摘要 |
PROBLEM TO BE SOLVED: To provide a method with which a polylactic acid-based resin is foamed in a high expansion ratio by extrusion foaming without lowering biodegradability of the resin and high-quality polylactic acid-based resin foam is readily produced. SOLUTION: A polylactic acid-based resin in which 2-10% of one of D-lactic acid and L-lactic acid and 98-90% of the other are copolymerized and which has 110-170°C melting point is selected, melted in an extruder, mixed with a blowing agent and subjected to extrusion foaming from the extruder at a temperature between the melting point of the resin and a temperature lower than the melting point by 40°C. COPYRIGHT: (C)2003,JPO |