PRODUCTION OF CROSS-LINKED COMPOSITE MEMBRANE

摘要

PURPOSE:To eliminate the defects on a membrane obtained only by one coating and to obtain the titled extremely thin composite membrane with increased separation factor and permeation velocity by repeatedly forming a cross-linked skin layer on a porous substrate. CONSTITUTION:A soln. contg. a compd. generating a cross-linking reaction due to a covalent bond as the solute is coated on a porous supporting membrane and dried. The solute is simultaneously crosslinked, and a dry thin membrane is formed. Coating and crosslinking are further repeated. Consequently, although defects are developed on a cross-linked thin film formed by one coating and cross-linking, the defects can be eliminated by repeating the treatment. Since the coated surface is cross-linked, the thin film once formed is never redissolved.