JP2014221705A - Glass ceramic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent glass ceramic having a stronger emission peak in a desired wavelength range due to excitation by ultraviolet light or visible light.SOLUTION: There is provided a glass ceramic containing ABO:αF crystals (wherein, A is one or more selected from Y, Gd, Tb, Dy, Yb and Lu; B is Al and/or Ga; a combination of α and β is one or more selected from Eu, Eu, Ce, Mn, Mn, Sn, Cu, Bi, Pband Cr.

Description

  The present invention relates to glass ceramics.

  When a substance receives the energy of an electromagnetic wave such as an electron beam or ultraviolet light from the outside and is excited to return to the ground state, light that emits the received energy as light of a specific wavelength is called fluorescence, and the substance has such characteristics Is called a phosphor. The wavelength of light to be absorbed and the wavelength of emitted fluorescence differ depending on the type of phosphor, and a wide range of applications are expected for optical amplifiers, lasers, lighting, display light emitting elements, and the like. In particular, as the development of short-wavelength LEDs progresses in recent years, light-emitting elements that combine LED elements and phosphors that emit light by being excited by ultraviolet light or visible light from the LED elements have attracted attention, and are efficient with less power. Its use is expanding as a new light source that drives well. In such a situation, it is necessary to develop a phosphor having a long lifetime and high emission intensity.

  As such a phosphor, a phosphor in which Ce is doped into a YAG-based oxide is known. Since this phosphor emits yellow fluorescence when excited by blue light, a light source of white light can be realized by mixing two light emitted from the LED element and the phosphor.

  And the glass ceramics represented by patent documents 1-3 are known as glass ceramics which precipitated such fluorescent substance as a crystal phase. By depositing such a phosphor on glass ceramics, deterioration due to light and heat generated from the LED element is suppressed, and a uniform distribution state is realized to reduce unevenness in light emission.

JP 2009-268681 A JP 2007-031196 A JP 2006-117511 A

  However, in the glass ceramics of Patent Documents 1 to 3, since the intensity of the emission peak in the wavelength range of 500 to 600 nm is not yet sufficient, it is difficult to obtain a light-emitting element having a color tone adjusted when mixed with excitation light. Met.

  An object of the present invention is to obtain a fluorescent glass ceramic in which an emission peak appears more strongly in a desired wavelength range by excitation with ultraviolet light or visible light.

As a result of intensive studies and research in order to solve the above problems, the inventors of the present invention are strong by including an F component and a component that becomes a luminescent center in the composition of glass ceramics capable of depositing garnet crystals. The inventors have found that a large amount of A ₃ B ₅ O ₁₂ : α ^{β +} F crystal in which a light emission peak appears is precipitated on glass ceramics, and have completed the present invention.
Specifically, the present invention provides the following.

(1) A ₃ B ₅ O ₁₂ : α ^{β +} F crystal (A is one or more selected from Y, Gd, Tb, Dy, Yb, and Lu, B is Al or / and Ga, α and β Is a glass ceramic containing at least one selected from Eu ³⁺ , Eu ²⁺ , Ce ³⁺ , Mn ⁴⁺ , Mn ²⁺ , Sn ²⁺ , Cu ²⁺ , Bi ³⁺ , Pb ²⁺ and Cr ³⁺ ).

  (2) The glass ceramic according to (1), which has an emission peak in a range of 500 to 600 nm when light having a wavelength of 460 nm is incident.

(3) mol% on oxide basis,
Al ₂ O ₃ + Ga ₂ O ₃ is 20 to 50%,
10 to 50% of Ln ₂ O ₃ (Ln represents at least one selected from Y, Gd, Tb, Dy, Yb, and Lu),
Eu ₂ O ₃ + CeO ₂ + MnO ₂ + SnO ₂ + CuO + Bi ₂ O ₃ + PbO + Cr ₂ O ₃ is 0.1 to 10%
Contains,
The glass ceramic according to (1) or (2), which contains an F component in excess of 0% by mole% based on the total moles of oxides.

(4) mol% on oxide basis,
Al ₂ O ₃ component 15.0-50.0%
Ga ₂ O ₃ component from 0 to 20.0%
Y ₂ O ₃ component 10.0-50.0%
Gd ₂ O ₃ component 0 to 20.0%
Dy ₂ O ₃ component 0 to 10.0%
Yb ₂ O ₃ component 0 to 10.0%
Lu ₂ O ₃ component 0 to 10.0%
The glass ceramic according to any one of (1) to (3).

(5) The glass ceramic according to any one of (1) to (4), which contains 20.0 to 60.0% of SiO ₂ component + GeO ₂ component in mol% based on oxide.

(6) mol% on oxide basis,
SiO ₂ component 10.0-60.0%
GeO ₂ component 0-20.0%
The glass ceramic according to any one of (1) to (5).

(7) The glass ceramic according to any one of (1) to (6), wherein a molar sum (TiO ₂ + ZrO ₂ ) is 10.0% or less.

(8) mol% on oxide basis,
TiO ₂ component 0 to 10.0%
ZrO ₂ component 0 to 10.0%
The glass ceramic according to any one of (1) to (7).

  (9) The molar sum of the RO component (wherein R is one or more selected from the group consisting of Mg, Ca, Sr, Ba and Zn) is 20.0% or less on the oxide basis (1) To (8).

(10) mol% on oxide basis,
MgO component 0 to 15.0%
CaO component 0 to 15.0%
SrO component 0 to 15.0%
BaO component 0 to 15.0%
ZnO component 0 to 15.0%
The glass ceramic according to any one of (1) to (9).

(11) mol% on oxide basis,
Li ₂ O component 0 to 20.0%
Na ₂ O component 0 to 20.0%
K ₂ O component 0 to 20.0%
The glass ceramic according to any one of (1) to (10).

(12) On the oxide basis, the molar sum of the Rn ₂ O component (wherein R is one or more selected from the group consisting of Li, Na and K) is 20.0% or less (1) to ( The glass ceramic according to any one of 11).

(13) mol% on oxide basis,
B ₂ O ₃ component 0 to 30.0%
P ₂ O ₅ component 0 to 10.0%
Nb ₂ O ₅ component 0 to 10.0%
Ta ₂ O ₅ component 0 to 10.0%
WO ₃ components 0 to 10.0%
TeO ₂ component 0 to 10.0%
Sb ₂ O ₃ component 0-1.0%
The glass ceramic according to any one of (1) to (12).

(14) The glass ceramic according to any one of (1) to (13), which contains AlF ₃ + GaF ₃ in an amount of mol% of the raw material composition of more than 0% and 20.0% or less.

  According to the present invention, it is possible to obtain a fluorescent glass ceramic in which a light emission peak appears more strongly in a desired wavelength range by excitation with ultraviolet light or visible light.

It is an XRD pattern about the glass ceramics of Example 6 and Comparative Example 1.

The glass ceramic of the present invention comprises an A ₃ B ₅ O ₁₂ : α ^{β +} F crystal (A is one or more selected from Y, Gd, Tb, Dy, Yb, and Lu, and B is Al or / and Ga. The combination of α and β contains at least one selected from Eu ³⁺ , Eu ²⁺ , Ce ³⁺ , Mn ⁴⁺ , Mn ²⁺ , Sn ²⁺ , Cu ²⁺ , Bi ³⁺ , Pb ²⁺ , and Cr ³⁺ . To do. A ₃ B ₅ O ₁₂ : α ^{β + in} which a strong emission peak appears by adding an F component and a component that becomes a light emission center to a glass ceramic composition capable of precipitating garnet crystals including YAG-based crystals. Many F crystals are deposited on the glass ceramic. For this reason, fluorescent glass ceramics in which a light emission peak appears more strongly in a desired wavelength range by excitation with ultraviolet light or visible light can be obtained.

  Hereinafter, embodiments of the optical glass of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. be able to. In addition, although description may be abbreviate | omitted suitably about the location where description overlaps, the meaning of invention is not limited.

[Composition of glass ceramics]
The composition range of each component constituting the glass ceramic of the present invention will be described below. Unless otherwise specified in the present specification, the content of each component is all expressed in mol% with respect to the total number of moles of the oxide conversion composition. Here, the “oxide equivalent composition” means that the oxides, composite salts, metal fluorides, etc. used as raw materials of the constituent components of the glass ceramic of the present invention are all decomposed during melting and changed to oxides. In addition, the total mole number of the generated oxide is 100 mol%, and the mole fraction of each component contained in the glass ceramic is described.

The Al ₂ O ₃ component and the Ga ₂ O ₃ component are essential components for forming a crystal phase composed of a garnet crystal, and glass (hereinafter, the original glass and glass ceramic are collectively referred to as “glass”). It is a component that can improve the stability of By increasing the stability of the glass, it becomes easy to control the crystallization rate and suppress the precipitation of an undesired crystal phase, so that more luminescent centers can be contained. In particular, by containing the Ga ₂ O ₃ component, the melting temperature of the glass can be greatly lowered, and garnet crystals can be more easily precipitated. Therefore, the total content of the Al ₂ O ₃ component and the Ga ₂ O ₃ component is preferably 20.0%, more preferably 25.0%, and even more preferably 30.0%.
On the other hand, by making the total content of the Al ₂ O ₃ component and the Ga ₂ O ₃ component 50.0% or less, it is possible to suppress a decrease in the meltability of the glass material and the stability of the glass due to the excessive content thereof. . Therefore, the total content of the Al ₂ O ₃ component and the Ga ₂ O ₃ component is preferably 50.0%, more preferably 45.0%, and even more preferably 40.0%.

Of these, the content of the Al ₂ O ₃ component is preferably 15.0%, more preferably 20.0%, in order to facilitate the formation of a crystal phase composed of garnet crystals and increase the stability of the glass. Preferably, the lower limit is 25.0%.
On the other hand, the content of the Al ₂ O ₃ component is preferably 50.0%, more preferably 45.0%, and even more preferably 40.0 in order to suppress a decrease in meltability of the glass raw material and stability of the glass. %, More preferably 37.0%.
Further, the content of the Ga ₂ O ₃ component is preferably 0.3%, more preferably in order to facilitate the formation of a crystal phase composed of garnet crystals, to lower the melting temperature of the glass, and to increase the stability of the glass. The lower limit may be 0.5%, more preferably 1.0%.
On the other hand, the content of the Ga ₂ O ₃ component is preferably 20.0%, more preferably 15.0%, and even more preferably 10.0% in order to suppress an increase in raw material cost.

Ln ₂ O ₃ component (wherein Ln represents at least one selected from Y, Gd, Tb, Dy, Yb, and Lu) is also an essential component for forming a crystal phase composed of garnet crystals It is. Therefore, the total content of the Ln ₂ O ₃ components is preferably 10.0%, more preferably 15.0%, and still more preferably 18.0%.
On the other hand, when the total content of the Ln ₂ O ₃ components is 50.0% or less, a decrease in the stability of the glass due to the excessive content thereof can be suppressed. Accordingly, the total content of the Ln ₂ O ₃ components is preferably 50.0%, more preferably 40.0%, still more preferably 30.0%, and even more preferably 25.0%.

Here, the content of the Y ₂ O ₃ component is preferably 10.0%, more preferably 15.0%, and even more preferably 18.0% from the viewpoint of easily forming a crystal phase composed of garnet crystals. The lower limit.
On the other hand, the content of the Y ₂ O ₃ component is preferably 50.0%, more preferably 40.0%, still more preferably 30.0%, and even more preferably 25 in order to suppress a decrease in the stability of the glass. 0.0% is the upper limit.
Further, from the same viewpoint, the content of the Gd ₂ O ₃ component is preferably 20.0% or less, more preferably less than 10.0%, and even more preferably less than 5.0%.
In addition, the content of each of the Dy ₂ O ₃ component, the Yb ₂ O ₃ component, and the Lu ₂ O ₃ component is preferably 10.0%, more preferably 8.0%, and even more preferably 5 from the same viewpoint. 0.0% is the upper limit.

Eu ₂ O ₃ component, CeO ₂ component, MnO ₂ component, SnO ₂ component, CuO component, Bi ₂ O ₃ component, PbO component and Cr ₂ O ₃ component play the role of emission center, and can be used in glass and crystallized glass. Since it imparts fluorescence characteristics, at least one of them is an essential component. In the glass ceramic of the present invention, even when more luminescent centers are contained, the stability of the glass is further improved, so that fluorescence by excitation light can be further enhanced. The total content of at least one of these components is preferably 0.1%, more preferably 0.2%, still more preferably 0.3%, and still more preferably 0.5%.
On the other hand, if the content of these components is too large, the fluorescence tends to be weak. Therefore, the total content of these components is preferably 10.0%, more preferably 5.0%, and still more preferably 3.0%.

Here, the Eu ₂ O ₃ component is in a divalent and trivalent state, the CeO ₂ component is in a trivalent state, the MnO ₂ component is in a divalent and tetravalent state, and the SnO ₂ component is in a divalent state. The CuO component is preferably contained in the glass in the divalent state, the Bi ₂ O ₃ component in the trivalent state, the PbO component in the divalent state, and the Cr ₂ O ₃ component in the trivalent state. . Thereby, since these components act as emission centers, glass ceramics having a stronger emission peak due to excitation of ultraviolet light or visible light can be obtained.
On the other hand, it is preferable to reduce the content of these components in a valence state other than those described above, and it is more preferable not to include them in a valence state other than those described above. Thereby, since the content of the component that does not act as the emission center is reduced, the metal ion α ^{β +} that acts as the emission center can be easily increased.

These components may be contained in a plurality of types from the viewpoint of adjusting the color tone of the fluorescence, but from the viewpoint of further enhancing the emission peak due to excitation of ultraviolet light or visible light, contain only one of them. Is preferred.
Among these, when the CeO ₂ component is contained, the crystal phase of the glass ceramics emits yellow fluorescence by blue light. Therefore, by mixing the blue light emitted from the LED element and the yellow light emitted from the crystal phase, the LED element Can be used as a light source of white light.

  These components are not limited to the oxide form as described above, and may be contained in the glass in the form of fluoride or chloride.

By containing more than 0% of the F component, there is an effect of lowering the melting temperature, contributing to improvement of the meltability and stability of the glass, and promoting the precipitation of a desired crystal phase. In addition, by dissolving in a desired crystal phase, there is a remarkable effect of adjusting the emission color or improving the emission efficiency. In particular, when a CeO ₂ component is contained, the luminous efficiency of Ce ³⁺ ions can be improved. Therefore, the content of the F component on an external basis with respect to the total number of moles of oxide is preferably more than 0%, more preferably more than 5.0%, still more preferably more than 10.0%, and still more preferably 13. Over 0%.
On the other hand, by setting the content of the F component to 50.0% or less, it is possible to suppress a decrease in glass stability and precipitation of an undesired crystal phase. Therefore, the content of the F component in an external ratio with respect to the total number of moles of the oxide is preferably 50.0%, more preferably 40.0%, still more preferably 30.0%, still more preferably 25.0. % Is the upper limit.
The F component can be contained in the glass using, for example, ZrF ₄ , AlF ₃ , NaF, CaF ₂ , K ₂ SiF ₆ , Na ₂ SiF ₆ , LaF ₃ or the like as a raw material.

  The content of the F component in this specification is based on the assumption that all of the cation components constituting the glass are made of oxides combined with oxygen that balances the charge, and the total number of moles of the glass made of these oxides. 100% represents the mole fraction of the F component (extra mol% relative to the total number of moles of oxide).

The SiO ₂ component and the GeO ₂ component are components that can be glass-forming oxides, and are important components for obtaining a glass that is stable and has good durability and weather resistance. Therefore, the total content of the SiO ₂ component and the GeO ₂ component is preferably 20.0%, more preferably 30.0%, and still more preferably 35.0%.
On the other hand, by making the total content of SiO ₂ component and GeO ₂ component below 60.0%, suppressed an increase in the melting temperature of the glass material. Accordingly, the total content of the SiO ₂ component and the GeO ₂ component is preferably 60.0%, more preferably 50.0%, and still more preferably 45.0%.

Here, the content of the SiO ₂ component is preferably 10.0%, more preferably 20.0%, still more preferably 30.0%, further preferably from the viewpoint of easily forming a crystal phase composed of garnet crystals. Has a lower limit of 35.0%.
On the other hand, the content of the SiO ₂ component is preferably 60.0%, more preferably 50.0%, and further preferably 45.0% in order to suppress an increase in the melting temperature of the glass raw material.
Further, the content of the GeO ₂ component is preferably 20.0% or less, more preferably less than 10.0%, and still more preferably less than 5.0% from the same viewpoint and from the viewpoint of being an expensive material. To do.

The TiO ₂ component and the ZrO ₂ component are optional components that can easily precipitate a crystal phase by playing the role of a nucleating agent when containing at least one kind in excess of 0%.
On the other hand, by making the total content of TiO ₂ component and the ZrO ₂ component to 10.0% or less, it is suppressed a decrease in stability of the glass. Therefore, the total content of the TiO ₂ component and the ZrO ₂ component is preferably 10.0%, more preferably 8.0%, still more preferably 5.0%, and even more preferably 3.0%.

Here, the content of each of the TiO ₂ component and the ZrO ₂ component is preferably 10.0%, more preferably 8.0%, and even more preferably 5.0%, from the viewpoint of suppressing a decrease in the stability of the glass. More preferably, the upper limit is 3.0%.

When the RO component (wherein R is one or more selected from the group consisting of Mg, Ca, Sr, Ba, Zn) contains at least one of more than 0%, the melting point of the glass raw material can be lowered, Moreover, it is an optional component that can improve the stability and luminous efficiency of glass.
On the other hand, the fall of stability of the glass by excessive inclusion of RO component can be suppressed by making the total content of RO component 20.0% or less. Therefore, the total content of RO components is preferably 20.0%, more preferably 15.0%, and still more preferably 8.0%.

  Here, the content of each of the MgO component, the CaO component, the SrO component, the BaO component and the ZnO component is preferably 15.0%, more preferably 10.0%, from the viewpoint of suppressing a decrease in the stability of the glass. More preferably, the upper limit is 8.0%, more preferably 5.0%.

When the Rn ₂ O component (wherein Rn is one or more selected from the group consisting of Li, Na, and K) contains at least one of more than 0%, the melting point of the glass raw material can be lowered, and It is an optional component that can improve the stability of glass.
On the other hand, by making the total content of Rn 2 _O components below 20.0%, it suppressed the reduction in luminous efficiency of the glass. Therefore, the total content of the Rn ₂ O component is preferably 20.0%, more preferably 15.0%, and still more preferably 8.0%.

Here, the content of each of the Li ₂ O component, the Na ₂ O component, and the K ₂ O component is preferably 20.0%, more preferably 15.0%, and even more preferably from the viewpoint of suppressing a decrease in luminous efficiency. The upper limit is 8.0%.

The B ₂ O ₃ component is an optional component that can lower the melting point of the glass raw material and improve the stability of the glass when it contains more than 0%.
On the other _hand, by setting the content of B 2 _{O 3} component below 30.0%, suppressed the reduction in luminous efficiency of the glass. Therefore, the content of the B ₂ O ₃ component is preferably 30.0% or less, more preferably 20.0% or less, still more preferably less than 10.0%, and even more preferably less than 5.0%.

The P ₂ O ₅ component is an optional component that can easily precipitate a crystal phase in the glass ceramic when it contains more than 0%.
On the other hand, when the content of P ₂ O ₅ component to 10.0% or less, is suppressed a decrease in stability of the glass. Therefore, the content of the P ₂ O ₅ component is preferably 10.0%, more preferably 8.0%, and still more preferably 5.0%.

Nb ₂ O ₅ component, Ta ₂ O ₅ component, WO ₃ component, and TeO ₂ component are optional components that can lower the melting point of the glass raw material and improve the stability of the glass when containing at least one kind exceeding 0%. It is an ingredient.
On the other hand, when the content of each of the Nb ₂ O ₅ component, the Ta ₂ O ₅ component, the WO ₃ component, and the TeO ₂ component is 10.0% or less, a decrease in the stability of the glass can be suppressed. Accordingly, the upper limit of the content of these components is preferably 10.0%, more preferably 8.0%, and still more preferably 5.0%.

The Sb ₂ O ₃ component is an optional component that can degas the molten glass when it contains more than 0%. In particular, when a CeO ₂ component is contained as the emission center, by acting as a reducing agent, the ratio of Ce ³⁺ contributing to fluorescence can be increased in the CeO ₂ component, while Ce ⁴⁺ not contributing to fluorescence can be increased. The ratio can be reduced.
On the other hand, if the amount of Sb ₂ O ₃ is too large, the energy of excitation light is absorbed by Sb ions, and the light emission efficiency is lowered. Therefore, the content of the Sb ₂ O ₃ component is preferably 1.0%, more preferably 0.7%, and still more preferably 0.5%.

<About ingredients that should not be included>
Next, components that should not be contained in the glass ceramic of the present invention and components that are not preferably contained will be described.

  If necessary, other components can be added to the glass ceramic of the present invention as long as the properties of the glass ceramic are not impaired.

  However, each component of Th, Cd, Tl, Os, Be, Se, and Hg has tended to be refrained from being used as a harmful chemical material in recent years. Environmental measures are required until disposal. Therefore, when importance is placed on the environmental impact, it is preferable not to substantially contain them except for inevitable mixing. As a result, the glass ceramics are substantially free of substances that pollute the environment. Therefore, the glass ceramics can be manufactured, processed, and discarded without taking any special environmental measures.

[Production method]
The glass ceramics of this invention are produced as follows, for example. That is, each starting material is weighed to a predetermined ratio and uniformly mixed, and the prepared glass material is put into a platinum crucible, quartz crucible or alumina crucible and melted at 1250 to 1600 ° C. for 1 to 20 hours, and then molten glass Is cast into a mold to obtain the original glass. Next, the original glass is heat-treated at a temperature 10 to 500 ° C. higher than the glass transition temperature for 1 to 24 hours to precipitate a crystal phase to obtain glass ceramics.

Here, it is preferable that AlF ₃ + GaF ₃ is contained in the glass raw material in an amount of more than 0% and 20.0% or less in terms of mol% of the raw material composition. Thereby, volatilization of fluorine is suppressed and the stability of the glass is improved, so that a desired crystal phase can be more easily precipitated. Therefore, the total amount of AlF ₃ and GaF ₃ contained in the glass raw material is mol% of the raw material composition, preferably more than 0%, more preferably more than 1.0%, still more preferably more than 2.0%. The total amount of AlF ₃ and GaF ₃ contained in the glass raw material is mol% of the raw material composition, preferably 20.0%, more preferably 15.0%, still more preferably 10.0%, still more preferably. The upper limit is 8.0%.

[Physical properties]
The glass ceramic of the present invention has an A ₃ B ₅ O ₁₂ : α ^{β +} F crystal phase (A is one or more selected from Y, Gd, Tb, Dy, Yb, and Lu, and B is Al or / and Ga. And the combination of α and β is at least one selected from Eu ³⁺ , Eu ²⁺ , Ce ³⁺ , Mn ⁴⁺ , Mn ²⁺ , Sn ²⁺ , Cu ²⁺ , Bi ³⁺ , Pb ²⁺ and Cr ³⁺ ). It has been deposited. Thereby, since a strong emission peak appears at a wavelength corresponding to each emission center, a fluorescent glass ceramic in which the emission peak appears more strongly in a desired wavelength range can be obtained.

Here, for example, when the CeO ₂ component is contained as the emission center, the A ₃ B ₅ O ₁₂ : Ce ³⁺ F crystal phase is precipitated as the crystal phase, so that the wavelength range is 500 to 600 nm, particularly the wavelength range is 500 to 540 nm. The intensity of the luminescence peak at can be increased.

  In the glass ceramics of the present invention, the crystallization rate, which is the abundance ratio of particles showing a crystal phase, with respect to the whole glass ceramics is preferably 1.0% or more and 95.0% or less by volume. When the crystallization rate is 1.0% or more, the glass ceramic can have good fluorescence characteristics. On the other hand, when the crystallization rate is 95.0% or less, the glass ceramic can obtain good mechanical strength. Therefore, the crystallization rate of the glass ceramic is preferably 1.0%, more preferably 5.0%, and most preferably 10.0%. The crystallization rate of the glass ceramic is preferably 95.0%, more preferably 90.0%, and most preferably 85.0%.

The glass ceramic of the present invention emits fluorescence having an emission peak in a desired wavelength range when light having a specific wavelength is incident. The wavelength of the incident light (excitation light) is a wavelength in the visible light or ultraviolet light region, and specifically, a wavelength in the range of 220 nm to 500 nm. On the other hand, the wavelength of the fluorescence emission peak is a wavelength mainly in the visible light region, specifically, a wavelength in the range of 410 nm to 700 nm.
In particular, when Ce ³⁺ is used as the emission center, it is preferable to have an emission peak in the wavelength range of 500 to 600 nm, more preferably in the wavelength range of 510 to 540 nm when light having a wavelength of 460 nm is incident. Thereby, since yellow or green fluorescence is emitted by excitation of blue light, a light source in which two lights emitted from the LED element and the phosphor are mixed, for example, a white light source can be realized.

  The glass ceramics of the present invention can emit light efficiently by excitation light as described above, by precipitating crystals in which the emission center is dissolved. Moreover, in the glass ceramic of this invention, it can be made easy to control the kind and crystallization rate of a crystal phase because stability of glass is improved. Moreover, the glass ceramic of this invention has the advantage that durability and a weather resistance can be improved by having a glass phase, and can be manufactured without requiring a special atmosphere. Due to these advantages, the glass ceramics of the present invention can be applied to various optical devices including light source applications such as light emitting elements.

  Table 1 shows the compositions of the glass ceramic molded articles of the examples (No. 1 to No. 6) and the comparative example (No. 1) of the present invention, the type of precipitated crystal phase, the wavelength of the emission peak, and the emission intensity. The following examples are merely for illustrative purposes and are not limited to these examples.

  For each of the examples and comparative examples, a raw material composed of oxide and fluoride having a purity of 99.99% or more was selected as a raw material for each component, and weighed and uniformly mixed so as to have the composition ratio shown in the table. After preparing the glass raw material, it is put into a platinum crucible, melted in an electric furnace at 1500-1600 ° C. for 1-20 hours according to the melting difficulty of the glass composition, then poured into a pre-warmed mold and gradually cooled. An original glass was produced. About the obtained original glass, glass ceramics were obtained by hold | maintaining for 24 hours with the crystallization temperature of 1300-1400 degreeC. About the obtained glass ceramic, both surfaces were grind | polished so that it might become a size of 30 mm x 20 mm x 2 mm, and various physical properties were measured.

  The types of precipitated crystal phases of the glass ceramics of Examples and Comparative Examples were identified with an X-ray diffractometer (manufactured by Philips, trade name: X'Pert-MPD).

  The emission peak wavelength and emission intensity of the glass ceramics of Examples and Comparative Examples are measured by using a spectrofluorometer (FP-750 manufactured by JASCO Corporation) and measuring an emission spectrum when light having a wavelength of 460 nm is incident. Was determined by The emission intensity is expressed as a relative value when the emission intensity of the glass ceramic of Comparative Example 1 is set to 100.

As shown in Table 1, as a crystal phase of the glass ceramic of the example, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce ³⁺ F crystal, Y ₃ Al ₅ O ₁₂ : Ce ³⁺ F crystal, etc. YAG-type crystals represented by the formula A ₃ B ₅ O ₁₂ : α ^{β +} F were precipitated. This is because, in the XRD pattern of the glass ceramic of Example (No. 6) shown in FIG. 1, a peak occurs in the incident angle (2θ) represented by “◯”, including the vicinity of the incident angle 2θ = 33 °. It is clear from that.
On the other hand, as a crystal phase of the glass ceramic body of the comparative example (No. 1), these YAG-based crystals were not included. This is because in the XRD pattern of the glass ceramic of the comparative example shown in FIG. 1, the incident angle (2θ) represented by “x”, which is partly different from the above “◯”, has the example (No. 6). It is clear from the fact that peaks occur at different intensity ratios.
For this reason, unlike the glass ceramic of the comparative example, it is guessed that the glass ceramic of the Example of this invention has a high fluorescence characteristic with excitation light.

In the glass ceramics of the examples, the emission peak when light having a wavelength of 460 nm was incident appeared in the range of 500 to 600 nm, more specifically in the range of 500 to 540 nm.
Moreover, the glass ceramics of the examples have a light emission intensity of 2.4 times or more that of the comparative example (No. 1).
That is, since strong yellow or green fluorescence is emitted by the excitation of blue light, it can be inferred that a light source in which two lights emitted from the LED element and the phosphor are mixed, for example, a white light source can be realized.

Therefore, it was confirmed that in the glass ceramic of the example of the present invention, the emission peak appears more strongly in the desired wavelength range by excitation with ultraviolet light or visible light. This is presumably because YAG-based crystals represented by the general formula A ₃ B ₅ O ₁₂ : α ^{β +} F are precipitated.

  Although the present invention has been described in detail for the purpose of illustration, this embodiment is only for the purpose of illustration, and many modifications can be made by those skilled in the art without departing from the spirit and scope of the present invention. Will be understood.

Claims (4)

A ₃ B ₅ O ₁₂ : α ^{β +} F crystal (A is one or more selected from Y, Gd, Tb, Dy, Yb, and Lu, B is Al or / and Ga, and the combination of α and β is Glass ceramics containing at least one selected from Eu ³⁺ , Eu ²⁺ , Ce ³⁺ , Mn ⁴⁺ , Mn ²⁺ , Sn ²⁺ , Cu ²⁺ , Bi ³⁺ , Pb ²⁺ and Cr ³⁺ ).   The glass ceramic according to claim 1, which has an emission peak in a range of 500 to 600 nm when light having a wavelength of 460 nm is incident. In mole percent on oxide basis,
Al ₂ O ₃ + Ga ₂ O ₃ is 20 to 50%,
10 to 50% of Ln ₂ O ₃ (Ln represents at least one selected from Y, Gd, Tb, Dy, Yb, and Lu),
Eu ₂ O ₃ + CeO ₂ + MnO ₂ + SnO ₂ + CuO + Bi ₂ O ₃ + PbO + Cr ₂ O ₃ is 0.1 to 10%
Contains,
3. The glass ceramic according to claim 1, wherein the glass ceramic contains an F component in excess of 0% in an externally divided mol% based on the total number of moles of oxide. The glass ceramic according to any one of claims 1 to 3, which contains 20.0 to 60.0% of a SiO ₂ component + a GeO ₂ component in mol% based on an oxide.

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