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Expired Canadian patentCanada

Method of producing ethylene-vinyl alcohol copolymer film

CA 1137726 A · Owner: Kuraray Co. Ltd. · Inventors: Ikari, Kyoichiro; Miyake, Shunji; Kodera, Yuji

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Abstract From the Canadian patent

Abstract of the Disclosure, A method of producing films of ethylene-vinyl alcohol copolymers having an ethylene content of 20-55 mole % and a saponification degree of not less than 96% is provided which is characterized in that biaxial or multiaxial stretching at a low moisture content and at low temperatures, previously thought difficult, is made possible by using unstretched films which are especially low in the degree of crystallinity. The degree of crystallinity of the unstretched film is represented by the density at 25°C thereof and when the ethylene content is X mole % a film, having a lower density value than the value calculated by the formula, 1.320 - 4.3 x 10-3 X ( g/ml ) is …

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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 December 21, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 21, 1999.
  • 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 18, 1979
GrantedDecember 21, 1982
Term endedDecember 21, 1999
Patent numberCA 1137726 A
Classification (IPC)B29C55/00

Timeline

Timeline From CIPO dates

1980198219841986198819901992199419961998Application filedDec 18, 1979Patent grantedDec 21, 1982Term endedDec 21, 1999

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