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Expired Canadian patentCanada

Brine treatment using ethylene/carboxylic acid polymers

CA 1284844 C · Owner: Spradling, Robert D. · Inventors: Spradling, Robert D.; Burney, Harry S.; Vaughn, Walter Lee

CIPO record

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Abstract From the Canadian patent

Hardness values (Ca++ and Mg++) and other polyvalent metal cations are removed from alkali metal brines (esp. NaC1) by using a high surface area ethyl_ ene/carboxylic acid polymer (esp. porous ethylene/ acrylic acid copolymers).

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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 June 11, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 11, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 3, 1986
GrantedJune 11, 1991
Term endedJune 11, 2008
Patent numberCA 1284844 C
Classification (IPC)B01J47/12 +2 more

Timeline

Timeline From CIPO dates

19871990199319961999200220052008Application filedSep 3, 1986Patent grantedJune 11, 1991Term endedJune 11, 2008

Sources & verification

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