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Expired European patentEurope

Process for producing an acidic aqueous alumina sol

EP 0820961 B1 · Applicant: NISSAN CHEMICAL INDUSTRIES, LIMITED

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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 July 22, 1997 and granted June 12, 2002. A European patent lasts at most 20 years from filing, so its term ended July 22, 2017.
  • 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 22, 2023.
  • 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 22, 1997
PublishedJanuary 28, 1998
GrantedJune 12, 2002
Term endedJuly 22, 2017
Application numberEP 97810521
Classification (CPC)C01F7/02 +2 more

Timeline

Timeline From EPO dates

1998200020022004200620082010201220142016Application filedJuly 22, 1997PublishedJan 28, 1998Patent grantedJune 12, 2002Term endedJuly 22, 2017

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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