Aerogel composite with fibrous batting

• US 7,078,359 B2
• Filed: 12/21/2001
• Issued: 07/18/2006
• Est. Priority Date: 12/22/2000
• Status: Expired due to Term

• Current Assignee: Aspen Aerogels, Incorporated
• Original Assignee: Aspen Aerogels, Incorporated
• Inventors: Gould, George L., Begag, Redouane, Stepanian, Christopher J.
• Primary Examiner(s): Ruddock, Ula
• Assistant Examiner(s): CHRISS, JENNIFER A
• Application Number:
  US10/034,296
• Publication Number:
  US 20020094426A1
• Time in Patent Office: 1,670 Days
• Field of Search: 442/347, 442/417, 442/59, 442/172, 442/179, 442/327, 442/349, 428/292.1, 428/312.2, 428/317.9, 428/402, 501/12
• US Class Current: 442/59
• CPC Class Codes: B01J 13/0091 Preparation of aerogels, e.g. xerogels
• CPC Class Codes: B32B 15/02 Layer formed of wires, e.g. mesh
• CPC Class Codes: B32B 15/14 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 15/18 comprising iron or steel B32B15/011, B32B15/012 and B32B15/013 take precedence
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2250/20 All layers being fibrous or filamentary
• CPC Class Codes: B32B 2250/40 Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• CPC Class Codes: B32B 2305/38 Meshes, lattices or nets
• CPC Class Codes: B32B 2307/718 Weight, e.g. weight per square meter
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: C03C 13/00 Fibre or filament compositions manufacture of fibres or filaments C03B37/00
• CPC Class Codes: C04B 14/064 Silica aerogel
• CPC Class Codes: C04B 14/34 Metals , e.g. ferro-silicon
• CPC Class Codes: C04B 14/386 Carbon carbon nanotubes C04B14/026
• CPC Class Codes: C04B 20/006 Microfibres; Nanofibres
• CPC Class Codes: C04B 2111/00258 Electromagnetic wave absorbing or shielding materials
• CPC Class Codes: C04B 2111/00413 Materials having an inhomogeneous concentration of ingredients or irregular properties in different layers
• CPC Class Codes: C04B 2111/503 Elastic materials
• CPC Class Codes: C04B 30/02 containing fibrous materials
• CPC Class Codes: C04B 32/02 with reinforcements contains no documents; reinforcing elements E04C5/00
• CPC Class Codes: D04H 1/413 : containing granules other than absorbent substances
• CPC Class Codes: D04H 13/00 : Other non-woven fabrics
• CPC Class Codes: E04B 1/7662 : comprising fiber blankets or batts
• CPC Class Codes: E04B 1/78 : Heat insulating elements E04B1/7662 takes precedence
• CPC Class Codes: E04B 2001/7687 : Crumble resistant fibrous blankets or panels using adhesives or meltable fibres
• CPC Class Codes: E04B 9/045 : being laminated
• CPC Class Codes: H05K 9/009 : comprising electro-conductive fibres, e.g. metal fibres, carbon fibres, metallised textile fibres, electro-conductive mesh, woven, non-woven mat, fleece, cross-linked
• CPC Class Codes: Y02A 30/24 : Structural elements or technologies for improving thermal insulation
• CPC Class Codes: Y02B 80/10 : Insulation, e.g. vacuum or aerogel insulation
• CPC Class Codes: Y10T 428/24008 : including fastener for attaching to external surface
• CPC Class Codes: Y10T 428/249924 : Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
• CPC Class Codes: Y10T 428/249962 : Void-containing component has a continuous matrix of fibers only [e.g., porous paper, etc.]
• CPC Class Codes: Y10T 428/249964 : Fibers of defined composition
• CPC Class Codes: Y10T 428/249965 : Cellulosic
• CPC Class Codes: Y10T 442/20 : Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
• CPC Class Codes: Y10T 442/2475 : Coating or impregnation is electrical insulation-providing, -improving, or -increasing, or conductivity-reducing
• CPC Class Codes: Y10T 442/2631 : Coating or impregnation provides heat or fire protection
• CPC Class Codes: Y10T 442/2861 : Coated or impregnated synthetic organic fiber fabric
• CPC Class Codes: Y10T 442/2869 : Coated or impregnated regenerated cellulose fiber fabric
• CPC Class Codes: Y10T 442/2902 : Aromatic polyamide fiber fabric
• CPC Class Codes: Y10T 442/291 : Coated or impregnated polyolefin fiber fabric
• CPC Class Codes: Y10T 442/2918 : Polypropylene fiber fabric
• CPC Class Codes: Y10T 442/2926 : Coated or impregnated inorganic fiber fabric
• CPC Class Codes: Y10T 442/2984 : Coated or impregnated carbon or carbonaceous fiber fabric
• CPC Class Codes: Y10T 442/60 : Nonwoven fabric [i.e., nonwoven strand or fiber material]
• CPC Class Codes: Y10T 442/622 : Microfiber is a composite fiber
• CPC Class Codes: Y10T 442/624 : Microfiber is carbon or carbonaceous

Abstract

Aerogel composite materials having a lofty fibrous batting reinforcement preferably in combination with one or both of individual short randomly oriented microfibers and conductive layers exhibit improved performance in one or all of flexibility, drape, durability, resistance to sintering, x-y thermal conductivity, x-y electrical conductivity, RFI-EMI attenuation, and/or burn-through resistance.

Claims

1. A composite article to serve as a flexible, durable, light-weight insulation product, said article comprising a lofty fibrous batting sheet and a continuous aerogel through said batting.

2. The composite article of claim 1, wherein the aerogel is selected from the group consisting of inorganic gel forming materials.

3. The composite article of claim 1, wherein the inorganic gel forming material is selected from the group consisting of zirconia, yttria, hafnia, alumina, titania, ceria, and silica, and any combination thereof.

4. The composite article of claim 1, wherein the organic gel forming material is selected from the group consisting of polyacrylates, polystyrenes, polyacrylonitriles, polyurethanes, polyimides, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehydes, resorcinol formaldehydes, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, and agarose, and combination thereof.

5. The composite article of claim 1, wherein the lofty fibrous batting consists essentially of fibers having a thermal conductivity less than 50 mW/m-K.

6. The composite article of claim 1, wherein the lofty batting has a sufficient quantity of fibers in its z axis to provide loft yet not so many that the insulating properties of the composite arc compromised by the z axis fibers acting as thermal conduits.

7. The composite article of claim 1, further comprising a dopant.

8. The composite article of claim 7, wherein the dopant is selected from the group consisting of carbon black, titania, iron oxides, silicon carbide, molybdenum silicide, manganese oxides, and polydialkylsiloxanes wherein the alkyl groups contain 1 to 4 carbon atoms.

9. The composite article of claim 7, wherein the dopant is present in an amount of about 1 to 20% by weight of the total weight of the composite.

10. The composite article of claim 1, wherein the surface area of the fibers of the batting visible in a cross-section of the composite is less than 8% of the total surface area of that cross section.

11. The composite article of claim 1, wherein the fibers making up the lofty fibrous batting have a diameter of about 0.1 to 100 μ

m and are crimped fibers evenly dispersed throughout the composite.

49. The composite article of claim 1, wherein the batting has a density of between about 0.001 and 0.26 g/cc.

50. The composite article of claim 1, wherein the batting has a density of between 0.04 and 0.1 g/cc.

51. The composite article of claim 1, wherein the batting has a density of about 0.04.

12. A composite article comprising a fibrous batting sheet and a continuous aerogel through said batting, where the batting is sufficiently lofty that the cross-sectional area of the fibers of the batting visible in the cross-section of the composite is less than 10% of the total surface area of that cross section.

13. The composite article of claim 12, wherein the aerogel is selected from the group consisting of inorganic and organic gel forming materials.

14. The composite article of claim 12, wherein the inorganic gel forming material is selected from the group consisting of zirconia, yttria, hafnia, alumina, titania, ceria, and silica, and any combination thereof.

15. The composite article of claim 12, wherein the batting is compressible by a minimum of 50% of its thickness and is sufficiently resilient that after compression for about 5 seconds it returns to at least 70% of its original thickness.

16. The composite article of claim 12, wherein the fibrous batting is sufficiently lofty that it retains at least 50% of its thickness after addition of the gel forming liquid to form said aerogel.

17. The composite article of claim 12, wherein the batting has a density in the range of about 0.1 to 16 lbs/ft³ (0.001–

0.4 g/cc), is compressible by at least 65% of its thickness and is sufficiently resilient that after compression for about 5 seconds it returns to at least 75% of its original thickness.

18. The composite article of claim 12, wherein the batting has a density of about 2.44 to 6.1 lbs/ft³ (0.04 to 0.1 g/cc).

19. An aerogel composite article comprising (i) a fibrous batting sheet and a continuous aerogel through said batting, where the batting causes no substantial degradation of the thermal performance of the composite as compared with an aerogel of the same material and (ii) microfibers having diameters from about 0.1 to 100 μ

m and aspect ratios greater than 5.

20. The composite article of claim 19, wherein the microfibers are comprised of a material having a thermal conductivity below about 200 mW/mK.

21. The composite article of claim 19, wherein the microfibers are comprised of a material that resists sintering more than the lofty fibrous batting.

22. The composite article of claim 19, wherein the microfibers are comprised of a material that reduces the transmission of infrared radiation through the composite more than the lofty fibrous batting.

23. The composite article of claim 19, wherein the microfibers are comprised of a material that attenuates radio frequency waves.

24. The composite article of claim 19, wherein the microfibers are comprised of one or more materials that attenuate electromagnetic waves.

25. The composite article of claim 19, wherein the microfibers are selected from the group consisting of carbon fibers and copper fibers.

26. The composite article of claim 19, wherein at least one of the following properties varies within spatial locations of the composite:

microfiber material;

microfiber size;

microfiber aspect ratio; and

microfiber quantity.

27. The composite article of claim 19, wherein a material having a high thermal conductivity equal to or greater than 1 W/mK is added on the x-y axis of the composite structure in addition to the lofty batting.

28. The composite article of claim 27, wherein the high thermal conductivity material comprises a metal.

29. The composite article of claim 28, wherein the high thermal conductivity material is a metal which is sufficiently malleable to provide conformability to the composite to enable the composite to retain its shape after bending.

30. The composite article of claim 29, wherein the metal is selected from the group consisting of copper and steel.

31. The composite article of claim 27, wherein the high thermal conductivity material is in a porous form selected from the group consisting of mesh, sheet, perforated sheet, foil, and perforated foil.

32. The composite article of claim 27, wherein the composite has an x-y horizontal plane and a z vertical plane and the thermally conductive materials are oriented in the x-y plane of the composite.

33. The composite article of claim 27, wherein the high thermal conductivity material conducts heat away from a localized heat load and emits it to the environment.

34. The composite article of claim 33 further comprising a heat sink, wherein the heat is emitted to the environment by means of the heat sink.

35. The composite article of claim 27, wherein the high thermal conductivity material conducts heat away from a localized heat load to a process which uses the thermal energy directly.

36. The composite article of claim 27 further comprising device which converts the thermal energy to electrical energy, wherein the high thermal conductivity material conducts heal away from a localized heat load and into the device.

37. The composite article of claim 27, wherein the high thermal conductivity material comprises carbon fibers.

38. An aerogel composite article comprising (i) a fibrous batting sheet and a continuous aerogel through said batting, where the batting causes no substantial degradation of the thermal performance of the composite as compared with an aerogel of the same material and (ii) one or more high thermal conductivity materials having a thermal conductivity of equal to or greater than 1 W/mK.

39. The composite article of claim 38, wherein the high thermal conductivity material comprises a metal.

40. The composite article of claim 38, wherein the high thermal conductivity material is a metal which is sufficiently malleable to provide conformability to the composite to enable the composite to retain its shape after bending.

41. The composite article of claim 40, wherein the metal is selected from the group consisting of copper and steel.

42. The composite article of claim 38, wherein the high thermal conductivity material is in a porous form selected from the group consisting of mesh, sheet, perforated sheet, foil, and perforated foil.

43. The composite article of claim 38, wherein the composite has an x-y horizontal plane and a z vertical plane and the high thermal conductivity material is oriented in the x-y plane of the composite.

44. The composite article of claim 38, wherein the high thermal conductivity material conducts heat away from a localized heat load and emits it to the environment.

45. The composite article of claim 44, wherein the heat is emitted to the environment by means of a heat sink.

46. The composite article of claim 38, wherein the high thermal conductivity material conducts heat away from a localized heat load to a process which uses the thermal energy directly.

47. The composite article of claim 38, wherein the high thermal conductivity material conducts heat away from a localized heat load and into a device which converts the thermal energy to electrical energy.

48. The composite article of claim 38, wherein the high thermal conductivity material comprises carbon fibers.