CONDUCTIVE MULTILAYER STACK

• US 20100028684A1
• Filed: 09/25/2008
• Published: 02/04/2010
• Est. Priority Date: 07/31/2008
• Status: Abandoned Application

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Bimanand, Alexander, Mariscal, Jose
• Application Number:
  US12/238,069
• Publication Number:
  US 20100028684A1
• Time in Patent Office: Days
• US Class Current: 428/413
• CPC Class Codes: B64C 1/1476 Canopies; Windscreens or similar transparent elements
• CPC Class Codes: C03C 17/42 at least one coating of an organic material and at least one non-metal coating
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31609 Particulate metal or metal compound-containing
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

An electrically conductive multilayer stack having good IR reflection, radar attenuation, static discharge, and other desirable properties includes a coated substrate, a primary conductive layer, and a secondary protective stack having greater durability and functionality then conventional multilayer stacks used to protect aircraft canopies and other substrates. The secondary protective stack includes at least one conductive layer that helps dissipate static charge.

Claims

1. An electrically conductive multilayer stack, comprising:

a coated substrate;

a primary conductive layer containing a metal oxide and a metal layer, disposed over the coated substrate; and

a secondary protective stack including at least one conductive layer, disposed over the primary conductive layer.

2. The multilayer stack of claim 1, wherein the substrate is an aircraft canopy.

3. The multilayer stack of claim 1, wherein the coated substrate comprises a substrate, a tie layer disposed over the substrate, and a substrate base layer disposed over the tie layer.

4. The multilayer stack of claim 3, wherein the base layer comprises an organopolysiloxane.

5. The multilayer stack of claim 4, wherein the organopolysiloxane is compounded with a silane or siloxane.

6. The multilayer stack of claim 1, wherein the primary conductive layer comprises a first metal oxide layer, a metal layer disposed over the first metal oxide layer, and a second metal oxide layer disposed over the metal layer.

7. The multilayer stack of claim 6, wherein the first and second metal oxide layers are comprised of indium tin oxide, titanium dioxide, zinc oxide, or zinc stannate.

8. The multilayer stack of claim 6, wherein the first and second metal oxide layers comprise indium tin oxide.

9. The multilayer stack of claim 6, wherein the metal layer comprises silver or a silver alloy.

10. The multilayer stack of claim 9, wherein the silver alloy comprises silver/palladium or silver/gold.

11. The multilayer stack of claim 6, wherein the metal layer is coated with a layer of titanium.

12. The multilayer stack of claim 1, wherein the secondary protective stack includes a first tie layer, a hydrophobic barrier layer disposed over the first tie layer, a second tie layer disposed over the barrier layer, and a conductive topcoat disposed over the second tie layer.

13. The multilayer stack of claim 12, wherein the first tie layer comprises a material compatible with a metal oxide and the barrier layer.

14. The multilayer stack of claim 12, wherein the second tie layer comprises a material compatible with the barrier layer and the topcoat.

15. The multilayer stack of claim 12, wherein the barrier layer comprises a material selected from the group consisting of polyurethanes, fluorinated urethanes, fluoropolymers, fluoroelastomers, polyurethanes, polyolefins, polyamides, polyamines, halopolymers, ethylene propylene rubbers, epoxies, polyesters, and fluorosilicones.

16. The multilayer stack of claim 12, further comprising a primer coat between the first tie layer and the barrier layer.

17. The multilayer stack of claim 16, wherein the primer coat comprises 3-aminopropyltriethoxy silane.

18. The multilayer stack of claim 12, wherein the topcoat comprises a polyurethane formed from a polyol, aliphatic polyisocyanate resin, Di acytone alcohol, and a conductive agent.

19. The multilayer stack of claim 18, wherein the conductive agent comprises a quaternary ammonium salt, a conductive metal oxide, or an inherently conductive polymer.

20. The multilayer stack of claim 19, wherein the conductive agent comprises a quaternary ammonium salt.

21. The multilayer stack of claim 20, wherein the quaternary ammonium salt is provided in the topcoat at a concentration of from about 22 to 60 wt %.

22. The multilayer stack of claim 21, wherein the quaternary ammonium salt concentration is about 22 to 35 wt %.

23. The multilayer stack of claim 20, wherein the quaternary ammonium salt is provided in the topcoat at a concentration of greater than or equal to 60 wt %.

24. The multilayer stack of claim 18, wherein the conductive agent comprises a non-reactive organic salt selected from the group consisting of 1-butyl-3-methylimidazolium methyl sulfonate, 1-butyl-3-methylimidazolium methyl sulfate, and 1-butyl-3-methylimidazolium ethyl sulfate.

25. The multilayer stack of claim 24, wherein the non-reactive organic salt is present at a concentration of about 1 to 5 wt %.

26. The multilayer stack of claim 12, wherein the conductive agent comprises a conductive metal oxide.

27. The multilayer stack of claim 26, wherein the conductive metal oxide comprises indium tin oxide.

28. The multilayer stack of claim 27, wherein the indium tin oxide is provided as nanoparticles.

29. The multilayer stack of claim 12, wherein the conductive agent comprises an inherently conductive polymer.

30. The multilayer stack of claim 29 wherein the inherently conductive polymer comprises a polythiophene-based polymer.

31. The multilayer stack of claim 30 wherein the polythiophene-based polymer is poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate).

32. The multilayer stack of claim 12, wherein the first tie layer, second tie layer, and/or barrier layer contain a conductive agent selected from the group consisting of quaternary ammonium salts, conductive metal oxides, and inherently conductive polymers.

33. The multilayer stack of claim 12, wherein the first tie layer contains a conductive metal oxide.

34. The multilayer stack of claim 12, wherein the second tie layer contains a conductive metal oxide.

35. The multilayer stack of claim 12, wherein the barrier layer contains a conductive metal oxide.