US4746603A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Negative type silver halide photographic emulsions
Assignee: Fujifilm Holdings Corp
•
Filing: 1986-07-03
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Granted: 1988-05-24
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Expires: 2006-07-03
Abstract
Abstract Negative type silver halide photographic emulsions are provided, formed by growing silver halide grains in the presence of a water-soluble iridium salt in a molar ratio of 3×10 -4 mol or more to the amount of the total silver halides used in the formation of the silver halide grains and then chemically sensitizing the surfaces of the grains formed with a sulfur compound or with a sulfur compound and a gold compound. The present emulsions have high sensitivity and extremely improved variation of sensitivity and gradation under broad exposure conditions of high intensity exposure and low intensity exposure.
Inventors
- 👤 Seiji Yamashita
- 👤 Naoto Ohshima
- 👤 Shunji Takada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:06
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/08; G03C1/09
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
A negative type silver halide photographic emulsion formed by growing silver halide grains in the presence of a water-soluble iridium salt in a molar ratio of 3×10 -4 mol or more to the amount of the total silver halides used in the formation of the silver halide grains and then chemically sensitizing the surfaces of the grains formed with a sulfur compound or with a sulfur compound and a gold compound.
Claim 2
Dependent Claim
71 words
A negative type silver halide photographic emulsion formed by growing silver halide grains in the presence of a water-soluble iridium salt in a molar ratio of 3×10 -4 mol or more to the amount of the total silver halides used in the formation of the silver halide grains and then chemically sensitizing the surfaces of the grains formed with a sulfur compound or with a sulfur compound and a gold compound.
Claim 3
Dependent Claim
49 words
The negative type silver halide photographic emulsion as claimed in claim 1, wherein the molar ratio of the water-soluble iridium salt to be incorporated is 5×10 -4 mol to 3×10 -3 mol to the amount of the total silver halides used in the formation of the silver halide grains.
Claim 4
Dependent Claim
37 words
The negative type silver halide photographic emulsion as claimed in claim 1, wherein the total amount of the water-soluble iridium salt is added all at once at any stage during the formation of the silver halide grains.
Claim 5
Dependent Claim
25 words
The negative type silver halide photographic emulsion as claimed in claim 1, wherein the water-soluble iridium salt is added at intervals in several separate amounts.
Claim 6
Dependent Claim
21 words
The negative type silver halide photographic emulsion as claimed in claim 1, wherein the water-soluble iridium salt is gradually added continuously.
Claim 7
Dependent Claim
47 words
The negative type silver halide photographic emulsion as claimed in claim 4, wherein 80% or more of the total amount of the water-soluble iridium salt to be added is added after the silver halide grains have grown to 70% or more of the average grain size thereof.
Claim 8
Dependent Claim
42 words
The negative type silver halide photographic emulsion as claimed in claim 1, wherein the water-soluble iridium salt is selected from K 3 IrCl 6 , K 2 IrCl 6 , (NH 4 ) 2 IrCl 6 and Na 2 IrCl 6 .
Claim 9
Dependent Claim
34 words
The negative type silver halide photographic emulsion as claimed in claim 1, wherein an iridium compound stabilizer of a hydrogen halide aqueous solution or an alkali halide is added together with the iridium compound.
References Cited (Backward Citations)
US2448060A
Cited
US4288535A
Cited
US4477561A
Cited
US4617258A
Cited
US4469783A
Cited
US4621041A
Cited
US4621041B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |