Vinylchlorid-Butadien-Harmassen und Verfahren zu deren Herstellung

摘要

A polymer composition comprises a major proportion of a vinyl chloride polymer containing at least 70% by weight of vinyl chloride and a minor proportion of a graft polymer obtained by polymerizing 80-30 parts by weight of monomers in the presence in aqueous suspension of 20-70 parts of a butadiene polymer containing at least 50% by weight of butadiene and at least 80% having a particle size below 0.1 micron in aqueous suspension using as catalyst 0.5-10 parts of a formaldehyde sulphoxylic salt and 0.01-3 parts of a peroxide, the monomers comprising 5-90% of vinyl or vinylidene aromatic monomer, 5-90% of methyl methacrylate and 5-60% of acrylonitrile. The vinyl chloride is preferably copolymerized with vinyl acetate and the butadiene with styrene, but other comonomers are mentioned; styrene is the preferred aromatic monomer and cumene hydroperoxide the preferred peroxide. Reactants may be added incrementally in forming the graft polymer. In one example, there is also added to the composition, butyl zinc mercaptide and butyl stearate.