Method for reducing haze in tin oxide transparent conductive coatings

• US 5,900,275 A
• Filed: 07/15/1992
• Issued: 05/04/1999
• Est. Priority Date: 07/15/1992
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Agrawal, Anoop, Cronin, John P., Trosky, Michael
• Primary Examiner(s): BELL, JANYCE A
• Application Number:
  US07/914,852
• Time in Patent Office: 2,484 Days
• Field of Search: 427/126.2, 427/126.3, 427/108, 427/226, 427/419.3, 427/240, 427/421, 427/430.1, 427/165, 427/168, 427/169, 427/162, 427/110
• US Class Current: 427/108
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence

Abstract

The haze in a conductive tin oxide coating deposited on a substrate, particularly glass, can be reduced by applying, to a desired thickness, a solid-state coating, where the solid-state layer is applied as a precursor liquid to the tin oxide layer, is then dried and/or converted to a solid-state film overlying the conductive tin oxide film on the substrate.

Claims

1. A method for reducing the haze in a conductive tin oxide film on a substrate comprising:

providing a substrate having a conductive tin oxide surface film;

providing a solution of a metallic oxide precursor in a suitable carrier solvent;

coating said conductive tin oxide surface with said solution by a wet chemical solution deposition process to form a coating of a desired thickness; and

removing said solvent and converting said precursor to a solid-state metal oxide film overlying said tin oxide surface;

said tin oxide surface having a sheet resistance of less than or equal to 20 ohms/square;

said metallic oxide precursor being a metal-peroxy acid ester.

2. A method in accordance with claim 1 wherein said coating solution is applied to said substrate by a wet chemical solution deposition process selected from the group consisting of dip coating, spin coating, spray deposition and casting.

3. A method in accordance with claim 2 wherein said converting step comprises heating said coated substrate to a conversion temperature of from about 250°

C. to about 350°

C.

4. A method in accordance with claim 3 wherein said converting step comprises holding said coated substrate at said conversion temperature for about 15 to about 120 minutes.

5. A method in accordance with claim 4 wherein said tin oxide surface has an initial haze level of less than about 30%.

6. A method in accordance with claim 5 wherein said tin oxide surface has an initial haze level of less than about 10%.

7. A method for reducing the haze in a conductive tin oxide film on a substrate comprising:

providing a substrate having a conductive tin oxide surface film;

providing a solution of a metallic oxide precursor in a suitable carrier solvent;

coating said conductive tin oxide surface with said solution by a wet chemical solution deposition process to form a coating of a desired thickness;

removing said solvent and converting said precursor to a solid-state metal oxide film overlying said tin oxide surface;

said metallic oxide precursor being selected to form an electrochromically-active metallic oxide whereby said solid-state metallic oxide film overlying said tin oxide surface is an electrochromically-active metallic oxide film;

said metallic oxide precursor being a metal-peroxy acid ester.

8. A method for reducing the haze in a conductive tin oxide film on a substrate comprising:

providing a substrate having a conductive tin oxide surface film;

providing a solution of a metallic oxide precursor in a suitable carrier solvent;

coating said conductive tin oxide surface with said solution by a wet chemical solution deposition process to form a coating of a desired thickness;

removing said solvent and converting said precursor to a solid-state metal oxide film overlying said tin oxide surface;

said metallic oxide precursor being selected to form an electrochromically-active metallic oxide whereby said solid-state metallic oxide film overlying said tin oxide surface is an electrochromically-active metallic oxide film;

said tin oxide surface having a sheet resistance of less than or equal to 20 ohms/square;

said metallic oxide precursor being a metal-peroxy acid ester.

9. A method for reducing the haze in a conductive tin oxide film on a substrate comprising:

providing a substrate having a conductive tin oxide surface film;

providing a solution of a metallic oxide precursor in a suitable carrier solvent;

coating said conductive tin oxide surface with said solution by a wet chemical solution deposition process to form a coating of a desired thickness;

removing said solvent and converting said precursor to a solid-state metal oxide film overlying said tin oxide surface;

selecting a metallic oxide precursor which will yield an electrically conductive metallic oxide such that said solid-state metal oxide film overlaying said tin oxide surface will be conductive;

said metallic oxide precursor being selected so as to yield, upon conversion, a tin oxide layer, a doped tin oxide layer, an indium oxide layer or an indium tin oxide layer.

10. A method for reducing the haze in a substrate having a conductive tin oxide surface formed by:

providing a substrate having a conductive tin oxide surface;

providing a solid-state precursor in a liquid form;

coating said conductive tin oxide surface with said liquid by a wet chemical coating means; and

converting said liquid to a solid-state film overlying said tin oxide surface to reduce the haze present in said tin oxide surface;

said coating solution being applied to said substrate by a wet chemical coating means selected from the group consisting of dip coating, spin coating, spray deposition and casting;

said precursor comprising a carbon polymer precursor.

11. A method in accordance with claim 10 wherein said tin oxide surface has an initial haze level of less than about 30%.

12. A method in accordance with claim 11 wherein said tin oxide surface has an initial haze level of less than about 10%.

13. A method in accordance with claim 10 wherein said precursor is an acrylated epoxy urethane polymer.