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Expired Canadian patentCanada

Process for producing bisphenol a

CA 1306469 C · Owner: Kitamura, Takashi · Inventors: Iimuro, Shigeru; Morimoto, Yoshio; Kitamura, Takashi

CIPO record

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

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Abstract From the Canadian patent

In a process for producing bisphenol A by reacting phenol and acetone in the presence of hydrochloric acid as a catalyst, the improvement comprising adding the water-containing phenol separated from the reaction product mixture in the purification stage to the reaction mixture containing phenol and acetone, in such an amount that the water content in the reaction mixture is within the range of 1 to 5 wt%, said water-containing phenol being obtained from the dehydrochlorination step of the reaction product mixture, condensing the distilled off gases and liquid-separating of the condensates.

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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 August 18, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 18, 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.
FiledFebruary 9, 1989
GrantedAugust 18, 1992
Term endedAugust 18, 2009
Patent numberCA 1306469 C
Classification (IPC)C07C37/20 +1 more

Timeline

Timeline From CIPO dates

1990199219941996199820002002200420062008Application filedFeb 9, 1989Patent grantedAug 18, 1992Term endedAug 18, 2009

Sources & verification

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