Patent ID: 7902291

Claim:
A method for manufacturing an aqueous polyurethane resin composition, comprising the steps of: obtaining a neutralized prepolymer having a terminal isocyanate group by reacting a polyisocyanate (A) and a polyfunctional compound (B) containing a polyester polyol (B 1 ) having an acidic group and at least one member selected from the group consisting of other polyols (B 2 ) and chain extenders (B 3 ) so as to satisfy a condition expressed by the following mathematical formula (1); and obtaining an aqueous polyurethane resin composition by subjecting the neutralized prepolymer having a terminal isocyanate group to a chain elongation reaction with the use of a polyamine (C) containing at least two groups selected from the group consisting of an amino group and an imino group and water (D) so as to satisfy conditions expressed by the following formulas (2) and (3) to obtain a elongated product, and then dispersing the elongated product into water: 100/80 ≦a/b≦ 100/40 (1) 100/98 ≦a/ ( b+c )≦100/80 (2) 100/105 ≦a/ ( b+c+ 2 d )≦100/95 (3) wherein in formulas (1) to (3), a represents the number of isocyanate groups (NCO) contained in the polyisocyanate (A), b represents the number of hydroxyl groups (OH) contained in the polyfunctional compound (B), c represents the number of the groups selected from the group consisting of an amino group (NH 2 ) and an imino group (NH) contained in the polyamine (C), and d represents the number of moles of the water (D).