| 摘要 |
1429627 Separating vinyl halide polymers from latices BP CHEMICALS INTERNATIONAL Ltd 24 July 1973 [16 Aug 1972 (2) 29 March 1973] 38199/72 38200/72 and 15167/73 Heading C3P A vinyl halide paste-forming polymer is produced by adding an alkaryl sulphonate, an alkyl ether sulphate, or sulphosuccinate emulsifier or a mixture thereof to a paste-forming vinyl halide polymer latex after polymerization, and isolating the polymer from the latex in the presence of said emulsifier. Preferred alkaryl sulphonates are alkyl benzene sulphonates in which the alkyl group is C 6-20 , such as octyl-, nonyl-, decyl-, or dodecyl benzene sulphonates. The alkyl ether sulphates may be made by the reaction of an alkanol with ethylene oxide followed by sulphonation; salts of such compounds may have the formula RO(CH 2 CH 2 O) n SO 3 Na where R is alkyl and n is an integer. Particularly preferred such compounds are alkyl ether sulphates having 6-22 carbon atoms per molecule. Preferred sulphosuccinates are esters of sulphosuccinic acid having 2-22 carbon atoms in each alkanol moiety in the molecule. The polymer may be a vinyl chloride homopolymer or copolymer with less than 20 wt. per cent of another copolymerizable monomer. In the examples PVC homopolymer latices are treated with commercially available emulsifiers selected from sodium dodecyl benzene sulphonate, ammonium dodecyl benzene sulphonate, sodium lauryl ether sulphate, sodium dioctyl sulphosuccinate and sodium di-t-decyl sulphosuccinate, and the polymers are separated by spray drying. |
