Patent ID: 10233343

Abstract:
An aqueous ink for use in an ink jet recording method in which ink is thermally ejected from a recording head to record an image on a recording medium. The aqueous ink includes zirconium oxide; a pigment; a resin dispersant for the pigment; and a first and a second urethane resin. The content (ppm) of the zirconium oxide in terms of zirconium is 0.5-20.0 ppm based on the total mass of the ink. The pigment is at least one of phthalocyanine, quinacridone, diketopyrrolopyrrole, dioxazine, perinone, perylene and anthraquinone pigments. Each of the first and second urethane resins has a unit derived from a polyether polyol. The ratio of the weight-average molecular weight Mw1 of the first urethane resin to the weight-average molecular weight Mw2 of the second urethane resin is 0.20-0.80 times. The second urethane resin has a weight-average molecular weight Mw2 of 20,000-70,000.