Patent US3655382A successfully refreshed from Google Patents.
US3655382A
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US
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Processes for converting zero-valent metals photographic images to formazan dye images
Assignee: Eastman Kodak Co
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Filing: 1970-02-25
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Granted: 1972-04-11
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Expires: 1990-02-25
Abstract
Abstract A zero valent metal image in which the metal has a standard oxidation potential more positive than -0.98 volt is advantageously converted to a nondiffusible formazan dye image by the single process step of contacting the metal image with a solution of a tetrazolium salt that contains a metal complexing moiety when the combination of tetrazolium salt, metal and water produces a solution reaction potential E of at least +0.01 volt.
Inventors
- 👤 Albert T Brault
- 👤 Vernon L Bissonette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:21
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/40; G03C5/46; C; C09; C09B; C09B50/00; C09B50/02; G03C5/56
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
84 words
A process for converting at least a part of a zero valent metal image to a formazan dye image by the step of contacting said metal image with an aqueous solution containing a water-soluble, diffusible tetrazolium salt which has at least one moiety that is a metal ion complexing agent, such that the combination of said metal and said tetrazolium salt in the presence of water produces a solution reaction potential of at least +0.01 volt, said tetrazolium salt being represented by the formulas:
Claim 2
Dependent Claim
9 words
washing in water to remove residual tetrazolium salt solution,
Claim 3
Dependent Claim
17 words
reforming said metal image by converting said complexed metal ion image to a corresponding metal image, and
Claim 4
Dependent Claim
14 words
A process of claim 1 in which said metal image is a silver image.
Claim 5
Dependent Claim
14 words
A process of claim 2 in which said metal image is a silver image.
Claim 6
Dependent Claim
96 words
contacting said reformed metal image with an aqueous solution containing a water-soluble, diffusible tetrazolium salt which has at least one moiety that is a metal ion complexing agent such that the combination of said metal and said tetrazolium salt in the presence of water produces a solution reaction potential of at least +0.01 volt, so said reformed metal image is oxidized to the corresponding metal ion complex and said tetrazolium salt that oxidized said reformed metal image is reduced to a corresponding formazan dye image thus increasing the formazan dye image density formed in step 1.
Claim 7
Dependent Claim
83 words
A process for converting at least a part of a zero valent metal image to a formazan dye image by the step of contacting said metal image with an aqueous solution containing a water-soluble, diffusible tetrazolium salt which has at least one moiety that is a metal ion complexing agent, that the combination of said metal and said tetrazolium salt in the presence of water produces a solution reaction potential of at least +0.01 volt, said tetrazolium salt being represented by the formulas:
Claim 8
Dependent Claim
13 words
A process of claim 5 in which the tetrazolium salt has the formula:
Claim 9
Dependent Claim
32 words
A process for converting a silver image in a hydrophilic colloid layer to a formazan dye image comprising the step of contacting said metal image with an aqueous solution of 2-(benzothiazol-2-yl)-5-(2-chlorophenyl)-3-phenyl-2H-tetrazolium bromide.
Claim 10
Dependent Claim
32 words
A process for converting a silver image in a hydrophilic colloid layer to a formazan dye image comprising the step of contacting said metal image with an aqueous solution of 2-(benzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2H-tetrazolium bromide.
Claim 11
Dependent Claim
33 words
A process for converting a silver image in a hydrophilic colloid layer to a formazan dye image comprising the step of contacting said metal image with an aqueous solution of 2-(benzOthiazol-2-yl)-5-(4-acetamidophenyl)-3-(4-phenylazolphenyl)-2H -tetrazolium bromide.
Claim 12
Dependent Claim
32 words
A process for converting a silver image in a hydrophilic colloid layer to a formazan dye image comprising the step of contacting said metal image with an aqueous solution of 2-(4,5-dimethylthiazol-2-yl)-3,5-diphenyl-2H-tetrazolium bromide.
Claim 13
Dependent Claim
22 words
A process for converting a metal image to a formazan dye image having a substantially higher image density, comprising the steps of:
References Cited (Backward Citations)
GB670883A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |