JP2001081457A - Formation of rare-earth-activated alkaline earth metal fluorohalide stimulable phosphor particle and radiation image conversion panel using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain particles for a radiation image conversion panel having a high clarity, a high luminance, and a high particle fineness by carrying out the surface treatment of fired phosphor particles with a silane coupling agent in the presence of metal oxide particles having a specified mean particle diameter by a wet process under high-speed agitation. SOLUTION: Synthesized stimulable phosphor particles are fired, 0.01-10 wt.%, based on the phosphor particles, metal oxide particles, such as of Al2O3 or SiO2, having a mean particle diameter of 2-50 nm and 0.1-5 wt.% silane coupling agent such as γ-mercaptopropyltrimethoxysilane are added to the fired particles, and the resulting mixture is wet-treated under high-speed agitation of at least 5/sec peripheral speed to obtain a rare-earth-activated alkaline earth metal fluorohalide stimulable phosphor represented by the formula: Ba1-XM2XFX: yM1.zLn and having a mean particle diameter of 1-10 μm. In the formula, M2 is Mg, Ca, Sr, or the like; M1 is Li, Na, K, Rb, or the like; X is Cl, Br, or I; Ln is Ce, Pr, Sm, Eu, or the like; 0<=x<=0.6; 0<=y<=0.05; and 0<z<=0.6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image conversion panel using a stimulable phosphor, and more particularly to a radiation image conversion panel which can be used in a good condition for a long time with little deterioration in performance due to moisture absorption. The present invention relates to a method for forming a stimulable phosphor, which provides a radiation image conversion panel having sharpness, luminance, and granularity, and a conversion panel using the same.

[0002]

2. Description of the Related Art Radiation images such as X-ray images are widely used for diagnosis of diseases. In order to obtain this X-ray image, the X-rays that have passed through the subject are applied to a phosphor layer (fluorescent screen)
Thus, a so-called radiograph is used, in which a visible light is generated by this, and this visible light is irradiated and developed on a film using a silver salt in the same manner as when a normal photograph is taken. However, in recent years, a method has been devised for directly taking out an image from the phosphor layer without using a film coated with a silver salt.

In this method, radiation transmitted through a subject is absorbed by a phosphor, and then the phosphor is excited by, for example, light or heat energy, so that the radiation energy accumulated by the phosphor is absorbed by the phosphor. Then, there is a method of detecting and imaging this fluorescence. Specifically, for example, US Pat. No. 3,859,527
And a radiation image conversion method using a stimulable phosphor as described in JP-A-55-12144 and the like.

In this method, a radiation image conversion panel containing a stimulable phosphor is used. Radiation transmitted through a subject is applied to the stimulable phosphor layer of the radiation image conversion panel to transmit radiation of each part of the subject. By accumulating radiation energy corresponding to the density, and subsequently exciting the stimulable phosphor with electromagnetic waves (excitation light) such as visible light and infrared light in a time series manner, the stimulable phosphor is accumulated in the stimulable phosphor. The emitted radiation energy is emitted as stimulated emission, and a signal based on the intensity of the light is photoelectrically converted, for example, to obtain an electric signal, and this signal is converted into a visible image on a recording material such as a photosensitive film or a display device such as a CRT. Is to be played as

According to the above-described radiographic image recording / reproducing method, a radiation having a large amount of information with a much smaller exposure dose than the radiographic method using a combination of a conventional radiographic film and an intensifying screen. There is an advantage that an image can be obtained.

As described above, the stimulable phosphor is a phosphor that emits stimulable light when irradiated with radiation and then with excitation light. However, in practice, excitation light having a wavelength in the range of 400 to 900 nm is used. In general, phosphors exhibiting stimulated emission in the wavelength range of 300 to 500 nm are used.

The following are examples of stimulable phosphors conventionally used in radiation image conversion panels. (1) (Ba _1-X , M ²⁺ _X ) FX: yA (provided that M ²⁺ is described in JP-A-55-12145)
Is at least one of Mg, Ca, Sr, Zn and Cd, X is at least one of Cl, Br and I, A is Eu, Tb, Ce, Tm, Dy, Pr, Ho,
At least one of Nd, Yb, and Er, and x is 0 ≦ x ≦ 0.6, and y is 0 ≦ y ≦ 0.2). Metal fluorinated metal halide phosphors; the phosphors may also contain the following additives:
X ', Be described in Japanese Patent No. 74175
X ″, M ³ X ″ ″ ₃ (where X ′, X ″, and X ′ ″ are each at least one of Cl, Br and I, and M ³ is a trivalent metal);

[0008] BeO, BgO, CaO, SrO, BaO, Z described in JP-A-55-160078
nO, Al ₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ , In
₂ O ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , GeO ₂ , S
Metal oxides such as nO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ and ThO ₂ ; Zr and Sc described in JP-A-56-116777; described in JP-A-57-23673. B; As, Si described in JP-A-57-23675;

ML described in JP-A-58-206678 (where M is Li, Na, K, Rb,
And L is Sc, Y, La, Ce, Pr, or at least one alkali metal selected from the group consisting of
Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, T
m, Yb, Lu, Al, Ga, In, and at least one trivalent metal selected from the group consisting of Tl);
A calcined product of a tetrafluoroborate compound described in JP-A-59-27980;
No. 9; a calcined product of a salt of a monovalent or divalent metal of hexafluorosilicic acid, hexafluorotitanic acid and hexafluorozirconic acid;
NaX 'described in JP-A-6479 (provided that
X ′ is at least one of Cl, Br and I); transition metals such as V, Cr, Mn, Fe, Co and Ni described in JP-A-59-56480;

[0010] JP-A-59-75200 describes
M¹X ', M'²X '', M ³X '' ', A (
But M¹Consists of Li, Na, K, Rb, and Cs
At least one alkali metal selected from the group consisting of
M '²Is a small number selected from the group consisting of Be and Mg
At least a divalent metal; M³Is Al, Ga, I
at least one selected from the group consisting of n and Tl
A is a metal oxide; X ',
X "and X" "represent F, Cl, Br and
At least one halogen selected from the group consisting of I
There); described in JP-A-60-101173.
M¹X '(where M¹Consists of Rb and Cs
At least one alkali metal selected from the group;
X 'is selected from the group consisting of F, Cl, Br and I
At least one halogen);

[0011] JP-A-61-23679 describes
M²'X'₂・ M²'X' ' ₂(However, M²′
Is at least one selected from the group consisting of Ba, Sr and Ca
X 'and X "are both alkaline earth metals;
Is selected from the group consisting of Cl, Br and I
At least one halogen and X ′ ≠ X ″
And Japanese Patent Application No. 60-106752.
LnX ″ described₃(However, Ln is Sc,
Y, La, Ce, Pr, Nd, Pm, Sm, Gd, T
b, Dy, Ho, Er, Tm, Yb and Lu
At least one rare earth element selected from the group;
X ″ is selected from the group consisting of F, Cl, Br and I
(2) described in JP-A-60-84381.
M²X₂・ AM²′₂: XEu²⁺(However, M²Is B
a, at least selected from the group consisting of Sr and Ca
X and X 'are Cl, a kind of alkaline earth metal;
At least one member selected from the group consisting of Br and I
Is halogen and X ≠ X ′; and a is
0.1 ≦ a ≦ 0.0, x is 0 <x ≦ 0.2)
Bivalent europium activated alkaline earth gold expressed by the formula
Genus halide phosphors;

Further, the following additives are added to the phosphor.
May be included; JP-A-60-166379
M listed in the report¹ X "(where M ¹Is Rb
And at least one member selected from the group consisting of
X '' is F, Cl, Br and I
At least one halogen selected from the group consisting of
Described in JP-A-60-221483.
KX ", MgX" "₂, M³ X '' '' '₃(T
But M³Consists of Sc, Y, La, Gd and Lu
At least one trivalent metal selected from the group;
X ", X" "and X" "" are all F, C
at least one selected from the group consisting of l, Br and I
Kind of halogen); JP-A-60-228592
B described in the report: JP-A-60-228593
SiO described in the report₂, P₂O₅Oxides, etc .;
Li described in JP-A-61-120882
X ", NaX" (where X "is F, Cl, Br
At least one halo selected from the group consisting of
Described in JP-A-61-120883.
SiO: disclosed in JP-A-61-120885
The SnX ″ described₂(However, X ″ is F, C
at least one selected from the group consisting of l, Br and I
Species halogen);

[0013] Japanese Patent Application Laid-Open No. 61-235486 describes
CsX '', SnX '' '' ₂(However, X ''
And X ′ ″ are from F, Cl, Br and I, respectively.
At least one halogen selected from the group consisting of
); And JP-A-61-235487.
CsX '', Ln³⁺(However, X ″ is F,
At least selected from the group consisting of Cl, Br and I
Ln is Sc, Y, Ce, Pr,
Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Y
at least one member selected from the group consisting of b and Lu
A rare earth element);

(3) LnOX: xA described in JP-A-55-12144 (where Ln is La,
At least one of Y, Gd, and Lu; X is C
at least one of l, Br, and I; A is at least one of Ce and Tb; and x is 0 <x
<0.1), a rare earth element activated rare earth oxyhalide phosphor represented by a composition formula:

(4) M ³ OX: xCe described in JP-A-58-69281 (where M ³ is Pr,
Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, T
at least one metal oxide selected from the group consisting of m, Yb, and Bi; X is at least one of Cl, Br, and I; and x is 0 <x <0.1). A cerium-activated trivalent metal oxyhalide phosphor represented by the formula:

(5) M ¹ X: xBi described in the specification of Japanese Patent Application No. 60-70484, wherein M ¹ is at least one alkali metal selected from the group consisting of Rb and Cs; At least one halogen selected from the group consisting of Cl, Br and I; and x
Is a numerical value in the range of 0 <x ≦ 0.2) bismuth-activated alkali metal halide phosphor represented by a composition formula;

[0017] ^{_{(6) M 2 5 (PO}} 4) as described in JP 60-141783 discloses 3 x: at least one ^{xEu 2+} (However, ^{M 2} is selected from the group consisting of Ca, Sr and Ba X is at least one halogen selected from the group consisting of F, Cl, Br and I; and x is a numerical value in the range of 0 <x ≦ 0.2). A divalent europium activated alkaline earth metal halophosphate phosphor represented by:

[0018] (7) ^M _{2 2 BO} 3 that is described in JP 60-157099 discloses X: ^{xEu 2+} (where
M ² is at least one alkaline earth metal selected from the group consisting of Ca, Sr and Ba; X is Cl, B
at least one halogen selected from the group consisting of r and I; x is a numerical value in the range of 0 <x ≦ 0.2) divalent europium-activated alkaline earth metal haloborate represented by the composition formula: Phosphor;

[0019] (8) ^M _{2 2 PO} 4 as described in JP 60-157100 discloses X: ^{xEu 2+} (where
M ² is at least one alkaline earth metal selected from the group consisting of Ca, Sr and Ba; X is Cl, B
at least one halogen selected from the group consisting of r and I; x is a numerical value in the range of 0 <x ≦ 0.2) divalent europium-activated alkaline earth metal halophosphate represented by a composition formula: Phosphor;

(9) M ² HX: xEu ²⁺ described in JP-A-60-217354 (where M ² is at least one kind of alkaline earth metal selected from the group consisting of Ca, Sr and Ba) X is at least one halogen selected from the group consisting of Cl, Br and I; x is a numerical value in the range of 0 <x ≦ 0.2) Earth metal hydride halide phosphors;

[0021] (10) _LnX as described in JP 61-21173 discloses 3 _· aLn'X '3: ^{xCe 3+}
(However, Ln and Ln ′ are Y, La, and Gd, respectively.
X and X ′ are F, Cl, B, respectively, at least one rare earth element selected from the group consisting of
at least one halogen selected from the group consisting of r and I, and X ≠ X ′;
It is a numerical value in the range of 1 <a ≦ 10.0, and x is 0 <x ≦
A cerium-activated rare earth composite halide phosphor represented by a composition formula:

[0022] (11) JP-61-21182 JP _LnX 3 ^· aM 1 that is described in X ': ^{xCe 3+} (However, Ln and Ln', respectively Y, La, selected from the group consisting of Gd and Lu Is at least one rare earth element; M ¹ is at least one alkali metal selected from the group consisting of Li, Na, K, Cs and Rb; X and X ′ are each a group consisting of Cl, Br and I At least one halogen selected;
And a is a numerical value in the range of 0 <a ≦ 10.0, and x is a numerical value in the range of 0 <x ≦ 0.2), a cerium-activated rare earth composite halide phosphor represented by a composition formula;

(12) JP-A-61-40390
LnPO described₄・ ALnX ₃: XCe
³⁺(However, Ln is composed of Y, La, Gd and Lu.
At least one rare earth element selected from the group consisting of
X is a member selected from the group consisting of F, Cl, Br and I.
At least one halogen; and a is 0.1 ≦ a
≦ 10.0, x is 0 <x ≦ 0.2
Cerium activation represented by the composition formula
Rare earth halophosphate phosphors;

(13) CsX: aRbX ': xEu ²⁺ described in Japanese Patent Application No. 60-78151 (wherein X and X' are each at least one member selected from the group consisting of Cl, Br and I) Halogen;
And a is a numerical value in the range of 0 <a ≦ 10.0, and x is a numerical value in the range of 0 <x ≦ 0.2). Divalent europium-activated cesium rubidium halide fluorescence represented by the composition formula: Body; and

[0025] (14) Japanese Patent Application No. Sho ^M 2 _X, which is described in 60-78153 Pat 2 ^· aM 1 X ': xEu
²⁺ (where M ² is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; M ¹ is at least one alkali metal selected from the group consisting of Li, Rb and Cs; X and X '
Is at least one halogen each selected from the group consisting of Cl, Br and I; and a is 0.1 ≦
a is a numerical value in the range of a ≦ 20.0, and x is 0 <x ≦ 0.2
And a divalent europium-activated composite halide phosphor represented by the following composition formula:

Among the above stimulable phosphors, a divalent europium-activated alkaline earth metal fluorohalide-based phosphor containing iodine and a divalent europium-activated alkaline earth metal halide containing iodine The iodine-containing rare earth element-activated rare earth oxyhalide-based phosphor and the iodine-containing bismuth-activated alkali metal halide-based phosphor exhibit high luminance stimulable luminescence.

A radiation image conversion panel using these stimulable phosphors emits stored energy by scanning with excitation light after accumulating radiation image information, so that the radiation image can be accumulated again after scanning. It can be used repeatedly. In other words, the conventional radiographic method consumes radiographic film for each photographing, whereas the radiographic image conversion method uses the radiographic image conversion panel repeatedly, which is advantageous in terms of resource conservation and economic efficiency. It is.

Therefore, it is desirable to provide the radiation image conversion panel with a performance that can withstand long-term use without deteriorating the image quality of the obtained radiation image.

However, the stimulable phosphor used in the manufacture of the radiation image conversion panel generally has a large hygroscopic property, and when left in a room under normal climatic conditions, absorbs the moisture in the air and deteriorates significantly with the passage of time. I do.

Specifically, for example, when a stimulable phosphor is placed under high humidity, the radiation sensitivity of the phosphor decreases with an increase in absorbed water. In general, since the latent image of a radiation image recorded on a stimulable phosphor regresses with the passage of time after irradiation, the intensity of the reproduced radiation image signal ranges from irradiation to scanning by excitation light. However, when the stimulable phosphor absorbs moisture, the latent image retreats faster.

Therefore, when a radiation image conversion panel having a stimulable phosphor that has absorbed moisture is used, the reproducibility of a reproduced signal at the time of reading a radiation image is reduced.

It is known that the stimulable phosphor particles generally have a stimulable property depending on the particle diameter.
No. 5-163500 describes that those having an average particle diameter of 1 to 30 μm are preferable. Further, the relationship between the phosphor particle size and characteristic values such as sensitivity, granularity, sharpness, etc. is as follows.
No. 79680.

Attempts to control the size and shape of these stimulable phosphor particles have been made by a liquid phase method as disclosed in JP-A-7-233369.
Here, as a conventional method, a method for producing a rare earth-activated alkaline earth metal fluorohalide-based stimulable phosphor is disclosed in Japanese Patent Application Laid-Open No. H10-157,197. Dry-mixing metal halides, rare earth halides, ammonium fluoride, etc. together,
Alternatively, a method is disclosed in which a rare-earth-activated alkaline earth metal fluorohalide-based stimulable phosphor is precipitated in an aqueous solution while being suspended and mixed in an aqueous medium, followed by firing and pulverization. .

The liquid phase method of precipitating a rare earth-activated alkaline earth metal fluorohalide-based stimulable phosphor in the above-mentioned aqueous solution does not cause deterioration in performance due to pulverization, and has a small particle size and uniform fluorescence. Body particles can now be obtained.

However, degradation due to moisture has become more problematic than ever before due to high sensitivity and small particle size. This deterioration starts at the moment the phosphor particles are exposed to the atmosphere after firing. To prevent this, it is conceivable to store the phosphor particles in an environment that is shielded from the atmosphere after firing. It is practically difficult to perform all steps in the preparation of a body plate in such an environment.

Conventionally, in order to prevent the above-mentioned deterioration phenomenon due to moisture absorption of the stimulable phosphor particles, a method using a titanate-based coupling agent described in JP-B-2-278196 and a silicone oil described in JP-B-5-52919 are disclosed. Have been devised, but none of them have reached a fundamental solution.

[0037]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in a radiation image conversion panel using a stimulable phosphor, and to provide a good condition for a long period without deterioration in performance due to moisture absorption. An object of the present invention is to provide a method for forming a stimulable phosphor which can be used and provide a radiation image conversion panel having high sharpness, luminance, and granularity, and a conversion panel using the same.

[0038]

Means for Solving the Problems The object of the present invention is to provide:
1. Average particle size 1 to 10 μm represented by the following general formula (1)
The method for producing a rare earth-activated alkaline earth metal fluorohalide-based stimulable phosphor according to the above method, wherein after firing, the particle size is 2 to 50 n.
a surface treatment with a silane coupling agent in the presence of at least one kind of metal oxide particles of m, a wet treatment under high-speed stirring conditions, wherein the rare earth-activated alkaline earth metal fluoride halide is used. method of forming a system stimulable phosphor particles, the general formula _{^{(1) Ba 1-x M}} 2 x FX: yM 1, zLn M 2: Mg, Ca, Sr, at least one selected from the group consisting of Zn and Cd Alkaline earth metal M ¹ : at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs X: at least one halogen selected from the group consisting of Cl, Br and I Ln: Ce, Pr, Sm, Eu, Gd, Tb, Tm, D
at least one rare earth element x, y, and z selected from the group consisting of y, Ho, Nd, Er, and Yb is 0 ≦ x ≦ 0.6, 0 ≦ y ≦
0.05, 0 <z ≦ 0.2

2. In the method for producing a rare earth activated alkaline earth metal fluorinated halide-based stimulable phosphor having an average particle diameter of 1 to 10 μm represented by the above general formula and prepared by a liquid phase method, after firing, the particle diameter is 2 to 2 μm. A surface treatment with a silane coupling agent in the presence of at least one metal oxide particle of 50 nm, wherein the wet treatment is performed under a high-speed stirring condition; Method for forming stimulable phosphor particles,

3. The metal oxide particles are 0.01% by weight or more and 10% by weight or less based on the stimulable phosphor particles;
2. The rare earth-activated alkaline earth metal fluorohalide as described in 1 above, wherein the amount of the silane coupling agent is 0.1% by weight or more and 5% by weight or less based on the stimulable phosphor particles. Method for forming stimulable phosphor particles,

4. 2. The method for forming rare earth-activated alkaline earth metal fluorohalide-based stimulable phosphor particles according to the above 1, wherein the silane coupling agent has a mercapto group;

5. At least one kind of metal oxide particles having a particle diameter of 2 to 50 nm is mixed with the stimulable phosphor precursor particles before firing in any of the above items 1 to 4, and the metal oxide particles are precursor particles. Characterized in that the amount is 0.01% by weight or more and 10% by weight or less.

6. A method of forming rare earth-activated alkaline earth metal fluoride halide stimulable phosphor particles, wherein the wet treatment in any one of the above 1 to 5 is high-speed stirring at a peripheral speed of 5 m / sec or more;

7. In any one of the above items 1 to 6, a method for forming a rare earth-activated alkaline earth metal fluorinated halide-based stimulable phosphor particle, wherein X in the general formula is I,

8. A radiation image conversion panel having a phosphor layer containing a stimulable phosphor, wherein the radiation image conversion panel contains the rare earth-activated alkaline earth metal fluoride halide stimulable phosphor according to any one of the above 1 to 7. And a radiation image conversion panel.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The present inventors have studied the general formula Ba _1-x M ² _x FX: yM ¹ ,
Investigating and studying the sensitivity degradation phenomenon of the stimulable phosphor represented by zLn due to moisture absorption, it was discovered that the performance degradation was caused by deliquescence of the phosphor due to moisture absorption and deterioration of the phosphor.

The above-described deliquescence refers to a phenomenon in which phosphor particles take water vapor in the air to form an aqueous solution on their own. Deterioration does not deliquify, but the fluorescent properties of the phosphor itself change due to water vapor in the air. Say that. Although the mechanism of the alteration is not clear, discoloration inside the phosphor particles may be considered.

The moisture absorption properties of the phosphor are considered to be caused by various causes such as capillary aggregation, but once water vapor is generated between the phosphor particles as water droplets, the performance degrades due to deliquescence.

The present inventors have conducted intensive studies to prevent these deterioration phenomena, and found that dephosphorization and deterioration of the phosphor can be prevented by coating the phosphor with a metal oxide and then treating with a silane coupling agent. Was found.

In general, an inorganic powder is mixed with a silane coupling agent.
A method of imparting water resistance by treating is known.
However, according to tests and studies by the present inventors, the general formula Ba
_1-xM ² _xFX: yM¹, Stimulable firefly represented by zLn
Include silicon with silane coupling agent directly on the surface of photoparticles
It was difficult to form a coated film.

When the surface treatment with the silane coupling agent is performed after the coating treatment of the metal oxide particles, the silicon-containing coating with the silane coupling agent fills the continuous phase so as to fill the periphery of the metal oxide particles dispersed on the phosphor particles. It is thought that the silane coupling agent functions effectively to form

When the phosphor particles after firing are coated with metal oxide particles and then surface-treated with a silane coupling agent, the phosphor particles having high moisture resistance are obtained, and at the same time, the sharpness and granularity are not changed and the sensitivity is remarkably high. That is, a phenomenon in which the luminance was improved was found. This phenomenon is generally caused by the fact that the phosphor deteriorates its performance when it is crushed, but on the other hand, when the metal oxide particles and the silane coupling agent are mixed with the phosphor after firing, a strong stirring operation is performed. Was found in the addition of

This phenomenon is considered to be related to the improvement of the moisture resistance, but the details are unknown. The present inventors have conducted many trial and error experiments on the timing and amount of addition of the metal oxide, the amount of the silane coupling agent, and the stirring conditions during the treatment, and as a result, the following has been found.

The metal oxide preferably has a particle size of 2 to 50 nm. 10% by weight of metal oxide based on phosphor
If the ratio exceeds 0.01%, the sensitivity is lowered, and if less than 0.01% by weight, the effect of the present invention is not observed. The timing of adding the metal oxide may be either before or after firing, or may be added separately before and after firing. As the kind of the metal oxide to be used, Al ₂ O ₃ , SiO ₂ , TiO ₃
Are industrially available representatives. These can be arbitrarily selected by conducting experiments in accordance with the phosphor to be used. For example, in the case of a barium fluoroiodide phosphor, Al ₂ O ₃ before firing and SiO ₂ after firing are particularly preferable.

In the case where the metal oxide is used before firing, any ordinary method can be used to mix an appropriate amount of the metal oxide with the phosphor particles having an average particle size of several μm to several tens μm. It is possible to use a mixing method such as a method in which phosphor particles are gradually added to the total amount of the metal oxide using a mixing device such as a turbula shaker mixer (manufactured by Shinmaru Enterprises Co., Ltd.). 0.5 to 10.0 wt
%, A method of stirring and then filtering and drying the phosphor particles in a metal oxide dispersion having a concentration of 0.1% is preferred from the viewpoint of uniform coating of the particles.

The wet treatment must be performed after the firing and before the dry crushing and pulverizing treatment. After the dry treatment, an improvement in moisture resistance is observed, but no improvement in sensitivity as in the present invention is observed. Most preferably, immediately after being taken out of the firing furnace.

In the wet treatment method, the metal oxide and the silane coupling agent are dispersed in an organic solvent under appropriate stirring.
The fired phosphor is added, and the mixture is stirred and mixed under stirring conditions described later. The peripheral speed of the stirring operation at the time of the surface treatment is preferably 5 m / sec or more, more preferably 8 m / sec or more. Although it is not clear why the sensitivity is improved by increasing the stirring operation, it is presumed that some effect is exerted between the silane coupling agent, the metal oxide particles, and the phosphor surface. Probably, when the stirring speed is low, the surface treatment is partially non-uniform, and the sensitivity is degraded more than where sufficient surface treatment is not performed. In such a case, when stored under high humidity, a yellowish yellowish color can be observed. It is considered that partial decomposition occurs. The present inventors used a biomixer manufactured by Nippon Seiki Co., Ltd. and a mixing analyzer manufactured by Tokushu Kika Kogyo Co., Ltd. to obtain the above peripheral speed. In any case, any stirring blade can be selected as long as it can perform high-speed stirring.

The silane coupling agents preferably used in the present invention include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-amino Ethylaminopropylmethyldimethoxysilane, γ-isocyanatopropyltriethoxysilane, methyltrimethoxysilane and the like can be mentioned. Particularly, a silane coupling agent having a mercapto group is a preferable example. When the amount of the silane coupling agent is 5% or more with respect to the amount of the phosphor, the sensitivity is reduced, the coating film is hardened, and cracks are generated on the film surface. Also 0.
If it is less than 1%, the effect of the present invention is not seen.

(Preparation of Panel, Phosphor Layer, Coating Step, Support, Protective Layer) As the support used in the radiation image conversion panel of the present invention, various polymer materials, glass, metal and the like are used. In particular, a material that can be processed into a flexible sheet or web on handling as an information recording material is preferable, and in this regard, a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyamide film, a polyimide film, a triacetate film, Plastic film such as polycarbonate film, aluminum, iron,
A metal sheet such as copper or chromium or a metal sheet having a coating layer of the metal oxide is preferable.

The layer thickness of the support varies depending on the material of the support to be used and the like.
The thickness is more preferably 80 μm to 500 μm from the viewpoint of handling.

The surface of these supports may be smooth or matte for the purpose of improving the adhesion to the stimulable phosphor layer.

Further, in these supports, an undercoat layer may be provided on the surface on which the stimulable phosphor layer is provided for the purpose of improving the adhesion to the stimulable phosphor layer.

Examples of the binder used in the stimulable phosphor layer in the present invention include proteins such as gelatin, polysaccharides such as dextran, and natural polymer substances such as gum arabic; and polyvinyl butyral, Vinyl acetate, nitrocellulose, ethyl cellulose, vinylidene chloride-vinyl chloride copolymer, polyalkyl (meth) acrylate, vinyl chloride-vinyl acetate copolymer, polyurethane, cellulose acetate butyrate,
Binders represented by synthetic high molecular substances such as polyvinyl alcohol and linear polyester can be used. Particularly preferred among such binders are nitrocellulose, linear polyesters, polyalkyl (meth) acrylates, mixtures of nitrocellulose and linear polyester, mixtures of nitrocellulose and polyalkyl (meth) acrylate, and polyurethanes. And polyvinyl butyral. In addition, these binders may be cross-linked by a cross-linking agent. The stimulable phosphor layer can be formed on the undercoat layer by the following method, for example.

First, an iodine-containing stimulable phosphor, a compound such as a phosphite for preventing yellowing, and a binder are added to an appropriate solvent, and these are mixed well to give a fluorescent solution in the binder solution. A coating solution in which body particles and particles of the compound are uniformly dispersed is prepared.

Generally, the binder is used in an amount of 0.01 to 1 part by weight based on 1 part by weight of the brilliant phosphor.

However, in terms of the sensitivity and sharpness of the obtained radiation image conversion panel, it is preferable that the amount of the binder is small, and the range of 0.03 to 0.2 part by weight is more preferable in view of the balance with ease of application.

The mixing ratio between the binder and the stimulable phosphor in the coating solution (however, when the entire binder is an epoxy group-containing compound, the mixing ratio is equal to the ratio between the compound and the phosphor)
The characteristics of the target radiation image conversion panel, the type of phosphor,
Depends on the amount of epoxy group-containing compound added, etc.
In general, examples of the solvent for preparing the binding coating solution include lower alcohols such as methanol, ethanol, 1-propanol, 2-propanol and n-butanol; hydrocarbons containing chlorine atoms such as methylene chloride and ethylene chloride; acetone and methyl ethyl ketone Ketones such as methyl isobutyl ketone; esters of lower fatty acids such as methyl acetate, ethyl acetate and butyl acetate with lower alcohols; ethers such as dioxane, ethylene glycol ethyl ether and ethylene glycol monomethyl ether; toluene; Can be mentioned.

Examples of the solvent used for preparing the coating solution for the stimulable phosphor layer include lower alcohols such as methanol, ethanol, isopropanol and n-butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like.
Ketones such as cyclohexanone, esters of lower fatty acids such as methyl acetate, ethyl acetate and n-butyl acetate with lower alcohols, dioxane, ethers such as ethylene glycol monoethyl ether and ethylene glycol monomethyl ether, aromatic compounds such as triol and xylol And halogenated hydrocarbons such as methylene chloride and ethylene chloride, and mixtures thereof.

The coating solution contains a dispersant for improving the dispersibility of the phosphor in the coating solution, and a binder between the binder and the phosphor in the stimulable phosphor layer after formation. Various additives such as a plasticizer for improving the bonding strength may be mixed. Examples of dispersants used for such purposes include phthalic acid, stearic acid, caproic acid,
Lipophilic surfactants and the like can be mentioned. Examples of the plasticizer include phosphate esters such as triphenyl phosphate, tricresyl phosphate, and diphenyl phosphate; phthalate esters such as diethyl phthalate and dimethoxyethyl phthalate;
Glycolic acid esters such as ethylphthalylethyl glycolate and butylphthalylbutyl glycolate; and
Examples include polyesters of polyethylene glycol and fatty acid dibasic acid, such as polyesters of triethylene glycol and adipic acid, and polyesters of diethylene glycol and succinic acid.

In order to improve the dispersibility of the stimulable phosphor layer phosphor particles in the stimulable phosphor layer coating solution, stearic acid, phthalic acid, caproic acid, lipophilic surfactants, etc. May be mixed. If necessary, a plasticizer for the binder may be added. Examples of the plasticizer include phthalic acid esters such as diethyl phthalate and dibutyl phthalate, fatty acid dibasic acid esters such as diisodecyl succinate and dioctyl adipate, ethylphthalylethyl glycolate, butylphthalylbutyl glycolate and the like. And the like.

Next, the coating solution prepared as described above is uniformly applied to the surface of the undercoat layer to form a coating film of the coating solution. This coating operation can be performed by using ordinary coating means, for example, a doctor blade, a roll coater, a knife coater, or the like.

Next, the formed coating film is dried by gradually heating to complete the formation of the stimulable phosphor layer on the undercoat layer. The thickness of the stimulable phosphor layer depends on the characteristics of the target radiation image conversion panel, the type of the stimulable phosphor, the mixing ratio of the binder and the phosphor, and the like.
μm to 1 mm. However, this layer thickness is 50 to 500
It is preferably set to μm.

The coating solution for the stimulable phosphor layer is prepared by using a dispersing device such as a ball mill, a sand mill, an attritor, a three-roll mill, a high-speed impeller disperser, a Kady mill, and an ultrasonic disperser. The prepared coating solution is applied to a support using a coating solution such as a doctor blade, a roll coater, or a knife coater, and dried to form a stimulable phosphor layer. The stimulable phosphor layer and the support may be bonded to each other after the coating solution is applied on the protective layer and dried.

The thickness of the stimulable phosphor layer of the radiation image conversion panel of the present invention depends on the characteristics of the intended radiation image conversion panel, the type of stimulable phosphor, and the difference between the binder and the stimulable phosphor. Although it depends on the mixing ratio and the like, it is preferably selected from the range of 10 μm to 1000 μm, more preferably from the range of 10 μm to 500 μm. A phosphor sheet having a phosphor layer coated on a support is cut into a predetermined size. Any general method can be used for cutting, but a cosmetic cutting machine, a punching machine, or the like is desirable in terms of workability and accuracy.

The phosphor sheet cut to a predetermined size is generally sealed with a moisture-proof protective film. Examples of the sealing method include, for example, a method in which a phosphor sheet is sandwiched between upper and lower moisture-proof protective films, and a peripheral portion is heated and fused with an impulse sealer, or a lamination method in which pressure is applied between two heated rollers. And the like.

In the method of heat-sealing with the impulse sealer, the heat-sealing under a reduced pressure environment means that the phosphor sheet is prevented from being displaced in the moisture-proof protective film and the moisture in the air is eliminated. More preferred.

[0077]

The present invention will now be illustrated by way of examples.
In the following, an example of a stimulable phosphor of europium-activated barium fluoroiodide will be mainly described, but a stimulable phosphor represented by general formula (1) other than europium-activated barium fluorobromide will be described. The same applies to the production of. The metal oxides and silane coupling agents used in Comparative Examples and Examples are as follows.

<Metal oxide particles> A1: Hydrophobized silica particles (manufactured by Nippon Aerosil Co., Ltd .: dimethyldichlorosilane-treated product) Particle size 7 nm A2: Hydrophobized silica particles (Nippon Aerosil Co., Ltd .: octylsilane) A3: Alumina particles 13 nm in particle size

<Silane Coupling Agent> B1: γ-mercaptopropyltrimethoxysilane B2: γ-mercaptopropylmethyldimethoxysilane B3: vinyltriethoxysilane

Comparative Example 1 In order to synthesize a stimulable phosphor precursor of europium-activated barium fluoroiodide, an aqueous BaI2 solution (1.75 mol) was used.
l / l) 2500 ml and EuBr ₃ aqueous solution (0.067
mol / l) was placed in the reactor. The reaction mother liquor in this reactor was kept at 83 ° C. while stirring. 250 ml of an ammonium fluoride aqueous solution (8 mol / l) was injected into the reaction mother liquor using a roller pump to form a precipitate. After completion of the pouring, the precipitate was aged by keeping the temperature and stirring for 2 hours. Next, the precipitate was separated by filtration, washed with methanol, and dried under vacuum to obtain europium-activated barium fluoroiodide crystals. Fill this into a quartz boat,
Firing was performed at 850 ° C. for 2 hours in a hydrogen gas atmosphere using a tube furnace to obtain europium-activated barium fluoroiodide phosphor particles.

Next, the phosphor was immersed in an ethanol dispersion liquid containing 1.0% by weight of fine metal particles A1 and 1.0% by weight of a silane coupling agent B1 with respect to the obtained phosphor to form a slurry. Crushed and dried at 80 ° C. for 3 hours. After drying, the particles were classified to obtain particles having an average particle diameter of 7 μm.

Next, a radiation image conversion panel was prepared.

As the phosphor layer forming material, 427 g of the europium-activated barium fluoroiodide phosphor obtained above, 15.8 g of a polyurethane resin (Desmolac 4125, manufactured by Sumitomo Bayer Urethane Co., Ltd.), and bisphenol A type epoxy resin 0 g of methyl ethyl ketone-toluene (1:
1) The mixture was added to a mixed solvent and dispersed by a propeller mixer to prepare a coating solution having a viscosity of 25 to 30 PS. This coating solution was applied on a polyethylene terephthalate film with an undercoat using a doctor blade,
After drying for minutes, a phosphor layer having a thickness of 230 μm was formed. Next, the obtained radiation image conversion panel was sealed.

The above coated sample was cut into a square of 5 cm × 5 cm, and a general polyethylene terephthalate (P) was cut.
ET) 12 μm / cast polypropylene (CP
P) A 30 μm laminated protective film was used, and the periphery was sealed by fusing under reduced pressure using an impulse sealer.

The fusion was performed so that the distance from the fusion portion to the periphery of the phosphor sheet was 1 mm. The heater of the impulse sealer used for fusion had a width of 3 mm.

Comparative Example 2 0.2% by weight based on the stimulable phosphor precursor particles before firing.
A sealed radiation image conversion panel was prepared in the same manner as in Comparative Example 1, except that the metal fine particles A3 were mixed and baked for 10 minutes using a turbula shaker mixer (manufactured by Shinmaru Enterprises). Comparative Example 3 The same procedure as in Comparative Example 2 was carried out except that the mixture with the silane clinker agent and the metal fine particles after firing was stirred at a peripheral speed of 2 m / sec for 70 minutes using a 28 mm diameter biomixer impeller manufactured by Nippon Seiki Co., Ltd. Thus, a sealed radiation image conversion panel was prepared.

Comparative Example 4 Comparative Example 2 except that the baked silane clinker agent and the metal fine particles were mixed with a Nippon Seiki Co., Ltd .: Biomixer Impeller having a diameter of 28 mm and stirred at a peripheral speed of 4 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in the above.

COMPARATIVE EXAMPLE 5 A mixture of the calcined silane coupling agent and the metal fine particles was mixed with Nippon Seiki Co., Ltd .: Biomixer Impeller having a diameter of 28 mm and stirred at a peripheral speed of 4 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in Comparative Example 2 except that B2 was used as the agent.

COMPARATIVE EXAMPLE 6 A mixture of the calcined silane coupling agent and the fine metal particles was mixed with a biomixer having a diameter of 28 mm manufactured by Nippon Seiki Co., Ltd., and stirred for 70 minutes at a peripheral speed of 4 m / sec. A sealed radiation image conversion panel was prepared in the same manner as in Comparative Example 2 except that B3 was used.

Example 1 Comparative Example 2 except that the baked silane clinker agent and the metal fine particles were mixed with a fine particle of 28 mm manufactured by Nippon Seiki Co., Ltd. at a peripheral speed of 5 m / sec for 70 minutes using a biomixer impeller having a diameter of 28 mm. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 2 Comparative Example 2 except that the baked silane cufflink agent and the metal fine particles were mixed with Nippon Seiki Co., Ltd .: Biomixer Impeller having a diameter of 28 mm and stirred at a peripheral speed of 9 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 3 Comparative Example 2 except that the baked silane cufflink agent and the metal fine particles were mixed with Nippon Seiki Co., Ltd. using a biomixer impeller with a diameter of 28 mm at a peripheral speed of 13 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 4 A mixture of the calcined silane coupling agent and the metal fine particles was mixed with a biomixer having a diameter of 28 mm manufactured by Nippon Seiki Co., Ltd. for 70 minutes at a peripheral speed of 9 m / sec. A sealed radiation image conversion panel was prepared in the same manner as in Comparative Example 2 except that B2 was used as the agent.

Comparative Example 7 In order to synthesize a stimulable phosphor precursor of europium-activated barium fluoroiodide, a BaI ₂ aqueous solution (4.0 mol) was used.
/ L) 2500 ml and EuI ₃ aqueous solution (0.2 mol /
l) 26.5 ml were placed in the reactor. The reaction mother liquor in this reactor was kept at 83 ° C. while stirring. 322 ml of an aqueous ammonium fluoride solution (8.0 mol / l) was injected into the reaction mother liquor using a roller pump to form a precipitate. After completion of the pouring, the precipitate was aged by keeping the temperature and stirring for 2 hours. Next, the precipitate was separated by filtration, washed with methanol, and dried under vacuum to obtain europium-activated barium fluoroiodide crystals.

The obtained stimulable phosphor precursor was charged into a quartz furnace core tube of a batch type rotary kiln having a furnace core volume of 10 liters, and a 95% nitrogen / 5% hydrogen mixed gas was charged into 10%.
Liter / min. At a flow rate of 20 minutes to replace the atmosphere. After fully replacing the atmosphere in the furnace core, 95%
The flow rate of the nitrogen / 5% hydrogen mixed gas is 2 liter / min.
While rotating the furnace core at a speed of 2 rpm.
0 ° C./min. At a heating rate of 850 ° C.

After the sample temperature reaches 850 ° C., a mixed gas of 93% nitrogen / 5% hydrogen / 2% oxygen is supplied at 10 liter / min. At a flow rate of 20 minutes to replace the atmosphere. Then 93% nitrogen / 5%
The flow rate of the mixed gas of hydrogen / 2% oxygen is 2 liter / mi
n. And held for 20 minutes.

Next, a mixed gas of 5% hydrogen / 95% nitrogen was added to 10%.
Liter / min. At a flow rate of 20 minutes to replace the atmosphere. After fully replacing the atmosphere in the furnace core, 95%
The flow rate of the nitrogen / 5% hydrogen mixed gas is 2 liter / min.
And held for 60 minutes.

Thereafter, the flow rate of the mixed gas of 5% hydrogen / 95% nitrogen was set to 2 liter / min. 10 ℃ / mi
n. After cooling to room temperature (25 ° C.) at the temperature lowering rate, the atmosphere was returned to the atmosphere to obtain the produced europium-activated barium fluoroiodide phosphor particles.

Next, the phosphor was immersed in an ethanol dispersion liquid containing 1.0% by weight of fine metal particles A1 and 1.0% by weight of a silane coupling agent B1 with respect to the obtained phosphor to form a slurry. Crushed and dried at 80 ° C. for 3 hours. Thereafter, the particles were classified and coarse particles were removed to obtain stimulable phosphor particles having an average particle diameter of 2 μm.

(Radio image conversion panel) As a phosphor layer forming material, 427 g of europium-activated barium fluoroiodide phosphor obtained above and 15.8 g of polyurethane resin (Desmolac 4125, manufactured by Sumitomo Bayer Urethane Co., Ltd.). ,
2.0 g of bisphenol A type epoxy resin was added to a mixed solvent of methyl ethyl ketone-toluene (1: 1) and dispersed by a propeller mixer to prepare a coating solution having a viscosity of 25 to 30 PS. This coating solution was applied on a polyethylene terephthalate film with an undercoat using a doctor blade, and then dried at 100 ° C. for 15 minutes to give 230 μm.
Was formed. The coated sample was sealed with a protective film as in Comparative Example 1.

Comparative Example 8 0.2% by weight based on the stimulable phosphor precursor particles before firing
A sealed radiation image conversion panel was prepared in the same manner as in Comparative Example 7, except that the metal fine particles A3 of the above were mixed and baked for 10 minutes using a turbula shaker mixer (manufactured by Shinmaru Enterprises).

Comparative Example 9 Comparative Example 8 was repeated except that the baked silane clinker and the metal fine particles were mixed with a fine particle of 28 mm manufactured by Nippon Seiki Co., Ltd. for 70 minutes at a peripheral speed of 2 m / sec. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Comparative Example 10 Comparative Example 8 was repeated except that the baked silane clinker agent and the metal fine particles were mixed with Nippon Seiki Co., Ltd. for 70 minutes at a peripheral speed of 4 m / sec using a Biomixer Impeller diameter of 28 mm. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 5 Comparative Example 8 except that the mixture of the calcined silane cufflink agent and the metal fine particles was mixed with Nippon Seiki Co., Ltd .: Biomixer Impeller having a diameter of 28 mm at a peripheral speed of 5 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 6 Comparative Example 8 except that the mixture of the baked silane cufflinking agent and the metal fine particles was mixed with a Nippon Seiki Co., Ltd .: Biomixer Impeller having a diameter of 28 mm at a peripheral speed of 9 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 7 Comparative Example 8 was repeated except that the mixture of the calcined silane cufflink agent and the fine metal particles was stirred for 70 minutes at a peripheral speed of 13 m / sec using a biomixer impeller diameter 28 mm manufactured by Nippon Seiki Co., Ltd. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 8 The baked silane coupling agent and the fine metal particles were mixed with a Nippon Seiki Co., Ltd .: Biomixer with a diameter of 28 mm and stirred at a peripheral speed of 9 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in Comparative Example 8 except that B2 was used as the agent.

Example 9 A mixture of the silane clinker agent and metal fine particles after firing was mixed with a biomixer impeller having a diameter of 28 mm manufactured by Nippon Seiki Co., Ltd. for 70 minutes at a peripheral speed of 9 m / sec. A sealed radiation image conversion panel was prepared in the same manner as in Comparative Example 8 except that was used.

Example 10 A mixture of the silane clinker agent and metal fine particles after firing was mixed with a biomixer impeller having a diameter of 28 mm manufactured by Nippon Seiki Co., Ltd., and stirred at a peripheral speed of 9 m / sec for 70 minutes. Comparative Example 8 except that B2 was used as the silane coupling agent
A sealed radiation image conversion panel was prepared in the same manner as in the above.

Example 11 Comparative Example 7 was repeated except that the mixture of the calcined silane clinker agent and the metal fine particles was mixed with a biomixer impeller having a diameter of 28 mm manufactured by Nippon Seiki Co., Ltd. at a peripheral speed of 9 m / sec for 70 minutes. A sealed radiation image conversion panel was prepared in the same manner as in the above.

Evaluation of Moisture Resistance The prepared sample was left for 10 days in an environment of 40 ° C. and 90%, and the ratio of the initial sensitivity and the subsequent sensitivity was calculated. In this case, the closer the value is to 1, the less the sensitivity degradation. The values in the table are average values of 10 samples.

The sensitivity was measured by irradiating the radiation image conversion panel with X-rays having a tube voltage of 80 KVp, and then applying He-N
Excitation is performed by operating with e-laser light (633 nm), and stimulated emission emitted from the phosphor layer is received by a photodetector (photoelectron image multiplier with a spectral sensitivity of S-5) and its intensity is measured. Was.

The initial sensitivities in the tables are normalized to 1.0 in Comparative Example 1 in Comparative Examples 1 to 6 and Examples 1 to 4. or,
Comparative Examples 7 to 10 and Examples 5 to 10 correspond to Comparative Example 7 in which 1.
It is standardized as 0.

As can be seen from the table, according to the present invention, it is possible to obtain a phosphor plate with less sensitivity deterioration due to moisture absorption and high initial sensitivity. In the sample having poor moisture resistance, a white phosphor plate is observed to have a yellowish color like a cod, and the sensitivity is deteriorated.

[0115]

[Table 1]

Note: The amounts in the table indicate the ratio (wt%) to the amount of the phosphor particles.

[0117]

According to the present invention, there is provided a radiation image conversion panel which can be used in a good condition for a long period without deterioration in performance due to moisture absorption, and has high sharpness, brightness and granularity. A method for forming a phosphor and a conversion panel using the same can be provided.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takehiko Shoko 1 Sakura-cho, Hino-shi, Tokyo Inside Konica Corporation (72) Inventor Tetsuya Yoshida 1-Sakura-cho, Hino-shi, Tokyo Inside Konica Corporation (72) Inventor Hiroto Ito 1 Sakura-cho, Hino-shi, Tokyo F-term in Konica Corporation (Reference) 2G083 AA03 BB01 DD01 DD02 DD06 DD11 DD12 DD15 EE02 EE03 EE08 2H013 AC01 4H001 CA04 CA08 XA09 XA12 XA17 XA20 XA30 XA35 XA38 XA38 XA38 XA38 XA38 XA38 XA38 XA38 XA38 XA38 XA38 XA38 YA37 YA55 YA58 YA59 YA60 YA62 YA63 YA64 YA65 YA66 YA67 YA68 YA69 YA70

Claims (8)

[Claims] An average particle size of 1 to 1 represented by the following general formula (1):
In a method for producing a 10 μm rare earth activated alkaline earth metal fluorohalide-based stimulable phosphor, a particle size of 2
A surface treatment with a silane coupling agent in the presence of at least one kind of metal oxide particles having a diameter of from 50 to 50 nm, wherein the wet treatment is carried out under high-speed stirring conditions. Of forming phosphor-based stimulable phosphor particles. General formula (1) Ba _1-x M ² _x FX: yM ¹ , zLn M ² : at least one kind of alkaline earth metal M ¹ : Li, Na, selected from the group consisting of Mg, Ca, Sr, Zn and Cd At least one alkali metal selected from the group consisting of K, Rb and Cs X: at least one halogen selected from the group consisting of Cl, Br and I Ln: Ce, Pr, Sm, Eu, Gd, Tb, Tm, D
at least one rare earth element x, y, and z selected from the group consisting of y, Ho, Nd, Er, and Yb is 0 ≦ x ≦ 0.6, 0 ≦ y ≦
0.05, 0 <z ≦ 0.2 2. A method for producing a rare earth activated alkaline earth metal fluoride halide stimulable phosphor having an average particle diameter of 1 to 10 μm represented by the above general formula and prepared by a liquid phase method, comprising the steps of: A surface treatment with a silane coupling agent in the presence of at least one kind of metal oxide particles having a particle diameter of 2 to 50 nm, wherein the wet treatment is performed under a high-speed stirring condition. A method for forming metal fluorinated halide-based stimulable phosphor particles. 3. The method according to claim 1, wherein the metal oxide particles are present in an amount of 0.01% by weight or more and 10% by weight or less based on the stimulable phosphor particles, and the amount of the silane coupling agent is based on the stimulable phosphor particles. The method for forming rare earth-activated alkaline earth metal fluorinated halide-based stimulable phosphor particles according to claim 1, wherein the content is from 0.1% by weight to 5% by weight. 4. The method according to claim 1, wherein the silane coupling agent has a mercapto group. 4. The method according to claim 1, wherein the fluorinated phosphor particles are a rare earth activated alkaline earth metal halide. 5. The method according to claim 1, wherein at least one kind of metal oxide particles having a particle size of 2 to 50 nm is mixed with the stimulable phosphor precursor particles before firing, and Wherein the material particles are at least 0.01% by weight and at most 10% by weight with respect to the precursor particles. 6. A rare earth activated alkaline earth metal fluoride halide stimulable phosphor, wherein the wet treatment according to claim 1 is a high-speed stirring at a peripheral speed of 5 m / sec or more. Method of forming particles. 7. A method for forming a rare earth activated alkaline earth metal fluoride halide stimulable phosphor particle according to claim 1, wherein X in the general formula is I. . 8. A radiation image conversion panel having a phosphor layer containing a stimulable phosphor, wherein the rare earth-activated alkaline earth metal fluorinated halide stimulable phosphor according to any one of claims 1 to 7. A radiation image conversion panel comprising a body.