Process for sizing paper
AssigneeBayer Aktiengesellschaft
InventorsMichael Muller, Joachim Probst, Heinrich Alberts, Joachim Konig, Heinz Baumgen, Fritz Puchner
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Abstract
The new vinyl polymer dispersions are obtainable by free radical polymerisation of olefinically unsaturated monomers in the presence of a cationic polyamidoamine which has been rendered hydrophobic, and can be used as sizing agents for paper which are distinguished, in particular, by their shear, electrolyte, heat and storage stability.
Claims13
A process for sizing paper which comprises contacting the paper with a vinyl polymer dispersion obtained by emulsion polymerization, initiated by free radicals, of olefinically unsaturated monomers in an aqueous medium, the olefinically unsaturated monomers comprising
- a) 5 to 95% by weight of acrylonitrile, methacrylonitrile, styrene or mixtures thereof and
- b) 5 to 95% by weight of a (meth)acrylic acid ester having 1 to 12 C atoms in the alcohol radical,
- the sum of components a) and b) totalling 100% by weight,
- and the emulsifier in said emulsion polymerization comprising a cationic polyamidoamine which has been rendered hydrophobic, has a content of cationic groups of between 0.01 and 0.3 charge equivalent per 100 g, a content of hydrophobic groups of between 0.5 and 50% by weight and a content of basic nitrogen atoms of between 0 and 3% by weight, in each case based on the cationic polyamidoamine which has been rendered hydrophobic, the polyamidoamine having been obtained by reaction of a basic polyamidoamine (A) with a monocarboxylic acid (B) and at least one of subsequent protonation with an acid (C) and quaternization with a monoepoxide (D).
Dependencies are inferred from the claim text.