JP2002098799A - Radiation luminescent panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation luminescent panel having good initial screen quality and causing less degradation of screen quality. SOLUTION: A phosphor layer 1 constructed of phosphor accumulated by an air phase deposition method is arranged on a support 3, and a protective layer is arranged on the phosphor layer 1 by vapor deposition of an inorganic material having a gas barrier ability without any light absorption in a wavelength ranging from 300 nm to 1000 nm.

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 converting transmitted radiation into visible light and / or ultraviolet radiation by the phosphor. The present invention relates to a radiation emitting panel such as an intensifying panel for X-ray photography.

[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.

The radiation image conversion panel used in the radiation image conversion method has, as a basic structure, an inorganic or organic support and a stimulable phosphor layer provided on the surface thereof. Since the stimulable phosphor of the phosphor layer has a property of exhibiting stimulable emission when irradiated with excitation light after absorbing radiation such as X-rays, the stimulable phosphor is transmitted through the subject or emitted from the subject. Radiation is absorbed by the stimulable phosphor layer of the radiation image conversion panel in proportion to the radiation dose, and a radiation image of a subject or a subject is formed on the panel as a radiation energy accumulation image. This accumulated image can be emitted as stimulated emission light by irradiating the excitation light, and the accumulated image of radiation energy is imaged by photoelectrically reading the stimulated emission light and converting it into an electric signal. It is possible to do.

[0005] A protective film is usually provided on the surface of the stimulable phosphor layer (the surface not facing the support), and the phosphor layer is chemically modified by moisture absorption or the like. Protects from pollution. The protective film is formed by applying a solution prepared by dissolving a transparent organic polymer substance in an appropriate solvent onto the phosphor layer, or an organic polymer film such as polyethylene terephthalate or a transparent polymer film. Known are those in which a protective film forming sheet such as a glass plate is separately formed and provided on the surface of the phosphor layer using an appropriate adhesive, or those in which an inorganic compound is formed on the phosphor layer by vapor deposition or the like. Have been. These are, in addition to Patent 2715189, JP-A-62-15498, JP-A-62-209400, JP-A-62-245200.
No., JP-A-8-043598, JP-A-8-201598, JP-B-4-76
No. 440 and Tokuhei 7-13680.

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, as described above, a radiation image conversion panel having a protective film formed by coating, such as being repeatedly used or stored for a long period of time, the sensitivity is reduced due to moisture absorption of the phosphor layer, The image quality may deteriorate. In particular, the phosphor layer provided by the vapor deposition method easily absorbs moisture because the phosphor is not covered with a binder or the like.

[0007]

As a protective film capable of preventing the sensitivity of the radiation image storage panel from lowering due to moisture absorption, glass is most preferable from the viewpoint of moisture permeability, but in the case of glass, the strength during the panel manufacturing process is reduced. Thickness from the surface
400 μm or more is required. For this reason, in the case of the glass protective film, the image quality may be deteriorated (blurred) due to the diffusion of light, and the initial image quality is not always satisfactory.

On the other hand, a transparent resin film has a thickness of 100 μm.
Even if it is thinner than the following, there is no problem in strength during the manufacturing process,
Although a thin layer is preferable in terms of initial image quality, it is inferior in moisture resistance, and when stored under high-temperature and high-humidity conditions, image quality is easily deteriorated due to moisture absorption of the phosphor layer.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radiation-emitting panel having a protective film having good initial image quality and little image quality deterioration.

In Japanese Patent Publication No. 4-76440, a method of forming an inorganic material layer such as SiO ₂ , SiC, or SiN by a vacuum evaporation method, a sputtering method, or the like is described as a general description of a protective layer. Among the inorganic substances listed here, SiC is dark green and has light absorption in a specific wavelength range, and SiN has low light transmittance, and has no light absorption at wavelengths from 300 nm to 1000 nm as in the present invention and It is not recognized as an inorganic substance having gas barrier properties, and there is no description about using this as an evaporation layer.

[0011] In addition, Japanese Patent No. 1999941 also describes aluminum oxide, silicon monoxide, and silicon dioxide as general descriptions, and these powdery stimulable phosphors are dispersed in a binder and applied by coating. It was used as an antireflection film of the provided phosphor layer, and was not recognized as a protective film having a gas barrier property of the phosphor layer provided by a vapor deposition method.

[0012]

According to the present invention, there is provided a radiation-emitting panel having a phosphor layer in which a phosphor is deposited on a support by a vapor deposition method and a protective layer in this order. The protective layer is a vapor-deposited layer containing an inorganic substance having no gas absorption at a wavelength of 300 nm to 1000 nm and having a gas barrier property.

A radiation-emitting panel is a radiation image conversion panel containing a stimulable phosphor or an X-ray for converting transmitted radiation into visible light and / or ultraviolet radiation using a non-stimulable phosphor. This is a wide concept including photographic intensifying panels.

No light absorption at a wavelength of 300 nm to 1000 nm means that the light transmittance is 90% at a wavelength of 300 nm to 1000 nm.
It means above.

The gas barrier properties and is, 1 atm, at 20 ° C. moisture permeability 6g / m ² / 24h or less, means that oxygen permeability 5 cc / m is ² / 24h or less, preferably moisture permeability 2 g / m ² / twenty four
h and an oxygen permeability of ² cc / m 2/24 h or less.

Preferably, the inorganic substance is aluminum oxide and / or silicon oxide. Although aluminum oxide and silicon oxide may be used alone, it is more preferable to use both aluminum oxide and silicon oxide together to form a protective layer.

It is preferable that a resin layer is further provided on the protective layer. The thickness of the resin layer is preferably from 0.5 μm to 20 μm. More preferably, the resin layer contains silicone.

The thickness of the protective layer is preferably from 0.01 μm to 0.5 μm, more preferably from 0.02 μm to 0.5 μm.

Preferably, the phosphor has a columnar shape. The columnar shape means that the short axis surface of the phosphor is in contact with the protective layer surface and the phosphor is standing in a columnar shape on the protective layer surface. The phosphor may be a stimulable phosphor.

[0020]

According to the present invention, the protective layer of the radiation-emitting panel is a vapor-deposited layer containing an inorganic substance having no gas absorption at a wavelength of 300 nm to 1000 nm and having a gas barrier property. The number of radiation emitting panels can be reduced.

That is, since the protective layer provided on the radiation-emitting panel of the present invention is a vapor-deposited layer of an inorganic substance having gas barrier properties, it can be formed as a thin layer.
Because of the thin layer, the image quality is not blurred due to the scattering of light, and a radiation-emitting panel with good initial image quality can be obtained.

Further, since it contains an inorganic substance that does not absorb light at a wavelength of 300 nm to 1000 nm and has a gas barrier property, it is possible to sufficiently protect the phosphor layer provided by the vapor deposition method from moisture absorption, and it is possible to repeat the process. It is possible to suppress the deterioration of the image quality when used.

When a resin layer is provided on the protective layer, the antifouling property of the radiation-emitting panel can be improved. When silicone is contained in this resin layer, the antifouling property can be further improved.

In order to read an X-ray image, a laser beam is irradiated from the surface of the protective layer. When the phosphor has a columnar shape, light enters from the end of the columnar phosphor and the light enters the phosphor layer. Is difficult to spread, so that a clearer X-ray image can be taken out.

It is to be noted that the present invention provides a panel for converting transmitted radiation into visible light and / or ultraviolet radiation using a non-stimulable phosphor, for example, improving the image quality of a phosphor layer such as an intensifying panel for X-ray photography. However, it is extremely useful in a radiation image conversion panel using a stimulable phosphor.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a radiation-emitting panel showing a first embodiment of the present invention, and FIG. 2 is a sectional view of a radiation-emitting panel showing a second embodiment of the present invention.

As shown in FIG. 1, the radiation-emitting panel of the present invention has a phosphor layer 1 in which a phosphor is deposited on a support 3 by a vapor deposition method, and a protective layer is further provided on the phosphor layer 1. It is formed by laminating layers 2.

In the radiation-emitting panel of the present invention, a resin layer 4 may be further provided on the protective layer 2 as shown in FIG.

FIG. 3 is a cross-sectional view schematically showing a phosphor layer composed of a columnar phosphor and a support. In this manner, the phosphor layer is such that the short-axis surface of the phosphor 11 is the support. 3 Touch on top,
It is preferable that the phosphor 11 has a columnar shape and forms a phosphor layer. When the phosphor is a phosphor layer of spherical particles,
The X-ray image may be blurred due to the diffusion of the laser light in the phosphor layer, but in the case of a columnar phosphor, light enters from the end of the columnar phosphor and diffuses in the phosphor layer. , It is possible to extract a clearer X-ray image.

The radiation emitting panel of the present invention will be described in more detail.

First, 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. Examples of the stimulable phosphor used in the radiation image conversion panel of the present invention include a general formula (M _1-f · M _f ^I ) X · bM ^III X3 ″ described in JP-B-7-84588. :. stimulable phosphor represented by cA (I) are preferred as the M ^I in the formula (I) in terms of stimulated emission luminance, Rb, Cs and / or C
Na and K containing s are preferable, and at least one alkali metal selected from Rb and Cs is particularly preferable. M
^III is preferably at least one trivalent metal selected from Y, La, Lu, Al, Ga and In. As X ″,
At least one halogen selected from F, Cl and Br is preferred. The b value representing the content of M ^III X3 ″ is 0 ≦ b ≦ 10
^It is preferably selected from the range of ^-2 .

In the general formula (I), the activator A is
At least one metal selected from the group consisting of Eu, Tb, Ce, Tm, Dy, Ho, Gd, Sm, Tl and Na is preferable, and especially Eu, Ce, S
At least one metal selected from m, Tl and Na is preferred. The C value representing the amount of the activator is 10 ⁻⁶ <C <0.1.
It is preferable from the viewpoint of photostimulated light emission luminance.

Further, the following stimulable phosphors can also be used.

As described in US Pat. No. 3,859,527,
SrS: Ce, Sm, SrS: Eu, Sm, ThO_Two: Er, and La_TwoO_TwoS:
Eu, Sm, ZnS: Cu, P described in JP-A-55-12142
b, BaO xAl_TwoO_Three: Eu (where 0.8 ≦ x ≦ 10) and M
^IIOxSiO_Two: A (but M^IIIs Mg, Ca, Sr, Zn, Cd, or
Or A is Ce, Tb, Eu, Tm, Pb, Tl, Bi or
Mn, and x satisfies 0.5 ≦ x ≦ 2.5).
(Ba_1-Xy, Mg_X, Ca_y) FX: aEu
²⁺(Where X is at least one of Cl and Br
And x and y are 0 <x + y ≦ 0.6 and xy ≠ 0.
And a is 10^-6≦ a ≦ 5 × 10^-2And JP-A-55-1214
LnOX: xA described in No. 4 (where Ln is La, Y, G
at least one of d and Lu; X is Cl and Br
At least one of them, A is at least one of Ce and Tb
And x is 0 <x <0.1).
No. 55-12145 (Ba_1-X, M²⁺ _X) FX: yA (ta
But M²⁺Is the lesser of Mg, Ca, Sr, Zn, and Cd
X is at least one of Cl, Br and I
Species, A is Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb and Er
X is 0 ≦ x ≦ 0.6, y
Is 0 ≦ y ≦ 0.2) described in JP-A-55-160078.
M^IIFX xA: yLn (however, M^IIIs Ba, Ca, Sr, Mg,
At least one of Zn and Cd, A is BeO, MgO, Ca
O, SrO, BaO, ZnO, Al_TwoO_Three, Y_TwoO_Three, La_TwoO_Three, In_TwoO_Three, Si
O_Two, TiO_Two, ZrO_Two, GeO_Two, SnO_Two, Nb_TwoO_Five, Ta_TwoO_FiveAnd ThO
_TwoLn is Eu, Tb, Ce, Tm, Dy,
At least one of Pr, Ho, Nd, Yb, Er, Sm and Gd
The species X is at least one of Cl, Br and I
Where x and y are each 5 × 10^-Five≤x≤0.5, and 0 <
y ≦ 0.2), a phosphor represented by a composition formula:
-116777 (Ba_1-X, M^II _X) F_Two・ ABaX_Two: yEu,
zA (however, M^IIIs beryllium, magnesium, calcium
Of chromium, strontium, zinc and cadmium
X is at least one of chlorine, bromine and iodine
At least one, A is zirconium and scandium
A, x, y, and z
Are 0.5 ≦ a ≦ 1.25, 0 ≦ x ≦ 1, 10^-6≦ y ≦ 2
× 10^-1, And 0 <z ≦ 10^-2Is represented by the composition formula
Phosphor, described in JP-A-57-23673 (B
a_1-X, M^II _X) F_Two・ ABaX_Two: yEu, zB (where M ^IIIs Belliriu
, Magnesium, calcium, strontium, zinc
And at least one of cadmium and X is chlorine,
At least one of bromine and iodine, a,
x, y, and z are respectively 0.5 ≦ a ≦ 1.25, 0 ≦ x ≦
1, 10^-6≦ y ≦ 2 × 10^-1, And 0 <z ≦ 10^-2Is)
Phosphor represented by the composition formula of JP-A-57-23675
(Ba_1-X, M^II _X) F_Two・ ABaX_Two: yEu, zA (where M
^IIIs beryllium, magnesium, calcium, stron
At least one of titanium, zinc and cadmium
Species, X is at least one of chlorine, bromine and iodine
Species A is at least one of arsenic and silicon
A, x, y, and z are each 0.5 ≦ a ≦ 1.25,
0 ≦ x ≦ 1,10^-6≦ y ≦ 2 × 10^-1, And 0 <z ≦ 5 × 10
^-1A phosphor represented by the composition formula:
M listed in Issue 81^IIIOX: xCe (where M^IIIIs P
r, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and Bi
At least one trivalent metal selected from the group consisting of
X is either Cl or Br or its
X is 0 <x <0.1).
Phosphor, Ba described in JP-A-58-206678
_1-XM_{X / 2}L_{X / 2}FX: yEu²⁺(However, M is Li, Na, K, Rb
At least one kind of alka selected from the group consisting of
L represents Sc, Y, La, Ce, Pr, Nd, Pm, S
m, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, In and
At least one trivalent metal selected from the group consisting of
X is selected from the group consisting of Cl, Br and I
Represents at least one halogen; and x is 10
^-2≦ x ≦ 0.5, y is 0 <y ≦ 0.1)
Phosphor, 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 tetrafur
A calcined product of an oroboric acid compound; and x is 10^-6
≦ x ≦ 0.1, y is 0 <y ≦ 0.1)
Phosphor, BaFX described in JP-A-59-47289
・ XA: yEu²⁺(Where X is a group consisting of Cl, Br and I
At least one halogen selected from
Xafluorosilicic acid, hexafluorotitanic acid and
Xafluorozirconate monovalent or divalent metal
Less selected from the group of hexafluoro compounds consisting of salts
Are calcined products of a compound; and x is 10^-6≤
x ≦ 0.1, y is 0 <y ≦ 0.1)
Phosphor, BaFXx described in JP-A-59-56479
NaX ′: aEu²⁺(However, X and X 'are Cl, B
r and at least one of I, x and
a is 0 <x ≦ 2 and 0 <a ≦ 0.2, respectively.
Phosphor represented by the composition formula of JP-A-59-56480
M^IIFX ・ xNaX ′: yEu²⁺: zA (where M^IIIs B
at least one selected from the group consisting of a, Sr and Ca
X and X 'are each C
at least one selected from the group consisting of l, Br and I
A is V, Cr, Mn, Fe, Co and Ni
At least one transition metal selected; and
x is 0 <x ≦ 2, y is 0 <y ≦ 0.2, and z is 0 <z
≦ 10^-2A phosphor represented by the composition formula:
M described in -75200^IIFX ・ aM^IX ′ ・ bM ′^IIX ″_Two・
cm^IIIX_Three・ XA: yEu²⁺(However, M^IIIs from Ba, Sr and Ca
At least one alkaline earth metal selected from the group consisting of
And M^IIs from the group consisting of Li, Na, K, Rb and Cs
At least one alkali metal selected; M ′^IIIs
At least one member selected from the group consisting of Be and Mg
Is a valent metal; M^IIIIs a group consisting of Al, Ga, In and Tl
Is at least one trivalent metal selected; A is a metal
X is selected from the group consisting of Cl, Br and I
At least one halogen; X ', X "and
 X is a small number selected from the group consisting of F, Cl, Br and I
At least a halogen; and 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
A phosphor represented by the composition formula of JP-A-60-84381
M listed in the issue^IIX_Two・ AM^IIX ′_Two: xEu²⁺(However
Then M^IIIs a small number selected from the group consisting of Ba, Sr and Ca
At least a kind of alkaline earth metal; X and X 'are C
at least one selected from the group consisting of l, Br and I
And X ≠ X ′; and a is
0.1 ≦ a ≦ 10.0, x is 0 <x ≦ 0.2)
Stimulable phosphor described in JP-A-60-101173
M^IIFX ・ aM^IX ′: xEu²⁺(However, M^{II Is}Ba 、 Sr
At least one type of al selected from the group consisting of
Potassium earth metal; M^IIs from the group consisting of Rb and Cs
At least one alkali metal selected; X is Cl,
At least one member selected from the group consisting of Br and I
X 'is a group consisting of F, Cl, Br and I
At least one selected halogen; and a
And x are 0 ≦ a ≦ 4.0 and 0 <x ≦ 0.2, respectively.
Stimulable phosphor represented by the following formula:
M described in No. 89^IX: xBi (where M^IAre Rb and
At least one alkali selected from the group consisting of
X is selected from the group consisting of Cl, Br and I
X is at least one halogen; and x is 0 <x ≦
Photostimulability represented by a composition formula of 0.2)
Phosphor, LnOX: xCe described in JP-A-2-229882 (however, Ln
Is at least one of La, Y, Gd and Lu, and X is C
at least one of l, Br and I, x is 0 <x ≦ 0.2
And the ratio between Ln and X is 0.500 <X / Ln ≦ 0.998 in atomic ratio.
And the maximum wavelength λ of the stimulable excitation spectrum is 550n
Cerium-activated rare earth oxy represented by m <λ <700 nm)
Halide phosphor, and the like.

Further, the JP 60-84381 No. M ^II X ₂ · aM ^II X described in the _'2: xEu ²⁺ stimulable phosphor, is added, such as the following 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 at least one alkali metal, and X" is F, Cl, B
at least one member selected from the group consisting of r and I
And b is 0 <b ≦ 10.0);
BKX ″ and cMgX described in Sho 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
Described in -228593 (where A is SiO _TwoAnd
And P_TwoO_FiveAt least one oxide selected from the group consisting of
And b is 10^-Four≦ b ≦ 2 × 10^-1);
BSiO described in No. 61-120883 (where b is 0 <b
≦ 3 × 10^-2Is described in JP-A-61-120885.
BSnX ″_Two(However, X ″ is composed of F, Cl, Br and I.
At least one halogen selected from the group consisting of
And b is 0 <b ≦ 10^-3Described in JP-A-61-235486.
BCsX ″ and cSnX listed_Two(However, X ″ and X are
A small number selected from the group consisting of F, Cl, Br and I, respectively.
At least a kind of halogen, and b and c are
0 <b ≦ 10.0 and 10 respectively^-6≦ c ≦ 2 × 10^-2In
BCs described in JP-A-61-235487
X ″ ・ yLn³⁺(However, X ″ consists 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).

However, the stimulable phosphor used in the present invention is not limited to the above-described phosphors, and any phosphor that emits stimulable light when irradiated with radiation and then with excitation light. There is no particular limitation.

Further, the radiation-emitting panel of the present invention is
Transmissive radiation with visible light and
And / or panels for converting to ultraviolet radiation, for example
The phosphor used for radiographic intensifying screens
As a tungstate-based phosphor (CaWO_Four, MgW
O_Four, CaWO_Four: Pb), terbium-activated rare earth oxysulfide
Phosphor (Y_TwoO_TwoS: Tb, Gd_TwoO_TwoS: Tb, La_TwoO_TwoS: Tb, (Y, Gd)_TwoO
_TwoS: Tb, (Y, Gd) O_TwoS: Tb, Tm etc.), Terbium activated rare earth
Phosphate phosphors (YPO_Four: Tb, GdPO_Four: Tb, LaPO_Four: Tb
Terbium-activated rare earth oxyhalide-based fireflies
Optical body (LaOBr: Tb, LaOBr: Tb, Tm, LaOCl: Tb, LaOCl: Tb, T
m, LaOCl: Tb, Tm, LaOBr: Tb, GdOBr: Tb, GdOCl: Tb
Thulium-activated rare earth oxyhalide phosphor
(LaOBr: Tm, LaOCl: Tm, etc.), barium sulfate based phosphor
(BaSO_Four: Pb 、 BaSO_Four:EU²⁺, (Ba, Sr) SO_Four:EU²⁺Such),
Bivalent europium activated alkaline earth metal phosphate-based fireflies
Light body (Ba_Three(PO_Four)_Two:EU²⁺, Ba_Three(PO_Four)_Two:EU²⁺Etc.)
Europium activated alkaline earth metal fluoride halides
Phosphor (BaFCl: EU²⁺, BaFBr: Eu²⁺, BaFCl: EU²⁺, Tb, Ba
FBr: Eu²⁺, Tb, BaF_Two・ BaCl_Two・ KCl: Eu²⁺, (Ba ・ Mg) F_Two・ BaCl
_Two・ KCl: Eu ²⁺Etc.), iodide-based phosphors (CsI: Na, CsI: T
l, NaI, KI: Tl), sulfide-based phosphors (ZnS: Ag, (Zn, C
d) S: Ag, (Zn, Cd) S: Cu, (Zn, Cd) S: Cu, Al, etc.), phosphoric acid
Hafnium-based phosphor (HfP_TwoO₇: Cu etc.), tantalate
Based phosphor (YTaO_Four, YTaO_Four: Tm, YTaO_Four: Nb 、 (Y, Sr) TaO
_4-x: Nb, LuTaO_Four, LuTaO_Four: Nb 、 (Lu, Sr) TaO_4-x: Nb, Gd
TaO_Four: Tm, Gd_TwoO_Three・ Ta_TwoO_Five・ B_TwoO_Three: Tb)
Can be However, the phosphor used in the present invention is
It is not limited to these, but can be
Use any phosphor that emits light in the visible or near ultraviolet region.
Can be

Hereinafter, a radiation image conversion panel using a stimulable phosphor among radiation emission panels will be described. The stimulable phosphor layer is provided with the stimulable phosphor on a support by a vapor deposition method.

The support is preferably made of an inorganic film from the viewpoint of moisture resistance. However, if the thickness is large, a plastic plate can also be used since the moisture permeability can be substantially ignored. Specifically, metal plates such as aluminum plates and stainless steel plates, glass plates, ceramic plates, PVC plates, melamine phenol resin plates, PET plates, FRP
Plate, GFRP plate and the like can be preferably used. The thickness of the support is preferably about 100 μm to 5 mm. These supports may be opaque in the case of single-sided excitation / light collection, or may be used by providing a light-shielding layer or a reflective layer on a transparent support. On the other hand, when exciting or condensing light from both sides of the panel, it is preferable to use a transparent material.

The phosphor layer can be formed on a support by a known vapor deposition method such as an evaporation method or a sputtering method.
In the vapor deposition method, first, a support is placed in a vapor deposition apparatus, and then the inside of the apparatus is evacuated to a degree of vacuum of about 10 ⁻⁴ Pa. Next, at least one of the stimulable phosphors is heated and evaporated by a method such as a resistance heating method or an electron beam method to deposit the stimulable phosphor on the surface of the support to a desired thickness. Thereby, a stimulable phosphor layer containing no binder can be formed. It is also possible to form the stimulable phosphor layer by performing the vapor deposition step a plurality of times. In the vapor deposition step, a plurality of resistance heaters or electron beams are used for co-evaporation to synthesize a desired stimulable phosphor on a support and simultaneously form a stimulable phosphor layer. After the deposition, a radiation image conversion panel is manufactured by providing a protective layer on the opposite side of the stimulable phosphor layer from the support as described later. Further, at the time of vapor deposition, the object to be deposited (protective layer) may be cooled or heated as necessary. After the deposition, the stimulable phosphor layer may be subjected to a heat treatment.

In the sputtering method, as in the case of the vapor deposition method, a support is placed in a sputtering apparatus, and then the inside of the apparatus is once evacuated to a degree of vacuum of about 10 ^-4 Pa, and then Ar, Ne or the like is used as a sputtering gas. Is introduced into the sputtering apparatus to a gas pressure of about 10 ^-1 Pa.

Next, using a stimulable phosphor as a target,
By sputtering, the stimulable phosphor is deposited to a desired thickness on the surface of the protective layer. In the sputtering step, similarly to the vapor deposition method, it is also possible to form the stimulable phosphor layer in a plurality of times, or, using a plurality of targets made of different stimulable phosphors, Simultaneously or sequentially, it is also possible to form a stimulable phosphor layer by sputtering a target. In the sputtering method, reactive sputtering may be performed by introducing a gas such as O ₂ , H _2, or halogen as needed. After the end of the sputtering, a radiation image conversion panel is manufactured by providing a protective layer on the side opposite to the support side of the stimulable phosphor layer as in the vapor deposition method. In the sputtering method, as in the case of the vapor deposition method, the object to be vapor-deposited (primary protective layer) may be cooled or heated as needed during the sputtering. After the end of the sputtering, the stimulable phosphor layer may be subjected to a heat treatment.

The protective layer is a transparent vapor-deposited layer on which an inorganic substance having no gas absorption at a wavelength of 300 nm to 1000 nm and having a gas barrier property is vapor-deposited. Inorganic substances that do not absorb light at wavelengths from 300 nm to 1000 nm include, for example, silicon oxide, aluminum oxide,
There are zirconium oxide and tin oxide, among which aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO _x , x: 1-2)
Is particularly preferable because it has a high light transmittance and a high gas barrier property, that is, it can form a dense film with few cracks and micropores. Aluminum oxide and silicon oxide may be deposited alone, but if both are deposited together, the gas barrier properties can be further improved, so it is more preferable to deposit both aluminum oxide and silicon oxide.
The thickness of the protective layer is preferably from 0.01 μm to 0.5 μm, more preferably from 0.02 to 0.5 μm.

The protective layer may have a haze as long as it is within the range of 50% or less, and it is preferable to appropriately adjust according to the excitation / light collecting method, the image processing method, or the thickness and material of the protective layer.

The inorganic substance is deposited on the phosphor layer by a PVD method (P
hysical Vapor Deposition, or CVD
Method (Chemical Vapor Deposition) or P
A method such as E-CVD (Plasma enhanced CVD) can be used. The transparency and barrier properties of the protective layer are not significantly changed by any of the methods, and can be appropriately selected.

A resin layer may be further provided on the deposited protective layer by applying a coating liquid for a resin layer or laminating a resin film. Resin layer thickness is 0.5
μm to 20 μm, preferably 0.5 μm to 10 μm
More preferably, it is more preferably from 1 μm to 5 μm.

Similarly to the protective layer, the resin layer has a wavelength of 300 nm to 1 nm.
It is preferable that there is no light absorption at 000 nm and the moisture permeability is as low as possible. Specifically, it is preferably a fluororesin, polyethylene, polypropylene, PET, rubber hydrochloride, vinylidene chloride copolymer, or the like, and more preferably a fluorocopolymer.

The resin layer preferably contains silicone, and the silicone is more preferably a reactive silicone (silicone macromonomer).
As the reactive silicone, for example, those having a dimethylpolysiloxane skeleton can be used. It is preferable to apply a soluble fluororesin containing a reactive silicone or a curing agent because the radiation image conversion panel is provided with a higher antifouling property.

It is to be noted that moisture absorption from the side surface of the phosphor layer cannot be sufficiently prevented only by the vapor barrier protective layer having a gas barrier property, and thus is sealed with an epoxy resin, a UV curing resin, a metal (solder) or the like. Is preferred. Also,
In order to prevent performance degradation due to moisture absorption of the phosphor layer, it is preferable to perform the process from removal from the vapor deposition tank (vaporizer) to sealing of the end face in vacuum or dry air or an inert gas or a hydrophobic inert gas. .

Hereinafter, the present invention will be described more specifically with reference to examples.

EXAMPLES (Example 1) A 1 mm thick quartz glass plate (UFF0.40 manufactured by Nippon Sheet Glass Co., Ltd.) was placed in a vapor deposition device as a support. Next, the alkali halide stimulable phosphors (Cs.Br) and (Eu) were placed in two platinum boats, and the inside of the evaporator was evacuated to a degree of vacuum of 2 × 10 ⁻⁴ Pa. Thereafter, the stimulable phosphor in the platinum boat is irradiated with an electron beam having an accelerating voltage of 2.3 kV for 30 minutes from an electron gun, and the stimulable phosphor (Cs · Br: 0.02Eu) was deposited in columns. After the phosphor deposition, a platinum boat containing aluminum was set, and the aluminum was heated while introducing oxygen gas into the evaporator so that the pressure became 10 ^-1 Pa, thereby forming an aluminum oxide protective layer having a thickness of 0.05 μm. .

The irradiation of the electron beam was stopped, the inside of the evaporator was returned to the dried atmospheric pressure, and the quartz glass plate was taken out. A columnar stimulable phosphor having a thickness of 20 μm and a length of 900 μm was densely deposited on a quartz glass plate, and a protective layer of aluminum oxide was formed on the surface thereof.

Next, an epoxy resin was applied to the periphery of the phosphor in a dry nitrogen gas chamber, and the phosphor layer was sealed to obtain a radiation image conversion panel.

Example 2 A radiation image conversion panel was obtained in the same manner as in Example 1 except that the thickness of the aluminum oxide protective layer was changed to 0.1 μm.

Example 3 A 2 μm thick antifouling layer (containing antireflective white powder) was provided on the aluminum oxide protective layer of the panel formed in Example 2. The antifouling layer is composed of 40 g of a fluorine-based copolymer solution (Lumiflon LF504 (30% xylene solution) manufactured by Asahi Glass Co., Ltd.), 28.4 g of melamine-formaldehyde (Nippon Shokubai Co., Ltd., Eposter S6) as an organic filler, and a dispersant. 0.5mm of aluminum coupling agent (Ajinomoto Co., Prenact AL-M) and 200g of methyl ethyl ketone (MEK) as 3mm
After dispersing and mixing for 20 hours in a ball mill using zirconia balls of φ, Lumiflon LF504X (30% xylene solution)
360 g was added and dispersed for another 4 hours. After that, a silicone macromonomer (manufactured by Chisso Corporation: Cylaprene FM-D)
A26) 5.6 g, polyisocyanate (Sumitomo Bayer Urethane Co., Ltd., Sumidur N3300 (solid content 100
%)) 22.2 g, dibutyltin dilaurate (Kyodo Yakuhin Co., Ltd., KS1260) 1.4 mg and MEK 800 g were additionally mixed as a catalyst to prepare an antifouling layer coating solution, which was applied on the protective layer, dried,
Cured to give a radiation image conversion panel.

Example 4 Instead of aluminum oxide,
A radiation image conversion panel was obtained in the same manner as in Example 3 except that silicon oxide (SiO _x (0 <x ≦ 2)) having a thickness of 0.1 μm was used as a protective layer.

Comparative Example 1 A radiation image conversion panel was obtained in the same manner as in Example 1, except that the aluminum oxide protective layer was not provided.

Comparative Example 2 A radiation image storage panel was obtained in the same manner as in Example 3 except that the aluminum oxide protective layer was not provided.

(Evaluation Experiment) The radiation image conversion panels obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were subjected to the following evaluation experiments. Table 1 shows the results.

1. Emission intensity After irradiating the radiation image conversion panel with X-rays at a tube voltage of 80 kVp, the phosphor is excited by scanning with He-Ne laser light (632.8 nm), and the stimulus emitted from the phosphor layer is emitted. The emitted light was received and converted into an electric signal, and the amount of stimulated emission was measured. The luminescence amount was expressed as a relative value when Example 1 was set to 100%.

[0061] 2. Humidity Resistance The obtained panel was placed in a high-temperature, high-humidity room at 60 ° C. and 80% RH for one week, and the change in stimulable luminescence was examined.

：: reduction of less than 5% Δ: reduction of 5% or more and less than 10% X: reduction of 10% or more

3. Magic (registered trademark) antifouling property A line was drawn with black magic on the surface of the protective layer, dried and wiped with a Kimwipe, and the degree of erasure of the magic line was observed.

：: No remaining line Δ: About half remaining X: Full remaining

[0065]

[Table 1] In the radiation image storage panel of Comparative Example 1, the phosphor layer absorbed and dissolved when the moisture resistance was checked.

As is clear from the above experimental results, the radiation image conversion panel according to the present invention had a good initial image and excellent moisture resistance. In Examples 3 and 4 having the resin layer containing the reactive silicone, the antifouling property was excellent.

In the examples, only the radiation image conversion panel has been described, but the protective layer of the present invention can be similarly used for an intensifying panel for X-ray photography.

[Brief description of the drawings]

FIG. 1 is a sectional view of a radiation-emitting panel according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a radiation-emitting panel according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view schematically showing a phosphor layer composed of columnar phosphors and a support.

[Explanation of symbols]

 Reference Signs List 1 phosphor layer 2 protective layer 3 support 4 resin layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 11/61 CPF C09K 11/61 CPF G03B 42/00 G03B 42/00

Claims (9)

[Claims] 1. A radiation-emitting panel having a phosphor layer in which a phosphor is deposited on a support by a vapor deposition method and a protective layer in this order, wherein the protective layer has a wavelength of 300 nm to 1 nm.
A radiation-emitting panel comprising a vapor-deposited layer containing an inorganic substance having no gas absorption at 000 nm and having a gas barrier property. 2. The radiation-emitting panel according to claim 1, wherein the inorganic substance is aluminum oxide and / or silicon oxide. 3. The radiation-emitting panel according to claim 1, wherein a resin layer is provided on the protective film. 4. The radiation-emitting panel according to claim 3, wherein the thickness of the resin layer is 0.5 μm to 20 μm. 5. The radiation-emitting panel according to claim 3, wherein the resin layer contains silicone. 6. The protective layer has a thickness of 0.01 μm to 0.5 μm.
The radiation-emitting panel according to any one of claims 1 to 5, wherein Wherein said gas barrier moisture permeability 2g / m ^2/24
The radiation emitting panel according to any one of claims 1 to 6, wherein an oxygen permeability is ² cc / m2 / 24h or less. 8. The radiation-emitting panel according to claim 1, wherein the phosphor has a columnar shape. 9. The radiation-emitting panel according to claim 1, wherein the phosphor is a stimulable phosphor.