| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyimide porous membrane homogeneous in quality throughout the membrane and highly permeable to gas or the like, and to provide a method for manufacturing the same with high reproducibility. <P>SOLUTION: In this polyimide porous membrane, pores are formed on both surfaces with the surface aperture ratio accounting for ≥50% on at least one of the surfaces, the mean diameter of through paths from the membrane surface through the membrane rear surface is 0.01-0.5 μm, and through paths having a diameter of ≥1.0 μm number zero per 1 cm<SP>2</SP>. A polymer solution of a polyimide having a limiting viscosity number of ≥2.7 but ≤8.0 or of a precursor thereto is cast on a substrate, and then a protective solvent layer comprising a soluble solvent or a nonsolvent is deposited on the cast matter. The laminate of the liquids is immersed in a coagulating liquid, where a concentration gradient is retained between the polymer solution and the protective solvent layer with the two not mixed completely. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
