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US4060419A
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Method of forming silver halide grains by electrolysis
Assignee: Polaroid Corp
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Filing: 1976-04-01
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Granted: 1977-11-29
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Expires: 1996-04-01
Abstract
Abstract Photosensitive silver halide emulsions are prepared by the precipitation of silver halide grains from silver and halide ions generated by electrolysis.
Inventors
- 👤 Arthur M. Gerber
- 👤 Vivian K. Walworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:07
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/0051
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
55 words
A method which comprises the electrolytic generation of silver ions and halide ions employing a silver anode and a cathode which is a source of halide ions and precipitation in the electrolyte of the ion pairs remove from the electrodes to provide photosensitive silver halide grains in the substantial absence of counterions in said electrolyte.
Claim 2
Independent Claim
55 words
A method which comprises the electrolytic generation of silver ions and halide ions employing a silver anode and a cathode which is a source of halide ions and precipitation in the electrolyte of the ion pairs remove from the electrodes to provide photosensitive silver halide grains in the substantial absence of counterions in said electrolyte.
Claim 3
Dependent Claim
25 words
The method as defined in claim 1 wherein said silver ions and said halide ions are generated substantially simultaneously in a solution of an electrolyte.
Claim 4
Dependent Claim
25 words
The method as defined in claim 1 wherein said silver ions and said negative ions are generated substantially simultaneously in a solution of an electrolyte.
Claim 5
Dependent Claim
14 words
The method as defined in claim 1 wherein said ions are generated substantially stoichiometrically.
Claim 6
Dependent Claim
13 words
The method as defined in claim 1 wherein said ions are generated nonstoichiometrically.
Claim 7
Dependent Claim
20 words
The method as defined in claim 1 which includes the step of growing the thus-formed grains to a predetermined size.
Claim 8
Dependent Claim
19 words
The method as defined in claim 1 where said silver halide grains have a substantially uniform grain size distribution.
Claim 9
Dependent Claim
17 words
The method as defined in claim 1 wherein said halide ions comprise a plurality of halide ions.
Claim 10
Dependent Claim
22 words
The method as defined in claim 1 wherein said silver ions and said halide ions are generated by a plurality of electrodes.
Claim 11
Dependent Claim
24 words
The method as defined in claim 9 wherein a plurality of cathodes and/or anodes are employed sequentially in the generation of said ion pairs.
Claim 12
Dependent Claim
25 words
The method as defined in claim 2 which includes disposing the grains in a polymeric binder prior to coating the thus-formed mixture on a support.
Claim 13
Dependent Claim
17 words
The method as defined in claim 1 wherein said solution of an electrolyte includes a polymeric binder.
Claim 14
Dependent Claim
13 words
The method as defined in claim 12 wherein said polymeric binder is gelatin.
Claim 15
Dependent Claim
16 words
The method as defined in claim 12 wherein said polymeric binder comprises a conductive polymeric binder.
Claim 16
Dependent Claim
15 words
The method as defined in claim 14 wherein said polymeric binder is poly-2-acrylamido-2-methyl-propane sulfonic acid.
Claim 17
Dependent Claim
20 words
A method as defined in claim 12 wherein said polymeric binder is a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and trimethylamine-N-acryloylmethylalaninimide.
Claim 18
Dependent Claim
20 words
The method as defined in claim 12 wherein said binder is present at a level of less than about 5%.
Claim 19
Dependent Claim
29 words
The method as defined in claim 3 wherein said ion pairs are generated from a silver anode and a halide salt cathode insoluble in said solution of an electrolyte.
Claim 20
Dependent Claim
13 words
The method as defined in claim 18 wherein said cathode is silver halide.
Claim 21
Dependent Claim
13 words
The method as defined in claim 19 wherein said cathode is silver bromide.
Claim 22
Dependent Claim
13 words
The method as defined n claim 19 wherein said cathode is silver iodobromide.
Claim 23
Dependent Claim
16 words
The method as defined in claim 1 wherein one of said electrodes comprises an elemental halogen.
Claim 24
Dependent Claim
12 words
The method as defined in claim 22 wherein said halogen is bromine.
Claim 25
Dependent Claim
19 words
The method as defined in claim 1 wherein said electrolyte comprises a sodium salt of ethylene diamine tetraacetic acid.
Claim 26
Dependent Claim
16 words
The method as defined in claim 1 which includes the step of Ostwald ripening said grains.
Claim 27
Dependent Claim
17 words
The method as defined in claim 3 wherein said solution of an electrolyte includes Ostwald ripening agents.
Claim 28
Dependent Claim
17 words
The method as defined in claim 3 wherein said solution of an electrolyte includes spectral sensitizing agents.
Claim 29
Dependent Claim
17 words
The method as defined in claim 3 wherein said solution of an electrolyte includes chemical sensitizing agents.
Claim 30
Dependent Claim
19 words
The method as defined in claim 25 which inclues the step of chemically sensitizing said grains subsequent to ripening.
Claim 31
Dependent Claim
19 words
The method as defined in claim 25 which includes the step of spectrally sensitizing said grains subsequent to ripening.
Claim 32
Dependent Claim
20 words
The method as defined in claim 25 which includes the step of Ostwald ripening said grains subsequent to gain formation.
Claim 33
Dependent Claim
20 words
The method as defined in claim 31 wherein said ripening step is carried out in the presence of ammonium hydroxide.
Claim 34
Dependent Claim
19 words
The method as defined in claim 31 wherein said ripening step is carried out in the presence of 2,2'-thiodiethanol.
Claim 35
Independent Claim
106 words
A method for forming a photographic silver halide emulsion layer which comprises the steps of: a. the substantially simultaneous generation of silver ions and halide ions in a solution of an electrolyte by electrolysis, employing a silver anode and a cathode which is a source of halide ions; b. precipitating the ion pairs remote from said anode and cathode to provide silver halide grains in the substantial absence of counterions in said electrolyte; c. growing said grains to a predetermined size; d. photographically sensitizing said grains; e. disposing said grains in a polymeric binder material; and f. coating said binder and said grains on a support.
Claim 36
Independent Claim
106 words
A method for forming a photographic silver halide emulsion layer which comprises the steps of: a. the substantially simultaneous generation of silver ions and halide ions in a solution of an electrolyte by electrolysis, employing a silver anode and a cathode which is a source of halide ions; b. precipitating the ion pairs remote from said anode and cathode to provide silver halide grains in the substantial absence of counterions in said electrolyte; c. growing said grains to a predetermined size; d. photographically sensitizing said grains; e. disposing said grains in a polymeric binder material; and f. coating said binder and said grains on a support.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |