The present invention relates to a process for preparing vinyl dispersion resins by conducting the polymerization reaction of the vinyl monomer or monomers in an aqueous alkaline medium, using an oil-soluble polymerization initiator, at temperatures preferably below about 48°C, in the presence of an emulsifier system comprising the ammonium salt of a high fatty acid containing from 8 to 20 carbon atoms, at least one long straight chain alcohol containing from 14 to 24 carbon atoms, and a sulfate or sulfonate type soap of C12 to C20 alkyl or aryl hydrocarbons, wherein the ratio of alcohol to emulsifier is equal to or greater than 1.0 and wherein the reaction ingredients are thoroughly mixed, and preferably homogenized, prior to polymerization. The process produces paste reins having improved plastisol foam properties, especially when sodium metabisulfite is added to the polymer recipe or the polymer slurry prior to spray drying. Further, polymer buildup in the reactor is substantially reduced and multiple polymerizations can be run in the reactor without opening the same.
本发明涉及一种制备
乙烯基分散
树脂的工艺,其方法是在
水性碱性介质中,使用油溶性聚合
引发剂,在温度最好低于约48℃的条件下,进行
乙烯基单体或多种单体的聚合反应、在由含 8 至 20 个碳原子的高
脂肪酸铵盐、至少一种含 14 至 24 个碳原子的长直链醇和 C12 至 C20 烷基或芳基烃的
硫酸盐或
磺酸盐型皂组成的
乳化剂体系存在下,其中醇与
乳化剂的比例等于或大于 1。0 ,其中反应成分在聚合之前要充分混合,最好是均质化。尤其是在喷雾干燥前将焦
亚硫酸钠添加到聚合物配方或聚合物浆料中时,该工艺生产的糊状缰绳具有更好的塑料溶胶泡沫特性。此外,反应器中的聚合物积聚量大大减少,并且可以在不打开反应器的情况下进行多次聚合。