US3779776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fogged, direct-positive silver halide emulsion containing a color coupler and a heterocyclic mercaptan desensitizer
Assignee: Agfa Gevaert NV
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Filing: 1972-07-07
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Granted: 1973-12-18
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Expires: 1992-07-07
Abstract
Abstract WHEREIN: R1 is hydroxyl or C1-C5 alkyl, R2 is hydrogen or C1-C5 alkyl, R3 is C1- C5 alkyl or aryl, A is a single bond or NH, B is a phenyl or diphenyl sulphone group in which the or both phenyl group(s) is (are) substituted with one or more nitro groups, and N IS 1, 2, OR 3. The desensitizing agents are highly compatible with color couplers. A direct-positive photographic color element is described wherein the fogged silver halide emulsion comprises a color coupler and a desensitizing agent or precursor of such desensitizing agent wherein said desensitizing agent has one of the following general formulae, a tautomeric form thereof or is a corresponding disulphide :
Inventors
- 👤 W Vanassche
- 👤 R Pollet
- 👤 H Borginon
- 👤 H Pattyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:15
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/485; G03C1/48515; G03C1/48523
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
88 words
A direct-positive photographic element according to claim 1, wherein the said desensitizing agent precursor is a compound corresponding to one of the general formulae of claim 1, or a tautomeric form thereof, wherein the tautomeric hydrogen atom is replaced by a -COX group in which X represents alkyl, aralkyl, aryl, or a group identical to the diazine group linked to the carbonyl group of -COX, by a -SO2Y group in which Y is alkyl, aryl, or aralkyl, or by a -COOZ group wherein Z is alkyl or aryl.
Claim 2
Dependent Claim
34 words
A direct-positive photographic element according to claim 1, wherein the said desensitizing agent or desensitizing agent precursor is present in an amount comprised between 100 mg and 2 g per mole of silver halide.
Claim 3
Dependent Claim
19 words
A direct-positive photographic element according to claim 1, wherein the silver halide has been fogged uniformly by chemical means.
Claim 4
Dependent Claim
21 words
A direct-positive photographic element according to claim 4 wherein the silver halide has been fogged uniformly by means of reducing agents.
Claim 5
Dependent Claim
15 words
A direct-positive photographic element according to claim 5, wherein said reducing agent is thiourea dioxide.
Claim 6
Dependent Claim
22 words
A direct-positive photographic element according to claim 4, wherein the silver halide has been fogged uniformly by means of a gold compound.
Claim 7
Dependent Claim
26 words
A direct-positive photographic element according to claim 4, wherein the silver halide has been fogged uniformly by means of a reducing agent and a gold compound.
Claim 8
Dependent Claim
15 words
A direct-positive photographic element according to claim 8, wherein said reducing agent is thiourea dioxide.
Claim 9
Dependent Claim
30 words
A direct-positive photographic element according to claim 1, wherein the silver halide has been fogged uniformly by means of high pH and/or low pAg silver halide precipitating and digestion conditions.
Claim 10
Dependent Claim
34 words
A direct-positive element according to claim 1, wherein the silver halide has been fogged uniformly by means of a gold compound and by high pH and/or low pAg silver halide prEcipitating and digestion conditions.
Claim 11
Dependent Claim
20 words
A direct-positive photographic element according to claim 1, wherein the silver halides of the emulsion have a substantially uniform diameter.
Claim 12
Dependent Claim
23 words
A direct-positive photographic element according to claim 1, wherein the silver halide grains have an average grain size of less than 1 micron.
Claim 13
Dependent Claim
38 words
A method of producing a direct-positive image, which comprises exposing image-wise to radiation a direct-positive element according to claim 1, and developing the exposed material in a silver halide developer comprising an aromatic primary amino color developing agent.
References Cited (Backward Citations)
US2901351A
Cited
US3501305A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |