Haze-resistant low-emissivity coatings

• US 20070237980A1
• Filed: 03/30/2006
• Published: 10/11/2007
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: Hartig, Klaus, Krisko, Annette
• Granted Patent: US 7,632,571 B2
• Time in Patent Office: Days
• US Class Current: 428/623
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3652 the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C03C 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens
• CPC Class Codes: C03C 17/3686 the multilayer coating being used for ovens
• CPC Class Codes: C03C 17/3694 one layer having a composition gradient through its thickness
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: Y10T 428/12549 Adjacent to each other

Abstract

A substrate bearing a low-emissivity coating, the coating comprising two infrared-reflective layers separated by a middle coat, the middle coat comprising two zinc tin oxide film regions separated by a tin oxide film region.

Claims

1. A sheet-like substrate having first and second general-opposed major surfaces, at least one of the major surfaces bearing a low-emissivity coating, the coating comprising, in sequence, from the substrate outwardly:

a) an inner dielectric layer;

b) a first infrared-reflective layer;

c) a middle coat comprising a first zinc tin oxide film region, a tin oxide film region, and a second zinc tin oxide film region, wherein said tin oxide film region is positioned between said first and second zinc tin oxide film regions;

d) a second infrared-reflective layer; and

e) an outer dielectric layer.

2. The substrate of claim 1 wherein the tin oxide film region has a thickness of less than 100 angstroms.

3. The substrate of claim 1 wherein the tin oxide film region has a thickness of between about 5 angstroms and about 80 angstroms.

4. The substrate of claim 1 wherein the tin oxide film region has a thickness of between about 30 angstroms and about 70 angstroms.

5. The substrate of claim 1 wherein the first and second zinc tin oxide film regions have a combined thickness of at least about 300 angstroms.

6. The substrate of claim 1 wherein the first and second zinc tin oxide film regions are each sputter deposited from one or more targets each comprising sputterable material containing between about 11% and about 16% tin by weight with the remainder being zinc.

7. The substrate of claim 1 wherein the second infrared-reflective layer is positioned directly over the second zinc tin oxide film region.

8. The substrate of claim 1 comprising a blocker layer disposed between the first infrared-reflective layer and the middle coat.

9. The substrate of claim 1 wherein all the film regions of the middle coat comprise at least some tin oxide.

10. A sheet-like substrate having first and second generally-opposed major surfaces, at least one of the major surfaces bearing a low-emissivity coating, the coating comprising two infrared-reflective silver-containing layers separated by a middle coat, the middle coat comprising two zinc tin oxide film regions separated by a tin oxide film region, the tin oxide film region having a thickness of less than 100 angstroms.

11. The substrate of claim 10 wherein the tin oxide film region has a thickness of between about 30 angstroms and about 70 angstroms.

12. The substrate of claim 10 wherein low-emissivity coating comprises first, second and third infrared-reflective layers and the middle coat deposited between both the first and second infrared-reflective layers and the second and third infrared-reflective layers.

13. A method of producing a coated glass article, the method comprising:

a) providing a glass sheet;

b) forming a coating on a major surface of the glass sheet by depositing the following film regions in sequence from said major surface outwardly;

i) an inner dielectric layer;

ii) a first infrared-reflective layer;

iii) a middle coat comprising a first zinc tin oxide film region, a tin oxide film region, and a second zinc tin oxide film region;

iv) a second infrared-reflective layer; and

v) an outer dielectric layer.

14. The method of claim 13 wherein the tin oxide film region is deposited at a thickness of less than 100 angstroms.

15. The method of claim 13 wherein the tin oxide film region is deposited at a thickness of between about 5 angstroms and about 80 angstroms.

16. The method of claim 13 wherein the tin oxide film region is deposited at a thickness of between about 30 angstroms and about 70 angstroms.

17. The method of claim 13 wherein the first and second zinc tin oxide film regions are deposited at a combined thickness of at least about 300 angstroms.

18. The method of claim 13 wherein the first and second zinc tin oxide film regions are each sputter deposited from one or more targets each comprising sputterable target material containing between about 11% and about 16% tin by weight with the remainder being zinc.

19. The method of claim 13 wherein the second infrared-reflective film region is deposited directly over the second zinc tin oxide film region.

20. The method of claim 13 further comprising a blocker layer deposited between the first infrared-reflective film region and the middle coat.

21. The method of claim 13 wherein all the film regions of the middle coat comprise at least some tin oxide.