Abstract: By block-copolymerizing a mixture of an aromatic vinyl compound and a conjugated diene in two stages in an aliphatic hydrocarbon solvent, using an organomonolithium compound or an organodilithium compound as a polymerization initiator, a block copolymer is formed as a suspension polymer in a slurry state.The resulting block copolymer is very clear and excellent in mechanical properties, especially, strength, elongation and impact strength. It has a wide application in the field of general resins.

Abstract: A new modified elastomer having a phenolic hydroxyl group on the side chain, which is excellent in physical properties, crosslinkability, thermal stability, tackiness, adhesiveness and compatibility, is obtained by copolymerizing at least one monomer selected from the group consisting of conjugated dienes, and mono-ethylenically unsaturated monomers, or graft-copolymerizing an elastomer prepared by polymerizing at least one monomer defined above, with a phenolic monomer represented by the general formula, ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are individually an alkyl group or a hydrogen atom.

Abstract: By block-copolymerizing a vinyl aromatic compound and a conjugated diene in a hydrocarbon solvent with an organolithium compound as initiator, there is obtained a block copolymer which comprises in the molecule three blocks of homopolymerized vinyl aromatic compound, randomly copolymerized vinyl aromatic compound and conjugated diene, and homopolymerized diene, respectively. The resulting block copolymer is transparent and excellent in mechanical properties, and is suitable for use in the manufacture of sheeting, film, and various molded articles.

Abstract: In block-copolymerizing a vinyl aromatic compound and a conjugated diene in a hydrocarbon solvent using an organolithium compound as initiator, a transparent block copolymer resin characterized by having elastomeric random copolymer blocks may be produced by continuously adding a mixture of the vinyl aromatic compound and the conjugated diene. The block copolymer resin thus obtained is transparent, excellent in mechanical characteristics and may be used in the fields of sheetings, films, and various molded articles.

Abstract: An aromatic vinyl compound and a conjugated diene are block-copolymerized in a hydrocarbon solvent using an organolithium compound as an initiator to form a hydrocarbon solution of a block copolymer resin which is then steam-stripped off the solvent in the presence of a specified block polyether type dispersing agent to yield a granular polymer. The block copolymer thus obtained has favorable properties as granules and can be fabricated into articles being highly transparent and having excellent mechanical properties.

Abstract: A block copolymer resin having at one or both ends a copolymer block of a vinyl aromatic compound and a conjugated diene is obtained by subjecting a vinyl aromatic compound and a conjugated diene to 2- or 3-stage block copolymerization in a hydrocarbon solvent in the presence of a definite amount of a Lewis base compound using an organolithium compound as an initiator. The block copolymer resin is high in transparency and excellent in mechanical properties, and is successfully usable in the fields of sheets, films and various molded articles.

Abstract: A new modified elastomer having a phenolic hydroxyl group on the side chain, which is excellent in physical properties, crosslinkability, thermal stability, tackiness, adhesiveness and compatibility, is obtained by copolymerizing at least one monomer selected from the group consisting of conjugated dienes, and monoethylenically unsaturated monomers, or graft-copolymerizing an elastomer prepared by polymerizing at least one monomer defined above, with a phenolic monomer represented by the general formula, ##SPC1##Wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are individually an alkyl group or a hydrogen atom.