High load capacity tire with ozone- and blooming-resistant sidewalls

Abstract

The invention relates to a tire (10) for a passenger vehicle, comprising a crown (12), two beads (32), and two sidewalls (30) connecting each bead (32) to the crown (12). The tire (10) is a high load capacity tire according to the ETRTO Standards Manual 2021. At least one of the two sidewalls comprises an elastomer composition based on: at least one elastomer matrix, at least one crumb rubber, and at least one anti-ozone wax. The weight ratio of the crumb rubber content in phr to the anti-ozone wax content in phr ranges from 5.6 to 13.5.

Description

High load capacity tire with ozone and efflorescence resistant sidewalls

[0001] The present invention relates to a tire. By tire is meant a bandage intended to form a cavity by cooperating with a support element, for example a rim, this cavity being capable of being pressurized to a pressure higher than atmospheric pressure. A tire according to the invention has a structure of substantially toroidal shape of revolution around a main axis of the tire.

[0002] The advent of electric or hybrid passenger vehicles leads to an increase in the weight of vehicles, particularly due to the batteries, whose weight is relatively high and significantly proportional to the vehicles' range. For example, to increase the range of an electric vehicle, it is necessary to increase the size of the batteries and, consequently, the weight of the vehicle.

[0003] Simply put, it is estimated today that one kilometer of electric motor range increases the vehicle's weight by one kilogram. Thus, to achieve a range of 500 kilometers, it is necessary to increase the weight of a thermal engine vehicle by approximately 500 kg. To equip such vehicles, it is necessary to use tires capable of carrying a very high load.

[0004] Thus, tire manufacturers decided to create a new type of tire. This new type is now known as "HIGH LOAD CAPACITY" (which translates into French as Haute Capacité de Chargement) in the ETRTO 2021 standard manual. This new type ensures that the load that the tire of a given size is capable of carrying is greater than that which a tire of the same size but in its EXTRA-LOAD version would be capable of carrying. For the 255 / 35R18 size, the HIGH LOAD CAPACITY tire thus has a load index equal to 98 indicating that it is capable of carrying a load of 750 kg at a pressure of 290 kPa. By comparison, for the same dimension 255 / 35R18, the EXTRA-LOAD type tire has a load index equal to 94 meaning that, at a pressure of 290 kPa, this tire is capable of carrying a load of 670 kg.

[0005] A problem encountered is linked to the fact that, for a given dimension, a HIGH LOAD CAPACITY type tire is required to carry a relatively high load causing significant flexing of the sidewalls and making them susceptible to tearing, particularly when driving in a deep hole in the road or over a large bump in the road, when driving suddenly up a sidewalk, when used at a pressure significantly lower than the recommended pressure or when used under a significantly higher load. greater than the maximum load.

[0006] The elastomeric compositions constituting the sidewalls include diene rubbers, both natural and synthetic, which have carbon-carbon double bonds on their molecular chains. These double bonds are chemically more reactive than a single carbon-carbon bond and are therefore likely to deteriorate more or less rapidly after prolonged exposure to the atmosphere, due to known oxidation and ozonolysis mechanisms. These degradation mechanisms are further accelerated under the combined action of heat by thermo-oxidation, or that of light by photo-oxidation. The action of ozone in fact promotes the appearance of surface cracks, further promoting the occurrence of the tears mentioned above in the case of HIGH LOAD CAPACITY type tires.

[0007] To counteract the chemical degradation of tires caused by ozone, tire manufacturers are known to use anti-ozone agents (also called antiozonants), such as anti-ozone waxes and antioxidants. These waxes provide static protection by forming a protective coating on the surface. However, these waxes are also characterized by their ability to migrate to the surface of rubber articles and crystallize, altering the external appearance of the surfaces of elastomeric compositions by staining them or making them dull and gray, or by causing a lighter coloring of the sidewall. This phenomenon is called wax efflorescence. This phenomenon causes uneven coloring and makes the exterior surfaces of the sidewall, which initially have a shiny appearance, dull and grayish. However, uneven coloring of the tire alters the aesthetics of the tire.

[0008] It is therefore necessary to be able to at least reduce, or even eliminate, the alteration of the color and / or shine of the tire sidewall while giving it a good capacity to resist ozone attacks in order to improve its resistance to tearing.

[0009] The aim of the invention is to provide a tire capable of carrying a greater load than existing tires while improving its tear resistance and whose sidewall aesthetics are long-lasting.

[0010] To this end, the subject of the invention is a tire for a passenger vehicle comprising a crown, two beads, two sidewalls connecting each bead to the crown, the tire being of the HIGH LOAD CAPACITY type according to the ETRTO 2021 standard manual, in which at least one of the two sidewalls comprises an elastomeric composition based on at least one elastomeric matrix, at least one powder of rubber, of at least one anti-ozone wax, the weight ratio between the rate of rubber powder expressed in pce and the rate of anti-ozone wax expressed in pce being within a range from 5.6 to 13.5.

[0011] The inventors have surprisingly discovered that one way to solve this problem is to use a specific elastomeric composition based on at least one elastomeric matrix, at least one anti-ozone wax, and at least one rubber crumb having a certain weight characteristic between the rubber crumb content and the anti-ozone wax content. This elastomeric composition has excellent resistance to chemical attack, which limits the appearance of surface cracks and therefore reduces the occurrence of tears. At the same time, this elastomeric composition makes it possible to maintain the appearance of the sidewall and therefore its aesthetics.

[0012] According to the invention, the tire is for a passenger vehicle. Such a tire is for example defined in the ETRTO 2021 (European Tire and Rim Technical Organization) standard manual. Such a tire has, generally on at least one of the sidewalls, a marking in accordance with the marking in the ETRTO 2021 standard manual indicating the dimension of the tire in the form X / Y a VU p with X designating the nominal section width, Y designating the nominal aspect ratio, a designating the structure and possibly being R or ZR, V designating the nominal rim diameter, U designating the load index and designating the speed symbol.

[0013] By increasing the load index of the tire compared to the load index of a tire having the same dimension in its EXTRA-LOAD version, the invention makes it possible to increase the load capacity of the tire without modifying the habitability, compactness and comfort of the vehicle on which it is used. Indeed, the dimension of the tire of the invention being identical to that of the tire in its EXTRA-LOAD version, the tire does not take up more space than the tire in its EXTRA-LOAD version. A tire of the invention may bear a distinctive marking making it possible to distinguish it from its STANDARD LOAD version and its EXTRA-LOAD version, for example a marking of the HL (for HIGH LOAD) or XL+ (for EXTRA LOAD +) type. Such a marking is notably disclosed in the ETRTO 2021 standard manual, page 3 of the General Notes - Passenger Car tires section to designate HIGH LOAD CAPACITY type tires.Examples of dimensions are also disclosed in the ETRTO 2021 standard manual, page 44, paragraph 9.1 of the section Passenger Car tyres - Tyres with metric designation.

[0014] A HIGH LOAD CAPACITY type tire can be characterized by its load index LI such that LI > Ll'+1 and LI' being the load index of an EXTRA LOAD tire with the same dimension according to the ETRTO 2021 standard manual. The load index Ll' is the load index of an EXTRA-LOAD tire with the same dimension, i.e. the same nominal section width, the same nominal aspect ratio, the same structure (R and ZR being considered identical) and the same nominal rim diameter. The load index Ll' is given by the ETRTO 2021 standard manual, in particular in the section entitled Passenger Car Tires - Tires with Metric Designation, pages 22 to 43. Depending on the dimension, we will have LI=U'+1, LI=LI'+2, LI=LI'+3 or even LI=LI'+4. In most embodiments, Ll'+1 < Ll < LI'+4, and even LI'+2 < Ll < LI'+4.

[0015] The tire according to the invention has a substantially toric shape around an axis of revolution substantially coincident with the axis of rotation of the tire. This axis of revolution defines three directions conventionally used by those skilled in the art: an axial direction, a circumferential direction and a radial direction.

[0016] Axial direction means the direction substantially parallel to the axis of revolution of the tire, i.e. the axis of rotation of the tire.

[0017] Circumferential direction means the direction which is substantially perpendicular to both the axial direction and a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire).

[0018] By radial direction is meant the direction along a radius of the tire, that is to say any direction intersecting the axis of rotation of the tire and substantially perpendicular to this axis.

[0019] By median plane of the tire (noted M), we mean the plane perpendicular to the axis of rotation of the tire which is located at the axial midpoint of the two beads and passes through the axial center of the crown reinforcement.

[0020] The equatorial circumferential surface of the tire means the association of the planes passing, in each meridian section plane, through the equator (denoted E) of the tire and perpendicular to the median plane and to the radial direction. The equator of the tire is, in a meridian section plane (plane perpendicular to the circumferential direction and parallel to the radial and axial directions) the axis parallel to the axis of rotation of the tire and located equidistant between the radially outermost point of the tread intended to be in contact with the ground and the radially innermost point of the tire intended to be in contact with a support, for example a rim, the distance between these two points being equal to H.

[0021] Meridian plane means a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0022] By radially inner, respectively radially outer, we mean closer to the axis of rotation of the tire, respectively further from the axis of rotation of the tire. By axially inner, respectively axially outer, we mean closer to the median plane of the tire, respectively further from the median plane of the tire.

[0023] A bead means the portion of the tire intended to allow the tire to be attached to a mounting support, for example a wheel comprising a rim. Thus, each bead is in particular intended to be in contact with a hook on the rim allowing it to be attached. Thus, the radially outer end of the outer surface of the tire bead is defined as the point on the radially outermost outer surface of the tire in contact with a tire measurement rim according to the ETRTO standard manual, 2021 when the tire is inflated to its nominal pressure on this measurement rim.

[0024] Any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​from more than a to less than b (i.e., excluding the limits 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 limits a and b).

[0025] 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 manufacture of the composition; the composition can thus be in a totally or partially crosslinked state or in a non-crosslinked state.

[0026] By the expression "part by weight per hundred parts by weight of elastomer" (or pce), it is meant, within the meaning of the present invention, the part, by mass per hundred parts by mass of elastomer in the sense of the preparation of the composition before curing. That is to say, in the case of the presence of a rubber crumb, the term "pce" means part by weight per hundred parts of "new" elastomers, therefore excluding from the base 100 the elastomers contained in the rubber crumb.

[0027] In this document, unless expressly stated otherwise, all percentages (%) indicated are percentages (%) by mass.

[0028] When we refer to a “majority” compound, it is understood, within the meaning of the present invention, that this compound is the majority among the compounds of the same type in the composition, that is to say that it is the one which represents the greatest quantity by mass among the compounds of the same type. Thus, for example, a majority elastomer is the elastomer representing the greatest mass relative to the total mass of the elastomers in the composition. In the same way, a so-called majority filler is the one representing the greatest mass among the fillers in the composition. As for example, in a system comprising a single elastomer, this is the majority within the meaning of the present invention; and in a system comprising two elastomers, the majority elastomer represents more than half of the mass of the elastomers. On the contrary, a “minority” compound is a compound which does not represent the largest mass fraction among the compounds of the same type. Preferably, by majority, is meant present at more than 50%, preferably more than 51%, 60%, 70%, 80%, 90%, and more preferably the “majority” compound represents 100%.

[0029] The compounds mentioned in the description may be of fossil or bio-sourced origin. In the latter case, they may be, partially or totally, derived from biomass or obtained from renewable raw materials derived from biomass. Obviously, the compounds mentioned may also come from the recycling of materials already in use, that is to say, they may be, partially or totally, derived from a recycling process, or obtained from raw materials themselves derived from a recycling process. This includes in particular polymers, plasticizers, fillers, etc.

[0030] In optional and advantageous embodiments, the weight ratio between the level of rubber powder expressed in pce and the level of anti-ozone wax expressed in pce is within a range from 5.6 to 13.0, preferably from 5.6 to 12.5, more preferably from 6.5 to 12.5.

[0031] The elastomeric composition comprises at least one elastomer, for example a diene elastomer. In certain optional embodiments, the elastomeric composition comprises several elastomers, in particular several diene elastomers. This elastomer or this mixture of elastomers, in particular diene elastomers, is referred to in the remainder of the description as the elastomeric matrix. In the case where the elastomeric composition comprises several elastomers, these elastomers are of course different two by two.

[0032] The term "elastomer" means a polymer, i.e., a homopolymer or copolymer, with elastic properties obtained after crosslinking. The term rubber is a common synonym for elastomer.

[0033] By "diene elastomer" or indistinctly "diene rubber", whether natural or synthetic, is meant an elastomer consisting at least in part (i.e., a homopolymer or a copolymer) of diene monomer units (monomers carrying two carbon-carbon double bonds, conjugated or not). Diene elastomers are by definition non-thermoplastic.

[0034] Preferably, the elastomeric matrix comprises at least two diene elastomers different from each other.

[0035] These diene elastomers can be classified into two categories: "essentially unsaturated" or "essentially saturated". "Essentially unsaturated" generally means a diene elastomer derived at least in part from conjugated diene monomers, having a content of units or patterns of diene origin (conjugated dienes) which is greater than 15% (mol %); thus, diene elastomers such as butyl rubbers or copolymers of dienes and alpha-olefins such as EPDM do not fall within the previous definition and can be described in particular as "essentially saturated" diene elastomers (low or very low content of patterns of diene origin, always less than 15%).

[0036] The term diene elastomer capable of being used in elastomeric compositions particularly means: - any homopolymer of a diene monomer, conjugated or not, having from 4 to 18 carbon atoms; - any copolymer of a diene, conjugated or not, having from 4 to 18 carbon atoms and at least one other monomer; the other being able to be ethylene, an olefin or a diene, conjugated or not.

[0037] Suitable conjugated dienes are conjugated dienes having 4 to 12 carbon atoms, in particular 1,3-dienes, such as 1,3-butadiene and isoprene.

[0038] Suitable non-conjugated dienes are non-conjugated dienes with 6 to 12 carbon atoms, such as 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene.

[0039] Suitable olefins are vinylaromatic compounds with 8 to 20 carbon atoms and aliphatic α-monoolefins with 3 to 12 carbon atoms.

[0040] Suitable vinyl aromatic compounds are, for example, styrene, ortho-, meta-, para-methylstyrene, the commercial mixture "vinyl-toluene", para-tert-butylstyrene.

[0041] Suitable aliphatic α-monoolefins are, in particular, acyclic aliphatic α-monoolefins having from 3 to 18 carbon atoms.

[0042] More specifically, the diene elastomer is: - any homopolymer of a conjugated diene monomer, in particular any homopolymer obtained by polymerization of a conjugated diene monomer having from 4 to 12 carbon atoms; - any copolymer obtained by copolymerization of one or more conjugated dienes with each other or with one or more vinylaromatic compounds having from 8 to 20 carbon atoms; - 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 a non-conjugated diene monomer of the aforementioned type.

[0043] According to an advantageous embodiment making it possible to improve tear resistance and the aesthetics of the sidewall are long-lasting, the elastomeric matrix comprises at least one isoprene elastomer and at least one butadiene elastomer.

[0044] By "isoprenic elastomer" is meant, in a known manner, a homopolymer or a copolymer of isoprene, in other words an isoprene elastomer can be chosen from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR), the various isoprene copolymers and the mixtures of these elastomers. Among the isoprene copolymers, mention will be made in particular of isobutene-isoprene copolymers (butyl rubber - HR), isoprene-styrene (SIR), isoprene-butadiene (BIR) or isoprene-butadiene-styrene (SBIR). Preferably, the isoprene elastomer can be chosen from the group consisting of natural rubber, synthetic cis-1,4 polyisoprenes, and the mixtures of these elastomers.Even more preferably, the isoprene elastomer is chosen from the group consisting of natural rubber, synthetic polyisoprenes having a rate (mol%) of cis-1,4 bonds greater than 90% (even more preferably greater than 98%), and mixtures of these elastomers. In a preferred embodiment, the rate of isoprene elastomer is within a range from 20 to 80 phr, preferably from 30 to 70 phr, more preferably between 30 and 70 phr and even more preferably from 35 to 65 phr.

[0045] By "butadiene elastomer" is meant, in a known manner, a homopolymer or a copolymer of butadiene, in particular a diene elastomer which can be chosen from the group consisting of polybutadienes (BR), the different copolymers of butadiene and the mixtures of these elastomers. Among the copolymers of butadiene, mention will be made in particular of copolymers of butadiene-styrene (SBR), or of ethylene-butadiene (EBR). Preferably, the butadiene elastomer can be a cis-1,4 polybutadiene; in particular a polybutadiene having a rate (mol%) of cis-1,4 bonds greater than 90%, more preferably still greater than 96%. In a preferred embodiment, the level of butadiene elastomer is within a range from 20 to 80 phr, preferably from 30 to 70 phr, more preferably between 30 and 70 phr and even more preferably from 35 to 65 phr.

[0046] Preferably in this advantageous mode, the elastomeric matrix comprises at least one isoprene elastomer chosen from the group consisting of natural rubber (NR), synthetic cis-1,4 polyisoprenes (IR) in particular those having a rate (mol%) of cis-1,4 bonds greater than 90% (more preferably still greater than 98%), isoprene-styrene copolymers (SIR), isoprene-butadiene copolymers (BIR), isoprene-butadiene-styrene copolymers (SBIR), and mixtures of these elastomers and at least one butadiene elastomer chosen from the group consisting of polybutadienes (BR) in particular a cis-1,4 polybutadiene having a rate (mol%) of cis-1,4 bonds greater than 90% (more preferably still greater than 96%), butadiene-styrene copolymers (SBR), ethylene-butadiene copolymers (EBR), and blends of these elastomers.

[0047] More preferably still, the elastomeric matrix comprises at least one isoprene elastomer chosen from the group consisting of natural rubber (NR), synthetic cis-1,4 polyisoprenes (IR), in particular those having a rate (mol%) of cis-1,4 bonds greater than 90% (more preferably still greater than 98%), and mixtures of these elastomers and at least one butadiene elastomer which is a polybutadiene (BR), in particular a cis-1,4 polybutadiene having a rate (mol%) of cis-1,4 bonds greater than 90% (more preferably still greater than 96%).

[0048] Even more preferably, the elastomeric matrix comprises at least one isoprene elastomer which is natural rubber (NR) and at least one butadiene elastomer which is a polybutadiene (BR), in particular a cis-1,4 polybutadiene having a rate (mol%) of cis-1,4 bonds greater than 90% (even more preferably greater than 96%).

[0049] In preferred embodiments in which the elastomeric matrix comprises at least one isoprene elastomer and at least one butadiene elastomer, the level of isoprene elastomer is in a range from 20 to 80 phr and the level of butadiene elastomer is in a range from 20 to 80 phr. Preferably, in this embodiment, the level of isoprene elastomer is in a range from 30 to 70 phr and the level of butadiene elastomer is in a range from 30 to 70 phr. More preferably, the level of isoprene elastomer is in a range between 30 and 70 phr and the level of butadiene elastomer is in a range between 30 and 70 phr. Even more preferably, the rate of isoprene elastomer is within a range of 35 to 65 pce and the rate of butadiene elastomer is within a range of 35 to 65 pce.These rates make it possible to obtain a sidewall with good tear resistance and a long-lasting aesthetic.

[0050] In a particularly advantageous embodiment, the matrix elastomeric comprises at least one isoprene elastomer and at least one butadiene elastomer; the isoprene elastomer being chosen from the group consisting of natural rubber (NR), synthetic cis-1,4 polyisoprenes (IR), in particular those having a rate (mol%) of cis-1,4 bonds greater than 90% (more preferably still greater than 98%) and the rate of this isoprene elastomer being within a range from 20 to 80 phr, preferably from 30 to 70 phr, preferably between 30 and 70 phr, more preferably still ranging from 35 to 65 phr;the butadiene elastomer being a polybutadiene (BR), in particular a cis-1,4 polybutadiene having a rate (mol%) of cis-1,4 bonds greater than 90% (more preferably still greater than 96%) and the rate of this butadiene elastomer being within a range from 20 to 80 phr, preferably from 30 to 70 phr, preferably between 30 and 70 phr, more preferably still from 35 to 65 phr.;

[0051] Rubber powder

[0052] The elastomeric composition of the sidewall useful in the context of the present invention also comprises a rubber crumb (also called “crum rubber” in English).

[0053] The powders usable in the context of the present invention are in the form of granules, possibly formed into a rubber plate. Most often these powders are produced by grinding or micronizing vulcanized elastomeric compositions already used for a first application, for example in tires, shoe soles, seals, etc. They are a product of recycling these materials.

[0054] All rubber powders from the recycling of elastomeric compositions, particularly those from used tires, are suitable.

[0055] As is known, rubber crumb can be obtained by reducing used tires or other rubber into granules from which reinforcing materials such as steel or textile fibers have been removed, as well as any other contaminants such as dust, glass or stones.

[0056] For example, rubber crumbs were prepared by cryogenic grinding of used tires according to the process described in US 7,445,170, comprising the successive and independent steps of granulation, separation of the metal and textile reinforcements, cooling and micronization in order to obtain a rough distribution of micron-sized particles of vulcanized mixture (also called microparticles). This micronization can be carried out using a conical impact crusher as described in US 7,861,958. The cryogenized input enters the crusher (for example CUM150 crushers from the company Netzsch or CW250 from Alpine can be used), then is transferred by gravity to a rotor rotating at high speed. The cryogenized input is thus projected onto the walls of the rotor chamber multiple times leading to its micronization. The particles can then pass through a series of two vibrating sieves of the same size in order to separate the last elements not made up of vulcanized mixture. A rough distribution of micron particles of vulcanized mixture is obtained. 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. The size of the microparticles can be determined by techniques known to those skilled in the art such as microscopy for example.

[0057] In some embodiments, the rubber crumbs are simple ground / micronised rubber, without any further treatment. It is also known that rubber crumbs can undergo treatment in order to modify them. This treatment may consist of a chemical modification of functionalization or devulcanization. It may also be a thermomechanical, thermochemical, biological treatment, etc.

[0058] According to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting and which can be combined with the other embodiments, the rubber powder is a powder which has not undergone any modification by a treatment chosen from the group consisting of thermal, mechanical, biological and chemical treatments and their combinations.

[0059] According to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting and which can be combined with the other embodiments, the rubber crumb may have a microparticle size distribution such that it comprises less than 1% by mass of micro particles not retained through a 600 μm sieve and less than 10% by mass of micro particles not retained through a 105 μm sieve relative to the total mass of micro particles in the rubber crumb, more preferably a microparticle size distribution such that it comprises less than 1% by mass of micro particles not retained through a 600 μm sieve and less than 10% by mass of micro particles not retained through a 149 μm sieve;more preferably still a microparticle size distribution such that it comprises less than 1% by mass of micro particles not retained through a 600 pm sieve and less than 10% by mass of micro particles not retained through a 177 pm sieve; a microparticle size distribution such that it comprises less than 1% by mass of; microparticles not retained through a 400 pm sieve, and less than 10% by mass of microparticles not retained through a 177 pm sieve relative to the total mass of microparticles in the rubber crumb. The distribution of microparticles in rubber crumb being determined according to ASTM D5644-01: 2013.

[0060] According to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting and which can be combined with the other embodiments, the rubber crumb can have a micro-particle size distribution such that it comprises less than 1% by mass of microparticles not retained through a 250 μm sieve and less than 10% by mass of microparticles not retained through a 177 μm sieve relative to the total mass of micro-particles of the rubber crumb.

[0061] To obtain such a rubber crumb having such a distribution, an additional sieving step according to a size criterion was carried out. The sieving can be carried out by different technologies (vibration, centrifugation, suction) known to those skilled in the art. Preferably, this sieving step is carried out using a series of sieves stacked in order of size (sieves with calibrated mesh sizes such as the commercial products of the Gericke company, for example). Thus, the largest particles are retained on the sieve while the smallest pass to the lower stage on the next sieve. Those skilled in the art will understand that the distributions considered subsequently can be composed of all the particles passing a given sieve or of all the particles retained between 2 stages.

[0062] Rubber crumbs are usually made up of ingredients from an elastomeric composition used in tires. In other words, rubber crumbs are usually made up of a composition based on at least one elastomer and at least one filler, particularly a reinforcing filler. They may also include all the ingredients usually used in elastomeric compositions, particularly intended for the manufacture of tires, such as plasticizers, antioxidants, vulcanization additives, etc. These ingredients have been described above and, for the sake of brevity, are not repeated here.

[0063] Thus, the rubber crumbs comprise at least one diene elastomer as described above and at least one carbon black as described above. Preferably, this diene elastomer preferably represents at least 30% by mass, more preferably at least 35% by mass, even more preferably at least 40% by mass relative to the weight of the rubber crumb, percentage determined according to standard ASTM E1131-03. Preferably, the carbon black is present in the rubber crumb at a rate ranging from 20 to 40% by mass, more preferably from 25 to 35% by mass relative to the weight of the rubber crumb; percentage determined according to the method described above.

[0064] The measurement of the mass fraction of carbon black is carried out by thermogravimetric analysis (TGA) according to the NF T-46-07 standard, on a device from the company Mettler Toledo model "TGA / DSC1". Approximately 20g of sample is introduced into the thermal analyzer, then subjected to a thermal program from 25 to 600°C under an inert atmosphere (pyrolyzable phase) then from 400 to 750°C under an oxidizing atmosphere (oxidizable phase). The mass of the sample is measured continuously throughout the thermal program. The organic matter content corresponds to the mass loss measured during the pyrolyzable phase relative to the initial sample mass. The black content corresponds to the mass loss measured during the oxidizable phase relative to the initial sample mass.

[0065] A person skilled in the art knows how to adapt the rubber crumb content to the requirements of the invention. The rubber crumbs that can be used in the context of the present invention are available from suppliers such as, for example, Lehigh Technology.

[0066] Preferably, according to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting, the rubber powder content is within a range from 2 to 30 phr, preferably between 5 and 20 phr, more preferably from 5.5 to 19.5 phr, even more preferably from 6 to 19 phr, and very preferably between 6 and 18 phr.

[0067] Anti-ozone wax

[0068] Anti-ozone waxes are known and can be, for example, paraffin waxes, microcrystalline waxes or mixtures of paraffin and microcrystalline waxes. They consist of a mixture of linear alkanes and non-linear alkanes (isoalkanes, cycloalkanes, branched alkanes) derived from petroleum refining or the catalytic hydrogenation of carbon monoxide (Fisher Tropsch process) mainly comprising chains of at least 20 carbon atoms.

[0069] All known anti-ozone waxes can be used, including natural waxes such as candelilla wax or carnauba wax. These waxes can also be used for cutting.

[0070] Commercially available anti-ozone waxes include Sasol's "Varazon 4959", "Varazon 6500" and "Varazon 6810", Nippon Seiro's "Ozoace 0355", H&R's "Negozone 9343" and Yanggu Huatai's "H3841".

[0071] According to a preferred embodiment of the elastomeric composition useful in the scope of the present invention and can be combined with the embodiments of the invention, the rate of the wax is within a range from 1 to 3 pce, preferably from 1.2 pce to 2.8 pce, more preferably from 1.4 to 2.6 pce and even more preferably from 1.6 to 2.4 pce.

[0072] Reinforcing charge

[0073] In optional and advantageous embodiments, the elastomeric composition comprises at least one reinforcing filler (i.e., one or more reinforcing fillers).

[0074] Any type of so-called reinforcing filler, known for its ability to reinforce an elastomeric composition usable in particular for the manufacture of tires, may be used, for example an organic filler such as carbon black, an inorganic filler such as silica or alumina or a mixture of these types of fillers. For the purposes of the present invention, the rubber crumb described below is not considered to be a reinforcing filler within the meaning of the invention. Consequently, the level of rubber crumb is not included in the level of reinforcing filler and is a level separate from it.

[0075] Preferably, the rate of the reinforcing filler in the elastomeric composition is within a range from 5 to 70 phr, preferably from 5 to 60 phr, more preferably from 5 to 55 phr, even more preferably between 5 and 55 phr, very preferably between 10 and 50 phr and most preferably from 20 to 45 phr. These rates make it possible to obtain a sidewall having good tear resistance properties and whose aesthetics are long-lasting.

[0076] Suitable carbon blacks are all carbon blacks, including those conventionally used in tires. Among the latter, we will particularly mention the reinforcing carbon blacks of the 100, 200, 300 series, or the 500, 600 or 700 series blacks (ASTM D-1765-2017 grades), such as for example blacks N115, N134, N234, N326, N330, N339, N347, N375, N550, N683, N772). These carbon blacks can be used in the isolated state, as commercially available, or in any other form, for example as a carrier for some of the rubber additives used. Carbon blacks could, for example, already be incorporated into the diene elastomer, in particular isoprene, in the form of a masterbatch (see, for example, applications WO97 / 36724-A2 or W099 / 16600-A1).

[0077] By "reinforcing inorganic filler" is meant here any inorganic or mineral filler, whatever its color and origin (natural or synthetic), also called "white" filler, "clear" filler or even "non-" filler. black" as opposed to carbon black, capable of reinforcing on its own, without any other means than an intermediate coupling agent, an elastomeric 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.

[0078] Suitable reinforcing inorganic fillers are, in particular, mineral fillers of the siliceous type, preferably silica (SiO2) or of the aluminous type, in particular alumina (AI2O3). The silica used may be any reinforcing silica known to those skilled in the art, in particular any precipitated or pyrogenic silica having a BET specific surface area and a CTAB specific surface area both of less than 450 m2 / g, preferably in a range from 30 to 400 m2 / g, in particular from 60 to 300 m2 / g. The BET specific surface area of ​​the silica is determined by gas adsorption using the Brunauer-Emmett-Teller method described in "The Journal of the American Chemical Society" (Vol.60, page 309, February 1938), and more precisely according to a method adapted from the standard NF ISO 5794-1, annex E of June 2010 [multipoint volumetric method (5 points) - gas: nitrogen - vacuum degassing: one hour at 160°C - relative pressure range p / po: 0.05 to 0.17], The CTAB specific surface area values ​​of silica were determined according to the standard NF ISO 5794-1, annex G of June 2010. The process is based on the adsorption of CTAB (N-hexadecyl-N,N,N-trimethylammonium bromide) on the "external" surface of the reinforcing filler.

[0079] Any type of precipitated silica may be used, in particular highly dispersible precipitated silicas (called "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 WO03 / 016215-A1 and WO03 / 016387-A1. Among the commercial HDS silicas, it is possible to use in particular the silicas "Ultrasil ® 5000GR", "Ultrasil ® 7000GR" from the company Evonik, the silicas "Zeosil ® 1085GR", "Zeosil® 1115 MP", "Zeosil® 1165MP", "Zeosil® Premium 200MP", "Zeosil® HRS 1200 MP" from the company Solvay.

[0080] The physical state in which the reinforcing inorganic filler is presented is indifferent, whether in the form of powder, microbeads, granules, or even beads or any other suitable densified form. Of course, the term reinforcing inorganic filler also means mixtures of different reinforcing inorganic fillers, in particular silicas as described above.

[0081] To couple the reinforcing inorganic filler, in particular silica, to the diene elastomer, it is possible to use, in a well-known manner, an at least bifunctional coupling agent (or bonding agent) intended to ensure a sufficient connection, of a nature chemical and / or physical, between the inorganic filler (surface of its particles) and the diene elastomer. In particular, at least bifunctional organosilanes or polyorganosiloxanes are used, comprising a first functional group capable of interacting with the inorganic filler and a second functional group capable of interacting with the diene elastomer. For example, such a bifunctional compound may comprise a first functional group comprising a silicon atom, said first functional group being capable of interacting with the hydroxyl groups of an inorganic filler and a second functional group comprising a sulfur atom, said second functional group being capable of interacting with the diene elastomer.Preferably, the organosilanes are chosen from the group consisting of polysulfurized organosilanes (symmetrical or asymmetrical) such as bis(3-triethoxysilylpropyl) tetrasulfide, abbreviated to TESPT, marketed under the name “Si69” by the company Evonik or bis-(triethoxysilylpropyl) disulfide, abbreviated to TESPD, marketed under the name “Si75” by the company Evonik, polyorganosiloxanes, mercaptosilanes, blocked mercaptosilanes, such as S-(3-(triethoxysilyl)propyl) octanethioate marketed by the company Momentive under the name “NXT Silane”. More preferably, the organosilane is a polysulfurized organosilane.

[0082] According to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting and which can be combined with the other embodiments, the reinforcing filler mainly comprises carbon black, that is to say comprises at least 51% by weight of carbon black relative to the total weight of the reinforcing filler. Optionally in this advantageous embodiment, the reinforcing filler may also comprise silica or another reinforcing inorganic filler. Preferably in this advantageous embodiment, the carbon black represents more than 60% by weight, preferably more than 80% by weight, more preferably more than 90% by weight, preferably represents 100% by weight of the total weight of the reinforcing filler.

[0083] Preferably, the level of reinforcing filler in the elastomeric composition is within a range from 5 to 70 phr, the carbon black representing more than 51% by weight, more than 60% by weight, preferably more than 80% by weight, more preferably more than 90% by weight, preferably representing 100% by weight of the total weight of the reinforcing filler.

[0084] More preferably, the level of reinforcing filler in the elastomeric composition is within a range from 5 to 60 pce, the carbon black representing more than 51% by weight, more than 60% by weight, preferably more than 80%. by weight, more preferably more than 90% by weight, preferably represents 100% by weight of the total weight of the reinforcing filler.

[0085] Preferably again, the level of reinforcing filler in the elastomeric composition is within a range from 5 phr to 55 phr, the carbon black representing more than 51% by weight, more than 60% by weight, preferably more than 80% by weight, more preferably more than 90% by weight, preferably representing 100% by weight of the total weight of the reinforcing filler.

[0086] Preferably again, the level of reinforcing filler in the elastomeric composition is within a range of between 5 and 55 pce, the carbon black representing more than 51% by weight, more than 60% by weight, preferably more than 80% by weight, more preferably more than 90% by weight, preferably representing 100% by weight of the total weight of the reinforcing filler.

[0087] Even more preferably, the level of reinforcing filler in the elastomeric composition is within a range of between 10 and 50 phr, the carbon black representing more than 51% by weight, more than 60% by weight, preferably more than 80% by weight, more preferably more than 90% by weight, preferably representing 100% by weight of the total weight of the reinforcing filler.

[0088] Even more preferably, the level of reinforcing filler in the elastomeric composition is within a range from 20 to 45 phr, the carbon black representing more than 51% by weight, more than 60% by weight, preferably more than 80% by weight, more preferably more than 90% by weight, preferably representing 100% by weight of the total weight of the reinforcing filler.

[0089] According to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting, the elastomeric composition comprising a reinforcing filler, the sum of the rate of reinforcing filler and the rate of rubber crumb is within a range from 30 to 65 phr, preferably from 30 to 60 phr and more preferably between 35 and 50 phr.

[0090] According to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting, the weight ratio between the rate of rubber powder expressed in pce and the rate of reinforcing filler expressed in pce is within a range from 0.20 to 2.50, preferably from 0.20 to 1.50.

[0091] Crosslinking system

[0092] In embodiments, the elastomeric composition comprises at least one crosslinking system.

[0093] The crosslinking system may be any type of system known to those skilled in the art in the field of elastomeric compositions for tires. It may in particular be based on sulfur, and / or peroxide and / or bismaleimides.

[0094] Preferably, the crosslinking system is sulfur-based, in which case it is referred to as a vulcanization system. The sulfur can be provided in any form, in particular in the form of molecular sulfur, or a sulfur-donating agent. At least one vulcanization accelerator is also preferably present, and, optionally, also preferably, various known vulcanization activators can be used, such as zinc oxide, stearic acid or an equivalent compound such as stearic acid salts and transition metal salts, guanidine derivatives (in particular diphenylguanidine), or even known vulcanization retarders.Any compound capable of acting as an accelerator for the vulcanization of diene elastomers in the presence of sulfur may be used as an accelerator, in particular accelerators of the thiazole type and their derivatives, accelerators of the sulfenamide, thiuram, dithiocarbamate, dithiophosphate, thiourea and xanthate types.

[0095] Sulphur may be used at a preferential rate in the range of 0.5 to 12 pce, in particular 0.7 and 7 pce. The vulcanisation accelerator may be used at a preferential rate in the range of 0.5 to 10 pce, more preferably 0.5 to 5.0 pce.

[0096] Other additives

[0097] The elastomeric composition may optionally also comprise all or part of the usual additives and processing agents, known to those skilled in the art and usually used in elastomeric compositions intended in particular for the manufacture of tires, in particular sidewalls, such as for example plasticizers (such as plasticizing oils and / or plasticizing resins), non-reinforcing fillers, pigments, anti-oxidant protection agents, anti-fatigue agents, reinforcing resins (as described for example in application WO02 / 10269).

[0098] Plasticizing agent

[0099] In embodiments for softening the sidewall and thus making it less susceptible to tearing, the elastomeric composition optionally comprises at least one plasticizing agent (i.e., one or more plasticizing agents). In addition to improving tear resistance, the plasticizing agent makes it possible to reduce the hysteresis of the tire sidewall and therefore the rolling resistance of the tire.

[0100] In preferred and optional embodiments, the plasticizing agent is selected from the group consisting of plasticizing oils, high Tg plasticizing resins, and mixtures of these plasticizing agents.

[0101] According to an advantageous embodiment giving the sidewall good tear resistance properties and which can be combined with the other embodiments, the elastomeric composition comprising a plasticizing agent, the level of plasticizing agent is within a range from 2 to 28 pce, more preferably from 5 to 15 pce.

[0102] Any extender oil, whether aromatic or non-aromatic, known for its plasticizing properties with respect to the elastomer matrix, can be used. At room temperature (23°C), these oils, more or less viscous, are liquids (that is to say, as a reminder, substances having the capacity to eventually take the shape of their container), in contrast in particular to high Tg hydrocarbon resins which are by nature solid at room temperature and atmospheric pressure.

[0103] Plasticizing oil generally has a glass transition temperature, Tg, below -20°C, preferably below -40°C. The Tg of plasticizing oil is measured according to ASTM D3418 (2008).

[0104] In certain embodiments, particularly suitable as plasticizing agent for the elastomeric composition are plasticizing oils chosen from the group consisting of naphthenic oils (low or high viscosity, in particular hydrogenated or not), paraffinic oils, DAE (Distillate Aromatic Extracts) oils, polyolefin 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 plasticizing oils.

[0105] According to an advantageous embodiment giving the sidewall very good tear resistance properties and which can be combined with the other embodiments of the invention, the plasticizing agent is an oil chosen from the group consisting of MES oils, TDAE oils, RAE oils, TRAE oils, SRAE oils, mineral oils, vegetable oils and mixtures of these plasticizing oils.

[0106] By definition, a high Tg hydrocarbon resin is by definition a solid at room temperature and pressure (23°C, 1 atm), while a plasticizing oil is liquid at room temperature and a low Tg hydrocarbon resin is viscous at room temperature.

[0107] Hydrocarbon resins, also called hydrocarbon plasticizing resins, are polymers well known to those skilled in the art, essentially based on carbon and hydrogen but may contain other types of atoms, for example oxygen, which can be used in particular as plasticizing agents or tackifying agents in polymer matrices. They are by nature at least partially miscible (i.e., compatible) at the rates used with the polymer compositions for which they are intended, so as to act as true diluting agents. They have been described for example in the work entitled "Hydrocarbon Resins" by R. Mildenberg, M. Zander and G. Collin (New York, VCH, 1997, ISBN 3-527-28617-9) of which Chapter 5 is devoted to their applications, in particular in pneumatic rubber (5.5. "Rubber Tires and Mechanical Goods"). As is known, these hydrocarbon resins can also be described as thermoplastic resins in the sense that they soften upon heating and can thus be molded.

[0108] The softening point of hydrocarbon resins is measured according to ISO 4625 (“Ring and Bail” method). The Tg of the hydrocarbon resin is measured according to ASTM D3418 (2008). 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 pm 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”).

[0109] Hydrocarbon resins can be aliphatic, or aromatic or of the aliphatic / aromatic type, i.e. based on aliphatic and / or aromatic monomers. They can be natural or synthetic, based on petroleum or not (if this is the case, also known as petroleum resins). Suitable aromatic monomers include, for example, styrene, alpha-methylstyrene, indene, ortho-, meta-, para-methylstyrene, vinyl toluene, para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, vinyl mesitylene, divinylbenzene, vinyl naphthalene, any vinyl aromatic monomer from a C9 fraction (or more generally from a C8 to C10 fraction). Preferably, the vinylaromatic monomer is styrene or a vinylaromatic monomer from a C9 cut (or more generally from a C8 to C10 cut). Preferably, the vinylaromatic monomer is the minority monomer, expressed as a molar fraction, in the copolymer considered.

[0110] In certain embodiments, particularly suitable plasticizing agents for the elastomeric composition are hydrocarbon plasticizing resins chosen from the group consisting of cyclopentadiene (abbreviated CPD) or dicyclopentadiene (abbreviated DCPD) homopolymer or copolymer resins, of terpene homopolymers or copolymers, 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. The term "terpene" herein includes in a known manner the alpha-pinene, beta-pinene and limonene monomers; preferably a limonene monomer is used, a compound occurring in a known manner in the form of three possible isomers: L-limonene (levorotatory enantiomer), D-limonene (dextrorotatory enantiomer), or dipentene, racemic of the dextrorotatory and levorotatory enantiomers. Among the above hydrocarbon plasticizing resins, mention will be made in particular of homo- or copolymer resins of alpha-pinene, beta-pinene, dipentene or polylimonene.

[0111] Very preferably, the hydrocarbon resin is mainly composed of units derived from C5 monomers. By C5 monomers, it is conventionally understood for those skilled in the art to mean monomers derived from C4 to C6 petroleum fractions. Suitable examples are 1,3-pentadiene, cis and trans, pentenes, cyclopentadiene, cyclopentene, piperylene, isoprene, etc. This so-called C5 resin, mainly composed of units derived from C5 monomers, may comprise, in addition to these units, and in a minority, aliphatic or aromatic units or even of the aliphatic / aromatic type, i.e. based on aliphatic and / or aromatic monomers, other than C5.Preferably, the hydrocarbon resin that can be used is mainly composed of units derived from C5 monomers, has an aromatic proton content of less than 20%, preferably less than 15%, more preferably an aromatic proton content in a range from 7 to 15%, preferably from 9 to 13%. Also preferably, this hydrocarbon resin has an ethylenic proton content of less than 15%, preferably less than 7%, more preferably less than 5%. Preferably, the C5 hydrocarbon resin has a glass transition temperature (Tg) in a range from 30°C to 80°C, preferably from 40 to 60°C. The C5 hydrocarbon resin has an average molecular weight Mn in a range from 500 g / mol to 3000 g / mol and preferably from 700 to 2000 g / mol.Preferably, the hydrocarbon resin has a polydispersity index (PDI) in the range from 1 to 4, preferably from 1.5 to 3.5, more preferably from 1.7 to 3. There are many commercially available hydrocarbon resins. These resins may have characteristics, in particular chemical composition, Tg, Mn, aromatic proton level, ethylenic or PDI, which differ depending on the supplier. The macrostructure (Mw, Mn, PDI and Mz) of the hydrocarbon resin is determined by size exclusion chromatography. steric (SEC) based on ISO 16014 (Determination of average molecular mass and molecular mass distribution of polymers using size exclusion chromatography), ASTM D5296 (Molecular Weight Averages and molecular weight distribution of polystyrene by High performance size exclusion chromatography), and DIN 55672 (size exclusion chromatography) The aromatic proton content (%HA) and the ethylenic proton content (%HE) are measured by 1 H NMR. This determination is carried out relative to all the detected signals. Thus, the results obtained are expressed in % peak area. C5 resins are commercially available, for example sold by Eastman under the name "Piccotac 1105" or "Impera R1507", by Exxon under the name "Escorez 1102", by Kolon under the name "Hikorez A1100" or by Cray Valley Total under the name "Wingtack98".C5-C9 resins are commercially available, for example sold by Exxon under the name “OPPERA373”, by Eastman under the name “Piccotac 8090”, by Cray Valley Total under the name “Wingtack STS”.

[0112] When the plasticizing agent is a mixture of a hydrocarbon resin and an oil, the plasticizing agent content is the sum of the hydrocarbon resin content in pce and the oil content in pce, for the calculation of the ratio described above.

[0113] According to an advantageous embodiment giving the sidewall good tear resistance properties and whose aesthetics are long-lasting, the elastomeric composition comprising a plasticizing agent, the weight ratio between the level of the reinforcing filler expressed in pce and the level of plasticizing agent expressed in pce is within a range between 1.0 and 5.0, preferably ranging from 1.5 to 4.5, more preferably ranging from 2.0 to 4.0 and even more preferably ranging from 2.0 to 3.5.

[0114] Process for preparing the elastomeric composition useful in the context of the present invention

[0115] The elastomeric composition useful in the context of the present 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 (so-called "non-productive" phase), which can be carried out in a single thermomechanical step during which all the necessary constituents are introduced into a suitable mixer such as a standard internal mixer (for example of the "Banbury" type), in particular the elastomeric matrix, the reinforcing filler, the rubber crumb, the anti-ozone wax and any other various additives, with the exception of the crosslinking system. The non-productive phase can be carried out at high temperature, up to a maximum temperature in the range from 110°C to 200°C, preferably from 130°C to 185°C, for a duration generally of between 2 and 10 minutes; - a second mechanical working phase (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 120°C, for example ranging from 40°C to 100°C. The crosslinking system is then incorporated, preferably the vulcanization system (in particular the vulcanization agent, the vulcanization accelerator and optionally the vulcanization retarder if present), and everything is then mixed for a few minutes, for example from 5 to 15 min.

[0116] The final elastomeric 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) rubber usable for a sidewall of a tire.

[0117] The elastomeric composition can be either in the raw state (before crosslinking or vulcanization), or in the cured state (after crosslinking or vulcanization), can be a semi-finished product which can be used in a tire.

[0118] The crosslinking, in particular the vulcanization, of the elastomeric composition can be carried out in a manner known to those skilled in the art, for example at a temperature in a range from 130°C to 200°C, under pressure.

[0119] The tires are intended for passenger vehicles as defined in the ETRTO standard manual, 2021. Such a tire has a section in a meridian cutting plane characterized by a section height H and a nominal section width or flange thickness S within the meaning of the ETRTO standard manual, 2021 such that, optionally, the H / S ratio, expressed as a percentage, is at most equal to 90, preferably at most equal to 50 and more preferably at most equal to 40 and is at least equal to 20, preferably at least equal to 25, and the nominal section width S is at least equal to 155 mm, preferably at least equal to 205 mm and more preferably at least equal to 225 mm and at most equal to 385 mm, preferably at most equal to 335. In addition, the hook diameter D, defining the diameter of the tire mounting rim, is at least equal to 12 inches, preferably at least equal to 16 inches and at most equal to 24 inches.

[0120] Optionally, the tire comprises a carcass reinforcement comprising at least one carcass layer anchored in the or each bead and extending radially in the or each flank and axially in the crown radially internal to the crown reinforcement.

[0121] Optionally, the or each carcass layer is delimited axially by two axial ends and comprises carcass reinforcement elements extending axially from one axial end to the other of said carcass layer in a main direction forming, optionally and preferably, with the circumferential direction of the tire, an angle, in absolute value, greater than or equal to 60°, preferably ranging from 80° to 90°.

[0122] In some variants, the carcass reinforcement comprises a single carcass layer anchored in the or each bead and extending radially in each sidewall and axially in the crown radially inward to the crown reinforcement. By single carcass layer anchored in the or each bead, it is understood that the carcass reinforcement is, with the exception of the carcass layer, devoid of any layer reinforced by reinforcing elements and anchored in the or each bead. The reinforcing elements of such reinforced layers excluded from the carcass reinforcement of the tire include the metal reinforcing elements and the textile reinforcing elements. Very preferably, the carcass reinforcement is constituted by the single carcass layer. Even more preferably, the tire is devoid of a sidewall reinforcing layer as defined below.

[0123] In a first configuration of the carcass reinforcement comprising a single carcass layer, the carcass layer anchored in each bead forms 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.

[0124] In a second configuration of the carcass reinforcement comprising a single carcass layer, each bead comprises an axially inner circumferential reinforcing element arranged axially inside the carcass layer and an axially outer circumferential reinforcing element arranged axially outside the carcass layer, for example as described in WO2021 / 123522.

[0125] In some variants, the carcass reinforcement comprises first and second carcass layers anchored in the or each bead and extending radially in each sidewall and axially in the crown radially inward of the crown reinforcement.

[0126] In a first configuration of the carcass reinforcement comprising first and second carcass layers, the first carcass layer forms a wrap around a circumferential reinforcing element of each bead such that an axially inner portion of the first carcass layer is arranged axially inside an axially outer portion of the first carcass layer and such that each axial end of the first carcass layer is arranged radially outside each circumferential reinforcing element, and each axial end of the second carcass layer is arranged radially inside each axial end of the first layer.

[0127] In a first variant of the first configuration, each axial end of the second carcass layer is arranged axially between the axially inner and outer portions of the first carcass layer. In this variant, the second carcass layer is arranged radially outside the first carcass layer in the crown.

[0128] In a second variant of the first configuration, each axial end of the second carcass layer is arranged axially inside each axially inner portion of the first carcass layer. In this variant, the second carcass layer is arranged radially inside the first carcass layer in the crown and axially inside the first carcass layer in each sidewall.

[0129] Such arrangements of the first and second carcass layers in the first and second variants make it possible to obtain an effective mechanical coupling between the first and second carcass layers making it possible to reduce the shear between the first and second carcass layers. Thus, energy dissipation and the rise in the temperature of the tire are reduced, all the more so since the shear is particularly high at high loads.

[0130] Furthermore, thanks to the particular arrangement of the first and second carcass layers, a tire is surprisingly obtained with optimal energy dissipation and operating temperature in the sidewall, especially at high load and under a pressure lower than or equal to the pressure recommended for a tire of the same size in its STANDARD LOAD or EXTRA-LOAD version. This is all the more surprising since the particular arrangement of the first and second carcass layers is located in one area of ​​the tire, here in the bead or close to the bead, and that this makes it possible to reduce the energy dissipation in another area of ​​the tire, far from the bead, here the sidewall. It has been discovered that the particular arrangement of the carcass reinforcement, i.e. the fact that each axial end of the second carcass layer is arranged axially between the axially inner and outer portions of the first carcass layer, or axially inside the axially inner portion of the first carcass layer, makes it possible to reduce the difference in tensions between the first carcass layer and the second carcass layer. However, the smaller the difference in tensions between the first and second carcass layers, the less shear is generated between these first and second carcass layers and the less energy is dissipated.

[0131] In a third variant of the first configuration, each axial end of the second carcass layer is arranged axially outside each axially outer portion of the first carcass layer. In this variant, the second carcass layer is arranged radially outside the first carcass layer in the crown and axially outside the first carcass layer in each sidewall.

[0132] This third variant is particularly advantageous for tires with relatively high sidewalls. Indeed, for HIGH LOAD CAPACITY type tires with a relatively high sidewall height, the tension of the end of the first carcass layer becomes high, it is preferable to consider a carcass reinforcement in which, unlike the arrangement described in the first and second configurations, each axial end of the second carcass layer is arranged axially outside each axially outer portion of the first carcass layer. With such an arrangement of the carcass reinforcement, the tension of the end of the first carcass layer will be reduced to a lower level.

[0133] In a second configuration of the carcass reinforcement comprising first and second carcass layers, each bead comprising at least first and second circumferential reinforcing elements, a portion of each first and second carcass layer is arranged axially between two of the at least first and second circumferential reinforcing elements. Such configurations are described in particular in WO2021 / 123522.

[0134] Regardless of the number of carcass layers of each first configuration, in certain variants, each axial end of the carcass layer or of the first carcass layer is arranged radially inside the equator of the tire and even more preferably arranged at a radial distance less than or equal to 30 mm from a radially inner end of each circumferential reinforcing element of each bead.

[0135] By arranging each axial end of the wound carcass layer inside the tire's equator, the mass of the carcass reinforcement. In addition, the vast majority of rims currently used for passenger vehicle tires have J-type hooks whose height is, in all cases, less than 30 mm. The very preferential arrangement of each axial end in an area corresponding radially substantially to the rim hook makes it possible to mechanically protect each axial end. Indeed, if each axial end were arranged radially too far above each circumferential reinforcement element of each bead, that is to say at a radial distance strictly greater than 30 mm from the radially inner end of each circumferential reinforcement element, each axial end would then find itself in a flexible zone of the tire subjected to excessive stresses, stresses which are very significant in the case of a HIGH LOAD CAPACITY type tire.

[0136] Regardless of the number of carcass layers of each first configuration, in other variants, each axial end of the carcass layer or of the first carcass layer is arranged radially outside the equator of the tire. Advantageously, in these other embodiments, each axial end of the carcass layer or of the first carcass layer is very preferably arranged axially inside an axial end of the or at least one of the crown layers of the crown reinforcement.

[0137] In still other variants, the carcass reinforcement comprises a single carcass layer anchored in each bead and extending radially in each sidewall and axially in the crown radially inside the crown reinforcement, the tire comprising a sidewall reinforcement layer extending at least radially in each sidewall and having: - a radially inner end arranged radially inside the equator of the tire, - a radially outer end arranged radially outside the equator of the tire.

[0138] In these still other variants, the invention makes it possible in particular to avoid the use of a second carcass layer extending axially in the crown radially inside the crown reinforcement. Thus, the sidewall reinforcement layers are discontinuous under the crown of the tire.

[0139] A sidewall reinforcement layer is not anchored in a bead of the tire. Thus, the radially inner end of the sidewall reinforcement layer is arranged radially outside the bead.

[0140] In advantageous embodiments, the crown reinforcement comprises a working reinforcement comprising at least one working layer and a hooping comprising at least one hooping layer, the hooping reinforcement being arranged radially outside the working reinforcement.

[0141] Optionally, the or each hoop layer is delimited axially by two axial ends. The or each hoop layer comprises one or more hoop reinforcement elements wound circumferentially helically so as to extend axially from one axial end to the other of the hoop layer in a main direction. Optionally and preferably, the main direction forms, with the circumferential direction of the tire, an angle, in absolute value, less than or equal to 10°, preferably less than or equal to 7° and more preferably less than or equal to 5°.

[0142] Optionally, the or each working layer is delimited axially by two axial ends. The or each working layer comprises working reinforcement elements extending axially from one axial end to the other substantially parallel to each other in a main direction which, optionally and preferably, forms, with the circumferential direction of the tire, an angle in absolute value, strictly greater than 10°, preferably ranging from 15° to 50° and more preferably ranging from 25° to 45°.

[0143] Preferably, the or each hoop, working and carcass reinforcing element is a wire reinforcing element.

[0144] By reinforcing element is meant an element allowing the mechanical reinforcement of the polymer matrix in which this reinforcing element is intended to be embedded.

[0145] Preferably, each reinforcing element is wire-like, that is to say that each reinforcing element has a length at least 10 times greater than the largest dimension of its section regardless of the shape of the latter: circular, elliptical, oblong, polygonal, in particular rectangular or square or oval. In the case of a rectangular section, the wire-like reinforcing element has the shape of a strip.

[0146] In optional but advantageous embodiments, the tire has a sidewall height H defined by H=SW x AR / 100 with SW the nominal section width and AR the nominal aspect ratio of the tire and a load index Ll verifying 0.72 < H / LI < 0.98 preferably 0.82 < H / LI < 0.98 and even more preferably 0.82 < H / LI < 0.92 with SW, AR and Ll being defined according to the ETRTO 2021 standard manual. The nominal section width SW and the nominal aspect ratio AR are those of the dimension marking inscribed on the sidewall of the tire and, for example, comply with the ETRTO 2021 standard manual. Such H / LI ratios are characteristic of tires having a sidewall likely to flex very strongly given the height of the sidewall relative to the maximum load likely to be worn.

[0147] The invention will be better understood upon reading the following description, given solely as a non-limiting example and with reference to the drawings in which: - figure 1 is a view, in a meridian section plane parallel to the axis of rotation of the tire, of a tire according to a first embodiment of the invention, - figures 2 to 6 are views similar to that of figure 1 of tires respectively according to second, third, fourth, fifth and sixth embodiments of the invention.

[0148] In the figures relating to the tire, a reference X, Y, Z is shown corresponding to the usual axial (Y), radial (Z) and circumferential (X) directions of a tire.

[0149] Figure 1 shows a tire, in accordance with 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 and has dimensions 255 / 35 R18. The tire 10 is of the HIGH LOAD CAPACITY type according to the ETRTO 2021 standard manual. In the various figures, the tire 10 is shown in new condition, that is to say not having yet been driven. The tire 10 has a sidewall height H defined by H=SW x AR / 100 with SW the nominal section width, here 255, and AR the nominal aspect ratio of the tire, here 35. The load index Ll is here equal to 98. Thus, the load index Ll verifies 0.72 < H / LI < 0.98 preferably 0.82 < H / LI < 0.98 and even more preferably 0.82 < H / LI < 0.92 and here H / LI=0.91. SW, AR and Ll are defined according to the ETRTO 2021 standard manual.

[0150] The tire 10 comprises a crown 12 comprising a tread 14 intended to come into contact with a ground during rolling and a crown reinforcement 16 extending in the crown 12 in the circumferential direction X. The tire 10 also comprises an internal sealing layer 18 to an inflation gas being intended to delimit an internal cavity with a mounting support of 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. The internal sealing layer 18 carries an internal surface 19 of the tire 10. The tire 10 also has an external surface 31.

[0151] The crown reinforcement 16 comprises a working reinforcement 20 and a hoop reinforcement 22, each of these reinforcements 20, 22 comprising at least one layer of top. The working reinforcement 20 comprises at least one working layer and here comprises two working layers comprising a radially inner working layer 24 arranged radially inside a radially outer working layer 26.

[0152] The hoop reinforcement 22 comprises at least one hoop layer and here comprises a hoop layer 28.

[0153] The crown reinforcement 16 is arranged radially inside the tread 14. Here, the hoop reinforcement 22, here the hoop layer 28, is arranged radially outside the working reinforcement 20 and is therefore radially interposed between the working reinforcement 20 and the tread 14.

[0154] The tire 10 comprises two sidewalls 30 extending the crown 12 radially inwards. The tire 10 further comprises two beads 32 radially inwards to the sidewalls 30. Each sidewall 30 connects each bead 32 to the crown 12. Each sidewall 30 carries a portion of the external surface 31 of said sidewall 30. Each sidewall 30 comprises an elastomeric composition as described above and exemplified below.

[0155] 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, 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 inside the crown reinforcement 16.

[0156] For the purpose of anchoring the carcass layer 36, the tire 10 comprises an axially inner circumferential reinforcing element 38 arranged axially inside the carcass layer 36 and an axially outer 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 WO2021 / 123522.

[0157] The crown reinforcement 16 comprises two axial ends 161, 162 merged here with the ends of the axially widest layer of the crown reinforcement 16.

[0158] Each working layer 24, 26, hooping layer 28 and carcass layer 36 comprises a polymeric matrix, here elastomeric, in which one or more reinforcing elements of the corresponding layer are embedded, here wire reinforcement elements. The matrix is ​​said to be polymeric because it is based on a polymeric composition, this polymeric composition being able to comprise one or more polymers, for example chosen from thermoplastic polymers, thermosetting polymers, elastomers, thermoplastic elastomers, but also fillers and other components usually used in the field of tire compositions, in particular compositions for embedding reinforcing elements.

[0159] The hoop reinforcement 22, here the hoop layer 28, is delimited axially by two axial ends, here the axial ends 161, 162. The hoop reinforcement 22 comprises one or more hoop wire reinforcement elements wound circumferentially helically so as to extend axially from one axial end to the other of the hoop layer 28 in a main direction DO. The main direction DO forms, with the circumferential direction X of the tire 10, an angle AF, in absolute value, less than or equal to 10°, preferably less than or equal to 7° and more preferably less than or equal to 5°. Here, AF=-5°.

[0160] The radially inner working layer 24 is delimited axially by two axial ends. The radially inner working layer 24 comprises working filamentary reinforcing elements extending axially from one axial end to the other substantially parallel to each other in a main direction D1. Similarly, the radially outer working layer 26 is delimited axially by two axial ends. The radially outer working layer 26 comprises working filamentary reinforcing elements extending axially from the axial end to the other substantially parallel to each other in a main direction D2. Each main direction D1, D2 forms, with the circumferential direction X of the tire 10, angles AT1 and AT2 respectively of opposite orientations.Each main direction D1, D2 forms, with the circumferential direction X of the tire 10, an angle respectively AT1, AT2, in absolute value, strictly greater than 10°, preferably ranging from 15° to 50° and more preferably ranging from 25° to 45°. Here, AT1=-33° and AT2=+33°.

[0161] The carcass layer 36 is delimited axially by two axial ends 361, 362. The carcass layer 36 comprises carcass wire reinforcement elements extending axially from one axial end 361, 362 to the other of the carcass layer 36 in a main direction D3 forming with the circumferential direction X of the tire 10, an angle AC, in absolute value, greater than or equal to 60°, preferably ranging from 80° to 90° and here AC=+90°.

[0162] Each hoop, working and carcass wire reinforcement element is, for example, identical to those described in application WO2021 / 123522.

[0163] The tread 14 comprises a running surface 38 through which the tread 14 contacts the ground. The tread 14 comprises several circumferential cutouts, here several circumferential grooves, comprising first, second, third and fourth circumferential cutouts respectively designated by the references 52, 54, 56, 58.

[0164] The tread 14 also comprises several central ribs and here first, second and third central ribs respectively designated by the references 62, 64, 66. Each central rib 62, 64, 66 is arranged axially between two of the adjacent circumferential cutouts 52 to 58 and is delimited axially by two adjacent circumferential cutouts 52 to 58. The tread 14 also comprises first and second lateral ribs 68, 70.

[0165] Although not visible in Figure 1, each central rib 62, 64, 66 and each lateral rib 68, 70 includes transverse cutouts formed in each central rib 62, 64, 66 and each lateral rib 68, 70.

[0166] We will now describe tires according to second, third, fourth, fifth and sixth embodiments of the invention respectively with reference to Figures 2 to 6 in which the elements similar to those shown in the preceding figures are designated by identical references.

[0167] Unlike the tire according to the first embodiment, the tire 10 according to the second embodiment of FIG. 2 is such that the carcass layer 36 anchored in each bead 32 forms a winding around a circumferential reinforcing element 35 of each bead 32, here a bead wire, so that an axially inner portion 3611, 3621 of the carcass layer 36 anchored in each bead 32 is arranged axially inside an axially outer portion 3612, 3622 of the carcass layer 36 anchored in each bead 32 and so that each axial end 361, 362 axially delimiting the carcass layer 36 anchored in each bead 32 is arranged radially outside each circumferential reinforcing element. 35. Each axial end 361, 362 of the carcass layer 36 anchored in each bead 32 is arranged radially inside the equator E of the tire.More precisely, each axial end 361, 362 of the carcass layer 36 anchored in each bead 32 is arranged at a radial distance RNC less than or equal to 30 mm from a radially inner end 351 of each circumferential reinforcing element 33 of each bead 32. Here RNC=23 mm.

[0168] Unlike the tire according to the second embodiment, the tire 10 according to the third embodiment of FIG. 3 is such that each axial end 361, 362 of the carcass layer 36 is arranged radially outside the equator E. Here, each axial end 361, 362 of the carcass layer 36 is arranged very preferably axially inside each axial end 161, 162 of the hooping layer 28.

[0169] Unlike the tires according to the previous embodiments, the carcass reinforcement 34 of the tire 10 according to the fourth embodiment of FIG. 4 comprises first and second carcass layers 36, 37 anchored in each bead 32 and extending radially in each sidewall 30 and axially in the crown 12 radially inside the crown reinforcement 16. The second carcass layer 37 is arranged axially outside the first carcass layer 36 in each sidewall and radially outside the first carcass layer 37 in the crown 12.

[0170] The second carcass layer 37 is delimited axially by two axial ends 371, 372. The second carcass layer 37 comprises wire carcass reinforcement elements extending axially from one axial end 371, 372 to the other of the second carcass layer 37 in a main direction D4 forming with the circumferential direction X of the tire 10, an angle AC, in absolute value, greater than or equal to 60°, preferably ranging from 80° to 90° and here AC=+90°.

[0171] Unlike the tire according to the fourth embodiment, the tire 10 according to the fifth embodiment of Figure 5 is such that the first carcass layer 36 is arranged as in the second embodiment illustrated in Figure 2. Furthermore, each axial end 371, 372 of the second carcass layer 37 is arranged axially between the axially inner 3611, 3621 and outer 3612, 3622 portions of the first carcass layer 36. The second carcass layer 37 is arranged radially outside the first carcass layer 36 in the crown 12.

[0172] Other variants of arrangement of the second carcass layer 37 are possible as previously described in the generic description of the present application.

[0173] Unlike the first and second embodiments, the tire 10 according to the sixth embodiment of FIG. 6 comprises two sidewall reinforcement layers 42, 43 extending at least radially in each sidewall 30 and having a radially inner end 421, 431 arranged radially inside the equator E and a radially outer end 422, 432 arranged radially outside the equator E. The tire 10 therefore comprises two sidewall reinforcement layers 42, 43 which are discontinuous under the crown 12.

[0174] Comparative tests

[0175] In order to confirm the properties of the elastomeric composition useful in the In the context of the present invention, ten elastomeric compositions (two reference elastomeric compositions T1, T2 and elastomeric compositions C1 to C8) were used. The formulations of the elastomeric compositions are presented in Tables 1 and 2 with the quantity of the various ingredients expressed in pce.

[0176] Each elastomeric composition was produced as follows: the reinforcing filler, the elastomeric matrix, the anti-ozone wax, the rubber crumb when present, the plasticizing agent and the various other ingredients, with the exception of the vulcanization system, were successively introduced into an internal mixer having an initial tank temperature of 60°C; the “Bandury” type internal mixer being filled to approximately 70% by volume. The thermomechanical working (non-productive phase) was then carried out in a single step lasting from 3 minutes to 4 minutes, until a maximum “drop” temperature of 165°C was reached.The mixture thus obtained was recovered and cooled, then the vulcanizing agent (sulfur) and the vulcanization accelerator (N-cyclohexyl-2-benzothiazolesulfenamide) of the crosslinking system were incorporated on an external mixer (homofinisseur) at a temperature of 30°C, the whole being mixed (productive phase) for a time of more than 5 minutes and less than 12 minutes.

[0177] The elastomeric compositions thus obtained were then calendered in the form of sheets for the measurement of their ozone resistance properties and for the measurement of efflorescence according to the protocols below.

[0178] Ozone resistance measurement

[0179] The ozone resistance of materials is measured using the following method: after curing at 150°C for 40 min in a bell press, then cooling at room temperature (23°C) for one day and then baking at 77°C in air for 28 days, 10 test pieces for each of the elastomeric compositions to be tested are placed on a trapezoid at different elongations ranging from 10% to 100% in 10% elongation steps. The so-called "B15" test pieces come from an MFTR plate (called Monsanto) whose two beads located at the ends are used to hold the test piece. The so-called "B15" test pieces have the following dimensions: 78.5 mm * 15 mm * 1.5 mm. After 192 hours of exposure to a temperature of 38°C and an ozone level of 50 ppm (parts per hundred million), each facies is noted according to the number and depth of cracks.This subjective rating ranges from 0 to 5 (0: no cracks; 1 to 4: presence of increasingly significant and deep cracks; 5: rupture of the specimen). The average of the ratings of all deformations is used as the classification criterion. The lower the average, the better the ozone resistance performance.

[0180] Each difference between the averages of the ratings of all the deformations of certain elastomeric compositions and the reference T1 is presented in Table 1.

[0181] Similarly, Table 2 presents each difference between the averages of the ratings of all the deformations of the other elastomeric compositions and the reference T2.

[0182] A negative value in Tables 1 and 2 indicates an improvement in ozone resistance performance compared to the reference T 1 for Table 1 and to the reference T2 for Table 2.

[0183] Efflorescence performance measurement

[0184] After cutting the vulcanized elastomeric composition plates, the 2.5 mm thick test pieces are oven-dried at 70°C for 12 hours in air. They are then oven-dried at 40°C in air for 4 weeks. After removal from the oven and exposure to room temperature (23°C) for 15 minutes, a mechanical stimulus is applied to reveal the wax efflorescence. In this case, the mechanical stimulus consists of scraping the test piece with a metal blade. The extent of the efflorescence phenomenon (white coloration of the surface) is then evaluated using a subjective scale of values ​​that is representative of the final appearance of the samples. The values ​​of this subjective scale that were respectively obtained for the tested samples can vary from 0 to 3, and correspond to the “efflorescence rating”. These values, ranging from 0 to 3, correspond to the following aspects for the samples: 0 - No efflorescence. The scraped surface remains black. 1 - Slight efflorescence. 2 - Moderate efflorescence. 3 - Total efflorescence. The scraped surface is white.

[0185] The lower the value, the better the aspect of efflorescence performance, i.e., low efflorescence. Each difference between the efflorescence values ​​of some elastomeric compositions and the reference T1 is presented in Table 1. Similarly, Table 2 expresses each difference between the efflorescence values ​​of other elastomeric compositions and the reference T2. A negative value in Tables 1 and 2 indicates an improvement in efflorescence performance compared to each reference T1, T2 respectively.

[0186] In tables 1 and 2 above, the weight ratio (A+B+C) / D is the ratio between the rubber powder content expressed in pce and the anti-ozone wax content expressed in pce

[0187] [Table 1]

[0188] Table 1

[0189] (1) - Natural rubber; (2) - Cis-1,4 polybutadiene synthesized with a neodymium catalyst having a cis-1,4 bonding rate of at least 98 mol%; (3) - Carbon black of grade ASTM N550 according to ASTM D1765-14 having an STSA measured according to ASTM D6556-10 equal to 39 m2 / g, a COAN index measured according to ASTM D3493-16 equal to 85 ml / 100g; (4) - Rubber crumb obtained by recycling (micronization of used tires), rubber crumb marketed by Lehigh Technology whose percentage of crumb microparticles measured according to standard ASTM D5644-01:2013 retained by a 400 pm sieve is less than 1% by weight and whose percentage of crumb particles retained by a 250 pm sieve is less than 12% by weight relative to the total weight of the rubber crumb particles, unmodified rubber crumb;(5) - Rubber crumb obtained by recycling (micronization of used tires), rubber crumb marketed by Lehigh Technology whose percentage of micro crumb particles measured according to standard ASTM D5644-01:2013 retained by a 250 pm sieve is less than 1% by weight and whose percentage of crumb particles retained by a 177 pm sieve is less than 10% by weight relative to; total weight of rubber crumb particles, unmodified rubber crumb; (6) - Rubber crumb obtained by recycling (micronization of used tires), rubber crumb marketed by Lehigh Technology whose percentage of crumb microparticles measured according to ASTM D5644-01:2013 retained by a 600 pm sieve is less than 1% by weight and whose percentage of crumb particles retained by a 400 pm sieve is less than 12% by weight relative to the total weight of rubber crumb particles, unmodified rubber crumb; (7) - Anti-ozone wax marketed by Sasol under the commercial reference “Vazazon 4959”; (8) - TDAE oil marketed by H&R under the commercial reference “VivaTec 500”; (9) - C5 plasticizing hydrocarbon resin marketed by Exxon under the commercial reference “Escorez 1102”;(10) - Mixture of 2 antioxidants: ((N-(1,3-dimethylbutyl)-N-phenyl-para-phenylenediamine marketed by Flexsys under the reference “Santoflex 6-PPD” and 2,2,4-trimethyl-1,2-dihydroquinolone marketed by Lanxess; (11) - Stearic acid marketed by Uniquema under the reference “Pristerene 4931”; (12) - Zinc oxide: commercial quality, marketed by Umicore; (13) - N-dicyclohexyl-2-benzothiazolesulfenamide marketed by Flexsys under the reference “Santocure CBS”.;

[0190] The results in Table 1 show that only the elastomeric compositions according to the invention simultaneously exhibit better efflorescence performance and better ozone resistance performance compared to the reference elastomeric composition T1.

[0191] [Table 2]

[0192] Table 2

[0193] The ingredients in Table 2 are the same as those listed in Table 1.

[0194] The results in Table 2 also show that the examples according to the invention simultaneously exhibit better efflorescence performance and better ozone resistance performance than the reference elastomeric composition T2 and than the elastomeric compositions not in accordance with the invention.

[0195] In conclusion, the elastomeric compositions according to the invention make it possible to obtain a sidewall with excellent performance in terms of efflorescence and ozone resistance. On a HIGH LOAD CAPACITY type tire with sidewalls likely to flex significantly, this performance improves its tear resistance and gives it a long-lasting sidewall aesthetic.

[0196] The invention is not limited to the embodiments described above.

Claims

CLAIMS 1. A tire (10) for a passenger vehicle comprising a crown (12), two beads (32), two sidewalls (30) connecting each bead (32) to the crown (12), the tire (10) being of the HIGH LOAD CAPACITY type according to the ETRTO 2021 standard manual, characterized in that at least one of the two sidewalls comprises an elastomeric composition based on at least one elastomeric matrix, at least one rubber crumb, at least one anti-ozone wax, in that the weight ratio between the rubber crumb content expressed in pce and the anti-ozone wax content expressed in pce is within a range from 5.6 to 13.

5.

2. Tire (10) according to the preceding claim, in which the weight ratio between the rate of rubber crumb expressed in pce and the rate of anti-ozone wax expressed in pce is within a range from 5.6 to 13.0, preferably from 5.6 to 12.5, more preferably from 6.5 to 12.

5.

3. Tire (10) according to any one of the preceding claims, in which the wax content is within a range from 1 to 3 pce, preferably from 1.2 to 2.8 pce, more preferably from 1.4 to 2.6 pce and even more preferably from 1.6 to 2.4 pce.

4. Tire (10) according to any one of the preceding claims, in which the rubber crumb content is within a range from 2 to 30 phr, preferably between 5 and 20 phr, more preferably from 5.5 to 19.5 phr, even more preferably from 6 to 19 phr, and very preferably between 6 and 18 phr.

5. A tire (10) according to any one of the preceding claims, wherein the elastomeric composition comprises at least one plasticizing agent selected from the group consisting of plasticizing oils, high Tg plasticizing resins, and mixtures of these plasticizing agents.

6. Tire (10) according to any one of the preceding claims, in which, the elastomeric composition comprising a reinforcing filler and a plasticizing agent, the weight ratio between the level of reinforcing filler expressed in pce and the level of plasticizing agent expressed in pce is within a range between 1.0 and 5.0, preferably ranging from 1.5 to 4.5, more preferably ranging from 2.0 to 4.0 and even more preferably ranging from 2.0 to 3.

5.

7. Tire (10) according to any one of the preceding claims, in which, the elastomeric composition comprising a reinforcing filler, the sum of the rate of the reinforcing filler and the rate of rubber crumb is included in a range from 30 to 65 pce, preferably from 30 to 60 pce and more preferably between 35 and 50 pce.

8. Tire (10) according to any one of the preceding claims, in which, the elastomeric composition comprising a reinforcing filler, the level of reinforcing filler is within a range from 5 to 70 phr, preferably from 5 to 60 phr, more preferably from 5 to 55 phr, even more preferably between 5 and 55 phr, very preferably between 10 and 50 phr and most preferably from 20 to 45 phr.

9. Tire (10) according to any one of the preceding claims, in which the reinforcing filler mainly comprises carbon black.

10. A tire (10) according to any one of the preceding claims, wherein the elastomeric matrix comprises at least one isoprene elastomer and at least one butadiene elastomer.

11. Tire (10) according to any one of the preceding claims, in which the elastomeric matrix comprises at least one butadiene elastomer at a rate within a range of 20 to 80 phr, preferably ranging from 30 to 70 phr, more preferably between 30 and 70 phr and even more preferably ranging from 35 to 65 phr.

12. Tire (10) according to any one of the preceding claims, in which the elastomeric matrix comprises at least one isoprene elastomer at a rate within a range of 20 to 80 phr, preferably ranging from 30 to 70 phr, more preferably between 30 and 70 phr and even more preferably ranging from 35 to 65 phr.

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