Vinyl halide polymer of enhanced plasticizer uptake
AssigneeOccidental Chemical Corporation
InventorWilliam L. Schall
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Abstract
Vinyl halide polymer is prepared by bulk liquid phase polymerization of vinyl halide monomer in the presence of a minor proportion, based on the weight of the polymerization reaction mass, of isobutane diluent followed by application of reduced pressure to remove diluent and unreacted monomer from the polymer. The product exhibits improved porosity and molten color stability compared to vinyl halide polymers prepared in bulk in the presence of conventional alkane hydrocarbon diluents.
Claims16
A process for preparing a vinyl chloride polymer which comprises (a) polymerizing a reaction charge in bulk liquid phase in the presence of a polymerization initiator and an inert diluent consisting essentially of isobutane in an amount from about 0.1 to less than 50 weight percent of the reaction charge, said charge comprising vinyl chloride as the sole polymerizable monomer and (b) reducing the pressure on the resultant polymerized reaction charge to separate polymer product from diluent and unreacted monomer.
Dependencies are inferred from the claim text.