Particulate polymers as filter aids
AssigneeBASF SE
InventorsMarcos Gomez, Tilman C. Rock, Helmut Meffert, Axel Sanner
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Abstract
The use is described of particulate, water-insoluble and scarcely swellable polymers of ethylenically unsaturated monomers, which polymers contain, copolymerized, at least 20% by weight, based on the total weight of the monomers, of at least one α,β-monoethylenically unsaturated monocarboxylic acid having from 3 to 6 carbons as filter aid for filtering aqueous liquids. Subject-matter of the invention are also water-insoluble, scarcely swellable polymers (popcorn polymers) that contain, copolymerized, α,β-monoethylenically unsaturated carboxylic acids and styrene or styrene derivatives, and also a process for their preparation.
Claims15
A method for filtering aqueous liquids, which comprises carrying out the filtration of the aqueous liquid in the presence of a filter aid, wherein the filter aid comprises at least one particulate, water-insoluble and scarcely swellable polymer of ethylenically unsaturated monomers, which contains, copolymerized, at least 20% by weight, based on the total weight of the monomers, of at least one α,β-monoethylenically unsaturated monocarboxylic acid having from 3 to 6 carbons.
A water-insoluble, scarcely swellable polymer containing, copolymerized:
- a) from 20 to 98.9% by weight of at least one α,β-monoethylenically unsaturated monocarboxylic acid having from 3 to 6 carbons as monomer a),
- b) from 1 to 79.9% by weight of styrene and/or at least one monounsaturated styrene derivative as monomber b),
- c) from 0.1 to 10% by weight of at least one monomer c) having at least 2 nonconjugated, ethylenically unsaturated double bonds, with or without
- d) from 0 to 40% by weight of one or more monomers d) different from the monomers a) to c),
- with the percentages by weight of the individual components a) to d) totaling 100%.
Dependencies are inferred from the claim text.