US 11,724,545 B2
Tire comprising a tread
Tomoya Sakurada, Tokyo (JP); and Tomotake Uchida, Tokyo (JP)
Assigned to COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, Clermont-Ferrand (FR)
Appl. No. 16/617,924
Filed by COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, Clermont-Ferrand (FR)
PCT Filed May 31, 2018, PCT No. PCT/JP2018/020874
§ 371(c)(1), (2) Date Nov. 27, 2019,
PCT Pub. No. WO2018/221630, PCT Pub. Date Dec. 6, 2018.
Claims priority of application No. PCT/JP2017/020181 (WO), filed on May 31, 2017.
Prior Publication US 2020/0101795 A1, Apr. 2, 2020
Int. Cl. B60C 11/00 (2006.01); B60C 1/00 (2006.01); C08L 9/06 (2006.01)
CPC B60C 11/0058 (2013.01) [B60C 1/0016 (2013.01); B60C 11/0008 (2013.01); C08L 9/06 (2013.01); B60C 2011/0025 (2013.01); C08L 2205/025 (2013.01); C08L 2205/03 (2013.01)] 20 Claims
 
1. 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, and a radially internal portion being made of a second rubber composition which is different from the first rubber composition,
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, and
the external portion of the tread pattern elements being at least partially covered on at least one of the lateral face with a layer of a third rubber composition which is different from the first rubber composition and the second rubber composition,
wherein the first rubber composition is based on at least:
an elastomer matrix;
a reinforcing filler; and
a plasticizing agent;
wherein the second rubber composition is based on at least:
an elastomer matrix;
a reinforcing filler; and
a plasticizing agent comprising 5 to 100 phr of a liquid plasticizer exhibiting a glass transition temperature of less than −70° C., wherein the liquid plasticizer is a liquid phosphate plasticizer or the liquid plasticizer is the liquid phosphate plasticizer and at most 50 phr of a liquid plasticizer other than the liquid phosphate plasticizer; and
wherein the third rubber composition is based on at least:
an elastomer matrix;
a reinforcing filler; and
a plasticizing agent comprising 5 to 100 phr of a hydrocarbon resin exhibiting a glass transition temperature of more than 20° C.;
wherein the glass transition temperature of the first rubber composition (FC) on a maximum tan δ when subjected to an alternating maximum stress of 0.70 MPa at a frequency of 10 Hz is higher than that of the second rubber composition (SC) and is lower than that of the third rubber composition (TC).