EP0537545B1 - Silver halide photographic material - Google Patents

Description

The invention relates to a color photographic silver halide material with at least one silver halide emulsion layer containing a color coupler, the silver halide grains of which have a layered grain structure, and which is assigned a DIR compound, the reaction of which with the oxidized color developer proceeds with a high reaction rate constant.

It is known that silver halide emulsions with a high silver chloride content can be developed in a shorter time than those with a low silver chloride content. However, these short-term processes have the disadvantage of adversely affecting sharpness and color rendering. Attempts to overcome these disadvantages with the aid of so-called DIR compounds, ie with compounds which release a compound which inhibits development in the reaction with the oxidized color developer, do not lead to the desired success in the case of conventional emulsions with a high chloride content.

The object of the invention was to provide a color photographic silver halide material which can be developed in a short-term process and yet has excellent sharpness and color rendering.

This object is surprisingly achieved in that certain DIR compounds and silver halide emulsions which have a minimum proportion of AgCl and a layered grain structure are used in combination.

The invention therefore relates to a color photographic silver halide material with at least one silver halide emulsion layer containing at least one color coupler, the silver halide grains of which contain 40 to 90 mol% of AgCl and at least two zones of different halide composition, the outer zone having a chloride content which is at least 10 mol% higher than that inner zone, and which is assigned a DIR compound whose reaction with the oxidized color developer has a reaction rate constant k> 2000 [l / mol · s].

A zone is said to comprise at least 5 mol% of the total silver halide, preferably at least 10 mol%. In addition, the silver halide grains can also contain layers of different halide compositions which make up less than 5 mol% of the total silver halide.

In addition to silver chloride, the silver halide grains essentially contain silver bromide and optionally up to 15 mol% of silver iodide. They are preferably AgBrCl emulsions.

Preferably each zone comprises at least 10 mole percent silver halide, especially at least 20 mole percent.

• Emulsion 1: Silberbromidchloridemulsion mit einem mittleren Teilchendurchmesser von 1,60 »m, einem Verteilungskoeffizienten von 77 %, einem Kern (Zone 1) aus AgBr und einer Hülle (Zone 2) aus AgCl, wobei der Kern 30 Mol-% ausmacht.
• Emulsion 2: Silberbromidchloridemulsion mit einem mittleren Teilchendurchmesser von 1,70 »m und einem Verteilungskoeffizienten von 77 %, einem Kern aus AgBr, einer ersten Hülle aus AgCl und einer zweiten Hülle aus AgBr, wobei der Kern 25 Mol-% und die erste Hülle 70 Mol-% ausmachen.
• Emulsion 3: Silberbromidchloridiodidemulsion mit einem mittleren Teilchendurchmesser von 1,82 »m und einem Verteilungskoeffizienten von 60 %, einem Kern aus AgBr_0,9I_0,1, einer ersten Hülle aus AgBr und einer zweiten Hülle aus AgCl, wobei der Kern 10 Mol-% und die erste Hülle 20 Mol-% ausmachen.
• Emulsion 4: Silberbromidchloridemulsion mit einem mittleren Teilchendurchmesser von 1,75 »m, einem Verteilungs koeffizienten von 80 %, einem Kern aus AgBr, einer ersten Hülle aus AgBr_0,05Cl_0,95 und einer zweiten Hülle aus AgBr_0,5Cl_0,5, wobei der Kern 10 Mol-% und die erste Hülle 80 Mol-% ausmachen.

Some typical emulsions according to the invention are listed below:

• Emulsion 1 : Silver bromide chloride emulsion with an average particle diameter of 1.60 »m, a distribution coefficient of 77%, a core (zone 1) made of AgBr and a shell (zone 2) made of AgCl, the core making up 30 mol%.
• Emulsion 2 : Silver bromide chloride emulsion with an average particle diameter of 1.70 »m and a distribution coefficient of 77%, a core made of AgBr, a first shell made of AgCl and a second shell made of AgBr, the core being 25 mol% and the first shell 70 Make up mol%.
• Emulsion 3 : Silver bromide chloride iodide emulsion with an average particle diameter of 1.82 »m and a distribution coefficient of 60%, a core made of AgBr _0.9 I _0.1 , a first shell made of AgBr and a second shell made of AgCl, the core being 10 mol -% and make up the first shell 20 mol%.
• Emulsion 4 : Silver bromide chloride emulsion with an average particle diameter of 1.75 »m, a distribution coefficient of 80%, a core made of AgBr, a first shell made of AgBr _0.05 Cl _0.95 and a second shell made of AgBr _0.5 Cl _{0 , 5} , the core making up 10 mol% and the first shell 80 mol%.

The boundaries between zones of different halide compositions can be sharp or unsharp. In the case of a blurred boundary, the boundary between adjacent zones is defined by the fact that at the boundary the halide content of a particular halide is equal to the mean of the halide contents of the same halide of the homogeneous regions of the adjacent zones.

The zones of different chloride content result from the precipitation conditions.

The silver halide can be predominantly compact crystals, e.g. B. are regular cubic or octahedral or can have transitional forms. However, platelet-shaped crystals can also be present, the average ratio of diameter to thickness of which is preferably at least 5: 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 grain. The layers can also have tabular silver halide crystals, where the ratio of diameter to thickness is greater than 5: 1, e.g. B. 12: 1 to 30: 1.

The average grain size of the emulsions is preferably between 0.2 »m and 2.0» m, the grain size distribution can be both homo- and heterodisperse. In addition to the silver halide, the emulsions can also contain organic silver salts, e.g. B. silver benzotriazolate or silver behenate.

Monodisperse emulsions are particularly preferred in which at least 70% of the spheres equal in volume to the emulsion grains have diameters that are between 0.8 times and 1.3 times the most frequent ball diameter. The distribution is determined using electrolytic methods (DE-A 2 025 147).

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 composition of the water-soluble silver salts and the halides is carried out 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 excess halide, so-called inverse precipitation with excess silver ions is also possible. In addition to 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 Oswald ripening, a fine-grained, so-called Lippmann emulsion preferably being mixed with a less soluble emulsion and being redissolved on the latter.

Salts or complexes of metals such as Cd, Zn, Pb, Tl, Bi, Ir, Rh, Fe may also be present during the precipitation and / or physical ripening of the silver halide grains.

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.

Gelatin is preferably used as the binder. 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-vinylpyrolidone, polyacrylamides, polyacrylic acid and their derivatives, in particular their copolymers. Naturally occurring gelatin substitutes are, for example, other proteins such as albumin or casein, cellulose, sugar, starch or alginates. Semi-synthetic gelatin substitutes are usually modified natural products. Cellulose derivatives such as hydroxyalkyl cellulose, carboxymethyl cellulose and phthalyl cellulose and gelatin derivatives, which have been obtained by reaction with alkylating or acylating agents or by grafting on polymerizable monomers, are examples of this.

The binders should have a sufficient amount of functional groups, so that by reaction enough suitable layers can be produced with suitable hardening agents. Such functional groups are in particular amino groups, but also carboxyl groups, hydroxyl groups and active methylene groups.

The gelatin which is preferably used can be obtained by acidic or alkaline digestion. The production of such gelatins is described, for example, in The Science and Technology of Gelatine, published by A.G. Ward and A. Courts, Academic Press 1977, page 295 ff. The gelatin used in each case should contain the lowest possible level of photographically active impurities (inert gelatin). High viscosity, low swelling gelatins are particularly advantageous. The gelatin can be partially or completely oxidized.

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 photographic emulsions may contain compounds to prevent fogging or to stabilize the photographic function during production, storage or photographic processing.

Azaindenes are particularly suitable, preferably tetra- and penta-azaindenes, in particular those which are substituted by hydroxyl or amino groups. Such connections are e.g. B. von Birr, Z. Wiss. Phot. 47 (1952), pp. 2-58. Salts of metals such as mercury or cadmium, aromatic sulfonic or sulfinic acids such as benzenesulfinic acid, or nitrogen-containing heterocycles such as nitrobenzimidazole, nitroindazole, (subst.) Benzotriazoles or benzothiazolium salts can also be used as antifoggants. Heterocycles containing mercapto groups, e.g. B. mercaptobenzthiazoles, mercaptobenzimidazoles, mercaptotetrazoles, mercaptothiadiazoles, mercaptopyrimidines, these mercaptoazoles also containing a water-solubilizing group, for example a carboxyl group or sulfo group. Other suitable compounds are published in Research Disclosure No. 17643 (1978), Section VI.

The stabilizers can be added to the silver halide emulsions before, during or after their ripening. Of course, the compounds can also be added to other photographic layers which are assigned to a halogen silver layer.

Mixtures of two or more of the compounds mentioned can also be used.

The silver halide emulsions are usually chemically ripened, for example by the action of Gold compounds, other precious metal compounds, reducing agents and / or divalent sulfur compounds.

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.).

The photographic emulsions can be spectrally sensitized using methine dyes or other dyes. Particularly suitable dyes are cyanine dyes, merocyanine dyes and complex merocyanine dyes.

Sensitizers can be dispensed with if the intrinsic sensitivity of the silver halide is sufficient for a certain spectral range, for example the blue sensitivity of silver bromide.

Color photographic materials usually contain at least one red-sensitive, green-sensitive and blue-sensitive emulsion layer. These emulsion layers become non-diffusing monomers or polymers Color couplers assigned, which can be in the same layer or in a layer adjacent to it. Usually, cyan couplers are assigned to the red-sensitive layers, purple couplers to the green-sensitive layers and yellow couplers to the blue-sensitive layers. At least one of these layers preferably contains the combination of emulsion and DIR compound according to the invention. Both the at least one red-sensitive and at least one green-sensitive and at least one blue-sensitive layer preferably contain the emulsion / DIR compound combination according to the invention.

Color couplers for producing the blue-green partial color image are usually couplers of the phenol or α-naphthol type; preferably 2-ureidophenol compounds and 1,5-aminonaphthol compounds.

Color couplers for producing the yellow partial color image are generally couplers with an open-chain ketomethylene group, in particular couplers of the α-acylacetamide type; preferred classes of couplers are α-benzoylacetanilide couplers and α-pivaloylacetaninilide couplers, which are also known from the literature.

Color couplers for producing the purple partial color image are generally couplers of the 5-pyrazolone, indazolone or pyrazoloazole type; preferred classes of couplers are pyrazoloazole and arylaminopyrazolone compounds.

The color couplers can be 4-equivalent couplers, but also 2-equivalent couplers. Latter 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 those that are colorless, as well as those that have an intense intrinsic color that disappears during color coupling or is replaced by the color of the image dye produced (mask coupler), for example red-mask couplers consisting of a cyan coupler and one The white coupler, which binds via an oxygen atom and optionally a link in the coupling point and has an absorption in the range from 510 to 590 nm, gives essentially colorless products when reacted with color developer oxidation products. The 2-equivalent couplers also include the DIR couplers to be used according to the invention with a high coupling speed.

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 usually produced by polymerizing ethylenically unsaturated monomeric color couplers. However, they can also be obtained by polyaddition or polycondensation.

The couplers or other compounds can be incorporated into silver halide emulsion layers in such a way that first of the compound in question a solution, dispersion or emulsion is prepared and then added to the casting solution for the layer in question. The selection of the suitable solvent or dispersing agent depends on the solubility of the compound.

Methods for introducing compounds which are essentially insoluble in water by grinding processes are described, for example, in DE-A-2 609 741 and DE-A-2 609 742.

Hydrophobic compounds can also be introduced into the casting solution using high-boiling solvents, so-called oil formers. Corresponding methods are described for example in US-A-2 322 027, US-A-2 801 170, US-A-2 801 171 and EP-A-0 043 037.

Instead of the high-boiling solvents, oligomers or polymers, so-called polymeric oil formers, can be used.

The compounds can also be introduced into the casting solution in the form of loaded latices. Reference is made, for example, to DE-A-2 541 230, DE-A-2 541 274, DE-A-2 835 856, EP-A-0 014 921, EP-A-0 069 671, EP-A-0 130 115, U.S.-A-4,291,113.

The diffusion-resistant storage of anionic water-soluble Connections (eg of dyes) can also be made with the help of cationic polymers, so-called pickling polymers.

Suitable oil formers for other couplers and other compounds are e.g. Alkyl phthalates, phosphoric acid esters, citric acid esters, benzoic acid esters, alkylamides, fatty acid esters and trimesic acid esters.

Color photographic material typically comprises at least one red-sensitive emulsion layer, at least one green-sensitive emulsion layer and at least one blue-sensitive emulsion layer on a support. The order of these layers can be varied as desired. Couplers that form blue-green, purple and yellow dyes are usually incorporated into the red, green or blue-sensitive emulsion layers. However, different combinations can also be used.

Each of the light-sensitive layers can consist of a single layer or can also comprise two or more silver halide emulsion partial layers (DE-C-1 121 470). In this case, red-sensitive silver halide emulsion layers are often arranged closer to the support than green-sensitive silver halide emulsion layers and these are in turn closer than blue-sensitive layers, a non-light-sensitive yellow filter layer generally being located between green-sensitive layers and blue-sensitive layers.

With a suitably low intrinsic sensitivity of the green or Red-sensitive layers can be chosen without the yellow filter layer, other layer arrangements in which e.g. the blue-sensitive, then the red-sensitive and finally the green-sensitive layers follow.

The non-light-sensitive intermediate layers, which are generally arranged between layers of different spectral sensitivity, can contain agents which prevent undesired diffusion of developer oxidation products from one light-sensitive layer into another light-sensitive layer with different spectral sensitization.

If there are several sub-layers of the same spectral sensitization, these can differ with regard to their composition, in particular with regard to the type and amount of the silver halide grains. In general, the sublayer with higher sensitivity will be located further away from the support than the sublayer with lower sensitivity. Partial layers of the same spectral sensitization can be adjacent to one another or separated by other layers, for example by layers of different spectral sensitization. For example, all highly sensitive and all low-sensitive layers can be combined to form a layer package (DE-A 1 958 709, DE-A 2 530 645, DE-A 2 622 922).

The photographic material may further contain UV light absorbing compounds, whites, spacers, filter dyes, formalin scavengers and others.

Compounds that absorb UV light are intended on the one hand to protect the image dyes from fading by UV-rich daylight and, on the other hand, as filter dyes to absorb the UV light in daylight upon exposure and thus improve the color rendering of a film. Connections of different structures are usually used for the two tasks. Examples are aryl-substituted benzotriazole compounds (US-A 3 533 794), 4-thiazolidone compounds (US-A 3 314 794 and 3 352 681), benzophenone compounds (JP-A 2784/71), cinnamic acid ester compounds (US-A 3 705 805 and 3 707) 375), butadiene compounds (US-A 4 045 229) or benzoxazole compounds (US-A 3 700 455).

Ultraviolet absorbing couplers (such as α-naphthol type cyan couplers) and ultraviolet absorbing polymers can also be used. These ultraviolet absorbents can be fixed in a special layer by pickling.

Filter dyes suitable for visible light include oxonol dyes, hemioxonol dyes, styrene dyes, merocyanine dyes, cyanine dyes and azo dyes. Of these dyes, oxonol dyes, hemioxonol dyes and merocyanine dyes are used particularly advantageously.

Suitable whiteners are e.g. in Research Disclosure December 1978, page 22 ff, Unit 17 643, Chapter V.

Certain binder layers, in particular the most distant layer from the support, but also occasionally intermediate layers, especially if they are the most distant layer from the support during manufacture, may contain photographically inert particles of inorganic or organic nature, e.g. as a matting agent or as a spacer (DE-A 3 331 542, DE-A 3 424 893, Research Disclosure December 1978, page 22 ff, Unit 17 643, Chapter XVI).

The average particle diameter of the spacers is in particular in the range from 0.2 to 10 »m. The spacers are water-insoluble and can be alkali-insoluble or alkali-soluble, the alkali-soluble ones generally being removed from the photographic material in the alkaline development bath. Examples of suitable polymers are polymethyl methacrylate, copolymers of acrylic acid and methyl methacrylate and hydroxypropyl methyl cellulose hexahydrophthalate.

The binders of the material according to the invention, in particular if gelatin is used as the binder, are hardened with suitable hardeners, for example with hardeners of the epoxy type, the ethyleneimine type, the acryloyl type or the vinylsulfone type. Diazine, triazine or 1,2-dihydroquinoline series hardeners are also suitable.

The binders of the material according to the invention are preferably hardened with instant hardeners.

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

These hardening agents that react very quickly with gelatin are e.g. to carbamoylpyridinium salts, which are able to react with free carboxyl groups of the gelatin, so that the latter react with free amino groups of the gelatin to form peptide bonds and crosslink the gelatin.

• (a)
  
  worin

  R₁

  Alkyl, Aryl oder Aralkyl bedeutet,

  R₂

  die gleiche Bedeutung wie R₁ hat oder Alkylen, Arylen, Aralkylen oder Alkaralkylen bedeutet, wobei die zweite Bindung mit einer Gruppe der Formel

  

  verknüpft ist, oder

  R₁ und R₂

  zusammen die zur Vervollständigung eines gegebenenfalls substituierten heterocyclischen Ringes, beispielsweise eines Piperidin-, Piperazin- oder Morpholinringes erforderlichen Atome bedeuten, wobei der Ring z.B. durch C₁-C₃-Alkyl oder Halogen substituiert sein kann,

  R₃

  für Wasserstoff, Alkyl, Aryl, Alkoxy, -NR₄-COR₅, -(CH₂)_m-NR₈R₉, -(CH₂)_n-CONR₁₃R₁₄ oder

  

  oder ein Brückenglied oder eine direkte Bindung an eine Polymerkette steht, wobei

  R₄, R₆, R₇, R₉, R₁₄, R₁₅, R₁₇, R₁₈, und R₁₉

  Wasserstoff oder C₁-C₄-Alkyl,

  R₅

  Wasserstoff, C₁-C₄-Alkyl oder NR₆R₇,

  R₈

  -COR₁₀

  R₁₀

  NR₁₁R₁₂

  R₁₁

  C₁-C₄-Alkyl oder Aryl, insbesondere Phenyl,

  R₁₂

  Wasserstoff, C₁-C₄-Alkyl oder Aryl, insbesondere Phenyl,

  R₁₃

  Wasserstoff, C₁-C₄-Alkyl oder Aryl, insbesondere Phenyl,

  R₁₆

  Wasserstoff, C₁-C₄-Alkyl, COR₁₈ oder CONHR₁₉,

  m

  eine Zahl 1 bis 3

  n

  eine Zahl 0 bis 3

  p

  eine Zahl 2 bis 3 und

  Y

  O oder NR₁₇ bedeuten oder

  R₁₃ und R₁₄

  gemeinsam die zur Vervollständigung eines gegebenenfalls substituierten heterocyclischen Ringes, beispielsweise eines Piperidin-, Piperazin- oder Morpholinringes erforderlichen Atome darstellen, wobei der Ring z.B. durch C₁-C₃-Alkyl oder Halogen substituiert sein kann,

  Z

  die zur Vervollständigung eines 5- oder 6-gliedrigen aromatischen heterocyclischen Ringes, gegebenenfalls mit anelliertem Benzolring, erforderlichen C-Atome und

  X^⊖

  ein Anion bedeuten, das entfällt, wenn bereits eine anionische Gruppe mit dem übrigen Molekül verknüpft ist;

• (b)
  
  worin

  R₁, R₂, R₃ und X^⊖

  die für Formel (a) angegebene Bedeutung besitzen.

Suitable examples of instant hardeners are, for example, compounds of the general formulas

• (a)
  
  wherein

  R₁

  Means alkyl, aryl or aralkyl,

  R₂

  has the same meaning as R₁ or means alkylene, arylene, aralkylene or alkaralkylene, the second bond having a group of the formula

  

  is linked, or

  R₁ and R₂

  together represent the atoms required to complete an optionally substituted heterocyclic ring, for example a piperidine, piperazine or morpholine ring, the ring being able to be substituted, for example, by C₁-C₃alkyl or halogen,

  R₃

  for hydrogen, alkyl, aryl, alkoxy, -NR₄-COR₅, - (CH₂) _m -NR₈R₉, - (CH₂) _n -CONR₁₃R₁₄ or

  

  or a bridge link or a direct bond to a polymer chain, wherein

  R₄, R₆, R₇, R₉, R₁₄, R₁₅, R₁₇, R₁₈, and R₁₉

  Hydrogen or C₁-C₄ alkyl,

  R₅

  Hydrogen, C₁-C₄-alkyl or NR₆R₇,

  R₈

  -COR₁₀

  R₁₀

  NR₁₁R₁₂

  R₁₁

  C₁-C₄ alkyl or aryl, especially phenyl,

  R₁₂

  Hydrogen, C₁-C₄ alkyl or aryl, especially phenyl,

  R₁₃

  Hydrogen, C₁-C₄ alkyl or aryl, especially phenyl,

  R₁₆

  Hydrogen, C₁-C₄-alkyl, COR₁₈ or CONHR₁₉,

  m

  a number 1 to 3

  n

  a number 0 to 3

  p

  a number 2 to 3 and

  Y

  O or NR₁₇ mean or

  R₁₃ and R₁₄

  together those to complete an optionally substituted heterocyclic ring, for example one Piperidine, piperazine or morpholine ring are required atoms, which ring can be substituted, for example by C₁-C₃-alkyl or halogen,

  Z.

  the carbon atoms required to complete a 5- or 6-membered aromatic heterocyclic ring, optionally with a fused benzene ring, and

  X ^⊖

  mean an anion which is omitted if an anionic group is already linked to the rest of the molecule;

• (b)
  
  wherein

  R₁, R₂, R₃ and X ^⊖

  have the meaning given for formula (a).

The method for measuring the clutch speed is specified in DE-OS-2 704 797. The measuring methodology and the apparatus structure for determining the coupling rate constants of the couplers and DIR couplers used in the material according to the invention are described below.

It has been shown that the relative reaction rate constants of a coupler or DIR coupler determined according to one of the known methods can assume different values, depending on how these compounds are dispersed. It is conceivable that the same coupler can be used both as an aqueous alkaline solution or in the form of an emulsate using a so-called coupler solvent or oil-forming agent. Hydrophobic couplers can be used in the form of aqueous dispersions, which can optionally be prepared using low-boiling organic solvents, or in the form of the aforementioned emulsions. In the case of emulsifiers, the k value can also depend on the type and amount of solvent (oil former), as well as on the type of wetting agent and the size of the droplets. For this reason, it is desirable to use the effective reaction rate _constant (k _eff ) of the couplers in their respective dispersion form as a decision criterion for the usability of the couplers or DIR couplers in the sense of the present invention. It is therefore expedient to use the couplers in the same dispersion form in which they should also be used in the color photographic material in order to determine the relative reaction rate.

An electrochemical method has been developed which approximately determines the reactivity of dissolved or emulsified couplers in the form of a effective reaction rate _constants (k _eff [l / mol · sec]) allowed to be determined. A measure of the reactivity is the consumption of the developer oxidation product, which can be determined by measuring the redox potential in a "stopped flow" apparatus. The k _eff values given in the present description were determined by the method described below.

The required measuring equipment consists of two cylindrical, approximately 25 cm high storage containers, of which feed lines lead to a mixing chamber. The supply lines are equipped with check valves. A line leads from the mixing chamber via a solenoid valve, which is closed in the idle state and can be opened via a pulse generator, to a collecting vessel in which a negative pressure is generated and maintained. A measuring electrode is arranged between the mixing chamber and the collecting vessel, a reference electrode between the mixing chamber and a storage vessel. The electrodes are connected to a digital mV meter and a recorder. The sketch of such an apparatus is described in EP-A-329 016.

The solenoid valve is opened for a time t by means of the pulse generator. As a result of the pressure gradient between the collecting vessel and the storage containers, the liquids contained in the latter flow via the feed lines into the mixing chamber, where intensive mixing takes place. The mixture then reaches the collecting vessel via the solenoid valve. The first reservoir contains a Oxidizing agent, for example a 10⁻³ molar aqueous solution of K₃ [Fe (CN) ₆]. The second storage container contains a color developer, the coupler to be examined and means for setting the desired pH (buffer), all in aqueous solution. N¹-ethyl-N¹ (2-hydroxyethyl) -3-methyl-1,4-diammonium sulfate (monohydrate) = CD 4 was used as the color developer (concentration: 2x10⁻³ mol / l). The concentration of the coupler to be measured was 10⁻³ mol / l. Couplers that are not soluble in water can be used in the form of an emulsified from coupler, coupler solvent and hydrophilic binder, which is produced in a known manner. A pH of 10.2 was set using a carbonate / bicarbonate buffer.

The redox potential in the mixture is measured with the measuring electrode (platinum wire ⌀ 1 mm); An Ag / AgCl electrode (e.g. Argenthal cartridge) serves as the reference electrode, which in this version is located in the supply line of the second storage container to the mixing chamber, but can also be attached as usual next to the platinum electrode. The measured redox potential of the mixed solutions can be read using the digital mV meter and the chronological course of the time can be recorded using the recorder (compensation recorder, oscillograph, light dot line recorder).

For the time course of the change in the redox potential, the measured redox potential is plotted in mV (ordinate) as a function of time in sec (abscissa). t represents the opening time of the solenoid valve. From the angle α, the effective reaction rate _constant k _eff can be calculated using the following equation: $${\text{k}}_{\text{eff}}\text{=}\frac{\text{1}}{\text{K₀ · f}}{\text{(tgα}}_{\text{K}}\text{-tgα₀).}$$

k_eff

Reaktionsgeschwindigkeitskonstante [l/Mol·sec]

K₀

Anfangskonzentration an Kuppler (Mol/l)

f

elektrochemische Konstante $$\text{(f =}\frac{\text{R·T}}{\text{n·F}}\text{)}$$

α_K

Winkel α, erhalten wenn Kuppler zugegen ist

α₀

Winkel α, erhalten wenn kein Kuppler zugegen ist.

Mean it

k _eff

Reaction rate constant [l / mol · sec]

K₀

Initial concentration at coupler (mol / l)

f

electrochemical constant $$\text{(f =}\frac{\text{R · T}}{\text{n · F}}\text{)}$$

α _K

Angle α obtained when coupler is present

α₀

Angle α obtained when no coupler is present.

After the solutions have been poured into the storage containers, the mixing chamber and the supply and discharge lines are rinsed vigorously by opening the solenoid valve for a longer time, and the containers are then refilled to the original level. By briefly opening the solenoid valve the potential-time curve can then be recorded. The angle α between the time axis and the tangent to the measurement curve at the beginning of the reaction is determined, once with the coupler to be measured (α _K ) and once again without a coupler (α₀). The effective reaction rate _constant k _eff can be determined by inserting the two α values in the above equation.

Of course, the method can also be modified in many ways. So other color developers can be used and the reaction can be run at different pH values. To measure the reactivity of couplers that are very quickly oxidized by ferricyanide, the apparatus can be modified so that instead of one mixing chamber, a system of two series-connected mixing chambers is used, the developer oxidation product being produced in the first mixing chamber by mixing developer and ferricyanide together is then mixed with the coupler to be measured only in the second mixing chamber. The concentration on the developer oxidation product is mainly detected by the measuring electrode, which is probably the quinone diimine of the corresponding color developer used. For the basics of redox measurement, reference is made, for example, to J. Eggers "About the subsequent reactions in the oxidation of p-amino-N-dialkylanilines" in "Messages from the Agfa Research Laboratories", Volume III, page 73 (1961).

The couplers or DIR couplers are converted into an emulsifier with which the measurements described above are carried out in the following manner:

2 g of couplers are dissolved in 8 ml of a solvent mixture consisting of one part of dibutyl phthalate, three parts of ethyl acetate and 0.1 part of di-n-octyl sulfosuccinate (mannoxol) and emulsified in 37.5 g of 7.5% gelatin. The emulsate is then stirred for 6 min at about 1000 rpm, during which it heats up to a maximum of 60 ° C. and the ethyl acetate is then suctioned off in a water jet vacuum (200-300 mbar). Then make up to 60 g with water. The part corresponding to 1 mmol of coupler is removed from this solution and made up to 100 g with 4% by weight aqueous gelatin solution. 20 ml of solution are used for each measurement.

The coupling rate constants designated k in the further course relate to the effective reaction rate _constants k _eff determined with the method described above.

A

den Rest einer Verbindung, die bei Reaktion mit dem Oxidationsprodukt des Farbentwicklers die Gruppe -(L)_n-B in Freiheit setzt, insbesondere den Rest eines Kupplers, der bei Kupplung den Rest -(L)_n-B in Freiheit setzt.

B

den Rest eines Entwicklungsinhibitors, der aus der Gruppe -(L)_n-B freigesetzt wird,

L

ein zweiwertiges Bindeglied, das nach Lösen der Bindung A-L fähig ist, die Bindung L-B zu lösen und

n

0 oder 1 bedeuten.

The DIR compounds to be used according to the invention correspond in particular to the formula

A - (L) _n - B


wherein

A

the rest of a compound which, when reacted with the oxidation product of the color developer, releases the group - (L) _n -B, in particular the rest of a coupler which, when coupled, releases the rest - (L) _n -B.

B

the rest of a development inhibitor released from the group - (L) _n -B,

L

a divalent link which, after loosening the bond AL, is able to loosen the bond LB and

n

0 or 1 mean.

wobei

Y

O, S oder NR₆ und

R₂₀

H, einen unsubstituierten oder substituierten, geradkettigen, verzweigten oder cyclischen aliphatischen Rest, Halogen, -NHCOR₃₃, -OR₃₃,

oder -COOR₃₃

R₂₁

H, Halogen, einen unsubstituierten oder substituierten, geradkettigen, verzweigten oder cyclischen aliphatischen Rest, -SR₃₃, S-Aryl, -S-Hetaryl,

R₂₂

einen unsubstituierten oder substituierten, geradkettigen, verzweigten oder cyclischen aliphatischen Rest, -SR₃₃, Aryl oder Hetaryl,

R₂₃

Wasserstoff, einen unsubstituierten oder substituierten geradkettigen, verzweigten oder cyclischen aliphatischen Rest oder einen Arylrest,

R₂₄

einen unsubstituierten oder substituierten geradkettigen, verzweigten oder cyclischen aliphatischen Rest, -SR₃₃, -S-(CH₂)_n-COOR₃₄,

R₂₅

einen unsubstituierten oder substituierten geradkettigen, verzweigten oder cyclischen aliphatischen Rest oder unsubstituierte oder durch Hydroxy, Amino, Sulfamoyl, Carboxy oder Methoxycarbonyl substituierte Phenylgruppe,

R₂₆

einen unsubstituierten oder substituierten geradkettigen, verzweigten oder cyclischen aliphatischen Rest, Aryl, Hetaryl, -SR₃₃ oder eine Acylaminogruppe,

R₂₇

H, einen unsubstituierten oder substituierten geradkettigen, verzweigten oder cyclischen aliphatischen Rest, Aryl, eine Acylaminogruppe oder eine Benzylidenaminogruppe,

R₃₃

eine substituierten oder unsubstituierten geradkettigen, verzweigten oder cyclischen aliphatischen Rest,

R₃₄

einen substituierten oder unsubstituierten geradkettigen, verzweigten oder cyclischen aliphatischen Rest oder einen gegebenenfalls substituierten Arylrest

m

1 oder 2 bedeuten und

n

1 bis 4 bedeuten.

Preferred radicals B correspond to the following formulas:

in which

Y

O, S or NR₆ and

R₂₀

H, an unsubstituted or substituted, straight-chain, branched or cyclic aliphatic radical, halogen, -NHCOR₃₃, -OR₃₃,

or -COOR₃₃

R₂₁

H, halogen, an unsubstituted or substituted, straight-chain, branched or cyclic aliphatic radical, -SR₃₃, S-aryl, -S-hetaryl,

R₂₂

an unsubstituted or substituted, straight-chain, branched or cyclic aliphatic radical, -SR₃₃, aryl or hetaryl,

R₂₃

Hydrogen, an unsubstituted or substituted straight-chain, branched or cyclic aliphatic radical or an aryl radical,

R₂₄

an unsubstituted or substituted straight-chain, branched or cyclic aliphatic radical, -SR₃₃, -S- (CH₂) _n -COOR₃₄,

R₂₅

an unsubstituted or substituted straight-chain, branched or cyclic aliphatic radical or unsubstituted or substituted by hydroxyl, amino, sulfamoyl, carboxy or methoxycarbonyl,

R₂₆

an unsubstituted or substituted straight-chain, branched or cyclic aliphatic radical, aryl, hetaryl, -SR₃₃ or an acylamino group,

R₂₇

H, an unsubstituted or substituted straight-chain, branched or cyclic aliphatic radical, aryl, an acylamino group or a benzylidene amino group,

R₃₃

a substituted or unsubstituted straight-chain, branched or cyclic aliphatic radical,

R₃₄

a substituted or unsubstituted straight-chain, branched or cyclic aliphatic radical or an optionally substituted aryl radical

m

1 or 2 mean and

n

1 to 4 mean.

worin

k

1 oder 2

l

0, 1 oder 2,

R₂₈

Wasserstoff, Alkyl, Aryl, Hetaryl, Halogen, Nitro, Cyan, Alkylthio, Acylamino, Sulfamoyl, Alkoxycarbonylamino oder Amino,

R₂₉

Wasserstoff, Alkyl, Aryl oder Aralkyl,

R₃₀

Wasserstoff, Halogen, Alkyl, Aralkyl, Alkoxy, Anilino, Acylamino, Ureido, Cyan, Sulfonamido, Aryl oder Carboxy,

R₃₁

Wasserstoff, Alkyl, Aralkyl, Cycloalkyl oder Aryl,

M

-O- oder

R₃₂

Alkyl, Aralkyl, Aryl, Acyl, Hetaryl, Acylamino, -OR₃₅ oder -PO(OR₃₅)₂

R₃₅

Alkyl, Aryl oder Hetaryl,

Z

-O-, -S- oder

R₃₆

Wasserstoff, Alkyl, Aryl, Alkylsulfonyl oder Arylsulfonyl und

R₃₇

Wasserstoff, Alkyl oder Aryl bedeuten.

Preferred groups -LB correspond to the formulas:

wherein

k

1 or 2

l

0, 1 or 2,

R₂₈

Hydrogen, alkyl, aryl, hetaryl, halogen, nitro, cyano, alkylthio, acylamino, sulfamoyl, alkoxycarbonylamino or amino,

R₂₉

Hydrogen, alkyl, aryl or aralkyl,

R₃₀

Hydrogen, halogen, alkyl, aralkyl, alkoxy, anilino, acylamino, ureido, cyan, sulfonamido, aryl or carboxy,

R₃₁

Hydrogen, alkyl, aralkyl, cycloalkyl or aryl,

M

-O- or

R₃₂

Alkyl, aralkyl, aryl, acyl, hetaryl, acylamino, -OR₃₅ or -PO (OR₃₅) ₂

R₃₅

Alkyl, aryl or hetaryl,

Z.

-O-, -S- or

R₃₆

Hydrogen, alkyl, aryl, alkylsulfonyl or arylsulfonyl and

R₃₇

Is hydrogen, alkyl or aryl.

R₂₀

H, CH₃, Cl, Br, C₁-C₆-Alkoxy, C₁-C₆-Alkylcarbonylamino, Phenoxycarbonyl,

R₂₁

C₁-C₁₀-Alkylthio,

R₂₂

H, 2-Furyl,

R₂₃

H, C₁-C₄-Alkyl,

R₂₄

C₁-C₆-Alkylthio, C₁-C₈-Alkoxycarbonyl, C₁-C₆-Alkylcarbonyloxy-C₁-C₄-alkylenthio

R₂₅

Gegebenenfalls durch Di-C₁-C₄-Alkylamino substituiertes C₁-C₆-Alkyl, gegebenenfalls durch Hydroxy, C₁-C₄-Alkyl, Methoxycarbonyl, Aminosulfonyl oder Chlorethoxycarbonyl mono- oder di-substituiertes Phenyl,

R₂₆

C₁-C₆-Alkyl, Amino, 2-Furyl,

R₂₇

H, C₁-C₆-Alkylcarbonylamino, oder

R₂₈

NO₂,

R₂₉

C₁-C₄-Alkyl,

R₃₀

C₁-C₂₀-Alkyl oder Phenyl,

R₃₁

H, C₁-C₄-Alkyl,

R₃₂

gegebenenfalls durch Chlor substituiertes Phenyl,

R₃₇

Phenyl, Nitrophenyl,

Z

Sauerstoff.

The substituents particularly preferably have the following meaning:

R₂₀

H, CH₃, Cl, Br, C₁-C₆-alkoxy, C₁-C Alkyl-alkylcarbonylamino, phenoxycarbonyl,

R₂₁

C₁-C₁₀ alkylthio,

R₂₂

H, 2-furyl,

R₂₃

H, C₁-C₄ alkyl,

R₂₄

C₁-C₆-alkylthio, C₁-C₈-alkoxycarbonyl, C₁-C₆-alkylcarbonyloxy-C₁-C₄-alkylene thio

R₂₅

C₁-C₆-alkyl optionally substituted by di-C₁-C₄-alkylamino, optionally mono- or di-substituted phenyl by hydroxy, C₁-C₄-alkyl, methoxycarbonyl, aminosulfonyl or chloroethoxycarbonyl,

R₂₆

C₁-C₆ alkyl, amino, 2-furyl,

R₂₇

H, C₁-C₆ alkylcarbonylamino, or

R₂₈

NO₂,

R₂₉

C₁-C₄ alkyl,

R₃₀

C₁-C₂₀ alkyl or phenyl,

R₃₁

H, C₁-C₄ alkyl,

R₃₂

phenyl optionally substituted by chlorine,

R₃₇

Phenyl, nitrophenyl,

Z.

Oxygen.

wobei R₃₈ eine aliphatische, eine aromatische, eine heterocyclische Gruppe oder

darstellt, l die Werte 0,1 oder 2 und p die Werte 0, 1, 2 oder 3 annehmen kann.The link L can also be split off by reaction with the oxidized product of a developer substance. Typical examples of such links are given in the following general DIR coupler structures.

wherein R₃₈ is an aliphatic, an aromatic, a heterocyclic group or

represents, l can have the values 0, 1 or 2 and p can have the values 0, 1, 2 or 3.

All those DIR couplers are suitable for the material according to the invention, the coupling rate constant of which is k 10 2 · 10³, preferably ≧ 5 · 10³ [l / mol · sec] at the pH of the color developer.

Examples for sufficiently fast (coupling rate constant k ≧ 2 · 10³ [l / mol · sec.] At pH 10.2) and for too slow DIR couplers (k ≦ 2 · 10³ l / mol · sec] can be found for example in the following tables, without the DIR couplers which can be used for the material according to the invention being restricted to the substances listed there.

• a) Gelbkuppler vom Benzoylacetanilidtyp und/oder Pivaloylacetanilidtyp und Chinazolinon-acetanilidtyp
• b) Purpurkuppler von Pyrazolo-azoltyp und Acylaminopyrazolontyps
• c) Blaugrünkuppler vom 2-Ureidophenoltyp und/oder 5-Amino-1-naphtholtyp
• d) Rotmaskenkuppler mit O-Fluchtgruppe der allgemeinen Formel:
  
          Cp-O-L_(0-1)-Dye
  
  

in der

Cp

Blaugrünkuppler

L

Bindeglied

Dye

Farbstoff mit λ_max zwischen 510-590 nm

bedeuten.

Fast DIR couplers of the following classes are preferred for the material according to the invention:

• a) Yellow coupler of the benzoylacetanilide type and / or pivaloylacetanilide type and quinazolinone acetanilide type
• b) Purple couplers of pyrazolo-azole type and acylaminopyrazolone type
• c) Teal couplers of the 2-ureidophenol type and / or 5-amino-1-naphthol type
• d) red mask coupler with O-escape group of the general formula:
  
  Cp-OL _(0-1) dye
  
  

in the

Cp

Teal coupler

L

Link

Dye

Dye with λ _max between 510-590 nm

mean.

DIR compounds whose inhibitors are highly diffusible are preferably suitable for the material according to the invention.

A method for determining the diffusibility of the inhibitors split off from the DIR couplers is described in EP-A-115,302.

The diffusibility D _f is determined for the purposes of the present invention according to the following rule:

Multilayer test materials A and B were made as follows:

Test material A

Schicht 1

rotsensibilisierte Silberhalogenidemulsion der angegebenen Art aus 4,57 g AgNO₃ 0,754 g Blaugrünkuppler K, gelöst in 0,6 g Dibutylphthalat und dispergiert 0,603 g Gelatine

Schicht 2

unsensibilisierte Silberhalogenidemulsion aus 2,63 g AgNO₃
2,63 g AgNO₃
0,38 g Weißkuppler L
1,17 g Gelatine

Schicht 3

Schutzschicht mit
1,33 g Gelatine

Schicht 4

Härtungsschicht mit
0,82 g Gelatine
0,54 g Härter der Formel

The following layers are applied to a transparent cellulose triacetate support in the order given.
The quantities refer to 1 m². The corresponding amount of AgNO₃ is given for the silver halide application. The silver halide emulsions are stabilized with 0.5 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindene per 100 g of AgNO₃.
Silver halide emulsion: Silver bromide iodide emulsion with 7 mol% iodide, average grain diameter 0.5 »m, cube-shaped crystals with rounded corners.

Layer 1

red-sensitized silver halide emulsion of the specified type from 4.57 g AgNO₃ 0.754 g cyan coupler K, dissolved in 0.6 g dibutyl phthalate and dispersed 0.603 g gelatin

Layer 2

unsensitized silver halide emulsion from 2.63 g AgNO₃
2.63 g AgNO₃
0.38 g white coupler L
1.17 g gelatin

Layer 3

Protective layer with
1.33 g gelatin

Layer 4

Hardening layer with
0.82 g gelatin
0.54 g hardener of the formula

Teal Coupler K

White coupler L

Test material B

A test material B was also produced in the same way, but with the change compared to test material A that layer 2 is composed
0.346 g white coupler and
0.900 g gelatin.

The test materials A and B are exposed in a dark room under room lighting with a 100 watt incandescent lamp at a distance of 1.5 m and an exposure time of 15 min.

Development is carried out as described in "The Journal of Photography", 1974 , pages 597 and 598, with the change that the developer has been diluted with 20% by volume.

Modified developers containing the development inhibitor to be tested are prepared in such a way that a 0.02 molar solution of the inhibitor in a methanol / water mixture (8: 2), which, if necessary, NaOH up to a pH of 9 contains, the developer is added and results in a 20 vol% diluted developer by adding water.

Test materials A and B are each developed in the developer not containing the inhibitor and processed in the further steps.

The resulting blue green densities are measured with a densitometer.

worin bedeuten:

D_Ao, D_Bo

Farbdichte der Testmaterialien A bzw. B nach Entwicklung in dem angegebenen Entwickler ohne Inhibitorzusatz

D_A, D_B

Farbdichte der Testmaterialien A bzw. B nach Entwicklung in dem angegebenen Entwickler, der den Inhibitor in einer solchen Konzentration enthält, daß folgende Gleichung gilt: $$\frac{{\text{D}}_{\text{Bo}}{\text{-D}}_{\text{B}}}{{\text{D}}_{\text{Bo}}}\text{= 0,5}$$

The diffusibility D _f is determined according to the following equation: $${\text{D}}_{\text{f}}\text{=}\frac{{\text{(D}}_{\text{Ao}}{\text{- D}}_{\text{A}}{\text{) / D}}_{\text{Ao}}}{{\text{(D}}_{\text{Bo}}{\text{- D}}_{\text{B}}{\text{) / D}}_{\text{Bo}}}$$

in which mean:

D _Ao , D _Bo

Color density of test materials A and B after development in the specified developer without the addition of inhibitor

D _A , D _B

Color density of test materials A and B after development in the specified developer, which contains the inhibitor in such a concentration that the following equation applies: $$\frac{{\text{D}}_{\text{Bo}}{\text{-D}}_{\text{B}}}{{\text{D}}_{\text{Bo}}}\text{= 0.5}$$

Preferred inhibitors have a D _f ≧ 0.4.

Inhibitors of high diffusibility to be used according to the invention are given below, the DIR compounds which can be used not being restricted to these inhibitors.

The color photographic silver halide materials according to the invention are processed after image-wise exposure by developing, bleaching and fixing.

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) ethylaniline sulfate hydrate; 4-amino-3-methyl-N-ethyl-N-β-hydroxyethylaniline sulfate; 4-amino-N-ethyl-N- (2-methoxyethyl) -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 515 ff.

The pH of the color developer is in the range from 8 to 13, preferably from 9 to 12 and particularly preferably from 9.5 to 11.5. The temperature is in the range from 25 to 50 ° C, preferably from 30 to 50 ° C and particularly preferably 35 to 45 ° C, in order to support the shortened development time.

A color developer is preferably used which contains no or less than 1.0 mg / l iodide ions. Color developers containing no or less than 50 mg / l bromide ions are particularly preferred.

The development time is 15 seconds to 150 seconds, preferably 20 to 120 seconds and particularly preferably 30 seconds to 90 seconds.

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. Fe 3 salts and Fe 3 complex salts such as ferricyanides, dichromates, water-soluble cobalt complexes etc. Particularly preferred are iron III complexes of aminopolycarboxylic acids, in particular of ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, N-hydroxyethylethylenediaminetriacetic acid, and alkyliminodicarboxylic acid, alkyliminodicarboxylic acid. Persulphates are also suitable as bleaching agents.

The preparation of some emulsions (according to the invention and for comparison) is described below. Emulsions 2 to 4 on pages 3 and 4 are obtained analogously.

Emulsion 1 (Core-Shell AgCl _0.7 Br _0.3 emulsion with AgBr in the core)

In 9 l of an aqueous solution containing 350 g of gelatin, 50 g of NaCl and 120 g of methionine, 1000 ml of 0.8 molar AgNO₃ solution and 1000 ml of 0 were at 65 ° C. and pH 4.4 with stirring according to the double inlet method, 8 molar KBr solution was added at an inlet rate of 35 ml / min each. Subsequently, 3450 ml of 2-molar AgNO₃ solution and 3450 ml of 2-molar KBr solution were added in 16 minutes after the double inlet process, the silver and halide solution being regulated in such a way that the final inlet speed was 3 times higher than the initial speed. After heating at 65 ° C. for 15 minutes, the solution was adjusted to 45 ° C. Then 6000 ml of 3 molar AgNO₃ solution and 6000 ml of 3 molar NaCl solution were added in 25 minutes by the double enema method.

The emulsion was flocculated; washed; redispersed with a solution of 1630 g of gelatin in 8 l of water and adjusted to pH 6.0 and pAg 8.

The emulsion was chemically ripened at 55 ° C. with 5 »mol sodium thiosulfate / mol Ag, 5» mol tetrachloroauric acid and 500 »mol potassium thiocyanate / mol Ag to maximum sensitivity.

The emulsion was homodisperse and composed of two zones.
Zone 1 (core) made of AgBr (30 mol%)
Zone 2 (shell) made of AgCl (70 mol%).

The silver halide crystals were cubic. The most common value of the diameter of the same-volume sphere was 1.6 »m, with 90% of the crystals having a diameter> 1.45» m and <1.8 »m.

Emulsion 5 (Core-Shell AgCl _0.7 Br _0.3 emulsion with AgCl in the core)

In 9 liters of an aqueous solution containing 350 g of gelatin, 50 g of NaCl and 30 g of methionine, 1500 ml of 1.35 molar AgNO₃ solution and 1500 ml of 1 were at 55 ° C. and pH 4.4 with stirring by the double inlet method, 35 molar NaCl solution was added at an inlet rate of 55 ml / min each. Subsequently, 5400 ml of 3 molar AgNO₃ solution and 5400 ml of 3 molar NaCl solution were added over the course of 20 minutes using the double enema method. After 10 minutes at 55 ° C at this temperature, 2600 ml of 3 molar AgNO₃ solution and 2600 ml of 3 molar KBr solution were added at a constant running-in rate in 10 minutes. As in the case of emulsion 1, the emulsion was flocculated, washed, redispersed and chemically ripened to maximum sensitivity.

The emulsion was homodisperse and composed of two zones.
Zone 1 (core) made of AgCl (70 mol%)
Zone 2 (shell) made of AgBr (30 mol%)

The silver halide crystals were cubic. The most common sphere diameter was 1.56 »m, with 90% of the crystals having a diameter> 1.50» m and <1.74 »m.

Emulsion 6 (AgCl _0.7 Br _0.3 with an AgBr content falling from the inside to the outside)

In the following, a silver chloride bromide emulsion made up of 11 zones was produced by double and triple inlet processes, which contained 30 mol% AgBr in the core and 70 mol% AgCl which is not present in the center of the silver halide crystals.

To 13.5 liters of an aqueous solution containing 230 g of gelatin, 0.8 g of potassium bromide and 20 g of methionine were 1060 ml of 0.5 molar AgNO₃ solution and 1060 ml of 0 at 63 ° C and pH 6.3 with stirring , 5 molar KBr solution added by the double enema method with an enema rate of 100 ml / min each. After 20 minutes of tempering at 63 ° C., a homodisperse cubic AgBr emulsion was formed, the crystals of which had an edge length of 0.4 »m.

770 g of gelatin, 50 g of NaCl and 80 g of methionine were added to this starting emulsion. Then 8000 ml of 2 molar AgNO₃ solution; 4000 ml of 2 molar KBr solution and 4000 ml of 2 molar NaCl solution were added, the AgNO₃ solution being regulated in 9 steps in 45 steps with increasing inlet speed so that the end inlet speed was 5 times higher than the start inlet speed. The inlet speed of the KBr solution was regulated so that the KBr / AgNO₃ molar ratio, according to the order of the inlet stage of the AgNO₃ solution, was varied from 0.9 to 0.1 in 9 steps. The inlet speed of the NaCl solution was controlled so that the total number of moles of KBr and NaCl was equal to that of AgNO₃.

Subsequently, 6820 ml of 3 molar AgNO₃ solution and 6820 ml of 3 molar NaCl solution were added over the course of 15 minutes using the double inlet process.

As in the case of emulsion 1, the emulsion was flocculated, washed, redispersed and chemically ripened to maximum sensitivity.

The emulsion, counted from the inside out, was composed of 11 zones as follows.

The silver halide crystals were cube-shaped with rounded corners. The most common sphere diameter was 1.84 »m, with 90% of the crystals having a diameter> 1.50» m and <2.10 »m.

Emulsion 7 (AgCl _0.7 Br _0.3 with homogeneous halide distribution; comparison emulsion )

1500 ml of 1.35 molar AgNO 3 solution and 1500 ml of 1 were in 9 liters of an aqueous solution containing 350 g of gelatin, 50 g of NaCl and 60 g of methionine at 55 ° C and pH 4.4 with stirring according to the double inlet method, 35 molar halide solution (70 mol% NaCl and 30 mol% KBr) were added at a rate of 55 ml / min each. After 10 minutes tempering at 55 ° C was 8000 ml of 3 molar AgNO₃ solution and 8000 ml of 3 molar halide solution (70 mol% NaCl and 30 mol% KBr) after 45 minutes with the double enema process with increasing dosage added that the final entry rate of the silver ion and halide solution was 4 times higher than the initial entry rate. The emulsion was flocculated, washed, redispersed with a solution of 1630 g of gelatin in 8 l of H₂O, adjusted to pH 6.0 and pAg 8.

As in the case of emulsion 1, the emulsion was flocculated, washed, redispersed and chemically ripened to maximum sensitivity.

The emulsion was homodisperse and homogeneously composed of 70 mol% AgCl and 30 mol% AgBr. The silver halide crystals were cubic. The most common sphere diameter was 1.8 »m, with 90% of the crystals having a diameter> 1.75» m and <1.85 »m.

Examples example 1

The following layers were applied to a transparent cellulose triacetate support in the order given here (quantities per m²):

For the silver halide application, the corresponding amounts of AgNO₃ are given.

All silver halide emulsions of this material were stabilized with 0.5 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindene per 100 g of AgNO₃.

Layer structure 1A

1st layer

(Green sensitive layer)
2.50 g AgNO₃ of the spectrally green sensitized emulsion 7
1.13 g gelatin
0.62 g purple coupler M1
0.62 g tricresyl phosphate

2 layer

(Protective and hardening layer)
1.14 g gelatin
0.40 g hardener

Layer structure 1B

like layer structure 1A, but additionally 0.054 g DIR-1 in the first layer

Layer structure 1C

like layer structure 1A, but additionally 0.051 g DIR-2 in the first layer

Layer structure 1D

like layer structure 1A, but 2.5 g AgNO₃ of the green sensitized emulsion 5 instead of 2.5 g AgNO₃ of the emulsion 7

Layer structure 1E

as layer structure 1B, but with 2.5 g of AgNO₃ the green sensitized emulsion 5 instead of 2.5 g of AgNO₃ emulsion 7.

Layer structure 1F

as layer structure 1C, but with 2.5 g of AgNO₃ the green-sensitized emulsion 5 instead of 2.5 g of AgNO₃ the emulsion 7.

Layer structure 1G

like layer structure 1A, but with 2.5 g AgNO₃ of the green sensitized emulsion 1 instead of 2.5 g AgNO₃ of the emulsion 7.

Layer structure 1H

as layer structure 1B, but with 2.5 g of AgNO₃ the green sensitized emulsion 1 instead of 2.5 g of AgNO₃ the emulsion 7.

Layer structure 1I

like layer structure 1C, but with 2.5 g of AgNO₃ of the green sensitized emulsion 1 instead of 2.5 g of AgNO₃ of the emulsion 7.

Layer structure 1H and 1I are according to the invention

Compounds used in Example 1:

The decrease in gradation generated by using DIR couplers was determined as normalized inhibition I on these nine layer structures 1A to 1I. It is $$\text{I =}\frac{\text{γ without DIR - γ with DIR}}{\text{γ without DIR}}$$

Large inhibitions are necessary to achieve high sharpness through edge effects. On the other hand, a decrease in sensitivity when using DIR couplers is undesirable. The size of the "edge effects" was determined according to TH James, The Theory of the Photographic Process, 4th ed. Macmillan Publ. Co. Inc. New York, London (1977) pp. 609-614 by means of X-ray radiation: one each Sample of the layer structures 1 A to 1 I was exposed to both a macro field and a 30 »m wide slit with the same X-ray dose. The samples were then processed using the color negative method known from "The British Journal of Photography", 1974, pages 597 and 598. The density difference measured on these samples between the gap (= micro density) and the macro field (= macro density) at that X-ray dose, which gives the macro density 0.8 via fog, is used in Table 1 as a measure of the size of the edge effect.

High edge effects are required for good detail reproduction.

Table 1 shows the values for the decrease in sensitivity ΔE by using DIR couplers compared to the sample without DIR couplers, the inhibition I and the edge effect K.

Example 2 Layer structure 2A

1st layer

(Red sensitive layer)
3.80 g AgNO₃ of the spectrally red-sensitized emulsion 7
2.66 g gelatin
0.95 g cyan coupler C 1
0.95 g tricresyl phosphate

2 layer

(Separation layer)
1.50 g gelatin
0.80 g white coupler W1

3 layer

(Green sensitive layer)
3.80 g AgNO₃ of the spectrally green sensitized emulsion 7
2.85 g gelatin
0.95 g purple coupler M1
0.95 g tricresyl phosphate

4th layer

(Protective and hardening layer)
1.14 g gelatin
0.52 g hardener

Layer structure 2B

like layer structure 2A, but in the 1st layer 3.8 g AgNO₃ of the red sensitized emulsion 1 instead of 3.8 g AgNO₃ the emulsion 7 and in the 3rd layer 3.8 g AgNO₃ of the green sensitized emulsion 1 instead of 3.8 g AgNO₃ the emulsion 7.

Layer structure 2C

like layer structure 2A, but additionally in the 1st and 3rd layer 0.054 g DIR-1 each

Layer structure 2D

Like layer structure 2B, but additionally in the 1st and 3rd layer 0.054 g DIR-1

Layer structure 2E

like layer structure 2A, but additionally in the 1st and 3rd layer 0.055 g DIR-3 each

Layer structure 2F

like layer structure 2B, but additionally in the 1st and 3rd layer 0.055 g DIR-3 each

Layer structure 2D is according to the invention

   x = 40 %   y = 60 %Compounds used for the first time in Example 2:

x = 40% y = 60%

The interimage effect (IIE) of cyan and purple which improves the color quality is also increased by the combination (2 D) according to the invention. The interimage effect is entered in Table 2 by what percentage of purple gradation and blue-green gradation is greater with green exposure or red exposure than with white exposure at the point on the color density curve where the color density obtained with white exposure is 1.0 via fog.

Table 2 shows the values for the edge effect and interim effect.

Example 3 Layer structure 3A

1st layer

(Red sensitive layer)
3.80 g AgNO₃ of the spectrally red-sensitized emulsion 1
2.70 g gelatin
0.95 g cyan coupler C1
0.95 g tricresyl phosphate

2 layer

(Separation layer)
1.5 g gelatin
0.80 g white coupler W1

3 layer

(Green sensitive layer)
3.5 g AgNO₃ of the spectrally green sensitized emulsion 1
2.6 g gelatin
0.95 g purple coupler M1
0.95 g tricresyl phosphate

4th layer

(Separation layer)
1.50 g gelatin
0.80 g white coupler W1

5th layer

(Yellow filter layer)
0.36 g gelatin
0.09 g yellow colloidal silver sol

6th layer

(Blue sensitive layer)
3.8 g AgNO₃ of the spectrally blue-sensitized emulsion 1
2.6 g gelatin,
1.0 g yellow coupler Y1
1.0 g tricresyl phosphate

7th layer

(Protective layer)
1.50 g gelatin

8th layer

(Hardening layer)
1.14 g gelatin
0.75 g hardener

Layer structure 3B

like layer structure 3A, however
in the 1st layer an additional 53 mg DIR-1,
in the 3rd layer an additional 49 mg DIR-1 and
in the 6th layer an additional 55 mg DIR-1.

Substances used for the first time in Example 3

A gray wedge is exposed on the samples. Processing was carried out in accordance with Tables 3 and 4.

Color developer

Bleach-fixer

Color developer

Bleach-fixer

The edge effect K was determined at 1.0 macro density using fog.

Example 4 Layer structure 4A

1st layer

(Green sensitive layer)
1.50 g AgNO₃ of the spectrally green sensitized emulsion 1
1.13 g gelatin
0.62 g purple coupler M1
0.62 g tricresyl phosphate

2 layer

(Protective and hardening layer)
1.14 g gelatin
0.40 g hardener

Layer pickings 4B to 4G

Like layer structure 4A, but additionally in the 1st layer 2 mmol of the DIR compounds DIR-1, DIR-2, DIR-3, DIR-4, DIR-5 and DIR-6.

Compounds used for the first time in Example 4:

Table 5 shows the measured inhibitions I:

Claims (7)

1. Colour photographic silver halide material having at least one silver halide emulsion layer which contains at least one colour coupler, in which layer the silver halide grains contain from 40 to 90 mol.% of AgCl and at least two zones of differing halide composition, the outer zone having a chloride content at least 10 mol.% higher than the inner zone, and with which a DIR compound is associated, the reaction of which with the oxidised colour developer has a reaction rate constant k > 2000 [l/mol·s].
2. Colour photographic silver halide material according to claim 1, in which the silver halide grains are AgBrCl grains.
3. Colour photographic silver halide material according to claim 1, in which the silver halide emulsion is monodisperse, wherein at least 70% of the emulsion grains have a diameter of a sphere of identical volume, which diameter is between 0.8 times and 1.9 times the most frequent sphere diameter.
4. Colour photographic silver halide material according to claim 1 having at least one red-sensitive emulsion layer containing at least one cyan coupler, at least one green-sensitive silver halide emulsion containing at least one magenta coupler and at least one blue-sensitive silver halide emulsion layer containing at least one yellow coupler, in which material at least one silver halide emulsion layer has a silver halide emulsion and a DIR compound according to claim 1.
5. Colour photographic silver halide material according to claim 4, wherein at least one red-sensitive, at least one green-sensitive and at least one blue-sensitive silver halide emulsion layer contains a silver halide emulsion and a DIR coupler according to claim 1.
6. Colour photographic silver halide material according to claim 1, characterised in that the reaction rate constant k of the DIR compound is > 5 · 10³ [l/mol·s]
7. Colour photographic silver halide material according to claim 1, characterised in that the inhibitors of the DIR compounds have a diffusibility of ≧ 0.4.