National Starch and Chemical Investment Holding Corporation

Antonios Tontisakis

Andrew J Kielbania, Jr

Pravin K Kukkala

Sharon P Lee

Michael T Sarkis

Andrew P Full

Joseph G Kleiner

The invention relates to methods of preparing aqueous polymeric dispersions which contain a water-dispersible polyurethane, a polymer prepared from an ethylenically unsaturated monomer and at least one additional polymer which is capable of enhancing certain properties of products which utilize the aqueous dispersions of the present invention, wherein the ethylenically unsaturated monomer is polymerized in the presence of the water-dispersible polyurethane dispersion and the additional polymer and in the absence of a surfactant and an organic solvent, to aqueous compositions containing the aqueous polymeric dispersions and to articles of manufacture prepared from the aqueous compositions containing the aqueous polymeric dispersions.

Modified aqueous polyurethane dispersions and methods for making same

A process for preparing aqueous dispersions of polyurethanes comprises dispersing polyurethane prepolymer containing unreacted --NCO functionality in water with moderate agitation at a temperature at or below 65.degree. C., preferably at or below 38.degree. C., and more preferably within the range 38.degree.-25.degree. C.; simultaneously reducing the agitation to a mild rate and maintaining the temperature within the range 38.degree.-85.degree. C., preferably, 60.degree.-65.degree. C., until the reaction of --NCO with water levels off; adding an effective amount of a quenching agent to react with sufficient --NCO functionality to reduce the number of available --NCO groups that can react with water so that the evolution of CO.sub.2 is reduced or eliminated during storage of the polyurethane dispersion; and at any of the previous sequential steps adding an effective amount of a deaerating agent to reduce or eliminate CO.sub.2 foaming or to liberate any dissolved CO.sub.2 gas.

Process for making aqueous polyurethane dispersions

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Englewood Cliffs, NJ, United States of America

Antonios Tontisakis