| 摘要 |
PURPOSE: To provide a process for producing a foamed polystyrene sheet which suffers little decrease in secondary expansion ratio, has an excellent moldability, is free from the fear of explosion, etc., even in long-term storage, and is suitable for use as a food container, etc. CONSTITUTION: Butane consisting of 70-100wt.% isobutane and 0-30wt.% n-butane is incorporated into a melt of polystyrene in an amount of 2.5-5 pts.wt. per 100 pts.wt. the polystyrene. This mixture is extruded and foamed so as to give an extrudate having a residual-butane content of 2.0-3.5wt.% based on the polystytene. |
