WATER BASE INK, METHOD OF INK JET RECORDING, INK CARTRIDGE, RECORDING UNIT, NK JET RECORDING APPARATUS AND METHOD OF IMAGE FORMATION

摘要

A water base ink comprising water, multiple water soluble organic solvents of different types and a water insoluble color material, wherein the multiple water soluble organic solvents comprises a good solvent for the water insoluble color material and a poor solvent for the water insoluble color material, wherein providing that A represents the total amount (mass%) of good solvent in the ink while B represents the total amount (mass%) of poor solvent in the ink, the ratio of A:B is in the range of 10:5 to 10:30, and wherein upon comparison of the respective Ka values, determined in accordance with the Bristow method, of the multiple water soluble organic solvents, the water soluble organic solvent exhibiting the maximum Ka value is a poor solvent. With respect to pigment inks, images of high OD having a satisfactorily large area factor even with a small amount of ink drop can be obtained.