BINDER FOR INKJET PRINTING INK, INK FOR INKJET PRINTING CONTAINING SAME, AND PRINTED ARTICLE

摘要

The purpose of the present invention is to provide a binder for an inkjet printing ink that can form a printed image with extremely excellent rubfastness and excellent alcohol resistance, without negatively impacting the favorable discharge stability of the ink. The present invention relates to a binder for an inkjet printing ink containing: (A) a polyurethane having a hydroxyl group on a terminus of a molecule with a weight-average molecular weight of 30,000-70,000 obtained by reacting a polyisocyanate and (a2) a polyol containing a specific polyether polyol such that the equivalent ratio between the isocyanate group [X] of the polyisocyanate (a1) and the hydroxyl group [Y] of the polyol (a2) (isocyanate group [X]/hydroxyl group [Y]) is in a range of 0.930-0.995; and (B) an aqueous solvent, the hydroxyl group that exists at the terminus of the (A) polyurethane molecule being a hydroxyl group originating from the polyether polyol.