Process for production of high melt flow propylene-based polymer and product from same
Disclosed are catalyst compositions having an internal electron donor which includes a 3,6-di-substituted-1,2-phenylene aromatic diester. Ziegler-Natta catalyst compositions containing the present catalyst compositions exhibit very high hydrogen response, high activity, high selectivity and produce propylene-based olefins with high melt flow rate.
1. A procatalyst composition comprising:
a magnesium moiety, a titanium moiety, and a substituted-1,2-phenylene dibenzoate having structure (I),
wherein R 1 -R 14 are the same or different, each of R1 and R4 is a methyl group, at least one of R2 or R3 is hydrogen and at least one is a cyclohexyl group, and each of R5-R14 is selected from hydrogen, a halogen, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyloxy group having 1 to 20 carbon atoms.
2. A procatalyst composition as defined in claim 1 , wherein the magnesium moiety comprises a magnesium halide.
3. A catalyst composition comprising the procatalyst composition as defined in claim 1 , and a cocatalyst.
4. A catalyst composition as defined in claim 3 , wherein the cocatalyst comprises an alkyl aluminum compound.
5. A catalyst composition comprising the procatalyst composition as defined in claim 1 , a cocatalyst and an external electron donor.
6. A catalyst composition as defined in claim 5 , wherein the external electron donor comprises an alkoxysilane.
7. A catalyst composition as defined in claim 5 , wherein the external electron donor comprises dicyclopentyldimethoxysilane, di-tert-butyldimethoxysilane, methylcyclohexyldimethoxysilane, methylcyclohexyldiethoxysilane, ethylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, di-n-propyldimethoxysilane, n-propyltrimethoxysilane, diisobutyldimethoxysilane, diisobutyldiethoxysilane, isobutylisopropyldimethoxysilane, di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, diethylaminotriethoxysilane, cyclopentylpyrrolidinodimethoxysilane, bis(pyrrolidino)dimethoxysilane, bis(perhydroisoquinolino)dimethoxysilane, and dimethyldimethoxysilane.
8. A catalyst composition as defined in claim 3 , further containing an activity limiting agent.
9. A procatalyst composition as defined in claim 1 , wherein the magnesium moiety comprises magnesium chloride.
10. A catalyst composition as defined in claim 5 , wherein the cocatalyst comprises an alkyl aluminum compound.
11. A catalyst composition as defined in claim 5 , further comprising an activity limiting agent.
12. A process for producing an olefin-based polymer comprising:
contacting under polymerization conditions an olefin and optionally one or more comonomers with a procatalyst composition as defined in claim 1 , and a cocatalyst, an external electron donor, and optionally an activity limiting agent.