JPH06342197A - High definition silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To provide a silver halide photographic sensitive material, with which an image having excellent definition can be obtained at a low X ray exposure does and also a high definition image can be obtained even when two intensifying screens having the same emission wavelengths are used at the time of performing an X ray photographing. CONSTITUTION:The silver halide photographic sensitive material is obtained by providing at least one photosensitive silver halide emulsion layer on each of the both surfaces of a transparent substrate. In this sensitive material, the color sensitivity of the photosensitive silver halide emulsion layer on one surface of the substrate is different from that on the other surface of the substrate. At the same time, a dye which effectively absorbs the light in the maximum photosensitivity wavelength region for the photosensitive silver halide emulsion layer on one surface of the substrate is added to the silver halide emulsion layer on the other surface of the substrate or to at least one of layers interposed between the substrate and the photosensitive silver halide emulsion layer on the other surface of the substrate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a silver halide photographic light-sensitive material, and more particularly to a silver halide photographic light-sensitive material having high sensitivity and excellent image sharpness.

[0002]

BACKGROUND OF THE INVENTION For X-ray photography, a film having a photosensitive emulsion layer on each side of a support is sandwiched between two fluorescent intensifying screens, and a transparent X-ray is used.
A method of increasing the absorption efficiency of rays has been adopted. According to this photographing method, the light from the fluorescent intensifying screen on the front surface excited by X-rays is used as a light emission source to expose the photosensitive emulsion layer on the front surface, and the rear surface excited by X-rays transmitted through the front surface is exposed. Since the X-ray image is formed by exposing the emulsion on the back surface to light by the excitation light of the fluorescent intensifying screen, the X-ray can be effectively used, and the irradiation dose can be reduced. It is widely used for both medical and industrial purposes.

In recent years, in particular, X-ray diagnostic films and intensifying screens used for medical purposes have been made to have high sensitivity and high image quality in order to reduce human exposure dose and improve diagnostic accuracy. However, further improvement is desired, and in particular, improvement in sharpness of the X-ray diagnostic film is strongly desired because it is necessary to know the state of the lesion or affected area in more detail.

In the film having a photosensitive emulsion layer on both sides of the support, the light emitted from one fluorescent intensifying screen by X-ray irradiation sensitizes the photosensitive emulsion layer adjacent to the fluorescent intensifying screen. At the same time, it causes the phenomenon that the light is transmitted through the support and diffused by the support to give imagewise exposure (so-called crossover exposure) to the photosensitive emulsion layer on the opposite side, which deteriorates the sharpness of the image. Had a problem.

In order to reduce the above-mentioned crossover exposure and improve the sharpness, many proposals have been made in the past, for example, British Patent No. 821,352 or Japanese Patent Laid-Open Publication No.
JP-A 1-132945 describes that a silver halide emulsion layer or a constituent layer contains a dye.
In JP-A-8, the color sensitivity of the photosensitive emulsion layers provided on both sides of the support are different from each other, and each light sensitive emulsion layer is provided with an emission spectrum matching the color sensitivity of each light sensitive emulsion layer. It is described that a fluorescent intensifying screen that emits light is brought into close contact and exposed, and JP-A-3-46649 discloses a cassette and a photosensitive material that use fluorescent intensifying screens having different emission wavelengths in combination. , There is no disclosure of a method of suppressing crossover light so as not to affect the emulsion on the back surface, and these light-sensitive materials are used as fluorescent intensifying screens.
It was not possible to obtain a sufficiently sharp image using silver halide having an emission in the intrinsic sensitivity region of 0 to 470 nm.

Attempts have been made to provide a photosensitive emulsion layer on only one side of a support in order to prevent deterioration of image sharpness due to crossover exposure, but this method can provide high sharpness. However, the absorption efficiency of transmitted X-rays was poor, and there was a problem that the exposure dose to the patient increased.

Therefore, it has been desired to develop a silver halide photographic light-sensitive material having high sensitivity, capable of obtaining a desired image with a low X-ray exposure amount and excellent in sharpness.

[0008]

Therefore, the first aspect of the present invention
It is an object of the invention to provide a silver halide photographic light-sensitive material capable of obtaining an image with a low X-ray exposure amount in X-ray photography and having excellent sharpness. A second object of the present invention is to provide a silver halide photographic light-sensitive material capable of obtaining a highly sharp image in X-ray photography even if two fluorescent intensifying screens having the same emission wavelength are used. It is in.

[0009]

The above object of the present invention has been achieved by the following. (1) In a photographic light-sensitive material in which at least one light-sensitive silver halide emulsion layer is provided on both sides (A) and (B) of a transparent support, one surface (A) and the other surface (B)
And, the color sensitivity of the photosensitive silver halide emulsion layer is made different, and at least one of the photosensitive silver halide emulsion layer on the other surface (B) or the layer between the emulsion layer and the support is A silver halide photographic light-sensitive material, characterized in that it contains a dye which effectively absorbs light in the wavelength region of maximum light sensitivity to which the light-sensitive silver halide emulsion layer on one surface (A) is exposed. (2) In the silver halide photographic light-sensitive material described in (1) above, one of a photosensitive silver halide emulsion layer on one side (A) and a photosensitive silver halide emulsion layer on the other side (B). As a high-sensitivity layer and the other as a low-sensitivity layer. (3) The silver halide photographic light-sensitive material as described in (1) or (2) above, further comprising a light-sensitive silver halide emulsion layer on one surface (A) or a layer between the emulsion layer and the support. A silver halide photographic light-sensitive material, characterized in that at least one layer contains a dye which effectively absorbs light in the wavelength region of maximum light sensitivity to which the light-sensitive silver halide emulsion layer on the other side (B) is exposed.

The present invention will be described in detail below.

In the present invention, the sensitivity between the photosensitive silver halide emulsion layer provided on one surface (A) and the photosensitive silver halide emulsion layer provided on the other surface (B) of the transparent support. Although different in chromaticity, the difference in color sensitivity is preferably 50 nm or more at the maximum photosensitive wavelength. Examples of combinations of light-sensitive silver halide emulsions having different color sensitivities include a combination of regular emulsions and ortho-sensitized emulsions, and a combination of emulsions spectrally sensitized with dyes having different spectral sensitization regions. Can be mentioned.

Further, the silver halide photographic light-sensitive material of the present invention has one of the light-sensitive silver halide emulsion layer on one side (A) and the light-sensitive silver halide emulsion layer on the other side (B). The high-sensitivity layer and the other can be the low-sensitivity layer. In this case, the sensitivity characteristics of the silver halide emulsions provided on the respective surfaces can be set arbitrarily.

The maximum density of the developed silver image of the light-sensitive silver halide emulsion is usually preferably 2.5 or more for X-ray image diagnosis, and up to 3.5 is sufficient. The maximum density of the developed silver image of the photosensitive silver halide emulsion on each surface is preferably 0.4 or more, more preferably 0.5 or more and 2.5 or less. If there is an extreme difference in the maximum density of the developed silver image of the photosensitive silver halide emulsion on each side, various restrictions will occur and problems will occur, so there is no extreme difference in the maximum density on each side. preferable.

When a combination of a regular emulsion and an ortho-sensitized emulsion is used as a combination of silver halide emulsions having different color sensitivities, an ortho-sensitized emulsion is used as a high sensitivity emulsion and a regular emulsion is used as a low sensitivity emulsion. Alternatively, a regular emulsion may be used as the high-speed emulsion and an ortho emulsion may be used as the low-speed emulsion.

In the silver halide photographic light-sensitive material of the present invention, when the silver halide emulsion layers provided on the respective surfaces are made to have different sensitivities and one is a high sensitivity layer and the other is a low sensitivity layer, a high sensitivity layer is provided. From low density area to medium density area 2.0
It is preferable to form an image up to the vicinity thereof, and to form an image in the low sensitivity layer on the opposite side from a density of about 0.5 in the medium density region to a density of about 3.0 in the high density region. In diagnostic X-ray images, a particularly useful density range is from fog density to 1.6 to 2.3. Graininess due to X-ray quantum mottle (noise) tends to stand out in a region of density 0.8 or less. Therefore, in order to reduce sharpness and suppress deterioration of graininess due to quantum mottle (noise), graininess is low even if sharpness is low. It is preferable to form an image using a fluorescent intensifying screen having good image quality, and it is preferable to form an image using a fluorescent intensifying screen having a high sharpness in the region of 0.8 or more.

The regular emulsion used in the present invention has a spectral sensitivity based on the photosensitivity peculiar to silver halide, and the regular emulsion used by the cyanine dye disclosed in JP-A-56-111849. It may be sensitized. The ortho-sensitized emulsion used in the present invention is, for example, one sensitized with a spectral sensitizing dye so that the maximum wavelength of the light-sensitivity is in the range of 500 nm to 580 nm.
mer “Heterocyclic compound-Cyanine dyes and rela
ted compound "John Wiley & Sons (New York, London)
It can be obtained by sensitizing with the dyes described in 1964 published by the company.

In the present invention, the sensitivity of the silver halide emulsion layer is determined by the light source used in using the light-sensitive material. For example, the sensitivity of the regular emulsion layer is as follows. The emission light of the phosphor used in the fluorescent intensifying screen used for exposure of the regular emulsion layer in X-ray film photography is used as the light source, and the sensitivity of the ortho-sensitized emulsion layer is It was measured by using the emitted light of the phosphor used in the fluorescent intensifying screen used for ortho-sensitized emulsion layer exposure in X-ray film photography as a light source. The measurement is performed by using a sensitive paper as a light source.

The sensitivity is the highest density obtained by development.
It is given as the reciprocal of the X-ray dose required to obtain an optical density of 40%.

As the optical density, a diffusion density obtained by using an optical system having a luminous efficiency spectral product distribution according to the ISO standard is used.

The light-sensitive material of the present invention is different from the ordinary double-sided light-sensitive material for X-ray photography and prevents the emulsion layer on the opposite side from being exposed to light by the light which has passed through the support and reached the opposite emulsion layer. Therefore, the deterioration of sharpness is less than that of a normal double-sided light-sensitive material, but in order to further prevent the deterioration of sharpness due to crossover light, the emulsion layer on the opposite surface that penetrates the support to reach the opposite surface. It is preferable that the transmitted light amount (crossover light) of light having a wavelength that sensitizes is small. The transmitted light that passes through the support and reaches the opposite surface is preferably 35% or less, and more preferably 25% or less of the light amount of the light source.

In the silver halide photographic light-sensitive material of the present invention, at least one of the light-sensitive silver halide emulsion layer provided on the surface (B) or the layer between the emulsion layer and the support is A dye (pigment) that effectively absorbs light in the wavelength region of the maximum light sensitivity of the photosensitive silver halide emulsion layer provided in A).
Contains. Further, at least one of the light-sensitive silver halide emulsion layer provided on the surface (B) or the layer between the emulsion layer and the support is provided on the surface (A). At least the photosensitive silver halide emulsion layer provided on the surface (A) or a layer between the emulsion layer and the support, which contains a dye that effectively absorbs light in the wavelength region of maximum light sensitivity to light. One layer contains a dye which effectively absorbs light in the wavelength region of the maximum photosensitive wavelength which the photosensitive silver halide emulsion layer provided on the surface (B) is sensitive to.

When these dyes are contained in the light-sensitive silver halide emulsion layer, dyes having a complementary color relationship with light in the maximum light-sensing wavelength range to which the silver halide emulsion provided on the opposite surface of the support is exposed are preferable. For example, the dye contained in the photosensitive silver halide emulsion layer provided on the surface (B) may be a complementary color to the light in the maximum wavelength region of the light sensitive to the photosensitive silver halide emulsion layer provided on the surface (A). Dyes having the relationship of are preferred. These dyes are preferably added in an amount that reduces the ability of the fluorescent intensifying screen to expose the emulsion layer provided on the opposite side to 1/2 to 1/30. 3 to 600 mg / m ² .

The dye used preferably satisfies the following two requirements.

1) Be chemically inert. For example, adverse effects of chemical meaning on the performance of emulsions (decreased sensitivity, latent image regression,
Fog etc.) is not given.

2) It is not discolored in the photographic processing agent step, or is not dissolved in the processing solution or the washing water to cause color residue in the processed light-sensitive material.

The dyes usable in the present invention include:
For example, an oxonol dye having a pyrazolo nucleus or a barbituric acid nucleus described in JP-A-62-215272, an azomethine dye, an anthraquinone dye, an arylidene dye, a styryl dye, a triaryl dye, a merocyanine dye, a cyanine dye, U.S. Pat. Mention may be made of the solid disperse dyes disclosed in the specification. In particular,
Examples include magenta filter dyes and yellow filter dyes described in JP-B-61-116349.

The dye is contained in at least one of the light-sensitive silver halide emulsion layer or the layer between the emulsion layer and the support. The layer between the photosensitive silver halide emulsion layer and the support may be an undercoat layer or a hydrophilic layer provided separately from the undercoat layer.

A fluorescent intensifying screen is used for X-ray photography using the silver halide photographic light-sensitive material of the present invention. As these fluorescent intensifying screens, commercially available fluorescent intensifying screens usually used for X-ray diagnosis in the industry can be used. For example, as the fluorescent intensifying screen for orthofilm, a commercially available fluorescent intensifying screen manufactured by Konica Corporation is used. Various ortho fluorescent screens represented by CL series manufactured by Kasei Opto Co., Ltd.
As the fluorescent intensifying screen for regular film, NR series manufactured by Konica Corporation and V series manufactured by Kasei Opto Corporation can be used.

For X-ray photography using the silver halide photographic light-sensitive material of the present invention, it is preferable to use a fluorescent intensifying screen most suitable for the color sensitivity of the emulsion layers on both sides of the support. The silver halide photographic light-sensitive material has the advantage that high sharpness can be obtained even if a fluorescent intensifying screen having the same light-emitting property is used.
The fact that fluorescent intensifying screens with the same emission characteristics can be used means that fluorescent intensifying screens can be set without considering the photosensitive characteristics on both sides of the silver halide photographic light-sensitive material. This means that you can save time and effort.

The film cassette used for X-ray photography using the silver halide photographic light-sensitive material of the present invention is
The cassette may be made of aluminum or a resin cassette, but a resin cassette reinforced with carbon fiber is preferable because it has a small amount of radiation absorption and a small change in X-ray quality.

When the silver halide photographic light-sensitive material of the present invention is composed of a regular emulsion and an ortho-sensitive emulsion, the cassette has a regular emulsion layer on the front side and an ortho-sensitive emulsion on the back side. The structure may include layers, or the reverse structure.
The fluorescent intensifying screen may be the same on both sides of the cassette, but if the regular emulsion layer is on the front side and the ortho-sensitive emulsion layer is on the back side,
A regular film fluorescent intensifying screen on the front side, and an ortho film fluorescent intensifying screen on the back side are preferably attached, and when the cassette has the opposite configuration,
The arrangement of the fluorescent intensifying screen is preferably reversed.

In this case, it is necessary to distinguish between the front and the back of the cassette, as in the case of a light-sensitive material coated with an emulsion on one side. To distinguish between the front and the back, it is disclosed in Japanese Patent Publication No. 3-155546. Can be installed.

The silver halide photographic light-sensitive material of the present invention comprises a photographic emulsion layer, a non-light-sensitive intermediate layer, a protective layer, and a layer for preventing halation and irradiation, as well known in the art. The constituent layers such as the support layer can be colored.

The silver halide emulsion used in the silver halide photographic light-sensitive material of the present invention is silver iodobromide, silver iodochloride,
Although any silver halide such as silver iodochlorobromide may be used, silver iodobromide is preferable from the viewpoint of high sensitivity.

The silver halide grains in the silver halide emulsion had isotropic growth such as cubes, octahedra, and tetrahedra, or polyhedral crystals such as spheres, and plane defects. It may be composed of twins or a mixed type thereof.

Further, the silver halide grain may be a silver halide emulsion having tabular grains having an aspect ratio of 2 or more.

The silver halide emulsion having tabular grains is
It has the advantages that the spectral sensitization efficiency can be improved and the graininess and sharpness of the image can be improved. Silver halide emulsions having tabular grains are described, for example, in British Patent 2,112,15.
No. 7, U.S. Pat.No. 4,439,520, No. 4,433,
No. 048, No. 4,414,310, No. 4,434,226
No. 58, No. 58-113927, No. 58-127921, No. 63-138342, No. 63-284272, No. 63-
The emulsion can be prepared by the methods described in these specifications and publications.

The grain size of the silver halide grains may be from fine grains of 0.1 μm or less to large grains of 20 μm.

The silver halide emulsion may be either a monodisperse emulsion having a narrow grain size distribution of silver halide grains or a polydisperse emulsion having a broad grain size distribution.

The monodisperse emulsion referred to herein means that when the average particle diameter is measured by a conventional method, at least 95% of the particles by number or weight are within ± 40% of the average particle diameter, preferably within ± 30%. It refers to a silver halide emulsion having certain silver halide grains.

Further, the definition of monodispersity is disclosed in JP-A-60 / 60
No. 162244, the monodisperse emulsion according to the definition has a coefficient of variation of grain size of 0.20 or less.

The silver halide grains may have different silver halide compositions from the inside to the outside. A preferred embodiment of the emulsion is a core / shell type monodisperse emulsion having a double structure in which a core layer having a high silver iodide content is provided with a shell layer having a low silver iodide content. The silver iodide content of the high iodine portion is preferably 20 to 40 mol%, particularly preferably 20 to 30 mol.

These silver halide emulsions are disclosed, for example, in JP-A-59-177535, JP-A-61-116347 and JP-A-61-1329.
No. 43, No. 63-49751, and Japanese Patent Application No. 63-238225.

Regular silver halide emulsions and orthophotosensitive emulsions can be preferably used as the silver halide emulsions having different color sensitivities in the present invention. These regular emulsions include, for example, a silver iodide content of 1.0 that is not spectrally sensitized.
It is preferable to use silver iodobromide or silver chloroiodobromide grains in an amount of not more than mol. Examples of the orthophotosensitive emulsion include silver iodobromide having a silver iodide content of less than 1.0 mol, silver bromide, and chloroiodo odor. Silver halide or silver chlorobromide, and an average aspect ratio of 2 or more 30
Those having the following tabular grains are preferred. Further, it is preferable to use tabular grains described in Japanese Patent Application No. 4-78180.

The emulsion used in the silver halide photographic light-sensitive material of the present invention can be produced by a known method. For example, Research Disclosure (RD) No.18716 (November 1979)
・ Pages 22 to 23 1. Emulsion Preparation
and types) and the same (RD) No. 18716, page 684. Also, for example, THJame
s The "The theory of the photographic process", 4th edition, published by Macmillan (1977), pages 38-104, GF Daufin "Photoemulsion Chemistry""PhotographicE"
mulsion Chemistry ”Focal Press, 1966, P.
"Film Physics and Chemistry" by Glafikides "Chimie et Physi
que Photographique ”published by Paul Montel (1967
, VL Zelikman et al., "Making and Coating Photographic Emulsions""M
aking and coating Photographic emulsion ”Focal Pr
It can also be prepared by the method described in, for example, ess company (1964).

The silver halide emulsion of the present invention can be mixed under a solution condition such as a neutral method, an acidic method or an ammonia method under a forward mixing method, a reverse mixing method, a double jet method, a controlled double jet method or the like. It can be produced using a particle preparation condition such as a conversion method, a core / shell method, or a combination thereof.

The monodisperse emulsion can be obtained, for example, by using a seed crystal and growing grains by supplying silver ions and halide ions with the seed crystal as a growth nucleus. The silver halide emulsion of the present invention can be obtained. For this, a monodisperse emulsion is particularly preferable.

A method for producing a monodisperse emulsion is known, and for example,
J. Phot. Science 12, pp.242-251 (1963), JP-A-48-36
890 publication, 52-16364 publication, 55-142329 publication,
No. 58-49938, British Patent No. 1,413,748, US Pat. No. 3,574,628, and No. 3,655,394.

A method for producing a core / shell type emulsion is also known, for example, British Patent No. 1,027,146, US Pat. No. 3,505,068, US Pat.
It is described in detail in, for example, JP 60-14331.

The above-described silver halide emulsion may be either a surface latent image type which forms a latent image on the surface of a grain or an internal latent image type which forms a latent image on the inside of the grain. It may be of a type that forms a latent image inside.

The silver halide emulsion used in the present invention contains a cadmium salt at the stage of physical ripening or grain preparation.
You may add zinc salt, lead salt, thallium salt, iridium salt or its complex salt, rhodium salt or its complex salt, iron salt or its complex salt, etc.

The silver halide emulsion used in the present invention may be one in which soluble salts are removed or one in which soluble salts are not removed. As a method for removing the soluble salts, there are a Nudell water washing method, a flocculation sedimentation method and the like. As a preferred method, for example, a method using an aromatic hydrocarbon aldehyde resin containing a sulfo group described in JP-B-35-16086, JP Patent Publication
Aggregating polymer agents described in JP-A-2-301744, exemplified G3 and G
8 and the like.

Various photographic additives can be added to the emulsion according to the present invention during the physical ripening or the chemical ripening or in the steps before and after the ripening. Examples of these additives include Research Disclosure No. 17643.
(December 1978) (RD-17643), and No. 18716 (197).
November 9) (RD-18716), No. 308119 (December 1989)
Mon) (RD-308119). Table 1 shows the types of compounds shown in these three Research Disclosures and their locations.

The supports which can be used in the silver halide photographic light-sensitive material of the present invention also include the above-mentioned RD-17643 and R.
It is described in D-308119, and its description part is shown in Table 1.

[0055]

[Table 1] A plastic film or the like is suitable as a support for the silver halide photographic light-sensitive material of the present invention. The surface of these supports may be subjected to corona discharge treatment, ultraviolet irradiation treatment or the like, or may be provided with an undercoat layer in order to improve the adhesion of the coating layer.

[0056]

EXAMPLES Examples of the present invention will be described below. However, as a matter of course, the present invention is not limited to the examples described below.

Example 1 << Preparation of Regular Emulsion >><Preparation of Seed Emulsion> While controlling at 60 ° C., pAg = 8 and pH = 2.0, silver iodide having an average grain size of 0.3 μm by the daffle jet method.
Monodisperse cubic grains of silver iodobromide containing 2 mol% were prepared.

The resulting reaction solution was desalted at 40 ° C. with an aqueous solution of Demol N manufactured by Kao Atlas and an aqueous solution of magnesium sulfate, and then an aqueous solution of gelatin was added thereto and redispersed to obtain a seed emulsion. <Preparation of Monodisperse Silver Iodobromide Emulsions (A) and (B)> Using the above seed emulsion, grains were grown as follows, desalted, and a gelatin solution was added to redisperse the grains to form rounded vertices. Tinged 14
A silver halide emulsion (A) which is a faced body and has an average silver iodide content of 1.5 mol, an average grain size of 0.55 μm, and a coefficient of variation (δ / r) of 0.17 and rounded vertices. A silver halide emulsion (B) having a tetradecahedral structure having an average silver iodide content of 1.5 mol%, an average grain size of 0.55 μm and a coefficient of variation (δ / r) of 0.16 was prepared. . The coefficient of variation (δ / r) is based on the method described in JP-A-60-162244. (The same shall apply hereinafter.) Grain growth The seed emulsion was dispersed in a gelatin aqueous solution kept at 40 ° C, and the pH was adjusted to 9.7 with aqueous ammonia and acetic acid.

An aqueous solution of ammoniacal silver nitrate and an aqueous solution containing fine particles of potassium bromide and silver iodide were added to this solution by the double jet method. During addition, pAg 7.3, pH
Controlled to 9.7, a layer having a silver iodide content of 35 mol% was formed.
Next, an ammoniacal silver nitrate aqueous solution and a potassium bromide aqueous solution were added by the double jet method. PA up to 95% of target particle size
The g was kept at 9.0 and the pH was continuously changed from 9.0 to 8.0. After that, pAg was adjusted to 11.0 and grown to a target particle size while keeping pH at 8.0. Subsequently, the pH was lowered to 6.0 with acetic acid, desalting was performed using an aqueous solution of Demol N and an aqueous solution of magnesium sulfate manufactured by Kao Atlas, and a gelatin solution was added to redisperse. <Preparation of regular color-sensitive high-sensitivity emulsions R-1 to R-3>
Chloroauric acid, sodium thiosulfate and ammonium thiocyanate were added to each of the obtained monodisperse silver iodobromide emulsions (A) and (B), and chemical ripening was carried out at 55 ° C. 4-hydroxy-6-methyl-1,3,3a, 7 at the end of aging
-Tetrazaindene 3 x 10 per mol of silver halide
^-2 mol was added and dispersed in an aqueous solution containing 70 g of gelatin.

The above two types of ripened emulsions (A) and (B) were mixed in the proportions shown in Table 2 to prepare regular color-sensitive high-sensitivity emulsions R-1 to R-3. These emulsions have grains having high silver iodide at the center and silver iodobromide at the periphery. << Preparation of Ortho Emulsion >><Preparation of Silver Iodobromide Emulsion (C)> Tabular grains were formed according to the preparation of Emulsion II described in JP-A-4-158353.
However, the amount of potassium iodide to be added is reduced to 0.2 mol% of silver iodide so that a silver iodobromide emulsion having 99.8 mol% of silver bromide can be obtained, and the average grain size is 1.25 μm.
A silver iodobromide emulsion (C) having m, an average grain thickness of 0.28 μm, a coefficient of variation of 0.16, and grains C in which 90% or more of the total projected area is occupied by tabular grains having an aspect ratio of 3 or more is obtained. The preparation conditions were changed so that <Preparation of Ortho Emulsion O-1> Pure water was added to the obtained emulsion (C) so that the volume per mol of silver halide was 500 ml, and then the mixture was heated to 50 ° C. to obtain spectral sensitizing dyes 5 and 5. ′-
Anhydrous of dichloro-9-ethyl-3,3'-di- (3-sulfopropyl) oxacarbocyanine sodium salt and 5,5'-di- (butoxycarbonyl) -1,1-diethyl-3,3 ' -Di- (4-sulfobutyl) benzimidazolocarbocyanine sodium salt anhydride 150: 1
In a weight ratio of
It was added to 450 mg.

After 10 minutes, 4 × 10 ⁻³ mol of ammonium thiocyanate was added per mol of silver, and 7 × 10 ⁻⁶ mol of the following selenium compound A was added, and then an appropriate amount of chloroauric acid and thiourea were added. Was added for chemical ripening. At this time, the pH is 6.1
5. The silver potential was 80 mV. 15 minutes before the completion of chemical ripening (70 minutes after the start of chemical ripening), 250 mg of potassium iodide was added per mol of silver, and 5 minutes later, 10% (wt / vol) acetic acid was added to adjust the pH to 5.6. Decrease and maintain the pH for 5 minutes, then add 0.5% (wt / vol) potassium hydroxide solution to adjust the pH.
To 6.15, 4-hydroxy-6-methyl-1,
2500 mg of 3,3a, 7-tetrazaindene was added and the chemical ripening was completed to obtain Ortho Emulsion O-1.

[0062]

[Chemical 1]

[0063]

[Table 2] << Preparation of sample >><Preparation of emulsion coating solution> Emulsion R- thus obtained
The following emulsion additives were added to 1 to R-3 and 0-1 and the dyes shown in Table 3 were added at the addition amounts shown in Table 3 to prepare emulsion coating solutions used for the respective samples.

After the emulsion coating solution was prepared, the pH was adjusted to 6.20 and the silver potential was adjusted to 80 mV (35 ° C.) using sodium carbonate and potassium bromide solution. The addition amount of the additive for emulsion is shown in the amount per mol of silver halide.

1,1-Dimethylol-1-bromo-1-nitromethane 70 mg t-butyl-catechol 10 mg Polyvinylpyrrolidone (molecular weight 10,000) 1.2 g Styrene-maleic anhydride copolymer 2.5 g Nitrophenyl-triphenylphosphonium chloride 50 mg 1 , 3-Dihydroxybenzene-4-ammonium sulfonate 4 g 2-mercaptobenzimidazole-5-sodium sulfonate 1.5 mg 1-phenyl-5-mercaptotetrazole 50 mg trimethylolpropane 10 mg C ₄ H ₉ OCH ₂ CH (OH) CH ₂ N (CH ₂ COOH) ₂ lg Latex (average particle size 0.15 μm) 3.6 g (Copolymer of isononyl acrylate and cyclohexyl acrylate) Ludox AM (DuPont colloidal silica) 30 g

[0066]

[Chemical 2] <Preparation of Samples 1-18> Thickness colored in blue with a concentration of 0.15
A copolymer obtained by diluting a 175 μm polyethylene terephthalate film base on a glycidyl methacrylate 50 wt%, methyl acrylate 10 wt%, butyl methacrylate 40 wt% copolymer so as to have a concentration of 10 wt% An undercoat liquid consisting of an aqueous dispersion was applied.

[0067]

[Chemical 3] The spectral absorption curves of the above dyes A and B are shown in FIG. The absorption maximum wavelength of dye A is 555 nm, and the absorption maximum wavelength of dye B is 4
It is 50 nm.

Then, a protective layer solution prepared by using the emulsion coating solution shown in Table 3 and the following additives was applied to both sides of the support coated with an undercoat layer every minute by using two slide hopper type coaters. Simultaneous coating was performed at a speed of 85 m and dried for 2 minutes and 20 seconds to obtain a sample.

The coating amount of the emulsion coating solution was 1.7 g / m ² as the gelatin amount on each side, and the coating amount of the protective layer solution was 0.85 g / m ² on each side. The amount of silver halide (silver conversion amount) on each surface was as shown in Table 3. Additives for protective layer liquid The amount of addition is shown per liter of coating liquid.

[0070]

[Chemical 4] FIG. 2 shows the front side spectral absorption curve (R-2) of sample No. 1 using emulsion R-2 on the front side and the front side spectral absorption curve of sample No. 3 using emulsion O-1 on the front side. An absorption curve (O-1) is shown. The spectral absorption curve (R-2) shows the color sensitivity of the emulsion R-2, and the spectral absorption curve (O-1) shows the emulsion O-.
1 shows the color sensitivity.

The following examinations were conducted on the obtained samples. << Sensitometry test >> As shown in Table 3, S on the front surface and back surface of the X-ray imaging cassette loaded with the sample.
RO-250 (ortho screen), SRO-125 (ortho screen), NR-160 (regular screen)
(All manufactured by Konica Corporation) were attached, and a sensitometry test was performed by a method of irradiating with X-rays.

X-rays were irradiated for 0.08 seconds at a tube voltage of 80 KVP and 20 mA, a sensitometric curve was created by the distance method, and sensitivity and gamma were determined. The sensitivity was determined by the reciprocal of the exposure amount required to obtain the density of 1.0 + fog, and the obtained results are shown in Table 3 as a relative value when the sample No. 1 is 100.

The developing process is carried out by the automatic developing machine SRX-5.
03 (manufactured by Konica Co., Ltd.) using a modified transport control system, SR-DF developer and fixer (both manufactured by Konica Co., Ltd.) were used for development processing, and the development temperature was 36 ° C.
The fixing temperature was 33 ° C. The washing water was supplied at 5 ° C./min at 18 ° C., and the whole treatment process was performed in 28 seconds. << MTF (sharpness) measurement >> As shown in Table 3, SRO-250 (intensifying screen for ortho), SRO-125 on the front surface and back surface of the X-ray imaging cassette loaded with the sample.
(Ortho intensifying screen), NR-160 (Regular intensifying screen) (both manufactured by Konica Corporation) were attached, and a tube voltage of 80
A rectangular wave chart was photographed by KVP and measured by the contrast method. The results obtained are shown in Table 3.

The development is performed by the automatic developing machine SRX-503.
(Konica Corporation) modified transport control system, SR-DF developer and fixer (both manufactured by Konica Corporation) were used for development, development temperature 36 ° C, fixing temperature 33 ° C. I went there. The washing water was supplied at 5 ° C./min at 18 ° C., and the whole treatment process was performed in 28 seconds.

The MTF is represented by the value of spatial frequency of 2.0 lines / mm, and the larger the value, the better the sharpness.

[0076]

[Table 3] From the above results, it is understood that the light-sensitive material of the present invention can obtain high sharpness while maintaining high sensitivity. Further, as shown in Sample Nos. 15 and 16, the light-sensitive material of the present invention can obtain high sharpness even when combined with fluorescent intensifying screens having the same light emission characteristics.

[0077]

INDUSTRIAL APPLICABILITY The silver halide photographic light-sensitive material for X-ray photography of the present invention can provide an image with high sensitivity and high sharpness, and even if two fluorescent intensifying screens having the same emission wavelength are used. Highly sharp images can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing spectral absorption curves of dye A and dye B.

FIG. 2 is a diagram showing spectral absorption curves of emulsion R-2 and emulsion O-1.

Claims (3)

[Claims] 1. A photographic light-sensitive material in which at least one light-sensitive silver halide emulsion layer is provided on both surfaces (A) and (B) of a transparent support, and one surface (A) and the other surface (B) ) And differ from each other in the color sensitivity of the light-sensitive silver halide emulsion layer, and at least one of the light-sensitive silver halide emulsion layer on the other surface (B) or a layer between the emulsion layer and the support. A silver halide photographic light-sensitive material, characterized in that it contains a dye which effectively absorbs light in the wavelength region of maximum light sensitivity to which the light-sensitive silver halide emulsion layer on one side (A) is exposed. 2. The silver halide photographic light-sensitive material according to claim 1, wherein either the photosensitive silver halide emulsion layer on one side (A) or the photosensitive silver halide emulsion layer on the other side (B) is used. A silver halide photographic light-sensitive material characterized in that one is a high-sensitivity layer and the other is a low-sensitivity layer. 3. The silver halide photographic light-sensitive material according to claim 1 or 2, further comprising at least a light-sensitive silver halide emulsion layer on one side (A) or a layer between the emulsion layer and a support. A silver halide photographic light-sensitive material comprising one layer containing a dye which effectively absorbs light in the wavelength region of maximum light sensitivity to which the light-sensitive silver halide emulsion layer on the other side (B) is exposed.