Abstract: The invention relates to a tire having a rubber tread comprised of cap/base construction where the tread cap layer provides the running surface of the tread and the tread base layer underlies the tread cap layer and thereby provides a transition between the tread cap layer and the tire carcass. For this invention, the tread cap layer is comprised of a plurality of individual circumferential load-bearing zones of rubber compositions, which exhibit graduated physical properties, and which extend from the outer running surface of the tread cap layer radially inward to said tread base layer. In one aspect, the zoned rubber tread cap layer and rubber tread base layer are co-extruded together to form a unit as an integral tread rubber composite.

Abstract: The invention relates to a tire having a rubber tread comprised of cap/base construction where the tread cap layer provides the running surface of the tread and the tread base layer underlies the tread cap layer and thereby provides a transition between the tread cap layer and the tire carcass. For this invention, the tread cap layer is comprised of a plurality of individual circumferential load-bearing zones of rubber compositions, which exhibit graduated physical properties, and which extend from the outer running surface of the tread cap layer radially inward to said tread base layer. In one aspect, the zoned rubber tread cap layer and rubber tread base layer are co-extruded together to form a unit as an integral tread rubber composite.

Abstract: The invention relates to a tire having a rubber tread comprised of cap/base construction where the tread cap layer provides the running surface of the tread and the tread base layer underlies the tread cap layer and thereby provides a transition between the tread cap layer and the tire carcass. For this invention, the tread cap layer is comprised of a plurality of individual circumferential load-bearing zones of rubber compositions, which exhibit graduated physical properties, and which extend from the outer running surface of the tread cap layer radially inward to said tread base layer. In one aspect, the zoned rubber tread cap layer and rubber tread base layer are co-extruded together to form a unit as an integral tread rubber composite.

Abstract: The invention relates to preparation of silica-rich rubber compositions by a sequence of sequential mixing steps conducted in internal rubber mixer(s) with individual maximum temperature limitations. The mixing steps are comprised of at least two non-productive mixing steps followed by a productive mixing step. The non-productive mixing steps themselves are comprised of at least one preliminary non-productive mixing step followed by a final non-productive mixing step. Elastomer, silica and coupling agent are added in at least one of said preliminary non-productive mixing steps to the exclusion of said final non-productive mixing step and said productive mixing step. Sulfur and sulfur vulcanization accelerator(s) are added in said productive mixing step to the exclusion of said non-productive mixing steps. The preliminary non-productive mixing step(s) are individually conducted to a maximum mixing temperature in a range of from about 150° C.

Abstract: This invention relates to a pneumatic rubber tire having a rubber sidewall composition of a lug and groove configuration which is designed to be ground contacting. Such sidewall configuration is of a rubber composition comprised of a blend of natural rubber and cis 1,4-polybutadiene rubber which contains specified carbon black reinforcement and silica together with a coupling agent. The tire tread rubber composition differs from the rubber composition of said sidewall lug and groove configuration by being exclusive of silica and coupling agent and carbon black reinforcement exclusive of said specified carbon black.

Abstract: A method is disclosed for increasing the rate of vulcanization of a halogenated isobutylene sulfur rubber composition comprising heating said halogenated isobutylene rubber composition to a temperature ranging from 100° C. to 200° C., wherein said halogenated isobutylene rubber composition contains from 0.05 to 10 phr of sodium thiosulfate pentahydrate.

Abstract: This invention relates to a pneumatic rubber tire having a rubber sidewall composition of a lug and groove configuration which is designed to be ground contacting. Such sidewall configuration is of a rubber composition comprised of a blend of natural rubber and cis 1,4-polybutadiene rubber which contains carbon black and silica together with a coupling agent.

Abstract: A method is disclosed for increasing the rate of vulcanization of a halogenated isobutylene sulfur rubber composition comprising heating said halogenated isobutylene rubber composition to a temperature ranging from 100° C. to 200° C., wherein said halogenated isobutylene rubber composition contains from 0.05 to 10 phr of sodium thiosulfate pentahydrate.

Abstract: This invention describes the use of liquid block isoprene-butadiene copolymers of approximately 25,000 to 100,000 .sub.v molecular weight, and which comprises 10 to 90% by weight isoprene and 90 to 10% by weight butadiene. This material is added to a rubber compound that contains natural rubber, isoprene rubber, styrene butadiene rubber and butadiene rubber, or blends thereof, the sum of which is equal to or greater than 50 phr of the entire rubber content formulation. The liquid block copolymer is used at low levels, typically 1.5 phr to 15 phr. The invention also includes tires with at least one component composed of such rubber composition such as a tire tread.

Abstract: The present invention relates to a zinc salt of the formula: ##STR1## and rubber compounds containing such salts.