WO2016167278A1 - X-ray recording material, method for manufacturing x-ray recording material, x-ray recording medium, recording method using x-ray recording medium, and method for measuring x-ray radiation dose - Google Patents

X-ray recording material, method for manufacturing x-ray recording material, x-ray recording medium, recording method using x-ray recording medium, and method for measuring x-ray radiation dose Download PDF

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WO2016167278A1
WO2016167278A1 PCT/JP2016/061891 JP2016061891W WO2016167278A1 WO 2016167278 A1 WO2016167278 A1 WO 2016167278A1 JP 2016061891 W JP2016061891 W JP 2016061891W WO 2016167278 A1 WO2016167278 A1 WO 2016167278A1
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ray
ray recording
recording material
recording medium
silicate compound
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PCT/JP2016/061891
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French (fr)
Japanese (ja)
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浩志 山田
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国立研究開発法人産業技術総合研究所
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K9/00—Tenebrescent materials, i.e. materials for which the range of wavelengths for energy absorption is changed as a result of excitation by some form of energy
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/02—Dosimeters
    • G01T1/04—Chemical dosimeters
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens

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  • the present invention relates to an X-ray recording material, a method for producing an X-ray recording material, an X-ray recording medium, a recording method using an X-ray recording medium, and a method for measuring an X-ray irradiation amount.
  • the X-ray recording material that can be used repeatedly, has durability, and has excellent practicality, a method for producing the X-ray recording material, an X-ray recording medium, a recording method using the X-ray recording medium, and measurement of the X-ray irradiation amount It concerns the method.
  • X-ray and other radiation imaging technology is widely used.
  • X-ray imaging technology is used in a wide range of fields such as non-destructive inspection, medical diagnosis, film batch, and autoradiography.
  • an X-ray imaging technique there are an X-ray film, an imaging plate, and an X-ray camera.
  • the X-ray film increases the content of silver halide, which is a photosensitive substance, compared with ordinary photographic film, and obtains sufficient sensitivity and contrast for X-ray irradiation. In addition, by using together with fluorescent intensifying screens, higher sensitivity is realized.
  • the imaging plate is formed by applying photostimulable phosphor microcrystals to a sheet or the like as a support.
  • photostimulable phosphor microcrystals When the surface exposed to X-rays is irradiated with helium neon laser light, light emission corresponding to the X-ray exposure amount occurs, and by measuring this light emission amount, an X-ray image proportional to the X-ray irradiation amount can be acquired. .
  • the X-ray camera can detect the incident position and measure the energy of incident X-rays using a CCD or CMOS as a photosensitive element.
  • the X-ray film is excellent in cost and can be used even in a severe use environment, but cannot be used repeatedly.
  • instant properties are difficult because a film development process is required.
  • the imaging plate has the advantage that it can be used repeatedly and digital image data can be obtained, but it is not suitable for in-situ shooting because a dedicated and expensive reading device is required.
  • X-ray cameras are suitable for precision shooting with video shooting and high dynamic range, but the equipment is expensive and precise electronic components are used, so the usage environment and scenes are limited. It has become.
  • an organic photochromic material is used instead of silver halide used in an X-ray film.
  • a photochromic material is a material that exhibits a kind of reversible property, that is, photochromism, which changes color when a substance is irradiated with light, and reverses color when irradiated or heated to a substance that has changed color.
  • Photochromic materials have already been put to practical use in sunglasses and the like, and in the future, application to optical memories, switching elements, optical elements, light control glasses, color displays, and the like are being studied.
  • Patent Document 1 and Patent Document 2 propose a radiation indicator that can be used repeatedly by using a photochromic material made of an organic substance.
  • Patent Document 1 and Patent Document 2 are composed of organic materials, the chemical and thermal stability is low, and the chemical species itself is likely to deteriorate due to repeated isomerization. There was a problem such as.
  • organic materials do not cause photochromic phenomenon after crystallization or dispersion in a polymer even if photochromic phenomenon occurs in a liquid state. Sometimes.
  • the present invention was devised in view of the above points, and can be used repeatedly, has durability, is excellent in practicality, a method for producing an X-ray recording material, an X-ray recording medium, It is an object of the present invention to provide a recording method using an X-ray recording medium and a method for measuring an X-ray irradiation dose.
  • the X-ray recording material of the present invention contains a silicate compound exhibiting photochromic properties.
  • the silicate compound exhibiting photochromic properties can be repeatedly attached and detached by X-ray irradiation and heating.
  • it is composed of an inorganic material and has a chemically and thermally stable structure.
  • it is not necessary to dissolve in a solvent as in the case of organic substances, and it can be used as a solid.
  • the photochromic property here includes not only coloring by X-rays and decoloring by heating but also coloring by ultraviolet rays and decoloring by visible light.
  • the silicate compound contains at least barium and magnesium, it has a basic structure of tetrahedral SiO 4 and MgO 4 and a crystal structure in which Ba is inserted into voids of these basic skeletons.
  • the composition can improve the photochromic characteristics. More specifically, when Mg is substituted with Fe or Al, it contributes to an improvement in sensitivity to X-rays, an improvement in coloring strength, and an extension of the holding time of the colored state. Further, when Si is substituted with B, it contributes to an improvement in coloring strength.
  • the method for producing an X-ray recording material of the present invention comprises a powdery material containing a silicate compound exhibiting photochromic properties in a reducing atmosphere of 1150 ° C. to 1300 ° C. for 2 hours.
  • the process of baking is provided.
  • the silicate compound exhibiting photochromic properties can be repeatedly attached and detached by X-ray irradiation and heating.
  • it is composed of an inorganic material and has a chemically and thermally stable structure. Furthermore, it is not necessary to dissolve in a solvent as in the case of organic substances, and it can be used as a solid.
  • a crystal phase exhibiting photochromic properties can be sufficiently formed.
  • the target crystal phase may not be formed or may be formed only insufficiently.
  • the target crystal phase is not formed or the material is melted.
  • the X-ray recording medium of the present invention has a recording layer in which an X-ray recording material containing a silicate compound exhibiting photochromic properties is uniformly blended and is rewritable. It is configured.
  • an image obtained by irradiating X-rays can be recorded by having a recording layer in which an X-ray recording material containing a silicate compound exhibiting photochromic properties is uniformly blended. That is, for example, an object is placed between an X-ray generation source and a recording layer and irradiated with X-rays, whereby a transmitted X-ray image inside the object can be obtained.
  • the X-ray recording material containing a photosilicate silicate compound is blended and rewritable, so that the X-ray image obtained by coloring can be erased and used repeatedly.
  • the X-ray irradiation fluoresces and at least part of the wavelength range of the emission spectrum contains a scintillator that overlaps the wavelength range of the absorbance spectrum exhibited by the silicate compound, the sensitivity to X-rays is increased. This can be further improved. That is, the scintillator irradiated with X-rays generates light of a certain wavelength, and the silicate compound absorbs the emitted light, which works favorably for coloring.
  • the recording method using the X-ray recording medium of the present invention is an X-ray recording material containing a silicate compound exhibiting photochromic properties, and is configured to be decolored by heating.
  • the X-ray recording medium is colored by irradiation with X-rays having a wavelength in the range of 0.001 to 10 nm.
  • an X-ray recording medium composed of an X-ray recording material containing a silicate compound exhibiting photochromic properties is irradiated with X-rays in the wavelength range of 0.001 to 10 nm to color the X-rays.
  • the recording material can be colored by irradiation to obtain and record an X-ray image.
  • the recording medium is composed of an inorganic material, and chemical and thermal stable recording is possible.
  • an X-ray recording material containing a silicate compound exhibiting photochromic properties, and an X-ray image recorded on the recording material can be erased by an X-ray recording medium configured to be decolored by heating, and repeated recording Is a possible method.
  • the X-ray irradiation measuring method of the present invention is applied to an X-ray recording medium comprising an X-ray recording material containing a silicate compound exhibiting photochromic properties at a wavelength of 0.
  • the X-ray recording medium composed of an X-ray recording material containing a silicate compound exhibiting photochromic properties is irradiated with X-rays having a wavelength in the range of 0.001 to 10 nm to color the X-rays.
  • the recording material can be colored by this irradiation, and information on the coloring amount for calculating the X-ray irradiation amount to be detected can be obtained.
  • a simple X-ray irradiation amount to be detected can be measured by a detection step of detecting the X-ray irradiation amount from the coloring amount of the X-ray recording material obtained in the coloring step. More specifically, a calibration curve between the X-ray irradiation amount and the coloring amount in the X-ray recording material is prepared in advance, and the target X-ray irradiation amount is calculated from the coloring amount and the calibration curve recorded in the recording material. Can be decided.
  • the X-ray recording material according to the present invention is reusable and durable, and has excellent practicality.
  • the method for producing an X-ray recording material according to the present invention is capable of producing an X-ray recording material that can be used repeatedly, has durability, and has excellent practicality.
  • the X-ray recording medium according to the present invention is reusable and durable, and has excellent practicality.
  • the method for producing an X-ray recording medium according to the present invention can produce an X-ray recording medium that can be used repeatedly, has durability, and is highly practical.
  • the method for measuring an X-ray irradiation amount according to the present invention provides a method for measuring an X-ray irradiation amount that can be used repeatedly, has durability, and has excellent practicality.
  • the photochromic material that is the X-ray recording material of the present invention has the following formula (a): Ba (Mg 1-x-y Fe x Al y) (Si 1-z B z) O 4 ⁇ (a) (In the formula, 0 ⁇ x ⁇ 0.01, 0 ⁇ y ⁇ 0.10, and 0 ⁇ z ⁇ 0.20.) It has the composition represented by these. This material is based on barium magnesium silicate with a skeleton of SiO 4 —MgO 4 network structure.
  • silicon ions (Si 4+ ) in the SiO 4 tetrahedron are replaced with magnesium ions (Mg 2+ ) at a certain ratio.
  • Magnesium ions (Mg 2+ ) are sites where iron ions (Fe 2+ ) and aluminum ions (Al 3+ ) are bonded.
  • silicon ions (Si 4+ ) are sites to which boron ions (B 3+ ) are bonded.
  • the substance exhibits a photochromism property of being colored purplish to X-ray irradiation in a wavelength range of 0.001 nm to 10 nm.
  • the substance is colored not only by X-ray irradiation but also by ultraviolet irradiation.
  • This material has high heat resistance in a colored state by X-ray irradiation, and can maintain a discolored state up to, for example, about 100 ° C. Further, the colored state can be maintained for a long time, for example, several hundred days.
  • the original material colored by X-ray irradiation can be decolorized again by irradiating it with green light (for example, wavelength 532 nm) or heating.
  • green light for example, wavelength 532 nm
  • the X-ray recording material can be used repeatedly.
  • coloring and decoloring are repeated in this substance, sufficient coloring strength is obtained and it is difficult to deteriorate. This point will be described in detail in the embodiments described later.
  • X in the above formula (a) is preferably in the range of 0 ⁇ x ⁇ 0.01. Further, y is preferably in the range of 0 ⁇ y ⁇ 0.10. Within the range in the formula (a), the photochromism characteristics of the X-ray recording material can be improved.
  • Z in the above formula (a) is preferably in the range of 0 ⁇ z ⁇ 0.20. Within the range in the formula (a), the photochromism characteristics of the X-ray recording material can be improved.
  • the strongest X-ray peak intensity of the BaMgSiO 4 phase is twice or more the X-ray peak intensity of the other crystal layers.
  • the raw material containing Ba element includes barium carbonate, barium sulfate, barium oxide, barium nitrate, barium hydroxide, barium silicide, and barium borate.
  • the raw material containing Mg element include magnesium carbonate and magnesium oxide.
  • the raw material containing Si element include silicon and silicon oxide.
  • examples of the raw material containing the O element include the various oxides described above.
  • examples of the raw material containing Fe element include iron oxides having various oxidation numbers.
  • examples of the raw material containing Al include aluminum oxide and aluminum acetate.
  • the mixture of photochromic materials may further contain other substances in addition to the above raw materials as long as the photochromism is not inhibited.
  • the X-ray recording material of the present invention may contain a scintillator in addition to the photochromic material.
  • a scintillator is a phosphor that emits an arbitrary wavelength in response to X-ray irradiation.
  • the photochromic material represented by the above formula (a) has the greatest sensitivity to light having a wavelength of 250 nm, and this sensitivity is greater than the sensitivity to X-ray irradiation.
  • the sensitivity of the X-ray recording material to X-ray irradiation can be improved by using a scintillator that emits fluorescence in a wavelength band including 250 nm together with the photochromic material by X-ray irradiation.
  • Examples of the scintillator used in combination with the photochromic material represented by the above formula (a) include pure cesium iodide (CsI: emission peak wavelength 315 nm) and barium fluoride (BaF 2 : emission peak wavelengths 210 nm, 310 nm). Note that the type of scintillator is not limited to this, and can be appropriately selected as long as the sensitivity to X-rays can be improved.
  • the X-ray recording material of the present invention is produced by firing a powdery material containing a photochromic material having the composition represented by the above formula (a) in a reducing atmosphere at 1150 ° C. to 1300 ° C. for 2 hours or more.
  • the firing step for example, by adding boric acid to the photochromic material, it can be processed in a reducing atmosphere.
  • the content of boric acid to be added is not particularly limited, but is in the range of 2 to 10 mol% with respect to the Ba contained in the raw material containing Ba in the photochromic material represented by the above formula (a). An amount is preferred.
  • the photochromic material represented by the above formula (a) may be further mixed with a solvent such as ethyl alcohol so that each raw material and boric acid are more uniformly mixed.
  • a solvent such as ethyl alcohol
  • the mixing method of each raw material, boric acid, a solvent, etc. is sufficient if it is a method by which a uniform mixture is obtained, and the kind of mixing method is not specifically limited.
  • the step of firing the powdery body containing the photochromic material is more preferably performed in a reducing atmosphere, and more preferably in the presence of hydrogen gas.
  • Specific examples of the firing method include a method of firing the mixture in a mixed gas stream of an inert gas such as argon gas and a reducing gas such as hydrogen gas.
  • the concentration of hydrogen gas in the mixed gas is preferably in the range of 2 to 10% by volume.
  • the firing conditions include conditions of firing at 1150 ° C. to 1300 ° C. for 2 hours. By performing the firing treatment under these conditions, a fired product in which a crystal phase exhibiting photochromic properties is sufficiently formed can be obtained.
  • a commercially available apparatus can be used as the baking apparatus.
  • the firing conditions are not necessarily limited to the temperature range of 1150 ° C to 1300 ° C.
  • the firing condition is in a temperature range of 1150 ° C. to 1300 ° C. from the viewpoint that the material is difficult to melt and a crystal phase exhibiting photochromic properties can be sufficiently formed. .
  • the firing condition is not necessarily limited to the condition of firing at 1150 ° C. to 1300 ° C. for 2 hours.
  • the firing conditions are preferably those for firing at 1150 ° C. to 1300 ° C. for 2 hours.
  • a fired product of a powdery body formed so as to have a certain shape such as a plate shape can be used as it is.
  • the shape after firing is not particularly limited, and can be appropriately selected according to the size and shape of an object for which an X-ray transmission image is desired.
  • the X-ray recording material can be structured such that a liquid component containing a photochromic material is coated on a substrate of an arbitrary material and a recording layer is provided on the substrate.
  • a recording layer is provided on the substrate, for example, an appropriate amount of the above-described photochromic material is dispersed in a vehicle, and a uniform pressure film is formed on the substrate by a known thin film forming method such as a doctor blade method.
  • the material of the substrate on which the recording layer is formed is not particularly limited, and may be appropriately selected according to the use of the X-ray recording material, such as glass, resin, metal and the like.
  • the X-ray recording material may have a structure in which a recording layer is formed on a substrate.
  • the X-ray recording medium to which the present invention is applied can be manufactured by the photochromic material and the X-ray recording medium manufacturing method described above.
  • Example 1 A sample of Example 1 was prepared using the photochromic material and manufacturing method described above.
  • a powdery material having a composition of the photochromic material Ba (Mg 1-xy Fe x Al y ) (Si 1-z Bz) O 4 was used as a raw material.
  • the powdery body was molded into a circle and then fired in a reducing atmosphere.
  • the baking treatment was performed for 2 hours in the temperature range of 1150 ° C to 1300 ° C.
  • the fired product was in the form of a tablet having a flat and circular outer periphery, and the following confirmation was performed using this as an X-ray recording medium.
  • Fig. 1 shows an apparatus configuration for obtaining an X-ray transmission image of an object.
  • the apparatus configuration 1 has an X-ray source 2, a slit 3, and an X-ray recording pellet 4 showing photochromic properties that is Example 1.
  • the X-ray source 2 a sealed tube X-ray generator using Cu as a target was used.
  • An object to be irradiated with X-rays was placed at position 5 on the front surface of the X-ray recording pellet 4.
  • 1A shows an X-ray irradiation area 6 and an ultraviolet-visible spectroscopy measurement area 7 on the surface of the X-ray recording pellet 4.
  • X-rays (symbol X) irradiated from the X-ray source 2 are irradiated to an object 8 for which an X-ray transmission image is to be obtained.
  • Part of the X-rays transmitted through the object 8 is absorbed inside the object 8, and X-rays having an intensity distribution are irradiated to the X-ray recording pellet 4.
  • the X-ray recording pellet 4 is colored reddish purple by X-ray irradiation, and a transmission image 9 is obtained.
  • the X-ray recording pellet 4 was irradiated with X-rays without arranging the object 8. X-ray irradiation was performed for 2 hours under conditions of an output of 40 kV and 20 mA. Further, the X-ray recording pellet 4 after X-ray irradiation was left in an electric furnace heated to 250 ° C. for 10 minutes. The absorption spectra of the X-ray recording pellet 4 after X-ray irradiation and the X-ray recording pellet 4 after heating were confirmed with a UV-VIS-NIR spectrophotometer. FIG. 2 shows an absorption spectrum.
  • the sample after X-ray irradiation had an absorption spectrum (reference numeral 10) having a peak at a wavelength of 520 nm, and it was confirmed that the sample was colored reddish purple from the white state before coloring. Moreover, the sample after heating became an absorption spectrum (symbol 11) in which the peak at a wavelength of 520 nm disappeared, and it was confirmed that the reddish purple color was decolored to be the original white color. As described above, the sample of Example 1 was colored with X-rays and exhibited photochromism that was decolorized by heating. Moreover, it became clear that it can be used repeatedly by coloring and decoloring.
  • the X-ray recording medium of Example 1 did not show a decrease in the peak intensity at a wavelength of 520 nm even at 20 measurement points. Further, although not shown in FIG. 3, the peak intensity at the same level as the initial measurement was maintained even after the 200th measurement. That is, the X-ray recording medium of Example 1 has sufficient sensitivity to X-rays even when it is used repeatedly, and has durability capable of acquiring a reproducible X-ray transmission image. Became clear.
  • Example 2 (6) X-ray output and irradiation time
  • the X-ray recording medium of Example 1 was irradiated with X-rays having different outputs, and the absorbance at a wavelength of 520 nm was monitored at each irradiation time.
  • the output of X-rays was set at three stages of 30 mA (reference numeral 12), 20 mA (reference numeral 13), and 10 mA (reference numeral 14) at 40 kV.
  • FIG. 4 shows the results of monitoring absorbance at a wavelength of 520 nm. Further, the lower right of FIG. 4 shows a logarithmic display of the left graph of FIG.
  • the X-ray irradiation dose can be easily quantified from the coloring amount by creating a calibration curve for the X-ray irradiation amount and the coloring amount of the X-ray recording medium.
  • the X-ray recording medium of the present invention can be used not only for recording X-ray transmission images but also as a measuring method.
  • Examples 2 to 8 Samples of Examples 2 to 8 shown in Table 1 below were prepared using the photochromic material and manufacturing method described above.
  • FIG. 5 is a graph showing the relationship between the measurement time and the absorbance at a wavelength of 520 nm in each example.
  • FIG. 6 is a graph showing the results shown in FIG. 5 in common logarithm.
  • Reference numeral 16 corresponds to the second embodiment (BMSFAB1)
  • reference numeral 17 corresponds to the third embodiment (BMSFAB2)
  • reference numeral 18 corresponds to the fourth embodiment (BMSB)
  • reference numeral 19 corresponds to the fifth embodiment (BMSAB).
  • FIG. 7 shows an absorption spectrum.
  • Reference numeral 21 is the second embodiment (BMSFAB1)
  • reference numeral 20 is the third embodiment (BMSFAB2)
  • reference numeral 22 is the fourth embodiment (BMSB)
  • reference numeral 23 is the fifth embodiment (BMSAB)
  • reference numeral 24 is the sixth embodiment (BMSF).
  • 25 corresponds to Example 7 (BMS)
  • 26 corresponds to Example 8 (BMSA).
  • Example 2 As shown in FIG. 7, at the wavelength of 520 nm, Example 2 (BMSFAB1) and Example 3 (BMSFAB2) had the highest peak, and the coloring intensity was large. Further, from the results of Examples 2 to 8, it has been clarified that the effect of the addition on the coloring strength is influenced in the order of B, Fe and Al addition> B addition> Fe addition> Al addition.
  • the X-ray recording material according to the present invention is reusable and durable, and has excellent practicality.
  • the method for producing an X-ray recording material according to the present invention is capable of producing an X-ray recording material that can be used repeatedly, has durability, and has excellent practicality.
  • the X-ray recording medium according to the present invention is reusable and durable, and has excellent practicality.
  • the method for producing an X-ray recording medium according to the present invention can produce an X-ray recording medium that can be used repeatedly, has durability, and is highly practical.
  • the method for measuring an X-ray irradiation amount according to the present invention provides a method for measuring an X-ray irradiation amount that can be used repeatedly, has durability, and has excellent practicality.
  • Example 4 in logarithm 16
  • Example 2 BMSFAB1 17
  • Example 3 BMSFAB2) 18
  • Example 4 BMSB 19
  • Example 5 BMSAB 20
  • Example 3 BMSFAB2) 21
  • Example 2 BMSFAB1 22
  • Example 4 BMSB 23
  • Example 5 BMSAB 24
  • Example 6 BMSF 25
  • Example 7 BMS 26
  • Example 8 BMSA

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Abstract

[Problem] To provide a durable X-ray recording material capable of repeated use and having excellent practicality, a method for manufacturing an X-ray recording material, an X-ray recording medium, a recording method using the X-ray recording medium, and a method for measuring an X-ray radiation dose. [Solution] This photochromic material as an X-ray recording material has a composition represented by formula (a): Ba(Mg1 – x – yFexAly)(Si1 – zBz)O4 (where 0 ≤ x < 0.01, 0 ≤ y < 0.10, and 0 ≤ z < 0.20). This substance is based on barium magnesium silicate having a skeleton having a SiO4-MgO4 network structure.

Description

Ｘ線記録材料、Ｘ線記録材料の製造方法、Ｘ線記録媒体、Ｘ線記録媒体による記録方法及びＸ線照射量の測定方法X-ray recording material, method for producing X-ray recording material, X-ray recording medium, recording method using X-ray recording medium, and method for measuring X-ray irradiation dose
　本発明はＸ線記録材料、Ｘ線記録材料の製造方法、Ｘ線記録媒体、Ｘ線記録媒体による記録方法及びＸ線照射量の測定方法に関する。詳しくは、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線記録材料、Ｘ線記録材料の製造方法、Ｘ線記録媒体、Ｘ線記録媒体による記録方法及びＸ線照射量の測定方法に係るものである。 The present invention relates to an X-ray recording material, a method for producing an X-ray recording material, an X-ray recording medium, a recording method using an X-ray recording medium, and a method for measuring an X-ray irradiation amount. Specifically, the X-ray recording material that can be used repeatedly, has durability, and has excellent practicality, a method for producing the X-ray recording material, an X-ray recording medium, a recording method using the X-ray recording medium, and measurement of the X-ray irradiation amount It concerns the method.
　Ｘ線をはじめとする放射線の画像化技術が広く利用されている。特にＸ線イメージング技術は、非破壊検査、医療診断、フィルムバッチ、オートラジオグラフィ等、幅広い分野で用いられている。 X-ray and other radiation imaging technology is widely used. In particular, X-ray imaging technology is used in a wide range of fields such as non-destructive inspection, medical diagnosis, film batch, and autoradiography.
　例えば、Ｘ線イメージング技術として、Ｘ線フィルム、イメージングプレート及びＸ線カメラが存在する。 For example, as an X-ray imaging technique, there are an X-ray film, an imaging plate, and an X-ray camera.
　Ｘ線フィルムは、通常の写真フィルムよりも感光性物質であるハロゲン化銀の含有率を増やし、Ｘ線の照射に対して充分な感度とコントラストを得るものとなっている。また、蛍光増感紙と併用することで、更なる高感度化を実現している。 The X-ray film increases the content of silver halide, which is a photosensitive substance, compared with ordinary photographic film, and obtains sufficient sensitivity and contrast for X-ray irradiation. In addition, by using together with fluorescent intensifying screens, higher sensitivity is realized.
　イメージングプレートは、輝尽性蛍光体の微結晶を支持体となるシート等に塗布して形成される。Ｘ線により露光された表面にヘリウムネオンレーザー光を照射すると、Ｘ線の露光量に応じた発光が生じ、この発光量を計測することで、Ｘ線照射量に比例したＸ線画像を取得できる。 The imaging plate is formed by applying photostimulable phosphor microcrystals to a sheet or the like as a support. When the surface exposed to X-rays is irradiated with helium neon laser light, light emission corresponding to the X-ray exposure amount occurs, and by measuring this light emission amount, an X-ray image proportional to the X-ray irradiation amount can be acquired. .
　Ｘ線カメラは、感光素子として、ＣＣＤやＣＭＯＳを利用して、入射するＸ線について入射位置の検出と、エネルギーの測定が可能となっている。 The X-ray camera can detect the incident position and measure the energy of incident X-rays using a CCD or CMOS as a photosensitive element.
　ここで、Ｘ線フィルムは、コスト性に優れ、過酷な使用環境下でも利用しうるが、繰り返しの使用ができないものとなっている。また、フィルムの現像プロセスが必要な点からインスタント性に難点を有している。 Here, the X-ray film is excellent in cost and can be used even in a severe use environment, but cannot be used repeatedly. In addition, instant properties are difficult because a film development process is required.
　また、イメージングプレートは、繰り返し使用可能でデジタル画像データが得られる利点を有するが、専用かつ高価な読み取り装置が必要な点から、その場での撮影には不向きなものとなっている。 The imaging plate has the advantage that it can be used repeatedly and digital image data can be obtained, but it is not suitable for in-situ shooting because a dedicated and expensive reading device is required.
　Ｘ線カメラは、動画撮影や、高いダイナミックレンジを有し精密測定には適しているが、装置が高価であり、精密な電子部品が使用されているため、使用環境や場面が限定されるものとなっている。 X-ray cameras are suitable for precision shooting with video shooting and high dynamic range, but the equipment is expensive and precise electronic components are used, so the usage environment and scenes are limited. It has become.
　Ｘ線イメージング技術の用途のうち、非破壊検査等の現場においては、繰り返し利用可能であり、コスト性に優れ、すぐにＸ線透過画像が確認できる簡易な撮影技術の開発が強く望まれている。 Among the uses of X-ray imaging technology, there is a strong demand for the development of simple imaging technology that can be used repeatedly in the field such as non-destructive inspection, is cost-effective, and can immediately confirm X-ray transmission images. .
　こうしたなか、記録媒体に有機フォトクロミック材料を用い、既存のＸ線イメージング技術が抱える問題の解決を試みた技術が提案され、例えば、特許文献１及び特許文献２に記載のフォトクロミック組成物が存在する。 Under such circumstances, there has been proposed a technique that uses an organic photochromic material for a recording medium and attempts to solve the problems of existing X-ray imaging techniques. For example, there are photochromic compositions described in Patent Document 1 and Patent Document 2.
　特許文献１及び特許文献２には、Ｘ線フィルムで用いられるハロゲン化銀の代わりに、有機フォトクロミック材料が用いられている。フォトクロミック材料とは、物質に光を照射すると変色し、逆に変色した物質に他の光を照射又は加熱すると退色して元に戻る一種の可逆的な性質、即ちフォトクロミズムを示す材料である。 In Patent Document 1 and Patent Document 2, an organic photochromic material is used instead of silver halide used in an X-ray film. A photochromic material is a material that exhibits a kind of reversible property, that is, photochromism, which changes color when a substance is irradiated with light, and reverses color when irradiated or heated to a substance that has changed color.
　フォトクロミック材料は、すでにサングラスなどに実用化されており、今後は、光メモリー、スイッチング素子、光学素子、調光ガラスおよびカラーディスプレイなどへの応用が検討されている。 Photochromic materials have already been put to practical use in sunglasses and the like, and in the future, application to optical memories, switching elements, optical elements, light control glasses, color displays, and the like are being studied.
　特許文献１及び特許文献２では、有機物からなるフォトクロミック材料を用いて、繰り返し使用可能な放射線インジケータが提案されている。 Patent Document 1 and Patent Document 2 propose a radiation indicator that can be used repeatedly by using a photochromic material made of an organic substance.
特開２００５－８７５３号公報Japanese Patent Laying-Open No. 2005-8753 特開２００５－８７５４号公報JP 2005-8754 A
　しかしながら、特許文献１及び特許文献２に記載されたフォトクロミック材料は、有機材料で構成されることから、化学的及び熱的な安定性が低く、異性化の繰り返しによる化学種そのものの劣化が生じ易い等の問題があった。 However, since the photochromic materials described in Patent Document 1 and Patent Document 2 are composed of organic materials, the chemical and thermal stability is low, and the chemical species itself is likely to deteriorate due to repeated isomerization. There was a problem such as.
　また、有機材料の中には、液体状態ではフォトクロミック現象を生じても、結晶化した後、または高分子中に分散させた後にはフォトクロミック現象を生じない材料があり、使用形態によっては問題が生じることがある。 In addition, some organic materials do not cause photochromic phenomenon after crystallization or dispersion in a polymer even if photochromic phenomenon occurs in a liquid state. Sometimes.
　本発明は、以上の点に鑑みて創案されたものであり、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線記録材料、Ｘ線記録材料の製造方法、Ｘ線記録媒体、Ｘ線記録媒体による記録方法及びＸ線照射量の測定方法を提供することを目的とする。 The present invention was devised in view of the above points, and can be used repeatedly, has durability, is excellent in practicality, a method for producing an X-ray recording material, an X-ray recording medium, It is an object of the present invention to provide a recording method using an X-ray recording medium and a method for measuring an X-ray irradiation dose.
　上記の目的を達成するために、本発明のＸ線記録材料は、フォトクロミック性を示すケイ酸塩化合物を含有している。 In order to achieve the above object, the X-ray recording material of the present invention contains a silicate compound exhibiting photochromic properties.
　ここで、フォトクロミック性を示すケイ酸塩化合物によって、Ｘ線の照射と加熱で、繰り返して着脱色させることが可能となる。また、無機材料で構成されるものとなり、化学的及び熱的に安定な構造となる。更に、有機物のように溶媒に溶かす必要がなく、固体での利用が可能となる。なお、ここでいうフォトクロミック性とは、Ｘ線による着色及び加熱による脱色だけでなく、紫外線による着色と可視光線による脱色の性質も含むものである。 Here, the silicate compound exhibiting photochromic properties can be repeatedly attached and detached by X-ray irradiation and heating. In addition, it is composed of an inorganic material and has a chemically and thermally stable structure. Furthermore, it is not necessary to dissolve in a solvent as in the case of organic substances, and it can be used as a solid. The photochromic property here includes not only coloring by X-rays and decoloring by heating but also coloring by ultraviolet rays and decoloring by visible light.
　また、ケイ酸塩化合物が少なくともバリウム及びマグネシウムを含有する場合には、ＳｉＯ４及びＭｇＯ４の四面体の基本骨格と、これら基本骨格の空隙にＢａが挿入された結晶構造を有するものとなる。 Further, when the silicate compound contains at least barium and magnesium, it has a basic structure of tetrahedral SiO 4 and MgO 4 and a crystal structure in which Ba is inserted into voids of these basic skeletons.
　また、ケイ酸塩化合物の骨格を構成するＳｉＯ４－ＭｇＯ４ネットワーク構造のＳｉ及びＭｇの少なくとも一部がＦｅ、ＢまたはＡｌから選択される少なくとも１つの元素で置換された場合には、組成物のフォトクロミズム特性を向上させることができる。より詳細には、ＭｇがＦｅまたはＡｌで置換されると、Ｘ線への感度の向上、着色強度の向上、着色状態の保持時間の伸長に寄与するものとなる。また、ＳｉがＢで置換されると、着色強度の向上に寄与するものとなる。 Further, when at least a part of Si and Mg in the SiO 4 —MgO 4 network structure constituting the skeleton of the silicate compound is substituted with at least one element selected from Fe, B, or Al, the composition Can improve the photochromic characteristics. More specifically, when Mg is substituted with Fe or Al, it contributes to an improvement in sensitivity to X-rays, an improvement in coloring strength, and an extension of the holding time of the colored state. Further, when Si is substituted with B, it contributes to an improvement in coloring strength.
　また、上記の目的を達成するために、本発明のＸ線記録材料の製造方法は、フォトクロミック性を示すケイ酸塩化合物を含有する粉状体を１１５０℃～１３００℃の還元雰囲気下で２時間以上焼成する工程を備える。 In order to achieve the above object, the method for producing an X-ray recording material of the present invention comprises a powdery material containing a silicate compound exhibiting photochromic properties in a reducing atmosphere of 1150 ° C. to 1300 ° C. for 2 hours. The process of baking is provided.
　ここで、フォトクロミック性を示すケイ酸塩化合物によって、Ｘ線の照射と加熱で、繰り返して着脱色させることが可能となる。また、無機材料で構成されるものとなり、化学的及び熱的に安定な構造となる。更に、有機物のように溶媒に溶かす必要がなく、固体での利用が可能となる。 Here, the silicate compound exhibiting photochromic properties can be repeatedly attached and detached by X-ray irradiation and heating. In addition, it is composed of an inorganic material and has a chemically and thermally stable structure. Furthermore, it is not necessary to dissolve in a solvent as in the case of organic substances, and it can be used as a solid.
　また、粉状体を１１５０℃～１３００℃で焼成することによって、フォトクロミック性を示す結晶相を充分に形成させることが可能となる。 Further, by firing the powdery body at 1150 ° C. to 1300 ° C., a crystal phase exhibiting photochromic properties can be sufficiently formed.
　ここで、粉状体を１１５０℃未満の温度で焼成すると、目的の結晶相が形成されない、もしくは不充分にしか形成されないおそれがある。一方、粉状体を、１３００℃を超える温度で焼成すると、目的の結晶相が形成されないことや、材料の溶融が生じてしまう。 Here, if the powdery body is fired at a temperature lower than 1150 ° C., the target crystal phase may not be formed or may be formed only insufficiently. On the other hand, when the powdery body is fired at a temperature exceeding 1300 ° C., the target crystal phase is not formed or the material is melted.
　また、粉状体を還元雰囲気下で焼成することによって、焼成物の結晶構造中に、フォトクロミズムの機能性を生じる格子欠陥が形成されやすいものとなる。 Further, by firing the powdery body in a reducing atmosphere, lattice defects that cause photochromic functionality are easily formed in the crystal structure of the fired product.
　また、粉状体を２時間以上焼成することによって、フォトクロミック性を示す結晶相を充分に成長させることが可能となる。なお、焼成時間が２時間未満である場合には、充分な粒成長と化学反応が達成されず、目的の結晶相及び機能が得にくくなってしまう。 Further, by firing the powdery body for 2 hours or more, it is possible to sufficiently grow a crystal phase exhibiting photochromic properties. When the firing time is less than 2 hours, sufficient grain growth and chemical reaction are not achieved, and it becomes difficult to obtain the target crystal phase and function.
　また、上記の目的を達成するために、本発明のＸ線記録媒体は、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料が均一に配合された記録層を有すると共に、書き換え可能に構成されている。 In order to achieve the above object, the X-ray recording medium of the present invention has a recording layer in which an X-ray recording material containing a silicate compound exhibiting photochromic properties is uniformly blended and is rewritable. It is configured.
　ここで、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料が均一に配合された記録層を有することによって、Ｘ線を照射して得られた画像を記録することが可能となる。即ち、例えば、Ｘ線の生成源と、記録層との間に対象物を配置し、Ｘ線を照射することで、対象物内部の透過Ｘ線画像が得られるものとなる。 Here, an image obtained by irradiating X-rays can be recorded by having a recording layer in which an X-ray recording material containing a silicate compound exhibiting photochromic properties is uniformly blended. That is, for example, an object is placed between an X-ray generation source and a recording layer and irradiated with X-rays, whereby a transmitted X-ray image inside the object can be obtained.
　また、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料が配合され、書き換え可能に構成されたことによって、着色で得られたＸ線画像を消して、繰り返し使用することができる。 Further, the X-ray recording material containing a photosilicate silicate compound is blended and rewritable, so that the X-ray image obtained by coloring can be erased and used repeatedly.
　また、Ｘ線の照射で蛍光を発すると共に、その発光スペクトルの波長範囲の少なくとも一部が、ケイ酸化合物が示す吸光度スペクトルの波長範囲と重複するシンチレータを含有する場合には、Ｘ線に対する感度をより一層向上させることが可能となる。即ち、Ｘ線が照射されたシンチレータが一定波長の光を生じ、その発光をケイ酸化合物が吸収して、着色に有利に働くものとなる。 In addition, when the X-ray irradiation fluoresces and at least part of the wavelength range of the emission spectrum contains a scintillator that overlaps the wavelength range of the absorbance spectrum exhibited by the silicate compound, the sensitivity to X-rays is increased. This can be further improved. That is, the scintillator irradiated with X-rays generates light of a certain wavelength, and the silicate compound absorbs the emitted light, which works favorably for coloring.
　また、上記の目的を達成するために、本発明のＸ線記録媒体による記録方法は、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料であり、加熱して脱色可能に構成されたＸ線記録媒体に波長０．００１～１０ｎｍの範囲のＸ線を照射して着色する。 In order to achieve the above object, the recording method using the X-ray recording medium of the present invention is an X-ray recording material containing a silicate compound exhibiting photochromic properties, and is configured to be decolored by heating. The X-ray recording medium is colored by irradiation with X-rays having a wavelength in the range of 0.001 to 10 nm.
　ここで、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料で構成されたＸ線記録媒体に波長０．００１～１０ｎｍの範囲のＸ線を照射して着色することによって、Ｘ線の照射で記録材料を着色させ、Ｘ線画像の取得及び記録を行うことができる。また、無機材料で構成されるものとなり、化学的及び熱的に安定した記録が可能となる。 Here, an X-ray recording medium composed of an X-ray recording material containing a silicate compound exhibiting photochromic properties is irradiated with X-rays in the wavelength range of 0.001 to 10 nm to color the X-rays. The recording material can be colored by irradiation to obtain and record an X-ray image. Further, the recording medium is composed of an inorganic material, and chemical and thermal stable recording is possible.
　また、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料であり、加熱して脱色可能に構成されたＸ線記録媒体によって、記録材料に記録したＸ線画像を消去でき、繰り返しの記録が可能な方法となる。 Further, an X-ray recording material containing a silicate compound exhibiting photochromic properties, and an X-ray image recorded on the recording material can be erased by an X-ray recording medium configured to be decolored by heating, and repeated recording Is a possible method.
　また、上記の目的を達成するために、本発明のＸ線照射量の測定方法は、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料から構成されたＸ線記録媒体に波長０．００１～１０ｎｍの範囲のＸ線を照射して着色する着色工程と、前記着色工程で得られた前記Ｘ線記録材料の着色量からＸ線照射量を検出する検出工程とを備える。 In order to achieve the above object, the X-ray irradiation measuring method of the present invention is applied to an X-ray recording medium comprising an X-ray recording material containing a silicate compound exhibiting photochromic properties at a wavelength of 0. A coloring step of irradiating and coloring with X-rays in the range of 001 to 10 nm; and a detecting step of detecting the X-ray irradiation amount from the coloring amount of the X-ray recording material obtained in the coloring step.
　ここで、フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料から構成されたＸ線記録媒体に波長０．００１～１０ｎｍの範囲のＸ線を照射して着色する着色工程によって、Ｘ線の照射で記録材料を着色させて、検出対象のＸ線照射量を算出するための着色量の情報を得ることができる。 Here, the X-ray recording medium composed of an X-ray recording material containing a silicate compound exhibiting photochromic properties is irradiated with X-rays having a wavelength in the range of 0.001 to 10 nm to color the X-rays. The recording material can be colored by this irradiation, and information on the coloring amount for calculating the X-ray irradiation amount to be detected can be obtained.
　また、着色工程で得られたＸ線記録材料の着色量からＸ線照射量を検出する検出工程によって、検出対象の簡易的なＸ線照射量を測定可能となる。より詳細には、あらかじめ、Ｘ線記録材料におけるＸ線照射量と着色量との間の検量線を作成しておき、記録材料に記録された着色量と検量線から、対象のＸ線照射量を決めることができる。 Also, a simple X-ray irradiation amount to be detected can be measured by a detection step of detecting the X-ray irradiation amount from the coloring amount of the X-ray recording material obtained in the coloring step. More specifically, a calibration curve between the X-ray irradiation amount and the coloring amount in the X-ray recording material is prepared in advance, and the target X-ray irradiation amount is calculated from the coloring amount and the calibration curve recorded in the recording material. Can be decided.
　本発明に係るＸ線記録材料は、繰り返し使用可能かつ耐久性を有し、実用性に優れたものとなっている。
　また、本発明に係るＸ線記録材料の製造方法は、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線記録材料を製造可能なものとなっている。
　また、本発明に係るＸ線記録媒体は、繰り返し使用可能かつ耐久性を有し、実用性に優れたものとなっている。
　また、本発明に係るＸ線記録媒体の製造方法は、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線記録媒体を製造可能なものとなっている。
　更に、本発明に係るＸ線照射量の測定方法は、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線照射量の測定方法を提供するものとなっている。 The X-ray recording material according to the present invention is reusable and durable, and has excellent practicality.
In addition, the method for producing an X-ray recording material according to the present invention is capable of producing an X-ray recording material that can be used repeatedly, has durability, and has excellent practicality.
The X-ray recording medium according to the present invention is reusable and durable, and has excellent practicality.
In addition, the method for producing an X-ray recording medium according to the present invention can produce an X-ray recording medium that can be used repeatedly, has durability, and is highly practical.
Furthermore, the method for measuring an X-ray irradiation amount according to the present invention provides a method for measuring an X-ray irradiation amount that can be used repeatedly, has durability, and has excellent practicality.
Ｘ線透過画像を得るための装置構成の一例を示す概略図（ａ）及び画像取得の状況を示す概略図（ｂ）である。It is the schematic (a) which shows an example of an apparatus structure for obtaining an X-ray transmission image, and the schematic (b) which shows the condition of image acquisition. Ｘ線照射による着色後及び加熱による脱色後の実施例１の吸収スペクトルである。It is an absorption spectrum of Example 1 after coloring by X-ray irradiation and after decoloring by heating. 着色及び脱色を繰り返した実施例１における波長５２０ｎｍのピーク強度を示すグラフである。It is a graph which shows the peak intensity of wavelength 520nm in Example 1 which repeated coloring and decoloring. Ｘ線の出力を変えて照射した際の実施例１における照射時間と波長５２０ｎｍの吸光度の関係を示すグラフである。It is a graph which shows the relationship between the irradiation time in Example 1 at the time of irradiating by changing the output of X-ray | X_line, and the light absorbency of wavelength 520nm. 実施例２～４の着色後の経過時間と波長５２０ｎｍにおける吸光度の関係を示すグラフである。6 is a graph showing the relationship between the elapsed time after coloring in Examples 2 to 4 and the absorbance at a wavelength of 520 nm. 図５に示す結果を常用対数で表示したグラフである。It is the graph which displayed the result shown in FIG. 5 by common logarithm. 実施例２～８の着色後の吸収スペクトルである。6 is an absorption spectrum after coloring in Examples 2 to 8.
　以下、本発明の実施の形態について詳細を説明し、本発明の理解に供する。 Hereinafter, embodiments of the present invention will be described in detail to provide an understanding of the present invention.
　（フォトクロミック材料）
　本発明のＸ線記録材料であるフォトクロミック材料は、下記式（ａ）
　Ｂａ（Ｍｇ１－ｘ－ｙＦｅｘＡｌｙ）（Ｓｉ１－ｚＢｚ）Ｏ４・・・（ａ）
（式中、０≦ｘ＜０．０１、０≦ｙ＜０．１０、０≦ｚ＜０．２０である。）
で表される組成を有している。本物質は、ＳｉＯ４－ＭｇＯ４ネットワーク構造の骨格を有するバリウムマグネシウムケイ酸塩を基礎とする。 (Photochromic material)
The photochromic material that is the X-ray recording material of the present invention has the following formula (a):
Ba (Mg 1-x-y Fe x Al y) (Si 1-z B z) O 4 ··· (a)
(In the formula, 0 ≦ x <0.01, 0 ≦ y <0.10, and 0 ≦ z <0.20.)
It has the composition represented by these. This material is based on barium magnesium silicate with a skeleton of SiO 4 —MgO 4 network structure.
　本物質は、そのＳｉＯ４四面体におけるケイ素イオン（Ｓｉ４＋）は一定の割合でマグネシウムイオン（Ｍｇ２＋）に置き換わっている。また、マグネシウムイオン（Ｍｇ２＋）は、鉄イオン（Ｆｅ２＋）及びアルミニウムイオン（Ａｌ３＋）が結合するサイトとなる。更に、ケイ素イオン（Ｓｉ４＋）はホウ素イオン（Ｂ３＋）が結合するサイトとなる。 In this substance, silicon ions (Si 4+ ) in the SiO 4 tetrahedron are replaced with magnesium ions (Mg 2+ ) at a certain ratio. Magnesium ions (Mg 2+ ) are sites where iron ions (Fe 2+ ) and aluminum ions (Al 3+ ) are bonded. Further, silicon ions (Si 4+ ) are sites to which boron ions (B 3+ ) are bonded.
　上記式（ａ）で示す組成を有することにより、本物質は波長０．００１ｎｍ～１０ｎｍの範囲のＸ線の照射に対して赤紫色に着色するフォトクロミズム性を示す。なお、本物質は、Ｘ線の照射だけでなく、紫外線の照射によっても着色するものである。 By having the composition represented by the above formula (a), the substance exhibits a photochromism property of being colored purplish to X-ray irradiation in a wavelength range of 0.001 nm to 10 nm. The substance is colored not only by X-ray irradiation but also by ultraviolet irradiation.
　また、無機材料で構成されることから、化学的及び熱的に安定な構造となり、高い耐久性を有するものとなる。更に、有機物のように溶媒に溶かす必要がなく、固体のまま利用することができる。 Also, since it is made of an inorganic material, it has a chemically and thermally stable structure and has high durability. Furthermore, it is not necessary to dissolve in a solvent like an organic substance, and it can be used as a solid.
　本物質は、Ｘ線の照射による着色した状態での耐熱性が高く、例えば、１００℃程度まで変色の状態を保持しうる。また、着色した状態を長期間、例えば、数百日間は保持し得るものとなっている。 This material has high heat resistance in a colored state by X-ray irradiation, and can maintain a discolored state up to, for example, about 100 ° C. Further, the colored state can be maintained for a long time, for example, several hundred days.
　また、Ｘ線の照射により着色した本物質に対して、緑色光（例えば、波長５３２ｎｍ）の照射や加熱を行うことで、再度、元の色へと脱色することができる。このため、Ｘ線記録材料が繰り返し使用可能となる。更に、本物質において着色及び脱色を繰り返しても、充分な着色強度が得られ、劣化しにくいものとなっている。なお、この点は後述の実施例において詳細を説明する。 In addition, the original material colored by X-ray irradiation can be decolorized again by irradiating it with green light (for example, wavelength 532 nm) or heating. For this reason, the X-ray recording material can be used repeatedly. Furthermore, even if coloring and decoloring are repeated in this substance, sufficient coloring strength is obtained and it is difficult to deteriorate. This point will be described in detail in the embodiments described later.
　上記式（ａ）におけるｘは０≦ｘ＜０．０１の範囲内であることが好ましい。また、ｙは０≦ｙ＜０．１０の範囲内であることが好ましい。式（ａ）における範囲内であれば、Ｘ線記録材料のフォトクロミズム特性を良好なものとすることができる。 X in the above formula (a) is preferably in the range of 0 ≦ x <0.01. Further, y is preferably in the range of 0 ≦ y <0.10. Within the range in the formula (a), the photochromism characteristics of the X-ray recording material can be improved.
　より詳細には、上記の範囲内でＭｇがＦｅまたはＡｌに置換されると、Ｘ記録材料のＸ線への感度及び着色強度が向上する。また、Ｘ線照射後の着色状態の保持時間が伸長する。 More specifically, when Mg is substituted with Fe or Al within the above range, the sensitivity to X-rays and the coloring strength of the X recording material are improved. Moreover, the retention time of the colored state after X-ray irradiation is extended.
　上記式（ａ）におけるｚは０≦ｚ＜０．２０の範囲内であることが好ましい。式（ａ）における範囲内であれば、Ｘ線記録材料のフォトクロミズム特性を良好なものとすることができる。 Z in the above formula (a) is preferably in the range of 0 ≦ z <0.20. Within the range in the formula (a), the photochromism characteristics of the X-ray recording material can be improved.
　より詳細には、上記の範囲内でＳｉがＢに置換されると、着色強度が向上するものとなる。 More specifically, when Si is replaced with B within the above range, the coloring strength is improved.
　また、本物質では、ＢａＭｇＳｉＯ４相の最も強いＸ線のピーク強度が、他の結晶層によるＸ線のピーク強度に対して２倍以上であることが好ましい。 Moreover, in this substance, it is preferable that the strongest X-ray peak intensity of the BaMgSiO 4 phase is twice or more the X-ray peak intensity of the other crystal layers.
　上記式（ａ）で示される組成としては、Ｂａ（Ｍｇ１－ｘ－ｙＦｅｘＡｌｙ）（Ｓｉ１－ｚＢｚ）Ｏ４、ＢａＭｇ（Ｓｉ１－ｚＢｚ）Ｏ４、Ｂａ（Ｍｇ１－ｙＡｌｙ）（Ｓｉ１－ｚＢｚ）Ｏ４、Ｂａ（Ｍｇ１－ｘＦｅｘ）ＳｉＯ４、ＢａＭｇＳｉＯ４、Ｂａ（Ｍｇ１－ｙＡｌｙ）ＳｉＯ４の構成が挙げられる。 The composition represented by the above formula (a), Ba (Mg 1 -x-y Fe x Al y) (Si 1-z Bz) O 4, BaMg (Si 1-z Bz) O 4, Ba (Mg 1 -y Al y) (Si 1- z Bz) O 4, Ba (Mg 1-x Fe x) SiO 4, BaMgSiO 4, structure of Ba (Mg 1-y Al y ) SiO 4 and the like.
　上記式（ａ）で示す組成の各原料として、例えば、Ｂａ元素を含む原料は、炭酸バリウム、硫酸バリウム、酸化バリウム、硝酸バリウム、水酸化バリウム、ケイ化バリウム、ホウ酸バリウムが挙げられる。また、Ｍｇ元素を含む原料は、炭酸マグネシウム、酸化マグネシウムが挙げられる。Ｓｉ元素を含む原料は、シリコン、酸化シリコンが挙げられる。 As each raw material having the composition represented by the above formula (a), for example, the raw material containing Ba element includes barium carbonate, barium sulfate, barium oxide, barium nitrate, barium hydroxide, barium silicide, and barium borate. Examples of the raw material containing Mg element include magnesium carbonate and magnesium oxide. Examples of the raw material containing Si element include silicon and silicon oxide.
　更に、Ｏ元素を含む原料は、上述した各種酸化物が挙げられる。また、Ｆｅ元素を含む原料は、各酸化数の酸化鉄等が挙げられる。Ａｌを含む原料としては、酸化アルミニウム、酢酸アルミニウム等が挙げられる。なお、フォトクロミック材料の混合物には、上記各原料以外にも、フォトクロミズムを阻害しない範囲で、他の物質等を更に含有していてもよい。 Furthermore, examples of the raw material containing the O element include the various oxides described above. Examples of the raw material containing Fe element include iron oxides having various oxidation numbers. Examples of the raw material containing Al include aluminum oxide and aluminum acetate. The mixture of photochromic materials may further contain other substances in addition to the above raw materials as long as the photochromism is not inhibited.
　本発明のＸ線記録材料では、フォトクロミック材料に加えて、シンチレータを含有させることもできる。シンチレータとは、Ｘ線の照射に対して任意の波長を発する蛍光体である。 The X-ray recording material of the present invention may contain a scintillator in addition to the photochromic material. A scintillator is a phosphor that emits an arbitrary wavelength in response to X-ray irradiation.
　上記式（ａ）で示すフォトクロミック材料は２５０ｎｍの波長を有する光に対して最大の感度を有しており、この感度はＸ線の照射に対する感度よりも大きなものとなっている。 The photochromic material represented by the above formula (a) has the greatest sensitivity to light having a wavelength of 250 nm, and this sensitivity is greater than the sensitivity to X-ray irradiation.
　そのため、Ｘ線の照射により２５０ｎｍを含む波長帯の蛍光を発するシンチレータをフォトクロミック材料と共に用いることで、Ｘ線の照射に対するＸ線記録材料の感度を向上させることができる。 Therefore, the sensitivity of the X-ray recording material to X-ray irradiation can be improved by using a scintillator that emits fluorescence in a wavelength band including 250 nm together with the photochromic material by X-ray irradiation.
　即ち、フォトクロミック材料の吸光度スペクトルと、シンチレータのＸ線照射に対する発光スペクトルにおいて、各スペクトルが重なる範囲を有し、かつ、重なりが大きくなるシンチレータを選択することで、Ｘ記録材料のＸ線への感度に対して有利に働くものとなる。 That is, in the absorbance spectrum of the photochromic material and the emission spectrum with respect to the X-ray irradiation of the scintillator, by selecting a scintillator in which the spectra overlap and the overlap is large, the sensitivity of the X recording material to X-rays is selected. It will work in favor of.
　上記式（ａ）で示すフォトクロミック材料と併用するシンチレータとしては、例えば、純ヨウ化セシウム（ＣｓＩ：発光ピーク波長３１５ｎｍ）や、フッ化バリウム（ＢａＦ２：発光ピーク波長２１０ｎｍ、３１０ｎｍ）が挙げられる。なお、シンチレータの種類はこれに限定されるものではなく、Ｘ線への感度を向上できるものであれば、適宜選択しうる。 Examples of the scintillator used in combination with the photochromic material represented by the above formula (a) include pure cesium iodide (CsI: emission peak wavelength 315 nm) and barium fluoride (BaF 2 : emission peak wavelengths 210 nm, 310 nm). Note that the type of scintillator is not limited to this, and can be appropriately selected as long as the sensitivity to X-rays can be improved.
　（Ｘ線記録材料の製造方法）
　本発明のＸ線記録材料は、上記式（ａ）で示す組成を有するフォトクロミック材料を含む粉状体を１１５０℃～１３００℃の還元雰囲気下で２時間以上焼成して製造される。 (Method for producing X-ray recording material)
The X-ray recording material of the present invention is produced by firing a powdery material containing a photochromic material having the composition represented by the above formula (a) in a reducing atmosphere at 1150 ° C. to 1300 ° C. for 2 hours or more.
　前述したフォトクロミック材料の粉状体を還元雰囲気下で焼成することで、焼成物の結晶構造中に格子欠陥が生じ、フォトクロミズム性に寄与すると推測されている。 It is presumed that by firing the above-described photochromic material powder in a reducing atmosphere, lattice defects are generated in the crystal structure of the fired product and contribute to photochromism.
　焼成する工程においては、例えば、ホウ酸をフォトクロミック材料に添加することで、還元雰囲気下で処理可能となる。添加するホウ酸の含有量は特に限定されるものではないが、上記式（ａ）で示すフォトクロミック材料におけるＢａを含む原料に含まれる当該Ｂａに対して、２～１０モル％の範囲内となる量であることが好ましい。 In the firing step, for example, by adding boric acid to the photochromic material, it can be processed in a reducing atmosphere. The content of boric acid to be added is not particularly limited, but is in the range of 2 to 10 mol% with respect to the Ba contained in the raw material containing Ba in the photochromic material represented by the above formula (a). An amount is preferred.
　また、上記式（ａ）で示すフォトクロミック材料には、各原料及びホウ酸がより均一に混合されるように、エチルアルコール等の溶媒が更に混合されていてもよい。なお、各原料、ホウ酸および溶媒等の混合方法は、均一な混合物が得られる方法であれば充分であり、混合方法の種類が特に限定されるものではない。 Also, the photochromic material represented by the above formula (a) may be further mixed with a solvent such as ethyl alcohol so that each raw material and boric acid are more uniformly mixed. In addition, the mixing method of each raw material, boric acid, a solvent, etc. is sufficient if it is a method by which a uniform mixture is obtained, and the kind of mixing method is not specifically limited.
　フォトクロミック材料を含む粉状体を焼成する工程は、還元雰囲気下で行うことがより好ましく、水素ガス存在下で行うことがさらに好ましい。具体的な焼成方法としては、例えば、アルゴンガス等の不活性ガスと、水素ガス等の還元性ガスとの混合ガス気流中で混合物の焼成を行う方法が挙げられる。 The step of firing the powdery body containing the photochromic material is more preferably performed in a reducing atmosphere, and more preferably in the presence of hydrogen gas. Specific examples of the firing method include a method of firing the mixture in a mixed gas stream of an inert gas such as argon gas and a reducing gas such as hydrogen gas.
　混合ガスにおける水素ガスの濃度は、２～１０体積％の範囲内であることが好ましい。また、焼成条件としては、１１５０℃～１３００℃で２時間焼成する条件が挙げられる。本条件で焼成処理を行うことで、フォトクロミック性を示す結晶相が充分に形成された焼成物とすることができる。また、焼成装置は市販の装置を用いることができる。 The concentration of hydrogen gas in the mixed gas is preferably in the range of 2 to 10% by volume. Examples of the firing conditions include conditions of firing at 1150 ° C. to 1300 ° C. for 2 hours. By performing the firing treatment under these conditions, a fired product in which a crystal phase exhibiting photochromic properties is sufficiently formed can be obtained. A commercially available apparatus can be used as the baking apparatus.
　ここで、必ずしも、焼成条件が１１５０℃～１３００℃の温度範囲に限定される必要はない。但し、上記式（ａ）で示すフォトクロミック材料において、材料が溶融しにくく、フォトクロミック性を示す結晶相を充分に形成できる点から、焼成条件が１１５０℃～１３００℃の温度範囲とされることが好ましい。 Here, the firing conditions are not necessarily limited to the temperature range of 1150 ° C to 1300 ° C. However, in the photochromic material represented by the above formula (a), it is preferable that the firing condition is in a temperature range of 1150 ° C. to 1300 ° C. from the viewpoint that the material is difficult to melt and a crystal phase exhibiting photochromic properties can be sufficiently formed. .
　また、必ずしも、焼成条件が１１５０℃～１３００℃で２時間焼成する条件に限定される必要はない。但し、原料や中間生成物の不純物の含有量を減らし、フォトクロミック性を示す結晶相を充分に形成できる点から、焼成条件が１１５０℃～１３００℃で２時間焼成する条件であることが好ましい。 Also, the firing condition is not necessarily limited to the condition of firing at 1150 ° C. to 1300 ° C. for 2 hours. However, from the viewpoint that the content of impurities in the raw materials and intermediate products can be reduced and a crystal phase exhibiting photochromic properties can be sufficiently formed, the firing conditions are preferably those for firing at 1150 ° C. to 1300 ° C. for 2 hours.
　Ｘ線記録材料は、板状等の一定形状となるように形成した粉状体の焼成物をそのまま利用することができる。この場合、焼成後の形状は特に限定されるものではなく、Ｘ線透過画像を得たい対象物の大きさや形状に合わせて適宜選択しうる。 As the X-ray recording material, a fired product of a powdery body formed so as to have a certain shape such as a plate shape can be used as it is. In this case, the shape after firing is not particularly limited, and can be appropriately selected according to the size and shape of an object for which an X-ray transmission image is desired.
　また、Ｘ線記録材料は、任意の素材の基板上にフォトクロミック材料を含む液状成分を塗膜して、基板上に記録層を設ける構造とすることもできる。基板上に記録層を設ける場合には、例えば、ビヒクルに適量の上述したフォトクロミック材料を分散させ、ドクターブレード法等の既知の薄膜形成法によって、基板上に均一圧膜を形成する。 Also, the X-ray recording material can be structured such that a liquid component containing a photochromic material is coated on a substrate of an arbitrary material and a recording layer is provided on the substrate. When the recording layer is provided on the substrate, for example, an appropriate amount of the above-described photochromic material is dispersed in a vehicle, and a uniform pressure film is formed on the substrate by a known thin film forming method such as a doctor blade method.
　ここで、記録層を形成する基板の素材は特に限定されるものではなく、ガラス、樹脂、金属等、Ｘ線記録材料の用途に応じて適宜選択しうるものである。 Here, the material of the substrate on which the recording layer is formed is not particularly limited, and may be appropriately selected according to the use of the X-ray recording material, such as glass, resin, metal and the like.
　このように、Ｘ線記録材料は、基板上に記録層を形成する構造とすることもできる。 As described above, the X-ray recording material may have a structure in which a recording layer is formed on a substrate.
　以上で説明したフォトクロミック材料及びＸ線記録媒体の製造方法により、本発明を適用したＸ線記録媒体を製造しうるものとなっている。 The X-ray recording medium to which the present invention is applied can be manufactured by the photochromic material and the X-ray recording medium manufacturing method described above.
　以下、本発明の実施例を説明する。 Hereinafter, examples of the present invention will be described.
　（１）実施例１
　上述した内容のフォトクロミック材料及び製造方法を用いて実施例１の試料を作製した。実施例１では、フォトクロミック材料Ｂａ（Ｍｇ１－ｘ－ｙＦｅｘＡｌｙ）（Ｓｉ１－ｚＢｚ）Ｏ４の組成を有する粉状体を原料とした。この粉状体を円形に成型後、還元雰囲気下にて焼成した。１１５０℃～１３００℃の温度範囲で２時間の焼成処理を行った。焼成物は平板かつ円形の外周を有する錠剤型の形状となり、これをＸ線記録媒体として用いて、以下の確認を行った。 (1) Example 1
A sample of Example 1 was prepared using the photochromic material and manufacturing method described above. In Example 1, a powdery material having a composition of the photochromic material Ba (Mg 1-xy Fe x Al y ) (Si 1-z Bz) O 4 was used as a raw material. The powdery body was molded into a circle and then fired in a reducing atmosphere. The baking treatment was performed for 2 hours in the temperature range of 1150 ° C to 1300 ° C. The fired product was in the form of a tablet having a flat and circular outer periphery, and the following confirmation was performed using this as an X-ray recording medium.
　（２）Ｘ線記録のための装置構成 (2) Device configuration for X-ray recording
　対象物のＸ線透過画像を得るための装置構成を図１に示す。図１（ａ）に示すように、装置構成１では、Ｘ線源２、スリット３、及び実施例１であるフォトクロミック性を示すＸ線記録ペレット４を有している。Ｘ線源２として、Ｃｕをターゲットとする封入管Ｘ線発生装置を用いた。 Fig. 1 shows an apparatus configuration for obtaining an X-ray transmission image of an object. As shown in FIG. 1A, the apparatus configuration 1 has an X-ray source 2, a slit 3, and an X-ray recording pellet 4 showing photochromic properties that is Example 1. As the X-ray source 2, a sealed tube X-ray generator using Cu as a target was used.
　Ｘ線記録ペレット４の前面の位置５にＸ線を照射する対象物を配置した。また、図１（ａ）に右下の図には、Ｘ線記録ペレット４の面上におけるＸ線の照射エリア６及び紫外可視分光法の測定エリア７を示している。 An object to be irradiated with X-rays was placed at position 5 on the front surface of the X-ray recording pellet 4. 1A shows an X-ray irradiation area 6 and an ultraviolet-visible spectroscopy measurement area 7 on the surface of the X-ray recording pellet 4.
　装置構成１では、図１（ｂ）に示すように、Ｘ線源２から照射されるＸ線（符号Ｘ）を、Ｘ線透過画像を得たい対象物８に照射する。対象物８を透過したＸ線は、その一部が対象物８の内部で吸収され、強度分布を有するＸ線がＸ線記録ペレット４に照射される。その結果、Ｘ線の照射でＸ線記録ペレット４が赤紫色に着色し、透過画像９が得られるものとなる。 In the apparatus configuration 1, as shown in FIG. 1B, X-rays (symbol X) irradiated from the X-ray source 2 are irradiated to an object 8 for which an X-ray transmission image is to be obtained. Part of the X-rays transmitted through the object 8 is absorbed inside the object 8, and X-rays having an intensity distribution are irradiated to the X-ray recording pellet 4. As a result, the X-ray recording pellet 4 is colored reddish purple by X-ray irradiation, and a transmission image 9 is obtained.
　（３）Ｘ線の照射と加熱後の吸収スペクトル
　まず、上記の装置構成１で、対象物８を配置せずに、Ｘ線記録ペレット４にＸ線の照射を行った。出力４０ｋＶ、２０ｍＡの条件下、２時間のＸ線照射を行った。また、Ｘ線照射後のＸ線記録ペレット４を、２５０℃に加熱した電気炉に１０分間放置した。この際のＸ線照射後のＸ線記録ペレット４と、加熱後のＸ線記録ペレット４について、ＵＶ－ＶＩＳ－ＮＩＲ分光光度計で吸収スペクトルを確認した。図２に吸収スペクトルを示している。 (3) X-ray irradiation and absorption spectrum after heating First, in the apparatus configuration 1 described above, the X-ray recording pellet 4 was irradiated with X-rays without arranging the object 8. X-ray irradiation was performed for 2 hours under conditions of an output of 40 kV and 20 mA. Further, the X-ray recording pellet 4 after X-ray irradiation was left in an electric furnace heated to 250 ° C. for 10 minutes. The absorption spectra of the X-ray recording pellet 4 after X-ray irradiation and the X-ray recording pellet 4 after heating were confirmed with a UV-VIS-NIR spectrophotometer. FIG. 2 shows an absorption spectrum.
　図２に示すように、Ｘ線照射後の試料は、波長５２０ｎｍの位置にピークを有する吸収スペクトル（符号１０）となり、着色前の白色の状態から、赤紫色に着色することが確認された。また、加熱後の試料は、波長５２０ｎｍのピークが消失した吸収スペクトル（符号１１）となり、赤紫色が脱色され元の白色となっていることが確認された。このように、実施例１の試料は、Ｘ線で着色され、加熱により脱色されるフォトクロミズム性を示すものであった。また、着色と脱色による繰り返しの使用が可能である点が明らかとなった。 As shown in FIG. 2, the sample after X-ray irradiation had an absorption spectrum (reference numeral 10) having a peak at a wavelength of 520 nm, and it was confirmed that the sample was colored reddish purple from the white state before coloring. Moreover, the sample after heating became an absorption spectrum (symbol 11) in which the peak at a wavelength of 520 nm disappeared, and it was confirmed that the reddish purple color was decolored to be the original white color. As described above, the sample of Example 1 was colored with X-rays and exhibited photochromism that was decolorized by heating. Moreover, it became clear that it can be used repeatedly by coloring and decoloring.
　（４）Ｘ線透過画像の取得
　続いて、上述した装置構成１において、市販のＵＳＢフラッシュドライブ（ＵＳＢメモリ）を対象物８としてＸ線照射を行った。出力４０ｋＶ、３０ｍＡの条件下、３時間のＸ線照射を行った。この結果、ＵＳＢフラッシュドライブの内部素子構造を反映したＸ線透過画像を確認することができた。なお、参考までにＵＳＢフラッシュドライブとそのＸ線照射エリアを参考図１に、得られたＸ線透過画像を参考図２に掲載する。 (4) Acquisition of X-ray transmission image Subsequently, in the apparatus configuration 1 described above, X-ray irradiation was performed using a commercially available USB flash drive (USB memory) as an object 8. X-ray irradiation was performed for 3 hours under conditions of an output of 40 kV and 30 mA. As a result, an X-ray transmission image reflecting the internal element structure of the USB flash drive could be confirmed. For reference, the USB flash drive and its X-ray irradiation area are shown in Reference FIG. 1, and the obtained X-ray transmission image is shown in Reference FIG.
　（５）繰り返し記録による耐久性の確認
　上述した（４）と同様の条件で、Ｘ線の照射及び加熱による脱色のプロセスを２００回以上行い、フォトクロミズム特性の劣化の有無を調べた。具体的には、波長５２０ｎｍのピーク強度をＸ線照射後及び加熱後に測定した。図３に、ピーク強度のモニタリング結果を示す。なお、図３は横軸が測定回数、縦軸が波長５２０ｎｍのピーク強度を表している。 (5) Confirmation of durability by repeated recording Under the same conditions as in (4) above, the process of decolorization by X-ray irradiation and heating was performed 200 times or more, and the presence or absence of deterioration of photochromism characteristics was examined. Specifically, the peak intensity at a wavelength of 520 nm was measured after X-ray irradiation and after heating. FIG. 3 shows the monitoring results of peak intensity. In FIG. 3, the horizontal axis represents the number of measurements, and the vertical axis represents the peak intensity at a wavelength of 520 nm.
　図３に示すように、実施例１のＸ線記録媒体は、２０回の測定時点においても波長５２０ｎｍのピーク強度に低下は見られなかった。また、図３には示していないが、この後、２００回以上の測定においても、計測初期と同程度のピーク強度を維持していた。即ち、実施例１のＸ線記録媒体は、繰り返して使用した場合にも、Ｘ線に対する充分な感度を有し、再現性のあるＸ線透過画像を取得可能な耐久性を有するものであることが明らかとなった。 As shown in FIG. 3, the X-ray recording medium of Example 1 did not show a decrease in the peak intensity at a wavelength of 520 nm even at 20 measurement points. Further, although not shown in FIG. 3, the peak intensity at the same level as the initial measurement was maintained even after the 200th measurement. That is, the X-ray recording medium of Example 1 has sufficient sensitivity to X-rays even when it is used repeatedly, and has durability capable of acquiring a reproducible X-ray transmission image. Became clear.
　（６）Ｘ線出力と照射時間
　実施例１のＸ線記録媒体に対して、異なる出力のＸ線を照射して、各照射時間における波長５２０ｎｍの吸光度をモニタリングした。なお、Ｘ線の出力は、４０ｋＶで３０ｍＡ（符号１２）、２０ｍＡ（符号１３）、１０ｍＡ（符号１４）の三段階とした。図４に、波長５２０ｎｍの吸光度のモニタリング結果を示す。また、図４の右下には、図４の左側のグラフを対数表示したグラフを示している。 (6) X-ray output and irradiation time The X-ray recording medium of Example 1 was irradiated with X-rays having different outputs, and the absorbance at a wavelength of 520 nm was monitored at each irradiation time. The output of X-rays was set at three stages of 30 mA (reference numeral 12), 20 mA (reference numeral 13), and 10 mA (reference numeral 14) at 40 kV. FIG. 4 shows the results of monitoring absorbance at a wavelength of 520 nm. Further, the lower right of FIG. 4 shows a logarithmic display of the left graph of FIG.
　図４から明らかなように、各出力において照射時間１５００秒で波長５２０ｎｍにおける吸光度の上昇が見られた。また、各出力において照射時間３５００秒以降で波長５２０ｎｍにおける吸光度がほぼ上昇しない飽和状態となった。この結果から、Ｘ線の出力が４０ｋＶ、１０ｍＡ以上であれば、Ｘ線の照射を２５分程度行えば、着色が充分に確認できるものであることが分かった。 As is clear from FIG. 4, an increase in absorbance at a wavelength of 520 nm was observed at an irradiation time of 1500 seconds at each output. Moreover, in each output, it became a saturated state in which the absorbance at a wavelength of 520 nm hardly increased after an irradiation time of 3500 seconds. From this result, it was found that if the X-ray output is 40 kV and 10 mA or more, the coloration can be sufficiently confirmed if the X-ray irradiation is performed for about 25 minutes.
　また、上述した（６）に関連して、Ｘ線記録媒体を用いて、簡易なＸ線照射量の検出を行うことが可能である。具体的には、Ｘ線記録媒体のＸ線照射量と着色量における検量線を作成することで、着色量からＸ線照射量を簡易的に定量することができる。このように、本発明のＸ線記録媒体は、Ｘ線透過画像の記録だけでなく、計測方法としての用途が考えられるものである。 Further, in relation to the above (6), it is possible to easily detect the X-ray irradiation dose using the X-ray recording medium. Specifically, the X-ray irradiation dose can be easily quantified from the coloring amount by creating a calibration curve for the X-ray irradiation amount and the coloring amount of the X-ray recording medium. As described above, the X-ray recording medium of the present invention can be used not only for recording X-ray transmission images but also as a measuring method.
　（７）実施例２～８
　上述した内容のフォトクロミック材料及び製造方法を用いて以下の表１に示す実施例２～８の試料を作製した。 (7) Examples 2 to 8
Samples of Examples 2 to 8 shown in Table 1 below were prepared using the photochromic material and manufacturing method described above.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　（８）着色強度及び退色化への添加物の影響の確認
　上記実施例２～５について、波長２５４ｎｍの紫外光を１０分間照射し、その後暗所に放置して、波長５２０ｎｍの吸光度をモニタリングした。この測定において、各実施例の着色強度及び時間経過による退色を確認した。図５は、各実施例の計測時間と波長５２０ｎｍの吸光度の関係を示すグラフである。また、図６は、図５に示す結果を常用対数で表示したグラフである。なお、符号１６が実施例２（ＢＭＳＦＡＢ１）、符号１７が実施例３（ＢＭＳＦＡＢ２）、符号１８が実施例４（ＢＭＳＢ）、符号１９が実施例５（ＢＭＳＡＢ）に該当する。 (8) Confirmation of influence of additive on coloring intensity and fading Example 2-5 were irradiated with ultraviolet light at a wavelength of 254 nm for 10 minutes, and then left in the dark to monitor the absorbance at a wavelength of 520 nm. . In this measurement, the color strength of each Example and fading with time were confirmed. FIG. 5 is a graph showing the relationship between the measurement time and the absorbance at a wavelength of 520 nm in each example. FIG. 6 is a graph showing the results shown in FIG. 5 in common logarithm. Reference numeral 16 corresponds to the second embodiment (BMSFAB1), reference numeral 17 corresponds to the third embodiment (BMSFAB2), reference numeral 18 corresponds to the fourth embodiment (BMSB), and reference numeral 19 corresponds to the fifth embodiment (BMSAB).
　図５に示すように、実施例２（ＢＭＳＦＡＢ１）及び実施例３（ＢＭＳＦＡＢ２）が、実施例４（ＢＭＳＢ）及び実施例５（ＢＭＳＡＢ）よりも着色強度が大きくなっていた。実施例２（ＢＭＳＦＡＢ１）及び実施例３（ＢＭＳＦＡＢ２）と、実施例５（ＢＭＳＡＢ）の比較から、Ｆｅの添加により、着色強度が向上することが明らかとなった。また、実施例４（ＢＭＳＢ）と実施例５（ＢＭＳＡＢ）の比較から、Ａｌの添加により着色持続性が向上することが明らかとなった。 As shown in FIG. 5, Example 2 (BMSFAB1) and Example 3 (BMSFAB2) had higher coloring intensity than Example 4 (BMSB) and Example 5 (BMSAB). From the comparison between Example 2 (BMSFAB1) and Example 3 (BMSFAB2) and Example 5 (BMSAB), it was revealed that the coloring strength was improved by the addition of Fe. Moreover, it became clear from the comparison of Example 4 (BMSB) and Example 5 (BMSAB) that coloring persistence improves by addition of Al.
　図６に示すように、実施例２～５の結果から、着色維持性に関して、退色化の初期期間では、Ｆｅの添加が着色維持性の向上に寄与し、退色化の中～長期間ではＡｌの添加が着色維持性の向上に寄与することが明らかとなった。 As shown in FIG. 6, from the results of Examples 2 to 5, regarding the color retention, the addition of Fe contributes to the improvement of the color retention in the initial period of color fading, and Al in the middle to long term of the color fading. It became clear that the addition of added contributes to the improvement of color retention.
　（９）吸収スペクトルの確認
　上記実施例２～８について、波長２５４ｎｍの紫外線を照射して、ＵＶ－ＶＩＳ－ＮＩＲ分光光度計で各実施例の吸収スペクトルを確認した。図７に吸収スペクトルを示している。なお、符号２１が実施例２（ＢＭＳＦＡＢ１）、符号２０が実施例３（ＢＭＳＦＡＢ２）、符号２２が実施例４（ＢＭＳＢ）、符号２３が実施例５（ＢＭＳＡＢ）、符号２４が実施例６（ＢＭＳＦ）、符号２５が実施例７（ＢＭＳ）、符号２６が実施例８（ＢＭＳＡ）に該当する。 (9) Confirmation of absorption spectra The above Examples 2 to 8 were irradiated with ultraviolet rays having a wavelength of 254 nm, and the absorption spectra of each example were confirmed with a UV-VIS-NIR spectrophotometer. FIG. 7 shows an absorption spectrum. Reference numeral 21 is the second embodiment (BMSFAB1), reference numeral 20 is the third embodiment (BMSFAB2), reference numeral 22 is the fourth embodiment (BMSB), reference numeral 23 is the fifth embodiment (BMSAB), and reference numeral 24 is the sixth embodiment (BMSF). ), 25 corresponds to Example 7 (BMS), and 26 corresponds to Example 8 (BMSA).
　図７に示すように、波長５２０ｎｍにおいて、実施例２（ＢＭＳＦＡＢ１）及び実施例３（ＢＭＳＦＡＢ２）が最も高いピークとなり、着色強度が大きいものであった。また、実施例２～８の結果から、着色強度に対する添加の効果は、Ｂ、Ｆｅ及びＡｌ添加＞Ｂ添加＞Ｆｅ添加＞Ａｌ添加の順番で影響するものとなることが明らかとなった。 As shown in FIG. 7, at the wavelength of 520 nm, Example 2 (BMSFAB1) and Example 3 (BMSFAB2) had the highest peak, and the coloring intensity was large. Further, from the results of Examples 2 to 8, it has been clarified that the effect of the addition on the coloring strength is influenced in the order of B, Fe and Al addition> B addition> Fe addition> Al addition.
　以上のように、本発明に係るＸ線記録材料は、繰り返し使用可能かつ耐久性を有し、実用性に優れたものとなっている。
　また、本発明に係るＸ線記録材料の製造方法は、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線記録材料を製造可能なものとなっている。
　また、本発明に係るＸ線記録媒体は、繰り返し使用可能かつ耐久性を有し、実用性に優れたものとなっている。
　また、本発明に係るＸ線記録媒体の製造方法は、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線記録媒体を製造可能なものとなっている。
　更に、本発明に係るＸ線照射量の測定方法は、繰り返し使用可能かつ耐久性を有し、実用性に優れたＸ線照射量の測定方法を提供するものとなっている。 As described above, the X-ray recording material according to the present invention is reusable and durable, and has excellent practicality.
In addition, the method for producing an X-ray recording material according to the present invention is capable of producing an X-ray recording material that can be used repeatedly, has durability, and has excellent practicality.
The X-ray recording medium according to the present invention is reusable and durable, and has excellent practicality.
In addition, the method for producing an X-ray recording medium according to the present invention can produce an X-ray recording medium that can be used repeatedly, has durability, and is highly practical.
Furthermore, the method for measuring an X-ray irradiation amount according to the present invention provides a method for measuring an X-ray irradiation amount that can be used repeatedly, has durability, and has excellent practicality.
　　　１　　　装置構成
　　　２　　　Ｘ線源
　　　３　　　スリット
　　　４　　　Ｘ線記録ペレット
　　　５　　　位置
　　　６　　　Ｘ線の照射エリア
　　　７　　　紫外可視分光法の測定エリア
　　　８　　　対象物
　　　９　　　透過画像
　　１０　　　Ｘ線照射後の吸収スペクトル
　　１１　　　加熱後の吸収スペクトル
　　１２　　　４０ｋＶ、３０ｍＡのＸ線を照射したサンプル
　　１３　　　４０ｋＶ、２０ｍＡのＸ線を照射したサンプル
　　１４　　　４０ｋＶ、１０ｍＡのＸ線を照射したサンプル
　　１５　　　図４の左側のグラフを対数表示したグラフ
　　１６　　　実施例２（ＢＭＳＦＡＢ１）
　　１７　　　実施例３（ＢＭＳＦＡＢ２）
　　１８　　　実施例４（ＢＭＳＢ）
　　１９　　　実施例５（ＢＭＳＡＢ）
　　２０　　　実施例３（ＢＭＳＦＡＢ２）
　　２１　　　実施例２（ＢＭＳＦＡＢ１）
　　２２　　　実施例４（ＢＭＳＢ）
　　２３　　　実施例５（ＢＭＳＡＢ）
　　２４　　　実施例６（ＢＭＳＦ）
　　２５　　　実施例７（ＢＭＳ）
　　２６　　　実施例８（ＢＭＳＡ） DESCRIPTION OF SYMBOLS 1 Apparatus configuration 2 X-ray source 3 Slit 4 X-ray recording pellet 5 Position 6 X-ray irradiation area 7 Measurement area of ultraviolet visible spectroscopy 8 Object 9 Transmission image 10 Absorption spectrum after X-ray irradiation 11 Absorption spectrum after heating 12 Sample irradiated with 40 kV, 30 mA X-ray 13 Sample irradiated with 40 kV, 20 mA X-ray 14 Sample irradiated with 40 kV, 10 mA X-ray 15 Graph showing the left graph of FIG. 4 in logarithm 16 Example 2 ( BMSFAB1)
17 Example 3 (BMSFAB2)
18 Example 4 (BMSB)
19 Example 5 (BMSAB)
20 Example 3 (BMSFAB2)
21 Example 2 (BMSFAB1)
22 Example 4 (BMSB)
23 Example 5 (BMSAB)
24 Example 6 (BMSF)
25 Example 7 (BMS)
26 Example 8 (BMSA)

Claims (8)

  1. 　フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料。 X-ray recording material containing a silicate compound exhibiting photochromic properties.
  2. 　前記ケイ酸塩化合物は少なくともバリウム及びマグネシウムを含有する
    　請求項１に記載のＸ線記録材料。     The X-ray recording material according to claim 1, wherein the silicate compound contains at least barium and magnesium.
  3. 　前記ケイ酸塩化合物の骨格を構成するＳｉＯ４－ＭｇＯ４ネットワーク構造のＳｉ及びＭｇの少なくとも一部がＦｅ、ＢまたはＡｌから選択される少なくとも１つの元素で置換された
    　請求項２に記載のＸ線記録材料。     The X of claim 2, wherein at least a part of Si and Mg in the SiO 4 —MgO 4 network structure constituting the skeleton of the silicate compound is substituted with at least one element selected from Fe, B, or Al. Line recording material.
  4. 　フォトクロミック性を示すケイ酸塩化合物を含有する粉状体を１１５０℃～１３００℃の還元雰囲気下で２時間以上焼成する工程を備える
    　Ｘ線記録材料の製造方法。     A method for producing an X-ray recording material comprising a step of firing a powder containing a silicate compound exhibiting photochromic properties in a reducing atmosphere at 1150 ° C. to 1300 ° C. for 2 hours or more.
  5. 　フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料が均一に配合された記録層を有すると共に、書き換え可能に構成された
    　Ｘ線記録媒体。     An X-ray recording medium having a recording layer in which an X-ray recording material containing a silicate compound exhibiting photochromic properties is uniformly blended and rewritable.
  6. 　Ｘ線の照射で蛍光を発すると共に、その発光スペクトルの波長範囲の少なくとも一部が、前記ケイ酸化合物が示す吸光度スペクトルの波長範囲と重複するシンチレータを含有する
    　請求項５に記載のＸ線記録媒体。     The X-ray recording medium according to claim 5, wherein the X-ray recording medium includes a scintillator that emits fluorescence when irradiated with X-rays and at least part of the wavelength range of the emission spectrum overlaps with the wavelength range of the absorbance spectrum exhibited by the silicate compound. .
  7. 　フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料であり、加熱して脱色可能に構成されたＸ線記録媒体に波長０．００１～１０ｎｍの範囲のＸ線を照射して着色する
    　Ｘ線記録媒体による記録方法。     An X-ray recording material containing a silicate compound exhibiting photochromic properties, and is colored by irradiating an X-ray recording medium configured to be decolorable by heating with X-rays in a wavelength range of 0.001 to 10 nm. X Recording method using a linear recording medium.
  8. 　フォトクロミック性を示すケイ酸塩化合物を含有するＸ線記録材料から構成されたＸ線記録媒体に波長０．００１～１０ｎｍの範囲のＸ線を照射して着色する着色工程と、
    　前記着色工程で得られた前記Ｘ線記録材料の着色量からＸ線照射量を検出する検出工程とを備える
    　Ｘ線照射量の測定方法。     A coloring step of irradiating an X-ray recording medium composed of an X-ray recording material containing a photosilicate silicate compound with X-rays in the wavelength range of 0.001 to 10 nm;
    A detection step of detecting an X-ray irradiation amount from a coloring amount of the X-ray recording material obtained in the coloring step. A method for measuring an X-ray irradiation amount.
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