JPH03134598A - Radiation image conversion panel and its manufacturing method - Google Patents

Abstract

PURPOSE:To intend improvement of humidity resistance by forming a coating layer of an organic solvent solution on the surface of a stimulated phosphorescent particle, by mixing the particles obtained by drying up particles coated with the solution, with a solution containing a binder resin, and by applying it on a carrier body and drying it up. CONSTITUTION:For the first place, after dispersing stimulated phosphorescent particles into a solution containing a fluorine-containing-polymer which is soluble to organic solvents, the solvents are removed, and thereafter it is dried up and the particles are applied with a coating containing the fluorine-containing-polymer. The fluorine- containing-polymer is a olefin polymer or the like containing a fluorine, and a poly- tetra-fluorethylene, for instance, is selected. After that, the stimulated phosphorescence and a binder agent are added to an appropriate solvent and mixed sufficiently to be regulated as a coating liquid. A protein such as a gelatine and the like is used as the binder agent. Mixing ratio of the binder agent and the stimulated phosphorescence differs according to the characteristics of a target ratiation image conversion panel, and is selected from a range of 1:1 to 1:100 (in weight ratio). A coating is formed on a carrier body and then dried up.

Description

DETAILED DESCRIPTION OF THE INVENTION [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.

[Technical Background of the Invention and Prior Art 1 A radiation image conversion method using a stimulable phosphor is known as an alternative to conventional radiography. This method is
It uses a radiation image conversion panel (also called a stimulable phosphor sheet) containing a stimulable phosphor, and the radiation transmitted through the subject or emitted from the subject is absorbed by the stimulable phosphor in the panel. Then, by exciting the stimulable phosphor in a time-series manner with electromagnetic waves (excitation light) such as visible light and infrared rays, the radiation energy accumulated in the stimulable phosphor is converted into fluorescence (luminescence). The fluorescent light is emitted as exhaustion (exhaustive light), this fluorescence is read photoelectrically to obtain an electrical signal, and based on the electrical signal obtained, the radiation image of the subject or subject is reproduced as a visible image. On the other hand, the panel that has been read is prepared for the next photographing after the remaining images are erased. That is, the radiation image conversion panel is used repeatedly.

According to this radiation image conversion method, it is possible to obtain a radiation image with a rich amount of information with a much smaller amount of IIA exposure compared to the conventional radiography method that uses a combination of a radiographic film and an intensifying screen. It has the advantage of being able to Furthermore, in contrast to conventional radiography, which consumes radiographic film for each imaging session, this radiographic image conversion method uses the radiographic image conversion panel repeatedly, which is advantageous in terms of resource conservation and economic efficiency. It is.

The radiation image conversion panel used in the radiation image conversion method is
The basic structure consists of a support and a stimulable phosphor layer provided on the surface of the support, but if the phosphor layer is self-supporting, the support is not necessarily required.

The stimulable phosphor layer includes not only a stimulable phosphor layer and a binder that contains and supports the stimulable phosphor in a dispersed state, but also a layer that does not contain a binder and is formed by a vapor deposition method or a sintering method. One that is composed only of aggregates of stimulable phosphor is known. Furthermore, the applicant has already filed a patent application for a radiation image conversion panel having a stimulable phosphor layer in which the gaps between aggregates of stimulable phosphor are impregnated with a polymeric substance. In any of these phosphor layers, the stimulable phosphor has the property of exhibiting stimulated luminescence when irradiated with excitation light after absorbing radiation such as X-rays. The radiation emitted from the specimen is absorbed by the stimulable phosphor layer of the radiation image conversion panel in proportion to the radiation dose, and a radiation image of the subject or subject is formed on the panel as an image of accumulated radiation energy. . This accumulated image can be emitted as stimulated luminescence light by irradiating the excitation light, and by reading this stimulated luminescence light in a charging manner and converting it into an electrical signal, the accumulated image of radiation energy can be imaged. It becomes possible to convert into

By the way, as mentioned above, since the radiation image conversion panel is used repeatedly, the stimulable phosphor used therein must be designed so that it will not deteriorate even after long-term use. It is necessary to

Many photostimulable phosphors, such as divalent europium-activated alkaline earth metal fluorohalide phosphors, gradually deteriorate upon contact with moisture in the air, and their stimulable phosphors deteriorate during long-term storage. It is known that the luminance of the phosphor is low F, and therefore various proposals have been made to protect the phosphor from moisture in the air.

For example, a radiation image storage panel using a phosphor whose surface is treated with silicone oil is already known. In this radiation image storage panel, the phosphors are protected by water-repellent silicone oil, so the moisture resistance has been improved to some extent, but the degree of moisture resistance is still not satisfactory, and further improvements in moisture resistance are needed. A radiation image conversion panel with a

It is also known that the moisture resistance of radiation image storage panels can be greatly improved by coating phosphors with fluorine-based compounds such as polyvinylidene fluoride. , are completely or only slightly soluble in organic solvents, so when coating a phosphor with these, it is necessary to dry mix the fine powder of these fluorine-based compounds and the phosphor in advance, and then perform a baking process. . However, this baking process exposes the phosphor to high temperatures, which often causes deterioration of the phosphor.

[Summary of the Invention] 1. An object of the present invention is to provide a radiation image storage panel with improved moisture resistance. Another object of the present invention is to provide a method for producing a radiation image conversion panel that can produce a radiation image conversion panel with improved moisture resistance without causing deterioration of the phosphor. be.

The present invention resides in a radiation image storage panel characterized in that it includes photostimulable phosphor particles covered with a film containing a fluororesin soluble in an organic solvent.

The above-mentioned radiation image conversion panel comprises: a) forming a coating layer of an organic solvent solution containing a resin including a fluororesin in a dissolved state on the surface of the stimulable phosphor particles; b) the resulting solution coating Drying the particles to obtain phosphor particles having a fluororesin-containing resin coating layer; C) Mixing the obtained phosphor particles with a resin coating layer with a binder resin-containing solution to coat the phosphor. It can be easily obtained by a method for producing a radiation image conversion panel, which is characterized in that it includes the following steps: d) coating a phosphor coating solution on a support and then drying it.

Typical examples of the fluororesin soluble in organic solvents include polymers of olefins containing fluorine (fluoroolefins) or copolymers containing olefins containing fluorine as a copolymer component.

Furthermore, the film containing the above-mentioned fluororesin may be crosslinked.

Since the radiation image conversion panel of the present invention uses a fluororesin soluble in an organic solvent as a coating material for the phosphor, it has greater moisture resistance than conventional panels. Also,
The method for manufacturing the radiation image conversion panel of the present invention involves dispersing phosphor particles in a solution containing a fluororesin soluble in an organic solvent, removing the solvent, and then drying to coat the phosphor particles. There is no need for such a baking process, and therefore, there is no problem that the phosphor deteriorates during the manufacturing process.

Preferred embodiments of the present invention are listed below.

(1) The fluororesin is at least one fluororesin selected from the group consisting of a copolymer containing a fluoroolefin as a copolymer component, polytetrafluoroethylene, and a modified polytetrafluoroethylene. A radiographic image conversion panel.

(2) A radiographic image characterized in that the fluororesin is at least one fluororesin selected from the group consisting of a copolymer of fluoroolefin and vinyl ether, polytetrafluoroethylene, and modified polytetrafluoroethylene. Conversion panel.

(3) A radiation image storage panel, wherein the fluororesin is at least one fluororesin selected from the group consisting of a copolymer of fluoroolefin and vinyl ether and a modified polytetrafluoroethylene.

(4) A radiation image storage panel characterized in that the first fluorine-based tree is a copolymer of fluoroolefin and vinyl ether.

(5) A radiation image storage panel, wherein the fluororesin is polytetrafluoroethylene or a modified product thereof.

(6) The fluororesin component in the above coating is 30% by weight or more.
A radiation image conversion panel characterized in that:

(7) A radiation image conversion panel characterized in that the fluororesin component in the coating is 50% by weight or more.

(8) A radiation image conversion panel characterized in that the fluororesin component in the coating is 70% by weight or more.

(9) A radiation image conversion panel characterized in that the fluororesin in the coating is crosslinked.

(10') The fluororesin described in l. is at least one fluororesin selected from the group consisting of a copolymer containing a fluoroolefin as a copolymer component, polytetrafluoroethylene, and a modified polytetrafluoroethylene. A manufacturing method for a characteristic radiation image conversion panel.

(11) A radiographic image characterized in that the fluororesin is at least one fluororesin selected from the group consisting of a copolymer of fluoroolefin and vinyl ether, polytetrafluoroethylene, and modified polytetrafluoroethylene. Method of manufacturing conversion panels.

(12) A method for producing a radiation image storage panel, characterized in that the fluororesin is at least one fluororesin selected from the group consisting of a copolymer of fluoroolefin and vinyl ether and a modified polytetrafluoroethylene. .

(13) A method for producing a radiation image storage panel, wherein the fluororesin is a copolymer of fluoroolefin and vinyl ether.

(14) A method for producing a radiation image storage panel, wherein the fluororesin is polytetrafluoroethylene or a modified product thereof.

[Detailed Description of the Invention] The radiation image conversion panel of the present invention and its manufacturing method will be described in detail below.

First, the stimulable phosphor constituting the phosphor layer of the radiation image conversion panel of the present invention will be described.

As mentioned above, a stimulable phosphor is a phosphor that exhibits stimulated luminescence when irradiated with radiation and then irradiated with excitation light.
From a practical standpoint, a phosphor that exhibits stimulated luminescence in a wavelength range of 300 to 500 nm by excitation light in a wavelength range of 400 to 900 nm is desirable. Examples of stimulable phosphors used in the radiation image storage panel of the present invention include SrS:Ce, Sm, SrS:Eu, Sm, ThO2
:Er, and La2O2S :Eu.

Sm.

2nS: Cu, Pb%BaO-xAu, 03:E
u (however, 0.8≦X≦10), and M”0−x
SiO□ :A (However, M” is Mg, Ca, Sr,
Zn, Cd, or Ba, and A is Ce, Tb, Eu
, Tm, Pb, Tj2, Bi, or Mn, and X
is 0.5≦X≦2.5), (Ba, −, −,, MgX, Ca,)FX: aEu
(However, X is at least one of CfL and Br, X and y are 0<x+y≦0.6, and xy≠0, and a is 1O-6≦a≦5X10-' ), LnOX : xA (however, Ln is La, Y, Gd
, at least one of g and Lu, and X is CJ! and Br, A is at least one of Ce and Tb, and X is O<x≦0.2
It is. Furthermore, the notation LnOX indicates that the above Ln, oxygen O, and above X constitute a host crystal with a PbFCl type crystal structure, and these elements always have a 1:1:1 atomic ratio. The ratio does not indicate that it is contained in the above phosphor. For example, in Japanese Patent Application No. 1-143644 filed by the present applicant, the ratio X/Ln of the above Ln and the above X is expressed as an atomic ratio of 0.500<
A LnOX:xCe phosphor with X/Ln≦0.998 is disclosed. )(Ba,-X,M”)FX
: yA (However, M2+ is Mg, Ca, Sr, Z
n, and at least one of Cd, X is C1, B
r, and at least one of ■, A is Eu, Tb
, CeTm, Dy, Pr, Ho, Nd, Yb, and E
At least one of r, especially X, satisfies 0≦X≦0.
6, y is 0≦y≦0.2), MIIFX-xA
:yLn [However, M” is Ba, Ca, Sr, Mg,
At least one of Zn and Cd, A is Be0
1Mg01CaO1SrO1BaO1ZnO, Affi
203,Y2O,,La,03,In2O3,5in2
, TiO□, ZrO2, GeO□, SnO2, Nb2O
5, Ta2O, and ThO2, and Ln is Eu, Tb, Ce, or Tm.

Dy%Pr, Ha, Nd, Yb, Er, Sm
, and at least one of Gd, X is C1, Br
,and! at least -. species, X and y are respectively 5
≦0.2] A phosphor expressed by the composition formula, (Ba, -,,M eyes)F2・aBaX2:yEu,z
A[However, M'' is at least one of beryllium, magnesium, calcium, strontium, zinc, and cadmium, X is at least one of chlorine, bromine, and iodine, and A is at least one of zirconium and scandium. Yes, a, x, y, and 2 are each 0.5≦a≦1.25.0≦X≦1.1O
−6≦y≦2xlO−′, and O<z≦10]
A phosphor represented by the composition formula, (sa+-x, M''
) F2-aBaX2 :yEu, zB[However, M”
is at least one of beryllium, magnesium, calcium, strontium, zinc, and cadmium, X is at least one of chlorine, bromine, and iodine, and a, x, y, and 2 are O, S≦a, respectively. ≦
1.25.0≦X≦1.10-6≦y≦2×10-1
and a phosphor expressed by the composition formula 0<z≦2X10-"?'al], (Ba,,,M")F2 ・aBaX2 :yEu
, zA [However, M is at least one of beryllium, magnesium, calcium, strontium, zinc, and cadmium, X is at least one of chlorine, bromine, and iodine, and A is at least one of arsenic and silicon. and a, x, y, and Z are each 0.5≦a≦1.25.0≦X≦1.10 bow≦y≦2
x10-1 and O<z≦5xlO-'], M"' OX : xCe [However, Mn1 is Pr.

Nd, Pm, Sm, Eu, Tb, Dy% Ho, Er,
is at least one trivalent metal selected from the group consisting of Tm, Yb, and Bi; X is one or both of CIl and B; X is O<x
<0.1, a phosphor represented by the composition formula Bat-XM, 2L, 2FX: yEu'' [where M is at least one selected from the group consisting of Li, Na, Rh, and Cs. Represents a kind of alkali metal;
L is Sc, Y% La, Ce, PrNd, Pm, Sm
, Gd, Tb, Dy, Ho, Er, Tm, Yb,
represents at least one trivalent metal selected from the group consisting of Lu, All, Ga, In, and T1; X represents at least one halogen selected from the group consisting of Cll, Br, and ■; is 1O-2
≦X≦0.5y is o<y≦0.1] A phosphor represented by the composition formula BaFX-xA: yEu” [where X is C1
, Br, and I; zA is a fired product of a tetrafluoroboric acid compound; and X is 1O-6≦X≦0.1
, y is o<y≦o, i] is a phosphor represented by the composition formula Ba FX −xA : yEu” [where X is C
At least one halogen selected from the group consisting of IL, Br, and I, and zA is a hexafluoro compound group consisting of monovalent or divalent metal salts of hexafluorosilicic acid, hexafluorotitanic acid, and hexafluorozirconic acid. is a fired product of at least one compound selected from; and X is 10-6≦X≦0.1, y
is a phosphor represented by the composition formula BaFX-xNaX':aEu'' [where X and Xo are each at least one of C2, Br, and l; , X and a are each 0 < x
≦2, and O<a≦0.2], M"FX -xNaX':yEu": zA [where M" is from the group consisting of Ba, Sr, and Ca. at least one selected alkaline earth metal; X and Xo are at least one halogen metal selected from the group consisting of C1, Br, and
, cr, Mn, Fe, COl and Ni: and X is 0<x
≦2, y is o<y≦0.2, and z(dO<z≦10
-2] is a phosphor represented by the composition formula M"FX -aM'
cM"'X" -xA : yEu" [However,
M" is at least one alkaline earth metal selected from the group consisting of Ba, Sr, and Ca, and M 1
is at least one kind of alkali metal selected from the group consisting of Li, Na, Rh, and Cs; M'' is at least one divalent metal selected from the group consisting of Be and Mg: M'l ' is at least one trivalent metal selected from the group consisting of Al1, Ga, In, and Tffi; A is a metal oxide; X is CIL;
Br, and at least one halogen selected from the group consisting of I); X', X", and x" are F,
is at least one halogen selected from the group consisting of Cfi, Br, and ■; and a is 0≦a≦2
, b is 0≦b≦1O-2, C is 0≦C≦10-2 and a
+b+c≧10−6; X&i0<x≦0.5, y
is a phosphor represented by the composition formula: o<y≦0.2], where Ml is at least one selected from the group consisting of Ba, Sr, and Ca. are alkaline earth metals;
o is at least one kind of halogen selected from the group consisting of C1, Br, and ■, and X#X'; and a is 0.1≦a≦10.0, and X is 0<x≦0. A stimulable phosphor represented by the composition formula M"FX-aM'X':xEu" [where Ml
is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; Ml is at least one alkali metal selected from the group consisting of Rh and C5; X is C1, Br and I is at least one kind of halogen selected from the group consisting of;
At least one halogen selected from the group consisting of Cl3, Br and phosphor, M'; and X is 0<x≦
A stimulable phosphor represented by the composition formula [with a numerical value in the range of 0.2].

In addition, the following additives are added to the MIIX, -aM"X' 2 : xEu2+ stimulable phosphor.
It may be contained in the following proportions per 21 moles of aM's X'.

bM' Then b is o<
bSiO,0); bKX"-cMgX"-
dM"'X" (However, MIIl is Sc, Y, L
is at least one trivalent metal selected from the group consisting of a, Gd and Lu, and X'', X''° and X'' are all at least one halogen selected from the group consisting of F, C1, Br and ■. There is, and there is, cb and d
are respectively 0≦b≦2.0.0≦C≦2.0.0≦d
≦2.0 and 2×10-5≦b+c+d): yB (where y is 2XIO-'≦y≦2xlO
-'; bA (wherein A is an oxide of at least -M selected from the group consisting of S i 02 and P2O5, and b satisfies 10-4≦b≦2X10-'); bSiO (however, b is o<b≦3xlO-');bSnX" (however, x" is F, CIL
, Br, and I, where b is o<bSiO-3);bCsX''-csnX''' (where X'' and , Br and summer, and b and C are o<bSiO, 0 and 10, respectively.
−6≦C≦2×1O−2);bCsX″・yL
n3+ (However, X" is at least one kind of halogen selected from the group consisting of F, Cl3, Br and I, and Ln is Sc, Y, Ce, Pr, Nd, Sm, GdTb
, Dy, Ho, Er, Tm, Yb and Lu, and b and y are o<bSiO, 0 and 10, respectively.
-'≦y≦1.8×10−1).

Among the stimulable phosphors listed in section I, divalent europium-activated alkaline earth metal halide phosphors and cerium and/or terbium-activated rare earth oxyhalide phosphors exhibit high-intensity stimulated luminescence, so they are particularly preferred. preferable. However, the stimulable phosphor used in the present invention is not limited to the above-mentioned phosphors, and any phosphor that exhibits stimulated luminescence when irradiated with radiation and then irradiated with excitation light can be used. There may be.

When manufacturing the radiation image storage panel of the present invention, first, the photostimulable phosphor particles are dispersed in a solution containing a fluororesin that is soluble in an organic solvent, the solvent is removed, and the fluororesin is then dried. The phosphor particles are coated with a film containing resin.

Fluorine resins are polymers of olefins containing fluorine (fluoroolefins) or copolymers containing olefins containing fluorine as a copolymer component, such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride. , polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and fluoroolefin-vinyl ether copolymer.

Fluororesins are generally insoluble in organic solvents, but copolymers containing fluoroolefins as copolymer components are
Some structural units (other than fluoroolefins) to be copolymerized are soluble in organic solvents, so the phosphor particles are dispersed in a solution prepared by dissolving the resin in an appropriate solvent, and after removing the solvent, The phosphor can be easily coated by drying. An example of such a copolymer is a fluoroolefin-vinyl ether copolymer. In addition, polytetrafluoroethylene and its modified products are also soluble in suitable fluorinated organic solvents such as perfluorosolvents, so they can be prepared using the same method as for copolymers containing the above-mentioned fluoroolefins as a copolymer component. , the phosphor particles can be coated.

The film that covers the phosphor particles may contain resins other than fluororesin, and may also contain crosslinking agents, hardening agents, anti-yellowing agents, etc. as described below. . However, in order to fully achieve the above-mentioned objective, the content of the fluororesin in the coating is suitably 30% by weight or more, preferably 50% by weight or more,
Furthermore, it is preferably 70% by weight or more. Examples of resins other than fluorine-based resins contained in this coating include polyurethane resins, polyacrylic resins, cellulose derivatives, polymethyl methacrylate, polyester resins,
Examples include epoxy resins.

Furthermore, the fluororesin used in the present invention is preferably crosslinked, since this increases the strength of the resin and the durability of the coating.

Therefore, the fluororesin solution in which the above-mentioned phosphor particles are dispersed may contain a resin other than the fluororesin, a crosslinking agent, and the like, and may further contain an anti-yellowing agent.

Next, a phosphor layer is formed using phosphor particles coated with a film containing a fluororesin obtained by the above-described treatment.

The method for manufacturing the radiation image storage panel of the present invention will be described below, taking as an example the case where the phosphor layer is composed of a stimulable phosphor and a binder containing and supporting the stimulable phosphor in a dispersed state.

The phosphor layer can be formed on the support, for example, by the following method.

First, add the stimulable phosphor that has undergone the above treatment and a binder to a suitable solvent, mix them thoroughly, and prepare a coating solution in which the stimulable phosphor is uniformly dispersed in the binder solution. Prepare.

Examples of binders for the phosphor layer include proteins such as gelatin,
Polysaccharides such as dextran, or natural polymeric substances such as gum arabic; and polyvinyl butyral, polyvinyl acetate, nitrocellulose, ethylcellulose, vinylidene chloride/vinyl chloride copolymer, polyalkyl (meth)acrylate, vinyl chloride/vinyl acetate Binders typified by synthetic polymeric materials such as copolymers, polyurethanes, cellulose acetate butyrate, polyvinyl alcohol, linear polyesters, etc. may be mentioned. Particularly preferred among such binders are nitrocellulose, linear polyester,
These are polyalkyl (meth)acrylates, polyurethanes, mixtures of nitrocellulose and linear polyesters, and mixtures of nitrocellulose and polyalkyl (meth)acrylates.

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

The mixing ratio of 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 phosphor, etc., but generally the mixing ratio of the binder and the stimulable phosphor is 1. :1 to 1:100 (weight ratio), and particularly preferably from 1:8 to 1:40 (weight ratio).

The coating liquid also contains a dispersant to improve the dispersibility of the phosphor in the coating liquid, and a dispersant to improve the bonding force between the binder and the phosphor in the phosphor layer after formation. Various additives such as plasticizers may be mixed. Examples of dispersants used for such purposes include phthalic acid, stearic acid, caproic acid, lipophilic surfactants, and the like. Examples of plasticizers include phosphate esters such as triphenyl phosphate, tricresyl phosphate, and diphenyl phosphate; phthalate esters such as diethyl phthalate and dimethoxyethyl phthalate; ethyl phthalyl ethyl glycolate, butyl phthalyl glycolate, etc. 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 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 carried out using conventional coating means such as a doctor blade, roll coater, knife coater, etc.

The support can be arbitrarily selected from materials known as supports for conventional radiation image storage panels. Examples of such materials include films of plastic substances such as cellulose acetate, polyester, polyethylene terephthalate, polyamide, polyimide, triacetate, polycarbonate, metal sheets such as aluminum foil, aluminum alloy foil, regular paper, baryta paper, resin. Examples include coated paper, pigment paper containing pigments such as titanium dioxide, paper sized with polyvinyl alcohol, and plates or sheets of ceramics such as alumina, zirconia, magnesia, and titania.

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

Furthermore, in order to improve the sharpness of the obtained image, an adhesive layer, a light reflection layer, a light absorption layer, etc. are provided on the surface of the support on the phosphor layer side (the surface of the support on the phosphor layer side). microscopic irregularities may be formed on the surface.

After forming the coating film on the support-F 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 type of phosphor, the mixing ratio of the binder and the phosphor, and is usually 20 μm to 1 mm. However, the thickness of this layer is preferably 50 to 500 μm.

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

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

The transparent protective film may be made of a transparent material such as a cellulose derivative such as cellulose acetate or nitrocellulose; or a synthetic polymer material such as polymethyl methacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyvinyl acetate, or vinyl chloride/vinyl acetate copolymer. It can be formed by coating the surface of the phosphor layer with a solution prepared by dissolving a polymeric substance in an appropriate solvent. Or a plastic sheet made of polyethylene terephthalate, polyethylene naphthalate, polyethylene, polyvinylidene chloride, polyamide, etc.;
Alternatively, a protective film-forming sheet such as a transparent glass plate may be formed separately and adhered to the surface of the phosphor layer using a suitable adhesive.

The thickness of the protective film is generally in the range of about 0.1 to 20 μm.

In addition, for the purpose of improving the sharpness of the obtained image, at least one layer of the above-mentioned layers constituting the radiation image conversion panel of the present invention absorbs excitation light and does not absorb stimulated luminescence light. It may be colored with a coloring agent.

Examples and comparative examples of the present invention are described below. However, the present invention is not limited to this example.

[Example 1] Fluorine resin: fluoroolefin-vinyl ether copolymer (Lumiflon [, Floo] manufactured by Asahi Glass ■) 14
g, Crosslinking agent: Isocyanate (Sumitomo Bayer Urethane ■
5 g of Desmodur Z4370), toluene
Add isopropyl alcohol (l:1) mixed solvent,
A solution with a solid content concentration of 5 wt% was prepared. In this solution,
Stimulable phosphor: BaFBro, alo 2: o, oo
Add 200 g of "lEu" and mix with a propeller mixer for 20 g.
Stir for a minute. Furthermore, while rotating the propeller mixer, methyl alcohol, which is a non-solvent, was added into the propeller mixer at a rate of 0.
．． The mixture was added at a rate of 5 to 2 cc to precipitate the mixture of the fluororesin and crosslinking agent on the surface of the phosphor particles. The solvent was removed by vacuum filtration, and dried at 150 °C using a vacuum dryer.
Drying and heat curing were performed at °C.

200g of phosphor after this treatment, polyurethane resin (
Sumitomo Bayer Urethane Desmolac 4125) 1
5.8 g, bisphenol A epoxy resin 2.0 g
, was added to a mixed solvent of methyl ethyl ketone and toluene (1:1) and dispersed with a propeller mixer until the viscosity was 2.
Thirty-one coating solutions of 5 to 30 PS were prepared. After applying this coating liquid to the undercoat base using a doctor blade, 1
It was dried at 00° C. for 15 minutes to form a phosphor layer.

On top of this phosphor layer, a transparent polyethylene terephthalate film (10 μm thick) coated with an unsaturated polyester adhesive on one side to a thickness of 2 μm is glued with the adhesive side facing down. A transparent protective film was formed.

The radiation image conversion panel of the present invention was manufactured in the manner described above.

[Comparative Example 1] Example! A radiation image conversion panel was manufactured in the same manner as in Example 1 except that the phosphor was not subjected to any treatment.

[Example 2] To 400 g of a perfluorosolvent 5% solution of cofluorine-based resin: polytetrafluoroethylene modified product (Cytotsubu manufactured by Asahi Glass ■), a photostimulable ordinary photon: acIL Br:E was added.
200 g of phosphor particles were added and stirred for 20 minutes using a propeller mixer.Furthermore, while rotating the propeller mixer, isopropyl alcohol, which is a non-solvent, was added at a rate of 0.5 to 2 cc per second to dissolve the phosphor particles. The above fluororesin was deposited on the surface. This was passed through a vacuum port,
The solvent was removed and drying was performed using a vacuum dryer.

A radiation image conversion panel of the present invention was manufactured in the same manner as in Example 1 using 200 g of the phosphor that had undergone this treatment.

[Comparative Example 2] A radiation image conversion panel was manufactured in the same manner as in Example 2, except that no treatment was applied to the phosphor.

Ridge straightness 1 The following moisture resistance test was conducted on the panels of Examples 1 and 2 and Comparative Examples 1 and 2.

That is, after irradiating with X-rays, the amount of stimulated luminescence when excited by a He-Ne laser was compared before and after each panel was left for one week at 60° C. and 80% relative humidity.

The results are shown in Table 1. However, in Table 1, the numerical values are relative values with the sensitivity before being left as 100.

All mills below

Claims (2)

[Claims] 1. A radiation image storage panel comprising photostimulable phosphor particles coated with a film containing a fluororesin soluble in an organic solvent. 2. a) Forming a coating layer of an organic solvent solution containing a resin containing a fluororesin in a dissolved state on the surface of the stimulable phosphor particles; b) Drying the obtained solution-coated particles to Step of obtaining phosphor particles with a resin-containing resin coating layer: c) Mixing the obtained phosphor particles with a resin coating layer with a binder resin-containing solution to prepare a phosphor coating liquid: d) A method for producing a radiation image conversion panel, comprising the steps of: coating a phosphor coating liquid on a support and then drying it.