To obtain an ink jet recording ink having improved storage stability and improved unevenness of density and fixability by formulating a water- insoluble colorant which in the dispersed state has a specified particle diameter and a specified particle count with a polymeric dispersant having a specified solubility parameter(SP), a water-soluble organic solvent having a specified solubility parameter and water.
This ink contains a water-insoluble colorant comprising particles which in the dispersed state have a number-mean particle diameter of 10-100 nm, a number-mean particle diameter/volume-mean particle diameter ratio of 2.5 or below and a count of 0.5 μm or larger particles of 7.5×104/μl, a polymeric dispersant being a polymer comprising a hydrophobic part and a hydrophilic part and having carboxylic acid (salt) groups in the hydrophilic part and having an SP of 10-13 and an organic solvent having an SP equal to or higher than the SP of the polymeric dispersant +0.5 and comprising at most 5 wt.%, based on the total ink weight, water-soluble organic solvent having an SP equal to or lower than the SP of the polymeric dispersant ±0.5 and 1-30 wt.% water-soluble organic solvent having an SP above +0.5.
YUI TOSHIKI
SUZUKI JUNJI
YAMASHITA KUNICHI
HORINOUCHI KYOKO
HASHIMOTO TAKESHI
