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Expired European patentEurope

Process for separating highly pure butene-1 and butene-2

EP 0079679 B1 · Applicant: NIPPON ZEON CO., LTD.

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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 October 12, 1982 and granted September 24, 1986. A European patent lasts at most 20 years from filing, so its term ended October 12, 2002.
  • 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 April 12, 2008.
  • 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.
FiledOctober 12, 1982
PublishedMay 25, 1983
GrantedSeptember 24, 1986
Term endedOctober 12, 2002
Application numberEP 82305429
Classification (CPC)C07C7/005 +2 more

Timeline

Timeline From EPO dates

1983198519871989199119931995199719992001Application filedOct 12, 1982PublishedMay 25, 1983Patent grantedSep 24, 1986Term endedOct 12, 2002

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.