公开(公告)号：US20240375060A1

公开(公告)日：2024-11-14

申请号：US18692084

申请日：2022-09-26

Applicant: TORAY INDUSTRIES, INC.

Inventor： Shun SHIMURA ,  Ryo SATO ,  Masayuki HANAKAWA ,  Masahiro KITABATA ,  Naoki YAMAMOTO

IPC: B01D69/02 ,  B01D67/00 ,  B01D69/08 ,  B01D69/10 ,  B01D71/16 ,  B01D71/34

Abstract: Conventional porous membranes have a mesh structure having a relatively large pore diameter in order to improve the removability of a relatively large component such as a virus. When a contaminative liquid to be filtered is filtered, contaminants are easily accumulated in the porous membranes, clogging or the like occurs in the porous membranes, and contamination of the porous membranes easily occurs. Accordingly, an object is to provide a porous membrane having high contamination resistance and high-precision removability. To achieve the object, provided is a porous membrane including, in at least one surface, a surface portion spanning 10 μm in thickness from the surface, being denser than an inner portion, and having a removal rate T of dextran having a weight-average molecular weight of 40,000 Da of 60 to 95%, in which a number of surface pores per unit area observed on the surface of the surface portion is 200 pores/μm2 to 2,000 pores/μm2.