Flexible electrically conductive film

• US 20040033369A1
• Filed: 08/17/2002
• Published: 02/19/2004
• Est. Priority Date: 08/17/2002
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Koster, Brian Leroy, Fleming, Robert James, Bright, Clark Ivan, Zelinsky, Maria Lenni, Anderson, Edward John, Lyons, Christopher Stewart
• Granted Patent: US 6,933,051 B2
• Time in Patent Office: Days
• US Class Current: 428/431
• CPC Class Codes: B32B 17/10005 laminated safety glass or glazing
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/10706 being photo-polymerized
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/10816 by pressing
• CPC Class Codes: B32B 2038/0076 Curing, vulcanising, cross-linking
• CPC Class Codes: B32B 2038/0092 Metallizing
• CPC Class Codes: B32B 2309/62 Inert
• CPC Class Codes: B32B 2309/68 Vacuum
• CPC Class Codes: B32B 2310/14 Corona, ionisation, electrical discharge, plasma treatment
• CPC Class Codes: B32B 2329/06 PVB, i.e. polyinylbutyral
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 38/0008 Electrical discharge treatment, e.g. corona, plasma treatment; wave energy or particle radiation heat treatment B32B38/0036
• CPC Class Codes: B32B 7/10 at least one layer having inter-reactive properties
• CPC Class Codes: C23C 14/562 for coating elongated substrates
• CPC Class Codes: H05B 2203/017 Manufacturing methods or apparatus for heaters
• CPC Class Codes: H05B 3/86 the heating conductors being embedded in the transparent or reflecting material H05B3/845 takes precedence
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/3162 : Cross-linked polyester [e.g., glycerol maleate-styrene, etc.]
• CPC Class Codes: Y10T 428/3163 : Next to acetal of polymerized unsaturated alcohol [e.g., formal butyral, etc.]
• CPC Class Codes: Y10T 428/31649 : Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31699 : Ester, halide or nitrile of addition polymer

Abstract

An electrically conductive film contains electrically connected first and second visible light-transmissive metal or metal alloy layers separated by a visible light-transmissive crosslinked polymeric layer. The film can be joined or laminated into glazing (especially non-planar vehicular safety glazing) with reduced likelihood that the metal or metal alloy layers will be damaged or distorted. The film also can transparently shield a device that can cause or is sensitive to electromagnetic interference with reduced likelihood that the metal or metal alloy layers will fracture.

Claims

1. A process for making an electrically conductive visible light-transmissive film comprising:

a) providing a visible light-transmissive flexible support,

b) forming a visible light-transmissive first metal or metal alloy layer atop the support,

c) forming an organic layer atop the first metal or metal alloy layer,

d) crosslinking the organic layer to form a visible light-transmissive crosslinked polymeric layer,

e) forming a visible light-transmissive second metal or metal alloy layer atop the crosslinked polymeric layer, and

f) connecting one or more electrodes to at least one of the first and second metal or metal alloy layers.

2. A process according to claim 1 wherein the crosslinked polymeric layer is formed by flash evaporation, vapor deposition and crosslinking of a radiation-crosslinkable monomer.

3. A process according to claim 1 wherein the metal or metal alloy layers comprise silver and the crosslinked polymeric layer comprises an acrylate polymer.

4. A process according to claim 1 further comprising forming a base coat layer between the support and the first metal or metal alloy layer.

5. A process according to claim 1 further comprising modifying an interface between the metal or metal alloy layers and adjacent layers within the film to enhance interlayer adhesion.

6. A process according to claim 5 wherein plasma treatment is employed between each metal or metal alloy layer and adjacent layers within the film.

7. A process according to claim 1 wherein the film is extensible.

8. A process according to claim 1 further comprising stretching the film without substantial cracking or creasing of the metal or metal alloy layers.

9. A process according to claim 7 wherein the film, if heated, exhibits different shrinkage in two in-plane directions.

10. A process according to claim 1 comprising connecting electrodes to both the first and second metal or metal alloy layers so that the film can be electrically heated.

11. A process for making an electrically heatable glazing article, comprising:

a) assembling a layer of glazing material and a visible light-transmissive film comprising first and second visible light-transmissive metal or metal alloy layers separated by a visible light-transmissive crosslinked polymeric layer,

b) bonding the glazing material and film together into a unitary article, and

c) connecting one or more electrodes to at least one of the metal or metal alloy layers.

12. A process according to claim 11 wherein the electrodes are connected to the metal or metal alloy layers after bonding.

13. A process according to claim 11 wherein the electrodes are connected to the metal or metal alloy layers before bonding.

14. A process according to claim 11 wherein the glazing article comprises architectural glazing and the electrodes are connected to both the first and second metal or metal alloy layers.

15. A process for making an electrically heatable laminate article comprising:

a) assembling a first glazing material layer, a first mechanical energy-absorbing layer, a visible light-transmissive flexible film layer comprising first and second metal or metal alloy layers separated by a crosslinked polymeric layer, electrodes that permit electrical current to be supplied to the metal or metal alloy layers, a second mechanical energy-absorbing layer and a second glazing material layer,

b) removing residual air from between the layers, and

c) heating and applying pressure to the layers to bond the layers and electrodes together into a unitary article.

16. A process according to claim 15 wherein the removal of residual air or the application of pressure to the layers is performed using at least one nip roll.

17. A process according to claim 15 wherein the glazing material layers are non-planar.

18. A process according to claim 15 wherein the layers are bonded together without substantial cracking or creasing of the metal or metal alloy layers and without substantial wrinkling of the film.

19. A process according to claim 15 wherein the film is extensible.

20. A process according to claim 15 wherein the film is stretched without substantial cracking or creasing of the metal or metal alloy layers.

21. A process according to claim 15 wherein the crosslinked polymeric layer comprises an acrylate polymer.

22. An electrically conductive visible light-transmissive film comprising electrically connected first and second visible light-transmissive metal or metal alloy layers separated by a visible light-transmissive crosslinked polymeric layer.

23. A film according to claim 22 further comprising a flexible plastic support.

24. A film according to claim 23 further comprising a polymeric base coat layer between the support and the first metal or metal alloy layer.

25. A film according to claim 23 wherein an interface between the metal or metal alloy layers and adjacent layers within the film has been subjected to an adhesion-enhancing treatment, or one or more of the adjacent layers comprises an adhesion-enhancing adjuvant, whereby the interlayer adhesion is increased.

26. A film according to claim 25 wherein each of the metal or metal alloy layers and adjacent layers has been subjected to plasma treatment.

27. A film according to claim 23 wherein the film is stretched.

28. A film according to claim 23 wherein the film is extensible.

29. A film according to claim 22 further comprising one or more pairs of an additional crosslinked polymeric spacing layer and an additional metal or metal alloy layer atop the second metal layer.

30. A film according to claim 22 wherein the metal or metal alloy layers comprise silver and the crosslinked polymeric layer comprises an acrylate polymer.

31. A film according to claim 22 wherein the film can be laminated into an automotive windshield without substantial wrinkling.

32. A film according to claim 22 wherein each of the layers is electrically connected.

33. A safety glazing pre-laminate comprising at least one layer of a mechanical energy-absorbing material joined to a visible light-transmissive film comprising first and second visible light-transmissive metal or metal alloy layers separated by a visible light-transmissive crosslinked polymeric layer and further comprising electrodes that permit electrical current to be supplied to the metal or metal alloy layers.

34. An electrically heatable glazing article comprising at least one layer of a glazing material joined to a visible light-transmissive film comprising first and second visible light-transmissive metal or metal alloy layers separated by a visible light-transmissive crosslinked polymeric layer and further comprising electrodes that permit electrical current to be supplied to the metal or metal alloy layers.

35. An article according to claim 34 wherein an interface between the metal or metal alloy layers and adjacent layers within the film has been subjected to an adhesion-enhancing treatment, or one or more of the adjacent layers comprises an adhesion-enhancing adjuvant, whereby the interlayer adhesion is increased.

36. An article according to claim 35 wherein one or more of the metal or metal alloy layers or adjacent layers has been subjected to plasma treatment.

37. An article according to claim 34 wherein the metal or metal alloy layers comprise silver and the crosslinked polymeric layer comprises an acrylate polymer.

38. An article according to claim 34 wherein the glazing material comprises non-planar glass and the article is optically clear and infrared-reflective.

39. An article according to claim 34 comprising a windshield.

40. An article according to claim 34 comprising architectural glazing.

41. A vehicle with electrically heatable glazing comprising at least one windshield, backlight, side window or skylight comprising a film comprising first and second visible light-transmissive metal or metal alloy layers separated by a crosslinked visible light-transmissive polymeric layer and further comprising electrodes that permit electrical current to be supplied to the metal or metal alloy layers.

42. A vehicle according to claim 41 wherein the metal or metal alloy layers comprise silver and the crosslinked polymeric layer comprises an acrylate polymer.