DE1923824A1 - Process for developing and stabilizing imagewise exposed and optionally photo-developed silver halide recording materials of the internal image type - Google Patents

Description

PATENTANWÄLTE 78/25/77

DR.-ING. WOLFF, H. BARTELS, ⁸ _{mmscHsrRASSE9}

DR. BRANDES, DR.-ING. HELD phone = pu) 293297

Reg. No. 121 788

EASTMAN KODAK COMPANY, 3 * f3 State Street, Rochester, New York State, United States of America

Process for the development and stabilization of imagewise exposed and optionally photo-developed silver halide recording materials of indoor image type

As is known, it is often expedient to make the image recordings produced with the aid of copying or direct copying photographic recording materials permanent or to stabilize them if the images produced using such recording materials are to be stored for a long time without any loss of quality. It is known that print-out and direct-print photographic recording materials have a high background density when they are developed in conventional developer solutions after exposure. The increase in background density or background fogging poses a problem in particular when photo-developed, direct copying recording materials are stabilized or developed in conventional developers. In such a case, namely ^Λ bildfct usually both in the BiId-

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also in the background areas of the picture recordings created during exposure photolytiscb.es silver.

To date there have been no development or stabilization baths became known with which see both those with non-photo-developed as well as photo-processed direct copying photographic recording materials Allow images to stabilize sufficiently.

The object of the invention is therefore to provide a method for stabilizing or developing image-appropriately exposed, optionally photo-developed, silver halide recording materials of the internal image type, when carried out with both copying and direct copying photographic recording materials, stable copies can be obtained without creating an undesirable background density.

The invention was based on the knowledge that the object set can be achieved if image-appropriately exposed and optionally photo-developed silver halide recording materials of internal image type _3, optionally after treatment in a bleach bath, are treated with a surface developer which, apart from a silver halide developer bond, contains a low concentration of a silver complex binder contains *

The invention relates to a process for developing or stabilization of imagewise exposed and possibly photo-developed silver halide recording materials * - Llen of the internal image type, characterized in that the recording materials, optionally after treatment with a usual silver halide solution, with one of fibers strong silver halide solvents free development,

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brings into contact which, in addition to a customary developer compound, contains about 1 · 10 " ⁵ to 2 · XO" * ⁵ Hol or, in the case of treatment with a silver halide ^{bleach solution, 1 · 10 "^ to 4 * 10""· 5} mol of a silver complexing agent with ( a) at least one radical which is able to enter into a covalent bond with silver, and (b) at least one radical with a »bond.

The invention also relates to a developer solution for carrying out the process, which is characterized in that, in addition to a silver halide developer compound, it contains about 1 · " ⁵ to h · " * ⁵ mol of silver complexing agents per liter and practically no strong silver halide solvents.

The invention achieves that both the exposure latent images obtained after copying out photographic recording materials as well as those obtained after exposure and Photo development of direct copying photographic recording materials obtained images into permanent, stable image recordings or copies can be transferred.

The surface developers used in the process of the invention In addition to a silver halide developer compound, they contain small amounts of a selective silver complexing agent, but no or virtually no strong silver halide solvents, e.g. B «thiocyanates and / or sodium thiosulphate. The fact that low concentrations of the silver complexing agents in the developer solutions improved Development process would lead is surprising, since the same silver complexing agents in higher concentrations are unable to exert a corresponding influence on the development properties of corresponding developer solutions. Even more surprising is the fact that such developer solutions to stabilize or make permanent both

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non-photo-developed as well as photo-developed, direct copying photographic recording materials used can be.

According to an advantageous embodiment of the method of Invention can be imagewise exposed, direct copying photographic Recording materials in a one selective. surface developer containing silver complexing agents developed, then fixed and washed.

According to a further advantageous embodiment of the method of the invention, direct copying photographic images which have been exposed in accordance with the image and which have been photo-developed to form differentiated images can be used Recording materials in a surface developer containing a selective silver complexing agent developed, then fixed and washed.

According to a further advantageous embodiment of the method of the invention, direct copying photographic recording materials which have been exposed imagewise can be bleached, developed in a surface developer containing a selective silver complexing agent, fixed thereon and washed will.

According to a further advantageous embodiment of the method of the invention, photodeveloped, direct copying images can be exposed and distinguishable in an imagewise fashion photographic recording materials bleached in one containing a selective silver complexing agent Surface developer developed, fixed on and washed.

The usable in the developer solutions according to the invention, selective silver complexing agents are characterized by two distinctive residues in their molecule. .

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So once they contain at least one remainder, which is necessary for training is capable of a covalent bond with silver, for example a -S-Ag or ^ N-Ag bond, d. H. the Complexing agents contain z. B. imide residues (^ NH) or mercaptan residues (-SH) or corresponding tautomeric radicals.

Furthermore, the complexing agents contain at least one further radical which does not enter into a covalent bond with silver under the conditions occurring in photographic emulsions and photographic developer solutions, i. .H. a residue that forms so-called secondary bonds. Bonds of this type are often referred to as "π bonds ^11. Ir bonds correspond roughly to ion-dipole bonds. Such bonds cannot be regarded as completely covalent and are also weaker than usual covalent bonds (cf. for example this Book by Cotton and Wilkinson "Advance Inorganic Chemistry", 2nd edition, pages 728, 745 and 776-777) · Typical residues of this type which enter into secondary bonds and which the silver complexing agents may have are

1.) Carbon-carbon double bonds of the formula

I> C = C ^ and groups of such carbon-carbon double bonds. Such radicals or groups of radicals can be used, for example, as part of a heterocyclic ring system, e.g. B. a 2-mercaptoimidazole ring, or in an alkyl side chain, e.g. As in the case of l-allyl-2-thiourea;

2.) aromatic substituents, e.g. benzo- and phenyl derivatives e, and

3.) Groups with donor atoms with two non-bonding electron pairs, for example residues of the formulas -C-O-C-,. -p-S-C- and -S-S.

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Ϊ923

Examples of the three types of complexing agents indicated are

1) Compounds with a C = C group: 2-mercaptoimidazole:

'Ag

secondary binding through the secondary binding group of it binding.

Group as

2) Compounds with aromatic substituents 2-Benzimidazolethiol:

secondary bond

3) Connections with groups that donoratorae with two do not binding electron pairs contain:

a) -C-O-C ^ "as secondary bonding group: 5-IIethyl-2-oxazolidinthione:

CH-

, secondary bond

AgX

BAD ORSGlNAL

SAs

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b) -c-S-C- as secondary bonding group:

Thiazolidine-2-thione:

AgX

secondary bond

Say

c) -S-S- as a secondary linking group Aminophenyl disulfide:

secondary bond

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The usable in developer solutions according to the invention SiIberkomplexbildner can be further characterized in that they are in 1 liter of water to solve a temperature of about 21.1 ⁰ C in an amount of at least 10 ^"5, and preferably 10 moles, and equimolecular in aqueous solution in the presence of or excess amounts of silver ions, measured by potentiometric titration, are capable of forming a silver complex in a molar ratio of at least 1 mol of silver ion to 1 mol of complexing agent.

The silver sequestrants are used as part of the process The developer solutions used in the invention are incorporated in lower concentrations than would normally be used to prevent fogging.

In the embodiments of the method of the invention in which exposed recording materials are developed and stabilized immediately after the imagewise exposure and optionally photo development in a developer solution according to the invention, the developer solution should be less than 2 × 10 moles / liter and preferably less than 1.5 x 10 ~ ^ moles / liter contain silver complexing agent. A developer solution used in the described embodiments of the method of the invention can thus, per liter of solution, e.g. B. about 10 ~ ^ to 2 χ 10 ~ ^, preferably about 1 χ 10 " ¹ * to 1.5. ΙΟ" ³ mol of silver complexing agent.

In the embodiments of the method of the invention in which the development and stabilization of photographic Recording materials, in a developer solution after Invention preceded by bleaching in a bleach bath, is, the concentration of silver complexing agent in the developer solution is expediently about 10 "* to 4 χ 10",. preferably at about 10 to at most 2.5. 10 "^ moles per liter Solution.

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If the specified concentrations of silver complexing agent are exceeded, the density of the developed image becomes higher reduced.

According to a preferred embodiment of the method of Invention direct copying recording materials are thereby developed and stabilized by first placing them in a bleach bath and then in a silver complexing agent of the type described containing developing solution according to the invention is immersed.

Typical complexing agents suitable for carrying out the process of the invention and having the specified properties are for example:

2-mercaptothiazole; 2-mercaptobenzothiazole-j 2-mercapto-6-nitrobenzothiazole; 4-carboxymethyl-4-thiazolin-2-thione; Thiazolidine-2-thione; Imidazole; 2-benzimidazolthlol; 5-amino-2-benzimidazole thiol; 2-mercaptoimidazole; l-methyl-2-mercaptoimidazole; 2-mercaptopyrimidine; Dithiourazole; o-aminobenzenethiol; o-mereaptobenzoic acid; l-phenyl-2-mercaptotetrazole 5 l-phenyl-2-thiourea; 5-nitrobenzimidazolthiol ^ - amino-2-mercaptobenzothiazole; 2-benzoxazolthiol; 5-methy1-2-oxazolidinthione; 4-aminophenyl disulfide and l-allyl-2-thiourea.

The silver halide emulsion layers can optionally also be used of developed according to the method of the invention and stabilizable, photographic recording material

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Halogen acceptors .Ilen contain smaller amounts of WSSSBSSJESSXSS ^ h with the properties of the specified silver complexing agents. This can ζ. B, be the case with direct copying recording materials which contain halogen acceptors. In der Hegel, however, the halogen acceptor concentration which is used in view of the optimum image properties which can be achieved in the photodevelopment of direct copying recording materials is not sufficient to develop the necessary stabilizing effect in a surface developer. It follows from this that the image recordings or copies obtainable with halogen acceptors containing direct copying photographic recording materials can also be improved with the use of developing solutions according to the invention with silver complexing agents in the specified concentrations.

The bleach baths which can be used to carry out advantageous embodiments of the method of the invention can contain conventional oxidizing agents, for example those described in the journal "The Journal of Photographic Science ¹¹ , Volume 9, Selten 217-222 (1961). The oxidizing agent concentration is expediently im Within the scope of the process of the invention usable bleach baths, based on 1 liter of solution, at about 1 to about 100, preferably at about 5 to about 50 g.

The developer baths which can be used in the context of the process of the invention can contain the customary known developer compounds suitable for surface development of photographic recording materials, for example hydroquinone, Ascorbic acid, l-hydroxy-2-methylaminobenzene, catechol, Pyrogallol, l-phenyl-3-pyrazolidone, p-hydroxyphenylaralnoacetic acid, t.-Buty! hydroquinone, 4-methyl - ^ - hydroxyinethyl-1-phenyl-3-pyrazolidone and the like.

d. H. many silver complexes suitable according to the invention Formers are known halogen acceptors.

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As already mentioned, the Developer solutions usable in the invention no or practically no strong silver halide solvents or fixers, such as water-soluble thiocyanates and thiosulfates, e.g. B. potassium thiocyanate and sodium thiouslfate, because by the presence of such compounds that in view on the balance required for the good results obtainable in practicing the process of the invention would be disturbed.

The silver halide recording materials which can be developed and stabilized by the process of the invention can be internally sensitive to electromagnetic radiation, ie to light, X-rays and electrons, in the usual manner. Silver halides suitable for producing such recording materials are, for example, customary silver bromide, silver bromoiodide, silver chlorobromide and silver chlorobromoiodide of intrinsic sensitivity. Internally sensitive silver halides which are preferably used to produce the silver halide emulsion layers of such photographic recording materials are those silver halides which predominantly consist of silver bromide. The photographic recording materials which can be developed and stabilized by the process of the invention preferably have emulsion layers whose silver halides have a greater internal sensitivity than their surface sensitivity. Enulsions of this type are described, for example, in U.S. Patents 2,592,250, 3,206,316, 3,206,313, 3,271,157 and 3,287,137 and Glafkides' book "Photographic Chemistry ¹¹ , Volume 1, Selten 31-32, published by Fountain Press , London, and the journal "Photographic Science and Engineering ¹¹ , Volume 5, Kr. 2, March / April 196I, pages 104-108.

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Characteristic of the so-called ^M inner image emulsion layers of photographic recording materials which can be developed and stabilized according to the method of the invention are silver halide crystals, the main sensitivity of which lies in the interior of the crystal on a transparent support, exposure of the recording material obtained using an intensity scale with a predetermined exposure time between 1 χ 10 "and 1 second, bleaching of the exposed recording material for 5 minutes in a 0.3% potassium ferricyanide solution at a temperature of about 18.3 ^° C. and Developing the bleached recording material in an "internal grain developer" of the following composition:

N-methyl-p-aminophenol sulfate 2.0 g

Sodium sulfite, dried 90.0 g

Hydroquinone 8.0 g

Sodium carbonate, monohydrate 52 _a S g

Potassium bromide 5.0 g

Sodium thiosulfate 10.0 g

made up to 1 liter with water

as respective emulsions Langbei 6 minutes after applying a respective test quantity in a film base and the appropriate exposure greater sensitivity, as measured by conventional photographic processes at a density of 0.1 above fog having a temperature of 20 ⁰ C in a "surface developer" of the following composition:

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A3

N-methyl-p-aminophenol sulfate 0.31 g

Sodium sulfite, dried 39.6 g hydroquinone 6.0 g

Sodium carbonate, dried 18.7 g potassium bromide 0.86 g

Citric acid 0.68 g

Potassium metabisulphite 1.5 g made up to 1 liter with water

were developed.

Containing the developed according to the method of the invention and stabilizable directly copied photographic recording materials halogen acceptors, so may be the conventionally known halogen acceptors, for example, nitrogen-containing halogen acceptors of known type from the US Patents 3,287,137 and 3 271,357th

That for the preparation of according to the method of the invention developable and stabilizable photographic recording materials preferably used silver halide emulsions are expediently after their precipitation, but before application, based on the silver halide, about 0.1 to about 50, preferably about 1 to about 10 MoI-Ji water-soluble Halide added.

As already mentioned, the method of the invention can also for developing and stabilizing other silver halide recording materials, for example from developable Silver halide recording materials are used, when appropriate, their image properties maintain or improve.

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/ ft

In the production of silver halide demulsions for after developable and stabilizable by the process of the invention Photographic recording materials can be used as supports or binders the most varied of commonly used colloids, for example the customary known hydrophilic colloids, such as gelatin, colloidal albumin, polysaccharides, Cellulose derivatives, synthetic resins such as polyvinyl compounds, Polyvinyl alcohol derivatives and AcrylamidpolyraeFisate, used will. Apart from the listed hydrophilic colloids, hydrophobic colloids, a. B »dispersed polyvinyl verb indications, especially those that increase the dimensional stability of the photographic recording materials, be used. Suitable compounds of this type are, for example, water-insoluble poly (alkyl acrylates) and Poly (alky! Methacrylate), poly (acrylic acid), poly (sulfoalkyl acrylate) and poly (sulfoalky! methacrylate).

The recording materials may be conventionally known ones Have layer supports, for example made of glass, metal, paper, papers coated with polyolefins, made of foils Cellulose nitrate, cellulose acetate, polystyrene, polyester, e.g. B. polyethylene terephthalate, and heat-resistant films made of polymers, z. B. high temperature polyesters, polyimides and polycarbonates.

The essential components of is the framework of the process of Invention developers and stabilizers used, namely the developer compounds, Silberkoraplexfoildner and optionally Bleach, can be in diluted, concentrated form or powder form either mixed with each other or individually packed. The components are expedient individually packaged and by dissolving in aqueous, alkaline solutions or water into a ready-to-use form convicted.

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The following examples are intended to illustrate the invention in more detail.

example 1

Several strips of one using a direct copy Silver halide emulsion of that in Example Id of the United States patent 3,287,136 of the type described The recording material was placed in a sensitometer -2}

Exposed to high intensity xenon light through a step wedge for 10 seconds. This was followed by the exposed strips photodeveloped by exposure to fluorescent for 30 seconds Daylight with an illuminance of around 2690 lux were exposed. There were negatives with a density distinction of about 0.4 obtained.

One of the photo-developed strips was for 60 seconds in a developer A of the following composition:

Water 800 ml

N-methyl-p-aminophenol sulfate 6g

Sodium isoascorbate 40 g

Potassium bromide Ig

Potassium metaborate 40 g

4-methyl-1-phenyl-3-pyrazolidone Ig

made up to 1 liter with water

developed, then stopped in acetic acid for 10 seconds, Fixed in a sodium thiosulfate solution for 2 minutes and then washed in running water for 5 minutes.

A second strip was developed in a similar manner. However, this time 0.1 g of 1-phenyl-5-mercaptotetrazole per liter was added to the developer added.

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The results obtained are shown in the table below :

Background-

low image density

Developer A- 0.48 0.16 '

Developer A +

l-phenyl-5-mercaptotetrazole 0.67 1.01

By adding l-phenyl-5-mercaptotetrazole to the developer solution image reversal was prevented and the development of the high-intensity exposed image areas was promoted, whereby a negative was obtained which corresponded to the photo-developed image normally obtained with a direct copying recording material.

Corresponding results were obtained when less than 150 mg of 2-mercaptoiniidazole, dithiourazole, 1-allyl-2-thiourea, ¹ i-carboxymethyl- ⁱ f-thiazolidine-2-thione or o-mercaptobenzoic acid were added to the developer solution.

Example 2

A photographic recording material was prepared using the direct copying silver halide emulsion described in Example la of Belgian Patent 689,515. Several strips of the recording material obtained were exposed in a sensitometer for 10 seconds to high-intensity xenon light through a step wedge. After exposure, the individual strips were photo-developed by exposing them to fluorescent light with an illuminance of about 5 ¹ K) lux for 2 minutes. The density values of the image areas and the background areas are given in Table I below.

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One of the photo developed strips was used for comparison For 60 seconds in a developer B of the following composition:

N-methyl-p-aminophenol sulfate 4.5 g / liter

Hydroquinone 9.0 g / liter

Sodium sulfite 50.0 g / liter

Sodium carbonate 80.0 g / liter

Potassium bromide 2.0 g / liter

developed, then stopped for 10 seconds, then fixed for 5 minutes and washed for 5 minutes. the The image density values obtained in this way are also given in Table I »

Further corresponding non-photo-developed and photo-developed strips were in a corresponding developer solution B, which each contained the complexing agent specified in Table I in the concentration also specified, developed. The image density values obtained are also given in Table I.

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T A L B E L L E I 1.24 after photo
development
Behind
basic image
dense density 0.68 Ent
wick
ler Silver Complex * -
sculptor Conc
tration
in g / 1 1.18 0.38 0.49 - - without photo
development
Behind
basic image
density density 0.56 0.85 B. - 1.21 O, 52 B. 2-mercapto-
imidazole 0.1 0.14 1.21 0.91 B. 2-mercapto-
iraidazol 0.01 0.12 1.23
1.22 0.64 0.64 B. 2-thiouracil 0.1 1.24
1.22 0.58 0.82
0.53 B. 2-thiouracil 0.01 0.14 1.22
1.24 0.62
0.49 0.84
0.49 B. 2.5 dl mercapto
1,2,4-thia-
dlazol 0.1
0.01 0.15 1.22
1.23 0 _s 60
0.48 0.80
O ₉ 53 B. Dithiourazole 0.1
0.01 0.20
0.18 1.24
1.24 0.62
0.52 0.73
0.42 B. 2,5 dithio
diurea 0.1
0.01 Q _s l6
0.19 0.55
0.46 0.83
0.50 B. 2-thio red
acid O ₉ I.
0.01 0.16
0.16 0.60
0.55 B. 2,6-dimercapto-
purine 0.1
0.01 0.16
0.22 0.19
0.18

The results compiled in the table show that with both photo-developed and non-photo-developed, Direct copying recording materials have good image density values when the recording materials are developed with such surface developers, the silver complexing agents are obtained contained in low concentrations.

Similar results were obtained when instead of the 2-mercaptolmidazole in the developing solution Baidazol, 1-allyl-2-thiourea or o-hercaptobenzoic acid was used.

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Example 3

Is the development and stabilization done photographic Recording material in the context of the method of the invention In addition, in a bleach bath, this is done before the recording material is put into the silver complexing agent concerned containing development solutions.

A photographic recording material with a direct copying Silver halide emulsion layer of the in Example Id U.S. Patent 3,287,136

-ή
a Sensitameter for 10 seconds with a high intensity xenon lamp, image-orientated to the point. The exposed recording material was then photo-developed by exposing it to fluorescent daylight with an illuminance of about 2690 lux for 2 minutes.

A correspondingly exposed recording material was used as a reference point In a developer A for 2 minutes. Composition:

Mass 800 ml

N-methyl-p-aminophenol sulfate 6 g

Sodium isoascorbate ^{1 IOg}

Potassium bromide Ig

Kallurametaborate ¹ JO g

$ -Methyl ~ 1-phenyl-3-pyrazölidone Ig

made up to 1 liter with water

developed, then fixed for 5 minutes and then washed with running mass.

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Another corresponding recording material was for 2 minutes in a developer C of the following composition:

Water 800 ml N-methyl-p-aminophenol sulfate 6g

Sodium isoascorbate 40 g potassium bromide Ig

Alkali (Kodak Balanced Alkali) 10 g ^ -Methyi-l-phenyl - ^ - pyrazolidone 1 g

1-phenyl-5-mercaptotetrazole 0.1 g

made up to 1 liter with water

Developer pH 10.0

developed, then fixed for 5 minutes and then washed with running water.

Other corresponding, manufactured in the manner described and exposed recording materials were initially for 2 minutes in an oxidizing bleaching bath a of the composition:

Potassium dichromate 7.5 g

concentrated sulfuric acid 5.0 ml

made up to 1 liter with water

bleached and then in the same way as the comparison material further treated.

When bleaching baths and developer solutions are combined with the relevant silver complexing agents, images are also created lower minimum density and better image discrimination than when using only developer solutions with the relevant Silver complexing agents or when using Bleach baths in combination with common surface developers. This can be seen from the table II below compiled results:

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TABEL II I. 0.55 0.48 Pale 0.51 0.88 bath Reflection density of the 0.47 0.30 - Developer background image 0.43 0.87 - A. A. G A. A. Example ^] fi

Photograph! See recording materials with direct copying Silver halide emulsion layers of the Belgian in Example 4 The type described in U.S. Pat. No. 705,036 were disclosed in

-4
exposed for 10 seconds through a step wedge with high-intensity xenon light using a sensitometer. After exposure, the recording materials were photo-developed by exposing them to fluorescent daylight with an illuminance of about 540 lux for 5 minutes.

One of the photo-developed recording materials became then in a developer for 1 minute for comparison D of the following composition:

N-methyl p-aminophenol sulfate Sodium sulfite, hydroquinone, sodium carbonate, potassium bromide, made up with water

1.5 g 50.0 g

9.0 g 80.0 g

2.0 g 1 liter

developed, then fixed for 30 seconds and then washed with running water.

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Έΐη became another photo-developed recording material For 1 minute in a developer E of the following composition:

N-methyl-p-aminophenol sulfate 4.5 g

Sodium sulfite 50.0 g hydroquinone 9> 0 g

Sodium carbonate 80 »0 g potassium bromide 2.0 g

2-mercaptoimidazole 0.1 g

made up to 1 liter with water

developed and then treated further in the manner described.

Another correspondingly photo-developed recording material was first for 1 minute in a bleach bath b with the following composition:

Potassium dichromate 20 g

concentrated sulfuric acid 4 ml

made up to 1 liter with water

bleached and then in the same way as the comparison material further treated «The density values obtained during the examination of the individual recording materials are given in the following table III:

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T9238 24

TABLE III

developer Permeable jkeit »density of Bleach bath D.
E.
D.
E. Background Is picture b
b 0.72
0.65
0.12
0.25 1.12
1.22
0.22
0.66

When using the usual surface developer, a Preserved negative with high background density. Against it was when using the bleach bath and the one silver complexing agent Of the type described, developing solution containing an image with a greatly reduced background while the same Image difference received. This is the case when using the bleach bath and the developer solution containing the silver complexing agent The image obtained was far more visible to the eye because the Image density was far greater than the background density.

Similar results were obtained when in developer E instead of the 2-mercaptoimidazole as a silver complexing agent l-allyl-2-thiourea, imidazole, dithiourazole or 1-phenyl-2-thiourea was used.

Example 5

For comparison purposes, the method in Example la of the Belgian patent 689 515 described direct copying Emulsion is a photographic recording material manufactured (material I).

Starting from the same emulsion, which, however, per mole Silver 15 g of 2-mercaptoimidazole was incorporated

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Vt-

another photographic recording material (material II) produced. The two photographic recordings obtained, Drawing materials were scanned in a Sensltometer for 10 seconds by means of a high-intensity xenon lamp with a 0 exposed up to 3.0 neutral density step wedge. The (latent) images thus obtained were photo-developed by 30 Seconds were exposed to fluorescent ^ daylight with an illuminance of about 26 * 10 lux.

Samples of the two photo-developed recording materials were initially for 30 seconds at a temperature of about 21.1 ° C in a bleach bath c of the following composition:

Potassium dichromate 20 g

concentrated sulfuric acid 4 g

made up to 1 liter with water

bleached, then for 60 seconds in a developer F of the following composition:

N-methy1-p-aminophenol sulfate 3.1 g Hydroquinone 12.0 g Sodium sulfite 45, floor sodium 80.0 g Potassium bromide 1.9 g old water topped up 1 liter

developed, then for 60 seconds in a fixer with the following composition:

Sodium thiosulfate 240 g Sodium sulfite 15.0 g

made up to 1 liter with water

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fixed and held for 2 minutes with running water washed·

Further samples of the photo-developed recording materials were treated appropriately »This time, however Instead of the developer F, a corresponding developer Q with an additional, per liter of solution, 0.075 g of 2-mercaptoialdaiol used. ;

The photographer Is ehe η developed during the investigation The density values obtained for the suspension materials are given in the following Table IV:.

TABLE IV

Developer F lter Image

View back

basic density

material density ______ Material I 0.28 0.36 Material I.

Material II 0.34 0.64 Material II

AD

- ■ ι mw + m ι

0.02 0.30

, ltwlcklar 0 background oil density

0.30 0.57 0.2T

0.38 0.76 0.38

The use of a developer solution containing the silver complexing agent was compared to the use of a corresponding developer solution without silver coraplex former found an improvement in image sharpness. Furthermore leads to the simultaneous presence of a corresponding or the same silver complexing agent both in the developer solution as well as in the emulsion layer of the photographic material to be developed for a further improvement the sharpness of the image.

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BATH ORIGINAL

Claims (8)

PATENT CLAIMS 1. Process for developing or stabilizing image-properly exposed and optionally photo-developed silver halide recording materials of the internal image type, characterized in that the recording is made of material, possibly after treatment of a conventional silver halide solution, old of a strong silver halide! Oeunaaltteln free developer solution brings into contact, which on a conventional developer compound about 1 · ^{10 "5} to 2 * 10" ³ mol or in the case of treatment with a silver halide lead solution 1 * 10 " ⁵ to 4 · 10" ³ mol of a silver complexing agent old U) At least one "remainder that old silver is able to form a co-talented bond, and (b) at least one remainder of a" bond. 2. The method according to claim 1, characterized in that one starts from a direct copying photographic material containing a halogen acceptor. 3 * method according to claims 1 and 2, characterized in that that aa silver halide recording seeds are assumed, the silver halide crystals of which are predominantly sensitive to internal grains. 4. Process according to Claims 1 to 3 »characterized in that that the recording materials are developed with a developer solution, the solution per liter, about 10 "to 1.5 x Contains 10 "- * moles of silver sequestrant. 5. Process according to Claims 1 to 4, characterized in that developer solutions are used which, as a silver complexing agent, are l-allyl-2-thiourea, 2-mercaptoimidazole, dithiourazole and / or l-phenyl-S-mercaptotetrazole. ,. BATH ORIGINAL 909850/0759 6. Process according to Claims 1 to 5, characterized in that the recording materials are in prior development a potassium dichromate bleach bath. 7. Process according to Claims 1 to 6, characterized in that the recording materials are treated with a developer solution Developed as super-complexing compounds contains, whose to form covalent bonds with Silver capable residues of mercaptan, imide or tautomeric residues thereof and their to form a w-bond or • v ** **. * · residues capable of secondary bonding consist of -C-O-C-, -C-S-C- or -S-S residues. 8. Aqueous developer solution for carrying out the process according to claims 1 to 7 »characterized in that it contains about 1 χ ΙΟ" * to h χ 10 "'moles of silver complexing agents and practically no strong silver halide solvents in addition to a silver halide developer compound per liter of solution. 9 * Entwicklerlöeung according to claim 8, characterized in that the silver complexing agent in the presence of excess silver ions, as measured by titration potentlometrische, door formation of silver complexes in a molar ratio of at least 1 mol of silver su j} Mo1 silver complexing capable Video-. ' BAD ORiG- ¹ TIMES 909850/0759