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Expired Canadian patentCanada

Electroviscous fluid

CA 2000322 C · Owner: Osaki, Toshiyuki · Inventors: Osaki, Toshiyuki; Endo, Shigeki; Ishino, Yuichi

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

The electroviscous fluid is a suspension composed of a finely divided dielectric solid dispersed in an electrically nonconductive oil. The viscosity of the fluid increases swiftly and reversibly under an influence of electric field applied thereto and the fluid turns to a state of plastic or solid when the influence is sufficiently strong. The electroviscous fluid of the present invention comprises 1-60% by weight of a dispersed phase of carbonaceous particulates having average particle size of 0.01-100 micrometer, and 99-40% by weight of a continuous liquid phase of an electric insulating oil having a viscosity of 0.65-500 centistokes at room temperature. The electroviscous fluid exhibits …

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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 October 6, 1989 and granted August 19, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 6, 2009.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 6, 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.
FiledOctober 6, 1989
GrantedAugust 19, 1997
Term endedOctober 6, 2009
Patent numberCA 2000322 C
Classification (IPC)C10M171/00 +2 more

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