Multi-stage process for producing multi-modal linear low density polyethylene
US8409681B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2010 |
| Grant date | Apr 2, 2013 |
| Priority date | — |
| Expiry date | Feb 22, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/139
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process is disclosed for producing a multi-modal linear low density polyethylene in at least two staged reactors connected in series, comprising (i) polymerizing in a first slurry phase stage ethylene monomers with a Ziegler-Natta polymerization catalyst system to obtain a first polyethylene fraction component (A); and (ii) polymerizing in a second gas or slurry phase stage ethylene monomers with a Ziegler-Natta polymerization catalyst system to obtain a second polyethylene fraction component (B). The Ziegler-Natta polymerization catalyst system comprises: 1) a solid procatalyst formed by contacting at least: a) a Mg-alcoholate complex of formula (I) b) an aluminum compound of formula (II); and c) a vanadium compound and a titanium compound having a molar ratio (V:Ti) from 10:90 to 90:10; and 2) one or more organometallic cocatalvsts of formula (III). The linear low density polyethylene shows an improved comonomer composition distribution Formulas (I), (II), and (III) are described herein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.