EP0330018A2 - Process for producing colour images, and colour-photographic recording material therefor - Google Patents

Abstract

A process for producing colour images, in which an imagewise exposed, colour-photographic recording material which, on a reflecting base, contains at least one blue-sensitive silver halide emulsion layer and a yellow coupler associated therewith, at least one green- sensitive silver halide emulsion layer and a magenta coupler associated therewith, at least one red-sensitive silver halide emulsion layer and a cyan coupler associated therewith and, if appropriate, further non-photosensitive layers, is subjected to a high-speed processing method, and in which the silver halide emulsion layers have a chloride content of >/= 95 mol% and contain a stabiliser of the formula (I) <IMAGE> in which R<1> is H, optionally substituted C1-C8-alkyl, C2-C8-alkenyl, C5-C10- cycloalkyl, C6-C12-aryl, heteroaryl, SH, or SR<5>, R<2> is H, optionally substituted C1-C6-alkyl, C2-C8-alkenyl, C5-C10- cycloalkyl, C6-C12-aryl, CONR<6>R<7> or COOR<6>, R<3> and R<4> are H, COR<6> or COOR<7>, and R<5>, R<6> and R<7> are C1-C6-alkyl, C2-C8-alkenyl, C5-C10-cycloalkyl, alone or in combination with a stabiliser of the formula (II) <IMAGE> wherein R<8> is H, halogen, C1-C6-alkoxy, C1-C6-alkyl, C1-C6-alkylthio, nitro or optionally substituted amino, acylamino or ureido and n is 1-4, or in combination with a stabiliser of the formula (III) <IMAGE> wherein R<9> is as defined for R<3>/R<4> and Z represents the members required for completing an optionally substituted 5- or 6-membered heterocyclic ring, or in combination with a mixture of II and III, shows improvements with respect to the increase in minimum density on storage (fresh storage, warm storage and long-term storage) and in the case of contamination of the developer bath with thiosulfate.

Description

The invention relates to a method for producing colored images, in which an imagewise exposed color photographic silver halide recording material which contains a special stabilizer or a combination of several stabilizers is subjected to a short processing process.

Furthermore, the invention relates to a particularly suitable color photographic recording material.

It is known to produce color photographic images by chromogenic development, that is to say by developing an imagewise exposed recording material with at least one silver halide emulsion layer in the presence of suitable color couplers by means of suitable color-forming developer substances, the oxidation product of the developer substances with the color coupler which is formed in accordance with the silver image being formed of a dye image reacts.

An important prerequisite for the rapid processing of color photographic recording materials is the use of rapidly developable emulsions. In this regard, chloride-rich silver halide emulsions have proven advantageous. Such emulsions are described, for example, in US-A-4,269,927 and WO 87/04535. Emulsions with at least 80 mol%, preferably with 95-100 mol%, of chloride are suitable.

Silver chloride-rich emulsions, which are characterized by very rapid developability, however, have disadvantages in the form of increased fog. Furthermore, sensitometric changes in long-term storage occur in color photographic recording materials which contain such silver chloride-rich emulsions.

For this reason, photographic silver halide emulsions are added to reduce fog, so-called antifoggants or stabilizers, e.g. B. heterocyclic compounds containing sulfur, for example in the form of a mercapto group.

Such stabilizers are known, in particular in connection with chloride-rich silver halide emulsions, from EP-A-0 246 624. However, they do not always show satisfactory results in terms of veils and long-term storage.

Another important requirement when using the short-term processing method with development times of <2 min. 30 seconds is the absence of bromide ions and benzyl alcohol in the developer bath. Bromide ions act as development inhibitors and are disadvantageous in terms of development speed in a rapid processing process.

The presence of benzyl alcohol in the developer easily gives rise to the separation of tar-like masses in the developer tank. Another disadvantage is due to the easy oxidizability of the benzyl alcohol, which requires careful monitoring and keeping the developer bath constant to ensure uniform development results. It is therefore desirable to develop such recording materials in the absence of benzyl alcohol.

The object of the invention is now to develop a color photographic recording material which is suitable for the short-term processing method and which has a low tendency to fog and to sensitometric changes during long-term storage. However, the advantages of the rapid developability of emulsions rich in silver chloride while at the same time dispensing with bromide and benzyl alcohol in the developer bath should be retained. Furthermore, the increase in fog in developers who are contaminated by thiosulfate ions is to be suppressed.

worin bedeuten
R¹ H, gegebenenfalls substituiertes C₁-C₈-Alkyl, C₂-C₈-Alkenyl, C₅-C₁₀-Cycloalkyl, C₆-C₁₂-Aryl, Heteroaryl, SH, SR⁵
R² H, gegebenenfalls substituiertes C₁-C₆-Alkyl, C₂-C₈-Alkenyl, C₅-C₁₀-Cycloalkyl, C₆-C₁₂-Aryl, CONR⁶R⁷ oder COOR⁶
R³, R⁴, H, COR⁶ oder COOR⁷
R⁵, R⁶, R⁷ C₁-C₆-Alkyl, C₂-C₈-Alkenyl, C₅-C₁₀-Cycloal­kyl
allein oder in Kombination mit einem Stabilisator der Formel (II)

worin bedeuten:
R⁸ H, Halogen, C₁-C₆-Alkoxy, C₁-C₆-Alkyl, C₁-C₆-Al­kylthio, Nitro, gegebenenfalls substituiertes Amino, Acylamino oder Ureido
n 1 - 4
oder in Kombination mit einem Stabilisator der Formel (III)

worin
R⁹ die gleiche Bedeutung wie R³/R⁴ hat, und
Z die zur Vervollständigung eines gegebenenfalls sub­stituierten 5- oder 6-gliedrigen heterocyclischen Ringes benötigten Glieder bedeutet,
oder in Kombination mit einem Gemisch aus II und III, enthalten.The invention relates to a method for producing colored images, in which an imagewise exposed, color photographic recording material, which is on a reflective layer support contains at least one blue-sensitive silver halide emulsion layer and one of these associated yellow couplers, at least one green-sensitive silver halide emulsion layer and one of these associated purple couplers, at least one red-sensitive silver halide emulsion layer and one of these associated cyan couplers and possibly other non-light-sensitive layers, is subjected to a short-time processing process, characterized in that the silver halide is characterized, characterized in that the silver halide have a chloride content of ≧ 95 mol% and a stabilizer of the formula (I)

in what mean
R¹ H, optionally substituted C₁-C₈ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl, C₆-C₁₂ aryl, heteroaryl, SH, SR⁵
R² H, optionally substituted C₁-C₆ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl, C₆-C₁₂ aryl, CONR⁶R⁷ or COOR⁶
R³, R⁴, H, COR⁶ or COOR⁷
R⁵, R⁶, R⁷ C₁-C₆ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl
alone or in combination with a stabilizer of the formula (II)

in which mean:
R⁸ H, halogen, C₁-C₆ alkoxy, C₁-C₆ alkyl, C₁-C₆ alkylthio, nitro, optionally substituted amino, acylamino or ureido
n 1 - 4
or in combination with a stabilizer of formula (III)

wherein
R⁹ has the same meaning as R³ / R⁴, and
Z represents the members required to complete an optionally substituted 5- or 6-membered heterocyclic ring,
or in combination with a mixture of II and III.

The 5- or 6-membered heterocyclic rings completed by Z in formula III can be imidazole, oxazole, thiazole, selenazole, thiadiazole, oxadiazole, tetrazole, pyridine, pyrimidine, triazine and their benzo and represent naphtho derivatives. The heterocyclic compounds can be further substituted. In addition, the substituents customary in the field of photography are possible, for example halogen, such as fluorine, chlorine, bromine; optionally substituted alkyl with preferably up to 8 carbon atoms such as methyl, ethyl, isopropyl; Alkenyl such as allyl; Cycloalkyl such as cyclohexyl; optionally substituted aryl such as phenyl or naphthyl, hydroxy, alkoxy with preferably up to 6 C atoms such as methoxy or butoxy, mercapto, alkylthio with preferably up to 6 C atoms such as methylthio, butylthio; Carboxy, alkoxycarbonyl, sulfo, optionally substituted sulfonamide, nitro, amino, amino substituted with alkyl, aryl or acyl, such as butylamino or acetylamino.

-H und R⁹ -H. Die in Formel (III) durch Z vervoll­ständigten 5- oder 6-gliedrigen heterocyclischen Ringe sind bevorzugt Pyrimidin, Imidazol, Tetrazol, Tiazol und Oxazol, die gegebenenfalls substituiert sein können.The radical R 1 from formula (I) can represent the following heteroaromatics: pyridine, pyrimidine, triazine, imidazole, oxazole, thiazole, furyl and thienyl.

-H and R⁹ -H. The 5- or 6-membered heterocyclic rings completed by Z in formula (III) are preferably pyrimidine, imidazole, tetrazole, tiazole and oxazole, which can optionally be substituted.

Examples of compounds of the formulas (I) are given below:

Compounds according to formula II are listed as examples below:

Examples of stabilizers of the formula III used according to the invention are listed in the table below:

It is advantageous to add the compounds according to the invention in the form of solutions. Suitable solvents are, for example, lower alcohols, tetrahydrofuran, N-methylpyrrolidone or acetone.

The compounds of the formulas I to III are preferably used in amounts of 10⁻⁵ to 5 · 10⁻², preferably 5 · 10⁻⁵ to 10⁻³ mol per mol of silver halide.

The emulsions can contain, in combination with the further antifoggants and stabilizers according to the invention. Suitable are azaindenes, preferably tetra- or penta-azaindenes, in particular those which are substituted by hydroxyl or amino groups. Such connections are, for example, in the article by Birr, Z.Wiss. Phot. 47 , (1952), pp. 2-58. Other suitable stabilizers and antifoggants are given in Research Disclosure No. 17643 of December 1978, Section VI, published by Industrial Opportunities Ltd., Homewell Havant, Hampshire, PO9 1 EF in Great Britain.

The antifoggants, including the compounds of the formula I to III to be used according to the invention, can be added to the light-sensitive silver halide emulsions before chemical ripening, for chemical ripening or after chemical ripening. In a preferred embodiment, they are added to the finished casting solution after chemical ripening.

The silver halide emulsions suitable for rapid development contain at least 95 mol% of chloride, the remainder, which is 100 mol% in addition, consisting of 0 to 5 mol% of bromide, iodide and rhodanide, individually or in combination. Rhodanide is considered to be a halide substitute (pseudohalide). These halides and pseudohalides are preferably used in the following amounts: 0.01 to 0.5 mol% iodide, 0.02 to 5 mol% bromide and 0.02 to 5 mol% rhodanide. The grain size varies from 0.1 to 2.0 µm depending on the layer.

It can be predominantly compact crystals, e.g. are regular cubic or octahedral or can have transitional forms. However, platelet-shaped crystals may preferably also be present, the average ratio of diameter to thickness of which is greater than 5: 1, preferably greater than 8: 1, the diameter of a grain being defined as the diameter of a circle with a circle content corresponding to the projected area of the Kornes.

The silver halide grains can also have a multi-layered grain structure, in the simplest case with an inner and an outer grain area (core / shell), the halide composition and / or other modifications, such as doping of the individual grain areas, being different.

For example, refer to GB-1.027.146. There silver halides with layered grain structure and methods for their preparation are specified. In the present case, other silver halides are struck on the silver chloride grains. Silver bromide is preferred, which may optionally contain small amounts of silver iodide. The amount of other silver halides precipitated is, as stated above, up to 5 mol%. The optimal molar amount of the other silver halide for the respective case can be determined by simple experiments.

The average grain size of the emulsions is preferably between 0.2 μm and 1.0 μm. The grain size distribution is preferably homodisperse, the coefficient of variation ≦ 0.20. Preferred embodiments have a coefficient of variation of ≦ 0.10. In addition to the silver halide, the emulsions can also contain organic silver salts, e.g. Silver benzotriazolate or silver behenate.

Two or more kinds of silver halide emulsions, which are prepared separately, can be used as a mixture.

The photographic emulsions can be prepared using various methods (e.g. P. Glafkides, Chimie et Physique Photographique, Paul Montel, Paris (1967), GF Duffin, Photographic Emulsion Chemistry, The Focal Press, London (1966), VL Zelikman et al, Making and Coating Photographic Emulsion, The Focal Press, London (1966) from soluble silver salts and soluble halides.

The silver halide is preferably precipitated in the presence of the binder, for example the gelatin, and can be carried out in the acidic, neutral or alkaline pH range, silver halide complexing agents preferably being additionally used. The latter include, for example, ammonia, thioether, imidazole, ammonium thiocyanate or excess halide. The water-soluble silver salts and the halides are combined either in succession by the single-jet process or simultaneously by the double-jet process or by any combination of the two processes. Dosing with increasing inflow rates is preferred, the "critical" feed rate, at which no new germs are being produced, should not be exceeded. The pAg range can vary within wide limits during the precipitation, preferably the so-called pAg-controlled method is used, in which a certain pAg value is kept constant or a defined pAg profile is traversed during the precipitation. In addition to the preferred precipitation with an excess of halide, so-called inverse precipitation with an excess of silver ions is also possible. Except by precipitation the silver halide crystals can also grow by physical ripening (Ostwald ripening), in the presence of excess halide and / or silver halide complexing agent. The growth of the emulsion grains can even take place predominantly by Ostwald ripening, preferably a fine-grained, so-called Lippmann emulsion, mixed with a less soluble emulsion and redissolved on the latter.

During the precipitation and / or physical ripening of the silver halide grains, salts or complexes of metals, e.g. Cd, Zn, Pb, Tl, Bi, Ir, Rh, Fe may be present.

The precipitation can also be carried out in the presence of sensitizing dyes. Complexing agents and / or dyes can be rendered ineffective at any time, e.g. by changing the pH or by an oxidative treatment.

After crystal formation has been completed or at an earlier point in time, the soluble salts are removed from the emulsion, e.g. by pasta and washing, by flakes and washing, by ultrafiltration or by ion exchangers.

The silver halide emulsion is generally subjected to chemical sensitization under defined conditions - pH, pAg, temperature, gelatin, silver halide and sensitizer concentration - until the optimum sensitivity and fog are reached. The procedure is described, for example, by H. Frieser "The Basics of Photographic Processes with Silver Halides" page 675-734, Akademische Verlagsgesellschaft (1968).

The chemical sensitization can be carried out with the addition of compounds of sulfur, selenium, tellurium and / or compounds of the metals of subgroup VIII of the periodic table (for example gold, platinum, palladium, iridium), and thiocyanate compounds, surface-active compounds such as thioethers, heterocyclic compounds Nitrogen compounds (e.g. imidazoles, azaindenes) or spectral sensitizers (described, for example, by F. Hamer "The Cyanine Dyes and Related Compounds", 1964, or Ullmanns Encyclopedia of Industrial Chemistry, 4th edition, vol. 18, pp. 431 ff. and Research Disclosure No. 17643, Section III). Alternatively or additionally, a reduction sensitization with the addition of reducing agents (tin-II salts, amines, hydrazine derivatives, aminoboranes, silanes, formamidine sulfinic acid) can be carried out by hydrogen, by low pAg (eg less than 5) and / or high pH (eg above 8) .

As sulfur ripening generally come capable of silver sulfide compounds z. B. thiosulfate, thiourea, thiosemicarbazide and thiocarbamide in question. Thiosulfate is preferred.

Inorganic gold salts are used as gold ripening bodies. Organic gold compounds as described in patents DE-A-854 883 and DE-A-848 910 are also suitable.

The emulsions can only be subjected to sulfur ripening, but also to a combined sulfur / gold ripening (e.g. DE-A 22 63 910).

In a further preferred embodiment, the emulsions are iridium-doped, the amount of iridium being 0.01 to 0.5 μg / gAg.

The photographic emulsion layers or other hydrophilic colloid layers of the light-sensitive material produced according to the invention can contain surface-active agents for various purposes, such as coating aids, to prevent electrical charging, to improve the sliding properties, to emulsify the dispersion, to prevent adhesion and to improve the photographic characteristics ( eg acceleration of development, high contrast, sensitization etc.).

Emulsion production

The production of a monodisperse (coefficient of variation <0.2) silver chloride emulsion with an average grain diameter of 0.8 µm is described below, the following solutions being used in a double-inlet process: Solution E 1: Distilled water 1,000 ml gelatin 100 g Solution E 2: Distilled water 3,000 ml Silver nitrate 1,000 g Solution E 3: Distilled water 1,000 ml Ammonium chloride 370 g Na₂IrCl₆ solution (0.01%) 5 g Na₃RhCl₆ solution (0.001%) 1 ml Solution E 1: Distilled water 9,000 ml gelatin 900 g

The initial solution E 1 was heated to 55 ° C. and adjusted to pH 5.0. With intensive mixing, the solutions E 2 and E 3 heated to 55 ° C. were simultaneously within 60 min. added. At the beginning it was the running-in speed 70 ml / min. In the further course it was slowly increased to 8 times the metering speed. After the end of the run-in, the emulsion was cooled and then freed from the soluble salts by flocculation and washing in the customary manner. The washed flocculate was then redispersed in solution E 4 within 30 min with simultaneous stirring at 40.degree. The emulsion was then mixed with 0.05 mol% KI and 0.4 mol% KBr per mol AgNO₃ and 120 min at 50 ° C and 2 x 10⁻⁵ mol thiosulfate per mol AgNO₃ and 2 x 10⁻⁶ mol HAuCl₄ matured per mole of AgNO₃. After the maturation, the emulsion was spectrally sensitized (amount of sensitizer: 4 x 10⁻⁴ mol per mol of AgNO₃) and mixed with 100 ml of a 1 wt .-% solution of a stabilizer. More details about the sensitizer and stabilizer are given in the example.

Suitable spectral sensitizers are polymethine dyes, such as neutrocyanines, basic or acidic carbocyanines, rhodacyanines, hemicyanines, styryl dyes, oxonols and the like. Such sensitizers are described by F. M. Hamer in "The Cyanine Dyes and related Compounds", (1964). In this regard, reference is made in particular to Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, volume 18, pages 431 ff and to Research Disclosure No. 17 643, section IV, given above.

In the color photographic recording materials according to the invention, at least one is predominantly blue-sensitive, one predominantly green-sensitive and a predominantly red-sensitive silver halide emulsion layer is stacked on top of one another on a layer support. If the blue-sensitive layer is arranged at the top of the layer structure, there can be a layer with a yellow filter dye underneath and above the green- or red-sensitive layers. Furthermore, intermediate layers can be arranged between two silver halide emulsion layers of different spectral sensitivity. The predominantly blue-sensitive silver halide emulsion layer contains a yellow coupler, the predominantly green-sensitive silver halide emulsion layer contains a magenta coupler and the predominantly red-sensitive silver halide emulsion layer contains a cyan coupler. In the recording material according to the invention, the light-sensitive layers are coated on an opaque light-reflecting substrate, for example on a paper substrate which can carry a barite layer and / or can be covered on one or both sides with a layer of a polyolefin.

The photographic material of the present invention may contain one or more polymers as a binder for the silver halide and the color couplers. A common binder is gelatin. However, this can be replaced in whole or in part by other synthetic, semi-synthetic or naturally occurring polymers. Synthetic gelatin substitutes are, for example, polyvinyl alcohol, poly-N-vinylpyrrolidone, polyacrylamides, polyacrylic acid and their derivatives, in particular copolymers. Naturally occurring gelatin substitutes are, for example, others Proteins such as albumin or casein, cellulose, sugar, starch or alginates, semi-synthetic gelatin substitutes are generally modified natural products.

Cellulose derivatives such as hydroxyalkyl cellulose, carboxymethyl cellulose and phthalyl cellulose as well as gelatin derivatives which have been obtained by reaction with alkylating or acylating agents or by grafting on polymerizable monomers are examples of this. For use as a binder, it is important that the polymers in question still have a sufficient amount of functional groups, so that enough resistant layers can be produced by reaction with suitable curing agents. Such functional groups are in particular amino groups, but also carboxyl groups, hydroxyl groups and active methylene groups. The preferred binder of the color photographic recording material according to the invention is gelatin.

The layers of the photographic material can be hardened in the usual manner, for example with hardeners of the epoxy type, the heterocyclic ethylene imine and the acryloyl type. Furthermore, it is also possible to harden the layers in accordance with the process of German laid-open specification 2 218 009 in order to obtain color photographic materials which are suitable for high-temperature processing. It is also possible to harden the photographic layers with hardeners of the diazine, triazine or 1,2-dihydroquinoline series or with Vinyl sulfone type hardeners. Further suitable hardening agents are known from German laid-open documents 2 439 551, 2 225 230, 2 317 672 and from Research Disclosure 17 643, section XI, mentioned above.

Further suitable additives are given in Research Disclosure 17 643 and in "Product Licensing Index" from December 1971, pages 107-110. The use of instant hardeners is particularly preferred.

Immediate hardeners are understood to mean compounds which crosslink suitable binders in such a way that the hardening is completed immediately after casting or at the latest after 24 hours, preferably after 8 hours, to the extent that no further change in the sensitometry caused by the crosslinking reaction and the swelling of the layer structure occurs. Swelling is understood to mean the difference between the wet layer thickness and the dry layer thickness during the aqueous processing of the film (Photogr. Sci. Eng. 8 (1964), 275; Photogr. Sci. Eng. 16 (1972), 449.

These hardeners, which react very quickly with gelatin, are e.g. B. carbamoylpyridinium salts, which presumably are able to react with free carboxyl groups of the proteinaceous binder, so that the latter can react with free amino groups to form paptid bonds and crosslinking.

worin bedeuten:
R¹⁰ und R¹¹ einzeln gleich oder verschieden, jeweils eine Alkylgruppe mit 1 bis 8 Kohlenstoffatomen oder eine gegebenen­falls mit einer Alkylgruppe mit 1 oder 2 Kohlenstoffatomen oder mit einem Halo­genatom substituierte Aryl- oder Aralkyl­gruppe, oder zusammen die zur Vervoll­ständigung eines gegebenenfalls mit einer Alkylgruppe mit 1 oder 2 Kohlenstoffato­men oder mit einem Halogenatom substi­tuierten heterocyclischen Ringes, z. B. eines Piperidin- oder Morpholinringes erforderlichen Atome,
R¹² ein Wasserstoffatom oder eine Alkylgruppe mit 1 oder 2 Kohlenstoffatomen,
n gleich 0 oder 2.Suitable examples of instant hardeners are compounds of the following general formulas:

in which mean:
R¹⁰ and R¹¹ individually the same or different, each an alkyl group having 1 to 8 carbon atoms or an aryl or aralkyl group optionally substituted with an alkyl group with 1 or 2 carbon atoms or with a halogen atom, or together to complete an optionally with an alkyl group with 1 or 2 carbon atoms or a heterocyclic ring substituted with a halogen atom, e.g. B. a piperidine or morpholine ring required atoms,
R¹² represents a hydrogen atom or an alkyl group with 1 or 2 carbon atoms,
n is 0 or 2.

Such curing agents are described, for example, in DE-A-24 39 551. Examples of such curing agents (H-) are listed below:

In the production of the light-sensitive color photographic recording material, the diffusion-resistant couplers can be incorporated into the casting solution of the silver halide emulsion layers or other colloid layers in a known manner. For example, the oil-soluble or hydrophobic couplers can preferably be added to a hydrophilic colloid solution from a solution in a suitable coupler solvent (oil former), if appropriate in the presence of a wetting or dispersing agent. The hydrophilic casting solution can of course contain other conventional additives in addition to the binder. The solution of the coupler need not be directly dispersed in the casting solution for the silver halide emulsion layer or other water permeable layer; she can rather, it is also advantageous first to disperse in an aqueous, non-photosensitive solution of a hydrophilic colloid, whereupon the mixture obtained, if appropriate after the removal of the low-boiling organic solvents used, is mixed with the casting solution for the photosensitive silver halide emulsion layer or another water-permeable layer before application.

Corresponding methods are described, for example, in US Pat. No. 2,322,027, DE-A-1,722,192 and EP-A-0 043 037. The compounds can also be introduced into the casting solution in the form of loaded latices. Reference is made, for example, to DE-A-25 41 230, DE-A-25 41 274, DE-A-28 35 856, EP-A-0 014 921, EP-A-0 069 671, EP-A-0 130 115, U.S.-A-4,291,113.

The color photographic recording material according to the invention for producing multicolored images contains, 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. 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 usually achieved in that the Color coupler is contained in the silver halide emulsion layer itself or in a neighboring, optionally non-light-sensitive binder layer.

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).

One or more color couplers can be assigned to each of the differently spectrally sensitized silver halide emulsion layers. If there are several silver halide emulsion layers of the same spectral sensitivity, each of them can contain a color coupler, which color couplers need not necessarily be identical. They should only result in at least approximately the same color during color development, normally a color that is complementary to the color of the light, for which the silver halide emulsion layers in question are predominantly sensitive.

In preferred embodiments, red-sensitive silver halide emulsion layers are consequently assigned to at least one non-diffusing color coupler for producing the blue-green partial color image, usually one Phenol or α-naphthol type couplers. Suitable color couplers are described in EP-A-0 184 057, EP-A-0 175 573, EP-A-0 161 626, EP-A-0 028 099, EP-A-0 067 689, EP-A-0 142 086, DE-A-2 028 601.

Green-sensitive silver halide emulsion layers are assigned at least one non-diffusing color coupler for producing the purple partial color image, color couplers of the 5-pyrazolone, indazolone or various pyrazoloazole type usually being used. Purple couplers of this type can be found in DE-A-3 516 996 and DE-A-3 516 945.

Finally, blue-sensitive silver halide emulsion layers are assigned at least one non-diffusing color coupler for generating the yellow partial color image. 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 (1972).

The color couplers can be both conventional 4-equivalent couplers and 2-equivalent couplers, which use a smaller number to produce color Amount of silver halide is required. As is well known, 2-equivalent couplers are derived from the 4-equivalent couplers in that they contain a substituent in the coupling site, which is split off during the coupling. The 2-equivalent couplers include both those that are practically colorless and those that have an intense intrinsic color that disappears when the color is coupled or is replaced by the color of the image dye produced. The latter couplers can also be present in the light-sensitive silver halide emulsion layers and serve there as mask couplers to compensate for the undesired secondary densities of the image dyes. However, the known white couplers are also to be counted among the 2-equivalent couplers, but they do not give any dye when reacted with color developer oxidation products. Among the 2-equivalent couplers are also the known DIR couplers, which are couplers which contain a detachable residue in the coupling point, which is released as a diffusing development inhibitor when reacted with color developer oxidation products. Other photographically active compounds, e.g. Development aferators or fogging agents can be released from such couplers during development.

The couplers can also be in polymeric form, e.g. B. come as a polymer latex for use.

High molecular weight color couplers are described for example in DE-C-1 297 417, DE-A-24 07 569, DE-A-31 48 125, DE-A-32 17 200, DE-A-33 20 079, DE-A-33 24 932, DE-A-33 31 743, DE-A-33 40 376, EP-A-27 284, US-A -4 080 211. The high molecular weight color couplers are generally produced by polymerizing ethylenically unsaturated monomeric color couplers.

The color couplers used can also be those which provide dyes with poor or restricted mobility.

Examples of particularly suitable yellow couplers are given in the following table:

Examples of particularly suitable cyan couplers are given in the following table:

The following connections can be used as purple couplers:

In addition to the constituents mentioned, the color photographic recording material of the present invention can contain further additives, such as, for example, antioxidants, dye-stabilizing agents and agents for influencing the mechanical and electrostatic properties. In order to reduce or avoid the adverse effect of UV light on the color images produced with the color photographic recording material according to the invention, it is advantageous, for example, to absorb UV-absorbing compounds in one or more of the layers contained in the recording material, preferably in one of the upper layers to use.

Suitable UV absorbers are described for example in US-A-3 253 921, DE-C-2 036 719 and EP-A-0 057 160.

In order to produce color photographic images, the color photographic recording material according to the invention is developed with a color developer compound. All developer compounds which have the ability to react in the form of their oxidation product with color couplers to form azomethine dyes can be used as the color developer compound. Suitable color developer compounds are aromatic compounds of the p-phenylenediamine type containing at least one primary amino group, for example N, N-dialkyl-p-phenylenediamines, such as N, N-diethyl-p-phenylenediamine, 1- (N-ethyl-N-methylsulfonamidoethyl) -3 -methyl-p-phenylenediamine, 1- (N-ethyl-N-hydroxyethyl-3-methyl-p-phenylenediamine and 1- (N-ethyl-N-methoxyethyl) -3-methyl-p-phenylenediamine.

Other 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.

The recording material according to the invention is particularly suitable for processing in an abbreviated processing process, for example in a processing process whose development step takes less than 3 minutes, preferably less than 1 minute, at temperatures between 25 and 45 ° C. Advantageous results are obtained especially when developing with benzyl alcohol-free developer baths.

The color developer solution preferably contains ≦ 0.01 mol / l bromide and ≦ 5 ml / l benzyl alcohol.

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, e.g. Fe³⁺ salts and Fe³⁺ complex salts such as ferricyanides, dichromates, water-soluble cobalt complexes, etc. Particularly preferred are iron III complexes of aminopolycarboxylic acids, in particular e.g. Ethylenediaminetetraacetic acid, N-hydroxyethylethylenediamine triacetic acid, alkyliminodicarboxylic acids and corresponding phosphonic acids. Persulphates are also suitable as bleaching agents.

The compositions and processing times of the development and bleach-fix bath in which the material according to the invention is processed are given below. Watering is followed by usual drying. a) Color developer - 45 s - 35 ° C Triethanolamine 9.0 g / l NN-diethylhydroxylamine 4.0 g / l Diethylene glycol 0.05 g / l 3-methyl-4-amino-N-ethyl-N-methanesulfonamidoethyl aniline sulfate 5.0 g / l Potassium sulfite 0.2 g / l Triethylene glycol 0.05 g / l Potassium carbonate 22 g / l Potassium hydroxide 0.4 g / l Ethylenediaminetetraacetic acid di-Na salt 2.2 g / l Potassium chloride 2.5 g / l 1,2-Dihydroxybenzene-3,4,6-trisulfonic acid trisodium salt 0.3 g / l make up to 1,000 ml with water; pH 10.0 b) bleach-fix bath - 45 s - 35 ° C Ammonium thiosulfate 75 g / l Sodium bisulfite 13.5 g / l Ammonium acetate 2.0 g / l Ethylenediaminetetraacetic acid (iron ammonium salt) 57 g / l 25% ammonia 9.5 g / l acetic acid 9.0 g / l make up to 1,000 ml with water; pH 5.5 c) Soak - 2 min - 33 ° C

example 1

In the following test setups, the spectrally sensitized emulsions prepared by the above process were mixed with stabilizer and then stirred at 40 ° C. for 10 minutes.

The following compounds were used for comparison with the stabilizers or stabilizer combinations according to the invention:

The following Table 1 shows nine differently stabilized blue, green or red sensitized silver halide emulsions, three serving as a comparison and six containing the stabilizers or stabilizer combinations according to the invention. Table 1 Emulsion no. Awareness raising Stabilizers Concentration of (mmol stabilizer / mol AgNO₃) 1 (comparison) blue STA-2 0.4 2 " green STA-1 0.6 3 " red STA-3 0.5 4 (according to the invention) blue I-3 0.4 5 " green I-3 0.6 6 " green I-3 / III-7 0.3 / 0.3 7 " green I-3 / II-4 / III-7 0.2 / 0.2 / 0.2 8th " red I-11 0.5 9 " red I-3 / II-4 0.3 / 0.2

The silver halide emulsions sensitized and stabilized in this way are supplemented to form casting suspensions in accordance with the following regulation and cast on a reflective layer support (polyethylene-coated paper on both sides). Previously, a substrate layer consisting of 0.2 g / m² gelatin with the addition of KNO₃ and chrome alum is applied as the bottom layer.

A portion of the casting suspension of each test is first stirred at 40 ° C. for 24 h and then poured.

The quantities given relate to 1 m². For the silver halide application, the corresponding amounts of AgNO₃ are given.

Blue-sensitized emulsions 1 and 4:

0,29 g Trikresylphosphat (TKP) versetzt.The monodisperse silver halide emulsion described above for a layer application corresponding to 0.63 g AgNO₃ per m² is blue-sensitized and with
1.38 g gelatin
0.95 g yellow coupler Y-10
0.2 g white coupler W-1

0.29 g tricresyl phosphate (CPM) was added.

Green sensitized emulsions 2, 5, 6 and 7

The monodisperse silver halide emulsion described above for a layer application corresponding to 0.45 g AgNO₃ per m² is green-sensitized and with
1.08 g gelatin
0.41 g purple coupler M-26
0.16 g of ethyl α- (3-t-butyl-4-hydroxyphenoxy) myristic acid
0.08 g 2,5-dioctyl hydroquinone
0.34 g dibutyl phthalate (DBP)
0.4 g CPM added.

Red-sensitized emulsions 3, 8 and 9

The monodisperse silver halide emulsion described above for a layer application corresponding to 0.3 g AgNO₃ per m² is red-sensitized and with
0.75 g gelatin
0.36 g cyan coupler C-13
0.36 g CPM added.

The layers were hardened with a hardening layer consisting of 0.6 g / m² gelatin and 0.29 g / m² hardening agent H-15.

The different stabilization of the layers can be seen in Table 1.

After the test sheets were produced, the material was cut open and in some cases immediately exposed under a gray wedge and processed in the specified short-term process (Fresh material without storage); In some cases, the material was subjected to a processing variant in which the developer bath of the rapid process was mixed with 40 mg / l ammonium thiosulfate (simulation of a thiosulfate contamination of the developer, which increases the fog). Another part of the material was subjected to storage at 60 ° C. before exposure and processing or stored for 3 months in a normal climate. The minimum density of the color complementary to the spectral sensitization was then measured using a Macbeth sensitometer.

Table 2 below shows the results of the measurements: Table 2 Emulsion no. Stabilizers Filter color of the densitometer Minimum density fresh Minimum density after stirring for 24 hours at 40 ° C Minimum density after storage for 3 days at 60 ° C Minimum density after storage 3 months in normal climate Minimum density after thiosulfate development 1 (comparison) STA-2 blue 0.109 0.137 0.121 0.119 0.122 2 " STA-1 green 0.098 0.112 0.116 0.104 0.106 3 " STA-3 red 0.110 0.108 0.109 0.112 0.106 4 (according to the invention) I-3 blue 0.105 0.122 0.121 0.114 0.110 5 " I-3 green 0.092 0.096 0.100 0.090 0.095 6 " I-3 / III-7 green 0.090 0.098 0.098 0.094 0.099 7 " I-3 / II-4 / III-7 green 0.092 0.095 0.098 0.093 0.098 8th " I-11 red 0.100 0.101 0.100 0.103 0.105 9 " I-3 / II-4 red 0.098 0.104 0.102 0.102 0.103

The other sensitometric properties, in particular the sensitivity of emulsions 4 to 9 measured at a density of 0.6, were comparable to the values of the comparison emulsions 1 to 3.

Example 2

In this example, two complete layer structures with spectrally differently sensitized silver halide emulsion layers were compared with one another, emulsions 1, 2 and 3 being used in the comparison structure and the layer structure according to the invention containing emulsions 4, 6 and 9 (see example 1). The layer structures described below represent a color photographic material which is suitable for a rapid processing process and which was produced on paper coated on both sides with polyethylene with the following layers in the order given.

Layer structure 1 (comparison)

• 1st layer (substrate layer):
  0.2 g gelatin
• 2nd layer: blue-sensitive layer with emulsion 1
• 3rd layer (protective layer)
  1.1 g gelatin
  0.06 g 2,5-dioctylhydroquinone
  0.06 g dibutyl phthalate (DBP)
• 4th layer: green-sensitive layer with emulsion 2
• 5th layer (UV protective layer)
  1.15 g gelatin
  0.6 g UV absorber of the formula
  
  0.045 g 2,5-dioctyl hydroquinone
  0.04 g CPM
• 6th layer: red-sensitive layer with emulsion 3
• 7th layer (UV protective layer)
  0.35 g gelatin
  0.15 g UV absorber as in layer 5
  0.2 g CPM
• 8th layer (protective layer)
  0.6 g gelatin
  0.3 g of H-15 curing agent

Experimental setup 2 (according to the invention)

The layers and the layer sequences correspond to experimental setup 1 with the following changes:

In layer 2, emulsion 4 was used instead of emulsion 1,
in layer 4 was emulsion 6 instead of emulsion 2 and
in layer 6 was emulsion 9 instead of emulsion 3
used.

The materials produced in this way were processed and stored as in Example 1.

The minimum densities were measured in all three colors complementary to the sensitizations.

The following table 3 shows the measured minimum densities of test setups 1 and 2 under different processing and storage conditions: Table 3 Emulsion no. Stabilizers Filter color of the densitometer Minimum density fresh Minimum density after storage for 3 days at 60 ° C Minimum density after storage 3 months in normal climate Minimum density after thiosulfate development 1 (comparison) STA-2 blue 0.128 0.142 0.144 0.135 2 " STA-1 green 0.114 0.130 0.110 0.114 3 " STA-3 red 0.108 0.107 0.108 0.106 4 (according to the invention) I-3 blue 0.120 0.130 0.135 0.125 6 " I-3 / III-7 green 0.105 0.120 0.108 0.109 9 " I-3 / II-4 red 0.099 0.100 0.102 0.104

The results of the measurements from Examples 1 and 2 show that both the individual emulsion layer and the multilayer photographic material are better stabilized by the stabilization according to the invention than by the conventional one. The improvement concerns the "fresh" minimum density, i. H. immediate processing without storage, the minimum density in hot air storage (60 ° C) and long-term storage in normal climate. It was shown in the individual emulsions that the stability is improved even with prolonged stirring of the emulsion (24 h, 40 ° C.).

The minimum increases in density caused by developer contamination with ammonium thiosulfate are also reduced.

Claims (13)

1. A method for producing colored images, in which an imagewise exposed color photographic recording material which has at least one blue-sensitive silver halide emulsion layer and a yellow coupler assigned to it on a reflective layer support, at least one green-sensitive silver halide emulsion layer and one associated purple coupler, at least one red-sensitive silver halide emulsion layer and one cyan coupler assigned to it and optionally contains further non-light-sensitive layers, is subjected to a short-term processing process, characterized in that the silver halide emulsion layers have a chloride content of ≧ 95 mol% and a stabilizer of the formula I

in what mean
R¹ H, optionally substituted C₁-C₈ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl, C₆-C₁₂ aryl, heteroaryl, SH, SR⁵
R² H, optionally substituted C₁-C₆ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl, C₆-C₁₂ aryl, CONR⁶R⁷ or COOR⁶
R³, R⁴ H, COR⁶ or COOR⁷
R⁵, R⁶, R⁷ C₁-C₆ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl
alone or in combination with a stabilizer of the formula (II)

in which mean:
R⁸ H, halogen, C₁-C₆ alkoxy, C₁-C₆ alkyl, C₁-C₆ alkylthio, nitro, optionally substituted amino, acylamino or ureido
n 1 - 4
or in combination with a stabilizer of formula (III)

wherein
R⁹ has the same meaning as R³ / R⁴, and
Z represents the members required to complete an optionally substituted 5- or 6-membered heterocyclic 5- ring,
or in combination with a mixture of II and III. 2. The method of claim 1, wherein the color photographic material is developed in a color developer solution having a bromide content of ≦ 0.01 mol / l. 3. The method according to claim 1, wherein the color developer bath has a content of ≦ 5 ml / l benzyl alcohol. 4. The method of claim 1, wherein the short-term processing process comprises a development treatment step and one or more treatment steps for removing the formed silver and the remaining silver halide, and wherein the development treatment step takes less than 3 minutes at temperatures between 25 and 45 ° C. 5. The method according to claim 1, characterized in that the development treatment step at temperatures between 25 and 45 ° C takes less than 1 minute. 6. The method according to claim 1, characterized in that

R⁹ is -H and the 5- or 6-membered heterocyclic rings completed by Z in formula III are pyrimidine, imidazole, tetrazole, thiazole and oxazole. 7. Color photographic recording material which contains at least one blue-sensitive silver halide emulsion layer and a yellow coupler assigned to it, at least one green-sensitive silver halide emulsion layer and one associated purple coupler, at least one red-sensitive silver halide emulsion layer and one associated cyan-green coupler and optionally other non-light-sensitive layers on a reflective layer support, characterized in that that the silver halide emulsion layers have a chloride content of ≧ 95 mol%, and a stabilizer of the formula I.

in what mean
R¹ H, optionally substituted C₁-C₈ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl, C₆-C₁₂ aryl, heteroaryl, SH, SR⁵
R² H, optionally substituted C₁-C₆ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl, C₆-C₁₂ aryl, CONR⁶R⁷ or COOR⁶
R³, R⁴ H, COR⁶ or COOR⁷
R⁵, R⁶, R⁷ C₁-C₆ alkyl, C₂-C₈ alkenyl, C₅-C₁₀ cycloalkyl
or in combination with a stabilizer of the formula (II)

in which mean:
R⁸ H, halogen, C₁-C₆ alkoxy, C₁-C₆ alkyl, C₁-C₆ alkylthio, nitro, optionally substituted amino, acylamino or ureido
n 1 - 4
or in combination with a stabilizer of formula (III)

wherein
R⁹ has the same meaning as R³ / R⁴, and
Z represents the members required to complete an optionally substituted 5- or 6-membered heterocyclic 5- ring,
or in combination with a mixture of II and III. 8. Color photographic recording material according to claim 7, characterized in that the amount of stabilizers of the formulas I, II and III used to stabilize the silver halide emulsion layers is 10⁻⁵ to 5 x 10⁻² mol / mol Ag. 9. Color photographic recording material according to claim 7, characterized in that the silver halide emulsions contain 0 to a maximum of 5 mol% bromide and / or iodide and / or rhodanide. 10. Color photographic recording material according to claim 7, characterized in that the silver halide emulsions have a bromide content of 0.02 to 5 mol%. 11. Color photographic recording material according to claim 7, characterized in that the silver halide emulsions have an iodide content of ≦ 1 mol%. 12. Color photographic recording material according to claim 7, characterized in that

R⁹ is -H and the 5- or 6-membered heterocyclic rings completed by Z in formula III are pyrimidine, imidazole, tetrazole, thiazole and oxazole. 13. Color photographic recording material according to claim 7, characterized in that the silver halide emulsion layers are doped with 0.01-0.5 µg per g AgNO₃ Na₂IrCl₆ and / or Na₃RhCl₆.