Insulating glass unit with crack-resistant low-emissivity suspended film

• US 8,530,011 B2
• Filed: 12/13/2010
• Issued: 09/10/2013
• Est. Priority Date: 12/13/2010
• Status: Expired due to Fees

• Current Assignee: Southwall Technologies, Inc. (Eastman Chemical Company)
• Original Assignee: Southwall Technologies, Inc. (Eastman Chemical Company)
• Inventors: Kleinhempel, Ronny, Kozak, Julius G., Thielsch, Roland C., Wipfler, Richard T., Stoessel, Christian H., Boman, Lee C.
• Primary Examiner(s): Loney, Donald J
• Application Number:
  US12/966,469
• Publication Number:
  US 20120148863A1
• Time in Patent Office: 1,002 Days
• Field of Search: 428/34, 428/698, 428/699, 428/700, 428/701, 428/702, 527/861, 527/861.1, 156/107, 156/109
• US Class Current: 428/34
• CPC Class Codes: B32B 2307/736 Shrinkable
• CPC Class Codes: E06B 3/6715 specially adapted for increased thermal insulation or for controlled passage of light E06B3/66323 takes precedence; coating of glass pains C03C17/00; devices or arrangements for controlling the intensity, colour, phase, polarisation or direction of light G02F1/00
• CPC Class Codes: Y10T 428/12542 More than one such component
• CPC Class Codes: Y10T 428/12549 Adjacent to each other
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A low-e insulating glass unit has a suspended, coated IR reflecting polymer sheet under tension, e.g. from heat shrinkage. The polymer sheet is coated with a multilayer stack of dielectric and metallic layers, including at least one silver layer deposited upon a zinc oxide seed layer that is at most 15 nm thickness. The use of zinc oxide ensures good seeding for high quality silver layer growth, thereby providing low emissivity. The thinness of the zinc oxide ensures that it resists cracking when the polymer sheet is tensioned.

Claims

1. An insulating glass unit, comprising:

a pair of glass panes in a parallel, spaced apart relation; and

at least one transparent, heat-shrunk, tensioned polymer sheet in a spaced apart parallel relation between the glass panes, at least one surface of at least one polymer sheet having a substantially transparent coating comprising a composite multilayer stack of dielectric and metallic layers, the stack comprising an amorphous indium oxide dielectric layer about 20 to about 80 nm thick in contact with the polymer sheet, a crystalline zinc oxide seed layer about 5 to about 15 nm thick deposited on the amorphous indium oxide dielectric layer, at least one low-emissivity silver layer grown upon the zinc oxide seed layer, and an indium oxide protective layer.

2. The insulating glass unit as in claim 1, wherein the polymer sheet is polyethylene terephthalate.

3. The insulating glass unit as in claim 1, wherein the zinc oxide seed layer has a thickness in a range between 5 and 10 nm.

4. The insulating glass unit as in claim 1, wherein the multilayer stack further comprises a cap layer comprising nichrome, titanium, zinc aluminum alloy or nichrome nitride at most 5 nm thick coated on top of the silver layer.

5. The insulating glass unit as in claim 1, wherein the silver layer has a thickness in a range between 5 and 60 nm.

6. The insulating glass unit as in claim 1, wherein the indium oxide protective layer has a thickness in a range between 20 and 60 nm.

7. The insulating glass unit as in claim 1, wherein the multilayer stack further comprises one or more sequences of zinc oxide seed layer, silver layer and indium oxide protective layer, each zinc oxide seed layer having a thickness of 5 to 15 nm, and the total cumulative thickness of all silver layers being at most 60 nm.

8. The insulating glass unit as in claim 1, wherein the indium oxide protective layer is deposited on the silver layer.

9. The insulating glass unit as in claim 1, wherein the multilayer stack is coated upon both surfaces of at least one polymer sheet.

10. The insulating glass unit as in claim 1, which comprises two or more transparent polymer sheets supported under tension by a frame in parallel, spaced apart relation to each other between the glass panes.

11. A process for the preparation of a insulating glass unit, comprising:

(i). coating a polymer sheet with a series of layers, the layers comprising an amorphous indium oxide layer having a thickness of about 20 to about 80 nanometers on the surface of the polymer sheet;

a crystalline, zinc-based oxide seed layer having a thickness about 5 to about 10 nanometers on the surface on the amorphous indium oxide layer; and

a silver layer having a thickness of about 5 to about 60 nanometers on the surface of the zinc-based oxide seed layer to produce a coated, polymer sheet transparent to visible light;

(iI). bonding the coated, polymer sheet to two or more spacers between a pair of glass panes to produce an assembled glass unit having the coated, polymer sheet suspended in a spaced apart and parallel relation to the pair of glass panes; and

(iii). heat shrinking the coated polymer sheet.

12. The process as in claim 11, wherein the polymer sheet comprises polyethylene terephthalate.

13. The process as in claim 11, wherein the series of layers further comprise a cap layer on top of the silver layer, the cap layer comprising nichrome, titanium, zinc aluminum alloy or nichrome nitride at most 5 nm thick.

14. The process as in claim 11, wherein the series of layers is coated upon both surfaces of the polymer sheet.