Termination of anionic polymerization
CA 2080595 C · Owner: Shell Canada Limited · Inventors: Chamberlain, Linda Rae; Stevens, Craig Aldred; Gibler, Carma Joleen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This is an improvement upon a process which comprises anionically polymerizing monomers with an anionic polymerization initiator in a suitable solvent thereby creating a living polymer. The improvement comprises terminating the polymerization by the addition of a terminating agent selected from the group consisting of hydrogen or its isotopes, boranes, ammonia halogens, hydrocarbons containing a C-H group where the carbon is connected directly to a triply-bound carbon or to two doubly-bound carbons and silanes.
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 13, 1991 and granted December 28, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 13, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 13, 2013.
- 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.