METHOD FOR PRODUCING POLYMER POWDERS THAT CAN BE EASILY REDISPERSED IN WATER

摘要

The present invention relates to a process for the preparation of a readily water-redispersible polymer powder by spray drying of an aqueous polymer B dispersion, wherein the spray drying of the aqueous polymer B dispersion is effected in the presence of a polymer A, wherein polymer A has a glass transition temperature≥60°C, a weight average molecular weight Mw≥1000 and≤25000 g/mol, a polydispersity index≤5and is composed of≥5 and≤50 wt% of at least oneα,β-monoethylenically unsaturated mono- or dicarboxylic acid and/or anhydride (monomer A1), and≥50 and≤95 wt% of at least one other ethylenically unsaturated compound which is copolymerizable with the monomers A1 (monomer A2), in polymerized form, wherein the monomer amounts A1 and A2 sum up to 100 wt%.