US3773510A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Additives to bleach/fix baths
Assignee: 3M Co
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Filing: 1971-06-26
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Granted: 1973-11-20
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Expires: 1991-06-26
Abstract
Abstract In a bleach/fix bath for color photographic processing, said bath having a complexed or sequestered metal oxidizing agent as the bleaching agent, the improvement which comprises a water soluble ionic compound in which one of the ionic species is inorganic and contains at least one multivalent element at one of its higher valence states, which compound increases the oxidation potential of said bath by at least 30 millivolts in a quantity not in excess of 50 grams per liter without rendering said bath unstable.
Inventors
- 👤 R Fisch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:47
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/42; G03C7/421
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
15 words
The bleach/fix bath of claim 1 in which said multivalent element is a heavy metal.
Claim 2
Dependent Claim
13 words
The bleach/fix bath of claim 1 in which said multivalent element is chromium.
Claim 3
Dependent Claim
13 words
The bleach/fix bath of claim 1 in which said multivalent element is sulfur.
Claim 4
Dependent Claim
13 words
The bleach/fix bath of claim 1 in which said multivalent element is copper.
Claim 5
Dependent Claim
14 words
The bleach/fix bath of claim 1 in which said multivalent element is a halogen.
Claim 6
Dependent Claim
14 words
The bleach/fix bath of claim 1 in which said multivalent element is a nitrogen.
Claim 7
Dependent Claim
13 words
The bleach/fix bath of claim 1 in which said multivalent element is vanadium.
Claim 8
Dependent Claim
13 words
The bleach/fix bath of claim 1 in which said multivalent element is oxygen.
Claim 9
Dependent Claim
124 words
In a color photographic process including a development step in which an exposed silver halide image is developed with an aromatic primary amino developing agent in the presence of color coupler and a bleach/fix step in which a sequestered metal oxidizing agent is used as the bleaching agent, the improvement which comprises the use of a bleach fix bath having a pH above 4 and containing a water soluble ionic compound in which one of the ionic species is inorganic and contains at least one multivalent element at one of its higher valence states, which compound increases the oxidation potential of said bath by at least 30 milli-volts in a quantity not in excess of 50 grams per liter without rendering said bath unstable.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |