摘要 |
PURPOSE:To obtain a reverse osmotic membrane excellent in durability, strength, and solvent resistance by superposing a barrier film layer of a crosslinked polymer polymerized by an acid catalyst and a protective film layer of a composite membrane consisting of a partially saponified product on a porous substrate. CONSTITUTION:On the surface of the anisotropic porous substrate of polysulfone, polyvinyl chloride, etc., a thickness of approx. 0.01-0.1mu of the barrier film layer of a bridged polymer composed primarily of a compound with an acid-polymerizable isocyanurate main chain and/or furfuryl alcohol is formed, and then on the barrier film layer, a protective layer with an optical interference stripe, having high water insolubility and high solvent resistance, composed of the partially saponified products of polyvinyl alcohol and/or polyvinyl acetate is formed. The semipermeable composite membrane thus obtained has high resistance to mechanical damage, highly stable separation capacity for a long period of time, and high solvent resistance. |