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Expired Canadian patentCanada

Process for purifying propanediol-1,3

CA 1297912 C · Owner: Dambkes, Georg · Inventors: Dambkes, Georg; Breitkopf, Norbert; Bach, Hanswilhelm

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Overview

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Abstract From the Canadian patent

of Disclosure, A process for the purification of propanediol-1,3, especially when produced by hydration of acrolein with water, including extracting the diol with cyclohexane. Preferably, from 2 to 10 parts by weight of cyclohexane per part by weight of diol is used. The purification is usually carried out below 60°C.

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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 March 24, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 24, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 24, 1987
GrantedMarch 24, 1992
Term endedMarch 24, 2009
Patent numberCA 1297912 C
Classification (IPC)C07C29/86 +1 more

Timeline

Timeline From CIPO dates

19881991199419972000200320062009Application filedSep 24, 1987Patent grantedMarch 24, 1992Term endedMarch 24, 2009

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.