| 摘要 |
<p>A process for producing a hollow-fiber separative membrane by ejecting a spinning dope containing a polysulfone polymer into a gas through a tube-in-orifice type nozzle and passing the ejected dope into a coagulating fluid to remove the solvent, wherein the spinning dope is one prepared by dissolving 5 to 30 wt.% of a polysulfone polymer, 5 to 20 wt.% of polyvinylpyrrolidone and 2 to 8 wt.% of water in a polar organic solvent, with each percentage being based on the total amount of the spinning dope, and the spinning is conducted at a nozzle temperature of 20 to 60 °C. The obtained membrane has a spongy structure as a whole and at least either of the inside and outside surfaces of the membrane is constituted of a dense layer having a thickness of 0.05 to 0.3 νm. Further, it exhibits a water permeability of 500 to 800 ml/Hr.mmHg.m2 and cutoff ratios of 30 % or below and 80 % or above against dextran 10,000 and dextran 70,000, respectively.</p> |
