EP0377889B1 - Silver halide recording material - Google Patents

Description

The invention relates to a silver halide recording material with improved latent image stabilization.

When a silver halide photographic material is exposed, a so-called latent image is formed, which is only developed when the actual silver image is developed. This latent image is damaged if there are longer periods between exposure and development, and must therefore be protected from degradation by adding latent image stabilizers to the photographic material.

A number of latent image stabilizers have been proposed, e.g. B. DE 2 325 039, 2 335 093, 2 304 322, 3 308 203, GB 1 308 777, 1 458 197, US 4 334 014, 4 378 426, JA 50/94918, 57/100 424 and JP 116 167 .

These latent image stabilizers have the disadvantage that, depending on the amount added per mole of silver halide and depending on the pH and pAg of the emulsion layer during storage of the exposed emulsion, they either slow the decline in the latent image insufficiently or else cause the latent image to be satisfactory Dimensions is stabilized, but the fog of the photographic emulsion increases during storage to an increased extent.

It is known to increase the fog caused by these latent image stabilizers by increasing amounts of antifoggants such as 5-methyl-benzotriazole, 1-phenyl-5-mercapto-tetrazole, benzimidazole, 2,5-dimercapto-1,3,4-thiodiazole, etc. inhibit without canceling the latent image stabilization.

A disadvantage of this latent image stabilization method, however, is that the antifoggants must be used in amounts which significantly reduce the sensitivity of the emulsion.
This also applies to the combination of colorless benzothiazolium compound and 1-phenyl-5-mercaptotetrazole known from US Pat. No. 3,954,478.

It is also known to prepare emulsions whose latent image increases and does not weaken under practically occurring storage conditions, ie the sensitivity of these emulsions increases for a time after exposure to a limit value before it gradually decreases again. In the case of emulsions of this type, exposure also forms, in addition to the latent image nuclei, sub-nuclei which become too during storage agglomerate developable latent image nuclei and thus increase the number of developable emulsion grains, as a result of which the loss of sensitivity resulting from the corrosion of latent image nuclei is not only compensated for for a time, but even overcompensated.

However, such emulsions necessarily have an unfavorable sensitivity-granularity ratio, since additional light quanta are used for the formation of the sub-nuclei. Emulsions with the smallest possible quantum requirement and correspondingly good sensitivity-granularity ratio form only latent image nuclei during the exposure, not sub nuclei, so that when the exposed emulsion is stored, the sensitivity can only decrease and measures must be taken which slow the rate of corrosion of the latent image nuclei sufficiently.

It was therefore an object of the present invention to find measures which protect the latent image nuclei from corrosion and reduce the sensitivity as little as possible without causing an unusually high increase in fog during storage.

It has now been found that latent image stabilization of the desired type can be achieved by using at least one certain heterocyclic mercapto compound and at least one colorless thiazolium, selenazolium or tellurazolium compound for the latent image stabilization. Colorless thiazolium, selenazolium or tellurazolium compounds are understood to mean those which are in water or an organic Solvent dissolved have no absorption maximum in the range of 400 to 700 nm.

worin

R₁

Wasserstoff; eine Alkylgruppe mit bis zu 9 C-Atomen, die substituiert sein kann, beispielsweise durch Chlor, Brom, Fluor, Cyan, Hydroxy, Alkoxy wie Methoxy, Alkylthio, Carboxy, Alkoxycarbonyl, Carbonamido; eine Arylgruppe wie Phenyl; eine Aralkylgruppe wie Benzyl; eine Cycloalkylgruppe wie Cyclohexyl; oder eine heterocyclische Gruppe wie Furyl, Thienyl, Pyridyl;

R₂

Wasserstoff; Alkyl, das substituiert oder unsubstituiert sein kann; Alkenyl wie Allyl; Aryl wie Phenyl; oder eine Aminogruppe - NR₄R₅

R₃

Wasserstoff oder eine bei der Entwicklung abspaltbare Gruppe wie -COR₉ oder -COOR₁₀;

R₄, R₅

R₁ oder eine Gruppe -COR₆, -CONHR₇ oder -COOR₈;

R₆

Alkyl- oder Cycloalkylgruppe mit bis zu acht C-Atomen, die substituiert oder unsubstituiert sein kann, beispielspielsweise Methyl, Butyl, Cyclohexyl, Methoxymethyl, Methylmercaptomethyl; Allyl; Benzyl; Aryl wie Phenyl, 4-Chlorphenyl, 4-Sulfonphenyl;

R₇

Wasserstoff oder R₆;

R₈, R₉, R₁₀

Alkyl- oder Cycloalkylgruppe, die substituiert oder unsubtituiert sein kann, mit bis zu 8 C-Atomen wie Methyl, Ethyl, Isopropyl; Aryl wie Phenyl bedeuten

oder der Formel (II)

worin Z die restlichen Glieder zur Vervollständigung eines gegebenenfalls substituierten Benzoxazol-, Naphtoxazol, Naphtoxazin- oder phenyl-substituierten Oxazolringes, der im aromatischen Teil wenigstens eine saure Gruppe enthält, bedeutet, entspricht.The invention thus relates to a light-sensitive silver halide recording material having a support and at least one light-sensitive silver halide emulsion layer which contains both at least one heterocyclic mercapto compound and at least one thiazolium, selenazolium or tellurazolium compound, characterized in that the heterocyclic mercapto compound of the formula (I)

wherein

R₁

Hydrogen; an alkyl group with up to 9 carbon atoms, which can be substituted, for example by chlorine, bromine, fluorine, cyano, hydroxy, alkoxy such as methoxy, alkylthio, carboxy, alkoxycarbonyl, carbonamido; an aryl group such as phenyl; an aralkyl group such as benzyl; a cycloalkyl group such as cyclohexyl; or a heterocyclic group such as furyl, thienyl, pyridyl;

R₂

Hydrogen; Alkyl, which may be substituted or unsubstituted; Alkenyl such as allyl; Aryl such as phenyl; or an amino group - NR₄R₅

R₃

Hydrogen or a group which can be split off during development, such as -COR₉ or -COOR₁₀;

R₄, R₅

R₁ or a group -COR₆, -CONHR₇ or -COOR₈;

R₆

Alkyl or cycloalkyl group with up to eight carbon atoms, which can be substituted or unsubstituted, for example methyl, butyl, cyclohexyl, methoxymethyl, methyl mercaptomethyl; Allyl; Benzyl; Aryl such as phenyl, 4-chlorophenyl, 4-sulfonphenyl;

R₇

Hydrogen or R₆;

R₈, R₉, R₁₀

Alkyl or cycloalkyl group, which can be substituted or unsubstituted, with up to 8 carbon atoms, such as methyl, ethyl, isopropyl; Aryl like phenyl mean

or of formula (II)

where Z is the remaining members to complete an optionally substituted benzoxazole, naphthoxazole, naphthoxazine or phenyl-substituted oxazole ring which contains at least one acidic group in the aromatic part.

Examples of compounds of the formula I are:

Examples of ring systems of the formula II are oxazole, benzoxazole, naphth [1,2: d] oxazole, naphth [2,3: d] oxazole, naphth [2,1: d] oxazole, naphth [1,8: de] oxazine .

Suitable acidic groups are -COOH, -SO₃H, -SO₂NHR with R = H, alkyl, aryl.

Alkyl, halogen, ether and ester groups are possible as further substituents of the compounds of formula II.

worin

R₁₁ bis R₁₄

gleich oder verschieden sind und Wasserstoff oder Alkyl, insbesondere mit 1 bis 4 C-Atomen, bedeuten und wobei zwei der Substituenten R₁₁-R₁₄ zusammen den Rest zur Vervollständigung eines Ringes, insbesondere eines ankondensierten Phenylringes bedeuten können,
mit der Maßgabe, daß wenigstens einer der Substituenten R₁₁-R₁₄ einen sauren Substituenten enthält oder ein saurer Substituent ist.

Preferred compounds within the formula II correspond to the formula III

wherein

R₁₁ to R₁₄

are identical or different and are hydrogen or alkyl, in particular having 1 to 4 carbon atoms, and where two of the substituents R 11 -R 11 together can represent the remainder of a ring, in particular a fused-on phenyl ring,
with the proviso that at least one of the substituents R₁₁-R₁₄ contains an acidic substituent or is an acidic substituent.

II-1

2-Mercapto-8-sulfonaphth[1,2-d] oxazol

II-2

2-Mercapto-7-sulfonaphth[2,3-d] oxazol

II-3

2-Mercapto-5-sulfonaphth[2,1-d] oxazol

II-4

2-Mercapto-6-sulfonaphth[1,2-d] oxazol

II-5

2-Mercapto-8-sulfonaphth[1,8-de] oxazin

II-6

2-Mercapto-5,8-disulfonaphth[1,8-de] oxazin

II-7

2-Mercapto-5,7-disulfonaphth[2,3-d] oxazol

II-8

2-Mercapto-5-chlor-7-sulfobenzoxazol

II-9

2-Mercapto-5-sulfobenzoxazol

II-10

2-Mercapto-5-sulfo-7-chlorbenzoxazol

II-11

2-Mercapto-5-carboxybenzoxazol

II-12

2-Mercapto-7-carboxybenzoxazol

II-13

2-Mercapto-5-aminosulfonylbenzoxazol

II-14

2-Mercapto-7-aminosulfonylbenzoxazol

II-15

2-Mercapto-5-methyl-7-sulfobenzoxazol

II-16

2-Mercapto-5-(sulfophenyl-)oxazol

II-17

2-Mercapto-4-(sulfophenyl)-oxazol

II-18

2-Mercapto-4,5-di-(sulfophenyl)-oxazol

Die Thiazolium-, Selenazolium- und Tellurazoliumverbindungen entsprechen insbesondere der Formel (IV)

worin

X

S, Se, Te

R₁₅

H, Alkyl oder Alkenyl mit bis zu 8 C-Atomen, die auch substituiert sein können - vorzugsweise Methyl oder Ethyl

R₁₆

Alkyl, Alkenyl oder Alkinyl mit bis zu 8 C-Atomen, die auch substituiert sein können durch Hydroxy, Alkoxy, Carboxy, Carbalkoxy, Sulfo oder Halogen

R₁₇, R₁₈, R₁₉, R₂₀

H, Methyl, Ethyl, Halogen, Methoxy, Carboxy, Carbomethoxy, Carbamoyl, Hydroxy, Cyan, Acetamido oder

R₁₇ und R₁₈, R₁₈ und R₁₉ bzw. R₁₉ und R₂₀

paarweise zusammen, die zu einem nicht heterocyclischen 5- oder 6-Ring erforderlichen Ringglieder,

An^⊖

ein Anion und

n

O für den Fall, daß R₁₆ eine Sulfogruppe enthält, und sonst 1 bedeuten.

Examples of compounds of the formula II and III are:

II-1

2-mercapto-8-sulfonaphth [1,2-d] oxazole

II-2

2-mercapto-7-sulfonaphth [2,3-d] oxazole

II-3

2-mercapto-5-sulfonaphth [2,1-d] oxazole

II-4

2-mercapto-6-sulfonaphth [1,2-d] oxazole

II-5

2-mercapto-8-sulfonaphth [1,8-de] oxazine

II-6

2-mercapto-5,8-disulfonaphth [1,8-de] oxazine

II-7

2-mercapto-5,7-disulfonaphth [2,3-d] oxazole

II-8

2-mercapto-5-chloro-7-sulfobenzoxazole

II-9

2-mercapto-5-sulfobenzoxazole

II-10

2-mercapto-5-sulfo-7-chlorobenzoxazole

II-11

2-mercapto-5-carboxybenzoxazole

II-12

2-mercapto-7-carboxybenzoxazole

II-13

2-mercapto-5-aminosulfonylbenzoxazole

II-14

2-mercapto-7-aminosulfonylbenzoxazole

II-15

2-mercapto-5-methyl-7-sulfobenzoxazole

II-16

2-mercapto-5- (sulfophenyl) oxazole

II-17

2-mercapto-4- (sulfophenyl) oxazole

II-18

2-mercapto-4,5-di (sulfophenyl) oxazole

The thiazolium, selenazolium and tellurazolium compounds correspond in particular to the formula (IV)

wherein

X

S, Se, Te

R₁₅

H, alkyl or alkenyl with up to 8 carbon atoms, which can also be substituted - preferably methyl or ethyl

R₁₆

Alkyl, alkenyl or alkynyl with up to 8 carbon atoms, which can also be substituted by hydroxy, alkoxy, carboxy, carbalkoxy, sulfo or halogen

R₁₇, R₁₈, R₁₉, R₂₀

H, methyl, ethyl, halogen, methoxy, carboxy, carbomethoxy, carbamoyl, hydroxy, cyan, acetamido or

R₁₇ and R₁₈, R₁₈ and R₁₉ or R₁₉ and R₂₀

together in pairs, the ring members required to form a non-heterocyclic 5- or 6-ring,

On ^⊖

an anion and

n

O in the event that R₁₆ contains a sulfo group, and otherwise mean 1.

Suitable anions are e.g. B. methosulfate, ethosulfate, tosylate, trifluoromethosulfate, bromide and iodide.

Examples of compounds of the formula IV are:

entsprechen, worin

R₂₁, R₂₂, R₂₃

H, Alkyl oder Alkenyl mit bis zu 8 C-Atomen, die auch substituiert sein können, vorzugsweise Methyl oder Ethyl,

R₂₄, R₂₅, R₂₆, R₂₇, R₂₈

H, Methyl, Ethyl, Halogen, Cyan, Methoxy, Ethoxy

bedeuten.The thiazolium compounds can also have the formula (V)

correspond to what

R₂₁, R₂₂, R₂₃

H, alkyl or alkenyl with up to 8 carbon atoms, which can also be substituted, preferably methyl or ethyl,

R₂₄, R₂₅, R₂₆, R₂₇, R₂₈

H, methyl, ethyl, halogen, cyan, methoxy, ethoxy

mean.

Die erfindungsgemäß zu verwendenden Verbindungen werden vorzugsweise in Mengen von 3·10⁻⁶ bis 10⁻², vorzugsweise insbesondere in Mengen von 10⁻⁵ bis 3·10⁻³ Mol pro Mol Silberhalogenid eingesetzt.Examples of compounds of the formula (V) are:

The compounds to be used according to the invention are preferably used in amounts of 3 × 10⁻⁶ to 10⁻², preferably in particular in amounts of 10⁻⁵ to 3 · 10⁻³ mol per mol of silver halide.

In combination with the stabilizers according to the invention, the emulsions can contain further antifoggants and stabilizers. Azaindenes are particularly suitable, preferably tetra- or penta-azaindenes, in particular those which are substituted by hydroxyl or amino groups. Such connections are described, for example, in the article by Birr, Z. Wiss. Phot. 47 , (1952), pp. 2-58.

Additional stabilizers and antifoggants, such as those listed in Research Disclosure No. 17643 of December 1978, Section VI, published by Industrial Opportunities Ltd., Homewell Havant, Hampshire, P09 1 EF in Great Britain, can be added insofar as they are do not interfere with the action according to the invention of the compounds of classes A, B, C and D.

The light sensitive silver halide recording material can be black and white or preferably color photographic materials.

Examples of color photographic materials are color negative films, color reversal films, color positive films, color photographic paper, color reversal photographic paper, color sensitive materials for the color diffusion transfer process or the silver color bleaching process.

Suitable supports for the production of color photographic materials are e.g. Films and foils of semi-synthetic and synthetic polymers such as cellulose nitrate, cellulose acetate, cellulose butyrate, polystyrene, polyvinyl chloride, polyethylene terephthalate and polycarbonate and paper laminated with a baryta layer or α-olefin polymer layer (e.g. polyethylene). These carriers can be colored with dyes and pigments, for example titanium dioxide. They can also be colored black for the purpose of shielding light. The surface of the support is generally subjected to a treatment in order to improve the adhesion of the photographic emulsion layer, for example a corona discharge with subsequent application of a substrate layer.

The color photographic materials usually contain at least one red-sensitive, green-sensitive and blue-sensitive silver halide emulsion layer and, if appropriate, intermediate layers and protective layers.

Binding agents, silver halide grains and color couplers are essential components of the photographic emulsion layers.

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-vinylpyrrolidone, 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 enough resistant layers can be produced by reaction 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. Oxidized gelatin can also be used. The production such gelatins are described, for example, in The Science and Technology of Gelatine, edited by AG 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 silver halide present as a light-sensitive component in the photographic material can contain chloride, bromide or iodide or mixtures thereof as the halide. For example, the halide content of at least one layer can consist of 0 to 15 mol% of iodide, 0 to 100 mol% of chloride and 0 to 100 mol% of bromide. In the case of color negative and color reversal films, silver bromide iodide emulsions are usually used; in the case of color negative and color reversal paper, silver chloride bromide emulsions with a high chloride content are used up to pure silver chloride emulsions. It can be predominantly compact crystals, which are, for example, regularly cubic or octahedral or can have transitional forms. However, platelet-shaped crystals can preferably 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. However, the layers can also have tabular silver halide crystals, where the ratio of diameter to thickness is much greater than 5: 1, e.g. 12: 1 to 30: 1.

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 e.g. Doping of the individual grain areas are different. The average grain size of the emulsions is preferably between 0.2 μm and 2.0 μm, the grain size distribution can be either homodisperse or heterodisperse. Homodisperse grain size distribution means that 95% of the grains do not deviate from the mean grain size by more than ± 30%. 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. 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 Ostwald ripening, preferably a fine-grained, so-called Lippmann emulsion, mixed with a less soluble emulsion and 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.

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).

Chemical sensitization can be carried out with the addition of compounds of sulfur, selenium, tellurium and / or compounds of gold, platinum, palladium, iridium Furthermore, thiocyanate compounds, surface-active compounds such as thioethers, heterocyclic nitrogen compounds (eg imidazoles, azaindenes) or spectral sensitizers (described, for example, by F. Hamer "The Cyanine Dyes and Related Compounds", 1964, or Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, vol. 18, p. 431 ff. And Research Disclosure No. 17643, section III) are added. As an alternative or in addition, a reduction sensitization can be carried out with the addition of reducing agents (tin-II salts, amines, hydrazine derivatives, aminoboranes, silanes, formamidine sulfinic acid) using hydrogen, by means of low pAg (eg less than 5) and / or high pH (eg above 8) .

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 for example from 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 can also be used as antifoggants such as nitrobenzimidazole, nitroindazole, optionally substituted benzotriazoles or benzthiazolium salts are used. Heterocycles containing mercapto groups, for example mercaptobenzthiazoles, mercaptobenzimidazoles, mercaptotetrazoles, mercaptothiadiazoles, mercaptopyrimidines, which contain a mercapto-carboxyl group, for example, can also contain a water-soluble carboxyl group or a sulfaptoazole 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 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.). In addition to natural surface-active compounds, e.g. saponin, mainly synthetic surface-active compounds (surfactants) are used: non-ionic surfactants, e.g. alkylene oxide compounds, glycerol compounds or glycidol compounds, cationic surfactants, e.g. higher alkylamines, quaternary ammonium salts, pyridine compounds and other heterocyclic compounds, sulfonium compounds or phosphonium compounds, containing anionic surfactants Acid group, for example carboxylic acid, sulfonic acid, a phosphoric acid, sulfuric acid ester or phosphoric acid ester group, ampholytic surfactants, for example amino acid and aminosulfonic acid compounds as well as sulfuric or phosphoric acid esters of an amino alcohol.

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.

Research Disclosure 17643/1978 in Department IV contains an overview of the polymethine dyes suitable as spectral sensitizers, their suitable combinations and combinations with a super-sensitizing effect.

• 1. als Rotsensibilisatoren
  9-Ethylcarbocyanine mit Benzthiazol, Benzselenazol oder Naphthothiazol als basische Endgruppen, die in 5- und/oder 6-Stellung durch Halogen, Methyl, Methoxy, Carbalkoxy, Aryl substituiert sein können sowie 9-Ethyl-naphthoxathia- bzw. -selencarbocyanine und 9-Ethyl-naphthothiaoxa- bzw. -benzimidazocarbocyanine, vorausgesetzt, daß die Farbstoffe mindestens eine Sulfoalkylgruppe am heterocyclischen Stickstoff tragen.
• 2. als Grünsensibilisatoren
  9-Ethylcarbocyanine mit Benzoxazol, Naphthoxazol oder einem Benzoxazol und einem Benzthiazol als basische Endgruppen sowie Benzimidazocarbocyanine, die ebenfalls weiter substituiert sein können und ebenfalls mindestens eine Sulfoalkylgruppe am heterocyclischen Stickstoff enthalten müssen.
• 3. als Blausensibilisatoren
  symmetrische oder asymmetrische Benzimidazo-, Oxa-, Thia- oder Selenacyanine mit mindestens einer Sulfoalkylgruppe am heterocyclischen Stickstoff und gegebenenfalls weiteren Substituenten am aromatischen Kern, sowie Apomerocyanine mit einer Rhodaningruppe.

The following dyes, sorted by spectral range, are particularly suitable:

• 1. as red sensitizers
  9-ethylcarbocyanines with benzthiazole, benzselenazole or naphthothiazole as basic end groups, the can be substituted in the 5- and / or 6-position by halogen, methyl, methoxy, carbalkoxy, aryl and 9-ethyl-naphthoxathia or -selenecarbocyanine and 9-ethyl-naphthothiaoxa- or -benzimidazocarbocyanine, provided that the dyes carry at least one sulfoalkyl group on the heterocyclic nitrogen.
• 2. as green sensitizers
  9-ethyl carbocyanines with benzoxazole, naphthoxazole or a benzoxazole and a benzthiazole as basic end groups, and also benzimidazocarbocyanines, which may also be further substituted and must likewise contain at least one sulfoalkyl group on the heterocyclic nitrogen.
• 3. as blue sensitizers
  symmetrical or asymmetrical benzimidazo, oxa, thia or selenacyanines with at least one sulfoalkyl group on the heterocyclic nitrogen and optionally further substituents on the aromatic nucleus, and apomerocyanines with a rhodanine group.

RS 1:

R₁, R₃, R₇, R₉ = H; R₂, R₈ = Cl;

R₅ = C₂H₅; R₆ = SO₃^⊖; m, n = 3; X, Y = S;

RS 2:

R₁, R₃, R₉ = H; R₂ = Phenyl;

R₅ = C₂H₅; R₆ = SO₃^⊖; R₇, R₈ = -OCH₃; m = 2; n = 3; X = O; Y = S;

RS 3:

R₁, R₉ = H; R₂, R₃ zusammen -CH=CH-CH=CH-; R₄ = SO₃^⊖Na^⊕; R₅ = C₂H₅; R₆ = SO₃^⊖; R₇, R₈ = Cl; m, n = 3; X = S; Y = N-C₂H₅;

RS 4:

R₁ = OCH₃; R₂, R₈ = CH₃; R₃, R₄, R₇, R₉ = H; R₅ = C₂H₅; R₆ = SO₃^⊖; m = 2; n = 4; X = S; Y = Se;

RS 5:

R₁, R₇ = H; R₂, R₃ sowie R₈, R₉ zusammen -CH=CH-CH=CH-;

R₅ = C₂H₅; R₆ = SO₃^⊖; m = 2; n = 3; X, Y = S;

GS 1:

R₁, R₃, R₇, R₉ = H; R₂ = Phenyl;

R₅ = C₂H₅; R₆ = SO₃^⊖; R₈ = Cl; m = 2; n = 3; X, Y = O;

GS 2:

R₁, R₂, R₇, R₈ = Cl; R₃, R₅, R₆, R₉ = H;

m, n = 2; X, Y = N-C₂H₅;

GS 3:

R₁, R₇ = H; R₂, R₃ sowie R₈, R₉ zusammen -CH=CH-CH=CH-; R₄ = SO₃^⊖Na^⊕; R₅ = C₂H₅; R₆ = SO₃^⊖; m, n = 3; X, Y = O;

GS 4:

R₁, R₃, R₄, R₇, R₈, R₉ = H; R₂ = OCH₃; R₅ = C₂H₅; R₆ = SO₃^⊖; m = 2; n = 4; X = O; Y = S;

BS 1:

BS 2:

BS 3:

R₁₁ = -CH₂-COOH

BS 4:

R₁₁ = C₂H₅

BS 5:

R₁₁ = C₂H₅

Auf Sensibilisatoren kann verzichtet werden, wenn für einen bestimmten Spektralbereich die Eigenempfindlichkeit des Silberhalogenids ausreichend ist, beispielsweise die Blauempfindlichkeit von Silberbromiden.Examples, in particular for negative and reversal film, are the red sensitizers RS, green sensitizers GS and blue sensitizers BS, which can be used individually or in combination with each other, e.g. RS 1 and RS 2, and GS 1 and GS 2.

RS 1:

R₁, R₃, R₇, R₉ = H; R₂, R₈ = Cl;

R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; m, n = 3; X, Y = S;

RS 2:

R₁, R₃, R₉ = H; R₂ = phenyl;

R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; R₇, R₈ = -OCH₃; m = 2; n = 3; X = O; Y = S;

RS 3:

R₁, R₉ = H; R₂, R₃ together -CH = CH-CH = CH-; R₄ = SO₃ ^⊖ Na ^⊕ ; R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; R₇, R₈ = Cl; m, n = 3; X = S; Y = N-C₂H₅;

RS 4:

R₁ = OCH₃; R₂, R₈ = CH₃; R₃, R₄, R₇, R₉ = H; R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; m = 2; n = 4; X = S; Y = Se;

RS 5:

R₁, R₇ = H; R₂, R₃ and R₈, R₉ together -CH = CH-CH = CH-;

R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; m = 2; n = 3; X, Y = S;

GS 1:

R₁, R₃, R₇, R₉ = H; R₂ = phenyl;

R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; R₈ = Cl; m = 2; n = 3; X, Y = O;

GS 2:

R₁, R₂, R₇, R₈ = Cl; R₃, R₅, R₆, R₉ = H;

m, n = 2; X, Y = N-C₂H₅;

GS 3:

R₁, R₇ = H; R₂, R₃ and R₈, R₉ together -CH = CH-CH = CH-; R₄ = SO₃ ^⊖ Na ^⊕ ; R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; m, n = 3; X, Y = O;

GS 4:

R₁, R₃, R₄, R₇, R₈, R₉ = H; R₂ = OCH₃; R₅ = C₂H₅; R₆ = SO₃ ^⊖ ; m = 2; n = 4; X = O; Y = S;

BS 1:

BS 2:

BS 3:

R₁₁ = -CH₂-COOH

BS 4:

R₁₁ = C₂H₅

BS 5:

R₁₁ = C₂H₅

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 bromides.

The differently sensitized emulsion layers are assigned non-diffusing monomeric or polymeric color couplers, which can be located in the same layer or in a layer adjacent to it. Usually, the red-sensitive layers become cyan couplers, assigned to the green-sensitive layers of purple couplers and the blue-sensitive layers of yellow couplers.

BG 1:

R₁ = H; R₂ = H;

BG 2:

R₁ = -NHCOOCH₂-CH(CH₃)₂; R₂ = H; R₃ = -(CH₂)₃-OC₁₂H₂₅

BG 3:

R₁ = H; R₂ = -OCH₂-CH₂-SO₂CH₃; R₃ = C₁₆H₃₃

BG 4:

R₁ = H; R₂ = -OCH₂-CONH-(CH₂)₂-OCH₃;

BG 5:

R₁ = H; R₂ = H;

BG 6:

R₁ = H; R₂ = H;

BG 7:

R₁ = H; R₂ = Cl; R₃ = -C (C₂H₅)₂-(CH₂)₂₀-CH₃

BG 8:

R₁ = H; R₂ = -O-CH₂-CH₂-S-CH(COOH)-C₁₂H₂₅ R₃ = Cyclohexyl

BG 9:

R₁ = -C₄H₉; R₂ = H; R₃ = -CN; R₄ = Cl

BG 10:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = -SO₂CHF₂

BG 11:

R₁ = -C₄H₉;

R₃ = H; R₄ = -CN

BG 12:

R₁ = C₂H₅; R₂ = H; R₃ = H; R₄ = -SO₂CH₃

BG 13:

R₁ = -C₄H₉; R₂ H; R₃ = H; R₄ = -SO₂-C₄H₉

BG 14:

R₁ = -C₄H₉; R₂ = H; R₃ = -CN; R₄ = -CN

BG 15:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = -SO₂-CH₂-CHF₂

BG 16:

R₁ = -C₂H₅; R₂ = H; R₃ = H; R₄ = -SO₂CH₂-CHF-C₃H₇

BG 17:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = F

BG 18:

R₁ = -C₄H₉; R₂ =H; R₃ =H; R₄ = -SO₂CH₃

BG 19:

R₁ = -C₄H₉; R₂ =H; R₃ =H; R₄ = -CN

BG 20:

R₁ = -CH₃; R₂ = -C₂H₅; R₃, R₄ = -t-C₅H₁₁

BG 21:

R₁ = -CH₃; R₂ = H; R₃, R₄ = -t-C₅H₁₁

BG 22:

R₁ = -C₂H₅; R₂ = -C₂H₅; R₃, R₄ = -t-C₅H₁₁

BG 23:

R₁ -C₂H₅; R₂ = -C₄H₉; R₃, R₄ = -t-C₅H₁₁

BG 24:

R₁ = -C₂H₅; R₂ = -C₄H₉; R₃, R₄ = -t-C₄H₉

BG 25:

R₁, R₂ = -t-C₅H₁₁; R₃ = -C₄H₉; R₄ = H; R₅ = -C₃F₇

BG 26:

R₁ = -NHSO₂-C₄H₉; R₂ = H; R₃ = -C₁₂H₂₅; R₄ = Cl; R₅ = Phenyl

BG 27:

R₁, R₂ = -t-C₅H₁₁; R₂ = Cl, R₃ = -CH(CH₃)₂; R₄ = Cl; R₅ = Pentafluorphenyl

BG 28:

R₁ = -t-C₅H₁₁; R₂ = Cl; R₃ = -C₆H₁₃; R₄ = Cl; R₅ = -2-Chlorphenyl

Farbkuppler zur Erzeugung des purpurnen Teilfarbenbildes sind in der Regel Kuppler vom Typ des 5-Pyrazolons, des Indazolons oder der Pyrazoloazole; geeignete Beispiele hierfür sind

PP 1:

R₂ = H

PP 2:

R₂ = H

PP 3:

R₁ = -C₁₃H₂₇; R₂ = H

PP 4:

R₁ = -O-C₁₆H₃₃; R₂ = H

PP 5:

R₁ = -C₁₃N₂₇;

PP 6:

PP 7:

PP 8:

PP 9:

PP 10:

PP 11:

R₂ = H

PP 12:

R₂ = H

PP 13:

R₂ = H

PP 14:

PP 15:

PP 16:

PP 17:

PP 18:

R₂ = -CH₃

PP 19:

R₂ = -CH₃

PP 20:

R₂ = -t-C₄H₉

PP 21:

R₂ = -CH₃

PP 22:

Farbkuppler zur Erzeugung das gelben Teilfarbenbildes sind in der Regel Kuppler mit einer offenkettigen Ketomethylengruppierung, insbesondere Kuppler vom Typ des α-Acylacetamids; geeignete Beispiele hierfür sind α-Benzoylacetanilidkuppler und α-Pivaloylacetanilidkuppler der Formeln

GB 1:

R₂ = Cl;

GB 2:

R₂ = -OC₁₆H₃₃; R₃ = -SO₂NHCH₃

GB 3:

R₂ = Cl R₃ = -NHSO₂-C₁₆H₃₃

GB 4:

R₂ = Cl; R₃ = -COOC₁₂H₂₅

GB 5:

R₂ = Cl

GB 6:

R₂ = Cl;

GB 7:

R₂ = Cl; R₃ = -NHSO₂C₁₆H₃₃

GB 8:

R₂ = Cl;

GB 9:

R₂ = OC₁₆H₃₃; R₃ = -SO₂NHCOC₂H₅

GB 10:

R₂ = Cl;

GB 11:

R₂ = Cl;

GB 12:

R₂ = Cl;

GB 13:

R₂ = -OC₁₆H₃₃; R₃ = -SO₂NHCH₃

GB 14:

R₂ = Cl

GB 15:

R₁, R₃, R₅, R₆ = H; R₄ = -OCH₃;

GB 16:

R₂, R₆ = H; R₁ = -OC₁₆H₃₃; R₄, R₅ = -OCH₃;

GB 17:

R₂, R₆ = H; R₁ = -OCH₃, R₄ = Cl; R₅ = -COOC₁₂H₂₅;

GB 18;

R₂ = H; R₁ = -OC₁₆H₃₃; R₄ = Cl; R₅, R₆ = -OCH₃;

GB 19:

R₂, R₅ = H; R₁ = -OC₁₆H₃₃; R₄ = -OCH₃;

R₆ = -SO₂N(CH₃)₂

GB 20:

R₂, R₆ = H; R₁, R₄ = -OCH₃;

GB 21:

Bei den Farbkupplern kann es sich um 4-Äquivalentkuppler, aber auch um 2-Äquivalentkuppler handeln. Letztere leiten sich von den 4-Äquivalentkupplern dadurch ab, daß sie in der Kupplungsstelle einen Substituenten enthalten, der bei der Kupplung abgespalten wird. Zu den 2-Äquivalentkupplern sind solche zu rechnen, die farblos sind, als auch solche, die eine intensive Eigenfarbe aufweisen, die bei der Farbkupplung verschwindet bzw. durch die Farbe des erzeugten Bildfarbstoffes ersetzt wird (Maskenkuppler), und die Weißkuppler, die bei Reaktion mit Farbentwickleroxidationsprodukten im wesentlichen farblose Produkte ergeben. Zu den 2-Äquivalentkupplern sind ferner solche Kuppler zu rechnen, die in der Kupplungsstelle einen abspaltbaren Rest enthalten, der bei Reaktion mit Farbentwickleroxidationsprodukten in Freiheit gesetzt wird und dabei entweder direkt oder nachdem aus dem primär abgespaltenen Rest eine oder mehrere weitere Gruppen abgespalten worden sind (z.B. DE-A-27 03-145, DE-A-28 55 697, DE-A-31 05 026, DE-A-33 19 428), eine bestimmte erwünschte fotografische Wirksamkeit entfaltet, z.B. als Entwicklungsinhibitor oder -accelerator. Beispiele für solche 2-Äquivalentkuppler sind die bekannten DIR-Kuppler wie auch DAR-bzw. FAR-Kuppler.Color couplers for producing the blue-green partial color image are usually couplers of the phenol or α-naphthol type; suitable examples are

BG 1:

R₁ = H; R₂ = H;

BG 2:

R₁ = -NHCOOCH₂-CH (CH₃) ₂; R₂ = H; R₃ = - (CH₂) ₃-OC₁₂H₂₅

BG 3:

R₁ = H; R₂ = -OCH₂-CH₂-SO₂CH₃; R₃ = C₁₆H₃₃

BG 4:

R₁ = H; R₂ = -OCH₂-CONH- (CH₂) ₂-OCH₃;

BG 5:

R₁ = H; R₂ = H;

BG 6:

R₁ = H; R₂ = H;

BG 7:

R₁ = H; R₂ = Cl; R₃ = -C (C₂H₅) ₂- (CH₂) ₂₀-CH₃

BG 8:

R₁ = H; R₂ = -O-CH₂-CH₂-S-CH (COOH) -C₁₂H₂₅ R₃ = cyclohexyl

BG 9:

R₁ = -C₄H₉; R₂ = H; R₃ = -CN; R₄ = Cl

BG 10:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = -SO₂CHF₂

BG 11:

R₁ = -C₄H₉;

R₃ = H; R₄ = -CN

BG 12:

R₁ = C₂H₅; R₂ = H; R₃ = H; R₄ = -SO₂CH₃

BG 13:

R₁ = -C₄H₉; R₂ H; R₃ = H; R₄ = -SO₂-C₄H₉

BG 14:

R₁ = -C₄H₉; R₂ = H; R₃ = -CN; R₄ = -CN

BG 15:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = -SO₂-CH₂-CHF₂

BG 16:

R₁ = -C₂H₅; R₂ = H; R₃ = H; R₄ = -SO₂CH₂-CHF-C₃H₇

BG 17:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = F

BG 18:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = -SO₂CH₃

BG 19:

R₁ = -C₄H₉; R₂ = H; R₃ = H; R₄ = -CN

BG 20:

R₁ = -CH₃; R₂ = -C₂H₅; R₃, R₄ = -t-C₅H₁₁

BG 21:

R₁ = -CH₃; R₂ = H; R₃, R₄ = -t-C₅H₁₁

BG 22:

R₁ = -C₂H₅; R₂ = -C₂H₅; R₃, R₄ = -t-C₅H₁₁

BG 23:

R₁ -C₂H₅; R₂ = -C₄H₉; R₃, R₄ = -t-C₅H₁₁

BG 24:

R₁ = -C₂H₅; R₂ = -C₄H₉; R₃, R₄ = -t-C₄H₉

BG 25:

R₁, R₂ = -t-C₅H₁₁; R₃ = -C₄H₉; R₄ = H; R₅ = -C₃F₇

BG 26:

R₁ = -NHSO₂-C₄H₉; R₂ = H; R₃ = -C₁₂H₂₅; R₄ = Cl; R₅ = phenyl

BG 27:

R₁, R₂ = -t-C₅H₁₁; R₂ = Cl, R₃ = -CH (CH₃) ₂; R₄ = Cl; R₅ = pentafluorophenyl

BG 28:

R₁ = -t-C₅H₁₁; R₂ = Cl; R₃ = -C₆H₁₃; R₄ = Cl; R₅ = -2-chlorophenyl

Color couplers for generating the purple partial color image are generally couplers of the 5-pyrazolone, indazolone or pyrazoloazole type; suitable examples are

PP 1:

R₂ = H

PP 2:

R₂ = H

PP 3:

R₁ = -C₁₃H₂₇; R₂ = H

PP 4:

R₁ = -O-C₁₆H₃₃; R₂ = H

PP 5:

R₁ = -C₁₃N₂₇;

PP 6:

PP 7:

PP 8:

PP 9:

PP 10:

PP 11:

R₂ = H

PP 12:

R₂ = H

PP 13:

R₂ = H

PP 14:

PP 15:

PP 16:

PP 17:

PP 18:

R₂ = -CH₃

PP 19:

R₂ = -CH₃

PP 20:

R₂ = -t-C₄H₉

PP 21:

R₂ = -CH₃

PP 22:

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; suitable examples of this are α-benzoylacetanilide couplers and α-pivaloylacetanilide couplers of the formulas

GB 1:

R₂ = Cl;

GB 2:

R₂ = -OC₁₆H₃₃; R₃ = -SO₂NHCH₃

GB 3:

R₂ = Cl R₃ = -NHSO₂-C₁₆H₃₃

GB 4:

R₂ = Cl; R₃ = -COOC₁₂H₂₅

GB 5:

R₂ = Cl

GB 6:

R₂ = Cl;

GB 7:

R₂ = Cl; R₃ = -NHSO₂C₁₆H₃₃

GB 8:

R₂ = Cl;

GB 9:

R₂ = OC₁₆H₃₃; R₃ = -SO₂NHCOC₂H₅

GB 10:

R₂ = Cl;

GB 11:

R₂ = Cl;

GB 12:

R₂ = Cl;

GB 13:

R₂ = -OC₁₆H₃₃; R₃ = -SO₂NHCH₃

GB 14:

R₂ = Cl

GB 15:

R₁, R₃, R₅, R₆ = H; R₄ = -OCH₃;

GB 16:

R₂, R₆ = H; R₁ = -OC₁₆H₃₃; R₄, R₅ = -OCH₃;

GB 17:

R₂, R₆ = H; R₁ = -OCH₃, R₄ = Cl; R₅ = -COOC₁₂H₂₅;

GB 18;

R₂ = H; R₁ = -OC₁₆H₃₃; R₄ = Cl; R₅, R₆ = -OCH₃;

GB 19:

R₂, R₅ = H; R₁ = -OC₁₆H₃₃; R₄ = -OCH₃;

R₆ = -SO₂N (CH₃) ₂

GB 20:

R₂, R₆ = H; R₁, R₄ = -OCH₃;

GB 21:

The color couplers can be 4-equivalent couplers, but also 2-equivalent couplers. The latter are derived from the 4-equivalent couplers in that they contain a substituent in the coupling point, 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 when the color is coupled or is replaced by the color of the image dye produced (mask coupler), and the white couplers that react with color developer oxidation products yield essentially colorless products. The 2-equivalent couplers also include those couplers that contain a cleavable residue in the coupling point, which is released upon reaction with color developer oxidation products and thereby either directly or after one or more further groups have been cleaved from the primarily cleaved residue ( eg DE-A-27 03-145, DE-A-28 55 697, DE-A-31 05 026, DE-A-33 19 428), a certain desired photographic activity unfolds, for example as a development inhibitor or accelerator. Examples of such 2-equivalent couplers are the known DIR couplers as well as DAR or. FAR coupler.

Beispiele für Maskenkuppler sind

DIR-Kuppler, die Entwicklungsinhibitoren vom Azoltyp, z.B. Triazole und Benzotriazole freisetzen, sind in DE-A-24 14 006, 26 10 546, 26 59 417, 27 54 281, 27 26 180, 36 26 219, 36 30 564, 36 36 824, 36 44 416 und 28 42 063 beschrieben. Weitere Vorteile für die Farbwiedergabe, d.h., Farbtrennung und Farbreinheit, und für die Detailwiedergabe, d.h., Schärfe und Körnigkeit, sind mit solchen DIR-Kupplern zu erzielen, die z.B. den Entwicklungsinhibitor nicht unmittelbar als Folge der Kupplung mit einem oxidierten Farbentwickler abspalten, sondern erst nach einer weiteren Folgereaktion, die beispielsweise mit einer Zeitsteuergruppe erreicht wird. Beispiele dafür sind in DE-A-28 55 697, 32 99 671, 38 18 231, 35 18 797, in EP-A-157 146 und 204 175, in US-A-4 146 396 und 4 438 393 sowie in GB-A-2 072 363 beschrieben.Examples of white couplers are:

Examples of mask couplers are

DIR couplers which release development inhibitors of the azole type, for example triazoles and benzotriazoles, are described in DE-A-24 14 006, 26 10 546, 26 59 417, 27 54 281, 27 26 180, 36 26 219, 36 30 564, 36 36 824, 36 44 416 and 28 42 063. Further advantages for color reproduction, ie, color separation and color purity, and for detail reproduction, ie, sharpness and granularity, can be achieved with those DIR couplers which, for example, do not split off the development inhibitor directly as a result of the coupling with an oxidized color developer, but only after a further follow-up reaction, which is achieved, for example, with a timing group. Examples of these are in DE-A-28 55 697, 32 99 671, 38 18 231, 35 18 797, in EP-A-157 146 and 204 175, in US-A-4 146 396 and 4 438 393 and in GB -A-2 072 363.

DIR couplers which release a development inhibitor which is decomposed into essentially photographically ineffective products in the developer bath are described, for example, in DE-A-32 09 486 and in EP-A-167 168 and 219 713. This measure ensures trouble-free development and processing consistency.

When using DIR couplers, in particular those which release an easily diffusible development inhibitor, suitable measures can be taken to improve the color rendering, e.g. achieve a more differentiated color rendering, as described, for example, in EP-A-115 304, 167 173, GB-A-2 165 058, DE-A-37 00 419 and US-A-4 707 436.

The DIR couplers can be added to a wide variety of layers in a multilayer photographic material, for example also light-insensitive or intermediate layers. However, they are preferably added to the light-sensitive silver halide emulsion layers, the characteristic properties of the silver halide emulsion, for example its iodide content, the structure of the silver halide grains or their grain size distribution having an influence on the photographic properties achieved. The influence of the inhibitors released can be limited, for example, by incorporating an inhibitor scavenger layer in accordance with DE-A-24 31 223. For reasons of reactivity or stability, it may be advantageous to use a DIR coupler which forms in the respective layer in which it is introduced a color which is different from the color to be produced in this layer in the coupling.

To increase the sensitivity, the contrast and the maximum density, DAR or FAR couplers can be used, which release a development accelerator or an fogger. Compounds of this type are, for example, in DE-A-25 34 466, 32 09 110, 33 33 355, 34 10 616, 34 29 545, 34 41 823, in EP-A-89 834, 110 511, 118 087, 147 765 and described in US-A-4,618,572 and 4,656,123.

As an example for the use of BAR couplers (Bleach Accelerator Releasing Coupler), reference is made to EP-A-193 389.

It can be advantageous to modify the effect of a photographically active group which is split off from a coupler in that an intermolecular reaction of this group occurs after its release with another group according to DE-A-35 06 805.

Beispiele für DAR-Kuppler

Da bei den DIR-, DAR- bzw. FAR-Kupplern hauptsächlich die Wirksamkeit des bei der Kupplung freigesetzten Restes erwünscht ist und es weniger auf die farbbildenden Eigenschaften dieser Kuppler ankommt, sind auch solche DIR-, DAR- bzw FAR-Kuppler geeignet, die bei der Kupplung im wesentlichen farblose Produkte ergeben (DE-A-15 47 640).Examples of DIR couplers are:

Examples of DAR couplers

Since the DIR, DAR or FAR couplers mainly want the effectiveness of the residue released during the coupling and the color-forming properties of these couplers are less important, DIR, DAR or FAR couplers are also suitable which: in the coupling result in essentially colorless products (DE-A-15 47 640).

The cleavable residue can also be a ballast residue, so that upon reaction with color developer oxidation products coupling products are obtained which are diffusible or at least have a weak or restricted mobility (US Pat. No. 4,420,556).

The material may further contain compounds other than couplers, which can, for example, release a development inhibitor, a development accelerator, a bleaching accelerator, a developer, a silver halide solvent, a fogging agent or an antifoggant, for example so-called DIR-hydroquinones and other compounds, as described for example in US-A-4 636 546, 4 345 024, 4 684 604 and in DE-A-31 45 640, 25 15 213, 24 47 079 and in EP-A-198 438. These compounds perform the same function as the DIR, DAR or FAR couplers, except that they do not form coupling products.

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 by first preparing a solution, a dispersion or an emulsion of the compound in question and then adding it to the casting solution for the layer in question. Choosing the right one Solvents or dispersants depend 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-26 09 741 and DE-A-26 09 742.

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-O 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-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 diffusion-resistant incorporation of anionic water-soluble compounds (eg dyes) can also be carried out with the aid of cationic polymers, so-called pickling polymers.

Suitable oil formers are e.g. Alkyl phthalates, phosphonic acid esters, phosphoric acid esters, citric acid esters, benzoic acid esters, amides, fatty acid esters, trimesic acid esters, alcohols, phenols, aniline derivatives and hydrocarbons.

Examples of suitable oil formers are dibutylphthalate, dicyclohexylphthalate, di-2-ethylhexylphthalate, decylphthalate, triphenylphosphate, tricresylphosphate, 2-ethylhexyldiphenylphosphate, tricyclohexylphosphate, tri-2-ethylhexylphosphate, tridecoxyphosphate, 2-ethylhexylphosphate, tridecoxyphosphate, 2-ethylhexylphosphate, , 2-ethylhexyl p-hydroxybenzoate, diethyldodecanamide, N-tetradecylpyrrolidone, isostearyl alcohol, 2,4-di-tert.-amylphenol, dioctylacelate, glycerol tributyrate, isostearyl lactate, trioctyl citrate, N, N-doxy-5-butyl-2-butyl -octylaniline, paraffin, dodecylbenzene and diisopropylnaphthalene.

Each of the differently sensitized, 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 selected 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.

Suitable agents, which are also called scavengers or EOP-catchers, are described in Research Disclosure 17 643 (Dec. 1978), Chapter VII, 17 842/1979, pages 94-97 and 18.716 / 1979, page 650 and in EP-A- 69,070, 98,072, 124,877, 125,522 and in US-A-463,226.

R₁, R₂ =

-t-C₈H₁₇
-s-C₁₂H₂₅
-t-C₆H₁₃

-s-C₈H₁₇
-C₁₅H₃₁

Liegen mehrere Teilschichten gleicher spektraler Sensibilisierung vor, so können sich diese hinsichtlich ihrer Zusammensetzung, insbesondere was Art und Menge der Silberhalogenidkörnchen betrifft unterscheiden. Im allgemeinen wird die Teilschicht mit höherer Empfindlichkeit von Träger entfernter angeordnet sein als die Teilschicht mit geringerer Empfindlichkeit. Teilschichten gleicher spektraler Sensibilisierung können zueinander benachbart oder durch andere Schichten, z.B. durch Schichten anderer spektraler Sensibilisierung getrennt sein. So können z.B. alle hochempfindlichen und alle niedrigempfindlichen Schichten jeweils zu einem Schichtpaket zusammengefaßt sein (DE-A-19 58 709, DE-A-25 30 645, DE-A-26 22 922).Examples of particularly suitable compounds are:

R₁, R₂ =

-t-C₈H₁₇
-s-C₁₂H₂₅
-t-C₆H₁₃

-s-C₈H₁₇
-C₁₅H₃₁

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 through other layers, for example through Layers of other spectral sensitization must be separated. For example, all highly sensitive and all low-sensitive layers can be combined to form a layer package (DE-A-19 58 709, DE-A-25 30 645, DE-A-26 22 922).

The photographic material can also contain UV light-absorbing compounds, whiteners, spacers, filter dyes, formalin scavengers, light stabilizers, antioxidants, D _min dyes, additives to improve dye, coupler and white stabilization and to reduce the color fog, plasticizers (latices), Contain biocides 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).

Es können auch ultraviolettabsorbierende Kuppler (wie Blaugrünkuppler des α-Naphtholtyps) und ultraviolettabsorbierende Polymere verwendet werden. Diese Ultraviolettabsorbentien können durch Beizen in einer speziellen Schicht fixiert sein.Examples of particularly suitable compounds are

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, styryl 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 17,643 (Dec. 1978), Chapter V, in US-A-2,632,701, 3,269,840 and in GB-A-852,075 and 1,319,763.

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-33 31 542, DE-A-34 24 893, Research Disclosure 17 643, (Dec. 1978), Chapter XVI).

The average particle diameter of the spacers is in particular in the range from 0.2 to 10 μm. 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.

Zusätze zur Verbesserung der Farbstoff-, Kuppler- und Weißenstabilität sowie zur Verringerung des Farbschleiers (Research Disclosure 17 643/1978, Kapitel VII) können den folgenden chemischen Stoffklasen angehören: Hydrochinone, 6-Hydroxychromane, 5-Hydroxycumarane, Spirochromane, Spiroindane, p-Alkoxyphenole, sterische gehinderte Phenole, Gallussäurederivate, Methylendioxybenzole, Aminophenole, sterisch gehinderte Amine, Derivate mit veresterten oder verätherten phenolischen Hydroxylgruppen, Metallkomplexe.Suitable formalin scavengers include

Additives to improve dye, coupler and whiteness stability and to reduce the color fog (Research Disclosure 17 643/1978, Chapter VII) can belong to the following chemical substance classes: hydroquinones, 6-hydroxychromanes, 5-hydroxycoumarans, spirochromanes, spiroindanes, p- Alkoxyphenols, sterically hindered phenols, gallic acid derivatives, methylenedioxybenzenes, aminophenols, sterically hindered amines, derivatives with esterified or etherified phenolic hydroxyl groups, metal complexes.

Compounds that have both a hindered amine partial structure and a hindered phenol partial structure in one molecule (US-A-4,268,593) are particularly effective in preventing the degradation (degradation) of yellow color images as a result the development of heat, moisture and light. In order to prevent the deterioration (deterioration or degradation) of crimson color images, in particular their impairment (deterioration or degradation) as a result of exposure to light, Spiroindane (JP-A-159 644/81) and chromanes are caused by Hydroquinone diethers or monoethers are particularly effective (JP-A-89 835/80).

sowie die als EOP-Fänger aufgeführten Verbindungen.Examples of particularly suitable compounds are:

as well as the compounds listed as EOP catchers.

The layers of the photographic material can be hardened with the usual hardening agents. Suitable curing agents include formaldehyde, glutaraldehyde and similar aldehyde compounds, diacetyl, cyclopentadione and similar ketone compounds, bis (2-chloroethylurea), 2-hydroxy-4,6-dichloro-1,3,5-triazine and other compounds, the reactive halogen contain (US-A-3 288 775, US-A-2 732 303, GB-A-974 723 and GB-A-1 167 207) divinyl sulfone compounds, 5-acetyl-1,3-diacryloylhexahydro-1,3,5 triazine and other compounds containing a reactive olefin bond (US-A-3 635 718, US-A-3 232 763 and GB-A-994 869); N-hydroxymethylphthalimide and other N-methylol compounds (US-A-2 732 316 and US-A-2 586 168); Isocyanates (US-A-3 103 437); Aziridine compounds (US-A-3 017 280 and US-A-2 983 611); Acid derivatives (U.S. 2,725,294 and U.S. 2,725,295); Carbodiimide type compounds (US-A-3 100 704); Carbamoylpyridinium salts (DE-A-22 25 230 and DE-A-24 39 551); Carbamoyloxypyridinium compounds (DE-A-24 08 814); Compounds with a phosphorus-halogen bond (JP-A-113 929/83); N-carbonyloximide compounds (JP-A-43353/81); N-sulfonyloximido compounds (US-A-4 111 926), dihydroquinoline compounds (US-A-4 013 468), 2-sulfonyloxypyridinium salts (JP-A-110 762/81), formamidinium salts (EP-A-0 162 308) , Compounds having two or more N-acyloximino groups (US-A-4 052 373), epoxy compounds (US-A-3 091 537), isoxazole-type compounds (US-A-3 321 313 and US-A-3 543 292); Halocarboxyaldehydes such as mucochloric acid; Dioxane derivatives such as dihydroxydioxane and di-chlorodioxane; and inorganic hardeners such as chrome alum and zirconium sulfate.

The hardening can be effected in a known manner by adding the hardening agent to the casting solution for the layer to be hardened, or by overlaying the layer to be hardened with a layer which contains a diffusible hardening agent.

There are slow-acting and fast-acting hardeners and so-called instant hardeners, which are particularly advantageous, in the classes listed. Soft hardeners are understood to mean compounds that crosslink suitable binders in such a way that the hardening is completed immediately after casting, at the latest after 24 hours, preferably after 8 hours at the latest, so that no further change in the sensitometry caused by the crosslinking reaction and swelling of the layer structure occurs . 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 which react very quickly with gelatin are, for example, 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 with the formation of peptide bonds and crosslinking of 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

  

  der 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

  

  which is 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 represent the atoms required to complete an optionally substituted heterocyclic ring, for example a piperidine, piperazine or morpholine ring, which ring may be substituted, for example, by C₁-C₃alkyl 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).

There are diffusible curing agents that have the same curing effect on all layers within a layer structure. But there are also layer-limited, non-diffusing, low molecular weight and high molecular hardener. They can be used to link individual layers, for example the protective layer, particularly strongly. This is important if the silver halide layer is hardened little because of the increase in silver opacity and the protective layer has to improve the mechanical properties (EP-A 0 114 699).

Color photographic negative materials are usually processed by developing, bleaching, fixing and washing or by developing, bleaching, fixing and stabilizing without subsequent washing, whereby bleaching and fixing can be combined into one processing step. All developer compounds which have the ability to react in the form of their oxidation product with color couplers to form azomethine or indophenol 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-methanesulfonamidoethyl) -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 , 3106 (1951) and G. Haist, Modern Photographic Processing, 1979, John Wiley and Sons, New York, page 545 ff.

After the color development, an acidic stop bath or its watering can follow.

Usually the material is bleached and fixed immediately after color development. As bleaching agents e.g. Fe (III) salts and Fe (III) complex salts such as ferricyanides, dichromates, water-soluble cobalt complexes can be used. Iron (III) complexes of aminopolycarboxylic acids are particularly preferred, especially e.g. of ethylenediaminetetraacetic acid, propylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, iminodiacetic acid, N-hydroxyethylethylenediaminetriacetic acid, alkyliminodicarboxylic acids and corresponding phosphonic acids. Persulfates and peroxides, e.g. Hydrogen peroxide.

The bleach-fixing bath or fixing bath is usually followed by washing, which is designed as countercurrent washing or consists of several tanks with their own water supply.

Favorable results can be obtained using a subsequent final bath which contains little or no formaldehyde.

However, the washing can be completely replaced by a stabilizing bath, which is usually carried out in countercurrent. When formaldehyde is added, this stabilizing bath also acts as a final bath.

In the case of color reversal materials, development is first carried out using a black and white developer whose oxidation product is not capable of reacting with the color couplers. This is followed by a diffuse second exposure and then development with a color developer, bleaching and fixing.

example 1

Anschließend wurden 2,0 mmol 6-Methyl-4-hydroxy-1,3,3a,7-tetraazainden/mol Ag zugesetzt, um die Emulsion zu stabilisieren. Die Emulsion wurde aufgeteilt.A cubic silver chloride bromide iodide emulsion with 3 mol% chloride and 4.5 mol% iodide, in which the diameters of the spheres equal in volume to the emulsion grains were 90%> 0.40 µm and 90% <0.87 µm and the most common Diameter was 0.58 µm, was ripened with 8.4 µmol sodium thiosulfate / mol Ag, 6.3 µmol sodium dithiosulfato-aurate (I) / mol Ag and 441 µmol ammonium thiocyanate / mol Ag at 58 ° C for two hours and with 0.188 µmol / Mol Ag of dye VI and 0.325 µmol / mol Ag of dye VII spectrally sensitized.

Then 2.0 mmol of 6-methyl-4-hydroxy-1,3,3a, 7-tetraazainden / mol Ag were added in order to stabilize the emulsion. The emulsion was divided.

Various portions of this emulsion were mixed with latent image stabilizers in accordance with Table 1, Experiments Nos. 1 to 8. These portions were each brought to a gelatin content of 221 g gelatin / mol Ag by addition of gelatin, adjusted to pH 6.7 and pAg 9.0, applied to a transparent layer support (silver application 32 mmolAg / m²) and hardened by means of a protective layer.

The exposure of the film samples was carried out in a sensitometer behind a ³√2 step gray wedge, the development at 20 ° C in a commercially available black and white developer (refinal) for 16 minutes. In order to determine the storage behavior, a sample was processed fresh (= not stored, within 6 hours after exposure); a second sample was exposed, then stored for 14 days at 57 ° C. and 35% relative humidity and then processed; in each case a third sample was stored before exposure to 14 tablets at 57 ° C. and 35% relative humidity, then exposed and processed within 6 hours after the exposure.

From Table 1 it can be seen that the heterocyclic mercapto compounds I-3 and II-8 combined and combined with one another more or less reduce the decline in the latent image, but markedly reduce the sensitivity of the fresh material. If the benzselenazolium compound IV-16 is added to I-3 or II-8, the sensitivity of the fresh material increases again, while at the same time the decline in the latent image is further reduced; the rise of the veil remains low with these combinations. In the combination of three (experiment 8) the latent image is the most stable and at the same time the sensitivity of the fresh material is least reduced. When used alone, the benzselenazolium compound IV-16 leads to a significant increase in fog when stored.

Example 2

The experiments listed in Table 2 are carried out with the emulsion given in Example 1. The heterocyclic mercapto compound I-4 reduces the sensitivity of the fresh material little and stabilizes the latent image less than the compound I-3, the combination of I-4 with IV-16 and the combination of I-4 with IV-16 and II- 8 lead to a drastic improvement in latent image stability, with the combination of three (experiment 12) again having the highest sensitivity.

Example 3

With the heterocyclic mercapto compounds I-38 and II-8, the benzselenazolium compound IV-17 and the emulsion given in Example 1, the results summarized in Table 3 are obtained. Analogously to the previous examples, the best latent image stabilization is achieved using the combination of three (experiment 18).

Example 4

The benzthiazolium compound IV-9 and the thiazolium compound V-1 in combination with the compound II-8 and one of the compounds I-3, I-4 or I-38 show similar effects to the benzselenazolium compounds IV-16 and IV-17 (emulsion as in Example 1).

Claims (6)

1. A photosensitive silver halide recording material comprising a support and at least one photosensitive silver halide emulsion layer containing both at least one heterocyclic mercapto compound and at least one colourless thiazolium, selenazolium or tellurazolium compound, characterized in that the heterocyclic mercapto compound corresponds to formula (I):

   

   in which

   R₁   is hydrogen; an alkyl group containing up to 9 C atoms which may be substituted; an aryl group; an aralkyl group; a cycloalkyl group; or a heterocyclic group;

   R₂   is hydrogen; alkyl, which may be substituted or unsubstituted; alkenyl; aryl; or an amino group -NR₄R₅;

   R₃   is hydrogen or a group -COR₉ or -COOR₁₀ releasable during development;

   R₄ and R₅   have the same meaning as R₁ or represent a group -COR₆, -CONHR₇ or -COOR₈;

   R₆   is an alkyl or cycloalkyl group containing up to 8 carbon atoms which may be substituted or unsubstituted; allyl; benzyl; aryl;

   R₇   is hydrogen or has the same meaning as R₆;

   R₈, R₉ and R₁₀   represent an alkyl or cycloalkyl group, which may be substituted or unsubstituted, containing up to 8 carbon atoms, or aryl

   or to formula (II):

   

   in which Z represents the remaining members for completing an optionally substituted benzoxazole, naphthoxazole, napthoxazine or phenyl-sustituted oxazole ring containing at least one acidic group in the aromatic part,
   and the colourless thiazolium, selenazolium or tellurazolium compounds are understood to be those which, in the form of a solution in water or an organic solvent, have no absorption maximum in the range from 400 to 700 nm.
2. A photosensitive silver halide recording material as claimed in claim 1, characterized in that the heterocyclic mercapto compound corresponds to formula (III):

   

   in which

   R₁₁ to R₁₄   may be the same or different and represent hydrogen or alkyl; two of the substituents R₁₁ to R₁₄ together may form the member required to complete a ring, more especially a fused phenyl ring, with the proviso that at least one of the substituents R₁₁ to R₁₄ contains an acidic substituent or is an acidic substituent.
3. A photosensitive silver halide recording material as claimed in claim 1, characterized in that the thiazolium, selenazolium and tellurazolium compounds correspond to formula (IV):

   

   in which

   X   represents S, Se, Te,

   R₁₅   represents H, alkyl or alkenyl containing up to 8 C atoms which may even be substituted,

   R₁₆   represents alkyl, alkenyl or alkynyl containing up to 8 C atoms which may even be substituted by hydroxy, alkoxy, carboxy, carbalkoxy, sulfo or halogen,

   R₁₇, R₁₈, R₁₉ and R₂₀   represent H, methyl, ethyl, halogen, methoxy, carboxy, carbomethoxy, carbamoyl, hydroxy, cyano, acetamido or

   R₁₇ and R₁₈, R₁₈ and R₁₉ and R₁₉ and R₂₀   in pairs together represent the ring members required to complete a non-heterocyclic 5- or 6-membered ring,

   An^(-)   is an anion and

   n   is 0 where R₁₆ is a sulfo group, but is otherwise 1.
4. A photosensitive silver halide recording material as claimed in claim 1, characterized in that the thiazolium compounds correspond to formula (V):

   

   in which

   R₂₁, R₂₂, and R₂₃   represent H, alkyl or alkenyl with up to 8 C atoms, which may even be substituted,

   R₂₄, R₂₅, R₂₆, R₂₇ and R₂₈   represent H, methyl, ethyl, halogen, cyano, methoxy, ethoxy.
5. A photosensitive silver halide recording material as claimed in claim 1, characterized in that the silver halide emulsion layer contains both at least one heterocyclic mercapto compound corresponding to formula I and at least one heterocyclic mercapto compound corresponding to formula II.
6. A photosensitive silver halide recording material as claimed in claim 1, characterized in that the silver halide emulsion layer contains both at least one heterocyclic mercapto compound corresponding to formula I and at least one heterocyclic mercapto compound corresponding to formula III.