JP3479603B2 - Radiographic intensifying screen - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiographic intensifying screen used for taking a radiographic image.

[0002]

2. Description of the Related Art In radiography such as X-ray photography used for medical diagnosis, halogenation is performed on both sides of a transparent support in order to effectively use radiation such as X-rays to obtain a high-sensitivity and high-quality image. An image is formed by arranging two radiographic intensifying screens on both sides of a silver halide photographic light-sensitive material (double-sided light-sensitive material) coated with a silver emulsion and exposing the object to X-rays that have passed through. In such a double-sided system, the light emitted by the intensifying screen is transmitted through one emulsion layer of the adjacent light-sensitive material and reaches the emulsion layer on the opposite side of the support to sensitize the silver halide, so-called crossover. This phenomenon is a major cause of deterioration in image sharpness. In order to shield this crossover light, various studies have been conducted on both a light-sensitive material (hereinafter also simply referred to as a light-sensitive material) and an intensifying screen (hereinafter also simply referred to as a screen).

As a method of blocking crossover light with an intensifying screen, for example, WO93-01521, EP650089 and EP592724.
As described in the publication, it is proposed to cut the crossover by bringing the emission wavelength of the phosphor into the ultraviolet region. Further, regarding a screen using a terbium-activated gadolinium oxysulfide (Gd ₂ O ₂ S: Tb) -based phosphor, proposals have been made to reduce crossover as follows. For example, JP-A-61-151
Japanese Patent No. 534 describes a screen in which the ratio of green light emission is higher than that of blue light emission by adjusting the composition of the phosphor and adding an absorbing dye. JP-A-62-222200 and JP-A-4-155297 describe a screen having improved sharpness by imparting a distribution to the coloring of the phosphor layer. RD83-22709
And RD82-218041 propose to improve the sharpness by adding a yellow dye or an absorbing dye. Japanese Patent Publication No. 58-2640 proposes to improve the sharpness by attaching an absorbing pigment to the surface of the phosphor. US Patent No. 436294
No. 4 specification proposes that a surface protective layer absorbs a part of the emitted light. As a screen with less crossover, a screen in which the phosphor layer is dyed yellow (Eastman Kodak Company, Lanex Medi
um) is actually commercially available. However, in the case where such an absorbing dye or pigment is used, it is inevitable that addition of the absorbing dye or pigment lowers the sensitivity.

Regarding an intensifying screen containing a fluorescent dye or a fluorescent pigment, EP 0595089 describes that the sensitivity is increased in combination with an ultraviolet emitting phosphor. DE 2807398 gazette and DE314381
No. 0, gazette describes a screen using a fine particle fluorescent pigment. However, neither was a screen using a Gd ₂ O ₂ S: Tb-based phosphor, nor was it a screen that improved crossover.

[0005]

There is a strong demand from the market for a radiographic system which produces a radiographic image having high sensitivity and high sharpness, and further development of a radiographic intensifying screen for realizing the system. Is awaited. In the radiographic image forming method, as a radiographic intensifying screen showing high sensitivity, a radiographic intensifying screen using a rare earth-based phosphor is known, but in a radiographic image forming system using this type of radiographic intensifying screen. The above-mentioned improvements cannot sufficiently reduce the crossover, so that the sharpness needs to be further improved. Therefore, it is an object of the present invention to provide a radiographic intensifying screen which provides a radiographic image with excellent sensitivity and sharpness.

[0006]

The present inventors have conducted extensive research on terbium-activated gadolinium oxysulfide phosphor as a phosphor for radiation intensifying screens. The peak wavelength of the main emission of this phosphor is about 545 nm, and the silver halide photographic light-sensitive material color-sensitized to have high sensitivity to the wavelength has low sensitivity in the visible region of 500 nm or less. As a result of paying attention to the research, the radiation intensifying screen has a wavelength of 500 among the light emitted from the phosphor.
By absorbing the emitted light of nm or less, by containing a fluorescent dye or fluorescent pigment that emits light in the vicinity of the peak wavelength of the main emission of the phosphor (that is, a region where the silver halide photographic light-sensitive material exhibits high sensitivity), It has been found that reduction of crossover and increase of sensitivity are realized at the same time. Further, it has been found that crossover can be more efficiently reduced by incorporating a dye capable of selectively absorbing light in the vicinity of the peak wavelength of the main emission of the phosphor into the light-sensitive material. That is, as a result of the research conducted by the present inventor, by introducing a fluorescent dye or a fluorescent pigment into a radiographic intensifying screen, the emitted light on the short wavelength side irradiated to the photosensitive material from the phosphor that causes crossover is effective. At the same time, the emission light from the intensifying screen can be increased in the wavelength region in which the photosensitive material exhibits high sensitivity by the conversion (shift) of the emission wavelength by the fluorescent dye or fluorescent pigment. That is, the study by the present inventor has revealed that it becomes possible to form a radiographic image excellent in both sensitivity and sharpness by using the above-described radiographic intensifying screen.

[0007] The present invention provides a radiographic intensifying screen having at least one layer of the phosphor layer on a support, the fluorescent body layer is made of terbium activated gadolinium oxysulfide phosphor, and intensifying screen, the phosphor sales of light-emitting light
Has a peak in the wavelength region shorter than 500 nm.
Light that absorbs at least 1 wavelength greater than the peak wavelength
A radiographic intensifying screen is characterized by containing a fluorescent dye or a fluorescent pigment that emits light having an emission peak in the wavelength range of 490 to 600 nm on the long wavelength side of 0 nm . In the present invention, a fluorescent dye or fluorescent
The pigment has a light absorption peak in the wavelength range shorter than 500 nm.
It is preferable to have

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the radiation intensifying screen of the present invention will be described below. (1) The fluorescent dye or fluorescent pigment has a light absorption peak in a wavelength region shorter than 500 nm and has a wavelength of 450 to 6
It has an emission peak in the wavelength region of 00 nm, and the wavelength of the emission peak is at least 10 nm longer than the wavelength of the light absorption peak. (2) 400-490 nm fluorescent dye or fluorescent pigment
Has a light absorption peak in the wavelength region of
It has an emission peak in the wavelength region of 0 nm. (3) The full width at half maximum of light emitted by the fluorescent dye or fluorescent pigment is 100 nm or less. (4) The fluorescent dye or fluorescent pigment is a carbocyanine dye, a xanthene dye, a triarylmethane dye, a coumarin dye, a phthalimide compound, a naphthalimide compound,
A diketopyrrolopyrrole compound and / or a perylene compound. (5) The fluorescent dye or the fluorescent pigment is a phosphor layer (or,
It is contained in the surface protective layer). (6) Terbium activation The activation amount of terbium in the gadolinium oxysulfide phosphor is 0.001 to 0.02 mol per mol of gadolinium.

The radiation intensifying screen of the present invention will be described in detail below. The radiation intensifying screen of the present invention comprises, as a basic structure, a support and one or more phosphor layers formed on the support. The intensifying screen may have a structure similar to that of a known radiation intensifying screen. For example, a light reflecting layer or a light absorbing layer may be provided between the support and the phosphor layer, or the phosphor layer. It is preferable to provide a surface protective layer on the above. The fluorescent dye or fluorescent pigment, which is a characteristic requirement of the present invention, may be contained in any layer of the intensifying screen, but in order to exert its effect effectively, it is contained in the phosphor layer or the surface protective layer. The phosphor layer is preferable, and the phosphor layer is particularly preferable.

The phosphor used in the radiation intensifying screen of the present invention is a terbium-activated gadolinium oxysulfide phosphor represented by the following basic composition formula (I). In addition,
The phosphor represented by the basic composition formula (I) is also added with an additive of less than about 10% for improving its characteristics, or silica, alumina, etc. for modifying the surface. include. Part of Gd (less than 50 atomic%, preferably less than 30 atomic%, particularly less than 10 atomic%)
Can be replaced by La, Lu and / or Y. Basic composition formula (I): Gd ₂ O ₂ S: Tb Here, the activator Tb is to be replaced with Gd. T
The substituting ratio of b is arbitrary, but the molar ratio is 0.00
It is preferably from 02 to 0.2, more preferably from 0.0005 to 0.05, and particularly preferably 0.0.
It is 01 to 0.02.

FIG. 2 shows the Gd ₂ O ₂ S: T used in the present invention.
An example of the emission spectrum of the b phosphor by X-ray excitation is shown (W tube, excited by 40 kVp X-ray). As is clear from FIG. 2, the main emission peak of the Gd ₂ O ₂ S: Tb phosphor is at about 545 nm, but other than that, it is 380 to 500.
Multiple emission peaks are shown over nm.

The fluorescent dye or fluorescent pigment, which is a characteristic requirement of the present invention, is a substance which absorbs a part of the emitted light of the above-mentioned phosphor and exhibits an emission peak in the wavelength range of 490 to 600 nm. That is, it is a fluorescent dye or pigment that absorbs emitted light other than around 545 nm and emits light around 545 nm. The peak wavelength of the light emission of the fluorescent dye or fluorescent pigment is set according to the spectral sensitivity of the silver halide photographic light-sensitive material. Specifically, it is at least 500 nm.
A fluorescent dye or fluorescent pigment that absorbs light of the following wavelengths and exhibits a peak of light emission in the wavelength range of 490 to 600 nm is preferable. However, the peak wavelength of the emission spectrum is preferably 10 nm or more, more preferably 20 nm or more, on the longer wavelength side than the peak wavelength of the absorption spectrum. The emission peak is more preferably 500 to 570 n.
The range is m. The full width at half maximum of the emitted light is preferably 100 nm or less, more preferably 80 nm or less,
Particularly preferably, it is 70 nm or less. Such conversion of the emission wavelength makes it possible to achieve an improvement in sensitivity when combined with a light-sensitive material and, at the same time, to significantly reduce the crossover by reducing the blue emission light.

In the present invention, the fluorescent dye or fluorescent pigment preferably has an emission quantum yield of 20% or more. Here, the quantum yield is: quantum yield (%) = (number of emitted photons / number of absorbed photons) × 1
It is represented by 00. The higher the quantum yield, the better
It is preferably at least 40%, more preferably at least 60%.

The fluorescent dye or fluorescent pigment may be an inorganic compound fluorescent substance or an organic compound and is not particularly limited. However, when it is contained in the phosphor layer, the particle size of the phosphor dye or pigment is preferably small in order not to impair the filling rate of the phosphor, and is usually in the range of 0 to 2 μm, preferably 0. ˜1 μm range. It is also preferable that the intensifying screen does not exist in a solid state. Therefore, as such a compound having a small particle size and a high quantum yield, an organic compound fluorescent dye or fluorescent pigment is preferably used.

As the fluorescent dye or fluorescent pigment, known dyes or pigments, for example, "Handbook of Dyes" (315 to 11)
The dyes or pigments described in P. 09, Organic Synthesis Society, 1970, and "Coloring Materials Handbook" (pages 225 to 417, Coloring Materials Society, 1989) can be used. In particular, the dyes described in "Laser Soybean" (Mitsuo Maeda, Academic Press, 1984) are preferable. Specifically, the carbocyanine dyes shown in Table 4 on pages 26 to 29, the phthalocyanine dyes shown in Table 11 on pages 74 to 75, and the phthalocyanine dyes shown on page 76 to 105
Xanthene dyes listed in Tables, triarylmethane dyes listed in Table 13 on page 106, 14th on pages 107 to 110
Acridine dyes listed in the table, pp. 137-149, 18th
Fused ring compounds shown in the table, coumarin and azacoumarin dyes shown in Table 23 on pages 189 to 238, 239 to 24
Quinolone and azaquinolone dyes listed in Table 25 on page 6, oxazole and benzoxazole compounds listed in Table 26 on pages 247 to 261, furan and benzofuran compounds listed in Table 29 on pages 273 to 275, 276
Pyrazoline compounds shown in Table 30 on page 27, Phthalimide and naphthalimide compounds shown in Table 31 on page 277, Peteridine compounds shown in Table 32 on page 282, 2
Pyrylium, phospholine, borazidinium, pyridine compounds and the like described in Table 33 on page 83 can be mentioned. Further, diketopyrrolopyrrole compounds described in JP-A-58-210084, and JP-A-7-
Examples thereof include perylene compounds described in Japanese Patent No. 188178.

The fluorescent dye or pigment may have an absorption spectrum maximum (peak) wavelength in the range of 350 to 500 nm and a fluorescence (emission) spectrum maximum (peak) wavelength in the range of 500 to 600 nm. desirable. However, the peak wavelength of the emission spectrum is preferably at least 10 nm (preferably at least 20 nm) longer than the peak wavelength of the absorption spectrum. Further, the maximum wavelength of the absorption spectrum is 400 to 4
It is also preferable that it is in the range of 90 nm and the maximum wavelength of the fluorescence spectrum is in the range of 500 to 570 nm.
And among the above compounds, such fluorescent dyes or pigments are carbocyanine dyes, xanthene dyes, triarylmethane dyes, acridine dyes, coumarin and azacoumarin dyes, phthalimide and naphthalimide compounds,
Pyrylium compounds, diketopyrrolopyrrole compounds, and perylene compounds. Particularly preferably, the maximum wavelength of the fluorescence spectrum is in the range of 500 to 555 nm, and such a fluorescent dye or pigment is a carbocyanine dye, a xanthene dye, a triarylmethane dye, a coumarin dye,
Phthalimide and naphthalimide compounds, diketopyrrolopyrrole compounds, and perylene compounds.

It is preferable that these fluorescent dyes or fluorescent pigments have no afterglow. Those having a fluorescence lifetime of 10 ^-2 seconds or less are preferably used. Further, these fluorescent dyes or fluorescent pigments are required to be resistant to decomposition with storage, light or heat. Specific examples of the fluorescent dye and fluorescent pigment used in the present invention are shown below, but the present invention is not limited thereto.

[0018]

[Chemical 1]

[0019]

[Chemical 2]

[0020]

[Chemical 3]

[0021]

[Chemical 4]

[0022]

[Chemical 5]

[0023]

[Chemical 6]

[0024]

[Chemical 7]

[0025]

[Chemical 8]

[0026]

[Chemical 9]

[0027]

[Chemical 10]

[0028]

[Chemical 11]

[0029]

[Chemical 12]

[0030]

[Chemical 13]

[0031]

[Chemical 14]

[0032]

[Chemical 15]

The phosphor layer is prepared by dispersing the particles of the phosphor and the particles of the above-mentioned phosphor dye or pigment, if the particles are contained, in an organic solvent solution containing a binder resin to prepare a dispersion liquid. It can be formed by directly coating the dispersion on a support (or an undercoat layer when a subbing layer such as a light reflecting layer is provided on the support) and drying. Alternatively, after applying this dispersion liquid to a separately prepared temporary support and drying it to form a phosphor sheet, the phosphor sheet is peeled off from the temporary support and attached to the support using an adhesive. May be.

The particle size of the phosphor particles is not particularly limited and is usually in the range of about 1 to 15 μm, preferably about 2 to 10 μm.
It is in the range of μm. The volume filling factor of the phosphor particles in the phosphor layer is preferably higher, usually in the range of 60 to 85%, preferably in the range of 65 to 80%, particularly preferably in the range of 68 to 75%. is there. (The ratio of phosphor particles in the phosphor layer is usually 80% by weight or more,
Preferably 90% by weight or more, particularly preferably 95% by weight
That is all. The content of the fluorescent dye or pigment is usually in the range of 0.1 to 5000 mg, preferably 1 to 1000 mg, and particularly preferably 5 to 500 mg per 1 kg of the phosphor. The binder resin, the organic solvent and various additives that can be optionally used for forming the phosphor layer are described in various publicly known documents. The thickness of the phosphor layer can be arbitrarily set according to the target sensitivity, but is preferably in the range of 70 to 150 μm for the front side screen and 80 to 400 μm for the back side screen.
Is the range. The X-ray absorption rate of the phosphor layer is determined by the coating amount of the phosphor particles.

The phosphor layer may have a single layer, or may have two or more layers. The number of layers is preferably one to three, and more preferably one or two.
For example, layers composed of phosphor particles having a relatively narrow particle size distribution and different particle sizes may be laminated, and in that case, the particles closer to the support may have a smaller particle size. The phosphor layer may be formed by mixing phosphor particles having different particle diameters, or from page 3, left column, line 3 to page 4, left column, line 39 of JP-B-55-33560. As described, the phosphor layer may have a structure in which the particle size distribution of the phosphor particles is inclined. Usually, the variation coefficient of the particle size distribution of the Gd ₂ O ₂ S: Tb phosphor is in the range of 30 to 50%, but monodisperse phosphor particles having the variation coefficient of 30% or less can also be preferably used.

The support may be appropriately selected from various supports used for known radiation intensifying screens according to the purpose and used. For example, a polymer film containing a white pigment such as titanium dioxide or a polymer film containing a black pigment such as carbon black is preferably used.

An undercoat layer such as a light reflecting layer containing a light reflecting material may be provided on the surface of the support (the surface on the side where the phosphor layer is provided). The light reflection layer is a layer made of a polymer binder containing a white pigment such as titanium dioxide. For example,
As described in Examples 1 and 2 of JP-A-9-21899, a light-reflecting layer containing 10 to 75% by volume filling rate of titanium dioxide having an average particle size of 0.1 to 0.5 μm. Is preferably provided in a thickness range of 10 to 100 μm.

A surface protective layer is preferably provided on the surface of the phosphor layer. As the surface protective layer, the light scattering length measured at the main emission wavelength of the phosphor is preferably in the range of 5 to 80 μm, more preferably in the range of 10 to 70 μm, and particularly preferably in the range of 10 to 60 μm. Is. Here, the light scattering length represents the average distance that light travels straight before being scattered once, and the shorter the scattering length, the higher the light scattering property. The light absorption length, which represents the mean free distance until light is absorbed, is arbitrary, but from the viewpoint of screen sensitivity, it is preferable that the surface protective layer does not absorb light, because desensitization is less. In order to make up for the lack of scattering, it is possible to give a very small degree of absorption. Absorption length is preferably 800μ
m or more, and particularly preferably 1200 μm or more. The light scattering length and the light absorption length were measured by the following method using the measured values of Kubelk-Munk.
It can be calculated by a calculation formula based on the theory of a-Munk).

First, three or more film samples having the same composition as the surface protective layer to be measured and having different layer thicknesses are prepared. Next, the thickness of each film sample (μm)
And diffuse transmittance (%) are measured. The diffuse transmittance can be measured by an apparatus in which an integrating sphere is attached to an ordinary spectrophotometer. In the measurement in the present invention, a self-recording spectrophotometer (U-3210, manufactured by Hitachi, Ltd.) with a 150φ integrating sphere (150-0901) is used. The measurement wavelength needs to match the peak wavelength of the main emission of the phosphor in the phosphor layer to which the surface protection layer is attached. Then, the thickness (μm) of the film and the measured value of the diffuse transmittance (%) are introduced into the following formula (A) derived from the Kubelka-Munk theoretical formula. The formula (A) is, for example, “Phosphor Handbook” (edited by Phosphor Society), Ohmsha, Ltd., 198
It can be easily derived from the equations 5.1.12 to 5.1.15 on page 403 under the boundary condition of diffuse transmittance T (%).

[0040]

## EQU1 ## T / 100 = 4β / [(1 + β) ² · exp (αd) − (1-β) ² · exp (−αd)] (A)

However, T is the diffuse transmittance (%), d is the film thickness (μm), and α and β are defined by the following equations, respectively.

[0042]

[Formula 2] α = [K · (K + 2S)] ^1/2 β = [K / (K + 2S)] ^1/2

T measured on three or more films
Introducing (diffuse transmittance:%) and d (film thickness: μm) into the above formula (A), respectively, K satisfying the formula (A)
And S are calculated. The scattering length (μm) is defined by 1 / S and the absorption length (μm) is defined by 1 / K.

The surface protective layer preferably has a structure in which light scattering particles are dispersed and contained in a resin material. The light-refractive index of the light-scattering particles is usually 1.6 or more, preferably 1.9 or more. The particle diameter of the light-scattering particles is usually in the range of 0.1 to 1.0 μm. Examples of such light-scattering particles include magnesium oxide, zinc oxide, zinc sulfide, titanium oxide, niobium oxide, barium sulfate, lead carbonate, silicon oxide, polymethylmethacrylate,
Fine particles of styrene and melamine may be mentioned. Among these, preferable light-scattering particles having a particularly high refractive index are fine particles of zinc oxide, zinc sulfide, titanium oxide and lead carbonate, and particularly preferably titanium oxide (particularly anatase type).

The resin material used for forming the surface protective layer is not particularly limited, but polyethylene terephthalate, polyethylene naphthalate, polyamide, aramid, fluororesin, polyester and the like can be preferably used. The surface protective layer is prepared by dispersing the above light-scattering particles in an organic solvent solution containing a resin material (binder resin) to prepare a dispersion liquid, and then disposing the dispersion liquid on the phosphor layer (or any auxiliary layer). It can be formed by directly applying (via a layer) and drying. Alternatively, a separately formed protective layer sheet may be attached to the phosphor layer using an adhesive. The thickness of the surface protective layer is usually 2 to 12 μm.
And preferably in the range of 3.5 to 10 μm. The fluorescent dye or pigment may be contained in the surface protective layer by adding particles of the fluorescent dye or fluorescent pigment to this dispersion.

Further, regarding the preferable method for producing the radiation intensifying screen and the materials used therefor, for example, JP-A No. 9-21899, page 6, left column, line 47 to line 8.
Page left column, line 5, line 2 right column, line 17 to page 3 left column, line 33 of JP-A-6-347598, and the same publication No. 3
There is detailed description from page 42, left column, line 42 to page 4, left column, line 22, which can be referred to.

Next, the silver halide photographic light-sensitive material which can be advantageously used in combination with the radiation intensifying screen of the present invention will be described in detail. The silver halide photographic light-sensitive material has a crossover of 10% or less when radiation exposure is performed in combination with the intensifying screen of the present invention. Particularly, those having a crossover of 8% or less are preferable. Here, the crossover is a value obtained as follows.

First, one intensifying screen is prepared, a photosensitive material having emulsion layers on both sides is placed in contact with the front side of the screen, and a black paper is placed in contact with the front side of the sensitive material. Then, exposure is performed by changing the X-ray irradiation amount by changing the distance between the focal spot of the X-ray generator and the screen. The exposed light-sensitive material is subjected to development processing, and this is divided into two parts, and the emulsion layer on the side in contact with the screen is peeled from one side and the emulsion layer on the opposite side is peeled from the other side. Then, the density of each emulsion layer with respect to each exposure dose is plotted on a graph to prepare a characteristic curve of each emulsion layer.
Sensitivity difference ΔlogE between the two in the straight line part of each characteristic curve
The crossover (%) can be calculated by obtaining the average value of and applying it to the following formula. Crossover (%) = 100 / [antilog (Δ
logE) +1]

In order to reduce the crossover of the light-sensitive material to 10% or less, an absorption peak is shown in the wavelength range of 500 to 600 nm and an absorption coefficient of 4 at a wavelength of 550 nm.
It is preferable that the light-sensitive material contains a dye having a double absorption coefficient or more at a wavelength of 50 nm. More preferably, the dye has an absorption coefficient of 3 times or more. For example, normal G
In the screen using the d ₂ O ₂ S: Tb phosphor, in order to sufficiently reduce the crossover, not only in the vicinity of the peak wavelength of the main emission (about 545 nm) but also in the range of 380 to 5
It is necessary to add a dye capable of absorbing emitted light over a wide range of 70 nm, but by combining it with the screen of the present invention, a dye having a small absorption coefficient for blue light having a short wavelength of 500 nm or less is sufficient. The crossover can be reduced. On the contrary, by using the dye as described above, it becomes possible to increase the absorption coefficient for the light having the wavelength of 500 to 600 nm, the coating amount of the dye can be reduced, and at the same time, the crossover can be efficiently reduced. .

The method of incorporating a dye having a relatively sharp absorption peak in the wavelength range of 500 to 600 nm into the light-sensitive material is not particularly limited, but it is disclosed in, for example, JP-A No. 2/1999.
As described in JP-A-29641, a method of adsorbing a dye (dye) on silver halide microcrystals to give a sharp absorption peak and coating the lower layer, and a transparent inorganic compound such as SiO ₂ or mica. A method of adsorbing a dye to give a sharp absorption peak and adding it to a light-sensitive material can be preferably used. Particularly preferred is a method of fixing a decolorizable dye in the form of solid fine particles in the layer as described in JP-A-1-172828 and the like. The solid fine particles of the dye are contained in the photosensitive material as a solid fine particle dispersion. Here, the dye that can be decolorized in the development process shows sufficient light absorption before the process, but the absorbance in the visible part is 0.4 in the process of development, fixing and washing (including stabilization). What changes below, preferably changes to the range of 0-0.25.

The dye which can be decolorized during the developing process will be described in detail below. As the dye, a known dye or pigment, for example, "Handbook of Dyes" (pages 315 to 1109,
Organic Synthetic Chemistry Association, edited by 1970) or "Handbook of Color Material Engineering" (pages 225 to 417, edited by Color Material Association, published by 1989) may be used.
A dye represented by the following formula (FA) is preferably used.

Formula (FA): D- (X ₁ ) y _{1 In} formula (FA), D represents a group derived from a compound having a chromophore, and X ₁ represents a direct or divalent linking group for D. It represents a dissociative proton bonded via a group or a group having a dissociative proton, and X ₁ when a linking group is present includes a linking group. y ₁ is an integer of 1-7.

The compound having a chromophore from which D is derived is
It can be selected from many well-known dye compounds.

Examples of these dye compounds include oxonol dyes, merocyanine dyes, cyanine dyes, arylidene dyes, azomethine dyes, triphenylmethane dyes, azo dyes, anthraquinone dyes, and indoaniline dyes.

In the silver halide photographic light-sensitive material of the present invention, the compound represented by the formula (FA) has a dissociative proton or a group having a dissociative proton, which may have a linking group represented by X _1. It is non-dissociated when added to the formula (F
It has a property of making the compound of A) substantially water-insoluble, and has a property of dissociating to make the compound of formula (FA) substantially water-soluble in the step of developing the material (development process). Have. Examples of these groups include a carboxylic acid group, a sulfonamide group, an arylsulfamoyl group, a sulfonylcarbamoyl group, a carbonylsulfamoyl group, an enol group of an oxonol dye, and a phenolic hydroxyl group.

Among the compounds represented by the formula (FA), preferred examples include the following formulas (FA1), (FA2),
The compound represented by (FA3) may be mentioned.

General formula (FA1) A ₁ = L _1- (L ₂ = L ₃ ) _m -Q General formula (FA 2) A ₁ = L _1- (L ₂ = L ₃ ) _n -A ₂ General formula (FA3 ) A ₁ = (L ₁ −L ₂ ) _k = B ₁

In the formula, A ₁ and A ₂ each represent an acidic nucleus. B ₁ represents a basic nucleus. Q represents an aryl group or a heterocyclic group, and L ₁ , L ₂ and L ₃ each represent a methine group. m represents 0, 1, 2 and n and k represent 0, 1, 2, 3 respectively. However, formulas (FA1) to (FA
The compound 3) is selected from the group consisting of a carboxylic acid group, a sulfonamide group, an arylsulfamoyl group, a sulfonylcarbamoyl group, a carbonylsulfamoyl group, an enol group of an oxonol dye, and a phenolic hydroxyl group in one molecule. It has at least one group and has no other water-soluble group (eg, sulfonic acid group, phosphoric acid group).

The acidic nucleus represented by A ₁ and A ₂ is preferably a cyclic ketomethylene compound or a compound having a methylene group sandwiched by electron withdrawing groups.

Examples of cyclic ketomethylene compounds include:
2-pyrazolin-5-one, rhodanine, hydantoin,
Thiohydantoin, 2,4-oxazolidinedione, isoxazolone, barbituric acid, thiobarbituric acid, indandione, dioxopyrazolopyridine, hydroxypyridone, pyrazolidinedione, 2,5-dihydrofuran-2-one Can be mentioned. They are,
It may have a substituent.

The compound having a methylene group sandwiched by electron-withdrawing groups can be represented by Z ₁ CH ₂ Z ₂ . Here, Z ₁ and Z ₂ are -CN and -SO ₂ , respectively.
_{R 1, -COR 1, -COOR 2} , -CONHR 2, -
_{SO 2 NHR 2, -C [=} C (CN) 2] R 1, or -
Represents C [= C (CN) ₂ ] NHR ₁ . R ₁ represents an alkyl group, an aryl group, or a heterocyclic group, R ₂ represents a hydrogen atom, or a group represented by R ₁ , and these may each have a substituent.

Examples of the basic nucleus represented by B ₁ include pyridine, quinoline, indolenine, oxazole, imidazole, thiazole, benzoxazole, benzimidazole, benzothiazole, oxazoline, naphthoxazole and pyrrole. . Each of these may have a substituent.

Examples of the aryl group represented by Q include a phenyl group and a naphthyl group. Each of these may have a substituent. Examples of the heterocyclic group represented by Q include pyrrole, indole, furan, thiophene, imidazole, pyrazole, indolizine,
Mention may be made of quinoline, carbazole, phenothiazine, phenoxazine, indoline, thiazole, pyridine, pyridazine, thiadiazine, pyran, thiopyran, oxadiazole, benzoquinoline, thiazoazole, pyrrolothiazole, pyrrolopyridacine, tetrazole, oxazole, coumarin and coumarone. Any of these may have a substituent.

The methine group represented by L ₁ , L ₂ and L ₃ may have a substituent, and the substituents are linked to each other to form a 5- or 6-membered ring (for example, cyclopentene or cyclohexene). It may be formed.

The substituents which each of the above-mentioned groups may have are those capable of substantially dissolving the compounds of formula (FA) and formulas (FA1) to (FA3) in water of pH 5 to pH 7. If not, there is no particular limitation. For example, the following substituents can be mentioned.

Carboxylic acid groups, sulfonamide groups having 1 to 10 carbon atoms (for example, methane sulfonamide, benzene sulfonamide, butane sulfonamide, n-octane sulfonamide), sulfamoyl groups having 0 to 10 carbon atoms (for example, Substituted sulfamoyl, methylsulfamoyl, phenylsulfamoyl, butylsulfamoyl), a sulfonylcarbamoyl group having 2 to 10 carbon atoms (for example, methanesulfonylcarbamoyl, propanesulfonylcarbamoyl, benzenesulfonylcarbamoyl), and 1 to 10 carbon atoms. An acylsulfamoyl group (eg, acetylsulfamoyl, propionylsulfamoyl, pivaloylsulfamoyl, benzoylsulfamoyl), a chain or cyclic alkyl group having 1 to 8 carbon atoms (eg, methyl, ethyl , An isopropyl, butyl, hexyl, cyclopropyl, cyclopentyl, cyclohexyl, 2-hydroxyethyl, 4-carboxybutyl,
2-methoxyethyl, benzyl, phenethyl, 4-carboxybenzyl, 2-diethylaminoethyl), an alkenyl group having 2 to 8 carbon atoms (for example, vinyl, allyl), an alkoxy group having 1 to 8 carbon atoms (for example, methoxy, ethoxy). , Butoxy), halogen atoms (eg, F, Cl, B
r), an amino acid group having 0 to 10 carbon atoms (eg, unsubstituted amino, dimethylamino, diethylamino, carboxyethylamino), an alkoxycarbonyl group having 2 to 10 carbon atoms (eg, methoxycarbonyl), 1 to 10 carbon atoms
Amide group (eg, acetylamino, benzamide), a carbamoyl group having 1 to 10 carbon atoms (eg, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl), an aryl group having 6 to 10 carbon atoms (eg, phenyl, naphthyl, 4-carboxyphenyl, 3-carboxyphenyl, 3,5-dicarboxyphenyl, 4-methanesulfonamidophenyl, 4-butanesulfonamidophenyl), an aryloxy group having 6 to 10 carbon atoms (for example, phenoxy, 4-carboxy). Phenoxy, 3-methylphenoxy, naphthoxy), an alkylthio group having 1 to 8 carbon atoms (eg, methylthio, ethylthio, octylthio), an arylthio group having 6 to 10 carbon atoms (eg, phenylthio, naphthylthio), an alkylthio group having 1 to 10 carbon atoms. Acyl groups (eg acetyl Benzoyl, propanoyl),
Sulfonyl group having 1 to 10 carbon atoms (eg, methanesulfonyl, benzenesulfonyl), ureido group having 1 to 10 carbon atoms (eg, ureido, methylureido), 2 carbon atoms
A urethane group of 10 (for example, methoxycarbonylamino, ethoxycarbonylamino), a cyano group, a hydroxyl group,
Examples thereof include a nitro group and a heterocyclic group (for example, 5-carboxybenzoxazole ring, pyridine ring, sulfolane ring, pyrrole ring, pyrrolidine ring, morpholine ring, piperazine ring, pyrimidine ring, furan ring).

As the dye represented by formula (FA) used in the present invention, the dye described in JP-A-4-45436 is particularly preferably used.

Specific examples of the compounds represented by formula (FA) and formulas (FA1) to (FA3) used in the present invention are described below.

[0069]

[Chemical 16]

[0070]

[Chemical 17]

[0071]

[Chemical 18]

[0072]

[Chemical 19]

[0073]

[Chemical 20]

[0074]

[Chemical 21]

[0075]

[Chemical formula 22]

[0076]

[Chemical formula 23]

[0077]

[Chemical formula 24]

[0078]

[Chemical 25]

Other specific examples of the formula (FA1) include (II-2) to (II-) described in JP-A-7-152112.
24) as a specific example of (FA2) described in (II)
Specific examples of I-5) to (III-18) and (FA3) include (IV-2) to (IV-7) described in the publication.

In addition, as the dyes usable in the present invention, cyanine dyes, pyrylium dyes and aminium dyes described in JP-A-3-138640 can be used as dyes dispersed in solid fine particles which can be decolorized during development processing. Is mentioned.

The dye used in the present invention is an international patent WO88.
/ 04794, European Patent (EP) 0274
723A1 publication, 276566 publication, and 2994 publication.
35, JP-A-52-92716, and 55-
No. 155350, No. 55-155351, No. 61-205934, No. 48-68623, US Pat. No. 2,527,583, No. 34868.
No. 97, No. 3746539, No. 3933
No. 798, No. 4130429, No. 404
0841 specification, JP-A-2-282244, JP-A-3-7931, JP-A-3-167546, JP-A-1-266536, JP-A-3-136038, JP-A-3-226736, and JP-A-3-266546. JP-A-3-138640, JP-A-3-211542, and Japanese Patent Application No. 6-2279.
No. 82, No. 6-227983, No. 6-279.
No. 297, No. 7-54026, No. 7-101.
968, 7-135118, and JP-A-2-
282244, Japanese Patent Laid-Open No. 7-113072,
It can be synthesized according to the method described in JP-A No. 7-53946 or the like.

In the present invention, the dye that can be decolorized during the above-mentioned development processing is preferably used in the form of solid fine particles. As a method for making the dye into solid fine particles, a known means for making fine particles (for example, ball mill, vibrating ball mill, planetary ball mill, sand mill, colloid mill, jet mill, roller mill) is used mechanically in the presence of a dispersion aid. Dispersion methods can be used.

As the dispersion aid to be used, the above-mentioned polymer compound is used, and if necessary, two or more kinds may be used in combination. At the same time, a known anionic, nonionic or cationic surfactant or polymer may be used in combination, but it is preferable to use only the above-mentioned polymer compound. The dispersion aid is generally mixed with a dye powder or a wet cake before dispersion and sent to a disperser as a slurry, but in advance in a state of being mixed with a dye, a heat treatment or a treatment with a solvent is performed. It may be dye powder or wet cake. It can also be added to the dispersion as it becomes finer during dispersion. Further, it may be added to the dispersion liquid to stabilize the physical properties after dispersion. In either case, it is common to allow a solvent (eg, water, alcohol, etc.) to coexist. Before or after the dispersion or during the dispersion, the pH may be controlled by a suitable pH adjuster.

In addition to mechanical dispersion, it may be dissolved in a solvent by controlling pH, and then the pH may be changed in the presence of a dispersion aid to form fine particles. At this time,
An organic solvent may be used as a solvent used for dissolution, and the organic solvent is usually removed after the formation of fine particles.

The prepared dispersion is stored with stirring for the purpose of suppressing the precipitation of fine particles during storage, or in a highly viscous state (for example, using gelatin to make a jelly state) with a hydrophilic colloid. You can also do it.
Further, it is preferable to add a preservative for the purpose of preventing the propagation of various bacteria during storage.

The solid fine particles of the dye thus prepared have an average particle size of usually 0.005 to 10 μm, preferably 0.01 to 3 μm, and particularly 0.05 to 0.5 μm.
It is preferably m.

Such a dye may be added to any part of the light-sensitive material, but at least one of the undercoating hydrophilic colloid layers provided between the support and the emulsion layer and / or the non-photosensitive hydrophilic layer. It is preferably added to the hydrophilic colloid layer.
Alternatively, two or more photographic emulsion layers may be laminated, and the dye may be introduced into the lower emulsion layer (the side closer to the support) of them. Here, the undercoat hydrophilic colloid layer is a hydrophilic colloid layer coated on a support, and the undercoat hydrophilic colloid layer is coated and dried, and then the upper layer is coated.
The non-photosensitive hydrophilic colloid layer coated on this undercoating hydrophilic colloid layer is a layer which is simultaneously superposed with the photosensitive silver halide emulsion layer which is the upper layer, and is a non-photosensitive hydrophilic colloid layer. A photosensitive silver halide emulsion layer is coated prior to drying.

Undercoating hydrophilic colloid, a dye in the form of solid fine particles contained in a non-photosensitive hydrophilic colloidal layer and / or a photographic emulsion layer coated between this undercoating hydrophilic colloid layer and this undercoating hydrophilic colloid layer. May be the same as or different from each other. Also, two or more dyes may be used in the same layer.

The amount of the decolorizable dye used in the solid content (the total of both sides of the support per 1 m ^{2 of} the support) depends on the required absorbance and the extinction coefficient of the dispersion, but usually 0.005 to 2 g /
It is in the range of m ² . The range is preferably 0.03 to ² g / m ² , and more preferably 0.04 to 0.15 g / m 2.
The range is ² , and particularly preferably 0.05 to 0.12 g.
The range is / m ² . At this time, the dye may be added to only one side.

Further, the method of forming the dye into solid fine particles and the particle size and shape of the solid fine particles may be the same or different.

The hydrophilic colloid is not particularly limited, but it is usually preferable to use gelatin.

The coating amount of gelatin contained in the hydrophilic hydrophilic colloid layer containing the dye is preferably in the range of 0.05 to 0.3 g per 1 m ² of one side of the support. Most preferably, it is in the range of 0.05 to 0.2 g.

The coating amount of gelatin contained in the non-photosensitive hydrophilic colloid layer containing the dye is preferably in the range of 0.05 to 0.5 g per 1 m ² of one side of the support. Most preferably, it is in the range of 0.1 to 0.4 g.

An undercoat hydrophilic colloid layer containing a decolorizable dye, a non-photosensitive hydrophilic colloid layer containing a dye,
The total amount of the hydrophilic colloids of the photosensitive silver halide emulsion layer and the surface protective layer is 1.4 per 1 m ² of one side of the support.
It is preferably in the range of to 2.6 g.

At least one of the above-mentioned undercoating hydrophilic colloid layer and non-photosensitive hydrophilic colloid layer preferably contains a gelatin-reactive polymer latex.

The gelatin-reactive polymer latex used preferably means that gelatin coated on the light-sensitive material and the reactive group on the surface of the polymer latex are chemically bonded to the gelatin end group, and particularly, active methylene group. Polymer latexes having

The polymer latex having an active methylene group preferred in the present invention is a polymer represented by the following general formula (II).

[0098]

[Chemical formula 26]

In the general formula (II), C ¹ represents a repeating unit derived from an ethylenically unsaturated monomer containing an active methylene group, A ¹ is other than C ¹ and the glass transition temperature of the homopolymer thereof. Represents a repeating unit derived from an ethylenically unsaturated monomer having a temperature of 35 ° C. or lower, B
¹ represents a repeating unit derived from an ethylenically unsaturated monomer other than C ¹ and A ¹ .

X, y, and z represent the weight percentage ratio of each component, x is 0.5 to 40, y is 60 to 99.5, and z is 0 to 0.
Takes a value of 50. Here, x + y + z = 100 is represented.

More specifically, the ethylenically unsaturated monomer containing an active methylene group represented by C ¹ is represented by the following formula.

[0102]

[Chemical 27]

In the formula, R ¹ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms (eg, methyl, ethyl, n-propyl,
n-butyl) or a halogen atom (for example, a chlorine atom,
Bromine atom), preferably a hydrogen atom, a methyl group or a chlorine atom.

X represents a monovalent group containing an active methylene group, which will be described in detail later.

L represents a single bond or a divalent linking group,
Specifically, it is represented by the following formula.

[0106]

[Chemical 28]

L ¹ is -CON (R ² )-, (provided that R is
² is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, 1 to 1 carbon atoms
6 represents a substituted alkyl group), —COO—, —NHCO
-, -OCO-, the following groups

[0108]

[Chemical 29]

(R ³ and R ⁴ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom or a substituted or unsubstituted alkyl group, an alkoxy group, an acyloxy group or an aryloxy group, and R ² has the same meaning as above. L ² represents a linking group connecting L ¹ and X, m 1 is 0 or 1, and m 2 is 0 or 1. The linking group represented by L ² is specifically represented by the following formula.

[0110]

[Chemical 30]

J ¹ , J ² and J ³ may be the same or different, and -CO-, -SO _2- , -CON (R ⁵ )-[R ⁵ is a hydrogen atom,
An alkyl group (having 1 to 6 carbon atoms) or a substituted alkyl group (having 1 to 6 carbon atoms)], -SO ₂ N (R ⁵ )-(R ⁵ has the same meaning as above), -N (R ⁵ ) -R ⁶ -(R ⁵ has the same meaning as above, R ⁶ has 1 carbon atom
To about 4 alkylene groups), -N (R ⁵ ) -R ⁶ -N (R ⁷ )-[R ⁵ , R
⁶ is as defined above, R ⁷ is a hydrogen atom, an alkyl group (having 1 to 6 carbon atoms), or a substituted alkyl group (having 1 to 6 carbon atoms)],
-O-, -S-, -N (R ⁵ ) -CO-N (R ⁷ )-(R ⁵ and R ⁷ are as defined above), -N (R ⁵ ) -SO ₂ -N (R ⁷ ). -(R ⁵ and R ⁷ are as defined above), -COO-, -OCO-, -N (R ⁵ ) CO _2- (where R ⁵ is as defined above), -N (R ⁵ ) CO- (R ⁵ Is synonymous with the above) and the like.

P, q, r and s are 0 or 1.

X ¹ , X ² and X ^{3, which} may be the same or different, each represents an unsubstituted or substituted alkylene group having 1 to 10 carbon atoms, an aralkylene group or a phenylene group, and the alkylene group may be a straight chain. It may be a branch. Examples of alkylene groups include methylene, methylmethylene, dimethylmethylene, dimethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, decylmethylene, aralkylene groups such as benzylidene, and phenylene groups such as p-phenylene, m-phenylene, methyl. There is phenylene.

Preferred specific examples of the monovalent group containing an active methylene group represented by X are R ⁸ —CO—CH ₂ —COO—, NC
^{_{-CH 2 -COO-, R 8 -CO-}} CH 2 -CO-, R 8 -CO-CH 2 -CON (R 5) - can be exemplified. Where R ⁵ is the same as above and R ^5
8 is a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms (for example, methyl, ethyl, n-propyl, n-butyl,
t-butyl, n-nonyl, 2-methoxyethyl, 4-phenoxybutyl, benzyl, 2-methanesulfonamidoethyl etc.), a substituted or unsubstituted aryl group (eg phenyl, p-methylphenyl, p-methoxyphenyl,
o-chlorophenyl etc.), an alkoxy group (eg methoxy, ethoxy, methoxyethoxy, n-butoxy etc.), a cycloalkyloxy group (eg cyclihexyloxy), aryloxy (eg phenoxy, p-methylphenoxy, o-chlorophenoxy, p-cyanophenoxy, etc.), amino acids, and substituted amino groups (eg, methylamino, ethylamino, dimethylamino, butylamino, etc.).

Examples of the polymer represented by the general formula (II) include, but are not limited to, ethylenically unsaturated monomers having an active methylene group represented by C ¹ .

M-1 2-acetoacetoxyethyl methacrylate M-2 2-acetoacetoxyethyl acrylate M-3 2-acetoacetoxypropyl methacrylate M-4 2-acetoacetoxypropyl acrylate M-5 2-acetoacetamidoethyl methacrylate M- 6 2-acetoacetamide ethyl acrylate M-7 2-cyanoacetoxyethyl methacrylate M-8 2-cyanoacetoxyethyl acrylate M-9 N- (2-cyanoacetoxyethyl) acrylamide M-10 2-propionylacetoxyethyl acrylate M-11 N- (2-propionylacetoxyethyl) methacrylamide M-12 N-4- (acetoacetoxybenzyl) phenylacrylamide M-13 ethylacryloyl acetate M-14 acryloyl Methyl acetate M-15 N-methacryloyloxymethylacetoacetamide M-16 Ethyl methacryloylacetoacetate M-17 N-allylcyanoacetamide M-18 Methylacryloylacetoacetate M-19 N- (2-methacryloyloxymethyl) cyanoacetamide M -20 p- (2-acetoacetyl) ethylstyrene M-21 4-acetoacetyl-1-methacryloylpiperazine M-22 ethyl-α-acetoacetoxymethacrylate M-23 N-butyl-N-acryloyloxyethylacetoacetamide M- 24 p- (2-acetoacetoxy) ethylstyrene

The ethylenically unsaturated monomer which gives the repeating unit represented by A ¹ is a monomer whose homopolymer has a glass transition temperature of 35 ° C. or lower, and more specifically, an acrylate (for example, methyl). Acrylate,
Ethyl acrylate, n-butyl acrylate, n-hexyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, n-dodecyl acrylate, etc.), alkyl methacrylate (for example, n-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-). Dodecyl methacrylate, etc.), dienes (eg, butadiene, isoprene, etc.), vinyl esters (eg, vinyl acetate, vinyl propionate, etc.) can be mentioned.

Further preferred monomers are monomers having a glass transition temperature of a homopolymer of 10 ° C. or lower, and such monomers include alkyl acrylates having an alkyl side chain of 2 or more carbon atoms (eg ethyl acrylate, n-). Butyl acrylate, 2-ethylhexyl acrylate, etc.), alkyl methacrylates having an alkyl side chain of 6 or more carbon atoms (for example, n-hexyl methacrylate, 2-ethylhexyl methacrylate, etc.), dienes (for example, butadiene, isoprene) are particularly preferable examples. Can be mentioned.

Regarding the value of the glass transition temperature of the above-mentioned polymer, see “Polymer Hand” edited by J. Brandrup and EHImmergut.
book ”Third Edition (John Wiley & Sons, 1989) V1 / 209 ~
# V1 / 277 page.

The repeating unit represented by B ¹ is a repeating unit other than A ¹ , that is, a repeating unit derived from a monomer whose homopolymer has a glass transition temperature of higher than 35 ° C.

Specifically, acrylic acid esters (eg, t-butyl acrylate, phenyl acrylate,
2-naphthyl acrylate, etc., methacrylic acid esters (for example, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, benzyl methacrylate, 2-hydroxypropyl methacrylate, phenyl methacrylate, cresyl methacrylate, 4-chlorobenzyl methacrylate, ethylene chloride) Vinyl ester (eg vinyl benzoate, pivaloyloxyethylene etc.); acrylamide (eg acrylamide, methyl acrylamide, ethyl acrylamide, propyl acrylamide, butyl acrylamide, tert-butyl acrylamide, cyclohexyl acrylamide, etc.) Benzyl acrylamide, hydroxymethyl acrylamide, methoxyethyl acrylate , Dimethylaminoethyl acrylamide, phenyl acrylamide, dimethyl acrylamide, diethyl acrylamide, β-cyanoethyl acrylamide, diacetone acrylamide, etc.);

Methacrylamides (eg, methacrylamide, methylmethacrylamide, ethylmethacrylamide, propylmethacrylamide, butylmethacrylamide, tert-butylmethacrylamide, cyclohexylmethacrylamide, benzylmethacrylamide, hydroxymethylmethacrylamide, methoxyethylmethacrylamide). Amide, dimethylaminoethyl methacrylamide, phenyl methacrylamide, dimethyl methacrylamide,
Diethyl methacrylamide, β-cyanoethyl methacrylamide, etc.);

Styrenes (eg, styrene, methylstyrene, dimethylstyrene, trimethylenestyrene, ethylstyrene, isopropylstyrene, chlorostyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromstyrene, vinyl benzoic acid methyl ester) Etc.); divinylbenzene, acrylonitrile, methacrylonitrile, N-vinylpyrrolidone, N-vinyloxazolidone, vinylidene chloride, phenyl vinyl ketone and the like.

Further, in the polymer represented by the formula (II), JP-B-60-15935 and JP-A-45-383.
No. 2, JP-A No. 53-28086, US Pat. No. 3,
A monomer having an anionic functional group (for example, a carboxyl group or a sulfonic acid group) as described in 700,456, etc. may be copolymerized for the purpose of improving the stability of the latex.

Examples of such a monomer include the following compounds. Acrylic acid; Methacrylic acid;
Itaconic acid, maleic acid; Monoalkyl itaconate, such as monomethyl itaconate, monoethyl itaconate, etc .; Monoalkyl maleate, such as monomethyl maleate, monoethyl maleate, etc .; Citraconic acid; Styrene sulfonic acid; Vinylbenzyl sulfonic acid; Vinyl sulfonic acid; acryloyloxyalkyl sulfonic acid, such as acryloyloxymethyl sulfonic acid, acryloyloxyethyl sulfonic acid, acryloyloxypropyl sulfonic acid, and the like; methacryloyloxyalkyl sulfonic acid, such as methacryloyloxymethyl sulfonic acid, methacryloyloxyethyl sulfonic acid , Methacryloyloxypropyl sulfonic acid and the like; acrylamidoalkyl sulfonic acid, for example 2-acrylamido-
2-Methylethanesulfonic acid, 2-acrylamide-2
-Methylpropanesulfonic acid, 2-acrylamido-2
-Methylbutane sulfonic acid and the like; methacrylamide amido sulfonic acid, for example 2-methacrylamido-2-
Methylethanesulfonic acid, 2-methacrylamide-2-
Methylpropanesulfonic acid, 2-methacrylamide-2
-Methylbutane sulfonic acid etc .; these acids may be salts of alkali metals (eg Na, K etc.) or ammonium ions.

X, y and z represent the weight percentage ratio of each monomer component in the polymer as described above, and x represents 0.5 to 40,
It is preferably 0.5 to 30, particularly preferably 1 to 20, y is 60 to 99.5, preferably 70 to 99.5,
Particularly preferably 75 to 99, and z is 0 to 5
0, preferably 0-35, particularly preferably 0-25.

Further, the above-mentioned monomer having an anionic functional group (monomer) can be used as necessary for imparting stability to the latex, regardless of the glass transition temperature of the homopolymer. And the preferred amount when used is 0.5 to 20% by weight, particularly preferably 1 to 10% by weight, based on the total weight of the polymer.

Preferred compounds of the polymer latex of the general formula (II) are exemplified below. In the parentheses, the weight percentage of each component in the copolymer is shown.

II-1 Ethyl acrylate / M-1 / acrylic acid copolymer (85/10/5) II-2 n-butyl acrylate / M-1 / methacrylic acid copolymer (85/5/10) II -3 to 7 n-butyl acrylate / M-1 / acrylic acid copolymer (x / y / z) II-3 x / y / z = 95/2/3 II-4 x / y / z = 92 / 5/3 II-5 x / y / z = 89/8/3 II-6 x / y / z = 81/16/3 II-7 x / y / z = 72/25/3 II-8 n- Butyl acrylate / styrene / M-1 /
Methacrylic acid copolymer (65/20/5/10) II-9 methyl acrylate / M-4 / methacrylic acid copolymer (80/15/5) II-10 n-butyl acrylate / M-5 / acrylic acid Copolymer (85/10/5) II-11 n-butyl acrylate / M-7 / methacrylic acid copolymer (85/10/5) II-12 2-ethylhexyl acrylate / M-
9 copolymer (75/25) II-13 n-butyl acrylate / M-14 / potassium styrenesulfinate copolymer (75/20/5) II-14 n-hexyl acrylate / methoxyethyl acrylate / M-2 Copolymer (70/20/10) II-15 2-ethylhexyl acrylate / M-15 /
Methacrylic acid copolymer (90/5/5) II-16 n-butyl acrylate / M-1 / M-17 /
Acrylic acid copolymer (75/5/15/5)

In the present invention, the polymer latex is prepared by a well-known emulsion polymerization method, and the particle size is preferably in the range of 0.01 to 0.1 μm.
The emulsion polymerization method is generally carried out by using a radical polymerization initiator by emulsifying a monomer in water or a mixed solvent of water and an organic solvent miscible with water (eg, methanol, ethanol, acetone, etc.) using at least one emulsifier. Thirty
C. to about 100.degree. C., preferably 40.degree. C. to about 90.degree. The amount of the organic solvent miscible with water is 0 to 100%, preferably 0 to 50% by volume with respect to water.

The polymerization reaction is usually carried out using 0.05 to 5% by weight of a radical weight initiator and, if necessary, 0.1 to 10% by weight of an emulsifier based on the monomers to be polymerized. Examples of the polymerization initiator include azobis compounds, peroxides, hydroperoxides, redox solvents and the like, for example, potassium persulfate, ammonium persulfate, tert-butyl peroctoate, benzoyl peroxide, isopropyl carbonate, 2,4-dichlorobenzyl peroxide. Oxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dicumyl peroxide,
There are 2,2'-azobisisobutyrate, 2,2'-azobis (2-amidinopropane) hydrochloride and the like.

As the emulsifier, anionic, cationic,
Besides amphoteric or nonionic surfactants, there are water-soluble polymers and the like. For example, sodium laurate, sodium dodecyl sulfate, 1-octoxycarbonylmethyl-1-octoxycarbonylmethanesulfonate, sodium laurylnaphthalenesulfonate, sodium laurylbenzenesulfonate, sodium laurylphosphate, cetyltrimethylammonium chloride, dodecyl. Trimethylene ammonium chloride, N-2-
Examples include ethylhexylpyridinium chloride, polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan laurin ester, polyvinyl alcohol, emulsifiers described in JP-B No. 53-6190, and water-soluble polymers.

In emulsion polymerization, depending on the purpose,
Wide range of polymerization initiator, concentration, polymerization temperature, reaction time, etc.
And, needless to say, it can be easily changed. Also,
The emulsion polymerization reaction may be carried out by previously putting all of the monomer surfactant and medium in a container and adding an initiator,
If necessary, the polymerization may be carried out while dropping a part or the whole amount of each component.

Regarding the types of monomers and polymer latices having an active methylene group represented by C ¹ in the polymer represented by the general formula (II) of the present invention and the synthesis method thereof, in addition to the above, US Pat. , 790 Specification,
No. 3,619,195, No. 3,929,482.
No. 3,700,456, West German Patent No. 2,442,165, European Patent No. 13,147, Japanese Patent Laid-Open No. 50-73625, and No. 50-1463.
It can be carried out with reference to the description in the publication No. 31, etc. Further, the polymer latex having an active methylene group is preferably a polymer latex having a core / shell structure.

In the present invention, the polymer latex having an active methylene group is the ratio of the content of gelatin in the emulsion layer to the content of gelatin in the non-photosensitive hydrophilic colloid layer above the emulsion layer (content of emulsion layer). / Content of non-photosensitive layer) is 1.0 or less, preferably 0.9 to 0.

When there are a plurality of emulsion layers, the content of the polymer latex in the emulsion layer is determined from the total amount of gelatin and the total amount of polymer latex. When there are a plurality of non-photosensitive layers above the emulsion layer, the content ratio of at least one polymer latex in gelatin to gelatin may be within the above range with respect to the content ratio in the emulsion layer. The amount of the polymer latex having an active methylene group used is arbitrary as long as the content ratio is satisfied, but preferably 10 mg / m ^{2 to} 10 g / m.
² , especially 100 mg / m ^{2 to} 1.5 g / m ² . The content of gelatin in the additive layer is in the range of 5 to 400% by weight, particularly preferably 10 to 200% by weight.

In the present invention, the ratio of the sum of the projected areas of tabular grains having an aspect ratio of 2 or more and 30 or less to the total of the total projected areas of silver halide grains contained in the photosensitive silver halide emulsion layer is It is preferably 50% or more and 100% or less, and most preferably 80% or more and 100% or less. The average aspect ratio of the tabular silver halide grains contained in the photosensitive silver halide emulsion layer is preferably 3 or more and 20 or less. The average aspect ratio as used herein is a value obtained by dividing the average diameter of the projected area circles of the tabular grains by the average thickness of the tabular grains. Higher aspect ratios of tabular silver halide emulsions provide lower blue sensitivity and higher green sensitivity, thus providing good performance when combined with an intensifying screen according to the present invention.

In the present invention, the tabular silver halide emulsion is silver chloride, silver bromide, silver iodide, silver chlorobromide, silver iodobromide, etc., but the halogen composition is arbitrary, but the average is 0 mol% or more. Silver iodobromide and silver iodochlorobromide containing 0.5 mol% or less of silver iodide are preferable. Or on average 50 mol% or more 10
A silver chloro (iodobromide) emulsion containing 0 mol% or less of silver chloride is also preferably used. Since the emulsion having such a halogen composition has lower blue sensitivity, good performance can be obtained when combined with the intensifying screen of the present invention. As a preferred method for producing tabular silver halide grains in the present invention, methods known in the art can be appropriately combined. In particular, monodisperse hexagonal tabular grains described in JP-A-63-151618, and JP-A-62-11.
5435, JP-A-6-43605, and JP-A-6-43606 have an average thickness of 0.1 μm.
Tabular silver halide grains having a size of m or less are extremely useful.

In the present invention, the surface protective layer provided on the photosensitive silver halide emulsion layer may be the same as known ones, and a hydrophilic colloid such as gelatin is used as a binder. In addition, various known supports are used as the transparent support, and polyethylene terephthalate (PET) is used.
Etc. are preferably used.

Preferred examples of the silver halide photographic light-sensitive material (radiophotographic film) used in combination with the radiation intensifying screen in the present invention and materials used therefor will be described below. 1) those described in Example 1 of JP-A-6-332088 and those described in Examples 1 and 2 of JP-A-7-219162 2) Silver chloride tabular emulsion having {100} main planes Those described in Examples 3 and 4 of JP-A-204073, the emulsion described in Example 2a of JP-A-6-194768, those described in Example 1 of JP-A-6-227431 3) {111} main Flat silver iodobromide, silver bromide, silver chlorobromide light-sensitive material described in Example 1 of JP-A-8-76305, emulsion 4 described in Examples A-K of JP-A-8-69069. ) Monodisperse cubic particles (preferably monodisperse is 3 to 40% as a variation coefficient of projected area diameter) Those described in Example 1 of JP-A-8-76305. Other preferable photographic light-sensitive materials or materials used therefor. About the special 1 of Kaihei 6-67305
There is detailed description on page 0, left column, line 10 to page 21, right column, line 33.

In the present invention, it is also preferable to slightly shift the spectral sensitivity distribution of the photographic light-sensitive material so that the light having the emission wavelength of the fluorescent dye or fluorescent pigment can be used more effectively. Examples of a method for changing the spectral sensitivity distribution include widely known methods such as combined use of thiocyanate, combined use of monomethine dye, azaindene compound, imidazole dye, and silver iodide.

The photographic light-sensitive material and the radiation intensifying screen may be used in combination one by one, but in many cases, two intensifying screens (two intensifying screens) for the photographic light-sensitive material having photographic emulsion layers on both sides are used. Usually, it is used by sandwiching a front side intensifying screen and a back side intensifying screen.

In the present invention, as a developing agent for processing a photographic light-sensitive material, a polyhydroxybenzene compound represented by hydroquinone, which has been conventionally used in a processing system for a medical silver halide photographic light-sensitive material, or ascorbine is used. An acid or erythorbic acid (a diastereomer of ascorbic acid) and alkali metal salts such as lithium salt, sodium salt and potassium salt thereof are preferably used.

To process the photographic light-sensitive material of the present invention, D
The ry-to-dry treatment time is preferably 20 to 100 seconds, and most preferably 25 to 50 seconds. Further, for processing the photographic light-sensitive material of the present invention, the replenishment amounts for development and fixing are preferably 25 to 200 mL per 1 m ² of the photographic light-sensitive material.
0 to 160 mL is more preferable, and 60 to 130 mL is the most preferable.

The silver halide photographic light-sensitive material of the present invention has an environmental condition of 1.4% by weight or less in absolute humidity, preferably 1.3 to 0.6% by weight, when it is wound on a roll after coating and drying. It is preferable to be wound up with. In the present invention, the product processing of the silver halide photographic light-sensitive material wound up in a roll after coating and drying is performed in an environment where the absolute humidity is 1.4 wt% or less, preferably 1.3 to 0.6 wt% or less. It is preferably processed below. Here, the absolute humidity (% by weight) is
Indicates the condition of moist air, the amount of water vapor in the moist air (kg)
And the ratio of the weight (kg) of dry air in humid air is expressed in percentage.

The silver halide photographic light-sensitive material was put in a moisture-proof package, and its mouth was adjusted so that the absolute humidity in the package was 1.4% by weight or less, preferably 1.1 to 0.6% by weight. Is preferably sealed by a method such as heat sealing, and the light-sensitive material is in equilibrium at the above absolute humidity. Further, it is particularly preferable to perform seasoning in an environment having an absolute humidity of 1.4% by weight or less after processing, and then heat-seal-seal in a package in the same environment.

[0147]

EXAMPLES [Example 1] <Preparation of radiation intensifying screen A> 1) Production of support with titanium dioxide-containing reflective layer Rutile titanium dioxide powder having an average particle size of 0.28 μm (manufactured by Ishihara Sangyo Co., Ltd., product Name: CR95) 500 g and acrylic binder resin (manufactured by Dainippon Ink and Chemicals, Inc., trade name: Chriscoat P1018GS) 100
and g were added to methyl ethyl ketone and mixed and dispersed to prepare a coating solution having a viscosity of 10 PS. Using a doctor blade, the coating solution was uniformly applied to the surface of a polyethylene terephthalate film (thickness: 250 μm) in which titanium dioxide powder was kneaded so that the thickness after drying was 40 μm, and the coating was dried to contain titanium dioxide. A support with a light reflecting layer was obtained. The volume filling factor of titanium dioxide in the obtained support with a light-reflecting layer was 48%, and the diffuse reflectance factor for monochromatic light having a wavelength of 545 nm (a wavelength corresponding to the emission peak of the terbium-activated gadolinium oxysulfide phosphor described later) was 95.5%
Met.

2) Production of phosphor sheet Terbium activated gadolinium oxysulfide phosphor (Gd ₂ O ₂
S: Tb, Tb activation amount: 0.003 (0.3 mol%),
Average particle size: 3.5 μm) 250 g, polyurethane binder resin (manufactured by Dainippon Ink and Chemicals, Inc., trade name: Pandex T5265M) 8 g, epoxy binder resin (manufactured by Yuka Shell Epoxy Co., Ltd., trade name:
Epicoat 1001) 2 g, fluorescent dye No. 25 (coumarin-6, manufactured by Aldrich, compound number 44, 26
3-1) 10 mg, and an isocyanate compound (Nippon Polyurethane Industry Co., Ltd., trade name: Coronate H
X) 0.5 g was added to methyl ethyl ketone and dispersed by a propeller mixer to prepare a phosphor layer-forming coating liquid having a viscosity of 25 PS (25 ° C.). This coating solution was applied on the surface of a temporary support (a polyethylene terephthalate sheet to which a silicone-based release agent was applied in advance) and dried to form a phosphor layer. This phosphor layer was peeled off from the temporary support to obtain a phosphor sheet.

3) Providing a phosphor sheet on the light reflecting layer The above phosphor sheet is superposed on the surface of the light reflecting layer of the support having the light reflecting layer produced in the above step 1), and the calendar sheet is used. Then, pressure was applied under the conditions of a pressure of 400 kgw / cm ² and a temperature of 80 ° C. to form a phosphor layer on the light reflection layer. The thickness of the obtained phosphor layer was 100 μm, and the volume filling rate of the phosphor particles in the phosphor layer was 68%.

4) Formation of Surface Protective Layer For the surface protective layer, 3% by weight of anatase-type titanium oxide (trade name: A220, manufactured by Ishihara Sangyo Co., Ltd.) was kneaded into polyethylene terephthalate (PET) having a thickness of 6 μm. It was made. The PET film had a scattering length by monochromatic light of 545 nm of 30 μm and a haze of 50. A polyester-based adhesive was applied to this one surface, and a surface protective layer was provided on the phosphor layer by a laminating method. In this way, a radiation intensifying screen A including the support, the light reflecting layer, the phosphor layer and the surface protective layer was obtained.

<Production of Radiation Intensifying Screens B, C and D> In the production of the radiation intensifying screen A, fluorescent dye No. Radiographic intensifying screens B, C and D of the present invention were produced in the same manner except that the addition amount and type of 25 were changed as shown in Table 2.

<Production of Comparative Radiation Intensifying Screens X, Y and Z> In the production of the radiation intensifying screen A, fluorescent dye No. A yellow dye that does not emit fluorescence instead of 25 (manufactured by Orient Industry Co., Ltd., trade name: oil yellow 3
Radiographic intensifying screens X and Y for comparison were prepared in the same manner except that G) was added in the amount shown in Table 2. Further, in the preparation of the radiation intensifying screen A, a radiation intensifying screen Z for comparison was prepared in the same manner except that the fluorescent dye was not added.

<Measurement of Emission Spectra> The fluorescence emission spectrum by X-ray (W tube, 40 kVp) was measured by improving the fluorescence measuring device (F-4010 manufactured by Hitachi, Ltd.). The results are shown in FIGS. Figure 1
Shows the emission spectrum of screen B to which the fluorescent dye of the present invention was added. FIG. 2 shows the emission spectrum of a conventional screen Z without addition of fluorescent dye for comparison. FIG. 3 shows the emission spectrum of Screen X with the addition of a yellow absorbing dye for comparison.

Comparing FIGS. 1 and 2, in the screen B of the present invention, due to the fluorescent dye contained therein, Gd ₂ O ₂
It can be seen that among the plurality of emission bright lines of the S: Tb phosphor, light having a wavelength shorter than 500 nm is absorbed, and broad emission having a peak at 520 nm is exhibited. That is, the screen B of the present invention has a blue light emitting component (wavelength 380 to 5).
100 nm, and a green emission component (wavelength 500 n)
It can be seen that the screen has an increased m.about.570 nm). Further, as is apparent from FIG. 3, in the screen X, the absorption dye contained in the screen X reduces the blue emission component, which is preferable as the effect of reducing crossover, but the sensitivity is increased by the contribution of the blue emission component. Is inevitable.

FIG. 4 shows an emission spectrum when the screen B was excited with light having a wavelength of 417 nm. Fluorescent dye No. It can be seen that 25 shows light emission with a half-value width of 58 nm having an emission peak at about 520 nm. Further, FIG. 5 shows a spectral sensitivity spectrum of a silver halide photographic light-sensitive material (Sample 1) of the present invention described later. From FIG. 5, it is clear that the green light emitting component contributes more to the sensitivity than the blue light emitting component, and it is preferable that the emission peak wavelength of the fluorescent dye is in the range of 490 to 600 nm. Further, it is clear that the blue light emitting component is less absorbed by the light-sensitive material, and it can be seen that by reducing the ratio of the blue light emitting component of the screen, a radiographic assembly that more effectively reduces crossover can be obtained.

<Preparation of Silver Halide Photosensitive Material (Sample 1)> A silver halide photographic material (Sample 1) was prepared by the following method. (Emulsion A: Preparation of {111} AgBr tabular grains) Water 1
6.0 g potassium bromide and 1 weight average molecular weight per liter
With the addition of 15,000 low molecular weight gelatin 7.0g, 38ml of an aqueous solution containing 37cc of silver nitrate aqueous solution (4.00g of silver nitrate) and 5.9g of potassium bromide was stirred by a double jet method into a container kept at 55 ° C. Added in 37 seconds. Next, after adding 18.6 g of gelatin, the temperature was raised to 70 ° C. and 89 mL of an aqueous silver nitrate solution (9.80 g of silver nitrate) was added over 22 minutes. Here, 7 mL of 25% aqueous ammonia solution was added, and after physically aging for 10 minutes at the same temperature, 6.5 mL of 100% acetic acid aqueous solution was added.
Subsequently, 435 mL of an aqueous solution of 153 g of silver nitrate and 677 mL of an aqueous solution of 573 g of potassium bromide were added in such a manner that the total amount of the aqueous silver nitrate solution was added over 35 minutes by the control double jet method while keeping the pAg at 8.5. Next 2N
15 mL of potassium thiocyanate solution of was added. After physically aging for 5 minutes at the same temperature, the temperature was lowered to 35 ° C.

The shape characteristic value of the obtained grain was (total projected area of {111} tabular grains having aspect ratio of 2 or more and 30 or less / sum of projected areas of all silver halide grains) × 1
00 = a1 = 95% (average aspect ratio (average diameter / average thickness) of {111} tabular grains having an aspect ratio of 2 or more and 30 or less) = a2 =
12.0 (average projected area diameter of {111} tabular grains having an aspect ratio of 2 or more and 30 or less = a3 = 1.20 μm (average thickness of {111} tabular grains having an aspect ratio of 2 or more and 30 or less) = a4 = 0.10 μm Monodisperse silver bromide having a projected area diameter variation coefficient of 15.5% {1
11} Tabular grains were obtained. After this, the soluble salts were removed by the sedimentation method. The temperature was raised to 40 ° C again, and 30 g of deionized and alkali-treated gelatin and phenoxyethanol 2.3 were used.
5 g and 0.8 g of sodium polystyrene sulfonate as a thickener were added, and the pH was adjusted to 5. with caustic soda and silver nitrate.
90, pAg 8.00.

(Chemical Sensitization) The particles prepared as described above were chemically sensitized while being kept at 56 ° C. with stirring.
First, 1 × 10 ⁻⁴ mol of thiosulfonic acid compound-1 was added per mol of silver halide, and then the average grain diameter of 0.
0.1 μ% of 10 μm AgI fine particles to the total silver amount
5 minutes after the addition, a 1 wt% KI solution was added to the silver halide 1
1 × 10 ⁻³ mol per mol was added, and after further 3 minutes, 1 × 10 ⁻⁶ mol / mol Ag of thiourea dioxide was added, and the mixture was held for 22 minutes for reduction sensitization. Next, 4-hydroxy-methyl-1,3,3a, 7-tetraazaindene was added to 3
The following amounts of x10 ^-4 mol / mol Ag and the following sensitizing dyes-1, 2 and 3 were added. Then add 1 part of calcium chloride
× 10 ^-2 mol / mol Ag was added. Chloroauric acid 1 x
10 ^-5 mol / mol Ag and potassium thiocyanate 3.0
× 10 ⁻³ mol / mol Ag was added, followed by sodium thiosulfate (6 × 10 ⁻⁶ mol / mol Ag) and selenium compound-1 (4 × 10 ⁻⁶ mol / mol Ag). After a further 3 minutes, nucleic acid (0.5 g / mol Ag) was added. Four
After 0 minutes, the following water-soluble mercapto compound-1 was added, and 3
Cooled to 5 ° C. Thus, preparation of the emulsion (chemical ripening) was completed.

[0159]

[Chemical 31]

(Preparation of Emulsion Layer Coating Solution) An emulsion coating solution was prepared by adding the following chemicals to 1 mole of silver halide to the above chemically sensitized emulsion.

[0161] Gelatin (including gelatin in emulsion) 80g Dextran (average molecular weight 39,000) 10.0 g Sodium polyacrylate (average molecular weight 400,000) 5.1g Sodium polystyrene sulfonate (average molecular weight 600,000) 1.2g 78 mg potassium iodide Hardener 1,2-bis (vinylsulfonylacetamide) ethane 4.3 g Compound A-1 42.1 mg Compound A-2 10.3 g Compound A-3 0.11 g Compound A-4 8.5 mg Compound A-5 0.43 g Compound A-6 0.04 g Compound A-7 15 g Dye emulsion a (as solid dye content) 0.50 g Dye emulsion m (as dye solid content) 30mg (PH adjusted to 6.1 with NaOH)

The compounds A-1 to A-7 in the above are as follows.

[0163]

[Chemical 32]

The above-mentioned dye dispersions a and m are prepared as follows.

(Preparation of Dye Emulsion a) The following Dye-1 was used.
0 g and 2,4-diamylphenol 62.8 g,
62.8 g of dicyclohexyl phthalate and 333 g of ethyl acetate were dissolved at 60 ° C. Next, 65 ml of a 5% by weight aqueous solution of sodium dodecylbenzenesulfonate, 94 g of gelatin and 581 mL of water were added, and the mixture was emulsified and dispersed at 60 ° C. for 30 minutes with a dissolver. Next, 2 g of methyl p-hydroxybenzoate and 6 liters of water were added,
The temperature was lowered to 40 ° C. Next, using Asahi Kasei Corp. ultrafiltration laboratory module ACP1050, the total amount was concentrated to 2 kg, and 1 g of methyl p-hydroxybenzoate was added to obtain a dye emulsion a.

[0166]

[Chemical 33]

(Preparation of Dye Emulsion m) 1
Weigh 0 g and add 10 mL of tricresyl phosphate,
After dissolving in a solvent consisting of 20 mL of ethyl acetate, it was emulsified and dispersed in 100 mL of a 15 wt% gelatin aqueous solution containing 750 mg of the following anionic surfactant-1 to prepare a dye emulsion m.

[0168]

[Chemical 34]

(Preparation of Dye Layer Coating Solution) A coating solution was prepared so that each component of the dye layer had the following coating amount on one side.

Gelatin 0.25 g / m ² Compound A-8 1.4 mg / m ² Sodium polystyrene sulfonate (average molecular weight 600,000) 5.9 mg / m ² Dye dispersion A (as dye) (Table 1)

The above compound A-8 is shown below, and the dye dispersion A was prepared as follows.

[0172]

[Chemical 35]

(Preparation of Dye Dispersion A) Each of the dyes shown in Table 1 was treated as a wet cake without being dried, and weighed so as to be 2.5 mmol as a dye. 1.2 cc of the following dispersion aid V was added as a 25% by weight aqueous solution. Water was added to bring the total amount to 32 g, and they were mixed well to form a slurry. 12 zirconia beads with an average diameter of 1 mm
0 g was prepared, placed in a vessel together with the slurry, dispersed for 6 hours by a disperser (1 / 16G sand grinder mill: manufactured by AIMEX Co., Ltd.), and water was added so that the dye concentration became 2% by weight. A dispersion was obtained. The resulting dispersion is mixed so that the dye solids are 5% by weight and the photographic gelatin is the same as the dye solids by weight, so that the following additive D as a preservative is 2000 ppm with respect to the gelatin. Distilled water was added and the mixture was refrigerated and stored in a jelly form. In this way, Dye Dispersion A as a dye in the form of solid fine particles is prepared.
Got The average particle size of the solid fine particles of the dye dispersion is F-
In the case of 16, it was 0.4 μm.

[0174]

[Chemical 36]

(Preparation of Coating Solution for Surface Protective Layer) The coating solution for surface protective layer was prepared so that each component had the following coating amount.

[0176] Gelatin 0.780 g / m ² of sodium polyacrylate (average molecular weight 400,000) 0.025 g / m ² Sodium polystyrenesulfonate (average molecular weight 600,000) 0.0012 g / m ² Matting agent -1 (average particle size 3.7μm) 0.072g / m ² matting agent 2 (average particle size 0.7μm) 0.010g / m ² compound A-9 0.018g / m ² compound A-10 0.037g / m ² compound A -11 0.0068g / m ² compound A-12 0.0032g / m ² compound A-13 0.0012g / m ² compound A-14 0.0022g / m ² compound A-15 0.030g / m ² Proxel ( ICI) 0.0010 g / m ² (pH adjusted to 6.8 with NaOH)

Matting agents 1 and 2 described above and compounds A-9 to A
-15 is shown below.

[0178]

[Chemical 37]

[0179]

[Chemical 38]

(Preparation of Support) (1) Formation of First Undercoat Layer Corona discharge was performed on a biaxially stretched polyethylene terephthalate film having a thickness of 175 μm to prepare a first undercoat liquid preparation liquid having the following composition. Was coated with a wire converter so that the coating amount was 4.9 cc / m ^2, and the temperature was 185 ° C.
And dried for 1 minute to form a first undercoat layer. Next, a first undercoat layer was similarly provided on the opposite surface. The polyethylene terephthalate used contains 0.04% by weight of Dye-1 (above).
What was contained was used.

(First Undercoat Layer Preparation Liquid) Butadiene-styrene copolymer latex solution (solid content 40%, butadiene / styrene weight ratio = 31/69) 158 mL 2,4-dichloro-6-hydroxy-s-triazine Sodium salt 4 wt% solution 41 mL Distilled water 801 mL In the latex solution, the following compound A was used as an emulsifying dispersant.
-16 was contained in an amount of 0.4% by weight based on the latex solid content.

[0182]

[Chemical Formula 39]

(2) Formation of second undercoat layer A second undercoat layer preparation liquid having the following composition was applied onto the above-mentioned first undercoat layers on both sides in an amount of the amount described below per one side. So that each side is coated on both sides by the wire bar coder method (the coating amount is 7.9 cc / m ² per side),
It was dried at 155 ° C.

Gelatin 0.06 g / m ² Dye dispersion B (per surface as dye) (Table 1) Compound A-17 1.8 g / m ² Compound A-18 0.27 g / m ² Matting agent Average particle size 2 0.5 μm polymetal methacrylate 2.5 g / m ²

Dye Dispersion B was prepared in the same manner as Dye Dispersion A. The compounds A-17 and A-18 in the above are shown below.

[0186]

[Chemical 40]

(Preparation of photographic light-sensitive material) On the support prepared as described above, both sides were simultaneously coated from the side of the support by the simultaneous extrusion method so as to form a dye layer, an emulsion layer and a surface protective layer, and dried. . The amount of silver coated on one side is 1.5 g / m
^{Was 2} .

(Measurement of Swelling Ratio) First, the photographic material to be measured was aged for 7 days under the conditions of 40 ° C. and 60% RH. Next, this photographic material was immersed in distilled water at 21 ° C. for 3 minutes, and this state was freeze-fixed with liquid nitrogen. This photographic material was cut with a microtome so that its cross section was perpendicular to the surface of the photographic material, and then freeze-dried at -90 ° C. The swelled film thickness Tw was obtained by observing the above-mentioned processed material with a scanning electron microscope.
On the other hand, the film thickness Td in the dry state was also obtained by observing the cross section using a scanning electron microscope. Tw and T obtained in this way
The swelling ratio (unit%) was obtained by dividing the difference in d by Td and multiplying by 100.

[0189] {(Tw-Td) / Td} × 100 = swelling ratio (%)

In Sample 1, Td = 2.7 μm, T
w = 7.0 μm, and the swelling ratio was 159%.

<Measurement of Dye Absorption of Dye Layer and Undercoat Layer> To measure the dye absorption of the dye layer and / or the undercoat layer of Sample 1 thus prepared, the emulsion layer was prepared in the same manner. A sample (only the undercoat layer, the dye layer, and the surface protective layer) having no layer was prepared, and the absorption was measured. A normal spectrophotometer was used to measure the absorption, the sample was placed in front of the integrating sphere, and the polyethylene terephthalate film used for comparison was used. From this measurement, the absorption peak wavelength, the absorption coefficient at 550 nm, and the absorption coefficient at 450 nm were obtained. Table 1 shows the peak wavelength of absorption, the absorption coefficient at 550 nm and 450 nm.
The ratio with the absorption coefficient of is shown.

[0192]

[Table 1]

[Evaluation 1 by Combination of Radiation Intensifying Screen and Silver Halide Photosensitive Material] The sample 1 thus obtained and the screens A to D and X to Z were evaluated in combination.

(Exposure by X-rays) The above-mentioned screen and one side of the photosensitive material are brought into close contact with each other, and the X-ray source, the photosensitive material and the screen are arranged in this order from the X-ray source, and the X-ray exposure amount is logE by the distance method. Step exposure was performed with a width of 0.15.
The X-ray device used is the product name DRX-3 manufactured by Toshiba Corporation.
724HD, and a tungsten target was used.
The focal spot size was 0.6 mm × 0.6 mm, and it was an apparatus for generating X-rays through an aluminum equivalent material of 3 mm including a diaphragm. A voltage of 80 kVp was applied to the three phases with a pulse generator, and an X-ray that passed through a filter of 7 cm of water having almost the same absorption as the human body was used as a light source.

(Development of Film) The photographic film after photographing was taken as a developing solution and a fixing solution as CED2 and CEF2 by a roller transfer type automatic developing machine (trade name: CEPROS-M2) manufactured by Fuji Photo Film Co., Ltd., respectively. (All are product names of Fuji Photo Film Co., Ltd.)
Development processing was carried out in ry-to-Dry for 45 seconds (SP mode). Replenishing amount of developer and fixer is 10cc /
It was cut in four. 1) Each of the obtained double-sided samples after development was divided into two parts, and the back surface was removed by enzyme treatment while leaving the surface in contact with the intensifying screen. The sensitivity of the screen was determined by measuring the density of this sample. The sensitivity is shown as a relative value with the screen Z being 100. 2) Next, the front surface (the surface that was in contact with the intensifying screen) was removed, leaving the surface that was not in contact with the intensifying screen. The concentration of this sample is measured, the sensitivity difference with the sample of 1) is obtained, and the crossover (%) is calculated by the above-mentioned calculation formula.
I asked. Table 2 shows the sensitivity and crossover characteristic values of each screen thus obtained.

[0196]

[Table 2]                                   Table 2     ───────────────────────────────────   Screen Dye addition amount Sensitivity Crossover                   (Mg / phosphor 1kg) (%)     ───────────────────────────────────   Example A Fluorescent dye No. 25 40 mg 105 7.5           B fluorescent dye No. 25 120 mg 108 7           C fluorescent dye No. 25 15 mg 100 8.5           D fluorescent dye No. 23 60 mg 105 8     ───────────────────────────────────   Comparative Example X Yellow absorbing dye 40 mg 95 10.5           Y yellow absorption dye 120mg 858           Z-100 12     ───────────────────────────────────

As is clear from Table 2, the screens A, B, C and D of the present invention have high sensitivity and little crossover (thus, it can be said that they have high sharpness). In particular, the screen B had the best performance. The screens X and Y using known absorbing dyes for comparison can also reduce the crossover, but also reduce the sensitivity at the same time. It can be seen that the expected results were obtained from the emission spectra of FIGS.

[Example 2] <Production of Photosensitive Materials (Samples 2 to 5)> In Example 1,
Photosensitive materials (Samples 2 to 5) were prepared in the same manner as in Example 1 except that the dye coating amount of the dye layer was changed as shown in Table 1.

[Evaluation 2 with Screen / Sensitive Material] In the same manner as in Evaluation 1, the sensitivity and crossover were evaluated by combining the screen and the sensitive materials (Samples 1 to 5) as shown in Table 3. The results are shown in Table 3.

[0200]

[Table 3]                                   Table 3         ──────────────────────────────               Sensitive material Screen sensitivity Crossover (%)         ──────────────────────────────       Example Sample 1 B 108 7               Sample 2 B 108 5               Sample 3 B 108 2               Sample 4 B 108 11               Sample 5 B 108 17         ──────────────────────────────       Comparative Example Sample 1 Z 100 12               Sample 2 Z 100 10               Sample 3 Z 100 7               Sample 4 Z 100 14               Sample 5 Z 100 18         ──────────────────────────────

From these results, the screen B containing the fluorescent dye of the present invention is particularly preferable when combined with a light-sensitive material having a crossover of 10% or less as compared with the ordinary screen Z for comparison. It can be seen that the crossover reduction effect appears significantly.

[Example 3] <Preparation of Photosensitive Materials (Samples 6 to 9)> In Example 1,
Photosensitive materials (Samples 6 to 9) were prepared in the same manner as in Example 1 except that the type of dye and the coating amount of the dye layer and the undercoat layer were changed as shown in Table 1.

[Evaluation 3 with Screen / Sensitive Material] In the same manner as in Evaluation 1, the sensitivity and crossover were evaluated by combining the screen and the sensitive materials (Samples 6 to 9) as shown in Table 4. The results are shown in Table 4.

[0204]

[Table 4]                                   Table 4         ──────────────────────────────               Sensitive material Screen sensitivity Crossover (%)         ──────────────────────────────       Example Sample 6 D 105 10               Sample 7 D 105 3               Sample 8 D 105 5               Sample 9 D 105 12         ──────────────────────────────       Comparative Example Sample 6 X 100 14               Sample 7 x 100 9               Sample 8 x 100 7               Sample 9 x 100 14         ──────────────────────────────

As is apparent from Table 4, the screen of the present invention achieved an increase in sensitivity and a reduction in crossover when combined with various light-sensitive materials. In particular, it can be seen that the larger the ratio of the absorption coefficient at 550 nm / absorption coefficient at 450 nm (see Table 1), the greater the crossover reduction effect.

Example 4 A screen / light-sensitive material assembly was produced as follows. <Production of Radiation Intensifying Screens E to I> (1) In Example 1, except that the coating amount of the phosphor layer-forming coating liquid was adjusted so that the thickness of the phosphor layer after calendering was 80 μm. A screen E containing the fluorescent dye of the present invention was prepared in the same manner as in Example 1. (2) In Example 1, 50 g of the phosphor particles contained in the phosphor layer had an average particle size of 2.0 μm, and 200 g of the phosphor particles having an average particle size of 6.2 μm (the chemical composition of the phosphor). And the coating amount of the phosphor layer-forming coating liquid was adjusted so that the thickness of the phosphor layer after calendering was 120 μm, and the screen F of the present invention was prepared in the same manner as in Example 1. It was made. The volume filling rate of the phosphor particles in the phosphor layer was 72%. (3) In the same manner as (2) above, except that the coating amount of the coating liquid for forming a phosphor layer is adjusted so that the thickness of the phosphor layer after calendaring is 95 μm. The screen G of the present invention was produced. (4) In Example 1, the phosphor layer had an average particle size of 3.
0 μm, a layer containing phosphor particles having a variation coefficient of particle size distribution of 45% (lower layer), and a layer containing phosphor particles having an average particle diameter of 6.2 μm and a variation coefficient of particle size distribution of 30% ( Layer structure (upper layer) (phosphor has the same chemical composition) (lower layer thickness: 8)
The screen H of the present invention was produced in the same manner as in Example 1 except that the thickness was changed to 0 μm, the layer thickness of the upper layer: 100 μm, both of which were after calendering. The volume filling rate of the phosphor particles in the phosphor layer was 70%. (5) In Example 1, the phosphor layer had an average particle size of 3.
0 μm, a layer containing phosphor particles having a particle size distribution variation coefficient of 40% (lower layer), and a layer containing phosphor particles having an average particle size of 6.2 μm and a particle size distribution variation coefficient of 30% ( Layer structure (upper layer) (phosphor has the same chemical composition) (lower layer thickness: 8)
A screen I of the present invention was produced in the same manner as in Example 1 except that the thickness of the upper layer was changed to 0 μm and the thickness of the upper layer was changed to 240 μm.

<Preparation of Photosensitive Material (Sample 10)> Example 1
In the same manner as in Emulsion A in Example 1, except that the temperature of grain formation is changed and the chemical sensitization is appropriately adjusted ((average aspect ratio of {111} planographic grains having an aspect ratio of 2 to 30) (average diameter / average diameter / Average thickness)) = a2 =
8.0 (average projected area diameter of {111} planographic grains having an aspect ratio of 2 or more and 30 or less) = a3 = 0.6 μm (average thickness of {111} planographic grains having an aspect ratio of 2 or more and 30 or less) = a4 = 0.07 Monodisperse silver bromide with a coefficient of variation of projected area diameter of 18% {11
1} Planographic emulsion B was obtained. Similar to the sample in Example 2, F-16 was used as the dye in the dye layer at 50 mg / side.
m ² is added, but the emulsion layer is coated with Emulsion A and Emulsion B in a multi-layer structure so that a photographic material having the same sensitivity and gradation as UR2 film (trade name) manufactured by Fuji Photo Film Co., Ltd. Sample 10) was prepared.

<Preparation of Comparative Radiation Intensifying Screens P to T> In each of (1) to (5) of Example 4, fluorescent dye Nos. Screens P, Q, R, S for comparison were prepared in the same manner as in Example 4 except that 25 was not added.
T was produced.

[Evaluation with Screen / Sensitive Material 4] Sample 10
As shown in Table 5, two screens were adhered to both surfaces of the above and the performance was evaluated. Here, of the two screens, the screen arranged on the X-ray tube side was the front screen, and the screen on the opposite side was the back screen. These screen / sensitive material pairs were measured by the distance method to determine the X-ray exposure dose using the same X-ray source as shown in Evaluation 1.
Stepwise exposure was performed with a width of gE = 0.15. The density of the screen was measured after developing with a CEPROS-M2 automatic processor in the same manner as in Evaluation 1 to determine the sensitivity of the screen.
The sensitivity of the screen is shown as a relative value with 100 in the case of front screen / back screen = P / Q.

Further, in order to measure the sharpness, an image was taken using a rectangular chart for MTF measurement (made of molybdenum, thickness: 80 μm, spatial frequency: 0 line / mm to 10 line / mm). The chart was placed 2 m from the X-ray tube. After that, development processing similar to the measurement of sensitivity was performed. In addition, the previous X
The exposure amount at the time of line photography was adjusted so that the average value of the maximum density and the minimum density after the development processing was 1.0. next,
The evaluation sample was scanned with a microdensitometer. At this time, a slit having a scanning direction of 30 μm and a vertical direction of 500 μm was used as the aperture, and the concentration profile was measured at a sampling interval of 30 μm. This operation was repeated 20 times to calculate the average value, which was used as the density profile based on the calculation of the contrast transfer function (CTF). After that, the peak of the rectangular wave for each frequency in this density profile was detected, and the density contrast for each frequency was calculated. Then, CTF (2 lp / mm) was obtained by normalizing the density contrast by the density difference of 0 frequency, and was used as a scale representing the sharpness. The obtained sensitivity and sharpness (CTF) results are shown in Table 5.

[0211]

[Table 5]                                   Table 5     ───────────────────────────────────             Sensitive Material Front Back Sensitivity Sharpness                     Screen Screen (CTF)     ───────────────────────────────────   Example Sample 10 E F 104 0.610           Sample 10 GH 140 0.53           Sample 10 G I 210 0.37     ───────────────────────────────────   Comparative Example Sample 10 P Q 100 0.585           Sample 10 R S 130 0.510           Sample 10 RT 190 0.36           UR-2 HGM2 HGM2 100 0.500     ─────────────────────────────────── (Note) UR-2: Fuji Photo Film Co., Ltd. product       HGM2: Kasei Optonix Co., Ltd. product

As is apparent from Table 5, the screens E to I of the present invention had high sensitivity and high sharpness (CTF) when combined with the above-mentioned light-sensitive material (Sample 10).

[Example 5] <Preparation of photosensitive materials (Samples 11 and 12)> UR-1 was carried out in the same manner as in Example 4 except that the sensitivity of the emulsion was adjusted in place of Sample 10. And UR-3 (all are trade names of Fuji Photo Film Co., Ltd.) were prepared to have sensitizing materials (Samples 11 and 12) having the same layer structure, sensitivity and gradation.

[Evaluation 5 with Screen / Sensitive Material] Evaluation was performed in combination with a screen pair in the same manner as in Evaluation 4, but the same preferable results as in Table 5 were obtained.

[Evaluation 6 of Screen / Sensitive Material] The sensitive materials of Examples 4 and 5 were replaced by CEPROS-30, CEPROS-S and CEPR in place of the CEPROS-M2 automatic developing machine.
The following processing solutions were put in an OS-P automatic developing machine and developed for Dry to Dry for 30 seconds, 60 seconds and 120 seconds, respectively, and a favorable image was obtained without residual color.

(Preparation of Developer) A developer containing sodium erythorbate having the following formulation as a developing agent was prepared. Diethylenetriamine pentaacetic acid 8.0 g Sodium sulfite 20.0 g Sodium carbonate monohydrate 52.0 g Potassium carbonate 55.0 g Sodium erythorbate 60.0 g 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone 13.2 g 3,3′-diphenyl-3,3′-dithiopropionic acid 1.44 g diethyllenglycol 50.0 g

[0217]

[Chemical 41]

[0218]

[Chemical 42]

Water was added to make 2 liters. The pH was adjusted to 10.1 with sodium hydroxide.

(Preparation of Development Replenisher) The above developer was used as it was as a development replenisher.

(Preparation of developing mother liquor) 2 l of the above developing solution was taken, 55 ml of a starter solution having the following composition was added to 1 l of the developing solution, and a developing solution having a pH of 9.5 was used as the developing mother solution.

[0222] (Preparation of starter solution) Potassium bromide 11.1 g Acetic acid 10.8g Water was added to make 55 mL.

(Preparation of concentrated fixer) A concentrated fixer having the following formulation was prepared. Water 0.5 liter Ethylenediaminetetraacetic acid dihydrate 0.05 g Sodium thiosulfate 200 g Sodium bisulfite 98.0 g Sodium hydroxide 2.9 g pH was adjusted to 5.2 with NaOH and water was added to make 1 liter.

(Preparation of Fixing Replenisher) The concentrated fixing solution was diluted 2-fold with the first washing water waste solution and used as a fixing replenisher.

(Preparation of fixing mother liquor) 2 liters of the concentrated fixing solution was diluted with water to 4 liters. The pH was 5.4.

(Replenisher for Washing Water) Glutaraldehyde 0.3 g Diethylene-triamine-penta-acetic-acid 0.5 g Diluted with distilled water and adjusted to pH 4.5 with NaOH to obtain 1 liter of a completed liquid. It was

[Example 6] <Preparation of radiation intensifying screens J to M> In the same manner as in Example 1, except that the kind and addition amount of the fluorescent dye were changed as shown in Table 6 in Example 1. Radiographic intensifying screens JM according to the present invention were prepared.

[Evaluation 7 with Screen / Sensitive Material] In the same manner as in Evaluation 1, sensitivity and crossover were evaluated by combining a screen and a sensitive material (Sample 2). The results are shown in Table 6. Table 6 also shows peak wavelengths and half widths of light emission when the fluorescent dye contained in each screen was excited by light having a wavelength of 417 nm.

[0229]

[Table 6]

As is clear from Table 6, the effects of the present invention were preferably exhibited in various fluorescent dyes. Further, it is found that the sensitivity is high and the crossover is small when the peak wavelength of the emission of the fluorescent dye is particularly in the range of 500 to 555 nm. It can also be seen from the spectral sensitivity spectrum of the light-sensitive material shown in FIG. 5 that the emission will not effectively contribute to the sensitivity if the emission wavelength of the fluorescent dye becomes short. On the other hand, when the emission wavelength of the fluorescent dye becomes long, its excitation spectrum (absorption spectrum) also becomes long and the wavelength becomes 545n.
It is presumed that the sensitivity tends to decrease because a part of the effective light emitted by the Gd ₂ O ₂ S: Tb phosphor showing an emission peak at m is also absorbed (Screen J). If the absorption spectrum remains at a short wavelength (that is, if the Stokes shift is reasonably large), it is presumed that an emission peak near 545 nm, where the spectral sensitivity of the photosensitive material is higher, is preferable. Further, it can be seen that the narrower the half value width of the light emission by the fluorescent dye, the higher the sensitivity.

FIG. 6 shows the excitation spectrum (that is, the absorption spectrum of the fluorescent dye) when the screen B of the present invention having the best performance is caused to emit light at a wavelength of 520 nm.
As is clear from FIG. 6, the fluorescent dye contained in the screen B showed high absorption in the range of 380 to 500 nm, while there was no absorption in the vicinity of 545 nm. Therefore,
In the present invention, the fluorescent dye of screen B (coumarin-
As in 6), it is presumed that a fluorescent dye or pigment that absorbs light in the range of 380 to 500 nm and emits light with a narrow half width near 545 nm is most preferable.

[Example 7] <Production of radiation intensifying screens B2 and B3> In the production of the screen B of Example 1, the Tb activation amount of the Gd ₂ O ₂ S: Tb phosphor was changed as shown in Table 7. The radiation intensifying screen B of the present invention is the same as in Example 1 except for the above.
2 and B3 were produced.

<Production of Comparative Radiation Intensifying Screens Z2 and Z3> In the production of the screen Z of Example 1, Gd ₂
Radiographic intensifying screens Z2 and Z3 for comparison were prepared in the same manner as in Example 1 except that the Tb activation amount of the O ₂ S: Tb phosphor was changed as shown in Table 7.

[Evaluation 8 with Screen / Sensitive Material] In the same manner as in Evaluation 1, the sensitivity and the crossover were evaluated by combining the screen and the sensitive material (Sample 2). The results are shown in Table 7.

[0235]

[Table 7]

As is clear from Table 7, the fluorescent dye according to the present invention exhibited the effect even when the Gd ₂ O ₂ S: Tb phosphor had various Tb activation amounts. It can be seen that the effect of the fluorescent dye is large when the Tb activation amount of the phosphor is in the range of 0.001 to 0.02.

[Example 8] <Preparation of radiation intensifying screen N1> 1) Production of support with carbon black-containing undercoat layer 40 g of carbon black powder and an acrylic binder resin (manufactured by Dainippon Ink and Chemicals, Inc., 80 g of trade name: Chris coat P1018GS) was added to methyl ethyl ketone and mixed and dispersed to prepare a coating liquid for undercoat layer having a viscosity of 3PS. This coating solution was uniformly applied onto a 250 μm thick black polyethylene terephthalate support (manufactured by Toray Industries, Inc., trade name: Lumirror X-30) using a doctor blade and dried to form a carbon black-containing undercoat layer. A support was obtained. The undercoat layer has a thickness after drying of 20 μm,
It had a sufficient light-shielding property and a high surface smoothness.

2) Production of phosphor sheet Terbium activated gadolinium oxysulfide phosphor (Gd ₂ O ₂
S: Tb, Tb activation amount: 0.003, average particle size: 2 μm
(Equivalent sphere equivalent diameter by electron microscopy), coefficient of variation of particle size distribution: 55%, 250 g of polyvinyl butyral binder resin as solid content, and epoxy binder resin (produced by Yuka Shell Epoxy Co., Ltd., product) Name: Epikote 1001) 1 g was added to methyl ethyl ketone,
Further, fluorescent dye No. 20 mg of 25 was added and dispersed by a promera mixer to prepare a phosphor layer coating solution having a viscosity of 20 PS (25 ° C.). This coating solution was applied onto a temporary support (a polyethylene terephthalate sheet previously coated with a silicone-based release agent) and dried to form a phosphor layer. This phosphor layer was peeled off from the temporary support to obtain a phosphor sheet (thickness: 125 μm).

3) Providing a phosphor sheet on the undercoat layer 1) The phosphor sheet of 2) was overlaid on the surface of the support with the undercoat layer, and pressure was 400 kgw / cm ^{2 with} a calender roll.
Pressure was applied under the condition of a temperature of 80 ° C. to form a phosphor layer on the undercoat layer. The thickness of the obtained phosphor layer was 105 μm, and the volume filling rate of the phosphor particles in the phosphor layer was 68%. In this way, a radiation intensifying screen N1 including the support, the undercoat layer and the phosphor layer was produced.

<Production of Radiation Intensifying Screen N2> A radiation intensifying screen was obtained in the same manner as in the production of the radiation intensifying screen N1, except that the thickness of the phosphor layer was changed to 135 μm. Next, a surface protective layer was provided on the surface of the phosphor layer of this screen in the same manner as in Example 1 to prepare a radiation intensifying screen N2 comprising a support, an undercoat layer, a phosphor layer and a surface protective layer.

[Evaluation of Screen 9] The obtained screen and commercially available AD-Mammo-Fin for comparison
e, AD-Mammo-Medium screens (all manufactured by Kasei Optonix Co., Ltd.) were evaluated as follows.

(Measurement of sensitivity and gradation) Screen and AD-
M single-sided photosensitive material (manufactured by Fuji Photo Film Co., Ltd.) was combined, and exposure was performed by an X-ray source in the same manner as in Evaluation 1 except that the water-sensitive voltage was 50 kVp and no water filter was used. After that, with an automatic developing machine (trade name: FPM5000) manufactured by Fuji Photo Film Co., Ltd., using a RD-3 developing solution and a Fuji-F fixing solution manufactured by the same company, a developing temperature of 35 ° C., Dry
Development processing was performed for 90 seconds to dry. The sensitivity was determined by measuring the density of the obtained sample and determining the X-ray exposure dose which gives an optical density of fog +1.0. The sensitivity is expressed as the reciprocal of the X-ray exposure amount,
The sensitivity of the screen was set to 100 and expressed as a relative value. Further, the gradation connecting the points of fog +0.25 and fog +2.0 was obtained.

(Measurement of Sharpness) In order to measure the sharpness, a rectangular chart for MTF measurement (made of tin, thickness: 30 μm)
m, spatial frequency: 0 lines / mm to 10 lines / mm). Mo target 26kVp 30 for X-ray source
A μm thick Mo and acrylic 4 cm phantom was used as a filter. After that, development processing similar to the measurement of sensitivity was performed, and CTF was determined in the same manner as in Evaluation 4. Sharpness is 2
Expressed as a value in lp / mm, AD-M sensitive material / AD-Mam
The value on the mo-Fine screen was set to 100 and expressed as a relative value. The results obtained are shown in Table 8.

[0244]

[Table 8]                                   Table 8     ───────────────────────────────────             Sensitive material Screen sensitivity Gradation Sharpness                                                               (CTF)     ───────────────────────────────────   Example AD-M N1 106 4.25 103           AD-M N2 142 4.2 85     ───────────────────────────────────   Comparative Example AD-M AD-Mammo-Fine 100 4.2 100           AD-M AD-Mammo-Medium 140 4.2 77     ───────────────────────────────────

As is clear from Table 8, the screens N1 and N2 of the present invention had higher sensitivity and sharpness than the commercially available screens. Therefore, it can be seen that it can be preferably used in a mammography system.

[Evaluation of Screen 10] Evaluation was carried out in the same manner as in Evaluation 9 using the photosensitive material L described in Example 1 of Japanese Patent Application No. 8-342636 instead of the AD-M single-sided photosensitive material. The same preferable result as in Table 8 was obtained.

[Example 9] 250 g of terbium-activated gadolinium oxysulfide phosphor, polyurethane binder resin (Pandex T5265M) 6
g, epoxy binder resin (Epicoat 1001)
1 g, and isocyanate compound (Coronate HX)
Radiation intensifying screens E, F, G of Example 4 except that the coating liquid for forming a phosphor layer was prepared by changing to 0.25 g.
Radiation intensifying screens E2 and F in the same manner as H and I
2, G2, H2, I2 were created. The volume filling factor of the phosphor particles in the phosphor layer was the same as that of the radiation intensifying screens E, F, G, H, and I, respectively. In addition, these radiation intensifying screens were combined with the light-sensitive material samples 10, 11, 12 and evaluated in the same manner as in Examples 4 and 5, and similarly good results were obtained.

[0248]

INDUSTRIAL APPLICABILITY The radiation intensifying screen using the terbium-activated gadolinium oxysulfide phosphor containing the specific fluorescent dye or fluorescent pigment of the present invention has a high sensitivity and an image having a high sharpness due to the reduction of crossover. Can be given.

[Brief description of drawings]

FIG. 1 is a graph showing an emission spectrum of screen B to which the fluorescent dye of the present invention is added.

FIG. 2 is a graph showing an emission spectrum of a normal screen Z in which no fluorescent dye is added.

FIG. 3 is a graph showing an emission spectrum of a screen X to which a yellow absorbing dye is added for comparison.

FIG. 4 is a graph showing an emission spectrum when screen B is excited by light having a wavelength of 417 nm.

FIG. 5 is a graph showing a spectral sensitivity spectrum of a silver halide photosensitive material (Sample 1).

FIG. 6 is a graph showing an excitation spectrum (absorption spectrum of a fluorescent dye) when the screen B is made to emit light at a wavelength of 520 nm.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-9-21899 (JP, A) JP-A-9-133798 (JP, A) JP-A-6-230524 (JP, A) JP-A-63- 101840 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G21K 4/00

Claims (7)

(57) [Claims] 1. A radiographic intensifying screen having at least one layer of the phosphor layer on a support, the fluorescent body layer is made of terbium activated gadolinium oxysulfide phosphor, and intensifying screen light emission of the phosphor 500 out of the light
absorbs light having a peak in the wavelength region on the shorter wavelength side than nm , and has a wavelength of at least 10 nm longer than the wavelength of the peak.
Light emission on the long side and in the wavelength range of 490 to 600 nm
A radiographic intensifying screen containing a fluorescent dye or a fluorescent pigment that emits light having a peak . 2. A fluorescent dye or pigment is 500 nm.
Radiographic intensifying screen of claim 1, wherein the benzalkonium that having a light absorption peak in the wavelength region of shorter wavelength side. 3. The fluorescent dye or pigment is 400 to 4
Has a light absorption peak in the wavelength region of 90 nm, and
The radiographic intensifying screen according to claim 1, which has an emission peak in a wavelength range of 0 to 600 nm. 4. The radiographic intensifying screen according to claim 1, wherein the fluorescent dye or fluorescent pigment has a full width at half maximum of 100 nm or less. 5. A fluorescent dye or fluorescent pigment is a carbocyanine dye, a xanthene dye, a triarylmethane dye,
The radiation intensifying screen according to any one of claims 1 to 4, which is a coumarin dye, a phthalimide compound, a naphthalimide compound, a diketopyrrolopyrrole compound and / or a perylene compound. 6. The radiation intensifying screen according to claim 1, wherein a fluorescent dye or fluorescent pigment is contained in the phosphor layer. 7. The radiation intensifying screen according to claim 1, wherein the activation amount of terbium in the terbium activated gadolinium oxysulfide phosphor is 0.001 to 0.02 mol per mol of gadolinium.