Prevention of deposits inside polymerisation reactors - by coating with a complex of hydrophilic polymer and inhibitor

摘要

Internal surfaces of polymerisation reactors are coated with an aq. soln. contg. a complex of a hydrophilic polymer with an inhibitor, and the coating rinsed with water before use for polymerisation of =1 monomer. The coating contains 0.05-5 (0.01-1) wt.% of the complex, of which 0.01-2.5 (0.02-1) wt.% i hydrophilic polymer and 0.04-2.5 (0.1-1.0) in inhibitor, the ratio being 1:1-13. Used in all dispersion, emulsion or suspension polymerisation processes, esp. suspension polymerisation of vinyl chloride, opt. together with up to 80 wt.% vinylidene co-monomers. Formation of solid polymer deposits on internal walls, baffle plates, stirrers, etc. is prevented. The coating can be renewed between batches, e.g. by passing in through the spray nozzles, without opening the reactor and allowing escape of vinyl chloride. The polymer prod. is not discoloured by contact with the coating.