A METHOD FOR PREPARING A CARBON NANOTUBE POWDER AND THE CAROBON NANOTUBE POWDER PREPARED USING THE METHOD, A CARBON NANOTUBE PASTE COMPRISING THE CARBON NANOTUBE POWDER, AN EMITTER PREPARED USING THE CARBON NANOTUBE PASTE, AND AN ELECTRON EMISSION DEVICE COMPRISING THE EMITTER

摘要

A method of producing carbon nano-tube powder and paste for electron emission device is provided to obtain high purity nano-tube powder with reduced catalyst metal content used as electron emitter for electron emission device by applying vacuum heating or acid treatment process to remove catalyst metal ingredient from the powder. The method is to conduct any one selected from vacuum heat treatment and acid treatment to reduce content of catalyst metal among the carbon nano-tube powder. In case of the heat treatment, the temperature ranges from 1000 to 1500deg.C. The acid treatment is carried out in acid solution having pH 2 to 5 by using any one selected from hydrochloric acid, nitric acid, sulfuric acid and mixture thereof. The carbon nano-tube powder contains less than 3wt.% of catalyst metal and is used to form carbon nano-tube paste together with vehicle comprising polymer ingredient and organic solvent.