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US5178998A
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Process for the preparation of high chloride tabular grain emulsions (III)
Assignee: Eastman Kodak Co
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Filing: 1991-09-20
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Granted: 1993-01-12
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Expires: 2011-09-20
Abstract
Abstract A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to the silver ions further characterized by a chloride ion concentration of less than 0.5 molar and a grain growth modifier of the formula: ##STR1## where Z 8 is --C(R 8 )═ or --N═; R 8 is H, NH 2 or CH 3 ; and R 1 is hydrogen or a hydrocarbon of from 1 to 7 carbon atoms.
Inventors
- 👤 Joe E. Maskasky
- 👤 Yun C. Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:16
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/07; G03C1/0051; G03C1/0053; G03C1/015; G03C2001/0055; G03C2001/0156; G03C1/035; G03C2001/03511; G03C2200/00; G03C2200/03; G03C2200/42; G03C2200/43; G03C2200/44
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
134 words
A process of preparing a radiation sensitive high aspect ratio tabular grain emulsion, wherein tabular grains of less than 0.3 μm in thickness and an average aspect ratio of greater than 8:1 account for greater than 50 percent of the total grain projected area, said tabular grains containing at least 50 mole percent chloride, based on silver, comprising introducing silver ion into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to the silver ions further characterized by a chloride ion concentration of less than 0.5 molar and a grain growth modifier of the formula: ##STR15## where Z 8 is --C(R 8 )═ or --N═; R 8 is H, NH 2 of CH 3 ; and R 1 is hydrogen or a hydrocarbon of from 1 to 7 carbon atoms.
Claim 2
Dependent Claim
134 words
A process of preparing a radiation sensitive high aspect ratio tabular grain emulsion, wherein tabular grains of less than 0.3 μm in thickness and an average aspect ratio of greater than 8:1 account for greater than 50 percent of the total grain projected area, said tabular grains containing at least 50 mole percent chloride, based on silver, comprising introducing silver ion into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to the silver ions further characterized by a chloride ion concentration of less than 0.5 molar and a grain growth modifier of the formula: ##STR15## where Z 8 is --C(R 8 )═ or --N═; R 8 is H, NH 2 of CH 3 ; and R 1 is hydrogen or a hydrocarbon of from 1 to 7 carbon atoms.
Claim 3
Dependent Claim
19 words
A process according to claim 1 further characterized in that Z 8 is chosen to complete a xanthine nucleus.
Claim 4
Dependent Claim
18 words
A process according to claim 2 further characterized in that the grain growth modifier satisfies the formula: ##STR16##
Claim 5
Dependent Claim
20 words
A process according to claim 3 further characterized in that R 1 and R 8 are each hydrogen or methyl.
Claim 6
Dependent Claim
18 words
A process according to claim 1 further characterized in that R 1 and R 8 are each hydrogen.
Claim 7
Dependent Claim
18 words
A process according to claim 1 further characterized in that Z 8 is chosen to complete an 8-azaxanthine.
Claim 8
Dependent Claim
16 words
A process according to claim 6 further characterized in that the 8-azaxanthine satisfies the formula: ##STR17##
Claim 9
Dependent Claim
16 words
A process according to claim 7 further characterized in that R 1 is hydrogen or methyl.
Claim 10
Dependent Claim
14 words
A process according to claim 8 further characterized in that R 1 is hydrogen.
Claim 11
Dependent Claim
19 words
A process according to claim 1 further characterized in that the chloride ion concentration is less than 0.2 molar.
Claim 12
Dependent Claim
17 words
A process according to claim 1 further characterized in that the pH can range up to 9.
Claim 13
Dependent Claim
21 words
A process according to claim 11 further characterized in that the pH is in the range of from 4.5 to 8.
Claim 14
Dependent Claim
24 words
A process according to claim 1 further characterized in that the grain growth modifier is present in at least a 7×10 -4 molar concentration.
Claim 15
Dependent Claim
23 words
A process according to claim 1 further characterized in that the tabular grains contain less than 2 mole percent iodide, based on silver.
Claim 16
Dependent Claim
18 words
A process according to claim 1 further characterized in that the tabular grains consist essentially of silver chloride.
Claim 17
Dependent Claim
20 words
A process according to claim 1 further characterized in that the grain growth modifier is present during twin plane formation.
Claim 18
Dependent Claim
148 words
A process according to claim 1 further characterized in that the grain growth modifier is employed in combination with a second grain growth modifier chosen from the group consisting of: (a) iodide ions; (b) thiocyanate ions; and (c) a compound of the formula: ##STR18## wherein Z is C or N; R 1 , R 2 and R 3 , which may be the same or different, are H or alkyl of 1 to 5 carbon atoms; Z is C, R 2 and R 3 when taken together can be --CR 4 ═CR 5 -- or --CR 4 ═N--, wherein R 4 and R 5 , which may be the same or different, are H or alkyl of 1 to 5 carbon atoms, with the proviso that when R 2 and R 3 taken together form the --CR 4 ═N-- linkage, --CR 4 ═ must be joined to Z.
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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) | 1996-01-12 | 1996-07-13 | 1997-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-01-12 | 2000-07-13 | 2001-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-01-12 | 2004-07-13 | 2005-01-12 | $7700.00 | Window Closed / Lapsed |