Abstract: This invention relates to the preparation of a natural rubber-rich rubber composition and tire with tread thereof wherein a portion of the natural rubber is replaced with an inclusion of a specialized trans 1,4-styrene/butadiene copolymer rubber. The process involves preparing a pre-formed masterbatch of a first phase.

Abstract: This invention relates to a tire with a tread of a natural rubber-rich rubber composition. A partial replacement of the natural rubber in the tire tread is accomplished by an inclusion of a relatively low Mooney viscosity specialized trans 1,4-polybutadiene. The tire tread rubber composition is comprised of a blend of the specialized trans 1,4-polybutadiene polymer and cis 1,4-polyisoprene natural rubber optionally together with at least one additional diene-based elastomer in which the natural rubber remains a major portion of the elastomers in the tread rubber composition. A significant aspect of the invention is a partial replacement of natural cis 1,4-polyisoprene rubber in the tread rubber composition. The specialized trans 1,4-polybutadiene polymer has a relatively low Mooney (ML1+4), 100° C., viscosity within a range of 25 to 55.

Abstract: This invention relates to an expandable curing bladder of a butyl rubber composition containing a micro-encapsulated polysiloxane lubricant for delivering lubricity to the surface of the bladder. The invention further relates to a process of curing tires with such bladder.