Expandable polystyrene resin particles, foam molded products, processes for their preparation, pre-expanded particles

摘要

PROBLEM TO BE SOLVED: To provide foamable polystyrene-based resin particles capable of giving beautiful foamed molded articles having little clearance between fused particles and shining the colors of printed inks.;SOLUTION: This method for producing foamable polystyrene-based resin particles is characterized by impregnating a foaming agent mixture of pentane with propane into polystyrene-based resin particles, keeping the obtained foaming agent-containing resin particles in a gas phase of 30 to 65°C for 0.5 to 12 hours under a pressure of 650 to 40,000 Pa to obtain the foamable polystyrene-based resin particles comprising 100 pts.mass of the polystyrene-based resin, 3 to 9 pts.mass of the pentane and 0.01 to 0.8 pts.mass of the propane.;COPYRIGHT: (C)2008,JPO&INPIT