Electrochromic devices with polymeric electrolytes

• US 4,174,152 A
• Filed: 02/13/1978
• Issued: 11/13/1979
• Est. Priority Date: 02/13/1978
• Status: Expired due to Term

• Current Assignee: American Colloid Company (Minerals Technologies Incorporated)
• Original Assignee: American Colloid Company (Minerals Technologies Incorporated)
• Inventors: Sedlak, John A., Giglia, Robert D., Lipp, David W.
• Primary Examiner(s): Hunt, Brooks H.
• Assistant Examiner(s): Gron, T. S.
• Application Number:
  US05/877,139
• Time in Patent Office: 638 Days
• Field of Search: 350/357, 252/500, 252/408
• US Class Current: 359/270
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte

Abstract

Improved electrochromic devices result from the incorporation of novel polymeric electrolytes. The electrolytes are based upon copolymers prepared from vinyl monomers and acid-group-containing monomers.

Claims

1. An electrochromic device comprising an electrode in contact with a layer of persistent electrochromic material which in turn is in contact with an ion conductive hydrophilic, clear vinyl polymer electrolyte which in turn is in contact with a counterelectrode, and electrical means for selectively applying electrical fields of opposite polarity across said electrodes, wherein the electrolyte comprises a copolymer or partially cross-linked copolymer of 95 to 20% by weight of a vinyl monomer selected from 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, and 2-hydroxypropyl acrylate and 5 to 80% by weight of an acid-group-containing monoethylenically unsaturated monomer.

2. The device of claim 1 wherein the acid-group containing monomer is selected from 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid, methacrylic acid, 2-sulfoethylmethacrylate, alpha-chloroacrylic acid, and 4-vinylsalicyclic acid.

3. The device of claim 1 wherein the copolymer is a copolymer of 2-hydroxyethyl methacrylate and 2-acrylamido-2-methylpropanesulfonic acid.

4. The device of claim 1 wherein the copolymer is at least partially crosslinked.

5. The device of claim 1 wherein the copolymer further contains a humectant.

6. The device of claim 5 wherein the humectant is selected from glycerol, tetraethylene glycol and hydroxy terminated polyethylene oxide.

7. The device of claim 1 wherein the electrochromic material is WO₃.