Abstract: A polymer electrolytic material has excellent proton conductivity and excellent fuel shutting property, and accordingly provide a polymer electrolytic fuel cell with a high efficiency. This polymer electrolytic material has an unfreezable water ratio Rw1 defined by the following expression (S1) in a range of 20 to 100% by weight in hydrated state: Rw1=[Wnf/Wfc+Wnf)]×100??(S1) in which Wnf represents the unfreezable water content per 1 g of the polymer electrolytic material in dry state and Wfc represents the low freezing point water content per 1 g of the polymer electrolytic material in dry state.

Abstract: It is an object of the present invention to provide a method of producing a membrane electrode assembly using an interface resistance reducing composition which can simply reduce the resistance of the interface between an electrode and an electrolyte membrane in a short time at low temperatures at low pressure without polimerization while maintaining an effect of suppressing a fuel crossover even with an electrolyte membrane having high heat resistance, high strength, a high tensile elastic modulus and a low water content.

Abstract: The present invention relates to a method for producing a polymer electrolyte molded article, which comprises forming a polymer electrolyte precursor having a protective group and an ionic group, and deprotecting at least a portion of protective groups contained in the resulting molded article to obtain a polymer electrolyte molded article. According to the present invention, it is possible to obtain a polymer electrolyte material and a polymer electrolyte molded article, which are excellent in proton conductivity and are also excellent in fuel barrier properties, mechanical strength, physical durability, resistance to hot water, resistance to hot methanol, processability and chemical stability. A polymer electrolyte fuel cell using a polymer electrolyte membrane, polymer electrolyte parts or a membrane electrode assembly can achieve high output, high energy density and long-term durability.

Abstract: The present invention is to provide a polymer electrolyte material realizing excellent proton conductivity even when it comes into direct contact with liquid fuel at high temperature and high concentration, and excellent fuel barrier property and mechanical strength, as well as to provide a polymer electrolyte fuel cell of high efficiency. A polymer electrolyte material of the present invention is characterized in that fraction Rw of non-freezing water shown by the equation (S1) below is 75 to 100% by weight, and an ionic group is included, in a moisture state taken out after 12-hour immersion in 1 to 30% by weight methanol aqueous solution at 40 to 80° C. and then 24-hour immersion in pure water at 20°: Rw=[Wnf/(Wfc+Wnf)]×100??(S1) (wherein, Wnf represents an amount of non-freezing water per 1 g of dry weight of polymer electrolyte material, Wfc represents an amount of lower-melting point water per 1 g of dry weight of polymer electrolyte material).

Abstract: The present invention relates to a polymer electrolyte that provides high proton conductivity and low fuel crossover at the same time, as well as a member using the same. The embodiments of the invention can achieve high output and high energy density in the form of a polymer electrolyte fuel cell. A polymer electrolyte comprising a proton conductive polymer (A) and a polymer (B) which is different from (A) wherein a ratio of the amount of unfreezable water, represented by formula (S1), in said polymer electrolyte is no less than 40 wt % and no greater than 100 wt % is disclosed. The ratio of amount of unfreezable water (S1)=(amount of unfreezable water)/(amount of low melting point water+amount of unfreezable water)×100 (%).

Abstract: The invention aims to provide a polymer electrolytic material excellent in proton conductivity and also excellent in fuel shutting property, and accordingly provide a polymer electrolytic fuel cell with a high efficiency. That is, the invention provides a polymer electrolytic material having an unfreezable water ratio Rw1 defined by the following expression (S1) in a range of 20 to 100% by weight in hydrated state: Rw1=[Wnf/(Wfc+Wnf)]×100 ??(S1) in which Wnf represents the unfreezable water content per 1 g of the polymer electrolytic material in dry state and Wfc represents the low freezing point water content per 1 g of the polymer electrolytic material in dry state.