Process for the recovery of adipic acid
CA 2062142 C · Owner: Bayer Aktiengesellschaft · Inventors: Steinhoff, Georg; Vogtel, Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a process for the recovery of adipic acid from mother liquors collected during commercial production of adipic acid, wherein said mother liquors contain from 52 to 60% by weight of nitric acid calculated as HNO3 not, taking into account the organic constituents from 2 to 6% by, weight of succinic acid from 4 to 9% by weight of glutaric, acid and from 5 to 10% by weight of adipic acid by selective, crystallization of the adipic acid dissolved in said mother liquors by, (a) adding an aqueous adipic acid solution having an adipic acid content of from 0.5 to 6% by weight to said mother liquor in the temperature range of from 30 to 60°C in such a quantity that the …
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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 March 2, 1992 and granted May 14, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 2, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 2, 2014.
- 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.