JPS648810B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heat-developable photosensitive material, and in particular, by containing an aliphatic dicarboxylic acid having 4 or more carbon atoms, thermal fog caused by development is significantly reduced without causing any change in image characteristics such as a decrease in photosensitivity. This invention relates to a heat-developable photosensitive material. The conventionally used silver halide photography method is superior to other photographic methods in terms of photosensitivity, gradation, etc., but because the processing steps such as fixing and bleaching are wet. , its handling is complicated, and there are many disadvantages in mechanizing the treatment process. 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 photosensitive material in which heat treatment is performed in the developing step has been proposed as a method that is particularly superior to conventional image forming methods. For example, Japanese Patent Publication No. 4924/1983 describes a heat-developable photosensitive material comprising silver halide in catalytic contact with an organic silver salt and an organic silver ion. Also, as something similar to this, there is
It is described in Publication No. 26582 and Japanese Unexamined Patent Publication No. 46-6074. In addition to the above, there are also heat-developable photosensitive materials which 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 photosensitive material consists of a heat-developable photosensitive element that does not contain silver halide or has no photosensitivity even if it contains silver halide. - Described in Japanese Patent Publication No. 29819, Japanese Patent Publication No. 53-41967, and Japanese Patent Publication No. 54-5687. Heat-developable photosensitive materials have the advantage of not requiring a wet process for image formation, but on the other hand, image characteristics such as sensitivity and fog density are still not as satisfactory as compared to conventionally used silver halide photography. I can't say that. In particular, thermal fogging is likely to occur in unexposed areas (background areas) during thermal development, and latitude with respect to development temperature and development time is a major practical problem. Various methods have been proposed to improve the drawback of increased heat fog. Tokuko Showa 47-11113
The publication proposes the inclusion of a mercury compound as a heat fog preventive agent. This method shows excellent heat fog prevention properties, but as is well known, it is unfavorable from a toxicological point of view.
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, Tokukai Akira
No. 51-54428 proposes the combined use of sulfinic acids and phthalic acids, but such a method is undesirable because it has the disadvantage of coloring when exposed to light after image formation. In addition, 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 Methods using various compounds such as thiosulfonic acids or benzoic acids as disclosed in JP-A-53-125015 have been proposed, but none of them provide a superior antifogging effect compared to mercury compounds, which are unfavorable from a toxicological point of view. I couldn't do it. Therefore, an object of the present invention is to provide a heat-developable photosensitive material that significantly suppresses heat 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. The goal is to provide the following. The object of the present invention is to provide at least (a) an oxidation-reduction image forming component comprising a long-chain fatty acid silver salt and a reducing agent and (b) a photosensitive silver halide or (and) a photosensitive silver halide formation on a support. This can be achieved by containing (d) at least one compound represented by the following general formula in a heat-developable photosensitive element formed in a single layer or in multiple layers consisting of a component and (c) a binder. I can do it. 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 ability is due to desensitization and deterioration of stability over time. This was surprising to the present inventors, considering the fact that this method does not cause any damage. 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, unlike the aliphatic dicarboxylic acids of the present invention, aliphatic monocarboxylic acids do not exhibit antifogging effects.
Furthermore, among the aliphatic monocarboxylic acids, fatty acids identical to or close to the long-chain fatty acid silver salt used in the present invention,
For example, behenic acid, stearic acid, and the like are effective in improving image tone and stability after image formation, but are not effective in preventing fogging. Special Public Service 1977
- In Publication No. 12700, when silver benzotriazole is used as a reducible silver salt, from 9 carbon atoms
Organic acids such as saturated aliphatic monocarboxylic acids having up to 26 carbon atoms, aliphatic dicarboxylic acids having 4 to 10 carbon atoms, and hydroxyl-substituted benzoic acids, and their salts are used as heat development accelerators. The difference in the effect of adding aliphatic dicarboxylic acid between the invention and the present invention is not clear, but if I had to state it, it is due to the difference in reducibility between benzotriazole silver and long-chain fatty acid silver as reducible organic silver salts. it is conceivable that. Next, specific examples of the compounds constituting the present invention will be shown, but the invention is not limited thereto. (1) HOOC(CH ₂ ) ₄ COOH (2) HOOC(CH ₂ ) ₅ COOH (3) (4) HOOC(CH ₂ ) ₆ COOH (5) HOOC(CH ₂ ) ₇ COOH (6) (7) (8) HOOC(CH ₂ ) ₈ COOH (9) HOOC―CH＝CH―(CH ₂ ) ₆ COOH (10) HOOC(CH ₂ ) ₉ COOH (11) (12) (13) HOOC(CH ₂ ) ₁₀ COOH (14) HOOC―CH＝CH―(CH ₂ ) ₈ COOH (15) (16) HOOC (CH ₂ ) ₁₁ COOH (17) (18) (19) HOOC (CH ₂ ) ₁₂ COOH (20) (twenty one) (22) HOOC(CH ₂ ) ₁₃ COOH (23) (24) HOOC(CH ₂ ) ₁₄ COOH (25) HOOC(CH ₂ ) ₁₅ COOH (26) (27) HOOC(CH ₂ ) ₁₆ COOH (28) HOOC(CH ₂ ) ₁₇ COOH (29) HOOC(CH ₂ ) ₁₈ COOH (30) HOOC(CH ₂ ) ₂₀ COOH (31) HOOC(CH ₂ ) ₂₀ COOH (32) HOOC(CH ₂ ) ₂₁ COOH (33) HOOC(CH ₂ ) ₂₂ COOH (34) HOOC(CH ₂ ) ₂₃ COOH (35) HOOC(CH ₂ ) ₂₄ COOH (36) HOOC(CH ₂ ) ₂₈ COOH (37) HOOC(CH ₂ ) ₃₂ COOH The method and timing of addition of the compound of the present invention are not particularly limited, and for example, the compound may be directly added to a coating solution for a heat-developable photosensitive material in a state dissolved in an appropriate solvent. method, a method in which the compound is added to a layer adjacent to the heat-developable photosensitive material layer, or a method in which a heat-developable photosensitive material coating solution is applied onto a support and, after drying, the surface is immersed in a solution containing the compound of the present invention. etc. can be adopted. The preferred addition amount range of the compound of the present invention is 0.001 per mole of reducible organic silver salt.
The amount ranges from mol to 4 mol, particularly preferably from 0.1 mol to 2 mol. Further, addition of more than necessary is not preferable as it leads to a decrease in the maximum concentration. Further, in the general formula of the present invention, a compound in which R has 3 or less carbon atoms, such as succinic acid, exhibits the effect of suppressing fog density, but at the same time causes a decrease in maximum density, and furthermore, after image formation, it is significantly affected by indoor light. It has the disadvantage of being colored.
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) 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 reducing agent in separate layers or on top of the single layer. Alternatively, a multilayer structure may be provided 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 may be used in the oxidation-reduction image forming component. Developers generally used for ordinary silver halide photosensitive materials,
Specifically, hydroquinone, methylhydroquinone, chlorohydroquinone, methylhydroxynaphthalene, N,N'-diethyl-P-phenylenediamine, aminophenol, ascorbic acid,
Examples include 1-phenyl-3-pyrazolidone, and in addition to these, 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 4,4'-butylidenebis(6-tert-butyl) -3-methylphenol), 4,4'-thiobis(6-tertiarybutyl-3-methylphenol), etc., as well as bisnaphthol-based reducing compounds described in JP-A-46-6074, or Belgian patents. Examples include 4-benzenesulfonamidophenol compounds described in 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 to impart photosensitivity. There is a need. This silver halide is
Particularly fine particles are effective, and as a method for preparing them, part of the reducible organic silver salt is mixed with silver halide forming components such as ammonium bromide, lithium bromide, sodium chloride, N-bromosuccinimide. , etc. to prepare fine silver halide. Furthermore, a method of incorporating so-called extra-system silver halide can also be used. A heat-developable photosensitive element containing this extra-system silver halide is described, for example, in Belgian Patent No. 774,436. That is, the heat-developable photosensitive element is prepared by preparing the photosensitive silver halide outside of the oxidation-reduction imaging component and then adding and mixing the photosensitive silver halide to the imaging component. Silver halide (or silver halide forming component)
The suitable content is preferably 0.001 mol to 0.03 mol, more preferably 0.01 mol per mol of reducible organic silver salt.
moles to 0.15 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, polyvinylpyrrolidone, ethyl cellulose, cellulose acetate, polyvinyl acetate, polyvinyl alcohol, gelatin, and the sulfobetaine repeating unit described in Canadian Patent No. 774054. Examples include those having the following. The amount of the binder to be used is preferably 10:1 to 1:10, more preferably 4:1 to 1:2, based on the weight ratio of the reducible organic silver salt. Furthermore, in the heat-developable photosensitive material of the present invention, it is preferable to use an organic acid in order to improve the tonal properties of images and the stability after image formation. Alternatively, it is desirable to contain them in combination. The amount of these fatty acids used is 25 mol% to 200% of the reducible organic silver salt.
It is preferably 30 mol% to 120 mol%. Moreover, a suitable color toning agent can be contained. Color toning agents for this purpose include phthalazinone or its derivatives as described in U.S. Pat. phthalazinedione compounds, etc. 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. Thermal fog inhibitors used in combination include mercury compounds described in Japanese Patent Publication No. 47-11113, 1,2,4-triazole compounds described in Japanese Patent Publication No. 55-42375, and
Examples include tetrazole compounds described in Japanese Patent Application No. 55-105270, benzoic acids described in Japanese Patent Application No. 56-23512, and compounds having a sulfonylthio group described in Japanese Patent Application No. 56-33483. In particular, when the mercury compound described in Japanese Patent Publication No. 47-11113 is used in combination, an excellent antifogging effect that cannot be obtained when the mercury compound is used alone can be obtained. In other words, the antifogging effect of a mercury compound alone is proportional to the amount added, and if the amount necessary to obtain a sufficient antifogging effect is added, there will be a decrease in sensitivity at the time and a deterioration in sensitivity during storage of raw photosensitive materials. With disadvantages such as. Addition of a very small amount does not provide sufficient antifogging effect. However, when a trace amount of a mercury compound is used in combination with the compound of the present invention, an excellent antifogging effect can be obtained without such inconvenient decisions. The heat-developable photosensitive element of the present invention further includes a development accelerator, a curing agent, an antistatic agent (layer), an ultraviolet absorber,
It may contain a fluorescent brightener, a filter dye (layer), etc. Elements according to the invention may contain suitable spectral sensitizers. Useful sensitizing dyes include cyanine dyes, merocyanine dyes, xanthene dyes, especially "Product Licensing Index"
Vol. 1.92, pages 107-110 (published December 1971) or Belgian Patent No. 772371 are 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 papers such as baryta paper for photographs. Alternatively, metal plates (foils) such as aluminum, synthetic resin films or glass plates having a metal vapor-deposited film by a conventional method can be used. The present invention will be described below with reference 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, 200 ml of xylene, and 200 ml of n-butanol using a homomixer. 10 g of polyvinyl butyral was added to this dispersion, stirred and dissolved, and heated to 65°C.
Next, 1.0 g of N-bromosuccinimide dissolved in 25 ml of acetone was added and stirred for 2 hours. next,
Add 20g of behenic acid and dissolve with stirring, then add 30g of the dispersion.
The temperature was adjusted to 0.degree. C., and the following components were sequentially added while stirring to obtain a first coating solution. 1 2,2'-methylenebis(6-t-butyl-4
- 8% by weight of methylphenol) and 20% by weight of polyvinyl butyral in xylene/n-butanol (1/1 by volume) solution 250ml 2 Exemplary compound (13) 6g 3 3-Ethyl-5 [(3-methyl-2 -Thiazolylidene) ethylidene] rhodanine DMF 0.1
% solution 10 ml This first coating solution was applied onto photographic base paper using a roll coater. At this time, the amount of application when drying is
It was 11.5g/ ^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 2.5 g/m ² , and heat-developable sensitivity was obtained. Optical materials () were prepared. Second coating liquid Phthalazinone 25g Cellulose acetate 50g Acetone 1000ml A heat-developable photosensitive material () was prepared in the same manner as the heat-developable photosensitive material () except that exemplified compound (13) was omitted. In addition, 6 g of exemplified compound (13)
A heat-developable photosensitive material (20g) was prepared.
Furthermore, the amount of Exemplified Compound (13) was increased to 60 g to prepare a heat-developable photosensitive material (2). The above samples were exposed to light at 400 lux for 10 seconds using a light wedge (Kodak Step Tablet No. 2) using a 150W tungsten lamp for enlarging as the light source, and heated to 120℃, 125℃ using a heating roller.
Heat development was performed at 130°C, 135°C, 140°C, and 145°C for 5 seconds each to create an image. The maximum density, 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.) Heat-developable photosensitive material () The sensitivity at 130°C is expressed as 100.

[Table] As is clear from Table 1, the heat-developable photosensitive material () using the compound (13) of the present invention exhibits remarkable fogging suppression compared to the heat-developable photosensitive material () excluding the compound (13). Show your gender. In addition, as shown in heat-developable photosensitive materials () and (), exemplified compounds (13)
An increase in the amount of addition was accompanied by a decrease in maximum density, but there was no decrease in sensitivity, and fog suppression was exhibited up to a higher temperature development range. Example 2 4.2 g of Exemplified Compound (2) was used instead of Exemplified Compound (13) in the heat-developable photosensitive material () of Example 1, and 4.9 g of Exemplified Compound (5) was used to heat-develop the photosensitive material (). Developable photosensitive material (), 5.3 g of exemplified compound (9)
A heat-developable photosensitive material () was prepared using 6.7 g of Exemplified Compound (19), and exposed as described in Example 1. Thermal development was performed at ℃ for 5 seconds each, and the results shown in Table 2 below were obtained. still,
As a comparative example, the heat-developable photosensitive material of Example 1 ()
was used as a comparison.

【table】

[Table] As is clear from Table 2, by using the compound of the present invention, it was possible to obtain a heat-developable photosensitive material in which the fog density was significantly suppressed. Example 3 In the description of Example 1, 5.2 g of lauric acid was added instead of exemplified compound (13) to prepare a heat-developable photosensitive material ().
Add 52g of lauric acid to make a heat-developable photosensitive material (XI), add 3.2g of benzoic acid to make a heat-developable photosensitive material (XI), add 0.43g of phthalic acid to make a heat-developable photosensitive material (XII), Add 4.3g of heat-developable photosensitive material (), add 0.025g of thiouracil to add heat-developable photosensitive material (), and 0.25g of thiouracil.
Add heat-developable photosensitive material (X) to succinic acid.
3.0g of heat-developable photosensitive material () was prepared, exposed as described in Example 1, and developed with a heating roller at 125°C, 130°C, and 135°C for 5 seconds each to form an image. The image characteristics were compared with that of the heat-developable photosensitive material (2) described in Example 1, and the results shown in Table 3 were obtained.

[Table] As shown in Table 3, heat-developable photosensitive materials using lauric acid instead of exemplified compound (13) ()
and (), and the heat-developable photosensitive material (XI) using benzoic acid did not show any anti-fogging effect, but on the contrary showed an effect of accelerating development. In addition, heat-developable photosensitive materials (XII) and () using phthalic acid, and heat-developable photosensitive materials (XII) and Ta. Furthermore, as the amount added increased, the antifogging properties increased, but there was a tendency for further desensitization to occur. Further, the heat-developable photosensitive material (2) using succinic acid exhibited a fog suppressing effect, but was accompanied by a decrease in maximum density. In addition, after forming images on the heat-developable photosensitive materials () and () to (X), they were exposed to room light (white fluorescent lamp 3000 lux) for 120 hours and the degree of coloring of non-image areas due to light was observed. .
While the heat-developable photosensitive material () of the present invention showed almost no photodiscoloration, all of the other photosensitive materials used for comparison changed color to pink, especially the heat-developable photosensitive materials (), (), and () showed strong photodiscoloration. Example 4 In place of Exemplified Compound (13) in the heat-developable photosensitive material () of Example 1, 200 mg of mercuric acetate was added, and the heat-developable photo-sensitive material () was heat developed by adding 2 mg of mercuric acetate. 2 mg of mercuric acetate and 4.9 g of Exemplary Compound (5) were added to the heat-developable photosensitive material (2), respectively, to prepare a heat-developable photosensitive material (2). ，
Heat development was performed at 130°C, 140°C, 150°C, and 160°C for 5 seconds each, and the results shown in Table 4 below were obtained. In addition, each sample was stored for 5 days at a temperature of 35°C and a relative humidity of 80%, and then subjected to heat development for 5 seconds at 130°C and 150°C after exposure using the same method.
The results shown are obtained.

【table】

[Table] As shown in Tables 4 and 5, mercury compounds have the effect of suppressing fog caused by heat development depending on the amount added, but especially when the amount added is large, there is significant desensitization over time. It was found that this was accompanied by Furthermore, as seen in the heat-developable photosensitive material (), the compound of the present invention synergistically enhances the heat fog suppressing effect when used in combination with a small amount of mercury compound, and its effect is maintained over a wide developing temperature range. show. 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 325
ml and 325 ml of n-butanol were dispersed using a homomixer to prepare a dispersion. 40 g of polyvinyl butyral was added to this dispersion and dissolved with stirring.
Thereafter, the temperature was adjusted to 50°C, 0.25 g of lithium bromide dissolved in 50 ml of methanol was added, and stirring was continued for 2 hours. After that, adjust the temperature to 30℃ and continue stirring to add 2,2-methylenebis(6-t-butyl-4-methylphenol).
and 3-ethyl-5-[(3-methyl-2
-Thiazolylidene) ethylidene] rhodanine
10 ml of a 0.1% solution of DMF was added to form a first coating solution.
This first coating liquid was applied onto photographic base paper using a roll coater. At this time, the application amount when dry is 9.0
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 2.8 g/m ² to form a heat-developable photosensitive material. Materials () were prepared. Second coating liquid Phthalazinone 25g Cellulose acetate 50g Exemplified compound (8) 18g Acetone 1000ml The heat-developable photosensitive material () was prepared in the same manner as the heat-developable photosensitive material () except that Exemplified compound (8) was removed. 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 form images, and the results shown in Table 6 were obtained.

[Table] As shown in Table 6, images with extremely suppressed fog density were obtained by adding the compound of the present invention. Example 6 3.9 g of silver stearate was added to 100 ml of isopropyl alcohol and dispersed using a homomixer.
To this dispersion, 3 g of polyvinyl butyral was added and dissolved with stirring to prepare a polymer suspension dispersion of silver salt.
This dispersion was heated to 50°C under red safety light.
0.9 lithium bromide dissolved in 30 ml of acetone under stirring
g was added dropwise over 1 hour. 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 placed in a dispersion solvent consisting of 44 ml of xylene and 44 ml of n-butanol, and dispersed using a homomixer. Furthermore, 80 g of polyvinyl butyral was added as a binder and dissolved with stirring to obtain a silver salt polymer dispersion. Prepared. 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 solution. 2,2'-methylenebis(6-t-butyl-4-
methylphenol) 4g and xylene 5ml and n
-A solution consisting of 5 ml of butanol 1-Carboxymethyl-5-[(3-ethylnaphtho[1,2-d]oxazoline-2-ylidene)-ethylidene]-3-allyl-thiohydantoin 0.0013 g Exemplary compound (15) 0.12 g This first coating liquid was applied onto photographic base paper using a roll coater. At this time, the amount of application when dry is 10
g/ ^m2 . Next, on the coating formed by applying the first coating liquid, a second coating consisting of the following components is applied.
The coating solution was applied in layers so that the dry coating amount was 1.5 g/m ² to prepare a heat-developable photosensitive material (XI). Second coating liquid Cellulose acetate 15.0g Phthalazinone 7.5g Acetone 300ml A heat-developable photosensitive material (XII) was prepared using the same method as the heat-developable photosensitive material (XI) except that exemplified compound (15) was further removed. . 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] As shown in Table 7, images with suppressed fog density were obtained by adding the compound of the present invention.

Claims (1)

[Scope of Claims] 1. At least (a) an oxidation-reduction image forming component comprising a long-chain fatty acid silver salt and a reducing agent, (b) photosensitive silver halide or (and) photosensitive silver halide formation on a support. In a heat-developable photosensitive material in which a heat-developable photosensitive element consisting of a component and (c) a binder is formed in a single layer or in multiple layers, the heat-developable photosensitive element comprises (d) at least one compound represented by the following general formula. A heat-developable photosensitive material characterized by containing. General formula HOOC-R-COOH (R in the formula represents an alkylene group having 4 or more carbon atoms that may be linear or branched, or an alkenylene group.)