Ethylene polymer and processes for obtaining it
US6291602A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1999 |
| Grant date | Sep 18, 2001 |
| Priority date | — |
| Expiry date | Apr 2, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2410/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Ethylene polymer having a blow-up ratio (R.sub.B) of at least 1.4, a resistance to crazing under stress (ESCR) of at least 55 h and a melt index (MI.sub.5) of at least 0.2 g/10 min. Processes for obtaining this ethylene polymer using different catalytic systems, the first based on titanium and zirconium used in a polymerization in two reactors; the second consisting of a mixture of a titanium catalyst and a titanium and zirconium catalyst, used in a polymerization in two reactors; the third based on chromium on a support comprising at least two constituents chosen from silica, alumina and aluminium phosphates, used in a polymerization in a single or in two reactors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.