| abstract |
The invention relates to a pneumatic tire comprising a carcass and a tread located radially outward of the carcass and extending between the tire sidewalls; the tread providing a radially outermost tread running surface; the tread comprising a first tread layer comprising a first rubber compound and a second tread layer comprising a second rubber compound; wherein the second tread layer is located radially adjacent to the first tread layer; wherein the first rubber compound is compositionally distinct from the second rubber compound; wherein the second tread layer comprises one or more integrally formed extensions of the second tread layer extending radially outwardly toward the tread running surface; wherein each of the integrally formed extensions of the second tread layer comprises a circumferentially continuous groove and a reinforcement zone disposed on a side of the groove; wherein the first rubber compound comprises 100 parts by weight of at least one diene based elastomer, and from 1 to 150 phr of silica; and the second rubber compound comprises a diene base elastomer, from 50 to 120 phr of a filler, wherein at least 20 phr of the filler is a high surface area carbon black having an iodine adsorption number of at least 100 g/kg, from 1 to 45 phr of a methylene acceptor, from 1 to 25 phr of a methylene donor, and from 1 to 30 phr of at least one additive selected from the group consisting of carbamic resins, liquid diene based polymers having a number average molecular weight ranging from 1000 to 25000, and aromatic hydrocarbon resins. |