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Expired Canadian patentCanada

Process for the preparation of solutions of cellulose derivatives which can be coagulated and spun to form regenerated cellulose bodies

CA 1110009 A · Owner: Snia Viscosa Societa Nazionale Industria Applicazioni Viscosa S.P.A. · Inventors: Baldini, Alberto; Leoni, Roberto; Angelini, Gianfranco

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Abstract From the Canadian patent

A process for the preparation of solutions of cellulose dericatives from which formed bodies, such as fibres or films of, regenerated cellulose can be obtained by coagulation and regeneration, e.g. by wet spinning, is disclosed. The cellulose is transformed into a methylol derivative containing more than 2 units of formaldehyde per anydroglucosidic unit which derivative, is soluble in organic solvents of the class consisting of polar aprotic solvents constituted by N-substituted amides pyridine and formamide. The methylol derivative is prepared by treating cellulose with paraformaldehyde and dimethylsulphoxide. The methylol derivative is then dissolved in one of the aforesaid solvents, …

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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 October 6, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 6, 1998.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 23, 1979
GrantedOctober 6, 1981
Term endedOctober 6, 1998
Patent numberCA 1110009 A
Classification (IPC)C08L1/28 +2 more

Timeline

Timeline From CIPO dates

1980198219841986198819901992199419961998Application filedFeb 23, 1979Patent grantedOct 6, 1981Term endedOct 6, 1998

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