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US3628958A
Expired / Lapsed
US
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Bipyridinium compound/nitrosubstituted n-heterocyclic compound desensitized silver halide emulsion
Assignee: Eastman Kodak Co
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Filing: 1970-03-02
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Granted: 1971-12-21
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Expires: 1990-03-02
Abstract
Abstract A negative silver halide emulsion is desensitized with a desensitizing combination of a bipyridinium salt and an organic nitrosubstituted N-heterocyclic desensitizer. The emulsion is effectively desensitized for handling in roomlight and the sensitometric properties of the desensitized emulsion are improved with respect to emulsions desensitized with, for example, known organic nitrosubstituted N-heterocyclic desensitizers.
Inventors
- 👤 John A Haefner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:17
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/36
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
A desensitized negative silver halide photographic emulsion according to claim 1 wherein said desensitizer combination is present in an amount of at least 50 mg. per mole of silver, and said organic desensitizer is present in an amount of from 25-75 percent by weight of the combination and is selected from the group consisting of nitro-substituted thiazoles and compounds of benzothiazole, quinoline, indolenine, benzotriazole, and rhodanine having one or more nitro groups attached to a benzene nucleus of said compounds, said benzene nucleus being either a part of the heterocyclic moiety of said compound or attached thereto through a doubly bonded carbon chain.
Claim 2
Dependent Claim
62 words
A desensitized negative silver halide photographic emulsion as claimed in claim 1 wherein said organic desensitizer is present in an amount of from 35-65 percent by weight of said combination and is selected from the groups consisting of 2-mercapto-4-methyl-5-nitrothiazole, 2-methyl-6-nitrobenzothiazole metho-p-toluene sulfonate, 2-nitorstyryl-3-ethylbenzothiazolium iodide, 2-(o,p-dinitrostyryl)-3-ethylbenzothiazolium iodide, 2-(o,p-dinitrostyryl)-benzothiazole, 2-(p-nitrostyryl)-quinoline metho-p-toluene sulfonate, 6-ethoxy-2-nitrostyryl-quinoline metho-p-toluene sulfonate, 4-(p-nitrostyryl)-indolenine methiodide, 2-(p-dimethylaminostyryl)-3-ethyl-6-nitrobenzothiazolium chloride, 6-nitrobenzo-1,2,3-triazole, 4-chloro-6-nitrobenzo-1,2,3-triazole, 5-chloro-6-nitrobenzo-1,2,3-triazole, and 5-o-nitrobenzylidene-3-ethylrhodanine.
Claim 3
Dependent Claim
71 words
A desensitized negative silver halide photographic emulsion according to claim 1 wherein said desensitizer combination is present in an amount of at least 50 mg. per mole of silver, the pyridinium component is present in an amount of 25-75 percent by weight of said combination and wherein the linkage of said pyridinium compound is selected from the group consisting of a single covalent bond, a vinylene linkage and an ethylene linkage.
Claim 4
Dependent Claim
40 words
A desensitized negative silver halide photographic emulsion according to claim 4 wherein said bipyridinium salt is present in an amount of from 35 to 65 percent by weight of said desensitizer combination and is selected from compounds having the formulas:
Claim 5
Dependent Claim
50 words
A negative silver halide photographic emulsion according to claim 5 wherein said bipyridinium compound is a member selected from the group consisting of: 1,1''-dibutyl-4,4''-bipyridinium dibromide, 1,1''-dibutyl-4,4''-bipyridinium diperchlorate, 1,1''-di(2-hydroxyethyl)-4,4''-bipyridinium dibromide 1,1''-diphenacyl-4, 4''-bipyridinium dibromide, 1,2-di(4-pyridyl)ethylene bis(phenacyl bromide), 1,2-di(4-pyridyl)ethylene bis(phenethobromide), dianhydro-1,2-di(1-(3-sulfopropyl)-4-pyridyl)ethylene dihydroxide 1,2-di(4-pyridyl)ethylene bis(methobromide), 1,1''-dimethyl-4,4''-bipyridinium dibromide, 1,2-di(4-pyridyl)ethane bis(phenethobromide), 1,1''-ethylene-2,2''-bipyridinium dibromide, and 1,1''-tetramethylene-2,2''-bipyridinium dibromide.
Claim 6
Dependent Claim
58 words
A negative silver halide photographic emulsion according to claim 1 containing, per mole of silver, 50 to 500 mg. of a desensitizer combination consisting essentially of from 25 to 75 percent by weight of 1,1''-di-n-butyl-4,4''-bipyridinium dihalide, and from 25 to 75 percent by weight of a member selected from the group consisting of 2-mercapto-4-methyl-5-nitrothiazole and 2-methyl-6-nitrobenzothiazole metho-p-toluene sulfonate.
Claim 7
Dependent Claim
20 words
A photographic element comprising a support having thereon a desensitized negative silver halide emulsion layer as claimed in claim 1.
Claim 8
Dependent Claim
20 words
A photographic element comprising a support having thereon a desensitized negative silver halide emulsion layer as claimed in claim 7.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |