JP2002022896A - Method for manufacturing radiation image conversion panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a radiation image conversion panel which is highly sensitive and gives radiation images of high picture quality. SOLUTION: The method for manufacturing a radiation image conversion panel that includes a process where a stimulable phosphor layer is formed by evaporating onto a support a substance produced through the irradiation of an evaporation source containing stimulable phosphors (or a material for them) with an electron beam is characterized by the use of the stimulable phosphors or the material of them whose relative density is 80% to 98% as the material for the evaporation source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a radiation image conversion panel used in a radiation image recording / reproducing method utilizing the stimulable light emission of a stimulable phosphor.

[0002]

2. Description of the Related Art A radiation image recording / reproducing method using a stimulable phosphor is known as an alternative to the conventional radiographic method. This method uses a radiation image conversion panel (a stimulable phosphor sheet) containing a stimulable phosphor, and transmits radiation transmitted through a subject or emitted from a subject to the stimulable phosphor of the panel. The radiation energy stored in the stimulable phosphor is absorbed by the body in a time-series manner by exciting the stimulable phosphor with electromagnetic waves (excitation light) such as visible light and infrared rays. The fluorescent light is emitted as (stimulated emission light), the fluorescence is read photoelectrically to obtain an electric signal, and a radiation image of a subject or a subject is reproduced as a visible image based on the obtained electric signal. After the reading, the panel is prepared for the next photographing after the remaining image is erased. That is, the radiation image conversion panel is used repeatedly.

According to this radiographic image recording / reproducing method, a radiographic image having a large amount of information can be obtained with a much smaller exposure dose than the conventional radiographic method using a combination of a radiographic film and an intensifying screen. There is an advantage that can be. Furthermore, in contrast to the conventional radiographic method, which consumes a radiographic film for each photographing operation, the radiographic image recording / reproducing method uses a radiographic image conversion panel repeatedly, so that resource conservation and economic efficiency are reduced. Is also advantageous.

The radiation image conversion panel used in the radiation image recording / reproducing method has, as a basic structure, a support and a stimulable phosphor layer provided thereon. However, when the stimulable phosphor layer is self-supporting, a support is not necessarily required. In addition, a protective film is usually provided on the upper surface of the stimulable phosphor layer (the surface not facing the support) to protect the phosphor layer from chemical deterioration or physical impact. ing.

The stimulable phosphor layer usually comprises a stimulable phosphor and a binder containing and supporting the stimulable phosphor in a dispersed state. However, there is also known a stimulable phosphor layer which does not include a binder formed by a vapor deposition method or a sintering method and is composed of only an aggregate of the stimulable phosphor. Further, there is known a radiation image conversion panel having a stimulable phosphor layer in which a polymer substance is impregnated in a gap between stimulable phosphor aggregates. In any of these phosphor layers, the stimulable phosphor is X
When irradiated with excitation light after absorbing radiation such as radiation, it has the property of stimulating luminescence, so radiation transmitted through a subject or emitted from a subject is proportional to the amount of radiation. Absorbed by the stimulable phosphor layer of the image conversion panel, a radiation image of the subject or the subject is formed on the panel as an accumulated image of radiation energy. This accumulated image can be emitted as stimulated emission light by irradiating the excitation light, and the accumulated image of radiation energy is imaged by photoelectrically reading the stimulated emission light and converting it into an electric signal. Can be realized.

As another method of the above-mentioned radiation image recording / reproducing method, Japanese Patent Application No. 11-372978 by the present applicant discloses a stimulable phosphor-containing stimulable phosphor layer (and a radiation-absorbing phosphor layer). A radiation image forming method using a combination of a radiation image conversion panel having a body layer) and a phosphor screen having a radiation absorbing phosphor layer containing a phosphor that absorbs radiation and emits light in the ultraviolet to visible region, and Radiation imaging materials comprising combinations thereof are described. In this method, radiation transmitted through a subject, diffracted or scattered by the subject, or emitted from the subject is first applied to a fluorescent screen or a radiation absorbing phosphor layer of a radiation image conversion panel in an ultraviolet to visible region. After that, the light is accumulated and recorded as a latent image in the stimulable phosphor layer of the panel. Next, the panel is irradiated with excitation light to photoelectrically read the stimulated emission light from the stimulable phosphor layer to convert it into an image signal, and reconstruct an image corresponding to the spatial energy distribution of radiation from the image signal. Make up. The radiation image conversion panel of the present invention includes an image forming material used in the above method, that is, a panel containing both a stimulable phosphor and a phosphor that absorbs radiation and emits light in the ultraviolet to visible region. , A fluorescent screen is also included.

The radiation image recording / reproducing method (and the radiation image forming method) has many excellent advantages as described above, but the radiation image conversion panel used in this method has as high a sensitivity as possible. It is desired to provide an image with good image quality (sharpness, granularity, etc.).

For the purpose of improving sensitivity and image quality, as described in, for example, Japanese Patent Application Laid-Open No. 62-47600, as a method for manufacturing a radiation image conversion panel, a stimulable phosphor layer is formed by a vapor deposition method. A method of forming by an electron beam evaporation method, which is one of the methods, has been proposed. This method uses a stimulable phosphor or a raw material of a stimulable phosphor as an evaporation source, and irradiates an electron beam with an electron gun to the evaporation source to evaporate the evaporation source.
The phosphor layer is made of columnar crystals of a stimulable phosphor by scattering and depositing the evaporated substance on the surface of a support such as a metal sheet.

The phosphor layer formed by a vapor deposition method such as an electron beam evaporation method does not contain a binder and is composed of only a stimulable phosphor. Voids (cracks) exist between them. For this reason, an image with high sensitivity and high sharpness can be obtained. Also, in the electron beam evaporation method, since the evaporation source is locally heated and evaporated instantaneously, a substance having a high vapor pressure in the evaporation source is preferentially evaporated as in the case of the evaporation by the resistance heating method. (For example, the activator evaporates before the phosphor matrix), and the composition of the phosphor charged as the evaporation source and the composition of the phosphor in the formed phosphor layer hardly match. .

[0010] Japanese Patent Application Laid-Open No. Sho 62-47600 discloses that
It describes that a stimulable phosphor or a raw material thereof (specifically, RbBr: Tl stimulable phosphor is used as an evaporation source) is formed into a crucible or the like by a press such as a hot press as an evaporation source. However, there is no description about the pressure at the time of pressing or the density of the molded product. In addition, Japanese Patent Publication 5-171
No. 70 discloses a method for producing a zinc sulfide-based thin film used for an antireflection film of a lens, an electroluminescence (EL) element, and the like. When a sintered body having a high density and a large particle diameter is used as an evaporation source, It describes that a uniform and high quality thin film containing no fine particles or pinholes can be produced.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a radiation image conversion panel in which the columnar crystals of the phosphor have a good shape and are arranged in a well-arranged manner. Another object of the present invention is to provide a method for manufacturing a radiation image conversion panel that provides high-sensitivity, high-quality radiation images.

[0012]

The inventors of the present invention have studied a method of forming a phosphor layer of a radiation image conversion panel by an electron beam evaporation method. As a result, a phosphor having a relative density of not less than a certain value or its phosphor is used as an evaporation source. It has been found that a phosphor layer in which columnar crystals of the phosphor are aligned can be formed by using a raw material, particularly by using a tablet having a relative density of not less than a certain value by pressurizing and compression.

Accordingly, the present invention forms a stimulable phosphor layer by depositing a substance generated by irradiating an electron beam on a stimulable phosphor or an evaporation source containing the material on a support. In a method for manufacturing a radiation image conversion panel including a step, a radiation image wherein a relative density of a stimulable phosphor or a raw material thereof is 80% or more and 98% or less is used as the evaporation source. In a method of manufacturing a conversion panel. In the present invention, the relative density means a ratio of the actual density of the evaporation source to the density specific to the phosphor or its raw material.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the method of the present invention, the relative density of the evaporation source is preferably 90% or more, and particularly preferably 96% or less. It is preferable to produce a tablet-shaped evaporation source by compressing the phosphor or its raw material under pressure. The electron beam has an acceleration voltage of 1.5 kV or more and preferably 5.0 kV or less. Further, it is preferable to use an alkali metal halide-based stimulable phosphor having the following basic composition formula (I) or its raw material as an evaporation source. In the following basic composition formula (I), M ^I
Comprises at least Cs, X comprises at least Br,
A is particularly preferably Eu or Bi.

[0015] ^{M I X · aM II X '} 2 · bM III X "3: zA ‥‥ (I) ( provided that, M ^I is Li, Na, K, of at least one alkali selected from the group consisting of Rb and Cs Represents a metal; M ^II is Be, Mg, Ca, Sr, Ba, Ni, C
u, represents at least one alkaline earth element or trivalent metal selected from the group consisting of Zn and Cd; M ^III is S
c, Y, La, Ce, Pr, Nd, Pm, Sm, Eu,
Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, A
represents at least one rare earth element or trivalent metal selected from the group consisting of 1, Ga and In; X, X ′ and X ″
Each represents at least one halogen selected from the group consisting of F, Cl, Br and I; A represents Y, Ce,
Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, E
r, Tm, Yb, Lu, Na, Mg, Cu, Ag, Tl
And at least one rare earth element or metal selected from the group consisting of Bi and Bi; and a, b and z are respectively 0 ≦ a <0.5, 0 ≦ b <0.5, and 0 ≦ z <0.2.
Represents a number within the range of

Hereinafter, the method for producing the radiation image storage panel of the present invention will be described in detail by taking as an example a case where a phosphor layer made of a stimulable phosphor is formed. The support can be arbitrarily selected from materials known as a support for a conventional radiation image conversion panel, and a particularly preferred support material is a quartz glass sheet; a metal sheet made of aluminum, iron, tin, chromium, or the like; It is a resin sheet made of aramid or the like. In a known radiation image conversion panel, in order to improve the sensitivity or the image quality (sharpness, granularity) of the radiation image conversion panel, a light reflection layer made of a light reflection material such as titanium dioxide, or a light such as carbon black. It is known to provide a light absorbing layer or the like made of an absorbing substance. The support used in the present invention can also be provided with these various layers, and the configuration thereof can be arbitrarily selected depending on the desired purpose and application of the radiation image storage panel. Further, JP-A-58-2002
As described in Japanese Patent Application Publication No. 00-2000, in order to improve the sharpness of the obtained image, the surface of the support on the phosphor layer side (the undercoat layer (adhesiveness (Layers), an auxiliary layer such as a light reflecting layer or a light absorbing layer may be provided on the surface of the auxiliary layer).

A phosphor layer is provided on the support by electron beam evaporation. As a stimulable phosphor, the wavelength is 4
Irradiation of excitation light in the range of 00 to 900 nm results in 300
A stimulable phosphor that emits stimulable light in the wavelength range of from 500 nm to 500 nm is preferred. An example of such a stimulable phosphor is described in
No. 84588, JP-A-2-193100 and JP-A-4-310900.

[0018] Among these, the basic formula ^{(I): M I X ·} aM II X '2 · bM III X "3: zA ‥‥ alkali metal halide stimulable phosphor represented by (I) Is particularly preferred, provided that M ^I is Li, Na, K, Rb
And represents at least one alkali metal selected from the group consisting of Cs, M ^II is Be, Mg, Ca, Sr, B
a, at least one kind of alkaline earth metal or divalent metal selected from the group consisting of Ni, Cu, Zn and Cd, and M ^III is Sc, Y, La, Ce, Pr, Nd, P
m, Sm, Eu, Gd, Tb, Dy, Ho, Er, T
m represents at least one rare earth element or trivalent metal selected from the group consisting of Lu, Al, Ga and In, and A represents Y, Ce, Pr, Nd, Sm, Eu, G
d, Tb, Dy, Ho, Er, Tm, Yb, Lu, N
a, at least one rare earth element or metal selected from the group consisting of Mg, Cu, Ag, Tl and Bi.
X, X ′ and X ″ are F, Cl, Br and I, respectively.
Represents at least one halogen selected from the group consisting of a, b and z are respectively 0 ≦ a <0.5, 0 ≦
b <0.5, 0 ≦ z <0.2.

It is preferable that M ^I in the basic composition formula (I) contains at least Cs. It is preferable that X contains at least Br. A is particularly preferably Eu or Bi. In addition, the basic composition formula (I) includes, if necessary, aluminum oxide,
A metal oxide such as silicon dioxide or zirconium oxide may be added as an additive in an amount of 0.5 mol or less based on 1 mol of M ^I.

First, the above-described stimulable phosphor is compressed under pressure as an evaporation source to produce tablets (pellets). The compression pressure varies depending on the type and state of the phosphor, but is generally in the range of 800 to 1000 kg / cm ² . During the compression, the mixture may be heated to a temperature in the range of 50 to 200C. After pressurizing and compressing, the obtained tablets are preferably subjected to a degassing treatment. Thereby, the relative density is 80% or more,
98% or less tablets can be obtained. Preferably, the relative density of the tablet is 90% or more. Reduce to 96% or less. If the relative density of the evaporation source is low, the phosphor does not evaporate uniformly from the tablet surface, resulting in an uneven thickness of the deposited film, or the adhesion between the deposited film and the support because bumping substances adhere to the support. The properties and surface properties of the vapor-deposited film are deteriorated, and the phosphor itself is non-uniformly evaporated, and the activator and additive of the phosphor are segregated in the vapor-deposited film. In the present invention, the evaporation source does not necessarily need to be in the form of a tablet, but may have a relative density in the above range. It is also possible to use a raw material or a raw material mixture instead of the stimulable phosphor.

Next, a stimulable phosphor tablet as an evaporation source and a support as an object to be deposited are placed in a deposition apparatus, and the apparatus is evacuated to 3 × 10 ^{-10 to} 3 × 10 ^-12. kg /
The degree of vacuum is about cm ² . At this time, an inert gas such as an Ar gas or a Ne gas may be introduced while maintaining the degree of vacuum at this level.

Next, an electron beam is generated from the electron gun and irradiated to the evaporation source. At this time, the electron beam acceleration voltage is set to 1.5
It is desirable to set the voltage to not less than kV and not more than 5.0 kV. If the acceleration voltage is lower than 1.5 kV, the voltage becomes unstable, the beam position of the electron beam fluctuates, or the shape of the scanning surface by the electron beam of the evaporation source changes to keep the evaporation surface flat. It becomes difficult. When the accelerating voltage is further reduced, the maximum current value gradually decreases (power decreases), and no electron beam is generated at 0.5 kV or less.
Conversely, when the accelerating voltage is higher than 5.0 kV, the columnar crystals of the phosphor that grows in a vapor phase by evaporation become uneven, and as a result, the spread of the excitation light at the time of reading a radiation image causes sharpness and the like. Causes the image quality to deteriorate. 10 more
Above kV, the phosphor as the evaporation source evaporates rapidly, making it impossible to control its vapor phase growth. Preferably, the acceleration voltage of the electron beam is 2.0 kV or more and 4.0 kV.
Set to kV or less.

The irradiation of the electron beam causes the stimulable phosphor, which is the evaporation source, to be heated, evaporated, scattered, and deposited on the surface of the support. The deposition rate of the phosphor, that is, the deposition rate, is generally in the range of 0.1 to 1000 μm / min, preferably in the range of 1 to 100 μm / min. The irradiation of the electron beam may be performed a plurality of times to form two or more phosphor layers, or different phosphors may be co-evaporated using a plurality of electron guns. Further, it is also possible to synthesize a phosphor on a support by using a phosphor raw material and simultaneously form a phosphor layer. Furthermore, the object to be deposited (support) may be cooled or heated as necessary during the vapor deposition, or the phosphor layer is subjected to a heat treatment (annealing treatment) after the vapor deposition is completed.
May be.

In this manner, a phosphor layer in which the columnar crystals of the stimulable phosphor are grown almost in the thickness direction as shown in FIG. 1 is obtained. FIG. 1 is a cross-sectional photograph of the phosphor layer according to the present invention. The phosphor layer is composed of only the stimulable phosphor, and a void (crack) is formed between the columnar crystals of the stimulable phosphor.
Exists. According to the method of the present invention, since the evaporation source can be uniformly evaporated and the columnar crystals can be formed in a good shape and aligned, the efficiency of entering the excitation light and the efficiency of extracting the emission light can be improved. At the same time, the excitation light can be prevented from scattering in the plane direction, and the sharpness can be increased. In addition, it is possible to obtain a uniform phosphor layer with little surface irregularities and good adhesion to the support. Furthermore, according to the present invention, since the filling rate of the phosphor can be further increased, a radiation image with excellent granularity can be obtained. The thickness of the phosphor layer is usually from 100 μm to 1 μm.
mm, preferably 200 μm to 700 mm
In the range.

It is desirable to provide a protective film on the surface of the phosphor layer in order to facilitate transportation and handling of the radiation image conversion panel and to avoid a change in characteristics.

The protective film is desirably transparent so that it hardly affects the incidence of excitation light and the emission of stimulated emission light. It is desirable that the panel be chemically stable, highly moisture-proof, and have high physical strength so that the panel can be sufficiently protected. As a protective film, a solution prepared by dissolving a transparent organic polymer substance such as a cellulose derivative, polymethyl methacrylate, or an organic solvent-soluble fluororesin in an appropriate solvent is applied onto the stimulable phosphor layer. Or an organic polymer film such as polyethylene terephthalate or a protective film forming sheet such as a transparent glass plate separately formed and provided on the surface of the phosphor layer using an appropriate adhesive Alternatively, an inorganic compound formed on the phosphor layer by vapor deposition or the like is used. Various additives such as light-scattering fine particles such as magnesium oxide, zinc oxide, titanium dioxide, and alumina, slip agents such as perfluoroolefin resin powder and silicone resin powder, and crosslinking agents such as polyisocyanate are contained in the protective film. May be dispersedly contained. The thickness of the protective film is generally in the range of about 0.1 to 20 μm.

Further, a fluororesin coating layer may be provided on the surface of the protective film in order to enhance the contamination resistance of the protective film. The fluororesin coating layer can be formed by applying a fluororesin solution prepared by dissolving (or dispersing) a fluororesin in an organic solvent on the surface of the protective film and drying.
The fluororesin may be used alone, but is usually used as a mixture of the fluororesin and a resin having a high film forming property. Further, an oligomer having a polysiloxane skeleton or an oligomer having a perfluoroalkyl group can be used in combination. The fluororesin coating layer may be filled with a particulate filler in order to reduce interference unevenness and further improve the quality of a radiographic image. The thickness of the fluororesin coating layer is usually in the range of 0.5 μm to 20 μm. In forming the fluororesin coating layer, additional components such as a crosslinking agent, a hardening agent, an anti-yellowing agent and the like can be used. In particular, the addition of a crosslinking agent is advantageous for improving the durability of the fluororesin coating layer.

As described above, the radiation image storage panel of the present invention is obtained. The configuration of the panel of the present invention may include various known variations. For example, for the purpose of improving the sharpness of the obtained image, at least one of the above-mentioned layers may be colored with a coloring agent that absorbs excitation light but does not absorb stimulating light (Japanese Patent Publication No. No. 59-23400).

[0029]

[Example 1] (1) Preparation of evaporation source 100 g of cesium bromide (CsBr, 0.47 mol) and 31.8404 g of europium bromide (EuBr, 4.7 ×)
10 ⁻³ mol) in a mortar, and then mixed by stirring with a stirring vibrator for 15 minutes. The resulting mixture was placed in a furnace, evacuated for 3 minutes, and then heated to 525 ° C. in a nitrogen atmosphere.
For 2 hours. After firing, the furnace was evacuated for 15 minutes to cool the fired product. Then, the obtained europium-activated cesium bromide (CsBr: 0.01 Eu) stimulable phosphor was pulverized in a mortar, and then pressurized and compressed at a pressure of 800 kg / cm ² to prepare a tablet for vapor deposition. Tablets with an additional temperature of 15
Evacuation was performed at 0 ° C. for 2 hours to perform a degassing treatment. The density of the obtained tablet was 3.6 g / cm ³ , and the relative density obtained by dividing the density by the density of the phosphor was 81%.

(2) Formation of Phosphor Layer An aluminum sheet was placed in a vapor deposition device as a support. After placing the above-mentioned vapor deposition source at a predetermined position in the apparatus, the inside of the apparatus was evacuated to a degree of vacuum of 4.0 × 10 ⁻⁹ kg / cm ² . Next, an electron gun was irradiated with an electron beam having an acceleration voltage of 4.0 kV for 20 minutes with an electron gun to deposit a stimulable phosphor on the aluminum sheet at a rate of 25 μm / min. afterwards,
The irradiation of the electron beam was stopped, the inside of the apparatus was returned to the atmospheric pressure, and the aluminum sheet was taken out of the apparatus. On the aluminum sheet support, a phosphor layer (layer thickness: 450 μm) having a structure in which columnar crystals of the phosphor having a width of about 3 μm and a length of about 450 μm were densely arranged almost vertically in a vertical direction was formed. In this way, a radiation image conversion panel comprising the support and the stimulable phosphor layer was manufactured.

Example 2 A radiation image storage panel of the present invention was manufactured in the same manner as in Example 1 except that the pressure during pressurization and compression was changed to 900 kg / cm ² . The density of the obtained tablet was 4.0 g / cm ³ , and the relative density was 90%.

Example 3 A radiation image storage panel of the present invention was manufactured in the same manner as in Example 1, except that the pressure during pressurization and compression was changed to 950 kg / cm ² . The density of the obtained tablet was 4.2 g / cm ³ , and the relative density was 95%. Further, when a photograph of a cross section of the phosphor layer was taken with an electron microscope, a photograph shown in FIG. 1 was obtained.

[Comparative Example 1] A comparative example was performed in the same manner as in Example 1 except that the stimulable phosphor was not pressed and compressed, and a powdered phosphor was used as an evaporation source. A radiation image conversion panel was manufactured.

Comparative Example 2 A radiation image conversion panel for comparison was manufactured in the same manner as in Example 1 except that the pressure during pressurization and compression was changed to 700 kg / cm ² . The density of the obtained tablet is 3.0 g / cm ³ ,
The relative density was 68%.

[Evaluation of Performance of Radiation Image Conversion Panel] Each of the obtained radiation image conversion panels was subjected to an individual shape of phosphor columnar crystals, overall condition, surface properties of the phosphor layer, and adhesion to the support. Was evaluated.

(1) Individual shape of columnar crystals: The presence or absence of crystal nodes and the degree of adhesion between columnar crystals were determined by electron micrograph. (2) State of the whole columnar crystal: The degree of the crystal growing in the same direction at a certain angle in the vertical direction of the support, that is, the degree of uniformity of the crystal was determined by an electron micrograph. (3) Surface property of phosphor layer (deposited film): The surface roughness of the deposited film was visually determined. The surface properties depend on crystal defects, poor anisotropy, and scattered matter (bumps) from the evaporation source, in addition to the difference in growth rate in the plane direction of the crystal. (4) Adhesion to the support: Judgment was made based on the ease with which the phosphor layer was peeled from the support. All were evaluated according to the following criteria. AA: extremely good, A: good, B: slightly bad, C: bad and practically problematic. The results obtained are summarized in Table 1.

[0037]

[Table 1] Table 1 {Shape of columnar crystal phosphor layer State Surface property Adhesive property} ─────────────────────────────── Example 1 A A A A A Example 2 AA A A A Example 3 A A A A A 比較 Comparative Example 1 BBCB Comparative Example 2 BBBB ── ──────────────────────────────

As is evident from the results in Table 1, according to the method of the present invention, a radiation image conversion panel (Examples 1 to 3) produced using tablets having a relative density in the range of 80 to 95% as an evaporation source. In each case, the shape and arrangement of the columnar crystals of the stimulable phosphor were excellent, and the surface properties of the phosphor layer and the adhesion to the support were also good. In particular, Example 1 using a tablet having a relative density in the range of 90 to 95%
In Examples 2 and 3, the shape of the columnar crystals was extremely good.

On the other hand, in Comparative Example 1 in which a faint powder which was not compressed under pressure was used as an evaporation source, and in Comparative Example 2 in which a tablet having a low relative density was compressed and compressed, the shape and state of columnar crystals were changed. Both the surface properties and the adhesiveness of the phosphor layer were insufficient.

[0040]

According to the present invention, when the phosphor layer is formed by the electron beam evaporation method, the relative density of the evaporation source is set to 80% or more and 98% or less, whereby the columnar crystal of the phosphor is formed. It is possible to stably form a phosphor layer which is extremely good in shape and arrangement state, homogeneous, and has good surface properties and good adhesion to a support. Therefore, the radiation image conversion panel manufactured according to the method of the present invention can provide a radiation image with high sensitivity and excellent image quality such as sharpness and granularity.

[Brief description of the drawings]

FIG. 1 is a micrograph showing an example of a cross section of a phosphor layer formed according to the method of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C09K 11/62 CQD C09K 11/62 CQD 11/64 CPE 11/64 CPE CQD CQD 11/85 CPE 11/85 CPE CQD CQD F term (reference) 2G083 AA03 BB01 CC03 CC04 DD02 DD11 DD12 EE02 EE03 EE07 EE10 4H001 CA04 XA00 XA13 XA21 XA31 XA35 XA39 XA49 XA55 XB11 XB71 YA00 YA11 YA12 YA29 YA29 YA29

Claims (6)

[Claims] 1. A radiation comprising a step of forming a stimulable phosphor layer by depositing a substance generated by irradiating an electron beam on a stimulable phosphor or an evaporation source containing a raw material thereof on a support. In a method for manufacturing an image conversion panel,
A method for producing a radiation image conversion panel, wherein an evaporation source having a relative density of a stimulable phosphor or a raw material of 80% or more and 98% or less is used as the evaporation source. 2. When the relative density of the evaporation source is 90% or more,
%. The method for producing a radiation image storage panel according to claim 1, wherein 3. The evaporation source according to claim 1, wherein the stimulable phosphor or a raw material thereof is compressed and compressed into a tablet form.
Or the method for manufacturing a radiation image conversion panel according to 2. Wherein the evaporation source, the basic formula ^{(I): M I X ·} aM II X '2 · bM III X "3: zA ‥‥ (I) [ However, M ^I is Li, Na, K, M ^II represents at least one alkali metal selected from the group consisting of Rb and Cs; M ^II represents Be, Mg, Ca, Sr, Ba, Ni, C
u, represents at least one alkaline earth element or trivalent metal selected from the group consisting of Zn and Cd; M ^III is S
c, Y, La, Ce, Pr, Nd, Pm, Sm, Eu,
Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, A
represents at least one rare earth element or trivalent metal selected from the group consisting of 1, Ga and In; X, X ′ and X ″
Each represents at least one halogen selected from the group consisting of F, Cl, Br and I; A represents Y, Ce,
Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, E
r, Tm, Yb, Lu, Na, Mg, Cu, Ag, Tl
And at least one rare earth element or metal selected from the group consisting of Bi and Bi; and a, b and z are respectively 0 ≦ a <0.5, 0 ≦ b <0.5, and 0 ≦ z <0.2.
The method for producing a radiation image conversion panel according to any one of claims 1 to 3, which comprises an alkali metal halide-based stimulable phosphor having the following formula: M ^I 5. A basic composition formula (I) contains at least Cs, X contains at least Br, and A
5. The method of manufacturing a radiation image storage panel according to claim 4, wherein Eu is Bi or Bi. 6. Irradiation of an electron beam to an evaporation source is performed at 1.5 kV.
The method of manufacturing a radiation image conversion panel according to claim 1, wherein the method is performed at an acceleration voltage of 5.0 kV or less.