JPS60195541A - Heat developable photosensitive material - Google Patents

Abstract

PURPOSE:To obtain a heat developable photosensitive material which permits formation of an image by heating in the state of contg. no water and is fast in the forming speed of a dye image by forming hybrid silver halide of a polyhedral crystal of silver iodide and by epitaxy junction to said polyhedral crystal so that epitaxy silver halide exists on the crystal plane of the silver iodide at a prescribed area ratio. CONSTITUTION:A hybrid silver halide crystal is formed of a polyhedral crystal of silver iodide and by epitaxy junction of at least one kind of silver chloride, silver chlorobromide, silver chloroiodide, silver iobromide or silver chloroiobromide. Part of the silver iodide as a substrate crystal is polyhedral radiation sensitive silver iodide having at least 0.1mum min. average grain size and at least 25% of the polyhedral crystal of such silver iodide contains substantially no epitaxy silver halide. Silver halide is limited to <=75mol% of the entire part. The amt. of the silver halide in the hybrid crystal is 1-50mol% of the entire hybrid silver halide. The optimum amt. thereof depends on applications of a photographic emulsion, etc. and the development of the silver halide is adjustable by adjusting the size of the crystal.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a heat-developable photosensitive material. More particularly, the present invention relates to a photosensitive material that can form a dye image by heating in a substantially water-free state. (Background Art) Photography using silver halide has been the most widely used method since it has superior photographic properties such as sensitivity and 1uII resolution compared to other photographic methods such as electrophotography and diazo photography. It's here. In recent years, a technology has been developed that allows images to be obtained easily and quickly by changing the image forming method for photosensitive materials using silver halide from the conventional wet processing using a developing solution to a dry processing using heating, etc. has been developed. Heat-developable photosensitive materials are well known in the art, and for information about heat-developable photosensitive materials and their processes, see, for example, [Basics of Photographic Engineering ff1j (Published by Corona Publishing, 1979), p. 553~
Page 555, “Video Information J (published in April 1978) 4
0 pages, rNeblets Handbook of Photo
ography and reprography 7th Ed, J(Van
No5trand Reinhold Company)
pages 32-33 of U.S. Pat. No. 3,152,904,
3,301,678, 3,392,020, 3.457°075, British Patent No. 1,131,
No. 108, No. 1,167.777, and Research Disclosure magazine, June 1978, pages 9 to 15. However, the method of obtaining an image in a dry state as described above has the drawbacks of lower sensitivity and longer time required to form a dye image than a method of processing in a wet state. This drawback can be improved by using organic silver salt oxidizing agents, etc., but this is not sufficient in view of the recent demands for higher sensitivity and faster photographic processing, and The concentration was also not sufficient. As a result of intensive research to solve the drawbacks of the conventional technology, the present inventors have found that when a hybrid silver halide crystal formed by epitaxy bonding is used in a heat-developable silver halide photosensitive material, the image forming speed is extremely high. It has been found that this is particularly noticeable in the case of heat-developable photosensitive materials that have a dye-donating substance that reacts with photosensitive silver halide to release a hydrophilic dye when heated. Ta. (Object of the Invention) Therefore, the first object of the present invention is to provide a photosensitive material that maintains the conventional sensitivity and improves the maximum density of an image, which can be imaged by heating in a substantially water-free state. It is an object of the present invention to provide a photothermographic material capable of forming a photothermographic material. A second object of the present invention is to provide a heat-developable photosensitive material that has a fast dye image formation rate and is suitable for rapid camera work. (Structure of the Invention) The features of the present invention include (i) a polyhedral crystal of silver iodide;
The polyhedral crystals of silver iodide include silver chloride, silver chlorobromide, silver chloroiodide,
A hybrid silver halide crystal formed by epitaxially bonding at least one crystal selected from silver iodobromide or silver chloroiodobromide, wherein at least 25% of the crystal faces of the silver iodide are is a photosensitive tin halide in which epitaxial silver halide is not substantially present and epitaxial silver halide accounts for 75 mol% or less of the total mixed tin halide, (i) a binder, and (i) when the photosensitive silver halide is reduced. This was achieved by a heat-developable photosensitive material having a dye-donating substance that releases or forms a hydrophilic dye in an imagewise manner in response to or inversely to this. (Disclosure of the Invention) In the present invention, a silver halide photographic emulsion containing epitaxially hybridized tin halide crystals can liberate a relatively large amount of iodide ions when developed. Photographic effects due to the release of oxide ions can be effectively utilized. Furthermore, in photographic emulsions containing epitaxial silver halide and silver iodide, as described below, epitaxial silver halide may be developed, or both epitaxial silver halide and silver iodide may be developed. Selective development is possible. Therefore, the photographic emulsions used in this invention can be used to control the graininess and granularity of the photographic image, to control the release of iodide ions, or to select development conditions that control the maximum density of the resulting image. It also has the advantage of being able to The present invention will be explained in more detail below. In this specification, the term "epitaxy" is used in Japanese Patent Application Laid-Open No. 53-103725 and US Pat. No. 4,142.90.
The meanings of the terms described in No. 0 are the same. That is,
The crystallographic orientation of silver chloride, silver chlorobromide, silver chloroiodide, silver bromide, silver iodobromide, and silver chlorobromoiodide bonded to a silver iodide crystal substrate changes during their crystal growth. This means that it is controlled by crystals such as silver iodide, which are crystal substrates. In this case, the relationship between the silver chloride, silver chlorobromide, silver chloroiodide, silver bromide, silver iodobromide, and silver iodide parts of the hybrid crystal and the silver iodide part as the crystal matrix is , which is quite different from direct physical contact of separate crystals of silver iodide, silver bromide, silver iodobromide, etc. The epitaxial hybrid silver halide used in the present invention as described above can be formed by the method described below.
No. 5, No. 55-163532, U.S. Patent No. 4,142
, No. 900, etc. (A) Crystals of silver bromide or silver iodobromide are formed by simultaneously mixing a solution containing water-soluble bromide or a solution containing water-soluble bromide and water-soluble iodide with a silver salt solution on polyhedral crystals of silver iodide. (B) a method of epitaxially bonding a silver bromide crystal to a polyhedral crystal of silver iodide, and forming the silver bromide crystal by a conversion method in a solution containing water-soluble iodide; (C) ) Adding a solution containing water-soluble bromide, or a solution containing water-soluble bromide and water-soluble iodide to a solution containing polyhedral crystals of silver iodide, a water-soluble silver salt, and a protective colloid, which serve as a crystal substrate, by a single jet method. , a method of epitaxy bonding silver bromide or silver iodobromide crystals. The silver iodide as the substrate crystal in the present invention is polyhedral radiation-sensitive silver iodide, at least in part of which has a minimum average grain size of at least 0.degree. 1 .mu.m. This polyhedral crystal of silver iodide is produced by the method (A), (B) or [C] above.
It is formed by epitaxially bonding crystals of silver bromide or silver iodobromide. At least 25% of the polyhedral crystal faces of this silver iodide are substantially free of epitaxial silver halide, and the epitaxial silver halide is limited to 75 mol% or less of the total mixed silver halide. The photographic emulsion according to the present invention contains a mixed fine crystal of silver iodide and silver bromide or silver iodobromide. A portion of each hybrid crystal is a normal silver iodide crystal, and the silver iodide crystal is preferably a truncated double pyramid crystal type β-phase ratio silver crystal. Silver iodide crystals as crystal substrates used in the present invention are described in Japanese Patent Application Laid-Open No. 53-10
No. 3725 and U.S. Pat. No. 4,142,900, the silver iodide of the present invention also contains at least 0.2
Those having a minimum average particle size of μ are preferably used. Further, the second part of each hybrid crystal, that is, the part formed by epitaxy bonding to the polyhedral silver iodide crystal as a crystal substrate by the method [A], (B) or (C), is odorless. It is a crystal of silver oxide or silver iodobromide. The silver iodide content of the epitaxially bonded silver iodobromide crystal is suitably 12 mol % or less based on the epitaxial silver iodobromide crystal. The specific structure of the epitaxial hybrid silver halide crystal (hereinafter referred to as hybrid crystal) contained in the photographic emulsion of the present invention is considered to be as follows. That is, as detailed in U.S. Pat. No. 4,142.900, the hybrid crystal of the present invention has a truncated hexagonal double pyramidal β-
It consists of a phase iodide crystal and a polyhedral silver bromide or silver iodobromide crystal, and the silver bromide or silver iodobromide crystal forms an epitaxial junction with the silver iodide crystal as a crystal substrate. In the hybrid crystal used in the present invention, the silver iodide crystal portion acts as a first radiation receptor. Imagewise exposure of blue light to a photographic emulsion containing the hybrid crystals of this invention forms a developable latent image. When the hybrid crystal of silver iodide and silver bromide or silver iodobromide of the present invention is exposed to light, the entire hybrid crystal can be developed, but it is also possible to develop only the epitaxial silver halide portion. The hybrid crystal used in the present invention is free of epitaxial silver halide on at least 25% of the polyhedral crystal faces of silver iodide, and the epitaxial silver halide is typically formed on the truncated or side faces of the silver iodide crystal. limited to. Further, in the hybrid crystal used in the present invention, epitaxial silver halide is limited to 75 mol % or less of the total mixed silver halide. When the epitaxial silver halide content reaches 75 mol %, the epitaxial silver halide crystal structure on the surface of the adjacent silver iodide crystal plane is located at the point on the silver iodide crystal plane where epitaxial growth of epitaxial silver halide begins. This is because it erodes. The epitaxial silver halide in the hybrid crystal of the present invention is not the first radiation receptor of the hybrid crystal. For this reason,
The photographic speed of the photographic emulsion according to the invention is not controlled by radiation impinging on the epitaxial silver halide. The amount of epitaxial silver halide in the hybrid crystal according to the invention is desirably 1 to 50 mol% of the total hybrid tin halide, more preferably the minimum content is 5 mol%. This epitaxy tin halide has the effect of accelerating the initial development rate. The optimum amount of epitaxial silver halide used in the present invention depends on the intended use of the photographic emulsion according to the present invention. For example, if a high radiation exposure level and fast development rate are required, a higher proportion of epitaxy silver halide should be used than if the radiation exposure level is low and the development rate is slow. I can do it. In addition, epitaxial silver halide can be controlled by adjusting the size of the crystal used so that the silver iodide crystal as a crystal substrate is not developed and the epitaxial silver halide is developed. . The photographic speed in this case is determined by the silver iodide crystals as a larger crystal substrate. The hybrid crystals according to the invention are monodisperse or polydisperse. Here, "monodisperse" refers to [
having the same meaning as defined in Illingsworth J, at least 95% of the weight or number of the hybrid crystals being ±40% of the average grain size of the silver halide crystals. It means within. In this case, the average grain size is the average minimum grain size of the hybrid crystal. The relative advantages of "monodisperse" and "polydisperse" emulsions are well known in the art, such as that monodisperse emulsions exhibit higher contrast than polydisperse emulsions. The epitaxial silver halide crystals of the present invention, unless specifically modified during formation, render the hybrid crystals of the present invention reactive towards surface development. Therefore, when a decrease in sensitivity occurs due to light absorption by a colored dye-donating substance as in the case of the present invention, the epitaxial silver halide crystal acts extremely effectively in compensating for the decrease in sensitivity. The hybrid crystal according to the present invention can also be structurally formed so that the latent image generated when a single light beam is irradiated exists inside the crystal structure rather than on the surface thereof. In this case, an internal dopant can be introduced into the epitaxial silver halide crystal to facilitate the formation of internal latent images in the hybrid crystal. Such internal dopants include, for example, silver,
Includes sulfur, iridium, gold, platinum, osmium, rhodium, tellurium, selenium, etc. In producing such a hybrid crystal that primarily forms an internal latent image, for example, an epitaxial silver halide crystal can be placed in the presence of non-silver metal ions, preferably polyvalent metal ions. In particular, epitaxial silver halide crystals are preferably formed in the presence of water-soluble salts of the individual metals, more preferably in an acidic medium. In this case, preferably used polyvalent metal ions include divalent metal ions (lead ions, etc.), trivalent metal ions (antimony, bismuth, arsenic, gold, iridium, rhodium ions, etc.), or tetravalent metal ions. (iridium ion, etc.), but in the present invention, polyvalent metal ions such as iridium, bismuth, or lead are particularly preferred. The hybrid crystal used in the present invention has the above-mentioned (A), (B) or (C
), epitaxial silver bromide or epitaxial iodobromide crystals are formed. The preparation of silver iodide as a crystal substrate to be used is described in Japanese Patent Application Laid-Open No. 103-1983.
It can be carried out according to the method described in No. 725 and US Pat. No. 4,142.900, and a specific production example thereof is also shown in Example 1 below. The silver halide photographic emulsion according to the present invention can be adjusted by blending different emulsions to obtain desired photographic properties. This method also allows control over photographic speed and contrast. The silver halide emulsion according to the present invention contains a hybrid crystal of the present invention, when at least 50% by weight of all silver halide crystals is a hybrid crystal of the present invention, when the hybrid crystal is present blended with another silver halide crystal. Crystals are primarily involved in image formation. Also, by mixing 50% by weight or less, interimage effects and edge effects can be effectively controlled. For example, when blending silver chloride crystals and hybrid crystals, the ratio of the blend can be arbitrarily selected depending on the application, but in order to obtain a remarkable effect by dissolution physical development, it is necessary to blend silver chloride crystals with hybrid crystals. It is desirable that the amount is 1 to 50% by weight, more preferably 5 to 50% by weight of the total silver halide. The silver halide used in the present invention may be used in combination of two or more types having different sizes and/or halogen compositions, and the preferred size of silver halide grains is an average grain size of 0. 00
1 μm-1 (Drm, particularly preferably from 0.001 μm
It is 5 μm. Why does the photosensitive silver halide described above exhibit a unique effect when used in a heat-developable photosensitive material that releases a hydrophilic dye and forms a dye image by heating as in the case of the present invention? Although the reason for doing so is not clear,
It can be estimated as follows. That is, it is known that pure silver iodide exhibits a crystal phase transition phenomenon at 150°C (J, Photo. Sc1..18.53 (1970)), but the α-type iodide formed at that time It is also known that silver exhibits significantly higher silver ion conductivity than β-type silver iodide at around room temperature. Although the relationship between such a phase transition phenomenon and the image forming reaction rate during heating is not clear, in the case of the present invention, phase transition occurs during heating, and the silver iodide substrate after the phase transition is It can be assumed that the high silver ion conductivity shown contributes to the acceleration of the formation rate of the dye image. The conventional silver halide emulsion that can be blended with the mixed crystals in the present invention is usually chemically sensitized, although so-called primitive emulsions that are not chemically sensitized can also be used. For chemical sensitization, the GIafkides or Ze
likman et al. or H. Fr1eserli "Die Glundlagen der PhoLog"
raphischen Prozesse mit Silver-halog
In other words, a sulfur sensitization method using a sulfur-containing compound capable of reacting with silver ions or active gelatin, a noble metal sensitization method using a reducing substance. etc. can be used alone or in combination. As the sulfur sensitizer, thiosulfates, thioureas, thiazoles, rhodanines, and other compounds can be used. The silver halide used in the present invention is , methine dyes, etc. The dyes used include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes,
Included are hemicyanine dyes, styryl dyes and hemioxonol dyes. Particularly useful dyes are cyanine dyes,
It is a pigment belonging to merocyanine pigments and complex merocyanine pigments. Any of the nuclei commonly used for cyanine dyes can be used as the basic heterocyclic nucleus for these dyes. Namely, viroline nucleus, oxazinone nucleus, thiazoline nucleus, virol nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus, pyridine nucleus, etc.; a nucleus in which an alicyclic hydrocarbon ring is fused to these nuclei; and these A nucleus in which an aromatic hydrocarbon ring is fused to the nucleus of , quinoline nucleus, etc. can be applied. These nuclei may be substituted on carbon atoms. Merocyanine dyes or composite merocyanine dyes include a pyrazolin-5-one nucleus, a thiohydantoin nucleus, a 2-thioxazolidine-2,
A 5- to 6-membered heterocyclic nucleus such as a 4-dione nucleus, a thiazolidine-2,4-dione nucleus, a rhodanine nucleus, a thiobarbic acid nucleus, etc. can be applied. These sensitizing dyes may be used alone or in combination, and combinations of sensitizing dyes are often used particularly for the purpose of supersensitization. Along with the sensitizing dye, the emulsion may contain a dye that itself does not have a spectral sensitizing effect or a substance that does not substantially absorb visible light and exhibits supersensitization. For example, aminostyl compounds substituted with nitrogen-containing heterocyclic groups (e.g., U.S. Pat. No. 2,933.390, U.S. Pat. No. 3,635,7)
21), aromatic organic acid formaldehyde condensates (such as those described in US Pat. No. 3,743,510), cadmium salts, azaindene compounds, and the like. In order to incorporate these sensitizing dyes into the silver halide emulsion used in the present invention, they may be present during the formation of silver halide grains in the emulsion, they may be dispersed in the emulsion, or they may be added to water. , methanol, ethanol, acetone, methyl cellosolve, etc., alone or in a mixed solvent, and then added to the emulsion. Alternatively, after dissolving them in a substantially water-immiscible solvent such as phenoxyethanol, they may be dispersed in water or a hydrophilic colloid, and this dispersion may be added to the emulsion. Furthermore, these sensitizing dyes can be mixed with the lipophilic compound of the dye-providing substance and added at the same time. In addition, these sensitizing dyes may be dissolved separately or as a mixture, and when added to an emulsion, added at the same time as a mixture, or added separately. or may be added at the same time as other additives. It may be added to the emulsion at the time of chemical ripening or before or after chemical ripening. The temperature at which these sensitizing dyes are added to the emulsion is 30
The temperature range may be from °C to 80 °C. In the present invention, it is preferable to use an 1i1Mtl salt oxidizing agent in combination, since it is possible to obtain a photosensitive material that develops color at a higher density. The organic silver salt oxidizing agent used in the present invention is produced at a temperature of 80°C or higher, preferably 100°C in the presence of photosensitive silver halide.
When heated to the above temperature, it reacts with the image-forming substance or a reducing agent coexisting with the image-forming substance if necessary, to form a silver image. The silver halide that can be used in this case does not necessarily have to have the characteristic of containing pure silver iodide crystals when silver halide is used alone, and all compositions known in the art may be used. silver halide can be used. Examples of such organic silver salt oxidizing agents include silver salts of organic compounds having a carboxyl group, and typical examples include silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. There is. Examples of silver salts of aliphatic carboxylic acids include behenic acid, silver stearic acid, oleic acid, lauric acid, capric acid, myristic acid, and palmitic acid. tin salt, silver salt of maleic acid, silver salt of fumaric acid,
silver salt of tartaric acid, silver salt of furoic acid, silver salt of linoleic acid,
Examples include silver salts of oleic acid, silver salts of adipic acid, silver salts of sebacic acid, silver salts of succinic acid, silver salts of acetic acid, silver salts of butyric acid, silver salts of camphoric acid, etc. Also, silver salts substituted with halogen atoms or hydroxyl groups are also effective. Silver salts of aromatic carboxylic acids and other carboxyl group-containing compounds include silver salts of benzoic acid, silver salts of 3゜5-dihydroxybenzoic acid, silver salts of 0-methylbenzoic acid, and silver salts of m-methylbenzoic acid. , silver salt of p-methylbenzoic acid, 2□
Silver salts of substituted benzoic acids such as silver salts of 4-dichlorobenzoic acid, IN salts of acetamidobenzoic acid, silver salts of p-phenylbenzoic acid, silver salts of gallic acid, silver salts of tannic acid, silver salts of phthalic acid. , silver salt of terephthalic acid, silver salt of salicylic acid, silver salt of phenylacetic acid, silver salt of pyromellitic acid, 3-carboxymethyl-4-methyl-4- as described in U.S. Pat. No. 3,785,830. Examples include silver salts such as thiazoline-2-thione, and silver salts of aliphatic carboxylic acids having thioether groups as described in US Pat. No. 3,330.663. In addition, there are silver salts of compounds having a mercapto group or a thione group and derivatives thereof. For example, 3-mercapto-4-phenyl-1゜2.4-
) silver salt of lyazole, silver salt of 2-mercaptohenshiimidazole, silver salt of 2-mercapto-5-aminothiadiazole, silver salt of 2-mercaptobenzthiazole, 2-
Silver salts of thioglycolic acid described in JP-A-48-28221, such as silver salts of (s-ethylglycolamide)benzthiazole, S-alkyl (alkyl groups having 12 to 22 carbon atoms) thioglycolic acid, dithio Silver salts of dithiocarboxylic acids such as silver salts of acetic acid, silver salts of thioamides, silver salts of 5-carboxy-1-methyl-2-phenyl-4-thiopyridine, silver salts of mercaptotriazine, 2-mercaptobenzuoxazole silver salts of mercaptooxadiazole, silver salts described in U.S. Pat. No. 4,123,274, such as the 1,2.4-mercaptotriazole derivative 3-amino-5-henzylthio 1.2゜4
-Silver salts of triazoles, U.S. Pat. No. 3,301.678
3-(2-carboxyethyl)-4 described in No. 18IW
-A silver salt of a thione compound such as a silver salt of methyl-4-thiazoline-2-thione. In addition, there are silver salts of compounds having imino groups. For example, silver salts of benzotriazole and its derivatives described in Japanese Patent Publication Nos. 44-30270 and 45-18416, silver salts of alkyl-substituted hensitriazoles such as benzotriazole silver salts, methylhensitriazole silver salts, 5- silver salts of halogen-substituted henctriazoles, such as silver salts of chlorohencitriazole; silver salts of carboimidobenzotriazoles, such as silver salts of butylcarboimidobenzotriazole; 1 described in U.S. Pat. No. 4,220.709; .2.41 Tin salts of lyazole and 1-H-tetrazole, silver salts of carbazole, silver salts of saccharin, silver salts of imidazole and imidazole derivatives, etc. In addition, in the present invention, research disclosure 1
Organic metal salts such as silver salts and copper stearate described in No. 70 No. 17029 can also be used in the same manner as the various silver salts mentioned above. Two or more of the above organic silver salt oxidizing agents can be used in combination. In the present invention, the coating amount of photosensitive silver halide and organic silver salt is 50 mg to 10 mg/r in terms of silver.
d is appropriate. The following compounds and the like can be used as reducing agents in the photosensitive material of the present invention. Hydroquinone compounds (e.g. hydroquinone, 2.5-dichlorohydroquinone, 2-chlorohydroquinone), aminophenol compounds (e.g. 4-aminophenol, N-methylaminophenol, 3-methyl-4-aminophenol, 3゜5- dibromoaminophenol), catechol compounds (e.g. catechol, 4-
cyclohexylcatechol, 3-methoxycatechol,
4-(N-octadecylamino)catechol), phenylenediamine compounds (e.g. N,N-diethyl-p-phenylenediamine, 3-methyl-N,N-diethyl-p
-phenylenediamine, 3-methoxy-N-ethyl-N
-ethoxy-p-phenylenediamine, N, N, N'
, N''-tetramethyl-p-phenylenediamine). Examples of more preferred reducing agents include the following: 3-pyrazolidone compounds (e.g. l-phenyl-3-hyrazolidone, 1-phenyl-4,4-dimethyl -3-pyrazolidone, 4-hydroxymethyl-4-methyl-1-
Phenyl-3-pyrazolidone, l-m-tolyl-3-pyrazolidone, 1-p-tolyl-3-pyrazolidone, 1-
Phenyl-4-methyl-3-virapritone, 1-phenyl-5-methyl-3-pyrazolidone, 1-phenyl-4
゜4-bis-(hydroxymethyl)-3-pyrazolidone, 1,4-di-methyl-3-pyrazolidone, 4-methyl-3-pyrazolidone, 4,4-dimethyl-3-virapritone, 1-(3-chlorophenyl) )-4-methyl-3-
Virapritone, 1-(4-chlorophenyl)-4-methyl-3-pyrazolidone, 1-(4-)lyl)-4-methyl-3-pyrazolidone, 1-(2-)lyl)-4-methyl-3- Pyrazolidone, 1-(4-)lyl)-3-pyrazolidone, 1-(3-)lyl)-3-pyrazolidone, 1
-(3-tolyl-4,4-dimethyl-3-pyrazolidone, 1-(2-)lifluoroethyl)-4,4-dimethyl-3-pyrazolidone, 5-methyl-3-pyrazolidone). Combinations of various developers can also be used, such as those disclosed in US Pat. No. 3,039,869. In the present invention, the amount of reducing agent added is about 0.01 mol to about 20 mol, preferably 0.01 mol to about 20 mol, of reducing agent per 1 mol of silver.
1 mole - about 10 moles. In the present invention, a so-called auxiliary developer can be used as necessary together with the reducing dye-donating substance. The auxiliary developer in this case is oxidized by silver halide,
The oxidant has the ability to oxidize the reducing substrate in the dye-donating substance. Useful auxiliary developers include hydroquinone, t-dimethylhydroquinone, alkyl-substituted hydroquinones such as 2,5-dimethylhydroquinone, catechols, pyrogallols, halogen-substituted hydroquinones such as chlorohydroquinone and dichlorohydroquinone, and alkyl-substituted hydroquinones such as methoxyhydroquinone. There are substituted hydroquinones and polyhydroxybenzene derivatives such as methylhydroxynaphthalene. Furthermore, hydroxylamine L such as methyl gallate, ascorbic acid, ascorbic acid derivatives, N,N'-di(2-ethoxyethyl)hydroxylamine, L-phenyl-3-pyrazolidone, 4-methyl-4
Pyrazolidones such as -hydroxymethyl-1-phenyl-3-pyrazolidone, reductones, hydroxytetronic acids, etc. are useful. Auxiliary developers can be used in a range of concentrations. Useful concentration ranges are o, oo for silver. Particularly useful concentration ranges are 5 times molar to 20 times molar.
It is 0.001 times mole to 4 times mole. The photosensitive silver halide, organic silver salt oxidizing agent of the present invention is prepared in the binder described below, and the dye-providing substance is also dispersed in the binder described below. The binders used in the present invention can be used alone or in combination. This binder has
Hydrophilic materials can be used. Typical hydrophilic binders are transparent or translucent hydrophilic colloids, such as proteins such as gelatin, gelatin derivatives, and cellulose derivatives, and natural substances such as polysaccharides such as starch, gum arabic, pullulan, and dextrin. and synthetic polymeric materials such as water-soluble polyvinyl compounds such as polyvinyl alcohol, polyvinylpyrrolidone, and acrylamide polymers. Other synthetic polymeric compounds include dispersed vinyl compounds, which increase the dimensional stability of photographic materials, especially in the form of latexes. Various dye release aids can be used in the present invention. The dye release aid is a compound that exhibits basicity and can activate development, or a compound that has so-called nucleophilicity, and a base or a base precursor is used. The dye-releasing aid can be used in either a light-sensitive material or a dye-fixing material. It is especially advantageous to use a base precursor when it is included in a light-sensitive material. The base precursor here is one that releases a base component upon heating, and the base component released may be an inorganic base or an organic base. Preferred inorganic bases include alkali metal or alkaline earth metal hydroxides, secondary and tertiary phosphates, borates,
Carbonates, quinolinates, metaborates, ammonium hydroxides, quaternary alkyl ammonium hydroxides, and other metal hydroxides are included, and organic bases include aliphatic amines Alkylamines, hydroxylamines, aliphatic polyamines), aromatic amines N
-Alkyl-substituted aromatic amines, N-hydroxylalkyl-substituted aromatic amines and Hibis (p-(dialkylamino)phenylcomethane w4), heterocyclic amines, amidines, cyclic amidines, guanidines, cyclic guanidines etc., and U.S. Patent No. 2,410,64
No. 4 contains betaine tetramethylammonium iodide, diaminobutane dihydrochloride, and U.S. Patent No. 3.5.
No. 06.444 describes organic compounds containing amino acids such as urea and 6-aminocaproic acid, and these can be preferably used. In the present invention,
Those with a pKa of 8 or higher are particularly useful. Base precursors include salts of organic acids and bases that decarboxylate and decompose when heated, compounds that decompose through Rossen rearrangement, Beckmann rearrangement, etc. and release amines, and those that cause some kind of reaction when heated to release bases. used. Preferred base precursors include the aforementioned organic base precursors. For example, salts with thermally decomposable organic acids such as trichloroacetic acid, trichloroacetic acid, propiolic acid, cyanoacetic acid, sulfonylacetic acid, and acetoacetic acid, and salts with 2-carboxycarboxamide described in U.S. Pat. No. 4,088°496. Can be mentioned. Preferred specific examples of base precursors are shown below. Examples of compounds whose acid moieties are thought to decarboxylate and release bases include the following: Examples of trichloroacetic acid derivatives include guanidine trichloroacetic acid, piperidine trichloroacetic acid, morpholine trichloroacetic acid, p-)luidine trichloroacetic acid, and 2-picoline trichloroacetic acid. Others include British Patent No. 998,945, U.S. Patent No. 3,
Base precursors described in No. 220,846, JP-A-50-22625, etc. can be used. Other than trichloroacetic acid, U.S. Patent No. 4,0
Examples include 2-carboxycarboxamide derivatives described in US Pat. No. 88,496, α-sulfonylacetate derivatives described in U.S. Pat. . In addition to organic bases, salts containing alkali metals and alkaline earth metals as base components are also effective;
69597. Effective precursors other than those mentioned above include hydroxame carbamates described in Japanese Patent Application No. 58-43860 that utilize Rossen rearrangement, and aldoxime carbamates described in Japanese Patent Application No. 58-31614 that produce nitrile. Also, the amine imides described in Research Disclosure Ti, May 1977 issue No. 15776, JP-A-50-2
The aldoneamides described in Publication No. 2625 are:
It is preferably used because it decomposes at high temperatures to produce a base. These bases or base precursors can be used in a wide variety of ways. A useful range is 50% by weight or less, more preferably 0% by weight of the coated dry film of the photosensitive material.
．． It ranges from 0.01% to 40% by weight. It goes without saying that the above bases or base precursors can be used not only for promoting dye release but also for other purposes, such as adjusting the pHO value. Specific examples of preferred bases are shown below. Lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, potassium carbonate, sodium quinolate, potassium quinolate, dibasic sodium phosphate, dibasic
Potassium phosphate, tribasic sodium phosphate, tribasic potassium phosphate, sodium birophosphate, potassium pyrophosphate,
Sodium metaborate, potassium metaborate, borax,
Ammonium hydroxide, tetramethylammonium, tetrabutylammonium, ammonia, CH3Nf (2,
(CH3)2NH, C2H3NH2, (C2H5)2N
HSC4H9NH2, (C4H9)2NH, HOC2H
4NH2, (HOC2H4)2NH. (C2H5)2NCH2CH20H. H2NC2H4NH2, CH3NHC2H4NHCH3, (CH3)2NC2H4NH2, H2NC3H3NH2, H2NC4H6NH2SH2N
C3HI 0NH2, (CH3)2NC2H4N (CH3)2, (CH3)
2NC5H5N (CH3)2, Jade Various imaging materials can be used in various ways in the present invention. Many methods have been proposed for obtaining color images. A method of forming a color image by combining an oxidized developer with a coupler is described in U.S. Pat. No. 3,531. ．． No. 286 describes p-phenylenediamine frequent reducing agents and phenolic or active methylene couplers, U.S. Pat. September 1975, pages 31-32, proposes a sulfonamidophenol reducing agent, and US Pat. No. 4,021,240 proposes a combination of a sulfonamidophenol reducing agent and a 4-equivalent coupler. The couplers used in the above image forming method are those described in the above cited patents. Furthermore, color couplers used in conventionally widely known liquid development processes can also be used. These couplers are, for example, compounds that can develop color through oxidative coupling with aromatic-grade amine developers (e.g., phenylenediamine derivatives, aminophenol derivatives, etc.), and representative ones are collectively referred to as follows. It is something that For example, magenta couplers include 5-pyrazolone couplers, pyrazolobenlimigsol couplers, cyanoacetylcoumarone couplers, open-chain acylacetonitrile couplers, and yellow couplers include acylacetamide couplers (e.g., benzoylacetanilides, pivaloylacetanilides). cyan couplers include naphthol couplers and phenol couplers. These couplers are preferably non-diffusible ones having a hydrophobic group called a ballast in their molecules, or polymerized ones.The couplers may be either 4-equivalent or 2-equivalent to silver ions. It may also be a colored coupler that has a color correction effect or a coupler that releases a development inhibitor during development (so-called DIR coupler). Furthermore, a European patent describes a method of separating mobile dyes and forming images using a coupling reaction with a reducing agent oxidized by a redox reaction with silver halide or an organic silver salt at high temperatures. No. 67゜455, same No. 79,05
No. 6 and German Patent No. 3 217.853, the compounds described therein can also be used as image-forming substances in the present invention. In addition, a nitrogen-containing heterocyclic group is introduced into the dye to form a silver salt,
A method of releasing dyes by heat development was published in Research Disclosure magazine, May 1978 issue (RD-16966).
) described on pages 54 to 58. Further, regarding the method of forming a positive color image by photosensitive silver dye bleaching method, for example, Research Disclosure i
f; April 1976 issue (RD-14433) pages 30-3
2 pages, December 1976 issue (RI)-15227)
Useful dyes and bleaching methods are described on pages 14-15, U.S. Pat. No. 4,235,957, and elsewhere. Further, regarding methods of forming color images using leuco dyes, for example, U.S. Pat.
, No. 022,617. The compounds described in the above three methods can also be used as image forming substances in the present invention. Furthermore, in recent years, various new materials and methods for forming color images using heat development have been proposed, and these materials are particularly preferably used in the present invention. European Patent No. 66.282 and European Patent No. 76 describe methods using dye-donating substances that undergo redox reactions with silver halides or organic silver salts at high temperatures, resulting in the release of mobile dyes. ．．
No. 492, West German Patent No. 3,215,485, Patent Application No. 1973
No. 8-26008 and No. 5B-28928. The dye-providing substance used in this method and particularly useful in the present invention is represented by the following formula (I). D-Y(I) Here, D represents a dye moiety or its precursor moiety, and Y has the functionality of changing the diffusivity of the dye-donating substance (1) due to the redox reaction caused in the heat development process. Represents the substrate. "Diffusivity changes" means: ■ Compound (1) is originally non-diffusible and changes to diffusive, or a diffusible dye is released, or ) changes to non-diffusive. Further, depending on the nature of Y, this change may occur when Y is oxidized or reduced, and both can be used appropriately. As an example of the change in diffusivity due to oxidation of Y, first of all, p
- Sulfonamidonaphthol IJI (including p-sulfonamidophenols; specific examples are described in JP-A-48-33826, JP-A-53-50736, and European Patent No. 76.492), O-sulfonamidophenol IJI
4 (also includes 0-sulfonamide phenols, JP-A-1988
No. 1-113624, No. 56-12642, No. 56-
No. 16130, No. 56-16131, No. 57-650
No. 57-4043, U.S. Patent No. 4,053,31
No. 2, specific examples are described in European Patent No. 76.492)
, hydroxysulfonamide heterocycles (JP-A-51-1
No. 04343, specific examples are described in European Patent No. 76.492), 3-sulfonamindoles (Japanese Unexamined Patent Publication No.
-104343, 53-46730, 54-1
No. 30122, No. 57-85055, European Patent No. 76
．． Specific examples are described in No. 492). Among these, Ra-3O2-D (Ra is a reducing substrate, D
is a dye and releases a dye when oxidized by silver halide) is particularly preferred. Another example is JP-A No. 57-20735, in which Y releases a dye by intramolecular nucleophilic attack after being oxidized.
Examples include intramolecularly assisted substrates described in Japanese Patent Application No. 177148/1982. Another example is a substrate that releases a dye by an intramolecular ring-closing reaction under basic conditions, but does not substantially release the dye when Y is oxidized (Japanese Patent Laid-Open No. 51-63618 Specific examples are given in the issue). Furthermore, as a modification of this, a substrate in which the isoxacilone ring is re-wound by the nuclear reagent and releases the dye is also useful (
Specific examples are described in JP-A-49-111628 and JP-A-52-4819). Another example is a substrate in which the dye moiety is released due to dissociation of acidic protons under basic conditions, but when Y is oxidized, the dye does not substantially release (
Specific examples are described in JP-A-53-69033 and JP-A-54-130927). On the other hand, examples of the diffusivity changing due to reduction of Y include the nitro compound described in JP-A-53-110827, JP-A-53-110827, and U.S. Patent No. 4,356,249. , No. 4,358,525. These are reduced by the reducing agent (referred to as electron donor) that remains unconsumed during the heat development process.
As a result, the dye is released by molecular attack on the resulting nuclear group. As a modification of this, quinone-type substrates are also useful, in which the dye moiety is released by dissociation of the acidic protons of the reduced product (JP-A-54-130927, JP-A-56-16).
Specific examples are described in No. 4342). When using a substrate whose diffusivity changes due to the reduction described above, it is essential to use an appropriate reducing agent (electron donor) that mediates between the tin salt oxidizing agent and the dye-donating substance. Specific examples are described in the above-mentioned publicly known materials. Further, a substrate in which an electron donor coexists in the substrate Y (referred to as an LDA compound) is also useful. Furthermore, as another image-forming material, a material that undergoes an oxidation-reduction reaction with silver halide or an organic tin salt at high temperatures and as a result changes the mobility of a compound having a dye moiety can be used. -39400. Further, materials that release mobile dyes by reaction with silver ions in photosensitive materials are described in Japanese Patent Application No. 58-55692. Many of the above-mentioned materials are heat-developed to form an image-like distribution of mobile dyes corresponding to exposure in the light-sensitive material, and these image dyes are transferred to a dye-fixing material (so-called diffusion transfer) for visualization. Regarding the method of
It is written in No. 2, etc. In the present invention, the dye-donating substance is U.S. Pat.
They can be introduced into the layers of the photosensitive material by known methods such as the method described in No. 2,027. In that case, the following high boiling point organic solvents and low boiling point organic solvents can be used. For example, phthalic acid alkyl esters (dibutyl phthalate, dioctyl phthalate, etc.), phosphoric acid esters (diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, dioctyl butyl phosphate), citric acid esters (e.g. acetyl tributyl citrate), benzoic acid esters (octyl benzoate), alkylamides (e.g. diethyl laurylamide), fatty acid esters It (e.g. dibutoxyethyl succinate, dioctyl azelate), trimesic acid esters (
high-boiling organic solvents such as tributyl trimesate), or organic solvents with a boiling point of about 30°C to 160°C, such as lower alkyl acetates such as ethyl acetate, butyl acetate,
After dissolving in ethyl propionate, secondary butyl alcohol, methyl isobutyl ketone, β-ethoxyethyl acetate, methyl cellosolve acetate, cyclohexanone, etc., it is dispersed in a hydrophilic colloid. The above-mentioned high boiling point organic solvent and low boiling point organic solvent may be mixed and used. Also, Japanese Patent Publication No. 51-39853, Japanese Patent Publication No. 51-5994
The dispersion method using a polymer described in No. 3 can also be used. In addition, various surfactants can be used when dispersing the dye-donating substance in the hydrophilic colloid, and these surfactants include those listed as surfactants elsewhere in this specification. can use things. The amount of the high boiling point organic solvent used in the present invention is 10 g or less, preferably 5 g or less per 1 g of the dye-providing substance used.
g or less. A dye transfer aid can be used to transfer the dye from the photosensitive layer to the dye fixed layer. In a system in which the transfer aid is externally supplied, water or a basic aqueous solution containing caustic soda, caustic potash, or an inorganic alkali metal salt is used as the dye transfer aid. Also, methanol,
A low boiling point solvent such as N,N-dimethylformamide, acetone, diisobutyl ketone, or a mixed solution of these low boiling point solvents and water or a basic aqueous solution is used. The dye transfer aid may be used in such a way that the image-receiving layer is wetted with the transfer aid. If a transfer aid is incorporated into a photosensitive material or dye fixing material,
There is no need to supply transfer aids externally. The above transfer aid may be incorporated into the material in the form of crystal water or microcapsules, or may be incorporated as a precursor that releases the solvent at high temperatures. More preferably, a hydrophilic thermal solvent that is solid at room temperature and melts at high temperature is incorporated into the light-sensitive material or dye-fixing material. The hydrophilic heat solvent may be incorporated into either the photosensitive material or the dye fixing material, or may be incorporated into both. Further, the layer to be incorporated may be any of an emulsion layer, an intermediate layer, a storage layer, and a dye fixing layer, but it is preferably incorporated in the dye fixing layer and/or its adjacent layer. Examples of hydrophilic heat solvents include ureas, pyridines, amides, sulfonamides, imides, alcohols, oximes, and other heterocycles. Other compounds that can be used in the light-sensitive material in the present invention, such as sulfamide derivatives, cationic compounds having a pyridinium group, surfactants having polyethylene oxide groups, sensitizing dyes, antihalation and irradiation dyes, hardening film Regarding agents, mordants, etc., see European Patent No. 66.282, European Patent No. 76.492, West German Patent No. 3,315.485, Japanese Patent Application No. 58-26008,
Those described in No. 58-28928 can be used. Furthermore, the methods cited in the above patents can be used for methods such as exposure. (Effects of the Invention) In the present invention, by using epitaxy silver halide as a photosensitive silver halide in which the amount of internal latent image and surface latent image can be freely controlled, initial development of epitaxy silver halide can be achieved. Utilizing the speed acceleration effect, it is possible to realize a heat-developable light-sensitive material in which dye images can be formed rapidly. In addition, especially when a reducing dye-donating substance that directly reacts with silver ions is used in a light-sensitive material, the sensitivity decreases due to light absorption by the colored dye-donating substance.
It is particularly useful because it can eliminate disadvantages such as non-utilization of internal latent images due to the large molecular volume of the dye-donating substance, which makes it difficult to move. Furthermore, since the photographic material of the present invention contains both epitaxial silver halide and silver iodide, it is possible to control the graininess and granularity of photographic images and to control the release of iodide ions by selecting development conditions. The present invention has great significance because it can also control the maximum density of an image. EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. (Example) Example 1 Preparation example of silver halide emulsion 20 g of gelatin, 86 g of potassium iodide, and 20 mj2 of 25% aqueous ammonia were dissolved in 3 i of water, and this solution was
The mixture was stirred while being maintained at 0°C. Next, add 80 g of silver nitrate to 80 g of water.
0 mj+ was added to the above solution over 80 minutes. After adjusting the pH of the silver iodide emulsion thus produced, settling it, and removing excess salt, the pH was adjusted to 6.0, and the silver iodide became the substrate for hybrid silver halide crystals with a yield of 400 g. An emulsion was obtained. Next, silver chloride was epitaxially bonded to this emulsion by the following procedure. 10 g of gelatin and 400 g of the above silver iodide emulsion were dissolved in 21 g of water and stirred while maintaining the temperature at 70°C. To this solution, 5 g of silver nitrate was dissolved in 200 mj+ of water, and 2 g of sodium chloride was dissolved in 200 mj of water! was added over 5 minutes. Next, the pH of this emulsion was adjusted, sedimented, and after removing excess salt, the pH was adjusted to 6.0 to give a yield of 450 g, and 40 g of gelatin and 500 ml of water were added.
1 kg of the silver halide emulsion of the present invention was obtained. Comparative Example 1 Next, a method for preparing a silver iodobromide emulsion for comparison will be described. This comparative emulsion exhibits rapid development and a high maximum density among silver halide emulsions previously studied. 40 g of gelatin and 26 g of potassium bromide were dissolved in 3β of water, and the solution was stirred while being maintained at 50°C. Next, add 34g of silver nitrate to 200mj of water! was added to the above solution over a period of 10 minutes. Then add 3.3g of potassium iodide to 100mj of water! was added over 2 minutes. The pH of the silver iodobromide emulsion thus produced was adjusted, the emulsion was allowed to settle, excess salt was removed, and the pH was adjusted to 6.0, yielding 400 g of a silver iodobromide emulsion.

[Preparation of a gelatin dispersion of a dye-providing substance, a photosensitive coating, and an image-receiving material having an image-receiving layer] ■ Preparation of a dispersion of a dye-providing substance having the following structural formula: 5 g of a dye-providing substance, as a surfactant, Weighed 0.5 g of sodium succinate 2-ethyl-hexyl ester sulfonate and 5 g of licresyl phosphate, added 30 mβ of ethyl acetate, and heated the mixture to approximately 60°C.
The mixture was heated to dissolve and form a homogeneous solution. This solution and 100 g of a lO% solution of lime-treated gelatin were stirred and mixed, and then dispersed using a homogenizer at 10.00 rpm for 10 minutes. This dispersion is called a dispersion of a dye-providing substance. (2) Next, a method for producing a photosensitive coating will be described. (a) Emulsion of the present invention (comparative emulsion was used in the case of comparative coatings) 16 g (b) Dispersion of dye-providing substance 33 g (C) 10% by weight ethanol solution of guanidine trichloroacetic acid 16 ml (d ) 5% by weight aqueous solution of a compound with the following structure 5ml (6) 4ml 10% by weight aqueous solution of dimethylsulfamide (f) Water 15mj! After mixing and dissolving the above (a) to (f), they were coated on a polyethylene terephthalate film to a wet film thickness of 30 μm. 3% by weight of gelatin on it
An aqueous solution was applied to give a wet film thickness of 30 μm to form a protective layer. After drying this sample, use a tungsten bulb to
Imagewise exposure was made for 10 seconds at Lux. Thereafter, it was heated uniformly on a heat block heated to 130° C. for 20.30 seconds and 40 seconds, respectively. 0 Next, a method for producing the dye fixing material will be described. Dissolve 10 g of poly(methyl acrylate-N,N,N-trimethyl-N-vinylbenzylammonium chloride) (ratio of methyl acrylate and vinylbenzylammonium chloride is 1:1) in 200 ml of water,
It was uniformly mixed with 100 g of 10% lime-treated gelatin. This mixed solution was uniformly applied to a wet film thickness of 90 μm on a paper support laminated with polyethylene in which titanium dioxide was dispersed. After drying, this sample was used as a dye fixing material having a mordant layer. After immersing this dye-fixing material in water, the above-mentioned heated photosensitive material was stacked so that the film surfaces were in contact with each other. Thereafter, the dye-fixing material was peeled off from the light-sensitive material by heating for 6 seconds on a heat block at 80.degree. C., and a negative magenta color image was obtained on the dye-fixing material. The maximum density (DmaX) of this negative image with respect to green light was measured using a Macbeth reflection density needle (RD-519). The results are shown in Table 1. Table 1 However, the numbers in the table represent the maximum concentration/minimum concentration. From this result, it was demonstrated that the silver halide emulsion of the present invention progresses faster when heated than the comparative emulsion. Example 2 Preparation method of benzotriazole silver emulsion Prepared by the method shown below. 28 g of gelatin and 13.2 g of benzotriazole were mixed with 3 g of water.
The solution was stirred while maintaining the temperature at 40°C. Next, a solution prepared by dissolving 17 g of silver nitrate in 100 mj+ of water was added to the above solution over a period of 2 minutes. The pH of the benzotriazole silver emulsion thus prepared was adjusted, sedimented, excess salt was removed, and the pH was adjusted to 6.0, yielding 400 g.
A benzotriazole silver emulsion was obtained. Next, a method for producing a photosensitive coating will be described. (a) Emulsion of the present invention (comparative emulsion was used in the case of comparative coatings) 16 g (b) Benzotriazole silver emulsion 10 g (C) Dispersion of dye-providing substance 33 g (d) Guanidine trichloroacetic acid dispersion 10% by weight ethanol solution 15mjl(e) 5% by weight aqueous solution of a compound with the following structure 5m! (f) 4 ml of 10% by weight aqueous solution of dimethylsulfamide (g) 5 me water After mixing and dissolving the above (a) to (g), apply on polyethylene terephthalate film to a wet film thickness of 30 μm. did. 3% by weight of gelatin on it
An aqueous solution was applied to give a wet film thickness of 30 μm to form a protective layer. After drying this sample, use a tungsten bulb to
Imagewise exposure was made for 10 seconds at Lux. Thereafter, it was heated uniformly for 20.30 and 40 seconds, respectively, on a heat block heated to 130°C. Next, in the same manner as in Example 1, the heated photosensitive material and the dye fixing material were superimposed, and the density of the negative magenta color image obtained on the 0 dye fixing material, which was peeled off after heating, with respect to green light was measured. It was measured using a reflection densitometer (RD-519). The results are shown in Table 2. Table 2 These results demonstrate that even when a benzotriazole silver emulsion is used, the photosensitive material of the present invention progresses rapidly in development by heating.

Claims (1)

[Claims] ■A polyhedral crystal of silver iodide, and at least one crystal selected from chloride, silver chlorobromide, chloroiodide, silver iodobromide, or silver chloroiodobromide in the polyhedral crystal of silver iodide. A hybrid silver halide crystal consisting of crystals formed by epitaxial bonding, wherein at least 25% of the crystal faces of silver iodide are substantially free of epitaxial silver halide and the epitaxial silver halide is a hybrid halide crystal. When the photosensitive silver halide, which accounts for 75 mol% or less of the total silveride, the binder, and the photosensitive silver halide are reduced, a hydrophilic dye is released or formed in an image-like manner in response or inversely to the reduction. A heat-developable photosensitive material containing a dye-donating substance.