RUBBER COMPOSITION COMPRISING A DIENE-BASED ELASTOMER, A BRANCHED POLYETHYLENIMINE OLIGOMER AND A REINFORCING FILLER, AND A TIRE WITH SUCH A RUBBER COMPOSITION

摘要

A method of preparing a rubber composition is disclosed. The rubber composition comprises, based on parts by weight per 100 parts by weight rubber (phr), 100 phr of at least one conjugated diene-based elastomer, 0.05 to 1 phr of branched polyethylenimine oligomer, 30 to 160 phr of reinforcing filler comprising silica or a combination of carbon black and silica, preferably precipitated silica, a silica coupler for the silica having a moiety reactive with hydroxyl groups on the silica and another different moiety interactive with the one or more diene-based elastomer(s), 0.1 to 8 phr of zinc oxide and from 0.5 to 8 phr of fatty acid, and at least one a sulfur curative and at least one sulfur vulcanization accelerator. The method comprises blending the one or more elastomer(s), the reinforcing filler, the branched polyethylenimine oligomer, the silica coupler, the zinc oxide and the fatty acid in at least two preparatory sequential mixing steps followed by a blending of the sulfur curative and the at least one sulfur vulcanization accelerator in a subsequent final mixing step. The zinc oxide and the fatty acid are blended prior to the final mixing step in a second preparatory mixing step, the second preparatory mixing step being subsequent to a first preparatory mixing step in which the polyethylenimine oligomer is blended with the one or more elastomer(s).