MgCl2/R′nAl(OR)3−n: An Excellent Activator/Support for Transition-Metal Complexes for Olefin Polymerization

• Published in: Chemistry : a European journal Vol. 12; no. 29; pp. 7546 - 7556
• Main Authors: Nakayama, Yasushi, Saito, Junji, Bando, Hideki, Fujita, Terunori
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 05.10.2006; WILEY‐VCH Verlag
• Subjects: activators; FI catalysts; polymerization; polyolefins; supported catalysts
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200600355

A new and effective method for the activation, and simultaneously, immobilization of bis(phenoxyimine) early‐transition‐metal complexes for olefin polymerization (known as FI catalysts), which makes use of MgCl2/R′nAl(OR)3−n as an activator/support, has been developed. Ti‐, Zr‐, and V‐FI catalysts combined with this MgCl2‐based compound can form highly active MgCl2‐supported single‐site catalysts capable of demonstrating superior catalytic properties, compared to the corresponding homogeneous methylaluminoxane‐ (Ti‐ and Zr‐FI catalysts) or alkylaluminum‐activation systems (V‐FI catalysts), in terms of their catalytic activity, molecular weight, stereoselectivity, and comonomer incorporation. Additionally, these new catalysts can produce polymers of significant morphology with high efficiency. Notably, the MgCl2‐based compounds can also effectively activate and immobilize the early‐to‐late transition‐metal complexes that have emerged recently. Thus, the application of MgCl2‐based compounds as activators/supports for transition‐metal complexes for olefin polymerization provides a conceptually new strategy for the development of methylaluminoxane‐ and borate‐free, high‐performance, single‐site catalysts capable of controlling polymer morphology. It's the combination that does the trick: A new and effective method for the activation, and simultaneously, immobilization of bis(phenoxyimine) early‐transition‐metal complexes for olefin polymerization (FI catalysts) has been developed, resulting in MAO‐ and borate‐free, high‐performance, supported single‐site catalysts (see scheme).