| 摘要 |
PURPOSE:To prepare compound film type ultrafilter membrane having high resistance to delamination and sufficient antifouling property on the necessary part of the surface by flow coasting or extruding at least two kinds of doping liquid simultaneously, and transforming the doping liquid to gel by a dry/wet method to film. CONSTITUTION:The high molecular porous film is formed of a combination of a high molecular polymer having no polar group and a high molecular polymer having polar groups, pref. polysulfone and sulfonated polysulfone. Suitable sulfonated polysulfone is one having 0.5-1 degree of sulfonation per one recurrent unit of the polymer. Suitable solvent is one capable of dissolving both polymers to be used and compatibility with water used in the gelling bath. Suitable concn. of the doping liquid is 15-25wt%. The casting is executed by moving the doping liquid A and B from each adjacent nozzle separated by nozzle walls 1, 2, 3 having different height of the bottom edge to each other. |
