Recovery of caprolactam from oligomers and/or polymers of caprolactam
CA 2096712 C · Owner: Brunner, Erwin · Inventors: Neubauer, Gerald; Kopietz, Michael; Priester, Claus-Ulrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for recovering, caprolactam from oligomers and/or polymers of caprolactam comprises the following steps:, a) treating oligomers and/or polymers of caprolactam with from 1 to 20 parts by weight of water per part by weight of oligomer or polymer at from 200 to 350°C under superatmospheric pressure with a residence time of from 0.5 to 10 hours to form an aqueous reaction mixture comprising polycaprolactam monomeric caprolactam and oligomers thereof and, b) passing the aqueous reaction mixture obtained in a) into a fluidized bed of alumina at from 250 to 400°C to obtain a mixture of steam and caprolactam.
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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 May 20, 1993 and granted September 9, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 20, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 20, 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
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.