Expired European patentEurope
1,6-diazaspiro (4,4)nonane-2,7-dione derivatives
EP 0336475 B1 · Applicant: SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.
Overview
The published document from the EPO: abstract, claims, description and drawings. Open it full size
Read the whole patent
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 March 21, 1989 and granted December 23, 1992. A European patent lasts at most 20 years from filing, so its term ended March 21, 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 September 21, 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.
FiledMarch 21, 1989
PublishedOctober 11, 1989
GrantedDecember 23, 1992
Term endedMarch 21, 2009
Application numberEP 89200725
Classification (CPC)C08G73/0672 +2 more
Timeline
Timeline From EPO dates
Sources & verification
Official EPO records
Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.