US Patent 9175119 Polymers

Copolymers of ethylene and α-olefins having (a) a density in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range 0.01-50 g/10 min, (c) a molecular weight distribution (Mw/Mn, by conventional GPC) in the range 2.0-4.5, (d) a comonomer partition factor, Cpf>1, and (e) a melt index MI2 (2.16 kg, 190° C.) normalized Dow Rheology Index (DRI), [DRI/MI2] in the range 3-20. The copolymers may be prepared using catalyst systems containing activating supports. The copolymers are suitably prepared in the gas phase preferably in a single reactor. The copolymers exhibit unique properties in particular with respect to their rheology.