Water dispersible, low molecular weight polyamide resin particles of uniform sizes, method of preparing same and coatings formed therefrom

摘要

Finely-divided, water dispersible, low molecular weight, linear polyamide resin particles having a unique morphology and of uniform particle sizes are formed by preparing a linear polyamide of a predetermined low molecular weight in the presence of water followed by rapidly quenching the reaction mass with an aqueous medium below the freezing point of the polyamide and continuing the cooling of the mass to a temperature sufficiently low so as to prevent particle growth and structural alteration while regulating the pH of the quenched mass to provide particles of predetermined, uniform size dispersed in the aqueous medium. The particles vary from ultimate flaky sheets or lamellae to loosely packed, randomly oriented, clusters of flaky sheets. Spray dried products may be agglomerates which disintegrate readily in water to the original particles or aggregates depending upon intended uses. The dispersions and dried products are useful in the coating art and the polyamide may be polymerized to high molecular weights after application to a substrate.