US5474879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiographic film developers containing ascorbic acid and thioether development accelerators
Assignee: Carestream Health Inc
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Filing: 1995-01-30
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Granted: 1995-12-12
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Expires: 2015-01-30
Abstract
Abstract An alkaline, hydroquinone free, aqueous black-and-white radiographic developer comprising (a) an ascorbic acid developing agent; (b) a 3-pyrazolidone auxiliary developing agent; (c) an organic antifoggant; (d) a sulfite antioxidant; (e) a buffer; (f) a sequestering agent; and (g) A development accelerator selected from formulas I and II as follows: ##STR1## wherein R 1 , R 2 , and R 3 represent alkyl of 1 to 8 carbon atoms or R 1 , R 2 , and R 3 taken together with N atom to which they are attached form a 6 or 7 membered ring and X represents a tosylate ion, halide, or BF 4 - .
Inventors
- 👤 Alan S. Fitterman
- 👤 Joan F. Rachel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:16
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/305
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
107 words
An alkaline, hydroquinone free, aqueous black-and-white radiographic developer comprising (a) an ascorbic acid developing agent; (b) a 3-pyrazolidone auxiliary developing agent; (c) an organic antifoggant; (d) a sulfite antioxidant; (e) a buffer; (f) a sequestering agent; and (g) A development accelerator selected from formulas I and II as follows: ##STR7## wherein R 1 , R 2 , and R 3 represent alkyl of 1 to 8 carbon atoms or R 1 , R 2 , and R 3 taken together with N atom to which they are attached form a 6 or 7 membered ring and X represents a tosylate ion, halide, or BF 4 - .
Claim 2
Dependent Claim
107 words
An alkaline, hydroquinone free, aqueous black-and-white radiographic developer comprising (a) an ascorbic acid developing agent; (b) a 3-pyrazolidone auxiliary developing agent; (c) an organic antifoggant; (d) a sulfite antioxidant; (e) a buffer; (f) a sequestering agent; and (g) A development accelerator selected from formulas I and II as follows: ##STR7## wherein R 1 , R 2 , and R 3 represent alkyl of 1 to 8 carbon atoms or R 1 , R 2 , and R 3 taken together with N atom to which they are attached form a 6 or 7 membered ring and X represents a tosylate ion, halide, or BF 4 - .
Claim 3
Dependent Claim
16 words
The developer of claim 1 wherein the development accelerator is ##STR8## and X - represents tosylate.
Claim 4
Dependent Claim
17 words
The developer of claim 1 wherein the development accelerator is ##STR9## wherein X represents a tosylate ion.
Claim 5
Dependent Claim
60 words
The developer of claim 1, 2 or 3 wherein the ascorbic acid developing agent is selected from the group consisting of L-ascorbic acid, D-ascorbic acid, L-erythroascorbic acid, D-glucoascorbic acid, 6-desoxy-L-ascorbic acid, L-rhamnoascorbic acid, D-glucoheptoascorbic acid, D-glucoheptoascorbic acid, imino-L-erythroascorbic acid, imino-D-glucoascorbic acid, imino-6-desoxy-L-ascorbic acid, imino-D-glucoheptoascorbic acid, sodium isoascorbate, L-glycoascorbic acid, D-galactoascorbic acid, L-araboascorbic acid, sorboascorbic acid, sodium ascorbate and the like.
Claim 6
Dependent Claim
15 words
The developer of claim 1, 2 or 3 wherein the developing agent is ascorbic acid.
Claim 7
Dependent Claim
13 words
The developer of claim 5 wherein having a pH from 9 to 11.
Claim 8
Dependent Claim
31 words
The developer of claim 5 wherein the organic antifoggant is selected from the group consisting of 5-nitroindazole, 5-p-nitrobenzoylaminoindazole, 1-methyl-5-nitroindazole, 6-nitroindazole, 3-methyl-5-nitroindazole, 5-nitrobenzimidazole, 2-isopropyl-5-nitrobenzimidazole, 5-nitrobenzotriazole, sodium 4-(2-mercapto-1,3,4-thiadiazol-2-yl-thio)butanesulfonate, 5-amino-1,3,4-thiadiazole-2-thiol, 5-methylbenzotriazole, 1-phenyl-5-mercaptotetrazole, and benztriazole.
Claim 9
Dependent Claim
31 words
The developer of claim 5 wherein the auxiliary developing agent is selected from the group consisting of 4-hydroxylmethyl-4-methyl-1-phenyl-3-pyrazolidinone, 1-phenyl-3-pyrazolidinone, 1-phenyl-4-phenyl-3-pyrazolidinone, 1-phenyl-4,4-dimethyl-3-pyrazolidinone, 1-phenyl-4-methyl-3-pyrazolidinone, 1-phenyl-5-methyl-3-pyrazolidinone, 4-methyl-1-phenyl-3-pyrazolidinone, 4,4'-dimethyl-1-phenyl-3-pyrazolidinone, o-aminophenol, p-aminophenol, N-methyl-p-aminophenol, N-methyl-o-aminophenol, and 2,4-diaminophenol.
Claim 10
Dependent Claim
22 words
The developer of claim 5 wherein said sulfite antioxidant is selected from the group consisting of sulfites, bisulfites, metabisulfites, and aldehyde-bisulfite adducts.
Claim 11
Dependent Claim
23 words
The developer of claim 2 or 3 further comprising ascorbic acid, potassium sulfite, potassium carbonate, 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone, 1-phenyl-5-mercaptotetrazole, benzotriazole, diethylenetriaminepetaacetic acid and potassium bromide.
Claim 12
Dependent Claim
30 words
The developer of claim 1, 2 or 3 comprising from 0.01 to 0.40 weight percent of the development accelerator and from 0.8 to 4 weight percent ascorbic acid developing agent.
Claim 13
Dependent Claim
26 words
A method for developing exposed silver halide photographic material, said method comprising developing said photographic material with an alkaline, aqueous radiographic developer according to claim 1.
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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) | 1998-12-11 | 1999-06-12 | 1999-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-11 | 2003-06-12 | 2003-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-11 | 2007-06-12 | 2007-12-12 | $7700.00 | Window Closed / Lapsed |