Method for the production of cellulose carbamate by means of reactive extrusion
CA 2493845 A1 · Owner: Weigel, Peter · Inventors: Loth, Fritz; Weigel, Peter; Fink, Hans-Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method for the production of cellulose carbamate by reactive extrusion and for the production of moulded bodies from regenerated cellulose. The method for the production of cellulose carbamate is based on the activation of cellulose, subsequent separation of the activation solution followed by reactive extrusion of the activated cellulose. Typical examples of the moulded bodies produced therefrom are fibres films, beads, sponges or , sponge-type cloths.
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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 9, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 9, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 9, 2025.
- 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.