High melt flow propylene polymer produced by gas-phase polymerization
US6057407A · kind A · utility
7Cited by
13References
20Claims
0Family size
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Key dates
| Filing date | Jan 7, 1998 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Jan 7, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/905
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process to produce high melt flow propylene polymer comprises polymerizing propylene in the presence of a titanium-containing, magnesium-containing, high activity catalyst and an aluminum alkyl cocatalyst in a gas phase system which uses condensed liquid to control temperature wherein the external catalyst modifier is a tetraalkylorthosilicate, preferably tetraethylorthosilicate, at process conditions of temperature, hydrogen concentration, and Si/Mg, Al/Mg and Al/Si atomic ratios, to produce a high melt flow propylene polymer at high yield.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.