JP2001166418A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material which ensures a small sensitivity change independently of processing time and processing temperature and also ensures improved unevenness in development and improved linearity. SOLUTION: In the heat developable photosensitive material containing an organic silver salt, photosensitive silver halide, a reducing agent and a contrast enhancer on the substrate, the average particle diameter of the reducing agent, the contrast enhancer and a phthalazine compound is 0.15-0.80 μm and an image forming layer is formed by coating with a coating fluid in which >=60 mass% of the solvent is water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material, and more particularly to a photothermographic material suitable for printing plate making.

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical treatment, waste liquid due to wet processing of image forming materials has been a problem in terms of workability. Weight loss is strongly desired. Therefore, there is a need for a technique relating to photothermographic materials for photographic applications, which enables efficient exposure with a laser imagesetter or laser imager and can form a high-resolution and clear black image. This technique includes, for example, U.S. Patent Nos. 3,152,904 and 3,487,075 and D.C. "Dry Silver Photograph" by Morgan
phy Materials) "(Handbook
of Imaging Materials, Mar
cel Dekker, Inc. 48, 1991), a photothermographic material containing an organic silver, a photosensitive silver halide, a reducing agent and a binder on a support is known.

[0003] These photothermographic materials form a photographic image by a heat development process, and include a reducible silver source (organic silver salt), a photosensitive silver halide, a reducing agent and, if necessary, a silver salt. A color tone suppressing color tone is contained in the binder matrix in a dispersed state. The photothermographic material is stable at room temperature, but after exposure to high temperature (for example, 80 to 150).
(° C.). Heating generates silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is accelerated by the catalytic action of the latent image generated on the silver halide upon exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. This reaction process proceeds without supplying a processing liquid such as water from the outside.

It is essential that the photosensitive material for plate making has a high contrast. However, in the case of a photothermographic material using a high contrast agent, there is a disadvantage that the sensitivity varies greatly depending on the processing time and the processing temperature. . One of the causes is that the thermal development is biased toward the reaction control or the diffusion control. Therefore, the use of the photothermographic material has been limited to printed matter mainly composed of characters rather than images and small-sized printed matter. On the other hand, unique problems such as uneven development and linearity remain.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photothermographic material in which sensitivity fluctuations due to processing time and processing temperature are small and development unevenness and linearity are improved.

[0006]

The above object of the present invention is achieved by the following means.

[0007] 1. In a photothermographic material containing an organic silver salt, a photosensitive silver halide, a reducing agent and a high contrast agent on a support, a reducing agent having an average particle size of 0.15 to 0.80 μm,
A photothermographic material, characterized in that the image forming layer is coated using a coating liquid in which a high contrast agent and a phthalazine compound are dispersed in a particle form and water is 60% by mass or more of a solvent.

[0008] 2. In a photothermographic material containing an organic silver salt, a photosensitive silver halide, a reducing agent and a contrast agent on a support, a photothermographic material containing a reducing agent, a contrast agent and a phthalazine compound, and at least two or more of the compounds Is the total amount (m + p) of the addition amount (m) to the silver halide emulsion layer and the addition amount (p) to the layer other than the silver halide emulsion layer (m + p), p) ratio p / (m +
p) is from 0.1 to 1.0.

Hereinafter, the present invention will be described in detail. Conventionally, most photothermographic materials form an image forming layer by applying a coating solution using an organic solvent such as toluene, methyl ethyl ketone (MEK), or methanol as a solvent. Here, the image forming layer means a coating layer on the photosensitive layer side including the photosensitive silver halide emulsion layer and the protective layer, and is a term for the coating layer on the backing layer side.

In organic solvent-based coating, most of the additives are dissolved in an organic solvent and added. Therefore, a reducing agent, a high contrast agent, a phthalazine compound, and the like are present in the vicinity of silver halide grains at a molecular level. Therefore, the development of the photothermographic material of the organic solvent-based coating is reaction-limited and thus easily affected by the development temperature. When the development temperature fluctuates, the sensitivity greatly fluctuates. On the other hand, since the initial development is fast and the development progress is slow, the sensitivity fluctuation is small with respect to the processing time fluctuation.

As a result of various studies to solve this problem, the present inventor has found that a reducing agent, a high contrast agent and a part of the phthalazine compound, which greatly affect the heat developability, are added to a layer other than the silver halide emulsion layer. It has been found that the treatment temperature dependence is reduced by adding the compound to the reaction-controlling type and making it closer to the diffusion-controlling type.

More specifically, at least two or more of a reducing agent, a contrasting agent and a phthalazine compound are added to the silver halide emulsion layer (m) and added to layers other than the silver halide emulsion layer (p). The ratio p / (m + p) of the addition amount (p) to the layers other than the silver halide emulsion layer with respect to the total value (m + p) is preferably 0.1 to 1.0, and more preferably 0.3 to 1.0.
To 1.0, more preferably 0.5 to 1.0. Here, the amount of addition refers to the amount of addition per unit area of the photothermographic material.

The use of an organic solvent as a solvent is disadvantageous not only in adverse effects on the human body in the manufacturing process but also in cost due to the recovery of the solvent and the like. In order to apply the technology used for materials, a method of forming an image forming layer using a coating solution of an aqueous solvent has also been proposed. For example, JP-A-49-
JP-A Nos. 52626 and 53-116144 disclose examples using gelatin as a binder. JP-A-50-151138 discloses an example in which polyvinyl alcohol is used as a binder. Furthermore, Japanese Patent Laid-Open No. 60-
No. 61747 describes an example in which gelatin and polyvinyl alcohol are used in combination. As another example, JP-A-58-28737 describes an example of a photosensitive layer using water-soluble polyvinyl acetal as a binder.

The term "water-based" as used herein means that 60% by mass or more of the solvent (dispersion medium) of the coating solution is water. As components other than water of the coating solution, water-miscible organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Specific examples of the solvent composition include the following. Water / methanol = 90/10, water / methanol = 70/30, water / ethanol = 90/10, water / isopropanol = 9
0/10, water / dimethylformamide = 95/5, water /
Methanol / dimethylformamide = 80/15/5,
Water / methanol / dimethylformamide = 90/5/5
(However, the numbers represent mass%).

In the water-based coating, most of the additives are solidified with an average particle size of 1 to 2 μm and dispersed in a binder and added. Therefore, a reducing agent, a high contrast agent,
Particles such as phthalazine compounds are sparse. It takes time for these additives to reach the surface of the silver halide grains, making it difficult to start the initial development, and thereafter the development progress becomes very steep, which causes a sensitivity fluctuation. Since the development of the water-based photothermographic material is diffusion-controlled, it is easily affected by the development time, and the sensitivity varies greatly when the development time varies. On the other hand, even if the development temperature is slightly changed, the diffusion speed is not significantly affected by the diffusion control. The initial development is slow and the development progression is large, so that the sensitivity fluctuation due to the processing temperature fluctuation is small.

In order to solve this problem, the present inventors have studied the relationship between the particle size of the reducing agent, the high contrast agent, and the phthalazine compound, which greatly affect the heat developability, and the heat developability.
It has been found that the treatment time dependency is reduced by reducing the particle size of these additives and approaching the reaction rate control type from the diffusion control type.

More specifically, when the particle size of the reducing agent, the contrast agent, and the phthalazine compound is larger than 0.80 μm, it takes time to diffuse to the silver halide grains, and the temperature dependence is good, but the initial development is delayed. Requires development time. 0.
If it is less than 15 μm, the diffusion time will be short, but the reaction will be rate-determined and the temperature dependence will be large. Then, as a result of clarifying the relationship between the dispersion particle size and the development stability, it was found that 0.15 to 0.5.
It has been found that setting the particle size to 80 μm improves the processing stability. It is preferably from 0.15 to 0.80 μm, more preferably from 0.15 to 0.50 μm, and still more preferably from 0.15 to 0.50 μm. Dispersion of solid fine particles can be performed by a known micronizing means (for example, ball mill, vibrating ball mill,
Sand mill, colloid mill, jet mill, roller mill, etc.). In addition, a dispersion aid may be used when dispersing the solid fine particles.

On the other hand, problems such as uneven development and linearity due to minute variations in development temperature which are mechanically inevitable and unique to a photothermographic material using a high contrast agent have been improved by the above means.

The photosensitive silver halide used in the photothermographic material of the present invention can be prepared by any method known in the field of photographic technology such as a single jet or double jet method in the presence of a protective colloid such as gelatin. For example, it can be prepared by any method such as an ammonia method emulsion, a neutral method and an acid method. Thus, it can be prepared in advance and then mixed with other components of the present invention and introduced into the composition used in the present invention. In this case, in order to sufficiently contact the photosensitive silver halide with the organic silver salt, for example, US Pat.
No. 706,564, No. 3,706,565, No. 3,713,833, No. 3,748,143 and British Patent No. 1,362,970. A means for using a polymer other than gelatin, for example, a method for enzymatically decomposing gelatin in a light-sensitive silver halide emulsion as described in British Patent No. 1,354,186; 076,
As described in Japanese Patent No. 539, various means such as a method of omitting the use of a protective polymer by preparing photosensitive silver halide grains in the presence of a surfactant can be applied.

The average iodine content on the surface of the silver halide is preferably 0.1 to 10 mol%. More preferably, it is 1 to 7 mol%.

The silver halide grains function as an optical sensor. The shape of the silver halide is not particularly limited, and may be cubic, octahedral, so-called normal crystals or non-normal crystals, such as spherical, rod-shaped, and tabular grains. There is. The silver halide composition is not particularly limited, and the halide composition may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. In order to suppress white turbidity after image formation and obtain good image quality, the average particle size is preferably small, and the average particle size is preferably 0.1 μm or less, more preferably 0.01 to 0.1 μm, and particularly preferably 0.1 to 0.1 μm. 0
2 to 0.08 μm is preferred. The term "grain size" as used herein refers to the length of a ridge of a silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case of non-normal crystals, for example, in the case of spherical, rod-shaped or tabular grains, it refers to the diameter of a sphere equivalent to the volume of silver halide grains. Further, the silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion determined by the following formula is 40% or less.
It is more preferably at most 30%, particularly preferably 0.1%.
It is a particle which becomes 1 to 20%.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100 The amount of silver halide is 50% or less, preferably 0.1% or less, based on the total amount of silver halide and an organic silver salt described later. It is between 1 and 25%, more preferably between 0.1 and 15%.

The photosensitive silver halide used in the photothermographic material of the present invention can be used in preparing an organic silver salt as described in British Patent 1,447,454. By coexisting a halogen component such as the above with an organic silver salt forming component and injecting silver ions into the component, it is possible to generate the organic silver salt almost simultaneously.

As still another method, a silver halide forming component is allowed to act on a solution or dispersion of an organic silver salt prepared in advance or a sheet material containing the organic silver salt, so that a part of the organic silver salt is exposed to light. It can also be converted to neutral silver halide.
The silver halide thus formed is in effective contact with the organic silver salt and exhibits a preferable action. A silver halide-forming component is a compound capable of forming a photosensitive silver halide by reacting with an organic silver salt, and which compound is applicable and effective is determined by the following simple test. I can do things. That is, an organic silver salt is mixed with a compound to be tested, and if necessary, after heating, it is examined by an X-ray diffraction method whether there is a peak specific to silver halide. Silver halide-forming components confirmed to be effective by such tests include inorganic halogen compounds, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. Are U.S. Pat. Nos. 4,009,039 and 3,45
7,075, 4,003,749, British Patent 1,498,956 and JP-A-53-270.
Nos. 27 and 53-25420, each of which is described in detail below. (1) inorganic halide: For example, M is halide (here represented by MX _n, H, NH _4, and represents a metal atom, n represents 1 when the M is H and NH _4, M is a metal When it is an atom, it represents the same value as its valence.
Lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, zinc,
Cadmium, mercury, tin, antimony, chromium, manganese, iron, cobalt, nickel, rhodium, cerium, etc.). Further, halogen molecules such as bromine water are also effective. (2) Onium halides: quaternary ammonium halides such as trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, trimethylbenzylammonium bromide, quaternary phosphonium halides such as tetraethylphosphonium bromide, and trimethylsulfur There are tertiary sulfonium halides, such as phonium iodide. (3) Halogenated hydrocarbons: for example, iodoform,
Bromoform, carbon tetrachloride, 2-bromo-2-methylpropane and the like. (4) N-halogen compounds: For example, N-chlorosuccinimide, N-bromosuccinimide, N-bromophthalimide, N-bromoacetamide, N-iodosuccinimide, N-bromophthalazinone, N-bromo Oxazolinone, N-chlorophthalazinone, N-bromoacetanilide, N, N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, 1,3-dibromo-4,4-dimethylhydantoin, N- Bromourazole and the like. (5) Other halogen-containing compounds: for example, triphenylmethyl chloride, triphenylmethyl bromide, 2-bromoacetic acid, 2-bromoethanol, dichlorobenzophenone and the like.

These silver halide forming components are used in a small amount stoichiometrically with respect to the organic silver salt. Usually, the range is 0.001 to 0.7 mol, preferably 0.03 to 0.5 mol, per 1 mol of the organic silver salt. Two or more silver halide forming components may be used in combination within the above range. Various conditions such as reaction temperature, reaction time, reaction pressure and the like in the step of converting a part of the organic silver salt to silver halide using the above-mentioned silver halide forming component can be appropriately set according to the purpose of production. Usually, the reaction temperature is −20 to 70 ° C., the reaction time is 0.1 second to 72 hours, and the reaction pressure is preferably set to the atmospheric pressure. This reaction is also preferably performed in the presence of a polymer used as a binder described below. In this case, the amount of the polymer used was 1 organic silver salt.
0.01 to 100 parts, preferably 0.1 to 10 parts per part
Department.

The photosensitive silver halide prepared by the above-mentioned various methods includes, for example, sulfur-containing compounds, gold compounds,
Platinum compounds, palladium compounds, silver compounds, tin compounds,
Chemical sensitization can be achieved by a chromium compound or a combination thereof. The method and procedure of this chemical sensitization are described in, for example, U.S. Pat. No. 4,036,650, British Patent No. 1,518,850, JP-A-51-224.
No. 30, No. 51-78319, and No. 51-81124. Further, when a part of the organic silver salt is converted into a photosensitive silver halide by a silver halide forming component, as described in US Pat. No. 3,980,482, sensitization is achieved. A low molecular weight amide compound may coexist.

In addition, these photosensitive silver halides may be used in order to prevent illuminance failure and to adjust the gradation.
Metals belonging to group III, such as Rh, Ru, Re, Ir, O
An ion such as s or Fe, a complex thereof, or a complex ion can be contained. It is particularly preferable to add as a complex ion. For example, Ir complex ion such as IrCl ₆ ^2- may be added due to illuminance failure.

In the present invention, the organic silver salt is a reducible silver source, and is a silver salt of an organic acid or a heteroorganic acid, especially a long-chain (10 to 30 carbon atoms, preferably 15 to 25 carbon atoms).
Silver salts of aliphatic carboxylic acids and nitrogen-containing heterocyclic compounds are preferred. Organic or inorganic complexes in which the ligand has a value of 4.0 to 10.0 as the total stability constant for silver ions are also preferred. Examples of these suitable silver salts include the aforementioned R
D17029 and 29996, and include the following.

Silver salts of organic acids, such as gallic acid, oxalic acid,
Silver salts such as behenic acid, stearic acid, arachidic acid, palmitic acid and lauric acid. Silver carboxyalkylthiourea salts, for example, silver salts such as 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, and aldehydes with hydroxy-substituted aromatic carboxylic acids A silver salt or complex of a polymer reaction product, for example, a silver salt or complex of a reaction product of an aldehyde (formaldehyde, acetaldehyde, butyraldehyde, etc.) and a hydroxy-substituted acid (for example, salicylic acid, 3,5-dihydroxybenzoic acid); Silver salts or complexes of thiones, for example, 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione, and 3
Silver salts or complexes such as -carboxymethyl-4-thiazoline-2-thione, imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole;
Complexes or salts of silver and a nitrogen acid selected from 3-amino-5-benzylthio-1,2,4-triazole and benzotriazole, silver salts such as saccharin and 5-chlorosalicylaldoxime, and silver mercaptides. Among them, preferred silver salts include silver behenate, silver arachidate and silver stearate.

The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver.
A controlled double jet method as described in No. 3 is preferably used. For example, an organic acid alkali metal salt soap (eg, sodium hydroxide, potassium hydroxide, etc.)
After preparing sodium behenate, sodium arachidate, etc., the above-mentioned soap and silver nitrate are mixed by a controlled double jet method to produce an organic silver salt crystal. At that time, silver halide grains may be mixed.

In the present invention, the organic silver salt has an average particle size of 1
It is preferably 0 μm or less and monodispersed.
The average particle size of the organic silver salt refers to the diameter of a sphere equivalent to the volume of the organic silver salt particles when the particles of the organic silver salt are, for example, spherical, rod-shaped, or tabular particles. Average particle size is 0.05 to 10 μm, preferably 0.05 to 5 μm,
Particularly, the thickness is preferably 0.05 to 1.0 μm. The monodispersion has the same meaning as that of silver halide, and preferably has a monodispersity of 1 to 30.

In the present invention, the organic silver salt preferably has tabular grains containing at least 60% of the total organic silver.
In the present invention, the tabular grains mean those having an aspect ratio (abbreviated as AR) of 3 or more, which is a ratio between the average particle diameter and the thickness, that is, the following formula.

AR = average particle size (μm) / thickness (μm) In order to make the organic silver salt into these shapes, the crystal of the organic silver salt is dispersed and pulverized with a ball mill or the like with a binder or a surfactant. Obtained by: Within this range, a photosensitive material having a high density and excellent image storability can be obtained.

In the present invention, in order to prevent devitrification of the light-sensitive material, the total amount of silver halide and organic silver salt is preferably from 0.5 g to 2.2 g per m ² in terms of silver. . With this range, a high-contrast image can be obtained.

Examples of the reducing agent used in the photothermographic material of the present invention include generally known reducing agents, such as phenols, polyphenols having two or more phenol groups, naphthols and bisnaphthols. , 2
Polyhydroxybenzenes having at least two hydroxyl groups, 2
Polyhydroxynaphthalenes having at least two hydroxyl groups,
Ascorbic acids, 3-pyrazolidones, pyrazoline-
5-ones, pyrazolines, phenylenediamines, hydroxylamines, hydroquinone monoethers,
Hydroxamic acids, hydrazides, amide oximes, N-hydroxyureas, and the like. More specifically, for example, U.S. Patent Nos. 3,615,533 and 3,67.
9,426, 3,672,904, 3,7
No. 51,252, No. 3,782,949, No. 3,
Nos. 801,321, 3,794,488, 3,893,863, 3,887,376, 3,770,448, 3,819,382,
No. 3,773,512 and No. 3,839,048
No. 3,887,378, No. 4,009,03
9, No. 4,021,240, British Patent No. 1,48
No. 6,148 or Belgian Patent No. 786,086 and JP-A-50-36143, 50-36.
No. 110, No. 50-116023, No. 50-9971
No. 9, No. 50-140113, No. 51-51933
Nos. 51-23721, 52-84727 and JP-B-51-35851, and the present invention is appropriately selected from such known reducing agents. Can be used. As the selection method, the simplest method is to actually prepare a photothermographic material and evaluate the photographic performance of the photothermographic material to determine the superiority of the reducing agent used.

Among the above reducing agents, when a silver aliphatic carboxylate is used as the organic silver salt, preferred reducing agents include polyphenols in which two or more phenol groups are linked by an alkylene group or sulfur. In particular, an alkyl group (eg, methyl group, ethyl group, propyl group, t-butyl group, cyclohexyl group, etc.) or acyl group (eg, acetyl group, propionyl group, etc.) Are polyphenols in which two or more of the phenol groups substituted by an alkylene group or sulfur, for example, 1,1-bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5
5-trimethylhexane, 1,1-bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane,
1,1-bis (2-hydroxy-3,5-di-t-butylphenyl) methane, (2-hydroxy-3-t-butyl-5-methylphenyl)-(2-hydroxy-5-methylphenyl) Methane, 6,6'-benzylidene-bis (2,4-di-t-butylphenol), 6,6'-benzylidene-bis (2-t-butyl-4-methylphenol), 6,6'-benzylidene- Bis (2,4-dimethylphenol), 1,1-bis (2-hydroxy-
3,5-dimethylphenyl) -2-methylpropane,
1,1,5,5-tetrakis (2-hydroxy-3,5
-Dimethylphenyl) -2,4-ethylpentane, 2,
2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5
U.S. Pat. Nos. 3,589,903 and 4,021,249 or British Patent 1,486,148 and JP-A-51-51933. No. 50-36110, No. 50
Polyphenol compounds described in JP-A-116023, JP-A-52-84727 or JP-B-51-35727, bisnaphthols described in U.S. Pat. No. 3,672,904, for example, 2,2'- Dihydroxy-1,1'-binaphthyl, 6,6'-dibromo-
2,2'-dihydroxy-1,1'-binaphthyl, 6,
6'-dinitro-2,2'-dihydroxy-1,1'-
Binaphthyl, bis (2-hydroxy-1-naphthyl) methane, 4,4'-dimethoxy-1,1'-dihydroxy-2,2'-binaphthyl and the like, and further US Pat. No. 3,80
Sulfonamidophenols or sulfonamidonaphthols as described in US Pat. No. 1,321, for example, 4-benzenesulfonamidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4
-Benzenesulfonamidophenol, 4-benzenesulfonamidonaphthol and the like.

The amount of the reducing agent used in the photothermographic material of the present invention varies depending on the kind of the organic silver salt, the reducing agent, and other additives, but is preferably 1 × 10 ⁻ per mol of silver halide. ² to 10 mol, more preferably 1 × 10 ^-2 to
1.5 mol. Further, within this range, two or more of the above-mentioned reducing agents may be used in combination. In the present invention, it may be preferable to add and mix the reducing agent to the photosensitive solution immediately before coating and apply the reduced solution because the photographic performance fluctuation due to the stagnation time of the photosensitive solution is small.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. be able to.

When a mercapto compound is used in the present invention, it may be of any structure,
Those represented by -SS-Ar are preferred. Wherein M is a hydrogen atom or an alkali metal atom, and Ar is a heteroaromatic or fused heteroaromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Of these, preferred are benzimidazole, naphthymidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine , Pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring or fused heteroaromatic ring includes, for example, halogen (e.g., Br and Cl), hydroxy, amino, carboxy, alkyl (e.g., having one or more carbon atoms, preferably 1-4 carbon atoms). ) And alkoxy (e.g., those having one or more carbon atoms, preferably 1 to 4 carbon atoms). Examples of these compounds include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzothiazole, 3-mercapto-1,2,4-triazole, Mercaptoquinoline, 8-mercaptopurine, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-hydroxy-2-mercaptopyrimidine,
Examples include 2-mercapto-4-phenyloxazole, but the present invention is not limited thereto.

The photothermographic material of the present invention may contain an antifoggant. Mercury compounds known from, for example, U.S. Pat. No. 3,589,903 as effective antifoggants are environmentally undesirable. For this reason, non-mercury antifoggants have been studied for a long time. Non-mercury antifoggants include, for example, U.S. Pat. Nos. 4,546,075 and 4,452,885 and JP-A-59-5723.
No. 4 is preferred.

Particularly preferred non-mercury antifoggants are disclosed in US Pat. Nos. 3,874,946 and 4,756,99.
No.9, -C (X ₁ )
(X ₂ ) A heterocyclic compound having one or more substituents represented by (X ₃ ) (where X ₁ and X ₂ are halogen and X ₃ is hydrogen or halogen). Examples of suitable antifoggants include JP-A-9-288328, paragraph [0030].
To [0036] are preferably used.

As another example of the preferred antifoggant, JP-A-9-90550, paragraph [006]
2] to [0063]. Further, other suitable antifoggants are disclosed in US Pat.
No. 28,523 and European Patent Nos. 600,587, 605,981 and 631,176.

The photothermographic materials of the present invention include, for example, JP-A-63-159841, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, and JP-A-6-259561.
3-304242, 63-15245, U.S. Pat. Nos. 4,639,414 and 4,740,455,
Nos. 4,741,966 and 4,751,175
No. 4,835,096. Useful sensitizing dyes for use in the present invention include, for example, Research Disclosure Item
17643 IV-A (p. 23, December 1978), Item 18431X (p. 437, August 1979)
Or cited in the literature cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, JP-A-9-34078, JP-A-9-54409, and JP-A-9-80
No. 679 is preferably used.

Binders suitable for the photothermographic material of the present invention are transparent or translucent and generally colorless, and include natural polymers, synthetic polymers and copolymers, and other film-forming media such as gelatin, gum arabic and polyvinyl alcohol. , Hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethyl methacrylate, polymethacrylic acid, polyvinyl chloride, copoly (styrene-maleic anhydride),
Copoly (styrene-acrylonitrile), copoly (styrene-butadiene), polyvinylacetals such as polyvinylformal, polyvinylbutyral, polyesters, polyurethanes, phenoxy resins, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetates, cellulose Esters,
There are polyamides and the like, which may be water-soluble or water-insoluble. However, among these binders, particularly preferred are water-insoluble polymers such as cellulose acetate, cellulose acetate butyrate and polyvinyl butyral. Among these, particularly preferred polymers used in the photothermographic layer include polyvinyl formals Among them, polyvinyl butyral is particularly preferable, and polymers particularly preferable as the backcoat layer for the protective layer include cellulose acetate and cellulose acetate butyrate.

In the present invention, the binder amount of the photosensitive layer is preferably 1.5 to 6 g / m ² . More preferably, it is 1.7 to 5 g / m ² . If it is less than 1.5 g / m ² , the density of the unexposed portion will increase significantly and may not be usable.

In the present invention, a matting agent is preferably contained on the photosensitive layer side, and a matting agent is preferably disposed on the surface of the photosensitive material in order to prevent the image after thermal development from being damaged. Is preferably contained in a mass ratio of 0.5 to 30% based on all binders on the photosensitive layer side.

When a non-photosensitive layer is provided on the opposite side of the photosensitive layer with the support interposed therebetween, it is preferable that at least one layer on the non-photosensitive layer side contains a matting agent, so that the light-sensitive material has slipperiness and fingerprint adhesion. For prevention, it is preferable to provide a matting agent on the surface of the photosensitive material, and the matting agent is added in a mass ratio of 0.5 to 4 with respect to all binders of the layer on the side opposite to the photosensitive layer side.
It is preferable to contain 0%.

The material of the matting agent used in the present invention may be either an organic substance or an inorganic substance. For example, as inorganic substances, silica described in Swiss Patent No. 330,158, glass powder described in French Patent No. 1,296,995, etc., and alkali described in British Patent No. 1,173,181 etc. An earth metal or a carbonate such as cadmium or zinc can be used as a matting agent. Examples of organic substances include starch described in U.S. Pat. No. 2,322,037, Belgian Patent No. 625,451 and British Patent No. 981,198.
Derivatives, polyvinyl alcohol described in JP-B-44-3643 and the like, Swiss Patent No. 33
No. 0,158, polystyrene or polymethacrylate; U.S. Pat. No. 3,079,257; polyacrylonitrile; U.S. Pat. No. 3,022,16.
An organic matting agent such as polycarbonate described in No. 9 or the like can be used.

The shape of the matting agent may be either regular or irregular, but is preferably regular and spherical. The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a sphere. In the present invention, the particle diameter of the matting agent indicates the diameter converted into a sphere.

The matting agent used in the present invention preferably has an average particle size of 0.5 to 10 μm, more preferably 1.0 to 8.0 μm. Further, the coefficient of variation of the particle size distribution is preferably 50% or less.
It is preferably at most 40%, particularly preferably at most 30%.

Here, the coefficient of variation of the particle size distribution is a value represented by the following equation. (Standard deviation of particle size) / (Average value of particle size) × 100 These matting agents can be contained in any constituent layer. However, in order to achieve the object of the present invention, it is preferable to use a layer other than the photosensitive layer. It is a constituent layer, more preferably the outermost layer as viewed from the support.

The method of adding the matting agent according to the present invention may be a method of dispersing in a coating solution in advance and applying the solution.
A method of spraying a matting agent after the application liquid is applied and before the drying is completed may be used. When a plurality of types of matting agents are added, both methods may be used in combination.

The photothermographic material of the present invention contains a high contrast agent. The addition amount is 1 × 10 ^-3 per mol of silver halide.
１1 mol, more preferably 1 × 10 ^{−3 to} 0.5 mol. Examples of the high contrast agent include a hydrazine derivative, a compound represented by the following general formula (G), and a quaternary onium compound represented by the following general formula (P).

[0054]

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In the general formula (G), X and R are represented in a cis form, but the general formula (G) also includes a trans form of X and R. This is the same in the structural representation of a specific compound.

Examples of the hydrazine derivative include a compound represented by the following general formula [H].

[0057]

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In the formula, A ₀ represents an aliphatic group, an aromatic group, a heterocyclic group or a -G ₀ -D ₀ group which may have a substituent.
B ₀ represents a blocking group, and A ₁ and A ₂ each 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 ) represents a group, G ₁ represents a mere bond, an —O— group, —S—
Group or -N (D ₁₎ - represents a group, D ₁ is an aliphatic group, an aromatic group, a heterocyclic group or a hydrogen atom, a plurality of D ₁ in the molecule
If they are present, they can be the same or different. D ₀ is a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group,
Represents 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 preferably has 1 to 30 carbon atoms, and particularly preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. For example, methyl group, ethyl group, t-butyl group, octyl group, cyclohexyl group, benzyl group,
These may be further substituted with a suitable substituent (for example, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, sulfoxy group, sulfonamide 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 ring aryl group, for example, a benzene ring or a naphthalene ring, and a heterocyclic ring represented by A _0. As the group, a heterocyclic ring containing at least one heteroatom selected from nitrogen, sulfur, and oxygen atom in a single ring or a condensed ring is preferable, for example, a pyrrolidine ring, an imidazole ring, a tetrahydrofuran ring, a morpholine ring, a pyridine ring, a pyrimidine ring, Examples include a quinoline ring, 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 diffusion-resistant group or a silver halide-adsorbing group. As the diffusion-resistant group, a ballast group commonly used in immobile photographic additives such as couplers is preferable, and as the ballast group, a photographically inactive alkyl group, alkenyl group, alkynyl group, alkoxy group, phenyl Group,
Examples thereof include a phenoxy group and an alkylphenoxy group, and the total number of carbon atoms in the substituent 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 special groups. 64-9
No. 0439.

In the general formula [H], B ₀ represents a blocking group, preferably -G ₀ -D ₀ group, and G ₀ represents-
CO- group, -COCO- group, -CS- group, -C (= NG
₁ D ₁₎ - group, -SO- group, -SO ₂ - group or -P (O)
(G ₁ D ₁ ) — represents a group. Preferred G ₀ is -CO-
Group, -COCO- group, G ₁ is a mere bond,
—O—, —S— or —N (D ₁ ) —, wherein D ₁ represents an aliphatic group, an aromatic group, a heterocyclic group or a hydrogen atom, and a plurality of D ₁ are present in the molecule If so, 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, And an amino group. 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.), a sulfonyl group (methanesulfonyl group, toluenesulfonyl group, etc.), or an oxalyl group (Such as an ethoxalyl group).

Next, specific examples of the compound represented by the general formula [H] are shown below, but it should not be construed that the invention is limited thereto.

[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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More preferred hydrazine derivatives are represented by the following formulas (H-1), (H-2), (H-3) and (H-4)
It is represented by

[0073]

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In the general formula (H-1), R ₁₁ , R ₁₂ and R ₁₃ each independently represent a substituted or unsubstituted aryl group or heteroaryl group. Specific examples of the aryl group include phenyl, p-Methylphenyl, naphthyl and the like. Specific examples of the heteroaryl group include, for example, a triazole residue, an imidazole residue,
Examples include a pyridine residue, a furan residue, and a thiophene residue. Further, R ₁₁ , R ₁₂ and R ₁₃ may be bonded via an arbitrary linking group. When R ₁₁ , R ₁₂ and R ₁₃ have a substituent, examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, and a quaternary heterocyclic group containing a nitrogen atom ( For example, a pyridinio group), a hydroxy group, an alkoxy group (including a group containing a repeating ethyleneoxy or propyleneoxy group unit), an aryloxy group, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, and a urethane Group, carboxyl group, imide group, amino group, carbonamide group, sulfonamide group, ureido group, thioureido group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, quaternary ammonium group, (alkyl,
Aryl or heterocycle) thio group, mercapto group,
(Alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group, sulfamoyl group, acylsulfamoyl group, (alkyl or aryl) sulfonyluureido group, (alkyl or aryl) sulfonylcarbamoyl group, halogen atom, cyano Group, nitro group, phosphoric acid amide group and the like. Each of R ₁₁ , R ₁₂ and R ₁₃ is preferably a substituted or unsubstituted phenyl group, and more preferably, each of R ₁₁ , R ₁₂ and R ₁₃ is an unsubstituted phenyl group.

R ₁₄ represents a heteroaryloxy group or a heteroarylthio group. Specific examples of the heteroaryloxy group include a pyridyloxy group, a pyrimidyloxy group,
Examples include an indolyloxy group, a benzothiazolyloxy group, a benzimidazolyloxy group, a furyloxy group, a thienyloxy group, a pyrazolyloxy group, and an imidazolyloxy group. Specific examples of the heteroarylthio group include a pyridylthio group, a pyrimidylthio group, an indolylthio group, a benzothiazolylthio group, a benzimidazolylthio group, a furylthio group, a thienylthio group, a pyrazolylthio group, and an imidazolylthio group. R ₁₄ is preferably a pyridyloxy group or a thienyloxy group.

A ₁ and A ₂ are both hydrogen atoms, or one is a hydrogen atom and the other is an acyl group (acetyl, trifluoroacetyl, benzoyl, etc.), a sulfonyl group (methanesulfonyl, toluenesulfonyl, etc.), or an oxalyl group ( Ethoxalyl). Preferably, A ₁ and A ₂ are both hydrogen atoms.

In the general formula (H-2), R ₂₁ represents a substituted or unsubstituted alkyl group, aryl group or heteroaryl group. Specific examples of the alkyl group include a methyl group, an ethyl group and a t-butyl group. Group, 2-octyl group, cyclohexyl group, benzyl group, diphenylmethyl group and the like. Specific examples of the aryl group and the heteroaryl group include the same groups as R ₁₁ , R ₁₂ and R ₁₃ . When R ₂₁ has a substituent, specific examples of the substituent include those similar to the substituents of R ₁₁ , R ₁₂ and R ₁₃ . R ₂₁ is preferably an aryl group or a heteroaryl group, and particularly preferably a substituted or unsubstituted phenyl group.

R ₂₂ represents hydrogen, an alkylamino group, an arylamino group, or a heteroarylamino group. Specific examples of the alkylamino group include a methylamino group, an ethylamino group, a propylamino group, a butylamino group, and a dimethylamino group. Examples include an amino group, a diethylamino group, and an ethylmethylamino group. As the arylamino group, an anilino group,
Examples of the heteroaryl group include a thiazolylamino group, a benzimidazolylamino group, and a benzthiazolylamino group. Preferably the R ₂₂ is dimethylamino group or diethylamino group.

A ₁ and A ₂ are those represented by the general formula (H-1)
₁ is the same as A _2. In the general formula (H-3),
R ₃₁ and R ₃₂ each represent a monovalent substituent, and examples of the monovalent substituent include those described as substituents of R ₁₁ , R ₁₂ and R ₁₃ .
And an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, and an amino group. More preferably, it is an aryl group or an alkoxy group. Particularly preferred are those in which at least one of R ₃₁ and R ₃₂ is a tert-butoxy group, and another preferred structure is that when R ₃₁ is a phenyl group, R ₃₂ is tert-butoxy.
-A butoxy group.

G ₃₁ and G ₃₂ represent a — (CO) p- group, and —C (=
S)-, a sulfonyl group, a sulfoxy group, -P (= O) R
Represents a ₃₃ -group or an iminomethylene group, p represents an integer of 1 or 2, R ₃₃ represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an alkenyloxy group, an alkynyloxy group, an aryloxy group, Represents an amino group. However, when G ₃₁ is a sulfonyl group, G ₃₂ is not a carbonyl group. G ₃₁ and G ₃₂ are preferably -CO
—, —COCO—, sulfonyl or —CS—, more preferably —CO— or mutually sulfonyl.

A ₁ and A ₂ are those represented by the general formula (H-1)
₁ is the same as A _2. In the general formula (H-4),
R ₄₁ , R ₄₂ and R ₄₃ have the same meanings as R ₁₁ , R ₁₂ and R ₁₃ in formula (H-1). Each of R ₄₁ , R ₄₂ and R ₄₃ is preferably a substituted or unsubstituted phenyl group, more preferably R ₄₁ , R ₄₂ and R ₄₃
Is an unsubstituted phenyl group. R ₄₄ and R ₄₅ represent an unsubstituted or substituted alkyl group, and specific examples include a methyl group, an ethyl group, a t-butyl group, a 2-octyl group, a cyclohexyl group, a benzyl group, and a diphenylmethyl group. No. R ₄₄ and R ₄₅ are preferably each an ethyl group.

A ₁ and A ₂ are those represented by the general formula (H-1)
₁ is the same as A _2. The general formula (H-1) of the present invention is described below.
Specific examples of the compounds represented by formulas (1) to (H-4) will be given below, but the present invention is not limited thereto.

[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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The compounds represented by the general formulas (H-1) to (H-
The compound represented by 4) can be easily synthesized by a known method. For example, US Pat. No. 5,464,73
No. 8 or U.S. Pat. No. 5,496,695.

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

In the general formula (G), X represents an electron-withdrawing group, and W is a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a halogen atom,
Acyl group, thioacyl group, oxalyl group, oxyoxalyl group, thiooxalyl group, oxamoyl group, oxycarbonyl group, thiocarbonyl group, carbamoyl group, thiocarbamoyl group, sulfonyl group, sulfinyl group, oxysulfonyl group, thiosulfonyl group, sulfamoyl Group, oxysulfinyl group, thiosulfinyl group, sulfinamoyl group, phosphoryl group, nitro group, imino group,
An N-carbonylimino group, an N-sulfonylimino group, a dicyanoethylene group, an ammonium group, a sulfonium group,
Represents a phosphonium group, a pyrylium group, or an immonium group.

R represents a halogen atom, a hydroxy group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkenyloxy group, an acyloxy group, an alkoxycarbonyloxy group, an aminocarbonyloxy group, a mercapto group,
Organic or inorganic salts of an alkylthio group, an arylthio group, a heterocyclic thio group, an alkenylthio group, an acylthio group, an alkoxycarbonylthio group, an aminocarbonylthio group, a hydroxy group or a mercapto group (for example, sodium salt, potassium salt, silver salt) Etc.), an amino group, an alkylamino group, a cyclic amino group (for example, a pyrrolidino group), an acylamino group, an oxycarbonylamino group, a heterocyclic group (5-
A 6-membered nitrogen-containing heterocycle, for example, a benztriazolyl group,
Imidazolyl group, triazolyl group, tetrazolyl group, etc.), ureido group, and sulfonamide 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 is a substituent whose substituent constant σp can take a positive value. Specifically, a substituted alkyl group (eg, halogen-substituted alkyl), a substituted alkenyl group (eg, cyanovinyl), a substituted / unsubstituted alkynyl group (eg, trifluoromethylacetylenyl, cyanoacetylenyl),
Substituted aryl group (cyanophenyl, etc.), substituted / unsubstituted heterocyclic group (pyridyl, triazinyl, benzoxazolyl, etc.), halogen atom, cyano group, acyl group (acetyl, trifluoroacetyl, formyl, etc.), thioacetyl group (Thioacetyl, thioformyl, etc.), oxalyl group (methyloxalyl, etc.), oxyoxalyl group (ethoxalyl, etc.), thiooxalyl group (ethylthiooxalyl, etc.), oxamoyl group (methyloxamoyl, etc.), oxycarbonyl group (ethoxycarbonyl, etc.) , Carboxyl group, thiocarbonyl group (such as ethylthiocarbonyl),
Carbamoyl group, thiocarbamoyl group, sulfonyl group,
Sulfinyl group, oxysulfonyl group (ethoxysulfonyl, etc.), thiosulfonyl group (ethylthiosulfonyl, etc.), sulfamoyl group, oxysulfinyl group (methoxysulfinyl, etc.), thiosulfinyl group (methylthiosulfinyl, etc.), sulfinamoyl group, sphinamoyl 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 And an immonium group, and a heterocyclic group in which an ammonium group, a sulfonium group, a phosphonium group, an immonium group, and the like form a ring is also included. A substituent having a σp value of 0.30 or more is particularly preferred.

The alkyl group represented by W is methyl, ethyl, trifluoromethyl and the like, the alkenyl group is vinyl, halogen-substituted vinyl and cyanovinyl, and the alkynyl group is acetylenyl and cyanoacetylenyl. Examples of the group include nitrophenyl, cyanophenyl, and pentafluorophenyl, and examples of the heterocyclic group include pyridyl, pyrimidyl, triazinyl, succinimide, tetrazolyl, triazolyl, imidazolyl, and benzoxazolyl. W is σ
A p-value is preferably a positive electron-withdrawing group, and more preferably, the value is 0.30 or more.

Of the above substituents for R, preferably a hydroxy group, a mercapto group, an alkoxy group, an alkylthio group,
Halogen atom, an organic or inorganic salt of a hydroxy group or a mercapto group, and a heterocyclic group, more preferably a hydroxy group, an alkoxy group, an organic or inorganic salt of a hydroxy group or a mercapto group, a heterocyclic group, Particularly preferred is an organic or inorganic salt of a hydroxy group, a hydroxy group or a mercapto group.

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

Next, specific examples of the compound represented by formula (G) are shown below, but it should not be construed that the invention is limited thereto.

[0099]

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[0100]

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[0101]

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[0102]

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[0103]

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[0104]

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[0105]

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[0106]

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[0107]

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[0108]

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[0109]

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[0110]

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[0111]

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[0112]

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[0113]

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[0114]

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[0115]

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[0116]

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[0117]

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[0118]

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[0119]

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[0120]

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[0121]

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[0122]

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In the general formula (P), Q 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. Note that R _{1 to} R
₄ may be connected to each other to form a ring.

As the substituent represented by R _{1 to} R ₄ , an alkyl group (methyl group, ethyl group, propyl group, butyl group,
Hexyl group, cyclohexyl group, etc., alkenyl group (allyl group, butenyl group, etc.), alkynyl group (propargyl group, butynyl group, etc.), aryl group (phenyl group, naphthyl group, etc.), heterocyclic group (piperidinyl group, piperazinyl group) , Morpholinyl group, pyridyl group, furyl group, thienyl group, tetrahydrofuryl group, tetrahydrothienyl group,
Sulfolanyl group), an amino group and the like.

The ring which may be formed by linking R _{1 to} R ₄ includes a piperidine ring, a morpholine ring, a piperazine ring,
Examples include a quinuclidine ring, a pyridine ring, a pyrrole ring, an imidazole ring, a triazole ring, and a tetrazole ring.

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

As R ₁ , R ₂ , R ₃ and R ₄ , a hydrogen atom and an alkyl group are preferred. Examples of the anion represented by X ⁻ include inorganic and organic anions such as a halogen ion, a sulfate ion, a nitrate ion, an acetate ion and a p-toluenesulfonic acid ion.

More preferably, the following general formulas (Pa) and (P
b) or a compound represented by (Pc); and a compound represented by the following general formula [T].

[0129]

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In the formula, A ¹ , A ² , A ³ , A ⁴ and A ⁵ represent a group of nonmetal atoms for completing a nitrogen-containing heterocyclic ring, and may contain an oxygen atom, a nitrogen atom and a sulfur atom. And the benzene ring may be condensed. A ¹ , A ² , A ³ , A ⁴ and A ⁵
May have a substituent and may be the same or different. Examples of the substituent include an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, a halogen atom, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfo group, a carboxy group, a hydroxy group, an alkoxy group, and an aryloxy group. , Amide group, sulfamoyl group, carbamoyl group,
Represents a ureido group, amino group, sulfonamide group, sulfonyl group, cyano group, nitro group, mercapto group, alkylthio group and arylthio group. A ¹ , A ² , A ³ , A ⁴ and A
Preferred examples of ⁵ include a 5- to 6-membered ring (each ring of pyridine, imidazole, thiozole, oxazole, pyrazine, pyrimidine and the like), and more preferred examples include a pyridine ring.

_BP represents a divalent linking group, and m represents 0 or 1
Represents Examples of the divalent linking group include an alkylene group, an arylene group, an alkenylene group, —SO ₂ —, —SO—, and —O
—, —S—, —CO—, and —N (R ⁶ ) — (R ⁶ represents an alkyl group, an aryl group, or a hydrogen atom) alone or in combination. Preferred examples of B _p include an alkylene group and an alkenylene group.

R¹, R^TwoAnd R^FiveEach have 1 to 20 carbon atoms
Represents an alkyl group. Also, R¹And R ^TwoAre the same but different
May be. An alkyl group is a substituted or unsubstituted alkyl group.
Represents a kill group, and the substituent is A¹, A^Two, A^Three, A^FourPassing
And A^FiveAre the same as the substituents exemplified as the substituent for.

Preferred examples of R ¹ , R ² and R ⁵ include:
Each is an alkyl group having 4 to 10 carbon atoms. More preferred examples include a substituted or unsubstituted aryl-substituted alkyl group.

[0134] X _p ^- is a counter ion necessary to balance the charge of the whole molecule, for example chloride, bromide,
It represents iodine ion, nitrate ion, sulfate ion, p-toluenesulfonate, oxalate and the like. n _p represents the number of counter ions required to balance the charge of the whole molecule, and n _p is 0 in the case of an internal salt.

[0135]

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The substituents R ₅ and R ₆ of the phenyl group of the triphenyltetrazolium compound represented by the general formula [T],
R ₇ is preferably a hydrogen atom or a compound having a negative Hammett sigma value (σP) indicating electron-withdrawing degree.

The Hammett's sigma value for the phenyl group is described in many literatures, for example, Journal of Medical Chemistry.
chemistry, 20, 304, 1977. The group having a particularly preferable negative sigma value is, for example, a methyl group (σP = −0.17 or less, all σP values) and an ethyl group (− 0.15), cyclopropyl group (-0.21), n-propyl group (-0.13), is
o-propyl group (-0.15), cyclobutyl group (-
0.15), n-butyl group (-0.16), iso-butyl group (-0.20), n-pentyl group (-0.1
5), cyclohexyl group (-0.22), amino group (-
0.66), acetylamino group (-0.15), hydroxy group (-0.37), methoxy group (-0.27), ethoxy group (-0.24), propoxy group (-0.2
5), butoxy group (-0.32), pentoxy group (-
0.34), etc., each of which has the general formula [T]
Is useful as a substituent of the compound of

N represents 1 or 2, and examples of the anion represented by X _T ^n- include halogen ions such as chloride ion, bromide ion and iodide ion, nitric acid, sulfuric acid, and the like.
Acid radicals of inorganic acids such as perchloric acid, acid radicals of organic acids such as sulfonic acid and carboxylic acid, anionic activators, specifically p-
Lower alkylbenzene sulfonic acid anions such as toluene sulfonic acid anion; higher alkyl benzene sulfonic acid anions such as p-dodecyl benzene sulfonic acid anion; higher alkyl sulfate anions such as lauryl sulfate anion; boric acid anions such as tetraphenyl boron; Dialkyl sulfosuccinate anions such as 2-ethylhexyl sulfosuccinate anion,
Examples thereof include higher fatty acid anions such as cetyl polyethenoxy sulfate anion, and polymers having an acid radical attached to a polymer such as polyacrylate anion.

Specific examples of the quaternary onium compound are shown below, but the invention is not limited thereto.

[0140]

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[0141]

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[0142]

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[0143]

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[0144]

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[0145]

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[0146]

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[0147]

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[0148]

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[0149]

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The above quaternary onium compound can be easily synthesized according to a known method. For example, the above tetrazolium compound can be obtained from Chemical Reviews vol. 55
p. 335-483 can be referred to.

The photothermographic material of the present invention, which forms a photographic image by heat development, comprises a reducible silver source (organic silver salt), a photosensitive silver halide, a reducing agent and, if necessary, silver. It is preferable that the photothermographic material contains a color tone suppressing color tone in a binder matrix in a dispersed state.

Examples of preferred color toning agents in the present invention are:
rc Disclosure No. 17029, which includes:

Imides (for example, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (for example, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2 , 4-thiazolidinedione); naphthalimides (e.g., N-hydroxy-1,8-naphthalimide); cobalt complexes (e.g., hexaamminetrifluoroacetate of cobalt); mercaptans (e.g., 3-mercapto-1,2,2,3). 4-triazole); N
-(Aminomethyl) aryldicarboximides (eg, N- (dimethylaminomethyl) phthalimide);
Blocked pyrazoles (e.g., N, N'-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole)); isothiuronium
onium) derivatives and certain photobleaches (eg, 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2
-(Tribromomethylsulfonyl) benzothiazole combination); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-
Dimethyloxyphthalazinone and 2,3-dihydro-
1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone and sodium benzenesulfinate or 8-methylphthalazinone and sodium p-trisulfonate); a mixture of phthalazine and phthalic acid Combinations; phthalazine (including phthalazine adducts) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivative and its anhydrides (e.g., phthalic acid, 4-methylphthalic acid, -Nitrophthalic acid and tetrachlorophthalic anhydride); quinazolinediones, benzoxazine, naphthoxazine derivatives; benzoxazine-2,4
-Diones (for example, 1,3-benzoxazine-2,
4-dione); pyrimidines and asymmetric triazines (eg, 2,4-dihydroxypyrimidine), and tetraazapentalene derivatives (eg, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2, 3a, 5, 6
a-tetraazapentalene). Preferred toning agents are phthalazinone or a combination of phthalazine and phthalic acid.

In the present invention, a phthalazine compound is particularly preferable, and specific examples thereof are shown below.

[0155]

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The amount of addition is 1 × 10 ⁻⁴ to 1 mol, preferably 1 × 10 ^{−3 to} 0.3 mol, more preferably 1 × 10 ^{−3 to} 0.1 mol, per mol of silver halide. is there.

In addition to these materials, various additives may be added to the photosensitive layer, the non-photosensitive layer, or other forming layers according to the purpose. The photothermographic material of the invention may contain, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid, and the like. These additives and the other additives mentioned above are ResearchDi.
slosure 17029 (p.9 June 1978)
To 15) can be preferably used.

As the material of the support used for the photothermographic material, various polymer materials, glass, wool cloth, cotton cloth,
Paper, metal (for example, aluminum) and the like can be mentioned, but in terms of handling as an information recording material, a material that can be processed into a flexible sheet or roll is preferable. Accordingly, the support in the photothermographic material of the present invention is preferably a plastic film (eg, a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyamide film, a polyimide film, a cellulose triacetate film, a polycarbonate film, etc.). In the present invention, a biaxially stretched polyethylene terephthalate film is particularly preferred. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.
m.

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

There is no particular limitation on the method of coating the necessary layers such as a photosensitive layer, a protective layer and a back coat layer on the photosensitive material of the present invention.
Methods such as dip coating, bar coating, curtain coating, and hopper coating can be used. Further, two or more of these layers may be applied simultaneously.

The heat-developable photographic light-sensitive material of the present invention is formed by preparing a coating solution obtained by dissolving or dispersing the above-described constituent layer materials in a solvent, applying a plurality of these coating solutions simultaneously and then performing a heat treatment. Is preferably performed. Here, “multi-layer coating at the same time” means that a coating solution for each constituent layer (for example, a photosensitive layer and a protective layer) is prepared, and when the coating solution is applied to a support, coating and drying are repeated for each layer individually. In other words, it means that each constituent layer can be formed in a state where the steps of simultaneously performing the multilayer coating and drying can be performed at the same time. That is, the upper layer is provided before the remaining amount of the entire solvent in the lower layer becomes 70% by mass or less.

There is no particular limitation on the method of simultaneously applying a plurality of the constituent layers in a multi-layered manner. For example, known methods such as a bar coater method, a curtain coat method, a dipping method, an air knife method, a hopper coating method, and an extrusion coating method. Can be used. Of these, a pre-metering type coating method called an extrusion coating method is more preferable. The extrusion coating method is suitable for precision coating and organic solvent coating since there is no volatilization on the slide surface unlike the slide coating method.

In the present invention, after the simultaneous multi-layer coating is performed, the coated layer surface is dried by successively performing a heat treatment, so that the adhesiveness between the support and the photosensitive layer and between the photosensitive layer and the protective layer is reduced. And delamination is prevented from occurring.
This coating method has been described on the side having the photosensitive layer, but the same applies to the case where the backcoat layer is provided and the coating is performed together with the undercoating.

The image forming method of the present invention is characterized in that the photothermographic material obtained as described above is exposed and then developed by a heat treatment at 80 to 200 ° C.

In the present invention, the development conditions vary depending on the equipment, apparatus, or means used, but typically, the heat-developable photographic material exposed imagewise at a suitable high temperature is heated. Accompanies you. The latent image obtained after the exposure is exposed to a heat 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 material can be developed by heating. The equipment, apparatus or means for heating may be performed by a typical heating means such as a heat generator using a hot plate, an iron, a hot roller, carbon or white titanium or the like. More preferably, it is transported while being in contact with the heat roller, heated, and developed, from the viewpoint of thermal efficiency and workability.

The photothermographic 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 to protect the photothermographic layer, and a back coat layer is provided on the opposite surface of the support to prevent sticking between photosensitive materials or in a photosensitive material roll. Is preferably provided. Further, a filter layer may be formed on the same side as or opposite to the photosensitive layer to control the amount or wavelength distribution of light transmitted through the photothermographic layer, or the photosensitive layer may contain a dye or pigment. Good. As the dye, compounds described in JP-A-8-201959 are preferred. The photosensitive layer may be composed of a plurality of layers, or a high-sensitivity layer and a low-sensitivity layer may be provided for adjusting the gradation, and these layers may be combined. Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other forming layers.

The photothermographic material of the present invention is stable at room temperature, but is developed by heating to high temperature after exposure. The heating temperature is preferably from 80 to 200 ° C, and more preferably from 100 to 150 ° C. If the heating temperature is lower than 80 ° C., a sufficient image density cannot be obtained in a short time, and if the heating temperature is higher than 200 ° C., the binder is melted and adversely affects not only the image itself but also transportability such as transfer to a roller and a developing machine. Effect. By heating, a silver image is generated by an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This reaction process proceeds without any supply of a processing liquid such as water from the outside.

Exposure of the photothermographic material of the present invention can be applied to any light source in the infrared light range. However, in view of the fact that the laser power is high and the photosensitive material can be made transparent. , Infrared semiconductor laser (780 nm, 8
20 nm) is more preferably used.

In the present invention, the exposure is preferably performed by laser scanning exposure, but it is preferable to use a laser scanning exposure machine in which the angle between the exposure surface of the photosensitive material and the scanning laser beam does not become substantially perpendicular. .

Here, "not substantially perpendicular" means that the angle is most perpendicular during laser scanning, preferably 55 to 88 degrees, more preferably 60 to 86 degrees.
More preferably 65-84 degrees, most preferably 70-8 degrees.
It means twice.

When a laser beam is scanned on the photosensitive material, the beam spot diameter on the exposed surface of the photosensitive material is preferably 200 μm or less, more preferably 100 μm or less. It is preferable that the spot diameter is small in that the shift angle of the laser incident angle from the perpendicular can be reduced. Note that 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 occurrence of unevenness like interference fringes.

It is also preferable that the exposure in the present invention is performed using a laser scanning exposure machine which emits a scanning laser beam which is a vertical multi. Image quality deterioration such as generation of interference fringe-like unevenness is reduced as compared with the scanning laser beam in the longitudinal single mode.

[0173] In order to form the vertical multiple, a method such as combining, using return light, or superimposing a high frequency is preferable.
In addition, 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.
nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

[0174]

EXAMPLES Example 1 (Preparation of PET support) PET pellets were
After drying for an hour, it was melted at 300 ° C., extruded from a T-die, and quenched to prepare an unstretched film. This was longitudinally stretched 3.0 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After this, 240 ° C
After heat setting for 20 seconds, the film was relaxed 4% in the horizontal direction at the same temperature. Thereafter, the chuck portion of the tenter was slitter, and both ends were knurled and wound at 4 kg / cm ² . Thus, a roll of a PET film having a width of 2.4 m, a length of 800 m, and a thickness of 125 μm was obtained. This PE
The glass transition point of the T film was 79 ° C.

The biaxially stretched and heat-fixed PET film support having a thickness of 125 μm and having a thickness of 125 μm was subjected to a corona discharge treatment of 8 W / m ² · min. The undercoating coating solution a-1 shown below was applied so as to have a dry film thickness of 0.8 μm and dried to form an undercoating layer A-1.
On the other side, an undercoating coating solution b-1 subjected to the following antistatic treatment was applied so as to have a dry film thickness of 0.8 μm and dried to obtain an antistatic undercoat layer B-1.

<< Undercoat Coating Solution a-1 >> Butyl acrylate (30% by mass) t-butyl acrylate (20% by mass) Styrene (25% by mass) 2-hydroxyethyl acrylate (25% by mass) copolymer latex liquid (Solid content 30%) 270 g (C-1) 0.6 g hexamethylene-1,6-bis (ethylene urea) 0.8 g polystyrene fine particles (average particle diameter 3 μm) 0.05 g colloidal silica (average particle diameter 90 μm) 0 0.1 g Finished to 1 L with water << Undercoat coating solution b-1 >> SnO ₂ / Sb (9/1 mass ratio, average particle size 0.18 μm) Amount to become 200 mg / m ² Butyl acrylate (30% by mass) Styrene ( 20% by mass) Glycidyl acrylate (40% by mass) copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 g hexa Styrene-1,6-bis (ethyleneurea) subsequently finished into 1L with 0.8g water, the undercoat layer A-1 and the upper surface undercoat layer B-1,
A corona discharge of 8 W / m ² · min. Was performed, and the following lower coating liquid a-2 was coated on the lower coating layer A-1 with a dry film thickness of 0.1 μm.
The lower coating layer B-2 is coated with the following coating liquid b-2 on the lower coating layer B-1 so as to have a dry film thickness of 0.8 μm. Coated as B-2.

<< Coating Solution a-2 for Subbing Upper Layer >> Gelatin 0.4 g / m ² (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles ( (Average particle size: 3 μm) 0.1 g Finished to 1 L with water << Lower upper coating liquid b-2 >> (C-4) 60 g Latex liquid containing (C-5) as a component (solid content: 20%) 80 g Ammonium sulfate 5 g (C-6) 12 g Polyethylene glycol (weight average molecular weight 600) 6 g Finish to 1 L with water.

[0178]

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[0179]

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<< Heat Treatment of Support >> In the above-mentioned undercoat drying step of the undercoated support, the support was heated at 140 ° C. and then gradually cooled.

(Preparation of Silver Halide Emulsion A) 900 m of water
7.5 g of inert gelatin and 10 ml of potassium bromide
mg, and adjusted to a temperature of 35 ° C. and a pH of 3.0, and 370 ml of an aqueous solution containing 74 g of silver nitrate (60/3
The molar ratio of potassium iodide sodium chloride and potassium bromide and [Ir (NO) Cl _5] salt per mole silver 1 × 10 ^-6 mol and 1 mol of silver per 1 × rhodium chloride salt 8/2) 370 ml of an aqueous solution containing 10 ^-6 mol was added to pAg7.
While maintaining at 7, the addition was performed by the controlled double jet method. Thereafter, 4-hydroxy-6-methyl-1,3,3
a, 7-tetrazaindene was added, the pH was adjusted to 8 with NaOH, and the pAg was adjusted to 6.5 to perform reduction sensitization. The average grain size was 0.06 μm, and the coefficient of variation of the projected diameter area with a monodispersity of 10% was 8%. Thus, cubic silver iodobromide grains having a [100] face ratio of 87% were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting, and then 0.1 g of phenoxyethanol.
Was adjusted to pH 5.9 and pAg 7.5 to obtain a silver halide emulsion A.

(Preparation of organic silver salt dispersion) 4.4 g of arachidic acid, 39.4 g of behenic acid and 770 ml of distilled water
103 ml of 1N-NaOH aqueous solution while stirring at 85 ° C.
Was added over 60 minutes and reacted for 240 minutes, and the temperature was lowered to 75 ° C. Then, an aqueous solution of 12.5 g of silver nitrate 112.5 g
ml over 45 seconds and leave for 20 minutes.
The temperature was lowered to 30 ° C. Then, the solid content was separated by absorption filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. The solid content thus obtained was handled as a wet cake without drying, and 10 g of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .; PVA-205) and water were added to a wet cake equivalent to 100 g of dry solid content, and the total amount was adjusted. After 500 g, it was predispersed with a homomixer.

Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-11OS-EH, manufactured by Microfluidics International Corporation, using G10Z interaction chamber).
The pressure was adjusted to 172 MPa, and the mixture was treated three times to complete the preparation of an organic silver salt microcrystal dispersion having a volume-weighted average diameter of 0.93 μm. Particle size measurements are made using a Malvern I
nstrumentsltd. Master Siz
erX. In the cooling operation, a coiled tube heat exchanger was mounted before and after the interaction chamber, and the temperature of the refrigerant was adjusted to set a desired dispersion temperature.

(Preparation of Emulsion Layer Coating Solution) The silver halide (emulsion A) equivalent to 9 mol% / organic silver was added to the previously prepared organic silver microcrystal dispersion, using the following binders and developing materials. And an emulsion layer coating solution.

(Dispersion of Reducing Agent) The following materials and zirconium oxide beads were placed in a ball mill container, the container was sealed, and dispersed until the average particle size shown in Table 1 was attained. The average particle size referred to here is a value obtained by placing the dispersion on a preparation, placing a thin protective glass on the top to prevent water evaporation, photographing with an optical microscope, and averaging the longest part of the crystal as the particle size. .

Water 300 g Sodium dodecylbenzenesulfonate 3 g Sodium fluorinated octylbenzenecarboxylate 3 g 110 g of the reducing agent in Table 1 20 g of sodium polystyrenesulfonate After the dispersion, the zirconium oxide beads were removed.

(High contrast agent) The above reducing agents were changed to the high contrast agents shown in Table 1 and dispersed in the same manner.

Binder; Luckstar 3307B 470 g as solid content (manufactured by Dainippon Ink and Chemicals, Ltd .; glass transition temperature of 17 ° C. with SBR latex) Reducing agent dispersion shown in Table 1 110 g as solid content Tribromomethylphenylsulfone solid 25 g 3,4-dihydro-4-oxo-1,2,3-benzotriazine 5.2 g as solids Hardener (as shown in Table 1) 20 g as solids (Preparation of coating solution for photosensitive surface protective layer) 262 g of H ₂ O was added to 500 g of a 40% polymer latex (copolymer of methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / methacrylic acid = 59/9/26/5/1) to prepare 14 g of benzyl alcohol, 2.5 g of compound D, 5 4 (Chukyo Yushi (Co.)) 3.6 g, compound E12g, compound f1g, compound G2G, phthalazine compounds shown in Table 1 7.5 g, average particle size 3μ as a matting agent
m of polymethyl methacrylate fine particles were sequentially added, and further, H ₂ O was added to 1000 g, and the viscosity was 5 cP.
(25 ° C.), a coating solution having a pH of 3.4 (25 ° C.) was prepared.

(Dispersion of phthalazine compound) Water 30 g Sodium dodecylbenzenesulfonate 0.2 g Sodium fluorinated octylbenzenecarboxylate 0.2 g 7.5 g of phthalazine compound in Table 1 7.5 g Sodium polystyrenesulfonate 0.5 g

[0190]

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(Preparation of Backing Protective Layer, Backing Layer Coating Solution) (Backing Protective Layer) 40% Polymer Latex (Methyl Methacrylate / Styrene / 2-Ethylhexyl Acrylate / 2-Hydroxyethyl Methacrylate / Methacrylic Acid = 59/9 / 26/5/1 copolymer) 5
Then, 262 g of H ₂ O was added to 00 g, and 14 g of benzyl alcohol, 2.5 g of compound D, 3.6 g of cellosol 524 (manufactured by Chukyo Yushi Co., Ltd.) and 3.6 g of compound E12 were used as film-forming aids.
g, compound F1g, compound G2g, as a matting agent, polymethyl methacrylate fine particles 3.4 having an average particle size of 3 μm.
g in order, and further add H ₂ O to make 1000 g,
A coating solution having a viscosity of 5 cP (25 ° C.) and a pH of 3.4 (25 ° C.) was prepared.

(Preparation of Backing Layer Coating Solution) Dye-C was added to the backing protective layer coating solution at an absorbance at 780 nm of 1.1.
Was added so that

[0193]

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A backing protective layer was applied to a PET support so that the binder content was 0.8 g / m ² . Thereafter, the emulsion layer was coated so that the silver content was 1.45 g / m ² , and the photosensitive surface protective layer was coated so that the binder content was 1.2 g / m ² . 65% by mass of the solvent of the coating solution for the image forming layer (emulsion layer and photosensitive surface protective layer) was water.

(Development processing conditions) Fuji Photo Film Co., Ltd.
A heat developing machine FDS-6100X was used. The configuration consists of a conveyor section, a preheating section, a developing section, and a slow cooling section. The six halogen lamp heaters in the preheating section are 75 ° C, 90 ° C, 105 ° C, 120 ° C, 125 ° C,
It was set at 125 ° C. In the developing section, the same temperature was set for the three aluminum block heaters having a brushed material adhered to the lower side and the three panel heaters further disposed above the upper roller. The temperature of the first roller in the slow cooling section was set to 100 ° C. The display of temperature and time in the column of sensitivity difference shown in Table 1 indicates the temperature of the developing unit and the processing time. Processing was performed with the photosensitive surface facing up.

(Uneven Development) FT-29 manufactured by NEC Corporation
590m with 90% flat screen at 6R (light source wavelength 780nm)
mx 410mm size, and developing temperature 120
C. and a development time of 25 seconds, and the unevenness of the screen was evaluated in 10 steps. 1: Unevenness is conspicuous on the entire surface, and it is unpractical level 5: Unevenness can be visually confirmed in a part, but practically the lower limit level 8: Unevenness is not noticeable at a glance and no practically problematic level 10: No non-uniformity level ( (Linearity) Under thermal development processing conditions of 120 ° C. and 25 seconds, exposure was performed by changing the laser power at a theoretical value of 90% of the halftone output of FT-296R, and after thermal development processing, the halftone dot percentage of the photosensitive material was X-Rite. Was measured. Measured value is 90
The halftone dot having a theoretical value of 50% was exposed at a laser power of%. The exposed photosensitive material was subjected to a heat development treatment, and the dot percentage was measured by X-Rite. The dot percentage after the treatment is shown in Table 1 as linearity. The closer to 50%, the better.

[0197]

[Table 1]

Example 2 (Preparation of Na Behenate Solution) In 945 ml of pure water, 32.4 g of behenic acid, 9.9 g of arachidic acid and 5.6 g of stearic acid were dissolved at 90 ° C. Next, 98 ml of a 1.5 mol / L aqueous sodium hydroxide solution was added while stirring at a high speed. Next, after adding 0.93 ml of concentrated nitric acid,
And stirred for 30 minutes to obtain a sodium behenate solution.

(Preparation of Preform Emulsion of Silver Behenate and Silver Halide Emulsion A) In the above-mentioned sodium behenate solution, the silver halide emulsion A was converted to silver with respect to the total silver salt in 5.2.
Mol%, and the pH is adjusted with sodium hydroxide solution.
After adjusting to 8.1, a 1 mol / L silver nitrate solution 14
7 ml was added over 7 minutes, the mixture was further stirred for 20 minutes, and water-soluble salts were removed by ultrafiltration. Silver behenate was grains having an average grain size of 0.8 μm and a monodispersity of 8%. After the floc of the dispersion was formed, the water was removed, washed with water six times and water was removed, and dried.

(Preparation of Photosensitive Emulsion) The above preform emulsion was divided, and a solution of polyvinyl butyral (average molecular weight: 3000) in methyl ethyl ketone (17% by mass) was prepared.
After 44 g and 107 g of toluene were gradually added and mixed, dispersion was performed at 30 ° C. for 10 minutes at 27 MPa with a media disperser using a 0.5 mm ZrO ₂ bead mill.

The following layers were simultaneously coated on both sides of the support to prepare samples. In addition, drying was performed at 60 ° C. and 1
Performed in 5 minutes.

(Coating on Back Side) A liquid having the following composition was coated on the B-1 layer of the support.

Cellulose acetate butyrate 15 ml / m ² (10% methyl ethyl ketone solution) Dye-A 40 mg / m ² Matting agent: monodispersity 15%, monodisperse silica 90 mg / m ² C ₈ F ₁₇ (average particle size 8 μm) CH ₂ CH ₂ O) ₁₂ C ₈ F ₁₇ 50 mg / m ² C ₉ F ₁₉ —C ₆ H ₄ —SO ₃ Na 10 mg / m ² No dye-A was added to 1-4.

[0204]

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(Coating on Photosensitive Layer Side) A solution having the following composition was coated on the A-1 layer of the support so that the coated silver amount was 1.5 g / m ² .

The photosensitive emulsion 240 g Sensitizing dye (0.1% methanol solution) 1.7 ml Pyridinium bromide perbromide (6% methanol solution) 3 ml Calcium bromide (0.1% methanol solution) 1.7 ml Oxidizing agent (10% methanol solution) 1.2 ml 2-4-chlorobenzoylbenzoic acid (12% methanol solution) 9.2 ml 2-mercaptobenzimidazole (1% methanol solution) 11 ml tribromomethylsulfoquinoline (5% methanol solution) 17 ml Hardening agent Partitioned between emulsion layer and emulsion protective layer as shown in Table 2, 50 mg / m ² phthalazine as shown in Table 2 Partitioned between emulsion layer and emulsion protective layer as shown in Table 2, and combined with 80 mg / m ² 4- Methylphthalic acid 0.25 g Tetrachlorophthalic acid 0.2 g Calcium carbonate with average particle size of 3 μm 0.1 g Reducing agent As shown in Table 2, the emulsion was distributed between the emulsion layer and the emulsion protective layer, and the total amount was 1.0 g / m ² isocyanate compound 0.5 g (Desmodur N3300 manufactured by Mobay Corporation).

[0207]

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(Coating of Surface Protective Layer) A solution having the following composition was simultaneously coated on the photosensitive layer.

[0209] partitioned emulsion layer and the emulsion protective layer as shown in acetone 5 ml / m ² methyl ethyl ketone 21 ml / m ² Cellulose acetate butyrate 2.3 g / m ² methanol 7 ml / m ² high contrast agent Table 2, together 50mg / M ² reducing agent Partitioned into emulsion layer and emulsion protective layer as shown in Table 2, combined 1.0 g / m ² phthalazine Partitioned into emulsion layer and emulsion protective layer as shown in Table 2, combined 80 mg / m ² m ² matting agent: monodispersity 10%, monodisperse silica having an average particle size of 4 μm 5 mg / m ² CH ₂ ＣＨCHSO ₂ CH ₂ CH ₂ OCH ₂ CH ₂ SO ₂ CH = CH ₂ 35 mg / m ² Fluorine-based surface activity Agent C ₁₂ F ₂₅ (CH ₂ CH ₂ O) ₁₀ C ₁₂ F ₂₅ 10 mg / m ² C ₈ F ₁₇ —C ₆ H ₄ —SO ₃ Na 10 mg / m ² Removed To, was measured in electron microscopy in the replica method,
The organic silver salt particles have a monodispersity of 0.5 ± 0.05 μm in major axis, 0.4 ± 0.05 μm in minor axis, and 0.01 μm in thickness, and 90% of all organic silver salt particles. % Particles.

[0210]

[Table 2]

The same content as that of the protective layer is coated under the emulsion layer to form a lower layer / emulsion layer / protective layer from the support side, and a reducing agent, a high contrast agent, and a phthalazine compound are also distributed or provided in the lower layer. The same effect was obtained even when the entire amount was added.

[0212]

According to the present invention, it is possible to provide a photothermographic material in which the sensitivity fluctuation due to the processing time and the processing temperature is small, and the development unevenness and the linearity are improved.

Claims (2)

[Claims] 1. A photothermographic material comprising an organic silver salt, a photosensitive silver halide, a reducing agent and a high contrast agent on a support, a reducing agent having an average particle size of 0.15 to 0.80 μm. A photothermographic material, characterized in that the image forming layer is coated with a coating solution in which the agent and the phthalazine compound are dispersed in a particle form, and the solvent is water at 60% by mass or more. 2. A photothermographic material comprising an organic silver salt, a photosensitive silver halide, a reducing agent and a contrast agent on a support, wherein the photothermographic material comprises a reducing agent, a contrast agent and a phthalazine compound. At least two kinds of the layers other than the silver halide emulsion layer with respect to the total value (m + p) of the addition amount (m) to the silver halide emulsion layer and the addition amount (p) to the layer other than the silver halide emulsion layer Ratio p / (m +)
p) is from 0.1 to 1.0.