Process for preparing aqueous polymer dispersions
AssigneeWacker Chemie AG
InventorsHans-Peter Weitzel, Reiner Figge
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Abstract
Redispersible polymer powders are prepared by emulsion polymerization of ethylenical, unsaturated monomers in the presence of a protective colloidal stabilizer containing 20 to 95 weight percent of polymerized monomers containing sulfonic acid or sulfonate groups, 5 to 80 weight percent of polymerized monomers containing amide groups or hydroxylalkyl groups, and up to 5 weight percent of polymerized monomers which are hydrophobic, water-insoluble ethylenically unsaturated compounds. The redispersible polymers are suitable for use in construction materials and coatings, and exhibit higher water resistance than similar polymers stabilized with polyvinyl alcohol as a colloidal stabilizer.
Claims9
A process for preparing protective-colloid-stabilized aqueous polymer dispersions of water insoluble polymers suitable for the preparation of water-redispersible polymer powders, by free-radical emulsion polymerization of ethylenically unsaturated monomers, which comprises carrying out the polymerization in the presence of one or more protective colloids comprising
- a) from 20 to 95% by weight of monomer units containing sulfonic acid groups or sulfonate groups,
- b) from 5 to 80% by weight of monomer units containing amide groups or hydroxyalkyl groups, and
- c) from 0 to 5% by weight of water-insoluble ethylenically unsaturated hydrophobic monomer units.
Dependencies are inferred from the claim text.