Patent ID: 9346020
Filing Date: 2016-05-24
CPC Classification: B01D

Claim Text:
1. A multilayered charge-mosaic membrane, comprising: (A) a porous supporting layer (A) comprising, in layer form, fibers having an average fiber diameter of 1 μm or more and 100 μm or less; (B) a porous intermediate layer (B) comprising, in layer form, fibers having an average fiber diameter of 0.01 μm or more and less than 1 μm; and (C) a charge-mosaic layer (C) comprising cationic polymer domains and anionic polymer domains, wherein the cationic polymer domains comprise a cationic polymer and the anionic domains comprise an anionic polymer, wherein: the layers are located in the following order: the porous supporting layer (A), the porous intermediate layer (B) and the charge-mosaic layer (C), or the charge-mosaic layer (C) is formed within the porous intermediate layer (B); the porous supporting layer (A), the porous intermediate layer (B), or both, comprises a fiber layer comprising hydrophilic fibers in at least 50% by weight; the porous intermediate layer (B) has a thickness of 0.1 to 100 μm; a porosity of the porous supporting layer (A) is larger than a porosity the porous intermediate layer (B); the charge-mosaic layer (C) has a charge structure which comprises the cationic polymer domains and anionic polymer domains which are alternately aligned in a first horizontal direction and each of the alternately aligned cationic polymer domains and anionic polymer domains continuously extend from one side of the charge-mosaic layer (C) to the other side of the charge-mosaic layer (C) in a second horizontal direction which is perpendicular to the first horizontal direction; and both of the cationic polymer and the anionic polymer, constituting the charge-mosaic layer (C), are a block copolymer comprising a polymer block comprising an ionic group and a vinyl alcohol polymer block.