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Expired European patentEurope

Method for the preparation of silicas

EP 0372251 B1 · Applicant: Degussa 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 November 10, 1989 and granted March 11, 1992. A European patent lasts at most 20 years from filing, so its term ended November 10, 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 10, 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 10, 1989
PublishedJune 13, 1990
GrantedMarch 11, 1992
Term endedNovember 10, 2009
Application numberEP 89120839
Classification (CPC)C01B33/18

Timeline

Timeline From EPO dates

1990199219941996199820002002200420062008Application filedNov 10, 1989PublishedJune 13, 1990Patent grantedMarch 11, 1992Term endedNov 10, 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

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