JP2002250983A - Method for producing organic silver salt dispersion, apparatus therefor, heat developable photosensitive material, image recording method and image forming method both using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for uniformly forming an organic silver salt dispersion used for a heat developable photosensitive material, a production apparatus therefor, a heat developable photosensitive material using the organic silver salt dispersion and having improved sensitivity and fog, an image recording method and an image forming method both using the heat developable photosensitive material. SOLUTION: In the method for producing an organic silver salt dispersion by reacting an aqueous solution or suspension of an alkali salt of an organic acid with a water-soluble silver salt in a reaction vessel, at least one agitating member is present in the reaction vessel and photosensitive silver halide is added through a nozzle disposed near the agitating member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for producing an organic silver salt dispersion used for a photothermographic material, a photothermographic material using the organic silver salt dispersion, and an image using the photothermographic material. The present invention relates to a recording method and an image forming method.

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical treatment, waste liquids caused by wet processing of image forming materials have been a problem in terms of workability. There is a strong demand for weight loss. Therefore, there has been a need for a technique relating to photothermographic materials for photographic technology, which enables efficient exposure with a laser imagesetter or laser imager and can form a high-resolution, clear black image.

As a technique for this purpose, a photothermographic material for forming a photographic image using a photothermographic processing method is disclosed in, for example, US Pat. Nos. 3,152,904 and 3,457,075.
No. or D. H. Klosterb (Klosterb)
oer) "Temperature processed silver systems (T
thermally Processed Silver
Systems) "(Imaging Processes and Materials)
sses and Materials) Neble
tte 8th edition, Sturge, V.T. Walworth, A .; Shep (Sh
ep), ed., p. 279, 1989).

Various methods are known for preparing an organic silver salt as a silver supplier used in a photothermographic material.
For example, JP-A-49-93310 and JP-A-49-9461.
Nos. 9 and 53-68702, a method for preparing an organic silver salt in a coexisting solution of water and a poorly water-soluble solvent;
Nos. 186,745, 47-9432 and U.S. Pat. No. 3,700,458 for preparing an organic silver salt in an organic solvent, as disclosed in JP-A-53-31611 and JP-A-53-31611.
And a method of preparing an organic silver salt in an aqueous solution as described in US Pat. Nos. 4,117,54 and 46,709 and US Pat. No. 5,434,043.

On the other hand, in order to impart photosensitivity to the photothermographic material, a method of incorporating photosensitive silver halide into the photothermographic material is widely known. The photosensitive silver halide may be prepared based on a conventional aqueous silver halide gelatin emulsion.
This is advantageous from the viewpoint of easy introduction of techniques such as crystal wall control, impurity doping, and chemical ripening.

However, when preparing an organic silver salt in the presence of or in an organic solvent during the preparation of the organic silver salt, the photosensitive silver halide rendered hydrophilic by gelatin is uniformly dispersed in the organic silver salt. It is very difficult to obtain a desired Dmax and sensitivity in terms of photographic characteristics.

Therefore, a method is generally employed in which photosensitive silver halide is added at the stage of preparing an organic silver salt in an aqueous solution. In this sense, it is more advantageous to prepare the organic silver salt in an aqueous solution. As a method of preparing an organic silver salt dispersion in an aqueous solution, an organic fatty acid is dissolved in water at a temperature equal to or higher than its melting point, and reacted with an alkali hydroxide, and then, when the temperature is lowered, photosensitive silver halide is added. A method is known in which an organic silver salt dispersion is formed by adding a water-soluble silver salt. However, when the temperature is lowered after the addition of alkali hydroxide, the viscosity of the dispersion increases sharply, and when the water-soluble silver salt is added, the viscosity further increases, so that the uniformity of the dispersion is not maintained and the dispersion is formed. The organic silver salt particles become non-uniform, causing a reduction in sensitivity.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and an apparatus for uniformly forming an organic silver salt dispersion used in a photothermographic material, a sensitivity using the organic silver salt dispersion, and a fog reduction. It is an object of the present invention to provide an improved photothermographic material, an image recording method and an image forming method using the photothermographic material.

[0009]

The above object of the present invention is achieved by the following means.

[0010] 1. In a method for producing an organic silver salt dispersion in which an aqueous solution or suspension of an alkali salt of an organic acid, a water-soluble silver salt and photosensitive silver halide are reacted in a reaction vessel, at least one stirring member is provided in the reaction vessel. A method for producing an organic silver salt dispersion, wherein photosensitive silver halide is added through a nozzle provided in the vicinity thereof.

2. Stirring along the inner wall or bottom of the reaction tank and stirring by at least one high-speed rotating high-speed stirring member are simultaneously performed, and photosensitive silver halide is added through a nozzle installed near the high-speed stirring member. 3. The method for producing an organic silver salt dispersion according to the above item 1, wherein

3. 3. The method for producing an organic silver salt dispersion according to the above 1 or 2, wherein the photosensitive silver halide grains are monodispersed.

4. 3. The method for producing an organic silver salt dispersion according to 1 or 2, wherein a water-soluble silver salt is added after the addition of the photosensitive silver halide.

5. In an apparatus for producing an organic silver salt dispersion in which an aqueous solution or suspension of an organic acid alkali salt and a water-soluble silver salt are reacted in a reaction vessel, the apparatus has at least one stirring member in the apparatus, and has a photosensitive member near the stirring member. An apparatus for producing an organic silver salt dispersion, comprising a nozzle for adding neutral silver halide grains.

6. A member for stirring along the inner wall or bottom in the reaction vessel, at least one high-speed rotating high-speed stirring member, and a nozzle for adding photosensitive silver halide particles near the high-speed stirring member are provided. 6. An apparatus for producing an organic silver salt dispersion according to the above item 5, wherein

[7] In a photothermographic material having a protective layer and a photosensitive layer containing an organic silver salt dispersion, a reducing agent and a binder on a support, the organic silver salt dispersion may be any of the above 1, 2,
A photothermographic material formed by the manufacturing method according to 3 or 4.

8. 8. An image recording method, wherein the exposure is performed by an exposure device in which the angle between the exposure surface of the photothermographic material and the scanning laser beam does not become substantially perpendicular.

9. 8. An image forming method, wherein the photothermographic material according to 7 is heat-developed in a state where the solvent is contained in an amount of 5 to 1000 mg / m < ² >.

10. 8. An image forming method, wherein the protective layer of the photothermographic material according to the above item 7 is brought into contact with a heated drum to carry out thermal development.

Hereinafter, the present invention will be described in detail. (Organic silver salt) The production of an organic silver salt is described in the above-mentioned patents and the like. Is difficult and is a manufacturing problem. Therefore, there is a demand for a method capable of uniformly producing an organic silver salt even in a medium having a relatively high viscosity as described above.

The organic silver salt has a great effect on the developability of heat-developable photosensitive material (hereinafter, also simply referred to as photosensitive material) and basic characteristics such as fog. It is preferable that the particles have a fine and uniform particle size. In particular, the organic silver salt dissolves quickly and uniformly as a silver ion source by thermal development, and silver ions must be supplied to the development site. If large particles that take a long time to dissolve are mixed, development proceeds. This is unfavorable in a heat development system, which is a competitive reaction between development and fogging. Once prepared organic silver salts are separately dispersed and pulverized and used after adjusting the particle diameter to a fine particle size.However, even if a high-shearing disperser or mixer is used, the dispersion time becomes longer. However, it is also important to obtain uniform organic silver salt particles during the preparation of the organic silver salt.

In view of the above, the present inventors have conducted intensive studies on a method for preparing an organic silver salt having a uniform particle size and a small number of coarse particles, and particularly a method for preparing a silver salt of a long-chain fatty acid. It has been found that the object of the present invention is achieved by a manufacturing apparatus.

As described above, a method for preparing an organic silver salt dispersion in an aqueous solution generally involves dissolving an organic fatty acid in water at a temperature equal to or higher than its melting point and then reacting with an alkali hydroxide to form an alkali metal organic acid. It is known that a salt is added, a silver halide emulsion is added, and a water-soluble silver salt is further added to form an organic silver salt dispersion.

In these methods, an organic acid component such as an organic acid alkali metal or ammonium salt as an organic silver salt-forming component is uniformly reacted with a component such as photosensitive silver halide or a water-soluble silver salt such as silver nitrate. In order to achieve this, it is necessary to eliminate local unevenness. for that reason,
It is necessary to ensure that the consumption of the two components (or one component in the case of a single jet) occurs quickly and that no local accumulation of unreacted components occurs.

This requires a quick mixing of the reactants, and the added reactants need to be mixed immediately.

Further, for this purpose, it is preferable that the reaction components are added to the liquid, that is, in the vicinity of the stirring member of the mixer, rather than to the liquid surface. The added components are now mixed and reacted immediately. Even with normal stirring,
Usually, a vortex is formed in the liquid and the liquid is stirred. However, it is preferable that the addition port of the reaction component is located at a position near the stirring member so as to be engulfed by the vortex, which means that it is in the vicinity. This effect is particularly large when the viscosity of the reaction medium is high.

Since these vortices are weak in a conventional stirrer, if the present invention is to be carried out more effectively, a stronger vortex such as a high-speed centrifugal radiation stirrer (dissolver mixer) is generated, and the components are reduced. An entrainment type is preferred. In this method, a toothed disk-shaped impeller, which is formed by alternately bending circular saw blades up and down, is rotated at high speed to generate a vortex. The vortex strongly entrains the generated powder and each reaction component, so that the reaction is performed more uniformly and the shearing force is strong, so that the produced powder is also effectively dispersed.

More preferably, a high-speed rotary shearing stirrer is used. This stirrer not only rotates the stirring blade at high speed but also has a stationary ring (stater) so as not to cause excessive cavitation near the outer periphery of the stirring blade. It is a combination. In this case, the strong shearing effect and impact generated between the rotor and the stationary ring can be used, and a strong axial flow is formed along the rotation axis of stirring, so that nucleation of organic silver salt particles is short. Along the axial flow efficiently at time, the reaction proceeds more uniformly. In addition, the axial flow also improves the uniformity in the rotation axis direction, and it is easier to ensure the uniformity even in a medium having a high viscosity.

In any of these stirrers, a reaction component addition port is provided in the vicinity of the stirring blade (ie, at a position where the reaction components are sucked into the vortex).

The shape of the reaction component addition port may be any as long as it does not hinder the above effects, and may be a simple nozzle or a nozzle having a porous tip end.

According to the present invention, for example, in the case of the double jet method, two addition ports are provided for simultaneously adding two components to the vicinity of the stirring blade. In the case of the single jet method in which one component of the reaction is put in the reaction vessel and the other component is mixed, one addition port for supplying the component to be added near the stirring blade is provided. It can be done by something.

The present invention is preferably carried out by combining various stirring blades as described above to enhance the above-mentioned effect. A high-speed rotary stirrer having an addition nozzle in the vicinity is used, and at the same time, a reaction vessel is used. It is preferred to use at least one additional auxiliary stirrer in order to ensure overall homogeneity in the interior. For example, a high-speed rotation centrifugal radiation type stirrer, or more preferably, a reaction component is supplied to the vicinity of a high-speed rotation shear type stirrer by a nozzle and the reaction is performed,
It is preferable to combine an ordinary stirrer, for example, a stirrer having a propeller blade, a turbine blade, or the like, to such an extent that the uniformity of the whole container is sufficiently ensured. The purpose of the stirrer used for this purpose is to ensure the uniformity of the reaction system.
It depends on the shape and size of the reaction vessel. When a large reaction vessel is used as described later, as an auxiliary stirrer for efficiently stirring the entire reaction vessel, in addition to the one having a simple propeller blade, a high-speed rotary centrifugal radiation type stirrer is used in combination. You may.

By supplying photosensitive silver halide, one of the organic silver salt forming components, to the vicinity of a high-speed shearing stirrer, the added photosensitive silver halide is immediately mixed with other components. Thus, a local organic silver salt dispersion is obtained without causing local accumulation of unreacted photosensitive silver halide.

The same effect can be obtained when an organic silver salt dispersion is obtained by supplying a water-soluble silver salt such as silver nitrate to the vicinity of a high-speed shearing stirrer after the addition of the photosensitive silver halide.

Examples of the high-speed rotary shear type stirrer particularly preferably used in the present invention include T.I. K. Combimix (manufactured by Tokushu Kika Kogyo Co., Ltd.), Satake Hybrid Mixer (manufactured by Satake Chemical Machinery Co., Ltd.), Vacuum emulsification stirrer (manufactured by Mizuho Industry Co., Ltd.), Vacuum emulsification and dispersion device Flimix (manufactured by Shinko Pantech Co., Ltd. ) And the like.

As a preferred embodiment of the present invention, an example of an apparatus for producing an organic silver salt dispersion in which a plurality of stirrers are combined will be described. FIG. 1 is a schematic view of an apparatus for producing an organic silver salt dispersion.

In FIG. 1, the reaction tank 1 provided with a jacket pot 6 for heating, cooling and maintaining the reaction temperature during the reaction has a non-uniformity due to the stagnation of the reaction solution particularly near the vessel wall. In order to prevent this, an anchor blade 2 which is normally used at a slower rotation than a stirring blade for the reaction is provided. The stirring blade for performing the reaction of the present invention is represented by a homomixer 5 which is a high-speed shearing stirrer. Since the axial flow along the rotation axis of the homomixer 5 is formed from below the stirring blade to above, the nozzle 4 for adding in the liquid is provided immediately below the stirring blade very close to the homomixer 5. The component supplied from the immediate vicinity of the homomixer 5 through the submerged addition nozzle 4 passes through the homomixer 5 and is uniformly mixed and reacted with another component such as an organic acid alkali metal salt in the reaction tank. In this case, since the efficiency of the stirring in the vertical direction is increased by the generated axial flow, more uniform production becomes possible.

An enlarged view of the homomixer is shown in FIG. It has a structure in which a stirring blade 7 that rotates at high speed by a rotating shaft 9 that rotates at high speed, and a fixed ring 8 (stator) provided on the outer periphery of the stirring blade. Numeral 10 indicates the direction of the axial flow.

Although this manufacturing apparatus is provided with a dissolver mixer 3 of a high-speed rotary centrifugal radiation type stirrer, it is difficult to ensure uniformity in the reaction tank only with the anchor blade. This is because when a large reaction tank is used, local unevenness in the concentration of the reaction components is eliminated. The use of a high-speed centrifugal radial stirrer forms a vortex and improves the uniformity of the reaction system. In the above device, M represents a motor for each stirrer.

The peripheral speed of the anchor wing is 0.1
10 m / sec to 10 m / sec, more preferably 0.1 to 10 m / sec.
1.5 m / sec, particularly preferably 0.1 to 3 m
/ Sec.

The peripheral speed of the stirring member of the dissolver mixer or homomixer is preferably from 1 to 100 m / sec, more preferably from 1 to 15 m / sec.
Particularly preferably, it is 1 to 30 m / sec.

In the present invention, as described above, the organic silver salt is a reducible silver source, and a silver salt of an organic acid and a hetero organic acid containing a reducible silver ion source, especially a long chain (10 to 3)
An aliphatic carboxylic acid having 0, preferably 15 to 25 carbon atoms) and a silver salt of a nitrogen-containing heterocyclic ring are preferred. The ligand is
Organic or inorganic silver salt complexes having a total stability constant for silver ions of 4.0 to 10.0 are also useful. Examples of suitable silver salts are described in Research Disclosure (hereinafter abbreviated as RD) Nos. 17029 and 29963, and silver salts of organic acids (eg, gallic acid, oxalic acid,
Silver salts of behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid and the like); carboxyalkylthiourea salts of silver (for example, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3 Silver complexes of aldehydes with hydroxy-substituted aromatic carboxylic acids (e.g., aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted acids (e.g., salicylic acid, Silver complex of the reaction product with benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid); silver salts or complexes of thioenes (for example,
3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thioene, and silver salts or complexes of 3-carboxymethyl-4-thiazoline-2-thioene); imidazole, pyrazole, urazole, 1,
Complexes or salts of nitrogen acids with silver selected from 2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole and benzotriazole; saccharin, 5-chlorosalicylaldoxime And silver salts of mercaptides. Preferred silver sources are silver behenate, silver arachidate, silver stearate, and silver palmitate.

(Photosensitive Silver Halide) Photosensitive silver halide functions as an optical sensor. In the invention, the average grain size of the photosensitive silver halide is preferably smaller, in order to suppress white turbidity after image formation, and to obtain good image quality, and the average grain size is preferably 0.1 μm or less, more preferably 0.01 to 0.1 μm, especially 0.02 to 0.
08 μm is preferred. Here, the particle size refers to the diameter (equivalent circle diameter) of a circle having the same area as an individual particle image observed with an electron microscope. The photosensitive silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion determined by the following equation is 40 or less. It is more preferably at most 30 and particularly preferably at most 20.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100 The shape of silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane is high. The ratio is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more. The ratio of the Miller index [100] plane is determined by the T.M. Tani, J .; Imaging Sci. , 29,
165 (1985).

Another preferred form of photosensitive silver halide is tabular grains. Here, a tabular grain is
The aspect ratio = r / h when the square root of the projected area is r μm and the vertical thickness is h μm is 3 or more. Among them, the aspect ratio is preferably 3 to 50.
It is. Further, the particle size is preferably 0.1 μm or less, and more preferably 0.01 to 0.08 μm. These production methods are described in U.S. Pat. Nos. 5,264,337, 5,314,798, and 5,320,958, and can easily obtain target tabular grains. it can.

The halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. The photographic emulsion used in the present invention is P.I. Chimie et by Glafkids
Physique Photographique
(Paul Montel, 1967);
F. Photographic Em by Duffin
ulsion Chemistry (The Foca
l Press, 1966); L. Zelik
Making and Coa by man et al
ting Photographic Emulsio
n (published by The Focal Press, 1964)
Can be prepared using the methods described in US Pat. That is, any of an acidic method, a neutral method, an ammonia method and the like may be used, and a method of reacting a soluble silver salt and a soluble halide may be any of a one-sided mixing method, a double-sided mixing method, a combination thereof and the like. Good.

(Metal Ions) The photosensitive silver halide used in the present invention preferably contains metal ions belonging to groups 6 to 11 of the periodic table for improving illuminance failure and adjusting gradation. The above metals include W, Fe, Co, N
i, Cu, Ru, Rh, Pd, Re, Os, Ir, P
t and Au are preferred.

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

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

Particularly preferred examples of M are rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os).

The following are specific examples of transition metal complex ions, but the present invention is not limited to these.

[0052] 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 two or more kinds of the same kind and different kinds of metals may be used in combination. 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 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 preferably added at the stage of nucleation.

At the time of addition, the compound may be added in several portions. It can be uniformly contained in 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. H11-163, etc., the particles can be contained in the particles with a distribution. In the present invention, it is preferable to have a distribution inside the particles.

These metal compounds can be added by dissolving them in water or a suitable organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides). A method in which an aqueous solution of a compound powder or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or the silver salt solution and the halide solution are simultaneously When mixed, 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 required amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or a method in which halogenation is performed. There is a method in which another silver halide grain doped with a metal ion or complex ion in advance during silver preparation 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.

For addition to the particle surface, immediately after the formation of the particles,
During or during physical ripening, or during chemical ripening,
A required amount of an aqueous solution of a metal compound can be charged into the reaction vessel.

In the present invention, the photosensitive silver halide grains may or may not be desalted after grain formation, but desalting is known in the art, such as a noodle method or a flocculation method. It can be desalted by the method.

(Chemical Sensitization) The photosensitive silver halide used in the present invention is preferably chemically sensitized. Preferred chemical sensitization methods include sulfur sensitization, selenium sensitization, and tellurium sensitization well known in the art. In addition, 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 compound preferably used in the sulfur sensitization method, the selenium sensitization method, and the 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,
Diacyltellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, 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 and the like can be preferably used.

Specific compounds used in the reduction sensitization method include, in addition to ascorbic acid and thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid,
Hydrazine derivatives, borane compounds, silane compounds, polyamine compounds and the like can be used. In addition, the emulsion p
Reduction sensitization can be achieved by aging while keeping H at 7 or more or pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing silver ions during grain formation.

(Reducing Agent) Examples of the reducing agent used in the light-sensitive material of the present invention include generally known reducing agents.
For example, phenols, polyphenols having two or more phenol groups, naphthols, bisnaphthols, polyhydroxybenzenes having two or more hydroxyl groups, polyhydroxynaphthalenes having two or more hydroxyl groups, ascorbic acids, 3-pyrazolidones, pyrazolin-5-ones, pyrazolines, phenylenediamines, hydroxylamines, hydroquinone monoethers, hydroxamic acids, hydrazides, amide oximes, N-hydroxyureas, and the like. For details, see, for example, U.S. Patent Nos. 3,615,533, 3,679,426, 3,672,904, 3,751,252, 3,782,949,
Nos. 3,801,321 and 3,794,488
No. 3,893,863, No. 3,887,37
No. 6, No. 3,770,448, No. 3,819,3
No. 82, No. 3,773, 512, No. 3, 839,
No. 048, No. 3,887,378, No. 4,00
No. 9,039, No. 4,021,240, British Patent No. 1,486,148 or Belgian Patent No. 786.
No. 086 and JP-A-50-36143, 5
No. 0-36110, No. 50-116023, No. 50-
No. 99719, No. 50-140113, No. 51-51
No. 933, No. 51-23721, No. 52-84727
Or the reducing agents specifically exemplified in JP-B-51-35851. The present invention can be used by appropriately selecting from such known reducing agents. As the selection method, the simplest method is to actually prepare a photosensitive material and evaluate the photographic performance to determine the superiority of the reducing agent used.

Among the above reducing agents, when an aliphatic silver carboxylate 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; In particular, 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. Is a polyphenol in which two or more of the phenol groups substituted by an alkylene group or sulfur, for example, 1,1-
Bis (2-hydroxy-3,5-dimethylphenyl) methane, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) butane, 1,1-bis (2-hydroxy-
3,5-dimethylphenyl) -2-methylpropane,
1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, 1,1-bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, 1,1-bis (2-hydroxy-3-t
-Butyl-5-methylphenyl) -2-methylpropane, 1,1-bis (2-hydroxy-3-t-butyl-
5-ethylphenyl) methane, 1,1-bis (2-hydroxy-3,5-di-t-butylphenyl) methane, 1
-(2-hydroxy-3-t-butyl-5-methylphenyl) -1- (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), 1,1,5,5-tetrakis (2-hydroxy-
3,5-dimethylphenyl) -2,4-ethylpentane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-
U.S. Pat. Nos. 3,589,903 and 4,021,249 or British Patent No. 1,486,148 such as (3,5-di-t-butylphenyl) propane; Polyphenol compounds described in US Pat. No. 5,672,904 or JP-B-51-35727; and US Pat. No. 3,672,904. Bisnaphthols such as 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 U.S. Pat.
Sulphonamidophenols or sulphonamidonaphthols as described in U.S. Pat.
Examples thereof include 2-benzenesulfonamidophenol, 2,6-dichloro-4-benzenesulfonamidophenol, and 4-benzenesulfonamidonaphthol.

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

(Color Toning Agent) In the photographic material of the present invention, it is desirable to use an additive (hereinafter referred to as a color toning agent) called a color toning agent, a color toning agent or an activator toner 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. Many kinds of compounds are already known as color toning agents, most of which are compounds having an imino group, a mercapto group or a thione group. From these, an appropriate color tone agent may be selected according to the type of the organic silver salt and the reducing agent used. Examples of the toning agent that provides a preferable toning effect in the light-sensitive material of the present invention include phthalazinones (for example, phthalazinone, 2-acetylphthalazinone,
-Carbamoylphthalazinone), 2-pyrazoline-5
-Ones (e.g., 3-methyl-2-pyrazolin-5-one and the like), quinazolines (e.g., quinazoline, 4-methylquinazoline and the like), and pyrimidines (e.g., 6-methyl-
2,4-dihydroxypyrimidine and the like), 1,2,5-triazines (for example, 3-methyl-4,6-dihydroxy-1,2,5-triazine and the like), phthalazinediones (for example, phthalazinedion) And heterocyclic compounds having an imino group such as cyclic imides (for example, succinimides, phthalimides, urazoles, benzoxazinediones, and naphthalimides). Two or more of these color toning agents may be used in combination.
As described in JP-A Nos. 020 and 53-55115, the use of benzoxazinediones, benzothiazinediones or phthalimides in combination with phthalazinone results in storage under high temperature and high humidity. Deterioration of the color tone effect can be prevented.

As described in US Pat. Nos. 3,847,612 and 3,994,732, phthalic acid, naphthoic acid or phthalamic acid is used in combination with imidazoles or phthalazines. It can also be used as a toning agent.

When a toning agent is used, the amount of the toning agent is 0.0001 to 2 mol, preferably 0.000 to 2 mol per mol of the organic silver salt.
A range of 5 to 1 mole is preferred.

(Antifoggant) The light-sensitive material of the present invention may contain an antifoggant. Examples of effective antifoggants include mercury compounds known from U.S. Pat. No. 3,589,903. However, these mercury compounds are environmentally unfavorable, and studies on non-mercury antifoggants have been conducted for a long time. Preferred non-mercury antifoggants include, for example, U.S. Pat.
No. 75, No. 4,452,885 and JP-A-59-5.
And antifoggants as disclosed in US Pat.

Particularly preferred non-mercury antifoggants are described in US Pat. Nos. 3,874,946 and 4,756,9.
No. 99, -C (X ¹ )
(X ² ) (X ³ ) (where X ¹ and X ² are halogen atoms and X
³ is a heterocyclic compound having one or more substituents represented by a hydrogen atom or a halogen atom). Examples of these suitable antifoggants include compounds described in JP-A-9-288328, paragraphs [0030] to [0036].

As another preferred example of the antifoggant, JP-A-9-90550, paragraph [006]
2] to [0063]. Further, other suitable antifoggants are described in U.S. Pat.
No. 028,523 and European Patent Nos. 600,587, 605,981 and 631,176.

(Sensitizing dye) The photographic material of the present invention includes, 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. 4,751,1
No. 75 and 4,835,096 can be used. Useful sensitizing dyes for use in the present invention are described, for example, in the literature described or cited in RD17643 IV-A (p.23, December 1978).

The light-sensitive material of the present invention was exposed by an argon ion laser (488 nm) and a He-Ne laser (63
3 nm), a red semiconductor laser (670 nm), an infrared semiconductor laser (780 nm, 820 nm) and the like are preferably used. However, from the viewpoint of high laser power and transparency of a photosensitive material, an infrared semiconductor laser is used. Lasers are more preferably used. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be selected. For example, Japanese Patent Application Laid-Open No. 60-162247 and Japanese Patent Application Laid-Open
No. 4,861,331, U.S. Pat. No. 2,161,331, West German Patent No. 936,071 and JP-A-5-11389. -62425,
For the trinuclear cyanine dyes described in JP-A-54-18726 and JP-A-59-102229, the merocyanines described in JP-A-7-287338, the LED light source and the infrared semiconductor laser light source, Japanese Patent Publication No. -42172
The thiacarbocyanines and infrared semiconductor laser light sources described in JP-A Nos. 51-9609, 55-39818, JP-A-62-284343 and JP-A-2-105135 are disclosed in Tricarbocyanines described in JP-A-59-19032 and JP-A-60-80841; JP-A-59-192242; JP-A-3-6724.
Dicarbocyanines containing a 4-quinoline nucleus described in No. 2 in the general formulas (IIIa) and (IIIb) are advantageously selected. Further, in order to support a laser light source having a wavelength of 750 nm or more and further 800 nm or more, Japanese Patent Application Laid-Open No.
No. 2639, No. 5-341432, No. 7-13295
And sensitizing dyes described in JP-B-6-52387, JP-B-3-10931 and U.S. Pat. No. 5,441,866 are preferably used.

These sensitizing dyes may be used alone.
They may be used in combination. Combinations of sensitizing dyes are often used, especially 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 addition, a printout inhibitor and various additives for preventing discoloration due to printout of an unexposed portion after the heat development processing, such as a surfactant, an antioxidant, a stabilizer, a plasticizer, and an ultraviolet absorber Agents, coating aids and the like may be used in the light-sensitive material of the present invention. These additives and the other additives mentioned above are described in RD 17029 (June 1978, p.
Compounds described in 9 to 15) can be preferably used. These additives may be added to any of the photothermographic layer, the non-photosensitive layer, and other layers.

(Binder) As the binder used in the light-sensitive material of the present invention, natural and synthetic polymers and copolymers can be used. For example, water-soluble polymers such as gelatin, polyvinyl alcohol and hydroxyethyl cellulose, cellulose acetate, cellulose Acetate butyrate, polyvinylpyrrolidone, polymethyl methacrylate, polyvinyl chloride, copoly (styrene-
There are water-insoluble polymers such as maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), and polyvinyl acetals such as polyvinyl formal, polyvinyl butyral, polyvinyl acetates, and cellulose esters. 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.

Each component used in the light-sensitive material of the present invention is
It is dispersed in at least one colloid as a binder. Examples of suitable binders include the above-mentioned hydrophobic polymer materials, and as described above, polyvinyl butyral is most preferable as the binder used in the photosensitive layer. If necessary, two or more of these polymer materials may be used in combination. The amount of the polymer material used is an amount sufficient to support the component dispersed or dissolved therein, that is, an amount effective as a binder. The range can be appropriately determined by those skilled in the art. For example, when at least the organic silver salt is dispersed and supported, the mass ratio to the organic silver salt is 10 to 1 to 1.
It is in the range of 1 to 10, especially 4 to 1 to 4.

(Support) The composition containing each component of the light-sensitive material of the present invention is usually used while being supported on the binder.
One or two or more layers are applied separately on various supports selected from a wide range of materials. Materials for the support include various polymer materials, glass, wool cloth, cotton cloth,
Paper, metal (for example, aluminum) and the like can be mentioned, but in terms of handling as an information recording material, a material that can be processed into a flexible sheet or roll is preferable. Therefore, as the support in the light-sensitive material of the present invention, a plastic film (for example, a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyamide film, a polyimide film, a cellulose triacetate film, a polycarbonate film, or the like) is preferable. As described above, in the present invention, a biaxially stretched polyethylene terephthalate film is particularly preferred.

(Coating) The method of coating each layer of the light-sensitive material of the present invention is not particularly limited, and a known method such as a bar coater method, a curtain coating method, a dipping method, an air knife method, and a hopper coating method may be used. Can be. A pre-metering type coating method called an extrusion method is more preferable.

(Layer Structure) The light-sensitive material of the present invention is preferably provided with a protective layer and a back coat layer in addition to the above-mentioned photothermographic layer. A layer structure can be formed, or an intermediate layer can be provided therebetween.

As the binder for the protective layer, water-insoluble polymers such as cellulose acetate, cellulose acetate butyrate and polyvinyl butyral are preferable, and cellulose acetate and cellulose acetate butyrate are particularly preferable.

The preferred thickness of the photothermographic layer containing silver halide of the present invention is 0.2 to 40 μm per layer.
More preferably, it is 2 to 30 μm.

The preferable thickness of the protective layer is 0.
It is 2 to 10 μm, more preferably 1 to 5 μm.

The preferable thickness of the back coat layer is 0.2 to 10 μm, more preferably 1 to 5 μm per layer.

(Solvent) In the present invention, it is preferable that a small amount of solvent is contained during thermal development of the photosensitive material. As these solvents, those used as coating solvents for the photothermographic layer and the protective layer may be left in a small amount, or may be contained in a small amount by applying a separate solvent or spraying. This improves the thermal development characteristics and allows higher gamma and lower fog to be achieved.

Examples of these solvents include ketones such as acetone, isophorone, ethyl amyl ketone,
Examples include methyl ethyl ketone and methyl isobutyl ketone. Examples of alcohols include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, diacetone alcohol, cyclohexanol, and benzyl alcohol. Glycols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, hexylene glycol and the like. Examples of ether alcohols include ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and the like. Examples of ethers include ethyl ether, dioxane, and isopropyl ether. Examples of the esters include ethyl acetate, butyl acetate, amyl acetate, and isopropyl acetate. N-pentane, n-hexane, n
-Heptane, cyclohexane, benzene, toluene, xylene and the like. Examples of chlorides include methyl chloride, methylene chloride, chloroform, dichlorobenzene and the like. Examples of the amines include monomethylamine, dimethylamine, triethanolamine, ethylenediamine, and triethylamine. Other examples include water, formamide, dimethylformamide, nitromethane, pyridine, toluidine, tetrahydrofuran, acetic acid and the like. However, the solvent is not limited to these. These solvents can be used alone or in combination of several kinds.

The content of the solvent in the light-sensitive material can be adjusted by changing conditions such as temperature in a drying step after the coating step. Further, the content of the solvent can be measured by gas chromatography.

The amount of the solvent contained in the light-sensitive material according to the present invention is from 5 to 100 in total per m ² of the light-sensitive material.
It is preferable to adjust so as to be 0 mg / m ² . When the content is in the above range, a photosensitive material having high fog density and low fog density can be obtained.

(Exposure) In the present invention, in order to write image data on the photosensitive material, the exposure is preferably performed by laser scanning exposure. However, the angle between the exposure surface of the photosensitive material and the scanning laser beam is substantially perpendicular. It is preferable to use a laser scanning exposure machine which does not cause the problem.

Here, "it does not become substantially vertical"
Means an angle that is most perpendicular to the laser during laser scanning, preferably 55 to 88 degrees, more preferably 60 to 8 degrees.
6 degrees, more preferably 65-84 degrees, and most preferably 7 degrees.
0 to 82 degrees.

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

The exposure in the present invention is also preferably performed by 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. To achieve vertical multiplication, a method such as combining, using 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. There is no particular upper limit on the distribution of the exposure wavelength,
Usually, it is about 60 nm.

By these writing means, an image having less unevenness and excellent sharpness can be obtained.

(Development Processing) The development conditions of the light-sensitive material of the present invention vary depending on the composition, constitution, structure, etc. of the material to be used. This is done by heating at a temperature. The latent image formed by the exposure has a moderately high temperature (for example, about 80 to 250 ° C.,
By heating at a temperature of preferably about 100 to 200 ° C. for a sufficient time (generally about 1 second to about 2 minutes), a silver image is formed and visualized (developed). The heating may be performed by a typical heating means such as a hot plate, an iron, a heat roller, a heat generator using carbon or white titanium or the like. Among these, the method of carrying and heating and developing while contacting with a heat roller is preferable from the viewpoint of thermal efficiency and workability.

The heating of the light-sensitive material is preferably performed from the side of the protective layer from the viewpoint of heat transfer efficiency, and it is possible to avoid defects such as uneven heating due to heating from the support side and time required for heat transfer. Thus, a high-quality silver image can be obtained only by complete heating.

Hereinafter, the present invention will be described in detail with reference to examples.

[0097]

EXAMPLES [Preparation of Support] A 175 μm thick PET film colored blue with a concentration of 0.170 (measured with a densitometer PDA-65 manufactured by Konica Corp.)
A corona discharge treatment of W / m ² · min was performed to produce a support.

[Preparation of Photosensitive Silver Halide Emulsion A] (Solution A1) Phenylcarbamoylated gelatin 88.3 g Compound (A) (10% by mass methanol aqueous solution) 10 ml Potassium bromide 0.32 g Finish with water to 5429 ml (solution B1) 0.635 mol / L silver nitrate aqueous solution 2635 ml (solution C1) potassium bromide 51.55 g potassium iodide 1.47 g Make up to 660 ml with water (solution D1) potassium bromide 154.9 g potassium iodide 4.41 g iridium chloride (1% by mass solution) 0.93 ml Finish to 1982 ml with water (Solution E1) 0.4 mol / L aqueous potassium bromide solution Silver potential control amount below (Solution F1) Potassium hydroxide 0.71 g Finish to 20 ml with water (Solution G1) 18.0 ml of 56% by mass acetic acid aqueous solution (solution H1) anhydrous sodium carbonate Compounds finish 151ml with helium 1.72g water _{(A): HO (CH 2} CH 2 O) n - (CH (CH 3) CH 2 O) 17 - (C H 2 CH 2 O) m H where, m + n = 5-7.

JP-B-58-58288, 58-58
Using a mixing stirrer described in No. 289, 1/4 of the solution B1 and the entire solution C1 were added to the solution A1 at a temperature of 45 ° C. and pAg
While controlling at 8.09, the mixture was added by the simultaneous mixing method in 4 minutes and 45 seconds to form nuclei. One minute later, the entire amount of solution F1 was added. After a lapse of 6 minutes, the Ｂ amount of the solution B1 and the entire amount of the solution D1 were added over 14 minutes and 15 seconds by a simultaneous mixing method while controlling the temperature at 45 ° C. and the pAg at 8.09. After stirring for 5 minutes, the temperature was lowered to 40 ° C., and the whole amount of the solution G1 was added to precipitate a silver halide emulsion. The supernatant was removed, leaving 2000 ml of the sedimented portion, 10 liters of water was added, and the mixture was stirred, and the silver halide emulsion was sedimented again. The supernatant was removed, leaving 1500 ml of the sedimented portion, and 10 liters of water was further added. After stirring, the silver halide emulsion was sedimented. After removing the supernatant liquid leaving 1500 ml of the sedimented portion, the solution H1 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 became 1161 g per mol of silver, whereby photosensitive silver halide emulsion A was obtained. This emulsion was monodispersed 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 Organic Silver Salt Dispersion A] An organic silver salt dispersion A was prepared as follows using an apparatus shown in FIG. 1 which was modified based on Combimix SL-10 manufactured by Tokushu Kika Kogyo Co., Ltd. A was prepared.

The rotation speed of the anchor wing 2 is 100 rpm,
With the rotation speed of the dissolver mixer 3 and the homomixer 5 set to 1500 rpm, 130.8 g of behenic acid and 67.7 g of arachidic acid were added to 4720 ml of pure water in a reaction vessel.
43.6 g of stearic acid and 2.3 g of palmitic acid were added to 80
Dissolved at ° C. At this time, the rotational directions of the dissolver mixer 3 and the homomixer 5 were set to be opposite to each other. Next, a 1.5 mol / L sodium hydroxide aqueous solution 54
0.2 ml was added. Next, after adding 6.9 ml of concentrated nitric acid, the mixture was cooled to 55 ° C. to obtain a sodium organic acid solution.

The temperature of the above-mentioned organic acid sodium salt solution was 55
° C, while keeping the rotation speed of the anchor wing 2 at 100 rpm.
m, the rotational speeds of the dissolver mixer 3 and the homomixer 5 were each set to 5000 rpm, and 45.3 g of the photosensitive silver halide emulsion A and 450 ml of pure water were applied to the surface of the organic acid sodium solution in the reaction tank in 8 minutes. Added and stirred for 5 minutes. Next, 780.6 ml of a 1 mol / L silver nitrate aqueous solution was added to the liquid surface in the reaction tank over 2 minutes. Further, the rotational speeds of the dissolver mixer 3 and the homomixer 5 are each set to 450.
The mixture was stirred at 0 rpm for 10 minutes to obtain an organic silver salt dispersion.

Thereafter, the obtained organic silver salt dispersion was transferred to a washing vessel, deionized water was added thereto, and the mixture was stirred and allowed to stand. Then, the organic silver salt dispersion was floated and separated, and the lower water-soluble salts were removed. . Thereafter, washing with deionized water and draining are repeated until the conductivity of the waste water becomes 50 μS / cm, and after centrifugal dehydration, drying is performed at 40 ° C. using a hot-air circulating dryer until there is no change in mass. A powdery organic silver salt dispersion A was obtained.

[Preparation of Organic Silver Salt Dispersion B] In the preparation of the organic silver salt dispersion A, the photosensitive silver halide emulsion A, pure water and an aqueous solution of silver nitrate are placed not on the solution surface but near the homomixer 5 in FIG. A powdered organic silver salt dispersion B was prepared in exactly the same manner except that the addition was carried out through the opened nozzle 4 for addition in liquid.

[Preparation of photosensitive emulsion dispersions 1 and 2] Polyvinyl butyral powder (Butv, manufactured by Monsanto Co., Ltd.)
ar B-79) was dissolved in 1457 g of methyl ethyl ketone (hereinafter abbreviated as MEK) to give VMA-G.
Dissolver DISPERMAT C manufactured by ETZMANN
A-40 Powder organic silver salt dispersion A while stirring with a 40M type
A preliminary dispersion was prepared by gradually adding 500 g and mixing well. Then, a peripheral speed of 13 m / sec was set by a media type disperser (manufactured by gettzmann) filled with 80% of 1 mm diameter Zr beads (manufactured by Toray Industries, Inc.).
Dispersion was performed for 3 minutes in a mill to prepare a photosensitive emulsion dispersion liquid 1.

Photosensitive emulsion dispersion 2 was prepared in the same manner as in preparation of photosensitive emulsion dispersion 1, except that organic silver salt dispersion B was used instead of organic silver salt dispersion A.

[Preparation of stabilizer solution] 1.0 g of stabilizer 1,
0.31 g of potassium acetate was dissolved in 4.97 g of methanol to prepare a stabilizer solution.

[Preparation of infrared sensitizing dye solution] 19.2 mg of infrared sensitizing dye 1, 1.488 g of 2-chloro-benzoic acid, 2.779 g of stabilizer 2, and 365 mg of 5-methyl-2 31.3 ml of mercaptobenzimidazole
Was dissolved in MEK in a dark place to prepare an infrared sensitizing dye solution.

[Preparation of additive solution a] 27.98 g of reducing agent A-3, 1.54 g of 4-methylphthalic acid, 0.48 g
Was dissolved in 110 g of MEK to prepare an additive solution a.

[Preparation of Additive Solution b] An additive solution b was prepared by dissolving 2.56 g of the antifoggant 2, 3.43 g of phthalazine in 40.9 g of MEK.

[Preparation of Photosensitive Layer Coating Solutions 1 and 2] The above-mentioned photosensitive emulsion dispersion 1 (50 g) and 15.11 g of MEK were kept at 21 ° C. while stirring, and an antifoggant 1 (10% by mass) was prepared.
390 μl of methanol solution) was added, and the mixture was stirred for 1 hour.
Furthermore, calcium bromide (10% by mass methanol solution) 4
94 μl was added and stirred for 20 minutes. Then, after adding 167 mg of stabilizer liquids and stirring for 10 minutes, 2.622
g of the infrared sensitizing dye solution was added and stirred for 1 hour. Thereafter, the temperature was lowered to 13 ° C., and the mixture was further stirred for 30 minutes.
While keeping the temperature at 13 ° C, polyvinyl butyral (Mon
Santo Butvar B-79) 13.31 g
Was added and stirred for 30 minutes, and 1.084 g of tetrachlorophthalic acid (9.4% by mass MEK solution) was added to add 1
Stir for 5 minutes. While continuing stirring, 12.43
g of additive solution a, 1.6 ml of Desmodur N330
0 (Mobay's aliphatic isocyanate 10% by mass M
EK solution), and 4.27 g of Additive Solution b were sequentially added and stirred to obtain Photosensitive Layer Coating Solution 1.

A photosensitive layer coating liquid 2 was prepared in the same manner as in the preparation of the photosensitive layer coating liquid 1 except that the photosensitive emulsion dispersion liquid 2 was used in place of the photosensitive emulsion dispersion liquid 1.

[Preparation of Matting Agent Dispersion] Cellulose acetate butyrate (Eastman Chemical)
Co., Ltd., CAB171-15) 7.5 g of MEK 42.5 g
Dissolved in calcium carbonate (Special)
ity Minerals, Super-Pflex
200), and dispersed with a dissolver-type homogenizer at 8000 rpm for 30 minutes to prepare a matting agent dispersion.

[Preparation of Protective Layer Coating Solution] While stirring 865 g of MEK, cellulose acetate butyrate (Ea
stman Chemical, CAB171-1
5) 96 g, 4.5 g of polymethyl methacrylic acid (Rohm & Haas Co., Ltd., Paraloid A-21), 1.5 g of vinyl sulfone compound (HD-1), 1.0 of benzotriazole
g, F-based activator (Asahi Glass Co., Ltd., Surflon KH40)
0 g was added and dissolved. Next, 30 g of a matting agent dispersion was added and stirred to prepare a protective layer coating solution.

[0115]

Embedded image

[0116]

Embedded image

[Coating on photosensitive layer side] The photosensitive layer coating solution and the protective layer coating solution were applied so that the photosensitive layer had a coated silver amount of 1.9 g / m ² and the protective layer had a dry film thickness of 2.5 μm. Coating was performed simultaneously on the support using an extrusion coater. 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.

[Preparation of back surface coating solution] MEK 830 g
While stirring, cellulose acetate butyrate (E
astman Chemical, CAB 381-2
0) 84.2 g, polyester resin (Bostic,
(VitelPE2200B) 4.5 g was added and dissolved. To the solution, 0.30 g of infrared dye 1 was added, and further 4.5 g of an F-based activator (Asahi Glass Co., Ltd., Surflon KH40) dissolved in 43.2 g of methanol and an F-based activator (Dai Nippon Ink Co., Ltd., Megafag) F120K), and stirred thoroughly until dissolved. Finally, ME
Silica (WR Grace, Syroid 6) dispersed in a K at a concentration of 1% by mass with a dissolver type homogenizer.
(4 × 6000) was added and stirred to prepare a back surface coating solution.

[Coating of Back Surface] The back surface coating solution prepared as described above was applied to the back surface of the above-prepared coated sample of the photosensitive layer side by using an extrusion coater so that the dry film thickness became 3.5 μm. Was applied. Then, drying temperature 1
Drying was performed for 5 minutes using a drying air having a dew point of 10 ° C. at 00 ° C. to obtain photosensitive materials 1 and 2.

[Evaluation] (Measurement of solvent content in optical material) Photosensitive material 46.3 cm
² was cut out, finely chopped to about 5 mm, stored in a dedicated vial, sealed with a septum and an aluminum cap, and set in a Hewlett-Packard HP7694 headspace sampler. Gas chromatography (GC) connected to a headspace sampler
Used a Hewlett-Packard type 5971 equipped with a flame ionization detector (FID) as a detector. The main measurement conditions are as follows.

Headspace sampler heating condition: 120 ° C., 20 minutes GC introduction temperature: 150 ° C. Column: DB-624 manufactured by J & W Increasing temperature: 45 ° C., hold for 3 minutes, then 100 ° C. (8 ° C./8° C.)
Min) A gas chromatogram was obtained using the above measurement conditions. The solvent to be measured was MEK, methanol, and a certain amount of each solvent diluted with butanol was stored in a dedicated vial, and the calibration was performed using the peak area of the chromatogram obtained by measuring in the same manner as above. The solvent content in the film was obtained using a line.

(Uniformity of Organic Silver Salt) The organic silver salt dispersions A and B used in the above photosensitive material were diluted and dispersed by a conventional method, dispersed on a grid with a carbon support film, and then analyzed with a transmission electron microscope at 5000. Observed at × 2. Organic silver salt dispersion A
In Example 2, the particle size distribution of the organic silver salt particles was large, and some aggregation was observed. In the organic silver salt dispersion B, the particle size of the organic silver salt particles was uniform, and no aggregation was observed.

(Exposure and development processing) On the emulsion side of the photosensitive material prepared as described above, 800 to 82
Exposure was performed by laser scanning using an exposure machine using a semiconductor laser having a vertical multi-mode of 0 nm as an exposure source. At this time, an image was formed at an angle of 75 degrees between the exposure surface of the photosensitive material and the exposure laser beam. (Note that the angle is 9
An image with less unevenness and better sharpness and the like than expected was obtained as compared to the case where the angle was set to 0 degree. Thereafter, using an automatic developing machine having a heat drum, the protective layer of the photosensitive material and the drum surface are brought into contact with each other to obtain 11
The film was thermally developed at 0 ° C. for 15 seconds. At that time, exposure and development were performed in a room conditioned at 23 ° C. and 50 RH. The sensitivity (reciprocal of the exposure amount that gives a density higher than that of the unexposed portion by 1.0) and the fog of the obtained image were determined. The sensitivity is a relative value with the sensitivity of the photosensitive material 1 being 100, and the fog is shown as an actually measured value.

The results of the above measurement are shown in Table 1.

[0125]

[Table 1]

It can be seen that the organic silver salt prepared by the method of the present invention has high uniformity, and that the photographic material using this has low fog and high sensitivity.

[0127]

EFFECTS OF THE INVENTION A method and apparatus for uniformly forming an organic silver salt dispersion used for a photothermographic material, a photothermographic material having improved sensitivity and fog using the organic silver salt dispersion, An image recording method and an image forming method using a photothermographic material can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for producing an organic silver salt dispersion.

[Description of Signs] 1 Reaction tank 2 Anchor blade 3 Dissolver mixer 4 Nozzle 5 Homomixer 6 Jacket pot 7 Stirrer blade 8 Fixed ring 9 Rotating shaft 10 Direction of axial flow M Motor

Claims (10)

[Claims] 1. A method for producing an organic silver salt dispersion in which an aqueous solution or suspension of an alkali salt of an organic acid, a water-soluble silver salt and photosensitive silver halide are reacted in a reaction vessel. A method for producing an organic silver salt dispersion, comprising: two stirring members, and adding photosensitive silver halide through a nozzle provided near the stirring members. 2. Stirring along the inner wall or bottom of the reaction tank and stirring by at least one high-speed rotating high-speed stirring member are simultaneously performed, and the photosensitive halogen is stirred through a nozzle installed near the high-speed stirring member. The method for producing an organic silver salt dispersion according to claim 1, wherein silver halide is added. 3. The method for producing an organic silver salt dispersion according to claim 1, wherein the photosensitive silver halide grains are monodispersed. 4. The method for producing an organic silver salt dispersion according to claim 1, wherein a water-soluble silver salt is added after the addition of the photosensitive silver halide. 5. An apparatus for producing an organic silver salt dispersion in which an aqueous solution or suspension of an alkali salt of an organic acid and a water-soluble silver salt are reacted in a reaction vessel, wherein the apparatus has at least one stirring member. And a nozzle for adding photosensitive silver halide particles in the vicinity thereof, the apparatus for producing an organic silver salt dispersion. 6. A member for stirring along an inner wall or a bottom in a reaction vessel, at least one high-speed rotating high-speed stirring member, and a nozzle for adding photosensitive silver halide particles near the high-speed stirring member. The apparatus for producing an organic silver salt dispersion according to claim 5, characterized by comprising: 7. A photothermographic material comprising, on a support, a photosensitive layer containing an organic silver salt dispersion, a reducing agent and a binder, and a protective layer, wherein the organic silver salt dispersion comprises
A photothermographic material formed by the manufacturing method according to 3 or 4. 8. An image recording method comprising exposing the photothermographic material according to claim 7 to an exposure device in which an angle between an exposure surface and a scanning laser beam is not substantially perpendicular. 9. An image forming method, wherein the photothermographic material according to claim 7 is heat-developed in a state where a solvent is contained in an amount of 5 to 1000 mg / m ² . 10. An image forming method, comprising: bringing a protective layer of the photothermographic material according to claim 7 into contact with a heated drum to perform heat development.