Production of bridged hafnocenes
CA 2299536 A1 · Owner: Lin, Ronny W. · Inventors: Lin, Ronny W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Racemic, bridged hafnocene is produced in enhanced yield by reacting a hafnium halide-aliphatic polyether adduct that has been formed and/or heated at one or more temperatures of at least 40 ~C, and a metallated bis(cyclopentadienylmoiety-containing) ligand, at one or more temperatures for a sufficient period of time such that a racemic, bridged hafnocene is produced. The reaction is performed in the substantial absence of tetrahydrofuran and/or any other ether solvent or diluent that causes the formation of a tarry residue in the reaction mixture.
Read the whole patent
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
- Filed August 11, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 11, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 11, 2020.
- 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.