RUBBER MODIFIED STYRENE-BASED POLYMER RESIN COMPOSITION FOR EXTRUSION FORMING, EXTRUDED AND FOAMED SHEET OF THE SAME RESIN AND PRODUCTION OF EXTRUDED AND FOAMED SHEET OF THE SAME RESIN

摘要

PURPOSE: To provide a composition having high closed cell ratio and slight reduction in a blowing agent during storage, and capable of being readily extruded and expanded. CONSTITUTION: This rubber modified styrene-based polymer resin composition for extrusion foaming uses a rubber modified styrene-based polymer resin having <=1.3μm average particle diameter of rubber-like polymer particles, >=450,000 Z-average molecular weight of a styrene-based polymer and <=4wt.% methanol-soluble content as a resin component. The objective extruded and foamed rubber modified styrene-based polymer resin sheet is obtained by extruding and foaming the rubber modified styrene- based polymer resin composition for extrusion foaming containing a volatile blowing agent and has 0.05-0.2g/cm<3> and >=70% closed cell ratio. The objective method for producing the extruded and foamed rubber modified styrene-based polymer resin sheet comprises extruding and foaming the rubber modified styrene-based polymer resin composition containing the volatile blowing agent by using a tandem extruder consisting of a uniaxial one-stage extruder and a uniaxial two stage extruder.