Patent ID: 6444785
Filing Date: 2002-09-03
Classification: C08F

Abstract:
A process for reducing the residual monomer content in a W/O emulsion comprising crosslinked water-swollen addition polymers dispersed therein, said process comprising aftertreating said W/O emulsion with a redox initiator system comprising,a) from 0.001 to 5% by weight, based on the total monomer amount used to prepare the polymer, a1) of an oxidizing agent: R1OOH, â€ƒwhere R1 is hydrogen, a C1- to C8-alkyl or C6- to C12 aryl group, and/or a2) of a compound which in aqueous medium releases hydrogen peroxide, and b) from 0.005 to 5% by weight, based on the total monomer amount used to prepare the polymer of a reducing agent, b1) which is an &agr;-hydroxy carbonyl compound: â€ƒwhere, independently of each other, R2 is hydrogen or a C1-C12-alkyl group which optionally contains functional groups and/or can be olefinically unsaturated, R3 is hydrogen, OH, a C1-C12-alkyl group which optionally contains functional groups and/or can be olefinically unsaturated, and R2 and R3 can form a ring structure which can include a heteroatom and/or functional groups and/or can be olefinically unsaturated, and/or b2) a compound which in aqueous medium releases an &agr;-hydroxy carbonyl compound, and c) catalytic amounts of a polyvalent metal ion which is able to exist in a plurality of valence states.