Polyolefin polymerization process, semicrystalline ethylene-based polymer made from it, and articles made from the polymer

摘要

A polymerization process comprising: polymerizing ethylene and optionally one or more α-olefins in the presence of a catalyst to form a polymer based on semicrystalline ethylene in at least one reactor; the catalyst comprising an organometallic catalyst thus forming a polymer composition based on ethylene in the at least one reactor, wherein the catalyst is a metal complex of a polyvalent aryloxyether corresponding to the formula: ** Formula ** Where M3 is Ti, Hf or Zr, preferably Zr; Ar4 is independently in each case a substituted C9-20 aryl group, wherein the substituents, independently in each case, are selected from the group consisting of alkyl groups; cycloalkyl; and aryl; and halo-, trihydrocarbylsilyl- and halohydrocarbyl-substituted derivatives thereof, with the proviso that at least one substituent lacks coplanarity with the aryl group to which it is attached; T4 is independently in each case a cycloalkylene, cycloalkenylene or C2-20 alkylene group, or an inertly substituted derivative thereof; R21 is independently in each case a hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, alkoxy or di (hydrocarbyl) amino group of up to 50 atoms excluding hydrogen; R3 is independently in each case hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, alkoxy or amino of up to 50 atoms without counting hydrogen, or two R3 groups in the same arylene ring together or an R3 group and an R21 group in the same or in a different arylene ring together they form a divalent ligand group attached to the arylene group in two positions or join two different arylene rings together; and RD is independently in each case halo or a hydrocarbyl or trihydrocarbylsilyl group of up to 20 atoms excluding hydrogen, or 2 RD groups together are a hydrocarbylene, hydrocarbodiyl, diene or poly (hydrocarbyl) silylene group; wherein step (A) is carried out in the presence of triethylaluminum from 5 to 20 mmol / m3; and wherein step (A) is carried out in the presence of both of the following conditions: (i) triethylaluminum molar ratio to the catalyst from greater than 0: 1 to 65: 1; and (ii) molar ratio of triethylaluminum to modified methylalumoxane from 0.1: 1 to 5: 1.