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Expired Canadian patentCanada

Light stabilizer comprised of aryl nitrogen compound and uses thereof

CA 2016195 C · Owner: Takagisi, Yosikazu · Inventors: Hamada, Emiko; Ootaguro, Kunihiko; Takagisi, Yosikazu

CIPO record

Overview

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

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Abstract From the Canadian patent

Certain types of aryl nitrogen compound are found to be useful not only for effectively rendering dyes lightfast but also for using as an additive that has high solubility in solvents and sufficiently good miscibility with dyes to insure that their solubility will not be impaired. They can be used for preventing various reactions that cause deterioration by light in organic dyes, in particular cyanine dyes. They can also be used for improving the keeping quality and recording and reproduction characteristics of optical recording media that use organic dyes in the form of thin films. Representative examples include N, N-lower alkyl substituted nitroso-anilines phenol or naphthol derivatives …

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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 May 7, 1990 and granted April 28, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 7, 1990
GrantedApril 28, 1998
Term endedMay 7, 2010
Patent numberCA 2016195 C
Classification (IPC)C07C207/04 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedMay 7, 1990Patent grantedApril 28, 1998Term endedMay 7, 2010

Sources & verification

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