JP2008038050A - Phosphor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a phosphor capable of providing a phosphor layer having a high emission luminance even after passage of irradiation time of excitation source. <P>SOLUTION: The phosphor comprises a first phosphor composed of a compound represented by formula (1) mM<SP>11</SP>O-nM<SP>21</SP>O-2M<SP>31</SP>O<SB>2</SB>(1) as a parent body containing an activator (activator 1) and a second phosphor composed of a compound represented by formula (2) pM<SP>12</SP>O-qM<SP>22</SP>O-2M<SP>32</SP>O<SB>2</SB>(2) as a parent body containing an activator (activator 2) (M<SP>11</SP>and M<SP>12</SP>are each selected from Ca, Sr and Ba; M<SP>21</SP>and M<SP>22</SP>are each Mg and/or Zn; M<SP>31</SP>and M<SP>32</SP>are each Si and/or Ge; m is ≥2.5 and ≤3.5; n is ≥0.5 and ≤1.5; p is ≥0.5 and ≤1.5; q is ≥0.5 and ≤1.5). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a phosphor.

  Since the phosphor emits light when irradiated with an excitation source, it is used in a light emitting element. Examples of the light emitting device include an electron beam excited light emitting device (for example, a cathode ray tube, a field emission display, a surface electric field display, etc.) in which the excitation source of the phosphor is an electron beam; , Backlights for liquid crystal displays, three-wavelength fluorescent lamps, high-load fluorescent lamps, etc.), vacuum ultraviolet-excited light emitting devices whose phosphor excitation source is vacuum ultraviolet (for example, plasma display panels, rare gas lamps, etc.), phosphors The white LED whose light source is the light emitted from the blue LED or the light emitted from the ultraviolet LED can be used. In the light emitting device as described above, the phosphor is usually used as a phosphor layer.

As a conventional phosphor, Patent Document 1 discloses a phosphor made of a compound represented by the formula Ca _0.49 Sr _0.49 Eu _0.02 MgSi ₂ O ₆ .

JP 2006-104445 A

  However, when an excitation source is irradiated to a phosphor layer obtained using a conventional phosphor, the emission luminance tends to decrease as the irradiation time of the excitation source elapses. It is hard to say that the characteristics are sufficient. An object of the present invention is to provide a phosphor capable of obtaining a phosphor layer having high emission luminance even after the irradiation time of an excitation source has elapsed.

The inventors of the present invention have intensively studied to solve the above-mentioned problems and have arrived at the present invention.
That is, the present invention provides the following <1> to <9> inventions.
<1> A first fluorescent substance containing an activator (activator 1) based on a compound represented by the following formula (1) and a compound represented by the following formula (2) A phosphor containing a second fluorescent material containing an activator (activator 2) as a base.
mM ¹¹ O · nM ²¹ O · 2M ³¹ O ₂ (1)
pM ¹² O · qM ²² O · 2M ³² O ₂ (2)
(The above M ¹¹ and M ¹² independently represent one or more elements selected from the group consisting of Ca, Sr and Ba, M ²¹ and M ^{22 each} independently represent Mg and / or Zn, and M ³¹ , M ³² independently represents Si and / or Ge, m is a value in the range of 2.5 to 3.5, n is a value in the range of 0.5 to 1.5, and p is (The value is in the range of 0.5 to 1.5, and q is the value in the range of 0.5 to 1.5.)
<2> The phosphor according to <1>, wherein the activator 1 contains at least Eu.
<3> The phosphor according to <1> or <2>, wherein the activator 2 contains at least Eu.
<4> The phosphor according to <2> or <3>, wherein the first fluorescent substance is represented by the following formula (11).
_{Ca 3-abc Sr a Ba b} Eu c MgSi 2 O 8 (11)
(Wherein, a is a value in the range of 0 to less than 3, b is a value in the range of 0 to less than 3, c is a value in the range of more than 0 and less than 0.2, and a + b + c is The value is in the range of more than 0 and less than 3.)
<5> The phosphor according to any one of <2> to <4>, wherein the second fluorescent substance is represented by the following formula (21).
Ca _1-de Sr _d Eu _e MgSi ₂ O ₆ (21)
(In the formula, d is a value in the range of 0.05 or more and less than 1, e is a value in the range of greater than 0 and less than or equal to 0.2, and d + e is a value in the range of greater than 0.05 and less than or equal to 1. .)
<6> The first fluorescent material and the second fluorescent material are contained so that the weight ratio of the first fluorescent material to the second fluorescent material is 50:50 to 5:95 <1> ~ The phosphor according to any one of <5>.
<7> A phosphor paste having the phosphor according to any one of <1> to <6>.
<8> A phosphor layer obtained by heat-treating the phosphor paste according to <7> above on a substrate.
<9> A light emitting device comprising the phosphor according to any one of <1> to <6>.

  Since the phosphor layer obtained using the phosphor of the present invention has high emission luminance even after the irradiation time of an excitation source such as vacuum ultraviolet rays has elapsed, the phosphor of the present invention is a vacuum ultraviolet excited light emitting element. It is preferably used as a plasma display panel and particularly preferably used as a plasma display panel. Moreover, the phosphor of the present invention can be applied to an ultraviolet-excited light emitting device such as a backlight for a liquid crystal display, an electron beam excited light emitting device such as a field emission display, and a light emitting device such as a white LED. Useful.

The present invention is described in detail below.
The present invention provides a first fluorescent substance containing an activator (activator 1) based on a compound represented by the following formula (1) and a compound represented by the following formula (2). And a second fluorescent material containing an activator (activator 2) as a base. Since the phosphor layer obtained using the phosphor has high emission luminance even after the irradiation time of an excitation source such as vacuum ultraviolet rays has elapsed, the phosphor of the present invention is preferably used for a light emitting device. Is done.
mM ¹¹ O · nM ²¹ O · 2M ³¹ O ₂ (1)
pM ¹² O · qM ²² O · 2M ³² O ₂ (2)
(The above M ¹¹ and M ¹² independently represent one or more elements selected from the group consisting of Ca, Sr and Ba, M ²¹ and M ^{22 each} independently represent Mg and / or Zn, and M ³¹ , M ³² independently represents Si and / or Ge, m is a value in the range of 2.5 to 3.5, n is a value in the range of 0.5 to 1.5, and p is (The value is in the range of 0.5 to 1.5, and q is the value in the range of 0.5 to 1.5.)

  In the present invention, the host compound of the fluorescent substance contains an activator and emits light by irradiation with an excitation source. More specifically, a fluorescent material that emits light when irradiated with an excitation source is obtained by substituting a part of the element constituting the base compound of the fluorescent material with an element that serves as an activator. Examples of the element serving as the activator include Eu, Ce, Pr, Nd, Sm, Tb, Dy, Er, Tm, Yb, Bi, and Mn.

  In order to increase the emission luminance, the activator 1 in the first fluorescent material preferably contains at least Eu, and Eu preferably has a high proportion of divalent Eu ions. When the activator 1 contains Eu, Al, Sc, Y, La, Gd, Ce, Pr, Nd, Pm, Sm, Tb, Dy, Ho, Er, Tm, Yb, Lu, Bi, The light emission luminance may be further increased by containing one or more elements selected from the group consisting of Au, Ag, Cu, and Mn.

  In order to increase the emission luminance, the activator 2 in the second fluorescent material preferably contains at least Eu, and Eu preferably has a high proportion of divalent Eu ions. When the activator 1 contains Eu, Al, Sc, Y, La, Gd, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, The light emission luminance may be further increased by containing one or more elements selected from the group consisting of Bi, Au, Ag, Cu, and Mn.

In order to increase the emission luminance of the phosphor of the present invention, the first phosphor is preferably represented by the following formula (11).
_{Ca 3-abc Sr a Ba b} Eu c MgSi 2 O 8 (11)
(Wherein, a is a value in the range of 0 to less than 3, b is a value in the range of 0 to less than 3, c is a value in the range of more than 0 and less than 0.2, and a + b + c is The value is in the range of more than 0 and less than 3.)

  In the above formula (11), a is a value in the range from 1.9 to 2.6, and b is a value in the range from 0.3 to 1.1, in order to increase the emission luminance of the phosphor. It is preferable that Further, from the viewpoint of production cost, c is preferably a value in the range of 0.001 to 0.03.

In order to increase the emission luminance of the phosphor of the present invention, the second fluorescent material is preferably represented by the following formula (21).
Ca _1-de Sr _d Eu _e MgSi ₂ O ₆ (21)
(In the formula, d is a value in the range of 0.05 or more and less than 1, e is a value in the range of greater than 0 and less than or equal to 0.2, and d + e is a value in the range of greater than 0.05 and less than or equal to 1. .)

  In the above formula (21), d is preferably a value in the range of 0.4 or more and 0.6 or less, in order to increase the emission luminance of the phosphor layer after the irradiation time of the excitation source has elapsed. Further, e is preferably a value in the range of 0.001 or more and 0.03 or less from the viewpoint of the balance between emission luminance and manufacturing cost.

In the compound represented by the above formula (1) and / or formula (2), a part of each of the constituent elements M ¹¹ , M ²¹ , M ³¹ , M ¹² , M ²² and M ³² is monovalent. It may be substituted with a metal element and / or a trivalent metal element. Examples of the monovalent and trivalent metal elements include Li, Na, K, Rb, Fe, In, La, Lu, Bi, and Sb. By such substitution, the emission luminance of the phosphor of the present invention may increase.

  In the fluorescent substance represented by the above formula (11) and / or formula (21), at least one selected from the group consisting of Zn, W and Mo is part of Mg within a range not inhibiting the effect of the present invention. You may substitute by the element of. As a range which does not inhibit this, it is about 10 mol% or less of Mg normally.

  The phosphor of the present invention may further contain at least one element selected from the group consisting of F, Cl, Br and I. The content of these elements is 1 ppm or more and 20000 ppm or less, preferably 1 ppm or more and 1000 ppm or less with respect to the total weight of the phosphor containing these elements. By containing at least one element selected from the group consisting of F, Cl, Br and I as described above, the emission luminance of the phosphor of the present invention may be increased.

  In the present invention, the first fluorescent material and the second fluorescent material may be contained so that the weight ratio of the first fluorescent material: the second fluorescent material is 50:50 to 5:95. It is preferably 40:60 to 10:90, and more preferably 35:65 to 85:15. By containing in this way, the effect of this invention can be improved more.

  In the present invention, either one of the first fluorescent substance and the second fluorescent substance may have an average particle diameter of not more than 5 times the average particle diameter of the other fluorescent substance. preferable. Here, the average particle diameter is a value measured by a scanning electron micrograph, and an average of values obtained by arbitrarily extracting 50 particles from primary particles photographed in the photograph and measuring each particle diameter. Value.

  The phosphor of the present invention is manufactured, for example, as follows. That is, the phosphor of the present invention can be manufactured by mixing the first fluorescent material and the second fluorescent material. Examples of the mixing method include a method using a mixing device that is usually used industrially, such as a method using a stirring device, a method using a ball mill, and a method using a three-roll mill. The mixing at this time may be either dry mixing or wet mixing. Moreover, you may mix fluorescent substances other than a 1st fluorescent substance and a 2nd fluorescent substance in the range which does not inhibit the effect of this invention at this time. Further, the phosphor obtained after mixing may be subjected to heat treatment at a temperature of 300 ° C. to 1000 ° C. for 10 minutes to 10 hours in an air atmosphere or a reducing atmosphere.

  The first fluorescent material can be produced by firing a metal compound mixture that becomes the first fluorescent material by firing. Further, the second fluorescent material can be produced by firing a metal compound mixture that becomes the second fluorescent material by firing. That is, each of the first and second fluorescent materials is manufactured by firing a metal compound mixture obtained after weighing and mixing a compound containing a corresponding metal element so as to have a predetermined composition. Can do.

For example, when one of the preferred first fluorescent materials is represented by the formula (Ba _0.995 Sr _0.5 Ca _1.5 Eu _0.005 ) MgSi ₂ O ₈ , BaCO ₃ , SrCO ₃ , MgO, SiO ₂ , Each raw material of Eu ₂ O ₃ was weighed so that the molar ratio of Ba: Sr: Ca: Mg: Si: Eu was 0.995: 0.5: 1.5: 1: 2: 0.005, and they were It can manufacture by baking the metal compound mixture obtained by mixing.

In addition, for example, in the case of a preferable second fluorescent material, when the fluorescent material is represented by the formula Ca _0.892 Sr _0.1 Eu _0.008 MgSi ₂ O ₆ , CaCO ₃ , SrCO ₃ , MgO, SiO ₂ , Eu ₂ O ₃ Each raw material is weighed so that the molar ratio of Ca: Sr: Mg: Si: Eu is 0.892: 0.1: 1: 2: 0.008, and the resulting metal compound mixture is fired. Can be manufactured.

  Examples of the compound containing the metal element include Ca, Sr, Ba, Mg, Zn, Si, Ge, Eu, Al, Sc, Y, La, Gd, Ce, Pr, Nd, Pm, Sm, and Gd. , Tb, Dy, Ho, Er, Tm, Yb, Lu, Bi, Au, Ag, Cu and Mn, using oxides or hydroxides, carbonates, nitrates, halides, oxalates What can be decomposed and / or oxidized at a high temperature to form an oxide may be used.

  For the mixing of the compound containing the metal element, a generally industrially used apparatus such as a ball mill, a V-type mixer or a stirrer can be used. At this time, either dry mixing or wet mixing may be used. Further, a metal compound mixture having a predetermined composition may be obtained by a crystallization method.

  For example, a fluorescent material is obtained by baking the metal compound mixture while maintaining the temperature in the range of 900 ° C. to 1500 ° C. for 0.5 hours to 100 hours. When a compound that can be decomposed and / or oxidized at high temperature, such as hydroxide, carbonate, nitrate, halide, oxalate, etc., is used in the metal compound mixture, the temperature ranges from 400 ° C to 1200 ° C. The firing may be performed after holding and calcining to obtain an oxide or removing crystal water. The atmosphere for calcination may be an inert gas atmosphere, an oxidizing atmosphere, or a reducing atmosphere. Moreover, it can also grind | pulverize after calcination.

  When the first fluorescent material is represented by the above formula (11), a temperature range of 1100 ° C. or higher and 1250 ° C. or lower is preferable among the firing temperature range of the above range. A temperature range of 1150 ° C. or higher and 1190 ° C. or lower is more preferable.

  When the second fluorescent material is represented by the above formula (21), a temperature range of 1100 ° C. or more and 1200 ° C. or less is preferable in the above-described firing temperature range. A temperature range of 1150 ° C. or higher and 1180 ° C. or lower is more preferable.

  As an atmosphere during firing, for example, an inert gas atmosphere such as nitrogen or argon; an oxidizing atmosphere such as air, oxygen, oxygen-containing nitrogen, oxygen-containing argon; or hydrogen-containing nitrogen containing 0.1 to 10% by volume of hydrogen A reducing atmosphere such as hydrogen-containing argon containing 0.1 to 10% by volume of hydrogen is preferable. When firing in a strong reducing atmosphere, an appropriate amount of carbon may be contained in the metal compound mixture and fired.

By using fluoride, chloride or the like as the compound containing a metal element, the crystallinity of the fluorescent substance to be generated can be increased and / or the average particle diameter can be increased. For that purpose, an appropriate amount of flux may be added. Examples of the flux include LiF, NaF, KF, LiCl, NaCl, KCl, Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , NaHCO ₃ , NH ₄ Cl, NH ₄ I, MgF ₂ , CaF ₂ , _{SrF 2, BaF 2, MgCl 2} , CaCl 2, SrCl 2, BaCl 2, MgI 2, CaI 2, SrI 2, BaI 2 , and the like.

  The fluorescent material obtained as described above may be pulverized, washed, or classified using, for example, a ball mill or a jet mill. Moreover, you may perform baking twice or more. Further, a surface treatment such as coating the particle surface of the fluorescent substance with an inorganic substance containing Si, Al, Ti or the like may be performed.

Next, the phosphor paste having the phosphor of the present invention will be described.
The phosphor paste of the present invention contains the phosphor of the present invention and an organic substance as main components, and examples of the organic substance include a solvent and a binder. The phosphor paste of the present invention can be used in the same manner as the phosphor paste used in the manufacture of conventional light emitting devices, and the organic substance in the phosphor paste is removed by volatilization, combustion, decomposition, etc. by heat treatment. This is a phosphor paste capable of obtaining a phosphor layer substantially composed of the phosphor of the present invention.

  The phosphor paste of the present invention can be produced, for example, by a known method as disclosed in JP-A-10-255671. For example, the phosphor of the present invention, a binder and a solvent are mixed with a ball mill, It can be obtained by mixing using a triple roll or the like.

  Examples of the binder include cellulose resins (ethyl cellulose, methyl cellulose, nitrocellulose, acetyl cellulose, cellulose propionate, hydroxypropyl cellulose, butyl cellulose, benzyl cellulose, modified cellulose, etc.), acrylic resins (acrylic acid, methacrylic acid, methyl Acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-hydroxyethyl acrylate, 2 -Hydroxyethyl methacrylate, 2-hydroxypropyl acetate Rate, 2-hydroxypropyl methacrylate, benzyl acrylate, benzyl methacrylate, phenoxy acrylate, phenoxy methacrylate, isobornyl acrylate, isobornyl methacrylate, glycidyl methacrylate, styrene, α-methylstyrene acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, etc. At least one polymer among monomers), ethylene-vinyl acetate copolymer resin, polyvinyl butyral, polyvinyl alcohol, propylene glycol, polyethylene oxide, urethane resin, melamine resin, phenol resin and the like.

  Examples of the solvent include those having a high boiling point among monohydric alcohols; polyhydric alcohols such as diols and triols typified by ethylene glycol and glycerin; compounds obtained by etherification and / or esterification of alcohols (ethylene glycol monoalkyl ethers) Ethylene glycol dialkyl ether, ethylene glycol alkyl ether acetate, diethylene glycol monoalkyl ether acetate, diethylene glycol dialkyl ether, propylene glycol monoalkyl ether, propylene glycol dialkyl ether, propylene glycol alkyl acetate), and the like.

  The phosphor paste obtained as described above is applied to a substrate and then heat treated to obtain a phosphor layer. Examples of the substrate include glass and resin, and the substrate may be flexible, and the shape may be a plate or a container. Examples of the coating method include a screen printing method and an ink jet method. Moreover, as temperature of heat processing, it is 300 to 600 degreeC normally. In addition, drying may be performed at a temperature of room temperature to 300 ° C. after application to the substrate and before heat treatment.

  Here, a plasma display panel, which is a vacuum ultraviolet ray-excited light emitting element, will be described as an example of the light emitting element having the phosphor of the present invention, and a manufacturing method thereof will be described. As a method for producing a plasma display panel, for example, a known method as disclosed in JP-A-10-195428 can be used. That is, when the phosphor of the present invention emits blue light, each phosphor composed of the green phosphor, the red phosphor, and the blue phosphor of the present invention is replaced with a binder made of, for example, a cellulose-based resin or polyvinyl alcohol. Then, a phosphor paste is prepared by mixing with a solvent. A phosphor paste is applied to the inner surface of the rear substrate by a method such as screen printing on the stripe-shaped substrate surface and the partition surface partitioned by the partition and provided with address electrodes, and heat-treated at a temperature range of 300 to 600 ° C., The phosphor layer is obtained. A surface glass substrate provided with a transparent electrode and a bus electrode in a direction orthogonal to the phosphor layer and provided with a dielectric layer and a protective layer on the inner surface is laminated and bonded thereto. A plasma display panel can be manufactured by exhausting the inside and enclosing a rare gas such as low-pressure Xe or Ne to form a discharge space.

  Next, as an example of the light emitting device having the phosphor of the present invention, a field emission display which is an electron beam excited light emitting device will be described and the manufacturing method thereof will be described. As a method for manufacturing a field emission display, for example, a known method as disclosed in JP-A-2002-138279 can be used. That is, when the phosphor of the present invention emits blue light, each phosphor composed of the green phosphor, the red phosphor, and the blue phosphor of the present invention is dispersed in, for example, an aqueous polyvinyl alcohol solution. To prepare a phosphor paste. The phosphor paste is applied on a glass substrate and then heat-treated to obtain a phosphor layer to obtain a face plate. A field emission display can be manufactured through a normal process such as assembling the face plate and a rear plate having a large number of electron-emitting devices via a support frame and hermetically sealing these gaps while evacuating them. it can.

  Next, white LED is mentioned as a light emitting element which has the fluorescent substance of this invention, and the manufacturing method is demonstrated. As a method for producing a white LED, for example, known methods as disclosed in JP-A-5-152609 and JP-A-7-99345 can be used. That is, the phosphor containing at least the phosphor of the present invention is dispersed in a translucent resin such as epoxy resin, polycarbonate, silicon rubber, and the resin in which the phosphor is dispersed surrounds the blue LED or the ultraviolet LED. White LED can be manufactured by shape | molding.

  Next, as a light emitting element having the phosphor of the present invention, a high load fluorescent lamp (a small fluorescent lamp having a large power consumption per unit area of the lamp tube wall) which is an ultraviolet-excited light emitting element will be described and a manufacturing method thereof will be described. . As a method for producing a high-load fluorescent lamp, for example, a known method as disclosed in JP-A-10-251636 can be used. That is, when the phosphor of the present invention emits blue light, each phosphor composed of the green phosphor, the red phosphor, and the blue phosphor particles of the present invention is dispersed in, for example, an aqueous polyethylene oxide solution. A phosphor paste is prepared. This phosphor paste is applied to the inner wall of the glass tube, dried, and then heat treated in a temperature range of 300 to 600 ° C. to obtain a phosphor layer. A high load fluorescent lamp is formed by attaching a filament to this, passing through a normal process such as exhaust, enclosing rare gas such as low pressure Ar, Kr and Ne and mercury and attaching a base to form a discharge space. Can be manufactured.

  Next, the present invention will be described more specifically with reference to examples. Unless otherwise stated, each evaluation of the phosphor was performed as follows.

  The phosphor paste was obtained as follows. The phosphor powder was weighed so that the phosphor powder was 33 parts by weight, the ethyl cellulose was 7 parts by weight, and the mixture of diethylene glycol mono-n-butyl ether and diethylene glycol mono-n-butyl ether acetate was 60 parts by weight, and kneaded thoroughly to obtain a phosphor paste 100 parts by weight were obtained.

  The phosphor layer was obtained as follows. The phosphor paste was applied on a glass substrate, dried at 100 ° C., and then heat-treated at 500 ° C. for 30 minutes in an air atmosphere to obtain a phosphor layer having a thickness of about 20 μm.

The influence of irradiation of the excitation source was investigated as follows. The phosphor layer is placed in a vacuum chamber, kept at a vacuum of 6.7 Pa (5 × 10 ⁻² torr) or less, and vacuum ultraviolet rays are applied for a predetermined time (ex. Hima type manufactured by USHIO INC.). 24 hours). After this irradiation, the phosphor layer was caused to emit light using an excimer 172 nm lamp (made by USHIO INC., Type H0016), and the emission luminance at that time was measured using a spectroradiometer (made by Topcon Corporation, SR-3). I investigated.

  The crystal structure of the phosphor was analyzed by a powder X-ray diffraction method using CuKα as a radiation source, using an RINT2500 TTR type X-ray diffraction measurement apparatus manufactured by Rigaku Corporation.

Comparative Example 1
Calcium carbonate (manufactured by Ube Materials, CaCO ₃ ), strontium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., SrCO ₃ ), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., Eu ₂ O ₃ ), magnesium carbonate ( Kyowa Chemical Co., Ltd., MgCO ₃ ), silicon oxide SiO ₂ (manufactured by Nippon Aerosil Co., Ltd., SiO ₂ ) Each raw material has a molar ratio of CaCO ₃ : SrCO ₃ : Eu ₂ O ₃ : MgCO ₃ : SiO ₂ is 0 494: 0.494: 0.012: 1: 2 were weighed and mixed, and then calcined by holding at a temperature of 1150 ° C. for 2 hours in a N ₂ atmosphere containing ₂ % by volume of H ₂ . Firing was performed three times. Thus, phosphor 1 represented by the formula Ca _0.494 Sr _0.494 Eu _0.012 MgSi ₂ O ₆ was obtained. FIG. 1 shows an X-ray diffraction pattern of the phosphor 1. Using this phosphor 1, a phosphor paste was prepared, a phosphor layer 1 was obtained, and after the phosphor layer 1 was irradiated with vacuum ultraviolet rays, the emission luminance was measured. The light emission luminance at that time was set to 100 (hereinafter, the light emission luminance of the phosphor layer was shown as relative luminance with the light emission luminance of the phosphor layer 1 being 100). The obtained results are shown in Table 1.

Comparative Example 2
Barium carbonate (manufactured by Nippon Chemical Industry Co., Ltd .: purity 99% or more), strontium carbonate (manufactured by Sakai Chemical Industry Co., Ltd .: purity 99% or more) and basic magnesium carbonate (manufactured by Kyowa Chemical Industry Co., Ltd .: purity 99% or more) Each raw material of silicon dioxide (manufactured by Nippon Aerosil Co., Ltd .: purity 99.99%) and europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd .: purity 99.99%) has a molar ratio of Ba: Sr: Mg: Si: Eu of 0. 495: 2.5: 1: 2: 0.005, and then weighed and mixed, and then fired in a ₂ % H ₂ -containing N ₂ atmosphere at a temperature of 1170 ° C. for 2 hours. Firing was performed twice. Thus, the phosphor 2 represented by the formula (Ba _0.495 Sr _2.5 Eu _0.005 ) MgSi ₂ O ₈ was obtained. FIG. 2 shows an X-ray diffraction pattern of the phosphor 2. Using this phosphor 2, a phosphor layer 2 was obtained in the same manner as in Comparative Example 1, and the emission luminance was measured after irradiation with vacuum ultraviolet rays. The relative luminance was 102. The obtained results are shown in Table 1.

Examples 1-6
Phosphors 3 and 8 (Examples 1 to 6) were obtained by weighing a predetermined amount of each of phosphor 1 and phosphor 2, and performing wet mixing using ethanol and drying. The weight ratio of phosphor 1 to phosphor 2 in phosphors 3 to 8 is 90:10 (phosphor 3), 80:20 (phosphor 4), 75:25 (phosphor 5), and 65:35 (fluorescence). Body 6), 50:50 (phosphor 7), and 25:75 (phosphor 8). For each of the phosphors 3 to 8, phosphor layers 3 to 8 were obtained in the same manner as in Comparative Example 1, and the emission luminance was measured after irradiation with vacuum ultraviolet rays. The relative luminance obtained is shown in Table 1. FIG. 3 shows an X-ray diffraction pattern of the phosphor 5.

An X-ray diffraction pattern of phosphor 1. X-ray diffraction pattern of phosphor 2. X-ray diffraction pattern of phosphor 5.

Claims (9)

A first fluorescent substance containing an activator (activator 1) based on a compound represented by the following formula (1) and a compound represented by the following formula (2) as a matrix. A phosphor containing a second fluorescent material containing an activator (activator 2).
mM ¹¹ O · nM ²¹ O · 2M ³¹ O ₂ (1)
pM ¹² O · qM ²² O · 2M ³² O ₂ (2)
(The above M ¹¹ and M ¹² independently represent one or more elements selected from the group consisting of Ca, Sr and Ba, M ²¹ and M ^{22 each} independently represent Mg and / or Zn, and M ³¹ , M ³² independently represents Si and / or Ge, m is a value in the range of 2.5 to 3.5, n is a value in the range of 0.5 to 1.5, and p is (The value is in the range of 0.5 to 1.5, and q is the value in the range of 0.5 to 1.5.)   The phosphor according to claim 1, wherein the activator 1 contains at least Eu.   The phosphor according to claim 1 or 2, wherein the activator 2 contains at least Eu. The phosphor according to claim 2 or 3, wherein the first fluorescent material is represented by the following formula (11).
_{Ca 3-abc Sr a Ba b} Eu c MgSi 2 O 8 (11)
(Wherein, a is a value in the range of 0 to less than 3, b is a value in the range of 0 to less than 3, c is a value in the range of more than 0 and less than 0.2, and a + b + c is The value is in the range of more than 0 and less than 3.) The phosphor according to any one of claims 2 to 4, wherein the second fluorescent material is represented by the following formula (21).
Ca _1-de Sr _d Eu _e MgSi ₂ O ₆ (21)
(In the formula, d is a value in the range of 0.05 or more and less than 1, e is a value in the range of greater than 0 and less than or equal to 0.2, and d + e is a value in the range of greater than 0.05 and less than or equal to 1. .)   The first fluorescent material and the second fluorescent material are contained so that a weight ratio of the first fluorescent material: the second fluorescent material is 50:50 to 5:95. The phosphor according to claim 1.   A phosphor paste comprising the phosphor according to claim 1.   A phosphor layer obtained by applying a heat treatment after applying the phosphor paste according to claim 7 to a substrate.   The light emitting element which has the fluorescent substance in any one of Claims 1-6.

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