HEAT RESISTANT STYRENE BASED RESIN EXTRUSION FOAM BOARD

摘要

PURPOSE:To obtain a foam board resistant to heat above 90 deg.C by extrusion foaming a styrene-alpha methylstyrene-acrylonitryl copolymer. CONSTITUTION:100pts.wt. of styrene-alpha methylstyrene-acrylonitryl copolymer produced by polymerizing 100pts.wt. of styrene with 60-700pts.wt. of alpha methylstyrene and 40-400pts.wt. of acrylonitryl is extrusion foamed in the presence of 2-30pts.wt. of a volatile foaming agent. The thermal deformation start temperature of the styrene-alpha methylstyrene-acrylonitryl copolymer is most preferably in the range of 92-110 deg.C in a method prescribed by ASTM-D-648 (with a load of 18.6kg). Thus, an excellent heat resistant styrene-based resin extrusion foam board having a uniform fine cell structure can be obtained without impairing the heat resistance of the styrene-alpha methyl-styrene-acrylonitryl copolymer.