Tire with component comprised of rubber composite of styrene/butadiene elastomer containing pendent silanol and/or siloxy groups

摘要

The invention relates to a tire having at least one component (e.g. tread) of a rubber composition comprised of a styrene/butadiene elastomer composite comprised of a styrene/butadiene elastomer and a functionalized styrene/butadiene elastomer containing an internal silicon atom therein as a part of the elastomer, and at least one pendent silanol group and/or siloxy group from said silicon atom. Said elastomer composite is comprised of a significant polymodal (e.g. bimodal) molecular weight distribution between said styrene/butadiene elastomer and said functionalized styrene/butadiene elastomer. Said rubber composition contains synthetic, precipitated silica aggregates having hydroxyl groups on their surface which may be pre-treated (hydrophobated) to reduce hydroxyl groups contained on their surface prior to blending with said styrene/butadiene composite. Said rubber composition may contain a dispersion therein of a silica/plasticizer composite. Said rubber composition may be prepared by blending two bis(3-triethoxysilylpropyl) polysulfide coupling agents therewith, namely blending such polysulfide having an average of from 2 to 2.5 connecting sulfur atoms in its polysulfidic bridge in a non-productive mixing stage in the absence of addition of free sulfur and subsequently blending such polysulfide having an average of from 3.5 to 4 connecting sulfur atoms in its polysulfidic bridge in a productive mixing stage in combination with addition of free sulfur.