PREPARATION OF POLYETHYLENE

摘要

PROBLEM TO BE SOLVED: To provide a method for preparing polyethylene having a single mode distribution of molecular weight and improved mechanical characteristics. SOLUTION: The method for preparing a polyethylene resin having a single mode distribution of molecular weight in a single polymerization reactor by copolymerizing ethylene and anα-olefin comonomer having from 3 to 8 carbon atoms is provided, wherein the polyethylene resin contains a blend of a high molecular weight fraction polymerized by use of a first chromium-based catalyst of a system and a low molecular weight fraction polymerized by use of a second chromium-based catalyst of the system, and an uptake of the comonomer in the high molecular weight fraction is greater than an uptake of the comonomer in the low molecular weight fraction so that a difference in density between the high and low molecular weight fraction ranges from 0.01 to 0.03 g/cc.