JP2001042471A - Heat-developable photosensitive material, its manufacture, its processing method, and image forming and recording methods by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-developable photosensitive material high in sensitivity, low in fogging, good in tone, and superior in storage stability and image storage stability (especially, in the case of a black-and-white heat-developable photosensitive material), its manufacturing method, its processing method, and the methods for forming and recording the image by using them. SOLUTION: The head-developable photosensitive material contains photosensitive silver halide grains, organic silver grains, a reducing agent for silver ions, and a binder on a support, and transition metal atoms selected from groups VI-X of the periodic table exist in the photosensitive silver halide grains in an amount of >=1×10-6 and <1×10-2 mol/1 mol of the above silver halide grains, and these transition metals present in the outsides of the above silver halide grains in an amount of >=1×10-9 and <1×10-6 mol/1 mol the above silver halide grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photothermographic material,
The present invention relates to a manufacturing method, a processing method, an image forming method using the same, and an image recording method.

[0002]

2. Description of the Related Art In the medical field and the printing plate-making field, waste liquids caused by wet processing of image forming materials have become a problem in terms of workability. In recent years, the amount of processing waste liquids has been reduced from the viewpoint of environmental protection and space saving. Is strongly desired. Therefore, there is a need for a technology relating to a photothermographic material for photographic technology, which enables efficient exposure with a laser imager and a laser imagesetter and can form a high-resolution and clear black image. This technique includes, for example, U.S. Patent Nos. 3,152,904 and 3,487,075 and D.C. "Dry Silver Photograph" by Morgan
ic Materials) ”(Handbook o
f Imaging Materials, Marc
el Dekker, Inc. 48, 1991) are well known. These are photothermographic materials containing a photosensitive silver halide particle, an organic silver salt, a reducing agent of silver ion and a hydrophobic binder on a support, and are contained in order for the silver halide particle to have photosensitivity. ing. In this photosensitive material, a layer is formed by a binder which is softened by heat in order to form an image by causing physical dissolution development in the layer by heat, and an organic silver salt as a silver ion source and a photosensitive halide are formed in this layer. It is configured to contain silver particles, a reducing agent, and the like. When a photothermographic material having such a configuration is heated, silver halide exposed to light becomes a physical development nucleus, and an organic silver salt serving as a built-in silver ion source reacts with a reducing agent to develop the photothermographic material. Proceeds to form an image. It is characterized in that development proceeds without the supply of reagents, water, etc. from the outside, and that no fixing is performed. Therefore, it is possible to provide the user with a system that is simpler and does not damage the environment.

This photosensitive material is exposed by a laser imager or a laser imagesetter. Since exposure by this laser is a high-intensity short-time exposure, desensitization due to high-illuminance failure is a problem. It is widely known that photosensitive silver halide grains contained in a photothermographic material contain a transition metal complex such as iridium.

On the other hand, if these photothermographic materials are stored unused, problems such as fog, sensitivity and gradation change, and problems such as fog and color tone change upon storage after development. Although there are proposals for countermeasures, they are not practically sufficient, and further improvements have been desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photothermographic material (particularly a black-and-white photothermographic material) having high sensitivity, low fog, good color tone, excellent storage stability and excellent image storability. An object of the present invention is to provide a method, a processing method, an image forming method and an image recording method using the same.

[0006]

The above objects of the present invention have been attained by the following items 1 to 7.

[0007] 1. In a photothermographic material containing, on a support, photosensitive silver halide particles, organic silver particles, a reducing agent for silver ions, and a binder, the photothermographic material present in the photosensitive silver halide particles has a length of 6 to 10 in the periodic table. The transition metal selected from the group 10 elements is 1 per mol of the silver halide grains.
X 10 ^-6 mol or more and less than 1 x 10 ^-2 mol, and the transition metal present outside the photosensitive silver halide grains is 1 x 10 ^-9 mol per 1 mol of the photosensitive silver halide grains.
As described above, the photothermographic material is less than 1 × 10 ⁻⁶ mol.

[0008] 2. 2. The photothermographic material according to item 1, wherein the transition metal is a metal selected from iron, cobalt, ruthenium, rhodium, rhenium, osmium, and iridium.

3. 3. The photothermographic material according to item 1 or 2, wherein photosensitive silver halide particles contained in the photothermographic material are prepared using a hydrophilic colloid aqueous solution. Manufacturing method.

[0010] 4. 3. A method for processing a photothermographic material, wherein the photothermographic material according to the above item 1 or 2 is heat-developed at 80 to 140 ° C.

5. After the photothermographic material according to 1 or 2 above is exposed to infrared laser light, a processing temperature of 80 ° C. to 14 ° C.
An image forming method, wherein an image is obtained by performing a heat development process at 0 ° C.

6. 3. The photothermographic material according to item 1 or 2, wherein an exposure is performed by a laser exposing machine in which an angle formed by an infrared laser beam scanning with an exposure surface of the photothermographic material does not become substantially perpendicular. Image recording method.

7. 3. An image recording method, wherein an infrared laser beam to be scanned when recording an image on the photothermographic material according to 1 or 2 is exposed by a laser beam scanning exposure device having a vertical multi-scan.

Hereinafter, the present invention will be described in more detail.

The inventor of the present invention has found that the change in performance of a photothermographic material containing photosensitive silver halide particles containing a transition metal such as iridium when not in use or with time after development is determined by the photosensitive silver halide. The present inventors have found that it is caused by a transition metal in the light-sensitive material existing outside the grains, and have reached the present invention.

The photosensitive silver halide grains according to the present invention will be described.

In the present invention, the photosensitive silver halide particles function as an optical sensor. In order to suppress white turbidity after image formation and obtain good image quality,
The smaller the average particle size, the more preferable. Specifically, the average value of the sphere-equivalent diameter is preferably from 0.0001 μm to 0.1 μm, more preferably from 0.001 μm to 0.1 μm.
μm or less, more preferably 0.001 μm or more, 0.0
It is more preferably at most 8 μm. The ratio of particles having a particle size of 0.1 μm or more is preferably 15% or less, more preferably 10% or less, and further preferably 5% or less.

The sphere-converted diameter referred to here is defined in J. Org.
F. Hamilton, Photo. Sci. En
g. , 11 (1967), 57; Shiozaw
a. Sci. Photo. Sci. Japan, 35
(1972) 213, that is, observation and photographing were performed using a transmission electron microscope at a low temperature, and a projection image of the particles was obtained by the method described in US Pat. No. 4,434,226.
The diameter when converted to a circular image of the same area was measured, and the average value was obtained for all the measured particles.

In the size distribution of the silver halide grains according to the present invention, the coefficient of variation of the sphere-converted diameter (the standard deviation of the diameter divided by the average diameter) is preferably 30% or less.
It is more preferably at most 20%, further preferably at most 15%, most preferably at most 10%.

The shape of the silver halide grains is not particularly limited, but it is preferable that the ratio occupied by the Miller index [100] plane is high, and this ratio is 50% or more, and more preferably 7%.
It is preferably at least 0%, particularly preferably at least 80%. The ratio of the Miller index [100] plane is determined by T.M. using the dependence of adsorption of the photosensitive dye on the [111] plane and the [100] plane. Tani, J .; Imaging Sci. , 29,
165 (1985).

Another preferred form of silver halide is tabular grains. The term “tabular grain” as used herein means that the thickness in the vertical direction is h when the square root of the projected area is the particle size r μm.
The aspect ratio = r / h in the case of μm is 3 or more. Among them, the aspect ratio is preferably 3 or more,
50 or less. The particle size is preferably 0.1 μm or less, and more preferably 0.01 μm to 0.08 μm. These are described in U.S. Pat. Nos. 5,264,337, 5,314,798, and 5,320,958, and can easily obtain target tabular grains. When these tabular grains are used in the present invention, the sharpness of an image is further improved.

The halogen composition of the silver halide grains is preferably silver bromide, silver iodobromide or silver chloroiodobromide. Silver iodide content is from 0.01 mol% to 10 mol%
It is preferably at most 0.1 mol%, more preferably at least 0.1 mol% and at most 5 mol%.

The grains may be core / shell grains having different halogen compositions between the core layer and the shell layer. In this case, the silver iodide content of the shell layer is preferably equal to or more than the silver iodide content of the core layer. The halogen composition in the grains can be determined by an X-ray diffraction method, a composition analysis method using EPMA, or the like.

Next, a method for preparing photosensitive silver halide grains will be described.

A method for preparing a silver halide emulsion containing photosensitive silver halide grains according to the present invention (hereinafter, also referred to as a silver halide emulsion used in the present invention) is described in US Pat. Chimie et P by Glafkids
hysique Photographique (Pa
ul Montel, 1967); F. Du
Photographic Emulsi by fin
on Chemistry (The Focal Pr
ess, 1966); L. Zelikman
Making and Coating by et al
Photographic Emulsion (The
Focal Press, 1964) and the like, and the silver halide emulsion used in the present invention can be prepared using these methods. That is, any of an acidic method, a neutral method, an ammonia method, etc. may be used, and a method of reacting a soluble silver salt with a soluble halide salt includes:
Any of a one-side mixing method, a simultaneous mixing method, a combination thereof and the like may be used. Typically, a silver halide emulsion is prepared by mixing a silver salt aqueous solution and a halide aqueous solution in a protective colloid (a hydrophilic colloid such as gelatin is used) serving as a reaction mother liquor, and performing nucleation and crystal growth. As a method for adding an aqueous halide solution or an aqueous silver salt solution, a double jet method is generally used. Among these, the controlled double jet method of mixing the components while controlling pAg and pH to perform the above nucleation and crystal growth is typical. Also, first, seed particles are prepared (nucleation), and then this growth is performed under the same conditions or under another condition (crystal growth or ripening).
It includes various variations, such as a two-stage method. In short, it is well known in the art that the crystal habit and size are variously controlled by defining the mixing conditions of the silver salt aqueous solution and the halide aqueous solution in the mixing step in the protective colloid aqueous solution. Following these mixing steps, a desalting step of removing excess salts from the prepared emulsion is performed. As a desalting step, silver halide grains are coagulated and precipitated together with gelatin as a protective colloid by adding a coagulant to the prepared silver halide emulsion,
A flocculation method for separating this from a supernatant containing salts is well known. The supernatant is removed by decantation, and further, dissolution, flocculation, and decantation are repeated in order to remove excess salts contained in the gelatin coagulated product containing the aggregated and precipitated silver halide particles. A method for removing soluble salts by ultrafiltration is also well known. As will be described later, by using an ultrafiltration membrane, a method of removing unnecessary salts having a low molecular weight by using a synthetic membrane that does not transmit large particles such as silver halide particles and gelatin and molecules having a large molecular weight is used. is there.

A method for adding a transition metal according to the present invention will be described.

In the present invention, 6 to 10 of the periodic table of the elements are used.
It is preferable to add a transition metal selected from Group III elements in the form of a complex. The transition metal complex is represented by the following general formula 6
Coordination complexes are preferred.

In the general formula [ML ₆ ] ^m , M is a transition metal selected from elements of Groups 6 to 10 of the periodic table, L is a bridging ligand, and m is 0,-, 2- or 3
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. The transition metals may be used alone or in combination.

The above-mentioned M is cobalt (C
o), ruthenium (Ru), rhodium (Rh), rhenium (Re), osmium (Os) and iridium (I
r) and the like, more preferably rhodium (R
h), iridium (Ir), and particularly preferably used is iridium (Ir).

The transition metal complex ion ([ML ₆ ] ^m )
Are shown, but the present invention is not limited to these.

[0031] 1: [RhCl _6] ^3- 2: [RuCl _6] ^3- 3: [ReCl _6] ^3- 4: [RuBr _6] ^3- 5: [OsCl _6] ^3- 6: [CrCl _6] ^{4 -} 7: [IrCl _6] ^4- 8: [IrCl _6] ^3- 9: [Ru (NO) Cl _5] ^2- 10: [RuBr ₄ (H ₂ O)] ^2- 11: [Ru (NO) ( H ₂ O) Cl _4] ^- 12: [RhCl ₅ (H ₂ O)] ^2- 13: [Re (NO) Cl _5] ^2- 14: [Re (NO) (CN) _5] ^2- 15: [ Re (NO) ClCN _4] ^2- 16: [Rh (NO) ₂ Cl _4] ^- 17: _{[Rh (NO) (H 2 O} ) Cl 4 ] ^- 18: [Ru (NO) (CN) _5] ^{2 -} 19: [Rh (NS) Cl _5] ^2- 20: [Os (NO) Cl _5] ^2- 21: [Cr (NO) Cl _5] ^2- 22: [Re (NO) Cl _5] ^- 23: [Os (NS) C l ₄ (TeCN)] ^2- 24: [Ru (NS) Cl _5] ^2- 25: _{[Re (NS) Cl 4 (SeCN} ) ] ^2- 26: [Os (NS) Cl (SCN) 4 ] ^2- 27: [Ir (NO) Cl ₅ ] For a compound of ^2- cobalt and iron, a 6-cyano metal complex can be preferably used. Specific examples are shown below.

28: [Fe (CN) ₆ ] ^4- 29: [Fe (CN) ₆ ] ^3-30 : [Co (CN) ₆ ] ^3- Compounds that provide ions or complex ions of these transition metals It is 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 addition at any stage before and after chemical sensitization However, it is preferably added at the stage of nucleation, crystal growth and physical ripening, and more preferably at the stage of nucleation and growth. During the addition, it may be added in several divided portions, may be uniformly contained in the silver halide grains, may be added, or may be added to JP-A-63-29603, JP-A-2-306236,
3-167545, 4-76534, 6-1
As described in JP-A Nos. 10146 and 5-273683 and the like, the particles can be contained in the particles with distribution. Preferably, the particles can have a distribution.
These transition metal compounds may be water or a suitable organic solvent (eg, alcohols, ethers, glycols,
Ketones, esters, amides), and may be added, for example, an aqueous solution of a transition metal compound powder or a transition metal compound and NaX (X = Cl, Br),
An aqueous solution of KX (X = Cl, Br) dissolved together
A method of adding to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or adding a third solution when a silver salt solution and a halide solution are simultaneously mixed, and a method of simultaneous mixing of three liquids A method of preparing silver halide grains, a method of charging a required amount of an aqueous solution of a transition metal compound into a reaction vessel during grain formation, or another method of doping a transition metal ion or complex ion in advance during silver halide preparation. There is a method in which silver halide grains are added and dissolved. In particular, an aqueous solution of a transition metal compound powder or a transition metal compound and NaX (X = Cl, Br), KX (X = Cl, B
A preferred method is to add an aqueous solution in which r) is dissolved together to a water-soluble halide solution. When adding to the particle surface,
A required amount of an aqueous solution of a transition metal compound can also be charged into the reaction vessel immediately after the formation of the particles, during or at the end of physical ripening, or at the time of chemical ripening.

When the transition metal is contained in the silver halide grains by these methods, the addition amount of the transition metal is not always taken into 100% of the silver halide grains. Transition metal not contained in the silver halide grains is present in the solution in the mixing step and is removed in the desalting step. However, it is not completely removed, and as a result, it is presumed that the transition metal exists in the photosensitive material outside the silver halide grains.

Regarding the distribution of the transition metal described above in the silver halide grains,
It may be uniform or may have a distribution, but it is preferable that the amount of transition metal per unit volume of silver halide grains on the surface and / or in the vicinity of the surface is larger than or equal to that of the inside.

In the present invention, the surface of the silver halide grains refers to the inner 10 lattices from the surface of the silver halide grains, and the vicinity of the surface refers to the inner 20 lattices.

The concentration distribution of the transition metal in the silver halide grains can be determined by gradually dissolving the grains from the surface to the inside and measuring the content of the transition metal in each part. Specific examples include the method described below.

Prior to the determination of the transition metal, the silver halide emulsion is pretreated as follows. First, 50 ml of a 0.2% actinase aqueous solution is added to about 30 ml of the emulsion, and the mixture is stirred at 40 ° C. for 30 minutes to perform gelatin decomposition. This operation 5
Repeat several times. After centrifugation, 5 times with 50 ml of methanol,
Washing is repeated twice with 50 ml of 1N nitric acid and five times with ultrapure water. After centrifugation, only silver halide is separated. The surface portion of the obtained silver halide grains is dissolved with an aqueous ammonia solution or ammonia whose pH has been adjusted (the ammonia concentration and pH are changed according to the type and amount of silver halide to be dissolved). As a method for dissolving the extreme surface of silver bromide grains in silver halide, about 1 g of silver halide is dissolved in 2 g of silver halide.
About 20% of the particles can be dissolved by using 20 ml of 0% aqueous ammonia. At this time, the amount of silver halide dissolved was determined by centrifuging the aqueous ammonia solution after dissolving the silver halide and the silver halide, and determining the amount of silver present in the obtained supernatant by a high frequency induction plasma mass spectrometer. (ICP-MS) It can be quantified by high frequency induction plasma emission spectrometry (ICP-AES) or atomic absorption. From the difference between the amount of metal contained in the silver halide after surface melting and the total amount of transition metal of silver halide not dissolved, the amount of transition metal per mol of silver halide existing at about 3% of the grain surface is determined. be able to. As a method for quantifying a transition metal, an ICP-MS which is dissolved in an aqueous solution of ammonium thiosulfate, an aqueous solution of sodium thiosulfate, or an aqueous solution of potassium cyanide and subjected to matrix matching is used.
Method, ICP-AES method, or atomic absorption method. Among them, potassium cyanide was used as a solvent, and ICP-MS (FISON Elemental) was used as an analyzer.
(Analysis Co., Ltd.), about 40 mg of silver halide is dissolved in 5 ml of 0.2N potassium cyanide, and then an internal standard element Cs solution is added thereto at 10 ppb, and the volume is adjusted to 100 ml with ultrapure water. Is used as a measurement sample. Then, the transition metal in the measurement sample is quantified by ICP-MS using a calibration curve obtained by combining a matrix using transition metal-free silver halide. At this time, the exact amount of silver in the measurement sample can be determined by ICP-AES or atomic absorption of the measurement sample diluted 100 times with ultrapure water. After such dissolution of the grain surface, the silver halide grains were washed with ultrapure water, and the dissolution of the grain surface was repeated in the same manner as described above, whereby the transition in the silver halide grain internal direction was performed. The amount of metal can be determined.

By combining the above transition metal determination method with the well-known particle observation using an electron microscope, it is possible to determine the transition metal doped in the peripheral region of the silver halide grains used in the present invention. .

In the present invention, the amount of transition metal in the silver halide grains is set to 1 × 1 per mol of the silver halide grains.
0 ^-6 mol or more, 1 while a × 10 ^-2 below mol, the amount of the transition metal outside said silver halide grains 1 × 10 ^-9 mol or more, in order to 1 × 10 ^-6 mol / less molAgX is In the mixing step, it is preferable to add 1 × 10 ⁻⁶ mol or more of transition metal per 1 mol of silver halide grains and remove the transition metal by the following method. When using a plurality of metals as the transition metal, the content of the transition metal described above,
The total number is used to count the number of moles.

(1) Increasing the Number of Flocculation Methods After the mixing step, increasing the number of repetitions of flocculation and decantation in the flocculation method increases the degree of desalination and reduces the amount of transition metal remaining. Let it.

Although the number of repetitions is not generally determined by various conditions, it is preferably at least three times, more preferably at least five times.

(2) The gelatin used in the mixing step is a low molecular weight gelatin, and the gelatin is removed in the desalting step.

Preferred desalting methods are flocculation method and ultrafiltration method. In particular, ultrafiltration method is preferably used. After the desalting, if the amount of gelatin used during mixing is small, the amount of transition metal existing outside the silver halide grains can be reduced. This is presumably because the transition metal adsorbed on the gelatin is removed together with the gelatin.

In the case of the ultrafiltration method, it is preferable to control the amount of low molecular weight gelatin by controlling the cutoff molecular weight of the ultrafiltration membrane and the time of ultrafiltration.

As the low molecular gelatin, gelatin having a molecular weight of 30,000 or less is preferably used. A step of mixing the silver salt aqueous solution and the halide solution using these low molecular weight gelatins instead of ordinary gelatins (nucleation and crystal growth)
In the desalting step, the amount of gelatin can be reduced as described above by a method of removing low molecular weight gelatin together with soluble salts by ultrafiltration. Ie nucleation,
At the time of crystal growth, it is preferable to use an aqueous solution containing gelatin having a molecular weight of 30,000 or less. The content of gelatin at the time of nucleation and growth is preferably 1.6% by weight or more based on the reaction mother liquor. As the kind of gelatin, alkali-treated gelatin is usually used, but other acid-treated gelatin, ion-exchanged gelatin, and gelatin made from fish can also be used.

The molecular weight distribution and average molecular weight of gelatin can be measured by a general method, for example, gel filtration chromatography.

The molecular weight of gelatin can be controlled by a generally known method such as hydrolysis with acid or alkali, enzymatic decomposition, coacervation method, and cleavage of cross-linking by ultrasonic irradiation. In the enzymatic digestion, a specific binding position of a gelatin molecular chain is cleaved, so that a low-molecular-weight gelatin having a relatively narrow molecular weight distribution can be obtained, and the average molecular weight can be adjusted by the enzymatic digestion time. Is preferred. For enzymatic degradation,
R. J. Cox; Photographic Gela
tin II, Academic Press, London
on, 1976, pp. 233-251, 335-346.
Page for the coacervation method, Pourad
ir; Chem. Phys. 47 volumes, 391 pages, 4
The method described in Vol. 9, page 85 can be referred to.

The ultrafiltration used in the present invention will be described. The term "ultrafiltration" is described in M.E. Cheyan, Ul
Trafiltration Handbook "(Technomic Publishing Co., 1986). This filtration method generally uses a membrane,
This membrane allows the passage of unwanted substances. For example, in the purification of a colloidal silver dispersion, a purification method using a membrane that allows unnecessary salts and the like to pass therethrough without passing through a necessary substance such as colloidal silver.

In this selective separation, the solution is hydraulically pressed against a synthetic semi-permeable membrane made so that all particles smaller than a specific size are selectively passed and larger particles are retained. Performed by

Ultrafiltration membranes are permeable only to molecules of a certain size or smaller and contain pores sized to retain larger molecules and silver halide grains in the dispersion. The ultrafiltration is preferably carried out by circulating the dispersion in the reaction vessel in contact with the semipermeable ultrafiltration membrane so that a pressure difference is created across the semipermeable ultrafiltration membrane. In general, the membrane is permeable to only molecules of a certain size or smaller and contains pores sized to retain larger molecules and silver halide grains in the dispersion. Suitable membranes are preferably about 500 to 300,00
0 or more, more preferably about 500 to 5
It can be selected from those exhibiting transmission cutoff characteristics in the molecular weight range of 000.

In practicing the present invention, the cut-off molecular weight can be easily varied outside this range. It will be readily appreciated that this cut-off molecular weight should generally not be greater than the molecular weight for the protective colloid. In general,
The choice of a particular transmission cut-off molecular weight depends on the silver halide particle size at the beginning of the ultrafiltration and the small molecular weight material (retentat) that needs to be retained in the emulsion.
e)).

[0052] The pressure of the emulsion in contact with the ultrafiltration membrane may be varied over a wide range. Typically, for the practice of the present invention, the pressure in the reaction vessel that contacts the ultrafiltration membrane is preferably between about 100 psi and 500 psi, typically about 100 psi (7.03 kg / cm ² ). Yes,
The outlet pressure of the retentate is preferably between about 5 psi and 10 p
si or less, typically about 10 psi (0.703 kg
/ Cm ² ) or less. The pressure differential across the membrane is typically about 40-60 psi (2.81-4.22 kg / c).
m ² ). Needless to say, those skilled in the art can arbitrarily set according to the structure of the reaction vessel and the ultrafiltration membrane, the viscosity of the emulsion, the concentration of the retentate, and the desired purity of the retentate.

That is, the silver halide and excess salts suspended in the protective colloid in the container are removed by known means.
It is pumped through a flow meter into an ultrafiltration module, the excess salts being withdrawn as filtrate, while the residues recirculate into the vessel during a recycle operation mode.

In another approach, a number of ultrafiltration modes can be connected in series so that the residue from the previous module is fed into the next module's inlet line.

Prior to subsequent flow of the liquid through each module, the liquid can be rediluted with a solvent for desalting and washing purposes, or, alternatively, the solvent can be diluted for concentration purposes. No need to re-dilute.

When performing concentration and desalting by ultrafiltration, the temperature is preferably 60 ° C. or lower, more preferably 20 ° C. or higher and 50 ° C. or lower.
It is below ° C.

When the concentration and desalting are performed by the ultrafiltration method, the time required from the start to the end of the concentration / desalting is a total of 2 times.
It is preferably 10 minutes or less, more preferably 190 minutes or less. At this time, a filtrate containing excess salts is taken out, and the drainage rate is preferably 15 ml / min or more, more preferably 17 ml / min or more, even more preferably 20 ml / min or more per 1 mol of silver.

The amount of the emulsion used for concentration and desalting by ultrafiltration is 5 to 2,000 mol, preferably 100 to 1,000 mol, as silver.

The membrane used for ultrafiltration is typically an anisotropic membrane comprising very thin walls of a very fine porous structure supported on a thicker porous structure. Useful membranes are
Various polymer substances, for example, polyvinyl chloride, polyvinyl carboxylate, polyvinyl formate, polyvinyl acetate, polyvinyl alcohol, polysulfone, polyvinyl ether, polyacrylamide, polyimide, polyester,
Polyfluoroalkylene (eg, polytetrafluoroethylene), and polyvinylidene fluoride, and any cellulosic polymer such as cellulose and cellulose esters such as cellulose acetate, cellulose butyrate, and cellulose acetate butyrate. Can be something.

(3) The hydrophilic colloid used in the mixing step is a polymer compound having a protective colloid property other than gelatin.

The amount of the transition metal existing outside the silver halide grains can be reduced by this method, which is presumed to be because the polymer has no interaction with the transition metal.

The following compounds are used as the polymer compound having a protective colloid property for the silver halide grains used in the present invention.

A. Polyacrylamide polymer Homopolymer of acrylamide, U.S. Pat. No. 2,54
No. 1,474, a copolymer of polyacrylamide and imidized polyacrylamide; a copolymer of acrylamide and methacrylamide shown in West German Patent 1,202,132; U.S. Pat. No. 3,284,20
Partially aminated acrylamide polymer disclosed in JP-B-45-14031, U.S. Pat.
No. 13,834, 3,746,548 and British Patent No. 788,343. Aminopolymer US Patent Nos. 3,345,346 and 3,706,5
No. 4,350,759, West German Patent No. 2,138,872, etc .; British Patent No. 1,413,125; US Patent No. 3,42.
No. 5,836, etc., a polymer having a quaternary amine, No. 3,511,818, a polymer having an amino group and a carboxyl group, and No. 3,832,18
Polymer No. 5 C.I. Polymers having thioether groups US Pat. Nos. 3,615,624 and 3,860,4
No. 28, No. 3,706,564, etc. and polymers having a thioether group. Polyvinyl alcohol Homopolymer of vinyl alcohol, U.S. Pat.
0,741 organic acid monoester of polyvinyl alcohol, maleic acid ester described in 3,236,653, and copolymerization of polyvinyl alcohol and polyvinylpyrrolidone described in 3,479,189. Things E. Acrylic acid polymer Acrylic acid homopolymer, US Pat. No. 3,832,18
No. 5, No. 3,852,073, acrylate polymer having an amino group, and No. 4,131,
No. 471, a halogenated acrylate polymer, and a cyanoalkyl acrylate polymer described in 4,120,727. Polymers having hydroxyquinoline US Pat. Nos. 4,030,929 and 4,152,1
Polymer having hydroxyquinoline shown in No. 61 G. Cellulose, derivatives of starch British Patent Nos. 542,704 and 551,659,
U.S. Pat. Nos. 2,127,573 and 2,311,0
No. 86, No. 2,322,085, derivatives of cellulose or starch. Acetal US Patents 2,358,836 and 3,003,8
Nos. 79 and 2,828,204; British Patent 77
No. 1,155, polyvinyl acetal. Polyvinylpyrrolidone Homopolymer of vinylpyrrolidone, French Patent No. 2,
Copolymer of acrolein and pyrrolidone shown in JP-A-031,396. Polystyrene A polystyrylamine polymer disclosed in U.S. Pat. No. 4,315,071, a halogenated styrene polymer disclosed in U.S. Pat. No. 3,861,918. Imidazole polymer JP-B Nos. 43-7561, 47-25374, 5
2-16365, German Patent No. 2,012,0
Nos. 95 and 2,012,970 and polymers having a vinylimidazole group. Others Azaindene group-containing vinyl polymer disclosed in JP-A-59-8604, polyalkylene oxide derivatives disclosed in U.S. Pat.
No. 2,623, No. 4,294,920 and No. 4,089,68.
No. 8, No. 2,484,456, polyvinyl pyridine, No. 3,520,857
No. 1 vinyl polymer having an imidazole group,
No. 60-658, a vinyl polymer having a triazole group, a copolymer of polyvinyl-2-methylimidazole and acrylamide-imidazole described in Journal of the Photographic Society of Japan, Vol. 29, No. 1, p. Water-soluble polyalkyleneaminotriazoles, etc., shown in Hie Photography, Vol. 45, p. 43 (1950).

Of these, A.I. Polyacrylamide polymer, C.I. A polymer having a thioether group; Polyvinyl alcohol, F.I. A polymer having hydroxyquinoline; Cellulose, starch derivatives; Acetal, I. Polyvinylpyrrolidone, J.I. Polystyrene, K. Imidazole polymers and the like are preferably used.

The amount of the high molecular compound other than gelatin having a protective colloid used in the present invention is not particularly limited, but is preferably 1 to 150 g, more preferably 2 to 80 g, and more preferably 2 to 80 g per mol of silver halide. 3-20g
Is preferred.

In the present invention, the mixing step is carried out in the presence of a polymer compound having a protective colloid property. At that time, the content of gelatin is preferably at most 10 g per mol of silver halide, and contains no gelatin at all. More preferably, no.

(4) The amount of gelatin in the mixing step is reduced, and the amount brought into the desalting step is reduced.

The amount of gelatin in the mixing step is preferably as small as possible as long as the protective colloid property during mixing can be maintained. Specifically, 1 to 1 mol of silver halide
It is preferable to prepare silver halide grains using 100 g of gelatin, more preferably 3 to 45 g, and 5 to 4 g.
0 g is more preferred.

Among these methods (1) to (4), more preferred are (2) to (4), and furthermore, (2)
(3) is preferred.

In the present invention, the exposure is preferably performed by infrared laser scanning exposure. However, the infrared laser scanning exposure does not make the angle between the exposed surface of the photosensitive material and the scanning infrared laser beam substantially vertical. It is preferable to use an exposure machine.

Here, "not substantially vertical" means that the angle is most vertical during infrared laser scanning, preferably 55 to 88 degrees, more preferably 60 to 8 degrees.
6 degrees, more preferably 65 degrees to 84 degrees, and most preferably 70 degrees to 82 degrees.

The beam spot diameter on the exposed surface of the photosensitive material when the infrared laser beam is scanned on the photosensitive material is preferably 200 μm or less, more preferably 100 μm or less. This is preferable in that the spot diameter is small in that the shift angle of the infrared laser incident angle from the perpendicular can be reduced.
Note that the lower limit of the beam spot diameter is 10 μm.

By performing such infrared laser scanning exposure, it is possible to reduce image quality deterioration due to reflected light such as occurrence of unevenness like interference fringes.

The exposure in the present invention is also preferably performed using an infrared laser scanning exposure device that emits infrared laser light that is a vertical multi. Image quality deterioration such as generation of interference fringe-like unevenness is reduced as compared with the scanning infrared 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. Note that 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 exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

The organic silver salt according to the present invention is a reducible silver source and is an organic acid containing a reducible silver ion source.
Examples of the organic acid used in the present invention include an aliphatic carboxylic acid, a carbocyclic carboxylic acid, a heterocyclic carboxylic acid, a heterocyclic compound and the like, and particularly a long chain (10 to 30, preferably 15 to 25 (Carbon atoms) aliphatic carboxylic acids and heterocyclic carboxylic acids having a nitrogen-containing heterocyclic ring are preferably used. Further, an organic silver salt complex in which the ligand has a total stability constant for silver ions of 4.0 to 10.0 is also useful.

Examples of the silver salt of an organic acid according to the present invention include R
Escher Disclosure Nos. 17029 and 29996, and include: silver salts of fatty acids (eg, silver salts of gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid, etc.). A carboxyalkylthiourea salt of silver (eg, 1- (3-carboxypropyl) thiourea, 1-
(3-carboxypropyl) -3,3-dimethylthiourea, etc.); a silver complex of a polymerization reaction product of an aldehyde and a hydroxy-substituted aromatic carboxylic acid (for example, an aldehyde (formaldehyde, acetaldehyde, butyraldehyde, etc.) and a hydroxy-substitution) Silver complexes or the like of polymerization reaction products with aromatic carboxylic acids (for example, salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid, etc.), and silver salts or complexes of thiones (for example, ,
3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione and 3-carboxymethyl-4-thiazoline-2-thione)), imidazole, pyrazole, urazole, 1,2,4- Complexes or salts of nitrogen acids and silver selected from thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole and benzotriazole; silver salts such as saccharin and 5-chlorosalicylaldoxime And silver salts of mercaptides. Among the organic silver salts described above, silver salts of fatty acids are preferably used, and silver behenate, silver arachidate and silver stearate are more preferably used.

The dispersion of the aqueous organic silver salt used in the present invention can be obtained by mixing silver nitrate and an alkali metal salt of an organic acid. When the organic silver salt is formed, silver nitrate and silver halide are simultaneously added and mixed. It is preferably produced using a mixing method.

For example, after an alkali metal hydroxide (eg, sodium hydroxide, potassium hydroxide, etc.) is added to an organic acid to prepare an organic acid alkali metal salt soap (eg, sodium behenate, sodium arachidate, etc.) By using a control double jet method, silver nitrate and silver halide can be simultaneously added and mixed to prepare an aqueous organic silver salt dispersion used in the present invention.

Further, the aqueous organic silver salt dispersion used in the present invention can be prepared by a so-called control triple jet method in which an alkali metal salt of an organic acid, silver nitrate and silver halide are simultaneously added and mixed, respectively. .

In the present invention, from the viewpoint of simplicity in the production process, the method for producing an aqueous organic silver salt dispersion using the above-described controlled double jet method is preferably used. From the viewpoint of producing a high-sensitivity photothermographic material, the method for producing an aqueous organic silver salt dispersion using the above-described control triple jet method is preferably used.

The photothermographic material of the present invention preferably contains a reducing agent. Examples of suitable reducing agents are described in U.S. Patent Nos. 3,770,448, 3,773,512,
No. 3,593,863 and Research D
No. 17029 and 29996, and include the following: Aminohydroxycycloalkenones (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones esters (eg, piperidinohexose reductone monoacetate) as precursors of reducing agents; N- Hydroxyurea derivatives (eg, Np-methylphenyl-N-hydroxyurea); hydrazones of aldehydes or ketones (eg, anthracenaldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (Eg, hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone, and (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (eg, benzenesulfhydroxam) ); Sulfonamides anilines (e.g., 4-(N-
Methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (for example, 2-methyl-5- (1-
Phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (e.g., 1,2,3,4-
Amidooxins; Azines (for example, a combination of an aliphatic carboxylic acid arylhydrazide and ascorbic acid); a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine; Hydroxamic acids; Azines and sulfone Combinations of amidophenols; α-cyanophenylacetic acid derivatives; bis-β-naphthol and 1,3
5-pyrazolones; sulfonamidophenol reducing agents; 2-phenylindane-1,3-dione and the like; chromans;
Dihydropyridines (for example, 2,6-dimethoxy-
3,5-dicarbethoxy-1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, bis (6-hydroxy-m-tri) mesitol (Mesi
tol), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,5-ethylidene-bis (2-
t-butyl-6-methyl) phenol), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among them, particularly preferred reducing agents are hindered phenols.
Examples of the hindered phenols include compounds represented by the following general formula (A).

[0082]

Embedded image

In the formula, R is a hydrogen atom or a group having 1 to 1 carbon atoms.
Represents an alkyl group of 10 (eg, butyl group, 2,4,4-trimethylpentyl group, etc.), and R ′ and R ″ represent an alkyl group having 1 to 5 carbon atoms (eg, methyl group, ethyl group, t- Butyl group).

Specific examples of the compound represented by formula (A) are shown below. However, the present invention is not limited to these.

[0085]

Embedded image

[0086]

Embedded image

The amount of the reducing agent including the compound represented by formula (A) is preferably 1 × 1 per mol of silver.
It is from 0 ^-2 to 10 mol, especially from 1 x 10 ^{-2 to} 1.5 mol.

The photothermographic material of the present invention may contain an antifoggant. Known as an effective antifoggant is mercury ion, and the use of a mercury compound as an antifoggant in a light-sensitive material is disclosed in, for example, US Pat. No. 3,589,903. However, mercury compounds are environmentally unfavorable and are, for example, disclosed in U.S. Patent Nos. 4,546,075 and 4,452.
Non-mercury antifoggants such as those disclosed in JP-A-885-85 and JP-A-59-57234 are preferably used in the present invention.

Particularly preferred non-mercury antifoggants include US Pat. Nos. 3,874,946 and 4,753.
No. 6,999, the compound -C (X
₁ ) Heterocyclic compounds having at least one substituent represented by (X ₂ ) (X ₃ ) (where X ₁ and X ₂ each represent a halogen atom, and X ₃ represents hydrogen or a halogen atom). Can be

Other suitable antifoggants include paragraph No. [0030] of JP-A-9-288328.
To [0036], JP-A-9-9
Compounds described in paragraph Nos. [0062] to [0063] of US Pat. No. 0550, US Pat. No. 5,028,523 and European Patent Nos. 600,587 and 605,981.
And the compounds disclosed in JP-A-631,176 and the like can be used.

It is preferable to add a toning agent to the photothermographic material of the present invention for the purpose of improving the silver tone after development. Examples of suitable toning agents are Research Discl
No. 17029, which includes the following:

Imides (eg, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (eg, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and , 4-thiazolidinedione); naphthalimides (e.g., N-hydroxy-1,8-naphthalimide); cobalt complexes (e.g., hexamine trifluoroacetate of cobalt), mercaptans (e.g., 3
-Mercapto-1,2,4-triazole); N- (aminomethyl) aryldicarboximides (for example,
N- (dimethylaminomethyl) phthalimide); blocked pyrazoles, isothiuronium (isoth
uronium) derivatives and certain photobleaches (eg, N, N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8-
A combination of (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole; a merocyanine dye (e.g., 3-ethyl-5-((3-ethyl -2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2,4
Oxazolidinedione); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example, 4-
(1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3
-Dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); phthalazine + phthalate Combinations of acids; phthalazine (including adducts of phthalazine) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivatives and anhydrides thereof (for example,
Combination with at least one compound selected from phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; quinazolinediones, benzoxazine, naloxazine 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). Preferred toning agents are phthalazone or phthalazine.

The photothermographic materials of the present invention include, for example, JP-A-63-159841, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, and JP-A-6-259561.
3-304242, 63-15245, U.S. Pat. Nos. 4,639,414 and 4,740,455,
Nos. 4,741,966 and 4,751,175
No. 4,835,096.

Useful sensitizing dyes for use in the present invention include, for example, Research Disclosure Item
17643 IV-A (p. 23, December 1978), and Item 18431 (p. 437, August 1979), etc. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, JP-A-9-34078, JP-A-9-54409, and JP-A-9-806
The compounds described in No. 79 are preferably used.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. be able to.

When a mercapto compound is used in the present invention, it may be of any structure,
Those represented by -SS-Ar are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar represents an aromatic ring or a condensed aromatic ring having at least one nitrogen, sulfur, oxygen, selenium or tellurium atom.

As the aromatic ring, an aromatic carbon ring and a heteroaromatic ring are used. In the present invention, a heteroaromatic ring is preferably used. As the heteroaromatic ring, for example, benzimidazole, naphthymidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, Pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring includes, for example, a halogen atom (eg, Br and Cl), a hydroxy group, an amino group, a carboxy group, an alkyl group (eg, one or more carbon atoms, preferably
Having a substituent selected from the group consisting of those having from 1 to 4 carbon atoms) and alkoxy groups (e.g., having at least one carbon atom, preferably having from 1 to 4 carbon atoms). Is also good. Examples of the mercapto-substituted heteroaromatic compound include 2-mercaptobenzimidazole and 2-mercaptobenzimidazole.
Mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzothiazole, 3-mercapto-1,2,4-triazole,
-Mercaptoquinoline, 8-mercaptopurine, 2,
3,5,6-tetrachloro-4-pyridinethiol,
-Hydroxy-2-mercaptopyrimidine, 2-mercapto-4-phenyloxazole and the like,
The present invention is not limited to these.

In the present invention, a matting agent is preferably contained on the photosensitive layer side, and it is preferable to provide a matting agent on the surface of the photosensitive material in order to prevent the image after thermal development from being damaged. It is preferred that the composition contains 0.5 to 30% by weight of the agent with respect to all binders on the emulsion layer side.

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, Swiss Patent No. 3
Silica described in No. 30,158, French Patent No. 1,29
No. 6,995, etc., British Patent No. 1,17
Alkaline earth metals or carbonates such as cadmium and zinc described in 3,181 and the like can be used as a matting agent. As organic substances, US Pat. No. 2,322,03
7, starch derivatives described in Belgian Patent No. 625,451 and British Patent No. 981,198, polyvinyl alcohol described in Japanese Patent Publication No. 44-3643, and Swiss Patent No. 330,158. Polystyrene or polymethacrylate described in U.S. Pat.
Organic matting agents such as polyacrylonitrile described in No. 79,257 and polycarbonate described in U.S. Pat. No. 3,022,169 can be used.

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

The matting agent used in the present invention preferably has an average particle size of 0.5 μm to 10 μm, more preferably 1.0 μm to 8.0 μm. The matting agent has a coefficient of variation of the particle size distribution of preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.

Here, the variation coefficient of the particle size distribution is a value represented by the following equation.

(Standard deviation of particle size) / (average value of particle size) × 100 The matting agent used in the present invention can be contained in any constituent layer, but in order to achieve the object of the present invention, It is preferably a constituent layer other than the photosensitive layer, and more preferably the outermost layer as viewed from the support.

The method of adding the matting agent used in the present invention may be a method in which the matting agent is dispersed in a coating solution in advance and the matting agent may be sprayed after the coating solution is applied and before drying is completed. May be used. When a plurality of types of matting agents are added, both methods may be used in combination.

In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be contained in the constituent layer in order to improve the chargeability. These may be contained in any layer, but are preferably contained in an undercoat layer, a backing layer, a layer between the photosensitive layer and the undercoat, and the like.

In the present invention, US Pat.
The conductive compounds described in No. 773 columns 14 to 20 are preferably used.

Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other constituent layers. In the photothermographic material of the present invention, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid, and the like may be used in addition to the above. These additives and the other additives mentioned above are used in Research Disclosure.
re Item 17029 (June 1978, p. 9-
The compound described in 15) can be preferably used.

The binder suitable for the photothermographic material of the present invention is transparent or translucent, generally colorless, and includes natural polymer synthetic resins, polymers and copolymers, and other film-forming media, for example: gelatin, gum arabic, poly (Vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid) , Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinylacetal) s (eg, poly (vinylformal) and poly (vinylbutyral)), poly (ester) Kind, poly ( Urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxides),
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides). It may be hydrophilic or non-hydrophilic. In order to protect the surface of the light-sensitive material and prevent abrasion, a non-light-sensitive layer may be provided outside the light-sensitive layer. The binder used for these non-photosensitive layers may be the same or different from the binder used for the photosensitive layers.

In the present invention, the binder amount of the photosensitive layer is preferably 1.5 to 10 g / m ² in order to increase the speed of thermal development. More preferably, 1.7 to 8 g /
m ² .

The support used in the present invention may be a plastic film (for example, polyethylene terephthalate, polycarbonate, or the like) in order to prevent deformation of an image after development processing.
Polyimide, nylon, cellulose triacetate, polyethylene naphthalate) are preferred.

Among them, a preferred support is a support of polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) containing a styrene-based polymer having a syndiotactic structure. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.

A plastic support that has been heat-treated can also be used. The plastics to be employed include the above-mentioned plastics. The heat treatment of the support means that after forming these supports and before the photosensitive layer is applied, at a temperature higher than the glass transition point of the support by 30 ° C. or more,
Preferably at a temperature higher than 35 ° C., more preferably 40 ° C.
It is preferable to heat at a temperature higher than ℃. However, the effect of the present invention cannot be obtained by heating at a temperature exceeding the melting point of the support.

Next, the plastic used will be described.

PET is composed of polyethylene terephthalate as the polyester component. In addition to polyethylene terephthalate, terephthalic acid, naphthalene-2,6-dicarboxylic acid, isophthalic acid, butylene dicarboxylic acid, and 5-sodium sulfo acid are used as acid components. A polyester containing a modified polyester component of isophthalic acid, adipic acid or the like and a glycol component such as ethylene glycol, propylene glycol, butanediol, cyclohexanedimethanol or the like in an amount of 10 mol% or less of the entire polyester may be used.

SPS is a polystyrene having steric regularity unlike ordinary polystyrene (atactic polystyrene). The regular stereoregular structure part of SPS is called a racemo chain, and it is preferable that there are more regular parts such as two, three, five or more. In the present invention, the racemo chain is 2 It is preferably 85% or more in the chain, 75% or more in the three chains, 50% or more in the five chains, and 30% or more in the further chains. The polymerization of SPS can be carried out according to the method described in JP-A-3-131843.

As the method of forming a film of a support and the method of producing an undercoat used in the present invention, known methods can be used. Preferably, the method described in paragraph [0030] of JP-A-9-50094 is used.
To [0070].

The photothermographic material of the present invention is for forming a photographic image by a heat development process, and comprises a reducible silver source (organic silver salt), a photosensitive silver halide, a reducing agent and, if necessary, silver. It is preferable that the photothermographic material contains a color-toning agent which suppresses the color tone of the present invention, usually in a dispersed state in an (organic) binder matrix. The photothermographic material of the present invention is stable at room temperature, but is exposed to high temperature (for example,
(° C.). Heating generates silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is accelerated by the catalytic action of the latent image generated on the silver halide upon exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. This reaction process proceeds without supplying a processing liquid such as water from the outside.

The photothermographic material of the present invention has at least one photosensitive layer on a support. Although only a photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. To control the amount or wavelength distribution of light passing through the photosensitive layer, a filter dye layer on the same side as the photosensitive layer and / or an antihalation dye layer, a so-called backing layer, may be formed on the opposite side. A dye or pigment may be included in the active layer. As the dye to be used, any compound may be used as long as it has a desired absorption in a desired wavelength range, and examples thereof include JP-A-59-6481 and JP-A-59-1.
No. 82436, U.S. Pat. No. 4,271,263, U.S. Pat. No. 4,594,312, European Patent Publication 533,0
08, European Patent Publication 652,473, JP-A-2-2-2
No. 16140, JP-A-4-348339, JP-A-7-
Compounds described in JP-A-191432 and JP-A-7-301890 are preferably used.

These non-photosensitive layers preferably contain the above-mentioned binder and matting agent, and may further contain a sliding agent such as a polysiloxane compound, wax and liquid paraffin.

The light-sensitive layer may be composed of a plurality of layers, and the sensitivity may be changed to a high-sensitivity layer / low-sensitivity layer or a low-sensitivity layer / high-sensitivity layer for adjusting the gradation.

Details of the photothermographic material are described in, for example, US Pat. Nos. 3,152,904 and 3,457,
No. 075, and D.A. “Dry Silver Photographic Materials (Dry Silver P) by Morgan
photographic Material) ”and D.C.
Morgan and B.A. Shelley
y) "Heat treated silver system (The
rally Processed Silver S
systems) "(Imaging Processes and Materials)
es and Materials) Neblette
Eighth Edition, Sturge, V.S. Walworth, A .; Shep
p) Edit, page 2, 1969).
Among them, in the present invention, the photosensitive material is 80 to 140
It is characterized in that an image is formed by heat development at a temperature of ° C. and no fixing is performed. Therefore, the silver halide and the organic silver salt remaining in the unexposed area remain in the photosensitive material without being removed.

In the present invention, after the heat development,
The optical transmission density of the light-sensitive material containing the support at 400 nm is preferably 0.2 or less. A more preferable value of the optical transmission density is 0.02 or more and 0.2 or less.

[0124]

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

Example 1 (Preparation of Photosensitive Silver Halide Emulsion 1) A1 Phenylcarbamoyl gelatin (average molecular weight 100,000) 88.3 g Compound (A) (10% aqueous methanol solution) 10 ml Potassium bromide 0.13 g 5429 ml with water B1 0.67N aqueous silver nitrate solution 2635ml C1 Potassium bromide 51.55g Potassium iodide 1.47g Finish to 505ml with water D1 Potassium bromide 154.9g Potassium iodide 4.41g 2 Potassium iridium chloride 6% (1% solution) E1 0.4N Potassium bromide aqueous solution E1 0.4N Potassium bromide aqueous solution The following silver potential control amount F1 Potassium hydroxide 0.71 g Finished with water to 20 mL G1 56% acetic acid aqueous solution The following pH adjustment amount H1 Potassium hydroxide 1.88 g Water Finish to 151ml with Compound ( _{): HO (CH 2 CH 2} O) n - (CH (CH 3) CH 2 O) 17 - (C H 2 CH 2 O) m H m + n = 5~7 B Nos 58-58288, the 58-58289 Solution (B1) was added to solution (A1) using the mixing stirrer indicated
を amount and the whole amount of the solution (C1) 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 the solution (F1) was added.
After a lapse of 6 minutes, 3/4 of the solution (B1) and the solution (D
The entire amount of 1) was added over 14 minutes and 15 seconds by a double jet method while controlling the temperature to 45 ° C. and the pAg to 8.09.

After stirring for 5 minutes, the temperature was lowered to 40 ° C., pH was adjusted to 4.3 by adding solution G1, and the silver halide emulsion was sedimented. The supernatant liquid was removed, leaving 2000 ml of the sedimented portion, 10 liters of water was added, and after stirring, the silver halide emulsion was sedimented again. Leaving 1500 ml of sedimentation,
After removing the supernatant, the solution (H1) was added,
And stirred for another 100 minutes. Finally, the temperature was lowered to 40 ° C. and adjusted to pH 5.8 and pAg 8.22.
Water was added so as to be 1161 g per mole of silver.

The silver halide grains contained in this emulsion had an average grain size of 0.060 μm and a variation coefficient of grain size of 1
Cubic silver iodobromide grains of 2% and [100] face ratio of 92% were obtained. The amount of iridium contained in the silver halide grains was 8.2 × 10 ^-6 mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 1.times.10.sup.- ⁶ per mol of silver.
It was 6 × 10 ^-6 mol.

(Preparation of photosensitive silver halide emulsion 2) In the preparation of photosensitive silver halide emulsion 1, desalting was carried out in the same manner as in emulsion 1 except that the desalting after the completion of mixing was changed as follows. Was.

That is, after stirring for 5 minutes after the completion of mixing,
The temperature was lowered to ° C., pH was adjusted to 4.3 by adding solution G1, and the silver halide emulsion was precipitated. The supernatant liquid was removed, leaving 2000 ml of the sedimented portion, 10 liters of water was added, and after stirring, the silver halide emulsion was sedimented again. Settling part 15
The supernatant was removed, leaving 00 ml, and 10 liters of water was further added. After stirring, the silver halide emulsion was sedimented.
Further, the supernatant was removed, leaving 1500 ml of the sedimented portion, 10 liters of water was added, and after stirring, the silver halide emulsion was sedimented. After removing the supernatant, leaving 1500 ml of sedimented portion, the solution (H1) was added,
The temperature was raised to ° C. and the mixture was stirred for 100 minutes. Finally, the temperature was lowered to 40 ° C. and adjusted to pH 5.8 and pAg 8.22.
Water was added so as to be 1161 g per mole of silver.

The silver halide grains contained in this emulsion had an average grain size of 0.060 μm and a variation coefficient of grain size of 1
Cubic silver iodobromide grains of 2% and [100] face ratio of 92% were obtained. The amount of iridium contained in the silver halide grains was 8.2 × 10 ⁻⁶ mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 0.1 × 10 ⁶ mol per mol of silver.
It was 9 × 10 ^-6 mol.

(Preparation of Photosensitive Silver Halide Emulsion 3) In the preparation of photosensitive silver halide emulsion 2, the following steps for desalting, ie, "removing the supernatant, leaving 1500 ml of sedimented portion, A light-sensitive silver halide emulsion 3 was prepared in the same manner as in the emulsion 2, except that the step of "adding 1 liter and stirring and then precipitating the silver halide emulsion" was further performed twice.

The silver halide grains contained in this emulsion had an average grain size of 0.060 μm and a variation coefficient of grain size of 1
Cubic silver iodobromide grains of 2% and [100] face ratio of 92% were obtained. The amount of iridium contained in the silver halide grains was 8.2 × 10 ⁻⁶ mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 0.1 × 10 ⁶ mol per mol of silver.
It was 5 × 10 ^-6 mol.

(Preparation of powdered organic silver salts 1 to 3) 4720 m
111.4 g of behenic acid and 83.Arachidic acid in 1 l of pure water.
8 g and 54.9 g of stearic acid were dissolved at 80 ° C. Next, while stirring at a high speed, 540.2 ml of a 1.5 M aqueous sodium hydroxide solution was added, 6.9 ml of concentrated nitric acid was added, and the mixture was cooled to 55 ° C. to obtain a sodium fatty acid solution. While maintaining the temperature of the fatty acid sodium solution at 55 ° C., the above-described photosensitive silver halide emulsions 1, 2, and 3
450 ml of pure water was added to each (containing 0.038 mol of silver) and stirred for 5 minutes. Next, each 1 M silver nitrate solution 7
60.6 ml was added over 2 minutes, stirred for another 20 minutes, and the water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration were repeated until the conductivity of the filtrate became 2 μS / cm, centrifugal dehydration was performed, and then hot air drying was performed at 37 ° C. until weight loss was stopped. ~ 3.

(Preparation of photosensitive emulsion dispersion liquids 1 to 3) Polyvinyl butyral powder (BUTVAR, SOLUTIA)
B-79) 14.57 g of methyl ethyl ketone 1457
g, and stirred with a dissolver-type homogenizer, 50 g of each of the powdered organic silver salts 1, 2 and 3 described above.
0 g was added slowly and mixed well. Thereafter, dispersion was performed at a peripheral speed of 13 m and a residence time in the mill for 0.5 minute by a media type disperser (manufactured by gettzmann) filled with 80% of Zr beads (manufactured by Toray) having a diameter of 1 mm. 3 was prepared.

(Preparation of photographic support) Concentration: 0.170
(Measured with a densitometer PDA-65 manufactured by Konica Corporation) A corona discharge treatment of 8 W / m ² · min was applied to both sides of a 175 μm thick PET film colored blue.

(Coating of Photosensitive Layer) (Preparation of Coating Solutions 1 to 3) The above-mentioned photosensitive emulsion dispersion (500 g) and methyl ethyl ketone (MEK) 10
0 g was kept at 21 ° C. while stirring.

Pyridinium bromide perbromide (PH
P, 0.45 g) and stirred for 1 hour.

Further, calcium bromide (3.25 ml of a 10% methanol solution) was added, and the mixture was stirred for 30 minutes.

Next, a mixed solution of infrared sensitizing dye 1, 2-chlorobenzoic acid and a supersensitizer (5-methyl-2-mercaptobenzimidazole) (mixing ratio 1: 250:
20, 0.1% methanol solution with sensitizing dye (7 ml) was added, and the mixture was stirred for 1 hour, and then the temperature was lowered to 13 ° C. and further stirred for 30 minutes.

While keeping the temperature at 13 ° C., 48 g of polyvinyl butyral was added and dissolved sufficiently, and then the following additives were added.

Reducing agent A-4 (1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3-methyl-5,5-dimethylhexane) 15 g Sumidur N3300 (Sumitomo Bayer Urethane Co., aliphatic) Isocyanate) 1.10 g Phthalazine 1.5 g Tetrachlorophthalic acid 0.5 g 4-Methylphthalic acid 0.5 g

[0143]

Embedded image

[0144]

Embedded image

After preparing the photosensitive layer coating solutions 1 to 3 in this manner, the solution was kept at 13 ° C. and kept stagnant for 15 minutes, and then applied by the following method. Further, the following layers were sequentially formed on a support to prepare a sample. In addition, each drying was performed at 75 ° C. for 5 minutes.

(Back surface side coating) (Preparation of back surface coating solution) 830 g of methyl ethyl ketone
While stirring the cellulose acetate butyrate (E
Astman Chemical, CAB381-2
0) 84.2 g, polyester resin (Bostic,
(VitelPE2200B) 4.5 g was added and dissolved. 0.30 g of infrared dye 1 was added to the dissolved solution, and 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), 2.3 g, and stirred thoroughly until dissolved. Finally, silica dispersed in methyl ethyl ketone at a concentration of 1 wt% with a dissolver type homogenizer (WR Grace,
(Syloid 64 x 6000) was added and stirred to prepare a coating solution for the back surface.

The coating solution for the back surface thus prepared was extruded and dried with a coater so that the dry film thickness became 3.5 μm. Drying was performed for 5 minutes using a drying air having a drying temperature of 100 ° C. and a dew point of 10 ° C.

(Surface protective layer coating) (Preparation of dispersion) Cellulose acetate butyrate (E
Astman Chemical Company, CAB171-1
5) Dissolve 7.5 g in 42.5 g of MEK, in which
Calcium carbonate (Specialty Minera)
5 g of Super-Pflex 200 (Iss. Co., Ltd.) was added, and the mixture was treated with a dissolver-type homogenizer at 8,000 rpm.
The mixture was dispersed for 0 minutes to prepare a calcium carbonate dispersion.

(Preparation of Surface Protective Layer Coating Solution) Cellulose acetate butyrate (Eastman Chemical) was stirred in 865 g of methyl ethyl ketone (MEK).
3. Company CAB171-15) 96 g, polymethylmethacrylic acid (Rohm & Haas Co., Paraloid A-21) 4.
5 g was added and dissolved. 1.5 g of vinyl sulfone compound HD-1 and 1.0 g of benzotriazole were added to this liquid,
F-based activator (Asahi Glass Co., Surflon KH40) 1.0
g was added and dissolved. Finally, the calcium carbonate dispersion 3
0 g was added and stirred to prepare a coating solution for the surface protective layer.

(Coating on photosensitive layer surface side)
3 and a coating solution for the surface protective layer were simultaneously coated using an extrusion coater. The photosensitive layer has a coated silver amount of 1.9 g / m ² , and the surface protective layer has a dry thickness of 2.5 μm.
m at a speed of 20 m / min. Thereafter, using a drying air having a drying temperature of 75 ° C. and a dew point temperature of 10 ° C., 10
After drying for 1 minute, photosensitive materials 1 to 3 were prepared.

(Evaluation of Photosensitive Material) << Evaluation of Sensitometry >> The photosensitive materials 1 to 3 obtained by the above method were subjected to laser scanning exposure by an exposure machine using a semiconductor laser having a wavelength of 810 nm as an exposure source. Side to the photosensitive material. 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. After performing exposure by laser under the above conditions, heat development was performed at 120 ° C. for 15 seconds in a heat developing apparatus having a heat drum. After the development, measurement was performed with a densitometer PDA-65 manufactured by Konica Corporation to measure fog and sensitivity. The sensitivity was represented by the reciprocal of the ratio of the exposure amount giving a density higher than fog by 1.0.

<< Evaluation of Color Tone >> The color tone of the obtained image was visually evaluated based on the following evaluation criteria.

(Visual Evaluation Criteria of Color Tone) 5: Bluish, no problem in the market at all 4: Bluish, level acceptable enough in the market 3: Slightly yellowish, problem pointed out in the market Level of concern 2: Yellowish color, problematic level indicated in the market 1: Strong yellowish color, not acceptable in the market << Evaluation of image preservability >> The obtained image was left under indoor light for two days. The fog of the unexposed portion was measured again, and the storability of the image was evaluated. At the same time, the color tone was evaluated again based on the above evaluation criteria.

<< Evaluation of Storage >> In addition to the above evaluation, one set of samples was prepared and placed in a light-shielding container at 50 ° C. and a relative humidity of 55%.
After storage for days, sensitometry and color evaluation were similarly performed on the exposed and developed ones.

Table 1 shows the above results. The sensitivity is shown as a relative value when the value immediately after storage of the photosensitive material 1 is set to 100.

[0156]

[Table 1]

From Table 1, it can be seen that, compared to Comparative Sample 1, the sample of the present invention has low fog, high sensitivity and excellent color tone, and its characteristics are maintained even after storing the processed photographic material or after storing the unused photographic material. You can see that it is done.

Example 2 (Preparation of photosensitive silver halide emulsion 4) In the preparation of photosensitive silver halide emulsion 1, the gelatin of the solution (A1) in the mixing step was changed to phenylcarbamoyl gelatin having an average molecular weight of 25,000. Iridium chloride (1) of (D1)
% Solution) was changed to 1.9 ml in the same manner as in the case of the photosensitive silver halide emulsion 1.
Was prepared.

The silver halide grains contained in this emulsion had an average grain size of 0.060 μm and a variation coefficient of grain size of 1
Cubic silver iodobromide grains of 2% and [100] face ratio of 92% were obtained. The amount of iridium contained in the silver halide grains was 16.4 × 10 ^-6 mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 3.0 × 10 ^-6 mol per mol of silver. Met. The amount of gelatin contained per mole of silver in the silver halide emulsion was 48.
It was 5 g.

(Preparation of Photosensitive Silver Halide Emulsion 5) In the preparation of the photosensitive silver halide emulsion 4, the mixture was stirred for 5 minutes after the completion of mixing, and then cooled to 40 ° C. Concentration and desalting were performed using a filtration membrane. After desalting, a 15% by weight aqueous solution of the same gelatin as the gelatin used in the mixing step was added so that the amount of gelatin contained per mole of silver in the emulsion was 48.5 g, followed by pH 5.8 and pAg 8.8. Adjust it to be 22,
Further, water was added so as to be 1161 g per mol of silver, whereby a photosensitive silver halide emulsion 5 was obtained.

The silver halide grains contained in Emulsion 5 were cubic silver iodobromide grains having an average grain size of 0.060 μm, a grain size variation coefficient of 12%, and a [100] face ratio of 92%. The amount of iridium contained in the silver halide grains was 16.4 × 10 ⁻⁶ mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 0.1 × 10 ⁻⁶ mol per mol of silver. Met.

A photothermographic material was prepared using the above emulsions 4 and 5. The photosensitive material was produced by the same manufacturing method as in Example 1, and was evaluated in the same manner as in Example 1. Table 2 shows the results. Note that the sensitivity is 10 when the photosensitive material 4 is stored immediately.
It is assumed to be 0 and indicated by a relative value.

[0163]

[Table 2]

From Table 2, it can be seen that the amount of iridium present outside the silver halide grains in the emulsion desalted by ultrafiltration using low molecular weight gelatin was within the range used in the present invention. Sample 5 of the invention has low fog, high sensitivity and excellent color tone, and it can be seen that the characteristics are maintained after the image of the processed light-sensitive material is stored and after the unused light-sensitive material is stored.

Example 3 (Preparation of Photosensitive Silver Halide Emulsion 6) In the preparation of photosensitive silver halide emulsion 5, gelatin was used in an average molecular weight of 250.
Photosensitive silver halide emulsion 6 was obtained in the same manner as in emulsion 5, except that the ossein gelatin was changed to 00, and the ultrafiltration membrane was changed to one having a cutoff molecular weight of 40,000, followed by concentration and desalting.

The silver halide grains contained in Emulsion 6 were cubic silver iodobromide grains having an average grain size of 0.060 μm, a grain size variation coefficient of 12%, and a [100] face ratio of 92%. The amount of iridium contained in the silver halide grains was 16.4 × 10 ⁻⁶ mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 0.01 × 10 ⁻⁶ mol per mol of silver. Met.

(Preparation of photosensitive silver halide emulsions 7 to 9)
A 0.1% iridium chloride solution was added to the photosensitive silver halide emulsion 6 to prepare photosensitive silver halide emulsions 7 to 9 in which the amount of iridium existing outside the silver halide grains was changed. All of the silver halide grains contained in the emulsions 7 to 9 are cubic silver iodobromide grains having an average grain size of 0.060 μm, a variation coefficient of the grain size of 12%, and a [100] face ratio of 92%. Was 16.4 × 10 ^-6 mol per mol of silver. The amount of iridium contained outside the silver halide grains was as follows.
0.05 × 10 ^-6 mole per mole, Emulsion 8 was 0.5 × 10 ^-6 mole per silver mole, and Emulsion 9 was ^5.5 × 10 ^-6 mole per silver mole.
It was 0 × 10 ^-6 mol.

A heat-developable photosensitive material was prepared using the above emulsions 7 to 9. The photosensitive material was produced by the same manufacturing method as in Example 1, and was evaluated in the same manner as in Example 1. Table 3 shows the results. Note that the sensitivity is 10 when the photosensitive material 9 is stored immediately.
It is assumed to be 0 and indicated by a relative value.

[0169]

[Table 3]

From Table 3, it can be seen that when the amount of iridium present outside the silver halide grains is within the range used in the present invention, low fog and high sensitivity, excellent color tone, and further after image storage or raw storage It can be seen that these characteristics are also maintained.

Example 4 (Preparation of photosensitive silver halide emulsion 10) In the preparation of photosensitive silver halide emulsion 5, gelatin was prepared with an average molecular weight of 12
Sensitized silver halide emulsion 10 in the same manner as photosensitive silver halide emulsion 5 except that
Was prepared.

The silver halide grains contained in Emulsion 10 were 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 90%. The amount of iridium contained in the silver halide grains was 16.4 × 10 ^-6 mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 3.3 × 10 ^-6 mol per mol of silver. Met.

(Preparation of Photosensitive Silver Halide Emulsion 11) In the preparation of the photosensitive silver halide emulsion 10, ossein gelatin having an average molecular weight of 120,000 was changed to polyvinyl alcohol having an average molecular weight of 120,000, and a solution (B1) was prepared. (C1),
A light-sensitive silver halide emulsion 11 was prepared in the same manner as in the preparation of the light-sensitive silver halide emulsion 10, except that the addition time of (D1) was changed.

The silver halide grains contained in Emulsion 11 were 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 90%. The amount of iridium contained in the silver halide grains was 16.4 × 10 ⁻⁶ mol per mol of silver, and the amount of iridium contained outside the silver halide grains was 0.05 × 10 ⁻⁶ mol per mol of silver. Met.

A heat-developable light-sensitive material was prepared using the above emulsions 10 to 11. The photosensitive material was produced by the same manufacturing method as in Example 1, and the evaluation was performed in the same manner as in Example 1. Table 4 shows the results. The sensitivity is shown as a relative value when the value immediately after storage of the photosensitive material 10 is 100.

[0176]

[Table 4]

The silver halide emulsion prepared using polyvinyl alcohol has an amount of iridium existing outside the silver halide grains within the range used in the present invention, has low fog and high sensitivity, and is excellent in color tone. Further, it can be seen that these characteristics are maintained even after image storage or raw storage.

Example 5 (Preparation of photosensitive silver halide emulsion 12) In the preparation of photosensitive silver halide emulsion 1, the gelatin of the solution (A1) in the mixing step was changed to phenylcarbamoyl gelatin having an average molecular weight of 25,000. Photosensitive silver halide emulsion 1 was prepared in the same manner as photosensitive silver halide emulsion 1 except that dipotassium iridium hexachloride (1% solution) of (D1) was changed to 1.3 ml of rhodium triammonium hexachloride (1% solution). 1
2 was prepared.

The silver halide grains contained in this emulsion had an average grain size of 0.060 μm and a variation coefficient of grain size of 1
Cubic silver iodobromide grains of 2% and [100] face ratio of 92% were obtained. The amount of rhodium contained in the silver halide grains was 17.2 × 10 ^-6 mol per mol of silver, and the amount of rhodium contained outside the silver halide grains was 2.1 mol / mol of silver.
× 10 ^-6 mol. The amount of gelatin contained per mole of silver in the silver halide emulsion was 48.5 g.

(Preparation of Photosensitive Silver Halide Emulsion 13) In the preparation of the photosensitive silver halide emulsion 12, the mixture was stirred for 5 minutes after the completion of mixing, and then cooled to 40 ° C. Concentration and desalting were performed using a filtration membrane. After desalting, a 15% by weight aqueous solution of the same gelatin as the gelatin used in the mixing step was added so that the amount of gelatin contained per mole of silver in the emulsion was 48.5 g,
Subsequently, the pH was adjusted to 5.8 and the pAg was 8.22, and water was added so as to be 1161 g per mol of silver to obtain a photosensitive silver halide emulsion 13.

The silver halide grains contained in this emulsion 13 were cubic silver iodobromide grains having an average grain size of 0.060 μm, a grain size variation coefficient of 12%, and a [100] face ratio of 92%. The amount of rhodium contained in the silver halide grains was 17.2 × 10 ⁻⁶ mol per mol of silver, and the amount of rhodium contained outside the silver halide grains was 0.1 × 10 ⁻⁶ mol per mol of silver. Met.

A photothermographic material was prepared using the above emulsions 12 and 13. The photosensitive material was produced by the same manufacturing method as in Example 1, and was evaluated in the same manner as in Example 1. Table 5 shows the results. The sensitivity is shown as a relative value when the value immediately after storage of the photosensitive material 12 is 100.

[0183]

[Table 5]

It can be seen that Sample 13 of the present invention has low fog and high sensitivity and excellent color tone, and furthermore, these characteristics are maintained even after image storage or raw storage.

[0185]

According to the present invention, a photothermographic material (especially a black-and-white photothermographic material) having high sensitivity, low fog, good color tone, excellent storage stability and excellent image storability, its production method and processing method, And an image recording method using the same.

Claims (7)

[Claims] A photosensitive silver halide grain on a support,
In a photothermographic material containing organic silver particles, a reducing agent for silver ions, and a binder, a transition metal selected from elements belonging to Groups 6 to 10 of the periodic table, which is present in the photosensitive silver halide particles, contains the halogen. 1 × 1 per mol of silver halide particles
0 ^-6 mol or more, 1 × less than 10 ^-2 mol, the transition metal is 1 × 10 ^-9 mol or more per light-sensitive silver halide grains 1mol present outside said photosensitive silver halide grains, 1 × A photothermographic material characterized in that the amount is less than 10 ^-6 mol. 2. The method according to claim 1, wherein the transition metal is iron, cobalt, ruthenium,
The photothermographic material according to claim 1, wherein the photothermographic material is a metal selected from rhodium, rhenium, osmium, and iridium. 3. The photothermographic material according to claim 1, wherein the photosensitive silver halide particles contained in the photothermographic material are prepared using a hydrophilic colloid aqueous solution. A method for producing a photothermographic material. 4. A method for processing a photothermographic material, comprising subjecting the photothermographic material according to claim 1 to heat development at 80 ° C. to 140 ° C. 5. A processing temperature of 80 ° C. to 14 ° C. after exposing the photothermographic material according to claim 1 to infrared laser light.
An image forming method, wherein an image is obtained by performing a heat development process at 0 ° C. 6. A laser exposing machine wherein the angle between an infrared laser beam and a scanning surface of the photothermographic material according to claim 1 or 2 does not become substantially perpendicular. An image recording method comprising performing exposure. 7. An image characterized in that an infrared laser beam to be scanned when recording an image on the photothermographic material according to claim 1 or 2 is exposed by a laser beam scanning exposure device which is a vertical multi. Recording method.