| 摘要 |
PURPOSE:To improve the fragility of a hollow fiber and to eliminate the generation of a leak by constituting an outer-shell layer of the hollow fiber-shaped porous membrane of a porous structure denser than that of the reticular inner-shell layer, and specifying the ratio of the mean pore diameter of the inner-shell layer to the mean pore diameter on the outer surface, the mean porosity of the wall membrane, and the water permeability of the membrane. CONSTITUTION:Cellulose acetate, polymethyl methacrylate, and cellulose nitrate are dissolved into a solvent, and a swelling agent and an inorganic salt are added to the soln. to obtain a spinning soln. The soln. is spewed from an annular spinneret, and immediately introduced into a coagulation bath. A liquid having the same composition as the coagulation bath is simultaneously charged into the bath from the inside of the spinneret. Accordingly, a dense outer-shell layer is formed in the vicinity of the outer surface and 2-layered structure can be formed with the reticular inner-shell layer. The ratio of the mean pore diameter of the inner-shell layer to the mean pore diameter of the outer surface is regulated to 1-3, the mean porosity of the whole of the wall membrane to >=60%, and the water permeability of the porous membrane to 1,000- 10,000ml/m<3>.hr.mm.Hg, respectively. Consequently, a hollow fiber having excellent separation efficiency of plasma can be obtained.
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