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Expired European patentEurope

Use of particles comprising alpha-iron in alkali metal halide electrolysis, cathodes for such use and process for their preparation, electrolytic cell and method of operating same

EP 0035837 B1 · Applicant: E.I. DU PONT DE NEMOURS AND COMPANY

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Overview

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed February 20, 1981 and granted July 4, 1984. A European patent lasts at most 20 years from filing, so its term ended February 20, 2001.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by August 20, 2006.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledFebruary 20, 1981
PublishedSeptember 16, 1981
GrantedJuly 4, 1984
Term endedFebruary 20, 2001
Application numberEP 81300730
Classification (CPC)C25B1/46 +1 more

Timeline

Timeline From EPO dates

1982198419861988199019921994199619982000Application filedFeb 20, 1981PublishedSep 16, 1981Patent grantedJuly 4, 1984Term endedFeb 20, 2001

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