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Expired Canadian patentCanada

Process for preparing epoxy resins containing triazine groups

CA 1259992 A · Owner: The Dow Chemical Company · Inventors: Hefner, Robert E. Jr.

CIPO record

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Abstract From the Canadian patent

This invention pertains to a process for preparing hydroxyaromatic oligomers containing triazine groups. The process is characterized by (I) reacting (A) a material having an average of more than one aromatic hydroxyl group per molecule such as bisphenol A with (B) a cyanogen halide such as cyanogen bromide in the presence of (C) a base and recovering a mixture of cyanate-containing products and unreacted (A) materials; (II) trimerizing the product recovered in (I) in the presence of a trimerization catalyst such as cobalt naphthenate. This invention also pertains to a process for epoxidizing the product from step II by reaction with an epihalohydrin such as epichlorohydrin dehydro-, …

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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 September 26, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 26, 2006.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 26, 1984
GrantedSeptember 26, 1989
Term endedSeptember 26, 2006
Patent numberCA 1259992 A
Classification (IPC)C07D251/34 +2 more

Timeline

Timeline From CIPO dates

19851988199119941997200020032006Application filedOct 26, 1984Patent grantedSep 26, 1989Term endedSep 26, 2006

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