| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject foam, having excellent biodegradability and hydrolytic resistance, a high closed-cell ratio and a high expansion ratio by improving melting characteristics of an aliphatic polyester carbonate-based resin and specifying the density. SOLUTION: This biodegradable aliphatic polyester carbonate-based resin extruded foam is obtained by regulating the density thereof to <=0.8 g/cm<3> , preferably <=0.20 g/cm<3> , more preferably <=0.15 g/cm<3> . The resultant foam is produced by infecting a blowing agent into, e.g. an aliphatic polyester carbonate- based resin raw material having 1×10<2> to 1×10<4> Pa.s melt viscosity (at 190 deg.C and 100 sec<-1> shear rate) and >=2 mgf/Pa.s melt tension per unit viscosity while melting and kneading the aliphatic polyester carbonate-based resin raw material in an extruder and then extruding the melt kneaded material from a high- pressure zone to a low-pressure zone. The content of polycarbonate bonds in the resin constituting the foam is preferably 1.8-33 mol.%, more preferably 10-20 mol.%.
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