Process for preparing caprolactam from 6-aminocapronitrile
CA 2260805 A1 · Owner: Voit, Guido · Inventors: Fischer, Rolf; Voit, Guido; Ritz, Josef
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention concerns the preparation of caprolactam by cyclizing 6aminocapronitrile in the presence of water at high temperature and optionally of a catalyst and a solvent by: a) separating from the reaction yield ("reaction yield I") of the cyclizing process caprolactam and all the components boiling higher than caprolactam ("high boilers"); b) treating the high boilers from step a) with phosphoric acid and/or polyphosphoric acid at a temperature ranging from 200 to 350 ~C obtaining reaction yield II; and c) , separating the caprolactam resulting from reaction yield II of step b) and optionally 6-aminocapronitrile from unreacted "high boilers" and the acid used.
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 July 7, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 7, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 7, 2019.
- 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.