JP2003043627A - Thermally developable photosensitive material and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally developable photosensitive material having excellent conveyability in a plotter and a thermal developing machine. SOLUTION: The thermally developable photosensitive material has an imaging layer containing an organic silver salt, photosensitive silver halide, a reducer and a contrast enhancer and a back layer on a transparent support and the Bekk smoothness of the back layer side is 50-2,000's.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photothermographic material and an image forming method thereof. In particular, the present invention relates to an image forming method for a photothermographic material suitable for photolithography for an image setter. It relates to a photothermographic material which is difficult to develop.

[0002]

2. Description of the Related Art In the field of conventional printing plate making, a waste liquid caused by wet processing of image forming materials has been a problem in terms of workability. Strongly desired. Therefore, a technique relating to a photothermographic material, which enables efficient exposure by a laser imagesetter and can form a clear black image with high resolution, has been attracting attention.

As this technique, for example, US Pat.
152,904, 3,487,075 and D.I. "Dry Silver Photographic Material" by Morgan
s) ”(Handbook of Imaging Materials, MarcelDekke
r, Inc., p. 48, 1991) and the like, a photothermographic material containing an organic silver salt, a photosensitive silver halide grain, a reducing agent and a binder on a support is known. .

For printing photomechanical applications, there is a need for a light-sensitive material which is substantially colorless (especially colorless in the UV region) and which provides hard photographic characteristics. In the case of photosensitive materials that are premised on infrared exposure, the visible absorption of sensitizing dyes and antihalation dyes can be greatly reduced, making it possible to easily produce photosensitive materials that are virtually free of color. The technology of silver photographic materials was developed. Regarding the spectral sensitization technique, Japanese Examined Patent Publication No. 3-10391, Japanese Examined Patent Publication No. 6-52
No. 387, Japanese Unexamined Patent Publication No. 5-341432, Japanese Unexamined Patent Publication No. 6-194781, Japanese Unexamined Patent Publication No. 6-301141, etc. Further, regarding halation prevention technology, Japanese Unexamined Patent Publication No. 7-13295, U.S. Pat. 53rd
No. 80635. In addition, as a method for obtaining a hard photographic property, European Patent Publication EP762,1
96A, JP-A-9-90550, and the like, a photosensitive silver halide grain used in a photothermographic material containing a Group VII or VIII metal ion or a metal complex ion, and a photothermographic material. It is disclosed that a hydrazine derivative can be contained therein to obtain a hard photographic property.

In recent years, digitization in the entire printing process,
The automation of work has become widespread, and CTF (Computer To Film) that collects digital information directly on a film by performing plate collection (DTP: Desk Top Publishing) on a computer is becoming mainstream for photolithography. There is. That is, the photothermographic material is set in a roll form on a plotter section of a system in which a plotter and a heat developing machine are integrated, and is exposed and processed based on information transmitted from a computer. Due to the online output, the transportability of the photothermographic material in the plotter and the heat developing machine has become more important than before. Therefore, it has been desired to develop a light-sensitive material having no problem in transportability in a plotter and a thermal processor.

[0006]

Therefore, the problem to be solved by the present invention is to provide a photothermographic material excellent in transportability in a plotter and a heat processor for photolithography, especially for scanners and imagesetters. It is to provide the image forming method.

[0007]

As a result of intensive studies to solve the above problems, it was found that an excellent photothermographic material can be obtained by controlling the Bekk smoothness on the back layer side. It came to offer. That is, the present invention has an image forming layer containing an organic silver salt, a photosensitive silver halide, a reducing agent, a contrast adjusting agent and a back layer on a transparent support, and the Beck smoothness on the back layer side is 50 seconds to 2000
Provided is a photothermographic material, which is characterized in that it has a period of seconds, preferably 130 seconds to 1000 seconds. The Beck smoothness on the image forming layer side of the photothermographic material of the present invention is preferably 1000 seconds or more. The matting agent contained in the back layer has a monodispersity of 3% to 30% and an average particle size of 3 μm.
It is preferable that the silica particles have a particle size of ˜15 μm, and the binder on the side of the back layer is a cellulose derivative, especially cellulose acetate butyrate. The transparent support is preferably heat treated. The photothermographic material of the invention is preferably in the form of a roll wound with the image forming layer side facing outward.

The present invention also relates to a plotter; a preheating section,
Heat developing machine equipped with heat developing section, slow cooling section and deodorizing device;
And heat development from plotter by connecting plotter and heat processor
From the auto carrier that automatically conveys the photothermographic material to the machine
And the processing speed of the heat developing section of the heat developing machine is 25 m
With an online system of m / sec to 50 mm / sec
Image formation by exposing and developing the above photothermographic material
It also provides a method. In the image forming method of the present invention, the on
Line system auto carrier processing speed (t ₁),
Processing speed (t₂) And heat development
Processing speed (t₃) Satisfies the relation
The case is preferred. t₃ > T₂ ≧ t₁ Furthermore, the exposure light source of the plotter has a wavelength of 750 to 800.
nm laser, main scanning on the surface of photothermographic material
It is preferable that the speed is 500 m / sec to 1500 m / sec.
Good

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The photothermographic material of the present invention and the image forming method thereof will be described in detail below. In addition, in this specification, "-" is used to mean that the numerical values described before and after the "-" are included as the minimum value and the maximum value, respectively. The photothermographic material of the present invention has an image forming layer containing an organic silver salt, a photosensitive silver halide, a reducing agent and a contrast adjusting agent, and a back layer on a transparent support. The Beck's smoothness is 50 seconds to 2000 seconds.

The term "Beck smoothness" as used herein means
It represents the degree of matteness, so-called "surface roughness". Here, the surface roughness is the roughness due to the unevenness of the surface that occurs at small intervals, and is the basis of the sensation that is usually perceived as "smooth" or "rough". There are various methods of measuring the matte degree, and there are surface morphological observations using a surface roughness meter, an optical microscope, a scanning electron microscope, etc., but the average surface roughness is JISP.
The Beck smoothness described in 8119 can be mentioned. Beck smoothness can be expressed with the number of seconds to flow of air 10ml under approximately 370mmHg pressure difference when pressed against the surface to be measured of the flat plate of the effective area 10 cm ² at a pressure of 1 kg / cm ^2. That is, the larger the number of seconds, the smaller the matte degree, and the smaller the number of seconds, the larger the matte degree. Further, in order to measure Beck's smoothness with high accuracy, it is preferable to use an air micrometer type tester. TAP
PI paper pulp test method No. Beck smoothness with good reproducibility can be easily obtained by using the Oken type smoothness measurement described in 5 (Yamamoto et al., Paper and Paper Cooperative Journal, 20 [2], 17-24.
(1966)).

Regarding the transportability in the plotter and the heat developing machine at the time of exposure, the Bekk smoothness on the back layer side is 50 seconds to 200.
Good results are obtained in 0 seconds, more preferably 130
Seconds to 1000 seconds, more preferably 200 seconds to 9 seconds
00 seconds. Usually, a matting agent is used to impart a matting degree to the light-sensitive material. Matting agents are generally fine particles of water-insoluble organic or inorganic compounds. Any matting agent can be used. For example, US Pat.
939,213, 2,701,245, 2,322,037, 3,262,7
No. 82, No. 3,539,344, No. 3,
Organic matting agents described in US Pat. No. 767,448, US Pat. Nos. 1,260,772 and 2,192,2.
No. 41, No. 3,257,206, No. 3,
Inorganic matting agents well known in the art such as those described in 370,951, 3,523,022 and 3,769,020 can be used. For example, specifically as an example of an organic compound that can be used as a matting agent, as an example of a water-dispersible vinyl polymer, polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, acrylonitrile-α-
Methyl styrene copolymer, polystyrene, styrene-divinylbenzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc., examples of cellulose derivatives include methyl cellulose,
Examples of starch derivatives such as cellulose acetate, cellulose acetate propionate, carboxy starch, carboxynitrophenyl starch, urea-formaldehyde-starch reaction products, etc., gelatin and coacervate hardened by known hardening agents, and microcapsule hollow particles The hardened gelatin described above can be preferably used. As examples of inorganic compounds, silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, diatomaceous earth and the like can be preferably used. A particularly preferred matting agent is silica particles (silicon dioxide).

The particle size distribution of the matting agent may be narrow or wide, but it is preferably monodisperse. Monodispersity is the same as the definition of monodispersity of photosensitive silver halide described below,
3% to 30% is preferable, and 3% to 18% is more preferable.
Is. The above matting agents can be used by mixing different kinds of substances as necessary. Size of matting agent,
The shape is not particularly limited, and those having an arbitrary particle size can be used, but in the practice of the present invention, 3 μm to 15 μm
It is preferable to use one having a particle size Since the matting agent has a great influence on the haze and surface gloss of the light-sensitive material, it is preferable that the particle size, shape and particle size distribution are adjusted to a necessary state at the time of preparing the matting agent or by mixing a plurality of matting agents.

In the present invention, the matting agent is preferably contained in the outermost surface layer of the light-sensitive material, a layer functioning as the outermost surface layer, or a layer close to the outer surface, and also in a layer acting as a so-called protective layer. It is preferably contained. The matting degree can be controlled by changing the matting agent particle size / adding amount. By increasing the particle size of the matting agent or increasing the amount of the matting agent added, the matting degree becomes a small value. In particular, increasing the particle size of the matting agent is effective in reducing the matting degree.

In the present invention, the Beck smoothness on the image forming layer side is not particularly limited, but it is preferably 1000 seconds or more.

The photothermographic material of the present invention is usually 750 to 750.
It is exposed with light having a wavelength of 800 nm. As the plotter used for exposure, a plotter using a laser diode (LD) capable of exposure with an exposure time of 10 ⁻⁷ seconds or less as a light source is usually used. Any of these light sources may be used as long as it can generate light having an electromagnetic wave spectrum in a target wavelength range. For example, a dye laser, a gas laser, a solid-state laser, a semiconductor laser and the like can be used, but the semiconductor laser is particularly preferably used from the viewpoint of space saving and cost saving.

In the present invention, it is preferable that the light beams are overlapped during the exposure. The overlap means that the sub-scanning pitch width is smaller than the beam diameter. The overlap can be quantitatively expressed by FWHM / sub-scanning pitch width (overlap coefficient) when the beam diameter is expressed by the full width at half maximum (FWHM) of the beam intensity. In the present invention, this overlap coefficient is preferably 0.2 or more.

The scanning method of the light source of the plotter used in the present invention is not particularly limited, and a cylinder outer surface scanning method, a cylinder inner surface scanning method, a flat surface scanning method or the like can be used. Further, the channel of the light source may be a single channel or a multi-channel, but a multi-channel in which two or more laser heads are mounted is preferable in that high output can be obtained and writing time can be shortened. Particularly, in the case of the cylindrical outer surface type, a multi-channel in which several to several tens or more laser heads are mounted is preferably used.

The scanning system of the light source of the plotter preferably used in the present invention is the inner drum system (cylindrical inner surface scanning system). The exposure is performed by scanning the laser light generated from the laser diode through the polygon mirror (prism) onto the surface of the photothermographic material conveyed to the inner drum portion. The exposure time in the main scanning direction is determined by the rotation speed of the polygon mirror and the inner diameter of the drum. The main scanning speed on the surface of the photothermographic material of the present invention is preferably 500 m / sec to 1500 m / sec. A more preferable main scanning speed is 1100 m / sec to 1500 m / sec.

When the photothermographic material to be exposed has a low haze at the time of exposure, interference fringes tend to occur, so it is preferable to prevent this. As a technique for preventing the generation of interference fringes, a technique disclosed in JP-A-5-113548 and the like, in which laser light is obliquely incident on a photosensitive material, and International Publication WO95 / 317.
Methods utilizing a multi-mode laser disclosed in Japanese Patent Publication No. 54, etc. are known, and it is preferable to use these techniques.

The photothermographic material of the present invention is exposed to light to form a latent image, and then developed by a heat developing machine having a preheating section, a heat developing section and a slow cooling section. The development temperature by the heat developing machine is preferably 80 to 250 ° C., and 100
It is preferably ˜140 ° C. The total developing time by the heat developing machine is preferably 1 to 180 seconds,
More preferably, it is 5 to 90 seconds. Further, the processing speed of the heat developing section by the heat developing machine is 21 to 100 mm /
Seconds are preferred, and 27-50 mm / s are more preferred.

The exposed photothermographic material is first heated in the preheating section. The preheating section is provided for the purpose of preventing uneven processing due to dimensional change of the photothermographic material during heat development. The heating in the preheating section is lower than the heat development temperature (for example, about 10 to 30 ° C. lower), and it is desirable to set the temperature and time sufficient to evaporate the solvent remaining in the photothermographic material. At a temperature higher than the glass transition temperature (Tg) of the support of the photosensitive material,
It is preferable to set so that development unevenness does not occur. Generally, it is preferable to heat at 80 ° C. or higher and lower than 115 ° C. for 5 seconds or longer.

The photothermographic material which has been heated in the preheating section is subsequently heated in the heat developing section. In the image forming method of the present invention, the heat developing section is provided with a heating member on the image forming layer side and the back layer side with respect to the conveyed photothermographic material, and is also provided with a conveying roller only on the image forming layer side. . For example, when the photothermographic material is conveyed with the image forming layer on the upper side, there is no conveyance roller on the lower side (back layer side of the photothermographic material) with respect to the conveying direction of the photothermographic material, and the upper side (heat development The transport roller is provided only on the image forming layer side of the photosensitive material. In the present invention, the heat developing section is configured as described above to prevent density unevenness and physical deformation.

In the heat developing section, the photothermographic material is heated by a heating member such as a heater. The heating temperature in the heat development section is a temperature sufficient for heat development, and is generally 110 ° C to 140 ° C. Since the photothermographic material is exposed to a high temperature of 110 ° C. or higher in the heat development section,
Part of the components contained in the material or part of the decomposed components by heat development may volatilize. These volatile components cause uneven development, corrode the components of the thermal processor, deposit in low temperature places, causing the screen to deform as foreign matter, and stains on the screen. , Etc. are known to have various adverse effects. As a method for eliminating these influences, a method is known in which a filter is installed in the heat developing machine and the air flow in the heat developing machine is optimally adjusted. These methods can be effectively used in combination. For example, in International Publication Nos. WO95 / 30933, 97/21150, and Japanese Patent Publication No. 10-500946, there is a first opening having bound absorbent particles for introducing volatile matter and a second opening for discharging volatile matter. It is described that a filter cartridge having an opening is used for a heating device that contacts a film to heat it. In addition, International Publication WO96 / 12213 and Japanese Patent Publication No. 10-507403 describe the use of a filter in which a heat conductive condensing collector and a gas absorbing fine particle filter are combined. In the present invention, these can be preferably used. Further, in U.S. Pat. No. 4,518,845 and Japanese Patent Publication No. 3-54331, a device for removing vapor from a film, a pressure device for pressing the film against the heat transfer member, and a heat transfer member are heated. And a device for doing so. In addition, International Publication WO98 / 27458 discloses that a component that increases volatilization fog from a film is removed from the film surface. These can also be preferably used in the present invention.

The temperature distribution of heating in the preheating section and the heat developing section is preferably ± 1 ° C. or less,
It is more preferably 0.5 ° C. or lower.

The photothermographic material heated in the photothermographic section is
Next, it is cooled in the slow cooling part. Cooling is preferably performed gradually so that the photothermographic material is not physically deformed,
The cooling rate is preferably 0.5 to 10 ° C / sec.

FIG. 1 shows an example of the structure of a thermal developing machine used in the image forming method of the present invention. FIG. 1 is a schematic side view of the heat developing machine. The heat developing machine shown in FIG. 1 comprises a preheating section A for preheating the photothermographic material 10, a heat developing section B for heat developing processing, and a slow cooling section C for cooling the photothermographic material. To be done. The preheating unit A includes a pair of carry-in rollers 11 (the upper roller is a silicon rubber roller,
The lower roller has a heat roller made of aluminum). The heat developing section B is provided with a plurality of rollers 13 on the side in contact with the surface of the photothermographic material 10 on which the image forming layer is formed, and the surface on the back layer side of the photothermographic material 10 on the opposite side. A smooth surface 1 on which a non-woven fabric (made of, for example, aromatic polyamide or Teflon (registered trademark)) is attached to the side that comes into contact with
4 is provided. The clearance between the roller 13 and the smooth surface 14 is appropriately adjusted so that the photothermographic material 10 can be conveyed. Generally, clearance is 0 to 1 mm
It is a degree. Further, the heat developing section B is provided with a heater 15 (a plate-shaped heater or the like) for heating the photothermographic material 10 from the image forming layer side and the back layer side, above the roller 13 and below the smooth surface 14. . The slow cooling section C includes a carry-out roller pair 12 for carrying out the photothermographic material 10 from the heat developing section B and a guide plate 16.

The photothermographic material 10 is thermally developed while being conveyed from the carry-in roller pair 11 to the carry-out roller pair 12.
The photothermographic material 10 is exposed and then carried into the preheating section B. In the preheating section B, the photothermographic material 10
Is corrected into a flat shape by a plurality of carrying-in roller pairs 12, preheated, and carried into the thermal developing section B. The photothermographic material 10 carried into the photothermographic section B is inserted into the clearance between the plurality of rollers 13 and the smooth surface 14, and is driven by the rollers 13 that come into contact with the surface of the photothermographic material 10 to move to the back layer side. It is transported while sliding its surface on the smooth surface 14. While being conveyed, the photothermographic material 10 is heated by the heater 1 from both the image forming layer side and the back layer side.
5 is heated to a temperature sufficient for heat development, and the latent image formed by exposure is developed. After that, the photothermographic material 10 is conveyed to the slow cooling section C, is straightened by the pair of unloading rollers 12, and is unloaded from the heat developing machine.

The material of the surface of the roller 13 of the heat developing section B and the member of the smooth surface 14 have high temperature durability and are not particularly limited as long as they do not hinder the conveyance of the photothermographic material 10, but the surface of the roller 13 is not limited. The material of is preferably silicon rubber, and the member of the smooth surface 14 is preferably a nonwoven fabric made of aromatic polyamide or Teflon (PTFE). The heater 15 is not particularly limited in shape and number as long as it can heat the photothermographic material 10 to a temperature sufficient for thermal development, but the heating temperature of each can be freely set. Preferably.

The photothermographic material 10 is heated by a preheating section A having a carry-in roller pair 11 and a heat developing section B having a heater 15. The preheating section A is heated at a heat development temperature. The glass transition temperature of the support of the photothermographic material 10 is preferably set to a temperature and time lower than the above (for example, about 10 to 30 ° C. lower) and sufficient to evaporate the solvent in the photothermographic material 10. It is preferable to set the temperature higher than (Tg) so as not to cause uneven development. The temperature distribution between the preheating section and the heat development section is ±
It is preferably 1 ° C or lower, more preferably ± 0.5 ° C or lower.

In order to prevent the photothermographic material 10 from being rapidly cooled and deformed in the slow cooling section C, the guide plate 16 is preferably made of a material having a low thermal conductivity.

The photothermographic material of the present invention comprises a plotter,
Exposure and heat development are preferably carried out by an online system of an auto carrier and a heat processor. The auto carrier is for automatically carrying the exposed photothermographic material to the heat developing machine, and the carrying mechanism may be any system such as a belt conveyer or roller conveyer, but roller conveyer is preferable.
Further, the auto carrier is preferably provided with a mechanism so that heat does not enter from the heat developing machine side to the plotter side,
For example, there is a method in which air is blown into the plotter and the thermal processor from the lower center of the auto carrier.

The linear velocity ratio between the preheating section and the heat developing section is 9
It is preferable to perform development under the condition of 5.0 to 99.0%, and the linear velocity ratio between the auto carrier and the preheating section is 9%.
It is preferable to perform development processing under the condition of 0.0 to 100%. The linear velocity ratio between the preheating section and the thermal development section is 95.0%.
If the linear velocity ratio between the auto carrier and the preheating section is less than 90.0%, scratches and jamming may occur, resulting in poor transportability and uneven density. Tend.

The photothermographic material of the present invention has, for example, a width of 5
A sheet-like member having a length of 50 to 650 mm and a length of 1 to 65 m is used, and a part or all of the sheet-like member is wound into a cylindrical core member with the image forming layer as the outer side and incorporated in a heat developing system.

The organic silver salt used in the photothermographic material of the invention is a reducible silver source, and silver salts of organic acids and heteroorganic acids containing a reducible silver ion source, particularly long-chain (10
.About.30, preferably 15 to 25 carbon atoms) aliphatic carboxylic acids and nitrogen-containing heterocycles are preferred. The ligand is
Organic or inorganic silver salt complexes having a total stability constant for silver ions of 4.0 to 10.0 are also useful. Examples of suitable silver salts are described in Research Disclosure (hereinafter referred to as RD) Nos. 17029 and 29963, and include the following.

Salts of organic acids (eg, gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid, etc.); silver carboxyalkylthiourea salts (eg, 1- (3-carboxy) Propyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); a silver complex of a polymer reaction product of an aldehyde and a hydroxy-substituted aromatic carboxylic acid (for example, aldehydes (formaldehyde, acetaldehyde, Butyraldehyde etc.), hydroxy-substituted acids (eg salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid)), silver salts or complexes of thiones (eg 3- (2-carboxyl). Ethyl)-
4-hydroxymethyl-4- (thiazolin-2-thione), and 3-carboxymethyl-4-thiazoline-
2-thione), imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole and benzotriazole, with a nitric acid and silver. Complexes or salts; silver salts such as saccharin, 5-chlorosalicylaldoxime; and silver salts of mercaptides. Of these, the preferred silver source is silver behenate, arachidic acid and / or stearic acid.

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 and the like as described in Japanese Patent No. 3 are preferably used. For example, after adding alkali metal salt (eg sodium hydroxide, potassium hydroxide) to organic acid to make organic acid alkali metal salt soap (eg sodium behenate, sodium arachidate), controlled double jet Thus, the soap and silver nitrate can be added to produce an organic silver salt crystal. At that time, silver halide grains may be mixed.

In the present invention, the organic silver salt has an average particle size of 2 μm.
It is preferably m or less and monodisperse. The monodisperse as used herein is obtained by the same formula as that of silver halide described later, and in organic silver, monodisperse has the same meaning as in the case of silver halide, and in the case of organic silver, the dispersity is 50%.
Says: It is more preferably 40% or less, and particularly preferably 0.1% to 30%. The average particle size of the organic silver salt refers to the diameter when considering the sphere equivalent to the volume of the organic silver salt particle when the organic silver salt particle is, for example, spherical, rod-shaped, or tabular particle. . The average particle size is preferably 0.05 to 1.5 μm, particularly 0.05 to 1.0
μm is preferred. Further, in the organic silver salt of the present invention, it is preferable that 60% or more of all the organic silver salts are tabular grains. In the present invention, the tabular grains mean those having a ratio of average grain size to thickness, that is, an aspect ratio (abbreviated as AR) represented by the following formula of 3 or more. AR = average particle size (μm) / thickness (μm)

In order to form the organic silver salt into these forms,
It can be obtained by dispersing and pulverizing the organic silver crystal together with a binder, a surfactant and the like in a ball mill or the like. Within this range, a light-sensitive material having high density and excellent image storability can be obtained.

In the present invention, in order to prevent devitrification of the light-sensitive material, the total amount of silver halide and organic silver salt is preferably 0.5 g to 2.2 g per m ² in terms of silver amount. Within this range, a high contrast image can be obtained.
Also, the amount of silver halide is 50% by mass relative to the total amount of silver.
Or less, preferably 25% or less, more preferably 0.1
Between ~ 15%.

Next, the contrast enhancer used in the present invention will be described. The type of the contrast-increasing agent used in the present invention is not particularly limited.
-284399, hydrazine derivatives represented by formula (H) (specifically, hydrazine derivatives described in Tables 1 to 4 of the publication), JP-A-10-10672,
JP-A-10-161270 and JP-A-10-628.
98, JP-A-9-304870, JP-A-9
-304872, JP 9-304871, JP 10-31282, and US Pat. No. 5,4.
96,695, European Patent Publication EP 741,32
Mention may be made of all the hydrazine derivatives described in 0A. Further, it is a substituted alkene derivative represented by Formulas (1) to (3) described in JP-A 2000-284399, a substituted isoxazole derivative and a specific acetal compound, and further, a formula (A Or a cyclic compound represented by the formula (B), specifically, compounds 1 to 72 described in Chemical formulas 8 to 12 of the same publication. JP 2001
The general formulas (H), (G), and
The compound represented by (P), specifically, [Chemical Formula 3] of the publication.
To [Chemical Formula 9] and [Chemical Formula 11] to [Chemical Formula 53]. A plurality of these contrast adjusting agents may be used in combination.

The contrast enhancer particularly preferably used in the present invention is represented by the general formulas (H-1), (H-2), (H-3) and (H-4) described in JP-A-2001-27790. ,
Hydrazine derivatives represented by (H-5) and (H-1-1) (specifically, compounds H-1-1 to H- described in the publication).
1-28, Compounds H-2-1 to H-2-9, Compound H-
3-1 to H-3-12, Compounds H-4-1 to H-4-2
1, compounds H-5-1 to H-5-5), JP-A-2001-
The substituted alkene derivative represented by the general formula (1) described in Japanese Patent No. 125224 (specifically, [Chemical Formula 1
0] to [Chemical 55]).

The contrast enhancer of the present invention is water or a suitable organic solvent such as alcohols (methanol, ethanol,
Propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide,
It can be used by dissolving in dimethyl sulfoxide, methyl cellosolve and the like. Also, by well-known emulsification and dispersion method, it is dissolved using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone. However, an emulsified dispersion can be mechanically prepared and used. Alternatively, by a method known as a solid dispersion method, the powder of the contrast-increasing agent may be dispersed in a suitable solvent such as water by a ball mill, a colloid mill, or ultrasonic waves before use.

The contrast increasing agent of the present invention may be added to any layer on the image forming layer side of the support, but it is preferably added to the image forming layer or a layer adjacent thereto. The addition amount is the grain size of the silver halide grains, the halogen composition,
The optimum amount varies depending on the degree of chemical sensitization and the type of inhibitor,
Although not uniform, a range of about 10 ^-6 to ¹ mol, particularly 10 ^-5 to 10 ^-1 mol per mol of silver is preferable.

The photothermographic material of the present invention is disclosed in JP-A-2000-122220 for the purpose of increasing sensitivity and preventing fog.
The compound represented by the general formula 1 (antifoggant) described in Japanese Patent Publication (KOKAI) may be contained. Specifically, [Chemical formula 3] of the same publication
[Chemical formula 12] can be mentioned.

As the compound used as the antifoggant of the present invention, a commercially available compound can be used,
Also, for example, Chem. Pharm. Bulletin, 31 (8), 2632 (1983),
J. Chem. Soc., Section B Physical Organic Chemistr
y, Part1.pp.145-148 (1971), J. Amer. Chem. Soc. 7
7, 1909 (1955), Org. Prep. Proced. Int. 28 (5), 609 (1
996), Chem. Ber. 44, 1236 (1911), J. Amer. Chem. S
oc. 60, 2502 (1938), Bull.Soc.Khim.Fr. 25 (3) 173 (19
01), Chem. Abstr. 9861 (1960), DE 297018, Justus Li
It can also be synthesized according to the method described in ebigsAnn. Chem. 300 299 (1898) and the like.

The amount of the compound used as the antifoggant of the present invention is not particularly limited, but is 10 ^-4 mo.
1 to 1 mol / Agmol is preferable, and particularly 10 ⁻³ mo
1 to 0.3 mol / Agmol is preferable.

The compound used as the antifoggant of the present invention may be added in either the light-sensitive layer or the non-light-sensitive layer, preferably the light-sensitive layer. As a typical embodiment,
A photothermographic material having at least one photosensitive layer on a support and a layer adjacent thereto, the photosensitive layer containing a photosensitive silver halide, an organic silver salt and a binder, and further used as the antifoggant. At least one of the compounds
Seed-containing mode, photosensitive layer containing photosensitive silver halide, organic silver salt and binder, and adjacent layer containing at least one compound used as the antifoggant, photosensitive layer being photosensitive A mode containing silver halide and a binder, further containing at least one compound used as an antifoggant and containing an organic silver salt in an adjacent layer, and a photosensitive silver halide and a binder in a photosensitive layer. In this embodiment, the adjacent layer contains an organic silver salt and further contains at least one compound used as the antifoggant. The aspect of the present invention is preferable.

The compound used as the antifoggant of the present invention is preferably added after being dissolved in an organic solvent.

The photosensitive silver halide used in the photothermographic material of the present invention can be prepared by any method known in the photographic art, such as a single jet method or a double jet method, for example, an ammonia method emulsion, a neutral method, It can be prepared by any method such as an acidic method. It can thus be pre-prepared and then mixed with the other components of the invention and incorporated into the composition used according to the invention. In this case, in order to sufficiently bring the photosensitive silver halide into contact with the organic silver salt, for example, as a protective polymer when preparing the photosensitive silver halide, US Pat. Nos. 3,706,564 and 3 , 70
6,565, 3,713,833, 3,748,143, British Patent 1,
Means using a polymer other than gelatin such as polyvinyl acetals described in the specification of No. 362,970,
Means for enzymatically degrading gelatin in light sensitive silver halide emulsions as described in British Patent 1,354,186 or as described in U.S. Pat. No. 4,076,539. In addition, by preparing the photosensitive silver halide grains in the presence of a surfactant, various means such as a means for omitting the use of the protective polymer can be applied.

The silver halide functions as an optical sensor, and preferably has a small grain size in order to suppress white turbidity after image formation and to obtain a good image quality. The average particle size is 0.1 μm or less, preferably 0.1 μm.
01 to 0.1 μm, particularly 0.02 to 0.08 μm is preferable. 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, in the case of non-normal crystals, for example, in the case of spherical, rod-shaped or tabular grains, it means the diameter when considering a sphere equivalent to the volume of silver halide grains. The silver halide is preferably monodisperse. The term “monodispersion” as used herein means that the degree of dispersion calculated by the following formula is 40% or less. It is more preferably 30% or less, and particularly preferably 0.1% to 25%. Dispersion (%) = (standard deviation of particle size) / (average value of particle size)
× 100

In the present invention, it is more preferable that the silver halide grains have an average grain size of 0.1 μm or less and that they are monodisperse grains. By controlling the grain size within this range, the graininess of the image is also improved.

The shape of silver halide is not particularly limited, and it may be cubic or octahedral so-called normal crystal or non-normal crystal spherical, rod-shaped, tabular, or other grains. The silver halide composition is also not particularly limited and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide.

The amount of silver halide is 50% or less, preferably 25%, based on the total amount of silver halide and the above-mentioned organic silver salt.
% To 0.1%, more preferably 15% to 0.1%.

The light-sensitive silver halide used in the photothermographic material of the present invention is also a halide in the preparation of organic silver salts as described in British Patent 1,447,454. By causing a halogen component such as ions to coexist with an organic silver salt-forming component and injecting silver ions into the component, the organic silver salt can be produced almost at the same time.

As still another method, a solution or dispersion of an organic silver salt prepared in advance or a sheet material containing the organic silver salt is allowed to act with a silver halide forming component to expose a part of the organic silver salt to light. It can also be converted into a polar silver halide. The silver halide thus formed is in effective contact with the organic silver salt and exhibits a preferable effect. The silver halide-forming component is a compound capable of reacting with an organic silver salt to produce a photosensitive silver halide. What kind of compound corresponds to this compound and is effective is determined by the following simple test. I can do things. That is, the organic silver salt and the compound to be tested are mixed and, if necessary, heated and then examined by X-ray diffractometry for the presence of a peculiar peak to silver halide.
Examples of silver halide-forming components that have been confirmed to be effective by such tests include inorganic halides, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. Are U.S. Pat. Nos. 4,009,039, 3,457,075 and 4,003,749.
Japanese Patent No. 1,498,956 and Japanese Patent Laid-Open Nos. 53-27027 and 53-25420.
It is described in detail in the official gazette.

These silver halide-forming components are used stoichiometrically in small amounts with respect to the organic silver salt. Usually, the range is 0.001 mol to 0.7 per 1 mol of the organic silver salt.
mol, preferably 0.03 mol to 0.5 mol. Two or more kinds of silver halide-forming components may be used in combination within the above range. Although various conditions such as reaction temperature, reaction time and reaction pressure in the step of converting a part of the organic silver salt into silver halide using the above-described silver halide forming component can be appropriately set according to the purpose of preparation. , The reaction temperature is usually 20 ℃
~ 70 ° C, the reaction time is 0.1 seconds to 72 hours,
The reaction pressure is preferably set to atmospheric pressure. This reaction is also preferably carried out in the presence of the polymer used as the binder described below. In this case, the amount of the polymer used is 0.01 to 100 parts by mass, preferably 0.1 to 10 parts by mass per 1 part by mass of the organic silver salt.

The photosensitive silver halide prepared by the above-mentioned various methods includes, for example, sulfur-containing compounds, gold compounds,
Platinum compound, palladium compound, silver compound, tin compound,
Chemical sensitization can be performed with a chromium compound or a combination thereof. The method and procedure of this chemical sensitization are described in, for example, U.S. Pat. Bulletin,
No. 51-81124. Further, when a part of the organic silver salt is converted into a photosensitive silver halide by the silver halide forming component, US Pat. No. 3,980,482 is used.
As described in the specification, a low molecular weight amide compound may be coexistent in order to achieve the sensitization.

In addition, these photosensitive silver halides are added to groups 6 to 11 of the Periodic Table of the Elements in order to adjust illuminance and gradation.
Group metals such as Rh, Ru, Re, Ir, O
An ion such as s or Fe, or a complex or complex ion thereof can be contained. Particularly, it is preferable to add it as a complex ion, and for example, an Ir complex ion such as [IrCl ₆ ] ^{2 −} may be added due to poor illumination.

As the method of chemically sensitizing the photosensitive silver halide grains in the present invention, it is preferable that they are chemically sensitized with chalcogen, as is well known in the art. That is, a sulfur sensitization method, a selenium sensitization method, a tellurium sensitization method, a noble metal sensitization method such as a gold compound, platinum, palladium, or an iridium compound, or a reduction sensitization method can be used.

The photothermographic material is preferably chemically sensitized with a chalcogen compound. Japanese Patent Laid-Open No. 9-29737
No. 0 and JP-A No. 11-65020 disclose chemical sensitization with chalcogen compounds and gold compounds. However, the effect is high sensitivity and high Dmax, and there is no description about the running stability and the stability of% variation, and the relevance to the problems and effects of the present invention is not recognized. In the present invention, it is preferable that the silver halide grains are chemically sensitized with a chalcogen compound before being mixed with the organic silver salt.

As the sulfur sensitizer which can be used in the present invention, various sulfur compounds such as thiosulfates, thioureas, thiazoles and rhodnins are used in addition to the sulfur compounds contained in gelatin. You can Specific examples are US Pat. Nos. 1,574,944 and 2,2.
78,947, 2,410,689, 2,728,668, 3,50.
Nos. 1,313 and 3,656,955.

As the selenium sensitizer that can be used in the present invention, the selenium compounds disclosed in conventionally known patents can be used. That is, it is usually used by adding an unstable selenium compound and / or a non-unstable selenium compound and stirring the emulsion at a high temperature, preferably 40 ° C. or higher for a certain time. Unstable selenium compounds are disclosed in JP-B-41-15748 and JP-B-43-13.
489, JP-A-4-25832, JP-A-4
It is preferable to use the compounds described in JP-A-109240. Specific examples of the unstable selenium sensitizer include isoselenocyanates (for example, aliphatic isoselenocyanates such as allyl isoselenocyanate), selenoureas, selenoketones, selenamides, selenocarboxylic acids (for example, 2 -Selenopcopionic acid, 2-selenium butyric acid), selenoesters, diacyl selenides (for example, bis (3-chloro-2,6-dimethoxybenzoyl) selenide), selenophosphates, phosphine selenides, colloidal metal selenium, etc. Can be mentioned.

The non-labile selenium compound used in the present invention is disclosed in JP-B-46-4553 and JP-B-52-
The compounds described in JP-B 34492 and JP-B-52-34491 are used. Examples of non-labile selenium compounds include selenious acid, potassium selenocyanide,
Examples thereof include selenazoles, quaternary salts of selenazoles, diaryl selenides, diaryl diselenides, dialkyl selenides, dialkyl diselenides, 2-selenazolidinediones, 2-selenooxazolidinethiones and derivatives thereof.

Examples of tellurium sensitizers used in the present invention include those disclosed in JP-A-4-204640 and 4-2.
No. 71341, No. 4-333043, No. 5-
No. 303157, No. 6-027573, No. 6
No. 175258, No. 6-180478, No. 6-208186, No. 6-208184,
6-317867, 7-092599, 7-098483, 7-104415, 7-140579, and journals.
Of Chemical Society Chemical Communication (J.Chem.Soc.Chem.Commun.) 635 (198)
0), S. S.Patai, The Chemistry
The Organic Selenium and Tellurium Compounds (The Chemistryof Organic Seleniu
m Telluriumcompounds), Vol. 1 (1986),
Vol. 2 (1987) and the like can be used.

In the present invention, chemical sensitization by at least one of selenium sensitization and tellurium sensitization is preferable. Tellurium sensitization is particularly preferable. Further, in the present invention, sulfur sensitization, selenium sensitization and tellurium sensitization may be used alone or in any combination. Combinations are preferred.

The amount of the chalcogen sensitizer used in the present invention is not particularly limited as long as the effects of the present invention are exhibited, but 1 × 10 ^-8 to 1 × 1 per mol of silver halide.
0 ^-1 mol is preferable, and more preferably 1 x 10 ^-7 to 1
× 10 ^-2 mol is preferable.

The transparent support used in the present invention is a plastic film (for example, polyethylene terephthalate (PET), polycarbonate, polyimide, nylon, cellulose triacetate, polyethylene naphthalate) in order to prevent deformation of the image after development processing. preferable. The thickness of the support is preferably 90 to 200 μm, more preferably 100 to 175 μm. Also, the support is preferably heat-treated. The heat treatment of the support means that after the support is formed into a film and before the image-forming layer is coated, the temperature is 30 ° C. or higher, preferably 35 ° C. or higher, higher than the glass transition point of the support. It is more preferable to heat at a temperature higher than 40 ° C.
However, the effect of the present invention cannot be obtained by heating at a temperature exceeding the melting point of the support.

The support film-forming method and the subbing method of the present invention can be carried out by known methods, but preferably, paragraph [0030] of JP-A-9-50094.
~ The method described in [0070] is used.

The light-sensitive material of the present invention preferably has an image forming layer on one side of the support, and the Vickers hardness of the uppermost layer on the image forming layer side is 40 to 150.

The Vickers hardness referred to in the present invention is JIS Z.
2251 has a hardness that can be measured according to the micro hardness test method. Specifically, using an indenter having a regular square pyramid of diamond with a diagonal angle of 136 degrees, the load F (kgf) when a dent is formed on the test surface is the average of the diagonal lengths of the dents d (m
It is the quotient divided by the surface area obtained from m) and is calculated by the following formula. Vickers hardness (Hv) = 1.8544F / d ²

The measuring model is JIS B 7734.
Must be compatible with (micro hardness tester). For example, it is preferable to use MHA-400 (manufactured by NEC Corporation) in an environment of 23 ° C. and 50% relative humidity.
A scanning electron microscope (S
The hardness is obtained when the indenter is pushed to a thickness of 50% of the thickness from the outermost surface observed by EM).

To set the Vickers hardness within the above range,
Examples thereof include a method using a hydrophobic binder described below, a method of adjusting with a matting agent, and a method of adding a solid filler to the uppermost layer.

As the hydrophobic binder, polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester and polymer latex are particularly preferably used.

The photothermographic material of the present invention has at least one image forming 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-image forming layer on the image forming layer. In order to control the amount or wavelength distribution of light passing through the image forming layer, a filter dye layer may be formed on the same side as the image forming layer and / or an antihalation dye layer, a so-called backing layer may be formed on the opposite side, The image forming layer may contain a dye or a pigment. The dye used may be any compound as long as it has the desired absorption in the desired wavelength range. For example, JP-A-59-648.
1, JP-A-59-182436, US Pat. Nos. 4,271,263, 4,594,312, European Patent Publication 533,008, and European Patent Publication 652,473. JP-A-2-216140, JP-A-4-348339 and JP-A-7-191432.
The compounds described in JP-A Nos. 7-301890 and 7-301890 are preferably used.

In the present invention, particularly preferably used dyes are compounds represented by the general formulas (1a), (2), (3), (1b) and (1c) described in JP-A No. 2001-5135. Specifically, [Chemical formula 86] to [Chemical formula 8] of the publication.
9] can be mentioned.

The non-image forming layer provided on the image forming layer preferably contains a matting agent, and may further contain a polysiloxane compound, a sliding agent such as wax or liquid paraffin. The image forming layer may be a plurality of layers, or the image forming layer may be a high sensitivity layer / low sensitivity layer or a low sensitivity layer / high sensitivity layer for adjusting gradation.

The heat-developable light-sensitive material of the present invention forms a photographic image by heat-development treatment, and contains at least a reducible silver source (organic silver salt), a photosensitive silver halide, a developer (reducing agent), Further, it is preferable that the photothermographic material contains a toning agent for suppressing the color tone of silver, if necessary, usually in a state of being dispersed in an (organic) binder matrix. The photothermographic material of the present invention is stable at room temperature, but is developed by being heated to a high temperature (for example, 80 to 140 ° C.) after exposure. When heated, silver is produced through a redox reaction between an organic silver salt (which functions as an oxidizing agent) and a reducing agent. This redox reaction is promoted by the catalytic action of the latent image generated on the silver halide upon exposure. The silver produced by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas and forms an image. This reaction process proceeds without supplying a treatment liquid such as water from the outside.

The photothermographic material of the present invention contains a reducing agent. Examples of suitable reducing agents are described in US Pat. No. 3,770,4
No. 48, No. 3,773,512, No. 3,
593,863 and RD 17029 and 2
9963, and includes the following.

Aminohydroxycycloalkenone compounds (eg 2-hydroxypiperidino-2-cyclohexenone); amino reductones esters (eg piperidinohexose reductone monoacetate) as precursors of reducing agents An N-hydroxyurea derivative (for example, Np-methylphenyl-N-hydroxyurea); an aldehyde or ketone hydrazone (for example, anthracene aldehyde phenylhydrazone);
Phosphoramidophenols; Phosphoramidoanilines; Polyhydroxybenzenes (eg, hydroquinone, tert-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); Sulfhydroxamic acids (eg, Benzenesulfhydroxamic acid); sulfonamide anilines (for example, 4- (N-methanesulfonamide) aniline); 2-tetrazolylthiohydroquinones (for example, 2-methyl-5- (1-phenyl-5-tetrazolylthio) ) Hydroquinone); tetrahydroquinoxalines (eg, 1,2,3,4-tetrahydroquinoxaline); amidoximes; azines (eg, combination of aliphatic carboxylic acid aryl hydrazides and ascorbic acid); poly Combination of droxybenzene and hydroxylamine, reductone and / or hydrazine; Hydroxanoic acids; Combination of azines and sulfonamidephenols; α-Cyanophenylacetic acid derivative; Combination of bis-β-naphthol and 1,3-dihydroxybenzene derivative 5-pyrazolones; sulfonamide phenol reducing agent; 2-phenylindane-
1,3-dione and the like; chroman; 1,4-dihydropyridines (for example, 2,6-dimethoxy-3,5-dicarboethoxy-1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy- 3-tert-
Butyl-5-methylphenyl) methane, bis (6-hydroxy-m-tri) mesitol,
2,2-bis (4-hydroxy-3-methylphenyl)
Propane, 4,5-ethylidene-bis (2-tert-
Butyl-6-methyl) phenol), UV-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among them, particularly preferable reducing agents are hindered phenols. As the hindered phenols, Japanese Patent Application Laid-Open No. 2001-2001
Compounds represented by the general formula (A) described in JP-A-133924, specifically, [Chemical formula 65] and [Chemical formula 66] of the same document are mentioned.

The amount of the reducing agent used in the present invention is 1 m of silver.
1 × 10 ^-2 10 mol are preferred per ol, particularly preferably 1 × 10 ^-2 ~1.5mol.

In the photothermographic material of the present invention, it is desirable to use an additive (hereinafter, referred to as a tone adjusting agent) called a tone adjusting agent, a tone adjusting agent or an activator toner together with the above-mentioned respective components. The toning agent has a function of participating in the redox reaction between the organic silver salt and the reducing agent to make the resulting silver image a dark color, especially black. Examples of suitable toning agents used in the present invention are disclosed in RD17029 and include the following.

Imides (eg, phthalimide); Cyclic imides, pyrazolin-5-ones, and quinazolinones (eg, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2). , 4-thiazolidinedione); naphthalimides (eg, N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, hexamine trifluoroacetate of cobalt), mercaptans (eg, 3-mercapto-1,2,4). -Triazole); N
-(Aminomethyl) aryldicarboximides (eg N- (dimethylaminomethyl) phthalimide);
Blocked pyrazoles, isothiuronium (is
thiouronium) derivative and certain photobleaching agents in combination (eg N, N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole),
1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate), and 2- (tribromomethylsulfonyl) benzothiazole); merocyanine dyes (eg 3-ethyl-5-
((3-Ethyl-2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-
Thio-2,4-oxazolidinedione); phthalazinone, phthalazinone derivatives or metal salts of these derivatives (for example, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3-dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); Phthalazine + phthalic acid combination; phthalazine (including adduct of phthalazine) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivative and its anhydride (eg, phthalic acid, 4 -Methylphthalic acid, 4
-Nitrophthalic acid and tetrachlorophthalic anhydride)
A combination with at least one compound selected from: quinazolinediones, benzoxazine, orthoxazine derivatives; benzoxazine-2,4-diones (for example, 1,3-benzoxazine-2,4-dione); pyrimidine And asymmetric-triazines (eg 2,4-dihydroxypyrimidine), and tetraazapentalene derivatives (eg 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6)
a-tetraazapentalene). Among these, phthalazone or phthalazine is preferable as a toning agent.

The photothermographic material of the present invention includes, for example, JP-A-63-159841, JP-A-60-140335, JP-A-63-231437 and JP-A-63-2596.
No. 51, No. 63-304242, No. 63-1
5245, U.S. Pat. Nos. 4,639,414, 4,740,455 and 4,741,9.
No. 66, No. 4,751,175, No. 4,
The sensitizing dyes described in 835,096 can be used. Useful sensitizing dyes used in the present invention are, for example, R
D17643 IV-A (Dec. 1978, p.23),
Item 1831X of the same item (p.437, August 1978)
It is described in the literature described or cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, JP-A-9-34078, JP-A-9-54409,
The compounds described in JP-A-9-80679 are preferably used.

A particularly preferable sensitizing dye is represented by the general formula [1] described in JP-A No. 2001-100360.
To [4], specifically, [Chemical formula 5] to [Chemical formula 16] of the same publication.

The above infrared sensitizing dyes or spectral sensitizing dyes are described, for example, by F.M.Harmer, The Chemistry.
Volume 18 of The Heterocylic Compounds, The Cyanine
Dyesand Related Compounds (A.Weissberger ed.Inter
Published by science, New York 1964), Japanese Patent Laid-Open No. 3-1
No. 38638, No. 10-73900, No. 9-510022, U.S. Pat. No. 2,734,90.
It can be easily synthesized by the method described in No. 0 and British Patent No. 774,779. Specifically, the manufacturing method is described in JP 2000-95958 A and the like.

In the present invention, the photosensitive dye may be used alone.
Good, but use two or more types of photosensitive dyes in combination
You can also When the photosensitive dye of the present invention is used alone,
When combined with, the total photothermographic material is 1 m²
5 × 10 each^-7~ 1.5 × 10^-6mol is preferred
And more preferably 8 × 10^-7~ 1.4 × 10 ^-6
It is contained at a ratio of mol.

Since the photosensitivity is particularly high when supersensitized, the printout silver after development tends to be large and is particularly effective in the present invention when the deactivating agent is not deactivated. Further, when infrared sensitized, the infrared sensitizing dye has a redox potential capable of reducing silver halide and some organic silver salts. In the presence of a reducing agent capable of reducing the organic silver salt of, the fog silver is likely to form silver clusters. The generated silver clusters also act as catalyst nuclei to induce fog, which reduces the storage stability when stored in the dark, and increases the printout silver when placed in the light after development. Such phenomenon occurs. Further, since the infrared light-sensitive material has sensitivity up to a heat radiation region outside the visible light range, it is effective for increasing printout silver due to heat radiation even in a dark place. In particular, the effect is great in the case of infrared spectrally sensitized photothermographic materials in which the sensitivity is increased by a supersensitizer.

These sensitizing dyes may be used alone or in combination, and the combination of sensitizing dyes is often used particularly for the purpose of supersensitization. Along with the sensitizing dye, a dye having no spectral sensitizing effect itself or a substance that does not substantially absorb visible light and exhibits supersensitization may be included in the emulsion. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are described in RD17643 (issued in December 1978) No. 2
Page 3, 1V, J, or Japanese Examined Patent Publication No. 9-25500, Japanese Examined Patent Publication No. 43-4933, and Japanese Patent Laid-Open No. 59-190.
32, 59-192242, JP-A-5-
It is described in Japanese Patent No. 3414332.

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

An antifoggant may be contained in the photothermographic material of the invention. Mercury compounds known as effective antifoggants, for example, in US Pat. No. 3,589,903, are environmentally unfavorable. Therefore, non-mercury antifoggants have been studied for a long time. Non-mercury antifoggants include, for example, US Pat. No. 4,546,
Antifoggants such as those disclosed in Nos. 075 and 4,452,885 and JP-A-59-57234 are preferred.

In the present invention, an oxidizing agent which reduces fog after development can be used. As such an oxidizing agent, for example, JP-A-50-119624, JP-A-50-120328 and JP-A-51-21333 are preferable.
No. 2, gazette 54-58022, gazette 56-705.
43, 56-99335, 59-90.
No. 842, No. 61-129642, No. 62-
129845, JP-A-6-208191,
No. 7-5621, No. 7-2781, No. 8-
15809, US Pat. Nos. 5,340,712, 5,369,000 and 5,464.
No. 737, No. 3,874,946, No. 4,756,999, No. 5,340,712, European Patent No. 605,981A1 and No. 62.
2,666A1 publication, 631,176A1 publication,
The compounds described in JP-B No. 54-165, JP-A No. 7-2781, US Pat. Nos. 4,180,665 and 4,442,202 can be used.

In the present invention, the oxidizing agent is 10 mg / m ²
~ 3 g / m ² It is preferable to contain, 50 mg / m ² ~
1 g / m ² is more preferable.

In the present invention, the oxidizing agent may be added by any method such as a solution, powder or solid fine particle dispersion, and it is particularly preferable that solid fine particles are dispersed in the image forming layer. A dispersion aid may be used during dispersion. Also, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent, and a toning agent.

In addition to the above-mentioned oxidizing agents, suitable antifoggants are compounds such as those disclosed in US Pat. Nos. 3,874,946 and 4,756,999. , JP-A-9-288328, paragraph numbers [0030] to [0036], JP-A-9-90550, paragraph number [0062].
To [0063], US Pat. No. 5,028,523 and EP 600,
587, 631,176, 605,9
The compounds disclosed in JP-A-81 are preferably used.

Binders suitable for the photothermographic material of the present invention are transparent or translucent and generally colorless, and include natural polymers, synthetic resins, polymers and copolymers, and other film-forming media such as gelatin, gum arabic, and the like. Poly (vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid) ), Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)),
Poly (ester) s, poly (urethane) s, phenoxy resin, poly (vinylidene chloride), poly (epoxide)
, Poly (carbonate) s, poly (vinyl acetate), cellulose esters, poly (amides). It may be hydrophilic or hydrophobic, but in the present invention,
A hydrophobic transparent binder is preferably used in order to reduce fog after heat development. Preferred binders include polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester,
Examples include polycarbonate, polyacrylic acid, polyurethane and the like. Among them, polyvinyl butyral, cellulose acetate, cellulose acetate butyrate,
Polyester is particularly preferably used. More preferably, it is cellulose acetate butyrate.

Another preferred binder is the polymer latex described below. The polymer latex is preferably contained in the image forming layer. The polymer latex is preferably contained in an amount of 50% by mass or more based on the total binder. In the present invention, the “polymer latex” is a dispersion of a water-insoluble hydrophobic polymer as fine particles in a water-soluble dispersion medium. As the dispersed state, the polymer is emulsified in the dispersion medium, emulsion-polymerized, micelle-dispersed, or the polymer chain has a partially hydrophilic structure and the molecular chains themselves are molecularly dispersed. Any of these may be used.

Regarding the polymer latex in the present invention, “Synthetic resin emulsion (Taira Okuda, edited by Hiroshi Inagaki, published by Kobunshi Kogyokai (1978))”, “Application of synthetic latex (Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Edited by Keiji Kasahara, published by Kobunshi Kogyokai (1993), "" Chemistry of synthetic latex (Souichi Muroi, published by Kobunshi Kogyokai (197)
0)) ”and the like.

The average particle size of the dispersed particles is 1 to 50,000 n.
m, more preferably about 5 to 1,000 nm. The particle size distribution of the dispersed particles is not particularly limited, and it may have a wide particle size distribution or a monodisperse particle size distribution. As the polymer latex, other than a polymer latex having a normal uniform structure, a so-called core /
Shell type latex may be used. In this case, it may be preferable for the core and shell to have different glass transition temperatures. Minimum film forming temperature (MFT) of the polymer latex of the present invention
Is preferably -30 to 90 ° C, more preferably 0 to 70 ° C. A film forming auxiliary may be added to control the minimum film forming temperature. The film-forming aid 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, the above-mentioned "Chemistry of Synthetic Latex" (Souichi Muroi, published by Kobunshi Publishing Association (197
0)) ”.

Examples of the polymer used in the polymer latex include acrylic resin, vinyl acetate resin, polyester resin, polyurethane resin, rubber resin, vinyl chloride resin, vinylidene chloride resin, polyolefin resin, and copolymers thereof. . The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer obtained by polymerizing a single monomer,
It may be 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 5,000 to 1,000,000, preferably 10.0.
About 100 to 100,000 is preferable. If the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and if it is too large, the film-forming property is poor, which is not preferable.

Specific examples of the polymer latex used as the binder of the image forming layer of the photothermographic material of the present invention include methyl methacrylate / ethyl acrylate / methacrylic acid copolymer latex, methyl methacrylate / 2-ethylhexyl acrylate / styrene / acryl. Acid copolymer latex, styrene / butadiene / acrylic acid copolymer latex, styrene / butadiene / divinylbenzene / methacrylic acid copolymer latex, methylmethacrylate / vinyl chloride / acrylic acid copolymer latex, vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid Examples thereof include latex of copolymer.

Further, such polymers are commercially available, and the following polymers can be used. For example, as an example of acrylic resin, Sebian A-4635, 465
83, 4601 (all manufactured by Daicel Chemical Industries, Ltd.),
Nipol Lx811, 814, 821, 820, 8
FINETEX ES650, 611 as polyester resins such as 57 (above, manufactured by Nippon Zeon Co., Ltd.)
675, 850 (all manufactured by Dainippon Ink and Chemicals, Inc.),
As a polyurethane resin such as WD-size, WMS (above, manufactured by Eastman Chemical), HYDRAN
As rubber resin such as AP10, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.), LACSTAR is used.
7310K, 3307B, 4700H, 7132C
(Above, Dainippon Ink and Chemicals, Inc.), Nipol L
x416, 410, 438C, 2507, etc. (Nippon Zeon Co., Ltd.), etc.
51, G576 (above, manufactured by Nippon Zeon Co., Ltd.), vinylidene chloride resin as L502, L513 (above Asahi Kasei Corporation), and olefin resin as Chemipearl S120, SA100 (above Mitsui Sekiyu). Chemical Co., Ltd.) and the like. These polymers may be used alone, or may be used by blending two or more kinds as necessary.

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. When the polymer latex is used in the image forming layer, 50% by mass or more of the total binder in the image forming layer is preferably the above polymer latex, and more preferably 70% by mass or more is the above polymer latex. In that case, if necessary, hydrophilic polymers such as gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and hydroxypropyl methyl cellulose may be added to the image forming layer in an amount of 50% by mass or less of the total binder. Good. The addition amount of these hydrophilic polymers is preferably 30% by mass or less of the total binder in the image forming layer.

When a polymer latex is used for the image forming layer, the image forming layer is preferably prepared by applying an aqueous coating solution and then drying. However, the term “aqueous” as used herein means that 50% by mass or more of the solvent (dispersion medium) of the coating liquid is water, and preferably 65% by mass or more of the solvent is water. As components other than water of the coating liquid, water-miscible organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Examples of specific solvent compositions are as follows. Water / methanol = 90/10, water / methanol = 70/30, water / ethanol = 90/10, water / isopropanol = 90/10, water / dimethylformamide = 95/5, water / methanol / dimethylformamide =
80/15/5, water / methanol / dimethylformamide = 90/5/5 (however, the numbers represent mass%). The total binder amount in the image forming layer is preferably 0.2 to 30 g / m ² , more preferably 1 to 15 g / m ² .

In order to protect the surface of the photothermographic material and prevent scratches, a non-image forming layer can be provided outside the image forming layer. The binder used in these non-image forming layers may be the same kind as or different from the binder used in the image forming layers.

In the present invention, the amount of binder in the image forming layer is 0.5 to 30 g / m in order to accelerate the rate of heat development.
It is preferably ² . More preferably 1 to 15 g
/ M ² . If it is less than 0.5 g / m ² , the density of the unexposed area may increase significantly and it may not be usable.

[0106]

EXAMPLES The features of the present invention will be described more specifically with reference to the following examples. Materials shown in the following examples, amount used,
The ratio, the processing content, the processing procedure and the like can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the following specific examples.

<Example 1> 1) Preparation of an undercoated support <Preparation of polyethylene terephthalate support> One polyethylene terephthalate (hereinafter abbreviated as PET) pellet was prepared.
After drying at 30 ° C. for 4 hours, it was melted at 300 ° C., extruded from a T-die and then rapidly cooled to prepare an unstretched film. This was longitudinally stretched 3.0 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, heat setting was carried out at 240 ° C. for 20 seconds, and then relaxation was carried out in the lateral direction by 4% at the same temperature. After this, the zone at 200 ° C. was wound up at a tension of 3.5 kg / cm ^{2 and} at a speed of 20 m / min.
Heat treatment was performed for 0 minutes.

After that, the chuck part of the tenter was slittered, knurled on both ends, and wound with a force of 40N. Thus, a PET film roll having a width of 2.4 m, a length of 800 m and a thickness of 130 μm was obtained. The glass transition point was 79 ° C.

Both sides of the biaxially stretched and heat-set PET film support having a thickness of 130 μm prepared as described above were subjected to a corona discharge treatment of 8 W / m ² · min, respectively, and one surface was subjected to a corona discharge treatment. The undercoating coating solution a-1 described below is applied to a dry film thickness of 0.8 μm and dried to form an undercoating layer A-1.
Further, the following antistatic coating liquid b-1 subjected to antistatic processing was applied to the opposite surface so as to have a dry film thickness of 0.8 μm and dried to obtain an antistatic processed undercoat layer B-1.

[0110] << Subbing coating solution a-1 >>   Butyl acrylate (30% by mass), tert-butyl acryl     Rate (20% by mass), styrene (25% by mass), 2-hydr     Roxyethyl acrylate (25% by weight) copolymer latex     Kusu liquid (solid content 30%)                                                             270 g   (C-1) 0.6 g   Hexamethylene-1,6-bis (ethylene urea) 0.8 g   Polystyrene fine particles (average particle size 3 μm) 0.05 g   Colloidal silica (average particle size 90nm) 0.1g   Amount of water totaling 1000 ml

<< Undercoating Coating Liquid b-1 >> SnO ₂ / Sb (9/1 mass ratio, average particle size 0.18 μm) 200 mg / m ² amount butyl acrylate (30 mass%), styrene (20 mass%) ), Copolymer latex liquid of glycidyl acrylate (40% by mass) (solid content 30%) 270 g (C-1) 0.6 g hexamethylene-1,6-bis (ethyleneurea) 0.8 g water Total 1000 ml Amount

A corona discharge of 8 W / m ² · min was applied to the upper surface of the undercoat layer A-1 and the undercoat layer B-1 to obtain the undercoat layer A.
-1 is coated with the following undercoating upper layer coating liquid a-2 so as to have a dry film thickness of 0.1 μm to form an undercoating upper layer A-2. The undercoating upper layer B-2 having an antistatic function was obtained by applying the coating solution b-2 for the undercoating layer to a dry film thickness of 0.8 μm.

<< 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 size 3μm) 0.1g Water amount to make 1000ml

[0114] << Undercoating upper layer coating liquid b-2 >>   (C-4) 60g   Latex liquid containing (C-5) as a component (solid content 20%) 80 g   Ammonium sulfate 0.5g   (C-6) 12g   Polyethylene glycol (weight average molecular weight 600) 6g   Amount of water totaling 1000 ml

[0115]

[Chemical 1]

<< Heat Treatment of Support >> In the undercoat drying step of the above-mentioned undercoated support, the support is heated at 150 ° C.,
Then, it was gradually cooled. Winding tension is 3.6kg / c
It was carried out at m ² .

2) Preparation of emulsion and solution << Preparation of silver halide emulsion >> After dissolving 7.5 g of inert gelatin and 10 mg of potassium bromide in 900 ml of water and adjusting the temperature to 35 ° C. and pH to 3.0, Silver nitrate 74
370 ml of an aqueous solution containing g and (60/38/2) mo
1 ratio of sodium chloride, potassium bromide, potassium iodide and [Ir (NO) Cl ₅ ] salt was added to 1 × per mol of silver.
The 10 ^-6 mol and aqueous rhodium chloride salt containing 1 × 10 ^-6 mol per silver 1mol 370ml, pAg7.
While maintaining at 7, it was added by the controlled double jet method. Then 4-hydroxy-6-methyl-1,3,3
Reduction sensitization was performed by adding a, 7-tetrazaindene and adjusting pH to 8 and pAg 6.5 with NaOH to obtain an average particle size of 0.06 μm and a monodispersity of 10%. , Cubic silver iodobromide grains having a [100] plane ratio of 87% were obtained. 0.1 g of phenoxyethanol after desalting by coagulating and settling this emulsion with gelatin coagulant
Was added to adjust the pH to 5.9 and pAg to 7.5 to obtain a silver halide emulsion.

<< Preparation of Sodium Behenate Solution >> 945
32.4 g of behenic acid and 9.9 arachidic acid in ml of pure water.
g and stearic acid 5.6 g were dissolved at 90 ° C. Next, 98 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added while stirring at high speed. Next, after adding 0.93 ml of concentrated nitric acid, the mixture was cooled to 55 ° C. and stirred for 30 minutes to obtain a sodium behenate solution.

<< Preparation of Preform Emulsion of Silver Behenate and Silver Halide Emulsion >> To the above sodium behenate solution,
After the above silver halide emulsion was added and the pH was adjusted to 8.1 with sodium hydroxide solution, 147 ml of 1 mol / L silver nitrate solution was added over 7 minutes, and the mixture was stirred for 20 minutes, and water-soluble salts were removed by ultrafiltration. did. The produced silver behenate had a mean particle size of 0.8 μm and a monodispersity of 8%. After forming the flocs of the dispersion, remove the water,
After further washing with water 6 times and removal of water, it was dried.

<< Preparation of Photosensitive Emulsion >> The above preform emulsion was divided, and a solution of polyvinyl butyral (average molecular weight 3000) in methyl ethyl ketone (17% by mass) was added.
After 44 g and 107 g of toluene were gradually added and mixed, dispersion was carried out at 30 ° C. for 10 minutes at 4000 psi with a media disperser using a 0.5 mm size ZrO ₂ bead mill. After the dispersion, the organic silver particles were observed by an electron micrograph. As a result of measuring the particle size and the thickness of 300 organic silver particles, 205 were monodisperse tabular organic silver particles having an AR of 3 or more and a dispersity of 25%. The average particle size was 0.7 μm. When the organic silver particles were also observed after coating and drying, the same particles could be confirmed.

The following layers were simultaneously coated on both surfaces of the support to prepare Sample 1. Incidentally, the drying is 60 ° C,
It took 15 minutes.

3) Coating on Back Surface Side A liquid having the following composition was coated on the undercoat layer B-2 layer of the support.

<< Back Layer Coating Liquid >> Cellulose acetate butyrate (10% methyl ethyl ketone solution) 15 ml / m ² Dye-A 60 mg / m ² Matting agent (kind shown in Table 1) Bekk smoothness shown in Table 1 Addition amount C ₈ F ₁₇ (CH ₂ CH ₂ O) ₁₂ C ₈ F ₁₇ 50 mg / m ² C ₉ F ₁₉ —C ₆ H ₄ —SO ₃ Na 10 mg / m ²

4) On the undercoat layer A-2 of the image forming layer surface side coating support, a liquid having the following composition was applied so that the amount of coated silver was 1.5 g / m ² to form an image forming layer. did. << Image Forming Layer Coating Solution >> The photosensitive emulsion 240 g Sensitizing dye (0.1% methanol solution) 1.7 ml Pyridinium bromide perbromide (6% methanol solution) 3 ml Calcium bromide (0.1% methanol solution) 1 0.7 ml Oxidizing agent (10% methanol solution) 1.2 ml Antifoggant 1.0 g 2-Mercaptobenzimidazole (1% methanol solution) 11 ml Tribromomethylsulfoquinoline (5% methanol solution) 8 ml Tribromomethylsulfopyridine (5 % Methanol solution) 9 ml Hardening agent 0.4 g Hydrazine-1 0.3 g Phthalazine 0.6 g 4-Methylphthalic acid 0.25 g Tetrachlorophthalic acid 0.2 g Calcium carbonate with an average particle diameter of 3 μm 0.1 g Isocyanate compound (Desmodur N3300) ) 0.5g 1 1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane (20% methanol solution) 5.0 ml 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5 , 5-trimethylhexane (20% methanol solution) 16.0 ml

A liquid having the following composition was simultaneously coated on the image forming layer together with the image forming layer to form a surface protective layer. "Surface protective layer coating solution" Acetone 5 ml / m ² methyl ethyl ketone 21 ml / m ² Cellulose acetate butyrate 2.3 g / m ² methanol 7 ml / m ² phthalazine 250 mg / m ² Matting agent: monodisperse degree of 10% average particle size 4μm single Dispersed silica Addition amount to achieve Beck's smoothness shown in Table 1 CH ₂ = CHSO ₂ CH ₂ CONHCH ₂ CH ₂ NHCOCH ₂ SO ₂ CH = CH ₂ 35 mg / m ² Fluorine-based surfactant C ₁₂ F ₂₅ (CH ₂ CH ₂ O) ₁₀ C ₁₂ F ₂₅ 10 mg / m ² C ₈ F ₁₇ —C ₆ H ₄ —SO ₃ Na 10 mg / m ²

[0126]

[Chemical 2]

After the above-mentioned coating, the photothermographic material in roll form (Samples 1 to 1) was wound up with the image forming layer side facing outward.
4) was obtained. These samples 1 to 14 were subjected to the following exposure, heat development, and performance evaluation. 5) Exposure beam diameter (FWHM of 1/2 of beam intensity) 12.56
Using a laser plotter with a single-channel cylindrical inner surface system equipped with a semiconductor laser of μm, laser output of 50 mW, and output wavelength of 780 nm, the rotation speed of the mirror is 64000 r
Exposure was performed at pm at a main scanning speed of 633 m / sec. The overlap coefficient at this time is 0.449, and the laser energy density on the surface of the photothermographic material is 70 μJ / cm ^2.
And

6) Heat Development Processing The photothermographic material was subjected to a heat development processing on-line from the plotter through the auto carrier and using the heat developing machine shown in FIG. The roller surface material of the heat developing section was silicon rubber, and the smooth surface was Teflon nonwoven fabric, and the line speed of conveyance in the heat developing section was set to 25 mm / sec. Preheating unit 12.2 seconds (The driving system of the preheating unit and the heat developing unit are independent, and the speed difference from the heat developing unit is -0.5% to -1%.
Set to 0, the speed difference with the preheating part of the auto carrier is 0%
Setting to -1.0%, temperature setting of metal roller of each preheating section, time is 1st roller temperature 67 ° C, 2.0 seconds, 2nd roller temperature 82 ° C, 2.0 seconds, 3rd roller temperature 98
℃, 2.0 seconds, the temperature of the fourth roller 107 ℃, 2.0
Seconds, 5th roller temperature 115 ° C, 2.0 seconds, 6th roller temperature 120 ° C, 2.0 seconds), heat developing section 120 ° C
(Surface temperature of photothermographic material) 17.2 seconds, slow cooling section 13.
The heat development treatment was performed in 6 seconds. The temperature accuracy in the width direction was ± 0.5 ° C. The roller temperature is set to 5 on each side of the width of the photothermographic material (for example, 61 cm).
It was made longer by cm, and temperature was applied to that part as well, so that temperature accuracy could be obtained. Since the temperature drops sharply at both ends of each roller, the temperature of the part which is longer than the width of the photothermographic material by 5 cm is set to 1 to 3 ° C. higher than that of the central part of the photothermographic material. Care was taken so that the image density (for example, within a width of 61 cm) was uniform.

7) Evaluation << Evaluation of Transportability in Plotter / Heat Developing System >> A transport test was carried out in the system of exposure and heat development processing as described above. The transportability was evaluated by the transport failure rate when 1000 sheets were transported. At this time, the exposure was performed at a blackening rate of 80%. A conveyance failure rate of 1% or more is a practical problem, and a conveyance failure rate of less than 1% is practically acceptable.

<< Evaluation of Haze >> The haze was measured using the unexposed area of the sample which was exposed and heat-developed as described above. To measure haze, use NIPPON DENSH
OKU Corporation haze measuring device MODEL 1001D
P was used.

8) Results The evaluation results are shown in Table 1.

[0132]

[Table 1]

As is clear from Table 1, the photothermographic material of the present invention is preferable because there is no conveyance failure in the exposure / heat development system.

Example 2 In the formulation of Example 1, silver halide was chemically sensitized. The chemical sensitization is carried out by heating the silver halide emulsion to 60 ° C., thiourea dioxide,
2,3,4,5,6-pentafluorophenylphosphine selenide and chloroauric acid were added at 5 × 10 ⁻⁵ m, respectively.
ol / Agmol, 1 × 10 ⁻⁵ mol / Agmol, 8
After addition of × 10 ^-6 mol / Agmol and ripening for 50 minutes, the mixture was rapidly cooled to 35 ° C to complete the chemical sensitization to prepare a silver halide emulsion. As a result of evaluation in the same manner as in Example 1, the same result as in Example 1 was obtained, and the effect of the present invention was clear.

<Example 3> The samples used in Examples 1 and 2 were A2 size plotter FT-286 manufactured by NEC.
R, using a dry film processor FDS-6100X manufactured by FUJIFILM Corporation and a dry system auto carrier FDS-C1000, exposure and heat development processing (processing speed 25 mm / sec in the heat development section) were performed and the same evaluation was performed As a result, the same results as in Examples 1 and 2 were obtained, and the effect of the present invention was clear.

<Example 4> In Example 3, A2 size plotter FT-286R manufactured by NEC, and dry system auto carrier F manufactured by FUJIFILM Corporation.
Instead of DS-C1000, A1 / A2 size plotter FT-296R made by NEC, and dry system auto carrier FDS-C1 made by FUJIFILM Corporation
When 100 and 100 were used for exposure and heat development (processing speed of heat development part: 25 mm / sec) and the same evaluation was performed, the same results as in Examples 1 and 2 were obtained. It was clear.

<Example 5> In Examples 1 to 4, the processing speed of the heat developing section was changed from 25 mm / sec to 29 mm / sec, and the same evaluation was performed. The results were obtained, and the effect of the present invention was clear.

<Example 6> In Example 1, the main scanning speed on the surface of the photothermographic material by the plotter was 633 m /
When the same evaluation was performed by changing from seconds to 1410 m / sec, the same results as in Example 1 were obtained, and the effect of the present invention was clear.

[0139]

According to the present invention, it is possible to obtain a photothermographic material having no problem in transportability in an exposure / heat development system.

[Brief description of drawings]

FIG. 1 is a side view showing an example of the configuration of a heat developing machine used for heat developing treatment of a photothermographic material of the present invention.

[Explanation of symbols]

10 Thermal development image forming material 11 Carry-in roller pair 12 Delivery roller pair 13 roller 14 smooth surface 15 heating heater 16 Guide plate A Preheating section B heat development section C slow cooling section

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

Claims (11)

[Claims] 1. A transparent support having an image forming layer containing an organic silver salt, a photosensitive silver halide, a reducing agent, and a contrast adjusting agent, and a back layer, wherein the Beck smoothness on the back layer side is A photothermographic material, characterized in that it is from 50 seconds to 2000 seconds. 2. The photothermographic material according to claim 1, wherein the Beck smoothness on the image forming layer side of the photothermographic material is 1000 seconds or more. 3. The photothermographic material according to claim 1, wherein the Bekk smoothness on the back layer side of the photothermographic material is 130 seconds to 1000 seconds. 4. The matting agent contained on the back layer side of the photothermographic material is silica particles having a monodispersity of 3% to 30% and an average particle size of 3 μm to 15 μm. The photothermographic material according to any one of 1 to 3. 5. The photothermographic material according to claim 1, wherein the binder on the back layer side of the photothermographic material is a cellulose derivative. 6. The photothermographic material according to claim 1, wherein the binder on the back layer side of the photothermographic material is cellulose acetate butyrate. 7. The photothermographic material according to claim 1, wherein the transparent support is heat-treated. 8. The photothermographic material according to claim 1, wherein the photothermographic material is in the form of a roll wound with the image forming layer side facing outward. 9. A plotter; a thermal developing machine equipped with a preheating section, a thermal developing section, a slow cooling section, and a deodorizing device; It consists of an auto carrier, and
The processing speed of the heat developing section of the heat developing machine is 25 mm / sec to 50.
Claim 1 by an online system that is mm / sec.
9. An image forming method, which comprises exposing and developing the photothermographic material according to any one of to 8. 10. The processing speed (t ₁ ) of the auto carrier and the processing speed (t ₂ ) of the preheating section of the thermal developing machine.
10. The image forming method according to claim 9, wherein the processing speed (t ₃ ) of the heat developing section of the heat developing machine satisfies the following relationship. t ₃ > t ₂ ≧ t ₁ 11. The exposure light source of the plotter has a wavelength of 7
The image forming method according to claim 9 or 10, wherein the laser is 50 to 800 nm and the main scanning speed on the surface of the photothermographic material is 500 m / sec to 1500 m / sec.