Patent Number: 8,573,408

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

Abstract: 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.

Inventors: Ishizuka; Kenichi (Ashigarakami-gun, JP), Nishita; Nobuhiro (Ashigarakami-gun, JP)

Assignee: FUJIFILM Corporation

International Classification: B01D 71/28 (20060101); B01D 71/36 (20060101); B01D 39/14 (20060101)

Expiration Date: 1/05/12017