HOLLOW-FIBER ULTRAFILTRATION MEMBRANE HAVING IMPROVED OXIDATION-RESISTING PROPERTY

摘要

PURPOSE:To obtain a hollow-fiber membrane whose oxidation-resisting property can be improved by restraining the iron content of a resin membrane of poly sulfone or polyether sulfone base. CONSTITUTION:Spinning stock solutions comprising polyether sulfone, polyethylene glycol, dimethyl sulfoxide are pressed out into water through a double annular nozzle using a mixture of an internal solidification liquid, i.e., dimethyl sulfoxide and water. Hollow-fiber membranes thus produced are immersed in aqueous solutions of hydrochloric acid at room temperature for about one hour so that the content of iron becomes 1ppm or less. The hollow-fiber ultrafiltration membranes can be prevented from being deteriorated due to oxidation effect, whereby the life thereof can be extended, resulting in economical advantages.