| 摘要 |
<p>A process for selectively separating water-soluble valuables such as various organic compounds dissolved in water or transition metal compounds dissolved in water as ions or complexes from an aqueous solution containing them in slight amounts according to a reverse osmosis method by bringing the aqueous solution into contact with a semipermeable membrane under a pressure exceeding the osmotic pressure, which comprises employing, as the semipermeable membrane, a semipermeable composite membrane comprising a porous support having provided thereon a barrier layer of about 0.01 to 0.1 (Alpha) in thickness made of a cross-linked polymer having the isocyanurate structure represented by the following general formula (I) and, if necessary, a protective layer of about 0.1 to 10 (Alpha) composed of polyvinyl alcohol and/or partially saponified polyvinyl acetate on the barrier layer: (FORMULA) wherein R1 represents a member selected from the group consisting of a glycidyl group and a group represented by the following formula (II): -A - X- (B - X)n - R" (II) (wherein A represents an alkylene group containing 2 to 5 carbon atoms and optionally having a hydroxy group and/or a glycidyl group, B represents an alkylene group containing 1 to 17 carbon atoms, X represents -O- and/or (Alpha)-CO- bond, n represents 0 or a positive integer and, when n represents an integer of 1 or more, B may be the same as, or different from, each other, and R" represents a hydrogen atom or an alkyl group containing 2 to 5 carbon atoms and having a hydroxy group and/or a glycidyl group), R2 represents a hydrogen atom, an alkyl group containing 2 to 5 carbon atoms or that defined for R1, and the isocyanurate structure of the aforesaid cross-linked polymer is bonded via (Alpha)-O- and/or -C-O- bond. </p> |
