WO2009139215A1

WO2009139215A1 - Scintillator panel and radiological image detector

Info

Publication number: WO2009139215A1
Application number: PCT/JP2009/054290
Authority: WO
Inventors: 成人後藤; 武彦庄子; 貴文柳多
Original assignee: コニカミノルタエムジー株式会社
Priority date: 2008-05-13
Filing date: 2009-03-06
Publication date: 2009-11-19
Also published as: JP5353884B2; JPWO2009139215A1

Abstract

A scintillator panel is provided with a radiotransparent substrate; a reflection layer arranged on the substrate; a protection layer arranged on the reflection layer; a scintillator layer arranged on the protection layer; and a humidity resistant protection layer covering the scintillator layer. The protection layer contains at least a pair of organic resins of two types having a glass transition temperature difference of 5°C or more, and has excellent storage stability.

Description

Scintillator panel and radiation image detector

The present invention relates to a scintillator panel and a radiation image detector used when forming a radiation image of a subject.

Conventionally, radiographic images such as X-ray images have been widely used for diagnosis of medical conditions in the medical field. In particular, radiographic images using intensifying screens and film systems have been developed as an imaging system that combines high reliability and excellent cost performance as a result of high sensitivity and high image quality in the long history. Used in the medical field. However, the image information is so-called analog image information, and free image processing and instantaneous electric transmission cannot be performed like the digital image information that has been developed in recent years.

In recent years, digital radiological image detection devices represented by computed radiography (CR), flat panel type radiation detectors (FPD), and the like have appeared. In these, since a digital radiographic image is directly obtained and an image can be directly displayed on an image display device such as a cathode tube or a liquid crystal panel, image formation on a photographic film is not necessarily required. As a result, these digital X-ray image detection devices reduce the need for image formation by the silver halide photography method, and greatly improve the convenience of diagnosis work in hospitals and clinics.

* Computed radiography (CR) is currently accepted in the medical field as one of the digital technologies for X-ray images. However, the sharpness is insufficient and the spatial resolution is insufficient, and the image quality level of the screen / film system has not been reached. Further, as new digital X-ray imaging techniques, for example, the magazine Physics Today, November 1997, page 24, John Laurans' paper “Amorphous Semiconductor User in Digital X-ray Imaging”, magazine SPIE Vol. 32, 1997. Thin-film transistors (TFTs) using thin-film transistors (TFTs) using a thin-film transistor (TFT) detection device (TFT), which is described in El E. Antonuk's paper “Development of a High Resolution, Active Matrix, Flat-Panel Imager with Enhanced Fill Factor”, etc. Has been developed.

In order to convert radiation into visible light, a scintillator panel made of an X-ray phosphor having a characteristic of emitting light by radiation is used. In order to improve the S / N ratio in low-dose imaging, luminous efficiency is used. It is necessary to use a high scintillator panel. In general, the scintillator panel light emission efficiency is determined by the thickness of the scintillator layer (phosphor layer) and the X-ray absorption coefficient of the phosphor. The thicker the phosphor layer, the light emitted from the phosphor layer. Scattering occurs and the sharpness decreases. Therefore, when the sharpness necessary for the image quality is determined, the film thickness is determined.

In particular, cesium iodide (CsI) has a relatively high rate of change from X-rays to visible light, and phosphors can be easily formed into a columnar crystal structure by vapor deposition. Therefore, it was possible to increase the thickness of the phosphor layer.

However, since CsI alone has a low luminous efficiency, a mixture of CsI and sodium iodide (NaI) in an arbitrary molar ratio is used for the substrate by vapor deposition as described in, for example, Japanese Patent Publication No. 54-3560. Deposited as sodium-activated cesium iodide (CsI: Na) on the substrate, and recently mixed with any molar ratio of CsI and thallium iodide (TlI) on the substrate using vapor deposition. Visible conversion efficiency is improved by performing annealing as a post-process on those deposited as (CsI: Tl) and used as an X-ray phosphor.

As another means for increasing the light output, a method for making the substrate on which the scintillator is formed reflective (for example, see Patent Document 1), a method for providing a reflective layer on the substrate (for example, see Patent Document 2), and a method for providing on the substrate. A method of forming a scintillator on a reflective metal thin film and a transparent organic film covering the metal thin film (see, for example, Patent Document 3) has been proposed, but these methods increase the amount of light obtained, but are sharp. There is a drawback that the performance is significantly reduced.

In addition, in order to improve the stability of the substrate, the reflective film, and the scintillator layer, a method using a polyimide or polyparaxylene film (see, for example, Patent Document 4), and a technology having a light absorption layer between the reflective layer and the scintillator layer ( For example, see Patent Document 5), and a radiation detector having a planarizing resin layer, a scintillator layer, a reflective layer, and a protective layer on an electrode substrate having a photoelectric conversion element has been proposed (see Patent Document 6).
Japanese Patent Publication No. 7-21560 Japanese Patent Publication No. 1-240887 JP 2000-356679 A JP 2007-279051 A JP 2008-107222 A JP 2008-215951 A

However, even when the above-described conventional technology is used, the stability of the substrate, the reflective film, and the scintillator layer is not sufficiently improved, and particularly when stored under high humidity conditions, the luminance and sharpness are deteriorated. The present invention has been made in view of the above situation, and its object is to provide a scintillator panel and a radiation image detector that are excellent in storage stability.

The above-mentioned problem according to the present invention is solved by the following means.

1. A radiation transmissive substrate, a reflective layer provided on the substrate, a protective layer provided on the reflective layer, a scintillator layer provided on the protective layer, and a moisture-resistant protective layer covering the scintillator layer A scintillator panel comprising: a protective layer containing at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

2. A radiation transmissive substrate, an intermediate layer provided on the substrate, a reflective layer provided on the intermediate layer, a protective layer provided on the reflective layer, and provided on the protective layer A scintillator panel comprising a scintillator layer and a moisture-resistant protective layer covering the scintillator layer, wherein the intermediate layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more. Scintillator panel.

3. A radiation transmissive substrate, a reflective layer provided on the substrate, a protective layer provided on the reflective layer, a scintillator layer provided on the protective layer, and a moisture-resistant protective layer covering the scintillator layer And the moisture-resistant protective layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more and has a film thickness of 12 to 60 μm. .

4. A radiation image detector comprising: a photoelectric conversion element formed on a substrate; an organic resin layer provided on the photoelectric conversion element; and a scintillator layer provided on the organic resin layer. The radiation image detector, wherein the layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

5. In a radiation image detector comprising a photoelectric conversion element formed on a substrate, a scintillator layer provided on the photoelectric conversion element, and a reflection layer provided on the scintillator layer, the reflection layer comprises: A radiation image detector comprising at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

6. In a radiological image detector comprising a photoelectric conversion element formed on a substrate, a scintillator layer provided on the photoelectric conversion element, and a moisture-resistant protective layer provided on the scintillator layer, the moisture-resistant protective layer However, a radiation image detector comprising at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more and a film thickness of 12 to 60 μm.

By the above means of the present invention, it is possible to provide a scintillator plate and a radiation image detector which are particularly excellent in storage stability with little deterioration in brightness and sharpness.

Sectional view showing schematic configuration of scintillator panel Partial enlarged sectional view of the scintillator panel The figure which shows schematic structure of the vapor deposition apparatus 61 Partially cutaway perspective view showing a schematic configuration of a radiation image detection apparatus including a scintillator panel Expanded sectional view of the imaging panel of the radiation image detection device Expanded sectional view of the imaging panel of the radiation image detector

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Intermediate layer 3 Reflective layer 4 Protective layer 5 Scintillator layer 6 Moisture-resistant protective layer 10 Scintillator panel 61 Deposition apparatus 62 Vacuum vessel 63 Boat (filled member)
64 Holder 65 Rotating mechanism 66 Vacuum pump 100 Radiation image detection device 201 Output substrate 202 Image signal output layer 203 Photoelectric conversion element 204 Organic resin layer 205 Scintillator layer 206 Reflective layer 207 Moisture resistant protective layer

Hereinafter, the present invention and its components will be described in detail.

<About the above means 1>
The present invention includes a radiation transmissive substrate, a reflective layer provided on the substrate, a protective layer provided on the reflective layer, a scintillator layer provided on the protective layer, and the scintillator layer. A scintillator panel comprising a moisture-resistant protective layer for covering, wherein the protective layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

In the present invention, a scintillator plate having excellent storage stability can be provided by including at least one set of two kinds of organic resins having different glass transition temperatures of 5 ° C. or more.

(Protective layer)
The scintillator panel of the present invention has a reflective layer provided on a substrate and a protective layer provided on the reflective layer, and at least one organic resin having a glass transition temperature of 5 ° C. or more is different from the protective layer. It is necessary to contain a set.

By including two organic resins with glass transition temperatures of 5 ° C or higher, a coating film with high Young's modulus and flexibility can be formed, handling panels under harsh conditions, and long-term storage under high humidity Stable panel performance can be obtained without occurrence of cracks or the like even if the operation is performed.

The thickness of the protective layer is preferably 0.2 to 5.0 μm, more preferably 0.5 to 4.0 μm, in view of obtaining sufficient storage characteristics and suppressing light scattering. It is particularly preferably 7 to 3.5 μm.

Specific examples of the organic resin include polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer. Polymer, polyamide resin, polyvinyl acetal, polyester, cellulose derivative (nitrocellulose, etc.), polyimide, polyamide, polyparaxylylene, styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea resin, Examples include melamine resin, phenoxy resin, silicon resin, acrylic resin, urea formamide resin, and the like.

Among these, it is preferable to use polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, nitrocellulose, polyimide, and polyparaxylylene.

The temperature of the glass transition point according to the present invention is a value obtained by (2) DSC method of JIS C 6481, and is measured using a differential scanning calorimeter (DSC method) under the condition of increasing the temperature at 20 ° C./min. It refers to the glass transition temperature obtained.

That is, the test piece is heated from room temperature at a rate of 20 ° C./min, the calorific value is measured with a differential scanning calorimeter, an endothermic curve (or exothermic curve) is created, and the endothermic curve (or exothermic curve) is 2 The extension line of the book is drawn, and the glass transition temperature (Tg) is obtained from the intersection of the 1/2 straight line between the extension lines and the endothermic curve.

The two kinds of organic resins contained in at least one pair in the protective layer are required to have a glass transition temperature different by 5 ° C. or more, but the difference in glass transition temperature is preferably 5 ° C. to 80 ° C., more preferably 20 ° C. -80 ° C, particularly preferably 30 ° C-70 ° C.

In particular, a resin having a glass transition temperature of 50 to 100 ° C. (more preferably 60 to 90 ° C.) and a resin having a glass transition temperature of −20 ° C. to 45 ° C. (more preferably a resin having a temperature of −10 ° C. to 35 ° C.). It is preferable to contain.

When these resins are used, the content of the resin having a glass transition temperature of 50 to 100 ° C. with respect to the protective layer is preferably 30% by mass to 95% by mass, and particularly preferably 50% by mass to 85% by mass.

The content of the resin having a glass transition temperature of −20 ° C. to 45 ° C. with respect to the protective layer is preferably 5% by mass to 70% by mass, and particularly preferably 15% by mass to 50% by mass.

The content of the two types of organic resins having a glass transition temperature of 5 ° C. or more with respect to the protective layer (total of the two types) is preferably 80% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.

The use ratio (% by mass) of the resin having a glass transition temperature of 50 to 100 ° C. and the resin having a glass transition temperature of −20 to 45 ° C. is preferably 30:70 to 90:10, and 50:50 to More preferably, it is 80:20.

Further, the protective layer preferably contains one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more. In this case, all except for the additives contained in the protective layer described below are all in one set. It is an organic resin.

Normally, when forming a scintillator by vapor deposition, the substrate temperature is 150 ° C. to 250 ° C., but the protective layer contains an organic resin having a glass transition temperature of −20 ° C. to 45 ° C. The protective layer effectively functions as an adhesive layer.

Solvents used for preparing the protective layer include lower alcohols such as methanol, ethanol, n-propanol and n-butanol, hydrocarbons containing chlorine atoms such as methylene chloride and ethylene chloride, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, toluene , Aromatic compounds such as benzene, cyclohexane, cyclohexanone, xylene, esters of lower fatty acids and lower alcohols such as methyl acetate, ethyl acetate, butyl acetate, ethers such as dioxane, ethylene glycol monoethyl ester, ethylene glycol monomethyl ester and the like Can be mentioned.

The protective layer according to the present invention is preferably a light absorption layer, and the maximum absorption wavelength is preferably 560 to 650 nm. The protective layer preferably contains at least one of a pigment and a dye so that the maximum absorption wavelength is in the range of 560 to 650 nm.

The protective layer preferably contains a dispersant and the like in addition to the organic resin. As a colorant having a maximum absorption wavelength between 560 and 650 nm, known ones described in various documents can be used in addition to commercially available ones.

As the colorant, those having absorption in the wavelength range of 560 to 650 nm are preferable, and as the colorant, purple to blue organic or inorganic colorants are preferably used.

Examples of purple to blue organic colorants are purple: dioxazine, blue: phthalocyanine blue, indanthrene blue, and the like. Specifically, Zabon First Blue 3G (manufactured by Hoechst), Estrol Brill Blue N- 3RL (manufactured by Sumitomo Chemical Co., Ltd.), Sumiacryl Blue F-GSL (manufactured by Sumitomo Chemical Co., Ltd.), D & C Blue No. 1 (made by National Aniline), Spirit Blue (made by Hodogaya Chemical Co., Ltd.), Oil Blue No. 1 603 (manufactured by Orient Co., Ltd.), Kitten Blue A (manufactured by Ciba-Geigy), Eisen Cachilon Blue GLH (manufactured by Hodogaya Chemical Co., Ltd.), Lake Blue A, F, H (manufactured by Kyowa Sangyo Co., Ltd.) Rhodaline Blue 6GX (manufactured by Kyowa Sangyo Co., Ltd.), Brimocyanin 6GX (manufactured by Inabata Sangyo Co., Ltd.), Brill Acid Green 6BH (manufactured by Hodogaya Chemical Co., Ltd.), Cyanine Blue BNRS (manufactured by Toyo Ink Co., Ltd.) And Lionol Blue SL (manufactured by Toyo Ink Co., Ltd.).

Examples of purple-blue-blue-green inorganic colorants include ultramarine, cobalt blue, cerulean blue, chromium oxide, and TiO ₂ —ZnO—CoO—NiO pigments, but the present invention is not limited thereto.

Preferred as the colorant is a metal phthalocyanine pigment.

Specific examples of metal phthalocyanine pigments include copper phthalocyanine. However, other metal-containing phthalocyanine pigments such as those based on zinc, cobalt, iron, nickel, and other such metals can be used as long as the maximum absorption wavelength is in the range of 570 to 650 nm.

Suitable phthalocyanine pigments may be unsubstituted or substituted (eg, with one or more alkyl, alkoxy, halogen such as chlorine, or other substituents typical of phthalocyanine pigments). The crude phthalocyanine can be prepared by any of several methods known in the art, but preferably a metal donor, nitrogen donor (eg urea or phthalonitrile itself) of phthalic anhydride, phthalonitrile or derivatives thereof, Preferably, it can be produced by reacting in an organic solvent at any time in the presence of a catalyst.

For example, W. Herbst and K.K. Hunger, “Industrial Organic Pigments” [VCH Publishing, New York, 1993], pages 418-427, H.C. Zollinger, “Colorant Chemistry” (VCH Publishing, 1973) 101-104, and N.C. M.M. Pigerou and M.P. A. Perkins, H.C. A. Edited by Lubs, “Chemistry of Synthetic Dyes and Pigments” [Robert E. See Krieger Publication, 1955], “phthalocyanine pigments” on pages 584-587, further U.S. Pat. Nos. 4,158,572, 4,257,951, and 5,175,282, and British Patent 1502884.

The pigment is preferably used dispersed in the organic resin. Various dispersants can be used according to the organic resin and the pigment to be used.

Examples of the dispersant include phthalic acid, stearic acid, caproic acid, and lipophilic surfactant.

As a method for dispersing the pigment in the organic resin, a known dispersion technique used in ink production or toner production can be used. Examples of the disperser include a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Application Technology" (CMC Publishing, 1986).

The protective layer according to the present invention is preferably formed by applying and drying a resin dissolved in a solvent.

(substrate)
The substrate according to the present invention is a plate that is radiolucent and can carry a scintillator layer, and various kinds of glass, polymer materials, metals, and the like can be used.

For example, plate glass such as quartz, borosilicate glass, chemically strengthened glass, ceramic substrate such as sapphire, silicon nitride, silicon carbide, semiconductor substrate such as silicon, germanium, gallium arsenide, gallium phosphide, gallium nitrogen, and cellulose acetate film , Polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, polycarbonate film, polymer film (plastic film) such as carbon fiber reinforced resin sheet, metal sheet such as aluminum sheet, iron sheet, copper sheet or the metal A metal sheet having an oxide coating layer can be used.

Particularly, a polymer film containing polyimide or polyethylene naphthalate is suitable for forming a columnar scintillator by a vapor phase method using cesium iodide as a raw material.

In particular, the substrate is preferably a flexible polymer film having a thickness of 50 to 500 μm. Here, the “substrate having flexibility” means a substrate having an elastic modulus (E120) at 120 ° C. of 1000 to 6000 N / mm ² , and a polymer film containing polyimide or polyethylene naphthalate as such a substrate. Is preferred.

Note that the “elastic modulus” is the slope of the stress with respect to the strain amount in a region where the strain indicated by the standard line of the sample conforming to JIS-C2318 and the corresponding stress have a linear relationship using a tensile tester. Is what we asked for. This is a value called Young's modulus, and in the present invention, this Young's modulus is defined as an elastic modulus.

Substrate used in the present invention, it is preferable elastic modulus at the 120 ° C. as described above (E120) is ^{1000N / mm 2 ~ 6000N / mm} 2. More preferably, it is 1200 N / mm ² to 5000 N / mm ² .

Specifically, polyethylene naphthalate ^{(E120 = 4100N / mm 2)} , polyethylene terephthalate ^{(E120 = 1500N / mm 2)} , polybutylene naphthalate ^{(E120 = 1600N / mm 2)} , polycarbonate (E120 = 1700N / ^mm 2) , Syndiotactic polystyrene (E120 = 2200 N / mm ² ), polyetherimide (E120 = 1900 N / mm ² ), polyarylate (E120 = 1700 N / mm ² ), polysulfone (E120 = 1800 N / mm ² ), polyethersulfone Examples thereof include a polymer film made of (E120 = 1700 N / mm ² ).

These may be used singly or may be laminated or mixed. Among them, as a particularly preferable polymer film, a polymer film containing polyimide or polyethylene naphthalate is preferable as described above.

(Reflective layer)
The reflective layer according to the present invention is for reflecting the light emitted from the scintillator of the scintillator layer to increase the light extraction efficiency. The reflective layer is preferably formed of a material containing any element selected from the element group consisting of Al, Ag, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au. In particular, it is preferable to use a metal thin film made of the above elements, for example, an Ag film, an Al film, or the like. Two or more such metal thin films may be formed. When the metal thin film has two or more layers, it is preferable that the lower layer is a layer containing Cr from the viewpoint of improving the adhesion to the substrate. Further, a layer made of a metal oxide such as SiO ₂ or TiO ₂ may be provided in this order on the metal thin film to further improve the reflectance.

The reflection layer reflects the light from the scintillator layer as described above, and at the same time is transparent to radiation. The reflective layer according to the present invention is preferably a metal thin film that is radiation transmissive and reflects predetermined light (light emitted from a scintillator) as described above.

The thickness of the reflective layer is preferably 0.01 to 0.3 μm from the viewpoint of the emission light extraction efficiency.

In the present invention, an intermediate layer may be provided between the substrate and the protective layer. The intermediate layer is preferably a layer containing a resin. Specific examples of the resin include polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer, Polyamide resin, polyvinyl acetal, polyester, cellulose derivative (nitrocellulose, etc.), polyimide, polyamide, polyparaxylylene, styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea resin, melamine resin , Phenoxy resin, silicon resin, acrylic resin, urea formamide resin, and the like. Among them, it is preferable to use polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, nitrocellulose, polyimide, and polyparaxylylene.

The thickness of the intermediate layer is preferably 1.0 μm to 30 μm, more preferably 2.0 μm to 25 μm, and particularly preferably 5.0 μm to 20 μm.

(Scintillator layer)
The scintillator layer (also referred to as “phosphor layer”) is a layer composed of a scintillator that emits fluorescence when irradiated with radiation.

That is, the scintillator absorbs energy of incident radiation such as X-rays and emits electromagnetic waves having a wavelength of 300 nm to 800 nm, that is, electromagnetic waves (light) ranging from ultraviolet light to infrared light centering on visible light. Refers to phosphor.

As a material for forming the scintillator layer, various known phosphor materials can be used, but the rate of change from X-ray to visible light is relatively high, and the phosphor can be easily formed into a columnar crystal structure by vapor deposition. For this reason, cesium iodide (CsI) is preferable because scattering of the emitted light in the crystal is suppressed by the light guide effect and the thickness of the scintillator layer (phosphor layer) can be increased.

However, since CsI alone has low luminous efficiency, various activators are added. For example, as shown in Japanese Examined Patent Publication No. 54-35060, a mixture of CsI and sodium iodide (NaI) at an arbitrary molar ratio can be mentioned. Further, for example, CsI as disclosed in Japanese Patent Application Laid-Open No. 2001-59899 is deposited, and indium (In), thallium (Tl), lithium (Li), potassium (K), rubidium (Rb), sodium (Na CsI containing an activating substance such as) is preferred.

Also, as a raw material for forming a CsI scintillator layer containing thallium, an additive containing one or more kinds of thallium compounds and cesium iodide are preferably used. Thallium activated cesium iodide (CsI: Tl) is preferable because it has a broad emission wavelength from 400 nm to 750 nm.

As the thallium compound as an additive containing one or more kinds of thallium compounds, various thallium compounds (compounds having oxidation numbers of + I and + III) can be used.

A preferable thallium compound is thallium bromide (TlBr), thallium chloride (TlCl), thallium fluoride (TlF, TlF ₃ ), or the like.

The melting point of the thallium compound is preferably in the range of 400 to 700 ° C. from the viewpoint of luminous efficiency. In addition, melting | fusing point is melting | fusing point under normal temperature normal pressure.

The molecular weight of the thallium compound is preferably in the range of 206 to 300.

In the scintillator layer, the content of the additive is desirably an optimum amount according to the target performance and the like, but is 0.001 mol% to 50 mol%, more preferably 0.1 to 0.1% with respect to the content of cesium iodide. It is preferable that it is 10.0 mol%.

The thickness of the scintillator layer is preferably 100 to 800 μm, and more preferably 120 to 700 μm from the viewpoint of obtaining a good balance between luminance and sharpness characteristics.

(Moisture resistant protective layer)
The moisture-resistant protective layer according to the present invention focuses on protecting the scintillator layer. That is, phosphors such as cesium iodide (CsI) have high hygroscopicity, and when exposed to moisture, they absorb water vapor in the air and deliquesce, so the main purpose is to prevent this.

In the present invention, the moisture-resistant protective layer covers the scintillator layer, but covering the scintillator layer means covering a portion of the scintillator layer excluding a portion in contact with the protective layer. That is, the scintillator layer is covered with the moisture-resistant protective layer except for the portion in contact with the protective layer.

The thickness of the moisture-resistant protective layer is preferably 12 μm or more and 60 μm or less, more preferably 20 μm or more and 40 μm or less, taking into consideration the protection, sharpness, moisture resistance, workability, etc. of the scintillator (phosphor) layer.

The moisture resistant protective layer preferably contains an organic resin as a main component. Specific examples of the organic resin include polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer. , Polyamide resin, polyvinyl butyral, polyester, cellulose derivatives (cellulose acetate, nitrocellulose, etc.), polyimide, polyamide, polyparaxylylene, styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea Examples thereof include resins, melamine resins, phenoxy resins, silicon resins, acrylic resins, urea formamide resins, and the like. Of these, polyparaxylylene, cellulose derivatives, acrylic resins, polyurethane, and polyimide are preferably used.

The moisture-resistant protective layer is preferably formed by applying a coating solution containing the above resin and drying, and the solvent used for the coating is the same as that used for the protective layer described above. Can do.

The moisture-resistant protective layer according to the present invention is preferably a light absorption layer, and the maximum absorption wavelength is preferably 560 to 650 nm. The protective layer preferably contains at least one of a pigment and a dye so that the maximum absorption wavelength is in the range of 560 to 650 nm.

The moisture-resistant protective layer preferably contains a dispersant and the like in addition to the organic resin.

As the colorant having a maximum absorption wavelength between 560 and 650 nm that can be preferably used in the present invention, known ones described in various documents can be used in addition to commercially available ones. As the colorant, those having absorption in the wavelength range of 560 to 650 nm are preferable, and as the colorant, purple to blue organic or inorganic colorants are preferably used.

As examples of purple to blue organic colorants, the same colorants as those used for the protective layer described above can be used.

The most preferable colorant is a metal phthalocyanine pigment.

Specific examples of the metal phthalocyanine pigment include copper phthalocyanine, and the same colorant as that used in the protective layer can be used.

The moisture-resistant protective layer according to the present invention is preferably formed by coating and drying as described above, but can also be formed by using a vapor deposition method such as a CVD method.

The haze ratio is preferably 3% or more and 40% or less, more preferably 3% or more and 10% or less in consideration of sharpness, radiation image unevenness, manufacturing stability, workability, and the like. A haze rate shows the value measured by Nippon Denshoku Industries Co., Ltd. NDH 5000W. The required haze ratio is appropriately selected from commercially available polymer films and can be easily obtained.

The light transmittance of the moisture-resistant protective layer is preferably 70% or more at 550 nm in consideration of photoelectric conversion efficiency, scintillator emission wavelength, etc., but a film having a light transmittance of 99% or more is difficult to obtain industrially. Therefore, it is preferably substantially 99% to 70%.

The moisture permeability of the moisture-resistant protective layer is preferably 50 g / m ² · day (40 ° C., 90% RH) (measured according to JIS Z0208) or less, more preferably 10 g in consideration of the protection and deliquescence properties of the scintillator layer. / M ² · day (40 ° C./90% RH) (measured in accordance with JIS Z0208) or less is preferable, but a film with a moisture permeability of 0.01 g / m ² · day (40 ° C./90% RH) or less is industrial. Since it is difficult to obtain, it is substantially 0.01 g / m ² · day (40 ° C./90% RH) or more, 50 g / m ² · day (40 ° C./90% RH) (according to JIS Z0208). Measurement) is preferably 0.1 g / m ² · day (40 ° C./90% RH) or more and 10 g / m ² · day (40 ° C./90% RH) (measured according to JIS Z0208) or less. preferable.

<About the above means 2>
The present invention includes a radiation transmissive substrate, an intermediate layer provided on the substrate, a reflective layer provided on the intermediate layer, a protective layer provided on the reflective layer, and the protective layer. In the scintillator panel provided with a scintillator layer provided on and a moisture-resistant protective layer covering the scintillator layer, the intermediate layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more It is characterized by.

In the present invention, a scintillator plate having excellent storage stability can be provided by including at least one pair of two kinds of organic resins having different glass transition temperatures of 5 ° C. or more.

<Intermediate layer>
The intermediate layer according to the present invention is a layer provided between the substrate and the reflective layer, and needs to contain at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

By including two or more organic resins with glass transition temperatures of 5 ° C or higher, a coating film with high Young's modulus and flexibility can be formed. Panels can be handled under severe conditions and stored for a long time under high humidity. Even if it performs, the generation | occurrence | production of a crack etc. does not occur and the stable panel performance can be obtained.

The intermediate layer preferably has a thickness of 1.0 μm to 30 μm, more preferably 2.0 μm to 25 μm, and more preferably 5.0 μm from the viewpoint that sufficient storage characteristics can be obtained and light scattering can be suppressed. It is particularly preferable that the thickness is ˜20 μm.

Specific examples of the organic resin include polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer. Polymer, polyamide resin, polyvinyl acetal, polyester, cellulose derivative (nitrocellulose, etc.), polyimide, polyamide, polyparaxylylene, styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea resin, Examples include melamine resin, phenoxy resin, silicon resin, acrylic resin, urea formamide resin, and the like. Among them, it is preferable to use polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, nitrocellulose, polyimide, and polyparaxylylene.

The two kinds of organic resins contained in at least one set in the intermediate layer are required to have a glass transition temperature different by 5 ° C. or more, but the difference in glass transition temperature is preferably 5 ° C. to 80 ° C., more preferably It is 20 ° C. to 80 ° C., particularly preferably 30 ° C. to 70 ° C.

The content of the resin having a glass transition temperature of 50 to 100 ° C. with respect to the intermediate layer is preferably 30% by mass to 95% by mass, and particularly preferably 50% by mass to 85% by mass.

The content of the resin having a glass transition temperature of −20 ° C. to 45 ° C. with respect to the intermediate layer is preferably 5% by mass to 70% by mass, and particularly preferably 15% by mass to 50% by mass.

The content of the two kinds of organic resins having different glass transition temperatures of 5 ° C. or more with respect to the intermediate layer (total of the two kinds) is preferably 80% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.

Further, the intermediate layer preferably contains one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more. In this case, all except for the additives contained in the following intermediate layer are the one set. It is.

Normally, when forming a scintillator by vapor deposition, the substrate temperature is 150 ° C. to 250 ° C., but by including an organic resin having a glass transition temperature of −20 ° C. to 45 ° C. in the intermediate layer, The protective layer effectively functions as an adhesive layer.

As the solvent used for preparing the intermediate layer, a solvent similar to the solvent used for preparing the protective layer can be used.

The intermediate layer according to the present invention is preferably formed by applying and drying a resin dissolved in a solvent.

As the substrate, the reflective layer, the scintillator, and the moisture-resistant protective layer according to the present invention, those similar to those used in the above means 1 can be used.

<About the above means 3>
The present invention includes a radiation transmissive substrate, a reflective layer provided on the substrate, a protective layer provided on the reflective layer, a scintillator layer provided on the protective layer, and the scintillator layer. A scintillator panel comprising a covering moisture-resistant protective layer, wherein the moisture-resistant protective layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more and has a film thickness of 12 to 60 μm. And

In the present invention, the scintillator having excellent storability, particularly when the moisture-resistant protective layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more and the film thickness of the moisture-resistant protective layer is 12 to 60 μm. Plates can be provided.

The moisture-resistant protective layer according to the present invention needs to contain at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more, and the moisture-resistant protective layer needs to have a thickness of 12 to 60 μm.

By including two or more organic resins with glass transition temperatures of 5 ° C or higher, a coating film with high Young's modulus and flexibility can be formed. The panel can be handled under severe conditions and stored for a long time under high humidity. Even if it performs, the generation | occurrence | production of a crack etc. does not occur and the stable panel performance can be obtained.

Specific examples of the organic resin include polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer. Polymer, polyamide resin, polyvinyl butyral, polyester, cellulose derivatives (cellulose acetate, nitrocellulose, etc.), polyimide, polyamide, polyparaxylylene, styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, Examples include urea resins, melamine resins, phenoxy resins, silicon resins, acrylic resins, urea formamide resins, and the like. Of these, polyparaxylylene, cellulose derivatives, acrylic resins, polyurethane, and polyimide are preferably used.

The two kinds of organic resins contained in at least one set in the moisture-resistant protective layer must have different glass transition temperatures of 5 ° C. or more, but the difference in glass transition temperatures is preferably 5 ° C. to 80 ° C., more preferably 20 ° C. C. to 80.degree. C., particularly preferably 30.degree. C. to 70.degree.

In particular, it contains a resin having a glass transition temperature of 140 to 350 ° C. (more preferably 150 to 300 ° C.) and a resin having a glass transition temperature of 60 to 135 ° C. (more preferably a resin having a temperature of 80 to 120 ° C.). It is preferable.

When these resins are used, the content of the resin having a glass transition temperature of 140 to 350 ° C. with respect to the moisture-resistant protective layer is preferably 30% by mass to 95% by mass, and particularly preferably 50% by mass to 85% by mass.

The content of the resin having a glass transition temperature of 60 ° C. to 135 ° C. with respect to the moisture-resistant protective layer is preferably 5% by mass to 70% by mass, and particularly preferably 15% by mass to 50% by mass.

In addition, the moisture-resistant protective layer preferably contains one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more. In this case, all except for the additives contained in the moisture-resistant protective layer described below are used. One set.

The moisture-resistant protective layer is preferably formed by applying and drying a coating solution for the moisture-resistant protective layer, and the solvent used can be the same solvent as used in the protective layer described above. .

The protective layer preferably contains a dispersant and the like in addition to the organic resin.

The most preferable colorant is a metal phthalocyanine pigment.

The film thickness of the moisture-resistant protective layer according to the present invention is required to be 12 to 60 μm from the viewpoint of storage stability, but is particularly preferably 20 to 60 μm.

In the present invention, an intermediate layer may be provided between the substrate and the protective layer. As the resin used for the intermediate layer, the same resin as described in the above means 1 can be used.

The substrate, the reflective layer, and the scintillator layer according to the present invention can be the same as those used in the above means 1, and the protective layer can be the same as that described in the above means 2.

<About the above means 4>
The present invention relates to a radiation image detector comprising a photoelectric conversion element formed on an output substrate, an organic resin layer provided on the photoelectric conversion element, and a scintillator layer provided on the organic resin layer. (Also referred to as “radiation detector”), the organic resin layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

In the present invention, in particular, when the organic resin layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more, a radiation image detector excellent in storage stability can be provided.

<Organic resin layer>
The organic resin layer according to the present invention is a layer provided between the output substrate and the scintillator layer, and needs to contain at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

By including two or more organic resins with glass transition temperatures of 5 ° C or higher, a coating film with high Young's modulus and flexibility can be formed, handling radiation image detectors under harsh conditions, and long under high humidity Even if the period is preserved, cracks and the like are not generated, and stable performance can be obtained.

4. The thickness of the organic resin layer is preferably 1.0 μm to 50 μm, more preferably 2.0 μm to 40 μm, from the viewpoint that sufficient storage characteristics are obtained and light scattering is suppressed. A thickness of 0 to 30 μm is particularly preferable.

The two organic resins contained in at least one set in the organic resin layer are required to have a glass transition temperature different by 5 ° C. or more, but the difference in glass transition temperature is preferably 5 ° C. to 80 ° C., more preferably Is 20 ° C. to 80 ° C., particularly preferably 30 ° C. to 70 ° C.

The content of the resin having a glass transition temperature of 50 to 100 ° C. with respect to the organic resin layer is preferably 30% by mass to 95% by mass, and particularly preferably 50% by mass to 85% by mass.

The content of the resin having a glass transition temperature of −20 ° C. to 45 ° C. with respect to the organic resin layer is preferably 5% by mass to 70% by mass, and particularly preferably 15% by mass to 50% by mass.

The content (in total of the two types) of two types of organic resins having glass transition temperatures different by 5 ° C. or more is preferably 80% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass. .

In addition, the organic resin layer preferably contains one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more. In this case, all of the organic resin layers except for the additives contained in the organic resin layer are One set.

Usually, when forming a scintillator by vapor deposition, the output substrate temperature is 150 ° C. to 250 ° C., but the organic resin layer should contain an organic resin having a glass transition temperature of −20 ° C. to 45 ° C. Thus, the protective layer effectively functions as an adhesive layer.

As the solvent used for preparing the organic resin layer, a solvent similar to the solvent used for preparing the protective layer can be used.

The organic resin layer according to the present invention is preferably formed by applying and drying a resin dissolved in a solvent.

As the output substrate and scintillator layer according to the present invention, the same substrate and scintillator layer used in the above-mentioned means 1 can be used.

<About the above means 5>
The present invention relates to a radiation image detector comprising a photoelectric conversion element formed on an output substrate, a scintillator layer provided on the photoelectric conversion element, and a reflective layer provided on the scintillator layer. In the present invention, wherein the reflective layer contains at least one set of two kinds of organic resins having different glass transition temperatures of 5 ° C. or more, in particular, the reflective layer has two kinds of organics having glass transition temperatures of 5 ° C. or more different. By containing at least one set of resins, a radiation image detector excellent in storage stability can be provided.

<Reflective layer>
The reflective layer according to the present invention is a layer provided on the scintillator layer, and needs to contain at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.

The thickness of the reflective layer is preferably 50 to 800 μm, more preferably 50 to 500 μm, and more preferably 70 to 300 μm from the viewpoint that sufficient storage characteristics can be obtained and light scattering can be suppressed. Particularly preferred.

The two kinds of organic resins contained in at least one pair in the reflective layer are required to have glass transition temperatures different by 5 ° C. or more, but the difference in glass transition temperature is preferably 5 ° C. to 80 ° C., more preferably It is 20 ° C. to 80 ° C., particularly preferably 30 ° C. to 70 ° C.

The content of the resin having a glass transition temperature of 50 to 100 ° C. with respect to the reflective layer is preferably 30% by mass to 95% by mass, and particularly preferably 50% by mass to 85% by mass.

The content of the resin having a glass transition temperature of −20 ° C. to 45 ° C. with respect to the reflective layer is preferably 5% by mass to 70% by mass, and particularly preferably 15% by mass to 50% by mass.

The content of the two types of organic resins having a glass transition temperature of 5 ° C. or more with respect to the reflective layer (total of the two types) is preferably 80% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.

Further, the reflective layer preferably contains one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more. In this case, all except for the additives contained in the reflective layer described below are included in this set. It is.

As the filler used for the reflective layer, a white pigment is preferable. Examples of white pigments include titanium oxide, zinc oxide, aluminum oxide, calcium carbonate, barium sulfate, and titanium oxide and calcium carbonate are preferred.

As the solvent used for preparing the reflective layer, a solvent similar to the solvent used for preparing the protective layer can be used.

The reflective layer according to the present invention is preferably formed by applying and drying a resin dissolved in a solvent.

As the output substrate and scintillator layer according to the present invention, those similar to those used in the above means 1 can be used.

<About the above means 6>
The present invention relates to a radiation image detector comprising a photoelectric conversion element formed on an output substrate, a scintillator layer provided on the photoelectric conversion element, and a moisture-resistant protective layer provided on the scintillator layer. The moisture-resistant protective layer is characterized in that it contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more and has a film thickness of 12 to 60 μm.

In the present invention, the moisture-resistant protective layer covers the scintillator layer, but covering the scintillator layer means covering a portion of the scintillator layer excluding a portion in contact with the organic resin layer. That is, the scintillator layer is covered with the moisture-resistant protective layer except for the portion in contact with the organic resin layer. However, the cross section of the scintillator layer may or may not be covered with a moisture-resistant protective layer.

The most preferable colorant is a metal phthalocyanine pigment.

In the present invention, an organic resin layer may be provided between the output substrate and the scintillator layer. As the resin used for the organic resin layer, the same resin as described in the above means 4 can be used.

As the output substrate and scintillator layer according to the present invention, the same substrate as that used in the above means 1 and the scintillator layer can be used.

(Method for producing scintillator panel and radiation image detector)
A typical example of a production method for producing the scintillator panel and the radiation image detector of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of the radiation scintillator panel 10. FIG. 2 is an enlarged cross-sectional view of the radiation scintillator panel 10. FIG. 3 is a diagram showing a schematic configuration of the vapor deposition apparatus 61.

<Vapor deposition equipment>
As shown in FIG. 3, the vapor deposition apparatus 61 has a box-shaped vacuum vessel 62, and a vacuum vapor deposition boat 63 is disposed inside the vacuum vessel 62. The boat 63 is a member to be filled as an evaporation source, and an electrode is connected to the boat 63. When a current flows through the electrode to the boat 63, the boat 63 generates heat due to Joule heat. At the time of manufacturing the scintillator panel 10, a mixture containing cesium iodide and an activator compound is filled in the boat 63, and an electric current flows through the boat 63, whereby the mixture can be heated and evaporated. ing.

In addition, as the member to be filled, an alumina crucible around which a heater is wound may be applied, or a refractory metal heater may be applied.

A holder 64 for holding the substrate 1 (not shown) provided with an intermediate layer, a reflective layer, and a protective layer in advance is disposed inside the vacuum vessel 62 and directly above the boat 63. The holder 64 is provided with a heater (not shown), and the substrate 1 mounted on the holder 64 can be heated by operating the heater.

The holder 64 is provided with a rotation mechanism 65 that rotates the holder 64. The rotating mechanism 65 is composed of a rotating shaft 65a connected to the holder 64 and a motor (not shown) as a driving source for the rotating shaft 65. When the motor is driven, the rotating shaft 65a rotates to displace the holder 64 in the boat. It can be rotated in a state of being opposed to 63.

In the vapor deposition apparatus 61, in addition to the above configuration, a vacuum pump 66 is disposed in the vacuum vessel 62. The vacuum pump 66 exhausts the inside of the vacuum container 62 and introduces gas into the vacuum container 62. By operating the vacuum pump 66, the inside of the vacuum container 62 has a gas atmosphere at a constant pressure. Can be maintained below.

<Scintillator panel>
Next, a method for manufacturing the scintillator panel 10 according to claims 1 to 3 of the present invention will be described.

In the production method for producing the scintillator panel 10, the evaporator 61 described above can be suitably used. A method for manufacturing the scintillator panel 10 using the evaporator 61 will be described.

《Formation of intermediate layer》
The intermediate layer 2 can be formed on one surface of the substrate 1 by extrusion coating. A matting agent or filler may be added as necessary to control the surface properties and Young's modulus of the intermediate layer.

<Formation of reflective layer>
A metal thin film (Al film, Ag film, etc.) as the reflective layer 3 is formed on the surface of the substrate 1 provided with the intermediate layer 2 by sputtering. Various types of films in which an Al film is sputter-deposited on a polymer film are available on the market, and these films can also be used.

<Formation of protective layer>
The protective layer 4 is formed by applying and drying a composition obtained by dispersing and dissolving a colorant and an organic resin in the organic solvent.

<Formation of scintillator layer>
As described above, the substrate 1 provided with the intermediate layer 2, the reflective layer 3, and the protective layer 4 is attached to the holder 64, and the boat 63 is filled with a powdery mixture containing cesium iodide and thallium iodide (preparation) Process). In this case, it is preferable that the distance between the boat 63 and the substrate 1 is set to 100 to 1500 mm, and the later-described vapor deposition process is performed within the set value range.

When the preparation process is completed, the vacuum pump 66 is operated to evacuate the inside of the vacuum vessel 62, and the inside of the vacuum vessel 62 is brought to a vacuum atmosphere of 0.1 Pa or less (vacuum atmosphere forming step). Here, “under vacuum atmosphere” means under a pressure atmosphere of 100 Pa or less, and preferably under a pressure atmosphere of 0.1 Pa or less.

Thereafter, an inert gas such as argon is introduced into the vacuum vessel 62, and the inside of the vacuum vessel 62 is maintained in a vacuum atmosphere of 0.1 Pa to 5 Pa. Thereafter, the heater of the holder 64 and the motor of the rotation mechanism 65 are driven, and the substrate 1 attached to the holder 64 is rotated while being heated while facing the boat 63.

In this state, an electric current is passed from the electrode to the boat 63, and the mixture containing cesium iodide and thallium iodide is heated at about 700 to 800 ° C. for a predetermined time to evaporate the mixture.

As a result, innumerable columnar crystals 5a are sequentially grown on the surface of the substrate 1 to form a scintillator layer 5 having a desired thickness (evaporation process). Thereby, the scintillator panel 10 according to the present invention can be manufactured.

The temperature for heating the vapor deposition source is preferably 500 ° C. to 800 ° C., and particularly preferably 630 ° C. to 750 ° C. The substrate temperature is preferably 100 ° C. to 250 ° C., more preferably 150 ° C. to 250 ° C. By setting the substrate temperature within this range, the shape of the columnar crystal is improved and the luminance characteristics are improved.

<Formation of moisture-resistant protective layer>
The moisture resistant protective layer 6 is preferably formed by applying and drying a composition in which an organic resin is dispersed and dissolved in the above organic solvent on the scintillator layer. You may add a coloring agent and a mat agent to the said composition as needed. Alternatively, the scintillator layer may be sealed with a sealing film formed by applying and drying a composition in which an organic resin is dispersed and dissolved on a support (PET, PEN, aramid, etc.).

(Radiation image detector)
Hereinafter, as an application example of the scintillator panel 10, a configuration of the radiation image detection apparatus 100 including the scintillator plate 10 will be described with reference to FIGS. 4 and 5. FIG. 4 is a partially broken perspective view showing a schematic configuration of the radiation image detection apparatus 100. FIG. 5 is an enlarged cross-sectional view of the imaging panel 51.

As shown in FIG. 4, the radiation image detection apparatus 100 includes an imaging panel 51, a control unit 52 that controls the operation of the radiation image detection apparatus 100, a rewritable dedicated memory (for example, a flash memory), and the like. A memory unit 53 that is a storage unit that stores the output image signal, a power supply unit 54 that is a power supply unit that supplies power necessary to obtain the image signal by driving the imaging panel 51, and the like 55 is provided inside. The housing 55 includes a communication connector 56 for performing communication from the radiation image detection apparatus 100 to the outside as necessary, an operation unit 57 for switching the operation of the radiation image detection apparatus 100, and completion of preparation for radiographic image capturing. In addition, a display unit 58 indicating that a predetermined amount of image signal has been written in the memory unit 53 is provided.

Here, if the radiographic image detection apparatus 100 is provided with a power supply unit 54 and a memory unit 53 for storing an image signal of the radiographic image, and the radiographic image detection apparatus 100 is detachable via a connector 56, the radiographic image detection apparatus. It can be set as the portable structure which can carry 100.

As shown in FIG. 5, the imaging panel 51 includes a scintillator panel 10 and an output substrate 20 that absorbs electromagnetic waves from the scintillator panel 10 and outputs an image signal.

The scintillator panel 10 is disposed on the radiation irradiation surface side and is configured to emit an electromagnetic wave corresponding to the intensity of incident radiation.

The output substrate 20 is provided on the surface opposite to the radiation irradiation surface of the scintillator panel 10, and includes a diaphragm 20a, a photoelectric conversion element 20b, an image signal output layer 20c, and a substrate 20d in this order from the scintillator panel 10 side. Yes.

The diaphragm 20a is for separating the scintillator panel 10 from other layers.

The photoelectric conversion element 20 b includes a transparent electrode 21, a charge generation layer 22 that is excited by electromagnetic waves that have passed through the transparent electrode 21 to enter the light, and generates a charge, and a counter electrode 23 that is a counter electrode for the transparent electrode 21. The transparent electrode 21, the charge generation layer 22, and the counter electrode 23 are arranged in this order from the diaphragm 20a side.

The transparent electrode 21 is an electrode that transmits an electromagnetic wave that is photoelectrically converted, and is formed using a conductive transparent material such as indium tin oxide (ITO), SnO ₂ , or ZnO.

The charge generation layer 22 is formed in a thin film on one surface side of the transparent electrode 21, and contains an organic compound that separates charges by light as a compound capable of photoelectric conversion. Each of them contains a conductive compound as an electron acceptor. In the charge generation layer 22, when an electromagnetic wave is incident, the electron donor is excited to emit electrons, and the emitted electrons move to the electron acceptor, and charge, that is, holes in the charge generation layer 22. And electron carriers are generated.

Here, examples of the conductive compound as the electron donor include a p-type conductive polymer compound. Examples of the p-type conductive polymer compound include polyphenylene vinylene, polythiophene, poly (thiophene vinylene), polyacetylene, polypyrrole, Those having a basic skeleton of polyfluorene, poly (p-phenylene) or polyaniline are preferred.

Examples of the conductive compound as the electron acceptor include an n-type conductive polymer compound. As the n-type conductive polymer compound, those having a basic skeleton of polypyridine are preferable, and in particular, poly (p-pyridyl) Those having a basic skeleton of vinylene) are preferred.

The film thickness of the charge generation layer 22 is preferably 10 nm or more (especially 100 nm or more) from the viewpoint of securing the amount of light absorption, and is preferably 1 μm or less (particularly 300 nm or less) from the viewpoint that the electric resistance does not become too large. .

The counter electrode 23 is disposed on the opposite side of the surface of the charge generation layer 22 where the electromagnetic wave is incident. The counter electrode 23 can be selected and used from, for example, a general metal electrode such as gold, silver, aluminum, and chromium, or the transparent electrode 21. Small (4.5 eV or less) metals, alloys, electrically conductive compounds and mixtures thereof are preferably used as electrode materials.

In addition, a buffer layer may be provided between each electrode (transparent electrode 21 and counter electrode 23) sandwiching the charge generation layer 22 so as to act as a buffer zone so that the charge generation layer 22 and these electrodes do not react. Good. Examples of the buffer layer include lithium fluoride and poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate), 2,9-dimethyl-4,7-diphenyl [1,10] phenanthroline, and the like. Formed using.

The image signal output layer 20c performs accumulation of charges obtained by the photoelectric conversion element 20b and output of a signal based on the accumulated charges. Charge for accumulating the charges generated by the photoelectric conversion element 20b for each pixel. The capacitor 24 is a storage element, and the transistor 25 is an image signal output element that outputs the stored charge as a signal.

As the transistor 25, for example, a TFT (Thin Film Transistor) is used. This TFT may be an inorganic semiconductor type used in a liquid crystal display or the like, or an organic semiconductor, and is preferably a TFT formed on a plastic film. As the TFT formed on the plastic film, an amorphous silicon type is known, but in addition, it was made of FSA (Fluidic Self Assembly) technology developed by Alien Technology in the United States, that is, made of single crystal silicon. A TFT may be formed on a flexible plastic film by arranging micro CMOS (Nanoblocks) on an embossed plastic film. Furthermore, Science, 283, 822 (1999) and Appl. Phys. A TFT using an organic semiconductor as described in documents such as Lett, 771488 (1998), Nature, 403, 521 (2000) may be used.

Thus, the transistor 25 is preferably a TFT manufactured by the FSA technique and a TFT using an organic semiconductor, and a TFT using an organic semiconductor is particularly preferable. If a TFT is formed using this organic semiconductor, equipment such as a vacuum deposition apparatus is not required as in the case where a TFT is formed using silicon, and the TFT can be formed by utilizing printing technology or inkjet technology. Cost is low. Furthermore, since the processing temperature can be lowered, it can also be formed on a plastic substrate that is vulnerable to heat.

The transistor 25 accumulates electric charges generated in the photoelectric conversion element 20b and is electrically connected to a collecting electrode (not shown) which is one electrode of the capacitor 24. The capacitor 24 accumulates charges generated by the photoelectric conversion element 20 b and reads the accumulated charges by driving the transistor 25. That is, by driving the transistor 25, a signal for each pixel of the radiation image can be output.

The substrate 20d functions as a support for the imaging panel 51, and can be made of the same material as the substrate 1.

Next, the operation of the radiation image detection apparatus 100 will be described.

First, the radiation incident on the radiation image detection apparatus 100 is incident from the radiation scintillator panel 10 side of the imaging panel 51 toward the substrate 20d side.

Then, the radiation incident on the scintillator panel 10 is absorbed by the scintillator layer 5 in the radiation scintillator panel 10 and emits an electromagnetic wave corresponding to its intensity. Of the emitted electromagnetic wave, the electromagnetic wave incident on the output substrate 20 passes through the diaphragm 20 a and the transparent electrode 21 of the output substrate 20 and reaches the charge generation layer 22. Then, the electromagnetic wave is absorbed in the charge generation layer 22 and a hole-electron pair (charge separation state) is formed according to the intensity.

Thereafter, the generated charges are transported to different electrodes (transparent electrode film and conductive layer) by an internal electric field generated by application of a bias voltage by the power supply unit 54, and a photocurrent flows.

Thereafter, the holes carried to the counter electrode 23 side are accumulated in the capacitor 24 of the image signal output layer 20c. The accumulated holes output an image signal when the transistor 25 connected to the capacitor 24 is driven, and the output image signal is stored in the memory unit 53.

Next, a radiation image detector according to claims 4 to 6 of the present invention will be described with reference to FIG.

FIG. 6 is an enlarged cross-sectional view of the imaging panel portion of the radiation image detector.

The image signal output layer 202 is provided on the output substrate 201, and the photoelectric conversion element 203 including the counter electrode 203c, the charge generation layer 203b, and the transparent electrode 203a is provided on the image signal output layer.

The imaging panel has a scintillator layer on the photoelectric conversion element, but the configuration of the radiation image detector 200 including the scintillator layer 205 directly or via the organic resin layer 204 on the transparent electrode 203a will be described.

The scintillator layer 205 can be formed in the same manner as described in << Scintillator layer formation >> in the above-described method of manufacturing the scintillator panel 10, and directly on the transparent electrode 203b of the output substrate 201 or the organic resin layer 204. A scintillator layer can be provided via

Although the case where the reflective layer 206 and the moisture resistant protective layer 207 are provided on the scintillator layer 205 is illustrated, for example, an adhesive layer (not shown) is further provided between the reflective layer 206 and the moisture resistant protective layer 207 on the scintillator layer 205. The moisture-resistant protective layer 207 may be divided into two layers (moisture-resistant protective layer-1 and moisture-resistant protective layer-2), and the moisture-resistant protective layer-1, the reflective layer, and the moisture-resistant protective layer-2 are formed on the scintillator layer. Each layer may be provided in order.

The order of the layers can be changed as appropriate, and a moisture-resistant protective layer and a reflective layer may be provided on the scintillator layer so that the reflective layer is the outermost layer.

In addition, the reflective layer and the moisture-resistant protective layer may be separated from each other, and a layer serving as the reflective layer and the moisture-resistant protective layer may be provided.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

Example 1
(Production of reflective layer)
A reflection layer (0.02 μm) was formed by sputtering aluminum on a 125 μm-thick polyimide film (UPILEX-125S manufactured by Ube Industries).

(Preparation of protective layer)
Addition amount of organic resin described in Table 1 is listed in Table 1. Hexamethylene diisocyanate 3 parts by weight Phthalocyanine blue 0.1 part by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight For 15 hours to obtain a coating solution for coating a protective layer.

This coating solution was applied to the aluminum reflective layer surface of the substrate by an extrusion coater so that the dry film thickness was 2.5 μm.

(Formation of scintillator layer)
A scintillator phosphor (CsI: 0.003 mol Tl) was deposited on the light absorption layer side of the substrate by using the vapor deposition apparatus shown in FIG. 3 to form a scintillator (phosphor) layer.

That is, first, the above-mentioned phosphor raw material was filled in a resistance heating crucible as an evaporation material, and a support was placed on a rotating support holder, and the distance between the support and the evaporation source was adjusted to 400 mm.

Subsequently, the inside of the vapor deposition apparatus was once evacuated, Ar gas was introduced and the degree of vacuum was adjusted to 0.5 Pa, and then the substrate temperature was maintained at 150 ° C. while rotating the support at a speed of 10 rpm. Next, the resistance heating crucible was heated to deposit a phosphor, and when the scintillator layer had a thickness of 500 μm, the deposition was terminated to obtain a scintillator panel (radiation image conversion panel).

(Formation of moisture-resistant protective layer)
Cellulose acetate butyrate (glass transition temperature: 161 ° C.) 100 parts by weight Phthalocyanine blue 0.1 part by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight The above formulation is mixed and dispersed in a bead mill for 15 hours. An installation coating solution was obtained.

The coating solution was applied onto the scintillator layer by an extrusion coater so that the dry film thickness was 20 μm, and scintillator panel samples 101 to 112 were obtained.

Example 2
(Preparation of intermediate layer)
Organic resin of the kind described in Table 2 is added in Table 2. Phthalocyanine blue 0.1 part by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight The above formulation is mixed and dispersed in a bead mill for 15 hours. A coating solution for coating was obtained.

This coating solution was applied on a substrate (made of amorphous carbon, thickness 1 mm) using an extrusion coater so that the dry film thickness was 10 μm.

(Production of reflective layer)
A reflective layer (0.02 μm) was formed by sputtering aluminum on the substrate provided with the intermediate layer.

(Preparation of protective layer)
Byron 200 (manufactured by Toyobo Co., Ltd .: polyester resin Tg: 67 ° C.) 100 parts by weight Phthalocyanine blue 0.1 part by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight The above formulation is mixed and dispersed in a bead mill for 15 hours for protection A coating solution for layer coating was obtained.

This coating solution was applied onto the aluminum reflective layer by an extrusion coater so that the dry film thickness was 2.5 μm.

The coating solution was applied onto the scintillator layer with an extrusion coater so that the dry film thickness was 20 μm, and scintillator panel samples 201 to 212 were obtained.

Example 3
(Production of reflective layer)
A reflection layer (0.02 μm) was formed by sputtering aluminum on a 125 μm-thick polyimide film (UPILEX-125S manufactured by Ube Industries).

The coating solution was applied on the aluminum reflective layer of the substrate by an extrusion coater so that the dry film thickness was 2.5 μm.

(Formation of moisture-resistant protective layer)
Organic resins of the types listed in Table 3 Addition amounts listed in Table 3 Phthalocyanine blue 0.1 parts by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight The above formulation is mixed and dispersed in a bead mill for 15 hours, and a protective layer A coating solution for coating was obtained.

The coating solution was applied onto the scintillator layer by an extrusion coater so that the dry film thickness was a value shown in Table 3, and samples of scintillator panels 301 to 319 were obtained.

However, as the moisture-resistant protective layer of the sample 319, a moisture-resistant protective film made of polyparaxylylene formed by the CVD method described in “0022” of JP-A-2007-279051 was used.

The type of resin used is described below.
B-1 Polyvinyl butyral Tg: 65 ° C
B-2 Polyester (Byron 300) Tg: 6 ° C
B-3 Polyester (Byron 200) Tg: 67 ° C
B-4 Cellulose acetate butyrate Tg: 161 ° C
B-5 Polymethylmethacrylate Tg: 105 ° C
B-6 Phenoxy resin (PKHH) Tg: 105 ° C
B-7 Polyester polyurethane (containing caprolactone group) Tg: 20 ° C
B-8 Polyester polyurethane (containing cyclohexyl group) Tg: 70 ° C
B-9 Polyester polyurethane (containing aliphatic polyester) Tg: -20 ° C
B-10 Polyester polyurethane (including aromatic polyester) Tg: 50 ° C
B-11 Cellulose acetate propionate Tg: 150 ° C
In addition, about the measurement of the glass transition temperature (Tg) of resin, DSC method (it measured by calculating | requiring an endothermic curve using a differential scanning calorimeter) was used.

<Evaluation>
(Evaluation of moisture resistance)
Each of the scintillator panel samples obtained above was sealed, and then left for 30 days in an environment of 30 ° C. and 70%, and the sharpness and luminance before and after being left were compared. The evaluation was carried out by the methods described later, and an average value at 20 points within the surface of the scintillator was obtained and used as the value of each sample.

The scintillator panel was set in PaxScan2520 (Varian FPD), and the sharpness and brightness were evaluated by the methods shown below.

"Evaluation of sharpness"
X-rays with a tube voltage of 80 kVp were irradiated to the radiation incident surface side of the FPD through a lead MTF chart, and image data was detected and recorded on a hard disk. Thereafter, the recording on the hard disk was analyzed by a computer, and the modulation transfer function MTF (MTF value at a spatial frequency of 1 cycle / mm) of the X-ray image recorded on the hard disk was used as an index of sharpness. MTF is an abbreviation for Modulation Transfer Function.

"Evaluation of brightness"
X-rays having a voltage of 80 kVp were irradiated from the back surface of the sample (surface on which the scintillator layer was not formed), the image data was detected by an FPD provided with a scintillator, and the average signal value of the image was defined as the emission luminance.

Tables 1 to 3 show the ratio of the value after being left to the value before being left for brightness and sharpness. The value is closer to 1.0 as the property is less degraded under the environment of 30 ° C. and 70% RH.

From Tables 1 to 3, it can be seen that the scintillator plate of the present invention is excellent in preservability with little deterioration in brightness and sharpness.

Example 4
A plurality of photodiodes and a plurality of TFT elements were formed on a glass substrate, and the whole was covered with an organic resin layer having the following composition.

(Preparation of organic resin layer)
Addition amount of organic resin described in Table 4 is listed in Table 4. Hexamethylene diisocyanate 3 parts by weight Phthalocyanine blue 0.1 part by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight For 15 hours to obtain a coating solution for coating a protective layer.

The coating solution was applied by an extrusion coater so that the dry film thickness was 20 μm on the side of the substrate on which the photoelectric conversion element was provided.

(Formation of scintillator layer)
A scintillator phosphor (CsI: 0.003 mol Tl) was deposited on the side of the substrate on which the organic resin layer was provided by using the deposition apparatus shown in FIG. 3 to form a scintillator (phosphor) layer.

Subsequently, the inside of the vapor deposition apparatus was once evacuated, Ar gas was introduced and the degree of vacuum was adjusted to 0.5 Pa, and then the substrate temperature was maintained at 150 ° C. while rotating the support at a speed of 10 rpm. Next, the resistance heating crucible was heated to deposit the phosphor, and the deposition was terminated when the scintillator layer had a thickness of 500 μm.

(Production of reflective layer)
Titanium oxide (average particle size 0.20 μm) 15 parts by mass Polyvinyl butyral 2 parts by mass Hexamethylene diisocyanate 0.2 parts by mass Cyclohexanone 100 parts by mass Methyl ethyl ketone (MEK) 60 parts by mass Toluene 40 parts by mass For 15 hours to obtain a coating solution for coating a protective layer.

The coating solution was applied by an extrusion coater so that the dry film thickness was 100 μm on the side of the substrate on which the photoelectric conversion element was provided.

The coating solution was applied on the reflective layer by an extrusion coater so that the dry film thickness was 20 μm. Thereafter, it was covered with a casing made of a glass substrate and sealed under reduced pressure to obtain radiation image detectors 401 to 412.

Example 5
A plurality of photodiodes and a plurality of TFT elements were formed on a glass substrate, and the whole was covered with an organic resin layer having the following composition.

(Preparation of organic resin layer)
Byron 200 (manufactured by Toyobo Co., Ltd .: polyester resin Tg: 67 ° C.) 100 parts by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight The above formulation is mixed and dispersed in a bead mill for 15 hours, and applied for coating an organic resin layer. A liquid was obtained.

(Production of reflective layer)
Titanium oxide (average particle size 0.20 μm) 15 parts by mass Organic resin of the type shown in Table 5 Addition amount is shown in Table 5 Hexamethylene diisocyanate 0.2 parts by mass Cyclohexanone 100 parts by mass Methyl ethyl ketone (MEK) 60 parts by mass 40 parts by mass of toluene The above formulation was mixed and dispersed in a bead mill for 15 hours to obtain a coating solution for coating a protective layer.

The coating solution was applied on the reflective layer by an extrusion coater so that the dry film thickness was 20 μm. Thereafter, it was covered with a casing made of a glass substrate, and sealed under reduced pressure to obtain radiation image detectors 501 to 512.

However, as the reflective layer of the sample 512, a reflective layer described in “0070” of JP-A-2008-215951 was used.

Example 6
A plurality of photodiodes and a plurality of TFT elements were formed on a glass substrate, and the whole was covered with an organic resin layer having the following composition.

(Formation of moisture-resistant protective layer)
Organic resin of the type described in Table 6 Addition amount described in Table 6 Phthalocyanine blue 0.1 part by weight Methyl ethyl ketone (MEK) 100 parts by weight Toluene 100 parts by weight The above formulation is mixed and dispersed in a bead mill for 15 hours, and a protective layer A coating solution for coating was obtained.

The coating solution was applied onto the scintillator layer by an extrusion coater so that the dry film thickness was as shown in Table 6. Thereafter, it was covered with a casing made of a glass substrate and sealed under reduced pressure to obtain radiation image detectors 601 to 619.

However, as the moisture-resistant protective layer, a moisture-proof layer (trade name: GX film (PET) manufactured by Toppan Printing Co., Ltd.) described in “0071” of JP-A-2008-215951 was used.

The obtained radiographic image detector was evaluated.

<Evaluation>
(Evaluation of moisture resistance)
Each of the radiation image detectors obtained above was left in an environment of 30 ° C. and 70% for 30 days, and the sharpness and brightness before and after being left were compared. The evaluation was carried out by the methods described later, and an average value at 20 points within the surface of the scintillator was obtained and used as the value of each sample.

The results are shown in Tables 4-6.

From Tables 4 to 6, it can be seen that the radiographic image detector of the present invention is excellent in storage stability with little deterioration in brightness and sharpness.

Claims

A radiation transmissive substrate, a reflective layer provided on the substrate, a protective layer provided on the reflective layer, a scintillator layer provided on the protective layer, and a moisture-resistant protective layer covering the scintillator layer A scintillator panel comprising: a protective layer containing at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.
A radiation transmissive substrate, an intermediate layer provided on the substrate, a reflective layer provided on the intermediate layer, a protective layer provided on the reflective layer, and provided on the protective layer A scintillator panel comprising a scintillator layer and a moisture-resistant protective layer covering the scintillator layer, wherein the intermediate layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more. Scintillator panel.
A radiation transmissive substrate, a reflective layer provided on the substrate, a protective layer provided on the reflective layer, a scintillator layer provided on the protective layer, and a moisture-resistant protective layer covering the scintillator layer And the moisture-resistant protective layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more and has a film thickness of 12 to 60 μm. .
A radiation image detector comprising: a photoelectric conversion element formed on a substrate; an organic resin layer provided on the photoelectric conversion element; and a scintillator layer provided on the organic resin layer. The radiation image detector, wherein the layer contains at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.
In a radiation image detector comprising a photoelectric conversion element formed on a substrate, a scintillator layer provided on the photoelectric conversion element, and a reflection layer provided on the scintillator layer, the reflection layer comprises: A radiation image detector comprising at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more.
In a radiological image detector comprising a photoelectric conversion element formed on a substrate, a scintillator layer provided on the photoelectric conversion element, and a moisture-resistant protective layer provided on the scintillator layer, the moisture-resistant protective layer However, a radiation image detector comprising at least one set of two kinds of organic resins having glass transition temperatures of 5 ° C. or more and a film thickness of 12 to 60 μm.