POLYMERIZATION AND COPOLYMERIZATION METHOD OF ETHYLENE USING CATALYST CHELATED WITH CARBODIIMIDE-BASED LIGAND

摘要

PURPOSE: A method for polymerizing and copolymerizing ethylene by using a catalyst chelated with a carbodiimide-based ligand is provided, to obtain an ethylene polymer or copolymer having a large bulk density and the narrow distribution of molecular weight. CONSTITUTION: The method comprises the step of polymerizing or copolymerizing ethylene in the presence of a transition metal compound catalyst component of group IV chelated with a carbodiimide-based ligand, a magnesium-containing support and an organometallic compound cocatalyst of group II or III. The transition metal compound catalyst component of group IV chelated with a carbodiimide-based ligand, is prepared by reacting a Grignard compound of dialkyl magnesium with an alkoxy aluminum to obtain an alkoxy aluminum-magnesium compound; reacting the obtained alkoxy aluminum-magnesium compound with a carbodiimide-based ligand; and reacting the obtained one with a transition metal of group IV. Preferably the carbodiimide-based ligand is represented by the formula 1, wherein W, Y and Z are independently an alkyl group, a phenyl group or a heteroatom-containing alkyl group.