| 摘要 |
PURPOSE:To produce a microporous membrane of a low filtration resistance and a high flow rate of filtrate, by casting a membrane-forming stock solution containing a polymer, a swelling agent, a nonsolvent and a solvent on a support, coacervating the cast solution and coagulating the coacervated solution. CONSTITUTION:5-35wt% polymer (e.g., polysulfone), 0.5-10vol% swelling agent (e.g., NaCl), 5-50wt% nonsolvent (e.g., water) and a solvent (e.g., dioxane) are fed to a jacketed dissolution kettle 1 and dissolved to obtain a membrane- forming stock solution. This stock solution is degassed, sent to a solution injector 3 through a pump 2 and cast in the form of a liquid membrane 5 on a casting support 4, and the cast liquid membrane is coacervated by controlling the evaporation of the solvent and the absorption of moisture from air by subjecting the surface of the liquid membrane 5 to irradiation with infrared rays from an infrared panel 14 and/or injection of air conditioned with an air conditioner 6 from an injection port 7. This liquid membrane 5 is immersed in a coagulant tank 8 and subjected to phase separation and coagulation to form a microporous membrane 9, which is peeled from the support 4, passed through a water-washing tank 11 and a dryer 12 and wound around a winder 13. |
