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Expired Canadian patentCanada

Method for maintaining the activity of zeolite catalysts

CA 1332933 C · Owner: Nitto Kagaku Kogyo Kabushiki Kaisha · Inventors: Fujita, Takeyuki; Inagaki, Takeshi; Nikaido, Yuko

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

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Abstract From the Canadian patent

There is provided a method for maintaining the activity of a zeolite catalyst in the catalytic production of methylamines from methanol and ammonia using a zeolite catalyst as at least one of catalysts applied, which comprises controlling the amount of aldehyde compounds as impurities flowing into a zeolite catalyst layer to about 0.15 g/hr.kg-cat. or lower as, calculated in terms of 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 November 8, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 8, 2011.
  • 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 18, 1989
GrantedNovember 8, 1994
Term endedNovember 8, 2011
Patent numberCA 1332933 C
Classification (IPC)B01J29/08 +2 more

Timeline

Timeline From CIPO dates

19901993199619992002200520082011Application filedMay 18, 1989Patent grantedNov 8, 1994Term endedNov 8, 2011

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