High-impact solution polymers

摘要

A process for the continuous preparation of impact-modified styrene-acrylonitrile or styrene-methyl methacrylate polymers by free-radical-initiated graft polymerisation of styrene and acrylonitrile or methyl methacrylate in the presence of polybutadiene or styrene-butadiene block copolymers as the graft base and in the presence of a solvent, where firstly polybutadiene or the styrene-butadiene block copolymer is introduced in dissolved form and is converted into a disperse phase (phase inversion) during the grafting and polymerisation, in an apparatus comprising a reaction chamber with full back-mixing and a downstream tubular reactor and optionally an apparatus for removing residual monomers and solvent, where static mixing elements are present in the region of phase inversion, and the particle size and distribution are adjusted through the flow and/or sheer rates and/or temperature in the region of these mixing elements.