Patent US5132203A successfully refreshed from Google Patents.
US5132203A
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US
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Tabular grain emulsions containing laminar halide strata
Assignee: Eastman Kodak Co
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Filing: 1991-03-11
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Granted: 1992-07-21
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Expires: 2011-03-11
Abstract
Abstract Photographic emulsions are disclosed comprised of radiation sensitive silver iodobromide grains, at least 50 percent of the total projected area of said silver iodobromide grains being accounted for by tabular grains exhibiting a mean tabularity of greater than 5, at least 10 percent of which are comprised of two opposed parallel major crystal faces, a host stratum having an iodide content of at least 4 mole percent, and laminar strata containing less than 2 mole percent iodide interposed between said host stratum and said opposed major crystal faces. The emulsions are characterized in that each of the laminar strata is comprised of a surface layer forming one of the major surfaces and having a thickness in the range of from 20 to 350 Å and a subsurface layer located immediately beneath and in contact with the surface layer containing a hexacoordination complex of a Group VIII period 4 or 5 metal and at least three cyanide ligands.
Inventors
- 👤 Eric L. Bell
- 👤 Kenneth J. Reed
- 👤 Myra T. Olm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:23
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/08; G03C1/0051; G03C1/035; G03C2001/03535; G03C2001/03558; G03C2001/0845; G03C2001/0854; G03C5/00; G03C5/26; G03C5/50
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
171 words
A photographic emulsion comprised of radiation sensitive silver iodobromide grains, at least 50 percent of the total projected area of said silver iodobromide grains being accounted for by tabular grains exhibiting a means tabularity of greater than 5, at least 10 percent of which are comprised of two opposed parallel major crystal faces, a host stratum having an iodide content of at least 4 mole percent, and laminar strata containing less than 2 mole percent iodide forming said opposed major crystal faces and separating said host stratum from said opposed major crystal faces, characterized in that each of said laminar strata is comprised of a surface layer forming one of said major crystal faces and having a thickness in the range of from 20 to 350 Å and which is not doped with a transition metal coordination complex, and a subsurface layer located immediately beneath and in contact with said surface layer containing a hexacoordination complex of a Group VIII period 4 or 5 metal and at least three cyanide ligands.
Claim 2
Dependent Claim
171 words
A photographic emulsion comprised of radiation sensitive silver iodobromide grains, at least 50 percent of the total projected area of said silver iodobromide grains being accounted for by tabular grains exhibiting a means tabularity of greater than 5, at least 10 percent of which are comprised of two opposed parallel major crystal faces, a host stratum having an iodide content of at least 4 mole percent, and laminar strata containing less than 2 mole percent iodide forming said opposed major crystal faces and separating said host stratum from said opposed major crystal faces, characterized in that each of said laminar strata is comprised of a surface layer forming one of said major crystal faces and having a thickness in the range of from 20 to 350 Å and which is not doped with a transition metal coordination complex, and a subsurface layer located immediately beneath and in contact with said surface layer containing a hexacoordination complex of a Group VIII period 4 or 5 metal and at least three cyanide ligands.
Claim 3
Dependent Claim
24 words
An emulsion according to claim 1 further characterized in that said host stratum accounts for from 20 to 80 percent of total grain volume.
Claim 4
Dependent Claim
24 words
An emulsion according to claim 2 further characterized in that said host stratum accounts for from 35 to 65 percent of total grain volume.
Claim 5
Dependent Claim
26 words
An emulsion according to claim 1 further characterized in that said tabular grains contain from about 0.1 to 20 mole percent iodide, based on total silver.
Claim 6
Dependent Claim
26 words
An emulsion according to claim 4 further characterized in that said tabular grains contain from about 1 to 10 mole percent iodide, based on total silver.
Claim 7
Dependent Claim
24 words
An emulsion according to claim 1 further characterized in that a spectral sensitizing dye is adsorbed to the major faces of the tabular grains.
Claim 8
Dependent Claim
29 words
An emulsion according to claim 1 further characterized in that the concentration of said hexacoordination complex in said subsurface layer is less than 0.1 mole percent, based on silver.
Claim 9
Dependent Claim
36 words
An emulsion according to claim 7 further characterized in that the concentration of said hexacoordination complex in said subsurface layer is in the range of from 2.5×10 -3 to 5×10 -2 mole percent, based on silver.
Claim 10
Dependent Claim
37 words
An emulsion according to claim 1 further characterized in that said laminar strata additionally each includes an isolation layer containing less than 2 mole percent iodide interposed between said host stratum and each of said subsurface layers.
Claim 11
Dependent Claim
20 words
An emulsion according to claim 9 further characterized in that surface and subsurface layers are each substantially free of iodide.
Claim 12
Dependent Claim
57 words
An emulsion according to claim 1 further characterized in that said hexacoordination complex satisfies the formula: [M(CN).sub.6-y L.sub.y ].sup.n where M is a transition metal chosen from one of periods 4 and 5 of Group VIII, L is a bridging ligand, y is the integer zero, 1, 2 or 3 and n is -2, -3, or -4.
Claim 13
Dependent Claim
15 words
An emulsion according to claim 11 further characterized in that L is a halide ligand.
Claim 14
Dependent Claim
19 words
An emulsion according to claim 11 further characterized in that M is chosen from among iron, ruthenium and rhodium.
Claim 15
Dependent Claim
18 words
An emulsion according to claim 13 further characterized in that said hexacoordination complex satisfies the formula [Fe(CN).sub.6 ].sup.-4.
Claim 16
Dependent Claim
25 words
An emulsion according to claim 1 further characterized in that said surface layers have a thickness in the range of from 25 to 100 Å.
Claim 17
Dependent Claim
22 words
An emulsion according to claim 1 further characterized in that the iodide in said laminar strata is less than 1.5 mole percent.
Claim 18
Dependent Claim
23 words
An emulsion according to claim 16 further characterized in that the iodide level in the laminar strata is less than 1.0 mole percent.
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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) | 1995-07-21 | 1996-01-20 | 1996-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-21 | 2000-01-20 | 2000-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-21 | 2004-01-20 | 2004-07-21 | $7700.00 | Window Closed / Lapsed |