MANUFACTURING METHOD FOR MICROPOROUS MEMBRANE AND MICROPOROUS MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a microporous membrane having high strength and high water permeability and developing an excellent separation capacity by using a polyvinylidene fluoride resin having high chemical resistance. SOLUTION: A polymer solution containing a polyvinylidene fluoride resin and a solvent is discharged from a discharge orifice with a temperature Ts and the discharged solution is cooled to obtain the microporous membrane. The crystallization temperature Tc of the polymer solution is 40-120°C and the average temperature falling speed of the polymer solution at the time of passage at a temperature Tc when the polymer solution is cooled is 2×103-106°C/min and Ts satisfies the relation of Tc≤Ts≤Tc+90. COPYRIGHT: (C)2004,JPO