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Expired European patentEurope

Method of preparing diacetoketogulonic acid

EP 0040331 B1 · Applicant: MERCK PATENT GmbH

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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 22, 1981 and granted April 4, 1984. A European patent lasts at most 20 years from filing, so its term ended April 22, 2001.
  • 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 22, 2006.
  • 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 22, 1981
PublishedNovember 25, 1981
GrantedApril 4, 1984
Term endedApril 22, 2001
Application numberEP 81103028
Classification (CPC)C25B3/23 +2 more

Timeline

Timeline From EPO dates

1982198419861988199019921994199619982000Application filedApril 22, 1981PublishedNov 25, 1981Patent grantedApril 4, 1984Term endedApril 22, 2001

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

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.