| abstract |
An object of the present invention is to provide a method for selectively removing impurities from a soot-like substance containing C 60 , C 70 and higher fullerenes to produce fullerenes with high purity and high yield. A soot-like substance containing C 60 , C 70 and higher fullerenes is mixed with an extraction solvent containing an aromatic hydrocarbon to obtain an extract, and the extract is subjected to C 60 by liquid chromatography. , it was added a second step of obtaining a separated liquid to separate the C 70 and higher fullerenes in a liquid phase, a poor solvent solubility of C 60 is less than 10 mg / L in the separated liquid, precipitating higher fullerenes A third step of causing the solution of C 60 and C 70 to obtain a solution of C 60 and C 70 and a fourth step of distilling and / or cooling the poor solvent and extraction solvent of C 60 in the solution to precipitate C 60 and C 70. . [Selection diagram] Fig. 1 |