| abstract |
(57) [Problem] To provide an aqueous coating agent excellent in water resistance, solvent resistance, adhesion to a substrate, etc., and having surface lubrication and blocking resistance. SOLUTION: In an aqueous medium, a polyurethane prepolymer having an isocyanate group in a molecule includes (a) Obtained by reacting a vinyl alcohol polymer having at least one functional group selected from an amino group, a primary hydroxyl group and an acetoacetyl group in the molecule, and (b) a low molecular compound having an amino group or a hydroxyl group in the molecule. An aqueous coating agent comprising a polyurethane emulsion. |