US2967772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic tanning developer
Assignee: Gevaert Photo Producten NV
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Filing: 1958-09-02
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Granted: 1961-01-10
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Expires: 1978-09-02
Abstract
No abstract record available.
Inventors
- 👤 Willems Jozef Frans
- 👤 Albert Emiel Van Hoof
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:28
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/315
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
62 words
A PHOTOGRAPHIC TANNING DEVELOPER SOLUTION HAVING REDUCED TENDENCY TO AERIAL OXIDATION AND CAPABLE OF FORMING RELIEF IMAGES UPON DEVELOPMENT OF AN EXPOSED SILVER HALIDE EMULSION, COMPRISING AN ALKALINE SOLUTION OF A POLYHYDROXYBENZENE SELECTED FROM THE GROUP CONSISTING OF PYROGALLOL AND PYROCATECHOL AND A WATER-SOLUBLE SALT OF A BORON ASCORBIC ACID COMPOUND WHICH IS THE REACTION PRODUCT OF BORIC ACID AND ASCORBIC ACID.
Claim 2
Dependent Claim
62 words
A PHOTOGRAPHIC TANNING DEVELOPER SOLUTION HAVING REDUCED TENDENCY TO AERIAL OXIDATION AND CAPABLE OF FORMING RELIEF IMAGES UPON DEVELOPMENT OF AN EXPOSED SILVER HALIDE EMULSION, COMPRISING AN ALKALINE SOLUTION OF A POLYHYDROXYBENZENE SELECTED FROM THE GROUP CONSISTING OF PYROGALLOL AND PYROCATECHOL AND A WATER-SOLUBLE SALT OF A BORON ASCORBIC ACID COMPOUND WHICH IS THE REACTION PRODUCT OF BORIC ACID AND ASCORBIC ACID.
References Cited (Backward Citations)
US2635102A
Cited
US2816026A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-01-10 | 1964-07-11 | 1965-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-01-10 | 1968-07-11 | 1969-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-01-10 | 1972-07-11 | 1973-01-10 | $7700.00 | Window Closed / Lapsed |