Catalysts for thermoplastic elastomeric olefin polymers
US6566544B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1998 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Feb 16, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/788
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention is directed to novel catalysts the structure and activity of which can be controlled to produce a wide range of alpha olefin polymers and co-polymers, and preferably for the production of stereoblock poly alpha olefins comprising a wide range of preselected amorphous and crystalline segments for precise control of the physical properties thereof, principally elastomeric thermoplastic properties. More specifically, this invention is directed to novel catalysts and catalysts systems for producing stereoblock polypropylene comprising alternating isotactic and atactic diastereosequences, which result in a wide range of elastomeric properties. The amount and numbers of crystalline sections, the isotactic pentad content, the number and length of intermediate atactic chains and overall molecular weight are all controllable by the steric structure of the catalysts and the process conditions. The novel catalysts provided by the present invention are ligand-bearing non-rigid metallocenes the geometry of which can be controlled on a time scale that is slower than the rate of olefin insertion, but faster than the average time to construct (polymerize) a single polymer chain, in …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.