Crystalline polymer microporous membrane, method for producing the same, and filtration filter

摘要

A crystalline polymer microporous membrane, which contains: a microporous film formed of a crystalline polymer, which has a plurality of pores; and a hydrophilic polymer containing a hydroxyl group, which covers exposed surfaces of the microporous film, wherein the plurality of pores have a larger average pore diameter at a first surface of the film than the average pore diameter at a second surface of the film, and the average pore diameter of the pores continuously changes from the first surface to the second surface.