JPS6013299A - Radiation picture converting panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a radiation image conversion panel, and more particularly, it has a stimulable phosphor layer formed by dispersing a stimulable phosphor in a binder. The present invention relates to a radiation image conversion panel in which a binder contains polyvinyl acecool resin to improve amphoscopic properties and mechanical properties.

Background Art Radiographic images such as X-ray images are often used for disease diagnosis. In order to obtain this X-ray image, the X-rays that have passed through the object are irradiated onto the phosphor layer, thereby producing visible light, and this visible light is then used with silver salt in the same way as when taking photographs of commercial products. A so-called radiograph is used, which is obtained by irradiating and developing a film J. However, in recent years, due to problems such as the depletion of silver sources, which are extremely common on a global scale, methods have been devised to extract images directly from the phosphor layer without using a film coated with silver salt. .

In this method, the radiation that has passed through the subject is absorbed by a phosphor, and then this phosphor is excited with light or thermal energy, so that the phosphor retains the radiation that has been absorbed by the phosphor. There is a method in which energy is emitted as fluorescent light, and this fluorescent light is detected and imaged. Specifically, for example, U.S. Pat. ing. This method uses a radiation image conversion panel in which a photostimulable phosphor layer is formed on a support. A latent image is formed by accumulating radiation energy corresponding to the radiation transmittance of each part, and then the accumulated radiation energy of each part is emitted by scanning this photostimulable phosphor layer with photostimulation excitation light. This is converted into light, and an image is obtained using an optical signal based on the intensity of this light. This final image may be reproduced as a hard copy or on a CRT.

By the way, the radiation image conversion panel described above uses a flexible material such as a plastic film as a support, and a stimulable phosphor layer is formed by dispersing a stimulable phosphor in a binder. It has been established. A protective layer is provided on the surface of the stimulable phosphor layer to physically or chemically protect it, and if necessary, a protective layer is provided between the stimulable phosphor layer and the support. A pulling layer is provided to improve the adhesion between the two.

When a radiation image conversion panel having a configuration such as 2 is used, the radiation image recording process of accumulating radiation energy to form a latent image as described above and scanning the latent image with stimulated excitation light is performed. In the radiation image reproduction process for extracting images, they are incorporated into the imaging device and the reading device, respectively. At this time, a bending force may be applied to the radiation image conversion panel so that it is automatically sent from the imaging device to the reading device using a roller conveyor, for example. In this case, the panel will be bent during handling since the support is made of a flexible material. In particular, since this panel is reused by erasing the afterimage with strong erasing light after taking out the image, it is repeatedly loaded into the above-mentioned device. This process is repeated several thousand times. Therefore, the above-mentioned panel may be bent repeatedly. If this happens, cracks may occur in the stimulable phosphor layer, or the phosphor layer may partially peel off from the support, and such a layer may be used as a phosphor layer. If used, images corresponding to these parts will be accompanied by noise. In order to prevent cracking or peeling from occurring due to such bending, the stimulable phosphor layer should have flexibility and strong adhesion to the support. However, regarding this flexibility, if this is too large,
When the radiographic image conversion panel is repeatedly used, pressure or other local forces may be applied to the support and other parts when it is incorporated into the device, for example, when it is mounted, supported on a frame, or transported by rollers, etc. It is easy to attach, so it must be moderate.

Furthermore, as mentioned above, the radiation image conversion panel is irradiated with stimulated excitation light during reading in the radiation image reproduction process, and is also irradiated with erasing light for erasing afterimages for reuse. 106 to 108 Lux-sec is irradiated. Read like this b l'B! This excitation light and the much more powerful erasure light are exposed to the photostimulable phosphor layer over a long period of time, for example, several thousand times! (1) Since the binder is usually an organic abrasive, it may photodecompose and become yellowed.In this case, for example, fluorescent light generated from a stimulable phosphor If the line has a spectrum with a peak at 3901 m and a half-width of 360 to 410 nm, it overlaps with the absorption region of the binder, so fluorescent Xtf
, -a1) is absorbed by this binder. Furthermore, similar problems arise when using stimulated excitation light that is close to the absorption region of the binder. When the binder absorbs one or both of the photostimulable excitation light and the light generated from the photostimulable phosphor in this manner, the reading sensitivity of the radiation image conversion panel is reduced. As a result, the binder undergoes light change &J
As a result, the binder becomes hard, reducing the flexibility of the stimulable phosphor layer and its adhesion to the support.

The binder used in the stimulable phosphor layer of the radiation image conversion panel has properties such as durability and light resistance, such as resistance to cracking, adhesion and scratch resistance. Excellent properties are required in this respect. This property is much stricter than the properties required of a binder used in the phosphor layer of a general phosphor intensifying screen. In the case of a general phosphor intensifying screen, it is used by pasting it on a cassette, and the phosphor layer does not need to be particularly flexible against bending or be careful not to get scratched as mentioned above. Also, the above-mentioned light resistance is not required.

As the binder for the stimulable phosphor layer of the radiation image conversion panel as described above, binders that have been used in the phosphor layer of general phosphor intensifying screens may be used. things are being done. Examples of binders used in such general phosphor intensifying screens include those disclosed in Japanese Patent No. 163500/1982;
As described in JP-A-56-11400, proteins such as gelatin, polysancalides such as dextrin or cellulose derivatives such as gum arabic, polyvinyl acecool, nitrocellulose, vinyl chloride, etc.
Vinylidene chloride copolymer, polymethyl methacrylate, vinyl chloride-vinyl acetate copolymer, polyurethane,
Examples include polyvinyl acetate and polyvinyl alcohol. However, these binders do not have the durability and light resistance required for the binders of the stimulable phosphor layers of radiation image conversion panels as described above. For example, in the case of nitrocellulose, it is easily yellowed by the excitation light and erasing light, and it does not have the flexibility and adhesive properties mentioned above, so it cannot withstand use, and polyvinyl alcohol has insufficient water resistance. '', the durability is also insufficient. The properties required of polyvinyl acecool, which are listed on the same level as those with poor light resistance and water resistance, are also required of the binder for the phosphor layer of general phosphor intensifying screens. It is nothing more than nature. Therefore, among the products collectively called polyvinyl acecool, those with insufficient water resistance due to their high vinylalnylene content cannot withstand use as a binder for the stimulable phosphor layer, just like polyvinyl alcohol. do not have. In this way, polyvinyl acetal can be used as a binder for the phosphor layer of general phosphor intensifying screens, but it cannot also be used as a binder for the stimulable phosphor layer. In order for Acecool to be usable as a binder for the stimulable phosphor layer, special consideration is required, but the polyvinyl acetal exemplified above does not give any suggestion regarding these matters. However, it is difficult to derive polyvinyl acecool having sufficient durability as a binder for a stimulable phosphor layer from the polyvinyl acecool in the above-mentioned range. On the other hand, JP-A-57-24900 discloses a radiation conversion panel using a mixture of polyester-urethane resin and cellulose acetate as a binder for the purpose of improving the above-mentioned durability against bending and light resistance. . However, among the resins contained in the binder of this radiation image conversion panel, cellulose acetate has particularly poor light resistance, resulting in yellowing, which causes the deterioration of sensitivity as described above, and the resulting sensitivity unevenness. It has the following drawback.

As mentioned above, the durability and light resistance of the binder in the stimulable phosphor layer of the conventional radiation image conversion panel are insufficient, and improvement thereof has been desired.

OBJECTS OF THE INVENTION The first object of the present invention is that the photostimulable phosphor layer has good light resistance to photostimulation excitation light and erasure light, and therefore has good sensitivity even when repeatedly irradiated with these lights for a long time. decrease or
Another object of the present invention is to provide a radiation image conversion panel whose durability against bending does not deteriorate due to hardening of the binder.

A second object of the present invention is to provide a photostimulable phosphor IH with respect to bending.
cracks or the stimulable phosphor layer peels off from the support! There is a need to provide a radiographic image conversion panel that does not require If.

A third object of the present invention is to provide a radiation image conversion panel in which the stimulable phosphor layer is less likely to be damaged by pressure or other factors during use, and is therefore easy to handle.

Structure of the Invention The above-mentioned object is to provide a binder for a stimulable phosphor layer of a radiation image conversion panel that has light resistance and has an arbitrary flexibility between, for example, nitrocellulose, cellulose acetate, and polyurethane resin. This is accomplished by using a range of polyvinyl acecool resins.

The radiation image conversion panel of the present invention is a radiation image conversion panel having a support and a photostimulable phosphor layer formed by dispersing a photostimulable phosphor in a binder. It is characterized by containing a polyvinyl acecool resin represented by the formula.

(In the formula, R represents a lower alkyl group, and x, y and 2 are 0.40<x/(x-1-y+z)<
0.790.20< y/ (x + y + z)
<0.54g <z / (x + y + z) <0
．． 20 and 100 < x + y + z < 3000 and is an integer. ) The present invention will be described in detail below.

Polyvinyl acecool 161 resin, which is a binder used in the stimulable phosphor layer of the radiation image conversion panel of the present invention, is represented by the above general formula.

Polyvinyl acecool resin is generally synthesized by reacting aldehyde with polyvinyl alcohol obtained by saponifying polyvinyl acetate.
It is a copolymer of vinyl alcohol and vinyl acetate, and its properties vary significantly depending on the proportions of these components. In other words, when the vinyl acetal component is increased, the /8PJ resistance against ordinary solvents, water resistance, and heat softening properties are improved, and when the vinyl alcohol component is increased, the water resistance is decreased. , and when the vinyl acetate component is increased, the
B: Degradability and water resistance are improved, but adhesive strength to the support and light resistance are reduced. Therefore, when using polyvinyl acecool resin as a binder for the stimulable phosphor of a radiation image conversion panel, the ratio of the above three components is extremely important.
The performance of the stimulable phosphor layer varies considerably depending on this ratio.

Since the properties of the stimulable phosphor layer vary depending on the proportions of the three components, the polyvinyl acecool resin used in the present invention can be selected from the following ranges to achieve the above-mentioned durability. and can improve light resistance.

That is, in the above general formula, the ratio of the vinyl acetal component is 0.40<x/(x+y-tz)<0.7
9 is preferred. This is because when the proportion of vinyl acecool component decreases and x/(x+y +z)<0.40,
As a result, the vinyl alcohol component or vinyl acetate component increases, and when the vinyl alcohol component increases, the hydrophilicity of the polyvinyl acecool resin of these copolymers increases, and this increases the above-mentioned stimulable fluorescence. When used as a binder for a body layer, its water resistance is significantly reduced, causing the stimulable phosphor layer containing the binder to swell in high humidity.
This is undesirable because it causes a decrease in adhesiveness with the support and makes scratches more likely to occur, and also because the solubility of this polyvinyl acecool resin in organic solvents decreases, so the presence of stimulable fluorescence in this resin solution is undesirable. This is because it is difficult to prepare a dispersion liquid with good coating properties using molecules of photogen, and it is therefore impossible to coat and form a stimulable phosphor layer on a support. On the other hand, when the proportion of vinyl acetate component increases, the adhesive strength or light resistance of polyvinyl acecool resin to the support material decreases significantly, and when this resin is used as a binder for the above-mentioned stimulable phosphor layer, This is because the durability against bending or the one-plane optical property against photostimulation excitation light and erasure light is reduced. In addition, the vinyl acecool component increases, and when x / (x + y + z) > 0.79, the synthesis yield of the polyvinyl acecool resin becomes poor, and it is difficult to use it as a binder for the stimulable phosphor layer. This is because it would be industrially disadvantageous to do so.

In addition, the ratio of vinyl alcohol component is 0.20<y/
(xy+z)<0.54 is preferable. This is due to the increase in the proportion of vinyl alcohol component, y/
If (x 10y'+z)'>0.54, as mentioned above, the hydrophilicity of the polyvinyl acecool resin increases, which is undesirable, and the proportion of the pure alcohol component decreases, resulting in a ratio of 0.54.
This is because when 20>y/ (x+y+z), the synthesis yield of the polyvinyl acecool resin becomes poor, and as described above, it is disadvantageous as a binder for the stimulable phosphor layer.

In addition, regarding the proportion of vinyl acetate component, 0 <
z/(x+y+z)<0.20 is preferable.

This is because, as the proportion of the hahinylacetate component increases, when z/(x+y+z)>0.20, the adhesive strength or light resistance of the polyvinyl acecool resin to the support decreases as described above, which is not preferable.

The object of the present invention can be achieved by using a polyvinyl acecool resin in which the ratio of each component is selected from the above range as a binder for the photostimulable phosphor layer. Considering the dispersibility in the binder, the ease of application when forming the stimulable phosphor layer, etc., the above polyvinyl acecool resin should be selected from the range shown below. It is more preferable to select. That is, the proportions of the vinyl acecool component, vinyl alcohol component, and vinyl acetate component are each 0.44<x/(x + y
+ z) <0.75, (1,22< y/(x
+ y + z ) <0.50 and O〈z / (x
It is more preferable that 4-y71-z) <O, 1,5.

Furthermore, if the photostimulable phosphor layer is easily deteriorated by moisture, it is necessary to reduce the moisture permeability of the photostimulable phosphor layer, and for this purpose, the polyvinyl acecool resin should be within the range shown below. It is more preferable to select from. That is, the vinyl acecool component, vinyl alcohol component, and vinyl acetate component are each 0.50<x/(
x+y+z)<0.75.0.25<y/(x+
y + z ) <0.45 and 0<Z/ (x+y
It is even more preferable that 4-z)<0.15.

In the polyvinyl acetal resin used in the present invention, in addition to the above-mentioned proportions of each component, R is a lower alkyl group, and the lower alkyl group has 1 to 8 carbon atoms.
Examples include: As the number of carbon atoms in R increases, the glass transition temperature of polyvinyl acecool resin tends to decrease.In order to keep the glass transition temperature moderate and the flexibility of the resin good, the number of carbon atoms in R should be increased from 1 to 4. More preferred. For example, when comparing polyvinyl hexanal resin in which R is a hexyl group and polyvinyl butyral resin in which R is a butyl group, polyvinyl butyral resin has superior flexibility and adhesion to commonly used plastic supports. Polyvinyl butyral resin in which R is a butyl group is most preferred.

The degree of polymerization of polyvinyl acecool resin (x + y + 2) is 1
When used as a binder for the stimulable phosphor layer, the degree of polymerization is between 150 and 3000 in terms of the bending strength or the softening point of the resin, which indicates its flexibility. 2000 is more preferable.

The binder used in the stimulable phosphor layer of the radiation image conversion panel of the present invention may be polyvinyl acecool resin, but other binders having excellent compatibility with polyvinyl acecool resin may be used. Alternatively, it may be used in combination with two or more resins. Examples of such resins include phenol 4A+ resin, melamine resin, epoxy resin, 7-leic acid resin, alkyd resin, ester gum, sulfomenamide resin, and nitrocellulose. The flexibility of the stimulable phosphor layer can also be improved by using these other resins together as a binder. These resins and the polyvinyl acecool resin used in the present invention can be obtained by mixing their respective resin solutions and applying and drying the mixed solution (M), but by changing the mixing ratio of these resins, When used in a photostimulable phosphor layer, the physical properties such as flexibility can be changed to provide the best physical properties for the photostimulable phosphor layer. Physical 11 as a photostimulable phosphor layer in an image conversion panel
As a particularly preferable 'l' property, the ratio of the polyvinyl acecool resin used in the present invention to the other resins mentioned above is 4:6 (weight ratio) or more, particularly 6:4 or more. Examples include those that use a lot of. To manufacture the radiation image conversion panel of the present invention, first, a photostimulable phosphor described below is dispersed in a suitable organic solvent to prepare a dispersion of the photostimulable phosphor. Examples of organic solvents for this purpose include alcohols such as methanol, ethanol, and n-propanol; chlorinated hydrocarbons such as methylene chloride and ethylene chloride; ketones such as acetone and methyl ethyl ketone; and methyl acetate, ethyl acetate, and butyl acetate. Examples include, but are not limited to, esters, dioxane, ethers such as ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, and mixtures thereof.

Next, a polyvinyl acecool resin solution prepared in advance is added to the above-mentioned photostimulable phosphor dispersion liquid, and the coating liquid is prepared by dispersing and mixing using a ball mill, impeller mill, roll mill, glass beads, ultrasonic disperser, etc. Manufactured by +tJtil. The solvent for dissolving the polyvinyl acecool resin is as follows:
Examples include, but are not limited to, alcohols such as methanol, ethanol, hensyl alcohol, and n-propanol, ketones such as acetone and methyl ethyl ketone, ethers such as dioxane, ethylene glycol monoethyl ether, and ethylene glycol monomethyl ether, and mixtures thereof. It is not something that will be done. In addition, when using the polyvinyl acecool resin and another resin together, the other resin solution may be made of steel, and this may be added to the above-mentioned dispersion liquid together with the polyvinyl acecool resin solution, and the same operation as above may be performed.

The mixing ratio of the resin and the stimulable phosphor in the coating solution varies depending on the characteristics required depending on the intended use of the radiation image conversion panel, the type of the stimulable phosphor, etc., but is generally 1. :
selected from the range of 1 to 1:30 (weight ratio), 1:
The range of 5 to 1:20 (Mit ratio) is more preferable.

Note that a dispersant may be added to the coating liquid for the purpose of improving the dispersibility of the photostimulable phosphor particles.

Such dispersants include phthalic acid, stearic acid,
Caproic acid, lipophilic surfactants, etc. are used. Also,
When the coating liquid is applied and dried to form a photostimulable phosphor layer, a plasticizer is added to the coating liquid in order to improve the binding force between the binder made of resin and the photostimulable phosphor particles. may be added. Such plasticizers include phosphate esters such as triphenyl phosphate and diphenyl phosphate;
Glycolic acid esters such as diethyl phthalate, ethyl phthalyl ethyl glycolate, butyl phthalyl glycolate, and the like are used.

・Furthermore, in order to increase the sharpness of the image formed on the radiation image conversion panel, for example, Japanese Patent Application Laid-Open No. 14644
White powder may be dispersed in the photostimulable phosphor layer as described in Japanese Patent Application No. 7, or
As described in Japanese Patent No. 163500, the sharpness of the image of the stimulable phosphor layer is increased by dispersing a coloring agent that absorbs the stimulable excitation light in the stimulable phosphor layer. Alternatively, it may be appropriately colored in order to absorb photostimulating excitation light. Examples of such n-color agents include Cyanine Blue BNR5 (manufactured by Toyo Ink) and Lionol Blue SL.
(manufactured by Toyo Ink), Sumia Acrylic Blue F-GSL
(manufactured by Sumitomo Chemical) etc. are given.

To form a photostimulable phosphor layer using the coating solution described in Section 2,
This coating solution is uniformly applied to a support using a doctor blade, roll coater, knife coater, etc., and dried by an appropriate means to form a coating film. The above-mentioned supports include general paper and baryta paper, resin, Tl-1 paper, bigmen containing pigments such as titanium dioxide, processed paper such as 1 (Me), sized polyvinyl alcohol, etc., polyethylene, A sheet 1 made of polyester such as polypropylene, polyethylene terephthalate, or other polymeric material, a metal sheet such as an aluminum plate, an iron plate, a copper plate, etc. are used.The surface of the support to which the coating liquid is applied is preliminarily coated with gelatin, etc. In addition, in order to improve the sharpness of the image of the radiation image conversion panel, the support or the undercoat layer may be provided as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 55'-163500. The pulling layer may be colored.Furthermore, in order to improve the sharpness and sensitivity of this radiation image conversion panel, the support and the stimulable phosphor layer may be colored as disclosed in Japanese Patent Application Laid-Open No. 11393/1983. A light reflecting layer may be provided between the two.

The thickness of the stimulable phosphor layer formed by coating and drying the above coating solution depends on the characteristics of the radiation image conversion panel, the type of stimulable phosphor, the binder and the stimulable phosphor layer. It varies depending on the mixing ratio of the light source, etc., but generally it is 10μm to 100μm.
0 μm is suitable, preferably 80 μm to 600 μm.
It is μm.

The photostimulable phosphor layer formed as described above can be used as is, but generally a protective layer is provided on the surface of the photostimulable phosphor layer (the surface opposite to the support side). The fluorescent phosphor layer is physically and chemically protected. This protective layer contains cellulose derivatives such as cellulose acetate and nitrocellulose,
Polymethyl methacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, vinyl acetate,
Examples include those obtained by dissolving a resin such as vinyl chloride-vinyl acetate copolymer or polyester in a suitable solvent, applying the solution to the above-mentioned stimulable phosphor layer and drying it. Further, a thin film of polyethylene terephthalate, polyester, polyvinyl butyral, polyvinyl formal, polyethylene, vinylidene chloride, nylon, or the like may be adhered to the surface of the stimulable phosphor layer with a suitable adhesive. The thickness of HogiH is 2-4
The protective layer preferably has a thickness of about 0 μm. Similarly to the binder used in the photostimulable phosphor layer, the protective layer is preferably one that is less susceptible to deterioration due to photostimulation excitation light and erasing light. From this point of view, polymethyl methacrylate, polymethyl methacrylate, Particularly preferred are polyvinyl butyral, polyvinyl formal, polyester, nylon, polyethylene, polyethylene terephthalate, and the like.

Here, regarding the photostimulable phosphor used in the present invention, i'
rniji <describe. As mentioned above, when irradiated with radiation and then irradiated with stimulable excitation light, the stimulable phosphor can be
It is a phosphor that emits stimulated light, but from a practical point of view, it is preferably a phosphor that emits stimulated light with stimulated excitation light of 500 to 800 nm. An example of such a photostimulable phosphor is BaSO4:Ax (wherein 8 is Dy), which is described in JP-A No. 48-80487.

is at least one of Tb and Tm, and X is 0
．． 001≦x<1 mol%. ), MgSO4:Δχ as described in JP-A-48-80488 (where 8 is at least one of HO and Dy, and X is 0.001≦×≦ Fluorescent material represented by 1 mol % '), JP-A-48-1989 #, 04
SrSO4 described in Publication No. 89: Ax (however, 8 is Dy).

At least 1#r of Tb and Tm, and Xba0
．． 001≦X<1 mol%. ), a phosphor represented by
A phosphor in which at least one of Mn, Dy and Tb is added to 2SO4°Ca504, Ba504, etc., Bed, L described in JP-A-52-30487.
IF + , phosphors such as Mg504 and CaF2, L as described in JP-A-53-39277;
i2 B40. : Fluorescent material such as CuAg, JP-A-54-4
Li2O・(B202
)x:Cu (where X is 2<X≦3), and Li2O
・(B202)x :Cu, 1g (However,
≦3) etc., SrS described in U.S. Patent No. 3,859,527: Ce, Sm
, SrS: Eu, Sm, La202S:
Eu, Sn+ and (Zn, Cd) S: Mn,
(where X is a halogen). Furthermore, the general formula of the ZnS:Cu,P6 phosphor described in JP-A No. 55-12142 is BaO.^7!203:[Eu (0.8≦X≦10). barium aluminate phosphor, and the general formula is MI[
0・xSi02:Δ (However, 1) I is Mg+Ca, S
r, Zm, Cd or Bao is Ce+Tb, Eu
Examples include alkaline earth metal silicate-based phosphors represented by +Tm, Pb, TA, Bi, and Mn (both are one type, and X is 0.5≦X≦2.5). .

Moreover, the general formula is (mouth tr 1 -x-yMgxCay) FX: e
Eu'' (where X is at least one of Br and Ce, and x, y and e each satisfy Q <X +y ≦0.
6, xyfO and 10≦e≦5×10. ), the general formula of the alkaline earth 11 fluorohalide phosphor described in JP-A-55-12144 is LnOX: xA (where Ln represents at least one of La, Y, Gd, and Lu). , X is Ca and/or Br, 8 is Ce and/or T
b, and X represents a number satisfying 0 < x <O', l. ), the general formula described in JP-A-55-12145 is (Ba 1-xMnx ) FX : yA (however, Ml
is at least one of Ma, Ca Sr, Zn and Cd, and X is at least one of cz, Br+ and I
One and eight are Eu, Tb+ Ce, Tm+ Dy+
At least one of Pr, llo, Nd, Yb and Er, X and y are 0≦X≦0.6 and O≦y≦
It represents a number that does not satisfy the condition of 0.2. ), the general formula described in JP-A-55-84389 is BaFX, Ce, yA (where X is Cj!
, Br and I, ^ is In, T1
2, Gd, Sm and Zr, and y and Q<x≦2×10−1 and Q<y≦5×10−2, respectively. ), a phosphor represented by
The general formula described in JP-A No. 55-1600078 is 1+XxΔ: yLn (however, at least one of Ba, Ca, Sr+1g, Zn, and Cd, and 8 is O+ M g O+
Ca O+ S' r O+ B a O+ Z n
O+ 81203, Y2O3, La2O3, In20
B, 5i02. TiO2, ZrO2゜GeO2, 5n0
2. Nb2O5+ At least one of Ta205 and Tho2, Ln is [iu, Tb+ Ce, Tm
, Dy+ Pr+11o, Nd, Yb, l! r
, Sm and Gd, and X and y are 5×10≦X≦0.5 and 0<y≦0., respectively.
It is a number that does not satisfy the condition of 2. ) rare earth element-activated divalent metal fluorohalide phosphor, whose general formula is Zn
S: A XCd5: 8, (Zn.

Cd) S: 8, ZnS: A, X and CdS: 8, X
(However, 8 is Cu, AH, Au or Mn, and X is halogen.

), the general formula (1) or [■] described in JP-A-57-148285, the general formula (
1) xA3 (PO4) 2 ・NX2 :V^-f
Throwing ceremony [■] lL3 (PO4) 2:V8 (in the ceremony,
■ and N are respectively M g + Ca + S r +
At least one of B a + Z n and Cd,
X is F, (1, at least one of Br and I, 8 is Eu+Tb, Ce, Tm, Dy+ pr.

flo, Nd, Yb, Er, Sb, T It
, represents at least one kind among Kn and Sn. Furthermore, X and y are numbers that do not satisfy the condition 0<x≦6.0≦y≦1. ), and a phosphor represented by the general formula (I
II) or (IV) General formula (III) nReX3・m
AX'2: xEu general formula (IVI nReX3 ・mA
X'2: xEu -ySm (wherein, Re is La, G
d, Y, and Lu, 8 represents an alkaline earth metal, and at least one of Ba + Sr + Ca, and X'' represents at least one of F, Cj2.Br. Also, X and y are 1xio-'<x
<3xlo-! 1 xlo-<y <l Xl0
It is a number that satisfies the condition -1, and n7m is 1 Xl0
-3 <n 7m <7×1σ satisfies the condition. ) and the like.

As described above, a radiation image conversion panel having a stimulable phosphor layer in which the stimulable phosphor is dispersed in a binder made of the resin on the support is completed, and these are assembled together. Stored. When using this, first the photographing device is attached to the frame. Next, for example, a human body is used as a subject, and radiation such as X-rays is irradiated onto the subject, and the transmitted light is irradiated onto the radiation image conversion panel.

As a result, a latent image is formed on the stimulable phosphor layer by absorbing the X-rays in proportion to the intensity of the X-rays corresponding to the X-ray transmittance of each part of the subject, and the latent image is recorded. Next, when the recorded latent image is read out, the radiation image conversion panel that recorded the image will be read out by a roller converter or a cassette equipped with the panel, for example, and the photostimulation excitation light will be read out. As a result, the absorbed radiation energy is emitted and fluorescence is generated based on this, and this optical signal is photoelectrically converted and converted into a visible image by appropriate means. This used item is reused. At that time, since there is an afterimage on the photostimulable phosphor layer, in order to erase this, an erasing light stronger than the above-mentioned photostimulable excitation light is applied to the photostimulable phosphor layer immediately after using the radiation image conversion panel or immediately before reuse. Irradiate the layer.

In this way, each time the radiation image conversion panel is used, it is set in the mounting frame of the imaging device, automatically sent to the reading device, and irradiated with stimulation excitation light and erasure light. At this time, the support of the radiation image conversion panel is made of a flexible material and may be bent during handling, but the binder is made of polyvinyl acecool, which has moderate flexibility.
During this handling, no mechanical cracks occur in the stimulable phosphor layer, no partial peeling occurs, and the stimulable phosphor layer is prevented from being damaged. In addition, since polyvinyl acecool resin has light resistance, it is less likely to be deteriorated by one or both of the above-mentioned photostimulation excitation light and erasure light.
Therefore, there is no absorption of the stimulated excitation light and the stimulated fluorescence generated by the photostimulable phosphor when reading out the latent image, so that the reading sensitivity of the latent image is not reduced, and the occurrence of cracks due to hardening of the resin can be reduced. There is a flexibility measurement value using the test method described below that indicates the occurrence of mechanical cracks, partial peeling, or susceptibility to scratches.
The flexibility of the radiation image conversion panel of the present invention is 0.31 to 0.
．． 62 mm/g, which is far superior to 0.11 or 0.25, respectively, when conventional nitrocellulose or cellulose acetate is used as a binder. In this way, it is possible to have the optimum characteristics (Ift) for the above requirements by changing I?, x, y, and 2 in the above general formula. This is because it can have any flexibility between nitrocellulose and cellulose acetate, which do not adhere well to the body, and polyurethane resin, which has sufficient flexibility against bending but is easily damaged. Regarding light resistance, when using the test method described below, the sensitivity ratio of the radiation image conversion panel of the present invention is 96 to 92%, and when conventional polyester-urethane-cellulose acetate or polyurethane resin is used as a binder. 80 or 6 respectively
5, and exhibits far better properties than these conventional products, which not only suffer from resin deterioration but also inevitably suffer from the occurrence of cracks due to hardening of <151 resins.

Effects of the Invention As explained below, according to the present invention, polyvinyl acecool resin is used as the binder for the stimulable phosphor layer of the radiation image conversion panel, so that the radiation image conversion Even when the panel is used repeatedly, its flexibility makes it possible to reduce cracking or peeling of the photostimulable phosphor layer from the support, and its excellent light resistance allows photostimulation to occur even when the radiation image conversion panel is used repeatedly. Even if light and erasing light are repeatedly irradiated, a decrease in the sensitivity of reading the latent image of the stimulable phosphor layer can be suppressed.

Next, the present invention will be explained in detail.

Example 1 Divalent europium-activated odorized barium fluoride stimulable phosphor (
A photostimulable phosphor dispersion was prepared by dispersing 300 parts by weight of BaFBr (Uu) in 50 parts by weight of cyclohexanone. In addition, the average degree of polymerization is 1000, x / (x
+y +z) -0,70,y/(x +y +
z ) = 0.27 and z / (x + y + z ) -〇, 30 parts by weight of polyvinyl butyral resin of 03 and 130 parts of cyclohexanone
Parts by weight of the polyvinyl butyral resin solution were melted to prepare m parts of polyvinyl butyral resin solution.

Next, the polyvinyl butyral resin solution was added to the stimulable phosphor dispersion, and 2 parts by weight of tricresyl phosphate was added as a plasticizer, and the mixture was thoroughly mixed using an ultrasonic disperser to obtain a coating solution. Ta.

Composition of coating liquid rlal'Br: IEu'' 300 parts by weight Polyvinyl butyral resin 30 parts by weight Tricresyl phosphate 2
Parts by weight Cyclohexanone 180 parts by weight This coating solution was uniformly applied onto a 250 μm thick polyethylene terephthalate plate held horizontally using a doctor blade. After coating, the coating was air-dried for a day and night, and then dried in a drying box at a temperature gradually raised from room temperature to 100°C. In this way, a 300 μm thick stimulable phosphor layer was formed on the polyethylene terephthalate support.

Next, a solution of 30 parts by weight of polymethyl methacrylate dissolved in 170 parts by weight of doluol was applied to the surface of the above-mentioned photostimulable phosphor layer, and the temperature was lowered from room temperature to 1°C in a drying box.
The temperature was gradually raised to 00° C. and dried to form a protective layer with a thickness of 8 μm.

Radiographic image conversion panel test piece A thus obtained
The flexibility measurement, cracking test, and photostimulable phosphor layer peeling test described below were carried out using the same, as well as the light resistance test against one or both of photostimulation excitation light and erasure light. The results are shown in Table 1.

In addition, in order to check the light resistance (yellowing due to deterioration of the binder) of the radiation image conversion panel, the spectral reflectance of the photostimulable phosphor layer was measured over time, and the results are shown in the figure (curve A ).

Example 2 Instead of the polyvinyl butyral resin of Example 1, the average degree of polymerization was 600, x / (x + y + z ) = 0.49y / (x
+y +Z ) -〇、47z / (x +y +
A radiation image conversion panel test piece B of this example was obtained in the same manner as in Example 1 except that a polyvinyl butyral resin of -0.04 was used.

The same measurements and tests as in Example 1 were performed using this radiation image conversion panel test piece B. The results are shown in Table 1 and the figure (curve B).

Example 3 Instead of the polyvinyl butyral resin of Example 1, the average degree of polymerization was 600, x / (x + y → -z) = 0.64 y /
(to +y +z) =0.25z / (x +y
+z) = 0.11 polyvinyl butyral resin 24
Weight parts and phenolic tree Jllj (Priauchen 50
10) The radiation ii"ii image conversion panel test piece C of this example was prepared in the same manner as in Example 1 except that 6 parts by weight was used.
I got it.

The same measurements and tests as in Example 1 were performed using this radiation image conversion panel test piece C. The results are shown in Table 1 and the figure (curve C).

Comparative examples to be compared with the radiographic image conversion panel test pieces of these Examples were prepared as follows, and the same measurements and tests as above were conducted. The results are shown in Table 1 and Figure (Curve I)
-S).

Comparative Example 1 Polyurethane resin (Nippon Polyurethane Co., Ltd.!!N-3022) was used instead of the polyvinyl butyral resin in Example 1.
A radiation image conversion panel test piece P of this comparative example was obtained in the same manner as in Example 1, except that 30 parts by weight of cyclohekira 9f was dissolved in 130 parts by weight.

Comparative Example 2 The polyvinyl butyral resin of Example 1 was replaced with 30% by weight of nitrocellulose with an average degree of polymerization of 250 and a degree of nitrification of 10%, dissolved in a mixed solvent of 80 parts by weight of methyl ethyl ketone and 50 parts by weight of ethyl acetate. A radiation image conversion panel test piece Q of this comparative example was obtained in the same manner as in Example 1.

Comparative Example 3 A methylene chloride-soluble polyester with an average molecular weight Wk of 7000 synthesized using a dihydroxy polyester at both ends consisting of adipic acid and ethylene glycol and 1-lylene diisocyanate-1 in place of the polyvinyl butyral resin of Example 1. -Polyester made by dissolving 20 parts by weight of urethane resin in 80 parts by weight of methylene chloride-
Urethane resin solution and acetylation 1.0164%, average degree of polymerization 2
Example 1 except that a cellulose acetate solution prepared by dissolving 10 parts by weight of cellulose acetate of No. 80 in a mixed solvent of 45 parts by weight of methylene chloride and 5 parts by weight of methanol was used.
In the same manner as above, a radiation image conversion panel test piece R of this comparative example was obtained.

Comparative Example 4 Example except that cellulose acetate with an average degree of polymerization of 260 and a degree of acetylation of 60% was dissolved in a mixed solvent of 110 parts by weight of methyl chloride and 20 parts by weight of methanol instead of the polyvinyl butyral resin of Example 1. A radiation image conversion panel test piece S of this comparative example was obtained in the same manner as in Example 1.

(Hereinafter, the margin of this page) From the results of the flexibility measurement and the peeling test of the photostimulable phosphor layer in the table above, the radiation image conversion panel test pieces A-C of Examples 1 to 3, and the radiation image of the comparative example. Conversion panel test piece P
, Q, and S, there is no cracking or peeling due to bending, and the durability against these is higher, and the risk of cranking due to bending during handling can be reduced. On the other hand, in all of the comparative examples, the stimulable phosphor layer was likely to peel off, and in the test specimens Q and S, cracks also occurred in the stimulable phosphor layer. Here, since the test piece P is more flexible than the one in this example, the panel is locally pressed when the radiation image conversion panel is being read and mounted and transported by rollers, so the stimulable phosphor layer It is easy to get scratches. In addition, the results of the light resistance test showed that the test pieces A-C of Examples j to 3 showed almost no decrease in sensitivity to either or both of the photostimulation excitation light and the erasure light than the test pieces P, Q, and S of the comparative examples. (It has excellent light resistance.

This is even clearer than the figure. That is, this Example 1
Test pieces A to C of ~3 show almost no decrease in reflectance to 390 μm light, whereas test pieces I) to S of comparative examples
has a large decrease in reflectance. This is the result of yellowing of the binder resin due to deterioration and absorption of fluorescence and photostimulation excitation light generated by the photostimulable phosphor. In particular, test specimens Q and S of radiation image conversion panels using nitrocellulose or cellulose acetate as a binder are almost impossible to use practically because the resin deteriorates significantly.

In addition, test pieces A to C of Examples 1 to 3 were exposed to photostimulated excitation light,
Since the deterioration of the binder due to erasing light is small, there is no difference in the crack test results before and after the light resistance test, whereas the comparative example test piece Q-3 has a difference in the crack test results before and after the light resistance test. A large difference was observed, and this is understood to be because the binder deteriorated due to the light, and the resin of the binder hardened, reducing its flexibility and becoming brittle. In particular, nitrocellulose and cellulose acetate are susceptible to cracking and cannot be put to practical use.

Example 4 Instead of the polyvinyl butyral resin of Example 1, the average degree of polymerization was 800, x, / (x + y + z ) = 0.43y / (
x + y + z ) -0,53z / (x + y
A radiographic image conversion panel test piece of this example was obtained in the same manner as in Example 1 except that a polyvinyl butyral resin with 10z) = 0.04 was used. A water resistance test was conducted using this radiation image conversion panel test piece and the radiation image conversion panel test pieces A and B obtained in Example 2. That is, the changes in appearance and changes in peel 811 test and sensitivity measurement results were investigated before and after the panel test specimens A, B, and D were stored for 20 days at a constant temperature of 50° C. and 95% relative humidity. The results are shown in Table 2.

Comparative Example 5 Instead of the polyvinyl butyral resin of Example 1, the average degree of polymerization was 80'0, x / (X + y + z ) -0,33y / (
x + V + z) = 0.63z / (x + y
+Z) =O,'04 polyvinyl butyral resin 30
A radiation image conversion panel test piece T of this comparative example was obtained in the same manner as in Example 1, except that part by weight was dissolved in 130 parts by weight of m-cresol. Using this panel test piece T, changes in appearance before and after the water resistance test, and changes in peel test and sensitivity measurement results were examined in the same manner as in Example 4. The results are shown in Table 2.

From the results of the appearance inspection shown in Table 2, panel test piece A of this example
, B and D showed no change in appearance even after being left under high temperature and high humidity for a long time, whereas in panel test piece T of the comparative example, swelling of the stimulable phosphor layer was observed. This seems to be due to the vinyl alcohol component in the polyvinyl butyral resin as a binder. When the stimulable phosphor layer swells in this way, it becomes excessively flexible, so as explained above, when installing the radiation image conversion panel, it is easily damaged by local external pressure when it is placed in the frame. Become.

In addition, there was no difference in the peel test results before and after the water resistance test for the panel test pieces A, B, and D of this example, and there was no peeling at all, but in the peel test of the panel test piece '1'' of the comparative example, The degree of peeling after the water resistance test was greater than that before the water resistance test. This is because the swelling of the photostimulable phosphor layer reduces the adhesion between the support and the photostimulable phosphor layer, and this makes it almost impossible to use it practically. It appears that the cause of this swelling of the stimulable phosphor layer is that the binder resin contains a large amount of vinyl alcohol component.

In addition, panel test pieces A, B, and I] of Examples of the present invention had no significant difference in sensitivity measurement results before and after the water resistance test, and no significant decrease in sensitivity was observed, but panel test piece T of Comparative Example A significant decrease in sensitivity was observed before and after the water resistance test. This is because the photostimulable phosphor layer of the panel test piece of the comparative example has high moisture permeability, so that the photostimulable phosphor changes with moisture, and this can hardly be used practically. The reason for the high moisture permeability of this stimulable phosphor layer is likely to be the result of the binder resin containing a large amount of vinyl alcohol component.

In addition, from the sensitivity measurement results before and after the water resistance test, among the panel test pieces A, B, and D of the example, A with a small vinyl alcohol component was particularly excellent, followed by B.

Example 5 Instead of the polyvinyl butyral resin of Example 1, the average degree of polymerization was 400, and / (x + y + z ) = 0.70 y / (x
+y +z ) -0,25z / (X +y +
A radiation image conversion panel test piece E of this example was obtained in the same manner as in Example 1, except that 30 parts by weight of polyvinyl acetoacetal resin with z ) = 0.05 was dissolved in 130 parts by weight of m-cresol. . The same measurements and tests as in Example 1 were performed using this panel test piece E.

The results are shown in Table 3.

Example 6 In place of the polyvinyl butyral resin of Example 1, average degree of polymerization was 450, x/(x+y+Z)=Q, 7Qy/(x
→−y −1−2) =0.25Z/(× +y 1z
) = 0.05 polyvinyl propional resin 30
A radiation image conversion panel test piece F@ of this example was obtained in the same manner as in Example 1, except that part by weight was dissolved in 130 parts by weight of m-cresol. The measurement and test results are shown in Table 3.

From Table 3, test pieces E and F of Examples 5 and 6 are excellent in durability against bending and light resistance, similar to Examples 1 to 3 above.

(Hereinafter, the margin of this page) ¥3 table Example 7 Instead of the polyvinyl butyral resin of Example 1, average degree of polymerization was 1200, x / (x + y + z) = 0.66y / (
x −1−y →−y,) =0.297, /(to +
A radiation image conversion panel test piece G of this example was obtained in the same manner as in Example 1 except that a polyvinyl butyral resin with y +7 ) =0.05 was used.

Using this radiation image conversion panel test piece G, measurements and tests similar to those in Example were conducted. The results are shown in Table 4.

Example 8 Instead of the polyvinyl butyral resin of Example 1, the average degree of polymerization was 1000, x/(x →−y→−z) =0.57y/(x→−
y +z ) -〇、27z / (to +y 10z
) - A radiation image conversion panel test piece (1) of this example was obtained in the same manner as in Example 1 except that the polyvinyl butyral resin No. 16 was used.

Example 1 using this radiation image conversion panel test piece I (
The same measurements and tests were conducted. The results are shown in Table 4.

Comparative Example 6 In place of the polyvinyl butyral resin of Example 1, the average degree of polymerization was 1000,
A radiation image conversion panel test piece U of this comparative example was obtained in the same manner as in Example 1 except that a polyvinyl butyral resin with z ) =0.29 was used.

The same measurements and tests as in Example 1 were performed using this panel test piece U. The results are shown in Table 4.

As shown in Table 4, panel test pieces G and H of Examples 7 and 8 have high durability against bending as in Examples 1 to 6, and the risk of cranking or the like due to bending can be reduced accordingly. On the other hand, the panel test piece U of Comparative Example 6 has low durability against bending and cracks occur in the stimulable phosphor layer when bent.

This appears to be because the adhesive force of the polyvinyl butyral resin decreased due to an increase in the proportion of the vinyl acetate component in the polyvinyl butyral resin as a binder. In addition, the results of the light resistance test showed that the Hanel test pieces G and H of Example 7.8 showed almost no decrease in sensitivity to either or both of the photostimulation excitation light and the erasure light, compared to the panel test piece U of the comparative example. Excellent light resistance. This is also seen to be the result of an increase in the proportion of vinyl acetate component in the polyvinyl butyral resin as a binder.

In addition, from the sensitivity measurement results based on the light resistance test results, among the panel test pieces G and H of the example, G, which has a small proportion of vinyl acetate-I component, was superior.

The measurement method and test method described in Section 2 are as follows.

(1) Measurement width of soft law 20! ! Ig, a radiographic panel test piece i71:l with a length of 50 mm was fixed horizontally with its photostimulable phosphor layer facing upward, and a tension gauge was used to measure the position 40 fins from this fixed end. The amount of bending of the above panel piece under load was measured. The larger this value is, the more flexible the panel is.

(2) Crack test: Occurrence of cracks in the stimulable phosphor layer when a radiation image conversion panel test piece with a width of 50 mm is wrapped around a glass tube with a diameter of 15 mm so that the stimulable phosphor layer surface faces outward. I observed the numbers. The greater the number of cracks, the lower the flexibility of the panel specimen and the lower its durability against bending.

(3) Peeling test for phosphor layer The stimulable phosphor layer of a 60 mm square radiation image conversion panel test piece was cut with a knife at 5 mm intervals. Next, a 30 x 30 mm cellophane tape was adhered onto the photostimulable phosphor layer, and then the panel test piece was fixed and the end of the cellophane tape was strongly pulled to peel the cellophane tape from the photostimulable phosphor layer. did. The surface irregularity of the stimulable phosphor layer peeled off from the support together with the cellophane tape was measured, and this was divided by the area of the cellophane tape originally adhered to the test piece to calculate the peeling rate (%). A higher peel rate indicates a lower adhesion of the stimulable phosphor layer to the support, and the panel has lower durability against bending.

(4) Light resistance test 150 against photostimulation excitation light and erasure light
Approximately 40 pieces from the W-shaped lamp (manufactured by Ushio Inc.)
A radiation image conversion panel test piece was placed at a position of cm, and the panel test piece was irradiated with light at an illuminance of 1.5 x 10 Lux -5 ec. The X-ray sensitivity of this panel test piece was measured before and after irradiation with light for -4 degrees, and after 60 hours of light irradiation. The sensitivity ratio was determined. The higher the ratio, the higher the light resistance of the panel to photostimulation excitation light or erasure light, and the less likely the binder is to yellow due to decomposition. ,
The sensitivity of the above panel test piece to X-rays was determined by irradiating the panel test piece with X-rays of 80 to ν [OmR], then stimulating the panel test piece with static laser light, and measuring the intensity of the produced stimulated destination. Ta. Furthermore, after irradiating the panel test piece with one or both of photostimulation excitation light and erasing light, a crack test similar to the above (2) was conducted to examine the deterioration of flexibility.

If this result is worse than the result in (2) above, it means that the binder has been degraded by one or both of the stimulated excitation light and the erasure light.

[Brief explanation of drawings]

The figure shows a radiation image conversion panel test piece A according to an example of the present invention.
B, C and Comparative Example Radiographic Image Conversion Panel Test Pieces P, Q
, R, and S are graphs showing measurement results of spectral reflectance over time. July 5, 1980 Patent applicant: Konishi Roku Photo Industry Co., Ltd. Procedural Official Report (spontaneous) August 25, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of Case 1988 Patent WM No. 120954 No. 2, Name of the invention Radiographic image conversion panel 3, Relationship with the person making the amendment Patent applicant Nobuhiko Kawamoto, 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo (127) Konishiroku Photo Industry Co., Ltd. Representative Nobuhiko Kawamoto 4 , Agent 5, Date of amendment order Voluntary 6, Number of inventions increased by amendment None 7, Subject of amendment "(11) of the detailed description of the invention in the specification" 8, Contents of amendment 1, Page 26 of the specification On the 6th line, rllOJ is corrected as 1-II o j. 2. On page 26, line 67 of the specification, the text ``rcu8g'' is corrected as [Cu, Ag J. 3. In the specification, page 27, line 6, rPcJ is corrected to ~1-1"hJ. 4. In the specification, page 26, line 6, 1'ZmJ is changed to 1'7.nJ. Correct n1. 5. Ming 1! III T! on page 28, line 8, rMa,
Correct the statement Ca SrJ to 1'MB, Ca+SrJ. 6. On page 28, line 19 of Book 1 of Mei II, the words "Japanese Unexamined Patent Publication No. 1600078/1980" are corrected to "Japanese Unexamined Patent Publication No. 160078/1983." 7. In the second line of page 29 of the specification, the words rZn and CdJ are corrected to rZn and Cdj. 8. On page 29, line 8 of Ming #llI, r5 XIO≦
"X≦0.5" means r5 x 10""≦X≦0.
Corrected to 51. 9. In the third line of page 53 of the specification, the statement r], 5 X 10Lux · sec J is corrected to rl, 5 X 105L+JX-sec J.

Claims (1)

[Scope of Claims] (1) A radiation image conversion panel having a stimulable phosphor layer formed by dispersing a stimulable phosphor in a binder on a support, wherein the binder is generally A radiation image conversion panel characterized by containing a polyvinyl acecool resin represented by the formula. (In the formula, R represents a lower alkyl group, and X + y and 2 are 0.40< x/ (x + y + z) < 0.79
0.20<y/(x+y+z)<Q
, 540<z/(x+y+z)<0.20 and 1g□<x+y+z<3000 and is an integer. ) (2) In the general formula of polyvinyl acecool resin, x, y and 2 are 0.44<x/ (x+y+z)<0.750.22
<y/ (x+y+z) <0.500 <z/(
The radiation image conversion panel according to claim 1, wherein the radiation image conversion panel is an integer that satisfies x + y + z) < 0.15 and 150 < x + y + z < 2000. (3) The radiation image conversion panel according to claim 1 or 2, wherein R in the polyvinyl acecool resin is a butyl group. (4) 50ii polyvinyl acetyl resin in the binder
% or more of the radiation image conversion panel according to claim 1, 2, or 3.