Continuous solution polymerization of a conjugated diene with a monovinylaromatic compound using alkoxysilicon treating agents in the first reactor means of a reactor series

Claim 1

A process for preparing a rubbery substantially random copolymer which comprises polymerizing monomers selected from at least one polymerizable conjugated diene with at least one copolymerizable monovinyl-substituted aromatic compound under solution polymerization conditions of temperature, pressure, diluent, an organolithium initiator, and at least one randomizing agent in an amount sufficient to substantially randomize the copolymerization of said conjugated diene and said monovinyl-substituted aromatic compound, wherein said polymerization process is conducted as a substantially continuous polymerization process employing at least two reactor means of which the first and optionally at least one second reactor means function as polymerization reactor means and the last as a terminating reactor means, wherein said conjugated diene, said monovinylaromatic compound, said organolithium initiator, said randomizing agent, said diluent, and at least one alkoxysilicon treating agent, are added to said first reactor means to form a polymerization mixture, wherein said polymerization of said monomers is substantially complete when said polymerization mixture enters said terminating reactor means, and said random copolymer is withdrawn as product from said last reactor means, wherein said alkoxysilicon treating agent is employed in an amount effective to substantially increase the processability of said random copolymer product.