US5688635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toning of photographic print material
Assignee: Ilford Imaging UK Ltd
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Filing: 1996-05-06
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Granted: 1997-11-18
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Expires: 2016-05-06
Abstract
Abstract There is described a photographic developing solution which comprises as an image toning agent a compound of formula I: <IMAGE> where Ar is an aromatic or heteroaromatic ring which may be substituted, in a concentration of at least 0.00035 moles/liter.
Inventors
- 👤 Michael John Parker
- 👤 Anthony Martin Lannon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:20
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/305; G03C5/40; G03C5/46
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
63 words
A photographic developing solution which is characterised in that it comprises as an image toning agent a compound of formula I: ##STR8## where Ar is a phenyl ring which is substituted with a water solubilizing group selected from the group consisting essentially of a carboxylic acid group, a sulphonic acid group or a salt thereof, in a concentration of at least 0.00035 moles/liter.
Claim 2
Dependent Claim
63 words
A photographic developing solution which is characterised in that it comprises as an image toning agent a compound of formula I: ##STR8## where Ar is a phenyl ring which is substituted with a water solubilizing group selected from the group consisting essentially of a carboxylic acid group, a sulphonic acid group or a salt thereof, in a concentration of at least 0.00035 moles/liter.
Claim 3
Dependent Claim
19 words
A photographic developing solution according to claim 1 wherein the compound of formula I is of formula II: ##STR9##
Claim 4
Dependent Claim
22 words
A photographic developing solution according to claim 1 wherein the main developing agent in the solution is a dihydroxybenzene type developing agent.
Claim 5
Dependent Claim
22 words
A photographic developing solution according to claim 1 wherein the main developing agent in the solution is a reductone type developing agent.
Claim 6
Dependent Claim
27 words
A photographic developing solution according to claim 4 wherein the reductone type developing agent is L-ascorbic acid, D-isoascorbic acid or L-erythroascorbic acid or salts of such compounds.
Claim 7
Dependent Claim
30 words
A photographic developing solution according to claim 3 wherein the amount of the dihydroxybenzene type developing agent present in the working strength developing solution is from 1 to 15 g/liter.
Claim 8
Dependent Claim
21 words
A photographic developing solution according to claim 1 wherein there is also present in the developing solution an electron transfer agent.
Claim 9
Dependent Claim
57 words
A photographic developing solution according to claim 7 wherein the electron transfer agent is metol or a pyrazolidinone compound of the general formula V: ##STR10## in which R 5 is an aromatic ring; R 1 and R 2 are hydrogen, lower alkyl, or hydroxy alkyl, and R 3 and R 4 are hydrogen, lower alkyl or phenyl.
Claim 10
Dependent Claim
27 words
A photographic developing solution according to claim 1 wherein the amount of the compound of formula I present in the solution is from 0.1 to 0.5 g/liter.
Claim 11
Dependent Claim
60 words
A photographic developing solution according to claim 9 for roller transport machine processing wherein the amount of compound of formula I present in the solution is from 0.2 to 0.6 g/liter, the amount of hydroquinone is from 4 to 12 g/liter, and the amount of electron transfer agent compound B is from 0.2 to 2.0 g/liter, together with a base.
Claim 12
Dependent Claim
58 words
A photographic developing solution according to claim 9, for dish processing, wherein the amount of compound of formula I present in the solution is from 0.1 to 0.2 g/liter, the amount of hydroquinone is from 2 to 5 g/liter, and the amount of electron transfer agent compound B is from 0.1 to 1.5 g/liter, together with a base.
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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) | 2000-11-17 | 2001-05-19 | 2001-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-17 | 2005-05-19 | 2005-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-17 | 2009-05-19 | 2009-11-18 | $7700.00 | Window Closed / Lapsed |