| 摘要 |
<p>PURPOSE:To obtain the composite membrane excellent in permeability, separative performance and mechanical strength and capable of being used in the industry by forming the thin layer of a hydrophilic natural polymer on a partially hydrolyzed polyacrylonitrile-based based membrane. CONSTITUTION:The polyacrylonitrile-based base membrane is partially hydrolyzed by the solid-liquid contact method which is left standing in aq. alkali or a soln. of alkali in alcohol or the like. The thin layer of a hydrophilic natural polymer is then formed on the base membrane by dipping in an aq. polymer soln., coating with a bar coater, spin coater, etc. The polysaccharides such as a water-soluble cellulose derivative is used as the hydrophilic natural polymer. Since the base membrane is partially hydrolyzed, the affinity for the thin layer is improved, and the thin layer with less defects is formed. Consequently, a membrane excellent in durability, permeability and separative performance is obtained.</p> |
