DE1472741A1 - Process for producing color photographic images - Google Patents

Description

AGFA-GEVAERTAG ι

472741

LEVERKUSEN Za / ed. 23. August 1968 Process for producing color photographic images

The invention relates to a method for producing colored images by the silver color bleaching process, wherein the silver image required to bleach the azo dyes is produced using the silver salt diffusion process.

It is known to produce photographic layers by the silver dye bleaching process. This is assumed to be homogeneous colored, preferably azo-dye-containing layers of, which also contain a silver picture. In a usually strongly acidic bleaching bath, the. Make the picture silver wear, the dye image-wise bleached, so that after further treatment steps, such as bleach-fixation or residual silver bleaching and fixation, a pure dye image remains.

This procedure can be carried out in various ways depending on whether a positive (reverse image) or an image running in the opposite direction in the gradation is required.

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In the first case, nan works in such a way that the silver image in the dye layer is created by a simple negative development of the silver halide originally present in it is produced. After the development of most of the image silver, the la is then created in the places with the highest exposure The color bleaching progresses to complete dye destruction, d. H. in turn leads to image whites in the fezrtl & n copy (Ba * reversing image). If the silver image is generated by a black-and-white reverse development, the color image created after the color bleaching has a gradation opposite to the original, d. H. if this original is a color negative »one creates a positive copy, conversely a color negative, if the Original is a positive. Since the photosensitive layer containing halogen silver must be colored with the (azo) dye, its sensitivity is already reduced so much by the filter effect that the process is only used for copying purposes can be considered.

The production of colored positive reflective images or slides by the silver color bleaching process starting from color negatives is of particular importance because the predominant The majority of all color images are still produced from color negatives and, on the other hand, the use of azo dyes The production of particularly lightfast copies is permitted in the silver color bleaching process.

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There have therefore already been described several methods of murders; do color images with a gradation opposite to the original using the silver color bleaching process. For example, British Patent 453 6γ4 describes the generation of a silver reversal image in azo dye layers in the manner of normal black and white reversal development. However, this procedure and the procedure based on it (e.g. according to German Auslegeschrift 487) are cumbersome and lengthy.

As a shortcut in the production of the silver reversal image, the bromine ion diffusion process has therefore already been proposed

to use, according to the German Auslegeschrift 1 18l o55 A direct positive silver image can be produced in just a few steps.

However, all of the above-mentioned processors have the disadvantage that by adding the azo dye directly to the emulsion layer, its sensitivity is greatly reduced, which on top of that, the choice of available emulsions is severely limited in terms of their graininess and gradation.

In the U.S. Patent 2,673,800 will manufacture of color photographic images by a method in which the silver salt diffusion method is combined with the silver color bleaching process, using photographic materials with double-layer elements used, which are constructed as follows;

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A development seed stained with an azo dye containing layer is sensitized to the respective (azo) dye accordingly photosensitive Halogen silver emuleion overcoated. In the exposure is therefore not a decrease in sensitivity due to light absorption by the dye in the area of sensitization of halogen silver possible.

When developing in an alkaline, halogenated silver solvent Developer is created by diffusion of the unexposed silver halide into the one containing the azo dye Seed layer creates a direct positive silver image. In the subsequent parbleaching, the silver image becomes strong acidic bath destroys the dye image-wise. The result is a color image with a gradation opposite to the original.

Another advantage of this method is that the generation of the silver reversal image is extraordinary in a short time and in a simple manner by development and subsequent fixing development or directly by fixing development can take place and that the silver deposited on the germs is characterized by great fineness and surface. As a result, the color bleaching takes place considerably more quickly and with a better yield than what is normally eliminated by photographic means Silver.

The small amounts of common developer germs, such as silver sulfide, NickeisulfId ', colloidal silver, colloidal nickel and others, the are added to the dye layer, do not interfere and are developed in the course of the processing stages following the development.

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far away.

The practical applicability of the last-mentioned process suffers from an unsatisfactory color separation especially when used in a multi-layer dressing

It has now been found that this disadvantage can be avoided when a separating layer is provided between the photosensitive silver halide emulsion layer and the non-photosensitive top layer containing the silver nuclei and the dye.

The usual binders are suitable as binders for this layer hydrophilic film-forming agents, such as gelatin, which can be wholly or partially replaced by, for example, alginic acid or their derivatives, polyvinyl alcohol, polyvinyl pyrrolidone, carboxyalkyl cellulose such as carboxymethyl cellulose and the like.

The separating layers preferably have a thickness of 0.2 -3 / U. Layer thicknesses of 0.4 and 1.5 / U proven

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The inventive method can be in the most varied Catfish are varied. Thus, silver halide layers can optionally contain silver chloride, silver chlorobromide or silver bromide with an addition of silver iodide. Also can during the emulsion production Mstallionen, such. B. Salts of copper, cadmium, lead, iridium, rhodium and others. be added. The use of silver bromide emulsions is preferred. In addition, these emulsions can all also be otherwise customary Contain additives such as hardeners, e.g. B. formaldehyde, chloromuconic acid, Faraformaldehyde, chrome alum, wetting agents such as saponin or sulfosuccinic acid, ripening bodies of various kinds, softeners such as glycerine, anti-fog agents such as hydroxylamine or other stabilizers. Because of the high demands The strength of the layers in the course of the treatment in the strongly acidic dye bleaching baths will ensure good curing the emulsion layer is preferred, as is the underlying dye seed layer.

In the production of color separations or multilayer materials for color photography comes the sensitization of the color layers particular importance to. It is known that for layers after the silver dye bleaching process, in which the Azo dyes are incorporated into the emulsion layer, there are considerable restrictions, so that, for. B. basic Cyanine not or only with a low sensitization effect

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can be set. Sensitizing dyes are preferred e from the class of merocyanines, as z. Am

the German patents (application A 45 221

IXa / 57b) or (application A 47 4 ^ 1 IXa / 57b) for

azo dye-containing layers are described, and sulfobetaine cyanines.

Since the type of production of the silver image is of little importance for further processing according to the silver dye bleaching process, all further process modifications known from the literature can be used for this purpose.

All dye-bleaching baths, especially those containing acidic quinols, can be used Baths, find use, as described in British Patent 636 622 and the bleach catalysts, such as indophenazine, furoquinoxaline, thionoquinoxaline Contained alone or in combination with other substances, e.g. B. 2,3-dimethylquinoxaline. Acid thiourea baths are in the same way suitable as described in British Patents 597 159 and 507 211, and in US Pat. No. 2,221 are known ago. As bleach catalysts, these baths contain quinoxalines, such as. B. 2,3-Dimethalquinoxaline, Dlamino- and hydroxyaminophenazines, oxazines, thiazines, azines, anthraquinone-ß-sulfonic acids, as well as halides such as chlorides, bromides, iodides or rhodanides as bleach accelerators, sometimes also small amounts of alcohol or other organic solvents. To the

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Color bleaching is also suitable after acid treatment or iodine-iodide baths. A solution of Iron (III) rhodanide can be used, as in the US patent 2 322 o84.

As dyes for the process according to the invention, all types of compounds which can be used for the silver dye bleaching process come into question, such as, in particular, water-soluble mono-, bis- or polyazo dyes, eg. B. according to the German Auslegeschriften 1 okl 355 and 1 039 84o, diffusion-resistant. B. in the Belgian patent specification 615 313 or the German patent specification (Application A 46 855 IXa / 57b). Likewise Phthalocyanines with or without metal atoms are also suitable for this bleachable azo dyes which are soluble in organic solvents and which are incorporated into the photographic layer by emulsification Can be, as well as finely dispersed Azc pigments,. wie she z. B. in the German Auslegeschrift 1 I36 318 specified are. Water-soluble diazo dyes are preferably used, the requirements placed on the dyes in terms of their resistance to oxidizing agents is not particularly significant need to be high, since no acidic, strongly oxidizing lead

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baths, ζ. B. acidic Blohromat baths, as for a normal one Black-and-white reversal development must be passed through.

t for the method can also complex-forming water-soluble or water-insoluble azo dyes are used, the dye- transition metal complexes (with metals of atomic numbers 2k- 29 *, preferably Nl, Cu, Ca) either being used as single dyes or being generated after processing. Examples of such dyes are given in German Auslegeschrift 1 166 621.

Gelatin is preferred as the binder for the photographic layers according to the process of the invention, both for the emulsion base and for the dye seed layer. the Jedooh at least in one of the layers partially or entirely through polyglyoosides, such as innulin, dextrans, omum arabic, starch or their derivatives, in particular esters or ethers, such as partially saponified methyl cellulose, carboxymethyl cellulose, Ethyl cellulose phthalates, polyvinyl alcohols and their esters, copolymers containing hydroxyl groups, alginates, alginic acid esters and others. Binder can be replaced as long as sufficient Durability of the layers is guaranteed;

The substrate for the process is any type of substrate, such as transparent or pigmented films made of esterified cellulose, such as cellulose di- or triacetate, all kinds of polyester,

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special polyethylene terephthalate and polycarbonates with / or without preparation layers «or other synthetic materials, as well as glass or prepared, in particular baryta paper.

All substances that are commonly used in the silver salt diffusion process can be used as development nuclei for the dye seed layer; z. B. colloidal heavy metals, preferably silver or salts of heavy metals. As heavy metal salts, the sulphides or selenides of silver, mercury, zinc, nickel,
Cadmium, cobalt and others have been proven. Organic substances that can form silver sulfide with silver ions, such as, for. B. Thioacetanilld et al. The metal or
Metal sulfide nuclei can be used individually or in mixtures of different anions or cations.

When building multicolor materials according to the new process, the elements (consisting of the emulsion layer and the paraffin seed layer) for the three subtractive primary colors * are separated by intermediate layers, which preferably contain seeds
can to prevent unwanted diffusion of halogen silver. In comparison to the separating layers within the individual elements, these are preferably chosen to be correspondingly thicker. That

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Penetration of the developer from the surface of a multi-pack in the direction of the base has an undesirable effect Opposed to diffusion. The selection of emulsions in black layered materials according to the new process takes place according to the necessary sensitivities and the respective diffusion ratio, which can be influenced, for example, by suitable hardening.

The achievement of suitable gradations for the production of halftone images does not cause any difficulties. In addition, gelatin can be added to the emulsions in the desired amount.

When processing material according to the new invention Several factors play a special role in the process.

So the black and white developer should be as quick and even as possible develop in order to achieve short development times. The developer may contain a silver salt solvent to improve the Allow silver deposition on the nuclei in the dye seed layer. Such additives come, for. B. sodium thiosulfate or other thiosulfates, sulfites, 'rhodanides such as potassium rhodanide or organic bases such as amines of various types. However, development can also be carried out in such a way that development is first carried out without a silver salt solvent and only in a second Level lets a fixing developer act.

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All compounds that are useful for the silver salt diffusion process, such as p-methylaminophenol, p-methylaminophenol + hydroquinone, phenylpyrazolidone + hydroquinone, but also p-phenylenediamine developer with the additions already mentioned.

The development and / or fix development of the photographic Materials can be immersed in liquid solutions, but also by spraying on solutions or by applying Developers ^ ast done.

The development can advantageously be controlled in such a way that the light-sensitive material is wetted with the solution for as long as as is necessary for the swelling of the layers. One lets z. B. a material consisting of emulsion layer and dye seed layer for a short time in developer and leaves it is then suitable for a certain tent in the wet state without further developer supply. The further processing can take place in various ways such that development and / or fixation development is carried out as described and then in one. acidic bath is stopped (e.g. in 2 liters of acetic acid), so that it then sets and hardens (e.g. in 2% formaldehyde solution) and then the color bleaching and bleaching of the remaining silver as well as the fixation, or that one under Leaving out one or more baths between the fixing developer and the color bleaching bath immediately after developing the color bleaching carries out. This is followed by residual silver and silver halide

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in "in" Blelohflxlerbad * as for the azo silver dye bleaching process, e.g. B. in the German Auelegeschrift 1 o4l 355, Example 1 described »removed. In this way one achieves a * considerably simpler and shorter processing than with the . silver color bleaching processing carried out in the usual catfish.

Surprisingly, for the process according to the invention Such seed soles are advantageous for the precipitation of the overdiffusing silver halide which are practically unsuitable for the usual silver salt diffusion process for the production of office copies. OEM of this preferred embodiment therefore seed layers are used which contain the usual precipitation nuclei in a particularly fine distribution, so that a silver image of yellowish to brownish color, the conventional processing would be unusable. Such silver images have a particularly high bleaching effect on the Azo dyes present in the Kelmsohlcht and lead to extremely sharp images with a high degree of resolution. Since the beneficial range of germs is due to the lack of suitable ones Meta methods can practically not be specified, must be the production of such seed layers in a known manner, the conditions are varied so that the finest possible seeds arise until silver images are obtained in the desired yellowish to brownish tune.

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It has also been found that a certain layer thickness ratio is advantageous for the light-sensitive halogen silver emulsion layers and the associated seed layers containing azo dye. This ratio of light-sensitive layer to seed layer is said to be advantageous. · May be 5: 1 to 2: 1. To be particularly favorable layer ratios of 5 '1 to 3 * 1 have shown.

The execution of the method according to the invention is described below explained with a few examples.

example 1 On a base made of clear cellulose triacetate with The following layers are warped for the preparation layer:

1. a layer made from a solution containing 8 % gelatin and 4.5 g per liter of the dye of the formula

OC ₂ H ₄ OC ₂ H ₅

Ν »Ν

OC ₂ H ₄ OC ₂ H ₅

SO ₃ H SO ₃ H

contains, its representation in the German Auslegeschrift 1 o4l 355 is described, as well as Io mg of colloidal silver sulfide in addition to the usual amounts of hardening and wetting agents. Of the

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The application is measured in such a way that the dye density behind the red filter is about 0.9 in transparency.

2. A separating layer of about 1 / u thickness made of gelatin, which is produced by coating with a 6 ^ strength gelatin solution will.

'' Means a layer that g per liter about 2o a Sllberbromid Emulslon-known type and network and curing agent ent holds and that of a red sensitizer added Jo mg / l

is like it in the German patent specifications

(Registration A 45 221 IXa / 57b) and (Registration

A kj 451 I3Sa / 57b), Example 11. In the case of a single color separation, the sensitizer can also be omitted.

After potting, it is dried, exposed behind a gray step 11 (depending on the visual sensitization with white or red light) and processed as follows: ^

1. Develop 1 minute in a composition developer t

NaOH Io G NaSuIfit sice. 80 G Hydroquinone 15th G Phenidone 1 G KBr 2 G Na ₂ S ₂ O, .5H ₂ O 2o G

H ₂ O on 11

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2. Dwell time 1 minute.

3. Stop in 2% acetic acid for 1 minute.

4. Fixing for 2 minutes in an acidic fixing bath containing!

2oo g of sodium thlosulphate crops.

20 g of potassium metabisulphite in 100 ml of water.

5. Whats 2 minutes.

6. Color bleaching in an acidic bleach bath for 5 minutes as follows Composition:

8o g

Io g

Io g. 75 ml 11

7. Soaking 3 minutes.

8. Silver bleaching for 2 minutes in a bath

Copper chloride crystall. 5o g Potassium bromide 50 g hydrochloric acid conc. Io ml of water to looo ml

9. Fixation for 8 minutes in a bath as under 4, Io. Final soak 15 minutes.

After drying, the result is a neatly graduated blue-green image with sharp edges, the gradation of which is opposite to the original is.

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Quinoline PO ₂ KJ u conc. NaH ₂ on H ₂ SO H ₂ O

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If

Example 2

The procedure is as in Example 1, but the layers are applied to a base made of corrugated cellulose triacetate and a thin intermediate layer of 2% gelatin solution with the usual wetting and hardening agents is drawn between the emulsion and dye seed layer.

The processing takes place as follows (baths as in example 1, unless otherwise noted):

1. Development 1 minute,

2. dwell time 1 minute,
3- soak for 2 minutes,

4. color bleaching 3 minutes,
5 watering for 3 minutes,

6. Bleach-fix io minutes in a bath

26 g of tetra-sodium ethylenedlamine tetra-acetate, 24 g of soda sicc, 15 g of iron (III) chloride, krlst. 13 g sodium sulfite sicc, and 2oo g sodium thiosulfate , kr ist., In looo ml water,

7. Final soak for 20 minutes.

After drying, the same dye image is obtained as in Example 1, but with even better whites.

Example 3

The procedure is as described in Example 1 or 2, but used in place of the quinoline-sulfuric acid bath during processing

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IV

an acidic thiourea bath of the following composition: 28 g of thiourea
l8 g potassium bromide
4oo ml hydrochloric acid conc.

3 mg of 2-hydroxy-3-aminophenazine

The color bleaching is then carried out for 2 minutes, if one. works according to example 1, or 2 minutes according to example 2. After drying, the same result is obtained as in the previous examples.

Example 4

The procedure described in Example 2 is followed Dye seed layer but 4.5 g of a dye of the formula

N »N_ ^ \\ _ C i WNN-

one, the presentation of which is based on the German Auslegeschrift 1 039 84o. This dye is made diffusion-resistant by staining with 1.5 g of 3.3 ^l -dianisidyl-4, V-diblguanld. Furthermore, the emulsion layer is not sensitized or is sensitized with an orthochromatic sensitizer. After exposure and processing, a purple image is obtained, the gradation of which is opposite to the original.

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Example 5

The procedure described in Example 2 is followed Dye seed layer but 5.5 g of a dye the - formula

the representation of which is given in French patent specification 956 693. The dye is: through staining with 2.Jg 3.3 * -Dianisidyl-4,4 ^f -dibiguanid. Made diffusion-proof. No sensitizer is added to the emulsion layer.

After exposure and processing, a good yellow image is obtained photographic properties, the gradation of which is opposite to the original.

A bleach catalyst can be added to the bleach bath for faster bleaching such as 2-hydroxy-5-aminophenazine in amounts of 3 - Io mg / l can be added.

Example 6

The procedure described in Example 3 is repeated, with the difference that instead of the colloidal silver sulfide, 20 mg of silver filter yellow are added to the dye layer. After exposure and processing, an image with similar properties as in Example 3 is obtained.
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U72741

' Example 7 . . '..

On a base made of white pigmented cellulose triacetate the following layer structure is cast:

1. a dye seed layer as indicated in Example 1.1, over which an intermediate layer of 2 x 1 gelatin solution as described in Example 2, followed by a red-sensitized emulsion layer according to Example 1.2 with about 20 g of silver halide per 1 solution.

2. an intermediate layer of 6 igexr gelatin solution,

3 a dye seed layer according to example k, an intermediate layer of 2 # gelatin solution, as well as a green-sensitized bromosilver coating with about 17 g of silver halide per liter of solution,
4. an intermediate layer of 6 # gelatin solution, 5 · a dye seed layer according to Example 5 * followed by an intermediate layer of 2 # gelatin and an unsensitized bromide silver emulsion with about 14 g of silver halide per liter of solution,
6. a protective layer of 2 # gelatin solution, also after

Example 2. ■ _t

After drying, it is exposed behind a color negative and processed in the bath sequence given in Example 2 and the composition listed there with the following tents: 1. Develop 3 minutes, alternating Io seconds immersed in the developer and switched on Io seconds dwell outside of the developer,

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2 «soak for 3 minutes

3. Color bleaching io minutes

4. Soaking for 5 minutes

5. Bleach-fix 15 minutes

6. Soak in the bottom for 20 minutes.

After drying, you get a positive reflective image in natural colors (with a gradation opposite to the original).

Example 8

The procedure is as in Example 7, but 1 mg of silver sulfide per liter of solution is added to the intermediate layers 7.2 and 7.4. After exposure and processing as described, a positive reflective image is obtained as in Example 7, but with improved color separation.

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Claims (3)

1. Color photographic multilayer material which, arranged on a layer support, contains the following layers: a dye seed layer with development skeim.en for silver salts and ^ a blue-green azo dye, on it one for red light sensitive silver halide emulsion layer, on top of that an intermediate layer, on top of that a dye seed layer, the development nuclei and a purple azo dye contains a silver halide emulsion layer sensitive to green light, an intermediate layer and, on top of it, in turn a dye seed layer, the development nuclei and a contains yellow azo dye, one sensitive to blue light Halogen silver emulsion layer and, as the outermost layer, a protective layer, characterized in that between the associated Dye seed layers and the photosensitive silver halide emulsion layers arranged an intermediate layer is. 2. Color photographic multilayer material according to claim 1, characterized in that for the production of the part color images Pairs of layers are used which are machined from a silver halide emulsion and. ”below this adjacent germinal layer with a content of an Aaofarbstofi exist. 3. Multilayer color photographic material according to claim 1, characterized in that those arranged between the pairs of gods Intermediate layers contain precipitation nuclei for silver halide. - 22 - 909804/1165 \ expensive subdivisions (Art 7 s ι Paragraph 2 No. ι sa * 3 d _M