Devices containing compositions comprising cathodically coloring electrochromic polymers and binder polymers

• US 8,023,171 B2
• Filed: 03/30/2010
• Issued: 09/20/2011
• Est. Priority Date: 04/03/2009
• Status: Expired due to Fees

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Yale, David, Jankauskas, Jennifer, Cliff, Nancy Nase, Unur, Ece
• Primary Examiner(s): Pinkney; Dawayne A
• Application Number:
  US12/749,584
• Publication Number:
  US 20100253994A1
• Time in Patent Office: 539 Days
• Field of Search: 359/288, 359265-277, 359/245, 359/247, 359/254, 359/242, 359/240, 359250-253, 359/315, 359/318, 359/321, 345/49, 345/105, 348/817, 250/70, 438/929
• US Class Current: 359/273
• 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 1/15165 Polymers
• CPC Class Codes: G02F 2001/15145 the electrochromic layer comprises a mixture of anodic and cathodic compounds

Abstract

Electrically active, cathodically coloring electrochromic polymers are blended with a non-electrochromic, non-electrically conductive binder polymer to provide an electrochomic composition with greatly enhanced performance in an electrochromic device over time. It is also found that blending an electrochromic polymer with a non-coloring electroactive material allows for greater design in preparing electrochromic devices as it enables the use of a higher amount of typically low coloring anodic materials due to increased need for charge balancing.

Claims

1. An electrochromic device comprising a cathodically coloring electrochromic composition with excellent color characteristics and durability, which composition comprises an electrically active, cathodically coloring polymer and a non-electrically conductive binder polymer in a weight ratio of cathodically coloring polymer to binder polymer of from about 1:

99 to about 99;

1, wherein the binder polymer is selected from crosslinked or non-crosslinked acrylate, acrylamide, polyester, polyimide, polyurethane, polyolefin, polyvinyl alcohol, epoxy and fluoro polymers and

wherein the cathodically coloring polymer is of formula II

2. An electrochromic device according to claim 1, where in the cathodically coloring polymer R¹⁰, R¹¹, R¹² and R¹³ are —

R′

OR″

groups where R′

is methylene, ethylene or propylene and R″

is a linear or branched C₂ to C₃₀ alkyl.

3. An electrochromic device according to claim 1, where X is unsubstituted benzathiadiazole.

4. An electrochromic device according to claim 1, where in the cathodically coloring polymer R¹⁰, R¹¹, R¹² and R¹³ are —

R′

OR″

groups where R′

is methylene, ethylene or propylene and R″

is a linear or branched C₂ to C₃₀ alkyl and X is unsubstituted benzathiadiazol.

5. An electrochromic device according to claim 1, wherein the binder polymer is selected from crosslinked or non-crosslinked acrylate, acrylamide, polyester and polyvinyl alcohol polymers.

6. An electrochromic device according to claim 1 wherein the binder polymer is obtained and blended with the cathodically coloring polymer as an aqueous solution, latex or dispersion.

7. An electrochromic device according to claim 1 wherein the non-electrically conductive binder polymer is also non-ionically conductive.

8. An electrochromic device according to claim 1, which also comprises an anodically coloring component.

9. An electrochromic device according to claim 8, wherein the anodically coloring component comprises an electroactive, anodically coloring polymer.

10. An electrochromic device according to claim 9, wherein the anodically coloring component comprises an alkoxy or dialkoxy substituted pyrrole polymer.

11. An electrochromic device according to claim 1, wherein the cathodically coloring composition also comprises a non-coloring electroactive polymer.

12. A method for preserving breadth of color space and/or intensity of color strength of an cathodically coloring electrochromic composition comprising an cathodically coloring polymer, which method comprises blending the cathodically coloring polymer with a non-electrically conducting binder polymer prior to incorporation as a single layer into an electrocromic device, wherein the binder polymer is selected from crosslinked or non-crosslinked acrylate, acrylamide, polyether, polyester, polyamide, polyurethane, polyolefin, polyvinyl alcohol, epoxy and fluoro polymers and

wherein the cathodically coloring polymer is of formula II

13. A method according to claim 12, where in the cathodically coloring polymer R¹⁰, R¹¹, R¹² and R¹³ are —

R′

OR″

groups where R′

is methylene, ethylene or propylene and R″

is a linear or branched C₂ to C₃₀ alkyl and X is unsubstituted benzathiadiazole.

14. A method according to claim 12, wherein the binder polymer is selected from crosslinked or non-crosslinked acrylate, acrylamide, polyester and polyvinyl alcohol polymers.

15. A method according to claim 12 wherein the binder polymer is obtained and blended with the cathodically coloring polymer as an aqueous solution, latex or dispersion.