Elastomer formulations comprising discrete carbon nanotube fibers

Patent metadata

Field	Value
Publication number	US-9353240-B2
Application number	US-201514924246-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	Dec 14, 2010
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

This present invention relates to the carbon nanotubes as composites with materials such as elastomers, thermosets and thermoplastics. A further feature of this invention relates to the development of a concentrate of carbon nanotubes with an elastomer wherein the concentrate can be further diluted with an elastomer and other polymers and fillers using conventional melt mixing equipment.

First claim

We claim:

1. A composition comprising an elastomer and a plurality of oxidized, discrete carbon nanotubes, wherein the discrete carbon nanotubes have an aspect ratio of 25 or more, are multiwall, and are present in the range of from about 1 to about 30% by weight based on the total weight of the composition.

2. The composition of claim 1 wherein at least 70 percent by weight of the nanotubes are discrete.

3. The composition of claim 1 wherein at least 80 percent by weight of the nanotubes are discrete.

4. The composition of claim 1 in the form of free flowing particles.

5. The composition of claim 1 wherein the oxidized, discrete carbon nanotubes comprise an oxidation species selected from carboxylic acid or derivative carbonyl containing species.

6. The composition of claim 5 wherein the derivative carbonyl species is selected from ketones, quaternary amines, amides, esters, acyl halogens, and monovalent metal salts.

7. The composition of claim 1 wherein the elastomer is a natural or synthetic elastomer.

8. The composition of claim 1 wherein the elastomer is selected from the group consisting of natural rubbers, polyisobutylene, polybutadiene and styrene-butadiene, butyl rubber, polyisoprene, ethylene propylene diene rubbers and hydrogenated and non-hydrogenated nitrile rubbers, polyurethanes, polyethers, silicones, halogen modified elastomers, chloroprene, fluoroelastomers, and combinations thereof.

9. The composition of claim 1 which further comprises at least one filler.

10. The composition of claim 1 which further comprises at least one surfactant or dispersing aid.

11. The composition of claim 1 wherein the discrete carbon nanotubes are functionalized via covalent bonding, ionic bonding, chemisorption, intercalation, surfactant interactions, polymer wrapping, cutting, solvation, or a combination thereof.

12. The composition of claim 1 further comprising carbon black, silica, graphene, oil, or antioxidant.

13. The composition of claim 1 wherein the plurality of oxidized, discrete carbon nanotubes comprise a residual metal concentration of less than about 1000 parts per million as determined by energy dispersive X-ray analysis.

14. The composition of claim 1 in the form of a dispersion.

15. A dispersion comprising:
a plurality of oxidized, discrete carbon nanotubes, wherein the discrete carbon nanotubes have an aspect ratio of 25 or more and are multiwall; and
an elastomer selected from the group consisting of natural rubbers, polyisobutylene, polybutadiene and styrene-butadiene, butyl rubber, polyisoprene, ethylene propylene diene rubbers, hydrogenated and non-hydrogenated nitrile rubbers, polyurethanes, polyethers, silicones, halogen modified elastomers, chloroprene, fluoroelastomers, and combinations thereof.

16. The dispersion of claim 15 wherein the UV absorption at 500 nm is above 1.2 absorption units for a concentration of 2.5×10 −5 g CNT/ml.

17. The composition of claim 15 wherein at least 70 percent by weight of the total nanotubes in the dispersion are discrete.

18. The composition of claim 15 which further comprises water.

19. The composition of claim 15 which further comprises at least one surfactant or dispersing aid.

Assignees

• Molecular Rebar Design Llc

Inventors

• Bosnyak Clive P
• Swogger Kurt W

Classifications

• C08K7/24

  inorganic · CPC title

• C08K2201/011

  Nanostructured additives · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• B82Y30/00

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

• C08L9/06

  Copolymers with styrene · CPC title