Low density microspheres

Patent metadata

Field	Value
Publication number	US-2017335083-A1
Application number	US-201515525656-A
Country	US
Kind code	A1
Filing date	Nov 11, 2015
Priority date	Nov 11, 2014
Publication date	Nov 23, 2017
Grant date	—

Abstract

Low-density thermoplastic expandable microspheres are disclosed. Various low-density structures, in particular, sandwich panels, based on foam prepared from the low-density microspheres, are also disclosed. Process of preparing low-density polymeric microspheres, per se, and the corresponding low-density structures, based on the microsphere foam, are also disclosed.

First claim

1 . A composition-of-matter comprising a powder of thermoplastic expandable polymeric microspheres with a density below 15 kg/m 3 , wherein said microspheres are characterized as having a uniform density, said uniform density being characterized as having at least 80% of said polymeric microspheres with densities that vary within a range of less than 20%.

2 . (canceled)

3 . (canceled)

4 . The composition-of-matter of claim 1 , wherein said thermoplastic polymeric microspheres are characterized as having glass transition temperature of up to about 250° C.

5 . The composition-of-matter of claim 4 , wherein said polymeric microspheres are selected from the group consisting of: polyvinylchloride, polyacrylonitrile, polyvinylidene chloride, polyimide, and any combination and/or derivative, and/or copolymer thereof.

6 . The composition-of-matter of claim 1 , wherein said powder of polymeric microspheres are characterized as having a density of below 1 kg/m 3 .

7 . (canceled)

8 . A composition of matter comprising a foam, said foam comprising the polymeric microspheres, said polymeric microspheres further being expanded and further being fused to each other in at least one portion thereof, wherein said foam is characterized by a density below 15 kg/m 3 , and wherein said density is characterized as being a uniform density, said uniform density being characterized as having at least 90% of said foam with densities that vary within a range of less than 15%.

9 . The composition of matter of claim 8 , wherein said polymeric microspheres are selected from the group consisting of: polyvinylchloride, polyacrylonitrile, polyvinylidene chloride, polyimide, and any combination and/or derivative, and/or copolymer thereof.

10 . (canceled)

11 . The composition-of-matter of claim 8 , wherein said foam is characterized as having a density below 1 kg/m 3 .

12 . The composition-of-matter of claim 8 , further comprising reinforcing fiber filaments, said reinforcing fiber filaments being aramid fiber filaments.

13 . (canceled)

14 . The composition-of-matter of claim 12 , wherein said reinforcing fiber filaments are selected from the group consisting of: Kevlar, Nomex, carbon, glass, Poly(arylenebenzimidazole) (PABI), Poly(phenylenebenzobisoxazole) (PBO), Polybenzimidazole (PBI), and any combination thereof

15 . The composition-of-matter of claim 8 , wherein said polymeric microspheres further comprise a conductive additive, said conductive additive comprising a material selected from the group consisting of: carbon, a conductive polymer, conductive metal particle, a magnetic metal particle, metal alloys, ceramics, a composite material and any mixture thereof, and wherein said material is characterized as having a size of at least one dimension thereof that ranges from about 1 nm to 1000 nm.

16 . (canceled)

17 . The composition-of-matter of claim 15 , wherein said carbon is in the form selected from the group consisting of: pristine carbon nanotubes, functionalized carbon nanotubes, multi walled carbon nanotubes, single walled carbon nanotubes, graphene, fullerene, carbon black, graphite, a carbon fiber, and any combination thereof.

18 . (canceled)

19 . (canceled)

20 . (canceled)

21 . (canceled)

22 . (canceled)

23 . (canceled)

24 . A sandwich panel comprising:
(a) a first skin and a second skin; and (b) a foam comprising the polymeric microspheres, said polymeric microspheres further being expanded and further being fused to each other in at least one portion thereof, wherein: said foam is characterized by a density below 15 kg/m 3 , wherein said density is characterized as being a uniform density, said uniform density being characterized as having at least 90% of said foam with densities that vary within a range of less than 15%; and wherein: said foam is a core being located between a first skin and a second skin.

25 . (canceled)

26 . (canceled)

27 . (canceled)

28 . The sandwich panel of claim 24 , said first skin and said second skin are stitched to a core using yarn beams wherein said yarn is selected from the group consisting of: carbon, glass, aramid, PBI, PABI, PBO, polyimide, polyamide, Poly(ethylene terephthalate) (PET), and any combination thereof.

29 . (canceled)

30 . The sandwich panel of claim 24 , further comprising second foam wherein said second foam
(a) comprises polymeric microspheres, said polymeric microspheres further being expanded and further being fused to each other in at least one portion thereof, (b) is characterized by a density below 15 kg/m 3 , wherein said density is characterized as being a uniform density, said uniform density being characterized as having at least 90% of said foam with densities that vary within a range of less than 15%, and wherein (c) said second foam filling a space surrounding said yarn beams.

31 . The sandwich panel of claim 30 , wherein said second foam is characterized as having a density of at least 30% higher than the density of the foam being located between said first and second skin.

32 . The sandwich panel of claim 24 , wherein said first skin and/or second skin further comprise a fibrous material and/or a resin.

33 . The sandwich panel of claim 32 , wherein said resin is selected from the group consisting of: phenolic, epoxy, polyetheretherketone (PEEK), polyimides, polyamides, bismaleimides, polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polysulphone (PSU) and Polybutylene terephthalate (PBT).

34 . The sandwich panel of claim 32 , wherein said fibrous material is selected from the group consisting of: carbon, glass, aramid, polybenzimidazole (PBI), polyimide, polyamide, PET, and any combination thereof.

35 . The sandwich panel of claim 24 , wherein said first skin and/or said second skin are coated with a material selected from the group consisting of: a metal, a composite, a ceramic, a polymer, and any combination thereof.

36 . The sandwich panel of claim 24 , wherein said foam is selected from the group consisting of: PVC foam, polyurethane (PU) foam, styrene acrylonitrile (SAN) foam, polyethylene, polyimide foam, phenolic foam, and polymethacrylimide (Rohacell) foam.

37 . (canceled)

38 . (canceled)

39 . (canceled)

40 . (canceled)

41 . (canceled)

Assignees

• Technion Res & Dev Foundation

Inventors

• Vaikhanski Lev
• Cohen Yachin

Classifications

• B32B3/26

  characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids {(foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205); characterised by an apertured layer} · CPC title

• B32B2255/10

  on synthetic resin layer or on natural or synthetic rubber layer · CPC title

• B32B2307/202

  Conductive · CPC title

• B32B7/08

  by mechanical means · CPC title

• B29K2105/124

  Nanofibers · CPC title