Expired European patentEurope
Process for separating sulfonic acids from the reaction product obtained by the reaction of paraffins with sulfur dioxide, oxygen and water in the presence of UV-light
EP 0033775 B1 · Applicant: CHEMISCHE WERKE HÜLS AG
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.
Why it's free to use
- Filed December 5, 1980 and granted November 17, 1982. A European patent lasts at most 20 years from filing, so its term ended December 5, 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 June 5, 2006.
- 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.
FiledDecember 5, 1980
PublishedAugust 19, 1981
GrantedNovember 17, 1982
Term endedDecember 5, 2000
Application numberEP 80107658
Classification (CPC)C07C303/42
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.