| 摘要 |
PURPOSE:To obtain a sheet having excellent heat resistance and moldability and suitable for packaging container for a chilled food, etc., reduced in odor by blending a specific polyphenylene ether and polystyrene with a foaming agent under high-temperature pressure and extruding the blend into a low- pressure zone. CONSTITUTION:A mixed resin of 40-90 pts.wt. polyphenylene ether suppressed to <=5ppm is toluene amount in volatile component and 10-60 pts.wt. polystyrene is blended with a foaming agent at high temperature under high pressure and the blend is extruded into a low pressure zone. A copolymer of polyphenylene ether suppressed to 5ppm in toluene amount and styrene may be used instead of the mixed resin. Toluene amount in the volatile component is preferably kept to <=3ppm. A hydrocarbon based foaming agent consisting essentially of dichlorodifluoromethane and iso-butane is preferably used as the foaming agent. |
