Process for the production of polyamine mixtures of the poly-amino-polyaryl-polymethylene series
CA 2095188 C · Owner: Konig, Christian · Inventors: Konig, Christian; Richter, Franz-Moritz; Uchdorf, Rudolf
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for production of polyamines of the diphenylmethane series through a condensation reaction of aniline with formaldehyde in the presence of an acid catalyst neutralization of the acid catalyst after reaction completion and distillation of the resultant polyamine mixture is described. The key feature of the process is the abrupt increase in reaction temperature after the condensation reaction or after the first rearrangement step.
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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 April 29, 1993 and granted April 15, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 29, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 29, 2015.
- 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
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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.