ELECTROLYTIC MEMBRANE

摘要

Provided is an electrolytic membrane, the percentage change in the surface area of which during use is low. Said electrolytic membrane exhibits excellent ion permeability and makes it possible to prevent voltage increases due to gases generated at electrodes during electrolysis becoming attached to the surface of the membrane. This electrolytic membrane comprises an ion-permeable membrane and can be wetted by an aqueous solution of potassium hydroxide having a concentration of 30 wt.%. The mean pore diameter of said ion-permeable membrane is between 0.01 and 20 µm, inclusive, and when the ion-permeable membrane is immersed in purified water, the surface area thereof changes by no more than 20%. In a preferred embodiment, the electrical resistivity of the ion-permeable membrane when an aqueous solution of potassium hydroxide at a temperature of 25°C and a concentration of 40 wt.% is used as the electrolyte is no more than 0.5 &OHgr;∙cm2.