DUAL CATALYST SYSTEM FOR PRODUCING HIGH-DENSITY POLYETHYLENES WITH LONG-CHAIN ​​BRANCHES.

Abstract

This document describes ethylene-based polymers generally characterized by a melting index less than 1 g / 10 min, a density of 0.93 to 0.965 g / cm3, a CY-a parameter at 190 °C less than 0.2, an average number of short-chain branches per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g / mol that is greater than in a molecular weight range of 40,000 to 60,000 g / mol, and an average number of long-chain branches per 1000 total carbon atoms of the polymer in a molecular weight range of 400,000 to 600,000 g / mol that is greater than in a molecular weight range of 4,000,000 to 6,000,000 g / mol.Ethylene polymers can be used to manufacture pipes, blown films, and blow-molded products, and ethylene polymers can be produced with a dual catalyst system containing a single-atom bridged or two-atom bridged metallocene compound with two indenyl groups or an indenyl group and a cyclopentadienyl group, and a single-atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group with an alkenyl substituent.