CARBON NANOTUBE GLAZING TECHNOLOGY

• US 20080280078A1
• Filed: 06/29/2007
• Published: 11/13/2008
• Est. Priority Date: 06/30/2006
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Inventors: Burrows, Keith J., Krisko, Annette J.
• Granted Patent: US 7,754,336 B2
• Time in Patent Office: Days
• US Class Current: 428/34
• CPC Class Codes: B32B 17/06 comprising glass as the main or only constituent of a layer, next to another layer of a specific material
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10743 containing acrylate (co)polymers or salts thereof
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 17/22 with other inorganic material C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 2217/42 consisting of particles only
• CPC Class Codes: C03C 2217/45 Inorganic continuous phases
• CPC Class Codes: C03C 2217/475 Inorganic materials
• CPC Class Codes: C03C 2217/91 Coatings containing at least one layer having a composition gradient through its thickness
• CPC Class Codes: E06B 3/67 characterised by additional arrangements or devices for heat or sound insulation or for controlled passage of light
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

The invention provides a glazing that includes a substrate on which there is provided a coating comprising carbon nanotubes. The glazing can be an IG unit comprising two spaced-apart panes bounding a between-pane space, the IG unit having at least one exterior surface on which there is provided a transparent conductor coating comprising carbon nanotubes. The glazing can alternatively be a laminated glass assembly comprising two panes of glass and an interlayer comprising carbon nanotubes sandwiched therebetween. Monolithic substrate embodiments are also provided. In certain embodiments, the coating comprises both dielectric film and carbon nanotubes.

Claims

1. A multiple-pane insulating glazing unit including at least two spaced-apart panes, the insulating glazing unit having at least one between-pane space and having a desired surface on which there is provided a transparent conductor coating comprising carbon nanotubes, the desired surface being an exterior surface of the unit rather than being an interior surface facing a between-pane space of the unit.

2. The insulating glazing unit of claim 1 wherein the transparent conductor coating has a thickness, nanotube coverage, and composition selected to provide the unit with a Δ

U of at least about 0.03, the Δ

U being defined as an absolute value of a difference between U value of the unit with the transparent conductor coating and U value of the unit without the transparent conductor coating.

3. The insulating glazing unit of claim 2 wherein the transparent conductor coating has a thickness of less than 10,000 angstroms and yet the Δ

U is at least about 0.03.

4. The insulating glazing unit of claim 1 wherein the transparent conductor coating consists essentially of carbon nanotubes and inorganic material, the coating being durable to heat treatment at elevated temperatures exceeding 600 degrees C. such that the coating remains transparent in response to such heat treatment rather than browning or otherwise turning opaque.

5. The insulating glazing unit of claim 1 wherein the transparent conductor coating consists essentially of carbon nanotubes and dielectric material, the coating being characterized by a dielectric/carbon nanotube weight ratio of between about 2.3 and about 999, the dielectric/carbon nanotube weight ratio being defined as the total weight of the dielectric material over the total weight of the carbon nanotubes.

6. The insulating glazing unit of claim 5 wherein the dielectric/carbon nanotube weight ratio is between about 9 and about 999.

7. The insulating glazing unit of claim 5 wherein the dielectric material is selected from the group consisting of metal oxides, metal nitrides, and metal oxynitrides.

8. The insulating glazing unit of claim 5 wherein the carbon nanotubes are encased in a matrix of the dielectric material.

9. The insulating glazing unit of claim 5 wherein the dielectric material is an amorphous or substantially amorphous dielectric material selected from the group consisting of silica, silicon nitride, and silicon oxynitride.

10. The insulating glazing unit of claim 1 wherein the desired surface is either a #4 surface or a #6 surface of the unit, and wherein the unit is mounted in a frame on a wall of a building, the unit having a #1 surface exposed to an outdoor environment and a #2 surface exposed to a between-pane space of the unit, the desired surface being a room-side surface exposed to an indoor environment of the building, wherein the carbon nanotubes cover less than 100% of the room-side surface, and the coating includes a transparent dielectric film encasing the carbon nanotubes.

11. The insulating glazing unit of claim 10 wherein the carbon nanotubes cover less than about 50 percent of the room-side surface.

12. The insulating glazing unit of claim 10 wherein the carbon nanotubes cover less than about 30 percent of the room-side surface.

13. The insulating glazing unit of claim 1 wherein the unit has a U value of less than 0.24.

14. The insulating glazing unit of claim 13 wherein the U value is less than 0.21.

15. The insulating glazing unit of claim 1 wherein the transparent conductor coating provides an emissivity of less than about 0.25.

16. The insulating glazing unit of claim 1 wherein the transparent conductor coating has a thickness, nanotube coverage, and composition selected to provide a Δ

T_v of less than about 5%, the Δ

T_v being defined as an absolute value of a difference between visible transmittance of the unit with the transparent conductor coating and visible transmittance of the unit without the transparent conductor coating.

17. The insulating glazing unit of claim 1 wherein the unit has a visible transmission between about 30% and about 75%.

18. The insulating glazing unit of claim 1 wherein the unit has a #2 surface on which there is provided a low-emissivity coating, the low-emissivity coating comprising at least one infrared-reflective film comprising silver, said infrared-reflective film being located between two transparent dielectric films.

19. The insulating glazing unit of claim 18 wherein the unit has a #1 surface on which there is provided a water-sheeting coating.

20. The insulating glazing unit of claim 19 wherein the water-sheeting coating includes silica, titania, or both, and wherein the transparent conductor coating, the low-emissivity coating, and the water-sheeting coating have a combined physical thickness of between 1,000 angstroms and 10,000 angstroms.

21. The insulating glazing unit of claim 19 wherein the transparent conductor coating, the low-emissivity coating, and the water-sheeting coating have a combined physical thickness of between about 1,000 angstroms and about 5,000 angstroms.

22. The insulating glazing unit of claim 1 where the unit has a transmitted color characterized by an a_h color coordinate of between about 0 and about −

6 and a b_h color coordinate of between about +6 and about −

6.

23. The insulating glazing unit of claim 10 wherein the unit has an exterior reflected color characterized by an a_h color coordinate of between about +2 and about −

6 and a b_h color coordinate of between about +6 and about −

6.

24. The insulating glazing unit of claim 1 wherein the transparent conductor coating has a thickness of less than 10,000 angstroms.

25. The insulating glazing unit of claim 1 wherein the transparent conductor coating has a thickness of less than about 1,500 angstroms.

26. The insulating glazing unit of claim 1 wherein the desired surface is a #1 surface of the unit, and the unit is mounted in a frame on a wall of a building, the #1 surface being exposed to an outdoor environment, the unit having a #2 surface exposed to a between-pane space of the unit.

27. The insulating glazing unit of claim 26 wherein the unit has a room-side surface exposed to an indoor environment, the room-side surface bearing a second transparent conductor coating comprising carbon nanotubes.

28. The insulating glazing unit of claim 27 wherein the room-side surface is either a #4 surface of the unit or a #6 surface of the unit.

29. A glazing comprising a transparent pane having a major surface on which there is provided a coating consisting essentially of dielectric film and carbon nanotubes, the coating having a thickness of less than 10,000 angstroms, wherein the coating has a dielectric/carbon nanotube weight ratio of between about 2.3 and about 9999, the dielectric/carbon nanotube weight ratio being defined as the total weight of the dielectric film over the total weight of the carbon nanotubes.

30. The glazing of claim 29 wherein the coating consists essentially of carbon nanotubes and a dielectric material selected from the group consisting of metal oxides, metal nitrides, and metal oxynitrides, wherein the coating is durable to heat treatment at elevated temperatures exceeding 600 degrees C. such that the coating remains transparent in response to such heat treatment rather than browning or otherwise turning opaque.

31. The glazing of claim 29 wherein the dielectric film is an electrically non-conductive dielectric material.

32. The glazing of claim 29 wherein the dielectric film is an amorphous or substantially amorphous dielectric material selected from the group consisting of silica, silicon nitride, and silicon oxynitride.

33. The glazing of claim 29 wherein the carbon nanotubes are encased in the dielectric film.

34. The glazing of claim 29 wherein the thickness of the coating is less than 4,000 angstroms.

35. The glazing of claim 34 wherein the thickness is less than 1,500 angstroms.

36. The glazing of claim 29 wherein the major surface has a total surface area of which the carbon nanotubes cover less than about 50 percent.

37. The glazing of claim 36 wherein the carbon nanotubes cover less than about 30 percent of the total surface area of the major surface.

38. The glazing of claim 29 wherein the carbon nanotubes provide coverage over at least about 1-2 percent of the major surface.

39. The glazing of claim 29 wherein the coating has a surface resistance of less than about 20 ohms per square.

40. The glazing of claim 29 wherein the coated transparent pane has a monolithic transmission of at least about 70 percent.

41. The glazing of claim 29 wherein the glazing includes a further pane on which there is provided a coating comprising three infrared-reflective films each comprising silver.

42. A laminated glass assembly comprising first and second panes of glass, the first pane having a bonded interior surface and an exposed exterior surface, the second pane having a bonded interior surface and an exposed exterior surface, wherein between the first and second panes of glass there is an interlayer that holds the two glass panes together, the interior surfaces of the first and second panes being bonded to the interlayer, and wherein the interlayer comprises carbon nanotubes.

43. The laminated glass assembly of claim 42 wherein the interlayer comprises a polymeric layer, the carbon nanotubes being embedded with or otherwise contiguous to the polymeric layer.

44. The laminated glass assembly of claim 42 wherein the interlayer comprises the carbon nanotubes and a polymer, the interlayer having a carbon nanotube/polymer weight ratio of between about 0.0001 and about 1.0, the carbon nanotube/polymer weight ratio being defined as the total weight of the carbon nanotubes over the weight of the polymer in the interlayer.