PROCESS FOR GAS PHASE POLYMERIZATION OF VINYL CHLORIDE

摘要

(Co)polymerisation of vinyl chloride comprises maintaining the wt.% to 350-550% by adjusting the supply amt. of a seed polymer after the wt.% exceeds 350% initially after starting the polymerisation, when effecting the vapour phase polymerisation of vinyl chloride monomer or vinyl chloride monomer and a monomer copolymerisable with vinyl chloride monomer. The seed polymer is e.g. homopolymer or copolymer of vinyl chloride powdered in the bulk polymerisation, slurry obtd. by adding vinyl chloride monomer, slurry contg. homopolymer or copolymer of vinyl chloride obtd. by the bulk polymerisation. The concn. of the seed polymer is 7-12 wt.%. The slurry is supplied through turning flow type nozzle having 1.5 mm of inlet dia. and 2.0 mm of outlet dia. The satn. vapour pressure ratio of the monomer at the polymerisation pressure/polymerisation temp. is 0.65-0.85.