EXPANDABLE POLYSTYRENE RESIN PARTICLE FOR HEAT INSULATING MATERIAL TO BE USED IN HOT WATER STORAGE TANK OF HEAT PUMP SYSTEM WATER HEATER, AND HEAT INSULATING MATERIAL FOR HOT WATER TANK OF HEAT PUMP SYSTEM WATER HEATER

摘要

PROBLEM TO BE SOLVED: To provide a heat insulating material of a hot water storage tank of a heat pump system water heater, the insulating material having heat resistance exhibiting a dimensional change rate of within 0.5% when heated at 90C for 168 hours, having excellent filling property in a cavity during molding, and having a compact size and flame retardancy without degrading the heat insulating performance.;SOLUTION: The expandable polystyrene resin particles are obtained by dispersing polystyrene resin particles having a coefficient of variation (CV) of the polystyrene resin particle diameter ranging from 5 to 15% in an aqueous suspension, and subsequently, before or during infiltrating a blowing agent into the particles, supplying a flame retardant solution into the aqueous suspension, the flame retardant solution prepared by dissolving 33 to 1,000 pts.wt. of a powdery flame retardant tetrabromocyclooctane with respect to 100 pts.wt. of a plasticizer, and 20 to 200 pts.wt. of a flame retardant aid having a 1-hour half-life temperature of 100C to 250C with respect to 100 pts.wt. of the plasticizer, in the plasticizer, so as to infiltrate the flame retardant and the flame retardant aid into the polystyrene resin particles. A polystyrene molded foam article is obtained by preliminarily expanding the obtained resin particles, filling a mold with the preliminarily expanded particles, and expanding, wherein the average bowstring length is 50 to 350 m.;COPYRIGHT: (C)2011,JPO&INPIT