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Expired Canadian patentCanada

Use of trialkanolamine polyethers as demulsifiers for oil-in-water emulsions

CA 2035565 C · Owner: Elfers, Guenther · Inventors: Dix, Johannes P.; Sager, Wilfried; Fikentscher, Rolf

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

The present invention relates to the use of trialkanolamine polyethers obtained by condensation of one or more trialkanolamines in the presence of phosphorous acid and/or hypophosphorous acid as demulsifiers for oil-in-water emulsions.

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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 February 1, 1991 and granted December 5, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 1, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 1, 2013.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 1, 1991
GrantedDecember 5, 2000
Term endedFebruary 1, 2011
Patent numberCA 2035565 C
Classification (IPC)B01D17/05 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedFeb 1, 1991Patent grantedDec 5, 2000Term endedFeb 1, 2011

Sources & verification

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