JPS6227373B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heat-developable photosensitive material, and more specifically, a heat-developable photosensitive material that significantly increases photosensitivity by containing a nitrogen-containing organic base having a conjugate acid pka of 0.5 to 10.0. This relates to photosensitive materials. The conventional photographic method using silver halide emulsions is
Although it is extremely superior in terms of sensitivity, gradation, and image quality,
The development and fixing processes are wet and time consuming, and there are various problems such as the use of hazardous chemicals in each process, which come in contact with workers' hands, and the need for wastewater treatment. Therefore, heat-developable photosensitive materials have been proposed that can easily form images by short-time dry processing without liquid processing, and various efforts have been made to date. The main image forming agent of this heat-developable photosensitive material is an organic silver salt oxidizing agent, and the material includes a type that can form an image by exposure and heat development (hereinafter, this type is referred to as a preactivated type); Both types (hereinafter referred to as post-activation type) that can form an image by preheating treatment, exposure to light, and thermal development have been proposed. The former pre-activation type is mainly composed of an organic silver salt oxidizing agent, a small amount of silver halide in catalytic contact with the reducing agent, and the latter post-activation type is pre-heated. Photosensitivity is imparted only when strained, and it remains non-photosensitive under room light until heat pretreatment is applied. However, all of these types of heat-developable photosensitive materials have the disadvantage of significantly lower photosensitivity than silver halide emulsions. For this reason, the current situation is that the use of this material as a general-purpose photosensitive material is limited. Therefore, as a result of extensive research in order to overcome the above-mentioned drawbacks, the present inventors used an organic haloamide as all or a part of the photosensitive silver halide forming component, and further developed a method in which the pka of the conjugate acid is 0.5 to 10.0. It has been found that by containing a nitrogen-containing organic base having a certain value, it is possible to obtain a heat-developable light-sensitive material that is extremely excellent in both sensitivity and stability of the green light-sensitive material. From the conventionally known facts, it is expected that the stability of the raw photosensitive material of the heat-developable photosensitive material is significantly deteriorated in the presence of a nitrogen-containing organic base. Therefore, the effect of the present invention, which is that the addition of a base can sensitize a raw material without impairing its stability, is completely unexpected from conventional common sense and is surprising. Presumably, the composition of the present invention is acidic in the absence of a base and coexists with an organic haloamide that has strong oxidizing power, so it is possible to achieve significant sensitization without sacrificing stability using a base. It is assumed that The present invention provides (a) an organic silver salt oxidizing agent, (b) an organic haloamide, (c) a reducing agent for silver ions, and (d) a pka of a conjugate acid.
is characterized by containing nitrogen-containing acid bases having a value of 0.5 to 10.0. Examples of the nitrogen-containing organic base as component (a) used in the present invention include pyridine, quinoline, isoquinoline, acridine, phenanthridine, pyridazine, pyrimidine, pyrazine, cinnoline, phthalazine, quinazoline, quinoxaline, phenazine, phenanthroline, and pteridine. , pyrazole, imidazole, benzimidazole and substituted products thereof. Examples of the substituent include, but are not limited to, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a nitro group, a halogen group, a nitrile group, an alkoxy group, a carboxyalkyl group, and the like. The pka of the conjugate acid of the organic base is
Derivatives between 0.5 and 10.0 are effective. N-alkylmorpholine, trialkylamine, etc. can also be used if the pka of the conjugate acid does not exceed 10.0. However, when acetidine has a high pka (pka 11.3), even if a small amount is used, the photosensitive material obtained is extremely unstable upon storage. On the other hand, with a substance having a small pka such as 2-fluoropyridine (pka...0.4), almost no sensitization is observed. Many of the above-mentioned nitrogen-containing organic bases that do not have acidic protons in the same molecule fall under this category. Furthermore, with bases that have acidic protons in the same molecule, sensitization is seen when the pka of the proton is greater than 12, such as benzimidazole and pyrazole; No significant sensitization is seen with small ones. In addition to these conditions, those that are stable against oxidation and acidic conditions are more preferred. Pyridine, quinoline, isoquinoline, quinazoline, phthalazine, quinoquinaline, pyrimidine, pyrazole, and derivatives thereof. Specific derivatives are listed below. 2-Chlorpyridine, 3-chlorpyridine, 2
-bromopyridine, 3-bromopyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2-isopropyridine, 2-t-
Butylpyridine, 3-phenylpyridine, 2.6
-di-t-butylpyridine, 3-acetylpyridine, β・β′-dipyridyl, γ・γ′-dipyridyl, 2-methylquinoline, 3-methylquinoline,
4-methylquinoline, 2-chloroquinoline, 4-
Chlorquinoline, 2-methoxyisoquinoline, 4
-methylpyrimidine, 2-dimethylaminopyrimidine, 2-methoxyquinazoline, 2-methylquinoxaline, 1-methylpyrazole, 2-methylpyrazole, and the like. The preferred amount of these used is in the range of 0.03 to 1 mol based on the silver salt oxidizing agent. pka values and measurement methods are available, for example, in Introduction to the Chemistry of Heterocycles (written by Adrien Albert, translated by Banji Nakanishi, Maruzen), Chemistry Handbook (Maruzen), and Acid-Base Equiribria (EJKing).
Pergamon Press, New York.1965). Next, the organic silver salt oxidizing agent of component (a) is extremely stable to light and reacts with the reducing agent when thermally developed to produce a silver image. Silver laurate, silver palmitate, silver stearate,
Examples include higher fatty acid silver such as silver arachinate and silver behenate, silver benztriazole, and silver saccharin. Among them, silver stearate, silver arachidate, and silver behenate are most preferred because they cause little fog during heat development. As the organic haloamide of component (b), for example, N-
Chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide, N-chlorophthalimide, N-bromophthalimide, N-iodophthalimide, N-bromoacetamide,
N-bromooxazolinone, N-chlorophthalazinone, N-bromophthalazinone, N-bromoacetanilide, N.N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, trichloroisocyanuric acid, 1 -chlorobenztriazole, etc., but are not limited to these examples. The amount used is suitably in the range of 0.001 mol to 0.2 mol based on the organic silver salt oxidizing agent. At least a portion of these organic haloamides are
Although photosensitive silver halide is formed during emulsion preparation or preheating, other sources of halide ions can also be used in conjunction with the organic haloamide as a silver halide forming component. Next, as the component (c), a reducing agent for silver ions, any of those commonly used in this field can be used, and inhibiting fufunols are particularly preferred. For example, α・α′−(3・5−
di-t-butyl-4-hydroxyphenyl) dimethyl ether, 2,6-bis(3'-t-butyl-
2'-Hydroxy-5'-methylbenzyl)-4-methylphenol, 2,2'-methylenebis(4,6
-di-t-butylphenol), 2,2'-methylenebis(6-t-butyl-4-ethylphenol), 2,2'-methylenebis(4,6-di-t-
butylphenol), bis(2-hydroxy-
Examples include 3,5-di-t-butylphenyl)methane. Other preferred examples include hydroquinone, 2,2'-dihydroxy-1,1'-binaphthyl, and methyl gallate. Two or more of the above reducing agents may be used in combination. The amount used is 0.1 to silver salt oxidizing agent.
A range of 3 moles is suitable. Next, in addition to the above-mentioned components, a toning agent, a thermal fog inhibitor, and an image stabilizer commonly used in this field may be included, if necessary. Examples of toning agents include phthalazinone, N-acylphthalazinone, N-carbamoyl phthalazinone, phthalimide, cyclic imides such as succinimide, cyclic hydrazides such as phthalic acid hydrazide and maleic acid hydrazide, benzoxazinedione, Preferred are quinazolinedione and the like. Also, effective antifogging agents include mercury salts such as mercury acetate, palladium compounds, benztriazole, thiouracil, sulfinic acid or its salts, and the like. Next, as an image stabilizer, tetrabromobutane, hexabromocyclohexane, α・α・
Examples include α'.α'tetrabromo O-xylene. The components and additives of the heat-developable photosensitive material described above can be used by being dispersed in various binders. As a binder, polyvinyl butyral, polyvinyl formal, polyvinylpyrrolidone, polystyrene, polymethyl methacrylate, polycarbonate, polyvinyl acetate, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, cellulose acetate butyrate, ethyl cellulose, cellulose acetate, Cellulose acetate butyrate, polyamide resin, polyvinyl alcohol, gelatin,
Examples include collodion. These can also be used in combination of two or more types. Further, the support to which the components and additives dispersed in the binder are coated is not particularly limited as long as it is stable against heating. For example, plastic films such as polyethylene terephthalate, polycarbonate, polyvinyl acetal, and cellulose ester, metal foils such as aluminum, glass, and various papers are suitable. Further, the above-mentioned components and additives are dispersed in the binder and applied onto the support. Further, each of the above-mentioned components and additives may be used by being dispersed in two or more layers and laminated. The sensitivity of the heat-developable photosensitive material having the above composition is increased by preheating treatment. The temperature of the preheating treatment is preferably 90° to 150°C, and the higher the heating temperature, the shorter the heating time. Heat development is done at 90℃~
It is carried out at 160°C, preferably in the range of 110°C to 135°C. As the heating method, a method normally used in this field can be used as appropriate. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto. Example 1 A silver behenate suspension was prepared by ball milling 4 parts of silver behenate and 20 parts of a methyl ethyl ketone:toluene mixture (2:1 weight ratio) for 24 hours. Using this suspension, prepare the following composition,
Coated on polyester film. Coating emulsion first layer Silver behenate suspension 12.0g Polyvinyl butyral 3.0g Methyl ethyl ketone 12.0g Mercury acetate 0.05g N-iodosuccinimide 0.12g Nitrogen-containing organic base Compound names, amounts added and pka are shown in Table 1. Second layer Cellulose acetate 1.2g Acetone 16.3g Phthalazinone 0.28g 2,2'-methylenebis(6-t-butyl-4-ethylphenol) 0.70g The addition of the first layer composition followed the above described order. . After the first layer was applied and dried, the second layer was applied. The resulting photosensitive film is insensitive to normal light, so it was preheated for 5 seconds at 100°C in the dark, then exposed to light for 1/8 second using a 500W xenon lamp, and heated to 130°C.
Developed for 1 second. Maximum optical density of the image obtained
ODmax and minimum optical density ODmin, as well as ODmax and ODmin of the image formed by the same image forming process as above after exposing the raw film to conditions of temperature 50℃ and 90% relative humidity for 24 hours, are expressed as the stability of the raw film. Shown in 1. The nitrogen-containing organic bases in Tables 1 to 4 below refer to photosensitive films containing the nitrogen-containing organic bases.

[Table] Example 2 Using the same weight of N-bromophthalazinone instead of N-iodosuccinimide in Example 1,
A photosensitive film was also prepared by repeating the same procedure except that the same weight of phthalimide was used instead of phthalazinone. This was evaluated in the same manner except that development was performed at 120° C. for 10 seconds. The results are shown in Table 2.

【table】

[Table] Example 3 Using the silver behenate emulsion of Example 1, the following composition was prepared and coated on a polyester film. First layer silver behenate suspension 12.0g Polyvinyl butyral 3.0g Methyl ethyl ketone 12.0g Mercury acetate 0.05g Diphenyltellurium dibromide 0.05g N-iodophthalimide 0.10g Nitrogen-containing organic base
The compound names and amounts added are shown in Table 2. 2nd layer Polymethyl methacrylate 1.2g Methyl ethyl ketone 16.3g Phthalazinone 0.28g 2,2'-methylenebis-(6-t-butyl-4-
Methylphenol) 0.70g The order of addition for the first layer was as described above. After the first layer was applied and dried, the second layer was applied. Since the obtained photosensitive film is insensitive to ordinary light, it was preheated in the dark at 110°C for 1 second, exposed to a 300W tungsten lamp for 1/60 second, and then developed at 120°C for 3 seconds. Maximum optical density ODmax and minimum optical density ODmin of the obtained image,
The raw film was exposed to conditions of a temperature of 60° C. and a relative humidity of 90% for 1 hour, and then an image was formed using the same image forming process as described above. The ODmax and ODmin of the raw film are shown in Table 3 as the stability of the raw film.

[Table] The pka of the acidic protons of benztriazole and tetrazole is 8.57 for the former and 4.9 for the latter. Example 4 A silver stearate suspension was prepared by replacing the silver behenate in Example 1 with the same weight of silver stearate, and using this, an emulsion with the following composition was prepared and coated on art paper. . Coating emulsion Silver stearate suspension 12.0g Polyvinyl butyral 3.0g Methyl ethyl ketone 12.0g N-bromosuccinimide 0.05g Mercury acetate 0.01g Maleic acid imide 0.5g Nitrogen-containing organic base Will be described later. 2,6bis(2'-hydroxy-3'-t-butyl-
5'-Methylbenzyl)-4-methylphenol
1.5g Additions followed the order described above. The obtained film was preheated for 5 seconds at 100° C. using a hot roll, exposed with a mask for 1/8 second using a 500 W tungsten lamp, and then developed by heating at 130° C. for 2 seconds using a hot roll. Those containing no nitrogen-containing organic base give only a barely perceptible yellow image, whereas those containing 0.1 g each of phthalazine, pyridine, quinoline, isoquinoline, quinazoline, and cinnoline give a clear black image. gave an image. The storage stability was also good. Comparative Example A film was prepared by repeating the same operations as in Example 1 except that 0.10 g of ammonium bromide was used in place of N-iodosuccinimide in Example 1. The obtained photosensitive film was exposed for 1/8 second using a 500W xenon lamp and developed for 1 second at 130°C.
The maximum optical density ODmax and minimum optical density ODmin of the obtained image and the OD of the image formed by the same image forming process as above after exposing the raw film to the conditions of temperature 50°C and relative humidity 90% for 24 hours
max and ODmin are shown in Table 4 as raw film stability.

[Table] As can be seen by comparing Example 1 and Comparative Examples, the raw film stability of the photosensitive film containing organic haloamide is significantly better than that of the film not containing organic haloamide.

Claims (1)

[Claims] 1 (a) Non-photosensitive organic silver salt oxidizing agent (b) Organic haloamide
(c) A reducing agent for silver ions and (d) A nitrogen-containing organic base that does not have an acidic proton in the same molecule and has a conjugate acid pKa of 0.5 to 10, or an acidic proton in the same molecule. and the pKa of its proton is greater than 12, and the pKa of the conjugate acid is
1. A heat-developable photosensitive material characterized by containing four components of nitrogen-containing organic bases having a value of 0.5 to 10. 2. The heat-developable photosensitive material according to claim 1, wherein the organic haloamide is an N-iodinated organic amide.