Chloroprene prepn. from (3,4)-dichloro-butene-(1) - by dehydrochlorination with alkali in presence of thio-diphenylamine and (2,6)-di-tert. butyl-(para)-cresol

摘要

The process comprises dehydrochlorinating 3,4-dichlorobutene-1 (I) with alkali in the presence of thiodiphenylamine (II) and 2,6-di-tert-butyl-p-cresol (II). Effective amt. of (II) is 0.01-1 wt. % pref. 0.05-0.5 wt. % to (I). Amt. of (III) is pref. 0.01-1 wt. %, esp. pref. 0.05-0.5 wt. % to (I). Pref. the stabilisers are added to (I) beforehand. Used amt. of alkali is eqiv. to that of (I). When (II) and (III) are present in the reaction mixt. polymer formation is prevented effectively and as a result, operation becomes extremely stable and can be continued for a long periods.