	US 12,215,231 B2
	Tire tread rubber composition
James P. Kleckner, Akron, OH (US); Anthony M. Unger, New Albany, OH (US); and Benjamin C. Galizio, Munroe Falls, OH (US)
Assigned to Bridgestone Americas Tire Operations, LLC, Nashville, TN (US)
Filed by Bridgestone Americas Tire Operations, LLC, Nashville, TN (US)
Filed on Jun. 10, 2021, as Appl. No. 17/344,060.
Application 17/344,060 is a continuation of application No. 17/052,721, previously published as PCT/US2019/030155, filed on May 1, 2019.
Claims priority of provisional application 62/667,064, filed on May 4, 2018.
Prior Publication US 2021/0301110 A1, Sep. 30, 2021
Int. Cl. C08L 9/06 (2006.01); B60C 1/00 (2006.01); B60C 11/00 (2006.01); C08C 19/25 (2006.01)

CPC C08L 9/06 (2013.01) [B60C 1/0016 (2013.01); B60C 11/0008 (2013.01); C08C 19/25 (2013.01); B60C 2011/0025 (2013.01); C08L 2205/03 (2013.01); C08L 2207/04 (2013.01)]

19 Claims

1. A tire tread rubber composition comprising:

a. 100 parts of an elastomer component comprising

i. 30-50 parts of solution-polymerized styrene-butadiene rubber,

ii. 30-50 parts of polybutadiene rubber having a cis bond content of at least 95% and a Tg of less than −101° C., and

iii. 20-40 parts of natural rubber consisting of guayule natural rubber,

wherein any additional diene-monomer containing rubber is present in an amount of no more than 5 parts,

b. at least one reinforcing silica filler in an amount of 81-120 phr,

c. no more than 15 phr of carbon black filler,

d. 11-35 phr of at least one hydrocarbon resin having a Tg of about 30 to about 50° C.,

e. 0-40 phr oil, and

f. a cure package,

wherein the total amount of (d) and (e) is no more than 59 phr.