| 摘要 |
<p>A catalyst component for polymerizing ethylene alone or with another alpha-olefin having from 3 to 18 carbon atoms at temperatures greater than about 150.degree.C which catalyst component is the product obtained by treating at least one dehydrated particulate support material, such as silica, having an average particle size from about 0.05 to about 20 microns, preferably 1.0 to 10.0 microns, with (a) at least one dihydrocarbyl magnesium compound wherein the hydrocarbyl groups can be the same or different, such as butyl ethyl magnesium, (b) a transition metal compound of Groups IVa, Va, or VIa of the Periodic Table, such as, for example, titanium tetrachloride, and (c) ethyl aluminum dichloride. In a preferred embodiment the particulate support material is treated with a halogenating agent prior to treatment with the transition metal compound. In a further preferred embodiment, the catalyst component is contacted under conventional polymerization conditions with a minor amount of an alpha-olefin having from 4 to 18 carbon atoms so as to provide a catalyst component comprising 5 to about 100 weight percent prepolymer.</p> |
