Pneumatic tire
The present invention is directed to a pneumatic tire having a tread comprising a vulcanizable rubber composition comprising, based on 100 parts by weight of elastomer (phr), (A) from about 50 to about 90 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) ranging from −65° C. to −55° C. and functionalized with an alkoxysilane group and at least one functional group selected from the group consisting of primary amines and thiols; (B) from about 50 to about 10 phr of polybutadiene having a cis 1,4 content greater than 95 percent and a Tg ranging from −80 to −110° C.; (C) from 30 to 80 phr of a combination of a resin having a Tg of at least 30° C. and an oil, wherein the weight ratio of resin to oil is greater than 1.
1. A pneumatic tire having a tread comprising a vulcanizable rubber composition comprising, based on 100 parts by weight of elastomer (phr),
(A) from about 50 to about 90 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (T g ) ranging from −65° C. to −60° C. and functionalized primary amines and thiols, wherein the solution polymerized styrene-butadiene rubber is functionalized with an alkoxysilane groups and a thiol, comprises the reaction product of a living anionic polymer and a silane-sulfide represented by the formula
(R 4 O) x R 4 y Si—R 5 —S—SiR 4 3
wherein Si is silicon; S is sulfur; O is oxygen; x is an integer selected from 1, 2 and 3; y is an integer selected from 0, 1, and 2; x+y=3; R 4 is the same or different and is (C 1 -C 16 ) alkyl; and R 5 is aryl, and alkyl aryl, or (C 1 -C 16 ) alkyl;
(B) from about 50 to about 10 phr of polybutadiene having a cis 1,4 content greater than 95 percent and a T g ranging from −80 to −110° C.;
(C) from 30 to 80 phr of a combination of a resin having a T g of from 30° C. to 80° C. and an oil, wherein the weight ratio of resin to oil is greater than 6, wherein the amount of oil ranged from 5 to 15 phr, and the amount of resin ranges from 45 to 70 phr, wherein the resin is derived from styrene and alphamethylstyrene; and
(D) from about 70 to about 160 phr of silica.