| abstract |
To provide a method for producing a composition, comprising the following step A: subjecting a composition comprising water and a fluoropolymer to ultrafiltration, microfiltration or dialysis membrane treatment, or a combination thereof, the above-mentioned fluoropolymer The compound is a polymer including the structural unit M3 derived from the monomer represented by the general formula (1). CX 2 =CY(-CZ 2 -O-Rf-A)(1) (wherein, X is the same or different, is -H or -F, Y is -H, -F, alkyl or fluorine-containing alkyl, Z is the same or different, and is -H, -F, alkyl or fluoroalkyl. Rf is a fluorine-containing alkylene group with 1 to 40 carbon atoms, or a fluorine-containing alkylene group with an ether bond with 2 to 100 carbon atoms. Fluoroalkylene. A is -COOM, -SO 3 M, -OSO 3 M or -C(CF 3 ) 2 OM (M is -H, metal atom, -NR 7 4 , imidazole with or without substituents Onium, pyridinium with or without substituent or phosphonium with or without substituent, R 7 is H or an organic group). Wherein, at least one of X, Y and Z contains a fluorine atom.). |