Catalyst systems for improved stereoselectivity and broader molecular weight distribution in polymerization of olefins
US6147024A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1999 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Jul 12, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/52
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides a catalyst for the polymerization of olefin that exhibits improved selectivity and broader molecular weight distribution in the polymer product. The catalyst is a conventional supported Ziegler-Natta catalyst in combination with a mixture of at least two electron donors, both having the general formula SiR.sub.m (OR').sub.4-m where R is selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group and a vinyl group; R' is an alkyl group; and m is 0-3, wherein when R is an alkyl group, R may be identical with R'; when m is 0, 1 or 2, the R' groups may be identical or different; and when m is 1, 2 or 3, the R groups may be identical or different. This catalyst produces polypropylene having xylene solubles of 1-7 to 5.1 wt % and a molecular weight distribution of about 10.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.