Stabilized redispersible polymer powder compositions

Abstract

A water redispersible polymer powder may be produced by drying an aqueous mixture of a water insoluble film-forming polymer and a colloidal stabilizer comprising a chelating agent to obtain a water redispersible polymer powder, where the amount of chelating agent is at least 0.1% by weight, preferably at least 1% by weight, most preferably at least 3% by weight, based upon the weight of the water insoluble film-forming polymer. Dispersions or polymer compositions containing a chelating agent as a colloidal stabilizer exhibit an unexpectedly low viscosity which facilitates spray drying and permits use of high solids content dispersions with low pressure spray drying to increase production efficiency. The chelating agents are stable at high pH and so high pH spray dryable compositions containing them as a colloidal stabilizer may sit or be stored for prolonged periods of time prior to spray drying without loss of effectiveness of the colloidal stabilizer.

Dependencies are inferred from the claim text.