COMPOSITE SEMIPERMEABLE MEMBRANE, COMPOSITE SEMIPERMEABLE MEMBRANE SEPARATION ELEMENT, AND THEIR MANUFACTURING METHOD AND REWETTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for suppressing deterioration in membrane performance by drying, which can stick and seal the whole membrane or a region wider than a stuck and sealed part in a state that they are dried to effectively suppress the leak generation in the stuck and sealed part, and to provide a method for improving membrane performance by using a process for drying a membrane. SOLUTION: In this manufacturing method for a composite semipermeable membrane, a semipermeable membrane is brought into contact with an aqueous solution of an oligoalkylene glycol or of an alkylene polyol, and then dried. The composite semipermeable membrane is manufactured by this method. The composite semipermeable membrane is manufactured by sticking and sealing the composite semipermeable membrane manufactured by this method. The rewetting method comprises a process contacting the composite semipermeable membrane and the composite semipermeable membrane separation element with an alcohol having a carbon number of 1-4 or an aqueous solution of alcohol. The composite semipermeable membrane and the composite semipermeable membrane separation element are rewetted by this rewetting method.