Patent Yard Sign in
Expired European patentEurope

Method of preparing catalysts for the gas phase oxidation of saturated and/or unsaturated C4-hydrocarbons to maleic anhydride

EP 0036623 B1 · Applicant: CHEMISCHE WERKE HÜLS AG

EPO PDF

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.

Google PatentsEPO PDF

Why it's free to use

  • Filed March 18, 1981 and granted September 21, 1983. A European patent lasts at most 20 years from filing, so its term ended March 18, 2001.
  • 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 18, 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.
FiledMarch 18, 1981
PublishedSeptember 30, 1981
GrantedSeptember 21, 1983
Term endedMarch 18, 2001
Application numberEP 81101996
Classification (CPC)B01J23/002 +2 more

Timeline

Timeline From EPO dates

1982198419861988199019921994199619982000Application filedMarch 18, 1981PublishedSep 30, 1981Patent grantedSep 21, 1983Term endedMarch 18, 2001

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

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.