Process for preparation of syndiotactic vinyl aromatic polymers
CA 2024830 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 one or more aromatic monomers under polymerization conditions with a catalyst corresponding to the formula: CpmMxnx'p+A-, wherein:, Cp is a single n5-cyclopentadienyl or n5substituted cyclopentadienyl group;, M is a metal of Group 3 4, 5, 6, 8, 9, 10 or, the Lanthanide Series of the Periodic Table; X each occurrence is an inert anionic lignd with the proviso that at least one X is R; X' is an inert, neutral, donor ligand; R is hydrocarbyl, silyl, a combination thereof or a substituted derivative thereof having up to 20 carbon, silicon or carbon and silicon atoms; m and p are independently 0 or 1;, n is an …
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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 September 7, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 7, 2012.
- 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.