PROCESS FOR PREPARING AROMATIC POLYIMIDE SEMIPERMEABLE MEMBRANES

摘要

A polyimide semipermeable membrane is prepared by the process comprising the steps of: preparing a solution of a polyimide material consisting essentially of at least one aromatic polyimide comprising at least 90 molar % of at least one recurring unit of the formula (I): (I) wherein R represents a divalent aromatic radical, in a solvent consisting of at least one phenol compound in the state of a liquid or melt; forming a thin layer of the polyimide solution, and; coagulating the thin layer of the polyimide solution by bringing the thin layer into contact with a coagulating liquid to form a semipermeable membrane.