Low-emissivity coating having low solar reflectance

• US 20040028955A1
• Filed: 04/25/2003
• Published: 02/12/2004
• Est. Priority Date: 04/29/2002
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: Hoffman, Wayne L.
• Granted Patent: US 7,063,893 B2
• Time in Patent Office: Days
• US Class Current: 428/702
• 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 also provides a pane bearing a low solar reflectance, low-emissivity coating. Further, the invention provides an insulating glass unit comprising first and second panes held in a spaced-apart configuration, wherein the panes have confronting inner surfaces oriented toward a between-pane space and opposed outer surfaces oriented away from the between-pane space, and wherein one of these inner surfaces bears a low solar reflectance, low-emissivity coating. Also provided are methods of producing coated substrates.

Claims

1. A pane bearing a low-emissivity coating comprising an infrared-reflective layer, a high absorption primary layer, and a middle coat, wherein said infrared-reflective layer comprises material that is highly reflective of infrared radiation, the high absorption primary layer comprises material that is highly absorptive of solar radiation and includes at least about 100 angstroms of film, and the middle coat comprises at least one transparent dielectric film, the middle coat being positioned between the high absorption primary layer and said infrared-reflective layer.

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

3. The pane of claim 1 wherein the high absorption primary layer comprises titanium.

4. The pane of claim 3 wherein a major portion of the thickness of the high absorption primary layer is metallic titanium.

5. The pane of claim 1 wherein said infrared-reflective layer is positioned further from the pane than the high absorption primary layer.

6. The pane of claim 5 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 including at least about 75 angstroms of film.

7. The pane of claim 6 wherein the high absorption blocker layer is contiguous to said infrared-reflective layer.

8. The pane of claim 7 wherein the high absorption blocker layer comprises titanium.

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

10. 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.

11. The pane of claim 10 wherein the insulating glass unit has an exterior solar reflectance of less than about 30%.

12. The pane of claim 11 wherein the exterior solar reflectance is less than about 20%.

13. The pane of claim 12 wherein the exterior solar reflectance is about 15%.

14. The pane of claim 10 wherein the insulating glass unit has an exterior visible reflectance of less than about 20%.

15. The pane of claim 10 wherein the insulating glass unit has a solar heat gain coefficient of less than about 0.4.

16. The pane of claim 10 wherein the insulating glass unit has a transmitted color characterized by an a_h color coordinate of between about −

0.5 and about −

3 and a b_h color coordinate of between about −

6.5 and about −

9.

17. The pane of claim 10 wherein the insulating glass unit has a reflected color characterized by an a_h color coordinate of between about 0.75 and about −

1.75 and a b_h color coordinate of between about −

9.75 and about −

12.25, said reflected color being viewed off the #1 surface of the insulating glass unit.

18. The pane of claim 10 wherein the insulating glass unit has a U Value of less than about 0.4.

19. The pane of claim 1 wherein the low-emissivity coating has an emissivity of less than about 0.12.

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

a) an inner coat comprising at least one transparent dielectric film;

b) a high absorption primary layer comprising material that is highly absorptive of solar radiation, the high absorption primary layer including at least about 100 angstroms of film;

c) a middle coat comprising at least one transparent dielectric film;

d) an infrared-reflective layer comprising material that is highly reflective of infrared radiation;

e) a high absorption blocker layer comprising material that is highly absorptive of solar radiation, the high absorption blocker layer including at least about 75 angstroms of film; and

f) an outer coat comprising at least one transparent dielectric film.

21. The pane of claim 20 wherein said infrared-reflective layer comprises silver.

22. The pane of claim 20 wherein the high absorption primary layer comprises titanium.

23. The pane of claim 22 wherein a major portion of the thickness of the high absorption primary layer is metallic titanium.

24. The pane of claim 20 wherein the high absorption blocker layer comprises titanium.

25. The pane of claim 24 wherein a major portion of the thickness of the high absorption blocker layer is metallic titanium.

26. The pane of claim 20 wherein the high absorption blocker layer is contiguous to said infrared-reflective layer.

27. The pane of claim 20 wherein the middle coat comprises a zinc oxide film deposited directly upon the high absorption primary layer.

28. The pane of claim 20 wherein the middle coat comprises a titanium dioxide film sandwiched between two zinc oxide films.

29. The pane of claim 28 wherein said titanium dioxide film has a thickness of between about 65 angstroms and about 103 angstroms, an innermost of said zinc oxide films has a thickness of between about 238 angstroms and about 422 angstroms, and an outermost of said zinc oxide films has a thickness of between about 80 angstroms and about 172 angstroms.

30. A method of producing coated substrates, the method comprising:

a) providing a pane having generally-opposed first and second major surfaces; and

b) depositing upon one of said major surfaces a low-emissivity coating comprising an infrared-reflective layer, a high absorption primary layer, and a middle coat, said infrared-reflective layer comprising material that is highly reflective of infrared radiation, the high absorption primary layer comprising material that is highly absorptive of solar radiation and including at least about 100 angstroms of film, and the middle coat comprising at least one transparent dielectric film and being positioned between the high absorption primary layer and the infrared-reflective layer.

31. The method of claim 30 wherein the method comprises depositing said infrared-reflective layer as a silver-containing film.

32. The method of claim 30 wherein the method comprises depositing said infrared-reflective layer at a thickness of at least about 50 angstroms.

33. The method of claim 30 wherein the method comprises depositing the high absorption primary layer as a titanium-containing film.

34. The method of claim 33 wherein the high absorption primary layer is deposited as metallic titanium.

35. The method of claim 30 wherein said infrared-reflective layer is deposited further from the pane than the high absorption primary layer.

36. The method of claim 30 further comprising depositing a high absorption blocker layer over said infrared-reflective layer, the high absorption blocker layer comprising material that is highly absorptive of solar radiation and including at least about 75 angstroms of film.

37. The method of claim 36 wherein the high absorption blocker layer is deposited directly over said infrared-reflective layer.

38. The method of claim 36 wherein the high absorption blocker layer is deposited as a titanium-containing film.

39. The method of claim 38 wherein the high absorption blocker layer is deposited as metallic titanium.

40. The method of claim 30 wherein the deposition of the middle coat comprises depositing a zinc oxide film directly upon the high absorption primary layer.

41. The method of claim 30 wherein the deposition of the middle coat comprises depositing a first intermediate zinc oxide film, an intermediate titanium dioxide film, and a second intermediate zinc oxide film.

42. The method of claim 41 wherein the first intermediate zinc oxide film is deposited at a thickness of between about 238 angstroms and about 422 angstroms, the intermediate titanium dioxide film is deposited at a thickness of between about 65 angstroms and about 103 angstroms, and the second intermediate zinc oxide films is deposited at a thickness of between about 80 angstroms and about 172 angstroms.

43. The method of claim 30 further comprising depositing an inner coat between the substrate and the high absorption primary layer and depositing an outer coat further from the substrate than said infrared-reflective layer, wherein the inner and outer coats each comprise at least one transparent dielectric film.