Abstract: The present invention relates to a tin-containing organolithium compound which can be used as anionic polymerization initiators, represented by the following formula (1):

Abstract: The present invention relates to star-block interpolymers having the following structure (X-Y)n-C, wherein X represents a random copolymer block derived from conjugated diene and monovinyl aromatic monomer; Y represents a polyconjugated diene block; C represents a residue derived from a multifunctional lithium based initiator; and n represents the functionality of the initiator and has a value of not less than 3; and preparation of the same. The star-block interpolymers according to the present invention have in the same molecule both a random copolymer block derived from conjugated diene and monovinyl aromatic monomer and a rubber block selected from the group consisting of a homopolymer block derived from conjugated diene, a tapered copolymer block derived from conjugated dienes, a random copolymer block derived from conjugated dienes and combinations thereof, and hence possess excellent properties of the both kinds of rubbers, and can be used widely as elastomeric materials.

Abstract: The present invention relates to butadiene/isoprene/monovinyl aromatic monomer heptablock copolymers having the following symmetric structure: Z-XZ-X-Y-X-XZ-Z wherein Z represents a polymer block of monovinyl aromatic monomer, X and Y, being different from each other, represent polymer blocks of butadiene or isoprene, XZ represents a tapered copolymer block of monovinyl aromatic monomer and butadiene or isoprene, and wherein the content of the recurring units derived from monovinyl aromatic monomer is 10 to 50 percent by weight, the content of the recurring units derived from butadiene is 10-75 percent by weight and the content of the recurring units derived from isoprene is 10-75 percent by weight, all based on the weight of the block copolymer, and methods for the preparation thereof.