Color-stabilized electrochromic devices

• US 7,265,888 B2
• Filed: 04/01/2005
• Issued: 09/04/2007
• Est. Priority Date: 08/19/1999
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Guarr, Thomas F., Lomprey, Jeffrey R.
• Primary Examiner(s): Ben; Loha
• Application Number:
  US11/098,029
• Publication Number:
  US 20050280885A1
• Time in Patent Office: 886 Days
• Field of Search: 359/265, 359/274, 359/269, 359/275, 359/601, 359/602, 359/603, 204/450, 204/600, 204/606, 204/622, 204/485, 252/582, 252/583, 252/586
• US Class Current: 359/265
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte
• CPC Class Codes: G02F 2001/1502 complementary cell
• CPC Class Codes: G02F 2001/15145 the electrochromic layer comprises a mixture of anodic and cathodic compounds

Abstract

An electrochromic device comprising: (a) a first substantially transparent substrate having an electrically conductive material associated therewith; (b) a second substrate having an electrically conductive material associated therewith; (c) an electrochromic medium contained within a chamber positioned between the first and second substrates which comprises: (1) a solvent; (2) a cathodic electroactive material; (3) an anodic electroactive material, wherein at least one of the anodic and cathodic electroactive materials is electrochromic; and (4) a color-stabilizing additive, wherein the color-stabilizing additive is electroactive within a normal operating voltage of the electrochromic device; and (d) means associated with the color-stabilizing additive for maintaining an at least nearly colorless electrochromic device while the electrochromic device is in an open circuit and/or zero potential state relative to the same device without the color-stabilizing additive.

Claims

1. An electrochromic device, comprising:

(a) at least one substrate having an electrically conductive material associated therewith;

(b) an electrochromic medium which comprises a color-stabilizing additive; and

(c) wherein the electrochromic device exhibits an absolute value of Δ

b* of less than approximately 10.00 after being exposed to approximately 85 degrees centigrade for approximately 4,300 hours.

2. The electrochromic device according to claim 1, wherein the electrochromic medium comprises a cross-linked polymer matrix.

3. The electrochromic device according to claim 1, wherein the electrochromic device exhibits an absolute value of Δ

b* of less than approximately 5.00 after being exposed to approximately 85 degrees centigrade for approximately 4,300 hours.

4. The electrochromic device according to claim 1, wherein the electrochromic device exhibits an absolute value of Δ

b* of less than approximately 1.00 after being exposed to approximately 85 degrees centigrade for approximately 4,300 hours.

5. The electrochromic device according to claim 1, wherein the device is an electrochromic window.

6. An electrochromic device, comprising:

(a) at least one substrate having an electrically conductive material associated therewith;

(b) an electrochromic medium which comprises a color-stabilizing additive; and

(c) wherein the electrochromic device exhibits an absolute value of Δ

E of less than approximately 10.00 after being exposed to approximately 85 degrees centigrade for approximately 4,300 hours.

7. The electrochromic device according to claim 6, wherein the electrochromic medium comprises a cross-linked polymer matrix.

8. The electrochromic device according to claim 6, wherein the electrochromic device exhibits an absolute value of Δ

E of less than approximately 5.00 after being exposed to approximately 85 degrees centigrade for approximately 4,300 hours.

9. The electrochromic device according to claim 6, wherein the electrochromic device exhibits an absolute value of Δ

E of less than approximately 2.00 after being exposed to approximately 85 degrees centigrade for approximately 4,300 hours.

10. The electrochromic device according to claim 6, wherein the device is an electrochromic window.

11. An electrochromic device, comprising:

(a) at least one substrate having an electrically conductive material associated therewith;

(b) an electrochromic medium which comprises a color-stabilizing additive; and

(c) wherein the electrochromic device exhibits an absolute value of Δ

b* of less than approximately 6.00 after being exposed to ultraviolet radiation for approximately 2,000 hours while in a weatherometer.

12. The electrochromic device according to claim 11, wherein the electrochromic medium comprises a cross-linked polymer matrix.

13. The electrochromic device according to claim 11, wherein the electrochromic device exhibits an absolute value of Δ

b* of less than approximately 5.00 after being exposed to ultraviolet radiation for approximately 2,000 hours while in a weatherometer.

14. The electrochromic device according to claim 11, wherein the electrochromic device exhibits an absolute value of Δ

b* of less than approximately 2.00 after being exposed to ultraviolet radiation for approximately 2,000 hours while in a weatherometer.

15. The electrochromic device according to claim 11, wherein the device is an electrochromic window.

16. An electrochromic device, comprising:

(a) at least one substrate having an electrically conductive material associated therewith;

(b) an electrochromic medium which comprises a color-stabilizing additive; and

(c) wherein the electrochromic device exhibits an absolute value of Δ

E of less than approximately 9.00 after being exposed to ultraviolet radiation for approximately 2,000 hours while in a weatherometer.

17. The electrochromic device according to claim 16, wherein the electrochromic medium comprises a cross-linked polymer matrix.

18. The electrochromic device according to claim 16, wherein the electrochromic device exhibits an absolute value of Δ

E of less than approximately 5.00 after being exposed to ultraviolet radiation for approximately 2,000 hours while in a weatherometer.

19. The electrochromic device according to claim 16, wherein the electrochromic device exhibits an absolute value of Δ

E of less than approximately 2.00 after being exposed to ultraviolet radiation for approximately 2,000 hours while in a weatherometer.

20. The electrochromic device according to claim 16, wherein the device is an electrochromic window.