JPS6228459B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for preventing dark coloration and sludge formation in photographic developers.

Silver halide-containing photographic materials are mainly developed in alkaline media, using o- or p-dihydrobenzene, aminophenols, diaminobenzenes, pyrazolidinones, reducutones or hydroxylamine derivatives as developing substances. Developer solutions often also contain additives such as sulfates as stabilizing, antifogging and buffering agents. Furthermore, it is known that in certain cases photographic materials are developed in the presence of silver halide solvents.
Such silver halide solvents include, for example, mercapto compounds, thioethers, thioamides or acidic -CH
--containing compounds, such as organic divalent sulfur compounds such as bis-methylsulfonylmethane, as well as rhodanhydrogen salts, highly concentrated sulfites, and especially thiosulfites. Developers containing such additives are known as particulate developers and internal particle developers. (“Negative and positive processing techniques” by E. Muzter,
(See Springer 1955, pp. 158-159) The development of latent silver buds within the grains is of particular significance in reversal development processes, where several times as much rhodan hydroxide is lost in the first development. The broad implementation of this process is one bath as described in US Pat. No. 3,857,710 or G. Heist's "One Bath Manual", Morgan 1960. Another implementation of this method is published in the German Open
This is a mask developer for the silver color bleaching method as described in No. 2547720.

This large number of developers, however, has the disadvantage that they more or less rapidly reduce the silver halide eluted from the photographic material in a complex manner. Therefore, a contamination occurs in the developer and after a while turns into a silver sludge, which sticks to the photographic material as well as to some parts of the developer tools. This silver slurry is particularly disadvantageous in continuous operation equipment.
Attempts to find suitable measures against this silver mud formation have not been successful.

German Published Application No. 2437353 proposes the use of 1-phenyl-5-mercaptotetrazole derivatives in X-ray film developers to prevent silver precipitation in developer solutions. U.S. Patent No. 3173789 and German Patent Publication No. 1175077 and German Published Application No. 1175077
No. 2003414 describes that a heterocyclic mercapto compound is added, and German Publication No. 1909743 describes that an aliphatic mercapto-carboxylic acid is added to the processing solution to prevent the formation of silver mud. U.S. Patent No. 3318701
The issue includes α-liponic acid and German Open Gazette.
No. 2040801 has 4-acylamino-1,2,3-
Triazoline-5-thione has been proposed for preventing sludge formation. These substances are mostly added in amounts of 5 to 5000 mg per liter of developer.

While it is clear that these proposed additives can retard silver mud development for a period of time, they have various undesirable side effects. Substances with good transparency properties have a considerable influence on developer properties. In multilayer color materials, the sensitivity is reduced, especially of the top layer. In the mask development of silver color bleaching materials, interference with the mask effect appears. Other materials are unstable in the developer and rapidly lose effectiveness or decompose due to air oxidation, producing malodorous and/or harmful by-products. All these drawbacks have considerably hindered and in many cases made impossible the practical application of the transparency-retaining materials proposed so far. German Published Publication No. 2640659 states that a specific organic di- or tri-
Development methods using sulfides are described.

These di- and tri-sulfides are most well suited for clarity preservation and prevention of silver mud formation in photographic developers; however, they are difficult to obtain synthetically and require a considerable amount in the developer to achieve the desired effect. The disadvantage is that it requires a large amount.

Therefore, it is an object of the present invention to establish a new method for preventing dark coloration and sludge formation in photographic developing solutions, which can broadly eliminate the obstacles to photographic development.

It has now been discovered that this problem can be solved by adding a mixture of mercapto compounds and Bunte salts to the developer solution.

DE 1768400 describes the application of Bunte salts, for example as stabilizers of silver halide emulsions or for the purpose of stabilizing developed photographic materials. In contrast, according to the present invention, Bunte salts are added to developer solutions mixed with mercapto compounds and for other applications.

The object of the present invention is to provide a method for preventing dark coloration and sludge formation in a photographic developer containing a silver halide developable compound, a water-soluble silver halide solvent, and an organic sulfur compound. However, R is phenyl or lower alkyl, and a compound having the formula (b) However, R' is phenyl or lower alkyl,
M is hydrogen or an alkali metal, or a mixture of amino(lower)alkanethiosulfonic acids or alkali metal salts thereof is added.

The organic sulfur compound added to the developer in the present invention is a mixture of the above (a) and (b). Examples of the lower alkyl of R and R' include methyl, ethyl, propyl, etc., and examples of the alkali metal salt include sodium salt, potassium salt, etc. Further, examples of the amino (lower) alkanethiosulfonic acid include aminoethylthiosulfonic acid and the like.

Preferred aqueous developer solutions which can be used in accordance with the invention for developing image-exposed photographic materials will furthermore present compositions known per se.

The developer solution contains conventional silver halide development compounds such as dihydroxybenzene, aminophenol, diaminobenzene, pyrazolidinone, reducutone or hydroxylamine derivatives.

Common water-soluble silver halide solvents include, for example, thioethers or thioamides, rhodan hydroxide,
There is a high concentration of sulfite, preferably thiosulfate. Sulphites are added to the aqueous formulation, for example, generally in amounts of more than 20 g/, sometimes even in small amounts, such as 10 to 20 g/, and thiosulfates in concentrations of 0.1 to 200 g/.

Thiosulfate concentration is 10 to 200g per bath.
is preferably 0.1 to 10 g/in mask development of silver color bleaching materials. Sulfur compounds can also be used in the development formulations of reversal, chromogen, X-ray, or black-and-white film materials.

Components (a) and (b) are 0.01 to 1 g/or 0.1
It is preferable to add it to the aqueous developer solution in an amount of 10 to 10 g/kg.

Suitable developers are therefore e.g. 0.1 to 20
g/g/silver halide developable compound, 0.1 to 200
g/ of silver halide solvent and 0.05 to 10 g/
A mixture of components (a) and (b) in a molar ratio of (a):(b) of 5:1
1 to 1:100, preferably 1:1 to 1:20.

It is advantageous to mix the mixtures of (a) and (b) some time before using the developer in producing the aqueous developer formulation of the invention. The amount relationship of Bunte salt to mercapto compound can vary within the above ratios.

The mixture of mercapto compound and Bunte salt used in the present invention is particularly excellent in preventing silver separation in a developer for a long time. Furthermore, in contrast to the anti-sludge agents previously used, the mixture of (a) and (b) used in the present invention is inert in photographic practice and is very stable in the usual sense; This is preferable for the continuous development operation described above.

In the following examples, all parts and percentages are by weight.

Example 1 In a red sensitized subbing layer on a pigmented cellulose acetate support, the formula: A blue-green image dye with the formula: In the violet dye with the formula: A photographic material for a silver color bleaching process was produced containing a yellow dye with .

The photographic materials used were constructed as follows. (German Publication No. 2036918, 2132836 and
(See No. 2547720) Gelatin protective layer Blue-sensitive, non-iodide, AgBr emulsion yellow dye (103) + blue-sensitive non-iodide, AgBr emulsion yellow Filter: Yellow Ag-hydrosol (40mg/
m ² ) Green-sensitive AgBr/AgI - emulsion purple dye (102) + green-sensitive AgBr/AgI - emulsion intermediate layer (gelatin) blue-green dye (101) + red-sensitive AgBr/AgI - emulsion red-sensitive AgBr/ AgI - emulsion cellulose acetate support, white opaque backing layer, gelatin This layer configuration allows correction of the blue extra color density of blue-green and violet dyes by additional bleaching of the yellow image dye in accordance with other two-image dye bleaches. Make it. (The blue-sensitive layer has a yellow dye-free iodide emulsion; the remaining dye layers have iodide-containing emulsions.) The budded layer is adjacent to the yellow dye layer. This is separated from the violet layer by a colorless emulsion layer which additionally contains a yellow overdye (a green-sensitive AgI-containing emulsion layer and at the same time a separating layer).

The iodide-containing emulsion layer has crystals containing 2.6 mole percent silver iodide and 97.4 mole percent silver bromide. The image dye is used in such a concentration that its permissible concentration is always 2.0, ie the total silver content of a 22 micron thick layer is 2.0 g/m ² .

Color transparencies were printed onto this material in an enlarger. The exposed material was treated according to the following criteria (French Patent No. 2247755). In this case, the treatment temperature was 30°C.

1 Silver developing bath 3 minutes Ethylenediaminetetraacetic acid tetrasodium salt
2g/ Potassium hydroxide 85% 30g/ Boric acid 16g/ Potassium metabisulfite 26g/ 1-phenyl-3-pyrazolidinone 0.35g/ Hydroquinone 5g/ Benztriazole 0.8g/ Potassium bromide 2g/ Anhydrous sodium thiosulfate 0.8g/ Formula ( 104) 0.5g/ Compound (105) 0.85g/ 2 Wash with water for 1 minute 3 Bleach bath for 5 minutes Sulfamic acid 100g/m-nitrobenzole sodium sulfonate
10g / 1-thioglycerin 1ml / Potassium iodide 6g / 2,3,6-trimethylquinoxaline 2g / 4 Washing with water 1 minute 5 Fixing bath 4 minutes Ammonium thiosulfate 250g / Potassium metabisulfite 50g / Potassium hydroxide 85% 20g/6Water wash 6 minutes Total operating time 20 minutes Test prints of the transparencies obtained after drying were particularly good in terms of intact tonal reproduction and accurate color reproduction.

Development requires longer times due to the addition of two compounds (with formulas (104) and (105)). The developer remained clear even after multiple color stretching operations, ie, no silver metal separation occurred.

If only the compound having formula (104) is added to the developer, the solution will remain transparent for a long enough time, but the developer properties will change and the yellow blur in the shadows will flatten out in the developed color photographic material, thereby reducing the blur. I lost my balance. Color prints processed with this developer do not give a satisfactory yellow tone. Moreover, dark image areas once had a blue tint.

When the developer contained only the compound having formula (105), the solution became colored and the metallic silver was separated within a short time after use.

Instead of the mixture of compounds with formulas (104) and (105), other combinations of mercaptans and Bunte salts shown in the table above can also be used.

Example 2 A silver color bleaching material was treated according to the method of Example 1, except that the formula: Compounds with 100% were added to a silver developing bath.

The development time was 2 minutes at 30°C. Test prints with good quality images were obtained after drying. No change in image quality or contamination of the solution was observed even with repeated use of the developer solution (total of 0.1 m ² of material per liter of solution).

Example 3 A black and white developer was produced with the following formulation: Potassium carbonate 30g Sodium sulfite 100g Potassium bromide 3g Hydroquinone 40g Ethylenediamine-tetraacetic acid disodium salt
1.5g Potassium hydroxide 17g Add water to make a total volume of 1. Divide the solution into two, A and B, each 500ml. 0.5 g of the compound having formula (104) was added to A, and 0.5 g of 2-aminoethane-thiosulfonic acid and 0.5 g of the compound having formula (104) were added to B.

Both solutions were used to develop black and white camera film. Part A remained transparent for a while, but soon became cloudy due to silver mud. The developability of this solution was changed as in Example 1 above. On the other hand, portion B remained transparent and maintained good developability even after long-term use.

Example 4 The following formulation: 2 g of 4-methylaminophenol sulfate 5 g of hydroquinone 100 g of sodium sulfite (anhydrous) 3 g of borax Add 0.5 g of the compound having the formula (104) to a black and white developer having a total volume of 1.
0.85 g of a compound having formula (105) was added and mixed.

Use this solution in the tank to make 20 black and white camera films.
Developed at ℃ for 6 minutes. After developing all 10 rolls of 135-inch film with 36 exposures each, the solution began to run out and it became necessary to replace it with new solution or add new solution. Contrary to the developer prepared without adding compounds having formulas (104) and (105), no trace of silver mud was observed up to this point.

Claims (1)

[Claims] 1. Formula (a) is added to the developer. However, R is phenyl or lower alkyl, and a compound having the formula (b) However, R' is phenyl or lower alkyl,
M is hydrogen or an alkali metal, or a silver halide developable compound, a water-soluble silver halide solvent, and an organic A method for preventing dark coloration and sludge generation in photographic developers containing sulfur compounds.