Electrolyte membrane, method for producing the same, and membrane-electrode assembly for fuel cells that includes electrolyte membrane

Patent metadata

Field	Value
Publication number	US-10637087-B2
Application number	US-201616060787-A
Country	US
Kind code	B2
Filing date	Dec 9, 2016
Priority date	Dec 11, 2015
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The electrolyte membrane of the present disclosure includes a phase A forming a matrix phase, and a phase B. The phase B is continuous from a first principal surface of the electrolyte membrane to a second principal surface of the electrolyte membrane opposite to the first principal surface. The phase B includes a graft polymer having a main chain and a graft chain. The graft chain has a functional group having anion-exchange ability. The main chain preferably has no functional group having anion-exchange ability. The electrolyte membrane of the present disclosure can reliably maintain the function as a separation membrane even when decomposition reaction by a peroxide occurs.

First claim

The invention claimed is:

1. An electrolyte membrane comprising a phase A forming a matrix phase, and a phase B, wherein
the phase B is continuous from a first principal surface of the electrolyte membrane to a second principal surface of the electrolyte membrane opposite to the first principal surface,
the phase B comprises a graft polymer having a main chain and a graft chain, and
the graft chain has a functional group having anion-exchange ability.

2. The electrolyte membrane according to claim 1 , wherein
the matrix phase is in the form of a porous membrane, and
the phase B is formed to fill pores of the porous membrane.

3. The electrolyte membrane according to claim 1 , wherein the main chain of the graft polymer has no functional group having anion-exchange ability.

4. The electrolyte membrane according to claim 1 , wherein the main chain of the graft polymer has a polar group.

5. The electrolyte membrane according to claim 4 , wherein the polar group is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an ester group, an ether group, an amide group, and an amino group.

6. The electrolyte membrane according to claim 1 , wherein the graft chain has a structural unit containing a cyclic quaternary ammonium salt.

7. The electrolyte membrane according to claim 6 , wherein the structural unit containing a cyclic quaternary ammonium salt is a structural unit represented by the following formula (1):

wherein R 1 to R 4 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and X 1− is a halide ion, a hydroxide ion, or an anion of an organic or inorganic acid.

8. A membrane-electrode assembly for a fuel cell, comprising the electrolyte membrane according to claim 1 .

9. An electrolyte membrane production method for producing the electrolyte membrane according to claim 1 , comprising:
applying radiation to a membrane (I) having a phase A forming a matrix phase and a phase B′ containing a polymer; and
introducing a graft chain into the polymer contained in the phase B′ with the polymer serving as a main chain, and thereby forming a graft polymer having the main chain and the graft chain, wherein
the graft chain is a polymer chain derived from a polymerizable monomer containing a vinyl group and a functional group capable of having anion-exchange ability.

10. The electrolyte membrane production method according to claim 9 , further comprising forming the membrane (I) by filling pores of a porous membrane composing the phase A with the polymer composing the phase B′.

11. The electrolyte membrane production method according to claim 9 , wherein the main chain has no functional group capable of having anion-exchange ability.

12. The electrolyte membrane production method according to claim 9 , wherein the main chain has a polar group.

13. The electrolyte membrane production method according to claim 12 , wherein the polar group is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an ester group, an ether group, an amide group, and an amino group.

14. The electrolyte membrane production method according to claim 9 , wherein the graft chain has a structural unit containing a cyclic quaternary ammonium salt.

15. The electrolyte membrane production method according to claim 14 , wherein the structural unit containing a cyclic quaternary ammonium salt is a structural unit represented by the following formula (1):

wherein R 1 to R 4 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and X 1− is a halide ion, a hydroxide ion, or an anion of an organic or inorganic acid.

Assignees

• Nitto Denko Corp

Inventors

• Yamamoto Mizuki
• Matsuda Koso
• Nakano Takeshi

Classifications

• C08J5/2231

  based on macromolecular compounds obtained by reactions involving unsaturated carbon-to-carbon bonds · CPC title

• C08J5/2243

  obtained by introduction of active groups capable of ion-exchange into compounds of the type C08J5/2231 · CPC title

• C08J2323/06

  Polyethene · CPC title

• C08F261/04

  on to polymers of vinyl alcohol · CPC title

• H01M8/1072

  by chemical reactions, e.g. in situ polymerisation or in situ crosslinking · CPC title