BINDER FOR ELECTRODE CATALYST LAYER FORMATION AND FUEL BATTERY

PROBLEM TO BE SOLVED: To provide a binder for formation of an electrode catalyst layer of a membrane-electrode assembly used for a fuel battery superior in power generation performance.SOLUTION: A binder for formation of an electrode catalyst layer of a membrane-electrode assembly comprises: a polymer including a structural unit expressed by the formula (1). (R1 to R4 independently represent H, a cyano group, or a substituted/unsubstituted hydrocarbon group; R5 represents a halogeno group or a substituted/unsubstituted hydrocarbon group; "a" is an integer of 0-5; R5's are independent of each other if "a" is two or larger integer; "m" is 1-99 mol%; and Xis an anion.)SELECTED DRAWING: None 【課題】発電性能に優れる燃料電池に用いる膜電極接合体の電極触媒層形成用バインダーの提供。【解決手段】式（１）で示される構造単位を含有するポリマーを含む膜電極接合体の電極触媒層形成用バインダー。（Ｒ１−４は各々独立にＨ、シアノ基、又は置換／未置換の炭化水素基；Ｒ５はハロゲノ基又は置換／未置換の炭化水素基；ａは０〜５の整数；ａが２以上の場合、Ｒ５は各々独立している；ｍは１〜９９のモル％；Ｘ-は陰イオン）【選択図】なし