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US3671248A Expired / Lapsed US ⏱️ 0.0 years remaining

Stain inhibitor in photographic paper bases

Assignee: Eastman Kodak Co
•
Filing: 1970-06-10
•
Granted: 1972-06-20
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Expires: 1990-06-10
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Abstract

Abstract PHOTOGRAPHIC ELEMENTS HAVING POLYOLEFIN COATED PAPER SUPPORTS, PROVIDED WITH SILVER HALIDE EMULSION LAYERS CONTAINING SILVER HALIDE DEVELOPING AGENTS, WITH OR WITHOUT HYDROPHILIC BACKING LAYERS, EXHIBIT STAIN DUE TO MIGRATION OF THE DEVELOPING AGENT TO PAPER AND TO THE BACKING LAYER. STAIN IS AVOIDED BY SIZING THE PAPER WITH AN ALDEHYDE BISULFITE AND COATING ANY BACKING LAYER AT A PH LESS THEN 7 PREFERABLY ABOUT 3 TO 4.

Inventors

  • 👤 Merle K Eldridge
  • 👤 Roy C Bloom
  • 👤 Douglas C Joseph

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 00:22
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/42; G03C1/76; G03C1/775; G03C1/79

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-06-20 1975-12-20 1976-06-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-06-20 1979-12-20 1980-06-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-06-20 1983-12-20 1984-06-20 $7700.00 Window Closed / Lapsed

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