Peroxide process for producing n-phosphonomethylglycine
CA 2034882 C · Owner: Fields, Donald Lee Jr. · Inventors: Fields, Donald Lee Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is provided for producing N-phosphonomethylglycine by the oxidation of N-phosphonomethyliminodiacetic acid with a peroxide to form an intermediate N-phosphonomethyliminodiacetic acid-Noxide. Thereafter, the N-phosphonomethyliminodiacetic acid-N-oxide is converted to N-phosphonomethylglycine by adding a catalytic amount of a metal selected from the group consisting of iron, zinc, aluminum vanadium, and copper, or a compound selected from the group consisting of water-soluble vanadium compounds ferrous salts and cuprous salts.
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 January 24, 1991 and granted July 2, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 24, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 24, 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.