Mitsui Chemicals, Inc.

Formosa Plastics Corporation

Junichi Ishikawa

Shoji Tamai

Yuichi Okawa

Takashi Kuroki

Naoshi Nagai

Satoko Fujiyama

Takeharu Isaki

Takehiko Omi

Masahiro Toriida

Tomoyuki Nakata

Masaki Shimizu

Kuniyuki Takamatsu

Shigeharu Fujii

Kazuhisa Miyazaki

Kazuaki Kikuchi

Kiyoshi Uzawa

Yuan Lin Min

Cheng Yen Kai

Chuan Chang Yi

This invention provides a binder for a fuel cell which has high adhesion, low methanol solubility, high methanol permeability and high proton conductivity, a composition for electrode formation, an electrode for a fuel cell, and a fuel cell using them. The binder is particularly suitable for a binder for a direct methanol type fuel cell which requires high proton conductivity. The binder for a fuel cell comprises a block copolymer which comprises a block having a repeating structural unit of a divalent aromatic group that contains a protonic acid group and a block having a repeating structural unit of a divalent aromatic group that does not contain a protonic acid group, and which has a glass transition temperature (Tg) of 180&#xb0; C. or less. In particular, it is preferable that the block copolymer has an ion exchange group equivalent of from 200 to 1,000 g/mole and a weight retention ratio of 90% or more as measured by immersion in a 64 weight % aqueous methanol solution at 25&#xb0; C. for 24 hours.

Binder for fuel cell, composition for forming electrode, electrode, and fuel cell using the electrode

The invention provides a crosslinkable aromatic resin having a protonic acid group and a crosslinkable group, suitable for electrolytic membranes and binders used in fuel cells, etc., and electrolytic polymer membranes, binders and fuel cells using the resin. The crosslinkable aromatic resin has a crosslinkable group, which is not derived from the protonic acid group and can form a polymer network without any elimination component. This resin exhibits excellent ion conductivity, heat resistance, water resistance, adhesion property and low methanol permeability. Preferably, the crosslinkable group is composed of a Cto Calkyl group directly bonded to the aromatic ring and/or an alkylene group having 1 to 3 carbon atoms in the main chain in which at least one carbon atom directly bonded to the aromatic ring bonds to hydrogen, and a carbonyl group, or a carbon-carbon double bond or triple bond. The aromatic resins such as aromatic polyethers, aromatic polyamides, aromatic polyimides, aromatic polyamideimides, aromatic polyazoles, etc., which contain such a crosslinkable group, are preferred as the crosslinkable aromatic resins having a protonic acid group and a crosslinkable group.

Crosslinkable aromatic resin having protonic acid group, and ion conductive polymer membrane, binder and fuel cell using the resin

Growing community of inventors

Ichihara, Japan

Junichi Ishikawa