The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 27, 2009
Filed:
Sep. 06, 2005
Toshimitsu Tachibana, Ibaraki, JP;
Soji Nishiyama, Ibaraki, JP;
Yozo Nagai, Ibaraki, JP;
Nitto Denko Corporation, Osaka, JP;
Abstract
A polymer electrolyte membrane for a polymer electrolyte fuel cell, that overcomes disadvantages of the conventional polymer ion-exchange membranes including fluorine-based polymer electrolyte membranes and can maintain cell characteristics even in use over a long period of time (e.g., several thousand hours). The polymer electrolyte membrane comprises a fluorine polymer substrate having grafted thereon monomers having sulfone groups as a cation-exchange group, wherein a main chain of the graft chain comprises a hydrocarbon or a partially fluorinated hydrocarbon, and sulfone groups or substituents having sulfone groups are bonded as a side chain, and wherein in element compositional ratio by ESCA, at least one surface of the polymer electrolyte membrane has O/S value of 5.0 or higher, and a surface element proportion of S is 0.4-5.0%.