US4153462A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making silver halide emulsions
Assignee: Polaroid Corp
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Filing: 1975-08-14
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Granted: 1979-05-08
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Expires: 1995-08-14
Abstract
Abstract The present invention is directed to a method for forming the crystals of a photographic silver halide emulsion which comprises crystallizing silver halide grains from a solution of a water-soluble complex of silver halide complexed with excess halide ions. The crystals may be sensitized before the binder is added.
Inventors
- 👤 Arthur M. Gerber
- 👤 Vivian K. Walworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:03
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/015
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
62 words
A method of forming silver halide crystals which comprises crystallizing silver halide crystals from a solution of an inorganic water-soluble complex of silver halide complexed with excess halide, by disposing said solution in a dilution medium, wherein said dilution medium includes an agent for modulating the crystallization of said silver halide crystals and wherein said crystals are insoluble in said dilution medium.
Claim 2
Independent Claim
62 words
A method of forming silver halide crystals which comprises crystallizing silver halide crystals from a solution of an inorganic water-soluble complex of silver halide complexed with excess halide, by disposing said solution in a dilution medium, wherein said dilution medium includes an agent for modulating the crystallization of said silver halide crystals and wherein said crystals are insoluble in said dilution medium.
Claim 3
Dependent Claim
23 words
A method as defined in claim 1 which includes the steps of separating the thus-formed crystals and dispersing said crystals in a binder.
Claim 4
Dependent Claim
19 words
A method as defined in claim 1 wherein said solution is a saturated solution of said silver halide complex.
Claim 5
Dependent Claim
20 words
A method as defined in claim 1 wherein said dilution medium is at a substantially lower temperature than said solution.
Claim 6
Dependent Claim
15 words
A method as defined in claim 1 wherein said agent is a water-soluble halide salt.
Claim 7
Dependent Claim
23 words
A method as defined in claim 5 wherein said water-soluble halide salt comprises the same halide as the halide of the water-soluble complex.
Claim 8
Dependent Claim
23 words
A method as defined in claim 5 wherein said halide salt comprises a halide different from the halide employed in the water-soluble complex.
Claim 9
Dependent Claim
14 words
A method as defined in claim 1 wherein said agent includes an organic solvent.
Claim 10
Dependent Claim
12 words
A method as defined in claim 2 wherein said binder is gelatin.
Claim 11
Dependent Claim
35 words
A method as defined in claim 2 which includes the steps of adding a surfactant to the silver halide crystals and washing out said surfactant prior to dispersing said silver halide crystals in the binder.
Claim 12
Dependent Claim
18 words
The method as defined in claim 1 wherein the crystallization occurs in the presence of a photographic sensitizer.
Claim 13
Dependent Claim
14 words
The method as defined in claim 1 wherein said agent is a particulate material.
Claim 14
Dependent Claim
13 words
The method as defined in claim 12 wherein said agent is silver bromide.
Claim 15
Dependent Claim
13 words
The method as defined in claim 1 wherein said agent is potassium iodide.
Claim 16
Dependent Claim
21 words
The method as defined in claim 1 which includes the step of contacting the thus-formed crystals with a photographic sensitizing agent.
Claim 17
Dependent Claim
15 words
The method as defined in claim 15 wherein said sensitizing agent is a chemical sensitizer.
Claim 18
Dependent Claim
15 words
The method as defined in claim 15 wherein said sensitizing agent is a spectral sensitizer.
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) | 1982-05-07 | 1982-11-06 | 1983-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-07 | 1986-11-06 | 1987-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-07 | 1990-11-06 | 1991-05-08 | $7700.00 | Window Closed / Lapsed |