申请人:MOBIL OIL CORPORATION
公开号:EP0364636A1
公开(公告)日:1990-04-25
A modified catalyst for polymerizing alpha-olefins, for example, ethylene, is prepared by combining a chromium compound-comprising catalyst, supported on a refractory oxide support with at least one catalyst modifier of the formula R Mg R′ where R and R′ are the same or different C₁-C₁₂ hydrocarbyl, alkoxy, alkenoxy or oxygenated aromatic groups. The amount of the modifier is such that the modified catalyst composition has the molar ratio of magnesium to chromium of 0.2 to 1.25. The modified catalyst composition produces resins of relatively high HLMI at relatively low temperatures.
There is also disclosed a process for polymerizing alpha-olefins, at relatively lower temperatures than was heretofore possible, to obtain resins of relatively high HLMI, using the modified catalyst composition. The resulting polymers can be used for the fabrication of blow-molded products, e.g., household and industrial containers.
一种用于聚合α-烯烃(例如乙烯)的改性催化剂的制备方法是将一种含铬化合物的催化剂与至少一种式 R Mg R′的催化剂改性剂相结合,其中 R 和 R′是相同或不同的 C₁-C₁₂烃基、烷氧基、烯氧基或含氧芳香基。改性剂的用量应使改性催化剂组合物中镁与铬的摩尔比为 0.2 至 1.25。改性催化剂组合物能在相对较低的温度下生产出相对较高 HLMI 的树脂。
此外,还公开了一种使用改性催化剂组合物在比以前更低的温度下聚合α-烯烃以获得相对较高 HLMI 树脂的工艺。得到的聚合物可用于制造吹塑产品,如家用和工业容器。