JPS59188645A - Thermodevelopable photosensitive element - Google Patents

Abstract

PURPOSE:To obtain a thermodevelopable photosensitive material capable of transferring a sharp image superior in the max. density and small in fog on an image receiving paper, by incorporating a specified dye-releasing reducing agent in the thermodevelopable photosensitive layer. CONSTITUTION:A photosensitive element is obtained by forming on a support a thermodevelopable photosensitive layer contg. an org. silver salt and a coupler, and a dye-releasing reducing agent, such as compd. represented by formula IV, capable of releasing a dye having no hydrophilic group, such as -SO2NH2, in the molecule, represented by general formula I in which X is OH or a group of formula II; R2, R3 are each alkyl or aryl; Y is an atomic group necessary to complete a benzene or naphthalene ring; a group of formula III is a thermodiffusive dye residue; and R1 is H, alkyl, or aryl. As a result, a sharp transferred image superior in the max. density and small in fog can be formed on an image receiving paper only by bringing the exposed thermodevelopable photosensitive layer into contact with the image receiving paper and heating them with an iron or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heat-developable photosensitive element, and more particularly to a heat-developable photosensitive element which has an excellent density of a transferred nine-color patch image.

5. Prior Art Color photography using photosensitive silver rhodide, which has been known in the past, is superior to other color photography methods in terms of photosensitivity, gradation, and image preservation. It has been widely put into practical use. However, in this method, wet processing is used for steps such as development, bleaching, fixing, and washing, so the processing is time-consuming and labor-intensive.1. In addition, there are many other problems, such as concerns about pollution to the human body due to treatment chemicals, concerns about contamination of treatment rooms and workers, and the labor and cost of waste liquid treatment. .

Therefore, there has been a demand for the development of a method for forming color images that allows dry processing.

Black and white heat-developable photosensitive materials characterized by heat treatment in the development process have been known for a long time), for example, as disclosed in Japanese Patent Publication No. 1973-
No. 4921 and No. 43-4924 disclose a photosensitive material comprising an organic acid iron salt, silver halide, and a developer. Furthermore, many color heat-developable photosensitive materials are also known, to which this black-and-white photothermographic material is applied.

For example, U.S. Patent Nos. 3,531,286 and 3,761
, No. 270, No. 3,764, 328, Research Disclosure
re ) (hereinafter referred to as RD) A15108 Q same A1
5127, A 12044 Oyo U A 16479
U.S. Pat. No. 3,180, et al. disclose a heat-developable photosensitive material containing a photographic coupler and a color developing agent.
No. 731, RD Bian 13443 and A 14347
etc., U.S. Patent No. 4,235,957, RD A 14433, U.S. Pat.
No. 14448, No. A 15227, No. 15776, No. A 18137, No. A19419, etc. are patented in U.S. Patent No. 4,124,
No. 398, No. 4,124,387 and No. 4,1
No. 23,273 describes heat developability and a method for thermal bleaching of optical materials.

However, with these proposals regarding color heat-developable photosensitive materials, it was difficult or impossible to bleach or fix the simultaneously formed black and white silver image, and even if it was possible, wet processing etc. were required. It is what you need. Therefore, these proposals are not found to be desirable as it is difficult to obtain clear color images and complicated post-processing is required.

RD A is a heat-developable color photosensitive material in which a color image is obtained by separating a silver image and a dye by releasing a diffusible dye through heat development and transferring this dye to an image-receiving layer. 16966, JP-A-56-5032
No. 8, JP-A-57-179840 and JP-A No. 57-18
No. 6744.

However, the image transfer step in these heat-developable color image forming methods involves a so-called solvent transfer method in which dyes are diffusely transferred together with a solvent. It also has the disadvantage that the additives may be transferred and cause image staining. Jl! The reducing dye-providing substance described in JP-A-57-179841 requires a basic compound to release the dye, and such a compound is contained in the heat-developable photosensitive element. However, there is a problem in that capri increases and the maximum density of the image decreases. Furthermore, the dye released from such a reducing dye-donor always contains 18OzNH in the molecule.
The presence of this hydrophilic substituent tends to have an unfavorable effect on image separation during solvent transfer, and dyes with the above substituents have a tendency to have sublimation properties. Due to deterioration or poor sublimation, image separation is lacking during dye transfer.

Furthermore, according to JP-A-57-186744, a dye is released using a dye-releasing coupler and a color developing agent,
A method of thermally transferring this is described, but since the dye-releasing coupler is a 2-equivalent coupler, the coupling property with the color developing agent under heat development conditions is poor, and the maximum density of the image cannot be obtained sufficiently. There is a drawback.

The present invention has been made by focusing on the above-mentioned drawbacks,
Use of a dye-releasing reducing agent that can release a dye that does not contain a hydrophilic group such as -8O2NH2 group in the molecule without using a basic compound or a divalent coupler as described above, and a heat treatment containing this agent. We have made repeated studies on developable photosensitive elements and thermal development image forming methods.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an image forming method that allows clear color images to be obtained without complicated processing, and a photosensitive element suitable for the method. 1,
The object of the present invention is to provide a method by which color images with maximum density and excellent color images can be obtained by simple processing including thermal development, and a photosensitive element suitable for the method.

Structure of the Invention As a result of various studies for the above-mentioned purpose, the inventors of the present invention have prepared, on a support, (a) an organic silver salt, (b) a coupler, and (c) a compound represented by the following general formula CI). It has been found that this is accomplished by a heat-developable photosensitive element having at least one heat-developable photosensitive layer entrained with a dye-releasing reducing agent.

In the general formula (1), R2 and R3 each represent an alkyl group or an aryl group), Y represents an atomic group necessary to complete a benzene ring or a naphthalene ring, and R1 Dye-N- represents a thermal It represents a diffusible dye residue, and R1 represents a hydrogen atom, an alkyl group, or an aryl group.

The present invention will be explained in more detail below. The dye-releasing reducing agent used in the heat-developable photosensitive layer of the heat-developable photosensitive element of the present invention is represented by the above general formula (1). The benzene ring or naphthalene ring formed by the atomic group represented by Y in general formula (1) may have a substituent, and these substituents include a carboxyl group, a sulfo group or a salt thereof, a halogen atom (preferably chlorine atom, bromine atom, iodine atom), alkyl group (preferably an alkyl group having 1 to 24 carbon atoms, such as methyl group, ethyl group, tert-butyl group, 5eC-octyl group) group, pentadecyl group, cyclohexyl group, trifluoromethyl group, benzyl group, phenethyl group, etc.), aryl group (
For example, phenyl group, naphthyl group, tolyl group, mesityl group, etc.), acyl group (for example, acetyl group, tetradecanoyl group, pivaloyl group, benzoyl group, etc.), alkyloxycarbonyl group (for example, methoxycarbonyl group, benzyloxycarbonyl group, etc.) ), aryloxycarbonyl group (e.g. phenoxycarbonyl group, -p-)υ
), alkylsulfonyl groups (e.g. tfd methylsulfonyl group, etc.), arylsulfonyl groups (e.g. phenylsulfonyl group), carbamoyl groups (e.g. methylcarba7yl group) , butylcarbamoyl group, tetradecylcarbamoyl group, N-methyl-N-dodecylcarbamoyl group, phenylcarbamoyl group, etc.), acylamino group -
methoxyacetamide group, etc.), alkoxy group (preferably an alkoxy group having 1 to 18 carbon atoms, such as methoxy group, ethoxy group, octadecyloxy group, etc.)
, sulfamoyl group (e.g. methylsulfamoyl group 1
．． , phenylsulfamoyl group, etc.), sulfamino group (e.g., methylsulfamino, tolylsulfamino)
, nitro group, hydroxy group, etc. At least one of these substituents is preferably a ballast group having a molecular size and/or shape sufficient to provide thermal non-diffusivity to the dye-releasing reducing agent according to the present invention. .

The alkyl group contained in R1 is preferably an optionally substituted lower alkyl group, and S is a methyl group,
There are 75 ethyl groups, methoxymethyl groups, etc. Furthermore, R1
As the aryl group represented by, a phenyl group is preferable.

Preferred are lower alkyl groups such as methyl, ethyl, n-propyl, n-phetyl, methoxyethyl and the like. Further, the aryl group represented by R2 and R3 may have a substituent group, and preferred examples include phenyl group and tolyl group. The groups represented by R2 and R3 may be substituted with a nolast group.

In the present invention, the above-mentioned (last group) is particularly preferably a group having 12 or more carbon atoms, and/or a hydrophilic group derived from acids such as sulfonic acid, carboxylic acid, and sulfinic acid, and their salts. There are sexual substituents.

The heat-developable photosensitive layer of the heat-developable photosensitive element of the present invention may contain a coupler. As the coupler in the present invention, “11
A wide variety of materials can be used as long as they can undergo a coupling reaction with the oxidized product of the dye-releasing reducing agent represented by the general formula (1). Couplers preferably used in the present invention are:
It can be represented by the following general formulas (l]) to (■).

General formula (II) 5 General formula (in) General formula (IV) R+r -CHCOR9 IO General formula (V) General formula (M) General formula (■) 19 In the formula, ZI″i is defined in the above general formula (1) Sureda Y
is a group synonymous with R4, R6, R8, R9, RI2,
R14, Rlcr, R17, R111 and R2O are each a hydrogen atom, a halogen atom (preferably a chlorine atom,
bromine atom, iodine atom), argyl group (preferably an alkyl group having 1 to 24 carbon atoms, such as methyl, ethyl,
butyl, t-octyl, n-dodecyl, n-pentadecyl, cyclohexyl, etc.), aryl groups (substituents may be present, such as phenyl, naphthyl, tolyl, mesityl groups) ), an alkoxy group (preferably an alkoxy group having 1 to 18 carbon atoms, such as a methoxy group, an ethoxy group, an occudecyloxy group), an aryloxy group (such as an enyloxy group), an aralkyl group (
For example, benzyl group, phenethyl group), acyl group (for example, acetyl group, tetradecanoyl group, pivaloyl group, benzoyl group), acylamino group (for example, n-butylamide group, optionally substituted benzamide group, methanesulfonamidoethylamide group) group, β-methoxyethylamide group), alkoxyalkyl group (methoxymethyl group, ethoxypentyl group), aryloxyalkyl group (phenoxymethyl group), N-substituted carbamoyl group (e.g. methylcarbamoyl group, butylcarbamoyl group, tetricarbamoyl group), decylcarbamoyl group, N-methyl-N-dodecylcarbamoyl group, 2.4-sheet t-phenoxybutylcarbamoyl group, 2-dodecyloxyphenylcarbamoyl group),
Alkylamino group (e.g. methylamine group, butylamino group, octylamino group), acyloxy group (e.g. acetyloxy group, benzoyloxy group), acyloxyalkyl group (e.g. acetyloxymethyl group, benzoyloxypropyl group) , cyan group, nitro group, etc.

Further, R11 represents an electron-withdrawing substituent, preferably an acetyl group, a benzoyl group, or a cyan group; R5, R7,
R11l, R13, R16 and 几19 represent a group or a hydrogen atom that can be separated from the coupler residue by a coupling reaction, and preferably On and m are hydrogen atoms.
is an integer of 1 to 3, and when n and m are plural, R8 and R1□ may be the same or different from each other.

Next, typical examples of couplers having the above general formulas (n) to (■) will be shown, but the present invention is not limited thereto.

(ψ coupler) -2 H -4 -7- 0 The dye-releasing reducing agent according to the present invention represented by the above general formula (1) is one that releases a dye upon oxidation, heating, and coupling reaction. Conceivable. Usually, the dye-releasing reducing agent itself also serves as a developing agent and is oxidized during silver development, or
When another developing agent is added, it is oxidized to an oxidized form of the developing agent that is oxidized during silver development. The dye released during oxidation is diffused into the image-receiving layer by heat, forming a transferred image. At this time, the dye-releasing reducing agent according to the present invention is non-diffusive to heat, and no dye is transferred to unexposed areas. The thermal transfer of the dye released as described above may be a transfer that involves melting or melting, but from the viewpoint of image separation and high sharpness, it is preferable to use a sublimable dye. Further, it is preferable that at least part or all of the thermal transfer step is transfer by sublimation. The sublimation of sublimable dyes refers to the fact that they are solid at room temperature, but not only do they vaporize directly with appropriate heating, but they also melt once and become liquid, which is the final state. This also includes the property of vaporization, and the present invention preferably includes those in which the emitted dye undergoes vaporization transfer based on the above-mentioned property.

In the present invention, the dyes released from the dye-releasing reducing agent represented by the general formula (1) include azo dyes, azomethine dyes, anthraquinone dyes, triphenylmethane dyes, nitro dyes, indigoid dyes, phthalocyanine dyes, and quinoline dyes. , xanthine dyes, etc. can be used, but preferably a dye having a sublimation temperature of 80° to 250°C, more preferably 100° to 200°C.

Examples of the heat-diffusible dyes used in the present invention include the following.

(Exemplary dye) DYe' -(1) Dye -(2)D
ye ・−(3) Dye −(
4) Dye (5) Dye
-(6)Dye -(7)Dy
e −(8) CH3CC=CCHs 1 Dye −(9) Dye−αQD
ye-α sword Dye-(6) Dye-
αI Dye-α◆As a preferable dye to be released in the present invention, the following general formula (■
) and (IX) which can be chelated (post-chelate dyes). Particularly preferred are sublimable dyes that can be chelated, and in the case of using the above-mentioned chelatable dyes in the present invention, polyvalent metal ions (preferably nickel) are provided in the image receiving area.
n), II (II), Kobal) (II), Palladium (
A stable chelated image can be obtained in the first region of the receiver by containing the ingredients (II) and zinc, etc.).

General formula (■I) In the formula, A' represents an atomic group necessary to form an aromatic ring or a heterocycle in which at least one ring is composed of a 5- to 7-membered ring, and is bonded to an azo bond. At least one adjacent position of a carbon atom is (a) a nitrogen atom, or (b) a carbon atom substituted with a nitrogen atom, an oxygen atom, or a sulfur atom, and A2 is a carbon atom in which at least one ring is 5-7 Represents a group of atoms that are not necessary to complete an aromatic ring or a '4i elementary ring composed of a negative ring.

G represents a chelating group, and at least one amine group (primary or secondary amine group).

General formula (IX) z+ H In the formula, A3 is a group having the same meaning as AI in the above general formula (■) Zl is an electron-withdrawing group, preferably an acetyl group,
Benzoyl group, cyanogen group or carbamoyl group (including alkylcarbamoyl group or arylcarbamoyl group)
Z2 represents an alkyl group (preferably a methyl group) or an aryl group (preferably a phenyl group), and at least one amine group (including a chelating group) as a substituent on the ring (including a 13th amino group). , secondary amino group) are substituted.

Typical specific examples of chelatable dyes (bost chelate dyes) represented by general formulas (■) and (IX) are described below.

(Exemplary dye) Dye-α■ Dye-αQDye (1
71Dye = <IQDye-(2) D
ye-(E)D)'e -HDye-(I) Dye-翰 0Next, typical specific examples of the dye-releasing reducing agent represented by the general formula (I) capable of releasing the above-mentioned diffusible dye will be described. (Exemplary compounds) CPM -4 CPM -7 C2H5C2H3 CPffi,'I -8 CPM-9 CPM-10 CPM -13 C2H5〉CHz )3SO3H C2('''CCH2)ssOsH CPn,'r-16 C21d\(Cl -12)3SO3H The dye-releasing reducing agent described above can generally be produced by separately synthesizing the reducing agent part and the dye part, and then chemically bonding the two parts.

Below, a method for synthesizing the dye-releasing reducing agent according to the present invention will be described.

Synthesis Example 1 (Synthesis of Exemplary Compound CPM-1) 3.77 of the dye shown below was mixed with 2.149 of P-N,N-diethylaminophenylamine at 100 m/! of pyridine and stirred at room temperature for 5 hours, then stirred for an additional 30 minutes at 60~
After heating to 70° C. and cooling, it was added to 10% brine containing 507 ice, and the resulting solid was collected by filtration. This solid was isolated and purified by column chromatography to obtain the desired product 4.22. In addition, the synthesized compounds are NM・RlIR, FD-
This was confirmed by mass spectra, etc.

Hs After exposure, the heat-developable photosensitive element containing the dye-releasing reducing agent according to the present invention obtained by the above-mentioned synthesis method can be easily processed by simply bringing it into close contact with an image-receiving paper and heating it with, for example, an iron. , a clear transferred image with excellent maximum density and less capri can be obtained on image-receiving paper.Hereinafter, the heat-developable photosensitive element of the present invention will be described in detail.

In the heat-developable photosensitive element of the present invention, the heat-developable photosensitive layer is impregnated with an organic silver salt as a photosensitive function 2 and a developable function.

In the present invention, the photosensitivity function and the developability function are obtained by the organic silver salt.In terms of photosensitivity, although the organic silver salt itself has photosensitivity, it is necessary to catalytically contact it with the silver salt. The sensitivity is further improved by using silver halide.
It is possible to improve this by spectral sensitization. However, in the present invention, in which a color image is transferred and separated from a silver image, improving the image quality by adding an anti-halation or irradiation dye is not possible, but rather effective.

In terms of developability, it is also advantageous in that it is easy to relate the dissolution physical image reaction of the organic silver salt that occurs upon heating to the dye release reaction of the dye release reducing agent. That is, in the present invention, by properly setting the commonly understood physical development reaction of organic silver salt, the reaction that releases the dye using it, and the conditions for thermal transfer, it is possible to perform heating (thermal development) only once. This makes it possible to obtain clear color transfer images.

Heat-developable photosensitive elements generally form images only by heat development;
Due to the specificity of not applying a fixing process, a well-known drawback is image deterioration due to printout. Therefore, conventional photothermographic elements have the trouble of having to be kept in a cool, dark place after image formation. In the present invention, even if the photosensitive layer is exposed and printout occurs, the effect of this on the dye release reaction and furthermore on the transfer thereof is extremely small. If a method of peeling off the photosensitive layer and the image-receiving layer is employed, little problem arises.

The heat-developable photosensitive element used in the present invention is basically the same as the heat-developable photolayer I. (4) Although a binder is present, the above-mentioned organic silver base and photosensitive silver halide may be contained in the same layer, and the dye-releasing reducing agent according to the present invention may be contained in this layer and an adjacent layer.

As the organic silver salt used in the present invention,
No. 3-4924, No. 44-26582, No. 45-184
No. 16, No. 45-12700, No. 45-22185, and No. 49-52626, No. 52-31728, No. 52-13731, No. 52-141222, No. 53-36224, No. 53- 37610 Publications 1 U.S. Patent Nos. 3,330.633 and 4,168,980
Silver salts of aliphatic carboxylic acids such as silver laurate, silver myristate, silver balmitate, silver stearate, silver arachidonic acid, silver behenate, etc., as described in the specifications of No.
Also, aromatic silver carboxylates such as silver benzoate, silver fucurate, etc., silver salts having an imino group, such as silver benztriazole, silver saccharin, silver phthalazinone, silver phthalimide, etc., and silver salts of compounds having a mercapto group or a thione group. For example, 2-mercaptobenz-oxazole silver, mercaptooxadiazole silver, mercaptobenzthiazole silver,
2-mercaptobenzimidazole silver, 3-mercapto-phenyl-1,2,4-triazole silver, and also 4-hydroxy-6-methyl-1,3,3a, 7
- Citrazaindene silver, 5-methyl-7-hydroxy-
Examples include 1,2,3°4.6-Henkseinden silver. It is also possible to use silver compounds such as those described in RD 16966, RD 16907, and British Patent Nos. 1,590,956 and 1,590,957. Among these, silver salts having an imino group such as penztriazole silver salts are preferred as silver salts of benztriazole.
Alkyl-substituted benztriazole silver such as methylbenztriazole silver, e.g. bromo-penztriazole silver, halogen-substituted benztriazole silver such as chlorbenztriazole silver, amide-substituted benztriazole silver such as 5-acetamidobenztriazole silver, Also, British Patent No. 1゜590.956,
Compounds described in each specification of No. 590,957, such as N-
[6-chloro-4-N(3,5-dichloro-4-hydroxyphenyl)imino-1-oxo-5-methyl-2,
5-Cyclohexadien-2-yl]-5-carbamoylbenztriazole silver salt, 2-penztriazole-
5-ylazo-4-methoxy-1-naphthol silver background, 1
-penztriazol-5-ylazo-2-naphthol silver background, N-penztriazol-5-yl-4-(4-
Examples include dimethylaminophenylazo)benzamide silver salt.

In addition, nitrobenztriazoles represented by the following general formula (X) and general formula (
X) In the formula, R21 represents a nitro group, and R22 and R23 may be the same or different, and each represents a rhodane atom (for example, each atom such as chlorine, bromine, or iodine), a hydroxyl group, or a sulfonate group. groups or salts thereof (e.g., sodium salts, potassium salts, ammonium salts), carboxy groups or salts thereof (e.g., sodium salts, potassium salts, ammonium salts), nitro groups, cyano groups, each of which has a substituent. optional carbamoyl group, sulfamoyl group, alkyl group (e.g., methyl group, ethyl group, propyl group),
It represents an alkoxy group (for example, a methoxy group, an ethoxy group), an aryl group (for example, a phenyl group), or an amine group, p represents an integer of 0 to 2, and q represents an integer of θ to 1. Further, as substituents for the carbamoyl group (d), for example, methyl group, ethyl group, acetyl group, etc. can be mentioned, and as substituents for the sulfamoyl group, for example, methyl group, ethyl group, acetyl group, etc. can be mentioned, and alkyl Examples of substituents for groups include carboxy groups and ethoxycarbonyl groups, examples of substituents for aryl groups include sulfo groups and nitro groups, and examples of substituents for alkoxy groups include carboxy groups and ethoxycarbonyl groups, and Examples of substituents for the amine group include an acetyl group, a methanesulfonyl group, and a hydroxy group.

The compound represented by the general formula (X) is a silver salt of a benzotriazole rust conductor having at least one nitro group, and specific examples thereof include the following compounds.

For example, silver 4-nitrobenzotriazole, silver 5-nitrobenzotriazole, silver 5-nitro-6-chloropenzotriazole, silver 5-nitro-6-methylbenzotriazole, silver 5-nitro-6-methylbenzotriazole, -nitro-7-phenylbenzotriazole silver,
4-Hydroxy-7-nitrobenzotriazole silver, 4-hydroxy-5,7-sinitrobenzotriazole silver, 4-hydroxy-5-nitro-6-chlorobenzotriazole silver, 4-hydroxy-5-2) r:l-
6-Methylbenzotriazole silver, 4-sulfo-6-nitrobenzotriazole silver, 4-carboxy-6-nitrobenzotriazole silver, 5-carboxy-6-nitrobenzotriazole silver, 4-carbamoyl-6-nitrobenzotriazole silver , 4-sulfamoyl-6-nitrobenzotriazole silver, 5-carboxymethyl-6-
Silver nitrobenzotriazole, Silver 5-hydroxycarbonylmethoxy-6-nitrobenzotriazole, Silver 5-nitro-7-diatubenzotriazole, 5-amino-
6-nitrobenzotriazole silver, 5-nitro-7-(
p-nitrophenyl)benzotriazole silver, 5.7-
Dinitro-6-methylbenzotriazole silver, 5.7-
Dinitro-6-chlorobensotriazole silver, 5,7-
Examples include silver dinitro-6-methoxybenzotriazole.

General formula CM) In the formula, R24 is a hydroxy group, a sulfo group or a salt thereof (e.g., sodium salt, potassium salt, ammonium salt), a carboxy group or a salt thereof (e.g., sodium salt, potassium salt, ammonium salt), or a substituted R25 represents a carbamoyl group which may have a group and a sulfamoyl group which may have a substituent, and R25 is a halogen atom (e.g. chlorine, bromine, iodine), a hydroxy group, a sulfo group or a salt thereof (e.g. 1 sodium salt, potassium salt, ammonium salt), carboxy group or its salt (e.g.
Sodium salt, potassium salt, ammonium salt L=)o
4, a cyano group, or 5 an alkyl group (e.g., methyl group, ethyl group, propyl group), which may each have a substituent, an aryl group (e.g., phenyl group), an alkoxy group (e.g., methoxy group, ethoxy group) ) or an amine group, r is 1'' or 2, and S is an integer of 0 to 2.

Examples of substituents for the carbamoyl group in R24 include methyl, ethyl, acetyl, etc., and examples of substituents for sulfamoyl include methyl, ethyl, acetyl, etc. can. Furthermore, examples of substituents for the alkyl group in R25 include a carboxyl group, an ethoxycarbonyl group, etc.
Examples of substituents for aryl groups include sulfo groups and nitro groups; examples of substituents for alkoxy groups include carboxy groups and ethoxycarbonyl groups; and examples of substituents for amine groups include acetyl groups, methanesulfonyl groups, and hydroxyl groups. Each of the groups can be mentioned.

Specific examples of the organic silver salt represented by the general formula (Xi) include the following compounds.

For example, silver 4-hydroxybenzotriazole, silver 5-hydroxybenzotriazole, silver 4-sulfopensotriazole, silver 5-sulfobenzo), silver IJ azole, silver sodium benzotriazole-4-sulfonate, silver silver benzotriazole-5-sulfone. Sodium, silver benzotriazole-4-potassium sulfonate, silver benzotriazole-5-potassium sulfonate, silver benzotriazole-4-ammonium sulfonate, silver benzotriazole-5-ammonium sulfonate, silver 4-carboxybenzotriazole, 5 -Carboxybenzotriazole silver, benzotriazole s! Sodium -4-carboxylate, silver benzotriazole-5-sodium carboxylate, silver benzotriazole-4-potassium carboxylate, silver benzotriazole-5-potassium carboxylate, silver benzotriazole-4-carboxylate ammonium, silver benzotriazole -5-ammonium carboxylate, 5
- Silver sulfamoylbenzotriazole, silver 4-sulfamoylbenzotriazole, silver 5-hydroxy-6-hydroxybenzotriazole, silver 5-carboxy-7-sulfobenzotriazole, silver 4-hydroxy-5-sulfobenzotriazole Sol silver, 4-hydroxy-7-sulfobenzotriazole silver, 5,6-dicarboxybenzotriazole silver, 4,6-cyhydroxybenzotriazole silver, 4-hydroxy-5-chlorobenzotriazole silver, 4-hydroxy-5 -Methylbenzotriazole silver, 4-hydroxy-5-methoxybenzotriazole silver, 4-hydroxy-5-nitrobenzotriazole silver,
4-Hydroxy-5-cyanobenzotriazole silver, 4
-Hydroxy-5-aminobenzotriazole silver, 4-
Hydroxy-5-acetamidobenzotriazole silver,
4-Hydroquine-5-benzenesulfonamide benzotriazole silver, 4-hydroxy-5-hydroxycarbonylmethoxybenzotriazole silver, 4-hydroxy-
5-ethoxycarbonylmethoxybenzotriazole silver, 4-hydroxy-5-carboxymethylbenzotriazole silver, 4-hydroxy-5-ethoxycarbonylmethylbenzotriazole silver, 4-hydroxy-5-phenylbenzotriazole silver, 4-hydroxy-5 −(p
-nitrophenyl)benzotriazole 5M, 4-hij
IJ azole silver, 4-sulfo-5-methylbenzotriazole silver,
4-Sulfo-5-me) xybenztriazole silver, 4
-sulfo-5-cyanobenzotriazole silver, 4-sulfo-5-aminobenzotriazole silver, 4-sulfo-5
-acetamidobenzotriazole silver, 4-sulfo-5
-benzenesulfonamidobenztriazole silver, 4-
Sulfo-5-hydroxycarbonylmethoxybenzotriazole silver, 4-sulfo-5-ethoxycarbonylmethoxybenzotriazole silver, 4-hydroxy-5-carboxybenzotriazole silver, 4-sulfo-5-carboxymethylbenzotriazole silver, 4-sulfo -5-ethoxycarbonylmethylbenzotriazole silver, 4-sulfo-5-phenylbenzotriazole silver, 4-su #$
-5-(p-nitrophenyl)benzotriazole silver,
4-Sulfo-5-(p-sulfophenyl)benzotriazole silver, 4-sulfo-5-methoxy-6-chlorobenzotriazole silver, 4-sulfo-5-chloro-6-carboxybenzotriazole silver, 4-carboxy- 5-chlorobenzotriazole silver, 4-carboxy-5-methylbenzotriazole silver, 4-carboxy-5-nitrobenzotriazole silver, 4-carboxy-5-aminobenzotriazole silver, 4-carboxy-5-methoxybenzotriazole silver , 4-carboxy-5-acetamidobenzotriazole silver, 4-carboxy-5-ethoxycarbonylmethoxybenzotriazole silver, 4-carboxy-5-carboxymethylbenzo) IJ azole silver, 4'-carboxy-5-phenylbenzotriazole silver , 4-carboxy-5-(p-nitrophenyl)benzotriazole silver, 4-carboxy-5-methyl-7
- Sulfobenzotriazole silver, etc. can be mentioned. These compounds may be used alone or in combination of two or more.

The organic @salt that can be used in the present invention may be isolated and used by dispersing it in a binder by appropriate means, or the silver salt may be prepared in a suitable binder and not isolated. It may be used as is.

The amount of the organic silver salt used is 1 m vortex of the support. l) 0.0
59-10.09, preferably 0.22-2. O
It is f.

When the heat-developable photosensitive layer used in the present invention contains photosensitive silver halide, examples of the photosensitive silver halide include silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, Silver iodobromide, silver chloroiodobromide, or a mixture thereof can be used. The photosensitive silver halide can be prepared by any method known in the photographic field, such as a single jet method or a double jet method, but in particular, a photosensitive silver halide prepared according to a commonly used method for preparing silver halide gelatin emulsions. Polymer silver halide emulsions give favorable results.

The light-sensitive silver halide emulsion may be chemically sensitized by any method known in the photographic art. Such sensitization methods include gold sensitization, sulfur sensitization, gold sensitization, and silver rhodanide in the above-mentioned photosensitive emulsion, which may be coarse or fine grains, but the preferred grain size is determined by its diameter. is about 1.5μ to about 0
．． 001μ, more preferably about 0.5μ to about 0
．． It is 01μ.

Furthermore, as another method for preparing photosensitive silver halide, a photosensitive silver salt-forming component can be allowed to coexist with an organic silver salt, and photosensitive silver halide can be formed in a part of the organic silver salt. The photosensitive silver salt-forming component used in this preparation method is an inorganic halide, for example, a halide represented by MX (where M represents an H atom, an NH4 group, or a metal atom,
X is C11Bri is 1. n indicates 1 when M is an H atom or an NH4 group, and indicates the valence when M is a metal atom. The metal atoms include lithium, sodium, potassium, rubidium, cesium, copper, gold, beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, aluminum, indium, lanthanum, ruthenium, thallium, germanium, -1 Examples include lead, antimony, bismuth, chromium, morinden, tungsten, manganese, rhenium, iron, cobalt, nickel, rhodium, palladium, osmium, iridium, platinum, and cerium. ), halogen-containing metal complexes [e.g. KaP t C16, KsP t B rs , HA
uCl4, (NH4)2IrCA6, (NL) 3'
I rC16, (NH4)3Ru C4, (NH4)
3RuC46, (NH4)3 Rh CAs, (NH4
)s RhBr(, etc.), onium halides (e.g. quaternary ammonium halides such as tetramethylammoniumfuromite, trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, 3-methylthiazolium bromide, trimethylbenzylammonium bromide, Quaternary phosphonium halides such as tetratylphosphonium bromide, tertiary sulfonium halides such as benzylethylmethyl bromide, 1-ethylthiazolium bromide, etc.), halogenated hydrocarbons (e.g. iodoform, bromoform 1m bromide, etc.) carbon, 2-bromo-2-methylpropane, etc.), N-halogen compounds (N-chlorosuccinimide, N-bromosuccinimide, N-bromphthalimide, N-bromoacetamide, N-iodosuccinimide, N-bromo phthalazinone, N-chloro7thalazinone, N-bromoacetanilide, N,N-dibromobenzenesulfonamide, N-promo N-methylbenzenesulfonamide, 1゜3-dibromo-4,4-dimethylhydantoin, etc.), and others. halogen-containing compounds (e.g. triphenylmethyl chloride, triphenylmethyl bromide, 2
-bromobutyric acid, 2-bromoethanol, etc.).

These photosensitive silver rhodanide and photosensitive silver salt forming components can be used in combination in various methods, and the amount used is 0.001 to 5.0 mol per 1 mol of the organic silver salt.
Preferably it is 0.01 to 0.3 mol.

The photosensitive silver halide emulsion used in the heat-developable photosensitive element of the present invention can be obtained by adding various spectral sensitizing dyes to the above-mentioned silver halide emulsion.

Spectral sensitizers that can be used in the heat-developable photosensitive element of the present invention include, for example, JP-A-49-84637;
-96717, 4 (1-102328, 49-
No. 105524, No. 50-2924, No. 50-290
29 (+ issue, 50-704637, 50-105
No. 127, No. 51-27924, No. 52-80829
Nos. Publications 1 British Patent No. 1,467.638, US Pat. No. 4,173,478 Specifications There are those described in Rose et al.

The dye-releasing reducing agent represented by the general formula (1) can itself serve as a developing agent for silver development, but another reducing agent (developing agent) may also be used in the heat-developable photosensitive element of the present invention. May be added. In this case, the dye-releasing reducing agent is mainly cross-oxidized by the oxidized form of the developing agent.

Examples of the reducing agent (developing agent) that can be added to the heat-developable photosensitive element of the present invention include US Pat. No. 3,667.958;
JP-A No. 3,670,426, JP-A-47-1238, JP-A No. 46-6074, JP-A No. 46-6590, JP-A No. 47-18
No. 41, No. 47-10282, U.S. Patent No. 3,782
, 949, UK Patent No. 780,616, US Patent No. 3.
751249, British Patent No. 786086, British Patent No. 785
958, U.S. Patent No. 3.751252, Cir. 3.751
, 255 @, West German Patent No. 2,308,766, Belgian Patent No. 8000111, U.S. Patent No. 3,801,32
1-F4, No. 3,794,488, Japanese Unexamined Patent Publication No. 50-15
No. 541, U.S. Patent No. 3,893,863, JP-A No. 5
No. 0-36110, No. 50-147711, No. 51-
No. 23721, No. 51-32324, No. 51-519
No. 33, No. 52-84727, Special Publication No. 45-2218
No. 5, all the developers described in each publication 1 can be used,
Specifically, it is possible to use a reducing agent as described below.

i.e. thiphenols (e.g. p-phenylphenol,
p-methoxyphenol, 2,6-jert-butyl-p-cresol, N-methyl-p-aminephenol, etc.), sulfonamide 7-ethers (e.g. 4-benzenesulfonamidophenol, 2I6-dichloro) -4-benzenesulfonamidophenol, 2.6-dipromo-4-(P-)luenesulfonamido)phenol, etc.), or polyhydroxybenzenes (for example), hydroquinone, tert-pternohydroquinone, 2,6-dimethylphenol, etc. Tsutahydroquinone, chloronohydroquinone, carboxyhydroquinone, catechol, 3-carboxycabucol, etc.), naphthols (e.g. α-naphthol, β-naphthol, 4
-aminonaphthol, 4-methoxynaphthol, etc.), hydroxybinaphthyls and methylene bisnaphthol M
[The file is 1,1'-dihydroxy-2,2'-
Binaphthyl, 6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl, 6,6'-dinitro-2
, 2'-dihydroxy-1,1'-binaphthyl, 4,4
'-dimethoxy-1,1'-dihyto90xy2,2'
-binaphthyl, bis(2-hydroxy-1-naphthyl)
methane etc.], methylene bisphenols [e.g. 1.
1'-bis(2-hydroxy-3,5-dimethylphenyl) - 3. 5. 5-trimethylhexane, 1
．． 1-bis(2-hydroxy-3-tert − )
f-5-methylphenyl)methane, 1,1-bis(2
-hydroxy-3,5-di-tert-butylphenyl)methane, 2,6-methylenebis(2-hydroxy-3
- tert-butyl-5-methylphenyl)-4-
Methylphenol, α-phenyl-α,α-bis(2-
Hydroxy-3,5-di-tert-butylphenyl)methane, α-phenyl-α,α-bis(2-hydroxy-3-tert-butyl-5-methylphenyl)methane, 1,1-bis(2-hydroxy -3,5-dimethylphenyl)-2-methylcross, 1, 1,
5. 5-tetrakis(2-hydrocytate 3, s
- Dimethylphenyl 4-ethylpentane, 2,2-bis(4-human0roxy3.5-dimethylphenyl)
Cross-kun, 2,2-bis(4-hydroxy-3-methyl-5-tert-butylphenyl) Cross-kun, 2.
2-bis(4-hydroxy-3,5-tert-7
Examples include tylphenyllopane, etc.], ascorbic acids, 3-viraso1nodones, pyrazolones, hydrazones, and nokurafunilenediamines.

Nokuinter used in the heat-developable photosensitive element of the present invention.

Although various binders can be used as binders, hydrophilic or hydrophobic binders can be used depending on the purpose.

For example, natural substances such as gelatin, gelatin derivatives, casein, sodium caseinate, proteins such as albumin, heptalose derivatives such as ethyl cellulose, polysaccharides such as dextran, polysaccharides such as agar, gum arabic, gum tragacanth, etc., polyvinyl alcohol, Synthetic polymers such as polyvinylpyrrolidone, water-soluble polyvinyl acetal, and latex vinyl compounds that increase the dimensional stability of photographic materials and synthetic polymers such as those described below may also be included. Suitable synthetic polymers include U.S. Pat. Nos. 3,142,586 and 3,193.
, No. 386, No. 3,062,674, No. 3,220,
No. 844, No. 3,287,289, No. 3,411,9
Examples include those listed in each specification of No. 11.

Useful polymers include water-insoluble polymers based on alkyl acrylates, methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates. Suitable polymeric substances include polyvinyl butyral, polyacrylamide cellulose acetate butyrate, cellulose acetate flobionate, polymethyl methacrylate, polyvinyl chloride,
Chlorinated rubber polyimbutylene, phthalene styrene copolymer, vinyl chloride-vinyl acetate copolymer vinyl acetate-vinyl chloride-copolymer with maleic acid, polyvinyl alcohol, polyvinyl acetate, pencil cellulose, vinegar [cellulose, cellulose flobionate, cellulose acetate] Examples include phthalates. Moreover, if necessary, two or more kinds may be used in combination.

The amount of the binder is 1/10 to 10 parts, preferably 1/4 to 4 parts by weight per 1 part of organic silver salt in each photosensitive layer. In the case where the dye is transferred by sublimation in the present invention is preferably a hydrophilic binder. Hydrophilic binders include protein colors such as gelatin, cellulose derivatives such as ethylcellulose, and water-soluble synthetic polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and water-soluble polyvinyl acetal, and these may be used alone or in combination of two or more. It can be used in

In addition to the above-mentioned components, various additives may be added to the heat-developable photosensitive element of the present invention as required. Examples of additives include development accelerators, toning agents, anti-capri agents, stabilizers, Sensitizer, alkali release agent, fluorescent brightener,
Hardeners, antistatic agents, antihalation agents, filter dyes, coating aids, etc. Regarding these, RII,
It is described in detail in Nα17029 (1978).

In the present invention, imagewise exposure to the heat-developable photosensitive element can be performed using sunlight, a tungsten lamp, a fluorescent lamp, a mercury lamp, a halogen lamp (such as a xenon lamp or an iodine lamp), a laser beam, a light emitting diode, a CRT, or a light emitting diode.
This is done using an FT (optical fiber tube) or the like.

For heat development in the present invention, all methods applicable to ordinary heat-developable photosensitive carbon can be used. For example, by contacting the photosensitive element with a heated plate, by contacting it with a heated roller or drum, by passing it through a high-temperature atmosphere, by using high-frequency heating, or by adding a conductive layer in the photosensitive element. It is also possible to use the Ziehl heat generated by electricity or a strong magnetic field. There are no particular restrictions on the heating pattern in thermal development, including a method of preheating and then heating again, a method of heating at a high temperature for a short time, or a low temperature for a long time, continuously increasing, decreasing, or repeating. Although reversing and even discontinuous heating are possible, a simple pattern is preferred. Usually, the developing temperature is 80℃~200℃
℃), and the development time is preferably in the range of 1 second to 10 minutes.

The heat development can also be carried out using a commercially available heat development machine. For example, 6 Image Forming Model 4634'' (Sony Tetatronics), ``Developer Sober Module 277'' (3M), ``Video Hard Copy Unit N''
Examples include WZ-301 (Japan Radio Co., Ltd.).

By thermal development, at least a portion of the imagewise distribution of the dye released from the dye-releasing reducing agent is thermally transferred, preferably sublimation-transferred, to the image-receiving layer by the heat during thermal development or by reheating. When the thermal image sensitive element and the image-receiving layer are in a stacked relationship, it means that they both share a support and form the same coating composition, or that they each have separate supports, A state in which the dye-releasing reducing agent-containing layer and the image-receiving layer are in close contact with each other, or in which both have separate supports, and the dye-releasing reducing agent-containing layer and the image-receiving layer are in a medium 1M1 layer, or Indicates that they fit together in a substantially parallel state with a certain gap in between. If the photothermographic element and the image-receiving layer are placed in a stacked relationship, it is possible to form a clear color image by transfer.

In the present invention, the image-receiving layer basically has only to have the function of stopping the transfer of the imagewise distribution of the thermally transferred dye and fixing it.

For example, it may be a single layer of gelatin or other synthetic polymer, or it may be a layer of wood pulp or other synthetic pulp fibers. In addition, in order to improve the transfer efficiency, in the image-receiving layer,
Inorganic compounds such as titanium white, silica, and acid clay may be added, and the pH may be adjusted.

Further, the image-receiving layer may be integrated with the photosensitive layer,
It may be in a form that can be separated from the photosensitive layer. Furthermore,
Originally, it does not have an image-receiving layer, and after being imagewise exposed, it is overlaid with any cloth (necklace, shirt, sheet) or paper, and then thermally developed, and an image can be formed using the cloth or paper as an image-receiving layer. It may be done.

If a chelatable dye (bost chelate dye) is used as the releasing dye, it is preferred that the image-receiving layer contains polyvalent metal ions.

A general image forming method using the heat-developable photosensitive element of the present invention is shown below.

(1) A recording material containing the above-mentioned heat-developable photosensitive element is cut into a suitable size and then imagewise exposed.

(2) Bring the heat-developable photosensitive element of the distribution material into contact with the image-receiving layer at a temperature of about 50 to 300°C, preferably 100 to 250°C, for 1 second to 10 minutes, more preferably 15 seconds to 3 minutes. , heat development, release of dye and thermal transfer.

As for the thermal transfer of the dye, a method using a solvent (including a thermal solvent) is also possible, but a sublimation transfer method in which the dye is transferred in a gaseous state is preferable.

(3) Subsequently, by peeling off the image-receiving layer from the heat-developable photosensitive layer, a color image based on the transferred dye can be obtained.

The present invention will be specifically described below using Examples.

Example-1 4-Hydroxybenzotriazole silver'1,26f and water-soluble polyvinyl butyral (Made by Block Chemical Co., Ltd., S-LEC W
-201) 25% aqueous solution 24-1 116-1 water and 70-methanol were added and pulverized and dispersed in an alumina ball mill,
An organic silver salt dispersion was obtained.

This silver salt dispersion 25Tn1. Phthalic acid 0.21? , Phthalazine 0.16F, the above-mentioned exemplary dye-releasing reducing agent (CPM
-2) 1.01f, exemplary coupler (C-3) 0.659
and water-soluble polyvinyl butyral 25% aqueous solution 5tn
1. , a silver iodide emulsion with an average grain size of 0.04μ was added to 36η in terms of silver, and the mixture was coated on photographic baryta paper with a wire bar to a wet film thickness of 55μ. The obtained sample was passed through a step wedge for 30 minutes. OOOCMS exposure was given.

On the other hand, diacetate ce/rellose (degree of acetylation: about 60%) was applied to Ipoly paper (1.407 jl/m2).
I coated it and made receiver paper.

The coated surface of the exposed sample was brought into close contact with the image-receiving paper, and the image-receiving paper was peeled off after being pressed and heated for 30 seconds with an iron having a surface temperature of 180°C. An orange step wedge negative image with a maximum reflection density of 0.97 and a minimum reflection density of 0.22 was obtained on the surface of the receiving paper.

On the other hand, as a comparative sample, the preparation method was exactly the same as the above except that the following comparative dye-releasing reducing agent 1.35r was used in place of the dye-releasing reducing agent (CPM-2) according to the present invention. When a heat-developable photosensitive layer was prepared and exposed and heat-developed in exactly the same manner as above, no transferred image could be obtained on the surface of the image-receiving paper.

(Dye-releasing reducing agent) (Compound described in JP-A-57-179840) Example 2 The same sample was prepared and exposed and developed in the same manner as in Example 1. Maximum reflection density 0.9
3. A negative image of the step wedge with a minimum reflection density of 0.19 was obtained.

Example-3 Example-3 except that the exemplified dye-releasing reducing agent (CPM-2) of Example 1 was replaced with 1.15f of exemplified CPM-17.
Got 1.

On the other hand, an aqueous solution containing 15% water-soluble polyvinyl butyral and 8% nickel chloride was applied to Ipoly paper at an amount of 1.40 g' of 9 polyvinyl butyral per square meter to form an image-receiving paper containing nickel chloride. Had made.

The coated surface of the exposed sample described above and the coated surface of the image-receiving paper were pressed together and heated for 30 seconds using a six-sided hot iron at 150° C., and the sample and the image-receiving paper were peeled off.

The receiver paper has a maximum reflection density of 1.11, a minimum reflection density,
A negative image of a magenta step wedge at 0°18 was obtained.

Example-4 Behen e 4.5 y, toluene 20, acetone 2
〇- and polyvinyl butyral 3.2'? Add
Dispersion-1 was prepared using an ultrasonic homogenizer.

Behenic acid dispersion-2 was obtained by heating and dissolving 3.4 f of behenic acid in 40 tnl of polyvinyl butyral 8 subfluorinated thiacetone solution and stirring while cooling with water.

On the other hand, 7talic acid 0.20 f, phthalazine 0.135'
, and exemplified CP M-6,4,56 were mixed with 5.87 mL of exemplified coupler (C-1) in 40 ml of polyvinyl butyral 8 subfluorinated thiacetone solution to obtain solution-1.

Further, silver trifluoroacetate and beautified lithium were reacted in an acetone solution containing 10% polyvinyl butyral to obtain Emulsion-1.

10rn1 of Dispersion-1 and 1()- of Dispersion-2 were mixed, and 0.3 ml of a 0.05% by weight methanol bath solution of the following sensitizing dye and 20 ml of 2X silver acetate were added thereto.

(Sensitizing Dye) Finally, Emulsion-1 was added and coated onto a transparent polyester film using a wire bar to a wet film thickness of 74 μm to form a photosensitive layer.

A white reflective layer and a receiving fIN layer having the following composition were provided thereon, and another transparent polyester film was adhered onto the receiving layer.

<White reflective layer> (Unit 7/-
) Titanium dioxide (average particle size 1.5p) 1
5 Cellulose diacetate 1.2 Sodium dodecyl sulfate 0.08 Ethanol 25 Water
30 Image receiving layer> (Unit?/rr?) Cellulose diacetate 1.6 Ethanol 21 Water
42 For the photosensitive side of this sample, pass the step wedge through the
Exposure was given to 0,000 CMS, and an iron having a surface temperature of 150° C. was pressed onto the photosensitive layer side for 30 seconds. An orange negative image with a maximum reflection density of 1.12 and a minimum reflection density of 0.25 was obtained in the image receiving layer.

The photosensitive layer of this sample, which had been thermally developed, was irradiated with a fluorescent lamp (daylight color, 40 watts, distance % 430 cIn) for 100 hours to cause printout, but the minimum reflection density of the image-receiving layer increased. was only 0.02.

Example-5 Dispersion-3 was obtained.

After mixing the dispersion-3 with 25-1 solution-2, a silver bromide emulsion with an average grain size of 0.04 μm was obtained in terms of silver.
．． 11f was added and coated on photographic baryta paper to form a photosensitive material.

30. Pass the obtained sample through a step wedge.
After exposure of 00 (IcMs), the same image-receiving paper as in Example-1 was placed in close contact with the sample, heated for 40 seconds with an iron having a surface temperature of 180° C., and then the image-receiving paper was peeled off.

The receiving paper has a maximum reflection density of 0.62 and a minimum reflection density of 0.1.
A yellow negative image of No. 1 was obtained.

Example-6 Dispersion-4 was obtained.

After mixing 25 fn of the dispersion-4 and 15 fn of the 1% solution-3, 0.11 f of silver bromide milk with an average particle size of 0.04 μm was added, and the mixture was coated on a photographic baryta. A photosensitive layer was formed.

30 minutes through a step wedge against the formed sample.
．． After exposure of 000 CMS, the coated surface of the same image-receiving paper used in Example-1 was brought into close contact with the coated surface of the sample, and after pressing and heating with an iron with a surface temperature of 180°C for 30 seconds, the image-receiving paper was exposed. I tore off the paper.

A yellow positive image with a maximum reflection density of 1.29 and a minimum reflection density of 0.17 was obtained on the surface of the receiving paper.

Effects of the Invention The heat-developable photosensitive element containing the dye-releasing reducing agent according to the present invention can obtain a clear transferred image with excellent maximum density and less capri on image receiving paper by thermal development. Yoshimi Hara

Claims (1)

[Scope of Claims] At least one heat-developable photosensitive material containing, on a support, (a) an organic silver salt, (b) a coupler, and (c) a dye-releasing reducing agent represented by the following general formula (1). A heat-developable photosensitive element characterized by having a layer. represents the general formula (D R1 ■ 3 and R2 and R3 each represent an alkyl group or an aryl group), Y represents an atomic group necessary to complete a benzene ring or a naphthalene ring, and I Dye-N- Represents a thermally diffusible dye residue, R1 represents a hydrogen atom, an alkyl group, or an aryl group0]