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Filtering oil solution of calcium sulfonate using a synthetic polyelectrolyte

US 2,885,357 A · Inventors: ARCHIBALD FRANCIS M et al.

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  • Granted May 5, 1959. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by May 5, 1976.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledOctober 19, 1954
GrantedMay 5, 1959
Term endedMay 5, 1976
Application number—
Classification (CPC)B01D37/03 +1 more
Length3 pages

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Official USPTO records

Full published documentText and every drawing sheet as a PDF.USPTOFile historyStatus, office actions, notices, fee records and petitions.USPTO Patent CenterPatent Public Search recordSearchable full text and bibliographic data.USPTO

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