REDISPERSIBLE EMULSION POWDER AND PROCESS FOR PRODUCING THE SAME

摘要

Disclosed herein is re-dispersible emulsion powder that can conveniently be used for admixtures to pre-mixed cement compound, powdered paints or adhesive agents, and the like. The re-dispersible emulsion powder according to the present invention is excellent in miscibility with inorganic fillers or polyvalent inorganic salts that are used for engineering works or construction materials, in re-dispersibility and in working properties, and suitable as an admixture for ultra rapid hardening cement. The re-dispersible emulsion powder according to the present invention comprises vinyl copolymer particles containing anion-modified polyvinyl alcohol adsorbed by their surfaces. In a preferred embodiment of the present invention, the re-dispersible emulsion powder is obtained by emulsion-polymerizing a vinyl monomer composition in an aqueous medium in the presence of anion-modified polyvinyl alcohol, and subjecting the resulting aqueous emulsion to drying. Further, in another preferred embodiment of the present invention, the anion-modified polyvinyl alcohol is selected from sulfonic acid-modified polyvinyl alcohol, carboxylic acid-modified polyvinyl alcohol, and mixtures thereof.