Process for production of high-isoprene butyl rubber
CA 2413611 C · Owner: Glander, Stephan · Inventors: Bohnenpoll, Martin; Glander, Stephan; App, William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for producing polymers comprising repeating units derived from at least one isoolefin monomer at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of at least one organic nitro compound and AlCl3/water wherein the process is conducted in the absence of compounds selected from the group consisting of vanadium compounds zirconium halogenid, hafnium halogenides. Preferably the polymers have a multiolefin content of greater than 2.5 mol% and a molecular weight M w of greater than 240 kg/mol.
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 December 5, 2002 and granted November 13, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 5, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 5, 2024.
- 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.