Patent US3770437A successfully refreshed from Google Patents.
US3770437A
Expired / Lapsed
US
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Photographic bleach compositions
Assignee: Individual
•
Filing: 1972-04-06
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Granted: 1973-11-06
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Expires: 1992-04-06
Abstract
Abstract The incorporation of bromate ion into photographic bleach compositions which include trivalent iron complexes of aminopolycarboxylic acid as the bleaching agent inhibits the formation of leuco cyan dyes when these bleaches are used in the processing of incorporated coupler reversal emulsions.
Inventors
- 👤 D Brugger
- 👤 B Hagenbuch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:27
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/42; G03C7/421
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
47 words
The photographic bleach composition of claim 1 wherein the concentration of said salt ranges from about 1 to about 350 grams per liter when said salt is an iodide salt and from about 50 to about 350 grams per liter when said salt is a bromide salt.
Claim 2
Dependent Claim
27 words
The composition of claim 2 wherein said trivalent iron complex is selected from the group consisting of alkali metal and ammonium ferric complexes of an aminopolycarboxylic acid.
Claim 3
Dependent Claim
34 words
The composition of claim 3 wherein said trivalent iron complex is an ammonium ferric ethylenediamine tetraacetate said bromate is sodium bromate and the pH of said composition ranges from about 4 to about 6.5.
Claim 4
Dependent Claim
31 words
The composition of claim 4 wherein said bromide salt is ammonium bromide, said iodide salt is potassium iodide and the pH of said composition is about 5 + or - .5.
Claim 5
Dependent Claim
141 words
In a photographic color reproduction process wherein a plurality of superposed differently sensitized silver halide emulsion layers are developed with a p-phenylene-diamine developer to produce silver and dye images in the layers, the silver is bleached to form a silver complex soluble in a fixing solution and the emulsion layers are fixed with a fixing solution, the improvement comprising bleaching the silver with a solution comprising from about 10 to about 400 grams per liter of a trivalent iron complex of an aminopoly-carboxylic acid, a member selected from the group consisting of alkali metal and ammonium bromide and iodide salts and mixtures of said salts and from about 5 to about 50 grams per liter of a member selected from the group consisting of alkali metal and ammonium bromates, said bleach solution having a pH of between about 2 and 8.
Claim 6
Dependent Claim
46 words
The process according to claim 6 wherein the concentration of said salt ranges from about 1 to about 350 grams per liter when said salt is an iodide salt and from about 50 to about 350 grams per liter when said salt is a bromide salt.
Claim 7
Dependent Claim
28 words
The process according to claim 7 wherein the trivalent iron complex is selected from the group consisting of alkali metal and ammonium ferric complexes of an aminopolycarboxylic acid.
Claim 8
Dependent Claim
39 words
The process according to claim 7 wherein the emulsion layers in a color reversal process are first developed with a black and white developer and then with color developer prior to bleaching the silver with the trivalent iron complex.
Claim 9
Dependent Claim
24 words
The process according to claim 7 wherein said trivalent iron complex is selected from the group consisting of sodium and ammonium ferric ethylenediamine tetraacetate.
Claim 10
Dependent Claim
36 words
The process according to claim 10 wherein said trivalent iron complex is an ammonium ferric ethylenediamine tetraacetate said bromate is sodium bromate and the pH of said bleach solution ranges from about 4 to about 6.5.
Claim 11
Dependent Claim
33 words
The process according to claim 11 wherein said bromide salt is ammonium bromide, said iodide salt is potassium iodide and the pH of said bleach solution is about 5 + or - .5.
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) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |