(EP3287189) 1. A method for producing carbon nanotube pellets comprising the steps of: mixing carbon nanotubes and a solvent to prepare a carbon nanotube paste; and extruding the carbon nanotube paste into pellets, wherein the extrusion is repeated twice or more. 2. The method for producing carbon nanotube pellets according to claim 1, wherein a particle size of the carbon nanotubes contained in the pellet is decreased in proportion to the number of times of extrusion. 3. The method for producing carbon nanotube pellets according to claim 2, wherein a decreasing ratio of D90 of the carbon nanotubes according the number of times of extrusion satisfies the following Expression 2: −167.3x+650≤y≤-167.3x+670 wherein x is the number of times of extrusion of the carbon nanotubes, and y is D90 (µm) of the carbon nanotubes. 4. The method for producing carbon nanotube pellets according to claim 1, wherein the method comprises the steps of: premixing the carbon nanotubes and the solvent; mixing the premixed solution of carbon nanotubes in a screw mixer; and transferring the mixed solution of carbon nanotubes from the screw mixer to an extruder and extruding the mixture into pellets. 5. The method for producing carbon nanotube pellets according to claim 4, wherein the method further comprises the steps of: mixing carbon nanotubes and a solvent to prepare a first paste (kneading); adding additional predetermined solvent to the first paste to prepare a second paste (paste); and adding a solvent to the second paste to prepare a premixed solution (dilution). 6. The method for producing carbon nanotube pellets according to claim 5, wherein the stirring time in the first step (kneading) and the second step (paste) is 2 hours or less, respectively. 7. The method for producing carbon nanotube pellets according to claim 5, wherein an average particle size of the carbon nanotubes after the first step (kneading) is 20 µm or less. 8. The method for producing carbon nanotube pellets according to claim 4, wherein D90 of the carbon nanotubes contained in the carbon nanotube pellets produced by the method is 50 µm or less. 9. The method for producing carbon nanotube pellets according to claim 1, wherein the solvent is at least one selected from the group consisting of water, alcohols, Cellosolve, ketones, amides, esters, ethers, aromatic hydrocarbons such as benzene or toluene, and aliphatic hydrocarbons such as hexane or heptane. 10. Carbon nanotube pellets produced by the method of any one of claims 1 to 9. 11. Carbon nanotube pellets according to claim 10, wherein the pellets has a diameter of 3 mm to 20 mm and a length of 10 mm to 200 mm. 12. Carbon nanotube pellets according to claim 10, wherein a compression ratio of the carbon nanotubes contained in the pellets satisfies by the following Expression 1. CNT compression ratio %=[apparent density of CNT pellet aftercompression]/apparent density of CNT before compression.
最新评论
暂无评论。