JP2003241333A - Heat-developable photosensitive material, imaging method and image recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-developable photosensitive material having high density, ensuring a small density change with age of the heat-developable photosensitive material and improved in powder falling and occurrence of unevenness in density and roller marks when processed with a heat developing apparatus and to provide an image recording method using the heat-developable photosensitive material. <P>SOLUTION: In the heat-developable photosensitive material, a binder contained in an image forming layer and a binder contained in a layer adjacent to the image forming layer contain a common monomer component (hereinafter referred to as a monomer component A), and when the ratio of the mass of the monomer component A contained in the image forming layer to the mass of the binder contained in the image forming layer is represented by M1 and the ratio of the mass of the monomer component A contained in the layer adjacent to the image forming layer to the mass of the binder contained in the layer adjacent to the image forming layer is represented by M2, the formula 0.1≤M1×M2≤0.95 is satisfied. <P>COPYRIGHT: (C)2003,JPO

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 an image recording method using the photothermographic material. In any of the latter cases, the density decrease with time is small and the fog is good, and the photothermographic material improved in the generation of dust, density unevenness and roller marks when processed by a heat development processor, and the photothermographic material The present invention relates to an image forming method and an image recording method using.

[0002]

2. Description of the Related Art Conventionally, in the fields of medical treatment and printing plate making, a waste liquid caused by a wet process of an image forming material has been a problem in terms of workability. Weight loss is strongly desired. Therefore, a photothermographic material capable of forming an image only by applying heat has been put into practical use and is rapidly spreading in the above fields.

A photothermographic material (hereinafter also simply referred to as a photothermographic material or a photothermographic material) itself has been proposed for a long time, for example, US Pat. Nos. 3,152,904 and 3,457,075. , D. Morgan
By "Dry Silver Photographic Materials (Dry Silver
r Photographic Material
l) ", or D.I. H. Kloster
Boer) “Thermal Processed Silver
er Systems ”(Imaging Processes and Materials (Imaging Pro
cesses and Materials) Nebl
8th edition, Sturge, V.E. Wallworth, A.S. Shep (S
(pp. 279, 1989).

This heat-developable material is usually processed by a heat-development processing apparatus, which is called a heat-development processing machine, for applying stable heat to the heat-development material to form an image. As described above, with the rapid spread in recent years, a large amount of this heat development processing apparatus has been supplied to the market. By the way, depending on the temperature and humidity conditions during the heat development process, there is a problem that the slipperiness between the photosensitive material and the transfer roller of the heat development processing device or the processing member changes, resulting in defective transfer and uneven density. It was There is also a problem that the density of the photothermographic material changes with time. It was found that these phenomena remarkably occur in a photothermographic material in which an image is formed by heat development after imagewise exposure with a laser beam. Further, in recent years, there has been a demand for a compact laser imager and speedy processing. For that purpose, it is essential to improve the characteristics of the photothermographic material. It is more advantageous to use the heat drum method than the horizontal transfer method for downsizing of the heat development processing apparatus, but there was a problem that powder falling, uneven density, and roller marks were likely to occur during the heat development processing. . Further, in order to obtain a sufficient density of the photothermographic material even if the rapid processing is performed, it is disclosed in JP-A-1
As described in JP-A-1-295844 and JP-A-11-352627, it is effective to use a silver halide having a small average grain size to increase the covering power and to use a contrast adjusting agent such as a hydrazine compound or a vinyl compound. Is. However, when these techniques are used, there arises a problem that the density change (printout characteristics) with time after the heat development processing becomes large, or the density unevenness at the time of heat development is deteriorated. Further, the printout characteristics can be improved by reducing the amount of the reducing agent or the coating amount of silver, but there is a problem that the image density decreases with time. Further, it is likely that the sensitizing dye once adsorbed is likely to be desorbed due to the fine graining of silver halide, possibly causing a problem that the image density decreases with time even before the processing.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a high density, either before or after heat development of a photothermographic material. Also has a small decrease in density over time and has good fogging, and a heat-developable light-sensitive material having improved generation of dust, density unevenness and roller marks when processed by a heat-development processing apparatus, and an image using the heat-developable light-sensitive material It is to provide a forming method and an image recording method.

[0006]

The above objects of the present invention have been achieved by the following constitutions.

1. On the support, organic silver, silver halide,
In a photothermographic material having an image forming layer containing a binder and a reducing agent, the binder contained in the image forming layer and the binder contained in a layer adjacent to the image forming layer have a common monomer component (hereinafter referred to as monomer component A and Described) and satisfying the above formula 1, a photothermographic material.

2. 2. The photothermographic material as described in 1 above, wherein the layer adjacent to the image forming layer is an image forming layer protective layer.

3. 3. The photothermographic material as described in 2 above, wherein the image forming layer protective layer comprises at least two layers.

4. (3) The glass transition temperature of the film forming the outermost layer of the image forming layer protective layer is 5 to 50 ° C. higher than the glass transition temperature of the film forming film of the lower image forming layer protective layer. Photothermographic material.

5. 1 wherein the reducing agent is a bisphenol derivative represented by the general formula (A)
5. The photothermographic material according to any one of 4 to 4.

6. 6. The layer on the side having an image forming layer contains at least one silver saving agent selected from vinyl compounds, hydrazine derivatives and quaternary onium salts, according to any one of 1 to 5 above. Photothermographic material.

7. Average particle size is 10nm-35nm
Wherein the silver halide is
7. The photothermographic material according to any one of 1 to 6.

8. Average particle size is 10nm-35nm
And the average grain size is 45 nm to 10 nm.
7. The photothermographic material according to any one of 1 to 6 above, which contains 0 nm silver halide.

9. 1 above, which contains a silver halide chemically sensitized by a chalcogen compound
9. The photothermographic material according to any one of to 8.

10. The photothermographic material according to any one of the 1 to 9, wherein the amount of silver contained in the image forming layer is ^{0.3g / m 2 ~1.5g / m 2} .

11. 11. When the heat-developable photosensitive material according to any one of 1 to 10 above is used in a heat-development processing apparatus using a heat drum, the conveyance speed of the heat-development section is 20 mm / sec.
An image forming method characterized by performing heat development at 200 mm / sec.

12. 11. The transfer speed of the photothermographic material according to any one of 1 to 10 from the photosensitive material supply section to the image exposure section in the heat development processing apparatus is 20 mm / sec.
An image forming method, wherein the image forming method is about 200 mm / sec.

13. 11. The conveyance speed of the photothermographic material according to any one of 1 to 10 at an image exposure unit in a heat development processing apparatus is 20 mm / sec to 200 mm / sec.
An image forming method comprising:

14. 11. An image recording, characterized in that the photothermographic material according to any one of items 1 to 10 is scanned and exposed by using a laser beam in which an angle between the exposed surface and the laser beam is not substantially perpendicular. Method.

15. 11. An image recording method, wherein the photothermographic material according to any one of 1 to 10 above is subjected to scanning exposure using longitudinal multi-laser light having an exposure wavelength which is not single.

The present invention will be described in more detail. In claim 1, 0.2 ≦ M1 × M2 ≦ 0.9 is preferable, and 0.25 ≦ M1 × M2 ≦ 0.8 is more preferable.
The amount of curing agent is included in the amount of binder.

In claim 4, the glass transition temperature of the film forming the outermost layer of the protective layer is preferably 10 to 40 ° C. higher than the glass transition temperature of the film forming the protective layer below the protective layer, and more preferably 15 ° C. ℃ -35 ℃ higher.

In claim 7, when the average grain size of silver halide is smaller than 10 nm, the image density may be lowered, or the storability of the light-irradiated image may be deteriorated. If it exceeds 35 nm, the image density may decrease. The grain size referred to here means that when the silver halide grains are cubic or octahedral so-called normal crystals,
It refers to the length of the edges of silver halide grains. Further, when the silver halide grains are tabular grains, it means the diameter when converted into a circular image having the same area as the projected area of the main surface.

In the case of other non-normal crystals, for example, spherical grains, rod-shaped grains, etc., the diameter when considering a sphere equivalent to the volume of silver halide grains is calculated as the grain size. The measurement was performed using an electron microscope, and the average particle size was obtained by averaging the measured values of 300 particle sizes.

In the seventh aspect, the average grain size of silver halide is particularly preferably 10 nm to 30 nm.

In claim 8, the average particle size is 45
By using a silver halide having a particle size of 100 nm to 100 nm in combination with a silver halide having an average particle size of 10 nm to 35 nm, it is possible to improve the image density or improve (small) the decrease in the image density over time.

Silver halide having an average grain size of 10 nm to 35 nm and an average grain size of 45 nm to 100 n
The mass ratio with the silver halide which is m is preferably 95:
5 to 50:50, and more preferably 90:10 to 6
It is 0:40.

In the eleventh aspect, the transport speed of the heat developing section using the heat developing apparatus using the heat drum is preferably 25 mm / sec to 150 mm / sec, more preferably 30 mm / sec to 100 mm / sec. is there.

In the twelfth aspect, the conveying speed from the photosensitive material supplying section to the image exposing section is preferably 25 mm / se.
c to 150 mm / sec, more preferably 30 mm / s
ec to 100 mm / sec.

In the thirteenth aspect, the conveying speed in the image exposing section is preferably 25 mm / sec to 150 mm / se.
c, more preferably 30 mm / sec to 100 mm / s
ec.

The components of the present invention will be described below. In the present invention, the organic silver salt as a silver ion supply source for silver image formation is a silver salt of an organic acid or a heteroorganic acid, particularly a long chain (having 10 to 30 carbon atoms, preferably 15 to 25 carbon atoms). ) A silver salt of an aliphatic carboxylic acid and a silver salt of a nitrogen-containing heterocyclic compound are preferable. Research Disclosure (hereinafter simply referred to as RD) in which the ligand has a total stability constant of 4.0 to 10.0 for silver ions.
Also referred to as 17029 and 29963, organic or inorganic complexes are also preferable. Examples of these suitable silver salts 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 carboxyalkyl thiourea salts, for example, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3, Silver salts such as 3-dimethylthiourea; silver salts or complexes of polymer reaction products of aldehydes and hydroxy-substituted aromatic carboxylic acids, such as aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted acids (eg, salicylic acid) , Benzoic acid, 3,5-dihydroxybenzoic acid), a silver salt or complex of a reaction product thereof; a silver salt or complex of thiones, for example, 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline- 2-thione, and 3-carboxymethyl-4-thiazoline-2
-Silver salts or complexes such as thione; imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,
Examples thereof include complexes or salts of silver with a nitrogen acid selected from 4-triazole and benztriazole; silver salts such as saccharin and 5-chlorosalicylaldoxime; silver mercaptides and the like.

Of these, particularly preferred silver salts are
Examples thereof include silver salts of long-chain (10 to 30 carbon atoms, preferably 15 to 25 carbon atoms) aliphatic carboxylic acids such as silver behenate, silver arachidate and silver stearate.

In the present invention, it is preferable that two or more kinds of organic silver salts are mixed in order to improve developability and form a silver image of high density and high contrast. For example, a mixture of two or more kinds of organic acids can be used. It is preferably prepared by mixing a silver ion solution.

The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver. The forward mixing method, the reverse mixing method, the simultaneous mixing method, and JP-A-9-12764.
The controlled double jet method described in No. 3 is preferably used. For example, by adding an alkali metal salt (for example, sodium hydroxide, potassium hydroxide, etc.) to an organic acid, an organic acid alkali metal salt soap (for example,
Sodium behenate, sodium arachidate, etc.) are prepared, and then the soap and silver nitrate are mixed by the controlled double jet method to prepare organic silver salt crystals. At that time, silver halide grains may be mixed.

The organic silver salt according to the present invention may be used in various shapes, but tabular grains are preferred. In particular, tabular organic silver salt particles having an aspect ratio of 3 or more,
In addition, in order to reduce the shape anisotropy of two substantially parallel surfaces (main planes) having the maximum area to increase the filling rate in the photosensitive layer, the flat organic film is measured from the main plane direction. Particles having an average acicular ratio of silver salt particles of 1.1 or more and less than 10.0 are preferable. A more preferable acicular ratio is 1.1 or more and less than 5.0.

In the present invention, the tabular organic silver salt particles having an aspect ratio of 3 or more means that the tabular organic silver salt particles account for 50% or more of the total number of organic silver salt particles. Further, in the organic silver salt according to the present invention, it is preferable that tabular organic silver salt particles having an aspect ratio of 3 or more account for 60% or more of the total number of organic silver salt particles, and more preferably 70% or more (number). And particularly preferably 80% or more (number).

In the present invention, the tabular grains having an aspect ratio of 3 or more are grains having a ratio of grain size to thickness and a so-called aspect ratio (abbreviated as AR) represented by the following formula of 3 or more.

AR = particle size (μm) / thickness (μm) The aspect ratio of the tabular organic silver salt particles according to the present invention is preferably 3 to 20, and more preferably 3 to 10.
Is. The reason is that if the aspect ratio is too low, the organic silver salt particles are likely to be most densely packed, and if the aspect ratio is too high, the organic silver salt particles are likely to overlap with each other, and the particles are dispersed in a sticky state. The above range is preferable because light is likely to be generated and light scattering is likely to occur, resulting in deterioration of transparency of the light-sensitive material.

In order to measure the particle size of the above-mentioned organic silver salt particles, the organic silver salt after dispersion is diluted and dispersed on a grid with a carbon support film, and a transmission electron microscope (for example, manufactured by JEOL, A photograph is taken with a 2000FX type, direct magnification of 5000 times), and the particle size is measured. When obtaining the average particle diameter, a negative image is captured as a digital image with a scanner, 300 or more particle diameters (equivalent circle diameters) are measured using an appropriate image processing software, and the average particle diameter is calculated.

The thickness of the above-mentioned organic silver salt particles is determined by a method using a TEM (transmission electron microscope) as shown below.

First, the image-forming layer coated on the support is attached to an appropriate holder with an adhesive, and the thickness of the support is adjusted to 0.1 to 0.1 with a diamond knife in a direction perpendicular to the surface of the support.
Make 0.2 μm ultrathin sections. The produced ultra-thin section was supported on a copper mesh, transferred onto a carbon film hydrophilized by glow discharge, and cooled with liquid nitrogen to -130 ° C. or below while being a transmission electron microscope (hereinafter referred to as TEM).
A bright field image is observed with a magnification of 5,000 to 40,000 times, and the image is quickly recorded on a film, an imaging plate, a CCD camera or the like. At this time, it is preferable to appropriately select a portion where the slice is not broken or loosened as the field of view to be observed.

As the carbon film, it is preferable to use an ultrathin collodion, formbar, or the like supported on an organic film. More preferably, the carbon film is formed on a rock salt substrate and the substrate is dissolved and removed. It is a film of carbon alone obtained by removing the film by an organic solvent and ion etching. The acceleration voltage of TEM is 80 to 4
00kV is preferable, particularly preferably 80 to 200k
V.

For a TEM image recorded on a suitable medium, it is preferable that one image is decomposed into at least 1024 pixels × 1024 pixels, preferably 2048 pixels × 2048 pixels or more, and image processing is performed 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 emphasis, etc. are performed as necessary. After that, a histogram is prepared and a portion corresponding to the organic silver salt particles is extracted by the binarization process.

To determine the average thickness, the thickness of the above-extracted organic silver salt particles is manually measured by 300 or more pieces with an appropriate software, and the average value is determined.

Further, the average value of the acicular ratio of the tabular organic silver salt particles can be obtained 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 and peeled from the support, and ultrasonic cleaning using the above solvent, centrifugation, and removal of the supernatant are performed. Repeat 5 times. The above steps are carried out under safelight.

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

The film on which the particles are mounted has a thickness of 3 from an angle of 30 ° with respect to the film surface by a vacuum vapor deposition device.
After obliquely depositing Pt-C of nm with an electron beam, it is preferably used for observation.

For details of the electron microscope observation technique and the sample preparation technique, "Electron Microscope Society of Japan Kanto Branch Edition / Medical / Biological Electron Microscope Observation Method" (Maruzen), "Electron Microscope Society of Japan Kanto Chapter Edition / Electronics" Microscopic biological sample preparation method "(Maruzen) can be referred to respectively.

The produced sample was subjected to an accelerating voltage of 2 kV 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 at 4 to 4 kV and the image is stored in an appropriate recording medium.

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

For images recorded on a suitable medium, it is preferable to decompose one image into at least 1024 pixels × 1024 pixels, preferably 2048 pixels × 2048 pixels or more, and perform image processing by a computer.

As a procedure of the image processing described above, first, a histogram is prepared and binarization processing is performed to extract a portion corresponding to an organic silver salt particle having an aspect ratio of 3 or more. The unavoidably agglomerated particles are cut by an appropriate algorithm or manual operation to extract the contour. Then, the maximum length (MX LNG) and the minimum width (WIDTH) of each particle are measured for at least 1000 particles, and the acicular ratio is calculated for each particle by the following formula. Here, the maximum length of a particle means 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 the distance between the parallel lines becomes minimum when two parallel lines circumscribing the particle are drawn.

Needle ratio = (MX LNG) ÷ (WIDTH) After that, the average value of the needle ratio for all the measured particles is calculated. When performing the measurement according to the above procedure, it is preferable to sufficiently perform length correction per pixel (scale correction) and two-dimensional distortion correction of the measurement system using a standard sample in advance. As a standard sample, uniform latex particles (DULP) commercially available from Dow Chemical Company in the United States are suitable, and polystyrene particles having a coefficient of variation of less than 10% for a particle size of 0.1 to 0.3 μm are suitable. Preferably, specifically a particle size of 0.2
Lots with 12 μm and standard deviation 0.0029 μm are available.

Details of the image processing technology can be referred to “Hiroshi Tanaka, Image Processing Application Technology (Industrial Research Committee)”,
The image processing program or device is not particularly limited as long as the above operations can be performed, and an example thereof is Luzex-III manufactured by Nireco.

The method for obtaining the organic silver salt particles having the above-mentioned shape is not particularly limited, but the mixed state when the organic acid alkali metal salt soap is formed and / or the mixed state when silver nitrate is added to the soap is used. It is effective to keep it good and to optimize the proportion of silver nitrate that reacts with soap.

The tabular organic silver salt particles according to the present invention are preferably predispersed with a binder, a surfactant and the like, if necessary, and then dispersed and pulverized by a media disperser or a high pressure homogenizer. For the above preliminary dispersion, a general stirrer such as an anchor type or a propeller type, a high-speed rotating centrifugal radiating stirrer (dissolver), or a high-speed rotating shearing stirrer (homomixer) can be used.

Further, as the above-mentioned media disperser, a rolling mill such as a ball mill, a planetary ball mill, a vibrating ball mill, a bead mill which is a medium stirring mill, an attritor,
It is possible to use other basket mills,
As the high-pressure homogenizer, various types such as a type that collides with a wall or a plug, a type that divides a plurality of liquids and then collides liquids at high speed, a type that allows a liquid to pass through a thin orifice, and the like can be used.

Examples of the ceramics used for the ceramic beads used at the time of dispersing the media include 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 (strontium titanate), BeAl ₂ O ₄ , Y ₃ Al ₅ O ₁₂ , Zr
O ₂ -Y ₂ O ₃ (cubic zirconia), 3BeO-Al ₂ O
₃ -6SiO ₂ (Synthesis emerald), C _{(diamond), Si 2 O-nH 2} O, ticker silicon, yttrium stabilized zirconia, zirconia toughened alumina, and the like are preferable. Yttrium-stabilized zirconia and zirconia-reinforced alumina (ceramics containing these zirconia are abbreviated as zirconia in the following) are particularly preferably used because, for example, impurities are less likely to be generated by friction with beads or a disperser during dispersion.

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

When carrying out the above-mentioned dispersion, the binder concentration is preferably 0.1 to 10% of the mass of the organic silver salt, and it is preferable that the liquid temperature does not exceed 45 ° C. from the preliminary dispersion to the main dispersion. The preferred operating conditions for the main dispersion are, for example, 29.42 mPa to 98.06 mPa when a high-pressure homogenizer is used as the dispersion means.
The number of times of operation is preferably 2 or more as a preferable operation condition. When the media disperser is used as the dispersing means, the peripheral speed is preferably 6 m / sec to 13 m / sec.

In a preferred embodiment of the photothermographic material according to the present invention, the proportion of organic silver salt particles exhibiting a projected area of less than 0.025 μm ² when the section of the material perpendicular to the support surface is observed with an electron microscope. Represents 70% or more of the total projected area of the organic silver salt particles, and the proportion of particles having a projected area of 0.2 μm ² or more is 10% of the total projected area of the organic silver salt particles.
% Or less, and an organic silver salt having a characteristic of not more than%, and a photosensitive emulsion containing a photosensitive silver halide are coated. In such a case, it is possible to obtain a state in which the organic silver salt particles are less aggregated and uniformly distributed in the photosensitive emulsion.

The conditions for producing the photosensitive emulsion having such characteristics are 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, etc. To maintain good quality, to optimize the proportion of silver nitrate that reacts with soap, to disperse and grind with a media disperser or a high-pressure homogenizer, and the amount (concentration) of binder used should be the organic silver salt. In addition to being 0.1 to 10% of the mass, the temperature from the drying to the end of the main dispersion not exceeding 45 ° C., etc., and stirring at a peripheral speed of 2.0 m / sec or more using a dissolver during liquid preparation. That is mentioned as a preferable condition.

The projected area of the organic silver salt grains having a specific projected area value as described above, the ratio of the projected area to the total projected area, and the like are the same as those described in the section for obtaining the average thickness of the tabular grains described above. , TEM (transmission electron microscope) is used to extract the portions corresponding to the organic silver salt particles.

At this time, the organic silver salt particles aggregated are regarded as one particle and treated to determine the area (AREA) of each particle. Similarly, the area of at least 1,000 particles, preferably 2,000 particles, was determined, and for each of them, A: less than 0.025 μm ² and B: 0.025 μm ²
It is classified into three groups of not less than 0.2 μm ² and C: 0.2 μm ² or more. The light-sensitive material of the present invention has a total area of the particles belonging to the group A of 70% or more of the measured total particles, and a total area of the particles belonging to the group C of the total area of the measured particles. It preferably satisfies 10% or less.

Before performing the measurement in the above procedure, the standard sample is used in advance to perform the length correction (scale correction) per pixel and the two-dimensional strain correction of the measurement system by the average value of the above-mentioned needle-like ratio. It is preferable to use the method used for the calculation.

The details of the image processing technology can be referred to “Hiroshi Tanaka, Image Processing Application Technology (Industrial Research Committee)” as described above, and the image processing program or apparatus is not particularly limited as long as the above operation can be performed. However, as an example, Luzex-III manufactured by Nireco Co., Ltd. may be mentioned as an example.

The organic silver salt particles according to the present invention are preferably monodisperse particles, and the preferable monodispersity is 1 to
It is 30%, and by using monodisperse particles in this range, a high density image can be obtained. The monodispersity here is defined by the following formula.

Monodispersity = {(standard deviation of grain size) / (average value of grain size)} × 100 The average grain size (equivalent circle diameter) of the organic silver salt described above is 0.01.
To 0.2 μm is preferable, and more preferably 0.02 to
It is 0.15 μm. The average particle size (equivalent circle diameter) means the diameter of a circle having the same area as each particle image observed by an electron microscope.

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 0.3 g or more and 1.5 g or less per 1 m ² in terms of silver amount. . Within this range, a preferable image can be obtained when it is used as a medical image. If it is less than 0.3 g per 1 m ² , the image density may decrease. If it exceeds 1.5 g per 1 m ² , fog may increase or the sensitivity may decrease when printing on a PS plate.

The silver halide (hereinafter, also referred to as photosensitive silver halide grains or silver halide grains) according to the present invention will be described. Incidentally, the silver halide according to the present invention is capable of intrinsically absorbing light as a unique property of a silver halide crystal, or absorbing visible light or infrared light by an artificial physicochemical method. In order to obtain a physicochemical change in the silver halide crystal and / or the crystal surface when the light is absorbed in any region within the light wavelength range from the ultraviolet light region to the infrared light region. It means a processed and produced silver halide crystal grain.

The silver halide grains themselves used in the present invention are described in P. Glafkides Chimie et
Physique Photographique (P
aul Montel, 1967), G.A. F. D
by Uffin Photographic Emuls
Ion Chemistry (The FocalPr
ess, 1966), V.I. L. Zelikman
Et al. Making and Coating
Photographic Emulsion (Th
e Focal Press, 1964) and the like to prepare a silver halide grain emulsion (also referred to as a silver halide emulsion). That is,
Any of an acidic method, a neutral method, an ammonia method and the like may be used, and as a method of reacting the soluble silver salt and the soluble halogen salt, any of a one-sided mixing method, a simultaneous mixing method and a combination thereof may be used. Among the above methods, the so-called controlled double jet method, in which silver halide grains are prepared while controlling the forming conditions, is preferable. 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.

Grain formation is usually divided into two stages of silver halide seed grain (nucleus) formation and grain growth, and a method of continuously performing them at one time may be used. Alternatively, nucleation (seed grain) formation and grain growth may be carried out. A method of performing the separation may be used. The controlled double jet method in which particles are formed by controlling particle forming conditions such as pAg and pH is preferable because the shape and size of particles can be controlled. For example, when performing the method of performing nucleation and grain growth separately, first, the silver salt aqueous solution and the halide aqueous solution are uniformly and rapidly mixed in the gelatin aqueous solution to form nuclei (seed particles) (nucleation step). ,
Silver halide grains are prepared by a grain growth step of growing grains while supplying an aqueous silver salt solution and an aqueous halide solution under controlled pAg, pH and the like. After particle formation,
In the desalting step, unnecessary salts and the like are removed by a known desalting method such as a noodle method, a flocculation method, an ultrafiltration method or an electrodialysis method to obtain a desired silver halide emulsion.

In the present invention, the grain size of the silver halide grains is preferably monodisperse. Here, the monodisperse means that the coefficient of variation of particle size obtained by the following formula is 3
It means 0% or less. It is preferably 20% or less, more preferably 15% or less.

Coefficient of variation of grain size% = (standard deviation of grain size / average value of grain size) × 100 The shape of silver halide grains is cubic, octahedron, tetradecahedral grain, tabular grain, spherical grain, rod-like grain. Particles, potato-like particles and the like can be mentioned, and among these, in particular, cubic, octahedral, 14
Hedron and tabular silver halide grains are preferred.

When tabular silver halide grains are used, the average aspect ratio is preferably 1.5 or more and 100 or less, more preferably 2 or more and 50 or less. These are described in U.S. Pat. Nos. 5,264,337 and 5,314,7.
No. 98, No. 5,320,958, etc., and the target tabular grain can be easily obtained. Further, grains having rounded corners of silver halide grains can also be preferably used.

The crystal habit on the outer surface of the silver halide grain is not particularly limited, but a sensitizing dye having crystal habit (plane) selectivity is used in the adsorption reaction of the sensitizing dye on the surface of the silver halide grain. In some cases, it is preferable to use silver halide grains having a relatively high proportion of crystal habit adapted to the selectivity. For example, when a sensitizing dye that selectively adsorbs on a crystal plane having a Miller index of [100] is used, the proportion of the [100] plane on the outer surface of the silver halide grain is preferably high, and this proportion is 50. % Or more, more preferably 70% or more, 8
It is particularly preferably 0% or more. The ratio of the Miller index [100] plane is [11] in the adsorption of the sensitizing dye.
T. 1 utilizing the adsorption dependence between the [1] plane and the [100] plane. T
ani, J .; Imaging Sci. , 29,165
(1985).

The silver halide grains used in the present invention are
It is preferable to use low molecular weight gelatin having an average molecular weight of 50,000 or less at the time of grain formation, and it is particularly preferable to use at the time of nucleation of silver halide grains.

In the present invention, the low molecular weight gelatin preferably has an average molecular weight of 50,000 or less, more preferably 20.
0 to 40,000, particularly preferably 5000 to 2
It is 5000. The average molecular weight of gelatin can be measured by gel filtration chromatography.

The low-molecular weight gelatin is obtained by adding a gelatin-decomposing enzyme to a commonly used aqueous gelatin solution having an average molecular weight of about 100,000 for enzymatic decomposition, or adding an acid or an alkali to heat and hydrolyze, or at atmospheric pressure or under pressure. It can be obtained by thermal decomposition by heating at 1, or decomposition by irradiation with ultrasonic waves, or by combining those methods.

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

The silver halide grains used in the present invention are
At the time of forming the particles, it is preferable to use a compound represented by the following general formula.

The general formula YO (CH ₂ CH ₂ O) _m (CH (CH ₃ ) CH ₂ O) _p (C
During H ₂ CH ₂ O) _n Y formula, Y is a hydrogen atom, -SO ₃ M, or -CO-B-C
Represents OOM, M represents a hydrogen atom, an alkali metal atom, an ammonium group or an ammonium group substituted with an alkyl group having 5 or less carbon atoms, and B represents a chain or cyclic group forming an organic dibasic acid Represents m and n are 0 to 5 respectively
Represents 0 and p represents 1 to 100.

The polyethylene oxide compound represented by the above general formula is a step of producing an aqueous gelatin solution and a step of adding a water-soluble halide and a water-soluble silver salt to the gelatin solution in producing a silver halide photographic light-sensitive material. , It has been preferably used as an antifoaming agent against remarkable foaming when the emulsion raw material is stirred or moved, such as the step of coating the emulsion on a support. It is described in JP-A-44-9497. The polyethylene oxide compound represented by the above general formula also functions as a defoaming agent during nucleation.

The compound represented by the above general formula is preferably used in an amount of 1% by mass or less, more preferably 0.01 to 0.1% by mass, based on silver.

The polyethylene oxide compound represented by the above general formula has only to be present at the time of nucleation and is preferably added in advance to the dispersion medium before nucleation, but it may be added during nucleation. However, it may be added to an aqueous silver salt solution or an aqueous halide solution used for nucleation. It is preferable to add 0.01 to 2.0% by mass to an aqueous halide solution or both aqueous solutions. The compound represented by the above general formula is preferably allowed to exist for at least 50% of the time of the nucleation step, more preferably 70%.
It is allowed to exist in the time spanning the above. The compound represented by the above general formula may be added as a powder or may be dissolved in a solvent such as methanol and added.

The temperature during nucleation is usually 5 to 60 ° C.,
The temperature is preferably 15 to 50 ° C., and even at a constant temperature, a heating pattern (for example, the temperature at the start of nucleation is 25
It is preferable that the temperature is gradually raised during the nucleation at 0 ° C. and the pattern is controlled within the above temperature range even in the case where the temperature at the end of the nucleation is 40 ° C.) or the reverse pattern.

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

The pH at the time of nucleation can be usually set in the range of 1.7 to 10, but it is preferably pH 2 to 6 because the particle size distribution of the nuclei formed is widened at the pH on the alkaline side. The pBr at the time of nucleation is usually 0.05 to 3.0, preferably 1.0 to 2.5, more preferably 1.5.
Is about 2.0.

The silver halide grains used in the present invention may be added to the image forming layer by any method, and the silver halide grains are arranged so as to be close to the reducible silver source (organic silver salt). Is preferred.

The silver halide grains used in the present invention are prepared in advance and added to a solution for preparing the organic silver salt grains in the silver halide preparing step and the organic silver salt grain preparing step. Since it can be handled separately, it is preferable in terms of production control. However, as described in British Patent No. 1,447,454, a halogen component such as a halide ion is used as an organic silver salt-forming component when preparing organic silver salt particles. By co-existing with and injecting silver ions into the co-existing material, the organic silver salt particles can be generated almost at the same time.

It is also possible to react the organic silver salt with a halogen-containing compound to prepare silver halide grains by conversion of the organic silver salt. That is, a part or part of the organic silver salt is converted into a photosensitive silver halide by allowing a silver halide-forming component to act on a solution or dispersion of an organic silver salt prepared in advance or a sheet material containing the organic silver salt. You can also

As the silver halide-forming component, there are inorganic halogen compounds, onium halides, halogenated hydrocarbons, N-halogen compounds and other halogen-containing compounds. Specific examples thereof are described in US Pat. No. 4,009, 0
No. 39, No. 3,457,075, No. 4,003.
No. 749, British Patent No. 1,498,956 and JP-A Nos. 53-27027 and 53-25420, inorganic halides such as metal halides and ammonium halides, for example, trimethyl. Onium halides such as phenylammonium bromide, cetylethyldimethylammonium bromide, trimethylbenzylammonium bromide, such as iodoform, bromoform, carbon tetrachloride, 2-bromo-2.
-Halogenated hydrocarbons such as methylpropane, N-halogen compounds such as N-bromosuccinimide, N-bromophthalimide, N-bromoacetamide, etc.
Triphenylmethyl chloride, triphenylmethyl bromide, 2
-Bromacetic acid, 2-bromoethanol, dichlorobenzophenone and the like. Thus, silver halide can also be prepared by converting a part or all of silver in the organic acid silver salt into silver halide by reacting the organic acid silver salt with a halogen ion. Further, silver halide grains produced by converting a part of these organic silver salts to separately prepared silver halide may be used together.

These silver halide grains, both separately prepared silver halide grains and silver halide grains obtained by conversion of an organic silver salt, are contained in an amount of 0.001 per mol of the organic silver salt.
It is preferable to use 1 mol to 0.7 mol, 0.03
More preferably, it is used in a mole to 0.5 mole.

The silver halide used in the present invention is originally composed of
Ions of transition metals belonging to groups 6 to 11 of the periodic table
It is preferable to contain As the above metal, W,
Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, O
s, Ir, Pt, and Au are preferable. Even one of these
You may use together 2 or more types of the same or different metal complex.
These metal ions directly convert the metal salt into silver halide.
It may be introduced, but it may also be introduced in the form of a metal complex or complex ion.
Can be introduced into silver genide. Content is 1 x 1 for 1 mol of silver
0^-91 x 10 from mole^-2A molar range is preferred, 1 × 1
0^-8~ 1 x 10 ^-FourIs more preferable. The present invention
The transition metal complex or complex ion is represented by the following general formula.
Those that can be used are preferred.

In the general formula [ML ₆ ] ^m , M is a transition metal selected from the elements of groups 6 to 11 of the periodic table, L is a ligand, and m is 0,-, 2-, 3-.
Or represents 4-. Specific examples of the ligand represented by L include halogen ion (fluoride ion, chlorine ion, bromine ion, iodine ion), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aco. Examples include ligands, nitrosyl, thionitrosyl, and the like, with preference given to ako, nitrosyl, thionitrosyl, and the like. When an aco ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

It is preferable that a compound providing an ion or a complex ion of these metals is added at the time of silver halide grain formation and incorporated into the silver halide grain. Preparation of the silver halide grain, that is, nucleation and growth. , Physical aging,
It may be added at any stage before and after the chemical sensitization, but it is preferably added at the stage of nucleation, growth and physical ripening, more preferably at the stage of nucleation and growth, particularly preferably the nucleus. Add at the stage of formation. Upon addition, it may be added dividedly over several times, or it may be added uniformly in the silver halide grains.
29603, JP-A-2-306236, 3-16.
No. 7545, No. 4-76534, No. 6-110146
No. 5,273,683 and the like, the particles may be contained by being distributed in the particles.

These metal compounds can be added after being dissolved in water or a suitable organic solvent (eg alcohols, ethers, glycols, ketones, esters, amides). The method of adding an aqueous solution of the powder of 1) or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or a silver salt aqueous solution and a halide aqueous solution. When mixed at the same time, it is added as a third aqueous solution to prepare silver halide grains by a three-liquid simultaneous mixing method, a method in which a necessary amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or a halogen There is a method of adding and dissolving another silver halide grain which is previously doped with a metal ion or a complex ion at the time of preparing silver halide. Particularly preferred is a method of adding an aqueous solution of a powder of a metal compound or an aqueous solution in which a metal compound and NaCl or KCl are dissolved together to the halide aqueous solution. When added to the surface of the particles, a necessary amount of an aqueous solution of the metal compound may be added to the reaction vessel immediately after the particles are formed, during or during physical ripening, or at the end of chemical ripening.

The photosensitive silver halide grains prepared separately can be desalted by a known desalting method such as a noodle method, a flocculation method, an ultrafiltration method or an electrodialysis method.
The photothermographic material can be used without being desalted.

The silver halide grains used in the present invention can be chemically sensitized. For example, Japanese Patent Laid-Open No. 2001-2001
According to the methods disclosed in 249428 and JP 2001-249426 A, a chemical sensitization center (chemical sensitization nucleus) is formed by using a compound having a chalcogen atom such as sulfur or a noble metal compound releasing a noble metal ion such as gold ion. Can be formed and imparted. In the present invention, it is particularly preferable to use the chemical sensitization with the compound having a chalcogen atom and the chemical sensitization with the noble metal compound in combination.

In the present invention, it is preferably chemically sensitized by the following compounds containing a chalcogen atom.

The compound containing a chalcogen atom useful as an organic sensitizer is preferably a compound having a group capable of adsorbing to silver halide and an unstable chalcogen atom site.

Examples of these organic sensitizers include JP-A-60
Organic sensitizers having various structures disclosed in JP-A-150046, JP-A-4-109240, JP-A-11-218874 and the like can be used. Among them, the chalcogen atom is a carbon atom or a phosphorus atom. It is preferably at least one kind of compound having a structure in which is bound by a double bond.

The amount of the compound containing a chalcogen atom used as an organic sensitizer varies depending on the chalcogen compound used, the silver halide grains, the reaction environment at the time of chemical sensitization, and the like. 10 ^-8 to 10
^It is preferably ^-2 mol, more preferably 10 ^-7 to 10 ^-3 mol. The chemical sensitizing environment in the present invention is not particularly limited, but in the presence of a compound capable of eliminating silver chalcogenide or silver nuclei on the photosensitive silver halide grains or reducing their size, and particularly silver nuclei. It is preferable to perform chalcogen sensitization using an organic sensitizer containing a chalcogen atom in the coexistence of an oxidant capable of oxidizing the compound. As the sensitization condition, pAg is preferably 6 to 11, and more preferably 7 The pH is preferably 10 to 10, the pH is preferably 4 to 10, more preferably 5 to 8, and the temperature is preferably 30 ° C. or lower for sensitization.

Therefore, in the photothermographic material of the present invention, an organic sensitizer containing a chalcogen atom in the coexistence of the photosensitive silver halide with an oxidizing agent capable of oxidizing the silver nucleus on the grain is used. It is preferable to use a photosensitive silver halide emulsion which has been subjected to chemical sensitization at a temperature of 30 ° C. or lower, mixed with an organic silver salt, dispersed, dehydrated and dried.

The chemical sensitization using these organic sensitizers is preferably carried out in the presence of a spectral sensitizing dye or a hetero atom-containing compound having adsorptivity for silver halide grains. By carrying out chemical sensitization in the presence of a compound having adsorptivity to silver halide, it is possible to prevent dispersion of the chemically sensitized central nucleus and to achieve high sensitivity and low fog. The spectral sensitizing dye used in the present invention will be described later, but as the hetero atom-containing compound having adsorptivity to silver halide, a nitrogen-containing heterocyclic compound described in JP-A-3-24537 is preferable. Can be mentioned. In the nitrogen-containing heterocyclic compound used in the present invention, the heterocycle is a pyrazole ring, a pyrimidine ring, a 1,2,4-triazole ring, a 1,2,3-triazole ring, a 1,3,4-
Thiadiazole ring, 1,2,3-thiadiazole ring,
1,2,4-thiadiazole ring, 1,2,5-thiadiazole ring, 1,2,3,4-tetrazole ring, pyridazine ring, 1,2,3-triazine ring, and these rings are 2 to 3
An individually bonded ring, for example, a triazolotriazole ring, a diazaindene ring, a triazaindene ring, a pentaazaindene ring and the like can be mentioned. A heterocycle in which a monocyclic heterocycle and an aromatic ring are condensed, for example, a phthalazine ring, a benzimidazole ring, an indazole ring, a benzthiazole ring and the like can also be applied.

Of these, preferred is an azaindene ring, and an azaindene compound having a hydroxyl group as a substituent, for example, hydroxytriazaindene,
Further preferred are hydroxytetraazaindene, hydroxypentaazaindene compounds and the like.

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

The addition amount of these heterocyclic compounds varies over a wide range depending on the size and composition of the silver halide grains and other conditions, but the approximate amount is approximately 1.
The amount per mol is in the range of 10 ^-6 mol to 1 mol, preferably 10 ^-4 mol to 10 ^-1 mol.

As described above, the silver halide grains according to the present invention can be subjected to noble metal sensitization using a compound that releases noble metal ions such as gold ions. For example,
As the gold sensitizer, chloroaurate and organic gold compounds can be used.

In addition to the above-mentioned sensitization method, reduction sensitization method and the like can be used. As the shell-like compound for reduction sensitization, ascorbic acid, thiourea dioxide, stannous chloride, hydrazine derivative , Borane compounds, silane compounds, polyamine compounds and the like can be used. Also, adjust the pH of the emulsion to 7
Reduction sensitization can be carried out by aging the above or keeping pAg at 8.3 or less.

The silver halide to be chemically sensitized according to the present invention may be one formed in the presence of an organic silver salt or one formed in the absence of an organic silver salt.
A mixture of both may be used.

Spectral sensitization is preferably carried out by adsorbing a spectral sensitizing dye on the photosensitive silver halide grains used in the present invention. As the spectral sensitizing dye, cyanine dye, merocyanine dye, complex cyanine dye, complex merocyanine dye, holopolar cyanine dye, styryl dye, hemicyanine dye, oxonol dye, hemioxonol dye and the like can be used. For example, JP-A-63
-159841, 60-140335, 63-
231437, 63-259651, 63-3
04242, 63-15245, U.S. Pat.
The sensitizing dyes described in 639,414, 4,740,455, 4,741,966, 4,751,175, and 4,835,096 can be used. . Useful sensitizing dyes used in the present invention are, for example, RD
17643 IV-A (December 1978, p.23) and 18431X (August, 1978, p.437). Particularly, it is preferable to use a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various laser imagers and scanner light sources. For example, JP-A Nos. 9-34078, 9-54409, and 9-
The compound described in 80679 is preferably used.

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

In the present invention, it is particularly preferable to use a sensitizing dye having a spectral sensitivity in the infrared. Infrared spectral sensitizing dyes preferably used in the present invention include, for example, US Pat. Nos. 4,536,473 and 4,51.
Infrared spectral sensitizing dyes disclosed in 5,888, 4,959,294 and the like can be mentioned.

As the infrared spectral sensitizing dye used in the present invention, a long-chain polymethine dye characterized in that a sulfinyl group is substituted on the benzene ring of the benzazole ring is particularly preferable.

The above infrared sensitizing dyes are described, for example, by F.M.Harmer, The Chemistry of H.
ETHEROCYCLIC COMPOUNDS 18th
Volume, The Cyanine Dyes and Re
Late Compounds (A. Weissbe
rger ed. Published by Interscience, Ne
w York 1964).

The infrared sensitizing dye may be added at any time after the silver halide is prepared, for example, by adding it to a solvent or in the form of fine particles dispersed in a so-called solid dispersion state. It can be added to a light-sensitive emulsion containing silver halide grains / organic silver salt grains. Further, similarly to the above-mentioned compound containing a hetero atom having adsorptivity to silver halide grains, chemical sensitization can be carried out after addition and adsorption to silver halide grains prior to chemical sensitization. It is possible to prevent the chemical sensitization central nucleus from being dispersed, and high sensitivity,
A low fog can be achieved.

In the present invention, the above-mentioned spectral sensitizing dyes may be used alone, or may be used in combination.
A combination of sensitizing dyes is often used especially for the purpose of supersensitization.

The emulsion containing silver halide grains or organic silver salt grains used in the photothermographic material of the present invention contains a sensitizing dye, a dye which does not itself have a spectral sensitizing effect or a visible light. It is also possible that the substance which is not absorbed by the dye and exhibits a supersensitizing effect is contained in the emulsion, whereby the silver halide grains may be supersensitized.

Useful sensitizing dyes, combinations of dyes exhibiting supersensitization and substances exhibiting supersensitization are RD17643 (19).
(December 1978) Page J, Item IV, page 23, Japanese Patent Publication Nos. 9-25500, 43-4933, JP-A-59-
19032, 59-192242, JP-A-5-3.
In the present invention, a heteroaromatic mercapto compound or a mercapto derivative compound represented by the following general formula is preferable as the supersensitizer in the present invention.

General Formula Ar-SM wherein M is a hydrogen atom or an alkali metal atom, and A
r is a heteroaromatic ring or a condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium, or tellurium atoms. Preferred heteroaromatic ring or condensed aromatic ring is benzimidazole, naphthimidazole, benzthiazole, naphthothiazole, benzoxazole, naphthoxazole, benzselenazole, benztelrazole, imidazole, oxazole, pyrazole, triazole, triazine, pyrimidine, pyridazine, Examples include pyrazine, pyridine, purine, quinoline, quinazoline, and the like. However, other heteroaromatic rings are also included.

The present invention also includes a mercapto derivative compound which substantially forms the above mercapto compound when contained in a dispersion of an organic acid silver salt or a silver halide grain emulsion. In particular, a mercapto derivative compound represented by the following general formula is given as a preferable example.

General Formula Ar—S—S—Ar Ar in the formula has the same meaning as in the case of the mercapto compound represented by the above general formula.

The above-mentioned heteroaromatic ring or condensed aromatic ring is, for example, a halogen atom (for example, Cl, Br, I), a hydroxyl group, an amino group, a carboxyl group, an alkyl group (for example, one or more carbon atoms, preferably Are those having 1 to 4 carbon atoms) and alkoxy groups (eg,
It may have a substituent selected from the group consisting of one or more carbon atoms, preferably those having 1 to 4 carbon atoms.

In the present invention, in addition to the above supersensitizer, the compounds represented by the following general formula (1) and macrocyclic compounds disclosed in JP 2001-330918 A are supersensitized. It can be used as an agent.

[0128]

[Chemical 2]

In the formula, H ₃₁ Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, T ₃₁ represents a divalent linking group consisting of an aliphatic hydrocarbon group or a simple bond, and J ₃₁ represents oxygen. A divalent linking group containing one or more atoms, sulfur atoms or nitrogen atoms, or a simple bond. Ra, Rb, Rc and Rd are each a hydrogen atom, an acyl group, an aliphatic hydrocarbon group,
It represents an aryl group or a heterocyclic group and may be bonded between Ra and Rb, Rc and Rd, Ra and Rc or Rb and Rd to form a nitrogen-containing heterocyclic group. M ₃₁ represents an ion necessary to cancel the charge in the molecule, and k ₃₁ represents the number of ions necessary to cancel the charge in the molecule.

In the general formula (1), the divalent linking group consisting of an aliphatic hydrocarbon group represented by T ₃₁ is a straight chain,
A branched or cyclic alkylene group (preferably having a carbon number of 1 to
20, more preferably 1 to 16, still more preferably 1 to 1
2 alkylene group), alkenylene group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12 carbon atoms), alkynylene group (preferably 2 to 20 carbon atoms, more preferably 2 carbon atoms). To 16 and more preferably 2 to 12 alkynylene groups).

Each of the above groups may have a substituent,
Examples of the substituent include an aliphatic hydrocarbon group (a linear, branched or cyclic alkyl group (preferably having 1 to 2 carbon atoms).
0, more preferably 1 to 16, still more preferably 1 to 12
), An alkenyl group (preferably having 2 to 20 carbon atoms,
More preferably 2-16, still more preferably 2-12), an alkynyl group (preferably having 2-20 carbon atoms, more preferably 2-16, still more preferably 2-12)}, an aryl group {carbon A monocyclic or condensed ring aryl group of the formulas 6 to 20 (eg, a phenyl group, a naphthyl group and the like, preferably a phenyl group)}, a heterocyclic group {3-1
0-membered saturated, unsaturated heterocyclic group (for example, 2-thiazolyl group, 1-piperazinyl group, 2-pyridyl group, 3-pyridyl group, 2-furyl group, 2-thienyl group, 2-benzimidazolyl group, Carbazolyl group etc.) and the like.

The hetero ring in the above groups may be a single ring or may form a condensed ring with another ring.

Each of the above groups may further have a substituent at an arbitrary position, and examples of the substituent include an alkyl group (including a cycloalkyl group and an aralkyl group, preferably having 1 to 20 carbon atoms, More preferably, it has 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as methyl group, ethyl group, propyl group, iso-propyl group, butyl group, tert-butyl group, heptyl group, octyl group. ,
Decyl group, undecyl group, hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, benzyl group, phenethyl group, etc., alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably Those having 2 to 8 carbon atoms, for example, vinyl group, allyl group, 2-butenyl group, 3-pentenyl group, etc., alkynyl group (preferably 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, Particularly preferably 2 to 2 carbon atoms
8 groups, for example, propargyl group, 3-pentynyl group, etc.), aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 carbon atoms).
To 12 and, for example, phenyl group, p-tolyl group, o-aminophenyl group, naphthyl group, etc., amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly Preferably, those having 0 to 6 carbon atoms,
For example, amino group, methylamino group, ethylamino group, dimethylamino group, diethylamino group, diphenylamino group, dibenzylamino group, etc., imino group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 18 carbon atoms, Particularly preferred are those having 1 to 12 carbon atoms, such as methylimino group, ethylimino group, propylimino group, phenylimino group, etc.) and alkoxy groups (preferably having 1 to 12 carbon atoms).
20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methoxy group, ethoxy group, butoxy group, etc., aryloxy group (preferably 6 to 20 carbon atoms, more It preferably has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyloxy group, a 2-naphthyloxy group, etc., an acyl group (preferably having 1 to 20 carbon atoms, and more preferably carbon). Number 1
To 16, particularly preferably 1 to 12 carbon atoms,
For example, an acetyl group, a benzoyl group, a formyl group, a pivaloyl group, etc., an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, For example, a methoxycarbonyl group, an ethoxycarbonyl group, etc., an aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, and particularly preferably 7 to 7 carbon atoms).
10 groups, for example, a phenyloxycarbonyl group, etc., an acyloxy group (preferably having 1 to 20 carbon atoms,
More preferably, those having 1 to 16 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as acetoxy group, benzoyloxy group, etc., acylamino group (preferably 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms). 16, particularly preferably those having 1 to 10 carbon atoms, for example, acetylamino group, benzoylamino group, etc., alkoxycarbonylamino group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, especially It preferably has 2 to 12 carbon atoms, for example, a methoxycarbonylamino group and the like, an aryloxycarbonylamino group (preferably having 7 carbon atoms).
To 20, more preferably 7 to 16 carbon atoms, and particularly preferably 7 to 12 carbon atoms, for example, a phenyloxycarbonylamino group, etc., a sulfonylamino group (preferably 1 to 20 carbon atoms, more preferably 1 to 1 carbon atoms
6, particularly preferably those having 1 to 12 carbon atoms, for example, methanesulfonylamino group, benzenesulfonylamino group, etc., sulfamoyl group (preferably having 0 to 2 carbon atoms).
0, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, for example, a sulfamoyl group,
Methylsulfamoyl group, dimethylsulfamoyl group,
Phenylsulfamoyl group, etc.), carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms,
Particularly preferably, those having 1 to 12 carbon atoms, for example,
A carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, a phenylcarbamoyl group, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, For example, a methylthio group, an ethylthio group), an arylthio group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, for example, a phenylthio group, etc.), a sulfonyl group. (Preferably having 1 to 20 carbon atoms, and more preferably having 1 to 1 carbon atoms.
6, particularly preferably those having 1 to 12 carbon atoms, for example, methanesulfonyl group, tosyl group, etc., sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably carbon). A methanesulfinyl group, a benzenesulfinyl group and the like), a ureido group (preferably having a carbon number of 1 to 20,
More preferably, those having 1 to 16 carbon atoms, and particularly preferably those having 1 to 12 carbon atoms, for example, ureido group, methylureido group, phenylureido group, etc., phosphoric acid amide group (preferably 1 to 20 carbon atoms, More preferably 1 carbon
To 16, particularly preferably 1 to 12 carbon atoms,
For example, diethylphosphoric acid amide group, phenylphosphoric acid amide group, etc.), hydroxyl group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, sulfino group, carboxyl Group, phosphono group, phosphino group, nitro group, hydroxamic acid group, hydrazino group, heterocyclic group (for example, imidazolyl group, benzimidazolyl group, thiazolyl group, benzothiazolyl group, carbazolyl group, pyridyl group, furyl group, piperidyl group, morpholino Groups, etc.) and the like.

Of the above groups, a salt-forming group such as a hydroxyl group, a mercapto group, a sulfo group, a sulfino group, a carboxyl group, a phosphono group and a phosphino group may be a salt. These substituents may be further substituted. When there are two or more substituents, they may be the same or different. The substituent is preferably an alkyl group, an aralkyl group, an alkoxy group, an aryl group, an alkylthio group, an acyl group, an acylamino group, an imino group, a sulfamoyl group, a sulfonyl group, a sulfonylamino group, a ureido group, an amino group, a halogen atom, and nitro. Group, heterocyclic group,
Alkoxycarbonyl group, hydroxyl group, sulfo group,
A carbamoyl group and a carboxyl group are mentioned, more preferably an alkyl group, an alkoxy group, an aryl group, an alkylthio group, an acyl group, an acylamino group, an imino group, a sulfonylamino group, a ureido group, an amino group, a halogen atom, a nitro group, and a hetero group. Ring group, alkoxycarbonyl group,
Hydroxyl group, sulfo group, carbamoyl group, carboxyl group, more preferably alkyl group, alkoxy group, aryl group, alkylthio group, acylamino group, imino group, ureido group, amino group, heterocyclic group, alkoxycarbonyl group, hydroxy A group, a sulfo group, a carbamoyl group, and a carboxyl group. The amidino group (a group in which an oxo group of a carboxyl group is substituted with an imino group and a hydroxy group is substituted with an amino group) includes those having a substituent, and examples of the substituent include an alkyl group (for example, methyl group). Group, ethyl group, pyridylmethyl group, benzyl group, phenethyl group, carboxybenzyl group, aminophenylmethyl group, etc.), aryl group (for example, phenyl group, p-tolyl group, naphthyl group, o-aminophenyl group, o- Methoxyphenyl, etc.), heterocyclic groups (eg 2
-Thiazolyl group, 2-pyridyl group, 3-pyridyl group, 2
-Furyl group, 3-furyl group, 2-thieno group, 2-imidazolyl group, benzothiazolyl group, carbazolyl group, etc.) and the like.

Examples of the divalent linking group containing at least one oxygen atom, sulfur atom or nitrogen atom represented by J ₃₁ include the following. Also, a combination of these may be used.

[0136]

[Chemical 3]

Here, Re and Rf are each the above-mentioned R.
It is synonymous with the contents defined in a to Rd.

H ₃₁ Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and the aromatic hydrocarbon group represented by H ₃₁ Ar is preferably one having 6 to 30 carbon atoms, and more preferably Is a monocyclic or condensed ring aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group and a naphthyl group, and a phenyl group is particularly preferable. The aromatic heterocyclic group represented by H ₃₁ Ar is a 5- to 10-membered unsaturated heterocyclic group containing at least one atom of N, O and S, and the heterocycle in these groups is It may be a single ring or may form a condensed ring with another ring. The heterocycle in such a heterocyclic group is preferably 5 to 6
Membered aromatic heterocycle, and a benzo-condensed ring thereof, more preferably a 5- or 6-membered aromatic heterocycle containing a nitrogen atom, and a benzo-condensed ring thereof, further preferably a nitrogen atom of 1 to 2 atoms. 5- to 6-membered aromatic heterocycles, and benzo-condensed rings thereof.

Specific examples of the heterocyclic group include, for example, thiophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole,
Triazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole,
Examples thereof include groups derived from benzimidazole, benzoxazole, benzothiazole, benzothiazoline, benzotriazole, tetrazaindene, carbazole and the like. The heterocyclic group is preferably imidazole,
Groups derived from pyrazole, pyridine, pyrazine, indole, indazole, thiadiazole, oxadiazole, quinoline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, benzothiazoline, benzotriazole, tetrazaindene, carbazole. And more preferably imidazole, pyridine, pyrazine, quinoline, phenazine, tetrazole, thiazole, benzoxazole, benzimidazole, benzothiazole, benzothiazoline, benzotriazole,
Examples include groups derived from carbazole.

The aromatic hydrocarbon group and aromatic heterocyclic group represented by H ₃₁ Ar may have a substituent, and the substituent is, for example, the same as the group mentioned as the substituent of T _31. And the preferable range is also the same. These substituents may be further substituted, and when there are two or more substituents, they may be the same or different. The group represented by H ₃₁ Ar is preferably an aromatic heterocyclic group.

Examples of the aliphatic hydrocarbon group, aryl group and heterocyclic group represented by Ra, Rb, Rc and Rd are the aliphatic hydrocarbon group, aryl group and heterocyclic group at T _31. The same can be mentioned, and the preferred range is also the same. The acyl group represented by Ra, Rb, Rc and Rd is an aliphatic or aromatic group having 1 to 12 carbon atoms, and specific examples thereof include acetyl, benzoyl, formyl and pivaloyl groups. Ra, Rb, Rc
And Rd, Ra and Rc or Rb and Rd to form a nitrogen-containing heterocyclic group, which is a saturated to unsaturated 3- to 10-membered heterocyclic group (for example, piperidine ring, piperazine ring, acridine ring, Ring groups such as a pyrrolidine ring, a pyrrole ring and a morpholine ring).

Specific examples of the acid anion as an ion necessary for offsetting the charge in the molecule represented by M ₃₁ include, for example, halogen ion (eg, chlorine ion, bromine ion,
Iodine ion), p-toluenesulfonate ion, perchlorate ion, boron tetrafluoride ion, sulfate ion, methylsulfate ion, ethylsulfate ion, methanesulfonate ion, trifluoromethanesulfonate ion and the like.

The macrocyclic compound containing a hetero atom is a 9-membered or larger macrocyclic compound containing at least one of a nitrogen atom, an oxygen atom, a sulfur atom and a selenium atom as a hetero atom. A typical compound is crown ether, which has been synthesized by Pedersen as described below in 1967 and reported a number of unique properties thereof.
These compounds are C.I. J. Pedersen, Jou
rnal of American chemical
Society vol. 86 (2495), 701
7-7036 (1967); W. Gokel, S .;
H, Korzeniowski, “Macrocycl”
ic polyethr synthesis ”, Sp
ringer-Verlag. (1982); Oda, Shono, Tabushi ed. "Crown ether chemistry" Kagaku Dojin (19
78); Tabushi et al. “Host-Guest” Kyoritsu Publishing (197)
9); Sasaki, Koga "Organic Synthetic Chemistry" Vol 45
(6), 571-582 (1987) and the like. Specific examples of the macrocyclic compound containing these heteroatoms include JP-A-2000-347343, paragraphs 0030 to
And those described in 0037.

The supersensitizer according to the present invention contains 0.00 per mol of silver in an emulsion layer containing an organic silver salt and silver halide grains.
It is preferably used in the range of 01 to 1.0 mol. It is particularly preferably used in the range of 0.01 to 0.5 mol per mol of silver.

In the present invention, as the reducing agent (silver ion reducing agent), a compound in which at least one of the reducing agents is a bisphenol derivative is used alone or in combination with other reducing agents having different chemical structures. In the silver salt photothermographic imaging material according to the present invention, performance deterioration due to fogging during CP storage of the photothermographic imaging material and color tone deterioration during storage of a silver image after thermal development can be unexpectedly suppressed.

As the reducing agent used in the present invention, the bisphenol derivative represented by the general formula (A) is used.

In formula (A), the chalcogen atom represented by X is sulfur, selenium or tellurium, preferably sulfur atom. R represents a hydrogen atom, a halogen atom, an aliphatic group having a carbon number of 7 or less, or a cyclic group having a 6-membered ring or less, and the halogen atom is, for example, a fluorine atom, a chlorine atom, a bromine atom or the like, and has a carbon number of Examples of the aliphatic group having 7 or less include methyl group, ethyl group, propyl group, butyl group, hexyl group, heptyl group, vinyl group, allyl group, butenyl group, hexadienyl group, ethenyl-2-propenyl group, 3- A butenyl group, a 1-methyl-3-propenyl group, a 3-pentenyl group, a 1-methyl-3-butenyl group, and the like, and a 6-membered or less cyclic group is an alicyclic group,
The heterocyclic group is included, and the carbocyclic group is preferably a 4- to 6-membered ring such as a cyclobutene group, a cyclopentyl group, a cyclopentenyl group, a cyclohexyl group, a cyclohexenyl group, a cyclohexadienyl group, and a phenyl group. As the group, a pyrazole ring, a pyrrole ring, a pyrrolidine ring,
A 5- or 6-membered ring such as a pyrimidine ring, a pyrazine ring, a pyridine ring, a triazine ring, a thiazole ring, a furan ring or a pyran ring is preferable, and a hydrogen atom or a cycloalkyl group, a cycloalkenyl group or a phenyl group is particularly preferable. It is a group having a structure.

These groups may further have a substituent, and examples of the substituent include a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), a cycloalkyl group (eg, cyclohexyl group, cycloheptyl). Group), a cycloalkenyl group (eg, 1-cycloalkenyl group, 2-
Cycloalkenyl group etc.), alkoxy group (eg methoxy group, ethoxy group, propoxy group etc.), alkylcarbonyloxy group (eg acetyloxy group etc.), alkylthio group (eg methylthio group, trifluoromethylthio group etc.), Carboxyl group, alkylcarbonylamino group (eg acetylamino group etc.), ureido group (eg methylaminocarbonylamino group etc.), alkylsulfonylamino group (eg methanesulfonylamino group etc.), alkylsulfonyl group (eg methane) Sulfonyl group, trifluoromethanesulfonyl group, etc.), carbamoyl group (eg, carbamoyl group, N, N-dimethylcarbamoyl group, N-morpholinocarbonyl group, etc.), sulfamoyl group (sulfamoyl group, N, N-
Dimethylsulfamoyl group, morpholinosulfamoyl group, etc.), trifluoromethyl group, hydroxyl group, nitro group, cyano group, alkylsulfonamide group (eg, methanesulfonamide group, butanesulfonamide group, etc.), alkylamino group (For example, amino group, N, N-dimethylamino group, N, N-diethylamino group, etc.), sulfo group, phosphono group, sulfite group, sulfino group,
Alkylsulfonylaminocarbonyl group (eg, methanesulfonylaminocarbonyl group, ethanesulfonylaminocarbonyl group, etc.), Alkylcarbonylaminosulfonyl group (eg, acetamidosulfonyl group, methoxyacetamidosulfonyl group, etc.), Alkynylaminocarbonyl group (eg, acetamidecarbonyl group) Group, methoxyacetamidocarbonyl group, etc.), alkylsulfinylaminocarbonyl group (eg, methanesulfinylaminocarbonyl group, ethanesulfinylaminocarbonyl group, etc.) and the like. When there are two or more substituents, they may be the same or different.

R'and R "represent a hydrogen atom, a halogen atom or a substituent. Examples of the halogen atom include a fluorine atom, chlorine atom and bromine atom, and examples of the substituent include an alkyl group, Aryl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, amino group, acyl group, acyloxy group, acylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, sulfonyl group, alkylsulfonyl group, sulfinyl Group, cyano group, heterocyclic group, etc. A plurality of R ′ and R ″ may be the same or different.

R'is preferably a secondary or tertiary alkyl group, and preferably has 2 or more carbon atoms. R ″ preferably has 1 to 5 carbon atoms, and more preferably 1 carbon atom. These groups may further have a substituent, and the substituent may be a halogen atom (eg, a fluorine atom, a chlorine atom). , Bromine atom, etc.), alkyl group (eg, methyl group,
Ethyl group, propyl group, butyl group, pentyl group, iso
-Pentyl group, 2-ethyl-hexyl group, octyl group,
Decyl group etc.), cycloalkyl group (eg cyclohexyl group, cycloheptyl group etc.), alkenyl group (eg ethenyl-2-propenyl group, 3-butenyl group, 1
-Methyl-3-propenyl group, 3-pentenyl group, 1-
Methyl-3-butenyl group etc.), cycloalkenyl group (eg 1-cycloalkenyl group, 2-cycloalkenyl group etc.), alkynyl group (eg ethynyl group, 1-propynyl group etc.), alkoxy group (eg methoxy). Group, ethoxy group, propoxy group etc.), alkylcarbonyloxy group (eg acetyloxy group etc.), alkylthio group (eg methylthio group, trifluoromethylthio group etc.), carboxyl group, alkylcarbonylamino group (eg acetylamino) Group), ureido group (eg, methylaminocarbonylamino group), alkylsulfonylamino group (eg, methanesulfonylamino group etc.), alkylsulfonyl group (eg, methanesulfonyl group, trifluoromethanesulfonyl group etc.), carbamoyl group (For example, carba Yl group, N, N- dimethylcarbamoyl group, N- morpholinocarbonyl group, etc.), a sulfamoyl group (a sulfamoyl group, N, N- dimethylsulfamoyl group, morpholinosulfonyl sulfamoyl group),
Trifluoromethyl group, hydroxyl group, nitro group, cyano group, alkylsulfonamide group (for example, methanesulfonamide group, butanesulfonamide group, etc.), alkylamino group (for example, amino group, N, N-dimethylamino group, N , N-diethylamino group, etc.), sulfo group, phosphono group, sulfite group, sulfino group, alkylsulfonylaminocarbonyl group (eg, methanesulfonylaminocarbonyl group, ethanesulfonylaminocarbonyl group, etc.), alkylcarbonylaminosulfonyl group (eg, , Acetamidosulfonyl group, methoxyacetamidosulfonyl group, etc.), alkynylaminocarbonyl group (eg, acetamidocarbonyl group, methoxyacetamidocarbonyl group, etc.), alkylsulfinylaminocarbonyl group (eg, , Methanesulfinyl aminocarbonyl group, ethanesulfinyl aminocarbonyl group)
Etc.

Specific examples of the compound represented by the general formula (A) according to the present invention include the following compounds.

[0152]

[Chemical 4]

[0153]

[Chemical 5]

[0154]

[Chemical 6]

[0155]

[Chemical 7]

Others, US Pat. No. 3,589,903
No. 4,021,249 or British Patent No. 1,
Nos. 486,148 and JP-A-51-51933
No. 50-36110, No. 50-116023,
No. 52-84727 or JP-B-51-35727
Polyphenol compounds described in the publication, for example,
2,2'-dihydroxy-1,1'-binaphthyl, 6,
6'-dibromo-2,2'-dihydroxy-1,1'-
Binaphthyl and other bisnaphthols described in U.S. Pat. No. 3,672,904, and further, for example, 4-benzenesulfonamidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4-benzenesulfone. Mention may also be made of sulfonamide phenols or sulfonamide naphthols such as those described in US Pat. No. 3,801,321 such as amidophenol, 4-benzenesulfonamide naphthol.

The use amount of the reducing agent including the compound represented by the general formula (A) is preferably 1 × 1 per mol of silver.
It is 0 ^-2 to 10 mol, particularly 1 x 10 ^{-2 to} 1.5 mol.

The amount of the reducing agent used in the photothermographic dry imaging material of the present invention depends on the type of organic silver salt or reducing agent,
Although it varies depending on other additives, it is generally 0.05 mol to 10 mol, preferably 0.1 mol to 3 mol per mol of the organic silver salt. Further, within the range of this amount, two or more kinds of the above-mentioned reducing agents may be used in combination. In the present invention, it may be preferable that the reducing agent is added and mixed in a photosensitive emulsion solution consisting of photosensitive silver halide and organic silver salt particles and a solvent immediately before coating, because photographic performance fluctuation due to stagnation time is small. is there.

Binders suitable for the photothermographic material of the present invention are transparent or translucent and generally colorless, and include natural polymers such as synthetic resins, 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, vinyl chloride, vinyl acetate, vinyl alcohol, maleic acid,
A polymer or copolymer containing an ethylenically unsaturated monomer such as acrylic acid, acrylic ester, vinylidene chloride, acrylonitrile, methacrylic acid, methacrylic acid ester, styrene, butadiene, ethylene, vinyl butyral, vinyl acetal or vinyl ether as a constituent unit. Compound, polyurethane resin, and various rubber resins. Further, a phenol resin, an epoxy resin, a polyurethane curable resin, a urea resin, a melamine resin, an alkyd resin, a formaldehyde resin, a silicone resin, an epoxy-polyamide resin, a polyester resin and the like can be mentioned. These resins are described in detail in "Plastic Handbook" published by Asakura Shoten. Typical examples of these are polyvinyl chloride, copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), polyvinyl acetals (for example, polyvinyl formal and polyvinyl butyral), polyesters, polyurethane. Kind,
Examples thereof include phenoxy resin, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetate, cellulose esters, polyamides and the like. It may be hydrophilic or non-hydrophilic.

Of these, polyvinyl acetals are preferable binders for the photosensitive layer of the photothermographic material according to the present invention, and polyvinyl butyral is particularly preferable. Details will be described later. Further, for the non-photosensitive layer such as the overcoat layer or the undercoat layer, particularly the protective layer or the backcoat layer, a polymer having a higher softening temperature, such as a cellulose ester, particularly triacetyl cellulose, a polymer such as cellulose acetate butyrate is used. preferable. The above binders may be used in combination of two or more, if necessary. The binder -COOM, -SO ₃ M,
_{-OSO 3 M, -P = O (} OM) 2, -O-P = O (O
M) ₂ , (M represents a hydrogen atom or an alkali metal base), -N (R) ₂ , -N ⁺ (R) ₃ (R represents a hydrocarbon group), epoxy group, -SH, -CN. It is preferable to use a copolymer having at least one polar group selected from the group introduced by copolymerization or an addition reaction.
₃ M and -OSO ₃ M are preferred. The amount of such a polar group is 10 ⁻¹ to 10 ⁻⁸ mol / g, preferably 10 ^−2.
It is from 10 ^-6 mol / g.

Such a binder is used within a range effective to function as a binder. The effective range can be easily determined by those skilled in the art. For example, as an index for holding at least the organic silver salt in the image forming layer, the ratio of the binder to the organic silver salt is 15: 1 to 1: 2.
Is preferable, and a range of 8: 1 to 1: 1 is particularly preferable. That is, the amount of binder in the image forming layer is preferably 1.5 to 6 g / m ² . More preferably 1.7 to 5 g / m
^{Is 2} . If it is less than 1.5 g / m ² , the density of the unexposed area may increase significantly and it may not be usable.

The glass transition temperature Tg of the binder used in the present invention is preferably 70 ° C. or higher and 105 ° C. or lower. Tg can be obtained by measurement with a differential scanning calorimeter, and the intersection of the baseline and the slope of the endothermic peak is taken as the glass transition point.

In the present invention, the glass transition temperature (Tg)
Is the "Polymer Handbook" II by Brand Wrap et al.
It was obtained by the method described on pages I-139 to III-179 (1966, Wiley and Sun Co.).

T when the binder is a copolymer resin
g is calculated by the following formula. Tg (copolymer) (° C.) = V ₁ Tg ₁ + v ₂ Tg ₂ + ...
+ V _n Tg _{n In the} formula, v ₁ , v ₂ ... V _n represent the mass fraction of the monomer in the copolymer, and Tg ₁ , Tg ₂ ... Tg _n are each The Tg (° C.) of a homopolymer obtained from a monomer is shown.

The accuracy of Tg calculated according to the above equation is ±
It is 5 ° C. The use of a binder having a Tg of 70 ° C. to 105 ° C. is preferable because a sufficient maximum density can be obtained in image formation, and generation of roller marks during heat development can be improved.

The binder of the present invention has a Tg of 70 ° C.
~ 105 ° C, number average molecular weight of 1,000 to 1,000,
000, preferably 10,000 to 500,000, and the degree of polymerization is about 50 to 1,000.

The polymer or copolymer containing the above-mentioned ethylenically unsaturated monomer as a constituent unit will be described in more detail. Examples of the ethylenically unsaturated monomer as a constituent unit of the polymer include alkyl acrylates and aryl acrylates. Examples thereof include esters, methacrylic acid alkyl esters, methacrylic acid aryl esters, cyanoacrylic acid alkyl esters, cyanoacrylic acid aryl esters, and the like, and those alkyl groups and aryl groups may be substituted. It may be omitted, specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl,
tert-butyl, amyl, hexyl, cyclohexyl, benzyl, chlorobenzyl, octyl, stearyl, sulfopropyl, N-ethyl-phenylaminoethyl, 2- (3-phenylpropyloxy) ethyl, dimethylaminophenoxyethyl, furfuryl, tetrahydrofur Furyl, phenyl, cresyl, naphthyl, 2-hydroxyethyl, 4-hydroxybutyl, triethylene glycol, dipropylene glycol, 2-methoxyethyl, 3-methoxybutyl, 2-acetoxyethyl, 2
-Acetoacetoxyethyl, 2-ethoxyethyl, 2-
iso-propoxyethyl, 2-butoxyethyl, 2-
(2-methoxyethoxy) ethyl, 2- (2-ethoxyethoxy) ethyl, 2- (2-butoxyethoxy) ethyl, 2-diphenylphosphorylethyl, ω-methoxypolyethyleneglycol (addition mole number n = 6), allyl,
Examples thereof include dimethylaminoethyl methyl chloride salt.

In addition, the following monomers can be used.
Vinyl esters (for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl chloroacetate,
Vinyl methoxyacetate, vinyl phenylacetate, vinyl benzoate, vinyl salicylate, etc.); N-substituted acrylamides, N-substituted methacrylamides and acrylamides, (N-substituents are methyl, ethyl, propyl, butyl, tert-
Butyl, cyclohexyl, benzyl, hydroxymethyl, methoxyethyl, dimethylaminoethyl, phenyl, dimethyl, diethyl, β-cyanoethyl, N- (2
-Acetoacetoxyethyl), those having each group such as diacetonyl); olefins (eg, dicyclopentadiene, ethylene, propylene, 1-butene, 1
-Pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, 2,3-dimethylbutadiene, etc .; Styrenes: for example, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene,
Isopropyl styrene, tert-butyl styrene, chloromethyl styrene, methoxy styrene, acetoxy styrene, chloro styrene, dichloro styrene, brom styrene, vinyl benzoic acid methyl ester, etc.); vinyl ethers (eg, methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, Methoxyethyl vinyl ether, dimethylaminoethyl vinyl ether, etc.); N-substituted maleimides (as N-substituents,
Methyl, ethyl, propyl, butyl, tert-butyl, cyclohexyl, benzyl, n-dodecyl, phenyl, 2-methylphenyl, 2,6-diethylphenyl,
Those having respective groups such as 2-chlorophenyl, etc.); Others, butyl crotonic acid, hexyl crotonic acid,
Dimethyl itaconate, dibutyl itaconate, diethyl maleate, dimethyl maleate, dibutyl maleate,
Diethyl fumarate, dimethyl fumarate, dibutyl fumarate, methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, glycidyl acrylate, glycidyl methacrylate, N-vinyl oxazolidone,
Examples thereof include N-vinylpyrrolidone, acrylonitrile, methacrylonitrile, methylenemalonnitrile and vinylidene chloride.

Of these, particularly preferable examples are:
Examples thereof include methacrylic acid alkyl esters, methacrylic acid aryl esters, and styrenes. Among such polymer compounds, it is preferable to use a polymer compound having an acetal group. Even a polymer compound having an acetal group is more preferably a polyvinyl acetal having an acetoacetal structure, for example, US Pat. Nos. 2,358,836 and 3,003,879.
No. 2,828,204, British Patent 771,1.
The polyvinyl acetal shown in No. 55 can be mentioned.

As the polymer compound having an acetal group according to the present invention, a compound represented by the following general formula (V) is
Particularly preferred.

[0171]

[Chemical 8]

In the formula, R ₁ represents an unsubstituted alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group, but is preferably a group other than the aryl group. R ₂ represents an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, a -COR ₃ or -CONHR _3. R ₃ is R ₁
Is synonymous with.

The unsubstituted alkyl group represented by R ₁ , R ₂ and R ₃ preferably has 1 to 20 carbon atoms, and particularly preferably 1 to 6 carbon atoms. These may be linear or branched, and linear alkyl groups are preferable. Examples of such an unsubstituted alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n
-Amyl group, t-amyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, t-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-dodecyl group Examples thereof include a group and n-octadecyl group, but a methyl group or a propyl group is particularly preferable.

The unsubstituted aryl group has 6 to 2 carbon atoms.
It is preferably 0, and examples thereof include a phenyl group and a naphthyl group. Examples of the groups substitutable for the above alkyl group and aryl group include alkyl groups (eg, methyl group, n
-Propyl group, t-amyl group, t-octyl group, n-nonyl group, dodecyl group, etc.), aryl group (eg, phenyl group, etc.), nitro group, hydroxyl group, cyano group, sulfo group, alkoxy group (eg, Methoxy group etc.), aryloxy group (eg phenoxy group etc.), acyloxy group (eg acetoxy group etc.), acylamino group (eg acetylamino group etc.), sulfonamide group (eg methanesulfonamide group etc.), Sulfamoyl group (eg, methylsulfamoyl group), halogen atom (eg, fluorine atom, chlorine atom, bromine atom), carboxy group, carbamoyl group (eg, methylcarbamoyl group), alkoxycarbonyl group (eg, methoxycarbonyl) Group), sulfonyl group (eg, methylsulfonyl group, etc.)
And so on. When there are two or more of these substituents,
It may be the same or different. The total number of carbon atoms of the substituted alkyl group is preferably 1 to 20, and the total number of carbon atoms of the substituted aryl group is preferably 6 to 20.

As R ₂ , —COR ₃ (R ₃ is an alkyl group or an aryl group) and —CONHR ₃ (R ₃ is an aryl group) are preferable. a, b, and c are values in which the mass of each repeating unit is shown by mol (mol)%, and a is 40 to 8
6 mol%, b is 0 to 30 mol%, c is 0 to 60 mol% and represents a number such that a + b + c = 100 mol%, and particularly preferably a is 50 to 86 mol% and b is 5 to 5. 25 mol% and c are in the range of 0 to 40 mol%. Each repeating unit having each composition ratio of a, b, and c may be composed of only the same or different units.

The polymer compound represented by the above general formula (V) of the present invention is synthesized by a general synthesis method described in “Vinyl acetate resin” edited by Ichiro Sakurada (Kobunshi Kagaku Kozaikai, 1962). can do.

As the polyurethane resin which can be used in the present invention, those having a known structure such as polyester polyurethane, polyether polyurethane, polyether polyester polyurethane, polycarbonate polyurethane, polyester polycarbonate polyurethane and polycaprolactone polyurethane can be used. Further, it is preferable to have at least one OH group at the end of the polyurethane molecule, for a total of two or more OH groups. Since the OH group cross-links with the polyisocyanate as the curing agent to form a three-dimensional network structure, it is preferable that a large number of OH groups be contained in the molecule. Especially O
It is preferable that the H group is at the molecular end because the reactivity with the curing agent is high. The polyurethane preferably has 3 or more OH groups at the molecular ends, and particularly preferably 4 or more OH groups. In the present invention, when polyurethane is used, the glass transition temperature is 70 to 105 ° C and the elongation at break is 10
0 to 2000%, breaking stress 0.5 to 100 N / mm ²
Is preferred.

These high molecular compounds (polymers) may be used alone or in a blend of two or more. The above polymer is used as a main binder in the image forming layer of the present invention. The term "main binder" as used herein means "a state in which the above polymer occupies 50% by mass or more of the total binder in the image forming layer". Therefore, 5 of all binders
You may blend and use another polymer in the range of less than 0 mass%. These polymers are not particularly limited as long as they are solvents in which the polymer of the present invention is soluble. More preferably, polyvinyl acetate, polyacrylic resin, urethane resin, etc. are mentioned.

In the present invention, the image forming layer may contain an organic gelling agent. The term "organic gelling agent" as used herein means, for example, a function of giving a yield value to the system by adding it to an organic liquid such as polyhydric alcohols and eliminating or lowering the fluidity of the system. Refers to compounds having.

In the present invention, it is also a preferred embodiment that the coating liquid for the image forming layer contains an aqueous dispersed polymer latex. In this case, it is preferable that 50% by mass or more of the total binder in the coating liquid for the image forming layer is a polymer latex in which the binder is aqueously dispersed.

When the image-forming layer according to the present invention contains a polymer latex, 50% by weight or more of the total binder in the image-forming layer is preferably a polymer latex, more preferably 70% by weight or more. is there.

The “polymer latex” according to the present invention is a dispersion of a water-insoluble hydrophobic polymer as fine particles in a water-soluble dispersion medium. As a dispersed state, the polymer is emulsified in a dispersion medium, emulsion-polymerized, micelle-dispersed, or the polymer chain has a partially hydrophilic structure and molecular chains themselves are molecularly dispersed. Any of these may be used.

The average particle diameter of the dispersed particles is 1 to 50,000 nm.
Is preferable, and more preferably in the range of about 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may be a wide particle size distribution or a monodisperse particle size distribution.

The polymer latex according to the present invention may be a so-called core / shell type latex in addition to the usual polymer latex having a uniform structure. In this case, it may be preferable that the core and the shell have different glass transition temperatures. The minimum film forming temperature (MFT) of the polymer latex according to the present invention is preferably −30 to 90 ° C.,
More preferably, it is about 0 to 70 ° C. Further, a film forming auxiliary may be added to control the minimum film forming temperature. The film-forming auxiliary used in the present invention is also called a plasticizer and is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of the polymer latex. For example, “Chemistry of Synthetic Latex (Munekazu Muroi, Polymer Publishing Society) Issued (1970)) "
It is described in.

The polymer species used in the polymer latex according to the present invention include acrylic resin, vinyl acetate resin, polyester resin, polyurethane resin, rubber resin, vinyl chloride resin, vinylidene chloride resin, polyolefin resin, or copolymers thereof. and so on. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more kinds of monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The number average molecular weight of the polymer is usually 5,000 to 1,000,000, preferably about 10,000 to 100,000. If the molecular weight is too small, the mechanical strength of the photosensitive layer is insufficient.

The polymer latex according to the present invention is 25
The equilibrium water content at 60 ° C and 60% RH is preferably 0.01 to 2% by mass or less, and more preferably 0.01 to 1% by mass. The definition and measurement method of the equilibrium water content can be referred to, for example, “Polymer Engineering Course 14, Polymer Material Testing Method (Polymer Society, edited by Jijijinkan)”.

Specific examples of the polymer latex according to the present invention include latex of methyl methacrylate / ethyl acrylate / methacrylic acid copolymer, latex of methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer, styrene / butadiene / acrylic acid copolymer. Latex of styrene / butadiene / divinylbenzene / methacrylic acid copolymer, latex of methyl methacrylate / vinyl chloride / acrylic acid copolymer, latex of vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer, and the like.

These polymers may be used alone or, if necessary, as a blend of two or more kinds.
The polymer type of the polymer latex preferably contains a carboxylic acid component such as an acrylate or methacrylate component in an amount of about 0.1 to 10% by mass.

If necessary, hydrophilic polymers such as gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and hydroxypropyl methyl cellulose may be added in the range of 50% by mass or less of the total binder. The addition amount of these hydrophilic polymers is preferably 30% by mass or less of the total binder of the photosensitive layer.

In the preparation of the coating liquid for the image-forming layer according to the present invention, the organic silver salt and the aqueous dispersed polymer latex may be added first, or both may be added at the same time. Good, but preferably polymer latex later.

Furthermore, it is preferable that an organic silver salt and further a reducing agent are mixed before the addition of the polymer latex. Further, in the present invention, after mixing the organic silver salt and the polymer latex, if the temperature for aging is too low, the coating surface state is impaired, and if it is too high, there is a problem that fog rises. It is preferable that the above-mentioned time is elapsed at 30 ° C to 65 ° C. Further, it is preferable to age at 35 ° C. to 60 ° C., and it is particularly preferable to age at 35 ° C. to 55 ° C. In order to maintain the temperature in this way, it is sufficient to keep the temperature of the coating solution preparation tank or the like.

For coating the coating solution for the image forming layer according to the present invention, it is preferable to use a coating solution which has been left for 30 minutes to 24 hours after mixing the organic silver salt and the polymer latex dispersed in water, and more preferably, After mixing, 60 minutes to 12 hours are allowed to pass, and particularly preferably 120 minutes to
This is to use the coating liquid after 10 hours.

Here, "after mixing" means after the organic silver salt and the aqueously dispersed polymer latex are added and the additive materials are uniformly dispersed.

In the present invention, it is known that the use of a crosslinking agent for the above binder improves the film deposition and reduces the development unevenness, but suppresses fogging during storage and printout silver after development. It also has the effect of suppressing the generation of.

As the cross-linking agent used in the present invention, various cross-linking agents conventionally used for photographic materials, for example, aldehyde-based, epoxy-based and ethyleneimine described in JP-A-50-96216 are used. Although a system, a vinyl sulfone system, a sulfonic acid ester system, an acryloyl system, a carbodiimide system, and a silane compound system crosslinking agent can be used, an isocyanate system compound, a silane compound, an epoxy compound, or an acid anhydride shown below is preferred.

The following general formula (2), which is one of the preferred ones,
The isocyanate-based and thioisocyanate-based crosslinking agents represented by will be described.

Formula (2) X = C = NL- (N = C = X) _{v In the} formula, v is 1 or 2, L is alkylene, alkenylene, an aryl group or an alkylaryl group, and v +
It represents a monovalent linking group, and X represents an oxygen or sulfur atom.

In the compound represented by the above general formula (2), the aryl ring of the aryl group may have a substituent. Examples of preferred substituents are selected from halogen atoms (eg bromine or chlorine atoms), hydroxy groups, amino groups, carboxyl groups, alkyl groups and alkoxy groups.

The above-mentioned isocyanate-based cross-linking agent is an isocyanate having at least two isocyanate groups and its adduct (adduct), and more specifically, aliphatic diisocyanates and fats having a cyclic group. Group diisocyanates, benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates and diisocyanates of these isocyanates or Three
Examples thereof include adducts with valent polyalcohols.

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

The adduct of isocyanate and polyalcohol has a particularly high ability to improve interlayer adhesion and prevent layer peeling, image misalignment and bubble generation. Such isocyanates may be placed on any part of the photothermographic material.
For example, in the support (particularly when the support is paper, it may be included in the size composition), the photosensitive layer, the surface protective layer, the intermediate layer, the antihalation layer, the undercoat layer, etc. It can be added to any layer, and can be added to one layer or two or more layers among these layers.

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

The amount of the above-mentioned crosslinking agent used in the present invention is usually 0.001 to 2 mol, preferably 0.005 to 0.5 mol, based on 1 mol of silver.

The isocyanate compound and thioisocyanate compound which can be contained in the present invention are
The compound that functions as the above-mentioned crosslinking agent is preferable, but v may be zero (0) in the above general formula, that is, a compound having only one functional group may give good results.

Examples of the silane compound which can be used as a crosslinking agent in the present invention include JP-A-2001-264930.
And compounds represented by the following general formula (3) or general formula (4).

[0206]

[Chemical 9]

In these general formulas, R ¹ , R ² ,
^{R 3, R 4, R 5} , R 6, R 7 and R ⁸ are straight optionally substituted respectively, branched or cyclic alkyl group (methyl group having 1 to 30 carbon atoms, an ethyl group, butyl group, Octyl group, dodecyl group, cycloalkyl group, etc.), alkenyl group (propenyl group, butenyl group, nonenyl group, etc.), alkynyl group (acetylene group, bisacetylene group, phenylacetylene group, etc.), aryl group or heterocyclic group (phenyl) Group, naphthyl group, tetrahydropyran group, pyridyl group, furyl group, thiophenyl group, imidazole group, thiazole group,
(Thiadiazole group, oxadiazole group, etc.), and the substituent may have either an electron-withdrawing substituent or an electron-donating substituent.

It is preferable that at least one of the substituents selected from R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ is a diffusion resistant group or an adsorptive group. R ² is preferably a diffusion resistant group or an adsorptive group.

The diffusion resistant group is preferably an aliphatic group having a carbon number of 6 or more, or an aryl group having an alkyl group having a carbon number of 3 or more, which is also called a ballast group. Diffusion resistance depends on the amount of binder and cross-linking agent used,
By introducing a diffusion resistant group, the intramolecular migration distance at room temperature is suppressed, and the reaction over time can be suppressed.

L ₁ , L ₂ , L ₃ and L ₄ represent a divalent linking group, for example, —CH ₂ — group, —CF ₂ — group, = CF— group,
-O- group, -S- group, -NH- group, -OCO- group, -C
ONH- represents group, -SO ₂ NH- group, polyoxyalkylene group, thiourea group, a polymethylene group or those combination of these groups, and the like.

M and n represent an integer of 1 to 3, m + n is 4, p1 and p2 are integers of 1 to 3, q1 and q2 are 0, 1 or 2, and p1 + q1 and p2 + q.
2 is 3 and r1 and t represent 0 or an integer of 1 to 1000.

The epoxy compound which can be used as the crosslinking agent in the present invention is not limited as long as it has one or more epoxy groups, and the number of epoxy groups, the molecular weight and the like are not limited. The epoxy group is preferably contained in the molecule as a glycidyl group via an ether bond or an imino bond. The epoxy compound may be any of a monomer, an oligomer and a polymer, and the number of epoxy groups present in the molecule is usually about 1 to 10, preferably 2 to 4. When the epoxy compound is a polymer, it may be either a homopolymer or a copolymer, and the particularly preferable range of the number average molecular weight Mn thereof is 2000 to 200.
It is about 00.

The epoxy compound used in the present invention is preferably a compound represented by the following general formula (5).

[0214]

[Chemical 10]

In the general formula (5), the substituent of the alkylene group represented by R ₁₁ is preferably a group selected from a halogen atom, a hydroxyl group, a hydroxyalkyl group or an amino group. Further, it is preferable that the linking group represented by R ₁₁ has an amide linking part, an ether linking part, and a thioether linking part. -SO ₂ Examples of the divalent linking group represented by _{X 11 -, - SO 2 NH} -, - S -, - O-, or -NR ₁₁ '- are preferred. Here, R ₁₁ ′ is a monovalent group, and is preferably an electron-withdrawing group.

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

In the present invention, the epoxy compound can be added to any layer on the photosensitive layer side of the support such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer and an undercoat layer. It can be added in layers or in two or more layers. In addition, it can be also added to any layer on the opposite side of the support from the photosensitive layer. It should be noted that any layer may be used in the case of a photosensitive material of a type having photosensitive layers on both sides.

The acid anhydride used in the present invention is a compound having at least one acid anhydride group represented by the following structural formula.

-CO-O-CO- The acid anhydride used in the present invention may be one having at least one such acid anhydride group, and the number of acid anhydride groups, the molecular weight and the like are not limited. A compound represented by the following general formula (B) is preferable.

[0220]

[Chemical 11]

In formula (B), Z represents an atomic group necessary for forming a monocyclic or polycyclic system. These ring systems may be unsubstituted or substituted. Examples of the substituent include an alkyl group (eg, methyl, ethyl, hexyl), an alkoxy group (eg, methoxy, ethoxy,
Octyloxy), aryl groups (eg phenyl, naphthyl, tolyl), hydroxy groups, aryloxy groups (eg phenoxy), alkylthio groups (eg methylthio, butylthio), arylthio groups (eg phenylthio), acyl groups (eg , Acetyl, propionyl, butyryl), sulfonyl groups (eg, methylsulfonyl, phenylsulfonyl), acylamino groups, sulfonylamino groups, acyloxy groups (eg, acetoxy, benzoxy), carboxyl groups, cyano groups, sulfo groups, and amino groups. included. The substituent preferably does not contain a halogen atom.

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

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

In the present invention, the effect of the present invention can be further enhanced by using a silver saving agent.

The silver saving agent used in the present invention is
A compound capable of reducing the amount of silver required to obtain a constant silver image density. There are various conceivable modes of action for the function of reducing the amount, but compounds having a function of improving the covering power of developed silver are preferable. Here, the covering power of developed silver means the optical density per unit amount of silver.

As the silver-saving agent, a hydrazine derivative compound represented by the following general formula (H), a vinyl compound represented by the following general formula (G), and a quaternary onium represented by the following general formula (P) are given. A compound etc. are mentioned as a preferable example.

[0227]

[Chemical 12]

[0228]

[Chemical 13]

In the general formula (H), in the formula, A₀Is it
Aliphatic group, aromatic group, and heterocyclic group, each of which may have a substituent
Group or -G₀-D₀The base is B₀Represents a blocking group,
A₁, A₂Are both hydrogen atoms, or one is a hydrogen atom and the other is
Represents an acyl group, a sulfonyl group or an oxalyl group. This
Here, G₀Is -CO- group, -COCO- group, -CS-
Group, -C (= NG₁D₁) -Group, -SO- group, -SO₂−
Group or -P (O) (G₁D ₁) -Represents a group, G₁Is just
Bond, -O- group, -S- group or -N (D₁) -Group
Then D₁Is an aliphatic group, aromatic group, heterocyclic group or hydrogen atom
Represents multiple D's in the molecule₁Are present, they are
It may be the same or different. D₀Is hydrogen atom, fat
Group, aromatic group, heterocyclic group, amino group, alkoxy group,
Aryloxy group, alkylthio group, arylthio group
Represent Preferred D₀Are a hydrogen atom, an alkyl group,
Examples thereof include an alkoxy group and an amino group.

In the general formula (H), the aliphatic group represented by A ₀ is preferably one having 1 to 30 carbon atoms, and particularly a straight chain, branched or cyclic alkyl group having 1 to 20 carbon atoms is preferable. Preferably, for example, a methyl group, an ethyl group, a t-butyl group,
Octyl group, cyclohexyl group, benzyl group, and further suitable substituents (eg, 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. The group is preferably a monocycle or a condensed ring, nitrogen, sulfur, a heterocycle containing at least one heteroatom selected from oxygen atoms, for example, a pyrrolidine ring, an imidazole ring, a tetrahydrofuran ring, a morpholine ring, a pyridine ring, a pyrimidine ring, Examples thereof 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 silver halide adsorption group. The antidiffusion group is preferably a ballast group commonly used in non-moving photographic additives such as couplers, and the ballast group is a photographically inactive alkyl group, alkenyl group, alkynyl group, alkoxy group or phenyl group. Group, a phenoxy group, an alkylphenoxy group, etc., and the total carbon number of the substituents is preferably 8 or more.

In formula (H), the silver halide adsorption promoting group is a thiourea, a thiourethane group, a mercapto group, a thioether group, a thione group, a heterocyclic group, a thioamide heterocyclic group, a mercapto heterocyclic group or a special group. Kaisho 64-9
Examples thereof include the adsorption group described in No. 0439.

In 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)
It represents a (G ₁ D ₁ )-group. Preferred G ₀ is -CO-
Group, —COCO— group, G ₁ is a mere bond,
-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, there are a plurality of D ₁ 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 preferable D ₀ is a hydrogen atom, an alkyl group, an alkoxy group, An amino group etc. are mentioned. A ₁ and A ₂ are both hydrogen atoms, or one is a hydrogen atom and the other is an acyl group (acetyl group, trifluoroacetyl group, benzoyl group, etc.), sulfonyl group (methanesulfonyl group, toluenesulfonyl group, etc.), or oxalyl group (Etoxalyl group etc.) is represented.

The compounds represented by the general formula (H) are
It can be easily synthesized by a known method. For example, US Patent Nos. 5,464,738 and 5,496,6.
It can be synthesized with reference to No. 695.

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

In the general formula (G), X ₂₁ and R ₂₁ are shown in the form of cis, but the trans form of X ₂₁ and R ₂₁ is also included in the general formula (G). This also applies to the structural representation of specific compounds.

In formula (G), X ₂₁ represents an electron-withdrawing group, W ₂₁ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a halogen atom, an acyl group or a thioacyl group. , Oxalyl group, oxyoxalyl group, thiooxalyl group, oxamoyl group, oxycarbonyl group, thiocarbonyl group, carbamoyl group, thiocarbamoyl group, sulfonyl group, sulfinyl group, oxysulfinyl group, thiosulfinyl group, sulfamoyl group, oxysulfinyl group , Thiosulfinyl group, sulfinamoyl group, phosphoryl group, nitro group,
It represents an imino group, N-carbonylimino group, N-sulfonylimino group, dicyanoethylene group, ammonium group, sulfonium group, phosphonium group, pyrylium group or immonium group.

R ₂₁ is a halogen atom, a hydroxyl 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, an alkylthio group, an arylthio group, Heterocyclic thio group, alkenylthio group, acylthio group, alkoxycarbonylthio group, aminocarbonylthio group, organic group or inorganic salt of hydroxyl group or mercapto group (for example, sodium salt, potassium salt, silver salt, etc.), amino group, Alkylamino group, cyclic amino group (for example, pyrrolidino group), acylamino group, oxycarbonylamino group, heterocyclic group (5- or 6-membered nitrogen-containing heterocycle, for example, benztriazolyl group, imidazolyl group, triazolyl group, tetrazolyl Group), ureido group It represents a sulfonamido group. X ₂₁ and W ₂₁ , and X ₂₁ and R ₂₁ may be bonded to each other to form a cyclic structure. As the ring formed by X ₂₁ and W ₂₁ ,
Examples thereof include pyrazolone, pyrazolidinone, cyclopentanedione, β-ketolactone, β-ketolactam and the like.

The general formula (G) will be described further below. X
The electron-withdrawing group represented by ₂₁ is a substituent whose substituent constant σp can take a positive value. Specifically, a substituted alkyl group (halogen-substituted alkyl, etc.), a substituted alkenyl group (cyanovinyl, etc.), a substituted / unsubstituted alkynyl group (trifluoromethylacetylenyl, cyanoacetylenyl, etc.), a substituted aryl group (cyano) Phenyl etc.), substituted / unsubstituted heterocyclic group (pyridyl, triazinyl, benzoxazolyl etc.), halogen atom, cyano group, acyl group (acetyl, trifluoroacetyl, formyl etc.), thioacetyl group (thioacetyl, thioformyl etc.) ), An oxalyl group (such as methyloxalyl), an oxyoxalyl group (such as etoxalyl), a thiooxalyl group (such as ethylthiooxalyl), an oxamoyl group (such as methyloxamoyl), an oxycarbonyl group (such as ethoxycarbonyl),
Carboxyl group, thiocarbonyl group (ethylthiocarbonyl etc.), carbamoyl group, thiocarbamoyl group, sulfonyl group, sulfinyl group, oxysulfonyl group (ethoxysulfonyl etc.), thiosulfonyl group (ethylthiosulfonyl etc.), sulfamoyl group, oxysulfinyl group Group (methoxysulfinyl, etc.), thiosulfinyl group (methylthiosulfinyl, etc.), sulfinamoyl group,
Phosphoryl group, nitro group, imino group, N-carbonylimino group (N-acetylimino etc.), N-sulfonylimino group (N-methanesulfonylimino etc.), dicyanoethylene group, ammonium group, sulfonium group, phosphonium group, pyrylium Group, immonium group,
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 preferable.

As the alkyl group represented by W ₂₁ ,
Methyl, ethyl, trifluoromethyl and the like, alkenyl groups such as vinyl, halogen-substituted vinyl and cyanovinyl, alkynyl groups such as acetylenyl and cyanoacetylenyl, and aryl groups such as nitrophenyl, cyanophenyl and pentafluorophenyl. Examples of the heterocyclic group include pyridyl, pyrimidyl, triazinyl, succinimide, tetrazolyl, triazolyl, imidazolyl, and benzoxazolyl. W ₂₁ is preferably an electron-withdrawing group having a positive σp value, and more preferably a value of 0.30 or more.

Of the above-mentioned substituents of R ₂₁ , preferred are a hydroxyl group, a mercapto group, an alkoxy group, an alkylthio group, a halogen atom, an organic or inorganic salt of a hydroxyl group or a mercapto group, and a heterocyclic group, and more preferred. Is an organic or inorganic salt of a hydroxyl group, an alkoxy group, a hydroxyl group or a mercapto group, and a heterocyclic group, and particularly preferably an organic or inorganic salt of a hydroxyl group or a mercapto group. Examples of compounds preferably used in the present invention are shown below.

[0243]

[Chemical 14]

In the general formula (P), Q represents a nitrogen atom or a phosphorus atom, R ₃₁ , R ₃₂ , R ₃₃ and R ₃₄ each represent a hydrogen atom or a substituent, and X ₃₁ ⁻ represents an anion. still,
R _{31 to} R ₃₄ may combine with each other to form a ring.

The substituent represented by R _{31 to} R ₃₄ includes 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, tetrahydro) Thienyl group, sulforanyl group, etc.), amino group and the like.

Examples of the ring formed by R _{31 to} R ₃₄ which are connected to each other include a piperidine ring, a morpholine ring, a piperazine ring, a quinuclidine ring, a pyridine ring, a pyrrole ring, an imidazole ring, a triazole ring and a tetrazole ring. .

The groups represented by R _{31 to} R ₃₄ may have a substituent such as a hydroxyl group, an alkoxy group, an aryloxy group, a carboxyl group, a sulfo group, an alkyl group or an aryl group. As R ₃₁ , R ₃₂ , R ₃₃ and R ₃₄ , a hydrogen atom and an alkyl group are preferable.

[0248] X ₃₁ ^- as an anion represented by the halogen ion, sulfate ion, nitrate ion, acetate ion, and inorganic and organic anions, such as p- toluenesulfonic acid ion.

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

The antifoggant and image stabilizer used in the photothermographic material of the invention will be described.

Since a reducing agent having a proton such as bisphenols and sulfonamidephenols is mainly used as the reducing agent, it is reduced by generating active species capable of abstracting hydrogen. It is preferable to contain a compound capable of inactivating the agent.
The colorless photo-oxidizable substance is preferably a compound capable of generating a free radical as a reactive species during exposure.

Therefore, any compound having these functions may be used, but an organic free radical composed of a plurality of atoms is preferable. A compound having any structure may be used as long as it has such a function and does not cause any particular adverse effect on the silver salt photothermographic material.

In addition, as a compound that generates these free radicals, a carbocyclic group, or a carbocyclic group, is provided in order to have stability such that the generated free radical can be contacted with the reducing agent for a sufficient time to react with the reducing agent and inactivate it. Those having a heterocyclic aromatic group are preferable.

As typical examples of these compounds, the following biimidazolyl compounds and iodonium compounds can be given.

Examples of the biimidazolyl compound include those represented by the following general formula (6).

[0256]

[Chemical 15]

In the formula, each of R ₄₁ , R ₄₂ and R ₄₃ (identical or different) is an alkyl group (eg methyl, ethyl,
Hexyl), alkenyl group (eg vinyl, allyl), alkoxy group (eg methoxy, ethoxy, octyloxy), aryl group (eg phenyl, naphthyl, tolyl), hydroxyl group, halogen atom, aryloxy group (eg, Phenoxy), alkylthio group (for example, methylthio, butylthio), arylthio group (for example, phenylthio), acyl group (for example, acetyl, propionyl, butyryl, valeryl), sulfonyl group (for example, methylsulfonyl, phenylsulfonyl), acylamino group, A sulfonylamino group, an acyloxy group (for example, acetoxy, benzoxy), a carboxyl group, a cyano group, a sulfo group and an amino group are shown. Of these, more preferred substituents are aryl groups, alkenyl groups and cyano groups.

The above-mentioned biimidazolyl compounds are described in US Pat. No. 3,734,733 and British Patent No. 1,271,17.
It can be manufactured by the manufacturing method described in No. 7 and a method similar thereto. Preferred specific examples are given below.

[0259]

[Chemical 16]

[0260]

[Chemical 17]

Similarly, suitable compounds include the iodonium compounds represented by the following general formula (7).

[0262]

[Chemical 18]

In the formula, Q ¹¹ includes an atom necessary for completing a 5-, 6- or 7-membered ring, and the necessary atom is selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom.
Each of R ¹¹ , R ¹² and R ¹³ (identical or different) is a hydrogen atom, an alkyl group (eg methyl, ethyl, hexyl), an alkenyl group (eg vinyl, allyl), an alkoxy group (eg methoxy, ethoxy). , Octyloxy), aryl groups (eg phenyl, naphthyl, tolyl), hydroxyl groups, halogen atoms, aryloxy groups (eg phenoxy), alkylthio groups (eg,
Methylthio, butylthio), arylthio groups (eg,
Phenylthio), acyl group (eg, acetyl, propionyl, butyryl, valeryl), sulfonyl group (eg, methylsulfonyl, phenylsulfonyl), acylamino group, sulfonylamino group, acyloxy group (eg, acetoxy, benzoxy), carboxyl group, cyano A group, a sulfo group and an amino group are shown. Of these, more preferred substituents are aryl groups, alkenyl groups and cyano groups.

R ¹⁴ is a carboxylate group such as acetate, benzoate or trifluoroacetate and O ^−.
Indicates. w represents 0 or 1.

[0265] X ₀ ^- is an anionic counterion, as suitable ^{_{examples, CH 3 CO 2 -, CH}} 3 SO 3 - and PF ₆ ^- is.

When R ¹³ is a sulfo group or a carboxyl group, w is 0 and R ¹⁴ is O ⁻ .

Any of R ¹¹ , R ¹² and R ¹³ may combine with each other to form a ring. Of these, particularly preferable compounds are represented by the following general formula (8).

[0268]

[Chemical 19]

Here, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ ,
X ₀ ^−, w and the like have the same meanings as in the general formula (7),
Y ¹¹ carbon atoms represent a; (pyridine ring -N =) or represents (-CH = benzene ring), or nitrogen atom.

The above-mentioned iodonium compound is Org. Sy
n. , 1961 and "Advanced by Fieser.
Organic Chemistry ”(Reinh
old, N.N. Y. , 1961) and a method similar thereto.

The addition amount of the compounds represented by the above general formulas (6) and (7) is 0.001 to 0.1 mol / m ² , preferably 0.005 to 0.05 mol / m ² . It is a range. In addition, the compound is a photosensitive material of the present invention,
It can be contained in any constituent layer, but it is preferably contained in the vicinity of the reducing agent.

Further, in the present invention, a compound in which the reactive active species is not a halogen atom is preferable as the compound which inactivates the reducing agent and prevents the reducing agent from reducing the organic silver salt to silver. The compound which releases as a compound can also be used in combination with the compound which releases an active species which is not a halogen atom of the present invention. Many compounds are known that can release a halogen atom as an active species, and good effects can be obtained by using them in combination.

Specific examples of the compounds which generate these active halogen atoms include the compounds of the following general formula (9).

[0274]

[Chemical 20]

In formula (9), Q ₅₁ represents an aryl group or a heterocyclic group. X ₅₁ , X ₅₂ and X ₅₃ represent a hydrogen atom, a halogen atom, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group or an aryl group, and at least one is a halogen atom. Y ₅₁
-C (= O) is -, - SO- or -SO ₂ - represents a.

The aryl group represented by Q ₅₁ may be monocyclic or condensed, and is preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms (eg phenyl, naphthyl etc.), A phenyl group and a naphthyl group are more preferable, and a phenyl group is still more preferable.

The heterocyclic group represented by Q ₅₁ is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one atom of N, O or S, which may be a monocyclic ring. Good, or may form a condensed ring with another ring.

The heterocyclic group is preferably a 5- or 6-membered unsaturated heterocyclic group which may have a condensed ring, and more preferably a 5- or 6-membered aromatic group which may have a condensed ring. It is a group heterocyclic group. More preferably, it is a 5- to 6-membered aromatic heterocyclic group which may have a condensed ring containing a nitrogen atom, and particularly preferably, it may have a condensed ring containing 1 to 4 atoms containing a nitrogen atom. Or a 6-membered aromatic heterocyclic group. As the hetero ring in such a heterocyclic group, preferably imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole,
Purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, indolenine, tetrazaindene Yes, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benz. Thiazole and tetrazaindene, more preferably imidazole and pyridene. Down, pyrimidine, pyrazine,
Pyridazine, triazole, triazine, thiadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, benzimidazole, benzthiazole, particularly preferably pyridine, thiadiazole, quinoline, benzthiazole.

The aryl group and heterocyclic group represented by Q ₅₁ may have a substituent in addition to —Y ₅₁ —C (X ₅₁ ) (X ₅₂ ) (X ₅₃ ), and the substituent is preferable. Is an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonyl group. Amino group, sulfamoyl group, carbamoyl group, sulfonyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, sulfo group, carboxyl group, nitro group, a heterocyclic group, more preferably an alkyl group, an aryl group,
Alkoxy group, aryloxy group, acyl group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, nitro group , A heterocyclic group, more preferably an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an acylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, a halogen atom, a cyano group, a nitro group, a heterocycle. A group, particularly preferably an alkyl group, an aryl group or a halogen atom.

X ₅₁ , X ₅₂ and X ₅₃ are preferably a halogen atom, a haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group,
A sulfamoyl group, a sulfonyl group, a heterocyclic group,
A halogen atom, a haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group and a sulfonyl group are more preferable, a halogen atom and a trihalomethyl group are still more preferable, and a halogen atom is particularly preferable. Among the halogen atoms, chlorine atom, bromine atom and iodine atom are preferable, chlorine atom and bromine atom are more preferable, and bromine atom is particularly preferable.

Y ₅₁ is -C (= O)-, -SO-, -SO
₂ −, preferably —SO ₂ —.

The addition amount of these compounds is preferably in a range such that the increase of printout silver due to the formation of silver halide does not substantially pose a problem, and the ratio to the compound not producing active halogen radicals is 150% or less at the maximum.
More preferably, it is 100% or less.

In addition to the above compounds, the silver salt photothermographic dry imaging material of the present invention may contain compounds conventionally known as antifoggants, but similar to the above compounds. It may be a compound capable of generating various reactive species or a compound having a different fogging prevention mechanism. For example, US Pat. No. 3,589,903,
4,546,075, 4,452,885, JP-A-59-57234, and U.S. Pat. No. 3,874,94.
No. 6, 4,756,999, JP-A-9-28832.
The compounds described in No. 8 and No. 9-90550 are mentioned. Further, other antifoggants include US Pat. No. 5,028,523 and European Patent 600,5.
87, 605, 981 and 631,176.

The heat-developable light-sensitive material of the present invention forms a photographic image by a heat-development treatment, and in the state where a toning agent for adjusting the color tone of silver is dispersed in a normal (organic) binder matrix, if necessary. It is preferably contained.

Examples of suitable toning agents used in the present invention are R
essearch Disclosure No. 17029
U.S. Pat. Nos. 4,123,282 and 3,99
No. 4,732, No. 3,846,136 and No. 4,021,249 are disclosed, for example, as follows.

Imides (eg, succinimide, phthalimide, naphthalimide, N-hydroxy-1,8)
-Naphthalimide); mercaptans (for example, 3-
Mercapto-1,2,4-triazole); phthalazinone derivatives or metal salts of these derivatives (for example, phthalazinone, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, And 2,3-dihydro-1,4-phthalazinedione); phthalazine and phthalic acids (eg, phthalic acid, 4
-Methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic acid); phthalazine and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivatives and their anhydrides (for example,
Phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) in combination with at least one compound. A particularly preferred toning agent is phthalazinone or a combination of phthalazine and phthalic acids or phthalic anhydrides.

Regarding the color tone of the output image for medical diagnosis, it is said that a cold image tone makes it easier for a reader of an X-ray photograph to obtain a more accurate diagnostic observation result of a recorded image. Here, the cold image tone is a pure black tone or a bluish black tone in which the black image is bluish, and the warm image tone is a warm black tone in which the black image is brownish. Say

The terms "more cool" and "more warm" with respect to color tones refer to the minimum density Dmin and the optical density D = 1.0.
_Is obtained by the hue angle h _{ab at} . The hue angle h _ab is calculated using the color coordinates a ^* and b ^* of the L ^* a ^* b ^* color space, which is a color space recommended by the International Commission on Illumination (CIE) in 1976 and has a perceptually nearly uniform rate. Calculate by the following formula.

H _ab = tan ^-1 (b ^* / a ^* ) In the present invention, when used as a medical image, a preferable range of h _ab is 180 ° <h _ab <270 °, and more preferably 200 ° <. h _ab <270 °, most preferably 220 ° <h _ab <260 °.

In the photothermographic material of the invention, the average particle size of the matting agent contained in the outermost surface on the side having the image forming layer is Le.
(Μm), where Lb (μm) is the average particle size of the matting agent contained in the outermost surface on the side having the backcoat layer, Lb /
Le is preferably 1.5 or more and 10 or less. Lb
By setting / Le within this range, uneven density during heat development can be improved.

In the present invention, the object of the present invention is to provide the surface layer of the photothermographic material (even when the non-photosensitive layer is provided on the image forming layer side or on the opposite side of the image forming layer with the support sandwiched). Further, it is preferable to use an organic or inorganic powder as a matting agent in order to control the surface roughness. As the powder used in the present invention, it is preferable to use a powder having a Mohs hardness of 5 or more. As the powder, a known inorganic powder or organic powder can be appropriately selected and used. Examples of the inorganic powder include titanium oxide, boron nitride, SnO ₂ , SiO ₂ , Cr ₂ O ₃ and α-Al.
₂ O ₃ , α-Fe ₂ O ₃ , α-FeOOH, SiC, cerium oxide, corundum, artificial diamond, garnet, garnet, mica, silica, silicon nitride, silicon carbide and the like can be mentioned. As the organic powder, for example,
Powders of polymethylmethacrylate, polystyrene, Teflon (R) and the like can be mentioned. Of these, preferred are SiO ₂ , titanium oxide, barium sulfate,
α-Al ₂ O ₃ , α-Fe ₂ O ₃ , α-FeOOH, Cr ₂
Inorganic powders such as O ₃ and mica, among which Si
O ₂ and α-Al ₂ O ₃ are preferable, and Si is particularly preferable.
It is O ₂ .

In the present invention, the powder is preferably surface-treated with a Si compound and / or an Al compound. The use of such surface-treated powder can improve the surface condition of the uppermost layer. The content of Si and / or Al is S based on the powder.
It is preferable that i is 0.1 to 10% by mass and Al is 0.1 to 10% by mass, more preferably 0.1 to 5% by mass of Si and 0.1 to 5% by mass of Al. Si is 0.1
2% by mass and 0.1 to 2% by mass of Al are particularly preferable. Further, the mass ratio of Si and Al is preferably Si <Al. The surface treatment can be performed by the method described in JP-A-2-83219. The average particle diameter of the powder in the present invention means the average diameter of the spherical powder, the average major axis length of the acicular powder, the maximum diagonal length of the plate surface of the plate powder. Means the average value of each and can be easily obtained from measurement by an electron microscope.

The above-mentioned organic or inorganic powder used in the present invention preferably has an average particle size of 0.5 μm to 10 μm, more preferably 1.0 μm to 8.0 μm.

The average particle diameter of the organic or inorganic powder contained in the outermost layer on the side of the photosensitive layer is usually 0.5 μm to 8.0 μm, preferably 1.0 μm to 6.0 μm, more preferably 2.0 μm to 5 μm. It is 0.0 μm. The addition amount is usually 1.0% by mass to 20% by mass with respect to the amount of the binder used in the outermost layer (including the amount of the curing agent in the amount of the binder),
The amount is preferably 2.0% by mass to 15% by mass, more preferably 3.0% by mass to 10% by mass. The average particle diameter of the organic or inorganic powder contained in the outermost layer on the side opposite to the photosensitive layer side of the support is usually 2.0 μm to 15.0 μm,
It is preferably 3.0 μm to 12.0 μm, and more preferably 4.0 μm to 10.0 μm. The addition amount is usually 0.2% by mass to 10% by mass with respect to the amount of the binder used in the outermost layer (included in the amount of the binder for the curing agent).
And is preferably 0.4% by mass to 7% by mass, more preferably 0.6% by mass to 5% by mass.

As the coefficient of variation of the particle size distribution,
It is preferably 50% or less, more preferably 4
The powder is 0% or less, and particularly preferably 30% or less.

Here, the variation coefficient of the particle size distribution is a value represented by the following formula. {(Standard deviation of particle size) / (average value of particle size)} × 100 The method of adding the organic or inorganic powder according to the present invention may be a method of previously dispersing and coating in a coating liquid, A method of spraying an organic or inorganic powder after applying the coating solution and before completion of drying may be used. When adding a plurality of types of powder, both methods may be used in combination.

Materials for the support used in the photothermographic material according to the present invention include various polymer materials, glass, wool cloth,
Examples of the material include cotton cloth, paper, metal (for example, aluminum) and the like, and those which can be processed into a flexible sheet or roll are preferable in terms of handling as an information recording material.
Therefore, as the support in the photothermographic material of the present invention, a plastic film (eg, cellulose acetate film, polyester film, polyethylene terephthalate film, polyethylene naphthalate film, polyamide film, polyimide film, cellulose triacetate film or polycarbonate film) is preferable. In the present invention, a biaxially stretched polyethylene terephthalate film is particularly preferable. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.

In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer may be contained in the constituent layer in order to improve the charging property. These may be contained in any layer, but are preferably contained in the backing layer or the surface protective layer on the photosensitive layer side, the undercoat layer and the like. In the present invention, US Pat. No. 5,244,773
Conductive compounds described in No. columns 14 to 20 are preferably used.

Of these, in the present invention, it is preferable that the surface protective layer on the backing layer side contains a conductive metal oxide. It was found that the effect of the present invention (particularly, the transportability during the heat development treatment) can be further enhanced by this. here,
Conductive metal oxides are crystalline metal oxide particles, and those that contain oxygen vacancies and those that contain a small amount of different atoms forming donors with respect to the metal oxide used are generally conductive. In particular, the latter is particularly preferable because it does not give a fog to the silver halide emulsion. Examples of metal oxides include ZnO, TiO ₂ , SnO ₂ ,
Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, Mo
O ₃ , V ₂ O _5, etc., or composite oxides of these are preferable,
ZnO, TiO ₂ and SnO ₂ are particularly preferable. Examples of containing a different atom include Al and In for ZnO.
It is effective to add Sb, Nb, P, a halogen element and the like to SnO _{2, and} to add Nb and Ta to TiO ₂ . The addition amount of these different kinds of atoms is 0.
The range of 01 mol% to 30 mol% is preferable, but 0.
It is particularly preferably 1 mol% to 10 mol%. Furthermore, in order to improve the dispersibility and transparency of the fine particles, a silicon compound may be added during the production of the fine particles. The metal oxide fine particles used in the present invention have conductivity, and their volume resistivity is 10 ⁷ Ωcm or less, particularly 10 ⁵ Ωcm or less. Regarding these oxides, JP-A-56-143431,
56-120519, 58-62647 and the like. Further, as described in JP-B-59-6235, a conductive material in which the above-mentioned metal oxide is attached to other crystalline metal oxide particles or fibrous material (for example, titanium oxide) may be used. .

The particle size that can be used is preferably 1 μm or less.
However, if it is 0.5 μm or less, the stability after dispersion is good.
Easy to use. In addition, to minimize the light scattering property
In addition, if conductive particles of 0.3 μm or less are used, it becomes transparent
It is possible to form a material, which is very preferable. In addition,
If the conductive metal oxide is acicular or fibrous, its length
Is preferably 30 μm or less and the diameter is 1 μm or less.
The preferred length is 10 μm or less and the diameter is 0.3 μm or less.
Yes The length / diameter ratio is 3 or more. Note that SnO ₂age
Is commercially available from Ishihara Sangyo Co., Ltd., and SNS10
M, SN-100P, SN-100D, FSS10M
Which can be used.

The photothermographic material of the present invention has at least one image forming layer which is a photosensitive layer on a support. Although only the image forming layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the image forming layer. For example, a protective layer is preferably provided on the image forming layer for the purpose of protecting the image forming layer, and sticking between the heat developing materials or on the roll of the heat developing material is prevented on the opposite surface of the support. In order to do so, a back coat layer is provided. As the binder used for these protective layers and back coat layers, the glass transition point is higher than that of the image forming layer, and scratches and polymers that are less likely to be deformed, for example, polymers such as cellulose acetate and cellulose acetate butyrate are the binders described above. Selected from among

Two or more image forming layers may be provided on one side of the support or one or more layers on both sides of the support in order to adjust the gradation.

In the photothermographic material according to the present invention,
In order to control the amount or wavelength distribution of light transmitted through the image forming layer, it is preferable to form a filter layer on the same side as or opposite to the image forming layer, or to add a dye or a pigment to the image forming layer.

The dyes used in the present invention include:
Known compounds that absorb light in various wavelength regions depending on the color sensitivity of the heat-developable material can be used.

For example, when the heat-developable material according to the present invention is used as an image recording material for infrared light, it is disclosed in JP-A-2001-8.
Squalylium dyes having thiopyrylium nuclei (herein referred to as thiopyrylium squarylium dyes) and squarylium dyes having pyrylium nuclei (herein referred to as pyrylium squarylium dyes), and squarylium dyes as disclosed in 3655. It is preferable to use a thiopyrylium croconium dye or a pyrylium croconium dye similar to.

The compound having a squarylium nucleus means 1-cyclobutene-2-hydroxy- in the molecular structure.
A compound having 4-one and a compound having a croconium nucleus is a compound having 1-cyclopentene-2-hydroxy-4,5-dione in the molecular structure. Here, the hydroxy group may be dissociated. Hereinafter, in the present specification, these dyes are collectively referred to as a squarylium dye for convenience. Incidentally, as the dye, JP-A 8-201959 is used.
Compounds of No. are also preferred.

The photothermographic material of the present invention comprises a coating solution prepared by dissolving or dispersing the materials for the respective constituent layers described above in a solvent,
It is preferable that a plurality of these coating solutions are simultaneously applied in a multi-layer coating and then heat treatment is performed. Here, "a plurality of layers are coated 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, each layer is separately coated and dried. It means that each constituent layer can be formed in a state in which the steps of simultaneously performing multilayer coating and drying can be simultaneously performed. That is, the upper layer is provided before the residual amount of all the solvents in the lower layer becomes 70% by mass or less.

There are no particular restrictions on the method for applying multiple layers of each constituent layer at the same time, and known methods such as bar coater method, curtain coating method, dipping method, air knife method, hopper coating method, extrusion coating method and the like can be used. Can be used. Of these, the pre-weighing type coating method called the extrusion coating method is more preferable. The extrusion coating method is suitable for precision coating and organic solvent coating because it does not volatilize on the slide surface unlike the slide coating method. This coating method has been described for the side having the photosensitive layer, but the same applies to the case where the backcoat layer is coated together with undercoating. Regarding the simultaneous multi-layer coating method for a heat developing material, Japanese Patent Application Laid-Open No.
00-15173 has detailed description.

In the present invention, the coated silver amount is preferably selected in accordance with the purpose of the photothermographic material, but in the case of a medical image, it is 0.3 g / m ^2.
It is preferably 1.5 g / m ² or less and more preferably 0.5 g / m ² or more and 1.5 g / m ² or less. Of the coated silver amount, those derived from silver halide are 2% of the total silver amount.
-18% is preferable, and further 5% -15
% Is preferred.

In the present invention, the coating density of silver halide grains of 0.01 μm or more (sphere-equivalent grain size) is 1
It is preferably from 1014 pieces / m ^{2 to} 1 × 1018 pieces / m ² . Furthermore, 1 × 1015 pieces / m ² or more 1 × 1017
The number / m ² or less is preferable.

Further, the coating density of the non-photosensitive long-chain aliphatic carboxylic acid silver is 1 × 10 ^-17 g or more per 1 silver halide grain of 0.01 μm or more (sphere-equivalent grain size). ^{X10 -15} g or less is preferable, 1 x 10 ^-16 g or more 1
It is more preferably × 10 ^-14 g or less.

When coating is carried out under the conditions within the above range, the optical maximum density of the silver image per constant coating silver amount, that is, the silver coating amount (covering power) and the color tone of the silver image, etc. From the viewpoint, favorable results are obtained.

In the present invention, the photothermographic material is the
5 to 1000 mg / m of solvent at the time of image formation ²In the range of
Is preferred. 100-500 mg / m²Is
Is more preferable. It makes you feel high
It is a photothermographic material with high degree, low fog and high maximum density.

As the solvent used in the present invention, acetone,
Ketones such as methyl ethyl ketone and isophorone; alcohols such as methyl alcohol, ethyl alcohol, i-propyl alcohol, cyclohexanol and benzyl alcohol; ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol,
Glycols such as hexylene glycol; ether alcohols such as ethylene glycol monomethyl ether and diethylene glycol monoethyl ether; ethers such as i-propyl ether; esters such as ethyl acetate, butyl acetate; methylene chloride, dichlorobenzene, etc. Chlorides; hydrocarbons and the like can be mentioned. Other examples include water, formamide, dimethylformamide, toluidine, tetrahydrofuran, acetic acid and the like. However, it is not limited to these. Also, these solvents are
Alternatively, several types can be used in combination.

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

When the photothermographic material of the present invention is stored, it is preferable to store the photothermographic material in a package in order to prevent changes in density and fog. The porosity in the package is preferably 0.01 to 10%, preferably 0.02 to 5%, and nitrogen filling is performed to reduce the nitrogen partial pressure in the package to 8%.
It is preferably 0% or more, and more preferably 90% or more.

The photothermographic material of the present invention generally uses a laser beam when recording an image. For exposure of the photothermographic material of the present invention, it is desirable to use a light source suitable for the color sensitivity imparted to the material. For example, if the material is made to be sensitive to infrared light, it can be applied to any light source in the infrared light range, but the laser power is high and the photothermographic material is transparent. From the point that it can be done, the infrared semiconductor laser (780 nm, 820 n
m) is more preferably used.

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

Here, "substantially no vertical" means that the angle is the most vertical during laser beam scanning, preferably 55 degrees or more and 88 degrees or less, more preferably 60 degrees or more and 86 degrees or less, and further It is preferably 65 degrees or more and 84 degrees or less, and most preferably 70 degrees or more and 82 degrees or less.

The beam spot diameter on the exposed surface of the photosensitive material when the laser light is scanned on the photosensitive material is preferably 200 μm or less, more preferably 100 μm or less. It is preferable that the spot diameter is smaller because the angle of deviation of the laser light incident angle from the vertical can be reduced. 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 occurrence of interference fringe-like unevenness.

As the second method, it is also preferable that the exposure in the present invention is carried out by using a laser scanning exposure device which emits scanning laser light of a vertical multi type. Image quality deterioration such as occurrence of interference fringe-like unevenness is reduced as compared with the vertical single mode scanning laser light.

In order to achieve vertical multi, a method of utilizing return light by multiplexing, applying high frequency superposition, or the like is preferable.
The vertical multi means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm.
It is preferable that the thickness is not less than nm. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

Further, as a third aspect, it is also preferable to form an image by scanning exposure using two or more laser beams.

As an image recording method using such a plurality of laser beams, there is a need for high resolution and high speed.
This is a technique used in an image writing means of a laser printer or a digital copying machine for writing an image in plural lines by scanning once, and is known from, for example, JP-A-60-166916. This is a method in which a laser beam emitted from a light source unit is deflected and scanned by a polygon mirror and an image is formed on a photoconductor through an fθ lens or the like. This is the same laser scanning optical device as that of a laser imager in principle. Is.

The image formation of the laser beam on the photosensitive member in the image writing means of the laser printer or the digital copying machine is performed from one laser beam image forming position because the image is written in plural lines by one scanning. The next laser beam is imaged with a shift of one line. Specifically, the two light beams are close to each other in the sub-scanning direction on the image plane at intervals of several tens of μm, and the printing density is 400 dpi (in the present invention, 1 inch, that is, dots per 2.54 cm). Print density is dpi (dot per inch)
2), the pitch of the two beams in the sub-scanning direction is 63.5.
μm and 42.3 μm at 600 dpi. Unlike the method in which the resolution is shifted in the sub-scanning direction, it is preferable in the present invention to form an image by converging two or more lasers at the same location on the exposure surface while changing the incident angle. At this time, the exposure energy on the exposure surface when writing with one normal laser beam (wavelength λ [nm]) is E, and N laser beams used for exposure have the same wavelength (wavelength λ [n]).
m]) and the same exposure energy (E _n ),
Preferably in the range of _{0.9 × E ≦ E n × N} ≦ 1.1 × E. By doing so, although energy is secured on the exposed surface, reflection of each laser beam to the image forming layer is reduced because the exposure energy of the laser is low, and eventually the occurrence of interference fringes is suppressed.

In the above description, the wavelengths of a plurality of laser beams are the same as λ, but different wavelengths may be used. In this case, for λ [nm], (λ-3
0) <λ ₁ , λ ₂ , ... λ _n ≦ (λ + 30) is preferable.

In the image recording methods of the above-mentioned first, second and third modes, the laser used for scanning exposure is generally well known, such as ruby laser and YAG laser.
Solid-state lasers such as lasers and glass lasers; He-Ne lasers, Ar ion lasers, Kr ion lasers, CO ₂ lasers, CO lasers, He-Cd lasers, N ₂ lasers, gas lasers such as excimer lasers; InGaP lasers, Al
GaAs laser, GaAsP laser, InGaAs laser, InAsP laser, CdSnP ₂ laser, GaSb
Semiconductor lasers such as lasers; chemical lasers, dye lasers, etc. can be selected and used in a timely manner according to the application, but among them, the wavelength is 60 due to problems of maintenance and size of light source.
Laser light from a semiconductor laser of 0 to 1200 nm is preferably used. In addition, laser imager and laser
In the laser light used in the imagesetter, the beam spot diameter on the exposed surface of the material when scanning the heat developing material is generally in the range of 5 to 75 μm as the minor axis diameter and 5 to 100 μm as the major axis diameter. The laser beam scanning speed can be set to an optimum value for each photothermographic material by the sensitivity and laser power at the laser oscillation wavelength peculiar to the photothermographic material.

The thermal development processing apparatus referred to in the present invention has, as its constitution, a film supply section typified by a film tray, a laser image recording section, and a thermal development section for supplying uniform and stable heat to the entire surface of the photothermographic material. , A conveyance section from the film supply section through the laser recording to the discharge of the photothermographic material on which an image is formed by heat development to the outside of the apparatus. A specific example of the heat development processing apparatus of this aspect is shown in FIG.

The thermal developing apparatus 100 comprises a sheet feeding section 110 for feeding sheet-like photothermographic materials (also referred to as photothermographic elements or simply films) one by one.
An exposure unit 120 that exposes the fed film F, a developing unit 130 that develops the exposed film F, a cooling unit 150 that stops development, and a stacking unit 160 are provided, and the film F is fed from the feeding unit. Supply roller pair 140, a supply roller pair 144 for feeding the film to the developing section, and a transport roller pair 14 for smoothly transferring the film F between the respective sections.
1, 142, 143, 145 and the like. The heat developing section serves as a heating means for developing the film F, and a heat drum 1 having a plurality of opposing rollers 2 that can be heated while being held in close contact with the outer periphery, and a peeling section for separating the developed film F and sending it to the cooling section. It consists of nails 6 and the like.

The transfer speed of the photothermographic material is 20 m.
A preferable range is m / sec to 200 mm / sec.

The development conditions of the heat developable material of the present invention vary depending on the equipment, device or means used, but typically, the heat developable material imagewise exposed is heated at a suitable high temperature. By doing so, development is performed. The latent image obtained after exposure has a moderately high temperature (about 80-200 ° C,
Development is carried out by heating the heat-developable material at a temperature of preferably about 100 to 200 ° C. for a sufficient period of time (generally about 1 second to about 2 minutes).

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 exceeds 200 ° C., the binder is melted, and the transferability to the roller and the developing property as well as the image itself such as transfer. It also adversely affects the machine. By heating, a silver image is generated by a redox reaction between an organic silver salt (which functions as an oxidizing agent) and a reducing agent. This reaction process proceeds without supplying any processing liquid such as water from the outside.

The heating device, device or means may be, for example, a hot plate, an iron, a hot roller, a heating means typical of a heat generator using carbon or white titanium or the like. More preferably, the heat-developable material provided with the protective layer is subjected to heat treatment by bringing the surface having the protective layer into contact with a heating means, in order to perform uniform heating, and also to improve thermal efficiency, workability, etc. Preferable from a viewpoint,
It is preferable that the surface on the side having the protective layer is conveyed while being brought into contact with a heat roller, heated, and developed.

[0334]

The present invention will be described in detail below with reference to examples, but embodiments of the present invention are not limited to these.

Example 1 [Preparation of undercoated photographic support] Commercially available biaxially stretched and heat-fixed 175 μm thick optical density 0.170 (measured by Konica Corporation densitometer PDA-65). 8W / on both sides of PET film which is colored blue with blue dye
Corona discharge treatment for m ² · min is applied, and one surface is coated with the following undercoating coating solution a-1 to a dry film thickness of 0.8 μm and dried to form the undercoating layer A-1, and vice versa. The undercoating coating solution b-1 described below was applied to the side surface so as to have a dry film thickness of 0.8 μm, and dried to obtain an undercoating layer B-1.

[0336]

[Chemical 21]

<< Undercoating Coating Liquid 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 Finish with water to 1 liter << Subbing coating liquid b-1 >> Butyl acrylate (40 mass% ) Styrene (20 mass%) Glycidyl acrylate (40 mass%) Copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g After finishing with water to 1 liter, on the upper surface of the undercoat layer A-1 and the undercoat layer B-1,
A corona discharge of 8 W / m ² · min was applied, and the following undercoating upper layer coating liquid a-2 was dried to a thickness of 0.1 μm on the undercoating layer A-1.
As the undercoating upper layer A-2, the following undercoating upper layer coating liquid b-2 is provided on the undercoating layer B-1 to have an antistatic function so that the dry film thickness becomes 0.4 μm. It was applied as B-2.

<< Undercoating Upper Layer Coating Liquid a-2 >> Gelatin 0.4 g / m ² Mass (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles ( Average particle diameter 3 μm) 0.1 g Finish with water to 1 L << Undercoating upper layer coating liquid b-2 >> Sb-doped SnO ₂ (SNS10M; manufactured by Ishihara Sangyo Co., Ltd.) 60 g (C-4) latex Liquid (solid content 20%) 80 g Ammonium sulphate 0.5 g (C-5) 12 g Polyethylene glycol (mass average molecular weight 600) 6 g Finish with water to 1 liter.

[0339]

[Chemical formula 22]

[0340]

[Chemical formula 23]

<< Preparation of Backcoat Layer Coating Liquid >> Cellulose acetate butyrate (Eastman Chemi) was stirred while 830 g of methyl ethyl ketone (MEK) was stirred.
cal., CAB381-20) 84.2 g and polyester resin (Bostic, VitelPE220).
OB) (4.5 g) was added and dissolved. Next, 0.30 g of infrared dye 1 was added to the dissolved liquid, and methanol 4 was added.
4.5 g of F-based surfactant (Asahi Glass Co., Surflon KH40) and 2.3 g of F-based surfactant (Dainippon Ink and Megafag F120K) dissolved in 3.2 g were added,
The solution was sufficiently stirred until it was dissolved. Then 2,5 g of oleyl oleate was added. Finally, silica dispersed in a methyl ethyl ketone at a concentration of 1% by a dissolver type homogenizer (WR Grace, Syroid 64X60).
00) was added and stirred to prepare a coating solution for back coat layer.

[0342]

[Chemical formula 24]

<< Preparation of Backcoat Layer Protective Layer (Surface Protective Layer) Coating Solution >> Cellulose acetate butyrate (10% methyl ethyl ketone solution) 15 g Monodispersity 15% Monodisperse silica (average particle size: 8 μm) 0.030 g (silica Surface treatment with 1% by mass of total mass of aluminum) C ₈ F ₁₇ (CH ₂ CH ₂ O) ₁₂ C ₈ F ₁₇ 0.05 g C ₉ F ₁₇ —C ₆ H ₄ —SO ₃ Na 0.01 g stearic acid 0 0.1 g oleyl oleate 0.1 g The backcoat layer coating liquid and the backcoat layer protective layer coating liquid thus prepared were each dried to a thickness of 3.5 μm.
Application speed 50m / m with an extrusion coater
Coating was performed in. The drying temperature is 100
C. and a dew point temperature of 10.degree. C. was used for 5 minutes.

<< Preparation of Photosensitive Silver Halide Emulsion A >> (A1) Phenylcarbamoylated gelatin 88.3 g Compound (A) (10% aqueous methanol solution) 10 ml Potassium bromide 0.32 g Water to make 5429 ml (B1) 0 67 mol / L aqueous solution of silver nitrate 2635 ml (C1) potassium bromide 51.55 g potassium iodide 1.47 g finished with water to 660 ml (D1) potassium bromide 154.9 g potassium iodide 4.41 g iridium chloride (1% solution) 0 .93 ml Water to make 1982 ml (E1) 0.4 mol / liter potassium bromide aqueous solution Silver potential control amount below (F1) Potassium hydroxide 0.71 g Water to make 20 ml (G1) 56% acetic acid aqueous solution 18.0 ml ( H1) 1.72g anhydrous sodium carbonate Prepare 151ml with water Compound which increases _{(A): HO (CH 2} CH 2 O) n - (CH (CH 3) CH 2 O) 17 - (CH 2 CH 2 O) m H (m + n = 5~7) Japanese Patent Publication No. 58-58288 , Solution (B1) into solution (A1) using the mixing stirrer shown in No. 58-58289.
1/4 amount and the total amount of the solution (C1) at a temperature of 20 ° C. and pAg
While controlling at 8.09, it took 4 minutes and 45 seconds by the simultaneous mixing method to add and perform nucleation. After 1 minute, solution (F1)
Was added. During this period, the pAg was adjusted appropriately by using (E1). After 6 minutes, 3/4 of solution (B1)
Amount and the total amount of the solution (D1) at a temperature of 20 ° C., pAg8.
While controlling at 09, the mixture was added by the simultaneous mixing method over 14 minutes and 15 seconds. After stirring for 5 minutes, the temperature was lowered to 40 ° C., the entire amount of the solution (G1) was added, and the silver halide emulsion was precipitated. The supernatant was removed, leaving 2000 ml of the sedimented portion, 10 liters of water was added, and after stirring, the silver halide emulsion was sedimented again. The supernatant was removed, leaving 1500 ml of the sedimented portion, 10 liters of water was further added, and after stirring,
The silver halide emulsion was allowed to settle. Settling portion 1500 ml
After removing the supernatant liquid, the solution (H1) was added, the temperature was raised to 60 ° C., and the mixture was further stirred for 120 minutes. Finally p
Adjust so that H becomes 5.8, and add 11 for 1 mol of silver.
Water was added so that the amount became 61 g to obtain a photosensitive silver halide emulsion A.

This emulsion was monodisperse cubic silver iodobromide grains having an average grain size of 25 nm, a grain size variation coefficient of 12% and a [100] plane ratio of 92%.

<< Preparation of Light-Sensitive Silver Halide Emulsion B >> The preparation of Light-sensitive Silver Halide Emulsion A was performed except that the temperature at the time of addition was changed to 40 ° C. by the simultaneous mixing method. This emulsion has an average grain size of 50 nm and a grain size variation coefficient of 1
It was a monodisperse cubic silver iodobromide grain having a proportion of 2% and a [100] plane ratio of 92%.

<< Preparation of Powdered Organic Silver Salt A >> 130.8 g of behenic acid and 67.7 of arachidic acid were added to 4720 ml of pure water.
g, stearic acid 43.6 g, and palmitic acid 2.3 g were dissolved at 80 ° C. Next, 540.2 ml of a 1.5 mol / liter sodium hydroxide aqueous solution was added to it to add concentrated nitric acid 6.9.
After adding ml, it cooled at 55 degreeC and obtained the fatty-acid sodium solution. The temperature of the fatty acid sodium solution above 55 ℃
36.2 g of the above photosensitive silver halide emulsion A, 9.1 g of the above photosensitive silver halide emulsion B and 450 ml of pure water were added and stirred for 5 minutes.

Next, a 1 mol / liter silver nitrate solution 70
2.6 ml was added over 2 minutes and stirred for 10 minutes to obtain an organic silver salt dispersion. After that, the obtained organic silver salt dispersion was transferred to a water washing container, deionized water was added thereto, and the mixture was stirred and then allowed to stand to separate the organic silver salt dispersion by flotation to remove the water-soluble salts below. After that, washing with deionized water and drainage were repeated until the conductivity of the drainage reached 2 μS / cm, and centrifugal dehydration was carried out. Then, the cake-shaped organic silver salt obtained was washed with a flash dryer, flash jet dryer (stock). Drying powder organic silver salt A (average particle size (equivalent to yen) using Seisei Enterprise Co., Ltd.) and dried until the water content becomes 0.1% according to the operating conditions of nitrogen gas atmosphere and hot air temperature at the dryer inlet. Diameter) 0.08 μm, aspect ratio 5, monodispersity 10%)
Got

An infrared moisture meter was used to measure the water content of the organic silver salt composition. << Preparation of Preliminary Dispersion A >> As a binder for the image forming layer,
Dissolve the amount shown in Table 1 of Binder 1 shown in Table 1 in 1457 g of methyl ethyl ketone, and gradually add 500 g of powdered organic silver salt A while stirring with a dissolver DISPERMAT CA-40M type manufactured by VMA-GETZMANN and mix them sufficiently. To prepare the pre-dispersion liquid A.

<< Preparation of Photosensitive Emulsion Dispersion Liquid 1 >> Pre-dispersion liquid A was loaded with zirconia beads (Torecelum manufactured by Toray) having a diameter of 0.5 mm so that the residence time in the mill was 1.5 minutes using a pump. Media type disperser D filled with 80% of product
ISPERMAT SL-C12EX type (VMA-GE
TZMANN) and dispersed at a mill peripheral speed of 8 m / s to prepare Photosensitive Emulsion Dispersion Liquid 1.

<< Preparation of Stabilizer Solution >> 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 A >> 19.2 mg
Infrared sensitizing dye, 1.488 g 2-chloro-benzoic acid, 2.779 g Stabilizer 2 and 365 mg 5-methyl-2-mercaptobenzimidazole 31.3 m.
Infrared sensitizing dye solution A was prepared by dissolving 1 l of MEK in the dark.

<< Preparation of Additive Solution a >> 27.98 g of the compound shown in Table 1 as a developer and 1.54 g of 4-methylphthalic acid, 0.48 g of the above infrared dye 1 and 110 g of MEK.
Was dissolved in to prepare an additive solution a.

<< Preparation of Additive Solution b >> 1.56 g of antifoggant 2, 3.43 g of phthalazine was dissolved in 40.9 g of MEK to prepare Additive Solution b.

<< Preparation of Additive Liquid c >> 0.5 g of the vinyl compound A1 represented by the general formula (G) was used as a silver saving agent with MEK.
It was dissolved in 39.5 g to obtain an additive liquid c.

[0356]

[Chemical 25]

<< Preparation of Coating Solution for Image-Forming Layer >> In an inert gas atmosphere (nitrogen 97%), the photosensitive emulsion dispersion 1 (50 g) and MEK (15.11 g) were kept at 21 ° C. with stirring and chemically increased. Sensitizer S-5 (0.5% methanol solution) (1000 μl) was added, and 2 minutes later, antifoggant 1
(10% methanol solution) (390 μl) was added, and the mixture was stirred for 1 hour. Further, 494 μl of calcium bromide (10% methanol solution) was added and stirred for 10 minutes, and then a gold sensitizer Au-5 corresponding to 1/20 mol of the above organic chemical sensitizer was added and further stirred for 20 minutes. . Then, the stabilizer liquid 167
After adding ml and stirring for 10 minutes, 1.32 g of the infrared sensitizing dye solution A was added and stirred for 1 hour. afterwards,
The temperature was lowered to 13 ° C., and the mixture was further stirred for 30 minutes. Thirteen
While keeping the temperature at ℃, add 13.31 g of the binder used in Pre-dispersion A and stir for 30 minutes, then add 1.084 g of tetrachlorophthalic acid (9.4% by mass MEK solution) and stir for 15 minutes. did. While continuing to stir,
12.43 g of additive liquid a, 1.6 ml of Desmodu
rN3300 / Mobey's aliphatic isocyanate (10% MEK solution), 4.27 g of additive liquid b, 4.0
The addition liquid c of g was sequentially added and stirred to obtain a coating liquid for the image forming layer.

[0358]

[Chemical formula 26]

<< Preparation of Image Forming Layer Protective Layer Lower Layer (Surface Protective Layer Lower Layer) >> Acetone 5 g Methyl ethyl ketone 21 g Binder 2 (described in Table 1) 2.3 g Methanol 7 g Phthalazine 0.25 g 1,1-bis (2-hydroxy-) 3,5-Dimethylphenyl) -3,5,5-trimethylhexane (20% methanol solution) 10 g Monodispersity 15% Monodisperse silica (average particle diameter: 3 μm) 0.140 g (1% by mass of silica total mass) Surface treatment with aluminum) CH ₂ = CHSO ₂ CH ₂ CH ₂ OCH ₂ CH ₂ SO ₂ CH = CH ₂ 0.035 g C ₁₂ F ₂₅ (CH ₂ CH ₂ O) ₁₀ C ₁₂ F ₂₅ 0.01 g C ₈ F _{17 -C 6 H 4 -SO 3 Na 0.01g} " preparation of image forming layer upper protective layer (surface protective layer upper layer)" stearate 0.1g butyl stearate 0.1g Cetone 5 g Methyl ethyl ketone 21 g Binder 3 (described in Table 1) 2.3 g Methanol 7 g Phthalazine 0.25 g 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane (20% Methanol solution) 10 g Monodispersity degree 15% Monodisperse silica (average particle size: 3 μm) 0.140 g (surface treatment with 1% by mass of aluminum based on the total mass of silica) CH ₂ = CHSO ₂ CH ₂ CH ₂ OCH ₂ CH ₂ SO _{2 CH = CH 2 0.035g C 12} F 25 (CH 2 CH 2 O) 10 C 12 F 25 0.01g C 8 F 17 -C 6 H 4 -SO 3 Na 0.01g stearate 0.1g stearate Butyl 0.1 g << Image forming layer side coating >> Extrusion of the image forming layer coating liquid and the image forming layer surface protective layer (surface protective layer) coating liquid (Extrude ) Coating speed 50 m / m with a coater
Photosensitive material sample No. 1 to 7 and 13 to 16 (photosensitive material samples No. 15 and 16 are the same as the photosensitive material sample No. 1) were prepared. The coating amount of the image forming layer is 1.2 g of silver.
m ² , the image forming layer protective layer (surface protective layer) was dried to a thickness of 2.5 μm (upper layer 1.3 μm, lower layer 1.2 μm), and then dried at 75 ° C. and dew point temperature at 10 ° C. Drying was performed for 10 minutes using the drying air of.

Example 2 << Preparation of Organic Silver Salt Dispersion >> 7 g of stearic acid, 4 g of arachidic acid, 36 g of behenic acid and 850 ml of distilled water were added at 90 ° C.
1 mol / l NaOH with vigorous stirring
Add 187 ml of an aqueous solution and react for 120 minutes, 1 mol /
After adding 71 ml of nitric acid having a concentration of 1 liter, the temperature was lowered to 50 ° C. Then, 21 g of silver nitrate with more vigorous stirring
125 ml of the above aqueous solution was added over 100 seconds and left as it was for 20 minutes. Then, the solid content was filtered off by suction filtration, and the solid content was washed with water until the conductivity of the filtered water reached 30 μS / cm. 100 g of a 10 mass% aqueous solution of PVA205 (Kuraray Co., Ltd. polyvinyl alcohol) was added to the solid content thus obtained, and water was further added so that the total mass became 270 g, followed by coarse dispersion in an automatic mortar and organic A silver salt crude dispersion was obtained.

The crude dispersion of the organic silver salt was subjected to a pressure at the time of collision of 98.07 mPa using a Nanomizer (manufactured by Nanomizer Co., Ltd.).
To obtain an organic silver salt dispersion. The organic silver salt particles contained in the obtained organic silver salt dispersion have an average short diameter of 0.04 μm,
The acicular particles had an average major axis of 0.8 μm and a coefficient of variation of 30%.

<< Preparation of Reducing Agent (Developer) Dispersion >> 100 g of the developer shown in Table 1 and hydroxypropyl cellulose 5
850 g of water was added to 0 g and mixed well to form a slurry. Prepare 840 g of zirconia beads having an average diameter of 0.5 mm, put them in a vessel together with the slurry, and use a disperser (1
/ 4G Sand Grinder Mill: Imex Corporation
Manufactured) to obtain a reducing agent dispersion.

<< Preparation of Silver Saving Agent Dispersion >> 50 g of the vinyl compound A1 represented by the general formula (G) and 10 g of hydroxypropyl cellulose were mixed with 940 g of water and mixed well to form a slurry. Prepare 840 g of zirconia beads having an average diameter of 0.5 mm, put them in a vessel together with the slurry, and disperse for 5 hours with a disperser (1/4 G sand grinder mill: manufactured by AIMEX Co., Ltd.) to obtain a silver-saving agent dispersion. Obtained. << Preparation of Organic Polyhalide Dispersion >> 940 g of water was added to 50 g (0.127 mol) of tribromomethylphenyl sulfone and 10 g of hydroxypropyl cellulose and mixed well to form a slurry. 840 g of zirconia beads having an average diameter of 0.5 mm was prepared, placed in a vessel together with the slurry, and dispersed for 5 hours with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) to obtain an organic polyhalide dispersion. Obtained.

<< Preparation of Photosensitive Silver Halide Emulsion 1 >> Water 1
After dissolving 22 g of phthalated gelatin and 30 mg of potassium bromide in 000 ml and adjusting the pH to 5.0 at a temperature of 35 ° C., 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 0.9 g of ammonium nitrate, potassium bromide and iodide. 159 m of an aqueous solution containing potassium in a molar ratio of 92: 8
1 was added by the control double jet method over 10 minutes while keeping pAg at 7.7. Then, silver nitrate 5
Aqueous solution 47 containing 5.4 g and 2 g of ammonium nitrate
After adding 6 ml and dipotassium hexachloroiridate to 10 μmol / l and an aqueous solution pAg of 7.7 containing potassium bromide at 1 mol / l, the mixture was added over 10 minutes by the control double jet method, and then 4-hydroxy-6- Methyl-1,3,3a, 7-tetrazaindene 1
g was added, and the pH was further lowered to perform coagulation sedimentation for desalting treatment. Thereafter, 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg to 8.2, and silver iodobromide grains (iodine content core 8 mol%, average 2 mol%, average size 2
5 nm, projected area variation coefficient 8%, (100) plane ratio 85
% Cubic particles).

The silver halide grains thus obtained were heated to 60 ° C. and 85 μmol of sodium thiosulfate and 11 μmol and 15 μm of 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide were added per mol of silver. Molar tellurium compound, chloroauric acid 3 μmol, thiocyanic acid 270 μ
Then, the resulting mixture was ripened for 120 minutes and then rapidly cooled to 40 ° C., then 100 μmol of a sensitizing dye was added, stirred for 30 minutes and then rapidly cooled to 30 ° C. to obtain a photosensitive silver halide emulsion 1. The above-mentioned 30 ° C. is the preparation temperature of the photosensitive silver halide emulsion 1.

[0366]

[Chemical 27]

<< Preparation of Coating Solution for Image Forming Layer >> 1350 g of organic silver salt dispersion, 140% by weight aqueous solution of PVA205 140
ml, 37% of a 10% by mass aqueous solution of phthalazine, 220 g of a reducing agent dispersion, 50 g of a silver saving agent dispersion, and 61 g of the above organic polyhalide dispersion, and then LACSTAR LACSTAR 3307B (Dainippon Ink and Chemicals, Inc. ); SBR latex containing styrene and butadiene as main copolymerization components; average particle diameter of dispersed particles of 0.1 to 0.15 μm, polymer equilibrium water content of 0.6 mass at 25 ° C. and 60% RH. %) 1100 g, and then 120 g of the above photosensitive silver halide emulsion 1
An image forming layer coating liquid was prepared by mixing. The liquid pH should be 1
The pH was adjusted to 5.0 with 1 mol / l sulfuric acid.

<< Preparation of Coating Solution for Image Forming Layer Protective Layer Lower Layer (Surface Protective Layer Lower Layer) >> Water 26 g Binder 2 2.3 g as solid content phthalazine 0.25 g 1,1-bis (2-hydroxy-3,5-dimethyl) Phenyl) -3,5,5-trimethylhexane (20% methanol solution) 10 g Monodispersity 15% Monodisperse silica (average particle size: 3 μm) 0.140 g (surface treatment with 1% by mass of silica total mass of aluminum) _{C 8 F 17 -C 6 H 4} -SO 3 Na 0.02g stearate 0.1g butyl stearate 0.1g alpha-alumina (Mohs hardness 9) 0.1g "imaging layer upper protective layer (surface protective layer upper ) Preparation of coating solution >> Water 26 g Binder 3 (described in Table 1) latex 2.3 g as solid content Phthalazine 0.25 g 1,1-bis (2-hydroxy-3, 5-Dimethylphenyl) -3,5,5-trimethylhexane (20% methanol solution) 10 g Monodispersity 15% Monodisperse silica (average particle size: 3 μm) 0.140 g (with 1% by mass of aluminum based on the total mass of silica) surface _{treatment) C 8 F 17 -C 6 H} 4 -SO 3 Na 0.02g stearate 0.1g butyl stearate 0.1g alpha-alumina (Mohs hardness 9) 0.1g "preparation of back coat layer coating solution" A solid base N,
10 g of a salt of N ′, N ″, N ″ -tetraethylguanidine and 4-carboxymethylsulfonyl-phenyl sulfone in a molar ratio of 1: 2 was added to 10 g of polyvinyl alcohol and 8 parts of water.
8 g and a 1/16 g sand grinder mill (manufactured by IMEX Co., Ltd.) were dispersed to obtain a base solution.

2.1 g of basic dye precursor, acidic substance 7.
9g, 0.1g (1.990 × 10 ^-FourMole)
Anti-prevention dye-1 and 10 g of ethyl acetate mixed and dissolved
Machine solvent phase is polyvinyl alcohol 10g and water 80g
Is mixed with an aqueous solution phase consisting of
Obtained (average particle size 2.5 μm).

39 g of the base solution thus obtained and 26 of the dye solution
g and 36 g of a 10 mass% polyvinyl alcohol aqueous solution were mixed to obtain a coating solution for the back coat layer.

[0371]

[Chemical 28]

<< Preparation of Backcoat Layer Protective Layer (Surface Protective Layer) Coating Solution >> Cellulose acetate butyrate (10% methyl ethyl ketone solution) 15 g Monodispersity 15% Monodisperse silica (average particle size: 8 μm) 0.030 g (silica Surface treatment with 1% by mass of total mass of aluminum) C ₈ F ₁₇ (CH ₂ CH ₂ O) ₁₂ C ₈ F ₁₇ 0.05 g C ₉ F ₁₇ —C ₆ H ₄ —SO ₃ Na 0.01 g stearic acid 0 0.1 g oleyl oleate 0.1 g << Preparation of undercoat coating liquid A >> Polyester copolymer dispersion Pethresin A-515 GB (30%, Takamatsu Yushi Co., Ltd.)
Polystyrene fine particles (average particle size 0.2)
μm) 50 g and surfactant A (1% by mass) 20 ml were added, and distilled water was added to the mixture to make 1000 ml to prepare an undercoat coating liquid A.

[0373]

[Chemical 29]

<< Preparation of Undercoat Coating Solution B >> Distilled water 680 m
200 ml of styrene-butadiene copolymer aqueous dispersion (styrene / butadiene / itaconic acid = 47/50/3 (mass ratio), concentration 30 mass%), and polystyrene fine particles (average particle size 2.5 μm) 0.1 g were added to 1 l. Then, distilled water was further added to 1000 ml to prepare an undercoat coating liquid B.

<< Preparation of Undercoat Coating Liquid C >> 10 g of inert gelatin was dissolved in 500 ml of distilled water, and the solution was added thereto.
40 g of an aqueous dispersion (40% by mass) of tin oxide-antimony oxide composite fine particles described in No. 1-20033 was added,
Distilled water is added to this to make 1000 ml, and undercoating liquid C
And

<< Preparation of undercoated support >> One side (photosensitive surface) of a 175 μm thick biaxially stretched polyethylene terephthalate support tinted with the blue dye used in Example 1 was subjected to corona discharge treatment, The undercoat coating liquid A was coated using a bar coater so that the wet coating amount was 5 ml / m ² and dried at 180 ° C. for 5 minutes. The dry film thickness was about 0.3 μm. Next, this back surface (back surface) is subjected to corona discharge treatment, and then the undercoat coating solution B is applied using a bar coater to a wet coating amount of 5 ml / m ² and a dry film thickness of about 0.3 μm. After drying at 180 ° C. for 5 minutes, the undercoat coating solution C was further coated thereon with a bar coater so that the wet coating amount was 3 ml / m ² and the dry film thickness was about 0.03 μm. After drying for a minute, an undercoated support was prepared.

<< Preparation of Photothermographic Material >> A backcoat layer coating solution having an optical density of 0.8 at 810 nm is provided on the back surface of the undercoated support opposite to the surface (photosensitive surface) on which the image forming layer is applied. At a flow rate of 50 g / m ² for the backcoat layer and the protective layer coating solution. Kistle
r, Peter M. "LIQ" by Schweizer
UID FILM COATING "(CHAPMAN
&Amp; HALL, 1997, 427, Fi
uree 11b. Simultaneous multi-layer coating with the same coater as that of No. 1 and then, from the support side to the surface opposite to the back surface, the image forming layer coating liquid 82 ml / m ² , the image forming layer surface protective layer 40 ml /
Simultaneous multi-layer coating at a coating speed of 160 m / min to obtain m ² and passing through a chilled zone at 10 ° C (dew point 0 ° C or less), followed by drying at 30 ° C, 40% RH, wind speed of 20 m / sec, and further The photosensitive material sample No. 1 shown in Table 1 was subjected to heat treatment at 60 ° C. for 1 minute. 8-12 were obtained. Smoothness of the light-sensitive material thus obtained (J. TAPPI paper pulp test method N
o. The Beck's smoothness was examined using the Oken type smoothness measurement described in 5) was 590 seconds on the image forming layer side and 80 seconds on the backcoat layer side.

<< Exposure and Development Treatment >> Sample No. of the photothermographic material prepared as described above. Half cut size 1 to 14 ((14 x 2.54) cm x (17 x 2.54) cm)
After being processed into a sheet, it was processed in the following manner using the heat development processing apparatus shown in FIG. In addition, the photothermographic material sample Nos. Nos. 15 and 16 are heat-developable photosensitive material sample numbers. 1 was used. Further, the glass transition temperature (Tg) of the protective layer forming film was measured using a film physically separated after film formation and using a differential scanning calorimeter, and the results are shown in Table 2.

After taking out the photothermographic material from the film tray and transporting it to the laser exposure section, from the image forming layer side, a longitudinal multimode semiconductor laser with a wavelength of 810 nm (maximum output of 35 mW per line was obtained by high frequency superposition. Exposure by laser scanning was performed by an exposure machine using two multiplexed light beams having a maximum output of 70 mW) as an exposure source. At this time,
An image was formed by setting the angle between the exposed surface of the photothermographic material and the exposure laser beam at 75 degrees. Then, the photothermographic material was conveyed to the photothermographic section, and the heat drum was heat-developed at 125 ° C. for 15 seconds so that the protective layer on the image forming layer side of the photothermographic material was in contact with the drum surface. After that, the photothermographic material was carried out of the apparatus. At this time, the transport speed from the photosensitive material supply unit to the image exposure unit, the transport speed at the image exposure unit,
The transport speed in the heat developing section was the speed shown in Table 2. The exposure and development were performed in a room where the humidity was adjusted to 23 ° C. and 50% RH.

<Image Density> The value of the highest density portion of the image obtained under the above conditions is measured by a densitometer (image density 1) and shown as image density.

<< Image Density Change with Time Before Thermal Development >>
The obtained light-sensitive material was stored under a humidity condition of 45 ° C. and 80% RH for 3 days, and then exposed and developed in the same manner as above, and the image density (image density 2) of the obtained sample was measured. The difference from the density (image density 1) ((image density 1)-(image density 2)) was determined and shown as the change in image density over time before the heat development treatment.

<< Light Irradiated Image Storability >> The obtained light-sensitive material was exposed and developed in the same manner as above, and then, after sticking on a Schaukasten having a brightness of 1000 lux and left for 10 days, the change in the image was visually observed as follows. It evaluated by the standard of.

[0383] 5: Almost no change 4: Slight change in color tone 3: Some changes in color tone and increased fog 2: Significant changes in color tone and increased fog are observed 1: Significant change in color tone and increase in fog.

<< Powder Removal During Thermal Development >> The powder removal during development was visually evaluated according to the following criteria.

[0385] 5: No occurrence of powder falling 4: A slight powder drop occurred 3: Partially weak powder drop occurred 2: Strong powder drop occurs in some areas 1: Strong powder drop occurred on the entire surface.

<Density unevenness during heat development> The density unevenness after development was visually evaluated according to the following criteria.

[0387] 5: No uneven density is observed 4: Slight uneven density occurs 3: Weak density unevenness occurs in some areas 2: Strong uneven density occurs in some areas 1: Strong uneven density occurs on the entire surface.

<< Roller Mark During Thermal Development >> Occurrence of roller marks after development was visually evaluated on a scale of 5 to 5.

[0389] 5: No occurrence of roller marks 4: Slight roller mark is generated 3: A weak roller mark is generated on a part of the film 2: Strong roller mark is generated on a part of the film 1: Roller marks are generated on the entire surface of the film.

The results are shown in Table 3.

[0391]

[Table 1]

[0390]

[Table 2]

(Binder) A: -SO ₃ Na-containing acrylic resin (phenyl methacrylate / 4-hydroxyphenyl methacrylamide / 3
- acrylic resin is a cyanophenyl methacrylamide = 3/4/3 (weight ratio): Tg = 105 ℃) B : -SO 3 Na -containing acrylic resin (benzyl methacrylate / 4-hydroxyphenyl methacrylamide / 3
- cyanophenyl methacrylamide = 3/4/3 (weight ratio) at which the acrylic resin: Tg = 90 ℃) C: -SO 3 Na -containing acrylic resin (benzyl methacrylate / 4-hydroxyphenyl methacrylamide / methyl methacrylate = 3 / 4/3 (mass ratio) acrylic resin: Tg = 87 ° C.) D: -SO ₃ Na-containing acrylic resin (2-hydroxyethyl methacrylate / methyl methacrylate = 25/7)
5 (mass ratio): Tg = 68 ° C.) E: -SO ₃ Na-containing acrylic resin (ethyl acrylate / methyl methacrylate = 25/75 (mass ratio): T
g = 58 ° C.) Tg: Value obtained by differential scanning calorimetry (DSC).

F: --SO ₃ K group-containing polyvinyl butyral resin (Tg = 75 ° C., --SO ₃ K 0.2 mmol /
(including g)

[0395]

[Table 3]

From Tables 1 to 3, as compared with the comparative light-sensitive material,
The light-sensitive material of the present invention has a high density, has a small density decrease with time before heat development processing, is excellent in light-irradiated image storability, has a small density decrease with time after heat development processing, and is processed by a heat development processor It is clear that the photothermographic material has improved powder removal, density unevenness, and roller mark generation.

[0397]

EFFECTS OF THE INVENTION According to the present invention, it is possible to improve the density of the heat-developable light-sensitive material with a small density change over time, and to improve the generation of powder drop, density unevenness and roller mark when processed by a heat development processor. A development photosensitive material, an image forming method using the photothermographic material, and an image recording method can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a specific example of a heat development processing apparatus.

[Explanation of symbols] 1 heat drum 2 Opposing roller 6 peeling nail 100 heat development device 110 Feeding department 120 exposure section 130 Development Department 140 Supply roller pair 141, 142, 143, 145 Conveying roller pairs 144 Supply roller pair 150 cooling unit 160 stacking unit F film C film tray L laser beam

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03C 1/76 351 G03C 1/76 351 5/08 351 5/08 351

Claims (15)

[Claims] 1. A photothermographic material having an image forming layer containing organic silver, silver halide, a binder and a reducing agent on a support, and the binder contained in the image forming layer and the image forming layer being adjacent to each other. The photothermographic material wherein the binder contained in the layer contains a common monomer component (hereinafter referred to as monomer component A) and satisfies the following formula 1. Formula 1 0.1 ≦ M1 × M2 ≦ 0.95 [wherein, M1 is (mass of monomer component A contained in image forming layer) / (mass of binder contained in image forming layer), and M2 is , (Mass of monomer component A contained in the layer adjacent to the image forming layer) / (mass of binder contained in the layer adjacent to the image forming layer). ] 2. The photothermographic material according to claim 1, wherein the layer adjacent to the image forming layer is an image forming layer protective layer. 3. The photothermographic material according to claim 2, wherein the protective layer for the image forming layer comprises at least two layers. 4. The glass transition temperature of the film forming the outermost layer of the image forming layer protective layer is 5 ° C. to 50 ° C. higher than the glass transition temperature of the film forming film of the lower image forming layer protective layer. 4. The photothermographic material according to claim 3. 5. The bisphenol derivative represented by the following general formula (A) is used as the reducing agent.
5. The photothermographic material according to any one of 4 to 4. [Chemical 1] [In the formula, X represents a chalcogen atom or CHR, and R represents a hydrogen atom, a halogen atom, an aliphatic group having 7 or less carbon atoms, or a cyclic group having 6 or less member rings. R'and R "represent a hydrogen atom or a substituent.] 6. The layer on the side having an image forming layer contains at least one silver saving agent selected from vinyl compounds, hydrazine derivatives and quaternary onium salts. 2. The photothermographic material according to item 1. 7. A silver halide containing an average grain size of 10 nm to 35 nm.
7. The photothermographic material according to any one of 1 to 6. 8. A silver halide having an average grain size of 10 nm to 35 nm and an average grain size of 45 nm to 100.
7. The photothermographic material according to claim 1, which contains a silver halide having a wavelength of nm. 9. A silver halide containing chemically sensitized with a chalcogen compound.
9. The photothermographic material according to any one of to 8. 10. The amount of silver contained in the image forming layer is 0.
The photothermographic material according to any one of claims 1 to 9, characterized in that a ^{3g / m 2 ~1.5g / m 2} . 11. A heat-developable photosensitive material according to any one of claims 1 to 10 is used, wherein a heat-development processing apparatus using a heat drum is used, and a conveyance speed of a heat-development section is 20 mm / sec.
An image forming method characterized by performing heat development at 200 mm / sec. 12. A conveyance speed of the photothermographic material according to claim 1 from a photosensitive material supply section to an image exposure section in a heat development processing apparatus is 20 mm / sec.
An image forming method, wherein the image forming method is about 200 mm / sec. 13. A conveyance speed of the photothermographic material according to claim 1 at an image exposure unit in a heat development processing apparatus is 20 mm / sec to 200 mm / sec.
An image forming method comprising: 14. Scan exposure of the photothermographic material according to claim 1 with a laser beam in which the angle between the exposure surface and the laser beam is not substantially perpendicular. An image recording method characterized by. 15. An image recording method, wherein the photothermographic material according to claim 1 is scanned and exposed using vertical multi-laser light having an exposure wavelength which is not single.