JP2000352785A - Silver halide photo-graphic sensitive material and its processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silver halide photographic sensitive material low in fog and superior in reproducibility of gradation and its processing method high in processing stability at the time of low replenishing. SOLUTION: This photosensitive material has at least one photosensitive silver halide emulsion layer on a support and the layer has a silver halide content of >=50 mol% of the total silver halides and these silver halide grains contain a rhodium compound in an amount of 10-9-10-7 mol/mol of silver and the inclination of an optical density does not exceed 3 in all the characteristic curve obtained with respect to the logarithm of its exposure amount at the time of exposing it to laser beams, and the photosensitive material is processed in the conditions in which a developing solution is replenished in an amount of <=200 ml/m2 and a bromide concentration in the developing solution is kept in <10 g/l in terms of KBr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide photographic light-sensitive material and a processing method therefor, and more particularly to a silver halide photographic light-sensitive material used for a laser imager in medical imaging and a processing method therefor.

[0002]

2. Description of the Related Art In recent years, in the medical field, in order to obtain a hard copy of an output image of a diagnostic apparatus such as X-ray CT and MRI, a method of obtaining a transmission photographic image by laser scanning exposure corresponding to an output signal from each modality. The number of such laser imagers installed has been increasing steadily. For the purpose of image diagnosis, it is required to have a particularly excellent image quality such as resolution and gradation as compared with ordinary ornamental images. Therefore, even today, wet-processed silver halide photosensitive materials are widely used. I have. In order to obtain a stable image by wet processing, usually, an automatic developing machine with constant temperature and processing time is used, and replenishment reflecting the processing amount and / or time is performed to stabilize the composition of the developing solution and process. The method is adopted.

[0003] However, while it is known that bromide ions in a developing solution act in a suppressive manner on development, the above-mentioned method accumulates in accordance with the processing. The only option is to reduce the amount of release from the film. On the other hand, medical images have a large amount of blackened parts, so they emit more bromide than when processing ordinary black-and-white photographic light-sensitive materials, and do not take measures to suppress the bromide ion level of the developer by increasing the replenishment amount. Did not get. Therefore, in terms of environmental protection and running costs,
There has been a strong need for a system that can process stably with a small amount of replenishment.

[0004] Increasing the proportion of chloride in the halide composition of a silver halide photographic light-sensitive material is an effective means for reducing the release of bromide ions into a developing solution. Since it is easy to cause fogging and softening, it is difficult to obtain a desired sensitivity and a required sensitivity. In particular, it is known that an iridium compound is contained in silver halide grains for the purpose of increasing the sensitivity to short-time high-illumination exposure such as laser exposure.However, the incorporation of a rhodium compound reduces the sensitivity and increases the contrast. It was prone to cause and was not commonly done.

[0005]

An object of the present invention to solve the above problems is to provide a silver halide photographic light-sensitive material having a high chloride ratio, low fog and excellent gradation reproducibility. Another object of the present invention is to provide a processing method having high processing stability even at the time of low replenishment.

[0006]

An object of the present invention is to provide a support having at least one light-sensitive silver halide emulsion layer on at least one surface thereof, and wherein the total halide composition of the emulsion layer is chloride. Is 50 mol% or more and chloride
When the silver halide emulsion grains containing at least 10 mol% contain 10 ^-9 to 10 ^-7 mol of a rhodium compound per mol of silver halide and are exposed to laser light, the optical density is expressed as a logarithm of the exposure amount. A silver halide photographic light-sensitive material characterized in that the inclination thereof does not exceed 3 over the entire characteristic curve obtained, and a replenishment rate of the silver halide photographic light-sensitive material of 200 ml / m ² or less, and The problem was solved by processing under the condition that the bromide concentration in the developer was kept at less than 10 g / liter in terms of potassium bromide.

The silver halide emulsion used in the silver halide photographic light-sensitive material of the present invention is characterized in that chloride is at least 50 mol% in the total halide composition of the photosensitive silver halide emulsion layer. More than one kind of silver halide emulsion grains may be present. In this case, chloride must be 50%
Although the above grains are present, the other silver halide grains can have any halide composition as long as the chloride content is 50 mol% or more in the total halide composition. As the proportion of chloride ions increases, the sensitivity generally decreases, and to compensate for this, it is possible to take measures to increase the particle diameter. 50 in the chloride composition
More preferably, it is not less than mol% and not more than 70%.

In the present invention, one kind of silver halide grains may have localized phases having different halide compositions. When it contains iodide, its content is at most 3 mol%, more preferably at most 1 mol%. The iodide may be present uniformly in the particles, or may be localized inside or on the surface of the particles. The shape of the silver halide grains may be irregular or plate-like in addition to regular crystals such as cubic and octahedral.

For the grain formation of the silver halide emulsion used in the present invention, methods known in the art such as forward mixing, reverse mixing, simultaneous mixing and the like are used. Among them, the so-called controlled double jet method, which is one of the simultaneous mixing methods and maintains pAg in a liquid phase in which particles are formed, is preferably used in order to obtain desired sensitivity and contrast with good reproducibility.
In this case, each particle has a coefficient of variation represented by {(standard deviation of particle diameter) / (average particle diameter)} × 100 of 15% or less, more preferably 10% or less.

The particle size of the silver halide emulsion grains used in the present invention can be freely selected as long as the object of the present invention is achieved. Any number of two or more kinds of silver halide grains may be mixed. However, as long as the desired gradation can be obtained, it is preferable that the number of silver halide grains is as small as possible without complicating the process. There are many. In this case, the particles having a small particle size covering the low sensitivity region preferably have a sphere equivalent diameter of 0.35 μm or less in consideration of covering power.

Among the silver halide emulsion grains used in the present invention, grains having a chloride content of 50 mol% or more always contain 10 ^-9 to 10 ^-7 mol of a rhodium compound per mol of silver halide. . The specific content varies depending on the properties of the emulsion grains and is empirically determined. However, if the content is more than this range, the desired sensitivity cannot be obtained, the contrast becomes too high, and conversely, the content becomes too small. Otherwise, fogging or softening is caused.

The silver halide emulsion grains used in the present invention are preferably doped with iridium ions in order to have high sensitivity in high-intensity short-time exposure to laser light. In general, the doping amount is preferably 10 ^-8 to 10 ^-5 mol per mol of silver halide. Further, for various purposes, cadmium salts, lead salts, zinc salts, thallium salts, iron salts and complex salts thereof can be contained.

The silver halide emulsion used in the present invention is:
It is preferable to sensitize with various chemical sensitizers.
search Disclosure Item 308119 Section III-A (December 1989
As described in the literature cited in p. 993), methods commonly used in the art such as sulfur sensitization, selenium sensitization, and noble metal sensitization can be used alone or in combination. In order to optimally perform the chemical sensitization, a thiocyan compound, a thioether compound, an azaindene compound, a thiosulfonic acid compound, or the like may be present.

The silver halide light-sensitive material of the present invention must have its slope (gamma value) not exceeding 3 over the entire characteristic curve in order to provide the density gradation required for diagnosis. In order to satisfy this condition in standard processing, the contrast of the silver halide light-sensitive material of the present invention can be adjusted by the type of emulsion grains used, dope of emulsion grains, chemical sensitization, organic additives and the like. .

Since the silver halide photographic light-sensitive material of the present invention is given high illuminance and short-time scanning exposure by laser light, it must be appropriately spectrally sensitized in order to have spectral sensitivity to the laser light. is there. Today, red or infrared lasers are inexpensive, so generally 600n
Spectral sensitized to wavelengths above m. The sensitizing dye used for this spectral sensitization includes Research Disclosure Item 18716
(November 1979, p.647) Item 308119 IV-A (Jan. 1989)
It is described in the literature described or cited in February p.993). In particular, cyanine dyes, merocyanine dyes, and complex merocyanine dyes are useful, and these dyes may be used alone, but are often used in combination.

Further, in the silver halide photographic light-sensitive material of the present invention, known photographic additives can be used for various purposes. These are the Research Disclosure Item
18716 (November 1979) and 308119 (December 1989), or in the references cited.

As the hydrophilic binder used in the silver halide photographic light-sensitive material of the present invention, gelatin is preferably used. If necessary, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, dextran, polyvinyl alcohol and polyvinyl Various kinds of synthetic hydrophilic binders such as pyrrolidone, polyacrylic acid, and polyacrylamide can be used.

Further, a dispersion of a polymer latex may be added to the hydrophilic colloid layer of the silver halide photographic light-sensitive material of the present invention for the purpose of improving pressure resistance and improving adhesion to a support. Polymers include acrylate homopolymers, acrylate / acrylic acid copolymers,
Typical examples include styrene / butadiene copolymers.

As the support which can be used as the silver halide light-sensitive material of the present invention, any support known in the art can be used, and in particular, polyester films such as cellulose acetate and polyethylene terephthalate can be mentioned. be able to. These supports are
If necessary, an undercoating process or an antistatic treatment may be performed.

The developing agents used for processing the silver halide photographic light-sensitive material of the present invention include dihydroxybenzenes (eg, hydroquinone), aminophenol developing agents (eg, N-methyl-p-aminophenol), and 3-pyrazolidone development. Active agents (eg, 1-phenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-methyl-3-pyrazolidone, 1-phenyl-4,4-dihydroxymethyl-3 -Pyrazolidone) alone or in combination. Particularly, a combination of hydroquinone and 3-pyrazolidones or a combination of hydroquinone and aminophenols is useful for high-temperature rapid treatment.

The developer used for processing the silver halide photographic light-sensitive material of the present invention includes a preservative, an alkali agent, a pH buffer, an organic or inorganic antifoggant, a water softener, a development accelerator, and a color tone. Adjusters, surfactants, defoamers, hardeners, dissolution aids, thickeners and the like may be used as necessary.

The developing temperature is usually selected between 18 ° C. and 50 ° C., and more preferably 25 ° C. to 40 ° C. The processing method of the present invention is particularly suitable for rapid processing using an automatic developing machine. As the automatic developing machine, any of a roller-conveying machine, a belt-conveying machine and the like can be used. The processing time may be short, and the development processing time is preferably 5 to 60 seconds.

When processing is performed by an automatic developing machine, replenishment is generally performed in accordance with the processing amount of the photosensitive material in order to prevent deterioration of the developing solution due to the processing and to achieve a stable running state. In the present invention, the bromide concentration in the developer must be kept at 10 g / l or less, preferably 8 g / l or less, in terms of potassium bromide. The bromide ion concentration in the developer in the equilibrium running state is
It is almost determined by the amount released from the photosensitive material, the replenishment amount, and the concentration in the replenisher. Further, the amount of release from the light-sensitive material increases in proportion to the blackening rate. The blackening rate can vary depending on the image to be obtained, but in the case of medical images, it is predominant to cover the area other than the image area with black solid to facilitate observation on Schaukasten. Assuming rates is generally appropriate.

Under these circumstances, in order to keep the bromide concentration in the developer at 10 g / liter or less in terms of potassium bromide,
Although it is easiest to increase the replenishment amount, in the present invention, the replenishment amount must be 200 ml or less per m ² of the processed light-sensitive material. The replenisher may have the same composition as the developer used first as long as the replenishment amount satisfies this condition, or may be different. The bromide ion concentration in the developer can be easily determined by a method such as X-ray fluorescence analysis.

In the fixing solution, sodium thiosulfate, ammonium thiosulfate, etc. are used as a fixing agent, water-soluble aluminum (for example, aluminum sulfate, potassium alum, etc.) as a hardening agent, and dibasic acid as an aluminum precipitation inhibitor. (For example, tartaric acid, potassium tartrate, sodium tartrate, sodium citrate, lithium citrate, potassium citrate, etc.), and further, a sulfite, a bisulfite as a preservative, and acetic acid, boric acid, etc. as a pH buffering agent. .

[0026]

EXAMPLES The present invention will be described below in detail with reference to examples, but is of course not limited thereto. Example 1 <Preparation of silver iodobromide seed emulsion> A deionized lime-processed ossein gelatin aqueous solution (8% by weight) was kept at 60 ° C and p
While keeping Ag at 7.5, aqueous silver nitrate solution, potassium bromide,
An aqueous potassium iodide solution (containing potassium hexachloroiridate (III) in an amount of 2.5 × 10 ⁻⁷ mol per mol of silver) is added by a double jet method, and the average particle size is 0.10 μm.
m Monodispersed cubic silver iodobromide particles (1 mol% of iodide) having a variation coefficient of 13% were obtained.

The silver iodobromide grains were used as seed crystals, and further an aqueous silver nitrate solution and an aqueous halide solution (rhodium chloride having a molar amount shown in Table 1 per mole of silver) so as to have a halide composition shown in Table 1. Was added by a double jet method to obtain monodispersed cubic silver iodobromide particles having a mean particle size shown in Table 1. The emulsion was coagulated by flocculation using a styrene sulfonic acid-maleic anhydride copolymer and sodium sulfate as a coagulation aid, washed with water, and re-dissolved by adding gelatin to obtain emulsions A to H.

Emulsions A to H obtained as described above were each subjected to 65 ° C.
After adding sodium thiosulfate, chloroauric acid, and ammonium thiocyanate to each of the emulsions for optimal chemical sensitization, 4-hydroxy-6-methyl-1,3,3, a, 7-tetrazaindene was added. Was added. Further, an optimum amount of the following sensitizing dye and the following additives were added to each emulsion to prepare a silver halide emulsion coating solution.

[0029]
5-Nitroindazole 8 mg 1-phenyl-5-mercaptotetrazole 10 mg Styrene-maleic anhydride copolymer (Mw = 3000) 3 g Surfactant S-1 1.5 g Acrylate latex 6 g 1,3-vinylsulfonyl per mole of silver halide 0.8 g of 2-propanol

[0030]

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(Preparation of Emulsion Surface Side Protective Layer Coating Solution)
1 m ² per acid processed ossein gelatin 1.2g Colloidal silica 0.5g polymethylmethacrylate particles (4 [mu] m) 10 mg acrylate latex 0.2g sodium polystyrene sulfonate 150mg surfactant S-1 40 mg Surfactant S-2 0.7 mg 1, 3 -Vinylsulfonyl-2-propanol 40mg

[0032]

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The silver halide emulsion layer and the protective layer described above were coated on a subbed 7 mil polyethylene terephthalate base having a backing layer of the following composition so that the silver content was as shown in Table 1. The amount of gelatin in the silver halide emulsion layer was 2.8 g / m ² . All samples were annealed at 40 degrees for 7 days and then evaluated as follows.

(Preparation of Backing Layer Coating Solution) Lime-treated gelatin 3.0 g per 1 m ² Polymethyl methacrylate particles (6 μm) 20 mg Acrylate latex 1 g Antihalation dye AH-1 100 mg Sodium polystyrene sulfonate 250 mg Surfactant S-1 60 mg Interface Activator S-2 0.7mg 1,3-vinylsulfonyl-2-propanol
120mg

[0035]

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Sensitometry was performed using He at a wavelength of 633 nm.
After printing the wedge image with a -Ne laser beam, the wedge image was processed with a developer having the following composition by a Processor 260 roller transport type automatic developing machine manufactured by Duerr Dental at 36 ° C. for 20 seconds. The maximum value of the slope where the transmission density was between Dmin + 0.1 and 2.5 was measured and defined as the maximum value of gamma. Sensitivity value is Dmin +
It was a reciprocal of the exposure amount giving 1.3, and was evaluated as a relative value with the sensitivity of Sample No. 1 being 100. Fog is a value obtained by subtracting the base density from the density when an unexposed sample was processed at 38 ° C. for 40 seconds by the same automatic processor.

Further, test pattern exposure (SMPTE, RP-133
Compliant) and the gradation was confirmed. The test pattern exposure
Using a 633 nm He-Ne laser imager, adjust the reference laser intensity so that 50% of the gray scale can be reproduced at an optical density of 1.3, and expose the gray scale (0 to 100%) in the test pattern. The linearity was visually evaluated on a five-point scale. 5 is the best, 1 is the worst, and 3 is the practically acceptable limit level. The results are shown in Table 1.

<Developing solution formulation> Potassium sulfite 60 g Potassium carbonate 45 g Potassium hydroxide Amount required to adjust pH to 10.5 Hydroquinone 15 g 4-methyl-4-hydroxymethyl-1-phenyl 1.0 g -3-pyrazolidone diethylenetriaminepentaacetic acid 1.2 g Potassium bromide 3.0 g 5-Methylbenzotriazole 0.3 g Compound (AS) 0.4 g Add water to make 1 liter.

[0039]

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[0040]

[Table 1]

From Table 1, it can be seen that the silver halide photographic light-sensitive material of the present invention has low fog and excellent gradation without significant decrease in sensitivity.

Example 2 <Preparation of silver iodobromide emulsion> Silver iodobromide having a halide composition of Cl / Br / I = 0/99/1 and a grain size of 0.22 μm was prepared in the same manner as in Example 1. An emulsion was obtained (emulsion I). After subjecting this emulsion and a part of the emulsion obtained in Example 1 to chemical sensitization and spectral sensitization in the same manner as in Example 1, and mixing them at the ratios shown in Table 2, Example 1
The same additives as described above were added to prepare a silver halide emulsion coating solution.

The thus obtained silver halide emulsion layer and the same protective layer as in Example 1 were simultaneously coated on the same polyethylene terephthalate base as in Example 1, and annealed at 40 ° C. for 7 days.

Using the sample prepared in the above manner and a part of the sample in Example 1, a running test was conducted in the following manner. First, the wedge-exposed samples were processed in a new liquid state, and each sample was blackened to 70%.
Continuous processing up to 50 m ² with the same automatic developing machine (tank capacity 2.6 liters) as in Example 1 while replenishing the replenisher at 0 ml / m ² with the only difference that potassium bromide was removed from the developer used in Example 1. Then, the same wedge-exposed sample as the first sample was processed again. From the new solution to the end of the running, the sensitivity, the change in the maximum density, and the bromide concentration in the developing solution at the end of the running were measured. The bromide concentration was determined by elemental analysis using fluorescent X-rays. The results are shown in Table 2.

[0045]

[Table 2]

From Table 2, it can be seen that the photographic characteristics are stable even under low replenishment conditions by the method for processing a silver halide photographic light-sensitive material according to the present invention.

[0047]

According to the present invention, it is possible to provide a silver halide photographic light-sensitive material having low fog and excellent gradation, and a processing method having high processing stability even at the time of low replenishment.

Claims (2)

[Claims] 1. A support having at least one photosensitive silver halide emulsion layer on at least one surface of a support, wherein the total halide composition of the emulsion layer contains 50 mol% or more of chloride, and When a silver halide emulsion grain containing 50 mol% or more contains 10 ^-9 to 10 ^-7 mol of a rhodium compound per mol of silver halide and is exposed to laser light, the optical density is expressed as a logarithm of the exposure amount. Characterized in that the slope does not exceed 3 over the entire characteristic curve obtained for 2. The silver halide photographic light-sensitive material according to claim 1, wherein the replenishment amount of the developer is not more than 200 ml / m ² and the bromide concentration in the developer is less than 10 g / l in terms of potassium bromide. A method for processing a silver halide photographic light-sensitive material, characterized by processing under dripping conditions.