US3782948A

US3782948A - Photographic material containing nitro compounds for the silver dyestuff bleaching process

Info

Publication number: US3782948A
Application number: US00217654A
Authority: US
Inventors: H Schaller; A Froehlich; A Oetiker
Original assignee: Ciba Geigy AG
Current assignee: Ilford Imaging Switzerland GmbH
Priority date: 1968-04-09
Filing date: 1972-01-13
Publication date: 1974-01-01
Anticipated expiration: 1991-01-01
Also published as: FR2005820A1; DE1917813A1; CH507536A; BE731162A; GB1245345A

Abstract

AROMATIC OR HETEROCYCLIC NITRO COMPOUNDS AS OXIDIZING AGENTS FOR THE REDUCED DYESTUFF BLEACHING CATALYST IN PHOTOGRAPHIC MATERIAL FOR THE SILVER DYESTUFF BLEACHING PROCESS.

Description

United States Patent 3,782,948 PHOTOGRAPHIC MATERIAL CONTAINING NITRO COMPOUNDS FOR THE SILVER DYESTUFF BLEACHING PROCESS Alfred Froehlich, Marly-le-Grand, and Alfred Oetiker v, :lmdHeinrich,Schaller, Fribonrg, Switzerland, assignors to Ciba-Geigy AG, Basel, Switzerland No Drawing. Continuation-impart of abandoned applica- Ktion' Ser. No. 812,860, Apr. 2, 1969. This application Jan; 13, 1972; Ser. No. 217,654

priority, application Switzerland, Apr. 9, 1968, 5,236/68 a Int. Cl. G03c 1/76 U.S.Cl. 96-73- 11 Claims ABSTRACT OF THE DISCLOSURE Aromatic or heterocyclic nitro compounds as oxidizing agents for the reduceddyestuffbleaching catalyst in photographic. material for the silver dyestufi bleaching process.

Thisapplication is a continuation-inpart of our copending application Ser. No. 812,860, filed Apr. 2, 1969, now abandoned. The present invention provides a photographic material for the s'iIver-dyestuff bleaching process said material consisting of different layers and containing in at least one silver halide layer an azo dye that can be bleached by silver which material contains in at least one of said layers a colorless or faintly colored nitro compound of the formula in which A represents an aromatic or heterocyclic residue consisting of one or two rings each containing 5 or 6 ring members; B represents an organic residue containing at least 8 members; D and E each represents an acid water-solubilizing group; m, n and p each represents 1, 2 or 3, and q and r each represents an integer of at least one. The residue B is, for example, an at least 8-membered carbon chain which may contain hetero atoms.

Particularly valuable nitro compounds are those of the in which A represents a benzene, naphthalene, diphenyl, pyridine, quinoline or phenylpyrazolone residue; 13,, represents an organic residue which contains one or two aliphatic chains consisting of carbon atoms and, if desired, oxygen and/or nitrogen atoms, these chains containing a total of at least twelve members; D and E each represents a sulphonic or carboxylic acid group; 11,, m p and r each represents 1 or 2, and q ==1, 2 or 3.

3,782,948 Patented Jan. 1, 1974 ice Expressed in a simplified manner, the nitro compounds of Formula 3 constitute compounds of one of the following 3 types:

Particularly suitable are nitro compounds of the in which B D E m n p q, and r have the above meanings and A represents a benzene or naphthalene residue.

Of special value are nitro compounds of the formula in which A D E m 11 p q and r have the above meanings and B represents a residue which contains at least one aliphatic chain consisting of carbon atoms and, if desired, oxygen and/or nitrogen atoms, of at least twelve members in all, which residue is linked with the residue A directly or through an NR-CO-, ---CONR---, O- or NR-- bridge, where R represents a hydrogen atom or a lower alkyl group.

Among these nitro compounds those of formula (\NOm (m -l] (l -n+1 are preferred; in this formula A D E m n p q and r have the above meanings and B represents a residue which contains at least one aliphatic chain consisting of carbon atoms and, if desired, oxygen and/or nitrogen atoms, of at least twelve members, which residue is linked with A directly or through an 0 or an NRC-0- bridge, where R represents a hydrogen atom or a lower alkyl group.

In the first place nitro compounds of the formula ilp-a (\NOm (a ea -n+1 (m -1) (r-ll +1 in which A2, B4, D1, E1, "'11, n p q] and r1 have the above meanings, are preferably used.

Among the nitro compounds of the Formula 7 those are especially valuable which correspond to the formula NH-C o-o O2N D1 in which G represents a residue of the formula xHZxft or C H COO'H (where x is a digit of from 11 to 17 and y a digit of from 14 to 20) and D represents a sulphonic or carboxylic acid group.

The compounds of the Formulae 1 to 8 can be readily manufactured by known methods, for example by reacting an acid chloride, for instance stearoyl chloride, lauroyl chloride, sebacinoyl chloride, abiethinoyl chlo ride, or an acid anhydride for instance dodecenyl'suo cinic anhydride, with the corresponding aminonitro compounds, or by reacting aromatic nitro compounds containing a replaceable halogen atom, for example 4-nitrochlorobenzene-Z-sulphonic acid, with a difiusioninhibiting amine or enol, for example 1,12-diaminm dodecane, N-methyloctadecylamine, pentaor tetra-ethyleneglycol or polyethylene-imine, or by reacting aromatic nitro-isocyanates, for example 3-nitro-phenylisocyanate or 3nitrophenyl-sulphonylisocyanate, with a dilfusionresistant amine or enol. These processes are merely given by way of examples and certainly do not exhaust all the possible methods of manufacture.

The residue A in the Formula 1 preferably represents an aromatic residue consisting of one or two rings, for example a benzene or naphthalene residue or a heterocyclic residue consisting of one or two rings, for example a pyridine or quinoline ring; or A may also represent an aromatic-heterocyclic system, for example a phenylpyrazolone residue. The residue A contains one or two nitro groups and may also be substituted by one or two acid water-solubilizing groups, for example sulphonic or carboxylic acid groups. Furthermore, the residue A may be linked with the residue B either directly or through a bridge member.

B as diffusion-inhibiting group may be bound to group A directly or through a bridge member, e.g. S,

where R is hydrogen or an alkyl group having at most 5 carbon atoms.

As diffusion-inhibiting groups B are suitable, for instance, linear or branched, saturated or unsaturated substituted or unsubstituted hydrocarbon radicals which when substituted contain (a) nitrogen, oxygen or nitrogen and oxygen atoms, as substituents or chain members, (b) carbocyclic nuclei and (c) carbocyclic nuclei and nitrogen, oxygen or nitrogen and oxygen as substituents or chain members, said diffusion-inhibiting group containing at least 8 members. The actual difiusion-inhibiting residue within the residue B may also be linked with an aromatic or heterocyclic ring, for example with a. benzene ring. This ring may, if desired, contain several such diifusion-inhibiting residues, in which case the residue B is advantageously linked with A by a bond starting from the ring.

Diffusion-inhibiting residues which represent the residue B itself or only a part thereof are, for example, alkyl, e.g. dodecyl, alkylamino, e.g. dodecylamino, alkanoyl, e.g. pentanoyl, capryl, lauroyl, stearoyl; phenylcarbamoylalkylenecarbonyl; alkylphenoxymethylene; alkanoylaminophenylcarbamoylanilide, alkanoylphenylcarbamoyl; phenoxypolyethyleneoxyalkylene; alkylpyrazolone; N- alkylated-aminophenyl; aliphatic carbocyclic having up to 19 carbon atoms e.g. 1methyl-7-isopropylphenanthr- 1-yl; benzamidodiphenylamino optionally substituted in the diphenyl moiety by lower alkoxy, phenylcarbamoyloxy-polyethyleneoxy-carbonyl and anilinoalkylene having up to carbon atoms in the alkylene moiety.

The acid water-solubilizing groups D and E are linked with A or B; it is possible that both A and B, or only A, or only B or neither A nor B contain such groups. D and E preferably represent sulphonic or canboxylic acid groups. An acid group linked with B is formed, for example, by using an alkylene-substituted succinic anhydride or a sulphonatable unsaturated aliphatic compound, for example oleic acid, as acylating agent for A. When the residue B represents, for example, a tetraor pentaethylene glycol residue or a polyvinyl alcohol residue, the introduction of acid water-solubilizing groups into the molecule of the nitro compound may be dispensed with without sacrificing the solubility in water. The compounds of the Formula 1 may also be insoluble in water; such nitro compounds may also be soluble in a sparingly volatile organic solvent, for example in tricresyl phosphate or dibutyl phthalate.

The atomic grouping of the formula (\Nom t in which A, D, n, p and r have the above meanings may appear in the molecule once or twice, depending on the number of the bond-forming groups in B. For example, tetraor pentaethylene glycol combine through their hydroxyl groups with two residues of the Formula 9, as do diamines, for example diaminodecane, or dicarboxylic acids, for example sebacic acid, while polyvalent residues B, for example polyvinyl alcohol, maleic anhydride copolymers or carbohydrates are capable of combining with several residues of the Formula 9; in. the case of the maleic anhydride copolymers the number of the liberated canboxyl groups in the ester or amide-like compound comprising the residue of the Formula 9 depends on the polymer and on the degree of conversion reached.

The residue of the Formula 9 may also be linked With the diffusion-inhibiting residue through so-called reactive compounds, for example cyanuric chloride, dichloropyrimidine, B-chloropropionyl chloride, dichloroquinoxaline carboxylic acid chloride or the like. Apart-from the difiusion-inhibiting residues already mentioned watersoluble polymers miscible with gelatin are suitable above all, or under certain conditions even gelatin itself.

A few examples of nitro compounds of Formula 1 are the following compounds of the Formulae I to XXXI:

His

02N- NEG-CO-CnHu (II) can OzN- NIH-C OCHgC HC 15H OaH (III) -NH-C O-CHz-C HC12H28 O OH zN (IV) 10 on p p o aNO-NH-C Q-CH2 0 131-0 n coon v NH-CO-CHz-CH-OrzE: 3 0 OH V om NHCO--CHz-CH-Cr2Hz;

l to...-

(VI) SOaH (XXXI) C 11 Specially suitable nitro compounds are those of the Formulae I, XXIX, XXX and XXXI.

In addition to these monomers, polymers may also be mentioned, for example the reaction product of polyvinyl alcohol with 3-nitrophenylisocyanate or the reaction product of a vinyl alcohol/maleic anhydride copolymer with 1-amino-3-nitrobenzene.

The nitro compounds of the Formula 1 are substantially colorless and as a rue soluble as such or in the form of their alkali metal salts in water or in a mixture of water and an organic solvent, preferably methanol. When introduced into gelatine, they dry together with it and are then glass clear, even when they are dispersed in the gelatine. Water-insoluble nitro compounds may be dissolved in a sparingly volatile organic solvent and then finely dispersed in the gelatine.

In a multi-layer material the nitro compounds of Formula 1 may be added to all the layers or only to some of the emulsion, dye, emulsion dye, intermediate or auxiliary layers according to the desired effect. In the case of mixed grain emulsions the nitro compounds may be introduced into the disperse phase and/or the binder layer which serves as a matrix. The term intermediate layers comprises especially the separating layers, while the auxiliary layers are lubricating layers, protective layers, filter layers, antihalation layers, or coatings, substrations and baryta layers.

It is a special advantage of the compounds of the Formula I that owing to their diffusion stability they remain in the layers to which they have been added and neither migrate into the baths nor exert an undesirable influence on adjacent layers. Their diffusion stability also prevents migration within the layer so that the nitro compound can only act in the area where it is present.

When the nitro compounds of the Formula 1 are used in the intermediate layers, the application of a bleaching catalyst improves the quality of the image. As is known, the bleaching catalysts used in a bleaching process with metallic silver are reduced to hydro compounds which then undergo reoxidation and cause the bleaching of the dye. The reduced form, provided it does not act immediately in the bleaching process, migrates into the adjacent layers where it produces an undesired and harmful bleaching of the image dye. The nitro compounds in the intermediate layers prevent this harmful effect by oxidizing the reduced catalyst migrating from the layer.

Owing to their diffusion stability these nitro compounds can be added in different concentrations to the individual layers of a multi-layer material, especially to those which contain the image dye, with a view to influencing the sensitometric properties of the image-forming layers individually and thereby improving the physical properties of the image in the multi-layers.

The nitro compounds of the Formula 1, especially those which contain two nitro groups (m=2) in the residue A, are specially suitable for this purpose because of their high oxidation potential. Since one nitro group is equivalent to six hydrogen atoms, a smaller quantity of the nitro compound of the Formula 1 will be needed than, for example, of a quinone, a nitroso compound or an azo dye, which correspond to two, or at most to four hydrogen atoms. For example:

The absence of color in many of the nitro compounds of Formula 1 is especially important for use in opaque color prints in viewing which the dye is particularly sensitive even to a slight yellow cast.

For example, a 0.02-molar aqueous quinone solution has at 420 nm. an absorption maximum of 0.76 density, whereas the compound of the Formula I, that is 2-stear0ylamino-6-nitrotoluene-4-sulphonic acid, in the same concentration shows no absorption in the visible region. In contrast to quinones and nitroso compounds these nitro compounds are stable and are not affected by the action of light. For example, the initially pale yellow solution of quinone in gelatine, prepared by adding 20 ml. of a methanolic 0.1-molar solution to ml. of 3.75% gelatine solution, turns brownish red when exposed to daylight for a short time, whereas a similarly prepared solution of the compound of the Formula I remains colorless. When 10 ml. each of these gelatine solutions are cast over a glass plate measuring 13 x 18 cm., the compound of the Formula 1 forms a colorless layer, as against a reddish layer with quinone, which does not .lose its color even when rinsed in water. In contrast to the quinones the nitro compounds do not react with the developers under the usual developing conditions, for example with hydroquinone. I

The diflusion-resistant and soluble nitro compounds are easy and cheap to manufacture.

The nitro compounds of the Formula 1 offer special advantages when used as additives to separating, filter or antihalation layers that contain colloidal silver or a fogged silver halide emulsion. 1

In the past such layers could not be used in materials for the silver dye bleaching process because during the bleaching process silver converts the dye bleaching catalyst into a reduced form which then migrates into the adjacent layers where it bleaches the dyes in unexposed, that is silver-free areas. When one of the nitro compounds of the Formula 1 is added to the filter or antihalation layers, and the colloidal silver or the silver formed during the developing from the pre-exposed silver halide is bleached, either the catalyst is not reduced or the activated catalyst produced is immediately reoxidized and cannot produce any undesirable dye bleaching in the adjacent layers.

It is not a disadvantage when an excess of a nitro compound of Formula 1 is incorporated with the layers, especially the auxiliary layers. t

By using the nitro compounds of the Formula 1 in protective or cover layers the enrichment of the reduced form of the dye bleaching catalyst in the corresponding bath can be prevented, whereas otherwise-the catalyst concentration is diflicult to keep constant.

When the nitro compounds of the Formula'l are added to dyed layers, the nitro compounds compete with the dye during the bleaching process, whereby in general a flatter gradation in the dyed layer is produced.

. 9 .MANUFACTURING INSTRUCTIONS :10 grams of 2-amino-6-nitrotoluene-4-sulphonic acid are dissolved in 100 ml. of pyridine and 12.5 g. of stearoyl chloride rare stirred in di opwise at the boil; the dropwise addition of stearo'yl chloride is continued until no more aminotnitrotoluene sulphonic acid can be identified by a diazotization and coupling test. The pyridine is then distilled on a steam bath under vacuum and the residue is triturated with 100 ml. of acetone, suction filtered and the residue washed with acetone. After recrystallization from alcohol with 1 g. of active carbon 18 g. of Z-nitro- 6-stearoylaminotoluene-4-sulphonic acid are obtained of the Formula I, melting at 193 to 199 C.

24.8 g. of l-nitro-methoxy 4 aminobenzene-6-sulphonic acid are suspended in 1150 ml. of pyridine and 35 ml. of stearoyl chloride are slowly stirred in at the boil. The addition of stearoyl chloride is continued until free amine can no longer be identified by a diazotization and coupling reaction. The pyridine is distilled under vacuum on a steam bath and the residue is boiled with 300 ml. of acetone. It dissolves completely. Then 10 g. of active carbon are added and the batch is suction filtered hot and the mother liquor kept for 3 hours at -10 C. It is again suction filtered and washed three times with 20 ml. of acetone cooled to C. on each occasion. After recrystallization from alcohol 39 g. of colorless crystals are obtained melting at 171 C., which consist of the pyridine salt of 1-methoxy-3-nitro-6-stearoylaminobenzene-4sulphonic acid of the Formula XXIX.

216 g. of sodium Z-chloro-S-nitrobenzene sulphonate are dissolved in 520 ml. of water, then 226 g. of methyloctadecylamine, 1200 mlLof isopropanol and 100 g. of

sodium bicarbonate are added and the whole is boiled for of glacial acetic acid and 55 ml. of water are refluxed and stirred for 6 hours, mixed with 4000 ml. of alcohol and 300 g. of finely powdered -nitro-2-methyl-octadecylaminobenzene sulphonic acid are introduced within 2 hours. The batch is boiled for another 24 hours and then potassium carbonate is added until an alkaline reaction to phenol phthalein has been attained, suction filtered hot and the residue washed with 2000 ml. of boiling ethanol on each occasion. After cooling to room temperature the batch is suction filtered and the residue washed with 300 m1. of ethanol and thoroughly pressed. The product is taken off the suction filter without drying, dissolved in 150 ml. of glacial acetic acid, mixed with 30 g. of carbon, heated to theboil and suction filtered hot. The filtrate is mixed with 1000 ml. of water at the boil and then cooled to C.; the'precipitated crystals are suction filteredand'washedwith 1000 ml. of water. Another recrystallizationfrom 1000 ml. of ethanol yields 200 g. of colorless crystals of 4-methyl-octadecylamino-3-aminobenzene sulphonieacidmelting at 181 C. 25 g. of this substance i11-150 ml.;of diethylaniline are heated to 100 C and then mixed with 15 g. of 3,5-dinitrobenzoyl chloride. More dinitrobenzoyl chloride is added until no more amine can be identified in the reaction mixture by diazotization. The reaction solution is stirred into 100 ml. of ether. The productyis at firstsmeary, but it crystallizes 10 on prolonged standing. It is suction filtered, rinsed with 100 ml. of ether and the residue is recrystallized from 1000 ml. of methanol. Yield: 20 g. of colorless powder melting at 150 C.

15 g. of this substance are suspended in 100 ml. of water at C. and mixed with 22 ml. of 2 N sodium carbonate solution. The clear solution obtained is mixed at 60 C. with 20 ml. of 2 N sodium carbonate solution, whereupon the sodium salt is obtained as a yellow powder, which is cooled to 5 C., suction filtered and the residue rinsed with 500 ml. of ice water. Yield: 12 g. of the compound of the Formula XXX. The compound of the Formula XXXiI is obtained in a similar manner.

Example 1 Two glass plates A and B, each measuring 13 x 18 cm., are coated with a dye gelatine solution of the following composition: 3.3 ml. of 6% gelatine solution, 2.0 ml. of 1,3-dichlorotriazine 5 aminobenzene-4-sulphonic acid (1% solution), 0.5 ml. of a 1% solution of the dye of the formula @011 S OaH 4.2 ml. of water.

Plate A is coated with a solution of 5.0 ml. of 10% gelatin, 1.0 ml. of 1% colloidal silver solution, 5.0 ml. of water and 2.0 ml. of 1,3-dichlorotriazine-S-aminobenzene-4'-sulphonic acid (1% solution) and plate B with a solution at 5.0 ml. of 10% gelatin, 1.0 ml. of colloidal silver solution (1% 5 .0 m1. of water, 0.125 g. of Z-nitro- 6-stearoylaminotoluene-4-sulphonic acid, 2.0 m1. of 1,3- dichlorotriazine-S-aminobenzene-4'-sulphonic acid (1% Each plate A and B is halved so that 4 plates, A A B and B are obtained.

From plates A and E the metallic silver is oxidized with the following bleaching bath: 150 ml. of 37% hydrochloric acid, 25 g. of copper sulphate, 30 g. of potassium bromide, made up with water to 1 litre.

The plates A and B are subjected to the usual dye bleaching process as follows:

They are immersed for 1 minute in a dye bleaching bath composed of: ml. of 37% hydrochloric acid, g. of potassium bromide, 8 g. of thiourea, 1 ml. of 2,5-dimethylpyrazine, made up with water to 1 litre, then rinsed in water for 2 minutes, fixed in a solution of 150 g. of sodium thiosulphate, 15 g. of sodium sulphite, 13.5 ml. of 100% acetic acid, 15 g. of sodium metaborate and 15 g. of potassium aluminium sulphate, made up with water to 1 litre, and then rinsed in water for 10 minutes.

The transparency of the residual magenta layer is measured with a spectrophotometer. The resulting values Example 2 As described in Example 1 a 7% gelatin solution is mixed at 40 C. with a solution of a cyan image dye of the formula QC O-HN-Q and the usual casting additives for example a wetting agent, hardener and glycerine. By adding the requisite quantity of water the viscosity is then adjusted to the desired value. A layer 5n thick (in the dry state) is then produced on a photographic layer base at a casting temperature of 40 C. and a casting rate of 6 meters per minute.

One half of this dyed gelatine layer is covered with a gelatine interlay 2,14 thick; in addition to the wetting agent and the hardener this layer contains no further additives. The other half of the dyed gelatine layer is covered with a gelatine interlay 2n thick, which contains the same additives and also in addition 16.7% (referred to gelatine) of the compound of the Formula I.

Both interlays are then covered in the known manner with a silver halide emulsion to produce a layer 5 thick in the dry state. The emulsion contains 7% of gelatine and 34 g. of silver per kg.

Both materials are exposed to incandescent light under a grey step wedge, developed in a bath containing l-methylamine-4-hydroxybenzene sulphate and hydroquinone to the same silver density and freed from silver halide in a bath containing sodium thiosulphate. After an intermediate rinsing in Water, the materials are treated for 8 minutes at 20 C. in a dye bleaching bath of the following composition:

Water ml 1000 Thiourea g 50 Sulfamic acid g 50 Dimethylpyrazine, 1% ml 4 The residual silver and residual silver salts are washed out in the known manner.

When the image density in the unexposed areas and in the areas of maximum exposure is measured behind red filters, the following values are obtained:

Maximum Minimum density density Experiment with nitro compound 1. 91 1. 4 Experiment without nitro compound 1. 88 0.1

These values show clearly that the presence of the nitro compound in the interlay results in a substantial reduction of the dye bleaching.

Example 3 12' 12 ml. of methanol containing 1.25 g. of Compound XXIX, and 1 ml. of hardener solution (plate A).

3.5 ml. of the same solution but without the compound of the Formula XXIX is poured over the other glass plate (plate B).

After drying, each plate is covered with a mixture of 1.65 ml. of 6% gelatine, 1 ml. of hardener and 0.29 ml. of a 1% aqueous solution of the dye of the formula son: on,

/N=N I l Nn-o 0 s o 0 03K OCH:

om sou:

0cm sour and 2.1 ml. of water.

A strip of each of these plates A and B is exposed under a grey step wedge for 3 seconds with 500 lux and then treated for (a) 10 minutes in the developer G. p-Methylaminophenol sulphate 1 Sodium sulphite, anhydrous 20 Hydroquinone 4 Sodium carbonate, anhydrous 10 Potassium bromide 2 Water to 1000 ml.

(b) 2 minutes washing (c) 6 minutes in the stop-fixing bath sodium thiosulphate cryst. g 200 Sodium sulphite, anhydrous g 15 Sodium acetate (3H O) g 25 Glacial acetic acid ml 13 Water to make 1 litre.

(d) 8 minutes rinsing in water (e) 20 minutes in a dye bleaching bath Potassium iodide g 20 Sodium hypophosphite, cryst. g 0.2 Sulphuric acid, 96% ml 55 Water ml 1945 Ethanolic solution containing 0.3 g. of 2,3-

dimethyl-6-aminoquinoxaline in 50 ml. of ethanol ml 30 (f) 4 minutes rinsing in water (g) 8 minutes in a silver bleaching bath G. Potassium ferricyanide '50 Potassium bromide l5 Disodium phosphate 10 Monosodium phosphate Water to make 1 litre. (h) 6 minutes rinsing in water (i) 6 minutes in a fixing bath (same composition as the stop-fixing bath), (j) 10 minutes rinsing in water.

The strip B reveals a yellow dye wedge, whereas strip A is of a uniform yellow color. When the dye density in the absorption maximum of the respective-dye 'inthe two strips is measured in the same area, i.e. where maximum exposure occurred, strip A reveals the relative value of 1.6 and strip B of 0.26, that is to say the reduced form of the catalyst diffusing from the" silver halide emulsion reaches the dye layer in strip B and produces a bleaching of the dye, whereas in strip A the compound of the'Formula XXIX which is present causes the reoxidation of the reducedcatalystwsozthat it: cannot react at all or only slightly in the dyed-layer.

When in these experiments the yellow dye of the Formula 12 is replaced by the cyatfdye of the formula a value of 1.29 is obtained for strip A and a value of 0.6 for strip B.

When less than 1.25 g. of theCompound XXIX is used in plate A, allother conditions being equal, yellow dye any desired degree of gradation 'ofthe plates A and B can be achieved by a suitable choice of the concentration of Compound XXIX. This method may also be used to obtain the optimum individual gradations in a multipack material, especially by using the appropriate quantity of Compound X'XIX in each individual layer.

\ Example 4 Atranspareti t cellulose'triacetate base is coated successively with the following layers: 1) Gelatinela'ye'r containing the dye of the formula Layer 1.5,u thick.s.-;Dye concentration: 0.11 g./m. (2) Silver bromide gelatin emulsion, red-sensitive. Layer 1.5g. thick. Concentrations 0.55 g. of silver/m (3) Interlay, containing the compound of the Formula XXX. Layer 1.5,u thick. Concentration: 0.44 g. of the compound of the Formula )OCX per m (4) Gelatine layer containing the dye of the formula SOaNa Layer 1.5,u thick. Concentration 0.15 g. of dye/m9.

For comparison the same multi-layer material is prepared but without Compound XXX in layer 3. The two materials are exposed behind a step wedge and processed for (a) 10 minutes in the developer G p-Methylarninophenol sulphate 1 Sodium sulphite, anhydrous 20 Hydroquinone 4 Sodium carbonate, anhydrous 10 Potassium bromide 2 Made up with water to 1 litre.

(b) 2 minutes rinsing in water (0) 6 minutes in stop-fixing bath Sodium thiosulphate, cryst. g.... 200 Sodium sulphite, anhydrous g 15 Sodium acetate (3H O) g 25 Glacial acetic acid ml 13 Water to make 1 litre.

(d) 8 minutes rinsing in water (e) 20 minutes in dye bleaching bath p-Toluene sulphonic acid Sodium hypophosphite, cryst g 2 Potassium iodide ..-g 25 Catalyst (2,3-dimethylquinoxaline) mg 50 Water to make 1 litre.

(f) 4 minutes rinsing in water (g) 8 minutes in silver bleaching bath Potassium ferricyanide 50 Potassium bromide 15 Disodium phosphate 10 Monosodium phosphate 14 Water to make 1 litre. (h) 6 minutes rinsing in water (i) 4 minutes in fixing bath (prepared as for stopfixing bath) (j) 8 minutes rinsing in water.

The following table shows the analytical dye densities depending on the exposure. It is clearly seen that the compound of the Formula XXX prevents the difiusion of the reduced catalyst in the magenta layer but has no influence on the speed of the silver halide layer.

Density of the steps in the magenta layer in percent Without the suh- With the substance of Formula stance of Formula XXX in the XXX in the interlnyer interlayer where A is benzene, naphthalene, diphenyl, pyridine,

quinoline or phenylpyrazolone, B is a diffusion-inhibiting group bound to group A directly or through a -NR-CO,

--CONR, O or NR- bridge where R is hydrogen or an alkyl group having at most 5 carbon atoms, B comprising a linear or branched, saturated or unsaturated,

substituted or unsubstituted hydrocarbon radical which when substituted contains (a) nitrogen, oxygen or nitrogen and oxygen atoms,

as substituents or chain members,

(a) carboxylic nuclei,

(c) carboxylic nuclei and nitrogen, oxygen or nitrogen and oxygen as substituents or chain members, said diffusion-inhibiting group containing at least 8 members, D and E each is an acid group which confers water solubility, m, n, p, and r each is 1 or 2 and q is 1, 2 or 3.

2. A photographic material according to claim 1 in which diifusion-inhibiting group B contains from 8 to 25 carbon atoms and is selected from alkyl, alkylamino, alkanoyl, phenylcarbamoylalkylenecarbonyl, alkylphenoxymethylene, alkanoylaminophenylcarbamoylanilide, alkanoylphenylcarbamoyl, phenoxypolyethyleneoxyalkylene, alkylpyrazolone, N-alkylatedaminophenyl, aliphatic carbocyclic having up to 19 carbon atoms, benzamidodiphenylamino optionally substituted in the diphenyl moiety by lower alkoxy, phenylcarbamoyloxy-polyethylenoxycarbonyl and anilinoalkylene, D and E each is an acid group which confers water solubility, m, n, p and r each is 1 or 3. A photographic material according to claim 2 in which D and E each is a sulfonic or carboxylic acid group.

4. A photographic material according to claim 1 in which A is a benzene or naphthalene radical.

5. A photographic material according to claim 2 in which the bridge is O or NR-CO-.

6. A photographic material according to claim 3 in which A is a benzene ring, D and E each is a sulfonic acid group or a carboxylic acid group, B is an alkyl radical having from 8 to 18 carbon atoms linked to group A through the NHCO bridge or a sulfonated benzene radical substituted by an alkylamino group wherein the alkyl moiety contains from 8 to 18 carbon atoms, said benzene radical being linked to group A through the CONH- bridge, m is 1, n, p, q and r each is 1 or 2.

7. A photographic material as claimed in claim 1 containing a nitro compound of the formula ('lJHa NH-CO-G OZN in which G represents a residue of the formula OxHZXil r C I-I COOH, in which x is a digit of from 11 to 17 and y is a digit of from 14 to 20, and D represents a sulfonic or carboxylic acid group.

'8. A photographic material'as claimed in. claim 1 containing a nitro compound of the formula 1' SOzH 9. A photographic material as claimed in claim 1 containing a nitro compound of the formula (XXIX) OCH:

NH-CO-CuNu OzN SOaH

10. A photographic material as claimed in claim containing a nitro compound of the formula (XXX) H018 11. A photographic material as claimed inclaim 1 of the formula XXXI H1 uHu 'smH References Cited UNITED STATES PATENTS 3,457,074 7/1969 Wilson et a1. 96-73 NORMAN G. TORCHIN P'rimary Examiner R. L. SCHILLING, Assistant Examiner US. Cl. X.R. 9699, 53

V UNITED STATES PATENT OFFICE M CERTIFICATE OF CORRECTION Patent No. 3,782,948 Dated Januarv l, 1914 lnventofls) 'ALFRED FROELICH ET AL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 14, claim 1, line 60, delete "on" and substitute one T 1 V T Column 3 1%,)claim 1, line 5, delete "(a)" and, substitute T T b T P Signed fidsea led thi luth day ofFMay (SEAL) Attest:

EDWARD M.FLETGEER,JR. T M T c. MARSHALL DA I Attesting Officer Comissioneref Patents J