Water-based pigment ink, and ink-jet recording method and instruments using the same

摘要

Disclosed herein is a water-based pigment ink comprising a coloring material composed of self-dispersing carbon black obtained by bonding at least one hydrophilic group directly or through another atomic group to the surface of carbon black, a humectant of the general formula H-(CH2)m-C-((CH2)nOH)3wherein m and n are independently an integer of from 1 to 5, and an aqueous medium composed of water and a water-soluble organic solvent.