Process for cleaning or purifying aqueous n-methylmorpholine-n-oxide solutions
CA 2056137 C · Owner: Zikeli, Stefan · Inventors: Zikeli, Stefan; Eichinger, Dieter; Manner, Johann
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An aqueous N-methylmorpholine-N-oxide solution which was used as a spinning bath in the production of cellulosic products is regenerated by contacting it with active coal silica dioxide or, alumina adsorbent and filtering thereby reducing turbidity, eliminating nitrosoamine decolorizing the solution and removing transition metals like iron therefrom.
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 25, 1991 and granted October 2, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 25, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 25, 2013.
- 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.