Metallocene catalysts for synthesis of high-melting polyolefin copolymer elastomers
US6479685B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 2000 |
| Grant date | Nov 12, 2002 |
| Priority date | — |
| Expiry date | Dec 29, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Metallocene catalysts having plural coordination geometries for synthesis of high melting polyolefin copolymers suitable as thermoplastic elastomers. The inventive catalysts comprise unbridged, substituted or unsubstituted cyclopentadienyl metallocene catalysts that are capable of inter-converting between states with different polymerization or copolymerization characteristics, which interconversion is controlled by selecting the substituents of the cyclopentadienyl ligands so that the rate of interconversion of the two states is within several orders of magnitude of the rate of formation of a single polymer chain. Where ri>rf the polymer can be characterized as multiblock; where ri<rf, the result is a polymer blend and where ri/rf is close to 1, the resulting polymer is a mixture of blend and multiblock. The inventive metallocene catalysts are able to interconvert between more than two states, with embodiments of four states being shown in FIG. 2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.