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Expired Canadian patentCanada

N-methyl-2-pyrrolidone compositions

CA 1308341 C · Owner: Colegrove, George T. · Inventors: Colegrove, George T.

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

Viscous solutions of NMP are described which comprise up to about 90% NMP. The viscosifying agent is rhamsan gum.

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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 October 6, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 6, 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.
FiledApril 12, 1988
GrantedOctober 6, 1992
Term endedOctober 6, 2009
Patent numberCA 1308341 C
Classification (IPC)C09D9/00 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedApril 12, 1988Patent grantedOct 6, 1992Term endedOct 6, 2009

Sources & verification

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