Continuous dosing of very fast initiators during polymerization reactions
AssigneeAkzo Nobel N.V.
InventorsAndreas Petrus Van Swieten, Hans Westmijze, Jacobus Schut
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Abstract
The invention pertains to a process wherein peroxides are dosed to a polymerization mixture, with essentially all of the organic peroxide that is used in the polymerization process having a half-life from 0.05 hour to 1.0 hour at the polymerization temperature. The dosing of such peroxide allows for accurate control of the polymerization rate, and the process will render a polymer with a low residual peroxide level.
Claims6
Vinylchloride based (co)polymer obtained by using one or more organic peroxides, with at least part of the peroxide being dosed to the polymerization mixture at a reaction temperature of from about 35° C. to about 87° C., characterized in that essentially all of the organic peroxide used in the polymerization process has a half-life of from 0.05 hour to 1.0 hour at the polymerization temperature and that said peroxide is dosed, continuously or discontinuously, over a period of 0.17 hours or longer, with the proviso that the polymerization is not the copolymerization of vinyl chloride monomer and propylene using α-cumyl peroxyneodecanoate as the initiator, the vinylchloride based (co)polymer having less than 50 parts by weight of residual peroxide, based on one million parts by weight of the (co)polymer, when measured immediately after polymerization and drying of the (co)polymer for 1 hour at 60° C.
Dependencies are inferred from the claim text.