Tire comprising a tread formed by multiple elastomer blends

Patent metadata

Field	Value
Publication number	US-9713942-B2
Application number	US-201314412364-A
Country	US
Kind code	B2
Filing date	Jun 27, 2013
Priority date	Jul 5, 2012
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

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(δ) value, denoted tan(δ)max, lower than 0.150, and the second blended elastomeric compound having a maximum tan(δ) value, denoted tan(δ)max, lower than 0.130.

First claim

The invention claimed is:

1. A tire with a radial carcass reinforcement, comprising:
a crown reinforcement,
itself capped radially by a tread radially capping the crown reinforcement and connected to two beads by two sidewalls, the tread comprising at least two layers of blended elastomeric compounds that are radially superposed and have a voids ratio that is lower in a central part than at axially outer parts, wherein 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, wherein the first blended elastomeric compound has a macro dispersion Z-value higher than 65 and a maximum tan(δ) value, denoted tan(δ)max, lower than 0.150 at 100° C., and wherein the second blended elastomeric compound has a maximum tan(δ) value, denoted tan(δ)max, lower than 0.130 at 100° C.

2. The tire according to claim 1 , wherein the first blended elastomeric compound contains, by way of reinforcing filler, at least carbon black used at a content of between 10 and 70 phr, and wherein the carbon black has a BET specific surface area higher than 140 m 2 /g.

3. The tire according to claim 1 , wherein the first blended elastomeric compound contains, by way of a cut of carbon black, with a BET specific surface area higher than 140 m 2 /g, and of a white filler, wherein the reinforcing filler is used at a content of between 10 and 90 phr, and wherein the ratio of carbon black to white filler is higher than 2.7.

4. The tire according to claim 1 , wherein the complex dynamic shear modulus G*1% at 100° C. of the first blended elastomeric compound is higher than 2.30 MPa.

5. The tire according to claim 1 , wherein the first layer of blended elastomeric compound, made up of a first blended elastomeric compound forming a part that extends at least into the region of the equatorial plane and of at least two axially outer parts formed of a second blended elastomeric compound, forms the radially outer layer of the tread.

6. The tire according to claim 5 , wherein the at least two layers of blended elastomeric compounds includes a radially inner second layer in contact with the first layer, the radially inner second layer made up of a blended elastomeric compound having a maximum tan(δ) value, denoted tan(δ)max, lower than 0.130 at 100° C.

7. The tire according to claim 1 , wherein the at least two layers of blended elastomeric compounds includes a radially outer second layer in contact with the first layer, forming the radially outer layer of the tread, the radially outer second layer made up of a blended elastomeric compound having a macro dispersion Z-value higher than 65 and a maximum tan(δ) value, denoted tan(δ)max, lower than 0.150 at 100° C.

8. The tire according to claim 7 , wherein the tread comprises a radially inner third layer in contact with the said first layer, and wherein the blended elastomeric compound that makes up the said third layer has a maximum tan(δ) value, denoted tan(δ)max, lower than 0.130 at 100° C.

9. The tire according to claim 7 , wherein the tire is of a dimension less than or equal to 57 inches, wherein the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the second layer of blended elastomeric compound is greater than 50% of the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the first layer of blended elastomeric compound.

10. The tire according to claim 8 , wherein the tire is of a dimension less than or equal to 57 inches, wherein the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the third layer of blended elastomeric compound is greater than 25% of the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the first layer of blended elastomeric compound.

11. The tire according to claim 7 , wherein the tire is of a dimension strictly greater than 57 inches, wherein the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the second layer of blended elastomeric compound is greater than 10% of the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the first layer of blended elastomeric compound.

12. The tire according to claim 8 , wherein the tire is of a dimension strictly greater than 57 inches, wherein the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the third layer of blended elastomeric compound is greater than 35% of the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the first layer of blended elastomeric compound.

13. The tire according to claim 1 , wherein the tire further comprises an additional layer of a blended elastomeric compound in a radially innermost position of the tread, and wherein the blended elastomeric compound of the said additional layer has a maximum tan(δ) value, denoted tan(δ)max, lower than 0.100 at 100° C.

14. The tire according to claim 8 , wherein the tire is of a dimension less than or equal to 57 inches, wherein the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the second layer of blended elastomeric compound is greater than 50% of the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the first layer of blended elastomeric compound.

15. The tire according to claim 8 , wherein the tire is of a dimension strictly greater than 57 inches, wherein the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer, of the second layer of blended elastomeric compound is greater than 10% of the thickness, measured in the radial direction at the end of what in a meridian section of the tire is the radially outermost working layer.

Assignees

• Michelin & Cie
• Michelin Rech Tech

Inventors

• Bondu Lucien
• Harle Francois
• Goncalves Olivier
• Belin Cecile

Classifications

• B60C2011/0016

  Physical properties or dimensions · CPC title

• B60C11/033 Primary

  by the void or net-to-gross ratios of the patterns · CPC title

• B60C11/0075

  with different base rubber layers in the axial direction · CPC title

• B60C2011/0025

  Modulus or tan delta · CPC title

• B60C11/0058 Primary

  with different cap rubber layers in the axial direction · CPC title