JPH037090B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a silver halide photographic material, and more particularly to a silver halide photographic material with improved sensitivity and fog. Increasing the sensitivity without reducing the quality of photographic images is a persistent and continuing desire of users of photographic materials. In response to this, several sensitization techniques have been developed in the photographic industry as a result of various studies. Among these, it is known that a thioether compound is used as a sensitizer in the production of silver halide emulsions as a highly effective and highly practical technique. For example, US Patent No. 2521926, US Patent No. 3021215,
Same No. 3038805, No. 3506443, No. 3057724, Same No.
No. 3062646, No. 3574709, No. 3622329, No.
No. 3,625,697 and other publications propose a technique for increasing the photographic sensitivity of an emulsion by making a thioether compound present during chemical ripening during emulsion production or immediately before coating. However, although these thioethers have very effective sensitizing properties, there are still many unresolved technical problems in their use in products as photographic materials. Among these, a major and fatal problem is the instability of the effect of adding thioether. That is, changes in the drying conditions of a coated emulsion containing a thioether, changes in additives in the emulsion,
In addition, changes in conditions such as the development method of the finished photosensitive material may cause a significant increase in fog, and even if the purpose of the sensitizing effect is achieved, the increased fog reduces the value of the product. Decrease. On the other hand, even if no fogging occurs, the sensitizing effect may disappear completely due to changes in various conditions such as those mentioned above. In order to suppress fog, measures such as refraining from chemical ripening or adding an antifoggant are taken, but this significantly impairs the sensitization and the use of thioether becomes meaningless. In addition, the optimum processing conditions must be developed and specified for each new product development to guarantee low fog density and high sensitivity through development processing conditions, which is not necessarily a great benefit for both users and manufacturers. do not have. An object of the present invention is to provide a silver halide photographic material in which sensitization by a thioether compound is stably and significantly improved. Specifically, it is an object of the present invention to provide a silver halide photographic material that can stably exhibit high sensitivity and low fog characteristics under general processing conditions. The object of the present invention is the following general formula [], [],
At least one thioether compound represented by [], [] and [], a cation selected from potassium ion, sodium ion, lithium ion and ammonium ion and chloride ion,
This is achieved by a silver halide photographic material containing at least 0.015 mol per mol of silver halide of at least one inorganic salt consisting of an anion selected from nitrate ions and thiocyanate ions. General formula [] S (-A-B-A'-S-R) In the formula ₂ , A is a lower alkylene group or (-
CH ₂ CH ₂ O) _o CH ₂ O- group, B is -NHCOO
- or -CONH- group, A' represents a lower alkylene group or (-CH ₂ CH ₂ O (- _o CH ₂ CH ₂ - group. R is a lower alkyl group, phenyl group, aralkyl group, -
Represents CH ₂ CH ₂ COOC ₂ H ₅ groups. n represents an integer from 1 to 30. General formula [] O (-A-B-A'-S-R) ₂ In the formula, A is -CH ₂ CH ₂ O- group, B is -CONH-
A' represents a lower alkylene group, and R represents a lower alkyl group. General formula [] R ¹ -N (-A-B-A'-S-R) In the formula ₂ , A is a lower alkylene group, B is -
Represents NHCONH− group, A′ is lower alkylene group,
R represents a lower alkyl group. R ¹ represents a lower alkyl group. General formula [] R ¹ (-A-B-A'-S-R) ₂ In the formula, A is

[Formula] or

[Formula] represents a group. B represents -NHCONH-, -NHCOO-, -OCONH- group. A′ is a lower alkylene group or

Represents [formula]. R represents a lower alkyl group, and R ¹ represents a linear or branched lower alkylene group. R ² , R ³ , and R ⁴ represent a hydrogen atom or a lower alkyl group, m represents 0 or 1, and n represents an integer of 1 to 10. General formula [] A (-S-R) ₂ In the formula, A is a lower alkylene group,

[Formula] -CH ₂ CH ₂ OCH ₂ CH ₂ - represents a group. R is

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

Represents [formula]. Typical specific examples of the compounds belonging to the above general formulas [], [], [], [] include the following compounds. Next, typical examples of compounds belonging to the general formula [] include the following compounds. There are no particular restrictions on the method of synthesizing the compound used in the present invention, and very common methods can be used. Synthesis methods described in publications such as No. 47-11116 and JP-A-54-155828 can be used. In the present invention, the substance used with the thioether is formed from a cation selected from K ⁺ , Na ⁺ , Li ⁺ and NH ₄ ⁺ and an anion selected from Cl ^- , NO ₃ ^- and SCN ^- . It is an inorganic salt. These inorganic salts alone have no sensitizing effect. However, it is a surprising fact that when used in combination with the above-mentioned thioether, a large sensitizing effect can be obtained with little fog. In addition, in the inorganic salt,
KNO ₃ , LiCl, and NH ₄ SCN are versatile and have stable effects, so they can be particularly preferably used. As cations, heavy metal ions and the like are generally toxic and should be avoided from the viewpoint of environmental health and pollution, and also have an adverse effect on the physical properties of gelatin and a significant effect on photographic performance, so that they cannot achieve the purpose of the present invention. In addition, polyvalent anions have a particularly adverse effect on the physical properties of gelatin, significantly impairing image quality. Organic salts have various unnecessary effects on photographic performance, such as suppressive effects, and do not meet the purpose of the present invention. General formulas used in the present invention [], [], [],
The compounds and inorganic salts represented by [] and [] are contained in the element layer on the side of the silver halide emulsion layer provided on the support among the element layers constituting the silver halide photographic light-sensitive material. The purpose of can be achieved. Among these constituent layers, it is most effective to contain it in the silver halide emulsion layer, but it may also be contained in a protective layer or a constituent layer adjacent to another silver halide emulsion layer. In order to contain the compound, it may be dissolved in water and added to the coating liquid for forming the component layer. The addition time may be at the time of coating or any time before coating, but if the layer to be contained is a silver halide emulsion layer, it is preferably added after chemical ripening and during coating. The amount added is according to the general formula [], [], [], [] and []
For the compound represented by , the amount is preferably in the range of 1.5 mg to 300 mg, and 10 mg to 10 mg per mole of silver halide.
More favorable results are obtained in the mg range. For inorganic salts, per mole of silver halide
The range of 0.015 mol to 0.15 mol is preferable, and more preferable results are obtained in the range of 0.02 mol to 0.08 mol. It goes without saying that the above-mentioned addition amount is appropriately selected depending on the type of silver halide, the layer to be added, the type of compound used, etc. General formulas used in the present invention [], [], [],
The compounds and inorganic salts represented by [ ] and [ ] may be mixed in advance and then added to the coating solution, or they may be added separately without any difference in effect. It may be added to different layers. In particular, more favorable results can be obtained by adding inorganic salts to the emulsion layer. Silver halide photographic materials to which the present invention can be applied include various types of silver halide photographic materials. For example, the present invention can be effectively applied to any arbitrary material such as general black and white photographic materials, X-ray photographic materials, color photographic materials, copying photographic materials, diffusion transfer photographic materials, silver dye bleaching photographic materials, etc. Although applicable, surface latent image type emulsions are particularly preferred. The silver halide used in these silver halide photographic light-sensitive materials includes silver bromide, silver chloride, silver chlorobromide, silver iodobromide, silver iodochlorobromide, etc., with various crystal habits and grain sizes depending on the purpose. are used. Among these, silver iodobromide is particularly preferred, and among these, highly sensitive emulsions containing 3 mol % or less of AgI and having an average grain size of 0.7 to 1.2 .mu.m are preferred. These photosensitive silver halide emulsions are obtained by suspending them in hydrophilic colloids by known methods.
In that case, the preparation may be carried out by any of the ammonia method, neutral method, or acid method, and any mixing method such as single jet method or double jet method may be used. Hydrophilic colloids to which the present invention is applied include proteins such as gelatin, albumin, and casein as binder components, cellulose derivatives such as hydroxyethyl cellulose and carboxymethyl cellulose, starch, and sugar derivatives such as agar, sodium alginate, and demistransulfur. et al.
Further, polyvinyl alcohol, poly-N-vinylpyrrolidone, polyacrylic acid derivatives, etc. may also be used. Particularly among these, new aqueous colloids consisting of gelatin are commonly used. Chemical sensitization methods such as noble metal sensitization, sulfur sensitization, and reduction sensitization can be applied to the silver halide emulsion used in the silver halide photographic light-sensitive material of the present invention. The feeling is most preferable. The silver halide photographic light-sensitive material of the present invention contains an ultraviolet absorber in the silver halide emulsion layer or its adjacent layer.
It cannot prevent the inclusion of image stabilizers, anti-staining agents, sequestering agents, etc. Known stabilizers such as azaindenes, thiazolium salts, and mercaptotetrazoles, and fog inhibitors can be used in the silver halide emulsion used in the silver halide photographic material of the present invention to improve storage stability. . The silver halide photographic light-sensitive material according to the present invention includes photographic hardeners in the coating solution such as aldehyde-based, aziridine-based, isoxazole-based, epoxy-based, vinylsulfone-based, acryloyl-based, carbodiimide-based, maleimide-based, acetylene-based, Compounds such as methanesulfonic acid esters and triazines may be used as appropriate. The component layer of the silver halide photographic light-sensitive material according to the present invention contains a coating aid such as a nonionic activator such as saponin or an anionic activator of sulfosuccinic acid type to facilitate coating of the layer. be able to. The silver halide emulsion used in the silver halide photographic light-sensitive material of the present invention can be spectrally sensitized with methine dyes and styryl dyes such as cyanine, merocyanine, hemicyanine, rhodacyanine, and oxonol. Further, if necessary, a fluorescent whitening agent or the like may be included, each of which is appropriately selected depending on the purpose of use of the silver halide photographic light-sensitive material. As mentioned above, the silver halide photographic light-sensitive material according to the present invention includes layers other than the silver halide emulsion layer such as a protective layer, an intermediate layer, a filter layer, an antihalation layer, an undercoat layer, an auxiliary layer, a backing layer, etc. These layers may have as supports baryta paper, polyethylene-coated paper, polypropylene synthetic paper, glass plates, cellulose acetate, cellulose nitrate, polyvinyl acetal, polypropylene, polyester films such as polyethylene terephthalate, polycarbonate. These supports include films, styrene films, etc., and these supports may be subjected to various treatments such as undercoating, corona discharge, glow discharge, flame treatment, etc. in order to strengthen the adhesion with the silver halide emulsion layer. Next, the developer used for developing the silver halide photographic light-sensitive material according to the present invention may be of a commonly used type. Examples of the developer include hydroquinone, N.methyl-p-aminophenol-1-
Phenyl-3-pyrazolidone, paraphenylenediamines, etc. may be used alone or in combination. or,
The developer contains alkaline agents such as sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium metaborate, alkanolamine, etc., and the preservatives include sodium sulfite, potassium sulfite, sodium bisulfite, potassium pyrosulfite, formaldehyde, Examples of development fog inhibitors such as tonalium hydrogen sulfite adducts include 5
-Nitrobenzimidazole, 5-methylbenzotriazole, 6-nitrobenzotriazole,
Azoles such as 1-phenyl-5-mercaptotetrazole can be used as appropriate. A hardening agent may be included in the developer. For example, among the aldehydes, dialdehyde compounds such as glutaraldehyde, maleic dialdehyde, and their bisulfites are effectively used. The present invention is particularly effective when processing with a developer containing glutaraldehyde salt as a high-temperature rapid developer for X-rays. In addition, the developer may contain an antioxidant, a chelating agent, a development accelerator, a pH adjuster, and the like. Development time is silver halide photographic material,
It may be selected appropriately depending on the developer, processing temperature, etc. The development process can be carried out using rapid automatic equipment using a vat type or roller transfer type, and the temperature is between 17℃ and 50℃.
The temperature in °C is selected depending on the purpose. Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereby. Example 1 A highly sensitive silver iodobromide emulsion for X-rays containing 2.3 mol% of silver iodide prepared by a conventional method was subjected to second ripening using a sulfur sensitizer and a gold sensitizer. This emulsion was divided into 100 g portions, the compound and inorganic salt according to the present invention were added, and ordinary stabilizers, hardeners,
After adding a coating aid, it was coated uniformly on both sides of a polyethylene phthalate film base and dried to prepare a sample. These samples were exposed through an aluminum wedge using the following exposure method. This was developed at 40°C for 30 seconds using a developer having the following composition. Developer composition Anhydrous sodium sulfite 70g Hydroquinone 10g Sodium carbonate monohydrate 20g 1-phenyl-3-pyrazolidone 0.35g Potassium hydroxide 5g 5-methylbenzotriazole 0.05g Potassium bromide 5g Glutaraldehyde bisulfite 15g Glacial acetic acid 8g Water Add it to 1. The relative sensitivities of the obtained samples when the fog was kept constant at a density of 0.03 were determined and are shown in Table 1. However, the relative sensitivity is expressed as 100 for a sample containing no compound. Exposure method: Using a polar light FX-ray intensifying screen (emission maximum 425.0nm, manufactured by Dainippon Toyo Co., Ltd.), tube voltage 60KVp tube current
X-ray irradiation for 0.5 seconds at 200mA. The amounts of the compounds shown in Table 1 are per mole of silver halide.

【table】

[Table] (The sensitivity is based on a constant Kabuno concentration of 0.03, and is expressed as a relative value when the sensitivity of sample No. 1 (no additives) is set as 100.) The above table - As is clear from Example 1, it is understood that a highly sensitized photographic material can be obtained by using the silver halide photographic emulsion according to the present invention. Example 2 The samples prepared and exposed as in Example 1 were subjected to the following two types of development, A and B, and the relative sensitivity and fog were determined for each sample and are shown in Table 2. However, the relative sensitivity is expressed as 100 for a sample developed in A and containing no compound according to the present invention. A: A sample was prepared by developing with a developer having the composition shown below at 20° C. for 4 minutes and 30 seconds, fixing in the usual manner, and washing with water. Developer composition N-methyl-p-aminophenol sulfate
3.0g Anhydrous sodium sulfite 50.0g Hydroquinone 6.0g Soda carbonate 29.5g Potassium bromide 1.0g Add water to make 1. B: After developing at 35° C. for 30 seconds with XD-90 developer for automatic processors (manufactured by Konishiroku Photo Industry Co., Ltd.), the sample was fixed, washed with water, and dried in a conventional manner. The results obtained are shown in Table-2.

【table】

[Table] As is clear from Table 2 above, the present invention can provide a silver halide photographic material that is highly sensitized without being affected by changes in development conditions and has less fog. mg in parentheses
is the amount added per mole of silver halide. Example 3 Samples prepared and coated as in Example 1 were tested by first blowing cold air and then blowing hot air 2 as shown in Table 3 below.
After drying under different drying conditions C and D, exposure and development were carried out in the same manner as shown in Example 1, and the relative sensitivity and fog of the obtained samples were determined and are shown in Table 4. Note that the relative sensitivity is expressed as 100 for a sample under drying condition C and containing no compound according to the present invention.

【table】

[Table] (mg is the amount added per mole of silver halide)
As is clear from Table 4 above, by using the compound according to the present invention, it is possible to provide a silver halide photographic material that is highly sensitized regardless of drying conditions and has less fog.

Claims (1)

[Claims] 1. At least one of the thioether compounds represented by the following general formulas [], [], [], [] and [], potassium ion, sodium ion,
A halogen containing 0.015 mol or more per mol of silver halide of at least one kind of inorganic salt consisting of a cation selected from lithium ion and ammonium ion and an anion selected from chloride ion, nitrate ion and thiocyanate ion. Silver chemical photographic material. General formula [] S (-A-B-A'-S-R) In the formula ₂ , A is a lower alkylene group or (-
CH ₂ CH ₂ O) _o CH ₂ O- group, B is -NHCOO
- or -CONH- group, and A' represents _a lower alkylene group _or ( _-CH2CH2O ) _{-oCH2CH2- group} . R is a lower alkyl group, phenyl group, aralkyl group, -
Represents CH ₂ CH ₂ COOC ₂ H ₅ groups. n represents an integer from 1 to 30. General formula [] O (-A-B-A'-S-R) ₂ In the formula, A is -CH ₂ CH ₂ O- group, B is -CONH-
A' represents a lower alkylene group, and R represents a lower alkyl group. General formula [] R ¹ -N (-A-B-A'-S-R) In the formula ₂ , A is a lower alkylene group, B is -
Represents NHCONH− group, A′ is lower alkylene group,
R represents a lower alkyl group. R ¹ represents a lower alkyl group. General formula [] R ¹ (-A-B-A'-S-R) ₂ In the formula, A represents [Formula] or [Formula] group. B represents -NHCONH-, -NHCOO-, -OCONH- group. A′ represents a lower alkylene group or [Formula]. R represents a lower alkyl group, and R ¹ represents a linear or branched lower alkylene group. R ² , R ³ , and R ⁴ represent a hydrogen atom or a lower alkyl group, m represents 0 or 1, and n represents an integer of 1 to 10. General formula [] A (-S-R) ₂ In the formula, A is a lower alkylene group,
[Formula] -CH ₂ CH ₂ OCH ₂ CH ₂ - represents a group. R represents a [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] group.