Patent US3342598A successfully refreshed from Google Patents.
US3342598A
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US
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Phosphorous and maleic acid buffers for ferricyanide photographic bleaches
Assignee: Eastman Kodak Co
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Filing: 1965-06-14
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Granted: 1967-09-19
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Expires: 1985-06-14
Abstract
No abstract record available.
Inventors
- 👤 Charleton C Bard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:14
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/42; G03C7/421; G03C5/00; G03C5/26; G03C5/40; G03C5/44
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
IN A PHOTOGRAPHIC PROCESS OF SILVER HALIDE COLOR PHOTOGRAPHY IN WHICH A SILVER IMAGE AND A COLOR IMAGE ARE PRODUCED BY COLOR DEVELOPMENT AND THEN SUBSEQUENTLY THE SAID SILVER IMAGE IS CONVERTED TO A SILVER SALT IMAGE BY A BLEACHING STEP AND THEN THE SAID SILVER SALT IMAGE IS REMOVED BY A FIXING STEP, THE IMPROVEMENT COMPRISING THE USE IN THE SAID BLEACHING STEP OF A BUFFERED BLEACH SOLUTION THAT IS STRONGLY BUFFERED IN THE 6 TO 7 PH RANGE WITH INCREASING BUFFER CPAPCITY AS THE PH IS FORCED TOWARD 6, SAID SOLUTION COMPRISING: (1) FROM ABOUT 5 TO ABOUT 200 GRAMS PER LITER OF A WATER-SOLUBLE FERRICYANIDE, AND (2) UP TO ABOUT 100 GRAMS PER LITER OF A BUFFER SELECTED FROM THE CLASS CONSISTING OF PHOSPHOROUS ACID, WATER-SOLUBLE SALTS OF PHOSPHORUS ACID, MALEIC ACID AND WATER-SOLUBLE SALTS OF MALEIC ACID.
Claim 2
Dependent Claim
141 words
IN A PHOTOGRAPHIC PROCESS OF SILVER HALIDE COLOR PHOTOGRAPHY IN WHICH A SILVER IMAGE AND A COLOR IMAGE ARE PRODUCED BY COLOR DEVELOPMENT AND THEN SUBSEQUENTLY THE SAID SILVER IMAGE IS CONVERTED TO A SILVER SALT IMAGE BY A BLEACHING STEP AND THEN THE SAID SILVER SALT IMAGE IS REMOVED BY A FIXING STEP, THE IMPROVEMENT COMPRISING THE USE IN THE SAID BLEACHING STEP OF A BUFFERED BLEACH SOLUTION THAT IS STRONGLY BUFFERED IN THE 6 TO 7 PH RANGE WITH INCREASING BUFFER CPAPCITY AS THE PH IS FORCED TOWARD 6, SAID SOLUTION COMPRISING: (1) FROM ABOUT 5 TO ABOUT 200 GRAMS PER LITER OF A WATER-SOLUBLE FERRICYANIDE, AND (2) UP TO ABOUT 100 GRAMS PER LITER OF A BUFFER SELECTED FROM THE CLASS CONSISTING OF PHOSPHOROUS ACID, WATER-SOLUBLE SALTS OF PHOSPHORUS ACID, MALEIC ACID AND WATER-SOLUBLE SALTS OF MALEIC ACID.
References Cited (Backward Citations)
US1950903A
Cited
US2943935A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-18 | 1971-03-20 | 1971-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-18 | 1975-03-20 | 1975-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-18 | 1979-03-20 | 1979-09-19 | $7700.00 | Window Closed / Lapsed |