubber articles, both in the raw state (i.e., before cooking) and in the cooked state (i.e., after crosslinking or vulcanization). III. PREFERRED MODES OF REALIZATION

[00102] In view of the foregoing, the preferred embodiments of the invention are described below: 1. Rubber composition based on at least one diene elastomer, 10 to 60 phr of carbon black, 5 to 30 phr of silica, a polyethylene that has Petition 870220073015, dated 08 / 15 / 2022, pp. 33 / 45 22 / 29 a melting temperature between 120 °C and 160 °C, and a crosslinking system in which carbon black represents 50% to 95% by weight relative to the total weight of carbon black and silica. 2. Composition, according to embodiment 1, in which the diene elastomer is chosen from the group consisting of polybutadienes, synthetic polyisoprenes, natural rubber, butadiene copolymers, isoprene copolymers and mixtures of these elastomers, preferably chosen from the group consisting of synthetic polyisoprenes, natural rubber and their mixtures. 3. Composition, according to embodiment 1, in which the diene elastomer comprises mainly at least one polyisoprene, preferably at least one epoxidized polyisoprene. 4. Composition, according to embodiment 1, in which the diene elastomer comprises mainly at least one epoxidized polyisoprene having an epoxidation molar ratio in the range of 5% to 85%. 5. Composition, according to embodiment 4, in which at least one epoxidized polyisoprene has an epoxidation molar ratio in the range of 40% to 80%, preferably 45% to 75%. 6. Composition, according to embodiment 4, in which at least one epoxidized polyisoprene has an epoxidation molar ratio in the range of 10% to less than 49%, preferably from 15% to less than 40%. 7. Composition, according to any of embodiments 4 to 6, in which the epoxidized polyisoprene has a Mooney viscosity (ML 1+4) at 100 °C measured in accordance with ASTM DI646 (1999) comprising a range of 30 to 150, preferably 40 to 150, more preferably 50 to 140. 8. Composition, according to any of embodiments 3 to 7, in which the rate of polyisoprene, preferably epoxidized polyisoprene, is comprised in a range of 50 to 100 phr, preferably 75 to 100 phr, more preferably 100 phr. 9. Composition, according to any of the previous embodiments, in which the carbon black content is comprised within a range of 15 to 55 Petition 870220073015, dated 08 / 15 / 2022, pages 34 / 45 23 / 29 phr, preferably 30 to 50 phr. 10. Composition, according to any of the preceding embodiments, in which the silica content is comprised in a range of 5 to 25 phr, preferably 6 to 20 phr. 11. The composition, according to any of the foregoing embodiments, does not comprise a coupling agent or comprises less than 6% by weight relative to the weight of silica, preferably less than 2% by weight relative to the weight of silica. 12. Composition, according to any of the preceding embodiments, does not comprise a coupling agent. 13. Composition, according to any of the preceding embodiments, in which the total carbon black and silica content is comprised within a range of 15 to 90 phr, preferably 20 to 70 phr. 14. Composition, according to any of the preceding embodiments, in which carbon black represents 60% to 90% by weight, preferably 65% ​​to 80% by weight, relative to the total weight of carbon black and silica. 15. A composition, according to any of the preceding embodiments, in which polyethylene is functionalized by a function chosen from the group consisting of maleic anhydride, epoxy, amine and acid functions, preferably by a maleic anhydride function. 16. Composition, according to any of the preceding embodiments, in which the polyethylene does not comprise a polypropylene motif or comprises less than 10% by weight relative to the total weight of the polyethylene. 17. Composition, according to any of the preceding embodiments, in which the proportion of polyethylene having a melting temperature between 120 °C and 160 °C is within a range of 3 to 40 phr, preferably 5 to 30 phr. 18. Composition, according to any of the preceding embodiments, in which the total proportion of carbon black, silica and polyethylene having a melting point between 120 °C and 160 °C is comprised in a Petition 870220073015, dated 08 / 15 / 2022, pages 35 / 45 24 / 29 dominance in the 20 to 90 phr range, preferably 30 to 80 phr. 19. Composition, according to any of the preceding embodiments, in which the volume fraction of the carbon black, silica and polyethylene mixture is comprised in a range of 10% to 40%, preferably 15% to 35%. 20. Composition, according to any of the preceding embodiments, in which the total thermoplastic polymer content is comprised in a range of 3 to 40 phr, preferably 5 to 30 phr. 21. A composition, according to any of the preceding embodiments, in which the composition does not comprise any thermoplastic polymer other than polyethylene having a melting temperature between 120 °C and 160 °C. 22. Method for preparing a composition according to any of embodiments 1 to 21, characterized in that it comprises the following steps: a) simultaneously or successively bringing into contact and mixing, in one or more times, at least one diene elastomer, a filler comprising carbon black and silica, wherein the carbon black represents 50% to 95% by weight relative to the total weight of carbon black and silica, and a polyethylene having a melting temperature between 120 °C and 160 °C, thermomechanically mixing the whole until reaching a maximum temperature T1 greater than or equal to the melting temperature of the polyethylene, b) lowering the temperature of the mixture obtained in step (a) to a maximum temperature T2 lower than the melting temperature of the polyethylene, and then incorporating a crosslinking system into the mixture and mixing the whole. 23. Method, according to embodiment 22, in which polyethylene is introduced in the solid state. 24. Method, according to embodiment 22 or 23, in which the maximum temperature T1 is 5 to 20 °C higher than the temperature of the polyethylene. 25. Method, according to any of the embodiments 22 to 24, in which the maximum temperature T2 is less than 120 °C, preferably less than 100 °C. 26. Rubber composition obtainable by the method according to any of the embodiments 22 to 25. Petition 870220073015, dated 08 / 15 / 2022, pp. 36 / 45 25 / 29 27. Rubber article comprising a composition as defined in any of embodiments 1 to 21 or 26. 28. Rubber article, according to embodiment 27, said article being chosen from the group consisting of pneumatic tires, non-pneumatic tires, tracks and conveyor belts. 29. Pneumatic or non-pneumatic tire having a tread comprising a composition as defined in any of embodiments 1 to 21 or 26. 30. Tire, according to embodiment 29, being a tire for a civil engineering, agricultural or heavy-duty vehicle, preferably a civil engineering vehicle. 31. Tire, according to embodiment 29 or 30, whose tread has one or more grooves whose average depth is within a range of 30 to 120 mm, preferably 45 to 75 mm. 32. Tire, according to any of embodiments 29 to 21, which has an average volumetric cavity rate in the entire tread area comprised in a range of 5 to 40%, preferably 5 to 25%. 33. Tire, according to any of embodiments 29 to 32, having a diameter within a range of 20 to 63 inches, preferably 35 to 63 inches. 34. A caterpillar comprising at least one rubber element comprising a composition as defined in any of embodiments 1 to 21 or 26. 35. Caterpillar, according to embodiment 34, in which at least one rubber element is an endless rubber belt or a plurality of rubber wedges. 36. Rubber conveyor belt comprising a composition as defined in any of embodiments 1 to 21 or 26. IV- EXAMPLES IV-1 MEASUREMENTS AND TESTS USED DYNAMIC PROPERTIES Petition 870220073015, dated 08 / 15 / 2022, pages 37 / 45 26 / 29

[00103] The dynamic properties G* and Max tan^) are measured in a viscoanalyzer (Metravib VA4000), according to ASTM D5992-96. The response of a vulcanized composite sample (cylindrical test tube, 2 mm thick and 79 mm2 cross-section), subjected to a sinusoidal load in alternating simple shear, at a frequency of 10 Hz, under normal temperature conditions (23 °C) according to ASTM D 1349-09, is recorded. A strain amplitude sweep is performed from 0.1% to 50% (forward cycle), and then from 50% to 0.1% (return cycle). In the return cycle, the value of the loss factor, denoted tan^)max, is recorded.

[00104] The hysteretic performance results (tan^)max at 23 °C) are expressed as a percentage on a basis of 100 relative to the control composition T1. A result greater than 100 indicates an improvement in hysteretic performance, or a decrease in hysteresis. CATERPILLAR TEST

[00105] This test is representative of resistance to damage. It consists of running a metal track mounted on an inflated pneumatic tire, fitted to the wheel and vehicle, with rubber wedges of a supplied composition attached, on a track filled with pebbles for a specified time. At the end of the course, the wedges are removed and the number of cuts visible to the naked eye on the surface is counted. The lower the number, the better the performance in resisting damage.

[00106] To perform this test, shims of different compositions were manufactured (see Table 1 below) according to the method described in point V1 above. To obtain a shim, the non-crosslinked composition obtained in point V1 was calendered to a thickness of 5.5 mm, cut from plates (2 of 260x120 mm, 2 of 250x100 mm and 2 of 235x90 mm) which were then stacked in a pyramidal manner. This block of 6 plates was then inserted into a pyramidal mold with a rectangular base of 260x120 mm and a flat top of 235x90 mm surface area, and baked at a temperature of 120 °C for 300 minutes at a pressure of 180 bar, thus allowing the crosslinking of the composition. Petition 870220073015, dated 08 / 15 / 2022, pages 38 / 45 27 / 29

[00107] The chocks were then mounted on two Caterpillar XTRACK10 metal tracks, which were themselves mounted on two MICHELIN XMINE D2 12.00R24 tires from the rear axle of a SCANIA R410 truck. The tires were cut to support the tracks. The tires were inflated to a pressure of 7 bar and carried a load of 4,250 kg per tire.

[00108] The truck traveled along a level track covered with 30 / 60 porphyry pebbles obtained from SONVOLES Murcia, Spain, for 5 hours at a speed of 5 km / h. The density of pebbles on the track was approximately 1000 to 1500 pebbles per square meter.

[00109] At the end of the test, the visible cuts on the surface of the shims were counted. The average result was taken from a base of 6 shims. The performance results against aggression are expressed as a percentage based on 100 in relation to the control composition T1. A result greater than 100 indicates improved resistance to aggression. IV-2 PREPARATION OF COMPOSITIONS

[00110] In the following examples, the rubber compounds were made as described in point II-B above. In particular, the non-productive phase was carried out in a 0.4 liter mixer for 8 minutes, at an average paddle speed of 50 revolutions per minute until a maximum drop temperature of 165 °C was reached. The productive phase was carried out in a cylinder tool at 23 °C for 5 minutes.

[00111] The crosslinking of the composition was carried out at a temperature between 130 °C and 200 °C, under pressure. IV-3 RUBBER COMPOSITION TESTS

[00112] The examples presented below aim to compare the cost-benefit ratio of performance between resistance to mechanical aggression and hysteresis of four compositions conforming to the present invention (C1 to C3) with two control compositions (T1 and T2).

[00113] The formulations tested all contain an elastomeric matrix and a Petition 870220073015, dated 08 / 15 / 2022, pages 39 / 45 28 / 29 load system whose natures and contents are presented in Table 1 below, as well as 1 phr of antiozone wax (VARAZON 4959 from Sasol Wax), 1.5 phr of antioxidant (N-1,3-dimethylbutyl-N-phenylparaphenylenediamine, Santoflex 6-PPD from Llexsys), 1 phr of stearic acid (Pristerene 4931 from Uniqema), 2.5 phr of industrial grade zinc oxide (Umicore), 1 phr of 2,2,4-trimethyl-1,2-dihydroquinoline (Pilnox TMQ from Nocil), and 2.5 phr of polyethylene glycol CARBOWAX8000 from DOW CORNING, 1.5 phr of sulfur, and 1.1 phr of N-cyclohexyl-2-benzothiazolesulfenamide (Santocure CBS from the company Llexsys) as a vulcanization accelerator. The properties of these formulations are also presented in Table 1 below.

[00114] The T1 witness is a composition classically used in tire treads for civil engineering vehicles.

[00115] Compositions C1 and C2 differ from control T2 solely by the presence of polyethylene, which has a melting temperature between 120 °C and 160 °C. Composition C3 allows us to study the impact of the nature of the diene elastomer on the aforementioned cost-benefit ratio of performance. TABLE 1 T1 T2 C1 C2 C3 SBR(1) 100 - - - NR(2) - 100 100 100 - ENR50(3) - - - - 100 PE-1(4) - - 15 - PE-2(5) - - - 15 14 carbon black(6) 60 40 46 46 43 silica(7) - 15 17 17 16 Tan(d) 60 °C 100 176 115 125 115 Performance. caterpillar 100 85 198 191 234 (1) SBR tin functionalized solution with 5% polybutadiene motifs 1,2 - 29% styrene motifs - Tg = - 52 °C (2) natural rubber Petition 870220073015, dated 08 / 15 / 2022, pp. 40 / 45 29 / 29 (3) 50 molar epoxidized natural rubber (Epoxyprene 50 from Gurthrie) (4) PE-1: High-density polyethylene (HDPE) MP90 U from ENI Versalis (Tf = 137 °C) (5) PE-2: Exxelor™ PE 1040 maleic anhydride functionalized polyethylene from ExxonMobil (Tf = 134 °C) (6) NI 15 grade carbon black according to ASTM D-1765 (7) Evonik ULTRASIL VN3 silica

[00116] The results presented in Table 1 above show that the use of the filler system comprising a polyethylene having a melting temperature between 120 °C and 160 °C, carbon black and silica in accordance with the present invention allows for a significant improvement in resistance to aggression without penalizing hysteresis, or improving it.

Claims

1. Method for preparing a rubber composition based on at least one diene elastomer, 10 to 60 phr of carbon black, 5 to 30 phr of silica, a polyethylene having a melting point between 120 °C and 160 °C, and a crosslinking system, in which the carbon black represents 50% to 95% by weight relative to the total weight of carbon black and silica, characterized by comprising the following steps: a) contacting and mixing, simultaneously or successively, in one or more times, at least one diene elastomer, a filler comprising carbon black and silica, the carbon black representing 50% to 95% by weight relative to the total weight of carbon black and silica, and a polyethylene having a melting point between 120 °C and 160 °C, thermomechanically mixing the whole until reaching a maximum temperature T1 greater than or equal to the melting point of polyethylene,b) reduce the temperature of the mixture obtained in step (a) to a maximum temperature T2 below the melting point of polyethylene and then incorporate a crosslinking system into the mixture and blend the entire resulting mixture.

2. Method according to claim 1, characterized in that the diene elastomer is chosen from the group consisting of polybutadienes, synthetic polyisoprenes, natural rubber, butadiene copolymers, isoprene copolymers and mixtures of these elastomers, preferably chosen from the group consisting of synthetic polyisoprenes, natural rubber and their mixtures.

3. Method according to claim 1, characterized in that the diene elastomer comprises mainly at least one epoxidized polyisoprene having an epoxidation molar ratio in the range of 5% to 85%.

4. A method according to any one of claims 1 to 3, characterized in that the carbon black level is within a range of 15 to 55 phr, preferably 30 to 50 phr.

5. Method, according to any one of claims 1 to 4, characterized in that the silica content is comprised in a range of 5 to 25 phr, preferably 6 to 20 phr.

6. A method according to any one of claims 1 to 5, characterized in that it does not comprise a coupling agent or comprises less than 6% by weight relative to the weight of silica, preferably less than 2% by weight relative to the weight of silica.

7. A method according to any one of claims 1 to 6, characterized in that carbon black represents 60% to 90% by weight, preferably 65% ​​to 80% by weight, relative to the total weight of carbon black and silica.

8. A method according to any one of claims 1 to 7, characterized in that the polyethylene is functionalized by a function chosen from the group consisting of maleic anhydride, epoxy, amine and acid functions, preferably by a maleic anhydride function.

9. A method according to any one of claims 1 to 8, characterized in that the polyethylene does not comprise a polypropylene motif or comprises less than 10% by weight relative to the total weight of the polyethylene.

10. A method according to any one of claims 1 to 9, characterized in that the rate of polyethylene having a melting temperature between 120 °C and 160 °C is within a range of 3 to 40 phr, preferably 5 to 30 phr.

11. A method according to any one of claims 1 to 10, characterized in that the total content of carbon black, silica, and polyethylene having a melting temperature between 120 °C and 160 °C is within a range of 20 to 90 phr, preferably 30 to 80 phr.

12. Rubber composition characterized by being obtainable by means of the method as defined in any one of claims 1 to 11.

13. Rubber article characterized by comprising a composition, as defined in claim 12.

14. Rubber article according to claim 13, characterized in that the article is selected from the group consisting of pneumatic tires, non-pneumatic tires, conveyor belts and tracks.