Process for preparing aqueous dispersions of synthetic materials without emulsifying agents stabilised with a protective colloid

摘要

The invention relates to a process for the preparation of emulsifier-free, aqueous polymer dispersions stabilised by protective colloids, based on 50% by weight of styrene and/or (C1- to C8-alkyl) (meth)acrylate, based on the total amount of monomers. The process comprises the semicontinuous, free-radical polymerisation of the monomers by the monomer feed method in the presence of a water-soluble polyvinyl alcohol as protective colloid, where the total amount of polyvinyl alcohol is introduced at the beginning. The dispersions have a very low residual monomer content. They are suitable as binders in emulsion paints and in hydraulically setting mortars.