JP2000352600A - Radiation image conversion panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radiation conversion panel with improved transportation durability by allowing an intermediate layer with a specific modulus of elasticity to be adjacent to a stimulable phosphor layer. SOLUTION: A radiation conversion panel 10 consists of a support 1 and a stimulable phosphor layer 2 and an intermediate layer 3 between the support 1 and the stimulable phosphor layer 2. A transparent protection film 4 for physically and chemically protecting the stimulable phosphor layer 2 is provided on the surface of the stimulable phosphor layer 2 at the opposite side of the support 1. Then, the intermediate layer 3 has a modulus of elasticity of 0.1-4.0×105 Pa. Further, the intermediate layer 3 with such modulus of elasticity preferably has a viscosity of 0.1-8.0×104 Pa.s. As a result, since the middle layer is elastically deformed even if the radiation conversion panel 10 is repeatedly flexed in a transportation mechanism, the stimulable phosphor layer 2 cannot be cracked easily, thus preventing the scattering of light when radiation is applied or excitation light is applied caused by the crack of the stimulable phosphor layer 2 regardless of repeated transportation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image conversion panel using a stimulable phosphor.

[0002]

2. Description of the Related Art As an alternative to the conventional radiographic method, there is known a radiation image conversion method using a stimulable phosphor as described in, for example, JP-A-55-12145. This method utilizes a radiation image conversion panel (also referred to as a stimulable phosphor sheet) containing a stimulable phosphor, and emits radiation transmitted through a subject or emitted from a subject into the stimulable phosphor. After being absorbed by the phosphor, the stimulable phosphor is excited by electromagnetic waves (excitation light) such as visible light and infrared light in a time-series manner, so that the radiation energy stored in the stimulable phosphor is fluorescently absorbed. The fluorescent light is emitted as (stimulated light), the fluorescence is read photoelectrically to obtain an electric signal, and a radiation image of a subject or a subject is reproduced as a visible image based on the obtained electric signal.

According to this radiographic image conversion method, a radiographic image with a large amount of information can be obtained with a much smaller exposure dose than a radiographic method using a combination of a conventional radiographic film and an intensifying screen. Further, since the radiation image conversion panel is repeatedly used, it is advantageous in terms of resource conservation and economic efficiency. Therefore, this method is very useful especially in direct medical radiography such as X-ray radiography for medical diagnosis.

A radiation image conversion panel used in a radiation image conversion method has a basic structure that includes a support and a stimulable phosphor provided on one side of the support, except that the phosphor layer has a self-supporting property. It consists of a body layer. In general, a transparent protective film is provided on the surface of the stimulable phosphor layer opposite to the support (the surface not facing the support), and the phosphor layer is chemically coated. Protection from physical deterioration or physical impact.

[0005] The stimulable phosphor layer generally comprises a stimulable phosphor and a binder containing and supporting the stimulable phosphor in a dispersed state. The stimulable phosphor absorbs radiation such as X-rays and then absorbs the radiation. It has the property of exhibiting stimulated emission when irradiated with excitation light. Therefore, the radiation transmitted through the subject or emitted from the subject is absorbed by the stimulable phosphor layer of the radiation image conversion panel in proportion to the radiation dose, and the radiation image of the subject or the subject is applied to the panel. It is formed as an energy storage image. This accumulated image can be emitted as stimulated emission light by irradiating the excitation light, and the accumulated image of radiation energy is imaged by photoelectrically reading the stimulated emission light and converting it into an electric signal. It is possible to do.

Although the radiation image conversion method is a very advantageous image forming method as described above, the radiation image conversion panel used in this method has the same high sensitivity as the intensifying screen used in the conventional radiography. In addition, it is desired to provide an image having good image quality (sharpness, granularity, etc.). The sensitivity of the radiation image conversion panel basically depends on the total stimulated emission of the stimulable phosphor contained in the panel,
The total amount of light emission depends not only on the emission luminance of the phosphor itself but also on the content of the phosphor in the phosphor layer. If the content of the phosphor is large, absorption of radiation such as X-rays is large, so that higher sensitivity can be obtained and at the same time, image quality (particularly, granularity) is improved. On the other hand, when the phosphor content in the phosphor layer is constant, the layer thickness can be reduced as the phosphor particles are more densely packed, so that the spread of excitation light due to scattering is reduced. And a relatively high sharpness can be obtained.

Radiation image conversion panels obtained by forming a phosphor layer on a support and compressing the phosphor layer are disclosed in JP-A-59-126299 and JP-A-59-126300. I have. The radiation image conversion panel disclosed here,
By compressing the phosphor layer, the density of the phosphor in the phosphor layer was made higher than that of the conventional radiation image conversion panel. As a result, the radiation image conversion panel has improved in sharpness, but on the other hand, there is a problem that the phosphor is partially destroyed by the compression treatment, and thus may be rather deteriorated in terms of granularity. .

In Japanese Patent Application Laid-Open No. 2-278197, a thermoplastic elastomer having a softening temperature or a melting point of 30 to 150 ° C. is used as a binder for the phosphor layer, and the phosphor layer is heated to a temperature higher than the softening temperature or the melting point. There has been proposed a radiation image conversion panel having excellent sharpness and granularity by compressing the image.

On the other hand, in the implementation of the radiation image conversion method,
The radiation image conversion panel emits radiation (records a radiation image), irradiates excitation light (reads a recorded radiation image),
The radiation image conversion panel is repeatedly used in a cycle of irradiating the erasing light (erasing the remaining radiation image), and the transition of the radiation image conversion panel to each step in the photographing apparatus is performed by a conveying means such as a belt or a roller. When the radiation image conversion panel obtained by the above-mentioned thermal compression is repeatedly transported in the above-mentioned photographing apparatus, there is a problem that cracks are easily generated in the phosphor layer. In other words, when radiation or excitation light is irradiated using a radiation image conversion panel with a crack in the phosphor layer, light is scattered at the crack and the image quality is reduced. Judgment becomes difficult.
For this reason, from the viewpoint of transport durability of the radiation image conversion panel, JP-A-8-36099 discloses that the binder contained in the phosphor layer has a softening temperature or melting point of 30 to 150 ° C. and 0.3
By using a thermoplastic elastomer having an elastic modulus of not more than kgf / mm ² , a radiation image conversion panel having excellent transport durability is provided.

However, in the medical field, there is a demand to further increase the transport speed in the image capturing apparatus in order to shorten the image capturing interval, and further improvement in transport durability is required.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a radiation image conversion panel having excellent transport durability. More specifically, an object of the present invention is to provide a radiation image conversion panel capable of obtaining a radiation image of excellent image quality even when repeated conveyance is performed for a long time in an imaging device. is there.

[0012]

A radiation image conversion panel according to the present invention comprises a support and a stimulable phosphor layer provided on at least one intermediate layer via at least one intermediate layer. Either one has an elastic modulus of 0.1 to 4.0 × 10 ⁵ Pa.

That is, the present inventors have conducted various studies on a radiation image conversion panel having a stimulable phosphor layer provided on a support with at least one intermediate layer interposed therebetween. By setting the elastic modulus to 0.1 to 4.0 × 10 ⁵ Pa, it was found that the occurrence of cracks due to repeated transport was no longer observed.

Here, the intermediate layer means a layer between the support and the stimulable phosphor layer, such as an undercoat layer, a light reflection layer, a light absorption layer, an adhesion imparting layer, an antistatic layer and the like. Means the layer of Any of the intermediate layer, an elastic modulus of 0.1 to 4.0 × 10 ⁵ Pa, preferably 0.5 to 4.0 × 10 ⁵ Pa, more preferably has an elastic modulus of 1.0~4.0 × 10 ⁵ Pa.

In a radiation image conversion panel having a stimulable phosphor layer provided on at least one intermediate layer on a support, if the image is repeatedly transported many times, the image is bent by a transport mechanism. The phosphor layer, which is closely related to the phosphor layer, is easily broken. Therefore, in order to prevent the phosphor layer from cracking, it is more desirable that the intermediate layer having the above-described elastic modulus is provided adjacent to the phosphor layer from the viewpoint of protecting the phosphor layer. When the intermediate layer is provided adjacent to the phosphor layer as described above, the elastic modulus described above may be smaller by 0 to 50%.

Further, the intermediate layer having such an elastic modulus is 0.1 to 8.0 × 10 ⁴ Pa · s, preferably 0.5 to 8.0 × 10 ⁴ Pa · s.
s, more preferably 1.0 to 8.0 × 10 ⁴ Pa · s.

The binder contained in the intermediate layer desirably contains at least a thermoplastic elastomer. With thermoplastic elastomer, plastic deformation easily occurs when heated and reversibly hardens when cooled,
It means a polymer material with remarkable elasticity around normal temperature. Examples of thermoplastic elastomers include polystyrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, ethylene vinyl acetate, polyvinyl chloride, natural rubber, fluorine rubber, and polyisoprene. , Chlorinated polyethylene, styrene-butadiene rubber, silicone rubber and the like, and a vinyl resin is particularly preferable. The vinyl resins, CH ₂ = CH- or copolymers of substances having radical or CH ₂ = C = group and broadly refers to generic term for synthetic resins derived from these, (meth) acrylic acid And vinyl resins containing moieties derived from esters or (meth) acrylic acid. The binder of the middle layer is
The specific thermoplastic elastomer alone may be used, or a mixture of two or more kinds of the specific thermoplastic elastomer and another thermoplastic elastomer may be used. Further, a polymer (eg, epoxy resin, acrylic resin, and polyimide resin) other than the thermoplastic elastomer may be further used.

It is desirable that the phosphor layer, the support and the intermediate layer be more firmly adhered to each other, and compression bonded from the viewpoint of densely filling the phosphor particles of the phosphor layer.

[0019]

According to the radiation image conversion panel of the present invention comprising a support and a stimulable phosphor layer with at least one intermediate layer interposed therebetween, any one of the intermediate layers has a thickness of 0.1 to 4.0 × 10 ⁵ Pa. Since the intermediate layer is elastically deformed even when repeatedly bent in the transport mechanism, the stimulable phosphor layer is unlikely to crack. Therefore, repeated use of the cycle of irradiation of radiation, irradiation of excitation light, irradiation of erasing light,
Even if it is repeatedly transported in the imaging device of the radiation image conversion panel, light is not scattered at the crack portion when irradiation of radiation or excitation light is performed due to cracks in the stimulable phosphor layer In addition, it is possible to prevent artifacts from occurring in the image.

The intermediate layer having such an elastic modulus is made adjacent to the phosphor layer to form a radiation image conversion panel, and the viscosity of the intermediate layer having an elastic modulus of 0.1 to 8.
By setting it to 0 × 10 ⁴ Pa · s, it is possible to effectively prevent the phosphor layer from being cracked. The use of a binder containing at least a thermoplastic elastomer, preferably a vinyl resin, as the binder contained in the intermediate layer makes it easier to obtain the above-mentioned intermediate layer.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of the radiation image conversion panel of the present invention.

As shown in FIG. 1, the radiation image conversion panel 10 of the present invention comprises a support 1, a stimulable phosphor layer 2, and an intermediate layer 3 between the support 1 and the stimulable phosphor layer 2. . In a normal radiation image conversion panel, a transparent protective film 4 for physically and chemically protecting the phosphor layer is provided on the surface of the phosphor layer 2 opposite to the support 1 side. . Middle layer 3
Is, for example, any one of an undercoat layer, a light reflection layer, an adhesion imparting layer, an antistatic layer, or the like, or a combination of these layers as appropriate according to the use of the radiation image conversion panel, and two or more layers are laminated. Is also included. That is, in a known radiation image conversion panel, the phosphor layer is used to enhance 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 polymer material such as gelatin is coated on the surface of the support on which the support is provided to form an adhesiveness-imparting layer, or a light-reflective layer made of a light-reflective material such as titanium dioxide or gadolinium oxide, or a light absorbing material such as carbon black It is known to provide a light absorbing layer or the like made of a luminescent substance, and the intermediate layer 3 is composed of such a support 1 and a stimulable phosphor layer 2.
Between the layers. The configuration of these various intermediate layers can be arbitrarily selected according to the desired purpose and use of the radiation image storage panel.

The radiation image conversion panel of the present invention is, for example,
It can be manufactured by the following method. First, the phosphor used in the stimulable phosphor layer of the radiation image storage panel of the present invention will be described. The stimulable phosphor is a phosphor that emits stimulable light when irradiated with excitation light after irradiating radiation as described above, but from a practical aspect, the wavelength is in the range of 400 to 900 nm. 300-500n depending on excitation light
It is desirable that the phosphor exhibit a photostimulated emission in the wavelength range of m. The stimulable phosphor used in the radiation image conversion panel of the present invention includes a divalent europium-activated alkaline earth metal halide-based phosphor, a cerium-activated alkaline earth metal-halide-based phosphor, and a cerium-activated rare earth. Oxyhalide-based phosphors are preferred because they exhibit stimulated emission with high luminance. However, the stimulable phosphor used in the present invention is not limited to such a phosphor, and any phosphor that emits stimulable light when irradiated with radiation and then with excitation light is used. It may be something.

A coating solution for forming a phosphor layer using the stimulable phosphor described above is prepared as follows. The stimulable phosphor and the binder are added to an appropriate solvent and mixed well to prepare a coating solution for forming a phosphor layer in which the stimulable phosphor is uniformly dispersed in the binder solution. The binder used herein has a softening temperature or a melting point of 30 to 150 ° C. and a thermal elasticity of 0.3 kgf / mm ² or less as described in, for example, JP-A-8-36099. An elastomer containing a plastic elastomer as a main component (preferably 60% or more of the binder) can be used. A mixture of several thermoplastic elastomers may be used, or a polymer other than the thermoplastic elastomer (eg, an epoxy resin, an acrylic resin, and a polyimide resin) may be further used.

Examples of the solvent for preparing the coating solution include lower alcohols such as methanol, ethanol, n-propanol and n-butanol; hydrocarbons containing a chlorine atom such as methylene chloride and ethylene chloride; acetone, methyl ethyl ketone and methyl isobutyl ketone. Esters of lower fatty acids such as methyl acetate, ethyl acetate and butyl acetate with lower alcohols; ethers such as dioxane, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether and tetrahydrofuran; and mixtures thereof. it can.
The mixing ratio between the binder and the stimulable phosphor in the coating solution varies depending on the characteristics of the intended radiation image conversion panel, the type of the phosphor, and the like. In general, the mixing ratio between the binder and the phosphor is 1 : 1 to 1: 100 (weight ratio), and particularly preferably in the range of 1: 8 to 1:40 (weight ratio).

The coating solution contains a dispersant for improving the dispersibility of the phosphor in the coating solution, and also enhances the binding force between the binder and the phosphor in the formed phosphor layer. Various additives such as a plasticizer may be mixed. Examples of dispersants used for such purposes include phthalic acid, stearic acid, caproic acid, and lipophilic surfactants. Examples of the plasticizer include phosphate esters such as triphenyl phosphate, tricresyl phosphate, and diphenyl phosphate; phthalate esters such as diethyl phthalate and dimethoxyethyl phthalate; ethyl phthalylethyl glycolate, and butyl glycolate Glycolic acid esters such as phthalylbutyl; and polyesters of polyethylene glycol and aliphatic dibasic acids, such as polyesters of triethylene glycol and adipic acid, and polyesters of diethylene glycol and succinic acid.

The coating solution containing the phosphor and the binder prepared as described above is then uniformly applied to the surface of a temporary support for sheet formation to form a coating film of the coating solution. I do. This coating operation is performed by a normal coating means, for example,
It can be performed by using a doctor blade, a roll coater, a knife coater or the like. The temporary support is, for example, a glass, a metal plate, various materials used as a support for an intensifying screen (or an intensifying screen) in a conventional radiographic method, or a support for a radiation image conversion panel. Can be arbitrarily selected from known materials. Examples of such materials include films of plastic substances such as cellulose acetate, polyester, polyethylene terephthalate, polyamide, polyimide, triacetate, polycarbonate, aluminum foil, metal sheets such as aluminum alloy foil, ordinary paper, baryta paper, resin Examples thereof include coated paper, pigment paper containing a pigment such as titanium dioxide, paper sized with polyvinyl alcohol, and the like, and plates or sheets of ceramics such as alumina, zirconia, magnesia, and titania. A coating solution for forming a phosphor layer is applied on the temporary support, dried, and then peeled off from the temporary support to form a phosphor sheet to be a phosphor layer of the radiation image conversion panel. Therefore, it is preferable to apply a release agent on the surface of the temporary support in advance so that the formed phosphor sheet can be easily peeled off from the temporary support.

Next, a support for the radiation image conversion panel is prepared separately from the phosphor sheet formed as described above. This support can be arbitrarily selected from the same materials as the temporary support used when forming the phosphor sheet. On the support, the above-mentioned intermediate layer is formed. The intermediate layer is an adhesion-imparting layer, a light reflecting layer, a light absorbing layer, an undercoat layer, and the like. When having two or more intermediate layers, any one of them is 0.1 to 4.0 × 10 ⁵ P
elastic modulus of a, preferably 0.5 to 4.0 × 10 ⁵ Pa, and even 1.0
It preferably has an elastic modulus of 4.04.0 × 10 ⁵ Pa. Also,
When there are two or more intermediate layers, it is preferable that the intermediate layer having such an elastic modulus is provided so as to be adjacent to the phosphor layer. Moreover, viscosity is 0.1~8.0 × 10 ⁴ Pa · s for the intermediate layer having an elastic modulus, - preferably 0.5 to 8.0 × 10 ⁴ Pa
s, more preferably 1.0 to 8.0 × 10 ⁴ Pa · s. Further, as described in JP-A-58-200200, for the purpose of improving the sharpness of the obtained image, the surface of an intermediate layer 3 such as an adhesion imparting layer, a light reflecting layer or a light absorbing layer is provided. Fine irregularities may be formed.

The phosphor sheet obtained above is placed on the support on which the intermediate layer is formed, and is adhered to the support while compressing at a temperature higher than the softening temperature or the melting point of the polymer. Examples of the compression apparatus used for the compression processing of the present invention include generally known apparatuses such as a calender roll and a hot press. For example, the compression treatment by a calender roll is performed by placing the phosphor sheet on a support and passing the phosphor sheet at a constant speed between rollers heated to a temperature higher than the softening temperature or melting point of the polymer. However, the compression device used in the present invention is not limited to these devices, and may be any device capable of compressing the above-mentioned sheet while heating it. The pressure during compression is 50kgw / cm
^It is generally ² or more, and preferably 200 to 700 kgw / cm ² . The upper and lower roll temperatures are generally equal to or higher than the softening temperature or the melting point as described above, and are preferably performed at a temperature 10 to 50 ° C. higher than the softening temperature. It is generally preferred that the upper and lower roll temperatures are generally the same. Feed rate is 0.1 ~ 5.0
m / min is preferred.

The transparent protective film is made of, for example, cellulose derivatives such as cellulose acetate and nitrocellulose; or polymethyl methacrylate, polyvinyl butyral,
Polyvinyl formal, polycarbonate, polyvinyl acetate, vinyl chloride / vinyl acetate copolymer, fluororesin (eg, fluoroolefin / vinyl ether copolymer)
A solution prepared by dissolving a transparent polymer material such as a synthetic polymer material in an appropriate solvent can be formed by applying a solution to the surface of the phosphor layer. A crosslinking agent such as polyisocyanate can be used as appropriate. Alternatively, a plastic sheet made of polyethylene terephthalate, polyethylene naphthalate, polyethylene, polyvinylidene chloride, polyamide, and the like; and a protective film forming sheet such as a transparent glass plate are separately formed, and an appropriate adhesive is applied to the surface of the phosphor layer. It can also be formed by a method such as bonding by using. The thickness of the protective film is generally in the range of about 0.1 to 20 μm.

Further, for the purpose of improving the sharpness of the obtained image, at least one of the above layers may be provided with a colored layer which absorbs excitation light and does not absorb stimulated emission light (Japanese Patent Publication No. No. 59-23400). Next, examples of the present invention will be described. However, these embodiments do not limit the present invention.

Example 1 (1) Formation of Phosphor Sheet (Phosphor Layer) Phosphor: BaFBr0.85I0.15: Eu ²⁺ 200 g Binder: 7.4 g of polyurethane elastomer Crosslinker: 0.6 g of polyisocyanate Additive : Epoxy resin 2g Polyurethane elastomer is product name T5265H (manufactured by Dainippon Ink & Chemicals, Inc.) Polyisocyanate is product name Coronate HX (manufactured by Nippon Polyurethane Co., Ltd.) Epoxy resin is product name EP1001 (manufactured by Yuka Shell Epoxy) Was used. The above phosphor sheet composition material was added to methyl ethyl ketone and dispersed with a propeller mixer, and the viscosity was 30 PS (25
° C). This is treated with polyethylene terephthalate (temporary support,
It was coated on a 180 µm thick layer, dried, and then peeled off from the temporary support to form a phosphor sheet (270 µm thick).

(2) Formation of Intermediate Layer (Intermediate Layer is Light Reflective Layer) Light Reflective Filler: Fine Particles of Gadolinium Oxide (Gd ₂ O ₃ ) 15 g Binder: 150 g of Soft Acrylic Resin Additive: 7.0 g of Phthalate Agent: ZnO whisker 10 g Colorant: ultramarine blue 0.4 g Fine particles of gadolinium oxide (Gd ₂ O ₃ ), 90% by weight of all particles having a particle diameter in the range of 1 to 5 μm,
The soft acrylic resin is Chris Coat P-1018GS
(20% solution) (manufactured by Dainippon Ink and Chemicals, Inc.) was used. The material of the above composition was added to methyl ethyl ketone, dispersed and mixed using a propeller mixer, and the viscosity was 5 to 10 PS.
(20 ° C.) to prepare a coating liquid for forming an intermediate layer. Thickness 300μm
The barium sulfate kneaded and mixed polyethylene terephthalate (support) is placed horizontally on a glass plate, and the above coating solution for forming an undercoat layer is uniformly applied on the support using a doctor blade, and then the coating film is dried. Then, an intermediate layer (layer thickness: 23 μm) was formed on the support.

The phosphor sheet prepared above was placed on the intermediate layer formed on the support and compressed. Compression, using a calender roll, the pressure of the 450kgw / cm ^2,
The operation was continuously performed under the conditions of an upper roll temperature of 90 ° C., a lower roll temperature of 75 ° C., and a feed rate of 0.5 m / min. By this compression, the phosphor sheet and the support were completely fused.
The thickness of the phosphor layer after fusion was 205 μm.

After fusion, a transparent film of polyethylene terephthalate (thickness: 6 μm) coated with a polyester measuring adhesive on one side is thermocompression bonded so that the adhesive layer is bonded to the phosphor surface to form a transparent protective film. Formed.

Example 2 The procedure of Example 1 was repeated, except that the light reflecting filler of the intermediate layer was not added, the phthalate ester additive was changed to 8 g, and the undercoat layer having a thickness of 19 μm was formed as the intermediate layer. A radiation image storage panel was manufactured in the same manner as in Example 1.

[Comparative Example 1] In Example 1, powdered BaFBr (average particle size: 2 µm) was used as a light reflecting filler for the intermediate layer.
60g, 3.5g of phthalate as additive, thickness 22
A radiation image storage panel was manufactured in the same manner as in Example 1, except that the μm undercoat layer was formed as an intermediate layer.

[0038] In Comparative Example 2 Example 1, changing the fine particles of gadolinium oxide as a light reflecting filler in the intermediate layer (Gd ₂ O ₃₎ 30g, a phthalic acid ester additives 3.5 g, thickness 16 [mu] _m A radiation image storage panel was manufactured in the same manner as in Example 1, except that the undercoat layer was formed as an intermediate layer.

Comparative Example 3 In Example 1, 60 g of gadolinium oxide (Gd ₂ O ₃ ) fine particles were used as the light reflecting filler of the intermediate layer, and 24 g of polyurethane elastomer as the binder was used.
g, additive phthalate to epoxy resin (product name
Changed to EP1001, 6.0 g of oiled shell epoxy) and changed to 10 g of conductive whisker of K ₂ O ・ nTiO ₂ (conductively treated with SnO ₂ and InO ₂ ) as conductive agent, and 30 μm thick undercoat layer A radiation image storage panel was manufactured in the same manner as in Example 1 except that the radiation image conversion panel was formed as an intermediate layer.

The viscoelasticity of the intermediate layer used for manufacturing the radiation image storage panels of the above Examples and Comparative Examples was determined as follows.

1) Preparation of Test Piece The intermediate layer coating solution was applied on polyethylene terephthalate (temporary support, thickness 180 μm) coated with a release agent, dried, and then peeled off from the temporary support to remove the intermediate layer. A sheet was formed, peeled off and overlaid to produce a test piece having a thickness of about 500 μm.

2) Measurement method As a test device, a viscoelastic device (Rheostress RS75, PP20
H sensor (manufactured by HAAKE) was used. Specimen diameter 2
Cut to 0mm, 0.5% strain against thickness, frequency 1Hz,
The elastic modulus, viscosity and tan delta were measured at room temperature (25 ° C.). Table 1 shows the results.

[0043]

[Table 1]

The transport durability of the obtained radiation image conversion panel was evaluated as follows. The radiation image conversion panel was cut into a size of 100 mm × 250 mm, and the obtained test piece was conveyed in a test conveyance device shown in FIG. First, a test piece is inserted from the loading port 11 and moved between the guide plate 12 and the nip roll (diameter 25 mm) 13 so that the transfer belt
According to 14, after bending inward along a rubber roll (diameter 40 mm) 15 and then bending outward, it was further moved between the guide plate and the nip roll. Repeat this transport operation,
The phosphor layer of the test piece was observed for damage (crack). Table 2 shows the results.

[0045]

[Table 1]

As is clear from the above results, Example 1
In the radiation image storage panel of the present invention obtained in the above 2 and 2, the intermediate layer between the support and the stimulable phosphor layer is 0.1 to 4.0 × 10 ⁵ Pa
Therefore, no cracks or the like are generated in the phosphor layer even when the operation of transporting the panel is repeated. That is,
When bending or impact due to transport is repeatedly applied, in the conventional phosphor layer (Comparative Examples 1 to 3), a large tensile stress is generated due to bending or impact at the interface between the phosphor and the binder in the phosphor layer. Although cracks occur in the phosphor layer, the phosphor layer of the present invention has an elastic modulus of 0.1 to 4.0 × 10 ⁵ Pa because any of the intermediate layers between the support and the stimulable phosphor layer has an elastic modulus of 0.1 to 4.0 × 10 ⁵ Pa. It is considered that almost no tensile stress is generated and no crack is generated. The cracks observed in Comparative Examples 1 to 3 were found in both the phosphor layer and the protective film. This was because the cracks in the phosphor layer also caused the protective film to crack. Was.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a radiation image conversion panel of the present invention.

FIG. 2 is a schematic view of an apparatus for evaluating the transport durability of the radiation image conversion panel.

[Explanation of symbols]

 Reference Signs List 1 support 2 stimulable phosphor layer 3 intermediate layer

Claims (6)

[Claims] 1. A radiation image conversion panel comprising a support and a stimulable phosphor layer provided on at least one intermediate layer via at least one intermediate layer, wherein one of the intermediate layers has an elastic modulus of 0.1 to 4.0 × 10 ⁵ Pa. A radiation image conversion panel comprising: 2. The radiation image conversion panel according to claim 1, wherein the intermediate layer having the elastic modulus is adjacent to the phosphor layer. 3. The viscosity of the intermediate layer having the elastic modulus is 0.1.
3. The radiation image conversion panel according to claim 1, wherein the radiation image conversion panel has a pressure of about 8.0 × 10 ⁴ Pa · s. 4. The radiation image conversion panel according to claim 1, wherein the phosphor layer, the support, and the intermediate layer are compression-bonded. 5. The radiation image storage panel according to claim 1, wherein the binder contained in the intermediate layer having the elastic modulus contains at least a thermoplastic elastomer. 6. The radiation image conversion panel according to claim 1, wherein the thermoplastic elastomer is a vinyl resin.