Compagnie Generale Des Etablissements Michelin

Michelin Recherche Et Technique S.a.

Tomoya Sakurada

Tomotake Uchida

Gael Roty

Masahiko Moriyama

Gaël Roty

Michael Edward Dotson

A tire having a tread comprising at least three radially superposed portions which comprise a radially external portion being made of a first rubber composition, a radially intermediate portion being made of a second rubber composition and a radially internal portion being made of a third rubber composition; wherein each of the rubber compositions is based on at least an elastomer matrix, a reinforcing filler and a crosslinking system based on sulphur; wherein the amount in phr of sulphur in the first rubber composition is lower than that in the second rubber composition, and wherein the amount in phr of sulphur in the second rubber composition is higher than that in the third rubber composition.

Tire comprising a tread

A tire having a tread comprising at least two radially superposed portions which comprise a radially external portion being made of a first rubber composition (FC), and a radially internal portion being made of a second rubber composition (SC); the tread comprising a plurality of tread pattern elements () delimited by cut-outs (); the tread pattern elements () respectively comprising at least one lateral face () and a contact surface () intended to come into contact with the ground during rolling; the external portion of the tread pattern elements () being at least partially covered on at least one of the lateral face(s) () with a layer of a third rubber composition (TC).

A tire has a tread comprising a rubber composition based on at least an elastomer matrix comprising more than 50 phr and up to 100 phr of a first diene elastomer bearing at least one SiOR function, R being a hydrogen atom or a hydrocarbon radical, and optionally, 0 to less than 50 phr of a second diene elastomer which is different from the first diene elastomer; a reinforcing filler predominately comprising a reinforcing inorganic filler, wherein the content of reinforcing inorganic filler is 20 to 200 phr; and a plasticizing agent comprising 5 to 100 phr of a liquid phosphate plasticizer having a glass transition temperature of less than &#x2212;80&#xb0; C.

The tread is provided with a plurality of grooves and/or a plurality of incisions. The tread also has rubber layers laminated in a radial orientation. One rubber layer has a cap rubber layer and a base rubber layer. A modulus G* of the rubber composition constituting the base rubber layer is no more than 2 MPa at &#x2212;10&#xb0; C. with imposed shear stress of 0.25 MPa and is at least 0.7 MPa at 40&#xb0; C. with imposed shear stress of 0.70 MPa. A modulus G* of the rubber composition constituting the cap rubber layer is at least 1 MPa higher than the modulus G* of the the base rubber layer at &#x2212;10&#xb0; C. with imposed shear stress of 0.25 MPa and is less than the modulus G* of the rubber composition at 40&#xb0; C. with imposed shear stress of 0.70 MPa.

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Tokyo, Japan

Tomoya Sakurada