US4476220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spectrally sensitized photothermographic materials and preparation thereof
Assignee: Eastman Kodak Co
•
Filing: 1983-07-01
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Granted: 1984-10-09
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Expires: 2003-07-01
Abstract
Abstract Photothermographic emulsions display enhanced spectral sensitization when the silver halide grains are formed in the presence of one or more spectral sensitizing dyes.
Inventors
- 👤 Keith A. Penfound
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:47
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/494; G03C1/498; G03C1/49818
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
114 words
A process for preparing a photothermographic material which comprises: forming a dispersion of a long chain fatty acid in water maintained at a temperature above the melting point of the acid, converting at least part of the acid to an ammonium or alkali metal salt of the acid, and converting said salt of the acid to a silver salt, in which silver halide grains are added to the dispersion of the acid, to the ammonium or alkali metal salt thereof, or to said silver salt, characterized in that the silver halide grains are spectrally sensitized silver halide grains obtained by forming silver halide grains in the presence of one or more spectral sensitizing dyes.
Claim 2
Dependent Claim
114 words
A process for preparing a photothermographic material which comprises: forming a dispersion of a long chain fatty acid in water maintained at a temperature above the melting point of the acid, converting at least part of the acid to an ammonium or alkali metal salt of the acid, and converting said salt of the acid to a silver salt, in which silver halide grains are added to the dispersion of the acid, to the ammonium or alkali metal salt thereof, or to said silver salt, characterized in that the silver halide grains are spectrally sensitized silver halide grains obtained by forming silver halide grains in the presence of one or more spectral sensitizing dyes.
Claim 3
Dependent Claim
24 words
A process as claimed in claim 1, characterized in that spectral sensitizing dye is present at the start of emulsification of the silver halide.
Claim 4
Dependent Claim
28 words
A process as claimed in claim 1, characterized in that spectral sensitizing dye is added after emulsification of the silver halide has begun but before completion of emulsification.
Claim 5
Dependent Claim
20 words
A process as claimed in claim 1, characterized in that the spectral sensitizing dye is a cyanine or merocyanine dye.
Claim 6
Dependent Claim
20 words
A process as claimed in claim 2, characterized in that the spectral sensitizing dye is a cyanine or merocyanine dye.
Claim 7
Dependent Claim
20 words
A process as claimed in claim 3, characterized in that the spectral sensitizing dye is a cyanine or merocyanine dye.
Claim 8
Dependent Claim
18 words
A process as claimed in claim 1, characterized in that the spectral sensitizing dye is a J-banding dye.
Claim 9
Dependent Claim
18 words
A process as claimed in claim 3, characterized in that the spectral sensitizing dye is a J-banding dye.
Claim 10
Dependent Claim
18 words
A process as claimed in claim 4, characterized in that the spectral sensitizing dye is a J-banding dye.
Claim 11
Dependent Claim
18 words
A process as claimed in claim 6, characterized in that the spectral sensitizing dye is a J-banding dye.
Claim 12
Dependent Claim
19 words
The process of claim 1, characterized in that further sensitizing dye is added after the silver halide has formed.
Claim 13
Dependent Claim
25 words
The process of claim 1, characterized in that the spectrally sensitized silver halide grains are added to the dispersion of a long chain fatty acid.
Claim 14
Dependent Claim
25 words
The process of claim 4, characterized in that the spectrally sensitized silver halide grains are added to the dispersion of a long chain fatty acid.
Claim 15
Dependent Claim
29 words
The process of claim 1, characterized in that the spectrally sensitized silver halide grains are added to the ammonium or alkali metal salt of the long chain fatty acid.
Claim 16
Dependent Claim
26 words
The process of claim 7, characterized in that the spectrally sensitized silver halide grains are added to the silver salt of the long chain fatty acid.
Claim 17
Dependent Claim
37 words
The process of claim 1, characterized in that the emulsion of silver halide and silver salt of the acid is coated on a substrate with an organic reducing agent for silver ions, a toner and a binder.
Claim 18
Dependent Claim
37 words
A photothermographic material which comprises spectrally sensitized silver halide and a silver salt of a long chain fatty acid, characterized in that the silver halide was preformed in the presence of one or more spectral sensitizing dyes.
Claim 19
Dependent Claim
37 words
A photothermographic material which comprises spectrally sensitized silver halide and a silver salt of a long chain fatty acid, characterized in that the silver halide was preformed in the presence of one or more spectral sensitizing dyes.
Claim 20
Dependent Claim
21 words
A photothermographic material as claimed in claim 17, characterized in that the spectral sensitizing dye is a cyanine or merocyanine dye.
Claim 21
Dependent Claim
19 words
A photothermographic material as claimed in claim 18, characterized in that the spectral sensitizing dye is a J-banding dye.
Claim 22
Dependent Claim
41 words
A photothermographic material which comprises spectrally sensitized silver halide and a silver salt of a long chain fatty acid, characterized in that the silver halide is spectrally sensitized with a dye in a J-aggregate state in the absence of lithium iodide.
Claim 23
Dependent Claim
41 words
A photothermographic material which comprises spectrally sensitized silver halide and a silver salt of a long chain fatty acid, characterized in that the silver halide is spectrally sensitized with a dye in a J-aggregate state in the absence of lithium iodide.
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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) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |