Patent ID: 10266714

Abstract:
An aqueous ink used in an ink jet recording method that uses thermal energy to eject an ink from a recording head includes a copper phthalocyanine pigment and a urethane resin. The urethane resin has a unit derived from a polyisocyanate, a unit derived from a polyether polyol having no acid group, a unit derived from a polyol having an acid group and a unit derived from a polyamine; in the urethane resin, the proportion of the urethane bond relative to the total amount of the urethane bond and the urea bond derived from the polyamine is 90.0% by mole or more to 99.0% by mole or less; and the urethane resin has a weight-average molecular weight of 20,000 or less and an acid value of 50 mg KOH/g or more to 110 mg KOH/g or less.