Abstract: In a tire having a tread with cap/base construction, a regulated amount of partially crosslinked natural rubber in a tire tread compound increases the uncured ("green") stiffness, tensile strength and tear resistance of a green compound used for the base without adversely affecting physical properties of the tread after it is cured. Such green stiffness is particularly useful in the construction of a tread for a pneumatic tire, which tread is of cap/base construction because stiffness provides requisite dimensional stability of both cap and base (in the tread) during the curing of the tire. The amount of partially crosslinked natural rubber used in a tread compound depends upon the extent of crosslinking in the natural rubber, the non-crosslinked remainder being virgin latex.

Abstract: A method for processing an elastomer comprising mixing 100 parts by weight of an elastomer having olefinic unsaturation with from 0.05 to 10 phr of a hydrated zinc-sodium thiosulfate. The hydrated zinc-sodium thiosulfate may be used in place of in whole or in part for conventional adhesion promoting cobalt compounds.

Abstract: This invention relates to the discovery that esters of aminobenzoic acid, when used as a replacement in whole or in part of conventional cobalt materials, maintains the rubber-to-wire adhesion properties.

Abstract: The present invention relates to a silica-filled rubber composition reinforced with a combination of silica and a mixture of two defined carbon blacks and to pneumatic tires having treads comprised of such rubber composition.

Abstract: This invention relates to the discovery that aminobenzylamine, when used as a replacement in whole or in part of conventional cobalt materials, improves the rubber-to-wire adhesion properties.

Abstract: The present invention relates to a rubber composition reinforced with a combination of silica and defined carbon black and to pneumatic tires having treads comprised of such rubber composition. The reinforced rubber composition comprises in one aspect, at least one elastomer, defined carbon black, precipitated silica and at least one silica coupling agent.

Abstract: The present invention relates to a heterogeneous silica/carbon black-filled rubber compound and a process for making the same. The rubber compound is characterized by containing silica, two different carbon blacks and two different rubbers. One of the carbon blacks is selectively dispersed in one rubber along with the silica and the other carbon black is dispersed in another rubber. The two rubber compounds are then mixed to form a heterogeneous rubber compound.