Patent ID: 7166655

Claim:
A method for producing an ink jet ink, the ink jet ink comprising a colored particulate dispersion formed by dispersing, in a water based medium, colored particulates comprising an oil soluble dye and a block copolymer formed from a hydrophobic segment and a hydrophilic segment; wherein the oil soluble dye is a compound represented by general formula (I): wherein Q represents an atomic group which is needed for the compound expressed by general formula (I) to have absorption in a visible range or in a near infrared range; A represents —NR 4 R 5 or a hydroxy group, and R 4 and R 5 each independently represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group; B 1 represents ═C(R 6 )— or ═N—; B 2 represents —C(R 7 )═ or —N═; R 2 , R 3 , R 6 and R 7 each independently represents a hydrogen atom or a substituent; and R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , and R 6 and R 7 may bind together to form rings; wherein a monomer forming the hydrophobic segment is ester acrylate, ester methacrylate, N-mono-substituted acrylamide, N-di-substituted acrylamide, N-mono-substituted methacrylamide, N-di-substituted methacrylamide, olefin, or vinyl ether; wherein the block copolymer has an ionic group selected from a carboxyl group, a sulfo group, a sulfino group, or a phosphino group, and the ionic group is present in an amount from 0.2 mmol/g or more to 5.0 mmol/g or less; and wherein an average particle diameter of the colored particulates is in a range of 1 to 500 nm; the method comprising forming the colored particulate dispersion by emulsifying and making into particulates an organic solvent phase, which comprises the block copolymer and the oil-soluble dye, by either adding water to the organic solvent phase or adding the organic solvent phase into water.