Abstract: The invention relates to the preparation of a rubber composition containing a pre-treated precipitated silica and a tire having a component comprised of such rubber composition. The pre-treated silica is a precipitated silica having been pre-treated with a silica coupling agent comprised of an alkoxyorganomercaptosilane to form a precipitated silica/coupling agent composite prior to its blending with a rubber composition. The rubber composition preparation involves reacting said pretreated silica/coupling agent composite with a combination of bis(3-triethoxysilylpropyl) polysulfides in situ within the rubber composition.

Abstract: The present invention is directed to a rubber composition comprising at least one diene based elastomer; an ?,?-bis(N,N?-dihydrocarbylthiocarbamamoyldithio)alkane; and sulfur in a form selected from the group consisting of elemental sulfur and insoluble sulfur; wherein the rubber composition is essentially free of cure accelerators. The invention is further directed to a pneumatic tire comprising the rubber composition.

Abstract: The invention relates to the preparation of a rubber composition containing a pre-treated precipitated silica and a tire having a component comprised of such rubber composition. The pre-treated silica is a precipitated silica having been pre-treated with a silica coupling agent comprised of an alkoxyorganomercaptosilane to form a precipitated silica/coupling agent composite prior to its blending with a rubber composition. The rubber composition preparation involves reacting said pretreated silica/coupling agent composite with a combination of bis(3-triethoxysilylpropyl)polysulfides in situ within the rubber composition.