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Expired European patentEurope

Method for plugging lost circulation areas

EP 0343689 B1 · Applicant: TOHO KAGAKU KOGYO 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 May 29, 1989 and granted February 3, 1993. A European patent lasts at most 20 years from filing, so its term ended May 29, 2009.
  • 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 29, 2014.
  • 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 29, 1989
PublishedNovember 29, 1989
GrantedFebruary 3, 1993
Term endedMay 29, 2009
Application numberEP 89109653
Classification (CPC)C09K8/502 +1 more

Timeline

Timeline From EPO dates

1990199219941996199820002002200420062008Application filedMay 29, 1989PublishedNov 29, 1989Patent grantedFeb 3, 1993Term endedMay 29, 2009

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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