JP2002090955A - Photosensitive silver halide emulsion and photosensitive material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silver halide photographic emulsion for digital exposure exposed in a short exposure time and causing no unevenness in image and to provide a photosensitive material using the emulsion. SOLUTION: The photosensitive silver halide emulsion has such characteristics that >=3 inflection points are present in the range from logarithmic light exposure giving the minimum density to logarithmic light exposure giving the maximum density and the inclinations (tanθ) of tangent lines drawn on the inflection points are alternately >=3 and <=1 in a characteristic curve showing the relation between logarithmic light exposure and density. A silver halide photographic sensitive material using the emulsion is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide photographic emulsion suitable for a digital exposure light source and a photographic material using the same. In particular, it relates to a photothermographic material.

[0002]

2. Description of the Related Art Digital image output systems have become more and more important in recent years, and typical ones are silver halide printers such as Frontier and Pictography manufactured by Fuji Photo Film Co., Ltd. In addition, there are an inkjet method using no silver salt, a sublimation heat-sensitive method, a TA method, and the like. Photosensitive materials used in silver halide printers have been widely used as digital photographic output systems because they can provide high sensitivity and high image quality. On the other hand, heat-developable color light-sensitive materials represented by pictography can be processed more easily and quickly than ordinary wet-type light-developable light-sensitive materials, and can be developed with small and compact equipment. Photothermographic materials are known in the art. For details of the photothermographic material and its process, see, for example, "Basics of Photographic Engineering", Non-Silver-Salt Photography, ed. 450062
No. 6, etc. In addition, for example, a method for forming a dye image by a coupling reaction between an oxidized form of a developing agent and a coupler is disclosed in U.S. Pat.
No. 1240 and the like. A method of forming a positive color image by a photosensitive silver dye bleaching method is disclosed in US Pat.
No. 5957.

Recently, there has been proposed a method in which a diffusible dye is released or formed in an image form by thermal development, and the diffusible dye is transferred to a dye fixing element. In this method, a negative dye image and a positive dye image can be obtained by changing the type of the dye-providing compound used or the type of the silver halide used. More specifically, U.S. Pat. Nos. 4,500,626 and 4,483,914,
03137 and 4559290, JP-A-58-14
No. 9046, JP-A-60-133449 and 59-2
Nos. 18443, 61-238056, EP-A-220746A2, JP-A-87-6199, and EP-A-210660A2. Since these photosensitive materials have high sensitivity, the time required for writing digital image data, that is, the exposure time is short. In order to take advantage of this feature, it is effective to use an array type exposure head or the like in which a plurality of exposure light sources are integrated in order to actually reduce the exposure time. Various exposure light sources have been proposed. As digital exposure light sources, light emitting diodes (LEDs), semiconductor lasers (LDs), organic
L, various phosphors and the like are used. Inexpensive LEDs and the like have been devised such that a plurality of elements are lined up for scanning exposure to reduce the exposure time. However, in the method using such a light source and using a plurality of light sources,
There is a problem that density unevenness occurs on an image due to variations between light sources. When a plurality of light sources are used, the emission wavelength and the light amount of each light source vary, so that calibration is usually performed before shipment of the product, and correction is made so that a density change does not occur. However, since the variation of each light source varies depending on the aging time and the environmental temperature during user use, a uniform image cannot be obtained depending on the user use time and use environment conditions.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a silver halide photographic emulsion for digital exposure which has a short exposure time and has no image unevenness, and a photographic material using the same.

[0005]

The object of the present invention has been attained by the following means. (1) In a characteristic curve showing a relationship between logarithmic exposure and density, three or more inflection points are within a range from logarithmic exposure at which minimum density is obtained to logarithmic exposure at which maximum density is obtained,
A photosensitive silver halide emulsion characterized in that the inclination (tan θ) of a tangent line drawn at each inflection point is alternately 3 or more and 1 or less. (2) used for digital exposure,
The photosensitive silver halide emulsion according to item (1). (3) In the characteristic curve showing the relationship between the log exposure amount and the density on the support, three or more inflections are set within a range from the log exposure amount at which the minimum density is obtained to the log exposure amount at which the maximum density is obtained. A point and the slope of the tangent drawn at each inflection point (ta
A light-sensitive material comprising at least one light-sensitive silver halide emulsion layer having the property that nθ) is alternately 3 or more and 1 or less. Here, the minimum density refers to the fog density.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A conventional light-sensitive material usually has a logarithmic exposure amount and a density called a so-called S-shaped curve or an inverted S-shaped curve comprising a minimum density, a foot portion, a straight portion, a shoulder portion, and a maximum density portion. (Revised basics of photographic engineering-silver halide photography-Corona P466). Such characteristics of the characteristic curve are designed so as to be applied not only to conventional photosensitive materials for analog exposure but also to photosensitive materials for digital exposure. However, due to the physical characteristics of the exposure light source and restrictions on the electric circuit, the dynamic range of digital exposure output for consumers is generally narrow, and as a result, photosensitive materials for digital exposure generally require high contrast. Can be Further, since the density of such a characteristic curve changes continuously, the above-described method using a plurality of light sources is disadvantageous in design. This is because density unevenness due to variations between light sources occurs on an image.
On the other hand, for printing photosensitive materials for commercial digital exposure,
As described above, it has an S-shaped curve and a super-hard characteristic curve. However, in a printing photosensitive material, since a so-called halftone dot image is exposed, the exposure amount at which the minimum density can be obtained and the exposure at which the maximum density can be obtained without using a gradation range in which the density continuously changes greatly on the characteristic curve. Exposure is performed in two values.
Therefore, even with the method using a plurality of light sources, the design is such that the density unevenness due to the variation between the light sources does not easily occur on the image. However, since exposure is performed in binary, a high-resolution light source of 2000 to 4000 dpi is required to obtain a high-quality image. For this reason, it is necessary to integrate a plurality of light sources at high density, which is extremely disadvantageous in cost.

The present invention provides a light-sensitive material that improves density unevenness due to variations between light sources without significantly increasing resolution. FIG. 1 shows a characteristic curve of a general S-shaped curve,
FIG. 2 shows an example of a characteristic curve obtained by the present invention.
A characteristic curve obtained by the present invention will be described in detail with reference to FIG.

In FIG. 2, there are five inflection points, inflection points a to e, within the range of the minimum density 0.2 and the maximum density 3.0. According to the fifth edition of the Iwanami Dictionary of Physical and Chemical Sciences, the definition of the inflection point is "when a tangent of a plane curve intersects a curve at a point of contact, that point is said." In FIG. 2, the tangents A to E correspond to the tangents. The tangent A is 3.
5, tangent B is 0.2, tangent C is 3.5, tangent D is
0.2 and the tangent E are in the order of 3.5, and are alternately 3 or more and 1 or less. For example, 0.2, 1.2, 2.0, and 3.0 indicated by thick arrows on the photosensitive material of this characteristic curve.
When exposure is performed with a digital exposure light source at the four exposure amounts, the density change can be reduced even if the four values slightly vary, such as a change in individual light source over time. This description is an example, and exposure may be performed with a ternary exposure amount, and the exposure amount is not particularly limited.
Alternatively, a photosensitive material having an inflection point having seven characteristic curves can be prepared and exposed with six exposure values.

In the present invention, the inclination of the tangent (tan θ) is alternately 3
The above and below 1 are necessary for matching with the dynamic range of the above-mentioned exposure light source. When the inclination of the tangent is 1 or less, there is no limitation, but preferably 0.2 or more. Similarly, when the inclination is 3 or more, there is no limitation, but 1
0 or less is preferable. By alternately combining a hard tone portion and a monotonous portion on the characteristic curve, the logarithmic exposure range from the minimum density to the maximum density can be narrowed, and the load on the exposure light source can be reduced and the cost can be reduced.

The exposure method of the present invention employs a method of scanning and exposing image information by emitting light from a light emitting diode, various lasers (laser diode, gas laser, etc.) via an electric signal (Japanese Patent Application Laid-Open Nos. 129625/1990 and 5/1992). −1761
Nos. 44, 5-199372, 6-127021, etc.) can be used. The image information includes an image signal obtained from a video camera, an electronic still camera, a television signal represented by the Nippon Television Signal Standard (NTSC), an image signal obtained by dividing an original image into a large number of pixels such as a scanner, CG, An image signal created using a computer represented by CAD can be used.
The exposure light source of the present invention is an LED or organic E
The use of L is particularly effective. An LED or an organic EL having an emission wavelength from the visible region to the infrared region can be used. In a color photosensitive material, three types of light sources having emission wavelength ranges corresponding to at least three different spectral sensitivities are used. The emission wavelength range is not particularly limited from the visible range to the infrared range. In order to correspond to the spectral sensitivity of ordinary color paper, blue LEDs, green LEDs, and red LEDs are used.

The method for obtaining the characteristic curve of the present invention is not particularly limited, but may be a method of preparing a plurality of halogenated emulsions having the same color sensitivity and providing a sensitivity difference between them. Alternatively, there is a method in which a plurality of layers having the same color sensitivity are formed, and a difference in sensitivity between the respective layers is provided according to a difference in developability. The photosensitive element used in the present invention basically has a photosensitive silver halide and a binder on a support, and if necessary, a dye-donating compound (in some cases, a reducing agent also serves as described later). ), And an organic metal salt oxidizing agent. These components are often added to the same layer, but may be added separately to another layer if they can react. For example, if a coloring dye-providing compound is present in the lower layer of the silver halide emulsion, the sensitivity can be prevented from lowering. The reducing agent is preferably incorporated in the photosensitive element, but may be supplied from the outside by, for example, a method of diffusing from a dye fixing element described later. Preferred in the present invention is a case where all of the blue-sensitive, green-sensitive or red-sensitive silver halide emulsion layers contain the photosensitive silver halide emulsion of the present invention.

In order to obtain a wide range of colors in the chromaticity diagram using the three primary colors of yellow, magenta and cyan, at least three silver halide emulsion layers sensitive to different spectral regions are combined. Used. In the present invention, a combination of three layers of a blue-sensitive layer, a green-sensitive layer, and a red-sensitive layer is employed. Each photosensitive layer can adopt various arrangement orders known for ordinary type color photosensitive materials. Each of these photosensitive layers may be divided into two or more layers as necessary. In particular, it is generally used. In the photosensitive layer containing the yellow dye-donating compound, a silver halide emulsion (blue-sensitive emulsion) having a spectral sensitivity in a wavelength range of 400 nm to 500 nm, and in the photosensitive layer containing the magenta dye-donating compound, 500nm
A silver halide emulsion spectrally sensitized to a range of from 600 to 600 nm (green-sensitive emulsion) is similarly applied to a photosensitive layer containing a cyan dye-donating compound. Red-sensitive emulsion). In this case, since the yellow photosensitive layer is colored yellow, it is desirable that the yellow photosensitive layer is the uppermost photosensitive layer apart from the support. That is, from the support, a combination of a cyan dye-donating compound-containing red-sensitive layer, an intermediate layer, a magenta dye-donating compound-containing green-sensitive layer, an intermediate layer, a yellow dye-donating compound-containing blue-sensitive layer, an intermediate layer, and a protective layer. is there. The cyan layer and the magenta layer have almost the same characteristics even if they are reversed. Each photosensitive layer is composed of two layers, each of which may contain a dye-donating compound and a silver halide emulsion. Alternatively, only the upper layer contains a silver halide emulsion and the lower layer contains a dye-donating compound. To increase the sensitivity.

The heat-developable color light-sensitive material can be provided with various auxiliary layers such as a protective layer, an undercoat layer, an intermediate layer, a yellow filter layer, an antihalation layer, and a back layer. When the support is polyethylene laminated paper containing a white pigment such as titanium oxide, the back layer must be designed to have an antistatic function and to have a surface resistivity of 10 ¹² Ω · cm or less. . The silver halide emulsion of the present invention may be any of silver chloride, silver bromide, silver iodobromide, silver chlorobromide, silver chloroiodide, and silver chloroiodobromide. The silver halide emulsion may be a surface latent image type emulsion or an internal latent image type emulsion. The internal latent image type emulsion is used as a direct reversal emulsion in combination with a nucleating agent or light fogging. Further, a so-called core-shell emulsion in which the inside of the grain and the surface layer of the grain have different phases may be used, and silver halides having different compositions may be joined by epitaxial joining. The silver halide emulsion may be monodispersed or polydispersed.
As described in JP-A-167743 and JP-A-4-223463, a method of mixing monodisperse emulsions and adjusting gradation is preferably used. The particle size is 0.1-2 μm, especially 0.2-
1.5 μm is preferred. The crystal habits of silver halide grains include those having regular crystals such as cubic, octahedral, and tetrahedral, those having irregular crystal systems such as spheroids and high aspect ratio tabular, and those having twin planes. Those having such twin defects, composites thereof, or any other materials may be used.

Specifically, US Pat. No. 4,500,62
No. 6, Column 50, No. 4,628,021, Research Disclosure Magazine (hereinafter abbreviated as RD) No. 17,
029 (1978), No. 17, 643 (1978)
No. 18, 716 (197)
Nov. 1997), p. 648, No. 307, 105 (19
Nov. 89, pp. 863-865, JP-A-62-253.
No. 159, 64-13546, JP-A-2-2365
No. 46, No. 3-110555, and "Physics and Chemistry of Photography" by Grafkid, published by Paul Montel (P. Glafki)
des, Chemie et Phisique Photographique, Paul Monte
l, 1967), "Photographic Emulsion Chemistry" by Duffin, published by Focal Press (GFDuffin, Photographic Emulsion C)
hemistry, Focal Press, 1966), "Manufacture and Coating of Photographic Emulsions", by Zerikman et al.
L. Zelikman et al., Making and Coating Photographic
Emulsion, Focal Press, 1964), etc., any of which can be used.

Hereinafter, the present invention is applied to the heat-developable color light-sensitive material of the present invention.
All silver halide grains described are described. Book
In the process of preparing the photosensitive silver halide emulsion of the invention, excess
It is preferable to perform so-called desalting for removing the salt of the above. This
As a means for gelling gelatin
Dell washing method may be used, and it consists of polyvalent anions
Inorganic salts (eg, sodium sulfate), anionic surfactant
Surfactant, anionic polymer (for example, polystyrene sulfo
Sodium salts) or gelatin derivatives (eg, fats
Fatty acylated gelatin, aromatic acylated gelatin, aromatic
Sedimentation method using carbamoylated gelatin)
May be. The sedimentation method is preferably used. Used in the present invention
The photosensitive silver halide emulsion used for various purposes
, Rhodium, platinum, cadmium, zinc, thallium,
Heavy metals such as lead, iron and osmium may be contained.
These compounds may be used alone or in combination of two or more.
They may be used in combination. The amount added depends on the purpose of use.
As a rule, generally 10 mol / mol of silver halide is used.^-9~
10^-3It is about a mole. In addition, when including
It may be evenly distributed and may be localized inside or on the surface of the particles.
You may let it. Specifically, JP-A-2-236542,
No. 1-116637, 5-181246, etc.
Is preferably used. Halogen used in the present invention
The preferred amount of iridium added to the silver halide emulsion is
10 per mole of silver genide^-9-10^-FourMole and more
Preferably 10^-8-10^-6Is a mole. Core shell emulsion
If, add iridium to the core and / or shell
May be added. As the compound, K_TwoIrCl₆And K_ThreeI
rCl₆Is preferably used. Also used in the present invention
Preferred amount of rhodium added to silver halide emulsion
Is 10 per mole of silver halide^-9-10^-6In mole
You. Further, iron to the silver halide emulsion used in the present invention.
Is preferably 10 per mole of silver halide.^-7
-10^-3Mole, more preferably 10^-6-10 ^-3Mo
It is.

A part or all of these heavy metals is doped in advance in a fine grain emulsion such as silver chloride, silver chlorobromide, silver bromide, silver iodobromide and the like, and then the fine grain emulsion is added to obtain a silver halide. A method of locally doping the emulsion surface is also preferably used. In the step of forming the grains of the photosensitive silver halide emulsion of the present invention, as a silver halide solvent, a rhodan salt, ammonia, a 4-substituted thioether compound or an organic thioether derivative described in JP-B-47-11386 or JP-A-53-144319 is used. The sulfur-containing compounds described can be used. For other conditions, see Grafkide, "Physics and Chemistry of Photography,"
Published by Paul Montell (P. Glafkides, Chemie et Phisiqu
e Photographique, Paul Montel, 1697), "Photographic Emulsion Chemistry" by Duffin, published by Focal Press (GFDuff
in, Photographic Emulsion Chemistry, Focal Press,
1966), "Production and Coating of Photographic Emulsion" by Zelikman et al., Published by Focal Press (VLZelikman et al., Ma.
king and Coating Photographic Emulsion, Focal Pres
s, 1964). That is, any of an acidic method, a neutral method, and an ammonia method 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, and a combination thereof. In order to obtain a monodisperse emulsion, a simultaneous mixing method is preferably used. An inverse mixing method in which grains are formed in the presence of excess silver ions can also be used. As one type of the double jet method, a so-called controlled double jet method in which the pAg in a liquid phase in which silver halide is formed is kept constant can be used. Further, in order to accelerate the grain growth, the addition concentration, the addition amount and the addition speed of the silver salt and the halogen salt to be added may be increased (Japanese Patent Application Laid-Open No. 55-155).
-142329, 55-158124, U.S. Patent No. 3,650,757). Further, the stirring method of the reaction solution may be any known stirring method. The temperature and pH of the reaction solution during the formation of silver halide grains may be set in any manner depending on the purpose. The preferred pH range is 2.2.
-8.5, more preferably 2.5-7.5. The coating amount of the photosensitive silver halide emulsion used in the present invention is in the range of 1 mg to 10 g / m ² in terms of silver.

In order to impart blue-sensitive, green-sensitive, and red-sensitive color sensitivity to the photosensitive silver halide used in the present invention,
The photosensitive silver halide emulsion is spectrally sensitized with methine dyes and the like. If necessary, the infrared sensitivity may be subjected to spectral sensitization. In particular, the silver halide emulsion containing gold of the present invention is preferably spectrally sensitized to red sensitivity. The dyes used include cyanine dyes, merocyanine dyes,
Complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes are included. Specifically, U.S. Pat. No. 4,617,257, and JP-A-59-1805.
No. 50, No. 64-13546, JP-A-5-45828
And sensitizing dyes described in JP-A-5-45834. These sensitizing dyes may be used alone, or a combination thereof may be used. The combination of sensitizing dyes is often used for the purpose of adjusting the wavelength of supersensitization or spectral sensitization. . The number of sensitizing dyes in the combination is preferably two or more and less than five. Along with the sensitizing dye, a dye which does not itself have a spectral sensitizing effect or a compound which does not substantially absorb visible light and exhibits supersensitization may be contained in the emulsion (for example, US Pat. 615, 641, and JP-A-63-23145). These sensitizing dyes may be added to the emulsion at or before chemical ripening, or before or after nucleation of silver halide grains according to U.S. Pat. Nos. 4,183,756 and 4,225,666. Good. These sensitizing dyes and supersensitizers may be added as a solution of an organic solvent such as methanol, a dispersion of gelatin or the like, or a solution of a surfactant. The addition amount is generally from 10 ^-8 to 10 per mol of silver halide.
^-2 moles.

The additives used in such a process and the known photographic additives which can be used in the photothermographic material and the dye fixing material of the present invention are described in RD Nos. 17, 643 and N.
o.18, 716 and Nos. 307, 105, and the relevant portions are summarized in the following table. Type of additive RD17643 RD18716 RD307105 1. Chemical sensitizer page 23, page 648, right column, page 866 2. Sensitivity enhancer, page 648, right column 3. Spectral sensitizer, page 23-24, page 648, right column, pages 866-868 Color sensitizer ~ page 649 right column 4. Fluorescent brightener 24 page 648 page right column 868 5. Fog prevention 24 ~ 25 page 649 right column 868 ~ 870 agent, stabilizer 6. 26Page 26 649 Right column Page 873 Filter 左 Page 650 Left column Dye, UV absorber 7.Dye image 25 650 Page Left column 872 Stabilizer 8.Hardening agent 26 Page 651 Left column 874-875 9. Binder page 26 page 651 left column 873-874 10. plasticizer, page 27 650 page right column 876 lubricant 11. Coating aid, page 26-27 page 650 right column 875-876 surfactant 12 Static page 27 page 650 right column pages 876-877 Inhibitor 13. Matting agent pages 878-879

As the binder for the constituent layers of the photothermographic material and the dye fixing material, hydrophilic binders are preferably used. Examples thereof include those described in the aforementioned Research Disclosure and JP-A-64-13546, pages (71) to (75). Specifically, a transparent or translucent hydrophilic binder is preferable, for example, gelatin,
Examples include natural compounds such as proteins such as gelatin derivatives or cellulose derivatives, polysaccharides such as starch, gum arabic, dextran and pullulan, and synthetic high molecular compounds such as polyvinyl alcohol, polyvinylpyrrolidone and acrylamide polymers. No. 4,960,6.
81 No., superabsorbent polymers described in JP-A-62-245260, i.e. -COOM or -SO ₃ M (M
Is a homopolymer of a vinyl monomer having a hydrogen atom or an alkali metal, or a copolymer of the vinyl monomers with each other or with another vinyl monomer (eg, sodium methacrylate, ammonium methacrylate, a product manufactured by Sumitomo Chemical Co., Ltd.) The name Sumikagel L-5H) is also used. These binders can be used in combination of two or more kinds. Particularly, a combination of gelatin and the above binder is preferable. The gelatin may be selected from lime-processed gelatin, acid-processed gelatin, and so-called demineralized gelatin having a reduced content of calcium and the like according to various purposes, and it is also preferable to use them in combination. When a system for performing thermal development by supplying a small amount of water is used, it is possible to quickly absorb water by using the above superabsorbent polymer. Further, when the superabsorbent polymer is used for the dye fixing layer or its protective layer, it is possible to prevent the dye from being re-transferred from the dye fixing element to another after transfer. In the present invention, the coating amount of the binder is preferably 20 g or less, more preferably 10 g or less, and even more preferably 7 g / m ^2.
g to 0.5 g is appropriate.

In the present invention, an organic metal salt can be used as an oxidizing agent together with the photosensitive silver halide emulsion. Among such organic metal salts, an organic silver salt is particularly preferably used. Organic compounds that can be used to form the above-described organic silver salt oxidizing agents include US Pat.
There are benzotriazoles, fatty acids and other compounds described in 00,626, columns 52 to 53 and the like. The acetylene silver described in U.S. Pat. No. 4,775,613 is also useful. Two or more organic silver salts may be used in combination. The above-mentioned organic silver salt is used in an amount of 0.01 per mole of photosensitive silver halide.
10 to 10 mol, preferably 0.01 to 1 mol, can be used in combination. Total coating amount of light-sensitive silver halide emulsion and the organic silver salt is 0.05 to 10 g / m ² in terms of silver, and preferably from 0.1-4 g / m ^2.

As the reducing agent used in the present invention, those known in the field of photothermographic materials can be used. Further, a dye-providing compound having a reducing property described later is also included (in this case, another reducing agent may be used in combination). Further, a reducing agent precursor which does not itself have a reducing property but expresses a reducing property by the action of a nucleophilic reagent or heat during the development process can be used. U.S. Pat. No. 4,500,626 is an example of a reducing agent used in the present invention.
Nos. 49-50, 4, 839, 272, 4,
330,617, 4,590,152, 5,0
17,454,5,139,919, JP-A-60
No. 140335, pages (17) to (18), and 57-
No. 40245, No. 56-138736, No. 59-17
No. 8458, No. 59-53831, No. 59-1824
No. 49, No. 59-182450, No. 60-11955
No. 5, 60-128436, 60-128439
No. 60-198540, No. 60-181742
No. 61-259253, No. 62-201434
No. 62-244444 and No. 62-131253
No. 62-131256, No. 63-10151,
Nos. 64-13546, pp. (40)-(57), JP-A-1-120553, JP-A-2-32338, JP-A-2-3.
No. 5451, No. 2-234158, No. 3-16044
3, reducing agents and reducing agent precursors described in EP 220,746 at pages 78 to 96 and the like. Various combinations of reducing agents, such as those disclosed in U.S. Pat. No. 3,039,869, can also be used.

When a diffusion-resistant reducing agent is used, an electron transfer agent and / or an electron transfer agent may be used, if necessary, to promote electron transfer between the diffusion-resistant reducing agent and the developable silver halide.
Alternatively, an electron transfer agent precursor can be used in combination. Particularly preferably, said US Patent No. 5,139,
919, European Patent Publication No. 418,743,
Nos. 138556 and 3-102345 are used. JP-A-2-230143, JP-A-2-230143;
A method of stably introducing the compound into the layer as described in JP-A-35044 is preferably used. The electron transfer agent or its precursor can be selected from the above-mentioned reducing agents or its precursors. It is desirable that the mobility of the electron transfer agent or its precursor is higher than that of the diffusion-resistant reducing agent (electron donor). Particularly useful electron transfer agents are 1-phenyl-3-pyrazolidones or aminophenols. The diffusion-resistant reducing agent (electron donor) to be used in combination with the electron transfer agent may be any one which does not substantially move in the layer of the light-sensitive material among the aforementioned reducing agents, and is preferably a hydroquinone, Sulfonamidophenols, sulfonamidonaphthols, JP-A-53-110827
No. 5,032,487, U.S. Pat.
Compounds described as electron donors in JP-A Nos. 634 and 4,839,272 and dye-donating compounds having a diffusion-reducing and reducing property described below are mentioned.

An electron donor precursor as described in JP-A-3-160443 is also preferably used. Furthermore, color mixture prevention, color reproduction improvement, white background improvement,
The above reducing agent can be used for various purposes such as preventing silver transfer to the dye fixing material. Specifically, European Patent Publication Nos. 524,649 and 357,040, and JP-A-4-24-2
49245, 2-64633, 2-46450
And the reducing agents described in JP-A-63-186240 are preferably used. Japanese Patent Publication No. Hei 3-63733,
-150135, 2-110557, 2-64
634, 3-43735, European Patent Publication No. 45
A development inhibitor releasing reducing compound as described in 1,833 is also used. In the present invention, the total amount of the reducing agent is from 0.01 to 20 mol, particularly preferably from 0.1 to 10 mol, per mol of silver.

In the present invention, a compound that releases a diffusible dye in response to this reaction when silver ions are reduced to silver under a high temperature condition, that is, a dye-donating compound is used. Examples of the dye donating compound include a compound having a function of releasing an imagewise diffusible dye.
This type of compound can be represented by the following general formula [LI]. ((Dye) mY) nZ [LI] Dye represents a dye group or a dye precursor group, a temporarily shortened dye group or a dye precursor group, and Y represents a simple bond or a linking group. Z represents a difference in diffusivity of the compound represented by ((Dye) m-Y) nZ corresponding to a photosensitive silver salt having an image-like latent image, or
(Dye) m- is released and the released (Dye) m-
Y and ((Dye) m-Y) n-Z represent a group having a property that causes a difference in diffusivity, m represents an integer of 1 to 5, and n represents 1 or 2. , M, n
When either is not 1, a plurality of Dyes may be the same or different. More specifically, they are the following compounds.

A coupler having a diffusible dye as a leaving group, which is a non-diffusible compound (DDR coupler) which releases a diffusible dye by reacting with an oxidized form of a reducing agent. Specifically, British Patent No. 1,330,524, Japanese Patent Publication No. Sho 4
8-39165, U.S. Patent No. 3,443,940,
Nos. 4,474,867 and 4,483,914. Is reducible to silver halides or organic silver salts,
A non-diffusible compound (DRR compound) that releases a diffusible dye when its partner is reduced. Representative examples are U.S. Pat. Nos. 3,928,312 and 4,053,312,
Nos. 4,055,428 and 4,336,322, JP-A-56-65839, JP-A-59-69839, and JP-A-5-6939
No. 3-3819, No. 51-104343, RD17,
465, U.S. Pat. Nos. 3,725,062 and 3,7
Nos. 28,113 and 3,443,939;
No. 116537, No. 57-179840 and U.S. Pat. No. 4,500,626. Specific examples of the DRR compound include the aforementioned US Pat. No. 4,500,6.
Compounds described in Columns 22 to 44 of No. 26 can be mentioned, and among them, the compounds described in the aforementioned U.S. Pat.
(1)-(3), (10)-(13), (16)-(19), (28)-(30), (33)
To (35), (38) to (40), and (42) to (64) are preferred. The compounds described in U.S. Pat. No. 4,639,408, columns 37 to 39 are also useful. In addition, as the above-mentioned couplers and dye-donating compounds other than the general formula [LI], dye silver compounds in which an organic silver salt is combined with a dye (Research Disclosure Magazine, May 1978, pages 54 to 58, etc.) Azo dyes (US Pat. No. 4,235,957, Research Disclosure, April 1976, pp. 30-32, etc.) and leuco dyes (US Pat. No. 3,985) , 565,4,022,6
No. 17, etc.) can also be used. In the present invention, this DR
R compounds are preferably used.

Hydrophobic additives such as a dye-donating compound and a diffusion-resistant reducing agent can be introduced into a layer of a photothermographic material by a known method such as the method described in US Pat. No. 2,322,027. it can. In this case, US Pat.
Nos. 55,470, 4,536,466, 4,53
6,467, 4,587,206, 4,55
5,476, 4,599,296, 3-6
A high-boiling organic solvent as described in No. 2256 or the like can be used together with a low-boiling organic solvent having a boiling point of 50 ° C to 160 ° C as necessary. Two or more of these dye-donating compounds, nondiffusible reducing agents, high-boiling organic solvents, and the like can be used in combination. The amount of the high boiling organic solvent is 10 g or less, preferably 5 g or less, more preferably 1 g to 0.1 g, per 1 g of the dye-donating compound used. Also, 1 ml or less per 1 g of the binder, and further 0.5
It is suitable to be less than 0.3 ml, especially less than 0.3 ml. Also, a dispersion method using a polymer described in JP-B-51-39853 and JP-A-51-59943 and JP-A-62-30 are disclosed.
No. 242 or the like and a method of adding it in the form of a fine particle dispersion can also be used. In the case of a compound which is substantially insoluble in water, it can be dispersed and contained as fine particles in a binder in addition to the above method. When dispersing the hydrophobic compound in the hydrophilic colloid, various surfactants can be used. For example, Japanese Patent Application Laid-Open No.
The surfactants described in Research Disclosure, pages 7 to 38, mentioned above, can be used. In the photothermographic material of the present invention, a compound which activates development and stabilizes an image at the same time can be used. Specific compounds preferably used are described in U.S. Pat. No. 4,500,626, columns 51 to 52. In a system for forming an image by diffusion transfer of a dye, various compounds are used for the purpose of immobilizing or decolorizing unnecessary dyes and coloring matters in the constituent layers of the photothermographic material of the present invention and improving the white background of the obtained image. Can be added. Specifically, EP-A-353,741 and EP-A-461,416, JP-A-63-163345 and JP-A-63-163345,
The compound described in 2-203158 can be used.

Various pigments and dyes can be used for the constituent layers of the photothermographic material of the present invention for the purpose of improving color separation and increasing sensitivity. Specifically, the compounds described in Research Disclosure and EP-A-479,1 are disclosed.
No. 67, No. 502,508, JP-A-1-1677838
Nos. 4-343355 and 2-168252, JP-A-61-20943, and EP-A-479,16.
Nos. 7, 502, 508 and the like can be used. In a system for forming an image by diffusion transfer of a dye, a dye fixing material is used together with the photothermographic material. The dye-fixing material may be in the form of being separately coated on a support separate from the photosensitive material, or may be in the form of being coated on the same support as the photosensitive material. The relationship between the photosensitive material and the dye-fixing material, the relationship with the support, and the relationship with the white reflective layer described in column 57 of US Pat. No. 4,500,626 can be applied to the present invention. The dye fixing material preferably used in the present invention has at least one layer containing a mordant and a binder. As the mordant, those known in the field of photography can be used. Specific examples thereof are U.S. Pat. No. 4,500,626, columns 58 to 59, and JP-A-61-88256, pages (32) to (41). And mordants described in JP-A-1-161236, pages (4) to (7), U.S. Patent Nos. 4,774,162 and 4,619,
No. 883, No. 4,594,308 and the like. No. 4,463,073.
A dye-receiving polymer compound as described in No. 9 may be used. The binder used in the dye fixing material of the present invention is preferably the above-mentioned hydrophilic binder. Further, it is preferable to use a combination of carrageenans as described in EP-A-443,529 and a latex having a glass transition temperature of 40 ° C. or lower as described in JP-B-3-74820. Auxiliary layers such as a protective layer, a release layer, an undercoat layer, an intermediate layer, a back layer, and an anti-curl layer can be provided on the dye fixing material as needed. It is particularly useful to provide a protective layer.

In the constituent layers of the photothermographic material and the dye-fixing material, a high-boiling organic solvent can be used as a plasticizer, a slipper or an agent for improving the releasability between the photosensitive material and the dye-fixing material. Specifically, there are those described in Research Disclosure and JP-A-62-245253. Further, for the above purpose, various silicone oils (all silicone oils from dimethyl silicone oil to modified silicone oil obtained by introducing various organic groups into dimethyl siloxane) can be used. As examples thereof, various modified silicone oils, particularly carboxy-modified silicone (trade name: X-22-3710) described in “Modified Silicone Oil” Technical Documents P6 to 18B issued by Shin-Etsu Silicone Co., Ltd. are effective. Also, silicone oils described in JP-A Nos. 62-215953 and 63-46449 are effective.

An anti-fading agent may be used in the photothermographic material or the dye fixing material. Examples of the anti-fading agent include antioxidants, ultraviolet absorbers, and certain metal complexes, and dye image stabilizers and ultraviolet absorbers described in Research Disclosure are also useful. As antioxidants, for example, chroman compounds, coumaran compounds,
There are phenol compounds (for example, hindered phenols), hydroquinone derivatives, hindered amine derivatives, and spiroindane compounds. Also, Japanese Unexamined Patent Publication No.
The compound described in -159644 is also effective. Examples of ultraviolet absorbers include benzotriazole-based compounds (such as U.S. Pat. No. 3,533,794), 4-thiazolidone-based compounds (such as U.S. Pat. No. 3,352,681), and benzophenone-based compounds (Japanese Unexamined Patent Publication No. 2784) and JP-A Nos. 54-48535 and 62-136641.
And the compounds described in JP-A-61-88256. Further, ultraviolet absorbing polymers described in JP-A-62-260152 are also effective. As metal complexes, U.S. Pat. Nos. 4,241,155 and 4,245,018 Nos. 3 to
Column 36, column 4, 254, 195 columns 3 to 8, JP-A-62-174741, JP-A-61-88256 (27)
To (29), JP-A-63-199248, JP-A-1-7
5568 and 1-74272.

An anti-fading agent for preventing fading of the dye transferred to the dye-fixing material may be contained in the dye-fixing material in advance, or the dye may be supplied from an external source such as a photothermographic material or a transfer solvent described later. It may be supplied to the fixing material. The above antioxidants, ultraviolet absorbers, and metal complexes may be used in combination with each other. A fluorescent whitening agent may be used in the photothermographic material or the dye fixing material. In particular, it is preferable to incorporate a fluorescent whitening agent into the dye-fixing material or to supply it from outside such as a photothermographic material or a transfer solvent.
For example, K. Veenkataraman ed., “The Chemistryo
f Synthetic Dyes ", Vol. V, Chapter 8, JP-A-61-14
No. 3,752, for example. More specifically, a stilbene compound, a coumarin compound, a biphenyl compound, a benzoxazolyl compound, a naphthalimide compound, a pyrazoline compound, a carbostyril compound, and the like can be given. The fluorescent whitening agent can be used in combination with a fading inhibitor or an ultraviolet absorber. Specific examples of these anti-fading agents, ultraviolet absorbers and fluorescent whitening agents are described in JP-A-62-215272 (1).
25) to (137), JP-A-1-161236 (1)
7) to (43).

Examples of the hardening agent used for the constituent layers of the photothermographic material and the dye fixing material include the above-mentioned Research Disclosure, US Pat. No. 4,678,739, column 41, 4,791,042, No. 59-116655,
Hardening agents described in JP-A-62-245261, JP-A-61-18942, and JP-A-4-218044 are exemplified.
More specifically, aldehyde hardeners (such as formaldehyde), aziridine hardeners, epoxy hardeners, and vinyl sulfone hardeners (N, N'-ethylene-bis (vinylsulfonylacetamide)) Ethane), an N-methylol hardener (such as dimethylol urea), or a polymer hardener (compounds described in JP-A-62-234157). These hardeners are used in an amount of 0.001-1 g, preferably 0.1 g / g of gelatin applied.
005 to 0.5 g are used. The layer to be added may be any of the constituent layers of the light-sensitive material and the dye-fixing material, or may be added in two or more layers. Various antifoggants or photographic stabilizers and precursors thereof can be used in the constituent layers of the photothermographic material and the dye fixing material. Specific examples include the research
Disclosure, U.S. Pat. No. 5,089,378
Nos. 4,500,627 and 4,614,702
Nos., JP-A-62-13546, pages (7) to (9), (5)
7) to (71) and (81) to (97), U.S. Patent Nos. 4,775,610 and 4,626,500,
No. 4,983,494, JP-A-62-174747.
No. 62-239148, No. 63-264747
No., JP-A-1-150135 and 2-110557
No. 2-178650, RD 17, 643 (197
8 years) (24)-(25). The amount of these compounds used is 5 × 1 per mole of silver.
It is preferably from 0 ^-6 to 1 × 10 ^-1 mol, and more preferably from 1 × 10 ^-5 to
1 × 10 ^-2 mol is preferably used.

In the constituent layers of the photothermographic material and the dye fixing material, coating aids, improved releasability, improved slipperiness, antistatic,
Various surfactants can be used for the purpose of accelerating development and the like. Specific examples of the surfactant are described in Research Disclosure, JP-A-62-173463, and 62-1.
No. 83457 and the like. The constituent layers of the photothermographic material and the dye fixing material may contain an organic fluoro compound for the purpose of improving slipperiness, preventing static charge, and improving releasability. Representative examples of organic fluoro compounds include Japanese Patent Publication No. 57
No. 9053, columns 8 to 17, JP-A-61-20944
No. 62-135826 and hydrophobic fluorine compounds such as oily fluorine compounds such as fluorine oil or solid fluorine compound resins such as ethylene tetrafluoride resin. Can be

A matting agent can be used in the photothermographic material and the dye fixing material for the purpose of preventing adhesion, improving slipperiness, and making the surface non-glossy. Examples of the matting agent include compounds described on page 29 of JP-A-61-88256 such as silicon dioxide, polyolefin and polymethacrylate, and JP-A 63-2747 such as benzoguanamine resin beads, polycarbonate resin beads and AS resin beads.
Nos. 44 and 63-274952.
In addition, the compounds described in the aforementioned Research Disclosure can be used. These matting agents are the top layer (protective layer)
In addition, it can be added to the lower layer as needed.
In addition, the constituent layers of the photothermographic material and the dye fixing material may contain a thermal solvent, an antifoaming agent, a germicide / antibacterial agent, colloidal silica, and the like. Specific examples of these additives are described in JP-A-61-88256, pages (26) to (32),
No. 11338 and Japanese Patent Publication No. 2-51496.

In the present invention, an image formation accelerator can be used in the photothermographic material and / or the dye fixing material. Examples of the image formation accelerator include a redox reaction between a silver salt oxidizing agent and a reducing agent, promotion of a reaction such as formation of a dye from a dye-providing substance or decomposition of the dye or release of a diffusible dye, and photothermographic exposure. It has the function of promoting the transfer of the dye from the material layer to the dye fixing layer, and from the physicochemical function, a base or base precursor, a nucleophilic compound, a high-boiling organic solvent (oil), a thermal solvent, a surfactant , Silver, or compounds that interact with silver ions. However, these substance groups generally have a composite function and usually have some of the above-mentioned promoting effects. Details of these are described in U.S. Pat. No. 4,678,739, columns 38-40. As base precursors, salts of organic acids and bases that decarboxylate by heat, intramolecular nucleophilic substitution,
There are compounds that release amines by Rossen rearrangement or Beckmann rearrangement. An example is U.S. Pat.
Nos. 514,493 and 4,657,848.

In a system in which thermal development and transfer of a dye are carried out simultaneously in the presence of a small amount of water, a method in which a base and / or a base precursor is contained in a dye-fixing material is preferable from the viewpoint of improving the storage stability of the photothermographic material. . In addition to the above,
EP 210,660, U.S. Pat. No. 4,74
No. 0,445, and combinations of compounds which are capable of forming a complex with metal ions constituting the hardly soluble metal compound (referred to as complex forming compounds), and JP-A-61-232451. A compound that generates a base by electrolysis as described above can also be used as a base precursor. In particular, the former method is effective. The sparingly soluble metal compound and the complex forming compound are advantageously added separately to the photothermographic material and the dye-fixing element, as described in the aforementioned patent.

In the present invention, various development terminating agents can be used in the photothermographic material and / or the dye-fixing material in order to always obtain a constant image with respect to fluctuations in processing temperature and processing time during development. . The term "development terminator" as used herein means that after appropriate development, the base is quickly neutralized or reacts with the base to reduce the base concentration in the film, and interact with a compound that stops development or silver and silver salts to suppress development. Compound. Specific examples include an acid precursor that releases an acid when heated, an electrophilic compound that causes a substitution reaction with a coexisting base when heated, or a nitrogen-containing heterocyclic compound, a mercapto compound, and a precursor thereof. For more details, see
2-253159 (31)-(32).

In the present invention, as a support for the photothermographic material or the dye fixing material, a support that can withstand the processing temperature is used. In general, papers and synthetic polymers (films) described in pages 223 to 240 of Coronation Co., Ltd. (1979), "Basics of photographic engineering-silver halide photography-" edited by The Photographic Society of Japan. And photographic supports. Specifically, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyvinyl chloride, polystyrene, polypropylene, polyimide, celluloses (for example, triacetyl cellulose) or those containing pigments such as titanium oxide in these films, and further, Film-processed synthetic paper made from polypropylene, etc., mixed paper made from synthetic resin pulp such as polyethylene and natural pulp, Yankee paper, baryta paper, coated paper (especially cast-coated paper), metal, cloth, glass, etc. Is used. These can be used alone or as a support laminated on one or both sides with a synthetic polymer such as polyethylene. The laminate layer may contain pigments and dyes such as titanium oxide, ultramarine blue, and carbon black as necessary. In addition, JP-A-62-253159 (pages 29 to 31) and JP-A-1-161236 (1)
The supports described in pages 4) to (17), JP-A-63-316848, JP-A-2-22651, JP-A-3-56955, and U.S. Pat. No. 5,001,033 can be used. The back surface of these supports may be coated with a hydrophilic binder, a semiconductive metal oxide such as alumina sol or tin oxide, carbon black, or another antistatic agent.
Specifically, a support described in JP-A-63-220246 can be used. The surface of the support is preferably subjected to various surface treatments or undercoating for the purpose of improving the adhesion to the hydrophilic binder.

The photothermographic material and / or dye-fixing material of the present invention may have a form having a conductive heating layer as a heating means for heat development and diffusion transfer of dye. The heat generating element in this case is described in JP-A-61-145.
No. 544 can be used. The heating temperature in the thermal development step is about 50 ° C. to 250 ° C., and especially about 60 ° C.
C. to 180 C. is useful. The dye diffusion transfer step may be performed simultaneously with the heat development, or may be performed after the heat development step. In the latter case, the transfer temperature can be in the range of from the temperature in the heat development step to room temperature, but it is particularly preferably 50 ° C. or higher and about 10 ° C. lower than the temperature in the heat development step.

Although the movement of the dye is caused only by heat,
Solvents may be used to promote dye transfer. Also,
U.S. Pat. Nos. 4,704,345 and 4,740,44
No. 5, JP-A-61-238056, etc., a method in which development and transfer are carried out simultaneously or continuously by heating in the presence of a small amount of a solvent (particularly water) is also useful. In this method, the heating temperature is preferably 50 ° C. or higher and the boiling point of the solvent or lower. For example, when the solvent is water, the temperature is preferably 50 ° C. to 100 ° C. Examples of the solvent used for accelerating the development and / or for diffusing and transferring the dye include water, a basic aqueous solution containing an inorganic alkali metal salt and an organic base (these bases are described in the section of the image formation accelerator). Described are used), a low-boiling solvent or a mixed solution of a low-boiling solvent and water or the basic aqueous solution. Further, a surfactant, an antifoggant, a compound forming a complex with a hardly soluble metal salt, a fungicide, and a bactericide may be contained in the solvent. Water is preferably used as a solvent used in these steps of thermal development and diffusion transfer, and any water may be used as long as it is generally used. Specifically, distilled water, tap water, well water, mineral water and the like can be used. Further, in the heat developing apparatus using the photothermographic material and the dye fixing material of the present invention, water may be used up or circulated and used repeatedly. In the latter case, water containing components eluted from the material will be used. JP-A-63-144354 and JP-A-63-144355,
The apparatus and water described in JP-A-62-38460 and JP-A-3-210555 may be used.

These solvents can be applied to the photothermographic material, the dye fixing material or both. The amount used may be not more than the mass of the solvent corresponding to the maximum swelling volume of the entire coating film. As a method of applying this water,
For example, JP-A-62-253159, p. 5;
The method described in 3-85544 or the like is preferably used. Further, the solvent can be used by being encapsulated in a microcapsule or incorporated in advance in the photothermographic material and / or dye fixing element in the form of a hydrate. The temperature of the water to be applied may be 30 ° C. to 60 ° C. as described in JP-A-63-85544. In particular, it is useful to raise the temperature to 45 ° C. or higher for the purpose of preventing the propagation of various bacteria in water.

In order to promote the dye transfer, a system in which a hydrophilic thermal solvent which is solid at room temperature and dissolves at a high temperature is incorporated in the photothermographic material and / or the dye fixing material can be adopted. The layer to be incorporated may be any of a light-sensitive silver halide emulsion layer, an intermediate layer, a protective layer, and a dye fixing layer, but is preferably a dye fixing layer and / or an adjacent layer. Examples of hydrophilic thermal solvents include ureas, pyridines, amides, sulfonamides, imides, alcohols, oximes, and other heterocycles.

As a heating method in the development and / or transfer step, a heating block, a plate, a hot plate, a hot presser, a heat roller, a heat drum, a halogen lamp heater, an infrared and far infrared lamp heater are used. For example, or by passing through a high-temperature atmosphere. The method described in JP-A-62-253159 and JP-A-61-147244 (page 27) can be applied to the method of superposing the photothermographic material and the dye fixing material.

[0043]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Examples How to make a photosensitive silver halide emulsion Photosensitive silver halide emulsion (1) [for red-sensitive emulsion layer] A well-stirred gelatin aqueous solution (800 g of gelatin, 12 g of potassium bromide in 26.3 liters of water, chloride 80 g of sodium and 1.2 g of compound (a) were added to obtain 53
C), and add the solution (I) shown in Table 1 at an equal flow rate for 9 minutes, and add the solution (II) 9 seconds before the addition of the solution (I).
Added at an equal flow rate for 10 minutes. After 36 minutes, (I) in Table 1
Solution II) was added at a constant flow rate for 24 minutes, and solution (IV) was added at the same flow rate as solution (III) for 25 minutes. After washing with water and desalting by a conventional method, 880 g of lime-treated ossein gelatin and compound (b)
The pH was adjusted to 6.0 by adding 2.8 g, and 12.8 g of ribonucleic acid decomposed product and 32 mg of trimethylthiourea were added to add 60 g.
After optimal chemical sensitization at 71 ° C for 71 minutes, 4-hydroxy-6
-Methyl-1,3,3a, 7-tetrazaindene 2.6
g, 3.2 g of the dye (a), 5.1 g of KBr, and 2.6 g of a stabilizer described later were sequentially added, followed by cooling. Thus, 28.1 kg of a monodisperse cubic silver chlorobromide emulsion having an average grain size of 0.35 μm was obtained.

Photosensitive silver halide emulsion (1-2) [for red-sensitive emulsion layer] A well-stirred aqueous gelatin solution (800 g of gelatin, 10 g of potassium bromide, 70 g of sodium chloride and compound (26.3 liters of water) a) Add 1.1 g and add 46
Solution (I) shown in Table 1 was added at an equal flow rate for 12 minutes, and the solution (II) was added at an equal flow rate for 12 minutes and 10 seconds from 10 seconds before the addition of the solution (I). . Table 1 after 36 minutes
Solution (III) was added at a constant flow rate for 24 minutes, and Solution (IV) was added at the same flow rate as the solution (III) for 25 minutes. After washing with water and desalting in a conventional manner, 880 g of lime-treated ossein gelatin and 2.8 g of compound (b) were added to adjust the pH to 6.0, and 9.8 g of ribonucleic acid degradation product and 32 mg of trimethylthiourea were added. After optimal chemical sensitization at 60 ° C. for 71 minutes, 1.8 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene, 2.3 g of dye (a), 5.1 g of KBr, After sequentially adding 2.6 g of a stabilizer described below, the mixture was cooled. Thus, 28.1 kg of a monodispersed cubic silver chlorobromide emulsion having an average grain size of 0.25 μm was obtained.

Photosensitive silver halide emulsion (1-3) [for red-sensitive emulsion layer] A well-stirred aqueous gelatin solution (800 g of gelatin, 12 g of potassium bromide, 90 g of sodium chloride and 2 g of compound (26.3 liters of water) a) Add 1.2 g and add 57
) Was added at an equal flow rate for 10 minutes, and the solution (II) was added at an equal flow rate for 10 minutes and 10 seconds from 10 seconds before the addition of the solution (I). . Table 1 after 36 minutes
Solution (III) was added at a constant flow rate for 24 minutes, and Solution (IV) was added at the same flow rate as the solution (III) for 25 minutes. After washing with water and desalting in a conventional manner, 880 g of lime-treated ossein gelatin and 2.8 g of compound (b) were added to adjust the pH to 6.0, and 10.3 g of ribonucleic acid degradation product and 32 mg of trimethylthiourea were added. After optimal chemical sensitization at 60 ° C. for 80 minutes, 1.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene, 4.6 g of dye (a), 5.1 g of KBr, After sequentially adding 2.0 g of a stabilizer described below, the mixture was cooled. Thus, 28.1 kg of a monodisperse cubic silver chlorobromide emulsion having an average grain size of 0.40 μm was obtained.

[0046]

[Table 1]

[0047]

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Photosensitive silver halide emulsion (2) [for green-sensitive emulsion layer] A well-stirred gelatin aqueous solution (20 g of gelatin, 0.3 g of potassium bromide, sodium chloride 2 in 600 ml of water)
g) and 30 mg of compound (a) were added, and the mixture was kept at 46 ° C.). Solution (I) and solution (II) in Table 2 were simultaneously added at an equal flow rate for 9 minutes. After 5 minutes, the liquids (III) and (IV) in Table 2
The liquid was added simultaneously at an equal flow rate for 32 minutes. (III),
(IV) One minute after the completion of the addition of the solution, the methanol solution of the dye 60
ml (including 360 mg of Dye (b1) and 73.4 mg of Dye (b2)) were added all at once. After washing with water and desalting (using a precipitant (a) at pH 4.0) according to a conventional method,
22 g of lime-processed ossein gelatin was added, pH was adjusted to 6.0 and pAg was adjusted to 7.6 by adding appropriate amounts of NaCl and NaOH, and 1.8 mg of sodium thiosulfate and 4-hydroxy-6-methyl-1,3 were added. , 3a, 7-Tetrazaindene 1
80 mg was added thereto for optimal chemical sensitization at 60 ° C. Then, 90 mg of the antifoggant (1) was added, followed by cooling. Also,
70 mg of compound (b) and 3 ml of compound (c) were added as preservatives. Thus, 635 g of a monodispersed cubic silver chlorobromide emulsion having an average grain size of 0.30 μm was obtained.

[0049]

[Table 2]

[0050]

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[0051]

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Photosensitive silver halide emulsion (3) [for blue-sensitive emulsion layer] A well-stirred aqueous solution of gelatin (1582 g of gelatin, 127 g of KBr, 660 mg of compound (a) in 29.2 liters of water, and heated to 72 ° C.) Solution (I) and Solution (II) having the compositions shown in Table 3 were added to Solution (II), and after 10 seconds, Solution (I) was added over 30 minutes. Also,
Two minutes after the completion of the addition of the solution (I), the solution (V) is added. Five minutes after the completion of the addition of the solution (II), the solution (IV) is added.
The solution was added over a period of 27 minutes and 50 seconds for the solution (III) and 28 minutes for the solution (IV). Then, after washing with water and desalting (performed at pH 3.9 using 32.4 g of sedimentation agent (b)) in a conventional manner, 1230 g of lime-treated ossein gelatin and 2.8 mg of compound (b) were added to adjust the pH. 6.1, pAg 8.4
According to. Then, 24.9 mg of sodium thiosulfate
In addition, after optimal chemical sensitization at 65 ° C. for about 70 minutes, 13.1 g of the dye (c) and 118 ml of the compound (c) were sequentially added, followed by cooling. The silver halide grains of the obtained emulsion were potato-like grains, the grain size was 0.53 μm, and the yield was 3
It was 0.7 kg.

[0053]

[Table 3]

[0054]

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[0055]

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Next, how to prepare a gelatin dispersion of the compound (d) will be described. 0.2 g of compound (d), 1.2 g of compound (n), 1.2 g of high boiling organic solvent (1),
0.12 g of compound (f) and 0.25 g of compound (g)
g, 0.05 g of compound (h) and 0.2 g of surfactant (1), and 9.5 ml of ethyl acetate was added.
The mixture was dissolved by heating at a temperature of ° C. to form a uniform solution. After stirring and mixing 29.1 g of this solution and an 18% solution of lime-processed gelatin,
The mixture was dispersed with a homogenizer at 10,000 rpm for 10 minutes.
After dispersion, 18.5 ml of water for dilution was added. This dispersion is referred to as a dispersion of the compound (d).

[0057]

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Next, a method for preparing a dispersion of zinc hydroxide will be described. Zinc hydroxide 1 having an average particle size of 0.2 μm
2.5 g, carboxymethyl cellulose 1 as a dispersant
g and 0.1 g of sodium polyacrylate were added to 100 ml of a 4% aqueous solution of gelatin, and the mixture was milled for 30 minutes using glass beads having an average particle size of 0.75 mm. The glass beads were separated to obtain a dispersion of zinc hydroxide. Next, a method for preparing a gelatin dispersion of the dye-providing compound will be described. 7.3 g of cyan dye-donating compound (A1), 11.0 g of cyan dye-donating compound (A2), 0.8 g of surfactant (1), 1 g of compound (h), and compound (i) 2.2
g, 1.6 g of compound (o), 7 g of high-boiling organic solvent (1) and 3 g of high-boiling organic solvent (2), 26 ml of ethyl acetate and 1.2 ml of water were added, and the mixture was heated and dissolved at about 60 ° C. Thus, a uniform solution was obtained. 16% of this solution and lime-processed gelatin
After stirring and mixing 65 g of the solution and 87 ml of water, the mixture was dispersed with a homogenizer at 10,000 rpm for 10 minutes. After dispersion, 216 ml of water for dilution was added. This dispersion is referred to as a dispersion of a cyan dye-donating compound.

[0059]

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[0060]

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Magenta dye-donating compound (B)
50 g, compound (m) 0.05 g, compound (h) 0.05 g, compound (o) 0.5 g, surfactant (1) 0.094 g, and high boiling organic solvent (2) 2. 2
5 g was weighed, 10 ml of ethyl acetate was added, and the mixture was heated and dissolved at about 60 ° C. to form a uniform solution. This solution, 15.2 g of a 16% solution of lime-processed gelatin and 23.5 ml of water were stirred and mixed, and then dispersed with a homogenizer at 10,000 rpm for 10 minutes. Thereafter, 42 ml of water for dilution was added. This dispersion is referred to as a dispersion of a magenta dye-donating compound.

[0062]

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The yellow dye-donating compound (C) was added to 15
g, 2.3 g of compound (d) and 0.9 g of compound (h)
g, surfactant (1) 0.88 g, compound (j) 3.9 g, compound (k) 1.9 g, compound (o) 1.5 g, and high boiling organic solvent (1) 16. 9g is weighed,
Ethyl acetate (49 ml) was added, and the mixture was dissolved by heating at about 60 ° C. to form a uniform solution. This solution, 63.5 g of a 16% solution of lime-processed gelatin and 103 ml of water were stirred and mixed, and then dispersed with a homogenizer for 10 minutes at 10,000 rpm. Thereafter, 94 ml of water for dilution was added. This dispersion is referred to as a yellow dye-donating compound dispersion.

[0064]

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Thus, the photothermographic materials 101 as shown in Tables 4, 5, and 6 were formed. Further, in addition to the halogenated emulsion (1) of the red-sensitive layer, a halogenated emulsion (1-2),
In the same manner except that the halogenated emulsion (1-3) was added,
A photothermographic material 102 was prepared. The addition amount was 0.06 g / m ² of the silver halide emulsion (1) and the silver halide emulsion (1).
-2) 0.05 g / m ² , halogenated emulsion (1-3) 0.0
It is 5 g / m ² .

[0066]

[Table 4]

[0067]

[Table 5]

[0068]

[Table 6]

[0069]

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[0070]

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[0071]

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Next, a method for producing the image receiving material will be described. Image receiving materials R201 having the structures shown in Tables 7 and 8 were produced.

[0073]

[Table 7]

[0074]

[Table 8]

[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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The exposure apparatus used was an array exposure head in which blue, green, and red 60 μm LED light sources were arranged in 500 lines of each color. LED wavelength is blue LE
D was 455 nm, the green LED was 534 nm, and the red LED was 665 nm. 10m of photosensitive material
Exposure was performed at a transport speed of m / sec. FIG. 1 shows the characteristic curve of the red-sensitive layer obtained by exposing the red LED of the photosensitive material 101, and FIG. The density is cyan density. The inclination of the tangent line at each inflection point a to e in FIG. 2 is as described above. A dampening solution was supplied to the emulsion surface of the photosensitive material after exposure with a wire bar, and then the image receiving material R2
01 and the film surface were in contact with each other. Thermal development temperature 8
After heating at 6 ° C. for 40 seconds, the image receiving material was peeled off from the photosensitive material, and the density of the obtained image was measured.

Next, the exposure conditions of the above photosensitive materials 101 to 102 were adjusted so as to obtain a uniform gray of 0.8. Here, the exposure amounts are 0.2, 1.2,
Exposure was performed at only four values of 2.0 and 3.0. Next, after turning on the LED exposing machine for 20,000 hours, the photosensitive material 1
No. 01-102, exposure was performed under exactly the same exposure conditions, dampening water was supplied to the emulsion surface of the exposed light-sensitive material with a wire bar, and then the image-receiving material R201 was superposed so that the film surface was in contact therewith. . After heating at a heat development temperature of 86 ° C. for 40 seconds, the image receiving material was peeled off from the photosensitive material, and the density of the obtained image was measured with a 10 μm aperture.

The presence or absence of density unevenness of the obtained gray image was examined. Before the LED exposing machine was turned on for 20,000 hours, the photosensitive materials 101 and 102 did not show any unevenness visually. Also in the concentration measurement, there was only a concentration fluctuation within 0.005. However, after the LED exposing machine was turned on for 20,000 hours, clear density unevenness was visually detected in the photosensitive material 101. 0.07 max. In density measurement
Concentration fluctuation. In the image output from the photosensitive material 102 of the present invention, density unevenness was hardly visible. Also in the concentration measurement, there was only a maximum fluctuation of 0.004.

[0083]

The silver halide photographic emulsion of the present invention has a short exposure time and a small change in density due to a change in light source, and is suitable for digital exposure. Therefore, a light-sensitive material using this silver halide photographic emulsion is suitable for forming a stable digitally exposed image without image unevenness, and is particularly suitable as a heat-developable light-sensitive material.

[Brief description of the drawings]

FIG. 1 shows a conventional general characteristic curve.

FIG. 2 shows a characteristic curve of a photosensitive material obtained according to an example of the present invention.

Claims (3)

[Claims] 1. A characteristic curve showing the relationship between logarithmic exposure and density has three or more inflection points within a range from a logarithmic exposure at which the minimum density is obtained to a logarithmic exposure at which the maximum density is obtained. And the slope of the tangent drawn at each inflection point (tan
.theta.) having the property of alternately being 3 or more and 1 or less. 2. The photosensitive silver halide emulsion according to claim 1, wherein the emulsion is used for digital exposure. 3. A characteristic curve showing the relationship between logarithmic exposure and density on a support, wherein three or more logarithmic exposures are obtained within a range from a logarithmic exposure at which a minimum density is obtained to a logarithmic exposure at which a maximum density is obtained. At least one photosensitive silver halide emulsion layer having an inflection point and having a characteristic that the inclination (tan θ) of a tangent line drawn at each inflection point is alternately 3 or more and 1 or less. A photosensitive material characterized by the following: