Abstract: A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.

Abstract: A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.

Abstract: Polymer dispersions comprise at least one copolymer which contains, as polymerized monomers, a) from 25 to 70% by weight of at least one conjugated aliphatic diene, b) from 25 to 70% by weight of at least one vinylaromatic monomer, c) from 2.5 to 15% by weight of at least one monoester of a C2-C10-alkanediol with acrylic acid or methacrylic acid or c′) from 0.1 to 10% by weight of at least one alkylpolyethylene glycol (meth)acrylate of the formula (I) where R1 is hydrogen or methyl, R2 is C1-C4-alkyl and n is an integer from 1 to 100, or c″) from 2 to 15% by weight of a mixture of the monoester c) and the alkylpolyethylene glycol (meth)acrylate c′), d) from 0 to 1.0% by weight of ethylenically unsaturated monomers which have at least one acid group, or salts thereof, e) from 0 to 5.0% by weight of ethylenically unsaturated nitriles and f) from 0 to 1.0% by weight of amides of &agr;,&bgr;-ethylenically unsaturated mono- and dicarboxylic acids.

Abstract: An aqueous polymer dispersion whose polymer, present in disperse distribution, is composed in free-radically polymerized form of from 20 to 65% by weight of at least one vinylaromatic monomer (monomers A), from 30 to 75% by weight of at least one monomer having two conjugated, ethylenically unsaturated double bonds (monomers B), and from 0.5 to 10% by weight of at least one other monomer, C, selected from the group consisting of &agr;,&bgr;-monoethyienically unsaturated mono- and dicarboxylic acids and amide or ester derivatives thereof and whose alkali metal ion content GA, based on the mass of the dispersed polymer, is ≧0.5% by weight, the pH of the aqueous dispersion medium being adjusted to a value below 6.

Abstract: An aqueous polymer dispersion whose polymer, present in disperse distribution, is composed in free-radically polymerized form of

Abstract: The present invention provides a process for preparing polymer powders by evaporating the volatile constituents from aqueous dispersions of film-forming polymers P in the presence of drying assistants T selected from the salts of oligomeric arylsulfonic acid-formaldehyde condensates wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion comprises at least 1.5% by weight, preferably at least 1.7% by weight, based on the polymer in the dispersion, of at least one anionic surface-active compound AO having at least one C6-C32 alkyl group; the polymer powders obtainable by the process; and their use in binding mineral building materials.

Abstract: The present invention provides a process for preparing polymer powders by evaporating the volatile constituents from aqueous dispersions of film-forming polymers P in the presence of drying assistants T selected from the salts of oligomeric arylsulfonic acid-formaldehyde condensates wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion comprises at least 1.5% by weight, preferably at least 1.7% by weight, based on the polymer in the dispersion, of at least one anionic surface-active compound AO having at least one C6-C32 alkyl group; the polymer powders obtainable by the process; and their use in binding mineral building materials.