US3926632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic silver halide lith material
Assignee: Agfa Gevaert NV
•
Filing: 1972-08-11
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Granted: 1975-12-16
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Expires: 1992-08-11
Abstract
Abstract A method is provided of producing high contrast images by development at a temperature above 30*C of an exposed photographic light-sensitive lith-material comprising a support having thereon at least one light-sensitive silver halide emulsion, which comprises at least 50 mole percent of silver chloride and at least 5 mole percent of silver bromide, wherein the said material comprises a disulphide compound of the formula:
Inventors
- 👤 Emiel Alexander Hofman
- 👤 Jules Robert Berendsen
- 👤 Robert Joseph Pollet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:27
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/34; G03C1/346; Y; Y10; Y10S; Y10S430/00; Y10S430/15
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
116 words
METHOD OF PRODUCING A HIGH CONTRAST IMATE BY DEVELOPMENT IN A DEVELOPER WHICH CONTAINS HYDROQUINONE OR A HYDROQUINONE DRIVATIVE HAVING A LOW SULPHITE ION CONTENT AND AT A TEMPERATURE ABOVE 30*C. OF AN EXPOSED PHOTOGRAPHIC LIGHTSENSITIVE LITHMATERIAL WHICH WILL PROVIDE A CHARACTERISTIC CURVE WITH A SHORT TOE AND HIGH GAMMA AND WHICH WILL PRODUCE SHARPLY DEFINED IMAGES WITH HIGH DENSITY EXTENDING TO THE EDGES OF LINES AND DOTS COMPRISING A SUPPORT HAVING THEREON AT LEAST ONE LIGHT-SENSITIVE HIGH CONTRAST SILVER HALIDE EMULSION HAVING A FINE GRAIN, WHICH COMPRISES AT LEAST 50 MOLE PERCENT OF SILVER CHLORIDE AND AT LEAST 5 MOLE PERCENT OF SILVER BROMIDE, WIEREIN THE SAID MATERIAL COMPRISES A DISULPHIDE COMPOUND OF THE FORMULA:
Claim 2
Dependent Claim
116 words
METHOD OF PRODUCING A HIGH CONTRAST IMATE BY DEVELOPMENT IN A DEVELOPER WHICH CONTAINS HYDROQUINONE OR A HYDROQUINONE DRIVATIVE HAVING A LOW SULPHITE ION CONTENT AND AT A TEMPERATURE ABOVE 30*C. OF AN EXPOSED PHOTOGRAPHIC LIGHTSENSITIVE LITHMATERIAL WHICH WILL PROVIDE A CHARACTERISTIC CURVE WITH A SHORT TOE AND HIGH GAMMA AND WHICH WILL PRODUCE SHARPLY DEFINED IMAGES WITH HIGH DENSITY EXTENDING TO THE EDGES OF LINES AND DOTS COMPRISING A SUPPORT HAVING THEREON AT LEAST ONE LIGHT-SENSITIVE HIGH CONTRAST SILVER HALIDE EMULSION HAVING A FINE GRAIN, WHICH COMPRISES AT LEAST 50 MOLE PERCENT OF SILVER CHLORIDE AND AT LEAST 5 MOLE PERCENT OF SILVER BROMIDE, WIEREIN THE SAID MATERIAL COMPRISES A DISULPHIDE COMPOUND OF THE FORMULA:
Claim 3
Dependent Claim
50 words
Method according to claim 1, wherein the said disulphide compound has the formula: X - A1 - S - S - A2 - Y wherein each of A1 and A2 stands for C1-C7 alkylene and each of X and Y stands for a water-solubilizing group in acid or salt form.
Claim 4
Dependent Claim
49 words
Method according to claim 1, wherein the said disulphide compound has the formula: X - A1 - S - S - A2 - Y wherein each of A1 and A2 stands for phenylene and each of X and Y stands for a water-solubilizing group in acid or salt form.
Claim 5
Dependent Claim
89 words
Method according to claim 1, wherein the said disulphide compound has the formula: X - A1 - S - S - A2 - Y wherein each of A1 and A2 stands for C1-C7 alkylene and each of X and Y stands for a substituent carrying a water-solubilizing group in acid or salt form, the said substituent being a bridging benzimidazolylene, alkylene carbamoyl, alkylene sulphamoyl, arylene carbamoyl, arylene sulphamoyl, alkylene amino, alkylene acylamino or arylene acylamino group between the water-solubilizing group and the alkylene groups represented by A1 and A2.
Claim 6
Dependent Claim
90 words
Method according to claim 1, wherein the said disulphide compound has the formula: X - A1 - S - S - A2 - Y wherein each of A1 and A2 is a phenylene group and each of X and Y stands for a substituent carrying a water-solubilizing gRoup in acid or salt form, the said substituent being a bridging alkyleneoxy, alkyleneoxycarbonyl, vinylene, alkyleneoxycarbonylvinyl, alkylene carbamoyl, alkylene sulphamoyl, arylene carbamoyl, arylene sylphamoyl, alkylene acylamino or arylene acylamino group between the water-solubilizing group and the phenylene groups represented by A1 and A2.
Claim 7
Dependent Claim
32 words
Method according to claim 1, wherein the said disulphide compound is present in the silver halide emulsion in an amount comprised between 5 mg. and 1000 mg per mole of silver halide.
Claim 8
Dependent Claim
14 words
Method according to claim 1, wherein the said material also comprises a polyoxyethylene compound.
Claim 9
Dependent Claim
31 words
Method according to claim 1, wherein the exposed material is developed in a lith-type developer, which comprises as the only developing agent hydroquinone and which comprises a low sulphite ion content.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |