ELECTROCHROMIC ELEMENTS USING ANTIOXIDANTS TO SUPPRESS SELF-DISCHARGING

• US 20090225393A1
• Filed: 02/18/2009
• Published: 09/10/2009
• Est. Priority Date: 02/19/2008
• Status: Active Grant

• Current Assignee: Econtrol-Glas GmbH & Co. KG
• Original Assignee: Econtrol-Glas GmbH & Co. KG
• Inventors: Jodicke, Dirk
• Granted Patent: US 7,916,379 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte

Abstract

The invention relates to the use of antioxidants of different kinds and concentrations in electrochromic elements having an ion conducting component to suppress self-discharging. In comparison to electrochromic elements known from prior art, electrochromic elements according to the invention show a significantly smaller increase in transmissivity for a period of time after the electric current necessary to decrease transmissivity is switched off. The use of sterically hindered amines and/or 1,3,5-trisubstituted phenols has proven particularly effective for this purpose.

Claims

1. A process for suppressing self-discharging in an electrochromic element, comprising:

adding at least one antioxidant with a first concentration to an electrochromic element having an ion conducting component.

2. A process for suppressing self-discharging in an electrochromic element according to claim 1, wherein the at least one antioxidant is added to the ion conducting component.

3. A process for suppressing self-discharging in an electrochromic element according to claim 1, wherein the at least one antioxidant comprises at least one sterically hindered amine.

4. A process for suppressing self-discharging in an electrochromic element according to claim 3, wherein the at least one sterically hindered amine is di-tert-butylamine, 2,2,6,6-tetramethylpiperidine, or a derivative of either.

5. A process for suppressing self-discharging in an electrochromic element according to claim 1, wherein the at least one antioxidant comprises at least one 1,3,5-trisubstituted phenol of a first concentration and at least one sterically hindered amine of a second concentration.

6. A process for suppressing self-discharging in an electrochromic element according to claim 5, wherein the at least one 1,3,5-trisubstituted phenol is 1,5-tert-butyl-3-methyl phenol or 1,3,5-tri-tert-butyl phenol.

7. A process for suppressing self-discharging in an electrochromic element according to claim 3, wherein the at least one antioxidant contains approximately 0.1-3.0% by weight of the at least one sterically hindered amine.

8. A process for suppressing self-discharging in an electrochromic element according to claim 5, wherein the at least one antioxidant contains approximately 0.1-2.0% by weight of the at least one 1,3,5-trisubstituted phenol.

9. An electrochromic element comprising:

first and second electrodes that are substantially optically transparent and electrically conducting;

first and second electrochromic layers; and

an ion conducting component containing an antioxidant.

10. An electrochromic element according to claim 9, wherein the antioxidant comprises a sterically hindered amine.

11. An electrochromic element according to claim 10, wherein the sterically hindered amine is di-tert-butylamine, 2,2,6,6-tetramethylpiperidine, or a derivative of either.

12. An electrochromic element according to claim 10, wherein the antioxidant contains approximately 0.1-3.0% by weight of the sterically hindered amine.

13. An electrochromic element according to claim 9, wherein the antioxidant comprises a 1,3,5-trisubstituted phenol of a first concentration and a sterically hindered amine of a second concentration.

14. An electrochromic element according to claim 13, wherein the 1,3,5-trisubstituted phenol is 1,5-tert-butyl-3-methyl phenol or 1,3,5-tri-tert-butyl phenol.

15. An electrochromic element according to claim 13, wherein the antioxidant contains approximately 0.1-2.0% by weight of the 1,3,5-trisubstituted phenol.