The present invention provides a strong polymer electrolyte membrane which can provide a water electrolyzer operable at low electrolysis voltage. The polymer electrolyte membrane of the present invention comprises a fluorinated polymer and a woven fabric, wherein the weight of the woven fabric is from 20 to 95 g/m.sup.2, and the warp and weft of the woven fabric independently have a denier of from 30 to 100.

Provided is a polymer electrolyte membrane comprising: (a) a polyelectrolyte having an ion exchange capacity of from 0.5 to 3.0 meq/g; and (b) at least one scandium compound selected from the group consisting of scandium oxide, scandium acetate, scandium sulfate, scandium nitrate, and scandium carbonate, wherein a polyethylene glycol (PEG)-derived compound in the polymer electrolyte membrane has a total content of 10 ppm or less.

The invention pertains to certain fluoropolymer-based hybrid organic/inorganic composites, to polymer electrolytes obtained therefrom and to use of said polymer electrolytes in electrochemical devices.

The present invention relates to a solid polymer electrolyte in the form of an organic-organic composite material, intended to be used in a lithium-polymer battery. The invention also relates to a process for manufacturing such an electrolyte. This electrolyte is notably intended for making a lithium-polymer battery or an “all-solid” battery, notably as regards the ion-conducting separator. The invention thus also relates to a battery separator comprising such a polymer electrolyte, to processes for manufacturing same and to the battery incorporating this electrolyte.

The invention relates to inorganic particles which are covalently bonded to first polymer chains made up of at least one polymer carrying proton exchange groups, optionally in the form of salts, and bonded to second polymer chains made up of at least one fluorinated polymer that does not carry any proton exchange groups, the second chains being bonded to the particles via organic spacer groups, or the second chains being bonded to first chains via organic spacer groups, or some of the second chains being bonded to the particles via organic spacer groups while the remaining second chains are bonded to first chains via organic spacer groups.

Provided are a polymer composition that can suppress bubbling during membrane formation and peeling of a laminated membrane and an ion-exchange membrane. The polymer composition is a polymer composition including: a fluorine-containing copolymer including a unit (a) derived from a perfluorovinyl compound having a side chain having an ionic group and a unit (b) derived from a fluoroolefin; and a low molecular weight compound (a) having a functional group represented by —COOX (X is H, NH.sub.4, or a monovalent metal ion), wherein a content of the low molecular weight compound (a) is 600 ppm or less based on a mass of the polymer composition.

Provided are a polymer composition that can suppress bubbling during membrane formation and peeling of a laminated membrane and an ion-exchange membrane. The polymer composition is a polymer composition including: a fluorine-containing copolymer including a unit (a) derived from a perfluorovinyl compound having a side chain having an ionic group and a unit (b) derived from a fluoroolefin; and a low molecular weight compound (a) having a functional group represented by —COOX (X is H, NH.sub.4, or a monovalent metal ion), wherein a content of the low molecular weight compound (a) is 600 ppm or less based on a mass of the polymer composition.

To provide an ion exchange membrane for alkali chloride electrolysis which has a low membrane resistance and which is capable of reducing the electrolysis voltage during the alkali chloride electrolysis, while increasing the membrane strength. An ion exchange membrane 1 for alkali chloride electrolysis wherein a reinforcing material 20 obtained by weaving with reinforcing yarns 22 and sacrificial yarns 24 is embedded in a fluoropolymer having ion exchange groups, the ion exchange membrane 1 comprises elution holes (28) formed by eluting at least a portion of a material of the sacrificial yarns 24, and in a cross section perpendicular to the length direction of the yarns, the total area (S) obtained by adding the cross-sectional area of an elution hole 28 and the cross-sectional area of a sacrificial yarn 24 remaining in the elution hole 28 is from 500 to 1,200 μm.sup.2, and the number (n) of elution holes 28 between adjacent reinforcing yarns 22 is at least 10.

To provide an ion exchange membrane for alkali chloride electrolysis for which membrane strength is increased while membrane resistance is reduced to reduce electrolysis voltage during alkali chloride electrolysis and which prevents peeling between layers (S) and a layer (C). The ion exchange membrane for alkali chloride electrolysis comprises a layer (C) which comprises a fluorinated polymer having carboxylic acid functional groups, at least two layers (S) which comprise a fluorinated polymer having sulfonic acid functional groups, and a reinforcing material, wherein the layers (S) include a layer (Sa) and a layer (Sb), the layer (Sa) is a layer which is adjacent to the layer (C), the layer (Sb) is a layer which is not adjacent to the layer (C), the reinforcing material is disposed in the layer (Sb) substantially in parallel to the layer (Sb) in a state not in contact with the layer (Sa), and the ion exchange capacity of the layer (Sa) is lower than the ion exchange capacity of the layer (Sb).

The invention pertains to a process for the manufacture of a polymer electrolyte membrane based on a fluoropolymer hybrid organic/inorganic composite, to a polymer electrolyte obtained thereof and to uses of said polymer electrolyte and membranes obtained therefrom in various applications, especially in electrochemical and in photo-electrochemical applications.