High melt strength polypropylene
US7365136B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2005 |
| Grant date | Apr 29, 2008 |
| Priority date | — |
| Expiry date | Mar 8, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/905
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention concerns a high melt strength propylene polymer or copolymer suitable for manufacturing foams and thermoformed product exhibiting a melt strength of at least 3 g and comprising a high molar mass portion and a low or medium molar mass portion. The polymers are produced by subjecting propylene and optionally other olefins to polymerization in a plurality of polymerization reactors connected in series, employing different amounts of hydrogen as a molar mass modifier in at least two of the reactors, and carrying out the polymerization reaction in the presence of a catalyst system capable of catalyzing the formation of a high molar mass polymerization product having a MFR2 of less than 0.1 g/10 min and a low or medium molar mass polymerization product having a MFR2 of more than 0.5 g/10 min.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.