Process for selective production of 2- hydroxynaphthalene-6-carboxylic acid
CA 1190245 A · Owner: Kabushiki Kaisha Ueno Seiyaku Oyo Kenkyujo · Inventors: Sakota, Kazuyuki; Ueno, Ryuzo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the selective production of 2hydroxynaphthalene-6-carboxylic acid, which comprises continuously reacting potassium .beta.-naphtlolate with carbon dioxide at a reaction temperature in the range of 230 to 350°C and under a carbon dioxide pressure suitable for the reaction temperature and selected within the range of 1 to 20 kg/cm2(G) while removing the by-product .beta.-naphthol by using a reaction medium having a specific gravity of 0.6 to 1.5 and being capable of dissolving .beta.-naphthol but substantially incapable of dissolving potassium .beta.-naphtholate.
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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
- Granted July 9, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 9, 2002.
- 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.