| 摘要 |
PURPOSE:To obtain membrane with microfine pores having superior anticoagulative effect for blood by using thermoplastic polyester film comprising >=80mol% 3-hydroxybutyric acid unit contg. microfine pores communicating to each other on both surface and inside of the film. CONSTITUTION:Thermoplastic aliphatic polyester contg. recurrent units comprising 3-hydroxybutyric acid units alone, namely polyhydroxy butyrate (PHB), contained in microorganism is obtd. when microorganism such as Al aligenes eutrophus or Azotobacter vinelandii etc. is cultivated in aq. medium with glucose, etc. After separating PHB, it is formed to a hollow yarn by the melting method, and crystallised at >=50 deg.C and <=m.p., and drawn in the longitudinal direction. The drawing after the second stage drawing is performed at >=100 deg.C and <=m.p. with pref. 1.3-6 times draw ratio. The bubble point when ethanol is used is preferred to be 1-20kg/cm<2>. |
