JP2001312027A - Heat developable photosensitive material and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photographic sensitive material having high sensitivity, less liable to fog, nearly free of fogging and a sensitivity change in storage, nearly free of fogging, a change of fog density and the deterioration of a color tone particularly due to printout and ensuring good image stability after printout and to provide an image forming method using the sensitive material. SOLUTION: The heat developable photosensitive material has a photosensitive layer containing at least a) an organic silver salt, b) photosensitive silver halide, c) a reducing agent and d) a halogen compound of formula (1a), (1b) or (1c) on the base and contains an isocyanate compound. In the image forming method, the photosensitive material is exposed with a laser and developed by heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material for forming an image by thermal development and an image forming method using the same, and more particularly to a technique for improving fog of an image to be formed.

[0002]

2. Description of the Related Art In recent years, in the field of printing plate making and medical treatment, a waste liquid accompanying wet processing of an image forming material has become a problem in terms of workability. There is a strong demand for weight loss. Therefore, there is a need for a technique relating to a photothermographic material capable of performing efficient exposure with a laser imagesetter and forming a high-resolution, clear black image. As this kind of technology, for example, US Pat. No. 3,152,904,
No. 3,487,075 and D.C. Morgan
n) "Dry Silver Photographic Material (Dry Sil)
ver Photographic Material
s) "(Handbook of Imaging M
materials, Marcel Dekker, I
nc. 48, 1991) are known. Since these photosensitive materials are usually developed at a temperature of 80 ° C. or higher, they are called heat developing materials.

[0003] Such heat-developable materials usually contain 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 dispersed in an organic binder matrix. However, it is stable at room temperature, but generates silver by an oxidation-reduction reaction between a reducible silver source (acting as an oxidizing agent) and a reducing agent when heated to a high temperature after exposure. This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas and results in the formation of an image.

However, the above heat-developable material has a disadvantage that undesired silver is formed on a white background portion having no image and fog is formed. As a technique for suppressing the fogging of the image, a method using various halogen compounds has been proposed, for example, US Pat. No. 3,874,946.
Nos. 4,459,350 and 5,340,712
Nos. 4,756,999 and 5,594,143
No. 5,594,143, JP-A-58-59439.
Nos. 59-46641 and 59-57233.

JP-A-6-208193 discloses a photothermographic emulsion in which a compound having an isocyanate group and a halogenated antifoggant are used in combination as means for improving fog stability during storage.

[0006] However, the above technique is not sufficient in fogging prevention effect or has a high fogging prevention effect. Further, when the photographic material is stored and aged, there is a problem that fog increases and sensitivity fluctuates. further,
After development, fog rise (printout) that occurs when exposed to room light or sharksten light, printout density fluctuation during exposure, color tone deterioration due to printout, or the temporal stability of the image after printout is not yet achieved. Was enough. Further, there is a disadvantage that fogging increases when conditions are strengthened, such as raising the developing temperature in order to shorten the developing time, and the development of an antifogging agent free of such a problem has been desired.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-sensitivity and low fog generation, to suppress fog generation and sensitivity fluctuation during storage, and particularly to suppress fog density and its fluctuation and color tone deterioration due to printout. It is another object of the present invention to provide a heat-developable photographic light-sensitive material having improved image stability after printout and improved fogging when conditions are strengthened, such as raising the developing temperature.

[0008]

The structure of the present invention for solving the above-mentioned problems of the present invention is as follows. (1) At least a) an organic silver salt, b) a photosensitive silver halide, c) a reducing agent, and d) a general formula (1a) on a support.
A photothermographic material comprising a photosensitive layer containing a halogen compound represented by the formula: (2) At least a) an organic silver salt, b) a photosensitive silver halide, c) a reducing agent, and d) a general formula (1b) on a support.
A photothermographic material comprising a photosensitive layer containing a halogen compound represented by the formula: (3) On a support, at least a) an organic silver salt, b) photosensitive silver halide, c) a reducing agent, and d) a compound of the general formula (1c)
A photothermographic material comprising a photosensitive layer containing a halogen compound represented by the formula: (4) The photothermographic material according to the above (1), (2) or (3), further comprising an isocyanate compound. (5) The photothermographic material according to the above (4), wherein the isocyanate compound is a polyisocyanate compound. (6) An image forming method comprising subjecting the photothermographic material according to any one of the above (1) to (4) to laser exposure and heat development.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The compound represented by formula (1a) or (1b) will be described.

[0010]

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In the general formulas (1a) and (1b), X ₁ , X ₂ and X ₃ represent a hydrogen atom or an arbitrary substituent, and at least one of X ₁ , X ₂ and X ₃ is a halogen atom. It is. The halogen atom is F, Cl, Br, I,
When two or more are substituted, they may be the same or different.
Preferably it is Cl or Br, more preferably Br
It is.

The substituents other than the halogen atom are optional, but are preferably alkyl, alkenyl, aryl, alkoxy, acyl, alkoxycarbonyl, aryloxy, aryloxycarbonyl,
Carbamoyl group, sulfamoyl group, acyloxy group,
Acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group,
Examples include a ureido group, a phosphoric acid amide group, a sulfinyl group, a hydroxy group, and a heterocyclic group. Of these,
Electron-withdrawing group, ie, a trihalomethyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,
A carbamoyl group, a sulfamoyl group and the like are preferable. Particularly preferably, all of X ₁ , X ₂ and X ₃ are halogen atoms, and more preferably, all of X ₁ , X ₂ and X ₃ are Br.

Y ₁ and Y ₂ are —N (R ₁ ) —, a sulfur atom,
Oxygen atom, a selenium atom or _{- (R 2) C = C} (R 3) - represents, Y ₂ is a single bond to the other. R ₁ , R ₂ and R ₃ each represent a hydrogen atom or an arbitrary substituent, and the substituent is preferably —N (R ₁ ) —, an oxygen atom and a vinyl group. When Y ₁ is —N (R ₁ ) —, R ₁ is preferably an alkyl group, more preferably R and R ₁ form an alicyclic group.

R represents a hydrogen atom, a halogen atom or a substituted or unsubstituted aliphatic group, preferably an aliphatic group.

When R is an aliphatic group, an alkyl group is preferred.
And the aliphatic group is represented by the above general formula (1a) or (1)
-Y as described in b)₁− (L₁) N1-CX₁
X_TwoX _ThreeGroup or -Y_Two-L_Two-CX₁X_TwoX_ThreePlace with group
Is preferred. In this case, the general formula (1a)
Is -Y₁− (L₁) N1-CX₁X_TwoX_ThreeIf the group
Is preferable, and in the general color (1b), -Y_Two-L_Two-C
X₁X_TwoX_ThreeIs preferred.

When R is an aliphatic group, it is also preferred that the aliphatic group has a plurality of (preferably 2 to 4 in total) the above two groups. In this case, in a general color _{(1a) -Y 1 - (L} 1) n1-C
X ₁ X ₂ X ₃ groups are preferred, and in general color (1b),-
_{Y 2 -L 2 -CX 1 X 2} X 3 group is preferred.

Here, Y ₁ , L ₁ , n 1, X ₁ , X ₂ ,
X ₃ , Y ₂ and L ₂ are the general colors (1a) and (1b), respectively.
Is synonymous with

L ₁ represents a sulfonyl group, and L ₂ represents a carbonyl group or a sulfinyl group. The sulfonyl group of L ₁ is more preferable than the carbonyl group or sulfinyl group of L ₂ . n1 represents 0 or 1, but is preferably 1.

Next, the compound represented by formula (1c) will be described.

[0020]

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In the general formula (1c), X ₁ , X ₂ and X
_{3 and} R have the same meanings as in formula (1a) or (1b), and R is preferably an aliphatic group.

When R is an aliphatic group, an alkyl group is preferable, while the aliphatic group is preferably the same as defined in the above formula (1c), ie, -Y _2- (L ₃ ) n 2 -CX ₁ X ₂ It is preferred to have an X ₃ group.

When R is an aliphatic group, it is also preferred that the aliphatic group has a plurality (preferably 2 to 4) of the above groups in the aliphatic group.

Here, Y ₂ , n 2, X ₁ , X ₂ , X ₃ , L ₃
Are the same as those in the general color (1c).

[0025] Y ₂ has the same meaning as Y ₂ in the general formula (1b).
Y ₂ is preferably —N (R ₁ ) —, an oxygen atom and a vinyl group. When Y ₂ is —N (R ₁ ) —, R ₁ is preferably an alkyl group, and more preferably R and R ₁ form an alicyclic group. L ₃ represents a sulfonyl group, a carbonyl group or a sulfinyl group, and is preferably a sulfonyl group. n2 represents 2 or 3, and is preferably 2.

The halogen compounds represented by the general formulas (1a) to (1c) can have a ballast group. The ballast group as referred to herein means a total carbon number of 8 or more, preferably 8 to 1
00, more preferably 8 to 60, even more preferably 10 to
A substituent having a size corresponding to 40. As the ballast group, preferably, an aliphatic hydrocarbon group (for example, an alkyl group, an alkenyl group, an alkynyl group, etc.), an aryl group, a heterocyclic group, and an ether group, a thioether group, a carbonyl group, an amino group, or a sulfonyl group are used. And a group comprising a combination with a group such as a phosphonyl group. Also, the ballast group may be a polymer. As a specific example of the ballast group, for example, Research Disclosure 199 (Research Disclosure)
5/2, 37938, pp. 82-89, JP-A-1-28
Nos. 0747 and 1-283548. Preferably, the ballast group has a total carbon number of 7 to
50, more preferably 10 to 30. The ballast group is represented by Y ₁ or Y ₂ in the general formulas (1a) to (1c).
Represents a substituent represented by R ₁ , R ₂ and R _{3 in} —N (R ₁ ) —, — (R ₂ ) C ＝ C (R ₃ ) —, an aliphatic group represented by R, X ₁ , X ₂ and It can be added as a substituent represented by X ₃ .

Next, specific examples of the compounds represented by the general formulas (1a) to (1c) are shown below, but the present invention is not limited thereto.

[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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The compounds of the general formulas (1a) to (1c) are used in an amount of 10 ^{-5 to} 1 mol, preferably 10 ^-4 to 10 ^-2 , based on 1 mol of silver atoms contained in silver halide and organic silver.
It is preferable to include it in the mol photosensitive layer.

The methods for synthesizing the compounds of the general formulas (1a) to (1c) of the present invention are known, and are described, for example, in US Pat.
892,743 can be referred to.

Next, a synthesis example of the halogen compound of the present invention will be described.

Synthesis of Exemplified Compound (1a-1) The compound was synthesized by the method described in US Pat. No. 3,892,743.

Synthesis of Exemplified Compound (1a-14) 2.1 g of cyclohexylmethanesulfonate and 5 g of glacial acetic acid
0 ml and 12.0 g of sodium acetate were sequentially mixed, and the solution was stirred at room temperature, and 11.7 g of bromine was added dropwise. After dropping,
After stirring at 100 ° C. for 5 hours, the reaction solution was returned to room temperature and poured into 250 ml of water. The obtained crystals were collected by filtration and separated and purified by silica gel column chromatography (yield 1.2 g, 25%).

Synthesis of Exemplified Compound (1b-1) To 1.8 g of piperidine was added 10 ml of toluene, and the mixture was cooled in an ice bath. Under cooling, the solution was stirred, and 3.1 g of tribromoacetyl chloride dissolved in 10 ml of toluene was added dropwise. After completion of the dropwise addition, the mixture was stirred for 2 hours, then the reaction solution was returned to room temperature, and 50% of a 10% aqueous sodium hydrogen carbonate solution was added. Extract with 50 ml of ethyl acetate,
The ethyl acetate layer was washed successively with 50 ml of 1 mol / L hydrochloric acid and 50 ml of 25% saline, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The resulting solid was recrystallized from 50 ml of n-hexane to give the exemplified compound (1b).
-1) was obtained (2.8 g, 80% yield).

The photothermographic material of the present invention preferably contains an isocyanate compound in combination with the halogen compound of the present invention, since the object of the present invention can be more highly achieved. As the isocyanate compound, a compound represented by the following general formula (IC) is preferably exemplified.

General formula (IC) (O = C = N-) v
L In the general formula (IC), v represents an integer of 1 to 11,
Preferably it is an integer of 3 to 5. L represents a v-valent linking group bonded to the N atom of the isocyanate group. As L,
For example, an alkylene group, an alkenylene group, an arylene group,
Examples thereof include an alkylarylene group and an isocyanuric acid residue. The aryl ring of the arylene group may have a substituent, and preferred substituents are selected from a halogen atom (for example, a bromine atom or a chlorine atom), a hydroxyl group, an amino group, a carboxyl group, an alkyl group and an alkoxy group. Groups.

As the isocyanate compound, an isocyanate compound having at least two isocyanate groups (including an adduct thereof) is preferable. Specifically, aliphatic diisocyanates, aliphatic diisocyanates having a cyclic group, benzene diisocyanate, naphthalene diisocyanate, biphenyl isocyanate, diphenylmethane diisocyanate, triphenylmethane diisocyanate, triisocyanate, tetraisocyanate, these And adducts of these isocyanates with divalent or trivalent polyalcohols. Particularly preferred are aliphatic polyisocyanates, particularly aliphatic polyisocyanates having a cyclic group.

The following isocyanate compounds are preferably used in the present invention.

Ethane diisocyanate, butane diisocyanate, hexane diisocyanate, 2,2-dimethylpentane diisocyanate, 2,2,4-trimethylpentane diisocyanate, decane diisocyanate;
ω, ω′-diisocyanate-1,3-dimethylbenzol, ω, ω′-diisocyanate-1,2-dimethylcyclohexane diisocyanate, ω, ω-diisocyanate-1,4-diethylbenzol, ω, ω′-diisocyanate-1 , 5-dimethylnaphthalene, ω, ω '
Diisocyanate-n-propylbiphenyl, 1,3
-Phenylene diisocyanate, 1-methylbenzol-2,4-diisocyanate, 1,3-dimethylbenzol-2,6-diisocyanate, naphthalene-1,4
-Diisocyanate, 1,1'-dinaphthyl-2,2 '
Diisocyanate, biphenyl-2,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, 2,2'-dimethyldiphenylmethane
4,4'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate,
4'-diethoxydiphenylmethane-4,4'-diisocyanate, 1-methylbenzol-2,4,6-triisocyanate, 1,3,5-trimethylbenzene-
2,4,6-triisocyanate, diphenylmethane-
2,4,4'-triisocyanate, triphenylmethane-4,4 ', 4'-triisocyanate, tolylene diisocyanate, 1,5-naphthylene diisocyanate
G; dimer or trimer adducts of these isocyanates (for example, 2 mol of adduct of hexamethylene diisocyanate, 3 mol of adduct of hexamethylene diisocyanate, 2 mol of adduct of 2,4-tolylene diisocyanate, 2,4 Adduct of 3 moles of tolylene diisocyanate); adducts of two or more different isocyanates selected from these isocyanates; and diisocyanates and divalent or trivalent polyalcohols (preferably having 20 carbon atoms) Adducts with ethylene glycol, propylene glycol, pinacol, trimethylolpropane, etc. (eg, adducts of tolylene diisocyanate and trimethylolpropane; hexamethylene diisocyanate and trimethylolpropane) Such as the adduct of Chi roll propane)
And the like. Among them, trimers of hexamethylene diisocyanate (1,3,5-triisocyanatohexyl isocyanuric acid) are most preferred.

In the present invention, the isocyanate compound may be contained in the support of the photothermographic material and in any portion on the photosensitive layer side on the support. For example, a support (especially when the support is paper, can be included in the size composition), a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer, an undercoat layer, etc. It can be added to any layer, and can be added to one or more of these layers.

The amount of the isocyanate compound to be added is preferably 0.01 to 20% by mass relative to the total mass of the photosensitive layer.
More preferably, it is 0.5 to 5% by mass.

Examples of commercially available isocyanate compounds are shown below, but the present invention is not limited thereto. Examples include aliphatic, aromatic and polymeric isocyanates.

IC-1 Desmodu
r) N100, Mobay, aliphatic isocyanate IC-2 Desmodu N3300, Mobay, aliphatic isocyanate IC-3 Mondur TD-80, Mobay, aromatic isocyanate IC-4 Mondue M, Mobay, aromatic Isocyanate IC-5 Montdue MRS, Mobay, Polymer Isocyanate IC-6 Desmodu W, Mobay, Aliphatic Isocyanate IC-7 Papi 27, Dow, Polymer Isocyanate IC-8 Isocyanate T1890, Huls (Hu)
els), aliphatic isocyanate IC-9 octadecyl isocyanate, Aldrich, aliphatic isocyanate The photosensitive silver halide contained in the photosensitive layer of the present invention will be described. The photosensitive silver halide functions as an optical sensor. In the present invention, the average grain size of the photosensitive silver halide grains is preferably small, and the average grain size is 0.1 μm or less, in order to suppress white turbidity after image formation and obtain good image quality. Preferably,
More preferably 0.01 to 0.1 μm, especially 0.02 to
0.08 μm is preferred. The particle size here means
Refers to the diameter (equivalent circle diameter) of a circle having an area equal to that of an individual particle image observed with an electron microscope. The photosensitive silver halide is preferably monodispersed. The term “monodisperse” as used herein means that the coefficient of variation of the particle size distribution determined by the following equation is 40% or less. The coefficient of variation is more preferably at most 30%, particularly preferably at most 20%.

Coefficient of variation of grain distribution = {(standard deviation of grain diameter) / (average of grain diameter)} × 100 The shape of the photosensitive silver halide grains is not particularly limited, but the Miller index (100) plane Is preferably high, and this ratio is preferably at least 50%, more preferably at least 70%, particularly preferably at least 80%. The ratio of the Miller index (100) plane is (11) in the adsorption of the sensitizing dye.
T.1 using the adsorption dependency between the (1) plane and the (100) plane. T
ani, J .; Imaging Sci. , 29,165
(1985).

Another preferred form of silver halide is tabular grains. The term “tabular grain” as used herein means that the thickness in the vertical direction is hμm, where the square root of the projected area is the particle diameter rμm.
Means that the aspect ratio = r / h is 3 or more. 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 0.01 to 0.08 μm. Such tabular grains are described in U.S. Pat. Nos. 5,264,337, 5,314,798, and 5,320,958, and can easily obtain desired tabular grains. Can be.

The halogen composition of the photosensitive silver halide is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. Good. The light-sensitive silver halide emulsion used in the present invention is a P.I. Gla
Chimieet Physique by fkides
Photographique (Paul Monte)
l, 1967); F. Duffin's Ph
autographic Emulsion Chemi
story (published by The Focal Press, 196)
6 years). L. Ma by Zelikman et al
King and Coating Photogra
phy Emulsion (TheFocal Pr
ess, 1964) and the like. That is, any of an acidic method, a neutral method, an ammonia method and the like may be used, and the formation of reacting a soluble silver salt and a soluble halide is performed using any one of a one-side mixing method, a double-mixing method, a combination thereof and the like. Is also good.

The photosensitive silver halide used in the present invention preferably contains metal ions belonging to groups 6 to 11 of the periodic table. Examples of the metal of the metal ion include W, Fe, Co, Ni, Cu, Ru, Rh, Pd,
It is preferably at least one selected from Re, Os, Ir, Pt and Au.

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

Formula [ML ₆ ] ^{m In the} above formula, 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 Represents 4-. Specific examples of the ligand represented by L include:
Halides (fluoride, chloride, bromide and iodide),
Examples include cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide, and aquo ligands, nitrosyl, thionitrosyl, and the like, and 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. Particularly preferred specific examples of M include rhodium (Rh), ruthenium (Ru), rhenium (Re),
Iridium (Ir) and osmium (Os).

The following are specific examples of the transition metal complex ions.

[0055] 1: [RhCl _6] ^3- 2: [RuCl _6] ^3- 3: [ReCl _6] ^3- 4: [RuBr _6] ^3- 5: [OsCl _6] ^3- 6: [IrCl _6] ^{4 -} 7: [Ru (NO) Cl _5] ^2- 8: [RuBr ₄ (H ₂ O)] ^2- 9: _{[Ru (NO) (H 2 O} ) Cl 4 ] ^- 10: [RhCl ₅ (H ₂ O)] ^2-11 : [Re (NO) Cl ₅ ] ^2-12 : [Re (NO) (CN) ₅ ] ^2-13 : [Re (NO) Cl (CN) ₄ ] ^2-14 : [Rh (NO) ₂ Cl _4] ^- 15: _{[Rh (NO) (H 2 O} ) Cl 4 ] ^- 16: [Ru (NO) (CN) _5] ^2- 17: [Fe (CN) _6] ^3- 18 : [Rh (NS) Cl _5] ^2- 19: [Os (NO) Cl _5] ^2- 20: [Cr (NO) Cl _5] ^2- 21: [Re (NO) Cl _5] ^- 22: [Os (NS) Cl ₄ (TeCN)] ^2- 23: [Ru (NS) Cl _5] ^2- 24: _{[Re (NS) Cl 4 (SeCN} ) ] ^2- 25: [Os (NS) Cl (SCN) 4 ] ^2- 26: [Ir (NO ) Cl ₅ ] ^2-27 : [Ir (NS) Cl ₅ ] ^2- These metal ions, metal complexes or metal complex ions may be of one kind or a combination of two or more of the same and different metals. Is also good. The content of these metal ions, metal complexes or metal complex ions, generally is suitably 1 × 10 ^-9 ~1 × 10 ^-2 mol per mol of silver halide, preferably 1 × 10 ^{- It is 8} to 1 × 10 ^-4 mol.

The compounds providing these metals are preferably added during silver halide grain formation and incorporated into silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, physical ripening, and chemical ripening are carried out. 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 uniformly contained 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 of adding an aqueous solution of a powder or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or a method in which 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 a metal ion or a complex ion in advance at the time of preparing 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.

At the time of addition to the particle surface, a required amount of an aqueous solution of a metal compound may 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. However, 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 photosensitive silver halide grains used in the present invention are preferably chemically sensitized. As a preferred chemical sensitization method, a sulfur sensitization method, a selenium sensitization method, and a tellurium sensitization method are well known in the art. Also, a noble metal sensitization method or a reduction sensitization method of a gold compound, platinum, palladium, iridium compound or the like can be applied.

As the compounds preferably used in the sulfur sensitization method, selenium sensitization method, and tellurium sensitization method, known compounds can be used, and compounds described in JP-A-7-128768 and the like can be used. it can. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, and P = Te Compounds having a bond, tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond, Te heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and 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, for example, ascorbic acid, thiourea dioxide and the like.
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.

For the photosensitive layer of the photothermographic material of the present invention, for example, JP-A-63-159814 and JP-A-60-140335
No. 63-231437, No. 63-296551
No. 63-304242, No. 63-15245,
U.S. Pat. Nos. 4,639,414 and 4,740,4
No. 55, No. 4,741,966, No. 4,751,
No. 175 and No. 4,835,096. Useful sensitizing dyes for use in the present invention include, for example, Research Disclosure I
tem 17643 IV-A (December 1978, p. 23). 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, for an argon ion laser light source,
0-162247, JP-A-2-48635, U.S. Pat. No. 2,161,331, West German Patent 936,071.
, Simple merocyanines and helium neon laser light source described in Japanese Patent Application No. 3-189532,
Trinuclear cyanine dyes disclosed in JP-A-50-62425, JP-A-54-18726 and JP-A-59-102229;
For merocyanines, LED light sources and infrared semiconductor laser light sources described in Japanese Patent Application Nos. 6-103272, JP-B-48-42172, JP-B-51-9609, and JP-A-51-9609.
JP-A-5-39818, JP-A-62-284343 and JP-A-2-105135 disclose the thiacarbocyanines and infrared semiconductor laser light sources disclosed in JP-A-59-1.
No. 91032, tricarbocyanines described in JP-A-60-80841, JP-A-59-192242,
General formulas (IIIa) and (II) of JP-A-3-67242.
Dicarbocyanines containing a 4-quinoline nucleus described in Ib) are advantageously selected. Further, when the wavelength of the infrared laser light source is 750 nm or more, more preferably 800 nm or more, in order to cope with a laser in such a wavelength range, Japanese Patent Application Laid-Open Nos. 4-182439 and 5-341432.
No. 6-52387, No. 3-10931, U.S. Pat. No. 5,441,866, JP-A-7-13295
Sensitizing dyes described in Nos. 1 to 3 are preferably used.
These sensitizing dyes may be used alone, and a combination of sensitizing dyes is often used particularly for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization.

In the case of supersensitization, the photosensitivity is particularly high. If the reducing agent is not deactivated, the printout silver after development tends to be large, and the present invention is particularly effective. In the case of infrared sensitization, the infrared sensitizing dye further has a redox potential capable of reducing silver halide and organic silver salt to some extent, so that the infrared sensitizing dye may be used in a dark place. In the presence of a reducing agent that can reduce the organic silver salt, silver clusters that become fogged silver are easily formed. The formed silver clusters also act as catalyst nuclei to induce fogging, so that when stored in a dark place, the storage stability decreases,
Further, when exposed to a light place after development, a phenomenon such as an increase in printout silver occurs. Further, the sensitivity of the infrared sensitive material extends to the heat radiation region outside the range of visible light, so that the present invention is effective in that printout silver due to heat radiation is increased even in a dark place. In particular, in the case of an infrared spectrally sensitized photosensitive material whose sensitivity has been enhanced by a supersensitizer, the effect is large.

These sensitizing dyes may be used alone or in combination, and the combination of sensitizing dyes is often used particularly for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization and substances exhibiting supersensitization are described in RD17643 (December, 1978), page 23, 1V, section J, or JP-B-9-25500, 43.
-4933, JP-A-59-19032 and JP-A-59-1
No. 92242, JP-A-5-341432 and the like.

In the present invention, a heteroaromatic mercapto compound represented by the following formula (M) is preferred as a supersensitizer.

Formula (M) Ar-SM In the formula (M), M represents a hydrogen atom or an alkali metal atom, and Ar represents a heteroaromatic ring having at least one nitrogen, sulfur, oxygen, selenium or tellurium atom. Or a fused 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.

It is to be noted that a disulfide compound which substantially forms the above-mentioned mercapto compound when contained in a dispersion of a silver salt of an organic acid and / or a silver halide grain emulsion may be used. In particular, a disulfide compound represented by the following general formula (Ma) can be mentioned as a preferred example.

Ar in the general formula (Ma) Ar-SS-Ar has the same meaning as in the general formula (M).

The above-mentioned heteroaromatic ring includes, for example, a halogen atom (eg, Cl, Br, I), a hydroxy group, an amino group, a carboxyl group, an alkyl group (eg, 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.

The following are examples of mercapto-substituted heteroaromatic compounds.

M-1 2-Mercaptobenzimidazole M-2 2-Lucaptobenzoxazole M-3 2-Mercaptobenzothiazole M-4 5-Methyl-2-mercaptobenzimidazole M-5 6-Ethoxy-2-mercapto Benzothiazole M-6 2,2'-dithiobis (benzothiazole) M-7 3-mercapto-1,2,4-triazole M-8 4,5-diphenyl-2-imidazolethiol M-9 2-mercaptoimidazole M -10 1-ethyl-2-mercaptobenzimidazole M-11 2-mercaptoquinoline M-128-mercaptopurine M-13 2-mercapto-4 (3H) -quinazolinone M-147-trifluoromethyl-4-quinoline Thiol M-15 2,3,5,6-tetrachloro-4 Pyridinethiol M-16 4-Amino-6-hydroxy-2-mercaptopyrimidine monohydrate M-17 2-amino-5-mercapto-1,3,4
Thiadiazole M-18 3-Amino-5-mercapto-1,2,4-
Triazole M-19 4-Hydroxy-2-mercaptopyrimidine M-20 2-Mercaptopyrimidine M-21 4,6-Diamino-mercaptopyrimidine M-22 2-Mercapto-4-methylpyrimidine hydrochloride M-23 3-Mercapto- 5-phenyl-1,2,4
-Triazole M-24 2-Mercapto-4-phenyloxazole Further, as the supersensitizer, the following thiuronium compounds can be suitably used.

[0075]

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[0076]

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

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 an even more preferred one is
It is a 21-membered ring.

As typical compounds, the following compounds are synthesized from crown ethers by Pederson in 1967, and many of them have been synthesized 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), edited by Oda, Shono, and Tabushi, "Chemistry of Crown Ethers"
78), Tabushi, "Host-Guest" Kyoritsu Publishing (197)
9), Sasaki, Koga “Synthetic Organic Chemistry” Vol 45
(6), 571-582 (1987).

In the present invention, the organic silver salt is a reducible silver source, and is a silver salt of an organic acid or a heteroorganic acid, especially a long-chain (10 to 30 carbon atoms, preferably 15 to 2 carbon atoms).
5) Silver salts of aliphatic carboxylic acids and nitrogen-containing heterocyclic compounds are preferred. Organic or inorganic complexes in which the ligand has a value of 4.0 to 10.0 as the total stability constant for silver ions are also preferred. Examples of these suitable silver salts include Res.
ear Disclosure Nos. 17029 and 29996, and include the following.

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

The organic silver salt can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver. The organic silver salt is described in Japanese Patent Application Laid-Open No. Hei 9-127463, which describes a forward mixing method, a reverse mixing method, and a simultaneous mixing method. Controlled double jet method or the like is preferably used. For example, an organic acid alkali metal salt (eg, sodium hydroxide, potassium hydroxide, etc.) is added to an organic acid to produce an organic acid alkali metal salt soap (eg, sodium behenate, sodium arachidate, etc.), and then controlled by a control double jet. The above-mentioned soap and silver nitrate are added to produce organic silver salt crystals. At that time, silver halide grains may be mixed.

In the present invention, the organic silver salt has an average particle size of 2
It is preferably not more than μm and 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 from 0.05 to 1.5 μm, in particular from 0.05 to 1.
0 μm is preferred. The monodispersion has the same meaning as that of silver halide, and preferably has a monodispersity of 1 to 30.

Further, in the present invention, the tabular grains of the organic silver salt grains preferably account for at least 60% of the total organic silver salt. In the present invention, the tabular grains mean those having an aspect ratio (abbreviated as “AR”) of 3 or more, which is a ratio between the particle diameter and the thickness, which is represented by the following formula.

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

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

As the reducing agent used in the photothermographic material 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. More specifically, for example, US Pat.
No. 533, No. 3,679,426, No. 3,67
No. 2,904, No. 3,751,252, No. 3,7
No. 82,949, No. 3,801,321, No. 3,
794,488, 3,893,863, 3,887,376, 3,770,448, 3,819,382, 3,773,512,
No. 3,839,048, No. 3,887,378
No. 4,009,039, No. 4,021,24
0, British Patent No. 1,486,148 or Belgian Patent No. 786,086, and JP-A-50-3
No. 6143, No. 50-36110, No. 50-1160
No. 23, No. 50-99719, No. 50-140113
Nos. 51-51933, 51-23721, 52-84727 and JP-B-51-35851, and the present invention relates to such a known reducing agent. Can be appropriately selected and used. As the selection method, the simplest method is to actually prepare a photothermographic material and evaluate the photographic performance of the photothermographic material to determine the superiority of the reducing agent used.

Among the above reducing agents, when a silver aliphatic carboxylate is used as the organic silver salt, preferred reducing agents 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-3,5-di-t-butylphenyl) methane, (2-hydroxy-3-t-butyl-5-methylphenyl)-(2-hydroxy-5-methylphenyl) Methane, 6,6'-benzylidene-bis (2,4-di-t-butylphenol), 6,6'-benzylidene-bis (2-t-butyl-4-methylphenol), 6,6'-benzylidene- Bis (2,4-dimethylphenol), 1,1-bis (2-hydroxy-
3,5-dimethylphenyl) -2-methylpropane,
1,1,5,5-tetrakis (2-hydroxy-3,5
-Dimethylphenyl) -2,4-ethylpentane, 2,
2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5
U.S. Pat. Nos. 3,589,903 and 4,021,249 or British Patent 1,486,148 and JP-A-51-51933. No. 50-36110, No. 50
Polyphenol compounds described in JP-A-116023, JP-A-52-84727 or JP-B-51-35727, bisnaphthols described in U.S. Pat. No. 3,672,904, for example, 2,2'- Dihydroxy-1,1'-binaphthyl, 6,6'-dibromo-
2,2'-dihydroxy-1,1'-binaphthyl, 6,
6'-dinitro-2,2'-dihydroxy-1,1'-
Binaphthyl, bis (2-hydroxy-1-naphthyl) methane, 4,4'-dimethoxy-1,1'-dihydroxy-2,2'-binaphthyl and the like, and further US Pat. No. 3,80
Sulfonamidophenols or sulfonamidonaphthols as described in US Pat. No. 1,321, for example, 4-benzenesulfonamidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4
-Benzenesulfonamidophenol, 4-benzenesulfonamidonaphthol and the like.

The amount of the reducing agent used in the photothermographic material of the present invention varies depending on the kind of the organic silver salt, the reducing agent, and other additives. 05 mol to 10 mol, preferably 0.1 mol to 3 mol
Molar is appropriate. Further, within this range, two or more of the above-mentioned reducing agents may be used in combination.

In the photothermographic material of the present invention, it is desirable to use an additive called a color tone agent, a color tone imparting agent or an activator toner (hereinafter referred to as a color tone agent) together with the above-mentioned components. The color tone agent participates in the oxidation-reduction reaction between the organic silver salt and the reducing agent, and has a function of making the resulting silver image dark, particularly black. Examples of suitable toning agents for use in the present invention are Research Disclosure No. 170
No. 29, which includes the following.

Imides (eg, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (eg, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and , 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 (for example,
N- (dimethylaminomethyl) phthalimide); blocked pyrazoles, isothiuronium (isoth
uronium) derivatives and certain photobleaches (eg, N, N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8-
A combination of (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole; a merocyanine dye (e.g., 3-ethyl-5-((3-ethyl -2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2,4
Oxazolidinedione); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example, 4-
(1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3
-Dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); phthalazine + phthalate Acid combinations; phthalazine (including phthalazine adducts) and maleic anhydride,
And phthalic acid, 2,3-naphthalenedicarboxylic acid or o
At least one selected from phenylene acid derivatives and anhydrides thereof (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride);
Quinazolinediones, benzoxazines, naloxazine derivatives; benzoxazine-2,4-diones (eg, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric triazines (E.g., 2,4-dihydroxypyrimidine),
And tetraazapentalene derivatives (for example, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3
a, 5,6a-Tetraazapentalene). Preferred toning agents are phthalazone or phthalazine.

Binders suitable for the photosensitive layer of the photothermographic material of the present invention are transparent or translucent and generally colorless, and include natural polymers, synthetic polymers and copolymers, and other film-forming media such as gelatin and Arabic. Rubber, polyvinyl alcohol, hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinyl pyrrolidone, casein, starch, polyacrylic acid, polymethyl methacrylate, polymethacrylic acid, polyvinyl chloride, copoly (styrene-maleic anhydride), copoly ( Styrene-acrylonitrile), copoly (styrene-butadiene), polyvinyl acetals such as polyvinyl formal, polyvinyl butyral, polyesters, polyurethanes, phenoxy resin, polyvinyl chloride Emissions, polyepoxides, polycarbonates, polyvinyl acetates, cellulose esters, there is a polyamide or the like, or a non-hydrophilic or hydrophobic. However, among these binders, particularly preferred are water-insoluble polymers such as cellulose acetate, cellulose acetate butyrate and polyvinyl butyral, and among them, polyvinyl butyral is particularly preferred.

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

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

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

The material of the matting agent used in the present invention may be either an organic substance or an inorganic substance. For example, inorganic substances include silica described in Swiss Patent No. 330,158, glass powder described in French Patent No. 1,296,995, etc., and alkali described in British Patent No. 1,173,181 and the like. An earth metal or a carbonate such as cadmium or zinc can be used as a matting agent. As organic matter,
Starch described in U.S. Pat. No. 2,322,037, Belgian Patent 625,451 and British Patent 981,19
No. 8 and the like, and starch derivatives described in JP-B-44-3643.
No. 33, Swiss Patent No. 33
No. 0,158, polystyrene or polymethacrylate; U.S. Pat. No. 3,079,257; polyacrylonitrile; U.S. Pat. No. 3,022,16.
An organic matting agent such as polycarbonate described in No. 9 or the like can be used.

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

The matting agent used in the present invention preferably has an average particle size of 0.5 to 10 μm, more preferably 1.0 to 8.0 μm. The variation coefficient of the particle size distribution is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less. The variation coefficient of the grain size distribution has the same meaning as in the silver halide grains.

In the photothermographic material of the present invention, the matting agent can be contained in any of the constituent layers, but is preferably a constituent layer other than the photosensitive layer, and more preferably the outermost layer as viewed from the support. It is. The method of adding the matting agent may be a method of dispersing in a coating solution in advance and applying,
A method of spraying a matting agent after the application liquid is applied and before the drying is completed may be used. When a plurality of types of matting agents are added, both methods may be used in combination.

The photothermographic material of the present invention has at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. In order to control the amount or wavelength distribution of light transmitted through the photosensitive layer, a filter layer may be formed on the same side as or opposite to the photosensitive layer, or a dye or pigment may be contained in the photosensitive layer. As the dye, compounds described in JP-A-8-201959 are preferred. The photosensitive layer may be composed of a plurality of layers, or a high-sensitivity layer and a low-sensitivity layer may be provided for adjusting the gradation, and these layers may be combined. Various additives may be added to any of the photosensitive layer, the non-photosensitive layer and other layers. The photothermographic material of the present invention may contain, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, and a coating aid.

For exposure of the photothermographic material of the present invention, an argon ion laser (488 nm), a He—Ne laser (633 nm), and a red semiconductor laser (670 nm) are used.
m), infrared semiconductor laser (780 nm, 820 nm)
And the like are preferably used, but an infrared semiconductor laser is more preferably used from the viewpoint that the laser power is high and the photosensitive material can be made transparent.

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

Here, "not substantially vertical" means that the angle which is closest to vertical during laser scanning is preferably 55 degrees or more and 88 degrees or less, more preferably 60 degrees or less.
Degrees to 86 degrees, more preferably 65 degrees to 84 degrees, and most preferably 70 degrees to 82 degrees.

When the laser beam is scanned on the photosensitive material, the beam spot diameter on the exposed surface of the photosensitive material is preferably 200 μm or less, more preferably 100 μm or less. It is preferable that the spot diameter is small in that the shift angle of the laser incident angle from the perpendicular can be reduced. Note that the lower limit of the beam spot diameter is 10 μm. By performing such laser scanning exposure, it is possible to reduce image quality deterioration related to reflected light such as occurrence of interference fringe-like unevenness.

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

For the vertical multiplication, a method such as multiplexing, utilizing return light, or superimposing a high frequency is preferable.
In addition, the vertical multi means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm or more.
nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

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

[0108]

The present invention will be described below with reference to examples.
The present invention is not limited by these examples.

Example 1 [Backing layer] Thickness 1 colored blue with a concentration of 0.170 (measured with a densitometer PDA-65 manufactured by Konica Corporation)
A corona discharge treatment of 8 w / m ² · min is applied to both sides of a 75 μm polyethylene terephthalate (PET) film,
The backing layer coating solution prepared as described below was applied to one surface thereof by an extrusion coater so as to have a dry film thickness of 3.5 μm, and dried using a dry air having a drying temperature of 100 ° C. and a dew point temperature of 10 ° C. After drying for a minute, a backing layer was applied.

(Preparation of Backing Layer Coating Solution) Cellulose acetate butyrate (Eastman Chemical Co., C
AB381-20) 84.2 g, polyester resin (B
4.5 g of Ostic, VitelPE2200B) was added and dissolved. 3.5 g of infrared dye 1 was added to the dissolved solution.
And a fluorine-based surfactant (Surflon KH40, Asahi Glass Co., Ltd.) dissolved in 43.2 g of methanol.
5 g and 2.3 g of a fluorine-based surfactant (Dai Nippon Ink, Megafac F120K) were added, and the mixture was sufficiently stirred until dissolved. Finally, silica (WR Grace, Syloid 64 × 600) dispersed in methyl ethyl ketone at a concentration of 1% by mass with a dissolver-type homogenizer.
0) was added and stirred to prepare a coating solution for the backing layer.

[Photosensitive Layer] (Photosensitive Layer) Preparation of Photosensitive Silver Halide Emulsion 1 A1 Phenylcarbamoyl gelatin 88.3 g Compound (A) (10% methanol solution) 10 ml Potassium bromide 0.32 g Finish up to 5429 ml with water B1 0.67N silver nitrate aqueous solution 2635 ml C1 potassium bromide 51.55 g potassium iodide 1.47 g Make up to 660 ml with water D1 potassium bromide 154.9 g potassium iodide 4.41 g iridium chloride (1% solution) 0.93 ml E10. 4N aqueous potassium bromide solution The following silver potential control amount F1 56% acetic acid aqueous solution 16.0 ml G1 1.72 g of anhydrous sodium carbonate Finished to 151 ml with water Compound (A): HO (CH ₂ CH ₂ O) _n- [CH (CH _{3 ) CH 2 O] 17 - (} CH 2 CH 2 O) m H m + n = 5~7 Tokuoyake No. 58-58288, 1/4 volume and solution (C1) 45 ° C. The entire amount of the solution (B1) To a solution (A1) with a mixing and stirring machine described in Nos. 58-58289, pAg8.0
While controlling the mixture to 9, the mixture was added by the simultaneous mixing method in 4 minutes and 45 seconds to form nuclei. After a lapse of 7 minutes, the solution (B
The remainder of 1) and the total amount of solution (D1) were prepared at a temperature of 45 ° C. and p
While controlling to Ag 8.09, the mixture was added over 14 minutes and 15 seconds by a double jet method. During mixing, the pH of the reaction solution was 5.
It was 6.

After stirring for 5 minutes, the temperature was lowered to 40 ° C., the whole amount of the solution (F1) was added, and the silver halide emulsion was precipitated. The supernatant was removed, leaving 2000 ml of sedimentation,
After adding 10 L of water and stirring, the silver halide was precipitated again. The supernatant was removed, leaving 1500 ml of the sedimented portion, and 10 L of water was further added. After stirring, the silver halide was sedimented. After removing the supernatant liquid leaving 1500 ml of the sedimented portion, the solution (G1) was added, the temperature was raised to 60 ° C., and the mixture was further stirred for 120 minutes. Finally, the pH was adjusted to 5.8, and water was added so as to be 1161 g per mole of silver, whereby photosensitive silver halide emulsion 1 was prepared. This emulsion was cubic silver iodobromide grains having an average grain size of 0.058 μm, a grain size variation coefficient of 12%, and a [100] face ratio of 92%.

(Preparation of powdered organic silver salt) In 4720 ml of pure water, 111.4 g of behenic acid, 83.8 g of arachidic acid,
54.9 g of stearic acid were dissolved at 80 ° C. Next, while stirring at a high speed, a 1.5 M aqueous sodium hydroxide solution 54 was added.
After adding 0.2 ml of concentrated nitric acid and 6.9 ml of concentrated nitric acid,
It cooled to ° C and obtained the organic acid sodium solution.

The temperature of the above-mentioned organic acid sodium salt solution was 55
While maintaining the temperature at 0 ° C, KBr was added to the photosensitive silver halide emulsion 1 and 450 ml of pure water, followed by stirring for 5 minutes.

Next, 760.6 ml of a 1M silver nitrate solution was added over 2 minutes, the mixture was further stirred for 20 minutes, and the water-soluble salts were removed by filtration. After that, the conductivity of the filtrate is 20μ.
Water washing with deionized water and filtration were repeated until the S / cm was reached, centrifugal dehydration was performed, and then hot air drying was performed at 37 ° C. until there was no loss in mass to obtain a powdered organic silver salt.

(Preparation of Preliminary Dispersion) Polyvinyl butyral powder (Butvar B-7, manufactured by Monsanto)
9) 14.57 g was dissolved in 1457 g of methyl ethyl ketone, and a dissolver DIS manufactured by VMA-GETZMANN was used.
While stirring with a PERMAT CA-40M type, 500 g of the obtained powdered organic silver salt was gradually added and thoroughly mixed to prepare a preliminary dispersion.

(Preparation of Photosensitive Emulsion Dispersion) Using a GM-2 type pressure homogenizer (manufactured by SMT Corporation), each preliminary dispersion was dispersed in two passes to prepare a photosensitive emulsion dispersion. In this case, the processing pressure in one pass is 27.
46MPa, the processing pressure during 2 passes is 54.92MP
a.

Next, the following additives required for preparing the photosensitive layer coating solution were prepared.

(Stabilizer liquid) Stabilizer 1 (described below) 1.00 g Potassium acetate 0.31 g Methanol 10 g (Infrared sensitizing dye liquid) Infrared sensitizing dye 1 (described below) 41.0 mg 2-chloro-benzoic acid 2.0 g Compound A (described below) 21.0 g MEK 100 g (additive solution A) 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 51.0 g 4-methylphthalate Acid 3.40 g Infrared dye 1 (described below) 0.22 g MEK 170 g (Preparation of coating solution for photosensitive layer) 100 g of the above-mentioned photosensitive emulsion dispersion
And 45 g of MEK were kept at 25 ° C. while stirring, and a solution of the following antifoggant 1 (10% by mass methanol solution)
0.65 g was added, and the mixture was stirred for 1 hour. Further, 0.84 g of a calcium bromide solution (10% by mass methanol solution) was added, followed by stirring for 20 minutes. Subsequently, after adding 0.70 g of a stabilizer solution and stirring for 10 minutes, 7.90 g of an infrared sensitizing dye solution was added and stirred for 1 hour. Further, 1.50 g of a 1% by mass methanol solution of the following supersensitizer 1 was added and stirred for 30 minutes, and then the temperature was lowered to 13 ° C. and further stirred for 30 minutes. While keeping the temperature at 13 ° C., polyvinyl butyral (Butvar B-79, Monsanto) 26
15 minutes after the addition of g, add 13 g of tetrachlorophthalic acid.
2.3 g of a% by weight MEK solution were added. While continuing stirring, 22 of the following isocyanate compound IC-10
4.5 g of a mass% MEK solution, 27.0 g of an additive solution A,
6.0 g of a 6.5% by mass MEK solution of the exemplified compound 1a-1 of the halogen compound, and 7% by mass of MEK of phthalazine
9.0 g of the solution was sequentially added and stirred to obtain a photosensitive layer coating solution.

[Surface Protective Layer Coating Solution] (Preparation of Matting Agent Dispersion) Cellulose Acetate Butyrate (Eastman Chemical Company, 7.5 g)
CAB17-15) was dissolved in 42.5 g of MEK, and calcium carbonate (Specialty Mi) was added thereto.
generals, Super-Pflex200) 5g
Was added, and 8000 rpm was obtained with a dissolver-type homogenizer.
m for 30 minutes to prepare a matting agent dispersion.

(Preparation of coating solution for surface protective layer) MEK865
g of cellulose acetate butyrate (Eastman Chemical, CAB171-
15): 96 g, polymethylmethacrylic acid (Rohm & Haas Co., Paraloid A-21): 4.5 g, the following vinyl sulfone compound: 1.5 g, benzotriazole: 1.
0 g, F-based activator (Asahi Glass Co., Surflon KH40):
1.0 g was added and dissolved. Next, the matting agent dispersion 30
g was added and stirred to prepare a coating solution for the surface protective layer.

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[Preparation of Photothermographic Material] Each of the above-mentioned coating solutions for the photosensitive layer and the coating solution for the surface protective layer were extruded and simultaneously subjected to multilayer coating using a coater. For the coating, the photosensitive layer was coated in an amount of 1.
9 g / m ² , and the surface protective layer was formed to have a dry film thickness of 2.5 μm. Thereafter, drying was performed for 10 minutes using a drying air having a drying temperature of 75 ° C. and a dew point temperature of 10 ° C. to produce a photothermographic material.

[Exposure and Development Processing] From the emulsion side of the photothermographic material prepared as described above, an exposing machine using a semiconductor laser having a vertical multimode of 800 to 820 nm in wavelength as a light emitting source by high frequency superposition was used. Exposure by laser scanning was provided. At this time, an image was formed with the angle between the exposure surface of the photosensitive material and the exposure laser beam being 75 degrees.

Thereafter, heat development was performed at 115 ° C. for 15 seconds using an automatic developing machine having a heat drum so that the protective layer of the photothermographic material was brought into contact with the drum surface.

[Evaluation of Sensitivity and Fog] The transmission density of the obtained image was measured, and the sensitivity (relative logE sensitivity giving a density higher than that of the unexposed portion by 1.0) and the fog density were evaluated. The photothermographic material after coating and drying was allowed to stand at 50 ° C. and a relative humidity of 75% for 5 days, and then exposed and developed in the same manner to measure sensitivity and fog. In Table 1, the fog and sensitivity fluctuations during storage indicate the changes due to storage (values of the difference before and after storage).

[Evaluation of Fog at 117 ° C. Development] Fog was measured when the developing temperature was 117 ° C. and the developing time was 15 seconds, and the difference from the result of the above-mentioned thermal development at 115 ° C. for 15 seconds was shown. .

[Evaluation of fog and color tone by printout] The photosensitive material after exposure and development was exposed on a light source table (fluorescent light) having an illuminance of 10,000 lux, and the density change was measured for up to 20 hours. Further, the color tone of silver was evaluated for the portion having a transmission density of 1.1 ± 0.05 based on the following criteria. Furthermore, P
After O, the storage fog variation was measured.

Evaluation criteria 5: Pure black tone and no yellowness felt 4: Not pure black but almost no yellowness 3: Partially slightly yellowish 2: Slightly yellowish over the entire surface 1: A yellow color is felt at first glance. Further, the sample exposed for 20 hours is exposed to 55 ° C. and 75% relative humidity.
%, And the fog density after standing for 7 days was measured.

Examples 2 to 19 and Comparative Examples 1 to 4 The same experiment as in Example 1 was conducted except that the halogen compound and the isocyanate compound in Example 1 were changed as shown in Table 1 below. However, the amount of the isocyanate compound added was the same as the -NCO group equivalent. The results are shown in Example 1.
The results are shown in Tables 1 and 2 below. In the table, “relative mol ratio” refers to the relative amount of the halogen compound of Example 1.
Example 2 Addition ratio (molar ratio) of the following halogen compounds
Is shown.

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[Table 1]

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[Table 2]

AF-1, AF-2 and IC-11 in Table 1
The chemical structural formulas of IC-13 are shown below.

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[0136]

According to the present invention, fog generation and sensitivity fluctuation during storage are suppressed with high sensitivity and less occurrence of fog.
Thermal development in which fog density, its fluctuation and color tone deterioration due to printout are suppressed, image stability after printout is good, and fog increases when conditions such as raising the development temperature are strengthened. A photographic light-sensitive material is provided.

Claims (6)

[Claims] 1. A support comprising at least a) an organic silver salt,
A photothermographic material comprising a photosensitive layer containing b) a photosensitive silver halide, c) a reducing agent, and d) a halogen compound represented by the following general formula (1a). Embedded image In the formula, X ₁ , X ₂ and X ₃ each represent a hydrogen atom or an arbitrary substituent. However, at least one of X ₁ , X ₂ and X ₃ is a halogen atom. L ₁ represents a sulfonyl group;
Represents 0 or 1. Y ₁ represents —N (R ₁ ) —, a sulfur atom, an oxygen atom, a selenium atom or — (R ₂ ) C ＝ C (R ₃ ) —, wherein R ₁ , R ₂ and R ₃ are each a hydrogen atom or any Represents a substituent. R represents a hydrogen atom, a halogen atom or a substituted or unsubstituted aliphatic group. R ₁ and R, R ₃ and R may form an alicyclic group with each other. 2. A method according to claim 1, wherein at least a) an organic silver salt is
A photothermographic material comprising a photosensitive layer containing b) a photosensitive silver halide, c) a reducing agent, and d) a halogen compound represented by the following general formula (1b). Embedded image In the formula, X ₁ , X ₂ and X ₃ each represent a hydrogen atom or an arbitrary substituent. However, at least one of X ₁ , X ₂ and X ₃ is a halogen atom. L ₂ represents a carbonyl group or a sulfinyl group; Y ₂ represents a single bond, —N (R1) —, a sulfur atom, an oxygen atom, a selenium atom, or — (R ₂ ) CＣC
(R ₃ ) —. R ₁ , R ₂ and R ₃ each represent a hydrogen atom or an arbitrary substituent. R represents a hydrogen atom, a halogen atom or a substituted or unsubstituted aliphatic group. R ₁ and R, R ₃ and R may form an alicyclic group with each other. 3. A method according to claim 1, wherein at least a) an organic silver salt is
A photothermographic material comprising a photosensitive layer containing b) a photosensitive silver halide, c) a reducing agent, and d) a halogen compound represented by the following general formula (1c). Embedded image In the formula, X ₁ , X ₂ and X ₃ each represent a hydrogen atom or an arbitrary substituent. However, at least one of X ₁ , X ₂ and X ₃ is a halogen atom. L ₃ represents a sulfonyl group, a carbonyl group or a sulfinyl group, and n2 represents 2 or 3. Y ₂ represents a single bond, —N (R ₁ ) —, a sulfur atom, an oxygen atom, a selenium atom, or — (R ₂ ) C ＝ C (R ₃ ) —.
R ₁ , R ₂ and R ₃ each represent a hydrogen atom or an arbitrary substituent. R represents a hydrogen atom, a halogen atom or a substituted or unsubstituted aliphatic group. R ₁ and R, R ₃ and R may form an alicyclic group with each other. 4. The photothermographic material according to claim 1, further comprising an isocyanate compound. 5. The photothermographic material according to claim 4, wherein the isocyanate compound is a polyisocyanate compound. 6. An image forming method, comprising subjecting the photothermographic material according to claim 1 to laser exposure and heat development.