| 摘要 |
Aqueous dispersions of polyurethane polymers in ammonium salt form are prepared by reacting diisocyanates with a polyhydroxy, carboxylic acid to form an isocyanate-terminated prepolymer that is united with an unsaturated fatty acid ester polyol to provide carboxylic-containing, water-dispersible polyurethanes having properties exhibited by organic solvent-based, oil-modified polyurethanes. The aqueous dispersions can be formed by neutralization of "oil-modified," carboxylic group-containing, water-dispersible polyurethanes with ammonium salt-forming materials such as ammonia and amines. The aqueous dispersions are especially desirable coating compositions. |
