JPH09197097A - Radiation image conversion screen and composition for forming radiation image conversion screen protection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image conversion screen superior in durability due to having a protection film and superior in surface hardness, softness and smoothness of the film. SOLUTION: The radiation image conversion screen having at least a fluorescent layer and a protection layer on a support body is obtained by spreading and drying a liquid component formed by mixing a cured matter made by adding water to tetramethoxysilane, curing, hydrolyzing and condensing and a reactive nonorganic compound having two or more functional groups capable of condensing with the hydrolyzed and condensed material of tetramethoxysilane in the cured matter.

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 screen (hereinafter abbreviated as "image conversion screen"). More specifically, it relates to an image conversion screen having a protective layer and having excellent durability, surface hardness, flexibility and film slipperiness.

[0002]

2. Description of the Related Art Image conversion screens are, for example, intensifying screens, fluorescent screens, radiation image conversion panels, etc., and convert X-ray images of a subject into visible images, thereby taking X-ray photographs and substances for medical diagnosis. It is used to improve sensitivity in the field of industrial radiography for non-destructive inspection. The image conversion screen is basically provided with a phosphor layer composed of a phosphor and a support on one surface of a support such as paper or plastic, and a plastic thin film capable of further transmitting light thereon, if necessary. It is formed by forming a protective film. CaWO instantly emits light with high brightness when exposed to X-rays.
₄ , an intensifying screen using a phosphor such as Gd ₂ O ₂ S: Tb as a phosphor layer is used in close contact with an X-ray film. Also G
A phosphor plate using a phosphor such as d ₂ O ₂ S: Tb or (Zn, Cd) S: Ag as a phosphor layer is used in combination with an X-ray film. BaFBr: E which is a stimulable phosphor
A radiation image conversion panel using a phosphor such as u, LaOBr: Ce, Tb as a phosphor layer is disclosed in, for example, JP-A-55-1.
As described in Japanese Patent No. 5025, the radiation image conversion panel does not use an X-ray photographic film at the time of X-ray photography, but accumulates an X-ray image once it is exposed to X-rays, The X-ray image accumulated by irradiating the excitation light is emitted as stimulated emission. The radiation image conversion panel is used in a system for reading the photostimulable light to obtain image data, applying image processing as necessary, and drawing an image on a film or a display.

By the way, the image conversion screen has high photographic quality in addition to high sensitivity and durability against damage, abrasion and scratches due to mechanical stimuli such as impact, bending, contact and dust, and film and cleaner, It is required to have high durability against coloration due to chemical stimuli such as oil and permeation of chemical substances. That is, when the image conversion screen is scratched, worn, or colored due to contamination, an abnormal shadow may be generated on the photograph, or the photographic image quality may be deteriorated due to a decrease in sensitivity or sharpness. In order to minimize such performance deterioration of the image conversion screen, a transparent protective film is usually provided on the surface of the image conversion screen which is in direct contact with the film.

As a general method for forming a protective film, a method called a laminating method in which an organic polymer film such as polyethylene terephthalate, polyethylene, polyvinylidene chloride or polyamide is laminated on a phosphor layer and cellulose acetate are used. , Cellulose derivatives such as nitrocellulose, cellulose acetate butyrate, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polycarbonate, polyvinyl butyral, polymethyl methacrylate, polyvinyl formal, polyurethane, etc. There is a method called a solution coating method in which a protective film coating solution having an appropriate viscosity is prepared, and this is applied on the phosphor layer of the previously formed protective film-less image conversion screen and dried.

In order to improve the durability of the image conversion screen, it is effective to increase the thickness of the protective film. However, if the thickness of the protective film is increased, the sharpness is lowered and durability and photographic image quality are improved. At the same time, it was difficult to improve.

The characteristics required for the protective film in order to obtain an image conversion screen with high image quality and durability are that adhesive strength between the phosphor layer and the protective film is high, X-ray film, dust, transportation, etc. On the other hand, it has good scratch resistance and wear resistance, and is unlikely to cause scratches or pinholes. It also has excellent resistance to dirt and dust, oil and chemical substances such as X-ray films and cleaners, and solvent resistance, etc. However, it is difficult for contaminants to enter the inside of the phosphor layer and the phosphor layer is not colored.

In recent years, labor saving and automation of photographing have progressed, and X-ray photographic film is automatically fed to a photographing position and is forcibly taken out after photographing in a film conveying device such as a cassette-less X-ray television. With the increasing use of, the demand for scratch resistance and stain resistance of image conversion screens is increasing without degrading image quality. At the same time, there is a demand for good film slipperiness in order to make it easier to take out the film after photographing.

An image conversion screen in which a protective film is formed by laminating an organic polymer film such as a polyethylene terephthalate film on a phosphor layer has an X-ray image as compared with an image conversion screen in which the protective film is formed by solution coating.
It has excellent stain resistance and solvent resistance to chemical substances from line film, cleaners, etc., but the adhesive strength with the phosphor layer is poor, so the protective film is easily peeled off, and pinholes easily occur on the protective film. There is a problem that hole coloring is likely to occur.

On the other hand, among the protective film materials, the protective film formed by dissolving the protective film forming resin in a solvent and applying the solution forms a protective film having good adhesion with the phosphor layer, so that the phosphor is formed. It has the advantages that it has high adhesive strength with the layer, that the protective film is difficult to peel off, and that pinholes in the protective film are less likely to be caused by foreign matter and pinhole coloring is less likely to occur. However, when the protective film is formed by solution coating, there is a problem that scratch resistance and stain resistance are inferior to the case where the organic polymer film such as polyethylene terephthalate is laminated on the phosphor layer to form the protective film. .

In both the laminating method and the solution coating method, if the thickness of the protective film is reduced in order to increase the sharpness, the durability such as scratch resistance, stain resistance and pinhole resistance is further lowered, and it is practically used. There was a problem.

Therefore, as a measure for improving the durability and use characteristics of an image conversion panel using an intensifying screen or a stimulable phosphor, JP-A-4-310900, JP-A-4-309898 and JP-A-6-75097 are used. The publication discloses a coating solution for forming a protective film in which a polysiloxane skeleton-containing oligomer, a perfluoroalkyl group-containing oligomer, a perfluoroolefin resin powder, a silicone resin powder or the like is added to an organic solvent-soluble fluorine-based resin on the surface of a phosphor layer. It is described that a protective film formed by coating is used. However, it is not sufficient in terms of durability such as scratch resistance and stain resistance and usability such as film slippage.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has excellent durability such as scratch resistance and stain resistance, good film slipperiness, and easy usability of the film and good usability. It is intended to provide a radiation image conversion screen.

[0013]

Means for Solving the Problems In order to improve scratch resistance, abrasion resistance and stain resistance without deteriorating the image quality of the image conversion screen, the present inventors have diligently studied the material of the protective film, With a specific silicon compound as the material of the protective film,
The present invention has been found out that the above object can be achieved by using an inorganic-organic hybrid material having a specific composition, which is prepared by blending this with a specific organic compound capable of undergoing a condensation reaction.

That is, the present invention provides (1) on a support,
In an image conversion screen having at least a phosphor layer and a protective film, the protective film, an aged product obtained by adding water to tetramethoxysilane and aging to cause a hydrolysis condensation reaction,
It is obtained by coating and drying a liquid composition prepared by mixing a hydrolytic condensation product of tetramethoxysilane in the aged product with a reactive organic compound having two or more functional groups capable of undergoing a condensation reaction. An image conversion screen characterized by (2) an aged product obtained by adding water to tetramethoxysilane and aging it to cause a hydrolytic condensation reaction, and a condensation reaction with a hydrolytic condensation product of tetramethoxysilane in the aged product. A composition for forming an image conversion screen protective film, which comprises a reactive organic compound having two or more functional groups to be obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
As a general method for producing the image conversion screen of the present invention, a predetermined amount of a phosphor and a binder such as nitrification cotton are mixed, and an organic solvent is further added to the mixture to add a phosphor coating solution having an appropriate viscosity. Is prepared, and the coating solution is applied onto a support by a knife coater, a roll coater or the like, and dried to form a phosphor layer.

A light reflection layer, a light absorption layer or a metal foil layer is provided in advance between the phosphor layer and the support, and the phosphor coating solution is applied and dried on the phosphor layer. May be formed.

In order to prevent the generation of static electricity in the image conversion screen, an inorganic conductive material such as ZnO, SnO ₂ , In ₂ O ₃ or carbon is provided on the back side of the support or between the support and the phosphor layer. Alternatively, a conductive layer made of an organic conductive material may be provided.

As the above-mentioned binder, besides cellulose nitrate, cellulose acetate, ethyl cellulose, polyvinyl butyral,
Cotton-like polyester, polyvinyl acetate, vinylidene chloride-
Vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, polyalkyl- (meth) acrylate, polycarbonate, polyurethane, cellulose acetate butyrate, polyvinyl alcohol, gelatin, polysaccharides such as dextrin, gum arabic, etc. If known as
There is no particular limitation.

As the organic solvent used for preparing the phosphor layer coating liquid, for example, ethanol, methyl ethyl ketone, butyl acetate, ethyl acetate, ethyl ether, xylene, etc. are used. Further, a dispersant such as phthalic acid or stearic acid or a plasticizer such as triphenyl phosphate or diethyl phthalate may be added to the phosphor coating solution, if necessary.

The amount of the binder remaining in the phosphor layer is preferably 1 to 10 parts by weight in terms of solid content with respect to 100 parts by weight of the phosphor in terms of sharpness.
The solid content of the binder is more preferably 1 to 6 parts by weight with respect to 00 parts by weight.

Next, details of the protective film formed on the image conversion screen will be described. An aged product obtained by adding water to tetramethoxysilane and aging it to cause a hydrolytic condensation reaction, and a reactive organic compound having two or more functional groups capable of undergoing a condensation reaction with the hydrolytic condensation product of tetramethoxysilane in the aged product. A liquid composition obtained by blending with, on the phosphor layer surface as a protective film coating liquid, for example, a roll coater, a knife coater,
A doctor blade coater, a die coater or the like is used to uniformly apply the coating to a desired thickness, and the coating is dried to form a protective film.

The protective film coating liquid may be a coating liquid obtained by further adding a catalyst for accelerating and controlling the reaction to the above liquid composition. Further, a coating solution may be prepared by diluting the above liquid composition with an organic solvent at an appropriate ratio.

Before applying the protective film, a water repellent layer as described in JP-A-6-347598 is formed on the surface of the phosphor layer, and a protective film solution is applied and dried on the water repellent layer. The protective film layer can also be formed by doing so.

When water is added to tetramethoxysilane for aging and hydrolysis-condensation reaction is carried out to prepare an aged product, an organic solvent, particularly methanol, ethanol, propanol,
It is desirable to allow a monohydric alcohol such as butanol, or a dihydric or trihydric alcohol to be present.

The amount of the organic solvent used is 40 to 500 parts by weight, especially 50 parts by weight, based on 100 parts by weight of tetramethoxysilane.
˜95 parts by weight is preferable because the protective film is easily formed, the coatability and the physical properties of the resulting protective film are excellent. As the tetramethoxysilane, a monomer or an oligomer can be used. As the oligomer, for example, “MS-51” manufactured by Mitsubishi Chemical Corporation is used, the physical properties of the oligomer are stable and excellent, and the toxicity is low. It is also suitable in terms of safety.

The amount of water to be added is 0.05 mol times or more, particularly preferably 0.05 to 1 mol times, and more preferably 0.2 to 1 mol times the methoxy group of tetramethoxysilane. The amount is desirable because the resulting protective film has particularly excellent properties such as hardness and slipperiness.

Further, when the amount is 0.3 mol times or more, the self-crosslinking of tetramethoxysilane itself further proceeds, and "reactive ultrafine silica" described later is easily formed, so that a protective film having extremely high characteristics can be obtained. Can be formed.

Aging may be carried out in the presence of a catalyst. Examples of the catalyst include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid, organic acids such as acetic acid, formic acid, paratoluenesulfonic acid, benzoic acid, phthalic acid, maleic acid, propionic acid and oxalic acid, and potassium hydroxide. , Alkali hydroxides such as sodium hydroxide, calcium hydroxide, and ammonia, organic metals, metal alkoxides, such as organotin compounds such as dibutyltin laurylate, dibutyltin octoate, dibutyltin diacetate, aluminum tris (acetylacetonate), titanium tetrakis ( Acetylacetonate), titanium bis (isopropoxy) bis (acetylacetonate), zirconium tetrakis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate) and zirconium bis (isopropoxy) bi. (Acetylacetonate) metal chelate compounds such as boron butoxide, to use one or more of boron compounds such as boric acid.

The liquid may be aged as it is, but may be stirred. You may heat so that it may not gel.
It is sufficient to leave it at room temperature for about 1 hour to 2 days, preferably for several hours to 1 day.

It is also possible to finish the aging in a short time by heating to the boiling point of the solvent and aging under reflux.

As described above, in the aged product which is a liquid that has been aged, tetramethoxysilane hydrolyzed and condensed by aging forms fine particles having an inertial radius of 40 Å or less (hereinafter referred to as "reactive ultrafine silica"). It can be confirmed by means such as small-angle X-ray scattering. That is, due to the presence of the fine particles, the diffraction intensity distribution of the incident X-ray shows diffuse scattering called central scattering in the incident line direction, that is, small-angle X-ray scattering. The scattering intensity I is
It is given by the following Guinier equation.

[0032] ^{I = C exp (-H 2 R} g 2/3) (I: scattering intensity, H: scattering vector (= 2πsin2θ
/ Λ), R _g : radius of gyration of fine particles, C: Cons
t, λ: incident X-ray wavelength, 2θ: spread angle)

[0033] Taking the logarithm of equation both sides of the above ^{Guinier, logI = logC- (H 2} R g 2/3) , and the thus if there are small particles, the scattering intensity was measured, both with respect to the scattering vector Plot a logarithmic graph,
By obtaining the inclination, the radius of gyration of the fine particles can be obtained.

When measuring the radius of gyration, some measurement errors may occur depending on the concentration of the liquid to be measured or the solvent. For accuracy, it is desirable to calculate the radius of gyration by performing background correction of only the solvent and measurement with a diluted solution of the test solution. These reactive ultrafine silicas are
The radius of gyration is 20 Å or less, or 10 Å or less, which is extremely small and can exist stably.

An organic compound having a functional group capable of reacting with the hydrolysis-condensation product of tetramethoxysilane in the aged product (hereinafter referred to as "reactive organic compound") is added to the aged product thus obtained.

Examples of the reactive organic compound include polymethylmethacrylate, acrylic polyol, acrylic resin, methacrylic resin, polyester resin, polyester polyol, cellulose derivative such as cellulose acetate, nitrocellulose, cellulose acetate butyrate, nitrification cotton, polychlorination. Resins such as vinyl, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, polyvinyl formal, and polycarbonate, or vinyl group, methacryloxy group, epoxy group,
Examples thereof include silane coupling agents having a mercapto group, an amino group, an alkyl group and the like. These are 1
It is also possible to use a combination of more than one type. Examples of the silane coupling agent include the following.

[0037]

Embedded image γ-methacryloxypropyltrimethoxysilane

[0038]

Embedded image γ-glycidoxypropyltrimethoxysilane β- (3.4 epoxycyclohexyl) ethyltrimethoxysilane

[0039]

Embedded image Vinyltrimethoxysilane Vinyltriethoxysilane Vinyltris (βmethoxyethoxy) silane

[0040]

Embedded image γ-Aminopropyltriethoxysilane N-β (aminoethyl) γ-aminopropyltrimethoxysilane γ-ureidopropyltriethoxysilane

[0041]

Embedded image Methyltrimethoxysilane Dimethyldimethoxysilane

[0042]

Embedded image γ-mercaptopropyltrimethoxysilane

As the resin, polyester polyol, acrylic polyol, silicone modified acrylic,
It is particularly desirable to use one or more of nitrification cotton, vinyl chloride-vinyl acetate copolymer and polyvinyl alcohol. It is of course possible to use a resin and a silane coupling agent together.

In the image conversion screen of the present invention, the thickness of the protective film formed on the phosphor layer after drying is preferably thin from the viewpoint of sharpness, and thicker from the viewpoint of physical durability. However, in practice, the physical durability is sufficient, and in order to suppress the decrease in sharpness, the thickness may be 1 to 10 μm, and more preferably 1.5 to 7 μm.
It is particularly preferable that the thickness is 2 to 5 μm.

The content of silicon in terms of SiO ₂ in the protective film is 1
0 to 95% by weight, particularly preferably 15 to 80% by weight, more preferably 30 to 70% by weight is desirable because it has excellent physical properties such as slipperiness and hardness. The measurement of SiO ₂ in terms of silicon content, 1000 ° C. The quantity of the protective film, and baked 1 hour, a value determined content of the residue as SiO _2.

As the support used in the image conversion screen of the present invention, cellulose acetate, cellulose propionate, cellulose acetate butyrate, polyesters such as polyethylene terephthalate, polystyrene, polymethylmethacrylate, polyamide, polyimide, vinyl chloride-vinyl acetate. A film formed of a resin such as a copolymer or polycarbonate, baryta paper, resin-coated paper, ordinary paper, or aluminum alloy foil is used. In addition,
When the plastic film or paper as described above is used as the support of the image conversion screen of the present invention, a light absorbing substance such as carbon black or a light reflecting substance such as titanium dioxide or calcium carbonate is kneaded into the support. These may be mixed in advance.

Examples of the phosphor used in the image conversion screen of the present invention include Gd ₂ O ₂ S: Tb and Y ₂ O ₂ S: T.
b, La ₂ O ₂ S: Tb, (Gd, Y) ₂ O ₂ S: Tb, T
_{m, GdTaO 4: Tb, Gd} 2 O 3 · Ta 2 O 5 · B 2 O 3:
Tb, CaWO ₄ , BaSO ₄ : Pb, LaOBr: T
_{m, LaOBr: Tb, HfO 2} : Ti, HfP 2 O 7:
Cu, CdWO ₄ , YTaO ₄ , YTaO ₄ : Tm, YT
aO ₄ : Nb, ZnS: Ag, (Zn, Cd) S: A
_{g, BaFCl: Eu, Gd 3} Ga 5 O 12: Tb, Ba
FBr: Eu, BaF (Br, I): Eu, LaOB
Any phosphor such as r: Ce or Tb that emits light by X-ray excitation or a stimulable phosphor that produces stimulated emission upon X-ray irradiation can be used.

The thus obtained image conversion screen of the present invention is an image conversion screen in which a conventional organic polymer film is laminated to form a protective film, or a conventionally known protective film coating for an image conversion screen protective film. It is particularly excellent in durability and slipperiness as compared with an image conversion screen in which a protective film is formed by applying a liquid as a solution.

[0049]

Next, the present invention will be described by way of examples. still,
The present invention is not limited to the following examples.

(Example 1) [Preparation of image conversion screen without protective film] The average particle size was 5
A phosphor coating liquid 1 was prepared by thoroughly mixing 10 parts by weight of a Gm ₂ O ₂ S: Tb phosphor of 1 μm, 1 part by weight of a polyvinyl butyral resin (binder), and a mixed solvent of toluene, butyl alcohol, and acetone.

Next, this phosphor coating solution was applied onto a polyethylene terephthalate film (support) having a thickness of 250 μm and containing titanium dioxide kneaded, and the phosphor coating weight after drying was 50 mg / cm ² . Then, it was uniformly coated with a knife coater so as to be dried and a phosphor layer was formed. A water repellent (“Knit Seal” manufactured by Dainippon Paint Co., Ltd.) was dried on the phosphor layer with a bar coater, and the weight after drying was 0.03 mg /
A protective film-less image conversion screen N1 was produced by applying the coating liquid so that the coating film had a thickness of ² cm2 and drying.

[Preparation of Aged Product] 62.4 g of ethanol was added to 30.8 g of tetramethoxysilane oligomer (“MS-51” manufactured by Mitsubishi Chemical Corporation), which is a low condensation product of tetramethoxysilane, and then maleic acid was added. 0.3 g of acid and 6.5 g of dechlorinated water were added. This is left to stand at room temperature for 4 days in a sealed state and aged (hereinafter referred to as "aged 1", Si
O ₂ conversion concentration: 16% by weight) was obtained.

[Confirmation of fine particles] [Preparation of aged product]
Aged product (hereinafter referred to as “composition A”, Si
O _TwoConverted concentration 16% by weight, 8.1 vol%), and this
Liquid diluted with ethanol about 4 times (hereinafter referred to as "composition B")
That's SiO_TwoConverted concentration 4.3% by weight, 2 vol%)
Is analyzed by small-angle X-ray scattering under the following conditions.
Was.

Measuring apparatus: Kratonki compact camera manufactured by Anton Paar Co., Ltd. X-ray source: 50 kv, 200 mA, Cu-Kα ray monochromatic with Ni-filter Optical system condition: sample-light receiving slit distance = 20 cm
Inner vacuum path = 19cm Entrance slit = 80μm, Light receiving slit = 2
00μm, beam length = 16mm

Cell used: Quartz capillary (diameter about 1 m
m, wall thickness 10 μm) Other conditions: room temperature. step scan operation range 2θ =
0.086-8.1deg 90sec / point Data correction: Background correction was performed by using scattering when the quartz capillary was filled with water. X-ray absorption correction was also performed. Analysis software: Slit correction and Fourier transform are analysis software ITP-81 (O.Glatter; J.Appl.Cryst., 10.415).
-421 (1977). )It was used.

FIG. 1 and FIG. 2 show the measured data (background correction and absorption correction) of the scattering intensity of the composition A and the composition B with respect to the moving distance of the scattered X-rays in the light receiving slit. FIG. 3 and FIG. 4 show point beam data after slit correction of the composition A and the composition B.

From these FIG. 3 and FIG. 4, Guinie
r Formula I = C exp of _{^{(-H 2 R g 2/3}} ) (I: scattering intensity, H: scattering vector (= 2πsin2θ / λ), R
g: radius of gyration, C: Const, λ = Cu-Kα ray wavelength, 2
The maximum value of the radius of gyration is calculated according to θ: spread angle, and as shown in Figs. 5 and 6, for composition A, 7.0 Å (assuming a spherical shape, the real radius R = ((5/3 )
From R _g ) 1/2, the radius was 9.0 Å), and for composition B, it was 6.0 Å (radius 7.7 Å assuming a spherical shape). Moreover, the results of obtaining the distribution of the radius (assumed to be spherical) by performing the inverse Fourier transform on FIGS. 3 and 4 are shown in FIGS. 7 and 8.
Shown in The maximum radii were about 6Å and 7Å, respectively.

With respect to "MS-51" used as a raw material, a small angle X was obtained under the same conditions as [Confirmation of fine particles] above.
Analysis by line scattering was performed. Figure 9 shows the measured data of the scattering intensity. As is clear from this, no structure such as fine particles was observed.

[Preparation of coating solution for protective film] 40 g of aged product 1
60g of acrylic silicone resin was added and mixed to
After standing for a period of time, a protective film coating solution 1 was obtained. [Preparation of Image Conversion Screen with Protective Film] After the protective film coating liquid 1 was dried using a bar coater on the phosphor layer coated with the water repellent of the previously prepared image conversion screen without protective film. Was coated so as to have a film thickness of 5 μm and dried at 120 ° C. for 30 minutes to form a protective film on the phosphor layer, whereby the radiation image conversion screen 1 was manufactured.

(Examples 2 and 3) Image conversion screen 2 and image conversion screen 3 were operated in the same manner as in Example 1 except that the protective films after drying were applied so that the film thicknesses were 3 μm and 10 μm, respectively. Was manufactured.

(Example 4) [Preparation of coating liquid for protective film] 63 aged product 1 obtained in Example 1 was used.
37 g of OH-containing polyester resin was added to and mixed with g, and the mixture was allowed to stand for 3 hours to obtain a protective film coating solution 2. [Preparation of image conversion screen with protective film] Coating liquid for protective film 1
A protective film-attached image conversion screen 4 was prepared in the same manner as in Example 1 except that the protective film coating solution 2 was used instead of the above.

(Example 5) [Preparation of coating solution for protective film] The aged product 1 obtained in Example 1 was used as 62
38g of acrylic polyol resin is added to and mixed with
After standing for 1 day, a protective film coating solution 3 was obtained. [Preparation of image conversion screen with protective film] Coating liquid for protective film 1
An image conversion screen with a protective film 5 was prepared in the same manner as in Example 1 except that the coating liquid for protective film 3 was used instead of the above.

(Example 6) [Preparation of protective film coating liquid] 1.0 g of vinyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-1003") was further added to the protective film coating liquid 1 as a silane coupling agent. Then, a protective film coating solution 4 was obtained. [Preparation of image conversion screen with protective film] Coating liquid for protective film 1
An image conversion screen 6 with a protective film was prepared in the same manner as in Example 1 except that the protective film coating liquid 6 was used instead of the above.

(Example 7) [Preparation of aged product] "MS-51" of Mitsubishi Chemical Co., Ltd. 30.
84.5 g methanol 14.5 g, ethanol 20.8 g,
27.1 g of propanol were added, followed by 0.3 g of maleic acid and 6.5 g of dechlorinated water. This was left at room temperature for 3 days in a sealed state to obtain an aged product (hereinafter referred to as "aged product 2", silica-concentration 16% by weight). [Preparation of protective film coating liquid] A protective film coating liquid 5 was obtained in the same manner as in Example 1 except that the aged product 2 was used in place of the aged product 1. Using this, an image conversion screen 7 with a protective film was prepared in the same manner as in Example 1.

(Example 8) [Preparation of image conversion screen without protective film] The average particle size was 5
A phosphor coating liquid 2 was prepared by thoroughly mixing 10 parts by weight of a BaFBr: Eu phosphor of 1 μm, 1 part by weight of polyvinyl butyral resin (binder), and a mixed solvent (solvent) of toluene, butyl alcohol, and acetone. Next, the phosphor coating liquid 1
A protective film-less image conversion screen N2 was prepared in the same manner as in Example 1 except that the phosphor coating solution 2 was used instead of the above. [Production of image conversion screen with protective film] An image conversion screen with protective film 8 was produced by the same operation as in Example 1 except that the image conversion screen without protective film N2 was used in place of the image conversion screen without protective film N1. .

Comparative Example 1 Acrylic Silicone Resin 60
g, 30 g of isopropyl alcohol and 1 part of ethyl acetate
0 g was added and mixed, and left for 3 hours to obtain a protective film coating solution R1. Next, the protective film coating liquid 1 is replaced with the protective film coating liquid R1.
An image conversion screen R1 with a protective film was produced by the same operation as in Example 1 except that was used.

(Comparative Example 2) OH-containing polyester resin 3
7 g, diethylene glycol 20 g and acetone 10 g
Were mixed and left for 1 day to obtain a protective film coating solution R2. Next, an image conversion screen R2 with a protective film was prepared in the same manner as in Example 1 except that the protective film coating liquid R2 was used in place of the protective film coating liquid 1.

(Comparative Example 3) Acrylic modified silicone oligomer (Shin-Etsu Chemical Co., Ltd., "X-22-2809") 20
g and 60 g of acrylic silicone resin were mixed and left for 3 hours to obtain a protective film coating solution R3. Next, an image conversion screen R3 with a protective film was produced by the same operation as in Example 1 except that the protective film coating liquid R3 was used in place of the protective film coating liquid 1.

(Comparative Example 4) 20 g of cellulose acetate was dissolved in 180 g of acetone, and they were mixed well and a coating solution R4 for protective film was prepared.
I got Next, instead of the protective film coating liquid 1, the protective film coating liquid R
An image conversion screen R4 with a protective film was prepared in the same manner as in Example 1 except that No. 4 was used.

Comparative Example 5 An image conversion screen with a protective film was obtained by laminating a 6 μm polyethylene terephthalate (PET) film with an adhesive having a thickness of 0.5 μm on the image conversion screen without a protective film obtained in Example 1. R5 was made.

With respect to the image conversion screens 1 to 8 of Examples 1 to 8 and the image conversion screens R1 to R5 of Comparative Examples 1 to 5 obtained as described above, scratch resistance, stain resistance, pinhole coloring and film were obtained. The slipperiness was evaluated. Examples 1 to 7
The image conversion screens 1 to 7 of Comparative Examples 1 to 5 and the image conversion screens R1 to R5 of Comparative Examples 1 to 5 were evaluated for photographic characteristics (photographic sensitivity, sharpness) by using an orthotype film (“Super HR-S30” manufactured by Fuji Photo Film Co., Ltd.). ])). The results are shown in Table 1. The respective characteristic evaluation methods are as follows.

Scratch resistance: 25 on the plate of the dyeing fastness tester
A 25 mm × 25 mm square intensifying screen is fixed, and an ortho film cut into 25 mm × 25 mm square (Fuji Photo Film Co., Ltd. “UR-
1 ") was slid back and forth 2000 times with a load of 20 g, and then the state of the intensifying screen was observed and relatively evaluated.

Contamination resistance: A line was drawn on the surface of the intensifying screen (protective film surface) in a DERMATOGRAPH purple color produced by Mitsubishi Pencil Co., Ltd., and relatively evaluated by the wipeability when wiped with a dry gaze.

Pinhole coloring; intensifying screen surface (protective film surface)
Sandpaper (# 500, # 320, # 240, #
100), after applying a constant pressure, the sandpaper is removed, and an ortho film (“Super HR-S30” manufactured by Fuji Photo Film Co., Ltd.) is placed on the surface of the intensifying screen instead, and a sand paper treatment is performed on this. An ordinary ordinary intensifying screen was placed so that the protective film side was in contact with the ortho film, the temperature was kept at 50 ° C. and the humidity was 58%, and the occurrence of pinhole coloring was observed at regular intervals.

Film slip test: An orthofilm (UR-1 manufactured by Fuji Photo Film Co., Ltd.) was placed on a horizontally set intensifying screen, and the relative angle of the film dropped when the intensifying screen was tilted was evaluated.

Photographic sensitivity: A relative value is shown when the photographic sensitivity of the intensifying screen (R1) of the comparative example is 100.

Sharpness: MTF value of each intensifying screen at a spatial frequency of 2.0 lines / mm is calculated, and M of the increase R1) of the comparative example is obtained.
It is shown as a relative value when the TF value is 100.

[0078]

[Table 1] Sensitivity: Relative value when the sensitivity of the image conversion screen R1 is 100 Sharpness: Relative value when the sharpness of the image conversion screen R1 is 100 Other characteristics: ◎; Especially good, ○; Good, △; Normal , ×; inferior

As can be seen from Table 1, according to the present invention, 1, 4 to
In comparison with the image conversion screens R1 to R4 of the comparative example, No. 7 has almost the same photographic performance with a constant protective film thickness, scratch resistance,
It has excellent stain resistance, durability such as pinhole coloring, and film slipperiness. In the image conversion screen 2 of Example 2 having a small protective film thickness, the photographic performance is particularly excellent, and the scratch resistance and the film slipperiness are good.

Further, in the image conversion screen 3 of Example 3 having a large protective film thickness, the overall performance of scratch resistance, stain resistance, and durability such as pinhole coloring is the best. Furthermore, the image conversion screens of Examples 1 and 8 having the same protective film specifications have different phosphors in the phosphor layer, but have the same durability and slipperiness.
It is similarly superior to the image conversion screens R1 to R4 of the comparative example.

As is clear from comparison between the image conversion screens 1 and R1 and between the image conversion screen 4 and the image conversion screen R2, a liquid obtained by adding a resin to the hydrolyzed condensate of tetramethoxysilane of the present invention. An image conversion screen having a protective film made of a composition is superior in durability and film slipperiness to an image conversion screen having a protective film made of only resin. Further, as can be seen from the comparison between the image conversion screen 1 and the image conversion screen R3, an image conversion having a protective film made of a compound in which another silicone oligomer is added in place of the hydrolytic condensation product of tetramethoxysilane of the present invention. The screen is inferior in durability and film slipperiness to the image conversion screen having the protective film of the present invention.

[0082]

As described above, in the image conversion screen of the present invention, by using the specific liquid composition of the present invention as a coating liquid, the durability such as scratch resistance, stain resistance and the like and film even with a thin protective film thickness can be obtained. It can be made to have excellent slipperiness. Further, the image conversion screen having the specific protective film of the present invention can be more excellent in durability and film slipperiness than conventional image conversion screens having a protective film made of a resin alone. Further, compared with the case where a silicone oligomer other than the hydrolyzed condensate of tetramethoxysilane such as the liquid composition of the present invention is used as the silicon component, durability such as scratch resistance and stain resistance and film slippage are obtained. It is possible to obtain an image conversion screen having excellent properties.

[Brief description of drawings]

FIG. 1 Measurement data of scattering intensity of composition A

FIG. 2 Measurement data of scattering intensity of composition B

FIG. 3 Point beam data of Composition A after slit correction

FIG. 4 Point beam data of Composition B after slit correction

FIG. 5: Distribution of the radius of gyration of the microparticles in composition A

FIG. 6 Distribution of radii of gyration of fine particles in composition B

FIG. 7: Distribution of assumed spherical spheres of fine particles in composition A

FIG. 8: Assumed sphere distribution of fine particles of composition B

FIG. 9: “MS-51” used as a raw material in Example 1
Scattering intensity measurement data

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumiya Ishikawa 2-5-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Chemical Co., Ltd. New Business Development Room (72) Hideo Suzuki 1060 Narita, Odawara-shi, Kanagawa Kasei Optonics Co., Ltd. Odawara Plant (72) Inventor Takeshi Akiwa 1060 Narita, Odawara City, Kanagawa Kasei Optonix Co., Ltd. Odawara Plant

Claims (9)

[Claims] 1. A radiation image conversion screen having at least a phosphor layer and a protective film on a support, wherein the protective film is an aged product obtained by adding water to tetramethoxysilane and aging it for hydrolysis and condensation reaction. And a reactive organic compound having two or more functional groups capable of undergoing a condensation reaction with the hydrolyzed condensate of tetramethoxysilane in the aged product, which is obtained by applying and drying the liquid composition. A radiation image conversion screen characterized in that 2. The radiation image conversion screen according to claim 1, wherein one or more kinds of silane coupling agents shown below are used as the reactive organic compound. Embedded image γ-methacryloxypropyltrimethoxysilane embedded image γ-glycidoxypropyltrimethoxysilane β- (3.4 epoxycyclohexyl) ethyltrimethoxysilane embedded image Vinyltrimethoxysilane vinylitriethoxysilane Vinyl tris (β-methoxyethoxy) silane embedded image γ-aminopropyltriethoxysilane N-β (aminoethyl) γ-aminopropyltrimethoxysilane embedded image Gamma-ureidopropyltriethoxysilane embedded image Methyltrimethoxysilane dimethyldimethoxysilane Embedded image γ-mercaptopropyltrimethoxysilane 3. The reactive organic compound comprises one or more of polyester polyol, acrylic polyol, silicone modified acrylic, nitrification cotton, vinyl chloride-vinyl acetate copolymer and polyvinyl alcohol. The radiation image conversion screen according to claim 1 or claim 2. 4. The content of silicon in terms of SiO ₂ in the protective film is 1
The radiation image conversion screen according to claim 1, wherein the radiation image conversion screen is from 0 to 90% by weight. 5. A part or all of the hydrolyzed condensate of tetramethoxysilane in the aged product forms fine particles having an inertia radius of 40 Å or less. Radiation image conversion screen. 6. An aged product obtained by hydrolyzing and condensing tetramethoxysilane by adding water and a functional group capable of undergoing a condensation reaction with the hydrolytic condensate of tetramethoxysilane in the aged product. A composition for forming a protective film for a radiation image conversion screen, which is prepared by blending the reactive organic compound. 7. The composition for forming a radiation image conversion screen protective film according to claim 6, wherein one or more kinds of the following silane coupling agents are used as the reactive organic compound. Embedded image γ-methacryloxypropyltrimethoxysilane embedded image γ-glycidoxypropyltrimethoxysilane β- (3.4 epoxycyclohexyl) ethyltrimethoxysilane embedded image vinyltrimethoxysilane vinylitriethoxysilane Vinyltris (β-methoxyethoxy) silane embedded image γ-aminopropyltriethoxysilane N-β (aminoethyl) γ-aminopropyltrimethoxysilane γ-ureidopropyltriethoxysilane embedded image Methyltrimethoxysilane dimethyldimethoxysilane Embedded image γ-mercaptopropyltrimethoxysilane 8. The reactive organic compound comprises one or more of polyester polyol, acrylic polyol, silicone modified acrylic, nitrification cotton, vinyl chloride-vinyl acetate copolymer and polyvinyl alcohol. The composition for forming a radiation image conversion screen protective film according to claim 6 or claim 7. 9. The hydrolyzed condensate of tetramethoxysilane in the aged product is partially or wholly formed in the form of fine particles having an inertia radius of 10 Å or less. The composition for forming a radiation image conversion screen protective film of.