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Aromatic polyimides derived from aromatic dianhydrides and chlorinated aromatic diamines

EP 0491306 A1 · Applicant: E.I. DU PONT DE NEMOURS AND COMPANY

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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 December 14, 1991 and never granted as a European patent. Had it been granted, its 20-year term would have ended December 14, 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 June 14, 2017.
  • 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.
FiledDecember 14, 1991
PublishedJune 24, 1992
GrantedNever granted
Term endedDecember 14, 2011
Application numberEP 91121485
Classification (CPC)C08G73/1067 +1 more

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedDec 14, 1991PublishedJune 24, 1992Term endedDec 14, 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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