PROCESS FOR PREPARING ETHYLENE POLYMER AND ETHYLENE POLYMER

摘要

The process for preparing an ethylene polymer according to the invention comprises homopolymerizing ethylene or copolymerizing ethylene and an .alpha.-olefin of 3 to 20 carbon atoms at a temperature of not lower than 80 .degree.C in the presence of a catalyst comprising (A) a specific Group IVB transition metal compound, (B) (B-1) an organoaluminum oxy-compound and/or (B-2) a compound which reacts with the Group IVB transition metal compound (A) to form an ion pair, and optionally, (C) an organoaluminum compound. According to the process of the invention, an ethylene (co)polymer having a high molecular weight can be obtained even at a high polymerization temperature. Further, since the polymerization can be carried out at a temperature higher than those in the conventional processes, a small-sized heat removal device can be used to decrease the equipment cost.