JPH0369938A - Image forming method and heat developable color photosensitive material - Google Patents

Abstract

PURPOSE:To improve the light resistance and fixability of a dye image by forming a diffusible dye by heat development and chelating the formed dye. CONSTITUTION:A heat developable color photosensitive material having a layer contg. at least photosensitive silver halide, a reducing agent, a binder and a coupler forming a diffusible dye by a reaction with the oxidized product of the reducing agent on the support is heat-developed to form the diffusible dye. This dye is transferred to an image receiving material during and/or after the development and chelated with metal ions in the image receiving material to form a dye image having the max. absorption wavelength at 400-700nm. Thus, a color image having high density, low fog, improved fixability and light resistance, that is, improved stability can be obtd. by heat development.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming method and a heat-developable color photosensitive material used in carrying out the method. More specifically, the present invention relates to an image forming method in which a color image is formed on an image-receiving material by transferring a dye formed by a coupling color-forming reaction during heat development, and a heat-developable color photosensitive material used therein.

[Background of the invention]

A photosensitive material (thermally developable photosensitive material) that can easily and quickly form an image by carrying out a dry process using heat in the development process is well known. Publication No. 43-4924, "Fundamentals of Photographic Engineering" Silver Salt Photographic Line (Published by Corona Publishing in 1879)
pages 553-555, and Research Disclosure magazine, June 1978 issue, pages 9-15 (RD-1702
9) etc.

There are two types of heat-developable photosensitive materials: those that produce black-and-white images and those that produce color images. In recent years, in particular, attempts have been made to develop heat-developable color photosensitive materials that produce color images using various dye-providing substances.

There are still various methods for heat-developable color photosensitive materials, such as a method in which a color image is obtained by releasing or forming a diffusible dye through heat development and then transferring the dye (
This method (hereinafter referred to as a transfer method) is superior in terms of image stability and clarity, and processing simplicity and speed. This transfer method heat-developable color photosensitive material and image forming method are described in, for example, Japanese Patent Application Laid-open Nos. 59-12431 and 59-15915.
No. 9, No. 59-181345, No. 59-229556
No. 60-2950, No. 61-52643, No. 6
No. 1-61158, No. 61-61157, No. 59-1
No. 80550, No. 61-132952, No. 61-13
No. 2952 and the specifications of US Pat. No. 4,595.652, US Pat. No. 4,590.154, and US Pat. No. 4,584.267.

By the way, the method of forming a color image by transferring a dye that forms or releases a dye through a coupling color-forming reaction during thermal development is an excellent method for forming a color image through a complete dry process. In the method of releasing dyes through a color reaction, the color forming dyes that are formed at the same time do not contribute to the transferred color image, resulting in problems such as waste of dyes and a decrease in sensitivity due to the light-sensitive material being colored during exposure. However, the method of forming a diffusible dye through a coupling color reaction and transferring the dye to form a color image was superior.

However, this method has a problem in that the stability of the color image formed, particularly its fixing properties and light fastness, are insufficient. Further, since the maximum density and fog vary greatly with variations in thermal development conditions, it is necessary to control the thermal development conditions with high accuracy, and there is also the problem that the load on the thermal development apparatus is large. Furthermore, in this type of image forming method and heat-developable color light-sensitive material, there has been a demand for further improvement in the discrimination between maximum density and fog, and further reduction in development time. There has also been a demand for improvement in the utilization efficiency of the formed dye for images.

On the other hand, a technology has been proposed in which a metal ion compound (complex) is contained in the image-receiving layer of an image-receiving material, and another technology has been proposed in which a dye capable of metal chelation is released through coupling and a chelate dye is formed in the image-receiving layer. has been done.

Such technology is disclosed in Japanese Patent Application Laid-Open No. 59-48765, 57-
It is proposed in No. 229647.

However, in such known techniques, a chelatable dye is substituted in advance at the active site of the coupler, and reacts with the oxidized form of the reducing agent to "release" the diffusible dye. Therefore, the dyes produced at the same time are not used for image formation, resulting in problems such as low utilization efficiency of silver halides, couplers, and other additives (e.g., organic silver salts, reducing agents), and limitations on the number of active site substituents. Because of this, the coloring efficiency of the coupler was low.

[Purpose of the invention]

The present invention has been made in view of the problems of the prior art described above.

That is, an object of the present invention is to be able to obtain color images with high density, low capri, and improved fixability and light resistance, that is, image stability, by thermal development, and which is resistant to fluctuations in developing conditions. On the other hand, it is an object of the present invention to provide an image forming method with small fluctuations in maximum density and fog, and a heat-developable color photosensitive material.

In addition, the thermal development time can be shortened, and the various substances contained in the photosensitive material (silver halides, couplers, reducing agents, and organic silver salts contained as needed and geothermal additives) can be used more efficiently. The object of the present invention is to provide an image forming method and a heat-developable color light-sensitive material, which have good color properties and improve the utilization efficiency of dyes formed by heat development, thereby making it possible to reduce the amount of silver, coupler, etc. added.

[Structure of the invention]

The image forming method of the present invention includes a thermal development process comprising, on a support, a layer containing at least a photosensitive silver halide, a reducing agent, a binder, and a coupler that reacts with an oxidized product of the reducing agent to form a diffusible dye. heat-developing the color photosensitive material to form a diffusible dye; transferring the diffusible dye to an image-receiving material simultaneously with and/or after the heat-development;
It is characterized by forming a dye image having a maximum absorption wavelength of 400 to 700 nm by chelating the diffusible dye with metal ions in the image-receiving material.

Further, the heat-developable color photosensitive material of the present invention has a layer containing at least a photosensitive silver halide, a reducing agent, a binder, and a color that reacts with an oxidized product of the reducing agent to form a diffusible dye. In the photosensitive material, the J coupler or the reducing agent has a group selected so that the formed diffusive dye has a chelatable structure, and the maximum absorption wavelength of the formed dye image. is 400~700n
+m.

As a result of intensive research, the present inventors have discovered that the object of the present invention can be achieved by having the above configuration, and have accomplished the present invention.

In the present invention, a diffusible dye is not "released" but "formed" by heat development, and this dye is chelated. Therefore, the fixability of the resulting dye image is improved, and the utilization efficiency of each compound in the light-sensitive material is also improved, thereby achieving the object of the present invention. For example, it is possible to significantly improve the rate at which the coupler contributes to color development.

The present invention will be explained in more detail below.

First, a coupler (hereinafter referred to as "the coupler of the present invention" or simply "coupler" as appropriate) that reacts with the oxidized form of the reducing agent used in the present invention to form a diffusible dye will be described.

The coupler of the present invention is contained in the photosensitive layer of the heat-developable color photosensitive material of the present invention.

The dyes formed by the couplers of the present invention react with metal ions (preferably transition metal ions) to form metal chelates in or near the image receiving layer. The coupler thus has groups selected such that the dye formed is a chelatable structure. In other words, it has a group capable of metal chelation as a substituent (however, it has it in a group other than the active site substituent (hereinafter referred to as coupler residue)), or it has a chromophore group of the formed dye. and a substituent on the coupler and/or a substituent on the reducing agent (hereinafter simply referred to as reducing agent) coupled with the coupler, which has a substituent that can be chelated with a metal ion. However, if the reducing agent has the chelatable substituent, the chelatable substituent may not be necessary on the coupler. and/or the reducing agent may have a group selected such that the dye can be chelated.

Further, it is preferable that the coupler itself be immobile so as to form a diffusible dye through a coupling reaction, and for this reason it is preferable that the coupler has a ballast group at its active site.

The ballast group preferably has 8 or more carbon atoms, more preferably 12 or more carbon atoms, and even more preferably a group that is a polymer chain.

The coupler having a group as a polymer chain is preferably one having a polymer chain having a repeating unit derived from a monomer represented by the following format (1) as the above group.

- Format (1) % formula %)) In the formula, C2' is an organic group (coupling reaction) that can react with the oxidized product of the reducing agent to form a diffusible dye.
J represents a divalent bonding group bonded to the active position that reacts with the oxidized form of the reducing agent, Y represents an alkylene group, arylene group, or aralkylene group, and l
represents 0 or l, Z represents a divalent organic group, and L represents an ethylenically unsaturated group or a group having an ethylenically unsaturated group.

Next, the case where the coupler of the present invention has a group capable of metal chelation as a substituent on the coupler residue will be explained. This type of coupler has the following format (2).
).

In the formula, CI represents an organic group (coupler residue) that can react with the oxidized form of the reducing agent (coupling reaction) to form a diffusible dye, and J is defined in general formula (1). A is a group having a ligand capable of chelating with a metal ion, and B is a ballast group.

As the ligand possessed by the above A, for example, chelate chemistry (
5) Examples include the ligands described in Keihei Ueno's collection (Nankodo).

Further, together with the coordination group on A, the carbonyl group of the formed coloring dye may be used as one ligand to form a metal chelate together with other coordination groups on the coupler residue.

Particularly preferred as A are residues of chelatable dyes. The residue has the following format (3) or (
A dye residue obtained by removing one hydrogen atom from the dye represented by 4) is preferable.

In the formula, XI represents an atomic group necessary to form an aromatic carbocycle or heterocycle in which at least one ring is composed of 5 to 7 atoms, and At least one carbon atom in the position is a nitrogen atom, or a carbon atom substituted with a nitrogen atom, an oxygen atom, or a sulfur atom, and X2 is an aromatic carbocyclic ring in which at least one ring is composed of 5 to 7 atoms. or represents an atomic group necessary to complete a heterocycle, and G represents a chelating group.

Furthermore, the ring represented by (+ and Xz) may have a substituent on the ring.

General formula (4) In the formula, X1 has the same meaning as defined in general formula (3), Zl represents an electron-withdrawing group, and Zl represents an alkyl group or an aryl group.

Specific examples of the group represented by form (3) or (4) include those described in JP-A-59-48765.

As another type, a case where the coupler of the present invention performs metal chelation using a chromophore group of a coloring dye will be described.

In this type of coupler, at least one carbon atom adjacent to the active site carbon atom is preferably substituted with a nitrogen atom, oxygen atom or sulfur atom. In addition, when using this type of coupler, the reducing agent is a group that performs a coupling reaction with the coupler (
It is preferable that the carbon atom adjacent to the carbon atom substituted with (usually an amino group) is substituted with a nitrogen atom, an oxygen atom, or a sulfur atom.

Specific examples of the coupler represented by the general formula (2) that can be used in the present invention are shown below, but it goes without saying that the coupler of the present invention is not limited to these.

Coupler (1) Coupler (2) Coupler (4) Coupler (5) Coupler (3) H3 →CHzC)y iBA) -v- Coupler (6) Coupler (7) :50% by weight Coupler (8) Coupler (lO) Coupler (9) Coupler (11) Coupler (12) Coupler (13) Coupler (15) Coupler (16) OOH llz Coupler (14) Coupler (17) Coupler (18) Coupler (19) Coupler (21) Coupler (20) Coupler (22) Coupler (23) 1’l)l It can be obtained by such things.

A specific synthesis example of the above-mentioned exemplified compound coupler (1) of the present invention is shown below. Coupler (1) is synthesized by the following reaction route.

In addition, BA: n-butyl acrylate EA: Ethyl acrylate It is.

The coupler represented by general formula (2) of the present invention can be synthesized by the following method. That is, (1)C,”-J
After synthesizing -B, introducing separately synthesized A (2) A-CPz and then introducing J-B (3) C, -J
After introducing A, introducing B (4) C having an anilino group, 2-J or Cpz-J
After diazotizing -B (the anilino group is on CI), a coupling reaction is performed with an appropriate coupler (in the case of C1, "-J, B is subsequently introduced). ■ lIr ■ Coupler (1) * That is, 23.Og of compound (1) and 33.2 g of compound (1) were added to 250 d of water and heated and stirred on a steam bath for 6 hours.After the reaction, the solid was filtered off and purified by column chromatography to obtain 8.6 g of compound (1). The entire amount of the compound (1) was added to 50 d of thionyl chloride, and after reacting for 3 hours, the excess thionyl chloride was distilled off to obtain the compound (2). was added to the mixed solution and stirred.

The entire amount of the above compound (1) was added to this solution and reacted for 2 hours, and the resulting solid was filtered off and purified by column chromatography to obtain 15.2 g of compound (1).

The above compound ■5. Og, n-butyl acrylate 5.
0 g, dissolved in dimethylformamide 100/d,
It was heated to 80"C under a nitrogen stream. 0.3 g of azobisisobutyronitrile was added as a polymerization initiator, and the mixture was heated for 2 hours.
The reaction was carried out at 80 to 84°C, and 0.3 g of an initiator was added, and the reaction was carried out at 80 to 84°C for 2 hours. The reaction solution was poured into pure water, and the precipitated solid was filtered off and dried to obtain 13.7 g of the target coupler (1).

In carrying out the present invention, one type of the coupler of the present invention may be used alone, or two or more types thereof may be used. Furthermore, U.S. Patent No. 4,631.251, U.S. Pat.
No. 4,650,748, patent application No. 1982-132751
It may be used in combination with the dye-providing substance described in No. 1, etc.

The amount of the coupler of the present invention (and the dye-providing substance used together if necessary) is not limited, and the type of dye-providing substance,
It may be determined depending on whether N is used alone or in combination of two or more types, the photographic structure e of the photosensitive material of the present invention, and whether N is a single layer or a multilayer of two or more types. 1r
0.005 g to 50 g per I'f, preferably 0.00 g to 50 g per I'f.
It can be used in amounts of 1 g to Log.

The method of incorporating the coupler of the present invention and other dye-providing substances into the photographic constituent layer of the heat-developable light-sensitive material is arbitrary. phthalate, tricresyl phosphate, etc.) and then subjected to ultrasonic dispersion, or dissolved in an alkaline aqueous solution (e.g., 10% aqueous sodium hydroxide solution, etc.), and then treated with a mineral acid (e.g., hydrochloric acid or nitric acid, etc.). It can be used after being neutralized, or after being dispersed in a ball mill with an aqueous solution of an appropriate polymer (eg, gelatin, polyvinyl butyral, polyvinylpyrrolidone, etc.).

Next, the image-receiving material and image-receiving layer of the present invention will be explained.

In the present invention, the image-receiving material may be constructed separately from the photothermographic material, and the image-receiving layer may be formed on the image-receiving material, or the image-receiving layer may be formed integrally with the photosensitive material.

The image-receiving material or image-receiving layer of the present invention has the function of receiving the dye in the heat-developable photosensitive material and the function of supplying metal ions to the dye, and these functions allow the dye to be diffused onto the image-receiving material (image-receiving layer). A metal chelated dye image is formed by the dye and the metal ion. However, during dye transfer, the vicinity of the image-receiving material (image-receiving layer), such as the topmost layer of a photosensitive material, has the function of supplying metal ions, and after the dye is chelated in the vicinity, the dye is transferred onto the image-receiving material. When an image is formed, the image-receiving material does not need to have a metal ion supply function.

Compounds having a metal ion supplying function may be metal ion salts (e.g. carboxylates, sulfonates), or complexes (e.g. compounds described in Chelate Chemistry (5), Ueno Quantum Editing (Nankodo)). metal complexes) may also be used.

The metal ion is a divalent transition metal (preferably divalent nickel, copper, zinc, cobalt, platinum, and palladium)
Ions are preferred.

The amount of the compound added is preferably 0.1 times to 10 times the amount of the coupler added in the photosensitive material.

The addition method can be carried out in the same manner as the coupler addition method described above, in which the coupler is dissolved or dispersed in a low-boiling point or high-boiling point solvent such as those exemplified, and then dissolved/dispersed together with the polymer forming the image-receiving layer. It can be added by coating.

The compound having the function of receiving a dye (dye-receiving substance) may be any compound having the function of receiving the dye in the heat-developable photosensitive layer released or formed by heat development.
For example, polymers containing tertiary amines or quaternary ammonium salts, such as those described in US Pat. No. 3,709,690, are preferably used. Typical image-receiving layers for diffusion transfer include those obtained by mixing a polymer containing ammonium salt, tertiary ammonium, etc. with gelatin, polyvinyl alcohol, etc., and coating the mixture on a support. As another useful dye-receiving material, JP-A-57-2
The glass transition temperature described in 07250 etc. is 40
Examples include those formed of organic polymeric substances that are heat-resistant at temperatures of .degree. C. or higher and 250.degree. C. or lower.

These polymers may be supported on a support as an image-receiving layer, or may themselves be used as a support.

Regarding polymers, "Polymer Handbook, Second Edition" (edited by Joy Brandrup and E.H. Inmargat), published by John Willi and Sons (Polymer Handbook 2nd Edition)
ed, (J, Brandrup, E, H, Ia+m
ergutli) John Wiley & 5on
Also useful are platform polymers with glass transition temperatures of 40° C. or higher, as described in s).

- For boat fishing, the molecular weight of the polymer substance is 2000~
200,000 is useful. These polymeric substances may be used alone or in a blend of two or more thereof, or may be used in combination of two or more as a copolymer.

Particularly preferred dye-receiving materials include JP-A-59-22
Examples include a layer made of polyvinyl chloride described in Japanese Patent Publication No. 3425, and a material made of polycarbonate and a plasticizer described in Japanese Patent Application Laid-Open No. 19138-1983.

These polymers can also be used as a support and an image-receiving layer (image-receiving material), in which case the support may be formed from a single layer or from multiple layers. good.

As the support for the image-receiving material, transparent supports, opaque supports, etc. may be used, but for example, films of polyethylene terephthalate, polycarbonate, polystyrene, polyvinyl chloride, polyethylene, polypropylene, etc.
and supports containing pigments such as titanium oxygen, barium sulfate, calcium carbonate, and talc, baryta paper, resin-coated paper in which thermoplastic resin containing pigments is laminated on paper, and cloth. , glasses, metals such as aluminum, etc., and supports on which electron beam curable resin compositions containing pigments are coated and cured; Examples include a support provided with a coating layer. Furthermore, various coated papers such as cast coated paper described in JP-A No. 62-283333 are also useful as supports.

In addition, a support with a pigment-containing electron beam curable resin composition coated and cured on paper, or a support with a pigment coating layer on paper and an electron beam curable resin composition on the pigment coating layer. The resin layer of the support coated with and cured can be used as an image-receiving layer, so it can be used as is as an image-receiving member.

Appropriate additives, such as various known additives, can be added to the image-receiving layer. Examples of such additives include:
Examples include ultraviolet absorbers, image stabilizers, development accelerators, antifoggants, pH adjusters (dilute acids and acid precursors, bases and base precursors, etc.), and thermal solvents.

Typical examples of ultraviolet absorbers include benzotriazole compounds and benzophenone compounds. Examples of image stabilizers include hindered amine type, hindered phenol type, dialkoxybenzene type, chroman type, indane type, thioether type,
Examples include hydroquinone-based compounds, chlorine-substituted s-)riazine-based compounds, and the like. The development accelerator and antifoggant can be appropriately selected from compounds added to heat-developable photosensitive materials.

The heat-developable photosensitive material of the present invention is disclosed in RD (Research Disclosure Magazine> No. 15108, JP-A-57-1984).
No. 58, No. 57-207250, No. 61-80148
The photothermographic material may be a so-called monosheet type photothermographic material in which a photosensitive layer and an image-receiving layer are formed on the same support, as described in the above publication.

Next, the photosensitive silver halide used in the present invention will be described. Any silver halide can be used, and examples thereof include silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, and silver iodobromide. The photosensitive silver halide can be prepared by any method commonly used in the photographic art.

Furthermore, it is possible to use an emulsion containing grains having a multilayer structure in which the halogen composition of the grains differs on the surface and inside. For example, a silver halide emulsion having core/shell type silver halide grains in which the halogen composition changes stepwise or continuously can be used.

In addition, the shape of photosensitive silver halide is cubic, spherical, 8
It is possible to use materials that have a clear crystal habit, such as a hedron, dodecahedron, and tetradecahedron, or those that do not. This type of silver halide is described in JP-A-60-215948.

Also, for example, JP-A-58-111933, JP-A No. 5B-1
No. 11934, No. 58-108526, Research Disclosure No. 22534, etc., each of which has two parallel crystal planes, and each of these crystal planes is larger than the other single crystal of this particle. It is also possible to use a silver halide emulsion containing tabular silver halide grains having a large area and an aspect ratio, that is, a ratio of grain diameter to thickness of 5:1 or more.

Further, in the present invention, a silver halide emulsion containing internal latent image type silver halide grains whose surfaces have not been fogged in advance can be used. For internal latent image type silver halide whose surface is not prefogged, for example, U.S. Pat.
．． 592.250, 3,206.313, 3,
317.322, 3,511.622, 3.4
No. 47.927, No. 3,76L266, No. 3,703
．． It is described in various specifications such as No. 584 and No. 3,736.140.

Internal latent image type silver halide grains whose surfaces are not fogged in advance are silver halide grains in which the sensitivity inside the grain is higher than the sensitivity on the surface of the silver halide grain, as described in each of the above specifications. be. Also, U.S. Patent No. 3,271.15
No. 7, No. 3,447.927 and No. 3.531,
Silver halide emulsions having silver halide grains incorporating polyvalent metal ions as described in U.S. Pat. No. 291, or silver halide containing dopants as described in U.S. Pat. Silver halide emulsion whose grain surface is weakly chemically sensitized, or JP-A-50-852
Silver halide emulsions comprising grains having a laminated structure as described in publications such as No. 4 and No. 50-38525, and other publications such as JP-A-52-156614 and JP-A-55-127.
Silver halide emulsions such as those described in No. 549 can be used.

The silver halide in the above-mentioned photosensitive emulsion may have coarse or fine grains, but the preferred grain size is about 0.005 μm to about 1.5 μm, more preferably about 0.005 μm to about 1.5 μm, and more preferably about , oiμm-0.5μm.

In the present invention, as another method for preparing photosensitive silver halide, a photosensitive root salt-forming component may be allowed to coexist with an organic silver salt described below to form photosensitive silver halide in a part of the organic silver salt.

These photosensitive silver halides and photosensitive silver salt-forming components can be used in combination in various ways, and the amount used is preferably Q, OQl g to 50 g per 1 d of support per layer, More preferably, it is 0.1 to 10 g.

The light-sensitive silver halide emulsion may be chemically sensitized by any method in the photographic art.

Further, the photosensitive silver halide emulsion used can be spectral sensitized using a known spectral sensitizing dye to impart sensitivity to blue, green, red, and near-infrared light.

Typical spectral sensitizing dyes that can be used include, for example, cyanine, merocyanine, complex (that is, trinuclear or tetranuclear) cyanine, holobola-cyanine,
Examples include styryl, hemicyanine, oxonol, and the like.

The preferred amount of these sensitizing dyes to be added is 1×10 −
b mole - 1 mole. More preferably, I Xl0-
' ~ 1 x 10-1 mol.

The sensitizing dye may be added at any stage of the preparation of the silver halide emulsion. That is, it may be carried out at any time, such as when silver halide grains are formed, when soluble salts are removed, before the start of chemical sensitization, during chemical sensitization, or after the end of chemical sensitization.

In the heat-developable photosensitive material of the present invention, it is preferable to use various organic silver salts, if necessary, for the purpose of increasing sensitivity and improving developability.

Examples of organic silver salts that can be used in the heat-developable photosensitive material of the present invention include JP-A Nos. 53-4921 and 49-5262.
No. 6, No. 52-141222, No. 53-36224, No. 53-37626, and No. 53-37610, as well as U.S. Patent Nos. 3,330.633 and 3.794,496, Silver salts of long-chain aliphatic carboxylic acids and silver salts of carboxylic acids having heterocycles, such as silver behenate, α-( 1-phenyltetrazolethio)silver acetate, etc., and Japanese Patent Publication No. 1982-26582, No. 45-
No. 12700, No. 45-18416, No. 45-221
No. 85, JP-A-52-137321, JP-A No. 58-118
No. 638, No. 5B-118639, U.S. Patent No. 4.1
There are silver salts of imino groups described in various publications such as No. 23.274.

Among the above organic silver salts, imino group silver salts are preferred;
Particularly preferred are silver salts of benzotriazole derivatives, more preferably 5-methylbenzotriazole and its derivatives, sulfobenzotriazole and its derivatives, and N-alkylsulfamoylbenzotriazole and its derivatives.

The organic silver salts used in the present invention may be used alone or in combination of two or more. Alternatively, the silver salt may be prepared in a suitable binder and used as is without isolation.
The isolated product may be used after being dispersed in a binder by an appropriate means. Dispersion means include, but are not limited to, ball mills, sand mills, colloid mills, vibration mills, and the like.

The amount of the organic silver salt used is generally preferably 0.01 to 500 moles, more preferably 0.1 to 100 moles per mole of photosensitive silver halide. More preferably 0.
It is 3 to 30 moles.

The heat-developable color photosensitive material of the present invention includes a reducing agent (a reducing agent precursor is also included in the reducing agent herein).
However, those commonly used in the field of heat-developable photosensitive materials can be used.

Examples of reducing agents that can be used in the present invention include U.S. Pat. No. 3,531,286 and U.S. Pat.
No. 0, the specifications of No. 3,764,328, and RD (
Research Disclosure) 11m12146,
Same sex 15108, same sex 15127 and JP-A-56-27
No. 132, U.S. Pat. No. 3,342,599. No. 3,719.492 Specifications, JP-A-53-135
p described in each publication such as No. 628 and No. 57-79035
- Phenylenecyamine-based and p-aminophenol-based developing agents, phosphor-and-dophenol-based, sulfonamide aniline-based developing agents, hydrazone-based color developing agents and their precursors, or phenols, sulfonamide phenols, or Polyhydroxybenzenes, naphthols, hydroxybinaphthyls and methylene bisnaphthols, methylene bisphenols,
Ascorbic acid, 3-pyrazolidones, and pyrazolones can be used.

As a particularly preferable reducing agent, JP-A-56-146133
N-(p-
N.

N-dialkyl) phenylsulfamate can be mentioned.

Two or more types of reducing agents may be used simultaneously.

The amount of the reducing agent used in the heat-developable photosensitive material of the present invention depends on the type of photosensitive silver halide used, the type of organic acid silver salt, the type of other additives, etc., and is not necessarily constant. The amount is generally preferably from 0.01 to 1,500 mol, more preferably from 0.1 to 200 mol, per mol of photosensitive silver halide.

Binders that can be used in the heat-developable photosensitive material of the present invention include polyvinyl butyral, polyvinyl acetate,
These include synthetic or natural polymeric substances such as ethyl cellulose, polymethyl methacrylate, cellulose acetate butyrate, polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, gelatin derivatives such as phthalated gelatin, cellulose derivatives, proteinaceous substances, starch, and gum arabic. These can be used alone or in combination of two or more. In particular, it is preferable to use gelatin or a derivative thereof together with a hydrophilic polymer such as polyvinylpyrrolidone or polyvinyl alcohol, and more preferably to use a mixed binder of gelatin and polyvinylpyrrolidone described in JP-A-59-229556. That's true.

The preferred amount of binder used is usually 0.05 g to 50 g per 1 support, more preferably 0.2 g.
~20g.

In addition, the binder is 0.1% per 1g of the dye-providing substance.
It is preferable to use ~10g, more preferably 0.2
~5g.

The heat-developable photosensitive material of the present invention can be obtained by forming a photographic constituent layer on a support, and examples of the support that can be used here include polyethylene film, cellulose acetate film, polyethylene terephthalate film, etc. Synthetic plastic films such as polyvinyl chloride, paper supports such as photographic base paper, printing paper, baryta paper, and resin coated paper, and electron beam curable resin compositions coated and cured on these supports. Examples include supports.

It is preferable that various thermal solvents be added to the photographic constituent layer or image-receiving layer of the heat-developable photosensitive material of the present invention. The thermal solvent is a compound that is liquid during thermal development and promotes thermal development and/or thermal transfer.

These compounds include, for example, U.S. Pat.
．． 675. No. 3.667.959, RD (Research Disclosure) No. 17643 (X II
'), JP-A-59-229556, JP-A No. 59-687
No. 30, No. 59-84236, No. 60-191251
No. 60-232547, No. 60-14241,
No. 61-52643, No. 62-78554, No. 62
-42153, U.S. Patent No. 62-4213, etc., U.S. Pat.
No. 5, No. 53-24829, No. 53-60223,
Examples of organic compounds having polarity such as those described in JP 58-118640 and JP 58-198038 include urea derivatives (such as dimethyl urea, diethylurea, phenylurea, etc.), amide derivatives (e.g., acedoamide, benzamide, p-)ylamide, etc.),
Examples include sulfonamide derivatives (e.g. benzenesulfonamide, α-toluenesulfonamide, etc.), polyhydric alcohols (e.g. 1,6-hexanediol, 1,2-cyclohexanediol, pentaerythritol, etc.), or polyethylene glycols. .

Among the above thermal solvents, water-insoluble solid thermal solvents are particularly preferably used.

Specific examples of the above-mentioned water-soluble heat solvent include, for example, JP-A-62
-136645, 62-139549, 63-
Some of them are described in Japanese Patent Application No. 53548, Japanese Patent Application No. 63-205228, and Japanese Patent Application No. 63-54113.

Examples of the layer to which a heat solvent is added include a photosensitive silver halide emulsion layer, an intermediate layer, a protective layer, an image receiving layer of an image receiving member, etc., and the heat solvent is added to each layer so as to obtain an effect depending on each layer.

The preferred amount of the heat solvent added is usually 10% to 500% by weight, more preferably 30% to 200% by weight of the binder amount.
Weight%.

The organic silver salt and the thermal solvent may be dispersed in the same dispersion. The same binder, dispersion medium, and dispersion device as used for producing each dispersion can be used.

In addition to the above-mentioned components, the photothermographic material of the present invention may contain various additives, such as a development accelerator, an antifoggant, a base breaker, etc., if necessary.

As development accelerators, compounds described in JP-A-59-177550, JP-A-59-111636, and JP-A-59-124333 are used, as well as compounds described in JP-A-61-159642 and JP-A-62-203908. The development accelerator-releasing compounds described above or metal ions having an electronegativity of 4 or more as described in Japanese Patent Application No. 104645/1988 can also be used.

Examples of antifoggants include those described in US Pat. No. 3,645.
Higher fatty acids described in specification No. 739, Japanese Patent Publication No. 4
Second mercury salt described in Publication No. 7-11113, JP-A-51
-N-halogen compound described in Publication No. 47419, U.S. Patent No. 3,700,457, JP-A-51-50
Mercapto compound releasing compound described in Publication No. 725,
Aryl sulfonic acids described in JP 49-125016, carboxylic acid lithium salts described in JP 51-47419, British Patent No. 1,455,271, and JP-A-50-101.019. The oxidizing agent described in 53
-Sulfinic acids or thiosulfonic acids described in Publication No. 19825, 2-thiouracils described in Publication No. 51-3223, simple sulfur described in Publication No. 5126019,
No. 51-42529, No. 51-81124, No. 55
Disulfide and polysulfide compounds described in Publication No. 93149, rosin or diterpenes described in Publication No. 51-57435, polymer acids having free carboxyl groups or sulfonic acid groups described in Publication No. 51-104338, U.S. patents Thiazolinthion as described in No. 4, 138.265, JP-A-54-51821
1,2,4-triazole or 5-mercapto- as described in US Pat. No. 4,137.079
1,2,4-1-Riazole, JP-A-55-14088
Thiosulfinate esters described in No. 3, No. 55-1
l,2゜3.4-thiatriazoles described in Publication No. 42331, No. 59-46641, No. 59-57233
No., dihalogen compounds or trihalogen compounds described in Publication No. 59-57234, and furthermore, No. 59-111.
Thiol compound described in Publication No. 636, 6°-198
Hydroquinone derivatives described in Publication No. 540, 60-
Examples include the combined use of a hydroquinone derivative and a benzotriazole derivative described in Japanese Patent No. 227255.

Still another particularly preferred antifoggant is disclosed in JP-A No. 6
2-785!54, polymer inhibitors described in JP-A-62-121452, and ballast-group-containing inhibitors as described in JP-A-62-123456. Examples include agents.

Furthermore, colorless couplers described in Japanese Patent Application No. 62-320599 are also preferably used.

Examples of base precursors include compounds that release basic substances by decarboxylation upon heating (e.g., guanidinium trichloroacetate), compounds that decompose through reactions such as intramolecular nucleation substitution reactions, and release amines, etc. For example, Japanese Patent Application Publication No. 56-130745, Japanese Patent Application Publication No. 56-132332, British Patent No. 2.079.480, and US Patent No. 4.0.
Specification No. 60,420, JP-A-59-157637,
No. 59-166943, No. 59-180537, No. 59-174830, No. 59-195237, No. 6
Examples include base releasing agents described in JP2-108249, JP62-174745, and the like.

In addition, various additives used in heat-developable photosensitive materials as necessary, such as antihalation dyes, fluorescent brighteners, hardeners, antistatic agents, plasticizers, spreading agents, matting agents, and surfactants. , an antifading agent, etc., and these are specifically described in RD (Research Disclosure) Magazine Vol.

170. June 1978, No. 17029, JP-A-62-
It is described in Publication No. 135825 and the like.

These various additives may be added not only to the photosensitive layer but also to non-photosensitive layers such as an intermediate layer, a protective layer or a backing layer.

The heat-developable photosensitive material of the present invention contains (al photosensitive silver halide, (b) a reducing agent, (C) a binder, and (d) the coupler of the present invention. If necessary, (e) organic silver is also contained. Basically, they may be contained in one heat-developable photosensitive layer, but they do not necessarily need to be contained in a single photographic constituent layer. For example, they may be contained in two heat-developable photosensitive layers. Divide into layers, (a) and (b) above.

Components (C) and (e) are contained in one heat-developable photosensitive layer, and the coupler (d) is contained in the other layer adjacent to this photosensitive layer.
) may be contained, or may be contained in two or more constituent layers as long as they are in a state where they can react with each other.

Further, the heat-developable photosensitive layer may be divided into two or more layers: a low-sensitivity layer and a high-sensitivity layer, a high-density layer and a low-density layer, or more.

The heat-developable photosensitive material of the present invention has one or more heat-developable photosensitive layers. In the case of full-color photosensitive materials,
Generally, it has three heat-developable photosensitive layers with different color sensitivities, and in each photosensitive layer, dyes with different hues are formed or released by heat development.

Usually, a yellow dye is used in the blue-sensitive layer, a magenta dye is used in the green-sensitive layer, and a cyan dye is used in the red-sensitive layer, but the combination is not limited thereto. It is also possible to combine a near-infrared sensitive layer.

The structure of each layer can be arbitrarily selected depending on the purpose. For example, a structure in which a red-sensitive layer, a green-sensitive layer, and a blue-sensitive layer are sequentially formed on a support, or a blue-sensitive layer is sequentially formed on a support. , a green-sensitive layer, a red-sensitive layer, or a green-sensitive layer, a red-sensitive layer, and a blue-sensitive layer sequentially on the support.

In addition to the heat-developable photosensitive layer, the heat-developable photosensitive material of the present invention may optionally include non-photosensitive layers such as an undercoat layer, an intermediate layer, a protective layer, a filter layer, a backing layer, and a release layer. . To coat the heat-developable photosensitive layer and these non-photosensitive layers on the support, a method similar to that used for coating and preparing general silver halide photosensitive materials can be applied.

The heat-developable photosensitive material of the present invention can be exposed to light using an appropriate light source, and examples of the exposure light source include a tungsten lamp,
Various types such as halogen lamps, xenon lamps, mercury lamps, cathode ray tube flying spots, light emitting diodes, lasers (e.g. gas lasers, YAG lasers, dye lasers, semiconductor lasers, etc.), CRT light sources, and FOT can be used singly or in combination. It can be used as Semiconductor laser and second harmonic generating element (SHG element)
etc. can also be used. In addition, electron beams, X-rays,
Exposure may be performed using light emitted from a phosphor excited by T-rays, α-rays, or the like. Exposure times include not only exposure times of 1/1000 seconds to 1 second that are normally used with cameras, but also exposures shorter than 1/1000 seconds, such as exposures of 1/10 to 1/10" seconds using xenon flash lamps and cathode ray tubes. If necessary, the spectral composition of the light used for exposure can be adjusted with a color filter.The light-sensitive material of the present invention can be used for scanner exposure using a laser or the like.

The heat-developable photosensitive material of the present invention usually preferably has a
Development can be carried out by simply heating at a temperature range of 0° C. to 200° C., more preferably 100° C. to 170° C., preferably 1 second to 180 seconds, more preferably 1.5 seconds to 120 seconds. Transfer of the diffusible dye to the image-receiving layer may be carried out simultaneously with heat development by bringing the image-receiving member into close contact with the photosensitive surface of the photosensitive material and the image-receiving layer during heat development, or by bringing the image-receiving member into close contact with the image-receiving member after heat development. Alternatively, the transfer may be carried out by supplying water and then applying heat if necessary. Moreover, you may perform preheating in the temperature range of 70 degreeC - 180 degreeC before exposure. Also, JP-A-60-143
As described in No. 338 and No. 61-162041, the photosensitive material and the image receiving member may be preheated at a temperature of 80°C to 250°C immediately before thermal development transfer to improve mutual adhesion. good.

Various heating means can be used for the heat-developable photosensitive material of the present invention.

As the heating means, any method that can be applied to ordinary heat-developable photosensitive materials can be used, such as contacting with a heated block or plate, contacting with a heated roller or drum, or passing through a high-temperature atmosphere. Alternatively, high-frequency heating may be used, or furthermore, a conductive layer containing a conductive substance such as carbon black may be provided on the back surface of the photosensitive material of the present invention or the back surface of the image receiving member for thermal transfer, and the Joule heat generated by energization may be utilized. You can also do that. There are no particular restrictions on the heating pattern, such as preheating (breheating) and then reheating, or heating at a high temperature for a short time or at a low temperature for a long time, or by continuously increasing the temperature. , lowering the temperature continuously, or repeating these steps. Furthermore, discontinuous heating is also possible, but a simple pattern is preferable. Alternatively, a method in which exposure and heating proceed simultaneously may be used.

The heat-developable photosensitive material of the present invention is preferably provided with a protective layer.

Various additives used in the photographic field can be used in the protective layer. The additives include various matting agents, colloidal silica, slipping agents, organic fluoro compounds (especially fluorine surfactants), antistatic agents, ultraviolet absorbers,
High-boiling organic solvents, antioxidants, hydroquinone derivatives,
Polymer latex, surfactants (including polymeric surfactants), hardeners (including polymeric hardeners), organic silver salt particles, non-photosensitive silver halide particles, antifoggants, development accelerators, etc. can be mentioned.

Regarding these additives, please refer to RD (Research Disclosure Magazine) Vol. 170. June 1978 N [
No. 117029 and JP-A-62-135825.

〔Example〕

An embodiment of the present invention will be described below. However, it goes without saying that the present invention is not limited to the examples.

Example 1 A silver iodobromide emulsion, a dispersion of an organic silver salt and a thermal solvent, a dye-providing substance dispersion, and a reducing agent dispersion were prepared in the following manner.

In this example, first, using these, a photosensitive material sample Nα
1 was created. An image receiving member was also created. The amounts added are shown per photosensitive material and image receiving member unless otherwise specified (the same applies in each table).

■ Preparation of silver iodobromide emulsion 50''C, JP-A No. 57-92523, No. 57
Using the mixing agitator shown in the specification of -92524,
Add 11.6 g of potassium iodide to solution (A) in which 20 g of ossein gelatin, 1000 d of distilled water, and ammonia are dissolved.
500 d of solution (B), which is an aqueous solution containing 131 g of potassium bromide, and 500 In 1 of solution (C), which is an aqueous solution containing 1 mol of silver nitrate and ammonia, were simultaneously added while keeping PAg constant. did.

The shape and size of the emulsion grains to be prepared are determined by pH, pAg and B.
Adjustment was made by controlling the addition rates of liquid and liquid C. In this way, a core emulsion with a silver iodide content of 7 mol %, regular octahedral grains, and an average grain size of 0.25 μm was prepared.

Next, a core/shell type silver halide emulsion with a regular octahedron and an average grain size of 0.3 μm was prepared by coating a silver halide shell with a silver iodide content of 1 mol % in the same manner as above. (monodispersity was 9%). The emulsion thus prepared was washed with water and desalted.

■Preparation of photosensitive silver halide dispersion The following components were added to the silver iodobromide emulsion 7007d prepared as described above, and chemical sensitization and spectral sensitization were carried out to obtain red, green, and blue sensitivity. Each photosensitive silver halide emulsion dispersion was prepared.

(a) Preparation of red-sensitive silver iodobromide emulsion The above silver iodobromide emulsion 700 d4-hydroxy-6-methyl-1,3,3a, 7 tetrazaindengelatin sodium thiosulfate The following sensitizing dye (a) Medistillation Water sensitizing dye (a) 0.4 g 2 g 0 mg 1% tanol solution 0 ml 1200 ml (b) Preparation of green-sensitive silver iodobromide emulsion Said silver iodobromide emulsion 700 1n14-
Hydroxy-6-methyl-1,3,3a, 7-tetrazaindene 0.4g gelatin
32 g Sodium thiosulfate 10 ■ Sensitizing dye (b) below 1% methanol solution 80 Naturally distilled water 1200 d (d
) Preparation of infrared-sensitive silver iodobromide emulsion The above silver iodobromide emulsion 700 d4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene 0.6 g The following sensitizing dye (
d) Methanol 0.1% solution 0 d Following sensitizing dye (e) Methanol 0.05% solution 0 d Sodium thiosulfate 20 ■ Ion exchange water 1200 mii Sensitizing dye (d) Sensitizing dye (b) (C) Preparation of blue-sensitive silver iodobromide emulsion Said silver iodobromide emulsion 700 d4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene 0.4 g gelatin
32 g sodium thiosulfate
10 ■The following sensitizing dye (c) 1% methanol solution 80 Naturally distilled water 1200 d Sensitizing dye (C)
e) Preparation of silver salt dispersion 28.8 g of 5-methylbenzotriazole silver obtained by reacting 5-methylbenzotriazole silver and silver nitrate in a water-alcohol mixed solvent and poly(N-vinylpyrrolidone) 16.0 g, and 5-methylbenzotriazole 0
．． Disperse 65 g in an alumina ball mill and adjust the pH to 6.0.
It was made into 200 pieces.

■Preparation of thermal solvent dispersion 25g of the following thermal solvent-■ was dispersed in 100me of 0.5% polyvinylpyrrolidone aqueous solution using an alumina bow mill, and 1
They have 20 relatives.

Heat Solvent - (1) Preparation of Coupler Dispersion - 1 44.4 g of the above coupler (1) which is the coupler of the present invention
, and the following compound (ST-1) 0.15g, (SC
-1) 2.6g of ethyl acetate and 40ml of di(2-ethylhexyl) phthalate! Alkanol XC (manufactured by DuPont) 5% by weight aqueous solution 124
The mixture was mixed with an aqueous gelatin solution 720 containing 30.5 g of gelatin, dispersed using an ultrasonic homogenizer, and after distilling off ethyl acetate, the pH was adjusted to 6.0 and 850 d to obtain a dye-providing substance dispersion-1.

■ Preparation of reducing agent solution 20.0 g of reducing agent-1 below, 3.3 g of reducing agent-2,
The following fluorine-based surfactant-1 was dissolved in o, sog, and water, and the pH was adjusted to 6.0 to obtain a reducing agent solution of 250 In1.

Surfactant-1 ■Preparation of photosensitive material Using the organic silver salt dispersion, red-sensitive silver halide emulsion, dye-providing substance dispersion and reducing agent solution prepared above, a color photosensitive material was obtained as follows. .

That is, 0.75 g/% silver 5-methylbenztriazole, coupler (1), 2.
0g/nf, reducing agent 0.5g/rd, green-sensitive silver halide 0.25g Ag/nf, heat solvent 4.0g, above ST
-10,00675 g, 5C-10,12 g, gelatin 3.8 g, polyvinylpyrrolidone (K-30
)0.7 to prepare photosensitive material-1.

■Preparation of image-receiving material-1 The following compound (TP-1), (AC
An image-receiving material-1 was prepared by applying a layer (image-receiving layer) of polyvinyl chloride (application: 120 g/rrr) containing (MS-1) and a metal complex compound (MS-1).

(TP-1) NHC+oHz+ 0.8 g/Bo (MS-1) [Ni (NH2CH2CH2NH2)! ] ” [
(C6H5) 481 z-0,3g/bo (AC-1) HOCHzCHzSCHzCHzSCHzCHzOHO
, 2g/rrf The obtained photosensitive material was exposed to green light through a step wedge, and the image receiving material was overlaid.
Heat development was performed at 5°C for 170 seconds.

The density of the obtained yellow image was also measured using a reflection densitometer (DDA-65 manufactured by Konica Corp.).

As a result, the maximum density Dmax and minimum density Dmin shown in Table 1 below were obtained. It can be seen that a low capri image can be obtained at a sufficient maximum density.

Example-2 Couplers of the present invention shown in Table-1 or comparative couplers and silver halide shown below (the amount added is the same weight as in Example-1)
The same photosensitive materials Nα2 to Nα10 as the photosensitive material Nα1 of Example-1 were used, except that the couplers, silver halide, organic silver salts, reducing agents, and 5T-1 and 5C-1 shown in Table-1 were used. 〉 is the value when photosensitive material No. 1 is taken as 100%. The structure of coupler (B) is CH.

Coupler (A) CH3 →CHzCh" →BA)7- As shown in Table 1, according to the present invention, color images with high density and low fog can be obtained with a small amount of silver (half the amount of comparative light-sensitive materials).

Example 3 The light-sensitive materials of Examples 1 and 2 were exposed in the same manner as in Example 1, and then thermally developed at a temperature of 145°C for 60 seconds, 70 seconds, and 80 seconds, and at a temperature of 150″C. Heat development was performed for 70 seconds.

Maximum density Dmax and minimum density Dmi of the obtained image
Table 2 shows n. From the results in Table-2, photosensitive materials-1~
It can be seen that in the present invention using No. 7, the variation in image density (D max, D m1n) is small with respect to variation in processing conditions, and is not easily affected by processing variation. It is also seen that in the present invention, sufficient image density can be obtained in a short time. On the other hand, in the case of comparison using photosensitive materials -8 to 10, sufficient density could not be obtained in a short time, and it was easily affected by fluctuations in processing conditions. Although Comparative Photosensitive Material 10 has a deposition density more than twice that of each of the photosensitive materials of the present invention, sufficient image density cannot necessarily be obtained in a short time, and fogging occurs when processing conditions are set to obtain sufficient image density. It ends up being expensive.

Below is a margin table-2. Example-4 The image surface of the image (Nα1-10) obtained with the photosensitive materials (No. 1-10) of Examples-1 and 2 and the polyvinyl chloride ( Amount 10
After overlapping the polyvinyl chloride coated side of the sheet coated with g/r+() and heating it at a temperature of 130'C for 3 minutes,
When the polyvinyl chloride coated sheet was peeled off, no decrease in image density was observed in images No. 1 to 7 obtained according to the present invention, but in images No. 8 to 10 obtained with comparative light-sensitive materials, the dye was retransferred to the polyvinyl chloride coated sheet, and a decrease in image density of 30% or more was observed.

In addition, images Nα1 to 10 were measured using a xenon fade meter.
After 8 hours of light irradiation, image numbers 1 to 7 were 10 to 10.
Although only a 15% decrease in density was observed, image no.

8 to 10, a decrease in concentration of 30 to 40% was observed.

That is, it can be seen that the color images obtained according to the present invention have excellent image stability (fixing properties, light fastness).

Example-5 Example couplers (14), (17), (19), (23) of the present invention were used instead of coupler (1) of Example-1.
The same photosensitive materials-11 to 14 as in Example-1 except that
It was created. In Photosensitive Materials 12 and 13, the amount applied (coupler silver halide, organic silver salt, 5T-1, and SC-■) was 50% of that of Photosensitive Material-1.

All of these couplers are colorless and develop color when they react with the oxidized form of the reducing agent, but some of these couplers contain a moiety that provides magenta dye through chelation (for example, Coupler (17)). However, even with this, there is no desensitization due to undesirable filter effects during exposure to green light.

The obtained photosensitive material was exposed to green light through a step wedge, and then thermally developed in the same manner as in Example-1.
Color images corresponding to each coupler were obtained on image-receiving paper, which is an image-receiving material. Maximum density Dmax of the obtained image,
The minimum concentration Dmin is shown in Table-3.

Table 3 As shown in Table 3, high density, low fog color images were formed by forming images according to the present invention using the above couplers.

Further, when heat development was performed while varying the processing conditions in the same manner as in Example 3, the effect of the present invention of being less susceptible to processing fluctuations was observed.

Furthermore, image stability (fixing property,
When the light resistance) was evaluated, the effects of the present invention were recognized for all images.

Example-6 Instead of the metal complex compound MS-1 added to the image-receiving layer of the image-receiving material-1 of Example-1, the metal complex compound M shown below was used.
Image-receiving material 2.3 using S-2 and S-3 and image-receiving material-4 not adding MS-1 were prepared.

After exposing photosensitive materials-1, 6, and 9 in the same manner as in Example-1, heat development was performed in the same manner as in Example-1 using image-receiving materials-2, 3, and 4, and the maximum density D shown in Table-4 was obtained. Images of IIIax and minimum density Dmin were obtained.

S-2 S-3 [Cu (NHzCHzCHJHz) 21 [(C6
H5) 4B] zThe obtained image was evaluated for fixability in the same manner as in Example-4.0 image Na3.6.
Image 9 had poor fixability, and a decrease in density of 30% or more was observed upon retransfer; however, image 1°2 formed according to the present invention
．． 4.5 and 7.8 were only slightly retransferred, and no decrease in density was observed. That is, according to the present invention, fixing properties are improved.

Example-7 A multilayer photosensitive material having the structure shown in Table 5 was prepared.

The obtained photosensitive material was exposed to infrared light, green light, and red light through a step wedge, and thermally developed using Image Receiving Material-1 at a temperature of 150° C. for 60 seconds. Images with maximum density Dmax and fog Dmin shown in Table 6 were obtained corresponding to each exposure. Furthermore, the stability (fixability, light resistance) of the obtained image was also good. In other words, it can be seen that the effects of the present invention are exerted even on photosensitive materials having a multilayer structure.

Coupler (C) [Effects of the Invention] As described above, according to the image forming method and heat-developable color photosensitive material of the present invention, the coupler (C) has high density, low capri, and has good fixing properties and light fastness, that is, image stability. It is possible to obtain improved color images, and it is also possible to form images with small fluctuations in maximum density and fog due to fluctuations in developing conditions.Also, sufficient image density can be obtained in a short time, so thermal development is This has the effect that the time can be shortened, and the utilization efficiency of the dye formed by heat development is improved, so that it is also possible to reduce the amount of silver, coupler, etc. added.

Procedural amendment (0 legs) July lq, 1990

Claims (1)

[Scope of Claims] 1. A thermal support having a layer containing at least a photosensitive silver halide, a reducing agent, a binder, and a coupler that reacts with the oxidized form of the reducing agent to form a diffusible dye. The color light-sensitive material is heat-developed to form a diffusible dye, and the diffusible dye is transferred to an image-receiving material at the same time and/or during the heat-development, and metal ions are added to the image-receiving material. The diffusible dye is metal chelated, 400~
An image forming method characterized by forming a dye image having a maximum absorption wavelength at 700 nm. 2. A heat-developable color photosensitive material having a layer containing at least a photosensitive silver halide, a reducing agent, a binder, and a coupler that reacts with the oxidized product of the reducing agent to form a diffusible dye, the coupler and/or The reducing agent has a group selected such that the diffusible dye formed has a chelatable structure, and the maximum absorption wavelength of the dye image formed is 4.
A heat-developable color photosensitive material characterized by being a compound having a wavelength of 00 to 700 nm.