Abstract: A material for solid polymer electrolyte, made of a polyether polymer having a moisture content in the range of 400 to 5,000 ppm by weight. A formed solid polymer electrolyte, which is made by mixing the material for solid polymer electrolyte together with an electrolyte salt compound soluble in the polyether polymer, has good ionic conductivity and high mechanical strength. A polyether polymer having a moisture content not larger than 0.04% by weight and a toluene-insoluble content not larger than 5% by weight. This polyether polymer gives a formed solid polymer electrolyte having a smooth surface.

Abstract: A process for producing a polyether polymer composition, comprising incorporating an antioxidant insoluble in an organic solvent and/or a stabilizer soluble in the organic solvent, in a slurry containing a polyether polymer and the organic solvent to disperse or dissolve the antioxidant and/or stabilizer; and then, removing the organic solvent. Also provided a polyether polymer composition comprising a polyether polymer particle, and an antioxidant insoluble in an organic solvent incapable of dissolving the polymer particle, and/or a stabilizer soluble in the organic solvent; and satisfying at least one of the following requirements: (1) most of the antioxidant is deposited on the surface of polymer particle; (2) the polymer has a gel content of not larger than 5% by weight; and (3) most of the stabilizer exists within the polymer particle.

Abstract: A material for solid polymer electrolyte, made of a polyether polymer having a moisture content in the range of 400 to 5,000 ppm by weight. A formed solid polymer electrolyte, which is made by mixing the material for solid polymer electrolyte together with an electrolyte salt compound soluble in the polyether polymer, has good ionic conductivity and high mechanical strength. A polyether polymer having a moisture content not larger than 0.04% by weight and a toluene-insoluble content not larger than 5% by weight. This polyether polymer gives a formed solid polymer electrolyte having a smooth surface.

Abstract: A material for solid polymer electrolyte, comprised of a polyether polymer having a moisture content in the range of 400 to 5,000 ppm by weight. A formed solid polymer electrolyte, which is made by mixing the material for solid polymer electrolyte together with an electrolyte salt compound soluble in the polyether polymer, has good ionic conductivity and high mechanical strength. A polyether polymer having a moisture content not larger than 0.04% by weight and a toluene-insoluble content not larger than 5% by weight. This polyether polymer gives a formed solid polymer electrolyte having a smooth surface.

Abstract: A process for producing a polyether polymer composition, comprising incorporating an antioxidant insoluble in an organic solvent and/or a stabilizer soluble in the organic solvent, in a slurry containing a polyether polymer and the organic solvent to disperse or dissolve the antioxidant and/or stabilizer; and then, removing the organic solvent. Also provided a polyether polymer composition comprising a polyether polymer particle, and an antioxidant insoluble in an organic solvent incapable of dissolving the polymer particle, and/or a stabilizer soluble in the organic solvent; and satisfying at least one of the following requirements: (1) most of the antioxidant is deposited on the surface of polymer particle; (2) the polymer has a gel content of not larger than 5% by weight; and (3) most of the stabilizer exists within the polymer particle.

Abstract: A composition for solid polymer electrolyte which comprises a polyether polymer and an electrolyte salt compound soluble in the polyether polymer; wherein said polyether polymer is either (1) a polyether polymer having a toluene insoluble content of not larger than 5 weight %, or (2) a polyether polymer having a Mooney viscosity of 3 to 190, which has been prepared by applying a shearing force under heated conditions using an extruder to a polyether polymer having a Mooney viscosity of 10 to 200 so that the Mooney viscosity is reduced by 5 or more. This composition exhibits good film-forming property, and gives a solid polymer electrolyte exhibiting good and uniform ionic conductivity, and having high mechanical strength and surface smoothness. The solid polymer electrolyte is suitable for batteries and capacitors, especially for a lithium ion secondary battery.

Abstract: A process for producing a polyether polymer by polymerizing a monomer having an oxirane group in the presence of a Lewis base having no active hydrogen such as, for example, a nitrile compound, a cyclic ether compound or an ester compound; and a polyether polymer produced by this process. Thus, a polyether polymer having a minimized amount of undesirable crosslinked product can be produced without reduction of polymerization activity.

Abstract: A composition for solid polymer electrolyte which comprises a polyether polymer and an electrolyte salt compound soluble in the polyether polymer; wherein said polyether polymer is either (1) a polyether polymer having a toluene insoluble content of not larger than 5 weight %, or (2) a polyether polymer having a Mooney viscosity of 3 to 190, which has been prepared by applying a shearing force under heated conditions using an extruder to a polyether polymer having a Mooney viscosity of 10 to 200 so that the Mooney viscosity is reduced by 5 or more. This composition exhibits good film-forming property, and gives a solid polymer electrolyte exhibiting good and uniform ionic conductivity, and having high mechanical strength and surface smoothness. The solid polymer electrolyte is suitable for batteries and capacitors, especially for a lithium ion secondary battery.