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Expired Canadian patentCanada

Vermiculite dispersions and method of preparing same

CA 1329454 C · Owner: W.R. Grace & Co.-Conn. · Inventors: Ou, Chia-Chih; Yang, Julie C.

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Abstract From the Canadian patent

Stable vermiculite dispersions which are substantially free of settling and a method of preparing same are provided. The dispersions are obtained by treating the vermiculite platelets of which the dispersion is comprised with an anionic chelating agent. The anionic chelating agent enhances the rate and degree of swelling of the vermiculite in an aqueous medium. The swollen vermiculite is delaminated by shearing to provide the inventive dispersions.

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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 May 17, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 17, 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.
FiledJune 19, 1989
GrantedMay 17, 1994
Term endedMay 17, 2011
Patent numberCA 1329454 C
Classification (IPC)C04B14/20 +1 more

Timeline

Timeline From CIPO dates

19901993199619992002200520082011Application filedJune 19, 1989Patent grantedMay 17, 1994Term endedMay 17, 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.