PNEUMATIC

Abstract

The present invention relates to a tire, comprising two beads, at least one of the beads comprising a rubber composition based on: - at least one elastomer; - 60 to 100 parts per annum of reinforcing fillers, of which 15 to 70 parts per annum of pyrolysis carbon black and 15 to 60 parts per annum of carbon black with a total content of carbon black and pyrolysis carbon black ranging from 60 to 90 parts per annum; and - a crosslinking system.

Description

Title of the invention: PNEUMATIC FIELD OF INVENTION

[0001] The present invention relates to a tire, in particular for passenger vehicles. TECHNOLOGICAL BACKGROUND

[0002] Passenger vehicle tires usually include: - two ridges intended to come into contact with a mounting support; - two flanks extending the ridges radially outwards and joining in a top comprising a tread and a top reinforcement; - at least one carcass reinforcement extending radially in each side and axially in the top, radially internally to the top reinforcement.

[0003] Each bead comprises rubber compositions subjected to high stresses. They must therefore exhibit both a sufficient level of rigidity with good performance in terms of rolling resistance and be sufficiently cohesive in order to resist external physical aggressions such as during the mounting / dismounting of tires.

[0004] In a constant effort to improve tires and reduce their environmental footprint, manufacturers aim to develop new rubber compounds that meet, among other things, the criteria outlined above. One of the objectives of the present invention is therefore to provide a tire whose bead offers a good compromise between rigidity and tear resistance without compromising hysteresis, while incorporating a significant proportion of recycled material. BRIEF DESCRIPTION OF THE INVENTION

[0005] The present invention relates to a tire comprising two beads, at least one of the beads comprising a rubber composition based on:

[0006] - at least one elastomer;

[0007] - 60 to 100 parts per annum of reinforcing fillers, including 15 to 70 parts per annum of carbon black pyrolysis and 15 to 60 parts per million of carbon black, with a total carbon black and pyrolysis carbon black content ranging from 60 to 90 parts per million; and

[0008] - a crosslinking system.

[0009] Other aspects of the invention are as described below and in the claims. DEFINITIONS

[0010] The expression "composition based on" means a composition comprising the mixture and / or the in situ reaction product of the different constituents used, some of these constituents being able to react and / or being intended to react with each other, at least partially, during the different phases of manufacturing the composition; the composition can thus be in a totally or partially crosslinked state or in a non-crosslinked state.

[0011] The expression "part by weight per hundred parts by weight of elastomer" (or pce) is to be understood in the context of the present invention as the part, by mass per hundred parts by mass of elastomer or rubber, the two terms being synonymous.

[0012] In the present, unless expressly stated otherwise, all percentages (%) indicated are percentages (%) by mass.

[0013] On the other hand, any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​from greater than a to less than b (i.e., excluding the bounds a and b), while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​from a to b (i.e., including the strict bounds a and b). In the present case, when an interval of values ​​is described by the expression "from a to b", the interval represented by the expression "between a and b" is also and preferably described.

[0014] The term "radial" refers to a radius of the tire. It is in this sense that a point P1 is said to be "radially inside" a point P2 (or "radially inside" point P2) if it is closer to the axis of rotation of the tire than point P2. Conversely, a point P3 is said to be "radially outside" a point P4 (or "radially outside" point P4) if it is farther from the axis of rotation of the tire than point P4. We say that we are moving "radially inward (or outward)" when we are moving in the direction of smaller (or larger) radii. When referring to radial distances, this meaning of the term also applies.

[0015] By "radial cut" or "radial section" we mean here a cut or section along a plane which contains the axis of rotation of the tire.

[0016] An "axial" direction is a direction parallel to the axis of rotation of the tire. A point P5 is said to be "axially inside" a point P6 (or "axially inside" point P6) if it is closer to the median plane of the tire than point P6. Conversely, a point P7 is said to be "axially outside" a point P8 (or "axially outside" point P8) if it is farther from the median plane of the tire than point P8. The "median plane" of the tire is the plane that is perpendicular to the axis of rotation of the tire and that is equidistant from the annular reinforcing structures of each bead.

[0017] A "circumferential" direction is the direction which, in each cutting plane meridian, is perpendicular to both a radius of the tire and to the axial direction.

[0018] 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. This includes, in particular, polymers, plasticizers, fillers, etc. DETAILED DESCRIPTION OF THE INVENTION

[0019] The inventors have developed rubber compositions that meet the stated requirements.

[0020] Thus, the present invention relates to a tire comprising two beads, at least one of the beads comprising a rubber composition based on:

[0021] - at least one elastomer;

[0022] - 60 to 100 parts per annum of reinforcing fillers, including 15 to 70 parts per annum of carbon black pyrolysis and 15 to 60 parts per million of carbon black, with a total carbon black and pyrolysis carbon black content ranging from 60 to 90 parts per million; and

[0023] - a crosslinking system.

[0024] The rubber composition may further include rubber powders and / or common additives and processing agents.

[0025] The different constituents of the rubber composition can be as described below. Elastomer

[0026] The composition useful within the framework of the present invention is based on at least one elastomer (or indistinctly rubber).

[0027] The elastomer or each elastomer can be chosen from the group consisting of diene elastomers and mixtures thereof.

[0028] By "diene" elastomer, whether natural or synthetic, is to be understood in a known way as an elastomer consisting at least in part (i.e., a homopolymer or a copolymer) of diene monomer units (monomers bearing two carbon-carbon double bonds, conjugated or not).

[0029] 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 may be in particular described as "essentially saturated" diene elastomers (low or very low rate of diene origin motifs, always less than 15%).

[0030] The term "diene elastomer suitable for use" is specifically understood to mean:

[0031] (a) - any homopolymer obtained by polymerization of a diene monomer, conjugated or not, having from 4 to 18 carbon atoms;

[0032] (b) - any copolymer obtained by copolymerization of a diene, conjugated or not, having from 4 to 18 carbon atoms and at least one other monomer.

[0033] The other monomer may be ethylene, an olefin or a diene, conjugated or not.

[0034] Suitable conjugated dienes are those having from 4 to 12 atoms of carbon, in particular 1,3-dienes, such as 1,3-butadiene and isoprene.

[0035] Suitable olefins are vinylaromatic compounds having 8 to 20 carbon atoms and aliphatic α-monoolefins having 3 to 12 carbon atoms.

[0036] Suitable examples of vinylaromatic compounds include styrene, ortho-, meta-, para-methylstyrene, the commercial "vinyl-toluene" mixture, para-tert-butylstyrene.

[0037] As aliphatic α-monoolefins, α-monoolefins are particularly suitable acyclic aliphatics having from 3 to 18 carbon atoms.

[0038] More specifically, the diene elastomer that may be used in the compositions may be:

[0039] (a') - any homopolymer obtained by polymerization of a conjugated diene monomer having 4 to 12 carbon atoms;

[0040] (b') - any copolymer obtained by copolymerization of one or more dienes conjugated with each other or with one or more vinylaromatic compounds having 8 to 20 carbon atoms;

[0041] (c') - any copolymer obtained by copolymerization of one or more dienes, conjugated or not, with ethylene, an α-monoolefin or their mixture, such as for example elastomers obtained from ethylene, propylene with an unconjugated diene monomer of the aforementioned type.

[0042] Preferably, the diene elastomer is chosen from the group consisting of polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), butadiene copolymers, isoprene copolymers, and mixtures of these elastomers. Butadiene copolymers are particularly chosen from the group consisting of butadiene-styrene copolymers (SBR).

[0043] The diene elastomer can be modified, i.e. either coupled and / or star-shaped, or functionalized, or coupled and / or star-shaped and simultaneously functionalized.

[0044] Thus, the diene elastomer can be coupled and / or star-shaped, for example by means of a silicon or tin atom which links the elastomer chains together.

[0045] The diene elastomer can be simultaneously or alternatively functionalized and comprise at least one functional group. By functional group is meant a group comprising at least one heteroatom selected from Si, N, S, O, P. Particularly suitable as functional groups are those comprising at least one function such as: silanol, an alkoxysilane, a primary, secondary or tertiary amine, cyclic or non-cyclic, a thiol, an epoxide.

[0046] The rubber composition useful within the framework of the invention may contain a single diene elastomer or a mixture of several diene elastomers.

[0047] In certain embodiments, the rubber composition useful within the framework of the invention comprises one or more elastomers, it may thus comprise from 25 to 100 parts natural rubber and from 0 to 75 parts at least one polybutadiene, preferably from 35 to 75 parts natural rubber and from 25 to 65 parts at least one polybutadiene.

[0048] In certain embodiments, the rubber composition useful within the scope of the invention comprises, as an elastomer, a mixture of natural rubber (NR) and at least one polybutadiene (BR). Preferably, the mixture consists of 50 parts natural rubber (NR) and 50 parts polybutadiene (BR). Reinforcing load

[0049] The composition useful within the framework of the present invention comprises 60 to 100 pieces of reinforcing fillers.

[0050] The term "reinforcing filler" refers to any type of filler known for its ability to reinforce a rubber composition usable, in particular, for the manufacture of tires, for example, organic fillers such as carbon black or pyrolysis carbon black, or inorganic fillers such as silica or alumina. It is understood that rubber powders are not reinforcing fillers within the meaning of the present invention, and that any reinforcing fillers they may contain are not taken into account in calculating the total reinforcing filler content in the composition.

[0051] In particular, the composition useful within the scope of the present invention comprises 15 to 70 parts per million (ppm) of pyrolysis carbon black and 15 to 60 parts per million (ppm) of carbon black, with a total carbon black and pyrolysis carbon black content ranging from 60 to 90 ppm. The composition may further comprise an inorganic reinforcing filler (e.g., silica or alumina) or an organic reinforcing filler other than carbon black and pyrolysis carbon black, so as to achieve a total reinforcing filler content ranging from 60 to 100 ppm. Below 60 ppm of filler, the required level of stiffness is not achieved, and above 100 ppm of filler, industrial implementation is too difficult and the level of hysteresis is too high.

[0052] In some embodiments, the composition comprises 60 to 90 pieces, of Preferably, 60 to 80 parts per ton of reinforcing fillers, the reinforcing fillers being a mixture of carbon black and pyrolysis carbon black. It should be understood that the composition includes only carbon black and pyrolysis carbon black as reinforcing fillers (the composition therefore does not include inorganic or other organic reinforcing fillers). Preferably, the mixture then comprises 30 to 60 parts per ton of pyrolysis black and 20 to 40 parts per ton of carbon black.

[0053] The reinforcing charges can be as described below. Pyrolysis carbon black

[0054] The useful composition within the framework of the invention comprises 15 to 70 parts per annum of pyrolysis carbon black, preferably 30 to 60 parts per annum of pyrolysis carbon black.

[0055] For the purposes of this invention, "pyrolysis carbon black" means carbon black obtained by pyrolyzing a material comprising at least one carbon polymer and carbon black, hereinafter referred to as the material to be pyrolyzed, for example, in the context of recycling such a material. The physical state of the material to be pyrolyzed is irrelevant, whether it is in the form of powder, granules, strips, or any other form, and whether it is cross-linked or non-cross-linked.

[0056] Preferably, the material to be pyrolyzed can be recovered from manufactured articles or products generated during their manufacture / production (such as by-products or scrap); these manufactured articles can be selected from the group consisting of pneumatic tires, non-pneumatic tires, industrial conveyor belts, transmission belts, rubber seals, rubber hoses, shoe soles, and windshield wipers. More preferably still, the pyrolysis carbon black usable within the scope of the present invention is a carbon black obtained from a pyrolysis process in which the material to be pyrolyzed is derived from manufactured articles selected from the group consisting of pneumatic and non-pneumatic tires.

[0057] Pyrolysis in the context of the present invention means any type of thermal decomposition in the absence of oxygen, where the raw material is the material to be pyrolyzed as defined above. Pyrolysis carbon blacks are therefore distinguished from so-called industrial and / or ASTM grade carbon blacks in that the carbonaceous raw material used for pyrolysis is a material comprising at least one carbon polymer and a carbon black, and not materials derived from petroleum fractions, coal, or natural oils.

[0058] The pyrolysis carbon blacks usable within the framework of the present invention are distinguished from known carbon blacks such as industrial carbon blacks, in particular so-called "fumace" carbon blacks, notably by a higher ash content.

[0059] Preferably, the pyrolysis carbon black usable within the framework of the present invention has an ash content in the range of 5 to 30% by weight, more preferably in the range of 8 to 25% by weight, more preferably in the range of 10% to 22% by weight, relative to the total weight of the pyrolysis carbon black.

[0060] Preferably, the pyrolysis carbon black usable within the framework of the present invention has a sulfur content greater than 2% by weight, preferably 2.5 to 5% by weight, relative to the total weight of the pyrolysis carbon black.

[0061] Preferably, the pyrolysis carbon black usable within the framework of the present invention has a zinc content greater than or equal to 2% by weight, preferably 2.5 to 8% by weight, relative to the total weight of the pyrolysis carbon black.

[0062] Preferably, the pyrolysis carbon black usable within the framework of the present invention has a specific surface area STSA measured according to ASTM D 6556-2021 in the range of 20 to 200 m2 / g, more preferably in the range of 30 to 90 m2 / g.

[0063] Preferably, the pyrolysis carbon black usable within the framework of the present invention has a void volume measured according to ASTM D7854-21 and at a pressure of 50 MPa within a range of 30 to 60 ml / 100g, more preferably within a range of 35 to 55 ml / 100g.

[0064] The ash content is determined by calcination in platinum capsules in a muffle furnace at 825°C according to the following protocol. One capsule is identified before each series of measurements and is tare weighted to the nearest 0.1 mg; its mass is denoted PO. Five grams of pyrolysis carbon black sample are introduced into the capsule and weighed precisely to the nearest 0.1 mg; this mass is denoted PI. The capsule and its contents are pre-calcined using a Bunsen burner until fumes appear and the product ignites. Once the product has completely burned, the capsule and its contents are placed in a muffle furnace heated to 825°C for 1 hour. After 1 hour, the capsule is removed from the furnace and immediately placed in a desiccator at room temperature. When the capsule and the ash have returned to room temperature, the capsule is weighed again to obtain mass P2.Finally, it is possible to obtain the ash content (% ash) using the formula below: .

[0065] [Math.l] P 2 - PO % ashes -------X 100 PI-PO

[0066] The zinc content in the pyrolysis carbon black is determined after calcination of the sample, followed by resuspension of the ash in an acidic medium and quantification by ICP-AES (Inductively coupled plasma atomic emission spectroscopy). The ash is obtained by following the protocol above. Approximately 100 mg of ash (test sample) is taken and placed in a PFA (perfluoroalkoxy) tube for a HotBlock hot plate. Then, 8 mL of 37% concentrated hydrochloric acid, 3 mL of 65% concentrated nitric acid, and 0.5 mL of 40% hydrofluoric acid are added. The tube is sealed with its stopper and heated at 130°C for 2 hours. After cooling, the contents are transferred with ultrapure water into a 100 mL PTFE (polytetrafluoroethylene) volumetric flask already containing 2 g of boric acid (to neutralize the hydrofluoric acid). Ultrapure water is then added to the calibration mark.The resulting solution is diluted 100-fold by taking 1 mL from a 100 mL PTFE flask previously containing 8 mL of 37% hydrochloric acid, 3 mL of 65% nitric acid, 0.5 mL of 40% hydrofluoric acid, and 2 g of boric acid. This diluted solution is then filtered through a 0.45 µm GHP syringe filter before being analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Prior to the analysis of the diluted solution, at least five standards are analyzed by ICP-AES at zinc concentrations of 0, 0.5, 1, 2, and 5 mg / L. These standards were prepared in 100 mL volumetric flasks by diluting a commercially available solution certified to a zinc concentration of 1 g / L. .

[0067] These volumetric flasks initially contain 8 mL of 37% concentrated hydrochloric acid, 3 mL of 65% concentrated nitric acid, 0.5 mL of 40% hydrofluoric acid, and 2 g of boric acid. The standard solutions are analyzed by ICP-AES at a wavelength of XZn = 202.613 nm. For each standard concentration (c), the zinc signal intensity IZn is plotted on a graph IZn = f(c), which corresponds to the calibration curve (of the type y = ax + b). The sample solution (diluted solution) of unknown concentration is then measured under the same conditions as the standards. The measured intensity is related to the concentration using the calibration curve obtained previously. The ash concentration [c] in mass % is thus obtained directly by the software, since the sample size and volume have been previously recorded. The concentration of zinc in pyrolysis black [c]black in mass % is obtained by the following equation:

[0068] [Math.2] [Cjiioii- Khendres * 100% Ashes

[0069] The determination of the sulfur content in pyrolysis carbon black is carried out using a LECO furnace. LECO sulfur analyzers are designed to measure, in particular, the sulfur content in organic and / or inorganic materials by combustion and non-dispersive infrared detection. Before measuring the sulfur content of the sample, the sampling chambers are cleaned and the furnace is calibrated. The LECO furnace pods are cleaned beforehand: the empty pod is then analyzed under the same conditions as the samples. The calibration curve is prepared using a commercial standard called "BBOT" with a purity greater than 99.99% and a guaranteed carbon (C), hydrogen (H), nitrogen (N), oxygen (O), and sulfur (S) content. This content is as follows: C%: 72.52%; H%: 6.09%; N%: 6.51%; O%: 7.43%; and S%: 7.44%. Approximately 10 ± 3, 20 ± 3, and 40 ± 3 mg of BBOT are weighed into a pod. The standard / pod assembly is introduced into the combustion furnace, regulated at 1350 °C under pure oxygen. The combination of the furnace temperature and the analysis flow rate causes the sample to combust and release sulfur and / or carbon as SO2(g). After 20 seconds, oxygen begins to flow through the lance to accelerate the combustion of materials that are difficult to burn. The sulfur and / or carbon, as SO2(g), are carried by an oxygen flow through the infrared detection cells. The instrument software plots a line connecting the introduced standard mass and the observed response (area) on the detector. This yields a calibration curve. After thoroughly cleaning the sampling equipment, approximately 80 ± 5 mg of pyrolysis carbon black is weighed and introduced into a LECO furnace pod.The area of ​​the observed SO2 peak is related to the concentration using the calibration curve. The instrument's software then calculates the mass percentage of sulfur in the sample based on the mass of sample introduced into the capsule.

[0070] Pyrolysis carbon blacks are marketed for example by the company BlackBear under the reference “BBCT30” or by the company Scandinavian Enviro Systems under the reference “P550”. Carbon black

[0071] The composition useful within the framework of the invention comprises 15 to 60 parts per annum of carbon black, preferably 20 to 40 parts per annum of carbon black.

[0072] As suitable carbon blacks, all carbon blacks are suitable, including those conventionally used in tires or their treads, in particular industrial carbon blacks, more specifically so-called “furnace” carbon blacks.

[0073] Among carbon blacks, special mention should be made of reinforcing carbon blacks of the 100, 200, and 300 series, or blacks of the 500, 600, or 700 series (ASTM D-1765-2017 grades), such as NI 15, N134, N234, N326, N330, N339, N347, N375, N550, N683, and N772. Carbon blacks can be used in isolation, as commercially available, or in any other form, for example, as a carrier for certain rubber additives used. Carbon blacks could, for example, already be incorporated into the diene elastomer, particularly iso prenique in the form of a masterbatch (see for example requests WO 97 / 36724-A2 or WO 99 / 16600-A1). Reinforcing inorganic filler

[0074] The composition useful within the framework of the invention may include a reinforcing inorganic filler.

[0075] The term "reinforcing inorganic filler" herein means any inorganic or mineral filler, regardless of its color or origin (natural or synthetic), also called "white" filler, "light" filler, or even "non-black" filler (as opposed to carbon black), capable of reinforcing, on its own and without any other means than an intermediate coupling agent, a rubber composition intended for the manufacture of tires. As is known, certain reinforcing inorganic fillers can be characterized, in particular, by the presence of hydroxyl groups (-OH) on their surface.

[0076] Suitable inorganic reinforcing fillers include mineral fillers of the siliceous type, preferably silica (SiO2), or of the aluminous type, in particular alumina (Al2O3). The silica used may be any reinforcing silica known to those skilled in the art, in particular any precipitated or pyrogenated silica having a specific surface area BET and a specific surface area CT AB both less than 450 m2 / g, preferably in the range of 30 to 400 m2 / g, in particular 60 to 300 m2 / g.

[0077] 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. Examples include the silicas described in applications WO 03 / 016215-A1 and WO 03 / 016387-A1. Among the commercial HDS silicas, one can notably use the “Ulsil ® 5000GR”, “Ulsil ® 7000GR” silicas from the company Evonik, the “Zeosil ® 1085GR”, “Zeosil® 1115 MP”, “Zeosil® 1165MP”, “Zeosil® Premium 200MP”, “Zeosil® HRS 1200 MP” silicas from the Solvay Company.As non-HDS silica, the following commercial silicas may be used: “Ultrasil® VN2GR”, “Ultrasil® VN3GR” from Evonik, “Zeosil® 175GR” from Solvay, “Hi-Sil EZ120G(-D)”, “Hi-Sil EZ160G(-D)”, “Hi-Sil EZ200G(-D)”, “Hi-Sil 243LD”, “Hi-Sil 210”, “Hi-Sil HDP 320G” from PPG.

[0078] The specific surface area BET of silica is determined in a known manner by gas adsorption using the Brunauer-Emmett-Teller method described in "The Journal of the American Chemical Society" Vol. 60, page 309, February 1938, more precisely according to the French standard NF ISO 9277 of December 1996 (multipoint volumetric method (5 points) - gas: nitrogen - degassing: 1 hour at 160°C - range of relative pressure w / in: 0.05 to 0.17). The specific surface area CT AB of silica is determined according to the French standard NF T 45-007 of November 1987 (method B).

[0079] Other examples of inorganic fillers that may be used in compositions may also be cited mineral fillers of the aluminous type, in particular alumina (Al₂O₃), aluminum oxides, aluminum hydroxides, aluminosilicates, titanium oxides, silicon carbides or nitrides, all of the reinforcing type as described for example in applications WO 99 / 28376-A2, WO 00 / 73372-Al, WO 02 / 053634-A1, WO 2004 / 003067-A1, WO 2004 / 056915-A2, US 6 610 261-B1 and US 6 747 087-B2. Examples include the aluminas “Baikalox A125” or “CR125” (Baïkowski company), “APA-100RDX” (Condéa), “Aluminoxid C” (Evonik) or “AKP-G015” (Sumitomo Chemicals).

[0080] The physical state of the reinforcing inorganic filler is irrelevant, whether it is in the form of powder, microbeads, granules, or spheres, or any other suitable densified form. Of course, the term "reinforcing inorganic filler" also includes mixtures of different reinforcing inorganic fillers, particularly silicas as described above.

[0081] Those skilled in the art will understand that, in place of the inorganic reinforcing filler described above, a reinforcing filler of another nature could be used, provided that this reinforcing filler of another nature is coated with an inorganic layer such as silica, or has functional sites on its surface, particularly hydroxyl sites, requiring the use of a coupling agent to establish the bond between this reinforcing filler and the diene elastomer. Examples include carbon blacks partially or fully coated with silica, or carbon blacks modified with silica, such as, but not limited to, the "Ecoblack®" fillers of the CRX2000 series or the "CRX4000" series from Cabot Corporation.

[0082] A person skilled in the art will be able to adapt the total rate of reinforcing load according to the use concerned, in particular according to the type of tire concerned, for example tire for motorcycle, for passenger vehicle or for utility vehicle such as van or heavy goods vehicle.

[0083] To couple the reinforcing inorganic filler to the diene elastomer, a coupling agent (or bonding agent) that is at least bifunctional can be used in a well-known manner to ensure sufficient chemical and / or physical connection between the inorganic filler (surface of its particles) and the diene elastomer. Organosilanes or polyorganosiloxanes that are at least bifunctional are used in particular. "Bifunctional" means a compound having 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 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 charge and a second functional group comprising a sulfur atom, said second functional group being able to interact with the diene elastomer.

[0084] Preferably, the organosilanes are chosen from the group consisting of polysulfide organosilanes (symmetric or asymmetric) such as bis(3-triethoxysilylpropyl) tetrasulfide, abbreviated TESPT and marketed under the name "Si69" by Evonik, or bis-(triethoxysilylpropyl) disulfide, abbreviated TES PD and marketed under the name "Si75" by Evonik, polyorganosiloxanes, mercaptosilanes, and blocked mercaptosilanes, such as S-(3-(triethoxysilyl)propyl) octanethioate, marketed by Momentive under the name "NXT Silane". More preferably, the organosilane is a polysulfide organosilane.

[0085] Examples of coupling agents can be found by those skilled in the art in the following documents: WO 02 / 083782, WO 02 / 30939, WO 02 / 31041, WO 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.

[0086] The coupling agent content preferably represents 0.5% to 15% by weight relative to the amount of reinforcing inorganic filler, preferably 4% to 12%, and more preferably 6% to 10% by weight relative to the amount of reinforcing inorganic filler. Typically, the coupling agent content is less than 20%, preferably within a range of 6% to 17%, and preferably 8% to 15%. This percentage can easily be adjusted by those skilled in the art according to the percentage of inorganic filler used in the composition.

[0087] The composition may also contain, in addition to coupling agents, coupling activators, inorganic filler covering agents or more generally processing aids which are known to improve the dispersion of the filler in the rubber matrix and to lower the viscosity of the compositions, thereby improving their processing ability in the raw state, these agents being for example hydrolyzable silanes such as alkylalkoxysilanes (in particular alkyltriethoxysilanes), polyols, polyethers (for example polyethylene glycols), primary, secondary or tertiary amines (for example trialcanol-amines), hydroxylated or hydrolyzable POS, for example α,co-dihydroxy-polyorganosiloxanes (in particular α,co-dihydroxy-polydimethylsiloxanes), fatty acids such as stearic acid. Other organic charges

[0088] As an example of organic fillers other than carbon blacks and pyrolysis carbon blacks, we may cite the functionalized polyvinyl organic fillers as described in applications WO 2006 / 069792-A1, WO 2006 / 069793-A1, WO 2008 / 003434-Al and WO 2008 / 003435-Al. Rubber powder

[0089] The composition useful within the scope of the invention may include rubber powders (hereinafter referred to as "powder"). Thus, the composition typically comprises from 0 to 20 pieces of rubber powder.

[0090] In some embodiments, the composition does not include rubber powder.

[0091] In some embodiments, the composition comprises rubber powders whose content in the composition is greater than 0 pc and less than or equal to 20 pc, for example from 1 to 20 pc or from 10 to 20 pc.

[0092] The rubber powder is in the form of granules, possibly in the form of a rubber sheet. Most often, rubber powders are obtained by grinding or micronizing baked rubber compositions already used in a first application, for example in tires; they are a material recycling product. The rubber powder is therefore preferably composed of at least one elastomer and a filler. Preferably, the rubber powder is in the form of microparticles.

[0093] By "microparticles" we mean particles which have a size, namely their diameter in the case of spherical particles or their largest dimension in the case of anisometric particles, of a few tens or hundreds of microns. Powders are preferably composed of an elastomer and filler base. They may also include all the ingredients commonly used in rubber compositions such as plasticizers, antioxidants, vulcanizing additives, etc.

[0094] Thus, the powder comprises an elastomer, preferably a diene elastomer. This elastomer preferably represents at least 30% by mass, more preferably at least 35% by mass, and even more preferably at least 45% by mass of the weight of the powder, a percentage determined according to ASTM E131. It is preferably selected from the group consisting of polybutadienes, polyisoprenes including natural rubber, butadiene copolymers, and isoprene copolymers. More preferably, the molar content of diene-derived motifs (conjugated dienes) present in the diene elastomer is greater than 50%, preferably between 50% and 70%.

[0095] According to a preferred embodiment of the invention, the powder contains between 5 and 80% by mass of filler, more preferably between 10% and 75%, and very preferably between 15% and 70%.

[0096] The term "filler" here refers to any type of filler, whether reinforcing (typically nanometric particles, and preferably with a weight average size of less than 500 nm, in particular between 20 and 200 nm) or non-reinforcing or inert (typically micrometric particles, and preferably with a weight average size greater than 1 pm, for example between 2 and 200 pm). The weight average size of nanometric particles is measured in a manner well known to those skilled in the art (for example, according to WO 2009 / 083160, paragraph 1.1). The weight average size of micrometric particles can be determined by mechanical sieving.

[0097] Examples of fillers known to those skilled in the art to be reinforcing include carbon black or an inorganic reinforcing filler such as silica or alumina in the presence of a coupling agent, or mixtures thereof. According to a preferred embodiment of the invention, the powder comprises, as a filler, a reinforcing filler, in particular a carbon black or a mixture of carbon blacks.

[0098] Carbon black or a mixture of carbon blacks preferably constitutes more than 50%, more preferably more than 80%, and even more preferably more than 90% by mass of the reinforcing charge of the powder. In a more preferred embodiment, the reinforcing charge consists of carbon black or a mixture of carbon blacks.

[0099] Most preferably, carbon black is present in the powder at a rate of 20 to 40% by mass, more preferably 25 to 35% by mass.

[0100] All carbon blacks are suitable as carbon blacks, particularly those of the HAF, ISAF, SAF, FF, FEF, GPF, and SRF types conventionally used in tire rubber compounds (so-called tire-grade blacks). The powder may contain all other common additives used in rubber compounds, particularly tire compounds. These common additives include liquid or solid plasticizers, non-reinforcing fillers such as chalk and kaolin, preservatives, and vulcanizing agents. These additives may also be present in the powder as residues or derivatives, since they may have reacted during the manufacturing or crosslinking stages of the compound from which the powder is derived.

[0101] Regarding the constituents of the powder, it is preferred for the purposes of the invention that the powder has an acetone extract between 3 and 30% by mass, more preferably within a range of 5 to 25% by mass.

[0102] Also, it is preferable that the powder has a chloroform extract between 5 and 85% by mass, more preferably within a range of 5 to 50% by mass.

[0103] The powders may be simple rubber granules / micronized materials, without further treatment. It is also known that these powders may undergo treatment to modify them. This treatment may consist of a chemical modification for functionalization or devulcanization. It may also be a thermomechanical, thermochemical, biological treatment...

[0104] Grinding can be carried out using various technologies, including cryogenic impact micronization technologies that produce small particles in rubber materials. Commercial equipment such as the Netzsch CUM150 or Alpine CW250 mills can be used. According to a first embodiment of the invention, it is preferred to use a powder that has a morphology modified by thermal and / or mechanical, and / or biological and / or chemical treatment.

[0105] According to this first embodiment, it is preferred that the powder have an acetone extract of between 5 and 20% by mass, more preferably in the range of 10 to 18% by mass. It is also preferred that the powder have a chloroform extract of between 15 and 85% by mass, more preferably in the range of 15 to 50% by mass. Preferably, the chloroform extract of the rubber powder has a mass average molecular weight (Mw) greater than 10,000 g / mol, preferably greater than 20,000 g / mol, and more preferably greater than 30,000 g / mol.

[0106] According to the first embodiment, it is preferred that the ratio of chloroform extract to acetone extract, expressed as a mass percentage, be greater than or equal to 1.5; preferably greater than 2.

[0107] Preferably also according to this first embodiment, the powder has a Mooney viscosity (conventionally expressed in Mooney units, MU) between 40 and 90, preferably between 45 and 75 and more preferably between 50 and 70.

[0108] According to a second embodiment of the invention, it is possible to use a powder that has not undergone modification by thermal and / or mechanical, and / or biological and / or chemical treatment.

[0109] According to this second embodiment, it is preferred that the powder contain an acetone extract of between 3 and 15% by mass, more preferably in the range of 3 to 10% by mass. It is also preferred that the powder contain a chloroform extract of between 3 and 20% by mass, more preferably typically included in a range of 5 to 15% by mass. Preferably, the chloroform extract of the rubber powder has a mass average molecular weight (Mw) of less than 10000 g / mol, preferably less than 8000 g / mol.

[0110] According to the second embodiment, it is preferred that the ratio of the chloroform extract to the acetone extract, expressed as a mass percentage, be less than 1.5.

[0111] Preferably also according to this second embodiment, the powder has an average particle size (D50) between 10 and 400 µm, preferably between 50 and 350 µm and more preferably between 70 and 300 µm. Rubber powders useful for the needs of the invention are commercially available, for example under the trade name "PolyDyne" marketed by the company Lehigh Technologies. Crosslinking system

[0112] The composition useful within the framework of the invention comprises a crosslinking system.

[0113] The crosslinking system can be any type of system known to those skilled in the art in the field of tire rubber compositions. In particular, it can be based on sulfur, and / or peroxide, and / or bismaleimides.

[0114] Preferably, the crosslinking system is sulfur-based; this is referred to as a vulcanization system. The sulfur can be supplied in any form, including molecular sulfur or a sulfur-donating agent. At least one vulcanization accelerator is also preferably present, and optionally, various known vulcanization activators such as zinc oxide, stearic acid, or equivalent compounds such as stearic acid salts and transition metal salts, guanidine derivatives (in particular diphenylguanidine), or known vulcanization retardants may be used.

[0115] Sulfur is used at a preferential rate of between 0.5 and 10 parts per annum, in particular between 1 and 5 parts per annum. The vulcanization accelerator is used at a preferential rate of between 0.5 and 10 parts per annum, more preferably between 0.5 and 5.0 parts per annum.

[0116] Any compound capable of acting as a vulcanization accelerator for diene elastomers in the presence of sulfur may be used as an accelerator, in particular thiazole-type accelerators and their derivatives, sulfenamide, thiuram, dithiocarbamate, dithiophosphate, thiourea, and xanthate-type accelerators. Examples of such accelerators include, in particular, 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. Common additives and implementation agents

[0117] The useful composition within the scope of the invention may also include all or part of the usual additives and processing agents known to those skilled in the art and commonly used in tire rubber compositions, such as plasticizers (such as plasticizing oils and / or plasticizing resins with or without a tackifying character), non-reinforcing fillers, pigments, protective agents such as anti-ozone waxes, chemical anti-ozonants, antioxidants, anti-fatigue agents, reinforcing resins (such as described for example in application WO 02 / 10269).

[0118] In certain embodiments, the composition useful within the scope of the invention comprises a plasticizer. The plasticizer content is then greater than 0 and less than or equal to 10 parts per liter, for example from 1 to 5 parts per liter.

[0119] The plasticizer is preferably chosen from hydrocarbon resins, plasticizing oils, and mixtures thereof.

[0120] Particularly suitable are plasticizing oils selected from the group consisting of naphthenic oils (low or high viscosity, in particular hydrogenated or non-hydrogenated), paraffinic oils, MES (Medium Extracted Solvates) oils, TDAE (Treated Distillate Aromatic Extracts) oils, RAE (Residual Aromatic Extract) oils, TRAE (Treated Residual Aromatic Extract) oils and SRAE (Safety Residual Aromatic Extract) oils, mineral oils, vegetable oils, ether plasticizers, ester plasticizers, phosphate plasticizers, sulfonate plasticizers and mixtures of these compounds.

[0121] Hydrocarbon resins, also called hydrocarbon plasticizing resins, are polymers well known to those skilled in the art, essentially based on carbon and hydrogen but which may contain other types of atoms, for example oxygen, and which are particularly useful as plasticizing or tackifying agents in polymer matrices. By nature, they are at least partially 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").As is well known, these hydrocarbon resins can also be described as thermoplastic resins in that they soften when heated and can thus be molded.

[0122] The softening point of hydrocarbon resins is measured according to ISO 4625 (Ring and Bail method). The Tg is measured according to ASTM D3418 (1999). The macrostructure (Mw, Mn and Ip) of the hydrocarbon resin is determined by size exclusion chromatography (SEC): tetrahydrofuran solvent; temperature 35°C; concentration 1 g / L; flow rate 1 mL / min; solution filtered through a 0.45 µm porosity filter before injection; Moore calibration with polystyrene standards; set of 3 "WATERS" columns in series ("STYRAGEL" HR4E, HR1 and HR0.5); detection by differential refractometer ("WATERS 2410") and its associated operating software ("WATERS EMPOWER").

[0123] Hydrocarbon resins can be aliphatic, aromatic, or 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).

[0124] Suitable aromatic monomers include, for example, styrene, alpha-methylstyrene, indene, ortho-, meta-, para-methylstyrene, vinyl toluene, para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, vinylmesitylene, divynylbenzene, vinylnaphthalene, and any vinylaromatic monomer derived from a C9 cut (or more generally from a C8 to C10 cut). Preferably, the vinylaromatic monomer is styrene or a vinylaromatic monomer derived from a C9 cut (or more generally from a C8 to C10 cut). Preferably, the vinylaromatic monomer is the minor monomer, expressed as a mole fraction, in the copolymer under consideration.

[0125] According to a particularly preferred embodiment, the hydrocarbon plasticizing resin is chosen from the group consisting of cyclopentadiene (abbreviated CPD) or dicyclopentadiene (abbreviated DCPD) homopolymer or copolymer resins, terpene homopolymer or copolymer resins, terpene phenol homopolymer or copolymer resins, C5-cut homopolymer or copolymer resins, C9-cut homopolymer or copolymer resins, alpha-methyl-styrene homopolymer and copolymer resins and mixtures of these resins.

[0126] The term "terpene" here encompasses, as is known, the monomers alpha-pinene, beta-pinene, and limonene; the monomer limonene is known to exist in the form of three possible isomers: L-limonene (levorotatory enantiomer), D-limonene (dextrorotatory enantiomer), or dipentene, a racemic compound of the dextrorotatory and levorotatory enantiomers. Among the hydrocarbon plasticizing resins mentioned above, we will cite in particular resins of homo- or copolymers of alpha-pinene, beta-pinene, dipentene, or polylimonene.

[0127] As is known, high Tg hydrocarbon resins are hydro- resins carbonaceous, thermoplastics, whose Tg is greater than 20°C.

[0128] Preferably, the plasticizing resin is a high Tg hydrocarbon plasticizing resin having at least one of the following characteristics: - a Tg greater than 30°C; - an average number molecular mass (Mn) between 300 and 2000 g / mol, more preferably between 400 and 1500 g / mol; - a polymolecularity index (Ip) less than 3, more preferably less than 2 (reminder: Ip = Mw / Mn with Mw average molecular mass by weight).

[0129] More preferably, this high Tg hydrocarbon plasticizing resin exhibits all the above preferred characteristics.

[0130] The above-mentioned preferred high Tg hydrocarbon resins are well known to those skilled in the art and are commercially available, for example sold with regard to: - polylimonene resins: by the company DRT under the name "Dercolyte L120" (Mn=625 g / mol; Mw=1010 g / mol; Ip=l.6; Tg=72°C) or by the company ARIZONA under the name "Sylvagum TR7125C" (Mn=630 g / mol; Mw=950 g / mol; Ip=l.5; Tg=70°C); - C5 / vinylaromatic copolymer resins, in particular C5 / styrene or C5 / C9: by Neville Chemical Company under the names "Super Nevtac 78", "Super Nevtac 85" or "Super Nevtac 99", by Goodyear Chemicals under the name "Wingtack Extra", by Kolon under the names "Hikorez T1095" and "Hikorez Tl 100", by Exxon under the names "Escorez 2101" and "Escorez 1273"; - limonene / styrene copolymer resins: by DRT under the name "Dercolyte TS 105" of the DRT company, by ARIZONA Chemical Company under the names "ZT115LT" and "ZT5100".

[0131] As examples of other preferred resins, phenol-modified alpha-methylstyrene resins may also be mentioned. To characterize these phenol-modified resins, it should be noted that a known index called the "hydroxyl value" (measured according to ISO 4326 and expressed in mg KOH / g) is used. Alpha-methylstyrene resins, particularly phenol-modified ones, are well known to those skilled in the art and are commercially available, for example, sold by Arizona Chemical under the names "Sylvares SA 100" (Mn = 660 g / mol; Ip = 1.5; Tg = 53°C); "Sylvares SA 120" (Mn = 1030 g / mol; Ip = 1.9; Tg = 64°C); "Sylvares 540" (Mn = 620 g / mol; Ip = 1.3; Tg = 36°C; hydroxyl number = 56 mg KOH / g); "Silvares 600" (Mn = 850 g / mol; Ip = 1.4; Tg = 50°C; hydroxyl number = 31 mg KOH / g).

[0132] We can also mention resins of the alkyl-phenol family such as oc- tylphenyl formol (OPF) available for example under the name "SP 1068" from the company SI Group as well as gem rosin resins such as those supplied for example by the company Costa Irmaos. Composition manufacturing

[0133] The rubber composition useful within the scope of the invention is manufactured in suitable mixers, using two successive preparation phases well known to those skilled in the art: - a first thermomechanical working or mixing phase (the so-called "non-productive" phase), which can be carried out in a single thermomechanical step during which all the necessary constituents, including the elastomeric matrix, fillers, and any other miscellaneous additives, with the exception of the crosslinking system, are introduced into a suitable mixer such as a standard internal mixer (for example, of the 'Banbury' type). The incorporation of the filler into the elastomer can be carried out in one or more stages by thermomechanical mixing.In the case where the filler is already incorporated in whole or in part into the elastomer in the form of a masterbatch, as described for example in applications WO 97 / 36724 or WO 99 / 16600, it is the masterbatch which is directly mixed and where appropriate the other elastomers or fillers present in the composition which are not in the form of a masterbatch, as well as any other miscellaneous additives other than the crosslinking system, are incorporated.

[0134] The non-productive phase is carried out at high temperature, up to a maximum temperature between 130°C and 170°C, for a duration generally between 2 and 10 minutes. - a second mechanical working phase (the so-called "productive" phase), which is carried out in an external mixer such as a roller mixer, after cooling the mixture obtained during the first non-productive phase to a lower temperature, typically below 110°C, for example between 40°C and 100°C. The crosslinking system is then incorporated, and the whole is then mixed for a few minutes, for example between 1 and 30 min.

[0135] The final composition thus obtained is then 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 usable, for example, as an inner layer in a tire.

[0136] The composition may be either in its raw state (before crosslinking or vulcanization) or in its cured state (after crosslinking or vulcanization), and may be a semi-finished product which may to be used in a tire.

[0137] The crosslinking of the composition can be carried out in a manner known to those skilled in the art, for example at a temperature between 130°C and 200°C, preferably under pressure, for a sufficient time which can vary for example between 5 and 90 min.

[0138] The following examples are given for illustrative purposes only, but should in no way be considered as limiting the present invention. TIRES

[0139] The compositions described above are, according to the invention, particularly useful for inclusion in at least one of the tire beads and preferably in both tire beads.

[0140] The bead of a tire, designated in English as "Bead Zone" is one of the three main zones of a tire (top, sidewall, and bead).

[0141] More specifically, the bead is the portion of the tire designed to allow the tire to be attached to a mounting support, for example, a wheel including a rim. Thus, each bead is specifically designed to be in contact with a hook on the rim, enabling its attachment. Therefore, the bead can be radially delimited internally by the innermost radial point of the tire and radially delimited externally by the point on the outer surface of the tire bead that is radially outermost in contact with a tire measuring rim, according to the ETRTO (European Tyre and Rim Technical Organisation) standard manual, 2021, when the tire is inflated to its nominal pressure on that measuring rim.

[0142] In certain embodiments, the tire comprises a carcass reinforcement comprising at least one carcass layer anchored in each bead forming a wrap around a circumferential reinforcing element of each bead such that an axially inner portion of the carcass layer anchored in each bead is arranged axially inside an axially outer portion of the carcass layer anchored in each bead.

[0143] In these embodiments, the bead is subjected to relatively high stress from the carcass reinforcement due to the winding it forms there. Thus, in order to ensure sufficient resistance of the rubber composition in these particularly stressful embodiments, the rubber composition typically comprises several elastomers, in particular it may comprise from 25 to 60 parts per million of natural rubber and from 40 to 75 parts per million of at least one polybutadiene.

[0144] In other embodiments, the tire comprises a carcass reinforcement including at least one carcass layer anchored in each bead, each bead comprising an axially circumferential reinforcing element an axially arranged interior within the carcass layer anchored in each bead and an axially arranged external circumferential reinforcement element outside the carcass layer anchored in each bead.

[0145] In these other embodiments, the bead is subjected to relatively little stress from the carcass reinforcement due to its non-wrapping anchoring. Thus, the rubber composition in these other, less stressed embodiments advantageously comprises a higher proportion of natural rubber. The composition may therefore comprise one or more elastomers, in particular 40 to 100 parts per cent of natural rubber and 0 to 60 parts per cent of at least one polybutadiene.

[0146] In particularly advantageous embodiments, the bead or each bead includes a seat layer of the tire intended to be in contact with a tire mounting support when the tire is mounted on the mounting support, the seat layer comprising the rubber composition, preferably being made of the rubber composition described above.

[0147] In a conventional way, the mounting support is a rim.

[0148] Regardless of the embodiment described above, the base layer is arranged axially outside the circumferential reinforcement element(s). The base layer is therefore arranged axially between the circumferential reinforcement element(s) and the mounting support when the tire is mounted on this support.

[0149] As previously stated, tires, particularly for passenger vehicles, usually include: - two ridges intended to come into contact with a mounting support; - two flanks extending the ridges radially outwards and joining in a top comprising a tread and a top reinforcement; - at least one carcass reinforcement extending radially in each side and axially in the top, radially internally to the top reinforcement.

[0150] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which: - Figure 1 is a view, in a meridian cross-section parallel to the axis of rotation of the tire, of a tire according to a first embodiment, and - [Fig.2] is a view analogous to that of [Fig.1] of a tire according to a second embodiment.

[0151] In the figures relating to the tire, a coordinate system X, Y, Z has been represented. corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0152] In the figures relating to the tire, a reference frame X, Y, Z has been represented corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0153] Figure 1 shows a tire conforming to a first embodiment of the invention and designated by the general reference 10. The tire 10 has a substantially toric shape around an axis of revolution substantially parallel to the axial direction Y. The tire 10 is intended for a passenger vehicle.

[0154] The tire 10 includes a crown 12 comprising a tread 14 intended to come into contact with a ground during rolling and a crown reinforcement 16 extending into the crown 12 in the circumferential direction X. The tire 10 also includes an internal sealing layer 18 for an inflation gas intended to delimit an internal cavity with a mounting support for the tire 10 once the tire 10 is mounted on the mounting support, for example a rim, this cavity being intended to be pressurized by the inflation gas.

[0155] The tire 10 comprises two sidewalls 30 extending radially inwards from the top 12. The tire 10 further comprises two beads 32 radially inwards from the sidewalls 30. Each bead 32 is intended to come into contact with a mounting support. Each sidewall 30 connects each bead 32 to the apex 12. Thus, the two sidewalls 30 extend the beads 32 radially outwards and unite in the apex 12. Each bead 32 is radially delimited internally by the innermost radially 321 point of the tire 1. Each bead 32 is radially delimited externally by the point 322 of the outer surface SE of the outermost radially lateral bead 32 to be in contact with a measuring rim (not shown) of the tire according to the ETRTO (European Tyre and Rim Technical Organisation) standard manual, 2021 when the tire is inflated to its nominal pressure on this measuring rim.The radially innermost point 321 defines the radially inner end ERI of the bead 32 and point 322 defines the radially outer end ERE of the bead 32.

[0156] The tire 10 includes a carcass reinforcement 34. The crown reinforcement 16 is arranged radially between the tread 14 and the carcass reinforcement 34. The carcass reinforcement 34 includes at least one carcass layer 36, here a single carcass layer 36, anchored in each bead 32. The carcass layer 36 extends radially in each sidewall 30 and axially in the crown 12, radially inward to the crown reinforcement 16.

[0157] For the purpose of anchoring the carcass layer 36, the carcass layer 36 is anchored in each bead 32 by forming a wrap around a circumferential reinforcing element 35 of each bead 32, here a rod, so that an axially inner portion 361 of the carcass layer 36 anchored in each bead 32 is arranged axially inside an axially outer portion 362 of the carcass layer 36 anchored in each bead 32 and so that each axial end 363 axially delimiting the carcass layer 36 anchored in each bead 32 is arranged radially outside each circumferential reinforcing element 35.

[0158] Each bead 32 has a first layer 42, called the padding layer, extending radially outwards from each circumferential reinforcement element 35 and in contact with the carcass layer 36. The first layer 42 is arranged at least in part between the axially inner portion 361 and the axially outer portion 362.

[0159] Each bead 32 also includes a second layer 44, arranged axially outside the axially outer portion 362 and the first packing layer 42.

[0160] Each bead 32 also includes a third layer 46, referred to as the tire 10 seat layer. The third seat layer 46 is intended to be in contact with the tire mounting support 10 when the tire is mounted on this support. The third seat layer 46 is arranged axially on the outside of the circumferential reinforcing element 35 and more precisely axially between the circumferential reinforcing element 35 and the mounting support (not shown) when the tire is mounted on this support.

[0161] At least one of the first, second, and third layers 42, 44, 46 comprises, preferably is made of, a rubber composition according to the invention. In the illustrated example, the third base layer 46 is made of a rubber composition according to the invention. In particular, the rubber composition of the third base layer 46 comprises, notably, several elastomers, in particular it comprises 25 to 60 parts per unit of natural rubber and 40 to 75 parts per unit of at least one polybutadiene.

[0162] Figure 2 shows a tire according to a second embodiment of the invention. Elements analogous to those illustrated in Figure 1 are designated by identical reference numerals.

[0163] Unlike the tire according to the first embodiment, the tire 10 according to the second embodiment is such that, for the purpose of anchoring the carcass layer 36, the tire 10 comprises an axially internal circumferential reinforcing element 38 arranged axially inside the carcass layer 36 and an axially external circumferential reinforcing element 40 arranged axially outside the carcass layer 36. Here each reinforcing element 38, 40 comprises a continuous wire reinforcing element wound over several circumferential turns, for example as described in WO 2021 / 123522.

[0164] As with the first embodiment, at least one of the first, second, and third layers 42, 44, 46 comprises, preferably is made of, a rubber composition according to the invention. In the illustrated example, the third base layer 46 is made of a rubber composition according to the invention. In particular, the rubber composition of the third base layer 46 comprises, in particular, one or more elastomers, specifically it comprises from 40 to 100 parts per unit of natural rubber and from 0 to 60 parts per unit of at least one polybutadiene.

[0165] The tire according to the invention is intended for use on passenger vehicles, SUVs ("Sport Utility Vehicles"), two-wheeled vehicles (particularly motorcycles), aircraft, or industrial vehicles selected from among vans, "Heavy Goods Vehicles"—that is, subways, buses, road transport vehicles (trucks, tractors, trailers), off-road vehicles such as agricultural or construction equipment—and others. Preferably, the tire according to the invention is particularly suitable for use on passenger vehicles, vans, and SUVs.

[0166] The following examples are given for illustrative purposes only. They are not to be considered limiting to the present invention. EXAMPLES Measurement methods

[0167] Traction measurements:

[0168] Tensile tests allow the determination of the moduli of elasticity and the breaking properties and are based on the NF ISO 37 standard of December 2005.

[0169] The nominal secant modulus (or apparent stress, in MPa, related to the strain, which is dimensionless) is measured at 23 °C in second elongation (i.e. after an accommodation cycle at the elongation rate intended for the measurement itself) at 10% elongation (noted MA 10).

[0170] The tear resistance indices are measured at 23°C. Specifically, the force required to achieve fracture (in N / mm) is determined, and the strain at fracture (in %) is measured on a 10 x 85 x 2.5 mm specimen notched along its length with three notches to a depth of 5 mm, to induce fracture. The energy required to fracture the specimen, which is the product of the fracture force and the strain at fracture, can thus be determined.

[0171] The results are given in base 100, that is to say that the values ​​are expressed by ratio to a control, whose measured value is considered as the reference to 100.

[0172] Thus, a lower value of the energy at break represents a decrease in tear resistance performance (i.e. a decrease in the energy at break), while a higher value represents better performance.

[0173] Dynamic properties:

[0174] The dynamic properties G* and tan(φ)max are measured on a viscoelastic analyzer (Metravib V A4000) according to ASTM D 5992-96. The response of a vulcanized composition sample (cylindrical specimen 4 mm thick and with a cross-section of 400 mm²), subjected to a simple sinusoidal alternating shear stress at a frequency of 10 Hz, under varying temperature conditions, including 23°C, according to ASTM D 1349-99, is recorded. A peak-to-peak strain amplitude sweep is performed from 0.1% to 50% (forward cycle) and then from 50% to 1% (reverse cycle). The results used are the complex dynamic shear modulus (G*) and the loss factor (tan φ). The maximum value of tan ô observed (tan(ô)max) and the difference in complex modulus (AG*) between the values ​​at 0.1% and 50% strain (Payne effect) are shown for the return cycle.

[0175] The lower the value of tan(ô) at 23°C, the lower the hysteresis of the composition will be and therefore the lower the rolling resistance will be.

[0176] The results are expressed in terms of performance base 100, meaning that the value 100 is arbitrarily assigned to the control, and then the tan(φ) at 23°C (i.e., the hysteresis – and therefore the rolling resistance) of the different solutions tested is compared. The value base 100 is calculated using the following formula: (tan(φ) value at 23°C of the control / tan(φ) value at 23°C of the sample) * 100. Thus, a lower value represents a decrease in hysteresis performance (i.e., an increase in hysteresis), while a higher value represents better hysteresis performance (i.e., lower hysteresis). Preparation of compositions

[0177] The following tests are carried out as follows: the diene elastomer, the reinforcing filler, and the various other ingredients, with the exception of the vulcanization system, are successively introduced into an internal mixer (final filling rate: approximately 70% by volume), the initial tank temperature of which is approximately 70 °C. A thermomechanical process (non-productive phase) is then carried out in a single step, lasting approximately 3 to 4 minutes in total, until a maximum "drop" temperature of 165 °C is reached.

[0178] The mixture thus obtained is recovered, cooled, and then sulfur and an accelerator (sulfenamide) are incorporated on a mixer (homo-finisher) at 30°C, mixing everything (productive phase) for an appropriate time (for example between 5 and 12 min).

[0179] The compositions thus obtained are then calendered into plates (thickness of 2 to 3 mm) or thin sheets of rubber are then subjected to a baking step at 150°C for 25 min before their physical or mechanical properties are measured. Tests

[0180] Tests were carried out with different rubber compositions shown in Tables 1 and 2, based on natural rubber or a blend of natural rubber and polybutadiene.

[0181] Composition Tl corresponds to a classic composition used for the constitution of the bead.

[0182] Compositions Ex 1 to Ex 6 correspond to compositions useful within the framework of the present invention, with varying levels of carbon black and pyrolysis blacks, as well as with increasing levels of powder.

[0183] Compositions Ex 7 to Ex 10 correspond to compositions useful within the framework of the present invention, with varying levels of carbon black and pyrolysis blacks, with or without the presence of powder.

[0184] The compositions Ex 1 to Ex 10 are compositions advantageously useful with the tire conforming to the first embodiment described above.

[0185] Finally, compositions Ex 11 and 12 correspond to compositions useful within the scope of the present invention, containing a blend of carbon blacks and pyrolysis blacks, as well as powders with variations in the proportions of natural rubber and polybutadiene. These latter compositions are therefore not analytically comparable to the control composition T1 but demonstrate the performance gain on other elastomeric matrices.

[0186] The Ex 11 and Ex 12 compositions are advantageously useful compositions with the tire conforming to the second embodiment described above.

[0187] We then measure, after curing, i.e. after vulcanization, the elongation at break (AR), the breaking energy and the modulus of elasticity under tension at 10% elongation (MAi0) and the dynamic properties (G* at 10% elongation and tan delta max).

[0188] The properties of the compositions are presented in Tables 1 and 2.

[0189] [Tables 1] Tl Ex 1 Ex 2 Ex 3 Ex 4 Ex 5 Ex 6 NR(1) 50 50 50 50 50 50 50 BR (2) 50 50 50 50 50 50 50 Carbon Black (3) 65 35 35 50 35 20 35 Pyrolysis Black (4) 0 35 35 18 35 53 35 Rubber Powder (5) 0 6 10 15 15 15 20 Resin (7) 1 1 1 1 1 1 1 Antioxidants (8) 4 4 4 4 4 4 4 Ozone-fighting Wax (9) 1 1 1 1 1 1 1 Sulfur (10) 2.0 2.0 2.1 2.1 2.1 2.1 2.2 Stearic acid (11) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Accelerator (12) 1.1 1.1 1.2 1.2 1.2 1.2 1.2 Zinc oxide (13) 4 4 4 4 4 4 4 MA10 23°C (MPa) Base 100 100 98 95 95 96 100 98 G*10% 23°C (MPa) Base 100 100 91 96 95 94 93 95 Elongation at break AR 23°C (%) Base 100 100 227 226 214 221 208 217 Stress at break FR 23°C (N / mm) Base 100 100 223 208 198 208 192 204 Tear strength energy at 23°C (mJ) Base 100 100 396 470 424 458 401 444 Maximum delta tangent at 23°C Base 100 100 114 113 106 108 117 109

[0190] Table 1: Formulations (contents expressed in parts per annum) and properties of compositions Tl and Ex 1 to Ex 6.

[0191] (1) Natural rubber

[0192] (2) Polybutadiene

[0193] (3) Carbon black grade ASTM N550 - Cabot Corporation; BET (according to ASTM D6556-10): 39 m2 / g, CO AN: 85 ml / lOOg

[0194] (4) Pyrolysis Carbon Black P550 - Scandinavian Enviro Systems Company (ash (%): 18.5; sulfur (%): 3; zinc (%): 4.5; STSA specific surface area: 56 m2 / g (ASTM D6556-2021); void volume at 50MPa: 44ml / 100g (ASTM D7854-21))

[0195] (5) "PolyDyne" rubber powder - Lehigh Company; Granulometry (according to ASTM D5644-01): 60 mesh <12%

[0196] (7) Gem rosin

[0197] (8) Combination of two TMQ antioxidants ((N-(l,3-dimethylbutyl)-N-phenyl-para-phenylenediamine (“Santoflex 6-PPD” from Flexsys) and 2,2,4-trimethyl-l,2-dihydroquinolone (“TMQ” from Lanxess)

[0198] (9) Wax “Varazon 4959” - Sasol Company

[0199] (10) Sulfur

[0200] (11) Stearic acid “Pristerene 4931” - Uniqema

[0201] (12) N-ter-butyl-2-benzothiazyl sulfenamide ("Santocure TBBS") - Flexsys

[0202] (13) Industrial grade zinc oxide - Umicore Corporation

[0203] [Tables2] Tl Ex 7 Ex 8 Ex 9 ExlO Exil Exl2 NR(1) 50 50 50 50 50 70 100 BR (2) 50 50 50 50 50 30 0 Carbon Black (3) 65 37 21 37 21 34 36 Pyrolysis Black (4) 0 38 56 38 56 33 36 Rubber Powder (5) 0 0 0 15 15 15 15 Oil (6) 0 4 4 4 4 0 0 Resin (7) 1 2 2 2 2 5 5 Antioxidants (8) 4 4 4 4 4 4 4 Ozone-fighting Wax (9) 1 1 1 1 1 1 1 Sulfur (10) 2 2.2 2.2 2.4 2.4 2.7 2.7 Stearic acid (11) 1.5 1.5 1.5 1.5 1.5 3 3 Accelerator (12) 1.1 1.2 1.2 1.3 1.3 1.3 1.3 Zinc oxide (13) 4 4 4 4 4 4 4 MA10 23°C (MPa) Base 100 100 99 96 100 94 102 103 G*10% 23°C (MPa) Base 100 100 103 98 108 101 106 110 Elongation at break of tear resistance AR 23°C (%) Base 100 100 151 150 139 136 153 126 Tear-resistance strength at 23°C (N / mm) Base 100 100 131 120 118 107 138 126 Tear-resistance energy at 23°C (mJ) Base 100 100 198 180 163 146 211 159 Maximum delta tangent at 23°C Base 100 100 101 108 95 101 95 80

[0204] Table 2: Formulations (contents expressed in parts per annum) and properties of compositions Tl and Ex 7 to Ex 12.

[0205] (1) Natural rubber

[0206] (2) Polybutadiene

[0207] (3) Carbon black grade ASTM N550 - Cabot Corporation; BET (according to ASTM D6556-10): 39 m2 / g, CO AN: 85 ml / lOOg

[0208] (4) Pyrolysis Carbon Black P550 - Scandinavian Enviro Systems (ash (%): 18.5; sulfur (%): 3; zinc (%): 4.5; STSA specific surface area: 56 m2 / g (ASTM D6556-2021); void volume at 50MPa: 44ml / 100g (ASTM D7854-21))

[0209] (5) “PolyDyne” rubber powder – Lehigh Company; Particle size (according to ASTM D5644-01): 60 mesh <12%

[0210] (6) TDAE “VivaTec 500” oil - H&R Company

[0211] (7) Gem rosin

[0212] (8) Combination of two TMQ antioxidants ((N-(l,3-dimethylbutyl)-N-phenyl-para-phenylenediamine (“Santoflex 6-PPD” from Flexsys) and 2,2,4-trimethyl-l,2-dihydroquinolone (“TMQ” from Lanxess)

[0213] (9) “Varazon 4959” Wax - Sasol Company

[0214] (10) Sulfur

[0215] (11) Stearic acid “Pristerene 4931” - Uniqema

[0216] (12) N-ter-butyl-2-benzothiazyl sulfenamide ("Santocure TBBS") - Flexsys

[0217] (13) Industrial grade zinc oxide - Umicore Corporation

[0218] It can be observed that the compositions useful within the framework of the invention (Ex 1 to 10) exhibit the same stiffness / hysteresis compromise, or even a better stiffness / hysteresis compromise in the case of Ex 1 to 6, as the control composition (Tl), while exhibiting an improved tear-resistance breaking energy reflecting better material cohesion and resistance to aggression.

Claims

Demands

1. A tire comprising two beads, at least one of the beads comprising a rubber composition based on: - 25 to 100 parts per annum of natural rubber and 0 to 75 parts per annum of at least one polybutadiene; - 60 to 100 parts per annum of reinforcing fillers, of which 15 to 70 parts per annum of pyrolysis carbon black and 15 to 60 parts per annum of carbon black with a total content of carbon black and pyrolysis carbon black ranging from 60 to 90 parts per annum; and - a crosslinking system.

2. Pneumatic according to claim 1, wherein the composition comprises 60 to 80 pieces of reinforcing fillers, the reinforcing fillers being made up of a mixture of carbon black and pyrolysis carbon black.

3. Pneumatic according to the preceding claim, wherein the mixture of carbon black and pyrolysis carbon black comprises 20 to 40 parts carbon black and 30 to 60 parts pyrolysis carbon black.

4. Pneumatic according to any one of the preceding claims, wherein the pyrolysis carbon black has an ash content of 5 to 30% by weight, preferably 8 to 25% by weight, relative to the total weight of the pyrolysis carbon black.

5. Pneumatic according to any one of the preceding claims, wherein the pyrolysis carbon black has a sulfur content greater than 2% by weight, preferably from 2.5 to 5% by weight, relative to the total weight of the pyrolysis carbon black.

6. Pneumatic according to any one of the preceding claims, wherein the composition further comprises rubber powders, preferably in a content greater than 0 pc and less than or equal to 20 pc.

7. Pneumatic according to any one of the preceding claims, wherein the crosslinking system is a vulcanizing system based on molecular sulfur and / or a sulfur-donating agent, preferably the vulcanizing system comprises between 0.5 and 10 parts per annum of sulfur, preferably between 1 and 5 parts per annum.

8. Pneumatic according to any one of the preceding claims, wherein the composition further comprises one or more se- selected from the group consisting of plasticizers, non-reinforcing fillers, pigments, protective agents such as anti-ozone waxes, chemical anti-ozonants, antioxidants, anti-fatigue agents and reinforcing resins.

9. A tire according to any one of claims 1 to 8, comprising a carcass reinforcement including at least one carcass layer anchored in each bead forming a wrap around a circumferential reinforcing element of each bead such that an axially inner portion of the carcass layer anchored in each bead is arranged axially inside an axially outer portion of the carcass layer anchored in each bead.

10. Tire according to the preceding claim, wherein the rubber composition comprises 25 to 60 parts natural rubber and 40 to 75 parts at least one polybutadiene.

11. A tire according to any one of claims 1 to 8, comprising a carcass reinforcement including at least one carcass layer anchored in each bead, each bead comprising an axially internal circumferential reinforcing element arranged axially inside the carcass layer anchored in each bead and an axially external circumferential reinforcing element arranged axially outside the carcass layer anchored in each bead.

12. Pneumatic according to the preceding claim, wherein the rubber composition comprises from 40 to 100 parts natural rubber and from 0 to 60 parts at least one polybutadiene.

13. A tire according to any one of the preceding claims, wherein the bead or each bead comprises a seat layer 46 of the tire intended to be in contact with a mounting support of the tire when the tire is mounted on the mounting support, the seat layer 46 comprising the rubber composition, preferably being made of the rubber composition.

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