JP2018131380A - Phosphor-dispersed glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphor-dispersed glass in which the deactivation of a phosphor is suppressed.SOLUTION: Provided is a phosphor-dispersed glass in which phosphor grains are dispersed in a glass, in which the glass contains, in mass%, SiOof 1-40%, BOof 15-65%, ZnO of 1-50%, RO (the total of one or more selected from the group consisting of MgO, CaO, SrO, and BaO) of 0-40%, RO (the total of one or more selected from the group consisting of LiO, NaO, and KO) of 0-30%, and ZrOof 0-5% (where, the total of SiO+BO+ZnO+RO+RO+ZrOis 80% or more).SELECTED DRAWING: None

Description

  The present invention relates to a phosphor dispersion glass characterized in that a phosphor as a light emitting material is sealed in glass.

  In recent years, white LEDs have been developed as white light sources, and power-saving and high color rendering white LEDs are required. Currently, commercially available white LEDs have a configuration in which a blue GaN-based LED is used as a light source and a cerium-doped YAG oxide phosphor that emits yellow fluorescence is excited. The light from this light source and the fluorescence are mixed and appear to the human eye as pseudo white light.

  In the combination of this conventional blue LED and the cerium-doped YAG oxide phosphor, since there are few components of cyan (˜500 nm) and red (600 nm), white light (daylight color) with a high color temperature can be obtained. White light (bulb color) with a low color temperature cannot be obtained. Therefore, a white light source with high color rendering is realized by adding a plurality of phosphors to compensate for a short wavelength component such as red.

In recent years, nitride phosphors are known as high-efficiency red phosphors. For example, in Patent Document 1, a CaAlSiN ₃ phosphor powder activated with Eu has been produced, and evaporation of contained components during sintering is prevented. Therefore, it has been proposed to sinter the raw material at 1600 to 2000 ° C. under a high-pressure nitrogen atmosphere.

  In most cases, the phosphor for LED used for illumination is sealed with an epoxy resin, a silicone resin, or a fluororesin. However, it has been pointed out that the above members are susceptible to deterioration due to heat generation of elements, light and moisture in the environment, and have a short life. Due to long-term use, the resin deteriorates due to ultraviolet light or blue light emitted from the LED, causing problems such as discoloration and deterioration of light transmission characteristics.

  Accordingly, attention has been focused on glass having higher durability and higher water barrier property than resin as a member to be coated. For example, a low melting point oxide glass as shown in Patent Document 2 has been proposed.

  As described above, a highly weather-resistant LED can be realized by encapsulating the phosphor in the glass. However, when the phosphor is actually encapsulated in the glass, the mixture of the phosphor and the glass has a glass transition point. The temperature needs to be raised to the above temperature and sintered, and the phosphor may be deactivated by the heat at that time. In order to prevent deactivation when glass is used, the phosphor-dispersed glass described in Patent Document 3 and Patent Document 4 is used for the oxide phosphor, and Patent Document 5 is used for the oxynitride phosphor. Each phosphor-dispersed glass has been reported.

Japanese Patent No. 5045432 Japanese Patent Laid-Open No. 2008-19109 JP 2005-11933 A Japanese Patent Laid-Open No. 2008-19109 JP 2011-162398 A

Yeh CW et al. "Origin of thermal degradation of Sr (2-x) Si5N8: Eu (x) phosphors in air for light-emitting diodes," J. Am. Chem. Soc., 134, 14108-14117 (2012) .

  As described above, when glass is used as a material for sealing the phosphor, the phosphor may be deactivated by heat during sintering.

Further, it has been reported that when a nitride phosphor is heated in an environment where oxygen is present, the phosphor is deactivated (Non-Patent Document 1). Non-Patent Document 1 reports that Sr _2−x Si ₅ N ₈ : Eu ²⁺ phosphor is oxidized to trivalent divalent Eu when oxygen is present during heating. That is, when the nitride phosphor and glass containing oxygen are mixed and sintered, the light emission efficiency of the nitride phosphor may be significantly reduced.

  Accordingly, an object of the present invention is to obtain a phosphor-dispersed glass in which phosphor deactivation is suppressed.

  The inventors have confirmed that when the phosphor phosphor is mixed with glass containing oxygen and sintered, the resulting phosphor-dispersed glass becomes black or gray and the luminous efficiency is greatly impaired. From the above findings, it has been clarified that, when an oxide glass having a specific composition is used, the above deactivation can be suppressed even if it is mixed with a nitride phosphor powder and sintered. Further, further investigation shows that deactivation occurs due to the reaction between the components constituting the phosphor and the glass composition components, and when the oxide glass having the above composition range is used, the wavelength is 350 to 475 nm. It has been clarified that inactivation of the luminous efficiency can be suppressed regardless of the type of phosphor if the phosphor has excitation light.

Accordingly, the present invention is a phosphor-dispersed glass in which phosphor particles are dispersed in glass, and the glass is 1% to 40% of SiO ₂ , 15 to 65% of B ₂ O ₃ , ZnO by mass%. 1 to 50%, RO (total of at least one selected from the group consisting of MgO, CaO, SrO, and BaO) 0 to 40%, R ₂ O (Li ₂ O, Na ₂ O, and K ₂ O) A total of at least one selected from the group consisting of 0 to 30% and 0 to 5% of ZrO ₂ (however, SiO ₂ + B ₂ O ₃ + ZnO + RO + R ₂ O + ZrO ₂ is 80% or more) The phosphor-dispersed glass.

  In addition, “deactivation” in the present specification refers to the case where the obtained phosphor-dispersed glass is visually black or gray, or the internal quantum efficiency is less than 20%. It is not appropriate to use the phosphor-dispersed glass thus deactivated for the white LED.

  The phosphor-dispersed glass of the present invention can be obtained, for example, by preparing a glass powder material of the glass described above, mixing the glass powder material and the phosphor powder, and then sintering them.

  According to the present invention, it is possible to obtain a phosphor-dispersed glass in which phosphor deactivation is suppressed. The present invention is not limited to the type of phosphor as long as the phosphor has excitation light at a wavelength of 350 to 475 nm, and the nitride phosphor particles are sealed in the glass while suppressing the deactivation of the luminous efficiency. Therefore, it is possible to obtain a high color rendering white LED.

One of the preferred embodiments of the present invention is a phosphor-dispersed glass in which phosphor particles are dispersed in glass, and the glass contains 1 to 40% of SiO ₂ and B ₂ O ₃ by mass%. 15 to 65%, ZnO 1 to 50%, RO (total of at least one selected from the group consisting of MgO, CaO, SrO, and BaO) 0 to 40%, R ₂ O (Li ₂ O, Na ₂ O, and at least one total) of 0-30% is selected from the group consisting of _{K 2} O, containing ZrO ₂ 0 to 5% _{(however, SiO 2 + B 2 O 3} + ZnO + RO + R 2 O + ZrO 2 is 80% or more) It is a phosphor-dispersed glass characterized by being a thing.

  By using the glass having the specific composition shown above, the reaction between the glass and the phosphor can be suppressed, and the phosphor can be prevented from being deactivated. Moreover, said glass is a composition which suppressed the raise of the softening point, and it can suppress that a fluorescent substance deactivates with a heat | fever at the time of sintering.

  Hereinafter, the composition of the glass of the present invention will be described. In addition, "%" which shows content of the component contained in glass shows the mass%, and may be described as "%" below.

SiO ₂ is a glass forming component, and can coexist with B ₂ O ₃ , which is another glass forming component, to form a stable glass, and is contained in the range of 1 to 40%. If it exceeds 40%, the softening point of the glass rises, and formability and workability become difficult. Preferably it is 2 to 35% of range.

B ₂ O ₃ is a glass-forming component, facilitates glass melting, suppresses an excessive increase in the linear expansion coefficient of glass, and imparts moderate fluidity to glass during baking. It is made to contain in 15 to 65% of range in glass. If it is less than 15%, depending on the relationship with other components, the fluidity of the glass may be insufficient, and the sinterability may be impaired. On the other hand, if it exceeds 65%, the softening point of the glass rises, and the moldability and workability become difficult. Preferably it is 20 to 61% of range. Also, the upper limit value is more preferably 44% or less.

  ZnO lowers the softening point of the glass and adjusts the linear expansion coefficient to an appropriate range, and is contained in the glass in the range of 1 to 50%. If it exceeds 50%, the glass becomes unstable and devitrification tends to occur. More preferably, it is 3 to 45% of range.

In addition, the glass used in the present invention contains B ₂ O ₃ and ZnO in a total of 20 to 80%, adjusts the softening point and the thermal expansion coefficient, and contains other components so that the glass can be devitrified. It is preferable to do so. More preferably, it may be 30 to 78%. In particular, in order to suppress the deactivation of the phosphor, it is effective to prevent the phosphor from being damaged by heat. Therefore, while containing SiO ₂ which stabilizes the glass and raises the softening point, the RO component and R ₂ are contained. It is preferable to contain an O component to suppress an excessive increase in the softening point.

ZrO ₂ suppresses devitrification at the time of melting or sintering of the glass and improves the chemical durability of the glass, and is contained in the range of 0 to 5%. If it exceeds 5%, the stability of the glass is lowered. Preferably it is 1 to 3% of range.

  RO (total of at least one selected from the group consisting of MgO, CaO, SrO, and BaO) lowers the softening point of the glass and is contained in the glass in an amount of 0 to 40%. On the other hand, if it exceeds 40%, the thermal expansion coefficient of the glass may become too high. Preferably it is 37% or less of range. Moreover, it is good also considering a lower limit as 0.2 mass% or more preferably.

R ₂ O (total of at least one selected from the group consisting of Li ₂ O, Na ₂ O, and K ₂ O) lowers the softening point of the glass and adjusts the thermal expansion coefficient to an appropriate range. It is made to contain in 30% of range. On the other hand, if it exceeds 30%, the thermal expansion coefficient is excessively increased. Preferably it is 26% or less of range. Moreover, it is good also considering a lower limit as 0.2 mass% or more preferably.

The glass _adjusts the content of each component of the glass so that _{SiO 2 + B 2 O 3 +} ZnO + RO + R 2 O + ZrO 2 is 80 mass% or more. As long as the total of the above components is 80% by mass or more and the phosphor is not deactivated, an optional third component may be contained. Preferably it is the range of 84 mass% or more. Moreover, an upper limit is good also as 100 mass%, More preferably, it is good also as 98 mass% or less.

One preferred embodiment of the present invention, the phosphor dispersion glass, the glass is, in mass%, the _{SiO 2 1~20%, B 2 O} 3 10 to 40%, the ZnO 20 to 50 %, RO (total of at least one selected from the group consisting of MgO, CaO, SrO, and BaO) 20-40%, R ₂ O (from the group consisting of Li ₂ O, Na ₂ O, and K ₂ O) Phosphor characterized by containing 0 to 10% of ZrO ₂ and 0 to 5% of ZrO ₂ (however, SiO ₂ + B ₂ O ₃ + ZnO + RO + R ₂ O + ZrO ₂ is 80% or more) Dispersion glass.

  In the present embodiment, RO (total of at least one selected from the group consisting of MgO, CaO, SrO, and BaO) is an essential component and is contained in the glass at 20 to 40%. Moreover, it is good also as 25 to 38% preferably.

Further, in this embodiment, SiO ₂ is intended to be contained in the range of 1-20%. Preferably it is good also as 2 to 15%.

Further, in the present _embodiment, B 2 _{O 3} is included at a content within a range of 10-40% in the glass. Preferably it may be 15 to 35%, more preferably 20 to 35%.

  Moreover, in this embodiment, ZnO is contained in 20 to 50% of range in glass. Preferably it is good also as 25 to 45%.

Further, in the present _embodiment, as B 2 _{O 3} and ZnO is 30 to 70% in total, is preferable to contain other components. More preferably, it may be 40 to 65%.

Further, in the present embodiment, ZrO ₂ is included at a content within a range of 0-5% in the glass. Preferably it is good also as 1-3%.

In this embodiment, R ₂ O (total of at least one selected from the group consisting of Li ₂ O, Na ₂ O, and K ₂ O) is contained in the range of 0 to 10%. Preferably the lower limit is 0
. It is good also as 2 mass% or more.

One of the preferred embodiments of the present invention is the phosphor-dispersed glass described above, wherein the glass is 10% by mass, SiO ₂ is 10 to 40%, B ₂ O ₃ is 15 to 65%, ZnO. 1 to 40
%, RO (total of at least one selected from the group consisting of MgO, CaO, SrO and BaO) is 0 to 20%, R ₂ O (from the group consisting of Li ₂ O, Na ₂ O and K ₂ O) Phosphor characterized by containing 8 to 30% of ZrO ₂ and 0 to 5% of ZrO ₂ (however, SiO ₂ + B ₂ O ₃ + ZnO + RO + R ₂ O + ZrO ₂ is 80% or more) Dispersion glass.

In this embodiment, R ₂ O (total of at least one selected from the group consisting of Li ₂ O, Na ₂ O, and K ₂ O) is an essential component and is contained in the range of 8 to 30%. . Preferably it is 10% or more and 15% or less of range.

Further, in this embodiment, SiO ₂ is intended to be contained in the range of 10-40%. Preferably, it may be 10 to 35%. The lower limit is preferably 12% or more, more preferably 20% or more.

Further, in the present _embodiment, B 2 _{O 3} is included at a content within a range of 15 to 65% in the glass. Preferably it is good also as 20 to 61%.

  Moreover, in this embodiment, ZnO is contained in 1 to 40% of range in glass. Preferably, it may be 5 to 35%. Further, the upper limit value may be more preferably 30% or less.

In the present embodiment, as 20-80% of B ₂ O ₃ and ZnO in the total, and adjust the softening point and coefficient of thermal expansion, so that possible glass devitrification suppression, the inclusion of other ingredients Is preferred. More preferably, it may be 30 to 78%. In particular, in order to suppress the deactivation of the phosphor, it is effective to prevent the phosphor from being damaged by heat. Therefore, while containing SiO ₂ which stabilizes the glass and raises the softening point, the RO component and R ₂ are contained. It is preferable to contain an O component to suppress an excessive increase in the softening point.

Further, in the present embodiment, ZrO ₂ is included at a content within a range of 0-5% in the glass. Preferably it is good also as 1-3%.

  In the present embodiment, RO (total of at least one selected from the group consisting of MgO, CaO, SrO, and BaO) is contained in the glass in an amount of 0 to 20%. Moreover, it is good also as 0 to 15% preferably.

In addition to the glass components of SiO ₂ , B ₂ O ₃ , ZnO, RO, R ₂ O and ZrO ₂ , the reaction between the glass and the phosphor can be suppressed by containing specific components. It became clear that the deactivation of the phosphor could be further suppressed. One kind of the specific component may be used, or a plurality of kinds may be used.

That is, the present invention preferably contains 0 to 18% by mass of Al ₂ O _{3 in the} glass.

Al ₂ O ₃ suppresses devitrification at the time of melting and sintering of the glass or suppresses reactivity with the phosphor, and is preferably contained in the range of 0 to 18% by mass. When it exceeds 18 mass%, stability of glass will be reduced. More preferably, it is the range of 16 mass% or less. Moreover, it is good also considering a lower limit as 0.2 mass% or more preferably.

  In the present invention, the glass preferably contains 0 to 10% by mass of antimony oxide.

Antimony oxide is presumed to be contained in the glass in the form of Sb ₂ O ₃ and Sb ₂ O ₅ , and is considered to exist mainly as Sb ₂ O ₃ . Sb ₂ O ₃ suppresses the reactivity with the phosphor and is preferably contained in the range of 0 to 10% by mass. When it exceeds 10 mass%, stability of glass will be reduced. More preferably, it is the range of 8 mass% or less. Moreover, it is good also considering a lower limit as 0.2 mass% or more preferably.

  In the present invention, the glass preferably contains 0 to 10% by mass of tin oxide.

Tin oxide is presumed to be contained in the form of SnO 2 _(2-x) (where 0 ≦ x <2), and is considered to exist as, for example, SnO ₂ or SnO. The tin oxide suppresses the reactivity with the phosphor and is preferably contained in the range of 0 to 10% by mass. When it exceeds 10 mass%, stability of glass will be reduced. More preferably, it is 8% or less. Moreover, it is good also considering a lower limit as 0.2 mass% or more preferably.

Further, Al 2 _O 3 described _above, by the addition of antimony oxide, and tin oxide, it is possible to suppress the reaction between the glass and the phosphor. Therefore, it is preferable that the glass contains 0.2% by mass or more and 18% by mass or less of a total of at least one selected from the group consisting of Al ₂ O ₃ , antimony oxide, and tin oxide. By adjusting each component contained in the glass composition so as to be within the above range, the effect of suppressing the deactivation of the phosphor can be improved. Further, SiO ₂ + B ₂ O ₃ + ZnO + RO + R ₂ O + ZrO ₂ + Al ₂ O ₃ + antimony oxide + tin oxide may be 100% by mass.

In addition to the above, a small amount of Nb ₂ O ₅ , TiO ₂ , WO ₃ , TeO ₂ , La ₂ O ₃ , CeO ₂ , P ₂ O ₅ or the like represented by a general oxide may be added.

Further, if Fe ₂ O ₃ or the like is contained in the glass, the transmittance of the glass may be lowered, which is not suitable for the purpose of the present invention. Therefore, it is preferable not to contain the said component substantially. Specifically, the content of the above components is preferably 0.01% by mass or less.

  Further, when PbO is contained in the glass, the glass is colored yellow and absorbs excitation light. Therefore, it is preferable that PbO is not substantially contained. Specifically, the content of the above components is preferably 0.01% by mass or less.

  The glass of the present invention preferably has a linear expansion coefficient of 6 to 13 ppm / ° C. and a softening point of 650 ° C. or less at 30 ° C. to 300 ° C. By lowering the softening point, it is possible to suppress the phosphor from being deactivated by heat during sintering. Preferably it is good also as 630 degrees C or less. Further, if the softening point is too low, the moisture resistance may be lowered, so the lower limit may be preferably 500 ° C. or higher.

  Usually, phosphors have different wavelengths for emitting excitation light depending on components constituting the phosphors. In the present invention, a phosphor having excitation light at a wavelength of 350 to 475 nm can be used for the phosphor-dispersed glass without any particular limitation on the type of the phosphor. That is, in the present invention, the phosphor particles preferably have excitation light at a wavelength of 350 to 475 nm. The present invention is particularly suitable for phosphor particles having excitation light at 415 nm to 475 nm, and more preferably 415 to 475 nm.

As said fluorescent substance particle, it is preferable to use at least 1 sort (s) chosen from the group which consists of an oxide, an oxynitride, a nitride, and a YAG type compound, for example. In particular, the present invention can be particularly suitably used for nitrides that are considered to be easily deactivated. In this example, (SrCa) AlSiN ₃ : Eu ²⁺ which is a nitride phosphor and Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ which is an oxide red phosphor are mixed and used, and good results are obtained. As a result, the present invention may include a plurality of types of phosphors.

  In addition, the conversion efficiency (excitation light to fluorescence intensity ratio) and light emission efficiency of the phosphor-dispersed glass of the present invention vary depending on the type and content of phosphor particles dispersed in the glass and the thickness of the phosphor-dispersed glass. . The content of phosphor particles and the thickness of the phosphor-dispersed glass may be adjusted so as to optimize the luminous efficiency and color rendering properties. There arises a problem that phosphor particles are not efficiently irradiated. Moreover, when there is too little content, it will become difficult to make it fully light-emit. Therefore, it is preferable to mix so that the content of the phosphor particles may be 0.01 to 50% by mass with respect to the total mass of the phosphor-dispersed glass. In particular, the content is preferably 0.5 to 40% by mass.

  As described above, the phosphor-dispersed glass of the present invention can be obtained by mixing a glass powder material and a phosphor powder and then sintering them. In that case, it is preferable to mix the glass powder material and the phosphor powder, and then to sinter the molded material once by pressurization or the like because the deactivation of the phosphor derived from heat can be suppressed. In addition to the above, the glass powder material and the phosphor powder may be mixed and then melted once and then molded using a mold or the like.

  When performing the above-mentioned sintering, it is desirable to sinter within the temperature range of the softening point of the glass powder material to the softening point + 100 ° C. or less, particularly the softening point to the softening point + 50 ° C. or less. Below the softening point, the glass is difficult to flow and it is difficult to obtain a dense sintered body. At high temperatures exceeding the softening point + 100 ° C., the phosphor may be deactivated and is not suitable for the purpose of the present invention.

  The phosphor-dispersed glass of the present invention may contain an inorganic filler.

  By containing the inorganic filler, it is possible to adjust thermal properties such as a linear expansion coefficient and a softening point when the phosphor-dispersed glass is sintered. Examples of the inorganic filler that can be used include zircon, mullite, silica, titania, and alumina. Moreover, what is necessary is just to adjust content of this inorganic filler suitably, For example, you may mix so that it may become 0.1 mass% or more and 40 mass% or less with respect to the total mass of this fluorescent substance dispersion | distribution glass.

  Glass used for the phosphor-dispersed glass (hereinafter sometimes referred to as “base material” or “base glass”) is a glass powder material pulverized to a size close to the particle diameter (1 to 100 μm) of the phosphor powder to be mixed Is preferably used. The pulverization may be performed using a mortar or a ball mill, but a jet mill type pulverizer with less contamination in the work process may be used.

  The mixture obtained by mixing the glass powder material of the base material and the phosphor powder obtained in the above manner in a desired ratio is molded into a pellet by pressurization, and the pellet is sintered by heating to obtain a phosphor-dispersed glass. It is possible to obtain. At this time, the phosphor powder content is preferably 0.01 to 50% by mass. When the phosphor powder exceeds 50% by mass, it becomes difficult to sinter, or the excitation light is not efficiently irradiated onto the phosphor particles. On the other hand, when the content is less than 0.01% by mass, the content is too small, and it becomes difficult to emit light sufficiently.

  Moreover, when pellet-forming by pressurization, it is preferable to carry out in a process that does not apply heat, and it is preferable to use a press molding method or the like. The atmosphere at the time of heating may be in the air or in an inert gas atmosphere such as nitrogen gas or Ar gas, but the air atmosphere is desirable in view of manufacturing costs. Furthermore, in order to suppress bubbles contained in the phosphor dispersion glass, sintering may be performed under reduced pressure, or pressure may be applied during sintering.

  In addition to the methods described above, the phosphor-dispersed glass may be obtained by kneading the glass powder material of the base material and the phosphor powder into an organic vehicle, applying the paste in a paste form, and then sintering. At this time, you may mix the inorganic filler mentioned above according to the objective. The organic vehicle can be suitably used as long as it desorbs at the glass sintering temperature.

  The phosphor-dispersed glass of the present invention can be suitably used as a white LED. In particular, since a nitride phosphor useful as a red phosphor can be sealed, a high color rendering white LED can be obtained.

  Examples of the present invention and comparative examples are described below.

First, various inorganic raw materials were weighed and mixed so as to have the raw material compositions A to T described in Tables 1 and 2, to prepare a raw material batch. This raw material batch was put into a platinum crucible and heated and melted in an electric heating furnace at 1100 to 1300 ° C. for 1 to 2 hours to obtain glass samples (A to S) shown in Tables 1 and 2. Since the composition of T was not vitrified, no further examination was performed. A part of the obtained glass was poured into a mold, made into a block shape, and used for measurement of thermal properties (thermal expansion coefficient, softening point). The remaining glass was formed into flakes with a rapid cooling twin roll molding machine, and sized into a glass powder sample having an average particle size of 1 to 30 μm and a maximum particle size of less than 100 μm by a pulverizer. In this example, SnO was used as a raw material for tin oxide. Since tin oxide in the glass is SnO _(2-x) (where 0 ≦ x <2) and it is difficult to measure a clear oxidation state, SnO _(2-x) is shown in Tables 1 and 2. It was described.

  The softening point was measured using a thermal analyzer TG-DTA (manufactured by Rigaku Corporation). Moreover, the said thermal expansion coefficient calculated | required the linear expansion coefficient from the amount of elongation at 30-300 degreeC when it heated up at 5 degree-C / min using the thermal dilatometer.

Example 1
Nitride red phosphor powder ((SrCa) AlSiN ₃ : Eu ²⁺ , emission center wavelength 610 nm) was added to the obtained glass powder material and mixed to obtain a mixed powder (phosphor content: 4 mass%). In addition, the composition of A-N of Table 1 was used for the glass powder material. Next, a button-shaped preform having a diameter of 10 mm and a thickness of 2 mm was produced by pressure molding with a mold. Next, it sintered by heating for 30 minutes in air | atmosphere, and obtained the sintered compact. Table 3 shows the used glass powder material, phosphor powder, sintering temperature, and color tone of the obtained sintered body.

Example 2
Example 1 except that the composition of B and I in Table 1 was used for the glass powder material and a nitride red phosphor (CaAlSiN ₃ : Eu ²⁺ , emission center wavelength of 630 nm) powder was used for the phosphor powder. A sintered body was obtained by this method. The sintering temperature is as described in Table 3.

Comparative Example 1
A sintered body was obtained in the same manner as in Example 1 except that the composition of O to S in Table 2 was used for the glass powder material. The sintering temperature is as described in Table 3.

Example 3
Example 1 except that the composition of E in Table 1 was used for the glass powder material and oxide red phosphor (Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , emission center 555 nm) powder was used for the phosphor powder. Thus, a sintered body was obtained. The sintering temperature is as described in Table 4.

Example 4
The composition of C, E, and J to N of Table 1 was used for the glass powder material, and oxide red phosphor (Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , emission center 540 nm) powder was used for the phosphor powder. A sintered body was obtained in the same manner as in Example 1. The sintering temperature is as described in Table 4.

Example 5
The obtained glass powder material is mixed with an inorganic filler (SiO ₂ filler, particle size 0.3 μm) and nitride red phosphor powder ((SrCa) AlSiN ₃ : Eu ²⁺ , emission center wavelength 610 nm). (Inorganic filler content: 2 mass%, phosphor content: 4 mass%). In addition, the composition of N of Table 1 was used for the glass powder material. Next, a button-shaped preform having a diameter of 10 mm and a thickness of 2 mm was produced by pressure molding with a mold. Next, it sintered by heating for 30 minutes in air | atmosphere, and obtained the sintered compact. Table 3 shows the glass powder material, inorganic filler, phosphor powder, sintering temperature, and color tone of the obtained sintered body.

Example 6
A sintered body was obtained in the same manner as in Example 5 except that oxide red phosphor (Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , emission center 555 nm) powder was used as the phosphor powder to be used. Table 4 shows the glass powder material, inorganic filler, phosphor powder, sintering temperature, and color tone of the obtained sintered body.

<Measurement of quantum efficiency>
The internal quantum efficiency (η _int ) and the external quantum efficiency (η _ext ) of each of the sintered bodies obtained in Examples 1 to 6 and Comparative Example 1 were measured and are shown in Tables 3 and 4. The measurement is performed using a fluorescence spectrophotometer (FP-6500 manufactured by JASCO Corporation) to which an integrating sphere (ILF-533 manufactured by JASCO Corporation) is connected. Assuming that the integrated intensity of the absorbed excitation light spectrum is B, the integrated intensity of the fluorescence spectrum emitted from the sample is C, the internal quantum efficiency is C / B, and the external quantum efficiency is C / A. It can be said that the higher the internal quantum efficiency and the external quantum efficiency, the higher the light emission efficiency.

In addition, when the internal quantum efficiency of the nitride red phosphor used in the study was measured before glass sealing, (SrCa) AlSiN ₃ : Eu ²⁺ was 84%, CaAlSiN ₃ : Eu ²⁺ was 83%, and Y ₃ Al ₅ O ₁₂ : Ce ³⁺ was 83%, and Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ was 81%.

  When Examples 1 and 2 and Comparative Example 1 using a nitride red phosphor were compared, the internal quantum efficiency and external quantum efficiency of Comparative Example 1 were both 10% or less, whereas Examples 1 and 2 All were 18% or more. Further, the color tone of the sintered body was black or gray in Comparative Example 1, whereas Examples 1 and 2 were dark orange, orange, and bright orange. From the above, it was shown that the present invention can suppress the deactivation of the nitride red phosphor.

  In Examples 3 and 4 using the oxide red phosphor, the internal quantum efficiency was 60 to 81%. The internal quantum efficiency of the oxide red phosphor before glass sealing was 83% and 81%, respectively, and the internal quantum efficiency did not decrease or the internal quantum efficiency was suppressed from decreasing. In addition, the color tone of the sintered body was light yellow. From the above, it was shown that the present invention can suppress the deactivation of the oxide red phosphor.

  Moreover, Example 5 and 6 which mixed the inorganic filler was able to suppress the fall of internal quantum efficiency and external quantum efficiency similarly to the other Example which was not made to mix an inorganic filler. Moreover, since there was no big change in the color tone of a sintered compact, it was shown that this invention can utilize an inorganic filler.

Example 7
The composition of E in Table 1 as a glass powder sample, 5% by weight of (SrCa) AlSiN ₃ : Eu ²⁺ powder as nitride phosphor powder, and Lu ₃ Al ₅ O ₁₂ : Ce ³ as oxide red phosphor
⁺ 3% by weight of powder was mixed to make a mixed powder. Next, the mixed powder was pressure-molded with a mold to prepare a button-shaped preform having a diameter of 10 mm and a thickness of 2 mm. Next, it was heated at 610 ° C. for 30 minutes in the air to obtain a sintered body. As a result, the sintered body became bright orange.

When the internal quantum efficiency and the external quantum efficiency of the sintered body obtained in Example 7 were measured using the method described above, the internal quantum efficiency was 61% and the external quantum efficiency was 50%. That is, it has been clarified that the deactivation of the phosphor can be suppressed even when the oxide phosphor and the nitride phosphor are used in combination. Therefore, it was confirmed that the present invention can also be used for phosphor-dispersed glass that is sealed by using a plurality of types of phosphors in combination.

Claims (5)

A phosphor-dispersed glass in which phosphor particles having excitation light at a wavelength of 350 to 475 nm are dispersed in glass, and the glass is in mass%,
The SiO ₂ 1~40%,
15 to 65% of B ₂ O ₃
ZnO 1-50%,
RO (total of at least one selected from the group consisting of MgO, CaO, SrO, and BaO) is 0 to 40%,
Li ₂ O 0-3%,
0 to 30% of R ₂ O (total of at least one selected from the group consisting of Li ₂ O, Na ₂ O, and K ₂ O),
0.2 to 18% by mass of Al ₂ O ₃ ,
Containing 0 to 5% of ZrO ₂ (provided that SiO ₂ + B ₂ O ₃ + ZnO + RO + R ₂ O + ZrO ₂ is 80% or more),
Phosphor dispersed glass B ₂ O ₃ + ZnO is characterized in that as a 30 to 74 wt%. The phosphor-dispersed glass according to claim 1, wherein the glass contains 0.2 to 18% by mass of a total of Al ₂ O ₃ , antimony oxide, and tin oxide. The phosphor-dispersed glass according to claim 1 or 2, wherein the phosphor particles are at least one selected from the group consisting of oxynitrides and nitrides. The phosphor-dispersed glass according to any one of claims 1 to 3, wherein the content of the phosphor particles is 0.01 to 50 mass%. The phosphor-dispersed glass according to any one of claims 1 to 4, wherein the phosphor-dispersed glass contains an inorganic filler.