| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a PVDF porous membrane which has high water permeability and high chemical resistance to washing chemicals and the like that has been difficult to materialize with a conventional high polymer porous membrane and which can be used for a long period of time, and to provide a method of producing the PVDF porous membrane.SOLUTION: There is provided the porous membrane in which a degree of crystallization of a PVDF resin in a porous membrane is 50% or more and 90% or less, and the product of the degree of crystallization of the PVDF resin in the porous membrane and the specific surface area of the membrane is 300 (% m/g) or more but not more than 2,000 (% m/g). There is also provided the method of producing a porous membrane having a PVDF resin as a main component thereof by extruding, from a molding nozzle, a membrane-producing solution which at least contains a hydrophobic polymer component having a PVDF resin as a main component thereof, a hydrophilic polymer component and a common solvent for both the hydrophobic and hydrophilic polymer components, and solidifying the membrane-producing solution in a solution having water as a main component thereof, wherein polyethylene glycol having a weight average molecular weight of 20,000 or more but not more than 150,000 is used as the hydrophilic polymer component.</p> |
