Michelin Recherche Et Technique S.a.

Compagnie Generale Des Etablissements Michelin

Francois Harle

Lucien Bondu

Olivier Goncalves

Cecile Belin

A tire with a radial carcass reinforcement, having a crown reinforcement, itself capped radially by a tread connected to two beads by two sidewalls, the tread having at least two layers of blended elastomeric compounds that are radially superposed and have a voids ratio that is lower in the central part than at the axially outer parts. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a part extending at least into the region of the equatorial plane and of at least two axially outer parts formed of a second blended elastomeric compound, the first blended elastomeric compound having a macro dispersion Z-value higher than 65 and a maximum tan(&#x3b4;) value, denoted tan(&#x3b4;)max, lower than 0.120, and the complex dynamic shear modulus G* 1% at 100&#xb0; C. of the second blended elastomeric compound having a value at least 10% higher than that of the complex dynamic shear modulus G* 1% at 100&#xb0; C. of the first blended elastomeric compound.

Tire comprising a tread formed by multiple elastomer blends

A tire with a radial carcass reinforcement, having a crown reinforcement, itself capped radially by a tread connected to two beads by two sidewalls, the tread containing at least two layers of blended elastomeric compounds that are radially superposed and have a voids ratio that is lower in the central part than at the axially outer parts. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a part extending at least into the region of the equatorial plane and of at least two axially outer parts formed of a second blended elastomeric compound, the first blended elastomeric compound having a macro dispersion Z-value higher than 65 and a maximum tan(&#x3b4;) value, denoted tan(&#x3b4;)max, lower than 0.150, and the elongation at break in a tearability test of the second blended elastomeric compound at 100&#xb0; C. having a value at least 10% higher than that of the elongation at break of the first blended elastomeric compound in a tearability test at 100&#xb0; C.

A tire of which the tread contains at least two layers of blended elastomeric compounds that are radially superposed and have a voids ratio that is lower in the central part than at the axially outer parts. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a part extending at least into the region of the equatorial plane and of at least two axially outer parts formed of a second blended elastomeric compound, the first blended elastomeric compound having a Z-value higher than 55 and a tan(&#x3b4;)max value lower than 0.120, the second blended elastomeric compound having a Z-value higher than 50 and a tan(&#x3b4;)max value lower than 0.100, and the complex modulus G*1% at 100&#xb0; C. of the second blended elastomeric compound having a value at least 5% higher than that of the modulus G*1% at 100&#xb0; C. of the first blended elastomeric compound.

A tire with a radial carcass reinforcement, having a crown reinforcement, itself capped radially by a tread connected to two beads by two sidewalls, the tread having at least two layers of blended elastomeric compounds that are radially superposed and have a voids ratio that is lower in the central part than at the axially outer parts. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a part extending at least into the region of the equatorial plane and of at least two axially outer parts formed of a second blended elastomeric compound, the first blended elastomeric compound having a macro dispersion Z-value higher than 65 and a maximum tan(&#x3b4;) value, denoted tan(&#x3b4;)max, lower than 0.150, and the second blended elastomeric compound having a maximum tan(&#x3b4;) value, denoted tan(&#x3b4;)max, lower than 0.130.

A tire of which the tread contains at least two layers of blended elastomeric compounds that are radially superposed and has a voids ratio that is lower in the central part than at the axially outer parts thereof. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a central part, and of two outer parts formed of a second blended compound, the first blended compound having a Z-value higher than 55, the first blended compound and the second blended compound having a tan(&#x3b4;)max value lower than 0.110, the modulus G* of the second blended elastomeric compound having a value at least 10% higher than that of the modulus G* of the first blended elastomeric compound, a second layer of the tread, radially the outermost, being made up of a third blended compound of which the modulus G* has a value at least 10% higher than that of the modulus G* of the first blended elastomeric compound and the elongation at break of the third blended compound having a value at least 10% higher than those of the elongations at break of the first and second blended compounds.

Growing community of inventors

Clermont-Ferrand, France

Francois Harle