AQUEOUS POLYURETHANE RESIN COMPOSITION FOR FORMING EPIDERMAL LAYER AND LEATHER-LIKE LAMINATE USING IT

PROBLEM TO BE SOLVED: To provide an aqueous polyurethane resin composition for epidermal layer formation, which contains an organic solvent as little as possible or does not contain it absolutely, exhibits good film formation property, and can form an epidermal layer excellent in abrasion resistance and flex resistance. SOLUTION: The aqueous polyurethane resin composition for epidermal layer formation is obtained by reacting a polyisocyanate (A) with a polyfunctional compound (B) containing a polyester polyol (B1) having carboxyl groups and another polyol (B2) and/or a chain extender (B3) so as to satisfy conditions represented by the following expression (1), then subjecting the resultant isocyanate-terminated prepolymer neutralization product to a chain elongation reaction by using a polyamine (C) having at least two amino groups and/or imino groups and water (D) so as to satisfy conditions represented by the following expressions (2) and (3), and dispersing the resultant reaction product in water. The expressions are: 100/80≤ a/b≤100/40 (1), 100/98≤a/(b+c)≤100/80 (2), and 100/105≤a/(b+c+2d)≤100/95 (3) [in the expressions (1)-(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 amino and/or imino groups (NH) contained in the polyamine (C); and d represents the number of moles of water (D)]. COPYRIGHT: (C)2009,JPO&INPIT