Polypropylene solution polymerization process

1. A process for continuous solution polymerization of propylene, optionally ethylene, and further optionally one or more C 4-30 α-olefins and/or one or more conjugated or nonconjugated dienes under continuous, solution polymerization conditions to prepare a polymer or interpolymer having a M w in the range of from 200,000 to 500,000 g/mol, said process comprising conducting the polymerization in the presence of a catalyst composition comprising a hafnium complex of a polyvalent aryloxyether and a cocatalyst and having a catalyst activity in the range of greater than 0.55 g/μg based on weight of polymer to weight of transition metal;

wherein the continuous solution polymerization process operates at a temperature in the range of 120 to 250° C., with a propylene concentration in the reactor of 8 percent or less, and a solids content of the reaction mixture of 15 percent or greater and a propylene conversion rate of greater than 85 mole percent; and

wherein under operating conditions of the polymerization unreacted monomer or monomers are not separated from the remaining solvent of a reaction mixture prior to recycling of the reaction mixture.

2. The process of claim 1 wherein the metal complex corresponds to the formula:

where:

R 20 independently each occurrence is a divalent aromatic or inertly substituted aromatic group containing from 5 to 20 atoms not counting hydrogen;

T 3 is a divalent hydrocarbon or silane group having from 3 to 20 atoms not counting hydrogen, or an inertly substituted derivative thereof; and

R D independently each occurrence is a monovalent ligand group of from 1 to 20 atoms, not counting hydrogen, or two R D groups together are a divalent ligand group of from 1 to 20 atoms, not counting hydrogen; and

wherein the continuous solution process operates at a temperature from 120 to 250 ° C. and a pressure from 100 kPa to 300 MPa.

3. The process of claim 1 wherein the polymerization temperature is from 130 to 200 ° C.

4. The process of claim 1 wherein a monomer mixture consisting essentially of propylene and ethylene is polymerized.

5. The process of claim 1 wherein the cocatalyst is alumoxane present in an amount to provide a molar ratio based on Hf from 20:1 to 150:1.

6. The process of claim 5 wherein the alumoxane is tri(isobutyl)aluminum modified methylalumoxane or tri(n-octyl)aluminum modified methyalumoxane.

7. a process according to claim 1 wherein the metal complex corresponds to one the formulas:

wherein, R D independently each occurrence is chloro, methyl or benzyl.

8. The process of claim 7 wherein the metal complex is selected from the group consisting of:

A) bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxy)-1,3-propanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxy)-1,3-propanediylhafnium (IV) dichloride, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxy)-1,3-propanediylhafnium (IV) dibenzyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxy)-1,3-propanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxy)-1,3-propanediylhafnium (IV) dichloride, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxy)-1,3-propanediylhafnium (IV) dibenzyl,

B) bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-1,4-butanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-1,4-butanediylhafnium (IV) dichloride, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-1,4-butanediylhafnium (IV) dibenzyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-1,4-butanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-1,4-butanediylhafnium (IV) dichloride, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-1,4-butanediylhafnium (IV) dibenzyl,

C) bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxy)-2,4-pentanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxy)-2,4-pentanediylhafnium (IV) dichloride, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxy)-2,4-pentanediylhafnium (IV) dibenzyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxy)-2,4-pentanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxy)-2,4-pentanediylhafnium (IV) dichloride, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxy)-2,4-pentanediylhafnium (IV) dibenzyl,

D) bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxymethyl)methylenetrans-1,2-cyclohexanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxymethyl)methylenetrans-1,2-cyclohexanediylhafnium (IV) dichloride, bis((2-oxoyl-3-(1,2,3,4,6,7,8,9-octahydroanthracen-5-yl)-5-(methyl)phenyl)-2-phenoxymethyl)methylenetrans-1,2-cyclohexanediylhafnium (IV) dibenzyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-methylenetrans-1,2-cyclohexanediylhafnium (IV) dimethyl, bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-methylenetrans-1,2-cyclohexanediylhafnium (IV) dichloride, and bis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)-methylenetrans-1,2-cyclohexanediylhafnium (IV) dibenzyl.