Patent US4414306A successfully refreshed from Google Patents.
US4414306A
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Silver chlorobromide emulsions and processes for their preparation
Assignee: Eastman Kodak Co
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Filing: 1982-09-30
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Granted: 1983-11-08
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Expires: 2002-09-30
Abstract
Abstract Tabular grain silver halide emulsions are disclosed containing chloride and bromide in at least annular grain regions. The tabular grains having a thickness of less than 0.5 micron, preferably less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of at least 5:1, account for at least 35 percent of the total projected area of the total silver halide grain population. The average molar ratio of chloride to bromide in at least the annular grain regions ranges up to 2:3. The tabular grains containing chloride and bromide in at least annular grain regions are formed by maintaining a molar ratio of chloride and bromide ions of from 1.6:1 to 258:1 and the total concentration of halide ions in the reaction vessel in the range of from 0.10 to 0.90 N during introduction of silver, chloride, and bromide salts into a reaction vessel, thereby favoring the coprecipitation of chloride and bromide in a tabular crystal habit.
Inventors
- 👤 Jong-Shinn Wey
- 👤 Herbert S. Wilgus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:53
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/0051
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
98 words
A radiation-sensitive emulsion comprised of a dispersing medium and silver halide grains including tabular grains having opposed, substantially parallel {111} major faces, said tabular grains containing chloride and bromide in at least annular grain regions, said tabular grains having a thickness of less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of at least 5:1 accounting for at least 35 percent of the total projected area of said silver halide grains, and the average molar ratio of chloride to bromide in at least said annular grain regions ranging up to 2:3.
Claim 2
Dependent Claim
98 words
A radiation-sensitive emulsion comprised of a dispersing medium and silver halide grains including tabular grains having opposed, substantially parallel {111} major faces, said tabular grains containing chloride and bromide in at least annular grain regions, said tabular grains having a thickness of less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of at least 5:1 accounting for at least 35 percent of the total projected area of said silver halide grains, and the average molar ratio of chloride to bromide in at least said annular grain regions ranging up to 2:3.
Claim 3
Dependent Claim
16 words
A radiation-sensitive emulsion according to claim 1 wherein the average aspect ratio is greater than 8:1.
Claim 4
Dependent Claim
14 words
A radiation-sensitive emulsion according to claim 1 wherein said dispersing medium contains a peptizer.
Claim 5
Dependent Claim
16 words
A radiation-sensitive emulsion according to claim 3 wherein said peptizer is gelatin or a gelatin derivative.
Claim 6
Dependent Claim
27 words
A radiation-sensitive emulsion according to claim 1 wherein said tabular grains account for at least 50 percent of the total projected area of said silver halide grains.
Claim 7
Dependent Claim
19 words
A radiation-sensitive emulsion according to claim 1 wherein the molar ratio of chloride to bromide is at least 1:99.
Claim 8
Dependent Claim
14 words
A radiation-sensitive emulsion according to claim 1 wherein said tabular grains additionally contain iodide.
Claim 9
Dependent Claim
21 words
A radiation-sensitive emulsion according to claim 1 wherein said silver halide grains are substantially free of chloride in a central region.
Claim 10
Dependent Claim
21 words
A radiation-sensitive emulsion according to claim 1 wherein said tabular grains include a central region which consists essentially of silver bromide.
Claim 11
Dependent Claim
68 words
A radiation-sensitive emulsion comprised of a dispersing medium and silver chlorobromide grains, at least 50 percent of the total projected area of said silver chlorobromide grains, being provided by tabular grains having a thickness of less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of greater than 8:1, and said silver chlorobromide grains containing from 1 to 30 mole percent chloride.
Claim 12
Dependent Claim
68 words
A radiation-sensitive emulsion comprised of a dispersing medium and silver chlorobromide grains, at least 50 percent of the total projected area of said silver chlorobromide grains, being provided by tabular grains having a thickness of less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of greater than 8:1, and said silver chlorobromide grains containing from 1 to 30 mole percent chloride.
Claim 13
Dependent Claim
28 words
A radiation-sensitive emulsion according to claim 10 in which said tabular grains account for at least 70 percent of the total projected area of said silver chlorobromide grains.
Claim 14
Dependent Claim
21 words
A radiation-sensitive emulsion according to claim 10 in which said silver chlorobromide grains contain from 5 to 20 mole percent chloride.
Claim 15
Dependent Claim
42 words
In a photographic element comprised of a support and at least one radiation-sensitive emulsion layer, the improvement wherein said emulsion layer is comprised of an emulsion according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.
Claim 16
Dependent Claim
31 words
A process of producing a visible photographic image comprising processing in an aqueous alkaline solution in the presence of a developing agent an imagewise exposed photographic element according to claim 13.
Claim 17
Dependent Claim
124 words
In a process of preparing a radiation-sensitive emulsion comprised of a dispersing medium and silver halide grains containing chloride and bromide by concurrently introducing silver, chloride, and bromide salts into a reaction vessel containing at least a portion of the dispersing medium, the improvement wherein tabular silver halide grains containing chloride and bromide in a molar ratio of chloride to bromide of from 1:99 to 2:3 in at least an annular grain region are formed, during introduction of the silver, chloride, and bromide salts, by maintaining a molar ratio of chloride to bromide ions in the reaction vessel of from 1.6:1 to 258:1, and maintaining the total concentration of halide ions in the reaction vessel in the range of from 0.10 to 0.90 normal.
Claim 18
Dependent Claim
124 words
In a process of preparing a radiation-sensitive emulsion comprised of a dispersing medium and silver halide grains containing chloride and bromide by concurrently introducing silver, chloride, and bromide salts into a reaction vessel containing at least a portion of the dispersing medium, the improvement wherein tabular silver halide grains containing chloride and bromide in a molar ratio of chloride to bromide of from 1:99 to 2:3 in at least an annular grain region are formed, during introduction of the silver, chloride, and bromide salts, by maintaining a molar ratio of chloride to bromide ions in the reaction vessel of from 1.6:1 to 258:1, and maintaining the total concentration of halide ions in the reaction vessel in the range of from 0.10 to 0.90 normal.
Claim 19
Dependent Claim
28 words
An improved process according to claim 15, wherein a peptizer is introduced into the reaction vessel so that it is present during the coprecipitation of chloride and bromide.
Claim 20
Dependent Claim
33 words
An improved process according to claim 15, wherein the contents of the reaction vessel are maintained within the temperature range of from 30 to 90° C. during the coprecipitation of chloride and bromide.
Claim 21
Dependent Claim
33 words
An improved process according to claim 17, wherein the contents of the reaction vessel are maintained within the temperature range of from 40 to 80° C. during the coprecipitation of chloride and bromide.
Claim 22
Dependent Claim
30 words
An improved process according to claim 15, wherein the halide ion concentration is maintained within the range of from 0.30 to 0.60 N during the coprecipitation of chloride and bromide.
Claim 23
Dependent Claim
36 words
An improved process according to claim 19, wherein the molar ratio of chloride to bromide ions in the reaction vessel is maintained in the range of from 1.6:1 to 184:1 during coprecipitation of chloride and bromide.
Claim 24
Dependent Claim
24 words
An improved process according to claim 15, wherein an iodide salt is introduced into the reaction vessel during the coprecipitation of chloride and bromide.
Claim 25
Dependent Claim
30 words
An improved process according to claim 15, wherein the reaction vessel is maintained substantially free of silver halide grains prior to the concurrent introduction of silver, bromide, and chloride salts.
Claim 26
Dependent Claim
34 words
An improved process according to claim 15, which comprises forming in the reaction vessel or introducing into the reaction vessel prior to the concurrent introduction of silver, bromide, and chloride salts, silver halide grains.
Claim 27
Dependent Claim
41 words
An improved process according to claim 23, which comprises initially forming in the reaction vessel or introducing into the reaction vessel, silver halide grains that are substantially free of chloride prior to the concurrent introduction of silver, bromide, and chloride salts.
Claim 28
Dependent Claim
35 words
An improved process according to claim 24, which comprises initially forming in the reaction vessel or introducing into the reaction vessel silver bromide grains prior to the concurrent introduction of silver, bromide, and chloride salts.
Claim 29
Dependent Claim
98 words
A radiation-sensitive emulsion comprised of a dispersing medium and silver halide grains including tabular grains having opposed, substantially parallel {1111} major faces, said tabular grains containing chloride and bromide in at least annular grain regions, said tabular grains having a thickness of less than 0.5 micron, a diameter of at least 0.6 micron, and an average aspect ratio of at least 5:1 accounting for at least 35 percent of the total projected area of said silver halide grains, and the average molar ratio of chloride to bromide in at least said annular grain regions ranging up to 2:3.
Claim 30
Dependent Claim
98 words
A radiation-sensitive emulsion comprised of a dispersing medium and silver halide grains including tabular grains having opposed, substantially parallel {1111} major faces, said tabular grains containing chloride and bromide in at least annular grain regions, said tabular grains having a thickness of less than 0.5 micron, a diameter of at least 0.6 micron, and an average aspect ratio of at least 5:1 accounting for at least 35 percent of the total projected area of said silver halide grains, and the average molar ratio of chloride to bromide in at least said annular grain regions ranging up to 2:3.
Claim 31
Dependent Claim
16 words
A radiation-sensitive emulsion according to claim 26 wherein the average aspect ratio is greater than 8:1.
Claim 32
Dependent Claim
14 words
A radiation-sensitive emulsion according to claim 26 wherein said dispersing medium contains a peptizer.
Claim 33
Dependent Claim
16 words
A radiation-sensitive emulsion according to claim 28 wherein said peptizer is gelatin or a gelatin derivative.
Claim 34
Dependent Claim
26 words
A radiation-sensitive emulsion according to claim 26 wherein said tabular grains account for least 50 percent of the total projected area of said silver halide grains.
Claim 35
Dependent Claim
19 words
A radiation-sensitive emulsion according to claim 26 wherein the molar ratio of chloride to bromide is at least 1:99.
Claim 36
Dependent Claim
16 words
A radiation-sensitive emulsion according to claim claim 26 wherein the said tabular grains additionally contain iodide.
Claim 37
Dependent Claim
21 words
A radiation-sensitive emulsion according to claim 26 wherein said silver halide grains are substantially free of chloride in a central region.
Claim 38
Dependent Claim
21 words
A radiation-sensitive emulsion according to claim 26 wherein said tabular grains include a central region which consists essentially of silver bromide.
Claim 39
Dependent Claim
39 words
In a photographic element comprised of a support and at least one radiation-sensitive emulsion layer, the improvement wherein said emulsion layer is comprised of an emulsion according to claim 26, 27, 28, 29, 30, 31, 32, 33, or 34.
Claim 40
Dependent Claim
31 words
A process of producing a visible photographic image comprising processing in an aqueous alkaline solution in the presence of a developing agent an imagewise exposed photographic element according to claim 35.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |