Group 4 metal amidinate catalysts and addition polymerization process using same

A process for preparing polymers of addition polymerizable monomers comprising contacting an addition polymerizable monomer under addition polymerization conditions with a catalyst composition comprising:

• 1) a Group 4 metal complex corresponding to the formula:
• ##STR6## MXpX'q, or a dimer thereof, wherein:
• M is titanium, zirconium or hafnium in the +2, +3 or +4 formal oxidation state;
• R is an inert ligand group of up to 20 nonhydrogen atoms;
• and
• R' independently each occurrence is a group selected from hydrocarbyl, sily, halohydrocarbyl and mixtures thereof, said R' having up to 10 nonhydrogen atoms;
• X is an anionic ligand group having up to 40 atoms exclusive of the class of ligands that are cyclic, delocalized, n-bound ligand groups;
• X' independently each occurrence is a neutral Lewis base ligating compound, having up to 20 atoms;
• p is 1, 2 or 3, and is one less than the formal oxidation state of M;
• and
• q is 0, 1 or 2, and
• 2) an activating cocatalyst;
• the molar ratio of 1) to 2) being from 1:10,000 to 100:1;
• or
• B) the reaction product formed by converting 1) to an active catalyst by use of an activating technique.