Method of production of vinylidene fluoride.

摘要

Mfr. of vinyldene fluoride (I) comprises the stages of (a) continuously feeding gaseous HF and gaseous vinylidene chloride (VDC) into a first reactor maintained at a temp. of 22 - 300 deg.C. and contg. a Lewis acid catalyst, to give a prod. stream of fluorination prods. contg. 1-chloro-1,1-difluoroethane (142b), 1,1-dichloro-1-fluoroethane (141b), 1,1,1-trifluoroethane (143a) and HCl, (b) continuously feeding the prod. stream from (a) into a second reactor maintained at 200-700 deg.C. and (c) continuously withdrawing (I) from the second reactor. The catalyst in step (a) is pref. of SnF4 on an active carbon support. The reaction prods. from stage (a) pref. have a residence time in the second reactor of 1-30 sec.. An O2-contg. gas in an amt. of 4-7 mole % or chlorine gas in an amt. of 0.1-4 mole % based on the amt. of vinylidene chloride introduced may be fed into the second reactor to increase the yield of (I). USE/ADVANTAGE - The copyrolysis of the fluorination prods. from the first stage in the prsence of HCl exhibits good selectivity to the prodn. of vinylidene fluoride.