Electrically conductive polymer adhesives with complex dimensional filters

Patent metadata

Field	Value
Publication number	US-2021230398-A1
Application number	US-202017104283-A
Country	US
Kind code	A1
Filing date	Nov 25, 2020
Priority date	Jan 27, 2020
Publication date	Jul 29, 2021
Grant date	—

Abstract

In one or more embodiments, the present invention is directed to an electrically conductive polymer composition comprising a conductive metal filler material comprising a plurality of metal particles and one or more carbon-based filler material substantially homogenously dispersed throughout a polymer matrix, wherein the aspect ratio of the one or more carbon-based filler material is at least ten times greater than the aspect ratio of the conductive metal filler material comprising a plurality of metal particles. In one or more embodiment, the carbon-based filler material will comprise at least one of carbon nanotubes, multi-walled carbon nanotubes and edge-functionalized graphene.

First claim

What is claimed is:

1 . An electrically conductive polymer composition comprising:
at least one conductive metal filler material comprising a plurality of metal particles having a first aspect ratio; at least one carbon-based filler material having a second aspect ratio; and a polymer matrix; wherein said second aspect ratio is at least ten times greater than said first aspect ratio.

2 . The electrically conductive polymer composition of claim 1 wherein the difference between said first aspect ratio and said second aspect ratio is from about 10 to about 1×10 8 .

3 . The electrically conductive polymer composition of claim 1 wherein the difference between said first aspect ratio and said second aspect ratio is from about 10,000 to about 1×10 8 .

4 . The electrically conductive polymer composition of claim 1 wherein said conductive metal filler material comprises a metal selected from the group consisting of silver, silver flakes, copper, aluminum, silver coated metal, silver coated nickel, silver coated copper, silver coated aluminum, and combinations thereof.

5 . The electrically conductive polymer composition of claim 1 wherein said conductive metal filler material comprises silver flakes.

6 . The electrically conductive polymer composition of claim 1 wherein said first aspect ratio is from about 1 to about 10.

7 . The electrically conductive polymer composition of claim 1 wherein the mean particle size of said conductive metal filler material is from about 1 μm to about 1000 μm.

8 . The electrically conductive polymer composition of claim 1 wherein said carbon-based filler material comprises a carbon-based material selected from the group consisting of carbon nanotubes, multi-walled carbon nanotubes, edge-functionalized graphene, edge-functionalized exfoliated natural graphite, metal coated carbon materials, and combinations thereof.

9 . The electrically conductive polymer composition of claim 1 wherein said carbon-based filler material comprises multi-walled carbon nanotubes.

10 . The electrically conductive polymer composition of claim 1 wherein said carbon-based filler material comprises edge-functionalized exfoliated natural graphite.

11 . The electrically conductive polymer composition of claim 1 wherein said second aspect ratio is from about 1000 to about 10 8 .

12 . The electrically conductive polymer composition of claim 1 wherein said carbon-based filler material is less than 50 nanometers long in at least one dimension.

13 . The electrically conductive polymer composition of claim 1 wherein said polymer matrix comprises a substantially non-conductive polymer selected from the group consisting of polydimethylsiloxane, epoxy, polyacrylates, polymethacrylates, polyurethanes, and combinations thereof.

14 . The electrically conductive polymer composition of claim 1 wherein said polymer matrix comprises polydimethylsiloxane.

15 . The electrically conductive polymer composition of claim 1 wherein the carbon-based filler material has a percolation threshold of from about 0.001% to about 2%.

16 . The electrically conductive polymer composition of claim 15 wherein the carbon-based filler material has a percolation threshold of less than 0.1%.

17 . The electrically conductive polymer composition of claim 1 wherein said conductive metal filler material comprises less than about 16% percent of said electrically conductive polymer by volume.

18 . A method of forming the electrically conductive polymer composition of claim 1 comprising:
A) preparing or obtaining at least one conductive metal filler material comprising a plurality of metal particles having a first aspect ratio;
B) preparing or obtaining at least one carbon-based filler material having a second aspect ratio, wherein said second aspect ratio is at least ten times greater than said first aspect ratio;
C) preparing or obtaining a substantially non-conductive polymer, said substantially non-conductive polymer comprising a polymer base;
D) combining said carbon-based filler material and said polymer base and mixing to distribute said carbon-based filler material throughout said polymer base;
E) adding said conductive metal filler material having to the mixture of step D, wherein said conductive metal filler material comprises less than 15% of the total volume of the mixture;
F) mixing to distribute said carbon-based filler material throughout said polymer base; and
G) curing the mixture to produce the electrically conductive polymer composition of claim 1 .

19 . The method of claim 18 further comprising:
H) adding a quantity of solvent to the mixture of step E to facilitate distribution of the carbon-based filler material throughout said polymer base; and
I) removing said solvent by evaporation.

20 . The method of claim 18 wherein difference between said first aspect ratio and said second aspect ratio is from about 1000 to about 1×10 8 .

21 . The method of claim 18 wherein the step of adding said conductive metal filler material (step E) further comprises adding a curing agent for said polymer base to the mixture of claim D.

22 . The method of claim 18 wherein said conductive metal filler material comprises particles of a conductive metal selected from the group consisting of silver, silver flakes, copper, aluminum, silver coated metal, silver coated nickel, silver coated copper, silver coated aluminum, and combinations thereof.

23 . The method of claim 18 wherein said carbon-based filler material comprises a carbon-based material selected from the group consisting of carbon nanotubes, multi-walled carbon nanotubes, edge-functionalized graphene, edge-functionalized exfoliated natural graphite, metal coated carbon materials, and combinations thereof.

24 . The method of claim 18 wherein said carbon-based filler material comprises at least one of edge-functionalized exfoliated natural graphite and a plurality of multi-walled carbon nanotubes.

25 . The method of claim 18 wherein said substantially non-conductive polymer is selected from the group consisting of polydimethylsiloxane, epoxies, polyacrylates, polymethacrylates, polyurethanes, and combinations thereof.

26 . An electrically conductive polymer comprising:
from about 5 vol % to about 15 vol % of at least one conductive metal filler material comprising silver flakes having a first aspect ratio of from about 1 to about 10 and a particle size of from about 1 μm to about 1000 μm; from about 0.001 wt % to about 8 wt % of one or more carbon-based filler material comprising at least one of multi-walled carbon nanotubes having a second aspect ratio of from about 1000 to about 10 8 and a particle size of from about 1 to about 50 nm and an edge-functionalized exfoliated natural graphite having a third aspect ratio of from about 1000 to about 10 8 and a particle size in a shortest dimension of from about 0.3 nm to about 20 nm; and from about 75 vol % to about 95 vol % of a polymer matrix selected from the group consisting of polydimethylsiloxane, epoxies, polyacrylates, polymethacrylates, polyurethanes, and combinations thereof; wherein said conductive metal filler material comprising silver flakes and said at least one of multi-walled carbon nanotubes or edge-functionalized exfoliated natural graphite are substantially homogeneously distributed throughout said polymer matrix, and wherein said second or t

Assignees

• Zhu Yu
• Vogt Bryan D
• Taubert Clinton J
• Chen Kun
• Univ Akron

Inventors

• Zhu Yu
• Vogt Bryan D
• Taubert Clinton J
• Chen Kun

Classifications

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C08K2003/0806

  Silver · CPC title

• C08K2201/004

  Additives being defined by their length · CPC title

• C08K9/04

  Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)} · CPC title