Coatings having low emissivity and low solar reflectance

• US 7,067,195 B2
• Filed: 04/25/2003
• Issued: 06/27/2006
• Est. Priority Date: 04/29/2002
• Status: Expired due to Term

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: Eby, Eric, Hoffman, Wayne L.
• Primary Examiner(s): McNeil, Jennifer C.
• Assistant Examiner(s): BLACKWELL, GWENDOLYN
• Application Number:
  US10/423,838
• Publication Number:
  US 20030228472A1
• Time in Patent Office: 1,159 Days
• Field of Search: 428/432, 428/433, 428/434, 428/699, 428/701, 428/702
• US Class Current: 428/432
• CPC Class Codes: C03C 17/002 for flat glass, e.g. float glass
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3615 Coatings of the type glass/metal/other inorganic layers, at least one layer being non-metallic
• 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 17/3631 one layer at least containing a selenide or telluride
• 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 17/3649 made of metals other than 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 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens
• CPC Class Codes: C03C 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

The invention provides low solar reflectance, low-emissivity coatings. The invention provides a monolithic pane bearing a low solar reflectance, low-emissivity coating. Further, the invention provides an insulating glass unit bearing a low solar reflectance, low-emissivity coating. Finally, the invention provides methods of producing coated substrates by depositing low solar reflectance, low-emissivity coatings.

Claims

1. A pane bearing a low-emissivity coating comprising, in sequence outwardly from the pane, an inner coat, a high absorption primary layer, a middle coat, an infrared-reflective layer, and an outer coat, the inner coat comprising at least one transparent dielectric film and being applied directly on the pane and having an optical thickness of less than about 272Å

, the middle coat comprising at least one transparent dielectric film and having an optical thickness of between about 600 Å and

about 872 Å

, said infrared-reflective layer comprising material that is highly reflective of infrared radiation and having a thickness of at least about 175 Å

, the high absorption primary layer comprising material that is highly absorptive of solar radiation and having a thickness of at least about 100 Å

, wherein a major portion of the thickness of the high absorption primary layer is metallic titanium.

2. The pane of claim 1 wherein said infrared-reflective layer comprises silver.

3. The pane of claim 1 wherein the low-emissivity coating includes a high absorption blocker layer directly over said infrared-reflective layer, the high absorption blocker layer having a thickness of between about 46 Å

and about 78 Å

.

4. The pane of claim 1 wherein the high absorption primary layer has a thickness of between about 110 Å

and about 144 Å

.

5. The pane of claim 1 wherein each film of the middle coat has a refractive index of between about 1.7 and about 2.4.

6. The pane of claim 1 further comprising a high absorption blocker layer deposited over said infrared-reflective layer, the high absorption blocker layer comprising material that is highly absorptive of solar radiation and having a thickness of at least about 45 Å

, wherein the high absorption blocker layer comprises titanium.

7. The pane of claim 6 wherein the high absorption blocker layer is deposited directly over said infrared-reflective layer.

8. The pane of claim 6 wherein a major portion of the thickness of the high absorption blocker layer is metallic titanium.

9. The pane of claim 6 wherein the high absorption blocker layer comprises an outer portion that is titanium oxide.

10. The pane of claim 6 wherein the thickness of the high absorption blocker layer is between about 54 Å

and about 68 Å

.

11. The pane of claim 1 wherein each film of the inner coat has a refractive index of between about 1.7 and about 2.4.

12. The pane of claim 1 wherein the outer coat comprises a layer of zinc oxide and a layer of silicon nitride over said layer of zinc oxide.

13. The pane of claim 12 wherein each film in the outer coat has a refractive index of between about 1.7 and about 2.4.

14. The pane of claim 1 wherein the pane is part of an insulating glass unit and the low-emissivity coating is carried on a #2 surface of the insulating glass unit.

15. The pane of claim 14 wherein the insulating glass unit has an exterior solar reflectance of less than about 30%.

16. The pane of claim 15 wherein the exterior solar reflectance is less than about 20%.

17. The pane of claim 16 wherein the exterior solar reflectance is about 16%.

18. The pane of claim 1 wherein the low-emissivity coating has an emissivity of less than about 0.07.

19. The pane of claim 18 wherein the emissivity is less than about 0.05.

20. The pane of claim 19 wherein the emissivity is about 0.044.

21. The pane of claim 14 wherein the insulating glass unit has an exterior visible reflectance of less than about 20%.

22. The pane of claim 21 wherein the exterior visible reflectance is less than about 15%.

23. The pane of claim 22 wherein the exterior visible reflectance is about 11%.

24. The pane of claim 14 wherein the insulating glass unit has a U Value of less than about 0.4.

25. The pane of claim 24 wherein the U Value is less than about 0.3.

26. The pane of claim 14 wherein the insulating glass unit has a solar heat gain coefficient of less than about 0.4.

27. The pane of claim 14 wherein the insulating glass unit has a transmitted color characterized by an a_h color coordinate of between about −

1.75 and about −

4.5 and a b_h color coordinate of between about −

2 and about −

5.

28. The pane of claim 14 wherein the insulating glass unit has an exterior reflected color characterized by an a_h color coordinate of between about 1.4 and about −

1.6 and a b_h color coordinate of between about 0.5 and about −

2.5.

31. The pane of claim 26 wherein the insulating glass unit has a solar heat gain coefficient of less than about 0.2.

32. The pane of claim 31 wherein the insulating glass unit has a solar heat gain coefficient of about 0.16.

33. The pane of claim 1 wherein the outer coat comprises at least one transparent dielectric film and has an optical thickness, the coating having a ratio defined as the optical thickness of the outer coat divided by the optical thickness of the middle coat, said ratio being between about 0.52 and about 0.88.

29. A pane bearing a low-emissivity coating comprising the following sequence of films:

a) an inner, applied directly to the pane, coat comprising at least one transparent dielectric film and having an optical thickness of less than about 272Å

;

b) a high absorption primary layer comprising material that is highly

absorptive of solar radiation and having a thickness of least about 100 Å

, wherein a major portion of the thickness of the high absorption primary layer is metallic titanium;

c) a middle coat comprising at least one transparent dielectric film and having an optical thickness of between about 600 Å and

about 872 Å

;

d) an infrared-reflective layer comprising material that is highly reflective of infrared radiation and having a thickness of at least about 175 Å

;

e) a high absorption blocker layer comprising material that is highly absorptive of solar radiation and having a thickness of at least about 45 Å

; and

f) an outer coat comprising a layer of zinc oxide and a layer of silicon nitride over said layer of zinc oxide.

34. The pane of claim 29 wherein the outer coat has an optical thickness, the coating has a ratio defined as the optical thickness of the outer coat divided by the optical thickness of the middle coat, and said ratio is between about 0.52 and about 0.88.

30. A pane bearing a low-emissivity coating comprising an infrared-reflective layer, a high absorption primary layer, an inner coat, and a middle coat, the inner coat comprising at least one transparent dielectric film and being deposited directly on the pane, wherein each film of the inner coat has a refractive index of between about 1.7 and about 2.4, said infrared-reflective layer comprising silver and having a thickness of at least about 175 Å

, the high absorption primary layer comprising material that is highly absorptive of solar radiation and having a thickness of at least about 100 Å

, wherein a major portion of the thickness of the high absorption primary layer is metallic titanium, the middle coat comprising at least one transparent dielectric film and being positioned between said infrared-reflective layer and the high absorption primary layer, wherein the low-emissivity coating includes a high absorption blocker layer directly over said infrared-reflective layer, the high absorption blocker layer having a thickness of at least about 45 Å

, wherein the pane is part of an insulating glass unit and the low-emissivity coating is carried on a #2 surface of the insulating glass unit, the insulating glass unit having an exterior solar reflectance of less than about 20% and having a transmitted color characterized by an a_h color coordinate and a b_h color coordinate, both of said color coordinates being negative such that the insulating glass unit has a transmitted hue within a range that is entirely within a blue-green range.

35. The pane of claim 30 wherein the insulating glass unit has a solar heat gain coefficient of less than about 0.2.