| 摘要 |
This invention relates to a process of producing vinyl polymers by an inversion polymerization technique in the presence of a two layer coating on the internal surfaces of the polymerization reactor. By inversion polymerization is meant conducting the initial stage of the polymerization reaction wherein the monomer or monomers being polymerized constitute the continuous phase and in the latter stage of polymerization, water constitutes the continuous phase. The coatings comprise an undercoating of an alkali soluble dye dissolved in an aqueous alkali metal hydroxide solution or an ammonium hydroxide solution. The top coating is comprised of a water soluble suspending agent, such as an alkyl or alkylhydroxy alkyl cellulose ether. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH2=C< grouping and mixtures thereof, in the presence of said coatings, polymer buildup on the inner surfaces of the reaction vessel is substantially eliminated. More importantly, multiple charges or batches of polymer can be made in said internally coated reaction vessel without opening the same between charges, thus preventing the escape of unreacted monomer to the atmosphere.
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