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Color improvement of unsized porous paper

US 2,730,446 A · Inventors: CLAIR HUTCHINS MARSDEN

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Listed from its USPTO record in Patent Yard's full-term archive. Its claims, description and drawings are in the USPTO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Granted January 10, 1956. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by January 10, 1973.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledMarch 15, 1952
GrantedJanuary 10, 1956
Term endedJanuary 10, 1973
Application number—
Classification (CPC)D21H21/28 +1 more
Length11 pages

Timeline

Timeline From USPTO dates

1953195619591962196519681971Application filedMarch 15, 1952Patent grantedJan 10, 1956Term endedJan 10, 1973

Sources & verification

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

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comJustia PatentsFull text, claims and classification.patents.justia.comFreePatentsOnlineFull text and PDF.freepatentsonline.comEspacenetForeign family and legal status.European Patent Office

Everything on this page comes from the USPTO record linked above.