US 12,226,742 B2
Method for manufacturing porous membrane and porous membrane
Akihiro Ikeyama, Minami-ashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on May 13, 2021, as Appl. No. 17/319,730.
Application 17/319,730 is a continuation of application No. PCT/JP2019/046687, filed on Nov. 29, 2019.
Claims priority of application No. 2018-225127 (JP), filed on Nov. 30, 2018.
Prior Publication US 2021/0260538 A1, Aug. 26, 2021
Int. Cl. B01D 71/68 (2006.01); B01D 67/00 (2006.01); B01D 69/10 (2006.01); B01D 69/12 (2006.01); B01D 71/38 (2006.01); B01D 71/44 (2006.01)
CPC B01D 71/68 (2013.01) [B01D 67/0011 (2013.01); B01D 67/0013 (2013.01); B01D 69/1071 (2022.08); B01D 69/125 (2013.01); B01D 71/381 (2022.08); B01D 71/441 (2022.08); B01D 2323/30 (2013.01); B01D 2323/34 (2013.01); B01D 2325/022 (2013.01); B01D 2325/023 (2013.01); B01D 2325/0283 (2022.08); B01D 2325/04 (2013.01); B01D 2325/20 (2013.01); B01D 2325/36 (2013.01)] 24 Claims
OG exemplary drawing
 
23. A porous membrane comprising:
a water-insoluble resin; and
a water-soluble resin including a monomer unit of polyvinylpyrrolidone or a monomer unit of polyvinyl alcohol,
wherein an insoluble component which is a cross-linked water-soluble resin is 1.2% by mass or more of a dry mass of the porous membrane, said mass percentage being obtained by immersing 60 cm2 of the porous membrane in 50 mL of methylene chloride for 24 hours, measuring the mass of the insoluble component and determining the percentage of the insoluble component based on the dry mass of the porous membrane before the immersion,
the porous membrane has a layered compact portion with a minimum pore diameter inside the membrane, and
a thickness of the porous membrane is more than 40 μm.