| 摘要 |
PURPOSE: To provide a method for continuously producing a foamed polypropylene resin which has a high expansion ratio, good mechanical properties including heat resistance, thermal insulation, rigidity, and impact resistance, and a smooth skin layer on the surface, and further provide a plate-shaped foamed polypropylene resin having these properties. CONSTITUTION: The temperature of an expandable molten polypropylene resin containing a foaming agent is adjusted to be lower by 0-25 deg.C than the melting point of the polypropylene resin in an extruder, the molten resin is extruded from the nozzle of the extruder under high pressure, the extruded resin which is plasticized in a foaming process is molded in a molding mold in which the temperature of the surface of a resin passage is adjusted at the crystallization temperature of the polypropylene resin or lower. |
