Continuous polyamide extraction process
CA 2310848 A1 · Owner: Hildenbrand, Peter · Inventors: Hildenbrand, Peter; Lang, Reinhard; Ludwig, Alfons
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is disclosed for continuously extracting polyamide particles from a circulating extraction solution in a vertical extraction column subdivided into two zones. The polyamide is treated in the first zone with an aqueous .epsilon.-caprolactam solution with 15-40 wt. % .epsilon.-caprolactam as extraction agent at 100 to 140 ~C, and water is then used in the second zone as extraction agent at a temperature 5-40 ~C lower. The process allows polyamides with a low monomer and oligomer content to be economically extracted.
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 November 24, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 24, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 24, 2020.
- 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.