RUBBER COMPOSITION

Description

[0001] The field of the present invention is that of rubber compositions reinforced by a reinforcing filler, in particular used in the manufacture of pneumatic or non-pneumatic tires for vehicles, more particularly used for the manufacture of treads.

[0002] A tread for a pneumatic or non-pneumatic tire must, in a known way, meet a large number of often conflicting technical requirements, including low rolling resistance, high wear resistance, and high grip on wet surfaces.

[0003] This compromise of properties, particularly in terms of rolling resistance and wear resistance, has been improved in recent years on low-energy "green" tires, primarily intended for passenger vehicles. This improvement is largely due to the use of new, low-hysteresis rubber compounds as treads. These compounds are characterized by being reinforced primarily with specific inorganic fillers, known as reinforcing agents, notably highly dispersible silicas (HDS), which can rival conventional tire-grade carbon blacks in terms of reinforcing power. However, the high silica content in these rubber compounds is not optimal for wet grip performance; this grip is lower than that of compounds with lower silica content.

[0004] It is known that the grip of a tire on a wet surface is achieved by increasing the contact area of ​​the tread on the road surface, notably by using a deformable material for the tread, in this case a deformable rubber compound. One way to make a rubber compound more deformable is to add a large quantity of plasticizers. However, a highly deformable rubber compound has the disadvantage of exhibiting significant hysteresis. Improving rolling resistance requires reducing hysteresis losses.

[0005] Thus, the rubber compound of the tread must satisfy two conflicting requirements: maximum hysteresis potential to meet the grip requirement and the lowest possible hysteresis to meet the rolling resistance requirement. JP H08 27313 concerns a rubber compound for a tread used to produce a tire with a good balance between wet grip and low rolling resistance without compromising the tire's wear resistance.

[0006] One aim of the present invention is therefore to propose new rubber compositions, in particular for treads, which remedy in particular the aforementioned disadvantages; exhibiting in particular improved hysteresis properties while maintaining, or even improving, their wet grip performance.

[0007] This objective is achieved because the Applicant has recently discovered, surprisingly, that a specific combination of diene elastomers with a defined glass transition temperature differential overcomes the aforementioned drawbacks. Indeed, when a rubber compound comprises at least one unfunctionalized diene elastomer E1 with a glass transition temperature TgE1 greater than or equal to -50°C, this elastomer E1 being present at a concentration ranging from 50% to 70%, and at least one second functionalized diene elastomer E2 with a glass transition temperature TgE2 satisfying the mathematical relationship TgE2 ≤ TgE1 - 23°C, then this compound exhibits excellent rolling resistance while maintaining good wet grip.

[0008] Thus, a first object of the present invention relates to a rubber composition based on at least one first non-functionalized diene elastomer E1 having a glass transition temperature TgE1, a second functionalized diene elastomer E2 having a glass transition temperature TgE2, a reinforcing filler capable of interacting with the functionalized diene elastomer E2 and a crosslinking system, in which: the glass transition temperature TgE1 is greater than or equal to -50°C, the glass transition temperature TgE2 satisfies the mathematical relationship TgE2 ≤ TgE1 - 23°C, and the proportion of the unfunctionalized diene elastomer E1 is within a range of 50 pce to 70 pce.

[0009] Advantageously, the glass transition temperature TgE2 can satisfy the mathematical relationship TgE2 ≤ TgE1 - 28°C, more preferably TgE2 ≤ TgE1 - 30°C.

[0010] Advantageously, the glass transition temperature TgE2 can satisfy the mathematical relationship TgE2 ≥ TgE1 - 65°C, more preferably TgE2 ≥ TgE1 - 50°C, more preferably still TgE2 ≥ TgE1 - 45°C.

[0011] Advantageously, the glass transition temperature TgE1 can be in a range from -50°C to 0°C, more preferably from -40°C to 0°C, more preferably from -30°C to 0°C.

[0012] Advantageously, the glass transition temperature TgE2 can be in the range of -110°C to -23°C, preferably from -100°C to -28°C, more preferably from -95°C to -30°C.

[0013] Advantageously, the proportion of the unfunctionalized E1 diene elastomer can be in the range of 55% to 70%, more preferably 55% to 65%.

[0014] Advantageously, the reinforcing load ratio can be in the range of 20 to 100 pc, preferably in the range of 30 to 90 pc, more preferably in the range of 40 to 90 pc.

[0015] Advantageously, the reinforcing filler may predominantly comprise at least one inorganic reinforcing filler, or more preferably, may predominantly comprise at least one silica. Preferably, the inorganic reinforcing filler, preferably silica, represents more than 50% by mass, and preferably more than 55% by mass, of the total mass of the reinforcing filler in the rubber composition. More preferably still, the reinforcing filler may predominantly comprise at least one silica and may also comprise at least one carbon black; the carbon black being a minor component. Preferably, the rubber composition may further comprise a coupling agent for the reinforcing filler with the diene elastomer. Preferably, this coupling agent may be a polysulfide organosilane.

[0016] Advantageously, the unfunctionalized diene elastomer E1 can be selected from the group consisting of synthetic polyisoprenes, polybutadienes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isoprene-styrene copolymers, and butadiene-styrene-isoprene copolymers. Preferably, the unfunctionalized diene elastomer E1 is selected from polybutadienes and styrene-butadiene copolymers. Even more preferably, the unfunctionalized diene elastomer E1 is a styrene-butadiene copolymer.

[0017] Advantageously, the functionalized E2 diene elastomer can be selected from the group consisting of natural rubber, synthetic polyisoprenes, polybutadienes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isobutene-isoprene copolymers, isoprene-styrene copolymers, and butadiene-styrene-isoprene copolymers. Preferably, the functionalized E2 diene elastomer is selected from polybutadienes and styrene-butadiene copolymers. Even more preferably, the functionalized E2 diene elastomer is a styrene-butadiene copolymer.

[0018] Advantageously, the functionalized E2 diene elastomer may comprise at least one chemical function capable of interacting with the reinforcing charge, the chemical function comprising at least one heteroatom selected from the group consisting of nitrogen, sulfur, oxygen, phosphorus, tin and silicon.

[0019] Advantageously, the reinforcing charge comprises predominantly a reinforcing inorganic charge, preferably a silica, and the functionalized E2 diene elastomer may comprise at least one chemical function capable of interacting with the reinforcing inorganic charge, the chemical function comprising at least one heteroatom selected from the group consisting of nitrogen, sulfur, oxygen and phosphorus.

[0020] Advantageously, the chemical function capable of interacting with the reinforcing charge can be a polar function comprising at least one oxygen atom.

[0021] Advantageously, the polar function can be chosen from the group consisting of silanol, alkoxysilanes with or without an amine group, epoxide, ethers, esters, carboxylic acids and hydroxyl.

[0022] Advantageously, the functionalized E2 diene elastomer may include a polar function which is a silanol. Preferably, the silanol may be located at the end or in the middle of the main chain of the functionalized diene elastomer, more preferably the silanol being located at the end of the main chain of the functionalized diene elastomer.

[0023] Advantageously, the functionalized E2 diene elastomer may include a polar function, which is an alkoxysilane with or without an amine group. Preferably, the alkoxysilane, with or without an amine group, may be located at the end or in the middle of the main chain of the functionalized E2 diene elastomer; more preferably, the alkoxysilane group, with or without the amine group, is located in the middle of the main chain of the functionalized E2 diene elastomer. Preferably, the amine group may be a tertiary amine.

[0024] Advantageously, the proportion of the E2 diene elastomer functionalized in the composition of the invention is in the range of 30 pc to 50 pc, preferably from 30 pc to 45 pc, more preferably from 35 pc to 45 pc.

[0025] Advantageously, the proportion of unfunctionalized diene elastomer E1 in the composition of the invention is in the range of 50% to 70%, and the proportion of functionalized diene elastomer E2 in the composition of the invention is in the range of 30% to 50%. Advantageously, the proportion of unfunctionalized diene elastomer E1 in the composition of the invention is in the range of 55% to 70%, and the proportion of functionalized diene elastomer E2 in the composition of the invention is in the range of 30% to 45%.

[0026] Advantageously, the rubber composition as defined above further includes at least one plasticizer.

[0027] Advantageously, the rubber composition as defined above and its preferred embodiments can be obtained by a manufacturing process which includes the following steps: introduce into an internal mixer the unfunctionalized diene elastomer E1 having the aforementioned glass transition temperature TgE1 and, where applicable, other ingredients such as a plasticizer, and conduct thermomechanical work up to a maximum temperature of 200°C to obtain a first mastermix; introduce into an internal mixer the functionalized diene elastomer E2 having the aforementioned glass transition temperature TgE2, the reinforcing filler and, where applicable, the coupling agent and other ingredients such as a plasticizer, and conduct thermomechanical work up to a maximum temperature of 200°C to obtain a second mastermix; introduce into an internal mixer the first and second mastermixes obtained in the previous steps and conduct thermomechanical work up to a maximum temperature of 180°C to obtain a mixture;Retrieve the mixture from the previous step and cool it to a temperature of 110°C or lower; incorporate the crosslinking system into the cooled mixture and knead to a maximum temperature below 110°C, preferably below 80°C, and recover the rubber composition.

[0028] Another object of the present invention relates to a tread comprising at least one composition defined above.

[0029] Another object of the present invention relates to a tire comprising at least one composition as defined above or comprising at least one tread as defined above.

[0030] A first object of the present invention relates to a rubber composition based on at least a first non-functionalized diene elastomer E1 having a glass transition temperature TgE1, a second functionalized diene elastomer E2 having a glass transition temperature TgE2, a reinforcing filler capable of interacting with the functionalized diene elastomer E2 and a crosslinking system, wherein: the glass transition temperature TgE1 is greater than or equal to -50°C, the glass transition temperature TgE2 satisfies the mathematical relationship TgE2 ≤ TgE1 - 23°C, and the proportion of the non-functionalized diene elastomer E1 is within a range of 50 pce to 70 pce.

[0031] By "rubber composition based on", we mean a composition comprising the mixture and / or the in situ reaction product of the different constituents used, some of these constituents being able to react and / or being intended to react with each other, at least partially, during the different phases of manufacturing the composition; the composition can thus be in a totally or partially crosslinked state or in a non-crosslinked state.

[0032] The expression "part by weight per hundred parts by weight of elastomer" (or pce) is to be understood in the context of the present invention as the part, by mass per hundred parts by mass of elastomer of the composition.

[0033] In this document, unless expressly stated otherwise, all percentages (%) shown are percentages (%) by mass.

[0034] On the other hand, any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​going from more than a to less than b (that is, bounds a and b excluded) while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​going from a to b (that is, including the strict bounds a and b).

[0035] When referring to a "major" compound, for the purposes of this invention, it is understood that this compound is the major compound among the compounds of the same type in the rubber composition; that is, it is the one that represents the greatest quantity by mass among the compounds of the same type. Thus, for example, a major elastomer is the elastomer representing the greatest mass relative to the total mass of the elastomers in the composition. Similarly, a major filler is the one representing the greatest mass among the fillers in the composition. By way of example, in a system comprising a single elastomer, this elastomer is the major compound for the purposes of this invention; and in a system comprising two elastomers, the major elastomer represents more than half the mass of the elastomers.Conversely, a "minor" compound is one that does not represent the largest mass fraction among compounds of the same type. Preferably, "major" means present at more than 50%, preferably more than 60%, 70%, 80%, 90%, and most preferably, the "major" compound represents 100%.

[0036] The carbon-containing compounds mentioned in the description may be of fossil origin or bio-based. In the latter case, they may be partially or entirely derived from biomass or obtained from renewable raw materials derived from biomass. This includes, in particular, polymers, plasticizers, fillers, etc.

[0037] By "diene elastomer or indistinctly rubber", whether natural or synthetic, should be understood in a known way an elastomer consisting at least in part (i.e., a homopolymer or a copolymer) of diene monomer units (monomers bearing two carbon-carbon double bonds, conjugated or not).

[0038] By "elastomeric matrix" we mean the set of elastomers forming the rubber composition of the invention.

[0039] Diene elastomers can be classified into two categories: "essentially unsaturated" or "essentially saturated". Generally, "essentially unsaturated" refers to a diene elastomer derived at least in part from conjugated diene monomers, with a proportion of diene motifs or units (conjugated dienes) greater than 15% (mole percent); thus, diene elastomers such as butyl rubbers or EPDM-type diene-alpha-olefin copolymers do not fall under the previous definition and can be described as "essentially saturated" diene elastomers (low or very low proportion of diene motifs, always less than 15% by mole).

[0040] More specifically, a diene elastomer capable of being used in compositions according to the invention is understood to mean: any homopolymer of a diene monomer, conjugated or not, having from 4 to 18 carbon atoms; any copolymer of a diene, conjugated or not, having from 4 to 18 carbon atoms and at least one other monomer.

[0041] The other monomer can be an olefin or a diene, conjugated or not.

[0042] Suitable conjugated dienes are those with 4 to 12 carbon atoms, in particular 1,3-dienes, such as 1,3-butadiene and isoprene.

[0043] Suitable as unconjugated dienes are unconjugated dienes having 6 to 12 carbon atoms, such as 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene.

[0044] Suitable olefins include vinylaromatic compounds with 8 to 20 carbon atoms and aliphatic α-monoolefins with 3 to 12 carbon atoms.

[0045] Examples of suitable vinylaromatic compounds include styrene, ortho-, meta-, para-methylstyrene, the commercial mixture "vinyl-toluene", and para-tert-butylstyrene.

[0046] More specifically, diene elastomer is: any homopolymer of a conjugated diene monomer, in particular any homopolymer obtained by polymerization of a conjugated diene monomer having from 4 to 12 carbon atoms; any copolymer obtained by copolymerization of one or more dienes conjugated with each other or with one or more vinylaromatic compounds having from 8 to 20 carbon atoms; a copolymer of isobutene and isoprene (butyl rubber), as well as halogenated versions, in particular chlorinated or brominated, of this type of copolymer.

[0047] The rubber composition according to the invention comprises at least a first unfunctionalized diene elastomer E1 having a glass transition temperature TgE1 greater than or equal to -50°C and at least a second functionalized diene elastomer E2 having a glass transition temperature TgE2, the glass transition temperature TgE2 satisfying the mathematical relation TgE2 ≤ TgE1 - 23°C; the unfunctionalized diene elastomer E1 being present at a concentration in the range of 50 parts per million to 70 parts per million. Surprisingly, this combination yields a rubber composition that exhibits excellent hysteresis properties (and therefore low rolling resistance) while also possessing remarkable wet grip properties.

[0048] The glass transition temperatures TgE1 and TgE2 are measured according to ASTM D3418:2008.

[0049] For the purposes of this invention, "a functionalized diene elastomer" means a diene elastomer, whether natural or synthetic, bearing a chemical function capable of interacting with a reinforcing charge. The chemical function capable of interacting with the reinforcing charge may be, in particular, a heteroatom or a group of atoms comprising at least one heteroatom selected from nitrogen, sulfur, oxygen, phosphorus, tin, and silicon.

[0050] For the purposes of this invention, "non-functionalized diene elastomer" means a diene elastomer, whether natural or synthetic, that does not carry a chemical function capable of interacting with a reinforcing charge. Preferably, the non-functionalized diene elastomer may consist essentially of carbon and hydrogen atoms. It may not contain heteroatoms, or may contain only in quantities that are impurities resulting from its synthesis process. E1 diene elastomer

[0051] The diene elastomer E1 is non-functionalized and has a glass transition temperature TgE1 greater than or equal to -50°C. More preferably, the glass transition temperature TgE1 is in the range of -50°C to 0°C, more preferably -40°C to 0°C, more preferably -30°C to 0°C.

[0052] The non-functionalized E1 diene elastomer can be any of the aforementioned diene elastomers provided that its glass transition temperature TgE1 is greater than or equal to -50°C.

[0053] Preferably, the unfunctionalized diene elastomer E1 is selected from the group consisting of synthetic polyisoprenes, polybutadienes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isoprene-styrene copolymers, and butadiene-styrene-isoprene copolymers. Preferably, the unfunctionalized diene elastomer E1 is selected from polybutadienes and styrene-butadiene copolymers. Advantageously, the unfunctionalized diene elastomer E1 is a styrene-butadiene copolymer.

[0054] Suitable as non-functionalized E1 diene elastomer in particular are butadiene and styrene copolymers having a Tg within a range of -50°C to 0°C, a styrene content within a range of 1% to 30% by weight relative to the copolymer weight, a butadiene-1,2 vinyl content within a range of 14% to 93% by weight relative to the copolymer weight, a butadiene-1,4-cis content within a range of 2% to 22% by weight relative to the copolymer weight and a butadiene-1,4-trans content within a range of 3% to 33% by weight relative to the copolymer weight.

[0055] Suitable as non-functionalized E1 diene elastomer in particular are polybutadienes having a Tg within a range of -50°C to 0°C, a butadiene-1,2 vinyl content within a range of 52% to 95% by weight relative to the copolymer weight, a butadiene-1,4-cis content within a range of 0% to 38% by weight relative to the copolymer weight and a butadiene-1,4-trans content within a range of 0% to 48% by weight relative to the copolymer weight.

[0056] The proportion of the non-functionalized E1 diene elastomer in the composition of the invention is in the range of 50 parts to 70 parts, preferably 55 parts to 70 parts, more preferably 55 parts to 65 parts.

[0057] These non-functional diene elastomers are commercially available from suppliers such as Nippon Zeon, JSR, Bayer, etc. E2 diene elastomer

[0058] As seen previously, the rubber composition includes at least one diene elastomer E2, this elastomer being functionalized and having a glass transition temperature TgE2 satisfying the mathematical relation TgE2 ≤ TgE1 - 23°C.

[0059] Preferably, the glass transition temperature TgE2 of the functionalized E2 diene elastomer satisfies the mathematical relation TgE2 ≤ TgE1 - 28°C, more preferably TgE2 ≤ TgE1 - 30°C.

[0060] Advantageously, the glass transition temperature TgE2 of the functionalized E2 diene elastomer satisfies the mathematical relation TgE2 ≥ TgE1 - 65°C, more preferably TgE2 ≥ TgE1 - 50°C, more preferably still TgE2 ≥ TgE1 - 45°C.

[0061] Even more advantageously, the glass transition temperature TgE2 of the functionalized E2 diene elastomer is in the range of -110°C to -23°C, preferably from -100°C to -28°C, more preferably from -95°C to -30°C.

[0062] The functionalized E2 diene elastomer can be any of the aforementioned diene elastomers provided that it is functionalized and that its glass transition temperature satisfies the aforementioned mathematical relationship.

[0063] Preferably, the functionalized E2 diene elastomer may be selected from the group consisting of natural rubber, synthetic polyisoprenes, polybutadienes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isobutene-isoprene copolymers, isoprene-styrene copolymers, and butadiene-styrene-isoprene copolymers. Preferably, the functionalized E2 diene elastomer is selected from polybutadienes and styrene-butadiene copolymers. Even more preferably, the functionalized E2 diene elastomer is a styrene-butadiene copolymer.

[0064] Suitable as functionalized E2 diene elastomers in particular are butadiene and styrene copolymers having a Tg within a range of -100°C to -28°C, a styrene content within a range of 1% to 30% by weight relative to the copolymer weight, a 1,2-vinyl butadiene content within a range of 0% to 74% by weight relative to the copolymer weight, a 1,4-cis butadiene content within a range of 10% to 40% by weight relative to the copolymer weight and a 1,4-trans butadiene content within a range of 15% to 59% by weight relative to the copolymer weight.

[0065] Suitable as functionalized E2 diene elastomers in particular are polybutadienes having a Tg within a range of -110°C to -23°C, a -1,2 vinyl butadiene content within a range of 0% to 82% by weight relative to the copolymer weight, a 1,4-cis butadiene content within a range of 0% to 100% by weight relative to the copolymer weight and a 1,4-trans butadiene content within a range of 0% to 100% by weight relative to the copolymer weight.

[0066] The functionalization of the E2 diene elastomer is known. It can be done during the synthesis of the diene elastomer or after its synthesis by grafting chemical functions onto the monomers of the diene elastomer.

[0067] The functionalized E2 diene elastomer comprises at least one chemical function capable of interacting with the reinforcing charge. This chemical function comprises at least one heteroatom selected from the group consisting of nitrogen, sulfur, oxygen, phosphorus, tin, and silicon. Examples of such functions include primary, secondary, or tertiary amines, whether cyclic or not, isocyanates, imines, cyanoacrylates, thiols, carboxylates, epoxides, and primary, secondary, or tertiary phosphines. This interaction of the functionalized E2 diene elastomer with the reinforcing charge can be established, for example, through covalent bonds, hydrogen bonds, ionic bonds, and / or electrostatic bonds between the function(s) of the diene elastomer and the chemical functions present on the surface of the reinforcing charge.

[0068] Preferably, when the reinforcing charge comprises predominantly an inorganic reinforcing charge, preferably a silica, the functionalized E2 diene elastomer may comprise at least one chemical function capable of interacting with the reinforcing charge, the chemical function comprising at least one heteroatom selected from the group consisting of nitrogen, sulfur, oxygen and phosphorus.

[0069] Preferably, the chemical function capable of interacting with the reinforcing charge of the diene elastomer E2 is a polar function comprising at least one oxygen atom.

[0070] Preferably, the polar function can be chosen from the group consisting of silanol, alkoxysilanes, alkoxysilanes bearing an amine group, epoxide, ethers, esters, carboxylic acids, and hydroxyl. Such functionalized elastomers are known per se and are described in particular in the following documents: FR2740778, US6013718, WO2008 / 141702, FR2765882, WO01 / 92402, WO2004 / 09686, EP1127909, US6503973, WO2009 / 000750, and WO2009 / 000752.

[0071] Preferably, the functionalized diene elastomer is a diene elastomer having a polar function which is a silanol.

[0072] Preferably, silanol is located at the end of the chain or in the middle of the main chain of the functionalized diene elastomer.

[0073] Preferably, the functionalized diene elastomer can be a diene elastomer (in particular an SBR) in which the silanol function is located at the end of the chain. This functionalized diene elastomer comprises at one end of its main chain a silanol function or a polysiloxane group having a silanol end of formula -(SiR1R2-O-)mH, where m represents an integer from 3 to 8, preferably 3, and R1 and R2, which may be the same or different, represent an alkyl radical of 1 to 10 carbon atoms, preferably an alkyl radical having 1 to 4 carbon atoms.

[0074] This type of elastomer can be obtained according to the processes described in document EP0778311 and more particularly according to the process consisting, after an anionic polymerization step, of functionalizing the living elastomer with a cyclic polysiloxane functionalizing agent. Examples of cyclic polysiloxanes include those corresponding to formula (V) where m represents an integer from 3 to 8, preferably 3, R1 and R2, identical or different, represent an alkyl radical of 1 to 10 carbon atoms, preferably an alkyl radical of 1 to 4 carbon atoms. Hexamethylcyclotrisiloxane is one such compound.

[0075] The functionalized E2 diene elastomer can be a diene elastomer (in particular an SBR) containing a polar function that is an alkoxysilane, with or without another functional group, notably an amine group. Preferably, the alkoxysilane, with or without another functional group (preferably bearing an amine group), is located at the end or in the middle of the chain of the main chain of the functionalized diene elastomer; more preferably, the alkoxysilane group, with or without the amine group, is located in the middle of the chain of the main chain of the functionalized diene elastomer.

[0076] Thus, the functionalized E2 diene elastomer may include within its structure at least one alkoxysilane group and at least one other function, the silicon atom of the alkoxysilane group being linked to the elastomer chain(s), the alkoxysilane group possibly being partially or totally hydrolyzed to silanol.

[0077] According to some variants, the alkoxysilane group is located predominantly at one end of the main chain of the elastomer.

[0078] According to other variations, the alkoxysilane group is located predominantly in the main elastomer chain; in this case, the diene elastomer is said to be coupled or functionalized in the middle of the chain, as opposed to a position at the "end of the chain," even though the group is not precisely located in the middle of the elastomer chain. The silicon atom of this functional group connects the two branches of the main chain of the diene elastomer.

[0079] The alkoxysilane group comprises a C1-C10 alkoxyl radical, possibly partially or totally hydrolyzed to hydroxyl, or even to C1-C8, preferably to C1-C4, and is more preferentially methoxy and ethoxy.

[0080] The other function is preferably carried by the silicon of the alkoxysilane group, either directly or via a spacer group defined as an atom or a group of atoms. Preferably, the spacer group is a divalent hydrocarbon radical, linear or branched, aliphatic in the C1-C18 range, saturated or unsaturated, cyclic or non-cyclic, or an aromatic divalent hydrocarbon radical in the C6-C18 range.

[0081] The other function is preferably a function comprising at least one heteroatom chosen from N, S, O, P. Examples of these functions include primary, secondary or tertiary amines, cyclic or non-cyclic, isocyanates, imines, cyano, thiols, carboxylates, epoxides, and primary, secondary or tertiary phosphines.

[0082] Thus, as secondary or tertiary amine functional groups, we can cite amines substituted by alkyl radicals in the C1-C10 position, preferably alkyl radicals in the C1-C4 position, and more preferably methyl or ethyl radicals, or cyclic amines forming a heterocycle containing a nitrogen atom and at least one carbon atom, preferably 2 to 6 carbon atoms. For example, suitable groups include methylamino-, dimethylamino-, ethylamino-, diethylamino-, propylamino-, dipropylamino-, butylamino-, dibutylamino-, pentylamino-, dipentylamino-, hexylamino-, dihexylamino-, and hexamethyleneamino-, preferably diethylamino- and dimethylamino-. As imine functional groups, we can cite ketimines. For example, suitable groups include (1,3-dimethylbutylidene)amino-, (ethylidene)amino-, (1-methylpropylidene)amino-, (4-N,N-dimethylaminobenzylidene)amino-, (cyclohexylidene)amino-, dihydroimidazole and imidazole.Thus, acrylates or methacrylates can be used as carboxylate functional groups. A methacrylate is preferably used for such groups. Epoxy groups can be used as epoxy groups or glycidyloxy groups. Secondary or tertiary phosphine functional groups can be used, such as phosphines substituted with C1-C10 alkyl radicals, preferably C1-C4 alkyl radicals, more preferably a methyl or ethyl radical, or diphenylphosphine. For example, methylphosphino-, dimethylphosphino-, ethylphosphino-, diethylphosphino-, ethylmethylphosphino-, and diphenylphosphino- groups are suitable.

[0083] The other function is preferably a tertiary amine, more preferably a diethylamino- or dimethylamino- group.

[0084] The alkoxysilane group can be represented by the formula (*-) a Si(OR') b R c X in which, *- represents the bond to an elastomer chain; the radical R represents an alkyl radical, substituted or unsubstituted, in C1-C10, or even in C1-C8, preferably an alkyl radical in C1-C4, more preferably methyl and ethyl; in the alkoxyl radical(s) of formula -OR', possibly partially or totally hydrolyzed to hydroxyl, R' represents an alkyl radical, substituted or unsubstituted, being in C1-C10, or even in C1-C8, preferably an alkyl radical in C1-C4, more preferably methyl and ethyl; X represents a group including the other function; a is 1 or 2, b is 1 or 2, and c is 0 or 1, provided that a + b + c = 3.

[0085] This type of elastomer is primarily obtained by functionalizing a live elastomer produced by anionic polymerization with a compound containing an alkoxysilane group, specifically chosen from among the trialcoxysilane and dialcoxyalkylsilane compounds substituted with a group containing another functional group directly or via a spacer group to the silicon atom, the functional group and spacer group being as defined above. It should be noted that it is known to those skilled in the art that when an elastomer is modified by the reaction of a functionalizing agent with the live elastomer produced by an anionic polymerization step, a mixture of modified species of this elastomer is obtained, the composition of which depends on the conditions of the modification reaction and, in particular, on the proportion of reactive sites of the functionalizing agent relative to the number of live elastomer chains.This mixture includes chain-end functionalized, coupled, star-shaped and / or non-functionalized species.

[0086] Preferably, the proportion of the E2 diene elastomer functionalized in the composition of the invention is in the range of 30% to 50%, preferably from 30% to 45%, more preferably from 35% to 45%.

[0087] These non-functional diene elastomers are commercially available from suppliers such as Nippon Zeon, JSR, Bayer etc. or can be synthesized using known processes. Reinforcing load

[0088] The rubber composition of the invention may include one or more reinforcing fillers capable of interacting with the diene elastomer E2.

[0089] Any type of so-called reinforcing filler can be used, known for its ability to strengthen a rubber composition usable in particular for the manufacture of pneumatic tires, for example an organic filler such as carbon black, an inorganic filler such as silica or a mixture of these two types of fillers.

[0090] The term "reinforcing filler capable of interacting with the functionalized diene elastomer" refers to any reinforcing filler, particularly inorganic such as silica, capable of forming a physical or chemical bond within a rubber composition through a functionalized diene elastomer. This interaction can be established, for example, via covalent bonds, hydrogen bonds, ionic bonds, and / or electrostatic bonds between the functionalized elastomer and the functional groups present on the surface of the reinforcing fillers.

[0091] All carbon blacks are suitable, including those conventionally used in pneumatic or non-pneumatic tires or their treads. Among the latter, reinforcing carbon blacks of the 200 series, such as N234, are particularly relevant. These carbon blacks can be used on their own, as commercially available, or in other forms, for example, as a carrier for certain rubber additives. Carbon blacks could, for instance, already be incorporated into diene elastomers (see, for example, applications WO97 / 36724-A2 or WO99 / 16600-A1).

[0092] Examples of organic fillers other than carbon blacks include functionalized polyvinyl organic fillers as described in applications WO2006 / 069792-A1, WO2006 / 069793-A1, WO2008 / 003434-A1 and WO2008 / 003435-A1.

[0093] Preferably, the reinforcing filler capable of interacting with the diene elastomer E2 predominantly comprises at least one reinforcing inorganic filler, and even more preferably comprises predominantly at least one silica.

[0094] The term "reinforcing inorganic filler" here refers to any inorganic or mineral filler, regardless of its color or origin (natural or synthetic), also called "white" filler, "light" filler, or even "non-black" filler (as opposed to carbon black), capable of reinforcing, on its own and without the need for an intermediate coupling agent, a rubber composition intended for the manufacture of pneumatic or non-pneumatic tires. As is known, some reinforcing inorganic fillers are characterized, in particular, by the presence of hydroxyl groups (-OH) on their surface.

[0095] Suitable reinforcing inorganic fillers include mineral fillers of the siliceous type, preferably silica (SiO2) or of the aluminous type, in particular alumina (Al2O3).

[0096] The silica used may be any reinforcing silica known to those skilled in the art, in particular any precipitated or fumed silica having a specific surface area BET and a specific surface area CTAB both less than 450 m² / g, preferably within a range of 30 to 400 m² / g, in particular 60 to 300 m² / g. Any type of precipitated silica may be used, in particular highly dispersible precipitated silicas (known as "HDS" for "highly dispersible" or "highly dispersible silica"). These precipitated silicas, whether highly dispersible or not, are well known to those skilled in the art. Examples include the silicas described in applications WO03 / 016215-A1 and WO03 / 016387-A1.Among the commercial HDS silicas, one can notably use the silicas “Ulsil ®< 5000GR”, “Ulsil ®< 7000GR” from the company Evonik, the silicas “Zeosil ®< 1085GR”, “Zeosil ®< 1115 MP”, “Zeosil ®< 1165MP”, “Zeosil ®< Premium 200MP”, “Zeosil ®< HRS 1200 MP” from the Solvay Company. As non-HDS silica, the following commercial silicas may be used: “Ultrasil ®< VN2GR”, “Ultrasil ®< VN3GR” silicas from Evonik, “Zeosil ®< 175GR” silica from Solvay, “Hi-Sil EZ120G(-D)”, “Hi-Sil EZ160G(-D)”, “Hi-Sil EZ200G(-D)”, “Hi-Sil 243LD”, “Hi-Sil 210”, “Hi-Sil HDP 320G” silicas from PPG.

[0097] The physical state of the reinforcing inorganic filler is irrelevant, whether it be in the form of powder, microbeads, granules, spheres, or any other suitable densified form. Of course, the term "reinforcing inorganic filler" also refers to mixtures of different reinforcing inorganic fillers, particularly silicas as described above.

[0098] According to a preferred embodiment of the invention, the reinforcing filler is predominantly an inorganic reinforcing filler (preferably silica), that is, it comprises more than 50% (>50%) by weight of an inorganic reinforcing filler such as silica relative to the total weight of the reinforcing filler. Optionally, according to this embodiment, the reinforcing filler may also include carbon black. According to this option, the carbon black is used at a rate less than or equal to 20 parts per cent (ppt) in the rubber composition, more preferably less than or equal to 10 ppt (for example, the carbon black content may be in the range of 0.5 to 20 ppt, in particular from 1 to 10 ppt). Within the indicated ranges, the coloring (black pigmenting agent) and UV-resistant properties of carbon black are benefited without compromising the typical performance provided by the inorganic reinforcing filler.

[0099] Those skilled in the art will understand that, in place of the inorganic reinforcing filler described above, a reinforcing filler of another nature could be used, provided that this reinforcing filler of another nature is 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 this reinforcing filler and the diene elastomer.

[0100] A person skilled in the art will be able to adapt the total reinforcing load rate according to the intended use, in particular according to the type of pneumatic tires concerned, for example pneumatic tires for motorcycles, for passenger vehicles or for utility vehicles such as vans or heavy goods vehicles.

[0101] Preferably, the rate of reinforcing filler in the rubber composition is in the range of 20 to 100 parts per annum, more preferably 30 to 90 parts per annum, and even more preferably 40 to 90 parts per annum; the optimum being known to differ according to the particular applications intended.

[0102] In this presentation, the specific surface area BET is determined by gas adsorption using the Brunauer-Emmett-Teller method described in "The Journal of the American Chemical Society" (Vol. 60, page 309, February 1938), and more specifically according to a method adapted from the standard NF ISO 5794-1, Annex E of June 2010 [multipoint volumetric method (5 points) - gas: nitrogen - degassing under vacuum: one hour at 160°C - relative pressure range w / in: 0.05 to 0.17]. For inorganic fillers such as silica, the CTAB specific surface area values ​​were determined according to NF ISO 5794-1, Annex G of June 2010. The process is based on the adsorption of CTAB (N-hexadecyl-N,N,N-trimethylammonium bromide) onto the external surface of the reinforcing filler. For carbon blacks, the STSA specific surface area is determined according to ASTM D6556-2016.

[0103] Inorganic reinforcing charge coupling agents: As seen above, the reinforcing charge alone is capable of interacting with the functionalized E2 diene elastomer.

[0104] However, when the reinforcing filler is an inorganic filler, such as silica for example, it may be advantageous to increase the reinforcing power of this filler by using a coupling agent that allows the reinforcing inorganic filler to be coupled to the diene elastomer.

[0105] Any well-known coupling agent (or bonding agent) that is at least bifunctional can be used to ensure sufficient chemical and / or physical connection between the inorganic filler (the surface of its particles) and the diene elastomer. Organosilanes or polyorganosiloxanes that are at least bifunctional are particularly useful. "Bifunctional" means a compound possessing a first functional group capable of interacting with the inorganic filler and a second functional group capable of interacting with the diene elastomer. For example, such a bifunctional compound might include a first functional group comprising a silicon atom, which is capable of interacting with the hydroxyl groups of an inorganic filler, and a second functional group comprising a sulfur atom, which is capable of interacting with the diene elastomer.

[0106] Preferably, organosilanes are chosen from the group consisting of polysulfide organosilanes (symmetric or asymmetric) such as bis(3-triethoxysilylpropyl) tetrasulfide, abbreviated TESPT and marketed under the name "Si69" by Evonik, or bis-(triethoxysilylpropyl) disulfide, abbreviated TESPD and marketed under the name "Si75" by Evonik; polyorganosiloxanes; mercaptosilanes; and blocked mercaptosilanes, such as S-(3-(triethoxysilyl)propyl) octanethioate, marketed by Momentive under the name "NXT Silane". More preferably, the organosilane is a polysulfide organosilane.

[0107] Of course, mixtures of the coupling agents described above could also be used.

[0108] The coupling agent content in the rubber composition of the invention is advantageously less than or equal to 20 parts per thousand (ppm), it being understood that it is generally desirable to use as little as possible. Typically, the coupling agent content represents 0.5% to 15% by weight relative to the amount of reinforcing inorganic filler. Its content is preferably in the range of 0.5% to 20 ppm. This content is easily adjusted by those skilled in the art according to the amount of reinforcing inorganic filler used in the composition of the invention. Debt collectors

[0109] Rubber compositions may also contain coating agents for the reinforcing inorganic filler when a reinforcing inorganic filler is used, thereby improving their workability in the raw state. These recovery agents are well known (see for example patent applications WO2006 / 125533-A1, WO2007 / 017060-A1 and WO2007 / 003408-A1), examples include hydrolyzable silanes such as hydroxysilanes (see for example WO2009 / 062733-A2), alkylalkoxysilanes, polyols (for example diols or triols), polyethers (for example polyethylene glycols), primary, secondary or tertiary amines, hydroxylated or hydrolyzable polyorganosiloxanes (for example α,ω-dihydroxy-polyorganosilanes (see for example EP0784072-A1). Crosslinking system

[0110] The rubber compositions of the invention comprise at least one crosslinking system. The crosslinking system may be any type of system known to those skilled in the art in the field of rubber compositions for pneumatic or non-pneumatic tires. It may, in particular, be sulfur-based, and / or peroxide-based, and / or bismaleimide-based.

[0111] Preferably, the crosslinking system is sulfur-based; this is then referred to as a vulcanization system. The sulfur can be supplied in any form, including molecular sulfur or a sulfur-donating agent. At least one vulcanization accelerator is also preferably present, and optionally, various known vulcanization activators may be used, such as zinc oxide, stearic acid, or equivalent compounds like stearic acid salts and transition metal salts, guanidine derivatives (especially diphenylguanidine), or known vulcanization retarders.

[0112] Sulfur is used at a preferential rate in the range of 0.5 to 12 parts per million (ppm), more preferably in the range of 0.7 to 10 ppm. Vulcanization accelerator is used at a preferential rate in the range of 0.5 to 10 ppm, more preferably in the range of 0.5 to 5.0 ppm.

[0113] Any compound capable of acting as a vulcanization accelerator for diene elastomers in the presence of sulfur can be used as an accelerator, including thiazole-type accelerators and their derivatives, sulfenamide-type accelerators, thiurams, dithiocarbamates, dithiophosphates, thioureas and xanthates. Plasticizers

[0114] The rubber composition according to the invention may include at least one plasticizer.

[0115] As is known to those skilled in the art of rubber compounds for pneumatic or non-pneumatic tires, this plasticizer is preferably selected from high glass transition temperature (Tg) hydrocarbon resins, low Tg hydrocarbon resins, plasticizing oils, and mixtures thereof.

[0116] As is known, plasticizers in rubber compositions allow the viscosity of a rubber composition to be modified, and the glass transition temperature of the rubber composition to be adjusted relative to its optimum use.

[0117] A high Tg hydrocarbon resin is by definition a solid at ambient temperature and pressure (20°C, 1 atm), while a plasticizing oil is liquid at ambient temperature and pressure and a low Tg hydrocarbon resin is viscous at ambient temperature and pressure.

[0118] Hydrocarbon resins, also called hydrocarbon plasticizing resins, are polymers well known to those skilled in the art, primarily based on carbon and hydrogen but potentially containing other types of atoms, such as oxygen, which are particularly useful as plasticizing agents. They are inherently at least partially miscible (i.e., compatible) at the ratios used with the rubber compositions for which they are intended, so as to act as true diluents. They were described, for example, in the book entitled "Hydrocarbon Resins" by R. Mildenberg, M. Zander, and G. Collin (New York, VCH, 1997, ISBN 3-527-28617-9), Chapter 5 of which is devoted to their applications, particularly in the production of rubber for pneumatic tires (5.5. "Rubber Tires and Mechanical Goods").As is known, these hydrocarbon resins can also be classified as thermoplastic resins in that they soften upon heating and can thus be molded. The softening point of hydrocarbon resins is measured according to ISO 4625 (Ring and Ball method). The Tg is measured according to ASTM D3418 (2008). The macrostructure (Mw, Mn and Ip) of the hydrocarbon resin is determined by size exclusion chromatography (SEC): tetrahydrofuran solvent; temperature 35°C; concentration 1 g / l; flow rate 1 ml / min; solution filtered through a 0.45 µm porosity filter before injection; Moore calibration with polystyrene standards; set of 3 WATERS columns in series ("STYRAGEL" HR4E, HR1 and HR0.5); detection by differential refractometer (“WATERS 2410”) and its associated operating software (“WATERS EMPOWER”).Hydrocarbon resins can be aliphatic, aromatic, or aliphatic / aromatic, meaning they are based on aliphatic and / or aromatic monomers. They can be natural or synthetic, and may or may not be petroleum-based (in which case they are also known as petroleum resins). High-Tg hydrocarbon resins are known to be thermoplastic hydrocarbon resins with a Tg value above 20°C.

[0119] Preferably, the plasticizer may optionally comprise a hydrocarbon resin, solid at ambient temperature and pressure, referred to as a high-Tg resin. Preferably, the high-Tg hydrocarbon plasticizing resin has at least one of the following characteristics: a Tg greater than 30°C; a number average molecular mass (Mn) between 300 and 2000 g / mol, more preferably between 400 and 1500 g / mol; a polymolecularity index (Ip) less than 3, more preferably less than 2 (reminder: Ip = Mw / Mn with Mw weight average molecular mass).

[0120] More preferably, this high Tg hydrocarbon plasticizing resin exhibits all the above preferred characteristics.

[0121] The plasticizer may optionally include a viscous hydrocarbon resin at 20°C, known as "low Tg", that is to say, which by definition has a Tg within a range of -40°C to 20°C.

[0122] Preferably, the low Tg hydrocarbon plasticizing resin exhibits at least one of the following characteristics: a Tg between -40°C and 0°C, more preferably between -30°C and 0°C and more preferably between -20°C and 0°C; a number-average molecular weight (Mn) less than 800 g / mol, preferably less than 600 g / mol and more preferably less than 400 g / mol; a softening point within a range of 0 to 50°C, preferably 0 to 40°C, more preferably 10 to 40°C, preferably 10 to 30°C; a polymolecularity index (Ip) less than 3, more preferably less than 2 (reminder: Ip = Mw / Mn with Mw weight-average molecular weight).

[0123] More preferably, this low Tg hydrocarbon resin exhibits all the above preferential characteristics.

[0124] The plasticizer may also contain a liquid extending oil (or plasticizing oil) at 20°C, referred to as a "low Tg" oil, meaning that by definition it has a Tg below -20°C, preferably below -40°C. Any extending oil, whether aromatic or non-aromatic, known for its plasticizing properties with respect to elastomers, is suitable. At room temperature (20°C), these oils, which vary in viscosity, are liquids (that is, substances capable of eventually taking the shape of their container), unlike high Tg hydrocarbon resins, which are solid at room temperature.Particularly suitable are plasticizing oils chosen from the group consisting of naphthenic oils (low or high viscosity, including hydrogenated or non-hydrogenated), paraffinic oils, MES (Medium Extracted Solvates) oils, TDAE (Treated Distillate Aromatic Extracts) oils, RAE (Residual Aromatic Extract) oils, TRAE (Treated Residual Aromatic Extract) oils and SRAE (Safety Residual Aromatic Extract) oils, mineral oils, vegetable oils, ether plasticizers, ester plasticizers, phosphate plasticizers, sulfonate plasticizers and mixtures of these compounds.

[0125] The above-mentioned high Tg hydrocarbon resins, low Tg hydrocarbon resins, and preferred plasticizing oils are well known to those skilled in the art and are commercially available. Other additives

[0126] Rubber compositions according to the invention may also include all or part of the usual additives and processing agents known to those skilled in the art and commonly used in rubber compositions for pneumatic or non-pneumatic tires, in particular for treads, such as, for example, fillers (reinforcing or non-reinforcing / other than those mentioned above), pigments, protective agents such as anti-ozone waxes, chemical anti-ozonants, antioxidants, anti-fatigue agents, reinforcing resins (such as described, for example, in application WO 02 / 10269). Obtaining rubber compositions according to the invention

[0127] The rubber composition can be obtained by the usual processes of manufacturing rubber compositions such as the dry mixing of the different ingredients.

[0128] According to one embodiment, the rubber composition according to the invention is manufactured in suitable mixers, using two successive preparation phases well known to those skilled in the art: A first thermomechanical working or mixing phase (the so-called "non-productive" phase) can be carried out in a single thermomechanical step during which the functionalized diene elastomer E2, having a glass transition temperature TgE2, the reinforcing filler, and optionally the reinforcing filler coupling agent, are introduced into a suitable mixer such as a standard internal mixer (e.g., a Banbury type mixer) in the following sequential order. After thermomechanical mixing during which these ingredients are maintained at a temperature in the range of 140°C to 200°C for one to two minutes, the unfunctionalized diene elastomer E1, having a glass transition temperature TgE1, along with all the necessary constituents, with the exception of the crosslinking system, is introduced into the internal mixer.These ingredients undergo thermomechanical mixing for 2 to 10 minutes up to a maximum temperature within a range of 110°C to 200°C, preferably from 130°C to 185°C (and referred to as the "falling temperature"); a second mechanical working phase (the so-called "productive phase") is carried out in an external mixer such as a roller mixer, after cooling the mixture obtained during the first non-productive phase to a lower temperature, typically below 120°C, for example within a range of 40°C to 100°C. The crosslinking system is then incorporated by mixing for 5 to 15 minutes to obtain the rubber mixture of the invention.

[0129] According to another preferred embodiment of the invention, the rubber composition of the invention is prepared in the form of two masterbatches, and then the masterbatches are mixed so as to obtain the rubber composition according to the invention.

[0130] More specifically, according to this embodiment, a first masterbatch is prepared by mixing the unfunctionalized diene elastomer E1 and any other constituents, such as plasticizer(s), anti-ozonant, etc., with the exception of the vulcanization system, in a suitable mixer such as a standard internal mixer (e.g., a Banbury mixer). Thermomechanical work is then carried out for 2 to 10 minutes until a maximum temperature is reached, preferably between 130°C and 185°C (the "dropping temperature"). The first masterbatch, comprising at least the unfunctionalized diene elastomer E1, is thus obtained.

[0131] A second masterbatch is then prepared by mixing the functionalized diene elastomer E2, the reinforcing filler, and any other constituents such as the reinforcing filler coupling agent and / or plasticizer(s), anti-ozonant, etc., in a suitable mixer such as a standard internal mixer (e.g., a Banbury mixer), excluding the vulcanizing system. Thermomechanical work is carried out for 2 to 10 minutes until a maximum temperature is reached, preferably between 140°C and 200°C (and referred to as the "dropping temperature"). The resulting second masterbatch comprises at least the functionalized diene elastomer E2 and the reinforcing filler capable of interacting with the functionalized diene elastomer E2.

[0132] The two master mixtures from the previous steps are introduced into a conventional internal mixer (for example, of the "Banbury" type) and thermomechanical work is carried out for 2 to 10 minutes until a maximum temperature is reached in a range of 110°C to 180°C, preferably ranging from 130°C to 180°C (and called the "falling temperature").

[0133] The mixture from the previous step is then cooled on an external mixer such as a roller mixer to a temperature of 110°C or less. The crosslinking system is then incorporated by mixing for 5 to 15 minutes, and the rubber composition is recovered.

[0134] Regardless of the method of preparing the rubber composition, the final composition thus obtained is then calendered, for example in the form of a sheet or plate, particularly for characterization in the laboratory, or extruded in the form of a semi-finished (or profile) of rubber usable, for example, as a tread of a pneumatic or non-pneumatic tire, particularly for passenger vehicles.

[0135] The composition can be either in the raw state (before crosslinking or vulcanization), or in the cooked state (after crosslinking or vulcanization), and can be a semi-finished product that can be used in a pneumatic or non-pneumatic bandage.

[0136] The crosslinking of the rubber composition can be carried out in a manner known to those skilled in the art, for example at a temperature within a range of 130°C to 200°C, under pressure. Other objects of the invention

[0137] Another object of the present invention relates to a tread comprising at least one composition defined above. The rubber composition according to the invention may constitute the entire tread or a portion of the tread.

[0138] Another object of the present invention relates to a pneumatic or non-pneumatic tire comprising at least one composition defined above or one tread defined above.

[0139] A "pneumatic tire" is a tire designed to form a cavity by cooperating with a supporting element, such as a rim. This cavity is capable of being pressurized to a pressure higher than atmospheric pressure. In contrast, a "non-pneumatic tire" is not capable of being pressurized. Thus, a non-pneumatic tire is a toroidal body made of at least one polymeric material, designed to perform the function of a tire but without being subjected to inflation pressure. A non-pneumatic tire can be solid or hollow. A hollow non-pneumatic tire may contain air, but at atmospheric pressure; that is, it lacks the pneumatic rigidity provided by an inflation gas at a pressure higher than atmospheric pressure.

[0140] The pneumatic tires according to the invention are intended for use on all types of vehicles, including passenger cars, motorcycles, trucks, agricultural vehicles, construction equipment, and aircraft, or more generally, on any rolling device. Non-pneumatic tires are intended for use on passenger cars and motorcycles. Preferably, the pneumatic tires according to the invention are intended for use on passenger cars.

[0141] Preferably, the pneumatic or non-pneumatic tire includes at least one tread comprising at least one rubber composition defined above. MEASUREMENT METHODS Determination of the glass transition temperature of elastomers

[0142] The glass transition temperatures (Tg) of elastomers, before their use, are determined using a differential scanning calorimeter according to ASTM D3418:2008. Determination of the dynamic friction coefficient µ max

[0143] Dynamic friction coefficient measurements were performed using a method identical to that described by L. Busse, A. Le Gal, and M. Küppel (Modelling of Dry and Wet Friction of Silica Filled Elastomers on Self-Affine Road Surfaces, Elastomer Friction, 2010, 51, p. 8). The test specimens were produced by molding and then curing a 6 mm thick square (50 mm x 50 mm) rubber support. After the mold was closed, it was placed in a heated platen press at a temperature of 150°C and, for the time required to curing the material (typically several tens of minutes), at a pressure of 16 bar. The soil used for these measurements was a core sample taken from an actual road surface of BBTM-type bituminous concrete (NF P 98-137 standard).To prevent dewlipping and the development of unwanted adhesion forces between the soil and the material, the soil-specimen system is immersed in a 5% aqueous solution of a surfactant (Sinnozon - CAS number: 25155-30-0). The temperature of the aqueous solution is regulated using a thermostatic bath. The specimen is subjected to a sliding motion in translation parallel to the plane of the soil. The sliding velocity Vg is fixed at 1.2 m / s. The applied normal stress σn is 400 kPa (i.e., 4 bar). These conditions are described below as "wet soil conditions." The shear stress σt opposing the movement of the specimen on the soil is continuously measured. The ratio between the shear stress σt and the normal stress σn gives the coefficient of dynamic friction µ.The values ​​of the dynamic friction coefficient are measured during a temperature sweep of the aqueous solution, ranging from 3°C to 44°C, and are obtained in steady state after stabilization of the value of the tangential stress σt.

[0144] In the examples, the maximum value of the dynamic friction coefficient (denoted µ max) measured during this sweep is indicated.

[0145] Unless otherwise specified, results are given on a scale of 100. The arbitrary value of 100 is assigned to the comparative composition to calculate and then compare the maximum dynamic friction coefficient of the different samples tested. The value on a scale of 100 for the sample to be tested is calculated using the following formula: (maximum µ value of the sample to be tested / maximum µ value of the comparative composition) × 100. Therefore, a result below 100 indicates a decrease in the maximum dynamic friction coefficient and thus a reduction in wet grip performance. Conversely, a result above 100 indicates an increase in the maximum dynamic friction coefficient and thus an increase in wet grip performance. Measurement of dynamic properties after cooking.

[0146] The dynamic properties tan(δ) max are measured on a viscoelastic analyzer (Metravib V A4000), according to ASTM D 5992-96. The response of a vulcanized composite sample (two cylindrical specimens, 2 mm thick and with a cross-section of 78.5 mm²) is recorded under sinusoidal loading in alternating simple shear at a frequency of 10 Hz and a temperature of 40°C. A peak-to-peak strain amplitude sweep is performed from 1% to 100% (forward cycle), then from 100% to 1% (reverse cycle). The results used are the loss factor (tan(δ) max). For the reverse cycle, the maximum observed tan(δ) max value at 40°C is recorded.

[0147] The results are expressed as a base-100 performance value. This means that the comparative composition is arbitrarily assigned a value of 100 to calculate and then compare the maximum tangent (δmax) at 40°C of the different rubber compositions tested. The base-100 value is calculated using the following formula: (maximum tangent (δmax) at 40°C of the comparative composition / maximum tangent (δmax) at 40°C of the sample) * 100. Therefore, a lower value represents a decrease in hysteresis properties, while a higher value represents an improvement in hysteresis properties. EXAMPLES 1- Ingredients:

[0148] The ingredients used in the examples are as follows: Elastomer (1A): Styrene-butadiene copolymer, unfunctionalized, having a Tg of -28°C measured according to ASTM D3418:2008, a styrene content of 41% by weight relative to the total copolymer weight, a 1,2-vinyl butadiene content of 14% by weight relative to the total copolymer weight, a 1,4-trans butadiene content of 27% by weight relative to the total copolymer weight. Elastomer (1B): Styrene-butadiene copolymer bearing a silanol function at the end of the elastomer chain, and having a Tg of -24°C measured according to ASTM D3418:2008, a styrene content of 25% by weight relative to the total weight of the copolymer, a 1,2-vinyl butadiene content of 43% by weight relative to the total weight of the copolymer, a 1,4-trans butadiene content of 16% by weight relative to the total weight of the copolymer.Elastomer (1C): Styrene-butadiene copolymer having a Tg of -65°C measured according to ASTM D3418:2008, a styrene content of 16% by weight relative to the total copolymer weight, a 1,2-vinyl butadiene content of 20% by weight relative to the total copolymer weight, and a 1,4-trans butadiene content of 39% by weight relative to the total copolymer weight. Elastomer (1D): Styrene-butadiene copolymer bearing an amino-alkoxysilane function in the middle of the chain and having a Tg of -65°C measured according to ASTM D3418:2008, a styrene content of 16% by weight relative to the total weight of the copolymer, a 1,2-vinyl butadiene content of 20% by weight relative to the total weight of the copolymer, a 1,4-trans butadiene content of 39% by weight relative to the total weight of the copolymer.Elastomer (1F): Styrene-butadiene copolymer bearing an amino-alkoxysilane function in the middle of the chain and having a Tg of -48°C measured according to ASTM D3418:2008, a styrene content of 27% by weight relative to the total weight of the copolymer, a 1,2-vinyl butadiene content of 17.5% by weight relative to the weight of the copolymer, a 1,4-trans butadiene content of 33.5% by weight relative to the total weight of the copolymer. Elastomer (1G): Non-functionalized styrene-butadiene copolymer having a Tg of -48°C measured according to ASTM D3418:2008, a styrene content of 27% by weight relative to the total weight of the copolymer, a 1,2-vinyl butadiene content of 17.5% by weight relative to the total weight of the copolymer, a 1,4-butadiene content of 33.5% by weight relative to the total weight of the copolymer. Carbon black (2): ASTM N234 grade carbon black marketed by Cabot Corporation.

[0149] Silica (3): Silica “Zeosil 1165MP” marketed by Solvay. Silane (4): Bis[3-(triethoxysilyl)propyl] tetrasulfide silane (TESPT) marketed by Evonik under the reference “Si69”. DPG (5): Diphenylguanidine “Perkacit DPG” from Flexsys. Plasticizer (6): DCPD resin with a softening point of 100 °C and a glass transition temperature of 51 °C, marketed under the reference “PR-383” by Exxon Mobil. Ozone-fighting wax (7): Ozone-fighting wax “VARAZON 4959” from Sasol Wax. Antioxidant (8): N-1,3-dimethylbutyl-N-phenyl-para-phenylenediamine marketed by Flexys under the reference “Santoflex 6-PPD”. ZnO (9): Zinc oxide (industrial grade) marketed by the company Umicore.

[0150] Stearic acid (10): Stearine “Pristerene 4031” marketed by the company Uniquema. 2. Test 1: Impact of the location of reinforcing fillers in the rubber composition

[0151] The examples presented in Table 1 are intended to compare the different rubber properties of the rubber composition CI1 according to the invention with a series of comparative rubber compositions CC1 and CC2.

[0152] Table 1 shows the formulation of these rubber compositions; the proportions are expressed in parts by weight, i.e., parts by weight per 100 parts by weight of the elastomers in the composition. Table 1 CC1 CC2 CI1 Elastomer (1A) 50,0 0,0 60,0 Elastomer (1B) 0,0 40,0 0,0 Elastomer (1C) 50,0 60,0 0,0 Elastomer (1D) 0,0 0,0 40,0 Black (2) 3,8 3,8 3,8 Silica (3) 55,0 55,0 55,0 Silane (4) 4,4 4,4 4,4 DPG (5) 1,2 1,2 1,2 Plasticizer (6) 16,0 16,0 16,0 Anti-ozone wax (7) 2,0 2,0 2,0 Antioxidant (8) 1,0 1,0 1,0 ZnO (9) 2,5 2,5 2,5 Stearic acid (10) 2,0 2,0 2,0 Sulfur 1,8 1,8 1,8 CBS 2,2 2,2 2,2

[0153] The comparative rubber composition CC1 is obtained from two masterbatches, masterbatch 1 and masterbatch 2, obtained by dry mixing according to the following process: In a 414 cm³ internal "Polylab" mixer, filled to 70% by volume and with an initial chamber temperature of 90°C, all the ingredients listed in Table 2 are introduced, in one or more stages. Thermomechanical work is carried out for 6 minutes until a maximum temperature drop of 165°C is reached. The resulting mixture, called masterbatch 1, is then collected.

[0154] In another internal "Polylab" mixer of 414 cm³, filled to 70% by volume and with an initial vessel temperature of 90°C, all the ingredients from Table 3 are introduced in one or more batches. Thermomechanical work is carried out for 6 minutes until a maximum temperature drop of 165°C is reached. The resulting mixture, called master mix 2, is collected.

[0155] The master mix 1 and master mix 2 obtained previously are then introduced into an internal "Polylab" mixer of 414 cm3, filled to 70% by volume, and thermomechanical work is carried out for a period of 5 min until a maximum drop temperature of 150°C is reached.

[0156] The mixture from the previous step is then introduced into an external mixer, such as a drum mixer, to cool it to a temperature of 40°C. The crosslinking system (1.8 parts sulfur and 2.2 parts CBS (N-cyclohexyl-2-benzothiazyl-sulfenamide, marketed by Flexys under the name "Santocure CBS")) is then incorporated and mixed for 20 minutes. The resulting rubber compound is then calendered into sheets for measurement of its physical and mechanical properties. Unless otherwise specified, the rubber compound's rubber properties are measured after curing at 170°C for 20 minutes. Table 2 Elastomer (1A) 50,0 Black (2) 1,9 Silica (3) 27,5 Silane (4) 2,2 masterbatch 1-CC1 DPG (5) 0,6 Plasticizer (6) 8,0 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,3 Stearic acid (10) 1,00 Table 3 Elastomer (1C) 50,0 Black (2) 1,9 Silica (3) 27,5 Silane (4) 2,2 mastermixture 2-CC1 DPG (5) 0,6 Plasticizer (6) 8,0 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,2 Stearic acid (10) 1,0

[0157] The comparative rubber composition CC2 and the rubber composition of the invention CI1 are prepared according to the process described for the rubber composition CC1, with mastermixtures 1 and 2 from Tables 4 and 5 respectively for the comparative composition CC2 and mastermixtures 1 and 2 from Tables 6 and 7 for the rubber composition of the invention CI1. Table 4 Elastomer (1B) 40,0 Black (2) 3,8 Silica (3) 39,7 Silane (4) 3,2 masterbatch 1-CC2 DPG (5) 0,6 Plasticizer (6) 9,4 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,0 Stearic acid (10) 0,8 Table 5 Elastomer (1C) 60,0 Black (2) 0,0 Silica (3) 15,3 Silane (4) 1,2 mastermixture 2-CC2 DPG (5) 0,6 Plasticizer (6) 6,6 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,5 Stearic acid (10) 1,2 Table 6 Elastomer (1A) 60,0 Black (2) 0,0 Silica (3) 15,3 Silane (4) 1,2 masterbatch 1-CI1 DPG (5) 0,6 Plasticizer (6) 6,6 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,5 Stearic acid (10) 1,2 Table 7 Elastomer (1D) 40,0 Black (2) 3,8 Silica (3) 39,7 Silane (4) 3,2 masterbatch 2-CI1 DPG (5) 0,6 Plasticizer (6) 9,4 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,0 Stearic acid (10) 0,8

[0158] The rubber properties of the CC1, CC2 and CI1 rubber compositions, measured after baking, are presented in Table 8. Table 8 CC1 CC2 CI1 Glass transition temperature of elastomers (measured in °C) TgE1 -28°C -24°C -28°C TgE2 -65°C -65°C -65°C Tan δ max at 40°C (base 100) 100 98 116 µ max (base 100) 100 86 105

[0159] Although containing the same amount of reinforcing fillers (58.8 parts per cubic centimeter), the rubber composition of invention CI1 differs from the comparative rubber compositions CC1 and CC2 in that the reinforcing fillers, particularly silica, interact with the elastomer having the lowest glass transition temperature, i.e., with the elastomer with a glass transition temperature of TgE2. The rubber composition CC1, which does not include a functionalized elastomer, exhibits a homogeneous distribution of reinforcing fillers between the two elastomers with different glass transition temperatures. In the rubber composition CC2, the reinforcing fillers interact with the functionalized elastomer having the highest glass transition temperature, i.e., with the elastomer with a glass transition temperature of TgE1.

[0160] Compared to the CC1 rubber compound, which exhibits a homogeneous distribution of the reinforcing filler within the elastomeric matrix, the CC2 rubber compound, for equivalent hysteresis properties (tan δ max at 40°C), shows a significant decrease in the µ max coefficient, thus reducing wet grip performance. Therefore, when the reinforcing fillers interact with the elastomer having the highest glass transition temperature, in this case TgE1 for the CC2 rubber compound, a degradation of wet grip performance is observed for hysteresis properties equivalent to those of the CC1 rubber compound.

[0161] Surprisingly, when the reinforcing fillers interact with the elastomer having the lowest glass transition temperature (Tg) (in this case, the functionalized elastomer with a glass transition temperature TgE2, see the rubber composition according to the invention CI1), a significant improvement in hysteresis properties is observed compared to the comparative rubber composition CC1, along with an increase in the µmax coefficient, thus improving wet grip performance. This result is surprising because the improvement in hysteresis properties does not come at the expense of wet grip performance. 3. Test 2: Impact of the glass transition temperature difference of the elastomers forming the rubber composition

[0162] The examples presented in Table 9 are intended to compare the different rubber properties of the rubber composition CI1 according to the invention with respect to two comparative rubber compositions CC3 and CC4.

[0163] Table 9 shows the formulation of the tested rubber compositions, the proportions are expressed in parts by weight, i.e. parts by weight per 100 parts by weight of the elastomers in the composition. Table 9 CC3 CC4 CC1 Elastomer (1A) 60,0 0,0 60,0 Elastomer (1D) 0,0 40,0 40,0 Elastomer (1F) 40,0 0,0 0,0 Elastomer (1G) 0,0 60,0 0,0 Black (2) 3,8 3,8 3,8 Silica (3) 55,0 55,0 55,0 Silane (4) 4,4 4,4 4,4 DPG (5) 1,2 1,2 1,2 Plasticizer (6) 16,0 16,0 16,0 Anti-ozone wax (7) 2,0 2,0 2,0 Antioxidant (8) 1,0 1,0 1,0 ZnO (9) 2,5 2,5 2,5 Stearic acid (10) 2,0 2,0 2,0 Sulfur 1,8 1,8 1,8 CBS 2,2 2,2 2,2

[0164] The CC3 rubber composition and the CC4 rubber composition are prepared according to the test 1 process, with the mastermixes from Table 6 (mastermix 1-CI1) and Table 10 (mastermix 2-CC3) respectively for the CC3 rubber composition and the mastermixes from Table 11 (mastermix 1-CC4) and Table 7 (mastermix 2-CC1) for the CC4 rubber composition. Table 10 Elastomer (1F) 40,0 Black (2) 3,8 Silica (3) 39,7 Silane (4) 3,2 mastermixture 2-CC3 DPG (5) 0,6 Plasticizer (6) 9,4 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,0 Stearic acid (10) 0,8 Table 11 Elastomer (1G) 60,0 Black (2) 0,0 Silica (3) 15,3 Silane (4) 1,2 masterbatch 1-CC4 DPG (5) 0,6 Plasticizer (6) 6,6 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,5 Stearic acid (10) 1,2

[0165] The rubbery properties of these compositions, measured after cooking, are presented in Tables 12 and 13. Table 12 CC3 CI1 Glass transition temperature of elastomers (measured in °C) TgE1 -28°C -28°C TgE2 -48°C -65°C Tan δ max at 40°C (base 100) 100 117 µ max (base 100) 100 100

[0166] The rubber composition according to the invention CI1 differs from the comparative rubber composition CC3 by the elastomer with the lowest glass transition temperature (i.e. the glass transition temperature elastomer TgE2).

[0167] When the formulation of comparative composition CC3 is modified so that the glass transition temperature difference of the elastomers is greater than or equal to 23°C, the rubber composition according to invention CI1 is obtained, and it is observed that the hysteresis properties are significantly improved for the rubber composition of invention CI1 compared to comparative composition CC3.

[0168] Surprisingly, this improvement in the hysteresis properties of the rubber composition of invention CI1 does not come at the expense of the µ max coefficient, and therefore of the wet surface adhesion performance. Table 13 CC4 CI1 Glass transition temperature of elastomers (measured in °C) TgE1 -48°C -28°C TgE2 -65°C -65°C Tan δ max at 40°C (base 100) 100 98 µ max (base 100) 100 119

[0169] The rubber composition according to the invention CI1 differs from the comparative rubber composition CC4 by the elastomer with the highest glass transition temperature (i.e. the glass transition temperature elastomer TgE1).

[0170] When the formulation of the comparative composition CC4 is modified so that the glass transition temperature difference of the elastomers is greater than or equal to 23°C, the rubber composition according to the invention CI1 is obtained. The µmax coefficient is then found to be significantly improved compared to the CC4 composition. The rubber composition of the invention therefore exhibits superior wet grip performance compared to the comparative rubber composition CC4. Surprisingly, this improvement in wet grip performance does not come at the expense of hysteresis properties, which are equivalent to those of the comparative rubber composition CC4. 4. Essay 3: Comparison with a previous art

[0171] The examples presented in Table 14 are intended to compare the different rubber properties of the rubber composition CI1 according to the invention with a comparative rubber composition CC5 representative of Example 4 of document EP3372638A1. The formulation of the rubber composition CC5 is presented in Table 14, the proportions are expressed in pieces. Table 14 CC5 CI1 Elastomer (1F) 50,0 0,0 Elastomer (1D) 50,0 40,0 Elastomer (1A) 0,0 60,0 Black (2) 3,8 3,8 Silica (3) 55,0 55,0 Silane (4) 4,4 4,4 DPG (5) 1,2 1,2 Plasticizer (6) 16,0 16,0 Anti-ozone wax (7) 2,0 2,0 Antioxidant (8) 1,0 1,0 ZnO (9) 2,5 2,5 Stearic acid (10) 2,0 2,0 Sulfur 1,8 1,8

[0172] The CC5 rubber composition is prepared according to the test 1 process with the masterbatches from Tables 15 and 16 respectively. Table 15 Elastomer (1F) 50,0 Black (2) 1,9 Silica (3) 0,0 Silane (4) 0,0 mastermixture 1-CC5 DPG (5) 0,6 Plasticizer (6) 0,0 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,3 Stearic acid (10) 1,0 Table 16 Elastomer (1D) 50,0 Black (2) 1,9 Silica (3) 55,0 Silane (4) 4,4 mastermixture 2-CC5 DPG (5) 0,6 Plasticizer (6) 16,0 Anti-ozone wax (7) 1,0 Antioxidant (8) 0,5 ZnO (9) 1,2 Stearic acid (10) 1,0

[0173] The rubbery properties of the rubber compositions, measured after cooking, are presented in Table 17. Table 17 CC5 CI1 Glass transition temperature of elastomers (measured in °C) TgE1 -48°C -28°C TgE2 -65°C -65°C Tan δ max at 40°C (base 100) 100 99 µ max (base 100) 100 127

[0174] It is observed that the rubber composition according to invention CI1 exhibits a significantly improved µmax coefficient compared to the rubber composition CC5, which represents a prior art. This result indicates that the wet surface adhesion of the rubber composition according to invention CI1 is significantly better than the wet surface adhesion of the rubber composition CC5. Surprisingly, this significant improvement in the µmax coefficient does not come at the expense of hysteresis properties, since both rubber compositions exhibit the same δmax values ​​at 40°C.

[0175] All the tests presented above show that the rubber composition according to the invention MI1 exhibits a significant improvement in hysteresis properties, therefore a reduction in rolling resistance, while maintaining very good wet grip performance compared to the comparative rubber compositions.

Claims

1. Rubber composition based on at least one non-functionalized first diene elastomer E1 having a glass transition temperature TgE1, one functionalized second diene elastomer E2 having a glass transition temperature TgE2, a reinforcing filler capable of interacting with the functionalized diene elastomer E2 and a crosslinking system, in which: - the glass transition temperature TgE1 is above or equal to -50°C, - the glass transition temperature TgE2 satisfies the mathematical relationship TgE2 ≤ TgE1-23°C, and - the content of the non-functionalized diene elastomer E1 is within a range extending from 50 phr to 70 phr, and the glass transition temperatures TgE1 and TgE2 are determined using a differential calorimeter according to ASTM D3418:2008.

2. Rubber composition according to Claim 1, in which the glass transition temperature TgE2 satisfies the mathematical relationship TgE2 ≤ TgE1-28°C, more preferentially TgE2 ≤ TgEl-30°C.

3. Rubber composition according to either one of the preceding claims, in which the glass transition temperature TgE2 satisfies the mathematical relationship TgE2 ≥ TgE1-65°C, more preferentially TgE2 ≥ TgEl-50°C, more preferentially still TgE2 ≥ TgE1-45°C.

4. Rubber composition according to any one of the preceding claims, in which the glass transition temperature TgE2 is within a range extending from -110°C to -23°C, preferably extending from -100°C to -28°C, more preferentially extending from -95°C to -30°C.

5. Rubber composition according to any one of the preceding claims, in which the functionalized diene elastomer E2 is selected from the group consisting of natural rubber, synthetic polyisoprenes, polybutadienes, isobutene / isoprene copolymers, butadiene / styrene copolymers, butadiene / isoprene copolymers, isoprene / styrene copolymers and butadiene / styrene / isoprene copolymers.

6. Rubber composition according to any one of the preceding claims, in which the functionalized diene elastomer E2 is selected from polybutadienes and butadiene / styrene copolymers.

7. Rubber composition according to any one of the preceding claims, in which the functionalized diene elastomer E2 comprises at least one chemical function capable of interacting with the reinforcing filler, the chemical function comprising at least one heteroatom selected from the group consisting of nitrogen, sulfur, oxygen, phosphorus, tin and silicon; preferably the chemical function capable of interacting with the reinforcing filler is a polar function comprising at least one oxygen atom.

8. Rubber composition according to any one of the preceding claims, in which the glass transition temperature TgE1 is within a range extending from -50°C to 0°C, more preferentially from -40°C to 0°C, more preferentially from -30°C to 0°C.

9. Rubber composition according to any one of the preceding claims, in which the content of the diene elastomer E1 is within a range extending from 55 phr to 70 phr, more preferentially from 55 phr to 65 phr.

10. Rubber composition according to any one of the preceding claims, in which the non-functionalized diene elastomer E1 is selected from the group consisting of synthetic polyisoprenes, polybutadienes, butadiene / styrene copolymers, butadiene / isoprene copolymers, isoprene / styrene copolymers and butadiene / styrene / isoprene copolymers.

11. Rubber composition according to any one of the preceding claims, in which the non-functionalized diene elastomer E1 is selected from polybutadienes and styrene / butadiene copolymers.

12. Rubber composition according to any one of the preceding claims, in which the content of the reinforcing filler is within a range extending from 20 to 100 phr, preferably extending from 30 to 90 phr, more preferentially still extending from 40 to 90 phr.

13. Rubber composition according to any one of the preceding claims, in which the reinforcing filler predominantly comprises at least one inorganic reinforcing filler, more preferentially still predominantly comprises at least one silica.

14. Rubber composition according to any one of the preceding claims, in which the content of the functionalized diene elastomer E2 is within a range extending from 30 phr to 50 phr, preferably from 30 phr to 45 phr, more preferentially from 35 phr to 45 phr.

15. Tread comprising at least one composition defined according to any one of Claims 1 to 14.

16. Pneumatic or non-pneumatic tyre comprising at least one composition defined according to any one of Claims 1 to 14 or a tread according to Claim 15.