ACRYLIC REDISPERSIBLE POLYMER POWDER FOR NON-CEMENTITIOUS EXTERIOR FINISHING COMPOSITIONS

摘要

The present invention provides a water redispersible polymer powder (RDP) for use in the preparation of non-cementitious exterior finishing compositions such as textured paint formulations. Also provided are non-cementitious exterior finishing compositions comprising such RDPs and a method of coating a surface with such a finishing composition. When the RDP of the invention is incorporated into an exterior finishing composition such as a topcoat formulation of an external insulation finishing system (EIFS), the resultant composition provides improved dirt pickup resistance without a loss in wet abrasion resistance over conventional textured paint formulations comprising acrylic latex powders and, preferably, acrylic latexes.

主权项

1. A water redispersible polymer powder (RDP) comprising a carboxyl group-containing multi-stage acrylic copolymer having:
(a) an alkali-soluble resin outer stage and one or more inner stage(s); (b) a nucleating agent having a boiling point of 150° C. to 500° C. and a water solubility of 3.5 or less; and (c) a colloidal stabilizer,wherein, when dispersed in water, said one or more inner stage comprises an acrylic (co)polymer having a glass transition temperature (Tg), calculated using the Fox equation, of from −40 to 50° C., and wherein the weight ratio of said alkali-soluble resin outer stage to said one or more inner stage(s) is from 1:19 to 2:3.