EP0034793B1 - Method of processing photographic silver dye bleaching materials, compositions suitable for it and their preparation from concentrates or partial concentrates, the concentrates and partial concentrates - Google Patents

Description

The present invention relates to a new process for processing exposed and developed silver color bleaching materials and to preparations suitable for this process in the form of ready-to-use aqueous solutions or of water-dilutable concentrates in liquid or solid form.

• (A) Entwicklung des latenten Silberbildes,
• (B) Farbbleichung an den metallisches Silber enthaltenden Bildstellen
• (C) Silberbleichung: Umwandlung des Rest-Silberbildes in komplexe, lösliche Silberverbindungen
• (D) Fixierung: Herauslösen und Entfernen aller in Form von komplexen löslichen Silberverbindungen

Four processing stages are generally required for processing silver color bleaching materials:

• (A) development of the latent silver image,
• (B) Color bleaching at the image areas containing metallic silver
• (C) Silver bleaching: conversion of the residual silver image into complex, soluble silver compounds
• (D) Fixation: removing and removing all in the form of complex soluble silver compounds

Several processes have become known which make it possible to shorten this process sequence: In German Offenlegungsschrift 2,448,433, for example, a process is described in which steps (B) color bleaching and (C) silver bleaching are combined to form a single step. US Pat. No. 3,868,253 describes a processing sequence in which steps (C) silver bleaching and (D) fixation are carried out simultaneously in a single bleach-fix bath. Finally, a processing method for silver color bleaching materials has become known from German patent specification 735 672, in which process steps (B), (C) and (D) are carried out simultaneously in a single bath.

The preparations (baths) used for the color and / or silver bleaching or the combined bleach-fixation are strongly acidic, i.e. H. have a pH of less than 2, especially less than 1. This pH is generally set using strong acids, primarily mineral acids, such as hydrochloric acid, sulfuric acid, nitric or phosphoric acid, and also sulfamic acid. Good results are also obtained with certain strong organic acids, such as p-toluenesulfonic acid. The mineral acids most commonly used for bleaching baths so far have some important disadvantages that can have an adverse effect on general use. So z. B. hydrochloric acid highly volatile and therefore has a particularly corrosive effect on z. B. apparatus and devices in which the processing of the photographic material is carried out. Most mineral acids, with the exception of sulfamic acid, are also liquid. Their use, especially in the amateur sector, can therefore pose certain dangers, e.g. B. by spilling or breaking vessels.

For this reason, the use of solid instead of liquid acids is particularly advantageous. It facilitates the packaging, the transport and the storage of preparations for color and / or silver bleaching. The sulfamic acid, which is suitable per se and can easily be prepared in free-flowing powder form, can in many cases be used as a substitute for liquid mineral acids. One disadvantage, however, is their relatively poor solubility in water. It has also been shown that it reacts with tertiary phosphines, which are used as bleach accelerators, and leads to unstable bleach baths. p-Toluenesulfonic acid, which can also be used in free-flowing powder form, has a high water solubility and provides stable bleaching baths. Disadvantages are the significantly higher price compared to mineral acids, and the high molecular weight, which requires the use of large amounts of weight. The high carbon ballast of p-toluenesulfonic acid also has an adverse ecological impact due to the high oxygen demand in the waste water.

The object of the present invention is to provide strong mineral acids, as are required in the processing of photographic silver color bleaching materials, in a suitable form in order to overcome the disadvantages mentioned above.

It has now been found that in bleaching baths for the silver color bleaching process, instead of mineral acids, their adducts with certain acid amides and lactams can be used. A number of these adducts are solid, of good stability and of high water solubility. They dissociate easily in their original constituents in aqueous solution, so that in many cases such solutions can be used instead of the corresponding mineral acids.

• (a) eine Säurekomponente,
• (b) ein Silberkomplexierungsmittel,
• (c) einen oder mehrere Bleichkatalysatoren,
• (d) gegebenenfalls ein Oxydationsschutzmittel,
• (e) gegebenenfalls ein wasserlösliches Oxydationsmittel und
• (f) gegebenenfalls einen Bleichbeschleuniger

enthalten, dadurch gekennzeichnet, daß die Komponente (a) ein wasserlösliches Addukt aus oinem Säureamid einer aliphatischen Säure mit 1 bis 4 Kohlenstoffatomen oder einer monocyclischen aromatischen Säure oder aus einem Diamid der Kohlensäure oder Thiokohlensäure oder aus einem Lactam von ^p δ- oder ε-Aminosäuren und einer starken Mineralsäure ist.The present invention relates to a process for processing exposed and developed photographic silver color bleaching materials by treating the exposed and developed material with aqueous bleaching preparations which

• (a) an acid component,
• (b) a silver complexing agent,
• (c) one or more bleaching catalysts,
• (d) optionally an antioxidant,
• (e) optionally a water soluble oxidizing agent and
• (f) optionally a bleach accelerator

Contain, characterized in that component (a) is a water-soluble adduct of an acid amide of an aliphatic acid with 1 to 4 carbon atoms or a monocyclic aromatic acid or of a diamide of carbonic acid or thiocarbonic acid or from a lactam of ^p δ- or ε-amino acids and is a strong mineral acid.

The invention further relates to the preparations for carrying out the process, furthermore the concentrates and partial concentrates for the production of the ready-to-use aqueous preparations, and also a process for the production of the aqueous preparations.

The acid amides used to prepare the adducts with the strong mineral acids are those of low molecular weight aliphatic acids, ie with 1 to 4, in particular 1 or 2, carbon atoms, and also of monocyclic aromatic acids, such as, in particular, optionally with alkyl (C ₁ -C ₄ ) , Halogen, nitro or cyano substituted benzoic acids as well as the diamides (ureas) of carbonic and thiocarbonic acids. The nitrogen atoms of the amides can be mono- or in particular disubstituted with alkyl having 1 to 4 carbon atoms, in particular with methyl. Examples of suitable amides are thiourea, benzamide and preferably urea, formamide, dimethylformamide, acetamide and dimethylacetamide.

Suitable lactams (cyclic amides) are those of y-, α- and e-amino acids (4 to 6 carbon atoms), which may be substituted on the nitrogen atom with lower alkyl (C ₁ -C _Q ), in particular with methyl. Examples of the lactams mentioned are piperidone (ö-valerolactam), and in particular 2-pyrrolidone (y-butyrolactam), N-methyl-2-pyrrolidone and caprolactam.

Possible strong mineral acids are phosphoric acid and perchloric acid, and in particular sulfuric acid, hydrochloric acid or other hydrohalic acids (HBr, HJ) and nitric acid.

An overview of the properties of acid amide-mineral acid adducts can be found e.g. B. with J. Zabicky (ed.) "The Chemistry of Amides" from the series "The Chemistry of Functional Groups", Interscience, London 1970.

Table 1 below shows the composition of the properties of various mineral acid adducts of amides and lactams. The generally colorless and stable addition compounds are partly liquid and partly occur in crystallized form. As far as possible, the melting points of crystalline products are given. The connections are partly hygroscopic.

The mineral acid adducts of urea are particularly well known, in particular the adducts of one mole of urea with 0.5 or 1 mole of sulfuric acid. Information about the properties of these adducts, about their stability, the reaction kinetics in the melt and in aqueous solutions can be found u. a. with L. H. Dalman, J. Am. Chem. Soc. 56, 549 (1934), P. Baumgarten, Chem. Ber. 69, 1929 (1936), E. Cherbuliez & F. Landolt, Helv. 29, 1438 (1946) and G. M. Schwab & E. Schwab-Agallidis, Angew. Chemie, 65, 418 (1953).

The mineral acid adducts of urea are produced either directly from the components or their solutions or also by the action of mineral acids on cyanamide, the latter decomposing to urea, which then forms the addition compound with the acid. There are references to the production of urea-mineral acid adducts. a. in German patent specification 239 309, American patent specification 3 330 864 or in English patent specifications 196 601 and 1 109 619.

The adducts used according to the invention are stable in solid form and can easily be prepared in the form of free-flowing water-soluble powders or granules. The adducts of urea with sulfuric or nitric acid are preferred, furthermore thiourea with sulfuric acid and acetamide with hydrochloric acid.

• Nach diesem Verfahren wird Harnstoff in 1 00prozentige Schwefelsäure (Monohydrat) unter Kühlung direkt in fester Form eingetragen, wobei man die Temperatur während der Reaktion nicht über etwa 100°C (vorzugsweise 70°C bis 100°C) steigen läßt. Man erhält auf diese Weise direkt eine Schmelze von Harnstoff-Hydrogensulfat oder Harnstoff-Sulfat, je nachdem ob ein oder zwei Mol Harnstoff pro Mol Schwefelsäure eingetragen wurden. Die Verbindungen werden durch Kühlung in die feste Form übergeführt und gegebenenfalls zerkleinert.

The adducts of urea with sulfuric acid which are particularly suitable as acid components for the preparations according to the present invention exist in two stable forms: urea sulfate, the adduct of two moles of urea with one mole of sulfuric acid, and urea hydrogen sulfate, the adduct of one mole of urea with one mole of sulfuric acid. Both forms can be produced directly in an anhydrous solid form using a simple manufacturing process:

• According to this process, urea is introduced in 100% sulfuric acid (monohydrate) with cooling directly in solid form, the temperature not being allowed to rise above about 100 ° C. (preferably 70 ° C. to 100 ° C.) during the reaction. In this way, a melt of urea hydrogen sulfate or urea sulfate is obtained directly, depending on whether one or two moles of urea have been introduced per mole of sulfuric acid. The compounds are converted into the solid form by cooling and optionally comminuted.

In the production of the urea-sulfuric acid adducts mentioned, it is essential that exactly 100% sulfuric acid is used; If the melt contains free water or sulfur trioxide, the stability of the melt is significantly reduced. The melt can by suitable methods, such as. B. be used in the production of alkali metal hydroxides (see. Ullmanns Encyklopadie der industrial chemistry, 4th edition, Verlag Chemie, Weinheim, Vol. 17 (1979), pp. 204 f), converted into a solid form suitable for the application . In particular, it can be crystallized in the form of freely flowing pearls, pills, flakes or flakes that are immediately soluble in water. The sulfuric acid adducts can be brought into the form of pearls if they are z. B. sprayed in a cooling tower.

The sulfuric acid adducts of urea can also be prepared in an aqueous medium. Thereafter, urea is introduced into an aqueous sulfuric acid solution at about 50 ° C. with stirring. This gives a suspension of the crystallizing urea sulfate, which is filtered off and optionally dried (cf. Ullmanns Encyklopadie der Technische Chemie, 4th edition, Verlag Chemie, Weinheim, 2, 154, 672, 698 (1972)).

By forming adducts with amides, solid, hygroscopic acids can also be brought into a less hygroscopic form. For example, trichloroacetic acid and p-toluenesulfonic acid completely melt when exposed to an atmosphere with 76% relative humidity. The adducts of these acids with z. B. urea, pyrrolidone or thiourea remain under the conditions mentioned in crystalline form.

The most important constituents of the baths used for color bleaching are a strong acid in the form of the acid adduct (a), a complexing agent for the silver (b) and a color bleaching catalyst (c). Diazine compounds such as pyrazine, quinoxaline or phenazine and their derivatives are primarily used as color bleaching catalysts.

Suitable bleaching catalysts are e.g. B. from German patents and patent publications Nos. 735 672, 1 547 720, 2 144 297, 2 144 298, 2 722 776 or 2 722 777 known.

A suitable silver complexing agent can e.g. B. be thiourea. Favorable results are obtained if a water-soluble iodide (alkali metal iodide, preferably sodium or potassium iodide, furthermore ammonium iodide) is used as the complexing agent, as described for. B. is described in U.S. Patent 3,620,744. This can prevent the accumulation of disruptive silver complexes in the bleaching bath. However, an antioxidant must be used to prevent the iodide from oxidizing to iodine.

Reductones or water-soluble mercapto compounds are advantageously used as antioxidants (d).

oder vorzugsweise

in Betracht, worin q eine ganze Zahl im Wert von 2 bis 12, B eine Sulfonsäure- oder Carbonsäuregruppe und m eine der Zahlen 3 und 4 bedeuten. Als Oxydationsschutzmittel verwendbare Mercaptoverbindungen sind in der DE-OS 2 258 076 und der DE-OS 2 423 814 beschrieben. Als weitere Oxydationsschutzmittel geeignet sind Alkalimetall-, Erdalkalimetall- oder Ammoniumbisulfitaddukte von organischen Carbonylverbindungen, vorzugsweise Alkalimetall- oder Ammoniumbisulfitaddukte von Monoaldehyden mit 1 bis 4 oder Dialdehyden mit 2 bis 5 Kohlenstoffatomen (DE-OS 2 737 142).Suitable reductones are in particular aci reductions with a 3-carbonylenediol (1,2) grouping, such as reductin, triose reductone or preferably ascorbic acid. As mercapto compounds come e.g. B. thioglycerin, but especially the compounds of formula

or preferably

into consideration, in which q is an integer from 2 to 12, B is a sulfonic acid or carboxylic acid group and m is one of the numbers 3 and 4. Mercapto compounds which can be used as antioxidants are described in DE-OS 2 258 076 and DE-OS 2 423 814. Suitable further antioxidants are alkali metal, alkaline earth metal or ammonium bisulfite adducts of organic carbonyl compounds, preferably alkali metal or ammonium bisulfite adducts of monoaldehydes with 1 to 4 or dialdehydes with 2 to 5 carbon atoms (DE-OS 2 737 142).

Examples include the particularly preferred formaldehyde bisulfite adduct, and also the corresponding adducts of acetaldehyde, propionaldehyde, butyraldehyde or isobutyraldehyde, of glyoxal, malondialdehyde or glutardialdehyde. If appropriate, the tertiary water-soluble phosphines mentioned below as bleach accelerators can also be used simultaneously as antioxidants.

For baths with which the dye and the image silver are to be bleached at the same time, or also for baths which are only used for silver bleaching, the addition of a water-soluble oxidizing agent (s) is necessary; in addition, the concentration of the color bleaching catalyst must be increased significantly compared to a simple color bleaching bath, as z. B. was described in German Offenlegungsschrift 2,448,433.

Water-soluble aromatic mononitro and dinitro compounds and anthraquinone sulfonic acid derivatives are expediently used as the oxidizing agent (s). The use of such oxidizing agents serves not only to oxidize the silver but also to influence the color balance and the contrast of the images produced by the color bleaching process and is known from German patent specification 735 672, British patent specifications 539 190 and 539 509 and Japanese patent publication 22 673/69.

worin n gleich 1 oder 2 ist und R sowie R' Wasserstoff, Niederalkyl mit 1 bis 4 Kohlenstoffatomen, Hydroxyl, Alkoxy, Amino oder Halogen (Chlor, Brom) bedeuten. Die Sulfonsäuren können als leichtlösliche Salze zugefügt werden. Geeignet sind z. B. die Natrium- oder Kaliumsalze der folgenden Säuren :

• o-Nitrobenzolsulfonsäure,
• m-Nitrobenzolsulfonsäure,
• 2,4-Dinitrobenzolsulfonsäure,
• 3,5-Dinitrobenzolsulfonsäure,
• 3-Nitro-4-chlorbenzolsulfonsäure,
• 2-Chlor-5-nitrobenzolsulfonsäure,
• 4-Methyl-3,5-dinitrobenzolsulfonsäure,
• 3-Chlor-2,5-dinitrobenzolsulfonsäure,
• 2-Amino-4-nitrobenzolsulfonsäure,
• 2-Amino-4-nitro-5-methoxybenzolsulfonsäure,
• 4-Nitrophenol-2-sulfonsäure.

The mononitro and dinitro compounds are preferably mono- or dinitrobenzenesulfonic acids, e.g. B. those of the formula

wherein n is 1 or 2 and R and R 'are hydrogen, lower alkyl having 1 to 4 carbon atoms, hydroxyl, alkoxy, amino or halogen (chlorine, bromine). The sulfonic acids can be added as easily soluble salts. Are suitable for. B. the sodium or potassium salts of the following acids:

• o-nitrobenzenesulfonic acid,
• m-nitrobenzenesulfonic acid,
• 2,4-dinitrobenzenesulfonic acid,
• 3,5-dinitrobenzenesulfonic acid,
• 3-nitro-4-chlorobenzenesulfonic acid,
• 2-chloro-5-nitrobenzenesulfonic acid,
• 4-methyl-3,5-dinitrobenzenesulfonic acid,
• 3-chloro-2,5-dinitrobenzenesulfonic acid,
• 2-amino-4-nitrobenzenesulfonic acid,
• 2-amino-4-nitro-5-methoxybenzenesulfonic acid,
• 4-nitrophenol-2-sulfonic acid.

In addition to their function as silver bleaches, the compounds of component (e) serve to flatten the gradation.

• G_J e Tetraäthylammoniumjodid; (CH₃)₃N(CH₂)₂N(CH₃)₃2J^e;
• (CH₃)₃N(CH₂)₆N(CH₃)₃ · 2J^-, N-Methylpyridiniumjodid;
• N-Methylchinoliniumjodid;
• N-Hydroxyäthylpyridiniumchlorid;
• N-Hydroxypropylpyridiniumbromid;
• N-Methyl-2-Hydroxymethylpyridiniumjodid;
• N,N-Dimethylpiperidiniumjodid;
• N,N'-Dimethylpyraziniumfluorsulfat und
• y-Picoliniumhydrogensulfat.

Suitable bleach accelerators (f) are e.g. B. quaternary ammonium salts as are known from German Offenlegungsschriften 2 139 401 and 2 716 135. These are preferably quaternary, optionally substituted piperidine, piperazine, pyrazine, quinoline or pyridine compounds, the latter being preferred. Tetraalkylammonium compounds (alkyl having 1 to 4 carbon atoms) and alkylenediammonium compounds (alkylene having 2 to 6 carbon atoms) can also be used. The following are mentioned in detail:

• G _J tetraethylammonium iodide; (CH ₃ ) ₃ N (CH ₂ ) ₂ N (CH ₃ ) ₃ 2J ^e ;
• (CH ₃ ) ₃ N (CH ₂ ) ₆ N (CH ₃ ) ₃ .2J ^- , N-methylpyridinium iodide;
• N-methylquinolinium iodide;
• N-hydroxyethyl pyridinium chloride;
• N-hydroxypropyl pyridinium bromide;
• N-methyl-2-hydroxymethylpyridinium iodide;
• N, N-dimethylpiperidinium iodide;
• N, N'-dimethylpyrazinium fluorosulfate and
• y-picolinium bisulfate.

Further bleaching accelerators are the water-soluble tertiary phosphines known from DE-OS 2 651 969, which preferably contain at least one cyanoethyl group.

worin W ―C_rH_2rCN, -C_rH_2rN0₂ oder ein gegebenenfalls substituierter Arylrest oder ein heterocyclischer Rest, r 1 bis 25, X gegebenenfalls substituiertes Alkyl und Y Hydoxyalkyl, Alkoxyalkyl, Sulfoalkyl, Aminoalkyl (Alkyl je 1 bis 25, vorzugsweise 2 bis 4 Kohlenstoffatome), Phenyl, Sulfophenyl oder Pyridyl ist. Bevorzugte tertiäre Phosphine entsprechen der Formel

worin X, -CH₂CH₂CN oder -(CH₂)₂OCH₃, Y₁ -(CH₂)₂SO₃M, -(CH₂)3-SO₃M, -(CH₂)₄-SO3M, -(CH₂)₂OCH₃ oder -CH₂N(C₂H₅)₂, W₁ -CH₂CH₂CN oder Phenyl und M⁺ ein Kation, insbesondere ein Alkalimetallkation, z. B. das Natrium- oder Kaliumkation, ist.They correspond to e.g. B. the formula

wherein W ―C _r H _2r CN, -C _r H _2r N0 ₂ or an optionally substituted aryl radical or a heterocyclic radical, r 1 to 25, X optionally substituted alkyl and Y hydoxyalkyl, alkoxyalkyl, sulfoalkyl, aminoalkyl (alkyl each 1 to 25 , preferably 2 to 4 carbon atoms), phenyl, sulfophenyl or pyridyl. Preferred tertiary phosphines correspond to the formula

wherein X, -CH ₂ CH ₂ CN or - (CH ₂ ) ₂ OCH ₃ , Y ₁ - (CH ₂ ) ₂ SO ₃ M, - (CH ₂ ) 3-SO ₃ M, - (CH ₂ ) ₄ -SO3M , - (CH ₂ ) ₂ OCH ₃ or -CH ₂ N (C ₂ H ₅ ) ₂ , W ₁ -CH ₂ CH ₂ CN or phenyl and M ⁺ a cation, in particular an alkali metal cation, e.g. B. is the sodium or potassium cation.

• Bis-(β-cyanoäthyl)-2-sulfoäthylphosphin (Natriumsalz),
• Bis-(,β-cyanoäthyl)-3-sulfopropylphosphin (Natriumsalz),
• Bis-(,β-cyanoäthyl)-4-sulfobutylphosphin (Natriumsalz),
• Bis-(,β-cyanoäthyl)-2-methoxyäthylphosphin,
• Bis-(2-methoxyäthyl)-(ß-cyanoäthyl)-phosphin,
• (ß-cyanoäthyl)-phenyl-3-sulfopropylphosphin (Natriumsalz),
• (ß-cyanoäthyl)-phenyl-2-methoxyäthylphosphin und
• Bis-(2-methoxyäthyl)-phenylphosphin.

The following connections are mentioned in detail:

• Bis- (β-cyanoethyl) -2-sulfoethylphosphine (sodium salt),
• Bis - (, β-cyanoethyl) -3-sulfopropylphosphine (sodium salt),
• Bis - (, β-cyanoethyl) -4-sulfobutylphosphine (sodium salt),
• Bis - (, β-cyanoethyl) -2-methoxyethylphosphine,
• Bis- (2-methoxyethyl) - (ß-cyanoethyl) phosphine,
• (ß-cyanoethyl) phenyl-3-sulfopropylphosphine (sodium salt),
• (ß-cyanoethyl) phenyl-2-methoxyethylphosphine and
• Bis (2-methoxyethyl) phenylphosphine.

The repetition of individual treatments (in each case in a further tank with a bath of the same composition as the previous one) is possible, whereby in some cases better use of the bath can be achieved. If the number of available tanks and the time program allow it, water baths can also be used between baths with different effects. It is up to the person skilled in the art to determine the optimal quantitative ratio depending on the type of the selected catalysts from the sensitometric results. All baths can contain other common additives such as. B. contain hardening agents, wetting agents, optical brighteners or UV protection agents.

Baths of conventional composition can be used for silver development, e.g. B. those containing hydroquinone as developer and optionally additionally 1-phenyl-3-pyrazolidinone. The silver development bath may already contain a bleaching catalyst.

The silver fixing bath can be composed in a known and customary manner. As a fixing agent z. B. sodium thiosulfate or advantageously ammonium thiosulfate, optionally with additives such as sodium bisulfite and / or sodium metabisulfite. The fixing bath can also be combined with the bleaching bath as a so-called bleach-fixing bath.

• (a) Säureaddukt: 10 bis 200 g/I;
• (b) Komplexierungsmittel: 2 bis 50 g/I, vorzugsweise 5 bis 25 g/I;
• (c) mindestens einen Bleichkatalysator: 0,05 bis 10 g/I;
• (d) gegebenenfalls ein Oxydationsschutzmittel: 0,5 bis 10 g/I;
• (e) gegebenenfalls ein wasserlösliches Oxydationsmittel: 1 bis 30 g/I;
• (f) gegebenenfalls einen Bleichbeschleuniger: 1 bis 5 g/I.

The aqueous bleaching preparations used generally contain components (a) to (f) in the following amounts:

• (a) Acid adduct: 10 to 200 g / l;
• (b) complexing agent: 2 to 50 g / l, preferably 5 to 25 g / l;
• (c) at least one bleaching catalyst: 0.05 to 10 g / l;
• (d) optionally an antioxidant: 0.5 to 10 g / l;
• (e) optionally a water-soluble oxidizing agent: 1 to 30 g / l;
• (f) optionally a bleaching accelerator: 1 to 5 g / l.

The temperature of the bleaching baths is generally between 20 and 90 ° C, preferably between 20 and 60 ° C, the processing time required being of course shorter at a higher temperature than at a lower temperature. The bleaching baths are stable within the specified temperature range. In general, the aqueous bleaching preparations required for processing are used in the form of dilute aqueous solutions which contain the components mentioned. However, other methods are also conceivable, e.g. B. application in paste form.

This temperature range also applies to the other processing steps. The aqueous bleaching preparation according to the present invention can e.g. B. from solid or liquid, in particular aqueous concentrates of individual or all components ((a) to (f)). One advantageously uses z. B. a solid and a liquid or two liquid concentrates, one of which contains the acid adduct (a) and the oxidizing agent (e) and the other of which contains the other components (b), (c) and optionally (d) and (f), where in the latter concentrate to improve the solubility, in particular component (c), an additional solvent such as ethyl or propyl alcohol, ethylene glycol methyl or ethyl ether can be added. These concentrates (partial concentrates), which are also the subject of the present invention, have excellent stability and can therefore be stored for a long time. These concentrates can optionally be used after dilution with water or with a mixture of water and an organic solvent.

The concentrates of the individual or all components (a) to (c) and optionally (d) to (f) or their combinations, e.g. B. from component (a) and (e) and from components (b), (d), (c) and (f) can be 2 to 20 times, preferably 5 to 1 times the amount of the individual components per liter contain concentrated preparation as previously stated for the ready-to-use bleach baths. They are usually available as solid, liquid or pasty concentrates.

For the first time, there is the possibility of using mineral acid-containing bleaching preparations in the form of solid concentrates with their known advantages for transport and storage instead of liquid concentrates.

The inventive method for processing exposed and developed silver color bleaching materials can, for. B. in the production of positive color images in copiers or automatic recorders or in the rapid processing of other silver color bleaching materials such. B. for scientific records and industrial purposes, e.g. B. colored screen photography can also be used for the production of color negatives and diffusion transfer images.

A transparent, metallic reflecting, or preferably white-opaque material, which is unable to absorb any liquid from the baths, can be used as a support for photographic materials to be processed.

The carrier can for example consist of optionally pigmented cellulose triacetate or polyester. If it is made of paper felt, it must be coated on both sides or coated with polyethylene. The light-sensitive layers are located on at least one side of this support, preferably in the known arrangement, i. H. a red-sensitized silver halide emulsion layer containing a blue-green azo dye on the bottom, a green-sensitized silver halide emulsion layer containing a purple azo dye above and a blue-sensitive silver halide emulsion layer containing a yellow azo dye above. The material can also contain sub-layers, intermediate layers, filter layers and protective layers, but the total thickness of the layers should generally not exceed 20 mm.

The inventive method is particularly suitable for processing exposed silver color bleaching material, which has a special structure and z. B. is suitable for producing self-masked images (DE-OS 2 547 720).

In the examples below, parts and percentages are by weight unless otherwise stated.

example 1

• Auf einen weiß-opaken Träger werden in der angegebenen Reihenfolge die folgenden Schichten aufgetragen:
• Ein rotsensibilisiertes Schichtpaar, bestehend aus
  • 1. einer rotempfindlichen Gelatine-Silberbromidjodid-emulsionsschicht mit einem bleichbaren blaugrünen Azofarbstoff der Formel (101) mit einem Silbergehalt von 0,144 g Ag/m²
    
  • 2. einer von Bildfarbstoff freien Schicht aus einer rotempfindlichen Gelatine-Silberbromidjodid-Emulsion mit einem Silbergehalt von 0,300 g Ag/m²;
  • 3. eine erste Gelatine-Zwischenschicht;
  • 4. einer grünempfindlichen Gelatine-Silberbromidjodid-Emulsionsschicht mit einem purpurfarbigen bleichbaren Azofarbstoff der Formel (102) und einem Silbergehalt von 0,212 g Ag/m²;
    
  • 5. einer von Bildfarbstoff freien Schicht aus einer grünempfindlichen Gelatine-Silberbromidjodid-Emulsion mit einem Silbergehalt von 0,375 gAg/m2;
  • 6. eine zweite Zwischenschicht, bestehend aus Gelatine mit einem Zusatz von kolloidalem Silber in einer Menge von 0,007 g Ag/m² und einer nicht spektral sensibilisierten unempfindlichen Silberbromidemulsion mit einem Silbergehalt von 0,2 g Ag/m²
    ein blauempfindliches Schichtpaar, bestehend aus
  • 7. einer hochempfindlichen jodidfreien Gelatine-Silberbromidschicht mit einem gelben bleichbaren Azofarbstoff der Formel (103 und einem Silbergehalt von 0,360 g Ag/m²:
    
  • 8. einer farbstofffreien hochempfindlichen Gelatine-Silberbromidjodidschicht mit niedrigem Jodidanteil mit einem Silbergehalt von 0,530 g Ag/m²;
  • 9. eine Gelatine-Schutzschicht.

A material suitable for the production of positive supervisory copies of a positive original for the silver color bleaching process was produced in the following way:

• The following layers are applied to a white opaque support in the order given:
• A pair of layers sensitized to red, consisting of
  • 1. a red-sensitive gelatin-silver bromide iodide emulsion layer with a bleachable blue-green azo dye of the formula (101) with a silver content of 0.144 g Ag / m ²
    
  • 2. an image dye-free layer of a red-sensitive gelatin-silver bromide iodide emulsion with a silver content of 0.300 g Ag / m ² ;
  • 3. a first intermediate gelatin layer;
  • 4. a green-sensitive gelatin-silver bromide iodide emulsion layer with a purple-colored bleachable azo dye of the formula (102) and a silver content of 0.212 g Ag / m ² ;
    
  • 5. an image dye-free layer of a green-sensitive gelatin-silver bromide iodide emulsion with a silver content of 0.375 gAg / m2;
  • 6. a second intermediate layer consisting of gelatin with the addition of colloidal silver in an amount of 0.007 g Ag / m ² and a non-spectrally sensitized insensitive silver bromide emulsion with a silver content of 0.2 g Ag / m ²
    a blue-sensitive layer pair consisting of
  • 7. a highly sensitive iodide-free gelatin-silver bromide layer with a yellow bleachable azo dye of the formula (103 and a silver content of 0.360 g Ag / m ² :
    
  • 8. a dye-free, highly sensitive gelatin-silver bromide iodide layer with a low iodide content and a silver content of 0.530 g Ag / m ² ;
  • 9. a gelatin protective layer.

This material is constructed in such a way that, when processed with a developer containing a silver ligand, in particular sodium thiosulfate, and the subsequent process steps of color and silver bleaching necessary for the silver color bleaching process, the latter preferably combined in a single step, and finally the fixation, a masking of the blue secondary color densities the purple and cyan layer is effected.

A sample strip is cut from this photographic material and exposed additively behind a gray wedge as follows:

The following processing solutions were used in the order given for processing the exposed test strip:

After the subsequent drying, positive gray wedges are obtained which have a uniform neutral gray shade over the entire density range, with D _max values of 1.77 (gray) and D _mm values of 0.03 (gray).

An impairment of the image quality when using the adducts according to the invention of the previously customary free sulfuric acid is not found.

Example 2

The photographic material used in Examples 2 and 3 below is identical to that of Example 1, with the exception of filter layer (6), which this time contains only colloidal silver but no additional unsensitized emulsion. The processing sequence is similar to that of Example 1, but the silver developing solution does not contain sodium thiosulfate, which does not produce a self-masking effect.

A sample strip of the photographic material was exposed additively, similar to that described in Example 1, using the following exposure times:

The following processing solutions were used for the subsequent processing:

The processing temperature was 30 ° C throughout the processing.

A second test strip is exposed in the same way and treated in the same processing solutions, but using a bleaching bath containing 17 ml / liter of 96% sulfuric acid.

• 1,75 Rot
• 1,96 Grün
• 2,05 Blau
  und einem D_mi" von je
• 0,00 Rot
• 0,05 Grün
• 0,08 Blau (Remissionsdichten)

The finished treated and dried test strips give identical sensitometric values, with a D _max of each

• 1.75 red
• 1.96 green
• 2.05 blue
  and a D _{mi "} of each
• 0.00 red
• 0.05 green
• 0.08 blue (reflectance densities)

Example 3

The 9-layer unmasked material used in Example 2 is additively exposed behind a gray wedge in the same way as there and then subjected to a processing sequence with four baths in which a separate bath is used for the successive color and silver bleaching.

The following solutions are used for processing at a temperature of 24 ° C throughout:

A second sample strip is exposed and processed in an identical manner, but using 14 ml of 96% sulfuric acid in the color bleaching solution and 20 ml 96% sulfuric acid in the silver bleaching solution per liter of solution.

The two positive gray wedges obtained in this way corresponded in all sensitometric values. The measured maximum and minimum densities (reflectance densities) are:

Example 4

In this example, using the same dyes as in Example 1, a six-layer material is used which in the first layer contains the cyan dye and the associated red-sensitized silver halide emulsion, and in the second layer a thin, pure gelatin-containing intermediate layer in the third layer contains the purple dye with the associated green-sensitized silver halide emulsion, the fourth layer is an intermediate layer consisting of gelatin, the fifth layer contains a yellow halide silver halide layer and finally the sixth layer contains a protective layer of pure gelatin.

• Kombiniertes Bleich- und Fixierbad
  

For the processing of this material, a so-called two-bath process is selected, consisting of a developer bath and a subsequent combined bath, in which the dye and silver bleaching and the fixing take place practically simultaneously. An identical bath as in Example 3 is used as the silver developing bath; the combined bleaching and fixing bath has the following composition:

• Combined bleaching and fixing bath
  

A second sample strip is exposed and processed in an identical manner, but using a combined bleaching and fixing bath which contains 9.5 g / l of 96% sulfuric acid.

The finished and dried test strips each result in a positive gray wedge with identical sensitometric values. The measured densities (reflectance values) are:

Example 5

Concentrate for the preparation of a combined color and silver bleach bath.

A preparation consisting of a solid and a liquid partial concentrate is prepared as follows:

• Man vermischt
  

Production of a combined color and silver bleach bath:

• You mix
  

Example 6

A further preparation of a combined color and silver bleach bath consists of the following two fixed partial concentrates:

A combined color and silver bleach bath is prepared by dissolving part 111 and part IV in 900 g of water.

Claims (13)

1. A method of processing exposed and developed photographic silver dye-bleach materials, which comprises treating the exposed and developed material with aqueous bleaching preparations which contain

(a) an acid component,

(b) a silver-complexing agent,

(c) one or more bleach catalyts,

(d) optionally an antioxidant,

(e) optionally a water-soluble oxidising agent and

(f) optionally a bleaching accelerator,

wherein component (a) is a water-soluble adduct of an acid amide of a C₁―C₄ aliphatic acid or of a monocyclic aromatic acid or of a diamide of carbonic acid or thiocarbonic acid or of a lactam of y-, 6- or r-aminoacids and a strong mineral acid.

2. A method according to claim 1, wherein the aqueous bleaching preparations are dye-bleaching or silver-bleaching baths, combined dye-bleaching and silver-bleaching baths or bleach-fixing baths.

3. A method according to claim 1, wherein component (a) is an adduct of urea and 0.5 or 1 mole of sulfuric acid, or of urea with 1 mole of nitric acid.

4. A method according to claim 1, wherein component (b) is thiourea or a water-soluble iodide, component (c) is a pyrazine, quinoxaline or phenazine compound, component (d) is a reductone or a water-soluble mercapto compound or an alkali metal, alkaline earth metal or ammonium bisulfite adduct of an organic carbonyl compound, component (e) is an aromatic mononitro or dinitro compound or an anthraquinonesulfonic acid and component (f) is a quaternary, substituted or unsubstituted piperidine, piperazine, pyrazine, quinoline or pyridine compound or also a tetraalkylammonium or alkylenediammonium compound.

5. A method according to claim 1, wherein water-soluble tertiary phosphines of the formula

in which W is-C_rH_2rCN,-C_rH_2rNO₂ or a substituted or unsubstituted aryl radical or a heterocyclic radical, r is 1 to 25, X is substituted or unsubstituted alkyl an Y is hydroxyalkyl, alkoxyalkyl, sulfoalkyl, aminoalkyl, phenyl, sulfophenyl or pyridyl, are used as components (f) and/or (d).

6. An aqueous preparation for processing exposed and developed photographic silver dye-bleach materials, which contains

(a) an acid component,

(b) a silver complexing agent,

(c) one or more bleach catalysts,

(d) optionally an antioxidant,

(e) optionally a water-soluble oxidising agent and

(f) optionally a bleaching accelerator,

wherein component (a) is a water-soluble adduct of an acid amide of a C_l-C₄ aliphatic acid or of a monocyclic aromatic acid or of a diamide of carbonic acid or thiocarbonic acid or of a lactam of y-, α- or r-aminoacids and a strong mineral acid.

7. An aqueous preparation according to claim 6, wherein said aquous preparation is a dye-bleaching or silver-bleaching bath or a combined dye-bleach and silver-bleach fixing bath.

8. An aqueous preparation according to claim 6, wherein component (a) is an adduct of urea and 0.5 or 1 mole of sulfuric acid, or of urea with 1 mole of nitric acid.

9. An aqueous preparation according to claim 6, wherein component (b) is sodium iodide, potassium iodide or ammonium iodide, component (c) is a pyrazine, quinoxaline or phenazine compound, component (d) is a reductone or a water-soluble mercapto compound or an alkali metal, alkaline earth metal or ammonium bisulfite adduct of an organic carbonyl compound, component (e) is an aromatic mononitro or dinitro compound or an anthraquinonesulfonic acid and component (f) is a quaternary, substituted or unsubstituted piperidine, piperazine, pyrazine, quinoline or pyridine compound or also a tetraalkylammonium or alkylenediammonium compound.

10. An aqueous preparation according to either claim 6 or claim 7, which contains 10 to 200 g/I of component (a), 2 to 50 g/I of component (b), 0.05 to 10 g/I of component (c), optionally 0.5 to 10 g/I of component (d), optionally 1 to 30 g/I of component (e) and optionally 1 to 5 g/I of component (f).

11. A concentrate for the production of an aqueous preparation according to any one of claims 6 to 10, which contains components (a) to (c) and optionally (d) to (f) in a concentration, per litre of concentrate, which is 2 to 20 times higher than the concentration in a ready-for use aqueous preparation.

12. Partial concentrates forthe production of an aqueous preparation according to any one of claims 6 to 10, which comprise a first concentrate containing components (a) and (e) and a second concentrate containing components (b), (c) and optionally (d) and (f), the concentration of the components per litre of concentrate being 2 to 20 times higher than that in a ready-for-use aqueous preparation.

13. A process for the preparation of an aqueous bleaching preparation according to any one of claims 6 to 10, which comprises diluting a concentrate or partial concentrate according to either claim 11 or claim 12 with water, or with a mixture of water and an organic solvent, to the concentration required for use and optionally mixing them.