Patent Number: 7,785,751

Title: Production method of electrolyte membrane, electrolyte membrane and solid polymer fuel cell using same

Abstract: Disclosed is an electrolyte membrane which enables a fuel cell to have a high maximum output when used therein since it has high proton conductivity and high hydrogen gas impermeability. Also disclosed are a method for producing such an electrolyte membrane, and a solid polymer fuel cell using such an electrolyte membrane. A method for producing an electrolyte membrane including a step for impregnating a porous base with a solution containing a sulfonic acid group-containing vinyl monomer and then polymerizing the monomer is characterized in that 80% by mole or more of vinyl sulfonic acid having purity of 90% or more, and/or a salt thereof is contained as the sulfonic acid group-containing vinyl monomer, and the concentration of the vinyl sulfonic acid and/or a salt thereof in the solution is set at 35% by weight or more.

Inventors: Yamamoto; Kazushige (Ibaraki, JP), Emori; Hideyuki (Ibaraki, JP), Abe; Masao (Ibaraki, JP), Sho; Kinkou (Ibaraki, JP)

Assignee: Nitto Denko Corporation

International Classification: H01M 8/10 (20060101); B01J 39/20 (20060101)

Expiration Date: 8/31/12018