| abstract |
An aqueous polyurethane dispersion comprising at least one isocyanate terminated polyurethane prepolymer prepared by reacting in the presence of at least one pyrrolidone selected from the group consisting of N-n-butylpyrrolidone, N-isobutylpyrrolidone, N-sec-butylpyrrolidone and N-tert-butylpyrrolidone, a mixture (M) which comprises: at least one polyisocyanate compound (a), at least one polyol compound (b), having a molecular weight Mw of 200 to 8000 and a hydroxyl functionality of 1.5 to 6, and at least one water dispersible enhancing component having at least one hydrophilic group or potentially hydrophilic group in water. |