Patent ID: 7481525
Filing Date: 2009-01-27
Classification: C09D

Abstract:
1. An ink-jet water-based ink principally comprising a water-insoluble coloring material, a water-soluble organic solvent, an auxiliary component and water, wherein at least polyoxyethylene castor oil or polyoxyethylene hardened castor oil is contained as the auxiliary component, wherein the water-insoluble coloring material is a pigment, and the pigment is dispersed by a polymer dispersant, wherein the polymer dispersant is a polymeric compound composed of at least a monomer having an anionic hydrophilic group, a monomer having an oxyethylene group, and a monomer having a hydrophobic group, and wherein the ratio (A)/(B) of the number (A) of oxyethylene units in the polyoxyethylene castor oil or polyoxyethylene hardened castor oil to the number (B) of oxyethylene units in the polymer dispersant falls within a range of from 0.1 to 5, (A) and (B) being average numbers per molecule.