Process using borane derived catalysts for preparation of syndiotactic vinyl aromatic polymers
CA 2113177 A1 · Owner: Campbell, Richard E. Jr. · Inventors: Campbell, Richard E. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing syndiotactic vinyl aromatic polymers comprising contacting at least one polymerizable vinyl aromatic monomer under polymerization conditions with a catalyst comprising a compound corresponding to the formula: LmMXn + RA wherein L, is a delocalized .pi.-bonding group containing up to 50 nonhydrogen atoms; m is 0 or 1; M is a metal of Group 4 of the Periodic Table; X each occurrence is an inert, anionic ligand containing up to 20 nonhydrogen atoms; n is an integer greater than or equal to 1 and the sum of m and n is one less than the valence of M; and RA is RB(C6F5)C3, where R is hydride, hydrocarbyl silyl, a, combination thereof or a substituted derivative thereof …
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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 July 10, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 10, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 10, 2014.
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Timeline
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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.