JPWO2006006640A1 - Fluorescent glass - Google Patents

Abstract

The fluorescent glass realizing high density and high luminous efficiency contains the Ln2O3 component in an amount of more than 10.2% by mass or more than 2.8% by mol% (where Ln = Lu, Gd, Y, One or more selected from Dy and La), and the density is 3.0 g / cm 3 or more.

Description

  The present invention relates to a fluorescent glass that has a high density and efficiently emits fluorescence when excited by light, heat, radiation, or the like, and particularly relates to a scintillator glass that emits light efficiently by radiation excitation such as X-rays.

Substances that emit fluorescence efficiently when excited by light, heat, radiation, etc. are called phosphors. Of these, substances that emit fluorescence by radiation such as X-rays, γ-rays, and charged particles are called scintillation, and emit scintillation light. Is called a scintillator.
Scintillators are used in medical diagnostic apparatuses such as X-ray CT and PET (Postron Emission CT), non-destructive inspection apparatuses using radiation, and electromagnetic force calorimeters for high energy physical experiments.
Scintillators used for such applications mainly have characteristics such as high atomic number and density, high light emission, high transparency at the emission wavelength, fast decay of fluorescence, and strong resistance to radiation. Is required.
Of these, the atomic number and density are related to the absorption rate of radiation, which not only contributes to the downsizing of the detector but also improves the resolution of the irradiation position.
The absorptance is proportional to the fourth power of the atomic number in X-ray CT and PET having low radiation energy, and is proportional to the atomic number in the case of extremely large energy. In any case, a scintillator having a high atomic number and high density is required.
In addition to these characteristics, it is desired that the manufacturing cost is low, that a large size can be manufactured, and that various shapes can be easily manufactured.
At present, many inorganic scintillators such as single crystals, ceramics and glass are known.
Compared to single crystals or ceramics, glass has low luminous efficiency, but has high transparency and has the advantage of being easily fabricated into various shapes such as fibers, and so has been studied vigorously.
For example, US Pat. No. 3,654,172, US Pat. No. 5,122,671, and US Pat. No. 5,391,320 disclose scintillator glasses using Tb as an activator. However, all of these scintillator glasses are based on alkaline earth silicates and have a very limited application due to their low density.
JP-A-9-40440 and US Pat. No. 4,566,987 disclose scintillator glass using Ce as an activator. In addition, M.M. Bettinelli et al., “Physics and Chemistry of Glasses”, 1996, vol. 37, no. 1, p. 4-8 discloses a scintillator glass using Ce, Tb or Eu as an activator. However, these glasses were all low in density.
There have been attempts to introduce heavy metal oxides such as PbO and Bi ₂ O ₃ in order to increase the density of the glass. Although the density of the glass could be increased to ⁶ g / cm ⁶ or more, the light emission efficiency of the glass was remarkably lowered by the introduction thereof. Since rare earth oxides such as Gd ₂ O ₃ and La ₂ O ₃ have a large molecular weight, they can contribute to an improvement in the density of the glass. However, if they are introduced into the glass in a large amount, they tend to be difficult to vitrify. Gd ₂ O ₃ and La ₂ O ₃ are actually used in the scintillator glasses disclosed in Patent Document 2 and Patent Document 3 described above, but the content is limited to 20 wt% or less.
An object of the present invention is to provide a practically stable fluorescent glass, particularly a scintillator glass, which simultaneously realizes a high density and a high luminous efficiency.

As a result of searching for a practically stable glass composition for the purpose of obtaining a fluorescent glass having a high density, particularly a scintillator glass, the present inventor found that Ln ₂ O ₃ component (where Ln = Lu, Gd, Y, Dy, La 1) or more selected from the group consisting of more than 10.2% by mass, or more than 2.8% by mol%, and the density is 3.0 g / cm ³ or more. It came to make this invention.
Furthermore, the present inventor searched for a glass composition containing a high concentration of Gd ₂ O ₃ component or Lu ₂ O ₃ component and practically stable for the purpose of obtaining a fluorescent glass having a high density, particularly a scintillator glass. As a result, by adding a Ga ₂ O ₃ component or a GeO ₂ component to the SiO ₂ —BaO— (Gd ₂ O ₃ , Lu ₂ O ₃ ) system, the content of the Gd ₂ O ₃ component or the Lu ₂ O ₃ component is 16 A high-density glass that is practically stable even when the content is greater than or equal to mass% was found, and further, it was found that scintillation was strongly carried out by doping with Tb or Ce as an activator, leading to the present invention.
Furthermore, as a result of searching for a glass composition containing a high concentration of Ln ₂ O ₃ and being practically stable for the purpose of obtaining a fluorescent glass having a high density, particularly a scintillator glass, the present inventors have found SiO ₂ —B _2. By adding Ga ₂ O ₃ , GeO ₂ or P ₂ O ₅ component to the O ₃ -Ln ₂ O ₃ (Ln = one or more selected from Lu, Gd, Y, Dy, La) system, Ln ₂ O ₃ found a high-density glass that is practically stable even in the range of 16 to 45 mol%, and further found that scintillation was performed by doping with a Tb, Eu, Pr, Nd, Ce, Cr, or Mn component as an activator. The present invention has been made.
That is, a preferred embodiment of the present invention is represented by the following configuration.
(Constitution 1) Containing more than 10.2% of Ln ₂ O ₃ component by mass%, provided that Ln = one or more selected from Lu, Gd, Y, Dy, La, and a density of 3.0 g / Fluorescent glass or scintillator glass characterized by being cm ³ or more.
(Configuration 2) Containing more than 2.8% of Ln ₂ O ₃ component in mol%, provided that Ln = one or more selected from Lu, Gd, Y, Dy, La, and a density of 3.0 g / Fluorescent glass or scintillator glass characterized by being cm ³ or more.
(Configuration 3) In mass%,
SiO ₂ 5-50%, and Ga ₂ O ₃ + GeO ₂ 1-25%, and BaO 10-40%, and Gd ₂ O ₃ + Lu ₂ O ₃ 16-45%, and Tb ₂ O ₃ + Ce ₂ O ₃ 0 .01-20%,
And
B ₂ O ₃ 0~45%, and / or _P 2 _O 5 0~10%, and / or _{Y 2 O 3 + La 2 O} 3 0~20%, and / or RO 0%
However, at least one selected from R = Mg, Ca, Sr, Zn and / or Rn ₂ O 0-15%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%, and / or _X 2 _O 3 0-5%
However, X = Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb, or one or more types selected from Mn,
The fluorescent glass or scintillator glass according to Configuration 1, wherein each of the components is contained.
(Configuration 4) In mass%,
SiO ₂ 5 to 50%, and _Ga 2 _O 3 _1~25%, and BaO 10 to 40%, and _{Gd 2 O 3 + Lu 2 O} 3 16~45%, and _{Tb 2 O 3 + Ce 2 O} 3 0.01 ~ 20%
And
B ₂ O ₃ 0~45%, and / or _P 2 _O 5 0~10%, and / or _{Y 2 O 3 + La 2 O} 3 0~20%, and / or RO 0%
However, at least one selected from R = Mg, Ca, Sr, Zn and / or Rn ₂ O 0-15%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%, and / or _X 2 _O 3 0-5%
However, X = Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb, or one or more types selected from Mn,
The fluorescent glass or scintillator glass according to Configuration 1, wherein each of the components is contained.
(Configuration 5) In mass%,
SiO ₂ 5-50%, and GeO ₂ 1-25%, and BaO 10-40%, and Gd ₂ O ₃ + Lu ₂ O ₃ 16-45%, and Tb ₂ O ₃ + Ce ₂ O ₃ 0.01-20 %,
And
B ₂ O ₃ 0~45%, and / or _P 2 _O 5 0~10%, and / or _{Y 2 O 3 + La 2 O} 3 0~20%, and / or RO 0%
However, at least one selected from R = Mg, Ca, Sr, Zn and / or Rn ₂ O 0-15%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%, and / or _X 2 _O 3 0-5%
However, X = Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb, or one or more types selected from Mn,
The fluorescent glass or scintillator glass according to Configuration 1, wherein each of the components is contained.
(Constitution 6) The fluorescent glass or scintillator glass according to any one of constitutions 1, 3, 4, or 5, characterized by containing 0.5 to 8% of a P ₂ O ₅ component by mass%.
(Arrangement 7) The fluorescent glass or scintillator glass according to any one of Arrangements 3, 4, or 6, wherein a part of the Ga ₂ O ₃ component is replaced with an Al ₂ O ₃ component.
(Configuration 8) The fluorescent glass or scintillator glass according to any one of configurations 3, 4, 6, or 7, wherein a part of the Ga ₂ O ₃ component is replaced with an AlF ₃ component or a GaF ₃ component.
(Configuration 9) characterized in that Ln ₂ O ₃ component in glass, wherein Ln = Y, La, Dy, Gd, Lu is replaced with one or more selected from LnF ₃ component consisting of the same cation component, The fluorescent glass or scintillator glass according to any one of configurations 1, 3, 4, 5, 6, 7 or 8, wherein the substitution rate is 60% by mass or less with respect to the content of the Ln ₂ O ₃ component before substitution.
(Configuration 10) _SiO 2 1~60% by mol%, and _B 2 _O 3 _{1~60%
However, SiO 2 + B 2 O 3} 25~65%, and _{GeO 2 + Ga 2 O 3 1~40} %, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, and La, and X ₂ O ₃ 0.01 to 15%
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%
The fluorescent glass or scintillator glass according to Configuration 2, which contains each of the following components.
(Configuration 11) 1 mol% SiO ₂ 1-60% and B ₂ O ₃ 1-60%
_{However, SiO 2 + B 2 O 3} 25~60%, and _{GeO 2 + Ga 2 O 3 1~40} %, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, La, and X ₂ O ₃ 0.01 to 15%,
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%
The fluorescent glass or scintillator glass according to Configuration 2, which contains each of the following components.
(Configuration 12) _SiO 2 1~60% by mol%, and _B 2 _O 3 _{1~60%
However, SiO 2 + B 2 O 3} 25~60%, and _Ga 2 _O 3 _1~40%, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, and La, and X ₂ O ₃ 0.01 to 15%
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%
The fluorescent glass or scintillator glass according to Configuration 2, which contains each of the following components.
(Configuration 13) _SiO 2 1~60% by mol%, and _B 2 _O 3 _{1~60%
However, SiO 2 + B 2 O 3} 25~60%, and _GeO 2 1 to 40%, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, and La, and X ₂ O ₃ 0.01 to 15%
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%
The fluorescent glass or scintillator glass according to Configuration 2, which contains each of the following components.
(Arrangement 14) The fluorescent glass or scintillator glass according to any one of Arrangements 2, 10, 11, 12, or 13, characterized by containing 0.5 to 8% of P ₂ O ₅ component in mol% .
(Configuration 15) The fluorescent glass or scintillator glass according to any one of Configurations 10 to 14, wherein one or _{two of the} Ga ₂ O ₃ component and the GeO ₂ component are replaced with an Al ₂ O ₃ component. .
(Configuration 16) The fluorescent glass or scintillator glass according to any one of configurations 10, 11, 12, 14, or 15, wherein a part of Ga ₂ O ₃ is replaced with GaF ₃ or AlF ₃ .
(Structure 17) Ln ₂ O ₃ component, wherein one or more selected from Ln = Y, La, Dy, Gd, and Lu are replaced with LnF ₃ component, and the substitution rate is Ln ₂ before substitution The fluorescent glass or scintillator glass according to any one of configurations 2, 10, 11, 12, 13, 14, 15, or 16, which is 60 mol% or less based on the total content of O ₃ components.
(Structure 18) X ₂ O ₃ component, wherein X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, Mn, or a part or all of one or more selected from Xb ₃ is replaced with XF ₃ component The fluorescent glass or scintillator glass according to any one of configurations 10 to 17.
(Arrangement 19) The fluorescent glass according to any one of Arrangements 2, 10, 11, 12, 13, 14, 15, 16, 17, or 18, wherein the density is 4.0 g / cm ³ or more. Scintillator glass.
(Configuration 20) The fluorescent glass or scintillator glass according to any one of Configurations 1 to 19, wherein the decay time is 5 ms or less.
(Arrangement 21) The fluorescent glass or scintillator glass according to any one of Arrangements 1 to 20, which contains a Ce component and has a decay time of 1 μs or less.
(Configuration 22) The fluorescent glass or scintillator glass according to any one of configurations 1 to 21 used as a scintillator.
(Configuration 23) A radiation measurement apparatus using the fluorescent glass according to any one of Configurations 1 to 22.
(Configuration 24) A CT apparatus using the fluorescent glass according to any one of Configurations 1 to 22.
According to the present invention, the Ln ₂ O ₃ component (however, one or more selected from Ln = Lu, Gd, Y, Dy, La) is contained in an amount exceeding 10.2% by mass%, or in mol% It is possible to provide a fluorescent glass or a scintillator glass that contains more than 2.8% and has a high density of 3.0 g / cm ³ or more.
In particular, according to the configurations 3 to 9, 20, 21, and 22 of the present invention, a large amount of Gd ₂ O ₃ component or Lu ₂ O ₃ component is introduced into the silicate glass and further doped with Tb or Ce ions. It is possible to provide a practically stable fluorescent glass, particularly a scintillator glass, which has high density and high light transparency from the ultraviolet region to the near infrared region, and which is scintillated with high luminous efficiency by excitation of X-rays.
In particular, according to the configurations of the present invention from 10 to 19, 20, 21, and 22, rare earth oxidation such as Lu ₂ O ₃ , Dy ₂ O ₃ , Gd ₂ O ₃ , La ₂ O ₃ , Y ₂ O ₃ components, etc. A practically stable fluorescent glass that can contain 16 mol% or more of a substance, can be further doped with Tb, Eu, Pr, Nd, Ce, Yb, Cr, Mn ions, and realizes high density and high luminous efficiency at the same time, In particular, a scintillator glass can be provided.
Furthermore, a radiation measuring apparatus and a CT apparatus can be obtained using the fluorescent glass or scintillator glass of the present invention, and can be manufactured at a lower cost than using a single crystal scintillator.

FIG. 1 shows emission spectra of Example 1 and Comparative Example 1 when excited with light having a wavelength of 278 nm. The horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit).
FIG. 2 is a transmittance curve of the glass of Example 10. The horizontal axis represents wavelength (nm), and the vertical axis represents transmittance (%).
FIG. 3 is an excitation spectrum of the glass of Examples 10 and 12 and the scintillator single crystal Bi ₄ Ge ₃ O ₁₂ (BGO). The horizontal axis is the excitation wavelength (nm), the vertical axis is the emission intensity (arbitrary unit), the excitation bands in Examples 10 and 12 are those when the fluorescence wavelength is monitored at 545 nm, and the excitation band for BGO is the fluorescence wavelength at 486 nm. It is the one when monitoring.
FIG. 4 is a fluorescence spectrum of the glass of Examples 10 and 12 and scintillator single crystal Bi ₄ Ge ₃ O ₁₂ (BGO). The horizontal axis is the fluorescence wavelength (nm), the vertical axis is the emission intensity (arbitrary unit), the emission intensity of Examples 10 and 12 is the one when the excitation wavelength is 260 nm, and the emission intensity of BGO is the excitation wavelength of 295 nm. When used.

The fluorescent glass of the present invention will be described. In the glass of the present invention, Ln ₂ O ₃ The component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) greatly contributes to an increase in the density of the glass and is an essential component for achieving the object of the present invention. The density of the fluorescent glass of the present invention is obtained by containing the lower limit of the total content of one or more of these components in excess of 10.2 by mass% or more than 2.8% in mol%. 3.0 g / cm ³ This can be done.
The reason why the composition of the glass having the configurations of 3 to 9 of the present invention is limited as described above will be described below. Hereinafter, the content of each component is expressed in mass% unless otherwise specified.
SiO ₂ The component is a glass-forming oxide and is an essential component for obtaining a stable glass. In order to obtain stable glass, the lower limit of the content is preferably 5%, more preferably 10%, and most preferably 15%. In order for the glass to reach a desired high density, the upper limit of the content is preferably 50%, more preferably 46%, and most preferably 42%.
B ₂ O ₃ Since the component has an effect on the meltability and stability of the glass, it can be optionally added. In order to obtain these effects, the lower limit of the content is more preferably 3%, and most preferably 5%. In order to obtain a desired high-density glass, the upper limit of the content is preferably 45%, more preferably 40%, and most preferably 35%.
Ga ₂ O ₃ Component or GeO ₂ The components are effective in improving the density of the glass, lowering the melting point of the glass, and improving the stability and meltability of the glass. ₂ O ₃ Ingredient or Lu ₂ O ₃ Since it greatly contributes to an increase in the content of components, a deviation is indispensable for obtaining the glass of the present invention. In order to obtain the effect sufficiently, the lower limit of the content when only one of these is introduced or the total content of the two types is preferably 1%, and is 1.3% Is more preferable, and 1.6% is most preferable.
In order to obtain good meltability of glass and to facilitate vitrification, Ga ₂ The upper limit of the content of the O3 component is preferably 25%, more preferably 20%, and most preferably 15%. GeO ₂ The larger the amount of the component, the more advantageous for the formation of glass. However, since it is a very expensive component, the upper limit of its content is preferably 25%, more preferably 20%, and 15%. Most preferably. These two components can achieve the object of the present invention by introducing them alone into the glass, but it is more effective if they are introduced simultaneously. The upper limit of the content of one or two of these two components is preferably 25%, more preferably 20%, and most preferably 15%.
Al ₂ O ₃ The component is effective in improving the meltability of the glass, Ga ₂ O ₃ It is an optional component that can be introduced into the glass in the form of replacing some of the components. In order not to reduce the density of the glass, partial replacement is preferable. Specifically, Ga ₂ O ₃ Al to replace ingredients ₂ O ₃ The upper limit of the component substitution rate is Ga before substitution. ₂ O ₃ It is preferable to set it as 90 mass% with respect to content of a component, It is more preferable to set it as 85 mass%, It is most preferable to set it as 80 mass%.
P ₂ O ₅ A component is a component which can be added arbitrarily and has the effect of improving the stability of the glass. Especially Tb which is a luminescent ion ³⁺ It is desirable to add it because it is advantageous to maintain the state in that state. In order to sufficiently obtain these effects, the lower limit of the content is more preferably 0.5%, and most preferably 1%. The upper limit with preferable content is 10%, and when it exceeds the value, stability of glass will worsen on the contrary. A more preferred upper limit is 8%, and a most preferred upper limit is 6%.
The BaO component is Gd described later. ₂ O ₃ Ingredient or Lu ₂ O ₃ It contributes to the increase in the density of the glass together with the components, and further has an effect of improving the stability and meltability of the glass, so that it is an essential component for achieving the object of the present invention. In order to sufficiently obtain the effect, the lower limit of the content is preferably 10%, more preferably 11%, and most preferably 12%. However, the preferable upper limit of the content is 40%. ₂ O ₃ Ingredient or Lu ₂ O ₃ Since it is necessary to reduce the content of components, the density is lowered. A more preferred upper limit is 35%, and a most preferred upper limit is 30%.
Gd ₂ O ₃ Ingredient or Lu ₂ O ₃ The component greatly contributes to the increase in the density of the glass and is an indispensable component for achieving the object of the present invention. In order to obtain a high-density glass, the lower limit of the total content of one or two of these components is preferably 16%, more preferably 19%, and most preferably 22%. . However, the upper limit of the content is preferably 45%, more preferably 42%, and most preferably 40% in order to improve the meltability and stability of the glass and vitrify it. .
Lu ₂ O ₃ Is particularly important because it has an extremely high effect of increasing the density of the glass. ₂ O ₃ And Ln ₂ O ₃ Lu for the total content of ₂ O ₃ Most preferably, the content of the components is 5% by mass or more.
La ₂ O ₃ Ingredient or Y ₂ O ₃ Since the component is effective in improving the density of the glass, it can be arbitrarily added. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 20%, more preferably 15%, and most preferably 10%.
AlF ₃ Component or GaF ₃ The component is an optional component that lowers the melting point of the glass and is effective in improving the meltability and stability of the glass. ₂ O ₃ It is most effective to add in the form of replacing some of the ingredients. However, in order to increase the density of the glass, Ga ₂ O ₃ AlF to replace ingredients ₃ Component or GaF ₃ The upper limit of the component substitution rate is Ga before substitution. ₂ O ₃ It is more preferable to set it as 90 mass% with respect to the quantity of a component, and it is most preferable to set it as 80 mass%.
LnF ₃ The component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) lowers the melting point of the glass and is effective in improving the meltability and stability of the glass. ₂ O ₃ It is a component that can be optionally added in the form of replacing the component, especially Gd ₂ O ₃ Ingredient or Lu ₂ O ₃ It is most effective to add in the form of replacing some of the components. But replace LnF ₃ The substitution rate of the component is Ln before substitution. ₂ O ₃ It should be at most 60% by mass relative to the content of the components. If this value is exceeded, the stability of the glass will be further reduced. More preferred LnF ₃ The substitution rate of the component is Ln before substitution. ₂ O ₃ It is 50 mass% or less with respect to content of a component, and 40 mass% or less is the most preferable.
The introduction of fluoride not only has the above effect but also Tb which is a luminescent ion described later. ³⁺ Or Ce ³⁺ Since the effect as a reducing agent is exhibited in order to maintain the state in that state, there is also an effect that contributes to the improvement of the light emission characteristics.
Tb ³⁺ Or Ce ³⁺ Ions are indispensable for realizing the scintillation characteristics of the glass of the present invention, which plays a role of emission center. These ions are Tb ₂ O ₃ , Ce ₂ O ₃ , CeO ₂ Alternatively, it can be introduced in the form of fluoride. Tb ₂ O ₃ Or Ce ₂ O ₃ In order to obtain a sufficient light emission intensity, the lower limit of the content of one or two of these two components is preferably 0.01%, and 0.05%. Is more preferable and 0.1% is most preferable. However, since the emission intensity is drastically reduced when concentration quenching occurs, the upper limit of the content of one or two types is preferably 20%, more preferably 18%, and more preferably 15%. Is most preferred.
Tb mentioned above ³⁺ In order to increase the luminescence of ions, Pr as a sensitizer ₂ O ₃ , Nd ₂ O ₃ , Sm ₂ O ₃ , Eu ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Yb ₂ O ₃ , Mn ₂ O ₃ , Bi ₂ O ₃ , Mn ₂ O ₃ , Cr ₂ O ₃ Etc. can be added. However, the maximum addition amount should be suppressed to 5% or less in total of these components. If the addition amount exceeds that value, light emission is weakened. These ions may be introduced into the glass in the form of fluoride or chloride in addition to the oxide form as described above.
The RO component (one or more selected from R = Mg, Ca, Sr, and Zn) is an ingredient that can be arbitrarily added because it lowers the melting point of the glass and improves the meltability of the glass. In order to obtain this effect, the lower limit of the total content of these components is more preferably 0.5%, and most preferably 1%. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 10%, more preferably 8%, and most preferably 5%. The RO component is most preferably MgO.
Rn ₂ The O component (one or more selected from Rn = Li, Na, K, and Cs) is also a component that can be optionally added because it lowers the melting point of the glass and improves the meltability of the glass. In order to obtain this effect, the lower limit of the total content of these components is more preferably 1%, and most preferably 3%. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 15%, more preferably 12%, and most preferably 10%.
ZrO ₂ , SnO ₂ , Nb ₂ O ₅ And Ta ₂ O ₅ These components are optional components that have the effect of increasing the density of the glass, and it is desirable to add them in order to obtain a glass with a higher density. Therefore, the upper limit of the total content of one or more of these components is preferably 8%, more preferably 5%, and most preferably 3%.
As ₂ O ₃ Ingredient or Sb ₂ O ₃ The component is Tb that serves as a clarifier during glass melting or the above-described emission center. ³⁺ Or Ce ³⁺ However, the total amount of one or two of them is sufficient to be 5% or less. A more preferable upper limit of the total amount is 3%.
Although the glass of composition 3 to composition 9 of the present invention cannot be represented by the description of mol% directly because the composition is represented by mass%, the glass of composition 3 to composition 9 has been described. In order to achieve the effect of each component, the content of each component by mol% display is generally in the following range.
SiO ₂ The component is a glass-forming oxide and is an essential component for obtaining a stable glass. In order to obtain stable glass, the lower limit of the content is preferably 5 mol%, more preferably 10 mol%, and most preferably 15 mol%. In order for the glass to reach a desired high density, the upper limit of the content is preferably 65 mol%, more preferably 61 mol%, and most preferably 59 mol%.
B ₂ O ₃ Since the component has an effect on the meltability and stability of the glass, it can be optionally added. In order to obtain these effects, the lower limit of the content is more preferably 4.5 mol%, and most preferably 7.5 mol%. In order to obtain a desired high-density glass, the upper limit of the content is preferably 60 mol%, more preferably 50 mol%, and most preferably 40 mol%.
Ga ₂ O ₃ Component or GeO ₂ The components are effective in improving the density of the glass, lowering the melting point of the glass, and improving the stability and meltability of the glass. ₂ O ₃ Ingredient or Lu ₂ O ₃ Since it greatly contributes to an increase in the content of components, a deviation is indispensable for obtaining the glass of the present invention. In order to sufficiently obtain the above effect, the lower limit of the content when only one of these is introduced or the total content of the two types is preferably 0.5 mol%, 0.8 mol% It is more preferable to set it as 1.1 mol%.
In order to obtain good meltability of glass and to facilitate vitrification, Ga ₂ O ₃ The upper limit of the component content is preferably 25 mol%, more preferably 18 mol%, and most preferably 11 mol%. GeO ₂ The higher the amount of the component, the more advantageous it is for glass formation. However, since it is a very expensive component, the upper limit of its content is preferably 38 mol%, more preferably 28 mol%, and 18 mol%. Most preferably. These two components can achieve the object of the present invention by introducing them alone into the glass, but it is more effective if they are introduced simultaneously. The upper limit of the content of one or two of these two components is preferably 40 mol%, more preferably 30 mol%, and most preferably 25 mol%.
Al ₂ O ₃ The component is effective in improving the meltability of the glass, Ga ₂ O ₃ It is an optional component that can be introduced into the glass in the form of replacing some of the components. However, in order not to reduce the density of the glass, partial replacement is more preferable.
Specifically, Ga ₂ O ₃ Al to replace ingredients ₂ O ₃ The upper limit of the component substitution rate is Ga before substitution. ₂ O ₃ It is preferable to set it as 94 mol% with respect to content of a component, It is more preferable to set it as 91 mol%, It is most preferable to set it as 88 mol%.
P ₂ O ₅ A component is a component which can be added arbitrarily and has the effect of improving the stability of the glass. Especially Tb which is a luminescent ion ³⁺ It is desirable to add it because it is advantageous to maintain the state in that state. In order to obtain these effects, the lower limit of the content is more preferably 0.3 mol%, and most preferably 0.7 mol%. The upper limit with preferable content is 12 mol%, and when the value is exceeded, the stability of glass will worsen on the contrary. A more preferred upper limit is 8 mol%, and a most preferred upper limit is 5 mol%.
The BaO component is Gd described later. ₂ O ₃ Ingredient or Lu ₂ O ₃ It contributes to the increase in the density of the glass together with the components, and further has an effect of improving the stability and meltability of the glass, so that it is an essential component for achieving the object of the present invention. In order to obtain the effect sufficiently, it is preferable to contain more than 5 mol%. A more preferable lower limit of the content is 6 mol%, and a most preferable lower limit of the content is 7 mol%. However, the preferable upper limit of the content is 50 mol%, and if the value is exceeded, Gd described later ₂ O ₃ Ingredient or Lu ₂ O ₃ Since it is necessary to reduce the content of components, the density is lowered. A more preferred upper limit is 39 mol%, and a most preferred upper limit is 28 mol%.
Gd ₂ O ₃ Ingredient or Lu ₂ O ₃ The component greatly contributes to the increase in the density of the glass and is an indispensable component for achieving the object of the present invention. In order to obtain a glass having a high density, the lower limit of the total content of one or two of these components is preferably 5 mol%, more preferably 5.4 mol%, and 5.8 mol%. Most preferred. However, the upper limit of the content is preferably 30 mol%, more preferably 23 mol%, and most preferably 16 mol% in order to improve the meltability and stability of the glass and vitrify it.
Lu ₂ O ₃ Is particularly important because it has an extremely high effect of increasing the density of the glass. ₂ O ₃ And Ln ₂ O ₃ Lu for the total content of ₂ O ₃ The component content is most preferably 5 mol% or more.
La ₂ O ₃ Ingredient or Y ₂ O ₃ Since the component is effective in improving the density of the glass, it can be arbitrarily added. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 20 mol%, more preferably 15 mol%, and most preferably 10 mol%.
AlF ₃ Component or GaF ₃ The component is an optional component that lowers the melting point of the glass and is effective in improving the meltability and stability of the glass. ₂ O ₃ It is most effective to add in the form of replacing some of the ingredients. However, in order to increase the density of the glass, Ga ₂ O ₃ AlF to replace ingredients ₃ Component or GaF ₃ The upper limit of the component substitution rate is Ga before substitution. ₂ O ₃ More preferably, it is 95 mol% with respect to content of a component, and it is most preferable to set it as 90 mol%.
LnF ₃ The component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) lowers the melting point of the glass and is effective in improving the meltability and stability of the glass. ₂ O ₃ It is a component that can be optionally added in the form of replacing the component, especially Gd ₂ O3 component or Lu ₂ O ₃ It is most effective to add in the form of replacing some of the components. But replace LnF ₃ The substitution rate of the component is Ln before substitution. ₂ O ₃ It should be at most 70 mol% with respect to the content of the components. If this value is exceeded, the stability of the glass will be further reduced. More preferred LnF ₃ The substitution rate of the component is Ln before substitution. ₂ O ₃ It is 65 mol% or less with respect to content of a component, and 50 mol% or less is the most preferable.
The introduction of fluoride not only has the above effect but also Tb which is a luminescent ion described later. ³⁺ Or Ce ³⁺ Since the effect as a reducing agent is exhibited in order to maintain the state in this state, there is also an effect that contributes to the improvement of the light emission characteristics.
Tb ³⁺ Or Ce ³⁺ Ions are indispensable for realizing the scintillation characteristics of the glass of the present invention, which plays a role of emission center. These ions are Tb ₂ O ₃ , Ce ₂ O ₃ , CeO ₂ Alternatively, it can be introduced in the form of fluoride. Tb ₂ O ₃ Or Ce ₂ O ₃ In order to obtain sufficient emission intensity, the lower limit of the content of one or two of these two components is preferably 0.005 mol%, and 0.01 mol%. Is more preferable, and 0.05 mol% is most preferable. However, since the emission intensity drastically decreases when concentration quenching occurs, the upper limit of the content of one or two types is preferably 15 mol%, more preferably 11 mol%, and more preferably 7 mol%. Is most preferred.
Tb mentioned above ³⁺ In order to increase the luminescence of ions, Pr as a sensitizer ₂ O ₃ , Nd ₂ O ₃ , Sm ₂ O ₃ , Eu ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Yb ₂ O ₃ , Mn ₂ O ₃ , Bi ₂ O ₃ , Mn ₂ O ₃ , Cr ₂ O ₃ Etc. can be added. However, the maximum addition amount should be 8 mol% or less in total of these components, and if added exceeding that value, the light emission becomes weak. These ions may be introduced into the glass in the form of fluoride or chloride in addition to the oxide form as described above.
The RO component (one or more selected from R = Mg, Ca, Sr, and Zn) is an ingredient that can be arbitrarily added because it lowers the melting point of the glass and improves the meltability of the glass. In order to obtain this effect, the lower limit of the total content of these components is more preferably 2 mol%, and most preferably 4 mol%. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 10 mol%, more preferably 9.6 mol%, and most preferably 9.2 mol%. The RO component is most preferably MgO.
Rn ₂ The O component (one or more selected from Rn = Li, Na, K, and Cs) is also a component that can be optionally added because it lowers the melting point of the glass and improves the meltability of the glass. In order to obtain this effect, the lower limit of the total content of these components is more preferably 4 mol%, and most preferably 8 mol%. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 20 mol%, more preferably 19.5 mol%, and most preferably 19 mol%.
ZrO ₂ , SnO ₂ , Nb ₂ O ₅ And Ta ₂ O ₅ These components are optional components that have the effect of increasing the density of the glass, and it is desirable to add them in order to obtain a glass with a higher density. Therefore, the upper limit of the total content of one or more of these components is preferably 5 mol%, more preferably 3 mol%, and most preferably 2 mol%.
As ₂ O ₃ Ingredient or Sb ₂ O ₃ The component is Tb that serves as a clarifier during glass melting or the above-described emission center. ³⁺ Or Ce ³⁺ However, the total amount of one or two of them is sufficient to be 5 mol% or less. The upper limit of the more preferable total amount is 3 mol%.
The reason why the composition of the fluorescent glass or scintillator glass having the configurations 10 to 19 of the present invention is limited as described above will be described below. Hereinafter, the description of the content of each component is expressed in mol% unless otherwise specified.
SiO ₂ Ingredients and B ₂ O ₃ The component is a glass-forming oxide and is an essential component for obtaining a stable glass. However, when either one is introduced into the glass alone, Ln ₂ O ₃ Since it is difficult to incorporate a component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) into glass at a high concentration, both components must be introduced.
To obtain a stable glass, SiO ₂ The lower limit of the component content is preferably 1%, more preferably 3%, most preferably 5%, B ₂ O ₃ The lower limit of the component content is preferably 1%, more preferably 3%, most preferably 5%, and the lower limit of the total content of both components is preferably 25%. 30% is more preferable, and 35% is most preferable. Also, in order for the glass to reach the desired high density, SiO ₂ The upper limit of the component content is preferably 60%, more preferably 55%, and most preferably 50%. ₂ O ₃ The upper limit of the components is preferably 60%, more preferably 55%, most preferably 50%, and the upper limit of the total content of both components is preferably 65%. In particular, if the upper limit of the content of both components is 60%, Ln ₂ O ₃ More preferably, the component can be contained in an amount of 20% or more, and a glass with a higher density can be easily obtained.
Ga ₂ O ₃ Component or GeO ₂ The components are effective in improving the density of the glass, lowering the melting point of the glass, and improving the stability and meltability of the glass. ₂ O ₃ One of them is indispensable for obtaining the glass of the present invention because it greatly contributes to an increase in the component content.
In order to obtain the effect sufficiently, the lower limit of the content when only one of these is introduced or the total content of the two types is preferably 1%, more preferably 2% Preferably, 5% is most preferable.
In order to obtain good meltability of the glass and to facilitate vitrification, the upper limit of the content of the Ga2O3 component is preferably 40%, more preferably 35%, and more preferably 30%. Most preferred. GeO ₂ The greater the amount of the component, the more advantageous for the formation of glass, but since it is a very expensive component, the upper limit of its content is preferably 40%, more preferably 35%, and 30%. Most preferably.
The above two components can be introduced alone into the glass, but it is more effective to introduce the two components together. The upper limit of the content of one or two of these two components is preferably 40%, more preferably 35%, and most preferably 30%.
Ga ₂ O ₃ Components and GeO ₂ One or two of the ingredients are Al ₂ O ₃ Can be replaced with ingredients. However, if completely replaced, the meltability and stability of the glass deteriorate, so partial replacement is more preferable. Specifically, Ga ₂ O ₃ Components and GeO ₂ Al to replace one or two of the ingredients ₂ O ₃ Change the substitution rate of the component to Ga before substitution ₂ O ₃ Components and GeO ₂ It is preferable to suppress to 95 mol% or less based on the total content of one or two components. A more preferred substitution rate is 90 mol% or less, and a most preferred substitution rate is 85 mol% or less.
P ₂ O ₅ The component is an optional component having an effect of improving the stability of the glass. Especially Tb which is a luminescent ion ³⁺ Or Ce ³⁺ It is desirable to add it because it is advantageous to maintain the state in that state. In order to obtain these effects, the lower limit of the content is more preferably 0.5%, and most preferably 1%. The upper limit with preferable content is 10%, and when it exceeds the value, stability of glass will worsen on the contrary. A more preferred upper limit is 8%, and a most preferred upper limit is 7%.
Ln ₂ O ₃ The component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) greatly contributes to an increase in the density of the glass and is an essential component for achieving the object of the present invention. Even if only one of these components is contained, a desired glass can be obtained. However, if two or more of these components are contained, the meltability and stability of the glass are further improved. In order to obtain a glass having a high density, the lower limit of the total content of one or more of these components is preferably 16%, more preferably 20%, and more preferably 25%. Most preferred. However, in order to maintain good meltability and stability for vitrification, the upper limit of the total content is preferably 45%, more preferably 43%, and more preferably 42%. Most preferred.
Of these ingredients, Lu ₂ O ₃ Is particularly important because it has an extremely high effect of increasing the density of the glass. ₂ O ₃ Lu for the total content of ingredients ₂ O ₃ The component content is most preferably 5 mol% or more.
AlF ₃ Component or GaF ₃ The component lowers the melting point of the glass and is effective in improving the meltability and stability of the glass. ₂ O ₃ It is most effective to add in a form that replaces a part of. However, to improve the stability of the glass, AlF ₃ Ingredients or GaF ₃ The substitution rate of components is Ga before substitution. ₂ O ₃ More preferably, it is 90 mol% or less, and most preferably 80 mol% or less, relative to the component content.
LnF ₃ The component (one or more selected from Ln = Y, La, Day, Gd, and Lu) is effective in lowering the melting point of the glass and improving the meltability and stability of the glass. ₂ O ₃ It is most effective to add in the form of replacing some of the components. However, LnF ₃ The substitution rate of the component is Ln before substitution. ₂ O ₃ It should be at most 60 mol% with respect to the total content of the components. If this value is exceeded, the stability of the glass will be further reduced. More preferred LnF ₃ The substitution rate of the component is Ln before substitution ₂ O ₃ It is 55% or less with respect to the sum total of content of a component, and 50% or less is the most preferable.
The introduction of fluoride not only has the above effect but also Tb which is a luminescent ion described later. ³⁺ Or Ce ³⁺ Since the effect as a reducing agent is exhibited in order to maintain the state in this state, there is also an effect that contributes to the improvement of the light emission characteristics.
X ₂ O ₃ The component (one or more selected from X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, and Mn) plays the role of a luminescent center and is an indispensable component for realizing the scintillation characteristics of the present invention. Since these components have different emission wavelengths, scintillators having various wavelengths can be realized by introducing them alone into glass. Furthermore, when two types (for example, Tb and Ce ions) are introduced in a combination, energy transfer between ions occurs, and light emission may be greatly amplified.
In order to obtain sufficient emission intensity, the lower limit of the total content of one or more of these components is preferably 0.01%, more preferably 0.02%, 0.05 % Is most preferable. However, since the emission intensity is drastically reduced when concentration quenching occurs, the upper limit of the content is preferably 15%, more preferably 12%, and most preferably 10%.
Among these components, Tb ₂ O ₃ , Eu ₂ O ₃ , Ce ₂ O ₃ Since the component has a particularly good effect as the emission center, Pr ₂ O ₃ , Na ₂ O ₃ , Yb ₂ O ₃ , Cr ₂ O ₃ , Mn ₂ O ₃ X not included ₂ O ₃ All ingredients are Tb ₂ O ₃ , Eu ₂ O ₃ , Ce ₂ O ₃ Of these, it is particularly preferable to use one or more of them.
In the case of Tb and Ce, Tb ³⁺ And Tb ⁴⁺ , Ce ³⁺ And Ce ⁴⁺ The two types of states can exist, but it is Tb that emits light ³⁺ Or Ce ³⁺ Therefore, it is desirable to use a reducing agent or to produce the glass in a slightly reducing atmosphere. These luminescent ions may be introduced into the glass in the form of fluoride or chloride in addition to the oxide form as described above.
X above ₂ O ₃ All or part of the components (one or more selected from X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, Mn) ₃ It is also possible to introduce luminescent ions into the glass by replacing the components. However, to improve the stability of the glass, XF ₃ The substitution rate of the component is X before substitution ₂ O ₃ More preferably, it is 90 mol% or less, and most preferably 80 mol% or less with respect to the total content of the components.
In order to enhance the emission of the above-mentioned luminescent ions, Sm is used as a sensitizer. ₂ O ₃ , HO ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Bi ₂ O ₃ Ingredients can be added. However, the maximum addition amount should be suppressed to 3 mol% or less, and if the addition exceeds that value, light emission is weakened.
The RO component (one or more selected from R = Mg, Ca, Sr, Ba, and Zn) is an optionally added component that has the effect of lowering the melting point of the glass and improving the meltability of the glass. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 5%, more preferably 3%, and most preferably 2%.
Rn ₂ The O component (one or more selected from Rn = Li, Na, K, and Cs) is also an optionally added component that has the effect of lowering the melting point of the glass and improving the meltability of the glass. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 5%, more preferably 3%, and most preferably 2%.
ZrO ₂ , SnO ₂ , Nb ₂ O ₅ And Ta ₂ O ₅ One or more of each component is an optionally added component that has the effect of increasing the density of the glass, but if added in a large amount, the melting property of the glass becomes poor and the tendency to not vitrify becomes strong. The upper limit of the total content of one or more of these components is preferably 8%, more preferably 6%, and most preferably 5%.
As ₂ O ₃ Ingredient or Sb ₂ O ₃ The component is Tb that serves as a clarifier during glass melting or the above-described emission center. ³⁺ And Ce ³⁺ Ions can be added because they also serve as a reducing agent for maintaining the state, but the total amount of one or two of these is sufficient to be 5% or less. The upper limit of the more preferable total amount is 3%, and the upper limit of the most preferable total amount is 2%.
The glass of composition 10 to composition 19 of the present invention cannot be expressed directly by mass% because the composition is represented by mol%, but the composition represented by mass% of the present invention. In order to achieve the effects of the respective components described for the first to tenth glasses in which the fluorescent glass or scintillator glass from 10 to 19 is expressed in mol%, the content of each component by mass% display is The range is roughly as follows.
SiO ₂ Ingredient or B ₂ O ₃ The component is a glass-forming oxide and is an essential component for obtaining a stable glass. However, when either one is introduced into the glass alone, Ln ₂ O ₃ Since it is difficult to incorporate a component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) into glass at a high concentration, both components must be introduced.
To obtain a stable glass, SiO ₂ The lower limit of the component content is preferably 2% by mass, more preferably 3% by mass, most preferably 3.5% by mass, B ₂ O ₃ The lower limit of the component content is preferably 2%, more preferably 3.5% by mass, most preferably 4.5% by mass, and the lower limit of the total content of both components is 5%. It is preferable to set it as mass%, It is more preferable to set it as 7.5 mass%, It is most preferable to set it as 1.0 mass%. Also, in order for the glass to reach the desired high density, SiO ₂ The upper limit of the component content is preferably 40% by mass, more preferably 30% by mass, most preferably 20% by mass, and B ₂ O ₃ The upper limit of the components is preferably 40% by mass, more preferably 30% by mass, most preferably 20% by mass, and the upper limit of the total content of both components is 45% by mass. preferable. In particular, if the upper limit of the content of both components is 40% by mass, Ln ₂ O ₃ The component can be contained in an amount of 35% by mass or more, and a higher density glass is easily obtained.
Ga ₂ O ₃ Component or GeO ₂ The components are effective in improving the density of the glass, lowering the melting point of the glass, and improving the stability and meltability of the glass. ₂ O ₃ One of them is indispensable for obtaining the glass of the present invention because it greatly contributes to an increase in the component content.
In order to sufficiently obtain the above effect, the lower limit of the content in the case of introducing only one of these or the total content of the two types is preferably 0.5% by mass, and preferably 3% by mass. More preferably, it is most preferable to set it as 5 mass%.
In order to obtain good meltability of glass and to facilitate vitrification, Ga ₂ O ₃ The upper limit of the component content is preferably 40% by mass, more preferably 34% by mass, and most preferably 28% by mass. GeO ₂ The larger the amount of the component, the more advantageous it is for glass formation. However, since it is a very expensive component, the upper limit of its content is preferably 40% by mass, more preferably 30% by mass, Most preferably, it is made into the mass%.
The above two components can be introduced alone into the glass, but it is more effective to introduce the two components together. The upper limit of the content of one or two of these two components is preferably 40% by mass, more preferably 34% by mass, and most preferably 28% by mass.
Ga ₂ O ₃ Components and GeO ₂ One or two of the ingredients are Al ₂ O ₃ Can be replaced with ingredients. However, if completely replaced, the meltability and stability of the glass deteriorate, so partial replacement is more preferable. Specifically, Ga ₂ O ₃ Components and GeO ₂ Al to replace one or two of the ingredients ₂ O ₃ Change the substitution rate of the component to Ga before substitution ₂ O ₃ Components and GeO ₂ It is preferable to suppress to 91% by mass or less based on the total content of one or two components. A more preferred substitution rate is 83% by mass or less, and a most preferred substitution rate is 76% by mass or less.
P ₂ O ₅ The component is an optional component having an effect of improving the stability of the glass. Especially Tb which is a luminescent ion ³⁺ Or Ce ³⁺ It is desirable to add it because it is advantageous to maintain the state in that state. In order to obtain these effects, the lower limit of the content is more preferably 0.4% by mass, and most preferably 0.7% by mass. The upper limit with preferable content is 8 mass%, and when the value is exceeded, stability of glass will worsen on the contrary. A more preferred upper limit is 7% by mass, and a most preferred upper limit is 6% by mass.
Ln ₂ O ₃ The component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) greatly contributes to an increase in the density of the glass and is an essential component for achieving the object of the present invention. Even if only one of these components is contained, a desired glass can be obtained. However, if two or more of these components are contained, the meltability and stability of the glass are further improved. In order to obtain a glass having a high density, the lower limit of the total content of one or more of these components is preferably 30% by mass, more preferably 35% by mass, and 40% by mass. % Is most preferable. However, in order to maintain good meltability and stability for vitrification, the upper limit of the total content is preferably 80% by mass, more preferably 77% by mass, and 74% by mass. Most preferably.
Of these ingredients, Lu ₂ O ₃ Is particularly important because it has an extremely high effect of increasing the density of the glass. ₂ O ₃ Lu for the total content of ingredients ₂ O ₃ Most preferably, the content of the components is 5% by mass or more.
AlF ₃ Component or GaF ₃ The component lowers the melting point of the glass and is effective in improving the meltability and stability of the glass. ₂ O ₃ It is most effective to add in a form that replaces a part of. However, to improve the stability of the glass, AlF ₃ Component or GaF ₃ The substitution rate of components is Ga before substitution. ₂ O ₃ More preferably, it is 86 mass% or less with respect to content of a component, and it is most preferable to set it as 73 mass% or less.
LnF ₃ The component (one or more selected from Ln = Y, La, Dy, Gd, and Lu) is effective in lowering the melting point of the glass and improving the melting property and stability of the glass. ₂ O ₃ It is most effective to add in the form of replacing some of the components. However, LnF ₃ The substitution rate of the component is Ln before substitution. ₂ O ₃ It should be at most 47% by mass based on the total content of the components. If this value is exceeded, the stability of the glass will be further reduced. More preferred LnF ₃ The substitution rate of the component is Ln before substitution ₂ O ₃ It is 42 mass% or less with respect to the total of content of a component, and 37 mass% or less is the most preferable.
The introduction of fluoride not only has the above effect but also Tb which is a luminescent ion described later. ³⁺ Or Ce ³⁺ Since the effect as a reducing agent is exhibited in order to maintain the state in this state, there is also an effect that contributes to the improvement of the light emission characteristics.
X ₂ O ₃ The component (one or more selected from X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, and Mn) plays the role of a luminescent center and is an indispensable component for realizing the scintillation characteristics of the present invention. Since these components have different emission wavelengths, scintillators having various wavelengths can be realized by introducing them alone into glass. Furthermore, when two types (for example, Tb and Ce ions) are introduced in a combination, energy transfer between ions occurs, and light emission may be greatly amplified.
In order to obtain sufficient emission intensity, the lower limit of the total content of one or more of these components is preferably 0.005% by mass, more preferably 0.07% by mass, It is most preferable to set it as 0.03 mass%. However, since emission intensity is drastically reduced when concentration quenching occurs, the upper limit of the content is preferably less than 30% by mass, more preferably 27% by mass, and most preferably 24% by mass. .
Among these components, Tb ₂ O ₃ , Eu ₂ O ₃ , Ce ₂ O ₃ Since the component has a particularly good effect as the emission center, Pr ₂ O ₃ , Nd ₂ O ₃ , Yb ₂ O ₃ , Cr ₂ O ₃ , Mn ₂ O ₃ X not included ₂ O ₃ All ingredients are Tb ₂ O ₃ , Eu ₂ O ₃ , Ce ₂ O ₃ Of these, it is particularly preferable to use one or more of them.
In the case of Tb and Ce, Tb ³⁺ And Tb ⁴⁺ , Ce ³⁺ And Ce ⁴⁺ The two types of states can exist, but it is Tb that emits light ³⁺ Or Ce ³⁺ Therefore, it is desirable to use a reducing agent or to produce the glass in a slightly reducing atmosphere. These luminescent ions may be introduced into the glass in the form of fluoride or chloride in addition to the oxide form as described above.
X above ₂ O ₃ All or part of the components (one or more selected from X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, Mn) ₃ It is also possible to introduce luminescent ions into the glass by replacing the components. However, to improve the stability of the glass, XF ₃ The substitution rate of the component is X before substitution ₂ O ₃ It is more preferable to set it as 84 mass% or less with respect to the sum total of content of a component, and it is most preferable to set it as 70 mass% or less.
In order to enhance the emission of the above-mentioned luminescent ions, Sm is used as a sensitizer. ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Bi ₂ O ₃ Ingredients can be added. However, the maximum addition amount should be suppressed to 10% by mass or less, and if the addition exceeds that value, light emission is weakened.
The RO component (one or more selected from R = Mg, Ca, Sr, Ba, Zn) is a component that can be optionally added and has the effect of lowering the melting point of the glass and improving the meltability of the glass. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 5% by mass, more preferably 3% by mass, and most preferably 2% by mass.
Rn ₂ The O component (one or more selected from Rn = Li, Na, K, and Cs) is also an optionally added component that has the effect of lowering the melting point of the glass and improving the meltability of the glass. However, in order to maintain good stability of the glass, the upper limit of the total content is preferably 5% by mass, more preferably 3% by mass, and most preferably 2% by mass.
ZrO ₂ , SnO ₂ , Nb ₂ O ₅ And Ta ₂ O ₅ One or more of each component is an optionally added component that has the effect of increasing the density of the glass, but if added in a large amount, the melting property of the glass becomes poor and the tendency to not vitrify becomes strong. The total content of one or more of these components is preferably 5% by mass, more preferably 3% by mass, and most preferably 2% by mass.
As ₂ O ₃ Ingredient or Sb ₂ O ₃ The component is Tb that serves as a clarifier during glass melting or the above-described emission center. ³⁺ And Ce ³⁺ The ions can be added because they also serve as a reducing agent for maintaining the state, but the total amount of one or two of these is sufficient to be 5% by mass or less. The upper limit of the more preferable total amount is 3% by mass, and the upper limit of the most preferable total amount is 2% by mass.
Next, the density of the glass of Configuration 1 to Configuration 22 of the present invention will be described. The glass of the present invention is 3.0 g / cm ³ Although having the above high density, in order for the glass of the present invention to have an absorptivity of radiation necessary as a scintillator, the density of the glass is preferably 4.0 g / cm 3 or more, and 4.2 g / cm 3. ³ More preferably, it is more preferably 4.5 g / cm 3 or more.
In the glasses having the constitutions 1 to 22 according to the present invention, good scintillator characteristics cannot be obtained even when the Ti, V, Fe, Co, and Ni components are introduced into the glass. Since the glass of the present invention has the above-mentioned properties and stability as a glass with the constitution of other components contained, it is preferable that these components are not substantially contained.
In addition, the Pb component has a tendency to refrain from specifications as a harmful chemical substance in recent years, and environmental measures are required not only for the glass manufacturing process but also for the processing process and disposal after commercialization. It is preferable not to contain.
In addition, in this specification, it does not contain substantially means not to contain it artificially except when mixed as an impurity.
Next, the light emission decay time of the fluorescent glass or scintillator glass according to configurations 1 to 22 of the present invention will be described. The decay time refers to the time from when the strongest emission peak wavelength is monitored and the emission intensity becomes 1 / e (36.8%) after the excitation is stopped. The decay time of the fluorescent glass or scintillator glass of the present invention is 5 ms or less. Particularly when the Ce component is contained in the glass, a decay time of 1 μs or less can be realized.
The high-density fluorescent glass or scintillator glass of the present invention can be produced by the following method. That is, after a predetermined amount of each starting material is weighed and mixed uniformly, it is put in a platinum crucible, a quartz crucible, an alumina crucible or the like, and 1300 to 1580 ° C., more preferably 1300 to 1550 ° C. in an electric furnace. Dissolve for 10 hours. Thereafter, the glass solution is poured into a mold and molded into a predetermined shape to obtain glass. Even if glass is made in air, many Tb ions ³⁺ However, it is more preferable to use a reducing agent or make it in a weak reducing atmosphere. In the case of glass containing Ce, ions Ce that emit light when produced in air. ³⁺ Ion Ce that does not emit light ⁴⁺ Therefore, it is desirable to use a reducing agent or make it in a reducing atmosphere.

［実施例１０］
原料としてＨ_３ＢＯ_３、ＳｉＯ_２、ＮＨ_４Ｈ_２ＰＯ_４、Ｇａ_２Ｏ_３、Ｇｄ_２Ｏ_３、Ｔｂ_４Ｏ_７を使用した。これらをｍｏｌ％で１５ＳｉＯ_２−２５Ｂ_２Ｏ_３−５Ｐ_２Ｏ_５−１５Ｇａ_２Ｏ_３−２８Ｇｄ_２Ｏ_３−１０ＧｄＦ_３−２Ｔｂ_２Ｏ_３という組成になるように秤量し、均一に混合した後、白金坩堝に入れて１５００℃で２時間溶解した。その後、ガラス溶液を予め温めた鉄板にキャストし、板状のガラスを作製する。こうして得られたガラスを切断し、サイズ２ｍｍ×２ｍｍ×２ｍｍ研磨した後、諸物性の測定に供した。
このガラスは密度が５．７９４ｇ／ｃｍ３で、図１に示すように紫外域から近赤外域にわたり高い透明性を有している。
［実施例１１〜２４］
実施例１０と類似の方法で実施例１１〜２４のガラスを作製した。
表２、表３にこれらのガラスの組成、密度を示す。どのガラスも高い密度を有することがわかる。更に、これらのガラスにＸ線を当てるとシンチレーションすることが肉眼で確認された。図３と４にＴｂ^３＋を含んだ本発明のガラスとシンチレータ単結晶Ｂｉ_４Ｇｅ_３Ｏ_１２（ＢＧＯ）の励起と発光スペクトルを示す。本発明のガラスはより効率よく発光することが明らかである。

Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to these examples.
[Example 1]
% By mass _{35.1SiO 2 -13.1BaO-28Gd 2 O 3} -3.3MgO-4.2Li 2 O-3.3K 2 O-2.0Ga 2 O 3 -2.4Al 2 O 3 -8.6Tb _After weighing to ₂ O ₃ and mixing uniformly, it was melted at 1400 ° C. for 1 hour and 40 minutes using a quartz crucible. Thereafter, the glass solution is cast on a preheated iron plate to produce a plate-like glass. Both surfaces were polished so that the glass thus obtained had a size of 2 × 2 × 2 mm, and then subjected to measurement of various physical properties. This glass has a density of 3.85 g / cm ³ , and green light emission is clearly observed with the naked eye when X-rays are applied.
[Examples 2 to 9]
Glasses of Examples 2 to 9 were produced using a quartz or platinum crucible under melting conditions similar to those of Example 1.
[Comparative example]
Further, Comparative Examples 1 and 2 were produced in the same manner as in the above-described Examples.
Table 1 shows the glass composition and density expressed in mass% of the examples and comparative examples. According to Table 1, it can be seen that the glass of the example has a higher density.
Moreover, the emission spectrum of Example 1 and a comparative example containing Tb ion is shown in FIG. Compared with the comparative example, the emission intensity of the example was increased by 1.4 times or more.

[Example 10]
H ₃ BO ₃ , SiO ₂ , NH ₄ H ₂ PO ₄ , Ga ₂ O ₃ , Gd ₂ O ₃ , and Tb ₄ O ₇ were used as raw materials. These were weighed so as to obtain the composition of _{15SiO 2 -25B 2 O 3 -5P 2} O 5 -15Ga 2 O 3 -28Gd 2 O 3 -10GdF 3 -2Tb 2 O 3 in mol%, were uniformly mixed, It put into the platinum crucible and melt | dissolved at 1500 degreeC for 2 hours. Thereafter, the glass solution is cast on a preheated iron plate to produce a plate-like glass. The glass thus obtained was cut, polished 2 mm × 2 mm × 2 mm in size, and then subjected to measurement of various physical properties.
This glass has a density of 5.794 g / cm 3 and has high transparency from the ultraviolet region to the near infrared region as shown in FIG.
[Examples 11 to 24]
Glasses of Examples 11 to 24 were produced by a method similar to Example 10.
Tables 2 and 3 show the composition and density of these glasses. It can be seen that every glass has a high density. Furthermore, it was confirmed with the naked eye that scintillation occurred when X-rays were applied to these glasses. FIGS. 3 and 4 show excitation and emission spectra of the glass of the present invention containing Tb ³⁺ and a scintillator single crystal Bi ₄ Ge ₃ O ₁₂ (BGO). It is clear that the glass of the present invention emits light more efficiently.

  The fluorescent glass or scintillator glass according to the present invention has a high density, has a high light transparency from the ultraviolet region to the near infrared region, and uses scintillation by excitation of X-rays. Applicable to devices. Further, it has a high density and a high absorption rate of radiation such as X-rays, and is suitable as a radiation shielding material.

Claims (24)

The Ln ₂ O ₃ component is contained in an amount of more than 10.2% by mass%, provided that at least one selected from Ln = Lu, Gd, Y, Dy, La, and the density is 3.0 g / cm ³ or more. Fluorescent glass characterized by certain things. It contains more than 2.8% of Ln ₂ O ₃ component in mol%, provided that at least one selected from Ln = Lu, Gd, Y, Dy, La, and the density is 3.0 g / cm ³ or more. Fluorescent glass characterized by certain things. % By mass
SiO ₂ 5-50%, and Ga ₂ O ₃ + GeO ₂ 1-25%, and BaO 10-40%, and Gd ₂ O ₃ + Lu ₂ O ₃ 16-45%, and Tb ₂ O ₃ + Ce ₂ O ₃ 0 .01-20%,
And
B ₂ O ₃ 0~45%, and / or _P 2 _O 5 0~10%, and / or _{Y 2 O 3 + La 2 O} 3 0~20%, and / or RO 0%
However, R = Mg, Ca, Sr, 2 or more types selected from Zn, and / or Rn ₂ O 0-15%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%, and / or _X 2 _O 3 0-5%
However, X = Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb, or one or more types selected from Mn,
Each of these components is contained, The fluorescent glass of Claim 1 characterized by the above-mentioned. % By mass
SiO ₂ 5 to 50%, and _Ga 2 _O 3 _1~25%, and BaO 10 to 40%, and _{Gd 2 O 3 + Lu 2 O} 3 16~45%, and _{Tb 2 O 3 + Ce 2 O} 3 0.01 ~ 20%
And
B ₂ O ₃ 0~45%, and / or _P 2 _O 5 0~10%, and / or _{Y 2 O 3 + La 2 O} 3 0~20%, and / or RO 0%
However, at least one selected from R = Mg, Ca, Sr, Zn and / or Rn ₂ O 0-15%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%, and / or _X 2 _O 3 0-5%
However, X = Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb, or one or more types selected from Mn,
Each of these components is contained, The fluorescent glass of Claim 1 characterized by the above-mentioned. % By mass
SiO ₂ 5-50%, and GeO ₂ 1-25%, and BaO 10-40%, and Gd ₂ O ₃ + Lu ₂ O ₃ 16-45%, and Tb ₂ O ₃ + Ce ₂ O ₃ 0.01-20 %,
And
B ₂ O ₃ 0~45%, and / or _P 2 _O 5 0~10%, and / or _{Y 2 O 3 + La 2 O} 3 0~20%, and / or RO 0%
However, at least one selected from R = Mg, Ca, Sr, Zn and / or Rn ₂ O 0-15%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%, and / or _X 2 _O 3 0-5%
However, X = Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb, or one or more types selected from Mn,
Each of these components is contained, The fluorescent glass of Claim 1 characterized by the above-mentioned. By mass%, fluorescent glass according to any one of claims 1, 3, 4 or 5, characterized in that it contains from 0.5 to 8% of _P 2 _{O 5} component. 7. The fluorescent glass according to claim 3, wherein a part of the Ga ₂ O ₃ component is replaced with an Al ₂ O ₃ component. 8. The fluorescent glass according to claim 3, wherein a part of the Ga ₂ O ₃ component is replaced with an AlF ₃ component or a GaF ₃ component. Ln ₂ O ₃ component in glass, where Ln = Y, La, Dy, Gd, or Lu is selected from one or more selected from LnF ₃ component consisting of the same cation component, and the substitution rate is substituted The fluorescent glass according to claim 1, which is 60% by mass or less based on the content of the previous Ln ₂ O ₃ component. _SiO 2 1 to 60% by mol%, and _B 2 _O 3 1~60%
_{However, SiO 2 + B 2 O 3} 25~65%, and _{GeO 2 + Ga 2 O 3 1~40} %, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, and La, and X ₂ O ₃ 0.01 to 15%
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%
Each of these components is contained, The fluorescent glass of Claim 2 characterized by the above-mentioned. _SiO 2 1 to 60% by mol%, and _B 2 _O 3 1~60%
_{However, SiO 2 + B 2 O 3} 25~60%, and _{GeO 2 + Ga 2 O 3 1~40} %, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, and La, and X ₂ O ₃ 0.01 to 15%
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%
Each of these components is contained, The fluorescent glass of Claim 2 characterized by the above-mentioned. _SiO 2 1 to 60% by mol%, and _B 2 _O 3 1~60%
_{However, SiO 2 + B 2 O 3} 25~60%, and _Ga 2 _O 3 _1~40%, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, and La, and X ₂ O ₃ 0.01 to 15%
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, Rn = Li, Na, K , one or more selected from among Cs, an / or _{ZrO 2 + SnO 2 + Nb 2} O 5 + Ta 2 O 5 0~8% and / or _{As 2 O 3 + Sb 2 O} 3 0 ~ 5%
Each of these components is contained, The fluorescent glass of Claim 2 characterized by the above-mentioned. _SiO 2 1 to 60% by mol%, and _B 2 _O 3 1~60%
_{However, SiO 2 + B 2 O 3} 25~60%, and _GeO 2 1 to 40%, and _Ln 2 _O 3 _16~45%
However, at least one selected from Ln = Lu, Gd, Y, Dy, and La, and X ₂ O ₃ 0.01 to 15%
However, X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, one or more selected from Mn,
And
P ₂ O ₅ 0-10% and / or RO 0-5%
However, R = Mg, Ca, Sr, Ba, one or more selected from Zn, and / or Rn ₂ O 0 to 5%
However, one or more types selected from Rn = Li, Na, K, and Cs, and / or ZrO ₂ + SnO ₂ + Nb ₂ O ₅ + Ta ₂ O ₅ 0-8%, and / or As ₂ O ₃ + Sb ₂ O ₃ 0-5%
Each of these components is contained, The fluorescent glass of Claim 2 characterized by the above-mentioned. The fluorescent glass according to claim 2, wherein the fluorescent glass contains 0.5 to 8% of P ₂ O ₅ component in mol%. The fluorescent glass according to claim 10, wherein a part of one or two of the Ga ₂ O ₃ component and the GeO ₂ component is replaced with an Al ₂ O ₃ component. The fluorescent glass according to claim 10, wherein a part of Ga ₂ O ₃ is replaced with GaF ₃ or AlF ₃ . Ln ₂ O ₃ component, wherein one or more selected from Ln = Y, La, Dy, Gd, and Lu are replaced with LnF ₃ component, and the substitution rate of the Ln ₂ O ₃ component before substitution is characterized by It is 60 mol% or less with respect to the sum total of content, The fluorescent glass in any one of Claim 2 or 10-16. The X ₂ O ₃ component, wherein X = Tb, Eu, Pr, Nd, Ce, Yb, Cr, or Mn is partially or entirely replaced with an XF ₃ component. The fluorescent glass in any one of 10-17. The fluorescent glass according to claim 2, wherein the density is 4.0 g / cm ³ or more. The fluorescent glass according to any one of claims 1 to 19, wherein the decay time is 5 ms or less. 21. The fluorescent glass according to claim 1, which contains a Ce component and has a decay time of 1 μs or less. The fluorescent glass according to any one of claims 1 to 21, which is used as a scintillator. A radiation measuring apparatus using the fluorescent glass according to claim 1. A CT apparatus using the fluorescent glass according to claim 1.

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