Abstract: An ion exchange membrane containing a fluorinated polymer, wherein in a case where by Raman spectroscopy, polarized light orthogonal to the thickness direction of the ion exchange membrane is irradiated to obtain a spectrum chart, whereby the ratio of the peak area a2 of Raman shift 680 to 760 cm?1 to the peak area al of Raman shift 1,025 to 1,095 cm?1 is taken as A1, and by Raman spectroscopy, to a cross section in the thickness direction of the ion exchange membrane, polarized light parallel with the thickness direction is irradiated to obtain a spectrum chart, whereby the ratio of the peak area b2 of Raman shift 920 to 1,025 cm?1 to the peak area b1 of Raman shift 1,025 to 1,095 cm?1 is taken as B1, B1/A1 is at least 1.05.

Abstract: To provide an electrolyte membrane wherein pinholes are less likely to occur even when used in a cell having an anode and a cathode under voltage for a prolonged period of time, as well as an electrolysis apparatus and a redox flow battery which contain the membrane. An electrolyte membrane comprising a fluorinated polymer containing ion-exchange groups and a woven fabric, wherein said woven fabric consists of yarns A extending in one direction and yarns B extending in a direction orthogonal to said yarns A, the aspect ratio YACA2/YACA1 exceeds 1 and is larger than the aspect ratio YAA2/YAA1, and the aspect ratio YACB2/YACB1 exceeds 1 and is larger than the aspect ratio YAB2/YAB1. (YACA2, YACA1, YAA2, YAA1, YACB2, YACB1, YAB2 and YAB1 are as defined in the specification.

Abstract: To provide a membrane electrode assembly, a solid polymer electrolyte membrane, a water electrolysis apparatus, and an electrolytic hydrogenation apparatus, that can reduce the range of increase in electrolysis voltage even when the current density increases when applied to a water electrolysis apparatus or an electrolytic hydrogenation apparatus. The membrane electrode assembly of the present invention comprises an anode having a catalyst layer, a cathode having a catalyst layer, and a solid polymer electrolyte membrane disposed between the anode and the cathode, wherein the solid polymer electrolyte membrane comprises a fluorinated polymer having ion-exchange groups and a woven fabric, wherein the aperture ratio of the woven fabric is at least 50%, and the ratio TAAVE/TBAVE calculated from the average maximum membrane thickness TAAVE and the average minimum membrane thickness TBAVE of the solid polymer electrolyte membrane is at least 1.20.

Abstract: To provide an ion exchange membrane with a catalyst layer, an ion exchange membrane and an electrolytic hydrogenation apparatus, which can lower electrolysis voltage and increase current efficiency at the time of electrolytic hydrogenation of an aromatic compound. The ion exchange membrane with a catalyst layer of the present invention has an inorganic particle layer containing inorganic particles and a binder, a layer (Sa) containing a first fluorinated polymer having sulfonic acid type functional groups, and a layer (Sb) containing a second fluorinated polymer having sulfonic acid type functional groups, and a catalyst layer, in this order, wherein the ion exchange capacity of the above first fluorinated polymer is lower than the ion exchange capacity of the above second fluorinated polymer.

Abstract: To provide a membrane electrode assembly which is excellent in strength and is capable of reducing the electrolysis voltage when applied to a water electrolysis apparatus, and such a water electrolysis apparatus. The membrane electrode assembly of the present invention is a membrane electrode assembly for use in a water electrolysis apparatus, comprising an anode having a catalyst layer, a cathode having a catalyst layer, and a polymer electrolyte membrane disposed between the anode and the cathode, wherein the polymer electrolyte membrane comprises a fluorinated polymer having ion exchange groups, and a woven fabric, the aperture ratio of the woven fabric is at least 50%, the denier number of warp yarns and the denier number of weft yarns, constituting the woven fabric, are each independently at least 2, and a relationship of Y?240X?170 is satisfied where the membrane thickness of the polymer electrolyte membrane is Y ?m, and the ion exchange capacity of the fluorinated polymer is X meq/g dry resin.

Abstract: To provide an ion-exchange membrane that, when being used in a redox flow battery, provides excellent current efficiency and can suppress reduction in voltage efficiency. The ion-exchange membrane contains a fluorinated polymer having sulfonic acid-type functional groups and is characterized in that the difference (D?Dc) between the distance D between ion clusters measured by the small angle X-ray scattering method, and the diameter Dc of an ion cluster is larger than 0 and at most 0.50 nm.

Abstract: To provide an ion exchange membrane which is excellent in dimensional stability in an in-plane direction when immersed in an electrolytic solution, and a method for producing a dry ion exchange membrane. The ion exchange membrane according to the present invention is an ion exchange membrane containing a fluorinated polymer, wherein in a case where by Raman spectroscopy, polarized light orthogonal to the thickness direction of the ion exchange membrane is irradiated to obtain a spectrum chart, whereby the ratio of the peak area a2 of Raman shift 680 to 760 cm?1 to the peak area al of Raman shift 1,025 to 1,095 cm?1 is taken as A1, and by Raman spectroscopy, to a cross section in the thickness direction of the ion exchange membrane, polarized light parallel with the thickness direction is irradiated to obtain a spectrum chart, whereby the ratio of the peak area b2 of Raman shift 920 to 1,025 cm?1 to the peak area b1 of Raman shift 1,025 to 1,095 cm?1 is taken as B1, B1/A1 is at least 1.05.