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Expired European patentEurope

Silicon nitride type sintered body and process for its production

EP 0377758 B1 · Applicant: NIPPON TUNGSTEN CO., LTD.

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Overview

The published document from the EPO: abstract, claims, description and drawings. Open it full size

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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.

Why it's free to use

  • Filed July 7, 1989 and granted October 5, 1994. A European patent lasts at most 20 years from filing, so its term ended July 7, 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 January 7, 2015.
  • 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.
FiledJuly 7, 1989
PublishedJuly 18, 1990
GrantedOctober 5, 1994
Term endedJuly 7, 2009
Application numberEP 89908262
Classification (CPC)C04B35/593

Timeline

Timeline From EPO dates

1990199219941996199820002002200420062008Application filedJuly 7, 1989PublishedJuly 18, 1990Patent grantedOct 5, 1994Term endedJuly 7, 2009

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