| 摘要 |
PURPOSE:To obtain a reverse osmosis membrane high in degree of elimination of salt and high in water permeability by incorporating halogen to the dense layer of the reverse osmosis membrane consisting of a cellulose-base derivative. CONSTITUTION:A soln. for producing a membrane obtained by dissolving the mixture of i.e. cellulose triacetate and cellulose diacetate in a solvent and adding an additive such as butanetetracarboxylic acid is cast on a glass plate and a membrane is dried and thereafter immersed into cooling water and the membrane is peeled from the glass plate and treated with hot water. The membrane treated with hot water is immersed into an aq. soln. contg. free chlorine not less than 1ppm and having 5-10 pH. In such manner, the reverse osmosis membrane contg. free chlorine on the surface thereof is obtained. |
