Electrochemichromic solutions, processes for preparing and using the same, and devices manufacturing with the same

• US 5,611,966 A
• Filed: 06/01/1995
• Issued: 03/18/1997
• Est. Priority Date: 09/06/1991
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Looman, Steven D., Varaprasad, Desaraju V., Zhao, Mingtang, Lynam, Niall R., Habibi, Hamid R.
• Primary Examiner(s): TUCKER, PHILIP C
• Application Number:
  US08/458,080
• Time in Patent Office: 656 Days
• Field of Search: 252/583, 252/586, 359/270, 359/272
• US Class Current: 252/583
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• 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

The present invention relates to electrochromic solutions and devices manufactured therefrom. More precisely, the invention relates to electrochemichromic solutions, and those devices manufactured with the same, that demonstrate superior responsiveness to those solutions known heretofore when an applied potential is introduced thereto. That is, the responsiveness observed in terms of solution coloring is of a greater rapidity, intensity and uniformity than those electrochemichromic solutions of the prior art. Preparation of these solutions involve the novel process of pre-treating at least one of the electrochemichromic compounds with a redox agent prior to placing it in contact with the other electrochemichromic compound. Moreover, the present invention relates to methods of preparing such novel solutions and processes for using these solutions to provide devices that exhibit and benefit from the aforementioned superior characteristics.

Claims

1. An electrochemichromic device comprising:

(a) a first substantially transparent substrate coated with a substantially transparent conductive coating on its interior face having a sheet resistance in the range of from about 1 to about 100 ohms per square;

(b) a second substantially transparent substrate coated with a substantially transparent conductive coating on its interior face having a sheet resistance in the range of from about 1 to about 100 ohms per square, said second substrate positioned in substantially parallel spaced-apart relationship with said first substrate and being laterally displaced therefrom;

(c) a sealing means positioned toward the peripheral edge of each of said first substrate and said second substrate and sealing forming a cell cavity therebetween;

(d) an electrochemichromic solution capable of color change when an applied potential is introduced thereto having been dispensed into and confined within said cell cavity, said electrochemichromic solution comprising;

(i) at least one anodic compound, the anodic compound having been previously contacted with a redox agent such that the anodic compound exists in a different valence state than prior to having been contacted with the redox agent;

(ii) at least one cathodic compound; and

(iii) a solvent,

wherein the redox potential of the anodic compound in the different valence state is greater than the redox potential of the cathodic compound while each is contacted with the solvent; and

(e) a means for introducing an applied potential to said electrochemichromic solution to controllably cause a variation in the amount of light transmitted through said device.

2. The electrochemichromic device according to claim 1, wherein the anodic compound of said electrochemichromic solution may be selected from the group consisting of the following chemical formulae:

##STR4## and combinations thereof.

3. The electrochemichromic device according to claim 2, wherein the anodic compound is ##STR5##

4. An electrochemichromic mirror having a range of reflectance from greater than about 70% to less than about 10%, said electrochemichromic mirror comprising:

(a) a first substantially transparent substrate coated with a substantially transparent conductive coating on its interior face having a sheet resistance in the range of from about 1 to about 100 ohms per square;

(b) a second substantially transparent substrate coated with a substantially transparent conductive coating on its interior face having a sheet resistance in the range of from about 1 to about 100 ohms per square, said second substrate positioned in substantially parallel spaced-apart relationship with said first substrate and being laterally displaced therefrom;

(c) a reflective coating on a face of either one of said first substrate or said second substrate;

(d) a sealing means positioned toward the peripheral edge of each of said first substrate and said second substrate and sealingly forming a cell cavity therebetween;

(e) an electrochemichromic solution capable of color change when an applied potential is introduced thereto having been dispensed into and confined within said cell cavity, said electrochemichromic solution comprising;

(i) at least one anodic compound, the anodic compound having been previously contacted with a redox agent such that the anodic compound exists in a different valence state than prior to having been contacted with the redox agent;

(ii) at least one cathodic compound; and

(iii) a solvent,

wherein the redox potential of the anodic compound in the different valence state is greater than the redox potential of the cathodic compound while each is contacted with the solvent; and

(f) a means for introducing an applied potential to said electrochemichromic solution to controllably cause a variation in the amount of light reflected from said mirror.

5. The electrochemichromic mirror according to claim 4, wherein the anodic compound of said electrochemichromic solution may be selected from the group consisting of the following chemical formulae:

##STR6## and combinations thereof.

6. The electrochemichromic mirror according to claim 5, wherein the anodic compound is ##STR7##

7. An electrochemichromic rearview mirror for a motor vehicle comprising:

(a) first and second spaced substrates, each having an interior face and an exterior face, said first and second spaced substrates disposed so as to define a space between the interior face of the first substrate and the interior face of the second substrate;

(b) an electrochemichromic solution, disposed in said defined space, capable of color change when an applied potential is introduced thereto, said electrochemichromic solution comprising;

(i) at least one anodic compound, the anodic compound having been previously contacted with a redox agent such that the anodic compound exists in a different valence state than prior to having been contacted with the redox agent;

(ii) at least one cathodic compound; and

(iii) a solvent,

wherein the redox potential of the anodic compound in the different valence state is greater than the redox potential of the cathodic compound while each is contacted with the solvent; and

(c) means for introducing an applied potential to said electrochemichromic solution, comprising a substantially transparent conductive coating disposed on at least one of the interior face of the first substrate and the interior face of the second substrate.

8. The electrochromic rearview mirror according to claim 7, wherein said means for introducing an applied potential comprises a substantially transparent conductive coating disposed on the interior face of the first substrate and a metal reflector disposed on the interior face of the second substrate.

9. The electrochemichromic rearview mirror according to claim 7, wherein said means for introducing an applied potential comprises a substantially transparent conductive coating disposed on each of the interior face of the first substrate and the interior face of the second substrate.

10. The electrochemichromic rearview mirror according to claim 7, wherein the anodic compound of said electrochemichromic solution may be selected from the group consisting of the following chemical formulae:

##STR8## and combinations thereof.

11. The electrochemichromic rearview mirror according to claim 7, wherein the anodic compound is ##STR9##