DE10160853A1 - Color photographic material with reduced fog without sacrifice in sensitivity uses a long-chain xanthate as stabilizer to counteract the fogging effect of sulfur-, selenium or tellurium ripeners - Google Patents

Abstract

A photographic material has a layer containing a silver bromideiodide or a silver bromidechlorideiodide emulsion of iodide content at least 0.5 mol.%, the layer also containing a long-chain xanthate and the emulsion being ripened with a sulfur-, selenium or tellurium ripener free of the xanthate. A photographic material has a layer containing a silver bromideiodide or a silver bromidechlorideiodide emulsion of iodide content at least 0.5 mol.%, the layer also containing a long-chain xanthate of formula R'-(-O-C(=S)-S-)n Mm (I) and the emulsion being ripened with a sulfur-, selenium or tellurium ripener free of the xanthate. R1 = optionally substituted alkyl or alkylene of at least 4C; n = 1 or 2; M = a counterion; and m = a value appropriate to the uncharged compound.

Description

The invention relates to a photographic recording material with a support and at least one photosensitive at least one silver halide emulsion containing layer.

It is known from US 5,667,957 that certain xanthates as Sulfur ripening agents can act. Especially with pure silver bromide emulsions such compounds and in the absence of the usual ripening additives such. B. Gold salts or thiocyanates, higher sensitivities than shown with thiosulfate, however only in connection with an x-ray development. For those in footage The usual silver bromoiodide emulsions are only the short-chain from US Pat. No. 5,667,957 Ethyl xanthate known to be beneficial over pure thiosulfate, longer chain Derivatives such as B. the isopropyl derivative are disadvantageous in such emulsions for described the sensitivity.

It is also known that chemical ripening with sulfur and especially with selenium or tellurium compounds with high emulsions Sensitivity arises, but maturation especially with selenium or tellurium compounds in many cases is associated with an increase in the veil. This leads to emulsions thus produced for highly sensitive photographic materials become unusable. Stabilizers from the ranks of the Mercaptoazole, the Mercaptotetrazole, the Mercaptothiadiazole and the 3-Mercapto-1,2,4-triazole are for it known to counteract the increase in fog during chemical ripening. However, part of the sensitivity gained is then lost again.

It has surprisingly been found that the salts of xanthogenic acids, which contain alkyl residues with a carbon number higher than C ₃ , are outstandingly suitable for counteracting the fog-producing effects of sulfur and especially selenium or tellurium compounds in the chemical ripening of silver bromide iodide emulsions, without sacrificing the sensitivity gained for the stabilization effect. In the case of emulsions containing iodide, such long-chain compounds no longer act as known as sulfur ripening agents, but quite surprisingly as ripening stabilizers which, in interaction with sulfur, selenium or tellurium ripening agents, lead to emulsions with a very high sensitivity and an excellent sensitivity to fog ratio.

The invention thus relates to a photographic recording material with a support and at least one light-sensitive layer containing at least one silver bramide iodide or silver bromide chloride iodide emulsion with an iodide content of at least 0.5 mol%, characterized in that the layer is a compound of the formula (I)


contains what
R ^{1 is} an alkyl, substituted alkyl, alkylene or substituted alkylene radical with at least 4 C atoms,
n 1 or 2,
M a counter ion and
m is a value that leads to an uncharged connection,
the emulsion has been ripened with at least one ripening agent from the group of the sulfur, selenium or tellurium ripening agents and the ripening agent is not a compound of the formula (I).

Chemical ripening is preferred with the participation of gold compounds, z. B. in the form of gold (I) thiocyanate complexes. It turned out that due to the presence of gold salts, the effect as a ripening stabilizer is even stronger is pronounced and therefore very high sensitivity with very low veil are achievable. Regardless of the addition of gold, it is also advantageous Add water-soluble thiocyanate salts during chemical ripening, such as. B. Alkali metal thiocyanates or ammonium thiocyanate.

The xanthates according to the invention are known. They are hydrophilic and can the emulsion to be sensitized or already sensitized to any Time between the precipitation of the emulsion and its introduction into the pouring batch in Form of an aqueous solution can be added, so either before time the addition of the dyes or together with the sensitizing dyes. It other addition sequences are also possible. The addition before or during is preferred chemical ripening.

When using alkali xanthates as a ripening additive, the Sensitivity of the xanthates to acid are taken into account.

The alkyl or alkylene radical can in particular be alkyl, aryl or hetaryl radicals and particularly preferably substituted by phenyl, alkoxyphenyl, furyl and thienyl his. The counterions are, for example, lithium, sodium, potassium and Suitable ammonium ions.

The xanthates according to the invention are prepared in a known manner by Reaction of alcohols or diols with alkali and carbon disulfide, or by reacting alcoholates with carbon disulfide, as described in Houben-Weyl; Methods of organic chemistry; 4th edition volume E4 (G. Thieme; Stuttgart), pages 426-433. Older information can be found in Houben-Weyl; methods organic chemistry; Volume 9 (G. Thieme; Stuttgart), page 810.

The alkali metal xanthates of the formula (I) are used in particular in an amount of 10 ^-9 to 10 ^-3 mol / mol silver halide, preferably 10 ^-6 to 10 ^-4 mol / mol silver halide.

Suitable formula examples are listed below:

Particularly suitable sulfur ripening agents are water-soluble thiosulfate salts, such as. B. Alkali metal thiosulfates.

Particularly suitable selenium and tellurium ripening agents are heterocyclic selons or Tellurones, especially tri- or tetrasubstituted or cyclic selenium or Telluroureas, phosphane selenides or tellurides with three ligands that pass through Carbon or O or N are connected to the phosphorus atom as heteroatoms, in particular triarylphosphanselenide, further diaryldiselenide or Diarylditellurides, arylselenoamides, isoselenazolones, arylselenocyanates with a polar group, Acylmethylselenocyanate, cyclic telluroether with a 5- to 8-membered ring and transition metal organic tellurides.

Particularly preferred selenium and tellurium ripening agents are listed below.

In an advantageous embodiment, a mixture is different Chalcogen compounds used as chemical ripening agents, especially one Mixture of at least one sulfur and one selenium ripening agent, one sulfur and a tellurium ripening agent or a sulfur, a selenium and one Tellurreifmittel.

Chemical ripening in the presence of the xanthates according to the invention can also be carried out special advantages with the addition of spectral sensitizing dyes be performed.

The silver halide crystals can be homogeneous or inhomogeneous in zones be single crystals or single or multiple twinned crystals his. The emulsions can consist of mostly compact, mostly rod-shaped or predominantly tabular crystals exist and they can also epitaxial growths included. In the case of tabular crystals, those are included an aspect ratio above 3: 1 preferred, those with a Neighboring edge ratio close to 1 is particularly preferred.

The emulsion crystals can also be doped with certain foreign ions influence the shape of the gradation or the Schwarzschild effect or the stability improve the latent image, especially with complex bound multivalued ones Transition metal cations, for example with hexacyanoferrate (II) ions, Hexacyanoruthenate (II) ions or with noble metal cations, which are trivalent and one octahedral ligand environment, for example with ruthenium (III) -, Salt rhodium (III), osmium (III) or iridium (III).

The emulsions can be largely homodisperse or heterodisperse, you can accordingly by conventional precipitation, by one to multiple double enema or with the process of micrate solution become. They can also be so-called conversion emulsions.

The emulsions can also be sensitized with reducing agents. The reduction ripening can also take place in the course of the precipitation of the emulsion crystals in the Depth of the crystal can be built up, the reduction ripening nuclei in the further Growth of the crystals are covered. As a reducing ripening agent divalent tin compounds, phosphane tellurides, N-aryl hydrazides, salts of Formamidine-C-sulfinic acid, boranates or other complex hydrides, but also macrocyclic polyamines and metal complexes made therefrom can be used. Organically soluble, quickly and completely adsorbable on the silver halide Reducing ripening agents are preferred.

The emulsions according to the invention are used for long-term stabilization in color photographic materials particularly preferred together with Palladium (II) compounds used.

The highly sensitive emulsions according to the invention are particularly good for Suitable film materials, in other words for materials with a transparent support. Emulsions according to the invention with an iodide content are for this purpose of up to 10 mol% and a bromide content of at least 80 mol% in particular advantageous.

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 dye bleach process. An overview can be found in Research Disclosure 37038 (1995) and Research Disclosure 38957 (1996).

The photographic materials consist of a support on which at least one photosensitive silver halide emulsion layer is applied. As a carrier thin films and foils are particularly suitable. An overview of Carrier materials and auxiliary layers applied to their front and back are in Research Disclosure 37254, Part 1 (1995), p. 285 and in Research Disclosure 38957, Part XV (1996), p. 627.

The color photographic materials usually contain at least one each red sensitive, green sensitive and blue sensitive Silver halide emulsion layer and optionally intermediate layers and protective layers.

Depending on the type of photographic material, these layers can be arranged differently. This is shown for the most important products:
Color photographic films such as color negative films and color reversal films have 2 or 3 red-sensitive, cyan-coupling silver halide emulsion layers, 2 or 3 green-sensitive, purple-coupling silver halide emulsion layers and 2 or 3 blue-sensitive, yellow-coupling silver halide emulsion layers on the support in the order given below. The layers of the same spectral sensitivity differ in their photographic sensitivity, the less sensitive sub-layers generally being arranged closer to the support than the more sensitive sub-layers.

Between the green sensitive and blue sensitive layers is common a yellow filter layer is applied that prevents blue light from entering the below to reach lying layers.

The possibilities of the different layer arrangements and their Effects on photographic properties are described in J. Inf. Rec. Mats., 1994, Vol. 22, pages 183-193 and in Research Disclosure 38957 Part XI (1996), p. 624 described.

Color photographic paper, which is usually much less sensitive to light as a color photographic film, points in the order given below usually a blue-sensitive, yellow-coupling one on the carrier Silver halide emulsion layer, a green sensitive, purple coupling Silver halide emulsion layer and a red sensitive, cyan coupling Silver halide emulsion layer; the yellow filter layer can be omitted.

Deviations in the number and arrangement of the photosensitive layers can occur to achieve certain results. For example, you can all highly sensitive layers in one layer package and all low-sensitivity layers to another layer package in a photographic film be summarized to increase the sensitivity (DE-25 30 645).

Essential components of the photographic emulsion layers are binders, Silver halide grains and color couplers.

Information on suitable binders can be found in Research Disclosure 37254, part 2 (1995), p. 286 and in Research Disclosure 38957, Part II.A (1996), p. 598.

Information about suitable silver halide emulsions, their preparation, maturation, Stabilization and spectral sensitization including appropriate ones Spectral sensitizers can be found in Research Disclosure 37254, Part 3 (1995), p. 286, in Research Disclosure 37038, Part XV (1995), p. 89 and in Research Disclosure 38957, part V. A (1996), p. 603.

Photographic materials with camera sensitivity usually contain Silver bromide iodide emulsions, which may also contain small amounts of silver chloride can contain. Photographic copy materials contain either Silver chloride bromide emulsions with up to 80 mol% AgBr or silver chloride bromide emulsions with over 95 mol% AgCl.

Information on the color couplers can be found in Research Disclosure 37254, Part 4 (1995), p. 288, in Research Disclosure 37038, Part II (1995), p. 80 and in Research Disclosure 38957, Part X.B (1996), p. 616. The maximum absorption of the dyes formed from the couplers and the color developer oxidation product is preferably in the following ranges: yellow coupler 430 to 460 nm, Purple couplers 540 to S60 nm, cyan couplers 630 to 700 nm.

In color photography films, to improve sensitivity, Kingship, sharpness and color separation often used compounds in the reaction with the developer oxidation product release compounds that are photographic are effective, e.g. B. DIR couplers that release a development inhibitor.

Information on such compounds, in particular couplers, can be found in Research Disclosure 37254, Part 5 (1995), p. 290, in Research Disclosure 37038, Part XIV (1995), p. 86 and in Research Disclosure 38957, Part X.C (1996), p. 618.

The mostly hydrophobic color coupler, but also other hydrophobic components of the Layers are usually found in high-boiling organic solvents dissolved or dispersed. These solutions or dispersions are then in one emulsified aqueous binder solution (usually gelatin solution) and lie after drying the layers as fine droplets (0.05 to 0.8 µm Diameter) in the layers.

Suitable high-boiling organic solvents, methods for incorporation into the Layers of photographic material and other chemical methods Introducing connections into photographic layers can be found in Research Disclosure 37254, Part 6 (1995), p. 292.

The usually between layers of different spectral sensitivity Arranged non-light-sensitive intermediate layers can contain agents that an undesirable diffusion of developer oxidation products from a photosensitive to another photosensitive layer with different prevent spectral sensitization.

Suitable connections (white coupler, scavenger or EOP catcher) can be found in Research Disclosure 37254, Part 7 (1995), p. 292, in Research Disclosure 37038, Part III (1995), p. 84 and in Research Disclosure 38957, part X.D (1996), p. 621 ff.

The photographic material can furthermore UV-absorbing compounds, whiteners, spacers, filter dyes, formalin scavengers, light stabilizers, antioxidants, D _Min dyes, plasticizers (latices), biocides and additives to improve the coupler and dye stability, to reduce the color fog and for Reducing yellowing and other included. Suitable compounds can be found in Research Disclosure 37254, Part 8 (1995), p. 292, in Research Disclosure 37038, parts N, V, VI, VII, X, XI and XIII (1995), p. 84 ff and in Research Disclosure 38957, parts VI, VIII, IX and X (1996), pp. 607 and 610 ff.

The layers of color photographic materials are typically hardened, i.e. that is Binder used, preferably gelatin, is replaced by suitable chemical Process networked.

Suitable hardener substances can be found in Research Disclosure 37254, Part 9 (1995), P. 294, in Research Disclosure 37038, Part XII (1995), p. 86 and in Research Disclosure 38957, Part II.B (1996), p. 599.

After photographic exposure, color photographic materials become their character processed according to different processes. Details of the Procedures and chemicals required for this are in Research Disclosure 37254, Part 10 (1995), p. 294, in Research Disclosure 37038, parts XVI to XXIII (1995), p. 95 ff and in Research Disclosure 38957, parts XVIII, XIX and XX (1996), p. 630 ff published together with exemplary materials.

Examples example 1 Highly sensitive emulsion with tabular crystals

(All data in µmol additive refer to 1 mol AgNO ₃ )

Example 1.1. (Comparison)

A silver bromide iodide emulsion with an average grain diameter of 1.5 µm, corresponding to the average diameter of the area of the same area, an aspect ratio of 7.5 and an average iodide content of 9 mol%, based on total silver, is given V-1 (20 µmol) 44 ° C matured to the sensitivity optimum.
V-1 ethyl-OCS ₂ K

Example 1.2. (Comparison)

Example 1.1. is repeated, but with the difference that 10 µmol V-2 are added instead of V-1.
V-2 iso-Propyl-OCS ₂ K

Example 1.3. (Comparison)

Example 1.1. is repeated, but with the difference that the following ripening agent composition is used instead of V-1:
Carbon tetrachloride (2 µmol),
Potassium thiocyanate (250 µmol),
V-1 (20 µmol) and
2-mercaptobenzothiazole (100 µmol); (Stabilizer not according to the invention).

Example 1.4. (Comparison)

Example 1.3. is repeated, with the difference that instead of V-1 10 µmol V-2 can be added.

Example 1.5. (Comparison)

A silver bromide iodide emulsion with an average grain diameter of 1.5 μm, corresponding to the average diameter of the area with the same area, an aspect ratio of 7.5 and an average iodide content of 9 mol%, based on total silver, is also included
Carbon tetrachloride (2 µmol),
Potassium thiocyanate (250 µmol),
Sodium thiosulfate (6 µmol),
Triphenylphosphane selenide (4 µmol) and
2-mercaptobenzothiazole (100 μmol) (stabilizer not according to the invention)
matured at 44 ° C to the optimum sensitivity.

Example 1.6. (Comparison)

Example 1.5. is repeated, but with the difference that the Stabilizer 2-mercaptobenzothiazole (100 μmol) according to the invention after ripening is added.

Example 1.7. (Comparison)

Example 1.5. is repeated, with the difference that instead of the 2-mercaptobenzothiazole V-2 (100 µmol) is used.

Example 1.8 (Invention)

Example 1.5. is repeated, with the difference that instead of the 2-mercaptobenzothiazole XRS-1 (100 µmol) is used.

Example 1.9. (Invention)

Example 1.8. is repeated, but with the difference that the The tire stabilizer XRS-1 according to the invention is only added after the maturation has ended.

Example 1.10. (Comparison)

Example 1.5. is repeated, but with the difference that the following ripening agent is used instead of the ripening agent composition mentioned:
Carbon tetrachloride (2 µmol),
Potassium thiocyanate (250 µmol),
Sodium thiosulfate (6 µmol),
Trispyrrolidinophosphantelluride (4 µmol) and
2-mercaptobenzothiazole (100 µmol); (Stabilizer not according to the invention).

Example 1.11. (Comparison)

Example 1.10. is repeated, but with the difference that the Ripening stabilizer 2-mercaptobenzothiazole according to the invention only after ripening has ended is added.

Example 1.12. (Invention)

Example 1.10. is repeated, with the difference that instead of the 2-Mercaptobenzthiazole XRS-5 (100 µmol) is used.

Example 1.13. (Invention)

Example 1.11. is repeated, but with the difference that the The inventive tire stabilizer XRS-S is added after the maturation.

Example 1.14. (Invention)

Example 1.5. is repeated, but with the difference that the following ripening agent is used instead of the ripening agent composition mentioned:
Carbon tetrachloride (2 µmol),
Potassium thiocyanate (250 µmol),
Sodium thiosulfate (6 µmol),
N-methylbenzothiazolselenone-2 (4 µmol) and
Stabilizer XRS-8 according to the invention (100 μmol).

Example 1.15. (Invention)

Example 1.14. is repeated, but with the difference that the The tire stabilizer XRS-8 according to the invention is only added after the maturation has ended.

Production of photographic layers

The emulsions are stabilized with 100 μmol hydroxymethyltetraazaindene and, after the addition of a color coupler emulsate, are applied with the following orders (in g per m ² ) to a 120 μm thick substituted carrier made of cellulose triacetate. Teal coupler C-1 0.3 tricresyl 0.45 gelatin 0.7 Emulsions of Examples 1.1 to 1.15 (in each case g AgNO ₃ ) 0.85

The individual sheets were coated and hardened with a protective layer of the following composition:
Hardener H-1 0.02 gelatin 0.01

The individual samples were processed immediately after the casting. For this purpose, they were exposed to daylight behind a graduated gray wedge and then processed according to the color negative process described in "The British Journal of Photography" 1974, p. 597. The sensitivities were determined after densitometric measurement in each case at a density of 0.2 over D _min in relative ISO units. The sensitivity of experiment 1.5. was set as 100.

The results are shown in the table below:

The blocks used have the following formulas:

The results show completely surprisingly that only with the invention Maturing stabilizers silver bromide iodide emulsions are accessible after the Color development both a very high sensitivity and a low one Have veils.

Claims (9)

1. Photographic recording material with a support and at least one light-sensitive layer containing at least one silver bromide iodide or silver bromide chloride iodide emulsion with an iodide content of at least 0.5 mol%, characterized in that the layer is a compound of the formula (I)


contains what
R ^{1 is} an alkyl, substituted alkyl, alkylene or substituted alkylene radical with at least 4 C atoms,
n 1 or 2,
M a counter ion and
m is a value that leads to an uncharged connection,
the emulsion has been ripened with at least one ripening agent from the group of the sulfur, selenium or tellurium ripening agents and the ripening agent is not a compound of the formula (I). 2. Recording material according to claim 1, characterized in that the chemical ripening is carried out in the presence of a gold compound. 3. Recording material according to claim 1, characterized in that as Ripening agent A sulfur ripening agent is used. 4. Recording material according to claim 1, characterized in that as A thiosulfate salt is used as a ripening agent. 5. Recording material according to claim 1, characterized in that as A selenium ripening agent is used. 6. Recording material according to claim 1, characterized in that as Ripening agent is a substituted or unsubstituted triphenylphosphine selenide is used. 7. Recording material according to claim 1, characterized in that as Ripening agent is a mixture of at least one sulfur and at least one a selenium ripening agent is used. 8. Recording material according to claim 1, characterized in that it is a color photographic material with a transparent support is. 9. Recording material according to claim 1, characterized in that the Emulsion has a bromide content of at least 80 mol% and one Has iodide content of 0.5 to 10 mol%.