JP2002196448A - Heat developable photosensitive material and image recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material of less fluctuation in its image density against a light and a image recording method suitable to use the material. SOLUTION: The heat developable photosensitive material is formed by applying an image forming layer containing at least one of each organic silver salt, photosensitive silver halide and a reducing agent and a protecting layer in order on a base substance. The material is specified by containing a hindered amine in at least one of these layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photothermographic material,
The present invention relates to a method for producing the photosensitive material and an image recording method.

[0002]

2. Description of the Related Art Conventionally, in the fields of medical treatment and printing plate making, waste liquid caused by wet treatment of an image forming material has been a problem in terms of workability. It is strongly desired to reduce the amount of waste liquid.

Therefore, there is a need for a technique relating to a photothermographic material for photographic technology, which enables efficient exposure with a laser imager or a laser imagesetter and can form a high-resolution and clear black image. Such photothermographic materials are described, for example, in (D. Morgan (M.
organ) and B.C. No. 3,152,904, 3,457,075 or by D. Shelly. H. Klosterboe
r) "Silver systems treated by heat (The
rally Processed Silver S
systems) "(Imaging Processes and Materials)
es and Materials) Neblette
Eighth Edition, Sturge, V.S. Walworth, A .; Shep
p), p. 279, 1989), and a photothermographic material containing an organic silver salt, photosensitive silver halide grains, and a reducing agent on a support are known. . Since this photothermographic material does not use any solution processing chemicals, it is possible to provide the user with a system that is simpler and does not damage the environment.

[0004] Such a photothermographic material is usually prepared by dispersing a reducible silver source (for example, an organic silver salt), a catalytically active amount of a photocatalyst (for example, silver halide) and a reducing agent in a resin binder matrix. When the material is subjected to a heat development treatment after exposure, silver is generated by an oxidation-reduction reaction between a reducible silver source (acting as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is accelerated by the catalytic action of the latent image generated by the exposure, and the silver generated by the reaction of the organic silver salt in the exposed area is formed as a black image according to the exposure amount.

As a technique for suppressing fogging of an image formed as described above, for example, US Pat.
No. 46, No. 4, 459, 350, No. 5, 340, 71
No. 2, 4,756,999, 5,594,143
And the disulfides disclosed in JP-B-54-35770, JP-B-61-48697, and JP-A-6-208193. Isocyanates, JP-B-54-4421261, JP-A-55-14
No. 0833, JP-A-7-209797, and the like, and thiosulfonates and derivatives thereof.
Compounds such as vinylsulfone derivatives disclosed in US Pat. No. 18,942, JP-A-6-208192 and the like have been proposed.

[0006] The above-mentioned compounds also suppress fluctuations in image density in unexposed areas or low-illuminance exposed areas after heat development due to storage conditions of the photothermographic material.

However, the fogging prevention effect of the fogging prevention technique alone may not be sufficient, in particular, there may be insufficient image density fluctuation and color tone fluctuation caused by exposure to room light or sharksten light after image formation. Development was desired.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a photothermographic material having a small image density variation with respect to light. An object of the present invention is to provide a suitable image recording method using a photothermographic material.

[0009]

The above object of the present invention has been attained by the following constitutions.

[0010] 1. In a photothermographic material in which an image forming layer and a protective layer containing at least an organic silver salt, a photosensitive silver halide and a reducing agent are laminated on a support in this order, at least one selected from the image forming layer and the protective layer A photothermographic material comprising a layer containing a hindered amine.

2. The ratio of the hindered amine contained in at least any one layer selected from the image forming layer and the protective layer to the total composition of the image forming layer and the protective layer,
2. The photothermographic material according to the above item 1, wherein the content is from 0.45 to 2.50% by mass.

3. In a photothermographic material in which an image forming layer and a protective layer containing at least an organic silver salt, a photosensitive silver halide and a reducing agent are laminated on a support in this order, at least one selected from the image forming layer and the protective layer A photothermographic material comprising a layer containing a compound having an epoxy group hydrogenated.

4. The ratio of the compound obtained by hydrogenating the epoxy group contained in at least any one layer selected from the image forming layer and the protective layer to the total composition of the image forming layer and the protective layer is 0.50 to 5.00 mass. %, The photothermographic material according to item 3,

5. 5. The photothermographic material according to any one of items 1 to 4, wherein the image forming layer contains a thiuronium compound.

6. In a photothermographic material in which an image forming layer and a protective layer containing at least an organic silver salt, a photosensitive silver halide and a reducing agent are laminated on a support in this order, at least one selected from the image forming layer and the protective layer A photothermographic material characterized in that the layer contains a compound having a sulfonic acid group and the image forming layer contains a thiuronium compound.

[7] The ratio of the compound having a sulfonic acid group contained in at least any one layer selected from the image forming layer and the protective layer to the total composition of the image forming layer and the protective layer is 0.06 to 0.4% by mass. 7. The photothermographic material according to the above item 6, wherein

8. 8. An image, wherein the photothermographic material according to any one of 1 to 7 is subjected to scanning exposure using a laser whose angle between an exposure surface and a laser beam does not become substantially perpendicular. Recording method.

9. 8. An image recording method, wherein the photothermographic material according to any one of 1 to 7 is subjected to scanning exposure using a vertical multi-laser having a non-uniform exposure wavelength.

10. 8. An image recording method, wherein the photothermographic material according to any one of the above items 1 to 7 is subjected to scanning exposure using two or more lasers.

11. The wavelength of the laser used for scanning exposure is 7
8-1.
0. The image recording method according to any one of 0.

Hereinafter, the photothermographic material of the present invention will be described. The photothermographic material of the present invention is obtained by laminating an image forming layer containing at least an organic silver salt, a photosensitive silver halide, a reducing agent, and a protective layer on a support in this order, further comprising an image forming layer and a protective layer. Wherein at least one of the layers selected from the group contains a specific compound.

Among them, there are three kinds of embodiments depending on the specific compound, and each embodiment will be described in detail below.

The first embodiment is characterized in that at least one of the image forming layer and the protective layer contains a hindered amine.

The compound is exemplified below as such a hindered amine, but in this embodiment, the structure is not limited to the following structure as long as it is a hindered amine.

[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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The hindered amine added in this embodiment is
It is not particularly limited even if it is a liquid or solid, but for the purpose of preventing diffusion in the compound layer when an undeveloped photothermographic material is stored, for preventing diffusion in the compound layer after image formation, It is preferably solid at room temperature. The hindered amine may be contained in any of the image forming layer and the protective layer. However, if there is a possibility that the compound itself may be colored, it is preferably added to the image forming layer.

By including such a hindered amine, it is possible to obtain an image which is not much affected by the storage environment of the photothermographic material before exposure, and to obtain a low density portion when exposed to light such as sharksten. Fog rise can be suppressed.

The hindered amine added to at least one of the image forming layer and the protective layer accounts for usually 0.45 to 2.50 mass% of the total composition of the image forming layer and the protective layer. %, More preferably 0.60 to 2.00% by mass.

The second embodiment is characterized in that at least one of the image forming layer and the protective layer contains a compound obtained by hydrogenating an epoxy group.

As such a compound, a compound having an epoxy group in a molecule is hydrogenated, that is, an epoxy group is opened to form an alcohol, and any compound which does not inhibit the object of the present invention can be used without any particular limitation. be able to.

Examples of such an epoxy group-containing compound before hydrogenation are described in, for example, JP-A-10-90826 and
Compounds described in 000-137307 and 2000-206641, etc., triglycidyl isocyanurate widely used in various fields, phenol novolak type epoxy resin, orthocresol novolak type epoxy resin, bisphenol A type epoxy resin, Hydrogenated bisphenol A epoxy resin, brominated bisphenol A epoxy resin, bisphenol F epoxy resin,
Bisphenol Z type epoxy resin, phenoxy resin and the like can be mentioned.

As a method for hydrogenating the aforementioned compound,
It can be performed by a conventionally known method. For example, a method of dissolving the epoxy group-containing compound in ethyl alcohol or the like and hydrogenating it with a stoichiometric amount of sodium borohydride or lithium borohydride, dissolving the epoxy group-containing compound in tetrahydrofuran or the like, and stoichiometric A method of hydrogenation with lithium aluminum hydride or the like, and a method of hydrogenation with a hydrogenation catalyst such as a nickel catalyst or a palladium catalyst, depending on the structure of the epoxy group-containing compound, can be given.

By including such a hydrogenated epoxy compound, it is possible to obtain an image which is not significantly affected by the storage environment of the photothermographic material before exposure, and to obtain an image when exposed to light such as sharksten. Of the high-concentration part can be suppressed.

The compound obtained by hydrogenating a compound having an epoxy group in the molecule, which is added to at least one of the image forming layer and the protective layer, is added to the entire composition of the image forming layer and the protective layer. The occupancy ratio is usually 0.50
5.00% by mass, and more preferably 0.80 to 4.0%.
It is preferable that the content be in the range of 50% by mass.

The third embodiment is characterized in that at least one layer selected from the image forming layer and the protective layer contains a compound having a sulfonic acid group, and the image forming layer contains a thyuronium compound.

Specific examples of the above-mentioned compound having a sulfonic acid group include 2-naphthalenesulfonic acid, 3-pyridinesulfonic acid, 5-methyl-3-pyridinesulfonic acid,
-Sulfosalicylic acid, 8-hydroxyquinoline-5-sulfonic acid, cyclohexylaminopropanesulfonic acid,
D-camphor-10-sulfonic acid, DL-camphor-10-sulfonic acid, 2- (N-morpholino) ethanesulfonic acid, 3- (N-morpholino) propanesulfonic acid, 3- (N-morpholino) -2- Hydroxypropanesulfonic acid, p-xylene-2-sulfonic acid, p-
Examples include toluenesulfonic acid, p-phenolsulfonic acid, benzenesulfonic acid, ethanesulfonic acid, altanilic acid, calmagite, cresolsulfonic acid, trifluoromethanesulfonic acid, and methanesulfonic acid.

Of the above compounds, compounds having no primary or secondary amino group in the molecule are more preferable in order to reduce discoloration of the compound itself.

Further, this embodiment is characterized in that the thiuronium compound is contained as a substance exhibiting supersensitization (hereinafter abbreviated as supersensitizer), and specific examples of the compound are shown below. The following compounds can be mentioned.

[0045]

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[0046]

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The above-described supersensitizer is preferably used in the image forming layer containing an organic silver salt and silver halide grains described below in an amount of 0.001 to 1.0 mol per mol of silver, and particularly preferably. It is preferred to be in the range of 0.01 to 0.5 mole per mole of silver.

As in the present embodiment, the photothermographic material before exposure is prepared by incorporating a compound having a sulfonic acid group in at least one of the layers selected from the image forming layer and the protective layer, and a thyuronium compound in the image forming layer. It is possible to obtain an image that is not significantly affected by the storage environment of the material, and it is possible to suppress a change in the color tone of a shakasten or the like irradiated with light.

The compound having a sulfonic acid group in at least any one layer selected from the image forming layer and the protective layer usually accounts for 0.06 to 0.3% of the total composition of the image forming layer and the protective layer. It is preferably in the range of 4% by mass, more preferably in the range of 0.09 to 0.3% by mass.

The resin for forming the support used in the first, second and third embodiments described above includes acrylic resin, polyester, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, and the like. Each resin film such as nylon, aromatic polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyimide, polyetherimide, triacetylcellulose, and the like, and furthermore, a resin film obtained by laminating two or more layers of the resin, etc. Can be.

In the image recording method described below, the support according to the present invention is preferably developed in the form of a film and then annealed from the viewpoint of dimensional stability because the latent image is formed and then developed by heat to form an image. As the above-mentioned resin, polyester, polycarbonate, polyarylate, polyetheretherketone, triacetylcellulose are preferable,
Further, among them, the polyester biaxially stretched and annealed is more preferable in terms of versatility and / or cost.

The polyester described above will be described in more detail. The polyester referred to here is a polymer compound having an ester bond in the molecular main chain, and is a polymer obtained by condensation polymerization from a diol and a dicarboxylic acid. Dicarboxylic acids are terephthalic acid, isophthalic acid, phthalic acid,
The diols are represented by naphthalenedicarboxylic acid, adipic acid, sebacic acid and the like, and the diols are represented by ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexanedimethanol and the like. In the present invention, in particular, polyethylene terephthalate (PET) or a copolymer thereof, polybutylene naphthalate (PBN) or a copolymer thereof,
Polybutylene terephthalate (PBT) or a copolymer thereof, and polyethylene naphthalate (PEN) and a copolymer thereof are preferably used. The repeating unit of these polyesters is 100 or more, especially 150
Or more, and the intrinsic viscosity is preferably 0.6 dl / g or more, more preferably 0.7 dl / g.
/ G or more. In such a case, the film-forming stability is excellent and preferable. Of course, these polyesters include known additives such as a lubricant, a stabilizer, an antioxidant, a viscosity modifier, an antistatic agent, a colorant, and a pigment. Can be arbitrarily compounded.

The thickness of the support is usually 50 to 500.
About μm, and more preferably 100 to 250 μm.

Next, an image forming layer containing essential components other than those described in the first, second and third embodiments, that is, an organic silver salt, a photosensitive silver halide and a reducing agent will be described in detail.

The photosensitive silver halide, which is an essential component in the image forming layer of the present invention, preferably has a small average particle size in order to suppress white turbidity after image formation and obtain good image quality. The size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.1 μm, and particularly preferably 0.02 μm to 0.08 μm. Here, the particle size refers to the diameter (equivalent circle diameter) of a circle having the same area as an individual particle image observed with an electron microscope. Further, the silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion determined by the following formula is 40% or less. The particle size is more preferably 30% or less, and particularly preferably 20% or less.

Monodispersity = (standard deviation of the particle size) / (average value of the particle size) × 100 The shape of the photosensitive silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane. Is preferably high, and this ratio is preferably 50% or more, more preferably 70% or more, and particularly preferably 80% or more. The ratio of the Miller index [100] plane is [11] in the adsorption of the sensitizing dye.
T] utilizing the adsorption dependency between the [1] plane and the [100] plane. T
ani, J .; Imaging Sci. , 29,165
(1985).

Another preferred form of photosensitive silver halide is tabular grains. The term "tabular grain" as used herein means a particle having a diameter calculated as a circle having the same projected area as an equivalent area, a particle diameter of r μm, and an aspect ratio = r / h of 3 or more when the vertical thickness is h μm. Among them, the aspect ratio is preferably 3 or more and 50 or less. The particle size is preferably 0.1 μm or less, and more preferably 0.1 μm or less.
It is preferably from 01 μm to 0.08 μm. These are U.S. Patent Nos. 5,264,337 and 5,314,798,
No. 5,320,958 and the like, and desired tabular grains can be easily obtained.

The photosensitive halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. Emulsions used in the present invention include P.I. Chimie e by Glafkides
t Physique Photographique
(Paul Montel, 1967);
F. Photographic Em by Duffin
ulsion Chemistry (The Foca
l Press, 1966); L. Zelik
Making and Coat by man et al
ing Photographic Emulsion
(The Focal Press, 1964) and the like.

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

These metal ions can be introduced into silver halide in the form of a metal complex or a metal complex ion. As these metal complexes or metal complex ions, six-coordinate metal complexes represented by the following general formula (1) are preferable.

In the formula (1) [ML ₆ ] ^m , M is a transition metal selected from elements of Groups 6 to 11 of the periodic table, L is a ligand, and m is 0,-, 2-, 3-. Or 4-
Represents Specific examples of the ligand represented by L include halides (fluoride, chloride, bromide and iodide), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aquo. Ligand, nitrosyl, thionitrosyl and the like, preferably aquo, nitrosyl and thionitrosyl. If an aquo ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

As M, rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os) are preferable. Specific examples of transition metal complex ions containing these are [RhCl ₆ ] ^3- ,
[RuCl ₆ ] ³⁻ , [ReCl ₆ ] ³⁻ , [RuB
r _6] ^3-, [OsCl _6] ^3-, [IrCl _6] ^4-, [Ru
(NO) Cl _5] ^2-, [RuBr ₄ (H ₂ O)] ^2-, [R
u (NO) (H ₂ O) Cl ₄ ] ^- , [RhCl ₅ (H
₂ O)] ^2-, [Re (NO) Cl _5] ^2-, [Re (NO)
(CN) ₅ ] ^2- , [Re (NO) Cl (CN) ₄ ] ^2- ,
[Rh (NO) ₂ Cl ₄ ] ^- , [Rh (NO) (H ₂ O) C
l ₄ ] ^- , [Ru (NO) (CN) ₅ ] ^2- , [Fe (C
N) _6] ^{3 -,} [Rh (NS) Cl _5] ^2-, [Os (NO)
Cl _5] ^2-, [Cr (NO) Cl _5] ^2-, [Re (NO)
Cl ₅ ] ^- , [Os (NS) Cl ₄ (TeCN)] ^2- ,
[Ru (NS) Cl ₅ ] ²⁻ , [Re (NS) Cl ₄ (Se
CN)] ^2- , [Os (NS) Cl (SCN) ₄ ] ^2- ,
[Ir (NO) Cl ₅ ] ²⁻ , [Ir (NS) Cl ₅ ] ^{2− and the} like.

The above-mentioned metal ions or metal complex ions may be used alone or in combination of two or more of the same metal and different metals. The content of these metal ions or metal complex ions is generally in the range of 1
1 × 10 ⁻⁹ to 1 × 10 ⁻² mol per mol is suitable,
Preferably it is 1 × 10 ^-8 to 1 × 10 ^-4 mol.

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

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

These metal compounds can be added by dissolving them in water or a suitable organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides). A method in which an aqueous solution of a powder or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or a silver salt solution and a halide solution are used. When they are mixed simultaneously, they are added as a third aqueous solution to prepare silver halide grains by a three-liquid simultaneous mixing method, a method in which a required amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or a method in which halogen is added. There is a method in which another silver halide grain doped with metal ions or complex ions in advance during the preparation of silver halide is added and dissolved. In particular, a method of adding an aqueous solution of a powder of a metal compound or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble halide solution.

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

In the present invention, the photosensitive silver halide grains may or may not be desalted after grain formation, but when desalting is performed, it is known in the art such as a noodle method and a flocculation method. Can be desalted by washing with water.

The silver halide grains used in the present invention are preferably chemically sensitized. Preferred chemical sensitization methods are sulfur sensitization, as is well known in the art,
Selenium sensitization and tellurium sensitization can be used. Further, a noble metal sensitization method or a reduction sensitization method of a gold compound, platinum, palladium, an iridium compound or the like can be used.

As the compounds preferably used in the above-described sulfur sensitization method, selenium sensitization method, and tellurium sensitization method, known compounds can be used, and the compounds described in JP-A-7-128768 and the like can be used. be able to. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, and P =
Compound having a Te bond, tellurocarboxylates, Te
-Organyltellurocarboxylic esters, di (poly)
Tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond, Te-containing heterocycles, tellurocarbonyl compounds,
An inorganic tellurium compound, colloidal tellurium, or the like can be used.

Compounds preferably used in the noble metal sensitization method include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, US Pat. No. 2,448,060 and British Patent 618. , 061, etc. can be preferably used.

Specific compounds used in the reduction sensitization method include, as well as ascorbic acid and thiourea dioxide,
Stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds and the like can be used. Further, reduction sensitization can be achieved by ripening the emulsion while maintaining the pH of the emulsion at 7 or more or the pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ion during grain formation.

The organic silver salt contained in the image forming layer of the present invention is a reducible silver source, and is an organic acid containing a reducible silver ion source. Examples of the organic acid used in the present invention include an aliphatic carboxylic acid, a carbocyclic carboxylic acid, a heterocyclic carboxylic acid, a heterocyclic compound and the like, and particularly a long chain (10 to 30, preferably 15 to 25 (Carbon atoms) aliphatic carboxylic acids are preferably used.

Also useful are organic silver salt complexes in which the ligand has a total stability constant for silver ions of 4.0 to 10.0.

Examples of such silver salt of organic acid include Re
search Disclosure Nos. 17029 and 29963. Among them, silver salts of fatty acids are preferably used, and silver behenate, silver arachidate and silver stearate are particularly preferably used.

The above-mentioned organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver, but a forward mixing method, a reverse mixing method, a simultaneous mixing method and the like are preferably used. Further, it is also possible to use a controlled double jet method as described in JP-A-9-127463.

In the present invention, the organic silver salt preferably has an average particle size of 1 μm or less and is monodispersed. The average particle size of the organic silver salt means that the particles of the organic silver salt are, for example, spherical,
In the case of rod-shaped or tabular grains, it refers to the diameter of a sphere equivalent to the volume of the organic silver salt grains. The average particle size is preferably 0.01 μm to 0.8 μm, particularly 0.05 μm.
m to 0.5 μm is preferred. The term “monodisperse” has the same meaning as in the case of silver halide.
0. In the present invention, the organic silver salt has an average particle size of 1 μm.
It is more preferable that the particles be monodisperse particles having a particle size of m or less. Further, the organic silver salt preferably has tabular grains having 60% or more of the total organic silver. In the present invention, the term “tabular grains” refers to a ratio of an average particle diameter to a thickness, that is, an aspect ratio (AR) represented by the following formula.
Abbreviation) means three or more.

AR = average particle size (μm) / thickness (μm) Such organic silver particles are preliminarily dispersed together with a binder, a surfactant and the like, if necessary, and then dispersed and pulverized with a media disperser or a high-pressure homogenizer. Is preferred.
For the preliminary dispersion, a general stirrer such as an anchor type or a propeller type, a high-speed rotary centrifugal radiation type stirrer (dissolver), and a high-speed rotary shear type stirrer (homomixer) can be used. Further, as the media dispersing machine, a ball mill,
Rolling mills such as planetary ball mills and vibrating ball mills, as well as bead mills, attritors, and other basket mills, which are medium agitation mills, can be used. Type, where liquids collide with each other at high speed,
Various types can be used, such as a type that passes through a fine orifice.

In the apparatus used for dispersing the organic silver particles used in the present invention, zirconia, alumina, silicon nitride, zirconia, alumina,
It is preferable to use ceramics such as boron nitride or diamond, and particularly preferable to use zirconia. When performing the above dispersion, the binder concentration,
Optimizing the predispersion method, the operating conditions of the disperser, the number of dispersions, etc., is very preferable as a method for obtaining the organic silver salt particles used in the present invention.

As the reducing agent contained in the image forming layer of the present invention, those known in the art can be used, for example, phenols, polyphenols having two or more phenol groups, naphthol , Bisnaphthols, polyhydroxybenzenes having two or more hydroxyl groups, polyhydroxynaphthalenes having two or more hydroxyl groups, ascorbic acids, 3-pyrazolidones, pyrazoline-5-ones, pyrazolines, phenylenediamine , Hydroxylamines, hydroquinone monoethers, hydroxamic acids, hydrazides, amide oximes, N-hydroxyureas, and the like.

Among the above reducing agents, when a silver aliphatic carboxylate is used as the organic silver salt, preferred reducing agents are polyphenols in which two or more phenol groups are linked by an alkylene group or sulfur, especially An alkyl group (eg, methyl group, ethyl group, propyl group, t-butyl group, cyclohexyl group, etc.) or an acyl group (eg, acetyl group, propionyl group, etc.) is located at at least one of the positions adjacent to the hydroxy substitution position of the phenol group. Polyphenols in which two or more of the substituted phenol groups are linked by an alkylene group or sulfur, for example, 1,1-bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5
5-trimethylhexane, 1,1-bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane,
1,1-bis (2-hydroxy-3-t-butyl-5-
Ethylphenyl) methane, 1,1-bis (2-hydroxy-3- (1-methylcyclohexyl) -5-methylphenyl) methane, 1,1-bis (2-hydroxy-3,
5-di-t-butylphenyl) methane, (2-hydroxy-3-t-butyl-5-methylphenyl)-(2-hydroxy-5-methylphenyl) methane, 6,6'-benzylidene-bis (2 , 4-di-t-butylphenol), 6,6'-benzylidene-bis (2-t-butyl-4-methylphenol), 6,6'-benzylidene-
Bis (2,4-dimethylphenol), 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -2-
Methylpropane, 1,1,5,5-tetrakis (2-hydroxy-3,5-dimethylphenyl) -2,4-ethylpentane, 2,2-bis (4-hydroxy-3,5-
U.S. Patent Nos. 3,589,903 and 4,021, such as dimethylphenyl) propane and 2,2-bis (4-hydroxy-3,5-di-t-butylphenyl) propane.
249 or British Patent Nos. 1,486,148 and JP-A-51-51933, 50-3611.
Nos. 0, 50-16023, 52-84727 or JP-B-51-35727; bisnaphthols described in U.S. Pat. No. 3,672,904; 2,
2'-dihydroxy-1,1'-binaphthyl, 6,6 '
-Dibromo-2,2'-dihydroxy-1,1'-binaphthyl, 6,6'-dinitro-2,2'-dihydroxy-1,1'-binaphthyl, bis (2-hydroxy-1-
Naphthyl) methane, 4,4'-dimethoxy-1,1'-
Dihydroxy-2,2'-binaphthyl and the like, and sulfonamidophenols or sulfonamidonaphthols as described in U.S. Pat. No. 3,801,321, for example, 4-benzenesulfonamidophenol, 2-benzene Sulfonamidophenol, 2,6-
Dichloro-4-benzenesulfonamidophenol, 4
-Benzenesulfonamido naphthol and the like.

The amount of the reducing agent contained in the image forming layer of the present invention varies depending on the kind of the organic silver salt and the reducing agent, and other additives.
5 to 10 mol, preferably 0.1 to 3 mol is suitable. Further, within this range, two or more of the above-mentioned reducing agents may be used in combination.

Further, in the present invention, a binder resin is used in the image forming layer in order to retain the above essential components. As such a binder resin, a resin that is not colored when a coating film is formed is preferable, for example, polyvinyl formal, polyvinyl acetoacetal, polyvinyl acetal-based resins such as polyvinyl butyral, nitrocellulose, and cellulose-based cellulose acetate butyrate. Resins, styrene resins such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-acrylic rubber copolymer, polyvinyl chloride resins such as polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polymethyl methacrylate. Acrylic resin, polyester, polyurethane, polycarbonate, polyarylate, epoxy resin, phenoxy resin and the like can be mentioned.

Since it is necessary to disperse and hold the above-mentioned organic silver salt compound with a binder resin, a resin having a hydroxyl group, a carboxyl group or a salt thereof, or a sulfonic acid or a salt thereof in a molecule is preferable, and a polyvinyl acetal-based resin is preferable. Resins, cellulosic resins, phenoxy resins, and further, modified vinyl chloride resins, modified polyesters, modified polyurethanes, modified epoxy resins, modified acrylic resins, etc., into which the above-described functional groups have been introduced, and these may be used alone. Or two or more resins may be used in combination.

Further, in addition to the above-mentioned essential components and the binder resin, the image forming layer of the present invention may contain, if necessary, an antifoggant, a toning agent, a sensitizing dye, and a substance exhibiting supersensitization (hereinafter referred to as supercolor sensitization). Various additives such as a sensitizer may be added.

Examples of such antifoggants include JP-B-54-44212 and JP-B-51-9694, and JP-A-5-9694.
No. 5-140833, compounds as disclosed in U.S. Patent No. 3,874,946 and ibid. No. _{4,756,999, -C (X 1) (} X 2) (X 3) ( wherein X ₁ and X
₂ represents a halogen atom, and X ₃ represents a hydrogen atom or a halogen atom.) Heterocyclic compounds having at least one substituent represented by the following formulas: JP-A-9-288328 and JP-A-9-90550
No. 5,028,523 and European Patent No. 6
Nos. 00,587, 605,981 and 631,
The compounds disclosed in No. 176 and the like and the compounds exemplified below may be used alone or in combination of two or more.

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Examples of toning agents added for the purpose of improving the silver tone after development include imides (for example, 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);
The blocked pyrazoles, isothiuronium (is
othiuronium) derivatives and certain photobleaches (e.g., N, N'-hexamethylene (1
-Carbamoyl-3,5-dimethylpyrazole), 1,
A combination of 8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole);
Merocyanine dyes (for example, 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, 3-dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (eg, 6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); phthalazine + A combination of phthalic acid; phthalazine (including an 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) Acid, 4-nitrophthalic acid and tetrachloro Combination of at least one compound selected from phthalic anhydride); quinazolinediones such, benzoxazine, Narutokisajin derivatives; benzoxazine-2,4-diones (e.g.,
1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric triazines (eg, 2,4-dihydroxypyrimidine), and tetraazapentalene derivatives (eg, 3,6-dimercapto-1, 4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene). Preferred toning agents include phthalazone and phthalazine.

The color tone agent may be added to a protective layer described later as long as the object of the present invention is not hindered.

Further, as a sensitizing dye, for example, for an argon ion laser light source, JP-A-60-16224
7, U.S. Pat. No. 2,486,635, U.S. Pat.
No. 1,331, West German Patent No. 936,071, Japanese Unexamined Patent Publication No.
Japanese Patent Application Laid-Open No. Sho 50-62 discloses a simple merocyanine and a helium neon laser light source described in
No. 425, No. 54-18726, No. 59-10222
Trinuclear cyanine dyes disclosed in JP-A-9-287
JP-B-48-4217 discloses merocyanines, LED light sources and infrared semiconductor laser light sources described in US Pat.
No. 2, No. 51-9609, No. 55-39818, JP-A Nos. 62-284343 and 2-105135, and JP-A No. 2-105135 discloses a thiacarbocyanine and infrared semiconductor laser light source. 59-191032, JP-A-Showa 6
0-80841 tricarbocyanines;
Dicarbocyanines containing a 4-quinoline nucleus described in general formulas (IIIa) and (IIIb) of JP-A-59-192242 and JP-A-3-67242 are advantageously selected. Further, when the wavelength of the infrared laser light source is 750 nm or more, more preferably 800 nm or more.
5-341432, Tokuhei 6-52387, 3
Sensitizing dyes described in US Pat. No. 5,109,931, U.S. Pat. No. 5,441,866 and JP-A-7-13295 are preferably used.

RD 1764 is a supersensitizer.
3, the compounds described in JP-B-9-25500, JP-B-43-4933, JP-A-59-19032, JP-A-59-192242, JP-A-5-341432 and the like can be appropriately selected and used. In the present invention, a heteroaromatic mercapto compound represented by the following general formula (2) and a disulfide compound represented by the general formula (3) that substantially produces the above-mentioned mercapto compound can be used.

General formula (2) Ar-SM General formula (3) Ar-SS-Ar In general formula (2), M represents a hydrogen atom or an alkali metal atom, and Ar represents one or more nitrogen and sulfur. , A heteroaromatic ring having a selenium or tellurium atom or a condensed heteroaromatic ring. The heteroaromatic ring is preferably benzimidazole, naphthimidazole, benzothiazole,
Naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, triazine, pyrimidine, pyridazine, pyrazine,
Pyridine, purine, quinoline or quinazoline. Ar in the general formula (3) has the same meaning as in the case of the general formula (2).

The above-mentioned heteroaromatic ring includes, for example, a halogen atom (for example, Cl, Br, I), a hydroxy group, an amino group, a carboxyl group, and an alkyl group (for example, one or more carbon atoms; Those having 4 carbon atoms) and alkoxy groups (eg one or more carbon atoms,
Preferably, it has a substituent selected from the group consisting of those having 1 to 4 carbon atoms.

Further, in the first and second embodiments of the present invention, it is more preferable to use the thiuronium compound used in the third embodiment as a supersensitizer, since a high-sensitivity image can be obtained.

The photosensitive layer of the present invention may contain a macrocyclic compound containing a hetero atom. A 9-membered or more macrocyclic compound containing at least one of a nitrogen atom, an oxygen atom, a sulfur atom and a selenium atom as a hetero atom is preferable,
A 12- to 24-membered ring is more preferred, and even more preferred is a 15-membered ring.
It is a 21-membered ring.

Representative compounds include the following compounds, which are synthesized from crown ethers by Pederson in 1967 and have been synthesized in a large number since their unique reports.
These compounds are C.I. J. Pederson, Jou
rnal of American chemical
society vol, 86 (2495), 701
7-7036 (1967); W. Gokel, S.M.
H. Korzeniowski, “Macrocycll.
ic polyether synthesis ", Sp
Ringer-Vergal, (1982) and the like.

In the image forming layer of the present invention, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid and the like may be used in addition to the additives described above. These additives and Research Disclosure
Item 17029 (p. 9-15, June 1978)
Can be appropriately selected and used within a range that does not inhibit the object of the present invention.

When active hydrogen is contained in the binder resin of the image forming layer, a plurality of metal alkoxide portions such as conventionally known polyfunctional isocyanate compounds, polyfunctional carbodiimide compounds, alkoxysilane compounds and alkoxytitanium compounds may be used. The film strength may be improved by adding a cross-linking agent such as a metal alkoxide contained in each molecule.

In the present invention, the image forming layer may be a single layer or a plurality of layers having the same or different compositions. The thickness of the image forming layer is usually 10 to 30 μm.
It is.

The protective layer used in the photothermographic materials of the first, second and third embodiments is composed of the binder resin described in the above-mentioned image forming layer and additives optionally added, As the binder resin for the protective layer, the binder resin described for the image forming layer can be appropriately selected and used.

As an additive to be added to the protective layer, it is preferable to include a filler for the purpose of preventing damage to the image after thermal development and ensuring transportability. It is preferable to contain 0.05 to 30% by mass in the composition.

As the filler used in the present invention, S
iO_Two, TiO_Two, BaSO_Four, ZnS, MgCO_Three, Ca
CO_Three, ZnO, CuO, CaO, WS_Two, MoS_Two, M
gO, SnO_Two, Al_TwoO_Three, Α-Fe_TwoO_Three, Α-FeO_Two
H, SiC, CeO_Two, Y_TwoO _Three, ZrO_Two, MoC, B
C, WC, BN, SiN, Andalusite, Silymanai
G, mullite, aluminum borate, titanium carbide,
Corundum, artificial diamond, garnet, garnet
, Silica stone, triboli, diatomaceous earth, smectite, de
Inorganic compounds such as romite, ITO and ATO, polyethylene
Resin particles, fluororesin particles, guanamine resin particles,
Krill resin particles, silicone resin particles, melamine resin particles
And the like.
The shape may be spherical, irregular, needle-like, or
The properties may be non-porous or porous. In addition,
The average particle size of the filler is 0.01 μm to 20 μm (acicular
In this case, the minor axis diameter is preferable), more preferably
It is 0.05 μm to 10.0 μm.

Further, the protective layer may contain a lubricant and an antistatic agent in order to improve the lubricating property and the charging property. Examples of such a lubricant include fatty acids, fatty acid esters, fatty acid amides, polyoxyamides and the like. Examples include ethylene, polyoxypropylene, (modified) silicone oil, (modified) silicone resin, (modified) fluorine compound, (modified) fluorine resin, carbon fluoride, wax and the like. Also,
Examples of the antistatic agent include “11290” such as a cationic surfactant, an anionic surfactant, a nonionic surfactant, a polymer antistatic agent, a metal oxide or a conductive polymer.
Chemical Products ", Chemical Daily, p. Compounds described in 875 to 876 and the like, compounds described in U.S. Pat. No. 5,244,773, columns 14 to 20, and the like can be mentioned.

Further, in the case where the binder resin of the protective layer has a hydroxyl group or active hydrogen within a range not to impair the object of the present invention, conventionally known polyfunctional isocyanate compounds, polyfunctional carbodiimide compounds, alkoxysilane compounds, The film strength may be improved by adding a cross-linking agent such as a metal alkoxide having a plurality of metal alkoxide portions in a molecule such as an alkoxytitanium compound.

The addition amount of these additives is preferably about 0.01 to 20% by mass, more preferably 0.05 to 10% by mass of the protective layer layer forming component.

In the present invention, the protective layer may be a single layer,
It may be composed of a plurality of layers having the same or different compositions. The thickness of the protective layer is usually 1.0 to 5.0 μm.

In the present invention, in addition to the above-mentioned image forming layer, support and protective layer, a backing layer may be provided on the surface of the support opposite to the image forming layer for the purpose of transportability and preventing peeling charging. good.

Such a backing layer is composed of a binder resin and various additives added as necessary. As the binder resin, a resin used in the image forming layer can be selected and used as appropriate. Further, as the additive, an additive used for the protective layer can be appropriately selected and used.

The thickness of the backing layer is usually 0.5
２５25 μm, more preferably 1.0-15 μm. Further, the backing layer may be formed of a single layer, or may be formed of a plurality of layers having different compositions.

Further, as long as the effects of the present invention are not impaired,
An antistatic layer between the support and the backing layer for the purpose of preventing static electricity, and the surface of the support on which the backing layer is laminated, in order to improve adhesion and applicability, are subjected to corona discharge treatment, plasma treatment, and anchor coat treatment. The surface may be modified by using a known surface modification technique.

Further, an adhesive force adjusting layer may be provided to improve the adhesion between the support and the image forming layer, and between the image forming layer and the protective layer. .
0 μm.

The image forming layer, the protective layer, the backing layer, and the optional adhesive strength adjusting layer according to the first, second and third embodiments of the present invention contain the above-mentioned components. Each of them can be formed by dissolving or dispersing in a solvent to prepare a coating solution, coating the solution on a support, and drying.

As the solvent for preparing the coating solution for each layer, the solubility parameter values shown in "Solvent Pocket Book" edited by The Society of Synthetic Organic Chemistry, etc. are 6.0 to 15.
The solvent used in the coating liquid for forming each layer used in the present invention includes, for example, ketones such as acetone, isophorone, ethyl amyl ketone, methyl ethyl ketone, and methyl isobutyl ketone; Alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol; and glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and hexylene glycol; and ether alcohols. As ethylene glycol monomethyl ether, diethylene glycol monoethyl ether and the like,
As ethers, ethyl ether, dioxane, isopropyl ether, etc., as esters, ethyl acetate, butyl acetate, amyl acetate, isopropyl acetate, etc.
Examples of the hydrocarbons include n-pentane, n-hexane, n-heptane, cyclohexane, benzene, toluene, and xylene, and examples of the chlorides include methyl chloride, methylene chloride, chloroform, and dichlorobenzene.

The solvent used in preparing the coating liquid is not limited to these as long as the effects of the present invention are not impaired.

Further, these solvents can be used alone or in combination of several kinds. The content of the solvent in the image forming material can be adjusted by changing conditions such as temperature conditions in a drying step or the like after the coating step, and the total amount of the residual solvent contained in the photothermographic material is 5 to 5. 1000mg /
m ² is preferable, and more preferably, 10 to 300 mg /
m ² .

When dispersion is required when forming a coating solution, a two-roll mill, a three-roll mill, a ball mill, a pebble mill, a cobol mill, a tron mill, a sand mill, a sand grinder, a Sqegvari attritor, a high-speed impeller disperser, a high-speed impeller A conventionally known disperser such as a stone mill, a high-speed impact mill, a disper, a high-speed mixer, a homogenizer, an ultrasonic disperser, an open kneader, a continuous kneader, or the like can be appropriately selected and used.

To apply the coating solution prepared as described above, an extrusion-type extrusion coater,
Timely selection of various known coater stations such as a reverse roll coater, a gravure roll coater, an air doctor coater, a blade coater, an air knife coater, a squeeze coater, an impregnation coater, a bar coater, a transfer roll coater, a kiss coater, a cast coater, and a spray coater. Can be used. Among these coaters, it is preferable to use a roll coater such as an extrusion extrusion coater or a reverse roll coater in order to eliminate the thickness unevenness of the layer.

The coating of the protective layer is not particularly limited as long as the image forming layer is not damaged, but the solvent used in the coating liquid for forming the protective layer may be any of the following. If there is a possibility of dissolving the above, an extrusion type extrusion coater, gravure roll coater, bar coater or the like can be used in the above-mentioned coater station. In addition, when using a coating method such as a gravure roll coater or a bar coater that is in contact with them,
The rotation direction of the gravure roll or bar may be forward or reverse with respect to the transport direction. In the case of forward rotation, a constant speed or a peripheral speed difference may be provided.

Further, as described above, the coating and drying may be repeated for each layer, but the coating and drying may be performed by a multi-layer coating using a wet-on-wet method. In such a case, a reverse roll coater, a gravure roll coater, an air doctor coater, a blade coater, an air knife coater, a squeeze coater, an impregnating coater, a bar coater, a transfer roll coater, a kiss coater, a cast coater, a spray coater, etc. and an extrusion type extrusion coater are used. In the multi-layer coating in such a wet-on-wet system, the upper layer is applied while the lower layer remains wet, so that the adhesiveness between the upper and lower layers is improved. .

Next, a preferred image recording method of the photothermographic material described above will be described in detail. The image recording method of the present invention is roughly classified into three modes depending on the angle between the exposure surface and the laser beam, the wavelength of the laser, and the number of lasers used.
These may be performed alone or in combination of two or more types. By using such an image forming method, a clear image without interference fringes can be obtained.

In the first mode of the image recording method of the present invention, an image is formed by scanning exposure using a laser beam in which the angle between the exposed surface of the photothermographic material and the laser beam does not become substantially perpendicular. Is formed. In this way, by shifting the incident angle from the perpendicular, even if the reflected light at the interlayer interface occurs, the optical path difference reaching the image forming layer increases, so that the scattering and attenuation of the laser light in the optical path are reduced. As a result, interference fringes hardly occur.
Here, “not substantially vertical” means that the angle is closest to vertical during laser scanning, preferably 5 °.
5 degrees or more and 88 degrees or less, more preferably 60 degrees or more and 86 degrees or less, and still more preferably 65 degrees or more and 84 degrees or less.

Further, in the image recording method of the present invention, the second
Is characterized in that an image is formed by scanning exposure using a vertical multi-laser having a non-uniform exposure wavelength. When scanning with such a vertical multi-laser beam having a width in wavelength, compared with a scanning laser beam in a vertical single mode,
The occurrence of interference fringes is reduced. In addition, the vertical multi here means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm or more. There is no particular upper limit on the distribution of the exposure wavelength,
Usually, it is about 60 nm.

Furthermore, a third aspect of the image recording method of the present invention is characterized in that an image is formed by scanning exposure using two or more lasers.

Such an image recording method using a plurality of lasers includes an image writing means of a laser printer or a digital copying machine which writes an image by a plurality of lines in one scan due to a demand for higher resolution and higher speed. This is a technique used and is known, for example, from JP-A-60-166916. This is a method in which a laser beam emitted from a light source unit is deflected and scanned by a polygon mirror to form an image on a photoreceptor via an fθ lens or the like. This is a laser scanning optical system which is basically the same as a laser imager and the like. Device.

The image formation of the laser beam on the photoreceptor in the image writing means of the laser printer or the digital copier is performed from the image formation position of one laser beam for the purpose of writing an image by a plurality of lines in one scan. The image of the next laser beam is shifted by one line. Specifically, the two light beams are close to each other at an interval of several tens of μm on the image plane in the sub-scanning direction, and have a print density of 400 dpi (in the present invention, 1 inch or 2.54 cm per inch). The dot printing density is defined as dpi (dot per inch), and the pitch of the two beams in the sub-scanning direction is 6
3.5 μm, 42.3 μm at 600 dpi. Unlike such a method in which the resolution is shifted by the resolution in the sub-scanning direction, the present invention is characterized in that two or more lasers are condensed on the exposure surface at the same location by changing the incident angle to form an image. In this case, one ordinary laser (wavelength λ [n
m]), the exposure energy on the exposed surface is E
When N lasers used for exposure have the same wavelength (wavelength λ [nm]) and the same exposure energy (En), 0.9 × E ≦ En × N ≦ 1.1 × E It is preferred to be within the range. By doing so, energy is secured on the exposed surface, but the reflection of each laser beam to the image forming layer is reduced because the exposure energy of the laser is low, and the generation of interference fringes is suppressed.

In the above description, the wavelength of the plurality of lasers is set to λ
Although the same one is used, one having a different wavelength may be used. In this case, (λ−30) <for λ [nm]
λ1, λ2,... λn ≦ (λ + 30).

Further, in the image recording methods of the first, second and third aspects described above, the laser used for scanning exposure is generally well known as a ruby laser or Y laser.
He-Ne solid-state lasers such as AG lasers and glass lasers
Laser, Ar ion laser, Kr ion laser, CO ₂
Laser, CO laser, He-Cd laser, N ₂ laser,
Gas lasers such as excimer lasers; InGaP lasers,
AlGaAs laser, GaAsP laser, InGaAs
Laser, InAsP laser, CdSnP ₂ laser, Ga
A semiconductor laser such as an Sb laser; a chemical laser, a dye laser, or the like can be appropriately selected and used according to the intended use. Among these, a semiconductor laser having a wavelength of 700 to 1200 nm is used due to maintenance and the size of a light source. Is preferred.

In a laser used in a laser imager or a laser imagesetter, the beam spot diameter on the exposed surface of a photothermographic material when it is scanned is generally 5 to 75 μm as a short axis diameter. The major axis diameter is in the range of 5 to 100 μm, and the laser beam scanning speed can be set to an optimum value for each photothermographic material by the sensitivity and laser power at the laser oscillation wavelength inherent to the photothermographic material.

[0131]

Example 1 <Preparation of photothermographic material> A coating solution for forming a backing layer was prepared by the following method.

(Preparation of Backing Layer Forming Coating Liquid) Cellulose acetate butyrate (Eastman Chemical Co., CAB381-20) was stirred with 83 g of methyl ethyl ketone.
8.42 g and 0.45 g of a polyester resin (manufactured by Toyobo Co., Ltd., Byron 280) were added and dissolved. 1.03 g of infrared dye 1 was added to the dissolved solution.

Separately, in 4.32 g of methanol, 0.64 g of an F-based surfactant (Surflon S-381 (active ingredient 70%), manufactured by Asahi Glass Co., Ltd.) and an F-based surfactant (Dainippon Ink Industries, Ltd.) Made, Megafag F120K) 0.23g
Was dissolved, and an F-based surfactant solution was added to the solution containing the infrared dye 1, and sufficiently stirred until the infrared dye 1 was completely dissolved. Finally, add 1 to methyl ethyl ketone
% Silica dispersed in a dissolver-type homogenizer (manufactured by WR Grace Co., Ltd., Syloid 64 × 600).
0), 1.78 g of an isocyanate compound (Coronate C-3041, manufactured by Nippon Polyurethane Industry Co., Ltd.) diluted with methyl ethyl ketone and adjusted to a solid content concentration of 20% by mass was added in sequence and stirred to form a backing layer coating. A working solution was prepared.

The above-mentioned coating liquid for forming a backing layer was coated with a blue dye (manufactured by Bayern AG, Ceres Blue RR-J) using a visual transmission density [manufactured by Konica Corporation, PDA-65: 3 decimal places] Colored 157 and 175μm thick
After applying one side of the biaxially stretched polyethylene terephthalate film subjected to a corona discharge treatment (8 W / m ² · min) to a dry film thickness of 3.5 g / m ² by an extrusion coater, It was dried to form a backing layer.

Further, a coating solution for forming an image forming layer and a coating solution for forming a protective layer were separately prepared by the following methods.

(Preparation of Coating Solution for Forming Image Forming Layer) Water 900
7.5 g of ossein gelatin having an average molecular weight of 100,000 per ml
And 10 mg of potassium bromide dissolved at a temperature of 35 ° C.
Was adjusted to 3.0, and then an aqueous solution 37 containing 74 g of silver nitrate.
370 ml of an aqueous solution containing 0 ml and an equimolar ratio of potassium bromide and potassium iodide to silver nitrate and 1 × 10 ⁻⁴ mol of iridium chloride per mol of silver in a molar ratio of (98/2) was pAg
It was added over 10 minutes by the controlled double jet method while maintaining at 7.7. Then 4-hydroxy-6
0.3 g of methyl-1,3,3a, 7-tetrazaindene
Was added, and the pH was adjusted to 5 with NaOH to give an average particle size of 0.06 μm, a coefficient of variation of particle size of 12%, and (10
0) Cubic silver iodobromide grains having an area ratio of 87% were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting treatment, and then 0.1 g of phenoxyethanol was added thereto.
9, and adjusted to a pAg of 7.5 to obtain a photosensitive silver halide emulsion 1.

Separately, behenic acid 11 was added to 4720 ml of pure water.
1.4 g, arachidic acid 83.8 g, stearic acid 5
4.9 g were melted at 80 ° C. Next, while stirring at a high speed, 540.2 m of a 1.5 mol / l sodium hydroxide aqueous solution
After adding 6.9 ml of concentrated nitric acid, the mixture was cooled to 55 ° C. to obtain a fatty acid sodium solution.

The temperature of the above-mentioned fatty acid sodium solution was 55
While maintaining the temperature, the photosensitive silver halide emulsion 1 (containing 0.038 mol of silver) prepared above and 450 ml of pure water were added and stirred for 5 minutes. Next, a 1 mol / l silver nitrate solution 76
0.6 ml was added over 2 minutes, stirred for another 20 minutes, and the water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration are repeated until the conductivity of the filtrate becomes 2 μS / cm, centrifugal dehydration is performed, and then hot air drying is performed at 37 ° C. until there is no loss in mass. I got

Then, polyvinyl butyral resin (Eslec BL-5Z, manufactured by Sekisui Chemical Co., Ltd.) 14.57
g was dissolved in 1457 g of methyl ethyl ketone and, while stirring with a dissolver-type homogenizer, 5
00 g of powdered organic silver salt A was slowly added and mixed well. Then, a media dispersing machine (Gett) filled with 80% of zirconia beads having a particle diameter of 1 mm (manufactured by Toray Industries, Inc.)
zman), a peripheral speed of 13 m, and a residence time in the mill of 0.
The dispersion was carried out for 5 minutes to prepare a photosensitive emulsion dispersion.

Further, 50 g of the above-mentioned photosensitive emulsion dispersion and 10.0 g of methyl ethyl ketone were mixed, and mixed while stirring.
The temperature was kept at 8 ° C, and a methanol solution of antifoggant 1 (1
(1.2%) was added and stirred for 1 hour. Further, a methanol solution of calcium bromide (11.2%) was added to 0.1%.
212 g was added and the mixture was stirred for 20 minutes, and then 0.343 g of a solution obtained by dissolving 1.00 g of dibenzo-18-crown-6 and 0.31 g of potassium acetate in 10.0 g of methanol was added. Stirred for minutes. Next, 4.395 g of the following dye solution 1 was added and stirred for 50 minutes, and then 0.0380 g of a thyuronium compound (exemplified compound 2-7) was added and stirred for 10 minutes. And stirred for another 60 minutes.

(Dye Solution 1) Infrared sensitizing dye 1 0.0086 g Benzoic acid derivative 1 2.476 g Methyl ethyl ketone 25.00 g While keeping the solution to which the dye solution was added at 13 ° C., a polyvinyl butyral resin (Sekisui Chemical Co., Ltd.) Industrial Co., Ltd.
13.29 g and 0.304 g of tetrachlorophthalic acid were added in this order, and sufficiently stirred and dissolved.

To this solution were added 2.261 g, 13.543 g, 3.491 g of the following additive solutions 1, 2, 3, and 4 separately dissolved in methyl ethyl ketone, respectively.
4.597 g of a hindered amine solution dissolved in methyl ethyl ketone at a solid content of 5% was added in the amount shown in Table 1 and stirred to prepare an image forming layer forming coating solution.

(Additive solution 1) Isocyanate compound [Sumitomo Bayern Urethane Co., Ltd., Sumidur N-3300] 5.630 g Potassium p-toluenethiosulfonate 0.415 g Methyl ethyl ketone 20.00 g (Additive solution 2) 1 , 1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 6.070 g 4-methylphthalic acid 0.401 g Infrared dye 1 0.0262 g Methyl ethyl ketone 20.00 g (additive solution 3) Trihalomethyl group-containing compound (Exemplified compound 3-15) 1.543 g 2-phenyl-4,6-bis (trichloromethyl) -s-triazine 1.407 g Methyl ethyl ketone 10.01 g (Additive solution 4) Phthalazine 1. 420g Methyl ethyl ketone 20.00g

[0144]

Embedded image

(Preparation of Protective Layer Forming Coating Solution) While stirring with 86.5 g of methyl ethyl ketone, 10.05 g of cellulose acetate butyrate (CAB1 manufactured by Eastman Chemical Co., Ltd.)
71-15), 0.025 g of benzotriazole, fluorinated activator (Surflon KH40, manufactured by Asahi Glass Co., Ltd.)
0.10 g was added and dissolved.

Separately, a solution of 55.0 g of cellulose acetate butyrate (manufactured by Eastman Chemical Company, CAB171-15) dissolved in methyl ethyl ketone at a solid content of 15% was added to silica (Fuji Silysia Chemical Ltd., Sylysia 320).
Was added and dispersed with a media disperser filled with zirconia beads to prepare a silica dispersion. Next, while stirring the resin solution in which the above-mentioned benzotriazole was dissolved, 3.0 g of a silica dispersion was added, followed by ultrasonic dispersion to prepare a coating liquid for forming a protective layer.

Next, the thickness 17 having the backing layer was formed.
The surface opposite to the backing layer of a biaxially stretched polyethylene terephthalate film of 5 μm was subjected to corona discharge treatment (8 W / m
² min), and the coating liquid for forming an image forming layer and the coating liquid for forming a protective layer prepared by the above-described method are extruded on the corona discharge-treated surface using an extruder to form a multilayer coating. It was dried by air to produce a photothermographic material. The film thickness after drying was 20.0 ± 1.0 g / m ² of the image forming layer,
It was adjusted to be 35 ± 0.12 g / m ² .

<Image Recording Method and Evaluation of Image> The above-mentioned photothermographic material was stored for 120 hours at room temperature under light shielding, and for 120 hours in a thermostatic layer having a temperature and a humidity of 50 ° C. and 55%, respectively. From the protective layer surface side of each material, a wavelength of 800 nm to
An exposure machine using an 820 nm vertical multi-mode semiconductor laser as an exposure source changes the exposure amount and performs exposure by laser scanning, and then uses an automatic developing machine having a heat drum to protect the photothermographic material. The image was recorded by heat development at 126 ° C. for 16 seconds so that the layer and the drum surface were in contact with each other.

In the laser scanning exposure, the angle between the exposed surface of the photothermographic material and the exposed laser beam was 75 degrees, the laser spot diameter on the protective layer surface was 100 μm in the main scanning direction and 75 μm in the sub-scanning direction. Pitch is 10 in main scanning direction
0 μm and 75 μm in the sub-scanning direction.
Using an automatic developing machine having a heat drum having a surface rubber hardness of 70 specified by 253 type A, the protective layer of the photothermographic material is brought into contact with the drum surface at 126 ° C.
For 16 seconds.

The sensitivity, fog density and light fog of the image at the time of light exposure were evaluated according to the following criteria. Table 1 shows the obtained results.

(Image Sensitivity) The transmission density of Visual was measured using a densitometer (X-Rite color transmission densitometer 310).
In the measurement in T), the reciprocal of the ratio of the exposure amount giving a density higher than that of the unexposed portion by 1.0 was obtained, and evaluated by a relative value with the sensitivity of 100 stored at room temperature as 100. The exposure amount at which the density is equal to the unexposed portion +1.0 corresponds to the case where the density is equal to the unexposed portion +0.7 to
Measure at least three points between the concentrations of +1.2,
It was determined by linear regression.

(Image Fogging) Visual of Unexposed Area
1 was measured at 10 points with a densitometer (X-Rite, color transmission densitometer 310T), and the average value was evaluated.

(Light Fogging) The image of the unexposed portion of the photothermographic material stored at room temperature for 120 hours was exposed to light for 24 hours on a shakasten with an inverter having an outside air temperature of 35 ° C. and a surface illuminance of 12,000 lux. Was done.
The transmission densities before and after the light exposure were measured at 10 points by a Visual transmission densitometer (a color transmission densitometer 310T, manufactured by X-Rite), and evaluated by the difference (ΔD) between the average values.

ΔDmin = [Transmission density of Visual before light irradiation] − [Transmission density of Visual after light irradiation]

[0155]

[Table 1]

Example 2 In the preparation of the coating solution for forming an image forming layer in Example 1, an epoxy dissolved in methyl ethyl ketone at a solid content of 10% was used instead of the hindered amine solution dissolved in methyl ethyl ketone at a solid content of 5%. A solution of the compound with the hydrogenated groups is
An image forming material was prepared in the same manner as in Example 1 except that the amounts shown in Table 2 were added.

Next, an image was recorded in the same manner as in Example 1, and the image sensitivity and the image fog were evaluated in the same manner. In addition, a decrease in the density of the high-density portion of the image during light exposure was evaluated according to the following criteria. Table 2 shows the obtained results.

(Decrease in Density) An image having a visual transmission density of 3.0 ± 0.05 before light exposure on a photothermographic material stored at room temperature for 120 hours was taken for 24 hours at an outside air temperature of 40 ° C. and a surface illuminance. Light exposure was carried out by leaving the apparatus on a 10000 lux Shark Sten with an inverter. The transmission density of the visual after light irradiation was measured, and evaluated by the difference (ΔD) of the average value. The transmission densities were 1
The average value was measured for each of the 0 points.

ΔD3.0 = [Transmission density of Visual before light exposure] − [Transmission density of Visual after light exposure]

[0160]

[Table 2]

The compound No. in Table 2 was used. Represents the following compounds. 1: Bisphenol A type epoxy resin [Toto Kasei Co., Ltd.
Additive: Epototh YD-128], a water additive 2: Bisphenol A type epoxy resin [Epicoat 1001, manufactured by Yuka Shell Epoxy Co., Ltd.] 3: Bisphenol A type epoxy resin [Toto Kasei Co., Ltd.]
Additive: Epototh YD-017], a bisphenol A type epoxy resin [Toto Kasei Co., Ltd.]
Additive of Epotote YD-020N] 5: Phenoxy resin [Phenoxy Associates, P
Water additive of KHH] 6: Water additive of novolak type epoxy resin [Epototo YDCN-704 manufactured by Toto Kasei Co., Ltd.] 7: Bisphenol F type epoxy resin [Toto Kasei Co., Ltd.]
8: a water additive of hydrogenated bisphenol A type epoxy resin [Epototo ST-3000, manufactured by Toto Kasei Co., Ltd.].

Example 3 A method similar to that of Example 1 was used except that a hindered amine solution having a solid content of 5% and dissolved in methyl ethyl ketone was not used in the preparation of the coating solution for forming an image forming layer of Example 1. To prepare an image forming coating solution.

In the preparation of the coating liquid for forming a protective layer in Example 1, the resin solution in which benzotriazole was dissolved was added
The compound solution obtained by hydrogenating the epoxy group dissolved in methyl ethyl ketone at a solid content of 10% and the amount shown in Table 3 and 3.0 g of the silica dispersion prepared in Example 1 were sequentially added and stirred.
Finally, ultrasonic dispersion was performed to prepare a coating liquid for forming a protective layer.

An image forming material was prepared in the same manner as in Example 1 except that the above-mentioned image forming coating liquid and protective layer forming coating liquid were used.

Next, an image was recorded by the same method as in Example 1, and the sensitivity of the image and the fog of the image were evaluated by the same method. Further, the decrease in the density of the high-density portion of the image at the time of light exposure was evaluated based on the same criteria as in Example 2. Table 3 shows the obtained results.

[0166]

[Table 3]

The compound No. in Table 3 was used. Represents the following compounds. 2: Water additive of bisphenol A type epoxy resin [Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.] 4: Bisphenol A type epoxy resin [Toto Kasei Co., Ltd.]
Additive of Epotote YD-020N] 5: Phenoxy resin [Phenoxy Associates, P
KHH].

Example 4 In the preparation of the coating solution for forming an image forming layer in Example 1, instead of the hindered amine solution dissolved in methyl ethyl ketone at a solid content of 5%, it was dissolved in methyl alcohol at a solid content of 5%. An image forming material was prepared in the same manner as in Example 1, except that the amount of the compound solution having a sulfonic acid group shown in Table 4 was added.

Next, an image was recorded in the same manner as in Example 1, and the sensitivity of the image and the fog of the image were evaluated in the same manner. Further, the color tone change of the image at the time of light exposure was evaluated according to the following criteria. Table 4 shows the obtained results.

(Color tone change) An image in which the visual transmission density of the photothermographic material stored at room temperature for 120 hours before light exposure was 1.0 ± 0.05 before exposure to light, the outside air temperature was 30 ° C., and the surface illuminance was 24 hours After leaving it on a 10000 lux inverter-equipped sherka sten for light exposure,
An image having a transmission density of 1.0 ± 0.05 is measured,
The degree of yellowing of silver tone was evaluated according to the following criteria. The transmission density was an average value measured at 10 points each.

ΔB = [Transmission density of Blue after light exposure (Transmission density of Visual after light exposure 1.0 ± 0.0
5)]-[Transmission density of Blue before light irradiation (Vis before light irradiation)
ua transmission density 1.0 ± 0.05)] As a comparison, an image forming coating liquid to which no thiuronium compound was added was prepared as follows.

In the preparation of the coating solution for forming an image forming layer in Example 1, instead of adding 4.395 g of Dye Solution 1, 4.000 g of the following Dye Solution 2 was added and stirred for 60 minutes. The temperature was reduced to 13 ° C. and stirred for a further 60 minutes.
To this solution, 2.261 g, 13.543 g, 3.491 g, and 4.51 g of additive solutions 1, 2, 3, and 4 of Example 1 separately dissolved in methyl ethyl ketone, respectively.
97 g of the mixture was stirred with stirring, and finally a compound having a sulfonic acid group dissolved in methyl alcohol at a solid content of 5% was added in the amount shown in Table 4 and stirred to prepare a coating solution for forming an image forming layer. .

(Dye Solution 2) Infrared Sensitizing Dye 1 0.0103 g Benzoic acid derivative 1 4.245 g 2-Chlorobenzoic acid 0.568 g Methyl ethyl ketone 25.00 g

[0174]

[Table 4]

The compound No. in Table 4 was used. Represents the following compounds. 9: p-toluenesulfonic acid 10: p-xylene-2-sulfonic acid 11: 2-naphthalenesulfonic acid 12: 3-pyridinesulfonic acid 13: 2- (N-morpholino) ethanesulfonic acid.

Example 5 A method similar to that of Example 1 was used, except that a hindered amine solution having a solid content of 5% and dissolved in methyl ethyl ketone was not added in the preparation of the coating solution for forming an image forming layer of Example 1. To prepare an image forming coating solution.

In the preparation of the coating liquid for forming a protective layer in Example 1, the resin solution in which benzotriazole was dissolved was added
A compound solution having a sulfonic acid group dissolved in methyl alcohol at a solid content of 5% was added in an amount shown in Table 5 and 3.0 g of the silica dispersion prepared in Example 1 were sequentially added and stirred, and finally ultrasonically dispersed. Thus, a coating liquid for forming a protective layer was prepared.

An image forming material was prepared in the same manner as in Example 1 except that the above-mentioned image forming coating liquid and protective layer forming coating liquid were used.

Next, an image was recorded by the same method as in Example 1, and the sensitivity of the image and the fog of the image were evaluated by the same method. Further, the color tone change of the image at the time of light exposure was evaluated based on the same criteria as in Example 4. Table 5 shows the obtained results.

[0180]

[Table 5]

In Table 5, Compound No. Represents the following compounds. 9: p-toluenesulfonic acid 10: p-xylene-2-sulfonic acid 11: 2-naphthalenesulfonic acid.

Example 6 The same automatic developing machine as in Example 1 was used, except that the photothermographic materials shown in Table 6 were image-exposed by the following image recording method from the photothermographic materials prepared in Examples 1 to 5. Using,
An image was formed by heat development at 126 ° C. for 16 seconds. The interference fringes of the obtained image were evaluated by sensory evaluation and density measurement (ΔD) according to the following criteria. Table 6 shows the obtained results.
In addition, the exposure amount was adjusted so as to be the same as the exposure energy on the protective layer surface in Example 1.

<Image recording method 1> Exposure was performed by laser scanning from the protective layer side of the photothermographic material with an exposure machine using a semiconductor laser of 820 nm wavelength as an exposure source. At this time, the angle between the exposed surface of the photothermographic material and the exposed laser beam is set to 9
The image was exposed at an angle of 0 degree.

<Image Recording Method 2> Exposure was performed by laser scanning from the protective layer side of the photothermographic material with an exposure machine using a semiconductor laser of 820 nm wavelength as an exposure source. At this time, the angle between the exposed surface of the photothermographic material and the exposed laser beam is set to 7
Image exposure was performed at 0 degree.

<Image recording method 3> From the protective layer side of the photothermographic material, a wavelength of 800 nm to 820 nm was superposed by high frequency superposition.
Exposure was performed by laser scanning using an exposing machine using a semiconductor laser having a vertical multi-mode of m as an exposure source. At this time, the angle between the exposed surface of the photothermographic material and the exposed laser beam is set to 9
Image exposure was performed at 0 degree.

<Image recording method 4> From the protective layer side of the photothermographic material, two semiconductor lasers having a wavelength of 820 nm were used as exposure sources, and two laser beams emitted at the same time were deflected and scanned by a polygon mirror, and the fθ lens was scanned. Exposure by laser scanning was performed using an exposure machine configured to condense light on the photothermographic material through the light source. At this time, image exposure was performed by setting the angle between the exposed surface of the photothermographic material and the exposed laser beam to 85 ° for one laser beam and 95 ° for the other laser beam. The energy intensity of each laser beam on the exposed surface was the same, and the energy intensity was の of the intensity of the image recording method 1, respectively.

(Sensory evaluation) Permeation density is 1.80 ± 0.1
The image exposed and heat-developed to have a luminance of 1
A sample was placed on a 0000-square caster, and the degree of occurrence of interference fringes was ranked as shown below, and the sensory evaluation was performed. 4: No interference fringes are observed. 3: Very slight interference fringes are observed. 2: Interference fringes are clearly recognized partially. 1: Interference fringes are clearly observed on the entire surface.

(Density measurement (ΔD)) By scanning and measuring the density of the image portion using a densitometer capable of narrowing the slit opening, if the interference fringe pattern is clear, the light fringe and dark fringe are interposed. Can be quantitatively evaluated as the difference in the transmission density of Therefore, the transmission density is 1.80 ± 0.
The image exposed and heat-developed to be 15 was measured at a measurement interval of 25 with a microdensitometer (manufactured by Konica Corporation, Konica Microdensitometer PDM-7 type BR).
μm, measured at 5 points with a measurement length of 20 mm (total number of measurement points: 40
00 points), and the sensory evaluation described above was associated with the difference ΔD in concentration. The smaller the ΔD, the less the occurrence of interference fringes.

ΔD = (maximum density at measurement point) − (minimum density at measurement point)

[0190]

[Table 6]

[0191]

According to the present invention, it has been possible to provide a photothermographic material having a small image density fluctuation with respect to light, and to provide a suitable image recording method using the photothermographic material.

Claims (11)

[Claims] 1. A photothermographic material in which an image forming layer and a protective layer containing at least an organic silver salt, a photosensitive silver halide and a reducing agent are laminated on a support in this order, selected from the image forming layer and the protective layer. A photothermographic material, wherein at least one of the layers contains a hindered amine. 2. The ratio of hindered amine contained in at least any one layer selected from the image forming layer and the protective layer to the total composition of the image forming layer and the protective layer is 0.
2. The composition according to claim 1, wherein the content is 45 to 2.50% by mass.
The photothermographic material according to the above. 3. A photothermographic material in which an image forming layer and a protective layer containing at least an organic silver salt, a photosensitive silver halide and a reducing agent are laminated on a support in this order, selected from the image forming layer and the protective layer. A photothermographic material, characterized in that at least one of the layers contains a compound obtained by hydrogenating an epoxy group. 4. The ratio of a compound obtained by hydrogenating an epoxy group contained in at least one layer selected from the image forming layer and the protective layer to the total composition of the image forming layer and the protective layer is 0.50. The photothermographic material according to claim 3, wherein the amount is from 5.00% by mass to 5.00% by mass. 5. The photothermographic material according to claim 1, wherein the image forming layer contains a thiuronium compound. 6. A photothermographic material in which an image forming layer and a protective layer containing at least an organic silver salt, a photosensitive silver halide and a reducing agent are laminated on a support in this order, selected from the image forming layer and the protective layer. A photothermographic material, wherein at least one of the layers contains a compound having a sulfonic acid group, and the image forming layer contains a thiuronium compound. 7. The ratio of the compound having a sulfonic acid group contained in at least one selected from the image forming layer and the protective layer to the total composition of the image forming layer and the protective layer is 0.06 to 0. 7. The photothermographic material according to claim 6, wherein the content is 0.4% by mass. 8. The scanning exposure of the photothermographic material according to claim 1 using a laser in which an angle between an exposure surface and a laser beam does not become substantially perpendicular. An image recording method, comprising: 9. An image recording method, wherein the photothermographic material according to claim 1 is subjected to scanning exposure using a vertical multi-laser having a non-uniform exposure wavelength. 10. An image recording method, comprising subjecting the photothermographic material according to claim 1 to scanning exposure using two or more lasers. 11. The wavelength of a laser used for scanning exposure is 70.
8. The light emitting device according to claim 8, wherein the thickness is from 0 to 1200 nm.
0. The image recording method according to any one of 0.