Multi reactor solution polymerization, polyethylene and polyethylene film
AssigneeNOVA Chemicals (International) S.A.
InventorsXiaoChuan Wang, Niousha Kazemi, Stephen Brown, Lawrence VanAsseldonk, Stephen Salomons
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Abstract
This disclosure relates to a continuous solution three reactor polymerization process. Process solvent, ethylene, optional comonomers, optional hydrogen and a single site catalyst system are injected into a first and second reactor configured in parallel to one another. A third reactor receives effluent from the first reactor, the second reactor, or a combination of the first and second reactors. Fresh monomer is feed to the third reactor for further polymerization and to give a final polyethylene product.
Claims48
A polyethylene product composition comprising:
- from 35 to 75 wt % of a first polyethylene which is an ethylene copolymer having a density of from 0.875 to 0.916 g/cm3, a melt index I2 of from 0.1 to 5 dg/min, and a molecular weight distribution Mw/Mn of from 1.6 to 2.4;
- from 10 to 40 wt % of a second polyethylene selected from an ethylene copolymer or an ethylene homopolymer having a density of from 0.945 to 0.975 g/cm3, a melt index I2 of from 1.0 to 20 dg/min, and a molecular weight distribution Mw/Mn of from 1.6 to 2.4;
- and
- from 10 to 40 wt % of a third polyethylene which is an ethylene copolymer having a density of from 0.880 to 0.936 g/cm3, a melt index I2 of from 0.1 to 100 dg/min, and a molecular weight distribution Mw/Mn that is greater than the molecular weight distribution Mw/Mn of either the first or second ethylene polymer components;
- wherein the polyethylene product composition has a density of ≤0.939 g/cm3, a melt index I2 of from 0.1 to 10 dg/min, a unimodal profile in a gel permeation chromatograph (GPC) and a multimodal profile in a TREF analysis.
A film layer which has a dart impact strength of ≥600 g/mil, a MD 1% secant modulus of ≥170 MPa, a slow puncture value of ≥65 J/mm, a machine direction (MD) tear of ≥250 g/mil, and a seal initiation temperature (SIT) of ≤105° C.
Dependencies are inferred from the claim text.