Process for the synthesis of styrene-isoprene rubber

摘要

The subject invention relates to a technique for synthesizing rubbery copolymers of styrene and isoprene. These rubbery copolymers exhibit an excellent combination of properties for utilization in tire tread rubber compounds. By utilizing these styrene-isoprene rubbers in tire treads, tires having improved wet skid resistance can be built without sacrificing rolling resistance or tread wear characteristics. This invention more specifically discloses a process for the synthesis of styrene-isoprene rubbers which comprises copolymerizing isoprene monomer and styrene monomer in an organic solvent in the presence of a catalyst system which is comprised of (a) a lithium initiator and (b) an alkyl tetrahydrofurfuryl ether modifier, wherein the molar ratio of the modifier to the lithitium initiator is within the range of 2:1 to 40:1. The subject invention further discloses a process for the synthesis of styrene-isoprene rubbers which comprises copolymerizing isoprene monomer and styrene monomer in an organic solvent in the presence of a catalyst system which is comprised of (a) a lithium initiator and (b) 2,2-ditetrahydrofurylpropane as a modifier, wherein the molar ratio of the modifier to the lithium initiator is within the range of 1:1 to 40:1.