Tire

Abstract

The invention relates to a tyre (10) comprising, in the bead or tread, a rubber composition based on:-an elastomeric matrix comprising predominantly natural rubber by weight; -at least 65 phr of a reinforcing filler consisting of 40 phr to 70 phr of pyrolytic carbon black and 10 phr to 40 phr of carbon black, the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being from 0.60 to 0.75; -10 phr to 20 phr of a reinforcing resin mixture comprising a cardanol-based phenolic resin, the ratio of (the mass of the cardanol-based phenolic resin) / (the total mass of the reinforcing resin) being 0.1 to 0.7; -a hardener; and-a crosslinking system.

Description

Technical Field

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

[0002] Tires for passenger vehicles typically include:

[0003] - two beads intended to come into contact with the mounting support;

[0004] - two sidewalls extending radially outwards the beads and meeting in a crown comprising the tread and the crown reinforcement;

[0005] - At least one carcass reinforcement extending radially in each sidewall and axially in the crown, extending radially on the inside of the crown reinforcement.

[0006] Each bead comprises a rubber composition that is subject to high stresses and must have a high level of stiffness while providing reduced rolling resistance.

[0007] This problem also arises in tires having a tread comprising a radially outer layer intended to come into contact with the ground on which the tire runs when the tire is new and a radially inner layer arranged radially inside the radially outer layer when the tire is new. In particular, in certain tires it is advantageous for the radially inner layer to have a high level of stiffness while providing reduced rolling resistance.

[0008] Stiffness may be obtained by incorporating reinforcing fillers and / or reinforcing resins into the rubber composition.

[0009] In recent years, limiting the environmental impact of tire manufacturing and use has become a major challenge for manufacturers in this sector. The number of R&D activities to produce tires containing rubber compositions based on recycled or bio-based materials is increasing. The formulation of such compositions is not an easy task, the main difficulty being to reconcile good processability of the composition, a high level of stiffness and a low rolling resistance of the composition in the cured state.

[0010] Therefore, there is still a need to provide rubber compositions that reduce the environmental footprint of tires by incorporating recycled and / or bio-based materials and that satisfy a good stiffness / hysteresis / processability compromise, which compositions can in particular be incorporated into the beads or tread of a tire. Summary of the invention

[0011] The present invention relates to a tire comprising two beads, at least one of which comprises a rubber composition based on:

[0012] - an elastomeric matrix comprising mainly natural rubber by mass;

[0013] - at least 65 phr of reinforcing filler, the reinforcing filler consisting of 40 to 70 phr of pyrolytic carbon black and 10 to 40 phr of carbon black, the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being between 0.60 and 0.75;

[0014] - 10 to 20 phr of a reinforcing resin mixture, the reinforcing resin mixture comprising a phenolic resin based on cardanol, the ratio (mass of phenolic resin based on cardanol) / (total mass of reinforcing resin) being 0.1 to 0.7, preferably 0.2 to 0.6, more preferably 0.4 to 0.6;

[0015] - a curing agent; and

[0016] - Cross-linking system.

[0017] The invention also relates to a tire comprising a tread, the tread comprising:

[0018] - a radially outer layer intended to come into contact with the ground on which the tyre runs when the tyre is new, and

[0019] a radially inner layer which, when the tyre is new, is arranged radially inside the radially outer layer,

[0020] The radially inner layer comprises a rubber composition based on the following components:

[0021] - an elastomeric matrix comprising mainly natural rubber by mass;

[0022] - at least 65 phr of reinforcing filler, the reinforcing filler consisting of 40 to 70 phr of pyrolytic carbon black and 10 to 40 phr of carbon black, the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being between 0.60 and 0.75;

[0023] - 10 to 20 phr of a reinforcing resin mixture, the reinforcing resin mixture comprising a phenolic resin based on cardanol, the ratio (mass of phenolic resin based on cardanol) / (total mass of reinforcing resin) being 0.1 to 0.7, preferably 0.2 to 0.6, more preferably 0.4 to 0.6;

[0024] - a curing agent; and

[0025] - Cross-linking system.

[0026] Other aspects of the invention are described below and in the claims.

[0027] definition

[0028] The expression "composition based on" is understood to mean that the composition comprises a mixture and / or in situ reaction products of the various components used, some of which are capable of reacting and / or intended to react (at least partially) with one another during the various stages of the manufacture of the composition; the composition can therefore be in a completely or partially crosslinked state or in a non-crosslinked state.

[0029] The expression “parts by weight per 100 parts by weight of elastomer” (or phr) is understood to mean parts by mass per 100 parts by mass of elastomer or rubber, the two terms being synonymous.

[0030] The terms "elastomeric matrix" or "elastomeric matrix" mean all elastomers present in the rubber composition.

[0031] For the purposes of the present invention, the term "mainly" means that the compound is the main one among the compounds of the same type in the composition, that is, the compound is the one that accounts for the largest amount by mass among the compounds of the same type. In other words, the mass of the compound accounts for at least 51% of the total mass of the compounds of the same type in the composition. For example, in a system comprising only one elastomer, the elastomer is main within the meaning of the present invention, while in a system comprising two elastomers, the main elastomer accounts for more than half of the total elastomer mass, in other words, the mass of the elastomer accounts for at least 51% of the total elastomer mass. Similarly, a "main" filler is the filler that accounts for the largest mass among the fillers of the composition. In other words, the mass of the filler accounts for at least 51% of the total filler mass in the composition.

[0032] Herein, unless otherwise expressly stated, all percentages (%) shown are mass percentages (%).

[0033] In addition, any numerical interval represented by the expression "between a and b" represents a numerical range extending from greater than a to less than b (i.e., excluding the end values ​​a and b), while any numerical interval represented by the expression "a to b" means a numerical range extending from a to b (i.e., including the strict end values ​​a and b). Herein, when a numerical interval is described as the expression "a to b", it is also preferred to explain that the interval can be represented by the expression "between a and b".

[0034] The expression "radial" refers to the radius of the tire. In this sense, a point P1 is said to be "radially inside" (or "radially inside") a 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" (or "radially outside") a point P4 if it is further away from the axis of rotation of the tire than point P4. A movement is said to be "radially inwards (or outwards)" when the direction of the movement is the shorter (or longer) radius. This meaning of the terms also applies when radial distances are concerned.

[0035] The term "radial cross section" or "radial section" is understood here to be a cross section or section along a plane containing the axis of rotation of the tire.

[0036] The "axial" direction is the direction parallel to the axis of rotation of the tire. Point P5 is said to be "axially inside" (or "axially inside") of point P6 if point P5 is closer to the mid-plane of the tire than point P6. Conversely, point P7 is said to be "axially outside" (or "axially outside") of point P8 if point P7 is further away from the mid-plane of the tire than point P8. The "mid-plane" of the tire is the plane perpendicular to the axis of rotation of the tire and equidistant from the annular reinforcing structure of each bead.

[0037] The "circumferential" direction is the direction perpendicular to both the radius and the axial direction of the tire in each meridian cross-section.

[0038] The carbon-containing compounds mentioned in this specification can be compounds of fossil origin or bio-based origin. In the latter case, they can be produced in part or in whole from biomass, or can be obtained from renewable raw materials derived from biomass. In particular, they relate to polymers, plasticizers, fillers, etc. DETAILED DESCRIPTION OF THE INVENTION

[0040] The inventors have developed a rubber composition that meets the above requirements. The composition has good processability and can therefore achieve a satisfactory stiffness / rolling resistance compromise.

[0041] The present invention therefore relates to a tire (10) comprising in the beads or in the tread a rubber composition as described below.

[0042] More specifically, the present invention relates to a tire comprising two beads, at least one of which comprises a rubber composition based on:

[0043] - an elastomeric matrix comprising mainly natural rubber by mass;

[0044] - at least 65 phr of reinforcing filler, the reinforcing filler consisting of 40 to 70 phr of pyrolytic carbon black and 10 to 40 phr of carbon black, the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being between 0.60 and 0.75;

[0045] - 10 to 20 phr of a reinforcing resin mixture, the reinforcing resin mixture comprising a phenolic resin based on cardanol, the ratio (mass of phenolic resin based on cardanol) / (total mass of reinforcing resin) being 0.1 to 0.7, preferably 0.2 to 0.6, more preferably 0.4 to 0.6;

[0046] - a curing agent; and

[0047] - Cross-linking system.

[0048] The invention also relates to a tire comprising a tread, the tread comprising:

[0049] - a radially outer layer intended to come into contact with the ground on which the tyre runs when the tyre is new, and

[0050] a radially inner layer which, when the tyre is new, is arranged radially inside the radially outer layer,

[0051] The radially inner layer comprises a rubber composition based on the following components:

[0052] - an elastomeric matrix comprising mainly natural rubber by mass;

[0053] - at least 65 phr of reinforcing filler, the reinforcing filler consisting of 40 to 70 phr of pyrolytic carbon black and 10 to 40 phr of carbon black, the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being between 0.60 and 0.75;

[0054] - 10 to 20 phr of a reinforcing resin mixture, the reinforcing resin mixture comprising a phenolic resin based on cardanol, the ratio (mass of phenolic resin based on cardanol) / (total mass of reinforcing resin) being 0.1 to 0.7, preferably 0.2 to 0.6, more preferably 0.4 to 0.6;

[0055] - a curing agent; and

[0056] - Cross-linking system.

[0057] The rubber composition may also contain conventional additives and processing aids.

[0058] The various components of the rubber composition can be described as follows.

[0059] Elastomer matrix

[0060] The elastomeric matrix comprises mainly natural rubber by mass, generally from greater than 50 phr to 100 phr, preferably from 75 phr to 100 phr, of natural rubber.

[0061] The elastomeric matrix may comprise another elastomer chosen from diene elastomers and mixtures thereof.

[0062] The term “diene elastomer”, whether natural or synthetic, is understood in a known manner to mean an elastomer composed at least partly (ie homopolymer or copolymer) of diene monomer units (monomers carrying two conjugated or non-conjugated carbon-carbon double bonds).

[0063] These diene elastomers can be divided into two categories: “essentially unsaturated” or “essentially saturated”. The term “essentially unsaturated” generally refers to a diene elastomer derived at least partly from conjugated diene monomers and having a content of units of diene origin (conjugated dienes) greater than 15% (mol %); thus diene elastomers such as butyl rubber or EPDM-type copolymers of dienes with α-olefins do not come within the aforementioned definition but may in particular be referred to as “essentially saturated” diene elastomers (low or very low content of units of diene origin, always less than 15%).

[0064] The term "diene elastomer that can be used" means in particular:

[0065] (a) - any homopolymer obtained by the polymerization of conjugated or non-conjugated diene monomers containing 4 to 18 carbon atoms;

[0066] (b) - Any copolymer obtained by copolymerization of a conjugated or nonconjugated diene containing from 4 to 18 carbon atoms with at least one other monomer.

[0067] The other monomers may be ethylene, olefins or conjugated or non-conjugated dienes.

[0068] Suitable conjugated dienes include those containing from 4 to 12 carbon atoms, particularly 1,3-dienes, such as 1,3-butadiene and isoprene, among others.

[0069] Suitable olefins include vinyl aromatic compounds containing from 8 to 20 carbon atoms and aliphatic alpha-monoolefins containing from 3 to 12 carbon atoms.

[0070] Suitable vinylaromatic compounds include, for example, styrene, (o-, m- or p-)methylstyrene, the “vinyltoluene” commercial mixtures or p-(tert-butyl)styrene.

[0071] Suitable aliphatic alpha-monoolefins include especially non-cyclic aliphatic alpha-monoolefins containing from 3 to 18 carbon atoms.

[0072] More specifically, the diene elastomer that may be used in the composition may be:

[0073] (a') - any homopolymer obtained by polymerization of conjugated diene monomers containing 4 to 12 carbon atoms;

[0074] (b') - any copolymer obtained by copolymerizing one or more conjugated dienes with each other or with one or more vinyl aromatic compounds containing from 8 to 20 carbon atoms;

[0075] (c') - Any copolymer obtained by copolymerizing one or more conjugated or non-conjugated dienes with ethylene, alpha-monoolefins or mixtures thereof, for example elastomers obtained from ethylene, propylene and non-conjugated diene monomers of the abovementioned type.

[0076] Preferably, the diene elastomer is chosen from polybutadiene (BR), natural rubber (NR), synthetic polyisoprene (IR), butadiene copolymers, isoprene copolymers and mixtures of these elastomers. The butadiene copolymers are especially chosen from styrene / butadiene copolymers (SBR).

[0077] The diene elastomer may be modified, ie coupled and / or star-branched, or functionalized, or coupled and / or star-branched and simultaneously functionalized.

[0078] Thus, the diene elastomers may be coupled and / or star-branched, for example by means of silicon or tin atoms linking the elastomer chains together.

[0079] The diene elastomer may be functionalized simultaneously or alternately and comprise at least one functional group. The term "functional group" means a group comprising at least one heteroatom chosen from Si, N, S, O or P. Particularly suitable as functional groups are those comprising at least one function, for example: silanols, alkoxysilanes, cyclic or acyclic primary, secondary or tertiary amines, thiols or epoxides.

[0080] In certain embodiments, rubber compositions useful in the context of the present invention also include styrene / butadiene copolymers (SBR).

[0081] In certain embodiments, the rubber composition useful in the context of the present invention comprises an elastomeric matrix composed of natural rubber and styrene / butadiene copolymer (SBR), the natural rubber constituting a major mass of the elastomeric matrix.

[0082] In certain embodiments, rubber compositions useful in the context of the present invention include an elastomeric matrix composed of natural rubber (100 phr of natural rubber).

[0083] Reinforcement filler

[0084] The rubber composition usable in the context of the present invention comprises at least 65 phr, generally between 65 and 110 phr, of reinforcing filler, the reinforcing filler consisting of between 40 and 70 phr of pyrolytic carbon black and between 10 and 40 phr of carbon black (referred to as "conventional"), the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being between 0.60 and 0.75.

[0085] In certain embodiments, the reinforcing filler consists of 10 to 30 phr, preferably 20 to 30 phr, of carbon black (referred to as "conventional") and 40 to 65 phr, preferably 45 to 65 phr, of pyrolytic carbon black.

[0086] Pyrolytic Carbon Black

[0087] For the purposes of the present invention, the term "pyrolytic carbon black" refers to carbon black produced by a pyrolysis process of a material comprising at least a carbon-based polymer and carbon black (hereinafter referred to as the material to be pyrolyzed), for example in the case of recycling such a material. The physical state of the material to be pyrolyzed provided is not important, whether it is a powder, granules, strips or any other form, in a cross-linked or non-cross-linked state.

[0088] Preferably, the material to be pyrolyzed can be recovered from the article or from products (e.g. by-products or waste) generated during its manufacture / production; these articles can be selected from pneumatic tires, non-pneumatic tires, industrial conveyor belts, transmission belts, rubber seals, rubber hoses, shoe soles and windscreen wipers. Even more preferably, the pyrolytic carbon black that can be used in the context of the present invention is carbon black obtained from a pyrolysis process, wherein the material to be pyrolyzed originates from an article selected from pneumatic tires and non-pneumatic tires.

[0089] In the context of the present invention, "pyrolysis" refers to any type of thermal decomposition carried out in the absence of oxygen, the raw material of which is the material to be pyrolyzed as defined above. Thus, pyrolytic carbon black differs from "industrial" and / or "ASTM grade" carbon black in that the carbon-based raw material used for pyrolysis is a material comprising at least a carbon-based polymer and carbon black, rather than a material derived from petroleum fractions or from coal or from natural source oils.

[0090] Pyrolytic carbon blacks which can be used in the context of the present invention differ from known carbon blacks such as industrial carbon blacks, in particular "furnace" carbon blacks, in particular by their higher ash content.

[0091] Preferably, the ash content of the pyrolytic carbon black that can be used in the context of the present invention ranges from 5 to 30 wt. %, more preferably from 8 to 25 wt. %, even more preferably from 10 to 22 wt. %, relative to the total weight of the pyrolytic carbon black.

[0092] Preferably, the pyrolytic carbon black that can be used in the context of the present invention has a sulfur content of more than 2% by weight, preferably from 2.5% to 5% by weight, relative to the total weight of the pyrolytic carbon black.

[0093] Preferably, the pyrolytic carbon black that can be used in the context of the present invention has a zinc content of more than 2% by weight, preferably from 2.5% to 8% by weight, relative to the total weight of the pyrolytic carbon black.

[0094] Preferably, the pyrolytic carbon black that can be used in the context of the present invention has a carbon black content at 20 m / s measured according to standard ASTM D 6556-2021. 2 / g to 200m 2 / g range, more preferably 30 m 2 / g to 90m 2 / g range of STSA specific surface area.

[0095] Preferably, the pyrolytic carbon black that can be used in the context of the present invention has a void volume measured according to standard ASTM 7854 (2018) at a pressure of 50 MPa ranging from 30 to 60 ml / 100 g, more preferably from 35 to 55 ml / 100 g.

[0096] The ash content is determined by calcination in a platinum dish in a muffle furnace at 825°C according to the following protocol. Before each series of measurements, one dish is pre-determined and tared to within 0.1 mg, the mass being denoted P0. 5 grams of the pyrolytic carbon black sample is placed in the dish and accurately weighed to within 0.1 mg; this mass is denoted P1. The dish and its contents are pre-calcined using a Bunsen burner until smoke appears and the product ignites. Once the product has been completely burned, the dish and its contents are placed in a muffle furnace heated to 825°C for 1 hour. After 1 hour, the dish is removed from the furnace and immediately placed in a desiccator at room temperature. When the dish and ash have returned to ambient temperature, the dish is weighed again to obtain the mass P2. Finally, the ash content (% ash) can be obtained using the following formula:

[0097]

[0098] After the sample is calcined, the ash is then absorbed into an acidic medium and measured by ICP-AES (inductively coupled plasma atomic emission spectrometry) to determine the zinc content in the pyrolytic carbon black. The ash is obtained by executing the above protocol. Take approximately exactly 100 mg of ash (test sample) and introduce it into a PFA (perfluoroalkoxy) tube for a HotBlock heating plate. Then add 8 ml of 37% concentrated hydrochloric acid, 3 ml of 65% concentrated nitric acid and 0.5 ml of 40% hydrofluoric acid. Seal the tube with a stopper and heat at 130°C for 2 hours. After cooling, use ultrapure water to transfer the contents to a 100 ml PTFE (polytetrafluoroethylene) volumetric flask that already contains 2 grams of boric acid (for neutralizing hydrofluoric acid). Add ultrapure water until the scale line. The resulting solution was diluted 100 times by taking 1 ml of the solution and placing it in a 100 ml PFTE bottle already containing 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 diluted solution was then filtered on a 0.45 μm GHP syringe filter and then analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Prior to analyzing the diluted solution, at least 5 standards were analyzed by ICP-AES at 0, 0.5, 1, 2 and 5 mg / L zinc concentrations. These standards were prepared by diluting a commercial solution with a certified zinc concentration of 1 g / L using a 100 ml volumetric flask.

[0099] These volumetric flasks already 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 wavelength λZn=202.613 nm). For each standard concentration (c), the intensity of the zinc signal IZn is plotted on the graph IZn=f(c), which corresponds to the calibration curve (type y=ax+b). Sample solutions of unknown concentration (diluted solutions) are then measured under the same conditions as the standards. The measured intensities are linked to the concentrations by means of the previously obtained calibration curve. Since the test sample and volume have been recorded in advance, the ash concentration [c] expressed in mass % is obtained directly by the software. The concentration of zinc in pyrolytic carbon black expressed in mass % [c] is obtained by the following formula: 炭黑 :

[0100] [c] 炭黑 =[c] 灰分 ×100×% ash

[0101] The sulfur content in pyrolytic carbon black is determined using a LECO furnace. The LECO sulfur analyzer is designed to specifically measure the sulfur content in organic and / or inorganic materials by combustion and non-dispersive infrared detection. Before measuring the sulfur content in a sample, the boat is cleaned and the furnace is calibrated. The boat of the LECO furnace has been cleaned beforehand: this involves analyzing an empty boat under the same conditions as the sample. The calibration curve is drawn using a commercial standard sample called "BBOT" which has a purity of greater than 99.99% and a guaranteed content of carbon (C), hydrogen (H), nitrogen (N), oxygen (O) and sulfur (S). The contents are as follows: C%: 72.52; H% 6.09; N% 6.51; O% 7.43 and S% 7.44. Approximately exactly 10±3, 20±3 and 40±3 mg of BBOT are weighed into the boat. The standard sample / boat assembly is placed in the combustion furnace and adjusted to 1350°C under pure oxygen. The combination of furnace temperature and analysis flow rate causes combustion of the sample and releases sulfur and / or carbon in the form of SO2(g). After a period of 20 seconds, oxygen begins to flow through the torch to accelerate the combustion of the flame-retardant material. Sulfur and / or carbon are entrained by the oxygen flow through the infrared detection chamber in the form of SO2(g). The instrument software plots a curve that relates the introduced standard mass to the response (area) observed on the detector. This results in a calibration curve. After careful cleaning of the sampling equipment, approximately exactly 80 ± 5 mg of pyrolytic carbon black is weighed out and placed in the boat of the LECO furnace. The observed area of ​​the SO2 peak is related to the concentration via the calibration curve. The instrument software then uses the mass of the sample placed in the boat to calculate the mass % of sulfur in the sample.

[0102] For example, thermal carbon black is sold by BlackBear under the reference BBCT30 or by Scandinavian Enviro Systems under the reference P550.

[0103] In certain embodiments, the rubber composition includes 40 to 65 phr and preferably 45 to 65 phr of pyrolytic carbon black.

[0104] Carbon Black

[0105] Any carbon black, in particular the carbon black conventionally used in tires or their treads, is suitable as carbon black, in particular industrial carbon black, more particularly "furnace" black.

[0106] Among the carbon blacks, more particular mention will be made of the reinforcing carbon blacks of the 100, 200 and 300 series, or the carbon blacks of the 500, 600 or 700 series (ASTM D-1765-2017 grade), for example N115, N134, N234, N326, N330, N339, N347, N375, N550, N683 and N772 carbon blacks. Preferably, the carbon black is selected from the carbon blacks of the 300, 500, 600 and 700 series.

[0107] Carbon black can be used in its own form as commercially available, or in any other form, for example as a carrier for some of the rubber additives used. Carbon black may, for example, have been introduced into diene elastomers, in particular isoprene elastomers, in the form of a masterbatch (see, for example, patent applications WO 97 / 36724-A2 and WO 99 / 16600-A1).

[0108] In certain embodiments, the rubber composition includes from 10 phr to 30 phr, or from 20 phr to 30 phr of "conventional" carbon black, such as ASTM N326 or N550 carbon black.

[0109] Reinforced resin

[0110] The composition useful in the context of the present invention comprises 10 to 20 phr of a reinforcing resin mixture comprising a cardanol-based phenolic resin, the ratio (mass of cardanol-based phenolic resin) / (total mass of reinforcing resin) being from 0.1 to 0.7, preferably from 0.2 to 0.6, more preferably from 0.4 to 0.6.

[0111] Cardanol-based phenolic resins

[0112] A phenolic resin based on cardanol is a phenolic resin obtained by the reaction between cardanol and a methylene donor. Compounds referred to as "methylene donors" are well known to those skilled in the art. The methylene donor may be, for example, formaldehyde.

[0113] Cardanol is a phenolic lipid obtained specifically from anacardic acid, the main component of the cashew balm surrounding the cashew nut.

[0114] An example of a cardanol-based phenolic resin is Durez 12686 available from Sumitomo.

[0115] Other reinforced resins

[0116] The reinforcing resin mixture comprises at least one other reinforcing resin which is generally selected from phenolic resins, epoxy resins, benzoxazine resins, polyurethane resins, aminoplast resins and the like.

[0117] Reinforced resins commonly used in rubber compositions of tires are based on methylene acceptor / donor systems. The terms "methylene acceptor" and "methylene donor" are well known to those skilled in the art and are widely used to represent compounds that can react together (crosslink). In the curing process of the rubber matrix, the crosslinking of the resin is achieved by forming a methylene (-CH2-) bridge between the carbon in the ortho and / or para position of the phenolic ring of the resin and the methylene donor, thereby forming a three-dimensional resin network that overlaps and penetrates with the reinforcing filler / elastomer network on the one hand and overlaps and penetrates with the elastomer / sulfur network (if the crosslinking agent is sulfur) on the other hand. Examples of such methylene acceptors and donors are described in WO 02 / 10269.

[0118] Many other reinforcing resins can be used in the context of the present invention. Mention may be made in particular of those described in patent applications WO 2011 / 029938, WO 2008 / 080535, WO 2014 / 016346, WO 2013 / 017422 or WO 2014 / 016344, for example.

[0119] Preferably, the mixture of reinforcing resins comprises a phenolic resin selected from the group consisting of polyphenol-based resins, alkylphenol-based resins, aralkylphenol-based resins and mixtures thereof. Preferably, the reinforcing resin is a phenolic resin selected from the following: resins based on hydroxybenzene, resins based on bisphenol (preferably diphenolyl propane or diphenolyl methane), resins based on naphthol, resins based on cresol, resins based on tert-butylphenol, resins based on octylphenol, resins based on nonylphenol, resins based on resorcinol, resins based on phloroglucinol, resins based on xylenol (especially 3,5-xylenol), resins based on 1-naphthol, resins based on 2-naphthol, resins based on 1,5-naphthalenediol, resins based on 2,7-naphthalenediol, resins based on pyrogallol, resins based on 2-methylhydroquinone, resins based on 4-methylcatechol, resins based on 2-methylcatechol, resins based on orcinol (5-methylbenzene-1,3-diol), resins based on hydroquinone (benzene-1,4-diol), and mixtures thereof.

[0120] The reinforcing resin can also be an epoxy resin selected from aromatic epoxy compounds, alicyclic epoxy compounds, aliphatic epoxy compounds and mixtures thereof; preferably, the reinforcing resin is an epoxy resin selected from 2,2-bis[4-(glycidyloxy)phenyl]propane, poly[(o-cresyl glycidyl ether)-co-formaldehyde], poly[(phenyl glycidyl ether)-co-formaldehyde], poly[(phenyl glycidyl ether)-co-(hydroxybenzaldehyde glycidyl ether)] and mixtures thereof.

[0121] In the meaning of the present invention, reinforced resin should not be confused with "plasticized" hydrocarbon resin, which is at least partially miscible (i.e. compatible) with the polymer composition they are intended to be used for in terms of properties under the content used, thereby acting as a real diluent. Plasticized hydrocarbon resins have been particularly described in works (New York, VCH, 1997, ISBN 3-527-28617-9) entitled "Hydrocarbon Resins" such as patent application WO 2013 / 092096 or R.Mildenberg, M.Zander and G.Collin, the 5th chapter of which is dedicated to their application, particularly in the application (5.5. "Rubber Tires and Mechanical Goods") in the field of tire rubber. They can be aliphatic, alicyclic, aromatic, hydrogenated aromatic or aliphatic / aromatic types.

[0122] The compositions useful in the context of the present invention also contain reinforcing resin adjuvants (sometimes referred to as curing agents) known to the skilled person. The skilled person, based on his general knowledge or the above-mentioned literature, knows which adjuvant to combine with which reinforcing resin. The skilled person understands that the reinforcing resin adjuvant is at least bifunctional so that it can form a three-dimensional resin network with the reinforcing resin.

[0123] The reinforcing resin adjuvant may be selected from the group consisting of methylene donors, polyaldehydes, polyamines, polyimines, polyamines, polyaldimines, polyketimines, acid anhydrides and mixtures thereof.

[0124] When the reinforcing resin used is a phenolic resin, the reinforcing resin auxiliary is preferably a methylene donor selected from hexamethylenetetramine, hexa(methoxymethyl)melamine, hexa(ethoxymethyl)melamine, paraformaldehyde polymers, N-methylol derivatives of melamine, and mixtures thereof; preferably selected from hexamethylenetetramine, hexa(methoxymethyl)melamine, hexa(ethoxymethyl)melamine and mixtures thereof.

[0125] When the reinforcing resin used is an epoxy resin, the reinforcing resin auxiliary agent is preferably an amino curing agent selected from the following: polyamines (especially aliphatic polyamines, alicyclic polyamines, aliphatic amines and aromatic polyamines), dicyandiamide, polyhydrazides, imidazole compounds, sulfonium salts, onium salts, ketimines, acid anhydrides, and mixtures thereof; preferably, the reinforcing resin auxiliary agent is an amino curing agent selected from the following: ethylenediamine, diethylenetriamine, triethylenetetramine, 1,8-diaminooctane, 1,3-bis(aminomethyl)cyclohexane, m-xylylenediamine, p-xylylenediamine. Dimethylamine, m-phenylenediamine, 2,2-bis(4-aminophenyl)propane, diaminodiphenylmethane, 3,5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, methylthiotoluenediamine, dimethylthiotoluenediamine, diaminodiphenyl sulfone, 2,2'-bis(4-aminophenyl)-p-diisopropylbenzene, 3,3'-diaminobenzidine, 4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride) polyanhydride, pyromellitic dianhydride, and mixtures thereof.

[0126] The mass ratio of the curing agent / reinforcing resin mixture is usually 0.2 to 0.5.

[0127] In certain embodiments, compositions useful in the context of the present invention comprise from 10 to 20 phr of a reinforcing resin mixture comprising or consisting of a cardanol-based phenolic resin and at least one other reinforcing resin selected from phenolic resins, epoxy resins, benzoxazine resins, polyurethane resins and aminoplast resins.

[0128] In certain embodiments, the compositions useful in the context of the present invention comprise from 10 to 20 phr of a reinforcing resin mixture consisting of a cardanol-based phenolic resin and another phenolic resin, preferably another hydroxyphenyl phenolic resin.

[0129] In these embodiments, the ratio of (mass of cardanol-based phenolic resin) / (total mass of reinforcing resin) is from 0.1 to 0.7, preferably from 0.2 to 0.6, even more preferably from 0.4 to 0.6.

[0130] Cross-linking system

[0131] Compositions useful in the context of the present invention comprise a crosslinking system.

[0132] The crosslinking system may be any type of system known to those skilled in the art in the field of tire rubber compositions. It may in particular be based on sulfur and / or peroxides and / or bismaleimides.

[0133] Preferably, the crosslinking system is based on sulfur; it is then referred to as a vulcanization system. The sulfur can be provided in any form, in particular in the form of molecular sulfur and / or a sulfur donor. It is also preferred that at least one vulcanization accelerator is present, and optionally, various known vulcanization activators can also be used, such as zinc oxide, stearic acid or equivalent compounds (e.g. stearates), salts of transition metals, guanidine derivatives (in particular diphenylguanidine), or known vulcanization retarders.

[0134] Sulfur is preferably used in amounts between 0.5 and 12 phr, in particular between 1 and 10 phr, preferably between 3 and 9 phr.

[0135] Vulcanization accelerators are preferably used in amounts between 0.1 phr and 10 phr, more preferably between 0.8 phr and 2 phr.

[0136] Vulcanization activators are preferably used in amounts between 1 phr and 10 phr, more preferably between 3.3 phr and 10 phr.

[0137] As accelerator, use may be made of any compound capable of acting as an accelerator for the vulcanization of diene elastomers in the presence of sulfur, in particular accelerators of the thiazole type and derivatives thereof, or accelerators of the sulfenamide, thiuram, dithiocarbamate, dithiophosphate, thiourea and xanthate type. Mention may be made, as examples of such accelerators, of the following compounds: 2-mercaptobenzothiazole disulfide (abbreviated to MBTS), N-cyclohexyl-2-benzothiazolesulfenamide (CBS), N,N-dicyclohexyl-2-benzothiazolesulfenamide (DCBS), N-(tert-butyl)-2-benzothiazolesulfenamide (TBBS), N-(tert-butyl)-2-benzothiazolesulfenimide (TBSI), tetrabenzylthiuram disulfide (TBZTD), zinc dibenzyldithiocarbamate (ZBEC) and mixtures of these compounds.

[0138] Commonly used additives and processing aids

[0139] The compositions usable in the context of the present invention may also contain all or part of the customary additives and processing aids known to those skilled in the art and customarily used in tire rubber compositions, such as plasticizers (e.g. plasticizing oils and / or plasticizing resins with or without tackifying properties), non-reinforcing fillers, pigments, pro-oxidative metal salts, protective agents (e.g. anti-ozonant waxes), chemical antiozonants, antioxidants or anti-fatigue agents.

[0140] Preparation of composition

[0141] The compositions usable in the context of the present invention are manufactured in a suitable mixer using two consecutive preparation stages known to those skilled in the art:

[0142] a first stage of mechanical processing or kneading (called "non-preparative" stage), which can be carried out in a single thermomechanical step, during which all the necessary components, with the exception of the crosslinking system, in particular the elastomeric matrix, the filler and various other optional additives are introduced into a suitable mixer, such as a standard internal mixer (for example of the Banbury type). The filler can be introduced into the elastomer simultaneously with the thermomechanical kneading, all at once or in several portions. In the case where the filler has already been introduced in whole or in part into the elastomer in the form of a masterbatch (as described, for example, in patent applications WO 97 / 36724 or WO 99 / 16600), the masterbatch is kneaded directly and, where appropriate, the other elastomers or fillers present in the composition, not in the form of a masterbatch, and optionally various other additives, with the exception of the crosslinking system, are introduced.

[0143] The non-productive phase is carried out at elevated temperatures up to a maximum temperature of between 130° C. and 170° C. for a period of time typically between 2 minutes and 10 minutes.

[0144] - a second stage of mechanical processing (called the "preparation" stage), which is carried out in an external mixer (for example an open mill) after cooling the mixture obtained during the first non-preparation stage down to a lower temperature, typically below 110° C., for example between 40° C. and 100° C. The crosslinking system is then introduced and the combined mixture is then mixed for a few minutes, for example between 1 minute and 30 minutes.

[0145] The final composition thus obtained is subsequently calendered, for example, in the form of sheets or plaques, in particular for laboratory characterizations, or extruded into the form of semi-finished (or shaped) rubber elements that can be used, for example, as inner layers of tires.

[0146] The composition may be in the uncured state (before crosslinking or vulcanization) or in the cured state (after crosslinking or vulcanization), or may be a semi-finished product capable of being used in a tire.

[0147] Crosslinking of the composition can be carried out in a manner known to the person 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 minutes and 90 minutes.

[0148] tire

[0149] According to a first embodiment of the invention, the composition described above is particularly suitable for inclusion in at least one tire bead, and preferably in both tire beads.

[0150] The bead of a tire, also called the "bead area," is one of the three main areas of a tire (crown, sidewall, and bead).

[0151] More specifically, the bead is the portion of the tire intended to allow the tire to be attached to a mounting support, such as a wheel comprising a rim. Each bead is therefore intended in particular to come into contact with a flange of the rim, allowing it to be fixed. Thus, when the tire is inflated to its nominal pressure on a measuring rim, the bead may be radially defined on the inside by the radially innermost point of the tire and on the outside by the radially outermost point of the outer surface of the tire bead, in order to come into contact with the measuring rim of the tire according to the ETRTO (European Tire and Rim Technical Organization) 2021 standard manual.

[0152] Advantageously, the composition is one not intended to come into contact with a tire mounting support, the tire therefore comprising:

[0153] - a carcass reinforcement comprising at least one carcass layer anchored in each bead, and

[0154] - a tire seating layer intended to be in contact with the tire mounting support when the tire is mounted on the mounting support,

[0155] The or each bead comprises at least one intermediate layer arranged axially between a carcass layer and a seat layer anchored in the bead, said intermediate layer comprising a rubber composition, preferably consisting of the aforementioned rubber composition.

[0156] In a first variant of these first embodiments, the carcass layer anchored in each bead is wound around the circumferential reinforcement element of each bead so that the axially inner part of the carcass layer anchored in each bead is axially arranged on the inner side of the axially outer part of the carcass layer anchored in each bead, and the intermediate layer includes a "filling" layer, which extends radially outward from each circumferential reinforcement element and is at least partially arranged between the axially inner part and the axially outer part.

[0157] In a second variant of these first embodiments, each bead includes an axially inner circumferential reinforcement element and an axially outer circumferential reinforcement element, wherein the axially inner circumferential reinforcement element is axially arranged on the inner side of the carcass layer anchored in each bead, and the axially outer circumferential reinforcement element is axially arranged on the outer side of the carcass layer anchored in each bead, and the intermediate layer includes a layer called a filling layer, which extends axially between the seat layer and the axially outer reinforcement element.

[0158] Regardless of the embodiment described above, the seat layer is axially arranged outside the circumferential reinforcing element or each circumferential reinforcing element. Therefore, when the tire is mounted on the support, the seat layer is axially arranged between the circumferential reinforcing element or each circumferential reinforcing element and the mounting support.

[0159] Typically, the mounting support is a wheel rim.

[0160] According to a second embodiment of the invention, the composition previously described is particularly suitable for inclusion in a tread comprising:

[0161] - a radially outer layer intended to come into contact with the ground on which the tyre runs when the tyre is new, and

[0162] - a radially inner layer arranged radially inside the radially outer layer when the tyre is new, said radially inner layer comprising said rubber composition.

[0163] In a first variant of these second embodiments, the tire comprises a defined wear indicator defining a defined wear threshold of the tread, there being a predetermined wear threshold strictly less than the defined wear threshold on the tread, beyond which said radially inner layer will come into contact with the ground on which the tire runs.

[0164] In this embodiment, the radially inner layer will come into contact with the ground on which the tire is running when the wear is between the predetermined threshold and the prescribed wear threshold.

[0165] In a second variant of these second embodiments, the tire comprises a defined wear indicator limiting a defined wear threshold of the tread, the radially inner layer not being in contact with the ground on which the tire runs as long as the wear of the tread is less than or equal to the defined wear threshold.

[0166] In this embodiment, the radially inner layer does not come into contact with the ground on which the tire runs when the wear of the tire is less than that corresponding to a prescribed wear threshold. In this second variant, the radially inner layer is generally called a base layer or a supporting layer.

[0167] Typically, the tread comprises cuts separating the tread blocks from one another, at the bottom of which a wear indicator is arranged. Such wear indicators are regulated, for example, by United Nations regulations R30 and R54, American standard FMVSS139 or Chinese standard GB97743, and are intended to indicate to the user of the tire a prescribed tire wear threshold, beyond which driving is dangerous, in particular driving on wet ground. These wear indicators are therefore called prescribed wear indicators. Each prescribed wear indicator is formed by a protrusion extending radially from the bottom of the cut, in particular from the bottom of the deepest cut, with a radial height extending radially outwards that is substantially equal to 1.6 millimeters. This radial height makes it possible to define the wear potential of the tire as the radial height between the radially outermost point of the prescribed wear indicator when the tire is new and the projection of said radially outermost point on the ground when the tire is running.

[0168] As mentioned previously, tires, especially passenger vehicle tires, typically consist of:

[0169] - two beads intended to come into contact with the mounting support;

[0170] - two sidewalls extending radially outwards the beads and meeting in a crown comprising the tread and the crown reinforcement;

[0171] - At least one carcass reinforcement extending radially in each sidewall and axially in the crown, extending radially on the inside of the crown reinforcement. BRIEF DESCRIPTION OF THE DRAWINGS

[0172] The invention will be more clearly understood on reading the following description, given by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0173] - Figure 1 is a view of a tyre according to a first variant of the first embodiment of the invention, in a meridian cross-sectional plane parallel to the axis of rotation of the tyre,

[0174] - Figure 2 The second variant of the first embodiment of the present invention is Figure 1 Similar views,

[0175] - Figure 3 is a view of a first variant of the second embodiment of the invention in a meridian cross-sectional plane parallel to the axis of rotation of the tire,

[0176] - Figure 4 The second variant of the second embodiment of the present invention is Figure 3 Similar view. DETAILED DESCRIPTION

[0177] In the figures relating to the tire, reference frames X, Y, Z are shown, corresponding respectively to the usual axial direction (Y), radial direction (Z) and circumferential direction (X) of the tire.

[0178] Figure 1 A tyre according to a first variant of the first embodiment of the invention is shown and indicated with reference 10. The tyre 10 has a substantially toroidal shape about an axis of rotation substantially parallel to the axial direction Y. The tyre 10 is intended for passenger vehicles.

[0179] The tyre 10 comprises a crown 12 comprising a tread 14 intended to come into contact with the ground when the tyre is running, and a crown reinforcement 16 extending in the crown 12 along a circumferential direction X. The tyre 10 also comprises a sealing inner layer 18 which is sealed to the inflation gas and which is intended to delimit, together with the mounting support of the tyre 10, an inner cavity intended to be pressurized with the inflation gas, once the tyre 10 has been mounted on a mounting support, such as a wheel rim.

[0180] The tire 10 comprises two sidewalls 30 extending radially inwards from the crown 12. The tire 10 also comprises two beads 32 radially inside the sidewalls 30. Each bead 32 is intended to be in contact with a mounting support. Each sidewall 30 connects each bead 32 to the crown 12. Thus, the two sidewalls 30 extend the beads 32 radially outwards and meet in the crown 12. Each bead 32 is delimited radially on the inside by a radially innermost point 321 of the tire 1. Each bead 32 is delimited radially on the outside by a radially outermost point 322 of an outer surface SE of the bead 32 which, according to the ETRTO (European Tire and Rim Technical Organization) Standard Manual 2021, will be in contact with a measuring rim (not shown) of the tire 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 the point 322 defines the radially outer end ERE of the bead 32.

[0181] The tire 10 comprises a carcass reinforcement 34. The crown reinforcement 16 is arranged radially between the tread 14 and the carcass reinforcement 34. The carcass reinforcement 34 comprises at least one carcass layer 36, in this case 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 to the inside of the crown reinforcement 16.

[0182] In order to anchor the carcass layer 36, the carcass layer 36 is anchored in each bead 32 by winding around the circumferential reinforcement element 35 (in this case, the bead wire) of each bead 32, so that the axially inner portion 361 of the carcass layer 36 anchored in each bead 32 is axially arranged on the inner side of the axially outer portion 362 of the carcass layer 36 anchored in each bead 32, and so that each axial end 363 of the carcass layer 36 axially limited and anchored in each bead 32 is radially arranged on the outer side of each circumferential reinforcement element 35.

[0183] Each bead 32 comprises a first layer 42, called filling layer, extending radially outwards from each circumferential reinforcing element 35 and in contact with the carcass layer 36. The first layer 42 is arranged, at least partially, between an axially inner portion 361 and an axially outer portion 362.

[0184] Each bead 32 also comprises a second layer 44 which is arranged axially on the outside of the axially outer portion 362 and the first filling layer 42 .

[0185] Each bead 32 also comprises a third layer 46, called a seat layer of the tyre 10. The third seat layer 46 is intended to be in contact with a mounting support of the tyre 10 when the tyre is mounted on this mounting support. The third seat layer 46 is arranged axially on the outside of the circumferential reinforcing elements 35, more precisely axially between the circumferential reinforcing elements 35 and the mounting support (not shown) when the tyre is mounted on this support.

[0186] At least one of the first, second and third layers 42, 44, 46 comprises, preferably consists of, a rubber composition according to the invention. In the embodiment shown, the first filling layer 42 consists of a rubber composition according to the invention.

[0187] Figure 2 A tire core according to a second variant of the first embodiment of the invention is shown. Figure 1 Elements similar to those shown in .

[0188] Unlike the tire according to the first embodiment, the tire 10 according to the second variant is such that, in order to anchor the carcass layer 36, the tire 10 comprises an axially inner circumferential reinforcing element 38 arranged axially on the inside of the carcass layer 36 and an axially outer circumferential reinforcing element 40 arranged axially on the outside of the carcass layer 36. Here, each reinforcing element 38, 40 comprises a continuous wire reinforcing element wound on a plurality of circumferential turns, such as described in WO 2021 / 123522.

[0189] As in the first variant, at least one of the first, second and third layers 42, 44, 46 comprises, preferably consists of, a rubber composition according to the invention. In the embodiment shown, the first filling layer 42 consists of a rubber composition according to the invention.

[0190] Figure 3 A tire core according to a first variant of the second embodiment of the invention is shown. Figure 1 and Figure 2 Elements similar to those shown in .

[0191] The tread 14 comprises a radially outer layer 141 intended to come into contact with the ground on which the tyre runs when the tyre is new, and a radially inner layer 142 arranged radially inside the radially outer layer 141 when the tyre is new. The radially outer layer carries the running surface 48 of the tyre 10 intended to come into contact with the ground when the tyre is new.

[0192] The tread 14 comprises a plurality of prescribed wear indicators 50 which define a prescribed wear threshold below which the tire no longer complies with the corresponding regulations with respect to wear. In this case, the prescribed wear indicators 50 comprise protrusions 52 extending radially outwards from the bottom 54 of the cutouts 56 by a radial height ranging from 1.45 mm to 1.75 mm (here approximately equal to 1.6 mm). A prescribed wear track 58 is defined which is parallel to the rolling surface 48 of the tire 10 and passes through the radially outer surface of the prescribed wear indicators 50. Figure 3 In FIG. 5 , the prescribed wear trajectory 58 is shown by a dotted line. Figure 3 As can be seen in FIG. 5 , there is a predetermined wear threshold of the tread 14 , which is strictly less than the prescribed wear threshold indicated by the prescribed wear track 58 , beyond which the radially inner layer 142 is intended to come into contact with the ground on which the tire 10 is running. Figure 3 , the predetermined threshold is represented by the interface 60 between the radially outer layer 141 and the radially inner layer 142 .

[0193] Figure 4 A second variant of the second embodiment of the tire according to the invention is shown. Figure 3 Elements similar to those shown in .

[0194] and Figure 3 In contrast to the first variant shown, the radially inner layer 142 is intended not to come into contact with the ground on which the tire 10 runs, as long as the wear of the tread 14 is less than or equal to a prescribed wear threshold. In other words, the radially inner layer 142 is intended to come into contact with the ground on which the tire 10 runs, when the wear of the tread 14 reaches a predetermined wear threshold that exceeds the prescribed wear threshold. Figure 4 In FIG. 6 , the predetermined wear threshold is represented by the interface 60 between the radially outer layer 141 and the radially inner layer 142 .

[0195] The tire according to the invention is intended to equip motor vehicles of the passenger vehicle type, SUVs (“Sports Utility Vehicles”), or two-wheeled vehicles (especially motorcycles), or aircraft, or industrial vehicles chosen from trucks, heavy vehicles, that is, metros, buses, heavy road transport vehicles (trucks, tractors, trailers) or off-road vehicles (for example heavy agricultural vehicles or civil engineering vehicles), and other vehicles. Preferably, the tire according to the invention is particularly suitable for equipping vehicles of the passenger vehicle, truck and SUV type.

[0196] The following examples are given for illustrative purposes. In no case should they be considered to limit the present invention.

[0197] Example

[0198] Measurement method

[0199] Dynamic performance

[0200] The dynamic properties were measured on a viscoanalyzer (Metravib VA4000) according to standard ASTM D 5992-96. The vulcanized composition samples (thickness 4 mm and cross-sectional area 400 mm) were recorded at a temperature of 40°C. 2 The response of a cylindrical specimen (of a cylindrical specimen) subjected to a simple alternating sinusoidal shear stress at a frequency of 10 Hz.

[0201] To measure the tan(δ) loss factor, scans were performed with a peak-to-peak (outward cycle) strain amplitude of 0.1% to 10% and then with a peak-to-peak (return cycle) strain amplitude of 10% to 0.1%.

[0202] The lower the value of tan(δ) at 40°C, the lower the hysteresis of the composition and therefore the lower the rolling resistance. The results in terms of performance are expressed on a basis of 100, i.e. the value 100 is arbitrarily assigned to the control sample in order to subsequently compare the tan(δ) (i.e. hysteresis and therefore rolling resistance) at 40°C of the various solutions tested. The values ​​on a basis of 100 are calculated according to the following operation: (tan(δ) value of the control sample at 40°C / tan(δ) value of the sample at 40°C)*100. In this way, lower values ​​indicate reduced hysteresis performance (i.e. increased hysteresis), while higher values ​​indicate better hysteresis performance (i.e. lower hysteresis).

[0203] Tensile test measurements

[0204] The tests were carried out according to French standard NF T 46-002 of September 1988. All tensile measurements were carried out according to French standard NF T 40-101 (December 1979) under standard conditions of temperature (23±2° C.) and humidity (50%±5% relative humidity).

[0205] The nominal secant modulus (or apparent stress, in MPa) calculated by reduction to the original cross section of the specimen is measured at 10% elongation on a sample cured at 160°C for 15 minutes at the second elongation (i.e. after conditioning) and is denoted as MA 10 (elastic tensile modulus at 10% elongation). The results are expressed relative to the base of 100 for the control composition. When the value is greater than 100, the composition has a higher MA than the control composition. 10 modulus and therefore higher stiffness.

[0206] Mooney plasticity

[0207] The Mooney plasticity measurement is carried out according to the following principle and in accordance with the standard ASTM D-1646. The raw material composition is usually molded in a cylindrical chamber heated to a given temperature (usually 100° C.). After preheating for 1 minute, the L-type rotor rotates in the sample at 2 rpm, and the working torque used to maintain the motion is measured after rotating for 4 minutes. The Mooney plasticity (ML 1+4) is expressed in "Mooney units" (MU, 1MU=0.83 Newton meters). It is well known to those skilled in the art that the lower the Mooney plasticity, the easier the material is to process. All values ​​are expressed in terms of a base of 100 relative to a given control sample.

[0208] fixed

[0209] The fixation time of the mixture is determined according to standard ISO 289-2 of February 2016, but with the following deviations from the standard: the time used as fixation measurement is calculated from the moment the rotor starts to rotate, without taking into account the setting time; only t5 is measured, regardless of the rotor.

[0210] The fixed time (fixed 115°C t5) is therefore the time (in minutes) required to obtain a Mooney torque increase of 5 units relative to its minimum value, excluding minutes of preheating, from the moment the rotor starts rotating (2 rpm), regardless of the rotor used. The measurement is carried out at 115°C.

[0211] The results are expressed relative to the reference composition on a base of 100.

[0212] Preparation of composition

[0213] The composition is prepared in a suitable mixer using two consecutive preparation stages known to those skilled in the art: a first stage of thermomechanical processing or kneading at high temperature (up to a maximum temperature of between 110° C. and 200° C., preferably between 130° C. and 180° C.) (sometimes called the “non-preparation” stage), followed by a second stage of mechanical processing at a lower temperature, usually below 110° C., for example between 60° C. and 100° C. (sometimes called the “preparation” stage), during which finishing stage the crosslinking or vulcanization system is conventionally introduced.

[0214] The composition was cured at 160°C for 15 minutes.

[0215] test

[0216] The formulations of the prepared compositions are shown in Table 1 (components and contents - contents are expressed in phr unless otherwise specified).

[0217] The Mooney plasticity value of each composition was measured in the original state (ie, before vulcanization), and the tensile elastic modulus at 10% elongation (MA10) and tan (δ) loss factor were then measured in the cured state (ie, after vulcanization).

[0218] Table 1: Formulation and properties of compositions C1, C2 and INV1

[0219]

[0220]

[0221] (1) Natural rubber

[0222] (2)N326 conventional carbon black

[0223] (3) P550 pyrolytic carbon black obtained from Scandinavian Enviro Systems (ash (%): 18.5; sulfur (%): 3; zinc (%): 4.5; STSA specific surface area: 56 m 2 / g (ASTM D6556-2021); void volume at 50MPa: 44ml / 100g (ASTM D7854-21))

[0224] (5) N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine (Santoflex 6-PPD from Flexsys)

[0225] (6) Durez 28391 hydroxybenzene-based phenolic resin from Sumitomo

[0226] (7) Durez 12686 cardanol-based phenolic resin from Sumitomo

[0227] (8) N-cyclohexyl-2-benzothiazolesulfenamide obtained from Flexsys

[0228] (9) Hexamethylenetetramine obtained from Ineos Paraform

[0229] It is noteworthy that the composition of the invention (INV1) utilizes a mixture of conventional carbon black and pyrolytic carbon black, having similar stiffness and improved rolling resistance (tan (δ)) as the control composition (composition C1). In addition, the composition according to the invention has satisfactory processability (Mooney viscosity is similar to the control composition). Therefore, the composition of the invention provides a good stiffness / rolling resistance / processability compromise while incorporating a higher content of recycled and bio-based materials.

[0230] Reinforced resin content

[0231] The formulations of the prepared compositions are shown in Table 2 (components and contents - contents are expressed in phr unless otherwise specified).

[0232] The Mooney plasticity value of each composition was measured in the original state (ie, before vulcanization). The tensile elastic modulus (MA) at 10% elongation was then measured in the cured state (ie, after vulcanization). 10 ) and tan(δ) loss factors.

[0233] Table 2: Formulation and properties of compositions C3 and INV2

[0234]

[0235]

[0236] (1) Natural rubber

[0237] (2)N326 conventional carbon black

[0238] (3) P550 pyrolytic carbon black obtained from Scandinavian Enviro Systems (ash (%): 18.5; sulfur (%): 3; zinc (%): 4.5; STSA specific surface area: 56 m 2 / g (ASTM D6556-2021); void volume at 50MPa: 44ml / 100g (ASTM D7854-21))

[0239] (5) N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine (Santoflex 6-PPD from Flexsys)

[0240] (6) Durez 28391 hydroxybenzene-based phenolic resin from Sumitomo

[0241] (7) Durez 12686 cardanol-based phenolic resin from Sumitomo

[0242] (8) N-cyclohexyl-2-benzothiazolesulfenamide obtained from Flexsys

[0243] (9) Hexamethylenetetramine obtained from Ineos Paraform

[0244] It is observed that the use of a reinforcing resin blend allows the total amount of reinforcing resin used in the rubber composition to be reduced (comparison of compositions C3 and INV2). In particular, the stiffness of composition C3 (comprising 18 phr of hydroxybenzene-based phenolic resin) is lower than that of the composition usable in the context of the present invention (total reinforcing resin content of 13.8 phr).

[0245] By using a content of resin (6) (used alone, which is much higher than the total content of reinforcing resins used in the composition of the present invention), it is possible to obtain a stiffness similar to that of the composition of the present invention for a composition comprising a mixture of carbon black and pyrolytic carbon black as reinforcing filler (compare C3 and INV2).

Claims

1. A tire (10) comprising two beads (32), wherein at least one bead (32) comprises a rubber composition based on the following components: - an elastomeric matrix comprising mainly natural rubber by mass; - at least 65 phr of reinforcing filler, the reinforcing filler consisting of 40 to 70 phr of pyrolytic carbon black and 10 to 40 phr of carbon black, the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being between 0.60 and 0.75; - 10 to 20 phr of a reinforcing resin mixture comprising a phenolic resin based on cardanol, the ratio (mass of phenolic resin based on cardanol) / (total mass of reinforcing resin) being from 0.1 to 0.7; - curing agent; and - Cross-linking system.

2. The tire (10) according to claim 1, wherein: The ratio of (mass of cardanol-based phenolic resin) / (total mass of reinforcing resin) is 0.2 to 0.6, more preferably 0.4 to 0.

6.

3. The tire (10) according to claim 1 or 2, comprising: - a carcass reinforcement (34) comprising at least one carcass layer (36) anchored in each bead (32), and a tire (10) seat layer (46) intended to come into contact with the tire (10) mounting support when the tire (10) is mounted on the mounting support, The bead or each bead (32) comprises at least one intermediate layer (42, 44) arranged axially between a carcass layer (36) and a seat layer (46) anchored in the bead (32), the intermediate layer (42, 44) comprising, preferably consisting of, a rubber composition.

4. The tire (10) according to claim 3, wherein: The carcass layer (36) anchored in each bead (32) is wound around the circumferential reinforcement element (35) of each bead (32) so that the axially inner portion (361) of the carcass layer (36) anchored in each bead (32) is axially arranged on the inner side of the axially outer portion (362) of the carcass layer (36) anchored in each bead (32), and the intermediate layer (42, 44) includes a layer called a filling layer, which extends radially outward from each circumferential reinforcement element (35) and is at least partially arranged between the axially inner portion (361) and the axially outer portion (362).

5. The tire (10) according to claim 3, wherein: Each bead (32) includes an axially inner circumferential reinforcing element (38) and an axially outer circumferential reinforcing element (40), wherein the axially inner circumferential reinforcing element (38) is axially arranged on the inner side of a carcass layer (36) anchored in each bead (32), and the axially outer circumferential reinforcing element (40) is axially arranged on the outer side of the carcass layer (36) anchored in each bead (32), and the intermediate layer (42, 44) includes a layer called a filling layer, which extends axially between the seat layer (46) and the axially outer reinforcing element (40).

6. A tire (10) comprising a tread (14), the tread (14) comprising: a radially outer layer (141) intended to come into contact with the ground on which the tyre (10) runs when the tyre (10) is new, and - when the tire (10) is a new tire, the radially inner layer (142) is arranged radially inside the radially outer layer (141), The radially inner layer (142) comprises a rubber composition based on the following components: - an elastomeric matrix comprising mainly natural rubber by mass; - at least 65 phr of reinforcing filler, the reinforcing filler consisting of 40 to 70 phr of pyrolytic carbon black and 10 to 40 phr of carbon black, the ratio (mass of pyrolytic carbon black) / (total mass of reinforcing filler) being between 0.60 and 0.75; - 10 to 20 phr of a reinforcing resin mixture comprising a phenolic resin based on cardanol, the ratio (mass of phenolic resin based on cardanol) / (total mass of reinforcing resin) being from 0.1 to 0.7; - curing agent; and - Cross-linking system.

7. The tire (10) according to claim 6, wherein: The ratio of (mass of cardanol-based phenolic resin) / (total mass of reinforcing resin) is 0.2 to 0.6, more preferably 0.4 to 0.

6.

8. The tire (10) according to claim 6 or 7, comprising a prescribed wear indicator (50) defining a prescribed wear threshold of the tread (14), and a predetermined wear threshold of the tread (14) strictly less than the prescribed wear threshold, above which the radially inner layer (142) will come into contact with the ground on which the tire (10) is running.

9. The tire (10) according to claim 6 or 7 comprises a prescribed wear indicator (50) defining a prescribed wear threshold of the tread (14), wherein the radially inner layer (142) will not be in contact with the ground on which the tire (10) is running as long as the wear of the tread (14) is less than or equal to the prescribed wear threshold.

10. Tyre (10) according to any one of the preceding claims, wherein: The elastomeric matrix comprises from 50 to 100 phr, preferably from 75 to 100 phr, of natural rubber.

11. Tyre (10) according to any one of the preceding claims, wherein: The elastomeric matrix also comprises a styrene-butadiene copolymer (SBR).

12. Tyre (10) according to any one of the preceding claims, wherein: The reinforcing resin mixture includes a cardanol-based phenolic resin and at least one other reinforcing resin selected from the group consisting of a phenolic resin, an epoxy resin, a benzoxazine resin, a polyurethane resin, and an aminoplast resin.

13. Tyre (10) according to any one of the preceding claims, wherein: The reinforcing resin mixture consists of a phenolic resin based on cardanol and another phenolic resin, preferably another phenolic resin based on hydroxybenzene.

14. Tyre (10) according to any one of the preceding claims, wherein: The crosslinking system is a vulcanization system based on molecular sulphur and / or sulphur donors; preferably, the crosslinking system comprises between 0.5 and 12 phr, preferably between 3 and 9 phr, of sulphur.

15. Tyre (10) according to any one of the preceding claims, wherein: The ash content of the pyrolytic carbon black is 5 to 30 wt %, preferably 8 to 25 wt %, relative to the total weight of the pyrolytic carbon black.

16. Tyre (10) according to any one of the preceding claims, wherein: The sulfur content of the pyrolytic carbon black is greater than 2 wt %, preferably 2.5 wt % to 5 wt %, relative to the total weight of the pyrolytic carbon black.

17. Tyre (10) according to any one of the preceding claims, wherein: The composition may also contain one or more agents selected from the group consisting of plasticizers, non-reinforcing fillers, pigments, protective agents such as anti-ozone waxes, chemical antiozonants, antioxidants and anti-fatigue agents.

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