Process for continuously producing propylene-ethylene block copolymer
US4492787A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1982 |
| Grant date | Jan 8, 1985 |
| Priority date | — |
| Expiry date | Aug 30, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F297/083
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to a process for producing a polypropylene-ethylene block copolymer by a continuous multi-stage polymerization comprising a first stage in which polypropylene is polymerized in a first polymerization vessel in the presence of a propylene polymerization catalyst, and a second stage in which propylene and ethylene are copolymerized in a second polymerization vessel, wherein the polypropylene slurry discharged from the first polymerization vessel is supplied to a concentrator to separate said slurry into a concentrated polypropylene slurry and a supernatant liquid, the concentrated polypropylene slurry is then introduced through an upper part of a hydraulic sedimentation classifier to be contacted with a countercurrent of the upward flowing of the supernatant fluid introduced through a lower part of said classifier to obtain hydraulically sedimented polypropylene, and non-hydraulically sedimented polypropylene; the thus obtained hydraulically-sedimented polypropylene is then supplied to the second polymerization vessel or to a further propylene polymerization vessel and the non-hydraulically sedimented polypropylene is then recycled from the classifier to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.