HEAT-RESISTANT EXPANDED SHEET OF STYRENE-BASED RESIN AND ITS FORMED PRODUCT

摘要

PROBLEM TO BE SOLVED: To obtain an expanded sheet having excellent heat resistance, rigidity and secondary formability, especially an expanded sheet suitably useful for a food container required to have sufficient heat resistance for cooking by a microwave oven and its formed product. SOLUTION: This heat-resistant expanded sheet of styrene-based resin comprises 75-90 wt.% of a styrene-methacrylic acid polymer resin and 25-10 wt.% of a styrene-butadiene copolymer resin. A heat-resistant expanded film comprises <=10 pts.wt. of a methyl methacrylate-butadiene-styrene rubber based on 100 pts.wt. of a styrene-methacrylic acid copolymer and 75-90 wt.% of total amount of a styrene-methacrylic acid copolymer resin and a methyl mechacrylate-butadiene-styrene rubber and 25-10 wt.% of a styrene-butadiene copolymer resin having >=50 wt.% butadiene rubber ratio. The formed product is composed of the heat-resistant expanded sheet of a styrene-based resin.