| 摘要 |
PURPOSE:To recover the current efficiency of a deteriorated cation exchange membrane for electrolysis of alkali chloride to above the original performance by dipping the membrane in polyethylene glycol followed by heating between smooth plates, treatment with hydrochloric acid and dipping in an aq. soln. of NaOH. CONSTITUTION:A deteriorated perfluorocarbon type cation exchange membrane for electrolysis of alkali chloride is dipped in polyethylene glycol having a MW of 200-700. The dipped membrane is then held between smooth plates such as glass plates, heat treated at 40-180 deg.C, treated with 0.05-10, esp. 0.5-8 N hydrochloric acid at 40-95, esp. 60-85 deg.C, and dipped in an aq. soln. of NaOH to recover the membrane performance. The membrane is produced as follows: for example, one side alone of a membrane of a copolymer of CF2=CF2 and CF2= CFOC(CF3)FOCF2CF2SO2F is contacted to ethylenediamine, and Teflon is introduced into the membrane, which is then heat treated and hydrolyzed. |
