TIRE WITH LOW ROLLING RESISTANCE
A tire tread comprises a rubber composition based on at least: an elastomer matrix comprising more than 50% by weight of a solution SBR bearing a silanol function and an amine function, a reinforcing filler present at a content of between 40 and 80 phr, which reinforcing filler comprises between 40 and 80 phr of a silica, a coupling agent for coupling the silica to the solution SBR, 10 to 50 phr of a hydrocarbon-based resin having a Tg of greater than 20° C., and 0 to less than 5 phr of a liquid plasticizer. Such a tire has a good performance compromise between rolling resistance and wet grip.
1 .- 12 . (canceled)
13 . A tire comprising a tread which comprises a rubber composition based on at least:
an elastomer matrix comprising more than 50% by weight of a solution SBR bearing a silanol function and an amine function,
a reinforcing filler present at a content of between 40 and 80 phr, which reinforcing filler comprises between 40 and 80 phr of a silica,
a coupling agent for coupling the silica to the solution SBR,
10 to 50 phr of a hydrocarbon-based resin having a Tg of greater than 20° C., and
0 to less than 5 phr of a liquid plasticizer.
14 . The tire according to claim 13 , wherein the silanol function and the amine function are located away from the chain ends of the solution SBR.
15 . The tire according to claim 13 , wherein the amine function is a tertiary amine function.
16 . The tire according to claim 13 , wherein the solution SBR has a glass transition temperature of less than −40° C.
17 . The tire according to claim 16 , wherein the solution SBR has a glass transition temperature of between −70° C. and −40° C.
18 . The tire according to claim 13 , wherein the elastomer matrix comprises more than 75% by weight of solution SBR.
19 . The tire according to claim 18 , wherein the elastomer matrix comprises more than 85% by weight of solution SBR.
20 . The tire according to claim 13 , wherein the hydrocarbon-based resin is a terpene resin or a C5 fraction/C9 fraction copolymer.
21 . The tire according to claim 13 , wherein the content of silica ranges from 50 to 70 phr.
22 . The tire according to claim 21 , wherein the content of hydrocarbon-based resin ranges from 20 to 40 phr.
23 . The tire according to claim 21 , wherein the content of reinforcing filler varies between 50 phr and 75 phr.
24 . The tire according to claim 13 , wherein the reinforcing filler comprises a carbon black at a content of less than 10 phr.
25 . The tire according to claim 24 , wherein the reinforcing filler comprises a carbon black at a content of at most 5 phr.
26 . A process for preparing a tire according to claim 13 comprising the steps of:
thermomechanically kneading the elastomer matrix, the reinforcing filler, the coupling agent and the hydrocarbon-based resin until a maximum temperature of between 110° C. and 190° C. is reached thereby forming a combined mixture;
cooling the combined mixture to a temperature of less than 100° C.;
subsequently incorporating a crosslinking system;
kneading the combined mixture and the crosslinking system up to a maximum temperature of less than 110° C. thereby forming a composition; and
calendering or extruding the composition.