JPH02244043A - Thermally developable photosensitive material - Google Patents

Abstract

PURPOSE:To prevent desensitization during storage at high humidity by forming a silver halide emulsion layer contg. photosensitive silver halide chemically sensitized in the presence of inrog. sulfur. CONSTITUTION:When a thermally developable photosensitive material having a binder, photosensitive silver halide and a reducing agent on the support is produced, at least one silver halide emulsion layer contg. photosensitive silver halide particles chemically sensitized in the presence of inorg. sulfur is formed. The inorg. sulfur means sulfur as a simple substance not forming a compd. with other element and does not include a sulfur-contg. compd., a sulfur-contg. heterocyclic compd., etc., known as photographic additives. Desensitization by the reducing agent is prevented even during storage at high humidity and high max. density and low min. density are obtd.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a heat-developable photosensitive material, and in particular, a heat-developable silver halide photographic material that has improved storage stability and provides a high maximum density and a low minimum density. Regarding materials.

[Prior Art] A photosensitive material that can be developed and a visible image obtained simply by heating the exposed silver halide photosensitive j#4Fl without bath treatment is developed by thermal phenomenon halogenation. It is well known as a silver photographic material.

A thermal MS silver halide photographic material (hereinafter referred to as a "thermal development material") contains a light-sensitive silver halide emulsion, a binder and a reducing agent on a support, and if necessary, a non-light-sensitive organic silver Contains salt.

When the heat-developable material is a heat-developable silver halide photographic material used in color photography (hereinafter referred to as a "thermally developable color-sensitive material"), if necessary, a silver halide emulsion may be developed. Accordingly, dye-donating substances that form or release dyes are used. However, other dye-providing substances are not necessarily required for heat-developable color sensitive materials in which the reducing agent itself is a dye-providing substance.

In heat-developable color photosensitive materials, the dyes formed or released as a result of heat development are imagewise formed by overlaying the photosensitive material and a dye-receiving material having a dye-receiving Ia layer on a support. Diffusion transfer is also carried out, and this method is preferably used because a clear color image can be obtained.

However, in the heat-developable material as described above, a reducing agent is contained in the photosensitive layer including the silver halide emulsion layer or in a layer adjacent thereto. (including precursors),
They have various problems compared to silver halide photosensitive materials for bath processing, but among them, undesirable desensitization effects on silver halide tend to occur during storage of photosensitive materials, especially in high humidity conditions. It had the disadvantage of significant desensitization when stored for a long period of time.

Conventionally, various attempts have been made to prevent fogging or desensitization during storage of heat-transferable materials. For example, JP-A-61-112140 discloses a technique using silver halide in which the surface of the silver halide grains is a layer containing a high iodine content. Also, special RrIA61-3894
No. 2 discloses that a poorly soluble silver salt is formed on the surface of a substantially non-photosensitive silver salt such as silver chloride, for example, 1-phenyl-5
- A technique has been disclosed in which silver salt particles containing adsorbed compounds such as mercaptotetrazole are included.

However, even with these techniques, sufficient effects cannot be obtained against sensitivity loss during storage, and in particular, they are insufficient to prevent desensitization caused by reducing agents when stored under high humidity conditions. there were.

In order to obtain a sufficient effect of preventing improvement in storage stability using the above two techniques, it is necessary to significantly increase the iodine content of the surface of the photosensitive silver halide grains, or to add L! i. Silver salt particles that have adsorbed soluble compounds must be used extensively, resulting in poor developability and increased sensitivity to the development temperature and the ambient temperature of the heat developing machine. A problem arises in that stability tends to decrease.

JP-A-61-193143 discloses a method in which a sensitizing dye is present during the formation of silver halide grains, and a heat developable material using silver halide grains obtained by this method can be heated at 40℃.

It is stated that sensitivity fluctuations are reduced even when stored at a relative humidity of 70%. However, a problem arises in that the sensitizing dye added during the silver halide grain formation stage is not completely removed even in the desalting step, resulting in spectral sensitization due to the sensitizing dye.

In other words, heat-developable materials are often exposed and heat-developed using a device in which an exposure system and a heat developing machine are combined into one device; Since exposure is carried out in an exposure system which is in a relatively high temperature state due to the dissipated residual heat and whose temperature fluctuates easily, the temperature dependence of the photographic performance of the heat developable material during exposure becomes particularly important.

In general, the exposure and temperature dependence of silver halide photographic materials is largely dependent on the type of sensitizing dye used, so the types of sensitizing dyes are largely limited in order to fully satisfy the temperature dependence. Naturally, this method has the drawback that the sensitizing dyes that can be used in forming silver halide grains are greatly limited.

[Problems to be Solved by the Invention] The first object of the present invention is to provide a heat-sensitized material that is prevented from desensitizing by a reducing agent during storage, and particularly when stored under high humidity conditions. An object of the present invention is to provide a heat-sensitized material that has improved desensitization when subjected to heat transfer.

A second object of the present invention is to provide a heat developable material that provides a high maximum density and a low minimum density.

[Means for Solving the Problems] The object of the present invention is to provide a heat-developable photosensitive material having a binder photosensitive silver halide and a reducing agent on a support, which is chemically sensitized in the presence of inorganic sulfur. This is achieved by a heat-developable photosensitive material characterized by having at least one silver halide emulsion layer containing photosensitive silver halide grains.

Hereinafter, the present invention will be further explained in detail.

In the present invention, chemical sensitization must be carried out in the presence of inorganic sulfur, but the term "unfiltered sulfur" used in the present invention refers to so-called simple sulfur that does not form compounds with other elements. means. Therefore, in the art, sulfur-containing compounds known as photographic additives, such as sulfides, sulfur R (or salts thereof), sub-V1
71 acid (or its!), thiosulfuric acid (or its salt),
Sulfonic acids (or salts thereof), thioether compounds, thiourea compounds, mercapto compounds, sulfur-containing multicyclic compounds, and the like are not included in the inorganic sulfur compounds in the present invention.

It is known that the simple substance sulfur used as inorganic sulfur in the present invention has several allotropes, and any of these allotropes may be used.

Among the above allotropes, the one that is stable at room temperature is α-sulfur, which belongs to the orthorhombic system.
- Preference is given to using sulfur.

When adding the inorganic sulfur according to the present invention, it may be added as a solid, but it is preferably added as a solution. I-free sulfur is insoluble in water, but is known to be soluble in carbon disulfide, sulfur chloride, benzene, diethyl ether, ethanol, etc., and it is preferable to dissolve it in these solvents before adding it. However, among these solvents for ma sulfur, ethanol is particularly preferably used in terms of absorbency and photographic effects.

The rate of addition of inorganic sulfur can be arbitrarily selected depending on the type of silver halide emulsion to be applied and the size of the expected effect, but it is
~101111 is preferred, more preferably 1X 10
'IQ ~5mg.

Regarding the timing of adding inorganic sulfur, it can be added at any step as long as the silver halide grains are chemically sensitized in the presence of inorganic sulfur. Specifically, before the formation of silver halide grains, during the formation of silver halide grains, from the end of silver halide grain formation to before the desalting step,
It may be carried out at any time selected from after the desalting step and before the start of chemical sensitization, at the start of chemical sensitization, and during chemical sensitization. Preferably from the end of silver halide grain formation to before the desalting step,
It is added at any time selected from after the desalting step and before the start of chemical sensitization, at the start of chemical sensitization, and during chemical sensitization.

More preferably, in order to greatly obtain the effects of particularly high maximum density and low fog without decreasing sensitivity, it is preferable that the treatment be carried out after the desalting step and before the start of chemical sensitization, at the start of chemical sensitization, and during chemical sensitization. Any time selected is preferred, most preferably at the start of chemical sensitization.

In the present invention, uncoated sulfur can be used alone as a sensitizer, but it is preferable to use a chemical sensitizer, such as a chalcogen sensitizer, in combination during chemical sensitization. Chalcogen sensitizer is a general term for sulfur sensitizers, selenium sensitizers, and tellurium sensitizers, and for photography, sulfur sensitizers and selenium sensitizers are preferred. Known sulfur sensitizers can be used, such as thiosulfate, allylthiocarbazide, thiourea, allyl isothiocyanate, cystine,
Examples include p-toluenethiosulfonate and D-danine. Others, U.S. Patent No. 1,574,944, U.S. Patent No. 2.4
No. 10.689, No. 2.278.947, No. 2,72
No. 8,668, No. 3,501,313, No. 3,656
, No. 955, West German Publication (OL S') 1,42
No. 2,869, JP-A-56-24937, JP-A No. 55-4
Sulfur sensitizers described in Publication No. 5016 and the like can also be used. The amount of sulfur sensitizer added varies over a considerable range depending on various conditions such as pH, temperature, and size of silver halide grains, but as a guideline, it is from 10-7 to 10- About 1 mol is preferable.

In addition, examples of selenium sensitizers include aliphatic isoselenocyanates such as allyl isoselenocyanate, selenoureas, selenoketones, selenoamides, selenocarboxylic acid salts and esters, selenophosphates, and diethylselenide. , diethylselenide, and other selenides can be used, and specific examples thereof include U.S. Pat. No. 1.574944, U.S. Pat.
623,499, etc. Furthermore, reduction sensitization can also be used together. The reducing agent is not particularly limited, but includes known stannous chloride, thiourea dioxide, hydrazine, polyamine, and the like. Further, noble metal compounds such as platinum compounds and palladium compounds can be used in combination.

In the present invention, it is preferable to perform chemical sensitization using inorganic sulfur and a sulfur sensitizer in combination, or to perform chemical sensitization using a combination of inorganic sulfur, a sulfur sensitizer, and a gold compound.

In the present invention, the conditions for chemical sensitization to be carried out can be arbitrarily selected depending on the silver halide grains used and the expected photographic properties, but as a rough guide, the temperature is 35°C.
°C to 70 °C, pH is 5.0 to 1.5, and oAa is 6.0 to 8.5. The chemical sensitization time is usually determined by checking the photographic characteristics for each time step under the chemical sensitization conditions in advance, and selecting the most favorable photorealistic characteristics (for example, low fog, high sensitivity, high contrast, etc.). Although it is set in hours, manufacturing stability and work efficiency in the process are often taken into consideration, and a rough guideline is several tens of minutes to several hours.

Further, in the present invention, it is preferable to carry out chemical sensitization in the presence of a nitrogen-containing heterocyclic compound, and more preferably to carry out chemical sensitization in the presence of a mercapto compound.

Preferred examples of nitrogen-containing heterocyclic compounds such as this (M-
1) (M-3) (M-5) (M-7) CM-11) (M-12) (M-21) (M-23) (M-25) (M-15) (M-16 ) (M-17) (M-18) (M-27) (M-29) Shiyama (M-2) (M-4) (M-6) (M-8) (M-22> (M -24) (M-26) (M-28) (M-30) (M-311 (M-33) (M-35) (M-37) (M-39) (M-49) (M- 51) (M-53) (M-55) (M-32) (M-34) (M-3(+) (M-38) (M-40) (M-50) (M-52) ( M-54) (M-56) (M-47) (M-57) (M-59) (M-61) (M-63) (M-48) (M-58) (M-60) ( M-62) (M-64) S○, H During chemical sensitization, the above compound is preferably used in an amount of 0.001 to 10 mmol, more preferably 0.001 to 10 mmol per mol of silver halide.
It is used in a range of 0.01 to 5 mmol.

The light-sensitive silver halide emulsion according to the present invention can be spectrally sensitized to blue, green, red and near-infrared regions using known sensitizing dyes.

Typical spectral sensitizing dyes that can be used in the present invention include, for example, cyanine, merocyanine, complex (that is, trinuclear or tetranuclear) cyanine, holobola-cyanine, styryl, hemicyanine, oxonol, and the like.

The preferred loading of these sensitizing dyes is 1 x 10 per mole of photosensitive silver halide or silver halide forming component.
-6 mol to 1 mol. More preferably 1.1X10
-5 to I X 10-' mol.

The sensitizing dye may be added at any stage of the preparation of the silver halide emulsion. That is, it may be carried out at any time, such as when silver halide grains are formed, when soluble salts are removed, before the start of chemical sensitization, during chemical sensitization, or after the end of chemical sensitization.

The photosensitive silver halide used in the present invention includes, for example, silver bromide,
Any silver halide consisting of chlorine, bromine, or iodide, such as silver iodobromide, silver chloride, silver chlorobromide, silver chloroiodide, silver chloroiobromide, etc., may be used, but silver bromide, silver iodobromide, etc. Silver oxide and silver chloroiodobromide are preferred. Silver iodide in halogenated eyes is 0 to 15 mol%
is preferable, and 0 to 5 mol% is particularly preferable.

Furthermore, even if the crystal structure of silver halide grains is similar up to the inside, there are also grains with a layered structure with different inside and outside, and British patent No. 635.841 and US patent No. 3.62.
It may also be of a so-called conversion type as described in No. 2.318. Further, either a type in which a latent image is mainly formed on the surface or an internal latent image type in which a latent image is formed inside the particle may be used. As grains having a multilayer structure in which the halogen composition of the grain is different on the surface and inside, for example, core/shell type silver halide grains, grains in which the halogen composition changes stepwise or continuously are used.

In addition, its shape is cubic, spherical, octahedral, dodecahedron,
Even those with clear crystal habit such as 14-hedral and 24-hedral,
Even if it is not, it can be used. Examples of this type of silver halide include those described in JP-A-60-215948.

Also 1, for example, JP-A-58-111933, JP-A No. 58-1
No. 11934, No. 58-108526, Research Disclosure No. 22534, etc., it has two parallel crystal planes, and each of these crystal planes is different from other single crystals of this particle. It is also possible to use tabular silver halide grains having a larger area than the above grains and an aspect ratio, that is, a ratio of grain diameter to thickness of 5:1 or more.

The photosensitive silver halide grains used in the present invention may be coarse or fine, but the preferred grain size is about 0.05 μm to about 2 μm, more preferably about 2 μm. O, Oa μm to 0.5 μm. however,
In the present invention, "particle size" refers to the length of one side of a cube having the same volume. Although the particle size distribution is wide (polydisperse emulsion),
Although it may be narrow (a monodisperse emulsion), a monodisperse emulsion is preferable for the purpose of the present invention.

In particular, silver halide grains having a coefficient of variation in grain size distribution of 20% or less are preferred. Here, the coefficient of variation is defined as the average value of coefficient of variation (%) - 0 standard deviation of particle diameter x 100 particle diameter, and is a measure of monodispersity.

The photosensitive silver halide can be prepared by any method commonly used in the photographic field, such as a single jet method or a Chondral double jet method.

When forming these photosensitive silver halide grains, heavy metal ions such as gold, platinum, lead, cadmium, rhodium, and iridium can be present, but in particular, iridium ions are used because they do not reduce sensitivity during high-intensity exposure. preferred. Preferably used compounds that provide iridium ions include, for example, hexachloroiridium (II
I)F! lit! ! Or hexachloroiridium (
fV) Acid F [e.g. 2 1r Cff1s,
K31r Cff1s.

Li 3 1r Cff1s, Na31r
Cj! s.

(NH4)2 1r Cff1s,
Li 2 1r CQ 6 .

Examples include water-soluble iridium compounds such as Na21r Cff1s ]. These iridium compounds are added in an amount of 10-8 to 10-4 mol per mol of silver halide.

During the formation of silver halide grains, a silver halide solvent is used to control grain growth.
No. 574,628, No. 3,704,130, No. 4
．． No. 297.439, No. 4,276.374, etc.>
Thione compounds (for example, JP-A-53-144319, JP-A-53-82408, JP-A-55-77737, etc.)
, amine compounds (for example, JP-A-54-100717), etc. can be used. In addition to silver halide solvents, compounds that adsorb to the grain surface to control crystal habit, such as:
Cyanine-based sensitizing dyes, tetrazaindene-based compounds, mercapto compounds, and the like can be used during particle formation.

In the present invention, as another WA manufacturing method for silver halide grains, a photosensitive silver salt-forming component can be allowed to coexist with an organic silver salt to be described later, and photosensitive silver halide can be formed in a part of the organic silver salt.

As the reducing agent (and/or the reducing agent precursor that releases the reducing agent during heat development) used in the heat developable material of the present invention, those commonly used in the field of heat developable materials can be used. It is preferable to use a drug precursor from the viewpoint of storage stability.

Examples of reducing agents that can be used in the present invention include U.S. Pat. Nos. 3,531,286 and 3,761,27.
No. 0, No. 3,764,328, and RD (Research Disclosure) No. 1214
6, No. 15108, No. 15127, and JP-A-56-27132, U.S. Patent No. 3.342.
．． p-phenylenediamine-based and p-aminephenol-based developing agents, phos Foramide phenol type, sulfonamide aniline type developing agent, hydrazone type color developing agent and their precursors, or phenols, sulfonamide phenols, polyhydroxybenzenes, naphthols, hydroxybisnaphthyls and methylene naphthols , methylene bisphenols, ascorbic acid, 3-pyrazolidones, and pyrazolones can be used.

As a particularly preferable reducing agent, JP-A-56-146133
No. 62-227141 and (+1-N
, N-dialkylamino) phenylsulfamate represented by the following -setting [I].

General formula [I] In the formula, R1 and R2 represent an alkyl group having 1 to 30 carbon atoms (preferably 1 to 4) which may have a substituent, and R1 and R2 are ring-closed to form a heterocyclic ring. may be formed. R
3, R4, R5 and R6 each have a hydrogen atom, a halogen atom, a hydroxy group, an amino group, an alkoxy group, an acylamide group, a sulfonamide group, an alkylsulfonamide group, or a carbon atom number of 1 to 30 that may have a substituent ( Preferably represents an alkyl group of 1 to 4), R3 and R1 and R5 and R
2 may each be ring-closed to form a heterocycle. M represents a compound containing an alkali metal atom (Na, Li, etc.), an ammonium group, a nitrogen-containing organic base, or a quaternary nitrogen atom.

The nitrogen-containing organic base represented by M in the above-setting [I] is an organic compound containing a basic nitrogen atom capable of forming an inorganic salt and a salt, and particularly important aim groups include amine compounds. It will be done.

As chain amine compounds, primary amines, secondary amines, etc.
Typical examples of cyclic amine compounds include typical heterocyclic organic bases such as lysine, quinoline, piperidine, and imidazole. In addition, hydroxylamine, hydrazine,
Compounds such as amidine are also useful as chain amines. In addition, as salts of nitrogen-containing I bases, the above-mentioned non-II salts of organic bases (e.g., hydrochlorides, raate salts, nitrates, etc.)
is preferably used.

On the other hand, examples of the compound containing a quaternary nitrogen atom represented by M in the above-mentioned -setting [I] include salts or hydroxide compounds of nitrogen compounds having a tetravalent covalent bond.

Next, the preference of the reducing agent shown in the above-mentioned setting [I] (R-1
) (R-2) (R-3) (R-4) (R-7) (R-13) (R-9) (R-15) (R-10) (R-18) (R-11 ) (R-17) (R-12) (R-18) (R-19) (R-20) <R-28> (R-29) (R-30) (R~31) (R-24 ) (R-25) (R-26) (R-27) Further, in the present invention, a substance represented by the following -setting [I[] can also be used as a reducing agent.

- Installation [II] (Car)-NH8O2-DVe In the formula, Car is a reducing group that is oxidized and releases a dye upon reduction of silver halide and/or organic silver salt, and D
ye is a diffusible dye residue. Specific examples of the above-mentioned reducing dye-releasing compounds include, for example, JP-A-57-179840, JP-A-58-116537, and JP-A-59-6043.
4@, JP-A-59-65839, JP-A-59-710
No. 46, JP-A-59-87450, JP-A-59-88
No. 730, JP-A-59-123837, JP-A-59-
165054, JP-A-59-165055, and JP-A-62-203158.

Along with these reducing agents, a metal compound as disclosed in Japanese Patent Application No. 104645/1983 may be added for the purpose of obtaining a high image temperature.

Two or more types of the above-mentioned reducing agents may be used simultaneously.

The reducing agent used in the heat-developable color sensitive material of the present invention depends on the type of photosensitive silver halide used,
Although it can be arbitrarily selected depending on the type of silver salt and the type of other additives, it is usually preferable to use photosensitive silver halide 1.
It ranges from 0.01 to 100 mol, preferably from 0.1 to 10 mol.

Furthermore, the binder used in the heat development material of the present invention includes gelatin lJ1 such as polyvinyl butyral, polyvinyl acetate, ethyl cellulose, polymethyl methacrylate, cellulose acetate butyrate, polyvinyl alcohol, polyvinyl bi-Olidone, gelatin, and phthalated gelatin; There are synthetic or natural polymeric substances such as cellulose derivatives, proteins, starches, and gum arabic, and one or more of these can be used in combination.

The preferred amount of binder used is usually 0.59 to 50Q per 1f of support, more preferably 1g to zog.
It is.

In the heat developable material of the present invention, various organic silver salts can be used as necessary.

Examples of organic silver salts that can be used in the heat developable material of the present invention include JP-A-53-4921 and JP-A-49-52626.
No. 52-141222, No. 53-36224 and No. 53-37626, No. 52-141222,
Publications such as No. 53-36224 and No. 53-37610, and U.S. Patent Nos. 3.330.633 and 3.
．． Silver salts of long-chain aliphatic carboxylic acids and silver salts of carboxylic acids having heterocycles, such as lauric acid, as described in Patents No. 794.496 and No. 4.105.451, etc. Silver, silver myristate, silver balmitate, silver stearate, silver arachidonate, silver behenate, α-(1
-Phenyltetrazolethio) Silver aromatic carboxylates such as silver acetate, such as silver benzoate, silver phthalate, etc., Japanese Patent Publication No. 182, No. 45-12700, No. 45
-18416, No. 45-22185, JP-A-1983-
No. 137321, JP-A-58-118638, JP-A No. 58
There are silver salts of imino groups described in US Pat. No. 4,123,274 and No. 118639.

Other silver complex compounds having a stability constant of 4.5 to 10.0 as described in JP-A No. 52-31728, and imizolithion as described in U.S. Pat. No. 4,168,980. Silver salt etc. are used.

Among the above organic silver salts, imino group silver salts are preferred;
Silver salts of benzotriazole and its derivatives are more preferred. Particularly preferred are silver salts of benzotriazole, 5-methylbenzotriazole and its derivatives, sulfobenzotriazole and its derivatives, and N-alkylsulfamoylbenzotriazole and its derivatives.

The organic silver salts used in the present invention may be used alone or in combination of two or more. Alternatively, the silver salt may be prepared in a suitable binder and used as is without isolation.
The isolated product may be used after being dispersed in a binder by an appropriate means. As a means of dispersion, ball mill, sand mill 1. Examples include those using a colloid mill and a vibration mill, but the method is not limited thereto.

The amount of the organic silver salt used is generally preferably 0.01 to 500 moles, more preferably 0.1 to 100 moles, per mole of photosensitive silver halide. Roughly preferably 0
, 3 to 30 moles.

When the heat developable material of the present invention is a heat developable color sensitive material, it contains a dye-providing substance. Since the dye-donating substance is generally used together with the reducing agent, the dye-donating substance is selected depending on the reducing agent. Incidentally, when the reducing agent also serves as a dye-donating substance as expressed in the above-mentioned configuration [II], a dye-donating substance is not necessarily required in addition to the reducing agent.

As the dye-donating substance used in the present invention, for example, JP-A No. 6
2-44737, JP 62-129852, JP 62-169158, and non-diffusible dye forming couplers, such as U.S. Pat. No. 475.114.
The 0ico dye described in No. 1, or the azo dye used in the heat-developable dye bleaching method described in US IIl Special Edition No. 4.235.957, etc. can also be used as the dye-providing substance, but more preferably Diffusible dye-providing substances that form or release diffusible dyes may be used, and in particular compounds that form diffusible dyes upon coupling reaction are preferably used.

Diffusible dye-providing substances that can be used in the present invention will be explained below. The diffusible dye-donor substance may be one that participates in the reduction reaction of the photosensitive silver halide and/or the organic silver salt used as necessary, and can form or release a diffusible dye as a function of the reaction. Depending on their reaction mode, some dye-donors act in a positive function (i.e., those that form a negative dye image when using negative-working silver halide) and others act in a negative function. A positive-working dye-providing substance (!1) that forms a positive dye image when negative-working silver halide is used)
It can be classified into

As a negative dye-donating substance, for example, U.S. Pat.
No. 63,079, No. 4,439,513, JP-A-59
-60434, 59-65839, 5'l-7
No. 1046, No. 59-87450, No. 59-8873
No. 0, No. 859-123837, l8159-1243
No. 29, No. 59-165054, No. 59-16405
Examples include reducing dye-releasing compounds described in specifications such as No. 5.

Other negative dye-providing substances include, for example, U.S. Pat.
, No. 474,867, JP-A-59-12431, No. 5
No. 9-48165, No. 59-174834 @, No. 59
-776642, 59-159159, 59-
Examples include coupled dye-releasing compounds described in specifications such as No. 231040 N.

Another particularly preferred negative-tone dye-providing substance of the coupled dye-forming compound is one represented by the following general formula (a).

General formula (a) G o -(-J +-+B) In the formula, Cl11 can react with the oxidized form of the reducing agent (coupling reaction) to form a diffusible dye. a
J represents a divalent viscosity-containing group substituted at the active site of the coupler, and 8 represents a ballast group.

Here, the ballast group is a group that substantially prevents the dye-donating substance from diffusing during heat development processing, and includes groups (such as sulfo groups) that exhibit this effect depending on the nature of the molecule, and groups that exhibit this effect depending on the size of the molecule. ! ! (such as groups with a large number of carbon atoms), etc. The coupler residue represented by Cp has a molecular base of 70% to improve the diffusivity of the dye formed.
It is preferably 0 or less, more preferably 500 or less.

The ballast group is preferably a group having 8 or more carbon atoms, more preferably 12 or more carbon atoms, or a sulfo group, a group containing both is even more preferable, and a group that is a polymer chain is even more preferable.

The coupled dye-forming compound having a group that is a polymer chain is preferably one having a polymer chain having a repeating unit derived from a monovalent unit represented by -(b) as the group.

General formula (b) Cp-+J+-+Y+V-+Z←→L) In the formula, Cp,
J has the same meaning as defined in general formula (a), Y represents an alkylene group, arylene group, or aralkylene group, i represents O or 1, Z represents a 21 illi barbed base, and L is Represents an ethylenically unsaturated group or a group having an ethylenically unsaturated group.

Specific examples of coupling dye-forming compounds represented by general formulas (a) and (b) include JP-A-59-124339
No. 59-181345, No. 60-2950, JP-A-61-57943, JP-A-61-59336, U.S. Pat. No. 4,631,251, U.S. Pat. No. 4,650,748,
4,656,124, particularly U.S. Patent Nos. 4,656,124, 4,631,251, 4,650, and 748. Preferred are the polymeric dye-providing materials described in the book.

As a positive dye-donating substance, for example, JP-A-59-
Dye developer compounds described in publications such as No. 55430 and No. 59-165054, for example, JP-A-59-15444
Compounds that release diffusible dyes by intramolecular nucleophilic reaction described in publications such as No. 5 and No. 59-766954, cobalt complex compounds described in publications such as JP-A-59-116655, or e.g. There are compounds that lose their dye-releasing ability when oxidized and are described in publications such as No. 59-124327 and No. 59-152440.

In order to improve the diffusivity of the dye, the residual base of the diffusible dye in the dye-donating substance used in the present invention preferably has a molecular weight of 800 or less, more preferably 600 or less; Examples include residues such as azomethine dyes, anthraquinone dyes, naphthoquinone dyes, styryl dyes, nitro dyes, quinoline dyes, carbonyl dyes, and phthalocyanine dyes. These dye residues may be in a temporary short wave form that can be restored during hot agglomeration or transfer. In addition, these dye residues are used for the purpose of improving the light resistance of images, for example, in JP-A-5'14876FM'j and JP-A-5'
A preferred embodiment is a chelatable dye residue described in Japanese Patent No. 0-124337.

These dye-providing substances may be used alone or in combination of two or more. The amount used is not limited, and depends on the type of dye-providing substance, whether it is used alone or in combination, or whether the photographic constituent layer of the heat developable material of the present invention is a single layer or a multilayer of two or more types. For example, the usage m may be o per 1f, 500 to oos, preferably 0.1! ; 1 to 10 times can be used.

In the present invention, it is preferable to contain an antifoggant in a silver halide emulsion layer containing a silver halide emulsion chemically sensitized in the presence of inorganic sulfur or in a layer adjacent thereto. Examples of antifoggants that can be used in the present invention include higher fatty acids described in U.S. Pat. No. 3,645,739,
Mercury salt described in Publication No. 13, JP-A-51-4741
N-halogen compounds described in U.S. Patent No. 3.
700.457, mercapto compound-releasing compounds described in JP-A No. 51-50725, JP-A No. 49-1
Aryl sulfonic acid described in Publication No. 25016, No. 51
-Carboxylic acid lithium salt described in Publication No. 47419g, British Patent No. 1,455,271, JP-A-1988-1
Oxidizing agent described in Publication No. 01019, No. 53-19825
Sulfinic acids or thiosulfonic acids described in No. 51-3223, 2-diorcracils described in No. 51-26019, simple sulfur described in No. 51-26019,
No. 42529, No. 51-81124, No. 55-931
Disulfide and polysulfide compounds described in Publication No. 49, rosins or diterpenes described in Publication No. 51-57435, polymer acids having free carboxyl groups or sulfone am described in Publication No. 51-104338, and U.S. Patent No. 4 , No. 138,265, Akira Stow, JP-A-1973-! No. 11821, 1 described in U.S. Patent No. 4137,079
．． 2.4-triazole or 5-mercapto-1,
2,4-triazole, thiosulfinic acid esters described in JP-A No. 5'l-140883, No. 55-142
1,2,3,4-thiatriazoles described in Publication No. 331, No. 59-46641, No. 59-57233,
Dihalogen compounds or trihalogen compounds described in Publication No. 59-57234, and furthermore, No. 59-11163.
Thiol compound described in Publication No. 60-19854
Examples include hydroquinone derivatives described in Publication No. 0.

Among them, in the present invention, nitrogen-containing heterocyclic mercapto compounds having a development accelerating ability or a fog preventing function are preferably used.

Various additives may be added to the heat developable material of the present invention as necessary. Such additives include, for example, thermal solvents, development accelerators, acid or base precursor hardeners, optical brighteners,
Known photographic additives such as antihalation agents, filter dyes, antistatic agents, matting agents, and dye image stabilizers can be used.

Specifically, RD (Research Disclosure) magazine v
o1.170. June 1978 issue No. t702
No. 9, JP-A-62-135825, JP-A-63-31
No. 6848 and Toku-m No. 19338/1983.

The heat developable material of the present invention comprises (a) photosensitive silver halide, (
b) Contains a reducing agent and (C) a binder. Furthermore, it is preferable to contain (d) a dye-providing substance and/or (e) significant silver, if necessary. Basically, these may be contained in one heat-developable photosensitive layer, but they do not necessarily need to be contained in a single photographic constituent layer. For example, if the heat-developable photosensitive layer is divided into two layers, a), (b), (c),
It is also possible to avoid containing component (e) in one heat-developable photosensitive layer and to contain a dye-providing substance<d) in the other layer adjacent to this photosensitive layer. It may be contained in a layer adjacent to the photosensitive layer containing the phosphor, or it may be contained in two or more constituent layers as long as they are in a state where they can react with each other.

Further, the heat-developable photosensitive layer may be divided into two or more layers: a low-sensitivity layer and an iris-sensitivity layer, a high-density layer and a low-density layer, or more.

When the heat-developable material of the present invention is a color photosensitive material having two or more heat-developable photosensitive layers, generally three heat-developable photosensitive layers having different color sensitivities are used, and each photosensitive layer has the following properties: Thermal development forms or releases dyes of different hues.

When the heat developable material of the present invention is used as a full-color photosensitive material, a blue-sensitive layer, a green-sensitive layer, a red-sensitive layer and an infrared-sensitive layer can be used in any combination.

Moreover, the combination of each photosensitive layer and coloring dye is also arbitrary, and a yellow dye-providing substance, a magenta dye-providing substance, and a cyan dye-providing substance can be used in any combination with each photosensitive layer.

Typically, a yellow dye is used in the blue-sensitive layer, a magenta dye is used in the green-sensitive layer, and a cyan dye is used in the red-sensitive layer, but the invention is not limited to this.

In addition to the heat-developable photosensitive layer, the heat-developable material of the present invention can be provided with non-photosensitive layers such as an undercoat layer, an inner tube layer, a protective layer, a filter layer, a backing layer, and a release layer. To coat the heat-developable photosensitive layer and these non-photosensitive layers on the support, a method similar to that used for coating and preparing general silver halide photosensitive materials can be applied.

In general, exposure to obtain a photographic image is performed using various known light sources including infrared light, such as a tungsten electric lamp, a cathode ray flying spot, a light emitting diode, and a laser beam (e.g., gas laser, YAG laser, dye laser, semiconductor laser, etc.). Either can be used. Also, electron beam,
Exposure may be performed by light emitted from a phosphor excited by X-rays, rWA, α-rays, or the like. Exposure times include not only exposure times of 1/1000 seconds to 1 second, which are normally used with cameras, but also exposure times shorter than 1/1000 seconds, such as 1/10 to 1/10" using xenon flash lamps and cathode ray tubes.
Second exposures can also be used. If necessary, the spectral composition of the light used for exposure can be adjusted using a color filter. The heat developable material of the present invention is particularly suitable for scanner exposure using a laser.

When the heat developable material of the present invention has at least one infrared-sensitive layer, it is preferable to use a semiconductor laser as the light source for providing exposure to infrared light.

In the case of a full-color photosensitive material, a plurality of light sources are required, but for example, visible light emitting lasers can be used in combination. Preferably a gas laser (He-N
e laser, Ar + ion laser, 1He-Cd laser, etc.), a semiconductor laser, a semiconductor laser and a second harmonic generation element (St (G element), etc.) can be used.

The heat developable material of the present invention is usually preferably 80°C after imagewise exposure.
Developing is carried out by simply heating at a temperature range of -200°C, more preferably 100°C - 170°C, preferably 1 second - 180 seconds, more preferably 15 seconds - 120 seconds. The transfer of the diffusible dye to the image-receiving layer, which is a preferred embodiment of the heat-developable color sensitive material, may be carried out simultaneously with heat development by bringing the image-receiving member into close contact with the light-sensitive surface of the photosensitive material and the image-receiving layer. Alternatively, the image may be transferred by being brought into close contact with an image receiving member after thermal development, or by being brought into close contact with an image receiving member after supplying water and further heated if necessary. Also, before exposure, 70℃
Preheating may be performed in a temperature range of ~180°C.

Also, Japanese Patent Application Publication No. 60-143338, Japanese Patent Application No. 60-36
As described in No. 44, in order to improve mutual adhesion, the photosensitive material and image receiving member were heated at 60°C immediately before thermal development transfer.
Each may be preheated at a temperature of ~250°C.

The hot mass of the present invention! Various heating means can be used for A0.

As the heating means, all methods that can be applied to ordinary heat-transferable materials can be used, such as contacting with a heated block or plate, contacting with a heated roller or drum, or passing through a high-temperature atmosphere. Alternatively, high-frequency heating may be used, or furthermore, a conductive layer containing a conductive substance such as carbon black may be provided on the back surface of the photosensitive material of the present invention or the back surface of the image receiving member for thermal transfer, and the Joule heat generated by energization may be utilized. You can also do that. There are no particular restrictions on the heating pattern, including methods of preheating (breheating) and then reheating, heating at a high temperature for a short time, or at a low temperature for a long time, continuously rising, continuously falling, or repeating these methods. Although discontinuous heating is also possible, a simple pattern is preferred. Alternatively, a method in which exposure and heating proceed simultaneously may be used.

Receiver 1lII of image receiving member effectively used in the present invention
LiIi may be any material that has the function of receiving the dye in the heat-developable photosensitive layer released or formed by heat development, such as a polymer containing a tertiary amine or a quaternary ammonium salt; Those described in No. 3,709.690 are preferably used. Typical image-receiving layers for diffusion transfer include ammonium salts,
It can be obtained by mixing a polymer containing a tertiary amine or the like with gelatin, polyvinyl alcohol, or the like and coating the mixture on a support.

Another useful dye-receiving material is JP-A-57-207
Examples include those made of a heat-resistant polymer material having a glass transition temperature of 40° C. or higher and 250° C. or lower, as described in Japanese Patent No. 250 or the like.

These polymers may be supported on a support as an image-receiving layer, or may themselves be used as a support.

Examples of the heat-resistant polymer substances include polystyrene, polystyrene derivatives having a substituent having 4 or less carbon atoms, poly7-cetal such as polyvinylcyclohexane, polydivinylbenzene, polyvinylcarbazole, polyallylbenzene, polyvinyl formal, and polyvinyl butyral. , polyvinyl chloride, chlorinated polyethylene, polytrichloride fluoroethylene, polyacrylonitrile, poly-N
.

N-dimethylallylamide, polyacrylate with p-cyanophenyl group, pentachlorophenyl group and 2,4-dichlorophenyl group, polyacrylchloroacrylate, polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polyisopropyl methacrylate, polyisobutyl methacrylate, poly tert-butyl methacrylate, polycyclohexyl methacrylate, polyethylene glycol dimethacrylate, poly-2-cyano-ethyl methacrylate,
Examples include polyesters such as polyethylene isophthalate, polycarbonates such as polysulfone and bisphenol A polycarbonate, polyanhydrides, polyamides, and cellulose acetates. Also,[
"Polymer Handbook, Second Edition" (edited by Joy Brandrup and E.A.I. Inmargat), published by John Willian and Sands (polym
erHandbook 2nd ed, (
, ], Brandrup, E.
H.

11serout 1m > John W 1le
Also useful are synthetic polymers with glass transition temperatures of 40° C. or higher, such as those described in J. Generally, the molecular group of the polymer substance is 2,000 to 200,000.
is useful. These polymeric substances may be used alone or in a blend of two or more types, or may be used in combination of two or more types as a copolymer.

A particularly preferable image-receiving layer is JP-A-59-22342
Examples include a layer made of polyvinyl chloride as described in Japanese Patent Publication No. 5, and a layer made of polycarbonate as described in Japanese Patent Application Laid-open No. 19138/1983.

These polymers can also be used as a support and an image-receiving layer (image-receiving member), in which case the support may be formed from a single layer or from multiple layers. good.

As the support for the image receiving member, any material such as a transparent support or an opaque support may be used, but for example, films such as polyethylene terephthalate, polycarbonate, polystyrene, polyvinyl chloride, polyethylene, polypropylene, etc.
and supports containing pigments such as titanium oxide, barium sulfate, calcium carbonate, talc, etc., baryta paper, RC paper in which thermoplastic resin containing pigments is laminated on paper, cloth, Glasses, metals such as aluminum, etc., supports prepared by coating and curing electron beam curable resin compositions containing pigments on these supports, and supports containing pigments in some of these supports. Examples include a support provided with a coating layer. Furthermore, the cast coated paper described in JP-A-62-283333 is useful as a support.

In addition, a support is prepared by coating and curing an electron beam curable resin composition containing a pigment on paper, or a support having a pigment coating layer on paper and an electron beam curable resin composition on the pigment coating layer. The support coated with and cured can be used as an image receiving member as it is because the resin layer itself can be used as a receiving layer.

The heat developable material of the present invention is published in RD (Research Disclosure Magazine) No. 15108, JP-A-57-198458.
It can be a so-called monosheet type photothermographic material in which a photosensitive layer and an image-receiving layer are formed on the same support, as described in Japanese Patent No. 57-207250 and Japanese Patent No. 61-80148. .

[Example] Hereinafter, specific examples of the present invention will be described. However, the present invention is not limited to this.

Example-1 An octahedral silver iodobromide monodisperse emulsion EMP-1 (AoI composition 2.1 mol%, grain size distribution (coefficient of variation 10%) was prepared.

α-Sulfur and sodium thiosulfate as a chemical sensitizer were added in the amounts shown in Table 1 to the obtained silver iodobromide monodispersed emulsion EMP-1, and surface chemical sensitization was carried out under optimal conditions. Silver iodobromide emulsions EM-1 to EM-6 were prepared. (l during chemical sensitization) A! It -7,0) Furthermore, at the end of chemical sensitization, 1.2 g of 4 per mole of silver halide was added as a stabilizer.
-Hydroxy-6-methyl-1,3,3a,7-chitrazaindene 5T-4 was added.

Then, using the obtained EM-1 to EM-6, heat developable color sensitive materials 1 to 6 having the configurations shown in Table 2 were prepared.

On the other hand, an image-receiving layer having a structure not shown in Table 3 was coated on 120 (1/l') art paper to prepare image-receiving material-1.

After applying short-time light 1a'fi for 10-6 seconds to each of the heat-developable color photosensitive materials 1 to 6, the image-receiving material-1 and each heat-developable color photosensitive material were superimposed and heated to 60°C at 150°C. A second heat development process was performed.

After the heat development process, when the image receiving member was peeled off from the heat developable color sensitive material, a negative cyan image was obtained on the image receiving layer, and its anti-tAm degree and sensitivity were measured. The results (immediate performance) are shown in Table 4.

On the other hand, each of the above-mentioned heat-transferable color photosensitive materials 1 to 6 was stored for 7 days under the following conditions: (1) 50°C and 20% relative humidity, or (2) 40°C and 80% relative humidity, and was exposed to light for a short time in the same manner as above. The reflection density and sensitivity were measured after thermal treatment. The results are shown in Table 4.

Table 1 Note: All additives are expressed in amounts per mole of silver halide.

Hot melt M-1 Polymer dye-donating rostrum (1) y=40 1% by weight Activator-1 CH, -COOCH, (CFICF2)mHNa03S
-CHCOOCHi(CFaCFa)nH(3+n=5
) Table-3 Image stabilizer-1 Image stabilizer-2 n, I00 Activator-2 CHz C00CH2CH-C4HeNa03S-C
HCOOCH, -CH-C, HsC,H.

Hardener-1 C(CH,SO,CH=CH,), and KO,SCH,N
1:0.75 (mole ratio) of the reactants^boiling point organic solvent-1 image stabilizer-3 development accelerator-1 (HOC, H, SCH juice) was then treated in the same manner as in Example 1. Conduct, immediate performance,
Sensitivity and anti-tJ4m degree under conditions (1) or (2) were measured.

The results are shown in Table-6.

Table 5 Note) All additions m are expressed in amounts per 1 mole of silver halide. It can be seen that all of the current color photosensitive materials 2 to 6 have higher maximum density and sensitivity in immediate performance than the comparative samples. On the other hand, when stored at 50°C and 20% relative humidity and (1) 40°C and 80% relative humidity for 7 days, the heat developable material of the present invention suppresses the increase in minimum density and the decrease in maximum density, and also It can be seen that the desensitizing effect of time was significantly improved. In particular, it can be seen that when 0.002 mo or more of inorganic sulfur is added per mole of silver halide, the desensitization effect during high-humidity storage is particularly prevented.

Example 2 Surface chemical sensitizers were prepared from a combination of inorganic sulfur and sodium thiosulfate to inorganic sulfur, sodium thiosulfate and gold chloride (
1) Silver iodobromide emulsions EM-7 to EM-11 were prepared in the same manner as in Example 1, except that the combination of sodium chloride was changed and the amounts shown in Table 5 were added, and then in the same manner as in Example 1. As is clear from the results in Table 6, heat-developable color photosensitive materials 7 to 11 were obtained by chemically sensitizing them in the presence of inorganic sulfur in the same manner as in Example 1. The heat-developable color sensitive materials (8 to 11) using silver halide emulsions had higher density and better storage performance than Comparative Sample 7.

Fruit/II! Example i-3 Antifoggant-1 shown below in the silver halide emulsion layer,
Heat developable color photosensitive materials 12 to 1 were prepared in the same manner as in Example 2 except that antifoggant-2 and antifoggant-3 were added in the following amounts.
6 was created. Using the obtained heat-developable color photosensitive material, processing was carried out in the same manner as in Example 2, and the sensitivity and reflection temperature were measured. The results are shown in Table-7.

Antifoggant-1 Antifoggant-2 Antifoggant-3 (Additional amount 0.02g) (Additional amount 0.0ig) (Additional amount 0.004g) r 2■ As is clear from Table 7, antifoggant The effects of the present invention can also be obtained in a system in which the emulsion agent is added to the emulsion layer.

Example-4 α-sulfur, thio [! Same as Example 3, except that sodium, gold(III)M chloride, 1-lium chloride, and the sensitizing dyes shown in Table 8 were added in the sum shown in Table 8, and each surface was chemically sensitized to the optimum sensitivity. Silver halide emulsions EM-12 to EM-31 were prepared. Next, using each of the obtained emulsions EM-12 to -31, heat developable color photosensitive material 1 was prepared in the same manner as in Example 3, except that 10.04 g of an antifoggant was further added to the protective layer.
Samples Nos. 7 to 36 were prepared, and the sensitivity and reflection density were measured in the same manner as in Example 3. The results obtained are shown in Table-9.

Table note: All amounts added are per mole of silver halide.

Sensitizing dye BS Sensitizing dye GS Sensitizing dye R3 Sensitizing dye IFS As is clear from the results in Table 9, when using a silver halide emulsion that was chemically ripened in the presence of a sensitizing dye, It was also found that the effects of the present invention can be obtained.

Example 5 In the same manner as in Example 1, 1) Ammonia with an average particle size of 0.21μ
A tetrahedral silver bromide dispersion emulsion E M l) = 2 (coefficient of variation of grain size distribution 12%) was prepared.

However, when the average particle size is 0.13μ flash, it becomes 31rCf.
Fis was added in an amount of 10-6 mol per mol of silver halide.

On the other hand, using a silver iodobromide emulsion with an average grain size of 0°16 μm as a seed emulsion, silver bromide was shelled by the ammonia method with ρAg controlled, and a cubic silver iodobromide monodisperse with an average grain size of 0.24 μm was obtained. Emulsion EMP-3 (contains 1.4 mol% silver iodide)
0 particle size distribution (coefficient of variation 9%) was prepared.

Table-1 using EMP-1, EMP-2 and EMP-3
Green, red and infrared sensitive silver halide emulsions EM-32 to EM-40 were prepared using chemical sensitizers and spectral sensitizers of the type and intensity shown in Table 1. However, at the end of chemical ripening, 1.6 g of 5T-4 was added per mole of silver halide as a stabilizer.

Next, each of the photosensitive silver halide emulsions obtained was used to prepare a multilayer thermal mass color sensitive material 3 having the layer structure shown in Table 11.
7 to 39 were created. The combinations of each photosensitive silver halide emulsion are shown in Table-12.

Evaluations were conducted in the same manner as in Example 1 using each of the obtained heat-developable color photosensitive materials 37 to 39. The results are shown in Table-12.

Heat solvent-2 Antifoggant-3 C2H.

C, H.

Color stain prevention agent-1 Polymer dye-donating substance (2) Polymer dye-donating substance (3) In Table 12, measurement lights B, G, and R refer to the obtained yellow O-, magenta, and cyan, respectively. This represents that each dye image was subjected to reflection density measurement using blue, green, and red monochromatic lights. From the results shown in Table 12, it was found that the effects of the present invention can be obtained even in multilayer hot-bulb color sensitive materials.

Example 6 Same as Example 5 except that during chemical sensitization, nitrogen-containing heterocyclic compounds (exemplified compounds M-12, M-61) were further added in amounts shown in Table 13. Silver halide emulsions EM-41 to EM-49 and EM-50 to EM-58 were prepared in the same manner. Using the obtained silver halide emulsion, Example-5
Heat-developable color sensitive materials 40 to 45 were prepared with the same layer structure. (The combinations of each photosensitive silver halide emulsion are shown in Table-14.) However, the infrared-sensitive silver halide emulsion in the infrared-sensitive layer is replaced with the blue-sensitive silver halide emulsion shown in Table-13. A blue-sensitive layer was formed, and the following yellow filter dye YF-1 was added to the second intermediate layer in an amount of o.zig.

F-1 Next, evaluation was carried out in the same manner as in Example-5, and from the results shown in Table-14, chemical sensitization was performed by further adding a nitrogen-containing heterocyclic compound during chemical sensitization.
It can be seen that even more remarkable effects of the present invention can be obtained.

When using an emulsion in which nitrogen-containing heterocyclic compound M-12 was chemically sensitized using nitrogen-containing heterocyclic mercapto compound M-61, there was no particular decrease in maximum density and the effect of the present invention was achieved. You can see what you can get. Furthermore, it can be seen that the decrease in sensitivity during storage is smaller when M-61 is used and inorganic sulfur is used.

[Effects of the Invention] As described in detail above, the present invention prevents the desensitization effect caused by reducing agents during storage, especially during storage under high humidity conditions,
Furthermore, it is possible to provide a heat developable material that provides a high maximum density and a low minimum density.

Claims (1)

[Claims] A heat-developable photosensitive material having a binder, a photosensitive silver halide, and a reducing agent on a support, having at least one silver halide emulsion layer containing a photosensitive silver halide chemically sensitized in the presence of inorganic sulfur. A heat-developable photosensitive material characterized by: