The present invention relates to multiblock interpolymers having the
following symmetric structures and processes for their preparation: Y-X-Y,
wherein Y represents a block of a random copolymer of conjugated diene and
monovinyl aromatic monomer; and X represents a block of butadiene
homopolymer, a block of isoprene homopolymer, or a block of
butadiene/isoprene copolymer, and processes for the preparation thereof.
The present multiblock interpolymers have in the same molecule both a
rubber block of random copolymer of conjugated diene and monovinyl
aromatic monomer and a rubber block selected from blocks of butadiene
homopolymer, isoprene homopolymer and butadiene/isoprene copolymers, and
hence possess excellent properties of the both two kinds of rubbers, and
can be used widely as integrated rubber materials with excellent property
balance, the present processes can simply prepare the above integrated
rubber material in situ in a single reactor.
