Patent ID: 8669324

Claim:
A method for producing a binder for inkjet printing inks, the binder containing a hydrophilic-group-containing urethane resin (A), an acetylene compound (B), and an aqueous medium (C), the acetylene compound (B) containing an alkylene oxide adduct of an acetylene glycol or an alkylene oxide adduct of an acetylene monoalcohol, the alkylene oxide containing ethylene oxide, the method comprising: step (1) of allowing a polyol (a1) containing a hydrophilic-group-containing polyol (a1-1) to react with a polyisocyanate (a2) in an organic solvent (D) or in the absence of a solvent, and feeding the organic solvent (D) in case the reaction is carried out in the absence of a solvent, to prepare an organic solvent (D) solution [I] of a hydrophilic-group-containing urethane resin (A); step (2) of mixing the organic solvent (D) solution [I] with the acetylene compound (B) and the aqueous medium (C) to prepare a mixture [II]; and step (3) of removing part of the aqueous medium (C) along with removing part or all of the organic solvent (D) contained in the mixture [II], wherein the mass of the aqueous medium (C) to be removed is equal to 50% by mass to 300% by mass of the total mass of the organic solvent (D) contained in the mixture [II].