JPS6283746A - Heat developable photosensitive material - Google Patents

Abstract

PURPOSE:To reduce the desensitization of a heat developable photosensitive material by heat development and to increase the sensitivity by combinedly incorporating specified photosensitive silver halide particles and at lease one kind of specified compound into at least one of the silver halide emulsion layers of the photosensitive material. CONSTITUTION:Photosensitive silver halide particles having 4-40mol% silver iodide content and <=0.4mum average particle size and at least one kind of compound represented by formula I or II are combinedly incorporated into at least one of the silver halide emulsion layers of the heat developable photosensitive material. In formula I, R1 is H, alkyl, aryl or a heterocyclic group, each of R2 and R3 is alkyl,each of Y1 and Y2 is S or Se, X1<-> is an anion and m=0 or 1. In formula II, each of R4-R7 is H or alkyl, Y3 is N, S or Se and when Y3 is S or Se, R4 is not present. Thus, the desensitization of the photosensitive material by the heat development is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-developable photosensitive material, and more particularly to a highly sensitive heat-developable photosensitive material with little desensitization caused by heat development.

[Back East of the Invention] Compared to the conventional wet method, the method of performing the developing process to obtain an image by dry heat treatment reduces processing time, cost,
It has many advantages in terms of concerns about environmental pollution and pollution.

Regarding heat-developable photosensitive materials in which the above-mentioned development process can be carried out by dry heat treatment, for example, Japanese Patent Publication No. 43-4921 and No.
This is described in Japanese Patent No. 3-4924, which discloses a black and white type photothermographic material comprising an organic silver salt, silver halide and a reducing agent.

Attempts have also been made to improve such heat-developable photosensitive materials and obtain color images by various methods.

For example, JP-A-57-179840, JP-A No. 57-1867
No. 44, No. 57-198458, No. 57-2072
No. 50, No. 58-40551, No. 58-58543, No. 58-79247, No. 59-12431, No. 59-22049, No. 59-68730, No. 59
-124339, 59-124333, 59-
No. 124331, No. 59-159159, No. 59-1
No. 81345, No. 59-159161, No. 58-11
No. 6537, No. 58-123533, No. 58-1
There are No. 49046 and No. 58-14947.

The basic composition of a color type heat-developable photosensitive material for obtaining color images consists of a photosensitive element and an image receiving element. ), a dye-providing substance, and a binder. In the present invention, only the photosensitive element is referred to as a heat-developable photosensitive material in a narrow sense.

In the former black and white type, optical information is given to the photosensitive silver halide by image exposure, and during thermal development, the exposed photosensitive silver halide and the reducing agent in the photosensitive layer are present in the vicinity. The catalytic action of silver halide causes an oxidation-reduction reaction to produce silver, and the exposed areas of the photosensitive layer turn black to form a silver image.

In addition, in the color type, optical information is given to the photosensitive silver halide by image exposure, and in heat development,
Under the action of a reducing agent, dissolution physical development is performed between organic silver salts and photosensitive silver halide according to optical information, and the reducing agent that has acted or has not acted reacts with the dye-donating substance. By doing so, the dye that forms the image is released or formed. The image-forming dyes developed by thermal development are transferred to an image-receiving element to form an image.

In the above-mentioned silver-image-forming black-and-white type and color type heat-developable photosensitive materials, images are usually formed by heat development after exposure or at the same time as exposure, but in general heat development involves heating to a high temperature of 80"C or higher. Therefore, various effects appear on photosensitive silver halide.One of the biggest effects is
One is desensitization by heat development. That is, compared to the sensitivity when an exposed heat-developable photosensitive material is developed at 40°C or lower using a normal wet photographic processing solution, the sensitivity is significantly lower when it is thermally developed at a temperature of 80°C or higher. It has become clear that this decreases. Furthermore, it has been found that desensitization due to heat development is significant in heat-developable photosensitive materials containing sensitizing dyes.

The desensitization phenomenon caused by heat development is thought to be caused by a part of the latent image formed on the exposed photosensitive silver halide grains being thermally bleached by heat development, but the detailed mechanism is not clear.

Furthermore, adding a sensitizing dye to silver halide gives silver halide high photosensitivity to visible light to infrared light, and is an essential component in heat-developable light-sensitive materials. It has been desired to improve the undesirable desensitization.

The present inventors have discovered that the above-mentioned desensitization in a heat-developable photosensitive material can be achieved by using a combination of two specific sensitizing dyes, containing silver iodide in a specific range, and having an average grain size of a specific value. The inventors have discovered that improvements can be achieved by using the following photosensitive silver halide grains, and have thus arrived at the present invention.

[Object of the invention] Therefore, the object of the present invention is to reduce desensitization due to heat development and to reduce desensitization by heat development.
The object of the present invention is to provide a highly sensitive heat-developable photosensitive material.

[Structure of the Invention] The above object of the present invention is to provide a thermal development (!!Irft optical material) with a silver iodide content of 4.
~40 mol% of photosensitive silver halide grains with an average particle size of 0.4 μm or less, at least one compound represented by the following general formula (I), and at least one compound represented by the following general formula (I). This can be achieved by using a heat-developable photosensitive material containing a combination of the following.

General Formula (I) In the formula, R1 represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group, and R2 and R3 each represent an alkyl group. Yl and Y2 each represent a sulfur atom or a serene atom.

zl, z2, Z3 and Zl are each a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, an acyl group,
Represents an alkoxycarbonylbonylamino group, an alkyl group or a cyan group. However, Zl and Z2 and/or Z3 and 74 may be linked to each other to form a ring. ×10 represents anion,
m represents an integer of O or 1;

General formula (II) In the formula, R4, R5, R6 and R7 each represent a hydrogen atom or an alkyl group. Y3 represents a nitrogen atom, a sulfur atom, or a selenium atom, but when Y3 is a sulfur atom or a selenium atom, it does not have the above R1. Z
5, Z6, Zl and Z8 each represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, an acyl group, an acylamido group, an acyloxy group, an alkoxycarbonylurbonylaminocyano group or a sulfonyl group. However, Z5 and 7
6 and/or Zl and 78 may be linked to each other to form a ring. X? represents an anion, and n represents an integer of O or 1.

[Specific Structure of the Invention] The compounds represented by general formula (I) and general formula (n), respectively, used in the present invention (hereinafter referred to as compounds of the present invention) are sensitizing dyes.

In the general formula (I), the alkyl group represented by R1 is preferably a lower alkyl group, such as a methyl group, an ethyl group, a propyl group, etc., with an ethyl group being preferred. Further, examples of the aryl group include a phenyl group, and examples of the heterocyclic group include a furyl group and a diophyl group.

Next, the alkyl group represented by R2 and R3 is preferably a lower alkyl group, such as a methyl group, an ethyl group, a butyl group, or a sulfonidelsulfobutyl group having a substituent, but a sulfopropyl group is preferable. .

Roughly speaking, Zl, Z2, Z3 13 and Z4 are respectively represented, and the halogen atoms include, for example, chlorine, bromine, iodine, and fluorine atoms, and at least one of Z+ and Z2, and at least one of Z3 and Z4, A chlorine atom is preferred. Examples of alkoxy groups include methoxy, ethoxy, propoxy, and butoxy groups; acyl groups include acetyl groups; and acylamide groups include acetamide, propionamide, and other groups. Examples of alkoxycarbonyl groups include ethoxycarbonyl and propoxycarbonyl, examples of alkoxycarbonylamino groups include ethoxycarbonylamino and propoxycarbonylaminolamino, and aryl groups include: For example, there are groups such as phenyl and tolyl, and as alkyl groups,
Preferred are lower alkyl groups such as methyl, ethyl, propyl and the like.

The ring formed by connecting Zl and z2 and/or Z3 and Z4 is a benzene ring, but when Zl and Z
It is preferred that 2, z3 and Z4 together form a benzene ring. This benzene ring may further have a substituent. Furthermore, in the general formula (I), examples of the anion represented by x1θ include chloride, bromide, iodide, thiocyanate, sulfamate, methyl sulfate, ethyl sulfate, verchlorate, p-toluenesulfonate, and the like.

In general formula (II), next R4, Rs, Rs
The alkyl group represented by R7 is preferably a lower alkyl group, including methyl, ethyl, butyl, and groups having substituents such as sulfoethyl, carboxypropyl, and sulfobdel.

Furthermore, Z5, Z6, z7 and Z8 each represent a halogen atom such as chlorine, bromine, iodine, or fluorine, and an alkoxy group such as methoxy, ethoxy, propoxy, butoxy, etc. There are various groups, and examples of the acyl group include acetyl kudzu,
Examples of acylamido groups include ace-1-amide and propionamide groups; examples of acyloxy groups include acetoxy and propionoxy groups; and examples of alkoxycarbonyl groups include 1-toxy carbonyl groups. There are various groups such as , propoxycarbonyl, etc.
Aryloxycarbonyl groups include phenoxycarbonyl, and alkoxycarbonylamino groups include:
For example, there are groups such as ethoxycarbonylamino, propoxycarbonylamino, butoxycarbonylamino, etc. Aryl groups include, for example, phenyl and tolyl groups, and preferable alkyl groups include lower alkyl groups such as methyl, ethyl, propyl, etc. Examples of the group and sulfonyl group include an alkylsulfonyl group, an aminosulfonyl group, a morpholinosulfonyl group, and a piperidinosulfonyl group. The ring formed by connecting Z5 and 76 and/or Zl and 78 is a benzene ring, and this benzene ring may further have a substituent. Furthermore, in the general formula (II), X P
Examples of anions represented by include chloride, bromide, iodide, thiocyanate, sulfamate, methylsulfate-1, ethylsulfate, verchlorate, p-
Examples include toluene sulfonate.

Typical compounds represented by the general formula (I) used in the present invention are shown below, but the present invention is not limited thereto.

The following margins (exemplary compounds) Sa, Zan, (I-19) Zan, (i-23) - (I-30) (I-32) (NiH2)4S3Na (I-38) (I-49' ) (C)(2-3803Na) In the present invention, a more preferable compound among the compounds represented by the general formula (I) is the following general formula (ITA).
and (IrB).

General formula (IA) In the formula, Ra, R9, Rho, and Rlt represent lower alkyl groups (for example, methyl, ethyl, butyl, and other substituent groups, such as sulfoethyl, carboxypropyl, and sulfobutyl groups). , ethyl, sulfopropyl, and sulboacyl groups are preferred. Z9, Z
oo, Z++13, UZ+2G, t, respectively hydrogen atom, Ha0gun atom (for example, chlorine, bromine, iodine, fluorine atoms, but Zs, Zoo, Z++, Z+
It is preferable that all 2 are chlorine atoms. ), hydroxyl group, alkoxy group (for example, methoxy, ethoxy, propoxy, butoxy groups, but z9 and Z1a1
It is preferred that at least one of each of 5, Z+1 and 212 is a butoxy group. ), acyl group (e.g., acetyl group, etc.), acylamido group (e.g., acetamide, propionamide, butyramide groups, etc.), acyloxy group (e.g., acetoxy, propionoxy group, etc.)
, alkoxycarbonyl groups (e.g., ethoxycarbonyl, propoxycarbonyl groups, etc.), aryloxycarbonyl groups (e.g., phenoxycarbonyl groups, etc.), alkoxycarbonylamino groups (e.g., ethoxycarbonylamino, propoxycarbonylamino, butoxycarbonylamino groups, etc.) ), aryl groups (e.g., phenyl groups, etc.), lower alkyl groups (e.g., methyl, trifluoromethyl, ethyl, buOvir groups, etc.), sulfonyl groups (alkylsulfonyl groups, aminosulfonyl groups, morpholinosulfonyl, piperidino groups, etc.) sulfonyl groups, etc.), a cyano group (preferably at least one of each of Zs and Zoo and Zll and Z+2 is a cyano group), and the like. Further, Zs and Zoo and/or Zll and Z+2 may be connected to each other to form a ring, and this ring is, for example, a benzene ring.

X3CI) represents an anion (for example, chloride, bromide, iodide, thiocyanate, sulfamate, methyl sulfate, ethyl sulfate, verchlorate, p-toluenesulfonate, etc.), and A represents an integer of 0 or 1.

General formula (IIB) In the formula, Y4 represents a sulfur atom or a selenium atom, and R+
2, R+3 and R+4 each represent a lower alkyl group (for example, a methyl, ethyl, butyl group, or a substituent such as a sulfoethyl, carboxypropyl, or sulfobutyl group), preferably ethyl and sulfopropyl. r-al. 213, Z+4, Z +
s J5 J: TJ Z +s LL, respectively hydrogen atom, halogen atom (e.g. chlorine, bromine, iodine, fluorine atoms), hydroxyl group, alkoxy group (e.g. methoxy, ethoxy, propoxy, butoxy groups, etc.),
Acylamide groups (e.g. acetamide, propionamide groups, etc.), acyloxy groups (e.g. acetoxy, propionoxy groups, etc.), alkoxycarbonyl groups (e.g. ethoxycarbonyl, propoxycarbonyl groups, etc.), alkoxycarbonylamino groups (e.g. ethoxycarbonylamino, propoxycarbonylamino, butoxycarbonylamino groups, etc.), aryl groups (e.g. phenyl M), lower alkyl groups (e.g. methyl, trifluoromethyl, ethyl, propyl groups, etc.), sulfonyl groups (alkylsulfonyl group, dimethylaminosulfonyl group, etc.). Further, Z13, Z14 and/or Z+s and Z+s may be linked to each other to form a ring, and this ring may be, for example, a benzene ring. Preferably, Z13 and 714 are linked to form a benzene ring, and at least one of Z+s and 716 is methyl trifluoride.

×4° is an anion (e.g. chloride, bromide, iodide, thiocyanate, sulfamate, methyl sulfate,
ethyl sulfate, verchlorate, p-toluenesulfonate, etc.), and p represents an integer of 0 or 1. However, when the compound forms an inner salt, p represents 0.

The general formulas (IIA) and (IrB) of the present invention are shown below.
Typical examples of compounds represented by are shown below, but the present invention is not limited thereto.

Below margins (IIA-7) (IIA-8) (mA-9) (nA-11) (IIA-12) (IA-13) (ilA-14) (mA-15) (IIA-16) (IA- 17) (■A-18) (IIA-19) (IIA-36) (IA-37) (IIA-38) (nA-39) Ha (IIB-7) rO (l[B-13). ,H40H
O30 (IIB-30) The compounds of the present invention (represented by the above general formulas (I) and (II)) are disclosed in JP-A-49-114419, JP-A-55-1569, JP-A-56-39460, etc., respectively. The compound of the present invention can also be synthesized according to the publication.

In the present invention, spectral sensitization is carried out by adding the compound of the present invention to a silver halide emulsion containing the photosensitive silver halide grains of the present invention described below.

The compound of the present invention may be added at any stage, such as at the beginning of chemical ripening (also referred to as second ripening) of the silver halide emulsion, during or after ripening, or at an appropriate time prior to coating the emulsion. .

Further, when adding the compounds of the present invention in combination, they may be added at the same time or at different times, but it is preferable to add them at the same time.

Further, as a method for adding the compound of the present invention to a silver halide emulsion, various methods conventionally used in the page printing industry can be applied. For example, US Patent No. 3,469,987
As described in No. 1, etc., the compound of the present invention may be dissolved in a mixed solvent, the solution may be dispersed in a hydrophilic colloid, and this dispersion may be added to an emulsion. The compounds of the invention can also be dissolved individually in the same or different solvents, and the solutions can be mixed before being added to the emulsion, or they can be added separately.

As the solvent used to dissolve the compound of the present invention, water-miscible organic solvents such as methyl alcohol, ethyl alcohol, and acetone are preferably used.

When the compound of the present invention is added to a silver halide emulsion, the compound of general formula (I), the compound of general formula (It)
In each of the compounds, the amount is preferably from 1.times.10@-5 to 2.5.times.10@-2 mol, more preferably from 1.0.times.10@-4 to 1.0@-2 mol per mol of photosensitive silver halide. OXiQ
-3 moles. The ratio of the compound represented by the general formula (I) to the compound represented by the general formula (IF) is, when the compound represented by the general formula (I) is 1, the compound represented by the general formula (It) is is in the range of 0.1 to 10.

In the present invention, other compounds used as sensitizing dyes or compounds used as supersensitizers can also be used in combination with the compounds of the present invention.

The photosensitive silver halide grains used in the present invention have a silver iodide content of 4 mol% to 40 mol%, more preferably a silver iodide content of 4 mol% to 20 mol%.

The average grain size of the photosensitive silver halide grains used in the present invention is 0.4 μm or less, more preferably 0.01 μm.
m to 0.4μI, more preferably 0.05u
m −0.48 m.

In the present invention, the average particle size of photosensitive silver halide grains refers to the diameter in the case of spherical silver halide grains, and the projected image of the same area in the case of cubic or non-spherical grains. It is the average value of the diameter when converted into a circular image, and when the individual particle diameter is i and the number is ni, r is defined by the following formula.

Note that the particle size can be measured by various methods commonly used in the technical field for the above purpose. A typical method is Loveround [Particle Size Analysis Method JA].

S, T, M, Symposium on Light Microscopy, 1955, pp. 94-122 or chapter 2 of [Theory of the Photographic Process] by Mies and James, 3rd edition, Macmillan Publishing Co., Ltd. (1966). Are listed. The particle size can be measured using the projected area or approximate diameter of the particle.

If the particles are of substantially uniform shape, the particle size distribution can be described fairly accurately as diameter or projected area.

In the photosensitive silver halide used in the present invention, there are no particular restrictions on other silver halide components in the photosensitive silver halide containing silver iodide, but preferred silver halide components include silver iodobromide. , and silver chloroiodobromide.

The photosensitive silver halide containing silver iodide used in the present invention is a photosensitive silver halide containing silver iodide, written by B. Gerafkides, published by Himie et Physique Photographic (published by Ball Montell).
(p, Qlafkides, Chimie etPh
ysique Photographique, P
aul Montel) (1967), G.F. Duffin, Photographic Emulsion Chemistry (The Focal Press) (G, F, D
uNin.

Photographic [:mulsion Ch
emistry, TheFocal Pres
s) (1966), Bui El Celikman et al., Making and Coating Fluid Emulsions (The Focal Press)
(V, L, Zelilvan et al.

MakinG and CoatinOPhotogr
aphicl:mulsion, The Foc
al press) (1964).

That is, any of the acid method, neutral method, ammonia method, etc. may be used, but the ammonia method is particularly suitable. Further, as a method for reacting the soluble silver salt and the soluble halogen salt, any one of a one-sided mixing method, a simultaneous mixing method, a combination thereof, etc. may be used. It is also possible to use a back mixing method in which silver halide grains are formed in an excess of silver ions. As one of the simultaneous mixing methods, a Chondrald double jet method can also be used, in which I) Ag in the solution in the reaction vessel in which silver halide is produced is arbitrarily controlled, and the addition rate of the silver and halogen solutions is controlled. According to this method, a so-called monodisperse silver halide emulsion in which the individual crystal shapes and grain sizes of silver halide grains are nearly uniform can be obtained.

In the present invention, the above-mentioned monodisperse silver halide emulsion means that the grain size distribution of the silver halide grains contained in the emulsion has a particle size distribution in which the variation in grain size is less than a certain proportion of the average grain size as shown below. refers to what one has. The grain size distribution of a photosensitive silver halide emulsion (hereinafter referred to as a medium dispersion emulsion), which is composed of a group of grains with uniform grain morphology and small variation in grain size, shows an almost normal distribution, and is similar to the standard When the deviation is easily determined and the width of the distribution is defined by the relational expression η , the preferred width of the distribution of the photosensitive silver halide grains used in the present invention is 15%.
or less, and more preferably monodispersity with a distribution width of 10% or less.

More preferred photosensitive silver halide grains used in the present invention are core/shell type having a surface latent image type shell.

A core/shell type photosensitive silver halide emulsion which is more preferably used in the present invention can be produced by coating monodisperse photosensitive silver halide grains as a core with a shell.

In order to make the core a monodisperse silver halide grain, 1) Ag
Particles of desired size can be obtained by the double-jet method while keeping the particle size constant. Further, silver halide emulsions containing highly monodisperse photosensitive silver halide can be prepared by the method described in JP-A-54-48521. In a preferred embodiment of the method, an aqueous potassium-gelatin solution and an aqueous ammoniacal silver nitrate solution are added to an aqueous gelatin solution containing silver halide seed particles.
It is manufactured by a method of adding by varying the addition rate as a function of time. At this time, by appropriately selecting the time function of addition rate, DHS llAg, temperature, etc., it is possible to obtain a silver halide emulsion containing 8 degree monodisperse silver halide grains for the core.

By sequentially growing shells according to the manufacturing method of monodisperse emulsion using monodisperse core particles as described above,
A silver halide emulsion containing monodisperse core/shell type photosensitive silver halide which is more preferably used in the present invention can be obtained.

In the core/shell type photosensitive silver halide which is more preferably used in the present invention, the thickness of the shell covering the core is preferably 0.05% to 90%, more preferably 1% to 90% of the silver halide grain size. It is in the range of 80%. In the silver halide composition of the core, the silver iodide content is preferably 4 mol% to 20 mol%, and in the shell silver halide composition, the silver iodide content is preferably 0 mol% to 6 mol%. More preferably, it is a core/shell type silver halide in which the silver iodide content in the core is 2 mol % or more higher than the silver iodide content in the shell.

The photosensitive silver halide emulsion containing photosensitive silver halide used in the present invention may be chemically sensitized by any method in the field of photography. Such sensitization methods include various methods such as gold sensitization, sulfur sensitization, gold-A sensitization, and reduction sensitization.

In the present invention, as a method for forming other photosensitive silver halide grains, a photosensitive silver salt forming component is allowed to coexist with an organic silver salt to be described later, and a photosensitive silver halide is formed in a part of the organic silver salt. You can also do it. The photosensitive silver salt forming component used in this preparation method is an inorganic halide, for example, a halide represented by MXn (where M is an H atom, NH+
a or a metal atom, X represents C, ffi, Br or I, n is 1 when M is an H atom and NH4N, M
When is a metal atom, it indicates its valence. Metal atoms include lithium, sodium, potassium, rubidium, cesium, copper, gold, beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, aluminum, indium, lanthanum, ruthenium, thallium, germanium, tin, lead, antimony, bismuth, chromium, molybdenum, tungsten, manganese,
Examples include rhenium, iron, cobalt, nickel, rhodium, palladium, osmium, iridium, platinum, and cerium. ), halogen-containing metal complexes (for example, K2P
t C16, 2 Pt 3r s, HAtl CN
4゜(NH4)2 1r Cff1s, (NH4)31
rCji! s.

(NH4)2 RLI CN2. s, (NH4>3RL
I Cfs.

(NH4)2 Rh C11G (NH4)3 R1
1Br6, etc.), onium halides (e.g., quaternary ammonium halides such as tetramethylammonium bromide, trimethylphenylammonium bromide, cetyl nibbledimethylammonium bromide, 3-methylthiazolium bromide, trimethylbenzylammonium bromide, tetraethyl 7A sulfanium) quaternary phosphonium halides such as bromide, benzylethylmethylsulfonium bromide, tertiary sulfonic cum halides such as 1-edylthiazolium bromide, etc.), halogenated hydrocarbons (e.g. iodoform, bromoform, tetrabromide, etc.) carbon, 2-bromo-2-methylpropane, etc.), N-halogen compounds (N-chlorosuccinimide, N-bromosuccinimide, N-bromophthalimide, N-bromoacetamide, N-iodosuccinimide, N-bromo Phthalazinone, N-chlorophthalazinone, N-bromoacetanilide, N,N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, 1,3-dibromo-4,4-
dimethylhydantoin, etc.), and other halogen-containing compounds (for example, triphenylmethyl chloride, triphenylmethyl bromide, 2-bromobutyric acid, 2-bromoethanol, etc.).

These photosensitive silver salt-forming components and photosensitive silver halide grains can be used in combination in various methods, and the used product preferably has an amount of O,001 to 50 g per 1f per -F, more preferably , 0.1Q to 109.

The heat-developable photosensitive material of the present invention uses photosensitive silver halide having a silver iodide content of 4 to 40 mol % and an average grain size of 0.4 μm or less as described above, and further has the formula (I) as described above. It is characterized in that at least one compound represented by the formula (I) is used in combination with at least one compound represented by the general formula (I).

The heat-developable photosensitive material of the present invention can be applied to any photosensitive material that forms an image by heat development.

For example, there are black and white types that form a silver image by heat development, and color types that include a dye-providing substance. In this latter color type, further monochromatic, e.g., monochromatic, with a black dye-donor or any other monochromatic dye-donor; polychromatic, e.g.
Examples include mature Q color light-sensitive materials that develop yellow, cyan, and magenta colors. In the color type, a method is usually used in which only the developed dye is transferred to the image receiving member.

The present invention exhibits particularly favorable effects when applied to the latter color type.

In the black-and-white type in which the heat-developable photosensitive material of the present invention forms a silver image, the photosensitive layer, which is basically a silver halide emulsion layer on a support, contains (1) photosensitive silver halide, (2) reduction agent and (3) binder, and if necessary (4)
) contains an organic silver salt.

In addition, in the color type that forms a dye image, the photosensitive layer, which is basically one silver halide emulsion layer on the support, contains (1) photosensitive silver halide, (2) reducing agent, (3)
) a binder and (5) a dye-providing substance, and optionally (4) an organic silver salt. However, these do not necessarily need to be contained in a single photosensitive layer; for example, the photosensitive layer may be divided into two layers, (1), (2), (3), (
Two or more photosensitive materials can be used as long as they can react with each other, such as by containing the component (4) in one photosensitive layer and containing the dye-providing substance (5) in the other layer adjacent to this photosensitive layer. It may be contained in separate layers.

Furthermore, the photosensitive layer may be divided into two or more layers, such as a high-sensitivity layer and a low-sensitivity layer, and may further include one or more photosensitive layers having different color sensitivities. Yes, various types of coatings such as top coat layer, undercoat layer, backing layer, intermediate layer, etc.
I! It may have stratification.

Similar to the heat-developable photosensitive layer of the present invention, the protective layer, intermediate layer, undercoat layer, back layer, and other photographic constituent layers are coated with respective coating solutions using the dipping method, air knife method, curtain coating method or the U.S. A photothermographic material can be prepared by various coating methods such as the hopper coating method described in Japanese Patent No. 3,681,294.

Additionally, if desired, 211I or more can be applied simultaneously by the methods described in US Pat. No. 2,761,791 and British Patent No. 837,095.

The photosensitive layer and other components used in the photographic composition β of the heat-developable photosensitive material of the present invention are coated on a support, and the coating thickness after drying is preferably 1 to 1,000 μm, more preferably 3 to 20 μm. This is the item.

In the heat-developable photosensitive material of the present invention, various organic silver salts can be used, if necessary, for the purpose of increasing sensitivity and improving developability.

Examples of organic silver salts used in the heat-developable photosensitive material of the present invention include Japanese Patent Publications No. 43-4921, No. 44-26582, No. 45-18416, No. 45-12700, No. 45-
No. 22185, JP-A-49-52626, JP-A No. 52-3
No. 1728, No. 52-137321, No. 52-14
No. 1222, No. 53-36224 and No. 53-37
Publications such as No. 610 and U.S. Patent No. 3.330.6
No. 33, No. 3,794,496, No. 4,105,
No. 451, No. 4.123.274, No. 4,168
Silver salts of aliphatic carboxylic acids such as silver laurate, silver myristate, silver palmidate, silver stearate, silver arachidonate, silver behenate, α -(1-7enyltetrazolethio)silver acetate, etc., silver aromatic layer carboxylates, such as silver benzoate, silver phthalate, etc., Japanese Patent Publication No. 44-26582, No. 45
-12700, 45-18416, 45-22
No. 185, JP-A-52-31728, JP-A No. 52-137
No. 321, JP-A-58-118638, JP-A No. 58-11
Silver salts of imino groups such as those described in publications such as No. 8639, such as benzotriazole silver, 5-nitrobenzotriazole silver, 5-chlorobenzotriazole silver,
5-methoxybenzotriazole silver, 4-sulfobenzotriazole silver, 4-hydroxybenzotriazole silver, 5-aminobenzotriazole silver, 5-carboxybenzotriazole silver, imidazole silver, benzimidazole silver, 6-nidropenzimidazole silver, Pyrazole silver, urazole silver, 1,2.4-triazole silver, 1H
-tetrazole silver, 3-amino-5-benzylthio-1
, 2,4-)-Riazole silver, saccharin silver, phthalazinone silver, phthalimide silver, etc., 2-mercaptobenzoxazole silver, mercaptooxadiazole silver,
2-mercaptobenzothiazole diimidazole silver, 3-mercapto-4-phenyl-
1.2.4-t-Riazole silver, 4-hydroxy-6-
Examples include methyl-1.3,38.7-titrazaindene silver and 5-methyl-7-hydroxy-1,2.3.4.6-pentazaindene silver. Among the above organic silver salts, imino group silver salts are preferred, and silver salts of benzotriazole derivatives are particularly preferred, and silver salts of sulfobenzotriazole derivatives are particularly preferred.

The organic silver salt used in the present invention can be used alone or as 2fi
It may be used in combination with JX, or the isolated silver salt may be dispersed in a binder by an appropriate means and used, or the silver salt may be prepared in an appropriate binder and used as is without isolation. It may be put to use.

The amount of the organic silver salt used is preferably 0.01 to 500 mol, more preferably 0.1 to 100 mol, per 1 mol of photosensitive silver halide.

As the reducing agent used in the heat-developable photosensitive material of the present invention, those commonly used in the field of heat-developable photosensitive materials can be used. For example, U.S. Pat.
No. 761,270, the specifications of No. 3,764,328, and RD No. 12146, same No. 15
108, same No.

Examples include p-phenylenediamine and p-aminophenol developing agents, phosphoramidophenol and sulfonamidophenol developing agents, and hydrazone color developing agents described in No. 15127 and JP-A-56-27132, etc. . Also, U.S. Patent No. 3,
342,599, 3,719,492, JP-A-53-135628, JP-A-54-79035, etc., color developing agent precursors and the like can also be advantageously used.

As a particularly preferable reducing agent, JP-A-56-146133
Examples include reducing agents represented by the following general formula (1) described in No.

General formula (1) In the formula, R' and R2 represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms (preferably 1 to 4) which may have a substituent, and R' and R2 are The ring may be closed to form a heterocycle. R3, R'l-R' and R
6 is a hydrogen atom, a halogen atom, a hydroxy group, an amine group, an alkoxy group, an acylamido group, a sulfonamide group, an alkylsulfonamide group, or a carbon atom number of 1 to 30 (preferably 1 to 4) that may have a substituent. represents an alkyl group, and R3 and R' and R5 and R2 may each be closed to form a heterocycle. M represents an alkali metal atom, an ammonium group, a nitrogen-containing organic base, or a compound containing a quaternary nitrogen atom.

The nitrogen-containing organic base in the general formula (1) is an organic compound containing a nitrogen atom that exhibits basicity capable of forming a salt with an inorganic acid, and particularly important organic bases include amine compounds. Chain amine compounds include primary amines, secondary amines, tertiary amines, etc., and cyclic amine compounds include lysine, quinoline, piperidine, etc., which are well-known examples of typical heterocyclic organic bases. , imidazole and the like. In addition, compounds such as hydroxylamine, hydrazine, and amidine are also useful as chain amines. In addition, as salts of nitrogen-containing organic bases, inorganic salts of organic bases such as those listed above can be used! i! salts (e.g. hydrochlorides, sulfates,
nitrates, etc.) are preferably used.

On the other hand, examples of the compound containing quaternary nitrogen in the above general formula include salts or hydroxides of nitrogen compounds having a tetravalent covalent bond.

Below is a margin.Next, preferred specific examples of the reducing agent represented by the general formula (1) are shown below.

(R-1) (R-2) (R-3) (R-4) CJi”3 (R-5) (R-6) (R-7) (R-8) (R-9) H3 ( R-10) (R-11) (R-12) (R-15) (R-16) (R-17) (R-18) (R-19) F3 (R-20) (R-21) CHs (R-22) (R-23) The reducing agent represented by the above general formula (1) can be prepared by a known method,
For example, Houben Peil, Mesosden der Organitsien Hemi, Band XI/2 (Houben
-Weyl, Methoden der Oraan
ischen Chemie, Band X I
/2) It can be synthesized according to the method described on pages 645-703.

On the other hand, the dye-donating substance is disclosed in JP-A No. 57-179840,
No. 58-58543, No. 59-152440, No. 5
No. 9-154445, a compound that releases a dye upon oxidation, a compound that loses the dye-releasing ability upon oxidation, a compound that releases a dye upon reduction, or a silver image only is obtained without containing a dye-providing substance. In some cases, reducing agents such as those described below can also be used.

For example, phenols (e.g. p-phenylphenol, p-methoxyphenol, 2.6-tert-butyl-p-cresol, N-methyl-p-aminophenol, etc.), sulfonamidophenols [e.g. 4-benzenesulfone Amidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4-benzenesulfonamidophenol, 2,6-dipromo 4-(
p-toluenesulfonamide) phenol, etc.], or polyhydroxybenzenes (e.g. hydroquinone, t
ert-butylhydroquinone, 2,6-dimethylhydroquinone, chlorohydroquinone, carboxyhydroquinone, catechol, 3-carboxycatechol, etc.)
, naphthols (e.g. α-naphthol, β-naphthol, 4-aminonaphthol, 4-methoxynaphthol, etc.), hydroxybinaphthyls and methylene bisnaphthols such as 1,1'-dihydroxy-2,2'-
Binaphthyl, 6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl, 6,6-sinitro 2,
2'-dihydroxy-1,1'-binaphthyl, 4.4'
-dimethoxy-1,1'-dihydroxy-2,2'-binaphthyl, bis(2-hydroxy-1-naphthyl)methane, etc.], methylene-sphenols [e.g. 1,1-bis(2-human ax-3 ,5-dimethylphenyl)-3
゜5.5-Trimethylhexane, 1,1-bis(2-hydroxy-3-tert-butyl-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-te)
rt-butylphenyl)methane, α-phenyl-α, α
-bis(2-hydroxy-3-tert-butyl-5-
methylphenyl)methane, 1.1-bis(2-hydroxy-3,5-dimethylphenyl)-2-methylpropane, 1.1,5.5-tetrakis(2-hydroxy-3,
5-dimethylphenyl)-2,4-ethylpentane, 2
．． 2-bis(4-hydroxy-3°5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3-methyl-5-tert-butylphenyl)propane, 2.
2-bis(4-hydroxy-3,5-di-tert-butylphenyl)propane, etc.], ascorbic acids, 3-
Mention may be made of pyrazolidones, pyrazolones, hydrazones and paraphenylenediamines.

These reducing agents can be used alone or in combination of two or more. The usage date of the reducing agent depends on the type of photosensitive silver halide used, the type of tirate silver salt, and the types of other additives, but it is usually used per mol of photosensitive silver halide. It ranges from 0.01 to 1500 mol, preferably from 0.1 to 200 mol.

Examples of the binder used in the heat-developable photosensitive material of the present invention include synthetic or natural polymers such as polyvinyl butyral, polyvinyl acetate, ethyl cellulose, polymethyl methacrylate, cellulose acetate butyrate, polyvinyl alcohol, polyvinylpyrrolidone, gelatin, and phthalated gelatin. One or more molecular substances can be used in combination. In particular, it is preferable to use gelatin or a derivative thereof in combination with a hydrophilic polymer such as polyvinylpyrrolidone or polyvinyl alcohol, and more preferably the following binder described in Japanese Patent Application No. 104249/1982.

This pineapple contains gelatin and vinylpyrrolidone polymer. The vinyl pyrrolidone polymer may be a homopolymer of vinyl pyrrolidone, polyvinyl and lolidone, or a copolymer of vinyl pyrrolidone with one or more other monomers copolymerizable (including graft copolymers). ). These polymers can be used regardless of their degree of polymerization. Polyvinylpyrrolidone may be substituted polyvinylpyrrolidone,
Preferred polyvinylpyrrolidone has a molecular weight of 1,000 to
400.000. Other monomers that can be copolymerized with vinylpyrrolidone include (meth)acrylic acid esters such as acrylic acid, methacrylic acid and their alkyl esters, vinyl alcohols, vinyl imidazoles, (meth)acrylic acid esters, and vinyl carboxylic acid. Examples include vinyl monomers such as alcohols and vinyl alkyl ethers, but it is preferable that polyvinylpyrrolidone accounts for a small composition ratio (both 20% (wt%, same hereinafter)). Preferred examples of such copolymers has a molecular weight of s
, ooo ~ 400,000.

The gelatin may be lime-treated or acid-treated, and may be ossein gelatin, big skin gelatin, hydrogelatin, or modified gelatin obtained by esterifying or phenylcarbamoylating these gelatins.

In the above binder, gelatin preferably accounts for 10 to 90% of the total binder amount, more preferably 20 to 60%, and vinylbiolidone accounts for 5 to 90%.
It is preferably 10 to 80%, more preferably 10 to 80%.

The binder may contain other polymeric substances,
Gelatin and molecules m1. mixture of polyvinylpyrrolidone with ooo~400,000 and one or more other polymeric substances, gelatin and molecular weight 5,000~400,
000 vinylpyrrolidone copolymer and one or more other polymeric substances is preferred. Other polymeric substances that can be used include polyvinyl alcohol, polyacrylamide, polymethacrylamide, polyvinyl butyral, polyethylene glycol, polyethylene glycol ester, or proteins such as cellulose derivatives, and polysaccharides such as starch and gum arabic. Examples include natural substances. These range from 0 to 85%, preferably from 0 to 7
It may be contained in an amount of 0%.

The above-mentioned vinylpyrrolidone polymer may be a crosslinked polymer, but in this case, it is preferable to crosslink it after coating it on the support (including the case where the crosslinking reaction progresses by leaving it to stand).

The amount of binder used is usually 0.000.
0.059 to 50 g, preferably 0.1 g to 10 g.

The support used in the heat-developable photosensitive material of the present invention includes:
For example, synthetic plastic films such as polyethylene film, cellulose acetate film and polyethylene terephthalate film, polyvinyl chloride, paper supports such as photographic base paper, printing paper, baryta paper and resin-coated paper, and the above-mentioned synthetic plus deck films reflect Examples include a support provided with a layer.

In addition to the above-mentioned components, various additives may be added to the heat-developable photosensitive material of the present invention, if necessary.

For example, as a development accelerator, U.S. Patent No. 3,220,8
No. 40, No. 3,531,285, No. 4.012,
No. 260, No. 4,060,420, No. 4,088
, No. 496, No. 4,207.392, specifications, RD
N 0.15733, same No. 15734, same N
0.15776, JP-A No. 56-130745, No. 56
Alkali release agents such as urea and guanidium trichloroacetate described in No. 132332, etc.,
12700, US Pat. No. 3,667,9
No. 59 (Non-aqueous polar solvent compound having D-Go+, -802+, -5o- groups, U.S. Patent No. 3,438,7
Meltformer-1 described in '76 U.S. Pat. No. 3,666
．． 477, and polyalkylene glycols described in JP-A-51-19525. Also, as a coloring agent,
For example, JP-A-46-4928, JP-A-46-6077,
49-5019, 49-5020, 49-
No. 91215, No. 49-107727, No. 50-2
No. 524, No. 50-67132, No. 50-67641
No. 50-114217, No. 52-33722,
No. 52-99813, No. 53-1020, No. 53-
No. 55115, No. 53-76020, No. 53-125
No. 014, No. 54-156523, No. 54-15
No. 6524, No. 54-156525, No. 54-1
No. 56526, No. 55-4060, No. 55-406
1, West German Patent No. 55-32015, West German Patent No. 2,140,406, West German Patent No. 2.147.063,
No. 2.220,618, U.S. Patent No. 3,080,2
No. 54, No. 3, 847.612, No. 3,782,
No. 941, No. 3.994.732, No. 4,123
, 282, No. 4,201.582, etc., such as phthalazinone, phthalimide, pyrazolone, quinazolinone, N-hydroxynaphthalimide, benzoxazine, naphthoxazinedione, 2.3- Dihydro-phthalazinedione, 2,3-dihydro-1,3-oxazine-2,4-dione, oxypyridine, aminopyridine, hydroxyquinoline, aminoquinoline, isocarbostyryl, sulfonamide, 2H
-1,3-benzothiazine-2,4-(3H)dione,
Benzotriazine, mercaptotriazole, dimerkabutotetrazabentalene, phthalic acid, naphthalic acid, phthalamic acid, etc., mixtures of one or more of these with imidazole compounds, and acids such as phthalic acid, naphthalic acid, etc. Alternatively, a mixture of at least one acid anhydride and a phthalazine compound, and further a combination of phthalazine and maleic acid, itaconic acid, quinolinic acid, gentisic acid, etc. can be mentioned. Also, JP-A-58-189
No. 628 and 5g-193460,
3-amino-5-mercapto-1,2,4-triazoles, 3-acylamino-5-mercapto-1,2,4
-Triazoles are also effective.

Furthermore, as an antifoggant, for example,
No. 7-11113, JP-A-49-90118, JP-A No. 49
-IG724, IG49-97613, IG50-1
No. 01019, No. 49-130720, No. 50-1
No. 23331, No. 51-47419, No. 51-574
No. 35, No. 51-78227, No. 51-10433
No. 8, No. 53-19825, No. 53-20923,
No. 51-50725, No. 51-3223, No. 51
-42529, 51-81124, 54-51
Publications such as No. 821 and No. 55-93149, as well as British Patent No. 1.455,271 and U.S. Patent No. 3,885.
, No. 968, No. 3,700,457, No. 4,13
No. 7,079, No. 4,138,265, West German Patent No. 2,617,907, etc., or oxidizing agents (for example, N-halogen acetamide, N-halogenosuccinimide, perchlorine and its salts, inorganic peroxides, persulfates, etc.),
Alternatively, acids and their salts (e.g., sulfinic acid, lithium laurate, rosin, diterpene acid, thiosulfonic acid, etc.), or sulfur-containing compounds (e.g., mercapto compound-releasing compounds, thiouracil, disulfide, simple sulfur, mercapto-1, 2,4-triazole, thiazolinthione, polysulfide compounds, etc.), others,
Examples include compounds such as oxazoline, 1,2°4-triazole, and phthalimide. Furthermore, thiol (preferably a thiophenol compound) compound described in JP-A-59-411636 is also effective as another antifoggant.

In addition, as other antifoggants, Japanese Patent Application No. 59-565
Hydroquinone derivatives described in No. 06 (e.g., di-t
-octylhydroquinone, dodecanylhydroquinone, etc.) or hydroquinone derivatives described in Japanese Patent Application No. 59-66380, and benzotriazole derivatives (e.g., 4-sulfobenzotriazole, 5-carboxybenzotriazole, etc.) are preferably used in combination. can.

In addition, as a stabilizer, a print-out preventive agent may be used at the same time, especially after processing, for example, as disclosed in JP-A No. 48-45228, JP-A No. 50-119624, and JP-A No. 50-120328.
Halogenated hydrocarbons described in No. 53-46020, specifically tetrabromobutane, trif-o-monitor, 2-bromo-2-tolylacetamide, 2
-Bromo-2-tolylsulfonylacetamide, 2-tribromomethylsulfonylbenzothiazole, 2.4-
Examples include bis(tribromomethyl)-6-methyltriazine.

Also, Japanese Patent Publication No. 46-5393, Japanese Patent Publication No. 50-54329
A post-treatment may be carried out using a sulfur-containing compound as described in No. 50-77034.

Furthermore, U.S. Patent No. 3,301,678;
506, 444, same No. 3.824.103, same No. 3
．． 844.788, as well as the isotonic stabilizer and precursor described in U.S. Patent No. 3.6.
No. 69.670, No. 4,012,260, No. 4.
It may contain activator stabilizer breaker etc. described in No. 060.420 Meishi et al.

Also, sucrose, NH4Fe (S04)2.12820
Water release agents such as
Heat development may be carried out by supplying water as in No. 132332.

In addition to the above-mentioned components, the heat-developable photosensitive material of the present invention may further contain various additives such as antihalation dyes, optical brighteners, hardeners, antistatic agents, plasticizers, and spreading agents, as well as coating aids. Agents etc. can be added.

When the heat-developable photosensitive material of the present invention is a color type, the dye-providing substance may be covered.

Dye-providing substances that can be used in the present invention will be explained below. The dye-donating substance may be any substance as long as it participates in the reduction reaction of the photosensitive silver halide and/or the organic silver salt used as necessary and can form or release a diffusible dye as a function of the reaction. Depending on their reaction form, negative-acting dye-donors act on a positive function (i.e., form a negative dye image when negative-working silver halide is used) and positive-acting substances act on a negative function. It can be classified as a dye-providing substance (that is, it forms a positive dye image when negative-working silver halide is used). Negative dye-donating substances are further classified as follows.

Margin below Release type compound　　Formation type compound Each dye-providing substance will be further explained.

Examples of the reducible dye-releasing compound include compounds represented by general formula (2).

General formula (2) % formula % In the formula, Car is a reducing substrate (so-called carrier) that is oxidized and releases a dye upon reduction of the photosensitive silver halide and/or the organic silver salt used as necessary. , Dy
e is a diffusible dye residue.

Specific examples of the above-mentioned reducing dye-releasing compounds include JP-A-57-179840, JP-A-58-116537, and JP-A No. 58-116537.
No. 9-60434, No. 59-65839, No. 59-7
No. 1046, No. 59-87450, No. 59-8873
No. 0, No. 59-123837, No. 59-165054
No., No. 59-165054, each memorandum, etc., and include, for example, the following compounds.

In the following margins, exemplified dye-donor substances OC+aHss (n) ClH,, (t) OCr&Hx3 (1n) Other reducing dye-releasing compounds include, for example, general formula (3).
Examples include compounds represented by:

General formula (3) In the formula, A1 and A2 each represent a hydrogen atom, a hydroxy group, or an amino group, and Dye is Dye represented by general formula (2).
is synonymous with Specific examples of the above compounds are given in JP-A-59-12
No. 4329.

As a coupled dye-releasing compound, general formula (4) is used.
Examples include compounds represented by:

General formula (4) % formula % In the formula, Cpl is an organic group (so-called coupler residue) that can react with the oxidized form of the reducing agent to release a diffusible dye, and J is a divalent bonding group. The bond between CO2 and J is cleaved by the reaction of the reducing agent with the oxidized product. nl is O
or 1, and Dye has the same meaning as defined in general formula (2). In addition, CD+ is RA with various ballast groups to make the coupled dye-releasing compound non-diffusible.
The ballast group is preferably an atom group having 8 or more carbon atoms (more preferably 12 or more), or a hydrophilic group such as a sulfo group or a carboxy group, depending on the form of the photosensitive material used. group, or a group having both 8 or more (more preferably 12 or more) carbon atoms and a hydrophilic group such as a sulfo group or a carboxy group. Another particularly preferred ballast group can include polymer chains.

Specific examples of the compound represented by the above general formula (4) include JP-A-57-186744 and JP-A-57-122596.
No. 57-160698, No. 59-174834, No. 57-224883, No. 59-159159,
They are listed in C2 of each specification of Japanese Patent Application No. 59-104901, and include, for example, the following compounds.

Exemplary dye-donor substances ■ OCR.

■ As a coupling dye-forming compound, general formula (5) is used.
Examples include compounds represented by:

General formula (5) % formula %) In the formula, CD2 is an organic group that can react (coupling reaction) with the oxidized product of the reducing agent to form a diffusible dye (
F represents a divalent bonding group, and B represents a ballast group.

The coupler residue represented by C112 preferably has a molecular weight of 700 or less, more preferably 500 or less, for the sake of diffusibility of the dye formed.

Further, the ballast group is preferably the same as the ballast group defined in general formula (4), and particularly has 8 or more (more preferably 12 or more) carbon atoms and a hydrophilic group such as a sulfo group or a carboxy group. Groups having both are preferred, and polymer chains are more preferred.

The coupled dye-forming compound having a polymer chain is preferably a polymer having a repeating unit derived from a monomer represented by general formula (6).

General formula (6) % formula %) In the formula, CI)2 and F have the same meanings as defined in general formula (5), Y represents an alkylene group, arylene group or aralkylene group, and 2 is 0 or represents 1 and 2 is 2
L represents an ethylenically unsaturated group or a group having an ethylenically unsaturated group.

Specific examples of the coupled dye-forming compounds represented by general formulas (5) and (6) include JP-A-59-1243
No. 39, No. 59-181345, patent application No. 58-109
No. 293, No. 59-179657, No. 59-18
No. 1604, No. 59-182506, No. 59-18
No. 2507, for example, the following compounds are listed.

16M33 ■ C,8H,.

Polymer 0H x: 60% by weight y: 40% by weight @CH3 ) and (6), CI
)+ or CO2, a group represented by the following general formula is preferred.

General formula (7) General formula (8) General formula (wa) General formula (lO) General formula (/3)
General ceremony (/meeting) General ceremony (/9)
General formula (/6) In the margin formula below, R7, Rg, R? and R'' are a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an acyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, a sulfamoyl group, and an acyloxy group, respectively. , amiLL represents an alkoxy group, aryloxy group, cyano group, ureido group, alkylthio group, arylthio group, carboxyl group, sulfo group or a heterocyclic residue, which can further be hydroxyl group, carboxy group, sulfo group, alkoxy group, cyam L may be substituted with a nitro group, an alkyl group, an aryl group, an aryloxy group, an acyloxy group, an acyl group, a sulfamoyl group, a carbamoyl group, an imide group, a halogen atom, or the like.

These substituents are selected depending on the purpose of CD+ and Cβ2, and as mentioned above, in <C1)+, one of the substituents is preferably a ballast group, and in CL2, it is preferable to improve the diffusivity of the dye formed. The number of molecules to increase is 100
Hereinafter, the number of substituents is preferably selected to be 500 or less.

As a positive dye-donating substance, for example, the following general formula (1
There is an oxidizable dye-releasing compound represented by 7).

General formula (17) In the formula, Wl represents a collection of atoms necessary to form a quinone ring (which may have a substituent on this ring),
R'' represents an alkyl group or a hydrogen atom, R'3 represents an oxygen atom or r represents O or 1, and Dye has the same meaning as defined in general formula (2). A specific example of this compound is JP-A-59-
It is described in specifications such as No. 166954 and No. 59-154445, and includes, for example, the following compounds.

Exemplary dye-donor substance S02 CH3 ■ CH3 Shitsuko='(" [phase] ? As another positive dye-donor substance, the following general formula (18)
There are compounds that lose their dye-releasing ability when oxidized, such as the compound represented by:

General formula (18) In the formula, W2 represents a collection of atoms necessary to form a benzene ring (which may have a substituent on the ring), and R''
, r , E, DV? ! has the same meaning as defined in general formula (17). A specific example of this compound is JP-A No. 5
It is described in specifications such as No. 9-124329 and No. 59-154445, and includes, for example, the following compounds.

Illustrative dye-donating substance■ Still another positive dye-donating substance is given by the general formula (
Examples include compounds represented by 19).

General formula (19> In the above formula, W2, R'', Dye are general formula (19)
It has the same meaning as defined in 8).

Specific examples of this compound are described in JP-A-59-154445, etc., and include the following compounds.

Exemplary dye-providing substance = [phase] Q General formula (2), (3), (4), (17 (78)
The residue of the diffusible dye represented by Dye in (19) will be explained in further detail. The residue of the diffusible dye preferably has a molecular solidity of 800 or less, more preferably 600jJ or less, for the sake of the diffusivity of the dye, such as an azo dye,
Examples include residues of azomethine dyes, anthraquinone dyes, naphthoquinone dyes, styryl dyes, nitro dyes, quinoline dyes, carbonyl dyes, and phthalocyanine dyes. These residual dye bases may be in a temporary short wave form that can be multicolored during thermal development or transfer. In addition, these dye residues are used for the purpose of increasing the light resistance of images, for example, in Japanese Patent Application Laid-Open No. 59-4
Chelatable dye residues described in No. 8765 and No. 59-124337 are also preferred.

These dye-providing substances may be used alone or in combination of two or more. Its usage is not limited, and it can be used depending on the type of dye-providing substance, single use, or 2f! It may be determined depending on whether the above-mentioned combinations are used, or whether the photographic constituent layer of the light-sensitive material of the present invention is a single layer or a multilayer of two or more layers, etc., but for example, the amount used is 0.005Q to 50 per volt. (1, preferably 0.19 to 10 g can be used.

The dye-providing substance used in the present invention can be incorporated into the photographic constituent layer of the heat-developable light-sensitive material using any method. , tricresyl bosphate, etc.),
Ultrasonic dispersion, or alkaline aqueous solution (e.g.
It can be used by dissolving it in a 10% aqueous solution of sodium hydroxide, etc., and then neutralizing it with a mineral acid (e.g., hydrochloric acid or nitric acid, etc.), or by dissolving it in an aqueous solution of an appropriate polymer (e.g., gelatin, polyvinyl butyral, polyvinyl pyrrolidone, etc.). etc.) using a ball mill and then used.

Various exposure means can be used for the heat-developable photosensitive material of the present invention. The latent image is obtained by imagewise exposure to radiant radiation, including visible light. In general, light sources commonly used for color printing, such as tungsten lamps, mercury lamps, xenon lamps, laser beams, CRT beams, etc., can be used as the light source.

As the heating means, all methods applicable 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, passing through a high-temperature atmosphere, etc. Alternatively, it is also possible to use high frequency heating, or furthermore, to provide a conductive layer in the photosensitive material of the present invention or in the image receiving member for thermal transfer, and to utilize Joule heat generated by electricity or a strong magnetic field. There are no particular restrictions on the heating pattern, including methods of preheating (breheating) and then reheating.
Continuous rise at high temperature for a short time or low temperature for a long time,
Although descending or repeated heating or even discontinuous heating is possible, a simple pattern is preferred. Alternatively, a method in which exposure and heating proceed simultaneously may be used.

When the heat-developable photosensitive material of the present invention is a black-and-white type that forms a silver image, the heat-developable photosensitive material is usually exposed at 80°C after imagewise exposure.
1 second to 240 seconds, preferably 1.5 seconds to 12 seconds at a temperature range of ~250°C, preferably 100°C to 200°C.
Developed by heating for 0 seconds. Also, before exposure,
Preheating may be performed in a temperature range of 0°C to 200°C.

The heat-developable photosensitive material on which a silver image has been formed can be displayed and stored as is, but if a longer period of storage is required, unreacted silver salt is preferably removed.

Removal of unreacted silver salts can be carried out using bleach baths, fixing baths, or bleach-fixing baths (for example, JP-A-5
No. 0-54329, No. 50-77034, No. 51-3
28, No. 51-80226, etc.), but Japanese Patent Application Laid-open No. 59-136733, Research Disclosure No. 0.16407, No. 1640
A bleach-fixing sheet as described in No. 8, No. 16414 of the same may also be used.

In addition, when the heat-developable photosensitive material of the present invention is a color type using a dye-donating substance, the photosensitive layer side of the photothermographic material of the present invention of the photothermographic material of the present invention is in a stacked relationship with the photosensitive layer side of the photothermographic material of the present invention, which will be described later. at a temperature range of usually 80°C to 200°C, preferably 120°C to 170°C, for 1 second to 1 second.
By heating for 80 seconds, preferably from 1.5 seconds to 120 seconds, the image is transferred to the image receiving member simultaneously with color development.

Moreover, you may perform preheating in the temperature range of 70 degreeC - 180 degreeC before exposure.

The image receiving member used in the present invention only needs to have the function of receiving the dye released or formed by thermal development, and may be a mordant used in dye diffusion transfer type light-sensitive materials or JP-A-57-2
The glass transition temperature described in No. 07250 etc. is 40'C
As mentioned above, it is preferable to form the heat-resistant organic polymer material at 250° C. or lower.

Specific examples of the mordant include nitrogen-containing secondary and tertiary amines, nitrogen-containing heterocyclic compounds, quaternary cationic compounds thereof, U.S. Pat.
No. 4,430, No. 3,148,061, No. 3,756
, 814 and vinyl pyridinium thione polymers, polymers containing dialkylamino groups as disclosed in U.S. Pat. No. 2,675,316, and polymers containing dialkylamino groups as disclosed in U.S. Pat. No. 2,882.156. Aminoguanidine derivatives, which have been disclosed in Japanese Patent Application Laid-open No.
Covalently reactive polymers described in U.S. Pat. No. 3,625,694 and U.S. Pat.
．． 096, British Patent No. 1,277.453, British Patent No. 2,
No. 011,012, a mordant capable of crosslinking with gelatin, etc.; U.S. Pat. No. 3,958,995;
, No. 721,852 and No. 2,798.063) Water-free sol-type mordant, JP-A-50-61228
Water-insoluble mordants disclosed in US El 4t Permit No. 3.788.855, West German Patent Application (OLS) No. 2.843.320, JP-A-53-30328, JP-A-52-155528, 53-125, 53-
No. 1024, No. 54-74430, No. 54-1247
No. 26, No. 55-22766, U.S. Patent No. 3.642
．． No. 482, No. 3.488.706, No. 3,55
No. 7,066, No. 3.271,147, No. 3,271
, No. 148, Special Publication No. 55-29418, No. 56-36
No. 414, No. 57-12139, R[) 1204
5 (1974), various mordants can be mentioned.

Particularly useful mordants are polymers containing ammonium salts,
Polymer containing quaternary amino groups as described in US Pat. No. 3,709,690. Examples of polymers containing ammonium salts include polystyrene-N,N,N-tri-n-hexyl-N-vinylbenzylammonium chloride, and the ratio of styrene and vinylbenzylammonium chloride is 1:4 to 4:1; Preferably the ratio is 1:1.

A typical image-receiving layer for dye diffusion transfer is obtained by coating a polymer containing an ammonium salt mixed with gelatin on a support.

As an example of the heat-resistant polymeric substance, the molecule ffi
Polystyrene having a carbon number of 2,000 to 85,000, polystyrene derivatives having substituents having 4 or less carbon atoms, polyacetals such as polyvinylcyclohexane, polyvinylbenzene, polyvinylpyrrolidone, polyvinylcarbazole, polyallylbenzene, polyvinyl alcohol, polyvinyl formal, and polyvinyl butyral. , polyvinyl chloride, chlorinated polyethylene, polytrichloride fluoroethylene,
Polyacrylonitrile, poly N, N-dimethylacrylamide, polyacrylate with p-cyanophenyl group, pentachlorophenyl group and 2,4-dichlorophenyl group, polyacrylchloroacrylate, polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, Polyisopropyl methacrylate, polyisobutyl methacrylate, poly tert-
Polyesters such as butyl methacrylate, polycyclohexyl methacrylate, polyethylene glycol dimethacrylate, poly-2-cyano-ethyl methacrylate, polyethylene terephthalate, polycarbonates such as polysulfone, bisphenol A polycarbonate, polyanhydrides, polyamides, cellulose acetates, etc. can be given. In addition, the Polymer Handboo 2nd Edition (Polymer Handboo
k 2nd ed, ), G.A. Brandrup, E.H. InmargtfQ (J, 3r
andrup, E, H, l mergu
t), John Wiley & Sons Publishing (J
Also useful are synthetic polymers with a glass transition temperature of 40° C. or higher, such as those described in Wi. Iey & 3 ons). These polymeric substances may be used alone or in combination of two or more as a copolymer.

Particularly useful polymers include cellulose acetates such as triacetate and diacetate, heptamethylene diamine and terephthalic acid, fluorene dipropylamine and adipic acid, hexamethylene diamine and diphenic acid,
Examples include polyamide made from a combination of hexamethylene diamine and isophthalic acid, polyester made from a combination of diethylene glycol and diphenylcarboxylic acid, bis-p-carboxyphenoxybutane and ethylene glycol, polyethylene terephthalate, polycarbonate, and vinyl chloride. These polymers may be modified. For example, polyethylene terephthalate using cyclohexane dimetatool, isophthalic acid, methoxypolyethylene glycol, 1,2-dicarpomethoxy4-benzenesulfonic acid, etc. as a modifier is also effective. Among these, 1) preferably includes a layer made of polyvinyl chloride as described in Japanese Patent Application No. 58-97907, and a layer made of polycarbonate and a plasticizer as described in Japanese Patent Application No. 58-128600.

The above polymer is used by dissolving it in a suitable solvent and coating it on a support to form an image receiving layer, or by laminating a film-like image receiving layer made of the above polymer on a support, or by coating it on a support. It is also possible to constitute the image-receiving layer by a member (for example, a film) made of the above-mentioned polymer alone (also used as an image-receiving layer support).

Furthermore, the image-receiving layer can also be constructed by providing an opaque layer (reflective l!>) containing titanium dioxide or the like dispersed in gelatin on the image-receiving layer on a transparent support. A reflective color image is obtained by viewing the image from the transparent support side of the image-receiving layer.

In the following margin [Specific Examples of the Invention] The present invention will be specifically described below with reference to Examples, but the embodiments of the present invention are not limited to these.

Example 1 [Preparation of silver bromide emulsion] Silver bromide emulsion A for comparison was prepared by the following method. 5
At 0°C, JP-A-57-92523, JP-A-57-9
Using the mixer shown in the specification of No. 2524, 20 g of ossein gelatin, 1000 d of distilled water, and ammonia were dissolved in the (A) solution containing 5 oov+2 of an aqueous solution containing 11 moles of potassium bromide (B). Liquid and Nitrous M! Il!
1 mol and an aqueous solution <C> containing 500 iR of ammonia were simultaneously added while keeping 1) A(+ constant. The shape and size of the emulsion grains to be prepared were determined by the pH, 1) A(
It was adjusted by controlling the addition rate of liquids I and (B) and liquid (C). A silver bromide emulsion was thus prepared.

The obtained silver halide grains had an average grain size of 0.3/l m
The medium-dispersed bamboo contained 8% octahedral particles.

This emulsion was washed with water and desalted. Emulsion yield is 800m12
Met.

[Preparation of Silver Iodobromide Emulsion] Silver halide emulsions BSC and D containing three types of photosensitive silver halides having different silver iodide contents were prepared by the following method.

At 50°C, JP-A-57-92523, JP-A-57-92523;
20 g of ossein gelatin, 1000112 distilled water, and ammonia were dissolved using the mixing stirrer shown in the specification of No. 92524. 4.98g,
Potassium bromide 131g, potassium iodide 6 for emulsion C
．． 64 (1, potassium bromide 1319, potassium iodide for emulsion 11.62 C1, potassium M 131!
500 d of solution (B) containing the aqueous solution contained in step I) and 500 d of solution (C) containing 1 mol of silver nitrate and ammonia were simultaneously added while keeping the pAg constant.

:! ! The shape and size of l-cleaved emulsion grains are p)-1,r
)AQ and the addition speed of liquids (B) and (C) are controlled 1t-
Adjusted by J. In this way, emulsions having the same regular octahedral shape but different silver iodide contents were prepared. (The monodispersity of each emulsion was 9%) These emulsions were washed with water and desalted.

The yield of each emulsion was 800 g.

The average grain size and silver iodide content of each comparative silver halide emulsion A to D prepared in this manner are shown in Table 1 below.

Table-1 Emulsion Average grain size Silver iodide content A (comparison)
0.3 μm0 B (comparison) 0.3 μm 3 mol% C (invention) 0.3 μm 4 mol% D (invention) 0
．． 3 μm 7 mol% [Preparation of core/shell type silver iodobromide emulsion] Three types of core/shells with different silver iodide contents and average grain sizes were prepared in emulsions E and F.
, G were prepared by the following method.

At 50°C, JP-A-57-92523, JP-A-57-92523;
Potassium iodide and potassium bromide were added to solution (A) in which 20 g of ossein gelatin, 100 g of distilled water (hN) and ammonia were dissolved using the mixer shown in the specification of No. 92524. Potassium chloride 11.62 (
J, potassium bromide 1311; l, for emulsion E, potassium iodide 11.62 (1, potassium bromide 131 g,
For emulsion G, an aqueous solution (B) containing 33.2 Q of potassium iodide and 119 g of potassium bromide (500 g) and an aqueous solution containing 1 mole of silver nitrate and ammonia (500 g) were used.
0 ml of solution (C) was added at the same time while keeping DAσ constant. The shape and size of the particles of the core emulsion to be prepared are determined by the pH,
l) Adjustment was made by controlling the addition rate of Ag and liquids (B) and (C). In this way, core emulsions having the same regular octahedral shape but different average grain sizes and silver iodide contents were prepared. (The monodispersity of each emulsion was 8%) Next, using the silver halide grains obtained above as cores, the same method as above was applied (however, each potassium iodide of the shell solution (B) Concentration and potassium bromide concentration for emulsion E is potassium iodide 3.321;l, potassium bromide 131g, for emulsion E potassium iodide 3.3291 potassium bromide 131
(1. For emulsion G, potassium iodide 3.32 Q, potassium bromide 1310) is coated with core/shell type halogenated octahedral particles with the same regular octahedral shape but different average grain sizes and silver iodide contents. A silver emulsion was prepared.

Each of these emulsions was washed with water and desalted. Yield 0 for each emulsion
was 800 d.

The average grain size and silver iodide content of each core/shell type silver halide emulsion E to G subjected to UAlj in this way are shown in the table below.
Shown in 2.

Table 2: Preparation of r-organic silver salt dispersion-1] Silver 28.80% of 5-methylbenzotriazole obtained by reacting 5-methylbenzotriazole and silver nitrate in a water-alcohol mixed solvent and poly(N-vinyl pyrrolidone) 16.0 (1) and 4-sulfobenzotriazole sodium salt 1.33Q were dispersed in an alumina ball mill and adjusted to pH 5.5 to 200d.

[Preparation of photosensitive silver halide dispersion] The silver halide emulsions No and D prepared above were mixed with the compound EJf! of the present invention. l”J dye (I) and sensitizing dye (■
)] in the presence of the combinations shown in Table 3 below and 4-hydroxy-6-methyl-1,3,3a,7-titrazaindene, and sulfur sensitization treatment with sodium thiosulfate to produce photosensitive halogenated products with the following composition: A silver emulsion dispersion was prepared.

Photosensitive silver halide (in terms of silver) 381 g Gelatin 85/28201 g [Preparation of dye-donor dispersion-1] Exemplary dye-donor substances @3s, sg and 5.0 OIJ of the hydroquinone compound below were mixed with 200.0 g of ethyl acetate. (Dissolved in 2, Alkanol XC (manufactured by DuPont) 5-fold ffi
% aqueous solution 124d phenylcarbamoylated gelatin (Rouslow Company, type 17819P C) 30.50% aqueous gelatin solution containing 720% and dispersed with an ultrasonic homogenizer, and after distilling off the ethyl acetate I) 85.5
It was set to 7951112.

Hydroquinone Compound H [Preparation of Reducing Agent Dispersion-1] Exemplary Reducing Agent (R-N) 23.3<1, Below Development Accelerator 1.10 (], Poly(N-vinylpyrrolidone) 14
．． 6g of the following fluorine-based surfactants o and sog were dissolved in water, and the p+ was adjusted to 5.5 to 250-.

Kawaden accelerator CH, -CH= C)l-L Surfactant NLO3S-GH-COOCH2 (CF, CF2) tr
HCHz-COOCHz (CFzcF7), nH (susceptibility,
24TSlt B di[Preparation of heat-developable photosensitive material-1] 12.5d of the organic silver salt dispersion-1 prepared above, 6.00i of the above-mentioned silver halide dispersion, and 6.00i of the dye-providing substance dispersion-1 39.8 叡, 12.5 m of reducing agent dispersion-1, &
The hardener solvent (tetra(vinylsulfonylmethyl)methane and taurine are reacted in a ratio of 1=1 (lta ratio), and then dissolved in a 1% aqueous solution of phenylcarbamoylated gelatin. ) methane is 31f1%. ) is 2.50d,
After adding 3.80!11 of polyethylene glycol 300 (manufactured by Kanto Kagaku Co., Ltd.) as a heat solvent, it was placed on a photographic polyethylene terephthalate film with a thickness of 180 μm that had been undercoated, so that silver m was 1.76 g/v. A protective layer consisting of a mixture of the phenylcarbamoylated gelatin and poly(N-vinylpyrrolidone) is applied on top of the grain.
Layers were provided.

[Preparation of image receiving member-1] Polyvinyl chloride (n -1,1
A tetrahydrofuran solution of 00, Wako Tsumugi Yakuhin) was applied so that the polyvinyl chloride was 12a/f.

The photothermographic material was exposed to 1,600C, M, and S through a step wedge, and together with the image receiving member, the photothermographic material was exposed to 9FM<developer module 27.
After heat development was carried out at 150°C for 1 minute at 7.3M Co., Ltd., the photothermographic material and the image receiving member were quickly removed, and a magenta step wedge was formed on the polyvinyl chloride surface of the image receiving member. A negative image was obtained.

On the other hand, a photosensitive material using the same exposure method was developed at 20°C for 3 minutes using a developer having the composition shown below, followed by stopping, fixing, washing with water, and drying to form a black and white image.

Table 3 shows the sensitivity of the black and white image and the sensitivity of the magenta transferred image obtained by heat development in relative values.

The sensitivity of the black and white image of comparative sample No. 9 was set to 100, and the sensitivity was determined at the point of fog +0.2.

[Developer composition] Metol 2g anhydrous sodium sulfite 40 (]Hydroquinone
49 Sodium carbonate monohydrate
28 (potassium monobromide
Add 1g of water to make 12.

As is clear from Margin Table 3 below, only the sensitizing dye (I) or only the sensitizing dye (n) among the compounds of the present invention is added to the silver halide emulsion containing the photosensitive silver halide grains of the present invention. Compared to the comparative samples (No. 9 to 12) using the compound of the present invention, the samples (No. 1 to 8) using a combination of the sensitizing dye (I> and the sensitizing dye (II)) of the compound of the present invention had It can be seen that the desensitization caused by heat development is small, and the sensitizing effect on photosensitive silver halide is also good, making it a highly sensitive heat-developable photosensitive material.

Example 2 The procedure of Example 1 was repeated except that the combination of the silver halide emulsion shown in Table 4 below and the compound of the present invention [sensitizing dye (I) (+3 and sensitizing dye (■))] was used. A photosensitive silver halide dispersion was prepared.

A magenta transfer image and a black and white image were obtained by preparing a heat-developable photosensitive material and an image receiving member, exposing and developing the heat-developable photosensitive material in the same manner as in Example 1.

Table 4 shows the sensitivity of black and white images and magenta transferred images in relative values. However, the sensitivity of the black and white image of sample No. 23 was set to 100.
The sensitivity was determined at fog+02. Furthermore, the maximum temperature (Dmax) shown is that determined for a magenta transfer image by color thermal development.

As is clear from Margin Table 4 below, a comparative sample (No. 14.15.17.18.20 ．．
21, 23, 24, 26, 27, 29, and 30), a significant decrease in sensitivity is observed due to color thermal development.

Furthermore, even when the sensitizing dye (I) and the sensitizing dye (I) are used in combination, the sensitizing dye < I) and (
II) and further using the photosensitive silver halide of the present invention (No. 19.22.25.2)
In No. 8), the desensitization caused by color heat development was improved, and it was found that the material was a good heat-developable photosensitive material. Furthermore, it can be seen that among the photosensitive silver halides of the present invention, core/shell type photosensitive silver halides exhibit particularly good results with little desensitization. On the other hand, even though core/shell type photosensitive silver halide is used, the comparative sample (No. 31), which is outside the scope of the present invention with a grain size of 0.5 μm, has a high sensitivity, but the maximum density of the Mazenk transfer image is low. It can be seen that it is too small to be put to practical use.

Example 3 Compounds of the present invention [sensitizing dye (1) and sensitizing dye (■)
] A photosensitive silver halide dispersion was prepared in the same manner as in Example 1 except that the combinations shown in Table 5 below were used.

[Preparation of dye-providing substance dispersion-2] Exemplary dye-providing substance ■30. Og to tricresyl phosphate 30. 46 geladine aqueous solution containing the same surfactant as in Example 1 and dissolved in 90.0 d of ethyl acetate.
(After mixing with hQ and dispersing with an ultrasonic homogenizer, ethyl acetate was distilled off and water was added to make 500 t12.

[Preparation of heat-developable photosensitive material 1-2] Silver halide emulsion dispersion 40.01Q, 25.0d of organic silver salt dispersion-1 of Example 1, 50.0d of dye-providing substance dispersion-2 and 4.20 g of polyethylene glycol 300 (manufactured by Kanto Kagaku Co., Ltd.) as a heat solvent.
, 10% by weight methanol solution of 1-phenyl-4,4-dimethyl-3-pyrazolidone 1.5 - Same hardener as in Example 1 3. 1 of OOd and guanidine trichloroacetic acid
Add 0% water-alcohol solution 20.0.17,
A 180 μm thick photographic polyethylene terephthalate film was coated with 2.5 (1 g/l)
', and the test FINo shown in Table-5 below,
Twelve kinds of heat-developable photosensitive materials-2, Nos. 32 to 43, were prepared.

[Preparation of Image Receiving Member-2] The following layers were sequentially coated on a 100 μm thick transparent polyethylene terephthalate film.

(1) Layer made of polyacrylic acid. (7,oOMf)(
2> Layer consisting of cellulose acetate. (4,OOMf)(
3) Styrene and N-benzyl-N,N-dimethyl-N-
A layer consisting of a 1:1 copolymer of (3-maleimidopropyl)ammonium chloride and gelatin.

(comm combination 3.00(]/w't'5 chin 3.00
! +/f) The above 12 kinds of photothermographic materials-2 were exposed to 1,600C, M, S through a step wedge, heated for 1 minute on a heat block at 150°C, and then immersed in water. Glue together with image receiving member-2, 50
C. and 500 g to 800 g/Cf for 30 seconds and then quickly peeled off, a yellow step wedge negative image was obtained on the surface of the image receiving member.

On the other hand, the same exposed photosensitive material was subjected to wet black-and-white development processing in the same manner as in Example 1 to obtain a black-and-white image.

Table 5 shows the relative sensitivity of the black and white image and the yellow transferred image obtained by heat development. However, the sensitivity of the black and white image of sample No. 40 is assumed to be 100, and the sensitivity is determined by fog + 0.2.
It was set as a point.

As is clear from Margin Table 5 below, even in heat-developable photosensitive materials in which a dye-providing substance is used in place of a reducing dye substance, the silver halide emulsion containing the photosensitive silver halide grains of the present invention is Comparative samples (No. 40 to 4) using only sensitizing dye (I) or only sensitizing dye (II) among the compounds of the invention
3), a sample using a combination of sensitizing dye (I) and sensitizing dye (I) of the compound of the present invention (No. 32)
It can be seen that Samples 39) to 39) exhibit less desensitization due to heat development and also have a good sensitizing effect on photosensitive silver halide, indicating that they are highly sensitive heat-developable photosensitive materials.

Example 4 In Example 3, the silver halide emulsion shown in Table 6 below and the compound of the present invention [sensitizing dye (I) and sensitizing dye (■
)] A photosensitive silver halide dispersion was prepared in the same manner except that the combination was changed.

A yellow transfer image and a black and white image were obtained by preparing a heat-developable photosensitive material and an image receiving member, exposing and developing the heat-developable photosensitive material in the same manner as in Example 3.

Table 6 shows the sensitivity of the black and white image a3 and the yellow transferred image in relative values. However, the sensitivity of the black and white image of test 11 No. 54 is set to 1.
00, and the sensitivity was determined by fog + 0.2. Furthermore, the maximum density ([)max) shown is that determined for a yellow transferred image by color thermal development.

As is clear from Margin Table 6 below, a comparative sample (No. 45.46.48.49.51) in which the sensitizing dye (I) and the sensitizing dye (If), which are compounds of the present invention, are not used in combination ．．
52, 54, 55, 57, 58, 60), a significant decrease in sensitivity due to color thermal development is observed.

Furthermore, even when the sensitizing dye (I) and the sensitizing dye (II) are used in combination, the sensitizing color jH (I>
and (II), and further used the photosensitive silver halide of the present invention (No. 50.53.56)
．． No. 59) was found to have improved desensitization due to color heat development and was a good heat-developable photosensitive material. Furthermore,
It can be seen that among the photosensitive silver halides of the present invention, core/shell type photosensitive silver halides exhibit particularly good results with little desensitization. On the other hand, even with core/shell type photosensitive silver halide, a comparative sample (No. 62>, which is outside the scope of the present invention with a grain size of 0.5 μm, has a high sensitivity but a maximum density of a yellow transferred image. It can be seen that it is too small to be put to practical use.

Claims (1)

[Scope of Claims] At least one of the silver halide emulsion layers of the heat-developable photosensitive material contains a photosensitive halide having a silver iodide content of 4 to 40 mol% and an average grain size of 0.4 μm or less. 1. A photothermographic material characterized by containing silver particles and a combination of at least one compound represented by the following general formula (I) and at least one compound represented by the following general formula (II). General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ In the formula, R_1 represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group, and R_2 and R_3 each represent an alkyl group. Y_1 and Y_2 each represent a sulfur atom or a selenium atom. Z_1, Z_2, Z_3 and Z_4 each represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an alkoxycarbonylamino group, an acylamido group, an aryl group, an alkyl group or a cyano group. However, Z_1 and Z_2 and/or Z_3 and Z_4 may be connected to each other to form a ring. X_1^■ represents an anion, m
represents an integer of 0 or 1. General formula (II) ▲There are numerical formulas, chemical formulas, tables, etc.▼ In the formula, R_4, R_5, R_6 and R_7 each represent a hydrogen atom or an alkyl group. Y_3 represents a nitrogen atom, a sulfur atom, or a selenium atom, but when Y_3 is a sulfur atom or a selenium atom, it does not have the above R_4. Z_5, Z_6, Z_7 and Z_8 are each a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, an acyl group, an acylamido group, an acyloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylamino group, an aryl group, an alkyl group, Represents a cyano group or a sulfonyl group. however,
Z_5 and Z_6 and/or Z_7 and Z_8 may be connected to each other to form a ring. X_2^■ represents an anion, and n represents an integer of 0 or 1.