JP806H - Silver halide photographic material for X-ray - Google Patents

Description

TECHNICAL FIELD The present invention relates to a silver halide photographic light-sensitive material for X-rays having high diagnostic ability. More specifically, the present invention relates to a silver halide photographic light-sensitive material for X-rays which has a wide exposure latitude in a high density portion, is easy to use, has a high sharpness and is easy to diagnose. [Prior Art] A silver halide photographic light-sensitive material for X-rays (one having a photosensitive emulsion layer on both sides of a support and one having a light-sensitive emulsion layer on only one side thereof will be referred to below as both). In X-ray photography of each part of a living body by "X-ray sensitive material"), high diagnostic ability is required for early detection of lesions and prevention of misdiagnosis, but conventional X-ray sensitive materials are not always necessary. I'm not satisfied. That is, conventional direct X-ray sensitive materials are roughly classified into a high gamma type shown in (a), a low gamma type shown in (b), and a moderate type shown in (c) in the photographic characteristic curve of FIG. , The high gamma type (a) is
Although the sharpness is high, it is difficult to use because the exposure latitude is narrow, and the low gamma type (b), on the contrary, has a wide exposure latitude and is easy to use, but it is difficult to diagnose due to low sharpness, and the moderate type (c) Has only a moderate sharpness and exposure latitude. In each of these types of direct-use X-ray sensitive materials, in the characteristic curve when treated with the same developer-1 as in the present invention, a gamma (gamma 1) between an optical density of 0.50 and an optical density of 1.50, and Typical examples of gamma (gamma 2) between the optical densities of 2.00 and 3.00 are shown in Table 1. In the actual examples of X-ray photography using these conventional type direct X-ray sensitive materials, the following serious defects or inconveniences were sometimes observed. That is, the most living body part of X-ray photography in Japan is the stomach, and a contrast agent is used to enhance the descriptive power. However, in the conventional high-gamma type direct X-ray sensitive material, the contrast agent portion is exposed. If you match the amount,
After development, the image without a contrast agent gave only a black image, which could not contribute to diagnosis. In order to avoid such a phenomenon, a low gamma type direct X-ray sensitive material is often used. However, in the case of this X-ray sensitive material, on the other hand, since the sharpness decreases, the stomach wall portion containing a contrast agent is reduced. The diagnostic ability of is reduced. As a practical example of X-ray photography of another living body part,
There are images of bones and soft tissues (flesh or cartilage) of hands and legs, and even in this case, the sharpness of the fine structure of bones is high in the conventional high gamma type X-ray sensitive material. However, the soft tissue was crushed in black and could not contribute to the diagnosis. On the contrary, when the low gamma type X-ray sensitive material was used, the soft tissue was depicted, but the sharpness of the bone was low. [Object of the Invention] Therefore, an object of the present invention is to provide an X-ray sensitive material having a high sharpness, a wide exposure latitude in a high density portion, and a high diagnostic ability. [Structure of the Invention] The X-ray sensitive material of the present invention which achieves the above object has a characteristic curve when treated under the following processing conditions using the developer-1 having the following composition. The gamma between
It is characterized in that the gamma between 2.7 and 3.3 and the optical density between 2.00 and 3.00 is 1.5 to 2.5. Developer-1 In a preferred embodiment of the present invention, in the characteristic curve when treated with the developing solution-1, the gamma between the optical densities of 0.50 and 1.50 is 2.8 to 3.1, and the optical density of 2.00 is the same.
The gamma between 3.00 and 1.7 is 2.3. The characteristic curve referred to in the present invention is obtained by the following optical sensitometry [A]. (Photosensitometry [A]) The exposure is carried out by sandwiching an X-ray sensitive material having a photosensitive emulsion layer on both sides (or one side) of a transparent support between two optical wedges and a light source having a color temperature of 5,400 ° K. At the same time, expose both sides at the same amount for 1/10 seconds. The processing is carried out using an automatic processor such as a roller transfer type according to the following steps. The developing solution used at this time is the developing solution-1, and the fixing solution is not particularly limited as long as it is an acidic hardening fixing solution, and is, for example, Sakura XF (manufactured by Konishi Rokusha Kogyo Co., Ltd.). In the present invention, gamma is the base (support) on the characteristic curve.
It means the slope of the straight line connecting the density +0.50 density point and the base density +1.50 density point, and the base density +2.00 density point and the base density +3.00 density point It means the slope of the straight line connecting the. More specifically, if the angle at which these directs intersect the exposure amount axis (horizontal axis) is θ, it means tan θ. The method for obtaining the characteristic curve of the present invention is arbitrary, and a monodisperse emulsion, a polydisperse emulsion, a core-shell type monodisperse emulsion, a single-use or a combination of two or more core-shell type polydisperse emulsions, a grain size or a grain size. Any technique such as control of distribution, adaptation of silver halide crystal habit, use of photographic additives such as hardeners and development control agents may be used. A specific example of obtaining the characteristic curve of the present invention is as follows. The first method is to use a silver halide emulsion containing a mixture of large-grain silver halide grains and small-grain silver halide grains. For example, a monodisperse (preferably core-shell type) emulsion having an average grain size of 1.35 μm and a monodisperse (preferably core-shell type) emulsion having an average grain size of 0.65 μm are each optimally chemically sensitized, and then silver halide is added. It is achieved by mixing in a molar ratio of 3: 1. As another example of this mixed content, for example, a monodisperse (core-shell type) emulsion having an average grain size of 1.25 μm and a monodisperse (core-shell type) emulsion having an average grain size of 0.70 μm are optimally used. After chemical sensitization, the mixture is carried out at a molar ratio of silver halide of 4: 1. The second method is by mixing a monodisperse emulsion and a polydisperse emulsion. For example, after optimally chemically sensitizing a monodisperse emulsion having an average grain size of 1.35 μm and a polydisperse emulsion having an average grain size of 0.75 μm,
This is achieved by mixing the silver halide in a molar ratio of 3: 1. Other examples of this mixed content include, for example, the average particle size.
The optimum is to chemically sensitize a monodisperse emulsion having a grain size of 1.15 μm and a polydisperse emulsion having an average grain size of 0.55 μm, and then mix them at a molar ratio of silver halide of 4: 1. The silver halide used in this method is also preferably the core-shell type. A third method is to use a large amount of a hardener for a photosensitive silver halide (monodispersity, especially core-shell type monodispersity is preferred) emulsion having a very high gamma. Therefore, it is possible to increase the degree of dura. That is, by increasing the degree of hardening, the gamma of the high density part of the characteristic curve becomes lower than that of the middle density part.
The method of applying the type and usage of the hardener may be a method known in the photographic industry, for example, an aldehyde compound, a ketone compound, a halogen-substituted acid such as mucochloric acid, an ethyleneimine compound, a vinylsulfone compound, etc. Can be used. A fourth method is to add a kind of development inhibitor to a photosensitive silver halide (monodispersity, especially core shell type monodispersity is preferable) emulsion having very high gamma. Therefore, it is possible to preferentially soften the high-density portion of the characteristic curve. The kind of such a development inhibitor and the application method such as usage may be a method known in the photographic industry, and for example, an indazole compound or a mercapto-succinic acid compound may be preferably used. The monodisperse emulsion used in the first and second methods of the present invention can be prepared by a conventional method, for example, The Photographic Journ
al, 79 , 330-338 (1939), the method reported by trivelli, Smith measured the average particle diameter and found that at least 95% of the particles by number or weight were ± 40% of the average particle diameter.
Within the range, more preferably within ± 30% of the silver halide emulsion. A method for producing such a monodisperse emulsion is known, and for example, J. Phot.S.
ci., 12 , 242-251 (1963), Japanese Patent Publication No. 48-36890,
No. 52-16364 and Japanese Patent Laid-Open No. 55-142329, and Japanese Patent Application No. 56-65573.
The techniques described in the specification can also be adopted. The silver halide used in the present invention may be a core-shell type monodisperse dispersion, and these core-shell emulsions are known from JP-A-54-48521. The silver halide grains used in the present invention are, for example, those described in T.W.
H. “The Theory of the Photographic Proces” by James
s "4th edition, published by Macmillan (1977), pages 38-104, etc., neutral method, acidic method, ammonia method, forward mixing, back mixing, double-jet method, controlled-double-jet method, It can be produced by applying methods such as the Convurion method, the core / shell method, etc. The silver halide composition includes silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide, etc. Either of can be used,
The most preferred emulsion is a silver iodobromide emulsion containing less than about 10 mol% silver iodide. The grain size of silver halide grains is
There is no particular limitation, but 0.1-2 μm is preferable. Further, in order to improve the flash exposure characteristics, these silver halide grains or silver halide emulsions contain iridium salts and / or
Alternatively, a rhodium salt may be contained. As a hydrophilic protective colloid which is a dispersant for silver halide, gelatin is preferable, and various natural or synthetic colloid substances such as gelatin derivatives and polyvinyl alcohol are used alone or in combination with gelatin. As the sensitizer which can be advantageously used in the present invention, a noble metal sensitizer, for example, a gold compound, ruthenium, rhodium,
Palladium, iridium, platinum, etc., and sulfur sensitizer,
Active gelatin, sulfur compounds, etc. or selenium sensitizer if standing
For example, active and inactive selenium compounds and the like, further reduction sensitizers such as monovalent tin salts, polyamines, silane compounds, bisalkylamino sulfides, isinoaminomethane sulphonic acid, hydrazinium salts, hydrazine derivatives and the like, and the above 4 It can be roughly divided into species. These sensitizers can be chemically sensitized individually or in combination. Further, if necessary, spectral sensitization or supersensitization can be performed by using dyes alone or in combination, or by using them in combination with a styryl dye. In the present invention, the silver halide emulsion layer may contain a stabilizer such as triazoles, tetrazoles, imidazoles, azaindenes, quaternary benzothiazolium compounds, zinc or cadmium compounds. Further, a quaternary ammonium salt type or polyethylene glycol type sensitizing compound may be contained. And it also contains a suitable gelatin plasticizer such as glycerin, dihydroxyalkanes such as 1,5-pentanediol, ethylene bisglycolate ester, bis-ethoxydiethylene glycol succinate, acrylic acid amide, and latex. it can. Further, various photographic additives such as the above-mentioned hardener, spreading agent such as saponin, and coating aid such as sulfosuccinate can be contained. Furthermore, if necessary, various additives commonly used in photography such as antifoggants and ultraviolet absorbers can be included. As the support used for the X-ray sensitive material according to the present invention, for example, various ones such as polyester film such as polyethylene terephthalate, polyamide film, polycarbonate film and styrene film are used, and these are dyed blue or the like. And may be appropriately selected depending on the purpose of use. [Advantageous effects of the invention] According to the present invention, since the high sharpness and the width of the exposure latitude of the high density portion are solved at the same time, it is possible to provide an X-ray sensitive material having a high diagnostic ability, and in particular, a stomach using a contrast agent. It is possible to eliminate the drawbacks of the conventional type in the case of partial imaging and imaging of bone and soft tissue. [Examples] Next, the present invention will be illustrated with reference to Examples, but the embodiments of the present invention are not limited thereto. Example-1 A potassium bromide solution containing 2.5 mol% of potassium iodide and an ammoniacal silver nitrate solution were added to a gelatin aqueous solution by the double jet method while gradually increasing the flow rate to 1.05 μm.
A silver iodobromide octahedron monodisperse emulsion was obtained. Further, an ammoniacal silver nitrate solution and a potassium bromide solution were added by a double jet method to cover with pure silver bromide shell. During this period pAg
Was maintained at 10.0 and the pH was gradually decreased from 9.0 to 8.0.
This emulsion is designated as [A]. This emulsion [A] has an average grain size of 1.
It was a 25 μm regular octahedral monodisperse emulsion. Also, the average grain size is 0.65 μm in the same manner as the above emulsion [A].
A regular octahedral monodisperse emulsion [B] was prepared. Further, a silver iodobromide emulsion having the same halide composition as the emulsions [A] and [B] was prepared by a forward mixing method to obtain an emulsion [C]. This emulsion [C] was a Sosho type polydisperse emulsion having an average grain size of 1.25 μm. Also, a Sochang type polydisperse emulsion [D] having an average particle size of 0.65 μm was obtained by the same production method as the emulsion [C]. After desalting, these emulsions were subjected to gold sensitization and sulfur sensitization, and then 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added to stabilize the emulsion. The emulsions were mixed. Further, after adding general photographic additives such as a spreader and a hardener, the amount of silver on each surface becomes 30 mg / 100 cm ² on a polyethylene terephthalate film base dyed blue and subbed As described above, both surfaces were coated and dried to prepare samples for direct X-ray sensitive material (No. 1 to 10). Sensitometry of each of these samples was carried out by the developer of the present invention-
The sensitometry [A] used in Example 1 was used. In addition, the developing machine is a roller transport type automatic developing machine New QX-1
It was treated with 200 (manufactured by Konishi Rokusha Kogyo Co., Ltd.). The results are shown in Table-2. The evaluation of sharpness is OT
An OTF measurement chart containing a rectangular wave of 1.0, 1.5, 2.0 lines / mm of the F curve and containing a rectangular wave made of lead was brought into close contact with the back surface of the front side of the fluorescent screen, and was not shielded by the rectangular wave of lead on the sample surface. X-ray irradiation was performed so that the density of the part was 1.0 on both sides, the back side of the emulsion was peeled off, and the rectangular wave pattern on the other side was made using the Sakura Micro Densitometer M-5 (Konishi Roku Photo (Manufactured by Kogyo Co., Ltd.) was used for scanning measurement in the direction perpendicular to the rectangular wave. The aperture size at this time is 230 μm in the parallel direction of the rectangular wave and 25 μm in the perpendicular direction, and the magnification is 100 times. The exposure latitude was evaluated by the difference in exposure amount (logarithmic display) between the optical density of the base density + fog density + 2.00 and 3.00. As is clear from Table 2, samples satisfying the conditions of the present invention
It can be seen that No. 2 and No. 7 have high sharpness and a wide exposure latitude in the high density area. Example-2 The emulsion [A] of Example-1 was chemically sensitized, coated and dried in the same manner as in Example-1 to obtain sample Nos. 11-14. However, the amount of the hardener was changed as shown in Table-3. Sensitometry and evaluation of laboratories were performed as in Example-1, and the results are shown in Table-3. As is clear from Table 3, samples satisfying the conditions of the present invention
It can be seen that No. 12 and No. 13 have high sharpness and a wide exposure latitude in the high density portion. Similar results were obtained even when the hardener was changed from glyoxal to S-triazine. Example-3 It was prepared in the same manner as the emulsion [A] of Example-1. However, pA
Emulsion [E] was prepared except that g was kept at 9.0. This emulsion [E] was a cubic monodisperse emulsion having an average grain size of 1.25 μm. This emulsion [E] was chemically sensitized, coated and dried in the same manner as in Example-1 to obtain sample Nos. 15-17. However, the development inhibitors shown in Table 4 were added to the emulsion additives. The sensitometry of these samples and the evaluation of compartments were performed as in Example-1, and the results are shown in Table-4. As is clear from Table 4, samples satisfying the conditions of the present invention
It can be seen that Nos. 15 to 17 have high sharpness and a wide exposure latitude in the high density portion. Comparative Example By the method of Example 1, a 1.25 μm silver iodobromide octahedral monodisperse emulsion [A] was obtained. Similarly, a regular octahedron monodisperse emulsion [B] of 0.65 μm was obtained. Further, a 1.25 μm twin type polydisperse emulsion [C] and a 0.65 μm twin type polydisperse emulsion [D] were similarly obtained. A 1.15 μm silver iodobromide octahedral monodisperse emulsion [E] having a high monodispersity was obtained by the controlled double jet method. Furthermore, by changing the mixing time in the forward mixing method, a more polydisperse twin crystal polydisperse emulsion [F] of 0.55 μm was obtained from [D]. Using these emulsions, Example-1
A sample was prepared and evaluated in the same manner as in. The mixing ratio of emulsions is shown in the table.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing a photographic characteristic curve of a conventional type direct X-ray sensitive material. In the figure, (a) shows a high gamma type, (b) shows a low gamma type, and (c) shows a moderate type.

Claims (1)

[Claims] [Claims] [Claims] [Claim 1] An optical density of 0.50 in a characteristic curve when a developer-1 having the following composition is processed under the following processing conditions.
And gamma between 1.50 and 1.50 are 2.7 to 3.3, and gamma between optical density 2.00 and 3.00 is 1.5 to 2.5, a silver halide photographic light-sensitive material for X-rays. Developer-1 Potassium sulfite 55.0 g Hydroquinone 25.0 g 1-Phenyl-3-pyrazolidone 1.2 g Boric acid 10.0 g Potassium hydroxide 21.0 g Triethylene glycol 17.5 g 5-Methylbenztriazole 0.04 g 5-Nitrobenzimidazole 0.11 g 1- Phenyl-5-mercaptotetrazole 0.015g Glacial acetic acid 1.60g Potassium bromide 4.0g Add water to finish to 1. Processing conditions Processing temperature Processing time Development 35 ° C 25 seconds Fixing 34 ° C 25 seconds Washing 33 ° C 25 seconds Drying 45 ° C 15 seconds