High-molecular-weight electrolyte and use thereof

1. A polymer electrolyte, containing, in its main chain, a repeating unit represented by the following formula (1) and at least one of the unit represented by the following formula (2) and the unit represented by the following formula (3):

wherein Ar represents a benzene or naphthalene ring; X represents a proton or a cation; a and b are each an integer of 0 to 4, and the sum of a's and b's is 1 or greater; m is 1; and n is 1,

wherein Ar, m, and n are defined as in the formula (1); Y 1 is SO 2 , C(CH 3 ) 2 , or C(CF 3 ) 2 ; and Z represents a direct bond, oxygen, or sulfur,

wherein Ar, m, and n are defined as in the formula (1); Y 2 is CO, SO 2 , C(CH 3 ) 2 , or C(CF 3 ) 2 ; and Z represents a direct bond, oxygen, or sulfur,

wherein the aromatic rings of formula (1) and at least one of formulas (2) and (3) are bonded by a C—C direct bond, and

0≤B/(A+B)≤0.95 wherein A is the number of moles of the unit represented by the formula (2) and B is the number of moles of the unit represented by the formula (3).

2. The polymer electrolyte according to claim 1 ,

wherein the repeating unit represented by the formula (1) is a unit represented by the following formula (4):

wherein X, a, b, m, and n are defined as in the formula (1).

3. The polymer electrolyte according to claim 1 ,

wherein the unit represented by the formula (2) is a unit represented by the following formula (5):

wherein Y 1 and Z are defined as in the formula (2), and

the unit represented by the formula (3) is a unit represented by the following formula (6):

wherein Y 2 is defined as in the formula (3) and Z is defined as in the formula (2).

4. The polymer electrolyte according to claim 1 , further containing, in its main chain, a unit represented by the following formula (7):

wherein Ar, X, a, b, m, and n are defined as in the formula (1); Z is defined as in the formula (2);

and W is a direct bond, CO, SO 2 , C(CH 3 ) 2 , or C(CF 3 ) 2 .

5. The polymer electrolyte according to claim 1 ,

wherein the total content of the repeating unit represented by the formula (1) is 20% by weight or more of the whole.

6. The polymer electrolyte according to claim 1 , which comprises a block copolymer containing a sulfonate-containing hydrophilic segment and a sulfonate-free hydrophobic segment,

the sulfonate-containing hydrophilic segment containing the repeating unit represented by the formula (1), wherein the sulfonate-free hydrophobic segment contains the unit represented by the formula (2) and/or the unit represented by the formula (3).

7. The polymer electrolyte according to claim 6 ,

wherein the repeating unit represented by the formula (1) accounts for 20% by weight or more of the sulfonate-containing hydrophilic segment.

8. The polymer electrolyte according to claim 6 ,

wherein the sulfonate-containing hydrophilic segment contains, in its main chain, a repeating unit represented by the following formula (8):

wherein Ar, X, and m are defined as in the formula (1).

9. The polymer electrolyte according to claim 1 ,

wherein the polymer electrolyte has an ion exchange capacity of 1.0 to 4.0 meq/g.

10. A polymer electrolyte membrane, comprising

the polymer electrolyte according to claim 1 .

11. A membrane electrode assembly, comprising

the polymer electrolyte membrane according to claim 10 .

12. A polymer electrolyte fuel cell, comprising

the polymer electrolyte membrane according to claim 10 .

13. A polymer electrolyte fuel cell, comprising

the membrane electrode assembly according to claim 11 .

14. The polymer electrolyte according to claim 6 ,

wherein the sulfonate-containing hydrophilic segment further contains, in its main chain, a unit represented by the following formula (7):

wherein Ar, X, a, b, m, and n are defined as in the formula (1); Z is defined as in the formula (2);

and W is a direct bond, CO, SO 2 , C(CH 3 ) 2 , or C(CF 3 ) 2 .