Cocatalysts useful for improving polyethylene film properties

摘要

Commonly used triethyl aluminum and tri-isobutyl aluminum cocatalysts can be replaced in olefin polymerizations with a cocatalyst conforming to the formula AlR^z(X^z)_nL^z_m wherein R^z is a linear or branched organic moiety having at least 5 carbons and X^z is a linear or branched organic moiety having at least 5 carbons or heteroatom substituted organic moiety or a heterocyclic moiety having at least 4 atoms and can be anionic (n=2) or dianionic (n=1). X^z can also be hydrogen. The aluminum complex may also be in the form of an adduct complex where L^z is a Lewis base and m=1-3. The general formula is subject to the proviso that when n=2, each X^z may be the same or different and that both X^z moieties may not be hydrogen. Use of the invention enables production of a polyolefin film, such as polyethylene film, exhibiting improved bubble stability and other desirable properties.