Rubber composition and pneumatic tire with low zinc content

摘要

The present invention is directed to a rubber composition comprising
a solution polymerized styrene-butadiene rubber having a bound styrene content of at least 36 percent by weight and a vinyl 1,2 content of less than 25 percent by weight;
optionally, at least one additional diene based rubber;
silica;
a sulfur donor;
a sulfenamide accelerator;
at least one secondary accelerator selected from the group consisting of guanidines, dithiocarbamates and thiurams; and
an ±,É-bis(N,N'-dihydrocarbylthiocarbamamoyldithio)alkane;
wherein the zinc content of the rubber composition is less than 0.5 parts by weight, per 100 parts by weight of elastomer (phr) as Zn metal. The invention is also directed to a tire comprising this rubber composition.