| 摘要 |
Polyvinyl chloride resins and copolymers thereof are produced containing little or no get content, commonly referred to as "fisheyes", even after numerous charges to a reaction vessel without cleaning thereof between charges. A primary dispersant system such as a high hydrolyzed polyvinyl acetate and an optional modified cellulose ether are utilized in association with a low hydrolyzed secondary dispersant, for example, polyvinyl acetate, in the reaction vessel such as a polymerizer containing an aromatic inhibitor polymer build-up compound coated on the internal walls thereof. The resin particles produced tend to have a uniform particle size and a high porosity so that plasticizers can readily be incorporated therein. Since contamination buildup on the reaction vessel walls is reduced or prevented, the amount of gel is reduced and production rate is increased since, as noted above, cleaning of the vessels is not required.
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