Patent Yard Sign in
Expired European patentEurope

Process for the interconversion of two separate crystal forms of a herbicidal pyridine sulfonamide

EP 0444101 B1 · Applicant: E.I. DU PONT DE NEMOURS AND COMPANY

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 November 17, 1989 and granted September 18, 1996. A European patent lasts at most 20 years from filing, so its term ended November 17, 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 May 17, 2015.
  • 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.
FiledNovember 17, 1989
PublishedSeptember 4, 1991
GrantedSeptember 18, 1996
Term endedNovember 17, 2009
Application numberEP 89913041
Classification (CPC)C07D521/00 +1 more

Timeline

Timeline From EPO dates

1990199219941996199820002002200420062008Application filedNov 17, 1989PublishedSep 4, 1991Patent grantedSep 18, 1996Term endedNov 17, 2009

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.