EP0182658A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Photographic coupler dispersions
Assignee: Kodak Ltd
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Filing: 1985-11-20
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Granted: —
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Expires: 2005-11-20
Abstract
Abstract @ The dark stability of a photographic dye image formed by reaction between a coupler, dispersed in admixture with an involatile solvent, and oxidized p-phenylenediamine colour developing agent is impaired by the presence of a compound comprising a phenolic (or naphtholic moiety in which the acidity of the phenolic hydroxyl group is enhanced by at least one electron-withdrawing substituent in ortho and/or para positions relative to that group. Such a compound may be the coupler itself of the involatile solvent used for its incorporation. This loss in stability can be reduced by introducing into the dispersion a lipophilic anionic surfactant which comprises a sulphate or sulphonate group as the sole hydrophilic group and either a single aliphatic hydrocarbon group having at least 1 carbon atoms or two or more aliphatic hydrocarbon groups which together contain at least 17 carbon atoms. A conventional, i.e. less lipophilic, anionic surfactant may also be used in preparing the coupler dispersion.
Inventors
- 👤 Michael J. Dr. Simons
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 12:08
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/388; G03C7/3885
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
131 words
A method of making a photographic coupler disperion by dispersing a mixture containing the coupler and an oil-former in an aqueous hydrophilic colloid solution in the presence of an anionic surfactant, the coupler and/or the oil-former comprising a phenolic or naphtholic moiety of which the acidity is enhanced by the presence of at least one electron-withdrawing group at a position ortho or para to the phenolic hydroxyl group, wherein there is added at any stage a anionic surfactant which comprises a sulphate or sulphonate group as the sole hydrophilic group and either a single aliphatic hydrocarbon group having at least 15 carbon atoms or two or more aliphatic hydrocarbon groups which together contain at least 17 carbon atoms (hereafter called the lipophilic anionic surfactant), but wherein no non-ionic surfactant is used.
Claim 2
Independent Claim
131 words
A method of making a photographic coupler disperion by dispersing a mixture containing the coupler and an oil-former in an aqueous hydrophilic colloid solution in the presence of an anionic surfactant, the coupler and/or the oil-former comprising a phenolic or naphtholic moiety of which the acidity is enhanced by the presence of at least one electron-withdrawing group at a position ortho or para to the phenolic hydroxyl group, wherein there is added at any stage a anionic surfactant which comprises a sulphate or sulphonate group as the sole hydrophilic group and either a single aliphatic hydrocarbon group having at least 15 carbon atoms or two or more aliphatic hydrocarbon groups which together contain at least 17 carbon atoms (hereafter called the lipophilic anionic surfactant), but wherein no non-ionic surfactant is used.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein the lipophilic anionic surfactant is an alkylphenol sulphonate or a dialkylsulphosuccinate.
Claim 4
Independent Claim
29 words
A method according to either of the preceding claims wherein the anionic surfactant present during the dispersion step comprises a surfactant less lipophilic than the specified lipophilic anionic surfactant.
Claim 5
Independent Claim
20 words
A method according to any of the preceding claims wherein the lipophilic anionic surfactant is added before the dispersion step.
Claim 6
Independent Claim
20 words
A method according to any of the preceding claims wherein the coupler is a phenolic or naphtholic cyan dye-forming coupler.
Claim 7
Independent Claim
22 words
A method according to any of the preceding claims wherein the coupler solvent comprises a phenolic or naphtholic moiety of enhanced acidity.
Claim 8
Independent Claim
36 words
A method according to any of the preceding claims wherein the compound comprising a phenolic or naphtholic moiety of enhanced acidity, or mixture of such compounds, constitutes at least 5t by weight of the dispersed substances.
Claim 9
Independent Claim
24 words
A method according to any of the preceding claims wherein the total lipophilic surfactant constitutes at least 1% by weight of the dispersed substances.
Claim 10
Dependent Claim
15 words
A dye-forming coupler dispersion made by a method according to any of the preceding claims.
Claim 11
Dependent Claim
37 words
A sensitive photographic material comprising a support bearing a photographic hydrophilic colloid- silver halide emulsion layer and, dispersed in that layer or in a hydrophilic colloid layer adjacent thereto a dye-forming coupler dispersion according to claim 9.
Claim 12
Dependent Claim
134 words
A sensitive photographic material which comprises a support bearing a photographic hydrophilic colloid - a silver halide emulsion layer and, dispersed in that layer or in a hydrophilic colloid layer adjacent thereto, a water-insoluble dye-forming coupler, a water-immiscible solvent therefor, and a dispersing agent for the coupler-coupler solvent mixture, the coupler and/or the solvent comprising a phenolic or naphtholic moiety of which the acidity is increased by an electron-withdrawing group at the o or p-position relative to the phenolic hydroxyl group and the dispersing agent containing a lipophilic anionic surfactant which comprises a sulphate or sulphonate group as the sole hydrophilic group and either a single aliphatic hydrocarbon group having at least 15 carbon atoms or two or more aliphatic hydrocarbon groups which together contain at least 17 carbon atoms but no non-ionic surfactant.
Claim 13
Dependent Claim
134 words
A sensitive photographic material which comprises a support bearing a photographic hydrophilic colloid - a silver halide emulsion layer and, dispersed in that layer or in a hydrophilic colloid layer adjacent thereto, a water-insoluble dye-forming coupler, a water-immiscible solvent therefor, and a dispersing agent for the coupler-coupler solvent mixture, the coupler and/or the solvent comprising a phenolic or naphtholic moiety of which the acidity is increased by an electron-withdrawing group at the o or p-position relative to the phenolic hydroxyl group and the dispersing agent containing a lipophilic anionic surfactant which comprises a sulphate or sulphonate group as the sole hydrophilic group and either a single aliphatic hydrocarbon group having at least 15 carbon atoms or two or more aliphatic hydrocarbon groups which together contain at least 17 carbon atoms but no non-ionic surfactant.
Claim 14
Dependent Claim
19 words
A material according to claim 11 wherein the surfactant is an alkanesulphonate, an alkylphenyl sulphonate or a dialkyl sulphosuccinate.
Claim 15
Dependent Claim
44 words
A material according to claim 11 or 12 wherein the dispersing agent also comprises an anionic surfactant which contains an aliphatic hydrocarbon group having fewer than 15 carbon atoms or two or more aliphatic hydrocarbon groups which together contain fewer than 17 carbon atoms.
References Cited (Backward Citations)
No citation records indexed.
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