| 摘要 |
PURPOSE: To enable direct drying from an annealing stage by die casting of e.g. die casting soln. consisting of cellulose acetate and its solvent to form a uniform thin film and solidifying the film in water, then treating the film with a specific desiccant. CONSTITUTION: The die casting soln. consisting of the cellulose acetate and its solvent is die cast to form the uniform thin layer of the soln. and, thereafter, the film is condensed in the water. A hydrophobic org. compd. having a b.p. higher than 100 deg.C in a standard state and having weak hydrogen bondability and low dissolution parameter is introduced as the desiccant therein and, thereafter, the film is dried, by which the semiphermeable asymmetric type dry cellulose membrane is produced. The cellulose membrane has excellent performance in desalting by reverse osmosis, ultrafiltration, non-aqueous soln. sepn., osmosis vaporization, component sepn. of a gaseous mixture or the like. |
