JP2001013298A - Radiation image conversion panel and method for manufacturing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radiation image conversion panel that is excellent in antifouling property, flaw resistance and durability and has a protective layer free from the defect of a film caused by the processing during the manufacture of the panel and an appropriate method for manufacturing it. SOLUTION: A radiation image conversion panel is fabricated by laminating one by one on a support phosphor layers which are made of stimulable phosphors and a protective layer where at least a resin composition layer containing a crosslinking fluorocarbon resin is located on a plastic film. When the plastic film used for the protective layer is maintained at a crosslinking temperature of the crosslinking fluorocarbon resin for 20 minutes, the heat shrinkage factor is set at less than 1.2% both in the MD direction and in the TD direction. The thickness of the plastic film is 1 to 20 μm, and it is preferable that the plastic film is a polyester film whose heat shrinkage factor is adjusted by a prior annealing treatment.

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 used in a radiation image conversion method using a stimulable phosphor and a method for manufacturing the same.

[0002]

2. Description of the Related Art As an alternative to the conventional radiographic method, there has been known a radiation image conversion method using a stimulable phosphor as described in, for example, JP-A-55-12145. This method uses a radiation image conversion panel (a stimulable phosphor sheet) containing a stimulable phosphor, and transmits radiation transmitted through a subject or emitted from a subject to the stimulable phosphor of the panel. By absorbing the stimulable phosphor with electromagnetic waves (excitation light) such as visible light and infrared light in a time series manner, the radiation energy stored in the stimulable phosphor is absorbed by the body. The fluorescent light is emitted (stimulated emission light), the fluorescent light is read photoelectrically to obtain an electric signal, and a radiation image of a subject or a subject is reproduced as a visible image based on the obtained electric signal. . After the reading of the panel is completed, after the remaining image is deleted, the panel is prepared for the next photographing. That is, the radiation image conversion panel is used repeatedly.

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 the radiographic method using a combination of a conventional radiographic film and an intensifying screen. There is an advantage that it can be obtained. Furthermore, in contrast to the conventional radiographic method, which consumes radiographic film for each photographing, the radiographic image conversion method uses the radiographic image conversion panel repeatedly, which is advantageous in terms of resource conservation and economic efficiency. It is.

[0004] A protective layer is usually provided on the surface of the stimulable phosphor layer (the surface not facing the support) to protect the phosphor layer from chemical alteration or physical impact. are doing. The protective layer is formed by applying a solution prepared by dissolving a transparent organic polymer substance such as a cellulose derivative or polymethyl methacrylate in an appropriate solvent onto the phosphor layer, or polyethylene. An organic polymer film such as terephthalate or a sheet for forming a protective layer such as a transparent glass plate is separately formed and fixed to the surface of the phosphor layer via an appropriate adhesive, or an inorganic compound is vapor-deposited to form the phosphor. Those formed on a layer are known.

In carrying out the radiation image conversion method, the radiation image conversion panel includes radiation irradiation (recording of a radiation image), irradiation of excitation light (reading of a recorded radiation image), irradiation of erasing light (remaining radiation image). Erasure). The transition of the radiation image conversion panel to each step is performed by a conveying means such as a belt or a roller. After one cycle, the panels are usually stacked and stored. However, when a radiation image conversion panel having a protective layer formed by coating as described above is repeatedly used in this manner, the radiation image conversion panel may be stained or scratched on the surface of the protective layer, for example. The image quality of the radiation image formed by the image conversion panel tends to gradually decrease.

[0006] The radiation image conversion panel is desired to provide an image having high sensitivity and good image quality (sharpness, granularity, etc.) similarly to the conventional radiographic method. It is an important issue to prevent the occurrence of excessive dirt and scratches. As such a protective layer material having excellent antifouling properties and scratch resistance, a fluorine-based resin containing a polysiloxane skeleton-containing oligomer or a perfluoroalkyl group-containing oligomer having low surface energy and excellent strength has been proposed. These are extremely effective in improving antifouling properties and scratch resistance, but they are not necessarily sufficient in durability of a coating film. No. 8-1900000, a protective film comprising a composite layer of a plastic film and a resin composition containing the fluorine-based resin was proposed. This protective film is excellent in durability in addition to stain resistance and scratch resistance. As a method for providing a uniform coating layer of a resin composition containing a fluorine-based resin, Japanese Patent Application Laid-Open No. Hei 10-28898 discloses a fluororesin coating layer on a protective film adhered on a temporary support with an adhesive layer. Is formed, and then a laminate of the protective film and the fluororesin coating or a laminate of the protective film, the fluororesin coating layer and the adhesive layer is peeled off from the temporary support, and a new,
Alternatively, a method has been proposed in which the original adhesive layer is pressed onto the stimulable phosphor layer. However, when a crosslinkable fluororesin having excellent strength and surface properties is selected as the fluororesin, in the manufacturing process, when a heat treatment is performed to crosslink the fluororesin, a part of the laminated plastic film is formed. It was found that there was a concern that heat shrinkage was caused to cause breakage and wrinkles of the protective layer laminate.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object the purpose of the present invention is to provide an antifouling property,
It is an object of the present invention to provide a radiation image storage panel having a protective layer which is excellent in scratch resistance and durability and has no film defect caused by processing at the time of manufacturing, and a suitable manufacturing method thereof.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a plastic film which is a protective layer having a desired antifouling property, scratch resistance and durability, and a resin composition layer containing a crosslinkable fluororesin. As a result of diligent study of the relationship, it has been found that the above problem can be solved by selecting a plastic film satisfying a specific heat shrink condition, and the present invention has been completed.

That is, in the radiation image conversion panel of the present invention, a phosphor layer made of a stimulable phosphor is provided on a support, and a resin composition layer containing at least a crosslinkable fluororesin is provided on a plastic film. A radiation image conversion panel in which protective layers are sequentially laminated, wherein the plastic film used for the protective layer has a cross-linking temperature of 2 ° C.
The heat shrinkage when held for 0 minutes is less than 1.2% in both the MD and TD directions. As the plastic film used here, it is preferable to use a polyester film having the above characteristics or a polyester film whose heat shrinkage rate has been adjusted to the above range by annealing beforehand. In a preferred embodiment, the resin composition layer contains a polysiloxane skeleton-containing oligomer or a perfluoroalkyl group-containing oligomer.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a radiation image storage panel according to the present invention, wherein a phosphor layer comprising a stimulable phosphor is provided on a support and at least a crosslinkable fluororesin is provided on a plastic film. A method for manufacturing a radiation image conversion panel, comprising sequentially providing a protective layer provided with a resin composition layer containing: a plastic film on a temporary support, and a fluororesin on the plastic film. Forming a resin composition layer by applying and heating a resin composition coating solution containing the resin composition, and peeling off the plastic film and the resin composition layer fixedly formed on the plastic film from the temporary support to form the phosphor. Pressure-bonding on the layer to form a protective layer, and the heat shrinkage of the plastic film when held at the crosslinking temperature of the crosslinkable fluororesin for 20 minutes is MD.
The direction and the TD direction are less than 1.2%. Further, the plastic film is annealed in advance, and the cross-linking temperature of the cross-linkable fluororesin is set at 20 ° C.
In a preferred embodiment, the method has a step of adjusting the heat shrinkage of the plastic film when held for one minute to be less than 1.2% in both the MD and TD directions.

In the present invention, the crosslinkable fluororesin is a polymer of an olefin containing fluorine (fluoroolefin) or a copolymer containing an olefin containing fluorine as a copolymer component. After mixing, it refers to one having the property of being cross-linked by heating to cure the resin composition layer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The gist of the present invention is to prevent defects caused by heat treatment in a process of manufacturing a protective layer in which a resin composition layer containing at least a crosslinkable fluorine-based resin is provided on a plastic film. Under a curing condition of the resin composition layer containing the crosslinkable fluororesin to be obtained, the heat shrinkage of the adjacent plastic film is set to a specific range.

Usually, a thermoplastic resin is used for the protective layer from the viewpoints of adhesiveness to an adjacent layer, flexibility of the layer, workability, and the like. It is unavoidable to cause a change in shape and a change in strength. On the other hand, from the viewpoint of the characteristics of the radiation image conversion panel, its performance is largely dependent on the phosphor layer, and the protective layer must impart antifouling properties, strength, durability, etc. without lowering its performance. Therefore, the thickness, strength, surface properties, and the like of the protective layer are naturally limited. The present inventors have comprehensively studied the effect of the material, thickness and heat shrinkability of the film, and the shape defect of the protective layer at the time of forming the panel, on the performance of the radiation image conversion panel. ,
If the heat shrinkage of the film is less than 1.2% in both the MD and TD directions when held for 20 minutes under the heating temperature, specifically, the crosslinking temperature condition of the crosslinking fluororesin used, It was found that the effect could be minimized and that both performance and appearance were within acceptable ranges.

When the thermal shrinkage of the film is at least 1.2% in either the MD direction or the TD direction, or both, the protective layer is likely to have undeniable folds and wrinkles, and the image quality of the radiation image conversion panel. Is not preferred because it affects This heat shrinkage is more preferably 1.0% or less. Here, the cross-linking temperature of the cross-linkable fluororesin used varies depending on the fluororesin, the cross-linking agent used, and the like, but can be appropriately determined by measuring the temperature at which cross-linking is actually performed. In a general evaluation method, 1
A range of 00 to 150 ° C. will be a guide.

The material of the plastic film that can be used for the protective layer of the radiation image storage panel of the present invention is not particularly limited, and heat-sensitive materials such as polyethylene terephthalate and polyethylene naphthalate, which are known as the protective layer material of the radiation image storage panel, are used. It can be arbitrarily selected from a polyamide-based resin such as a plastic polyester resin and an aramid (aromatic polyamide) resin and used. Of course, it is not limited to these materials, but one method is to select and use a plastic film having sufficient strength and high transparency, which has a small heat shrinkage rate of the material itself. is there. Although the cause of the thermal shrinkage is not clear, it is possible to reduce the internal stress by heating the stretched film that has remaining internal stress, such as stretched film, or to reduce the structure of the crystalline resin by heating. From this viewpoint, an amorphous material is more preferable.

It is also conceivable to perform an annealing treatment at a predetermined temperature in advance for the thermal shrinkage of a stretched film or the like to forcibly relax the stress of the plastic film and to improve the thermal stability of the dimensions. Specifically, it is preferable to perform in a temperature range that does not affect the strength and properties of the resin constituting the film. For example, in the case of a polyethylene terephthalate film, under a temperature condition of 50 to 180 ° C.
It is preferably performed for about 10 minutes to 24 hours, and more preferably for about 1 to 5 hours under a temperature condition of 70 to 120 ° C.

In addition, these internal stress relaxations occur in the MD direction,
One of the countermeasures is to have a certain thickness in order to reduce the influence on the CD direction. The thickness of the plastic film that can be used for the protective layer is generally 1 to
Although it is in the range of 10 μm, for example, in the case of the polyethylene terephthalate film, by setting the thickness to about 6 to 10 μm, the heat shrinkage can be kept in the above range.

A resin composition layer containing a crosslinkable fluororesin is formed on the surface of the plastic film having such heat shrinkage characteristics. Preferred embodiments of the resin composition are listed below. (1) A resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a polysiloxane skeleton-containing oligomer, and the polysiloxane skeleton-containing oligomer is contained in the resin composition layer in an amount of 0.01 to 10% by weight. %include.
(2) The resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a polysiloxane skeleton-containing oligomer, and the polysiloxane skeleton-containing oligomer is contained in the resin composition layer in an amount of 0.1 to 3% by weight. %include. (3) The resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a polysiloxane skeleton-containing oligomer containing at least one functional group. (4) The resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a polysiloxane skeleton-containing oligomer containing at least one hydroxyl group. (5) The resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a perfluoroalkyl group-containing oligomer, and the perfluoroalkyl group-containing oligomer is added to the resin composition layer in an amount of 0.01 to 10%. % By weight. (6) The resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a perfluoroalkyl group-containing oligomer, and the perfluoroalkyl group-containing oligomer is added to the resin composition layer in an amount of 0.1 to 3%. weight%
include. (7) The resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a perfluoroalkyl group-containing oligomer, and the perfluoroalkyl group-containing oligomer has at least one functional group in a molecular chain. Have (8) The resin composition layer containing a fluorine-based resin is composed of a fluorine-based resin and a perfluoroalkyl group-containing oligomer, and the perfluoroalkyl group-containing oligomer has a hydroxyl group in a molecular chain. .

(9) The fluororesin is a copolymer containing a fluoroolefin as a copolymer component. (10)
The fluororesin is a copolymer of fluoroolefin and vinyl ether. (11) The resin composition layer containing the fluorine-based resin contains the fluorine-based resin component in an amount of 30% by weight or more. (12) The resin composition layer containing the fluorine resin contains the fluorine resin component in an amount of 50% by weight or more.
(13) The resin composition layer containing the fluorine-based resin contains 70% by weight or more of the fluorine-based resin component. (14) The fluororesin is crosslinked in the resin composition layer containing the fluororesin. (15) The plastic film of the protective layer is a polyethylene terephthalate film or a polyethylene naphthalate film.

The protective layer disposed on the radiation image storage panel of the present invention is manufactured by applying a resin composition layer containing the preferred fluorine-based resin as described above on a plastic film having the above-mentioned thermal characteristics. The application of the fluorine-based resin to the plastic film may be carried out after the plastic film is bonded and fixed on the phosphor layer with an adhesive in advance, or the plastic film fixed on the surface of a temporary support such as a glass plate may be used. It may be performed on a film. In the latter case, since the plastic film is fixed on the temporary support, the advantage that the heat shrinkage of the film due to the heat treatment when forming the resin composition layer containing the fluorine-based resin is reduced from the free state. Having. When producing the protective layer on the temporary support,
The formed protective layer may be peeled off from the temporary support, disposed so that the plastic film is in contact with the phosphor layer, and bonded to each other with an adhesive.

The fluororesin-containing resin composition layer of the radiation image storage panel of the present invention may be a fluororesin alone, a fluororesin and another film-forming resin, or a fluororesin and a polysiloxane skeleton-containing oligomer or A coating liquid is prepared by dissolving or dispersing a perfluoroalkyl group-containing oligomer or the like in a solvent, and the resin composition layer forming material coating liquid is uniformly applied to the surface of the plastic film using a coating means such as a doctor blade. , By drying it. In addition, the polysiloxane skeleton-containing oligomer and the perfluoroalkyl group-containing oligomer may be used simultaneously with the fluorine-based resin.

Examples of the film-forming resin which may be used together with the fluorine-based resin when forming the resin composition layer containing the fluorine-based resin include polyurethane resins, polyacryl resins, and the like, which are known resins for forming a protective layer. Examples include cellulose derivatives, polymethyl methacrylate, polyester resins, and epoxy resins. The fluorine-based resin is a polymer of a fluorine-containing olefin (fluoroolefin) or a copolymer containing a fluorine-containing olefin as a copolymer component. Examples thereof include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, and polyvinyl fluoride. Examples include vinylidene fluoride, a tetrafluoroethylene-hexafluoropropylene copolymer, a fluoroolefin-vinyl ether copolymer, and the like.

Fluorine-based resins are generally insoluble in organic solvents, but copolymers containing fluoroolefins as copolymer components may be soluble in organic solvents depending on the other structural units (other than fluoroolefins) to be copolymerized. Therefore, a solution prepared by dissolving the resin in an appropriate solvent is applied to the phosphor layer and dried to easily form a resin composition layer containing a fluorine-based resin. Examples of such a copolymer include a fluoroolefin-vinyl ether copolymer. In addition, polytetrafluoroethylene and its modified product are also soluble in a suitable fluorinated organic solvent such as a perfluoro solvent, and therefore, like the copolymer containing the above-mentioned fluoroolefin as a copolymer component, the coating is performed. Thereby, a resin composition layer containing a fluorine-based resin can be formed. In the present invention, a crosslinkable fluororesin is used in the present invention from the viewpoint of the strength and durability of the resin film. In forming the resin composition layer containing a fluorine-based resin of the radiation image storage panel of the present invention, a crosslinking agent, a hardening agent, an anti-yellowing agent, a matting agent, a light absorbing agent, light scattering fine particles and the like are contained. Is also good.

In the present invention, the polysiloxane skeleton-containing oligomer which may be contained in the resin composition layer containing the fluororesin is preferably, for example, one having a dimethylpolysiloxane skeleton, and has at least one functional group (for example, a hydroxyl group). ). Its molecular weight (weight average) is preferably in the range of 500 to 100,000. In particular, the molecular weight is preferably in the range of 1,000 to 100,000, and more preferably in the range of 3,000 to 10,000. Further, a perfluoroalkyl group (eg, tetrafluoroethylene group) -containing oligomer is
At least one functional group (for example, a hydroxyl group:-
OH), and has a molecular weight (weight average) of 500
It is preferably in the range of ~ 100,000. In particular, the molecular weight is preferably in the range of 1,000 to 100,000, and more preferably in the range of 10,000 to 100,000. As described above, since the oligomer containing a functional group is used, a cross-linking reaction occurs between the oligomer and the resin composition layer-forming resin containing the fluorine-based resin when the resin composition layer containing the fluorine-based resin is formed. However, since the oligomer is incorporated into the molecular structure of the film-forming resin, the oligomer can be converted to the fluororesin even by long-term repeated use of the radiation image conversion panel or cleaning of the surface of the resin composition layer containing the fluororesin. Is not removed from the resin composition layer containing, and the effect of adding the oligomer is effective for a long period of time. The above oligomer is contained in the resin composition layer containing the fluororesin in an amount of 0.01 to 1%.
It is preferably contained in an amount within the range of 0% by weight,
In particular, it is preferably contained in an amount in the range of 0.1 to 2% by weight.

The protective layer and the manufacturing method thereof, which are characteristic features of the radiation image storage panel of the present invention, are as described above. This protection layer is also suitable for radiation image conversion panels having various known structures. Applicable to That is, the phosphor layer, the support, and the like of the radiation image conversion panel of the present invention can be appropriately selected from known ones, and these structures are also described in detail below.

The stimulable phosphor constituting the phosphor layer of the radiation image conversion panel of the present invention emits stimulable light when irradiated with radiation and then with excitation light. From this, it is desirable that the phosphor be a phosphor that emits stimulated light in a wavelength range of 300 to 500 nm by excitation light having a wavelength in the range of 400 to 900 nm. Examples of the stimulable phosphor used in the radiation image storage panel of the present invention include the above-mentioned JP-A-2-193100 and JP-A-4-310.
No. 900 is described in detail.

Of the known stimulable phosphors, europium- or cerium-activated alkaline earth metal halide-based phosphors and cerium-activated rare earth oxyhalide phosphors are particularly preferred because they exhibit high-luminance stimulable emission. . However, the stimulable phosphor used in the present invention is not limited to the above-described phosphors, and any phosphor can be used as long as it exhibits stimulable emission when irradiated with radiation and then irradiated with excitation light. There may be. The stimulable phosphor layer of the radiation image storage panel of the present invention is not only composed of a stimulable phosphor and a binder containing and supporting the stimulable phosphor in a dispersed state, but also stimulable without a binder. It may be composed of only a phosphor aggregate, or a phosphor layer in which a polymer substance is impregnated in the gaps between the stimulable phosphor aggregates.

Next, the method for producing the radiation image storage panel of the present invention will be described, taking as an example the case where the phosphor layer comprises a stimulable phosphor and a binder containing and supporting the stimulable phosphor in a dispersed state. The phosphor layer can be formed on a support by the following known method. First, a stimulable phosphor and a binder are added to a solvent and mixed well to prepare a coating solution in which the stimulable phosphor is uniformly dispersed in a binder solution.
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. Generally, the mixing ratio between the binder and the phosphor is 1%. It is selected from the range of 1: 1 to 1: 100 (weight ratio), and particularly preferably selected from the range of 1: 8 to 1:40 (weight ratio). The coating solution containing the phosphor and the binder prepared as described above is then uniformly applied to the surface of the support to form a coating film. This coating operation can be performed by using ordinary coating means, for example, a doctor blade, a roll coater, a knife coater, or the like.

The support can be arbitrarily selected from materials known as supports for conventional radiation image conversion panels. In a known radiation image conversion panel, a phosphor layer is provided 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 applied to the surface of the support on the side to form an adhesion-imparting layer, or a light-reflective layer made of a light-reflective material such as titanium dioxide, or a light-absorbent material such as carbon black It is known to provide an absorption layer or the like. The support used in the present invention can also be provided with these various layers, and the configuration thereof can be arbitrarily selected depending on the desired purpose and application of the radiation image storage panel. Further, JP-A-58-20020
As described in JP-A No. 0, the surface of the support on the side of the phosphor layer (the surface of the support on the side of the phosphor layer, the adhesion-imparting layer, In the case where a layer or a light absorbing layer is provided, the surface thereof means fine irregularities.

After forming a coating film on the support as described above, the coating film is dried to complete the formation of the stimulable phosphor layer on the support. The thickness of the phosphor layer varies depending on the characteristics of the intended radiation image conversion panel, the kind of the phosphor, the mixing ratio of the binder to the phosphor, and the like.
mm. However, this layer thickness is preferably 50 to 500 μm. The stimulable phosphor layer does not necessarily need to be formed by directly applying the coating solution on the support as described above. For example, the stimulable phosphor layer may be separately applied on a sheet such as a glass plate, a metal plate, or a plastic sheet. After forming a phosphor layer by applying and drying a liquid, the phosphor layer may be joined to the support by pressing the phosphor layer on a support or using an adhesive.

On this phosphor layer, protection consisting of a plastic film and a resin composition layer containing a fluororesin applied thereon, which is a characteristic feature of the radiation image storage panel of the present invention. Form a layer. In addition, an adhesive layer may be provided between the plastic film and the resin composition layer, if desired, or an adhesive layer may be provided between the phosphor layer and the plastic film. The method for manufacturing this protective layer is as described in detail above.

For the purpose of improving the sharpness of the obtained image, at least one of the layers constituting the radiation image conversion panel of the present invention absorbs excitation light,
The stimulated emission light may be colored by a colorant that does not absorb the light (see Japanese Patent Publication No. 54-23400).

[0033]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 A radiation image storage panel of the present invention was manufactured as follows.

As a phosphor layer forming material, a phosphor [BaF
Br _0.9 I _0.1 : 0.001Eu ₂ ⁺ ] 200 g, polyurethane resin (manufactured by Dainippon Ink and Chemicals, Pandex T)
-5265H) and 2 g of an epoxy resin (Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.) were added to methyl ethyl ketone, and dispersed with a propeller mixer.
A coating solution having a viscosity of 25 to 30 PS (25 ° C.) was prepared. This coating solution was applied onto a polyethylene terephthalate temporary support to which a silicone release agent had been applied,
Dry at 0 ° C. for 15 minutes. Next, the dried coating solution was peeled off from the temporary support to obtain a phosphor sheet having a thickness of 300 μm. Next, the phosphor sheet is superimposed on an undercoated polyethylene terephthalate film (thickness: 300 μm), heated and pressed using a heating roll at 60 to 70 ° C., and bonded to the support via an undercoat layer via the undercoat layer. A body layer (thickness: 200 μm) was obtained.

A transparent polyethylene terephthalate (hereinafter, appropriately referred to as PET) film (manufactured by Toray Industries, Inc.)
Lumirror 9-F53, thickness: 9 μm) and a heat-resistant re-peelable film (CT38, manufactured by PANAC Co., Ltd.) were prepared. The following resin composition layer coating solution containing a fluororesin was prepared. (Resin composition layer coating solution) Fluorine-based resin: fluoroolefin-vinyl ether copolymer (Lumiflon LF-504X, 30% by weight xylene solution manufactured by Asahi Glass Co., Ltd.) 185
g, cross-linking agent: 10 g of polyisocyanate (Sumijur N3500, manufactured by Sumitomo Bayer Urethane Co., Ltd., solid content: 100% by weight), and a slipping agent (alcohol-modified silicone oligomer (having a dimethylpolysiloxane skeleton and having hydroxyl groups at both ends) No. 2), 1 g of X-22-2809, solid content: 66% by weight of xylene-containing paste), manufactured by Shin-Etsu Chemical Co., Ltd., and an organic filler (melamine-
Formaldehyde; Nippon Shokubai Co., Ltd., Ebostar S
6) Methyl ethyl ketone was added to 1.3 g, 0.2 g of a coupling agent (acelyalkoxyaluminum diisocyanate; manufactured by Ajinomoto Co., Inc., Prenact AL-M) and 0.7 mg of a catalyst (dibutyltin dilaurate; manufactured by Kyodo Yakuhin Co., Ltd., LS1260). 133 g of solvent was added, and the viscosity was 3-4.
A coating solution adjusted to cps was prepared.

The above coating solution is applied to the PET film side of the plastic film by using a doctor blade, and then heat-treated at 140 ° C. for 20 minutes to be thermally cured and dried, and to have a fluororesin having a thickness of about 2 μm. Was provided to form a protective layer. The heat shrinkage of this polyethylene terephthalate film when heat-treated at 140 ° C. for 20 minutes is 1.0% in the MD direction and 0.8% in the CD direction.
%Met. On the phosphor layer surface, the protective layer formed as described above was pressed and bonded via an adhesive made of an unsaturated polyester resin to obtain a radiation image conversion panel.

Comparative Example 1 PE used in Example 1
T film was manufactured by Toray Industries, Inc., Lumirror 5A-F53,
A radiation image storage panel was manufactured in the same manner except that the thickness was 4.5 μm. The heat shrinkage of this polyethylene terephthalate film when heat-treated at 140 ° C. for 20 minutes was 1.5% in the MD direction and 1.3% in the CD direction.

Example 2 Radiation was carried out in the same manner as in Example 1 except that the 4.5 μm thick PET film used in Comparative Example 1 was annealed at 80 ° C. for 2 hours, and this annealed film was used. An image conversion panel was manufactured. The heat shrinkage of this annealed polyethylene terephthalate film when heat-treated at 140 ° C. for 20 minutes was 1.1% in the MD direction and 1.0% in the CD direction.

[Evaluation Test] Evaluation of Surface Properties When the surface of the radiation image conversion panel was visually evaluated, the panel surfaces of Examples 1 and 2 were not broken, wrinkles were not observed, and the smoothness and appearance were good. The film surface of No. 1 was broken and fine wrinkles were observed.

2. Transport durability test The radiation image conversion panels of Examples 1 and 2, which had no problem in appearance, were cut into rectangles of 100 mm x 250 mm to prepare test pieces. Next, this test piece is put into a transport system model in which the transport system of a commercially available radiation image conversion device is miniaturized, moved between the guide plate and the nip roll, and then moved along a rubber roll (diameter: 40 mm) by a transport belt. The operation of forcibly bending the inside and the outside once was performed, and finally, the carrying operation of returning to the original position between the guide plate and the nip roll (this is referred to as one carrying) was repeated 3,000 times. After the completion of this repeated transport operation, the surface of the protective layer of the test piece was observed. As a result, no damage such as cracks was found in the protective layer.

3. Sensitivity change test Image-like X-ray irradiation is performed on the radiation image conversion panel that has been subjected to the above 3,000 times transport durability test, and subsequently He-Ne
From the image data read by exciting the laser, the sensitivity (stimulated light emission amount) of the portion that was in contact with the transport member was calculated, and the change in sensitivity before and after the transport operation was examined. ２2%, indicating that the protective layer functions also in the performance of the radiation image storage panel.

[0043]

The radiation image conversion panel of the present invention is hardly cracked even after repeated transport operations in a general radiation image conversion apparatus, and is excellent in antifouling property, scratch resistance and durability,
This has the effect of having a protective layer free of film defects due to processing during manufacturing. Further, according to the method for manufacturing a radiation image conversion panel of the present invention, a radiation image conversion panel having an antifouling property, an anti-scratch property and an excellent durability having a protective layer having no film defect caused by the processing at the time of manufacturing is provided. It can be easily manufactured.

Claims (6)

[Claims] 1. A phosphor layer comprising a stimulable phosphor and a protective layer having a resin composition layer containing at least a crosslinkable fluororesin on a plastic film are sequentially laminated on a support. A radiation image conversion panel, wherein the heat shrinkage of the plastic film used for the protective layer when held at the crosslinking temperature of the crosslinkable fluororesin for 20 minutes is less than 1.2% in both the MD and TD directions. A radiation image conversion panel. 2. The method according to claim 1, wherein said plastic film has a thickness of 1 to 20.
The radiation image storage panel according to claim 1, which is a polyester film having a thickness of μm. 3. The radiation image storage panel according to claim 1, wherein the plastic film is a polyester film whose heat shrinkage is adjusted by annealing beforehand. 4. The radiation image storage panel according to claim 1, wherein the resin composition layer contains a polysiloxane skeleton-containing oligomer or a perfluoroalkyl group-containing oligomer. 5. A phosphor layer comprising a stimulable phosphor and a protective layer provided with a resin composition layer containing at least a crosslinkable fluororesin on a plastic film are sequentially laminated on a support. A method for manufacturing a radiation image conversion panel, comprising: bonding a plastic film on a temporary support; applying a resin composition coating solution containing a fluororesin on the plastic film; and heating to form a resin composition layer Removing the plastic film and the resin composition layer fixedly formed on the plastic film from the temporary support, and pressing the plastic film on the phosphor layer to form a protective layer, And a heat shrinkage factor of the plastic film when held at the crosslinking temperature of the crosslinkable fluororesin for 20 minutes is less than 1.2% in both the MD and TD directions. Method. 6. The heat shrinkage of the plastic film when the plastic film is pre-annealed and held at the cross-linking temperature of the cross-linkable fluororesin for 20 minutes is 1.2% in both the MD and TD directions. The method for manufacturing a radiation image storage panel according to claim 5, further comprising a step of adjusting the radiation image conversion panel so as to be less than the above.