| abstract |
Disclosed is a high density ethylene polymer comprising a homopolymer of ethylene, or a copolymer of ethylene with at least one comonomer selected from an α-olefin, a cyclic olefin, and linear, branched and cyclic dienes, and having the following properties: (a) a density d (g/cm 3 ) of from 0.951 to 0.980; (b) an M I (g/10 minutes) of more than 3 and not more than 100 (M I is the melt flow rate as measured at 190 °C under a load of 2.16 kg); (c) the polymer satisfying: log a kI ≧ -0.844 log M I + 1.462 [M I is as defined above, and a kI is the Izod impact strength (kgf·cm/cm 2 )]; (d) the polymer satisfying: log M IR ≧ -0.094 log M I + 1.520 [M I is as defined above, and M IR is the H MI /M I ratio in which H MI (g/10 minutes) is the melt flow rate as measured at 190 °C under a load of 21.6 kg and M I is as defined above]; and wherein (e) the d (g/cm 3 ) and the M I (g/10 minutes) satisfy: d ≧ -0.00873 log M I + 0.972 . The ethylene polymer has excellent mechanical properties and excellent moldability, and can be advantageously produced by use of a catalyst comprising (A) a specific transition metal compound containing, as a ligand, an unsubstituted or substituted indenyl group, or di or tri substituted cyclopentadienyl group; (B) an inorganic solid component comprising a particulate inorganic solid having OH groups on a surface thereof and, carried thereon, an organoaluminumoxy compound having an alkyl group; and (C) an organoaluminum compound. |