Metallocene preparation and use
CA 2177407 C · Owner: Phillips Petroleum Company · Inventors: Peifer, Bernd; Welch, M. Bruce; Alt, Helmut G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Double bound metallocenes i.e. metallocenes having a cyclopentadienyl-containing radical that is bound to a transition metal both by a pi bond and by a sigma carbon bond of a substituent of that same cyclopentadienyl-containing radical can be prepared by reducing metallocenes having a cyclopentadienyl-containing radical having at least one an unsaturated substituent. Also a process for producing polymers comprising contacting at least one olefinic monomer under suitable polymerization conditions with such double bound metallocenes.
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 May 27, 1996 and granted July 4, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 27, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 27, 2018.
- 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.