DE1547986C - Process for the production of photographic images, in particular by the silver salt diffusion process - Google Patents

Description

The invention relates to processes for the production of photographic images, particularly according to the silver salt diffusion method in which a light-sensitive silver halide emulsion layer is imagewise exposed and treated with an aqueous-alkaline developer mixture containing a Silver halide developer, a complex-forming silver halide solvent and as an additional complex-forming compound a mercapto compound with the structural elements

SH
-N = CO-

SH

-N = CS
SH

which is able to form a compound less soluble than silver halide with silver ions, or a nitrobenzimidazole derivative, a nitroindazole derivative, a benzotriazole, an 8-azaxanthin, a 6-benzylaminopurine, a 2,6-dimercaptopurine, a 2,2'-dimercaptodiethyl sulfide or a thiourea, and in which if necessary, a transfer to a separate image receiving material takes place.

Most of all silver halide photographic processes use the unexposed one Silver halide dissolved and the exposed emulsion layer simultaneously with or after development removed. The preferred resolution of the unexposed silver halide substantially simultaneously with that Development of the latent image is the basis of a number of photographic processes, in particular the Silver Salt Diffusion Transfer Process (U.S. Patent 2,543,181; A New One-Step Photographic Process "by Edwin H. Land, Journal of the Optical Society of America, Vol. 37, pp. 61 to 77, February 1947; "One - Step Photographic" by Edwin H. L a η d, The Photographic Journal, January, 1950, pp. 7 to 15). The dissolved silver complex is thereby transferred to another layer and there the silver precipitated and thus a positive silver transfer image built up.

From the USA patents 3,155,506, 3,155,507, 3155 514 to 3155 519, a so-called "photo resolution method" is known in which the light-sensitive silver halide emulsion layer with various compounds such as mercapto compounds, treated before exposure. The emulsion treated in this way is exposed to light and without use a developer for the silver halide, with a solvent for the silver halide in Brought into contact so that the exposed silver halide is dissolved from the image areas. The unexposed silver halide remains undissolved in the emulsion layer, is exposed and therein a silver image built up by reduction. A very large one is required for this known method Exposure, namely exposure times that are essential are larger than they can be carried by cameras. So it is this photographic process a very insensitive process.

US Pat. No. 2,699,393 discloses mercaptotetrazoles in the context of silver salt diffusion transfer processes to be used as a toner, namely in the developer mass in low concentration.

The object of the process according to the invention is a fast-working, photographic recording process indicate that it allows positive or negative images with a, good image density and produce excellent contrast and in which the recording materials to be used a have such a high photographic sensitivity that an application of the method according to the invention is possible with conventional cameras.

The object of the invention is based on a process for the production of photographic Images, especially by the silver salt diffusion process, in which a photosensitive silver halide emulsion layer imagewise exposed and treated with an aqueous-alkaline developer mixture is containing

a) a silver halide developer substance,

b) a complexing silver halide solvent and

c) as an additional, complex-forming compound, a mercapto compound with the structural elements

or

or

SH

-N = C-N-

SH

-N = C-O-SH

-N = C-S-

which forms a compound less soluble than silver halide with silver ions, or a nitrobenzimidazole derivative, a nitroindazole derivative, a benzotriazole, an 8-azaxanthin 6-benzylaminopurine, a 2,6-dimercaptopurine, a 2-dimercaptodiethyl sulfide or a thiourea,

and in which, if necessary, a transfer to a separate image receiving material takes place.

The method according to the invention is now characterized in that

d) by an imagewise exposure in which the silver halide is exposed just enough that it is starting to become evolvable,

e) by using the complex-forming compound which acts as a dissolution accelerator (c) in a concentration of at least 1 g / l of the developer mixture and

f) a preferred resolution of the silver halide by observing a certain development time is brought about in those exposed parts of the image in which the development is already taking place has started, while unexposed silver halide has not yet reached dissolution.

According to one embodiment of the invention, 1-phenyl-5-mercaptotetrazole is used as an additional, complex-forming compound used. The additional, complex-forming compound "c" acts in the case of the one according to the invention Process as a dissolution accelerator.

If the process according to the invention is a diffusion transfer process, the image silver can be precipitated from the complex by drying the image receiving layer or a silver precipitating agent can be provided in this layer. However, the treatment mixture can also contain a silver precipitating agent.
A variant of this process consists in providing a silver-precipitating agent in the emulsion layer so that the silver halide complex formed therein is reduced to a negative silver image on the spot.

A developed silver halide emulsion layer is obtained in the process of the present invention with the imagewise distributed diffusible complex, which absorb UV radiation able. This layer can now be used for making a positive image by adding this Layer as a master for a UV exposure of a conventional photographic recording material serves.

Another embodiment of the erfindungsge- \ MAESSEN method is that you removed by diffusion, and this subjects the Silberhalogenidkomplex dissolved from the emulsion layer without prior fixation of a total exposure. In this way a positive silver image is built up in the emulsion layer.

In a further embodiment of the method according to the invention, the dissolved silver halide complex becomes transferred from the emulsion layer into an image receiving layer and in this by precipitation of the complex built up a negative silver image.

Sodium or potassium thiosulphate is preferably used as the solvent for the silver halide. It was found that the rate of development and dissolution of the silver halide grain is adjustable in the process according to the invention, so that developable silver halide in an exposed Grain is preferentially dissolved in the developer mixture.

The recording material used according to the invention is conventional silver halo genid emulsions, which can be used for normal, but often * significantly lower exposure. The The basic principle of the method according to the invention is based on the finding that when used a dissolution accelerator in a certain minimum concentration and compliance with a certain ; Development time to develop the dissolution of the! wrap beginning silver halide grain faster occurs as of non-evolving. Conventional silver halide emulsions can be dissolved in this way diverse, new and extraordinarily useful ways, because you can change the exposure and / or working conditions either a negative or positive image with regard to the submission or, even images with negative and positive parts of the image. This also applies in particular for the diffusion transfer process.

In the process of the invention, the preferred dissolution of silver halide occurs in or out exposed grain of the silver halide emulsion layer, the degree of dissolution of a developing Grain depends on the exposure. The invention achieves that depending on the applied Exposure and processing conditions with one and the same recording material and with one and the same developer mixture positive or negative images in the emulsion layer and positive or negative transfer images can be obtained. Another advantage is that Fixed, negative transfer images of high density and high contrast, even from such thin silver halide emulsion layers can be obtained that with normal processing only images with relatively moderate Density and poor contrast. The inventive method thus allows a better utilization of the sensitivity of the recording material.

In the process according to the invention, customary silver halide emulsions are used and a latent image is built up in these in the usual way by exposure; serve for further processing common silver halide developers, common alkalis, silver halide solvents. Essential to the invention however, the developability and solubility of a silver halide grain must be adjusted so that given exposure, the exposed silver halide grain, which is just beginning to develop, much faster or becomes more resolvable as unexposed silver halide. If the exposure exceeds the value which is necessary for the onset of the development of the grain, a further development of the takes place Grain to silver, making it insoluble. Given the exposure is an unexposed one and therefore undevelopable grain insoluble in the developer within the development time; a fully developed one Grain is insoluble because it is only silver, and a partially developed grain is partially soluble. at With conventional photographic systems nothing can be achieved if one is sufficient for development exposed grain is exposed via the minimum exposure required for this. In contrast to this, in the method according to the invention, an exposure above the minimum value appears to be the speed to change from development and dissolution, the silver halide exposed in this way is faster developable or has several developable nuclei in the grain.

The effectiveness of the method according to the invention should be based on the following principle: In the Developer composition is unexposed and therefore undevelopable silver halide grain completely insoluble; on the other hand a grain that has been exposed to light and has started to develop is readily soluble. From this it follows the following:

a) unexposed silver halide grain is not dissolved and is therefore not transferable;

b) excessive exposure leads to complete development and consequently no transfer;

c) It would be expected that the unexposed one would also be removed by prolonged exposure to the developer composition The silver halide grain dissolves, so that the result of a transfer is dense transfer images would be;

d) Correct exposure leads only to the beginning or partial development, and this correctly exposed silver halide grain is preferentially dissolved.

In summary, it can be seen that the appropriate exposure is preferred for a common subject Dissolvability of the exposed silver halide grain leads; in the case of a diffusion transfer process

a negative transmission image is built up. It follows that one by the invention Method can obtain negative and positive transfer images, with the highest density in the positive Image is obtained with approximately the same exposure as the highest density in the negative image receives.

The unexposed grain is not dissolved because its dissolution rate in the developer composition is too low for a noticeable resolution within the given time. On the exposed silver halide grain the development begins. The proportion of insoluble, developed silver increases with the from Amount of light absorbed by the grain. Up to the turning point of the relative speeds of development and dissolvability, silver formation by development does not increase as rapidly as dissolution and does Diffusion of the dissolved silver halide. However, there is so high an exposure that the development speed becomes large enough to hold essentially all of the amount in the highly exposed grain formed soluble complex of silver halide in the same place to reduce to silver, thereby not reducing it becomes transferable to another location. It is believed that these high exposure values lead to a Nucleation proportional to the exposure result and these nuclei remove the dissolved silver halide from the "Pull off" the grain and lead to a silver precipitation immediately on the spot. This results in, that the amount of silver halide which can be dissolved and transferred from an exposed grain is shown in a diagram can be plotted against the exposure value and a characteristic curve for each grain receives.

For a given exposure value, there are some or more groups of silver halide grains in the emulsion layer similar grain size and / or sensitivity that are just beginning to develop, the type of transfer image is an indication of a mixture of such groups. It should be pointed out that the type of image, obtained by the method according to the invention, by the one supplied to the grain Amount of light is determined. In contrast, in conventional photography, the type of image is dependent on the grain size distribution; a high-contrast image is only obtained using conventional methods, when the emulsion has a uniform grain size. In the method according to the invention the two mechanisms that determine the type of image can overlap.

This fact enables the possible types of transfer images obtained according to the invention can be expanded by mixing grain groups of a certain sensitivity. Each additional grain group The area for the negative image type becomes less sensitive before reversing to the positive image type extend. For this extended area of the negative image type, however, the relative speeds should the dissolvability and developability for groups of grains of different size or sensitivity be the same as possible. Larger emulsions with grain groups of different sensitivity are obtained by mixing sensitized and unsensitized grains of the same size.

In the method according to the invention, the finest grain is exposed and developed last, on the other hand the coarsest grain can be developed and partially dissolved by exposure the earliest. With usual However, in positive silver transfer processes, the finest grain is dissolved first. Has a grain with him Once a process according to the invention has begun to develop, it either becomes entirely silver in situ reduced or resolved.

According to the method according to the invention, depending on the exposure, negative or Create positive images or images that consist of negative and positive image parts. It is important, to point out that, according to the method according to the invention, positive images during transfer arise in a completely different way than with conventional positive silver transfer processes. There it will Positive image made up of the unexposed silver halide, because it is developed through the exposure Silver can no longer be dissolved, whereas after the method according to the invention the transferred Silver was made transferable through exposure.

In any silver halide emulsion, with any increasing exposure, there is always a number of silver halide grains which receive a sufficient amount of light to cause their size and / or sensitization to become developable with an appropriate developer. One plots in a diagram the number of grains that pass through each step to increase the exposure Can be developed against the exposure, so show silver halide emulsions, which are suitable for cameras suitable, a generally bell-shaped distribution curve of the grain sensitivity. This curve shape results from the fact that at the lowest exposure a small or minimal number of grains, namely the most sensitive, sufficiently exposed and thus developable; with increasing amount of light takes the number of developable grains up to a maximum corresponding to the medium sensitivity to; thereafter, every further increase in the amount of light becomes fewer and fewer grains Make it developable until a minimum is reached again for the less sensitive grains.

To produce a negative transfer image according to the method according to the invention, an exposure range is applied, the lowest value of which in some grains and the uppermost value in a maximum number of grains causes the beginning development. For a positive image according to the invention one works in an exposure range, the lowest value of which is the maximum Makes the number of grains developable. The positive transfer image obtained according to the invention receives its maximum density of not all grains of the silver halide emulsion (as in conventional silver transfer processes), but from a grain fraction between the high grain number of medium sensitivity and the low number of grains is the least sensitive. The decrease in image density with increasing Exposure in the positive process of the invention is attributable to two factors: 1. Development of one increasing grain number to silver in place and 2. decreasing the grain number, which with increasing Exposure becomes developable.

In other words, the process according to the invention can be used with the same developer composition receive either a negative or a positive transfer image, depending on the distribution of the grains that begin to develop. For every grain there is a critical exposure, that is a

usable but reasonably small exposure area at which some of this grain is dissolvable and thus becomes transferrable. At a given exposure, only the developing grains contribute to the image density of the transfer image; hence it results the image density of a transfer image from the distribution curve, d. H. the height of the distribution curve mentioned. The image density is therefore a function of the total number of grains for a given exposure of a given size and / or sensitivity. In the method according to the invention can therefore change the shape of the blackening curve of a transfer image by changing the number of Silver halide grains of a certain size and sensitivity.

It is of particular importance that the dissolved silver halide in the process according to the invention does not have to be reduced to silver. The new, soluble complexes of exposed silver halide are quite stable to reduction, even with respect to silver halide developers and even in the presence of alkalis; however, they can be decorated with a silver * Reduce falling material to silver, as is customary in the transfer process.

The terms "latent image", "negative image" and "positive image" are used here in their usual meanings second hand. If a silver halide emulsion layer is exposed to actinic light through a negative, the result is a positive. By precipitation of the transferred, soluble silver halide complex, a positive silver image is obtained.

The silver halide developing agent used in the present invention can be any conventionally be used, such as hydroquinone, 4-N-methylaminophenol (Metol), ascorbic acid, iso-A & corbic acid, 2,6-dimethyl-4-aminophenol, toluohydroquinone, 2,6-dimethyl-hydroquinone, 2-methyl-4-amino-6-methoxyphenol, 2,6-dimethoxy-4-aminophenol, 2,5 - dimethylhydroquinone, 2,4,6 - triaminophenol, 2,4-diaminophenol (amidol), N, N-diethylhydroxylamine, 4,6-diamino-o-cresol.

The developer mixture used according to the invention contains a silver halide solvent such as ν it is usually with positive silver transfer- ■ · driving is used, e.g. B. sodium thiosulfate, potassium thiosulfate, barbituric acid or uracil, which are associated with the unexposed silver halide can form a diffusible complex, or in the usual way Alkalis such as sodium hydroxide, potassium hydroxide or diethylamine.

The dissolution accelerator in the context of the invention is a complex-forming compound that together with a silver halide solvent, the preferred resolution of the exposed silver halide causes as soon as at least minimal exposure has taken place, making this exposed grain developable will. The exact mechanism of the reaction is not yet known. There are a multitude of complexing agents Compounds effective as dissolution accelerators. When used in conventional wet ; developing process many common properties. However, all of these properties are for the dissolution accelerator not essential, so he does not have to own it. Nonetheless, the presence may be one or more of these properties can be used for the selection of the dissolution accelerator : the. It is essential that the complexing agent form a salt or complex with silver ions capable of which, compared to silver halide, is less water-soluble. Such compounds contain the grouping

SH

-N = C-N-ίο SH

-N = C-O-

SH

-N = C-S-

or

(or their tautomeric forms). Most of these compounds work in the appropriate concentration as development inhibitors and / or antifoggants, a number of them have heretofore been used as toners has been applied to positive silver diffusion transfer images. In general, however, they will according to the invention to accelerate the dissolution in greater concentrations than for antifoggants, Toner, etc. used. To determine whether a substance is intended as a dissolution accelerator of the invention, they can be added to the developer in a diffusion process using a silver halide solvent, preferably an alkali thiosulfate. A positive silver transfer image is obtained with normal exposure. Is a, dissolution accelerator present according to the invention, it is found that if you increase its concentration comes to a value at which the transfer of unexposed silver halide is essentially canceled, but the negative development is not prevented. At this value, the concentration of the silver halide solvent and the development time increased until a negative or a silver transfer image consisting of negative and positive image parts is obtained. If you have a Receiving a transfer image consisting of negative and positive image parts results in lower exposure to a negative silver transfer image.

One consisting of negative and positive parts of the picture Transfer image comes about when the subject or the original is both very bright as well as very dark areas and thus there are two very extreme exposure areas. In which The method according to the invention results in approximately the same exposure value in this case in the highest density both the positive and negative parts of the image.

Although you can use as a dissolution accelerator according to the invention compounds which Inhibit development at concentrations much greater than those of development inhibitors in conventional photographic systems, the silicon superhalide grain remains viable and generally possesses even higher sensitivity, though the speed of development may decrease.

The complex-forming compound used in the process according to the invention is used in the Phototechnology - as mentioned - used in small quantities for other purposes, e.g. B. l-phenyl-5-mercaptotetrazole as a toner in an amount of 0.01 to lg / 1-

109 533/302

Examples of the dissolution accelerators used according to the invention are:

N-

Il
N

-N

Il

C-SH

N
Ί

l-phenyl-5-mercaptotetrazole

N N

Il Il -.

N C-SNa

Sodium-1-phenyl-1H-tetrazole-5-mercaptan

N N

l-naphthyl-5-mercaptotetrazole

4-ethyl-2-mercaptooxazoline

O ₇ N

HCl

Λ /

6-nitro-2- (2'-oxacyclohexano) benzimidazole hydrochloride

.N

HC
HC

C-SH

Il

H -HCl

2-mercapto-4-methylpyrimidine hydrochloride

y \

H-C N

HO —C

C-SH

2-mercapto-6-azauracil CH ₃

H / ~ 1 / -Ί XT 3 ^ _y V- / IN

C-SH

H ₂ -C

CH,

4,4-dimethyl-2-mercaptothiazoline OH

/ \ H-C N

H (~ \ S ~ * / ~ i Ct-J

4-Hydroxy-2-mercapto-6-methyl-pyrimidine OH C

/ V

H ₃ C - CN

H ₃ C-C C-SH

N 5,6-dimethyl-4-hydroxy-2-mercapto-pyrimidine

OH

/ V

C N

<f V-C C-SH

4-hydroxyl-2-mercapto-6-phenyl-pyrimidine CH ₃

/ \ H-C N -HCl

Il I

11th

4,6-dimethyl-2-mercaptopyrimidine hydrochloride

N C-SH

S-Mercapto-S-thia-l ^^ -a-triazacyclopent (a) -inden

OH

N 8 azaxanthin

/ V \

O ₂ NC

5-nitroindazole

H-C C-SH

CH ₃

2-mercapto-1-methyl-imidazole

. N

3-mercapto-4-phenyl-5-methyl-1,2,4-triazole

N N

I I

TJC Z """ ¹ f ~ * CtJ

ΓΙΟ V / Ks Oil

IO

30th

35

40

45

55

60

12th

2,5-dimercapto-1,3,4-thiadiazole

HS - CH ₂ - CH ₂ S CH ₂ CH ₂ SH 2,2'-dimercapto diethyl sulfide

Il

H ₂ N - C - NH ₂ thiourea

1-phenyl-5-benzoyl mercaptotetrazole H

SH

, N

^ N

2,6-dimercaptopurine H.

H ₃ C - C

4-methyl-2-mercapto-thiazoline

N -N

C C-SH

2-mercapto-5-furyl-1,3,4-oxadiazole

N
N

N
Benzotriazole

C H

6-nitroindazole
O

C-SH

2-mercaptobenzoxazole

C-SH

2-mercaptobenzothiazole

Will be a conventionally exposed silver halide emulsion, preferably with a higher exposure index than otherwise developed by the process of the invention, the silver halide dissolves very quickly in the exposed and developable areas, but only very quickly in the unexposed areas slow. The soluble complex formed precipitates silver in the presence of a silver precipitating agent, in other words, that which is complexly dissolved in the exposed areas of the silver halide emulsion Silver halide may be precipitated elsewhere, particularly one from the original exposed silver halide grain different area. This type of transfer has many advantages. So you get z. B. a fixed negative image of high density and high contrast from such a thin one Silver halide emulsion layer that with normal development only a relatively moderate density and would achieve poor contrast.

After the silver halide has dissolved in the exposed areas, the unexposed silver halide remains - probably in complex form, but still sensitive to light - back. If you break the development Such a silver halide emulsion and fixed in the dark, one obtains in the silver halide - Emulsion layer a negative image and also the negative transfer image.

One way of producing a positive image in the silver halide emulsion layer without special reagents is that the in the Unexposed silver halide remained in the emulsion layer after removal of the exposed silver halide z. B. is subjected to an overall exposure or treatment to make it developable. You can use a normal bath or just a reducing agent that does not contain a silver halide developer needs to be use.

It is true that the exposed silver halide can be mixed with a corresponding amount of a silver halide agent, such as sodium thiosulfate, preferentially dissolve, however this is not as effective as a combination a complexing silver halide solvent and an additional complexing compound, namely the dissolution accelerator. This The combination is particularly applicable to negatives and when using silver-precipitating agents and gives higher image densities and faster developing products.

The terms »sensitivity« or »speed of development of a light-sensitive material« and »exposure index« are often used here. The "sensitivity" of a photosensitive material is generally understood to be an empirically derived relative value that is the reciprocal of the exposure required to achieve the desired result. The American Standards Association recently issued guidelines for evaluating light-sensitive materials. According to this, the "emulsion speed" is inversely proportional to the minimum exposure value for negative material of an object or motif with minimal brightness, in order to see details, in order to produce excellent images. These guidelines also deal with the creation of blackening or gradation curves (H& D curves) of a negative material in which the logarithm of the exposure of the negative is plotted against the blackness or density (log it / D). The numerical value of the sensitivity from this curve is equal to the reciprocal value of the exposure value E, for which the increase is 0.3 times as large as the increase in the area log E = 1.5, if E is the minimum exposure (ASA Publication PH 2.5 - 1954, "American Standard Method for Determining Photographic Speed and Exposure Index").

The A. S.A. sensitivity value (A. S.A. speed rating) is from the A.S.A. exposure index for light meters and calculators (exposure index). The A.S.A. exposure index is a Quarter of the A. S.A. sensitivity. This exposure index generally gives the correct exposure with an A.S.A. light meter for pictures high quality.

The ASA sensitivity value must be further distinguished from the "exposure index in diffusion transfer processes". In diffusion transfer processes, the exposure index can be based on the curve of the exposure of the negative versus the image density of the transfer positive. The exposure index in diffusion transfer processes can be determined from the blackening curve, namely the reflection or transmission density of the transfer image as a function of log E of the negative emulsion at 0.50 above fog or above D _min .
In a preferred embodiment of the method according to the invention for producing diffusion transfer images, conventional cameras can be used. The developer composition preferably also contains a high molecular weight, film-forming, viscosity-increasing, alkali-resistant material or thickener such as sodium carboxymethyl cellulose or hydroxyethyl cellulose. It is distributed in a known manner (U.S. Patent No. 2,543,181) and, in particular, is contained in a frangible container.

The image-receiving layer preferably contains one or more silver-precipitating agents or nuclei for Structure of the silver image, e.g. B. metal sulfides and selenides, colloidal metals such as silver and gold, thiooxalates or thioacetamides. These are preferably in a macroscopically cohesive layer from submacroscopic agglomerates of very small particles of a water-insoluble inorganic, preferably silicon-containing material, such as silica airgel, embedded (USA. Patents 2,698,237, 2,698,245 and 2,774,667). The image-receiving layer can also contain a dispersion of silver-reducing agents or precipitating substances or initiators in the developer compound, so that the silver over-

bearing image is created (US Pat. No. 2,662,822). Finally, the developer composition can contain a substance that changes the hue of the silver transfer image shifted more against blue-black or neutral (USA, patent 2 984 565).

A special feature of the method according to the invention is that negative transfer images already obtained with exposure indices at which the selected aperture and shutter speeds would normally result in 1, 2, or more stops underexposure. In the examples the exposure is indicated by the "aperture values", these result from the aperture and the shutter speed. The next f-stop leads to a doubling of the value incident on exposure Amount of light; the higher the value, the lower the exposure, and the higher the exposure index, by this is the higher the aperture value for a given brightness.

IO

Aperture value Exposure time cover 1 1/25 // 5.6 2 1/25 //8th 3 1/25 // 11 4th 1/25 // 16 1/100 ■ // 8 5 1/25 // 22 1/500 // 5.6 6th 1/25 // 32 1/500 //8th 7th 1/25 // 45 1/500 // 11 8th 1/25 // 45 1/500 // 22 9 1/100 // 45

20th

30th

35

40

At a luminance of z. B. about 18 cd / m ² , that is normal light conditions in the open air, a diffusion transfer film with ASA index 200 would usually be exposed at an aperture value of 6 and a film with ASA index 1600 at an aperture value of 9. (In the examples, the exposures were made - unless otherwise stated - through a step wedge with the aid of a fluorescent tube; a diffusion transfer film with ASA index 200 would have to be exposed under these conditions at an aperture value of 2.)

The process according to the invention can be used and produced over a wide temperature range Generally between 0 and 38 ° C better sensitometer values than one would get with usual positive ones Silver transfer process can be obtained. This is probably due to the fact that the relative speed of Resolution and development are pretty much the same initially. You can change this through temperature changes Make relationship closer. It was found that the process according to the invention in terms of reproducibility is no more sensitive than conventional silver transfer processes. Under certain circumstances even in the method of the present invention, the uniformity of the image quality is better.

The silver halide in the non-image area of the emulsion layer remains despite the action of Reagents believed to form light-insensitive salts or complexes still always sensitive to light.

It should be noted that according to the invention there is no "fixing" or "stabilizing" of the silver halide in the non-image areas with the formation of a light-insensitive, relatively insoluble salt or Complex takes place, but the undeveloped and undissolved silver halide in the non-image areas the silver halide emulsions remain light sensitive. This is in contrast to common photo processes, where fixation is necessary to inactivate undeveloped silver halide in situ, z. B. with sodium thiosulfate, potassium thiosulfate, thiourea or with a fixing developer containing z. B. 6-Amino-4-hydroxy-2-mercaptopyrimidine, 4-amino-6-hydroxy-2-mercaptopyrimidine (U.S. Patent 2 525 532). .

It is believed that the complex transferred is a complex of the silver halide with the silver halide - Solvent and the dissolution accelerator. Invisible transference images are capable of absorb ultraviolet light. The usual complex of silver halide with an alkali metal thiosulfate cannot absorb ultraviolet light, but absorbs l-phenyl-5-mercaptotetrazole ultraviolet light. Although it is possible that the l-phenyl-5-mercaptotetrazole also somehow with the silver complex is transferred image-wise into the image-receiving layer, it appears to be more likely be that the l-phenyl-5-mercaptotetrazole is part of a novel complex with the silver halide solvent and the silver halide.

The addition of a higher molecular weight thioether such as alkyl polyoxyethylene thioether increases the sensitivity in some cases up to three values, making the negative transfer easier overall (U.S. Patent 2,938,792).

According to the method according to the invention, additive color images can also be obtained if the light-sensitive silver halide emulsion exposed over a grid of additive color, the silver halide transferred from the image areas to another layer and that which remains in the image-free areas Overall exposure and development of silver halide; a positive silver image is obtained, which corresponds to the picture in the color grid.

In another embodiment, the transferred silver halide can be used in the presence of a color developer and color couplers are reduced to a dye image; the precipitated silver can subsequently bleached out so that only the color image is in the original image receiving layer remains behind. In such an embodiment, the color coupler can be non-diffusing and are initially in the image receiving layer; the same developer is used for both images used. The developer oxidation product in the image areas is fixed, i. i.e., it cannot transmit because it has reacted with the nondiffusible coupler in the emulsion layer. Man may provide such a coupler as a substantially colorless coupling product in the emulsion layer supplies. The silver transfer image obtained according to the present invention can also be used for manufacture of a color image after the silver dye bleaching process. ■

Because of the remarkably high sensitivity to light possibility that in the processing according to the invention

109 533/30

example 1

A commercially available,
material with
Hi

Water.. "

Hydroxyethyl cellulose

Sodium hydroxide

Sodium sulfite .....

Potassium thiosulfate

Diethylamine

Ascorbic acid

4,6-diamino-o-cresol

Sodium sulfide solution
(156 mg / cm ³ Na ₂ S)

Lead and cadmium acetate solution
(100 cm ³ H ₂ O, 2.9 g lead acetate,
2.1 g cadmium acetate)

l-phenyl-5-mercaptoterazole

9.1 cm ³
0.41 g
0.26 g
0.33g
0.14 g
0.5 cm ³
0.6 g
0.02 g

0.011 cm ³

0.34 cm ³
0.03 g

ok

of the photographic recording material is obtained, the process according to the invention is suitable especially for poor lighting conditions, such as in X-ray photography, for photography of oscilloscope screens, at night and the like Procedure only reverses the nature of the picture in whole or in part, one can get information about one like this Capture a large range of exposure photographically as if you were actually a continuous photometer had.

The process according to the invention is explained in more detail using the following examples:

In these examples the sodium thiosulfate was used as the pentahydrate Na ₂ S ₂ O ₃ · 5H ₂ O, the sodium sulfite anhydrous and the potassium thiosulfate likewise anhydrous. The amount of silver per unit area was determined by fluorescent X-ray analysis.

The preferred silver halide emulsion is silver bromide or silver iodobromide, but it is also an emulsion made of silver chloride with the usual sensitivity of copier papers (e.g. Kodak Azo- and Kodak Kodabromide copier paper). The emulsions can be any, e.g. B. panchromatic, be sensitized.

In general, better results are obtained with thin developer layers; H. that development takes place over a very small distance. The presence of potassium ions appears to carry over to accelerate, so the potash salts are often preferred. The concentration of the various Reagents can vary depending on the emulsion layer and other factors. Concentrations from 1 to 35 g / l of 1-phenyl-5-mercaptotetrazole are particularly useful. The concentration the silver halide solvent varies with the concentration of the dissolution accelerator; Sodium thiosulphate solutions of 20 to 80 g / l can be used together with l-phenyl-5-mercaptotetrazole.

40

photographic record of photosensitive silver ²

Halide emulsion layer (1.001 mg Ag / cm ² ) was exposed at a f-stop value of 6 and a developer mixture was applied in a layer thickness of approximately 56 μm between the exposed layer and a superficially hydrolyzed cellulose acetate film. The developer mix contained

5 °

After an exposure time of 3 minutes, the cellulose acetate film was separated from the negative. The layer of developer mixture on the cellulose acetate film then contained a negative silver transfer image.

Silver halide emulsion layers of different sensitivity can be used and apply different layer thicknesses of the developer composition, e.g. B.

Silver halide emulsion layer with 0.716 to 0.729 g / cm ² Ag at 46 μm layer thickness of the developer composition for f-number 5;

Silver halide emulsion layer with 0.877 mg / cm ² Ag at 66 μm layer thickness of the developer composition for aperture value 3;

Silver halide emulsion layer with 0.758 mg / cm ² Ag at 66 μm layer thickness of the developer composition for f-number 5;

Silver halide emulsion layer with 0.734 mg / cm ² Ag at 40 μm layer thickness of the developer composition for a f-stop value of 6, but with 0.07 g of 1-phenyl-5-mercaptoterazole in the developer composition;

Silver halide emulsion layer with 0.733 mg / cm ² Ag, aperture value 3, layer thickness of the developer composition 60 μm with 0.09 g of l-phenyl-5-mercaptotetrazole;

Silver halide emulsion layer with 1.172 mg / cm ² Ag, aperture value 5, layer thickness of the developer composition 50 μm, 0.07 g of 1-phenyl-5-mercaptotetrazole, 5 minutes;

Silver halide emulsion layer with 0.509 mg / cm ² Ag, aperture value 4, layer thickness of the developer composition 50 μm, 0.12 g of l-phenyl-5-mercaptotetrazole, 4 minutes.

Example 2

An exposed, commercially available photographic recording material 0.603 mg / cm ² Ag in the silver halide emulsion layer (aperture value 5) was treated with a developer material in a layer thickness of 60 μm of the following composition:

Water 124 cm ³

Sodium sulfite 5 g

Sodium carboxymethyl

cellulose 5.5 g

Ascorbic acid 9 g

4,6-diamino-o-cresol 0.3 g

Diethylamine _; 7.5 cm ³

Sodium hydroxide 3.85 g

Potassium thiosulfate 7.2 g

Sodium sulfide solution

(156 mg / cm ³ Na ₂ S) 0.177 cm ³

Lead acetate cadmium acetate

Solution (100 cm ³ H ₂ O,

2.9 g lead acetate, 2.1 g cad

mium acetate) 5.25 cm ³

l-phenyl-5-mercaptotetrazole ... 0.38 g

The following variations can be made with equally good results: Silver halide emulsion layer with 0.107 to 0.12 mg / cm ² Ag, aperture value 8V ₂ , layer thickness of the developer compound 38 μm, plus 0.1 g of potassium thiosulfate, developer compound without sodium hydroxide and diethylamine, but with 0 , 35 g of potassium hydroxide; Developer composition without sodium hydroxide, but with a diethylamine concentration of 1.6 cm ³ ; Developer composition without diethylamine.

Example 3

An exposed, commercially available photographic recording material with 0.107 to 0.12 mg / cm ² Ag

in the silver halide emulsion layer, aperture value 5, developer compound with 66 μm layer thickness the following composition between negative and surface hydrolyzed cellulose acetate film:

Water 920 cm ³

Sodium carboxymethyl

cellulose 38.9 g

Sodium hydroxide 25.8 g

Sodium sulfite 33 g

Potassium hydroxide 10 g

Potassium thiosulphate 48 g

Hydroquinone 10 g

l-phenyl-5-mercaptotetrazole ... 3 g

Metol .. 30 g

Diethylamine 50 cm ³

This system did not contain any silver precipitant. After 4 minutes the cellulose acetate sheet was covered with the developer layer is separated from the developed negative. The still wet developer layer was for that Completely transparent to the eye. It was quickly put in an enlarger and still wet on copied ordinary enlarging paper with a UV-rich light source. After usual wet development a good positive image was obtained on the copy paper. In the developer layer there was an invisible, UV-opaque image of the transferred silver complex, which looked like a negative.

In a modification of this method, the developer layer was dried on the carrier and thus the transferred silver complex precipitated. A visible image was obtained in the form of a white precipitate. The precipitated complex was relatively opaque; he reflects and scatters the light, so that the image areas appear white in incident light and black in transmitted light. According to general In appearance and usability, the image obtained in this way is similar to a bubble image.

Another possibility is to combine the cellulose acetate film separated from the negative with the wet To quickly apply a developer layer to an image-receiving layer containing a silver precipitating agent. After a few seconds a silver transfer image began to build up through the back the transparent cellulose acetate film could be observed. After reaching the appropriate Image density was peeled off the image receiving layer. The duration of this second exposure varies, but good results can be obtained in approximately 5 to 10 minutes.

B e i s ρ i e 1 4

Between an exposed (aperture 6), commercially available photographic recording material and 0.1523 mg / cm ² Ag in the silver halide emulsion layer and an image receiving material customary in silver salt diffusion processes, a developer material was applied in a thickness of 56 μm of the following composition:

Water 850 cm ³

Hydroxyethyl cellulose 32.5 g

Sodium sulfite 53.3 g

Sodium thiosulfate 19.3 g

Sodium hydroxide 40.5 g

Toluohydroquinone 35.6 g

and 5 mm ³ / cm ^{3 of} 2-mercaptoethyl sulfide. After 2 minutes the image-receiving element with the negative silver transfer image was separated from the negative.

It is also possible to use a developer composition containing 6 mg of 2-mercapto-5-furyl-1,3,4-oxadiazole a development time of 1.5 minutes or 7 mg of 2 - mercapto - 4 - methyl - pyrimidine hydrochloride an exposure time of 5 minutes.

B e i s ρ i e 1 5

A silver halide emulsion was produced as follows: 60 cm ^{3 of} a solution of 30 g of silver nitrate in 360 cm ^{3 of} water at 60 ^° C. were converted into a solution of 54.6 g of ammonium bromide, 6.1 cm ^{3 of} a 15% strength

Potassium iodide solution, 4.5 cm ^{3 of} a 28% strength ammonium hydroxide solution and 30 g of gelatine were ^{stirred into 660 cm 3 of} water at 70 ° C. and, after 8 minutes, the remaining silver nitrate solution was added. After 5 minutes, the first half of a solution of

60 g of silver nitrate in 360 cm ^{3 of} water at 60 ° C within 1 minute and after 10 minutes the second half is added within 1 minute. After 2 minutes, the reaction mass was rapidly cooled ^{below 20 ° C.}

The emulsion was precipitated with a 50 percent strength by weight ammonium sulfate solution and the precipitate was washed out until the supernatant liquid had a conductivity of 500 μΩ / cm. 33 g of active gelatin were added to the washed precipitate, the gelatin was dissolved and the precipitate was ^{melted at 35 °} C., the volume of the emulsion was ^{adjusted to 800 cm 3} , the pH to 6.0 and pAg to 8.9, heated to 60 ° C. and 1 cm ^{3 of} a gold thiocyanate sensitizer (0.25 mg gold and 10 mg ammonium thiocyanate) was added. The emulsion matured to optimum sensitivity in 95 minutes; then the pAg was adjusted to 9.10 and the emulsion was cooled. It contained silver and gelatin in a ratio of 1: 1, that is 66.2 mg / cm ³ Ag.

The coating was carried out with a solution of 3 g of gelatine, 10 g of emulsion, 40 cm ^{3 of} water and 0.25 cm ^{3 of} a 25% wetting agent solution (Triton X-100). It was applied to a cellulose acetate film base (243.84 cm long, 12.7 cm wide) at a speed of 304.8 cm / min (remainder of the solution 15.5 g). This photographic material was then exposed at aperture 5 and developer material was applied in a layer thickness of 51 μ and a customary image receiving element was applied to it. The developer compound contained

Water 9.2 cm ³

Sodium carboxymethyl

cellulose (medium viscosity) 0.15 g

Sodium carboxymethyl

cellulose (high viscosity) 0.26 g

Sodium sulfite 0.33 g

Sodium hydroxide 0.26 g

Potassium hydroxide 0.1 g

1-phenyl-5-tnercaptotetrazole 0.05 g

Amidol 0.60 g

Potassium thiosulfate 0.48 g

Diethylamine 0.5 cm ³

After 4 minutes the image-receiving element was separated and the developer layer washed, in the image-receiving element had a negative silver transfer image.

Example 6

A fine-grained, light-sensitive recording material for radiography (0.1932 mg / cm ² Ag) was exposed at aperture 4 and 46 μ thick developer compound was applied between this and a surface hydrolyzed cellulose acetate film as a layer carrier.

Water 920 cm ³

Sodium carboxymethyl cellulose 38.9 g

Ascorbic acid 60 g

4,6-diamono-o-cresol 2 g

Diethylamine 50 cm ³

Sodium hydroxide 25.8 g

Potassium thiosulfate 42 g

Sodium sulfide solution

(156 mg / cm ³ Na ₂ S) 1.18 cm ³

Lead acetate cadmium acetate

Solution (100 cm ³ H ₂ O,

2.9 g lead acetate; 2.1g Cad

mium acetate) 35.5 cm ³

Sodium sulfite 33 g

l-phenyl-5-mercaptotetrazole ... 2.2 g

and D _min 0.33 (base blackening = 0.25), that is, a much lower sensitivity.

Example 8

Five strips of highly sensitive, panchromatic negative photographic material (0.1533 mg / cm ² Ag) were exposed at aperture values 3, 5, 7, 9 and 11, respectively, and the latent image was coated with a 46 μm thick layer of developer composition and a

ίο Image receiving element covered. 1 1 developer compound contained

Sodium carboxymethyl cellulose (medium viscosity) 13.9 g

Sodium carboxymethyl

cellulose (high viscosity) 25 g

Potassium thiosulphate 48 g

Sodium sulfite 33 g

Potassium hydroxide 10 g

Metol 30 g

Hydroquinone 10 g

Diethylamine 50 cm ³

Sodium hydroxide 25.8 g

l-phenyl-5-mercaptotetrazole 3 g

After 3 minutes, the image receiving material was separated from the recording material in the dark, in of the developer layer on the hydrolyzed surface of the cellulose acetate film was a negative silver transfer image.

The separated recording material was washed in the dark, exposed again and placed in a dish with a silver halide developer, which could be followed visually. The maximum density was reached in about 1 to 2 minutes. It was then placed in a fast-acting, acidic fixer, hardening took place, but no real fixation. The positive silver image in the emulsion layer showed when viewed through D _max 1.80 and D _mi “ 0.88.

B e i s ρ i e 1 7

A silver halide emulsion with silver precipitating colloidal gold was made on barytaised paper applied, exposed with aperture value 2 and between this negative material and a surface hydrolyzed Cellulose acetate film is applied as a carrier with a 26 μm thick layer of developer composition.

Water 9.1 cm ³

Sodium carboxymethyl cellulose 0.39 g

Sodium hydroxide 0.257 g

Potassium thiosulfate 0.28 g

Sodium sulfite 0.33 g

Ascorbic acid 0.6 g

4,6-diamino-o-cresol 0.02 g

Diethylamine ... · .. ■ 0.5 cm ³

1-phenyl-S-mercaptotetrazole 0.022 g

After 3 minutes, the photosensitive member with the latent image was separated in the dark and fixed for 3 minutes. A very dense negative silver image D _max 3.05 and D _min 0.4 (base blackening 0.25) was obtained in the emulsion layer. No silver deposition occurred in the non-image areas, despite the fact that a precipitating agent was present in the emulsion layer. A comparative emulsion without silberausfällendes agent yielded under the same conditions, a negative image with D _max 0.85 After 3.5 minutes, the image-receiving element was separated from the recording material and the sensitometric curves (log i ■ t) against D for each silver transfer image is determined (F i g. 1). The image density, the type of image formation and the exposure indices of the transfer images obtained at the various aperture values are compiled in the table below.

In the case of positive transfer images, the density of the image silver decreases with increasing exposure, on the other hand, the density of the image silver increases with increasing exposure in the case of the negative transfer images.

Image type *) Transmission sity Exposure index ildart Bezels
worth + The 0.33 for B -. - 3 +, - 2.49 0.37 500 23,000 5 +, - 2.50 0.35 550 16,000 7th +, - 2.43 0.35 1600 32,000 9 - 2.48 0.58 1100 30,000 11th 2.55 -. -

50

55 = positive transfer images. = negative transfer images.

The indices were determined 0.5 units over D _mi “ in transmission. Particularly striking is the similarity of the blackening curves, the maximum blackening, regardless of whether with the + or - type of transfer image and the remarkably greater sensitivity for negative transfer images than for positive transfer images.

The image-receiving element used here was prepared as follows: Gold was vapor-deposited from a wire in a vacuum (about 10 ~ ⁴ mm Hg) to 50 g triacetate flakes; namely 2.6 percent by weight; 11 g of this product were dissolved in 109 cm ^{3 of} ethyl acetate, 36 cm ^{3 of} methanol and 3 cm of water and painted on 9 μm thick baryta paper. The surface of the cellulose acetate layer was hydrolyzed to cellulose (USA. Patent

script 3 078 178), about half the layer thickness. .

Example 9

A highly sensitive panchromatic negative photographic material (0.1533 mg / cm ² Ag) was exposed at an aperture value of 8 and a developer mixture 56 μm thick was applied between this and a conventional image receiving element:

Water 9.2 cm ³

Sodium carboxymethyl cellulose ... 0.39 g

Sodium sulfite 0.64 g

Sodium hydroxide 0.49 g

Toluhydroquinone 0.36 g

Sodium thiosulfate 0.23 g

5-nitroindazole 0.05 g

After 2 minutes the image-receiving element was separated containing a negative silver transfer image.

Example 10

A fine-grain silver halide X-ray photographic material of low sensitivity (0.1934 mg / cm ² Ag) was exposed through a 1.0 neutral density filter for 1 second with a 7.5 W lamp at a distance of 1.2 m and after Example 1 treated further, but a 66 μm thick developer layer was used. After 3 minutes, this contained a silver transfer image made up of both negative and positive image parts.

If the developer was applied 0.2 seconds before exposure, a very similar one was obtained Silver transfer image, but with a slightly lower degree of blackening.

Example 11

The photographic material of Example 10 was exposed for V25 seconds (// 4.5) and between this Negative material and a surface hydrolyzing cellulose acetate film developer compound 46 μΐη applied:

Water 9.0 cm ³

Sodium carboxymethyl cellulose 0.4 g

Sodium sulfite 0.33 g

Potassium thiosulfate 0.14 g

Diethylamine 0.5 cm ³

Ν, Ν-diethyl hydroxylamine 0.7 cm ³

Sodium hydroxide 0.26 g

Sodium sulfide solution

(156 mg / cm ³ Na ₂ S) 0.012 cm ³

Lead acetate-cadmium acetate solution (100 cm ³ H ₂ O,
2.9 g lead acetate, 2.1 g cad

mium acetate 0.36 cm ³

1-phenyl-5-mercaptotetrazole 0.025 g

After 3 minutes, the cellulose film with the image-bearing developer layer was peeled off.

Example 12

The measures of Example 11 were carried out with a slightly different 86 μ thick developer layer repeated.

Water 9.0 cm ³

Sodium carboxymethyl cellulose 0.4 g

Sodium sulfite 0.33 g

Potassium thiosulfate 0.14 g

2,6-dimethoxy-4-amino-

phenol hydrochloride 0.08 g

Ascorbic acid 0 _r 6 g

Diethylamine 0.42 cm ³

Sodium hydroxide. 0.26 g

Sodium sulfide solution

(156 mg / cm ³ Na ₂ S) 0.012 cm ³

Lead acetate cadmium acetate

Solution (100 cm ³ H ₂ O,

2.9 g lead acetate, 2.1 g cad

mium acetate). 0.36 cm ³

2-thio-6-azauracil 0.05 g

A negative silver transfer image was obtained in the developer layer.

B e i s ρ i e 1 13

The procedures of Example 12 were carried out with a commercially available copy paper, exposure 0.2 seconds, development 5 minutes, repeated. A negative transfer image was obtained in the Developer layer.

B e i s ρ i e 1 14

A medium to high sensitivity orthochromatic negative photographic material with paper backing (0.1958 mg / cm ² Ag) and a developer layer 63 μm containing

Water 91.0 cm ³

Hydroxyethyl cellulose 3.9 g

Potassium thiosulfate 2.8 g

Sodium sulfite 3.3 g

Ascorbic acid 6.0 g

4,6-diamino-o-cresol ......... 0.2 g

Diethylamine 5.0 cm ³

Sodium hydroxide 2.5 g

Sodium sulfide solution

(156 mg / cm ³ Na ₂ S) ......... 0.118 cm ³

Lead acetate cadmium acetate

Solution (2.9 g lead acetate,

2.1 g cadmium acetate,

100 cm ³ H ₂ O) ....... ': ...... 3.55 cm ³

l-phenyl-5-mercaptotetrazole ... 0.22 g

on a superficially hydrolyzed cellulose acetate film were developed after exposure (aperture value 3) for 10 minutes. The blackening curve of the negative silver transfer image in the developer layer upon transmission is shown in FIG. 2, curve B. If a developer composition without 1-phenyl-5-mercaptotetrazole is used, a positive silver transfer image (curve A) is obtained after an exposure time of 1 minute. The negatives of all these tests were fixed in the dark and the blackening curves (reflection) were determined: Fig. 2, curve D, after 10 minutes with l-phenyl-5-mercaptotetrazole and curve C after 1 minute without l-phenyl-5-mercaptotetrazole. In curve C, the background density of 0.24 has been taken into account. Development with 1-phenyl-5-mercaptotetrazole in 1 minute gave a pale negative transfer image. The fixed negative image developed from the image areas of the negative resulted in curve E. The similarity including the maximum densities of the curves, in particular curves C and D as well as curves B and A.

109 533/302

1 O4 / SOD

B e i s ρ i e 1 15

The X-ray photographic material of Example 10 (aperture value 4) and non-viscous developer containing

Water 180 ecm

Sodium hydroxide 5.2 g

Potassium thiosulfate 7.0 g

Sodium sulfite 6.6 g

Ascorbic acid 12 g

2,4-diamino-o-cresol 0.4 g

Diethylamine,. 10 ecm

l-phenyl-4-mercaptotetrazole 0.4 g

gave after 3 minutes of development and washing and one more total exposure and development - namely 2 to 3 minutes - a weak positive image in the emulsion layer.

If, as a modification of this, the exposed photographic material is dipped in the liquid developer again subjected to a total exposure for 3 minutes and another 2 to 3 minutes in the developer left, a good positive image was obtained.

Example 16

The photographic material of example 14 (f-number 7) and a developer layer, 56 µm containing

Water 100 ecm

Sodium carboxymethyl

cellulose 5.0 g

Sodium hydroxide. 15.0 g

Uracil 11.25 g

Ammonium hydroxide solution,

29.4% at 3.5 cm

Ν, Ν-diethylhydroxylamine 7.5 ecm

1-phenyl-5-mercaptotetrazole 0.2 g

produced a negative transfer image in an image receiving element after 4 minutes.

An exposure with aperture value 6 and a development time of 3 minutes resulted in a negative one Transfer image of slightly lower density.

Example 17

A roll film (US Pat. No. 2,579,587) made of a highly sensitive, panchromatic negative photographic material (0.1533 mg / cm ² Ag), an image receiving element and a bag with the developer composition of Example 5 was placed in a self-developing camera at light value 10 and aperture value 1 in a room only exposed to daylight and after about 1 minute the image-receiving element separated from the negative material, it contained a negative silver transfer image of good quality.

If it is now exposed again with artificial room lighting and the same light value, one obtains a positive silver transfer image after 1 minute in the image-receiving element.

However, for comparison with light value 10 (aperture value 1) without room lighting with the same photographic material (equivalent A-S-A. exposure index 3200) exposed, a positive silver transfer image was obtained after 10 seconds. If this comparison experiment was repeated with room lighting, the correct light value is 13 at an aperture value of 4. In this way, you can already use an equivalent for photographic materials A.S.A. exposure index of only 400 a positive transfer image and with an equivalent A.S.A.

Exposure index of 3200 obtained a negative transfer image.

Comparison 1

A high-speed, high-speed, panchromatic negative photographic material (0.1554 mg / cm ² Ag), an image-receiving element and a developer composition in a thickness of 46 μm

Water 9.0 ecm

Sodium carboxymethyl

cellulose 0.4 g

Potassium hydroxide 0.1 g

Sodium sulfite 0.33 g

Sodium hydroxide 0.26 g

Diethylamine 0.5 ecm

Potassium thiosulfate 1.4 g

2,4-diaminophenol

dihydrochloride 0.6 g

were used to produce a negative transfer image with D _max 1.05, D _min 0.05 after a development time of 4 minutes in the image-receiving element, which is freed from surface silver and residual developer. It was found that with a higher potassium thiosulphate concentration, the negative transfer images can be obtained in as little as 20 seconds, but the density of the transfer image is lower.

Comparison 2

Copy paper of Example 13 was exposed for V10 seconds and 89 μΐη developer composition between the Paper and a baryta paper carrier.

Water 9.1 cm

Sodium carboxymethyl

cellulose 0.4 g

Ascorbic acid 0.6 g

Sodium sulfite 0.6 g

Sodium hydroxide 0.26 g

Sodium sulfide solution

(156 mg / cc Na ₂ S) 0.011 ecm

Lead acetate cadmium acetate

Solution (2.9 g lead acetate,

2.1 g cadmium acetate,

100 ecm H ₂ O) 0.34 ecm

After 3 minutes, the carrier with the developer layer was peeled off, in which a negative silver transfer image Template. In this mass is called a SiI overhalide solvent contain only sodium sulphite and ascorbic acid as a developing agent.

Claims (10)

Patent claims: 1. Process for the production of photographic images, in particular by the silver salt diffusion process, in which a photosensitive silver halide emulsion layer is exposed imagewise and with an aqueous alkaline one Developer mixture is treated containing a) a silver halide developer substance, b) a complexing silver halide solvent and c) as an additional complex-forming compound, a mercapto compound with the structural elements CTT —N = C-N— or or SH
-N = CO- SH
—N = CS- those with silver ions one versus silver ίο halide forms less soluble compound, or a nitrobenzimidazole derivative, a nitroindazole derivative, a benzotriazole, an 8-azaxanthin, a 6-benzylaminopurine, a 2,6-dimercaptopurine, a 2,2'-dimercaptodiethyl sulfide or a thiourea, and in which, if necessary, a transfer to a separate image receiving material takes place, characterized in that d) by an imagewise exposure in which the silver halide is exposed just enough, that it begins to become developable, e) by using the complex-forming agents that act as dissolution accelerators Compound (c) in a concentration of at least 1 g / l of the developer mixture and f) by adhering to the specific development time, a preferred dissolution of the silicon overhalide in those exposed parts of the image in which development has already started has brought about, while unexposed silver halide does not yet dissolve got. 2. The method according to claim 1, characterized in that there is an additional complex-forming Compound l-phenyl-5-mercaptotetrazole used. 3. The method according to claim 1 or 2, characterized in that by drying the Image receiving layer the image silver precipitates out of the complex. 4. The method according to claim 1 or 2, characterized in that an image receiving layer, containing a silver precipitating agent. 5. The method according to claim 1 or 2, characterized in that a treatment mixture, containing a silver precipitating agent. 6. The method according to claim 1 or 2, characterized in that there is an emulsion layer which contains a silver precipitating agent before exposure, and the silver halide complex reduced to a negative silver image in the emulsion layer. 7. The method according to claim 1 or 2, characterized in that the developed silver halide emulsion layer with the image-wise distributed, diffusible, UV-absorbing complex for the production of a positive one Image by means of UV exposure of a conventional photographic recording material as a master copy used. 8. The method according to claim 1 or 2, characterized in that the dissolved silver halide complex removed from the emulsion layer without prior fixing of an overall exposure subjugates and develops the positive image built up by it. 9. The method according to claim 1 or 2, characterized in that the dissolved silver halide complex transfers from the emulsion layer into an image-receiving layer and a negative silver image precipitates in this. 10. The method according to claim 1 to 9, characterized in that the silver halide solvent Sodium or potassium thiosulfate is used. 1 sheet of drawings