Catalyst and process for polymerizing aromatic vinyl compound
CA 2061570 A1 · Owner: Miyashita, Akira · Inventors: Miyashita, Akira
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A catalyst for polymerizing an aromatic vinyl compound is provided. The catalyst is represented by the general formula (1):, where M is an element of Group IVa; X1 is a halogen; R1 R2, R3 R4, R5, R6 and R7 are independently hydrogen or an alkyl group having 1 to 6 carbons; R8 is hydrogen or an alkyl group having 1 to 5 carbons; m is an integer of from 1 to 6; and n is an integer of from 4 to 60. A process for polymerizing an aromatic vinyl compound is also provided by using the above catalyst. The catalyst gives an aromatic vinyl polymer having a syndiotactic structure with very high selectivity.
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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 February 20, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 20, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 20, 2014.
- 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.