BINDER FOR PRINTING INK AND PRINTING INK USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a binder for a printing ink that has good re-solubility in a solvent even if toluene is not used as a solvent, has good solubility in an alcohol solvent even if polyethyleneimine is used as a raw material, and imparts excellent adhesiveness to a variety of plastic films.SOLUTION: The binder for a printing ink comprises (U) a polyurethane resin produced by reacting (P) an urethane prepolymer having an isocyanate group produced by reacting (A) an active hydrogen component and (B) an organic polyisocyanate component with (C) an alkylene oxide adduct of polyethyleneimine. The isocyanate group content in the urethane prepolymer having an isocyanate group (P) is 0.05-1.0 wt% and the total value of a primary amine value and a secondary amine value of the alkylene oxide adduct of polyethyleneimine (C) is 50-230 mgKOH/g.