METHOD FOR PRODUCING LIQUID COMPOSITION, METHOD FOR PRODUCING COATING LIQUID FOR FORMING CATALYST LAYER, AND METHOD FOR PRODUCING MEMBRANE ELECTRODE ASSEMBLY

摘要

Provided are: a method for producing a liquid composition or a coating liquid for forming a catalyst layer which can make cracks less likely to occur when forming a solid polymer electrolyte membrane or a catalyst layer; and a method for producing a membrane electrode assembly which can make cracks less likely to occur when forming the catalyst layer or the solid polymer electrolyte membrane. This liquid composition is prepared by dispersing in a medium containing water and a hydrocarbon-based alcohol a polymer (x) having a structural unit having a ring structure and a structural unit having an ion exchange group, or a polymer (y) having any one or both of a structural unit having two ion-exchange groups in a pendant group and a structural unit having one ion exchange group in a short-chain pendant group, preparing a dispersion in which the concentration of the polymer (x) or the polymer (y) is 10-26 mass%, and mixing the dispersion and a fluorine-based solvent such that the total of the concentration of the polymer (x) or the polymer (y) and the concentration of the fluorine-based solvent becomes 12-35 mass%.