CATALYSTS, METHOD OF PREPARING THESE CATALYSTS AND METHOD OF USING SAID CATALYST

摘要

A catalyst is prepared by (a) combining, in a suitable solvent or diluent, at least one first component consisting of a bis(cyclopentadienyl) derivative of a Group IV-B metal containing at least one substituent capable of reacting with a second component, which second component comprises a cation which will irreversibly react with at least one substituent in said first component and a non-coordinating anion which is a single coordination complex comprising a plurality of radicals covalently coordinated to and shielding a central formally charge-bearing metal or metalloid atom which anion is bulky and stable to any reaction involving the cation of the second component but sufficiently labile to permit displacement by an olefin, diolefin, and/or acetylenically unsaturated monomer, and (b) maintaining the contacting in step (a) for a sufficient period of time to permit the cation of said second component to react with said substituent contained in said first component, thereby forming an active catalyst either as a direct product or as a decomposition product thereof. Many of the catalysts thus formed are stable and isolable and may be recovered and stored. The catalysts may be preformed and then used to polymerize olefins, diolefins and/or acetylenically unsaturated compounds either alone or in combination with each other or with other monomers or the catalysts may be formed in situ during polymerization by adding the separate components to the polymerization reaction. The catalyst will be formed when the two components are combined in a suitable solvent or diluent at a temperature within the range from about -100.degree.C to about 300.degree.C. The catalysts thus prepared afford better control of polymer molecular weight and are not subject to equilibrium reversal. The catalysts thus produced are also less pyrophoric than the more conventional Ziegler-Natta olefin polymerization catalysts. Certain of the catalysts also yield homopolymers of .alpha.-olefins having relatively high molecular weights. Certain of these catalysts also yield copolymers containing significantly more comonomer, many of which copolymers will be elastomeric.