STRONGLY STRETCHED ALIPHATIC POLYESTER MOLDINGS

摘要

A crystalline aliphatic polyester alone or a laminate thereof is subjected to intense stretching under appropriately set stretching conditions to provide a stretched product with remarkably improved physical properties as represented by impact resistance and gas-barrier property inclusive of hot water resistance. The thus-obtained stretched product of aliphatic polyester is provided with increased orientation degree at not only amorphous parts but also crystalline parts as represented by (a) remarkably higher crystal melting point compared with the unstretched product, (b) an increase in sub-dispersion peak temperature according to dynamic viscoelasticity measurement, or (c) an increase in orientation degree according to wide-angle X-ray diffractometry and an increase in main dispersion peak temperature according to dynamic viscoelasticity measurement.