Crystalline polymers of propylene having improved processability in the molten state and process for their preparation
US7074871B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 2003 |
| Grant date | Jul 11, 2006 |
| Priority date | — |
| Expiry date | Feb 11, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F110/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Crystalline polymers and copolymers of propylene having total MIL values>2 g/10 minutes, total [η] values in tetrahydronaphthalene at 135° C.≦2/8 dl/g, Mw/Mn values>20, a fraction insoluble in xylene at 25° C.≧94, and including from 10 to 60% by weight of a fraction (A) having [η]≧2.6, are prepared by way of sequential polymerization in at least two stages, in the presence of particular Ziegler-Natta catalysts supported on magnesium halides. These polymers have high melt strength, high mechanical properties, and are particularly adequate for the manufacture of articles by using various conversion technologies, such as for example extrusion in thin sheets to be subjected to thermoforming, as well as for injection molding, and blow molding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.