| 摘要 |
PROBLEM TO BE SOLVED: To provide a porous membrane having an excellent surface opening property with an excellent permeation performance and a fractioning performance and further excellent in a surface opening property, a process controlling property, a cost efficiency and a pore formation property, and to provide its production method. SOLUTION: The porous membrane having the excellent surface opening property has a surface opening ratio of 30% or more and is formed by heat induction phase separation of a membrane material polymer and a solvent. The porous membrane is formed by generating the heat induction phase separation and precipitation of the membrane material polymer by preparing a mixture liquid obtained by kneading the membrane material polymer and the solvent which becomes one phase state by making compatible with the membrane material polymer at a specific temperature area and can generate phase separation by temperature variation at a temperature at which the membrane material polymer and the solvent are made compatible and cooling it and then extracting the solvent. A weight reduction ratio for 30 seconds at (heat induction phase separation temperature + 30)°C of the solvent is 10% or less. COPYRIGHT: (C)2005,JPO&NCIPI |
