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Expired Canadian patentCanada

Method for making absorbent starch

CA 2017676 C · Owner: Kimberly-Clark Corporation · Inventors: Gross, James R.; Greuel, Michael P.

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

A method for producing a water-swellable water-insoluble, carboxyalkyl starch. The steps of the method involving forming an aqueous dispersion of starch; adding to said aqueous dispersion carboxyalkylating reactants under conditions sufficient to form a water-soluble carboxyalkyl starch having an average degree of substitution between about 0.25 and 1.5; and recovering the carboxyalkyl starch by evaporative drying at a temperature within the range of from about 50°C to about 150°C.

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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 May 28, 1990 and granted November 7, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 28, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 28, 2012.
  • 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 28, 1990
GrantedNovember 7, 2000
Term endedMay 28, 2010
Patent numberCA 2017676 C
Classification (IPC)C08B31/12 +1 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedMay 28, 1990Patent grantedNov 7, 2000Term endedMay 28, 2010

Sources & verification

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