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US3769206A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for eliminating color developer fog

Assignee: Eastman Kodak Co
•
Filing: 1972-01-05
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Granted: 1973-10-30
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Expires: 1992-01-05
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Abstract

Abstract IT HAS BEEN DISCOVERED THAT FOG INDUCED BY COLOR DEVELOPER SOLUTIONS WHICH INCLUDE A SULFITE ION ANTIOXIDANT, A HYDROXYLAMINE STABILIZER AND A SALT OF AN AMINO POLYCARBOXYLIC ACID AS A HEAVY METAL SEQUESTERING AGENT CAN BE ELIMINATED BY TREATING THE COLOR DEVELOPER SOLUTION WITH AN AMMONIA SCAVENGER FOR EXAMPLE, A BIOLOGICAL SCAVENGER SUCH AS AN ENZYME AND PARTICULARLY CARBAMOYL PHOSPHATE SYNTHETASE AND TRANSAMMINASE ENZYMES FOUND IN ACTIVATED YEAST, OR A CHEMICAL SCAVENGER SUCH AS BORIC ACID OR ACETALDEHYDE, PROTECTED BY A MEMBRANE SELECTIVELY PERMEABLE TO AMMONIA AND STABLE AT PHS ABOVE ABOUT 8.0. THE TECHNIQUE DESCRIBED HEREIN IS EQUALLY EFFECTIVE FOR DEAMMONIATING OTHER AQUEOUS ALKALINE AMMONIACAL SOLUTIONS.

Inventors

  • 👤 J Brown
  • 👤 L Hotter

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 12:27
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/31; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903

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) 1976-10-29 1977-04-30 1977-10-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-10-29 1981-04-30 1981-10-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-10-29 1985-04-30 1985-10-30 $7700.00 Window Closed / Lapsed

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