JP7302258B2 - scintillator panel - Google Patents

Description

The present invention relates to a scintillator panel.

Conventionally, radiographic images using films have been widely used. However, since radiographic images using film are analog image information, in recent years, digital radiation detectors such as computed radiography (CR) and flat panel detectors (FPD) have become available. It has been developed, and radiation images are used in a wide range of fields such as medical applications and non-destructive inspection applications.

In FPDs, scintillator panels are used to convert radiation into visible light. The scintillator panel has a phosphor layer having an X-ray phosphor such as gadolinium oxysulfide or cesium iodide on a support, and the phosphor emits visible light in response to irradiated radiation. Radiation information is converted into digital image information by converting the emitted light into an electric signal using a TFT or CCD. By efficiently converting radiation into digital image information, it is possible to take images with a low dose, so in medical applications it is possible to reduce the exposure dose of subjects, etc., and in non-destructive inspection applications it is possible to shorten the inspection time. . Therefore, improvements in brightness and sharpness are required.

As a technique for improving the sharpness of a scintillator panel, for example, in an intensifying screen having a support and a phosphor layer composed of an X-ray phosphor and a binder formed on the support, The weight ratio of the binder/the X-ray phosphor is 1/25 to 1/9, and the filling rate of the X-ray phosphor in the phosphor layer is 60 to 70%. Sensitive paper has been proposed (see, for example, Patent Document 1). However, in such a technique, there is a problem that it is difficult to achieve both sharpness and adhesion strength between the support and the adhesion strength between the phosphor layer and the support.

As another technique for improving the brightness and sharpness of a scintillator panel, for example, a radiographic image forming assembly comprising a silver halide photographic light-sensitive material and a radiographic intensifying screen on one side of a support, wherein the radiographic intensifying screen contains a phosphor. The weight ratio of the binder to the phosphor in the layer is 0.1% or more and 3.0% or less, the phosphor filling rate is 65% or more, and the average particle size of the phosphor is 0.3 μm or more and 7 μm or less, and _γ1 of the characteristic curve of the radiographic image is 1.8 or more and 2.3 or less (see, for example, Patent Document 2), or a support dispersed in a binder In the radiographic image conversion panel having a stimulable phosphor layer containing a stimulable phosphor, the sum of the acid value and hydroxyl value of the binder is 8 mgKOH/g or more (for example, Patent Document 3 ) have been proposed. However, even with this technology, it is still difficult to achieve both the high brightness and sharpness demanded in recent years and the adhesion strength to the support. In addition, in the formation of the phosphor layer, coating defects such as coating streaks and cissing and film thickness fluctuations are likely to occur, and there is a problem in film thickness uniformity.

On the other hand, as a method for uniforming the film thickness distribution, a stimulable phosphor layer coating liquid containing an acrylic leveling agent is applied in the method for manufacturing a radiation image conversion panel having a stimulable phosphor layer. A method (see, for example, Patent Document 4) has been proposed. However, even with this technique, the film thickness uniformity is still insufficient, and it is difficult to achieve both brightness and sharpness and adhesion strength to the support.

JP-A-3-196036 JP-A-10-268481 JP-A-2002-296399 Japanese Patent Application Laid-Open No. 2006-126028

An object of the present invention is to provide a scintillator panel having a phosphor layer with excellent film thickness uniformity, brightness, sharpness, and adhesion strength to a support.

In order to solve the above problems, the present invention mainly has the following configurations.
A scintillator panel having a phosphor layer containing an X-ray phosphor powder and a binder resin on a support, wherein the weight average molecular weight (Mw) of the binder resin is in the range of 700,000 to 2,000,000. , the volume ratio of the X-ray phosphor and the binder resin in the phosphor layer (X-ray phosphor: binder resin) is 85: 15 to 97: 3, and the binder resin is represented by the general formula (1) described later A scintillator panel containing an acrylic resin having a structure represented by

The scintillator panel of the present invention is excellent in the uniformity of the film thickness of the phosphor layer, excellent in brightness and sharpness, and excellent in adhesion strength to the support.

1 is a cross-sectional view schematically showing an example of the configuration of a radiation detector using the scintillator panel of the present invention; FIG. FIG. 2 is a cross-sectional view schematically showing an example of a support that is suitably used for the scintillator panel of the present invention; FIG. 4 is a cross-sectional view schematically showing another example of a support that is suitably used for the scintillator panel of the present invention; 1 is a cross-sectional view schematically showing an example of a scintillator panel of the present invention; FIG. FIG. 4 is a cross-sectional view schematically showing another example of the scintillator panel of the present invention;

The scintillator panel of the present invention has a phosphor layer containing an X-ray phosphor on a support. Preferred configurations of the scintillator panel and the radiation detector using the scintillator panel of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a radiation detector using the scintillator panel of the present invention. A radiation detector 1 has a scintillator panel 2 , a highly transparent adhesive layer 6 , a photodiode substrate 3 and a power supply section 9 . The scintillator panel 2 has a phosphor layer 5 on a support 4 . The phosphor layer 5 absorbs the irradiated radiation energy and emits electromagnetic waves with wavelengths in the range of 300 to 800 nm, that is, light ranging from ultraviolet to infrared light centering on visible light.

The photodiode substrate 3 has, on a substrate 8, a photoelectric conversion layer and an output layer 7 in which pixels having photodiodes and TFTs are two-dimensionally arranged. However, for convenience of illustration, the downward direction on the paper surface of FIG. 1 corresponds to the upward direction in the above description.

The light emitting surface of the scintillator panel 2 and the photoelectric conversion layer and output layer 7 of the photodiode substrate 3 are partially or entirely adhered via a highly transparent adhesive layer 6 . The emitted light of the phosphor that has reached the photoelectric conversion layer is photoelectrically converted in the photoelectric conversion layer and the output layer 7 and output.

The support constituting the scintillator panel of the present invention preferably has a reflectance of 80% or more in the visible light region, so that the light emitted from the phosphor layer can more efficiently reach the photodiode side. More preferably, the reflectance of the support for visible light is 90% or more. In the present invention, as an index of reflectance in the visible light region, attention is focused on reflectance at a wavelength of 550 nm, which is the main peak of visible light emitted by general X-ray phosphors. That is, the reflectance of the support at a wavelength of 550 nm is preferably 80% or more, more preferably 90% or more.

Here, the reflectance of the support means the relative reflectance when the reflectance of the barium sulfate white plate is 100%. The reflectance of the support can be measured by the SCI mode of a spectrophotometer (for example, "CM-2002" manufactured by Konica Minolta, Inc.).

Radiation emitted from the X-ray source passes through the support after passing through the subject and is converted into visible light in the phosphor layer, so the support preferably has high radiation transparency. Materials constituting the support include, for example, highly radiolucent resins such as cellulose acetate, polyester, polyamide, polyimide, triacetate and polycarbonate, and carbon fiber reinforced resins containing these and carbon fibers. You may use 2 or more types of these. Among them, it is preferable to use polyester as a main component from the viewpoint of reflectance, strength and heat resistance. Here, the "main component" in the present invention means a component of 50% by mass or more. A white polyester containing polyester as a main component and materials having different refractive indices is more preferable.

A polyester is a condensation polymer of a diol and a dicarboxylic acid. Examples of diols include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, trimethylene glycol and tetramethylene glycol. Examples of dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, adipic acid, and sebacic acid. Examples of polyester include polyethylene terephthalate (PET), polytetramethylene terephthalate (PBT), polyethylene-p-oxybenzoate, poly-1,4-cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate ( PEN) and the like.

Examples of materials with different refractive indices include white pigments such as zinc oxide, zirconium oxide, titanium oxide, gadolinium oxide, gadolinium oxysulfide, and ceramic particles such as high refractive index glass.

Since the support preferably has high radiotransmittance, it preferably does not contain elements of period 6 or higher in the periodic table of compounds, and more preferably does not contain elements of period 5 or higher. In particular, a support containing an element composed of the fourth period or less is preferable because it has high radiotransmittance. In the present invention, the term "free of high-period elements" means that the content of high-period elements in the support is less than 0.1% by mass.

From the viewpoint of reducing the weight of the scintillator panel, the thickness of the support is preferably 2.0 mm or less, more preferably 1.0 mm or less, and even more preferably 0.5 mm or less. On the other hand, from the viewpoint of improving the elastic force of the support, the thickness of the support is preferably 0.05 mm or more. The thickness of the support in the present invention is determined by using a scanning electron microscope (for example, field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.) after taking out the cross section of the support using a microtome. , 10 points each, and the average thickness can be measured.

The support preferably has a low volumetric specific gravity from the viewpoint of weight reduction and radiation transparency of the scintillator panel. Specifically, the volume specific gravity of the support is preferably 1.2 g/cm ³ or less, more preferably 0.9 g/cm ³ or less, and even more preferably 0.7 g/cm ³ or less. On the other hand, the volume specific gravity of the support is preferably 0.5 g/cm ³ or more from the viewpoint of further suppressing the occurrence of tearing and wrinkling during the production of the support and improving the handling properties.

The support constituting the scintillator panel preferably has a laminated structure of a surface layer with a porosity of 5% or less and an inner layer with a porosity of 40 to 80%. It may have two or more inner layers, and the materials of the surface layer and the inner layer may be the same or different. By having a laminate structure of the inner layer and the surface layer, image defects can be suppressed. It is preferred to have surface layers on both sides of the inner layer. The surface layer has the function of protecting the shape of the inner layer and improving the strength of the support. It also has the effect of suppressing light diffusion through the support and further improving sharpness. By setting the porosity of the surface layer to 5% or less, the strength of the support can be improved, the occurrence of wrinkles and dents in the scintillator panel manufacturing process can be suppressed, and the handling property can be improved. Moreover, when a phosphor layer or an adhesive layer is formed on the support, the permeation of the coating liquid from the surface layer into the support can be suppressed, and the production stability of the scintillator panel can be improved. The porosity of the surface layer is more preferably 2% or less, and more preferably the surface layer has no voids. On the other hand, since the inner layer contains a large number of voids, the difference in refractive index between the material of the support and the voids and the interfaces therebetween have the effect of improving the reflectance and further improving the luminance. That is, emitted light converted from radiation into visible light can be sent to the detector side more efficiently. By setting the porosity of the internal layer to 40% or more, the luminance can be further improved. The porosity of the inner layer is preferably 50% or more. On the other hand, by setting the porosity of the inner layer to 80% or less, it is possible to improve the strength of the inner layer, suppress the occurrence of breakage and wrinkles during the production of the support, and improve the handleability. Also, warping of the scintillator panel due to thermal contraction can be suppressed. The porosity of the inner layer is more preferably 70% or less, more preferably 65% or less.

Here, the porosity of the surface layer and the inner layer means the area ratio (%) of the void portion in an arbitrary cross section of the surface layer and the inner layer. The porosity of the surface layer and the inner layer was measured by a scanning electron microscope (SEM, for example, a field emission scanning electron microscope manufactured by Hitachi, Ltd.) after polishing the cross section of the surface layer and the inner layer using a microtome or ion milling. "S-4800"), an area of 40 μm × 60 μm is observed at a magnification of 2000 times, and the area ratio of the surface layer and inner layer of the void portion found in the observation area to the cross-sectional area is calculated. can ask.

The surface layer constituting the support preferably contains a resin as a main component, and may contain a powder having a refractive index different from that of the resin as the main component. As the main component resin, polyester is preferable. Moreover, from the viewpoint of further improving the brightness of the scintillator panel, it is preferable to select a material that does not absorb emitted light as the powder. Examples of powders include organic powders and inorganic powders. Inorganic powders are preferred from the viewpoint of protecting the inner layer and further improving the strength of the support, and from the viewpoint of the difference in refractive index from the resin that is the main component. Examples of inorganic powders include powders made of high refractive index materials such as zinc oxide, zirconium oxide, titanium oxide, gadolinium oxide, gadolinium oxysulfide, and high refractive index glass; A powder made of a low refractive index material such as silicon can be used. You may contain 2 or more types of these. Among these, titanium oxide powder is particularly preferred from the viewpoint of a high refractive index.

The difference (Δn) between the refractive index of the powder contained in the surface layer and the refractive index of the resin, which is the main component, improves the reflectance of the surface layer, further suppresses light diffusion in the support, and improves sharpness. From the viewpoint of further improvement, it is preferably 0.2 or more, more preferably 0.4 or more, and even more preferably 1.0 or more. On the other hand, the refractive index difference Δn is preferably 1.4 or less, more preferably 1.2 or less, from the viewpoint of suppressing coloration by appropriately reducing the refractive indices of the resin and powder. The refractive index of the powder and resin contained in the surface layer is determined by using a microtome or ion milling to obtain a cross-section of the surface layer, and then examining the powder and resin by SEM/EDX (scanning electron microscope/energy dispersive X-ray spectroscopy) or the like. Each material of the resin can be identified and calculated from the bulk refractive index of the material in question.

Note that the sharpness can be evaluated using a sharpness called MTF (Modulation Transfer Function; one of indexes for evaluating lens performance, spatial frequency characteristics) as an index. MTF is measured by the edge method based on an image obtained by placing a radiation-impermeable lead plate on a radiation detector equipped with a scintillator panel and irradiating radiation with a tube voltage of 70 kVp from the support side of the scintillator panel. be able to.

The average particle size of the powder contained in the surface layer is preferably 0.1 μm or more from the viewpoint of improving dispersibility. On the other hand, the average particle size of the powder is preferably 1.5 μm or less, more preferably 0.5 μm or less, from the viewpoint of further suppressing light diffusion in the support and further improving sharpness.

Here, the average particle size of the powder in the present invention means the number average value of the particle sizes of 100 particles randomly selected from a two-dimensional image obtained by observing the cross section of the surface layer with an SEM. However, the particle diameter of the powder refers to the length of the longest straight line that intersects the outer edge of the powder at two points. The average particle size of the powder is determined by polishing the cross section of the surface layer using a microtome or ion milling, and then using a scanning electron microscope (for example, field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.). Then, observe an area of 25 μm × 15 μm at a magnification of 5000 times, randomly select 100 particles from the powder (particles) observed in the observation area, measure the particle size, and calculate the number average value. can be obtained by

The content of the powder in the surface layer is preferably 1 part by mass or more with respect to 100 parts by mass of the total amount of the resin, which is the main component, from the viewpoint of further suppressing light diffusion in the support and further improving sharpness. 5 parts by mass or more is more preferable, and 10 parts by mass or more is even more preferable. On the other hand, the content of the powder is preferably 30 parts by mass or less, and preferably 20 parts by mass or less with respect to 100 parts by mass of the total amount of the resin, which is the main component, from the viewpoint of improving handling properties such as resistance to cracking of the support. more preferred.

The thickness of the surface layer is preferably 1 µm or more, more preferably 3 µm or more, and even more preferably 6 µm or more, from the viewpoint of protecting the inner layer and further improving the strength of the support. On the other hand, the thickness of the surface layer is preferably 20 μm or less, more preferably 15 μm or less, from the viewpoint of further improving the transmittance of visible light and X-rays and further improving the brightness of the scintillator panel. Among the plurality of surface layers, the thickness Ts of the surface layer on the phosphor layer side and the thickness Tb of the surface layer on the opposite side may be the same or different.

Here, the thickness of the surface layer is measured using a scanning electron microscope (for example, field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.) after polishing the cross section of the support with a microtome. 10 points are observed at a magnification of 2000 times (field of view: 40 μm×60 μm), and the average value thereof is calculated.

The internal layer constituting the support preferably has a porosity of 40 to 80%. The inner layer preferably contains polyester as a main component, and by selecting a resin similar to the main component of the surface layer, the adhesion between the surface layer and the inner layer can be improved, and the strength of the support can be further improved. can be done. Moreover, deformation of the support due to the difference in linear expansion coefficient can be suppressed, and the reliability of the support can be improved. In order to maintain the shape of the voids in the inner layer of the support, it is preferable to further contain organic particles containing an organic resin.

The shape of the voids in the inner layer may be spherical, elliptical, polygonal, and the like. For example, when voids are generated by interfacial peeling of the interface between the material that is the main component of the support and an incompatible organic resin, and the voids are formed in layers by stretching and orientation, the shape of the voids is substantially Many are elliptical. Since the internal layer is stretched and oriented in the direction perpendicular to the thickness direction, the voids are short in the thickness direction of the internal layer and long in the stretching and orientation direction. In the present invention, the ratio of r2 to r1 (r2/r1), where r1 is the minor axis of the air gap and r2 is the major axis of the air gap, is preferably 2 or more from the viewpoint of further improving the luminance of the scintillator panel. On the other hand, the ratio (r2/r1) is preferably 5 or less, more preferably 4 or less, and 3 from the viewpoint of further suppressing diffusion of emitted light in the inner layer in the direction parallel to the support and further improving sharpness. 0.5 or less is more preferable. Moreover, from the viewpoint of further improving the reflectance and further improving the brightness, the minor axis r1 of the gap is preferably 0.3 μm or more. On the other hand, from the viewpoint of increasing the total number of voids to further improve reflectance and further improve luminance, the minor axis r1 is preferably 3 μm or less, more preferably 1 μm or less, and even more preferably 0.7 μm or less.

The number of voids in an arbitrary cross section of the inner layer is preferably 1/100 μm ² or more, and the emitted light entering the inner layer of the support due to interfacial reflection can be extracted more efficiently, and the luminance of the scintillator panel can be further improved. can be done. In addition, the diffusion of extracted light can be suppressed, and the sharpness can be further improved. On the other hand, the number of voids in an arbitrary cross section of the internal layer is preferably 50/100 μm ² or less, which can further improve the light reflectivity of the emitted light and further improve the luminance of the scintillator panel.

When organic particles are contained in the internal layer, the organic particles are preferably incompatible with the polyester, which is the main component of the internal layer, and have excellent dispersibility. By containing organic particles incompatible with the main component, there is an effect of generating voids due to interfacial peeling of the interface between the main component and the organic particles in the stretching step after melt-molding. Materials constituting the organic particles include, for example, resins such as poly-4-methylpentene-1, cellulose triacetate, amorphous cyclic olefins, crystalline polyolefins, and copolymers thereof. You may use 2 or more types of these. Among these, amorphous cyclic olefins, which are copolymers of ethylene and bicycloalkene, are preferred because they have a large difference in critical surface tension from polyester and are less likely to deform during stretching and orientation. The amorphous cyclic olefin refers to a cyclic olefin having a glass transition temperature of 120° C. or less as measured using a differential scanning calorimeter according to JIS K7121-1987, and showing no crystallization or melting peaks.

Examples of the shape of the organic particles include spherical, elliptical, and polygonal shapes. A spherical shape is preferable because it is preferable to suppress the contact area in order to stably and efficiently cause interfacial detachment from the material that is the main component of the inner layer at the interface of the organic particles. In addition, it may become an elliptical shape deformed in a direction parallel to the support due to the stress of the stretching/orientation process during the production of the support.

The average particle size of the organic particles is preferably 0.3 μm or more from the viewpoint of easily adjusting the short diameter r1 of the voids to the desired range described above. On the other hand, the average particle diameter of the organic particles is preferably 3.0 μm or less, more preferably 1.0 μm or less, from the viewpoint of further improving the brightness of the scintillator panel. When the organic particles become elliptical due to the stress in the stretching/orientation process, the minor axis of the ellipse is taken as the average particle diameter. The oblateness f of the ellipse is defined by the following formula, and the oblateness f calculated from the minor axis Da and the major axis Db of the organic particles is preferably 0 to 0.5.
f = (Db - Da) / Db
Here, the average particle size of the organic particles in the present invention refers to the number average value of the particle sizes of 100 or more particles randomly selected from a two-dimensional image obtained by observing the cross section of the internal layer with an SEM. However, the particle diameter of a particle refers to the length of the longest straight line that intersects the outer edge of the particle at two points. The average particle diameter of the organic particles is measured by a scanning electron microscope (SEM, for example, field emission scanning electron microscope “S-4800” manufactured by Hitachi, Ltd.) after polishing the cross section of the internal layer using a microtome or ion milling. ) to observe five regions of 40 μm × 60 μm under conditions of a magnification of 2000 times, randomly select 20 organic particles from the observed area, measure the particle size, and calculate the number average value. can be obtained by

The number of organic particles in an arbitrary cross section of the inner layer is preferably 5 particles/100 μm ² or more, and the emitted light entering the inner layer of the support due to interfacial reflection is extracted more efficiently, and the luminance of the scintillator panel is further improved. be able to. In addition, it is possible to suppress the diffusion of the extracted light and further improve the sharpness. On the other hand, the number of organic particles in an arbitrary cross section of the inner layer is preferably 50 particles/100 μm ² or less from the viewpoint of handleability such as resistance to breakage of the support.

Here, the number of organic particles in the present invention is determined by observing the cross section of the internal layer with an SEM and observing a two-dimensional image of a 40 μm × 60 μm observation area at a magnification of 2000. can be calculated by counting the number of organic particles.

The content of organic particles in the internal layer is preferably 5 to 30 mass %. When the content of the organic particles in the internal layer is 5% by mass or more, the reflectance can be further improved, and the luminance can be further improved. More preferably, the content of the organic particles is 15% by mass or more. On the other hand, when the content of the organic particles is 30% by mass or less, the strength of the support and the dispersibility of the organic particles in the inner layer can be improved. The content of organic particles is more preferably 25% by mass or less.

The thickness Tc of the internal layer is preferably 70 μm or more, more preferably 100 μm or more, from the viewpoint of further improving the reflectance and further improving the luminance of the scintillator panel. On the other hand, the thickness Tc of the inner layer is preferably 500 μm or less, more preferably 250 μm or less, from the viewpoint of suppressing X-ray absorption by the inner layer and further improving the luminance of the scintillator panel. The thickness of the inner layer in the present invention is determined by polishing the cross section of the support with a microtome and then using a scanning electron microscope (for example, a field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.). can be obtained by observing 10 points at a magnification of 250 (field of view: 500 μm×300 μm) and calculating the average value.

The voids in the inner layer of the support can be stably formed with good productivity by stretching and orienting the support during production of the support by melt extrusion molding. The number and shape of the voids in the internal layer can be adjusted within a desired range by, for example, the particle size of the organic particles, the number of filling particles, stretching and orientation conditions during production of the support, and the like. The number of voids in the inner layer can be increased by increasing the number of packed organic particles. In addition, the ratio of major axis r2 to minor axis r1 of the voids can be increased by increasing the draw ratio during production of the support.

The support preferably has an easy-adhesion layer on the surface on the phosphor layer side, so that the adhesion strength between the phosphor layer and the support can be further improved.

Examples of materials for the easy-adhesion layer include acrylic resins, epoxy resins, urethane resins, and polyester resins. You may contain 2 or more types of these. Among them, it is preferable to use a polyester resin as a main component. A polyester resin having a glass transition temperature of 10 to 80° C. is more preferred. For example, when PET is used as the support, an aromatic polyester having a residue of terephthalic acid or isophthalic acid, which has a structure similar to that of PET, is preferred. The aromatic polyester is preferably a saturated copolyester having a weight average molecular weight of 2,000 to 30,000, and more preferably an amorphous solvent-soluble saturated copolyester having a weight average molecular weight of 2,000 to 30,000. . As the non-crystalline solvent-soluble saturated copolymer polyester having a weight average molecular weight of 2,000 to 30,000, non-crystalline solvent-soluble "Nichigo Polyester" (registered trademark) manufactured by Nippon Synthetic Chemical Co., Ltd. A mold can be preferably used. The glass transition temperature of the resin can be measured using a differential thermal analyzer (for example, differential thermal balance TG8120; manufactured by Rigaku Corporation).

The easy-adhesion layer may contain powder having a refractive index different from that of the polyester resin that is the main component. By containing the powder, it is possible to further suppress light diffusion in the direction parallel to the support. The refractive index difference Δn between the polyester and the powder is preferably 0.2 or more. As the powder, an inorganic powder is preferable from the viewpoint of a difference in refractive index from the resin that is the main component of the easy-adhesion layer. Examples of the inorganic powder include those exemplified as the inorganic powder for the surface layer described above. Titanium oxide powder is particularly preferred from the viewpoint of high refractive index. Here, the refractive index of the polyester resin is measured by a refractometer (Abbe refractometer 4T; ) Atago Co., Ltd., light source: sodium D line, measurement temperature 25° C.). The refractive indices of inorganic powders are disclosed in "Inorganic Chemistry Handbook" (Gihodo), "Filler Utilization Dictionary" (Taiseisha), "Ceramic Engineering Handbook" (Japan Ceramic Society), and the like.

The thickness Tad of the easy-adhesion layer is preferably 0.03 μm or more from the viewpoint of further improving the adhesion strength between the phosphor layer and the support. On the other hand, the thickness of the easy-adhesion layer is preferably 5.0 μm or less from the viewpoint of further improving the sharpness.

FIG. 2 shows a cross-sectional view schematically showing an example of a support that is suitably used for the scintillator panel of the present invention. It has a surface layer 10 and a surface layer 12 on both sides of the inner layer 11 and further has an easy adhesion layer 13 .

FIG. 3 shows a cross-sectional view schematically showing another example of a support that is suitably used for the scintillator panel of the present invention. The support laminate 4A has an adhesive layer 14 and a backing support 15 on the support 4 and an easy-adhesion layer 13 on the side opposite to the backing support 15 side. By using the support laminate for the scintillator panel, the support becomes stiffer, so that the support can be prevented from breaking during handling, which contributes to an improvement in yield.

The backing support that constitutes the support laminate preferably has high radiation transparency. Materials constituting the backing support include, for example, highly radiolucent resins such as cellulose acetate, polyester, polyamide, polyimide, triacetate and polycarbonate, and carbon fiber reinforced resins containing these and carbon fibers.

The support and backing support constituting the support laminate are preferably made of the same material. By laminating a support and a lining support made of the same material, the stiffness of the support laminate increases, and deformation of the support laminate due to heating can be suppressed in the scintillator panel manufacturing method described below. Therefore, the film thickness uniformity of the phosphor layer can be further improved. When the support and the backing support are made of different materials, it is preferable to select materials with a small difference in thermal shrinkage.

Examples of the adhesive material forming the adhesive layer include acrylic resins, epoxy resins, urethane resins, polyester resins, and the like. Among them, an optical adhesive sheet (Optically Clear Adhesive; OCA) obtained by processing an acrylic adhesive material or the like into a sheet shape is preferable because it can be adhered at a low temperature.

Similar to the thickness of the support, the thickness of the support laminate is preferably 2.0 mm or less, more preferably 1.0 mm or less, and even more preferably 0.5 mm or less from the viewpoint of reducing the weight of the scintillator panel. The thickness of the support laminate in the present invention can be determined by using a microtome or the like to take out the cross section of the support laminate, and scanning electron microscope (for example, field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.). ”) can be used to observe each 10 locations and measure the average thickness to calculate the thickness.

The phosphor layer constituting the scintillator panel of the present invention contains an X-ray phosphor and a binder resin. Further, it may contain a dispersant, a plasticizer, a cross-linking agent, a surface treatment agent, an antistatic agent, a polymerization inhibitor, metal compound particles, and the like.

An X-ray phosphor is a substance that absorbs radiation energy and emits light ranging from ultraviolet to infrared light centering on visible light. Examples of X-ray phosphors include powders of CsI, CsBr, Gd ₂ O ₂ S (hereinafter referred to as “GOS”), CaWO ₄ , Lu ₂ O ₂ S, Y ₂ O ₂ S, La ₂ O ₂ S, and the like. mentioned. Two or more of these may be included. From the viewpoint of further improving the luminous efficiency, it is preferable that an activator is added to the X-ray phosphor. Examples of the activator include Tl, Ce, Tb, Eu, Pr, and Tm. You may use 2 or more types of these. Gadolinium oxysulfide (GOS:Tb) powder to which terbium is added as an activator is preferred because of its high luminous efficiency and chemical stability.

The average particle size of the X-ray phosphor contained in the phosphor layer is preferably 0.5 to 30 μm. When the average particle size of the X-ray phosphor is 0.5 μm or more, the conversion efficiency from radiation to visible light is further improved, and the luminance can be further improved. Also, aggregation of the X-ray phosphor can be suppressed. The average particle size of the X-ray phosphor is more preferably 3.0 µm or more, and even more preferably 4.0 µm or more. On the other hand, when the average particle size of the X-ray phosphor is 30 μm or less, the surface of the phosphor layer is excellent in smoothness, and the generation of bright spots in the image can be suppressed. The average particle size of the X-ray phosphor is more preferably 18.0 μm or less, more preferably 14.0 μm or less.

Here, the average particle size of the X-ray phosphor in the present invention refers to a particle size that is 50% of the cumulative distribution of particle sizes, and is measured using a particle size distribution analyzer (eg, MT3300; manufactured by Nikkiso Co., Ltd.). can be measured by More specifically, the X-ray phosphor is put into a sample chamber filled with water, the particle size distribution is measured after performing ultrasonic treatment for 300 seconds, and the particle size that is 50% of the cumulative distribution is taken as the average particle size. diameter.

4 and 5 show cross-sectional views of an example of the scintillator panel of the present invention. The scintillator panel shown in FIG. 4 has one phosphor layer 5 . As shown in FIG. 5, when the phosphor layer has a multi-layer structure in which the X-ray phosphors have different average particle sizes, the average particle size Dsb of the X-ray phosphor contained in the lower phosphor layer on the support side and the support It is preferable that the average particle diameter Dst of the X-ray phosphor contained in the upper phosphor layer on the opposite side of the X-ray phosphor satisfies the relationship Dsb<Dst. The smaller the average particle size of the X-ray phosphor, the more the light diffusion can be suppressed, and the larger the average particle size, the better the brightness can be improved. By satisfying the relationship Dsb<Dst, it is possible to further suppress light diffusion and further improve luminance.

The surface of the X-ray phosphor is preferably coated with metal compound particles from the viewpoint of further improving luminance. The coverage is preferably 5% or more, more preferably 20% or more. The metal compound particles may completely cover the surface of the phosphor (100% coverage). As a method of coating the surface of the X-ray phosphor with a metal compound, for example, a method of forming a phosphor layer using a phosphor paste containing the X-ray phosphor and metal compound particles in the scintillator panel manufacturing method described later. is mentioned.

The coverage rate of the X-ray phosphor with the metal compound particles is obtained by randomly selecting 20 Select X-ray phosphors, divide the perimeter by 100 for each, find the ratio (%) of the area where the metal compound exists within a range of 500 nm from the phosphor surface, and calculate from the number average value can be done. When observing the cross section of the scintillator layer, it is preferable to polish it by, for example, a mechanical polishing method, a microtome method, a CP method, a focused ion beam processing method, or the like.

As metal compounds, aluminum compounds, titanium compounds, zirconium compounds, niobium compounds and the like are preferable. More specific examples include oxides, sulfides and hydroxides of aluminum, titanium or zirconium. Zirconia and titania are preferable from the viewpoint of adjusting the refractive index of the coating film and the cured film within a desired range.

Specific examples of the metal compound particles include tin oxide-titanium oxide composite particles such as "Optolake" (registered trademark) TR-502, TR-504, TR-520; 503, TR-527, TR-528, TR-529, TR-513 and other silicon oxide-titanium oxide composite particles; Kogyo Co., Ltd.); zirconium oxide particles (manufactured by Kojundo Chemical Laboratory Co., Ltd.); tin oxide-zirconium oxide composite particles (manufactured by Catalysts & Chemicals Co., Ltd.); tin oxide particles (Kojundo Chemical Research Co., Ltd.) manufactured by the company).

The metal compound particles are preferably grafted. Here, "the metal compound particles are grafted" refers to a state in which the polymer compound is chemically bonded (grafted) to the surface of the metal compound particles via hydroxyl groups or the like present on the surface of the particles. The grafted metal compound particles (grafted particles) are partially chemically bonded to the X-ray phosphor by coating the X-ray phosphor, so that the metal compound particles are suppressed from falling off and peeling off, and the coverage rate can increase

Oxysulfide phosphors represented by GOS and the like have hydroxyl groups and/or thiol groups on their surfaces. Grafted metal compound particles (grafted particles) chemically bond with hydroxyl groups and/or thiol groups on the phosphor surface, thereby increasing the coverage of the phosphor surface.

Examples of polymer compounds to which metal compound particles are grafted include water-soluble polymer compounds such as polyethylene glycol, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, urea resin, and melamine resin; polysiloxane, polymethyl methacrylate, poly-n- Non-water-soluble polymer compounds such as butyl acrylate, polyacrylonitrile, and polylactic acid are included.

Grafting of metal compound particles can be performed, for example, by mixing metal compound particles, an alkoxysilane compound, a solvent and an acid catalyst. In this case, it is considered that the metal compound particles are grafted with polysiloxane obtained by condensation polymerization of a silanol compound obtained by hydrolyzing an alkoxysilane compound with an acid catalyst.

The binder resin has the effect of increasing the film strength of the phosphor layer and improving the film thickness uniformity by dispersing the X-ray phosphor during the formation of the phosphor layer.

Examples of binder resins include polyvinyl butyral, polyvinyl acetate, polyvinyl acetal, polyvinyl alcohol, methyl cellulose resin, ethyl cellulose resin, butyl cellulose resin, polyvinyl chloride, polyvinyl acetate, polyethylene vinyl acetate, polyvinylpyrrolidone, polyamide, polyether, Examples include polycarbonate, polyacrylamide, polystyrene, and acrylic resin. Two or more of these may be included. Among these, acrylic resins are preferred.

In the present invention, the weight average molecular weight (Mw) of the binder resin ranges from 700,000 to 2,000,000. When the weight-average molecular weight Mw of the binder resin is less than 700,000, coating streaks and cissing occur in the coating film, and the film thickness uniformity deteriorates, resulting in deterioration of the appearance and film thickness uniformity of the phosphor layer. do. In addition, the strength of the phosphor layer is lowered, and chipping and cracking of the phosphor layer are more likely to occur, resulting in lower luminance and adhesion strength to the support. Mw of the binder resin is preferably 800,000 or more. On the other hand, if the Mw of the binder resin is more than 2,000,000, the filling rate of the phosphor powder becomes low, resulting in deterioration of luminance/sharpness and bending resistance. The Mw of the binder resin is preferably 1,800,000 or less, more preferably 1,600,000 or less.

The dispersion (Mw/Mn) obtained by dividing the weight average molecular weight (Mw) of the binder resin by the number average molecular weight (Mn) is preferably 1.5 to 5.0. When the dispersion degree of the binder resin is 1.5 or more, the manufacturing yield of the binder resin can be improved. The degree of dispersion of the binder resin is more preferably 2.0 or more. On the other hand, when the dispersion degree of the binder resin is 5.0 or less, it is possible to suppress the occurrence of gelation and further improve the film thickness uniformity. The degree of dispersion of the binder resin is more preferably 4.0 or less.

Here, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the binder resin refer to polystyrene conversion values measured by the GPC method. Specifically, using a gel permeation chromatograph GPC (GPC-22) / differential refractive index detector RI (manufactured by Tosoh Corporation, model RI-8020), monodisperse polystyrene (manufactured by Tosoh Corporation) is used as a standard. It can be measured as a substance.

The glass transition temperature of the binder resin is preferably 40 to 120°C. When the binder resin has a glass transition temperature of 40° C. or higher, it is possible to suppress deformation of the scintillator panel in a high-temperature and high-humidity environment. As for the glass transition temperature of binder resin, 70 degreeC or more is more preferable. On the other hand, when the glass transition temperature of the binder resin is 120° C. or less, coloring can be suppressed and luminance can be further improved. The glass transition temperature of the binder resin is more preferably 100° C. or lower.

Here, the glass transition temperature of the binder resin can be measured using a differential thermal analyzer (for example, a differential thermal balance TG8120; manufactured by Rigaku Corporation).

The solubility parameter (SP value) δb of the binder resin is preferably 16 to 21 (J/cm ³ ) ^1/2 . When the solubility parameter δb of the binder resin is 16 (J/cm ³ ) ^1/2 or more, the solubility in organic solvents is improved, the generation of aggregates in the paste is suppressed, and the film thickness uniformity is further improved. be able to. On the other hand, when the solubility parameter δb of the binder resin is 21 (J/cm ³ ) ^1/2 or less, it is possible to suppress waviness of the support in the step of coating the phosphor paste, which will be described later, and to further improve the film thickness uniformity. can be done.

Here, δb of the binder resin is determined by pyrolysis gas chromatography (thermal desorption device: TD-100 (manufactured by Markes, Inc., GC/MS device: 7890A+5975C (manufactured by Agilent) and ¹ H-NMR ( After specifying the monomer structure constituting the binder resin and the polymerization ratio of each monomer by superconducting FT-NMR (manufactured by JEOL Ltd.), the polymer of each monomer was measured for δb by turbidity titration. can be calculated by summing the product of the measured value of and the polymerization ratio.

When an acrylic resin is used as the binder resin, a polymer or copolymer containing an acrylic monomer as a main polymerization component is preferred. Examples of acrylic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, ( meth)heptyl acrylate, octyl (meth)acrylate, isononyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, (Meth) dimethylaminoethyl acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, ( 2-propylethyl methacrylate, 2-butoxyethyl (meth)acrylate, 2-cyanoethyl (meth)acrylate, 2-(dimethylamino)ethyl (meth)acrylate, glycidyl (meth)acrylate, diethylene glycol mono ethyl (meth) acrylate, dipropylene glycol monoethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, polyethylene glycol #400 di (meth) acrylate, polypropylene glycol #400 di (meth) acrylate, tri Ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane mono(meth)acrylate, tetrapropylene glycol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth) (meth)acrylates such as acrylates and ethoxylated bisphenol A di(meth)acrylate; (meth)acrylic acids such as acrylic acid, 2-carboxyethyl acrylate, 2-(4-carboxyphenoxy)ethyl acrylate, and itaconic acid etc. You may use 2 or more types of these. Among these, those containing a carboxyl group, a hydroxyl group, an epoxy group and/or an ethylenically unsaturated bond group are preferable. It is possible to further improve the film thickness uniformity and the adhesion strength to the support.

Copolymers of these acrylic monomers with vinyl acetate, acrylonitrile, acrylamide, styrene and the like may also be used.

The acrylic resin preferably has a structure represented by the following general formula (1).

In general formula (1) above, R ^a1 and R ^x1 each independently represent hydrogen or a methyl group, R ^a2 each independently represents an alkyl group having 1 to 20 carbon atoms, and R ^x2 is hydrogen. It represents an alkyl group having 1 to 20 carbon atoms, at least a portion of which is substituted with a hydroxyl group, a carboxyl group and/or an epoxy group. Both l and n are 1 or more and indicate the ratio of each structural unit. However, l/n is 1-20. l R ^a1 and R ^a2 , n R ^x1 and R ^x2 may be the same or different, and l repeating units and n repeating units may be random or block. The number of carbon atoms in R ^a2 is preferably 1 to 6, and the number of carbon atoms in R ^x2 is more preferably 1 to 8.

In the general formula (1), one repeating unit forms the skeleton of the acrylic resin. In the n repeating units, hydroxyl groups, carboxyl groups and/or epoxy groups interact with other materials and supports forming the phosphor layer, thereby further improving the bending resistance and adhesion strength of the phosphor layer. have an effect.

In the general formula (1), the structural molar ratio l/n of each structural unit is in the range of 1-20. By setting l/n to 1 or more, it is possible to suppress deformation of the scintillator panel under a high-temperature and high-humidity environment. l/n is more preferably 3 or more. On the other hand, by setting l/n to 20 or less, the adhesion strength to the support can be further improved. l/n is more preferably 15 or less.

The volume ratio of the X-ray phosphor and the binder resin in the phosphor layer (volume of X-ray phosphor:volume of binder resin) is preferably 85:15 to 97:3. By setting the ratio of the X-ray phosphor to 85 or more, brightness and sharpness can be further improved. The volume ratio of the X-ray phosphor to the volume ratio of the binder resin is more preferably 90:10 or more, more preferably 92:8 or more. On the other hand, by setting the ratio of the X-ray phosphor to 97 or less, the film strength of the phosphor layer is increased, chipping and cracking of the phosphor layer are suppressed, and bending resistance and adhesion strength to the support are further improved. be able to. In addition, it is possible to improve the dispersibility of the X-ray phosphor during the formation of the phosphor layer and further improve the uniformity of the film thickness.

The phosphor layer preferably contains a plasticizer. By including a plasticizer, it is possible to suppress film cracking of the phosphor layer due to bending and improve bending resistance. Examples of plasticizers include triphenyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trixylyl phosphate, tricresyl phosphate, and "DAIGUARD-1000" (trade name, manufactured by Daihachi Chemical Industry Co., Ltd.). Phosphate plasticizers such as diethyl phthalate, dibutyl phthalate, bis(2-ethylhexyl) phthalate, diisononyl phthalate, diisodecyl phthalate, undecyl phthalate, tris(2-ethylhexyl) trimellitate, trimellit Phthalate plasticizers such as trisisononyl acid and 2-ethylhexyl pyromellitic acid; diethyl adipate, dibutyl adipate, bis(2-butoxyethyl) adipate (D931 (trade name, manufactured by )), bis(2-ethylhexyl) adipate, diisononyl adipate, “Adekasizer” (registered trademark) LV-808, PN-160, PN-170, PN-400, PN-446, PN-7160 (trade names , manufactured by ADEKA Co., Ltd.); epoxidized di(2-ethylhexyl) hexahydrophthalate, bis(2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate, and the like. Two or more of these may be included. Among these, phthalate ester plasticizers and adipate ester plasticizers are preferable from the viewpoint of further improving brightness, sharpness, and bending resistance. Plasticizers are more preferred, and bis(2-ethylhexyl) adipate is even more preferred.

The difference Δ(δb−δp) between the solubility parameter δp of the plasticizer and the solubility parameter δb of the binder resin is preferably 4.0 (J/cm ³ ) ^1/2 or less, and 2.0 (J/cm ³ ) ^1/2 or less is more preferable. By setting the solubility parameter difference Δ(δb−δp) between the binder resin and the plasticizer to 4.0 or less, each component in the phosphor layer can be uniformly dispersed and cracking during handling can be suppressed.

Here, δp of the plasticizer is disclosed in the Japan Rubber Association, 1977, Vol. 50, No. 10.

The freezing point Fp of the plasticizer is preferably less than -35°C, more preferably less than -50°C, and even more preferably less than -60°C. When the freezing point Fp of the plasticizer is less than −35° C., deterioration in high-temperature/low-temperature cycles can be suppressed.

Here, the Fp of the plasticizer can be measured using a differential scanning calorimeter (DSCQ100 (manufactured by TA Instruments)). The plasticizer is held at 80°C for 10 minutes, cooled to -80°C at a rate of 10°C/min, held for 10 minutes, and the melting peak temperature when the temperature is raised at a rate of 10°C/min is defined as Fp. .

The phosphor layer may further contain a cross-linking agent. By including a cross-linking agent, the adhesion between the X-ray phosphor and the binder resin can be improved, and the adhesion strength with the support can be further improved. The cross-linking agent is preferably one that reacts with the functional groups of the binder resin. When the binder resin has a hydroxyl group, a carboxyl group, an epoxy group and/or an ethylenically unsaturated bond group, etc., these groups are reacted with a cross-linking agent to form a three-dimensional cross-linked structure, which is bonded to the support. It is estimated that the adhesion strength can be further improved.

The cross-linking reaction using a cross-linking agent is preferably a thermal polymerization reaction. Examples of cross-linking agents include diisocyanate compounds, dicarboxylic acid compounds, diol compounds, diamines, and alkoxysilane compounds. Two or more of these may be included.

The phosphor layer may further contain a dispersant. The molecular weight of the dispersant is preferably less than 1000 g/mol. As the dispersant, one having a carboxyl group and/or a sulfone group is preferred. In particular, a dispersing agent having a carboxyl group at the end of the molecular structure is preferable, and it can suppress the sedimentation of the X-ray phosphor in the phosphor paste described later and lengthen the pot life. Therefore, the thickness uniformity of the phosphor layer can be further improved. Examples of dispersants having a carboxyl group at the end of the molecular structure include propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, undecylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, linolenic acid, and linoleic acid. , palmitoleic acid, oleic acid and the like. Two or more of these may be included. Among these, linolenic acid, linoleic acid, and oleic acid, which have a carboxyl group at the end of the molecular structure and are liquid at room temperature, are more preferable.

The phosphor layer may further contain a polymerization inhibitor to improve thermal stability during storage. Examples of polymerization inhibitors include hydroquinone, hydroquinone monoesters, N-nitrosodiphenylamine, phenothiazine, dibutylhydroxytoluene, p,t-butylcatechol, N-phenylnaphthylamine, 2,6-di-t-butyl-p - methylphenol, chloranil, pyrogallol and the like. Two or more of these may be included.

The phosphor layer thickness T can be appropriately set according to the X-ray quality, and is preferably 50 to 500 μm. When the phosphor layer has a laminated structure of two or more layers, the relationship between the thickness Td of the phosphor layer on the support side and the thickness Tt of the upper phosphor layer laminated on the phosphor layer is such that Tt/(Td+Tt) is 0. It is preferably in the range of 0.4 to 0.9, more preferably in the range of 0.6 to 0.9.

Examples of highly transparent adhesive layers include acrylic resins, urethane resins, and polyester resins. Among them, it is preferable to use an optical adhesive sheet (OCA), which is obtained by processing an acrylic adhesive material or the like into a sheet shape, because it can be processed at a low temperature. Examples of optical adhesive sheets include "8146-1", "8146-2", "8171-CL" (manufactured by 3M Japan), "LUCIACS" (registered trademark) CS9861US, CS9861UAS, CS9862UAS (manufactured by Nitto Denko Corporation). ) and the like.

As a method for manufacturing the scintillator panel of the present invention, for example, a phosphor paste containing an X-ray phosphor, a binder resin and, if necessary, other components is applied onto a support and heated to form a phosphor layer. and methods to do so.

Examples of the method of applying the phosphor paste include a screen printing method, an application method using a bar coater, a roll coater, a die coater, a blade coater, and the like. The scintillator panel of the present invention is preferably coated using a roll coater or a die coater because the phosphor layer is thick and has a uniform thickness. Among the die coaters, a coating method using a slit die coater can control the thickness of the phosphor layer by adjusting the ejection amount, and can accurately separate the phosphor layers having a laminated structure.

When applying using a slit die coater, the uniformity of the residence time of the phosphor paste in the manifold of the nozzle and the stabilization of the flow velocity of the phosphor paste discharged from the nozzle improve the appearance and film thickness uniformity of the phosphor layer. It is preferable for further improvement. For example, the ejection amount from the die can be stabilized by appropriately adjusting the extrusion pressure, the shape of the manifold, the slit width of the die, and the viscosity and surface tension of the phosphor paste. Using the slit width W (μm) of the die set in the application direction of the phosphor layer, the film thickness T (μm) of the phosphor paste dry film, and the solid content volume fraction V (% by volume) in the phosphor paste The coefficient A (% by volume) represented by the following formula (2) is preferably 50-200. When the coefficient A is 50 or more, the influence of wear and fine scratches on the nozzle slit portion is reduced, coating streaks are suppressed, and the film thickness uniformity is further improved. The coefficient A is more preferably 60 or more, and still more preferably 70 or more. When the coefficient A is 200 or less, it is possible to prevent the phosphor paste from dripping from the die and to apply a uniform extrusion pressure, thereby further improving the film thickness uniformity. The coefficient A is more preferably 150 or less, still more preferably 120 or less.
A=W×V/T Expression (2).

The phosphor paste may contain an organic solvent in addition to the components described above as components for forming the phosphor layer. The organic solvent is preferably a good solvent for the binder resin and optionally contained plasticizer, dispersant, and the like, and preferably has a large hydrogen bonding force. Examples of such organic solvents include ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, polyethylene glycol monobutyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether. Butyl ether, dipropylene glycol monobutyl ether acetate, ethylene glycol phenyl ether, diethylene glycol phenyl ether, isopropyl alcohol, methyl ethyl ketone, cyclohexanone, isobutyl alcohol, isopropyl alcohol, terpineol, benzyl alcohol, tetrahydrofuran, dihydroterpineol, γ-butyrolactone, dihydroterpinyl acetate , 3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butanol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, N,N-dimethylformamide, hexylene glycol and the like. Two or more of these may be included.

The difference Δ(δb−δs) between the solubility parameter δs of the organic solvent and the solubility parameter δb of the binder resin is preferably in the range of −4.0 to 1.0 (J/cm ³ ) ^1/2 . When the solubility parameter difference Δ (δb−δs) between the binder resin and the organic solvent is −4.0 (J/cm ³ ) ^1/2 or more, the dispersibility of the X-ray phosphor and the binder resin in the phosphor paste is improved. can be improved. Δ(δb−δs) is more preferably −2.0 (J/cm ³ ) ^1/2 or more. On the other hand, when the solubility parameter difference Δ(δb−δs) between the binder resin and the organic solvent is 1.0 (J/cm ³ ) ^1/2 or less, the uneven distribution of the X-ray phosphor and the binder resin in the phosphor paste causes The occurrence of coating streaks can be further suppressed, and the film thickness uniformity can be further improved. Δ(δb−δs) is more preferably 0 (J/cm ³ ) ^1/2 or less.

The surface tension of the organic solvent is preferably 20-35 mN/m. When the surface tension of the organic solvent is 20 mN/m or more, paste dripping in slit die coating can be suppressed. The surface tension of the organic solvent is more preferably 25 mN/m or more. On the other hand, when the surface tension of the organic solvent is 35 mN/m or less, the phosphor paste tends to wet and spread on the surface of the support, and the film thickness uniformity can be further improved.

Here, the solubility parameter δs and surface tension of organic solvents are disclosed in "Solvent Handbook" (Kodansha Scientific) and "Polymer Handbook" (Wiley-International).

The viscosity of the phosphor paste at 25° C. is preferably 1 to 100 Pa·s. When applying using a slit die coater, it is preferably 2 to 30 Pa·s.

It is preferable to form the phosphor layer by heating and drying the phosphor paste coating film. Drying methods include, for example, hot air drying and IR (infrared) drying. When the phosphor paste coating film is dried, the phosphor paste is heated to reduce the phosphor paste viscosity. Therefore, the phosphor, which is a relatively high specific gravity material, settles in the phosphor paste, and the packing density of the phosphor in the phosphor layer can be increased. The method of heating and drying the phosphor paste coating film includes a first step of increasing the amount of residual organic solvent in the phosphor paste coating film to more than 40%, and a second step of making the remaining amount of organic solvent in the phosphor paste coating film less than 5%. It is preferred to have two steps. The heating temperature in the first step is preferably 35 to 80° C., and the heating time is preferably 10 to 30 minutes. The heating temperature in the second step is preferably 35 to 120° C., and the heating time is preferably 120 to 800 minutes.

A method for manufacturing a radiation detector using the scintillator panel of the present invention will be described using the configuration shown in FIG. 1 as an example. It is preferable to bond the photodiode substrate 3 and the scintillator panel 2 together with a highly transparent adhesive layer 6 interposed therebetween. The highly transparent adhesive layer 6 may be formed on the scintillator panel 2 side, or may be formed on the photodiode substrate 3 side. The former example will be described in more detail below. First, a highly transparent adhesive layer 6 is formed on the surface of the phosphor layer 5 formed by the method described above. For example, when an optical adhesive sheet is used as the highly transparent adhesive layer 6, it is preferable to peel off the release film on one side and attach the exposed optical adhesive sheet to the surface of the phosphor layer 5 if a release film is provided. . Next, by peeling off the other release film and bonding it to the photodiode substrate 3, the radiation detector 1 can be obtained. If necessary, heat and pressure may be applied. However, thermal contraction of the scintillator panel 2 and photodiode substrate 3, deformation of the support 4, and generation of air bubbles due to volatile components such as residual organic solvent are suppressed to improve the yield. From the point of view, the heating temperature is preferably 120° C. or less.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these.

First, the materials used in each example and comparative example are shown below. The properties of each material were measured by the following methods.

(Average particle size of X-ray phosphor)
An X-ray phosphor is put into a water-filled sample chamber of a particle size distribution analyzer (MT3300; manufactured by Nikkiso Co., Ltd.), subjected to ultrasonic treatment for 300 seconds, and then the particle size distribution is measured. % was taken as the average particle size.

(Specific gravity of X-ray phosphor)
The values described in "Phosphor Handbook" (Phosphor Society) were used.

(Glass transition temperature of binder resin)
About 10 mg of the binder resin was weighed, and an aluminum pan and a pan cover were used to measure the temperature from 20° C. to 10° C./min in a nitrogen atmosphere with a differential thermal analyzer (differential differential thermal balance TG8120; manufactured by Rigaku Corporation). The glass transition temperature was measured when the temperature was raised at a rate.

(Weight average molecular weight (Mw) and number average molecular weight (Mn) of binder resin)
A resin solution obtained by dissolving 2.5 mg of a binder resin in 5 mL of tetrahydrofuran was measured using a gel permeation chromatograph GPC (GPC-22) and a differential refractive index detector RI (manufactured by Tosoh Corporation, model RI-8020). Mw and Mn were measured using polystyrene (manufactured by Tosoh Corporation) as a standard material. As the GPC column, two TSKgel GMHxl (manufactured by Tosoh Corporation) and one G2500Hxl (manufactured by Tosoh Corporation) were connected, and tetrahydrofuran solvent was passed at a flow rate of 1.0 mL/min.

(SP value of binder resin)
Using pyrolysis gas chromatography (thermal desorption device; TD-100 (manufactured by Markes Co., Ltd., GC/MS device; “7890A; 5975C (manufactured by Agilent Co., Ltd.))”, the binder resin is heated to 500 ° C. After that, mass spectrometry was performed through a capillary separation column to identify the monomer structure that constitutes the binder resin.In addition, ¹ H-NMR (superelectric FT-NMR (JEOL Ltd. ) made)) measurement, the composition ratio of the monomers constituting the binder resin was calculated.

The SP value of the binder resin was calculated by measuring δb for each monomer polymer by turbidimetric titration, and summing the product of each measured value and the polymerization ratio.

(Fp of plasticizer)
Using a differential scanning calorimeter (DSCQ100 (manufactured by TAInstruments Co., Ltd.)), the plasticizer was held at 80 ° C. for 10 minutes, cooled to -80 ° C. at a rate of 10 ° C./min, held for 10 minutes, and held for 10 minutes. The melting peak temperature when the temperature was raised at a rate of °C/min was defined as Fp.

(Raw material for phosphor paste)
X-ray phosphor powder 1: Gd ₂ O ₂ S: Tb (manufactured by Nichia Corporation: average particle diameter 10 μm, specific gravity 7.3 g/cm ³ )
X-ray phosphor powder 2: Gd ₂ O ₂ S: Tb (manufactured by Nichia Corporation; average particle diameter 7 μm, specific gravity 7.3 g/cm ³ )
X-ray phosphor powder 3: Gd ₂ O ₂ S: Tb: Tb (manufactured by Nichia Corporation; average particle size 4 μm, specific gravity 7.3 g/cm ³ ))
Binder resins A1 to A7, A9 to A10, B-1 to B-3: Acrylic resins shown in Tables 1 and 2 Polyvinyl butyral resin: "S-lec" (registered trademark) SV-05 (manufactured by Sekisui Chemical Co., Ltd.: weight Average molecular weight 110,000, glass transition temperature 71°C, specific gravity 1.1 g/cm ³ )
Polyester resin: "Vylon" (registered trademark) 630 (manufactured by Toyobo Co., Ltd.: weight average molecular weight 23,000, glass transition temperature 7°C, specific gravity 1.3 g/cm ³ )
Polyurethane resin: “Nipporan” (registered trademark) 2304 (manufactured by Tosoh Corporation: weight average molecular weight of 25,000, glass transition temperature of −23° C., specific gravity of 1.2 g/cm ³ )
Plasticizer 1: dibutyl phthalate (freezing point −35° C., SP value 19.1 (J/cm ³ ) ^1/2 , specific gravity 1.05 g/cm ³ )
Plasticizer 2: Bis(2-ethylhexyl) phthalate (freezing point −50° C., SP value 18.2 (J/cm ³ ) ^1/2 , specific gravity 0.986 g/cm ³ )
Plasticizer 3: bis(2-ethylhexyl) adipate (freezing point −70° C., SP value 17.4 (cal/cm ³ ) ^1/2 , specific gravity 0.927 g/cm ³ )
Metal compound particles: Silicon oxide-titanium oxide composite particles “Optlake” (registered trademark) TR-527 (manufactured by Catalysts & Chemicals Co., Ltd.; average particle diameter 15 nm, refractive index 2.50, titanium oxide particles 20% by mass)
Dispersant: oleic acid (molecular weight 282.5 g/mol, specific gravity 0.985 g/cm ³ )
Organic solvents 1 to 5: Organic solvents shown in Table 3.

(Preparation of Grafted Particles)
40 g of methyltrimethoxysilane, 20 g of phenyltrimethoxysilane, 20 g of dimethyldimethoxysilane, 20 g (solid content) of metal compound particles: silicon oxide-titanium oxide composite particles ("Optolake" (registered trademark) TR-527 ( Catalyst Kasei Kogyo Co., Ltd.; average particle size: 15 nm, refractive index: 2.50, titanium oxide particles: 20% by mass) and 230 g of propylene glycol monomethyl ether acetate were placed in a reaction vessel and stirred to form a 1% by mass phosphoric acid aqueous solution. 30 g was added dropwise so that the reaction temperature did not exceed 40° C. After completion of the dropwise addition, a distillation apparatus was attached to the reaction vessel, and the resulting solution was heated and stirred at a bath temperature of 105° C. for 2.5 hours to hydrolyze The reaction was allowed to proceed while distilling off the generated methanol, followed by further heating and stirring at a bath temperature of 115° C. for 2 hours and then cooling to room temperature to obtain a solution of grafted metal compound particles (grafted metal compound particles, solid 30% by weight) was obtained.

(Preparation of phosphor paste)
Each raw material shown in Tables 4 to 6 is mixed so as to have the blending ratio shown in Tables 4 to 6, and a planetary stirring and defoaming device (“Mazerustar” (registered trademark) KK-400; manufactured by Kurashiki Boseki Co., Ltd.) was stirred at 200 rpm for 30 minutes to deaerate, to obtain phosphor pastes P-1 to P-16 and P-21 to P-24. In P1-13, 15-16, and 22-24 containing grafted particles, the surface of the X-ray phosphor was coated with the grafted particles.

Further, 84.8 g of X-ray phosphor powder 1 and 2.9 g of polyester resin were added to 12.3 g of organic solvent 5 and dispersed by a propeller mixer to prepare phosphor paste P-25.

In addition, 84.7 g of X-ray phosphor powder, 2.4 g of polyurethane resin, and 0.85 g of an acrylic leveling agent (manufactured by Kusumoto Kasei Co., Ltd.: "Disparon" (registered trademark) 1980-50) were added to 12 Phosphor paste P2-6 was prepared by adding to 0.05 g of organic solvent 5 and dispersing with a propeller mixer.

However, the viscosity of the phosphor paste obtained by the above method was measured using a B-type viscometer with a digital operation function (manufactured by Brookfield, DV-II+Pro) at a temperature of 25° C. and a rotation speed of 3 rpm.

(Preparation of supports 1 and 2)
As a component constituting the inner layer of the support, a master pellet for the inner layer composed of a mixture of a copolymerized polyester resin and organic particles made of a resin incompatible with the copolymerized polyester resin. used. In addition, as a component constituting the surface layer of the support, surface layer master pellets were used in which 18 parts by mass of titanium oxide (average particle size 0.3 μm) was added to 100 parts by mass of a copolymerized polyester resin.

These pellets were each supplied to two extruders heated to 280° C. and formed into a sheet with a die. Further, the unstretched film obtained by cooling and solidifying this sheet with a cooling drum having a surface temperature of 20°C was stretched 2.9 times in the longitudinal direction while being heated to 90°C, and cooled with a group of rolls at 25°C. Subsequently, while holding both ends of the support with clips, the support was led to a tenter and stretched 3.7 times in the direction perpendicular to the longitudinal direction (width direction) in an atmosphere heated to 120°C. Then, it was heat-set at 190° C. in a tenter, cooled to room temperature, and wound up as a biaxially stretched roll-shaped support.

As a component constituting the adhesive layer, a coating liquid (adhesive layer 1) made of a copolymer polyester resin composed of terephthalic acid/isophthalic acid/ethylene glycol/neopentyl glycol (25/25/25/25 mol%), oxidized to the resin A coating liquid (adhesive layer 2) was prepared by adding 15% by mass of titanium particles (average particle size: 0.24 μm). An adhesive layer was formed by applying a coating liquid for an adhesive layer to the roll-shaped support obtained by the above method using a microgravure plate/kiss coat and drying at a temperature of 100°C. The roll-shaped support on which the adhesive layer was formed was cut into 500 mm squares to obtain supports 1 and 2 below.
Support 1: A structure in which surface layers (porosity 0.1%, thickness 10 μm) are laminated on both sides of an inner layer (porosity 60%, thickness 220 μm, number of organic particles 20/100 μm ² ). A white polyester support having an adhesive layer 1 having a thickness of 3 μm on one side. Reflectance of 97% at a wavelength of 550 nm.
Support 2: A structure in which surface layers (porosity of 0.1%, thickness of 10 μm) are laminated on both sides of an inner layer (porosity of 65%, thickness of 220 μm, number of organic particles: 30/100 μm ² ). A white polyester support with a 4 μm thick adhesive layer 2 on one side. Wavelength 550 nm reflectance 98%.

However, the porosity of the surface layer and inner layer of the support obtained by the above method was measured by the following method. First, the cross section of the obtained support was polished using a microtome to obtain a precise cross section, and then a scanning electron microscope (Field Emission Scanning Electron Microscope "S-4800" manufactured by Hitachi, Ltd.) was observed. The surface layer was observed at a magnification of 5,000 times (field of view: 25 μm×15 μm), and the internal layer was observed at a magnification of 2,000 times (field of view: 40 μm×60 μm). Voids and portions derived from other materials were image-converted into two gradations, and the area ratio of the void portions observed in the observation region to the cross-sectional areas of the surface layer and the inner layer was calculated. The surface layer and the inner layer were each calculated for 10 areas, and the number average value was calculated.

In addition, the thickness of the surface layer and the inner layer of the support obtained by the above method can be determined by polishing the cross section of the obtained support using a microtome to obtain a precise cross section, and then using a scanning electron microscope (( Using a field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.), the surface layer was observed at a magnification of 2000 times (field of view: 40 µm × 60 µm), and the inner layer at a magnification of 250 times (field of view: 500 µm × 300 µm). Observed, the thickness of 10 points in the support surface was calculated, and the number average value was calculated.

Also, the number of organic particles contained in the inner layer of the support obtained by the above method was measured by the following method. first. A cross section of the obtained support was polished using a microtome to obtain a precise cross section, and then a scanning electron microscope (Field Emission Scanning Electron Microscope "S-4800" manufactured by Hitachi, Ltd.) was used. Observation was made under the condition of a magnification of 2000 times (field of view: 40 μm×60 μm). The number of spherical or elliptical organic particles with a particle size of 0.2 μm or more contained in the obtained image was counted.

Next, evaluation methods in each example and comparative example will be described.

1. Brightness and sharpness of scintillator panel The scintillator panel obtained in each example and comparative example was attached to a photodiode substrate (FPD, PaxScan2520V (Varian)) via a highly transparent optical adhesive layer (8171-CL (manufactured by 3M Japan)). (manufactured)) to fabricate a radiation detector. In the standard IEC62220-1 defined by the International Electrotechnical Commission (IEC), radiation with a tube voltage of 70 kVp conforming to radiation quality RQA5 for evaluating the image quality of digital imaging systems is irradiated from the substrate side of the scintillator panel, and the brightness of the scintillator panel , sharpness was detected by FPD. The luminance was calculated from the slope of the graph of the incident dose and the digital value of the image. Moreover, the sharpness was calculated by the edge method, and a value of 2 cycles/mm was used. A relative comparison was made with the brightness and sharpness of Example 1 set to 100%. Regarding the luminance, those with a relative luminance exceeding 100% were evaluated as good, those with a luminance of 105% or more were evaluated as excellent, and those with a luminance of less than 100% were evaluated as unsatisfactory. Regarding the sharpness, those with a relative sharpness exceeding 100% were evaluated as good, those with a sharpness of 105% or more were evaluated as excellent, and those with less than 100% were evaluated as poor.

2. Image Quality of Scintillator Panel From the results of evaluating the brightness and sharpness of the scintillator panel, as a comprehensive image quality evaluation, A (Excellent) indicates that both brightness and sharpness are excellent, and neither brightness nor sharpness is defective. , were evaluated as B (Good), and those with either luminance or sharpness as poor were evaluated as C (Poor).

3. Adhesion Strength of Phosphor Layer to Support Adhesive tape having an adhesive strength of 5 N/25 mm was adhered to the phosphor layer of the scintillator panel obtained in each example and comparative example, and the tape was applied while maintaining a peeling angle of 90°. It was peeled off, and the presence or absence of chipping or cracking of the phosphor layer and peeling from the support was observed. This test was repeated 50 times. A (Excellent) indicates that no chipping, cracking, or peeling of the phosphor layer is observed even after 20 peelings, B (Good) indicates that peeling of the phosphor layer is not observed after 20 peelings, and up to 5 peelings. Those in which peeling of the phosphor layer was observed were evaluated as C (Poor).

4. Bending resistance of phosphor layer The scintillator panel obtained in each example and comparative example was heated at 50 ° C. for 1 hour, cooled at -20 ° C. for 1 hour, and returned to room temperature. While being pressed against a roll having a diameter, the surface of the phosphor layer was irradiated with black light, and the presence or absence of cracks, chipping, and breakage in the phosphor layer was observed. This cycle test was repeated 50 times, and the maximum number of cycles at which no cracks, chips, or cracks were observed in the phosphor layer was taken as the adhesion strength. A (Excellent) indicates that no cracks, chips, or cracks are observed in the phosphor layer even after 20 cycles, and B (Good) indicates that no cracks, chips, or cracks are observed in the phosphor layer by 20 cycles. ), and C (Poor) when cracks, chips, or cracks were observed in the phosphor layer by 5 cycles.

5. Film Strength of Phosphor Layer Based on the evaluation results of the adhesion strength and bending resistance of the phosphor layer to the support, as a comprehensive film strength evaluation, A (Excellent) indicates that both adhesion strength and bending resistance are excellent, When neither the adhesion strength nor the bending resistance is poor, but either is good, it is evaluated as B (Good), and when either the adhesion strength or the bending resistance is poor, it is evaluated as C (Poor).

6. Coating Streaks and Repelling of Phosphor Layer The phosphor layers of the scintillator panels obtained in each example and comparative example were visually observed, and the presence or absence of coating streaks and repelling was observed.

7. Uniformity of Film Thickness of Phosphor Layer A film thickness meter (DIGIMATIC INDICATOR (“534-411-H-1” manufactured by MITUTOYO Co., Ltd.)) was used for 9 points in the plane of the scintillator panels obtained in each example and comparative example. was used to measure the thickness of the scintillator panel, the thickness of the phosphor layer at each point was calculated from the difference from the thickness of the support, and the numerical average was calculated. The value obtained by dividing the value (film thickness difference) at which the absolute value of the difference between the film thickness and the number average value of the phosphor layer at each of the nine measured points is the largest, by the film thickness (number average value) of the phosphor layer was calculated as the film thickness variation of the phosphor layer.

A (excellent) when the film thickness variation of the phosphor layer is 15% or less, B (good) when the film thickness variation of the phosphor layer is more than 15% and 25% or less, and the film of the phosphor layer A thickness variation exceeding 25% was evaluated as C (Poor).

8. Appearance of phosphor layer From the evaluation results of the film thickness uniformity of the phosphor layer and coating streaks and cissing, as a comprehensive appearance evaluation, coating streaks and cissing were not observed, and the phosphor layer thickness variation was 15%. A (Excellent) is less than or equal to A (Excellent), no coating streaks or repelling is observed, B (Good) is a phosphor layer thickness variation of more than 15% and 25% or less, and coating streaks and repelling are observed. If the film thickness variation of the phosphor layer exceeded 25%, it was evaluated as C (Poor).

9. Comprehensive Evaluation From the evaluation results of the scintillator panel and the phosphor layer, as a comprehensive evaluation, A (Excellent) is obtained when each evaluation of the image quality characteristics, film strength, and appearance of the scintillator panel is A (Excellent).・None of film strength or appearance is C (Poor), but B (Good) is B (Good). Image quality characteristics, film strength, or appearance is C (Poor). It was evaluated as C (Poor).

(Example 1)
The phosphor paste P-1 obtained by the above method is coated on the support 1 by a slit die coating method so that the slit width is 360 μm and the thickness of the phosphor layer after drying is 200 μm. A phosphor layer was formed by heating at a temperature of 70° C. for 180 minutes to obtain a scintillator panel. After 30 minutes of drying with a hot air dryer, the organic solvent residual amount was 50%.

(Examples 2-6, 11-14 , Comparative Examples 1-8, 10 )
A scintillator panel was obtained in the same manner as in Example 1, except that the phosphor pastes listed in Tables 4 to 6 were used instead of the phosphor paste P-1.

(Example 15)
The phosphor paste P-15 obtained by the above method was coated on the support 1 by a slit die coating method so that the slit width was 90 μm and the thickness after drying was 50 μm. After that, the phosphor paste P-11 obtained by the above method was coated on the phosphor paste P-15 coating film by a slit die coating method so that the slit width was 300 μm and the thickness after drying was 150 μm. A scintillator panel was obtained by heating at a temperature of 70° C. for 180 minutes using a dryer to form a phosphor layer having a two-layer structure. After 30 minutes of drying with a hot air dryer, the organic solvent residual amount was 40%.

(Example 16)
A scintillator panel was obtained in the same manner as in Example 15 except that the support 2 was used instead of the support 1.

(Example 17)
A scintillator panel was obtained in the same manner as in Example 16 except that phosphor paste P-16 was used instead of phosphor paste P-15.

(Example 18)
Two sheets of support 1 were prepared, and an optical adhesive sheet ( 8171-CL) was attached, the surface of the optical adhesive sheet was attached to the side of another support 1 on which the easy-adhesion layer was not formed, to obtain a support laminate 3. A scintillator panel was obtained in the same manner as in Example 11, except that the support laminate 3 was used instead of the support 1 .

(Example 19)
A support 1 and a support 2 were prepared, and an optical adhesive sheet (8171- CL) was attached, the surface of the optical adhesive sheet and the side of the support 2 on which the easy-adhesion layer was not formed were attached together to obtain a support laminate 4 . A scintillator panel was obtained in the same manner as in Example 11 except that the support laminate 4 was used instead of the support 1 and the phosphor layer was formed on the support 1 side of the support laminate 4 .

Tables 4 to 6 show the configuration and evaluation results of each example and comparative example.

REFERENCE SIGNS LIST 1 radiation detector 2 scintillator panel 3 photodiode substrate 4 support 4A support laminate 5 phosphor layer 6 highly transparent adhesive layer 7 photoelectric conversion layer and output layer 8 substrate 9 power supply section 10 surface layer 11 internal layer 12 surface layer 13 Easily Adhesive Layer 14 Adhesive Layer 15 Backing Support

Claims (5)

A scintillator panel having a phosphor layer containing an X-ray phosphor and a binder resin on a support, wherein the weight average molecular weight (Mw) of the binder resin is in the range of 700,000 to 2,000,000, The volume ratio of the X-ray phosphor and the binder resin (X-ray phosphor:binder resin) in the phosphor layer is 85:15 to 97:3, and the binder resin is represented by the following general formula (1): A scintillator panel containing an acrylic resin having a structure of

(In general formula (1) above, R ^a1 and R ^x1 each independently represent hydrogen or a methyl group, R ^a2 represents an alkyl group having 1 to 20 carbon atoms, and R ^x2 represents at least part of hydrogen. represents an alkyl group having 1 to 20 carbon atoms substituted with a hydroxyl group, a carboxyl group and/or an epoxy group, l and n each represent an integer of 1 or more, provided that l/n is 4 to 20 1 R ^a1 and R ^a2 and n R ^x1 and R ^x2 may be the same or different.) 2. The scintillator panel according to claim 1, wherein the volume ratio of the X-ray phosphor to the binder resin (X-ray phosphor:binder resin) in said phosphor layer is 92:8 to 96:4. 3. The scintillator panel according to claim 1, wherein said phosphor layer contains an adipate plasticizer. 4. The scintillator panel according to claim 1, wherein the phosphor layer contains grafted particles. 5. The scintillator panel according to claim 1, wherein said X-ray phosphor has hydroxyl groups and/or thiol groups on its surface.

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