| 摘要 |
A dry semi-permeable cellulose acetate membrane is processed from a wet cellulose acetate membrane having an active separating layer and a porous supporting layer. In the process, the wet membrane is immersed in an aqueous solution containing Two to 20 per cent by weight of an organic carboxylic acid having one to three carbon atoms, and 20 TO 40 PER CENT BY WEIGHT OF A POLYHYDRIC ALCOHOL HAVING TWO OR THREE CARBON ATOMS, AND DRIED AT A TEMPERATURE IN THE RANGE OF ABOUT 25 DEG TO 100 DEG C. |
