US3776730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of an imagewise exposed and developed silver halide emulsion layer containing a catalase active or peroxide active catalyst with peroxide
Assignee: Agfa Gevaert AG
•
Filing: 1971-11-15
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Granted: 1973-12-04
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Expires: 1991-11-15
Abstract
Abstract A process for the production of positive photographic images comprising the steps of imagewise exposing a light-sensitive silver salt emulsion layer, photographically developing to form a negative silver image in the exposed areas, treating the exposed and developed layer with a peroxide compound, the peroxide compound is left to act on the layer until it has been decomposed at the negative silver image, and forming a positive image by decomposition of the undercomposed peroxide compound in the unexposed areas of the layer.
Inventors
- 👤 R Matejec
- 👤 R Meyer
- 👤 E Weyde
- 👤 F Moll
- 👤 E Ranz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:16
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/60; G03C5/26; G03C5/40; G03C5/50; Y; Y10; Y10S; Y10S430/00; Y10S430/144
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
16 words
The process of claim 1, wherein the exposed layer is treated with a fogging photographic developer.
Claim 2
Dependent Claim
28 words
The process of claim 1, wherein the silver halide emulsion layer contains at least one part by weight of silver halide per one part by weight of binder.
Claim 3
Dependent Claim
25 words
The process of claim 1, wherein the catalase active and/or peroxidase active catalysts are noble metals of Groups Ib or VIII of the Periodic Table.
Claim 4
Dependent Claim
29 words
The process of claim 1, wherein the catalase active and/or peroxidase active catalysts are complex compounds of heavy metals of Groups VIb, VIIb or VIII of the Periodic Table.
Claim 5
Dependent Claim
18 words
The process of claim 1, wherein the silver halide emulsion layer contains catalase active and/or peroxidase active enzymes.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |