Gas-phase or slurry polymerization process for the preparation of an olefin polymer

摘要

The present invention provides an ethylene copolymer comprising constituent units (a) derived from ethylene and constituent units (b) derived from an alpha -olefin having 3 to 20 carbon atoms, the ethylene copolymer being characterized in that (A) the ethylene copolymer has a density (d) of 0.86 to 0.95 g/cm3; (B) the ethylene copolymer has a MFR of 0.001 to 50 g/10 min as measured at a temperature of 190 DEG C. and a load of 2.16 kg; (C) the melt tension (MT) and MFR of the ethylene copolymer satisfy the relation log MT>-0.66log MFR+0.6; and (D) the temperature (T) at which the exothermic curve of the ethylene copolymer measured by a differential scanning calorimeter (DSC) shows the highest peak and the density (d) satisfy the relation T<400d-250.