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Expired European patentEurope

Improved process for producing 4-hydroxy-2-pyrrolidone

EP 0829472 B1 · Applicant: DAISO CO., LTD.

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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 May 14, 1996 and granted August 21, 2002. A European patent lasts at most 20 years from filing, so its term ended May 14, 2016.
  • 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 November 14, 2021.
  • 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.
FiledMay 14, 1996
PublishedMarch 18, 1998
GrantedAugust 21, 2002
Term endedMay 14, 2016
Application numberEP 96913738
Classification (CPC)C07D207/273

Timeline

Timeline From EPO dates

1997199920012003200520072009201120132015Application filedMay 14, 1996PublishedMarch 18, 1998Patent grantedAug 21, 2002Term endedMay 14, 2016

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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