| 摘要 |
PROBLEM TO BE SOLVED: To provide foamable styrenic resin particles having excellent foamability and giving foamed molded articles having good mechanical strengths and good appearances without deteriorating productivity, in spite of an extremely small styrenic monomer content. SOLUTION: The foamable styrenic resin particles are characterized by having a weight-average mol.wt. Mw of≥200,000 and <320,000, a weight-average mol.wt. Mw/number-average mol.wt. Mn ratio Mw/Mn of≥2.2 and <2.9, and a styrenic monomer content of <1,000 ppm. The foamable styrenic resin particles are efficiently produced by a suspension polymerization method comprising keeping polymerization temperature at≥80°C and <100°C, when polymerization conversion is <60%, starting to rise the polymerization temperature to≥100°C and <130°C, when the polymerization conversion is≥60% and <85%, and then keeping the polymerization temperature at≥100°C and <130°C. COPYRIGHT: (C)2011,JPO&INPIT |
