EP0309819B1 - Colour-photographic recording material - Google Patents

Description

The invention relates to a color photographic recording material with at least one silver halide emulsion layer and at least one layer to which a purple coupler of the pyrazolone type is assigned.

In general, compounds derived from pyrazolone-5 are used as magenta couplers, ie as color couplers which are suitable for producing the magenta color image. Common purple couplers are, for example, pyrazolone-5 compounds which are substituted in the 3-position by an acylamino group. In contrast, 3-anilinopyrazolone-5-couplers are characterized by low secondary densities in both the red and blue spectral range, by heating, tropical and storage cabinet stability, by excellent light stability of the azomethine dyes formed with p-phenylenediamines and by high reactivity and coupling activity.

To improve the effectiveness of the color formation, 2-equivalent purple couplers were used, in which a substituent is introduced into the coupling position of the purple coupler of the pyrazolone type and is split off as an escape group during color development. Couplers of this type are described, for example, in US Pat. Nos. 3,311,476, 3,419,391, 3,617,291 and 3,926,631 and in DE-A 25 36 191, 26 51 363 and 27 03 589. Further purple couplers in which a substituent, in particular an aryl radical, is attached to the coupling position by a sulfur atom are described in US Pat. Nos. 3,214,437, 4,032,346, 3,227,554, 3,701,783 and 4,383,027 in EP-A 0 081 768, in JA 34044/78 and in DE-A 29 44 601 and 33 18 759.

Such 2-equivalent couplers couple in normal processing with a sufficiently high color formation rate, which has a favorable effect in terms of saving silver and couplers. Various syntheses are known for producing such 2-equivalent purple couplers. According to one of these methods, suitable thiophenol, for example, is converted to the sulfenyl chloride and reacted with a sulfinic acid, in particular an aromatic sulfinic acid. The thiosulfonic acid ester thus obtained can then be reacted with the 4-equivalent purple coupler in an alcoholic alkaline medium to give the desired 2-equivalent coupler (DE-A-3 241 886). This method gives good results. Nevertheless, it is not yet satisfactory insofar as the 2-equivalent purple couplers synthesized after this suffice after recrystallization to a degree of purity of the photographic requirements and can hardly be obtained in yields above 60%.

• sie kuppeln mit steiler Gradation, was die Brillanz der Bilder verbessert;
• sie kuppeln mit hoher Farbausbeute, was einen geringeren Silberauftrag möglich macht;
• sie sind stabil gegen schädigende Gase sowie bei Feucht/Heiß- und Hellagerung, was sich in deutlich verminderter Vergilbung der Bildweißen niederschlägt.

This increases the price for such couplers very much. Nevertheless, these connections (2-equivalent purple couplers) have great advantages:

• they couple with steep gradation, which improves the brilliance of the images;
• they couple with a high color yield, which makes it possible to apply less silver;
• they are stable against harmful gases as well as when stored in damp / hot and light conditions, which is reflected in significantly reduced yellowing of the image whites.

On the other hand, extensive studies have now shown that the speed of the color formation reaction, which results in the case of the 2-equivalent coupler from the addition of oxidized color developer and the elimination of an escape group, is significantly lower than when using 4-equivalent couplers, in which the addition of oxidized color developers then a (further) oxidation reaction. In the case of shortened processing, this leads to the undesirable result in the case of the use of 2-equivalent purple couplers, that although the full color density can be obtained after some time after the processing has been completed, the color formation is still incomplete immediately when the processing is completed, which Assessment extremely difficult. The delayed dye formation can take up to several weeks depending on the storage conditions.

The invention has for its object to provide a color photographic recording material with which even with shortened processing immediately after processing, color images with a high color density are obtained, the color coordination of which no longer changes significantly after completion of the processing. At the same time, the recording material should have all the advantages of 2-equivalent purple couplers and the purple couplers used should be easily accessible.

worin bedeuten

n

1 bis 5;

m

1 bis 3;

R¹

Halogen, Alkoxy, Alkylthio, Acylamino, Carbamoyl, Sulfonamido, Sulfamoyl oder Alkoxycarbonyl;

R²

Halogen, Cyano, Thiocyanato, Alkoxy, Alkyl, Acylamino, Carbamoyl, Sulfonylamido, Sulfamoyl oder Alkoxycarbonyl,

und eine Thiosulfonsäureesterverbindung enthält.The invention relates to a color photographic recording material with at least one light-sensitive silver halide emulsion layer, to which a purple coupler of the pyrazolone type is assigned, characterized in that the layer containing the purple coupler was produced by casting a casting solution containing a 4-equivalent purple coupler of the following formula I

in what mean

n

1 to 5;

m

1 to 3;

R¹

Halogen, alkoxy, alkylthio, acylamino, carbamoyl, sulfonamido, sulfamoyl or alkoxycarbonyl;

R²

Halogen, cyano, thiocyanato, alkoxy, alkyl, acylamino, carbamoyl, sulfonylamido, sulfamoyl or alkoxycarbonyl,

and contains a thiosulfonic acid ester compound.

Die erfindungsgemäß verwendete Thiosulfonsäureesterverbindung entspricht vorzugsweise der Formel II



        R³-SO₂-S-R⁴



worin

R³ und R⁴

unabhängig voneinander Alkyl, Aralkyl, Aryl oder eine heterocyclische Gruppe bedeuten.

Examples of 4-equivalent purple couplers of Formula I are listed below:

The thiosulfonic acid ester compound used according to the invention preferably corresponds to formula II



R³-SO₂-S-R⁴



wherein

R³ and R⁴

are independently alkyl, aralkyl, aryl or a heterocyclic group.

An alkyl group represented by R³ or R⁴ can contain up to 20 carbon atoms, for example, and can be straight-chain or branched. It can also be substituted e.g. by halogen, amino, alkoxycarbonyl, alkylsulfonyl, aryl or a heterocyclic group.

An aryl group represented by R³ or R⁴ is, for example, a phenyl group which may be substituted, e.g. by halogen, alkyl, alkoxy, aroxy, alkylthio, amino, acylamino, sulfonamides, carbamoyl, sulfamoyl or a heterocyclic group.

A heterocyclic group can be, for example: quinolyl, pyrazolyl, tetrazolyl, triazolyl, imidazolyl, benzimidazolyl, tetrahydrofuryl, pyridyl, where these heterocyclic groups can be substituted, for example with halogen, alkyl, alkoxy, alkylthio, acylamino or aryl.

A list of suitable residues R³ (sulfinic acid component) is given below:

   Beispiele für die erfindungsgemäß verwendete Thiosulfonsäureester der Formel II sind im folgenden aufgeführt:



        R³-SO₂-S-R⁴

A list of suitable radicals R Th (thiol component) is given below:

Examples of the thiosulfonic acid esters of the formula II used according to the invention are listed below:



R³-SO₂-S-R⁴

The compounds of formula II are known and can be synthesized by methods as described in Houben Weyl, Methods of Organic Chemistry, Vol. E11, p. 1113 ff. Processes in which sulfinic acids or salts thereof are reacted with sulfenoic acid halides are preferred. Compounds of formula II are also described in DE-A-32 41 886.

Synthesis compound II-7

388 g of 2,4-diisopropylthiophenol are dissolved in 1,500 ml of dichloromethane and slowly mixed with 161 ml of sulfuryl chloride at room temperature. The mixture is stirred for 30 minutes and the acid gases and the solvent are distilled off. The residue is turned into a at room temperature Suspension of 365 g of p-toluenesulfinic acid sodium salt in dichloromethane slowly introduced. After the reaction is complete, the mixture is poured onto water, separated off, washed and dried. After the solvent has been stripped off, it can be recrystallized from methanol,
Yield 585 g (= 84% of theory)
Mp 74 ° C

Synthesis compound II-12

• a) Cetylsulfinic acid
  200 g of cetyl sulfonic acid chloride are in
  87 ml hydrazine hydrate in
  600 ml of methanol entered at room temperature. The sulfonic acid hydrazide precipitates and can be suctioned off. The residue is then placed in a solution of
  48 g NaOH in
  1,500 ml of water and
  1,000 ml of methanol and slowly heated to boiling while stirring. Solvent is slowly distilled off and the mixture is kept at 90 to 95 ° C. for about 4 hours. After cooling, cetylsulfinic acid sodium salt is suctioned off. The compound is dried.
  Yield 170 g (= 91% of theory)
• b) Cetylthiosulfonic acid dodecyl ester
  36 g of dodecanethiol are, as described above, with sulfuryl chloride in the corresponding sulfenyl chloride This compound is added to a suspension of 56 g of the compound obtainable under a). The mixture is stirred for a further 2 hours, evaporated and the residue obtained is recrystallized from ethanol.
  Mp 56-57 ° C
  Yield 77 g (= 87% of theory),

4-equivalent purple coupler (I) and thiosulfonic acid ester (II) are added together to the coating solution for the purple layer, poured into the layer and dried. Couplers (I) and thiosulfonic acid esters (II) are generally used in a molar ratio between 0.25: 1 and 2.0: 1, preferably between 0.7: 1 and 1.2: 1 and in particular in an approximately equimolar amount.

Photographic recording materials with a magenta layer obtained in this way have sensitometric properties such as color yield and gradation and stability properties, as would be expected from the use of 2-equivalent magenta couplers subsequent change in gradation. In this respect, the recording materials with the magenta layers according to the invention behave much more than if they contained unchanged 4-equivalent magenta couplers. This finding, in particular the high coupling activity, which suggests the presence of 2-equivalent purple couplers, is surprising. Because comparative tests have shown that mixtures of compounds of the formulas I and II are completely stable under the conditions existing in photographic recording materials (oil formers, optionally auxiliary solvents, wetting agents, gelatin, silver halide, hardening agents) in vitro, ie without the preparation of thin layers.

• a) in Dibutylphthalat und Ethylacetat
• b) in Trikresylphosphat und Ethylacetat
• c) wie a) jedoch unter Zusatz von fester Gelatine
• d) wie b) jedoch unter Zusatz von fester Gelatine
• e) wie a) jedoch unter Zusatz von 5 %iger wäßriger Gelatine und einem Netzmittel
• f) wie b) jedoch unter Zusatz von 5 %iger wäßriger Gelatine und einem Netzmittel
• g) wie e) jedoch unter Zusatz eines Soforthärtungsmittels, z.B. CAS Reg. No` 65 411-60-1
• h) wie f) und einem Zusatz eines Soforthärtungsmittels.

This could be shown in a series of experiments first at room temperature, later at 55 ° C. The same compound of the formula I and the same compound of the formula II were mixed with one another and dissolved

• a) in dibutyl phthalate and ethyl acetate
• b) in tricresyl phosphate and ethyl acetate
• c) as a) but with the addition of solid gelatin
• d) as b) but with the addition of solid gelatin
• e) as a) but with the addition of 5% aqueous gelatin and a wetting agent
• f) as b) but with the addition of 5% aqueous gelatin and a wetting agent
• g) as e) but with the addition of an instant hardening agent, e.g. CAS Reg. No` 65 411-60-1
• h) as f) and an addition of an instant hardener.

In addition, common emulsions of the two compounds I and II and casting solutions were prepared by admixing silver halide emulsions.

The samples mentioned were processed in a suitable manner and examined by thin layer chromatography. It was shown that there is practically no 2-equivalent coupler (max. 10%) in all operations, i.e. that under these conditions the formation of the target compounds is excluded. This proves the surprising effect that a reaction of the compounds of the formulas I and II takes place only in the photographic material (possibly because of the shorter distances in the dried form).

In the preparation of the light-sensitive color photographic recording material of the present invention, the 4-equivalent purple couplers (I) and the compounds of the formula II are worked together in a known manner, if appropriate with the aid of suitable oil formers, in a casting solution for a silver halide emulsion layer or another colloid layer. 4-equivalent purple couplers and thiosulfonic acid esters can be added to a hydrophilic colloid solution from separate solutions or from a common solution in a suitable coupler solvent (oil former), optionally in the presence of a wetting or dispersing agent

The oil formers are substances which generally boil above 180 ° C and have good dissolving power for the substances to be dispersed. Among these, the esters of glutaric acid, adipic acid, phthalic acid, sebacic acid, succinic acid, maleic acid, fumaric acid, isophthalic acid, terephthalic acid and phosphoric acid or the esters of glycerol, as well as paraffin and fluorinated paraffin are preferably used because these compounds are chemically stable and very easily accessible, very much can be handled easily and have no adverse effect on the photosensitive materials when the dispersions are used for photographic purposes. For example, the following are frequently used as oil formers: tricresyl phosphate, triphenyl phosphate, dibutyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, glycerol tributyrate, glycerol tripropionate, dioctyl sebacate, paraffin and fluorinated paraffin. Monoesters of fatty succinic acids have also proven to be advantageous. Such compounds are described in US Pat. No. 3,689,271. Carboxylic acid dialkylamides such as, for example, diethyllauramide, palmitic acid diethylamide and phthalic acid dialkylamides are also suitable as oil formers.

Occasionally, the compounds of the formula II or, possibly, the sulfinic acids formed therefrom have oil-forming properties or have a favorable effect on the stability of the coupler dispersion present in the dried layer. The presence of the sulfinic acids formed may continue to act because of their effects Antioxidants can be beneficial. Since they are generally not photographically inert - under certain conditions they can, for example, reduce blue-green indoaniline dyes to the leuco dyes - it is sometimes advantageous when selecting the compound of the formula II of diffusion-resistant sulfinic acids, e.g. a sulfinic acid with at least 16 carbon atoms.

The hydrophilic casting solution can of course contain other conventional additives in addition to the binder. The coupler and thiosulfonic acid ester solution need not be directly dispersed in the casting solution for the silver halide emulsion layer or other water permeable layer; on the contrary, it can also be advantageously first dispersed in an aqueous, non-photosensitive solution of a hydrophilic colloid, whereupon the mixture obtained, after removal of the low-boiling organic solvents used, may be mixed with the coating solution for the photosensitive silver halide emulsion layer or another water-permeable layer before application,

The light-sensitive silver halide emulsions used in the light-sensitive layers can contain chloride, bromide and iodide or mixtures thereof as the halide. These are preferably chloride-rich emulsions with a bromide content of less than 1 mol%.

The emulsions can be heterodisperse or else monodisperse emulsions, which preferably have an average grain size of 0.3 μm to 1.2 μm. The silver halide grains can also have a layered grain structure.

The emulsions can be chemically and or spectrally sensitized in the usual way; they can also be stabilized by suitable additives. Suitable chemical sensitizers, spectral sensitizing dyes and stabilizers are described, for example, in Research Disclosure 17643 (December 1978); Reference is made in particular to chapters III, IV and VI.

The color photographic recording material according to the invention preferably contains at least one silver halide emulsion layer for recording light from each of the three spectral ranges red, green and blue, which is spectrally sensitized in a known manner by means of suitable sensitizing dyes.

A layer which is not sensitive to light is generally arranged between layers of different spectral sensitivity and may contain means for preventing the incorrect diffusion of developer oxidation products. If there are several silver halide emulsion layers of the same spectral sensitivity, these can be directly adjacent to one another or be arranged such that there is a light-sensitive layer with a different spectral sensitivity between them (DE-A-19 58 709, DE-A-25 30 645, DE-A- 26 22 922).

Color photographic recording materials according to the invention usually contain, in spatial and spectral assignment to the silver halide emulsion layers of different spectral sensitivity, color couplers for producing the different partial color images cyan, purple and yellow, the purple coupler generally being assigned to a green-sensitive silver halide emulsion layer.

Spatial assignment is understood to mean that the color coupler is in such a spatial relationship to the silver halide emulsion layer that an interaction between them is possible which permits an image-wise match between the silver image formed during development and the color image generated from the color coupler. This is generally achieved by the fact that the color coupler is contained in the silver halide emulsion layer itself or in a possibly non-light-sensitive binder layer adjacent to it.

Spectral assignment is understood to mean that the spectral sensitivity of each of the light-sensitive silver halide emulsion layers and the color of the partial color image generated from the spatially assigned color coupler are in a specific relationship to one another, with each of the spectral sensitivities (red, green, blue) having a different color of the relevant partial color image (in general, for example, the colors cyan, purple or yellow in this order).

In preferred embodiments, red-sensitive silver halide emulsion layers are therefore assigned at least one non-diffusing color coupler for producing the blue-green partial color image, generally a coupler of the phenol or α-naphthol type. Green-sensitive silver halide emulsion layers are assigned at least one non-diffusing color coupler for generating the purple partial color image, which according to the invention has been incorporated into the layer in question as a 4-equivalent purple coupler together with a thiosulfonic acid ester.

Finally, blue-sensitive silver halide emulsion layers are assigned at least one non-diffusing color coupler for producing the yellow partial color image, usually a color coupler with an open-chain ketomethylene grouping. Color couplers of this type are known in large numbers and are described in a large number of patents. Examples include the publications "Farbkuppler" by W. PELZ in "Mitteilungen aus den Forschungslaboratorien der Agfa, Leverkusen / München", Volume III, page 111 (1961) and by K. VENKATARAMAN in "The Chemistry of Synthetic Dyes", Vol 4, 341 to 387, Academic Press (1971).

For the recording materials used according to the invention, the customary layer supports, for example supports made of cellulose esters, for example cellulose acetate, and are suitable Polyesters. Also suitable are paper supports which can optionally be coated, for example with polyolefins, in particular with polyethylene or polypropylene. In this regard, reference is made to Research Disclosure 17643, Chapter XVII.

The usual hydrophilic film-forming agents are suitable as protective colloid or binder for the layers of the recording material, e.g. Proteins, especially gelatin. Casting aids and plasticizers can be used. Reference is made to Research Disclosure 17643, Chapter IX, XI and XII.

The layers of the photographic material can be hardened in the usual manner, for example with hardeners which contain at least two reactive oxirane, aziridine or acryloyl groups. Furthermore, it is also possible to harden the layers in accordance with the process described in DE-A-22 18 009. It is also possible to harden the photographic layers or the color photographic multilayer materials with hardeners of the diazin, triazine or 1,2-dihydroquinoline series or with hardeners of the vinyl sulfone type. Other suitable curing agents are known from DE-A-24 39 551, DE-A-22 25 230, DE-A-24 39 551 and also from Research Disclosure 17 643, Chapter X. The stabilizing effect of the oil formers according to the invention is particularly pronounced when hardening agents which activate carboxyl groups, for example carbamoylpyridinium or carbamoyloxypyridinium salts, are used.

Further suitable additives are given in Research Disclosure 17 643 and in "Product Licensing Index" from December 1971 pages 107-110.

Suitable color developer substances for the material according to the invention are in particular those of the p-phenylenediamine type, for example 4-amino-N, N-diethyl-aniline hydrochloride, 4-amino-3-methyl-N-ethyl-N-β- (methanesulfonamido) -ethyl-aniline sulfate hydrate , 4-amino-3-methyl-N-ethyl-N-β-hydroxyethylaniline sulfate, 4-amino-N-ethyl-N- (2-methoxy-ethyl) -m-toluidine-di-p-toluenesulfonic acid and N-ethyl -N-β-hydroxyethyl-p-phenylenediamine. Further useful color developers are described, for example, in J.Amer.Chem.Soc. 73 , 3100 (1951) and in G. Haist, Modern Photographic Processing, 1979, John Wiley and Sons, New York, pages 545 ff.

After color development, the material is usually bleached and fixed. Bleaching and fixing can be carried out separately or together. The usual compounds can be used as bleaching agents, for example Fe³⁺ salts and Fe³⁺ complex salts such as ferricyanides, dichromates, water-soluble cobalt complexes etc. Iron-III complexes of aminopolycarboxylic acids, in particular, for example, ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, N are particularly preferred -Hydroxyethylethylenediamintriessigsäure, alkyliminodicarboxylic acids and corresponding phosphonic acids. Persulphates are also suitable as bleaching agents.

example 1

• 1. Entwickler
  (1 l Ansatz)
  800 ml Wasser, dest.
  4,5 g 4-(N-Ethyl-N-β-hydroxyethylamino)-2-methyl-anilinsulfat
  2,5 g Hydroxylammoniumsulfat
  4,0 g Natriumsulfit
  1,5 g Natriumhydrogencarbonat
  33,5 g Kaliumcarbonat
  1,35 g Kaliumbromid
  mit dest. Wasser auf 1 l auffüllen pH: 10,0
• 2. Bleichbad
  (1 l Ansatz)
  800 ml Wasser
  139 g Ammoniumbromid
  86 g Ethylendiamintetraessigsaures Ammonium
  16 g Ethylendiamintetraessigsäure
  10 g Ammoniak
  mit Wasser auf 1 l auffüllen und mit ca. 15 ml Eisessig pH 6,0 einstellen.
• 3. Fixierbad
  (1 l Ansatz)
  800 ml Wasser
  150 g Ammoniumthiosulfat
  10 g Natriumsulfit
  2 g Natriumsulfit
  2 g Natriumhexmetaphosphat
  mit Wasser auf 1 l auffüllen, pH: ca. 7,5

Color photographic materials were prepared and processed as follows.
a) Production of the color coupler disgate
8 mmol of color coupler and, if appropriate, 8 mmol of aryl or alkylthiosulfone esters as indicated in Table 1 are dissolved in the same amount by weight of dibutyl phthalate and three times the amount by weight of ethyl acetate in the presence of 0.15 g of dioctyl sulfosuccinate at a temperature of 50 to 75 ° C. The solution is then stirred into 150 g of 7.5% strength by weight aqueous gelatin solution at about 40 ° C.
b) Production of the color photographic recording materials to be tested
The dispersate prepared under a) is mixed with a silver halide emulsion which contains 8.2 g of silver in the form of silver bromide, 9.2 g of gelatin and 0.04 g of sodium dodecylbenzenesulfonate. The total volume is adjusted to 350 ml with water. The casting solution prepared in this way is poured onto a layer of cellulose triacetate.
c) curing and drying
A hardening layer of 400 mg gelatin and 400 mg instant hardening agent [CAS Reg.No. 65 411-60-1] poured. The layer structure is dried at 50 to 60 ° C.
d) processing and evaluation
Development cycle (temperature 38 ° C) bath min Color development 3.25 Bleach bath 6.5 Watering 3rd Fixer 6.5 Watering 6

• 1. Developer
  (1 l approach)
  800 ml water, dist.
  4.5 g of 4- (N-ethyl-N-β-hydroxyethylamino) -2-methyl-aniline sulfate
  2.5 g of hydroxylammonium sulfate
  4.0 g sodium sulfite
  1.5 g sodium hydrogen carbonate
  33.5 g potassium carbonate
  1.35 g potassium bromide
  with dist. Make up water to 1 liter pH: 10.0
• 2. Bleach bath
  (1 l approach)
  800 ml of water
  139 g ammonium bromide
  86 g of ethylenediaminetetraacetic acid ammonium
  16 g of ethylenediaminetetraacetic acid
  10 g ammonia
  Make up to 1 l with water and adjust to pH 6.0 with approx. 15 ml glacial acetic acid.
• 3. Fixer bath
  (1 l approach)
  800 ml of water
  150 g ammonium thiosulfate
  10 g sodium sulfite
  2 g sodium sulfite
  2 g sodium hexmetaphosphate
  Make up to 1 liter with water, pH: approx.7.5

Table 1 shows the color yield FA, the sensitivity E and the gradation γ for numerous material samples.

It can be seen from Table 1 that the coupling activity of the 4-equivalent purple couplers (I) is significantly increased when thiosulfonic acid esters (II) are added. The increased color yield enables a reduced application quantity of 4-equivalent purple couplers in photographic materials and accordingly a reduced application quantity of silver halide. Table 1 sample I. II FA E γ 1 I-1 2.35 19.2 1.05 2nd I-14 2.16 19.8 0.98 3rd I-16 2.48 18.8 1.10 4th I-8 2.33 18.6 1.03 5 I-1 II-7 2.83 18.4 2.20 6 I-14 II-7 2.47 19.0 1.95 7 I-16 II-7 2.68 18.0 2.10 8th I-8 II-7 2.55 18.3 1.95 9 I-1 II-9 2.75 18.9 1.92 10th I-14 II-9 2.54 19.0 1.82 11 I-16 II-9 2.62 18.8 1.84 12th I-1 II-33 2.67 19.0 1.86 13 I-16 II-33 2.56 19.2 1.78 14 I-1 II-5 2.85 18.2 2.10 15 I-16 II-5 2.74 18.6 2.04 16 I-8 II-5 2.72 18.7 1.96 17th I-1 II-1 2.80 18.4 2.22 18th I-16 II-1 2.78 18.6 2.08

Example 2

Color coupler dispersion gates are produced similarly to Example 1 and a silver chloride emulsion is added in such a way that casting solutions with 20 g of magenta coupler, 12.5 g of silver and 54 g of gelatin are obtained. These casting solutions are similarly cast onto a layer support made of paper coated on both sides with polyethylene to give a silver coating (Ag) of approximately 0.3 g / m 2.

The layers are cured and dried as in Example 1.

Samples of the layers are exposed with a step wedge and processed as follows.

Development 2

a) Color developer - 45 s - 35 ° C Triethanolamine 9.0 g NN-diethylhydroxylamine 6.0 g Diethylene glycol 0.05 g 3-methyl-4-amino-N-ethyl-N-methanesulfonamidoethyl aniline sulfate 6.0 g Potassium sulfite 0.2 g Triethylene glycol 0.05 g Potassium carbonate 22 g Potassium hydroxide 0.4 g Ethylenediaminetetraacetic acid di-Na salt 2.2 g make up to 1,000 ml with water; pH 9.2.
b) bleach-fix bath - 45 s - 33 ° C Ammonium thiosulfate 75 g Sodium bisulfite 13.5 g Ammonium acetate 2.0 g Ethylenediaminetetraacetic acid (iron ammonium salt) 57 g 25% ammonia 9.5 g acetic acid 9.0 g
c. Soak - 2 min - 33 ° C

Table 2 shows the gradation γ₂ and the maximum color density D _max for many of the material samples obtained in this way, one for the freshly processed material and the other after 10 days of storage.

γ₂ is the gradation in the upper part of the color density curve and is determined as the slope of the straight line that intersects the color density curve at points B and C, where A is the curve point that is 0.1 density units above fog, B is the curve point that one exposure is 0.8 log It units higher than A, and C is the curve point corresponding to 0.8 log It units higher exposure than B.

The maximum color density D _{max of} the freshly processed material is also given (in brackets) as a percentage, in each case based on the corresponding value D _{max of} the same sample after 10 days of storage.

From Table 2 it can be seen that the mixtures according to the invention consisting of 4-equivalent purple coupler and thiosulfonic acid ester give advantageous sensitometric results when measured immediately after processing, both in comparison with the 4-equivalent purple coupler alone and also in comparison with the corresponding 2-equivalent purple coupler alone . After 10 days of storage, practically no change in the sensitometric values was observed in the samples according to the invention as well as in the comparison samples which contained the 4-equivalent purple coupler alone, while in the comparison samples which contained the 2-equivalent purple coupler contained alone, the sensitometric values rise sharply within 10 days to the level of the sensitometric values of the samples according to the invention.

This makes it clear that the recording material according to the invention does not have the disadvantage of delayed dye formation in the short-term processing which is otherwise observed when using 2-equivalent purple couplers.

Tabelle 2 Folgende Schichten wurden hergestellt: Probe I II γ₂ D_max (%) γ₂ D_max frisch 10 Tage 31 I-1 2,40 2,38 (100) 2,41 2,38 32 I-16 2,52 2,62 (100) 2,50 2,62 33 V-1 1,41 <1,0 (<37) 2,20 2,69 34 V-2 2,08 1,56 ( 38) 2,83 4,12 35 V-3 2,42 2,96 ( 69) 2,78 4,32 36 V-4 2,48 3,05 ( 67) 2,80 4,54 37 I-1 II-24 2,44 2,32 ( 81) 2,74 2,86 38 I-1 II-8 2,64 2,96 ( 73) 2,82 4,04 39 I-16 II-7 2,62 4,12 ( 96) 2,78 4,30 40 I-16 II-12 2,72 4,32 ( 98) 2,75 4,40 41 I-1 II-1 2,82 4,64 ( 99) 2,84 4,68 The following 2-equivalent purple couplers were used as comparison couplers:

Table 2 The following layers were made: sample I. II γ₂ D _max (%) γ₂ D _max fresh 10 days 31 I-1 2.40 2.38 (100) 2.41 2.38 32 I-16 2.52 2.62 (100) 2.50 2.62 33 V-1 1.41 <1.0 (<37) 2.20 2.69 34 V-2 2.08 1.56 (38) 2.83 4.12 35 V-3 2.42 2.96 (69) 2.78 4.32 36 V-4 2.48 3.05 (67) 2.80 4.54 37 I-1 II-24 2.44 2.32 (81) 2.74 2.86 38 I-1 II-8 2.64 2.96 (73) 2.82 4.04 39 I-16 II-7 2.62 4.12 (96) 2.78 4.30 40 I-16 II-12 2.72 4.32 (98) 2.75 4.40 41 I-1 II-1 2.82 4.64 (99) 2.84 4.68

Example 3

• 1. Eine Substratschicht aus 200 mg Gelatine mit KNO₃- und Chromalaunzusatz
• 2. Eine blauempfindliche Silberchloridemulsionsschicht aus 600 mg AgNO₃ mit 2.100 mg Gelatine, 1,1 mmol Gelbkuppler, 27,7 mg 2,5-Dioctylhydrochinon und 1.200 mg Trikresylphosphat
• 3. Eine Zwischenschicht aus 1.300 mg Gelatine, 80 mg 2,5-Dioctylhydrochinon und 100 mg Trikresylphosphat

• 4. Eine grünempfindliche Silberchloridemulsionsschicht aus 530 mg AgNO₃ mit 750 mg Gelatine, 0,625 mmol Purpurkuppler, wie aus folgender Tabelle 3 ersichtlich, 118 mg α-(3-t-Butyl-4-hydroxyphenoxy-myristinsäureethylester, 43 mg 2,5-Dioctylhydrochinon und Ölbildner, wie aus folgender Tabelle 3 ersichtlich
• 5. Eine Zwischenschicht aus 1.550 mg Gelatine, 285 mg UV-Absorber Tinuvin 343 ®, 80 mg Dioctylhydrochinon und 650 mg Trikresylphosphat
• 6. Eine rotempfindliche Silberchloridemulsionsschicht aus 400 mg AgNO₃ mit 1.470 mg Gelatine, 0,780 mmol Blaugrünkuppler, 285 mg Dibutylphthalat und 122 mg Trikresylphosphat
• 7. Eine Schutzschicht aus 1.200 mg Gelatine und 134 mg Tinuvin 343 ®
• 8. Eine Härtungsschicht aus 400 mg Gelatine und 400 mg eines Soforthärters [CAS Reg. No. 65411-60-1)

A layer support made of paper coated on both sides with polyethylene was provided with the following layers. The quantities refer to 1 m².

• 1. A substrate layer of 200 mg of gelatin with KNO₃- and Chromalaunzusatz
• 2. A blue-sensitive silver chloride emulsion layer made of 600 mg AgNO₃ with 2,100 mg gelatin, 1.1 mmol yellow coupler, 27.7 mg 2,5-dioctylhydroquinone and 1,200 mg tricresyl phosphate
• 3. An intermediate layer of 1,300 mg gelatin, 80 mg 2,5-dioctyl hydroquinone and 100 mg tricresyl phosphate

• 4. A green-sensitive silver chloride emulsion layer made of 530 mg AgNO₃ with 750 mg gelatin, 0.625 mmol magenta coupler, as can be seen from the following Table 3, 118 mg α- (3-t-butyl-4-hydroxyphenoxy-myristinic acid ethyl ester, 43 mg 2,5-dioctylhydroquinone and Oil formers, as can be seen in Table 3 below
• 5. An intermediate layer of 1,550 mg gelatin, 285 mg UV absorber Tinuvin 343 ®, 80 mg dioctyl hydroquinone and 650 mg tricresyl phosphate
• 6. A red-sensitive silver chloride emulsion layer made of 400 mg AgNO₃ with 1,470 mg gelatin, 0.780 mmol cyan coupler, 285 mg dibutyl phthalate and 122 mg tricresyl phosphate
• 7. A protective layer of 1200 mg gelatin and 134 mg Tinuvin 343 ®
• 8. A hardening layer consisting of 400 mg gelatin and 400 mg of an instant hardener [CAS Reg. 65411-60-1)

The following couplers were used in layers 2 and 6:

Yellow coupler

Teal coupler

   Die Kuppler- und Silberhalogenidmengen in Schicht 4 gelten für den Fall, daß der Purpurkuppler ein 4-Äquivalentkuppler ohne beigemischten Thiosulfonsäureester ist. Wenn ein Thiosulfonsäureester beigemischt ist oder wenn ein 2-Äquivalentpurpurkuppler verwendet wird, beträgt die Kupplerauftragsmenge 0,5 mmol und die entsprechende Silberchloridmenge entspricht 450 mg AgNO₃.

The amounts of coupler and silver halide in layer 4 apply in the event that the magenta coupler is a 4-equivalent coupler without added thiosulfonic acid ester. If a thiosulfonic acid ester is added or if a 2-equivalent purple coupler is used, the amount of coupler applied is 0.5 mmol and the corresponding amount of silver chloride corresponds to 450 mg of AgNO₃.

Tabelle 3 (Schicht 4) Probe I II 61 I-1 - 62 I-16 - 63 V-1 - 64 V-3 - 65 V-5 - 66 I-1 II-24 67 I-1 II-9 68 I-1 II-7 69 I-16 II-7 70 I-16 II-12 Various recording materials were produced which differed only in layer 4, as can be seen from the following Table 3:
The following 2-equivalent purple coupler was used as a comparison compound V-5:

Table 3 (Layer 4) sample I. II 61 I-1 - 62 I-16 - 63 V-1 - 64 V-3 - 65 V-5 - 66 I-1 II-24 67 I-1 II-9 68 I-1 II-7 69 I-16 II-7 70 I-16 II-12

The samples were exposed to the same extent behind a grayscale wedge with white light and processed in accordance with the short-term process described in Example 2. The samples thus obtained were freshly assessed visually and measured densitometrically. In addition, light stability tests were carried out using a xenon lamp.

• A) Die Vergleichsproben 61 und 62 mit hohem Kuppler- und Silberauftrag waren neutral, die Purpurfarbstoffe waren vergleichbar stabil jedoch die verbliebenen Restkuppler vergilbten bei Lagerung; bei Probe 61 stärker als bei Probe 62 (schlechte Bildweißen).
• B) Die Vergleichsproben 63 bis 65 mit geringem Kuppler- und Silberauftrag waren nach der Entwicklung stark farbstichig und das Material Kippte von neutralgrau bei geringer Dichte nach grüngrau bei hoher Dichte. Die densitometrische Messung ergab, daß die Farbdichte des Purpurfarbstoffes ein Maximum durchlief. Die Lichtbeständigkeit des Purpurfarbstoffes war gut; der Restkuppler vergilbte nur wenig.
• C) Bei den erfindungsgemäßen Proben 66 bis 70 mit geringem Kuppler- und Silberauftrag waren nach der Entwicklung neutralgrau; die Lichtbeständigkeit des Purpurfarbstoffes war gut, die Vergilbungstendenz gering.

The following photographic results were obtained:

• A) The comparative samples 61 and 62 with high coupler and silver application were neutral, the purple dyes were comparably stable, but the remaining couplers yellowed when stored; with sample 61 stronger than with sample 62 (poor image whiteness).
• B) The comparative samples 63 to 65 with a small amount of coupler and silver applied had a strong color cast after development and the material tipped from neutral gray with low density to green gray with high density. The densitometric measurement showed that the color density of the purple dye went through a maximum. The lightfastness of the purple dye was good; the rest of the coupler yellowed only a little.
• C) In samples 66 to 70 according to the invention with a small amount of coupler and silver applied, were neutral gray after development; the lightfastness of the The purple dye was good, the tendency to yellowing was low.

Better photographic test results, with the advantage of lower quantities compared to 4-equivalent purple couplers and the advantage of better and cheaper chemical preparative access compared to 2-equivalent purple couplers (synthesis losses between 30 and 50%) impressively demonstrate the advantages of using 4-equivalent purple couplers together with thiosulfonic acid esters photographic layers.

Claims (5)

1. Colour photographic recording material having at least one light-sensitive silver halide emulsion layer with which a magenta coupler of the pyrazolone series is associated, characterised in that the layer containing the magenta coupler was prepared by casting a casting solution containing a 4-equivalent magenta coupler corresponding to the following formulaI

   

   wherein

   n   denotes 1 to 5;

   m   denotes 1 to 3;

   R¹   denotes halogen, alkoxy, alkylthio, acylamino, carbamoyl, sulphonamido, sulphamoyl or alkoxycarbonyl;

   R²   denotes halogen, cyano, thiocyanato, alkoxy, alkyl, acylamino, carbamoyl, sulphonylamido, sulphamoyl or alkoxycarbonyl,

   and a thiosulphonic acid ester compound.
2. Recording material according to Claim 1, characterised in that the thiosulphonic acid ester compound corresponds to the following general formula II
   
   
   
           R³-SO₂-S-R⁴
   
   
   
   wherein
   R³ and R⁴ denote, independently of one another, alkyl, aralkyl, aryl or a heterocyclic group.
3. Recording material according to Claim 1, characterised in that 4-equivalent magenta couplers and thiosulphonic acid esters are used in a molar ratio of from 0.25:1 to 2.0:1.
4. Recording material according to Claim 3, characterised in that coupler and thiosulphonic acid ester are used in a molar ratio of from 0.7:1 to 1.2:1.
5. Recording material according to Claim 2, characterised in that R³ contains at least 16 carbon atoms.