US4666827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silver halide photographic emulsion
Assignee: Mitsubishi Paper Mills Ltd
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Filing: 1985-07-15
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Granted: 1987-05-19
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Expires: 2005-07-15
Abstract
Abstract Disclosed is a negative fine grain silver halide photographic emulsion capable of afford hard tone and high Dmax and have a markedly higher sensitivity than convertional roomlight handlable light-sensitive materials and free from defects such as fogging and decrease in sensitivity under roomlight conditions. This emulsion contains at least 70 mol % of silver chloride and an organic desensitizer which has an anodic polarographic potential and a cathodic polarographic potential which when added together give a positive sum, the amount of said organic desensitizer being such that necessary to reduce the sensitivity of said emulsion by not more than log E=1.3 (log E=1.0 in the case of silver chloride). This emulsion may further contain a rhodium salt.
Inventors
- 👤 Seiichi Sumi
- 👤 Katsuaki Iwaosa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:34
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
A negative silver halide photographic emulsion which is not spectrally sensitized, has an average grain size of not more than 0.4 μm and which contains at least 70 mol% of silver chloride and an organic desensitizer which has an anodic polarographic potential and a cathodic polarographic potential which when added together give a positive sum, the amount of said organic desensitizer being such as is necessary to reduce the sensitivity of said emulsion by not more than log E=1.3 (log E=1.0 in the case of silver chloride).
Claim 2
Dependent Claim
87 words
A negative silver halide photographic emulsion which is not spectrally sensitized, has an average grain size of not more than 0.4 μm and which contains at least 70 mol% of silver chloride and an organic desensitizer which has an anodic polarographic potential and a cathodic polarographic potential which when added together give a positive sum, the amount of said organic desensitizer being such as is necessary to reduce the sensitivity of said emulsion by not more than log E=1.3 (log E=1.0 in the case of silver chloride).
Claim 3
Dependent Claim
46 words
A negative silver halide photographic emulsion according to claim 1 wherein the amount of the organic desensitizer is such that necessary to reduce the sensitivity of the emulsion by log E≈0.2 to log E=1.3 (log E≈0.2 to log E=1.0 in the case of silver chloride emulsion).
Claim 4
Dependent Claim
44 words
A negative silver halide photographic emulsion according to claim 2 wherein the amount of the organic desensitizer is such that necessary to reduce sensitivity of the emulsion by log E≈0.3 to log E=1.0 (log E≈0.3 to log E=0.9 in case of silver chloride emulsion).
Claim 5
Dependent Claim
28 words
A negative silver halide photographic emulsion according to claim 1 wherein the amount of the organic desensitizer is about 0.1-about 10 mg per 1 mol of silver halide.
Claim 6
Dependent Claim
53 words
A negative silver halide photographic emulsion according to claim 1 which additionally contains a water soluble rhodium salt as a desensitizer, the total amount of the organic desensitizer and the water soluble rhodium salt being such that necessary to reduce the sensitivity of the silver halide emulsion by not more than log E=1.3.
Claim 7
Dependent Claim
32 words
A negative silver halide photographic emulsion according to claim 5 wherein the amount of the water soluble rhodium salt is less than about 10 -5 mol per 1 mol of silver halide.
Claim 8
Dependent Claim
33 words
A negative silver halide photographic emulsion according to claim 6 wherein the amount of the water soluble rhodium salt is about 10 -5 -about 10 -8 mol per 1 mol of silver halide.
Claim 9
Dependent Claim
26 words
A roomlight handling light-sensitive material which comprises a support and a layer coated thereon which comprises the negative silver halide photographic emulsion described in claim 1.
Claim 10
Dependent Claim
18 words
A negative silver halide photographic emulsion according to claim 1 wherein the average grain size is 0.1-0.3 μm.
References Cited (Backward Citations)
US3326687A
Cited
US3628958A
Cited
US3671254A
Cited
JPS56125734A
Cited
JPS56149030A
Cited
US4452882A
Cited
US4472497A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-18 | 1990-11-17 | 1991-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-18 | 1994-11-17 | 1995-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-18 | 1998-11-17 | 1999-05-19 | $7700.00 | Window Closed / Lapsed |