Abstract: A tetrafluoroethylene copolymer comprising 30 to 81 mole % of tetrafluoroethylene and a 70 to 19 mole % of at least one other monomer, and having terminal carbonate groups at polymer chain ends, which has a melt flow rate of 0.1 to 100 g/10 min. at 200° C. under a load of 5 kg, and a melting point of 90 to 200° C., a laminate comprising a layer of the above tetrafluoroethylene copolymer, and a layer of other material, and a surface film or a transparent filler material for a solar cell, which comprises the above tetrafluoroethylene copolymer is disclosed. The fluororesin can be firmly adhered directly to other materials such as resins, metals, glass, crystalline silicon, polycrystalline silicon and amorphous silicon, while maintaining characteristics such as chemical resistance, solvent resistance, non-tackiness, electrical insulation properties, stain-proofing properties and flame retardance.

Abstract: A tetrafluoroethylene copolymer comprising 30 to 81 mole % of tetrafluoroethylene and a 70 to 19 mole % of at least one other monomer, and having terminal carbonate groups at polymer chain ends, which has a melt flow rate of 0.1 to 100 g/10 min. at 200° C. under a load of 5 kg, and a melting point of 90 to 200° C., a laminate comprising a layer of the above tetrafluoroethylene copolymer, and a layer of other material, and a surface film or a transparent filler material for a solar cell, which comprises the above tetrafluoroethylene copolymer is disclosed. The fluororesin can be firmly adhered directly to other materials such as resins, metals, glass, crystalline silicon, polycrystalline silicon and amorphous silicon, while maintaining characteristics such as chemical resistance, solvent resistance, non-tackiness, electrical insulation properties, stain-proofing properties and flame retardance.

Abstract: A tetrafluoroethylene copolymer comprising 30 to 81 mole % of tetrafluoroethylene and a 70 to 19 mole % of at least one other monomer, and having terminal carbonate groups at polymer chain ends, which has a melt flow rate of 0.1 to 100 g/10 min. at 200° C. under a load of 5 kg, and a melting point of 90 to 200° C. This copolymer can be firmly adhered directly to other materials such as general-purpose resins while maintaining the good properties of fluororesins such as chemical resistance, weather resistance, solvent resistance, non-tackiness, electrical insulation, stain-proofing properties, and flame retardance, molded at a lower temperature than conventional fluororesins, and heat bonded or co-extruded with general-purpose resins having low heat resistance.

Abstract: To provide a binder for secondary battery using non-aqueous electrolyte which is soluble in usual organic solvents, does not swell in a non-aqueous electrolyte and besides enhances battery performance. As the binder, a copolymer comprising 50 to 80% by mole of vinylidene fluoride, 17 to 50% by mole of tetrafluoroethylene and less than 3% by mole of a monomer copolymerizable therewith is used.

Abstract: To provide a water-repelling agent for batteries which comprises an aqueous dispersion or organosol containing fine particles having an average particle size of from 0.05 to 1 .mu.m and made of a tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer and/or a non-fibril-forming tetrafluoroethylene polymer, is obtained without use of a powder of a fluorine-containing resin as it is, can enhance chemical resistance, heat resistance and water repellency particularly more effectively without being fibrillated even if mixed with electrode materials and is excellent in workability, and to provide a battery which is produced by using the water-repelling agent for batteries and is excellent in cycle life and internal pressure characteristics.

Abstract: A binder for use in batteries which is in the form of an aqueous or nonaqueous dispersion or a powder comprising core-shell composite fine particles 0.05 to 1 .mu.m in mean particle size and each having a core of a fibrillating polytetrafluoroethylene and a shell of a nonfibrillating polymer, the composite fine particles having a core-to-shell ratio by weight of 98:2 to 50:50, and electrode compositions and batteries incorporating the binder.

Abstract: A mastication measurement apparatus is provided with a displacement detecting element such as a piezoelectric element and a holder which keeps the detecting element in close contact with a part of the side of one's face. The apparatus is capable of processing electric signals produced by the detecting element to measure the number of masticating cycles, number of masticating cycles per unit time, a maximum value of the mastication force and the mastication energy, and is also capable of checking whether a denture is matched to a subject by detecting noises included in the output of the detecting element. In accordance with the invention, it is also possible to determine which teeth are not used during the mastication of food by attaching the detecting elements to both sides of a face and comparing the outputs from both detecting elements.

Abstract: The present invention provides an impression composition of the alginate type which comprises (a) an alginate, (b) calcium sulfate and/or lead silicate, and (c) a filler as its main components and which is characterized in that the alginate component comprises in combination an alginate having a distribution of molecular weights in a lower range and an alginate having a distribution of molecular weights in a higher range.

Abstract: A polymeric dielectric material comprising a terpolymer which comprises 30 to 90% by mole of VdF, 5 to 70% by mole of TrFE and 0.1 to 20% by mole of HFP, having large permittivity, which is improved by heat treatment.

Abstract: A process for preparing a polymeric piezoelectric material which comprises a vinylidene fluoride containing polymer, comprising applying at least two cycles of alternate electric field except a rectangular wave to the material to polarize it, by which process, the polymeric piezoelectric material is prepared at a low temperature for a short time.

Abstract: A process for preparation of a polymeric piezo-electric material and material prepared by said process are described, wherein said process comprises polarizing a polymeric piezo-electric material by a polarization treatment which comprisescooling a vinylidene fluoride-trifluoroethylene copolymer from a temperature higher than the phase transition temperature of said copolymer which exists between room temperature and the melting point of said copolymer, and either maintaining the temperature range at which said copolymer possesses a maximum in dielectric constant occurs, or cooling gradually through said temperature range, while applying an electric field at least within said temperature range.