WATER-BASE URETHANE-UREA RESIN DISPERSION AND WATER-BASE PRINTING INK PREPARED THEREFROM

摘要

PURPOSE:To prepare the subject dispersion giving a water-base printing ink excellent in heat resistance and properties in printing a plastic film by using a polyamide as a part of a neutralizing agent used to neutralize COOH groups contained in a carboxylated urethane-urea resin prepd. by a specified method. CONSTITUTION:A mixture of a carboxylated dihydroxy compd. with a hydroxyl- terminated polyol compd. having a mol.wt. of 1,000-6,000 is reacted in an org. solvent with a diisocyanate compd. in an excess molar amt. based on the total amt. of the hydroxyl groups of the mixture, giving a soln. of a urethane prepolymer having terminal NCO groups and internal COOH groups. The soln. is mixed with a tertiary amine to neutralize 80-95% of the COOH groups, and mixed with an aq. soln. of a diamine chain extender to conduct a chain extension reaction, giving a water-base dispersion of a carboxylated urethane-urea resin precursor. Free COOH groups remaining in the precursor are neutralized with a polyamide having an amine value of 100-500 to give the objective dispersion.