Process for the polymerization of olefins and block (co)polymers derived from at least one olefin
US5478898A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 23, 1994 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | May 23, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F110/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for the polymerization of at least one olefin is a suspension process employing a hydrocarbon diluent such that at least 70% of the polymer formed is insoluble therein, and employs at least two polymerization reactors. The process includes introducing a first portion of the at least one olefin and a catalyst into a first reactor. The catalyst is composed of bis(cyclopentadienyl)chromium, which may be substituted, supported on an inorganic oxide support and is supplied solely into the first reactor. The at least one olefin is polymerized in the first reactor to provide a first composition composed of a polymer and the catalyst. The first composition is then drawn off from the first reactor and the first composition and another portion of the at least one olefin are introduced into a second reactor and the another portion of the at least one olefin is polymerized in the second reactor in the presence of the first composition. Further, hydrogen is introduced into at least one of the reactors at a partial pressure ranging from 0.01 to 0.50 MPa, the ratio of the hydrogen to olefin partial pressure in this reactor ranging from 0.01 to 3. Additionally, the olefin partial pressur…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.