Process for producing highly pure phenol
CA 2093284 A1 · Owner: Shirahata, Tatsuo · Inventors: Imamura, Tetsuo; Shirahata, Tatsuo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing a highly pure phenol in which a crude phenol obtained from an aciddecomposition product of cumene hydroperoxide and having an .alpha.-methylstyrene content of 15 % by weight or less is catalytically treated with an acidic ? -alumina catalyst having a specific surface area of 80 to 400 m2/g and an acid strength, according to Hammett's acidity function (Ho), of 3?Ho?6.8 to convert aliphatic and aromatic carbonyl compounds contained in the crude phenol into high-boiling compounds without causing the substantial formation of a dimer of .alpha.methylstyrene contained in the crude phenol and then, a phenol and the so-formed high-boiling compounds were separated by …
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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 April 2, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 2, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 2, 2015.
- 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.