To provide a multilayer microporous membrane having a high permeation rate of liquids or the like and a high blocking performance of fine particles which is useful as a separation membrane used for removing an unnecessary material from a liquid containing a useful material represented by a physiologically active substance and an unnecessary material represented by a pathogenic substance and for refining the useful material, and also to provide a usage method.
The multilayer microporous membrane is a polymer porous membrane comprising a multilayered structure where high aperture rate layers are respectively integrally laminated at both the surfaces of a low aperture rate layer. A maximum hole diameter obtained by a bubble point process is 10-100 nm. The multilayer microporous membrane has at least two or more minimum hole diameter layers in the low aperture rate layer. The minimum hole diameter layers in the low aperture rate layer are located in contact with the high aperture rate layer, and the hole diameter of a central part in a membrane thickness direction in the low aperture rate layer is larger than that of the circumferential part of the central part.
SAEKI YUKIAKI
MOCHIZUKI TAKENA
MAEDA TAKURO
| JP2005506168A | 2005-03-03 |
| WO2003026779A1 | 2003-04-03 | |||
| WO2001028667A1 | 2001-04-26 | |||
| WO2007043553A1 | 2007-04-19 |
Kyoko Yoshimi
Sanae Goto
Kiyoshi Fujino