Ion exchange membrane and electrolyzer

Patent metadata

Field	Value
Publication number	US-11047056-B2
Application number	US-201716086827-A
Country	US
Kind code	B2
Filing date	Nov 24, 2017
Priority date	Jan 27, 2017
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

An ion exchange membrane includes a layer S including a fluorine-containing polymer having a sulfonic acid group, a layer C including a fluorine-containing polymer having a carboxylic acid group, and a plurality of strengthening materials arranged inside the layer S and functioning as at least one of reinforcement yarn and sacrifice yarn. A and B satisfy following formulas:

B ≤240 μm  (1)

2.0≤ B/A ≤5.0  (2)
wherein, when the ion exchange membrane is viewed from the top surface, A represents an average cross-sectional thickness of the membrane measured in pure water for a region, in which the strengthening materials do not exist, and B represents an average cross-sectional thickness of the membrane measured in pure water for a region, in which strands of the reinforcement yarn overlap with each other, and in a region, in which the reinforcement yarn overlaps with the sacrifice yarn.

First claim

The invention claimed is:

1. An ion exchange membrane comprising:
a layer S comprising a fluorine-containing polymer having a sulfonic acid group;
a layer C comprising a fluorine-containing polymer having a carboxylic acid group; and
a plurality of strengthening materials arranged inside the layer S and functioning as at least one of reinforcement yarn and sacrifice yarn;
wherein A and B, both of which are defined below, satisfy following formulas (1) and (2):
B≤ 240 μm  (1)

2.0≤ B/A≤ 5.0  (2)

wherein, when the ion exchange membrane is viewed from a top surface,
A represents an average cross-sectional thickness of the membrane measured in pure water for a region, in which the strengthening materials do not exist, and
B represents an average cross-sectional thickness of the membrane measured in pure water for a region, in which strands of the reinforcement yarn overlap with each other, and for a region, in which the reinforcement yarn overlaps with the sacrifice yarn.

2. The ion exchange membrane according to claim 1 , wherein A and C1 which is defined below satisfy following formula (3):
40 μm≤ A ≤C1  (3)

wherein C1 represents a maximum value of a distance between a surface of the layer S and reinforcement yarn most distant from the surface of the layer S, the distance being measured in pure water and in a direction of the thickness of the membrane in the region, in which strands of the reinforcement yarn overlap with each other.

3. The ion exchange membrane according to claim 1 , wherein
the layer S has a continuous hole therein and a plurality of opening portions on a surface thereof, and
a ratio of a total area of the opening portions to an area of the surface of the layer S is 0.4 to 15%.

4. The ion exchange membrane according to claim 1 , wherein a surface of the layer S has raised portions having a height of 20 μm or more, when viewed from a cross section.

5. The ion exchange membrane according to claim 4 , wherein an arrangement density of the raised portions is 20 to 1500 raised portions/cm 2 .

6. An electrolyzer comprising the ion exchange membrane according to claim 1 .

7. A method for producing the ion exchange membrane according to claim 1 .

Assignees

• Asahi Chemical Ind

Inventors

• Ohashi Ryuji
• Kameyama Hiroyuki
• Morikawa Takuya

Classifications

• C08J2327/24

  halogenated · CPC title

• C08J2327/18

  Homopolymers or copolymers of tetrafluoroethylene · CPC title

• C08J5/2281

  fluorine containing heterogeneous membranes · CPC title

• C08J5/2243

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

• C08J5/2237

  containing fluorine · CPC title