Coating stack comprising a layer of barrier coating

1. A method of forming a multilayered coated substrate, comprising:

providing a substrate;

applying a first barrier layer over at least a portion of a substrate, wherein the first barrier layer has a permeability to oxygen of no greater than 10 grams per m 2 per day at a temperature of 900° F., and wherein the first barrier layer comprises a mixture of silica and alumina having greater than or equal to 40 wt. % silica;

applying a first dielectric layer over the first barrier layer;

applying at least one degradable metal layer over the first dielectric layer;

applying a primer layer over the at least one degradable metal layer;

applying a second dielectric layer over the primer layer; and

applying a second barrier layer over the second dielectric layer, wherein the second barrier layer has a permeability to oxygen of no greater than 10 grams per m 2 per day at a temperature of 900° F., and wherein the barrier layer comprises a mixture of silica and alumina having greater than or equal to 40 wt. % silica; and passing the multilayered coated substrate through a furnace having a line speed from 9 inches per minute (“ipm”) to 5 ipm, the resulting multilayered coated substrate has a visible light transmittance of at least 70 percent.

2. The method according to claim 1 , wherein the first barrier layer or the second barrier layer has a thickness from 50 Å to 5,400 Å.

3. The method according to claim 1 , wherein the applying the first barrier layer or the applying the second barrier layer step comprises depositing the first barrier layer or the second barrier layer by a magnetron sputtered vacuum deposition (“MSVD”) technique using a target comprising about 60 weight percent aluminum and 40 weight percent silicon.

4. The method according to claim 1 , wherein the primer has a thickness in the range from 10 Å to 18 Å.

5. The method according to claim 1 , wherein the permeability to oxygen for the first barrier layer or the second barrier layer is no greater than 5 g/m 2 /day.

6. The method according to claim 1 , wherein the permeability to oxygen for the first barrier layer or the second barrier layer is no greater than 0.6 g/m 2 /day.

7. The method according to claim 4 , wherein the primer is selected from the group consisting of titanium, aluminum, hafnium and a cobalt-chrome alloy.

8. The method according to claim 4 , wherein the primer is titanium.

9. The method according to claim 8 , wherein the primer has a thickness between 12 Å and 15 Å.

10. A method of forming a multilayered coated substrate, comprising:

forming a coating over a substrate, the coating comprising a radiation reflective metal layer over the substrate, a primer layer directly on the radiation reflective metal layer, and a first barrier layer over the primer layer; wherein

the barrier layer has a permeability to oxygen of no greater than 10 grams per m 2 per day at a temperature of 900° F., and wherein the barrier layer comprises a mixture of silica and alumina having greater than or equal to 40 wt. % silica; and

passing the coated substrate through a furnace having a line speed from 9 ipm to 5 ipm, wherein the resulting multilayered coated substrate has a visible light transmittance of at least 70 percent.

11. The method according to claim 10 , wherein the second barrier layer is the outermost layer of the coating.

12. The method according to claim 10 , wherein the first barrier layer is the outermost layer of the coating.

13. The method according to claim 10 , wherein the first barrier layer comprises about 60 weight percent alumina and about 40 weight percent silica.

14. The method according to claim 10 , wherein the primer has a thickness in the range from 10 Å to 18 Å.

15. The method according to claim 10 , wherein the permeability to oxygen for the first barrier layer is no greater than 5 g/m 2 /day.

16. The method according to claim 10 , wherein the permeability to oxygen for the first barrier layer is no greater than 0.6 g/m 2 /day.

17. The method according to claim 14 , wherein the primer is selected from the group consisting of titanium, aluminum, hafnium and a cobalt-chrome alloy.

18. The method according to claim 14 , wherein the primer is titanium.

19. The method according to claim 18 , wherein the primer has a thickness between 12 Å and 15 Å.

20. The method according to claim 11 further comprising providing a second barrier layer between the coating and the substrate, wherein the barrier layer has a permeability to oxygen of no greater than 10 grams per m 2 per day at a temperature of 900° F., and wherein the barrier layer comprises a mixture of silica and alumina having greater than or equal to 40 wt. % silica.

21. A method of forming a multilayered coated substrate, comprising:

applying a first layer on a substrate;

applying a first metal layer over the first layer;

applying a first primer layer over the first metal layer;

applying a second layer over the first primer layer;

applying a second metal layer over the second layer;

applying a second primer layer over the second metal layer;

applying a third layer over the second metal layer;

applying a barrier coating over the third layer; wherein the barrier layer has a permeability to oxygen of no greater than 10 grams per m 2 per day at a temperature of 900° F., and wherein the barrier layer comprises a mixture of silica and alumina having greater than or equal to 40 wt. % silica; and passing the multilayered coated substrate through a furnace having a line speed from 9 ipm to 5 ipm, the resulting multilayered coated substrate has a visible light transmittance of at least 70 percent.

22. The method according to claim 21 , wherein the first layer, the second layer or the third layer comprises zinc stannate.

23. The method according to claim 21 , wherein the first metal layer or the second metal layer comprises silver.

24. The method according to claim 21 , wherein the first primer layer or the second primer layer comprises titanium.