Polyethylene and process for production thereof

摘要

This invention relates to a process for polymerizing olefins in which the amount of trimethylaluminum in a methylalumoxane solution is adjusted to be from 1 to 25 mol %, prior to use as an activator, where the mol % trimethylaluminum is determined by 1H NMR of the solution prior to combination with any support. This invention also relates to a process for polymerizing olefins in which the amount of an unknown species present in a methylalumoxane solution is adjusted to be from 0.10 to 0.65 integration units prior to use as an activator, where the amount of the unknown species is determined by the 1H NMR spectra of the solution performed prior to combination with any support. Preferably, the methylalumoxane solution is present in a catalyst system also comprising a metallocene transition metal compound.

主权项

1. A process to produce block ethylene copolymers comprising adjusting the amount of trimethyl aluminum in a catalyst system comprising methylalumoxane solution and a metallocene transition metal complex prior to use as an activator to obtain block segments with [HHH] comonomer triad fractions that differ by at least 5% relative to each other.