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

• US 7,339,728 B2
• Filed: 02/23/2006
• Issued: 03/04/2008
• 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): Allen; Stephone B.
• Assistant Examiner(s): Chapel; Derek S.
• Application Number:
  US11/360,266
• Publication Number:
  US 20070081227A1
• Time in Patent Office: 740 Days
• Field of Search: None
• US Class Current: 359/360
• 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

Low-emissivity coatings that are highly reflective to infrared radiation. The coating includes three infrared-reflection film regions, which may each include 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 the first pane 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 first, second, and third infrared-reflection film regions each comprising silver, the first infrared-reflection film region being closest to the first pane of the three infrared-reflection film regions, the second infrared-reflection film region being further from the first pane than the first infrared-reflection film region, the third infrared-reflection film region being further from the first pane than the second infrared-reflection film region, and wherein the second infrared-reflection film region is thicker than the first infrared-reflection film region by at least 30 angstroms, wherein the three infrared-reflection film regions have a combined thickness of greater than 460 angstroms and yet the insulating glazing unit has a visible transmittance of 0.65 or more.

2. The pane of claim 1 wherein the combined thickness of the three infrared-reflection film regions is greater than 470 angstroms.

3. The pane of claim 2 wherein the combined thickness of the three infrared-reflection film regions is greater than 485 angstroms.

4. The pane of claim 1 wherein said visible transmittance is 0.66 or more.

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

6. The pane of claim 5 wherein the outermost two infrared-reflection film regions have a combined thickness of at least 340 angstroms.

7. The pane of claim 6 wherein the outermost two infrared-reflection film regions have a combined thickness of at least 355 angstroms.

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

/square.

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

/square.

10. The pane of claim 1 wherein the insulating glazing unit has a visible-thermal efficiency ratio of greater than 2.37.

11. The pane of claim 10 wherein the visible-thermal efficiency ratio is greater than 2.42.

12. The pane of claim 10 where the visible-thermal efficiency ratio is about 2.4-2.5.

13. 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.

14. 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 outward:

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, wherein the second infrared-reflection film region is thicker than the first infrared-reflection film region by at least 30 angstroms, wherein between the first infrared-reflection film region and said major surface of the substrate there is a desired total thickness of transparent dielectric film having a refractive index of 1.7 or greater, said desired total thickness being less than 195 angstroms, and wherein the second and third infrared-reflection film regions have a combined thickness of at least 325 angstroms and yet the coated substrate has a monolithic visible transmittance of greater than 0.65, wherein the three infrared-reflection film regions have a combined thickness of greater than 460 angstroms.

15. The substrate of claim 14 wherein the combined thickness of the second and third infrared-reflection film regions is at least 340 angstroms.

16. The pane of claim 15 wherein the combined thickness of the second and third infrared-reflection film regions is at least 355 angstroms.

17. The substrate of claim 14 wherein the combined thickness of the three infrared-reflection film regions is greater than 470 angstroms.

18. The substrate of claim 17 where the combined thickness of the three infrared-reflection film regions is greater than 485 angstroms.

19. The substrate of claim 14 wherein said coated major surface has a sheet resistance of less than 1.4 Ω

/square.

20. The substrate of claim 14 wherein said coated major surface has a sheet resistance of about 1.25-1.3 Ω

/square.

21. The substrate of claim 14 wherein said desired total thickness is less than 175 angstroms.