Novel silver barrier materials for low-emissivity applications

• US 20140177042A1
• Filed: 12/21/2012
• Published: 06/26/2014
• Est. Priority Date: 12/21/2012
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Intermolecular Incorporated, Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Hassan, Mohd Fadzli Anwar, Boyce, Brent, Ding, Guowen, Le, Minh Huu, Sun, Zhi-Wen Wen, Wang, Yu, Xu, Yongli
• Granted Patent: US 9,448,345 B2
• Time in Patent Office: Days
• US Class Current: 359/360
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• 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 17/40 all coatings being metal coatings
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: C22C 27/02 Alloys based on vanadium, niobium, or tantalum
• CPC Class Codes: C22C 5/06 Alloys based on silver
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection

Abstract

A method for making low emissivity panels, including control the composition of a barrier layer formed on a thin conductive silver layer. The barrier structure can include an alloy of a first element having high oxygen affinity with a second element having low oxygen affinity. The first element can include Ta, Nb, Zr, Hf, Mn, Y, Si, and Ti, and the second element can include Ru, Ni, Co, Mo, and W, which can have low oxygen affinity property. The alloy barrier layer can reduce optical absorption in the visible range, can provide color-neutral product, and can improve adhesion to the silver layer.

Claims

1. A method to form a low emissivity coating, comprising

providing a transparent substrate;

forming a first layer on the transparent substrate, wherein the first layer comprises silver, wherein the first layer is operable as an infrared reflective layer;

forming a second layer on the first layer, wherein the second layer is operable as a barrier layer,

wherein the second layer comprises an alloy of a first and a second element,

wherein the first element comprises materials having higher enthalpy of oxide formation than the second element,

wherein the alloy comprises between 85 wt % and 50 wt % of the first element and between 15 wt % and 50 wt % of the second element.

2. A method as in claim 1 wherein the first element comprises materials having enthalpy of oxide formation greater than 1200 kJ/mol in magnitude.

3. A method as in claim 1 wherein the second element comprises materials having enthalpy of oxide formation less than 600 kJ/mol in magnitude.

4. A method as in claim 1 wherein the first and second elements comprise materials having solubility of less than 100 ppm in weight in silver at temperature less than 500 C.

5. A method as in claim 1 wherein the first and second elements comprise materials having extinction coefficients less than 5.

6. A method as in claim 1 wherein the first and second elements comprise materials having extinction coefficients of the oxide forms to be less than 5.

7. A method to form a low emissivity coating, comprising

providing a transparent substrate;

forming a first layer on the transparent substrate, wherein the first layer comprises silver, wherein the first layer is operable as an infrared reflective layer;

forming a second layer on the first layer, wherein the second layer is operable as a barrier layer,

wherein the second layer comprises an alloy of a first and a second elements,

wherein the first element comprises one of Ta, Nb, Zr, Hf, Mn, Y, Si, Ti, or any combination thereof,

wherein the second element comprises one of Ru, Ni, Co, Mo, and W, or any combination thereof,

wherein the alloy comprises between 85 wt % and 50 wt % of the first element and between 15 wt % and 50 wt % of the second element.

8. A method as in claim 7 wherein the alloy comprises greater than 65 wt % of the first element.

9. A method as in claim 7 wherein the alloy comprises between 85 wt % and 65 wt % of the first element.

10. A method as in claim 7 wherein the alloy comprises less than 35 wt % of the second element.

11. A method as in claim 7 wherein the alloy comprises between 35 wt % and 15 wt % of the second element.

12. A method as in claim 7 wherein the first element comprises Nb or Ti, and wherein the second element comprises Ni.

13. A method as in claim 7, further comprising

forming a seed layer between the substrate and the first layer, wherein the seed layer comprises a crystal orientation that promotes a (111) crystal orientation of the first layer.

14. A low emissivity panel, comprising

a transparent substrate;

a first layer disposed on the transparent substrate, wherein the first layer comprises silver, wherein the first layer is operable as an infrared reflective layer;

a second layer disposed on the first layer, wherein the second layer is operable as a barrier layer,

wherein the second layer comprises an alloy of a first and a second element,

wherein the first element comprises one of Ta, Nb, Zr, Hf, Mn, Y, Si, Ti, or any combination thereof,

wherein the second element comprises one of Ru, Ni, Co, Mo, W, or any combination thereof,

wherein the alloy comprises between 85 wt % and 50 wt % of the first element and between 15 wt % and 50 wt % of the second element.

15. A panel as in claim 14 wherein the alloy comprises greater than 65 wt % of the first element.

16. A panel as in claim 14 wherein the alloy comprises between 85 wt % and 65 wt % of the first element.

17. A panel as in claim 14 wherein the alloy comprises less than 35 wt % of the second element.

18. A panel as in claim 14 wherein the alloy comprises between 35 wt % and 15 wt % of the second element.

19. A panel as in claim 14 wherein the first element comprises Nb or Ti, and wherein the second element comprises Ni.

20. A panel as in claim 14, further comprising

a seed layer between the substrate and the first layer, wherein the seed layer comprises a crystal orientation that promotes a (111) crystal orientation of the first layer.