Patent ID: 7674860

Claim:
Process for preparing film-forming, redispersible polymer powder comprising the steps of: polymerizing an aqueous medium of olefinically unsaturated monomers, the olefinically unsaturated monomers having at least one monomer with cationic functionality and at least one monomer with one or more reactive groups or at least one monomer with cationic functionality and one or more reactive groups, thereby obtaining at least one polymer with cationic functionality and one or more reactive groups, polymerizing at least one comonomer with at least one initiator in an aqueous medium in the presence of the at least one polymer with cationic functionality and one or more reactive groups to form an aqueous polymer dispersion having particles with heterogeneous morphology and at least one polymer phase with a glass transition temperature below +50° C., and drying the aqueous dispersion to obtain the redispersible polymer powder.