JPS588407B

1498467 Emulsion polymerization of vinyl chloride CHEMISCHE WERKE HULS AG 9 May 1975 [14 June 1974] 19594/75 Heading C3P Polyvinyl chloride suitable for use in placicized foamed products is made by continuously emulsion polymerizing vinyl chloride in the presence of a water-soluble initiator and 1À6- 2À8% based on vinyl chloride of an emulsifier system consisting of (a) 70-30% alkyl sulphate ROSO 3 M (where R=C 10-18 alkyl, M=Na or K) together with (b) up to 65% alkyl ether sulphate R(OCH 2 CH 2 ) n OSO 3 M (where n = 1-5) and/or (c) up to 60% of an alkali metal C 10-20 alkyl sulphonate. Components (a), (b) and (c) may be mixtures: (a) and (b) may contain predominantly lauryl components and (c) may contain predominantly C 15 or C 16 components. In examples, sodium acetate may also be present: the initiator is K 2 S 2 O 8 and the conditions 50‹ C., 5 at., 48% solids content. The products are spray dried with air at 160‹ C. and tested by mixing with dioctylphthalate, benzyl butyl phthalate, azodicarboxylic acid amide, Cd/Zn stabilizer and TiO 2 to form a paste which is spread on a release paper and foamed at 200‹ C.