Abstract: An electrochromic display composed of a transparent electroconductive membrane, an electrochromic membrane, an ion-exchange membrane and a counter electrode in a laminated structure. The ion-exchange membrane is a bipolar ion-exchange membrane composed of at least one cation-exchange membrane layer having cation-exchange groups and at least one anion-exchange membrane layer containing anion-exchange groups in a laminated structure. The electrochromic display has a superior response speed, contrast and resolving power as well as a long service life.

Abstract: Disclosed is a process for the preparation of a fluorine-containing compound having a carboxyl group, which comprises irradiating a fluorine-containing compound having a sulfonyl group with ultraviolet rays in the presence of a nitrogen compound.According to this process, a fluorine-containing compound having a carboxyl group can be prepared from a fluorine-containing compound having a sulfonyl group at a high efficiency very simply by one step.

Abstract: A process for preparing a fluorine-containing polymer having carboxyl groups, which comprises subjecting a fluorine-containing polymer having sulfonyl halide groups bonded to it to an oxidation reaction at a temperature of not more than 250.degree. C.; and a process for electrolysis, using as a diaphragm a member of the polymer obtained by the above process.

Abstract: A process for preparing a fluorine-containing polymer having carboxyl groups, which comprises subjecting a fluorine-containing polymer having sulfonyl halide groups bonded to it to an oxidation reaction at a temperature of not more than 250.degree. C.; and a process for electrolysis, using as a diaphragm a member of the polymer obtained by the above process.

Abstract: An electrolytic diaphragm consisting essentially of a main layer composed of a polymeric membranous material uniformly containing cation exchange groups and fluorine atoms chemically bonded thereto and a secondary layer having a smaller thickness than said main layer and composed of at least one of an electrically neutral layer and a layer containing an anion exchange group, said secondary layer being in intimate contact with said main layer at at least one surface layer portion or interior of said main layer. A method for electrolyzing alkali salts, using aforesaid electrolytic diaphragm.

Abstract: An electrolytic diaphragm consisting essentially of a main layer composed of a polymeric membranous material uniformly containing cation exchange groups and fluorine atoms chemically bonded thereto and a secondary layer having a smaller thickness than said main layer and composed of at least one of an electrically neutral layer and a layer containing an anion exchange group, said secondary layer being in intimate contact with said main layer at at least one surface layer portion or interior of said main layer. A method for electrolyzing alkali salts, using aforesaid electrolytic diaphragm.

Abstract: A cathode-structure for liquid-phase electrolysis comprises a cathode and a polymer containing a cation exchange group, with the polymer being laminated in the form of a film on one surface of the cathode.

Abstract: An anode-structure for liquid-phase electrolysis comprising an anode and a polymer containing a cation exchange group, said polymer being laminated in the form of a film on one surface of said anode.