Tire with improved end-of-life grip on wet ground

Patent metadata

Field	Value
Publication number	US-2023191851-A1
Application number	US-202117924600-A
Country	US
Kind code	A1
Filing date	Apr 22, 2021
Priority date	May 13, 2020
Publication date	Jun 22, 2023
Grant date	—

Abstract

A tire (10) for a passenger vehicle comprises a tread comprising at least one regulation wear indicator (46) defining a regulation wear threshold, a tread layer (52) comprising an elastomeric tread material exhibiting a complex dynamic shear modulus G*_1 and a dynamic loss tanD0_1, and a backing layer (54) for the tread layer (52) that comprises an elastomeric backing material exhibiting a complex dynamic shear modulus G*_2 and a dynamic loss tanD0_2 such that tanD0_2≥0.37×tanD0_1 and G*2≥0.90×G*1.

First claim

1 .- 15 . (canceled)

16 . A tire ( 10 ) for a passenger vehicle, the tire comprising a tread ( 14 ) comprising cuts ( 40 ) and tread pattern blocks ( 42 ), the cuts ( 40 ) separating the tread pattern blocks ( 42 ) from one another, the tread ( 14 ) being intended to come into contact with a ground when the tire ( 10 ) is running via a tread surface ( 38 ), the tread ( 14 ) comprising at least one regulation wear indicator ( 46 ) defining a regulation wear threshold, and, in an axially central portion (P 1 ) of the tread ( 14 ) having an axial width (L 1 ) equal to at least 70% of the width (L) of the tread surface ( 38 ), the tread ( 14 ) comprises:
a tread layer ( 52 ) bearing the tread surface ( 38 ), the tread layer ( 52 ) comprising an elastomeric tread material exhibiting:
a complex dynamic shear modulus G*_1, measured at 10% strain in accordance with standard ASTM D-5992-96, at a temperature of 23° C. and a frequency of 10 Hz, and
a dynamic loss tanD0_1, measured in accordance with standard ASTM D-5992-96, at a temperature of 0° C. and a frequency of 10 Hz;
a backing layer ( 54 ) for the tread layer ( 52 ) arranged radially on an inside of the tread layer ( 52 ), the backing layer ( 54 ) comprising an elastomeric backing material exhibiting:
a complex dynamic shear modulus G*_2, measured at 10% strain in accordance with standard ASTM D-5992-96, at a temperature of 23° C. and a frequency of 10 Hz, and
a dynamic loss tanD0_2, measured in accordance with standard ASTM D-5992-96, at a temperature of 0° C. and a frequency of 10 Hz,
wherein the elastomeric tread material is different from the elastomeric backing material such that the tread layer ( 52 ) and the backing layer ( 54 ) are contiguous via an interface ( 56 ) describing an interface trajectory ( 58 ) in a meridian section plane comprising the regulation wear indicator ( 46 ), wherein tanD0_2≥0.37×tanD0_1 and G*_2≥0.90×G*_1, wherein, in the axially central portion (P 1 ) of the tread ( 14 ), by defining, in the meridian section plane, a regulation wear trajectory ( 60 ) that is parallel to the tread surface ( 38 ) of the tire ( 10 ) when new and passes through a radially outermost point ( 51 ) of the regulation wear indicator ( 46 ), at least 75% of the length (l) of the interface trajectory ( 58 ) located radially below the tread pattern blocks ( 42 ) is arranged, in the meridian section plane, radially on an inside of the regulation wear trajectory ( 60 ), and wherein, in the axially central portion (P 1 ) of the tread ( 14 ), at least 75% of the length (l) of the interface trajectory ( 58 ) located radially below the tread pattern blocks ( 42 ) is arranged, in the meridian section plane, at a mean radial distance (d 1 ) less than or equal to 2.0 mm from the regulation wear trajectory ( 60 ).

17 . The tire according to claim 16 , wherein tanD0_2≥0.5×tanD0_1.

18 . The tire ( 10 ) according to claim 16 , wherein G*_2≥0.92×G*_1.

19 . The tire ( 10 ) according to claim 16 , wherein, in the axially central portion (P 1 ) of the tread ( 14 ), at least 75% of the length (l) of the interface trajectory ( 58 ) located radially below the tread pattern blocks ( 42 ) is arranged, in the meridian section plane, radially on an outside of a trajectory ( 62 ) which is parallel to the tread surface ( 38 ) of the tire ( 10 ) when new and passes through a radially innermost point ( 48 ) of a or each deepest cut ( 44 ).

20 . The tire ( 10 ) according to claim 16 , wherein, in the axially central portion (P 1 ) of the tread ( 14 ), at least 75% of the length (l) of the interface trajectory ( 58 ) located radially below the tread pattern blocks ( 42 ) is arranged, in the meridian section plane, at a mean radial distance (d 1 ) greater than or equal to 0.4 mm from the regulation wear trajectory ( 60 ).

21 . The tire ( 10 ) according to claim 16 , wherein, in the axially central portion (P 1 ) of the tread ( 14 ), at least a non-zero length (l′) of the interface trajectory ( 58 ) located radially below the tread pattern blocks ( 42 ) is arranged, in the meridian section plane, radially on an outside of the regulation wear trajectory ( 60 ).

22 . The tire according to claim 16 , wherein tanD0_1 ranges from 0.50 to 1.00.

23 . The tire ( 10 ) according to claim 16 , wherein tanD0_2 ranges from 0.60 to 1.10.

24 . The tire ( 10 ) according to claim 16 , wherein G*_1 ranges from 1.30 MPa to 4.10 MPa.

25 . The tire ( 10 ) according to claim 16 , wherein G*_2 is greater than or equal to 2.00 MPa.

26 . The tire ( 10 ) according to claim 16 further comprising a crown ( 12 ) comprising a crown reinforcement ( 16 ) arranged radially on the inside of the tread ( 14 ),
wherein, in the axially central portion (P 1 ) of the tread ( 14 ), a mean distance (d 2 ) between a layer ( 28 ) comprising radially outermost reinforcing elements ( 280 ) of the crown reinforcement ( 16 ) and a radially innermost point ( 48 ) of a or each deepest cut ( 44 ) is less than or equal to 2.50 mm.

27 . The tire ( 10 ) according to claim 16 further comprising a crown ( 12 ) comprising a crown reinforcement ( 16 ) arranged radially on the inside of the tread ( 14 ),
wherein, in the axially central portion (P 1 ) of the tread ( 14 ), a mean distance (d 2 ) between a layer ( 28 ) comprising radially outermost reinforcing elements ( 280 ) of the crown reinforcement ( 16 ) and a radially innermost point ( 48 ) of a or each deepest cut ( 44 ) is greater than or equal to 1.0 mm.

28 . The tire ( 10 ) according to claim 16 , wherein the elastomeric tread material exhibits a dynamic loss tanDMAX23_1, measured in accordance with standard ASTM D-5992-96, at a temperature of 23° C. and a frequency of 10 Hz, ranging from 0.13 to 0.70.

29 . The tire ( 10 ) according to claim 16 , wherein the elastomeric backing material exhibits a dynamic loss tanDMAX23_2, measured in accordance with standard ASTM D-5992-96, at a temperature of 23° C. and a frequency of 10 Hz, ranging from 0.13 to 0.53.

30 . The tire ( 10 ) according to claim 16 , wherein a surface-area void ratio of the tire ( 10 ) exhibiting a tread pattern height (HS) equal to 2.0 mm after wear ranges from 20% to 35%.

Assignees

• Michelin & Cie

Inventors

• Durand-Gasselin Benoit
• Francois Marie-Laure
• Hellot Fabien

Classifications

• B60C11/0008

  characterised by the tread rubber · CPC title

• B60C11/24 Primary

  Wear-indicating arrangements · CPC title

• B60C2011/0025

  Modulus or tan delta · CPC title

• B60C2011/0033

  Thickness of the tread · CPC title

• B60C11/005 Primary

  with cap and base layers · CPC title