JP2007079418A - Silver salt photothermographic dry imaging material and image recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silver salt photothermographic dry imaging material provided with satisfactory lubricity without affecting photographic performance, and an image recording method using the same. <P>SOLUTION: The silver salt photothermographic dry imaging material has on a support a photosensitive layer containing an organic silver salt, photosensitive silver halide grains and a reducing agent, wherein at least one layer on the support contains organic solid lubricant particles having an average particle diameter of 0.5-30 μm, and the organic solid lubricant particles are metallic soap. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel silver salt photothermographic dry imaging material and image recording method, and more particularly to a silver salt photothermographic dry imaging material excellent in photographic performance and transportability and an image recording method using the same.

  Conventionally, in the field of printing plate making and medical treatment, waste liquids resulting from wet processing of image forming materials have been a problem in terms of workability, and in recent years, the amount of processing waste liquids has been reduced from the viewpoint of environmental conservation and space saving. It is strongly desired. Therefore, there has been a demand for technology relating to photothermographic dry imaging materials for photographic technology that can be efficiently exposed by a laser image setter or a laser imager and can form a clear black image with high resolution. .

  As a technique for solving the above problems, silver salt photothermographic dry imaging materials for forming a photographic image using a heat developing method are disclosed in, for example, U.S. Pat. Nos. 3,152,904, 3,457,075 and D.I. Morgan and B.M. "Thermally Processed Silver Systems" by Shely (Imaging Processes and Materials) Nebelte 8th Edition, Sturges. (Walworth), A. Shepp, 2nd page, 1969).

  Such a silver salt photothermographic dry imaging material generally has a photosensitive layer on a support such as plastic, and a silver salt such as an intermediate layer, a protective layer, a backing layer, an antihalation layer, and an antistatic layer, if necessary. Various constituent layers of the photothermographic dry imaging material are applied in combination. Silver salt photothermographic dry imaging materials can be used to contact various devices with silver salt photothermographic dry imaging materials during coating, drying, processing, etc. Between the surface side and the backing surface, it is often undesirably affected by the contact between the silver salt photothermographic dry imaging materials. For example, scratches and scratches on the surface of the silver salt photothermographic dry imaging material, and deterioration of the transportability of the silver salt photothermographic dry imaging material in the developing device may occur.

  For this purpose, for example, a method of improving using an alkylsilane compound having 8 or more carbon atoms (for example, see Patent Document 1), or a sulfur-based or ester-based slipping agent having a long-chain alkyl group. Although a method to be used (for example, see Patent Document 2) is disclosed, each method has a problem in that the effect on the photographic performance is manifested and the color tone is deteriorated, and in a heat developing machine having a high temperature atmosphere. There is a problem that the heat developing machine is contaminated and sufficient slipperiness cannot be imparted at high temperatures. From such a viewpoint, a method using an inorganic solid lubricant is disclosed as one of the improvement methods (for example, see Patent Document 3).

Recently, the conveying speed in the developing device and the processing speed in the automatic developing machine have been further increased, and there is a demand for further improvement in slipperiness.
US Pat. No. 6,020,117 JP 2001-5137 A JP 2001-116520 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a silver salt photothermographic dry imaging material having sufficient slipperiness without affecting photographic performance, and image recording using the same. Is to provide a method.

  The above object of the present invention can be achieved by the following constitution.

  (1) In a silver salt photothermographic dry imaging material having a photosensitive layer containing an organic silver salt, photosensitive silver halide grains and a reducing agent on a support, at least one layer on the support has an average particle size of 0. A silver salt photothermographic dry imaging material comprising 5-30 μm organic solid lubricant particles, wherein the organic solid lubricant particles are a metal soap.

  (2) The silver salt photothermographic dry imaging material as described in (1) above, wherein the organic solid lubricant particles have a melting point of 110 ° C. or higher and 200 ° C. or lower.

  (3) The silver salt photothermographic dry imaging as described in (1) or (2) above, wherein the organic solid lubricant particles are organic solid lubricant particles represented by the following general formula (1): material.

General formula (1)
_{(R 1) -COO-M-} OOC- (R 2)
[R ₁ and R ₂ each represent a substituted or unsubstituted alkyl group, alkenyl group, aralkyl group or aryl group having 2 to 60 carbon atoms, and M represents a divalent metal. R ₁ and R ₂ may be the same or different. ]
(4) The (1) to (3), wherein the organic solid lubricant particles are particles having a solubility in a solvent of 0.5% by mass or less and an average particle size of 0.5 to 30 μm. The silver salt photothermographic dry imaging material according to any one of the above.

  (5) having a photosensitive layer formed by coating a photosensitive emulsion containing at least an organic silver salt, photosensitive silver halide grains and a solvent, a composition containing a reducing agent and a binder, and the photosensitive layer or non-photosensitive layer The silver salt photothermographic dry imaging material according to any one of (1) to (4), wherein the layer contains a silver saving agent.

  (6) A compound that generates reactive species capable of oxidizing silver by exposure to ultraviolet light or visible light, or the reducing agent is deactivated so that silver ions of the organic silver salt cannot be reduced to silver. The silver salt photothermographic dry imaging material according to any one of (1) to (5) above, wherein the silver salt photothermographic dry imaging material comprises two or more kinds of compounds capable of generating reactive active species.

  (7) In the image recording method onto the silver salt photothermographic dry imaging material described in any one of (1) to (6) above, exposure is performed by a laser beam scanning exposure machine in which the scanning laser beam is a double beam. An image recording method characterized by comprising:

  (8) In the image recording method onto the silver salt photothermographic dry imaging material described in any one of (1) to (6) above, exposure is performed by a laser beam scanning exposure machine in which the scanning laser beam is a vertical multi. An image recording method.

  (9) The silver according to any one of (1) to (6), wherein a hue angle hab (JIS Z 8729 standard) after heat development is 180 degrees <hab <270 degrees. Salt photothermographic dry imaging material.

  (10) The photosensitive layer according to any one of (1) to (6), wherein the photosensitive layer is formed using a photosensitive layer forming coating solution containing 30% by mass or more of water. Silver salt photothermographic dry imaging material.

  (11) The silver salt photothermal heat described in any one of (1) to (6), (9), and (10), wherein the processing is carried out at a conveying speed of 30 mm / sec or more during heat development. Photo dry imaging material.

According to the present invention, it is possible to provide a silver salt photothermographic dry imaging material having sufficient slip properties without affecting photographic performance and an image recording method using the same.
It is.

  Hereinafter, although the best mode for carrying out the present invention will be described, the present invention is not limited to these.

  Details of the present invention will be described below.

  In the silver salt photothermographic dry imaging material of the present invention (hereinafter also referred to as photosensitive material or imaging material), at least one layer on the support contains organic solid lubricant particles having an average particle size of 0.5 to 30 μm. One of the characteristics is that the melting point of the organic solid lubricant particles is preferably 110 ° C. or more and 200 ° C. or less. The average particle size is preferably 0.5 to 20 μm, and more preferably 0.5 to 10 μm. The melting point is more preferably 110 ° C. or higher and 180 ° C. or lower. Moreover, it is preferable that the solubility to a solvent is 0.5 mass% or less (0.5-0 mass%).

In the organic solid lubricant particles represented by the general formula (1) according to the present invention, the total carbon number is not particularly limited, but is generally preferably 10 to 24, more preferably 12 to 20. Examples of the substituent which the alkyl group, alkenyl group, aralkyl group or aryl group in the definition of R ₁ and R ₂ may have include, for example, a halogen atom, a hydroxy group, a cyano group, an alkoxy group, an aryloxy group Alkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, amino group, acylamino group, sulfonylamino group, ureido group, carbamoyl group, sulfamoyl group, acyl group, sulfonyl group, sulfinyl group, aryl group and alkyl group Can be mentioned. These groups may further have a substituent. Preferred substituents are a halogen atom, hydroxy group, alkoxy group, alkylthio group, alkoxycarbonyl group, acylamino group, sulfonylamino group, acyl group and alkyl group. As a halogen atom, a fluorine atom and a chlorine atom are preferable.

The alkyl component in the alkoxy group, alkylthio group and alkoxycarbonyl group is the same as the alkyl group of R ₂ described later. The amino group of the acylamino group and sulfonylamino group may be an N-substituted amino group, and the substituent is preferably an alkyl group. The groups bonded to the acylamino group, the carbonyl group of the acyl group, and the sulfonyl group of the sulfonylamino group are an alkyl group and an aryl group, and the above alkyl groups are preferred.

R ₁ and R ₂ may be linear, branched, or cyclic structures, or may be a mixture thereof. Examples of preferred R ₁ and R ₂ include octyl, t-octyl, dodecyl, tetradecyl, hexadecyl, 2 _- hexyldecyl, octadecyl, C _n H _2n-1 (n represents 20 to 60), eicosyl, docosanyl, Menlicinyl, octenyl, myristolyl, oleyl, erucyl, phenyl, naphthyl, benzyl, nonylphenyl, dipentylphenyl, cyclohexyl groups and groups having these substituents can be exemplified. M represents a divalent metal.

  Examples of the metal soap of the general formula (1) that is the organic solid lubricant particles in the present invention include caprylic acid, capric acid, lauric acid, myristic acid, myristic acid, palmitic acid, isopalmitic acid, palmitoleic acid, stearic acid, Representative of simple fatty acids such as behenic acid, lignoceric acid, serotic acid, montanic acid, isostearic acid, oleic acid, arachic acid, ricinoleic acid, linolenic acid, behenic acid and erucic acid, beef tallow fatty acid, soybean oil fatty acid, coconut oil fatty acid Of saturated fatty acids having 4 or more carbon atoms or unsaturated fatty acids and alkaline earth metals such as calcium, barium and magnesium, and divalent metals such as titanium, zinc, copper, manganese, cadmium, mercury, zirconium, lead and iron In particular, it is saturated with 10 to 24 carbon atoms, preferably 12 to 22 carbon atoms. Calcium salts of fatty acids or unsaturated fatty acids, zinc salts, and barium salts are preferred. You may use these 1 type or in mixture of 2 or more types.

Although an example of the metal soap which is an organic solid lubricant particle is shown below, in this invention, it is not limited to these.
1-1 Calcium palmitate 1-2 Barium palmitate 1-3 Zinc palmitate 1-4 Magnesium stearate 1-5 Barium stearate 1-6 Calcium stearate 1-7 Zinc stearate 1-8 12-hydroxy magnesium stearate 1-9 barium 12-hydroxystearate 1-10 calcium 12-hydroxystearate 1-11 zinc 12-hydroxystearate 1-12 calcium behenate 1-13 zinc behenate 1-14 magnesium behenate 1-15 copper behenate 1-16 Magnesium laurate 1-17 Zinc laurate 1-18 Barium laurate 1-19 Calcium laurate 1-20 Calcium montanate 1-21 Barium montanate 1-22 Zinc montanate 1-23 Nesium 1-24 Nickel Oleate 1-25 Zinc Myristate 1-26 Calcium Myristate 1-27 Magnesium Myristate 1-28 Tallow Fatty Acid Zinc 1-29 Tallow Fatty Acid Calcium 1-30 Tallow Fatty Acid Magnesium The particle size of the metal soap is defined as having an average representative length of the metal soap particles. As the average representative length, commonly known definitions can be used. For example, biaxial average diameter, triaxial average diameter (arithmetic average diameter), harmonic average diameter, surface area average diameter, and standing volume Average diameter, circumscribed rectangle equivalent diameter (Breigel diameter), square equivalent diameter (Goodman diameter), circular equivalent diameter (Heywood diameter), rectangular parallelepiped equivalent diameter (geometric mean diameter), cylindrical equivalent diameter (Asano diameter), cube equivalent diameter (Andrea) Zen diameter), spherical equivalent diameter (Wandell diameter), constant direction diameter (green diameter, ferret diameter), constant equal diameter, Nassenstein diameter, Stokes diameter, and the like. In the present invention, a general particle size distribution measuring method is used as a method for measuring the particle size defined by these. Examples of the measuring method include a precipitation method (gas phase precipitation method, liquid phase precipitation method, light transmission method) based on Stokes' law, a microscope method, a light scanning method, a laser diffraction scattering method, and the like. Among them, in the method for measuring metal soap particles described in the present invention, an optical scanning method, a laser diffraction scattering method, and the like, which are capable of measuring accuracy for finer particles, are preferably used.

  There is no limitation in particular as an addition layer of the metal soap used for this invention, Although it may exist in any layer, It is preferable to contain in an outermost surface layer.

  Next, each component of the silver salt photothermographic dry imaging material of the present invention will be described.

[Photosensitive silver halide grains]
First, photosensitive silver halide grains (hereinafter also simply referred to as silver halide grains) used in the silver salt photothermographic dry imaging material of the present invention will be described.

  The photosensitive silver halide grains in the present invention can inherently absorb light as an intrinsic property of silver halide crystals, or artificially generate visible light or infrared light by a physicochemical method. Physicochemical changes can occur in the silver halide crystal or on the crystal surface when absorbing light in any region within the light wavelength range from the ultraviolet light region to the infrared light region. The silver halide crystal grains processed and manufactured as described above.

  The silver halide grains themselves used in the present invention are P.I. Chifie et Physique Photographic (published by Paul Montel, 1967) by Glafkides. F. Duffin's Photographic Emission Chemistry (published by The Focal Press, 1966), V.C. L. It can be prepared as a silver halide grain emulsion using the method described in Making and Coating Photographic Emulsion (published by The Focal Press, 1964) by Zelikman et al. That is, any of an acidic method, a neutral method, an ammonia method, etc. may be used, and the formation of reacting a soluble silver salt and a soluble halogen salt may be any one of a one-side mixing method, a simultaneous mixing method, and a combination thereof. Of these methods, the so-called controlled double jet method, in which silver halide grains are prepared while controlling the formation conditions, is preferred.

  The halogen composition is not particularly limited and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide. Silver chloride or silver iodide is particularly preferred.

  In the case of silver iodobromide, the iodine content is preferably in the range of 0.02 to 16 mol% / Agmol. Even if iodine is contained so as to be distributed throughout the silver halide grains, the iodine concentration in a specific portion of the silver halide grains, for example, the central portion of the grains is increased, and the concentration in the vicinity of the surface is decreased or substantially reduced. It may be a core / shell structure that is zero.

  Grain formation is usually divided into two stages: silver halide seed grain (nuclear grain) generation and grain growth, and these may be performed continuously at one time, or nucleus (seed grain) formation and grain growth are separated. It is also possible to do this. As the particle forming conditions, a controlled double jet method in which particles are formed by controlling pAg, pH and the like is preferable in that the particle shape and size can be controlled. For example, in the case of a method in which nucleation and grain growth are performed separately, first, a soluble silver salt and a soluble halogen salt are uniformly and rapidly mixed in an aqueous gelatin solution to perform nucleation (nucleation step). Silver halide grains are prepared by a grain growth process in which grains are grown while supplying a soluble silver salt and a soluble halogen salt under controlled pAg, pH, and the like.

  The silver halide grains used in the present invention preferably have a smaller grain size of the silver halide grains in order to keep white turbidity and color tone (yellowishness) after image formation low and to obtain good image quality. As a value when particles having a diameter of less than 0.02 μm are excluded from measurement, 0.030 μm or more and 0.055 μm or less are preferable.

  Here, the grain size means the length of the edge of the silver halide grain when the silver halide grain is a so-called normal crystal of a cube or octahedron. Further, when the silver halide grain is a tabular grain, it means the diameter when converted into a circular image having the same area as the projected area of the main surface.

  In the present invention, the silver halide grains are preferably monodispersed. The term “monodispersed” as used herein means that the coefficient of variation of the particle diameter obtained by the following formula is 30% or less. Preferably it is 20% or less, More preferably, it is 15% or less.

Coefficient of variation of particle size = standard deviation of particle size / average value of particle size × 100 (%)
Examples of the shape of the silver halide grains include cubes, octahedrons, tetradecahedral grains, tabular grains, spherical grains, rod-shaped grains, and potato grains. Among these, in particular, cubic, octahedral, Tetrahedral and tabular silver halide grains are preferred.

  When tabular silver halide grains are used, the average aspect ratio is preferably 1.5 or more and 100 or less, more preferably 2 or more and 50 or less. These are described in US Pat. Nos. 5,264,337, 5,314,798, 5,320,958, etc., and the desired tabular grains can be easily obtained. Further, grains having rounded corners of silver halide grains can be preferably used.

  The crystal habit on the outer surface of the silver halide grain is not particularly limited, but when a spectral sensitizing dye having crystal habit (plane) selectivity is used in the adsorption reaction of the sensitizing dye on the surface of the silver halide grain. It is preferable to use silver halide grains having a relatively high proportion of crystal habits adapted to the selectivity. For example, when using a sensitizing dye that is selectively adsorbed on the crystal face of the Miller index [100], the proportion of the [100] face on the outer surface of the silver halide grain is preferably high, and this ratio is 50 % Or more, more preferably 70% or more, and particularly preferably 80% or more. Conversely, when using a sensitizing dye that selectively adsorbs on the crystal face of the Miller index [111], it is preferable to increase the proportion of the [111] face on the outer surface of the silver halide grains. The ratio of the Miller index [100] plane is a T.K. based on the adsorption dependency of the [111] plane and the [100] plane in the adsorption of the sensitizing dye. Tani, J .; Imaging Sci. 29, 165 (1985).

  The silver halide grains used in the present invention are preferably prepared using low molecular weight gelatin having an average molecular weight of 50,000 or less at the time of grain formation, and particularly preferably used at the time of nucleation of silver halide grains. The low molecular weight gelatin has an average molecular weight of 50,000 or less, preferably 2000 to 40000, more preferably 5000 to 25000. The average molecular weight of gelatin can be measured by gel filtration chromatography.

  The concentration of the dispersion medium at the time of nucleation is preferably 5% by mass or less, and more effective at a low concentration of 0.05 to 3.0% by mass.

  As the silver halide grains used in the present invention, a polyethylene oxide compound represented by the following general formula [I] can be used at the time of grain formation.

Formula [I]
YO (CH ₂ CH ₂ O) _m (CH (CH ₃ ) CH ₂ O) _p (CH ₂ CH ₂ O) _n Y
In the formula, Y represents a hydrogen atom, —SO ₃ M, or —CO—B—COOM, and M represents an ammonium group substituted with a hydrogen atom, an alkali metal atom, an ammonium group, or an alkyl group having 5 or less carbon atoms. And B represents a chain or cyclic group forming an organic dibasic acid. m and n each represents 0 to 50, and p represents 1 to 100.

  The polyethylene oxide compound represented by the general formula [I] includes a step of producing an aqueous gelatin solution, a step of adding a water-soluble halide and a water-soluble silver salt to the gelatin solution, and a silver halide emulsion. Has been preferably used as an antifoaming agent for significant foaming when the emulsion raw material is stirred or moved, such as a step of coating on a support. The polyethylene oxide compound described in Japanese Utility Model Laid-Open No. 44-9497 and represented by the above general formula also functions as an antifoaming agent during nucleation.

  The polyethylene oxide compound represented by the above general formula [I] is preferably used at 1% by mass or less, more preferably 0.01 to 0.1% by mass with respect to silver.

  The polyethylene oxide compound represented by the above general formula [I] may be present at the time of nucleation and is preferably added in advance to the dispersion medium before nucleation. Alternatively, it may be added to a silver salt aqueous solution or a halide aqueous solution used at the time of nucleation. Preferably, it is used by adding 0.01 to 2.0% by mass to the aqueous halide solution or both aqueous solutions. Further, it is preferable to exist for at least 50% of the nucleation step, and more preferably for 70% or more. The polyethylene oxide compound represented by the above general formula may be added as a powder or dissolved in a solvent such as methanol.

  The temperature at the time of nucleation is 5 to 60 ° C., preferably 15 to 50 ° C. Even if the temperature is constant, the temperature rising pattern (for example, the temperature at the start of nucleation is 25 ° C. It is preferable to control the temperature within the above temperature range even when the temperature is gradually raised and the temperature at the end of nucleation is 40 ° C.) and vice versa.

The concentration of the silver salt aqueous solution and halide aqueous solution used for nucleation is preferably 3.5 mol / L or less, and more preferably used in a low concentration range of 0.01 to 2.5 mol / L. The addition rate of silver ions during nucleation is preferably 1.5 × 10 ^{−3 to} 3.0 × 10 ⁻¹ mol / min, more preferably 3.0 × 10 ^{−3 to} 8.0, per liter of reaction solution. × 10 ^-2 mol / min.

  The pH at the time of nucleation can be set in the range of 1.7 to 10, but the pH on the alkali side is preferably 2 to 6 in order to broaden the particle size distribution of nuclei to be formed. Moreover, pBr at the time of nucleation is about 0.05 to 3.0, preferably 1.0 to 2.5, and more preferably 1.5 to 2.0.

[Inner latent type silver halide grains after heat development]
As the photosensitive silver halide grains according to the present invention, silver halide grains whose surface sensitivity is lowered by converting from a surface latent image type to an internal latent image type by thermal development can be used. That is, in the exposure before thermal development, a latent image that can function as a catalyst for a development reaction (reduction reaction of silver ions by a silver ion reducing agent) is formed on the surface of the silver halide grains, and the exposure after the thermal development process has passed. Then, since many latent images are formed inside the surface of the silver halide grains, the silver halide grains are characterized in that the formation of latent images on the surface is suppressed.

  In general, when photosensitive silver halide grains are exposed, the silver halide grains themselves or spectral sensitizing dyes adsorbed on the surface of the photosensitive silver halide grains are photoexcited to freely move electrons. Although generated, the electrons are competitively trapped (captured) by an electron trap (photosensitive center) existing on the surface of the silver halide grain or an electron trap inside the grain. Therefore, if there are more chemical sensitization centers (chemical sensitization nuclei) and dopants effective as electron traps on the surface than the inside of the silver halide grains, a latent image is preferentially formed on the surface and development is possible. It becomes. On the contrary, when there are more chemical sensitization centers (chemical sensitization nuclei) and dopants effective as electron traps in the inside than the silver halide grain surface, a latent image is preferentially formed inside, and the surface Development becomes difficult. In other words, in the former case, the surface sensitivity is higher than the inside, and in the latter case, it can be said that the surface sensitivity is lower than the inside (reference: (1) TH James edited by “The Theory of the Photographic Process”. “Fourth Edition, Macmillan Publishing Co., Ltd. 1977, (2) The Japan Photographic Society,“ Revised Photographic Engineering Basics (Silver Salt Photography) ”, Corona, 1998).

  In the photosensitive silver halide grain according to the present invention, it is preferable in terms of sensitivity and image storage stability to contain a dopant functioning as an electron trapping dopant at least during exposure after heat development. .

  In addition, a dopant that functions as a hole trap during the exposure for image formation before heat development, changes in the heat development process, and functions as an electron trap after heat development, Particularly preferred.

  The electron trapping dopant used here is an element or compound other than silver and halogen constituting silver halide grains, and the dopant itself has a property of trapping (capturing) free electrons, or the dopant is halogen. It is the one in which a site such as an electron trapping lattice defect is generated by being contained in a silver halide grain. For example, metal ions other than silver or salts or complexes thereof, chalcogens (oxygen group elements) such as sulfur, selenium, tellurium, or inorganic compounds or organic compounds containing nitrogen atoms, or metal complexes thereof, rare earth ions or complexes thereof, etc. Can be mentioned.

  Examples of metal ions or salts or complexes thereof include lead ions, bismuth ions, gold ions, etc., or lead bromide, lead nitrate, lead carbonate, lead sulfate, bismuth nitrate, bismuth chloride, bismuth trichloride, bismuth carbonate, sodium bismutate, Examples include chloroauric acid, lead acetate, lead stearate, and bismuth acetate.

  As the compound containing a chalcogen such as sulfur, selenium or tellurium, various chalcogen-releasing compounds generally known as chalcogen sensitizers in the photographic industry can be used. Moreover, as an organic substance containing chalcogen or nitrogen, a heterocyclic compound is preferable. For example, imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, Tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, indolenine, tetrazaindene, preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, oxadiazole, quinoline, phthalazine, Naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, o Sasol, benzimidazole, benzoxazole, benzthiazole, a tetrazaindene.

  The above heterocyclic compound may have a substituent, and the alkyl group, alkenyl group, aryl group, alkoxy group, aryloxy group, acyloxy group, acyl group, alkoxycarbonyl group are preferable as the substituent. , Aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, sulfonyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, Sulfo group, carboxyl group, nitro group and heterocyclic group, more preferably alkyl group, aryl group, alkoxy group, aryloxy group, acyl group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonyl group Amino group, sulfamoyl group, carbamoyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, nitro group, heterocyclic group, more preferably alkyl group, aryl group, alkoxy group, aryloxy group, acyl group An acylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, a halogen atom, a cyano group, a nitro group, or a heterocyclic group.

  The silver halide grains used in the present invention include groups 6 to 11 in the periodic table so that they function as electron trapping dopants as described above or as hole trapping dopants. Transition metal ions belonging to the above may be contained by chemically adjusting the oxidation state of the metal with a ligand or the like. As the transition metal, W, Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, and Pt are preferable.

  In the present invention, the above various dopants may be used alone or in combination of two or more of the same or different compounds or complexes. However, at least one kind needs to function as an electron trapping dopant at the time of exposure after thermal development. These dopants may be introduced into the silver halide grains in any chemical form.

  In the present invention, an embodiment in which any one of Ir or Cu complex or salt is used alone is not preferable.

The preferable content of the dopant is preferably in the range of 1 × 10 ⁻⁹ to 10 mol, more preferably in the range of 1 × 10 ⁻⁸ to 1 × 10 ⁻¹ mol, with ^respect to 1 mol of silver. Furthermore, 1 * 10 ^{< -6} > ^-1 * 10 ^<-2> mol is preferable.

  However, since the optimum amount depends on the kind of dopant, the grain size and shape of the silver halide grains, and other environmental conditions, it is preferable to examine optimization of the dopant addition conditions according to these conditions.

  In the present invention, the transition metal complex or complex ion is preferably represented by the following general formula.

General formula [ML ₆ ] ^m
In the formula, M represents a transition metal selected from Group 6 to 11 elements of the periodic table, L represents a ligand, and m represents 0,-, 2-, 3-, or 4-. Specific examples of the ligand represented by L include halogen ions (for example, fluorine ion, chlorine ion, bromine ion, iodine ion), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aquo. Each ligand includes nitrosyl, thionitrosyl, and the like, preferably aco, nitrosyl, thionitrosyl, and the like. When an acoligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

  The compounds providing these metal ions or complex ions are preferably added during silver halide grain formation and incorporated into the silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, physical ripening In addition, it may be added at any stage before or after chemical sensitization, but it is particularly preferably added at the stage of nucleation, growth and physical ripening, and more preferably at the stage of nucleation and growth, Most preferably, it is added at the stage of nucleation. In addition, it may be divided and added several times, and can be uniformly contained in the silver halide grains. For example, JP-A-63-29603, JP-A-2-306236, 3 As described in JP-A Nos. 167545, 4-76534, 6-110146, 5-273683, etc., the particles can be contained with a distribution.

  These metal compounds can be added by dissolving in water or an appropriate organic solvent (for example, alcohols, ethers, glycols, ketones, esters, amides). A method in which an aqueous solution or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together is added to the water-soluble silver salt solution or water-soluble halide solution during particle formation, or the silver salt solution and the halide solution are mixed simultaneously. When adding a third aqueous solution, a method of preparing silver halide grains by a method of simultaneous mixing of three liquids, a method of introducing an aqueous solution of a required amount of a metal compound into a reaction vessel during grain formation, or a silver halide preparation There is a method of adding and dissolving another silver halide grain which has been previously doped with metal ions or complex ions. In particular, a method of adding an aqueous solution of a metal compound powder or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together is added to the water-soluble halide solution. When added to the particle surface, a required amount of an aqueous solution of a metal compound can be charged into the reaction vessel immediately after the formation of the particle, during or after physical ripening, or at the time of chemical ripening.

  In addition, a nonmetallic dopant can also be introduce | transduced inside a silver halide by the method similar to said metallic dopant.

  In the photosensitive material according to the present invention, whether or not the above dopant has an electron trapping property can be evaluated by a method generally used in the photographic industry as follows. That is, a silver halide emulsion comprising silver halide grains doped with the above-mentioned dopant or a decomposition product thereof in silver halide grains is subjected to a photoconductivity measurement by a microwave photoconductivity measurement method or the like, and the halogenation does not contain a dopant. It can be evaluated by measuring the degree of decrease in photoconduction based on a silver grain emulsion. Alternatively, it can be performed by a comparative experiment of the internal sensitivity and surface sensitivity of the silver halide grains.

  The silver halide grains of the present invention may be added to the photosensitive layer by any method. At this time, the silver halide grains are arranged so as to be close to a reducible silver source (aliphatic carboxylic acid silver salt). In order to obtain an imaging material with high sensitivity and high covering power (CP), it is preferable.

  The silver halide grains according to the present invention are prepared in advance and added to a solution for preparing the aliphatic carboxylate silver salt grains. Although the preparation process can be handled separately, and is most preferable in terms of production control, as described in British Patent 1,447,454, when preparing aliphatic carboxylic acid silver salt particles, such as halide ions By making a halogen component coexist with an aliphatic carboxylate silver salt-forming component and injecting silver ions into this, silver halide grains produced almost simultaneously with the production of aliphatic carboxylate silver salt particles can also be used in combination. . It is also possible to prepare a silver halide grain by allowing a halogen-containing compound to act on an aliphatic carboxylic acid silver salt and converting the aliphatic carboxylic acid silver salt, and use the grain together. That is, a silver halide-forming component is allowed to act on a solution or dispersion of an aliphatic carboxylic acid silver salt prepared in advance, or a sheet material containing the aliphatic carboxylic acid silver salt, so that a part of the aliphatic carboxylic acid silver salt is removed. It can also be converted to photosensitive silver halide.

  Examples of the silver halide grain forming component include inorganic halogen compounds, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. Specific examples thereof are US Pat. No. 4,009,039. No. 3,457,075, No. 4,003,749, British Patent No. 1,498,956 and JP-A-53-27027, No. 53-25420.

  You may use together the silver halide grain manufactured by converting a part of aliphatic carboxylic acid silver salt into the silver halide grain separately prepared as mentioned above.

  These silver halide grains are separately prepared silver halide grains, 0.001 to 0.7 mol per 1 mol of aliphatic carboxylic acid silver salt, and silver halide grains obtained by conversion of aliphatic carboxylic acid silver salt. Preferably it is used at 0.03-0.5 mol.

  Separately prepared photosensitive silver halide grains are desalted by a known desalting method such as noodle method, flocculation method, ultrafiltration method, electrodialysis method, etc. However, it can be used without desalting.

[Organic silver salt: non-photosensitive aliphatic carboxylic acid silver salt]
The organic silver salt according to the present invention is preferably a non-photosensitive aliphatic carboxylic acid silver salt. The organic silver salt is a reducible silver source, and is a long chain aliphatic carboxylic acid having 10 to 30 carbon atoms, preferably 15 to 25 carbon atoms. Silver salts of acids are preferred. Examples of suitable silver salts include the following.

  Examples thereof include silver salts such as gallic acid, succinic acid, behenic acid, stearic acid, arachidic acid, palmitic acid and lauric acid, and preferable silver salts include silver behenate, silver arachidate and silver stearate.

  In the present invention, it is preferable that two or more kinds of aliphatic carboxylic acid silver salts are mixed in order to improve developability and form a silver image having a high density and a high contrast. It is preferable to prepare by mixing a silver ion solution with an aromatic carboxylic acid mixture.

  On the other hand, from the viewpoint of the storage stability of the image after development, the melting point of the aliphatic carboxylic acid which is a raw material for the aliphatic carboxylate silver is 50 ° C or higher, preferably 60 ° C or higher. The content ratio is preferably 50% or more, preferably 70% or more, and more preferably 80% or more. From this viewpoint, specifically, it is preferable that the content of silver behenate is high.

  The aliphatic carboxylic acid silver salt is obtained by mixing a water-soluble silver compound and a compound that forms a complex with silver, and is described in Japanese Patent Application Laid-Open No. 9-127643. The controlled double jet method as described above is preferably used. For example, an alkali metal salt (eg, sodium hydroxide, potassium hydroxide, etc.) is added to an organic acid to produce an organic acid alkali metal salt soap (eg, sodium behenate, sodium arachidate), and then a controlled double jet. According to the method, the soap and silver nitrate are mixed to produce an aliphatic carboxylic acid silver salt crystal. At that time, seed crystal grains of silver aliphatic carboxylate, silver halide grains, and the like may be mixed.

  Examples of the alkali metal salt used in the present invention include sodium hydroxide, potassium hydroxide, and lithium hydroxide, but it is preferable to use sodium hydroxide and potassium hydroxide in combination. The combined ratio is preferably such that the molar ratio of both of the above-mentioned hydroxide salts is in the range of 10:90 to 75:25. When used in the above range when reacted with an aliphatic carboxylic acid to form an alkali metal salt of an aliphatic carboxylic acid, the viscosity of the reaction solution can be controlled in a good state.

  In addition, when preparing an aliphatic carboxylate silver salt in the presence of silver halide grains having an average particle diameter of 0.050 μm or less, the alkali metal of the alkali metal salt is preferably a halide having a higher potassium ratio. It is preferable because dissolution of silver particles and Ostwald ripening are prevented. Moreover, the size of fatty acid silver salt particle | grains can be made small, so that the ratio of potassium salt is high. A preferable ratio of the potassium salt is 50 to 100% based on the total alkali metal salt used in the step of producing the aliphatic carboxylate. The concentration of the alkali metal salt is preferably 0.1 to 0.3 mol / 1000 ml.

[Structure and shape of aliphatic carboxylic acid silver salt]
The aliphatic carboxylic acid silver salt according to the present invention may be a crystal particle having a core / shell structure as disclosed in European Patent 1168069A1 and Japanese Patent Application Laid-Open No. 2002-23303. In the case of a core / shell structure, all or part of either the core part or the shell part is an organic silver salt other than the aliphatic carboxylate silver, for example, silver of an organic compound such as phthalic acid or benzimidazole. A salt may be used as a constituent of the crystal particles.

  In the aliphatic carboxylic acid silver salt according to the present invention, the average equivalent circle diameter is preferably 0.05 μm or more and 0.8 μm or less, and the average thickness is preferably 0.005 μm or more and 0.07 μm or less. Particularly preferably, the average equivalent circle diameter is 0.2 μm or more and 0.5 μm or less, and the average thickness is 0.01 μm or more and 0.05 μm or less.

  When the average equivalent circle diameter is 0.05 μm or less, the transparency is excellent, but the image storage stability is poor, and when the average particle diameter is 0.8 μm or more, devitrification is severe. When the average thickness is 0.005 μm or less, the surface area is large, and silver ions are rapidly supplied during development. In particular, the low density area is not used for silver images, and there is a large amount of silver ions remaining in the film. The image storage stability is significantly deteriorated. On the other hand, when the average thickness is 0.07 μm or more, the surface area is reduced and the image stability is improved. However, the silver supply during development is slow, and the developed silver shape is uneven in the high density portion, resulting in the highest result. Concentration tends to be low.

  In order to obtain the average equivalent circle diameter, the dispersed aliphatic carboxylic acid silver salt is diluted and dispersed on a grid with a carbon support film, a transmission electron microscope (for example, JEOL Ltd., 2000FX type), direct magnification 5000 An image is taken at a magnification, a negative is captured as a digital image by a scanner, and 300 or more particle diameters (equivalent circle diameters) are measured using appropriate image processing software, and an average particle diameter can be calculated.

  The average thickness can be calculated by a method using a TEM (transmission electron microscope) as shown below.

  First, the photosensitive layer coated on the support is attached to an appropriate holder with an adhesive, and an ultrathin slice having a thickness of 0.1 to 0.2 μm is produced using a diamond knife in a direction perpendicular to the support surface. . The prepared ultra-thin slice is supported on a copper mesh, transferred onto a carbon film that has been hydrophilized by glow discharge, and cooled with liquid nitrogen to −130 ° C. or lower using a transmission electron microscope (hereinafter referred to as TEM). The bright field image is observed at a magnification of 5,000 to 40,000, and the image is quickly recorded on a film, an imaging plate, a CCD camera or the like. At this time, it is preferable to appropriately select a portion where the section is not torn or slack as the field of view to be observed.

  As the carbon film, it is preferable to use a film supported by an organic film such as a very thin collodion or form bar. More preferably, the carbon film is formed on a rock salt substrate and dissolved and removed. It is a carbon-only film obtained by removal by organic solvent and ion etching. The acceleration voltage of TEM is preferably 80 to 400 kV, particularly preferably 80 to 200 kV.

  In addition, for details of electron microscope observation techniques and sample preparation techniques, see “The Japan Electron Microscopy Society Kanto Branch / Medical and Biological Electron Microscopy” (Maruzen), “The Japan Electron Microscopy Society Kanto Branch / Electron Microscope Biological Samples” "Manufacturing method" (Maruzen) can be referred to respectively.

  A TEM image recorded on a suitable medium is preferably decomposed into at least 1024 pixels × 1024 pixels, preferably 2048 pixels × 2048 pixels or more, and image processing by a computer is performed. In order to perform image processing, it is preferable that an analog image recorded on a film is converted into a digital image by a scanner or the like, and shading correction, contrast / edge enhancement, and the like are performed as necessary. Thereafter, a histogram is prepared, and a portion corresponding to the aliphatic carboxylate silver is extracted by binarization processing.

  The thickness of the extracted aliphatic carboxylic acid silver salt particles is manually measured with an appropriate software of 300 or more, and an average value is obtained.

  The method for obtaining the aliphatic carboxylic acid silver salt particles having the above-mentioned shape is not particularly limited. For example, the mixed state at the time of forming the organic acid alkali metal salt soap or the mixed state at the time of adding silver nitrate to the soap. It is effective to keep it good, and to set the ratio of the organic acid to the soap and the ratio of the silver nitrate that reacts with the soap optimally.

  In the present invention, tabular aliphatic carboxylic acid silver salt particles (aliphatic carboxylic acid having an average equivalent circle diameter of 0.05 μm to 0.8 μm and an average thickness of 0.005 μm to 0.07 μm) The acid silver salt particles) are preferably pre-dispersed with a binder, a surfactant or the like, if necessary, and then dispersed and ground with a media disperser or a high-pressure homogenizer. As the preliminary dispersion method, for example, a general stirrer such as an anchor type or a propeller type, a high speed rotary centrifugal radiation type stirrer (dissolver), or a high speed rotary shear type stirrer (homomixer) can be used.

  Further, as the media disperser, for example, a rolling mill such as a ball mill, a planetary ball mill, a vibrating ball mill, a bead mill that is a medium agitation mill, an attritor, and other basket mills can be used, and as a high-pressure homogenizer Various types can be used, such as a type that collides with a wall, a plug, etc., a type in which liquids are collided with each other at high speed, and a type through which a thin orifice is passed.

  Ceramics used for the ceramic beads used when dispersing media include yttrium-stabilized zirconia and zirconia-reinforced alumina (ceramics containing these zirconia) because of the low generation of impurities due to friction with the beads and the dispersing machine during dispersion. Is abbreviated as zirconia in the following).

  In the apparatus used for dispersing the tabular aliphatic carboxylate silver salt particles according to the present invention, examples of the material of the member in contact with the aliphatic carboxylate silver salt particles include zirconia, alumina, silicon nitride, and boron nitride. It is preferable to use ceramics such as the above or diamond, and it is preferable to use zirconia. When the above dispersion is performed, the binder concentration is preferably added in an amount of 0.1 to 10% of the mass of the aliphatic silver carboxylate, and it is preferable that the liquid temperature does not exceed 45 ° C. from the preliminary dispersion through the main dispersion. As preferable operating conditions for this dispersion, for example, when a high-pressure homogenizer is used as the dispersing means, 29 to 100 MPa, and the number of operations is preferably 2 or more. Moreover, when using a media disperser as a dispersion | distribution means, a peripheral speed of 6-13 m / sec is mentioned as preferable conditions.

  In the present invention, the non-photosensitive aliphatic carboxylic acid silver salt particles are preferably formed in the presence of a compound that functions as a crystal growth inhibitor or a dispersant. Moreover, it is preferable that the compound which functions as a crystal growth inhibitor or a dispersing agent is an organic compound having a hydroxyl group or a carboxyl group.

  In the present invention, the compound that functions as a crystal growth inhibitor or dispersant for the aliphatic carboxylate silver particles refers to a silver aliphatic carboxylate under the conditions in which the compound coexists in the production process of the aliphatic carboxylate particles. A compound having a function and an effect of reducing the particle size or monodispersing than when it is produced under conditions that do not coexist. Specific examples include monohydric alcohols having 10 or less carbon atoms, preferably secondary alcohols, tertiary alcohols, glycols such as ethylene glycol and propylene glycol, polyethers such as polyethylene glycol, and glycerin. A preferable addition amount is 10 to 200% by mass with respect to the aliphatic carboxylate silver.

  On the other hand, branched aliphatic carboxylic acids containing isomers such as isoheptanoic acid, isodecanoic acid, isotridecanoic acid, isomyristic acid, isopalmitic acid, isostearic acid, isoarachidic acid, isobehenic acid and isohexaconic acid are also preferred. In this case, a preferable side chain includes an alkyl group or an alkenyl group having 4 or less carbon atoms. In addition, aliphatic unsaturated carboxylic acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, moloctic acid, eicosenoic acid, arachidonic acid, eicosapentaenoic acid, erucic acid, docosapentaenoic acid, docosahexaenoic acid, and ceracolonic acid It is done. A preferable addition amount is 0.5 to 10 mol% of the silver aliphatic carboxylate.

  Glycosides such as glucoside, galactoside and fructoside, trehalose type disaccharides such as trehalose and sucrose, polysaccharides such as glycogen, dextrin, dextran and alginic acid, cellosolves such as methyl cellosolve and ethyl cellosolve, sorbitan, sorbit, ethyl acetate and acetic acid Water-soluble organic solvents such as methyl and dimethylformamide, water-soluble polymers such as polyvinyl alcohol, polyacrylic acid, acrylic acid copolymer, maleic acid copolymer, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylpyrrolidone and gelatin Are also preferred compounds. A preferable addition amount is 0.1 to 20% by mass with respect to the aliphatic carboxylate silver.

  Alcohols having 10 or less carbon atoms, preferably secondary alcohols such as isopropyl alcohol and tertiary alcohols such as t-butyl alcohol are used to increase the solubility of the alkali metal salt of aliphatic carboxylic acid in the particle production process. By reducing the viscosity and increasing the stirring efficiency, it is monodispersed and the particle size is reduced. Branched aliphatic carboxylic acids and aliphatic unsaturated carboxylic acids have higher steric hindrance than the main component linear aliphatic carboxylic acid silver when crystallization of the aliphatic carboxylic acid silver, and the disorder of the crystal lattice is large. Therefore, large crystals are not generated, and as a result, the particle size is reduced.

[Anti-foggant and image stabilizer]
The antifogging and image stabilizer used in the silver salt photothermographic dry imaging material of the present invention will be specifically described.

  In the silver salt photothermographic dry imaging material of the present invention, the organic silver salt is obtained by inactivating the compound that generates a reactive species capable of oxidizing silver or the reducing agent by exposure to ultraviolet light or visible light. It is preferable to contain two or more compounds that generate reactive species capable of preventing the silver ions from being reduced to silver.

  In the silver salt photothermographic dry imaging material of the present invention, as a silver ion reducing agent, it is preferable to mainly use bisphenols, as described later, under the storage conditions before development of the imaging material, and It is preferred that a compound capable of inactivating the reducing agent is contained under the storage conditions after heat development. Preferably, a compound that can prevent the phenoxyl radical from being generated from the reducing agent or a compound that can trap the generated phenoxyl radical and stabilize it so that it does not function as a silver ion reducing agent. Is preferred. Suitable compounds having such functions and functions include non-reducing compounds having a group capable of forming a hydrogen bond with the hydroxyl group of bisphenols, such as phosphoryl group, sulfoxide group, sulfonyl group, carbonyl group, amide And compounds having a group, an ester group, a urethane group, a ureido group, a tertiary amino group, a nitrogen-containing aromatic group, and the like. Particularly preferred are compounds having a sulfonyl group, a sulfoxide group, or a phosphoryl group. Specific examples are disclosed in JP-A-6-208192, JP-A-2001-215648, JP-A-350235, JP-A-2002-6444, JP-A-2002-18264, and the like. Further, specific compounds having a vinyl group are disclosed in JP-T-2000-515995, JP-A-2002-207273, JP-A-2003-140298, and the like.

  Also used in combination with compounds that can oxidize silver (metal silver), for example, compounds that can oxidize silver by releasing an oxidizing halogen radical or interacting with silver to form a charge transfer complex can do. Specific examples of compounds having such functions include JP-A-50-120328, JP-A-59-57234, JP-A-4-232939, JP-A-6-208193, JP-A-10-197989, and the United States. Japanese Patent No. 5,460,938, Japanese Patent Laid-Open No. 7-2781, and the like. In particular, in the imaging material according to the present invention, specific examples of preferable compounds include halogen radical releasing compounds that can be represented by the following general formula (OFI).

General formula (OFI)
_{Q 2 -Y-C (X 1} ) (X 3) (X 2)
In general formula (OFI), Q ₂ represents an aryl group or a heterocyclic group. X ₁ , X ₂ and X ₃ each represent a hydrogen atom, a halogen atom, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group or an aryl group, at least one of which is a halogen atom. Y represents —C (═O) —, —SO— or —SO ₂ —.

The aryl group represented by Q ₂ may be monocyclic or condensed, and is preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms (for example, phenyl, naphthyl, etc.), more preferably Is a phenyl group or a naphthyl group, more preferably a phenyl group.

The heterocyclic group represented by Q ₂ is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one atom of N, O or S, which may be monocyclic, Furthermore, you may form a condensed ring with another ring.

  The heterocyclic group is preferably a 5- to 6-membered unsaturated heterocyclic group which may have a condensed ring, more preferably a 5- to 6-membered aromatic heterocyclic ring which may have a condensed ring. It is a group. More preferably, it is a 5- to 6-membered aromatic heterocyclic group which may have a condensed ring containing a nitrogen atom, and particularly preferably a condensed ring containing 1 to 4 nitrogen atoms. A 6-membered aromatic heterocyclic group. The heterocyclic ring in such a heterocyclic group is preferably imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline Cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, indolenine, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, Triazine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinoaline Zolin, cinnoline, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, quinoline, phthalazine, naphthyridine, Quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, benzimidazole, and benzthiazole are preferable, and pyridine, thiadiazole, quinoline, and benzthiazole are particularly preferable.

The aryl group and heterocyclic group represented by Q ₂ may have a substituent in addition to —Y—C (X ₁ ) (X ₂ ) (X ₃ ), and the substituent is preferably an alkyl group, Alkenyl group, aryl group, alkoxy group, aryloxy group, acyloxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl Group, carbamoyl group, sulfonyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, sulfo group, carboxyl group, nitro group, heterocyclic group, more preferably alkyl group, aryl group, alkoxy group, aryl Oxy group, acyl group, acylamino group, alkoxycarbonylamino , Aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, nitro group, heterocyclic group, more preferably alkyl group, aryl group, alkoxy group Group, aryloxy group, acyl group, acylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, halogen atom, cyano group, nitro group, heterocyclic group, particularly preferably alkyl group, aryl group, halogen atom .

X ₁ , X ₂ and X ₃ are preferably a halogen atom, haloalkyl group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, sulfamoyl group, sulfonyl group or heterocyclic group, more preferably a halogen atom , A haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group and a sulfonyl group, more preferably a halogen atom and a trihalomethyl group, and particularly preferably a halogen atom. Of the halogen atoms, preferred are a chlorine atom, a bromine atom and an iodine atom, more preferred are a chlorine atom and a bromine atom, and particularly preferred is a bromine atom.

Y represents —C (═O) —, —SO— or —SO ₂ —, preferably —SO ₂ —.

The amount of these compounds added can be 1 × 10 ⁻⁴ to 1 mol, preferably 1 × 10 ^{−3 to} 5 × 10 ⁻² mol, per mol of silver.

  In addition, in the imaging material which concerns on this invention, it can use similarly to the compound which is disclosed by Unexamined-Japanese-Patent No. 2003-5041 and can be represented by said general formula (OFI).

  Specific examples of the compound represented by the general formula (OFI) are shown below, but the present invention is not limited thereto.

[Polymer PO inhibitor]
Furthermore, in the imaging material according to the present invention, it is possible to use, as an image stabilizer, a polymer having at least one repeating unit of a monomer having a halogen radical releasing group as disclosed in JP-A No. 2003-91054. In addition to further stabilizing the silver image, it is also preferable from the viewpoint of high sensitivity and high CP. In particular, the photothermographic imaging material according to the present invention provides unexpectedly good results.

  Specific examples of the polymer having a halogen radical releasing group are shown below, but the present invention is not limited thereto.

  In addition to the above compound, the silver salt photothermographic dry imaging material of the present invention may contain a compound conventionally known as an antifoggant. For example, U.S. Pat. Nos. 3,589,903, 4,546,075, 4,452,885, JP-A-59-57234, U.S. Pat. No. 3,874,946, No. 4,756,999, JP-A-9-288328 and JP-A-9-90550. Further, other antifoggants include compounds disclosed in US Pat. No. 5,028,523 and European Patents 600,587, 605,981, and 631,176. .

[Polycarboxyl compound]
In the imaging material according to the present invention, it is also preferable to use a compound represented by the following general formula (PC) as an antifoggant and a storage stabilizer for the material.

General formula (PC)
R- (CO-OM) _n
In the formula, R represents an atom, an aliphatic group, an aromatic group, a heterocyclic group, or an atomic group that can be bonded to each other to form a ring. M represents a hydrogen atom, a metal atom, a quaternary ammonium group or a phosphonium group. n represents an integer of 2 to 20.

  In the general formula (PC), examples of the connectable atom represented by R include atoms such as nitrogen, oxygen, sulfur, and phosphorus.

  Examples of the aliphatic group represented by R include a linear or branched alkyl, alkenyl, alkynyl or cycloalkyl group having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. Specifically, for example, methyl, ethyl, propyl, butyl, hexyl, decyl, dodecyl, isopropyl, t-butyl, 2-ethylhexyl, allyl, 2-butenyl, 7-octenyl, propargyl, 2-butynyl, cyclopropyl, cyclopentyl , Cyclohexyl, cyclododecyl and the like.

  Examples of the aromatic group represented by R include those having 6 to 20 carbon atoms, and specific examples thereof include phenyl, naphthyl, and anthranyl groups.

  The heterocyclic group represented by R may be a monocyclic ring or a condensed ring, and includes a 5- to 6-membered heterocyclic group having at least one of O, S, and N atoms and an amine oxide group in the ring. . Specifically, for example, pyrrolidine, piperidine, tetrahydrofuran, tetrahydropyran, oxirane, morpholine, thiomorpholine, thiopyran, tetrahydrothiophene, pyrrole, pyridine, furan, thiophene, imidazole, pyrazole, oxazole, thiazole, isoxazole, isothiazole, triazole, And groups derived from tetrazole, thiadiazole, oxadiazole, and these benzerogues.

If R is formed by R ₁ and R _2, R ₁ and R ₂ have the same meanings as R, and, R ₁ is may be the same as or different from R _2. Examples of the ring forming with R ₁ and R ₂ include a 4- to 7-membered ring. Preferably it is a 5-7 membered ring. Preferred groups for R ₁ and R ₂ are aromatic groups and heterocyclic groups. The aliphatic group, aromatic group or heterocyclic group represented by R ₁ and R ₂ may be further substituted with a substituent, such as a halogen atom (for example, a chlorine atom, a bromine atom, etc.), An alkyl group (eg, a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trifluoromethyl group, a t-butyl group), a cycloalkyl group (eg, a cyclopentyl group, a cyclohexyl group, etc.), an aralkyl group (For example, benzyl group, 2-phenethyl group, etc.), aryl group (for example, phenyl group, naphthyl group, p-tolyl group, p-chlorophenyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, isopropoxy group) , Butoxy group etc.), aryloxy group (eg phenoxy group, 4-methoxyphenoxy group etc.), cyano group, acylamido Group (for example, acetylamino group, propionylamino group, etc.), alkylthio group (for example, methylthio group, ethylthio group, butylthio group, etc.), arylthio group (for example, phenylthio group, p-methylphenylthio group, etc.), sulfonylamino Group (for example, methanesulfonylamino group, benzenesulfonylamino group, etc.), ureido group (for example, 3-methylureido group, 3,3-dimethylureido group, 1,3-dimethylureido group, etc.), sulfamoylamino group (Eg, dimethylsulfamoylamino group, diethylsulfamoylamino group, etc.), carbamoyl group (eg, methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.), sulfamoyl group (eg, ethylsulfamoyl group, dimethyl) Sulfamoyl group, etc.), al Xyloxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenoxycarbonyl group, p-chlorophenoxycarbonyl group, etc.), sulfonyl group (eg, methanesulfonyl group, butanesulfonyl group, phenyl) Sulfonyl group etc.), acyl group (eg acetyl group, propanoyl group, butyroyl group etc.), amino group (eg methylamino group, ethylamino group, dimethylamino group etc.), hydroxy group, nitro group, nitroso group, amine Oxide group (for example, pyridine-oxide group, etc.), imide group (for example, phthalimide group, etc.), disulfide group (for example, benzene disulfide group, benzthiazolyl-2-disulfide group, etc.), heterocyclic group (for example, pyridyl group, benzine) Imidazolyl group Benzothiazolyl group, benzoxazolyl group). R ₁ and R ₂ may have one or more of these substituents. Further, each substituent may be further substituted with the above-described substituent. R ₁ and R ₂ may be the same or different. The general formula (PC-1) is also effective as an oligomer or polymer (R- (COOM) _n0 ) _m . n is 2 to 20, and m is preferably 1 to 100 or a molecular weight of 50000 or less.

  The acid anhydride of the general formula (PC-1) refers to a compound formed by a dehydration reaction from two carboxyl groups of the compound represented by the general formula (PC-1). Preferably, a compound having 3 to 10 carboxyl groups and an acid anhydride as a derivative thereof are preferable.

  JP-A-58-95338, JP-A-10-288824, JP-A-11-174621, JP-A-11-218877, JP-A-2000-10237, JP-A-2000-10236, JP-A-2000-10235, 2000-2000. The dicarboxylic acids described in Nos. -10233, 2000-10232, and 2000-10231 can be preferably used in combination.

[Thiosulfonic acid inhibitors]
The imaging material according to the present invention preferably contains a compound represented by the following general formula (ST).

General formula (ST)
Z-SO ₂ / SM
In the formula, Z represents a substituted or unsubstituted alkyl group, aryl group or heterocyclic group, and M represents a metal atom or an organic cation.

  In the compound represented by the general formula (ST), the alkyl group, aryl group, heterocyclic group, aromatic ring and heterocyclic ring represented by Z may be substituted. Examples of the substituent include a lower alkyl group such as a methyl group and an ethyl group, an aryl group such as a phenyl group, an alkoxyl group having 1 to 8 carbon atoms, a halogen atom such as chlorine, a nitro group, an amino group, and a carboxyl group. be able to. Examples of the heterocycle represented by Z include thiazole, benzthiazole, imidazole, benzimidazole, and oxazole ring. The metal atom represented by M is preferably an alkali metal atom such as sodium ion or potassium ion, and the organic cation is preferably an ammonium ion or a guanidine group.

  Specific examples of the compound represented by the general formula (ST) include the following, but the present invention is not limited thereto.

  The compound represented by the general formula (ST) can be synthesized by a generally well-known method. For example, it can be synthesized by reacting the corresponding sulfonyl fluoride and sodium sulfide, or reacting the corresponding sodium sulfinate and sulfur. On the other hand, these compounds can also be easily obtained as commercial products.

  The compound represented by the general formula (ST) may be added at any point in the process before the coating process in the manufacturing process of the imaging material according to the present invention, but is preferably added to the coating liquid immediately before coating. .

The amount of the compound represented by the general formula (ST) is not particularly limited, but is preferably in the range of 1 × 10 ^{−6 to} 1 g per mole of total silver including the organic silver salt and the silver halide. Similar compounds are disclosed in JP-A-8-314059.

[Vinyl type inhibitor having electron withdrawing group]
In this invention, it is preferable to use together the fog inhibitor which can be represented by the following general formula (CV).

  In the above general formula (CV), the electron withdrawing group represented by X is a substituent whose Hammett's substituent constant σp can take a positive value. Specifically, a substituted alkyl group (such as halogen-substituted alkyl), a substituted alkenyl group (such as cyanovinyl), a substituted or unsubstituted alkynyl group (such as trifluoromethylacetylenyl, cyanoacetylenyl, formylacetylenyl), Substituted aryl groups (such as cyanophenyl), substituted and unsubstituted heterocyclic groups (such as pyridyl, triazinyl, benzoxazolyl), halogen atoms, cyano groups, acyl groups (such as acetyl and trifluoroacetyl), thioacyl groups (such as thioformyl) , Thioacetyl etc.), oxalyl group (methyl oxalyl etc.), oxyoxalyl group (ethoxalyl etc.), -S-oxalyl group (ethylthiooxalyl etc.), oxamoyl group (methyl oxamoyl etc.), oxycarbonyl group (ethoxycarbonyl, carboxyl Etc.), -S-carbonyl group (ethyl) Ocarbonyl), carbamoyl group, thiocarbamoyl group, sulfonyl group, sulfinyl group, oxysulfonyl group (ethoxysulfonyl etc.), -S-sulfonyl group (ethylthiosulfonyl etc.), sulfamoyl group, oxysulfinyl group (methoxysulfinyl etc.) , -S-sulfinyl group (such as methylthiosulfinyl group), sulfinamoyl group, phosphoryl group, nitro group, imino group (imino, N-methylimino, N-phenylimino, N-pyridylimino, N-cyanoimino, N-nitroimino, etc.), N -Carbonylimino group (N-acetylimino, N-ethoxycarbonylimino, N-ethoxalylimino, N-formylimino, N-trifluoroacetylimino, N-carbamoylimino, etc.), N-sulfonylimino group (N-methanes) Phonylimino, N-trifluoromethanesulfonylimino, N-methoxysulfonylimino, N-sulfamoylimino, etc.), ammonium group, sulfonium group, phosphonium group, pyrylium group, immonium group, etc., ammonium group, sulfonium group In addition, a heterocyclic group in which a phosphonium group, an immonium group or the like forms a ring is also included. However, X excludes a formyl group. The σp value is preferably 0.2 or more, and more preferably 0.3 or more.

  W includes hydrogen atom, alkyl group (methyl, ethyl, trifluoromethyl, etc.) alkenyl group (vinyl, halogen-substituted vinyl, cyanovinyl, etc.), alkynyl group (acetylenyl, cyanoacetylenyl, etc.), aryl group (phenyl, chlorophenyl) , Nitrophenyl, cyanophenyl, pentafluorophenyl, etc.), heterocyclic groups (pyridyl, pyrimidyl, pyrazinyl, quinoxalinyl, triazinyl, succinimide, tetrazolyl, triazolyl, imidazolyl, benzoxazolyl, etc.) Halogen atom, cyano group, acyl group, thioacyl group, oxalyl group, oxyoxalyl group, -S-oxalyl group, oxamoyl group, oxycarbonyl group, -S-carbonyl group, carbamoyl group, thiocarbamoyl group, sulfonyl , Sulfinyl group, oxysulfonyl group, -S-sulfonyl group, sulfamoyl group, oxysulfinyl group, -S-sulfinyl group, sulfinamoyl group, phosphoryl group, nitro group, imino group, N-carbonylimino group, N-sulfonylimino group , Ammonium group, sulfonium group, phosphonium group, pyrylium group, immonium group and the like. However, the formyl group is excluded as W.

  W is preferably an electron withdrawing group other than a formyl group in which Hammett's substituent constant σp can take a positive value, as well as an aryl group and a heterocyclic group as described above.

  X and W may be bonded to each other to form a cyclic structure. Examples of the ring formed by X and W include a saturated or unsaturated carbocycle or heterocycle which may have a condensed ring, and may be a cyclic ketone. As the heterocyclic ring, those containing at least one atom, more preferably 1-2, of N, O and S are preferable.

R ₁ includes a hydroxyl group or an organic or inorganic salt of a hydroxyl group. Specific examples of the alkyl group, alkenyl group, alkynyl group, aryl group and heterocyclic group represented by R ₂ include the examples of the alkyl group, alkenyl group, alkynyl group, aryl group and heterocyclic group exemplified as W. It is done.

In the present invention, X, W and R ₂ may all contain a diffusion-resistant group. The anti-diffusion group is called a ballast group in a photographic coupler or the like, and has a bulky molecular weight so that the added compound does not move in the film of the photosensitive material.

In the present invention, X, W and R ₂ may contain an adsorption promoting group for silver salt. Adsorption promoting groups for silver salts include thioamide groups, aliphatic mercapto groups, aromatic mercapto groups, heterocyclic mercapto groups and benzotriazoles, triazoles, tetrazoles, indazoles, benzimidazoles, imidazoles, benzothiazoles, thiazoles, benzoxazoles, Examples include groups represented by 5- to 6-membered nitrogen-containing heterocycles such as oxazole, thiadiazole, oxadiazole, and triazine.

  In the present invention, it is preferable that at least one of X and W represents a cyano group, or X and W are bonded to each other to form a cyclic structure.

In the present invention, a compound containing a thioether group (—S—) in the substituent represented by X, W, or R ₂ is preferable.

  Further, among X and W, those having at least one alkene group represented by the following general formula (CV1) are particularly preferred.

Formula (CV1) -C (R) = C (Y) (Z)
In the above formula, R represents a hydrogen atom or a substituent, and Y and Z each represent a hydrogen atom or a substituent, and at least one of Y and Z represents an electron-withdrawing group.

  Examples of the electron-withdrawing group among the substituents represented by Y and Z include those mentioned as the electron-withdrawing groups for X and W described above and the formyl group.

  Examples of X and W represented by the general formula (CV1) include the following groups.

  Further, it is also preferable that at least one of X and W has the following alkyne group.

R ₅ represents a hydrogen atom or a substituent, and the substituent is preferably an electron-withdrawing group as exemplified in X and W described above. Examples of X and W represented by the general formula (CV1) include the following groups.

  In addition, among X and W, those having at least one acyl group selected from a substituted alkylcarbonyl group, an alkenylcarbonyl group, and an alkynylcarbonyl group are also preferred. Examples of X and W include the following groups.

  Moreover, what has at least one oxalyl group among X and W is also preferable, and the following groups are mentioned as X and W which have an oxalyl group, for example.

_{And, -COCOCH 3, -COCOOC 2 H 5} , -COCONHCH 3, -COCOSC 2 H 5, -COCOOC 2 H 4 SCH 3, -COCONHC 2 H 4 SCH 3.

  In addition, it is preferable that at least one of X and W has an aryl group substituted with an electron-withdrawing group or a nitrogen-containing heterocyclic group. Examples of such X and W include the following groups.

In the present invention, the alkene compound represented by the general formula (CV) includes all isomers when it can take an isomer structure with respect to the double bond substituted by X, W, R ₁ and R ₂ . In addition, all isomers are included when a tautomeric structure such as ketoeenol can be taken.

  Specific examples of the compound represented by the general formula (CV) are shown below, but the present invention is not limited thereto.

  The compound represented by the general formula (CV) of the present invention can be synthesized by various methods. For example, the compound can be synthesized with reference to the synthesis method described in JP-T 2000-515995.

  Illustrative compound CV-5 can be synthesized, for example, by the following route.

The compound represented by the general formula (CV) may be contained in at least one of the photosensitive layer of the photothermographic material or the non-photosensitive layer on the photosensitive layer side, and preferably contained in at least the photosensitive layer. is there. The amount of the compound represented by the general formula (1) is preferably 1 × 10 ⁻⁸ to 1 mol, more preferably 1 × 10 ⁻⁶ to 1 × 10 ⁻¹ mol, relative to 1 mol of silver, 1 ×. 10 ⁻⁴ to 1 × 10 ⁻² mol is most preferred.

  The compound represented by formula (CV) can be added to the photosensitive layer or the non-photosensitive layer according to a known method. That is, it can be dissolved in an alcohol such as methanol or ethanol, a ketone such as methyl ethyl ketone or acetone, or a polar solvent such as dimethyl sulfoxide or dimethylformamide, and added to the coating solution for the photosensitive layer or the non-photosensitive layer. Further, fine particles of 1 μm or less can be dispersed and added in water or an organic solvent. Many techniques for fine particle dispersion are disclosed, but they can be dispersed according to these techniques.

[Silver ion reducing agent]
In the present invention, US Pat. Nos. 3,589,903, 4,021,249 or British Patent 1,486,148 are used as silver ion reducing agents (sometimes referred to simply as reducing agents). And polyphenol compounds described in JP-A-51-51933, JP-A-50-36110, JP-A-50-116023, JP-A-52-84727 or JP-B-51-35727, such as 2,2′-dihydroxy- Bisnaphthols described in US Pat. No. 3,672,904 such as 1,1′-binaphthyl, 6,6′-dibromo-2,2′-dihydroxy-1,1′-binaphthyl, For example, 4-benzenesulfonamidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4-benzenesulfonamidophenol , It can be used sulfonamidophenols or sulfonamidonaphthols, such as described in U.S. Patent No. 3,801,321, such as 4-benzenesulfonamide naphthol.

  However, in the present invention, the silver ion reducing agent is preferably a compound represented by the following general formula (RED).

In the formula, X ₁ represents a chalcogen atom or CHR ₁ , and R ₁ represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. R ₂ represents an alkyl group. R ₃ represents a hydrogen atom or a group that can be substituted on a benzene ring. R ₄ represents a substitutable group on the benzene ring, and m and n each represents an integer of 0 to 2.

In the general formula (RED), X ₁ represents a chalcogen atom or CHR ₁ . The chalcogen atom is sulfur, selenium or tellurium, preferably a sulfur atom. CHR R ₁ in ₁ represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, the alkyl group substituted or An unsubstituted alkyl group having 1 to 20 carbon atoms is preferred. Specific examples include methyl, ethyl, propyl, butyl, hexyl, heptyl, cycloalkyl, etc. Examples of the alkenyl group include vinyl, allyl, butenyl, hexenyl, hexadienyl, ethenyl-2-propenyl, 3-butenyl, 1-methyl- 3-propenyl, 3-pentenyl, 1-methyl-3-butenyl, cyclohexenyl, etc., aryl groups such as benzene ring, naphthalene ring, etc., heterocyclic groups such as thiophene, furan, imidazole, pyrazole, pyrrole, etc. is there. In particular, a cyclic group such as a cycloalkyl group and a cycloalkenyl group is preferable.

  These groups may further have a substituent. Specific examples of the substituent include a halogen atom (fluorine, chlorine, bromine, etc.), an alkyl group (methyl, ethyl, propyl, butyl, pentyl, i-pentyl). , 2-ethylhexyl, octyl, decyl, etc.), cycloalkyl groups (cyclohexyl, cycloheptyl, etc.), alkenyl groups (ethenyl-2-propenyl, 3-butenyl, 1-methyl-3-propenyl, 3-pentenyl, 1-methyl) -3-butenyl, etc.), cycloalkenyl groups (1-cycloalkenyl, 2-cycloalkenyl groups, etc.), alkynyl groups (ethynyl, 1-propynyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy, etc.), alkylcarbonyloxy groups (Acetyloxy, etc.), alkylthio groups (methylthio, trifluoromethylthio, etc.), potassium Boxyl group, alkylcarbonylamino group (acetylamino etc.), ureido group (methylaminocarbonylamino etc.), alkylsulfonylamino group (methanesulfonylamino etc.), alkylsulfonyl group (methanesulfonyl, trifluoromethanesulfonyl etc.), carbamoyl group ( Carbamoyl, N, N-dimethylcarbamoyl, N-morpholinocarbonyl, etc.), sulfamoyl group (sulfamoyl, N, N-dimethylsulfamoyl, morpholinosulfamoyl etc.), trifluoromethyl group, hydroxyl group, nitro group, cyano group Alkylsulfonamide groups (methanesulfonamide, butanesulfonamide, etc.), alkylamino groups (amino, N, N-dimethylamino, N, N-diethylamino, etc.), sulfo groups, phosphono groups, sulfite Group, sulfino group, alkylsulfonylaminocarbonyl group (methanesulfonylaminocarbonyl, ethanesulfonylaminocarbonyl etc.), alkylcarbonylaminosulfonyl group (acetamidosulfonyl, methoxyacetamidosulfonyl etc.), alkynylaminocarbonyl group (acetamidocarbonyl, methoxyacetamidocarbonyl etc.) ), Alkylsulfinylaminocarbonyl groups (methanesulfinylaminocarbonyl, ethanesulfinylaminocarbonyl, etc.) and the like. Moreover, when there are two or more substituents, they may be the same or different.

  A particularly preferred substituent is an alkyl group.

R ₂ represents an alkyl group. The alkyl group is preferably a substituted or unsubstituted one having 1 to 20 carbon atoms, specifically, methyl, ethyl, propyl, i-propyl, butyl, i-butyl, t-butyl, t-pentyl, t-octyl. , Cyclohexyl, cyclopentyl, 1-methylcyclohexyl, 1-methylcyclopropyl and the like.

Although the substituent of the alkyl group is not particularly limited, for example, aryl group, hydroxyl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acylamino group, sulfonamido group, sulfonyl group, phosphoryl group, acyl group, carbamoyl group, An ester group, a halogen atom, etc. are mentioned. Or it may form a saturated ring with (R _{4) n} and (R _{4) m.} R ₂ is preferably a secondary or tertiary alkyl group, and preferably has 2 to 20 carbon atoms. A tertiary alkyl group is more preferred, t-butyl, t-pentyl and 1-methylcyclohexyl are more preferred, and t-butyl is most preferred.

R ₃ represents a hydrogen atom or a group that can be substituted on the benzene ring. Examples of the group that can be substituted on the benzene ring include halogen atoms such as fluorine, chlorine, bromine, alkyl groups, aryl groups, cycloalkyl groups, alkenyl groups, cycloalkenyl groups, alkynyl groups, amino groups, acyl groups, acyloxy groups, Examples include acylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, sulfonyl group, alkylsulfonyl group, sulfinyl group, cyano group, and heterocyclic group.

R ₃ is preferably methyl, ethyl, i-propyl, t-butyl, cyclohexyl, 1-methylcyclohexyl, 2-hydroxyethyl and the like. More preferred are methyl and 2-hydroxyethyl.

These groups may further have a substituent, and the substituents exemplified in the above R ₁ can be used as the substituent.

R ₃ is more preferably an alkyl group having 1 to 10 carbon atoms. In particular, a hydroxyl group as disclosed in Japanese Patent Application No. 2002-120842, or an alkyl group having a group capable of forming a hydroxyl group by deprotection as a substituent, such as a 2-hydroxyethyl group, etc. It is done. Such a reducing agent having an alkyl group should be used alone in order to obtain a high maximum density (Dmax) with a constant applied silver amount, that is, a silver image density with a high silver coverage (covering power, CP). Or it is preferable to use together with another reducing agent.

The most preferred combination of R ₂ and R ₃ is that R ₂ is a tertiary alkyl group (t-butyl, 1-methylcyclohexyl, etc.), R ₃ is an alkyl group, and is a hydroxyl group or deprotected. An alkyl group having a group capable of forming a hydroxyl group as a substituent, for example, a 2-hydroxyethyl group. The plurality of R ₂ and R ₃ may be the same or different.

R ₄ represents a substitutable group on the benzene ring, specifically, an alkyl group having 1 to 25 carbon atoms (methyl, ethyl, propyl, i-propyl, t-butyl, pentyl, hexyl, cyclohexyl, etc.), Halogenated alkyl group (trifluoromethyl, perfluorooctyl etc.), cycloalkyl group (cyclohexyl, cyclopentyl etc.), alkynyl group (propargyl etc.), glycidyl group, acrylate group, methacrylate group, aryl group (phenyl etc.), heterocyclic ring Groups (pyridyl, thiazolyl, oxazolyl, imidazolyl, furyl, pyrrolyl, pyrazinyl, pyrimidinyl, pyridazinyl, selenazolyl, sriphoranyl, piperidinyl, pyrazolyl, tetrazolyl, etc.), halogen atoms (chlorine, bromine, iodine, fluorine), alkoxy groups (methoxy, ethoxy) , Pyroxy, pentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy, etc.), aryloxy groups (phenoxy, etc.), alkoxycarbonyl groups (methyloxycarbonyl, ethyloxycarbonyl, butyloxycarbonyl, etc.), aryloxycarbonyl groups (phenyloxycarbonyl) ), Sulfonamide groups (methanesulfonamide, ethanesulfonamide, butanesulfonamide, hexanesulfonamide group, cyclohexanesulfonamide, benzenesulfonamide, etc.), sulfamoyl groups (aminosulfonyl, methylaminosulfonyl, dimethylaminosulfonyl, butylamino) Sulfonyl, hexylaminosulfonyl, cyclohexylaminosulfonyl, phenylaminosulfonyl, 2-pyridylaminos Sulfonyl, etc.), urethane groups (methylureido, ethylureido, pentylureido, cyclohexylureido, phenylureido, 2-pyridylureido, etc.), acyl groups (acetyl, propionyl, butanoyl, hexanoyl, cyclohexanoyl, benzoyl, pyridinoyl, etc.), Carbamoyl group (aminocarbonyl, methylaminocarbonyl, dimethylaminocarbonyl, propylaminocarbonyl, pentylaminocarbonyl group, cyclohexylaminocarbonyl, phenylaminocarbonyl, 2-pyridylaminocarbonyl), amide group (acetamide, propionamide, butanamide, hexaneamide, Benzamide etc.), sulfonyl group (methylsulfonyl, ethylsulfonyl, butylsulfonyl, cyclohexylsulfonyl, Phenylsulfonyl, 2-pyridylsulfonyl, etc.), amino group (amino, ethylamino, dimethylamino, butylamino, cyclopentylamino, anilino, 2-pyridylamino, etc.), cyano group, nitro group, sulfo group, carboxyl group, hydroxyl group, An oxamoyl group can be exemplified. These groups may be further substituted with these groups. n and m represent an integer of 0 to 2, and most preferably n and m are 0. A plurality of R ₄ may be the same or different.

R ₄ may form a saturated ring with R ₂ and R ₃ . R ₄ is preferably a hydrogen atom, a halogen atom or an alkyl group, more preferably a hydrogen atom.

  Specific examples of the compound represented by the general formula (RED) are given below, but the present invention is not limited thereto.

  These compounds (bisphenol compounds) represented by the general formula (RED) can be easily synthesized by a conventionally known method (for example, see Reference: Japanese Patent Application No. 2002-147562).

  The amount of the silver ion reducing agent used in the photothermographic dry imaging material of the present invention varies depending on the type of organic silver salt, the reducing agent, and other additives. A suitable amount is from 05 mol to 10 mol, preferably from 0.1 mol to 3 mol. Within this range, two or more silver ion reducing agents of the present invention may be used in combination. That is, it is preferable from the viewpoints of obtaining a high-quality and high-CP image that the use of reducing agents having different reactivity due to having different chemical structures is excellent in storage stability.

  In the present invention, it may be preferable that the reducing agent is added to and mixed with a photosensitive emulsion solution composed of photosensitive silver halide and organic silver salt grains and a solvent immediately before coating, because photographic performance fluctuation due to stagnation time is small. is there.

  In the silver salt photothermographic material of the present invention, the general formulas (1) to (4) described in JP-A No. 2003-43614 and JP-A No. 2003-66559 are used as development accelerators used in combination with the above reducing agent. Hydrazine derivatives and phenol derivatives represented by the general formulas (1) to (3) described in Japanese Patent Publication No. 1 are preferably used.

  The oxidation potential of the development accelerator used in the silver salt photothermographic material of the present invention is preferably 0.01 V to 0.4 V lower than the compound represented by the general formula (RED). More preferably, it is 0.01 V to 0.3 V lower than the compound represented by (RED). The development accelerator has an oxidation potential of 0.2 V or more by polarography measurement at the SCE counter electrode in a tetrahydrofuran: Britton / Robinson buffer solution adjusted to pH = 6 = 3: 2 mixed solvent. It is preferably 6 V or less, more preferably 0.3 V or more and 0.55 V or less. The pKa value in a 3: 2 mixed solvent of tetrahydrofuran: water is preferably 3 or more and 12 or less, more preferably 5 or more and 10 or less. Tetrahydrofuran adjusted to pH = 6: Britton-Robinson buffer solution = 3: 2 In a mixed solvent, the oxidation potential measured by polarography at the SCE counter electrode is 0.3 V or more and 0.55 V or less, tetrahydrofuran: water The pKa value in the 3: 2 mixed solvent is particularly preferably 5 or more and 10 or less.

  As the silver ion reducing agent according to the present invention, various reducing agents disclosed in European Patent No. 1,278,101 and Japanese Patent Application Laid-Open No. 2003-15252 can also be used.

  The amount of the silver ion reducing agent used in the photothermographic dry imaging material of the present invention varies depending on the type of organic silver salt, the reducing agent, and other additives. A suitable amount is from 05 mol to 10 mol, preferably from 0.1 mol to 3 mol. Within this range, two or more silver ion reducing agents of the present invention may be used in combination. That is, it is preferable from the viewpoints of obtaining a high-quality and high-CP image that the use of reducing agents having different reactivity due to having different chemical structures is excellent in storage stability.

  In the present invention, it may be preferable that the reducing agent is added to and mixed with a photosensitive emulsion solution composed of photosensitive silver halide and organic silver salt grains and a solvent immediately before coating, because photographic performance fluctuation due to stagnation time is small. is there.

[Chemical sensitization]
The photosensitive silver halide grains according to the present invention can be chemically sensitized. For example, use of a compound that releases a chalcogen such as sulfur, selenium, tellurium, or a noble metal ion that releases a noble metal ion such as gold ion by the methods described in JP-A Nos. 2001-249428 and 2001-249426 Thus, it is possible to form and impart a chemical sensitization center (chemical sensitization nucleus) capable of capturing electrons or holes generated by photoexcitation of photosensitive silver halide grains or spectral sensitizing dyes on the grains. In particular, it is preferably chemically sensitized with an organic sensitizer containing a chalcogen atom.

  These organic sensitizers containing chalcogen atoms are preferably compounds having groups capable of adsorbing to silver halide and unstable chalcogen atom sites.

  These organic sensitizers are disclosed in JP-A-60-150046, JP-A-4-109240, JP-A-11-218874, JP-A-11-218875, JP-A-11-218876, JP-A-11-194447, etc. The organic sensitizers having various structures can be used, and among them, the chalcogen atom is at least one kind of compound having a structure in which a carbon atom or a phosphorus atom is bonded with a double bond It is preferable. In particular, a thiourea derivative having a heterocyclic group and a triphenylphosphine sulfide derivative are preferred.

  As a method for chemical sensitization, techniques according to various chemical sensitization techniques conventionally used in the production of conventional silver halide light-sensitive materials for wet processing can be used (reference: (1) T Edited by H. James “The Theory of the Photographic Process” 4th edition, Macmillan Publishing Co., Ltd., 1977, (2) The Japan Photographic Society, “Basics of Photographic Engineering (Silver Salt Photography), Corona, 1979) In particular, when the silver halide grain emulsion is previously chemically sensitized and then mixed with non-photosensitive organic silver salt grains, it can be chemically sensitized by a conventional method.

The amount of the chalcogen compound used as the organic sensitizer varies depending on the chalcogen compound used, silver halide grains, reaction environment for chemical sensitization, etc., but is 10 ⁻⁸ to 10 ⁻ per mol of silver halide. ² mol is preferred, more preferably 10 ⁻⁷ to 10 ⁻³ mol. Environmental conditions for chemical sensitization are not particularly limited, but in the presence of a compound capable of annihilating or reducing the size of silver chalcogenide or silver nuclei on photosensitive silver halide grains, or In particular, it may be preferable to perform chalcogen sensitization using an organic sensitizer containing a chalcogen atom in the presence of an oxidizing agent capable of oxidizing silver nuclei. The sensitizing conditions in this case are preferably 6 to 11 as pAg, more preferably 7 to 10, pH 4 to 10, more preferably 5 to 8, and the temperature increases at 30 ° C. or lower. It is preferable to give a feeling.

  In addition, chemical sensitization using these organic sensitizers is preferably performed in the presence of a heteroatom-containing compound having adsorptivity to spectral sensitizing dyes or silver halide grains. By performing chemical sensitization in the presence of a compound having an adsorptivity to silver halide, dispersion of the chemical sensitization central core can be prevented, and high sensitivity and low fog can be achieved. Although the spectral sensitizing dye will be described later, preferred examples of the heteroatom-containing compound having adsorptivity to silver halide include nitrogen-containing heterocyclic compounds described in JP-A-3-24537. In the nitrogen-containing heterocyclic compound, examples of the heterocyclic ring include pyrazole ring, pyrimidine ring, 1,2,4-triazole ring, 1,2,3-triazole ring, 1,3,4-thiadiazole ring, 1,2 , 3-thiadiazole ring, 1,2,4-thiadiazole ring, 1,2,5-thiadiazole ring, 1,2,3,4-tetrazole ring, pyridazine ring, 1,2,3-triazine ring, these rings Can be mentioned, for example, a triazolotriazole ring, a diazaindene ring, a triazaindene ring, a pentaazaindene ring, and the like. A heterocyclic ring in which a monocyclic heterocyclic ring and an aromatic ring are condensed, for example, a phthalazine ring, a benzimidazole ring, an indazole ring, a benzthiazole ring, or the like can also be applied.

  Of these, an azaindene ring is preferable, and an azaindene compound having a hydroxyl group as a substituent, for example, a hydroxytriazaindene, tetrahydroxyazaindene, hydroxypentaazaindene compound, or the like is more preferable.

  The heterocyclic ring may have a substituent other than the hydroxyl group. Examples of the substituent include an alkyl group, a substituted alkyl group, an alkylthio group, an amino group, a hydroxyamino group, an alkylamino group, a dialkylamino group, an arylamino group, a carboxyl group, an alkoxycarbonyl group, a halogen atom, and a cyano group. You may have.

The amount of the heterocyclic compound added varies over a wide range depending on the size, composition, and other conditions of the silver halide grains, but the approximate amount is 10 ^-6 per mole of silver halide. It is in the range of ˜1 mol, preferably in the range of 10 ⁻⁴ to 10 ⁻¹ mol.

  The photosensitive silver halide according to the present invention can be subjected to noble metal sensitization using a compound that releases noble metal ions such as gold ions. For example, a chloroaurate or an organic gold compound can be used as a gold sensitizer. The gold sensitization technique disclosed in JP-A-11-194447 is useful as a reference.

  In addition to the above-described sensitization methods, reduction sensitization methods and the like can also be used. Examples of reduction sensitization shell-like compounds include ascorbic acid, thiourea dioxide, stannous chloride, hydrazine derivatives, A borane compound, a silane compound, a polyamine compound, or the like can be used. Further, reduction sensitization can be performed by ripening the emulsion while maintaining the pH at 7 or higher or the pAg at 8.3 or lower.

  In the present invention, the silver halide grains subjected to chemical sensitization may be formed in the presence of an aliphatic carboxylic acid silver salt, or in the absence of the organic silver salt, A mixture of the two may be used.

  In the present invention, when chemical sensitization is performed on the surface of the photosensitive silver halide grains, it is necessary that the chemical sensitization effect substantially disappears after the thermal development process. Here, the chemical sensitization effect substantially disappears when the sensitivity of the imaging material obtained by the chemical sensitization technique is 1.1 when the chemical sensitization is not performed after the thermal development process. Say to decrease below. In order to eliminate the chemical sensitization effect in the heat development process, an oxidant capable of destroying the chemical sensitization center (chemical sensitization nucleus) by an oxidation reaction at the time of heat development, for example, the above-mentioned halogen radical releasing compound, etc. It is necessary to contain an appropriate amount of the above in the emulsion layer and / or the non-photosensitive layer of the imaging material. The content of the oxidizing agent is preferably adjusted in consideration of the oxidizing power of the oxidizing agent, the reduction range of the chemical sensitization effect, and the like.

[Spectral sensitization]
The photosensitive silver halide in the present invention is preferably subjected to spectral sensitization by adsorbing a spectral sensitizing dye. As spectral sensitizing dyes, cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, styryl dyes, hemicyanine dyes, oxonol dyes, hemioxonol dyes and the like can be used. For example, JP-A-63-159841, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, JP-A-63-304242, JP-A-63-15245, US Pat. No. 4,639,414, No. 4,740,455, No. 4,741,966, No. 4,751,175, No. 4,835,096 can be used.

  Useful sensitizing dyes used in the present invention include, for example, Research Disclosure (hereinafter abbreviated as RD) 17643IV-A (December 1978 p.23), RD18431X (August 1978 p.437). It is described in the literature described or cited. In particular, it is preferable to use a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of the light sources of various laser imagers and scanners. For example, compounds described in JP-A Nos. 9-34078, 9-54409, and 9-80679 are preferably used.

  Useful cyanine dyes are, for example, cyanine dyes having basic nuclei such as thiazoline nucleus, oxazoline nucleus, pyrroline nucleus, pyridine nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus and imidazole nucleus. Useful merocyanine dyes are preferably acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus in addition to the basic nuclei described above. Including.

  In the present invention, a sensitizing dye having spectral sensitivity particularly in the infrared can also be used. Examples of infrared spectral sensitizing dyes preferably used include infrared spectral sensitization disclosed in US Pat. Nos. 4,536,473, 4,515,888, 4,959,294, and the like. Examples include dyes.

  In the silver salt photothermographic dry imaging material according to the present invention, the sensitizing dye represented by the following general formula (SD-1) as described in Japanese Patent Application No. 2003-102726 and the following general formula (SD-2) It is preferable to contain at least one selected from sensitizing dyes represented by

In the formula, Y ₁ and Y ₂ each represent an oxygen atom, a sulfur atom, a selenium atom, or a —CH═CH— group, and L _{1 to} L ₉ each represent a methine group. R ₁ and R ₂ each represents an aliphatic group. R ₃ , R ₄ , R ₂₃ and R ₂₄ each represent a lower alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group, or a heterocyclic group. W ₁ , W ₂ , W ₃ , and W ₄ are each a hydrogen atom, a substituent, or a nonmetallic atom necessary for bonding between W ₁ and W ₂ , W ₃ and W ₄ to form a condensed ring. Represents a group. Or R ₃ and W ₁ , R ₃ and W ₂ , R ₂₃ and W ₁ , R ₂₃ and W ₂ , R ₄ and W ₃ , R ₄ and W ₄ , R ₂₄ and W ₃ , R ₂₄ and W ₄ Represents a group of non-metallic atoms necessary to form a 5-membered or 6-membered condensed ring by bonding. X ₁ represents an ion necessary for canceling the charge in the molecule, and k 1 represents the number of ions necessary for canceling the charge in the molecule. m1 represents 0 or 1. n1 and n2 each represents 0, 1 or 2. However, n1 and n2 are not 0 at the same time.

  The above-mentioned infrared sensitizing dyes are described in, for example, HM Hammer, The Chemistry of Heterocyclic Compounds, Vol. 18, The Cyanine Dies and Related Compounds, published by A. Weissberger ed. It can be easily synthesized by this method.

  These infrared sensitizing dyes may be added at any time after the silver halide is prepared. For example, silver halide grains or halogens may be added in a so-called solid dispersion state added to a solvent or dispersed in a fine particle form. It can be added to a light-sensitive emulsion containing silver halide grains / aliphatic carboxylic acid silver salt grains. Similarly to the heteroatom-containing compound having adsorptivity to the silver halide grains, chemical sensitization can be performed after adding and adsorbing to the silver halide grains prior to chemical sensitization. Thus, dispersion of the chemical sensitization central core can be prevented, and high sensitivity and low fog can be achieved.

  In the present invention, one kind of spectral sensitizing dye may be used alone, but as described above, it is preferable to use a combination of plural kinds of spectral sensitizing dyes. The combination is often used for the purpose of supersensitization and enlargement or adjustment of the photosensitive wavelength region.

  The emulsion containing the photosensitive silver halide and the aliphatic carboxylic acid silver salt used in the silver salt photothermographic dry imaging material of the present invention is not only a sensitizing dye but also a dye having no spectral sensitizing action itself or visible light. In the emulsion, a substance that does not substantially absorb the color and expresses a supersensitization effect may be contained in the emulsion, whereby the silver halide grains may be supersensitized.

  Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are described in RD17643 (issued in December, 1978), page 23, Section J, or Japanese Patent Publication No. 9-25500, 43-4933, JP-A-59-19032, JP-A-59-192242, JP-A-5-341432, and the like. Examples of supersensitizers include heteroaromatic mercapto represented by the following. A compound or a mercapto derivative compound is preferred.

Ar-SM
In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring or condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium, or tellurium atoms. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzthiazole, naphthothiazole, benzoxazole, naphthoxazole, benzselenazole, benztelrazole, imidazole, oxazole, pyrazole, triazole, triazine, pyrimidine, pyridazine, pyrazine, pyridine , Purine, quinoline, or quinazoline. However, other heteroaromatic rings are also included.

  In addition, mercapto derivative compounds that substantially produce the above mercapto compounds when included in a dispersion of an aliphatic carboxylic acid silver salt or silver halide grain emulsion are also included. In particular, mercapto derivative compounds represented below are preferred examples.

Ar-SS-Ar
Ar in the formula has the same meaning as in the case of the mercapto compound represented above.

  The heteroaromatic ring includes, for example, a halogen atom (for example, chlorine, bromine, iodine), a hydroxyl group, an amino group, a carboxyl group, and an alkyl group (for example, one or more carbon atoms, preferably 1 to 4 carbon atoms). It may have a substituent selected from the group consisting of those having a carbon atom) and alkoxy groups (for example, those having 1 or more carbon atoms, preferably 1 to 4 carbon atoms).

  In addition to the above supersensitizers, macrocycles having heteroatoms disclosed in JP-A-2001-330918 can also be used as supersensitizers.

  The supersensitizer according to the present invention is preferably used in an amount of 0.001 to 1.0 mol per mol of silver in a photosensitive layer containing an organic silver salt and silver halide grains. Particularly preferred is an amount of 0.01 to 0.5 mole per mole of silver.

  In the present invention, it is necessary that the spectral sensitizing dye is adsorbed on the surface of the photosensitive silver halide grain to effect spectral sensitization, and that the spectral sensitizing effect should substantially disappear after the thermal development process. It is. Here, the spectral sensitization effect substantially disappears when the sensitivity of the imaging material obtained with a sensitizing dye, supersensitizer, etc. is the sensitivity when the spectral sensitization is not performed after the thermal development process. It means to decrease to 1.1 times or less.

  In order to eliminate the chemical sensitization effect in the thermal development process, use a spectral sensitizing dye that is easily detached from the silver halide grains by heat during thermal development or / and destroy the spectral sensitizing dye by an oxidation reaction. It is necessary to contain an appropriate amount of an oxidizing agent that can be used, such as the halogen radical-releasing compound, in the emulsion layer and / or the non-photosensitive layer of the imaging material. The content of the oxidizing agent is preferably adjusted in consideration of the oxidizing power of the oxidizing agent, the reduction range of the spectral sensitization effect, and the like.

[Silver saving agent]
In the present invention, the photosensitive layer or the non-photosensitive layer preferably contains a silver saving agent.

  The silver saving agent used in the present invention refers to a compound that can reduce the amount of silver necessary to obtain a certain silver image density. Various action mechanisms of the function of decreasing can be considered, but a compound having a function of improving the covering power of developed silver is preferable. Here, the covering power of developed silver refers to the optical density per unit amount of silver. This silver saving agent can be present in the photosensitive layer, the non-photosensitive layer, or both.

  Preferred examples of the silver saving agent include hydrazine derivatives represented by the following general formula (H), vinyl compounds represented by the following general formula (G), quaternary onium compounds represented by the following general formula (P), and the like. Can be mentioned.

In the general formula [H], A ₀ represents an aliphatic group, aromatic group, heterocyclic group or -G ₀ -D ₀ group which may have a substituent, and B ₀ represents a blocking group. , A ₁ and A ₂ both represent a hydrogen atom, or one represents a hydrogen atom and the other represents an acyl group, a sulfonyl group or an oxalyl group. Here, G ₀ is —CO— group, —COCO— group, —CS— group, —C (═NG ₁ D ₁ ) — group, —SO— group, —SO ₂ — group or —P (O) ( G ₁ D ₁ ) — group, G ₁ represents a simple bond, —O— group, —S— group or —N (D ₁ ) — group, D ₁ represents an aliphatic group, aromatic group, complex When a ring group or a hydrogen atom is represented and a plurality of D ₁ are present in the molecule, they may be the same or different. D ₀ represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group. Preferred D ₀ includes a hydrogen atom, an alkyl group, an alkoxy group, an amino group and the like.

In the general formula [H], the aliphatic group represented by A ₀ is preferably one having 1 to 30 carbon atoms, particularly preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. Examples thereof include a methyl group, an ethyl group, a t-butyl group, an octyl group, a cyclohexyl group, and a benzyl group. These are further suitable substituents (for example, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a sulfoxy group). Group, sulfonamido group, sulfamoyl group, acylamino group, ureido group, etc.).

In the general formula [H], the aromatic group represented by A ₀ is preferably a monocyclic or condensed aryl group, such as a benzene ring or a naphthalene ring, and the heterocyclic group represented by A ₀ is A heterocyclic ring containing at least one heteroatom selected from nitrogen, sulfur and oxygen atoms in a single ring or a condensed ring is preferred, such as a pyrrolidine ring, imidazole ring, tetrahydrofuran ring, morpholine ring, pyridine ring, pyrimidine ring, quinoline ring, Examples include a thiazole ring, a benzothiazole ring, a thiophene ring, and a furan ring. Aromatic groups A _0, heterocyclic group or -G ₀ -D ₀ group may have a substituent. Particularly preferred as A ₀ are an aryl group and a —G ₀ -D ₀ group.

In the general formula [H], A ₀ preferably contains at least one anti-diffusion group or silver halide adsorption group. As the anti-diffusion group, a ballast group commonly used in an immobile photographic additive such as a coupler is preferable. As the ballast group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, phenyl, which are photographically inactive, are preferable. Group, phenoxy group, alkylphenoxy group and the like, and the total number of carbon atoms in the substituent portion is preferably 8 or more.

  In the general formula [H], examples of the silver halide adsorption promoting group include thiourea, thiourethane group, mercapto group, thioether group, thione group, heterocyclic group, thioamide heterocyclic group, mercapto heterocyclic group, and JP-A-64. And the adsorbing group described in -90439.

In the general formula [H], B ₀ represents a blocking group, preferably a -G ₀ -D ₀ group, and G ₀ represents a -CO- group, a -COCO- group, a -CS- group, -C (= NG ₁ D ₁ ) — group, —SO— group, —SO ₂ — group or —P (O) (G ₁ D ₁ ) — group. Preferred examples of G ₀ include —CO— group and —COCO— group, G ₁ represents a simple bond, —O— group, —S— group or —N (D ₁ ) — group, and D ₁ represents fatty acid. Represents a group, an aromatic group, a heterocyclic group or a hydrogen atom, and when a plurality of D ₁ are present in the molecule, they may be the same or different. D ₀ represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group, and preferred D ₀ is a hydrogen atom, an alkyl group, an alkoxy group, An amino group etc. are mentioned. A ₁ and A ₂ are both hydrogen atoms, or one is a hydrogen atom and the other is an acyl group (acetyl group, trifluoroacetyl group, benzoyl group, etc.), sulfonyl group (methanesulfonyl group, toluenesulfonyl group, etc.), or oxalyl group (Etoxalyl group, etc.).

  These compounds represented by the general formula [H] can be easily synthesized by known methods. For example, it can be synthesized with reference to US Pat. Nos. 5,464,738 and 5,496,695.

  Other hydrazine derivatives that can be preferably used include compounds H-1 to H-29 described in U.S. Pat. No. 5,545,505 columns 11 to 20, and U.S. Pat. No. 5,464,738 columns 9 to 11. Compounds 1 to 12 described. These hydrazine derivatives can be synthesized by a known method.

  In the general formula (G), X and R are shown in a cis form, but a form in which X and R are trans is also included in the general formula (G). The same applies to the structure display of a specific compound.

  In General Formula (G), X represents an electron-withdrawing group, and W represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a halogen atom, an acyl group, a thioacyl group, an oxalyl group, an oxy group. Oxalyl, thiooxalyl, oxamoyl, oxycarbonyl, thiocarbonyl, carbamoyl, thiocarbamoyl, sulfonyl, sulfinyl, oxysulfinyl, thiosulfinyl, sulfamoyl, oxysulfinyl, thiosulfinyl, Sulfinamoyl group, phosphoryl group, nitro group, imino group, N-carbonylimino group, N-sulfonylimino group, dicyanoethylene group, ammonium group, sulfonium group, phosphonium group, pyrylium group, immonium group are represented.

  R is a halogen atom, hydroxyl group, alkoxy group, aryloxy group, heterocyclic oxy group, alkenyloxy group, acyloxy group, alkoxycarbonyloxy group, aminocarbonyloxy group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group , An alkenylthio group, an acylthio group, an alkoxycarbonylthio group, an aminocarbonylthio group, an organic or inorganic salt of a hydroxyl group or a mercapto group (for example, sodium salt, potassium salt, silver salt, etc.), amino group, alkylamino group, Cyclic amino group (for example, pyrrolidino group), acylamino group, oxycarbonylamino group, heterocyclic group (5-6 membered nitrogen-containing heterocycle such as benztriazolyl group, imidazolyl group, triazolyl group, tetrazolyl group, etc.), Ureido group, sulfone It represents a bromide group. X and W, X and R may be bonded to each other to form a cyclic structure. Examples of the ring formed by X and W include pyrazolone, pyrazolidinone, cyclopentanedione, β-ketolactone, β-ketolactam and the like.

  The general formula (G) will be further described. The electron-withdrawing group represented by X is a substituent whose substituent constant σp can take a positive value. Specifically, a substituted alkyl group (such as halogen-substituted alkyl), a substituted alkenyl group (such as cyanovinyl), a substituted / unsubstituted alkynyl group (such as trifluoromethylacetylenyl, cyanoacetylenyl), a substituted aryl group (such as cyano) Phenyl, etc.), substituted / unsubstituted heterocyclic groups (pyridyl, triazinyl, benzoxazolyl, etc.), halogen atoms, cyano groups, acyl groups (acetyl, trifluoroacetyl, formyl, etc.), thioacetyl groups (thioacetyl, thioformyl, etc.) ), Oxalyl group (such as methyloxalyl), oxyoxalyl group (such as etoxalyl), thiooxalyl group (such as ethylthiooxalyl), oxamoyl group (such as methyloxamoyl), oxycarbonyl group (such as ethoxycarbonyl), carboxyl group, thiol Carbonyl group (ethylthiocarboni ), Carbamoyl group, thiocarbamoyl group, sulfonyl group, sulfinyl group, oxysulfonyl group (such as ethoxysulfonyl), thiosulfonyl group (such as ethylthiosulfonyl), sulfamoyl group, oxysulfinyl group (such as methoxysulfinyl), thiosulfinyl group (Such as methylthiosulfinyl), sulfinamoyl group, phosphoryl group, nitro group, imino group, N-carbonylimino group (N-acetylimino etc.), N-sulfonylimino group (N-methanesulfonylimino etc.), dicyanoethylene group, ammonium Group, sulfonium group, phosphonium group, pyrylium group, immonium group, and the like include a heterocyclic group in which an ammonium group, sulfonium group, phosphonium group, immonium group and the like form a ring. A substituent having a σp value of 0.30 or more is particularly preferable.

  Examples of the alkyl group represented by W include methyl, ethyl, trifluoromethyl, etc., examples of the alkenyl group include vinyl, halogen-substituted vinyl, cyanovinyl, etc., examples of the alkynyl group include acetylenyl, cyanoacetylenyl, and the like as the aryl group. Nitrophenyl, cyanophenyl, pentafluorophenyl and the like, and examples of the heterocyclic group include pyridyl, pyrimidyl, triazinyl, succinimide, tetrazolyl, triazolyl, imidazolyl and benzoxazolyl. W is preferably an electron-withdrawing group having a positive σp value, and more preferably 0.30 or more.

  Among the substituents of R, a hydroxyl group, a mercapto group, an alkoxy group, an alkylthio group, a halogen atom, an organic or inorganic salt of a hydroxyl group or a mercapto group, and a heterocyclic group are preferable, and a hydroxyl group, more preferably An organic or inorganic salt of an alkoxy group, a hydroxyl group or a mercapto group, or a heterocyclic group is exemplified, and an organic or inorganic salt of a hydroxyl group, a hydroxyl group or a mercapto group is particularly preferred.

  Of the substituents X and W, those having a thioether bond in the substituent are preferred.

In the general formula (P), Q ₃ represents a nitrogen atom or a phosphorus atom, R ₁ , R ₂ , R ₃ and R ₄ each represent a hydrogen atom or a substituent, and X − represents an anion. R _{1 to} R ₄ may be connected to each other to form a ring.

Examples of the substituent represented by R _{1 to} R ₄ include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group), an alkenyl group (for example, an allyl group, a butenyl group). Group), alkynyl group (eg, propargyl group, butynyl group, etc.), aryl group (eg, phenyl group, naphthyl group, etc.), heterocyclic group (eg, piperidinyl group, piperazinyl group, morpholinyl group, pyridyl group, furyl group) , Thienyl group, tetrahydrofuryl group, tetrahydrothienyl group, sulfolanyl group, etc.), amino group and the like.

Examples of the ring that R _{1 to} R ₄ can be formed by connecting to each other include a piperidine ring, a morpholine ring, a piperazine ring, a quinuclidine ring, a pyridine ring, a pyrrole ring, an imidazole ring, a triazole ring, and a tetrazole ring.

The group represented by R _{1 to} R ₄ may have a substituent such as a hydroxyl group, an alkoxy group, an aryloxy group, a carboxyl group, a sulfo group, an alkyl group, and an aryl group. R ₁ , R ₂ , R ₃ and R ₄ are preferably a hydrogen atom and an alkyl group.

  Examples of the anion represented by X- include inorganic and organic anions such as halogen ions, sulfate ions, nitrate ions, acetate ions, and p-toluenesulfonate ions.

The quaternary onium compound can be easily synthesized in accordance with a known method. For example, the tetrazolium compound can be synthesized by referring to Chemical Reviews vol. 55 p. The method described in 335-483 can be referred to. The amount of the silver saving agent added is in the range of 10 ⁻⁵ to 1 mol, preferably 10 ^{−4 to} 5 × 10 ⁻¹ mol, per mol of the aliphatic carboxylic acid silver salt.

  In the present invention, it is also preferred that at least one silver saving agent is a silane compound. In the present invention, the silane compound used as a silver saving agent is an alkoxysilane compound having two or more primary or secondary amino groups or a salt thereof as disclosed in Japanese Patent Application Laid-Open No. 2003-5324. Is preferred.

  As a silver saving agent, when an alkoxysilane compound or a salt thereof, or a Schiff base is added to the image forming layer, it is preferably added in a range of usually 0.00001 to 0.05 mol with respect to 1 mol of silver. . The same category applies when both an alkoxysilane compound or a salt thereof and a Schiff base are added to the image forming layer.

〔binder〕
Binders suitable for the silver salt photothermographic dry imaging materials of the present invention are transparent or translucent and generally colorless and are natural polymer synthetic resins, polymers and copolymers, and other media forming films such as: gelatin, gum arabic, Poly (vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid) ), Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters) Polyesters, polyurethanes, phenoxy resins, poly (vinylidene chloride), poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and polyamides. It may be hydrophilic or non-hydrophilic.

  Preferred binders for the photosensitive layer of the silver salt photothermographic dry imaging material of the present invention are polyvinyl acetals, and a particularly preferred binder is polyvinyl butyral. Details will be described later. In addition, for non-photosensitive layers such as overcoat layers and undercoat layers, particularly protective layers and backcoat layers, cellulose esters which are polymers having a higher softening temperature, particularly polymers such as triacetyl cellulose and cellulose acetate butyrate. Is preferred. In addition, as needed, said binder can be used in combination of 2 or more type.

Such a binder is used in an effective range to function as a binder. The effective range can be easily determined by one skilled in the art. For example, as an index for holding at least an aliphatic carboxylic acid silver salt in the photosensitive layer, the ratio of the binder to the aliphatic carboxylic acid silver salt is 15: 1 to 1: 2, particularly 8: 1 to 1: 1. A range is preferred. That is, it is preferable amount of the binder in the photosensitive layer is a 1.5~6g / m ^2. More preferably, it is 1.7-5 g / m < ² >. If it is less than 1.5 g / m ² , the density of the unexposed area is significantly increased and may not be used.

  In the present invention, the heat transition temperature after development at a temperature of 100 ° C. or higher is preferably 46 ° C. or higher and 200 ° C. or lower, more preferably 70 ° C. or higher and 105 ° C. or lower. The heat transition temperature referred to in the present invention is a value indicated by the VICAT softening point or ring-and-ball method, and is a differential scanning calorimeter (DSC), for example, EXSTAR 6000 (manufactured by Seiko Electronics), DSC220C (manufactured by Seiko Electronics Industry) DSC-7 (manufactured by Perkin Elmer Co., Ltd.) or the like is used to indicate the endothermic peak when the thermally developed photosensitive layer is isolated and measured. In general, polymer compounds have a glass transition point Tg, but in silver salt photothermographic dry imaging materials, a large endothermic peak appears below the Tg value of the binder resin used in the photosensitive layer. To do. As a result of diligent investigation focusing on this thermal transition point temperature, by setting the thermal transition point temperature to 46 ° C. or higher and 200 ° C. or lower, not only the fastness of the formed coating film is increased, but also the sensitivity, maximum The inventors have newly found that photographic performance such as density and image storage stability is greatly improved, and have reached the present invention.

  The glass transition temperature (Tg) was obtained by the method described in “Polymer Handbook” pages III-139 to III-179 (1966, Wiley and Sun, Inc.) by Brandrup et al. Tg in the case of a polymer resin is obtained by the following formula.

Tg (copolymer) (° C.) = V ₁ Tg ₁ + v ₂ Tg ₂ +... + V _n Tg _{n
Wherein, v 1, v 2 ··· v} n represents the mass fraction of the monomer in the _{copolymer, Tg 1, Tg 2 ··· Tg} n are each monomer in the copolymer Tg (° C.) of a single polymer obtained from the body. ]
The accuracy of Tg calculated according to the above equation is ± 5 ° C.

  In the silver salt photothermographic dry imaging material of the present invention, as a binder contained in a photosensitive layer containing an aliphatic carboxylic acid silver salt, photosensitive silver halide grains, a reducing agent, etc. on a support, a conventionally known polymer is used. Compounds can be used. The Tg is 70 to 105 ° C., the number average molecular weight is 1,000 to 1,000,000, preferably 10,000 to 500,000, and the degree of polymerization is about 50 to 1,000. Examples of such include vinyl chloride, vinyl acetate, vinyl alcohol, maleic acid, acrylic acid, acrylic ester, vinylidene chloride, acrylonitrile, methacrylic acid, methacrylic ester, styrene, butadiene, ethylene, vinyl butyral, vinyl acetal, There are compounds made of a polymer or copolymer containing an ethylenically unsaturated monomer such as vinyl ether as a constituent unit, polyurethane resins, and various rubber resins.

  Moreover, phenol resin, epoxy resin, polyurethane curable resin, urea resin, melamine resin, alkyd resin, formaldehyde resin, silicone resin, epoxy-polyamide resin, polyester resin, and the like can be given. These resins are described in detail in “Plastic Handbook” issued by Asakura Shoten. There is no restriction | limiting in particular in these high molecular compounds, A homopolymer or a copolymer may be sufficient if the glass transition temperature (Tg) of the induced | guided | derived polymer exists in the range of 70-105 degreeC.

  Polymers or copolymers containing such ethylenically unsaturated monomers as structural units include acrylic acid alkyl esters, acrylic acid aryl esters, methacrylic acid alkyl esters, methacrylic acid aryl esters, alkyl cyanoacrylates. Ester, cyanoacrylic acid aryl ester and the like, and the alkyl group and aryl group thereof may or may not be substituted. Specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, amyl, hexyl, cyclohexyl, benzyl, chlorobenzyl, octyl, stearyl, sulfopropyl, N-ethyl-phenylaminoethyl, 2- (3-phenylpropyloxy) ethyl , Dimethyl Minophenoxyethyl, furfuryl, tetrahydrofurfuryl, phenyl, cresyl, naphthyl, 2-hydroxyethyl, 4-hydroxybutyl, triethylene glycol, dipropylene glycol, 2-methoxyethyl, 3-methoxybutyl, 2-acetoxyethyl, 2 -Acetoacetoxyethyl, 2-ethoxyethyl, 2-iso-propoxyethyl, 2-butoxyethyl, 2- (2-methoxyethoxy) ethyl, 2- (2-ethoxyethoxy) ethyl, 2- (2-butoxyethoxy) Examples thereof include ethyl, 2-diphenylphosphorylethyl, ω-methoxypolyethylene glycol (addition mole number n = 6), allyl, dimethylaminoethylmethyl chloride salt and the like.

  In addition, the following monomers can be used. Specific examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl chloroacetate, vinyl methoxyacetate, vinyl phenyl acetate, vinyl benzoate, vinyl salicylate. N-substituted acrylamides, N-substituted methacrylamides and acrylamides, methacrylamides: N-substituents include methyl, ethyl, propyl, butyl, tert-butyl, cyclohexyl, benzyl, hydroxymethyl, methoxyethyl, dimethyl Aminoethyl, phenyl, dimethyl, diethyl, β-cyanoethyl, N- (2-acetoacetoxyethyl), diacetone and the like; olefins: for example, dicyclopentadiene, ethylene, propylene, 1- Ten, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, 2,3-dimethylbutadiene, etc .; styrenes: for example, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, tert-butylstyrene , Chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, vinyl benzoic acid methyl ester, etc .; vinyl ethers: for example, methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxyethyl vinyl ether, dimethylaminoethyl vinyl ether N-substituted maleimides: As N-substituent, methyl, ethyl, propyl, butyl, tert-butyl, cyclohexyl , Benzyl, n-dodecyl, phenyl, 2-methylphenyl, 2,6-diethylphenyl, 2-chlorophenyl, etc .; others include butyl crotonate, hexyl crotonate, dimethyl itaconate, dibutyl itaconate , Diethyl maleate, dimethyl maleate, dibutyl maleate, diethyl fumarate, dimethyl fumarate, dibutyl fumarate, methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, glycidyl acrylate, glycidyl methacrylate, N-vinyl oxazolidone, N -Vinylpyrrolidone, acrylonitrile, methacrylonitrile, methylenemalonnitrile, vinylidene chloride and the like can be mentioned.

  Among these, particularly preferred examples include methacrylic acid alkyl esters, methacrylic acid aryl esters, styrenes, and the like. Among such polymer compounds, it is preferable to use a polymer compound having an acetal group. The polymer compound having an acetal group is preferable because it is excellent in compatibility with the aliphatic carboxylic acid to be produced and has a great effect of preventing the film from being softened.

  As the polymer compound having an acetal group, a compound represented by the following general formula (V) is particularly preferable.

[Wherein, R ₁ represents an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group, but is preferably a group other than an aryl group. R ₂ represents an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, —COR ₃ or —CONHR ₃ . R ₃ has the same meaning as R ₁ . ]
The unsubstituted alkyl group represented by R ₁ , R ₂ , or R ₃ is preferably an alkyl group having 1 to 20 carbon atoms, particularly preferably 1 to 6 carbon atoms. These may be linear or branched, and preferably a linear alkyl group. Examples of such unsubstituted alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-amyl, t-amyl, n -Hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, t-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-octadecyl group, etc. Is particularly preferably a methyl group or a propyl group.

  As an unsubstituted aryl group, a C6-C20 thing is preferable, for example, a phenyl group, a naphthyl group, etc. are mentioned. Examples of the group that can be substituted with the above alkyl group or aryl group include an alkyl group (for example, a methyl group, an n-propyl group, a t-amyl group, a t-octyl group, an n-nonyl group, a dodecyl group), an aryl group. (For example, phenyl group), nitro group, hydroxyl group, cyano group, sulfo group, alkoxy group (for example, methoxy group), aryloxy group (for example, phenoxy group), acyloxy group (for example, acetoxy group), Acylamino group (for example, acetylamino group), sulfonamide group (for example, methanesulfonamide group), sulfamoyl group (for example, methylsulfamoyl group), halogen atom (for example, fluorine atom, chlorine atom, bromine atom) ), Carboxy group, carbamoyl group (for example, methylcarbamoyl group, etc.), alkoxycarbonyl group (for example, metho Shiruboniru group), a sulfonyl group (e.g., methyl sulfonyl group). When there are two or more substituents, they may be the same or different. The total carbon number of the substituted alkyl group is preferably 1-20, and the total carbon number of the substituted aryl group is preferably 6-20.

The R _2, -COR ₃ (R ₃ is an alkyl group or an aryl group), - CONHR ₃ (R ₃ is an aryl group). a, b, and c are values representing the mass of each repeating unit in mol (mol)%, a is 40 to 86 mol%, b is 0 to 30 mol%, and c is in the range of 0 to 60 mol%. A + b + c = 100 mol%, particularly preferably a is in the range of 50 to 86 mol%, b is 5 to 25 mol%, and c is 0 to 40 mol%. Each repeating unit having each composition ratio of a, b, and c may be composed of only the same one or may be composed of different ones.

As the polyurethane resin that can be used in the present invention, those having a known structure such as polyester polyurethane, polyether polyurethane, polyether polyester polyurethane, polycarbonate polyurethane, polyester polycarbonate polyurethane, and polycaprolactone polyurethane can be used. For all of the polyurethane shown here, if _{necessary, -COOM, -SO 3 M, -OSO} 3 M, -P = O (OM) 2, -O-P = O (OM) 2, (M is hydrogen Represents an atom or an alkali metal base), —N (R ₄ ) ₂ , —N ⁺ (R ₄ ) ₃ (R ₄ represents a hydrocarbon group, and a plurality of R ₄ may be the same or different); It is preferable to use one in which at least one polar group selected from an epoxy group, —SH, —CN and the like is introduced by copolymerization or addition reaction. The amount of such a polar group is 10 ⁻¹ to 10 ⁻⁸ mol / g, preferably 10 ⁻² to 10 ⁻⁶ mol / g. In addition to these polar groups, it is preferable to have at least one OH group in total at least one at the polyurethane molecule end. Since OH groups are cross-linked with polyisocyanate which is a curing agent to form a three-dimensional network structure, it is more preferable that the OH groups are contained in the molecule. In particular, it is preferable that the OH group is at the molecular end because the reactivity with the curing agent is high. The polyurethane preferably has 3 or more OH groups at the molecular terminals, and particularly preferably 4 or more. When polyurethane is used, the glass transition temperature is preferably 70 to 105 ° C., the elongation at break is 100 to 2000%, and the stress at break is preferably 0.5 to 100 N / mm ² .

  In the present invention, the polymer compound represented by the general formula (V) is synthesized by a general synthesis method described in “vinyl acetate resin” edited by Ichiro Sakurada (Polymer Chemistry Publishing Society, 1962) and the like. Can do.

  These polymer compounds may be used alone as a binder, or two or more kinds may be blended and used. In the photosensitive silver salt-containing layer (preferably photosensitive layer) of the present invention, the above polymer is used as a main binder. The main binder as used herein refers to “a state in which the polymer occupies 50% by mass or more of the total binder of the photosensitive silver salt-containing layer”. Therefore, other polymers may be blended and used within a range of less than 50% by weight of the total binder. These polymers are not particularly limited as long as the polymers of the present invention are soluble. More preferably, polyvinyl acetate, a polyacrylic resin, a urethane resin, etc. are mentioned.

  Examples of the crosslinking agent used in the present invention include various crosslinking agents conventionally used for silver halide photographic light-sensitive materials, such as aldehyde-based, epoxy-based, and ethyleneimine described in JP-A-50-96216. , Vinyl sulfone, sulfonic acid ester, acryloyl, carbodiimide, and silane compound crosslinking agents can be used, but the following isocyanate compounds, silane compounds, epoxy compounds, or acid anhydrides are preferred.

  An isocyanate-based and thioisocyanate-based crosslinking agent represented by the following general formula [IC], which is one of the preferable ones, will be described.

General Formula [IC] X = C = N-L- (N = C = X)
In the formula, v is 1 or 2, L is an alkyl group, an alkenyl group, an aryl group or an alkylaryl group, a v + 1 valent linking group, and X is an oxygen or sulfur atom.

  In the compound represented by the above general formula [IC], the aryl ring of the aryl group may have a substituent. Examples of preferred substituents are selected from halogen atoms (for example, bromine atoms or chlorine atoms), hydroxyl groups, amino groups, carboxyl groups, alkyl groups and alkoxy groups.

  The isocyanate-based crosslinking agent includes isocyanates having at least two isocyanate groups and adducts thereof (adducts), and more specifically, aliphatic diisocyanates and aliphatic diisocyanates having a cyclic group. Benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates and divalent or trivalent with these isocyanates Examples include adducts with polyalcohols.

  As specific examples, isocyanate compounds described on pages 10 to 12 of JP-A-56-5535 can be used.

  Note that the adduct body of isocyanate and polyalcohol has particularly high ability to improve interlayer adhesion, and prevent layer peeling, image shift, and bubble generation. Such isocyanates may be placed in any part of the silver salt photothermographic dry imaging material. For example, in the support (especially when the support is paper, it can be included in the size composition), photosensitive layer, surface protective layer, intermediate layer, antihalation layer, subbing layer, etc. It can be added to any one of these layers, and can be added to one or more of these layers.

  As the thioisocyanate-based crosslinking agent that can be used in the present invention, compounds having a thioisocyanate structure corresponding to the above-mentioned isocyanates are also useful.

  The amount of the crosslinking agent used in the present invention is in the range of 0.001 to 2 mol, preferably 0.005 to 0.5 mol, with respect to 1 mol of silver.

  The isocyanate compound and thioisocyanate compound that can be contained in the present invention are preferably compounds that function as the above-mentioned crosslinking agent, but in the above general formula, v is zero (0), that is, the functional group is one. Even if it is a compound which has only, a good result is obtained.

  Examples of the silane compound that can be used as a crosslinking agent in the present invention include compounds represented by general formula (1) or general formula (2) described in JP-A-2002-22203.

In these general formulas, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each an optionally substituted linear, branched or cyclic C 1-30 carbon atom. Alkyl group (methyl group, ethyl group, butyl group, octyl group, dodecyl group, cycloalkyl group, etc.), alkenyl group (propenyl group, butenyl group, nonenyl group, etc.), alkynyl group (acetylene group, bisacetylene group, phenylacetylene) Group), aryl group or heterocyclic group (phenyl group, naphthyl group, tetrahydropyran group, pyridyl group, furyl group, thiophenyl group, imidazole group, thiazole group, thiadiazole group, oxadiazole group, etc.), substituent As an electron-withdrawing substituent or an electron-donating substituent.

^{R 1, R 2, R 3} , R 4, preferably R ^5, R ^6, at least 1 Tsuga耐diffusible group or adsorptive group substituents selected from R ⁷ and R ^8, especially R ² A diffusion-resistant group or an adsorptive group is preferable.

  The non-diffusible group is also called a ballast group, and is preferably an aliphatic group having 6 or more carbon atoms or an aryl group into which an alkyl group having 3 or more carbon atoms is introduced. Diffusion resistance varies depending on the amount of binder and cross-linking agent used, but by introducing a diffusion-resistant group, the intramolecular movement distance at room temperature is suppressed, and the reaction over time can be suppressed.

  The epoxy compound that can be used as the crosslinking agent is not particularly limited as long as it has one or more epoxy groups and the number of epoxy groups, molecular weight, and the like. The epoxy group is preferably contained in the molecule as a glycidyl group via an ether bond or an imino bond. Moreover, any of a monomer, an oligomer, a polymer, etc. may be sufficient as an epoxy compound, and the number of the epoxy groups which exist in a molecule | numerator is about 1-10 normally, Preferably it is 2-4. When the epoxy compound is a polymer, it may be a homopolymer or a copolymer, and the particularly preferred range of the number average molecular weight Mn is about 2000 to 20000.

  As an epoxy compound, the compound represented by the following general formula (EP) is preferable.

In the general formula (EP), the substituent of the alkylene group represented by R is preferably a group selected from a halogen atom, a hydroxyl group, a hydroxyalkyl group, or an amino group. The linking group represented by R preferably has an amide linking moiety, an ether linking moiety, or a thioether linking moiety. -SO ₂ The divalent linking group represented by _{X -, - SO 2 NH -} , - S -, - O-, or -NR ₁ - is preferred. Here, R ₁ is a monovalent group and is preferably an electron withdrawing group.

These epoxy compounds may be used alone or in combination of two or more. The addition amount is not particularly limited, but is preferably in the range of 1 × 10 ⁻⁶ to 1 × 10 ⁻² mol / m ² , more preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol / m ² . It is.

  The epoxy compound can be added to any layer on the photosensitive layer side of the support, such as a photosensitive layer, surface protective layer, intermediate layer, antihalation layer, subbing layer, etc., and one or more of these layers can be added. Can be added. Further, it can be added to any layer on the opposite side of the support from the photosensitive layer. In addition, any layer may be sufficient in the type of photosensitive material in which a photosensitive layer exists on both surfaces.

  An acid anhydride is a compound having at least one acid anhydride group represented by the following structural formula.

-CO-O-CO-
The acid anhydride is not particularly limited as long as it has one or more acid anhydride groups, and the number, molecular weight, and the like of the acid anhydride groups are not limited, but a compound represented by the following general formula (SA) is preferable.

  In the general formula (SA), Z represents a group of atoms necessary for forming a monocyclic or polycyclic system. These ring systems may be unsubstituted or substituted. Examples of substituents include alkyl groups (eg, methyl, ethyl, hexyl), alkoxy groups (eg, methoxy, ethoxy, octyloxy), aryl groups (eg, phenyl, naphthyl, tolyl), hydroxyl groups, aryloxy groups (Eg, phenoxy), alkylthio group (eg, methylthio, butylthio), arylthio group (eg, phenylthio), acyl group (eg, acetyl, propionyl, butyryl), sulfonyl group (eg, methylsulfonyl, phenylsulfonyl), acylamino group Sulfonylamino group, acyloxy group (for example, acetoxy, benzoxy), carboxyl group, cyano group, sulfo group, and amino group. As the substituent, those not containing a halogen atom are preferable.

These acid anhydrides may be used alone or in combination of two or more. The addition amount is not particularly limited, but is preferably in the range of 1 × 10 ⁻⁶ to 1 × 10 ⁻² mol / m ² , more preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol / m ² . It is.

  In the present invention, the acid anhydride can be added to any layer on the photosensitive layer side of the support, such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer, and an undercoat layer, and one of these layers or It can be added to two or more layers. Moreover, you may add to the same layer as the said epoxy compound.

(Color adjustment)
Next, the color tone of an image obtained by heat developing the imaging material will be described.

  Regarding the color tone of an output image for medical diagnosis such as a conventional X-ray photographic film, it is said that a cold tone image tone is easier for a reader to obtain a more accurate diagnostic observation result of a recorded image. Here, a cool image tone is a pure black tone or a bluish black tone with a black image, and a warm image tone is a black tone with a brown tone. However, in order to allow a more precise quantitative discussion, the following explanation is based on the expression recommended by the International Commission on Illumination (CIE).

Terminology of color "more Hiyacho" and "more temperature control" can be represented by the hue angle h _ab at the lowest density Dmin and optical density D = 1.0. That is, the hue angle h _ab represents the color coordinates a ^* and b ^* of the color space L ^* a ^* b ^* color space, which is a color space having a perceptually uniform rate recommended by the International Commission on Illumination (CIE) in 1976. Using the following formula.

h _ab = tan ⁻¹ (b ^* / a ^* )
As a result of the examination based on the expression method based on the hue angle, the color tone after development of the silver salt photothermographic imaging material according to the present invention preferably has a hue angle _hab range of 180 degrees < _hab <270 degrees. More preferably, it was found that 200 degrees < _hab <270 degrees, and most preferably 220 degrees < _hab <260 degrees. This is disclosed in Japanese Patent Application Laid-Open No. 2002-6463.

Conventionally, the CIE 1976 (L ^* u ^* v ^* ) color space or the (L ^* a ^* b ^* ) color space in the vicinity of an optical density of 1.0 is specified as u ^* , v ^* or a ^* , b ^* . It is known that a diagnostic image having a preferable visual color tone can be obtained by adjusting the numerical value, and is described in, for example, Japanese Patent Application Laid-Open No. 2000-29164.

As a result of further intensive studies on the silver salt photothermographic imaging material according to the present invention, the horizontal axis is u ^{* in} the CIE 1976 (L ^* u ^* v ^* ) color space or (L ^* a ^* b ^* ) color space. When a linear regression line is created by plotting u ^* , v ^* or a ^* , b ^* at various photographic densities on a graph with a ^* and the vertical axis representing v ^* or b ^* , the linear regression line is plotted. It was found that by adjusting the value to a specific range, it has a diagnostic ability equal to or higher than that of the conventional wet silver salt light-sensitive material. In the following, the condition range of the present invention will be described.

The optical density of the imaging material is measured at 0.5, 1.0, 1.5 and the lowest optical density. The horizontal axis of the CIE 1976 (L ^* a ^* b ^* ) color space is a ^* , and the vertical axis is the two-dimensional coordinate in terms of the b ^*, a ^* in the above each optical density, coefficient of determination of the linear regression line that created arranged b ^* (multiple determination) R ² is 1.000 or less than 0.998.

Furthermore, the b ^* value of the intersection with the vertical axis of the linear regression line is −5 or more and 5 or less, and the slope (b ^* / a ^* ) is 0.7 or more and 2.5 or less.

Note that the linear regression line determination coefficient (multiple determination) R ² created by arranging u ^* and v ^* at each optical density is 0.998 or more and 1.000 or less, and the vertical line of the linear regression line is vertical. The v ^* value at the intersection with the axis is preferably −5 or more and 5 or less, and the slope (v ^* / u ^* ) is preferably 0.7 or more and 2.5 or less.

Next, an example of a method for creating the above-described linear regression line, that is, a method for measuring u ^* , v ^* and a ^* , b ^{* in} the CIE 1976 color space will be described.

A four-stage wedge sample including an unexposed portion and optical densities of 0.5, 1.0, and 1.5 is prepared using a heat development apparatus. Each wedge density part thus produced is measured with a spectrocolorimeter (example: CM-3600d; manufactured by Minolta Co., Ltd.) to calculate u ^* , v ^* or a ^* , b ^* . The measurement conditions at that time are F7 light source as the light source, the viewing angle is 10 °, and measurement is performed in the transmission measurement mode. Plot u ^* , v ^*, a ^* , b ^* measured on a graph with u ^* or a ^{* on} the horizontal axis and v ^* or b ^{* on the} vertical axis to obtain a linear regression line and determine coefficient (multiple determination) R ² Find the intercept and slope.

  Next, a specific method for obtaining a linear regression line having the above characteristics will be described.

  In the present invention, the developed silver shape is adjusted by adjusting the addition amount of the above-described toning agent, developer, silver halide grains, and compounds such as aliphatic carboxylic acid silver which are directly and indirectly involved in the development reaction process. Optimized and preferred color tone. For example, when the developed silver shape is dendritic, it becomes a bluish direction, and when it is a filament shape, it becomes a yellowish direction. That is, it can be adjusted in consideration of the tendency of the developed silver shape.

  Conventionally, phthalazinone or phthalazine and phthalic acids and phthalic anhydrides are generally used as toning agents. Examples of suitable toning agents are RD17029, U.S. Pat. Nos. 4,123,282, 3,994,732, 3,846,136, and 4,021,249. Is disclosed.

  In addition to such a toning agent, it is preferable to adjust the color tone using a coupler disclosed in JP-A-11-288057, EP11334611A2, etc. and a leuco dye described in detail below.

  Further, by using silver halide grains that are converted into the internal latent image type after heat development according to the present invention, it is possible to unexpectedly prevent color tone fluctuations during storage of silver images.

[Leuco dye]
A leuco dye is used in the silver salt photothermographic dry imaging material of the present invention.

  The leuco dye is preferably any colorless or slightly colored compound that is oxidized to a colored form when heated at a temperature of about 80-200 ° C. for about 0.5-30 seconds and is oxidized by silver ions. Any leuco dye that forms a pigment can be used. Compounds that are pH sensitive and can be oxidized to a colored state are useful.

  Representative leuco dyes suitable for use in the present invention are not particularly limited. And phenothiazine leuco dye. Also useful are U.S. Pat. Nos. 3,445,234, 3,846,136, 3,994,732, 4,021,249, 4,021,250, 4 No. 4,022,617, No. 4,123,282, No. 4,368,247, No. 4,461,681, and JP-A-50-36110, No. 59-206931, JP-A-5-204087. No. 11-231460, JP-A Nos. 2002-169249, 2002-236334, and the like.

  In order to adjust to a predetermined color tone, it is preferable to use leuco dyes of various colors singly or in combination of a plurality of types. In the present invention, the color tone is excessively yellowish with the use of a highly active reducing agent, or the image is excessively high at a high density portion of 2.0 or more by using fine silver halide. It is preferable to use a leuco dye that develops in cyan to prevent redness, but a yellow leuco dye and other leuco dyes that develop in cyan are also used for fine-tuning the color tone. It is preferable to do this.

  The color density is preferably adjusted appropriately in relation to the color tone of the developed silver itself. In the present invention, the sum of the maximum densities at the absorption maximum wavelength of the dye image formed by the leuco dye is usually 0.01 or more and 0.30 or less, preferably 0.02 or more and 0.20 or less, particularly preferably 0.02 or more. It is preferable to adjust the color tone so that the color is developed so as to have a value of 0.10 or less and an image having a preferable color tone range described later is obtained.

(Yellow coloring leuco dye)
In the present invention, a color image forming agent represented by the following general formula (YL), which increases the absorbance at 360 to 450 nm when oxidized, is particularly preferably used as a yellow coloring leuco dye.

  Hereinafter, the compound represented by formula (YL) will be described in detail.

In the general formula (YL), the alkyl group represented by R ₁ is preferably an alkyl group having 1 to 30 carbon atoms, and may have a substituent. Specifically, methyl, ethyl, butyl, octyl, i-propyl, t-butyl, t-octyl, t-pentyl, sec-butyl, cyclohexyl, 1-methyl-cyclohexyl and the like are preferable, and steric rather than i-propyl. Is preferably a large group (i-propyl, i-nonyl, t-butyl, t-amyl, t-octyl, cyclohexyl, 1-methyl-cyclohexyl, adamantyl, etc.), and among them, secondary or tertiary alkyl Group is preferable, and tertiary alkyl groups such as t-butyl, t-octyl, and t-pentyl are particularly preferable. Examples of the substituent that R ₁ may have include a halogen atom, an aryl group, an alkoxy group, an amino group, an acyl group, an acylamino group, an alkylthio group, an arylthio group, a sulfonamide group, an acyloxy group, an oxycarbonyl group, and a carbamoyl group. , Sulfamoyl group, sulfonyl group, phosphoryl group and the like.

R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group or an acylamino group, respectively. The alkyl group represented by R ₂ is preferably an alkyl group having 1 to 30 carbon atoms, and the acylamino group is preferably an acylamino group having 1 to 30 carbon atoms. Among these, the description of the alkyl group is the same as that for R ₁ .

The acylamino group represented by R ₂ may be unsubstituted or substituted, and specific examples include an acetylamino group, an alkoxyacetylamino group, and an aryloxyacetylamino group. R ₂ is preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 24 carbon atoms, and specific examples include methyl, i-propyl, and t-butyl. R ₁ and R ₂ are not 2-hydroxyphenylmethyl groups.

R ₃ represents a hydrogen atom or a substituted or unsubstituted alkyl group. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, and the description of the alkyl group is the same as that for R ₁ . R ₃ is preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 24 carbon atoms, and specific examples include methyl, i-propyl, t-butyl and the like. Further, it is preferable either R _12, R ₁₃ is a hydrogen atom.

R ₄ represents a group capable of substituting on the benzene ring and is, for example, the same group as described for the substituent R ₄ in the general formula (RED). R ₄ is preferably a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or an oxycarbonyl group having 2 to 30 carbon atoms, more preferably an alkyl group having 1 to 24 carbon atoms. Examples of the substituent of the alkyl group include an aryl group, an amino group, an alkoxy group, an oxycarbonyl group, an acylamino group, an acyloxy group, an imide group, and a ureido group, and more preferable examples include an aryl group, an amino group, an oxycarbonyl group, and an alkoxy group. preferable. These alkyl group substituents may be further substituted with these substituents.

  Next, among the compounds represented by the general formula (YL), a compound (bisphenol compound) preferably used in the present invention is represented by the following formula.

In the formula, Z represents —S— or —C (R ₁ ) (R ₁ ′) —, and R ₁ and R ₁ ′ each represents a hydrogen atom or a substituent. Examples of the substituent represented by R ₁ and R ₁ ′ include the same groups as the substituents exemplified in the description of R _{1 in} the general formula (RED). R ₁ and R ₁ ′ are preferably a hydrogen atom or an alkyl group.

R ₂ , R ₃ , R ₂ ′ and R ₃ ′ each represent a substituent, and examples of the substituent include the same groups as those described for R ₂ and R ₃ in the general formula (RED).

R ₂ , R ₃ , R ₂ ′ and R ₃ ′ are preferably an alkyl group, alkenyl group, alkynyl group, aryl group or heterocyclic group, with an alkyl group being more preferred. Examples of the substituent on the alkyl group include the same groups as those described in the description of the substituent in the general formula (RED).

R ₂ , R ₃ , R ₂ ′ and R ₃ ′ are more preferably tertiary alkyl groups such as t-butyl, t-pentyl, t-octyl and 1-methyl-cyclohexyl.

R ₄ and R ₄ ′ each represent a hydrogen atom or a substituent, and examples of the substituent include the same groups as those described in the description of R ₄ in the general formula (RED).

  Examples of the compound represented by the general formula (YL) (bisphenol compound) include compounds (II-1) to (II-40) described in paragraphs “0032” to “0038” of JP-A No. 2002-169249, EP1 , 211,093, the compounds (ITS-1) to (ITS-12) described in paragraph [0026].

  Specific examples of the compound represented by the general formula (YL) are shown below, but the present invention is not limited thereto.

  The addition amount of the compound represented by the general formula (YL) is usually 0.00001 to 0.01 mol, preferably 0.0005 to 0.01 mol, more preferably 0.001 to 1 mol per 1 mol of silver. 0.008 mol.

(Cyan coloring leuco dye)
Next, the cyan color-forming leuco dye will be described. In the present invention, a color image forming agent that increases its absorbance at 600 to 700 nm when oxidized is particularly preferably used as a cyan color developing dye. JP-A-59-206831 (especially, λmax is 600 to 700 nm). And compounds of general formula (I) to general formula (IV) in JP-A-5-204087 (specifically, (1) to (18) described in paragraphs “0032” to “0037”) ) And compounds of general formula 4 to general formula 7 of JP-A No. 11-231460 (specifically, compounds of No. 1 to No. 79 described in paragraph “0105”).

  The cyan color-forming leuco dye particularly preferably used in the present invention is represented by the following general formula (CL).

In the formula, R ₁ and R ₂ are hydrogen atom, halogen atom, substituted or unsubstituted alkyl group, alkenyl group, alkoxy group, NHCO-R ₁₀ group in which R ₁₀ is an alkyl group, aryl group or heterocyclic group. Or R ₁ and R ₂ are groups which are bonded to each other to form an aliphatic hydrocarbon ring, an aromatic hydrocarbon ring or a heterocyclic ring. A is a —NHCO— group, —CONH— group or —NHCONH— group, R ₃ is a substituted or unsubstituted alkyl group, aryl group or heterocyclic group, or —A—R ₃ is a hydrogen atom. , W is a hydrogen atom or —CONH—R ₅ group, —CO—R ₅ group or —CO—O—R ₅ group, wherein R ₅ is a substituted or unsubstituted alkyl group, aryl group or heterocyclic group, R ₄ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a carbamoyl group, or a nitrile group. R ₆ is a —CONH—R ₇ group, a —CO—R ₇ group or a —CO—O—R ₇ group, wherein R ₇ is a substituted or unsubstituted alkyl group, aryl group or heterocyclic group. X represents a substituted or unsubstituted aryl group or heterocyclic group.

In the general formula (CL), fluorine, bromine, chlorine, etc. as halogen atoms, alkyl groups having up to 20 carbon atoms (methyl, ethyl, butyl, dodecyl etc.) as alkyl groups, and alkenyl groups having carbon atoms Up to 20 alkenyl groups (vinyl, allyl, butenyl, hexenyl, hexadienyl, ethenyl-2-propenyl, 3-butenyl, 1-methyl-3-propenyl, 3-pentenyl, 1-methyl-3-butenyl, etc.), alkoxy groups Is an alkoxy group having up to 20 carbon atoms (methoxy, ethoxy, etc.), an aryl group is a group having 6 to 20 carbon atoms such as phenyl, naphthyl, thienyl, and a heterocyclic group is thiophene, furan, imidazole. , Pyrazole, pyrrole and the like. A is a —NHCO— group, —CONH— group or —NHCONH— group, and R ₃ is a substituted or unsubstituted alkyl group (preferably up to 20 carbon atoms such as methyl, ethyl, butyl, dodecyl), an aryl group (preferably phenyl with 6 to 20 carbon atoms is, naphthyl, thienyl, etc.) or a Hajime Tamaki (thiophene, furan, imidazole, pyrazole, or pyrrole, etc.), or -A-R _3, is a hydrogen atom, W is a hydrogen atom Or R ₅ is a substituted or unsubstituted alkyl group (preferably up to 20 carbon atoms such as methyl, ethyl, butyl, dodecyl, etc.), aryl group (preferably having 6 to 20 carbon atoms such as phenyl, naphthyl, thienyl, etc.) or heterocyclic ring —CONH—R ₅ group, —CO—R ₅ group or —CO, which is a group (thiophene, furan, imidazole, pyrazole, pyrrole, etc.) —O—R ₅ group, wherein R ₄ is a hydrogen atom, a halogen atom (eg, fluorine, chlorine, bromine, iodine), a chain or cyclic alkyl group (eg, methyl group, butyl group, dodecyl group, cyclohexyl group). Etc.), alkoxy groups (for example, methoxy group, butoxy group, tetradecyloxy group, etc.), carbamoyl groups (for example, diethylcarbamoyl group, phenylcarbamoyl group, etc.), or nitrile groups are preferable, and among these, hydrogen atom, alkyl Groups are more preferred. R ₁ and R ₂ , R ₃ and R ₄ may be linked to each other to form a ring structure. The above groups may further have a single substituent or a plurality of substituents. For example, typical substituents that can be introduced into an aryl group include halogen atoms (fluorine, chlorine, bromine, etc.), alkyl groups ( Methyl, ethyl, propyl, butyl, dodecyl, etc.), hydroxyl group, cyano group, nitro group, alkoxy group (methoxy, ethoxy, etc.), alkylsulfonamide group (methylsulfonamide, octylsulfonamide, etc.), arylsulfonamide group (phenyl) Sulfonamides, naphthylsulfonamides, etc.), alkylsulfamoyl groups (butylsulfamoyl etc.), arylsulfamoyls (phenylsulfamoyl etc.), alkyloxycarbonyl groups (methoxycarbonyl etc.), aryloxycarbonyl groups (phenyl) Oxycarbonyl, etc.), aminosulfone Bromide group, an acylamino group, a carbamoyl group, a sulfonyl group, a sulfinyl group, a sulfoxy group, a sulfo group, an aryloxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group include an amino group. Two different groups of these groups can be introduced into the aryl group. R ₁₀ or R ₈₅ is preferably a phenyl group, more preferably a phenyl group having a plurality of substituents including a halogen atom and a cyano group.

R ₆ is (methyl up to several preferably 20 carbon atoms, ethyl, butyl, dodecyl, etc.) R ₇ is a substituted or unsubstituted alkyl group, (phenyl preferably 6 to 20 carbon atoms, naphthyl, thienyl, etc.) an aryl group or A —CONH—R ₇ group, a —CO—R ₇ group or a —CO—O—R ₇ group which is a heterocyclic group (thiophene, furan, imidazole, pyrazole, pyrrole, etc.). As the substituent for the alkyl group represented by R _7, the same substituents as those for R _{1 to} R ₄ can be used. X ₈ represents a substituted or unsubstituted aryl group or heterocyclic group. Examples of the aryl group include groups having 6 to 20 carbon atoms such as phenyl, naphthyl, and thienyl, and examples of the heterocyclic group include thiophene, furan, imidazole, pyrazole, and pyrrole. As the substituent that the group represented by X can have, the same substituents as those in R _{1 to} R ₄ can be used. The group represented by X is preferably an aryl group or a heterocyclic group substituted with an alkylamino group (such as a diethylamino group) at the para position. These may contain photographically useful groups.

  Specific examples of the cyan chromogenic leuco dye (CL) are shown below, but are not limited thereto.

  The addition amount of the cyan coloring leuco dye is usually 0.00001 to 0.05 mol / Ag1 mol, preferably 0.0005 to 0.02 mol / Ag1 mol, more preferably 0.001 to 0.01 mol. / Ag1 mol.

  As a method for adding the compound represented by the general formula (YL) and the cyan color-forming leuco dye, it can be added in the same manner as the method for adding the reducing agent represented by the general formula (RED), You may make it contain in a coating liquid by arbitrary methods, such as an emulsified dispersion form and a solid fine particle dispersion form, and may make it contain in a photosensitive material.

  The compound of the general formula (YL) and the cyan color-forming leuco dye are preferably contained in an image forming layer containing an organic silver salt, but one is in the image forming layer and the other is adjacent to the image forming layer. You may make it contain in a forming layer, and may make both contain in a non-image forming layer. When the image forming layer is composed of a plurality of layers, they may be contained in separate layers.

[Others]
Examples of the support material used in the silver salt photothermographic dry imaging material of the present invention include various polymer materials, glass, wool cloth, cotton cloth, paper, metal (for example, aluminum), etc. In terms of handling, a material that can be processed into a flexible sheet or roll is suitable. Therefore, as a support in the silver salt photothermographic dry imaging material of the present invention, a plastic film (for example, cellulose acetate film, polyester film, polyethylene terephthalate film, polyethylene naphthalate film, polyamide film, polyimide film, cellulose triacetate film, polycarbonate film, etc.) In the present invention, a biaxially stretched polyethylene terephthalate film is particularly preferable. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.

  In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be included in the constituent layers in order to improve the chargeability. These may be contained in any layer, but are preferably contained in the undercoat layer, the backing layer, the layer between the photosensitive layer and the undercoat, and the like. In the present invention, the conductive compounds described in US Pat. No. 5,244,773, columns 14 to 20 are preferably used.

  The silver salt photothermographic dry imaging material of the present invention has at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. For example, a protective layer is provided on the photosensitive layer, and a back coat layer is provided on the opposite side of the support to prevent sticking between the photosensitive materials or in the photosensitive material roll. Preferably it is provided. Binders used in these protective layers and backcoat layers have a glass transition point higher than that of the heat-developable layer, and polymers such as scratches and deformations, such as cellulose acetate and cellulose acetate butyrate, are the above-mentioned binders. It is chosen from among them. For gradation adjustment, etc., in the present invention, it is preferable that the photosensitive layer comprises two or more layers. For example, two or more photosensitive layers may be provided on one side of the support, or both sides of the support may be provided. One or more layers may be installed.

  In the silver salt photothermographic dry imaging material of the present invention, a filter layer is formed on the same side as or opposite to the photosensitive layer in order to control the amount of light transmitted through the photosensitive layer or the wavelength distribution, or a dye is formed on the photosensitive layer. Or it is preferable to contain a pigment.

  As the dye used, known compounds that absorb light in various wavelength regions can be used depending on the color sensitivity of the photosensitive material.

  For example, when the silver salt photothermographic dry imaging material of the present invention is used as an image recording material by infrared light, a squarylium dye having a thiopyrylium nucleus as disclosed in Japanese Patent Application No. 11-255557 (this specification) Used as a thiopyrylium squarylium dye) and a squarylium dye having a pyrylium nucleus (referred to herein as a pyrylium squarylium dye), or a thiopyrylium croconium dye similar to a squarylium dye, or a pyrylium croconium dye. It is preferable to do.

  The compound having a squarylium nucleus is a compound having 1-cyclobutene-2-hydroxy-4-one in the molecular structure, and the compound having a croconium nucleus is 1-cyclopentene-2-hydroxy- in the molecular structure. It is a compound having 4,5-dione. Here, the hydroxyl group may be dissociated. Hereinafter, in the present specification, these pigments are collectively referred to as squarylium dyes for convenience.

  As the dye, a compound described in JP-A-8-201959 is also preferable.

[Layer structure and coating conditions]
The silver salt photothermographic dry imaging material of the present invention is formed by preparing a coating solution in which the above-described constituent layers are dissolved or dispersed in a solvent, coating the coating solution on the support, and performing a heat treatment. The The coating solution for forming the photosensitive layer preferably contains 30% by mass or more of water, more preferably 50% by mass or more, and although there is no particular upper limit, it is preferable that the amount of the solvent is smaller from the viewpoint of environmental load. It is preferable that all the solvents are water. In the present invention, it is preferable that a plurality of these coating liquids are simultaneously applied in layers, followed by heat treatment. Here, "multiple simultaneous multi-layer coating" means that a coating solution for each constituent layer (for example, a photosensitive layer and a protective layer) is prepared, and when coating this onto a support, each layer is individually coated and dried repeatedly. In other words, it means that each constituent layer can be formed in such a state that the multilayer coating and drying can be performed simultaneously. That is, the upper layer is provided before the remaining amount of the total solvent in the lower layer reaches 70% by mass or less.

  There are no particular restrictions on the method of applying multiple layers of each constituent layer simultaneously, and for example, a known method such as a bar coater method, curtain coating method, dipping method, air knife method, hopper coating method, or extrusion coating method may be used. Can do. Of these, a pre-weighing type coating method called an extrusion coating method is more preferable. Since the extrusion coating method does not volatilize on the slide surface unlike the slide coating method, it is suitable for precision coating and organic solvent coating. Although this coating method has been described on the side having the photosensitive layer, the same applies to the case of coating with undercoating when providing the backcoat layer.

In the present invention, the silver coating amount is preferably 0.5 g / m ² or more and 2.0 g / m ² or less, more preferably 1.0 g / m ² or more and 1.5 g / m ² or less.

In the present invention, the silver equivalent of silver halide grains having a grain size of 0.030 μm or more and 0.055 μm or less in the silver halide grain emulsion has a silver coating amount of 0.5 g / m ² or more and 1.5 g. It is preferably 3% or more and 15% or less in the range of / m ² or less.

  Among the applied silver amount, those derived from silver halide preferably occupy 2 to 18%, more preferably 3 to 15%, based on the total silver amount.

In the present invention, the coating density of silver halide grains of 0.01 μm or more (equivalent particle diameter equivalent to sphere) is preferably 1 × 10 ¹⁴ particles / m ² or more and 1 × 10 ¹⁸ particles / m ² or less. Furthermore, 1 × 10 ¹⁵ pieces / m ² or more and 1 × 10 ¹⁷ pieces / m ² or less are preferable.

Furthermore, the coating density of the aliphatic carboxylic acid silver salt of the present invention is 10 ⁻¹⁷ g or more, 10 ⁻¹⁵ g or less, more preferably 10 μg per silver halide grain of 0.01 μm or more (equivalent particle diameter equivalent to sphere). ^-16 g or more and 10 ^-14 g or less is preferable.

  When coated under the conditions within the above range, it is preferable from the viewpoint of the optical maximum density of the silver image per fixed coated silver amount, that is, the silver coating amount (covering power) and the color tone of the silver image. Results are obtained.

(Image recording method)
In the present invention, the development conditions vary depending on the equipment, apparatus, or means used, but typically the heating of the imagewise exposed silver salt photothermographic dry imaging material at a suitable high temperature is required. Accompany. The latent image obtained after the exposure is obtained at a moderately high temperature (for example, about 80 to 200 ° C., preferably about 100 to 200 ° C.) for a sufficient time (generally about 1 second to about 2 minutes). The dry imaging material can be developed by heating.

  When the heating temperature is 80 ° C. or lower, sufficient image density cannot be obtained in a short time. When the heating temperature is 200 ° C. or higher, the binder is melted, and not only the image itself, such as transfer to a roller, but also adversely affects the transportability and the developing machine. Effect. By heating, a silver image is generated by an oxidation-reduction reaction between an organic silver salt (which functions as an oxidizing agent) and a reducing agent. This reaction process proceeds without any supply of treatment liquid such as water from the outside.

  The apparatus, device, or means for heating may be performed by a heating means typical as a heat generator using a hot plate, an iron, a hot roller, carbon, white titanium, or the like. More preferably, in the silver salt photothermographic dry imaging material provided with the protective layer according to the present invention, the surface on the side having the protective layer is brought into contact with the heating means for the heat treatment. It is preferable from the viewpoints of thermal efficiency, workability, and the like, and it is preferable that the surface is conveyed while being in contact with a heat roller, heated and developed.

  The silver salt photothermographic dry imaging material of the present invention is preferably processed at a conveyance speed of 30 mm / sec or more during thermal development from the viewpoint of sufficiently achieving the object effects of the present invention, and processed at 30 to 150 mm / sec. More preferably.

  In the exposure of the silver salt photothermographic dry imaging material of the present invention, it is desirable to use a light source suitable for the color sensitivity imparted to the photosensitive material. For example, in the case where the light-sensitive material can be felt by infrared light, it can be applied to any light source as long as it is in the infrared light range, but the laser power is high and the photosensitive material can be transparent. In view of the above, an infrared semiconductor laser (780 nm, 820 nm) is more preferably used.

  In the present invention, the exposure is preferably performed by laser scanning exposure, but various methods can be adopted as the exposure method. For example, as a first preferred method, there is a method using a laser scanning exposure machine in which the angle formed by the exposure surface of the photosensitive material and the scanning laser beam is not substantially perpendicular.

  Here, “substantially not perpendicular” means that the angle closest to the vertical during laser scanning is preferably 55 ° to 88 °, more preferably 60 ° to 86 °, and even more preferably 65 °. It is at least 84 degrees and most preferably 70 degrees to 82 degrees.

  The beam spot diameter on the exposed surface when laser light is scanned onto the silver salt photothermographic dry imaging material is preferably 200 μm or less, more preferably 100 μm or less. This is preferable in that a smaller spot diameter can reduce the angle of deviation of the laser incident angle from the vertical. The lower limit of the beam spot diameter is 10 μm. By performing such laser scanning exposure, it is possible to reduce image quality deterioration related to reflected light such as generation of interference fringe-like unevenness.

  As a second method, the exposure in the present invention is also preferably performed using a laser scanning exposure machine that emits a scanning laser beam that is a vertical multi. Compared with a single longitudinal mode scanning laser beam, image quality degradation such as generation of interference fringe-like unevenness is reduced.

  In order to make it vertically multi-ply, a method such as using return light by combining or applying high-frequency superposition is preferable. The vertical multi means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

  Furthermore, as a third method, it is also preferable to form an image by scanning exposure using two or more lasers.

  As such an image recording method using a plurality of lasers, it is used in an image writing means of a laser printer or a digital copying machine which writes an image line by line in one scanning because of a demand for high resolution and high speed. This technique is known, for example, from Japanese Patent Laid-Open No. 60-166916. This is a method in which laser light emitted from a light source unit is deflected and scanned by a polygon mirror and imaged on a photoconductor via an fθ lens or the like. This is the same laser scanning optical apparatus in principle as a laser imager or the like. It is.

  The image formation of laser light on the photoconductor in the image writing means of laser printers and digital copiers is for the purpose of writing images line by line in one scan, and one line from the image formation position of one laser light. The next laser beam is imaged by shifting. Specifically, the two light beams are close to each other in the sub-scanning direction on the image plane with an interval of the order of several tens of μm, and the print density is 400 dpi (in the present invention, 1 inch per inch, that is, 1 per 2.54 cm). The dot printing density is defined as dpi (dot per inch), and the sub-scanning direction pitch of the two beams is 63.5 μm, and 600 dpi is 42.3 μm. Unlike the method of shifting the resolution in the sub-scanning direction as described above, the present invention is characterized in that two or more lasers are focused on the exposure surface at the same place to change the incident angle to form an image. In this case, when the exposure energy on the exposure surface when writing with one ordinary laser (wavelength λ [nm]) is E, N lasers used for exposure have the same wavelength (wavelength λ [nm]. ]), The same exposure energy (En) is preferably in the range of 0.9 × E ≦ En × N ≦ 1.1 × E. By doing so, energy is secured on the exposure surface, but the reflection of each laser beam to the image forming layer is reduced because the exposure energy of the laser is low, and thus the occurrence of interference fringes is suppressed.

  In the above description, a plurality of lasers having the same wavelength as λ are used. However, lasers having different wavelengths may be used. In this case, it is preferable that (λ−30) <λ1, λ2,... Λn ≦ (λ + 30) is satisfied with respect to λ [nm].

In the above-described image recording methods of the first, second, and third aspects, the laser used for scanning exposure is generally well-known solid laser such as ruby laser, YAG laser, glass laser; Ne laser, Ar ion laser, Kr ion laser, CO ₂ laser, CO laser, He—Cd laser, N ₂ laser, excimer laser and other gas lasers; InGaP laser, AlGaAs laser, GaAsP laser, InGaAs laser, InAsP laser, CdSnP ₂ laser, a semiconductor laser such as GaSb laser; chemical laser, but a dye laser or the like in accordance with the application can be used by properly selected from these maintenance and light source size of the problem among the semiconductor laser wavelength 600~1200nm It is preferable to use. In a laser used in a laser imager or a laser image setter, the beam spot diameter on the exposed surface of a material when scanned with a photothermographic material is generally 5 to 75 μm as a minor axis diameter and as a major axis diameter. The laser beam scanning speed can be set to an optimum value for each photosensitive material depending on the sensitivity and laser power at the laser oscillation wavelength unique to the photothermographic material.

In the present invention, the silver salt photothermographic dry imaging material preferably contains a solvent in the range of 5 to 1000 mg / m ² at the time of development. Preferably, it is preferably prepared so as to be 100 to 500 mg, whereby a photosensitive material with high sensitivity, low fog and high maximum density is obtained.

  Examples of the solvent in the present invention include ketones such as acetone, methyl ethyl ketone, and isophorone, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, and benzyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, Glycols such as hexylene glycol, ether alcohols such as ethylene glycol monomethyl ether and diethylene glycol monoethyl ether, ethers such as isopropyl ether, esters such as ethyl acetate and butyl acetate, chlorides such as methylene chloride and dichlorobenzene And hydrocarbons. Others include water, formamide, dimethylformamide, toluidine, tetrahydrofuran, acetic acid and the like. However, it is not limited to these. These solvents can be used alone or in combination of several kinds.

  The content of the solvent in the photosensitive material can be adjusted by changing conditions such as temperature conditions in the drying step after the coating step. Further, the content of the solvent can be measured by gas chromatography under conditions suitable for detecting the contained solvent.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1
<< Preparation of Photographic Support >>
After applying a corona discharge treatment of 0.5 kV · A · min / m ² to one surface of a polyethylene terephthalate film base (thickness: 175 μm) colored blue to a concentration of 0.170, the following undercoat coating solution is applied to the surface. The undercoat layer A was coated using A-1 so as to have a dry film thickness of 0.2 μm. Furthermore, after the other surface was similarly subjected to a corona discharge treatment of 0.5 kV · A · min / m ² , the following undercoat coating liquids B-1 and A-1 were used for the undercoat. Layers B and A were coated so that the dry film thickness was 0.1 μm and 0.2 μm, respectively. Thereafter, heat treatment was performed at 130 ° C. for 15 minutes in a heat treatment type oven having a film transport device composed of a plurality of roll groups.

[Undercoat coating liquid A-1]
270 g of copolymer latex liquid (solid content 30%) of butyl acrylate 40% by mass, t-butyl acrylate 10% by mass, styrene 25% by mass, and 2-hydroxyethyl acrylate 25% by mass and compound (UL-1) 0. 6 g and 1 g of methylcellulose were mixed. Furthermore, 1.3 g of silica particles (Syloid 350, manufactured by Fuji Silysia) was previously ultrasonically dispersed in 100 g of water (manufactured by Alex Corporation, trade name: Ultrasonic Generator, frequency 25 kHz, 600 W). The liquid which had been dispersed for 30 minutes was added, and finally it was made up to 1000 ml with water to obtain an undercoat coating liquid A-1.

[Undercoat coating liquid B-1]
The following colloidal tin oxide dispersion 37.5 g, n-butyl acrylate 10 mass%, t-butyl acrylate 35 mass%, styrene 27 mass% and 2-hydroxyethyl acrylate 28 mass% copolymer latex liquid (solid content 30 %) 3.7 g, n-butyl acrylate 40 mass%, styrene 20 mass%, glycidyl methacrylate 40 mass% copolymer latex liquid (solid content 30%) 14.8 g and surfactant UL-1 as a coating aid 0.1 g was mixed and finished to 1000 ml with water to obtain an undercoat coating solution B-1.

<Preparation of colloidal tin oxide dispersion>
65 g of stannic chloride hydrate was dissolved in 2000 ml of a water / ethanol mixed solution to obtain a uniform solution. This was then boiled to obtain a coprecipitate. The produced precipitate is taken out by decantation and washed with distilled water many times. After confirming that there is no reaction of chlorine ions by dropping silver nitrate into the distilled water from which the precipitate has been washed, distilled water is added to the washed precipitate to make a total volume of 2000 ml. Further, 40 ml of 30% aqueous ammonia was added and heated in an aqueous solution, and then further heated and concentrated to 470 ml to obtain a colloidal tin oxide dispersion.

<Back layer side application>
[Preparation of back layer coating solution]
While stirring 830 g of methyl ethyl ketone (MEK), 84.2 g of cellulose acetate propionate (manufactured by Eastman Chemical: CAP482-20) and 4.5 g of polyester resin (Bostic: VitelPE2200B) were added and dissolved. Next, 4.5 g of a fluorine-based surfactant (Asahi Glass Co., Ltd .: Surflon KH40) dissolved in 43.2 g of methanol and 2.3 g of a fluorine-based surfactant (Dainippon Ink Co., Ltd .: MegaFag F120K) were dissolved in the dissolved liquid. Add and stir well until dissolved. Next, 2.5 g of oleyl oleate was added. Finally, 75 g of silica (average particle size: 10 μm) dispersed in MEK with a dissolver type homogenizer at a concentration of 1% was added and stirred to prepare a backcoat layer coating solution.

  The back layer coating solution prepared in this manner was applied by an extrusion coater so that the dry film thickness was 3.5 μm, and then dried for 5 minutes using a drying air having a drying temperature of 100 ° C. and a dew point temperature of 10 ° C. Thus, a sample coated with a back layer was obtained.

<< Preparation of each additive >>
[Preparation of photosensitive silver halide emulsion A-1]
370 ml of an aqueous solution containing 74 g of silver nitrate in a solution prepared by dissolving 7.5 g of ossein gelatin having an average molecular weight of 100,000 and 10 mg of potassium bromide in 900 ml of water and adjusting the temperature to 35 ° C. and pH to 3.0, (98 / 2) an aqueous solution containing potassium bromide and potassium iodide (equal molar amount in silver) and a solution containing 1 × 10 ⁻⁴ mol of iridium chloride per mol of silver while maintaining pAg 7.7. It added over 10 minutes by the double jet method. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5.0 with NaOH, and the average particle size was 0.06 μm. Cubic silver iodobromide grains having a coefficient of 12% and a [100] face ratio of 87% were obtained. This emulsion was coagulated and precipitated using a gelatin flocculant and desalted, and 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg 7.5 to obtain photosensitive silver halide emulsion A-1.

[Preparation of powdered organic silver salt A-1]
In 9450 ml of pure water, 324 g of behenic acid, 99 g of arachidic acid and 56 g of stearic acid were dissolved at 80 ° C. Next, 980 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added while stirring at high speed. Next, after adding 9.3 ml of concentrated nitric acid, the mixture was cooled to 55 ° C. and stirred for 30 minutes to contain the photosensitive silver halide emulsion A-1 (containing 0.9 mol of silver and 1400 g of water) for 5 seconds. After stirring for 5 minutes, 1470 ml of a 1 mol / L silver nitrate solution was added over 2 minutes, stirred for another 20 minutes, and water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration were repeated until the conductivity of the filtrate reached 2 μS / cm, and centrifugal dehydration was carried out, followed by drying with warm air at 37 ° C. until there was no mass loss, and powdered organic silver salt A -1 was obtained. The silver conversion rate was 89 mol%.

[Preparation of photosensitive emulsion dispersion A-1]
Dissolve 14.57 g of polyvinyl butyral powder (ESREC BL-5, manufactured by Sekisui Chemical Co., Ltd.) in 1457 g of methyl ethyl ketone, gradually add 500 g of powdered organic silver salt A-1 while stirring with a dissolver type homogenizer, and mix thoroughly. did. Thereafter, a photosensitive emulsion dispersion A-1 was obtained with a media type dispersing machine (made by Gettzmann) filled with 80% 1 mmZr beads (made by Toray Industries, Inc.) with a peripheral speed of 13 m and a residence time in the mill of 3 minutes. .

(Preparation of infrared sensitizing dye solution)
350 mg of infrared sensitizing dye 1, 13.96 g of 2-chloro-benzoic acid and 2.14 g of 5-methyl-2-mercaptobenzimidazole are dissolved in 73.4 ml of methanol in the dark, and an infrared sensitizing dye solution is obtained. Was prepared.

(Preparation of stabilizer solution)
Stabilizer solution was prepared by dissolving 1.0 g of Stabilizer 1 and 0.5 g of potassium acetate in 8.5 g of methanol.

(Preparation of developer solution)
17.74 g of developer 1 was dissolved in methyl ethyl ketone and finished to 100 ml to obtain a developer solution.

[Preparation of antifoggant solution]
Antifoggant 2 (5.81 g) was dissolved in methyl ethyl ketone and finished to 100 ml to obtain an antifoggant solution.

<Preparation of image forming layer coating solution>
50 g of the photosensitive emulsion dispersion A-1 and 15.11 g of methyl ethyl ketone were kept at 21 ° C. with stirring, 390 μl of antifoggant 1 (10% methanol solution) was added, and the mixture was stirred for 1 hour. Further, 889 μl of calcium bromide (10% methanol solution) was added and stirred for 30 minutes. Subsequently, 1.416 ml of an infrared sensitizing dye solution and 667 μl of a stabilizer solution were added and stirred for 1 hour, and then the temperature was lowered to 13 ° C. and further stirred for 30 minutes. While maintaining the temperature at 13 ° C., 13.31 g of polyvinyl butyral powder (BL-5, manufactured by Sekisui Chemical Co., Ltd.) was added and stirred for 30 minutes, and then the following additives were added at 15 minute intervals while further stirring.

Phthalazine 305mg
102g of tetrachlorophthalic acid
4-methylphthalic acid 137mg
After stirring for another 15 minutes,
Antifoggant solution (above) 5.47 ml
Developer solution (above) 14.06 ml
Were sequentially added and stirred to obtain an image forming layer coating solution 101. Next, an image forming layer coating solution 102 was prepared in the same manner except that the development accelerator-3 was added to the image forming layer coating solution 101.

<< Preparation of surface protective layer coating liquid >>
Surface protective layer coating solutions 101 to 115 having the following composition were prepared.

(Particle dispersion)
1 g of cellulose acetate butyrate (CAB171-15, manufactured by Eastman Chemical Co.) was added to 96 g of methyl ethyl ketone while stirring, and the mixture was stirred with a dissolver type stirrer until it was sufficiently dissolved. To this, 2.9 g of silica particles (Syloid 320, manufactured by Fuji Silysia) was added and dispersed at 8000 rpm for 45 minutes.

(Surface protective layer coating solution)
To 750 g of methyl ethyl ketone, 15 g of polymethyl methacrylate (Paraloid A21, manufactured by Rohm & Haas) was added and stirred for 10 minutes. Thereafter, 100 g of cellulose acetate butyrate (CAB171-15, manufactured by Eastman Chemical Co., Ltd.) was added in 4 portions while stirring, and the mixture was further stirred for 1 hour. Furthermore, 8.9 g of phthalazine, 1.5 g of vinylsulfone compound (HD-1), 0.1 g of triazine, 1.7 g of fluorosurfactant compound FS-1, and fluorosurfactant (EF-105, Toh 0.2 g of Chem Products) was added and stirred for 30 minutes. To this liquid, 85 g of the above particle dispersion was added and stirred sufficiently, and the surface protective layer coating liquid 101 was obtained with MEK at 1000 g.

  Next, in the preparation of the surface protective layer coating solution 101, the organic solid lubricant particles (metal soap) represented by the general formula (1) were added by changing the type and addition amount as shown in Table 1. Except for the above, surface protective layer coating solutions 102 to 115 were prepared in the same manner.

  In addition, 2.0 g of the compound of the general formula (1) of the present invention shown in Table 1 (that is, the organic solid lubricant particles represented by the general formula (1) of the present invention) is used as a surfactant (EF- 105, manufactured by Tochem Products Co., Ltd.) 2.0 g and cellulose acetate butyrate powder (CAB171-15, manufactured by Eastman Chemical Co., Ltd.) 2 g were dissolved in 100 g of MEK in advance by an ultrasonic disperser (manufactured by ALEX Corporation, Product name: Ultrasonic Generator (Ultrasonic Generator), frequency 25 kHz, 600 W] was used for 30 minutes, and dispersion was performed so that the types and amounts shown in Table 1 were obtained.

<Image forming layer side coating>
Using the slide coater, the image forming layer coating solution and the surface protective layer coating solution are combined in the combinations shown in Table 1 on the surface opposite to the surface coated with the back layer prepared in the examples. Was applied. At that time, the image forming layer coating solution was uniformly applied at a rate of 35 m / min so that the amount of silver applied was 1.5 g / m ² . Thereafter, drying was performed for 5 minutes using a drying air having a drying temperature of 50 ° C. and a dew point temperature of 5 ° C., followed by drying for 15 minutes using a drying air having a drying temperature of 55 ° C. and a dew point temperature of 10 ° C., thereby preparing samples 101 to 115.

<< Heat development processing and evaluation >>
[Exposure and thermal development]
From the image forming layer surface side of each sample produced as described above, exposure by laser scanning was given by an exposure machine using a semiconductor laser having a longitudinal multimode wavelength of 800 nm to 820 nm by high frequency superposition as an exposure source. At this time, an image was formed by setting the angle of the exposure surface of the sample and the exposure laser beam to 75 degrees. Note that an image with less unevenness and unexpectedly good sharpness or the like was obtained compared to the case where the angle was 90 degrees.

  Then, using an automatic developing machine having a heat drum, the surface protective layer of the sample and the drum surface were in contact with each other, and heat development was performed at 123 ° C. for 13.5 seconds. At that time, exposure and development were performed in a room adjusted to 23 ° C. and 50% RH.

<< Evaluation of each sample >>
(Measurement of dynamic friction coefficient)
The surface friction measuring device HEIDON-14 manufactured by Shinto Kagaku Co., Ltd. was used to measure the dynamic friction coefficient with the stainless steel on the back layer coating surface. At this time, the measurement surface was set to 110 ° C. with a hot plate and measured.

[Measurement of haze]
It was measured using a turbidimeter Model T-2600DA manufactured by Tokyo Denshoku Co., Ltd. and indicated in%.

[Evaluation of transportability]
The above heat development processing was continuously performed on 100 sheets of the same size. At that time, the number of conveyance failures was counted.

[Evaluation of development unevenness resistance]
For evaluation of development unevenness, a sample was prepared by exposing the entire surface with white light for about 20 seconds and then thermally developing. The degree of unevenness of the surface of this sample was visually observed, and development unevenness resistance was evaluated according to the following criteria.

5: The surface is smooth and there is no problem 4: Slight irregularities are observed, but there is no problem in practical use 3: There is unevenness in part, and there is a problem in practical use 2: Unevenness on the entire surface 1: Strong unevenness on the entire surface Table 1 shows the evaluation results.

  As is clear from the results shown in Table 1, the sample having the structure defined in the present invention has a low haze, excellent transportability and scratch resistance, little development unevenness, and even under long-time light irradiation. It can be seen that this is a silver salt photothermographic dry imaging material with little change in silver tone.

Claims (11)

In a silver salt photothermographic dry imaging material having a photosensitive layer containing an organic silver salt, photosensitive silver halide grains and a reducing agent on a support, at least one layer on the support has an average particle size of 0.5 to A silver salt photothermographic dry imaging material comprising 30 μm organic solid lubricant particles, wherein the organic solid lubricant particles are metal soap. The silver salt photothermographic dry imaging material according to claim 1, wherein the melting point of the organic solid lubricant particles is 110 ° C or higher and 200 ° C or lower. The silver salt photothermographic dry imaging material according to claim 1, wherein the organic solid lubricant particles are organic solid lubricant particles represented by the following general formula (1).
General formula (1)
_{(R 1) -COO-M-} OOC- (R 2)
[R ₁ and R ₂ each represent a substituted or unsubstituted alkyl group, alkenyl group, aralkyl group or aryl group having 2 to 60 carbon atoms, and M represents a divalent metal. R ₁ and R ₂ may be the same or different. ] The organic solid lubricant particles are particles having a solubility in a solvent of 0.5% by mass or less and an average particle size of 0.5 to 30 μm. A silver salt photothermographic dry imaging material described in 1. It has a photosensitive layer formed by coating a photosensitive emulsion containing at least an organic silver salt, photosensitive silver halide grains and a solvent, a composition containing a reducing agent and a binder, and is omitted in the photosensitive layer or non-photosensitive layer. The silver salt photothermographic dry imaging material according to claim 1, further comprising a silvering agent. By exposing to ultraviolet light or visible light, a compound that generates reactive species capable of oxidizing silver or the reducing agent is deactivated so that the silver ions of the organic silver salt cannot be reduced to silver. The silver salt photothermographic dry imaging material according to any one of claims 1 to 5, wherein the silver salt photothermographic dry imaging material contains two or more compounds capable of generating reactive active species. The image recording method to the silver salt photothermographic dry imaging material according to any one of claims 1 to 6, wherein the exposure is performed by a laser beam scanning exposure machine in which the scanning laser beam is a double beam. Image recording method. The image recording method to the silver salt photothermographic dry imaging material according to any one of claims 1 to 6, wherein exposure is performed by a laser beam scanning exposure machine in which scanning laser beams are multi-vertical. Recording method. The silver salt photothermographic dry imaging material according to any one of claims 1 to 6, wherein a hue angle hab (JIS Z 8729 standard) after heat development is 180 degrees <hab <270 degrees. . The silver salt photothermographic dry imaging according to any one of claims 1 to 6, wherein the photosensitive layer is formed using a coating solution for forming a photosensitive layer containing 30% by mass or more of water. material. The silver salt photothermographic dry imaging material according to any one of claims 1 to 6, 9, and 10, wherein the silver salt photothermographic dry imaging material is processed at a conveying speed of 30 mm / sec or more during heat development.