Purification of 3,5-xylenol
CA 2067029 A1 · Owner: Davie, William R. · Inventors: Davie, William R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
15-, ABSTRACT OF THE DISCLOSURE, 3,5-xylenol is separated from mixtures containing isophorone sufficient to form an azeotrope with the 3,5-xylenol by distilling the mixtures in the presence of an amine of the formula NR1R2R3 where R1, R2 and R3 are independently selected from alkyl, alkanol and aryl groups having from two to six carbon atoms, said amine having an atmospheric boiling point above 230°C.
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 April 24, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 24, 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.