| 摘要 |
PURPOSE:To obtain a dry semipermeable membrane without causing change in molecular weight cut-off and permeation characteristics remaining substantially no residue in the membrane by treating wet semipermeable membrane with aq. soln. of polyhydric alcohol, and treating thereafter with nonpolar org. solvent and drying. CONSTITUTION:Wet semipermeable membrane comprising polyamide, polyimide, or polysulfone polymer is treated in the first stage with aq. soln. of 12-16C polyhydric alcohol and/or its deriv. Suitable concn. of the aq. soln. is 10-80wt%. Then, the treated membrane is dried at room temp.-60 deg.C for 10-100hr, and treated further with an org. solvent miscible with the polyhydric alcohol, treated thereafter with a nonpolar org. solvent having 6-10 solubility parameter or with a polar org. solvent miscible with the polyhydric alcohol which does not swell nor dissolve the polymer constituting the semipermeable membrane. The treated product is then dried, pref. at 5-70 deg.C for 10-100hr. |
