Coatings having low emissivity and low solar reflectance

• US 20030228472A1
• Filed: 04/25/2003
• Published: 12/11/2003
• 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: Eby, Eric, Hoffman, Wayne L.
• Granted Patent: US 7,067,195 B2
• Time in Patent Office: Days
• 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 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 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

, the middle coat comprising at least one transparent dielectric film and being positioned between said infrared-reflective layer and the high absorption primary layer.

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

3. The pane of claim 1 wherein said infrared-reflective layer has a thickness of between about 182 Å

and about 274 Å

.

4. The pane of claim 1 wherein a major portion of the thickness of the high absorption primary layer is a metallic material.

5. The pane of claim 1 wherein the high absorption primary layer comprises titanium and/or niobium.

6. The pane of claim 1 wherein the high absorption primary layer comprises a highly absorptive dielectric material.

7. The pane of claim 1 wherein the high absorption primary layer has a thickness of between about 104 Å

and about 151 Å

.

8. The pane of claim 1 wherein the middle coat has an optical thickness of between about 600 Å

and about 872 Å

.

9. The pane of claim 8 wherein each film of the middle coat has a refractive index of between about 1.7 and about 2.4.

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

11. 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

.

12. The pane of claim 11 wherein the high absorption blocker layer is deposited directly over said infrared-reflective layer.

13. The pane of claim 11 wherein a major portion of the thickness of the high absorption blocker layer is a metallic material.

14. The pane of claim 11 wherein the high absorption blocker layer comprises titanium and/or niobium.

15. The pane of claim 11 wherein the thickness of the high absorption blocker layer is between about 46 Å

and about 78 Å

.

16. The pane of claim 1 wherein the low-emissivity coating further comprises an inner coat comprising at least one transparent dielectric film and being positioned between the substrate and the high absorption primary layer.

17. The pane of claim 16 wherein the inner coat has an optical thickness of between about 216 Å

and about 312 Å

.

18. The pane of claim 17 wherein each film of the inner coat has a refractive index of between about 1.7 and about 2.4.

19. The pane of claim 1 wherein the low-emissivity coating further comprises an outer coat comprising at least one transparent dielectric film and being positioned further from the substrate than said infrared-reflective layer.

20. The pane of claim 19 wherein the outer coat has an optical thickness of between about 410 Å

and about 582 Å

.

21. The pane of claim 20 wherein each film in the outer coat has a refractive index of between about 1.7 and about 2.4.

22. 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.

23. The pane of claim 22 wherein the insulating glass unit has an exterior solar reflectance of less than about 30%.

24. The pane of claim 23 wherein the exterior solar reflectance is less than about 20%.

25. The pane of claim 24 wherein the exterior solar reflectance is about 16%.

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

27. The pane of claim 26 wherein the emissivity is less than about 0.05.

28. The pane of claim 27 wherein the emissivity is about 0.044.

29. The pane of claim 22 wherein the insulating glass unit has an exterior visible reflectance of less than about 20%.

30. The pane of claim 29 wherein the exterior visible reflectance is less than about 15%.

31. The pane of claim 30 wherein the exterior visible reflectance is about 11%.

32. The pane of claim 22 wherein the insulating glass unit has a U Value of less than about 0.4.

33. The pane of claim 32 wherein the U Value is less than about 0.3.

34. The pane of claim 33 wherein the U Value is about 0.25.

35. The pane of claim 22 wherein the insulating glass unit has a solar heat gain coefficient of less than about 0.4.

36. The pane of claim 22 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.

37. The pane of claim 22 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.

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

a) an inner coat comprising at least one transparent dielectric film and having an optical thickness of between about 216 Å and

about 312 Å

;

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

;

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 at least one transparent dielectric film and having an optical thickness of between about 410 Å and

about 582 Å

.

39. 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 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

, the middle coat comprising at least one transparent dielectric film and being positioned between said infrared-reflective layer and the high absorption primary layer.

40. The method of claim 39 wherein the method comprises depositing said infrared-reflective layer as a silver-containing film.

41. The method of claim 39 wherein the method comprises depositing said infrared-reflective layer at a thickness of between about 182 Å

and about 274 Å

.

42. The method of claim 39 wherein the method comprises depositing the high absorption primary layer as a metallic film.

43. The method of claim 39 wherein the method comprises depositing the high absorption primary layer as a titanium and/or niobium containing film.

44. The method of claim 39 wherein the method comprises depositing the high absorption primary layer as a highly absorptive dielectric film.

45. The method of claim 39 wherein the method comprising depositing the high absorption primary layer at a thickness of between about 104 Å

and about 151 Å

.

46. The method of claim 39 wherein the method comprises depositing the middle coat at an optical thickness of between about 600 Å

and about 872 Å

.

47. The method of claim 46 wherein the method comprises depositing each film of the middle coat as a film having a refractive index of between about 1.7 and about 2.4.

48. The method of claim 39 wherein the method comprises depositing said infrared-reflective layer further from the substrate than the high absorption primary layer.

49. The method of claim 48 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 having a thickness of at least about 45 Å

.

50. The method of claim 49 wherein the method comprises depositing the high absorption blocker layer directly over said infrared-reflective layer.

51. The method of claim 49 wherein the method comprises depositing the high absorption blocker layer as a metallic film.

52. The method of claim 49 wherein the method comprises depositing the high absorption blocker layer as a titanium and/or niobium containing film.

53. The method of claim 49 wherein the method comprises depositing the high absorption blocker layer at a thickness of between about 46 Å

and about 78 Å

.

54. The method of claim 39 further comprising depositing an inner coat between the substrate and the high absorption primary layer, the inner coat comprising at least one transparent dielectric film.

55. The method of claim 54 wherein the method comprises depositing the inner coat at an optical thickness of between about 216 Å

and about 312 Å

.

56. The method of claim 55 wherein the method comprises depositing each film of the inner coat as a film having a refractive index of between about 1.7 and about 2.4.

57. The method of claim 39 further comprising depositing an outer coat further from the substrate than said infrared-reflective layer, the outer coat comprising at least one transparent dielectric film.

58. The method of claim 57 wherein the method comprises depositing the outer coat at an optical thickness of between about 410 Å

and about 582 Å

.

59. The method of claim 58 wherein the method comprises depositing each film of the outer coat as a film having a refractive index of between about 1.7 and about 2.4.