JPS60139783A - Phosphor and radiation image converting panel using the same - Google Patents

Abstract

PURPOSE:To improve stimulable afterglow characteristics without lowering stimulated emission brightness, by incorporating a specified quantity of calcium in a bivalent europium-activated barium fluorohalide phosphor contg. a sodium halide. CONSTITUTION:Barium fluoride, a barium halide, a calcium halide, a sodium halide and a europium compd. are mixed together in such a proportion as to satisfy stoichiometrically the relationship of formula I ( wherein X, X' are each Cl, Br, I; 0<a<=10<-1>; 0<b<=2.0; 0<x<=0.2). The mixture is dried, crushed packed in a quartz boat, and calcined in a weakly reducing atmosphere to obtain the desired bivalent europium-activated barium fluorohalide phosphor of formula II. A stimulable phosphor layer contg. the phosphor is provided on a support to obtain a radiation image converting panel giving an image of excellent quality.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phosphor and a radiation image conversion panel using the same. More specifically, the present invention relates to a divalent europium-activated barium fluoride halide phosphor and a radiation image conversion panel using this phosphor.

In recent years, barium fluoride halide phosphors (BaFX: Eu2+, however,
When X is at least one type of halogen selected from the group consisting of C1, Br, and H), when irradiated with radiation such as X-rays, it absorbs and accumulates a part of the energy,
It has been found that when irradiated with electromagnetic waves in the wavelength range of 450 to 900 nm, the phosphor emits light in the near ultraviolet to blue region, that is, the phosphor exhibits stimulated luminescence. The peak wavelength is in the wavelength range of about 385-405 nm depending on the type of halogen that is a component of the phosphor). In particular, this divalent europium-activated barium fluoride halide phosphor is extremely useful as a phosphor for radiation image conversion panels (stimulable phosphor sheets) used in radiation image recording and reproducing methods that utilize urinary phosphors. has attracted attention and many studies are being conducted.

The basic structure of the radiation image storage panel is a support,
The phosphor layer is formed of a binder containing and supporting at least one stimulable phosphor in a dispersed state, provided on one side of the phosphor layer. Note that a transparent protective film is generally provided on the surface of the phosphor layer opposite to the support (the surface not facing the support) to protect the phosphor layer from chemical deterioration or Protects from physical impact.

The radiation image recording and reproducing method using the radiation image conversion panel made of the above-mentioned stimulable phosphor is an effective alternative to the conventional radiography method.
As described in the above publication, the radiation energy transmitted through the subject or emitted from the subject is absorbed by the stimulable phosphor constituting the radiation image conversion panel,
Thereafter, by exciting the stimulable phosphor in a time-series manner with electromagnetic waves (excitation light) selected from visible light and infrared rays, the radiation energy accumulated in the stimulable phosphor is released as fluorescence, This fluorescence is read and captured photoelectrically to obtain an electrical signal, which is then reproduced as a visible image on a recording material such as a photosensitive film or a display device such as a CRT.

The above-described radiation image recording and reproducing method has the advantage that a radiation image with a rich amount of information can be obtained with a much lower exposure dose than when conventional radiography is used. Therefore, this radiation image recording and reproducing method is
It is particularly useful in direct medical radiography such as X-ray photography for the purpose of medical diagnosis.

In carrying out the radiation image recording and reproducing method described above, the readout operation of the radiation energy stored in the radiation image conversion panel usually uses a laser beam as excitation light, and first scans the panel with this laser beam to read out the radiation energy stored in the radiation image conversion panel. This is done by exciting the stimulable phosphor in a time-series manner to emit the accumulated radiation energy as fluorescence, and then detecting this fluorescence with a photodetector.

Therefore, the fluorescence that the stimulable phosphor used in the radiation image conversion panel continues to emit even after the excitation by the excitation light has stopped, that is, the afterglow (stimulated afterglow), is caused by groups of phosphor particles other than the irradiation target. This causes a problem as it is detected as light emitted from the rays and causes a decrease in the S/N ratio of the obtained image. In other words, if a phosphor emits photostimulated afterglow at a considerable ratio to the amount of photostimulated light, the light emission (afterglow) from a group of phosphor particles other than the irradiation target will be absorbed by the phosphor of the irradiation target. Since it is detected mixed with the emitted light from the particle group, images obtained by radiation image conversion panels containing such phosphors tend to have reduced image quality (sharpness, concentration resolution, etc.). be.

However, the degree of influence of the afterglow characteristic (stimulated afterglow characteristic) of such #exhaustive phosphor on image quality also changes depending on the scanning speed of excitation light and the like. Furthermore, in actual use, the influence of the stimulated afterglow on the image quality varies depending on the method of detecting stimulated luminescence. However, it can be said that it is of great significance to improve the photostimulation afterglow characteristic, which has an adverse effect on image quality.

Furthermore, although the radiation image recording and reproducing method using a radiation image conversion panel made of stimulable phosphor is a very advantageous image forming method as described above, it is desirable that the sensitivity of this method be as high as possible. Generally, the sensitivity of a radiation image storage panel to radiation increases as the stimulated luminance of the phosphor used therein increases. Therefore, it is desired that the stimulable phosphor used in the panel has as high a stimulable luminance as possible.

Patent application filed by the inventor on September 24, 1982
As described in Japanese Patent Application No. 166320, adding sodium halide in an amount within a specific range to the divalent europium-activated barium fluoride halide phosphor improves its stimulated luminescence brightness. That is, its compositional formula is B aFX@aN aX':xEu" (wherein X and X' are both at least one kind of halogen selected from the group consisting of C1, Br, and Ova≦2.0 and 0<x≦0.2) A divalent europium-activated barium fluoride halide phosphor containing sodium halide is a phosphor without the addition of sodium halide. However, on the other hand, the addition of sodium halide to the divalent europium-activated fluoride I/barium halide phosphor deteriorates the stimulated afterglow properties of the phosphor. Therefore, it is desired to improve the stimulated afterglow characteristics of the divalent europium activated barium fluoride/X fluoride-based phosphor containing sodium /X rogenide represented by the above composition formula.

Therefore, the present invention provides an I that has improved stimulated afterglow characteristics without substantially reducing the stimulated luminescence brightness when excited with light in the excitation wavelength region of stimulated luminescence after irradiation with radiation such as X-rays. The object of the present invention is to provide a divalent europium-activated barium fluoride halide phosphor containing sodium halogenide.

Furthermore, another object of the present invention is to provide a radiation image conversion panel using the phosphor in which the quality of the obtained image is improved without substantially reducing the sensitivity.

In order to achieve the above object, the present inventors conducted various studies on sodium halide-containing divalent europium-activated barium fluoride halide phosphors. As a result, it was discovered that by containing calcium in a certain range in the phosphor, the stimulated afterglow characteristics can be significantly improved without substantially reducing the brightness of stimulated luminescence, and the present invention has been reached.

That is, the phosphor of the present invention has the composition formula (I): (Bal
-aI Caa)FXe bNaX”:xEu-...
(1) (However, X and X゛ are both C1, Br and ■
at least one kind of halogen selected from the group consisting of; and a, b and X each represent 0<a≦10-
divalent europium-activated halogen fluoride containing a specific amount of calcium in addition to a specific amount of sodium halide expressed as ``, o<b≦2.0 and Ox≦0.2] It is a barium chloride-based phosphor.

Further, the radiation image conversion panel of the present invention is a radiation image conversion panel substantially composed of a support and a photostimulable phosphor layer provided thereon, in which the photostimulable phosphor layer is It is characterized by containing a divalent europium-activated barium fluoride halide phosphor represented by the composition formula CI).

The present invention provides that the divalent europium-activated barium fluoride halide phosphor represented by the above composition formula (I) has a significantly improved photostimulated afterglow property, especially after irradiation with excitation light of 10-" to 1
This was completed based on the new knowledge that it exhibits significantly improved photostimulation afterglow characteristics near O-2 seconds.

Furthermore, the phosphor of the present invention represented by the above compositional formula (I) is similar to the divalent europium-activated barium fluoride halide phosphor and the sodium halide-containing divalent europium-activated barium fluoride halide phosphor. , X
When excited with electromagnetic waves in the wavelength range of 450 to 900 nm after irradiation with radiation such as radiation, it exhibits stimulated luminescence, but the luminance of the stimulated luminescence is lower than that of the latter phosphor () which does not contain calcium.
It has been found that there is almost no decrease compared to a divalent europium-activated barium fluoride halide phosphor containing sodium halide.

Therefore, by using the radiation image storage panel of the present invention using the divalent europium-activated barium fluoride halide phosphor represented by the above composition formula (I), the sensitivity of the radiation image recording and reproducing method can be improved. At the same time, it is possible to constantly obtain images with excellent image quality.

Next, the present invention will be explained in detail.

The divalent europium-activated barium fluoride halide phosphor of the present invention has a composition formula (I): (Bal-a, Caa)FX@bNaX':xEu2+
,...(I) Defeat However, X and X'' are both at least one kind of halogen selected from the group consisting of C1, Br, and E; and a, b, and X each satisfy Ova≦io-
', 0xb≦2.0 and Oxx≦0.2).

In the phosphor of the present invention represented by the above compositional formula (I), after irradiation with radiation such as X-rays, 450 to 900 nm
From the viewpoint of stimulated luminescence brightness and stimulated afterglow characteristics when excited by electromagnetic waves in the wavelength range of Preferred. Particularly preferred.

is in the range of 3 X 10-''≦a≦5XIO-.Mainly from the point of view of stimulated luminescence brightness, Na is 10'≦b≦5XIO-”
It is preferably within the range of , more preferably 5×lθ
″≦b≦lθ′.

From the viewpoint of stimulated luminescence brightness, it is preferable that in the above compositional formula, ~900. nm wavelength range, but its peak wavelength depends on the halogen
, Br, and I gradually shift toward longer wavelengths in this order. Therefore, He, which is currently being considered for practical use as a light source for excitation light,
- From the point of view of matching with Ne laser (6,33 nm), semiconductor laser (infrared radiation), etc., it is preferable that X representing halogen is at least one of Br and I. The expressed X value is determined from both the photostimulated luminance brightness and the afterglow characteristics.
It is preferable that IO'≦X≦1O-2.

(Bat-a, Caa)FBr*0.0023N, which is an example of the phosphor of the present invention represented by the above compositional formula (I)
a B r : 0.001 E u 2+ For a radiation image storage panel having a phosphor layer containing phosphor dispersed in a binder, the a value representing the calcium content in the phosphor and the photostimulation residual The relationship between the amount of light, the a value, and the sensitivity (that is, the stimulated luminance of the phosphor) is as shown in FIG. 2.

In Fig. 2, the solid line indicates the a value and 2 after scanning with excitation light.
Relative afterglow amount in XIO-' seconds ([exhaust afterglow amount/
This is a graph showing the relationship between the logarithm of the
The dotted line is a graph showing the relationship between the a value and relative sensitivity.

As is clear from FIG. 2, the above (Ba+-a).

Ca &) FB r 110.0023 NaB r:
In a radiation image conversion panel containing a 0.001E u-phosphor, when the calcium content (ff1Ca value) is less than 1O-1, the relative amount of stimulated afterglow decreases (i.e., the luminance decreases) with almost no decrease in sensitivity. (improves afterglow properties)
.

However, when the a value exceeds 10-1, the sensitivity decreases significantly. Then, a(a is 10−”≦a≦5×1
It is clear that in the range of 0''4, the panel using this phosphor has significantly improved photostimulation afterglow characteristics without causing a decrease in sensitivity.

Furthermore, the stimulated afterglow characteristic has an a value of 3 X I O-3≦
It is clear that a significant improvement is achieved when a≦5X l O-2.

It has been confirmed that this tendency similarly appears in radiation image storage panels using other divalent europium-activated barium fluoride halide phosphors represented by the compositional formula (I).

Furthermore, it is preferable that the calcium content (a value) is small in terms of absorption efficiency of radiation such as X-rays and hygroscopicity of the obtained phosphor, and taking this point into consideration, the a value is was set in the range of 0<a≦10−”.

In addition, the divalent europium activated fluoride halogenated/
The helium-based phosphor has the above composition formula (I) as its basic composition.
In its production, various additive components may be added as long as the effect of including Ca (improvement of photostimulated afterglow characteristics) is not lost, and such additive components Phosphors containing these are also included in the phosphors of the present invention. Specific examples of additive components include the following substances.

Metal oxides as described in Japanese Patent Application No. 55-160078; Tetrafluoroboric acid compounds as described in Japanese Patent Application No. 57-137374; Japanese Patent Application No. 57-158048 Hexafluoro compounds such as those described in
X
at least one alkali metal selected from the group consisting of s;
At least one halogen selected from the group consisting of Be and Mg), a halide of a divalent metal (M" ”° is F, C51, Br and I
(at least one halogen selected from the group consisting of) and a trivalent metal halide (M"X"3; metal, X” is F,
At least one halogen selected from the group consisting of C, Br and I); Zr and Sc described in JP-A-56-116777; JP-A-57-2
B described in Publication No. 3673; -2
As and Si as described in Japanese Patent Application No. 3675; and transition metals as described in Japanese Patent Application No. 57-166696.

The addition of metal oxides as described in JP-A No. 5'5-160078 is particularly useful for preventing sintering of the phosphor in the firing process, and for increasing the 4 degree and 4 degree stimulated luminescence of the obtained phosphor. Effective in improving powder fluidity. When adding a metal oxide, the reason is (B aI-iiL'+
Ca&) FXI ranges from 0.3 mol to 0.3 mol, more preferably from 10-' to 0.2 mol, based on %k.

Particularly preferable metal oxides include 5i02 and A2
o3 is mentioned.

The divalent europium-activated barium fluoride halide phosphor of the present invention represented by the above compositional formula (I) can be produced, for example, by the production method described below.

First, as phosphor raw materials, 1) barium fluoride, 2) barium halide (excluding barium fluoride), 3) calcium halide, 4) sodium halide (excluding sodium fluoride), and 5) At least one europium compound selected from the group consisting of europium compounds such as halides, oxides, nitrates, and sulfates is prepared. In some cases, ammonium halide or the like may also be used as a flux.

When producing a phosphor, first, using the above barium fluoride (1), barium halide (2), calcium halide (3), sodium halide (4) and europium compound (5), stoichiometric , Composition formula (■): (Bal-a, Ca5.)FXe bNaX':xEu
...(n) (However, the definitions of x, x', a, b and

The above mixture operation is carried out, for example, in the form of a suspension. Then, by removing water from the suspension of this phosphor raw material mixture, a solid dry mixture is obtained. This moisture removal operation is preferably carried out at room temperature or at a not very high temperature (for example, 200°C or less) by drying under reduced pressure, vacuum drying, or both.Of course, the mixing operation is limited to the above methods. Not.

Next, the obtained dry mixture is finely pulverized, and the pulverized product is filled into a heat-resistant container such as a quartz port or an alumina crucible, and fired in an electric furnace. The firing temperature is 5
A temperature in the range of 00 to 1300° C. is appropriate, and the firing time varies depending on the amount of the phosphor raw material mixture filled and the firing temperature, but in general, 0.5 to 6 hours is appropriate. As the firing atmosphere, a weakly reducing atmosphere such as a nitrogen gas atmosphere containing a small amount of hydrogen gas or a carbon dioxide atmosphere containing -carbon oxide is used. When the europium compound used contains trivalent europium, the weakly reducing atmosphere reduces the trivalent europium to divalent europium during the firing process.

Note that a method may be used in which the phosphor raw material mixture is once fired under the above firing conditions, and then the fired product is left to cool, pulverized, and further fired (secondary firing).
500 to 800℃ under the above-mentioned weak reducing atmosphere or neutral atmosphere such as nitrogen gas atmosphere or argon gas atmosphere.
The firing is carried out at a firing temperature of 0.5 to 12 hours.

The phosphor of the present invention in powder form is obtained by the above baking.

Note that the obtained powdered male phosphor may be further subjected to various general operations in the production of phosphors, such as washing, drying, and sieving, as necessary.

In addition, when the phosphor composition of the present invention contains the above-mentioned additive components, the additive components are added at the time of weighing and mixing the phosphor raw materials or before firing.

By utilizing the manufacturing method described above, a divalent europium-activated fluorohalide/helium-based phosphor represented by the above-mentioned compositional formula (I) can be obtained. .

Next, the radiation image conversion panel of the present invention will be explained.

The radiation image conversion panel of the present invention basically comprises a support,
A phosphor layer is provided thereon, and the phosphor layer is made of a binder containing and supporting a stimulable phosphor in a dispersed state. The phosphor layer is, for example,
It can be formed on the support by the following method.

1. First, particles of the stimulable phosphor represented by the above composition formula (I) and a binder were added to a suitable solvent, and the mixture was thoroughly mixed 1 so that the phosphor particles were evenly dispersed in the binder solution. Prepare coating solution.

Examples of binders for the phosphor layer include proteins such as gelatin, polysaccharides such as dextran, or natural polymeric substances such as gum arabic: and polyvinyl butyral, polyvinyl acetate, nitrocellulose, ethylcellulose, vinylidene chloride. - Binders represented by synthetic polymeric materials such as vinyl chloride copolymers, polyalkyl (meth)acrylates, vinyl chloride/vinyl acetate copolymers, polyurethanes, cellulose acetate butyrate, polyvinyl alcohol, linear polyesters, etc. can. Particularly preferred among such binders are nitrocellulose, linear polyesters, polyalkyl (meth)acrylates, mixtures of nitrocellulose and linear polyesters, and mixtures of nitrocellulose and polyalkyl (meth)acrylates. be.

Note that these binders may be crosslinked with a crosslinking agent.

Examples of solvents for preparing coating solutions include lower alcohols such as methanol, ethanol, n-propanol, and n-butanol; chlorine-containing hydrocarbons such as methylene chloride and ethylene chloride; acetone, methyl ethyl ketone, and methyl isobutyl ketone. Ketones; esters of lower fatty acids and lower alcohols such as methyl acetate, ethyl acetate, and butyl acetate; ethers such as dioxane, ethylene glycol monoethyl ether, and ethylene glycol monomethyl ether; and mixtures thereof.

The mixing ratio of the binder and phosphor in the coating solution varies depending on the characteristics of the intended radiation image conversion panel, the type of phosphor, etc., but in general, the mixing ratio of the binder and phosphor is
It is selected from the range of 1:1 to 1:100 (weight ratio), and is particularly preferably selected from the range of 188 to 1:40 (ITE weight ratio).

The coating liquid also contains a dispersant for improving the dispersibility of the phosphor particles in the coating liquid.

Various additives such as plasticizers may be mixed to improve the bonding strength between the binder and the phosphor particles in the phosphor layer after formation, and are used for such purposes. Examples of dispersants include □, phthalic acid, stearic acid, caproic acid, and lipophilic surfactants. Examples of additives include phosphoric acid esters such as triphenyl phosphate, tricresyl phosphate, and diphenyl phosphate; phthalic acid esters such as diethyl phthalate and dimethoxyethyl phthalate; ethyl phthalylethyl glycolate, butylphthalyl glycolate, Glycolic acid esters such as rubutyl; and polyesters of triethylene glycol and adipic acid, diethylene glycol? Examples include polyesters of polyethylene glycol and aliphatic dibasic acids, such as polyesters of coal and succinic acid.

The coating solution containing the phosphor particles and binder prepared as described above is first uniformly applied to the surface of the support to form a coating film of the coating solution. This application operation is 1
This can be carried out by using conventional coating means such as a doctor blade, roll coater, knife coater, etc.

After the coating film is formed, the coating film is dried to complete the formation of the fluorescent single layer on the support. The layer thickness of the phosphor layer varies depending on the characteristics of the intended radiation image conversion panel, the type of phosphor, the mixing ratio of the binder and the phosphor, etc., but is usually 20 pm to 1 m.
Let it be m. However, this layer thickness is 50 to 500 IL
It is preferable to set it to m.

In addition, the phosphor layer does not necessarily need to be formed by directly applying a coating liquid onto a support as described above; for example, it is possible to separately apply a coating liquid onto a glass plate, metal plate, plastic sheet, etc. or onto a sheet. After the phosphor layer is formed by drying, it may be pressed onto the support, or the support and the phosphor layer may be bonded together using an adhesive.

Note that the phosphor layer may be one layer, or two or more layers may be laminated, and in the case of lamination, at least one of the layers is the above-mentioned divalent europium activated fluoride halogenated layer/,
Any layer containing a lithium-based phosphor may be used. Also, in both a single layer and a laminated layer, another type of stimulable phosphor can be used together with the above phosphor.

The support material may be any one of various materials used as supports for intensifying screens in conventional radiography or various materials known as supports for radiation image conversion panels.
You can choose. Examples of such materials include films of plastic substances such as cellulose acetate, polyester, polyethylene terephthalate, polyamide, polyimide, triacetate, polycarbonate, metal sheets such as aluminum foil, aluminum alloy foil, regular paper, baryta paper, Examples include resin coated paper, black paper, pigment paper containing pigments such as titanium dioxide, and paper sized with polyvinyl alcohol. However, 1. Considering the characteristics and handling of the radiation image storage panel as an information recording material, a particularly preferred material for the support in the present invention is a plastic film.

This plastic film may be kneaded with a light-absorbing substance such as carbon black, or may be kneaded with a light-reflecting substance such as titanium dioxide.The former is a highly sensitive type of radiation image converter. The latter is a suitable support for radiation image storage panels of high sensitivity type.

In known radiation image conversion panels, a phosphor layer is provided in order to strengthen the bond between the support and the phosphor layer, or to improve the sensitivity or image quality (sharpness, granularity) of the radiation image conversion panel. A polymeric substance such as gelatin is coated on the surface of the support on the side to be coated to form an adhesion imparting layer, or a light reflective layer made of a light reflective substance such as titanium dioxide, or a light absorbing substance such as carbon black. The support used in the present invention can also be provided with a light-absorbing layer.The support used in the present invention can also be provided with these various layers, and the structure thereof can be determined depending on the purpose and use of the desired radiation image conversion panel. can be selected arbitrarily.

Furthermore, as described in Japanese Patent Application No. 57-82431 filed by the present applicant, in order to improve the sharpness of the resulting image, the surface of the support on the phosphor layer side (the phosphor layer of the support When the surface of the layer is provided with an adhesion-imparting layer, a light-reflecting layer, a light-absorbing layer, etc., it means the surface thereof.

Fine irregularities may be formed uniformly.

In a normal radiation image storage panel, a transparent protective film is provided on the surface of the phosphor layer on the side opposite to the side that contacts the support to physically and chemically protect the phosphor layer. . Such a transparent protective film is also preferably provided for the radiation image conversion panel of the present invention.

・The transparent protective film can be made of, for example, cellulose derivatives such as cellulose acetate or nidotetracellulose: polymethyl methacrylate, polyvinyl butyl, polyvinyl formal, polycarbonate, polyvinyl acetate: vinyl chloride, vinyl acetate. It can be formed by dissolving a transparent polymeric material such as a synthetic polymeric material such as a copolymer in a suitable medium and applying a solution prepared on the surface of the phosphor layer. Alternatively, it can also be shaped by a method such as adhering it to the surface of a transparent thin wisteria phosphor layer separately formed from polyethylene terephthalate, polyethylene, polyvinylidene chloride, polyamide, etc. using a self-adhesive adhesive. It comes out. It is desirable that the thickness i of the transparent protective M film formed in this manner be approximately 3 to 26 #Lm.

In addition, JP-A-55-163500, JP-A-57-
As described in Japanese Patent No. 96300, etc., the radiation image conversion panel of the present invention may be colored with a coloring agent, and the sharpness of the image obtained can be improved by coloring. Furthermore, as described in JP-A No. 55-146447, the radiation image storage panel of the present invention may have white powder dispersed in its phosphor layer for the same purpose. , describes implementation of the present invention and comparative examples. However, each side of the crown does not limit the present invention.' □ [Example 1] 175.34 g of barium fluoride (BaF2), 333.18 g of barium bromide (BaB r2-2H20), and 0.783 g of U]lobium bromide (E uBr3) were added to 500 cc of distilled water (H2O) and mixed to form a suspension. The rice suspension was dried under reduced pressure at 60°C for 3 hours, and then further vacuum-dried at 150°C for 3 hours. After finely pulverizing the dried product using a mortar, 0.83 g of calcium bromide (CaBr2) and 1 g of sodium bromide (N aB'r) were added to 100 g of the pulverized product, and mixed to homogeneate. It was made into a mixture.

Next, the obtained phosphor raw material mixture was filled into an alumina crucible, which was then placed in a high-temperature electric furnace and fired. Calcination was carried out at 900 °C in a carbon dioxide atmosphere containing -carbon oxide.
It was carried out for 1.5 hours at a temperature of .degree. After the firing was completed, the fired product was taken out of the furnace and cooled. The obtained fired product is pulverized to obtain a powdery divalent europium-activated barium fluoride bromide phosphor [(Bao, 99+Cao, Ohu) F
Br-0,0023N a Br: 0.001
E u ”] was obtained.

In addition, by changing the amount of calcium bromide added in the range of 10-4 to 10-1 per mole of BaFBr in the production of the above phosphor, various divalent europium activated fluoride odors with different calcium contents can be produced. A barium chloride-based phosphor was obtained.

Next, various radiation image conversion panels were manufactured using the obtained various phosphors in the following manner.

``Methyl ethyl ketone was added to a mixture of phosphor particles and linear polyester resin, and nitrocellulose with a degree of nitrification of 11.5% was added to prepare a dispersion containing phosphor particles in a dispersed state.This dispersion liquid After adding tricresyl phosphate, n]butanol, and methyl ethyl ketone to the solution, the mixture is sufficiently stirred and mixed using a propeller mixer to ensure that the phosphor particles are uniformly dispersed and that the mixing ratio of the binder and the phosphor particles is 1:1. 20, viscosity is 25-35PS (2
5°C) coating solution was prepared.

This coating solution was applied to a titanium dioxide-mixed polyethylene terephthalate sheet (support material,
Thickness: 250 ILm) was coated uniformly using a doctor blade. After coating, the support on which the coating film has been formed is placed in a dryer, and the temperature inside the dryer is set to 25°C.
The coating film was dried by gradually raising the temperature from °C to 100 °C. In this way, a layer thickness of 2'OOp is applied on the support with a trowel.
, m phosphor layer was formed.

Then, a transparent film of polyethylene terephthalate (thickness: 121 Lm, coated with a polyester adhesive) was placed on top of this phosphor layer with the adhesive layer side facing down and adhered to the transparent film. A film was formed to produce a radiation image storage panel consisting of a support, a phosphor layer and a transparent protective film.

[Comparative Example 1] In Example I, by performing the same operation as in Example 1 except that calcium bromide was not added to the pulverized product, divalent europium-activated barium fluoride bromide was prepared in powder form. System heroic body (BaFJ3r・0.0023N a B
r: 0.001 E u”) was obtained.

Using the obtained phosphor particles, a radiation image storage panel consisting of a support, a phosphor layer, and a transparent IF film was manufactured in the same manner as in Example 1.

Next, each of the obtained radiation image conversion panels was evaluated by the sensitivity test and photostimulation afterglow characteristic test described below.

(1) Sensitivity test After irradiating the radiation image conversion panel with X-rays with a tube voltage of 80 KVP, the H-e-Ne laser beam (wavelength: 63.2, .8
The sensitivity was measured when excited at 5 nm).

(2) Stimulation afterglow characteristic test A test piece prepared by cutting a radiation image conversion panel into 7 cm diameter was irradiated with X beam at a tube voltage of 80 KVp, and then a He-Ne laser beam ( Wavelength: 632, 8
The blue attenuation of the stimulated afterglow was measured when the sample was scanned once with a scan time of 5 x 10-'' seconds.

The results obtained are summarized and shown in graph form in FIGS. 1 and 2.

FIG. 1 is a graph in which time is plotted on the horizontal axis and [stimulated afterglow amount/stimulated luminescence amount] is plotted on the vertical axis.

Dotted line: (Bao-sp*cao, o*)FBr*0.
0023N a B r :0.00! Radiation image conversion panel containing E u 2+ phosphor Solid line = B a F B , r ・O, 0Q23N a
B r: Radiation image conversion spring I7 containing 0.0QIEu2+ phosphor In Fig. 2, solid line: the horizontal axis shows the calcium content (a value), and the vertical axis shows [stimulated afterglow amount/stimulated luminescence amount] ] Graph dotted line: Calcium content (a value) is plotted on the horizontal axis, and relative sensitivity is plotted on the vertical axis. In addition, the amount of photostimulated afterglow is 2X after laser light irradiation.
The amount at 10-3 seconds was taken as the measured value.

[Example 2] In Example 1, 0 g of calcium bromide was added to 100 g of the pulverized material.
．． Powdered divalent-robium-activated fluoride was prepared by carrying out the same procedure as in Example 1, except that 0.15 g of silicon dioxide (SiOz) was added together with 83 g of sodium bromide and 0.1 g of sodium bromide. Barium bromide-based phosphor [(B
ao, s s + Cao.

0 1) FB r ・ 0.0023NaBr l+
o, ooes to 2:0.001E u ”] was obtained.

Using the obtained phosphor particles, a radiation image conversion panel consisting of a support, a phosphor layer, and a transparent protective film was manufactured in the same manner as in Example 1.

Next, the obtained radiation image conversion panel was evaluated by the above-mentioned sensitivity test and photostimulation afterglow characteristic test.

As a result, BaFB r−0,0023NaBr r
: Relative sensitivity and log of radiation image conversion panel of Comparative Example 1 containing 0.001Eu phosphor [stimulated afterglow amount/
The amounts of stimulated luminescence] were 0.9 and -2,9, respectively (see Figure 2), whereas (Ba□, ss+Ca o
, 01) F B r e 0.0023N a
B r e O,00BS I O,z :0.001
The relative sensitivity and log [stimulated afterglow amount/stimulated luminescence amount] of the radiation image conversion panel containing the Eu'' phosphor were 1.1 and -3.5, respectively.

[Example 3] Powder was prepared by performing the same operation as in Example 1 except that 0.33 g of calcium fluoride (CaFz) was added instead of 0.83 g of calcium bromide in Example 1. divalent europium-activated barium fluoride bromide phosphor [(Bao, s9, Ca□, 01) FB
r a O,0023N aB r:0,001E u
24] was obtained.

Using the obtained phosphor particles, a radiation image conversion panel consisting of a support J phosphor layer and a transparent protective film was manufactured in the same manner as in Example 1. '・ □ □ Next, the obtained radiation image conversion panel was evaluated by the above-mentioned sensitivity test and photostimulation afterglow characteristic test.

As a result, the relative sensitivity and photostimulated afterglow characteristics of the radiation image conversion panel of this example are both (B'a
o, s s r Cao, o s) 'FB'r eO
, 0023N a B r :0.001E u & The relative sensitivity and photostimulated afterglow characteristics (see FIGS. 1 and 2) of the radiation image conversion panel containing phosphor were the same.

[Brief explanation of the drawing]

FIG. 1 shows the CIl&o,ss*Cao-
01) FB r ・0.0023N aB r :□
Radiation image storage panel containing 0.001 Eu' phosphor (dotted line) and BaFB r-0 for comparison
,0023NaBr:0.001Eu'' is a graph showing the photostimulation afterglow characteristics of different radiation image conversion panels (solid lines) containing phosphors. 'o Otori) FB rm O,0023N lh B r:
Regarding the radiation image conversion panel containing 0.001 E u 2+ phosphor, the relationship between the calcium content (a value) and the amount of photostimulated afterglow (solid line), and the relationship between the a value and relative sensitivity (dotted line). □ Patent applicant Fuji Photo Film Co., Ltd./Agent ′
: Patent Attorney Yasuo Yanagawa 1 1 1 Figure 2 Procedural Amendment ■, Display of the Case 1982 Patent Application No. 247317 2, Title of Invention Phosphor and Radiation Image Conversion Panel Using the Same 3, Person Making Amendment Case Relationship with Patent Applicant Address Name (520) Fuji Photo Film Co., Ltd. 4, Agent) 6. Number of inventions increased by amendment None 7. Subject of amendment Detailed description of the invention in the specification. 8. Contents of the amendment As shown in the attached sheet. We will amend the "Detailed Description of the Invention" column of the specification as follows. (1) Page 7, line 5 From fireflies other than the irradiation target, line 8 of the same page Detected as light emission from a group of photoparticles, → Delete (2) Page 8, line 12 Inventor → Manabu Shiga, Commissioner of the Japan Patent Office 1. Indication of the case 1981 Patent Application No. 247317 2, Name of the invention Phosphor and radiation image conversion channel using the same 3, Person making the amendment Relationship to the case Patent applicant name (520) Fuji Photo Film Co., Ltd. Company 4, Agent address: 5th floor, 8th floor, Mitsuya Yotsuya Building, 2-14 Yotsuya, Shinjuku-ku, Tokyo, Date of amendment order: Voluntary, 6. Number of inventions increased by amendment: None 7. Subject of amendment: ``Inventions'' in the description Column 8, "Detailed Description of the Invention", Contents of the Amendment As shown in Attachment 1, the "Detailed Description of the Invention" column of the specification will be amended as shown below. Note 11 Supplementary addition --- 11 Immediate m- (1) Page 19, line 15 4) Halogenation → Halogenation of 4) (2) Page 31, line 3 0 , . 83g
→ 0.43g, calcium fluoride (CaF2)O,, 17g (3) Page 31, line 15 ~ Addition of calcium bromide →
Calcium content on the same page, line 18 Add BaFBr
(a value) CBat-a, Cab) FBr (4) Page 33, line 8 Calcium bromide → Calcium bromide and calcium fluoride (5) Page 35, line 11 0.83g → 0.43g
, Calcium fluoride 0.17g (8) Page 38, line 2 (B ao, 99, Ca (B
al-a, Caa) o, o*) FBr FBr (7) Example 3 from page 3B, line 14 to page 37, line 13
Delete. Written amendment to the above procedure 1 January 28, 1985 Patent application No. 247317 2 Title of invention Phosphor and radiation conversion channel using the same 3 Relationship with the person making the amendment Patent application Person name (520) Fuji Photo Film Co., Ltd. 4, Agent address 6, 8th floor, Mitsuya Yotsuya Building, 2-14 Yotsuya, Shinjuku-ku, Tokyo, Number of inventions to be increased by amendment None 7, Subject of amendment (1) “Detailed Description of the Invention” column of the specification (2) Drawing 8, contents of amendment (1) r- on page 38, line 7 of the specification
Correct 2.9J to r-2.6J. (2) Figure 2 of the drawings attached to the application at the time of filing is replaced with Figure 2 attached here.

Claims (1)

[Claims] 10 Compositional formula (I): (Bal-a, Ca,)FXe bNaX':xEu2
+...CI) (However, X and X゛ are both C1, Br and I
at least one kind selected from the group consisting of 2, rogen, and a, b, and X are each 0 <,
≦10-1, o<b≦2.0 and 0x≦0.2). . 2゜a in the compositional formula (1,,) is 10-”≦a≦5X
The phosphor according to claim 1, characterized in that the phosphor has a numerical value in the range of 10-'≦b≦5X 1 in the 3° compositional formula (I).
The phosphor according to claim 1, wherein the phosphor has a numerical value in the range of 0-'. 4゜b in compositional formula (I) is 5XIO-'≦b≦10
The phosphor according to claim 3, wherein the phosphor has a numerical value in the range of -2. 5. The phosphor according to claim 1, wherein X in the compositional formula (I) is at least one of Br and I. The phosphor according to claim 1, wherein X' in the 6° compositional formula (I) is Br. A radiation image storage panel substantially composed of a 7° support and a stimulable phosphor layer provided thereon,
A radiation image conversion panel characterized in that the stimulable phosphor layer contains a divalent europium-activated barium fluoride halide phosphor represented by the following compositional formula (I). Compositional formula (1): % formula % () (However, both X and X'' are at least one kind of halogen selected from the group consisting of Cil, Br, and a≦lO
→, O<b≦2.0 and 0x≦0.2) 8゜a in compositional formula (I) is 10-≦a≦5X l
The radiation image conversion panel according to claim 7, characterized in that the value is in the range of 0-''. b in the 9° compositional formula (1) is 10-'≦b≦5X 1
8. The radiation image conversion panel according to claim 7, wherein the value is in the range of 0-'. 10゜b in compositional formula (I) is 5 x 10-'≦b
The radiation image conversion panel according to claim 9, characterized in that the value is in the range of ≦lO4. 11. The radiation image conversion panel according to claim 7, wherein X in the compositional formula (I) is at least one of Br and I. 8. The radiation image storage panel according to claim 7, wherein X' in the 12° compositional formula (I) is Br.