Method for preparing carbon nanotube dispersion

Patent metadata

Field	Value
Publication number	US-11453592-B2
Application number	US-201916631643-A
Country	US
Kind code	B2
Filing date	Jan 21, 2019
Priority date	Jan 29, 2018
Publication date	Sep 27, 2022
Grant date	Sep 27, 2022

Abstract

The present invention relates to a method for preparing a carbon nanotube dispersion, the method including mixing a dispersion solution including a dispersion solvent and a dispersant with carbon nanotubes to prepare carbon nanotube paste, extruding the paste to obtain solid carbon nanotubes, and introducing a second solvent to the solid carbon nanotubes, and homogenizing the carbon nanotubes, wherein the weight ratio of the dispersion solution and the carbon nanotubes is 1:1 to 9:1. According to the present invention, the mixing of a dispersant and carbon nanotubes is increased and the particle size is controlled by a wet method, so that a carbon nanotube dispersion having a viscosity controlled to a low level, excellent resistance properties, and a high concentration, may be provided.

First claim

The invention claimed is:

1. A method for preparing a carbon nanotube dispersion, the method comprising:
mixing a dispersion solution, including a dispersion solvent and a dispersant, with carbon nanotubes to prepare carbon nanotube paste;
extruding the paste to obtain solid carbon nanotubes; and
introducing a second solvent to the solid carbon nanotubes in an amount of 150-300 parts by weight based on 100 parts by weight of the solid carbon nanotubes, and homogenizing the carbon nanotubes, wherein the weight ratio of the dispersion solution to the carbon nanotubes is 1:1 to 5:1.

2. The method of claim 1 , wherein the dispersant is introduced in an amount of 10-50 parts by weight, based on 100 parts by weight of the carbon nanotubes.

3. The method of claim 1 , wherein the extruding is performed with a screw-type extruder, and the extruder comprises:
a supply part from which a material is supplied;
a rotary part including a screw to apply rotational force to the material and having an inner space in which the material is mixed; and
a discharge part including a discharge plate having one or more discharge ports to discharge an extruded material.

4. The method of claim 3 , wherein the screw has a rotational speed of 500-1500 rpm.

5. The method of claim 3 , wherein the discharge plate has an opening ratio of 20-50% and the discharge port has a diameter of 1-5 mm.

6. The method of claim 1 , wherein the dispersion solvent and the second solvent are each independently one or more selected from the group consisting of water, methanol, ethanol, propanol, isopropanol, butanol, N-methyl pyrrolidone (NMP) and N, N-dimethylformamide (DMF).

7. The method of claim 1 , wherein the dispersant is one or more selected from the group consisting of styrene butylene rubber (SBR), carboxymethyl cellulose (CMC), hydrogenated acrylonitrile butadiene rubber (H-NBR), polyvinylpyrrolidone (PVP), and polyvinylbutyral (PVB).

Assignees

• Lg Chemical Ltd

Inventors

• Kang Kyung Yeon
• Lee Seung Yong
• Kim Seok Won
• Kang Hyun Joon

Classifications

• B29C48/022

  characterised by the choice of material · CPC title

• B29K2105/0064

  Latex, emulsion or dispersion · CPC title

• B82Y30/00

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

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01B32/174 Primary

  Derivatisation; Solubilisation; Dispersion in solvents · CPC title