Ziegler-Natta (Z-N) catalyst systems can be used to produce linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE) resins. However, some Z-N-catalyzed polymers with high tear and impact strength have shown limited usefulness for film and sheet applications because the polymers can have poor extrudability.
An example is superhexene linear low density polyethylenes, which have shown excellent tear and impact strength properties with poor extrudability.
Additionally, chromium-catalyzed LLDPE, MDPE, and HDPE products have demonstrated good extrudability but poor tear and impact strength properties for film applications.
It is desirable to produce Z-N catalyzed polymers that provide good tear and impact strength properties while demonstrating extrudability similar to that of chromium-catalyzed polymers.
USPTO Backgrounds
USPTO Backgrounds