| 摘要 |
PROBLEM TO BE SOLVED: To provide expandable styrene resin particles that gives molded articles of high strength and has excellent foaming property, expandable beads, and foamed articles. SOLUTION: In the suspension polymerization of styrene monomers, the styrene monomers are added, as the concentration of oxygen in a reaction vessel is kept at less than 7 vol.%, when the rate of polymerization is more than 60%, so that they may be adsorbed to the styrene resin particles on the way of polymerization to proceed the polymerization and the formed polystyrene particles are impregnated with a foaming agent before or after the completion of the polymerization reaction. By the application of this production method, the weight average molecular weight of the surface part 1 forming 1/5 from the surface, when a particle of this polymer is equally divided into five pieces from the surface toward the innermost, can be increased. In addition, the inclination of the correlation equation between the log (R.M.S radius) and log (MW) can be kept at or less than 0.53, when the surface part 1 is measured according to the GPC/MALLS method. COPYRIGHT: (C)2007,JPO&INPIT
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