Ink jet black ink, ink set, ink jet recording method, ink cartridge, recording unit, and ink jet recording apparatus

摘要

The present invention aims to provide an ink jet black ink which can improve weatherability, optical density and sticking recovery property of nozzles of a recording head. According to the present invention, an ink jet black ink is provided which comprises at least a coloring-material and a water-soluble organic solvent, wherein the coloring material is a compound represented by the following general formula (I) or a salt thereof, and the water-soluble organic solvent is a water-soluble organic solvent having a relative permittivity of from 30.0 or more to less than 70.0 at 20° C. and capable of dissolving the compound represented by the following general formula (I) or a salt thereof, by 1.0 mass % or more at 25° C., and is in a content of 50.0 mass % or more with respect to the total content of all water-soluble organic solvents contained in the ink jet black ink