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Expired Canadian patentCanada

Microcapsules and microencapsulation process

CA 2101641 C · Owner: Zeneca Inc. · Inventors: Rodson, Marius; Scher, Herbert Benson

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

Microcapsules containing a substantially water-insoluble liquid material such , as an anilide herbicide, and optionally also a herbicide antidote, within a porous shell to effect a scow rate of release of said herbicide (and optionally said antidote) through said shell, are produced by a process which comprises (a) providing an organic solution comprising said material and an etherified amino resin prepolymer dissolved therein which from about 50 % to about 98 % of the methylol groups of said prepolymer have been etherified with a C4-C10 alcohol; (b) creating an emulsion of said organic solution in a continuous phase aqueous solution comprising water and a surface-active agent wherein …

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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 December 12, 1991 and granted February 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 12, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 12, 2013.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 12, 1991
GrantedFebruary 6, 2001
Term endedDecember 12, 2011
Patent numberCA 2101641 C
Classification (IPC)A01N25/28 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedDec 12, 1991Patent grantedFeb 6, 2001Term endedDec 12, 2011

Sources & verification

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