JP2002006091A - Radiation image conversion panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation image conversion panel having antifouling property similar to the initiation of use even after repeated use and superior in carriage durability and anti-scratch capability. SOLUTION: In a radiation image conversion panel having a phosphoric layer consisting of stimulable phosphor and a protection layer, the protection film contains particles of 0.1 μm to 1 μm on the average and Mohs' hardness of 9 and contains particles of 50 to 200 wt.% to the resin.

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 for a radiation image conversion method 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 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. And then stimulating the stimulable phosphor with electromagnetic waves (excitation light) such as visible light and infrared light in a time-series manner, so that the radiation energy accumulated in the stimulable phosphor is (Stimulated emission light), and the fluorescence is photoelectrically read to obtain an electric signal.
Then, a radiation image of the subject or the subject is reproduced as a visible image based on the obtained electric signal. The panel after reading is prepared for the next photographing after the remaining image is erased. 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 a radiographic film for each photographing operation, this radiographic image conversion method uses a radiographic image conversion panel repeatedly, which is advantageous in terms of resource conservation and economic efficiency. It is.

A radiation image conversion panel used in a radiation image conversion method generally comprises a support and a stimulable phosphor layer provided on the surface thereof, and further comprising a phosphor layer provided on the surface of the phosphor layer, which is formed by chemical treatment. And a protective film that protects against excessive deterioration or physical impact. The protective film 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 terephthalate. An organic polymer film such as an organic polymer film or a sheet for forming a protective film such as a transparent glass plate is separately formed and provided on the surface of the phosphor layer using an appropriate adhesive, or an inorganic compound is deposited on the phosphor layer by vapor deposition or the like. A film formed thereon is known. Among these, the protective film formed by coating generally has the advantage that the adhesive strength to the phosphor layer is strong and that it can be manufactured by a relatively simple process.

In the practice of the radiation image conversion method, the radiation image conversion panel includes radiation irradiation (recording of a radiation image) and irradiation of excitation light (reading of a recorded radiation image).
・ It is repeatedly used in the cycle of irradiating erasing light (erasing the remaining radiation image). The transition to each step of the panel is performed by conveyor means such as belts and rollers. After one cycle, the panels are usually laminated and stored. Is done. However, as described above, when a radiation image conversion panel having a protective film formed by coating is repeatedly used in this way, for example, because the protective film surface is stained or scratched, The image quality of the radiation image formed by the radiation image conversion panel tends to gradually decrease.
As with the conventional radiographic method, it is desired that the radiation image conversion panel also provides an image with high sensitivity and good image quality (sharpness, granularity, etc.). Preventing adhesion and abrasion is an important issue.

As a panel which can prevent the sensitivity of the radiation image conversion panel from being lowered due to the repeated use, the present applicant has already disclosed a radiation image conversion panel having a protective film containing a fluorine-based resin soluble in an organic solvent. (Patent No. 2540370). Further, as a radiation image conversion panel with further improved antifouling properties, a radiation image having a protective film formed by further adding a reactive silicone (polysiloxane skeleton-containing oligomer) to the above-mentioned organic solvent-soluble fluororesin. A conversion panel is disclosed (Japanese Patent No. 2715)
189).

[0007]

However, by using a reactive silicone in combination with an organic solvent-soluble fluororesin, the antifouling property in the initial stage of use is improved, but the reactive silicone is protected by repeated use of the panel. It was found that it was gradually removed from the layer surface, and the antifouling property gradually decreased. It is known that the inclusion of white fine particles in the protective film to cause light scattering is effective for preventing rainbow unevenness of the coating film (Japanese Patent Application Laid-Open No. 62-247298,
JP-A-10-123297) does not show any improvement in antifouling property and scratch resistance even by such a method, and it is difficult to obtain a protective film having the same antifouling property as the initial use after repeated use.

The present invention has been made in view of the above circumstances, and provides a radiation image conversion panel which has the same antifouling property as the initial use even after repeated use, and has excellent transport durability and scratch resistance. It is intended for.

[0009]

A radiation image conversion panel according to the present invention is a radiation image conversion panel having a phosphor layer comprising a stimulable phosphor and a protective film, wherein the protective film is made of resin and Mohs hardness of 9 or more. And particles having an average particle diameter of 0.1 μm to 1 μm, and the particles are contained in an amount of 50% by weight to 200% by weight based on the resin.

[0010] Mohs hardness is defined as talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, yellow ore, steel ball,
It is an empirical measure for determining the hardness of a mineral by comparing diamonds (diamond = 10) in order with ten types of reference minerals, and a Mohs hardness of 9 or more means a hardness equal to or higher than a steel ball. The particles are 4
More preferably, it contains 0 to 120% by weight.

[0011] Preferably, said particles are alumina.
The alumina is a single crystal, and the weight of the particle size distribution is high.
10% particle size D in the cumulative amount curve_TenAnd 90% particle size D₉₀Ratio (D
₉₀/ D _TenIs more preferably 3 or less monodisperse particles.
New Single crystal means that all parts have the same crystallographic orientation
It means that it has. Weight accumulation of particle size distribution
The product curve is the weight accumulation (%) on the vertical axis and the particle size on the horizontal axis.
Is a curve in which 10% of the curve
Particle size D_TenAnd 90% particle size D₉₀Ratio (D₉₀/ D_Ten) Is 3 or less
Means monodispersed particles.

Preferably, the resin is a fluorine-based copolymer resin and / or a silicone-based copolymer resin. It is preferable that the protective film further contains a reactive silicone.

[0013] The protective film may be provided directly on the phosphor layer, or a transparent film may be provided between the protective film and the phosphor layer.

[0014]

According to the radiation image conversion panel of the present invention, the protective film is made of a resin and Mohs hardness of 9 or more and has an average particle size of 0.1 μm to 1 μm
And 50% to 200% by weight of the resin, so that the protective film can have improved scratch resistance and transport durability. In addition, since the protective film is not easily damaged even after repeated use, the antifouling property at the beginning of use (the property that dirt is difficult to adhere and / or the property that once adhered dirt is easily removed by washing with an organic solvent or the like). It is possible to maintain Further, since the protective film has good antifouling properties, scratch resistance, and durability, it is possible to maintain sensitivity comparable to that at the initial stage of panel use and good image quality even after repeated use of the radiation image storage panel.

[0015] Incidentally, the particles are added in an amount of 40% by weight to 1% with respect to the resin.
By containing 20% by weight, antifouling property, scratch resistance,
The durability can be further improved.

Further, the particles are made of alumina, especially single crystal, and have a particle diameter D ₁₀ of 10% in a weight cumulative curve of the particle size distribution.
The use of alumina, which is a monodisperse particle having a 90% particle diameter D ₉₀ ratio (D ₉₀ / D ₁₀ ) of 3 or less, has good dispersibility in resin and improves surface smoothness when a protective film is formed. Therefore, the sensitivity of the radiation image conversion panel can be increased and the image quality can be improved.

Further, by making the resin a fluorine-based copolymer resin and / or a silicone-based copolymer resin, the antifouling property can be further improved. A radiation image conversion panel having high sensitivity can be obtained. Further, by including the reactive silicone in the protective film, the same antifouling property as in the early stage of use can be maintained for a longer time even after repeated use.

When the protective film is provided directly on the phosphor layer, a radiation image conversion panel having good light emission can be obtained. Further, when a transparent film is provided between the protective film and the phosphor layer, a radiation image conversion panel having more excellent durability can be obtained.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the radiation image conversion panel of the present invention will be described in more detail. The radiation image conversion panel of the present invention is characterized in that the protective film contains a resin and particles having a Mohs hardness of 9 or more and an average particle diameter of 0.1 μm to 1 μm, and the particles contain 50% to 200% by weight based on the resin. Features. The resin that can be used in the present invention can be any resin as long as it is a transparent resin that is soluble in an organic solvent when not cured, such as a polyurethane resin, a polyacryl resin, a cellulose derivative, polymethyl methacrylate,
Examples include polyester resins and epoxy resins. In order to obtain a radiation image conversion panel with higher sensitivity, the resin used preferably has a light transmittance of at least 90%, more preferably at least 95%, at a wavelength of 350 nm to 900 nm.

Particularly, a fluorine-based copolymer resin or a silicone-based copolymer resin is preferable because of its excellent antifouling property and transparency. The fluororesin copolymer resin is a copolymer of a fluorine-containing ethylene-based monomer and another copolymerizable monomer or oligomer and is soluble in an organic solvent when not cured. The silicone copolymer resin is a copolymer having a silicone chain in a main chain or a side chain and soluble in an organic solvent when not cured. Among them, it is more preferable to use a copolymer resin having a silicone chain in a side chain and a fluorine-based copolymer resin having a silicone chain.

As a specific example of the fluorine-based copolymer resin which is soluble in an organic solvent when not cured, Lumiflon series manufactured by Asahi Glass Co., Ltd. is preferable, and specifically LX-100 (hereinafter LX- is omitted). 200, 210Y, 400, 504X, 600X, 710N, 800, 8
10Y, 906N, 916N, 924N, 966N, 986N, 216T, 600, 72
2, 800, 810, 9010, 916, 924, 936, 946, 966, 976 and the like. Of these, 400, 504X, 600X, 7
10N, 216T, 810, 9010 and the like are more preferable.

It is more preferable that the fluorine-based copolymer resin soluble in the organic solvent is used in combination with a polyisocyanate, melamine, a UV crosslinking agent or the like, and is cured after forming the coating film.

Specific examples of the silicone copolymer resin which is soluble in an organic solvent when not cured include Reseda GS-1015 manufactured by Toagosei Co., Ltd., Cymac US-350, US-380 as a silicone graft copolymer. , US-270, US-352, OPSR JN7 manufactured by JSR Corporation as a silicone copolymerized fluorine resin
220 and the like can be particularly preferably mentioned.

The particles contained in the protective film have a Mohs hardness (diamond = 10) of 9 or more, and the average particle size is from 0.1 μm.
1 μm. If the Mohs' hardness is less than 9, especially 7 or less, the effect of durability due to the addition of particles cannot be obtained. The average particle size is
If it is less than 0.1 μm, the antifouling property after repeated use is reduced, and if it is more than 1 μm, the surface of the protective layer becomes coarse and dirt easily adheres, which is not preferable. 50% to 200%, or even 40% by weight of such particles based on the resin
To 120% by weight.

The particles are more preferably single crystal alumina, and specific examples thereof include HIT-100 manufactured by Sumitomo Chemical Co., Ltd.
(0.2 μm), HIT-50 (0.3 μm), AKP-50 (0.2 μm), AKP-30
(0.4 μm), AKP3000 (0.5 μm), AKP-20 (0.5 μm), AKP-15
(0.7 μm), Sumicorundum AA-04 (0.4 μm), AA-05 (0.5 μm)
m), AA-07 (0.7 μm), AES-11 (0.5 μm), AES-12 (0.5 μm)
m), AES-21 (0.9 μm), A33F (0.7 μm) manufactured by Showa Denko KK
m), LS-23 (0.4 μm), LS-231 (0.5 μm), LS-250 (0.5 μm)
And the like (the average particle size in parentheses).

Of these aluminas, the weight of the particle size distribution
In the amount accumulation curve, the particle size D of 10% _TenAnd 90% particle size D₉₀
D which is the ratio of₉₀/ D_TenIs preferably 3 or less.
The narrow particle size distribution (monodisperse particles)
With this, the dispersibility of the particles in the resin is increased, and the protective film is formed.
To further improve the flatness of the coating film surface when forming
Can be. Among the above resins, Sumicorundum series
Is a monodisperse, single-crystal alumina.
Is more preferable.

The protective film of the present invention may further contain a conventionally known silicone oil or wax.
More preferably, it comprises a reactive silicone (eg, as described in Patent 271589). By adding such silicone, the antifouling property of the resin can be further enhanced.

Hydroxyl-modified silicone is particularly preferred as the reactive silicone. Specific examples include KF-851, KF-6001, KF-6002, KF-6003, and X22-16 manufactured by Shin-Etsu Chemical Co., Ltd.
0AS, X22-2809, Silaplane FM-332 manufactured by Chisso Corporation
5, FM-4425, FM-DA26 and the like can be preferably used. The amount added to the resin is preferably 0.01 to 10% by weight, more preferably 0.1 to 3% by weight.

The protective film of the radiation image storage panel of the present invention comprises:
A protective film forming material coating liquid containing a resin and particles, and, if necessary, a reactive silicone (which may further contain a crosslinking agent, a hardening agent, an anti-yellowing agent, and the like), is subjected to an extrusion coater, a slide coater, The transparent support or the phosphor layer surface is directly and uniformly coated and dried by using a coating means such as a doctor coater, a bar coater, and a dip coater. When a protective film is applied on a support and then attached on the phosphor layer, polyethylene terephthalate (PET), which is highly transparent and can be obtained at low cost, is more preferable. The formation of this protective film may be performed simultaneously with the formation of the phosphor layer by simultaneous multilayer coating. The thickness of the protective film is preferably about 0.5 to 10 μm, more preferably about 1 to 5 μm.

Next, the stimulable phosphor constituting the 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 radiation and then irradiated with excitation light as described above, but the wavelength is in the range of 400 to 900 nm from a practical viewpoint. By the excitation light
It is desirable that the phosphor exhibit stimulable emission in the wavelength range of 300 to 500 nm.

Used in the radiation image conversion panel of the present invention
An example of a stimulable phosphor is disclosed in U.S. Pat. No. 3,859,527.
SrS: Ce, Sm, SrS: Eu, Sm, ThO described in the detailed document_Two: E
r, and La_TwoO_TwoS: Eu, Sm, described in JP-A-55-12142
ZnS: Cu, Pb, BaOxAl_TwoO_Three: Eu (0.8 ≦ x ≦
10) and M^IIOxSiO_Two: A (but M^IIIs Mg, C
a, Sr, Zn, Cd, or Ba, and A is Ce, Tb, Eu, Tm,
Pb, Tl, Bi or Mn, and x is 0.5 ≦ x ≦ 2.5.
Described in JP-A-55-12143 (Ba_1-Xy, Mg
_X, Ca_y) FX: aEu²⁺(However, X is a small number of Cl and Br
X and y are 0 <x + y ≦ 0.6,
Xy ≠ 0, and a is 10^-6≦ a ≦ 5 × 10^-2),
LnO described in JP-A-55-12144_X: xA (just
And Ln is at least one of La, Y, Gd, and Lu.
Species, X is at least one of Cl and Br, A is Ce and
And at least one of Tb and x is 0 <x
<0.1), described in JP-A-55-12145 (Ba
_1-X, M²⁺ _X) FX: yA (However, M²⁺Are Mg, Ca, Sr, Zn, and
X is Cl, Br, and at least one of Cd and Cd.
At least one of them, A is Eu, Tb, Ce, Tm, Dy, Pr,
At least one of Ho, Nd, Yb, and Er, and
x is 0 ≦ x ≦ 0.6, and y is 0 ≦ y ≦ 0.2).
M described in -160078^IIFX xA: yLn (however, M
^IIIs at least one of Ba, Ca, Sr, Mg, Zn, and Cd
One kind, A is BeO, MgO, CaO, SrO, BaO, ZnO, Al_TwoO_Three, Y
_TwoO_Three, La_TwoO_Three, In_TwoO_Three, SiO_Two, TiO_Two, ZrO_Two, GeO_Two, SnO_Two, N
b_TwoO_Five, Ta_TwoO _Five, And ThO_TwoAt least one of the Ln
Are Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Sm, and
And Gd, wherein X is Cl, Br, and I
X and y are each at least one of
× 10^-Five≤ x ≤ 0.5 and 0 <y ≤ 0.2)
Phosphor represented by, described in JP-A-56-116777
(Ba_1-X, M^II _X) F_Two・ ABaX_Two: yEu, zA (where M^IIIs beli
Lium, magnesium, calcium, strontium,
X is at least one of zinc and cadmium.
At least one of chlorine, bromine and iodine, A
Is at least one of zirconium and scandium
A, x, y, and z are each 0.5 ≦ a
≤1.25, 0≤x≤1, 10^-6≦ y ≦ 2 × 10^-1, And 0
<Z ≦ 10^-2Phosphor represented by the composition formula
No. 57-23673 (Ba_1-X, M^II _X) F_Two・ ABaX_Two:
yEu, zB (where M^IIIs beryllium, magnesium, mosquito
Of calcium, strontium, zinc, and cadmium
X is chlorine, bromine, and iodine
A, x, y, and z
Are 0.5 ≦ a ≦ 1.25, 0 ≦ x ≦ 1, 10^-6≦ y ≦ 2 ×
Ten^-1, And 0 <z ≦ 10^-2Is represented by the composition formula
Phosphor described in JP-A-57-23675 (Ba_1-X, M
^II _X) F_Two・ ABaX_Two: yEu, zA (where M^IIIs beryllium, ma
Gnesium, calcium, strontium, zinc, and
X is chlorine or odor
A is at least one of arsenic and iodine;
And at least one of silicon and a, x, y,
And z are 0.5 ≦ a ≦ 1.25, 0 ≦ x ≦ 1, 10^-6
≦ y ≦ 2 × 10^-1, And 0 <z ≦ 5 × 10^-1Is the composition of
Phosphor represented by the formula, described in JP-A-58-69281
M^IIIOX: xCe (where M^IIIIs Pr, Nd, Pm, Sm, E
From the group consisting of u, Tb, Dy, Ho, Er, Tm, Yb, and Bi
X is at least one selected trivalent metal, and X is Cl and
And / or Br, and x
Is 0 <x <0.1), a phosphor represented by a composition formula:
Ba described in JP-A-58-206678_1-XM_{X / 2}L_{X / 2}FX:
yEu²⁺(However, M consists of Li, Na, K, Rb, and Cs
Represents at least one alkali metal selected from the group
L is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, D
y, Ho, Er, Tm, Yb, Lu, Al, Ga, In, and Tl.
Represents at least one trivalent metal selected from the group consisting of
X is at least one selected from the group consisting of Cl, Br, and I
Both represent a kind of halogen; and x is 10^-2≦ x ≦
0.5, y is 0 <y ≦ 0.1).
Optical body, BaFXxA: yEu described in JP-A-59-27980
²⁺(Where X is selected from the group consisting of Cl, Br and I)
Is at least one halogen; A is tetra
A calcined product of a fluoroborate compound; and x is 10
^-6≦ x ≦ 0.1, y is 0 <y ≦ 0.1)
Phosphor, BaF described in JP-A-59-47289
X ・ xA: yEu²⁺(Where X consists of Cl, Br, and I
At least one halogen selected from the group; A is
Hexafluorosilicic acid, hexafluorotitanic acid and
Monovalent or divalent metal hexafluorozirconate
Selected from the group of hexafluoro compounds consisting of salts of
A calcined product of at least one compound; and x is 10
^-6≦ x ≦ 0.1, y is 0 <y ≦ 0.1)
The phosphor described, Ba described in JP-A-59-56479
FXxNaX ': aEu²⁺(However, X and X 'are each C
at least one of l, Br, and I;
And a are 0 <x ≦ 2 and 0 <a ≦ 0.2, respectively.
Phosphor) represented by the composition formula of JP-A-59-56480.
M listed^IIFX ・ xNaX ′: yEu²⁺: zA (where M^II
Is at least selected from the group consisting of Ba, Sr, and Ca
Are also alkaline earth metals; X and X '
Each selected from the group consisting of Cl, Br, and I
A is V, Cr, Mn, Fe, Co,
And at least one transition metal selected from Ni and Ni.
And x is 0 <x ≦ 2, y is 0 <y ≦ 0.2, and
z is 0 <z ≦ 10^-2Is the fluorescence represented by the composition formula
M, described in JP-A-59-75200^IIFX ・ aM^IX ′
・ BM ′^IIX ″_Two·cm^IIIX_Three・ XA: yEu²⁺(However, M^IIIs Ba, S
r, and at least one selected from the group consisting of Ca
An alkaline earth metal; M^IIs Li, Na, K, Rb and C
at least one alkali gold selected from the group consisting of s
Genus; M '^IIIs selected from the group consisting of Be and Mg
At least one divalent metal; M^IIIIs Al, Ga, I
at least one selected from the group consisting of n and Tl
A is a metal oxide; X is Cl, Br, and
At least one halogen selected from the group consisting of
X ′, X ″, and X represent F, Cl, Br, and I
At least one halogen selected from the group consisting of
A is 0 ≦ a ≦ 2, b is 0 ≦ b ≦ 10^-2, C is
0 ≦ c ≦ 10^-2, And a + b + c ≧ 10^-6X is 0 <x
≦ 0.5, y is 0 <y ≦ 0.2)
Phosphor described in JP-A-60-84381^IIX_Two・ AM
^IIX ′_Two: xEu²⁺(However, M^IIIs from Ba, Sr and Ca
At least one alkaline earth metal selected from the group consisting of
Yes; X and X 'are selected from the group consisting of Cl, Br and I
X ≠ X '
And a is 0.1 ≦ a ≦ 10.0, x is 0 <x ≦ 0.2
Stimulable phosphor represented by the composition formula of JP-A-60-1
M described in 01173^IIFX ・ aM^IX ′: xEu²⁺(However
Then M^IILess selected from the group consisting of Ba, Sr and Ca
Is a kind of alkaline earth metal; M^IIs Rb and Cs
At least one alkali metal selected from the group consisting of
X is a member selected from the group consisting of Cl, Br and I
At least one halogen; X ′ is F, Cl, Br and
At least one halogen selected from the group consisting of I
And a and x are each 0 ≦ a ≦ 4.0 and
0 <x ≦ 0.2) stimulable fluorescence represented by the composition formula
, M described in JP-A-62-25189^IX: xBi (ta
But M^IIs selected from the group consisting of Rb and Cs
Are a kind of alkali metal; X is from Cl, Br and I
At least one halogen selected from the group consisting of:
And x is a numerical value in the range of 0 <x ≦ 0.2)
Stimulable phosphors represented by
You.

LnOX: xCe described in JP-A-2-229882 (where Ln is at least one of La, Y, Gd and Lu, X is at least one of Cl, Br and I, x Is 0 <x ≦ 0.2, and the ratio between Ln and X is 0.500 in atomic ratio.
<X / Ln ≦ 0.998, and a cerium-activated rare earth oxyhalide phosphor represented by a stimulable excitation spectrum having a maximum wavelength λ of 550 nm <λ <700 nm.

It should be noted, M are described in JP Sho _{^{60-84381 II X 2 · aM II X}} '2: The xEu ²⁺ stimulable phosphor, additives such as shown below M ^II X ₂ · aM ^II X ′ ₂ may be contained in the following ratio per 1 mol.

BM described in JP-A-60-166379
^IX "(M^IIs selected from the group consisting of Rb and Cs
X ″ is F, C
at least one selected from the group consisting of l, Br and I
And b is 0 <b ≦ 10.0);
BKX ″ .cMgX described in JP-A-60-221483_Two・ DM
^IIIX ′_Three(However, M^IIIIs Sc, Y, La, Gd and Lu
At least one trivalent metal selected from the group consisting of
X ″, X and X ′ are all F, Cl, Br and I
At least one halogen selected from the group consisting of
And b, c and d are each 0 ≦ b ≦ 2.0,
0 ≦ c ≦ 2.0, 0 ≦ d ≦ 2.0, and 2 × 10^-Five≤b + c
+ d); yB described in JP-A-60-228592
However, y is 2 × 10^-Four≦ y ≦ 2 × 10^-1JP-A-60-2
BA described in No. 28593 (where A is SiO _TwoAnd P_Two
O_FiveAt least one oxide selected from the group consisting of
And b is 10^-Four≦ b ≦ 2 × 10^-1JP-A-61-
BSiO described in No. 120883 (where b is 0 <b ≦ 3
× 10^-2BS described in JP-A-61-120885
nX ″_Two(However, X "is a group consisting of F, Cl, Br and I
At least one selected halogen, and b
Is 0 <b ≦ 10^-3); Described in JP-A-61-235486.
BCsX ″ ・ cSnX_Two(However, X ″ and X are respectively
At least selected from the group consisting of F, Cl, Br and I
Are also a kind of halogen, and b and c are each
0 <b ≦ 10.0 and 10^-6≦ c ≦ 2 × 10^-2In
BCs described in JP-A-61-235487
X ″ ・ yLn³⁺(Where X ″ is composed of F, Cl, Br and I
Ln is at least one halogen selected from the group
Sc, Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb
At least one rare earth selected from the group consisting of
And b and y are each 0 <b ≦
10.0 and 10^-6≦ y ≦ 1.8 × 10^-1Is).

Of the above-described stimulable phosphors, a divalent europium-activated alkaline earth metal halide-based phosphor and a cerium-activated rare earth oxyhalide phosphor are particularly preferable 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 the stimulable phosphor in a dispersed state but also containing no stimulable phosphor. It may be composed of only a stimulable phosphor aggregate or a phosphor layer in which a polymer substance is impregnated in a gap between the stimulable phosphor aggregates.

Next, the method for producing the radiation image storage panel of the present invention will be described by 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 : 1 to 1: 100 (weight ratio)
It is particularly preferable to select 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, as described in JP-A-58-200200, in order to improve the sharpness of the obtained image, the surface of the support on the phosphor layer side (adhesive When an application layer, a light reflection layer, a light absorption layer, or the like is provided, the surface thereof means fine irregularities. After forming a coating on the support as described above, the coating is dried to complete the formation of the stimulable phosphor layer on the support. The thickness of the phosphor layer varies depending on the desired characteristics of the radiation image conversion panel, the kind of the phosphor, the mixing ratio between the binder and the phosphor, and is usually 20 μm to 1 mm. However, this layer thickness
It is preferably 50 to 500 μm. The stimulable phosphor layer does not necessarily need to be formed by directly applying a coating solution on the support as described above. For example, a separate sheet such as a glass plate, a metal plate, or a plastic sheet may be used. After the phosphor layer is formed by applying a coating solution on the substrate and drying, the phosphor layer is pressed onto the support, or the support and the phosphor layer are joined by using an adhesive or the like. Is also good.

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). Hereinafter, examples of the present invention will be described. However, these embodiments do not limit the present invention.

[0041]

EXAMPLES (Example 1) First, a phosphor layer was manufactured. As a coating solution for forming a phosphor sheet, a phosphor (BaFBr _0.85 I
_0.15 : Eu ²⁺ ) 1000 g, polyurethane elastomer as a binder (Dainippon Ink and Chemicals, Pandex T-52)
65H (solid) 35.5 g, polyisocyanate (Nippon Polyurethane Industry Co., Ltd., Coronate HX (solid content 100
%)) 4.5 g, 10 g of an epoxy resin (Yuika Shell Epoxy, Epicoat # 1001 (solid)) as a yellowing inhibitor, 0.02 g of ultramarine (Daiichi Kasei Kogyo Co., Ltd., SM-1) as a colorant Was added to a mixed solvent of methyl ethyl ketone / toluene = 7/3 and dispersed for 3 hours with a disper to prepare a coating solution having a viscosity of 3 Pa · s (25 ° C.). A polyethylene terephthalate sheet coated with a silicone release agent (temporary support,
(Thickness: 180 μm) was applied by an extrusion coater, dried, and then peeled off from the temporary support to prepare a phosphor sheet (sheet thickness: 300 μm).

Next, a reflective material layer was formed. 350 g of gadolinium oxide (Gd ₂ O ₃ ) fine particles (90% by weight of all particles having a particle diameter in the range of 1 to 5 μm), and a soft acrylic resin as a binder (Dainippon Ink & Chemicals, Inc.) ),
Chris Coat P-1018GS (20% toluene solution) 1800g, phthalic acid ester as plasticizer (Dahachi Chemical Co., # 10) 40
g, ZnO whisker (Matsushita Amtech Co., Ltd.)
120 g of Panatetra A-1-1) and 2 g of ultramarine blue (Daiichi Kasei Kogyo Co., Ltd., SM-1) as a colorant were added to methyl ethyl ketone, and dispersed and dissolved using a disper. 0.5Pa · s: 20 ° C), polyethylene terephthalate sheet (Toray, Lumirror S-10, 250μm; haze degree (typical) = 20, carbon black, silica on one side,
Using an extrusion coater, apply evenly on the light-shielding layer made of a binder (approximately 18 μm) on the opposite side from the light-shielding layer. A reflective material layer was formed to have a thickness of 20 μm.

Subsequently, the phosphor sheet and the support having a reflective material layer were superposed on each other, and a calender roll was used.
a, Continuously performed at an upper roll temperature of 75 ° C, a lower roll temperature of 75 ° C, and a feed speed of 1.0 m / min. By this heat compression, the phosphor sheet became a phosphor layer (layer thickness: 210 μm) completely fused to the support via the reflective material layer.

Next, a protective layer was formed. 185 Fluoroolefin-vinyl ether copolymer (Lumiflon LF-504X (30% xylene solution) as a fluororesin)
g, alumina (Sumicorundum AA-05, manufactured by Sumitomo Chemical Co., Ltd.)
39 g of an average particle size: 0.5 μm) and 0.2 g of acetoalkoxyaluminum diisopropylate (Ajinomoto Co., Inc., Prenact AL-M) as a dispersant were added to 100 g of methyl ethyl ketone, and the resulting mixture was used as a 3 mmφ zirconia ball. After dispersing and mixing in a ball mill for 24 hours, 0.5 g of a modified polysiloxane wax (manufactured by Shin-Etsu Silicone Co., Ltd .: X22-2809),
Dibutyltin dilaurate (Kyodo Yakuhin, K
S1260) 0.7mg, polyisocyanate (Sumitomo Bayer Urethane Co., Ltd., Sumidur N3500 (solid content 100
%)) 10 g and methyl ethyl ketone were additionally mixed so that the viscosity became 3 mPa · s to prepare a coating solution. After applying this coating solution to the 9 μm PET film surface with a bar coater,
Heat treatment was performed at 20 ° C. for 20 minutes, followed by drying and thermosetting. The thickness of the coating after drying was about 1 μm. Subsequently, the heat-resistant re-peelable film is peeled off from the 9 μm-thick PET film provided with the coating layer, and a polyester resin solution (Toyobo Co., Ltd., Byron 30SS) is applied and dried on the opposite side of the coating layer. (Adhesive application weight 2 g / m ² ). Using a laminate roll, the PET film is bonded to the phosphor layer via an adhesive layer to form a protective layer, and an embosser having a roughness Ra of 0.4 μm is formed on the protective layer with an embossing machine. I attached.

Next, a back protective layer was provided. 20 μm thick O
PP film (Toray Co., Ltd., Trefan YM-11 # 20) and unsaturated polyester resin solution (Toyobo Co., Ltd., Byron 30S)
S) is applied and dried to form an adhesive layer (adhesive applied weight 9g / m ² )
Was provided. The OPP film is laminated on a side opposite to the side on which the phosphor layer of the support is provided by using a laminating roll.
On the (light-shielding layer side), a back protective layer was formed by bonding via an adhesive layer.

Subsequently, a side edge bonding layer was provided. Silicone polymer (Polyurethane having polydimethylsiloxane unit; Dainichi Seika Co., Ltd., Dialomer SP-3023 (15%
Methyl ethyl ketone / toluene solution) 70 g, polyisocyanate as a crosslinking agent (Dainichi Seika Co., Ltd.
-70 (50% solution)) 3g, epoxy resin as yellowing inhibitor (Yuka Kasper Epoxy Co., Epicoat # 1001 (solid))
0.6 g, alcohol-modified silicone (Shin-Etsu Chemical Co., Ltd., X-22-2809 (66% xylene-containing paste)) 0.2 g as a slipping agent
Was dissolved in 15 g of methyl ethyl ketone to prepare a coating solution. This coating solution is applied to each side of the phosphor sheet provided with the protective layer prepared above, and dried sufficiently at room temperature.
A side cured film having a thickness of about 25 μm was formed. As described above, a radiation image storage panel with a protective layer, the top and side surfaces of which were protected, was manufactured.

Example 2 A radiation image conversion panel was manufactured in the same manner as in Example 1 except that the amount of alumina (Sumicorundum AA-05) used for the protective layer was changed to 52 g.

Example 3 A radiation image conversion panel was manufactured in the same manner as in Example 1 except that the amount of alumina (Sumicorundum AA-05) used for the protective layer was changed to 65 g.

Example 4 A radiation image conversion panel was manufactured in the same manner as in Example 1 except that the amount of alumina (Sumicorundum AA-05) used in the protective layer was changed to 88 g.

Example 5 Alumina used for the protective layer was replaced with Sumicolaund AA-07 (manufactured by Sumitomo Chemical Co., Ltd., average particle size: 0.7 μm).
m), and the radiation image conversion panel was manufactured in the same manner as in Example 1 except that the amount was changed to 52 g.

(Example 6) The alumina used for the protective layer was changed to AK
A radiation image conversion panel was manufactured in the same manner as in Example 1, except that P20 (manufactured by Sumitomo Chemical Co., Ltd., average particle size: 0.5 μm) and the amount was 52 g.

(Example 7) The alumina used for the protective layer was AK
A radiation image conversion panel was manufactured in the same manner as in Example 1 except that P30 (manufactured by Sumitomo Chemical Co., Ltd., average particle size: 0.4 μm) and the amount was 52 g.

(Example 8) The alumina used for the protective layer was changed to AK
A radiation image conversion panel was manufactured in the same manner as in Example 1, except that P50 (manufactured by Sumitomo Chemical Co., Ltd., average particle size: 0.2 μm) and the amount was 52 g.

(Example 9) A silicone-based copolymer resin (Reseda GS-1015 (manufactured by Toagosei Co., Ltd.) was used instead of Lumiflon LF504X, which is a fluorine-based copolymer resin used for the protective layer in Example 1. A radiation image conversion panel was produced in the same manner as in Example 1 except that 123.3 g of a 45% propylene glycol methyl ether acetate solution) was used.

Example 10 Fluorine-based copolymer resin (Lumiflon LF504X (30% xylene solution) manufactured by Asahi Glass Co., Ltd.) 185
g, 52 g of alumina (Sumicorundum AA-05), aluminum coupling agent as a dispersant (Ajinomoto Co., Inc., Prenact AL)
-M) Add 0.2g to 100g of toluene / hexane = 5/5 solvent and add 3m
After dispersing and mixing in a ball mill using mφ zirconia balls for 24 hours, 0.5 g of a modified polysiloxane wax (manufactured by Shin-Etsu Silicone Co., Ltd .: X22-2809), 0.7 g of dibutyltin dilaurate (Kyodo Yakuhin Co., Ltd., KS1260) as a catalyst mg, polyisocyanate (Sumitomo Bayer Urethane
Co., Ltd., 10 g of Sumidur N3500 (solid content: 100%)) and a solvent of toluene / hexane = 5/5 were additionally mixed so that the viscosity became 3 mPa · s to prepare a coating solution. This protective layer coating solution was applied directly onto the phosphor layer by a dip coater, and then dried and cured at 120 ° C. Film thickness after drying is about 1μ
m. A radiation image conversion panel was prepared in the same manner as in Example 1, except that the protective layer was provided directly on the phosphor layer.

Comparative Example 1 A radiation image conversion panel was manufactured in the same manner as in Example 1 except that the amount of alumina used was changed to 26 g.

Comparative Example 2 A radiation image storage panel was manufactured in the same manner as in Example 1 except that the amount of alumina used was changed to 13 g.

Comparative Example 3 A radiation image storage panel was manufactured in the same manner as in Example 1, except that alumina was not used.

Comparative Example 4 A melamine formaldehyde resin powder (Eposter S6,
A radiation image conversion panel was manufactured in the same manner except that 52 g of Mohs hardness: about 4, average particle size: 0.6 μm) was used.

Comparative Example 5 A radiation image conversion panel was prepared in the same manner as in Example 1, except that 52 g of silica particles (Seahoster KE-P50, Mohs hardness: about 6, average particle size: 0.5 μm) were used instead of alumina. Was manufactured.

Comparative Example 6 A radiation image conversion panel with a protective layer was manufactured in the same manner as in Example 1, except that a 9 μm-thick PET having no resin coating layer was used as the protective layer.

Table 1 summarizes the names of powders used and the amounts used.

[0063]

[Table 1] (Evaluation experiment) Coefficient of friction The coefficient of friction of each protective film surface of the radiation image storage panels obtained in the examples and comparative examples was measured by the following method. First, the radiation image conversion panel was cut into a square of 2 cm × 2 cm to prepare a measurement sample. Next, the measurement sample was placed on a separately prepared polyethylene terephthalate sheet with the protective layer side down, and a load was applied on the sample so as to be 100 g including the weight of the sample. Next, the sample to which this load is applied is pulled along the sheet at a pulling speed of 4 cm / min, and the temperature is 25 ° C. using Tensilon (UTM-11-20: manufactured by Toyo Baldwin Co., Ltd.). Tensile force F (g) of a sample in a motion state at a speed of 4 cm / min under conditions of 60% humidity
Was measured. From this tensile force F and the above load (100 g), the coefficient of friction of the protective layer surface of the radiation image conversion panel sample was calculated by the value of tensile force / load.

2. Antifouling property / Scratch resistance The antifouling property of each protective film surface of the radiation image conversion panels obtained in Examples and Comparative Examples was measured by the following method.
First, the radiation image conversion panel was cut into a 25.2 cm × 30.3 cm rectangle to prepare a measurement sample. A line was drawn on the surface of the prepared sample with Black Magic Ink (registered trademark), and after drying, the surface was wiped dry with a tissue paper to check the remaining amount of the magic ink. Next, the protective film of the measurement sample was placed on the upper surface, and a nonwoven fabric of 2 × 3 cm square was slid back and forth 100,000 times under a load of 50 g thereon. After the sliding, the remaining amount of the black magic ink was similarly examined. The antifouling property was evaluated in the following four stages. A: Wipe off and no residue B: Slightly (about 20%) remaining C: About half remaining D: Half or more remaining The surface of the protective layer of the sample was observed by SEM to evaluate the scratch resistance. The evaluation was performed based on the following four criteria.

A: Almost no damage or abrasion B: Some damage or abrasion occurred, but not visible visually C: Many occurrences of damage or abrasion, slightly visible visually D: Damage or abrasion (Image quality evaluation) The image quality of the radiation image conversion panel was evaluated as follows. After irradiating the radiation image conversion panel with X-rays at a tube voltage of 80 KVp, the panel is scanned with He-Ne laser light (632.8 nm) to excite the phosphor and receive the stimulated emission emitted from the phosphor layer. This was converted into an electric signal, and this was reproduced as an image by an image reproducing device to obtain an image on a display device. The amount of stimulated emission was measured from the obtained phosphor layer, and noise (RM) at a dose of 10 mR was measured. The measuring device used was FCR9000 manufactured by Fuji Photo Film Co., Ltd. The driving evaluation is FCR9000
The vehicle was run 10,000 times at a temperature and a humidity of 15 ° C. and 10% RH using a traveling machine imitating the mechanism of the above. After running, the image was reproduced to confirm the presence / absence of an image abnormality due to scratches and dirt on the protective layer.

A: No abnormality B: Slight abnormality C: Abnormal The results are shown in Table 2. The stimulated emission was expressed as a relative value with the stimulated emission of the panel of Comparative Example 3 being 100.

[0067]

[Table 2] From the above experimental results, in the radiation image conversion panels of Examples 1 to 10, the protective film has a resin and Mohs hardness of 9 or more and an average particle size of 9 or more.
0.1 to 1 μm particles, and 50 to 200% by weight of the resin, so that even after 100,000 reciprocal sliding, the antifouling property is as good as the initial use. In addition to having high scratch resistance, the image quality was equal to or higher than the conventional one, the coefficient of friction was low, and the running durability was excellent.

On the other hand, in the case of Comparative Examples 1 and 2 in which the content of the particles was 50% by weight or less, the antifouling property, scratch resistance and running durability were not sufficient. Further, in the case of Comparative Example 3 containing no particles, the antifouling property, scratch resistance and running durability were further deteriorated. On the other hand, also in the case of Comparative Examples 4 and 5 having Mohs hardness of less than 9, the antifouling property, scratch resistance and running durability were poor. Comparative Example 6 shows the case of a protective film made of only PET film containing neither resin nor particles.

As described above, in the radiation image storage panel of the present invention, the protective film is made of a resin and Mohs hardness of 9 or more and has an average particle size of 0.1.
Particles having a particle size of 1 μm to 1 μm.
Since the content was from 200% by weight to 200% by weight, the antifouling property, scratch resistance and running durability were excellent, and the image quality was also good.

Claims (8)

[Claims] 1. A radiation image conversion panel having a phosphor layer comprising a stimulable phosphor and a protective film, wherein said protective film is made of a resin and has a Mohs hardness of 9 or more and an average particle size of 0.1 μm to 1 μm.
A radiation image conversion panel comprising: 50% to 200% by weight of the resin based on the weight of the resin. 2. The method according to claim 1, wherein said particles are 40% by weight based on the resin
2. The radiation image conversion panel according to claim 1, wherein the radiation image conversion panel contains from 0.1 to 120% by weight. 3. The radiation image conversion panel according to claim 1, wherein the particles are alumina. 4. The method according to claim 1, wherein the alumina is a single crystal and the ratio (D ₉₀ / D ₁₀ ) of the particle diameter D ₁₀ of 10% to the particle diameter D ₉₀ of 90% is 3 or less in a weight cumulative curve of the particle size distribution. The radiation image conversion panel according to claim 3, wherein the panel is monodisperse particles. 5. The radiation image conversion panel according to claim 1, wherein the resin is a fluorine-based copolymer resin and / or a silicone-based copolymer resin. 6. The radiation image conversion panel according to claim 1, wherein the protective film further contains a reactive silicone. 7. The radiation image conversion panel according to claim 1, wherein a transparent film is provided between the protective film and the phosphor layer. 8. The method according to claim 1, wherein the protective film is provided directly on the phosphor layer.
Item 6. A radiation image conversion panel according to Item 1.