Inversion polymerization process for producing vinyl resins using coated

Abstract

This invention relates to a process of producing vinyl polymers by an inversion polymerization technique in the presence of a coating on the internal surfaces of the polymerization reactor. The coating on said surfaces may be a singular layer or a dual layer coating. By inversion polymerization is meant conducting the initial stage of the polymerization reaction in a medium wherein the monomer or monomers being polymerized constitute the continuous phase and in the second or later stage of polymerization, water constitutes the continuous phase. The principal coating, or undercoating when a dual layer coating is employed, comprises a protein, such as egg albumen, and when a top coating is used it comprises a water-soluble suspending agent, such as an alkyl or alkyl hydroxyalkyl cellulose ether. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.C> grouping, and mixtures thereof, in the presence of said coating, polymer buildup on the inner surfaces of the reaction vessel is substantially eliminated. With the present invention, 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.