Method for reducing the quantity of residual monomers in aqueous polymeric dispersions

US6433132B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Claudia Wood · Weinheim, DE
• Roland Baumstark · Neustadt, DE
• Johannes Dobbelaar · Monsheim, DE

Key dates

• Filing date: Aug 17, 2001
• Grant date: Aug 13, 2002
• Expiry date: Aug 17, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F6/006
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for reducing the amount of residual monomer in aqueous polymer dispersions operates by aftertreatment with an initiator system essentially comprisinga) from 0.001 to 5% by weight, based on the total monomer amount used to prepare the polymer dispersion,a1) of an oxidizing agentR1OOH, where R1 is hydrogen or a C1-C8-alkyl or a C6-C12-aryl group, and/ora2) of a compound which in aqueous medium releases hydrogen peroxide, andb) from 0.005 to 5% by weight, based on the total monomer amount used to prepare the polymer dispersion, of a reducing agent prepared fromb1) an aldehydeR2CH═O, where R2 is a C1-C12-alkyl group which may contain functional groups and/or may be olefinically unsaturated, andb2) an inorganic dithionite, andc) catalytic amounts of a polyvalent metal ion which is able to exist in a plurality of valence states.