Process for making a composite membrane with high selectivity and flux

摘要

A composite membrane including a microporous polymer film having a high air permeability as a support and a non-porous gas or vapor separating coating having a thickness of not more than 15 mu m is provided. The separation factor and flux of the membrane are substantially equal to those of the coating. Also provided is a process for the manufacture of a composite membrane including a support and a gas or vapor separating coating by drawing a polymeric film to which the coating material has been applied, and increasing the viscosity of the coating during drawing.