MEDIUM DENSITY POLYETHYLENE COMPOSITIONS WITH BROAD ORTHOGONAL COMPOSITION DISTRIBUTION

• Main Authors: LEAF, Michael A, LI, Wen, PENG, Haiqing, STEVENS, Kevin A
• Format: Patent
• Language: English
• Published: 14.12.2023
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

Provided herein are metallocene-catalyzed polyethylene compositions that exhibit a high degree of broad orthogonal composition distribution ("BOCD"), meaning that they have a relatively high degree of short-chain branching in higher-molecular-weight chains, as compared to the short-chain branching in lower-molecular weight chains. The compositions may have 80 to 99.9 wt % units derived from ethylene and 0.1 to 20 wt % units derived from a C3 to C40 α-olefin comonomer; density from 0.925 to 0.950 g/cm3, melt index (I2.16) within the range from 0.1 to 5 g/10 min, and molecular weight distribution (Mw/Mn) within the range from 4.0 to 8.0. The polyethylene compositions may be formed any suitable polymerization method, although methods according to some embodiments may include utilizing a pre-trim catalyst slurry that is optionally combined with trim catalyst solution to achieve on-the-fly adjustment of catalyst ratios for producing these polyethylene compositions among other polyethylene compositions in a production campaign.