Exxon Chemical Patents, Inc.

Richard Allen Fisher

Donna Jean Crowther

Howard W Turner

Jo Ann Canich

John F Walzer, Jr

George Alan Vaughan

Gregory G Hlatky

Charles Stanley Speed

Howard William Turner

Bernard Jean Folie

This invention relates to single site catalyst systems comprising activated bimetallocyclic transition metal compounds, and the use of these catalyst systems for the polymerization of ethylenically and acetylenically unsaturated monomers. The bimetallocyclic compounds comprise two metal atoms, selected from the group consisting of Group 4 or Group 5 metal atoms, connected through two covalent bridging links so as to form a cyclic compound having delocalized bonding in the cyclic structure. The exemplary bimetallocyclic compound bis-M-(trimethylsilyl-methylidyne) tetrakis-(trimethylsilylmethyl) ditantalum activated with alumoxane and borate compounds is shown to be useful for preparing ethylene polymers having M.sub.n of at least 267,000 and MWD of about 2.3.

Bimetallocyclic transition metal catalyst systems

A polymerization process for olefinically or acetylenically unsaturated monomers is disclosed. The process comprises contacting the one or more of the monomers with a suitable ionic catalyst system in the presence of a long-chain, linear alkyl ligand-containing organo aluminum compound. Preferred ionic catalysts are derived from 1) bridged hafnium compounds, 2) silicon bridged monocyclopentadienyl titanium compounds and 3) unbridged, bulky Group 15 containing, bulky monocyclopentadienyl titanium compounds, and a non-coordinating anion precursor compound. A class of preferred anion precursors consists of hydrated salts comprising a Group 1 or 2 cation and a non-coordinating anion. Using the preferred ionic catalysts high temperature processes, e.g., at or above 90.degree. C. can be conducted to prepare polyolefins, particularly ethylene copolymers, of both high molecular weight and high comonomer content.

High temperature olefin polymerization process

This invention relates to non-Group 4 transition metal compositions useful as olefin polymerization catalysts, wherein the transition metal is in a high oxidation state. The invention further relates to design of new ligand systems and methods of preparing and using the same. Compositions useful as catalyst precursors are neutral transition metal complexes comprising the unique ligand systems of the invention. The inventive compositions may be activated to a catalytic state by ion-exchange reagents or by Lewis acids.

Transition metal olefin polymerization catalysts

This invention relates to processes using non-Group 4 transition metal compositions useful as olefin polymerization catalysts, wherein the transition metal is in a high oxidation state. The invention further relates to design of new ligand systems and methods of preparing and using the same. Compositions useful as catalyst precursors are neutral transition metal complexes comprising the unique ligand systems of the invention. The inventive compositions may be activated to a catalytic state by ion-exchange reagents or by Lewis acids.

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League City, TX, United States of America

Richard Allen Fisher