POROUS MEMBRANE, PROCESS FOR PRODUCING POROUS MEMBRANE, PROCESS FOR PRODUCING CLARIFIED LIQUID, AND POROUS-MEMBRANE MODULE

摘要

A porous membrane with the membrane wall constructed of a hydrophobic polymer and a hydrophilic polymer, wherein when the membrane wall is divided into 3 sections in the film thickness direction to form region "a" containing one wall surface A of the membrane wall, region "c" containing the other wall surface C and region "b" between region "a" and region "c", the hydrophilic polymer content ratio C a in region "a" is greater than the hydrophilic polymer content ratio C c in region "c", and the mean pore size of the wall surface C is larger than the mean pore size of the wall surface A.