US Patent 10913831 Polyolefin film with improved toughness

A film formed from a polyethylene copolymer using a reduced chromium oxide catalyst, ethylene monomers and a co-monomer selected from butene monomers or 1-hexene, where the polyethylene copolymer has a density in the range of from about 0.935 to about 0.950 g/cm3 and an I21/I5 in a range of about 18.0 to about 30.0. The film formed from the polyethylene copolymer has a dart drop impact (g/μm) that significantly greater as compared to a film of the polyethylene copolymer formed using a silyl chromate catalyst in place of the reduced chromium oxide catalyst. A method of making such films is also provided.