Tire with improved durability performance

Abstract

The invention relates to a tire that comprises sets (32, 34) of blocks and a tread layer comprising an elastomer material having a complex dynamic shear modulus G*1_60 > 0.85 MPa. The elastomer material is based on an elastomer matrix having a theoretical weighted glass transition temperature Tgt ≤ -91°C. The elastomer material has a reinforcing filler volume fraction of 20.0% or lower. The height of the tread pattern is 6.5 mm or greater. Each set (32, 34) comprises an incision comprising a portion exhibiting an undulation in the radial direction.

Description

Tires with improved, durable performance

[0001] The present invention relates to a tire for passenger vehicles. A tire is defined as a band designed to form a cavity by cooperating with a support element, for example, a rim, this cavity being capable or not of being pressurized to a pressure greater than atmospheric pressure. A tire according to the invention has a substantially toroidal structure of revolution around a principal axis of the tire.

[0002] We know from the prior art a four-season or all-season passenger vehicle tire described in particular in W02021 / 019174. Such a tire includes a tread intended to come into contact with the ground during rolling of the tire by means of a tread surface.

[0003] Despite its excellent performance, particularly on snow and wet surfaces, this state-of-the-art tire has a lifespan that could be improved, requiring its replacement relatively prematurely.

[0004] The invention aims to improve the performance trade-off between tire longevity and wet grip performance without degrading snow grip performance.

[0005] To this end, the invention relates to a tire comprising a crown comprising a tread comprising first and second main lateral cutouts, each first and second main lateral cutout extending: - axially from an axially external end of each first and second main lateral cutout to an axially internal end of each first and second main lateral cutout, - circumferentially from a circumferentially first azimuth of the inner axial end to a circumferentially second azimuth of the outer axial end, the circumferentially first azimuth entering the contact patch with the tire's running surface before the circumferentially second azimuth when the tire is mounted on a vehicle moving forward, the tread comprising first and second sets of at least one block, each first and second set of at least one block being circumferentially delimited at least in part by a pair respectively of two first and two second circumferentially successive lateral principal cutouts, each first and second set of at least one block comprising respectively a first axially inner and outer end and a second axially inner and outer end, the tread comprising a wearing layer carrying at least part of a tread surface, the wearing layer comprising an elastomeric material having a complex dynamic shear modulus G*1_60 measured according to ASTM D-5992-96, at a temperature of 60°C and a frequency of 10Hz under a stress equal to 0.7 MPa such that G*1_60 > 0.85 MPa, the elastomeric material being based on an elastomeric matrix having a theoretical weighted glass transition temperature Tgt < -91 °C, the theoretical weighted glass transition temperature Tgt being defined as the average of the glass transition temperature(s) of the elastomer(s) of the elastomeric matrix weighted by their percentage, expressed in pce, in the elastomeric matrix,the elastomeric material being based on at least one reinforcing filler comprising one or more reinforcing inorganic filler(s), the volume fraction of reinforcing inorganic filler(s) being less than or equal to 20.0%, the tread having a tread height greater than or equal to 6.5 mm, each first and / or second assembly comprising an incision extending at least partially respectively between the first axially inner and outer ends and / or between the second axially inner and outer ends, the incision comprising at least a portion having a corrugation in the radial direction.

[0006] The invention makes it possible to improve the performance trade-off between tire life and wet grip performance without degrading grip performance on snowy surfaces.

[0007] Indeed, the inventors behind the invention discovered a combination of features that, on the one hand, thanks to a first group of elastomeric material characteristics, improve tire lifespan at the cost of reduced wet grip, and on the other hand, thanks to a second group of tread pattern characteristics, at least partially restore wet grip while synergistically improving tire lifespan. Another key aspect of the invention is that the characteristics of the first and second groups maintain the same level of performance on snow-covered surfaces.

[0008] Before explaining the advantages of the invention in more detail, let us recall that to characterize the longevity of a tire, we generally distinguish between, on the one hand, the Tire wear performance is defined by two factors: mass loss performance, which characterizes the rate at which the tread can wear (for example, expressed in grams per kilometer), regardless of the amount of tread remaining; and tread life performance, which characterizes the total distance traveled before the tread is completely worn, for example, when one of the wear indicators is reached (regardless of the tread material). Longevity takes into account both performance factors, and neither can be sacrificed for the sake of the other.

[0009] The first set of characteristics concerns the elastomeric material and includes certain properties of the elastomeric material. Indeed, the presence of an elastomeric matrix with a relatively low theoretical weighted glass transition temperature, combined with a relatively high G*1_60 value and a relatively low volume fraction of reinforcing inorganic filler(s), increases tire life by improving mass loss performance. However, these last two characteristics (relatively high G*1_60 and the relatively low volume fraction of reinforcing inorganic filler(s)) have the drawback of degrading wet grip performance.

[0010] A second group of characteristics concerns the tire tread pattern and includes the tread depth and a characteristic of the groove size. A relatively large tread depth increases the depth of the grooves in the tread, thus promoting water evacuation and ultimately improving wet grip compared to a smaller tread depth. A relatively large tread depth also increases the amount of elastomeric material that wears down, thus extending tire life. However, a relatively large tread depth reduces the overall stiffness of the tread, leading to an increased abrasion rate of the elastomeric material and consequently a degradation in mass loss performance.To prevent the reduced tread stiffness, which degrades mass loss performance, from negatively offsetting the advantage of increased wear on elastomeric material, the inventors devised a method of stiffening each first and / or second assembly using radial corrugations. These corrugations bring the two parts of the assembly into contact as it passes through the contact patch, thus increasing its rigidity. This maintains mass loss performance.

[0011] A wave in the radial direction is such that, when moving radially along the radial portion, the incision in question presents several points The wave's inflection creates changes in direction. The wave can be regular, meaning it has a consistent period, or irregular. The changes in direction can be angular, for example, to form a crenellated wave, or curved, for example, to form a sinusoidal wave.

[0012] The undulation extends over at least a radial portion of the incision. For a given undulation, the larger the radial portion, the greater the rigidity. Thus, in some variations, the undulation may extend radially over the entire depth of the incision. In other variations, the undulation may extend radially only over the radial portion of the incision.

[0013] In some variations, the portion exhibiting the undulation along the radial direction may also exhibit undulation along another direction, for example, along a direction perpendicular to the radial direction. Such incisions are described, for example, in applications W02024049804 or WO2024049797.

[0014] The complex shear modulus G* under imposed stress is determined using a Metravib VA4000 or DMA+450 viscoanalyzer with test specimens containing a cured material extracted from the tire. The response of the specimens subjected to a sinusoidal alternating simple shear load at a frequency of 10 Hz under a force of 55 N is recorded. A temperature sweep is performed between -80°C and 80°C at a rate of 1.5°C / min after the specimens have been previously conditioned to 100% peak-to-peak strain at a temperature of 40°C or lower, for example, 23°C. The specimen has a cylindrical cross-section as described in ASTM D 5992-96 (2011 reapproved version, originally approved in 1996) in Figure X2.1 (circular embodiment) and has a diameter of 10 mm [0 to +0.04 mm] and a thickness of 2 mm [1.83–2.33]. Note that the force of 55 N is equivalent, in the case of a specimen with a diameter of 10.00 mm, to a peak-to-peak stress of 0.7 MPa. The complex shear modulus G* is measured at 60°C.

[0015] The volume fraction of reinforcing inorganic filler(s) is defined as the ratio of the volume of reinforcing inorganic filler(s) to the sum of the volumes of reinforcing filler(s), elastomer(s) and any plasticizer(s).

[0016] The glass transition temperatures of elastomers and resins are determined using a differential scanning calorimeter, according to the ASTM E1356-08 standard which dates from 2014.

[0017] The expression "based on" refers to a material comprising the mixture and / or the in situ reaction product of the various constituents used, some of these constituents having reacted with each other, at least partially, during the different phases of material manufacturing.

[0018] By the expression "part by weight per hundred parts by weight of elastomer" (or pce), it is to be understood in the sense of the present invention, the part, by mass per hundred parts by mass of elastomer.

[0019] In this application, unless expressly stated otherwise, all percentages (%) indicated are percentages (%) by mass.

[0020] In this application, "reinforcing inorganic filler" should be understood by definition as any inorganic or mineral filler (regardless of its color and whether natural or synthetic), also called "white" filler, "light" filler or even "non-black filler" as opposed to carbon black, capable of reinforcing on its own, without any other means than an intermediate coupling agent, a rubber composition intended for the manufacture of tires, in other words, capable of replacing, in its reinforcing function, a conventional carbon black of tire grade; such a filler is generally characterized, in a known way, by the presence of hydroxyl groups (-OH) on its surface.

[0021] The physical state in which the reinforcing inorganic filler is presented is irrelevant, whether it is in the form of powder, microbeads, granules, balls or any other suitable densified form.

[0022] Suitable inorganic reinforcing fillers include mineral fillers of the siliceous type, particularly silica (SiCk), or of the aluminous type, particularly alumina (Al₂O₃). The silica used may be any reinforcing silica known to those skilled in the art, including any precipitated or fumed silica with a BET surface area and a CTAB specific surface area both below 450 m² 2 / g, preferably from 30 to 400 m 2 / g. Examples of highly dispersible precipitated silicas (known as "HDS") include "Ultrasil 7000" and "Ultrasil 7005" silicas from Evonik, "Zeosil" 1165MP, 1135MP and 1115MP silicas from Solvay, "Hi-Sil EZ150G" silica from PPG, "Zeopol" 8715, 8745 and 8755 silicas from Huber, and silicas with a high specific surface area as described in application WO 03 / 016387.

[0023] A person skilled in the art will understand that, as a reinforcing inorganic filler, a reinforcing filler, in particular an organic one, could be used, provided that this reinforcing filler is covered with an inorganic layer such as silica, or has functional sites on its surface, in particular hydroxyl sites, requiring the use of a coupling agent to establish the bond between the filler and the elastomer.

[0024] Examples of other constituents of which the elastomeric material can be base of are described in W02021 / 005295.

[0025] Conventionally, the tread surface is axially delimited by first and second axial edges that coincide with the first and second axial edges of the tread, respectively. The first and second axial edges are determined on a tire mounted on a nominal rim and inflated to the nominal pressure as defined in the ETRTO 2023 standard manual. The first and second axial edges are positioned on either side of the tire's median plane and are formed by lines substantially parallel to the tire's circumferential direction. In the case of a clear boundary between the tread surface and the rest of the tire, the first and second axial edges are determined simply.In the case where the tread surface is continuous with the external surfaces of the sidewalls of the tire, the first and second axial edges are usually determined by loading the tire to 80% of its load capacity according to the ETRTO 2023 standard manual and the first and second axial edges are identified as the axial limits of the tread in contact with the ground.

[0026] The tread layer is designed to come into contact with the ground when the tire is new and at least until it reaches a predetermined wear threshold, such as a regulatory wear threshold. This regulatory wear threshold is indicated, in particular, by the presence of wear indicators in the tread.

[0027] A cutout or a portion of a cutout has two main characteristic dimensions: a width and a curvilinear length such that the curvilinear length is at least twice the width. A cutout or a portion of a cutout is therefore delimited by at least two main lateral faces determining its curvilinear length and connected by a base, the two main lateral faces being separated by a non-zero distance, called the width of the cutout or portion of the cutout.

[0028] The principal direction of a cut is the direction along which the curve equidistant from each edge of the cut to the radial dimension of the running surface passes. The curvilinear length is the length measured along this curve equidistant from each edge of the cut to the radial dimension of the running surface, between each end of the cut. The mean direction is the shortest curve joining the two ends of the cut.

[0029] The width of a cut or portion of a cut, on a new tire, is the distance between the two main side faces measured at a specific radial dimension. The width is measured approximately perpendicular to the Main side faces. The maximum width of a cutout or portion is the maximum value of the widths of the cutout or portion. In the case where the cutout or portion of a cutout includes a chamfer, the maximum width is determined without taking the chamfer into account, that is to say on the radial sides radially inside the chamfer.

[0030] The depth of a cut or portion of a cut on a new tire is the radial distance between the bottom of the cut or portion and its projection onto the ground when the tire is in motion. The maximum depth of the tread cuts is called the tread depth. Preferably, the maximum depth of the cuts in the central portion of the tread, as described later, is called the tread depth. The maximum depth of a cut or portion is the maximum depth of the cut or portion. If the cut or portion of the cut includes a chamfer, the maximum depth is determined taking the chamfer into account.

[0031] A cutout or a portion of a cutout can be transverse or circumferential.

[0032] A cut or cross-section is such that the cut extends along an average direction forming an angle strictly greater than 30°, preferably greater than or equal to 45°, with the circumferential direction of the tire, i.e., forming an angle less than or equal to 60°, preferably strictly less than 45°, with the axial direction of the tire. A cut or cross-section may be continuous, i.e., not interrupted by a tread block or another cut, so that the two principal lateral faces determining its length are uninterrupted along the length of the cross-section or cross-section.A cut or a cross-section may also be discontinuous, that is, interrupted by one or more blocks of sculpture and / or one or more cutouts so that the two main lateral faces determining its length are interrupted by one or more blocks of sculpture and / or one or more cutouts.

[0033] A cut or circumferential portion is such that the cut or portion extends along an average direction forming an angle less than or equal to 30°, preferably less than or equal to 10°, with the circumferential direction of the tire, that is to say, forming an angle strictly greater than 60°, preferably strictly greater than 80°, with the axial direction of the tire. In the case of a continuous circumferential cut, the two ends coincide and are joined by a curve making a complete turn around the tire. A cut or a A circumferential portion can be continuous, meaning it is not interrupted by a tread block or other cut, so that the two main lateral faces defining its length are uninterrupted over the entire circumference of the tire. A circumferential cut can also be discontinuous, meaning it is interrupted by one or more tread blocks and / or one or more cuts, so that the two main lateral faces defining its length are interrupted by one or more tread blocks and / or one or more cuts over the entire circumference of the tire.

[0034] The tire according to the invention has a substantially toroidal shape around an axis of revolution substantially coinciding 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.

[0035] Axial direction refers to the direction substantially parallel to the axis of revolution of the tire, that is, the axis of rotation of the tire.

[0036] By circumferential direction, we mean the direction which is substantially perpendicular to both the axial direction and to a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire).

[0037] By radial direction, we mean 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.

[0038] 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 mid-axial distance of the two ribs and passes through the axial midpoint of the crown reinforcement.

[0039] The circumferential equatorial plane of a tire, in a meridional cross-section, is defined as the plane passing through the tire's equator, perpendicular to the median plane and the radial direction. The tire's equator, in a meridional cross-section (a plane perpendicular to the circumferential direction and parallel to the radial and axial directions), is the axis parallel to the tire's axis of rotation and located equidistant between the outermost radial point of the tread intended to be in contact with the ground and the innermost radial point of the tire intended to be in contact with a support, such as a rim.

[0040] By meridian plane, we mean a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0041] Radially inside and radially outside, respectively, refer to the part closest to and furthest from the tire's axis of rotation. Axially inside and axially outside, respectively, We hear closer to the median plane of the tire, respectively further from the median plane of the tire.

[0042] The bead is the portion of the tire designed to allow the tire to be attached to a mounting surface, such as a wheel with a rim. Each bead is specifically designed to make contact with a hook on the rim, enabling it to be secured.

[0043] Any range of values ​​designated by the expression "between a and b" represents the range of values ​​from more than a to less than b (i.e., bounds a and b excluded) while any range of values ​​designated by the expression "from a to b" means the range of values ​​from a to b (i.e., including the strict bounds a and b).

[0044] Unless otherwise stated, any angle made between two directions is the smallest of the angles made by those two directions with each other.

[0045] In preferred embodiments of the invention, the tires are intended for passenger cars or light trucks as defined in the European Tyre and Rim Technical Organisation (ETRTO) standard, 2023. Such a tire has a cross-section in a meridional plane characterized by a section height H and a nominal section width or bead size S as defined in the European Tyre and Rim Technical Organisation (ETRTO) standard, 2023, such that the H / S ratio, expressed as a percentage, is at most 90 and at least 20, and the nominal section width S is at least 115 mm and at most 385 mm. Furthermore, the hook diameter D, defining the diameter of the tire's mounting rim, is at least 12 inches and at most 30 inches.

[0046] Due to the nature of the invention, the tires are preferably all-season, all-season, or winter tires. Winter tires are identified by the M+S marking (M+S being the acronym for "Mud + Snow") and / or the 3PMSF marking (3PMSF being the acronym for "3 Peak Mountain Snow Flake"). All-season tires, due to their performance on snow, also display the M+S and / or 3PMSF markings. Unlike the preferred all-season, all-season, or winter tires, a summer tire does not have the M+S or 3PMSF markings.

[0047] In advantageous and optional embodiments, Tgt > -108°C, preferably Tgt > -105°C, more preferably Tgt > -100°C and very preferably Tgt > -98°C.

[0048] Optionally, in variants maximizing mass loss performance, Tgt < -94°C, preferably Tgt < -95°C.

[0049] Optionally, in variants maximizing resistance performance at rolling, Tgt > -96°C, preferably Tgt > -94°C.

[0050] In advantageous and optional embodiments, the elastomeric matrix comprises at least one butadiene-styrene based copolymer having a glass transition temperature less than or equal to -60°C.

[0051] For the purposes of this invention, a "butadiene-styrene copolymer" is any copolymer obtained by copolymerizing one or more styrenic compounds with one or more butadiene compounds. Suitable styrene monomers include, in particular, styrene, methylstyrene, para-tert-butylstyrene, methoxystyrene, and chlorostyrene. Suitable butadiene monomers include, in particular, 1,3-butadiene. These elastomers can have any microstructure that depends on the polymerization conditions used, including the presence or absence of a modifying and / or randomizing agent and the quantities of such agent used. For example, the elastomers can be block, statistical, sequenced, or microsequenced. Such butadiene- and styrene-based copolymers can be obtained by a process as described in W02021 / 005295.

[0052] In advantageous and optional embodiments, the elastomeric matrix comprises at least one polybutadiene having a glass transition temperature less than or equal to -80°C.

[0053] Polybutadiene (abbreviated as BR) refers to a well-known rubber compound manufactured by polymerizing the 1,3-butadiene monomer (typically a homopolymerization) in a solution polymerization process using appropriate catalysts known to those skilled in the art. Due to the two double bonds present in the butadiene monomer, the resulting polybutadiene can exist in three different forms: cis-1,4, trans-1,4, and vinyl-1,2. The cis-1,4 and trans-1,4 elastomers are formed by the monomers connecting end-to-end, while the vinyl-1,2 elastomer is formed by the monomers connecting between the ends of the monomer. The choice of catalyst and the process temperature are known to be the variables generally used to control the cis-1,4 bonding content of the polybutadiene.Such polybutadienes can be produced using a neodymium catalyst in a manner well known to those skilled in the art, for example according to a process described in document JP 60 / 23406 A and WO 03 / 097708 A1. Such polybutadienes are also commercially available, for example, Buna® CB 22 marketed by Lanxess.

[0054] In advantageous and optional embodiments, the butadiene-styrene based copolymer or copolymers is a butadiene-styrene copolymer (SBR).

[0055] It should be noted that SBR can be prepared as an emulsion (ESBR) or as a solution (SSBR). Whether ESBR or SSBR, SBR can have any microstructure compatible with a glass transition temperature below -60°C. Specifically, the butadiene-styrene copolymer can have a styrene content between 1% and 15% by weight, and more particularly between 1% and 5%, and a 1,2-linkage content (molar %) of the butadiene moiety between 4% and 25%. Advantageously, each butadiene-styrene copolymer is an SSBR.

[0056] In advantageous and optional embodiments, the butadiene and styrene-based copolymer or copolymers have a glass transition temperature in the range of -110°C to -60°C, preferably -110°C to -70°C, more preferably -100°C to -80°C, and even more preferably -95°C to -80°C.

[0057] In advantageous and optional embodiments, the proportion of the butadiene and styrene-based copolymer(s) in the elastomeric material of the wearing course is greater than or equal to 40 parts per annum, preferably 50 parts per annum, and more preferably is in the range of 50 to 85 parts per annum.

[0058] A relatively moderate level of butadiene and styrene-based copolymer maximizes mass loss performance.

[0059] Optionally, in variants maximizing mass loss performance, the proportion of butadiene and styrene based copolymer(s) in the elastomeric material of the wearing course is preferably in the range of 50 to 70 parts per cent.

[0060] Optionally, in variants maximizing rolling resistance performance, the proportion of butadiene and styrene based copolymer(s) in the elastomeric material of the wearing course is preferably in the range of 65 to 85 parts per cent.

[0061] In advantageous and optional embodiments, the glass transition temperature of the polybutadiene or each polybutadiene is within a range of -120°C to -80°C, preferably from -115°C to -100°C.

[0062] In advantageous and optional embodiments, the proportion of polybutadiene(s) in the elastomeric material of the wearing course is in the range of 5 to 50 parts per annum, preferably 15 to 50 parts per annum.

[0063] A relatively high polybutadiene(s) content helps to maximize mass loss performance.

[0064] Optionally, in variants maximizing mass loss performance, the proportion of polybutadiene(s) in the elastomeric material of the layer of rolling stock, is included in a range preferably from 30 to 50 pieces.

[0065] Optionally, in variants maximizing rolling resistance performance, the proportion of polybutadiene(s) in the elastomeric material of the wearing course is preferably in a range of 15 to 35 parts per cent.

[0066] In advantageous and optional embodiments, the polybutadiene or polybutadiene(s) have a molar percentage of cis-1,4 chains greater than 90%, more preferably greater than 95%. Such polybutadienes can be produced using a neodymium catalyst in a manner well known to those skilled in the art, for example, according to a process described in documents JP60 / 23406A, WO0238636A1, or W003 / 097708A1. Such polybutadienes are also commercially available, for example, Buna® CB 22 marketed by Lanxess.

[0067] In advantageous and optional embodiments, the proportion of isoprene elastomer in the elastomeric material of the wearing course is preferably less than 14 parts per million, preferably less than 10 parts per million, preferably less than 5 parts per million, and preferably less than 4 parts per million. Particularly advantageously, the elastomeric material of the wearing course is free of isoprene elastomer. Thus, advantageously, the total proportion of butadiene-styrene and polybutadiene copolymer in the elastomeric material of the wearing course is 100 parts per million.

[0068] Advantageously, the reinforcing filler predominantly comprises one or more inorganic reinforcing fillers, preferably one or more silicas. For the purposes of this invention, "predominant" means that this compound or these compounds constitute the majority of the compounds of the same type in the elastomeric material; that is, it is the one that represents the largest quantity by mass among the compounds of the same type. Thus, a so-called "major" filler is that which represents the largest mass among the fillers in the elastomeric material. Preferably, "major" means present at more than 50%, preferably more than 60%, 70%, 80%, 90%, for example, 100%.

[0069] Thus, in advantageous and optional embodiments, where the elastomeric material is based on one or more silicas, the silica volume fraction is less than or equal to 20.0%. The silica volume fraction is then defined as the ratio of the volume of silica to the sum of the volumes of reinforcing filler(s), elastomer(s), and any plasticizer(s).

[0070] In advantageous and optional embodiments, the volume fraction of reinforcing inorganic filler(s) is less than or equal to 19.5%. Preferably, the elastomeric material being based on one or more silica(s), the volume fraction of silica(s) is less than or equal to 19.5%.

[0071] Optionally, in variants maximizing rolling resistance performance, the volume fraction of reinforcing inorganic filler(s) is less than or equal to 19.0%, preferably 18.5%. Preferably, the elastomeric material being based on one or more silicas, the volume fraction of silica is less than or equal to 19.0%, preferably 18.5%, and more preferably 18.5%.

[0072] In optional but advantageous embodiments, the volume fraction of reinforcing inorganic filler(s) is greater than or equal to 17.0%, preferably 17.5%. Preferably, the elastomeric material being based on one or more silicas, the volume fraction of silica is greater than or equal to 17.0%, preferably 17.5%.

[0073] Optionally, in variants maximizing mass loss performance, the volume fraction of reinforcing inorganic filler(s) is greater than or equal to 18.0%, preferably 18.5%, and more preferably 19.0%. Preferably, the elastomeric material being based on one or more silicas, the volume fraction of silica is greater than or equal to 18.0%, preferably 18.5%, and more preferably 19.0%.

[0074] Optionally, in variants maximizing rolling resistance performance, the volume fraction of reinforcing inorganic filler(s) is greater than or equal to 18.0%. Preferably, the elastomeric material being based on one or more silicas, the volume fraction of silica is greater than or equal to 18.0%.

[0075] In optional and advantageous embodiments, the rate of reinforcing inorganic filler(s) and more preferably the rate of silica(s), in the elastomeric material of the tread of the tire can be in a range of 80 to 200 parts per annum, preferably 90 to 150 parts per annum, preferably 90 to 130 parts per annum.

[0076] In some embodiments, the reinforcing filler comprises at least one organic reinforcing filler, preferably carbon black.

[0077] Suitable as organic reinforcing fillers are, in particular, carbon blacks or functionalized polyvinyl organic fillers as described in applications WO-A-2006 / 069792, WO-A-2006 / 069793, WO-A-2008 / 003434 and WO-A-2008 / 003435. All carbon blacks are suitable as carbon blacks, including so-called pneumatic-grade blacks. Among the latter, the following are particularly noteworthy: particularly reinforcing carbon blacks of the 100, 200, or 300 series (ASTM grades), for example, NI 15, N134, N234, N326, N330, N339, N347, N375, or, depending on the intended application, blacks of higher series (e.g., N660, N683, N772). Carbon blacks could, for example, already be incorporated into an isoprene elastomer in the form of a masterbatch (see, for example, applications WO 97 / 36724 or WO 99 / 16600).

[0078] Optionally, the rate of any carbon black in the elastomeric material of the wearing course is in a range of 0.1 to 10 pc, more preferably from 0.5 to 10 pc.

[0079] In optional but advantageous embodiments, where the elastomeric material is based on one or more plasticizers, the volume fraction of plasticizer(s) is less than or equal to 32.0%, preferably 31.5%, and more preferably 31.0%. Similar to the first set of characteristics concerning the elastomeric material, a relatively low volume fraction of plasticizer(s) improves mass loss performance.

[0080] The volume fraction of plasticizer(s) is defined as the ratio of the volume of silica(s) to the sum of the volumes of filler(s), elastomer(s) and plasticizer(s).

[0081] Optionally, in variants maximizing mass loss performance, the volume fraction of plasticizer(s) is less than or equal to 30.5%.

[0082] In optional and advantageous embodiments, the volume fraction of plasticizer(s) is greater than or equal to 28.0%, preferably 28.5%, more preferably 29.0%, even more preferably 29.5% and very preferably 30.0%.

[0083] Optionally, in variants maximizing rolling resistance performance, the volume fraction of plasticizer(s) is greater than or equal to 30.5%, preferably 31.0%.

[0084] In optional but advantageous embodiments, the elastomeric material is based on at least one plasticizer comprising at least one plasticizing resin, the proportion of the plasticizing resin(s) may be in the range of 25 to 100 parts per annum, preferably 50 to 100 parts per annum, more preferably 55 to 90 parts per annum, the plasticizing resin(s) having a glass transition temperature above 20°C.

[0085] The term "resin" is reserved in this application, by definition known to those skilled in the art, for a compound that is solid at room temperature (23°C), as opposed to a liquid plasticizing compound such as an oil. Examples of plasticizing resins are described in more detail in WO2021 / 005295.

[0086] Although not necessary for the implementation of the present invention, the plasticizer(s) of the elastomeric material of the tire tread may include a liquid plasticizer at 23°C, for example such as those described in WO2021 / 005295.

[0087] Although not necessary for the implementation of the present invention, the plasticizer(s) of the elastomeric material of the tire tread may comprise a plasticizing resin viscous at 20°C, that is to say which by definition has a Tg in a range from -40°C to -20°C, for example like those described in WO2021 / 005295.

[0088] In optional and advantageous embodiments, the average pitch Pm between two first and / or two second circumferentially successive main lateral cutouts is such that Pm < 27 mm, preferably Pm < 26 mm.

[0089] A relatively small pitch (Pm) allows for an increase in the number of first and second sets, and therefore the number of transverse edges in the tread. This improves grip performance on snow-covered surfaces.

[0090] In optional and advantageous embodiments, Pm>23 mm, preferably Pm>24 mm.

[0091] The average pitch is calculated by dividing the circumference on the median plane of the tire measured on a tire inflated to 2.5 bars and unloaded by the number of first and / or second circumferentially successive main lateral cuts of pattern present on this circumference.

[0092] In optional and advantageous embodiments, G*1_60 > 0.90 MPa, preferably G*1_60 > 0.95 MPa.

[0093] A relatively high value of the complex shear modulus G* further improves the mass loss performance of the tire.

[0094] Optionally, in variants maximizing mass loss performance, G*1_60 > 1.00 MPa, preferably G*1_60 > 1.05 MPa.

[0095] In optional and advantageous embodiments, G*1_60 < 1.50 MPa, preferably G*1_60 < 1.20 MPa, more preferably G*1_60 < 1.15 MPa and very preferably G*1_60 < 1.10 MPa.

[0096] A relatively low value of the complex shear modulus G* improves adhesion performance on wet surfaces.

[0097] Optionally, in variants maximizing rolling resistance performance, G*1_60 < 1.05 MPa, preferably G*1_60 < 1.00 MPa.

[0098] In optional but advantageous embodiments, the curvilinear length of the portion of the incision bearing the undulation or the total curvilinear lengths of the portions of the incision exhibiting the undulation of each first and / or second set is greater than or equal to 25%, preferably 30% of the curvilinear length of the incision.

[0099] In optional but advantageous embodiments, the radial height of the radial portion over which the undulation extends is greater than or equal to 30%, preferably 40% and more preferably 50% of the depth of the incision.

[0100] In order to calculate this percentage in cases where the radial height and / or depth is or are variable, we will average the ratios between each radial height and each depth of the incision.

[0101] In optional and advantageous embodiments, each first and / or second set of at least one block comprises: - an axially internal portion, - an axially external portion arranged axially outside the axially internal portion, the axially external portion of each first and / or second set of at least one block includes at least one portion of the incision exhibiting an undulation in the radial direction on at least one radial portion of said portion of the incision.

[0102] In optional embodiments, the axially inner portion is the portion of each first and / or second set closest to the median plane of the tire and the axially outer portion is the portion of each first and / or second set closest to the first and / or second axial edge of the tread.

[0103] Indeed, inventors understood that tire wear resulted from two different phenomena, one local and the other global. They understood that local wear followed a rule whereby a portion of the tread with relatively high rigidity compared to its neighboring portions wore out more quickly than a portion with relatively low rigidity compared to its neighboring portions. They also understood that global wear, unlike local wear, followed a rule whereby the lower the tread's rigidity, the faster it wore out.

[0104] Thanks to the radial corrugation, the outer axial portion is locally stiffened relative to the inner axial portion. This promotes wear on the outer axial portion compared to the inner axial portion. Consequently, tread wear is better distributed, increasing tire life.

[0105] In addition, this stiffening makes it possible to compensate for the flexibility provided by the relatively large height of the sculpture and therefore to maintain a relatively high overall stiffness which promotes the performance of mass loss.

[0106] In optional and advantageous embodiments, the axially inner portion extends along a principal direction different from the principal direction along which the axially outer portion extends, preferably the axially inner portion extends along a principal direction forming with the axial direction an angle strictly greater than the angle formed with the axial direction by a principal direction along which the axially outer portion extends.

[0107] Such sections allow the water to flow more closely into contact with the tread, thus improving grip performance on wet surfaces.

[0108] The principal direction in which a portion of a block set extends is the average direction in which the leading edge of that portion extends. As is known to those skilled in the art, the leading edge of a portion of a block set is the edge of that portion which, for a given circumferential line, enters the contact area before the other edge, called the trailing edge.

[0109] In advantageous and optional embodiments, the axially inner portion extends along a principal direction forming with the axial direction an angle ranging from 30° to 90°, preferably from 40° to 70° and more preferably from 45° to 65°.

[0110] In advantageous and optional embodiments, the axially external portion extends along a principal direction forming with the axial direction an angle ranging from 0° to 30°, preferably from 0° to 20° and more preferably from 0° to 10°.

[0111] In optional and advantageous embodiments, each first and / or second set comprises an axially intermediate portion arranged axially between the axially inner portion and the axially outer portion, the axially intermediate portion of each first and / or second set of at least one block comprises at least one portion of the incision having a waviness in the radial direction on at least one radial portion of said portion of the incision.

[0112] Thanks to the radial corrugation, and for the same reasons as those mentioned for the outer axial portion, the intermediate axial portion is locally stiffened relative to the inner axial portion. This promotes wear on the intermediate axial portion compared to the inner axial portion. Consequently, tread wear is better distributed, and tire life is increased.

[0113] In optional and advantageous embodiments, the axially intermediate portion extends along a principal direction different from the principal direction along which the axially inner portion extends and different from the principal direction along which the axially outer portion extends, preferably the axially intermediate portion extends along a principal direction forming with the axial direction an angle strictly greater than the angle formed with the axial direction by a principal direction along which the axially outer portion extends and strictly less than the angle formed with the axial direction by a principal direction along which the axially inner portion extends.

[0114] Such sections allow for an even more optimized adaptation to the flow lines of water flowing in contact with the tread, thus optimizing grip performance on wet surfaces.

[0115] In advantageous and optional embodiments, the axially intermediate portion extends along a principal direction forming with the axial direction an angle ranging from 10° to 50°, preferably from 15° to 45° and more preferably from 20° to 40°.

[0116] In optional and advantageous embodiments, the axially internal portion and / or the axially intermediate portion and / or the axially external portion of each first and / or second set of at least one block comprises at least one portion of the incision having: - a width varying with the depth of said portion such that the width of said portion decreases and then increases when moving radially along said portion so as to form a local width reduction and / or - an undulation along the general direction of said portion, and / or - a depth varying along said portion such that the depth of said portion decreases and then increases when moving along said portion so as to form a local bridge.

[0117] Local width reduction and / or undulation along the general direction and / or local bridging optimizes tread stiffening and thus promotes mass loss performance.

[0118] The undulation along the general direction of said portion is such that the general direction exhibits several inflection points when moving along it, creating changes in direction. The undulation can be regular, i.e., exhibiting a period, or irregular. The changes in direction of the general direction can be angular, for example, to form a crenellated undulation, or curved, for example, to form a... sinusoid.

[0119] Local bridging allows the two parts of the whole to be connected, at least one block in which the incision is made.

[0120] In optional and advantageous embodiments, the elastomeric material has a complex dynamic shear modulus G*1_-20 measured according to ASTM D-5992-96, at a temperature of -20°C and a frequency of 10Hz under a stress of 0.7 MPa such that G*1_-20 > 3 MPa, preferably G*1_-20 > 6 MPa.

[0121] A relatively high value helps to avoid excessively degrading the grip performance on wet surfaces.

[0122] In optional and advantageous embodiments, the elastomeric material has a complex dynamic shear modulus G*1_-20 measured according to ASTM D-5992-96, at a temperature of -20°C and a frequency of 10Hz under a stress of 0.7 MPa such that G*1_-20 < 10 MPa, preferably G*1_-20 < 8 MPa.

[0123] A relatively low value helps to improve traction performance on snowy surfaces.

[0124] In optional and advantageous embodiments, the elastomeric material has a glass transition temperature Tg_1 such that Tg_1 < -20°C, preferably Tg_1 < -24°C and more preferably Tg_1 < -26°C.

[0125] A relatively low glass transition temperature helps improve traction performance on snowy surfaces.

[0126] In optional and advantageous embodiments, the elastomeric material has a glass transition temperature Tg_1 such that Tg_1 > -30°C, preferably Tg_1 > -28°C.

[0127] Thanks to the presence of one or more polybutadiene compounds, which inherently exhibit relatively high adhesion performance on snow-covered surfaces, it is possible to use an elastomeric material with a glass transition temperature that is not excessively low, thus avoiding significant degradation of wet grip performance. Indeed, by using a glass transition temperature that is not excessively low, it is possible to obtain a relatively flexible elastomeric material at operating temperatures, which is quite favorable for good wet grip performance.

[0128] The glass transition temperature (Tg) is determined using a Metravib VA4000 or DMA+450 viscoanalyzer with test specimens containing a baked material extracted from the tire. The response of Specimens are subjected to sinusoidal alternating simple shear loading at a frequency of 10 Hz under a force of 55 N. A temperature sweep is performed between -80°C and 80°C at a rate of 1.5°C / min. The specimen has a cylindrical cross-section as described in ASTM D 5992-96 (2011 re-approved version, originally approved in 1996) in Figure X2.1 (circular embodiment) and has a diameter of 10 mm [0 to +0.04 mm] and a thickness of 2 mm [1.83-2.33]. Note that the force of 55 N is equivalent, in the case of a specimen with a diameter of 10.00 mm, to a stress with a peak-to-peak amplitude of 0.7 MPa. The glass transition temperature Tg is taken to be equal to the temperature at which the value of the tangent of the phase angle tanD is maximum. The tangent tanD of the phase angle D between the force exerted on the sample and its displacement represents a dynamic loss and is equal to the ratio G” / G’.

[0129] In optional but advantageous embodiments, the elastomeric material has a dynamic loss tanDMAX23_1 measured according to ASTM D-5992-96 at a temperature of 23°C and a frequency of 10Hz such that tanDMAX23_1 < 0.40.

[0130] The relatively low mass fraction of reinforcing inorganic filler(s) not only increases tire lifespan by improving the abrasion resistance of the elastomeric material, but also reduces the dissipation of the elastomeric material and thus lowers the tire's rolling resistance. Indeed, the less filler the elastomeric material contains, the less it dissipates.

[0131] Optionally, in variants maximizing rolling resistance performance, tanDMAX23_1 < 0.37, more preferably tanDMAX23_1 < 0.35 and even more preferably tanDMAX23_1 < 0.33.

[0132] In optional but advantageous embodiments, tanDMAX23_1 > 0.30.

[0133] Optionally, in variants maximizing mass loss performance, tanDMAX23_1 > 0.30, preferably tanDMAX23_1 > 0.33.

[0134] The dynamic loss tanDMAX23 or tanDMAX25 is another well-known dynamic property for those skilled in the art and is measured on the same Metravib VA4000 or DMA+450 viscoanalyzer using specimens containing a cured material extracted from tires. The response of the specimens subjected to a sinusoidal alternating simple shear load at a frequency of 10 Hz is recorded under specified temperature conditions (here 23°C for tanDMAX23 and 25°C for tanDMAX25) according to ASTM D1349-99. A strain amplitude sweep is performed from 0.1% cc to 100% cc (forward cycle), then from 100% cc at 0.1% cc (return cycle), cc meaning peak-to-peak. The specimen has a cylindrical cross-section as described in ASTM D 5992-96 (2011 re-approved version, originally approved in 1996) in Figure X2.1 (circular embodiment) and has a diameter of 10 mm [0 to +0.04 mm] and a thickness of 2 mm [1.83-2.33]. The tangent tanD of the phase angle D between the force exerted on the specimen and its displacement represents a dynamic loss and is equal to the ratio G” / G’. The maximum value tanDMAX of the tangent tanD of the phase angle D observed during the return cycle of deformation is recorded.

[0135] In optional but advantageous embodiments, the tire has a tread height ranging from 6.5 mm to 7.4 mm, preferably ranging from 6.5 mm to 7.2 mm.

[0136] In optional but advantageous embodiments, each first and second axially internal end of each first and second set of at least one block delimits at least in part a central cut extending over the entire circumference of the tire.

[0137] The central cutout allows efficient evacuation of water from the inside of the contact area to its outside by means of the main lateral cutouts and thus significantly improves the grip of the tire on wet ground.

[0138] The central cut extends around the entire circumference of the tire. In one variation, the central cut extends continuously around the entire circumference of the tire. By "continuously," we mean that air can flow freely around the circumference of the tire exclusively through the central cut. In another variation, the central cut extends discontinuously around the entire circumference of the tire. In this variation, air cannot flow freely around the circumference of the tire exclusively through the central cut, for example, due to the presence of tread elements arranged within the central cut, such as blocks.

[0139] Each first and second axially inner end of each first and second assembly delimits at least partially at least one central cutout. In one variant, each first and second axially inner end of each first and second assembly delimits the same central cutout. In another variant, each first axially inner end of each first assembly delimits a first central cutout extending around the entire circumference of the tire, and each second axially inner end of each second assembly delimits a second central cutout extending around the entire circumference of the tire, the second central cutout being distinct from the first central cut.

[0140] Optionally and advantageously, in order to facilitate the evacuation of water from the central cutout, each first and second main lateral cutout opens directly into at least one central cutout.

[0141] By directly, we mean that each first and second main lateral cut and the center cut or cut are connected to each other without the intermediary of other cuts in the tread.

[0142] In some embodiments, the central cut extends around the entire circumference of the tire in a general direction forming a substantially constant angle with the circumferential direction of the tire. Preferably, the substantially constant angle formed by the general direction of the central cut and the circumferential direction is less than or equal to 5°, and more preferably substantially zero. A constant angle means that the angle is the same for every azimuth of said central cut.

[0143] In other embodiments, the central cut extends over the entire circumference of the tire in a general direction forming a variable angle with the circumferential direction of the tire, and preferably such that: - each first axially internal end of each first assembly delimits at least in part one of the second main lateral cutouts forming part of the central cutout(s), and - each second axially internal end of each second set delimits at least in part one of the first main lateral cutouts forming another part of the or each central cutout.

[0144] A variable angle means that the angle takes on at least two different values ​​at at least two different azimuths of the central cut. In some variations, the general direction follows a curved line in the shape of a sinusoid. In other variations, the general direction follows a broken line in the shape of a zigzag.

[0145] Preferably, the central groove has a width ranging from 2.0 to 12.0 mm, and more preferably from 4.0 to 8.0 mm. A central groove that is too wide could reduce the tire's ability to compact snow within it, thus reducing the transmission of forces between the tire and the snow-covered ground. A groove that is too narrow would reduce the amount of snow stored and therefore the tire's ability to promote snow-on-snow contact between the snow stored in the central groove and the snow-covered ground.

[0146] In optional but advantageous embodiments, the apex includes a crown reinforcement comprising a reinforcing reinforcement comprising several helically wound textile reinforcing wire elements, the reinforcing reinforcement being arranged radially within the tread, the crown and the tread comprising an axially central portion extending over an axial width equal to 50% of the axial width of the tread surface and axially centered on the median plane of the tire, the axially central portion of the tread comprising at least one deepest cut of the axially central portion of the tread, in the axially central portion of the crown, the average radial distance E1m between: - the surface passing through the radially innermost point of the deepest cut made in the axially central portion of the tread and substantially parallel to the tread surface, and - the radially outer surface passing through the radially outermost points of the most radially outermost reinforcing elements among the reinforcing elements of the radially outermost layer arranged vertically above the axially central portion of the tread, is such that E1m < 2.30 mm, preferably E1m < 2.20 mm and more preferably E1m < 2.00 mm.

[0147] The relatively small value of E1m allows for a reduction in the material thickness between the two surfaces described above, thereby reducing the shear stress between the tread and the crown reinforcement. This, in turn, reduces heat dissipation in the tire crown and ultimately, the tire's rolling resistance. Most importantly, the inventors discovered that this relatively small average radial distance E1m also stiffens the tire crown, thus reducing the abrasion rate of the tread's elastomeric material and improving mass loss performance.

[0148] The determination of the average radial distance E1m is carried out in the axially central portion of the crown and tread by measuring, between the surfaces, several axially distributed radial distances across the axial width of the axially central portion of the tread. For example, a distance will be measured every centimeter along the axial direction, starting from the first and second axial edges of the axially central portion of the tread. Obviously, if the outermost radial point of the outermost reinforcing element is radially outside the surface passing through the innermost radial point of each cut, the If the cut is deeper and substantially parallel to the running surface, the measured radial distance is considered negative. Conversely, and in the vast majority of cases, if the outermost radial point of the outermost radially reinforcing element is radially inside the surface passing through the innermost radially point of the cut(s) that are deepest and substantially parallel to the running surface, the measured radial distance is considered positive.

[0149] These measurements will be taken in several equally spaced meridian planes around the circumference of the tire, for example, in four meridian planes. The radial distances thus measured will then be averaged to obtain the average radial distance E1m.

[0150] Radial distance between two surfaces means the straight distance between a point on one of the surfaces and its projection onto the other surface along the radial direction of the tire.

[0151] By the vertical of the axially central portion of the tread, we mean the radially outer surface resulting from the projection in the radial direction of said axially central portion of the tread onto the radially outer surface passing through the radially outermost points of the most radially outer reinforcing elements among the reinforcing elements of the radially outermost layer.

[0152] A matrix is ​​said to be polymeric because it is based on a polymeric material, this polymeric material being able to include 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 materials for tires, in particular materials for embedding reinforcement elements.

[0153] Preferably, the polymer matrix is ​​an elastomeric matrix. By elastomeric matrix is ​​meant a matrix exhibiting elastomeric behavior in the crosslinked state. Such a matrix is ​​advantageously obtained by crosslinking a composition comprising at least one elastomer and at least one other component. Preferably, the composition, based on at least one elastomer and at least one other component, comprises an elastomer, a crosslinking system, and a filler. The compositions used for these layers are conventional compositions for calendering reinforcements, typically based on natural rubber or another diene elastomer, a reinforcing filler such as carbon black, a vulcanizing system, and standard additives. The adhesion between the wire reinforcement elements and the matrix in which they are embedded is ensured for example by a usual adhesive composition, for example an RFL type glue or equivalent glue such for example as described in W02013017421 or W02017168109.

[0154] A reinforcing element is defined as an element that provides mechanical reinforcement to the polymer matrix in which it is embedded. Preferably, each reinforcing element is wire-like, meaning that each element has a length at least 10 times greater than the longest dimension of its cross-section, regardless of the cross-section's shape: circular, elliptical, oblong, polygonal, and in particular rectangular, square, or oval. In the case of a rectangular cross-section, the wire-like reinforcing element is in the form of a strip.

[0155] In optional but advantageous embodiments allowing effective preservation of the top reinforcement from corrosive agents, E1m > 0.50 mm, preferably E1m > 1.00 mm and more preferably E1m > 1.80 mm.

[0156] In some embodiments, the top reinforcement includes a shrink-fit reinforcement, and the radially outermost layer is a shrink-fit layer.

[0157] Conventionally, the shrink-fit reinforcement comprises several substantially parallel textile shrink-fit wire reinforcement elements embedded in the polymer matrix. In some embodiments, the shrink-fit reinforcement comprises a strip wound helically in several circumferential turns, the strip comprising several substantially parallel textile shrink-fit wire reinforcement elements embedded in the polymer matrix.

[0158] Advantageously, each wire reinforcement element of textile wrapping extends along a main wrapping direction forming, 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°.

[0159] Conventionally, the top reinforcement comprises a working reinforcement arranged radially inside the restraint reinforcement. The working reinforcement advantageously comprises at least one working layer, each working layer or layers comprising wire reinforcing elements extending substantially parallel to each other within each working layer. The wire reinforcing elements are preferably metallic wire elements. Preferably, in embodiments in which the working reinforcement comprises a radially inner working layer and a radially outer working layer arranged radially outside the radially inner working layer, the principal direction in which each wire reinforcing working element of the innermost radially working layer extends is defined by the main direction in which the restraint extends. Each wire reinforcement element of the outermost radially working layer forms opposite angles with the circumferential direction of the tire. These opposite angles may have equal or different absolute values.

[0160] Advantageously, the wire reinforcement elements of the or each working layer extend substantially parallel to each other in a direction forming an angle strictly greater than 10°, preferably from 15° to 50° and more preferably from 15° to 35° with the circumferential direction of the tire.

[0161] We can also consider a shrink-fit armature and a working armature such as those described in particular in US20190152262A1.

[0162] Conventionally, a tire comprises a crown, two sidewalls, and two beads, with each sidewall connecting each bead to the crown. Also conventionally, the crown includes the tread and a crown reinforcement arranged radially within the tread. The tire also includes a carcass reinforcement anchored in each bead and extending radially into each sidewall and axially into the crown, radially internal to the crown reinforcement.

[0163] In embodiments enabling the performance of so-called radial tires, for example as defined by ETRTO, the carcass reinforcement comprises at least one carcass layer, the layer or layers of the carcass comprising wire reinforcement elements, each wire reinforcement element extending substantially along a principal direction forming an angle, in absolute value, of 80° to 90° with the circumferential direction of the tire. Alternatively, the carcass reinforcement may be as described in US20190152262A1.

[0164] In optional but advantageous embodiments, the shrink-fit armature comprises a strip wound helically over several circumferential turns, the average radial thickness Ebm of the strip in the axially central portion of the top is such that Ebm < 0.90 mm, preferably Ebm < 0.80 mm.

[0165] A strip with a relatively low average thickness Ebm, just like a relatively low value of E1m, makes it possible to stiffen the top of the tire and reduce the abrasion rate of the elastomeric material and thus improve mass loss performance in addition to reducing the rolling resistance of the tire.

[0166] The average thickness Ebm will be measured in a manner analogous to the radially average distance E1m. The thickness measurements Eb will be carried out in several Meridional cutting planes are equally distributed around the circumference of the tire, for example, in four meridian cutting planes. The radial thicknesses thus measured are then averaged to obtain the average radial distance Ebm.

[0167] In optional but advantageous embodiments in which the rolling resistance of the tire is reduced by using a low-dissipative shrink-fit reinforcement, the shrink-fit reinforcement comprises several textile shrink-fit wire reinforcement elements embedded in an elastomeric matrix having a dynamic loss tanDMAX25_2 measured according to ASTM D-5992-96 at a temperature of 25°C and a frequency of 10Hz such that tanDMAX25_2 < 0.20, preferably tanDMAX25_2 < 0.17 and more preferably tanDMAX25_2 < 0.15.

[0168] In advantageous and optional variants, the tread includes a radially inner layer arranged radially inside the wearing course and separate from the wearing course.

[0169] The inner radial layer optimizes certain tire performance characteristics, such as rolling resistance, wet grip, and handling. Therefore, the term "distinct from the tread layer" means that the inner radial layer is made of one or more materials different from the sidewall material(s) or the first and second sidewall materials.

[0170] In one of these variants, the inner radial layer is designed to avoid contact with the ground during tire rolling, at least until a regulatory wear threshold is reached. This inner radial layer is referred to as the support layer. However, at specific points—that is, over an axial length less than 10% of the inner radial layer's axial length—the inner radial layer may come into contact with the ground, particularly due to the relative control of industrial processes. Preferably, the inner radial layer is in contact with a crown reinforcement of the tire, for example, as described below.

[0171] In a second configuration of these variants, the radially innermost layer is designed to make contact with the ground during tire rolling before the tire reaches the regulatory wear threshold. This radially innermost layer is referred to as the worn tread layer, as opposed to the new tread layer, which is the outermost radially layer and is designed to make contact with the ground when the tire is new.

[0172] In other variations, the tread does not include an inner radial layer. Thus, the tread layer is in direct contact with the outer layer. of the top reinforcement of the tire, for example as described below.

[0173] In optional and advantageous embodiments, each first and / or second set of at least one block includes at least one additional cutout.

[0174] In some cases, the additional cut has a depth greater than or equal to 50% of the sculpture height.

[0175] These additional, relatively deep cutouts provide the hinge function between axially adjacent portions, ensuring proper flattening of the tire in the contact area and thus reducing tread dissipation.

[0176] In other cases, the additional cut has a depth strictly less than 50% of the sculpture height.

[0177] In advantageous and optional embodiments, the additional cut opens into each of said first and / or second circumferentially successive main lateral cuts.

[0178] In advantageous variants, the additional cutout(s) have a width greater than or equal to 0.4 mm. Preferably, the additional cutout(s) have a width strictly less than 5.0 mm, preferably 2.0 mm.

[0179] In optional but advantageous embodiments, the axially outer end of each first main lateral cutout is arranged on one side of the median plane of the tire and the axially outer end of each second main lateral cutout is arranged on the other side of the median plane of the tire.

[0180] Preferably and optionally, each first and second main lateral cutout has a width ranging from 2.0 to 15.0 mm, preferably from 5.0 to 12.0 mm.

[0181] Preferably and optionally, the incision has a width ranging from 0.4 mm to 2.0 mm, preferably from 0.4 mm to 1.5 mm.

[0182] In advantageous and optional embodiments, each first and / or second set of at least one block comprises a single incision extending at least partially between the first axially external and internal extremities and the second axially external and internal extremities, preferably at least over 80% of the curvilinear length of each first and second set of at least one block.

[0183] Thus, the edge length in the contact area is increased, which improves grip on snow-covered surfaces. The curvilinear length is determined along the line following the general direction of said assembly. Furthermore, by making a single incision, a high rigidity of the assembly is maintained.

[0184] By unique, we mean that there is no other incision made in the whole in which the incision is made.

[0185] In optional but advantageous embodiments allowing for increased storage of snow in the tread, each first and second main lateral cutout extends axially from each outer axial end to each inner axial end for at least 30%, preferably at least 40%, of the axial width of the tread surface.

[0186] Optionally but advantageously, each first and second main lateral cutout extends axially from the outer axial end to the inner axial end along a mean direction forming, with the circumferential direction, a mean angle ranging from 40° to 70°.

[0187] In preferred embodiments, the tire has a direction of rotation, and the circumferentially primary azimuth enters the contact patch with the tire's running surface before the circumferentially secondary azimuth when the tire is mounted on a vehicle moving forward and respecting its direction of rotation. In these embodiments, the tire has a prescribed direction of rotation when mounted on the vehicle. This means that the tire is designed so that, when the vehicle is moving forward, the tire rotates in a predetermined direction, called the direction of rotation. Generally, the tire has markings indicating the direction of rotation. Mounting the tire in such a way that the direction of rotation is not respected can result in suboptimal tire performance.

[0188] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which: Figure 1 is a top view of the tread of a tire according to the invention, Figure 2 is a view, in a meridian cross-section plane, of the tire according to the invention of Figure 1, - Figure 3 is a detailed view of an axially central portion of the apex of the tire in Figure 1, - Figure 4 is a schematic perspective view of an incision in the tire shown in Figures 1 to 3, and - Figures 5, 6 and 7 are schematic perspective views of portions of the incision in figure 4.

[0189] We have represented a coordinate system X, Y, Z corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0190] With reference to Figures 1 and 2, the tire according to the invention is designated by the general reference numeral 10. The tire 10 has a substantially toroidal 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 205 / 55R16. The tire 10 is an all-season tire. The tire 10 is shown in its new condition, i.e., having not yet been driven on. The tire 10 has a direction of rotation R indicating the direction in which, once mounted on the vehicle, the tire 10 must rotate when the vehicle is moving forward.

[0191] The tire 10 includes a crown 12 comprising a tread 14 intended to come into contact with the ground during rolling. The tire 10 also includes a conventional structure, such as, for example, described in applications WO2021250331, WO2022074341 or WO2022069819.

[0192] Referring to Figure 1, the tread 14 comprises a tread surface 16 through which the tread 14 is intended to come into contact with the ground when the tire 10 rolls over the ground. The tread surface 16 is axially delimited by first and second axial edges 18, 20.

[0193] The apex 12 and the tread 14 comprise an axially central portion PO and first and second axially lateral portions P1, P2 arranged axially outside the axially central portion PO on either side of the axially central portion PO with respect to the median plane M of the tire 10. The axially central portion PO has an axial width L0 equal to 50% of the axial width L of the tread surface 16 and is axially centered on the median plane M of the tire 10.

[0194] The tread 14 includes first and second main lateral cutouts 22, 24, a central cutout 26 extending over the entire circumference of the tire 10, additional cutouts 28, 30. The tread 14 also includes first and second sets 32, 34 of blocks 32a, 32b, 32c, 34a, 34b, 34c separated by the additional cutouts 28, 30.

[0195] Each first main lateral cutout 22 extends axially from an axially external end 22A to an axially internal end 22B. The axially external end 22A is arranged on one side of the median plane M. Similarly, each second main lateral cutout 24 extends axially from an axially external end 24A to an axially internal end 24B. The axially external end 24A is arranged on the second side of the median plane M, that is to say on the other side than the side where the axially external end 22A of the first main lateral cutout 22 is arranged.

[0196] Each first main lateral cutout 22 extends circumferentially from a circumferentially first azimuth AZ1 of the inner axial end 22B to a circumferentially second azimuth AZ2 of the outer axial end 22A. The circumferentially first azimuth AZ1 enters the contact area with the running surface of the tire 10 before the circumferentially second azimuth AZ2 when the tire 10 is mounted on a vehicle moving forward and preferentially respecting its direction of rotation R. Similarly, each second main lateral cutout 24 extends circumferentially from a circumferentially first azimuth AZT of the inner axial end 24B to a circumferentially second azimuth AZ2' of the outer axial end 24A.The circumferentially first azimuth AZT enters the contact area with the running surface of the tire 10 before the circumferentially second azimuth AZ2' when the tire 10 is mounted on a vehicle moving forward and preferentially respecting its direction of rotation R.

[0197] Each first and second main lateral cutout 22, 24 extends axially from each axially outer end 22A, 24A to each axially inner end 22B, 24B over at least 30%, preferably at least 40% and here 47% of the axial width L of the rolling surface 16.

[0198] Each first and second main lateral cutout 22, 24 extends axially from the axially outer end 22A, 24A to the axially inner end 22B, 24B along a mean direction forming, with the circumferential direction X, a mean angle ranging from 40° to 70° and here equal to 57°.

[0199] The average pitch Pm between two first and two second circumferentially successive main lateral cutouts 22, 24 is such that Pm < 27 mm, preferably Pm < 26 mm and such that Pm > 23 mm, preferably Pm > 24 mm. Here, Pm = 25 mm.

[0200] Each first and second main lateral cutout 22, 24 has a width ranging from 2.0 to 15.0 mm, preferably from 5.0 to 12.0 mm. Each first and second main lateral cutout 22, 24 has a depth greater than or equal to 75%, and more preferably 90%, of the carving height, and ranging from 5.0 mm to the carving height, preferably from 6.0 mm to the carving height Hs, and more preferably from 6.5 mm to the carving height Hs. The height of The carving height (Hs) is greater than or equal to 6.5 mm, preferably ranging from 6.5 mm to 7.4 mm and more preferably ranging from 6.5 mm to 7.2 mm. Here, the carving height (Hs) and the depth of each first and second main lateral cutout (22, 24) is equal to 7.1 mm.

[0201] Each first set of blocks 32 is circumferentially delimited, at least in part, by a pair of two successive circumferentially circumferential lateral principal cutouts 22. Each first set of blocks 32 comprises a first axially external end 32A and an internal end 32B. Each second set of blocks 34 is circumferentially delimited, at least in part, by a pair of two successive circumferentially circumferential lateral principal cutouts 24. Each second set of blocks 34 comprises a second axially external end 34A and an internal end 34B.

[0202] Each first and second axially inner end 32B, 34B partially delimits the central cutout 26. Each first and second main lateral cutout 22, 24 opens directly into the central cutout 26. The central cutout 26 extends continuously over the entire circumference of the tire 10 in a general direction G forming a substantially constant angle, here substantially zero, with the circumferential direction X of the tire 10.

[0203] The central cutout 26 has a width ranging from 2.0 to 12.0 mm, preferably from 4.0 to 8.0 mm, and here equal to 5.0 mm. The central cutout has a depth greater than or equal to 75%, and more preferably 90%, of the carving height, and ranging from 5.0 mm to the carving height, preferably from 6.0 mm to the carving height, and more preferably from 6.5 mm to the carving height. Here, the carving height Hs and the height of the central cutout 26 are equal to 7.1 mm.

[0204] Each first and second set of blocks 32, 34 comprises several pairs of axially adjacent portions, including an axially inner portion 36, an axially intermediate portion 38, and an axially outer portion 40. The axially intermediate portion 38 is arranged axially between the axially inner portion 36 and the axially outer portion 40. The axially outer portion 40 is arranged axially outside the axially inner portion 36. The axially inner portion 36 is the portion of each first and second set of blocks 32, 34 closest to the median plane M. The axially outer portion 40 is the portion of each first and second set of blocks 32, 34 closest to each first and second axial edge 18, 20 of the tread 14.

[0205] The axially internal portion 36 extends along a different principal direction of the principal direction along which the axially external portion 40 extends. The axially intermediate portion 38 extends along a principal direction different from the principal direction along which the axially internal portion 36 extends and different from the principal direction along which the axially external portion 40 extends. The axially internal portion 36 extends along a principal direction D1 forming with the axial direction Y an angle A1 ranging from 30° to 90°, preferably from 40° to 70° and more preferably from 45° to 65°. The axially intermediate portion 38 extends along a principal direction D2 forming with the axial direction Y an angle A2 ranging from 10° to 50°, preferably from 15° to 45° and more preferably from 20° to 40°.The axially external portion 40 extends along a principal direction D3 forming with the axial direction Y an angle A3 ranging from 0° to 30°, preferably ranging from 0° to 20° and more preferably from 0° to 10°. lci A1>A2>A3 and A1=55°, A2=30° and A3=5°.

[0206] Each first and second set of blocks 32, 34 includes an additional axially internal cutout 28 and an additional axially external cutout 30. Each additional axially internal cutout 28 and external cutout 30 opens into each of the corresponding first circumferentially successive main lateral cutouts 22, 24. Each additional axially internal cutout 28 has a depth strictly less than 50% of the carving height Hs and is here equal to 1.1 mm. Each additional axially external cutout 30 has a depth greater than or equal to 50% of the carving height Hs and is here equal to 6.0 mm. Each additional cutout 28, 30 has a width greater than or equal to 0.4 mm and strictly less than 5.0 mm, preferably 2.0 mm and is here equal to 0.6 mm.

[0207] Figures 4 to 7 show an incision 45 made in a second set of blocks 34. However, for the sake of simplifying the description, the incisions 45 made in each first and second set of blocks 32, 34 will be described simultaneously, the characteristics of the two incisions 45 being deduced mutatis mutandis by symmetry.

[0208] With reference to Figures 1 and 4, each first and second set of blocks 32, 34 includes an incision 45 which is unique here and extends at least in part between the first axially internal end 32B and the first axially external end 32A, preferably at least over 80% of the curvilinear length of each first and second set of blocks 32, 34 and here over 100% of the curvilinear length of each first and second set of blocks 32, 34.

[0209] Each incision 45 extends along a principal direction substantially parallel to the principal direction of each first and second lateral principal cut circumferentially successive 22, 24. Each incision 45 has a width ranging from 0.4 mm to 2.0 mm, preferably from 0.4 mm to 1.5 mm and here equal to 1.5 mm. The portion of the incision 45 contained within each axially intermediate portion 38 and external portion 40 is provided with chamfers.

[0210] With reference to Figures 4 and 5, the axially inner portion 36 of each first and second set of blocks 32, 34 comprises two portions 46, 47 of the incision 45, each having a width that varies with the depth of each portion 46, 47, such that the width of each portion 46, 47 decreases and then increases when moving radially along each portion 46, 47, thus forming a local reduction in width in zones P1, P2. Here, the width of each portion 46, 47 in each zone P1, P2 is 0.2 mm, while the width of each portion 46, 47 outside each zone P1, P2 is 0.4 mm.

[0211] The axially internal portion 36 of each first and second set of blocks 32, 34 also includes a portion 48 of the incision 45 having a general direction D0 undulating along the portion 48 as illustrated in Figure 5.

[0212] Finally, the axially internal portion 36 of each first and second set of blocks 32, 34 includes a portion 49 of the incision 45 having a depth varying along the portion 49 such that the depth of the portion 49 decreases and then increases as one moves along the portion 49 so as to form a local bridging in zones P3, P4 of the portion 49. Here, the depth of the portion 49 in each zone P3, P4 is equal to 3.5 mm while the depth of the portion 49 outside each zone P3, P4 is equal to Hs=7.1 mm.

[0213] With reference to Figures 4 and 6, the axially intermediate portion 38 of each first and second set of blocks 32, 34 comprises two portions 50, 51 of the incision 45, each having a width that varies with the depth of each portion 50, 51, such that the width of each portion 50, 51 decreases and then increases when moving radially along each portion 50, 51, thus forming a local reduction in width in areas P5, P6. Here, the width of each portion 50, 51 in each area P5, P6 is 0.2 mm, while the width of each portion 50, 51 outside each area P5, P6 is 0.4 mm.

[0214] The axially intermediate portion 38 of each first and second set of blocks 32, 34 includes a portion 52 of the incision 45 having a waviness in the radial direction over at least one radial portion of the portion 52. The radial height Hi of the portion 52 over which the waviness extends is greater than or equal to 30%, preferably 40% and more preferably 50% of the depth Pi of the incision 45. Here Hi=5.9 mm and Pi=Hs=7.1 mm.

[0215] With reference to Figures 4 and 7, the axially outer portion 40 of each first and second set of blocks 32, 34 comprises portions 53, 54 of the incision 45 with a width varying with the depth of each portion 53, 54, such that the width of each portion 53, 54 decreases and then increases when moving radially along each portion 53, 54, thus forming a local width reduction in areas P7, P8. Here, the width of each portion 53, 54 in each area P7, P8 is 0.2 mm, while the width of each portion 53, 54 outside each area P7, P8 is 0.4 mm.

[0216] The axially external portion 40 of each first and second set of blocks 32, 34 also includes a portion 55 of the incision 45 having a depth varying along the portion 55 such that the depth of the portion 55 decreases and then increases as one moves along the portion 55 so as to form a local bridging in a P9 zone of the portion 55. Here, the depth of the portion 55 in the P9 zone is equal to 3.3 mm while the depth of the portion 55 outside the P9 zone is equal to 6.5 mm.

[0217] Finally, the axially external portion 40 of each first and second set of blocks 32, 34 also includes portions 56, 57 of the incision 45 exhibiting undulation along the radial direction on at least one radial portion of each portion 56, 57. The undulation of each portion 56, 57 extends over a radial height He1, He2 respectively. The radial height He1 of portion 56 is greater than or equal to 30%, preferably 40%, and more preferably 50% of the depth Pe of the incision 45. Here He2 = 3.6 mm, He1 = 4.8 mm, and Pe = 6.0 mm.

[0218] The sum of the curvilinear lengths li, Ie1, Ie2 of portions 52, 56, and 57 of the incision exhibiting the undulation of each first and second set 32, 34 is greater than or equal to 25%, preferably 30%, of the curvilinear width of each incision 45. Here li = 35 mm, Ie1 = 8 mm, le2 = 10 mm. The curvilinear length Le of each incision 45 is equal to 106 mm, so (li + le1 + le2) / Lc = 50%.

[0219] As illustrated in Figure 1, each first and second axially internal end 32B, 34B is provided with chamfers. Such chamfers are described in more detail in the application filed under number FR2406681 in the name of the applicant.

[0220] With reference to Figure 2, the tread 14 comprises a wearing course 58 and a radially inner layer 59 arranged radially within the wearing course 58 and separate from the wearing course 58. The wearing course 58 comprises an elastomeric material M1 and the radially inner layer 59 comprises an elastomeric material M2. The wearing course 58 carries the tread surface 16 of the tire 10 in new condition.

[0221] The M1 elastomeric material exhibits a complex dynamic shear modulus G*1_60 measured according to ASTM D-5992-96, at a temperature of 60°C and a frequency of 10 Hz under a stress of 0.7 MPa such that G*1_60 > 0.85 MPa, preferably G*1_60 > 0.90 MPa, and more preferably G*1_60 > 0.95 MPa. Also, G*1_60 < 1.50 MPa, preferably G*1_60 < 1.20 MPa, more preferably G*1_60 < 1.15 MPa, and most preferably G*1_60 < 1.10 MPa.

[0222] In a first variant of the elastomeric material M1 in which the mass loss performance is maximized, G*1_60 > 1.00 MPa, preferably G*1_60 > 1.05 MPa and in this case, G*1_60 = 1.07 MPa.

[0223] In a second variant of the invention in which the performance is maximized in rolling resistance, G*1_60 < 1.05 MPa, preferably G*1_60 < 1.00 MPa and in this case G*1_60 = 0.95 MPa.

[0224] In both the first and second variants, the M1 elastomeric material exhibits a complex dynamic shear modulus G*1_-20 measured according to ASTM D-5992-96, at a temperature of -20°C and a frequency of 10 Hz under a stress of 0.7 MPa such that G*1_-20 > 3 MPa, preferably G*1_-20 > 6 MPa and G*1_-20 < 10 MPa, preferably G*1_-20 < 8 MPa. Here, G*1_-20 = 6 MPa.

[0225] The elastomeric material M1 has a glass transition temperature Tg_1 such that Tg_1 < -20°C, preferably Tg_1 < -24°C and more preferably Tg_1 < -26°C, and such that Tg_1 > -30°C, preferably Tg_1 > -28°C. In the first variant, Tg_1 = -27°C. In the second variant, Tg_1 = -26°C.

[0226] The M1 elastomeric material exhibits a dynamic loss tanDMAX23_1 measured according to ASTM D-5992-96 at a temperature of 23°C and a frequency of 10Hz such that tanDMAX23_1 < 0.40 and such that tanDMAX23_1 > 0.30.

[0227] In the first variant of the elastomeric material M1, tanDMAX23_1 > 0.33 and in this case tanDMAX23_1=0.38.

[0228] In the second variant of the elastomeric material M1, tanDMAX23_1 < 0.37, more preferably tanDMAX23_1 < 0.35 and even more preferably tanDMAX23_1 < 0.33 and in this case tanDMAX23_1=0.30.

[0229] In order to obtain these properties, the M1 elastomeric material is based on an elastomeric matrix, one or more reinforcing filler(s), one or more plasticizer(s) and other additives.

[0230] In both the first and second variants, the elastomeric matrix comprises at least one butadiene-styrene copolymer and at least one polybutadiene. The butadiene-styrene copolymer is a Butadiene-styrene copolymer (SBR). The glass transition temperature of the butadiene-styrene copolymer is less than or equal to -60°C, preferably within the range of -110°C to -60°C, preferably from -110°C to -70°C, more preferably from -100°C to -80°C, and even more preferably from -95°C to -80°C, and here equal to -88°C. The glass transition temperature of polybutadiene is within the range of -120°C to -80°C, preferably from -115°C to -100°C, and here equal to -108°C.

[0231] The proportion of butadiene-styrene based copolymer in the M1 elastomeric material is greater than or equal to 40 parts per annum, preferably 50 parts per annum, and more preferably is in the range of 50 to 85 parts per annum.

[0232] In the first variant, the percentage of butadiene-styrene copolymer in the M1 elastomeric material is between 50 and 70 parts per million, and in this case is 60 parts per million. In the second variant, the percentage of butadiene-styrene copolymer in the M1 elastomeric material is between 65 and 85 parts per million, and in this case is 75 parts per million.

[0233] The polybutadiene content in the M1 elastomeric material is in the range of 5 to 50 parts per million (ppm), preferably from 15 to 50 ppm. In the first variant, the polybutadiene content in the M1 elastomeric material is in the range of 30 to 50 ppm, and in this case, equal to 40 ppm. In the second variant, the polybutadiene content in the M1 elastomeric material is in the range of 15 to 35 ppm, and in this case, equal to 25 ppm.

[0234] The M1 elastomeric material is free of isoprenoid elastomer.

[0235] The reinforcing fillers comprise one or more reinforcing inorganic filler(s) including one or more silicas. The percentage of reinforcing inorganic filler(s), and more preferably the percentage of silica, in the M1 elastomeric material is in the range of 80 to 200 parts per cubic centimeter (ppc), preferably 90 to 150 ppc, and preferably 90 to 130 ppc. The volume fraction of reinforcing inorganic filler(s) (%CIR), here of silica, is less than or equal to 20.0%, preferably 19.5%, and greater than or equal to 17.0%, preferably 17.5%.

[0236] In the first variant, the volume fraction of reinforcing inorganic filler(s) %CIR, here of silica(s), is greater than or equal to 18.0%, preferably to 18.5% and more preferably to 19.0% and in this case equal to 19.4%.

[0237] In the second variant, the volume fraction of reinforcing inorganic filler(s) %CIR, here of silica(s), is less than or equal to 19.0%, preferably 18.5% and greater than or equal to 18.0% and in this case equal to 18.1%.

[0238] Whether it's the first or second variant, the plasticizer(s) includes A plasticizing resin having a glass transition temperature above 20°C. The percentage of plasticizing resin is in the range of 25 to 100 parts per cubic meter, preferably 50 to 100 parts per cubic meter, more preferably 55 to 90 parts per cubic meter. The volume fraction of plasticizer(s) %P, here of the plasticizing resin having a glass transition temperature above 20°C, is less than or equal to 32%, preferably 31.5% and more preferably 31.0%, and greater than or equal to 28.0%, preferably 28.5%, more preferably 29.0%, even more preferably 29.5% and very preferably 30.0%.

[0239] In the first variant, the volume fraction of plasticizer(s) %P, here of the plasticizing resin having a glass transition temperature above 20°C, is less than or equal to 30.5% and in this case equal to 30.2%.

[0240] In the second variant, the volume fraction of plasticizer(s) %P, here of the plasticizing resin having a glass transition temperature above 20°C, is greater than or equal to 30.5%, preferably 31.0% and in this case equal to 31.0%.

[0241] Whether it is the first or second variant, the reinforcing fillers include an organic reinforcing filler, in this case carbon black. The carbon black content in the M1 elastomeric material is in the range of 0.1 to 10 parts per million, more preferably from 0.5 to 10 parts per million.

[0242] The elastomeric matrix has a theoretical weighted glass transition temperature Tgt such that Tgt < -91 °C and such that Tgt > -108 °C, preferably Tgt > -105 °C, more preferably Tgt > -100 °C and very preferably Tgt > -98 °C.

[0243] In the first variant, Tgt < -94°C, preferably Tgt < -95°C. In this case, Tgt = [(-88°C x 60) + (-108°C x 40)] / 100 = -96°C.

[0244] In the second variant, Tgt > -96°C, preferably Tgt > -94°C. In this case, Tgt = [(-88°C x 75) + (-108°C x 25)] / 100 = -93°C.

[0245] Table 1 below lists the compositions from which the M1 material of the first and second variants was manufactured using conventional methods known to those skilled in the art. Values ​​are given in pieces.

[0246] [Table 1]

[0247] (1) - Styrene-Butadiene Elastomer described as polymer E on page 34 of WO2018115722, Tg=-88°C; (2) - Buna® CB 22 Polybutadiene marketed by Lanxess, Tg=-108°C; (3) - 160MP Silica from Solvay; (4) - Carbon Black grade 234 according to ASTM D-1765; (5) - Silane selected from "Si69" and "Si75" from Evonik; (6) - "PR-383" Hydrogenated DCPD Resin; (7) - The other additives are classically known to those skilled in the art and include here in particular a protective wax, N-1,3-dimethylbutyl-N-phenylparaphenylenediamine, N-cyclohexyl-benzothiazyl sulphenamide, diphenylguanidine, sulfur, stearic acid, zinc oxide and high oleic sunflower oil.

[0248] With reference to Figures 1 to 3, the apex 12 includes an apex reinforcement 60 extending into the apex 12 in the circumferential direction X. The tire 10 also includes a sealing layer 62 for an inflation gas intended to delimit a closed internal cavity with a mounting support for the tire 10 once the tire 10 is mounted on the mounting support, for example, a rim. The apex reinforcement 60 includes a working reinforcement 64 and a shrink-fit reinforcement 66.

[0249] The working frame 64 comprises two working layers 68 and 70. The radially outer working layer 70 is arranged radially outside the radially inner working layer 68. The shrink-fit frame 66 comprises at least one shrink-fit layer and here includes a shrink-fit layer 72.

[0250] The top reinforcement 60 is arranged radially inside the tread 14. The shrinkage reinforcement 66, here the shrinkage layer 72, is arranged radially outside the working reinforcement 64 and radially inside the tread 14. The shrinkage reinforcement 66 is therefore radially interposed between the working reinforcement 64 and the tread 14. The shrinkage layer 72 is therefore the outermost radially outermost layer of the top reinforcement 60.

[0251] The tire 10 comprises two sidewalls 74 extending radially inwards from the apex 12. The tire 10 further comprises two beads 76 radially inwards from the sidewalls 74. Each sidewall 74 connects each bead 76 to the apex 12.

[0252] The tire 10 comprises a carcass frame 78 anchored in each bead 76, in this case wound around two beads 80. The carcass frame 78 extends radially in each sidewall 74 and axially in the top 12 radially internally to the top reinforcement 60. The top reinforcement 60 is arranged radially between the tread 14 and the carcass reinforcement 78. The carcass reinforcement 78 comprises at least one carcass layer and here comprises a single carcass layer 82.

[0253] Referring to Figure 3, each working layer 68, 70, shrink-fit layer 72, and frame layer 82 comprises a polymer matrix, in this case an elastomeric matrix, in which one or more wire reinforcement elements of the corresponding layer are embedded. Thus, each working layer 68, 70 comprises working wire reinforcement elements 680, 700 respectively, the shrink-fit layer 72 comprises shrink-fit wire reinforcement elements 720, and the frame layer 82 comprises frame wire reinforcement elements 820. The angles of the wire reinforcement elements and the materials of the wire reinforcement elements are described, for example, in WO2021250331. Regarding the shrink-fit layer 72, a shrink-fit layer as described in WO2022148921 is preferred.

[0254] In particular, the 720 textile wire reinforcement elements are embedded in an elastomeric matrix having a dynamic loss tanDMAX25_2 measured according to ASTM D-5992-96 at a temperature of 23°C and a frequency of 10Hz such that tanDMAX25_2 < 0.20, preferably tanDMAX25_2 < 0.17 and more preferably tanDMAX25_2 < 0.15 and here tanDMAX25_2=0.15.

[0255] The interfaces between two adjacent layers are represented by dashed lines. In Figure 3, the following are shown: - the surface 100 passing through the innermost radial point of the deepest cut in the axially central portion PO of the tread 14 and substantially parallel to the tread surface, here passing through the innermost point of the cuts 22, 24, 26 and substantially parallel to the tread surface 16, - the radially outer surface 102 passing through the radially outermost points of the most radially outer wire reinforcement elements 720 among the wire reinforcement elements 720 of the radially outermost layer 72 arranged vertically above the axially central portion PO of the tread 14, - the radially inner surface 104 along the interface between the shrink-fit armature 66 and the working armature 64, - the radially external surface 106 along the interface between the shrink-fit reinforcement 66 and the tread 14.

[0256] In the axially central portion PO of the tread 14, the distance The radial mean E1m of the distances E1 between surface 100 and the radially outer surface 102 is such that E1m < 2.30 mm, preferably E1m < 2.20 mm, and more preferably E1m < 2.00 mm. Furthermore, E1m > 0.50 mm, preferably E1m > 1.00 mm, and more preferably E1m > 1.80 mm. In this case, E1 = 1.80 mm.

[0257] The shrink-fit reinforcement 66 comprises a strip wound helically over several circumferential turns. In the described embodiment, the radial thickness of the strip Eb in the axially central portion PO between the radially inner surface 104 and the radially outer surface 106 is equal to the radial thickness of the shrink-fit layer 72. The average radial thickness Ebm of the strip is such that Ebm < 0.90 mm, preferably Ebm < 0.80 mm. Here, Ebm = 0.74 mm.

[0258] COMPARATIVE TESTS

[0259] We compared the tires 101, 102 according respectively to the first and second variants of the invention described above with control tires T0, T11, T12, T2 and T3 whose characteristics are gathered in Table 2 below.

[0260] In all the tests described below, the results are given using the reference tire T0 as the baseline of 100. The reference tire T0 is a tire sold as a replacement under the commercial name Cross Climate 2. A score above 100 indicates an improvement in the performance compared to the T0 tire, while a score below 100 indicates a deterioration in the performance compared to the T0 tire.

[0261] The tested tire was driven, and the wear on the front tires of the front-wheel-drive vehicle was recorded over approximately 15,000 km. To shorten the test, the wear was extrapolated until one section of the tread reached the maximum wear indicated by the regulatory wear indicator. The average mileage was then calculated for both front tires. This allowed us to determine the maximum mileage reached by each tire, which reflects its lifespan.

[0262] The mass loss is determined during the previous test by weighing the tire at the beginning and end of the ride. The mass loss (in grams) is calculated per kilometer traveled.

[0263] We evaluated the wet grip performance by taking into account four wet tire performance factors: straight-line braking distance between 80 km / h and 20 km / h, straight-line hydroplaning, lateral hydroplaning, and wet track lap time.

[0264] The traction performance on snow-covered surfaces was evaluated in accordance with the ASTM F1805-20 standard mentioned by UNECE R117.

[0265] The rolling resistance test was conducted according to ISO 28580:2018. For a tested tire, the result is the rolling resistance coefficient, which represents the ratio of the tire's resistance force to the vehicle's forward motion (due to hysteresis) divided by the load carried. A reduction in rolling resistance corresponds to an improvement in performance.

[0266] [Table 2] characteristics of the first group of elastomeric material characteristics and the characteristics of the second group of tread characteristics with regard to tire longevity. In particular, the performance of T11 and T12 tires (which include the characteristics of the first group) and the performance of the T2 tire (which includes the characteristics of the second group) are not additive. Moreover, the results of the lifespan performance test show a synergy between the characteristics of the first group and those of the second group making it possible to obtain a tire according to the invention exhibiting unexpected performance in lifespan.

[0268] The invention is not limited to the embodiment described above.

[0269] Indeed, it will be possible to design a tire in which each first and / or second set of at least one block includes axially internal and external portions without necessarily the presence of an axially intermediate portion.

[0270] Regardless of the characteristics described in this application, consideration may be given to the operation of a tire comprising a tread including a tread layer carrying at least part of a tread surface, the tread layer comprising an elastomeric material based on: - of an elastomeric matrix comprising at least one elastomer, - of at least one coupling agent comprising one or more mercaptosilane(s), - of at least one reinforcing charge comprising one or more reinforcing inorganic charge(s), the top comprising a top reinforcement comprising a rigid shrink-fit reinforcement comprising one or more wire reinforcement element(s) of textile shrink-fitting wound helix circumferentially around an axis of the tire.

[0271] This tire, thanks to its elastomeric material, improves the balance between grip performance on wet and snowy surfaces. However, this elastomeric material leads to a degradation in performance due to weight loss, which this tire compensates for through the introduction of a rigid reinforcement ring. This ring reinforcement stiffens the crown and thus reduces tread wear, as explained in this application. Furthermore, the rigid reinforcement ring improves the tire's handling, particularly by increasing its drift stiffness.

[0272] The elastomeric materials providing the advantages described above can, for example, be deduced from those described in W02021 / 005295 or in WO2019069019, in particular composition CP2. Preferably, the volume fraction of reinforcing inorganic filler(s) should be greater than or equal to 20.5%, preferably 21.0%, and more preferably 21.5%.

[0273] To achieve high stiffness, the textile wire reinforcement elements are high-modulus textile wire reinforcement elements. For this purpose, one can, for example, use textile wire reinforcement elements described in W02021 / 074511 or a textile wire reinforcement element comprising a multifilament strand made of polyamide monofilament yarn. An aliphatic strand, here made of nylon with a count of 140 tex, and a multifilament strand consisting of a spun strand of aromatic polyamide monofilaments, here aramid with a count of 167 tex, these two multifilament strands being individually helically wound at 290 turns per meter in one direction and then helically wound together at 290 turns per meter in the opposite direction. These two multifilament strands are then helically wound around each other. These high-modulus textile yarn reinforcement elements are, for example, arranged at a density greater than or equal to 70 threads per decimeter, preferably 90 threads per decimeter within the reinforcement layer.

[0274] The tread pattern of such a tire may be one of those described in W02021 / 019174 or that described in this application. In the latter cases, care shall be taken to favor incisions comprising portions with varying depths along said portion, such that the depth of said portion decreases and then increases as one moves along said portion, thereby forming a local bridge. Optimally, and in order to increase the rigidity of the tire tread pattern, such portions shall be incorporated into each axially inner, axially intermediate, and axially outer portion as described in this application.

Claims

- 45 - DEMANDS 1. Tire (10) comprising a vertex (12) comprising a tread (14) comprising first and second lateral main cutouts (22, 24), each first and second lateral main cutout (22, 24) extending: - axially from an axially external end (22A, 24A) of each first and second main lateral cutout (22, 24) to an axially internal end (22B, 24B) of each first and second main lateral cutout (22, 24), - circumferentially from a circumferentially first azimuth (AZ1, AZT) of the inner axial end (22B, 24B) to a circumferentially second azimuth (AZ2, AZ2') of the outer axial end (22A, 24A), the circumferentially first azimuth (AZ1, AZT) entering the contact area with the running surface of the tire before the circumferentially second azimuth (AZ2, AZ2') when the tire (10) is mounted on a vehicle moving forward, the tread (14) comprising first and second sets (32, 34) of at least one block (32a, 32b, 32c, 34a, 34b, 34c), each first and second set (32, 34) of at least one block being circumferentially delimited at least in part by a pair respectively of two first and two second main lateral cuts (22, 24) circumferentially successive, each first and second set (32,34) of at least one block comprising respectively a first axially inner end (32B) and an outer end (32A) and a second axially inner end (34B) and an outer end (34A), characterized in that the tread (14) comprises a wearing layer (58) carrying at least a portion of a tread surface (16), the wearing layer (58) comprising an elastomeric material (M1) having a complex dynamic shear modulus G*1_60 measured according to ASTM D-5992-96, at a temperature of 60°C and a frequency of 10 Hz under a stress of 0.7 MPa such that G*1_60 > 0.85 MPa, the elastomeric material (M1) being based on an elastomeric matrix having a theoretical weighted glass transition temperature Tgt < -91°C, the theoretical weighted glass transition temperature Tgt being defined as the average of the transition temperature(s) vitreous of the elastomer(s) of the elastomeric matrix weighted by their rate,expressed in pc, in the elastomeric matrix, - 46 - the elastomeric material (M1) being based on at least one reinforcing filler comprising one or more reinforcing inorganic filler(s), the volume fraction of reinforcing inorganic filler(s) being less than or equal to 20.0%, the tread (14) having a tread height (Hs) greater than or equal to 6.5 mm, each first and / or second assembly (32, 34) comprising an incision (45) extending at least in part respectively between the first axially inner (32B) and outer (32A) ends and / or between the second axially inner (34B) and outer (34A) ends, the incision (45) comprising at least a portion (52, 56, 57) having a waviness along the radial direction (X).

2. Pneumatic (10) according to the preceding claim, wherein the elastomeric material (M1) is based on one or more plasticizer(s), the volume fraction of plasticizer(s) being less than or equal to 32.0%.

3. Pneumatic (10) according to any one of the preceding claims, wherein the average pitch Pm between two first and / or two second circumferentially successive main lateral cutouts (22, 24) is such that Pm < 27 mm, preferably Pm < 26 mm.

4. Pneumatic (10) according to any one of the preceding claims, wherein each first and / or second assembly (32, 34) of at least one block comprises: - an axially internal portion (36), - an axially external portion (40) arranged axially outside the axially internal portion (36), the axially external portion (40) of each first and / or second set (32, 34) of at least one block includes at least one portion (56, 57) of the incision (45) exhibiting a waviness along the radial direction (X) on at least one radial portion of said portion (56, 57) of the incision (45).

5. Pneumatic (10) according to the preceding claim, wherein the axially inner portion (36) extends along a principal direction (D1) different from the principal direction (D3) along which the axially outer portion (40) extends, preferably the axially inner portion (36) extends along a principal direction (D1) forming with the axial direction (Y) an angle (A1) strictly greater than the angle (A3) formed with the axial direction (Y) by a principal direction (D3) along which the axially outer portion (40) extends.

6. Pneumatic (10) according to claim 4 or 5, wherein each first and / or second assembly (32, 34) of at least one block comprises an axially - 47 - intermediate (38) arranged axially between the axially inner portion (36) and the axially outer portion (40), the axially intermediate portion (38) of each first and / or second set (32, 34) of at least one block comprises at least one portion (52) of the incision (45) exhibiting a waviness along the radial direction (X) on at least one radial portion of said portion (52) of the incision (45).

7. Pneumatic (10) according to the preceding claim, wherein the axially intermediate portion (38) extends along a principal direction (D2) different from the principal direction (D1) along which the axially inner portion (36) extends and different from the principal direction (D3) along which the axially outer portion (40) extends, preferably the axially intermediate portion (38) extends along a principal direction (D2) forming with the axial direction (Y) an angle (A2) strictly greater than the angle (A3) formed with the axial direction (Y) by a principal direction (D3) along which the axially outer portion (40) extends and strictly less than the angle (A1) formed with the axial direction (Y) by a principal direction (D1) along which the axially inner portion (36) extends.

8. Pneumatic (10) according to any one of claims 4 to 7, wherein the axially inner portion (36) and / or the axially intermediate portion (38) and / or the axially outer portion (40) of each first and / or second assembly (32, 34) of at least one block comprises at least one portion (46, 47, 48, 49, 50, 51, 53, 54, 55) of the incision (45) having: - a width varying with the depth of said portion (46, 47, 50, 51, 53, 54) such that the width of said portion (46, 47, 50, 51, 53, 54) decreases and then increases when moving radially along said portion (46, 47, 50, 51, 53, 54) so ​​as to form a local width reduction and / or - a general direction undulating along said portion (48), and / or - a depth varying along said portion (49, 55) so that the depth of said portion (49, 55) decreases and then increases when moving along said portion (49, 55) so as to form a local bridge.

9. A pneumatic device (10) according to any one of the preceding claims, wherein the elastomeric material (M1) has a glass transition temperature Tg_1 such that Tg_1 < -20°C, preferably Tg_1 < -24°C and more preferably Tg_1 < -26°C.

10. A pneumatic device (10) according to any one of the preceding claims, wherein the elastomeric material (M1) has a glass transition temperature Tg_1 such that Tg_1 > -30°C, preferably Tg_1 > -28°C.

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