Patent ID: 7220508

Claim:
A solid polymer electrolyte material made of a copolymer comprising a repeating unit based on a fluoromonomer A which gives a polymer having an alicyclic structure in its main chain by radical polymerization, and a repeating unit based on a fluoromonomer B of the following formula (1): CF 2 ═CF(R f ) j SO 2 X (1) wherein j is 0 or 1, X is a fluorine atom, a chlorine atom or OM {wherein M is a hydrogen atom, an alkali metal atom or a group of NR 1 R 2 R 3 R 4 (wherein each of R 1 , R 2 , R 3 and R 4 which may be the same or different, is a hydrogen atom or a monovalent organic group)}, and R f is a C 1-20 polyfluoroalkylene group having a straight chain or branched structure which may contain ether oxygen atoms.