Ion exchange membrane, method for producing ion exchange membrane, and electrolyzer

Patent metadata

Field	Value
Publication number	US-10865282-B2
Application number	US-201816219100-A
Country	US
Kind code	B2
Filing date	Dec 13, 2018
Priority date	Dec 18, 2017
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

An ion exchange membrane includes: a membrane main body including a fluorine-containing polymer having an ion exchange group; and a coating layer arranged on at least one face of the membrane main body; wherein the coating layer includes inorganic particles and a binder, a mass ratio of the binder to the total mass of the inorganic particles and the binder in the coating layer is more than 0.3 and 0.9 or less, and a surface roughness of the coating layer is 1.20 μm or more.

First claim

The invention claimed is:

1. An ion exchange membrane comprising:
a membrane main body comprising a fluorine-containing polymer having an ion exchange group; and
a coating layer arranged on at least one face of the membrane main body;
wherein
the coating layer comprises inorganic particles and a binder, wherein
the average particle size of the inorganic particles is 0.90 μm or more and 2 μm or less, and
a mass ratio of the binder to a total mass of the inorganic particles and binder in the coating layer is more than 0.3 and 0.9 or less, and a surface roughness of the coating layer is 1.20 μm or more.

2. The ion exchange membrane according to claim 1 ,
wherein the inorganic particles are particles comprising at least one mineral selected from the group consisting of oxides of Periodic Table Group IV elements, nitrides of Periodic Table Group IV elements, and carbides of Periodic Table Group IV elements.

3. The ion exchange membrane according to claim 1 ,
wherein the inorganic particles are particles of zirconium oxide.

4. The ion exchange membrane according to claim 1 ,
wherein the membrane main body comprises:
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 formula (1):
2.0≤B/A≤5.0  (1)

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.

5. A method for producing the ion exchange membrane according to claim 1 , comprising
spraying a coating solution comprising inorganic particles, a binder, and a solvent by a spray system, followed by
drying thereof to form a coating layer on a surface of the membrane main body, wherein an average droplet size during the spraying is 100 μm or less.

6. The method for producing the ion exchange membrane according to claim 5 , wherein a surface temperature of the membrane main body during the drying is 40° C. or more and equal to or less than a boiling point of the solvent.

7. A method of using the ion exchange membrane according to claim 1 , comprising using the ion exchange membrane in an electrolyzer.

Assignees

• Asahi Chemical Ind

Inventors

• Okamoto Koji
• Takahashi Kazuya

Classifications

• B01D69/1216

  Three or more layers · CPC title

• B01D69/1213

  Laminated layers · CPC title

• B01D69/1212

  Coextruded layers · CPC title

• B01D71/024

  Oxides · CPC title

• C25B9/19 Primary

  with diaphragms · CPC title