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Expired European patentEurope

Oxyalkylated quaternary ammonium compounds, their preparation and their use as drag reducing agents

EP 0146097 B1 · Applicant: HOECHST AKTIENGESELLSCHAFT

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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.

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Why it's free to use

  • Filed December 8, 1984 and granted June 8, 1988. A European patent lasts at most 20 years from filing, so its term ended December 8, 2004.
  • 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 8, 2010.
  • 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 8, 1984
PublishedJune 26, 1985
GrantedJune 8, 1988
Term endedDecember 8, 2004
Application numberEP 84114979
Classification (CPC)C07C65/21 +2 more

Timeline

Timeline From EPO dates

1985198719891991199319951997199920012003Application filedDec 8, 1984PublishedJune 26, 1985Patent grantedJune 8, 1988Term endedDec 8, 2004

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

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