| abstract |
The present invention relates to a process for the dispersion copolymerization of 35 to 70% by weight of vinyl substituted aromatic monomer and 30 to 65% by weight of conjugated diene monomer comprising carrying out the copolymerization in a reaction mixture containing a liquid aliphatic hydrocarbon dispersing medium, an anionic catalyst system, and an "A" block of a copolymer dispersing agent, the dispersing agent having at least two polymer blocks wherein at least one of the polymer blocks is soluble in the dispersing medium and at least another of the polymer blocks is insoluble in the dispersing medium and is formed in situ. |