US3632348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methine dye sensitizers for emulsions exposed at{31 180{20 {0 c.
Assignee: Eastman Kodak Co
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Filing: 1969-05-07
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Granted: 1972-01-04
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Expires: 1989-05-07
Abstract
Abstract Photographic silver halide emulsions which are exposed at low temperatures have adsorbed thereto a sufficient amount of a methine dye to increase the sensitivity and contrast of the emulsion at temperatures below about -180* C. The highest occupied electronic energy level of the methine dye adsorbed on the silver halide is more positive than the highest occupied energy level in the valence band of the silver halide, and the lowest vacant electronic energy level of the dye adsorbed on the silver halide is more positive than the conduction band of the silver halide. Particularly good results are obtained with the quinoline monomethine cyanines. Preferred results are obtained when the dye is employed in a concentration sufficient to give monomolecular layer coverage of the silver halide grains.
Inventors
- 👤 Thomas H James
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:38
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/08; G03C1/10; G03C1/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
48 words
The process of making photographic images as defined in claim 1 wherein said Z1, Z2 and Z3 in the structural formulas each represents the atoms required to complete a nucleus selected from the group consisting of a thiazole nucleus, an oxazole nucleus, selenazole nucleus, and a quinoline nucleus.
Claim 2
Dependent Claim
90 words
In a process of making photographic images wherein a light-sensitive photographic emulsion is exposed to radiation at a temperature below about -180* C. to produce a latent image, and said latent image is developed to a silver image: the improvement which comprises employing in said process a negative, unfogged photographic silver halide emulsion in which the silver halide grains thereof have adsorbed thereto a sufficient amount of a quinoline monomethine cyanine dye to effectively increase the speed of said silver halide when exposed at a temperature below about -180* C.
Claim 3
Dependent Claim
126 words
In a process of making photographic images wherein a light-sensitive photographic emulsion is exposed to radiation at a temperature below about -180* C. to produce a latent image, and said latent image is developed to a silver image: the improvement which comprises employing in said process a negative, unfogged photographic silver halide emulsion in which the silver halide grains thereof have adsorbed thereto a dye selected from the group consisting of 1,1'',3,3''-tetramethyl-2,2''-cyanine dye salt; a 3,3''-diethylthiacarbocyanine dye salt; 2-(p-dimethyl-aminostyryl)-1-methyl pyridinium dye salt; 1,1''-diethyl-2,2''-cyanine dye salt; 1,1''-dimethyl-2,2''-cyanine dye salt; 1,1''-diethyl-2,4''-cyanine dye salt; and, 1-methyl-1'',9-diethyl-2,2''-cyanine dye salt; said silver halide having a sufficient amount of said dye Adsorbed thereto to effectively increase the speed and contrast of said silver halide when exposed at a temperature of -180* C.
Claim 4
Dependent Claim
34 words
The process of making photographic images as defined in claim 5 wherein said dye is adsorbed onto said silver halide in a concentration sufficient to give monomolecular layer coverage of the silver halide grains.
Claim 5
Dependent Claim
82 words
In a process of making photographic images wherein a light-sensitive photographic silver halide emulsion is exposed to radiation at a temperature below about -180* C. to produce a latent image, and said latent image is developed to a silver image: the improvement which comprises employing in said process an unfogged cubic-regular grain silver bromoiodide gelatin emulsion, the grains of said emulsion having a size of about 0.2 microns, said grains having adsorbed thereto a monomolecular layer coverage of a 1,1''-diethyl-2,2''-cyanine dye salt.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |