The invention concerns highly dispersible powders based on carboxylated butadiene-containing copolymers of styrene and/or acrylonitrile, the films of these powders drawn from the redispersion displaying high tensile strength. According to the invention, the latices are atomized with mixtures of atomizing aids consisting of between 1 and 15 wt % of a salt of alkylated di-phenyl-ether-di-sulphonic acid, caseinate and/or N-alkylsulphosuccinamide and/or with between 1 and 20 wt % of a di- or tetra-sodium or potassium salt of an addition product of N-alkyl-sulphosuccinamates with maleic acid in a mixture with polyvinylalcohol. The dispersions can predominantly be used in the construction industry and are alternatives to the copolymers based on polyvinylacetates and acrylates.