Process and apparatus for producing terephthalic acid
CA 2118836 C · Owner: Yagi, Yasuhiko · Inventors: Yagi, Yasuhiko; Yamamoto, Ryoichi; Nakao, Fujimasa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process and an apparatus for producing terephthalic acid economically by oxidizing paraxylene supplied to an oxidizing reactor connected with a compactly designed distillation column in an acetic acid-based solvent, while effecting the distillatory recovery of the paraxylene and acetic acid efficiently without suffering from stuffing of the distillation column, which process comprises, supplying paraxylene and a molecular oxygen-containing gas to the oxidizing reactor connected to a distillation column having at the lower part thereof a solid matter collecting tray consisting of a perforated ripple plate and, above it, a packed bed and further above it, a liquid distribution tray, in …
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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 11, 1994 and granted October 5, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 11, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 11, 2016.
- 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.