Electrochromic polyelectrolyte gel medium having improved creep resistance and associated electrochromic device

Patent metadata

Field	Value
Publication number	US-9500927-B2
Application number	US-201615131907-A
Country	US
Kind code	B2
Filing date	Apr 18, 2016
Priority date	Aug 8, 2012
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

An electrochromic device including a first substantially transparent substrate having an electrically conductive material associated therewith; a second substrate having an electrically conductive material associated therewith; and an electrochromic medium contained within a chamber positioned between the first and second substrates which includes: at least one solvent; at least one anodic electroactive material; at least one cathodic electroactive material; wherein at least one of the anodic and cathodic electroactive materials is electrochromic; and a creep resistant crosslinked polyelectrolyte gel matrix.

First claim

What is claimed and desired to be secured by Letters Patent of the United States is:

1. An electrochromic medium comprising:
a cross-linked polyelectrolyte gel matrix comprising:
a polymeric backbone comprising first ionic groups of a same polarity;
counterions with opposite polarity to the first ionic groups; and
a crosslinking moiety;

wherein the first ionic groups are selected from a group consisting of viologen moieties, ammonium moieties, one or more pyridinium groups and one or more imidazolium groups.

2. The electrochromic medium of claim 1 , wherein the electrochromic medium exhibits a greater resistance to creep relative to an electrochromic medium comprising a non-ionic gel matrix at the same concentration.

3. The electrochromic medium of claim 1 further comprising:
a solvent;
an anodic electroactive material; and
a cathodic electroactive material; and
wherein at least one of the anodic and cathodic electroactive materials is electrochromic.

4. The electrochromic medium of claim 3 further comprising an ultraviolet stabilizer.

5. The electrochromic medium of claim 3 further comprising anodic and cathodic color-stabilizing redox buffers.

6. The electrochromic medium of claim 1 , wherein the polymeric backbone comprises ammonium groups.

7. The electrochromic medium of claim 6 , wherein the ammonium groups are trimethylammonium groups.

8. The electrochromic medium of claim 1 , wherein the polymeric backbone comprises the polymerization product of 2-(methylacryloyloxy)ethyl trimethylammonium tetrafluoroborate.

9. The electrochromic medium of claim 1 , wherein the polymeric backbone comprises the polymerization product of 2-(methylacryloyloxy)ethyl trimethylammonium tetrafluoroborate and 2-hydroxyethylmethacrylate.

10. The electrochromic medium of claim 1 , wherein the crosslinking moiety comprises one or more second ionic groups and counterions with opposite polarity to the second ionic groups.

11. The electrochromic medium of claim 10 , wherein the second ionic groups and counterions with opposite polarity to the second ionic groups of the crosslinking moieties are selected from a group consisting of viologen moieties, ammonium moieties, one or more pyridinium groups and one or more imidazolium groups.

12. The electrochromic medium of claim 11 , wherein the crosslinking moieties comprise a viologen moiety of Formula I:

Y 1 and Y 2 are independently selected from the group comprising a direct bond, an alkylene, arylene, alkarylene, aralkylene, ether, or polyether chain containing 1 to 40 carbon atoms.

13. The electrochromic medium of claim 11 , wherein the crosslinking moieties comprise a viologen moiety of formula

wherein

represents a point of connection to the polymeric backbone.

14. The electrochromic medium of claim 1 , wherein the crosslinking moieties comprise the polymerization product of [2-(methacryloyloxy)ethyl]trimethylammonium tetrafluoroborate.

15. The electrochromic medium of claim 1 , wherein the crosslinking moieties comprise the polymerization product of [2-(methacryloyloxy)ethyl]trimethylammonium tetrafluoroborate.

16. The electrochromic medium of claim 1 , wherein the crosslinking moieties comprise

wherein

represents a point of connection to the polymeric backbone.

17. The electrochromic medium of claim 1 , wherein the polymeric backbone comprises a polyamide, a polyimide, a polycarbonate, a polyester, a polyether, a polymethacrylate, a polyacrylate, a polysilane, a polysiloxane, a polyvinylacetate, a polymethacrylonitrile, a polyacrylonitrile, a polyvinylphenol, a polyvinylalcohol, a polyvinylidenehalide, or a co-polymer or combination of any two or more thereof.

18. The electrochromic medium of claim 17 , wherein the polymeric backbone comprises a polyvinylphenol, a polyvinylalcohol, or a co-polymer or combination thereof.

19. An electrochromic device comprising the electrochromic medium of claim 1 .

20. The electrochromic device of claim 19 which is a mirror, an architectural window, or an aircraft window.

Assignees

• Gentex Corp

Inventors

• Kloeppner Leroy J
• Giri Punam
• Lin Rongguang
• Theiste David A

Classifications

• G02F1/157 Primary

  Structural association of cells with optical devices, e.g. reflectors or illuminating devices · CPC title

• B60R1/088

  using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors · CPC title

• G02F1/1503 Primary

  caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions · CPC title

• G02B5/23

  Photochromic filters · CPC title

• G02B1/04

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title