JPH0362259B2 - - Google Patents

Description

[Detailed description of the invention]

<<Industrial Application Field>> The present invention relates to a novel photosensitive material with excellent developability and storage stability. More specifically, the present invention relates to a photosensitive material containing a dye-providing substance that reacts with photosensitive silver halide to release a hydrophilic dye when heated in a substantially water-free state, and in particular, This invention relates to a novel silver halide photosensitive material with excellent performance and storage stability before use. 《Prior art》 The photographic method using silver halide is different from other photographic methods,
For example, compared to electrophotography and diazo photography, it has superior photographic characteristics such as sensitivity and gradation adjustment.
It has traditionally been the most widely used. In recent years, a technology has been developed that allows images to be formed easily and quickly on photosensitive materials using silver halide by changing from the conventional wet processing using a developing solution to a dry processing using heating, etc. It's here. Heat-developable photosensitive materials are well known in the art, and for information on heat-developable photosensitive materials and their processes, see
“For example, the basics of photographic engineering (published by Corona Publishing, 1979)
pages 553-555, video information published in April 1978, page 40,
Nebletts Handbook of Photography and
Reprography 7th Ed. (Van Nostrand Reinhold
Company) pages 32-33,
U.S. Patent Nos. 3152904, 3301678, 3392020
No. 3457075, British Patent No. 1131108, No.
No. 1167777 and Research Disclosure Magazine, June 1978, pages 9 to 15 (RD-17029). Many methods have already been proposed for obtaining color images using a dry method. Regarding a method of forming a color image by combining an oxidized form of a developer with a coupler, U.S. Pat. p-
Aminophenol reducing agent received Belgian patent no.
Issue 802519 and Research Disclosure Magazine
In the September 1975 issue, pages 31-32, sulfonamide phenolic reducing agents are described, and in U.S. Pat. No. 4,021,240,
A combination of a sulfonamidophenol reducing agent and a 4-equivalent coupler has been proposed. However, in such a method, a reduced silver image and a color image are simultaneously generated in the exposed area after thermal development, so that the color image becomes cloudy. To solve this problem, there are methods to remove the silver image by liquid processing or to transfer only the dye to another layer, such as a sheet with an image-receiving layer. It has the disadvantage that it is not easy to transfer. Another method is to introduce a nitrogen-containing heterocyclic group into a dye, form a silver salt, and release the dye by heat development.
Research Disclosure Magazine May 1978 Issue 54
Pages 58 to 58 (RD-16966). This method is not a common method because it is difficult to suppress the release of dye in areas not exposed to light, making it impossible to obtain clear images. Further, regarding the method of forming positive color images by thermal silver dye bleaching method, for example, Research Disclosure Magazine, April 1976 issue, pages 30-32 (RD-
14433), December 1976 issue of the same magazine, pages 14-15 (RD-
15227) and US Pat. No. 4,235,957, useful dyes and bleaching methods are described. However, this method requires extra steps and materials, such as stacking and heating activator sheets to accelerate the bleaching of the dye, and the resulting color image is gradually reduced by coexisting free silver, etc. Since it is bleached, it has the disadvantage of not being able to withstand long-term storage. Further, regarding methods of forming color images using leuco dyes, for example, U.S. Pat.
Described in No. 4022617. However, this method has the disadvantage that it is difficult to stably incorporate the leuco dye into the photographic material, and the material gradually becomes colored during storage. The present inventors have already provided a new photosensitive material that can overcome the drawbacks of these conventional methods.
It is reducible to at least the photosensitive silver halide, the binder and the photosensitive silver halide, and can be imagewise produced by heating in a substantially water-free state after or simultaneously with the exposure. A photosensitive material capable of releasing a mobile hydrophilic dye,
This mobile hydrophilic dye could be transferred to the dye fixed layer primarily in the presence of a solvent. Although the above-mentioned photosensitive materials were excellent in that high-quality images could be obtained by an extremely simple method, there was still room for improvement in terms of storage stability and developability before use. However, it is generally not easy to improve the developing performance and storage performance of photosensitive materials while maintaining their sensitivity. <<Problem to be Solved by the Invention>> Therefore, the first object of the present invention is to provide a heat development method capable of obtaining a high-density dye image by short-term heat development after exposure or at the same time as exposure. Our purpose is to provide photosensitive materials. A second object of the present invention is to provide a photosensitive material for heat development that can reduce fogging of a high-density dye image caused by heat development after exposure or simultaneously with exposure. . A third object of the present invention is to provide a photosensitive material for thermal development that can release an auxiliary developer at a controlled rate during thermal development. Furthermore, a fourth object of the present invention is to provide a photosensitive material for heat development that has excellent storage stability before heat treatment. <<Means for Solving the Problems>> The objects of the present invention are to provide at least a photosensitive silver halide, a binder, and a binder on a support that is reducible to the photosensitive silver halide, and to A heat-developable photosensitive material characterized by having a dye-donating substance that releases a hydrophilic dye by reacting with photosensitive silver halide and an auxiliary developer precursor represented by the following general formula, and uses thereof. This was achieved using a conventional image forming method. [General formula] In the formula, A represents a group that can be cleaved by alkaline hydrolysis, and R represents an aryl group. R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom, an alkyl group or an aryl group, and may be the same or different. In the photosensitive material according to the present invention, the exposed photosensitive silver halide is converted into a photosensitive silver halide by using the exposed photosensitive silver halide as a catalyst by heating in a substantially water-free state after or simultaneously with the imagewise exposure. Because an oxidation-reduction reaction occurs with the reducing dye-donating substance, in addition to the silver image in the exposed area, there is also a silver image separated from the dye-donating substance that has been oxidized by silver halide. A mobile hydrophilic dye image is also obtained at the same time. However, in many cases, unreacted dye-providing substances coexist when heat development is performed, making it difficult to distinguish from the detached mobile hydrophilic dye image, which is not preferable. In this case, since the dye in the obtained dye image is a hydrophilic mobile dye, it can be moved to the dye fixed layer in an atmosphere to which the hydrophilic dye has affinity. Therefore, a dye image with excellent image quality and storage stability can be obtained. In this case, an atmosphere having affinity with the hydrophilic dye can be easily achieved not only by supplying a solvent, but also by providing a hydrophilic thermal solvent, especially by supplying a solvent from the outside. It is also possible to create an atmosphere that has affinity with hydrophilic dyes without having to do so. This principle remains essentially the same whether a negative-tone emulsion or an auto-positive emulsion is used as the emulsion for the light-sensitive material. A dye image with good color reproducibility can be obtained in the same manner as when using a negative emulsion, except that only the dye image among the silver image and mobile dye image is transferred to the dye fixing layer. In the present invention, the redox reaction between the photosensitive silver halide and the dye-donating substance and the subsequent dye-releasing reaction can be caused by heating in a substantially solvent-free state. Heating means heating to a temperature of 80°C to 250°C, and a state substantially free of water means that the reaction system is in equilibrium with moisture in the air and there is no water present to cause or accelerate the reaction. This means that there is no special supply of water. This condition is explained by “The theory of the photographic
process”4th Ed. (Edited by THJames,
Macmillan) on page 374. In the present invention, the dye to be released can be selected by selecting the dye-donating substance, so that various colors can be reproduced. Therefore, it is possible to create multiple colors by selecting a combination of them, so the dye image in the present invention includes not only a single color but also a multicolor image, and a monochrome image also includes a monochrome image obtained by mixing two or more colors. be done. Conventional dye release reactions are thought to be caused by attack by so-called nucleophiles, and given that they are usually carried out in an aqueous solution with a high pH of 10 or higher.
It is extremely unusual for the photosensitive material used in the present invention to exhibit a high reaction rate only by heating in a state substantially free of water. Furthermore, based on conventional knowledge obtained from wet development at around room temperature, it is possible that the dye-donating substance used in the present invention can undergo a redox reaction with silver halide without the aid of a so-called auxiliary developer. It is also extremely unusual (patent application 157798, 1982). The above reaction proceeds particularly well when an organic silver salt oxidizing agent is present, and high image density can be obtained. Therefore, it is a particularly preferred embodiment to coexist an organic silver salt oxidizing agent. The reducing dye-donating substance that releases the hydrophilic diffusible dye used in the present invention is represented by the following general formula Ra-SO ₂ -D (). Here, Ra represents a reducing substrate that can be oxidized by silver halide, and D represents an image-forming dye portion having a hydrophilic group. The reducing substrate (Ra) in the dye-donating substance Ra-SO ₂ -D has a redox potential of 1.2 with respect to a saturated calomel electrode in polarographic half-wave potential measurement using acetonitrile as a solvent and sodium perchlorate as a supporting electrolyte. V or less is preferable.
The preferred reducing substrate (Ra) has the following general formula ()
~(). Here, R ¹ _a , R ² _a , R ³ _a , and R ⁴ _a are each a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an aralkyl group, an acyl group, an acylamino group, and an alkylsulfonyl group. Amino group, arylsulfonylamino group, aryloxyalkyl group, alkoxyalkyl group, N-substituted carbamoyl group, N-substituted sulfamoyl group,
Represents a group selected from a halogen atom, an alkylthio group, and an arylthio group, and the alkyl group and aryl group moiety in these groups can further be an alkoxy group, a halogen atom, a hydroxyl group, a cyano group, an acyl group, an acylamino group, and a substituted carbamoyl group. , a substituted sulfamoyl group, an alkylsulfonylamino group, an arylsulfonylamino group, a substituted ureido group or a carbalkoxy group. Furthermore, the hydroxyl group and amino group in Ra may be protected with a protecting group that can be regenerated by the action of a nucleophilic reagent. In a more preferred embodiment of the present invention, the reducing substrate Ra is represented by the following formula (). Here, G represents a hydroxyl group or a group that provides a hydroxyl group through hydrolysis. R ¹⁰ _a represents an alkyl group or an aromatic group. n represents an integer from 1 to 3. X ¹⁰ represents an electron-donating substituent when n=1; when n=2 or 3, it may be the same or different substituent, and when one of them is an electron-donating group, it represents an electron-donating substituent; 3 is an electron donating group or a halogen atom, and X ¹⁰ may form a condensed ring by itself or may form a ring with OR ¹⁰ _a .
The total number of carbon atoms in both R ¹⁰ _a and X ¹⁰ is 8 or more. Among those included in formula () of the present invention, in a more preferred embodiment, the reducing substrate Ra is represented by the following formulas (a) and (b). Here, Ga represents a hydroxyl group or a group that provides a hydroxyl group through hydrolysis. R ¹¹ _a and R ¹² _a may be the same or different, each an alkyl group, or R ¹¹ _a and R ¹² _a may be linked to form a ring. R ¹³ _a represents a hydrogen atom or an alkyl group, and R ¹⁰ _a represents an alkyl group or an aromatic group. X ¹¹ and X ¹² may be the same or different and each represents a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, an acylamino group or an alkylthio group, and
R ¹⁰ _a and X ¹² or R ¹⁰ _a and R ¹³ _a may be linked to form a ring. Here, Ga is a hydroxyl group or a group that provides a hydroxyl group by hydrolysis, R ¹⁰ _a is an alkyl or aromatic group, X ² is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, an acylamino group, or an alkylthio group, ² and R ¹⁰ _a may be connected to form a ring. Specific examples included in (), (a), and (b) are described in US Pat. In another further preferred embodiment of the present invention,
The reducing substrate (Ra) is represented by the following formula (XI). (However, the symbols Ga, X ¹⁰ , R ¹⁰ _a and n have the same meanings as Ga, X ¹⁰ , R ¹⁰ _a n in formula ().) More preferred embodiments of those included in (XI) of the present invention In , the reducing substrate (Ra) is represented by the following formulas (XIa) to (XIc). However, Ga is a hydroxyl group or a group that gives a hydroxyl group by hydrolysis; R ²¹ _a and R ²² _a may be the same or different and each represents an alkyl group or an aromatic group; R ²¹ _a and R ²² _a may combine to form a ring; R ²⁵ _a represents a hydrogen atom, an alkyl group, or an aromatic group; R ²⁴ _a represents an alkyl group or an aromatic group; R ²⁵ _a represents an alkyl group , represents an alkoxy group, an alkylthio group, an arylthio group, a halogen atom, or an acylamino group; p is 0, 1 or 2; R ²⁴ _a and R ²⁵ _a may be bonded to form a condensed ring; ; R ²¹ _a and R ²⁴ _a may be combined to form a condensed ring; R ²¹ _a and R ²⁵ _a may be combined to form a condensed ring, and R ²¹ _a , ^R22a _, ^R23a _, ^R24a _{_}
and (R ²⁵ _a ) _p has a total number of carbons greater than 7. However, Ga is a hydroxyl group or a group that gives a hydroxyl group by hydrolysis; R ³¹ _a represents an alkyl group or an aromatic group; R ³² _a represents an alkyl group or an aromatic group; R ³³ _a is an alkyl group, an alkoxy group, represents an alkylthio group, an arylthio group, a halogen atom or an acylamino group; q is 0, 1 or 2; R ³² _a and R ³³ _a may combine to form a condensed ring; R ³¹ _a and R ³² _a may be combined to form a fused ring; R ³¹ _a and R ³³ _a may be combined to form a fused ring; and R ³¹ _a , R ³² _a , (R ³³ _a ) The total number of carbon atoms in _q is greater than 7. In the formula, Ga represents a hydroxyl group or a group that provides a hydroxyl group through hydrolysis; R ⁴¹ _a represents an alkyl group or an aromatic group; R ⁴² _a represents an alkyl group, an alkoxy group, an alkylthio group, an arylthio group, or a halogen atom , or represents an acylamino group; r is 0, 1 or 2;

[Formula] The group represents a condensation of 2 to 4 saturated hydrocarbon rings, and the carbon atom in the condensed ring participates in bonding to the phenol (or its precursor) core.

[Formula] is a tertiary carbon atom constituting one element of a condensed ring, and some of the carbon atoms in the hydrocarbon ring (excluding the tertiary carbon atoms mentioned above) are substituted with oxygen atoms. or the hydrocarbons may have a substituent,
Furthermore, an aromatic ring may be fused; R ⁴¹ _a or R ⁴² _a and the above

[Formula] The group may form a fused ring. However, R ⁴¹ _a , (R ⁴² _a ) _r and

[Formula] The total number of carbon atoms in the group is 7 or more. Specific examples included in (XI), (XIa) to (XIb) above are Japanese Patent Applications No. 56-16131, No. 57-650, No. 57-4043.
It is described in. Formula () and the essential part of formula () are para-(sulfonyl)aminophenol moieties.
Specific examples include US3928312, US4076529,
US Published Patent Application B 351673,
Examples of reducing substrates disclosed in US4135929 and US4258120 are also effective as the reducing substrate (Ra) of the present invention. In another further preferred embodiment of the present invention,
The reducing substrate (Ra) is represented by the following formula (XII). Here, Ballast represents a diffusion-resistant group. Ga represents a hydroxyl group or a hydroxyl group precursor. G ¹ _a represents an aromatic ring and represents a group forming a naphthalene ring together with a benzene ring. n and m represent different integers of 1 or 2. Specific examples covered by XII above are described in US-4053312. The reducing substrates of formulas (), (), () and () are characterized by containing a heterocycle, and specific examples include US4198235, JP-A-46730,
Examples include those described in US4273855.
A specific example of a reducing substrate represented by the formula () is
It is described in US4149892. The following properties are required for the reducing substrate Ra. 1. To be rapidly oxidized by silver halide and to efficiently release a diffusible dye for image formation through the action of a dye release aid. 2. The dye-donating substance is diffusible in a hydrophilic or hydrophobic binder, and only the released dye needs to be diffusible. Therefore, the reducing substrate R must have large hydrophobicity. . 3. Excellent stability against heat and dye release aids, and should not release image-forming dyes until oxidized. 4. Easy to synthesize. Next, a preferred specific example of Ra that satisfies these conditions will be shown. In the examples, NH- represents a linkage with the dye moiety. Dyes that can be used as image-forming dyes include azo dyes, azomethine dyes, anthraquinone dyes, naphthoquinone dyes, styryl dyes, nitro dyes, quinoline dyes, carbonyl dyes, and phthalocyanine dyes, and representative examples are shown for each dye. In addition,
These dyes can also be used in the form of a temporarily shortened wavelength that can be multicolored during development. In the above formula, R ⁵¹ _a to R ⁵⁶ _a each represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkoxy group, an aryloxy group, an aryl group, an acylamino group, an acyl group, a cyano group, a hydroxyl group, or an alkylsulfonylamino group. group, arylsulfonylamino group, alkylsulfonyl group, hydroxyalkyl group, cyanoalkyl group, alkoxycarbonylalkyl group, alkoxyalkyl group, aryloxyalkyl group, nitro group, halogen, sulfamoyl group, N-substituted sulfamoyl group, carbamoyl group, Represents a substituent selected from N-substituted carbamoyl group, acyloxyalkyl group, amino group, substituted amino group, alkylthio group, and arylthio group, and the alkyl group and aryl group moiety in these substituents are further halogen atom,
hydroxyl group, cyano group, acyl group, acylamino group,
It may be substituted with an alkoxy group, a carbamoyl group, a substituted carbamoyl group, a sulfamoyl group, a substituted sulfamoyl group, a carboxyl group, an alkylsulfonylamino group, an arylsulfonylamino group, or a ureido group. Hydrophilic groups include hydroxyl group, carboxyl group, sulfo group, phosphoric acid group, imide group, hydroxamic acid group, quaternary ammonium group, carbamoyl group, substituted carbamoyl group, sulfamoyl group, substituted sulfamoyl group, sulfamoylamino group, substituted Examples include a sulfamoylamino group, a ureido group, a substituted ureido group, an alkoxy group, a hydroxyalkoxy group, and an alkoxyalkoxy group. In the present invention, those whose hydrophilicity is significantly increased by proton dissociation under basic conditions are particularly preferred, including phenolic hydroxyl groups, carboxyl groups, sulfo groups, phosphoric acid groups, imide groups, hydroxamic acid groups, ( (substituted) sulfamoyl group, (substituted) sulfamoylamino group, etc. The characteristics required for image-forming dyes are 1) having a hue suitable for color reproduction, 2) having a large molecular extinction coefficient, and 3) controlling light, heat, and addition of dye release aids and other substances contained in the system. 4) ease of synthesis; and 4) ease of synthesis.
Specific examples of preferred image-forming dyes satisfying these conditions are shown below. Here, H ₂ N-SO ₂ represents a bonding site with a reducing substrate. Next, specific examples of preferred dye-providing substances will be shown. In addition to the above-mentioned specific examples, the dye-donating substances of the present invention include US4055428, JP-A-56-12642,
56-16130, 56-16131, 57-650, 57-
4043, US3928312, US4076529, US Published
Patent Application B351673, US4135929,
US4198235, JP-A-53-46730, US4273855,
Compounds described in US4149892, US4142891, US4258120, etc. are also effective. In addition, US4013633, US4156609,
US4148641, US4165987, US4148643,
US4183755, US4246414, US4268625,
US 4245028, JP 56-71072, JP 56-25737, JP
55-138744, 55-134849, 52-106727, 51
Dye-donating substances that emit yellow dyes, such as those described in US Pat. Also
US3954476, US4932380, US3931144,
US3932381, US4268624, US4255509, JP-A-56
-73057, 56-71060, 55-134850, 55-
40402, 55-36804, 53-23628, 52-
Dye-donating substances that release magenta dyes, such as those listed in No. 106727, No. 55-33142, and No. 55-53329, are also effective in the present invention. Also US3929760,
US4013635, US3942987, US4273708,
US4148642, US4183754, US4147544,
US4165238, US4246414, US4268625, JP-A-56
-71061, 53-47823, 52-8827, 53-
Dye-donating substances that release cyan dyes, such as those listed in No. 143323, are also effective in the present invention. Two or more types of dye-donating substances may be used in combination. In this case, two or more types may be used in combination to express the same pigment, and cases in which two or more types are used in combination to express black are also included. The total amount of dye-donating substances is 10 mg/ ^m2 to 15
Suitably, it is used in a range of 20 mg/m ² to 10 g/m ² , preferably in a range of 20 mg/m 2 to 10 g/m ² . Next, the method for synthesizing the dye-donating substance will be described. Generally, the dye-donating substance of the present invention is a reducing substrate.
It is obtained by condensing the amino group of Ra with the chlorosulfonyl group of the image-forming dye. Depending on the type of substrate, the amino group of the reducing substrate Ra can be introduced by reduction of nitro, nitroso, or azo groups or ring opening of benzoxazole, and can be used as a free base or as a salt of an inorganic acid. . On the other hand, the chlorosulfonyl group in the image-forming dye moiety can be derived from the sulfonic acid or sulfonate of the dye by a conventional method, ie, by the action of a chlorinating agent such as phosphorus oxychloride, phosphorus pentachloride, or thionyl chloride. The condensation reaction between the reducing substrate Ra and the image-forming dye D is generally carried out in an aprotic polar solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, acetonitrile, etc. using pyridine, picoline, lutidine, triethylamine, It can be carried out in the presence of an organic base such as diisopropylethylamine at a temperature of 0 to 50°C, and the desired dye-donating substance can usually be obtained in a very good yield. An example of its synthesis is shown below. Synthesis Example 1: Synthesis of 6-hydroxy-2-methylbenzoxazole 306 g of 2,4-dihydroxyacetophenone,
164 g of hydroxylamine hydrochloride, 328 g of sodium acetate, 1000 ml of ethanol, and 500 ml of water were mixed and heated under reflux for 4 hours. The reaction solution was poured into 10 g of water, and the precipitated crystals were collected to obtain 314 g of 2,4-dihydroxyacetophenone oxime. Dissolve 30g of this oxime in 400ml of acetic acid and heat to 120°C.
Hydrogen chloride gas was blown into the mixture for 2 hours while heating and stirring. After cooling, the precipitated crystals were collected and washed with water to obtain 17 g of 6-hydroxy-2-methylbenzoxazole. Synthesis Example 2: Synthesis of 6-hexadecyloxy-2-methylbenzoxazole 18.0 g of 6-hydroxy-2-methylbenzoxazole synthesized in Synthesis Example 1, 36.9 g of 1-bromohexadecane, 24.0 g of potassium carbonate, N,N -120 ml of dimethylformamide was stirred at 90°C for 4.5 hours. The solid was separated from the reaction solution, and the solution was poured into 500 ml of methanol. Take the precipitated crystals and
45.0 g of -hexadecyloxy-2-methylbenzoxazole was obtained. Synthesis Example 3: Synthesis of 2-acetylamino-5-hexadecyloxyphenol 6-hexadecyloxy-2- obtained in Synthesis Example 2
Methylbenzoxazole 111g, ethanol
Mix 1300ml, 33% hydrochloric acid 110ml, and 550ml water, 55~
The mixture was stirred at 60°C for 4 hours. After cooling, the precipitated crystals were collected to obtain 113 g of 2-acetylamino-5-hexadecyloxyphenol. Synthesis Example 4: Synthesis of 2-acetylamino-4-t-butyl-5-hexadecyloxyphenol 30.0 g of 2-acetylamino-5-hexadecyloxyphenol obtained in Synthesis Example 3, Amberlyst 15 (USA, Rohm)・And Haas Co., Ltd. registered trademark)
20.0 g and 300 ml of toluene were mixed, and while stirring and heating at 80 to 90°C, isobutene was blown into the mixture for 5 hours. After removing the solid, the liquid was concentrated and 350 ml of n-hexane was added to the residue to precipitate crystals.
23.5 g of 2-acetylamino-4-t-butyl-5-hexadecyloxyphenol was obtained. Synthesis Example 5: Synthesis of 2-amino-4-t-butyl-5-hexadecyloxyphenol 2-acetylamino-4-t- obtained in Synthesis Example 4
Butyl-5-hexadecyloxyphenol 23.0
g, 120 ml of ethanol, and 96 ml of 35% hydrochloric acid,
The mixture was stirred and refluxed for 5 hours. After cooling the reaction solution, the precipitated crystals were collected to obtain 2-amino-4-t-butyl-5-hexadecyloxyphenol hydrochloride.
23.2g was obtained. Synthesis Example 6: 4-t-butyl-5-hexadecyloxy-2-[2-(2-methoxyethoxy)-5
Synthesis of -nitrobenzenesulfonylamino]phenol 2-amino-4-t-butyl- obtained in Synthesis Example 5
5-hexadecyloxyphenol hydrochloride 4.4g
and 3.1 g of 2-(2-methoxyethoxy)-5-nitrobenzenesulfonyl chloride were dissolved in 12 ml of N,N-dimethylacetamide, and 2.5 g of pyridine
ml and then stirred at 25°C for 1 hour. When the reaction solution was poured into dilute hydrochloric acid, an oily substance precipitated. When 30 ml of methanol was added to this oil, it crystallized and was collected. Yield 4.5. Synthesis Example 7: 2-[5-amino-2-(2-methoxyethoxy)benzenesulfonylamino]-4-
Synthesis of t-butyl-5-hexadecyloxyphenol 10g of the compound obtained in Synthesis Example 6 above was added to 60% ethanol.
Approximately 0.5 g of 10% palladium-carbon catalyst dissolved in ml
After adding hydrogen, pressurize hydrogen to 55Kg/cm ² and
Stirred at ℃ for 6 hours. Next, the catalyst was removed while hot, and when it was allowed to cool, crystals precipitated and were collected. Yield 7.5g. Synthesis Example 8: Synthesis of 3-cyano-4-[4-(2-methoxyethoxy)-5-sulfophenylazo]-1-phenyl-5-pyrazolone In a solution of 8.0 g of sodium hydroxide and 200 ml of water, 5-
Add 49.4 g of amino-2-(2-methoxyethoxy)benzenesulfonic acid, and add sodium nitrite.
A 13.8g aqueous solution (50ml) was added. Concentrated hydrochloric acid 60% separately
ml and 400 ml of water was prepared, and the above solution was added dropwise to this at 5°C or below. Thereafter, the reaction was completed by stirring at 5° C. or lower for 30 minutes. Separately, prepare a solution of 16.0 g of sodium hydroxide, 200 ml of water, 33.0 g of sodium acetate, and 200 ml of methanol, add 37.0 g of 3-cyano-1-phenyl-5-pyrazolone, and pour the diazo solution prepared above at 10°C or below. dripped. After the completion of the dropwise addition, the mixture was stirred for 30 minutes at 10° C. or lower, and then for 1 hour at room temperature. The precipitated crystals were collected, washed with 200 ml of acetone, and air-dried. Yield 52.0g mp263-265℃ Synthesis Example 9: Synthesis of 3-cyano-4-[4-(2-methoxyethoxy)-5-chlorosulfonylphenylazo]-1-phenyl-5-pyrazolone In the above Synthesis Example 8 The obtained 3-cyano-4-[(4-methoxyethoxy-5-sulfophenylazo]-1
-Phenyl-5-pyrazolone 51.0g, acetone
N,
50 ml of N-dimethylacetamide was added dropwise at below 50°C. After the addition, the mixture was stirred for about 1 hour and gradually poured into ice water. After separating the precipitated crystals, they were washed with 100 ml of acetonitrile and air-dried. Yield 46.7g mp181-183℃ Synthesis Example 10: Synthesis of dye-donating substance (1) 2-[5-amino-2-(2-methoxyethoxy)benzenesulfonylamino-4 obtained in Synthesis Example 7
3-cyano-4-[4-
(2-methoxyethoxy)-5-chlorosulfonylphenylazo]-1-phenyl-5-pyrazolone
4.6 g was added, followed by 5 ml of pyridine. After stirring at room temperature for 1 hour, the reaction solution was poured into dilute hydrochloric acid, and the precipitated crystals were collected. 7.5g recrystallized from N,N-dimethylacetamide-methanol
I got it. mp189-191℃ Synthesis Example 11: Synthesis of dye-donating substance (2) 2-[5-Amino-2-(2-methoxyethoxy)benzenesulfonylamino-4 obtained in Synthesis Example 7
Dissolve 6.3 g of -t-butyl-5-hexadecyloxyphenol in 30 ml of N,N-dimethylacetamide. 5.0 g of chlorosulfonylphenyl-5-pyrazolone was added, followed by 5 ml of pyridine. After stirring at room temperature for 1 hour, the reaction solution was poured into dilute hydrochloric acid, and the precipitated crystals were collected. Recrystallize with acetonitrile
8.4g was obtained. mp144-149℃ Synthesis Example 12: Synthesis of dye-donating substance (10) 4.4 g of 2-amino-4-t-butyl-5-hexadecyloxyphenol hydrochloride and 4-[3-
Chlorosulfonyl-4-(2-methoxyethoxy)
[phenylazo]-2-(N,N-diethylsulfamoyl)-5-methylsulfonylamino-1-naphthol (6.5 g) was dissolved in N,N-dimethylacetamide.
The solution was dissolved in 20 ml and 4.2 ml of pyridine was added. 1 hour 25
After stirring at °C, the reaction solution was poured into dilute hydrochloric acid. The precipitated solid was collected and purified by silica gel column chromatography (eluted with a mixed solvent of chloroform-ethyl acetate (2:1)). Yield: 5.2g. Synthesis Example 13: Synthesis of dye-donating substance (17) Dissolve 11.6 g of 2-amino-4-t-butyl-5-hexadecyloxyphenol hydrochloride in 100 ml of N,N-dimethylacetamide, and add 12 ml of pyridine.
added. This was added to 5-(3-chlorosulfonylbenzenesulfonylamino)-2-(N-t-butylsulfamoyl)-4-(2-methylsulfonyl-
4-nitrophenylazo)-1-naphthol 20g
added. After stirring for 1 hour, the mixture was poured into 500 ml of ice water, and the precipitate was recrystallized from isopropyl alcohol-acetonitrile (1:1) to obtain 6.8 g. Synthesis Example 14: Synthesis of dye-donating substance (19) 2-[5-amino-2-(2-methoxyethoxy)benzenesulfonylamino]-4-t-butyl-5-hexadecyloxyphenol 31.5 g,
39.1 g of 5-(3-chlorosulfonylbenzenesulfonylamino)-4-(2-methylsulfonyl-4-nitrophenylazo)-1-naphthol with N,
It was dissolved in 100 ml of N-dimethylacetamide, and 21 ml of pyridine was added. After stirring for 80 minutes, methanol 250
ml and 100 ml of water were added. The precipitated resinous material solidified after a while and was removed. This was recrystallized from a toluene-methanol-water (16:4:3) mixed system to obtain 41.5 g. Synthesis Example 15 Synthesis of Compound 40 a Synthesis of 2,5-dihydroxy-4-t-butylacetophenone 83 g of t-butylhydroquinone was dissolved in 400 ml of acetic acid, and boron trifluoride (BF ₃ ) was introduced for about 3 hours. After the reaction was completed, the mixture was poured into ice water in Step 1 to collect the precipitated viscous solid. This solid was dissolved in 600 ml of 2N-NaOH and the insoluble portion was removed. The solution was made acidic with dilute hydrochloric acid, and the precipitated crystals were collected, washed with water, and then recrystallized from aqueous methanol. Yield 68g (65%) b Synthesis of 2,5-dihydroxy-4-t-butylacetophenone, oxime 21g of the ketone obtained in a) above was mixed with 70% ethanol
ml, heated and dissolved with 24 g of sodium acetate,
While stirring, add 12 g of hydroxylamine hydrochloride to 70 g of water.
ml of the solution was added and refluxed for about 1 hour. After the reaction was completed, the mixture was poured into 500 ml of ice water, and the precipitated crystals were collected and recrystallized from benzene-hexane. Yield: 17 g (76%) c Synthesis of 6-t-butyl-5-hydroxy-2-methylbenzoxazole 14 g of the oxime obtained in b) above was dissolved in 100 ml of acetic acid, and dry hydrochloric acid gas was introduced while heating.
Refluxed for 1.5 hours. After the reaction was completed, the mixture was poured into 500 ml of ice water, and the precipitated crystals were collected and washed with water. Yield 9g (70%) d 6-t-butyl-5-hexadecyloxy-
Synthesis of 2-methylbenzoxazole 6.9 g of the benzoxazole obtained in c) above was dissolved in 50 ml of dimethylformamide, and 8 g of anhydrous potassium carbonate and 11 g of hexadecyl bromide were dissolved in the solution.
Stirred at ~90°C for 6 hours. After the reaction was completed, inorganic substances were removed and 150 ml of methanol was added to the solution, which was then cooled on ice to precipitate crystals. By taking this, the title compound was obtained. Yield 8.8g (62%) e Synthesis of hydrochloride of 2-amino-5-t-butyl-4-hexadecyloxyphenol Benzoxazole compound 7.3 obtained in d) above
g was refluxed for 3 hours with 30 ml of ethanol and 20 ml of concentrated hydrochloric acid. After the reaction was completed, the mixture was allowed to cool, and the precipitated crystals were collected, washed with water, and then washed with acetone. Yield: 6.9 g (92%) f Synthesis of Compound Example 40 6 g of the hydrochloride obtained in e) above and 8.8 g of the sulfonyl chloride of the dye having the structural formula below were dissolved in 50 ml of dimethylacetamide, and 4 ml of pyridine was added thereto for 1 hour at room temperature. Stirred. After the reaction was completed, the precipitated crystals were poured into dilute hydrochloric acid and washed with water. After drying, the residue was purified by silica gel chromatography to obtain 2.2 g of the title compound, which was essentially one component. Dye sulfonyl chloride: Synthesis Example 16: Synthesis of dye-donating substance (42) In the above Synthesis Example 15d), 6-t-butyl-
6-t-octyl-5-hydroxy- instead of 5-hydroxy-2-methylbenzoxazole
O-hexadecylation was performed using 2-methylbenzoxazole. A dye-donating substance (42) was then obtained by the same treatment as in Synthesis Example 15e) and f). The dye-donating substance of the present invention is disclosed in U.S. Pat.
It can be introduced into the layer of the photosensitive material by a known method such as the method described in No. 2322027. 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 (e.g. dibutoxyethyl succinate, dioctyl azelate), trimesic acid esters (e.g. tributyl trimesate), etc. Solvents, 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, ethyl propionate, secondary butyl alcohol, methyl isobutyl ketone, β-
After dissolving in 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 used in combination. Further, the dispersion method using a polymer described in Japanese Patent Publication No. 51-39853 and Japanese Patent Application Laid-Open No. 51-59943 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. You can use it. 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. In the present invention, an auxiliary developer can be used as necessary. The auxiliary developer used in the present invention is oxidized by a silver halide and/or organic silver salt oxidizing agent, and the oxidized product thereof has the ability to oxidize the reducing substrate Ra in the dye-donating substance. . Commonly useful auxiliary developers include:
Hydroquinone, t-butylhydroquinone,
Alkyl-substituted hydroquinones such as 2,5-dimethylhydroquinone, catechols, pyrogallols, halogen-substituted hydroquinones such as chlorohydroquinone and dichlorohydroquinone, alkoxy-substituted hydroquinones such as methoxyhydroquinone, and polyhydroxybenzene derivatives such as methylhydroxynaphthalene. be. Furthermore, hydroxylamines such as methyl gallate, ascorbic acid, ascorbic acid derivatives, N,N'-di-(2-ethoxyethyl)hydroxylamine, 1-
Phenyl-3-pyrazolidone, 4-methyl-4-
Examples include pyrazolidones such as hydroxymethyl-1-phenyl-3-pyrazolidone, reductones, and hydroxytetronic acids. Since the auxiliary developing agent precursor used in the present invention substantially exhibits the function of the auxiliary developing agent described above, in the light-sensitive material of the present invention containing the auxiliary developing agent precursor, the auxiliary developing agent described above is used in combination. However, it is not necessary to specifically include it in the photosensitive material, and as a result, the storage performance before use can be improved while maintaining the performance of the photosensitive material. In other words, the auxiliary developer precursor used in the present invention does not have a developing effect during storage of the photosensitive material before use, but can be developed by the action of an appropriate activator (e.g., base, nucleophile, etc.) or heating. This is the first compound capable of releasing an auxiliary developer. In particular, the auxiliary developer precursor used in the present invention does not function as an auxiliary developer before heating because the reactive functional group of the auxiliary developer is blocked with a blocking group. Due to the cleavage of the blocking group, the co-developing agent can be released at a speed that is not too rapid. The auxiliary developer precursor used in the present invention can be represented by the following general formula []. General formula [] In the formula, A represents a group that can be cleaved by alkaline hydrolysis, and R represents an aryl group. ^R1 , ^R2 , ^R3
and R ⁴ represent a hydrogen atom, an alkyl group, or an aryl group, and these may be the same or different. In the general formula [], the hydrolyzable group represented by A is:

【formula】 【formula】

etc. However, R ⁵ represents an aliphatic group having 1 to 22 carbon atoms, an aromatic group having 6 to 10 carbon atoms, or a heterocyclic group, and R ⁶ and R ⁷ represent a hydrogen atom or a hydrogen atom, and R 7 represents a hydrogen atom or a carbon atom 1 to 22.
represents an aliphatic group, an aromatic group having 6 to 10 carbon atoms, or a heterocyclic group, and R ⁵ and R ⁶ may be the same or different. The aliphatic groups represented by R ⁵ , R ⁶ and R ⁷ may be substituted or unsubstituted, chain-like or cyclic. Preferred substituents for aliphatic groups are alkoxy groups,
Aryloxy group, acylamino group, carbamoyl group, halogen atom, sulfonamide group, sulfamoyl group, carboxy group, alkanoyloxy group, benzoyloxy group, cyano group, hydroxyl group, ureido group, carbonyl group, aryl group, alkylsulfonyl group, alkoxy carbonyl group, alkylureido group, imidazolyl group, furyl group, nitro group, phthalimide group, thiazolyl group, alkanesulfonamide group, alkanesulfamoyl group,
Examples include an arylcarbonyl group, an imide group, and an alkoxycarbonylamino group. When R ⁵ , R ⁶ and R ⁷ each represent an aromatic group (particularly a phenyl group), the aromatic group may be substituted. Aromatic groups such as phenyl groups contain halogen atoms,
Nitro group, hydroxyl group, cyano group, carboxy group, alkyl group having 32 or less carbon atoms, alkenyl group, alkoxy group, alkoxycarbonyl group, alkanoyloxy group, alkoxycarbonylamino group, aliphatic amide group, alkylsulfamoyl group, alkyl It may be substituted with a sulfonamide group, an alkylureido group, an alkylsulfonyl group, an alkyl-substituted succinimide group, etc. In this case, the alkyl group may have an aromatic group such as phenylene interposed in the chain. The phenyl group may also be substituted with an aryloxy group, an aryloxycarbonyl group, an arylcarbamoyl group, an arylamido group, an arylsulfamoyl group, an arylsulfonamide group, an arylureido group, etc., and the aryl group of these substituents The moiety may be further substituted with one or more alkyl groups having a total of 1 to 22 carbon atoms. When R ⁵ , R ⁶ and R ⁷ represent a heterocyclic group, each of the heterocyclic groups is bonded to the linking group to which the auxiliary developer is bonded via one of the carbon atoms forming the ring.
Such heterocycles include thiophene, furan,
Pyran, pyrrole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine,
Examples include imidazole, thiazole, oxazole, triazine, thiasiazine, oxazine and the like. These may further have a substituent on the ring. Examples of the aryl group represented by R in the general formula [] include phenyl group, naphthyl group, tolyl group,
Examples include xylyl group. These groups may be substituted. For example, halogen atoms (chlorine atoms, bromine atoms, etc.), amino groups, alkoxy groups, aryloxy groups, hydroxyl groups, aryl groups, carbonamide groups, sulfonamide groups, alkanoyloxy groups, benzoyloxy groups, ureido groups,
It may be an aryl group substituted with a carbamate group, carbamoyloxy group, carbonate group, carboxy group, alkyl group (methyl group, ethyl group, propyl group, etc.). The alkyl group represented by R ¹ , R ² , R ³ and R ⁴ in the general formula [] is an alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group, etc.). The alkyl group may be substituted with a hydroxyl group, an amino group, etc.
Further, as the aryl group, phenyl group, naphthyl group, xylyl group, tolyl group, etc. can be used. These aryl groups may be substituted with a halogen atom (chlorine atom, bromine atom, etc.), an alkyl group (methyl group, ethyl group, propyl group, etc.), a hydroxyl group, or an alkoxy group (methoxy group, ethoxy group, etc.). R ¹ , R ² , R ³ and R ⁴ of the present invention are hydrogen atoms,
Preferred are alkyl groups having 1 to 10 carbon atoms, substituted alkyl groups having 1 to 10 carbon atoms, and aryl groups, and more preferred are hydrogen atoms, methyl groups, and hydroxymethyl groups. Specific examples of the auxiliary developer precursor used in the present invention are shown below. The auxiliary developer precursors of the present invention can generally be synthesized according to the reaction formula shown below. 1st stage H-Z+CH ₂ O→HOCH ₂ -Z 2nd stage A-L+HOCH ₂ -Z-LH -----→ A -OCH ₂ -Z In the formula, A and Z have the same meanings as the groups already defined. , and L represents a halogen atom or a hydroxyl group. In the second stage reaction, when L represents a hydroxyl group, carbodiimide or the like is used as a dehydration condensation agent, and when L represents a halogen atom,
A base may or may not be used as a deoxidizing agent. Next, a typical synthesis example of the precursor compound of the present invention will be shown. Synthesis example (1) Synthesis of exemplified compound (1) Step 4,4-dimethyl-1-phenyl-3
- 152 g of pyrazolidone was dissolved in 600 ml of acetic acid.
Aqueous solution 97 containing 37% formaldehyde in this solution
g was added dropwise at room temperature while stirring. After stirring for 2 hours, the solvent was distilled off under reduced pressure. Toluene 100 to the residue
ml was added, and water was azeotropically distilled off along with toluene under reduced pressure. 900 ml of hexane and 700 ml of ethyl acetate were added to the residue, and after heating and dissolving, it was allowed to cool to room temperature, the precipitated crystals were collected by filtration, and 1120 g of 4,4-dimethyl-2-hydroxymethyl-1-phenyl-3-pyrazolidone was added. Obtained. Step: 66 g of the obtained 4,4-dimethyl-2-hydroxymethyl-1-phenyl-3-pyrazolidone and 39 g of 4-chlorobenzoic acid were dissolved in 200 ml of N,N-dimethylformamide. 48 g of N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide hydrochloride was gradually added to this solution while stirring at room temperature. After reacting at room temperature for 4 hours, the reaction mixture was poured into water and extracted with 1 portion of ethyl acetate. The organic phase was washed with water, washed with anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was recrystallized from hexane and ethyl acetate to obtain 55 g of the desired product (1). Melting point is 88~
It was 89℃. Synthesis example (2) Synthesis of exemplified compound (2) 4,4-dimethyl-2 obtained in the step of synthesis example (1)
6.6 g of -hydroxymethyl-1-phenyl-3-pyrazolidone and 7.2 g of 4-chloro-3-methanesulfonamidobenzoic acid were dissolved in 20 ml of N,N-dimethylformamide. 2.6 g of N,N'-diisopropylcarbodiimide was added dropwise to this solution.
After reacting for 1 hour at room temperature, the precipitated solid (N,
N'-diisopropylurea) was filtered off, and the filtrate was poured into water. Precipitation was carried out using 200 ml of ethyl acetate, and the organic phase was separated and washed with water. After ethyl acetate was distilled off under reduced pressure, the residue was recrystallized from a mixed solvent of ethyl acetate and hexane to obtain 6.7 g of the target compound (2). The melting point was 138-140°C. Synthesis Example (3) Synthesis of Exemplary Compound (3) Step of Synthesis Example (1). 4,4'-dimethyl- obtained in
22 g of 2-hydroxymethyl-1-phenyl-3-pyrazolidone and 22 g of 4-methanesulfonamidobenzoic acid were mixed with 20 ml of dimethyl sulfoxide and N,N.
- 40 ml of dimethylformamide. 4-dimethylaminopyridine 0.3
g, and 13 g of N,N'-diisopropylcarbodiimide was added dropwise at room temperature. After stirring for 4 hours, 500 ml of ethyl acetate was added and washed with water. After filtering off the crystals deposited in the oil phase, the filtrate was concentrated under reduced pressure. The residue was recrystallized from ethyl acetate to obtain 29 g of the desired compound. The melting point was 153-154°C. Synthesis Example (4) Synthesis of Exemplary Compound (4) Step of Synthesis Example (1). 4,4'-dimethyl- obtained in
2-hydroxymethyl-3-pitizolidone 13.2g
and 9.2 g of 2-chlorophenyl isocyanate were dissolved in 40 ml of dimethyl sulfoxide. After reacting at room temperature for 3 hours, 100 ml of ethyl acetate was added.
Washed with water. The oil phase was separated and concentrated under reduced pressure.
The residue was recrystallized from a mixed solvent of ethyl acetate and hexane to obtain 8 g of the desired product (4). The melting point was 119-120°C. Synthesis Example (5) Synthesis of Exemplary Compound (7) Step of Synthesis Example (1). 4,4'-dimethyl- obtained in
3 g of 2-hydroxymethyl-3-pyrazolidone was suspended in 10 ml of ethyl acetate. Phenoxycarbonyl chloride was added dropwise at 10°C. Furthermore, pyridine
1.1 ml was added dropwise at 10°C and stirred at this temperature for 3 hours. After transferring to a separating funnel, the mixture was washed with water. After the oil phase was separated and treated with anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. The residue was chromatographed on a column packed with 250 g of silica gel using an eluent containing a 2:1 mixture of hexane and ethyl acetate. The fraction containing the product was concentrated to obtain 3.5 g of the desired compound, with a melting point of 98-101°C. The auxiliary developer precursor used in the present invention can be used within a certain concentration range. A useful concentration range is 0.0005 times molar to 20 times molar, and a particularly useful concentration range is 0.001 times molar to 4 times molar relative to silver. In order to introduce the auxiliary developer precursor into the hydrophilic colloid layer, a high boiling point organic solvent such as phthalic acid alkyl esters (dibutyl phthalate, dioctyl phthalate, etc.), phosphoric acid esters (diphenyl phosphate, triphenyl phosphate, etc.) is used. tricresyl phosphate, dioctyl butyl phosphate), citric acid esters (e.g. acetyl tributyl citrate), benzoic acid esters (e.g. octyl benzoate), alkylamides (e.g. diethyl laurylamide), fatty acid esters (e.g. di- butoxyethyl succinate, dioctyl azelate), trimesic acid esters (e.g. tributyl trimesate), etc., using the method described in US Pat. ethyl,
After dissolving in a lower alkyl acetate such as butyl acetate, 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 used in combination. Also, Special Publication No. 51-39853,
The dispersion method using a polymer described in JP-A-51-59943 can also be used. In addition, it can be directly dispersed in an emulsion, or it can be dissolved in water or alcohol and then dispersed in gelatin or an emulsion. The auxiliary developer precursor of the present invention can be used in combination of two or more, and can be added to each emulsion layer (blue-sensitive layer, green-sensitive layer, red-sensitive layer), or added to all emulsion layers. It can also be added to layers adjacent to the emulsion (antihalation layer, undercoat layer, intermediate layer, protective layer, etc.). The auxiliary developer may be added at any time during the manufacturing process, but it is generally preferable to add the auxiliary developer immediately before coating. Although the reaction mechanism in which the auxiliary developing agent precursor represented by the general formula [] used in the present invention releases the auxiliary developing agent is not necessarily clear, for example, the reaction in which the auxiliary developing agent is released by a base is as follows. It can be thought of as being expressed by the reaction equation. When the compound of the general formula [] is expressed as A-OCH ₂ -B below, the first stage is A-OCH ₂ -B-OH -----→ k ₁ A ^- +HOH ₂ C-B, and the second stage is: HOH ₂ C−Bk ₂ --→ ← -- k ₃ CH ₂ O +HB In the above reaction formula, k ₁ , k ₂ and k ₃ represent reaction rate constants of each reaction. In the second stage equilibrium reaction, it is generally known that the rate of methylol formation (k ₃ ) is greater than the rate of methylol decomposition (k ₂ ) (e.g.
Bull.Soc.Chim.France., 138 (1955) provides a detailed report on the production and decomposition reactions of methylolbenzamide). Furthermore, in the second stage equilibrium reaction, the methylol decomposition reaction is a first-order reaction, whereas the methylol formation reaction is a second-order reaction. In the first reaction, the production rate of the product does not depend on the concentration of the raw material, but in the second reaction, the production rate of the product depends on the concentration of the raw material.
That is, in a secondary reaction, the reaction rate at a certain time is higher at a high concentration than at a low concentration. Therefore, when constant k ₂ and k ₃ are given in the second stage equilibrium reaction, the concentration ratio of the methylol compound to B ^- will change as the concentration conditions change. Such theories are well known in reaction kinetics. The precursor compound of the present invention is usually dispersed in gelatin or the like dissolved in high-boiling oil in the film. Therefore, when raw film is stored, the precursor compound is present in a high concentration in the oiled plate, and even if the precursor compound decomposes slightly over natural aging, the secondary
It is thought that the concentration of the methylol compound is kept high in the step-by-step equilibrium reaction, and the amount of B ^- , which is a useful group for photography, released is extremely small. The experimental fact that the precursor compound of the present invention has excellent stability during storage of raw film (film before exposure) and does not exhibit adverse effects such as desensitization and fogging is believed to be based on the reasons explained above. On the other hand, during heating, a basic component generated by thermal decomposition is generated, and as a result, the precursor compound is hydrolyzed (first stage reaction), and then a decomposition reaction of the methylol compound occurs, and a sufficient amount of photographic property is obtained. It will be understood that a useful group is released. The experimental fact that when the precursor compound of the present invention is incorporated into a film exhibits sufficient photographic properties when heated, and the raw film has good stability during storage is based on the reasons stated above. Believable. The rate at which the auxiliary developer is released is determined by the general formula []
Naturally, it changes depending on the nature of the atomic group represented by A. The auxiliary developer precursors used in the present invention are therefore a group of compounds that allow the release rate of the auxiliary developer upon heating to be adjusted to the required rate. Silver halides used in the present invention include silver chloride,
Silver chlorobromide, silver chloroiodide, silver bromide, silver iodobromide, silver chloroiodobromide, silver iodide, etc. In the present invention, when silver halide is used alone without an organic silver salt oxidizing agent, it is preferable to use silver halide containing silver iodide crystals in some of its grains. Such silver halide exhibits a pattern of pure silver iodide as its X-ray diffraction pattern. Silver halide containing two or more types of halogen atoms is used in photographic light-sensitive materials, and in ordinary halide emulsions, silver halide grains form perfect crystals. For example, when measuring X-ray diffraction of a silver iodobromide emulsion, no pattern of silver iodide crystals or silver bromide crystals appears, but an X-ray diffraction pattern appears at positions corresponding to the mixing ratio. In the present invention, particularly preferred silver halides include silver iodide crystals in their grains, and therefore silver chloroiodide, silver iodobromide, and silver chloroiodobromide exhibit an X-ray pattern of silver iodide crystals. be. Such silver halide, for example silver iodobromide, can be obtained by first forming silver bromide grains by adding a silver nitrate solution to a potassium bromide solution, and then adding potassium iodide. It will be done. Two or more types of silver halides having different sizes and/or halogen compositions may be used in combination. The average grain size of the silver halide used in the present invention is from 0.001 μm to 10 μm, preferably from 0.001 μm to 5 μm. The silver halide used in the present invention may be used as it is, but it may also be compounded with chemical sensitizers such as compounds such as sulfur, selenium, tellurium, etc., compounds such as gold, platinum, palladium, rhodium and iridium, and halogenated silver halide. Chemical sensitization may also be achieved through the use of reducing agents such as tin or combinations thereof. For more information, see “The
Theory of the Photographic Process” 4th edition,
TH James, Chapter 5, pages 149-169. In a particularly preferred embodiment of the present invention, an organic silver salt oxidizing agent is used in combination, but the silver halide used in this case is characterized by containing pure silver iodide crystals when silver halide is used alone. All silver halides known in the art can be used. When the organic silver salt oxidizing agent used in the present invention is heated to a temperature of 80°C or higher, preferably 100°C or higher in the presence of photosensitive silver halide, the above-mentioned image-forming substance or, if necessary, the image-forming substance A silver image is formed by reacting with a reducing agent coexisting with the silver. By coexisting with an organic silver salt oxidizing agent, it is possible to obtain a photosensitive material that develops color with higher density. 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 aliphatic carboxylic acids include silver behenic acid, silver stearic acid, silver oleic acid, silver lauric acid, silver capric acid, silver myristic acid, and silver palmitic acid. , 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, silver salt of oleic acid,
Examples include 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, and silver salts of camphoric acid. 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, 3,
Silver salt of 5-dihydroxybenzoic acid, silver salt of o-methylbenzoic acid, silver salt of m-methylbenzoic acid, p-
Silver salts of substituted benzoic acids such as silver salts of methylbenzoic acid, silver salts of 2,4-dichlorobenzoic acid, silver salts of acetamidobenzoic acid, silver salts of p-phenylbenzoic acid,
Silver salt of gallic acid, silver salt of tannic acid, silver salt of phthalic acid, silver salt of terephthalic acid, silver salt of salicylic acid,
Silver salts of phenylacetic acid, silver salts of pyromellitic acid, silver salts of 3-carboxymethyl-4-methyl-4-thiazoline-2-thione described in US Pat. No. 3,785,830, and silver salts of 3-carboxymethyl-4-methyl-4-thiazoline-2-thione described in US Pat. There are silver salts of aliphatic carboxylic acids having a thioether group as described. 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,
Silver salt of 2,4-triazole, Silver salt of 2-mercaptobenzimidazole, 2-mercapto-5-
Silver salts of aminothiadiazole, silver salts of 2-mercaptobenzthiazole, silver salts of 2-(s-ethylglycolamido)benzthiazole, s-alkyl (alkyl group having 12 to 22 carbon atoms) thioglycol acetic acid, etc. Silver salt of thioglycolic acid, silver salt of dithiocarboxylic acid such as silver salt of dithioacetic acid, silver salt of thioamide, 5-
silver salt of carboxy-1-methyl-2-phenyl-4-thiopyridine, silver salt of mercaptotriazine, silver salt of 2-mercaptobenzoxazole,
Silver salt of mercaptooxadiazole, U.S. Patent No.
Silver salts described in 4123274, for example 1,2,4
-Silver salt of 3-amino-5-benzylthio 1,2,4-triazole, which is a mercaptotriazole derivative, the 3-mercaptotriazole derivative described in U.S. Pat.
It is a silver salt of a thione compound such as a silver salt of (2-carboxyethyl)-4-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 No. 44-30270 and Publication No. 45-18416, silver salts of alkyl-substituted benzotriazoles such as benzotriazole silver salts, methylbenzotriazole silver salts, 5- Silver salts of halogen-substituted benzotriazoles such as silver salts of chlorobenzotriazole, silver salts of carboimidobenzotriazoles such as silver salts of butylcarboimidobenzotriazole, 1, 2, 4 described in U.S. Pat. No. 4,220,709; Examples include silver salts of -triazole and 1-H-tetrazole, silver salts of carbazole, silver salts of saccharin, and silver salts of imidazole and imidazole derivatives. In addition, in the present invention, organic metal salts such as silver salts and copper stearate described in Research Disclosure Vol. 170, No. 17029, June 1978 can also be used as well as the various silver salts mentioned above. It can be used. Two or more types of organic silver salt oxidizing agents can be used in combination. Although the thermal development process during heating of the present invention is not fully clarified, it can be considered as follows. When a photosensitive material is irradiated with light, a latent image is formed on the photosensitive silver halide. Regarding this,
“The Theory of the
Photographic Process” 3rd Edition page 105~
It is described on page 148. Furthermore, by heating the photosensitive material, the dye-donating substance of the present invention acts as a reducing agent, and uses the latent image nuclei as a catalyst to reduce the silver halide and/or organic silver salt oxidizing agent to form silver. , itself is oxidized. This oxidized dye-donating substance is cleaved to release the dye. In this case, the coexistence of a nucleophilic reagent promotes the dye release reaction. When an organic silver salt oxidizing agent is used in combination, it is necessary that the silver halide and the organic silver salt oxidizing agent exist at a substantially effective distance in order to promptly initiate the reaction. It is desirable that the silver halide and the organic silver salt oxidizing agent exist in the same layer. Development by heating differs from so-called wet development in that the reaction requires time because the diffusion of reactive molecular species is restricted. However, if too much time is spent on heating for development, the thermal reaction in the unexposed areas cannot be ignored and so-called fog occurs, which is undesirable. In the present invention, a hot solvent can be used as one means for improving such disadvantages. The term "thermal solvent" as used herein refers to a non-hydrolyzable organic material that is solid at ambient temperature but exhibits a mixed melting point with other components at or below the heat treatment temperature used. When heat development is performed in the presence of a hot solvent, the development speed can be increased and the image quality can be improved. As such a thermal solvent used in the present invention, a compound that can serve as a solvent for a developer, a compound that is a substance with a high dielectric constant and is known to accelerate the physical development of a silver salt, and the like are useful. Useful heat solvents include polyglycols described in U.S. Pat. No. 3,347,675, such as polyethylene glycol with an average molecular weight of 1,500 to 20,000, derivatives of polyethylene oxide such as oleate ester, beeswax,
Monostearin, -SO ₂ -, high dielectric constant compounds with -CO- groups, such as acetamide, succinimide, ethyl carbamate, urea, methylsulfonamide, ethylene carbonate, polar substances described in U.S. Pat. No. 3,667,959, 4-hydroxy Butanoic acid lactone, methylsulfinylmethane,
Tetrahydrothiophene-1,1-dioxide, 1,10-decanediol described in Research Disclosure, December 1976, pages 26 to 28, methyl anisate, biphenyl suberate, and the like are preferably used. Although the role of the thermal solvent in the present invention is not necessarily clear, it is understood that its main role is to promote the diffusion of reactive molecular species during development. The photosensitive silver halide, organic silver salt oxidizing agent of the present invention is prepared in the following binder. A 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. A hydrophilic binder can be used for this binder. Hydrophilic binders are typically transparent or translucent hydrophilic colloids, such as proteins such as gelatin, gelatin derivatives, cellulose derivatives, starch, gum arabic, pullulan, etc.
These include natural substances such as polysaccharides such as dextrins, and synthetic polymeric substances 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. The silver halide used in the present invention may be spectrally sensitized with methine dyes and others. The pigments used include cyanine pigments, merocyanine pigments, composite cyanine pigments, composite merocyanine pigments,
Holopolar cyanine dye, hemicyanine dye,
Included are styryl dyes and hemioxonol dyes. Particularly useful dyes are those belonging to the cyanine dyes, merocyanine dyes and complex merocyanine dyes. Any of the nuclei commonly used for cyanine dyes can be used as the basic heterocyclic nucleus for these dyes. That is, pyrroline nucleus, oxazoline nucleus, thiazoline nucleus, pyrrole 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 Nucleus, quinoline nucleus, etc. can be applied. These nuclei may be substituted on carbon atoms. The merocyanine dye or composite merocyanine dye includes a nucleus having a ketomethylene structure, such as a pyrazolin-5-one nucleus, a thiohydantoin nucleus, a 2-thioxazolidine-2,4-dione nucleus, a thiazolidine-2,4-dione nucleus, a rhodanine nucleus, A 5- to 6-membered heteroartic ring nucleus such as a thiobarbituric acid nucleus can be applied. Useful sensitizing dyes include, for example, German patent no.
929080, U.S. Patent No. 2231658, U.S. Patent No. 2493748
No. 2503776, No. 2519001, No. 2519001, No. 2503776, No. 2519001, No.
No. 2912329, No. 3656959, No. 3672897, No. 3694217, No. 4025349, No. 4046572,
British Patent No. 1242588, Special Publication No. 14030/1973, No. 52
-24844 can be mentioned. These sensitizing dyes may be used alone or in combination, and combinations of sensitizing dyes are often used particularly for the purpose of supersensitization.
Representative examples are U.S. Patent No. 2688545 and U.S. Patent No. 2977229.
No. 3397060, No. 3522052, No. 3522052, No. 3397060, No. 3522052, No.
No. 3527641, No. 3617293, No. 3628964, No. 3666480, No. 3672898, No. 3679428,
Same No. 3703377, Same No. 3769301, Same No. 3814609,
No. 3837862, No. 4026707, British Patent No.
No. 1344281, No. 1507803, Special Publication No. 43-4936,
No. 53-12375, JP-A No. 52-110618, No. 52-
Described in No. 109925. 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
No. 3,635,721), aromatic organic acid formaldehyde condensates (e.g., U.S. Pat.
3743510), cadmium salts, azaindene compounds, etc. US Patent No.
The combinations described in No. 3615613, No. 3615641, No. 3617295, and No. 3635721 are particularly useful. In the present invention, various dye-releasing aids can be used in various ways, for example, by incorporating them into any layer of the light-sensitive material or any layer of the dye-fixing material. A dye-releasing aid is a dye-donating substance that promotes the redox reaction between a photosensitive silver halide and/or organic silver salt oxidizing agent and a dye-donating substance, or is oxidized in the subsequent dye-releasing reaction. In addition, a base or a base precursor is used as a substance capable of acting nucleophilically to promote dye release. In the present invention, it is particularly advantageous to use these dye-releasing aids in order to accelerate the reaction, but when these dye-releasing aids are included in the light-sensitive material, they do not impair the storage stability of the light-sensitive material. You have to choose something in particular. Examples of preferable bases that can be used in photosensitive materials include amines, including trialkylamines, hydroxylamines, aliphatic polyamines, N-alkyl substituted aromatic amines, and N-hydroxyalkyl amines. Mention may be made of substituted aromatic amines and bis[p-(dialkylamino)phenyl]methanes. U.S. Pat. No. 2,410,644 describes tetramethylammonium betaine iodide and diaminobutane dihydrochloride, and U.S. Pat. No. 3,506,444 describes organic compounds containing amino acids such as urea and 6-aminocaproic acid, which are useful. The base precursor releases a basic component when heated. Examples of typical base precursors are described in British Patent No. 998949. Preferred base precursors are salts of carboxylic acids and organic bases; useful carboxylic acids include trichloroacetic acid, trifluoroacetic acid; useful bases include guanidine, piperidine, morpholine, p-
Examples include toluidine and 2-picoline. US Patent No.
Guanidine trichloroacetic acid described in No. 3220846 is particularly useful. Aldonamides described in JP-A-50-22625 are preferably used because they decompose at high temperatures to produce bases. These dye release aids can be used in a wide variety of ways. The useful range is 50% by weight or less of the applied dry film of the photosensitive material, preferably
It ranges from 0.01% to 40% by weight. In the heat-developable light-sensitive material of the present invention, it is particularly advantageous to use a compound represented by the following general formula because development is accelerated and dye release is also promoted. [General formula] In the above formula, A ₁ , A ₂ , A ₃ , and A ₄ may be the same or different, and each represents a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, a substituted aryl group, and Represents a substituent selected from heterocyclic residues, and also represents A ₁ and
A ₂ or A ₃ and A ₄ may be linked to form a ring. Specific examples include H ₂ NSO ₂ NH ₂ , H ₂ NSO ₂ N
( _{CH3 ) 2 , H2NSO2N} ( _{C2H5 ) 2} , _{H2NSO2NHCH3 ,
H2NSO2N ( C2H4OH ) 2 , CH3NHSO2NHCH3 ,} etc. The above compounds can be used in a wide range of applications. A useful range is 20% by weight of the coated dry film of the photosensitive material, more preferably 0.1 to 20% by weight.
It is 15% by weight. In the present invention, it is advantageous to use a water-releasing compound because it accelerates the dye-releasing reaction. A water-releasing compound is a compound that decomposes and releases water during thermal development. These compounds are particularly known for transfer printing of textiles, and are
NH ₄ Fe(SO ₄ ) 2.12H ₂ O described in _Publication No. 88386 is useful. The support for the photosensitive material used in the present invention is one that can withstand processing temperatures. Common supports include glass, paper, metal and their analogs, as well as cellulose acetate film, cellulose ester film, polyvinyl acetal film, polystyrene film, polycarbonate film, polyethylene terephthalate film and related materials. Includes film or resin materials. US Patent No.
The polyesters described in No. 3634089 and No. 3725070 are preferably used. Particularly preferably, polyethylene terephthalate film is used. The coating solution used in the present invention can be prepared by mixing separately formed silver halide and organometallic salt oxidizing agent before use, but it is also possible to prepare the coating solution by mixing the two separately. Mixing in a ball mill for hours is also effective. Also effective is a method in which a halogen-containing compound is added to the prepared organic silver salt oxidizing agent to form halogen silver with the silver in the organic silver salt oxidizing agent. For information on how to make these silver halides and organic silver salt oxidizing agents, how to mix them, etc., see Research Disclosure No. 17029 and JP-A-1973
No. 32928, No. 51-42529, U.S. Patent No. 3700458,
It is described in JP-A-49-13224, JP-A-50-17216, etc. In the present invention, the coating amount of photosensitive silver halide and organic silver salt oxidizing agent is 50 mg in total in terms of silver.
~10g/ ^m2 is suitable. 8. The photographic emulsion layer or other hydrophilic colloid layer of the light-sensitive material of the present invention may contain a coating aid, antistatic property, slip property improvement, emulsification dispersion, adhesion prevention, and photographic property improvement (for example, development acceleration, high contrast, sensitization). Various surfactants may be included for various purposes such as. For example, saponins (steroids), alkylene oxide derivatives (e.g. polyethylene glycol, polyethylene glycol/polypropylene glycol condensates, polyethylene glycol alkyl ethers or polyethylene glycol alkyl aryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycols Nonionic surfactants such as alkylamines or amides, polyethylene oxide adducts of silicone), glycidol derivatives (e.g. alkenylsuccinic acid polyglycerides, alkylphenol polyglycerides), fatty acid esters of polyhydric alcohols, alkyl esters of sugars, etc. agent; alkyl carboxylate,
Alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, alkyl phosphates, N-acyl-N-alkyl taurines, sulfosuccinates, sulfoalkyl polyoxyethylene alkyl phenyl Anionic surfactants containing acidic groups such as carboxy groups, sulfo groups, phospho groups, sulfate ester groups, phosphoric ester groups such as ethers, polyoxyethylene alkyl phosphates; amino acids, aminoalkylsulfonic acids Ampholytic surfactants such as , aminoalkyl sulfates or phosphates, alkyl betaines, and amine oxides; heterocyclic quaternary surfactants such as alkylamine salts, aliphatic or aromatic quaternary ammonium salts, pyridinium, imidazolium, etc. Cationic surfactants such as ammonium salts and phosphonium or sulfonium salts containing aliphatic or heterocycles can be used. Among the above-mentioned surfactants, it is preferable to include a polyethylene glycol type nonionic surfactant having an ethylene oxide repeating unit in the molecule in the photosensitive material. Particularly preferred are those having 5 or more repeating units of ethylene oxide. Nonionic surfactants that meet the above conditions are
It is widely used outside the field, and its structure, properties, and synthesis method are well known. Representative known documents include Surfactant Science Series
Volume 1.Nonionic Surfactants (Edited by
Martin J. Shick, Marcel Dekker Inc.1967),
Surface Active Ethylene Oxide Adducts
(Schoufeldt.N, Pergamon Press 1969), and the nonionic surfactants described in these documents that satisfy the above conditions are preferably used in the present invention. These nonionic surfactants can be used alone,
It can also be used as a mixture of two or more types. The polyethylene glycol type nonionic surfactant is used in an amount equal to or less than the weight of the hydrophilic binder, preferably 50% or less. The photosensitive material of the present invention can contain a cationic compound having a pyridinium salt. An example of a cationic compound with a pyridinium group is
PSA Journal, Section B36 (1953),
USP2648604, USP3671247, Special Publication Showa 44-30074,
It is described in Special Publication No. 44-9503, etc. In the light-sensitive material used in the present invention, a compound that activates development and simultaneously stabilizes the image can be used. Among them, isothiuroniums represented by 2-hydroxyethyl isothiuronium and trichloroacetate described in U.S. Pat. No. 3,301,678, and 1,8-(3,
Bisisothiuroniums such as 6-dioxaoctane)bis(isothiuronium trifluoroacetate), thiol compounds described in West German Patent No. 2162714, and 2-amino-2-thiazolium trichloro described in U.S. Patent No. 4012260. acetate, thiazolium compounds such as 2-amino-5-bromoethyl-2-thiazolium trichloroacetate, bis(2
-amino-2-thiazolium)methylenebis(sulfonylacetate), 2-amino-2-thiazolium phenylsulfonylacetate, etc. Compounds having α-sulfonylacetate as an acidic moiety; , compounds having 2-carboxycarboxamide as the acidic moiety, etc. are preferably used. In the case of the present invention, since the dye-providing substance is colored, it is not so necessary to further include anti-irradiation, anti-halation substances, or various dyes in the light-sensitive material; In order to improve the degree of
No. Publication, U.S. Patent No. 3253921, U.S. Patent No. 2527583,
As stated in each specification such as No. 2956879,
It can contain filter dyes, absorbent substances, etc. These dyes are preferably thermally decolorizable, such as those described in US Pat. Nos. 3,769,019, 3,745,009, and 3,615,432. The photosensitive material used in the present invention may optionally contain various additives known as heat-developable photosensitive materials and layers below the photosensitive layer, such as an antistatic layer, a conductive layer, a protective layer, an intermediate layer, an AH It can contain layers, release layers and the like. Various additives include those described in Research Disclosure Magazine Vol. 170, No. 17029, June 1978, such as plasticizers, sharpness improving dyes, AH dyes, sensitizing dyes,
Additives include matting agents, surfactants, fluorescent whitening agents, and anti-fading agents. In the present invention, similar to the heat-developable photosensitive layer, coating solutions for the dye fixing layer, protective layer, intermediate layer, undercoat layer, back layer, and other layers are prepared for each layer, and are coated using the dipping method, air knife method, curtain coating method, etc. A light-sensitive material can be prepared by sequentially coating onto a support by various coating methods, such as a coating method or a hopper coating method described in US Pat. No. 3,681,294, and drying. Furthermore, if desired, two or more layers can be applied simultaneously by the methods described in US Pat. No. 2,761,791 and British Patent No. 837,095. In the present invention, the latent image obtained after exposure to a light-sensitive material is exposed to light over the entire element for about 0.5 seconds to about 300 seconds at a moderately elevated temperature, e.g. It can be developed by heating. As long as the temperature is within the above range, it can be used at either high or low temperatures by increasing or shortening the heating time. Especially about 110℃~approx.
A temperature range of 160°C is useful. As the heating means, ordinary means such as a simple hot plate, an iron, a hot roller, a heating element using carbon, titanium white, etc., or a similar method can be used. In the present invention, a specific method for forming a color image by thermal development is to move a hydrophilic mobile dye. To this end, the photosensitive material of the present invention comprises a photosensitive layer () containing at least silver halide, optionally an organic silver salt oxidizing agent and a dye-donating substance which is also a reducing agent thereof, and a binder on a support; It consists of a dye-fixing layer ( ) that can accept the hydrophilic and mobile dye formed by the layer ( ). The above-mentioned photosensitive layer () and dye fixing layer () are:
They may be formed on the same support or on separate supports. The dye fixing layer ( ) and the photosensitive layer ( ) can also be peeled off. For example, after imagewise exposure, uniform heat development can be carried out, and then the dye fixing layer (2) or the photosensitive layer can be peeled off. In addition, when a photosensitive material in which a photosensitive layer () is coated on a support and a fixing material in which a fixing layer () is coated on a support are formed separately, the photosensitive material is imagewise exposed to uniform light. After heating, the fixing material can be layered to transfer the mobile dye to the fixing layer (). There is also a method in which only the photosensitive material (2) is imagewise exposed, and then a dye fixing layer (2) is superimposed and uniformly heated. The dye fixing layer ( ) can contain, for example, a dye mordant for dye fixation. Various mordants can be used as the mordant, and polymer mordants are particularly useful. In addition to mordants, bases,
It may also contain a base precursor, etc., and a hot solvent. In particular, when the photosensitive layer (2) and the dye fixed layer (2) are formed on different supports, it is particularly useful to include a base or a base precursor in the fixed layer (2). The polymer mordants used in the present invention are polymers containing secondary and tertiary amino groups, polymers having nitrogen-containing heterocyclic moieties, polymers containing these quaternary cation groups, etc., and have a molecular weight of 5,000 to 200,000, particularly 10,000 to 10,000. 50,000. For example, US Patent No. 2548564, US Patent No. 2484430, US Patent No.
Vinylpyridine polymers and vinylpyridinium cationic polymers disclosed in U.S. Patent Nos. 3148061 and 3756814;
Polymer mordants capable of crosslinking with gelatin etc. disclosed in US Pat. No. 3859096, US Pat.
No. 2798063, Japanese Unexamined Patent Publication No. 115228, No. 54-
Aqueous sol-type mordant disclosed in No. 145529, No. 54-126027, etc.; Water-insoluble mordant disclosed in U.S. Pat. No. 3,898,088; U.S. patent
A reactive mordant capable of forming a covalent bond with the dye disclosed in the specification of No. 4168976 (Japanese Unexamined Patent Publication No. 137333/1983);
No. 3642482, No. 3488706, No. 3557066, No.
No. 3271147, No. 3271148, JP-A-50-71332,
No. 53-30328, No. 52-155528, No. 53-125,
The mordant disclosed in the specification of 53-1024 can be mentioned. Other mordants described in US Pat. No. 2,675,316 and US Pat. No. 2,882,156 can also be mentioned. Among these mordants, for example, those that crosslink with the matrix such as gelatin, water-insoluble mordants, and aqueous sol (or latex dispersion) type mordants can be preferably used. Particularly preferred polymer mordants are shown below. (1) Groups that have a quaternary ammonium group and can be covalently bonded to gelatin (for example, aldehyde groups, chloroalkanoyl groups, chloroalkyl groups, vinylsulfonyl groups, pyridinium propionyl groups,
Polymers having vinylcarbonyl groups, alkylsulfonoxy groups, etc.) For example, (2) A reaction product of a copolymer consisting of a repeating unit of a monomer represented by the following general formula and a repeating unit of another ethylenically unsaturated monomer, and a crosslinking agent (eg, bisalkanesulfonate, bisarenesulfonate).

[Formula] R ^b ₁ : H, alkyl group R ^b ₂ : H, alkyl group, aryl group Q: divalent group R ^b ₃ , R ^b ₄ , R ^b ₅ : alkyl group, aryl group, or
At least two of R ^b ₃ to R ^b ₅ may be combined to form a heterocycle. X: Anion (The above alkyl groups and aryl groups include substituted ones.) (3) Polymer represented by the following general formula x: about 0.25 to about 5 mol% y: about 0 to about 90 mol% z: about 10 to about 99 mol% A: monomer having at least two ethylenically unsaturated bonds B: copolymerizable ethylenically unsaturated Monomer Q: N, P R ^b ₁ , R ^b ₂ , R ^b ₃ : Alkyl group, cyclic hydrocarbon group, or at least two of R ^b ₁ to ^{R b} ₃ may be combined to form a ring . (These groups and rings may be substituted.) (4) Copolymer consisting of (a), (b) and (c)

[Formula] or

[Formula] 3
Water-insoluble polymer having more than R ^b ₁ , R ^b ₂ , R ^b ₃ : Each represents an alkyl group, and R ^b ₁
~Those in which the total number of carbon atoms in R ^b ₃ is 12 or more. (The alkyl group may be substituted.) X: Anion Various known gelatins can be used as the gelatin used in the mordant layer. For example, it is also possible to use gelatin manufactured by different methods such as lime-treated gelatin and acid-treated gelatin, or gelatin obtained by chemically modifying the obtained gelatin such as phthalation or sulfonylation. Moreover, if necessary, it can be used after being subjected to desalting treatment. The mixing ratio of the polymer mordant and gelatin of the present invention and the coating amount of the polymer mordant can be easily determined by those skilled in the art depending on the amount of dye to be mordanted, the type and composition of the polymer mordant, and the image forming process to be used. However, the mordant/gelatin ratio is 20/80 to 80/20 (weight ratio), and the amount of mordant applied is 0.5
Preferably it is used at ~8 g/ ^m2 . A typical fixative material used in the present invention is obtained by mixing a polymer containing an ammonium salt with gelatin and coating it on a transparent support. The dye fixing layer () may have a white reflective layer. For example, a layer of titanium dioxide dispersed in gelatin can be provided on a mordant layer on a transparent support. The titanium dioxide layer forms a white opaque layer, and by viewing the transferred color image from the transparent support side, a reflective color image can be obtained. A dye transfer aid can be used to transfer the dye from the photosensitive layer to the dye fixed layer. As the dye transfer aid, water or a basic aqueous solution containing caustic soda, caustic potash, or an inorganic alkali metal salt is used. Also used are low boiling point solvents such as methanol, N,N-dimethylformamide, acetone and diisobutyl ketone, or mixed solutions of these low boiling point solvents and water or basic aqueous solutions. The dye transfer aid may be used by moistening the image-receiving layer with a solvent, or may be incorporated into the material in the form of crystal water or microcapsules. As the dye transfer aid, a hydrophilic heat solvent can also be used in addition to the above-mentioned solution system. In the present invention, a "hydrophilic thermal solvent" is a compound that is in a solid state at room temperature but becomes a liquid state when heated, and has an (inorganic/organic) value>1, and
It is defined as a compound with one or more solubility in water at room temperature. Inorganicity and organicity are concepts for predicting the properties of compounds, and the details thereof are described in, for example, Chemistry Region 11, p. 719 (1957). Since the hydrophilic thermal solvent has the role of assisting the movement of the hydrophilic dye, it is considered that it is preferably a compound that can act as a solvent for the hydrophilic dye. It is generally known from experience that preferred solvents for dissolving organic compounds have an (inorganic/organic) value close to the (inorganic/organic) value of the organic compound. On the other hand, the (inorganic/organic) value of the dye-donating substances used in the present invention is approximately 1, and the (inorganic/organic) value of the hydrophilic dyes that are separated from these dye-donating substances. teeth,
It has a value larger than the (inorganic/organic) value of the dye-donating substance, preferably 1.5 or more, particularly preferably 2 or more. The hydrophilic thermal solvent used in the present invention is preferably one that moves only the hydrophilic dye and does not move the dye-providing substance, so its (inorganic/organic) value is /organic) value. That is, as a hydrophilic thermal solvent,
It is an essential condition that the (inorganic/organic) value is 1 or more, preferably 2 or more. On the other hand, from the viewpoint of molecular size, it is considered preferable that molecules that can move by themselves without inhibiting the movement exist around the moving dye. Therefore, the molecular weight of the hydrophilic heat solvent is preferably small, about 200 or less, and more preferably about 100 or less. Heating for dye migration improves the storage stability of photosensitive materials,
From the viewpoint of workability, etc., the temperature is between 60℃ and 250℃, so
In the present invention, it is possible to appropriately select a solvent that can function as a hydrophilic thermal solvent within this temperature range. It goes without saying that hydrophilic thermal solvents must be able to quickly assist the movement of dyes upon heating, but if we also consider the heat resistance of photosensitive materials, the requirements for hydrophilic thermal solvents are The melting point is 40
The temperature is preferably 40°C to 200°C, more preferably 40°C to 150°C. Examples of such hydrophilic heat solvents include ureas, pyridines, amides, sulfonamides,
Examples include imides, alcohols, oximes, and other heterocycles. The hydrophilic thermal solvent used in the present invention inhibits the movement of hydrophilic dyes generated by heat development to the dye fixing layer.
It is sufficient that it can substantially help, so it can not only be included in the dye fixing layer, but also
It can be contained in a photosensitive material such as a photosensitive layer, or it can be contained in both a dye fixing layer and a photosensitive layer.
Alternatively, an independent layer containing a hydrophilic thermal solvent can be provided in the photosensitive material or in an independent dye fixing material having a dye fixing layer. From the viewpoint of increasing the transfer efficiency of the dye to the dye fixing layer, it is preferable that the hydrophilic thermal solvent is contained in the dye fixing layer and/or the layer adjacent thereto. The hydrophilic thermal solvent is usually dissolved in water and dispersed in the binder, but it can also be used dissolved in alcohols, such as methanol, ethanol, etc. The hydrophilic thermal solvent used in the present invention is 5 to 500% by weight, preferably 20 to 200% by weight, particularly preferably 20 to 200% by weight of the total coating amount of the photosensitive material and/or dye fixing material
It can be used in a coating amount of 30 to 150% by weight. When the dye fixing layer is located on the surface, a protective layer can be further provided if necessary. As such a protective layer, one generally used as a protective layer for photosensitive materials can be used as is, but if the dye fixing layer is provided on the dye fixing material separately from the photosensitive material, In order not to inhibit the movement of the hydrophilic dye, it is preferable to impart hydrophilicity to the protective layer as well. The photographic light-sensitive material and dye-fixing material of the present invention include:
The photographic emulsion layer and other binder layers may contain an inorganic or organic hardener. Examples include chromium salts (chromium alum, chromium acetate, etc.), aldehydes (formaldehyde, glyoxal, glutaraldehyde, etc.), N-methylol compounds (dimethylol urea, methyloldimethylhydantoin, etc.), dioxane derivatives (2,3-dihydroxydioxane, etc.) ), activated vinyl compound (1,3,5
-triacryloyl-hexahydro-s-triazine, 1,3-vinylsulfonyl-2-propanol, etc.), active halogen compounds (2,4-dichloro-6-hydroxy-s-triazine, etc.), mucohalogen acids (mucochloric acid, mucophenoxychloric acid, etc.), etc. can be used alone or in combination. Further, as the heating means for moving the dye, various means similar to the heating means used in heat development as described above can be employed. In the present invention, various exposure means can be used. The latent image is obtained by imagewise exposure to radiation, including visible light. Generally, light sources used for normal color printing include tungsten lamps, mercury lamps, halogen lamps such as iodine lamps, xenon lamps, laser light sources, and CRTs.
A light source, a fluorescent tube, a light emitting diode, etc. can be used as the light source. The original drawing may be a line image such as a technical drawing, or a photographic image with gradation. It is also possible to photograph portraits of people and landscapes using a camera. The printing from the original drawing may be carried out by contact printing over the original drawing, reflection printing, or enlargement printing. In addition, images taken with a video camera, etc., and image information sent from a television station can be directly transmitted to a CRT or
It is also possible to print the image on a heat-developable photosensitive material by exposing it to a FOT and then forming the image on a heat-developable photosensitive material either in close contact or through a lens. Furthermore, LEDs (light emitting diodes), which have recently seen significant progress, are being used as exposure means or display means in various devices. this
It is difficult to make LEDs that emit blue light effectively, so in order to reproduce color images using LEDs, three types of LEDs that emit green, red, and infrared light are used. The portions of the photosensitive material that are sensitive to light may be designed to emit yellow, magenta, and cyan dyes, respectively. That is, the green-sensitive portion (layer) may contain a yellow dye-providing substance, the red-sensitive portion (layer) may contain a magenta dye-providing substance, and the infrared-sensitive portion (layer) may contain a cyan dye-providing substance. . Other combinations are possible as required. In addition to the method described above, in which the original drawing is directly attached or projected, the original drawing illuminated by a light source is read by a light receiving element such as a phototube or CCD, and this information is stored in a memory such as a computer and processed as necessary. After performing so-called image processing, this image information is reproduced on a CRT and used as an image-like light source, or there is a method of directly causing three types of LEDs to emit light based on the processed information and exposing the image. . <<Effects of the Invention>> When the heat-developable photosensitive material of the present invention is used,
The obtained dye image is extremely good because the developing time can be shortened, the dye image has a high density, and there is no fog. In addition, since the photosensitive material of the present invention has extremely good storage stability before heat development,
It is an extremely easy-to-use photosensitive material that can eliminate variations in image reproducibility. The image forming method using the photosensitive material of the present invention having such characteristics can meet not only the field of photography but also the recent demand for converting so-called soft images to hard images. The formed dye image is fixed on the dye fixing layer, so
The present invention surpasses conventional photographic technology in that it has good color reproducibility and good image storage stability, so it can be easily used even when long-term storage is required. It has great significance. <<Examples>> The present invention will be described in more detail below with reference to Examples, but the present invention is not limited thereto. Example 1 40 g of gelatin and 26 g of KBr were dissolved in 3000 ml of water. This solution was kept at 50°C and stirred. Then silver nitrate
A solution of 34 g dissolved in 200 ml of water was added to the above solution over a period of 10 minutes. Then, add 3.3g of potassium iodide to water.
A solution of 100 ml was added over 2 minutes. The pH of the silver iodobromide emulsion thus prepared was adjusted, the pH was adjusted to 6.0 after sedimentation, and excess salt was removed.
A yield of 400 g of silver iodobromide emulsion was obtained. Next, how to make a gelatin dispersion of a dye-donating substance will be described. Dispersion containing the auxiliary developer precursor of the present invention (A) 5 g of magenta dye-donating substance (10), 0.02 g of the auxiliary developer precursor (1) of the present invention, 2-ethyl-hexyl succinate Sodium sulfonate 0.5g,
15 g of tricresyl phosphate (TCP) was weighed out, 30 ml of ethyl acetate was added, and the mixture was heated and dissolved at about 60° C. to form a uniform solution. This solution and 100 g of a 10% solution of lime-treated gelatin were stirred and mixed, and then dispersed using a homogenizer at 10,000 RPM for 10 minutes. This dispersion liquid is called a dispersion (A) of a dye-donating substance (10). Dispersion (B) containing no auxiliary developer precursor Dispersion (B) was prepared using exactly the same procedure as in (A) except that the auxiliary developer precursor (1) of the present invention was removed. Ivy. Next, how to make photosensitive coatings A* and B* will be described. Photosensitive coating A* (a) 25 g of the above silver iodobromide emulsion (b) Dye-donating substance (10) containing auxiliary developer precursor (1)
Dispersion (A) 33g (c) 5% aqueous solution of a compound with the following structure 5ml (d) 12 ml of 10% ethanol solution of guanidine trichloroacetic acid (e) 4 ml of 10% aqueous solution of dimethylsulfamide (f) 8 ml of water After mixing and dissolving above (a) to (f), place on polyethylene terephthalate film. It was applied to a wet film thickness of 30 μm and dried. Furthermore, the following composition was applied as a protective layer thereon. (a) 35 g of a 10% aqueous solution of gelatin (b) 5 ml of a 10% ethanol solution of guanidine trichloroacetic acid (c) 4 ml of a 1% aqueous solution of sodium succinate-2-ethyl-hexyl ester sulfonate (d) A mixture of 56 ml of water It was coated to a wet film thickness of 25 μm and then dried to produce a photosensitive coated material A*. In the preparation of photosensitive coating material A*, instead of the dispersion (A) of the dye-providing substance (10) containing the auxiliary developer precursor, a dispersion of the dye-donating substance (10) that does not contain the auxiliary developer precursor is used. A photosensitive coating material B* was prepared in exactly the same manner except that material (B) was used. Next, apply this coating sample using a tungsten light bulb.
Imagewise exposure was made for 10 seconds at 2000 lux. then 130
The mixture was heated uniformly for 15 seconds on a heat block heated to ℃. Next, a method for forming a dye fixing material containing a dye fixing agent will be described. Poly(methyl acrylate-N,N,N-trimethyl-N-vinylbenzylammonium chloride) (ratio of methyl acrylate and vinylbenzylammonium chloride is 1:1) 10g to 200ml
of water and mixed uniformly with 100 g of 10% lime-treated gelatin. This mixture was placed on a paper support laminated with polyethylene in which titanium dioxide was dispersed.
It was applied uniformly to a wet film thickness of 90 μm. After immersing this dye-fixing material in water, overlap the heated photosensitive materials A* and B* mentioned above so that the film surfaces are in contact with each other, and heat for 6 seconds on a heat block at 80°C. The material was peeled off to obtain a magenta color image on the dye fixing material. The reflection density of this negative image was measured using a Macbeth densitometer (RD-519) and the following results were obtained.

[Table] These results demonstrate that the photosensitive material of the present invention using the auxiliary developer precursor can obtain high image density in a short thermal development time. Example 2 A dispersion of the dye-donating substance (10) was prepared by carrying out exactly the same operation as in Example 1, except that the following compound was used instead of the auxiliary developer precursor (8) used in Example 1.
(C), (D), (E), (F), and (G) were prepared. Next, (C) ~ (G)
Using the dispersion, photosensitive coatings (C*, D*, E*, F*, G*) were prepared in the same manner as in Example 1. The same treatment as in Example 1 was carried out using these photosensitive coatings. The results obtained are shown below.

[Table] The above results demonstrate that high image density can be obtained in a short heating time when the photothermographic material of the present invention containing an auxiliary developer precursor is used. Example 3 Using the following dye-donating substances instead of the dye-donating substance (10) used in Example 1, dyes each containing an auxiliary developer precursor (1) were prepared in the same manner as in Example 1. A dispersion of a donor substance and a dispersion of a dye-donor substance containing no auxiliary developer precursor were prepared. Dye-donating substance (42) 5g Dispersion (H) Dye-donating substance (68) 7.5g Dispersion (I) Dye-donating substance (21) 5g Dispersion (J) In exactly the same manner as in Example 1. A sample was prepared and treated in the same manner as in Example 1, and the results obtained are shown below.

[Table] These results demonstrate that the photothermographic material of the present invention provides high density in a short heating time. Example 4 Next, an example using an organic silver salt oxidizing agent will be shown. Preparation method of benzotriazole silver emulsion: Add 28 g of gelatin and 13.2 g of benzotriazole to water.
It was dissolved in 3000 ml, and this solution was kept at 40°C and stirred. A solution prepared by dissolving 17 g of silver nitrate in 100 ml of water was added to this solution over a period of 2 minutes. Adjust the pH of this benzotriazole silver emulsion,
After sedimentation and removal of excess salt, the pH was adjusted to 6.0, yielding 400 g of benzotriazole silver emulsion. The following photosensitive coatings were prepared using this benzotriazole silver emulsion. (a) Silver benzotriazole emulsion 10g (b) Silver iodobromide emulsion 20g (c) Dye-donating substance (10) containing auxiliary developer precursor (1)
Dispersion (A) 33g (d) 5% aqueous solution of a compound with the following structure 5ml (e) 12.5 ml of 10% ethanol solution of guanidine trichloroacetic acid (f) 4 ml of 10% aqueous solution of dimethylsulfamide (g) After dissolving 7.5 ml of water, mix and dissolve on polyethylene terephthalate film to a wet film thickness of 30 μm. was applied and then dried. The protective layer is coating material A*
It was coated using the same method. This is referred to as photosensitive coating A**. In the method of preparing a photosensitive coating A**, a dispersion (A) of a dye-donating substance (10) containing an auxiliary developer precursor (1)
Photosensitive coating material B** was prepared in exactly the same manner except that dispersion (B) of dye-donating substance (10) containing no auxiliary developer precursor was used instead. Using this photosensitive coating, the same treatment as in Example 1 was carried out, and the results obtained are shown below.

[Table] These results demonstrate that the photothermographic material of the present invention is effective in producing a high maximum density in a short processing time. Example 5 Photosensitive materials A*, B* of Example 1 and photosensitive materials C*, D*, E*, F*, G* of Example 2 were coated immediately after coating and placed in a constant temperature container at 50°C for 2 days. After saving,
Exposure, heating, and transfer were performed in the same manner as in Example 1, and the reflection density with respect to green light was measured. The results obtained are shown below.

[Table] The above results demonstrate that the photothermographic material containing the auxiliary developer precursor of the present invention suppresses the increase in minimum density during storage and improves stability over time. Example 6 In the preparation of photosensitive coating material A*, a dye-donating product containing 0.01 g of the following auxiliary developer (h) instead of the dispersion of the dye-providing substance (10) containing the auxiliary developer precursor (1) A photosensitive coating H* was prepared in exactly the same manner except that a dispersion (H) of substance (10) was used. Immediately after coating the photosensitive materials A*, B* and the above H* of Example 1 and after storing them in a constant temperature container at 50°C for 2 days, they were exposed, heated and transferred in the same manner as in Example 1 to determine the reflection density for green light. was measured. The results obtained are shown below.

[Table] From the above results, in the sample containing the developing agent precursor according to the present invention, the sensitivity increases immediately after coating, and even after aging the photosensitive material, the sensitivity increases without an increase in Dmin. It has been proven that there is. Example 7 This example is a case in which a dye fixing material suitable for completely dry image formation is used. As photosensitive materials, photosensitive coatings A* and B* of Example 1 were used. Next, a method for forming a dye fixing material containing a dye fixing agent will be described. Poly(methyl acrylate-N,N,N-trimethyl-N-vinylbenzylammonium chloride) (ratio of methyl acrylate and vinylbenzylammonium chloride is 1:1) 10g to 200ml
of water and mixed uniformly with 100 g of 10% lime-treated gelatin. This mixed solution was uniformly applied onto a polyethylene terephthalate film having a thickness of 120 μm in which titanium dioxide was dispersed to a wet film thickness of 90 μm. On this layer containing the dye fixing agent, the following (a) to (f) were mixed and dissolved, and a solution (referred to as solution A) was uniformly applied to a wet film thickness of 60 μm. (a) 2 g of urea (b) 2 g of N-methylurea (c) 10 ml of water (d) 10% of polyvinyl alcohol (saponification degree 98%)
Weight% aqueous solution 12g (e) Compound with the following structure 100mg (f) 0.5 ml of 5% aqueous solution of sodium dodecylbenzenesulfonate This coated sample was dried and used as a dye fixing material. Using the above photosensitive material with a tungsten light bulb,
Imagewise exposure was made for 10 seconds at 2000 lux. then 130
Heat for 15 seconds on a heat block heated to .degree. This heated photosensitive material and the dye-fixing material described above are layered so that their film surfaces are in close contact with each other, and after heating for 20 seconds on a heat block at 140°C, the dye-fixing material is peeled off from the photosensitive material. A negative magenta image was obtained. The reflection density of this negative image is measured using a Macbeth densitometer (RD).
-519) and obtained the following results. Photosensitive material Maximum density Minimum density A* (invention) 2.08 0.20 B* (comparison) 1.25 0.18 From these results, the heat-developable photosensitive material of the invention is as good as in Example 1 even in the completely dry image forming process. It has been demonstrated that good results can be obtained.

Claims (1)

[Scope of Claims] 1. On a support, at least a photosensitive silver halide, a binder, and a compound that is reducible to the photosensitive silver halide and reacts with the photosensitive silver halide by heating. 1. A photothermographic material comprising a dye-donating substance that releases a hydrophilic dye and an auxiliary developer precursor represented by the following general formula. [General formula] In the formula, A represents a group that can be cleaved by alkaline hydrolysis, and R represents an aryl group. R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom, an alkyl group or an aryl group, and may be the same or different. 2. On the support, at least the photosensitive silver halide, the binder, and the photosensitive silver halide are reducible, and when heated, react with the photosensitive silver halide to release a hydrophilic dye. A heat-developable photosensitive material comprising a dye-donating substance and an auxiliary developing agent precursor represented by the following general formula is heated after or simultaneously with image exposure to form an imagewise distribution of a diffusible dye. Characteristic image forming method. [General formula] In the formula, A represents a group that can be cleaved by alkaline hydrolysis, and R represents an aryl group. ^R1 , ^R2 , ^R3
and R ⁴ represent a hydrogen atom, an alkyl group, or an aryl group, and these may be the same or different.