US5372911A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of forming super high-contrast negative images and silver halide photographic material and developer being used therefor
Assignee: DIC Corp
•
Filing: 1992-06-11
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Granted: 1994-12-13
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Expires: 2012-06-11
Abstract
Abstract A process of forming a super high-contrast negative image is disclosed, which comprises the steps of imagewise exposing a negative-working silver halide photographic material comprising a support having thereon one or more hydrophilic colloidal layers, at least one of the one or more hydrophilic colloidal layers being a negative-working silver halide emulsion layer, and then developing the photographic material with a developer containing an aminophenol derivative developing agent and a reductone compound in the existence of an organic compound having a negative reduction potential. A negative-working silver halide photographic material and a photographic developer being used for the image-forming process are also disclosed.
Inventors
- 👤 Naoki Obi
- 👤 Yasuhiko Kojima
- 👤 Yasuo Shigemitsu
- 👤 Jun Takeuchi
- 👤 Kiyoshi Suematsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:17
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/067; G03C5/00; G03C5/26; G03C5/29; G03C5/30
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
143 words
A negative-working silver halide photographic material for forming a very high contrast negative image comprising a support having thereon one or more hydrophilic colloidal layers, at least one of said one or more hydrophilic colloidal layers being a negative-working silver halide emulsion layer, wherein at least one layer of said one or more hydrophilic colloidal layers contains an organic compound selected from the group consisting of a pyridinium salt or a derivative thereof, a quinoliniuam salt or a derivative thereof, and an isoquinolinium salt or a derivative thereof, said organic compound having a reduction potential more negative than -0.6 volt and being present in an amount of 1×10 -4 to 1×10 -2 mol per mol of silver halide and effective to increase contrast to 10 or higher in gamma, and said material being essentially free of sensitizing dyes having an effect on gamma.
Claim 2
Dependent Claim
143 words
A negative-working silver halide photographic material for forming a very high contrast negative image comprising a support having thereon one or more hydrophilic colloidal layers, at least one of said one or more hydrophilic colloidal layers being a negative-working silver halide emulsion layer, wherein at least one layer of said one or more hydrophilic colloidal layers contains an organic compound selected from the group consisting of a pyridinium salt or a derivative thereof, a quinoliniuam salt or a derivative thereof, and an isoquinolinium salt or a derivative thereof, said organic compound having a reduction potential more negative than -0.6 volt and being present in an amount of 1×10 -4 to 1×10 -2 mol per mol of silver halide and effective to increase contrast to 10 or higher in gamma, and said material being essentially free of sensitizing dyes having an effect on gamma.
Claim 3
Dependent Claim
26 words
The negative-working silver halide photographic material of claim 1, wherein said one or more hydrophilic colloidal layers further contain a polyalkylene oxide or the derivative thereof.
Claim 4
Dependent Claim
34 words
The negative-working silver halide photographic material of claim 1, wherein said one or more hydrophilic colloidal layers further contain an inorganic or organic compound having an acidic dissociation constant pKa of lower than 11.
Claim 5
Dependent Claim
22 words
The negative-working silver halide photographic material of claim 1 wherein said organic compound has a reduction potential more negative than -0.80 volt.
Claim 6
Dependent Claim
178 words
A negative-working silver halide photographic material for forming a very high contrast negative image comprising a support having thereon one or more hydrophilic colloidal layers, at least one of said one or more hydrophilic colloidal layers being a negative-working silver halide emulsion layer, wherein at least one layer of said one or more hydrophilic colloidal layers contains an organic compound selected from the group consisting of a pyridinium salt or a derivative thereof, a quinolinium salt or a derivative thereof, and an isoquinolinium salt or derivative thereof, said organic compound having a reduction potential more negative than -0.6 volt and being present in an amount of 1×10 -5 to 1×10 -3 mol per mol of silver halide and effective to increase contrast to 10 or higher in gamma, and said material being essentially free of sensitizing dyes having an effect on gamma; and wherein said at least one layer of said one or more hydrophilic colloidal layers optionally contains a polyalkylene oxide or derivative thereof in an amount of 0.1 to 10 gm per mol of silver halide.
Claim 7
Dependent Claim
178 words
A negative-working silver halide photographic material for forming a very high contrast negative image comprising a support having thereon one or more hydrophilic colloidal layers, at least one of said one or more hydrophilic colloidal layers being a negative-working silver halide emulsion layer, wherein at least one layer of said one or more hydrophilic colloidal layers contains an organic compound selected from the group consisting of a pyridinium salt or a derivative thereof, a quinolinium salt or a derivative thereof, and an isoquinolinium salt or derivative thereof, said organic compound having a reduction potential more negative than -0.6 volt and being present in an amount of 1×10 -5 to 1×10 -3 mol per mol of silver halide and effective to increase contrast to 10 or higher in gamma, and said material being essentially free of sensitizing dyes having an effect on gamma; and wherein said at least one layer of said one or more hydrophilic colloidal layers optionally contains a polyalkylene oxide or derivative thereof in an amount of 0.1 to 10 gm per mol of silver halide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-12-12 | 1998-06-13 | 1998-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-12 | 2002-06-13 | 2002-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-12 | 2006-06-13 | 2006-12-13 | $7700.00 | Window Closed / Lapsed |