PURPOSE: To decrease the amount of an organic solvent used or dispense with the solvent, and improve film performance, film appearance and paint work, by dispersing a specified isocyanato group-containing prepolymer in water and chain-extending the prepolymer with a polyamine.
CONSTITUTION: An isocyanato group-containing prepolymer, oil length 5W85%, obtained by reacting (A) a compound having at least one hydroxyl group or amino group, which is selected frm the group consisting of drying oils, semidrying oils and esterified products derived from their fatty acids, if required, together with (B) a polyhydric alcohol, with (C) a diisocyanate compound at an NCO/active hydrogen ratio of 1.1W2 (eq. ratio) is dispersed in water. Next, the prepolymer in this dispersion system is chain-extended with a polyamine at an NCO/amino group ratio of 1W2 (eq. ratio) to obtain the water-dispersible resin of the purpose. It is also possible to enhance the stability of the final aqueous resin dispersion by employing a polybasic acid (D) prior to the above reaction.
ISHIKAWA HIDENORI
TAKAHASHI NOBUO
| JPS51147597A | 1976-12-17 |