Patent ID: 10563021

Abstract:
To provide methods for producing a liquid composition, a coating liquid for a catalyst layer and a membrane electrode assembly, capable of making cracking less likely to occur at the time of forming a solid polymer electrolyte membrane or a catalyst layer. A copolymer having a structural unit represented by —[CF2—CF{(OCF2CFX)mOp(CF2)nSO3H}]— (wherein X: F or CF3, m: 1 to 3, p: 0 or 1, and n: an integer of 1 to 12) and a structural unit derived from tetrafluoroethylene, is dispersed in a medium containing water and a hydrocarbon-type alcohol (but not including a fluorinated solvent) to prepare a dispersion wherein the concentration of the copolymer is from 13 to 26 mass %, and the dispersion and a fluorinated solvent are mixed so that the sum of the concentration of the copolymer and the concentration of the fluorinated solvent becomes to be from 17 to 35 mass %, to prepare a liquid composition.