| 摘要 |
Aqueous slurries of finely divided fillers which are at least partly coated with polymers and which are obtainable by treating aqueous slurries of finely divided fillers with at least one water-soluble amphoteric copolymer which is obtainable by copolymerization of (a) at least one N-vinylcarboxamide of the formula where R<SUP>1 </SUP>and R<SUP>2 </SUP>are H or C<SUB>1</SUB>- to C<SUB>6</SUB>-alkyl, (b) at least one monoethylenically unsaturated carboxylic acid having 3 to 8 carbon atoms in the molecule and/or the alkali metal, alkaline earth metal or ammonium salts thereof and, if required, (c) other monoethylenically unsaturated monomers which are free of nitrile groups and, if required, (d) compounds which have at least two ethylenically unsaturated double bonds in the molecule and subsequent partial or complete elimination of the groups -CO-R<SUP>1 </SUP>from the monomers III incorporated in the form of polymerized units in the copolymer are used as an additive to the paper stock in the production of filler-containing paper, filler-containing cardboard or filler-containing board by draining of the paper stock.
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