High infrared reflection coatings

• US 7,572,511 B2
• Filed: 10/10/2006
• Issued: 08/11/2009
• 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
• Primary Examiner(s): Speer; Timothy M
• Assistant Examiner(s): ROBINSON, LAUREN E
• Application Number:
  US11/545,323
• Publication Number:
  US 20070082169A1
• Time in Patent Office: 1,036 Days
• Field of Search: 428/428, 428/432, 428/434
• US Class Current: 428/432
• 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: 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 coated transparent pane having opposed first and second major surfaces, said coated pane being part of a multiple-pane insulating glazing unit that includes a second pane, wherein the insulating glazing unit has a between-pane space to which the second major surface of said coated pane is exposed, said second major surface bearing a low-emissivity coating that includes the following film regions in sequence moving away from said second major surface:

a first transparent dielectric film region, a first infrared-reflection film region, a second transparent dielectric film region, a second infrared-reflection film region, a third transparent dielectric film region, a third infrared-reflection film region, and a fourth transparent dielectric film region, the coating having both a sheet resistance of less than 2.5 Ω

/square and an emissivity of less than 0.03, said three infrared-reflection film regions having a combined thickness of greater than 425 angstroms, the coating having a primary dielectric-region ratio that is greater than 0.34 and less than 0.75, the primary dielectric-region ratio being defined as the thickness of the first transparent dielectric film region divided by the thickness of the fourth transparent dielectric film region.

2. The coated pane of claim 1 wherein the primary dielectric-region ratio is greater than 0.34 and less than 0.6.

3. The coated pane of claim 1 wherein the emissivity is less than 0.025.

4. The coated pane of claim 1 wherein the sheet resistance is less than 2.0 Ω

/square.

5. The coated pane of claim 1 wherein the combined thickness of the first, second, and third infrared-reflection film regions is greater than 450 angstroms.

6. The coated pane of claim 1 wherein the low-emissivity coating includes transparent dielectric film between said second major surface and the first infrared-reflection film region, and wherein between the first infrared-reflection film region and said second major surface the coating has less than 190 angstroms of transparent dielectric film having a refractive index of 1.7 or greater.

7. The coated pane of claim 6 wherein between the first infrared-reflection film region and said second major surface the coating has less than 175 angstroms of transparent dielectric film having a refractive index of 1.7 or greater.

8. The coated pane of claim 1 wherein the low-emissivity coating has a total thickness of greater than 1,800 angstroms.

9. The coated pane of claim 1 wherein the low-emissivity coating has a total thickness of greater than 1,900 angstroms.

10. The coated pane of claim 1 wherein the low-emissivity coating includes at least one nitride or oxynitride film having a thickness of less than 150 angstroms, and wherein the coating further includes at least one nitride or oxynitride film having a thickness of greater than 50 angstroms.

11. The coated pane of claim 10 wherein said nitride or oxynitride film having a thickness of greater than 50 angstroms is a spacer layer positioned between two of said infrared-reflection film regions.

12. The coated pane of claim 1 wherein the coated pane has a major dimension of at least one meter.

13. The coated pane of claim 1 wherein the emissivity is less than 0.023.

14. The coated pane of claim 1 wherein both panes of said glazing unit are clear glass.

15. The coated pane of claim 1 wherein at least one of the infrared-reflection film regions has a thickness of greater than 175 angstroms.

16. The coated pane of claim 1 wherein at least one of the infrared-reflection film regions has a thickness of greater than 200 angstroms.

17. The coated pane of claim 7 wherein between the first infrared-reflection film region and said second major surface the coating has less than 140 angstroms of transparent dielectric film having a refractive index of 1.7 or greater.

18. The coated pane of claim 1 wherein said second major surface is a #2 surface of said glazing unit.

19. The coated pane of claim 1 wherein the low-emissivity coating has a total thickness of greater than 2,000 angstroms.

20. The coated pane of claim 1 wherein the coated pane has a transmittance at 740 nm of less than 0.05.