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Expired European patentEurope

Superabsorbent crosslinked ampholytic ion pair copolymers

EP 0487975 B1 · Applicant: PHILLIPS PETROLEUM COMPANY

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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 13, 1991 and granted February 28, 1996. A European patent lasts at most 20 years from filing, so its term ended November 13, 2011.
  • 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 13, 2017.
  • 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 13, 1991
PublishedJune 3, 1992
GrantedFebruary 28, 1996
Term endedNovember 13, 2011
Application numberEP 91119341
Classification (CPC)C08F228/02 +2 more

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedNov 13, 1991PublishedJune 3, 1992Patent grantedFeb 28, 1996Term endedNov 13, 2011

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.