Abstract: The invention concerns well dispersible powders on the basis of carboxylated copolymers containing butadiene made of styrene and/or acrylonitrile, whose films taken from redispersion show good tensile strength. According to the invention, the latices are sprayed with mixtures of spraying aids consisting of 1 to 15 weight % of a salt of the alkylated di-phenyl-ether-di-sulphonic acid, caseinate and/or N-alkyl sulphosuccinamide and/or with 1 to 20 weight % of a di- or tetra sodium or potassium salt of an addition product from N-alkyl sulphosuccinamates with maleic acid mixed together with polyvinyl alcohol. The dispersions can be used especially in the construction industry and they offer an alternative to copolymers on the basis of polyvinyl acetates and acrylates.