Ion-exchange membrane and method for producing same

Patent metadata

Field	Value
Publication number	US-9266069-B2
Application number	US-201013264233-A
Country	US
Kind code	B2
Filing date	Apr 13, 2010
Priority date	Apr 13, 2009
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

There is provided an ion-exchange membrane comprising an ion-exchange layer made of a cationic polymer and/or an anionic polymer and a supporting layer, wherein the ion-exchange layer is formed on the supporting layer by printing. Such an ion-exchange membrane exhibits excellent anti-organic fouling and low membrane resistance, thereby high efficient and long-time stable electrodialysis can be achieved. Formation of the ion-exchange layer as a charge-mosaic layer consisting of the cationic polymer domains and the anionic polymer domains provides a charge-mosaic membrane exhibiting excellent electrolyte permselectivity and mechanical strength.

First claim

The invention claimed is:

1. A ion exchange membrane, comprising :
an ion-exchange layer comprising [at least one selected from the group consisting of] a cationic and an anionic polymer; and
a supporting layer,
wherein the ion-exchange layer is formed on the supporting layer by printing;
wherein the cationic polymer comprises a block or graft copolymer comprising a polymer component formed by polymerization of a cationic monomer and a polyvinyl alcohol component, and the anionic polymer is a block or graft copolymer comprising a polymer component formed by copolymerization of an anionic monomer and a polyvinyl alcohol component;
and wherein the ion exchange layer is a charged-mosaic layer comprising a first domain of a cationic polymer and a second domain of the anionic polymer.

2. The membrane of claim 1 , wherein the cationic polymer is present and a cationic monomer content in the cationic polymer is 0.1 mol % or more.

3. The membrane of claim 1 , wherein the anionic polymer is present and an anionic monomer content in the anionic polymer is 0.1 mol % or more.

4. The membrane of claim 1 , wherein the ion-exchange layer is crosslinked.

5. The membrane of claim 1 , wherein the supporting layer is porous.

6. The membrane of claim 5 , wherein the supporting layer comprises a polyvinyl alcohol fiber assembly.

7. The membrane of claim 1 , wherein a ratio (A/B) of a thickness of the ion-exchange layer (A) to a thickness of the supporting layer (B) is 0.2 or less.

8. The membrane of claim 1 , wherein a first domain size of the first domain and a second domain size of the second domain are 300 μm or less, respectively, wherein the domain sizes are determined as average diameters of inscribed circles to first domains and second domains.

9. A method for producing an ion-exchange membrane, the method comprising:
(a) forming a ion-exchange layer on a supporting layer by printing,
wherein the ion-exchange membrane comprises the ion-exchange layer comprising a cationic polymer and an anionic polymer and the supporting layer,
wherein the cationic polymer comprises a block or graft copolymer comprising a polymer component formed by polymerization of a cationic monomer and a polyvinyl alcohol component, and the anionic polymer comprises a block or graft copolymer comprising a polymer component formed by polymerization of an anionic monomer and a polyvinyl alcohol component wherein the ion exchange layer is a charge-mosaic layer comprising a first domain of the cationic polymer and a second domain of the anionic polymer.

10. The method of claim 9 , wherein the printing is ink-jet printing, screen printing, transfer printing, or dispenser printing.

11. The method of claim 9 , further comprising:
(b) crosslinking the ion-exchange layer after the forming (a).

12. The method of claim 9 , further comprising:
(c) annealing or hot-pressing the ion-exchange layer after the forming (a).

13. The method of claim 12 , wherein the crosslinking is subjected after the annealing or the hot pressing.

Assignees

• Higa Mitsuru
• Jikihara Atsushi
• Kobayashi Kenichi
• Fujiwara Naoki
• Univ Yamaguchi
• Kuraray Co

Inventors

• Higa Mitsuru
• Jikihara Atsushi
• Kobayashi Kenichi
• Fujiwara Naoki

Classifications

• B01D61/44

  Ion-selective electrodialysis · CPC title

• B01D69/10 Primary

  Supported membranes; Membrane supports · CPC title

• C08J2329/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08J5/2206

  based on organic and/or inorganic macromolecular compounds · CPC title

• B01D67/0013

  Casting processes · CPC title