JPH11237710A - Photosensitive silver halide material increased in photosensitivity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the photosensitive material having a silver halide emulsion improved in sensitivity and in covering power by incorporating the silver halide emulsion containing organic positive holes trapping dopant. SOLUTION: The silver halide emulsion contained in the photosensitive material has silver halide grains containing the organic positive hole trapping dopant represented by one of formula I: R-COOM in which R is, an H atom or an alkyl or aryl or aralkyl group or the like; and M is an H or a metal atom or an organic group capable of forming a salt, or represented by formula II in which each of X and Y is an O, S, or Se atom; each of R1 and R2 is an H atom or an alkyl group or each may form a ring; E is a group combined with the carbon atom through a hetero atom having at least one free electron pair; and M- is a proton or an organic or inorganic counter ion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive material comprising on a support a silver halide emulsion exhibiting improved photosensitivity by using a new type of doping agent, and to the preparation of said photosensitive material. About the method.

[0002]

The photographic industry deals with photographic materials that must respond to light with a well-defined minimum amount of energy. This light energy induces chemical or physical activity that leads to changes in the irradiated material that are immediately visible or only present essentially, and are later processed by additional processing, also referred to as processing steps. Can be visualized with However, for a long time there has been a strong increasing demand for photosensitive materials with improved sensitivity, materials that respond to reduced amounts of light energy. One of the most important possibilities is found in photosensitive materials where there is a major photoactivity change on the atomic or molecular basis, which atomic or molecular basis is used to visualize the first light interaction in the material. In two steps, it can be increased by several orders of magnitude. This "two-step" imaging mechanism is encountered, for example, in silver halide materials forming the subject of the present invention. It will be clear that the sensitivity of this type of material is determined by the efficiency with which the various steps between light interaction with the silver halide and formation of the visible image can take place. The present invention will be particularly focused on how to achieve the first molecular light induced changes in silver halide crystals (also called latent images). This change after development results in the formation of a visible image.

[0003] The efficiency of latent image formation depends on many factors and can therefore be affected in various ways. Best results are achieved if each photoelectron in the silver halide crystal reaches the deepest electron trap while forming a latent image. This means that recombination between electrons and holes created after light absorption is prevented as much as possible. Many solutions have been proposed, all of which have limited results. People are trying to reduce the depth of electron traps, mainly to increase the probability of capture.
For example, chemical sensitization with sulfur, gold, selenium and other compounds or combinations thereof has been mostly used for this purpose.

Another method of preventing recombination of electrons and holes after formation is the temporary trapping of these species in local traps having intermediate trap depths. This can be done, for example, by creating strain inside the crystal lattice by local incorporation of small amounts of grain or increased amounts of iodide in the core. This approach leads to increased sensitivity by reducing electron-hole recombination, and other important features such as developability desired in current photographic materials are reduced by the presence of iodide.

[0005] Increasing the sensitivity of silver halide emulsions can also be achieved by increasing the efficiency of electron transfer from the spectral sensitizer to silver halide grains, which can in principle be carried out with supersensitizers. .

In view of the activity of sensitizing dyes, an increase in sensitivity can also be achieved by reducing the dye desensitization developed by increasing the dye concentration at the grain surface. This can be done for example by combining special cyanine and merocyanine dyes with electron donating compounds such as ascorbic acid as described in US-A 4,897,343. An electron donating compound bound to a silver halide absorbing group or a sensitizing dye is used to obtain an additional sensitizing effect. Examples are US-A 5,436,121, US
No. 5,478,719 and US Pat. No. 4,607,006.

Another important alternative to reducing recombination is to introduce hole traps into the silver halide crystals, such as silver clusters or some metal ions or complexes. One of the metal salts that can be used is, for example, US-A 516
6044 and iron as described in US Pat. No. 5,420,001, where the iron ions are rich in silver chloride (Ag
Cl 90 mol% or more) is mixed into the silver halide emulsion. The increase in sensitivity is caused by ferrous or ferric salts and the (inorganic or organic) anion can be chosen freely.
The choice of anion does not affect the desired effect, as has been widely proven. Further hole trapping entities already mentioned are silver clusters. These can be achieved by reduction sensitization achieved by treating the emulsion during precipitation with reductors such as tin compounds, polyamine derivatives, human azine, ascorbic acid and analogs, or by using well-defined pH- and / Or pAg
-Can be made in crystals depending on conditions. US-A
No. 3,892,574 describes a process in which small silver spots (which do not give a spontaneously developable fog) are produced under reducing conditions during or before silver halide precipitation or physical ripening. The same can be said for the silver halide production process as described in US-A 3,957,490, in which at the end of the reduction time the oxidant has been introduced into the silver halide emulsion before chemical sensitization. Most of the methods involving silver cluster formation by reduction sensitization produce (more or less) fog, which is known as a serious problem. According to experimental evidence, these silver clusters can be easily formed on {111} AgBr crystal faces, while it is difficult on eg {100} AgBr or {100} AgCl crystal faces. It has been found that For this reason, there is a need for a more general method that can form hole trapping moieties in all types of silver halide crystals to improve sensitometric properties.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light-sensitive material containing a silver halide emulsion having improved sensitivity and covering power.

It is a further object of the present invention to provide a photosensitive silver halide emulsion containing silver halide grains containing a new category of dopant.

It is another object of the present invention to provide a method for producing a photosensitive material containing a silver halide emulsion which has been treated with said new category of dopant during precipitation.

[0011] Further objects and advantages of the invention will become apparent from the description accompanying the examples given hereinafter.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic hole-trapping dopant.
Is realized by a photosensitive material containing a silver halide emulsion having silver halide grains containing. In particular, the organic hole trapping dopant has the following formula (I) or (II)
In the formula, R represents hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a heteroaryl group, and M represents hydrogen or a salt. Or an organic group capable of forming

Embedded image Wherein X and Y are independently selected from O, S, Se;
m is 1, n is 1 or 2, R1 and R2 each independently represent hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl or aralkyl group or a substituted or unsubstituted heteroaryl group, R1 and R2 may be the same or different, and may form a ring. E is a group linked to the carbon atom by a heteroatom having at least one free electron pair, and M ⁺ is a proton or an organic or inorganic counterion.

[0013] The invention further provides a photosensitive material wherein said photosensitive material can be a photoadressable thermographic material. The present invention also provides a method for producing said photosensitive material comprising a support and at least one silver halide emulsion layer on one or both sides thereof, wherein the silver halide grains have the formula (I) or ( Doped with an organic hole trapping dopant according to II), optionally in the presence of an oxidizing agent.

[0014] Preferred embodiments of the invention are disclosed in the dependent claims.

[0015]

DETAILED DESCRIPTION OF THE INVENTION While the present invention will be described in connection with preferred embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the scope and spirit of the invention as defined by the appended claims.

The present invention as described above will be described in detail below. It has surprisingly been found that the sensitivity of photosensitive materials containing silver halide emulsions can be improved as described above by the introduction of organic molecules which can be described as hole trapping dopants. These compounds are organic compounds which can be incorporated into the silver halide during the growth phase of the precipitation of silver halide grains or during the process. These compounds are capable of releasing at least one, usually two, or generally a certain amount of two electrons (ie 2, 4, etc.) under certain circumstances or conditions. Contrary to hole trapping agents commonly known in the art, it is important that the organic hole trapping dopant of the present invention does not obtain its trapping activity from the lowest valent metal atom optionally surrounded by a ligand. It is. In contrast, it relates to organic molecules capable of delivering their electrons in a silver halide crystal after defragmentation of a portion of the molecule.

Important compounds which can be used as organic hole-trapping agents for this purpose are characterized by the following formula (I) or (II): R-COOM (I)

Embedded image

Organic molecules satisfying formulas (I) and (II) actually act as hole trapping agents after incorporation into the silver halide lattice. A hole trapping agent can be defined in most general terms as a compound that emits one or more electrons due to the reaction with holes formed in the silver halide crystal lattice after absorption of a photon.

R in formula (I) is represented in the first example by a hydrogen atom which means that formic acid or its inorganic or organic salts are used as hole-trapping dopants in the present invention. In a further example, R is an unsubstituted or substituted alkyl group that may contain all types of functional groups as substituents, such as hydroxyl groups, amine groups, carboxyl groups, carboxylic acid groups or other functional groups. Of particular importance are α-hydroxy-carboxylic acids or salts thereof and α-amino-carboxylic acids or salts thereof (the nitrogen atom of the amino group can be part of a ring structure).

It also means salts of polyacids such as oxalic acid, malonic acid, maleic acid, etc., but also salts of tri-, tetra- and higher carboxylic acids of the organic hole trapping dopants within the scope of the present invention. To be included in the formula.

In a further example, R represents an unsubstituted or substituted aryl group, an unsubstituted or substituted aralkyl group or an unsubstituted or substituted heteroaryl group, which may be a hydroxyl group, an amine group, a carboxyl group, a carboxylic acid group or another functional group. All types of functional groups may be included as the substituents.

M in the formula (I) is the same as in the formula (II).
Represents any of the metals of the periodic system
With a carboxylic acid of formula (II)
Metals which form a water-soluble salt with the acid groups are preferred. M is al
Potassium or alkaline earth metal or N⁺R³R⁴R⁵R
⁶(R³~ R⁶May be the same or different.
R ³~ R⁶Is hydrogen, unsubstituted or substituted alkyl
, Unsubstituted or substituted aryl or phosphonium, seleno
, Iodonium, telluronium or sulfonium
Gives the onium ion independently, such as
It can be a substituted or substituted ammonium cation.
In this group, alkaline earth metals are the most preferred in the present invention.
(Alkali metals are also preferred).

It is clear that the size of the molecule represented by formula (I) is an important factor for incorporation into a silver halide matrix, meaning, for example, that HCOOM is more effective than CH ₃ COOM. The metal valency can be 1, 2 or more, but one is preferred. Organic cations, such as anions which are part of the compounds represented by formulas (I) and (II), have no clear restrictions for their incorporation, but are preferably as compact as possible.

Typical examples of hole trapping agents according to formula (II) are given below (see compounds II.1 to II.11).

Embedded image

Α-Hydroxymethylsulfinic acid or its salts are commercially available (such as “Rongalit”) or are available from Mulliez and Naudy (Tetrahedron 49 (199).
3), pp. 2469-2476). In this document, reference is made to an older document describing the preparation of α-hydroxymethylsulfinic acid. The synthesis of α-aminomethylsulfinic acid is Mu
described by lliez et al. When R1 and R2 represent hydrogen, it is readily available from Rongalit (J. Org Chem. 61 (1996), p. 5648-5649). Further production methods are described in WO9804522A1 and Tetrahedron, 5
0 (18), p. 5401-5412.

In a preferred embodiment of the present invention, the photosensitive material comprises a silver halide emulsion crystal containing Rongalite according to formula (II) as an organic hole-trapping dopant, present internally as sulfinic acid or as its inorganic or organic salt.

The formation of silver halide emulsions can be carried out by introducing a soluble silver salt with a soluble halide salt as a reactant into an aqueous solution of a binder such as gelatin. After the first nucleation step in which nuclei are formed, growth will take place under continuous addition of both reactants. During the precipitation the entire process is p
It can be carried out under Ag- and / or pH-controlled conditions.

The compounds of the invention satisfying formula (I) or (II), or even a combination of both, can be introduced in various ways during the precipitation of the silver halide grains: via the silver salt inlet Or via a separate third inlet system. Care must be taken in the location of the third inlet used for the addition of the hole trapping agent of the present invention. It must be mounted in such a way that the hole trapping agent is supplied below the surface of the solution in which the silver halide is precipitated. In addition, the entrance itself must be located closer to the silver halide entrance than to the halide entrance. Injection of a hole trapping agent as close as possible to the silver salt inlet is preferred, and combined simultaneous addition of the hole trapping agent and the silver salt solution through one inlet is the ultimately most preferred configuration that can be used in the present invention. This can be said for all system configurations in which the solution of the hole trapping agent and the silver salt are mixed together before the formation of the silver halide itself.

The introduction is carried out in the whole of the silver halide emulsion grains or crystals.
It can be performed during the precipitation step. It is the growth process
Means starting from the beginning to the end. Introduction
At constant flow rate, increasing, decreasing or fluctuating flow rate
Or it can be done in a flow that is interrupted once or several times
Wear. This is because in silver halide grains the formulas (I) and / or
Or concentration distribution of all types of compounds satisfying (II)
Is possible. Addition is automatic if desired
Or a computer controllable
Hydrostatic pressure by a motor driven injection system or as driving force
Can be implemented below. Therefore organic hole trapping
The dopant can be located anywhere in the crystal,
It may be the whole crystal or the core or one or more surrounding said core
Means that you can put it in the shell. In the present invention
Preferably used organic hole trapping dopant
The amount is 10 per mol of silver halide.^-8-10^-2
mol, more preferably 5 × 10^-8~ 5 × 10^-3m
ol, most preferably 10 ^-7~ 5 × 10^-3in mol
is there.

An important factor in the present invention is the presence of an oxidizing agent during the addition of the compound according to formulas (I) and / or (II) in the precipitation step. The oxidizing agent is preferably present before the organic hole trapping dopant is injected during the precipitation of the silver halide emulsion crystals. The addition can be carried out immediately or at well-defined times, preferably in both cases under stirring conditions. The addition of the oxidizing agent may be started before the addition of the hole trapping agent and may be performed together with the addition of the hole trapping agent. The type of oxidant to be used depends on the oxidizing power required to obtain optimal hole trapping results, but actual experimental results may be affected by the amount of oxidant selected. The most preferred oxidizing agent in connection with the present invention is p-toluenethiosulfonic acid or a salt thereof, which may be a sodium salt, or optionally any other metal salt. This mode of action is special for the present invention and is described, for example, in U.S. Pat. No. 3,672,901 (the oxidizing agent is used at the beginning of the precipitation to produce particles in which internal reduction has been partially or completely excluded). (Introduced) is different from other methods used so far. The situation is the same as for the process in which the addition of the oxidizing agent is carried out at the end of the precipitation in the presence of a reducing agent as described in US Pat. No. 3,957,490.

Many parameters such as sensitivity, gradation, pressure sensitivity, high or low light reciprocity failure, stability, dye desensitization, and some other sensitometric aspects of light sensitive silver halide emulsions It can be varied by the choice of dopant as is known in the art, but can be varied in a variety of ways with the organic hole trapping dopants of the present invention. The activity of the dopant is influenced by the type of the dopant, its concentration and its position in the silver halide crystal.

The silver halide emulsion as described above can be produced by various methods according to a conventional method. Briefly, these methods always start with a nucleation step followed by a particle growth step. In emulsion production, the reactants are added to the reaction vessel in the form of preformed silver halide nuclei or grains which are readily soluble in the precipitation medium or in the form of a solution of silver and halide salts. The silver and halide salt solution herein may be surface or lower surface by an automated delivery system to maintain control of the pAg and / or pH in the reaction vessel and the rate of the reactant solution introduced into the reaction vessel or by hydrostatic pressure. It can be added through a delivery tube. pAg
And the adjustment of the pH value is even more critical with respect to the use of the compounds satisfying the formulas (I) and (II) according to the invention, while said adjustment clearly determines the activity of these hole-trapping dopants. Therefore, the pH value is preferably set to 1 to 10, and most preferably 2 to 8. Otherwise, the pAg value is preferably set to 2 to 9, and most preferably 3 to 8.

As taught for the compounds used in the present invention, the reactant solution or dispersion for the production of silver halide itself may be at a constant rate or at a constantly increasing, decreasing or varying rate. And, if desired, it can be added in combination with a stepwise delivery means. Further details on all possible methods of making silver halide emulsions that can be used in principle in the present invention can be found in Research Dis
closure, item No.38957, published September 1996, section
It is put together in IC.

According to the present invention there is also provided a light-sensitive material, said material comprising at least one silver halide grain prepared in the presence of an oxidizing agent and an organic hole-trapping dopant on one or both sides of the support. Comprising two silver halide emulsion layers, said material further comprising silver halide grains composed of at least one halide selected from the group consisting of chloride, bromide and iodide.

Other silver salts which can in principle be incorporated in limited amounts in the silver halide lattice are silver phosphate, silver thiocyanate,
Silver citrate and some other silver salts. Chloride and bromide as halides can be combined in certain proportions to form silver chlorobromide salts. However, iodide ions can be co-precipitated with chloride and / or bromide ions, whereby iodide having an iodide content dependent on the saturation limit of iodide in a silver halide lattice having a predetermined halide composition Form halides. Thus, up to a maximum of about 40 mol% in silver iodobromide and up to 13 mol% in silver iodochloride (both based on silver) can be established. The preferred silver halide emulsion is 30 m
ol% or less of iodide, silver bromoiodide having 8 mol% or less of iodide, and at least 10 mol%
Of silver bromide and 4 mol% or less of iodide.

For certain applications, a well-defined amount of iodide is applied on the crystal surface under controlled conditions to obtain reproducible sensitometric results after image-wise exposure and subsequent processing. It might be important. This is E
P-A 0561415 and EP-A 0563708
Can be carried out by using an iodide releasing agent as described in, and can be applied on the emulsion before, during or after chemical sensitization in addition to the conditions and methods of the present invention as described above. it can.

The composition of the halide present may vary in the crystal in a continuous or discontinuous manner. Emulsions containing crystals composed of various zones with different halide compositions are used for some photographic applications. Structures that differ in the halide composition between the central portion and the rest of the crystal (referred to as "core-shell emulsions") or structures having two or more crystalline portions differing in halide composition ("band emulsions") ) May occur. The change in halide composition is realized in an indirect manner or by direct precipitation by a transformation in which a halide composition is dissolved in the presence of so-called host grains which form a "shell" or "band" on a given grain. Can be The emulsions of the present invention can be made in almost the same way that is very specific for the emulsions of the present invention, in which the grains are of the formula (I) rather than by the halide composition normally found in emulsions used in the industry. ) And / or shells or cores which are only distinguished from one another by the presence of organic hole-trapping punts according to (II). Furthermore, it can be said that two types of the aforementioned core-shell structures may be present in the same particle and they do not need to cover each other. However, it is important to note that the organic hole trapping dopants of the present invention may be located anywhere in the crystal, while the presence in the outermost shell containing up to 95% silver in the grains is preferred. .

The crystals formed by the above method have a morphology that can be tabular or non-tabular. In the tabular crystal, the aspect ratio (ratio of equivalent circular diameter to thickness) can vary from low (<2) to high (> 8) past medium (2-8), and especially ultra-thin tabular In the case of a crystal, a high aspect ratio can be realized.
The main surface of the formed tabular grains is {111} or {10}.
It can have a 0 ° crystal habit and its structure is (respectively)
It must be stable or stabilized (eg, by a habit modifier). In the case of non-tabular grains, there are many possibilities that can be divided into crystals of regular shape or crystals with a combined habit.

[0039] Hydrophilic colloids are used as protective colloids or binders for any layer or emulsion of the photographic material of the present invention. Gelatin is an advantageously used hydrophilic colloid. Conventional methods for producing lime-treated or acid-treated gelatin are described, for example, in "The Science and Technology of Gela
tin ”, AG Ward and A. Courts, Academic Press197
It is described from page 7,295. Gelatin is Bull.Soc.
Sci. Phot. Japan, Nr16, page 30 (1996). However, the gelatin may be partially or totally replaced by synthetic, semi-synthetic, or natural polymers. Synthetic substitutes for gelatin are, for example, polyvinyl alcohol, poly-N-vinylpyrrolidone, polyvinylimidazole, polyvinylpyrazole, polyacrylamide, polyacrylic acid, and their derivatives, especially their copolymers. Natural substitutes for gelatin are, for example, other proteins such as zein, albumin and casein, cellulose, saccharides, starch, and alginates. Generally, semi-synthetic substitutes for gelatin are modified natural products, such as gelatin derivatives obtained by grafting of polymerizable monomers onto gelatin by conversion of gelatin with alkylating or acrylate agents or pre-curing treatments. Are pre-cured gelatins with blocked functional groups, cellulose derivatives such as hydroxyalkylcellulose, carboxymethylcellulose, phthaloylcellulose, and cellulose sulfates and potato starch.

JP-B-52-16365, Journal of
The Society of Photographic Science and Technolog
y of Japan, Vol.29 (1), 17, 22 (1966), ibid., Vol.30
(1) Further synthetic polymer compounds described in (10) may be used as a dispersion medium. A crystal habit suppressant described in EP-A 0 534 395 may be used.

Part of the gelatin may be further replaced by synthetic or natural polymeric materials.

Important substitutes for gelatin are disclosed in published EP-A 0 392 092, 0517961, 052.
Silica as described in 8476, 0649051 and 0704747. EP-A 05
There is provided a method of making a silver halide photosensitive photographic material incorporating a layer of silver halide precipitated in colloidal silica which acts as a protective colloid as described in 28476.

In this document silver halide is produced in colloidal silica, which leads to emulsion crystals which are stable at the end of the precipitation. However, it does not have a predictable average crystal diameter and grain size distribution. These problems are overcome for the production of crystals rich in silver chloride as described in EP-A 0 682 787. In that case, the undefined formation and growth of aggregates can be optimized by optimizing the clearly defined circumstances in which such crystals can be produced (for the stabilizing onium compound and for the regular silver chloroiodide crystal precipitation of the silica sol). Should be avoided.

The emulsion can be coagulated and washed after precipitation to remove excess soluble salts. These methods are
Research Disclosure, item No. 38957 (published September 1996), section III, with various alternatives such as diamond or ultrafiltration and ion exchange.

Additional gelatin or another hydrophilic colloid suitable as a binder material is added at a later stage in the emulsion preparation (eg, after washing) to optimize coating conditions and / or the required thickness of the coated emulsion layer. Can be established. Preferably, a ratio of gelatin to silver halide in the range of 0.3 to 1.0 (silver halide is expressed as equivalents of silver nitrate) is then obtained. Another binder may be added instead of or in addition to gelatin. Useful vehicles, vehicle extenders, vehicle-like additives and vehicle-related additives include, for example, Research Disclosure it
em No. 38957 (issued in September 1996), Chapter II.

The silver halide emulsion of the present invention produced by one of the aforementioned methods is preferably 0.01 μm or more and 2 μm or more.
Sphere equivalent diameter (S
(ED). The spherical equivalent diameter of the crystal (S
ED) represents the diameter of a sphere having the same volume as the average silver halide volume of the emulsion.

The emulsions may be surface sensitized emulsions which form a latent image mainly on the surface of the silver halide grains, or they are emulsions which form a latent image mainly inside the silver halide grains. be able to. The emulsions can also be negative working emulsions such as surface sensitized emulsions or unfogged internal latent image sensitive emulsions. However, latent fogging-type direct positive emulsions, which are positive working by development in the presence of a nucleating agent, and pre-fogged direct positive emulsions can be used in the present invention.

[0048] Sensitization can be performed in many different ways. Central chalcogen compounds (such as sulfur, selenium and tellurium), gold (such as platinum, palladium, rhodium, ruthenium, iridium and osmium)
It can be carried out by chemical sensitization with a platinum group metal of the periodic system of elements or with these sensitizers, the reaction of which can be influenced by the pAg, pH and temperature of the medium in which the chemical sensitization takes place. The chemical sensitization can be arbitrarily performed in the presence of, for example, a thioether compound, a thiocyanate derivative, a stabilizer, and the like. The emulsions can also be sensitized by what is referred to as reduction sensitization, as described above, and if desired, this can be combined with the aforementioned chemical sensitization methods.
A complete description of all the possibilities of sensitization that can be used in the present invention can be found in Research Disclosure, item No. 38957 (September 1996)
Month) and section IV.

In the next step, the silver halide emulsion is composed of cyanine, merocyanine, tri-, tetra- and polynuclear cyanines and merocyanines, oxanol, hemioxonol,
It may be spectrally sensitized with dyes from various types, including polymethine dyes, including styryl, merostyryl, and the like. Particular attention should be paid to the use of J-aggregated dyes in the present invention ("The Theory of Photographic Processes").
s ", TH James, 4th ed. (1977) 218-222
Page and T. Tani “Photographic Sensitivity. Theoryan
d Mechanisms ”, Oxford Univ. Press, New York-Oxfor
d, 1995). These J-aggregating dyes are preferably used in combination with J-aggregating "tuning" compounds or products or agents. These special "modulating" compounds can change the J-aggregate to some desired size. These so-called "J-aggregating-modulating compounds" are well known and are described, for example, in (AAMuenter et al., J. Phys. Chem., 96 (1).
992) Other compounds such as alcohols, surfactants, ketones, photographic stabilizers and various other products (as described in 2783) (eg, AH Herz, Phot. Sci. Eng.,
18 (1974) 323). An important J-aggregation-modifying compound preferably used in the present invention is a photographic stabilizer.

In some situations, one or more spectral sensitizers may be used if the majority of the spectrum is to be covered. A combination of several spectral sensitizers may be used as supersensitizers, which exhibit greater sensitization in some areas of the wavelength spectrum than sensitization resulting from the concentration of any one of the dyes alone or from the effect of the addition of the dye. May be used to obtain Generally, supersensitization can be achieved by using selected combinations of spectral sensitizing dyes and other additives such as stabilizers, development accelerators or inhibitors, optical brighteners, coating aids, and the like. For example, EP-A-0786690, EP-A-078669
1 and special applications as described in EP-A 0 786 692 can be used in the silver halide emulsions of the invention. A useful description of various other possibilities in spectral sensitization that is important for the present invention is
closure item No.38957 (issued September 1996), secti
can be found on V.

The photographic materials containing the silver halide emulsions may contain various compounds which play an effective role in the finishing or storage of the photographic material, either in the material itself or in post-exposure processing.
These compounds can be stabilizers and antifoggants. Antifoggants are defined as preventing fogging, while stabilizers have the function of protecting sensitometric properties. Antifoggants and stabilizers are used in the processing, storage or manufacturing process of the (exposed) photographic material. Antifoggants and stabilizers can be azoles, mercaptopyrimidines, mercaptotriazines, azaindenes and the like. Further suitable examples are described, for example, in Research Disclosure item No. 38957 (199).
(September 2006), section VII.

Hydrophilic colloid layer of photographic material (silver halide emulsion layer, backing layer, antihalo layer, etc.)
Is an inorganic or organic curing agent (Research Disclosure item No.
38957 (issued in September 1996, see section IIB), optical brightener (Research Disclosure item No. 38957 (19)
Published in September 1996), see section VI), light absorbing and scattering materials (Research Disclosure item No. 38957 (1996)
(September 1999), see section VIII), coating aid (Researc
h Disclosure item No.38957 (issued September 1996),
See section IXA), Antistatic agent (Research Disclosure
item No.38957 (issued September 1996), section IXC
), Matting agent (Research Disclosure item No.38957)
(Issued September 1996), section IXD) and development modifiers (Research Disclosure item No. 38957 (199)
(September 2006), see section XVIII).

The photographic material of the present invention may further comprise various other additives such as compounds which improve the dimensional stability of the photographic material, UV absorbers and spacing agents. Additives suitable for improving the dimensional stability of the photographic material include, for example, water-soluble or poorly water-soluble synthetic polymers such as alkyl (meth) acrylates, alkoxy (meth) acrylates,
A polymer of glycidyl (meth) acrylate, (meth) acrylamide, vinyl ester, acrylonitrile, olefin, and styrene, or the above and acrylic acid, methacrylic acid, α-β-unsaturated dicarboxylic acid,
Dispersion of hydroxyalkyl (meth) acrylate, sulfoalkyl (meth) acrylate, and styrene sulfonic acid).

Suitable UV absorbers are, for example, US-A 3
Aryl-substituted benzotriazole compounds as described in 533794, US-A 3,314,794 and 3352
No. 681, 4-thiazolidone compounds, JP-
A benzophenone compounds as described in A 56-2784, cinnamic acid ester compounds as described in U.S. Pat. Nos. 3,705,805 and 3,707,375, U.S. Pat.
229, and US-A
Research also describes benzoxazole compounds, such as described in US Pat. No. 3,700,455, and suitable optical brighteners.
Disclosure item No.38957 (issued September 1996), s
See Section VI.

The spacing agent generally has an average particle size of 0.2.
Those that are between 10 and 10 μm can be present. Spacing agents can be soluble or insoluble in alkali. Alkali-insoluble spacing agents usually remain permanently in the photographic material, while alkali-soluble spacing agents are usually removed therefrom in an alkaline processing bath. Suitable spacing agents can be made, for example, from polymethyl methacrylate, from copolymers of acrylic acid and methyl methacrylate, and from hydroxypropyl methylcellulose hexahydrophthalate. Other suitable spacing agents are described in U.S. Pat. No. 4,614,708.

Any thickener may be used to adjust the viscosity of the coating solution prior to coating. The condition is that they do not particularly affect the photographic characteristics of the silver halide emulsion in the coated photographic material. Preferred thickeners include aqueous polymers such as polystyrene sulfonic acid, dextran, sulfate, polysaccharide, polymers having sulfonic, carboxylic or phosphoric groups and colloidal silica. Polymeric thickeners well known from the literature that cause thickening of the coating solution may be used in combination with colloidal silica. Patents relating to thickeners include, for example, US-
A 3167410, Belgian Patent No. 558143 and JP-A 53-18687 and 58-36768. Negative effects on physical stability resulting from the addition of polymeric compounds can be avoided by removing those compounds and by limiting the extra addition of colloidal silica.

To achieve a high degree of cure, the layer binder should of course be provided with a large number of acceptable functional groups,
Those functional groups can provide a sufficiently resistant layer by reaction with a suitable curing agent. Such functional groups are in particular amino groups, but can also be carboxyl groups, hydroxy groups and active methylene groups. A hardener may be added to the stress-resistant layer covering one or more light-sensitive silver halide emulsion layers before or during the coating procedure, or to one or more of said emulsion layers. Particularly when the binder used is gelatin, the binder of the photographic material is a suitable hardener, for example of the epoxide type, of the ethyleneimine type, of the vinylsulfone type (for example 1,3-vinylsulfonyl-2).
-Propanol), chromium salts (e.g. chromium acetate and chromium alum), aldehydes (e.g. formaldehyde, glyoxal and glutaraldehyde), N-
Methylol compounds (eg, dimethylolurea and methyloldimethylhydantoin), dioxane derivatives (eg, 2,3-dihydroxy-dioxane), active vinyl compounds (eg, 1,3,5-triacryloyl-hexahydro-s-triazine), active halogen compounds (E.g., 2,4-dichloro-6-hydroxy-s-triazine) and mucohalic acids (e.g., mucochloric acid and mucophenoxychloric acid). These compounds can be used alone or in combination. The binder can also be hardened with a fast-reacting hardener such as a carbamoylpyridinium salt. Formaldehyde and phloroglucinol can be added to the protective layer and the emulsion layer, respectively. More suitable possibilities for curing
Research Disclosure item No. 38957 (issued September 1996), section IIB.

The photographic materials may be coated on various supports, which can be soft or hard. Soft materials include plastic films and paper, while hard materials include glass, metal, and the like. The surface of the support is generally subjected to an undercoating treatment (such as corona discharge or ultraviolet irradiation) to increase the adhesion of the silver halide emulsion layer (Research Disclosure item No. 3).
8957, September 1996, section XV and references cited therein). The photographic material can be exposed to actinic radiation to form a latent image, especially in the visible, near ultraviolet and near infrared regions of the spectrum (Research Disclosure
item No. 38957, published September 1996, see section XVI).

Various exposure means can be used for exposing the photographic material of the present invention. As light source, any optical (light) source that emits radiation corresponding to the sensitivity wavelength of the photographic material can be used. Examples of commonly used light sources include natural light, incandescent lamps, halogen lamps, mercury lamps, fluorescent lamps and all types of flash light sources. A light source that emits light in the ultraviolet to infrared region can be used as a recording light source. The photographic material can be exposed, for example, to a gas laser, a semiconductor laser, a light emitting diode or a plasma light source. Similarly, the material can be exposed to an LCD light source or to a fluorescent surface provided by an X-ray or electron beam stimulated phosphor. Direct X-rays, β- or γ-rays are included as possible radiation sources in the present invention.

The latent image formed in the silver halide crystals after exposure can be processed to form a visible image.
Therefore, various methods are known and many developing, fixing and stabilizing agents have been described for the formation of photographic silver images. The know-how for processing photographic silver halide materials that can be used in principle in connection with the present invention is Research Disclosureite
m No. 176043, issued December 1978, section XIX to XX
IV and Research Disclosure item No. 38957, 1996
It is listed in section XIX, published September 2015.

In the usual processing method, most of the materials are developed with a liquid containing hydroquinone as the main developing agent usually combined with a so-called auxiliary developing solution. In another processing method, hydroquinone is incorporated into the photographic material itself, while the processing solution is simply an alkaline solution. However, it is important to recognize that hydroquinone is questionable in various respects, especially in ecological and medical terms. The present invention also relates to ecological processing methods in which hydroquinone is at least partially replaced by ascorbic acid as a developing agent. Ascorbic acid is to be interpreted in a broad sense and includes ascorbic acid isomers, derivatives, salts and similar compounds, including some reductone and reductic acid derivatives. The most preferred compounds are (1-) ascorbic acid, iso-ascorbic acid, reductic acid and salts thereof. Useful combinations of developers containing ascorbic acid developing agents which should preferably be used within the scope of the present invention are described in Research Disclosure item No. 37152, 19
It is described for many uses (graphics, radiography, etc.) on March 1, 1995, pages 185-224.

The photographic emulsions according to the invention can also be used in multilayer multicolor materials. These materials comprise a support and two or more silver halide emulsion layers having different spectral sensitivities. Multilayer color photographic materials generally comprise at least one red-sensitive emulsion layer, at least one green-sensitive emulsion layer and at least one blue-sensitive emulsion layer on a support.
The non-light-sensitive layer may be provided between two or more emulsion layers having the same color sensitivity. Otherwise, another emulsion layer having a different color sensitivity can be provided between two or more emulsion layers having the same color sensitivity. A light reflecting layer, such as a layer of silver halide grains, can be provided below the sensitive layer to increase sensitivity, especially below the high blue sensitive layer.

The silver halide materials can also contain various types of couplers that can be incorporated into color photographic materials. The red-sensitive emulsion layer generally contains a cyan coupler, the green-sensitive emulsion layer generally contains a magenta coupler, and the blue-sensitive emulsion layer generally contains a yellow coupler. All information that can be important for the application of the present invention in these types of materials is available from Research Discl.
osure item No.38957, published September 1996, section X
Widely described. Much information on the various color applications that also fall within the scope of the present invention is disclosed in US-A 5,532.
120 can also be found.

The processing required to form a visible dye image for a color material involves contacting the material with a color developing agent to reduce developable silver halide and oxidize the color developing agent, which in turn is coupled to a coupler. Usually forms a dye by reacting with (Research Disclosure item N
o.38957, published September 1996, see section XX).

Special attention should also be paid to photothermographic applications that should not be ignored in the present invention. UV, visible or IR for this type of material
There are photosensitizers that can be catalyzed or participate in thermographic processes that result in a change in optical density or color after exposure to light. Examples of photothermographic materials
3M Company's “Dry Silver” photographic material,
It was written by DA Morgan as “Handbook of Imaging Sc
ience ", edited by AR Diamond, p. 43, published by Marcel Dekker, 1991.

Photoaddressable thermosensitive materials usually include a light-sensitive silver halide, a reducing agent for silver ions and a binder. The heat-sensitive material may further comprise an organic silver salt which is substantially non-photosensitive in catalytic relationship with the photosensitive silver halide and in thermal relationship with a reducing agent for silver ions. The material is a substantially light-insensitive organic silver salt component and a catalyst-related silver halide,
Spectral sensitizer, optionally with a supersensitizer in intimate sensitization with the silver halide grains and active in the pre- or post-development stabilization or thermal development step of the material in the same layer or another layer It may include a layer system with other components. The only requirement is that the organic reducing agent and toning agent (if present) be in a thermal working relationship with the substantially light-insensitive organic silver salt. That is, the condition is that the reducing agent and the toning agent (if present) can diffuse substantially into a non-photosensitive organic silver salt (for example, a silver salt of a fatty acid) in the heat development step. It is an object of the present invention to provide a photosensitive imaging material, said material comprising a substantially light-insensitive organic silver salt, a photoaddressable comprising an organic reducing agent and a binder therefor in a thermal working relationship therewith. Thermographic material.

If the photosensitive silver halide grains of the present invention described above are used together with a substantially light-insensitive organic silver salt,
It is substantially non-photosensitive organic silver salt 0.1-90mo
1%, preferably from 0.2 to 50 mol
%, More preferably 0.5 to 35 mol%, most preferably 1 to 12 mol%. Preferred substantially light-insensitive organic silver salts are silver salts of organic carboxylic acids, especially aliphatic carboxylic acids known as fatty acids (the aliphatic carbon chain preferably has at least 12 C atoms).
For example, silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate (their silver salts are also referred to as "silver soap"), described in US-A 4,504,575. Silver dodecyl sulfonate and silver di- (2-ethylhexyl) -sulfosuccinate described in EP-A 0227141. GB-A for producing thermally developable silver images
Aliphatic carboxylic acids modified with thioether groups as described in 1111492 and GB-A 1439478
Other organic silver salts such as those described in, for example, silver benzoate and silver phthalazinone may be used as well. Further examples include silver imidazolates and the substantially light-insensitive inorganic or organic silver salt complexes described in U.S. Pat. No. 4,260,677.

A suspension of particles containing a substantially light-insensitive organic silver salt can be used as described in EP-A 0 754 969 in an aqueous solution of a silver salt and an aqueous solution or suspension of an organic carboxylic acid or a salt thereof. It may be obtained by using a method involving simultaneous metered addition of a suspension.

The silver halide emulsion described above may be added to a photoaddressable, thermally developable material in any manner which places it in catalytic proximity to a substantially light-insensitive organic silver salt. . A silver halide and a substantially light-insensitive organic silver salt formed separately (ie, formed elsewhere or "preformed") in a binder are mixed prior to use to form a coating solution. However, it is also effective to blend both of them for a long time. It is especially important when tabular silver halide grains are present, thus achieving a high specific surface area and close contact of the tabular grains. Further, a method comprising adding a halogen-containing compound to an organic silver salt to partially convert a substantially light-insensitive organic silver salt to silver halide as disclosed in US-A 3,457,075. It is also effective to use.

An important aspect of the present invention is the presence of an organic hole trapping dopant and optionally an electron trapping dopant according to formulas (I) and / or (II) in the organic silver salt material or particles. It may also be a combination of an organic hole-trapping dopant represented by formula (I) and / or (II) and one or more electron-trapping dopants, as already described for the silver halide crystal. This doping method can be combined with the addition of yet another type of dopant in a manner similar to that described for silver halide grains.

A particularly preferred method for preparing emulsions of photosensitive silver halide and organic silver salts for coating photoaddressable and thermally developable materials from a solvent medium according to the present invention is described in US Pat. No. 3,389,049. Although disclosed, Research Disclosure, June 1978, item 17
Other methods may also be used for emulsion production, such as those described in US-A-3700458. Another particularly preferred method for preparing emulsions of photosensitive silver halide and organic silver salts for coating photoaddressable and thermally developable materials from aqueous media according to the present invention is disclosed in WO 97/48014. It provides (i) a support, (ii) a substantially light-insensitive organic silver salt, a light-sensitive silver halide in catalytic relationship with a substantially light-insensitive organic silver salt, a substantially light-insensitive A method for producing a photothermographic recording material comprising the step of coating a support with a photoaddressable and thermally developable material comprising a reducing agent and a binder in a thermally operative relationship with an organic silver salt of
Wherein the photosensitive silver halide is formed by reacting an aqueous emulsion of particles of a substantially light-insensitive organic silver salt with at least one onium salt having a halide or polyhalide anion and is photoaddressable. A process is disclosed wherein the thermally developable material is coated from an aqueous dispersion medium.

Organic reducing agents suitable for the reduction of substantially light-insensitive organic silver salts in photoaddressable thermosensitive materials contain at least one active halogen atom linked to O, N or C. Organic compounds such as mono-, bis-, tris- or tetrakis-phenol,
Hydroxy-monoethers such as mono- or bis-naphthol, di- or polyhydroxy-naphthalene, di- or polyhydroxybenzene, alkoxynaphthol (for example 4-methoxy-1-naphthol as described in US-A 309441); pyrazolidine -3-one type reducing agent (for example, PHENIDONE ™), pyrazoline-
5-one, indane-1,3-dione derivative, hydroxytetronic acid, hydroxytetronimide, 3-pyrazoline, pyrazolone, reducing sugar, aminophenol (e.g., METOL (TM)), p-phenylenediamine, e.g., U.S. Pat. Hydroxylamine derivatives, reductones (eg, ascorbic acid), hydroxamic acids, hydrazine derivatives, amidoximes, n-hydroxyureas, and the like (US-A307).
4809, US-A 3080254, US-A 30
94417 and US-A 3887378).

Polyphenols such as bisphenol used in 3M Dry Silver® material, Kodak Daco
Photothermographic recording materials with photoaddressable and thermally developable materials based on photosensitive silver halide / organic silver salt / reducing agent, and sulfonamidophenols as used in matic® Especially preferred for During the thermal development step, the reducing agent must be present in such a way that it can diffuse into the light-sensitive silver halide and, if present, the substantially light-insensitive organic silver salt grains so that their reduction can take place.

The above reducing agents, which are regarded as main reducing agents, may be used in combination with so-called auxiliary reducing agents. The auxiliary reducing agent which may be used in combination with the main reducing agent is US-A
Sulfonyl hydrazide reducing agents as disclosed in US Pat. No. 5,647,838, trityl hydrazides and formyl-phenyl-hydrazides as disclosed in US Pat. No. 5,496,696 and organic reducing metal salts, for example US-A 34
Stannous stearate described in US Pat. Nos. 60946 and 3547648;

The film-forming binder for the photoaddressable thermosensitive material according to the invention may be coatable from a solvent or an aqueous dispersion medium. If the film-forming binder for the photoaddressable heat-sensitive material is coatable from the solvent dispersion medium according to the invention, all types of natural, modified natural or modified organic silver salts can be homogeneously dispersed. Synthetic resins or mixtures of such resins may be used: for example polymers derived from α, β-ethylenically unsaturated compounds, for example polyvinyl chloride, post-chlorinated polyvinyl chloride, copolymers of vinyl chloride and vinylidene chloride, chlorides Copolymers of vinyl and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, polyvinyl acetal, preferably polyvinyl, made from polyvinyl alcohol as a starting material in which only some of the vinyl alcohol units may react repeatedly with the aldehyde Butyral,
Copolymers of acrylonitrile and acrylamide, polyacrylates, polymethacrylates, polystyrene and polyethylene or mixtures thereof.
A particularly preferred polyvinyl butyral containing a small amount of vinyl alcohol units is BUTVAR® B
Under MON 76 and BUTVAR® B79
Sold by SANTO USA, provides good adhesion to paper and properly primed polyester supports.

The film-forming binders for the photoaddressable heat-sensitive developable materials coatable from the aqueous dispersion media according to the invention are transparent or translucent, aqueous dispersions of all kinds in which the organic silver salts can be homogeneously dispersed. It may be a soluble or water-soluble, natural, modified natural or synthetic resin or a mixture of such resins, for example, proteins such as gelatin and gelatin derivatives (eg phthaloyl gelatin), cellulose derivatives such as carboxymethyl cellulose, dextran,
Starch ethers, polysaccharides such as galactomannan, polyvinyl alcohol, polyvinylpyrrolidone, acrylamide polymers, homo- or copolymerized acrylic or methacrylic acids, latexes of water-dispersible polymers with or without hydrophilic groups, or the like. It is a mixture. Polymers having hydrophilic functionality for forming aqueous polymer dispersions (latex) are disclosed in US-A
No. 5006451, but acts therein to form a barrier layer that prevents unwanted diffusion of vanadium pentoxide present as an antistatic agent.

The weight ratio of the binder to the organic silver salt is 0.1.
The thickness is preferably in the range of 2 to 6, while the thickness of the photoaddressable and thermally developable material is preferably in the range of 5 to 50 μm.

The above binders or mixtures thereof improve the kinetics of the redox reaction at elevated temperatures, using "heat solvents".
olvents, thermal solvents, thermosolvents) or in combination with a wax. In the present invention, the term "thermal solvent" is in a solid state in a recording layer at a temperature of 50 ° C. or less, but is in a solid state of 60 ° C. At least one redox reactant at temperature (eg a reducing agent for organic silver salts)
Means a non-hydrolysable organic material that becomes a plasticizer for the heated layer and / or the recording layer in a liquid solvent. Useful for that purpose are US-A 3347
675 is a polyethylene glycol having an average molecular weight in the range of 1500 to 20,000 described in US Pat. Further, compounds such as urea, methylsulfonamide and ethylene carbonate which are thermal solvents described in US-A 3,667,959, and thermal solvents are described in Research Disclosure, December 1976, (item 15027) pp. 26-28. Tetrahydro-thiophene-1,1
-Compounds such as dioxide, methyl anisate and 1,10-decanediol. Still other examples of thermal solvents are described in US-A 3,438,776 and 4,740,446.
And published EP-A 0 196 615 and 0122
512 and DE-A 33 39 810.

The photo-addressable heat-sensitive material containing the substantially light-insensitive organic silver salt and the light-sensitive silver halide crystal may contain various other compounds, either on the material itself or on the processing of the material. It plays an important role later, such as during finishing or preserving steps.

These compounds include "toning agents", stabilizers and antifoggants, surfactants (especially for coating photoaddressable thermosensitive materials from aqueous media), antihalation dyes and other additives. Agent (EP-A 08445)
14 free fatty acids, antistatic agents, surfactants, etc.).

The support used for the photoaddressable thermosensitive material, the function and composition of the protective and antistatic layers, the coating of the various layers of the photothermographic recording material are disclosed in the same EP-A 0 844 514. I have.

The above description includes all the materials of the method for producing the photosensitive material of the present invention. This means that on the support and on one or both sides thereof the formulas (I) and / or (I
It can be summarized as a method for producing a light-sensitive material comprising at least one silver halide emulsion layer containing silver halide grains, wherein precipitation takes place in the presence of an organic hole-trapping dopant according to I). The precipitation must be carried out in the presence of an oxidizing agent, preferably p-toluenethiosulfonic acid, under the well-defined conditions described above.

[0083]

The present invention will now be described by the following examples, which should not be construed as limiting the invention thereto.

The following examples will clearly show the advantages that can be achieved with the method described in the present invention.

The following solutions were prepared for the preparation of the core-shell emulsion used in the following examples: Solution (1) containing 500 grams of silver nitrate in one liter of deionized water; Solution (2a ): 231.6 in 1 liter of deionized water.
Solution (2b): 349.9 in 1 liter of deionized water
Solution (3): containing 75 grams of inert gelatin in 1.5 liter of deionized water; Solution (4): 0.15 grams of 1 liter of deionized water. Contains sodium formiate.

Example 1 Production of Emulsion (a) Nucleation Step After raising the temperature of the solution (3) to 50 ° C., the pAg was adjusted to 7.4 with a 2.94 mol silver nitrate solution, and the pH was adjusted to 1 mol.
Adjusted to 2.8 with sulfuric acid solution. The solutions (1) and (2a) were then introduced into the solution (3) by using the double jet technique at a flow rate of 7.75 ml / min for 300 seconds while keeping the pAg constant at 7.4.

(B) Growth Step-First Step Then double jet precipitation was continued by introducing solutions (1) and (2a) into the above-mentioned precipitate maintained at 50 ° C. for 2888 seconds. The flow rate was then increased linearly from 7.75 ml / min at the start to 60 ml / min at the end of the precipitation, while maintaining the pAg at 7.4 throughout.

The emulsion was then ultrafiltered on a selectively permeable membrane for salts and water, while maintaining the same pAg of 7.4. After filtration, the emulsion was pulverized and stored for a shorter time. Gelatin is then added to bring the emulsion to a gelatin to silver ratio of 0.5 (silver is expressed as silver nitrate), and then as a preferred biocide for short stirring and storage to obtain good gelatin dispersion. A small addition of the phenol solution was made.

The emulsion thus prepared was 0.37 μm.
It contained monodisperse cubic particles having an average volume diameter of m. After adding 500 ml of deionized water to 650 grams of emulsion, the amount of silver nitrate was 85 grams per kg of emulsion. After bringing the temperature to 50 ° C., the pAg was adjusted to 3.6 by using a concentrated silver nitrate solution,
H was adjusted to 4.8 with 0.4 mol sodium hydroxide solution. Then 150 ml of 4.76 × 10 ⁻³ mol
A solution of sodium p-toluenethiosulfonate in silver nitrate 1
It was added per mol.

(C) Propagation Step-Second Step In this precipitation step, a triple jet method was performed to bring the thickness of the shell as close as possible to 50 nm and thus the total average volume particle thickness to 0.42 μm. Three solutions (1),
(2a) and (4) were co-injected into the core emulsion diluted with silver nitrate solution (1) to have a constant flow rate of 30 ml / min for 316 seconds while adjusting the pAg to 3.6.
Solution (4) was added at a flow rate of 10 ml / min for only 300 seconds (at the same start), which was kept constant during this precipitation step.

After cooling the emulsion to 40 ° C., the weight ratio of gelatin to silver nitrate was adjusted to 0.5 by adding an inert gelatin of the same type. The resulting emulsion contained 115 grams of silver nitrate per kilogram.

(D) Chemical sensitization The emulsion was then redispersed and diluted with deionized water to give pAg and
And pH to 7.16 and 5.5 respectively at a temperature of 60 ° C.
After adjustment, the following compound (per 35 grams of silver nitrate)
Added:-2.8 ml of diluted surfactant solution and 3.5
4.76 × 10 ml ^-3mol p-toluenethios
Sulfonic acid solutions (13 minutes after the addition of these solutions
Solution was added continuously);-0.84 ml of 8x10^-5mol sodium thiosulfate
Solution; 1.75 ml of 1.456 × 10^-3mol / l
AuCl₄・ 4H₂O and 1.58 × 10²mol / l
 NH₄A solution containing the CNS;-2.10 ml of 0.396 mol sodium sulfite
solution. Chemical sensitization until optimal sensitivity is achieved
Was.

Coating Method After cooling to 40 ° C., the ripened emulsion was adjusted to a weight ratio of gelatin to silver nitrate of 1.0. A well-defined amount of the sensitizing triazaindolizine derivative and some wetting agents were then added prior to coating the emulsion on a polyethylene terephthalate support. The amount of silver nitrate is 2.0
g / m ² .

Exposure and Processing The coated emulsion was then exposed for ^10-2 seconds through a step wedge (constant = 0.1) with a xenon lamp. After developing for 1 minute in a G150 bath, a 1 minute fixing step in a G333 bath (which was diluted with 4 parts deionized water to 1 part of G333) and a 1 minute wash in deionized water. The process was performed. All processing steps were performed at room temperature. G130 and G333 are trade names from AGFA-GEVAERT NV. The density achieved after processing was measured and used as a function of the light dose to determine the following parameters: fog level D _min , maximum density D _max , "Chemical Sens." Gives information about whether or not it is felt (+/-); the "Doped" column indicates when the emulsion is doped, thereby indicating that it is a compound of the invention, while the "Dopant amount" The column gives the amount of said dopant (ppm), expressed as the amount of dopant per mol of silver nitrate of the emulsion; the amounts given are the amounts added during the grain precipitation step;-sensitivity S _{0.1> fog} is 0.1 above fog level
Of light (log (I
t) expressed as units), the sensitivity S _{0.5> fog} is 0.5 above the fog level
Of light (log (I
t) expressed as units); S _{0.1> fog}
And a sensitivity value of S _{0.5> fog} means that a decrease of 0.3 is a two-fold increase in sensitivity.

[0095]

[Table 1]

The results summarized in Table 1 clearly demonstrate that AgCl emulsions doped with the compounds according to formula (I) according to the invention give an increase in sensitivity and covering power. It is chemically unsensitized and sensitized AgX
Found for both emulsions.

Example 2 For this experiment, only the AgBr emulsion was used in place of the AgCl emulsion of the previous example. Exactly the same methods and doping methods were applied for AgCl emulsions for the preparation and evaluation of pure AgBr emulsions having the same dimensions. In this case, instead of the solution (2a), the solution (2
b) is used with solution (1).

Triple jet precipitation was performed at a flow rate of 20 ml / min of solution (1) for 450 seconds while maintaining pAg at 3.6 for shell formation in the second step of the growth step. Only solution (4) was added at a flow rate of 8 ml / min at the same time and added for 375 seconds.

The resulting emulsion contained 14 per kilogram of emulsion.
It contained 0 grams of silver nitrate. The sensitometric results for the AgBr emulsion are summarized in Table 2, with the table headings having the same meaning as in Table 1.

[0100]

[Table 2]

Table 2 as shown for AgCl
The results in clearly demonstrate that the use of the compounds according to the invention as organic hole-trapping dopants in AgBr emulsions causes a considerable increase in sensitivity.

Example 3 Preparation of Emulsion Emulsions made in the same manner as described in steps (a) to (c) of Example 1 yield monodispersed cubic grains having an average volume diameter of 0.42 μm. Contained. 395 g of this emulsion was added to 606 ml of deionized water to bring the amount of silver nitrate to 50 g of Ag / kg of emulsion. 50 ℃
Was adjusted to 7.14 by using a concentrated silver nitrate solution. The emulsion was further redispersed and spectrally sensitized with a green light absorption sensitizer (with or without tetraazaindene as a stabilizer) at 38 ° C.
PAg and pH equal to 7.14 and 4.8 respectively
For 30 minutes. Then emulsion was coated with some wetting agent polyethylene terephthalate support in an amount of 1.5 g / m ^2.

The exposed and processed samples were subjected to a step optical wedge (Edgerton constant = 0.15).
It exposed with and through interference filter V405 and ^10-2 seconds xenon lamp through a cut-off filter L477. Exposed photographic material (James, Vanselow an
d Quirk in Phot. Sci. Technol., 19B (1953) p. 170) After developing in a methol-ascorbic acid bath for 8 minutes, a room temperature G333 bath (4 parts per part of G333). (Diluted with deionized water) for 1 minute and a 1 minute washing step with deionized water.
G333 is a trademarked product from AGFA-GEVAERT.

The results described in Table 3 describe the following parameters. -D _min is the fog level (displayed with an accuracy of 0.01) _{;-D max} is the maximum density (displayed with an accuracy of 0.01);-Sens (0.2> fog) is above the fog level Means Sensitivity in log (It) units realized at a concentration of 0.2; Sens (80% D _max ) means Sensitivity in log (It) units realized at 80% of maximum density.

Table 3 summarizes the sensitometric results of 0.42 μm (1 ppm formate-doped) AgBr cubic particles spectrally sensitized with a green light absorption sensitizer: monomer form (20% SGSC = Specific grain surface coverage; aggregated form (80% SGSC); aggregated form (80% SGSC) (in the presence of tetraazaindene (= TAI) as stabilizer).

[0106]

[Table 3]

From the results given in Table 3, the doping of the emulsions with the organic hole-trapping agents according to the formula (I) according to the invention gives a very strong increase in the sensitivity by irradiation with light absorbed by the silver halide itself. You can conclude that you give. This increase is almost independent of the structure of the spectral sensitizer present on the grain surface. Irradiation with light that is particularly absorbed by the spectral sensitizer gives a greater increase in sensitivity than said increase. The effect realized with the hole trapping agent of the present invention is greatest for emulsions containing the spectral sensitizer in aggregated form.

As can be seen from the table, it is possible to achieve a further increase in sensitivity if a photographic stabilizer such as tetraazaindene is used with a spectral sensitizer when present on the grain surface in agglomerated form. it can.

Example 4 The following solutions were prepared for the preparation of a core-shell emulsion containing 100 ppm of Rongalite used in this example (see compound II.1 of the above-mentioned embodiment of the invention): (1) containing 500 grams of silver nitrate in 1 liter of deionized water; solution (2) 349. in 1 liter of deionized water.
Solution (3) contains 50 grams of inert gelatin in one liter of deionized water; Solution (4) contains 0.37 in one liter of deionized water.
Contains 2 grams of Rongalite.

Emulsion Production (a) Nucleation Step After raising the temperature of the solution (3) to 63 ° C., pAg was increased to 6.9 with the solution (2) and 2.8 with a 0.3 mol sulfuric acid solution. Was adjusted. Solutions (1) and (2) were then introduced by using the double jet technique into solution (3) at a flow rate of 0.87 ml / min for 300 seconds while keeping the pAg constant at 6.9.

(B) Neutralization Step To adjust the pAg to a value of 7.8, add 10 parts of solution (2).
Introduced at a flow rate of ml / min for 2 seconds.

(C) First growth step The solution (1) was placed in a reaction vessel maintained at 63 ° C. for 8414 seconds.
And double jet precipitation was continued by introducing (2). Then from 0.87 ml / min at the start to 13.3 at the end of the precipitation, while maintaining the pAg at 7.8 all the time.
The flow rate was increased primarily to 3 ml / min.

The emulsion was ultrafiltered over a selectively permeable membrane for salt and water, while maintaining the same pAg of 7.8. After filtration, the emulsion was pulverized and stored for a shorter time.
Gelatin was then added to give a gelatin to silver ratio of 0.5 (silver is expressed as silver nitrate). After this addition, a short period of stirring to obtain a homogeneous gelatin dispersion and a small addition of an aqueous solution of phenol acting as a biocide were performed.

The emulsion thus prepared was 0.40 μm.
It contained monodispersed cubic silver bromide particles having an average volume diameter of m. After adding 650 ml of deionized water to 650 grams of the emulsion, the amount of silver nitrate was reduced to 10 per kg of emulsion.
It was 0 grams. After bringing the temperature to 50 ° C., the pAg was adjusted to 4.15 by using a concentrated silver nitrate solution and the pH was adjusted to 4.8 with a 0.3 mol sulfuric acid solution. Next, 25 ml of a 4.76 mmol sodium p-toluenethiosulfonate solution was added per 1 mol of silver nitrate. The core emulsion thus obtained was divided into four equal parts (designated A, B, C and D).

(D) Second Growth Step In this precipitation step, the triple jet method was used to bring the shell thickness as close as possible to 50 nm, thus making the total average volume particle thickness 0.45 μm. Three solutions (1),
(2) and (4) were converted to pAg of 4.15 and 6.65.
The silver nitrate solution (1) was adjusted to 4
Core emulsions B and D diluted together to have a constant flow rate of 20 ml / min for 50 seconds were co-injected. Solution (4) was applied to the parts B and D at a constant flow rate of 8 ml / min.
Added simultaneously for 5 seconds. The same was done for parts A and C, except for the addition of Rongalite solution (4).

After cooling emulsion parts A, B, C and D to 40 ° C., the weight ratio of gelatin to silver nitrate was adjusted to 0.5 by adding an inert gelatin of the same type. The resulting emulsion contained 124 grams of silver nitrate per kilogram.

[0117] After cooling the coating method 40 ° C., the emulsion part A and D, it was adjusted to a weight ratio of gelatin to silver nitrate of 1.27 by adding an additional amount of gelatin. Then, a tetraazaindolizine wetting and curing agent as a stabilizer was added to emulsion part A.
-D was added before coating on the polyethylene terephthalate support. The amount of silver nitrate was 1.23, 1.45, 1.5 / m ² for materials A, B, C and D, respectively.
1 and 1.35 grams.

Exposure and Processing The coated material AD was passed through a step optical wedge (the sample was passed through a step optical wedge (Edgerton constant = 0.15)).
0 through ^-2 seconds xenon lamp is exposed in) and through an interference filter V405 used for the exposure of the intrinsic optical absorption region was exposed ^10-2 seconds. Exposed photographic material (James, Vanselowand Quirk in Ph.
Developed in a methol-ascorbic acid bath for 8 minutes (as defined in ot. Sci. Technol., 19B (1953) p. 170) followed by a room temperature G333 bath (4 parts degassing per part of G333). (Diluted with ionic water) for 1 minute and a 1 minute wash with deionized water. G33
3 is a trademark product from AGFA-GEVAERT.

All processing steps were performed at room temperature. G3
33 (R) is a trademark from Agfa-Gevaert NV. The density achieved after processing as a function of the light dose was measured and used to determine the following parameters: fog level D _min , maximum density D _max , “Sens. 1” was 0.2% above fog Give information about the sensitivity measured at the density, "Sens. 2" gives information about the sensitivity measured at 80% of the maximum density. (Both sensitivities are required to obtain the desired density (log
It is measured as the amount of light (expressed in units of (exposure)): a reduction of 0.3 therefore corresponds to a two-fold increase in sensitivity. )

The results summarized in Table 4 below show that the silver bromide emulsion doped with Rongalit compound II.1 according to formula (II) of the present invention has a high sensitivity even when no chemical sensitizer is added. Very clearly proves to give an increase. Rongalit compounds as organic hole trapping agents
Emulsion doped according to the invention in II.1 (Emulsion B of the invention)
And D) is 0.2% above the fog
The sensitivity is higher than Comparative Emulsions A and C, even if no chemical ripening agent is added to the emulsion as can be calculated from the sensitivity measured at a concentration of. The low sensitivity for Emulsion B at a concentration of 0.8 × D _max is clearly due to the low pAg values maintained during shell precipitation.

[0121]

[Table 4]

[0122] After adjusting the pAg and pH at a temperature of chemical sensitization 40 ° C., respectively 7.32 and 5.5, the following compounds were added (per 35 g of silver nitrate): - 1.75 ml diluted interface Activator solution and 3.
5 ml of 4.76 mmol sodium p-toluenethiosulfonate solution (the following solution was added continuously 13 minutes after addition of these solutions):-0.84 ml of 8 x ^10-5 mol sodium thiosulphate solution; - 1.75 ml of ^{1.456 × 10 -3 mol / l HAuCl} 4 · 4H 2 O and 1.58 × ¹⁰ -2 mol of
/ L NH ₄ CNS solution;-2.10 ml 7.93 μmol sodium sulfite solution.

Chemical sensitization is performed until optimum sensitivity is achieved.
Performed at 0 ° C. The data provided in Table 4 for materials A ', B', C 'and D' coated with chemically ripened emulsions AD are summarized in Table 5.

The exposure was carried out using a xenon lamp AV405 used for exposure in the intrinsic optical absorption region.
Performed within 0.06 seconds through a step wedge having a constant of 15 and a density of D = 1. Develop at 23 ° C for 2
After running in the G150® developer solution (dilution: 1 + 5) for 1 minute, a fixing step in a G335® bath for 2 minutes and a washing step in deionized water at 23 ° C. for 2 minutes were performed. G150 (registered trademark) and G335 (registered trademark)
Are trade names from Agfa-Gevaert NV.

[0125]

[Table 5]

As can be concluded from the results obtained from Table 5, the chemically ripened emulsions A'-D 'coated as corresponding materials have an increased maximum density compared to the unripened emulsions from Table 4, Emulsions doped with organic hole trapping agents as Rongalits show clearly increased sensitivity at both low and high concentrations. A sensitivity increase of up to two-fold is actually measured, for example, when the materials C 'and D' (both with pAg in shell precipitation) are compared to each other.

Having described preferred examples of the invention in detail,
It will be apparent to those skilled in the art that many modifications may be made without departing from the scope of the invention as set forth in the claims.

Continuing on the front page (72) Inventor Mona Treg-France, France-75012 Paris, Rue, de, la, lancet 15 (72) Inventor Jacqueline Veroni-Cofour Effart-France, 91120 Roselle, Boulevard, de , Pareso 14 (72) Inventor In Lumito F R-91190 GI F / Yvette, Ryu, de, Fondo, Fanette 6

Claims (4)

[Claims] 1. A photosensitive material comprising a silver halide emulsion having silver halide grains containing an organic hole trapping dopant. 2. The photosensitive material according to claim 1, wherein the organic hole trapping dopant is represented by the following formula (I): R-COOM (I) wherein R is hydrogen, a substituted or unsubstituted alkyl group, Or an unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a heteroaryl group, and M is hydrogen or a metal or organic group capable of forming a salt. 3. The photosensitive material according to claim 1, wherein the organic hole trapping dopant is represented by the following formula (II): Wherein X and Y are independently selected from O, S, Se;
m is 1, n is 1 or 2, R1 and R2 each independently represent hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl or aralkyl group or a substituted or unsubstituted heteroaryl group, R1 and R2 may be the same or different, and may form a ring. E is a group linked to the carbon atom by a heteroatom having at least one free electron pair, and M ⁺ is a proton or an organic or inorganic counterion. 4. A photo-addressable thermographic material comprising a substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal relation therewith, and a binder. The photosensitive material according to any one of the above.