Patent ID: 7651802

Claim:
A polymer electrolyte, which comprises a copolymer comprising constituent units with a protonic acid group represented by Formula (1) below and constituent units without a protonic acid group represented by Formula (6) below: Ar 1 —Y—Ar 2 —Y (1) wherein Ar 1 is a binding unit represented by Formula (2) below; Ar 2 is a binding unit represented by Formula (3) below; and Y is an oxygen or a sulfur atom; wherein X is a divalent electron-withdrawing group; n is an integer of from 0 to 4; p and q are each an integer of from 0 to 4 (with the proviso that p+q≧1); Rs are each a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an aryl group or a nitrile group; and As are each a group represented by Formula (5a) or (5b) below; wherein Z is a direct bond, —O—, —S—, —CO—, —SO 2 —, —[C(R′) 2 ] g — (wherein R′ is a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group or an aryl group, and g is an integer of from 1 to 8) or a binding unit represented by any of Formulae (4a) to (4d) below; m is an integer of from 0 to 4; t and u are each an integer of from 0 to 4; and Rs and As are as defined in Formula (2); wherein f is an integer of from 0 to 4; h, k and l are each an integer of from 0 to 5; and Rs and As are as defined in Formula (2); wherein W is a divalent electron-withdrawing group; S is a protonic acid group; i is an integer of from 1 to 5; j is an integer of from 1 to 7; and Rs are as defined in Formula (2); Ar 3 —Y—Ar 4 —Y (6) wherein Ar 3 is a binding unit represented by Formula (7) below; Ar 4 is a binding unit represented by Formula (8) below; and Y is an oxygen or a sulfur atom; wherein X is a divalent electron-withdrawing group; r is an integer of from 0 to 4; and R 1 to R 8 are the same or different from one another and are each a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an aryl group or a nitrile group; wherein Q is a direct bond, —O—, —S—, —CO—, —SO 2 —, —[C(R′) 2 ] g — (wherein R′ is a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group or an aryl group, and g is an integer of from 1 to 8) or a binding unit represented by any of Formulae (9a) to (9d) below; s is an integer of from 0 to 4; and R 9 to R 16 are the same or different from one another and are each a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an aryl group or a nitrile group; wherein R 17 to R 44 are the same or different from one another and are each a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an aryl group or a nitrile group.