Olefin polymerization catalysts

Claim 1

A catalyst system comprising: (A) a Group IV B transition metal component of the formula: ##STR5## wherein M is Zr, Hf or Ti; (C 5 H 5-y-x R x ) is a cyclopentadienyl ring which is substituted wit from zero to five groups R, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each R is, independently, a radical selected from a group consisting of C 1 -C 20 hydrocarbyl radicals, C 1 -C 20 substituted hydrocarbyl radicals wherein one or more hydrogen atoms are replaced by a halogen atom, C 1 -C 20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the Group IV A of the Periodic Table of Elements and halogen radicals 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-l-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 VI A of the Periodic Table of Elements, each R' is, independently a radical selected from a 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 atom, and "z" is the coordination number of the element J; each Q is, independently any univalent anionic ligand or two Q's are a divalent anionic chelating agent; "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 IV A or V A element; L is a Lewis base where "w" denotes a number from 0 to 3; and (B) an alumoxane.