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Expired Canadian patentCanada

Blocked isocyanate

CA 1187491 A · Owner: American Cyanamid Company · Inventors: Novak, Robert W.; Singh, Balwant

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 novel compound, N,N'-methylenebis, (hexahydro-2-oxo-1H-azepine-1-carboxamide) which is useful as a blocked isocyanate to introduce the functionality of methylene diisocyanate and which is prepared by the reaction of isocyanic acid and caprolactam followed by reaction with formaldehyde.

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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 May 21, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 21, 2002.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 4, 1983
GrantedMay 21, 1985
Term endedMay 21, 2002
Patent numberCA 1187491 A
Classification (IPC)C07D223/10 +1 more

Timeline

Timeline From CIPO dates

1984198619881990199219941996199820002002Application filedMarch 4, 1983Patent grantedMay 21, 1985Term endedMay 21, 2002

Sources & verification

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