CATIONIC AQUEOUS POLYURETHANE RESIN AND PREPARATION METHOD THEREOF

摘要

PURPOSE: Provided are a cationic aqueous polyurethane resin which is excellent in adhesion, water dispersion stability and smear fastness, and is free from residual solvent or amine odor, and its preparation method. CONSTITUTION: The method comprises the steps of reacting a polyester polyol and a single molecule diol having an intramolecular tertiary amine with a diisocyanate to prepare a prepolymer; dissolving the prepolymer completely in an organic solvent; neutralizing it with a sulfonic acid derivative or a phosphoric acid derivative to prepare a self-emulsifying prepolymer; adding water to the self-emulsifying prepolymer to emulsify it; extending chain with an amine having intramolecular at least two primary amine groups; and removing the organic solvent, wherein the polyester polyol is a polyol having a molecular weight of 1,000-3,000 and having at least two primary hydroxyl groups at both ends and is prepared by the condensation of a dibasic acid and a divalent alcohol; the content of the single molecule diol is 0.05-2.0 mol to 1 mol of the polyol; and the content of the diisocyanate is 1.1-3.5 mol based on 1 mol of the sum of the polyol land the diol.