Abstract: For the preparation of thermoplastic materials based on (a) homopolymers or copolymers of vinyl chloride and (b) polyacrylates having a glass transition temperature of less than -20.degree. C., firstly the acrylate is polymerized in aqueous emulsion in the presence of crosslinking compounds copolymerizable with the acrylates and having at least two nonconjugated double bonds. Secondly, the vinyl chloride or vinyl chloride with up to 20% by weight of copolymerizable monomers is heated with an initiator, a suspension agent system and optionally additives in an aqueous suspension to a temperature of about .gtoreq.30.degree. C. The polyacrylate is subsequently added and polymerization carried out at temperatures of about >30.degree. C. to the desired conversion. The resulting polymers exhibit improved particle size distribution, good reproducibility of the bulk density and in particular caked deposits on the wall are dramatically reduced during polymerization.