Patent ID: 6190503
Filing Date: 2001-02-20
Classification: C02F,D21C,Y10S

Abstract:
A process for treating waste waters and circulation waters in papermaking, in deinking and in pulp bleaching, comprising retaining insoluble impurities and absorbing water-soluble anionic compounds and compounds comprising phenolic resins and monobasic acids and anions thereof dispersed in water from the wastewaters and circulation waters over a finely divided absorbent, wherein the finely divided absorbent is an insoluble, only slightly swellable polymer which is prepared by copolymerizing(a) N-vinylcarboxamides of the formula ##STR4##wherein R and R.sup.1 are each H or C.sub.1 -C.sub.6 -alkyl, and(c) from 0.1 to 10% by weight, based on the monomer (a) of a compound containing at least two ethylenically unsaturated double bonds as a crosslinking agent, in the absence of oxygen and polymerization initiators to produce popcorn polymers, and eliminating the groups ##STR5##from at least 0.1% of the polymerized N-vinylcarboxamides of the formula I with the formation of vinylamine units of the formula ##STR6##wherein R.sup.1 is H or C.sub.1 -C.sub.6 -alkyl.