Patent ID: 6559253
Filing Date: 2003-05-06
Classification: C08F,C08L,Y10S

Abstract:
A polymerization process for ethylene copolymers having a density of about 0.87 to about 0.930 comprising contacting, under homogeneous polymerization conditions at a reaction temperature at or above 140Â° C. to 220Â° C., ethylene and one or more comonomers capable of insertion polymerization with a hafnocene catalyst complex derived fromA) a biscyclopentadienyl hafnium organometallic compound having i) at least one unsubstituted cyclopentadienyl ligand or aromatic fused-ring substituted cyclopentadienyl ligand, ii) one aromatic fused-ring substituted cyclopentadienyl ligand, and iii) a covalent bridge connecting the two cyclopentadienyl ligands, said bridge comprising a single carbon or silicon atom; and B) an activating cocatalyst, precursor ionic compound comprising a halogenated tetraaryl-substituted Group 13 anion wherein each aryl substituent contains at least two cyclic aromatic rings.