JP2018009804A - Radiation image conversion panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation image conversion panel with improved interlayer adhesiveness between a moisture-proof layer arranged on a phosphor layer and a protective layer formed thereon.SOLUTION: A radiation image conversion panel comprises: a base on which a plurality of photoelectric conversion elements are two-dimensionally arrayed; a phosphor layer which is arranged on the side of photoelectric conversion element of the base; a resin layer which is arranged on the side opposite to photoelectric conversion element of the phosphor layer and in which light scattering particles are dispersed in binder resin; a moisture-proof layer which is arranged on the side opposite to photoelectric conversion elements of the resin layer; and a protective layer which is arranged on the side opposite to photoelectric conversion elements of the moisture-proof layer, in which a thermosetting resin layer is arranged in the middle between the moisture-proof layer and the protective layer, and a generation amount of volatile organic compounds (VOC) of the thermosetting resin layer is 0.5 g/mor less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiation image conversion panel having high sharpness, excellent adhesion between layers, and delamination deterrence.

  In recent years, digital radiographic image detectors such as computed radiography (CR) and flat panel detectors (FPD) have been capable of directly obtaining digital radiographic images, and cathode tubes. Since it is possible to directly display an image on an image display device such as a liquid crystal panel, it is widely used for image diagnosis in hospitals and clinics. Recently, a flat panel using a scintillator layer containing cesium iodide (CsI) and combined with a thin film transistor (TFT) has attracted attention as a highly sensitive X-ray image visualization system.

As the scintillator layer, for example, a material mainly composed of CsI having a columnar crystal structure formed by vapor deposition is known.
In order to improve the adhesion of the columnar crystals, Patent Document 1 (Japanese Patent Laid-Open No. 2013-15346) discloses that a columnar crystal group is filled with a filler and flattened, and Patent Document 2 ( In JP 2013-15347 A), an internal space is formed between the support substrate and the sensor substrate, and a vent portion that opens and closes according to the pressure difference between the internal space that houses the scintillator and the external space, It is disclosed that peeling at the interface between the scintillator and the adhesive layer is suppressed. Furthermore, Patent Document 3 (Japanese Patent Application Laid-Open No. 2013-50364) discloses that the space containing the scintillator and the image array is decompressed and brought into close contact without adhesion. Patent Document 3 further discloses Patent Document 4 (Japanese Patent Laid-Open No. 2012-230063), in which a protective material is inserted between the tip portions of the columnar crystals and the gaps between the tip portions are filled, thereby It is disclosed that a deformation is suppressed and a gap is provided between the protective material and the side surface of the tip of the columnar crystal to suppress a decrease in image sharpness. Patent Documents 3 and 4 also disclose that a filler at the tip of the CsI columnar crystal is filled. Examples of the filler include phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, diallyl phthalate. Resin is illustrated.

Furthermore, the radiation detection which has a board | substrate, the fluorescent substance layer which converts the radiation formed on this board | substrate into light, and the several fluorescent substance protective layer laminated | stacked on this fluorescent substance layer In the device
Patent Document 5 (Patent No. 4612815) discloses a radiation detection device in which each of the plurality of phosphor protective layers is made of a hot-melt resin, and one of the plurality of phosphor protective layers covers the phosphor layer and is in close contact with the substrate. Gazette).

JP 2013-015346 A JP2013-015347A JP2013-0050364A JP 2012-230063 A Japanese Patent No. 4612815

  Although providing a filling layer to protect the tip of the columnar crystal has been disclosed, it has not been considered to improve the adhesion between layers disposed on the phosphor layer and to suppress delamination.

Under such circumstances, it has been found that the interlayer between the moisture-proof layer made of metal and the protective layer made of PET resin or the like formed thereon is easy to peel off.
Then, if a layer made of a thermosetting resin is disposed between the metal layer and the protective layer, and the amount of volatile organic substances (VOC) generated from the thermosetting resin is reduced to a predetermined amount or less, the above It has been found that any of the problems can be solved, and the present invention has been completed.

The configuration of the present invention is as follows.
[1] Radiation image conversion panel,
A base in which a plurality of photoelectric conversion elements are two-dimensionally arranged;
A phosphor layer disposed on the photoelectric conversion element side of the base;
A resin layer disposed on the opposite side of the phosphor layer from the photoelectric conversion element, in which light scattering particles are dispersed in a binder resin;
A moisture-proof layer disposed on the opposite side of the resin layer from the photoelectric conversion element;
It consists of a protective layer disposed on the opposite side of the moisture-proof layer to the photoelectric conversion element,
A thermosetting resin layer is disposed between the moisture-proof layer and the protective layer, and the amount of volatile organic substances (VOC) generated in the thermosetting resin layer is 0.5 g / m ² or less. A radiation image conversion panel.
[2] In the radiation conversion panel according to [1], the light scattering particles include white pigment, titanium oxide, zinc oxide, lead oxide, magnesium oxide, aluminum oxide, barium oxide, iron oxide, carbon black, many Including at least one selected from ring pigments, azo pigments, lake pigments,
The radiation image conversion panel according to [1], wherein the binder resin includes at least one selected from an acrylic resin, a urethane resin, and a phenol resin.
[3] The radiation image conversion panel according to [1] or [2], wherein the moisture-proof layer is composed of a metal thin film.
[4] The protective layer is at least one selected from polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polyimide resin, polyester resin, polybutylene terephthalate (PBT) resin, polyetherimide resin, and polycarbonate resin. The radiation image conversion panel according to any one of [1] to [3], comprising the above resin.
[5] The thermosetting resin layer is at least one selected from diallyl phthalate resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, and epoxy resin [1] to [ 4. The radiation image conversion panel according to any one of [4].
[6] The radiation image conversion panel according to any one of [1] to [5], wherein the thermosetting resin layer has a linear expansion coefficient of 20 ppm or less.
[7] A scintillator assy creation step of forming a phosphor layer on a base in which a plurality of photoelectric conversion elements are two-dimensionally arranged;
On the phosphor layer of the scintillator assy, a resin layer forming step of applying a mixture in which light scattering particles are dispersed in a binder resin;
A moisture-proof layer assy forming step of forming a thermosetting resin layer and a moisture-proof layer in this order on at least one surface of the protective layer;
A bonding step of bonding the resin layer side of the scintillator assy and the moisture-proof layer side of the moisture-proof layer assy to face each other,
The manufacturing method of the radiographic image conversion panel characterized by including these.

  According to the present invention, by disposing a specific thermosetting resin layer in the intermediate layer, adhesion between layers due to temperature fluctuation of the radiation image conversion panel is increased, and separation between layers can be suppressed.

It is a schematic cross section which shows the scintillator panel which concerns on this invention.

The radiation image conversion panel of the present invention is
A base in which a plurality of photoelectric conversion elements are two-dimensionally arranged;
A phosphor layer disposed on the photoelectric conversion element side of the base;
A resin layer disposed on the opposite side of the phosphor layer from the photoelectric conversion element, in which light scattering particles are dispersed in a binder resin;
A moisture-proof layer disposed on the opposite side of the resin layer from the photoelectric conversion element;
It consists of a protective layer disposed on the opposite side of the moisture-proof layer to the photoelectric conversion element,
A thermosetting resin layer is disposed between the moisture-proof layer and the protective layer, and the amount of volatile organic substances (VOC) generated in the thermosetting resin layer is 0.5 g / m ² or less. To do.
The

A basic configuration of such a radiation image conversion panel according to the present invention is shown in FIG.
As shown in FIG. 1, the radiation image conversion panel 10 according to the present invention includes a base 1, a phosphor layer 2, a resin layer 3, a moisture-proof layer 4, a thermosetting resin layer 5, and a protective layer 6. Are provided in a predetermined arrangement.
Hereinafter, each component will be described in order.

The base base 1 is composed of a substrate and a photoelectric conversion element 7, and a light receiving portion is composed of wiring and a thin film transistor (TFT) as necessary. Either the sensor protective layer or the phosphor base layer may be provided on the photoelectric conversion element 7 side.

  The substrate is not particularly limited, and even if it is glass or magnesium, it can be broadly classified into a rigid substrate such as a plastic resin plate and a flexible substrate such as a film substrate, but is not particularly limited. Examples of the film substrate include polyester resin films such as polyethylene terephthalate (PET), polyethylene naphthalate, and modified polyester, polyethylene (PE) resin films, polypropylene (PP) resin films, polystyrene resin films, and cyclic olefin resins. Polyolefin resin films, vinyl resin films such as polyvinyl chloride and polyvinylidene chloride, polyvinyl acetal resin films such as polyvinyl butyral (PVB), polyether ether ketone (PEEK) resin films, polysulfone (PSF) resin films, poly Ether sulfone (PES) resin film, polycarbonate (PC) resin film, polyamide resin film, polyimide resin film, acrylic resin film, tria It can be exemplified chill cellulose (TAC) resin film. In addition to these resin films, an inorganic glass film may be used as the substrate.

  The photoelectric conversion element 7 converts light converted from radiation by the phosphor layer 2 into electric charge, and may have any specific structure as long as it has such a function. For example, as the photoelectric conversion element 7, an MIS type sensor, a PIN type sensor, a TFT type sensor, or the like can be used as appropriate. The photoelectric conversion element may be a two-dimensional photosensor such as a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) sensor. The photoelectric conversion elements are two-dimensionally arranged and provided on the base.

The base 1 may be provided with an element protective layer and a base layer. The element protective layer is for covering and protecting the light receiving portion of the photoelectric conversion element, and is preferably an inorganic film such as SiN or SiO ₂ . The underlayer is provided on the element protective layer as necessary, and the material is preferably a heat-resistant resin made of an organic substance such as polyimide or polyparaxylylene.

Phosphor layer 2
The phosphor layer 2 is made of a phosphor and has a role of converting X-ray energy, which is radiation incident from the outside, into visible light.

  In the present invention, the term “phosphor” refers to a phosphor that emits light when atoms are excited when it is irradiated with ionizing radiation such as α-rays, γ-rays, and X-rays. That is, it refers to a phosphor that converts radiation into ultraviolet / visible light and emits it. The phosphor is not particularly limited as long as it is a material that can efficiently convert radiation energy such as X-rays incident from the outside into light. Further, the conversion of radiation into light is not necessarily performed instantaneously, and a method in which a latent image is temporarily stored in the phosphor layer and read out later may be used.

  As the phosphor according to the present invention, a substance capable of converting radiation such as X-rays into different wavelengths such as visible light can be appropriately used. Specifically, scintillators and phosphors described on pages 284 to 299 of “Phosphor Handbook” (Edited by Fluorescent Materials Association, Ohmsha, 1987), and the website of Lawrence Berkeley National Laboratory, USA Although the substances described in “Scintillation Properties (http://scintillator.lbl.gov/)” can be considered, even if the substance is not pointed out here, “radiation such as X-rays is converted into different wavelengths such as visible light” Any substance that can be used can be used.

Specific examples of the phosphor composition include the following examples. First,
Basic composition formula (I): M _I X · aM _II X ′ ₂ · bM _III X ″ ₃ : zA
And metal halide phosphors represented by the formula:

In the basic composition formula (I), M _I is an element that can be a monovalent cation, that is, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), thallium. It represents at least one selected from the group consisting of (Tl) and silver (Ag).

M _II is an element that can be a divalent cation, that is, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), nickel (Ni), copper (Cu), It represents at least one selected from the group consisting of zinc (Zn) and cadmium (Cd).

M _III represents at least one selected from the group consisting of scandium (Sc), yttrium (Y), aluminum (Al), gallium (Ga), indium (In), and elements belonging to lanthanoids.

X, X ′, and X ″ each represent a halogen element, but each may be a different element or the same element.
A is composed of Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl and Bi (bismuth). Represents at least one element selected from the group;
a, b and z each independently represent a numerical value within the range of 0 ≦ a <0.5, 0 ≦ b <0.5, and 0 <z <1.0.

Also,
Also included are rare earth activated metal fluorohalide phosphors represented by the basic composition formula (II): M _II FX: zLn.

In the basic composition formula (II), M _II represents at least one alkaline earth metal element, Ln represents at least one element belonging to the lanthanoid, and X represents at least one halogen element. Z is 0 <z ≦ 0.2.

Also,
Basic composition formula (III): Ln ₂ O ₂ S: zA
And rare earth oxysulfide phosphors.

  In the basic composition formula (III), Ln is at least one element belonging to the lanthanoid, A is Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, At least one element selected from the group consisting of Lu, Na, Mg, Cu, Ag (silver), Tl and Bi (bismuth) is represented. Z is 0 <z <1.

In particular, Gd ₂ O ₂ S using gadolinium (Gd) as Ln emits high light in a wavelength region where the sensor panel is most likely to receive light by using terbium (Tb), dysprosium (Dy), etc. as the element species of A. This is preferred because it is known to exhibit properties.

Also,
Basic formula _{(IV): M II S:} zA
The metal sulfide type fluorescent substance represented by these is also mentioned.

In the basic composition formula (IV), M _II is selected from the group consisting of elements that can be divalent cations, ie, alkaline earth metals, Zn (zinc), Sr (strontium), Ga (gallium), and the like. At least one element, A is Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl And at least one element selected from the group consisting of Bi (bismuth). Z is 0 <z <1.

Also,
Basic composition formula (V): M _IIa (AG) _b : zA
And metal oxoacid salt phosphors represented by the formula:

In the basic composition formula (V), _MII is a metal element that can be a cation, and (AG) is a group consisting of phosphate, borate, silicate, sulfate, tungstate, and aluminate. At least one oxo acid group selected from the group consisting of A, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Each represents at least one element selected from the group consisting of Ag (silver), Tl, and Bi (bismuth).

A and b represent all possible values depending on the valence of the metal and oxo acid group. z is 0 <z <1.
Also,
Basic composition formula (VI): M _a O _b : zA
The metal oxide fluorescent substance represented by these is mentioned.

In the basic composition formula (VI), M represents at least one element selected from metal elements that can be cations.
A is composed of Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl and Bi (bismuth). Each represents at least one element selected from the group.

A and b represent all possible values depending on the valence of the metal and oxo acid group. z is 0 <z <1.
In addition,
Basic composition formula (VII): LnOX: zA
And metal acid halide phosphors represented by the formula:

  In the basic composition formula (VII), Ln represents at least one element belonging to the lanthanoid, X represents at least one halogen element, A represents Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb. , Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl, and Bi (bismuth), each represents at least one element. Z is 0 <z <1.

  The material constituting the phosphor is not particularly limited as long as it can efficiently convert the energy of X-rays incident from the outside into light. Therefore, as long as the above conditions are satisfied, various conventionally known phosphors can be used as the scintillator. Among them, cesium iodide (CsI), gadolinium sulfate (GOS), cadmium tungstate (CWO), gadolinium silicate, and the like. (GSO), bismuth germanate (BGO), lutetium silicate (LGO), lead tungstate (PWO) and the like can be suitably used. Note that the scintillator used in the present invention is not limited to an instantaneous light emitting phosphor such as CsI, and may be a stimulable phosphor such as cesium bromide (CsBr) depending on applications.

  In the present invention, among these materials, CsI is preferable because it can constitute a phosphor having a relatively high efficiency in converting the energy of radiation such as X-rays into visible light. In the present invention, it is preferable that CsI is used as a phosphor base material and an activator is included together with this. The concentration of the activator is shown in mol%.

As the activator, those containing thallium (Tl), europium (Eu), indium (In), lithium (Li), potassium (K), rubidium (Rb), sodium (Na) and the like are preferable. These activators are present in the scintillator in the elemental state. As the activator, for example, thallium iodide (TlI), thallium bromide (TlBr), thallium chloride (TlCl), thallium fluoride (TlF, TlF ₃ ) or the like is used.

  The activator preferably contains at least thallium. When thallium is included, the wavelength of fluorescence when irradiated with X-rays is not shifted, the detection accuracy of fluorescence by the photoelectric conversion element is high, and the decrease in light reflectance after irradiation at 520 nm is reduced. Therefore, it is possible to obtain a scintillator that satisfies the predetermined light reflectance defined in the present invention.

  In the present invention, the phosphor layer may be composed of one layer or may be composed of two or more layers. Further, it may be composed of only a phosphor layer, or it may be composed of an underlayer and a phosphor layer, and the phosphor underlayer and the phosphor layer are laminated in this order on a base. You may have. When the phosphor base layer is included, these layers may be made of the same material or different materials as long as the phosphor base material compound is the same. The phosphor underlayer may be included in the base 1.

  That is, the phosphor layer may be a single layer consisting entirely of the phosphor base material, or may be a single layer containing the phosphor base compound and the activator as a whole. A phosphor underlayer comprising only a phosphor, and a phosphor layer containing a phosphor matrix compound and an activator, and under a retreat with a phosphor matrix compound and a first activator You may consist of a base layer and the fluorescent substance layer containing a fluorescent substance base material compound and a 2nd activator.

  In the phosphor layer according to the present invention, it is desirable that the relative content of the activator is an optimum amount according to the target performance and the like, but 0.001 mol% to 50 mol% with respect to the phosphor content. Furthermore, it is preferable that it is 0.1-10.0 mol%. When the concentration of the activator is 0.001 mol% or more with respect to the phosphor, the emission luminance is improved as compared with the case where the phosphor is used alone, which is preferable in terms of obtaining the target emission luminance. Moreover, it is preferable that it is 50 mol% or less because the properties and functions of the phosphor can be maintained.

  The relative content of the activator in the phosphor underlayer is preferably from 0.01 to 1 mol%, more preferably from 0.1 to 0.7 mol%. In particular, the relative content of the activator of the phosphor underlayer is preferably 0.01 mol% or more from the viewpoint of improvement in light emission luminance and storage stability. Further, it is very preferable that the relative content of the activator in the phosphor underlayer is lower than the relative content in the entire phosphor layer, and the activator in the phosphor underlayer relative to the relative content of the activator in the phosphor layer The molar ratio of relative content ((relative content of activator in phosphor underlayer) / (relative content in phosphor layer)) is preferably 0.1 to 0.7.

The phosphor layer is formed directly on the photoelectric conversion element.
As a method of directly forming the phosphor layer, a method of forming a coating film by applying a liquid formed by mixing phosphor powder with a binder resin or the like, or by regularly processing the liquid or the coating film is used. It is possible to use a method of forming a film having an array structure, a method of forming a crystal film using various vapor deposition methods, a transfer of a separately manufactured scintillator layer, and the like.

  Examples of the vapor deposition method include a physical vapor deposition (PVD) method and a chemical vapor deposition (CVD) method. The PVD method includes methods such as heat deposition, sputtering, and ion plating. In the CVD method, a raw material gas is reacted to form a thin film. In plasma CVD, which is one of the CVD methods, a gas is converted into plasma with electromagnetic energy to form a phosphor layer composed of columnar crystals. It is also possible to form a phosphor layer by attaching crystals formed on the sheet.

  In addition, it is preferable that the thickness of a fluorescent substance layer is 100-800 micrometers, and it is more preferable that it is 120-700 micrometers from the point from which the characteristic of a brightness | luminance and sharpness is acquired with sufficient balance. The layer thickness of the phosphor base layer is preferably 0.1 μm to 50 μm, and more preferably 5 μm to 40 μm from the viewpoint of maintaining high brightness and sharpness.

Resin layer 3
A resin layer is disposed on the opposite side of the phosphor layer from the photoelectric conversion element. The resin layer protects the phosphor layer and functions as a reflection layer, and can directly reflect the light emitted from the phosphor layer, so that sharpness is improved.
The resin layer is configured by dispersing light scattering particles in a binder resin.

  As the binder resin, an easily adhesive polymer such as urethane, 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 derivative (nitrocellulose, etc.), styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea resin, melamine resin, phenoxy resin, silicone Examples thereof include resins, acrylic resins, urea formamide resins, and the like.

  Especially, it is preferable that at least 1 sort (s) chosen from an acrylic resin, a urethane resin, and a phenol resin is included. Moreover, these binders can also be used in mixture of 2 or more types.

  The light scattering particles consist of at least one selected from a white pigment, titanium oxide, zinc oxide, lead oxide, magnesium oxide, aluminum oxide, barium oxide, iron oxide, carbon black, polycyclic pigment, azo pigment, and lake pigment. Things are used.

Examples of the white pigment include TiO ₂ (anatase type, rutile type), MgO, PbCO ₃ · Pb (OH) ₂ , BaSO ₄ , Al ₂ O ₃ , M (II) FX (where M (II) is Ba). , Sr and Ca, and X is a Cl atom or a Br atom.), CaCO ₃ , ZnO, Sb ₂ O ₃ , SiO ₂ , ZrO ₂ , lithopone (BaSO _4. ZnS), magnesium silicate, basic silicic acid sulfate, basic lead phosphate, aluminum silicate and the like can be used. These white pigments may be used alone or in combination.

  The primary particle size of the light scattering particles is preferably in the range of 0.1 to 0.5 μm, more preferably in the range of 0.2 to 0.3 μm. Further, the light scattering particles are particularly preferably those that have been surface-treated with an oxide such as Al, Si, Zr, and Zn in order to improve the affinity and dispersibility with the polymer and to suppress the deterioration of the polymer.

  The resin layer can be formed by heating and coating the mixture containing the light scattering particles and the binder resin. At this time, a hot melt resin is preferably used as the binder resin. As the hot melt resin, for example, a resin mainly composed of polyolefin, polyamide, polyester, polyurethane, or acrylic resin can be used. Among these, those containing a polyolefin resin as a main component are preferred from the viewpoints of light transmittance, moisture resistance and adhesiveness. Examples of polyolefin resins include ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-acrylic acid ester copolymer (EMA), and ethylene-methacrylic acid copolymer ( EMAA), ethylene-methacrylic acid ester copolymer (EMMA), ionomer resin and the like can be used. In addition, you may use these resin as what is called a polymer blend combining 2 or more types.

The coating means for the composition for forming the resin layer is not particularly limited, but a normal coating means such as a doctor blade, roll coater, knife coater, extrusion coater, die coater, gravure coater, lip coater, capillary A type coater, a bar coater, etc. can be used.
The thickness of the resin layer is preferably 10 to 500 μm from the viewpoint of luminance and surface smoothness, but is not limited thereto.

Moisture-proof layer 4
If a moisture-proof layer has a moisture-proof function, it can use without a restriction | limiting in particular of an inorganic material and an organic material. Of these, a metal thin film is preferable. Specific examples of the metal material that can form such a metal thin film include aluminum, titanium, cobalt, nickel, magnesium, stainless steel, silver, gold, platinum, and palladium. Among these, it is particularly preferable that aluminum is a main component. Here, the metal material which comprises a metal thin film layer has the form of the metal single-piece | unit or its alloy in the typical aspect of this invention.

A moisture-proof layer composed of a metal thin film has high moisture-proof performance. Moreover, you may comprise a moisture-proof layer with the material similar to the protective layer mentioned later.
As a method for providing the moisture-proof layer on the surface of the support, a method using a known process such as vapor deposition or sputtering, or a metal such as aluminum can be formed into a thin film and attached later. In addition, the metal foil can be pressure-bonded via an adhesive, but if the adhesive is present, light absorption may occur and the amount of light may be reduced. From such a viewpoint, sputtering is preferable.
The thickness of the moisture-proof layer is not particularly limited, and is appropriately selected according to the configuration of the moisture-proof layer to be formed. For example, the thickness is 0.005 to 0.3 μm, more preferably 0.01 to 0.2 μm, but not limited thereto.

Thermosetting resin layer 5
The thermosetting resin layer is usually in a completely cured state, but may be semi-cured or uncured. However, the generation amount of the volatile organic compound (VOC) in the thermosetting resin layer after curing is 0.5 g / m ² or less. This VOC is derived from uncured monomers, oligomers or residual solvents, etc., and varies depending on the type of thermosetting resin. In the present invention, the VOC measured under the following predetermined conditions is Since the thermosetting resin layer in the range has few volatile components, it can provide stable adhesion.

  VOC is measured by producing a cured product with the same thickness as the actual thermosetting resin layer under the same curing conditions, collecting a specified area, and heating it at 150 ° C for 60 minutes. Is measured according to JIS K 0151 (infrared gas analysis) to obtain VOC.

  The thermosetting resin constituting the thermosetting resin layer has a thermosetting reactive group, such as diallyl phthalate resin, phenol resin, urea resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, Examples thereof include an epoxy resin, an amino alkyd resin, a melamine-urea cocondensation resin, a silicon resin, and a polysiloxane resin.

When such a thermosetting resin layer is arranged, the adhesion between the moisture-proof layer and the protective layer can be improved.
The thermosetting resin layer can be formed from an uncured thermosetting resin composition by a coating method such as knife coating, hot melt coating, dipping, spin coating or spray coating, or a printing method such as screen printing. Yes, an uncured or semi-cured thermosetting resin layer may be formed on the surface of the metal layer or protective layer in advance, and heat-pressed so as to form a laminate with the object, and then bonded. . In addition, the catalyst and solvent for hardening acceleration | stimulation may be added to the thermosetting resin layer as needed, and a well-known thing can be used as a catalyst. The solvent is not particularly limited as long as it has volatility and can dissolve an uncured thermosetting resin. Moreover, the thermosetting resin composition used may be in the form of a low viscosity liquid or in the form of a high viscosity paste.
The thickness of the thermosetting resin layer is not particularly limited and is appropriately selected depending on the configuration. For example, the thickness is 1 to 500 μm, more preferably 2 to 10 μm, but not limited thereto.

  In the present invention, the linear expansion coefficient of the thermosetting resin layer is preferably 20 ppm or less, and preferably in the range of 2 to 15 ppm. Thermosetting resins having a linear expansion coefficient in this range are diallyl phthalate resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin and the like. Since the thermosetting resin having such a linear expansion coefficient is less deformed when the protective layer and the metal layer are joined, the adhesiveness is high and the panel is less deformed. In particular, a diallyl phthalate resin is preferable because it has a low VOC and a linear expansion coefficient satisfying a predetermined range.

  For the linear expansion coefficient, a sheet made of a thermosetting resin was prepared, heat-treated at 200 ° C. for 1 hour, and then cut into 4 mm width × 20 mm length × 90 μm thickness to obtain a measurement sample. It can evaluate by measuring a linear expansion coefficient with respect to this measurement sample on conditions with a temperature increase rate of 10 degree-C / min using TMA (TA Instruments Co., Ltd. product).

Protective layer 6
The protective layer has a function of preventing damage due to impact of the reflective layer and corrosion due to moisture, and a resin film is preferably used. As the material for the protective layer, materials that can be generally used as engineering plastics can be used. For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polyester, polybutylene terephthalate (PBT), polyetherimide, polycarbonate Etc. Although the thickness of a protective layer should just be 10-100 micrometers, it does not restrict | limit in particular.

Manufacturing method of radiation image conversion panel The manufacturing method of the radiation image conversion panel according to the present invention includes:
A scintillator assy creation step for forming a phosphor layer 2 on a base 1 in which a plurality of photoelectric conversion elements are two-dimensionally arranged;
Forming a resin layer 3 on the phosphor layer 2 of the scintillator assy, applying a mixture of light scattering particles dispersed in a binder resin;
A moisture-proof layer assy forming step of forming the thermosetting resin layer 5 and the moisture-proof layer 4 in this order on at least one surface of the protective layer 6;
It includes a bonding step in which the resin layer 3 side of the scintillator assy and the moisture-proof layer 4 side of the moisture-proof layer assy are bonded to face each other.

“Assy” is an abbreviation for assembly.
(i) Scintillator assy creation step The phosphor layer 2 is formed on the base 1 in which the plurality of photoelectric conversion elements described above are two-dimensionally arranged.
In order to protect the photoelectric conversion element, an element protective layer and a base layer may be provided on the base as necessary.

As described above, the vapor deposition method is preferably employed as the method for forming the phosphor layer. However, even if the phosphor layer is directly formed on the base, the vapor deposited phosphor layer on the polymer film is not used. You may transcribe | transfer on a base.
In this way, the scintillator assy is formed.

(ii) Step of forming resin layer On the phosphor layer, a resin layer is formed by applying a mixture of light scattering particles dispersed in a binder resin. As the coating method, the above-described coating method is adopted. Further, for the purpose of removing the solvent contained in the composition or for the purpose of flattening the surface of the resin layer, a heat treatment may be performed during or after the formation of the resin layer. The heating temperature is not particularly limited as long as the solvent volatilizes or the binder resin melts.

(iii) Moisture-proof layer assy formation step Separately from the scintillator assy, the film substrate constituting the protective layer is coated with an uncured thermosetting resin composition, and the moisture-proof layer is formed on the formed thermosetting resin layer. Form. When the moisture-proof layer is a metal layer, the moisture-proof layer is formed by employing a vapor deposition method or the like. In this way, the moisture-proof layer assy is formed.
In the moisture-proof layer assy forming step, the thermosetting resin may be cured by heating, or may be cured in the subsequent bonding step.

(iv) Bonding step The resin layer side of the scintillator assy and the moisture-proof layer side of the moisture-proof layer assy are bonded to face each other.

At the time of bonding, defoaming is preferably performed so that bubbles do not enter between layers. Defoaming is performed by bonding under pressure by an autoclave or the like.
After contact, heat is applied while applying pressure as necessary. If the resin layer contains a hot melt resin, the resin layer and the moisture-proof layer are bonded by this heating. Moreover, hardening of a thermosetting resin is accelerated | stimulated and the adhesiveness of a protective layer and a metal layer improves.

A radiation image conversion panel is formed through this bonding process.
The above radiographic image conversion panel can be applied to various types of X-ray imaging systems.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to this.
[Example 1]
After forming an element protective layer made of SiN on a base (glass substrate, thickness 500 μm) provided with a two-dimensional photoelectric conversion array, a columnar crystal layer of a scintillator phosphor made of CsI: Tl using a vacuum deposition method ( A scintillator assy was prepared by forming a thickness of 300 μm.

  Separately from this, a PET resin film serving as a protective layer: after coating with a thickness of 500 μm a diallyl phthalate (DAP) resin composition (Daisodap) as a thermosetting resin layer to a thickness of 4 μm, the DAP On the resin layer, an aluminum layer having a thickness of 30 μm was formed as a moisture-proof layer by vapor deposition to prepare a moisture-proof film assy.

On the scintillator assy, a composition in which hot melt resin (manufactured by Moresco) is the main component and TiO ₂ is dispersed as light scattering particles so as to be 60% by mass is applied by a knife coater, and the thickness is 30 μm. The resin layer was formed.

  On the scintillator assy to which the resin layer is applied, the moisture-proof film assy is defoamed so that the metal layer faces the resin layer side, and after adhering, the hot melt layer is heated to 100 ° C. in a clean oven The radiation image conversion panel was created by performing adhesion and thermosetting resin curing.

[Comparative Example 1]
A moisture-proof layer assy was prepared by directly depositing an aluminum layer as a moisture-proof layer on the same kind of PET resin film as in Example 1, and a scintillator assy similar to that in Example 1 was formed from a resin layer made of a hot-melt resin in which light scattering particles were dispersed. A radiographic image conversion panel was prepared by bonding through the substrate.

[Comparative Example 2]
After applying a polyester resin (Toyobo “Byron”) to the same kind of PET resin as in Example 1 and drying, a moisture-proof film assy in which an aluminum layer was deposited on the polyester resin layer was prepared. A radiation image conversion panel was prepared by adhering the same scintillator assy as in Example 1 via a hot melt layer in which light scattering particles were dispersed.

[VOC measurement]
VOC generation amounts of the DAP layer and the polyester layer produced as the thermosetting resin layer in Example 1 and Comparative Example 2 were measured according to JIS K0151. The linear expansion coefficient is also shown in the table.

[Temperature history test]
The radiation image conversion panels described in Example 1, Comparative Example 1 and Comparative Example 2 were put in the same environmental test apparatus, and each hour was performed in the order of 25 ° C. → 70 ° C. → 25 ° C. → -10 ° C. → 25 ° C. The pattern was repeated 100 times with a pattern of repeated temperature holding. After taking out from the environmental test apparatus, the occurrence of peeling between the aluminum layer and the PET resin layer was investigated using an optical microscope.
The results are shown in Table 2.

Claims (7)

A radiation image conversion panel,
A base in which a plurality of photoelectric conversion elements are two-dimensionally arranged;
A phosphor layer disposed on the photoelectric conversion element side of the base;
A resin layer disposed on the opposite side of the phosphor layer from the photoelectric conversion element, in which light scattering particles are dispersed in a binder resin;
A moisture-proof layer disposed on the opposite side of the resin layer from the photoelectric conversion element;
It consists of a protective layer disposed on the opposite side of the moisture-proof layer to the photoelectric conversion element,
A thermosetting resin layer is disposed between the moisture-proof layer and the protective layer, and the amount of volatile organic substances (VOC) generated in the thermosetting resin layer is 0.5 g / m ² or less. A radiation image conversion panel. In the radiation conversion panel described above, the light scattering particles include white pigment, titanium oxide, zinc oxide, lead oxide, magnesium oxide, aluminum oxide, barium oxide, iron oxide, carbon black, polycyclic pigment, azo pigment, lake. Including at least one selected from pigments;
The radiation image conversion panel according to claim 1, wherein the binder resin includes at least one selected from an acrylic resin, a urethane resin, and a phenol resin.   The radiation image conversion panel according to claim 1, wherein the moisture-proof layer is made of a metal thin film.   The protective layer is at least one resin selected from polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polyimide resin, polyester resin, polybutylene terephthalate (PBT) resin, polyetherimide resin, and polycarbonate resin. The radiation image conversion panel according to any one of claims 1 to 3, wherein the radiation image conversion panel is configured.   The thermosetting resin layer is at least one selected from diallyl phthalate resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, and epoxy resin. The radiation image conversion panel according to item 1.   The radiation image conversion panel according to claim 1, wherein the thermosetting resin layer has a linear expansion coefficient of 20 ppm or less. A scintillator assy creation process for forming a phosphor layer on a base in which a plurality of photoelectric conversion elements are two-dimensionally arranged,
On the phosphor layer of the scintillator assy, a resin layer forming step of applying a mixture in which light scattering particles are dispersed in a binder resin;
A moisture-proof layer assy forming step of forming a thermosetting resin layer and a moisture-proof layer in this order on at least one surface of the protective layer;
A bonding step of bonding the resin layer side of the scintillator assy and the moisture-proof layer side of the moisture-proof layer assy to face each other,
The manufacturing method of the radiographic image conversion panel characterized by including these.

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