Manufacture of 1,3-propanediol esters
CA 2309253 A1 · Owner: E.I. Du Pont De Nemours And Company · Inventors: Drysdale, Neville Everton; Adelman, Douglas J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
1,3-Propanediol esters, preferably diesters can be made using a modified , Prins reaction by reacting ethylene formaldehyde, and a carboxylic acid using a selected perfluoroalkylsulfonate or perfluorocarboxylate as a catalyst. Improved Prins reactions to make esters using formic acid as a carboxylic acid are also disclosed. The esters are useful as monomers and chemical intermediates.
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 December 3, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 3, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 3, 2020.
- 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.