| 摘要 |
a -Olefins are polymerized in the presence of a catalyst made by partially reducing a transition metal tetrahalide with a reducing metal having an electro-negativity of 1.6-1.9 in Panling's scale of electro-negatives in the presence of a minor amount of an aluminium halide and activating the resulting reaction product with an organo metallic compound. Specified a -olefins are ethylene, propylene, butene-1 and 4-methylpentene-1. Polymerization may be effected in a hydrocarbon solvent in batchwise or continuous processes. Examples describe the polymerization of ethylene and propylene to yield crystalline polymers.ALSO:In a process for preparing a polymerisation catalyst a transition metal tetrahalide (e.g. TiCl4) is reduced with a metal having an electronegactivity of 1.6 to 1.9 on the Pauling scale (e.g. V, Cr, Fe, Co, Ni, Cu, Zn and Ga) in the presence of an aluminium halide (e.g. AlCl3) before activating with an organometallic compound, e.g. an aluminium alkyl. |
