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Expired European patentEurope

Water soluble azo compounds, process for their preparation and their use as dyestuffs

EP 0283900 B1 · Applicant: HOECHST 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.

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Why it's free to use

  • Filed March 15, 1988 and granted April 10, 1991. A European patent lasts at most 20 years from filing, so its term ended March 15, 2008.
  • 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 September 15, 2013.
  • 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.
FiledMarch 15, 1988
PublishedSeptember 28, 1988
GrantedApril 10, 1991
Term endedMarch 15, 2008
Application numberEP 88104058
Classification (CPC)C09B62/51

Timeline

Timeline From EPO dates

1989199119931995199719992001200320052007Application filedMarch 15, 1988PublishedSep 28, 1988Patent grantedApril 10, 1991Term endedMarch 15, 2008

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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