Abstract: A novel block copolymer mixture of conjugated diene (C.D.) and vinylaromatic hydrocarbon (V.H.) having a superior transparency and impact-resistance is produced by the following two step polymerizations using an organolithium compound as a catalyst and a solvent consisting mainly of an aliphatic hydrocarbon: a first step (A) of preparing a living (co)polymer of C.D. or C.D. and V.H., by polymerizing the monomer(s) in a ratio by weight of V. H. to C.D. of 0/100 to 60/40 and in an amount of 1 to 80% by weight of total monomers to be used, in the presence of said catalyst and solvent, and a second step (B) of preparing V.H. polymer or block copolymer of V.H. and C.D., by adding to said living (co)polymer, remaining monomer(s), in a ratio by weight of V.H. to C.D. of 100/0 to 65/35 and in an amount of 99 to 20% by weight of total monomers to be used, and said catalyst and solvent, and polymerizing the remaining monomer(s) to obtain a block copolymer mixture, this block copolymer mixture having a ratio of V.H.

Abstract: A graft membrane capable of ion exchange, manufactured by preparing in advance a film wherein an alkali salt or alkaline earth salt of an .alpha.-alkyl acrylate is dispersed in a hydrophilic polymer and subsequently exposing the film to an ionizing high-energy radiation or ultraviolet radiation, or preparing a film wherein a catalyst is dispersed in addition to the aforementioned alkali salt or alkaline earth salt in the hydrophilic polymer and subsequently heating the film.

Abstract: A novel block copolymer mixture of conjugated diene (C.D.) and vinylaromatic hydrocarbon (V.H.) having a superior transparency and impact-resistance is produced by the following two step polymerizations using an organolithium compound as a catalyst and a solvent consisting mainly of an aliphatic hydrocarbon:a first step (A) of preparing a living (co)polymer of C.D. or C.D. and V.H., by polymerizing the monomer(s) in a ratio by weight of V.H. to C.D. of 0/100 to 60/40 and in an amount of 1 to 80% by weight of total monomers to be used, in the presence of said catalyst and solvent, anda second step (B) of preparing V.H. polymer or block copolymer of V.H. and C.D., by adding to said living (co)polymer, remaining monomer(s), in a ratio by weight of V.H. to C.D. of 100/0 to 65/35 and in an amount of 99 to 20% by weight of total monomers to be used, and said catalyst and solvent, and polymerizing the remaining monomer(s) to obtain a block copolymer mixture,this block copolymer mixture having a ratio of V.H.

Abstract: High-impact polystyrene composition is produced by radical polymerization, e.g. bulk or bulk-suspension polymerization, of styrene having dissolved therein 2 to 20% by weight of one or more polybutadienes prepared by solution polymerization using an organic lithium compound as catalyst, said polybutadienes having (1) 1,2-vinyl content of more than 15 to 35% and cis-1,4 content of 20 to 85%, and (2) Mooney viscosity of 25 to 85, 5% styrene solution viscosity at 25.degree. C. being 50 to 200 cps and between 1.5 and 3.0 of the Mooney viscosity.

Abstract: A novel high-impact polystyrene composition superior to conventional high-impact polystyrene composition, in low temperature high-impact properties, tensile strength, processability, toughness, stiffness, etc. can be obtained by a radical polymerization of a mixture of (1) 2-20% by weight of a random copolymer having a composition of continuously and gradually reduced styrene content along the polymer chain of the copolymer which is obtained by the solution polymerization of butadiene and styrene in the presence of a lithium base catalyst and (2) 80-98% by weight of styrene, carried out in bulk polymerization manner or in a manner in which bulk and suspension polymerizations are used in series.