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US3749574A Expired / Lapsed US ⏱️ 0.0 years remaining

Development of photographic silver halide elements

Assignee: Agfa Gevaert NV
•
Filing: 1971-05-17
•
Granted: 1973-07-31
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Expires: 1991-05-17
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Abstract

Abstract A PROCESS IS DESCRIBED FOR DEVELOPING AN EXPOSED PHOTOGRAPHIC SILVER HALIDE ELEMENT WHEREIN THE DEVELOPMENT IS CARRIED OUT IN THE PRESENCE OF A WATER-SOLUBLE NONPOLYMERIC COMPOUND OBTAINED BY REACTION OF A BISEPOXIDE OF THE FORMULA: (-O-CH2-)>CH-CH2-Z-CH2-CH<(-O-CH2-) Z BEING OXYGEN OR THE GROUP -O-Y-O- WHEREIN Y IS A STRAIGHT-CHAIN OR BRANCHED-CHAIN C2-C8 ALKYLENE GROUP WITH A MONOALKYL OR MONOARYL ETHER OF ETHYLENE GLYCOL OR A POLYOXYETHYLENE GLYCOL. THE SPEED AND DEVELOPABILITY OF THE SILVER HALIDE ELEMENT IS SUBSTANTIALLY INCREASED BY THE PRESENCE OF THIS POLYADDITION COMPOUND. BY INFECTIOUS DEVELOPMENT OF SILVER CHLORIDE AND SILVER CHLOROBROMIDE EMULSIONS IT IS POSSIBLE BY MEANS OF THESE COMPOUNDS TO OBTAIN VERY CONTRASTY LINE AND SCREEN IMAGES AND SHARPLY DEFINED SCREEN DOTS, AND TO REDUCE THE FORMATION OF PEPPERS WHEN USING SOMEWHAT EXHAUSTED DEVELOPING BATHS.

Inventors

  • 👤 R Pollet
  • 👤 F Sels
  • 👤 H Philippaerts

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 10:49
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/04; G03C1/043; C; C08; C08G; C08G59/00; C08G59/18; C08G59/40; C08G59/62

Claims Analysis

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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) 1976-07-30 1977-01-29 1977-07-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-07-30 1981-01-29 1981-07-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-07-30 1985-01-29 1985-07-31 $7700.00 Window Closed / Lapsed

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