Verfahren zur Herstellung von Vinylchlorid-AEthylen-Copolymerisaten

摘要

Vinyl chloride-ethylene copolymers containing 0.5-8% by wt of combined ethylene are obtained by polymerizing in bulk or aqueous dispersion vinyl chloride and 2.5-7 times the theoretical amount of ethylene in a reaction vessel filled to at least 60% of its capacity with a liquid phase at 30-65 DEG C. and 10-60 atmos. and interrupting the polymerization before the pressure falls to 5 atmos. below the starting pressure and conversion is at least 50%. In one embodiment, no ethylene is added or removed, in another ethylene is bled off to prevent a rise in pressure. A peroxide or azo catalyst is used and in the dispersion process a protective colloid is added. The products have a tensile strength of at least 450 kg./cm.2, an elongation of 100-250% and an intrinsic viscosity of 0.75-2 measured in cyclohexanone at 25 DEG C. and are used as moulding compositions.