Patent Yard Sign in
Expired European patentEurope

Water-soluble azo compounds, process for their preparation and their use as dyestuffs

EP 0043575 B1 · Applicant: HOECHST AKTIENGESELLSCHAFT

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 July 4, 1981 and granted January 25, 1984. A European patent lasts at most 20 years from filing, so its term ended July 4, 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 January 4, 2007.
  • 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 4, 1981
PublishedJanuary 13, 1982
GrantedJanuary 25, 1984
Term endedJuly 4, 2001
Application numberEP 81105200
Classification (CPC)C09B62/507

Timeline

Timeline From EPO dates

1982198419861988199019921994199619982000Application filedJuly 4, 1981PublishedJan 13, 1982Patent grantedJan 25, 1984Term endedJuly 4, 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.