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Expired European patentEurope

1,8-Naphthyridin-2-one derivatives

EP 0452873 B1 · Applicant: KYOWA HAKKO KOGYO CO., LTD.

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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.

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Why it's free to use

  • Filed April 16, 1991 and granted July 3, 1996. A European patent lasts at most 20 years from filing, so its term ended April 16, 2011.
  • 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 October 16, 2016.
  • 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.
FiledApril 16, 1991
PublishedOctober 23, 1991
GrantedJuly 3, 1996
Term endedApril 16, 2011
Application numberEP 91106040
Classification (CPC)A61P37/00 +2 more

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedApril 16, 1991PublishedOct 23, 1991Patent grantedJuly 3, 1996Term endedApril 16, 2011

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

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