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Expired Canadian patentCanada

Differentially cross-linked multilayer film

CA 2018807 C · Owner: Union Carbide Corporation · Inventors: Nelson, John Gordon; Evert, Charles Peter

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 tubular article formed of multilayer differentially cross-linked heat sealable film suitable for the manufacture of bags used in the packaging of meats. The multilayer film contains at least two layers the inner of which is a heat sealable layer containing an antioxidant cross-linking inhibitor in an amount sufficient to inhibit the cross-linking of that layer by irradiation. Accordingly, upon exposure of the multilayer film to radiation, the outer layer will be cross-linked to a greater extent than the first heat sealable layer.

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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 June 12, 1990 and granted December 14, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 12, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 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.
FiledJune 12, 1990
GrantedDecember 14, 1993
Term endedJune 12, 2010
Patent numberCA 2018807 C
Classification (IPC)B29C49/08 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJune 12, 1990Patent grantedDec 14, 1993Term endedJune 12, 2010

Sources & verification

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