Procedure for the preparation of dibasic acids from washings from the products of cyclohexane oxidation
CA 2222367 C · Owner: Rhone-Poulenc Fiber And Resin Intermediates · Inventors: Le Bris, Louis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention concerns a procedure for preparing dibasic acids or mixtures of dibasic acids from aqueous solutions produced by the washing of cyclohexane oxidation products. This procedure makes it possible to obtain adipic acid of sufficient purity to be used as an intermediate product in the synthesis of polyamide-6.6 for textile fibers as well as mixtures of good quality glutamic and succinic adipic acids. More precisely this invention involves a procedure for the preparation of aliphatic dibasic acids which involves the following steps: (a) at least partial deperoxidation of the washings by catalytic hydrogenation at a temperature between 0°C and 100 C° in the presence of at least one …
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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 December 11, 1997 and granted June 19, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 11, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 11, 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.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.