To provide an electrolyte membrane for fuel cell that solves the largest problems in the fluorine-containing polymer ion-exchange membrane, that is a small ion-exchange capacity, in addition, poor water retention and poor resistance to oxidation that is serious defect in the fluorine-containing ion-exchange membrane to which hydrocarbon monomers are grafted.
As a base material, a crosslinking structure-bearing fluorine-containing polymer is used as a matrix. The fluorine-containing polymer is irradiated with a radioactive rays and a plurality of monomers are grafted or co-grafted and sulfonic acid groups are introduced into the graft chains. As a result, it has been found that a base membrane is deeply grafted into the core part by selecting a specific fluorine monomer and a variety of properties, e.g., the ion exchange capacity and the like becomes controllable within a suitably range.
MORITA YOSUKE
ASANO MASAHARU
SUWA TAKESHI
NISHIYAMA SOJI
NITTO DENKO CORP
Tadashi Masui
Yasushi Kobayashi
Akio Chiba
Hiroyuki Tomita
Shurin Sakurai