Hafnium metallocene catalyst for the polymerization of olefins
CA 1302384 C · Owner: Ewen, John A. · Inventors: Ewen, John A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The, present invention provides a catalyst system for the polymerization and copolymerization of olefins with the system comprising a chiral stereorigid hafnium metallocene catalyst in combination with an aluminum compound. The aluminum compound is preferably an alumoxane and may be a mixture of alumoxane and trimethyl aluminum. It was discovered that this mixture causes a transformation of the catalyst over time. The catalyst system may also include a solvent to increase the solubility of the metallocene catalyst. It was discovered that these catalyst systems produce useful polymer products with molecular weights greater than 10,000.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted June 2, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 2, 2009.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.