JP2011064699A - Radiation image conversion panel and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation image conversion panel having improved adhesion between a support and a phosphor layer formed by a vapor deposition method, and a method of manufacturing the same. <P>SOLUTION: In the method of manufacturing the radiation image conversion panel by forming the phosphor layer having a thickness of 50 μm or more on the support by the vapor deposition method, the phosphor layer is formed by vapor deposition of a matrix and an activator, the degree of vacuum in a vapor deposition apparatus including an air exhauster, a pressure controlling gas introducer, and a pressure controlling gas flow rate adjuster is 1.33×10<SP>-2</SP>to 1.33 Pa, the flow rate of the pressure controlling gas is 0.001 to 1,000 sccm (sccm: standard cc/min (1×10<SP>-6</SP>m<SP>3</SP>/min)), and a phosphor contained in the phosphor layer contains a columnar crystal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radiation image conversion panel using a phosphor and a method for producing the same, and more particularly to a radiation image conversion panel having improved adhesion between a phosphor layer formed by vapor deposition and a support and a method for producing the same.

  Radiation images such as X-ray images are often used in fields such as disease diagnosis. The X-ray image is obtained by irradiating the phosphor layer (phosphor screen) with X-rays that have passed through the subject, thereby generating visible light, and then using this visible light as when taking a normal photograph. Thus, a so-called radiographic method in which a silver halide photographic light-sensitive material (hereinafter also simply referred to as a light-sensitive material) is irradiated and then developed to obtain a visible silver image is widely used.

  However, in recent years, a new method for taking out an image directly from a phosphor layer has been proposed instead of an image forming method using a photosensitive material having a silver halide salt.

  In this method, the radiation transmitted through the subject is absorbed by the phosphor, and then the phosphor is excited by light or heat energy, for example, so that the radiation energy accumulated by the absorption is emitted as fluorescence. There is a method for detecting and imaging this fluorescence.

  Specifically, for example, a radiation image conversion method using a stimulable phosphor as described in U.S. Pat. No. 3,859,527 and JP-A-55-12144 is known.

  This method uses a radiation image conversion panel containing a photostimulable phosphor. The radiation transmission density of each part of the subject is obtained by applying radiation transmitted through the subject to the photostimulable phosphor layer of the radiation image conversion panel. Is stored in the stimulable phosphor by chronologically exciting the stimulable phosphor with electromagnetic waves (excitation light) such as visible light and infrared light. Radiation energy is emitted as stimulated emission, and a signal based on the intensity of the light is photoelectrically converted to obtain an electrical signal, which is then used as a recording material such as a silver halide photographic material, or a display device such as a CRT. It is reproduced as a visible image on the top.

  According to the above radiographic image reproduction method, it is possible to obtain a radiographic image with a much smaller exposure dose and abundant information as compared with the radiographic method using a combination of a conventional radiographic film and an intensifying screen. Has the advantage of being able to

  Thus, the stimulable phosphor is a phosphor that exhibits stimulating light emission when irradiated with excitation light after being irradiated with radiation, but practically, with excitation light having a wavelength in the range of 400 to 900 nm, Phosphors exhibiting stimulated emission in the wavelength range of 300 to 500 nm are generally used.

  Radiation image conversion panels using these photostimulable phosphors release accumulated energy by scanning excitation light after accumulating radiation image information, so that radiation images can be accumulated again after scanning. Can be used. In other words, the conventional radiographic method consumes a radiographic film for each photographing, whereas this radiographic image conversion method repeatedly uses a radiographic image conversion panel, so that also from the viewpoint of resource protection and economic efficiency. It is advantageous.

  The superiority or inferiority of the radiation image conversion method using the radiation image conversion panel depends greatly on the stimulable emission luminance of the radiation image conversion panel and the light emission uniformity of the panel. In particular, these characteristics are the characteristics of the stimulable phosphor used. Is known to be largely dominated.

  In the radiation image conversion panel used under various conditions, the adhesion between the support and the phosphor layer is one of the important characteristics. Japanese Patent Publication No. 4-44959 discloses a cross-linking agent between the support and the phosphor layer. Although a method for providing a subbing layer containing benzene is disclosed, simply providing a subbing layer causes a diffusion of a solvent contained in the phosphor layer during the drying process of the phosphor layer coated thereon. The surface layer of the phosphor layer becomes non-uniform due to dissolution or deformation of the undercoat layer, resulting in image unevenness.

  In addition, in the process of manufacturing the phosphor sheet, after forming the undercoat layer on the support, it is wound up in a state where it is once laminated in a roll shape, or is formed into a sheet size of a prescribed size, and these are laminated and stored. When stored in a laminated state for a certain period of time, a failure occurs that causes a blocking phenomenon between the undercoat layer and the back surface of the upper support and causes adhesion.

  Thus, in the radiographic image conversion panel, development of the radiographic image conversion panel improved in adhesiveness with a support is desired.

  The present invention has been made in view of the above problems, and an object thereof is to provide a radiation image conversion panel having improved adhesion between a phosphor layer formed by vapor deposition and a support, and a method for producing the same. is there.

  The above object of the present invention is achieved by the following configurations.

1. In a method for producing a radiation image conversion panel having a phosphor plate and a protective layer produced by forming a phosphor layer having a thickness of 50 μm or more on a support by vapor deposition, the phosphor layer comprises a matrix and an activator. Formed by vapor deposition, while evacuating using a vacuum pump, pressure-regulating gas is introduced from the gas introduction part via the pressure-regulating gas flow rate regulating device, and the degree of vacuum in the vapor deposition device is 1.33 × 10 ⁻² to 1.33 Pa, the flow rate of the pressure adjusting gas is 0.001 to 1000 sccm (sccm: standard cc / min (1 × 10 ⁻⁶ m ³ / min)), and the phosphor contained in the phosphor layer is a columnar crystal. And a low-refractive index layer is provided between the surface of the phosphor layer and the protective layer.

  2. 2. The method for producing a radiation image conversion panel according to 1, wherein a low refractive index layer is provided on a side edge portion of the phosphor plate via a spacer.

  3. 3. The method for producing a radiation image conversion panel according to 1 or 2, wherein the side edges of the support and the protective layer are bonded using an adhesive.

  4). 4. The method for producing a radiation image conversion panel according to any one of 1 to 3, wherein the pressure adjusting gas is nitrogen or argon.

  5. 5. The method for producing a radiation image conversion panel according to any one of 1 to 4, wherein the phosphor layer contains a phosphor represented by the following general formula (1).

General formula (1)
M ¹ X · aM ² X ′ ₂ · bM ³ X ″ ₃ : eA
[Wherein M ¹ is at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs, and M ² is Be, Mg, Ca, Sr, Ba, Zn, Cd, Cu and At least one divalent metal selected from the group consisting of Ni, and M ³ is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga and In are at least one trivalent metal selected from the group consisting of In, and X, X ′ and X ″ are at least one selected from the group consisting of F, Cl, Br and I, respectively. A is a group consisting of Eu, Tb, In, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na, Ag, Cu and Mg At least one metal selected from , A, b, e each represent a number between 0 ≦ a <0.5,0 ≦ b <0.5,0 <e ≦ 0.2.]
6). 6. The method for producing a radiation image conversion panel as described in 5 above, wherein M ¹ in the general formula (1) is at least one alkali metal selected from the group consisting of K, Rb and Cs.

  7. 7. The method for producing a radiation image conversion panel as described in 5 or 6 above, wherein X in the general formula (1) is at least one halogen selected from Br and I.

8). The radiation image according to any one of 5 to 7, wherein M ² in the general formula (1) is at least one divalent metal selected from Be, Mg, Ca, Sr, and Ba. A method for manufacturing a conversion panel.

9. M ³ in the general formula (1) is at least one trivalent metal selected from the group consisting of Y, Ce, Sm, Eu, Al, La, Gd, Lu, Ga and In The manufacturing method of the radiographic image conversion panel of any one of 5-8.

10. B in the said General formula (1) is 0 <= b <= 10 < ^-2 >, The manufacturing method of the radiographic image conversion panel of any one of said 5-9 characterized by the above-mentioned.

  11. The radiation according to any one of 5 to 10, wherein A in the general formula (1) is at least one metal selected from the group consisting of Eu, Ce, Sm, Tl, and Na. Manufacturing method of image conversion panel.

  12 12. The method for producing a radiation image conversion panel as described in 11 above, wherein the columnar crystal contains a phosphor represented by the following general formula (2).

General formula (2)
CsX: yA
[Wherein, X represents Br or I, and A represents Eu, In, Tb or Ce. y represents a numerical value from 1 × 10 ⁻⁷ to 1 × 10 ⁻² . ]
13. A radiation image conversion panel manufactured by the method for manufacturing a radiation image conversion panel according to any one of 1 to 12 above.

  According to the present invention, a radiation image conversion panel having improved adhesion between a phosphor layer formed by vapor deposition and a support and a method for producing the same can be provided.

It is sectional drawing of a photostimulable phosphor plate. It is a figure which shows a mode that a stimulable fluorescent substance layer is formed by vapor deposition on a support body. It is the schematic which shows the usage example of the radiographic image conversion panel of this invention. It is the schematic of a vapor deposition apparatus.

In the method for producing a radiation image conversion panel having a phosphor plate and a protective layer produced by forming a phosphor layer having a thickness of 50 μm or more on a support by a vapor deposition method, the phosphor layer Is formed by vapor-depositing the base material and the activator, and while evacuating using a vacuum pump, pressure-regulating gas is introduced from the gas introduction part via the pressure-regulating gas flow rate control device, and the degree of vacuum in the vapor deposition device is 1. 33 × 10 ^{−2 to} 1.33 Pa, and the flow rate of the pressure adjusting gas is 0.001 to 1000 sccm (sccm: standard cc / min (1 × 10 ⁻⁶ m ³ / min)), and is included in the phosphor layer The phosphor to be used contains a columnar crystal and a low refractive index layer is provided between the surface of the phosphor layer and the protective layer, thereby causing little deterioration in sensitivity and sharpness. It has been found that the adhesion of is improved.

  Hereinafter, the present invention will be described in detail.

  First, formation of the photostimulable phosphor layer by the vapor deposition method will be described.

  As a method for vapor-depositing the photostimulable phosphor, there is an evaporation method.

In the vapor deposition method, a support is placed in a vapor deposition apparatus, the inside of the apparatus is evacuated to a vacuum of about 1.33 × 10 ⁻⁴ Pa, and then a pressure-regulating gas is introduced to increase the degree of vacuum in the vapor deposition apparatus. A vacuum of about 1.33 × 10 ^{−2 to} 1.33 Pa is applied, and then the photostimulable phosphor matrix and activator are heated and evaporated by a resistance heating method, an electron beam method, or the like to stimulate the surface of the support. The phosphor layer is deposited to a desired thickness. As a result, a photostimulable phosphor layer that does not contain a binder is formed.

  In the present invention, the photostimulable phosphor layer is formed by these vapor deposition methods, but the phosphor layer can be formed in a plurality of times.

  In the present invention, a vapor deposition method is used. Hereinafter, formation of the photostimulable phosphor layer by vapor deposition will be described in detail. In the following, the case of growing columnar crystals will be described.

As a method for forming a photostimulable phosphor layer by vapor deposition, a pressure control gas is introduced so that the degree of vacuum in the vapor deposition apparatus is 1.33 × 10 ⁻² to 1.33 Pa. A stimulable phosphor layer having an independent elongated columnar crystal structure can be obtained by a method in which vapor or raw materials of a stimulable phosphor and an activator are supplied at a certain incident angle and a crystal is grown in a vapor phase.

It is necessary that the flow rate of the pressure adjusting gas that makes the degree of vacuum 1.33 × 10 ⁻² to 1.33 Pa be 0.001 to 1000 sccm. When the flow rate of the regulated gas exceeds 1000 sccm, the vapor flow is disturbed by the gas flow, which adversely affects the growth of the phosphor. Further, if the flow rate of the pressure adjusting gas is less than 0.001 sccm, the adhesiveness is reduced.

  The pressure adjusting gas used for adjusting the degree of vacuum is preferably nitrogen or argon.

  In the method of supplying the vapor flow of the stimulable phosphor or the stimulable phosphor raw material at an incident angle with respect to the support surface, the support is arranged to be inclined with respect to the crucible charged with the evaporation source. Alternatively, it is possible to adopt a method in which the support and the crucible are installed in parallel with each other, and only an oblique component is regulated to be deposited on the support by a slit or the like from the evaporation surface of the crucible charged with the evaporation source.

  In these cases, it is preferable that the distance between the shortest part of the support and the crucible is set to approximately 10 to 60 cm in accordance with the average range of the stimulable phosphor.

  In order to improve the modulation transfer function (MTF) in the photostimulable phosphor layer composed of these columnar crystals, the size of the columnar crystals (the columnar crystals when the columnar crystals are observed from a plane parallel to the support) is used. The average diameter of the cross-sectional area in terms of a circle, calculated from a micrograph containing at least 100 columnar crystals in the field of view, is preferably about 1 to 50 μm, and more preferably 1 to 30 μm. That is, when the columnar crystal is thinner than 1 μm, the excitation excitation light is scattered by the columnar crystal, so that the MTF decreases. When the columnar crystal exceeds 50 μm, the directivity of the excitation excitation light decreases, and the MTF Will decline.

  Further, the size of the gap between the columnar crystals is preferably 30 μm or less, more preferably 5 μm or less. That is, when the gap exceeds 30 μm, the filling rate of the photostimulable phosphor in the photostimulable phosphor layer is lowered and the sensitivity is lowered.

  The thickness of the stimulable phosphor layer formed by the above method varies depending on the sensitivity of the intended radiation image conversion panel to radiation, the type of stimulable phosphor, etc., but is preferably 10 to 1000 μm, more preferably 20 ˜800 μm.

  In addition, when the stimulable phosphor layer is produced using the above-described vapor deposition method, the stimulable phosphor base material and activator that becomes the evaporation source are uniformly dissolved or molded by pressing or hot pressing into a crucible. Prepared. At this time, it is preferable to perform a degassing treatment. The method of evaporating the stimulable phosphor matrix and the activator from the evaporation source is performed by scanning an electron beam emitted by an electron gun, but it can also be evaporated by other methods.

  The evaporation source is not necessarily a stimulable phosphor, and may be a mixture of a stimulable phosphor material.

  Further, the activator may be vapor-deposited by mixing an activator with a basic substance.

  In addition, the gap between the columnar crystals may be filled with a filler or the like, which reinforces the photostimulable phosphor layer. Further, a substance having a high light absorption rate, a substance having a high light reflectance, or the like may be filled. As a result, the reinforcing effect can be provided, and the lateral diffusion of the excitation light incident on the stimulable phosphor layer can be almost completely prevented.

  A substance having high light reflectance means a material having a high reflectance with respect to stimulated excitation light (500 to 900 nm, particularly 600 to 800 nm), such as white pigment and green to red, such as aluminum, magnesium, silver, indium and other metals. Area colorants can be used.

White pigments can also reflect stimulated emission. As white pigments, 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 At least one of Ca, and X is at least one of Cl and Br.), CaCO ₃ , ZnO, Sb ₂ O ₃ , SiO ₂ , ZrO ₂ , lithopone (BaSO ₄ .ZnS) , Magnesium silicate, basic lead silicic acid sulfate, basic lead phosphate, aluminum silicate and the like. Since these white pigments have strong hiding power and a high refractive index, they can easily scatter stimulated luminescence by reflecting or refracting light, and can significantly improve the sensitivity of the resulting radiation image conversion panel.

  Moreover, as a substance having a high light absorption rate, for example, carbon, chromium oxide, nickel oxide, iron oxide and the like and a blue color material are used. Among these, carbon absorbs light emission.

The color material may be either an organic or inorganic color material. Examples of organic colorants include Zavon First Blue 3G (Hoechst), Estrol Brill Blue N-3RL (Sumitomo Chemical), D & C Blue No. 1 (made by National Aniline), Spirit Blue (made by Hodogaya Chemical), Oil Blue No. 1 603 (made by Orient), Kitten Blue A (made by Ciba Geigy), Eisen Katyron Blue GLH (made by Hodogaya Chemical), Lake Blue AFH (made by Kyowa Sangyo), Primocyanin 6GX (made by Inabata Sangyo), Brill Acid Green 6BH (Hodogaya) Chemical Blue), Cyan Blue BNRCS (Toyo Ink), Lionoyl Blue SL (Toyo Ink), etc. are used. The color index No. 24411, 23160, 74180, 74200, 22800, 23154, 23155, 24401, 14830, 15050, 15760, 15707, 17941, 74220, 13425, 13361, 13420, 11836, 74140, 74380, 74350, 74460, etc. Materials are also mentioned. Examples of inorganic color materials include ultramarine blue, cobalt blue, cerulean blue, chromium oxide, and TiO ₂ —ZnO—Co—NiO pigments.

  As the support used in the radiation image conversion panel of the present invention, various glasses, polymer materials, metals and the like are used. For example, plate glass such as quartz, borosilicate glass and chemically tempered glass, and cellulose acetate film , Polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, polycarbonate film and other plastic films, aluminum sheets, iron sheets, copper sheets and other metal sheets or metal sheets having a coating layer of the metal oxide are preferable. . The surface of these supports may be a smooth surface, or may be a mat surface for the purpose of improving the adhesion to the stimulable phosphor layer.

  Moreover, in this invention, in order to improve the adhesiveness of a support body and a photostimulable phosphor layer, you may provide an adhesive layer in advance on the surface of a support body as needed. The thickness of these supports varies depending on the material of the support used, but is generally 80 to 2000 μm, and more preferably 80 to 1000 μm from the viewpoint of handling.

  The radiation image conversion panel according to the present invention may have a protective layer on the photostimulable phosphor layer.

The protective layer may be formed by directly applying a coating solution for the protective layer on the photostimulable phosphor layer, or a protective layer separately formed in advance may be adhered on the photostimulable phosphor layer. Or you may take the procedure of forming a photostimulable phosphor layer on the protective layer formed separately. Materials for the protective layer include cellulose acetate, nitrocellulose, polymethyl methacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyester, polyethylene terephthalate, polyethylene, polyvinylidene chloride, nylon, polytetrafluoroethylene, polytrifluoride-ethylene chloride Ordinary protective layer materials such as tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-acrylonitrile copolymer are used. In addition, a transparent glass substrate can be used as the protective layer. Further, this protective layer may be formed by laminating inorganic substances such as SiC, SiO ₂ , SiN, Al ₂ O ₃ by vapor deposition, sputtering, or the like. The thickness of these protective layers is generally preferably about 0.1 to 2000 μm.

Examples of stimulable phosphors that can be used in the vapor deposition method include phosphors represented by BaSO ₄ : Ax described in JP-A-48-80487, and MgSO described in JP-A-48-80488. ₄ : phosphor represented by Ax, SrSO ₄ described in JP-A-48-80489: phosphor represented by Ax, Na ₂ SO ₄ described in JP-A-51-29889, Phosphors obtained by adding at least one of Mn, Dy and Tb to CaSO ₄ and BaSO ₄ etc., phosphors such as BeO, LiF, MgSO ₄ and CaF ₂ described in JP-A No. 52-30487, Li ₂ B ₄ O ₇ : Phosphor such as Cu, Ag described in Kaisho 53-39277, Li ₂ O. (Be ₂ O ₂ ) x described in JP 54-47883: Cu, A Phosphors etc., are described in U.S. Pat. No. 3,859,527 SrS: Ce, Sm, SrS : Eu, Sm, La 2 O 2 S: Eu, Sm and (Zn, Cd) S: at Mnx And phosphors represented. Further, a ZnS: Cu, Pb phosphor described in JP-A-55-12142, a barium aluminate phosphor represented by the general formula BaO.xAl ₂ O ₃ : Eu, and a general formula represented by M ( II) Alkaline earth metal silicate phosphors represented by O.xSiO ₂ : A are mentioned.

Further, an alkaline earth fluorohalide phosphor represented by the general formula (Ba _1-xy Mg _x Ca _y ) F _x : Eu ²⁺ described in JP-A No. 55-12143, A phosphor in which the general formula described in JP-A-55-12144 is represented by LnOX: xA, and a general formula described in JP-A-55-12145 is (Ba _1-x M (II) _x ) F a phosphor represented by _x : yA, a phosphor represented by BaFX: xCe, yA having a general formula described in JP-A-55-84389, a general compound described in JP-A-55-160078 Rare earth element activated divalent metal fluorohalide phosphor represented by the formula M (II) FX.xA: yLn, represented by the general formula ZnS: A, CdS: A, (Zn, Cd) S: A, X Phosphor, described in JP-A-59-38278 Any one of the following general formulas xM ₃ (PO ₄ ) ₂ .NX ₂ : yA
xM ₃ (PO ₄ ) ₂ : yA
A phosphor represented by the general formula nReX ₃ · mAX ′ ₂ : xEu described in JP-A-59-155487
nReX ₃ · mAX ′ ₂ : xEu, ySm
A phosphor represented by the following general formula M (I) X · aM (II) X ′ ₂ · bM (III) X ″ ₃ : cA described in JP-A-61-72087
And a bismuth-activated alkali halide phosphor represented by the general formula M (I) X: xBi described in JP-A No. 61-228400. In particular, alkali halide phosphors are preferred because they easily form columnar photostimulable phosphor layers by methods such as vapor deposition and sputtering.

  In the present invention, stimulable phosphor particles represented by the following general formula (1) are preferred.

General formula (1)
M ¹ X · aM ² X ′ ₂ · bM ³ X ″ ₃ : eA
In the general formula (1), M ¹ is at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs, and M ² is Be, Mg, Ca, Sr, Ba, Zn, Cd. , Cu and Ni, and M ³ is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er. , Tm, Yb, Lu, Al, Ga and In, at least one trivalent metal selected from the group consisting of In, X, X ′ and X ″ are each selected from the group consisting of F, Cl, Br and I At least one halogen, and A is Eu, Tb, In, Cs, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na, Ag, Cu And at least selected from the group consisting of Mg A seed metal, also, a, b, e each represent a number between 0 ≦ a <0.5,0 ≦ b <0.5,0 <e ≦ 0.2.

Further, in the general formula (1), M ¹ is at least one alkali metal selected from the group consisting of K, Rb and Cs, and X is at least one halogen selected from Br and I. M ² is at least one divalent metal selected from Be, Mg, Ca, Sr and Ba, M ³ is Y, Ce, Sm, Eu, Al, La, Gd, Lu, Ga and In At least one trivalent metal selected from the group consisting of: b is 0 ≦ b ≦ 10 ⁻² ; and A is at least one selected from the group consisting of Eu, Cs, Sm, Tl and Na. A seed metal is preferred.

  In the present invention, the stimulable phosphor preferably has a columnar crystal, and the columnar crystal preferably has a stimulable phosphor represented by the following general formula (2) as a main component.

General formula (2)
CsX: yA
In the general formula (2), X represents Br or I, and A represents Eu, In, Tb, or Ce. y represents a numerical value from 1 × 10 ⁻⁷ to 1 × 10 ⁻² .

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a photostimulable phosphor plate. Reference numeral 10 denotes a support, and 11 denotes a stimulable phosphor layer, which shows columnar crystals. Reference numeral 12 denotes a gap formed between the columnar crystals.

FIG. 2 is a diagram showing a state in which a photostimulable phosphor layer is formed on a support by vapor deposition. When the stimulable phosphor vapor flow V is incident in the normal direction of the support surface, columnar crystals perpendicular to the normal direction of the support surface are formed. Assuming that the incident angle of the stimulable phosphor vapor flow V with respect to the normal direction of the support surface is θ ₂ , the angle of the formed columnar crystal with respect to the normal direction of the support surface is represented by θ ₁ , and at this angle the columnar crystal Is formed. In the present invention, vertical columnar crystals of 0 ≦ θ ₁ and θ ₂ ≦ 20 are preferable.

  FIG. 3 is a schematic view showing an example of use of the radiation image conversion panel of the present invention.

  In FIG. 3, 21 is a radiation generator, 22 is a subject, 23 is a radiation image conversion panel having a visible or infrared photostimulable phosphor layer containing a stimulable phosphor, and 24 is a radiation of the radiation image conversion panel 23. A stimulated excitation light source for emitting a latent image as light emission, 25 is a photoelectric conversion device for detecting the stimulated light emission emitted from the radiation image conversion panel 23, and 26 is an image of the photoelectric conversion signal detected by the photoelectric conversion device 25. And 27 is a device for displaying the reproduced image, and 28 is a filter for cutting off the reflected light from the light source 24 and transmitting only the light emitted from the radiation image conversion panel 23. FIG. 3 shows an example of obtaining a radiation transmission image of a subject. However, when the subject 22 itself emits radiation, the radiation generator 21 is not particularly necessary. The photoelectric conversion device 25 and the subsequent devices are not limited to the above as long as they can reproduce optical information from the radiation image conversion panel 23 as an image in some form.

  As the stimulated excitation light source 24, a light source including the excitation wavelength of the stimulable phosphor used in the radiation image conversion panel 23 is used. In particular, when a laser beam is used, the optical system is simplified, and since the excitation light intensity can be increased, the photostimulative emission efficiency can be increased, and a more preferable result can be obtained.

Lasers include He—Ne laser, He—Cd laser, Ar ion laser, Kr ion laser, N ₂ laser, YAG laser and its second harmonic, ruby laser, semiconductor laser, various dye lasers, copper vapor laser, etc. There are metal vapor lasers. Normally, a continuous wave laser such as a He—Ne laser or an Ar ion laser is desirable, but a pulsed laser can also be used if the scanning time and pulse of one pixel of the panel are synchronized. Further, when using a method of separating light emission using a delay of light emission as shown in Japanese Patent Laid-Open No. 59-22046 without using the filter 28, a pulsed laser is used rather than modulation using a continuous wave laser. It is preferable to use it.

  Among the various laser light sources described above, the semiconductor laser is particularly preferably used because it is small and inexpensive and does not require a modulator.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to them.

Example 1
A phosphor plate having a vapor deposition type phosphor layer was produced according to the following method.

(Production of support)
Using titanium oxide (manufactured by Furuuchi Chemical Co., Ltd.) and zirconium oxide (manufactured by Furuuchi Chemical Co., Ltd.) on the surface of a transparent crystallized glass having a thickness of 500 μm, the reflectance at 400 nm is 85% and the reflectance at 660 nm is 20%. As described above, a film was formed using a vapor deposition apparatus to produce a glass support having a light reflection layer.

(Preparation of phosphor plate 11)
FIG. 4 is a schematic view of a vapor deposition apparatus. The said support body was installed in the vacuum chamber of the vapor deposition apparatus shown in FIG. 4, and it heated at 120 degreeC using the heating lamp (not shown). Thereafter, while evacuating using a vacuum pump, nitrogen gas is introduced from a gas introduction part at a flow rate of 1000 sccm through a pressure-regulating gas flow rate control device (not shown), and the degree of vacuum is 1.33 Pa. On the surface of the substrate, an alkali halide phosphor made of CsBr: 0.0001Eu is used from the normal direction of the support surface, using an aluminum slit, the distance between the support and the evaporation source is 60 cm, and the direction parallel to the support Then, vapor deposition was carried out while conveying the support to form a phosphor layer having a columnar crystal structure with a thickness of 400 μm, and a phosphor plate 11 was produced.

(Preparation of phosphor plates 12-18)
Phosphor plates 12 to 18 were produced in the same manner as the phosphor plate 11 except that the degree of vacuum and the nitrogen gas flow rate for pressure adjustment were changed as shown in Table 1.

  The adhesion between the phosphor layer of each obtained phosphor plate and the support glass was evaluated by the following method.

(Adhesive evaluation)
Adhesive tape was attached to the phosphor layer coating surface of each of the phosphor plates 11 to 18 produced above, and the area% of the phosphor layer adhering to the support when the tape was peeled off was measured. Adhesion was evaluated. The evaluation results are shown in Table 1.

5: The area where the phosphor layer adheres to the support is 100%
4: The area where the phosphor layer adheres to the support is 80% or more and less than 100% 3: The area where the phosphor layer adheres to the support 60% or more and less than 80% 2: The area where the phosphor layer adheres to the support 40% or more and less than 60% 1: The area where the phosphor layer adheres to the support is 20% or more and less than 40% 0: The area where the phosphor layer adheres to the support is less than 20%

  From Table 1, it can be seen that the phosphor plate having the degree of vacuum and the gas flow for adjusting the degree of vacuum within the range of the present invention has good adhesion.

Example 2
According to the following method, a phosphor plate having a vapor deposition type phosphor layer and a radiation image conversion panel were produced.

(Production of support)
The same glass support as in Example 1 was produced.

(Preparation of phosphor plate 21)
The said support body was installed in the vacuum chamber of the vapor deposition apparatus shown in FIG. 4, and it heated at 240 degreeC using the heating lamp. Then, while exhausting from an exhaust device (not shown) using a vacuum pump, nitrogen gas is passed through a regulated gas flow rate control device (not shown) at a flow rate of 1 sccm from a regulated gas introduction device (not shown). The degree of vacuum is set to 0.133 Pa, and an alkali halide phosphor made of CsBr: 0.0001Eu is formed on one side of the support from the normal direction of the support surface using an aluminum slit. The distance between the evaporation source and the evaporation source was set to 60 cm, and vapor deposition was performed while transporting the support in a direction parallel to the support to form a phosphor layer having a columnar structure with a thickness of 400 μm, thereby producing a phosphor plate 21.

(Preparation of phosphor plates 22 and 23)
Phosphor plates 22 and 23 were produced in the same manner as the phosphor plate 21 except that the type of gas for adjusting the degree of vacuum was changed as shown in Table 2.

  The adhesion between the phosphor layer of the obtained phosphor plate and the support glass was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

(Preparation of radiation image conversion panels 21 to 23)
Radiation image conversion panels 21 to 23 were produced using the phosphor plates 21 to 23 produced as described above, respectively.

  The photostimulable phosphor deposited using a glass support (without a light reflection layer) used for the production of the phosphor plate as a glass protective layer and a spacer on a side edge of the produced phosphor plate. A protective layer made of glass was provided between the surface of the layer and the protective layer glass plate so that the air layer had a thickness of 100 μm as a low refractive index layer. The spacer is made of glass ceramics, and the glass support is used by adjusting the thickness so that the phosphor layer and the low refractive index layer (air layer) have a predetermined thickness between the glass support and the protective layer glass. The side edges of the body and the protective layer made of glass were bonded using an epoxy adhesive to prepare each radiation image conversion panel.

  The sensitivity of the prepared radiation image conversion panel was evaluated as follows. Table 3 shows the evaluation results.

(Evaluation of sensitivity)
For each radiation image conversion panel, X-rays with a tube voltage of 80 kVp were irradiated from the back side of the phosphor plate support, and then the panel was excited by operating with He-Ne laser light (633 nm) and emitted from the phosphor layer. The received light is received by a light receiver (photoelectron image multiplier with spectral sensitivity S-5), the intensity is measured, this is defined as sensitivity, and the sensitivity of the radiation image conversion panel 23 is 1.00. Displayed by value.

DESCRIPTION OF SYMBOLS 10 Support body 11 Stimulable phosphor layer 12 Gap formed between columnar crystals 21 Radiation generator 22 Subject 23 Radiation image conversion panel 24 Stimulation excitation light source 25 Photoelectric conversion device 26 Image reproducing device 27 Image display device 28 Filter

Claims (13)

In a method for producing a radiation image conversion panel having a phosphor plate and a protective layer produced by forming a phosphor layer having a thickness of 50 μm or more on a support by vapor deposition, the phosphor layer comprises a matrix and an activator. Formed by vapor deposition, while evacuating using a vacuum pump, pressure-regulating gas is introduced from the gas introduction part via the pressure-regulating gas flow rate regulating device, and the degree of vacuum in the vapor deposition device is 1.33 × 10 ⁻² to 1.33 Pa, the flow rate of the pressure adjusting gas is 0.001 to 1000 sccm (sccm: standard cc / min (1 × 10 ⁻⁶ m ³ / min)), and the phosphor contained in the phosphor layer is a columnar crystal. And a low-refractive index layer is provided between the surface of the phosphor layer and the protective layer.   The method for producing a radiation image conversion panel according to claim 1, wherein a low refractive index layer is provided on a side edge of the phosphor plate via a spacer.   The side edge part of the said support body and protective layer is adhere | attached using the adhesive agent, The manufacturing method of the radiographic image conversion panel of Claim 1 or 2 characterized by the above-mentioned.   The method for producing a radiation image conversion panel according to any one of claims 1 to 3, wherein the pressure adjusting gas is nitrogen or argon. The method for manufacturing a radiation image conversion panel according to claim 1, wherein the phosphor layer contains a phosphor represented by the following general formula (1).
General formula (1)
M ¹ X · aM ² X ′ ₂ · bM ³ X ″ ₃ : eA
[Wherein M ¹ is at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs, and M ² is Be, Mg, Ca, Sr, Ba, Zn, Cd, Cu and At least one divalent metal selected from the group consisting of Ni, and M ³ is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga and In are at least one trivalent metal selected from the group consisting of In, and X, X ′ and X ″ are at least one selected from the group consisting of F, Cl, Br and I, respectively. A is a group consisting of Eu, Tb, In, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na, Ag, Cu and Mg At least one metal selected from , A, b, e each represent a number between 0 ≦ a <0.5,0 ≦ b <0.5,0 <e ≦ 0.2.] Method for producing a radiation image conversion panel according to claim 5, characterized in that M ¹ in the general formula (1) is at least one alkali metal selected from the group consisting of K, Rb and Cs.   The method for producing a radiation image conversion panel according to claim 5 or 6, wherein X in the general formula (1) is at least one halogen selected from Br and I. The radiation according to any one of claims 5 to 7, wherein M ² in the general formula (1) is at least one divalent metal selected from Be, Mg, Ca, Sr and Ba. Manufacturing method of image conversion panel. M ³ in the general formula (1) is at least one trivalent metal selected from the group consisting of Y, Ce, Sm, Eu, Al, La, Gd, Lu, Ga, and In. Item 9. The method for producing a radiation image conversion panel according to any one of Items 5 to 8. B in the said General formula (1) is 0 <= b <= 10 < ^-2 >, The manufacturing method of the radiographic image conversion panel of any one of Claims 5-9 characterized by the above-mentioned.   The A in the general formula (1) is at least one metal selected from the group consisting of Eu, Ce, Sm, Tl, and Na. Manufacturing method of radiation image conversion panel. 12. The method for producing a radiation image conversion panel according to claim 11, wherein the columnar crystal contains a phosphor represented by the following general formula (2).
General formula (2)
CsX: yA
[Wherein, X represents Br or I, and A represents Eu, In, Tb or Ce. y represents a numerical value from 1 × 10 ⁻⁷ to 1 × 10 ⁻² . ]   It manufactures with the manufacturing method of the radiographic image conversion panel of any one of Claims 1-12, The radiographic image conversion panel characterized by the above-mentioned.

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