Thermoplastische Massen auf der Basis von Polymeren und Copolymeren gegebenenfalls substituierter vinylaromatischer Kohlenwasserstoffe

摘要

1292864 Expandable vinyl chloride compositions UGINE KUHLMANN 30 Dec 1969 [30 Dec 1968] 63308/69 Headings C3C and C3P An expandable composition comprises a thermoplastic vinyl chloride polymer (A) and a resinous thermoplastic styrene-acrylonitrile copolymer (B) of mean viscosimetric molecular weight greater than 3 Î 105 but in any case higher than that of polymer (A) and being compatible with polymer (A), and a blowing agent. In examples, the compositions comprised polyvinyl chloride, a styrene-acrylonitrile copolymer, sodium bicarbonate, barium laurate and cadmium, an organic phosphite, paraffin and ozokerite waxes, sodium silico-aluminate acrylonitrile - styrene - butadiene copolymer, a chlorinated polyolefin and/or calcium stearate. The compositions were extruded to form expanded rods which were drawn. In Example 1, a styrene-acrylonitrile copolymer was made by polymerizing the monomers in an aqueous mixture of tetrapropylbenzene sodium sulphonate, potassium persulphate, sodium bicarbonate and optionally tetrapropylmercaptan.