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Expired European patentEurope

Process for the delignification and bleaching of cellulose pulps

EP 0171575 B1 · Applicant: Degussa Aktiengesellschaft

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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 July 3, 1985 and granted November 29, 1989. A European patent lasts at most 20 years from filing, so its term ended July 3, 2005.
  • 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 January 3, 2011.
  • 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.
FiledJuly 3, 1985
PublishedFebruary 19, 1986
GrantedNovember 29, 1989
Term endedJuly 3, 2005
Application numberEP 85108213
Classification (CPC)D21C9/10

Timeline

Timeline From EPO dates

1986198819901992199419961998200020022004Application filedJuly 3, 1985PublishedFeb 19, 1986Patent grantedNov 29, 1989Term endedJuly 3, 2005

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