| 摘要 |
PURPOSE:The titled foamed sheet free of a draw down phenomenon and having excellent formability and heat resistance and a certain range of density and content of a residual foaming agent, obtained by extrusion-foaming of a specified poly-p-methylstyrene, a foaming agent, etc. CONSTITUTION:100pts.wt. poly-p-methylstyrene with an MFR of 0.1-20g/10min, 1-20pts.wt. foaming agent (e.g. butane), 0.005-1pt.wt. bubble modifier (e.g. an equimolar mixture of citric acid and NaHCO3) and, if necessary, a heat stabilizer, an antioxidant, a colorant, etc. are heated and mixed in an extruder, and extruded at 120-180 deg.C to cause to foam, thus obtaining the titled foamed sheet having a density of 0.03-0.5g/cm<3>, a content of the residual foaming agent of 0.5-15wt%, and a thickness of 1-5mm.. |
