US3672900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fogged direct-positive emulsion production by increased flow of silver halide-forming precipitants in grain-ripenerfree acidic medium
Assignee: Eastman Kodak Co
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Filing: 1970-08-03
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Granted: 1972-06-27
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Expires: 1990-08-03
Abstract
Abstract A PROCESS IS DISCLOSED FOR MAKING IMPROVED, FOGGED, DIRECT-POSITIVE, SILVER HALIDE EMULSIONS. THE SILVER HALIDE GRAINS OF SAID EMULSIONS ARE MADE BY FORMING GRAINS OF AT LEST 0.4 MICRON IN SIZE IN A PRECIPITATION MEDIUM WHICH IS SUBSTANTIALLY FREE OF RIPENING AGENTS AND WHEREIN THE FLOW RATES OF THE RESPECTIVE REACTANTS TO FORM SAID SILVER HALIDE GRAINS ARE GRADUALLY INCREASED DURING THE GROWTH OF SAID GRAINS. PREFERABLY, THE PH IS MAINTAINED AT LESS THAN 4 AND AN OXIDIZING AGENT IS PRESENT DURING THE FORMATION OF THE GRAINS.
Inventors
- 👤 Richard Karl Kurz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:09
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/485; G03C1/48515; Y; Y10; Y10S; Y10S430/00; Y10S430/141
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |