| abstract |
The present invention provides an anisotropically porous membrane which is obtained according to a wet process, which comprises a substantially non-sulfonated aromatic polyether ketone having a crystallinity of 10 percent by weight or higher, and which has open pores having an average pore diameter of 0.02 to 30.00 μm on both surfaces of said membrane at an open pore ratio of 7 to 90 percent. In accordance with the present invention, a porous crystalline aromatic polyether ketone membrane is provided which is excellent in heat resistance, chemical resistance, water resistance, water permeability and a balance of water permeability and fractionating characteristics. |