Process for producing composite semipermeable membrane employing a polyfunctional amine solution and high flash point - solvent

摘要

A process of producing a composite semipermeable membrane which includes applying a polyfunctional amine solution and a polyfunctional acid halide solution in a hydrocarbon-based solvent having a flash point of not lower than 10 DEG C. on a surface of a microporous substrate to allow interfacial polycondensation reaction so as to form a cross-linked polyamide-based ultra-thin membrane superposed on the microporous substrate, then blowing a gas on the surface of the ultra-thin membrane so as to evaporate the hydrocarbon-based solvent, which gas has a velocity at the surface of 2-20 m/sec., a temperature of 10 DEG -80 DEG C. that is lower than the flash point of the hydrocarbon-based solvent, and an absolute humidity of not less than 1 g of water per 1 kg of dry gas.