Method for producing stable aqueous polymer dispersions based on conjugated alphatic dienes and vinyl aromatic compounds

Abstract

The present invention provides a process for preparing a stable aqueous copolymer dispersion by free-radically initiated aqueous emulsion polymerization of a) from 19.9 to 80 parts by weight of conjugated aliphatic dienes [monomers a)], b) from 19.9 to 80 parts by weight of vinylaromatic compounds [monomers b)], c) from 0.1 to 10 parts by weight of ethylenically unsaturated carboxylic acids and/or dicarboxylic acids [monomers c)], d) from 0 to 20 parts by weight of ethylenically unsaturated carbonitriles [monomers d)], and e) from 0 to 20 parts by weight of copolymerizable compounds other than monomers b) [monomers e)], the total amount of ethylenically unsaturated monomers a) to e) being 100 parts by weight, in the presence of water and from 0.1 to 5 parts by weight, based on the total monomer amount, of emulsifiers comprising f) sulfuric monoesters of ethoxylated fatty acid alcohols and/or g) salts of esters and monoesters of alkylpolyoxyethylenesulfosuccinates, from 15 to 85% by weight of the total emulsifiers used being added within the time taken to reach up to 40% of the total conversion of the monomers a) to e), and from 1 to 50% of the carboxylic acid groups deriving from the monomers c) being neutralized by addition of base.

Dependencies are inferred from the claim text.