JP2002122958A - Heat developable photosensitive material, image recording method and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material having high sensitivity, less liable to cause fog and also having improved raw stock preservability (preservability before exposure and development) and improved silver image preservability after development and to provide an image recording method and an image forming method. SOLUTION: In the heat developable photosensitive material with a photosensitive layer containing an organic silver salt, a binder, photosensitive silver halide grains, non-photosensitive silver halide grains and an infrared dye on the base, the photosensitive silver halide grains are formed at <=30 deg.C and chemically sensitized with a chalcogen sensitizer of formula (I-1) or (I-2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material which forms an image by heat development, and more particularly, to high sensitivity, low fogging, raw preservability (preservation before exposure and development) and development. The present invention relates to a photothermographic material having improved silver image preservability after processing, an image recording method, and an image forming method.

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical care,
Waste liquids associated with wet processing of image forming materials have become a problem in terms of workability. In recent years, it has been strongly desired to reduce the amount of processing waste liquids from the viewpoint of environmental conservation and space saving. Therefore, there has been a need for a technique relating to a photothermographic material for photographic technology, which enables efficient exposure with a laser imagesetter or laser imager and can form a high-resolution, clear black image.

As a technique therefor, a heat-developable photographic material for forming a photographic image by using a heat-development processing method is disclosed in, for example, US Pat. Nos. 3,152,904 and 3,457,075 or "Processed by heat." Silver system (Therma
llly Processed Silver System
ms) "｛(Imaging Processors and
Materials (Imaging Processes)
and Materials) Neblette, 8th
Plate; Sturge, V .; Walworth, A .; Shepp, p. 279, 1969).

These heat-developable photographic materials usually use a photosensitive silver halide particle provided in a photosensitive layer as an optical sensor, an organic silver salt as a supply source of silver ions, and a built-in reducing agent. It is characterized in that an image is formed by heat development at a temperature of 140 ° C. and no fixing is performed. Therefore, in order to achieve both a smooth supply of silver ions to the silver halide and a prevention of a decrease in transparency due to light scattering, it is easy to properly arrange in the photosensitive layer, and to improve the shape of organic silver particles that have little adverse effect on light scattering. A lot of effort has been made.

[0005] However, in order to achieve the above-mentioned object, simply dispersing and / or pulverizing with a high energy using a dispersing machine or the like, to simply atomize the particles, silver halide grains and organic silver salt grains are used. The fog rises due to the damage of the lens, the sensitivity decreases, and other problems such as deterioration of the image quality occur, so that high light sensitivity without increasing the amount of silver,
There has been a demand for a technique capable of obtaining an image density and reducing fog.

On the other hand, a photothermographic material contains an organic silver salt, photosensitive silver halide particles, and a reducing agent. There is also a problem that fog or photo-decomposed silver (print-out silver) is apt to occur during the storage period after the development processing. In particular, the photothermographic material is usually 80 to 2 after exposure.
Since heat development is only performed at 50 ° C. and no fixing is performed, the silver image discolors due to heat or light during long-term storage under conditions where silver halide, organic silver salt and reducing agent remain in unexposed areas. Was a problem.

That is, the presence of a reducing agent in the light-sensitive material facilitates the generation of heat fog due to the reaction with the organic silver salt, and the wavelength range different from the light for image recording after development. In a system containing silver halide grains and an organic silver salt, printout silver is used because the reducing agent functions as a hole trap in addition to the original function of reducing silver ions even when irradiated with light. Is considered to be part of the cause.

[0008] In addition to the above-mentioned causes, it is conceivable that fog nuclei causing fog are formed in the manufacturing process of the photosensitive material.

Techniques for solving these problems are disclosed in JP-A-6-208192, JP-A-8-267934, US Pat. No. 5,714,311 and references cited in these patent documents. However, although these disclosed technologies have a certain degree of effect, they are still not enough to satisfy the level required in the market.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a high-sensitivity, low-fogging, raw storage (storage before exposure and development processing) To provide a photothermographic material, an image recording method, and an image forming method, which have improved silver image storability after development.

[0011]

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

In a photothermographic material having a photosensitive layer containing an organic silver salt, a binder, photosensitive silver halide grains, non-photosensitive silver halide grains and an infrared dye on a support, the photosensitive silver halide The particles are formed at a temperature of 30 ° C. or lower, and have the general formula (I-1):
A photothermographic material which has been chemically sensitized with a chalcogen sensitizer represented by the general formula (2).

When forming the photosensitive silver halide grains, use is made of low-molecular-weight gelatin having an average molecular weight of 50,000 or less.
Reacting an organic silver with a halide ion source at a temperature of 0 ° C. or less to prepare substantially non-photosensitive silver halide grains; a photosensitive halogen formed using low molecular weight gelatin having an average molecular weight of 50,000 or less; The molar ratio of substantially non-photosensitive silver halide grains prepared by reacting a halide ion source with organic silver at a temperature of 20 ° C. or less to silver halide grains is 0.15 to 1, The halide ion source is a compound represented by the general formula (II), the photosensitive silver halide grains contain at least one transition metal selected from Group 6 to 11 elements of the periodic table, Is a metal selected from the group consisting of iron, cobalt, ruthenium, rhodium, rhenium, osmium and iridium.

An image recording method in which the photothermographic material is exposed by a laser exposing machine in which an angle between an exposure surface of the photothermographic material and a scanning laser beam does not become substantially perpendicular. An image recording method in which a scanning laser beam for recording an image on a developed photosensitive material is exposed by a laser exposing machine having a vertical multi-layer, and the above-described photothermographic material is
The object of the present invention is also achieved by an image forming method of heating and developing at -200 ° C.

Hereinafter, the present invention will be described in detail in the order of an organic silver salt, a photosensitive silver halide, a chalcogen sensitizer, a reducing agent, a binder, and a useful additive.

In the present invention, the organic silver salt is a reducible silver source, and is preferably a silver salt of an organic acid or a heteroorganic acid, particularly a long-chain (10-30, preferably 15-25) aliphatic carboxylic acid and Silver salts of nitrogen-containing heterocyclic compounds are preferred. The ligand has a total stability constant for silver ions of 4.0 to 1
Research Disclosure (hereinafter RD) having a value of 0.0
Organic or inorganic complexes described in 17029 and 29963 are also preferred. Examples of these suitable silver salts include the following.

Silver salts of organic acids (silver salts such as gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid and lauric acid); carboxyalkylthiourea salt of silver (1- (3-carboxypropyl) thio Urea, 1- (3
-Carboxypropyl) -3,3-dimethylthiourea, etc.); silver salts or complexes of polymer reaction products of aldehydes with hydroxy-substituted aromatic carboxylic acids [aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted aromatic Carboxylic acids (salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,
Silver salt or complex of a reaction product of 5-thiodisalicylic acid, etc.); silver salt or complex of thiones [3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2
-Thione, 3-carboxymethyl-4-thiazoline-2
-Thione, etc.], imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole,
Complexes or salts of silver with 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 of mercaptan derivatives salt.

Of the above organic silver salts, silver salts of fatty acids are preferably used, and more preferably silver behenate, silver arachidate and / or 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, but a forward mixing method, a reverse mixing method, a simultaneous mixing method and the like are preferably used. Further, a controlled double jet method as described in JP-A-9-127463 is preferably used. For example, an organic acid alkali metal salt soap (sodium behenate, sodium arachidate, etc.) is prepared by adding an alkali metal salt (sodium hydroxide, potassium hydroxide, etc.) to an organic acid, and then controlled by a controlled double jet method. A soap and silver nitrate are mixed to produce an organic silver salt crystal. At that time, silver halide grains may be mixed.

The organic silver salt can be used in various shapes, but tabular grains are preferred. In particular, it is a tabular organic silver salt particle having an aspect ratio of 3 or more, and the shape anisotropy of two substantially parallel facing surfaces (principal planes) having the largest area is reduced to fill the photosensitive layer. In order to carry out, the average value of the needle-like ratio of the tabular organic silver salt particles measured from the main plane direction is preferably 1.1 or more and less than 10. In addition, a more preferable needle ratio is 1.1 or more and less than 5.0.

In the present invention, having tabular organic silver salt grains having an aspect ratio of 3 or more means that the tabular organic silver salt grains account for 50% or more of the total number of organic silver salt grains. Furthermore, in the present invention, tabular organic silver salt grains having an aspect ratio of 3 or more account for 60% of the total number of organic silver salt grains.
Preferably, it accounts for at least 70% (number), more preferably at least 80% (number).
It is.

The tabular grains having an aspect ratio of 3 or more are grains having a ratio of an average particle diameter to an average thickness, that is, an aspect ratio (abbreviated as AR) represented by the following formula of 3 or more.

AR = average particle size (μm) / average thickness (μ
m) The aspect ratio of the tabular organic silver salt particles according to the invention is preferably from 3 to 20, and more preferably from 3 to 10. The reason is that if the aspect ratio is too low, the organic silver salt particles are likely to be densest, and if the aspect ratio is too high, the organic silver salt particles are likely to overlap with each other,
The above range is considered to be a preferable range because light scattering and the like are likely to occur because the light-sensitive material is easily dispersed in the state of being adhered to the light-sensitive material.

In order to determine the above average particle size, the organic silver salt after dispersion is diluted and dispersed on a grid with a carbon support film, and the transmission electron microscope (2000FX, manufactured by JEOL Ltd.) is used.
), And photographed directly at a magnification of 5000 times. The negative was captured as a digital image by a scanner, and the average particle diameter was calculated by measuring 300 or more particle diameters (equivalent circle diameter) using appropriate image processing software.

The above average thickness was determined by a method using a TEM (transmission electron microscope) as shown below.

First, the photosensitive layer applied on the support is attached to an appropriate holder with an adhesive, and the thickness of the photosensitive layer is set to 0.1 to 0.
Make ultra-thin sections of 2 μm. The prepared ultra-thin section is
Transferred electron microscope (hereinafter referred to as TEM) while supporting on a copper mesh, transferring onto a carbon film hydrophilized by glow discharge, and cooling to -130 ° C or lower with liquid nitrogen.
Is used to observe a bright-field image at a magnification of 5,000 to 40,000, and the image is quickly recorded on a film, an imaging plate, a CCD camera, or the like. At this time, as the visual field to be observed, it is preferable to appropriately select a portion where there is no break or looseness in the section.

An extremely thin collodion as a carbon film,
It is preferable to use one supported on an organic film such as formvar, more preferably, by forming on a rock salt substrate and dissolving and removing the substrate, or by removing the organic film by an organic solvent and ion etching. This is a film of the obtained carbon alone. The accelerating voltage of TEM is 80-40
0 kV is preferable, and particularly preferably 80 to 200 kV.

As for the TEM image recorded on a suitable medium, as in the measurement of the thickness of the organic silver salt particles, one image is composed of at least 1024 pixels × 1024 pixels, preferably 20 pixels.
It is preferable to decompose the image into 48 pixels × 2048 pixels or more and perform image processing by a computer. In order to perform image processing, it is preferable that an analog image recorded on a film is converted into a digital image by a scanner or the like, and shading correction, contrast / edge enhancement, and the like are performed as necessary. Thereafter, a histogram is created, and a portion corresponding to organic silver is extracted by a binarization process. The thickness of the extracted organic silver salt particles was 300 or more, and the average value was obtained by manual measurement using appropriate software.

The average value of the acicular ratio of the tabular organic silver salt particles can be determined by the following method. First, the photosensitive layer containing the tabular organic silver salt particles is swollen with an organic solvent capable of dissolving the photosensitive layer binder, peeled off from the support, and subjected to ultrasonic cleaning, centrifugation, and supernatant removal using the solvent. Repeat 5 times. The above steps are performed under safelight.

Subsequently, the mixture was diluted with MEK (methyl ethyl ketone) so that the organic silver solid content concentration became 0.01%.
After ultrasonic dispersion, PE hydrophilized by glow discharge
It is dropped on a T (polyethylene terephthalate) film and dried.

The film on which the particles are mounted is formed by obliquely vapor-depositing 3 nm thick Pt—C with an electron beam from a 30 ° angle with respect to the film surface using a vacuum vapor deposition apparatus.
It is preferably used for observation.

For details of the electron microscopy technique and the sample preparation technique, see "Japan Society of Electron Microscopy Kanto Chapter / Medical and Biological Electron Microscopy" (Maruzen), "Japan Electron Microscopy Society Kanto Section / Electronics". Microscopic biological sample preparation method ”(Maruzen) can be referred to.

The prepared sample was subjected to an acceleration voltage of 2 using a field emission scanning electron microscope (hereinafter referred to as FE-SEM).
The secondary electron image is observed at a magnification of 5,000 to 20,000 times at ４4 kV, and the image is stored on an appropriate recording medium.

For the above processing, it is convenient to use a device capable of AD-converting an image signal from the electron microscope main body and recording it directly as digital information on a memory. The recorded analog image can also be used by converting it into a digital image using a scanner or the like and performing shading correction, contrast / edge enhancement, and the like as necessary.

As for the image recorded on a suitable medium, one image is formed of at least 1024 × 1024 pixels, preferably 2048 × 20, as in the measurement of the thickness of the organic silver salt particles.
It is preferable to decompose the image into 48 pixels or more and perform image processing by a computer.

As a procedure of the above image processing, first, a histogram is prepared, and a portion corresponding to organic silver salt particles having an aspect ratio of 3 or more is extracted by binarization. The unavoidably agglomerated particles are cut by a suitable algorithm or manual operation to perform contour extraction. Thereafter, the maximum length of each particle (MX LNG) and the minimum width of the particle (WIDT)
H) is measured for at least 1,000 particles, and the acicular ratio is determined for each particle by the following formula. The maximum length of a particle refers to the maximum value when two points in the particle are connected by a straight line. The minimum width of a particle means a value when a distance between the parallel lines becomes a minimum value when two parallel lines circumscribing the particle are drawn.

Needle ratio = (MX LNG) ÷ (WIDT
H) Then, the average value of the needle ratios of all the measured particles is calculated. When the measurement is performed in the above procedure, it is preferable that the length correction per pixel (scale correction) and the correction of the two-dimensional distortion of the measurement system be sufficiently performed using a standard sample in advance.

As a standard sample, Uniform Latex Particles (DULP), commercially available from Dow Chemical Company, USA, has a coefficient of variation of less than 10% for a particle size of 0.1 to 0.3 μm. Polystyrene particles are preferred, and a lot having a specific particle size of 0.212 μm and a standard deviation of 0.0029 μm is available.

The method for obtaining the organic silver salt particles having the above-mentioned shape is not particularly limited, but the mixed state at the time of forming the organic acid alkali metal salt soap and / or the mixed state at the time of adding silver nitrate to the soap is excellent. It is effective to maintain and optimize the proportion of silver nitrate that reacts with the soap.

The projection area of the organic silver particles having the specific projection area value as described above and the ratio of the organic silver particles to the total projection area are as follows.
In the same manner as described in the section for determining the average thickness of the tabular grains having an aspect ratio of 3 or more, a section corresponding to organic silver is extracted by a method using a TEM (transmission electron microscope).

At this time, the aggregated organic silver is treated as one particle, and the area (AREA) of each particle is determined.
Similarly, at least 1,000, preferably 2,000
The area was determined for 00 particles, and for each,
A: 0.025 .mu.m less than ^2, B: 0.025μm ² or more 0.2 [mu] m less than ^2, C: classified into 0.2 [mu] m ² or more of the three groups. In the light-sensitive material of the present invention, the total area of the particles belonging to Group A is 70% or more of the measured area of all the particles;
In addition, the total area of the particles belonging to the group C satisfies 10% or less of the measured area of all the particles.

When the measurement is performed in the above procedure, it is preferable that the length correction (scale correction) per pixel and the correction of the two-dimensional distortion of the measurement system be sufficiently performed using a standard sample in advance. As a standard sample, Uniform Latex Particles (DUL) commercially available from Dow Chemical Company, USA
P) is appropriate, and 10 for a particle size of 0.1 to 0.3 μm.
% Is preferable, and specifically, the particle diameter is 0.212 μm, and the standard deviation is 0.00.
Lots of 29 μm are available.

The details of the image processing technology can be referred to "Hiroshi Tanaka: Image Processing Applied Technology (Industrial Research Committee)".
The image processing program or device is not particularly limited as long as the above operation can be performed, and an example is Luzex-III manufactured by Nireco.

The organic silver salt particles of the photosensitive emulsion of the present invention according to claim 1 or the photothermographic material of claim 3 are preferably monodisperse particles, and the monodispersity is preferably 1%. To 30%, and by using monodispersed particles in this range, an image having a high density can be obtained. Here, the monodispersion is defined by the following equation.

Monodispersity = (standard deviation of particle size / average of particle size) × 100 The average particle size of the organic silver salt is preferably 0.01 to 0.8 μm, more preferably 0.05 to 0.5 μm. And the average particle diameter (equivalent circle diameter) represents the diameter of a circle having the same area as an individual particle image observed with an electron microscope.

The conditions for preparing a photosensitive emulsion having the above-mentioned characteristics are not particularly limited, but include a mixed state when forming an organic acid alkali metal salt soap and / or a mixed state when adding silver nitrate to the soap. And to optimize the proportion of silver nitrate that reacts with the soap,
For dispersion and pulverization, use a media disperser or high-pressure homogenizer to disperse the binder. At this time, the binder concentration should be 0.1 to 10% of the mass of the organic silver, and the temperature from drying to completion of the dispersion should not exceed 45 ° C. In addition to the above, preferable conditions include stirring at a peripheral speed of 2.0 m / sec or more using a dissolver during liquid preparation.

It is preferable that the tabular organic silver salt particles are preliminarily dispersed together with a binder, a surfactant and the like, if necessary, and then dispersed and ground using a media disperser or a high-pressure homogenizer. For the preliminary dispersion, a general stirrer such as an anchor type or a propeller type, a high-speed rotary centrifugal radiation type stirrer (dissolver), and a high-speed rotary shear type stirrer (homomixer) can be used.

As the media dispersing machine, a rolling mill such as a ball mill, a planetary ball mill, and a vibrating ball mill, a bead mill, an attritor, and a basket mill as a medium stirring mill can be used, and a high-pressure homogenizer can be used. Various types can be used, such as a type that collides with a wall, a plug, or the like, a type in which liquid is divided into a plurality of pieces and then collides with each other at a high speed, and a type that passes through a thin orifice.

As ceramics used for the ceramic beads used at the time of media dispersion, for example, A
l ₂ O ₃ , BaTiO ₃ , SrTiO ₃ , MgO, ZrO,
_{BeO, Cr 2 O 3, SiO} 2, SiO 2 -Al 2 O 3, Cr
₂ O ₃ -MgO, MgO-CaO, MgO-C, MgO-
Al ₂ O ₃ (spinel), SiC, TiO ₂ , K ₂ O, Na
₂ O, BaO, PbO, B ₂ O ₃ , SrTiO ₃ , BeAl
_{2 O 4, Y 3 Al 5} O 12, ZrO 2 -Y 2 O 3 ( cubic _{zirconia), 3BeO-Al 2 O 3} -6SiO 2 ( Synthesis emerald), C (diamond), Si ₂ O-nH ₂ O,
Preferred are silicon nitride, yttrium-stabilized zirconia, zirconia-reinforced alumina, and the like. Due to the small amount of impurities generated due to friction with beads and disperser during dispersion,
Yttrium-stabilized zirconia and zirconia-reinforced alumina (these ceramics containing zirconia are hereinafter abbreviated as zirconia) are particularly preferably used.

In the apparatus used for dispersing the tabular organic silver salt particles, ceramics such as zirconia, alumina, silicon nitride, boron nitride, or diamond is used as a material of a member with which the organic silver salt particles come into contact. It is preferable to use zirconia.

In carrying out the above dispersion, the binder concentration is preferably 0.1 to 10% of the mass of the organic silver, and it is preferable that the liquid temperature does not exceed 45 ° C. from the preliminary dispersion to the main dispersion. In addition, preferable operating conditions of the main dispersion include:
For example, when using a high-pressure homogenizer as a dispersion means,
29.42 to 98.06 MPa, and the number of operations is preferably two or more. When a media dispersing machine is used as the dispersing means, the peripheral speed is preferably 6 to 13 m / sec.

Further, zirconia can be used for a part of beads or members, and can be mixed into a dispersed emulsion at the time of dispersion.
This is preferable in terms of photographic performance. Zirconia fragments may be added later to the dispersion emulsion, or may be added in advance during the preliminary dispersion. Although a specific method is not particularly limited, as an example, a high-concentration zirconia solution can be obtained by circulating MEK through a bead mill filled with zirconia beads. It may be added at a preferable time and at a preferable concentration.

Next, the photosensitive silver halide according to the present invention will be described. The photosensitive silver halide in the present invention functions as an optical sensor.

In order to suppress white turbidity after image formation and obtain good image quality, the average grain size of the photosensitive silver halide grains is preferably small, and the average grain size is preferably 0.1 μm or less, more preferably. 0.01-0.1μ
m, particularly preferably 0.02 to 0.08 μm. Here, the particle size refers to the diameter (equivalent circle diameter) of a circle having the same area as an individual particle image observed with an electron microscope.
Further, the silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion obtained by the following equation is 40.
Say less than%. The particle size is more preferably 30% or less, and particularly preferably 20% or less.

Monodispersity = (standard deviation of grain size / average of grain size) × 100 The shape of silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane is high. Preferably, this proportion is at least 50%, more preferably at least 70%,
In particular, it is preferably at least 80%. Miller index [1
The ratio of the [00] plane is determined by utilizing the dependence of the adsorption of the sensitizing dye on the [111] plane and the [100] plane. Tan
i: J. Imaging Sci. , 29, 165 (1
985).

Another preferred form of silver halide is tabular grains. The term "tabular grain" as used herein means that the thickness in the vertical direction is h.mu.
It means that the aspect ratio (r / h) is 3 or more when m is set. Among them, the aspect ratio is preferably 3 to 5
0. The particle size is preferably 0.1 μm or less, and more preferably 0.01 to 0.08 μm. These are disclosed in U.S. Pat. Nos. 5,264,337 and 5,314,7.
No. 98, 5,320, 958, etc.
The desired tabular grains can be easily obtained.

The halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. The photographic emulsion used in the present invention is P.I. Chimie et P by Glafkids
hysique Photographique (Pa
ul Montel, 1967); F. Du
Photographic Emulsi by fin
on Chemistry (The Focal Pr
ess, 1966); L. Zelikman
Making and Coating by et al
Photographic Emulsion (The
Focal Press, 1964) and the like. That is, any of an acidic method, a neutral method, an ammonia method, etc. may be used.
Any of a one-side mixing method, a simultaneous mixing method, a combination thereof and the like may be used.

The silver halide used in the present invention preferably contains metal ions belonging to groups 6 to 11 of the periodic table. The above metals include W, Fe, Co, N
i, Cu, Ru, Rh, Pd, Re, Os, Ir, P
t and Au are preferred.

These metal ions can be introduced into silver halide in the form of a metal complex or a metal complex ion. As these metal complexes or metal complex ions, six-coordinate metal complexes represented by the following general formula are preferable.

In the formula [ML ₆ ] ^m , M is a transition metal selected from elements of Groups 6 to 11 of the periodic table, L is a ligand, and m is 0,-, 2-, 3- or 4- Represents Specific examples of the ligand represented by L include halides (fluoride, chloride, bromide and iodide), cyanide, cyanate, thiocyanate, selenocyanate,
Terrocyanate, each ligand of azide and aquo, nitrosyl, thionitrosyl and the like, preferably aquo,
And nitrosyl and thionitrosyl. If an aquo ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

Particularly preferred examples of M are rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os).

The following are specific examples of transition metal complex ions, but the present invention is not limited to these.

[0063] 1: [RhCl _6] ^3- 2: [RuCl _6] ^3- 3: [ReCl _6] ^3- 4: [RuBr _6] ^3- 5: [OsCl _6] ^3- 6: [IrCl _6] ^{4 -} 7: [Ru (NO) Cl _5] ^2- 8: [RuBr ₄ (H ₂ O)] ^2- 9: _{[Ru (NO) (H 2 O} ) Cl 4 ] ^- 10: [RhCl ₅ (H ₂ O)] ^2- 11: [Re (NO) C _l5 ^2- 12: [Re (NO) (CN) _5] ^2- 13: [Re (NO) Cl (CN) 4 ] ^2- 14: [Rh (NO) ₂ Cl _4] ^- 15: _{[Rh (NO) (H 2 O} ) Cl 4 ] ^- 16: [Ru (NO) (CN) _5] ^2- 17: [Fe (CN) _{6] 3-} 18 : [Rh (NS) Cl _5] ^2- 19: [Os (NO) Cl _5] ^2- 20: [Cr (NO) Cl _5] ^2- 21: [Re (NO) Cl _5] ^- 22: [Os (NS) Cl ₄ (TeCN)] ^2- 23: [Ru (NS) Cl _5] ^2- 24: _{[Re (NS) Cl 4 (SeCN} ) ] ^2- 25: [Os (NS) Cl (SCN) 4 ] ^2- 26: [Ir (NO) Cl ₅ ] ^2-27 : [Ir (NS) Cl ₅ ] ^2- These metal ion, metal complex or metal complex ion is 1
They may be of the same type, or two or more of the same and different metals may be used in combination. The content of these metal ions, metal complexes or metal complex ions, generally is suitably 1 × 10 ^-9 ~1 × 10 ^-2 mol per mol of silver halide, preferably 1 × 10 ^{- It is 8} to 1 × 10 ^-4 mol.

The compounds providing these metals are preferably added during silver halide grain formation and incorporated into silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, physical ripening, and chemical ripening are carried out. It may be added at any stage before and after sensitization, but is particularly preferably added at the stage of nucleation, growth, and physical ripening, more preferably at the stage of nucleation and growth, most preferably. Is added at the stage of nucleation.

In the addition, the compound may be added in several divided portions, may be added uniformly in the silver halide grains, or may be added to silver halide grains.
-306236, 3-167545, 4-76
No. 534, No. 6-110146, No. 5-273683
As described in Japanese Patent Application Laid-Open No. H10-284, etc., the particles can be contained in the particles with a distribution. Preferably, a distribution can be provided inside the particles.

These metal compounds can be prepared from water or a suitable organic solvent (alcohols, ethers, glycols,
Ketones, esters and amides). For example, an aqueous solution of a powder of a metal compound or an aqueous solution of a metal compound and sodium chloride or potassium chloride dissolved therein may be added to the aqueous solution during particle formation. Silver halide grains are added in a neutral silver salt solution or a water-soluble halide solution, or when the silver salt solution and the halide solution are simultaneously mixed, they are added as a third aqueous solution, and the three-solution simultaneous mixing method is used. , A method in which a required amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or another silver halide grain doped with metal ions or complex ions in advance during silver halide preparation. And dissolve it. In particular, a method of adding an aqueous solution of a powder of a metal compound or an aqueous solution in which a metal compound is dissolved together with sodium chloride and potassium chloride to a water-soluble halide solution is preferable.

When added to the surface of the particles, immediately after the formation of the particles, during or during physical ripening, at the end of the ripening, or during the chemical ripening,
A required amount of an aqueous solution of a metal compound can be charged into the reaction vessel.

The photosensitive silver halide grains may or may not be desalted after grain formation. When desalting is performed, washing with a water known in the art such as a noodle method or a flocculation method is performed. To desalinate.

The photosensitive silver halide grains of the present invention have a temperature of 30 ° C.
It is preferably prepared at the following temperature, particularly preferably from 10 to 20 ° C.

Further, the silver halide grains are preferably prepared using low molecular weight gelatin having an average molecular weight of 50,000 or less at the time of forming the grains, and particularly preferably used at the time of forming nuclei of the silver halide grains. The low molecular weight gelatin has an average molecular weight of 50,000 or less, preferably from 2000 to 40%.
000, and more preferably 5,000 to 25,000. The average molecular weight of gelatin can be measured by gel filtration chromatography.

The low-molecular-weight gelatin may be enzymatically decomposed by adding a gelatin-degrading enzyme to a commonly used aqueous gelatin solution having an average molecular weight of about 100,000, or may be hydrolyzed by adding an acid or an alkali and heating, or under atmospheric pressure or pressure. , Or by irradiation with ultrasonic waves, or by using these methods in combination.

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

In the present invention, in addition to the photosensitive silver halide grains, a halogen-containing compound is allowed to act on an organic silver salt, and substantially non-photosensitive silver halide grains are mixed by conversion of the organic silver salt. It is also possible.

In the present invention, it is preferable to prepare a substantially light-insensitive silver halide grain by reacting a halogen-containing compound with an organic silver salt at a temperature of 20 ° C. or lower. Particularly preferably, it is 5 to 15 ° C.

The silver halide forming component includes inorganic halogen compounds, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. Specific examples thereof are described in US Pat. 0
No. 39, No. 3,457,075, No. 4,003,74
No. 9, British Patent No. 1,498,956 and
Nos. 27027 and 53-25420, inorganic halides such as metal halides and ammonium halides such as trimethylphenylammonium bromide and cetylethyldimethylammonium bromide;
Onium halides such as trimethylbenzylammonium bromide, for example, iodoform, bromoform,
Halogenated hydrocarbons such as carbon tetrachloride and 2-bromo-2-methylpropane; N-halogen compounds such as N-bromosuccinimide, N-bromophthalimide and N-bromoacetamide; and triphenylmethyl chloride, odor Triphenylmethyl chloride, 2-bromoacetic acid, 2-bromoethanol, dichlorobenzophenone and the like. Particularly preferred is a compound represented by the general formula (II).

These silver halide grains were prepared in an amount of 0.001 to 1 mol per mole of the organic silver salt, both separately prepared silver halide grains and silver halide grains obtained by conversion of the organic silver salt.
It is preferred to use from .about.0.7 mol, preferably from 0.03 to 0.5 mol.

The most preferred combination is substantially prepared by reacting a halide ion source with organic silver at a temperature of 20 ° C. or less with respect to a photosensitive silver halide formed using low molecular weight gelatin having an average molecular weight of 50,000 or less. In particular, the molar ratio of the non-photosensitive silver halide grains is adjusted to be 0.15 to 1.

Next, chemical sensitization by a chalcogen sensitizer will be described. In the photothermographic material of the present invention, the photosensitive silver halide emulsion is chemically sensitized with at least one chalcogen sensitizer represented by formula (I-1) or (I-2). It is characteristic.

In the general formula (I-1), Z ₁ ,
The aliphatic group represented by Z ₂ , Z ₃ , R ₁ , R ₂ , R ₃ , R ₄ and R ₅ is a linear, branched or cyclic alkyl group, alkenyl group, alkynyl group, aralkyl group. Specifically, methyl, ethyl, propyl, i-propyl, t-butyl, butyl, octyl, decyl, hexadecyl, cyclopentyl, cyclohexyl, allyl, 2-butenyl, 3-pentenyl, propargyl, 3-pentynyl, benzyl, phenethyl and the like Each group is mentioned.

The aromatic group represented by Z ₁ , Z ₂ , Z ₃ , R ₁ , R ₂ , R ₃ , R ₄ and R ₅ is a monocyclic or condensed aryl group (phenyl, pentafluorophenyl, 4-chlorophenyl, 3-sulfophenyl, α-naphthyl, 4-methylphenyl, etc.), and the heterocyclic group is a saturated or unsaturated 3- to 10-membered atom containing at least one of a nitrogen atom, an oxygen atom and a sulfur atom. Saturated heterocyclic groups (pyridyl, thienyl,
Furyl, thiazolyl, imidazolyl, benzimidazolyl, etc.).

The cation represented by R ₁ , R ₄ and R ₅ is
It is an alkali metal atom or ammonium.

In the compound of the general formula (I-1), preferably, Z ₁ , Z ₂ or Z ₃ is an aliphatic group, an aromatic group or —O
R ₁ , wherein R ₁ is an aliphatic group or an aromatic group.

The ring which may be formed by combining two of Z ₁ , Z ₂ and Z ₃ with each other may be a 5- to 7-membered (condensed)
And heterocycles.

In the above formula (I-2), Z ₄ and Z ₅ each represent an alkyl group (methyl, ethyl, t-butyl, adamantyl, t-octyl, etc.), an alkenyl group (vinyl, propenyl, etc.), aralkyl Groups (benzyl,
Phenethyl), an aryl group (phenyl, pentafluorophenyl, 4-chlorophenyl, 3-nitrophenyl, 4-octylsulfamoylphenyl, α-naphthyl, etc.), a heterocyclic group (pyridyl, thienyl, furyl, imidazolyl, etc.), -NR ₆ (R _7), - represents a oR ₈ or -SR _9. R ₆ , R ₇ , R ₈ and R ₉ may be the same or different and each represents an alkyl group, an aralkyl group, an aryl group or a heterocyclic group. The alkyl group, an aralkyl group, the aryl group or heterocyclic group, the same examples as Z ₁ in the general formula (I-1) can be mentioned. However, R ₆ and R ₇ are a hydrogen atom or an acyl group (acetyl, propanoyl, benzoyl, heptafluorobutanoyl, difluoroacetyl, 4-nitrobenzoyl, α-naphthoyl,
4-trifluoromethylbenzoyl). Examples of the ring which may be formed by bonding Z ₄ and Z ₅ to each other include a 5- to 7-membered (condensed) heterocyclic ring.

The chalcogen sensitizer represented by the general formula (I-1) or (I-2) reacts with silver ions in silver halide grains to form a sensitizing nucleus regardless of the presence of an oxidizing agent. Can be formed and chemically sensitized.

The amount of the chalcogen sensitizer used is not uniform depending on the type of the sensitizer used, silver halide grains, chemical sensitization environment, etc., but it is generally 10 ⁻ per mol of the total amount of silver halide and organic silver. ^It is preferably from ⁸ to 10 ^-2 mol, more preferably from 10 ^-5 to 10 ^-3 mol. Although there is no particular limitation on the chemical sensitizing environment, the pH is preferably 4 to 10, and more preferably 5 to 8. The temperature is from 10 to 35 for a silver halide emulsion containing silver halide in an organic solvent.
C is preferable, and more preferably 17 to 27C.
Further, in a silver halide emulsion dispersed in an aqueous gelatin solution, the temperature is preferably from 30 to 65 ° C, more preferably from 40 to 65 ° C.
５５55 ° C.

Two or more chalcogen sensitizers of the present invention may be used, or a known chemical sensitizer may be used in addition to the chalcogen sensitizer of the present invention.

The compounds represented by formulas (I-1) and (I-2) can be synthesized by a usual method well known to those skilled in the art.

The following formulas (I-1) and (I-2)
Shows typical specific examples of chalcogen sensitizers represented by
It is not limited to this.

[0090]

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[0091]

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[0092]

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[0093]

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Next, the infrared dye used in the present invention will be described. The infrared dye preferably used in the present invention,
Squarylium dyes having a thiopyrylium nucleus (herein referred to as thiopyrylium squarylium dyes) and squarylium dyes having a pyrylium nucleus (herein referred to as pyrylium squarylium dyes), and thiopyrylium croconium analogous to squarylium dyes Dye or pyrylium croconium dye.

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

The squarylium dye used in the present invention will be illustrated below, but the present invention is not limited to these.

[0097]

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[0098]

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[0099]

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These squarylium dyes can be synthesized by the method described in Japanese Patent Application No. 10-309493.

When these dyes are added to the photothermographic layer, they are generally dissolved in a solvent and added as a solution. However, these dyes are dispersed on fine particles by a so-called solid dispersion method. You can do it.

The photothermographic material of the present invention contains a reducing agent. Examples of suitable reducing agents are described in US Pat.
0,448, 3,773,512, 3,59
No. 3,863, and RD17029 and 29963, and include the following.

Aminohydroxycycloalkenone compounds (such as 2-hydroxypiperidino-2-cyclohexenone); amino reductone esters (such as piperidinohexose reductone monoacetate) as precursors of reducing agents; N-hydroxyurea Derivatives (such as Np-methylphenyl-N-hydroxyurea); hydrazones of aldehydes or ketones (such as anthracenaldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (hydroquinone, t -Butyl-hydroquinone, i-propylhydroquinone, methylsulfonylhydroquinone and the like); sulfhydroxamic acids (such as benzenesulfhydroxamic acid); and sulfonamidoanilines (4- (N-
2-tetrazolylthiohydroquinones (such as 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (1,2,3,4-tetrahydroquinoxaline) Amidoxins; azines (such as a combination of an aliphatic carboxylic acid arylhydrazide and ascorbic acid); a combination of polyhydroxybenzene and hydroxylamine; reductone or hydrazine; hydroxanoic acids; a combination of azines and sulfonamidophenols Α-cyanophenylacetic acid derivative; bis-β
A combination of -naphthol and a 1,3-dihydroxybenzene derivative; 5-pyrazolones; a sulfonamide phenol reducing agent; 2-phenylindane-1,3-dione and the like; chroman; 1,4-dihydropyridines (2,6-dimethoxy) -3,5-dicarbethoxy-1,4-dihydropyridine and the like; bisphenols (bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, 2,
2-bis (4-hydroxy-3-methylphenyl) propane, 4,5-ethylidene-bis (2-t-butyl-6)
-Methyl) phenol, etc., UV-sensitive ascorbic acid derivatives and 3-pyrazolidones.

Of these, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).

[0105]

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In the formula, R ₁₁ is a hydrogen atom or a group having 1 to 1 carbon atoms.
10 alkyl groups (i-propyl, butyl, 2,4,4
-Trimethylpentyl, etc.), and R ₁₂ and R ₁₃ are each an alkyl group having 1 to 5 carbon atoms (methyl, ethyl,
t-butyl etc.).

Specific examples of the compound represented by formula (A) are shown below. However, the present invention is not limited to these.

[0108]

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[0109]

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The amount of the reducing agent including the compound represented by the above general formula (A) is preferably 1 to 1 per mol of silver.
× 10 ^-2 to 10 mol, particularly preferably 1 × 10 ^-2 to 1.
5 moles.

Binders suitable for the photothermographic material of the present invention are transparent or translucent and generally colorless, and include natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as gelatin, gum arabic and polyvinyl. Alcohol, hydroxyethylcellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethylmethacrylic acid, polyvinyl chloride, polymethacrylic acid, styrene-maleic anhydride copolymer,
Styrene-acrylonitrile copolymer, styrene-butadiene copolymer, polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), polyester, polyurethane, phenoxy resin, polyvinylidene chloride, polyepoxide, polycarbonate, polyvinyl acetate, cellulose ester And polyamides. The binder may be hydrophilic or non-hydrophilic.

In order to protect the surface of the light-sensitive material and prevent abrasion, a non-light-sensitive layer may be provided outside the light-sensitive layer. The binder used for these non-photosensitive layers may be the same as or different from the binder used for the photosensitive layers.

In order to increase the speed of thermal development, in the present invention, the amount of binder in the photosensitive layer is 1.5 to 10 g / m 2.
It is preferably ² . More preferably, 1.7 to 8 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.

The photothermographic material preferably contains an additive (hereinafter referred to as a color tone agent) called a color tone agent, a color tone imparting agent or an activator toner.

The color toning agent has a function of participating in the oxidation-reduction reaction between the organic silver salt and the reducing agent to make the resulting silver image dark, particularly black. Examples of suitable toning agents are disclosed in RD 17029 and include the following.

Imides (such as phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-
Naphthalimides (such as N-hydroxy-1,8-naphthalimide); cobalt complexes (such as hexamine trifluoroacetate of cobalt); and mercaptans (such as 3-mercapto-1,2,4-).
N- (aminomethyl) aryldicarboximides (such as N- (dimethylaminomethyl) phthalimide); combinations of blocked pyrazoles, isothiuronium derivatives and certain photobleaches (N,
N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzo Merocyanine dye (3-ethyl-5-((3-ethyl-2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2,4) -Oxazolidinedione, etc.);
Phthalazinone, phthalazinone derivatives or metal salts of these derivatives (4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3-dihydro-1,4-phthalazine Dione); a combination of phthalazinone and a sulfinic acid derivative (6
-Chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate; a combination of phthalazine + phthalic acid; phthalazine (including an adduct of phthalazine) with maleic anhydride and phthalic acid , 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivatives and anhydrides thereof (phthalic acid,
A combination with at least one compound selected from the group consisting of 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; quinazolinediones, benzoxazine, naloxazine derivatives; benzoxazine-
2,4-diones (1,3-benzoxazine-2,4
-Dione, etc.); pyrimidines and asymmetric -triazines (2,4-dihydroxypyrimidine etc.), and tetraazapentalene derivatives (3,6-dimercapto-1,4-
Diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene and the like).

Preferred toning agents are phthalazone or phthalazine. 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 damage to the image after thermal development. It is preferable that the content is 0.5 to 30% by mass relative to all binders on the photosensitive layer side.

When a non-light-sensitive layer is provided on the opposite side of the light-sensitive layer with the support interposed therebetween, it is preferable that at least one layer on the non-light-sensitive layer side contains a matting agent. For prevention, it is preferable to provide a matting agent on the surface of the photosensitive material, and the matting agent is contained in a mass ratio of 0.5 to 40% with respect to all binders in the layer on the side opposite to the photosensitive layer side. preferable.

The material of the matting agent used may be either an organic substance or an inorganic substance. For example, as inorganic materials, silica described in Swiss Patent No. 330,158 and the like, French Patent 1,
No. 296,995, glass powder described in British Patent 1,1
No. 73,181 or the like, alkaline earth metals or carbonates such as cadmium and zinc can be used as a matting agent. As organic substances, US Pat. No. 2,322,03
7, starch derivatives described in Belgian Patent No. 625,451 and British Patent No. 981,198, etc.
Polyvinyl alcohol described in JP-B-44-3643, polystyrene or polymethacrylate described in Swiss Patent No. 330,158, U.S. Pat.
Organic matting agents such as polyacrylonitrile described in US Pat. No. 257 and the like and polycarbonate described in US Pat. No. 3,022,169 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. The variation coefficient of the particle size distribution is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.
% Or less.

The variation coefficient of the particle size distribution is a value represented by the following equation. (Standard deviation of particle size / average value of particle size) × 100 The matting agent can be contained in any constituent layer, but is preferably a constituent layer other than the photosensitive layer, more preferably from the viewpoint of the support. The outermost layer. The method for adding the matting agent may be a method in which the matting agent is dispersed in a coating solution in advance, or a method in which the matting agent is sprayed after the coating solution is applied and before the drying is completed.
When a plurality of types of matting agents are added, both methods may be used in combination.

Examples of the compound which can be used as a crosslinking agent in the present invention include a silane compound represented by the general formula (1) or (2) disclosed in Japanese Patent Application No. 2000-77904.

The heat-developable photosensitive material is described in JP-A-63-159.
No. 841, No. 60-140335, No. 63-2314
No. 37, No. 63-259,651 and No. 63-30424
No. 2, 63-15245, U.S. Pat. No. 4,639,4
No. 14, 4,740,455, 4,741,96
No. 6, No. 4, 751, 175, No. 4, 835, 096
Sensitizing dyes described in Nos. 1 and 2 can be used. Useful sensitizing dyes are described, for example, in RD17643, Section IV-A (Jan.
Feb. 23) or in the literature cited.

In particular, sensitizing dyes having spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, Japanese Patent Application Laid-Open Nos. 60-162247 and 2-4863 discloses an argon ion laser light source.
5, US Patent No. 2,161,331, West German Patent 93
Simple merocyanines described in JP-A-6,071 and JP-A-5-11389; for helium-neon laser light sources, JP-A-50-62425 and JP-A-54-1872.
No. 6, No. 59-102229, merocyanines described in JP-A-7-287338; JP-B-48-42172 for LED light sources and infrared semiconductor laser light sources; Id 51-9609
No. 55-39818, JP-A-62-284343.
Thiacarbocyanines described in JP-A-2-105135; tricarbocyanines described in JP-A-59-19032 and JP-A-60-80841 for infrared semiconductor laser light sources; JP-A-59-1922
No. 42, the general formula (IIIa) of JP-A-3-67242,
Dicarbocyanines containing a 4-quinoline nucleus described in (IIIb) are advantageously selected. Further, the wavelength of the infrared laser light source is 750 nm or more, more preferably 800 nm.
In the case where the wavelength is not less than nm, Japanese Patent Laid-Open Nos.
No. 1432, Tokuhei 6-52387, No. 3-1093
No. 1, U.S. Pat. No. 5,441,866, JP-A-7-13
A sensitizing dye described in, for example, No. 295 is preferably used.

These sensitizing dyes may be used alone.
Combinations of sensitizing dyes are often used, especially for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization.

The sensitizing dye may be added at any time after the preparation of the silver halide. For example, the sensitizing dye may be added to a solvent or dispersed in fine particles in a so-called solid dispersion state.
It can be added to a photosensitive emulsion containing silver halide grains or silver halide grains / organic silver salt grains. Also, like the heteroatom-containing compound having an adsorptive property to the silver halide grains, the chemical sensitization can be performed after adding and adsorbing the silver halide grains prior to the chemical sensitization. Thereby, the dispersion of the chemical sensitization center nucleus can be prevented, and high sensitivity and low fog can be achieved.

A mercapto compound, a disulfide compound, and a thione compound can be contained in order to suppress or accelerate development to control development, to improve spectral sensitization efficiency, to improve storage stability before and after development, and the like. .

When a mercapto compound is used in the present invention, it may be of any structure,
Those represented by -SS-Ar are preferred. Where M
Is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring or a condensed aromatic ring having at least one nitrogen, sulfur, oxygen, selenium or tellurium atom. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole,
Benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine, pyrazine,
Pyridine, purine, quinoline or quinazolinone.
The heteroaromatic ring includes halogen (bromine and chlorine), hydroxyl, amino, carboxyl, alkyl (having one or more carbon atoms, preferably 1-4 carbon atoms) and alkoxy (having one or more carbon atoms). (Preferably having 1 to 4 carbon atoms). Examples of the mercapto-substituted heteroaromatic compound 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, but are not limited to, 2-mercapto-4-phenyloxazole.

In the present invention, in addition to the above supersensitizers, compounds represented by the general formula (1) disclosed in Japanese Patent Application No. 2000-70296 can be used as supersensitizers.

The supersensitizer is contained in the emulsion layer containing the organic silver salt and the silver halide grains in an amount of 0.001 to 1 mol per mol of silver.
It is preferable to use it in the range of 1.0 mol. Particularly preferably, it is 0.01 to 0.5 mol per mol of silver.

The photothermographic material of the present invention has at least one photosensitive layer on a support. Although only a photosensitive layer may be formed on the support, at least one photosensitive layer may be formed on the photosensitive layer.
Preferably, a non-photosensitive layer is formed. In order to control the amount or wavelength distribution of light passing through the photosensitive layer, a filter dye layer on the same side as the photosensitive layer and / or an antihalation dye layer on the opposite side, a so-called backing layer may be formed, The photosensitive layer may contain a dye or a pigment. As the dye to be used, any compound may be used as long as it has a desired absorption in a desired wavelength range.
Nos. 9-6481, 59-182436, U.S. Pat. Nos. 4,271,263, 4,594,312, European Patent Publications 533,008, 652,473, JP-A-2-216140, No. 4-348339, 7-
Compounds described in, for example, 191432 and 7-301890 are preferably used.

These non-photosensitive layers preferably contain the binder and the matting agent described above, and may further contain a polysiloxane compound, a slipping agent such as wax and liquid paraffin.

The light-sensitive layer may be composed of a plurality of layers, and the sensitivity may be a high-sensitive layer / low-sensitive layer or a low-sensitive layer / high-sensitive layer for adjusting the gradation.

Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other constituent layers. In the photothermographic material, in addition to the above, a surfactant, an antioxidant,
Stabilizers, plasticizers, ultraviolet absorbers, coating aids, and the like may be used. As these additives and the other additives described above, compounds described in RD17029 (June 1978, pages 9 to 15) can be preferably used.

[0136] Preferred total silver photothermographic material of the present invention is 0.5~2.4g / m ^2, more preferably from 1.0 to 2.2 g / m ^2. The total amount of silver is determined according to the purpose of use of the light-sensitive material, conditions, and the like.By adjusting the total silver amount in the above range, it is possible to obtain a photothermographic material having good performance such as sensitivity, fog, and storage performance. I can do it.

It is preferable that all coating solutions used for coating the photothermographic material are filtered before coating. In the filtration, the absolute or quasi-absolute filtration accuracy is 5 to 50 μm
Is preferably passed through at least once.

In the production of a photothermographic material by coating, bubbles in the coating solution may cause poor coating such as foam streaks and pinholes. Centrifugal separation, filtration, deaeration under reduced pressure, deaeration by casting a liquid into a thin film, efficiency of separation Air bubbles in the coating solution may be removed by means, or any or all of the combinations.

The coating of the photothermographic material includes coating of each layer,
A successive multilayer coating method in which drying is repeated is mentioned, and roll coating methods such as reverse roll coating and gravure roll coating, blade coating, wire bar coating, and die coating are used. or,
Using multiple coaters, apply the next layer before drying the already applied layer and simultaneously dry multiple layers, slide coating, curtain coating or an extrusion die coater with multiple slits, And a simultaneous multi-layer coating method in which the coating liquids are laminated and applied. Among them, the latter is more preferable in that the occurrence of coating failure due to foreign matter brought in from the outside can be prevented. Furthermore, when using the simultaneous multilayer coating method, in order to prevent mixing between the layers, the viscosity at the time of application of the coating liquid of the uppermost layer is 0.1 Pa.s or more, and the viscosity at the time of application of the coating liquid of another layer is Preferably, the viscosity is 0.03 Pa · s or more. or,
When the solids dissolved in the coating liquid of each layer are laminated in a liquid state with the adjacent layer, if it is hardly soluble or insoluble in the organic solvent of the adjacent layer, it precipitates at the boundary surface and causes disturbance or turbidity of the coating film. Therefore, it is preferable that the organic solvent most contained in the coating liquid of each layer is of the same type (the content of the organic solvent commonly contained in each coating liquid in each liquid is larger than that of the other organic solvents).

After the multi-layer coating, it is preferable to dry as soon as possible, and it is desirable to reach the drying step within 10 seconds in order to avoid inter-layer mixing due to flow, diffusion, density difference and the like. As a drying method, a hot air drying method, an infrared drying method, or the like is used, and a hot air drying method is particularly preferable. The drying temperature at that time is preferably 30 to 100 ° C.

The photothermographic material may be cut into a desired size immediately after coating and drying, and then wrapped, or may be wound into a roll and temporarily stored before cutting and wrapping. The winding method is not particularly limited, but winding by tension control is generally used.

The support used for the photothermographic material is made of a plastic film (polyethylene terephthalate, polycarbonate, or the like) in order to prevent deformation of the image after development processing.
Polyimide, nylon, cellulose triacetate, polyethylene naphthalate, etc.).

Among the above-mentioned preferred supports, plastics (S) containing polyethylene terephthalate (PET) and a styrene polymer having a syndiotactic structure are preferable.
PS). The thickness of the support is 5
It is about 0 to 300 μm, preferably 70 to 180 μm. Alternatively, a heat-treated plastic support may be used. The plastics to be employed include the above-mentioned plastics.

The heat treatment of the support means that after forming the support and before coating the photosensitive layer, the glass transition point of the support is 30 ° C. or more, preferably 35 ° C. or more, more preferably Is preferably heated at a temperature higher than 40 ° C.

Next, the plastic used in the present invention will be described. PET is a polyester in which the components of the polyester are all composed of polyethylene terephthalate. In addition to polyethylene terephthalate, terephthalic acid, naphthalene-2,6-dicarboxylic acid, isophthalic acid, butylene dicarboxylic acid, 5-sodium sulfoisophthalic acid, A polyester containing a modified polyester component of adipic acid or the like and a glycol component such as ethylene glycol, propylene glycol, butanediol, cyclohexanedimethanol or the like in an amount of 10 mol% or less of the entire polyester may be used.

SPS is a polystyrene having steric regularity, unlike ordinary polystyrene (atactic polystyrene). The regular stereoregular structure part of the SPS is called a racemo chain, and it is preferable that there be more regular parts such as two, three, five or more. In the present invention, the racemo chain is 85 in two chains
% Or more, preferably 75% or more for 3 chains, 50% or more for 5 chains, and 30% or more for more chains. SP
The polymerization of S can be carried out according to the method described in JP-A-3-131843.

Known methods can be used for the film forming method and the undercoating manufacturing method of the support.
No. 50094, paragraphs [0030] to [0070].

Exposure of the photothermographic material was performed using an argon ion laser (488 nm) and a He-Ne laser (633).
nm), a red semiconductor laser (670 nm), an infrared semiconductor laser (780 nm, 820 nm) and the like are preferably used.
An infrared semiconductor laser is more preferably used from the viewpoint that the photosensitive material can be made transparent.

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,
"Never substantially perpendicular" means the angle that is most perpendicular during laser scanning, preferably 55-88.
Degrees, more preferably 60-86 degrees, even more preferably 65 degrees.
~ 84 degrees, most preferably 70-82 degrees.

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. still,
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 due to reflected light such as the occurrence of interference fringe-like unevenness.

The exposure in the present invention is also preferably performed using a laser scanning exposure machine that emits a scanning laser beam that is a vertical multi. 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. To achieve vertical multiplication, 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. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

The photothermographic material is stable at normal temperature, but is developed by heating to high temperature after exposure. The heating temperature is preferably from 80 to 200 ° C., more preferably 100 to 200 ° C.
１５０150 ° C. If the heating temperature is lower than 80 ° C., a sufficient image density cannot be obtained in a short time. If the heating temperature is higher than 200 ° C., the binder is melted, and not only the image itself such as transfer to a roller, but also the transportability, the developing machine, etc. Also has an adverse effect.

By heating, a silver image is formed by 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, where the image is formed. This reaction process proceeds without supply of a processing liquid such as water from the outside.

[0154]

EXAMPLES The present invention will be described below with reference to examples, but embodiments of the present invention are not limited to these examples.
Unless otherwise specified, “%” in Examples is “% by mass”.
Is shown. The “mol / L concentration” is represented by “M”.

Example 1 (Preparation of photosensitive silver halide emulsion 1) A1 Phenylcarbamoyl gelatin (average molecular weight: 100,000) 88.3 g Compound (A) (10% methanol solution) 10 ml Potassium bromide 0.32 g 5429 ml with water B1 0.67M silver nitrate aqueous solution 2635ml C1 Potassium bromide 51.55g Potassium iodide 1.47g Finish with water 660ml D1 Potassium bromide 154.9g Potassium iodide 4.41g Iridium chloride (1% solution) 0.93ml E1 0.4 M aqueous potassium bromide solution The following silver potential control amount F1 56% acetic acid aqueous solution 16.0 ml G1 1.72 g of anhydrous sodium carbonate Finished to 151 ml with water Compound (A): HO (CH ₂ CH ₂ O) _n [CH ( CH ₃ )
CH ₂ O] ₁₇ (CH ₂ CH ₂ O) _m H (m + n = 5 to 7) The solution (A1) was added to the solution (A1) using a mixing stirrer shown in JP-B-58-58288 and JP-B-58-58289. B
The 1/4 amount of 1) and the whole amount of the solution (C1) were subjected to pAg at 45 ° C.
While controlling to 8.09 (using E1), the mixture was added by a simultaneous mixing method in 4 minutes and 45 seconds to form nuclei.

After a lapse of 7 minutes, the remainder of the solution (B1) and the entire amount of the solution (D1) were added over 14 minutes and 15 seconds by a double jet method while controlling the temperature at 45 ° C. and the pAg at 8.09. During the mixing, the pH of the reaction solution was 5.6.

After stirring for 5 minutes, the temperature was lowered to 40 ° C., and the whole amount of the solution (F1) was added to precipitate a silver halide emulsion. The supernatant was removed except for 2000 ml of the sedimented portion, 10 L of water was added, and after stirring, the silver halide was sedimented again. The supernatant was removed except for the sedimented portion of 1500 ml, and 10 L of water was further added. After stirring, the silver halide was sedimented. After removing the supernatant liquid leaving 1500 ml of the sedimented portion, the solution (G1) was added, the temperature was raised to 60 ° C., and the mixture was further stirred for 120 minutes. Finally, the pH was adjusted to 5.8, and water was added so as to be 1161 g per mol of silver.

This emulsion had an average grain size of 0.058 μm.
m, coefficient of variation of particle size 12%, [100] face ratio 9
It was 2% cubic silver iodobromide grains.

(Preparation of photosensitive silver halide emulsion 2) A photosensitive silver halide emulsion 2 was obtained in the same manner as in the photosensitive silver halide emulsion 1 except that the liquid temperature was 35 ° C.

This emulsion had an average grain size of 0.045 μm.
m, coefficient of variation of particle size 11%, [100] face ratio 9
It was 3% cubic silver iodobromide grains.

(Preparation of photosensitive silver halide emulsion 3) Photosensitive silver halide emulsion 3 was obtained in the same manner as photosensitive silver halide emulsion 1 except that the liquid temperature was 25 ° C.

This emulsion has an average grain size of 0.040 μm.
m, coefficient of variation of particle size 12%, [100] face ratio 9
It was 3% cubic silver iodobromide grains.

(Preparation of Photosensitive Silver Halide Emulsion 4) Photosensitive silver halide emulsion 2 was prepared in the same manner as in preparation of photosensitive silver halide emulsion 2, except that the gelatin of the solution (A1) in the mixing step was changed to phenylcarbamoyl gelatin having an average molecular weight of 25,000. Similarly to photosensitive silver halide emulsion 2, photosensitive silver halide emulsion 4
Was prepared.

This emulsion had an average grain size of 0.040 μm.
m, coefficient of variation of particle size 12%, [100] face ratio 9
It was 2% cubic silver iodobromide grains.

(Preparation of photosensitive silver halide emulsion 5) A photosensitive silver halide emulsion 5 was obtained in the same manner as the photosensitive silver halide emulsion 4 except that the liquid temperature was 25 ° C.

This emulsion had an average grain size of 0.035 μm.
m, coefficient of variation of particle size 12%, [100] face ratio 9
It was 2% cubic silver iodobromide grains.

(Preparation of photosensitive silver halide emulsion 6) A photosensitive silver halide emulsion 6 was obtained in the same manner as the photosensitive silver halide emulsion 4 except that the liquid temperature was set at 17 ° C.

This emulsion had an average grain size of 0.030 μm.
m, coefficient of variation of particle size 11%, [100] face ratio 9
It was 3% cubic silver iodobromide grains.

(Preparation of Powdered Organic Silver Salt 1) In 4720 ml of pure water, 130.8 g of behenic acid and 67.7 g of arachidic acid were added.
g, 43.6 g of stearic acid and 2.3 g of palmitic acid were dissolved at 80 ° C. Next, 540.2 ml of a 1.5 M aqueous sodium hydroxide solution was added, 6.9 ml of concentrated nitric acid was added, and the mixture was cooled to 55 ° C. to obtain a fatty acid sodium solution.

The temperature of the fatty acid sodium solution was 55 ° C.
, 45.3 g of the above-mentioned photosensitive silver halide emulsion 1 and 450 ml of pure water were added thereto, followed by stirring for 5 minutes.

Next, 702.6 ml of a 1 M silver nitrate solution was added over 2 minutes and stirred for 10 minutes to obtain an organic silver salt dispersion. Thereafter, the obtained organic silver salt dispersion was transferred to a water washing container, deionized water was added thereto, and the mixture was stirred and allowed to stand. Then, the organic silver salt dispersion was floated and separated to remove lower water-soluble salts.
After that, washing with deionized water and draining are repeated until the conductivity of the waste water becomes 2 μS / cm, and after performing centrifugal dehydration, drying is performed at 40 ° C. with a hot-air circulation dryer until there is no loss in mass. Powdered organic silver salt 1 was obtained.

(Preparation of Powdered Organic Silver Salts 2 to 6) In the preparation of the powdered organic silver salt 1, except that the photosensitive silver halide emulsion 1 was changed to the photosensitive silver halide emulsions 2 to 6, respectively. Powdered organic silver salts 2 to 6 were prepared in the same manner as in Salt 1.

(Preparation of Preliminary Dispersion) Polyvinyl butyral powder (manufactured by Monsanto: Butvar B-7)
9) 14.57 g of methyl ethyl ketone (MEK) 14
The resulting dispersion was dissolved in 57 g, and 1,500 g of a powdered organic silver salt was gradually added thereto while stirring with a dissolver DISPERMAT CA-40M manufactured by VMA-GETZMANN, and sufficiently mixed to prepare a preliminary dispersion liquid 1.

With respect to powdered organic silver salts 2 to 6, preliminary dispersions 2 to 6 were prepared in the same manner.

(Preparation of photosensitive emulsion dispersion) Preliminary dispersion 1
Is filled with 0.5% zirconia beads (Toray Co., Ltd .: Treceram) so that the residence time in the mill is 10 minutes using a pump.
ISPERMAT SL-C12EX type (VMA-GE
TZMANN Co., Ltd.) and dispersed at a mill peripheral speed of 13 m / s to prepare a photosensitive emulsion dispersion 1.

With respect to Preliminary Dispersions 2 to 6, Photosensitive Emulsion Dispersions 2 to 6 were prepared in the same manner.

(Preparation of stabilizer liquid) 1.0 g of stabilizer 1,
0.31 g of potassium acetate was dissolved in 4.97 g of methanol to prepare a stabilizer solution.

(Preparation of infrared sensitizing dye solution) 19.2 mg of infrared sensitizing dye 1, 1.488 g of 2-chloro-benzoic acid, 2.779 g of stabilizer 2, and 365 mg of 5-methyl-2 31.3 ml of mercaptobenzimidazole
Was dissolved in MEK in a dark place to prepare an infrared sensitizing dye solution.

(Preparation of Additive Solution a) 27.98 g of a reducing agent (Exemplary A-3), 1.54 g of 4-methylphthalic acid,
0.48 g of the infrared dye 1 was dissolved in 110 g of MEK to prepare an additive liquid a.

(Preparation of Additive Liquid b) 3.56 g of the antifoggant 2, 3.43 g of phthalazine were dissolved in 40.9 g of MEK to prepare an additive liquid b.

(Preparation of Coating Solution for Photosensitive Layer) Under an inert gas atmosphere (nitrogen: 97%), 50 g of the above-mentioned photosensitive emulsion dispersion liquid 1 and 15.11 g of MEK were kept at the temperature shown in Table 1 while stirring (step). 1), 1000 μl of a chemical sensitizer (0.5% methanol solution) shown in Table 1 was added, and 30
After one minute, antifoggant 1 (10% methanol solution) 390
μl was added and stirred for 1 hour. In addition, calcium bromide (1
After adding 494 μl of a 0% methanol solution and stirring for 20 minutes, 167 ml of a stabilizer solution was added, and the mixture was stirred at the temperature shown in Table 1 (step 2) for 10 minutes, and then 1.32 g of the infrared sensitization was performed. The dye solution was added and stirred for 1 hour. Thereafter, the temperature was lowered to 13 ° C., and the mixture was further stirred for 30 minutes. 1
While keeping the temperature at 3 ° C., polyvinyl butyral (Butv
ar B-79: supra) 13.31 g was added and stirred for 30 minutes, and then 1.084 g of tetrachlorophthalic acid (9.4% MEK solution) was added and stirred for 15 minutes. While continuing stirring, 12.43 g of the additive solution a, 1.6 ml
Desmodur N3300 (aliphatic isocyanate manufactured by Mobay Co., Ltd.) 10% MEK solution, 4.27 g of an additive solution b were sequentially added and stirred to obtain a photosensitive layer coating solution.

With respect to photosensitive emulsion dispersions 2 to 6, photosensitive layer coating solutions 2 to 6 were obtained in the same manner.

The antifoggant 1 and calcium bromide react with an organic silver salt serving as a halide ion source to form substantially non-photosensitive silver halide grains. The molar ratio of the non-photosensitive silver halide to the photosensitive silver halide is 2.3.

The structures of the additives used in each of the above preparations are shown below.

[0185]

Embedded image

(Preparation of Matting Agent Dispersion) Cellulose acetate butyrate (Eastman Chemical)
7.5 g of MEB42.5
g of calcium carbonate (Specia)
manufactured by lite Minerals: Super-Pfl
ex200), and dispersed by a dissolver-type homogenizer at 8000 rpm for 30 minutes to prepare a matting agent dispersion.

(Preparation of Surface Protective Layer Coating Solution) MEK865
While stirring g, 96 g of cellulose acetate butyrate (CAB171-15: supra), polymethyl methacrylic acid (Parome A-21, manufactured by Rohm & Haas).
4.5 g, vinyl sulfone compound (HD-1) 1.5
g of benzotriazole and 1.0 g of a fluorine-based activator (Surflon KH40, manufactured by Asahi Glass Co., Ltd.) were added and dissolved. Next, 30 g of a matting agent dispersion was added and stirred,
A coating solution for the surface protective layer was prepared.

(Coating of Photothermographic Material Sample) The viscosities of the photosensitive layer coating solution and the surface protective layer coating solution were adjusted to 0.228 Pa · s and 0.184, respectively, by adjusting the amount of the solvent.
After filtering through a filter having a quasi-absolute filtration accuracy of 20 μm, the mixture was discharged from a slit of an extrusion die coater, laminated, and coated simultaneously on a support. After 8 seconds, the drying temperature is 75 ° C and the dew point temperature is 10
After drying with hot air of 5 ℃ for 5 minutes, ambient temperature and humidity 23 ℃ ・ 5
A photothermographic material sample 1 was prepared by winding the film in a roll at 0% RH (relative humidity) and a tension of 196 N / m.

The coated silver amount of the photosensitive layer of the obtained photosensitive material
9 g / m ² and the surface protective layer had a dry thickness of 2.5 μm.

(Performance Evaluation) The characteristics of each sample were determined as follows.

<< Sensitometry >> Each coated sample was 3.5 c
After cutting to mx 15 cm and exposing with a laser sensitometer equipped with an 810 nm diode, the photographic material was
After processing (thermal development) for 5 seconds, the obtained image was evaluated with a densitometer. _Dmin and sensitivity (the reciprocal of the ratio of the exposure amount giving a density higher than _Dmin by 1.0) were measured. The relative sensitivity was shown with the sensitivity of 1 as 100.

<< Image preservation >> Two samples subjected to the same processing as in the sensitometry evaluation were subjected to the test at 25 ° C. and 55% RH.
For 7 days, and the other sheet was exposed to natural light at 25 ° C. and 55% RH for 7 days, and then the density of the fogged portion was measured.

The image storability was evaluated by (increase in fog = fog when exposed to natural light-fog when preserved from light).

<< Raw Storage >> After storing for 10 days under the following conditions A and B, exposure and development were performed under the above conditions, and the obtained images were evaluated by a densitometer. Condition A
Difference between D _min at D and D _{min under} condition B (D _min BD −D _min A)
Was determined as the preservability (raw preservability) of the undeveloped photosensitive material.

Condition A 25 ° C./55% RH Condition B 40 ° C./80% RH The results are shown in Table 1.

[0196]

[Table 1]

Example 2 In the preparation of the photosensitive layer coating solution of Example 1, the antifoggant 1 and calcium bromide were changed to the amounts shown in Table 2 and the samples were prepared in the same manner as in Example 1 under the conditions shown in Table 2. It was fabricated and evaluated similarly. Table 2 shows the results.

[0198]

[Table 2]

Example 3 In the preparation of the photosensitive layer coating solution of Example 1, the compounds shown in Table 3 were added in place of the antifoggant 1 and calcium bromide, and the same conditions as in Example 1 were used under the conditions shown in Table 3. A sample was prepared and evaluated in the same manner. Table 3 shows the results.

[0200]

[Table 3]

[0201]

Embedded image

Example 4 In the preparation of the photosensitive silver halide emulsion of Example 1, the iridium chloride of the solution (D1) in the mixing step was changed to the compounds shown in Table 4 and the conditions of Example 1 were changed. A sample was prepared in the same manner and evaluated in the same manner. Table 4 shows the results.

[0203]

[Table 4]

Example 5 A part of the photosensitive material produced as described above was used for
The photosensitive material was exposed to light by laser scanning from the emulsion side with an exposure machine using a semiconductor laser of m as an exposure source.
At this time, an image was formed by setting the angle between the exposure surface of the photosensitive material and the exposure laser beam to 75 degrees (an image having less unevenness and unexpectedly good sharpness and the like than when the angle was set to 90 degrees). Obtained). Table 5 shows the results.

[0205]

[Table 5]

Example 6 From the emulsion surface side of the photosensitive material prepared as described above, exposure was performed by laser scanning using an exposure machine using a semiconductor laser that had been made into a vertical multimode with a wavelength of 800 to 820 nm by high frequency superimposition. Gave. At this time, an image was formed by setting the angle between the exposure surface of the photosensitive material and the exposure laser beam to 75 degrees (an image having less unevenness and unexpectedly good sharpness and the like than when the angle was set to 90 degrees). Obtained).
Table 6 shows the results.

[0207]

[Table 6]

Example 7 A part of the photosensitive material prepared as described above (Sample No. 1,
13 and 23) were exposed in the same manner as in Example 1, and the sensitometry was evaluated by changing the temperature during development as shown in Table 7.

[0209]

[Table 7]

[0210]

According to the present invention, it is possible to provide a photothermographic material, an image recording method and an image forming method, which have high sensitivity, little fogging, and improved raw storability and silver image storability after development. .

Claims (10)

[Claims] An organic silver salt, a binder and a photosensitive material are provided on a support.
Silver halide grains, non-photosensitive silver halide grains and red
Photothermographic material having a photosensitive layer containing an external dye
The photosensitive silver halide grains are formed at a temperature of 30 ° C. or lower.
And represented by the following general formula (I-1) or (I-2)
Chemical sensitization with chalcogen sensitizer
A photothermographic material comprising: Embedded image[Wherein, Z₁, Z_TwoAnd Z_ThreeRepresents an aliphatic group and an aromatic group, respectively.
Group, heterocyclic group, -OR₁, -NR_Two(R_Three), -SR_Four, −
SeR_Five, A halogen atom or a hydrogen atom. R₁, R_Four
And R_FiveRepresents an aliphatic group, an aromatic group, a heterocyclic group, hydrogen,
Represents an atom or a cation;_TwoAnd R_ThreeAre each aliphatic
Represents a group, an aromatic group, a heterocyclic group or a hydrogen atom. or,
Z₁, Z_TwoAnd Z_ThreeOf two are joined together to form a ring
May be. Y is a sulfur atom, a selenium atom or a tellurium
Um atom. [Chemical formula 2][Wherein, Z_FourAnd Z_FiveRepresents an alkyl group and an alkenyl, respectively.
Group, aralkyl group, aryl group, heterocyclic group, -NR
₆(R₇), -OR₈Or -SR₉Represents R₆, R₇, R ₈
And R₉May be the same or different and each is an alkyl
Group, aralkyl group, aryl group or heterocyclic group. Was
But R₆And R₇Each represents a hydrogen atom or an acyl group.
May be, Z_FourAnd Z_FiveAre bonded to each other to form a ring
Good. Y is sulfur atom, selenium atom or tellurium atom
Represents a child. ] 2. The photothermographic material according to claim 1, wherein low molecular weight gelatin having an average molecular weight of 50,000 or less is used at the time of forming the photosensitive silver halide grains. 3. The heat development method according to claim 1, wherein a halide ion source is reacted with the organic silver at a temperature of 20 ° C. or lower to prepare substantially non-photosensitive silver halide grains. Photosensitive material. 4. Photosensitive silver halide grains formed using low molecular weight gelatin having an average molecular weight of 50,000 or less,
4. The molar ratio of substantially non-photosensitive silver halide grains prepared by reacting a halide ion source with organic silver at a temperature of not more than 0.degree. Photothermographic material. 5. The halide ion source is a compound represented by the following general formula (II):
The photothermographic material according to the above. General formula (II) Ar— (SO ₂ ) _n —CX ₃ [In the formula, n represents 0 or 1, X represents a halogen atom, and Ar represents an aromatic group or a heteroaromatic group. ] 6. The photosensitive silver halide grains contain at least one transition metal selected from elements of Groups 6 to 11 of the periodic table.
6. The composition according to claim 1, wherein the composition contains a species.
Item. 7. The transition metal is iron, cobalt, ruthenium,
The photothermographic material according to claim 6, wherein the photothermographic material is a metal selected from rhodium, rhenium, osmium, and iridium. 8. A laser exposure to the photothermographic material according to claim 1, wherein an angle between an exposure surface of the photothermographic material and a scanning laser beam is not substantially perpendicular. An image recording method comprising performing exposure by a machine. 9. An image recording method, wherein a scanning laser beam for recording an image on the photothermographic material according to any one of claims 1 to 7 is subjected to exposure by a laser exposure device having a vertical multi-scan. Method. 10. An image forming method, wherein the photothermographic material according to claim 1 is heated and developed at 80 to 200 ° C.