Patent ID: 8314170

Claim:
In a process for the spray drying of aqueous polymer dispersions of homo- or copolymers of one or more monomers selected from the group consisting of vinyl esters of unbranched or branched alkylcarboxylic acids with 1 to 18 C atoms, acrylate esters and methacrylate esters of branched and unbranched alcohols with 1 to 15 C atoms, dienes, olefins, vinylaromatics and vinyl halides, in which a dispersant is employed, the improvement comprising selecting as at least one dispersant, a dispersant comprising at least one copolymer prepared by polymerizing a polymerizable mixture consisting essentially of: a) 5 to 70 wt. % of one or more monomers selected from the group consisting of ethylenically unsaturated monocarboxylic acids, ethylenically unsaturated carboxamides, ethylenically unsaturated C 4-8 dicarboxylic acids and anhydrides thereof, and (meth)acrylate monoesters of C 2-8 dialcohols; b) 1 to 40 wt. % of one or more monomers selected from the group consisting of ethylenically unsaturated compounds with sulfonate or sulfate functional groups, c) 10 to 80 wt. % of one or more monomers selected from the group consisting of ethylenically unsaturated compounds of homopolyoxyethylene glycols with 1 to 300 oxyethylene units and terminal groups selected from the group consisting of OH-groups and ether groups —OR′ and mixtures thereof, wherein R′ is an alkyl, aryl, alkaryl or aralkyl residue with 1 to 40 C atoms, d) 5 to 80 wt. % of one or more monomers selected from the group consisting of ethylenically unsaturated compounds of polyoxyalkylene glycols consisting of 1 to 300 C 3-4 oxyalkylene units and terminal groups selected from the group consisting of OH-groups and ether groups —OR′ and mixtures thereof, wherein R′ is an alkyl, aryl, alkaryl or aralkyl residue with 1 to 40 C atoms, and, e) optionally, 0.5 to 10 weight percent of one or more hydrophobic comonomers selected from the group consisting of (meth)acrylate esters of C 1-15 alcohols and vinylaromatics, said copolymer having pendant polyoxyalkylene moieties derived from monomers c) and d) the weight percentages based on the total weight of the copolymer, and totaling 100 wt. %.