US 12,274,985 B2
Porous membrane
Yasutaka Takazono, Tokyo (JP); and Masayasu Komuro, Tokyo (JP)
Assigned to ASAHI KASEI MEDICAL CO., LTD., Tokyo (JP)
Appl. No. 17/598,654
Filed by ASAHI KASEI MEDICAL CO., LTD., Tokyo (JP)
PCT Filed Mar. 27, 2020, PCT No. PCT/JP2020/013889
§ 371(c)(1), (2) Date Sep. 27, 2021,
PCT Pub. No. WO2020/203716, PCT Pub. Date Oct. 8, 2020.
Claims priority of application No. 2019-065206 (JP), filed on Mar. 29, 2019.
Prior Publication US 2022/0168694 A1, Jun. 2, 2022
Int. Cl. B01D 69/02 (2006.01); B01D 67/00 (2006.01); B01D 69/06 (2006.01); B01D 69/10 (2006.01); B01D 71/40 (2006.01); B01D 71/68 (2006.01); D01F 6/76 (2006.01); D06M 15/263 (2006.01)
CPC B01D 69/02 (2013.01) [B01D 67/0088 (2013.01); B01D 69/06 (2013.01); B01D 69/1071 (2022.08); B01D 71/4011 (2022.08); B01D 71/68 (2013.01); D01F 6/76 (2013.01); D06M 15/263 (2013.01); B01D 2323/02 (2013.01); B01D 2325/20 (2013.01); B01D 2325/36 (2013.01); B01D 2325/38 (2013.01)] 2 Claims
 
1. A method for producing a porous membrane that includes a hydrophobic polymer and a hydrophilic polymer, or for reducing membrane adhesion after hydrophilizing, the method comprising:
a hydrophilization process of hydrophilizing a base material membrane comprising a hydrophobic polymer by coating the base material membrane with a hydrophilic polymer to obtain a hydrophilized porous membrane, wherein the hydrophilic polymer is a methacrylate-based polymer; and
an adjustment process of treating the hydrophilized porous membrane so that an average value T of ratios of the number of counts of ions derived from the hydrophilic polymer to the number of counts of ions derived from the hydrophobic polymer is 1.0 or more based on a time-of-flight secondary ion mass spectrometry (TOF-SIMS) measurement of a surface of the porous membrane, wherein
the ions derived from the hydrophilic polymer are C4H5O2 (m/z=85) ions, and wherein
the adjustment process comprises subjecting the hydrophilized porous membrane to high-pressure hot-water treatment in a state where the membrane is completely immersed in hot water and the temperature of the hot water is 120° C. or higher.