PROCESS FOR THE PREPARATION OF ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE

摘要

The invention relates to a process for the preparation of ultra high molecular weight polyethylene comprising the steps of: (a) supporting a catalyst onto a support at a temperature of between -8O C and 100 C, said catalyst comprising an organometallic compound and an activator, characterized in that the organometallic compound is a compound according to formula 1 : wherein: M is a metal of group 3 -13 or the lanthanide series, and p is the valency of the metal M; A represents a neutral or anionic spectator ligand whose valency v is 0, 1 or 2, and q is an integer denoting the number of spectator ligands A; Z is an optional bridging moiety, and n is the integer number of parallel bridging moieties Z; Y is a ligand represented by formula 2: wherein the ligand is covalently bonded to the metal M via the imine nitrogen atom, Subi is a substituent, which comprises a group 14 atom through which Subi is bonded to the imine carbon atom, Sub2 is a substituent, which comprises a heteroatom of group 15-16, through which SUb2 is bonded to the imine carbon atom,; r is 1, 2, 3, 4 or 5; L is an optional neutral Lewis basic ligand, and j is an integer denoting the number of neutral ligands L, and X is an anionic ligand that may be independently selected from the group consisting of hydride, halide, alkyl, silyl, germyl, aryl, amide, aryloxy, alkoxy, phosphide, sulfide, acyl, pseudo halides such as cyanide, azide, and acetylacetonate, or a combination thereof; and (b) polymerizing ethylene in the presence of the supported catalyst of step (a), thereby producing ultra high molecular weight polyethylene.