Process for the preparation of multimodal high density polyethylene
US12012504B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2019 |
| Grant date | Jun 18, 2024 |
| Priority date | — |
| Expiry date | May 16, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2314/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention provides a process for the preparation of a multimodal high density polyethylene (HDPE) having a melt flow rate (MFR2) of 0.1 to 4.0 g/10 min, said process comprising: (i) polymerising ethylene in a first polymerisation stage in the presence of a Ziegler-Natta catalyst to prepare a first ethylene homopolymer having a MFR2 from 10 to 500 g/10 min; (ii) polymerising ethylene in a second polymerisation stage in the presence of said catalyst and said first ethylene homopolymer to prepare an ethylene homopolymer mixture comprising said first ethylene homopolymer and a second ethylene homopolymer, said mixture having a MFR2 from 50 to 1000 g/10 min; and (iii) polymerising ethylene and at least one alpha-olefin comonomer in a third polymerisation stage in the presence of said catalyst and said ethylene homopolymer mixture to prepare said multimodal HDPE.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.