| 摘要 |
<p>1415756 Chloroprene polymers and blends thereof E I DU PONT DE NEMOURS & CO 16 Feb 1973 [18 Feb 1972] 7798/73 Heading C3P Chloroprene polymers are produced by otherwise conventional aqueous emulsion technique in the presence of an organic sulphur-containing chain-transfer agent and in the additional presence of at least 0À1 wt. per cent (based on monomer) of a benzothiazole sulphenamide of formula wherein R and R<SP>1</SP> are each alkyl, cycloalkyl or aralkyl radicals, any of which may contain substituents which do not detrimentally affect polymerization, and one of them can be hydrogen, or together with the nitrogen atom they form a saturated ring. Suitable chain transfer agents are mercaptans and dialkyl xanthogen disulphides, and the preferred sulphenamide is 2-(morpholinothio) benzothiazole. Examples describe production of polychloroprene. In Example 3, gel and sol polychloroprenes are prepared separately and then mixed, the gel polymer containing 3% ethylene glycol dimethacrylate.</p> |
