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

• US 9,500,927 B2
• Filed: 04/18/2016
• Issued: 11/22/2016
• Est. Priority Date: 08/08/2012
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Kloeppner, Leroy J., Giri, Punam, Lin, Rongguang, Theiste, David A.
• Primary Examiner(s): Ahvazi, Bijan
• Application Number:
  US15/131,907
• Publication Number:
  US 20160231634A1
• Time in Patent Office: 218 Days
• Field of Search: 252/62.2, 252/582, 252/583, 252/586, 359/265, 359/267, 359/270, 525/326.4
• US Class Current: 1/1
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: G02B 1/04 made of organic materials, e.g. plastics G02B1/08 takes precedence
• CPC Class Codes: G02B 5/23 Photochromic filters
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices

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.

Claims

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:

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

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

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.