JP2003015255A - Heat developable photosensitive material and image recording method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material having high relative sensitivity and low fog and free of a fog density change (printout density change) and color tone deterioration in exposure to indoor light or viewing screen light after development and to provide an image recording method using the photosensitive material. SOLUTION: The heat developable photosensitive material has a photosensitive layer containing an organic silver salt, a photosensitive silver halide, a reducer and a new halogen compound on a support.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a photothermographic material and an image recording method using the photosensitive material.

[0002]

2. Description of the Related Art In recent years, in the fields of printing and plate making and medical treatment, a waste liquid caused by wet processing of image forming materials has become a problem in terms of workability. Weight loss is strongly desired. Therefore, there is a need for a technology relating to a photothermographic material capable of efficiently exposing a laser image setter to form a clear black image with high resolution. Examples of this type of technology include, for example, U.S. Pat. No. 3,152,904.
No. 3,457,075, (D. Morgan (Mo
rgan) "Dry Silver Photographic Material (Dry
Silver Photographic Mater
ial) ") or D.I. H. Kloster (Klos
Terboer, “Thermal Processed Si System (Thermal Processed Si)
Lever Systems ”(Imaging Processes & Materials (Imaging P
processes and Materials) N
eblette 8th edition, Sturge,
V. Wallworth, A.S. Shepp, pp. 279, 1989), in which an organic silver salt, a catalytically active amount of a photocatalyst (eg silver halide), and a reducing agent are dispersed in a normal (organic) binder matrix. In addition, it produces silver through a redox reaction between a reducible silver source (which functions as an oxidant) and a reducing agent when heated to a high temperature (for example, 80 ° C. or higher) after exposure. The oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by exposure, so that an image is formed corresponding to the exposure.

However, the above-mentioned heat-developable material has a drawback that undesired formation of silver occurs in 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 so far, for example, US Pat. No. 3,874,946.
Issue No. 4,459,350, No. 5,340,71
No. 2, No. 4,756,999, No. 5,594,1
43, No. 5,594,143, JP-A-58-59.
No. 439, No. 59-46641, No. 59-57233.
No., etc.

Further, 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 a means for improving the fog stability during storage.

However, the above-mentioned technique is not sufficiently effective in preventing fog, and those having a high antifoggant effect have a problem that sensitivity is likely to decrease, and further, after development, they are exposed to room light or Shakasten light. Occurrence of fogging density variation (also referred to as printout density variation) and stability of color tone due to printout were still insufficient.

Particularly, when exposed to light at a high temperature of 40 ° C. or higher, the density of the unexposed area is greatly increased and the color tone of the image area is deteriorated by the conventionally known antifoggant. Specifically, the surface temperature of a display device such as a Schaukasten that has been lit for a long time rises to 40 ° C. or higher, and the light-sensitive material exposed on these surfaces causes the fog increase and the color tone due to printout as described above. Deterioration phenomena such as deterioration are likely to occur, and there is a problem that the visibility of the photosensitive material is likely to be significantly reduced.
Improvement was requested.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high relative sensitivity, a low fog, and a fog density fluctuation (printout density fluctuation) even after exposure to room light or Shakasten light after development. (Also referred to as a) and a photothermographic material free from deterioration of color tone, and an image recording method using the photosensitive material.

[0008]

The above objects of the present invention have been achieved by the following items 1 to 4.

1. A photothermographic material comprising a support and a photosensitive layer containing an organic silver salt, a photosensitive silver halide, a reducing agent, and the halogen compound represented by the general formula (1).

2. 2. The photothermographic material as described in 1 above, wherein the photosensitive layer contains an isocyanate compound.

3. 3. The photothermographic material as described in 2 above, wherein the isocyanate compound is a polyisocyanate compound.

4. 4. An image recording method, which comprises subjecting the photothermographic material according to any one of 1 to 3 above to laser exposure and then heat development.

The present invention will be described in detail below. As a result of various studies by the present inventors on the problems of the conventionally known photothermographic materials described above, the organic silver salt, the photosensitive silver halide, the reducing agent, and the above-mentioned general formula (1) on the support. By using a photothermographic material having a photosensitive layer containing a halogen compound represented by, relative sensitivity is high, low fog, and after development, when exposed to room light or Sharksten light, fog It was possible to obtain a photothermographic material free from density fluctuation (also referred to as printout density fluctuation) and color tone deterioration.

The halogen compound represented by the general formula (1) according to the present invention will be described below.

In the general formula (1), examples of the aromatic carbocyclic ring used for the aromatic carbocyclic group represented by A include a benzene ring and a naphthalene ring. The benzene ring and the naphthalene ring may have a substituent.

In the general formula (1), the aromatic heterocyclic ring used for the aromatic heterocyclic group represented by A is a furan ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring or oxadiene ring. Azole ring, triazole ring, triazine ring, thiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, s-
Triazine ring, benzofuran ring, indole ring, benzothiophene ring, benzimidazole ring, benzothiazole ring, purine ring, quinoline ring, isoquinoline ring, indazole ring, purine ring, phthalazine ring, quinoxaline ring,
Examples thereof include a quinazoline ring, a cinnoline ring, a pteridine ring, a phenanthroline ring, an acridine ring, a phenazine ring, a tetrazole ring, a benzoxazole ring, an indolenine ring, and a tetrazaindene ring.

Further, among the aromatic carbocyclic group and the aromatic heterocyclic group, a benzene ring, a pyrrole ring, a pyrimidine ring, a benzothiazole ring, a benzoxazole ring, an indole ring, a furan ring, a thiophene ring, and a benzimidazole ring. Rings and the like are preferably used.

In the general formula (1), the alkyl group represented by Y may be branched or linear, for example, a methyl group,
Ethyl group, propyl group, butyl group, pentyl group, iso
-Pentyl group, 2-ethylhexyl group, octyl group, decyl group and the like.

Examples of the alkenyl group represented by Y in the general formula (1) include 2-propenyl group, 3-butenyl group, 1-methyl-3-propenyl group, 3-pentenyl group and 1-methyl- Examples include 3-butenyl group and 4-hexenyl group.

Examples of the aryl group represented by the general formula (1) include phenyl group, m-chlorophenyl group and p-
Examples thereof include a tolyl group and a naphthyl group.

In the general formula (1), examples of the acyl group represented by Y include an acetyl group and a benzoyl group.

In the general formula (1), the alkoxycarbonyl group represented by Y is, for example, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, phenoxycarbonyl group,
Isopropoxycarbonyl group, isobutoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group, allyloxycarbonyl group, isopentyloxycarbonyl group, benzyloxycarbonyl group, naphthyloxy Examples thereof include a carbonyl group and a pyridyloxycarbonyl group.

In the general formula (1), examples of the carbamoyl group represented by Y include a carbamoyl group, an N-methylcarbamoyl group and an N, N-tetramethylenecarbamoyl group.

Examples of the aromatic heterocyclic group represented by Y in the general formula (1) include pyridyl group, pyrrolyl group, indolyl group, imidazolyl group, furyl group, thienyl group, thiazolyl group, pyrimidinyl group, benzothiazolyl group. Group, a benzoxazolyl group and the like.

The above-mentioned group represented by Y is further a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), an alkoxy group (eg, methoxy group, ethoxy group, etc.), an aryloxy group (eg, , Phenoxy group, p-
Tolyloxy group etc.), cyano group, sulfamoyl group (eg sulfamoyl group, N, N-3-oxapentamethyleneaminosulfonyl group etc.), haloalkyl group (eg 2,2,2-trifluoroethyl group, 2,2) , 3,
3, -tetrafluoropropyl group etc.), alkylsulfonyl group (eg methanesulfonyl group etc., ethanesulfonyl group etc.), acylamino group (eg acetylamino group, benzoylamino group etc.), sulfonamide group (eg methanesulfone) Amide group, butanesulfonamide group, etc.), sulfo group, carboxyl group, phosphono group, sulfate group, hydroxy group, sulfino group, sulfonylaminocarbonyl group (for example, methanesulfonylaminocarbonyl group, ethanesulfonylaminocarbonyl group, etc.), acyl Aminosulfonyl group (eg, acetamidosulfonyl group, methoxyacetamidosulfonyl group, etc.), Acylaminocarbonyl group (eg, acetamidocarbonyl group, methoxyacetamidocarbonyl group, etc.), sulfinylami Carbonyl group (e.g., methanesulfinyl aminocarbonyl group, ethanesulfinyl aminocarbonyl group) may be substituted with a substituent such as.

Specific examples of the compound represented by formula (1) are shown below, but the invention is not limited thereto.

[0027]

[Chemical 1]

[0028]

[Chemical 2]

[0029]

[Chemical 3]

The compound represented by the general formula (1) according to the present invention is 10 ^{-5 to} 1 mol, preferably 1 to 1 mol of the total amount of silver atoms contained in silver halide and organic silver.
It is preferable to add 0 ^-4 to 10 ^-2 mol in the photosensitive layer.

The method of synthesizing the compound represented by the general formula (1) according to the present invention is described in, for example, US Pat. No. 3,892.
It can be synthesized with reference to the description of No. 743 and the like.

Here, a synthetic example of the compound represented by the general formula (1) is shown. Synthesis Example 1 << Synthesis of Compound 1-1 >> Step 1: Synthesis of 2-chloromethylbenzothiazole 3.0 g of 2-aminobenzenethiol was added to 15 parts of ethanol.
After dissolving in ml, 7.0 g of ethyl chloroorthoacetate was added and the mixture was heated under reflux for 4 hours. The obtained reaction solution was concentrated under reduced pressure and recrystallized from hexane to obtain 3.7 g of 2-chloromethylbenzothiazole. 85% yield
Met.

Step 2: Synthesis of 2- (phenylsulfonylmethyl) benzothiazole After dissolving 2.7 g of 2-chloromethylbenzothiazole in 17 ml of acetonitrile, 3.5 g of sodium phenate as benzene is added, and the mixture is heated under reflux for 13 hours. went.
After cooling the obtained reaction liquid, 30 ml of ethyl acetate was added,
Filtration and concentration under reduced pressure were performed. The obtained solid was recrystallized from acetonitrile to obtain 3.3 g of the target compound.
The yield was 80%.

Step 3: Synthesis of compound 1-1 2.2 g of 2- (phenylsulfonylmethyl) benzothiazole was dissolved in 30 ml of dichloromethane and then N-
Bromosuccinimide (4.0 g) was added, and the mixture was stirred at room temperature for 21 hours. Then, 40 ml of ethyl acetate and 40 ml of water were added, the organic layer was separated, and then washed with 50 ml of water. The obtained organic layer was dried over magnesium sulfate, filtered, and then concentrated under reduced pressure, and the obtained solid w was recrystallized from acetonitrile,
Compound 1-1 was obtained. The yield was 70%.

Synthesis Example 2 << Synthesis of Compound 1-28 >> 1.0 g of ethyl phenylsulfonylacetate, 5.6 g of sodium acetate and 25 ml of acetic acid were sequentially mixed, and 1.8 ml of bromine was added dropwise at room temperature. After completion of dropping, the mixture was heated to reflux for 4 hours, allowed to cool, 50 ml of water was added, and 50 ml of ethyl acetate was added.
Was extracted with. The obtained organic layer was washed with a saturated aqueous sodium hydrogen carbonate solution and then dried over magnesium sulfate,
After filtration, it was concentrated under reduced pressure.

Compound 1-28 was obtained by recrystallizing the obtained liquid with hexane. The yield was 75%.

Synthesis Example 3 << Synthesis of Compound 1-31 >> Step 1: Synthesis of N-methyl-N-phenylchloroacetamide N-methylaniline 5.0 g, toluene 30
ml and triethylamine 7.0 g were sequentially mixed, and chloroacetyl chloride 5.8 g and toluene 20 were added under ice-water cooling.
The solution dissolved in ml was added dropwise.

After the completion of dropping, the temperature was returned to room temperature and the mixture was stirred for 5 hours. 100 ml of water and 100 ml of strategy ethyl were added, the organic layer was extracted, and washed successively with 1 mol / liter hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution and saturated saline.

The obtained organic layer was dried over magnesium sulfate, filtered, and concentrated under reduced pressure to recrystallize the obtained solid to obtain N-methyl-N-phenylchloroacetamide. The yield was 70%.

Step 2: 2-Benzenesulfonyl-N
Synthesis of -methyl-N-phenylacetamide N-methyl-N-phenylchloroacetamide 2.2
g, 16 ml of acetonitrile, and 2.6 g of sodium phosphinate containing benzene were sequentially mixed, and heated under reflux for 4 hours. After cooling, 32 ml of ethyl acetate was added, filtered and concentrated under reduced pressure, and the obtained solid was recrystallized from ethanol to give 2
2.8 g of -benzenesulfonyl-N-methyl-N-phenylacetamide were obtained. The yield was 82%.

Step 3: Synthesis of Compound 1-31 The bromination reaction of 2-benzenesulfonyl-N-methyl-N-phenylacetamide was carried out in the same manner as in Synthesis Example 2,
The target compound 1-31 was obtained. The yield was 75%.

From the viewpoint of obtaining the effects described in the present invention, the photothermographic material of the present invention preferably contains an isocyanate compound in combination with the halogen compound represented by the general formula (1). . 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,
It is preferably 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, alkylene group, alkenylene group, 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 is preferably 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 alkoxyl group. Group.

The isocyanate compound is preferably an isocyanate compound having at least two isocyanate groups (including an adduct thereof).
Specifically, aliphatic diisocyanates, aliphatic diisocyanates having a cyclic group, benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates,
Examples thereof include triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates, and adducts of these isocyanates with divalent or trivalent polyalcohols. Particularly preferred are aliphatic polyisocyanates, particularly aliphatic polyisocyanates having a cyclic group.

Examples of the isocyanate compound preferably used in the present invention include the following compounds.

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-dimethylcyclohexanediisocyanate, ω, ω-diisocyanate-1,4-diethylbenzene, 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,
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
A dimer or trimer adduct of these isocyanates (eg hexamethylene diisocyanate 2)
Mol adduct, hexamethylene diisocyanate 3 mol adduct, 2,4-tolylene diisocyanate 2 mol adduct, 2,4-tolylene diisocyanate 3 mol adduct, etc.); two different types selected from these isocyanates Adducts of the above isocyanates; and adducts of these isocyanates with dihydric or trihydric polyalcohols (preferably polyalcohols having up to 20 carbon atoms, such as ethylene glycol, propylene glycol, pinacol, trimethylolpropane, etc.) (For example, an adduct of tolylene diisocyanate and trimethylol propane; an adduct of hexamethylene diisocyanate and trimethylol propane, etc.) and the like. Among these, hexamethylene diisocyanate trimer (1,3,5-triisocyanatohexyl isocyanuric acid) is most preferable.

In the present invention, the isocyanate compound may be contained in the support of the photothermographic material and on any part of the support on the side of the photosensitive layer. For example, a support (in particular, 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, a subbing layer, etc. It can be added to any layer on the side, and can be added to one layer or two or more layers among these layers.

The amount of the isocyanate compound added is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the total mass of the photosensitive layer.

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

IC-1 Desmodu
r) N100, Movey company, aliphatic isocyanate IC-2 Desmodu N3300, Mobay company, aliphatic isocyanate IC-3 Mondur TD-80, Mobay company, aromatic isocyanate IC-4 Mondeu M, Mobay company, aromatic Isocyanate IC-5 Mondue MRS, Movey, Polymer Isocyanate IC-6 Desmodu W, Mobay, Aliphatic Isocyanate IC-7 Papi 27, Dow, Polymer Isocyanate IC-8 Isocyanate T1890, Huls
Els), aliphatic isocyanate IC-9 octadecyl isocyanate, Aldrich Company, aliphatic isocyanate The photosensitive silver halide contained in the photosensitive layer of the 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 in order to suppress white turbidity after image formation and to obtain good image quality.
The average particle size is preferably 0.1 μm or less, more preferably 0.01 to 0.1 μm, and especially 0.0
2 to 0.08 μm is preferable. The particle size as used herein refers to the diameter of a circle (equivalent circle diameter) having the same area as each particle image observed with an electron microscope. The photosensitive silver halide is preferably monodisperse. The monodisperse as used herein means that the variation coefficient of the particle size distribution obtained by the following formula is 40% or less. The coefficient of variation is more preferably 30% or less, and particularly preferably 20% or less.

Coefficient of variation of grain distribution = {(standard deviation of grain size) / (average value of grain size) × 100 The shape of the photosensitive silver halide grain is not particularly limited, but 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 Miller index (100) plane is (11) in the adsorption of sensitizing dye.
T. 1 utilizing the adsorption dependence of the (1) plane and the (100) plane. T
ani, J .; Imaging Sci. , 29,165
(1985).

Another preferred silver halide shape is tabular grain. The tabular grain here means the square root of the projected area with a grain size of rμm and a vertical thickness of hμm.
And 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, more preferably 0.01 to 0.08 μm. Such tabular grains are described in U.S. Pat. Nos. 5,264,337, 5,314,798, 5,320,958, etc., and the desired tabular grains can be easily obtained. You can

The halogen composition of the photosensitive silver halide is not particularly limited, and any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide can be used. Good. The photosensitive silver halide emulsion used in the present invention is described in P. Gla
Chimieet Physique by fkides
Photographique (Paul Monte
1 company, 1967), G.I. F. Duffin Ph
otographic Emulsion Chemi
story (published by The Focal Press, 196
6 years), V. L. Ma by Zelikman et al
king and Coating Photogra
phic 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 as a formation for reacting a soluble silver salt and a soluble halogen salt, any one of a one-sided mixing method, a simultaneous mixing method, a combination thereof and the like may be used. Good.

The photosensitive silver halide used in the present invention preferably contains a metal ion 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,
At least one selected from Re, Os, Ir, Pt and Au is preferable.

These metal ions can be introduced into the silver halide in the form of metal complexes or metal complex ions. As the metal complex or metal complex ion, a hexacoordinated metal complex represented by the following general formula is preferable.

General formula [ML ₆ ] ^{m In the} above general formula, M is a transition metal selected from the elements of groups 6 to 11 of the periodic table, L is a ligand, m is 0,-, 2-, 3- or Represents 4-. Specific examples of the ligand represented by L include halides (fluorides, chlorides, bromides and iodides), cyanides, cyanates, thiocyanates, selenocyanates, tellurocyanates, azides and aco. Examples include ligands, nitrosyl, thionitrosyl, and the like, with preference given to ako, nitrosyl, thionitrosyl, and the like. When an aco ligand is present, it preferably occupies one or two of the ligands. L may be the same or different. Particularly preferred specific examples of M include rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os).
Is.

Specific examples of transition metal complex ions are shown below. 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)] 2Cl _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: [R (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 type, or the same type of metal and two or more types of different metals may be used in combination. The content of these metal ions, metal complexes or metal complex ions is generally 1 × 10 ⁻⁹ to 1 × 10 ⁻² mol per mol of silver halide, and preferably 1 × 10 ^{−. It is 8} to 1 × 10 ⁻⁴ mol.

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

When the silver halide is added, it may be divided and added several times, and it may be uniformly contained in the silver halide grains.
-306236, 3-167545, 4-76
No. 534, No. 6-110146, No. 5-273683.
It is also possible to contain the particles having a distribution as described in No. Preferably, it can have a distribution inside the particles.

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

When added to the surface of the particles, a necessary amount of an aqueous solution of the metal compound may be added to the reaction vessel immediately after the particles are formed, during or during physical ripening or at the end of chemical ripening.

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

The photosensitive silver halide grains used in the present invention are preferably chemically sensitized. As a preferable chemical sensitization method, a sulfur sensitization method, a selenium sensitization method, or a tellurium sensitization method can be used as well known in the art. Further, a noble metal sensitizing method such as a gold compound, platinum, palladium or iridium compound, or a reduction sensitizing method can be applied.

Known compounds can be used as the compounds preferably used in the sulfur sensitizing method, the selenium sensitizing method, and the tellurium sensitizing method, and the compounds described in JP-A-7-128768 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, P = Te Compounds having a bond, tellurocarboxylates, Te-organyl tellurocarboxylic acid esters, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond, and 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, or US Pat. No. 2,448,060 and British Patent 618. , 061 etc. can be preferably used.

Specific examples of the compound used in the reduction sensitization method include 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 carried out by ripening while maintaining the pH of the emulsion at 7 or higher or pAg at 8.3 or lower. Further, reduction sensitization can be performed by introducing a single addition portion of silver ions during grain formation.

In the photosensitive layer of the photothermographic material of the present invention, for example, JP-A-63-159841 and JP-A-60-14033 are used.
5, No. 63-231437, No. 63-259651
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,
The sensitizing dyes described in No. 175 and No. 4,835,096 can be used. Useful sensitizing dyes used in the present invention are, for example, Research Disclosure I.
tem 17643 IV-A (December 1978 p.
23) or the literature cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, for an argon ion laser light source, Japanese Patent Application Laid-Open No. 60-1
62247, JP-A-2-48635, US Pat. No. 2,161,331, West German Patent No. 936,071,
The simple merocyanines and helium neon laser light sources described in Japanese Patent Application No. 3-189532 and the like are disclosed in JP-A Nos. 50-62425, 54-18726, and 59-.
No. 102229, trinuclear cyanine dyes, merocyanines described in Japanese Patent Application No. 6-103272, LE
Japanese Patent Publication Sho 48 for D light source and infrared semiconductor laser light source
-42172, 51-9609, 55-398.
18, JP-A-62-284343, JP-A-2-10.
JP-A-59-191032 for thiacarbocyanines and infrared semiconductor laser light sources described in JP-A-5135.
And the tricarbocyanines described in JP-A-60-80841, JP-A-59-192242 and JP-A-3-
Dicarbocyanines containing a 4-quinoline nucleus described in General Formulas (IIIa) and (IIIb) of No. 67242 are advantageously selected. Furthermore, the wavelength of the infrared laser light source is 750n
m or more, more preferably 800 nm or more, in order to deal with a laser having such a wavelength range, JP-A-4-18
No. 2639, No. 5-341432, and Japanese Patent Publication No. 6-523
87, No. 3-10931, US Pat. No. 5,441,
The sensitizing dyes described in JP-A No. 866, JP-A No. 7-13295 and the like are preferably used. These sensitizing dyes may be used alone, and a combination of sensitizing dyes is often used particularly for the purpose of supersensitization. With sensitizing dye,
The emulsion itself may contain a dye that does not itself have a spectral sensitizing action or a substance that does not substantially absorb visible light and exhibits supersensitization.

Since the photosensitivity is particularly high when supersensitized, the printout silver after development tends to be large unless the reducing agent is deactivated, and the present invention is particularly effective. Further, when infrared sensitized, the infrared sensitizing dye further has a redox potential capable of reducing silver halide or an organic silver salt to some extent. In the presence of a reducing agent capable of reducing the organic silver salt of, the silver clusters that become fog silver are likely to be formed. The generated silver clusters also act as catalyst nuclei to induce fogging, which reduces the storage stability when stored in a dark place,
Further, when it is placed in a bright place after development, a phenomenon such as an increase in printout silver occurs. Further, since the infrared sensitive material has sensitivity up to the heat radiation region outside the visible light range, the present invention is effective against the fact that the printout silver due to the heat radiation increases even in a dark place. In particular, the effect is great in the case of infrared spectrally sensitized light-sensitive materials in which the sensitivity is increased by a supersensitizer.

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

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

General formula (M) Ar-SM In the formula, M represents a hydrogen atom or an alkali metal atom, and A
r represents an aromatic heterocycle having at least one nitrogen, sulfur, oxygen, selenium or tellurium atom.

Examples of the aromatic heterocycle include benzimidazole, naphthimidazole, benzothiazole,
Naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzoterrazole, imidazole, oxazole, pyrazole, triazole, triazine, pyrimidine, pyridazine, pyrazine,
Pyridine, purine, quinoline, quinazoline, etc. are mentioned.

When contained in a dispersion of an organic acid silver salt and / or a silver halide grain emulsion, a disulfide compound represented by the following general formula (Ma) is preferable.

General formula (Ma) Ar-SS-Ar In the formula, Ar has the same meaning as in the case of the general formula (M).

The aromatic heterocycle used in the above general formulas (M) and (Ma) is, for example, a halogen atom (for example, C
1, Br, I), a hydroxyl group, an amino group, a carboxyl group, an alkyl group (for example, one or more carbon atoms, preferably one having 1 to 4 carbon atoms) and an alkoxyl group (for example, one). It may have a substituent selected from the group consisting of the above carbon atoms, preferably those having 1 to 4 carbon atoms.

Examples of the mercapto-substituted heteroaromatic compound are shown below. M-1: 2-mercaptobenzimidazole M-2: 2-mercaptobenzoxazole M-3: 2-mercaptobenzothiazole M-4: 5-methyl-2-mercaptobenzimidazole M-5: 6-ethoxy- 2-Mercaptobenzothiazole 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-12: 8-mercaptopurine M-13: 2-mercapto-4 (3H) -quinazolinone M -14: 7-Trifluoromethyl-4-quinolinethiol M-15: 2,3,5,6-tetrachloro Ro-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, the compounds shown below can be preferably used as the supersensitizer.

[0077]

[Chemical 4]

[0078]

[Chemical 5]

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

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

A typical compound is crown ether, which was synthesized by Pederson as described below in 1967, and many compounds have been synthesized since its unique report.
These compounds are C.I. J. Pederson, Jou
rnal of American chemical
society vol, 86 (2495), 701
7-7036 (1967), G.I. W. Gokel, S .;
H, Korzeniowski, “Macrocycl”
ic polyethr synthesis ”, Sp
Ringer-Vergal, (1982), edited by Oda, Shono, and Tabushi, "Chemistry of Crown Ether", Kagaku Dojin (19)
78), "Host-Guest", Kyoritsu Publishing, edited by Tabushi (197)
9), Sasaki, Koga "Synthetic Organic Chemistry" Vol 45
(6), 571-582 (1987) and the like.

The organic silver salt according to the present invention is a reducible silver source, and is a silver salt of an organic acid or a heteroorganic acid, particularly a long-chained one (having 10 to 30 carbon atoms, preferably 15 to 25 carbon atoms).
Silver salts of aliphatic carboxylic acids and nitrogen-containing heterocyclic compounds are preferred. Also preferred are organic or inorganic complexes in which the ligand has a total stability constant for silver ions of 4.0 to 10.0. Examples of these suitable silver salts include Res
search Disclosure Nos. 17029 and 29963, and include:

Silver salts of organic acids such as gallic acid, oxalic acid,
Silver salts such as behenic acid, stearic acid, arachidic acid, palmitic acid and lauric acid. Silver carboxyalkyl thiourea salts, for example, silver salts such as 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, aldehydes and hydroxy-substituted aromatic carboxylic acids Silver salts or complexes of polymer reaction products, for example, aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.), hydroxy-substituted acids (eg salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid) ) A silver salt or complex of a reaction product, a silver salt or a complex of thiones, for example, 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazolin-2-thione, and 3-carboxymethyl-4. -Silver salts or complexes such as thiazoline-2-thione, imidazole, pyrazole, urazole, 1 2,
4-thiazole and 1H-tetrazole, 3-amino-
Complexes or salts of nitrogen acid and silver selected from 5-benzylthio-1,2,4-triazole and benzotriazole, silver salts such as saccharin and 5-chlorosalicylaldoxime, and silver salts of mercaptides. Among these, preferred silver salts are silver behenate, silver arachidate and 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, and it is described in the forward mixing method, the reverse mixing method, the simultaneous mixing method and JP-A-9-127643. The controlled double jet method or the like is preferably used. For example, by adding an alkali metal salt (eg, sodium hydroxide, potassium hydroxide, etc.) to an organic acid to make an organic acid alkali metal salt soap (eg, sodium behenate, sodium arachidate), and then using a control double jet. Then, the soap and silver nitrate are added to prepare a crystal of an organic silver salt. 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 μm or less and monodisperse. With the average particle size of the organic silver salt, particles of the organic silver salt are, for example, spherical,
In the case of rod-like or tabular grains, it means the diameter when considering a sphere equivalent to the volume of organic silver salt grains. The average particle size is preferably 0.05 to 1.5 μm, particularly 0.05 to 1.
0 μm is preferable. The monodisperse has the same meaning as in the case of silver halide, and the monodispersity is preferably 1 to 30.

In the present invention, the tabular grains of the organic silver salt grains preferably account for 60% or more of all the organic silver salts. In the present invention, the tabular grains preferably have a ratio of grain size to thickness, that is, an aspect ratio (abbreviated as “AR”) represented by the following formula of 3 or more.

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

In the present invention, in order to prevent devitrification of the light-sensitive material, the total amount of silver halide and organic silver salt is preferably 0.5 g or more and 2.2 g or less per 1 m ² in terms of silver amount. . Within this range, a high contrast image can be obtained. Further, the amount of silver halide with respect to the total amount of silver is 50% or less, preferably 25% or less, and more preferably 0.1% to 15% by mass ratio.

As the reducing agent used in the photothermographic material of the present invention, those known in the art can be used. Examples thereof include phenols, polyphenols having two or more phenol groups, and naphthol. , Bisnaphthols, polyhydroxybenzenes having two or more hydroxyl groups, polyhydroxynaphthalenes having two or more hydroxyl groups, ascorbic acids, 3-pyrazolidones, pyrazolin-5-ones, pyrazolines, phenylenediamine , Hydroxylamines, hydroquinone monoethers, hydrooxamic acids, hydrazides, amidoximes, 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
82,949, 3,801,321, 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
No. 0, British Patent No. 1,486,148 or Belgian Patent No. 786,086, and Japanese Patent Laid-Open No. 50-3.
6143, 50-36110, 50-1160
No. 23, No. 50-99719, No. 50-140113.
No. 51-51933, No. 51-23721, No. 52-84727, or JP-B No. 51-35851, there are reducing agents specifically exemplified, and the present invention includes such known reducing agents. It can be used by appropriately selecting from the above. The simplest selection method is to actually make a photothermographic material and evaluate its photographic performance to check the superiority or inferiority of the reducing agent used.

Of the above reducing agents, when an aliphatic carboxylic acid silver salt is used as the organic silver salt, preferred reducing agents include polyphenols in which two or more phenol groups are linked by an alkylene group or sulfur, particularly An alkyl group (eg, methyl group, ethyl group, propyl group, t-butyl group, cyclohexyl group, etc.) or acyl group (eg, acetyl group, propionyl group, etc.) is present in at least one position adjacent to the hydroxy-substituted position of the phenol group. Polyphenols in which two or more of the substituted phenol groups are linked by an alkylene group or sulfur, such as 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, 4,021,249 or British Patent 1,486,148, such as -di-t-butylphenyl) propane, and JP-A-51-51933. , Ibid. 50-36110, ibid. 50
No. 116023, No. 52-84727 or Japanese Patent Publication No. 51-35727, bisnaphthols described in US 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 US Pat. No. 3,80.
Sulfonamide phenols or sulfonamide naphthols as described in 1,321, eg 4-benzenesulfonamidephenol, 2-benzenesulfonamidephenol, 2,6-dichloro-.
4-benzenesulfonamide phenol, 4-benzenesulfonamide naphthol and the like can be mentioned.

The amount of the reducing agent used in the photothermographic material of the present invention varies depending on the type of the organic silver salt, the reducing agent and other additives, but generally it is 0. 05 mol to 10 mol, preferably 0.1 mol to 3
Molar is suitable. Further, within the range of this amount, two or more kinds of the above-mentioned reducing agents may be used in combination.

In the heat-developable light-sensitive material of the present invention, it is desirable to use an additive (hereinafter, referred to as a color tone agent) called a color tone agent, a color tone imparting agent or an activator toner, together with the above-mentioned respective components. The toning agent has a function of participating in the redox reaction between the organic silver salt and the reducing agent to make the resulting silver image a dark color, especially black. Examples of suitable toning agents 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 2). , 4-thiazolidinedione); naphthalimides (for example, N-hydroxy-1,8-naphthalimide); cobalt complex (for example, hexaminetrifluoroacetate of cobalt), mercaptans (for example, 3
-Mercapto-1,2,4-triazole); N- (aminomethyl) aryldicarboximides (e.g.,
N- (dimethylaminomethyl) phthalimide); blocked pyrazoles, isothiuronium (isoth
iuronium) derivative and certain photobleaching agents (eg, N, N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8-
(Combination of (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole); merocyanine dye (for example, 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 + phthal A combination of acids; phthalazine (including an adduct of phthalazine) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivative and its anhydride (for example,
Phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) in combination with at least one compound; quinazolinediones, benzoxazine, naltoxazine derivatives; benzoxazine-2,4-dione (Eg, 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, 4
H-2,3a, 5,6a-tetraazapentalene). A preferred color tone agent is 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. Gum arabic, polyvinyl alcohol, hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethylmethacrylate, 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. Isopropylidene, polyepoxides,
There are polycarbonates, polyvinyl acetates, cellulose esters, polyamides and the like, which may be hydrophilic or non-hydrophilic. However, among these binders, water-insoluble polymers such as cellulose acetate, cellulose acetate butyrate and polyvinyl butyral are particularly preferable, and polyvinyl butyral is particularly preferable among them.

In the present invention, the binder amount in the photosensitive layer is preferably 1.5 to 6 g / m ² . More preferably, it is 1.7 to 5 g / m ² .

In the present invention, a matting agent is preferably contained on the photosensitive layer side, and a matting agent is preferably provided on the surface of the light-sensitive material in order to prevent scratching of the image after heat development. The content of the agent is preferably 0.5 to 30% with respect to the total binder on the photosensitive layer side.

When a non-photosensitive layer is provided on the side opposite to the photosensitive layer with a support sandwiched between them, it is preferable that at least one layer on the non-photosensitive layer side contains a matting agent, and the slipperiness of the photosensitive material is improved. It is preferable to dispose a matting agent on the surface of the light-sensitive material also for preventing fingerprints and fingerprints, and the matting agent is 0.5 to 40% by mass with respect to the total binder of the layer on the side opposite to the photosensitive layer side. It is preferable to contain.

The material of the matting agent used in the present invention may be either an organic substance or an inorganic substance. For example, as the inorganic substance, silica described in Swiss Patent No. 330,158, glass powder described in French Patent No. 1,296,995, and alkali described in British Patent No. 1,173,181, etc. An earth metal or a carbonate such as cadmium or zinc can be used as a matting agent. Examples of the organic matter include starch described in US Pat. No. 2,322,037,
Belgian Patent No. 625,451 and British Patent No. 981,
Starch derivatives described in JP-B No. 198, etc., JP-B-44-36
Polyvinyl alcohol described in No. 43, polystyrene or polymethacrylate described in Swiss Patent No. 330,158, polyacrylonitrile described in US Pat. No. 3,079,257, and US Pat. No. 3,022.
Organic matting agents such as polycarbonate described in No. 169 can be used.

The shape of the matting agent may be either a fixed shape or an amorphous shape, but it is preferably a fixed shape, and a spherical shape is preferably used. The size of the matting agent is represented by the diameter when the volume of the matting agent is converted into a spherical shape. In the present invention, the particle size of the matting agent refers to the spherically converted diameter.

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 coefficient of variation of the particle size distribution is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less. The coefficient of variation of the grain size distribution has the same meaning as in the silver halide grain.

In the photothermographic material of the present invention, the matting agent may be contained in any constituent layer, but is preferably a constituent layer other than the photosensitive layer, and more preferably the outermost layer as viewed from the support. It is a layer. The matting agent may be added by dispersing it in the coating solution in advance and applying it, or by spraying the matting agent after applying the coating solution and before drying is completed. When adding a plurality of types of matting agents, 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. A filter layer may be formed on the same side as or on the opposite side of the photosensitive layer in order to control the amount or wavelength distribution of light transmitted through the photosensitive layer, or the photosensitive layer may contain a dye or a pigment. Good. As the dye, the 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 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), a red semiconductor laser (670 nm), an infrared semiconductor laser (780 nm, 820 nm) and the like are preferably used. However, 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 exposed surface of the photosensitive material and the scanning laser light is not substantially vertical.

Here, the phrase "substantially vertical" does not mean that the angle is the most vertical during laser scanning, preferably 55 degrees or more and 88 degrees or less, more preferably 60 degrees or more and 86 degrees or less, and further It is preferably 65 degrees or more and 84 degrees or less, and most preferably 70 degrees or more and 82 degrees or less.

The beam spot diameter on the exposed surface of the photosensitive material when the laser light is scanned on the photosensitive material is preferably 200 μm or less, more preferably 100 μm or less. It is preferable that the spot diameter is smaller because the angle of deviation of the laser incident angle from the vertical can be reduced. In addition,
The lower limit of the beam spot diameter is 10 μm. By performing such laser scanning exposure, it is possible to reduce image quality deterioration due to reflected light, such as occurrence of interference fringe-like unevenness.

Further, from the viewpoint of reducing deterioration of image quality such as occurrence of interference fringe-like unevenness as compared with the vertical single mode scanning laser light, the exposure used in the image recording method of the present invention is a vertical multi-scan laser. It is preferable to use a laser scanning exposure machine that emits light.

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

The photothermographic material of the present invention is stable at room temperature, but it is developed by heating to high temperature after exposure. The heating temperature is preferably 80 ° C. or higher and 200 ° C. or lower, and more preferably 100 ° C. or higher and 150 ° C. or lower.

By heating within the temperature range described above, a silver image is produced by a redox reaction between an organic silver salt (which functions as an oxidizing agent) and a reducing agent. This reaction process proceeds without supplying a treatment liquid such as water from the outside.

[0111]

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

Example 1 << Preparation of Backing Layer >> Concentration 0.170 (Konica Corporation)
175 μm thick polyethylene terephthalate (PE, which is colored blue with a densitometer PDA-65 manufactured by PE)
T) Both sides of the film were subjected to a corona discharge treatment of 8 W / m ² · min, and the backing layer coating solution prepared as follows was extruded on one side with a coater to a dry film thickness of 3.5 μm. The coating was applied and dried for 5 minutes using a drying air having a drying temperature of 100 ° C. and a dew point temperature of 10 ° C. to form a backing layer.

(Preparation of coating solution for backing layer) Cellulose acetate butyrate (Eastman Chemical Co., C
AB381-20) 84.2 g, polyester resin (B
4.5 g of Vistel PE2200B (Ostic) was added and dissolved. In the dissolved liquid, 3.5g of infrared dye 1
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 fluorinated surfactant (Dainippon Ink and Co., Ltd., Megafac F120K) were added and sufficiently stirred until they were dissolved. Finally, silica dispersed in methyl ethyl ketone at a concentration of 1% by a dissolver type homogenizer (WR Grace, Syloid 64 × 600).
0) of 75 g was added and stirred to prepare a backing layer coating liquid.

<< Preparation of Photosensitive Layer >> (Preparation of Photosensitive Silver Halide Emulsion 1) Solution (A1) Phenylcarbamoyl gelatin 88.3 g Compound (B) (10% methanol solution) 10 ml Potassium bromide 0.32 g Water Solution (B1) 0.67N silver nitrate aqueous solution 2635ml Solution (C1) Potassium bromide 51.55g Potassium iodide 1.47g Solution 660ml with water (D1) Potassium bromide 154.9g Potassium iodide 4.41g Iridium chloride (1% solution) 0.93 ml solution (E1) 0.4 mol / liter potassium bromide aqueous solution The following silver potential control amount solution (F1) 56% acetic acid aqueous solution 16.0 ml solution (G1) anhydrous sodium carbonate 1. compounds finish 151ml with 72g water _{(B): 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 B No. 58-58288, by using a mixing and stirring machine described in Nos. 58-58289 solution (A1 ), The 1/4 amount of the solution (B1) and the total amount of the solution (C1) were added at 45 ° C. and pAg of 8.0.
While controlling at 9, the mixture was added for 4 minutes and 45 seconds by the simultaneous mixing method to perform nucleation. After 7 minutes, the solution (B
The rest of 1) and the total amount of the solution (D1) were heated at a temperature of 45 ° C., p
While controlling to Ag 8.09, it was added over 14 minutes and 15 seconds by the double-blending method. During the 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. Remove the supernatant, 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, 10 L of water was further added, and after stirring, the silver halide was precipitated. 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 that the amount was 1161 g per mol of silver to prepare a photosensitive silver halide emulsion 1. 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] plane ratio of 92%.

(Preparation of powdered organic silver salt) 111.4 g of behenic acid and 83.8 g of arachidic acid were added to 4720 ml of pure water.
54.9 g of stearic acid were dissolved at 80 ° C. Next, while stirring at high speed, 540.2 ml of a 1.5 mol / liter sodium hydroxide aqueous solution was added, 6.9 ml of concentrated nitric acid was added, and then the mixture was cooled to 55 ° C. to obtain an organic acid sodium salt solution.

The temperature of the above fatty acid sodium solution was adjusted to 55
KBr was added to the above-mentioned photosensitive silver halide emulsion 1 and 450 ml of pure water while the temperature was kept at 0 ° C., and the mixture was stirred for 5 minutes.

Next, a 1 mol / liter silver nitrate solution 76
0.6 ml was added over 2 minutes, stirred for another 20 minutes, and water-soluble salts were removed by filtration. After that, washing with deionized water and filtration were repeated until the conductivity of the filtrate reached 20 μS / cm, centrifugal dehydration was carried out, and then hot air drying was carried out at 37 ° C. until there was no loss of mass, to obtain the powdered organic silver salt. Obtained.

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

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

Next, the following additive liquids necessary for preparing the photosensitive layer coating liquid were prepared. (Preparation of stabilizer solution) Stabilizer 1 1.00 g Potassium acetate 0.31 g Methanol 10 g (Preparation of infrared sensitizing dye solution) Infrared sensitizing dye 1 41.0 mg 2-chloro-benzoic acid 2.0 g Compound A 21.0 g MEK 100 g (Additive liquid A) 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 51.0 g 4-methylphthalic acid 3.40 g Infrared dye 1 0.22 g MEK 170 g (Preparation of photosensitive layer coating solution) The photosensitive emulsion dispersion 100
g and MEK 45 g, while maintaining the temperature at 25 ° C. with stirring,
Antifoggant 1 solution (10% by mass methanol solution)
0.65 g was added and stirred for 1 hour. Further, 0.84 g of a calcium bromide solution (10% by mass methanol solution) was added and stirred for 20 minutes. Subsequently, 0.70 g of the stabilizer solution was added and stirred for 10 minutes, and then 7.90 g of the infrared sensitizing dye solution was added and stirred for 1 hour.

Further, 1.50 g of a 1% by mass methanol solution of the supersensitizer 1 was added and stirred for 30 minutes, then the temperature was raised to 13
The temperature was lowered to ℃ and the mixture was stirred for another 30 minutes. Polyvinyl butyral (Monsanto, Inc.)
Butvar B-79) (26 g) was added and 15 minutes later, a 13% by mass solution of tetrachlorophthalic acid in MEK was added.
3 g was added. While further stirring, the 22% by mass MEK solution of the isocyanate compound IC-10 was added to 4.5%.
g, 27.0 g of the additive liquid A, 6.0 g of a 6.5% by mass MEK solution of the exemplified compound 1-28 of a halogen compound, 9.0 g of a 7% by mass MEK solution of phthalazine, and potassium p-toluenethiosulfonate. Of 0.5% by mass of MEK solution
g was sequentially added and stirred to obtain a photosensitive layer coating liquid.

<< Preparation of Coating Solution for Surface Protective Layer >> MEK865
g of cellulose acetate butyrate (Eastman Chemical Company, CAB171-
15): 96 g, polymethylmethacrylic acid (Rohm & Haas Company, Paraloid A-21): 4.5 g, 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, 30 g of the matting agent dispersion liquid shown below was added and stirred to prepare a surface protective layer coating liquid.

[0124]

[Chemical 6]

[0125]

[Chemical 7]

(Preparation of Matting Agent Dispersion) Cellulose Acetate Butyrate (Eastman Chemical)
Company, 7.5 g of CAB171-15) to MEK42.5
g of calcium carbonate (Specia)
Light Minerals, Super-Pfle
x200) (5 g) was added, and the resulting mixture was dispersed with a dissolver type homogenizer at 8000 rpm for 30 minutes to prepare a matting agent dispersion liquid.

<< Preparation of Photothermographic Materials 1 to 8 >> The coating solutions for the photosensitive layer and the coating solution for the surface protective layer were simultaneously extruded using a coater to perform multilayer coating. The coating was adjusted so that the photosensitive layer had a coated silver amount of 1.9 g / m ² and the surface protective layer had a dry film thickness of 2.5 μm. Then, the photothermographic material 1 was prepared by drying for 10 minutes using a drying air having a drying temperature of 75 ° C. and a dew point temperature of 10 ° C.

Further, the photothermographic materials 2 to 8 were similarly prepared except that the halogen compound was changed as shown in Table 1 below.
Was produced.

Regarding the obtained photothermographic materials 1 to 8,
Exposure and development were performed as described below, and fog, relative sensitivity, density change (after printout), and color tone (after printout) were evaluated according to the methods described below.

(Exposure and Development Processing) From the emulsion surface side of the above photothermographic material, a wavelength of 800 to 820 was obtained by superimposing a high frequency wave.
Exposure by laser scanning was performed by an exposure device using a semiconductor laser having a vertical multimode of nm as a light emitting source. At this time, an image was formed by setting the angle between the exposed surface of the photosensitive material and the exposure laser beam to 75 degrees.

After that, an automatic developing machine having a heat drum was used to carry out heat development treatment at 120 ° C. for 15 seconds so that the protective layer of the photothermographic material was in contact with the surface of the drum.

(Evaluation of Relative Sensitivity and Fog Density) The transmission density of the obtained image was measured to evaluate the relative sensitivity (relative logE sensitivity giving 1.0 higher density than the unexposed portion) and the fog density.

(Change in density after printout (change in fog density), evaluation of color tone) The photosensitive material after exposure and development was
After exposure on a light source table (fluorescent lamp light) with an illuminance of 10,000 lux, the change in fog density after 20 hours was measured. Further, the color tone of silver was rank-evaluated into 5 ranks on the basis of the following standard for the portion having a transmission density of 1.1 ± 0.05. Further, the fogging fluctuation after storage after PO was measured.

Evaluation criteria 5: Pure black tone with no yellowness 4: Not pure black, but almost no yellowness 3: Partially slightly yellowish 2: A slight yellowishness is felt on the entire surface 1: At first glance, you can feel yellowishness The results obtained are shown in Table 1.

[0135]

[Table 1]

It is clear from Table 1 that the sample of the present invention has a high relative sensitivity, low fog and little change in density in printout and a good color tone, as compared with the comparison.

[0137]

According to the present invention, the relative sensitivity is high, the fog is low, and the fog density fluctuation (also referred to as printout density fluctuation) and the deterioration of the color tone after the development is exposed to the room light or the Schaukasten light. It was possible to provide a heat-developable photosensitive material and an image recording method using the photosensitive material.

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Claims (4)

[Claims] 1. A heat having a photosensitive layer containing an organic silver salt, a photosensitive silver halide, a reducing agent, and a halogen compound represented by the following general formula (1) on a support. Development photosensitive material. Formula _{(1) A-SO 2 -C} (X) in ₂ -Y [wherein, X represents a fluorine atom, chlorine atom, bromine atom or iodine atom, Y is an alkyl group, an alkenyl group, an acyl group, It represents an alkoxycarbonyl group, a carbamoyl group, an aromatic carbocyclic group or an aromatic heterocyclic group. A represents an aromatic carbocyclic group or an aromatic heterocyclic group. ] 2. The photothermographic material according to claim 1, wherein the photosensitive layer contains an isocyanate compound. 3. The photothermographic material according to claim 2, wherein the isocyanate compound is a polyisocyanate compound. 4. An image recording method comprising heating and developing the photothermographic material according to claim 1 after laser exposure.