| 摘要 |
A polymerization catalyst is made by first preparing component (a) by reacting under substantially anhydrous conditions a halide of metal in its highest normal valency state, of Group IVa, Va, VIa, or VIIa, or VIII of the Mendeleeff Periodic Table with a metal hydride, or organometallic compound of a metal of Groups I to III of the Table to reduce the halide to one in a lower than normal valency state, mixing this lower halide with another halide of a metal in its highest normal valency state selected from the first mentioned Groups and reacting the added halide with a reducing agent to reduce it to a lower halide, and mixing this component with (b) a zinc dialkyl and a hydride, organometallic compound, organometallic hydride, or organometallic halogen compound of a metal of Group III of the Periodic Table. The reduction of the halides is preferably effected in an inert diluent. The catalyst is used to polymerize ethylene, propylene, butadiene, and in particular isoprene. During the polymerization diisopropyl ether may be present. In the examples isoprene is polymerized with a catalyst consisting of (a) VCl3 + TiCl3 + (b) Al(C2H5)3 + Zn(C2H5)2, in varying proportions.
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