| 摘要 |
PROBLEM TO BE SOLVED: To enable the simple, economical and advantageous obtaining of the subject film, excellent in biodegradability and capable of manifesting a high strength and a high elongation with good reproducibility by using a poly(3- hydroxybuianoic acid) having a specific value or above of molecular weight. SOLUTION: This film comprising poly(3-hydroxybutanoic acid) is obtained by orienting the poly(3-hydroxybutanoic acid) having 500,000 number-average molecular weight (e.g. the one obtained by transferring a recombinant DNA containing a gene capable of synthesizing the polymer into a microorganism, transforming the microorganism, culturing the transformed microorganism and collecting the polymer from the interior of the microbial cell) at >=2 times orientation ratio, as necessary, further heat-treating the oriented film at 60-170 deg.C temperature under tension in air. Thereby, the film, having >=30MPa tensile strength and >=15% breaking elongation, excellent in biodegradability and biocompatibility and useful as a packaging material, etc., for medical equipment or foods, etc., can be obtained. |
