Preparation of asymmetric porous membrane

Abstract

Abstract PURPOSE:To obtain an asymmetric porous membrane excellent in permeability and strength, by a method wherein a solution of a film forming polymer is applied on one surface of a porous reinforcing substrate and a solvent not coagulating said polymer is applied thereon from the back surface thereof and the resulting coated substrate is immersed in a coagulating bath to coagulate the polymer coating. CONSTITUTION:A solution of a film forming polymer such as polysulfone or polyacrylonitrile is applied on one surface of a porous reinforcing substrate such as woven or nonwoven fabric and a solvent not coagulating the film forming polymer and pref. being a good solvent thereof, such as N-methyl-2-pyrrolidone or dimethylformamide, is applied thereon from the back surface of the coated surface to prevent the formation of a skin layer on the back surface thereof. In the next step, the coated substrate is immersed in a coagulating bath to form porous membrane on the reinforcing substrate and, thereby, an objective asymmetric porous membrane having the skin layer formed only on one surface thereof is obtained. The obtained porous membrane is suitably used as reverse osmosis membrane or ultrafiltration membrane.

Inventors

• 👤 Shigeyoshi Kobayashi
• 👤 小林　重義
• 👤 Noriyuki Yoshihara
• 👤 吉原　紀幸
• 👤 Hide Nakamura
• 👤 秀 中村
• 👤 Tetsuro Yasuda
• 👤 安田　哲朗

Bibliographic Details