US3264107A - Baths suitable for rehalogenating metallic silver in photographic materials - Google Patents
Baths suitable for rehalogenating metallic silver in photographic materials Download PDFInfo
- Publication number
- US3264107A US3264107A US220156A US22015662A US3264107A US 3264107 A US3264107 A US 3264107A US 220156 A US220156 A US 220156A US 22015662 A US22015662 A US 22015662A US 3264107 A US3264107 A US 3264107A
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- US
- United States
- Prior art keywords
- bath
- silver
- acid
- rehalogenating
- metallic silver
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- 229910052709 silver Inorganic materials 0.000 title claims description 54
- 239000004332 silver Substances 0.000 title claims description 54
- 239000000463 material Substances 0.000 title claims description 23
- 239000002253 acid Substances 0.000 claims description 29
- 150000003839 salts Chemical class 0.000 claims description 15
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 11
- 150000007933 aliphatic carboxylic acids Chemical class 0.000 claims description 11
- 229910001413 alkali metal ion Inorganic materials 0.000 claims description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical class [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims description 5
- 239000001257 hydrogen Substances 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 49
- 238000004061 bleaching Methods 0.000 description 22
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 15
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 15
- 239000000975 dye Substances 0.000 description 12
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 11
- 239000010410 layer Substances 0.000 description 11
- 238000000034 method Methods 0.000 description 11
- 150000007513 acids Chemical class 0.000 description 10
- 230000008569 process Effects 0.000 description 9
- -1 silver halide Chemical class 0.000 description 8
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 7
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 6
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- 239000004094 surface-active agent Substances 0.000 description 6
- 239000000839 emulsion Substances 0.000 description 5
- 238000011282 treatment Methods 0.000 description 5
- 239000002585 base Substances 0.000 description 4
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 description 4
- 229940123208 Biguanide Drugs 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 150000001879 copper Chemical class 0.000 description 3
- 229910000365 copper sulfate Inorganic materials 0.000 description 3
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- ADZWSOLPGZMUMY-UHFFFAOYSA-M silver bromide Chemical compound [Ag]Br ADZWSOLPGZMUMY-UHFFFAOYSA-M 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- XNCOSPRUTUOJCJ-UHFFFAOYSA-N Biguanide Chemical compound NC(N)=NC(N)=N XNCOSPRUTUOJCJ-UHFFFAOYSA-N 0.000 description 2
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 239000001828 Gelatine Substances 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 229910001431 copper ion Inorganic materials 0.000 description 2
- MLIREBYILWEBDM-UHFFFAOYSA-N cyanoacetic acid Chemical compound OC(=O)CC#N MLIREBYILWEBDM-UHFFFAOYSA-N 0.000 description 2
- YAGKRVSRTSUGEY-UHFFFAOYSA-N ferricyanide Chemical compound [Fe+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] YAGKRVSRTSUGEY-UHFFFAOYSA-N 0.000 description 2
- 229920000159 gelatin Polymers 0.000 description 2
- 235000019322 gelatine Nutrition 0.000 description 2
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- IOLCXVTUBQKXJR-UHFFFAOYSA-M potassium bromide Chemical compound [K+].[Br-] IOLCXVTUBQKXJR-UHFFFAOYSA-M 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- BMYNFMYTOJXKLE-UHFFFAOYSA-N 3-azaniumyl-2-hydroxypropanoate Chemical compound NCC(O)C(O)=O BMYNFMYTOJXKLE-UHFFFAOYSA-N 0.000 description 1
- 239000005749 Copper compound Substances 0.000 description 1
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 description 1
- 101100117236 Drosophila melanogaster speck gene Proteins 0.000 description 1
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- KDYFGRWQOYBRFD-UHFFFAOYSA-N Succinic acid Natural products OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 1
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 description 1
- 229910052946 acanthite Inorganic materials 0.000 description 1
- 125000000218 acetic acid group Chemical group C(C)(=O)* 0.000 description 1
- 239000000980 acid dye Substances 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 150000004283 biguanides Chemical class 0.000 description 1
- 239000004305 biphenyl Substances 0.000 description 1
- 235000010290 biphenyl Nutrition 0.000 description 1
- 125000006267 biphenyl group Chemical group 0.000 description 1
- KDYFGRWQOYBRFD-NUQCWPJISA-N butanedioic acid Chemical compound O[14C](=O)CC[14C](O)=O KDYFGRWQOYBRFD-NUQCWPJISA-N 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 150000001880 copper compounds Chemical class 0.000 description 1
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- MXCPYJZDGPQDRA-UHFFFAOYSA-N dialuminum;2-acetyloxybenzoic acid;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3].CC(=O)OC1=CC=CC=C1C(O)=O MXCPYJZDGPQDRA-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002191 fatty alcohols Chemical class 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000004310 lactic acid Substances 0.000 description 1
- 235000014655 lactic acid Nutrition 0.000 description 1
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 1
- 239000011976 maleic acid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 150000007530 organic bases Chemical class 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- ZUOUZKKEUPVFJK-UHFFFAOYSA-N phenylbenzene Natural products C1=CC=CC=C1C1=CC=CC=C1 ZUOUZKKEUPVFJK-UHFFFAOYSA-N 0.000 description 1
- 229920000151 polyglycol Polymers 0.000 description 1
- 239000010695 polyglycol Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003378 silver Chemical class 0.000 description 1
- XUARKZBEFFVFRG-UHFFFAOYSA-N silver sulfide Chemical compound [S-2].[Ag+].[Ag+] XUARKZBEFFVFRG-UHFFFAOYSA-N 0.000 description 1
- 229940056910 silver sulfide Drugs 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- 239000011975 tartaric acid Substances 0.000 description 1
- 235000002906 tartaric acid Nutrition 0.000 description 1
- 150000003585 thioureas Chemical class 0.000 description 1
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
- G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
- G03C5/40—Chemically transforming developed images
- G03C5/44—Bleaching; Bleach-fixing
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
- G03C7/28—Silver dye bleach processes; Materials therefor; Preparing or processing such materials
Definitions
- the material to be processed generally comprises a support on which are coated a plurality of light sensitive silver halide emulsions, which may be in the form of layers or granules and which contain bleachable dyestuffs in a difiusion-resistant form. After exposure, development and fixation, the dyestufis are bleached in dependence on the amount of silver locally present in the silver image. This is generally carried out in a bath which contains an acid, a substance capable of forming silver complexes, such as thiourea, and a bleaching catalyst.
- the metallic silver is not completely oxidized, or impurities accompanying the silver are not completely removed, so that, after treatment in a fixing bath following upon the silver bleaching bath, there is left a residual density which becomes apparent in images to be viewed by reflected light as poor remission in the light areas of the image. While it is possible to improve the result by repeated alternate treatments with the silver bleaching bath and the fixing bath, this method is very troublesome, so that there is a need for a silver bleaching bath which completely oxidizes the metallic silver in a single, short treatment.
- the present invention is based on the observation that a silver bleaching bath which contains a hydrohalic acid, a cupric salt and water-soluble aliphatic carboxylic acid converts metallic silver in a very short time and quantitatively into silver halide, even when the said silver bleaching bath is used after a dye bleaching bath that causes the silver to become less reactive. Accordingly, the invention provides for rehalogenating metallic silver in a photographic material, a bath which contains a cupric salt, a hydrohalic acid and a water-soluble aliphatic carboxylic acid.
- hydrohalic acid there is preferably used hydrochloric or hydrobromic acid. While it is possible to form these acids by double decomposition, for example, by incorporating in the bath potassium bromide and sulfuric acid, the best results have been obtained with baths which contain no or a very small amount of metal ions, for example, alkali metal ions, other than the copper ions, and which are practically free from sulfate ions. Therefore baths which contain, instead of the often used copper sulfate, other copper salts, for example, copper acetate or copper nitrate, are preferred. The baths advantageously contain about 0.5 to 2.0 mols of the hydrohalic acid and about 0.1 to 1.0 mol of the copper salt per liter.
- aliphatic carboxylic acids there may be mentioned, for example, unsaturated acids and polycarboxylic acids, though other acids may likewise be used, provided that they contain no basic substituents and are water-soluble.
- the acids are advantageously composed exclusively of carbon, hydrogen and oxygen, and advantageously contain not more than 7 carbon atoms. It is of advantage to use acids capable of forming watersoluble copper compounds.
- acetic acid As examples of such acids there may be mentioned: acetic acid, lactic acid, cyanoacetic acid, acrylic acid, succinic acid, tartaric acid, citric acid, and maleic acid.
- these acids act, on one hand, as solvents or solution promoters for the products that passivate the metallic silver, such as dyestuff fission products and thiourea complexes, and radicals of bleaching catalysts or of filter dyestuffs.
- these acids are capable of forming complexes with the copper ions, they are able to modify the oxidation conditions.
- the acids give their optimum effect at a concentration ranging from about 1 to 15%, and preferably 2 to 12%.
- the preferred silver bleaching baths of the invention are those which contain, per liter, about 0.5 to 2 mols of a hydrohalic acid, such as hydrochloric acid, 0.5 mol of a copper salt, such as copper nitrate, and about 2 to 12% of an aliphatic carboxylic acid, such as acrylic or citric acid.
- a hydrohalic acid such as hydrochloric acid
- a copper salt such as copper nitrate
- an aliphatic carboxylic acid such as acrylic or citric acid
- the baths can be further improved by adding thereto a small proportion of a surface-active agent, for example, a polyglycol ether of a higher fatty alcohol, and especially a fiuorinated aliphatic carboxylic acid such as described, for example, in U.S. specification No. 2,904,515.
- a surface-active agent for example, a polyglycol ether of a higher fatty alcohol, and especially a fiuorinated aliphatic carboxylic acid such as described, for example, in U.S. specification No. 2,904,515.
- the baths of the invention for rehalogenating metallic silver are suitable for use in all processes in which strongly acid baths are not harmful. They are therefore suitable for use in those color photographic processes in which dyestuffs are not decomposed by acid, more especially, for the silver dye bleaching process.
- the baths of the invention are superior to the known silver bleaching baths. They bring about more rapidly the complete rehalogenation of metallic silver or complete removal of the impurities associated with the silver in multilayer materials to be viewed by reflected light so that, after subsequent removal of the silver halide in a fixing bath, clearer pictures and above all better whites, are obtained.
- the azo-dyestuifs suitable for use in the silver dye bleaching process have in general a good resistance and satisfactory stability to the rehalogenation baths of the invention, but there are cases in which the dyestufis are adversely affected when the bath has a very high concentration of aliphaticcarboxylic acid.
- the addition of an organic base or of a salt thereof to the rehalogenation bath protects the dyestuif from oxidation without impairing the action of the bath on the silver to be rehalogenated or on the dark impurities accompanying the silver.
- Especially suitable bases are biguanides such, for example, as diphenyl-4:4'-dibiguanide, in a concentration below 1%. While baths containing no base give in many cases, though not always, satisfactory results, baths that contain a base as aforesaid are more generally applicable.
- Example 1 A white-reflecting support was coated with a layer of a red-sensitized silver bromide emulsion containing a diffusion-resistant blue-green azo-dyestuff, this layer was coated with a green-sensitized silver bromide gelatine emulsion containing a diffusion-resistant purple aZo-dyestuff, the latter layer was coated with a yellow filter layer, and the filter layer was coated with the topmost layer of a non-sensitized silver bromide gelatine emulsion containing a diffusion-resistant yellow azo-dyestuif.
- the material was exposed, developed, fixed and then bleached in a bath containing hydrochloric acid, sodium chloride, thiourea and 2:3-aminohydroxyphenazine, whereby all dyestuff in the areas that had been exposed to white light were destroyed.
- the material was thoroughly washed and bleached for 10 minutes at 24 C. in one of the silver bleaching baths described below, once more washed, fixed, washed and dried. The densities of the exposed areas as viewed by -reflected light were then measured.
- the log l /I value was found to be 0.32.
- the known ferricyanide baths did not produce any more favorable results; above, all, they produced spotty images which made accurate measurements impossible.
- baths C to M of the invention which had the same composition as bath (B) exc pt that the acetic acid was replaced by the additives specified.
- concentrations specified are those that gave the optimum results in another series of tests:
- Example 2 A material having the arrangement of layers described in Example 1, was made in which the green-sensitized layer contained a dyestuif of the formula SOaH lTIH:
- Hydrochloric acid 37% strength -ml-.. Copper nitrate .3H O grams- Acrylic acid ml 125 Surface-active agent 0.1% ml 15 Diphenyl-4:4'-dibiguanide hydrochloride --grams-- 3 Water to make 1 liter.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and a watersoluble aliphatic carboxylic acid composed exclusively of carbon, hydrogen and oxygen.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions which comprises a cupric salt, a hydrohalic acid, a surface-active agent and a water-soluble aliphatic carboxylic acid composed exclusively of carbon, hydrogen and oxygen.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid, a biguanide base and a water-soluble aliphatic carboxylic acid composed exclusively of carbon, hydrogen and oxygen.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and acetic acid.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and acrylic acid.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and citric acid.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cu ric salt, a hydrohalic acid, a surface-active agent and acrylic acid.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid, a surface-active agent and citric acid.
- a bath suitable for rehalogenating metallic silver in a photographic material which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid, a surfaceactive agent, diphenyl-4:4'-dibiguanide hydrochloride and acrylic acid.
- the step which comprises carrying out the silver bleaching after the dye bleaching in a bath which comprises a cupric salt, a hydrohalic acid and a water-soluble aliphatic carboxylic acid.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Silver Salt Photography Or Processing Solution Therefor (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
United States Patent 3 264,107 BATHS SUITABLE FdR REHALOGENATHNG ME- TALLIC SILVER IN PHOTOGRAPHIC MATE- RIALS Ren von Warthurg, Basel, Switzerland, assignor to Ciha Limited, Basel, Switzerland, a Swiss company No Drawing. Filed Aug. 29, 1952, Ser. No. 220,156 Claims priority, application Switzerland, Sept. 8, 1961, 10,465/61 Claims. (Cl. 96-450) In many photographic, and more especially color photographic processes there arises the necessity of removing a metallic silver image or oxidizing it to a metal salt image, for example, without attacking a color image.
While it is generally easy to remove metallic silver completely from single-layer materials that are free from color couplers or dyestuiis, this is often difiicult in the case of multi-layer or mixed grain emulsion materials containing dyestuffs, because there remains in the area from which silver has been removed a faint, dark colored residual image, which may consist of silver sulfide or of silver enclosed by dyestuif, and which is particularly troublesome in the case of images to be viewed by reflected light.
To oxidize completely silver images in mate-rials that have been subjected to color development numerous proposals have been made for activating the usual ferricyanide baths or replacing them by baths of a different nature.
The problem of the complete removal of metallic silver arises also in the silver dye bleaching process in which, as is known, dyestuffs are bleached out in single-layer or multi-layer materials in dependence on the amount of metallic silver locally present in the photographic image, and any remaining metallic silver must be subsequently removed.
The material to be processed generally comprises a support on which are coated a plurality of light sensitive silver halide emulsions, which may be in the form of layers or granules and which contain bleachable dyestuffs in a difiusion-resistant form. After exposure, development and fixation, the dyestufis are bleached in dependence on the amount of silver locally present in the silver image. This is generally carried out in a bath which contains an acid, a substance capable of forming silver complexes, such as thiourea, and a bleaching catalyst.
When the material is subsequently treated in a known silver bleaching bath, for example, a bath containing copper sulfate, sodium chloride and hydrochloric acid,
the metallic silver is not completely oxidized, or impurities accompanying the silver are not completely removed, so that, after treatment in a fixing bath following upon the silver bleaching bath, there is left a residual density which becomes apparent in images to be viewed by reflected light as poor remission in the light areas of the image. While it is possible to improve the result by repeated alternate treatments with the silver bleaching bath and the fixing bath, this method is very troublesome, so that there is a need for a silver bleaching bath which completely oxidizes the metallic silver in a single, short treatment.
The present invention is based on the observation that a silver bleaching bath which contains a hydrohalic acid, a cupric salt and water-soluble aliphatic carboxylic acid converts metallic silver in a very short time and quantitatively into silver halide, even when the said silver bleaching bath is used after a dye bleaching bath that causes the silver to become less reactive. Accordingly, the invention provides for rehalogenating metallic silver in a photographic material, a bath which contains a cupric salt, a hydrohalic acid and a water-soluble aliphatic carboxylic acid.
As the hydrohalic acid there is preferably used hydrochloric or hydrobromic acid. While it is possible to form these acids by double decomposition, for example, by incorporating in the bath potassium bromide and sulfuric acid, the best results have been obtained with baths which contain no or a very small amount of metal ions, for example, alkali metal ions, other than the copper ions, and which are practically free from sulfate ions. Therefore baths which contain, instead of the often used copper sulfate, other copper salts, for example, copper acetate or copper nitrate, are preferred. The baths advantageously contain about 0.5 to 2.0 mols of the hydrohalic acid and about 0.1 to 1.0 mol of the copper salt per liter.
As aliphatic carboxylic acids there may be mentioned, for example, unsaturated acids and polycarboxylic acids, though other acids may likewise be used, provided that they contain no basic substituents and are water-soluble. The acids are advantageously composed exclusively of carbon, hydrogen and oxygen, and advantageously contain not more than 7 carbon atoms. It is of advantage to use acids capable of forming watersoluble copper compounds.
As examples of such acids there may be mentioned: acetic acid, lactic acid, cyanoacetic acid, acrylic acid, succinic acid, tartaric acid, citric acid, and maleic acid.
As a rule, the best results are achieved with acrylic and citric acid.
The mechanism behind the action of these acids has not yet been completely elucidated. It is probable that they act, on one hand, as solvents or solution promoters for the products that passivate the metallic silver, such as dyestuff fission products and thiourea complexes, and radicals of bleaching catalysts or of filter dyestuffs. However, since, on the other hand, these acids are capable of forming complexes with the copper ions, they are able to modify the oxidation conditions. The acids give their optimum effect at a concentration ranging from about 1 to 15%, and preferably 2 to 12%.
Accordingly, the preferred silver bleaching baths of the invention are those which contain, per liter, about 0.5 to 2 mols of a hydrohalic acid, such as hydrochloric acid, 0.5 mol of a copper salt, such as copper nitrate, and about 2 to 12% of an aliphatic carboxylic acid, such as acrylic or citric acid.
The baths can be further improved by adding thereto a small proportion of a surface-active agent, for example, a polyglycol ether of a higher fatty alcohol, and especially a fiuorinated aliphatic carboxylic acid such as described, for example, in U.S. specification No. 2,904,515.
The baths of the invention for rehalogenating metallic silver are suitable for use in all processes in which strongly acid baths are not harmful. They are therefore suitable for use in those color photographic processes in which dyestuffs are not decomposed by acid, more especially, for the silver dye bleaching process. In the known method of carrying out the silver dye bleaching process, in which the silver bleaching bath is applied after an acid dye bleaching bath, the baths of the invention are superior to the known silver bleaching baths. They bring about more rapidly the complete rehalogenation of metallic silver or complete removal of the impurities associated with the silver in multilayer materials to be viewed by reflected light so that, after subsequent removal of the silver halide in a fixing bath, clearer pictures and above all better whites, are obtained.
The azo-dyestuifs suitable for use in the silver dye bleaching process have in general a good resistance and satisfactory stability to the rehalogenation baths of the invention, but there are cases in which the dyestufis are adversely affected when the bath has a very high concentration of aliphaticcarboxylic acid. In such cases the addition of an organic base or of a salt thereof to the rehalogenation bath protects the dyestuif from oxidation without impairing the action of the bath on the silver to be rehalogenated or on the dark impurities accompanying the silver. Especially suitable bases are biguanides such, for example, as diphenyl-4:4'-dibiguanide, in a concentration below 1%. While baths containing no base give in many cases, though not always, satisfactory results, baths that contain a base as aforesaid are more generally applicable.
The following examples illustrate the invention:
Example 1 A white-reflecting support was coated with a layer of a red-sensitized silver bromide emulsion containing a diffusion-resistant blue-green azo-dyestuff, this layer was coated with a green-sensitized silver bromide gelatine emulsion containing a diffusion-resistant purple aZo-dyestuff, the latter layer was coated with a yellow filter layer, and the filter layer was coated with the topmost layer of a non-sensitized silver bromide gelatine emulsion containing a diffusion-resistant yellow azo-dyestuif.
The material was exposed, developed, fixed and then bleached in a bath containing hydrochloric acid, sodium chloride, thiourea and 2:3-aminohydroxyphenazine, whereby all dyestuff in the areas that had been exposed to white light were destroyed. The material was thoroughly washed and bleached for 10 minutes at 24 C. in one of the silver bleaching baths described below, once more washed, fixed, washed and dried. The densities of the exposed areas as viewed by -reflected light were then measured.
As a measure of the action of the silver bleaching bath there are given below the values for log I /I for blue light, in which I is the intensity of the incident light and I is the intensity of the remitted light. The corresponding values for green and red light are smaller, but they vary relatively to each other in a similar ratio.
(A) For a known bath of the composition:
Sodium chloride gr-ams 100 Crystal copper sulfate grams 100 Hydrochloric acid 37% strength --ml 100 Water to make 1 liter.
the log l /I value was found to be 0.32. The known ferricyanide baths did not produce any more favorable results; above, all, they produced spotty images which made accurate measurements impossible.
(B) For a bath in accordance with the invention having the composition:
Hydrochloric acid 37% --ml 90 Copper nitrate, Cu(NO .3H O grams-.. 135 Acetic acid -grams 60 Water to make 1 liter.
the log I /I value was found to be 0.24.
In the following Table are given baths C to M of the invention, which had the same composition as bath (B) exc pt that the acetic acid was replaced by the additives specified. The concentrations specified are those that gave the optimum results in another series of tests:
Example 2 A material having the arrangement of layers described in Example 1, was made in which the green-sensitized layer contained a dyestuif of the formula SOaH lTIH:
Hydrochloric acid 37% strength -ml-.. Copper nitrate .3H O grams- Acrylic acid ml 125 Surface-active agent 0.1% ml 15 Diphenyl-4:4'-dibiguanide hydrochloride --grams-- 3 Water to make 1 liter.
In the area exposed only to blue and red light the magenta dyestuff had retained its original color strength, while the color strength of the other area exposed to the same light, after treatment in a control bath of identical composition but not containing diphenyl dibiguanide, was considerably weakened. For the areas exposed to white light, both after treatment with the bath containing biguanide and with the control bath, the value for log l /I was 0.16.
What is claimed is:
ll. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and a watersoluble aliphatic carboxylic acid composed exclusively of carbon, hydrogen and oxygen.' 7
2. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions which comprises a cupric salt, a hydrohalic acid, a surface-active agent and a water-soluble aliphatic carboxylic acid composed exclusively of carbon, hydrogen and oxygen.
3. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid, a biguanide base and a water-soluble aliphatic carboxylic acid composed exclusively of carbon, hydrogen and oxygen.
4. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and acetic acid. I
5. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and acrylic acid.
6. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid and citric acid.
7. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cu ric salt, a hydrohalic acid, a surface-active agent and acrylic acid.
8. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid, a surface-active agent and citric acid.
9. A bath suitable for rehalogenating metallic silver in a photographic material, which bath is substantially free from alkali metal ions and sulfate ions and which comprises a cupric salt, a hydrohalic acid, a surfaceactive agent, diphenyl-4:4'-dibiguanide hydrochloride and acrylic acid.
10. In a process for the production of a photographic image by the silver dye bleaching process, the step which comprises carrying out the silver bleaching after the dye bleaching in a bath which comprises a cupric salt, a hydrohalic acid and a water-soluble aliphatic carboxylic acid.
References Cited by the Examiner UNITED STATES PATENTS 10/ 1938 Rogers 204-52 X 8/ 1943 Morris 96-20 6/ 1944 Ehrenfried 96-20 1/1950 Speck 96-60 2/ 1954 Mueller 96-20 9/ 1958 Hanover 204-52 9/1958 Lyman et a1. 96-60 1/ 1964 Tregillus et a1 96-29 FOREIGN PATENTS 5/1957 Great Britain. 6/ 1957 Great Britain.
NORMAN G. TORCHIN, Primary Examiner.
A. D. RICCI, C. E. DAVIS, Assistant Examiners.
Claims (1)
1. A BATH SUITABLE FOR REHALOGENATING METALLIC SILVER IN A PHOTOGRAPHIC MATERIAL, WHICH BATH IS SUBSTANTIALLY FREE FROM ALKALI METAL IONS AND SULFATE IONS AND WHICH COMPRISES A CURPRIC SALT, A HYDROHALIC ACID AND A WATER SOLUBLE ALIPHATIC CARBOXYLIC ACID COMPOSED EXCLUSIVELY OF CARBON, HYDROGEN AND OXYGEN.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH1046561A CH405071A (en) | 1961-09-08 | 1961-09-08 | Bath for the re-halogenation of metallic silver |
Publications (1)
Publication Number | Publication Date |
---|---|
US3264107A true US3264107A (en) | 1966-08-02 |
Family
ID=4363520
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US220156A Expired - Lifetime US3264107A (en) | 1961-09-08 | 1962-08-29 | Baths suitable for rehalogenating metallic silver in photographic materials |
Country Status (7)
Country | Link |
---|---|
US (1) | US3264107A (en) |
BE (1) | BE622239A (en) |
CH (1) | CH405071A (en) |
DE (1) | DE1154348B (en) |
ES (1) | ES280611A1 (en) |
GB (1) | GB949440A (en) |
NL (1) | NL282992A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5445925A (en) * | 1993-04-13 | 1995-08-29 | Eastman Kodak Company | Method of forming a photographic color image |
US5569443A (en) * | 1994-11-18 | 1996-10-29 | The Dow Chemical Company | Method for removing hydrogen sulfide from a gas using polyamino disuccinic acid |
US5585226A (en) * | 1995-08-30 | 1996-12-17 | Eastman Kodak Company | Polyamino monoesuccinates for use in photographic processes |
US5652085A (en) * | 1995-08-30 | 1997-07-29 | Eastman Kodak Company | Succinic acid derivative degradable chelants, uses and composition thereof |
US5716767A (en) * | 1995-12-29 | 1998-02-10 | Agfa-Gevaert Ag | Bleaching bath for photographic black-&-white material |
US5741555A (en) * | 1995-05-22 | 1998-04-21 | The Dow Chemical Company | Succinic acid derivative degradable chelants, uses and compositions thereof |
US5795681A (en) * | 1994-07-09 | 1998-08-18 | Mueller; Helmut | Stabilization of holograms formed in gelatin |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2133255A (en) * | 1937-05-19 | 1938-10-11 | Percy A E Armstrong | Process of electroplating copper |
US2326055A (en) * | 1940-10-10 | 1943-08-03 | Eastman Kodak Co | Dye bleaching process |
US2350736A (en) * | 1942-07-10 | 1944-06-06 | Eastman Kodak Co | Method of producing dye images |
US2494068A (en) * | 1946-06-03 | 1950-01-10 | Eastman Kodak Co | Photographic relief image |
US2669519A (en) * | 1952-04-26 | 1954-02-16 | Seaplant Chemical Corp | Gelling compositions |
GB774194A (en) * | 1954-06-19 | 1957-05-08 | Photo Chemical Company Ltd | Improvements in photographic bleach-fix baths |
GB777635A (en) * | 1954-03-11 | 1957-06-26 | Gevaert Photo Prod Nv | Improvements in or relating to a process for simultaneously bleaching and fixing a photographic colour image |
US2853443A (en) * | 1956-04-25 | 1958-09-23 | Westinghouse Electric Corp | Addition agent for acid copper electrolytes |
US2854386A (en) * | 1955-02-07 | 1958-09-30 | Aladdin Ind Inc | Method of photographically printing conductive metallic patterns |
US3017270A (en) * | 1958-03-31 | 1962-01-16 | Eastman Kodak Co | Photographic silver halide diffusion transfer process |
-
0
- NL NL282992D patent/NL282992A/xx unknown
- BE BE622239D patent/BE622239A/xx unknown
-
1961
- 1961-09-08 CH CH1046561A patent/CH405071A/en unknown
-
1962
- 1962-08-23 GB GB32462/62A patent/GB949440A/en not_active Expired
- 1962-08-29 US US220156A patent/US3264107A/en not_active Expired - Lifetime
- 1962-09-07 ES ES0280611A patent/ES280611A1/en not_active Expired
- 1962-09-07 DE DEC27892A patent/DE1154348B/en active Pending
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2133255A (en) * | 1937-05-19 | 1938-10-11 | Percy A E Armstrong | Process of electroplating copper |
US2326055A (en) * | 1940-10-10 | 1943-08-03 | Eastman Kodak Co | Dye bleaching process |
US2350736A (en) * | 1942-07-10 | 1944-06-06 | Eastman Kodak Co | Method of producing dye images |
US2494068A (en) * | 1946-06-03 | 1950-01-10 | Eastman Kodak Co | Photographic relief image |
US2669519A (en) * | 1952-04-26 | 1954-02-16 | Seaplant Chemical Corp | Gelling compositions |
GB777635A (en) * | 1954-03-11 | 1957-06-26 | Gevaert Photo Prod Nv | Improvements in or relating to a process for simultaneously bleaching and fixing a photographic colour image |
GB774194A (en) * | 1954-06-19 | 1957-05-08 | Photo Chemical Company Ltd | Improvements in photographic bleach-fix baths |
US2854386A (en) * | 1955-02-07 | 1958-09-30 | Aladdin Ind Inc | Method of photographically printing conductive metallic patterns |
US2853443A (en) * | 1956-04-25 | 1958-09-23 | Westinghouse Electric Corp | Addition agent for acid copper electrolytes |
US3017270A (en) * | 1958-03-31 | 1962-01-16 | Eastman Kodak Co | Photographic silver halide diffusion transfer process |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5445925A (en) * | 1993-04-13 | 1995-08-29 | Eastman Kodak Company | Method of forming a photographic color image |
US5859273A (en) * | 1993-05-20 | 1999-01-12 | The Dow Chemical Company | Succinic acid derivative degradable chelants, uses and compositions thereof |
US5795681A (en) * | 1994-07-09 | 1998-08-18 | Mueller; Helmut | Stabilization of holograms formed in gelatin |
US5569443A (en) * | 1994-11-18 | 1996-10-29 | The Dow Chemical Company | Method for removing hydrogen sulfide from a gas using polyamino disuccinic acid |
US5741555A (en) * | 1995-05-22 | 1998-04-21 | The Dow Chemical Company | Succinic acid derivative degradable chelants, uses and compositions thereof |
US5585226A (en) * | 1995-08-30 | 1996-12-17 | Eastman Kodak Company | Polyamino monoesuccinates for use in photographic processes |
US5652085A (en) * | 1995-08-30 | 1997-07-29 | Eastman Kodak Company | Succinic acid derivative degradable chelants, uses and composition thereof |
US5716767A (en) * | 1995-12-29 | 1998-02-10 | Agfa-Gevaert Ag | Bleaching bath for photographic black-&-white material |
Also Published As
Publication number | Publication date |
---|---|
GB949440A (en) | 1964-02-12 |
DE1154348B (en) | 1963-09-12 |
BE622239A (en) | |
CH405071A (en) | 1965-12-31 |
ES280611A1 (en) | 1963-03-01 |
NL282992A (en) |
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