| 摘要 |
PURPOSE:To obtain the titled resin having excellent both Izod impact strength and rigidity, by adding a specific styrene-butadiene block copolymer as a toughening agent in polymerizing styrene, etc. CONSTITUTION:A styrene based monomer is polymerized in the presence of normally 2-20wt.% styrene-butadiene block copolymer, having 15-35wt.% styrene content, 15-35mol% 1,2-vinyl bond content in butadiene unit parts, <=1.5 ratio of the weight-average molecular weight/lumber-average molecular weight as well as 5-20cP viscosity (measured by using a 5wt.% styrene solution at 25 deg.C) and characterized in that random copolymerized parts of styrene units and butadiene units are not contained in the polymer chain while stirring by a bulk or bulk-suspension polymerization method to afford the aimed resin. |
