Modified monocyclopentadienyl transition metal/alumoxane catalyst system for polymerization of olefins

Claim 1

A catalyst system comprising: (A) a transition metal compound or lanthanide metal compound of the formula: ##STR7## wherein M is a transition metal or lanthanide metal atom; (C 5 H 5-y-x R x ) is a cyclopentadienyl ring which is substituted with from zero to five substituent groups R, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each substituent group R is, independently, a radical selected from the group consisting of C 1 -C 20 hydrocarbyl radicals; substituted C 1 -C 20 hydrocarbyl radicals wherein one or more hydrogen atoms is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, an alkylborido radical, or other radical containing a Lewis acidic or basic 18 functionality; C 1 -C 20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the Group IV A of the Periodic Table of Elements; halogen radicals; amido radicals; phosphido radicals; alkoxy radicals; alkylborido radicals; and other radical containing Lewis acidic or basic functionality; or (C 5 H 5-y-x R x ) is a cyclopentadienyl ring in which two adjacent R-groups are joined forming C 4 -C 20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand; (JR' z-1-y ) is a heteroatom ligand in which J is an element with a coordination number of three from Group V A or an element with a coordination number of two from Group VIA of the Periodic Table of Elements, each R' is, independently a radical selected from the group consisting of C 1 -C 20 hydrocarbyl radicals and substituted C 1 -C 20 hydrocarbyl radicals wherein one or more hydrogen atom is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, an alkylborido radical, or a radical containing a Lewis acidic or basic functionality; and "z" is the coordination number of the element J; each Q is, independently, an univalent anionic ligand selected from the group consisting of halide, hydride, a substituted or unsubstituted C 1 -C 20 hydrocarbyl, alkoxide, aryloxide, amide, and phosphide provided that where Q is a hydrocarbyl ligand Q cannot be a substituted or unsubstituted cyclopentadienyl ring or both Q together are an alkylidene, a cyclometallated hydrocarbyl or a divalent anionic chelating ligand; "n" and "p" are integer numbers such that n+2 and p+3 are equal to the oxidation state of M and the oxidation state of M is 3 or greater; "y" is 0 or 1 when "w" is greater than 0; "y" is 1 when "w" is 0; when "y" is 1, T is a covalent bridging group containing a Group III A, IV A, V A, or VIA element; L is a neutral Lewis base where "w" denotes a number from 0 to 3; and (B) an alumoxane; and (C) a modifier of the formula R".sub.a-c E(G-R".sub.b-1).sub.c or R"(G-R".sub.b-1) wherein G is a Group VA or VIA element and "b" is equal to the coordination number of G, E is a Group IVA or VA element and "a" is equal to the coordination number of E, "c" is an integer from 1 to 4 but not greater than "a", and each R" is independently a hydrogen, hydrocarbyl or substituted hydrocarbyl radical.