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Expired European patentEurope

Optically active 1-acyl-proline esters and their use as doping agents in liquid-crystal compositions

EP 0275522 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 December 21, 1987 and granted March 29, 1995. A European patent lasts at most 20 years from filing, so its term ended December 21, 2007.
  • 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 21, 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.
FiledDecember 21, 1987
PublishedJuly 27, 1988
GrantedMarch 29, 1995
Term endedDecember 21, 2007
Application numberEP 87118930
Classification (CPC)C07D403/12 +2 more

Timeline

Timeline From EPO dates

1988199019921994199619982000200220042006Application filedDec 21, 1987PublishedJuly 27, 1988Patent grantedMarch 29, 1995Term endedDec 21, 2007

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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