DE2529488A1 - PHOTOGRAPHICAL MATERIAL FOR THE DYE DIFFUSION TRANSFER PROCESS - Google Patents

Description

- 1 JUL11575

AGFA-GEVAERTAG

PATENT DEPARTMENT

LEVERKUSEN 2529488

Hs / Schä

Photographic material for dye diffusion transfer process

The invention relates to a photographic material for manufacture positive, colored transfer images after the dye diffusion transfer process / the at least one light-sensitive, non-fogged direct positive silver halide emulsion layer and associated therewith contains at least one non-diffusing, coloring compound, and that in one its layers contains agents which, with a time delay, inhibit development in the light-sensitive layer Provide 1-aryl-5-mercaptotetrazole.

As non-diffusing coloring compounds are in particular to understand those which, as a result of development, are able to set free a diffusing dye. Such coloring compounds and their applications are described, for example, in DT-PS 1 095 115, DT-OS 1 930 215 and DT-OS 1 772 929, DT-OS 2 242 762, DT-OS 2 406 664 and German patent application P 25 05 248.6.

All these coloring compounds have in common that they are negative-working systems, i.e. in connection with conventional negative silver halide emulsions, an image-wise distribution is obtained which is consistent with the negative silver image diffusing dyes generated. In order to generate positive, colored transfer images, it is therefore necessary either when using common negative silver halide emulsions of a suitable one photographic reversal process, or it must be used instead of the

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union negative emulsions a direct positive silver halide emulsion can be used, which gives positive silver images with a simple development. The present invention relates relate to dye diffusion transfer processes with unveiled direct positive silver halide emulsions.

Such unfogged direct positive silver halide emulsions set diffusing image dyes from the coloring compounds in the veiling development at the unexposed areas free, while essentially no development takes place in the exposed areas. When the direct positive silver halide emulsion however, for a long time in the presence of developer compounds with an alkaline processing compound in Contact stands, which is inevitably the case, for example, in so-called mono-sheet materials, since the lowering of the If the pH value only occurs with a delay, a certain development also takes place in the exposed areas, which is undesirable Fog, i.e. leads to poor image whites.

The invention is based on the object of suppressing this undesirable development fog and thus the image defects to enhance.

It has been shown that this goal with certain derivatives of 1-phenyl-5-: mercaptotetrazole, which are in one or more of the Layers of the photographic material are incorporated, can be achieved. With the connections suitable for this purpose the mercapto group is blocked by a group that can be split off under the conditions of alkaline development and / or the phenyl group contains further substituents. The free i-phenyl-5-mercaptotetrazole is not suitable. The connections are generally added to a non-photosensitive binder layer, from which they are developed with a certain amount of Delay, which can apparently be controlled by the number and size of the substituents in the 1-phenyl group, into the

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diffuse light-sensitive direct positive silver halide emulsion layer. The mercapto-blocked compounds can also be added to the silver halide emulsion layer itself. Here the delay is primarily achieved by the fact that the residue which can be split off has to be split off with liberation of the i-phenyl-5-mercaptotetrazole which may be substituted in the phenyl group. The delay mechanism thus comes about because / that a chemical reaction and / or a controlled diffusion process must take place / before the mercaptotetrazole compound takes effect in the silver halide emulsion layer.

So-called antifoggant precursor compounds are known in principle, e.g. from US 3,575,699, US 3,649,267 and DT-OS 2 427 183. These publications deal with color diffusion transfer processes using developer dyes in combination with negative silver halide emulsions. With the delayed action of the antifoggants or development retarders, there is better color separation is achieved by preventing a silver halide emulsion layer from interacts with the diffusing developing dye compound of another color unit. Such There is no measure in the photographic material according to the invention which contains non-diffusing coloring compounds necessary.

The invention relates to a photosensitive photographic material Material for producing positive colored images by the color diffusion transfer process, containing a transparent support, an image receiving layer, a light reflective pigment layer, and in the following order a photosensitive element having at least one photosensitive, non-fogged direct positive silver halide emulsion layer and one of these associated non-diffusing

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coloring compound. The light-sensitive material according to the invention is characterized in that it _{contains agents for suppressing development fog in D min} ~ areas in one or more of its layers, the i-aryl-5 which is free in the direct-positive silver halide emulsion layer with a time delay when exposed to an alkaline processing liquid - make mercaptotetrazole available.

Compounds of the following formula are particularly suitable for the invention:

Γ Γ Γ

R-S-C N N C-S-CO-O-X-O-CO-S-C ~~~ "" ν

Il H H H Il Il

N N N N N N

II

in which mean

R is hydrogen or a group that can be split off under the alkaline conditions of development, in particular acyl, whereby the acyl radical is derived from aromatic carboxylic acids (Example: Benzoyl) of carbonic acid monoalkyl esters (Example: n-ButyIoxycarbonyl) or aliphatic or aromatic sulfonic acids (example: methylsulfonyl or p-tolylsulfonyl)

X is an alkylene group, preferably with 2 to 10 carbon atoms, - or an alkylene group interrupted by oxygen (-0-)

Ar is a phenyl group with at least one free o-division, which, however, must have further substituents for R = hydrogen, the total molecular weight of which is between 50 and 120 and of which, if appropriate, two adjacent to one another is a fused carbocyclic Can form a ring. Possible substituents on the phenyl group are, for example: halogen, e.g. chlorine or Bromine, alkyl, e.g., methyl, phenyl or acylamino. If two adjacent substituents are one with each other A-G 1359 - 4 -

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Form fused carbocyclic ring, Ar is for example a 1-naphthyl or 2-naphthyl radical.

Examples of compounds / which are particularly suitable are listed below:

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No. Compound Melting Point (C)

1) N N

Il, I

Cl

Cl

134 (decomp.)

2) ^ -N

156 (decomp.)

3)

N - N Il
N

> ^ SH

133 (decomp.)

4) Ν— Ν

N
\

SH

A-G 1359

NH-CO- (CH ₂ ) ₄ -CH ₃

- 6

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189 (decomp.)

Cl

Cl

A-G 1359

8098S4 / 0941

No.

Compound melting point (C)

it

SH

136.5 (dec.)

N N

<> Il

116 (decomp.)

N Il

S-CO

80

N Il N

S-SO ₂ -CH ₃

130

No. Compound Melting Point (C)

9)

N
U

^S " ^SO 2A_ / ^CH 3

142

10)

Ν —Ν

N Ι ^ N-

Cl

Cl

11) N N

Cl

Cl 108 to 109 (decomp.) 1O7 (decomp.)

12)

S-SO ₂ -CH ₃

Cl

Cl 88 (decomp.)

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link

Melting point (C)

Cl

Cl

S-COO-C ₄ H ₉ _ _n oil

N N

Cl Cl

Cl

N
Il

N N

N _n / S-COO-ZCH ^ ₂ -00C-S ₁

Cl

Decomp. 124-127 C

N N

Cl

Cl Cl

if I

N N

Decomp. 124.5 125.5

Il

N N

Cl Cl

Cl

S-COO-ZCH ₂ J ₆ -OOC-S

Cl

N N

Decomp. 84.5

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No connection

Melting point (C)

17)

Cl

Il

N-

Cl

Cl dec. 53.5-56 ° C

N Il

-N

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The mercaptotetrazoles are produced in a known manner by converting the corresponding thiosemicarbazide into hydrochloric acid with sodium nitrite as for example in Canadian Journal of Chemistry Vol. 35, page 832 (1957), Vol. 37, page 101 (1959) or by reacting the corresponding mustard oil in alcohol with sodium azide, for example in the Journal for Practical Chemistry Volume 133, page 60 (1932) is described.

The preparation of compound 4 is described in US 3,295,976 and the preparation of compounds 7 to 9 is described in DAS 1,173,336. The compounds 10 to 12 can be prepared analogously. The connections 13 to 17 are produced by Implementation of the mercaptotetrazoles with the corresponding chloroformic acid esters in the presence of alkali analogously to those in DT-PS 1 189 380 examples described.

The compounds can be contained in one or more of the layers of the photographic material, for example a photosensitive one Silver halide emulsion layer, in a non-photosensitive binder layer, which is preferably in more or less close spatial relationship to a silver halide emulsion layer is in the light reflecting layer or in the image receiving part, for example in the image receiving layer. The compounds with a free mercapto group (R = H) are expediently not in the light-sensitive layer itself, but stored in another layer, as otherwise they will develop their effect too early in the silver halide emulsion layer, i.e. while the unexposed parts of the image are being developed.

The compounds according to the invention which act as anti-fogging stabilizers are generally used in amounts from 0.005 to 0.5 mol per mol of silver halide are used, preferably in amounts from 0. OT to 0.2 moles per mole of silver halide, this amount being based on the amount of silver halide in the

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Layer on which a preferred impact is intended. The person skilled in the art will easily find the most favorable amount in the individual case determined by simple routine testing. The incorporation takes place according to the methods customary in practice by adding the compounds added to the respective casting solutions in the form of a solution and dispersed therein, e.g. dissolved in a with Water-miscible solvent or in a water-immiscible solvent. Evaporate low-boiling solvents generally before, during or after application, so that the compounds are finely distributed in the layer. In terms of delayed release, it can also prove beneficial if the compounds are in the form of a solution can be introduced into the layer in a high-boiling solvent which is substantially insoluble in water. Such high boiling points Solvents, so-called oil formers or coupler solvents are known, for example, from US Pat. No. 2,322,027, 3,689,271, 3,764,336 and 3,765,897. It is also possible to prepare aqueous dispersions of the compounds and the respective Add casting solutions. For this purpose, aqueous slurries of the compounds are used, for example, by intensive Stir with the addition of sharp-edged sand and / or finely grind by using ultrasound.

The photographic material according to the invention contains at least a photosensitive layer, a so-called non-fogged direct positive silver halide emulsion, which has photosensitivity predominantly in the interior of the silver halide grains. On imagewise exposure of such emulsions forms a latent image predominantly inside the silver halide grains. The development of such unveiled direct positive Silver halide emulsions, however, are made under varying conditions, mainly on the unexposed Make a haze and develop a positive silver image. The unveiled direct positives Silver halide emulsions are characterized in that exposed samples are developed using a typical surface developer of the following composition:

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2529498

p-hydroxyphenylglycine 10 g

Sodium carbonate (crystallized) 100 g make up to 1000 g with water

preferably no silver image / or only one with a very low density, while using an inner nucleation developer of the following composition:

Hydroquinone 15 g

N-monomethyl-p-aminophenol sulfate 15g

Sodium sulfite (anhydrous) 50 g

Potassium bromide 10 g

Sodium hydroxide 25 g

Sodium thiosulphate (crystallized) 20 g

fill up with water to 1000 ml

a silver image of sufficient density should be created _o In any case, the photographic material according to the invention should be exposed in steps of 1/100 to 1 sec. and 3 minutes long development at 20 ^° C. in the above-described internal grain developer achieve a maximum density which is at least three times, but preferably at least five times greater than when developing a material exposed in the same way (development time 4 minutes at 20 ^° C.) in the above mentioned surface developer _o

The required high internal grain sensitivity of the used Emulsions that are due to centers in the grain interior that favor the formation of photolytic silver can be found in can be achieved in the most varied of ways, as particularly favorable silver halide emulsions have been found with grains with a layered grain structure, which consist of silver halide phases with different Contained on various silver halides.

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The irmenkorn sensitivity is determined by the properties of the phase interfaces or phase over-fermentation between the phases, which consist of different silver halides. Such emulsions are, for example, in the German Offenlegungsschriften 2,308,239 and 2,332,802.

Silver halide emulsions, their silver halide grains, are also useful Contain foreign inclusions. These emulsions also generally have a layered grain structure.

They can be made by first preparing a fine grain silver halide emulsion, the grains of which will form the core of the final emulsion. This starting emulsion can be modified chemically or physically on the surface. Then a shell made of the same or a different silver halide is noticed. The preparation of such emulsion is described, for _o example, in German Patent 1,169,290. Reference is also made to American patents 3 206 313, 3 317 322 and 3 367 778, the surface not being obscured in the case of the last-mentioned patent. Further suitable processes are described in American patents 3,447,927, 3,531,291 and 3,271,157 and British patents 1,027,146 and 1,151,782 , Platinum, palladium or iridium, or from nuclei that are formed by reaction with labile sulfur compounds. It is also possible to prepare the silver halide emulsions to be used in the manner according to the invention by precipitating the silver halide grains in the presence of foreign metal ions, in particular polyvalent or polyvalent metal ions. This can be done in such a way that the relevant metal is added during the precipitation ,, aqueous solutions of salts such as are suitable for _o example, salts of 2-valent or trivalent lead 3 of antimony, bismuth, arsenic, gold, Iridium or rhodium and salts of tetravalent platinum or iridium. The concentration of foreign inclusions can

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fluctuate within wide limits. In general, however, amounts of foreign inclusions on the order of at least 10 "to 10" ^ mol% based on the total silver halide of the grain.

The silver halide emulsions to be used in the manner according to the invention Ions are according to methods known per se for the preparation of silver halide emulsions with layered Grain structure produced »Double inlet processes are preferred while maintaining certain pAg and pH values applied. Emulsions with a layered grain structure and processes for their production are described in the German patent 1 169 290 or British patent specification 1 027 146 described. Reference is also made to the publication by E. MOISAR and S. WAGNER in "Reports of the Bunsen Society for physical chemistry "67 (1963), pp. 356-359, as well as P. CLAES and R. BERENDSEN in "Photographische Korrespondenz" 101 (1965), pp. 37-42. The ones to be stopped during the precipitation pAg values can be measured continuously electrometrically; the intake of the precipitation components is controlled by the measured value.

Both homodisperse and heterodisperse silver halide emulsions are suitable for the material according to the invention. Heterodisperse silver halide emulsions are understood as meaning emulsions with a broad grain size distribution, preferably at least 10, in particular at least 20% by weight of the silver halide grains having a diameter which deviates by at least 40% from the mean grain diameter.

The silver halide grains are essentially irregular Shape. The absolute value of the mean grain size can fluctuate within wide limits. Depending on the intended use of the photographic material can be both fine-grain heterodisperse silver halide emulsions with a mean Diameter of less than 0.5 / µm, preferably less than 0.3 / µm, as coarse-grained heterodisperse emulsions with mean grain sizes between 0.5 and 4 μm are also used «,

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529488

Also suitable for the inventive material are homodisperse silver halide emulsions with a narrow particle size distribution .. Preferably, about 95 wt .-% of the silver halide grains have a diameter which does not does not deviate more than 40%, or preferably more than 30% from the mean grain diameter.

The silver halide grains can be any of the known ones Have shapes, e.g. "cubic, octahedral or also the tetradecahedral Mixed form.

The absolute value of the mean grain size can fluctuate within wide limits. Depending on the intended use of the photographic material can be both fine-grain monodisperse silver halide emulsions with an average diameter of below 0.5 / µm, preferably below 0.3 / µm, as well coarse-grained monodisperse emulsions with mean grain sizes between 0.5 and 2 / µm are used »

As a protective colloid or binder for the silver halide emulsion layer ₀ are the usual hydrophilic film-forming agents are suitable, "B z. Proteins, in particular gelatin, alginic acid or their derivatives such as esters, amides or salts, cellulose derivatives such as carboxymethyl cellulose and cellulose sulfates, starch or their derivatives or hydrophilic synthetic binders such as polyvinyl alcohol, partially saponified polyvinyl acetate, polyvinylpyrrolidone and others. In a mixture with the hydrophilic binders, the layers can also contain other synthetic binders in dissolved or dispersed form, such as homopolymers or copolymers of acrylic or methacrylic acid or their derivatives such as esters, amides or nitriles, and also vinyl polymers such as vinyl esters or vinyl ethers _{or the like}

The silver halide emulsions to be used in the manner according to the invention can contain the usual emulsion additives, whereby it is only necessary to ensure that the surface sensitivity is kept as low as possible o

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The emulsions can also be spectrally sensitized. For example, the usual mono- or polymethine dyes, such as acidic or basic cyanines, hemicyanines, streptocyanines, merocyanines, oxonols, hemioxonols, styryl dyes or other, also trinuclear or polymethine dyes, for example rhodacyanines or neocyanines _o Such sensitizers are described, for example, in the Work by F ₀ M ₀ HAMER "The Cyanine Dyes and Related Compounds" (1964), Interscience Publishers John Wiley and Sons.

In addition to the compounds of the present invention, the emulsions can optionally contain the customary stabilizers, such as homopolar or salt-like compounds of mercury with aromatic or heterocyclic rings, such as Mercaptotriazoles, simple mercury salts, sulfonium mercury double salts and other mercury compounds. Azaindenes are also suitable as stabilizers, preferably Tetra- or Pentaazaindenes, especially those with HydroxyI- or amino groups are substituted. Such compounds are described in the article by Birr, Z. Wiss. Phot. 47, 2 to 58 (1952). Other suitable stabilizers include heterocyclic mercapto compounds, e.g. phenyl mercaptotetrazole, quaternary benzothiazole derivatives, benzotriazole and the like. These Stabilizers are generally used in very small amounts, i.e. in amounts that are about a power of ten or more are smaller than the amount of the compound according to the present invention. They do not serve to suppress the development fog, but to stabilize the emulsion against storage fog before the imagewise exposure. Reference is made here to DT-OS 2 416 814.

The emulsions can be hardened in the usual way, for example with formaldehyde or halogen-substituted aldehydes that contain a carboxyl group, such as mucobromic acid, diketones, Methanesulfonic acid esters, dialdehydes, carbodiimides, carbamoylpyridinium salts and carbamoyloxypyridinium salts.

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The selective obfuscation of the imagewise exposed, unveiled Direct positive emulsions can be treated with a fogging agent before or during processing be made. Suitable fogging agents are reducing agents such as hydrazine or substituted hydrazines. Referred see, for example, U.S. 3,227,552.

By "assignment" and "assigned" is meant that the mutual arrangement of silver halide emulsions and not diffusing connection is of such a nature that an interaction between them is possible, which is a pictorial correspondence between the formed silver image and image-wise distribution of the released, diffusing dye allows. In this case, the assigned coloring compound is expediently converted into a layer adjacent to the silver halide emulsion layer Layer embedded, this adjacent layer preferably (viewed in the direction of the incident upon exposure Light) is behind the silver halide emulsion layer.

The non-diffusing, coloring compounds must be a residue of a preformed dye or a dye precursor, e.g. contain a coupler which is set free as a result of development as a diffusing dye and then is able to diffuse into an image receiving layer which is in contact with the photosensitive Element constituting the photosensitive silver halide emulsion layers and contains the coloring layers. The coloring compounds therefore usually contain one Dye residue and a diffusion-proofing residue that are together are linked by certain atom groupings, whereby this link can be broken as a result of the development. Such non-diffusing, coloring compounds with a pre-formed dye component have already been described variously been. They are not mentioned, for example

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diffusing color couplers from DT-OS 1 095 115, insofar as they contain a preformed dye part, furthermore the hydrazone compounds of DT-OS 1 930 215 and the hydrazine compounds of DT-OS 2 228 361 / insofar as the latter is non-diffusing compounds / furthermore the coloring compounds from DT-OS 1 772 929, DT-OS 2 242 762, DT-OS 2 406 664 and German patent application P 25 05 248.6. The dye can also only be formed during development. Reference is made to DT-PS 1 095 115 in this regard. The remainders of dye precursor compounds, for example of color couplers, are also referred to below as dye residues.

In principle, the residues of dyes of all dye classes are suitable as dye residues, provided they are sufficiently diffusible to be able to diffuse through the layers of the light-sensitive material into the image-receiving layer. Because of this requirement, the dye residues are preferably provided with one or more water-solubilizing groups. Suitable water-solubilizing groups include: carboxyl groups, sulfo groups and aliphatic or phenolic hydroxyl groups. Examples of dyes which are particularly suitable for the process according to the invention are: azo dyes, azomethine dyes, anthraquinone dyes, phthalocyanine dyes, indigoid dyes and triphenylmethane dyes. The dye residue can already contain the number of solubilizing groups required for sufficient diffusion. Occasionally, however, it proves to be particularly favorable if, when the dye is released, an originally latently present, solubilizing group comes into operation, which remains with the dye residue and gives it an additional diffusibility. With regard to such an embodiment, reference is made, for example, to DT-OS 1 930 215 and DT-OS 2 406 664.

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The coloring compounds should not diffuse in the layers. For this purpose, they are provided with diffusion-proofing residues. These are preferably understood to mean organic radicals which in general can contain straight-chain or branched, aliphatic groups and optionally also carbocyclic or heterocyclic aromatic groups. The aliphatic part of these radicals generally contains 8 to 20 carbon atoms. These radicals are connected to the rest of the molecule either directly or indirectly, for example via one of the following groups: -0-, -S-, -CO-, -SO ₃ -, -NR-, -CONR- or -SO ₂ NR- , where R is hydrogen or alkyl.

For performing the dye diffusion transfer process in accordance with the present invention, a photosensitive element comprising the direct positive silver halide emulsion layers is used and the non-diffusing coloring compounds and an image receiving element in which by the image-wise transferred diffusing dyes the desired color image is produced. For this it is necessary that between the photosensitive element and the image receiving element a permanent contact at least for a finite period of time within the development period exists, so that the image-wise formed in the photosensitive member as a result of development Distribution of diffusing dyes can be transferred to the image receiving element. The contact can be made after development has started or it has already been made be »before development begins. The latter is, for example, the pail, if used to carry out the dye diffusion transfer process a material is used in which the photosensitive member and the image receiving member form an integral unit. the the present invention relates primarily to such

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Embodiments of the! Part »st off diffusion transfer process, in which such an integral unit, hereinafter also referred to as mono-sheet material, also continue to exist after the end of the development process remain; i.e., a separation of the photosensitive member from the image receiving element is not provided even after the Parb transfer has taken place. Such an embodiment is described, for example, in DT-OS 2 019 430. A particular problem with such monosheet materials consists in the fact that, as already mentioned, all the substances required for development are inside the material must remain and be rendered harmless there. Above all, the high level required for development should also be pH value, which persists for some time after development, does not result in the direct positive silver halide emulsion layer a veil of development arises. With the help of the compounds used according to the invention, colored Transfer images produced, which are significantly improved in terms of the image whites.

One for performing the dye diffusion transfer process Photosensitive material suitable according to the present invention has, for example, the following layer elements:

1) a transparent substrate

2) an image receiving layer

3) an opaque layer

4) a photosensitive element with at least one light-sensitive unfogged direct positive silver halide emulsion layer and at least one non-diffusing coloring compound

5) a delay layer

6) an acidic polymer layer

7) a transparent substrate

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The monosheet material can be produced in such a way that that two different parts are produced separately from one another, namely the light-sensitive part (layer elements 1 to 4) and the cover sheet (layer elements 5 to 7), which are then placed on top of each other and connected to one another, optionally using spacer strips, so that a space for receiving a precisely measured amount of a working fluid is formed between the two parts. the Layer elements 5 and 6, which together form the neutralization system, can also be used additionally or alternatively, but in be arranged reversed order between the support and the image receiving layer of the photosensitive member.

Means are provided for a working fluid between insert the photosensitive part and the cover sheet, e.g. in the form of a laterally arranged, splittable container, which, when subjected to mechanical forces, pours its contents between two adjacent layers of the mono-sheet material.

A substantial part of the photosensitive material according to the The present invention is the photosensitive element which, in the case of a monochrome transfer process, is a photosensitive, direct positive silver halide emulsion layer and, associated with this, a color-imparting combination of non-diffusing contains coloring compound. It cannot do this diffusing coloring compound in a to the silver halide emulsion layer adjacent layer or in the silver halide emulsion layer themselves are located, in the latter case the color of the image dye is preferably selected so that the predominant absorption range of the coloring compound does not correspond to the predominant sensitivity range the silver halide emulsion layer.

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For the production of multicolored transfer images in lifelike However, the photosensitive element has three such colors Allocation of coloring compound and unveiled one direct positive silver halide emulsion layer, usually the absorption range of the coloring compound with the Spectral sensitivity range of the associated silver halide emulsion layer will essentially match. A prerequisite for the highest possible sensitivity is then however, that each of the coloring compounds in a separate Binder layer (viewed in the direction of the incident light during exposure) behind the silver halide emulsion layer is arranged.

Those resulting from the development of a silver halide emulsion Oxidation products of the developer compound may of course only have an effect on the assigned coloring layer. Separating layers are therefore generally present in the photosensitive element which prevent the diffusion of the developer oxidation products effectively prevent developer connections to other unassigned layers. These separators may e.g. contain suitable substances that react with the developer oxidation products, for example not diffusing hydroquinone derivatives, or if the developing agent is a color developing agent, not diffusing color couplers. Also, if the coloring compounds have a preformed dye component, they cannot diffusing developer compounds assigned to the non diffusing coloring compounds be incorporated into the layers of the photosensitive element; the development is then expediently carried out in the presence of diffusing auxiliary developer compounds with an alkaline processing liquid. Such an embodiment is for example described in more detail in DT-OS 2 335 175. Here, too, separating layers can be present to prevent the diffusion of to effectively prevent oxidized auxiliary developer in unassigned layers.

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The photosensitive element has in one of its possible embodiments For example, the following structure (from top to bottom, i.e. in the direction of the incident during exposure Light):

Blue-sensitive unveiled direct positive silver halogenidemulsionsschicht _r

Layer with a non-diffusing compound that emits a yellow dye

Separating layer

Green sensitized, non-fogged direct positive silver halide emulsion layer

Layer with a non-diffusing compound that donates a purple dye

Separating layer

Red sensitized, non-fogged direct positive silver halide emulsion layer

Layer with a non-diffusing compound that emits a cyan dye.

Of course, the silver halide emulsion layers can also be arranged in a different order, but if Images in natural colors are to be obtained, as are the assigned layers with the coloring compounds must be swapped so that the assignment is retained.

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The opaque one placed under the photosensitive element The layer is permeable to aqueous alkaline treatment solutions and thus to the diffusing dyes. It essentially has two functions. Firstly, it is used after the development in the originally photosensitive Element remaining image silver, as well as the color-giving compounds remaining as a color negative to cover, so that with when viewed through the transparent substrate of the photosensitive part, only the positive color transfer image is visible is. Secondly, it closes off the photosensitive element in a light-tight manner on the side of the image receiving layer (downwards). The latter is particularly important if the light-sensitive material is still in the form of a mono-sheet material after exposure brought into contact with the alkaline processing compound of the camera, then pulled out of the camera and outside of the Camera to be developed.

Layers with sufficient opacity, but more sufficient Permeability for diffusing dyes can, for example, with suspensions of inorganic or organic dark, preferably black pigments, for example, with suspensions of carbon black in suitable binders, e.g. in gelatin solutions. In general, 0.5 to 2 / U thick layers are sufficient, those in gelatine 10 to 90 wt .- ^ (based on the total Dry weight) of carbon black to ensure sufficient exclusion of light during development guarantee. The particle size of the pigments used is relatively uncritical as long as it is not essential to 0.5 / U exceed.

In addition to the black pigment layer, the opaque layer preferably also comprises an underlying layer white pigment layer. This has the task of cover the black layer and add a white

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to create an underground. All white pigments are suitable for this, provided that their opacity is sufficiently high if the layer is not too thick. For example, barium sulfate, oxides of zinc, titanium, silicon, aluminum and zirconium, as well as barium stearate or kaolin, may be mentioned. Titanium dioxide is preferred as the white pigment. Here too, the same information applies with regard to the binder, the concentration and the particle size as for the black pigments. The thickness of the white pigment layer can be varied depending on the desired whiteness of the substrate. Thicknesses between \ 5-15 / u are preferred.

Instead of the light-impermeable layer, means for producing such a light-impermeable layer can also be arranged in the light-sensitive material according to the present invention between the light-sensitive element and the image-receiving layer, for example in the form of a laterally arranged container with a working fluid containing an opacifier (pigment), which when exposed to mechanical forces pours its contents between the layers mentioned, so that such a pigment layer is formed there.

The image-receiving layer consists essentially of a binder, the dye mordant for fixing which contains diffusing dyes.

As a mordant for acidic dyes are preferably long-chain quaternary ammonium or phosphonium compounds or ternary sulphonium compounds serve., For example those as described in the American patents 3 271 147 and 3 271 148. Further Certain metal salts and their hydroxides, the acid with the dyestuffs form poorly soluble compounds, are used. The dye mordants are in the

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Receiving layer diapered in one of the usual hydrophilic binders, for example in gelatin, polyvinylpyrrolidone, completely or partially hydrolyzed cellulose esters and the like. Of course, some binders can also act as mordants, for example copolymers or polymer mixtures of vinyl alcohol and H-vinylpyrrolidone as described, for example, in DT-IS 1 130 284, and also those which are polymers of nitrogen-containing quaternary bases, for example polymers of H-methyl-2 vinylpyridine as described, for example in the American patent specification 2 484 430. Other useful mordanting binders guanylhydrazone derivatives are, for example, alkyl vinyl ketone such as described polymers Acylstyrol-in United States Patent specification 2,882,156 or Guanjlhydraeonderivat "rom such as described in the ST-OS 2 009 498. In general, however, other binders, for example gelatine, will be added to the last-mentioned binding agents.

All transparent support materials for the mono-sheet material according to the invention can be the usual transparent support materials used in photographic practice, for example films made from cellulose esters, polyethylene "nt # rephthal" t, -. Polycarbonate or other film-forming polymers, find thread.

To process the imagewise exposed color photographic mono-sheet material according to the invention, an alkaline working fluid is pressed at a suitable point between two layer elements of the mono-sheet material.

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The working fluid is a liquid, viscous or pasty alkaline substance that triggers the development of the exposed silver halide. That only Auxiliary developing agents required for the development of the silver halide may be contained in the processing composition be, but it is also possible to accommodate them in one or more layers of the material, for example in one or more layers of the photosensitive element * or in a special binder layer, for example on the cover sheet.

The working liquid can also contain other reagents such as stabilizers, antioxidants, lubricants, opacifying agents and Viscosity-increasing additives. As viscosity-increasing additives to the processing materials come, for example in embossed cellulose derivatives, for example carboxyalkyl celluloses, hydroxyethyl cellulose, starch, polyvinyl alcohol and the like.

With the help of the fogging agents present in the working liquid, during the development of the unfogged direct-positive silver halide emulsion layers on the surface of the imagewise exposed Silver halide grains imagewise creates a developable fog. Suitable obscurants are For example hydrazine derivatives as described in US Pat. No. 3,227,552} a particularly suitable fogging agent is acetylphenylhydrazine. Alternatively, the Fogging agents can also be incorporated in one or more layers of the monosheet material, e.g. Silver halide emulsion layers or in one Auxiliary layer on the cover sheet.

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609884/0941

In the case of the structure described on page 19, the working liquid preferably also contains an opacifying agent, for example a white pigment such as TiO ₂ and / or a dark, preferably black pigment such as carbon black. This has the advantage that the photosensitive element is withdrawn from direct exposure both from below through the opaque layer and from above through the pigment layer formed from the pigment of the working fluid between the photosensitive element and the cover sheet, so that the monosheet material after the imagewise exposure can be removed from the camera without fear of re-exposure. Another possibility to protect the photosensitive element against exposure from above is to laminate an opaque cover sheet to the transparent cover sheet, or if there is not one, to the top layer of the photosensitive element while still in the camera. Such an opaque cover sheet can consist, for example, of an opaque layer support such as paper or pigmented cellulose acetate film, to which, for example, a black pigment layer can also be applied to improve the opacity. Furthermore, this opaque cover sheet can contain binder layers in which auxiliary substances for development, such as concealing agents or auxiliary developers, are incorporated.

To avoid the image irregularities due to lateral exposure, the monosheet material a »between the photosensitive element and the opaque layer arranged frame mask of one hydrophobic diffusion-suppressing material, as described for example in DT-OS 2 228 665 is.

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The alkaline processing mass sets a relatively high pH value in the photosensitive material (about 11 to 14), which means that development and the imagewise dye diffusion is triggered. It It has been found that at this high pH the dyes and thus the images obtained are not particularly good are stable. It is therefore necessary that, after the development is completed, the material should be nearly neutral or is made weakly angry. This can be done in a known manner can be achieved in that the material additionally contains an acidic polymer layer, which only gradually becomes accessible to the alkaline processing compound in the course of development. Under an acidic polymer layer a binder layer is understood, the polymeric compounds with acid groups, preferably sulfo- or Contains carboxyl groups. These acidic groups react with the cations of the processing compound to form salts and thereby lower the pH of the compound. Of course, the polymeric compounds and thus the acidic groups in the layer mentioned are embedded in a diffusion-proof manner. The acidic polymers are often derivatives of cellulose or derivatives of polyvinyl compounds but other polymeric compounds can also be used. Suitable acidic polymers are for example mentioned: cellulose derivatives with free carboxyl groups, e.g. cellulose dicarboxylic acid half esters with free carboxyl group such as cellulose acetate hydrogen phthalate, Cellulose acetate hydrogen glutarate, ethyl cellulose acetate hydrogen succinate, cellulose acetate hydrogen succinate hydrogen phthalate, ethers and esters of cellulose, which are combined with further Dicarboxylic acid anhydrides or with sulfonic acid anhydrides, modified for example with o-sulfobenaoic anhydride

AG 1359 - 30 "

609884/0941

are, carboxymethyl cellulose, also polystyrene sulfonic acid, polyvinyl hydrogen phthalate, polyvinyl acetate hydrogen phthalate, polyacrylic acid, acetals τοη polyvinyl alcohol alt aldehydes which are substituted by carboxy or sulfo groups, such as o-, m- or p-benzaldehyde sulfonic acid or carboxylic acid, partially etherified ethyl a-maleiJ ** ate anhydride copolymers, partially esterified methyl vinyl ether-maleic anhydride copolymers and the like.

This acidic polymer layer must contain enough acid groups in order to lower the pH value of the processing compound from beginning to 14 to such an extent that the material at the end is adjusted to be almost neutral or slightly acidic (pH value 5 to 8).

The time lag of the. Lowering the pH is achieved in a known manner in that the acidic polymer layer is provided with a so-called retardation layer is covered. This retardation layer is an alkali-permeable layer, which is preferably made of a polymer inert to alkali, for example made of polyvinyl alcohol or a partially acetalized one Polyvinyl alcohol is made. By suitable choice of the thickness and the composition of this retardation layer can the time lag of the lowering of the pH value in the desired way.

Neutralization systems, including lombi »a * ionenr» as bucket acidic polymer layer and a retardation layer are described in, for example DT-PS 1 285 310. Such layer combinations

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can be present in the material according to the invention, for example in the photosensitive part between the transparent support and the image-receiving layer. Another option is to use the To arrange neutralization system from an acidic polymer layer and a retardation layer on the cover sheet. Of course, these two layers must be arranged in such an order that the The alkali of the processing compound must first penetrate the retardation layer in order to get into the acidic polymer layer to get.

The dye diffusion transfer material of the present invention is advantageously exposed in or by means of a suitable self-development camera. This can be done e.g. with devices be provided, which make it possible after the exposure of the photosensitive element between this and to distribute a working solution on the cover sheet and to cover the light-sensitive material opaque to the top. Preferably Such a camera is provided with two nip rollers mounted against one another, between which the mono-sheet material is pulled out, splitting the laterally arranged containers and their contents between the layers of monosheet material dismiss.

As the photosensitive element after passing through the nip rollers is protected on both sides by opaque layers against unwanted exposure, the exposed Material must be withdrawn from the camera immediately after development has started.

To process the imagewise exposed monosheet material, the photosensitive element is brought into contact with the aqueous alkaline working solution. In the presence of the fogging agent, the imagewise exposed, non-fogged direct-positive silver halide emulsion layers are developed, in

AG 1359 - 32 -

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Correspondence with the positive silver image formed in the process, an image-wise distribution of diffusing dyes the non-diffusing coloring compounds released and transferred to the image receiving layer.

AG 1359 - 33-

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Example 1 ^ H

A photosensitive element of a photographic material according to the invention was prepared by applying the following layers successively to a transparent support made of polyester film. The quantities given relate to 1 m in each case. The formulas of the compounds A, B, C and D can be found in the formula appendix at the end of the examples.

1) A pickling layer made of 3.6 g of octadecyltrimethylammonium methyl sulfate and 9.0 g gelatin.

2) A reflective layer made of 48 g of TiO and 4.8 g of gelatine.

3) An intermediate gelatin layer composed of 2.5 g of gelatin and 82 mg of compound 1.

4) A dye layer of 1.2 g of the one cyan dye releasing compound A, 0.6 g of diffusion-resistant color developer D and 2 g of gelatin.

5) A red sensitized emulsion layer with an unveiled one direct positive working silver chlorobromide emulsion and 2 mg of the stabilizer 1- (3'-carboxyphenyl) -5-mercapto-tetrazo1, Silver application 2 g, gelatin application 0.6 g.

6) A protective layer of 2.6 g gelatin.

For comparison, the structure was repeated, but with the difference that layer 3 did not contain a compound according to the present invention.

A strip of each of the two photosensitive materials was exposed through a step wedge. After attaching a breakable At one end, the strips were layered

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sides covered with a cover film over two laterally attached spacer strips of 180 αϊ thickness. The so educated The image set was passed through a pair of nip rollers, with the developer paste between the photosensitive element and the cover sheet distributed. The developer paste had the following composition:

25 g of potassium hydroxide

5 g of N / N, N ¹ , N'-tetramethyl-p-phenylenediamine

1 g acetylphenyl hydrazine

1 g paraformaldehyde

0.1 g benzotriazole

10 ml of benzyl alcohol

35 g Natrosol HHR 250 (hydroxyethyl cellulose) made up to 1000 ml with water.

After the development time had elapsed, the cover sheet was removed and the adhesive paste was removed from the picture element. A positive blue-green dye image was visible through the transparent support on the TiO _{2 layer as the image background.}

The results after a development time of 10 minutes and 30 minutes are summarized in Table 1.

Example 2

The procedure described in Example 1 was repeated with the exception that instead of layers 3 and 6, the following layers were applied became.

3) An intermediate gelatin layer of 2.5 g gelatin.

6) A gelatin layer composed of 2.5 g of gelatin and 40 mg of the compound 1, emulsified in Ν, Ν-diethyllauric acid amide.

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2S29488

After the same processing as in Example 1, a positive blue-green dye image was obtained.

The results after a development time of 10 minutes and 30 minutes are shown in Table 1.

Table 1

(without
sentence) min 'max
after 10 min.
Development
Time min 'max
after 30 min.
Development
Time comparison 1) 0.47 / 1.46 1.38 / 1.70 example 2) 0.36 / 1.30 0.47 / 1.68 example 0.45 / 1.30 0.86 / 1.75

Example 3

On the same surface (transparent carrier, layers 1, 2), as described in example 1, the following layers were applied.

3) An intermediate gelatin layer composed of 2.7 g of gelatin and 85 mg of compound 1.

4) A dye layer composed of 0.7 g of the purple dye donating Compound B, 0.35 g of non-diffusing color developer D and 1.7 g of gelatin.

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5) A green sensitized emulsion layer with an unveiled one direct positive silver chlorobromide emulsion and 2 mg of the stabilizer 1- (3'-carboxyphenyl) -5-mercapto-tetrazole, Silver application 2.0 g, gelatin application 0.6 g.

6) A protective layer of 2.7 g gelatin.

The construction was repeated, but with the difference that layer 3 did not contain any compound according to the present invention.

After the same processing as in Example 1, a positive purple dye image was obtained.

The results after a development time of 10 minutes and 30 minutes are shown in Table 2.

Example 4

The procedure described in Example 3 was repeated with the exception that compound 1 was not included in layer 3, but was added to layer 6 in an amount of 22 mg. See table 2 for the results.

Table 2

(without min 'max
after 10 min.
Development
Time 2.04 min 'max
after 30 min.
Development
Time 90 / 2, 23 comparison sentence) 0.40 / 1, 2.02 51 / 2, 13th Example 3 0.29 / 2.03 0, , 38 / 2, 14th Example 4 0.28 / 0,

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_x 2S29488

Example 5 ^

On the same base as described in Example 1 (more transparent Carrier, layers 1, 2) the following layers were applied.

3) An intermediate gelatin layer of 2.5 g gelatin.

4) A dye layer of 1.8 g of the one cyan dye separating compound A, 0.7 g of the diffusion-resistant color developer D and 2.2 g gelatin.

5) A red sensitized emulsion layer with a non-fogged one direct positive silver chlorobromide emulsion and 2 mg of the stabilizer 1- (3 · -Carboxyphenyl) -5-mercapto-tetrazole, Silver application 2 g, gelatin application 0.6 g.

6) A barrier layer of 0.27 g of octadecyl hydroquinone sulfonic acid, 22 mg of Compound 1 and 2.7 g of gelatin.

7) A dye layer composed of 0.7 g of the purple dye-releasing agent Compound B, 0.35 g of non-diffusing color developer D and 1.7 g of gelatin.

8) A green sensitized emulsion layer with a non-fogged one direct positive working silver chlorobromide emulsion-and 2 mg of the stabilizer 1 - (3'-carboxyphenyl) -5-mercapto-tetrazole, Silver application 2 g, gelatin application 0.6 g.

9) A barrier layer of 0.27 g of octadecyl hydroquinone sulfonic acid, 22 mg of Compound 1 and 2.7 g of gelatin.

10) A dye layer composed of 1.3 g of the yellow dye-releasing agent Compound C, 0.8 g of non-diffusing color developer D and 2.6 g of gelatin.

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2S29488

11) A blue sensitized emulsion layer with a non-fogged one direct positive working silver chlorobromide emulsion and 2 mg of the stabilizer 1- (3'-carboxyphenyl) -5-mercapto-tetrazo1, Silver application 2 g, gelatin application 0.6 g.

12) A protective layer of 0.27 g of octadecylhydroquinone sulfonic acid, 22 mg of compound 1 and 2.7 g of gelatin.

The construction was repeated, but with the difference that layers 6, 9 and 12 do not have a connection according to the present invention contained.

A strip of each of the two photosensitive elements was exposed through a color separation wedge and then as in Example 1 described with a paste strength of 260 / u. developed. A positive multicolored image of the original was obtained.

The results after 10 minutes and 30 minutes of development are compiled in table 3.

Table 3

gb min max 10 min. / ■ # 72 ^D min / ° max / 2.21 PP after Development / 1.62 after 30 min. / 2.14 bg Time / 1 * 11 Development / 1.71 gb / 1.68 Time / 2.18 Comparison (without PP / 1.80 / 2.00 itt sentence) bg 0.41 / Ir 17 / 1.54 0.45 1.45 0.48 1.78 0.41 1.31 Example 5 0.41 0.50 0.42 0.51 0.52

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Example 6

Ι, ο

2B29488

The procedure described in Example 1 was repeated with the exception that compound 1 in layer 3 was replaced in each case by one of compounds 2 to 9. For comparison purposes, a structure without the addition of a compound according to the present invention was used. The results are summarized in Table 4.

Table 4

additive (no to
sentence) min 'max
after 10 min.
Development
Time min max
after 30 min.
Development
Time comparison 2 0.47 / 1.57 1.37 / 1.72 link 3 0.40 / 1.43 0.58 / 1.65 link 4th 0.45 / 1.37 0.60 / 1.69 link 5 0.41 / 1.44 0.61 / 1.81 link 6 · 0.42 / 1.36 0.73 / 1.69 link 7th 0.46 / 1.31 0.63 /. 1.59 link 8th 0.36 / 1.29 0.76 / 1.63 link 9 0.38 / 1.30 0.80 / 1.77 link 0.37 / 1.02 0.55 / 1.56

Example 7

The process described in Example 1 was repeated with the difference that layer 3 contained no additive and that instead of 15 mg of compounds 10 and 11 were incorporated into emulsion layer 5.

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A structure without an addition in the was used for comparison purposes Emulsion layer.

The results are shown in Table 5.

Table 5

Stabilizers min 'max
after 10 min.
Development
Time min max
after 30 min.
Development
Time Construction without
Stabilizer additive 0.53 / 1.64 1.78 / 2.03 Establishing with connection
10 0.38 / 1.28 0.54 / 1.69 Connection 11 0.52 / 1.47 0.65 / 1.99
i

The examples listed below were carried out with an emulsion / those with extended development times from home resulted from a lesser haze.

Example 8

The procedure described in Example 1 was repeated with the exception that instead of layer 1 in each case 65 mg of the compounds 12 to 17 were stored in layer 6. For comparison purposes a structure without the addition of a compound according to the present invention was used. The results are summarized in Table 6.

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2b29488

Table 6

additive min max
after 10 min.
Development time D. / D
mm max
after 30 min.
Development stage Comparison without
additive 0.41 / 1.33 1.03 / 1.82 12th 0.40 / 1.35 0.56 / 1.80 13th 0.38 / 1.36 0.60 / 1.79 14th 0.39 / 1.33 0.56 / 1.75 15th 0.37 / 1.21 0.60 / 1.68 16 0.37 / 1.20 0.47 / 1.82 17th 0.40 / 1.29 0.59 / 1.82

Examples 1 to 8 show that with the aid of the stabilizers according to the invention, with acceptable losses in color density, the fog values are markedly reduced with prolonged development times can be.

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OCH.

SO ₂ -NH-N = C

CH.

N SO ₃ H OC ₁₆ H ₃₃

NH OH

1-SO ₀ -NH-N = C

OCH ₃ ^0CH 3 _(ύΗ ,

S0, H ^S0 3 ^H I

SO ₃ H

^C 16 ^H 33

CH ₃ -NH-CO

" ^OC 16 ^H 33

OCH SO ₃ H

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2S29488

7 ~ N

CH.

^C 16 ^H 33

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Claims (4)

ksr Claims ; (i ) j Photosensitive material for the production of colored images by the color diffusion transfer process containing on a transparent support in the following order an image receiving layer, a light reflecting pigment layer and a photosensitive element with at least one photosensitive, non-fogged, direct positive silver halide emulsion layer and a non-diffusing coloring compound assigned to it, characterized that the photosensitive material contains in one or more of its layers agents which, when exposed to an alkaline processing liquid, provide i-aryl-5-mercaptotetrazole with a time delay in the photosensitive layer. 2) Material according to claim 1, characterized in that there is a compound of one of the layers in one or more of its layers contains the following formulas: for r r / ^N \ / ¹ K / ^N \ R-S-C N N C-S-CO-O-X-O-CO-S-C N β H Il | l |! Ii NNN ά _τΐ Ν N where mean R is hydrogen or a group that can be split off under the alkaline conditions of development, X is an alkylene group which is optionally interrupted by oxygen (-0-) Ar is a phenyl group with at least one free o-position, which, however, must have further substituents for R = hydrogen, the total molecular weight of which is between 50 and 120 and of which two adjacent ones can optionally form an annealed carbocyclic ring.
AG 1359 - 45 - 609884/0941 3) Material according to claim 2, characterized in that R is an acyl group which is derived from an aromatic Carboxylic acid, or a carbonic acid monoalkyl ester or an aliphatic or aromatic sulfonic acid. 4) Material according to claim 1, characterized in that it is in at least one non-photosensitive, to a non-veiled direct positive silver halide emulsion layer adjacent binder layer a compound of the following formula: Ar
I. H-S-C N fl Il N N wherein Ar is a substituted phenyl group with at least one free o-position, all of its substituents have a molecular weight between 50 and 120 and optionally two of which are adjacent to each other form a fused carbocyclic ring, in an amount of 0.005 to 0.5 mol per mol of silver halide in the silver halide photosensitive layer. AG 1359 - - 46 - 609884/0941