Low-emissivity coatings having high visible transmission and low solar heat gain coefficient

• US 20070081227A1
• Filed: 02/23/2006
• Published: 04/12/2007
• Est. Priority Date: 10/11/2005
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: Hartig, Klaus
• Granted Patent: US 7,339,728 B2
• Time in Patent Office: Days
• US Class Current: 359/359
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3618 Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3644 the metal being silver
• 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 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/185 by cathodic sputtering
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence
• CPC Class Codes: Y10T 428/231 Filled with gas other than air; or under vacuum

Abstract

The invention provides low-emissivity coatings that are highly reflective of infrared radiation. The coating includes three infrared-reflection film regions, which may each comprise silver.

Claims

1. A first pane having opposed first and second major surfaces, the first pane being part of a multiple-pane insulating glazing unit that includes a second pane, wherein the insulating glazing unit has at least one between-pane space, wherein at least one of the first and second panes has a coated interior surface that is exposed to a between-pane space of the insulating glazing unit, said coated interior surface bearing a low-emissivity coating that includes three infrared-reflection film regions each comprising silver, the insulating glazing unit having a visible-thermal efficiency ratio of greater than 2.37.

2. The pane of claim 1 where the visible-thermal efficiency ratio is greater than 2.42.

3. The pane of claim 1 where the visible-thermal efficiency ratio is about 2.4-2.5.

4. The pane of claim 1 where the insulating glazing unit has a visible transmittance of 0.65 or more.

5. The pane of claim 4 where said visible transmittance is 0.66 or more.

6. The pane of claim 1 where the three infrared-reflection film regions have a combined thickness of greater than 460 angstroms.

7. The pane of claim 6 where the combined thickness of the three infrared-reflection film regions is greater than 470 angstroms.

8. The pane of claim 7 where the combined thickness of the three infrared-reflection film regions is greater than 485 angstroms.

9. The pane of claim 1 where an outermost two of the infrared-reflection film regions have a combined thickness of at least 325 angstroms.

10. The pane of claim 9 wherein the outermost two infrared-reflection film regions have a combined thickness of at least 340 angstroms.

11. The pane of claim 10 wherein the outermost two infrared-reflection film regions have a combined thickness of at least 355 angstroms.

12. The pane of claim 1 wherein said coated interior surface has a sheet resistance of less than 1.4 Ω

/square.

13. The pane of claim 1 wherein said coated interior surface has a sheet resistance of about 1.25-1.3 Ω

/square

14. The pane of claim 1 wherein beneath an innermost of the infrared-reflection film regions there is provided a total thickness of less than 195 angstroms of transparent dielectric film having a refractive index of 1.7 or greater.

15. A first pane having opposed first and second major surfaces, the first pane being part of a multiple-pane insulating glazing unit that includes a second pane, wherein the insulating glazing unit has at least one between-pane space, wherein at least one of the first and second panes has a coated interior surface that is exposed to a between-pane space of the insulating glazing unit, said coated interior surface bearing a low-emissivity coating that includes three infrared-reflection film regions each comprising silver, the three infrared-reflection film regions having a combined thickness of greater than 460 angstroms, the insulating glazing unit having a visible transmittance of 0.65 or more.

16. The pane of claim 15 wherein the combined thickness of the three infrared-reflection film regions is greater than 470 angstroms.

17. The pane of claim 16 wherein the combined thickness of the three infrared-reflection film regions is greater than 485 angstroms.

18. The pane of claim 15 wherein said visible transmittance is 0.66 or more.

19. The pane of claim 15 wherein an outermost two of the infrared-reflection film regions have a combined thickness of at least 325 angstroms.

20. The pane of claim 19 wherein the outermost two infrared-reflection film regions have a combined thickness of at least 340 angstroms.

21. The pane of claim 20 wherein the outermost two infrared-reflection film regions have a combined thickness of at least 355 angstroms.

22. The pane of claim 15 wherein said coated interior surface has a sheet resistance of less than 1.4 Ω

/square.

23. The pane of claim 15 wherein said coated interior surface has a sheet resistance of about 1.25-1.3 Ω

/square.

24. The pane of claim 15 wherein the insulating glazing unit has a visible-thermal efficiency ratio of greater than 2.37.

25. The pane of claim 24 wherein the visible-thermal efficiency ratio is greater than 2.42.

26. The pane of claim 24 where the visible-thermal efficiency ratio is about 2.4-2.5.

27. The pane of claim 15 wherein beneath an innermost of the infrared-reflection film regions there is provided a total thickness of less than 195 angstroms of transparent dielectric film having a refractive index of 1.7 or greater.

28. A transparent substrate having a major surface bearing a low-emissivity coating, the coating comprising a first infrared-reflection film region having a thickness, a second infrared-reflection film region having a thickness, and a third infrared-reflection film region having a thickness, where the thickness of the third infrared-reflection film region is greater than the thickness of the second infrared-reflection film region, and the thickness of the second infrared-reflection film region is greater than the thickness of the first infrared-reflection film region, the coating comprising, from said major surface outwardly:

a) a first transparent dielectric film region;

b) the first infrared-reflection film region;

c) a second transparent dielectric film region;

d) the second infrared-reflection film region;

e) a third transparent dielectric film region;

f) the third infrared-reflection film region;

g) a fourth transparent dielectric film region;

wherein the first, second, and third infrared-reflection film regions each comprise silver, the second and third infrared-reflection film regions having a combined thickness of at least 325 angstroms.

29. The substrate of claim 28 wherein the combined thickness of the second and third infrared-reflection film regions is at least 340 angstroms.

30. The pane of claim 29 wherein the combined thickness of the second and third infrared-reflection film regions is at least 355 angstroms.

31. The substrate of claim 28 wherein the three infrared-reflection film regions have a combined thickness of greater than 460 angstroms.

32. The substrate of claim 31 wherein the combined thickness of the three infrared-reflection film regions is greater than 470 angstroms.

33. The substrate of claim 32 where the combined thickness of the three infrared-reflection film regions is greater than 485 angstroms.

34. The substrate of claim 28 wherein said coated major surface has a sheet resistance of less than 1.4 Ω

/square.

35. The substrate of claim 28 wherein said coated major surface has a sheet resistance of about 1.25-1.3 Ω

/square.

36. The substrate of claim 28 wherein the first transparent dielectric film region comprises film having a refractive index of 1.7 or greater, and wherein between the first infrared-reflection film region and said major surface of the substrate there is a desired total thickness of film that has a refractive index of 1.7 or greater, said desired total thickness being less than 195 angstroms.

37. The substrate of claim 36 wherein said desired total thickness is less than 175 angstroms.