AQUEOUS POLYURETHANE DISPERSION WITH IMPROVED STORAGE STABILITY

PROBLEM TO BE SOLVED: To provide polyurethane dispersions containing no solvent or NMP, being manufactured without using hydrazine, and having storage stability for 6 weeks or more at a temperature of 40°C. SOLUTION: The hydrazine-noncontaining aqueous polyurethane dispersions contain: (a) a polyisocyanate; (b) a polyol having Mnfrom 500 to 6,000; (c) a polyol having Mnfrom 62 to 500; (d) a compound containing an ionic group or an ionic group-forming group; (e) a polyamine having Mnless than 500; and optionally, (f) a monoalcohol having Mnfrom 32 to 145; and (g) a monoamine having Mnless than 147. In the hydrazine-noncontaining aqueous polyurethane dispersion, at least one of (f) and (g) is used. The hydrazine-noncontaining aqueous polyurethane dispersion has a ratio of, based on the resin of the polyurethane dispersions, of 0.4% by mass to 1.26% by mass of (f) and/or (g), not less than 5.5% by mass to 22% by mass of (c), and 55% by mass to 85% by mass of hard segments of the polyurethane dispersion. COPYRIGHT: (C)2008,JPO&INPIT