| 摘要 |
PURPOSE:To attempt to improve luster, rigidity, the appearance of a molded item, impact strength, etc., by polymerizing a styrenic monomer and an acrylonitrile monomer in the presence of a specified rubbery polymer. CONSTITUTION:In the presence of a rubbery polymer (A) which is a block copolymer with a styrene content of 2-30wt.% consisting of 50wt.% or more both of a polymer block (BDB) wherein at least one kind of butadiene is the main component and a polymer block (STB) wherein at least one kind of styrene is the main component, has a branched structure of the formula (wherein m is 3-6; P is a residue of a polyfunctional coupling agent), contains a styrene- insoluble component at 25 deg.C of 0.5wt.% or lower and has a viscosity of a 5wt.% soln. in styrene of 5-50cst, a styrenic monomer (B) and an acrylonitrile monomer (C) are polymerized to obtain the title copolymer which consists of dispersed particles of the component A and a continuous phase of a copolymer of the components B and C, wherein the dispersed particles are grafted with the copolymer or occludes it and which has a copolymer-occluding or grafting index of 25-150% and an MW distribution index of the copolymer of 1.9-3.0. |
