Carbon nanotube dispersion and method for producing the same

Abstract

The present invention relates to a carbon nanotube dispersion liquid containing carbon nanotubes, a dispersant, and a dispersion medium, wherein the dispersant contains a first dispersant and a second dispersant in a weight ratio of 100:10 to 100:90, the first dispersant being a dispersant containing a cyclic amide group, and the second dispersant being a polymeric compound containing both a sulfone group and styrene, and the weight ratio of the carbon nanotubes to the dispersant is 100:50 to 100:500, and the carbon nanotube dispersion liquid has low viscosity and contains small particles.

Claims

1. A carbon nanotube dispersion comprising carbon nanotubes, a dispersant, and a dispersion medium, The dispersant comprises a first dispersant and a second dispersant in a weight ratio of 100:10 to 100:

90. The first dispersant is a dispersant containing a cyclic amide group, and the second dispersant is a polymer compound containing both a sulfone group and styrene. A carbon nanotube dispersion in which the weight ratio of carbon nanotubes to dispersant is 100:50 to 100:

500.

2. The specific surface area (BET) of the carbon nanotube is 800 m². ２ A carbon nanotube dispersion according to claim 1, wherein the amount is 1 / g or more.

3. The carbon nanotube dispersion according to claim 1, wherein the carbon nanotube is a single-walled carbon nanotube.

4. The carbon nanotube dispersion according to claim 1, wherein the carbon nanotube is contained in an amount of 0.1 parts by weight or more and 5 parts by weight or less per 100 parts by weight of the carbon nanotube dispersion.

5. The first dispersant is polyvinylpyrrolidone, poly-N-vinyl-5-methoxazolidon, polyvinylaziridinone, polyvinylazetidinone, polyvinylpiperidone, or polyvinylcaprolactate. The carbon nanotube dispersion according to claim 1, comprising one or more selected from the group consisting of polyvinylcaprolactam, polymethylenepyrrolidone (poly(3-methylene-2-pyrrolidone)), polymethylmethylenepyrrolidone (poly(N-methyl-3-methylene-2-pyrrolidone)), and polyvinylphthalimide (polyvinylphthalimide).

6. The carbon nanotube dispersion according to claim 1, wherein the second dispersant is one or more selected from the group consisting of polystyrene sulfonic acid, a salt of polystyrene sulfonic acid, and a sulfonate styrene-maleic acid copolymer.

7. The carbon nanotube dispersion according to claim 1, wherein the second dispersant is one or more selected from the group consisting of sulfonated polystyrene, sulfonated styrene-maleic acid copolymer, sodium polystyrene sulfonate, polystyrene sulfonic acid, and ammonium polystyrene sulfonate.

8. The carbon nanotube dispersion according to claim 1, wherein the dispersant comprises a first dispersant and a second dispersant in a weight ratio of 100:20 to 100:

80.

9. The carbon nanotube dispersion according to claim 1, wherein the weight ratio of the carbon nanotube to the dispersant is 100:100 to 100:

250.

10. The carbon nanotube dispersion according to claim 1, wherein the dispersion medium is one or more selected from the group consisting of amide-based polar organic solvents, alcohol-based solvents, glycol-based solvents, glycol ether-based solvents, ketone-based solvents, ester-based solvents, and aqueous-based solvents.

11. The carbon nanotube dispersion according to claim 1, wherein the viscosity increase rate is 20% or less when left standing at 25°C for one week.

12. The carbon nanotube dispersion according to claim 1, wherein the carbon nanotube dispersion contains aggregated carbon nanotube particles having an average particle size (D50) of 0.5 μm or more and 5.4 μm or less.

13. The carbon nanotube dispersion according to claim 1, wherein the carbon nanotube dispersion contains aggregated carbon nanotube particles having an average particle size (D90) of 1.5 μm or more and 15.0 μm or less.

14. An electrode slurry composition for lithium secondary batteries comprising a carbon nanotube dispersion and an electrode active material according to any one of claims 1 to 13.

15. A method for producing a carbon nanotube dispersion according to any one of claims 1 to 13, (1) A step of mixing carbon nanotubes, a dispersant, and a dispersion medium to produce a mixture, (2) The step of dispersing the mixture, The dispersant comprises a first dispersant and a second dispersant in a weight ratio of 100:10 to 100:

90. The first dispersant is a dispersant containing a cyclic amide group, and the second dispersant is a polymer compound containing both a sulfone group and styrene. A method for producing a carbon nanotube dispersion, wherein the weight ratio of the carbon nanotube to the dispersant is 100:50 to 100:500.

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