Expired European patentEurope
Process for the recovery of 2-hydroxynaphthaline-3-carboxylic acid from the reaction products of the alkali metal salts obtained from 2-hydroxynaphthaline with carbon dioxide
EP 0017771 B1 · Applicant: HOECHST AKTIENGESELLSCHAFT
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 17, 1980 and granted September 23, 1981. A European patent lasts at most 20 years from filing, so its term ended March 17, 2000.
- 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 17, 2005.
- 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 17, 1980
PublishedOctober 29, 1980
GrantedSeptember 23, 1981
Term endedMarch 17, 2000
Application numberEP 80101391
Classification (CPC)C07C51/47
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.