Metallocenes and catalysts for olefin-polymerisation
CA 2277127 A1 · Owner: Nifant'Ev, Ilya E. · Inventors: Nifant'Ev, Ilya E.; Bagrov, Vladimir V.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A class of metallocenes of formula (I): (ZR1m)n(Cp)(A)rMLpL'q (I) wherein (ZR1m)n is a divalent group bridging Cp and A Cp is a heterocyclic , cyclopentadienyl group of formula (II) or (II') wherein one of X or Y is a , single bond the other being an heteroatom; R2 and R3 are hydrogen halogen or , a hydrocarbon radical, optionally containing heteroatoms; R4 is halogen or an hydrocarbon radical, optionally containing heteroatoms; the group A is a cyclopentadienyl derivative or is equal to Cp; M is Ti Zr or Hf; m is 1 or 2; , n ranges from 0 to 4; r is 0 or 1; p and q range from 0 to 3; and a ranges from 0 to 4. Moreover, are disclosed catalyst systems containing these metallocenes, …
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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
- Filed November 4, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 4, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 4, 2020.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.