US5210010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silver halide developing solutions
Assignee: UBS AG
•
Filing: 1992-04-30
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Granted: 1993-05-11
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Expires: 2012-04-30
Abstract
Abstract There is described a concentrated developer solution which comprises from about 20 to about 60 g/l of dihydroxybenzene developing agent, preferably hydroquinone, from about 0.5 to about 3.0 g/l of an auxiliary developing agent, preferably 1-phenyl-3 pyrazolidinone, from about 300 to about 500 g/l of potassium sulphite and which is buffered to a pH of from about 8 to about 10 with a buffering agent other than an alkanolamine and which comprises sufficient organic solvent other than an alkanolamine to dissolve the hydroquinone. Such a concentrated developing solution which contains a high concentration of potassium sulphite has when diluted a long useful life and produces images of low graininess.
Inventors
- 👤 Ross Fielding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:06
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/264; G03C5/266
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
75 words
A concentrated developer solution which comprises from about 20 to about 60 g/l of a dihydroxybenzene, from about 0.5 to about 3.0 g/l of an auxiliary developing agent, from about 300 to about 500 g/l of potassium sulphite and which is buffered to a pH of from about 8 to about 10 with a buffering agent other than an alkanolamine and which comprises an organic solvent other than an alkanolamine sufficient to dissolve the dihydroxybenzene.
Claim 2
Dependent Claim
75 words
A concentrated developer solution which comprises from about 20 to about 60 g/l of a dihydroxybenzene, from about 0.5 to about 3.0 g/l of an auxiliary developing agent, from about 300 to about 500 g/l of potassium sulphite and which is buffered to a pH of from about 8 to about 10 with a buffering agent other than an alkanolamine and which comprises an organic solvent other than an alkanolamine sufficient to dissolve the dihydroxybenzene.
Claim 3
Dependent Claim
21 words
A concentrated developer solution according to claim 1 wherein said dihydroxybenzene is hydroquinone and said auxiliary developing agent is a 1-phenyl-3-pyrazolidone.
Claim 4
Dependent Claim
18 words
A concentrated developer solution according to claim 2 which comprises about 40 to about 50 g/l of hydroquinone.
Claim 5
Dependent Claim
20 words
A concentrated developer solution according to claim 2 which comprises from about 0.5 to about 1.5 g/l of the 1-phenyl-3-pyrazolidinone.
Claim 6
Dependent Claim
13 words
A concentrated developer solution according to claim 2 wherein the 1-phenyl-3-pyrazolidinone is 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone.
Claim 7
Dependent Claim
14 words
A concentrated developer solution according to claim 1 which comprises borax as buffering agent.
Claim 8
Dependent Claim
15 words
A concentrated developer solution according to claim 1 which comprises as the organic solvent digol.
Claim 9
Dependent Claim
20 words
A concentrated developer solution according to claim 1 which comprises from about 300 to about 400 g/l of potassium sulphite.
Claim 10
Dependent Claim
14 words
A concentrated developer solution according to claim 1 which also comprises a sequestering agent.
Claim 11
Dependent Claim
14 words
A concentrated developer solution according to claim 9 wherein the sequestering agent is DTPA.
Claim 12
Dependent Claim
28 words
The solution of claim 1 wherein said buffering agent comprises borax and said solvent comprises a member selected from the group consisting of digol, trigol and ethylene glycol.
Claim 13
Dependent Claim
28 words
The solution of claim 2 wherein said buffering agent comprises borax and said solvent comprises a member selected from the group consisting of digol, trigol and ethylene glycol.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-10 | 1996-11-09 | 1997-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-10 | 2000-11-09 | 2001-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-10 | 2004-11-09 | 2005-05-11 | $7700.00 | Window Closed / Lapsed |