PURPOSE: To produce a composite membrane excellent in strength, ion exchange capacity, resistance to acid or alkali, etc., by forming an ion exchange resin film layer of a different type on the surface of an ion exchange resin membrane which is a substrate by using a screen printing method.
CONSTITUTION: A composite ion exchange resin membrane is formed by applying an ion exchange resin powder paste, viscosity about 1W105, having an ion exchange capacity different from that of the hereinbelow-described ion exchange resin membrane to the surface of a substrate ion exchange resin membrane, ion exchange capacity about 0.5W4meq/g dry resin by using a screen mesh, mesh number about 10W2,400, thickness about 4μW2mm. Preferably, the above film is hot-pressed under conditions of about 110W250°C and about 0.1W1,000kg/cm2 to effect adhesion to the substrate ion exchange membrane.
MORIMOTO TAKESHI
MATSUBARA TOSHIYA
