JPS58107534A - Thermodevelopable photosensitive material - Google Patents

Abstract

PURPOSE:To reduce thermal fog remarkably without changing imaging characteristics including photosensitivity, by incorporating a >=6 C aliphatic dicarboxylic acid to a thermodevelopable material contg. a long-chain aliphatic acid, an oxidation-reduction image-forming component, photosensitive silver halide, etc. CONSTITUTION:A thermodevelopable material contains 0.001-4mol aliphatic dicarboxylic acid represented by a formula as shown on the right (R is >=4 straight- or brannched-chain alkylene or alkenylene) per 1mol of a long-chain aliphatic acid silver salt contained in said material. The thermo developable material may be formed in a single layer or multilayers. The dicarboxylic acid is dissolved in a proper solvent and added to the coating liquid of the thermodevelopable photosensitive material or it is added directly to the coating, or it is added to the layer adjacent to the photosensitive material layer, thus permitting thermal fog to be suppressed remarkably without deteriorating characteristics, such as photosensitivity, and fog to be controlled also at temp. higher than that of the conventional process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-developable sensitive material, and in particular, by containing an aliphatic dicarboxylic acid having 4 or more carbon atoms, it can be used without any change in image characteristics such as a decrease in photosensitivity. The present invention relates to a heat-developable sensitive material that significantly reduces thermal fog caused by this phenomenon.

Traditionally used silver halide photography is light sensitive,
It is superior to other photographic methods in terms of gradation, etc., but since the fixing and whitening processes are wet, it is difficult to handle, and it is difficult to mechanize the processing process. There are many disadvantages to doing so. Many attempts have been made to form images by dry processing instead of such silver halide photography. An image forming method using a heat-developable sensitive material in which the developing step is performed by heat treatment has been proposed as a method that is particularly superior to conventional image forming methods.

For example, Japanese Patent Publication No. 43-4924 describes a heat-developable sensitive material consisting of silver halide in catalytic contact with an organic silver salt and an organic silver ion, and similar materials. There are descriptions in Japanese Patent Publication No. 44-26582 and Japanese Patent Publication No. 46-6074. In addition to the above, heat-developable sensitive materials that are activated and made photosensitive by heat treatment before imagewise exposure, and then heated as a whole to form a developed image after imagewise exposure, and their preparation. A method is proposed.

This heat-developable sensitive material consists of a heat-developable sensitive element that does not contain silver halide or does not have any photosensitivity even if it contains silver halide, and is specifically disclosed in Japanese Patent Publication No. 51 Sho. It is described in Japanese Patent Publication No. 29819, Japanese Patent Publication No. 53-41967, and Japanese Patent Publication No. 54-5687.

Heat-developable sensitive materials have the advantage that image formation does not require a wet process, but on the other hand, image characteristics such as sensitivity and fog density are still insufficient compared to conventionally used silver halide photography. do not have. In particular, heat fog tends to occur in unexposed areas (background) during heat development, and the sensitivity to development temperature and development time is a major practical problem.

Various methods have been proposed to improve the drawback of increased heat fog. Japanese Patent Publication No. 47-11113 proposes the inclusion of a mercury compound as a heat fog inhibitor. Although this method exhibits excellent heat fog prevention properties, it is known that it is toxically unfavorable. Furthermore, there is a drawback that the sensitivity of the raw material deteriorates due to storage over time.

Various antifoggants other than mercury compounds have been proposed. For example, JP-A-51-54428 proposes the use of sulfinic acids and phthalic acids in combination, but such a method is undesirable because it causes the disadvantage of coloring when exposed to light after image formation. Also, thiouracils as described in JP-A-51-3223, or polymer acids having a carboxyl group or sulfonic group as in JP-A-51-104338, or as described in JP-A-54-44212. Thiosulfonic acids or JP-A-53-125015
Although methods using various compounds such as benzoic acids have been proposed in the above publication, none of them have been able to provide a better antifogging effect than mercury compounds, which are unfavorable in terms of toxicity.

Therefore, an object of the present invention is to provide a heat-developable photosensitive material that significantly controls thermal fog during development, does not cause changes in image characteristics such as a decrease in sensitivity, has excellent stability over time, and is stable against light after image formation. It is to provide.

The object of the present invention is to provide at least (a) on a support.
A heat-developable sensitive element consisting of an oxidation-reduction image-forming component consisting of a long-chain fatty acid silver salt and a reducing agent and (b) a photosensitive silver halide or (and) a photosensitive silver halide-forming component and (c) a binder. This can be achieved by (d) containing at least one compound represented by the following general formula in a heat-developable sensitive element formed into a layer or multiple layers.

General formula HOOC-R-COOH In the formula, R represents an alkylene group or alkenylene group having 4 or more carbon atoms and which may be linear or branched.

When long-chain fatty acid silver is used as a reducible organic silver salt, the reaction mechanism of thermal fog suppression by the compound of the present invention is not clear, but its remarkable fog suppression properties are due to desensitization,
This was surprising even to the inventors of the present invention, considering that it does not cause any adverse effects such as deterioration of stability over time. In addition, as mentioned above, various proposals have been made regarding the antifogging effect of carboxylic acid groups as antifoggants, but the compound of the present invention has a completely different effect from those; for example, aliphatic monomers. The antifogging properties of carboxylic acids are much weaker than the compounds of the present invention.

In Japanese Patent Publication No. 45-12700, when silver benzotriazole is used as a reducible silver salt, a saturated aliphatic monocarboxylic acid having from 9 to 26 carbon atoms, and a saturated aliphatic monocarboxylic acid having from 4 to 10 carbon atoms are used. The difference in the effect of addition of aliphatic dicarboxylic acid between the conventional invention and the present invention, in which organic acids and their salts such as aliphatic dicarboxylic acids and benzoic acids substituted with hydroxyl groups, are used as heat development accelerating agents is not clear. However, if I were to state it explicitly, it is thought that this is due to the difference in reducibility between benzotriazole silver and long-chain fatty acid silver as reducible organic silver salts.

Next, specific examples of compounds constituting the present invention will be shown, but the invention is not limited thereto.

(1) HOOC (CH2)4 COOH(2) H
OOC (CH2)5 COOH(3) ■ (4) HOOC (CH2)6 COOH(5) H
OOC (CH2)7 COOH(6) ■ (7) ■ (8) HOOC (CH2)8 COOH(9) H
OOC-CH=CH-(CH2)6 COOH(10)
HOOC (CH2) 4 COOH (11) ■ (12) ■ (13) HOOC (CH2) 10 COOH (14)
HOOC CH=CH-(CH2)8 COOH(15
)■ (16) HOOC (CH2) 11 COOH (17)
■ (18) ■ (19) HOOC (CH2) 12 COOH (20)
■ (21) ■ (22) HOOC (CH2) 13 COOH (23)
■ (24) HOOC (CH2) 14 COOH (25)
HOOC (CH2)15 COOH(26)■ (27) HOOC (CH2)16 COOH(28)
HOOC (CH2) 17 COOH (29) HOOC
(CH2)18 COOH(30)HOOC (CH
2) 19 COOH (31) HOOC (CH2) 20
COOH (32) HOOC (CH2) 21 COO
H(33)HOOC (CH2)22 COOH(34
)HOOC (CH2)23 COOH(35)HOO
C (CH2)24 COOH(36)HOOC (C
H2)28 COOH(37)HOOC (CH2)3
2 COOH The method and period of addition of the compound of the present invention are not particularly limited. For example, a method of directly adding the compound dissolved in an appropriate solvent into a coating solution of a heat-developable sensitive material, a method of adding it directly to a heat-developable sensitive material layer, ■Method of adding to the layer in contact with,
Alternatively, a method may be employed in which a heat-developable sensitive material coating solution is applied onto a support, dried, and then the surface is immersed in a solution containing the compound of the present invention. The preferred addition amount range of the compound of the present invention is from 0.001 mol to 4 mol per mol of the reducible organic silver salt, and particularly preferably 0.001 mol to 4 mol per mol of the reducible organic silver salt.
．． The amount ranges from 1 mol to 2 mol. Further, addition of more than necessary is not preferable as it leads to a decrease in the maximum concentration. The heat-developable photosensitive element used in the present invention comprises (a) a redox image-forming component comprising a long-chain fatty acid silver salt and a reducing agent, (b) a photosensitive silver halide or/and a photosensitive silver halide-forming component, and (c) Contains at least a binder, which may be contained in a single layer, but may be multilayered with the long chain fatty acid silver salt and the reducing agent in separate layers, or on or above the single layer. It is also possible to form a multilayer structure in which a layer containing a long-chain fatty acid silver salt or a reducing agent is further provided below. The long-chain fatty acid silver salt of component (a) preferably has 12 to 24 carbon atoms because it is less susceptible to unfavorable changes such as darkening under room light. Specific examples include silver behenate, silver stearate, silver valmitate, silver myristate, silver laurate, silver oleate, and silver hydroxystearate, among which silver behenate is particularly effective. .

Various reducing agents can be used for the oxidation-based image forming component. Generally, developers used in ordinary silver halide photosensitive materials, specifically hydroquinone, methylhydroquinone, clilihydrochinone, methylhydroxynaphthalene, N,N'-jethyl-P-
Examples include phenylenediamine, aminophenol, ascorbic acid, 1-phenyl-3-pyrazolidone, and in addition to these, 2,2'-methylenebis(6-tertiarybutyl-4-methylphenol), 4,4 ´
-butyldenbis (6-tert-butyl-3-methylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol), etc.
Examples include the bisnaphthol-based reducing compounds described in Japanese Patent No. 6-6074, and the 4-benzenesulfonamidophenol compounds described in Belgian Patent No. 802519.

This heat-developable photosensitive element contains silver halides such as silver chloride, silver bromide, silver iodide, silver iodobromide, silver iodochloride, and silver iodochlorobromide in order to particularly impart photosensitivity. There is a need. This silver halide is particularly effective in the form of fine particles, and as a method of adjusting this, a part of the reducible organic silver salt is replaced with a silver halide forming component such as ammonium bromide.
Examples include a method of preparing fine silver halide by halogenation with lithium bromide, atrium chloride, N-bromosuccinimide, or the like. Also, a method of incorporating so-called extra-system silver halide can be used.

This heat-developable photosensitive element containing extra-system silver halide is
For example, it is described in Belgian Patent No. 774436. In other words, apart from the heat-developable photosensitive element, photosensitive silver halide is prepared outside of the oxidation-reduction image-forming components, and then, after preparation, the silver halide is added to the image-forming components and mixed. It is adjusted by

A suitable content of silver halide (or silver halide forming component) is preferably 0.001 per mole of reducible organic salt.
mole to 0.30 mole, more preferably 0.01 mole to 0.30 mole.
It is 15 moles.

The heat-developable photosensitive element according to the present invention may contain a binder alone or in combination in the layer. Suitable materials for the binder can be hydrophobic or hydrophilic, and transparent or translucent. Specifically, polyvinyl butyral, cellulose acetate butyrate, polymethyl methacrylate, polyvinyl pyrrolidone, ethyl cellulose, cellulose acetate, polyvinyl acetate, polyvinyl alcohol, gelatin, and sulfobetaine as described in Canadian Patent No. 774,054. Examples include those having repeating units. The amount of binder used is 10% by weight based on the reducible organic silver salt.
The ratio is preferably from 1:1 to 1:10, more preferably from 4:1 to 1:2.

Furthermore, the heat-developable photosensitive material according to the present invention can be used for image color adjustment,
In order to improve the stability after image formation, it is preferable to use an organic acid, and it is particularly desirable to contain it alone or in combination with a fatty acid that is the same as or near the long-chain fatty acid silver salt.

The amount of these fatty acids used is 2% based on the reducible organic silver salt.
5 mol% to 200 mol%, preferably 30 mol% to 1
20 mol% is preferred.

It may also contain appropriate color adjustments.

Color adjustment for this purpose is described in U.S. Patent No. 3,080,254.
The phthalazinone described in the specification includes derivatives thereof, phthadazinedione compounds described in JP-A-50-6074, and the like.

The heat-developable photosensitive element of the present invention can be used in combination with a thermal fog inhibitor other than the one of the present invention.

As a heat fog preventive agent to be used in combination,
Mercury compound described in Publication No. 113, Japanese Patent Publication No. 55-4237
1,2,4-triazole compounds described in Japanese Patent Application No. 55-105270, benzoic acids described in Japanese Patent Application No. 56-23512, and Japanese Patent Application No. 55-33483. Examples include compounds having a sulfonylthio group.

The heat-developable photosensitive element of the present invention may further contain a development accelerator, a curing agent, an antistatic agent (layer), an ultraviolet absorber, an optical brightener, a filter dye (layer), and the like.

Elements according to the invention may contain suitable spectral sensitizers. Effective sensitizing dyes include cyanine dyes, merocyanine dyes, and xanthene dyes, especially "Product Licensing Index" Vol. 42, Nos. 107 to 110.
Page (published December 1971) or Belgian Patent No. 77
The one described in No. 2371 is useful.

The heat-developable photosensitive element according to the present invention can be coated on a suitable support to obtain a heat-developable photosensitive material. Typical supports include synthetic resin films such as polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, and cellulose acetate, synthetic paper, paper coated with resin films such as polyethylene, art paper, and paper such as photographic Paraita paper. Alternatively, metal plates (foils) such as aluminum, synthetic resin films or glass plates having a metal vapor-deposited film by a conventional method, etc. can be mentioned.

Hereinafter, the present invention will be explained according to Examples, but the present invention is of course not limited thereto.

Example 1 A dispersion liquid was prepared by dispersing 25 g of silver behenate, 300 ml of xylene, and 200 ml of carbutanol using a homomixer. 10 g of polyvinylebutital was added to this dispersion, stirred and dissolved, and then heated to 65°C, and then 25 ml of
N-bromosuccinimide dissolved in acetone of 1.0
g and stirred for 2 hours. Next, 20 g of behenic acid was added and dissolved with stirring, and then the temperature of the dispersion was adjusted to 30° C., and the following components were sequentially added while stirring to obtain a first coating liquid.

1,2,2'-methyllenebis(6-t-butyl-4-
8% by weight of methylphenol) and 20% by weight of polyvinyl butyral in xylene/butanol (1/1 by volume) solution 250ml 2. 6g of example compound (13) 3,3-ethyl-5[(3-methyl-2 -Thiazolylidene)ethylidene] rhodanine in DMF 0.1 solution 1
0 ml of this first coating liquid was applied to realism-like base paper using a roll coater. At this time, the coating amount when dry was 11.5 g/m2. Next, on the coating formed by applying the first coating liquid, a second coating liquid consisting of the following components was applied in layers so that the dry coating amount was 2.5 g/m2, and heat developable properties were obtained. Optical material (I) was prepared.

Second coating liquid Phthalazinone 25g Cellulose acetate 50g Acetone 1,000ml A heat-developable photosensitive material (II) was prepared in the same manner as the heat-developable photosensitive material (I) except that exemplified compound (13) was omitted. Further, a heat-developable photosensitive material (III) was prepared using 20 g of 6 g of Exemplified Compound (13).

Furthermore, the amount of Exemplified Compound (13) was increased to 60 g to prepare a heat-developable photosensitive material (IV).

The above samples were exposed to light at 400 lux for 10 seconds using a 150W tungsten lamp for enlarging as a light source (Kodank Step Tablet No. 2), and heated at 120°C, 125°C, 130°C, 13°C using a heating roller.
Heat development was performed at 5°C, 140°C, and 145°C for 5 seconds each to create an image. The maximum accuracy, fog density, and relative sensitivity were measured and compared from the obtained images.

These results are shown in Table-1. The relative sensitivity shown in the table indicates the relative amount of each sensitivity measured with the point of fog density + 0.1 as a reference (sensitivity was measured in the same manner in the following Examples). ) is expressed as 100 at 130°C.

Table-1 ■ As is clear from Table-1, the compound (15) of the present invention
The heat-developable photosensitive material (I) using the compound (I) exhibits remarkable fog control properties compared to the heat-developable photosensitive material (II) that does not contain the compound (13). Also, heat-developable photosensitive materials (III) and (IV)
As shown in Figure 2, an increase in the amount of Exemplified Compound (13) was accompanied by a decrease in maximum density, but no decrease in sensitivity, demonstrating fog controllability up to a higher temperature development range.

Example 2 Exemplified compound (13) of the heat-developable photosensitive material (I) of Example 1
), 4.2 g of Exemplified Compound (2) was used to prepare a heat-developable photosensitive material (V), 4.9 g of Exemplified Compound (5) was used to prepare a heat-developable photosensitive material (VI), and Exemplified Compound (9) 5. 3g of the heat-developable photosensitive material (VII), the exemplified compound (19)
A heat-developable photosensitive material (VIII) was prepared using 6.7 g of each heat-developable photosensitive material (VIII), exposed as described in Example 1, and heat-developed using a heating roller at 125°C, 130°C, and 135°C for 5 seconds each. The results shown in 2 were obtained. The heat-developable photosensitive material (II) of Example 1 was used as a comparative example.

Table 2 (2) As is clear from Table 2, the fog density was significantly controlled by using the compound of the present invention, and an E heat-developable photosensitive material could be obtained.

Example 3 A heat-developable photosensitive material (IX) was prepared by adding 3.2 g of lauric acid in place of Exemplified Compound (13) in the description of Example 1, and a heat-developable photosensitive material (X) was prepared by adding 5.2 g of lauric acid. , 3.2 g of benzoic acid was added to form a heat-developable photosensitive material (XI), 0.43 g of phthalic acid was added to form a heat-developable photosensitive material (XII), and 4.3 g of phthalic acid was added to form a heat-developable photosensitive material (XIII).
), 0.025 g of thiouracil was added to prepare a heat-developable photosensitive material (XIV), and 0.25 g of thiouracil was added to prepare a heat-developable photosensitive material (XV), and exposed as described in Example 1. 125℃, 130℃
, 135°C for 5 seconds each to produce an image, and the image characteristics were evaluated using the heat-developable photosensitive material described in Example 1
In comparison with I), the results shown in Table 3 were obtained.

Table-3 ■ As shown in Table-3, heat-developable photosensitive materials (IX) and (X) using lauric acid in place of exemplified compound (13)
Further, in the heat-developable photosensitive material (XI) using benzoic acid, no fog control effect was observed, but on the contrary, a development acceleration effect was observed. In addition, heat-developable photosensitive materials (XII) using fluoric acid and (
XIII) In addition, heat-developable photosensitive materials (XIV) and (XV) using thiouracil showed a fog suppressing effect, but were accompanied by significant desensitization. Furthermore, as the amount added increased, the antifogging properties increased, but there was a tendency for further desensitization to occur. Further, heat-developable photosensitive materials (I) and (IX) to (X
After forming an image on V), the room was exposed to a white fluorescent lamp (3000 lux) for 120 hours, and the degree of coloring of the non-image area due to light was observed. Heat-developable photosensitive material (I) of the present invention
showed almost no photodiscoloration, whereas all of the other photosensitive materials used for the ratio changed color to pink, and in particular, the heat-developable photosensitive materials (VIII) and (XV) showed strong photodiscoloration.

Example 4 In place of Exemplified Compound (13) in the heat-developable photosensitive material (I) of Example 1, 200 mg of mercuric acetate was added, and 2 mg of mercuric acetate was added to the heat-developable photo-sensitive material (XVI). 2 mg of mercuric acetate and 4.9 g of Exemplary Compound (5) were added to the heat-developable photo-sensitive material (XVIII) to prepare the heat-developable photo-sensitive material (XVIII). At 120℃, 130℃, 14
Heat development was performed at 0°C, 150°C, and 160°C for 5 seconds, respectively, and the results shown in Table 4 below were obtained. In addition, after storing each sample for 5 days at a temperature of 35°C and a relative temperature of 80%, the exposure solution was heated at 130°C and 150°C using the same method.
Thermal development was performed at ℃ for 5 seconds, and the results shown in Table 5 were obtained.

Table 4 ■ Table 5 ■ As shown in Tables 4 and 5, mercury compounds exhibit the effect of suppressing fog caused by heat development depending on the amount added, but especially when the amount added is large. It was found that significant desensitization occurred over time. Also, heat-developable photosensitive material (XVIII)
As can be seen, when the compound of the present invention is used in combination with a trace amount of a mercury compound, the heat fog suppressing effect is synergistically enhanced and the effect is exhibited over a wide developing temperature range. As shown in Table 5, the amount of mercury used in combination can be extremely small;
Sensitivity decrease over time is extremely small.

Example 5 Silver behenate 25g, behenic acid 20g, xylene 325m
A dispersion liquid was prepared by dispersing 325 ml of 1 and n-butanol using a homomixer. 40 g of polyvinyl butyral was added to this dispersion and dissolved with stirring. Then 50℃
0.25 g of lithium bromide dissolved in 50 ml of methanol was added, and stirring was continued for 2 hours. After 30℃
Adjust the temperature and continue stirring to add 20 g of 2,2' methylenebis (6-t-butyl 4-methylphenol) and 3-ethyl-5
-[(2-methyl-2-deazolilidene)ethylidene]
Add 10 ml of a 0.1% solution of D-danine in DMF to the first
As a coating liquid. This first coating liquid was applied onto photographic base paper using a roll coater. At this time, the amount of application when dry is 9.
It was 0g/m2. Next, on the coating formed by applying the first coating liquid, a second coating liquid consisting of the following components was applied in layers so that the dry coating amount was 2.8 g/m2, and a heat-developable photosensitive material was obtained. Material (XIX) was prepared.

Second coating liquid Phthalazinone 25g Cellulose acetate 50g Exemplified compound (8) 18g Acetone 1000ml A heat-developable photosensitive material (
XX) was produced. The above samples were heated at 120°C and 125°C using a heating roller after exposure according to the description in Example 1.
, 130° C. for 5 seconds to form an image, and the results shown in Table 6 were obtained.

Table 6 (1) As shown in Table 6, images with extremely controlled fog density were obtained by adding the compound of the present invention.

Example 6 3.9 g of silver stearate was mixed with 10 g of isopropyl alcohol.
0 ml and dispersed using a homomixer. 3 g of polyvinyl briral was added to this dispersion and dissolved with stirring to prepare a silver salt polymer suspension dispersion (2). The temperature of this dispersion was heated to 50° C. under a red safety light, and 0.9 g of lithium bromide dissolved in 30 ml of acetone was added dropwise over 1 hour while stirring. After the dropwise addition, the reaction temperature was maintained and stirring was continued for 2 hours. Next, the temperature of the dispersion liquid was lowered to room temperature to obtain a photosensitive silver halide dispersion.

On the other hand, 5 g of silver behenate and 4 g of behenic acid were added to 44 g of xylene.
ml and 44 ml of n-butanol and dispersed in a homomixer, and further, 80 g of polyvinyl butyral was added as a binder and dissolved with stirring to prepare a polymer dispersion of silver salt.

10 g of the photosensitive silver halide dispersion described above was mixed and added to this polymer dispersion. The following components were sequentially added to the thus obtained polymer dispersion of silver behenate containing photosensitive silver halide to prepare a first coating.

A solution of 4 g of 2,2'-methylenebis(6-t-butyl-4-t-thylphenol), 5 ml of xylene, and 5 ml of n-butanol, norcargoxymethyl-5-[(3-ethinaphtho[1,
2-d]oxazolin-2-ylidene)-ethylidene]
-3-Allylthiohydantoin 0.0013g Exemplified Compound (15) 0.12g This first coating liquid was applied onto photographic base paper using a roll coater. At this time, the coating amount upon drying was 10 g/m2. Next, on the coating formed by applying the first coating solution, a second coating solution consisting of the following components was applied in layers so that the dry coating amount was 1.5 g/m2, and heat-developable sensitivity was obtained. Optical material (XXI) was prepared.

Second coating liquid Cellulose acetate 15.0g Phthalazinone 7.5g Acetone 300ml Furthermore, using the same method as for the heat-developable light-sensitive material (XXI) except that exemplified compound (15) was removed, the heat-developable light-sensitive material (XXII) was prepared. Created.

The above samples were thermally developed for 5 seconds each at 120°C, 125°C, and 130°C using a heating roller after exposure according to the description in Example 1 to produce images, and the results shown in Table 7 below were obtained.

Table 7 (1) As shown in Table 7, images with controlled gaffle density were obtained by adding the compound of the present invention.

patent applicant Oriental Photo Industry Co., Ltd.

Claims (1)

[Scope of Claims] At least (a) an oxidation monoreduction image forming component comprising a long-chain fatty acid silver salt and a reducing agent, (b) a photosensitive silver halide or (and) a photosensitive silver halide forming component on a support. as well as(
c) In a heat-developable sensitive material in which a heat-developable photosensitive element comprising a binder is formed in a single layer or in multiple layers, the heat-developable photosensitive element contains (d) at least one compound represented by the following general formula. A heat-developable sensitive material characterized by: General formula: HOOC-R-COOH (In the formula, R represents a linear or branched alkylene group having 4 or more carbon atoms, or an alkenylene group.)