JP2009074077A - Phosphor, composition containing this phosphor, luminescent device, lighting system, and image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a 258 phosphor of improved persistence characteristic, a composition containing the phosphor, and a luminescent device, an image display and a lighting system that use the phosphor. <P>SOLUTION: The phosphor is represented by the following formula (I): Eu<SB>2x</SB>Tm<SB>2y</SB>(Mg, Ca, Sr, Ba)<SB>2-2x-2y</SB>Si<SB>5</SB>X<SB>8</SB>(I). In the formula (I), X represents one or more kinds of element selected from the group consisting of nitrogen and oxygen, and x and y each represents a positive number meeting either of the following, (i) and (ii): (i) 0< x ≤0.02, 0.5< x/y <2; (ii) 0.0005≤ x <0.005, x + y <0.025. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a red phosphor having a host crystal structure typified by (Mg, Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ , and more specifically has a long afterglow time and a phosphorescent property. The present invention relates to a phosphor, a phosphor-containing composition containing the phosphor, a light emitting device, a lighting device, and an image display device.

Nitride phosphors that emit red light when irradiated with near-ultraviolet and blue light and have a host crystal structure represented by (Mg, Ca, Sr, Ba) ₂ Si ₅ X ₈ (hereinafter referred to as “258” as appropriate). (Referred to as Patent Document 1).
Further, it is also known that the persistence of the 258 phosphor is improved by coexisting not only Eu conventionally known as an activator of the 258 phosphor but also a lanthanoid such as Tm. (See Patent Document 2).
Special table 2003-515665 gazette JP 2004-10786 A

Conventionally, phosphorescent phosphors have been widely used for fluorescent lamps, clock dials, etc., but La ₂ O ₂ S: Eu ^{3+ is the} only commonly known red phosphorescent phosphor. . In addition, regarding a light emitting device using a phosphor, even if the light emitting diode suddenly stops emitting light, if the phosphor used has a long persistence (has a phosphorescent property), a display is displayed. Since light emission can be sustained as an element or a light source, the appearance of a phosphor having such characteristics is desired.

  For this reason, as described above, although the investigation for improving the afterglow of the 258 phosphor emitting red light has been made, its performance is still insufficient from the viewpoint of afterglow, and 258 having higher afterglow. The appearance of phosphors has been desired.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a 258-based phosphor having high afterglow can be obtained by examining the amount ratio of Eu and Tm as activators. The present invention has been completed. That is, the gist of the present invention resides in a phosphor represented by the following formula (I).

Eu _2x Tm _2y (Mg, Ca, Sr, Ba) _2-2x-2y Si ₅ X ₈ (I)
(In the formula (I), X represents one or more elements selected from the group consisting of nitrogen and oxygen, and x and y are positive numbers satisfying any of the following (i) and (ii), respectively. Indicates.
(i) 0 <x ≦ 0.02
0.5 <x / y <2
(ii) 0.0005 ≦ x <0.005
x + y <0.025)

  Another gist of the present invention resides in a phosphor-containing composition containing the phosphor of the present invention and a liquid medium.

  Furthermore, another gist of the present invention includes a first light emitter and a second light emitter that emits visible light by irradiation of light from the first light emitter, and the second light emitter comprises: The present invention resides in a light-emitting device characterized by containing at least one phosphor of the present invention as a first phosphor.

  Furthermore, another gist of the present invention resides in an illumination device and an image display device having the light emitting device.

  Another gist of the present invention resides in a fluorescent paint containing the phosphor and a laminate formed by applying the fluorescent paint to a substrate.

  According to the present invention, a 258 phosphor with improved afterglow is provided. The phosphor is effectively applied to a use in which a phosphorescent phosphor such as a fluorescent lamp used for a dial of a clock, a road sign, an emergency exit, or the like is applied.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

  The relationship between the color name and the chromaticity coordinates in this specification is all based on the JIS standard (JIS Z8110 and Z8701).

Further, in the composition formula of the phosphors in this specification, each composition formula is delimited by a punctuation mark (,). In addition, when a plurality of elements are listed separated by commas (,), one or two or more of the listed elements may be included in any combination and composition. For example, the composition formula “(Ca, Sr, Ba) Al ₂ O ₄ : Eu” has “CaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “BaAl ₂ O ₄ : Eu”. If: the _{"Ca 1-x Sr x Al 2} O 4 Eu ": a _{"Sr 1-x Ba x Al 2} O 4 Eu ": the _{"Ca 1-x Ba x Al 2} O 4 Eu " _{"Ca 1-x-y Sr x} Ba y Al 2 O 4: Eu " and all assumed to generically indicated (in the above formula, 0 <x <1,0 <y <1,0 <X + y <1).

[1-1. Composition of phosphor]
The phosphor of the present invention is represented by the following formula (I).
Eu _2x Tm _2y (Mg, Ca, Sr, Ba) _2-2x-2y Si ₅ X ₈ (I)
(In the formula (I), X represents one or more elements selected from the group consisting of nitrogen and oxygen, and x and y are positive numbers satisfying any of the following (i) and (ii), respectively. Indicates.
(i) 0 <x ≦ 0.02
0.5 <x / y <2
(ii) 0.0005 ≦ x <0.005
x + y <0.025)

  In the above formula (I), X is an element selected from the group consisting of nitrogen (N) and oxygen (O). Any one of these elements may be contained alone, or two of them may be contained in any ratio. In addition to the above, as long as the performance is not affected, the halogen element May be partially contained. The halogen element content is usually 1 mol% or less with respect to the total X amount.

  Of these, X preferably contains at least N. Usually, N accounts for 90 mol% or more, preferably 97 mol% or more, more preferably 99 mol%, more preferably 99 mol%. This is the case of occupying at least 9 mol%, more preferably at least 99.5 mol%, and it is particularly preferable to use only N.

x represents the amount of Eu as an activator, and is usually a numerical value greater than zero. Among these, Preferably it is 0.0005 or more, More preferably, it is 0.001 or more, More preferably, it is 0.002 or more, More preferably, it is 0.0025 or more, Especially preferably, it is 0.003 or more. On the other hand, if the amount of Eu is too large, concentration quenching may occur. Therefore, it is usually 0.02 or less, preferably 0.010 or less, more preferably 0.009 or less, and further preferably 0.008 or less.
Among these, in particular, in the case where importance is placed on the initial afterglow intensity, it is preferably 0.0035 or more, more preferably 0.004 or more, more preferably 0.007 or less, and further preferably 0.0065 or less. is there. On the other hand, when more emphasis is placed on phosphorescence, it is preferably less than 0.005, more preferably 0.0045 or less, and even more preferably 0.0040 or less.

y represents the amount of Tm. In one embodiment of the present invention, the amount of y with respect to the amount of x is in a specific range, that is, the ratio of x: y is 2: 1 to 1: 2 (0.5 The range is <x / y <2).
Of these, x / y is preferably close to 1 in terms of initial afterglow intensity, specifically, preferably 0.75 or more, more preferably 0.8 or more, and even more preferably 0.9 or more. Moreover, 1.33 or less is preferable, More preferably, it is 1.25 or less, More preferably, it is 1.2 or less.

On the other hand, when emphasizing phosphorescence more, it is preferable to satisfy 0 <y <0.025 and x + y <0.025 in addition to the range of x.
Among these, y is preferably 0.02 or less, more preferably 0.0175 or less, further preferably 0.015 or less, particularly preferably 0.0125 or less, and preferably 0.002 or more, more preferably 0.003 or more, still more preferably 0.005 or more.
Further, x + y is preferably 0.024 or less, more preferably 0.022 or less, still more preferably 0.020 or less, particularly preferably 0.018 or less, and preferably 0.010 or more. More preferably, it is 0.012 or more.

[1-2. Characteristics of phosphor]
The phosphor of the present invention has the characteristics described below and has a function as a phosphor.

[1-2-1. Characteristics of emission spectrum]
The 258 phosphor of the present invention emits red light when excited by light in the near ultraviolet to blue region having a wavelength of 380 to 460 nm. Specifically, the emission peak wavelength λ _p (nm) in the emission spectrum when excited with light having a wavelength of 455 nm is usually 590 nm or more, more preferably 600 nm or more, and even more preferably 610 nm or more. . Further, the upper limit of the emission peak wavelength is usually 680 nm or less.

In addition, the phosphor has a full width at half maximum (hereinafter, abbreviated as “FWHM” where appropriate) in the above-described emission spectrum of usually 80 nm or more. Further, it is usually preferably in the range of less than 105 nm, especially 100 nm or less, and more preferably 95 nm or less.
If this half-value width is too wide, the color reproduction range of the image display device may be narrowed due to a decrease in color purity when used in an image display device.

  In order to excite the phosphor with light having a wavelength of 455 nm, for example, a GaN-based LED can be used. Moreover, the measurement of the emission spectrum of the phosphor of the present invention and the calculation of the emission peak wavelength, peak relative intensity and peak half width are performed using a fluorescence measuring apparatus such as FP-6500 manufactured by JASCO Corporation. Can do.

[1-2-2. Afterglow]
Light emission that continues even after irradiation of excitation light to the phosphor is stopped is what is called afterglow of the phosphor. This temporal change in afterglow intensity is called afterglow characteristics or afterglow, and there are two types of factors that constitute this afterglow: fluorescence lifetime and long afterglow (light storage). Among these, the latter can be evaluated by using a logarithmic display of a temporal change curve of afterglow intensity, for example, as shown in FIG. 2 of JP-A-10-188649.
The phosphor of the present invention exhibits excellent afterglow properties such that the rate of decrease in afterglow intensity per unit time is small in this temporal change curve of afterglow intensity.

[1-3. Method for producing phosphor]
The raw material, the phosphor production method, and the like for obtaining the phosphor of the present invention are not particularly limited, and may be appropriately combined in accordance with a known method. For example, the fluorescence of the above formula (I) It can manufacture by mixing the raw material compound containing the element which comprises a body (mixing process), and baking the obtained mixture (baking process).

[1-3-1. material]
Phosphor raw materials (ie, Eu source, Tm source, alkaline earth metal source, and Si source) used in the production of the phosphor of the present invention include metals, alloys, imide compounds, oxynitrides, nitriding of the respective elements. Among the compounds known as raw materials for phosphors such as oxides, oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates, halides, etc., reactivity, NO _x during firing, It may be selected as appropriate in consideration of the low generation amount of SO _{x and the} like.

Specific examples of the Eu source include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (C ₂ O ₄ ) ₃ .10H ₂ O, EuF ₃ , EuCl ₂ , EuCl ₃ , Eu (NO ₃ ) ₃ · _6H 2 O, EuN, EuNH and the like. Of these, oxides or halides are preferred.

  Specific examples of the Tm source include compounds in which Eu is replaced with Tm in each compound listed as a specific example of the Eu source.

Among the alkaline earth metal sources, specific examples of the Ba source include BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (C ₂ O ₄ ), Ba _{(OCOCH 3) 2, BaF 2} , BaCl 2, Ba 2 N, BaNH and the like. Of these, Ba ₂ N is preferable.

  Specific examples of the Mg source, the Ca source, and the Sr source include compounds in which Ba is replaced with an Mg element, a Ca element, or an Sr element in each of the compounds listed as specific examples of the Ba source.

As the Si source, it is preferable to use SiO ₂ or Si ₃ N ₄ . It is also possible to use a compound as a SiO _2. Specific examples of such a compound include SiO ₂ , H ₄ SiO ₄ , Si (OCOCH ₃ ) _{4 and the} like. Further, Si ₃ N ₄ is preferably one having a small particle diameter and high purity in terms of light emission efficiency from the viewpoint of reactivity. Furthermore, from the viewpoint of luminous efficiency, β-Si ₃ N ₄ is more preferable than α-Si ₃ N ₄ , and in particular, a material having a small content of carbon elements as impurities is more preferable. The smaller the carbon content, the better. However, the content is usually 0.01% by weight or more, usually 0.3% by weight or less, preferably 0.1% by weight or less, more preferably 0.05% or less. .

  In addition, the Eu source, the Tm source, the alkaline earth metal source, and the Si source described above may each be used alone or in combination of two or more in any combination and ratio.

  In addition, the X source is usually supplied as an anion component of the Eu source, Tm source, alkaline earth metal source, and Si source, or as a component contained in the firing atmosphere when the phosphor is manufactured.

  Here, as a raw material to be used, a stoichiometric amount of a raw material may be mixed based on the composition formula of the target phosphor, but an alkaline earth metal source compound is used with respect to the stoichiometric amount. Usually, if it is used excessively in the range of 50% by weight or less, preferably 30% by weight or less, more preferably 20% by weight or less, a flux effect is obtained, which is preferable.

[1-3-2. Production method of phosphor: mixing step]
The phosphor raw materials are weighed so that the target composition can be obtained, mixed thoroughly using a ball mill, etc., filled into a crucible, fired at a predetermined temperature and in a predetermined atmosphere, and the fired product is pulverized and washed. The phosphor of the invention can be obtained.

  The mixing method is not particularly limited. Specifically, for example, a dry pulverizer such as a hammer mill, a roll mill, a ball mill, or a jet mill, or pulverization using a mortar and pestle, for example, a ribbon blender, a V-type Examples thereof include a dry mixing method in which a blender such as a blender or a Henschel mixer, or mixing using a mortar and a pestle is combined and the above-mentioned raw materials are pulverized and mixed.

Mixing of the raw materials is preferably performed by mixer mixing in a moisture-controlled N ₂ glove box so that the nitride raw materials are not deteriorated by moisture. The moisture in the atmosphere of the work place where mixing is performed should be 10,000 ppm or less, preferably 1000 ppm or less, more preferably 10 ppm or less, and still more preferably 1 ppm or less. Also, oxygen is 1% or less, preferably 10,000 ppm or less, more preferably 100 ppm or less, and still more preferably 10 ppm or less.

[1-3-3. Production method of phosphor: firing step]
The obtained mixture is filled in a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each raw material. Examples of the material of the heat-resistant container used at the time of firing include ceramics such as alumina, quartz, boron nitride, silicon nitride, silicon carbide, magnesium, mullite, platinum, molybdenum, tungsten, tantalum, niobium, iridium, rhodium, and the like. Examples thereof include metals, alloys containing them as main components, and carbon (graphite).

  Examples of such heat-resistant containers are preferably boron nitride, alumina, silicon nitride, silicon carbide, platinum, molybdenum, tungsten, and tantalum heat-resistant containers, more preferably boron nitride. belongs to.

  Regarding the firing step, the fired powder usually sinters at a firing temperature exceeding 2000 ° C., and the light emission intensity may be lowered. However, at a firing temperature of about 1700-1800 ° C., a powder with good crystallinity is obtained. can get. Therefore, the firing temperature for producing the phosphor of the present invention is usually 1000 ° C. or higher, preferably 1300 ° C. or higher, more preferably 1500 ° C. or higher, and usually 1900 ° C. or lower, preferably 1850. The temperature is not higher than ° C, more preferably not higher than 1800 ° C.

Although it does not restrict | limit especially as a baking atmosphere, Usually, it carries out in inert gas atmosphere or reducing atmosphere. Here, since it is preferable that the valence of Eu, which is an activating element, be more divalent, a reducing atmosphere is preferable. In addition, only 1 type may be used for an inert gas and reducing gas, and 2 or more types may be used together by arbitrary combinations and a ratio.
Examples of the inert gas and the reducing gas include carbon monoxide, hydrogen, nitrogen, argon, and the like. Of these, a nitrogen gas atmosphere is preferable, and a hydrogen gas-containing nitrogen gas atmosphere is more preferable. As the nitrogen (N ₂ ) gas, it is preferable to use a purity of 99.9% or more. When using hydrogen-containing nitrogen, it is preferable to reduce the oxygen concentration in the electric furnace to 20 ppm or less. Furthermore, the hydrogen content in the atmosphere is preferably 1% by volume or more, more preferably 2% by volume or more, and preferably 5% by volume or less. This is because if the hydrogen content in the atmosphere is too high, the safety may decrease, and if it is too low, a sufficient reducing atmosphere may not be achieved.

  Further, the inert gas and the reducing gas may be introduced before the start of temperature increase, may be introduced during the temperature increase, or may be introduced when the firing temperature is reached, It is preferable to introduce it in the middle of raising the temperature.

  The firing time is usually 0.5 hours or longer, preferably 1 hour or longer, although it varies depending on the temperature and pressure during firing. Moreover, it is 100 hours or less normally, Preferably it is 50 hours or less, More preferably, it is 24 hours or less, More preferably, it is 12 hours or less.

The pressure during firing is not particularly limited differs depending firing temperature, etc., usually 1 × ¹⁰ -5 Pa or more, preferably 1 × ¹⁰ -3 Pa or more, more preferably 0.01MPa or more, more preferably 0. The upper limit is usually 5 GPa or less, preferably 1 GPa or less, more preferably 200 MPa or less, and still more preferably 100 MPa or less. Among these, the atmospheric pressure to about 1 MPa is industrially preferable in terms of cost and labor.

[1-3-4. flux]
In the firing step, a flux may coexist in the reaction system from the viewpoint of growing good crystals. The type of flux is not particularly limited, _{examples, NH 4 Cl, NH 4 F} · HF , such as ammonium _halide; NaCO 3, alkali metal carbonates such as _{LiCO 3; LiCl, NaCl, KCl} , CsCl, LiF, Alkali metal halides such as NaF, KF and CsF; Alkaline earth metal halides such as CaCl ₂ , BaCl ₂ , SrCl ₂ , CaF ₂ , BaF ₂ and SrF ₂ ; Alkaline earth metal oxides such as CaO, SrO and BaO Boron oxides such as B ₂ O ₃ , H ₃ BO ₃ , NaB ₄ O ₇ , boric acid and borate compounds; Phosphate compounds such as Li ₃ PO ₄ and NH ₄ H ₂ PO ₄ ; AlF ₃ aluminum halides _etc.; ZnCl 2, zinc halide such as ZnF _2, zinc oxide, zinc compounds such as zinc sulfide; B Periodic Table Group 15 element compound such as _{2 O 3; Li 3 N,} Ca 3 N 2, Sr 3 N 2, Ba 3 N 2, BN alkali metal, alkaline earth metal or the periodic table Group 13 element such as such as And nitrides thereof. Of these, preferred are halides, and among these, alkali metal halides, alkaline earth metal halides, and Zn halides are preferred. Of these halides, fluorides and chlorides are preferred. Some fluxes also serve as an alkaline earth metal source.

  The amount of flux used varies depending on the type of raw material, the material of the flux, etc., but is usually 0.01% by weight with respect to the total weight of the phosphor raw material or the total weight of the phosphor when the flux is added after firing. Above, preferably 0.1% by weight or more, more preferably 1% by weight or more, usually 20% by weight or less, and further preferably 10% by weight or less. If the amount of flux used is too small, the effect of the flux will not appear, and if the amount of flux used is too large, the flux effect will be saturated, or it will be incorporated into the host crystal and change the emission color or cause a decrease in brightness There is. These fluxes may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

[1-3-5. Primary firing and secondary firing]
The firing step may be divided into primary firing and secondary firing, and the raw material mixture obtained by the mixing step may be first fired first, and then pulverized again with a ball mill or the like, followed by secondary firing.

  Here, the temperature of the primary firing at the time of producing the phosphor of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but for the purpose of preventing side reactions such as hydrolysis of intermediate nitride during firing. The primary firing temperature is preferably not too low, and is usually 1000 ° C. or higher, preferably 1300 ° C. or higher, and usually 1800 ° C. or lower, preferably 1700 ° C. or lower, more preferably 1600 ° C. or lower.

  The time for the primary firing is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 hour or longer, preferably 2 hours or longer, and usually 100 hours or shorter, preferably 50 hours or shorter, more preferably 24 hours or shorter. More preferably, it is 12 hours or less.

  The conditions such as the temperature and time of the secondary firing are basically the same as the conditions described in the above-mentioned firing step column.

  The flux may be mixed before the primary firing or may be mixed before the secondary firing. Also, the firing conditions such as the atmosphere may be changed between the primary firing and the secondary firing.

[1-3-6. Post-processing]
After the heat treatment in the above-described firing step, a known process such as washing, drying, pulverization, and classification is performed as necessary to obtain a phosphor.

[1-4. Use of phosphor]
The phosphor of the present invention can be used for any application. In particular, by utilizing the characteristic that it can be excited by blue or near-ultraviolet light, various light emitting devices (for example, “the light emitting device of the present invention” described later) are used. ). In this case, light emitting devices having various emission colors can be manufactured by adjusting the types and usage ratios of the phosphors to be combined. Since the phosphor of the present invention is a red phosphor, for example, a white light emitting device can be manufactured by combining an excitation light source that emits blue light and a phosphor that emits green fluorescence (green phosphor). The luminescent color in this case can be changed to a preferred luminescent color by adjusting the emission wavelength of the phosphor of the present invention or the green phosphor and the amount of mixture thereof. A white light emitting device can also be manufactured by combining the phosphor of the present invention with a phosphor emitting blue fluorescence (blue phosphor) and a green phosphor in an excitation light source that emits near-ultraviolet light.

  In addition, the emission color of the light emitting device is not limited to white, and if necessary, yellow phosphor (phosphor emitting yellow fluorescence), blue phosphor, orange to red phosphor, other types of green phosphor, etc. By combining the above and adjusting the type and use ratio of the phosphor, a light emitting device that emits light of any color can be manufactured. The light-emitting device thus obtained can be used as a light-emitting portion (particularly a liquid crystal backlight) or an illumination device of an image display device.

  In addition to this, taking advantage of the long afterglow property, it has been replaced with sulfide-based phosphorescent phosphors that have been used in the past, for example, various instruments, dials for night clocks, safety sign boards, etc. It can also be used for various applications. Specifically, display of vehicles such as airplanes, boats, cars, bicycles; road traffic signs, lane indications, indications on guardrails, indications of fishery buoys, etc., indications from gates to entrances, to helmets Display on various signs on display, etc .; Outdoor display such as signs / buildings, etc .; Indoor display such as electrical appliance switches, etc .; Display of various keys and keyholes in homes, cars, bicycles, etc .; Writing instruments, night light Stationery such as inks, maps, and constellation charts; Toys such as jigsaw puzzles; Sports balls; Backlights for liquid crystals (used for watches and the like); Substitutes for isotopes used for discharge tubes, and the like.

[2. Phosphor-containing composition]
The phosphor of the present invention can be used by mixing with a liquid medium. In particular, when the phosphor of the present invention is used for applications such as a light emitting device, it is preferably used in a form dispersed in a liquid medium. The phosphor of the present invention dispersed in a liquid medium will be referred to as “the phosphor-containing composition of the present invention” as appropriate.

[2-1. Phosphor]
There is no restriction | limiting in the kind of fluorescent substance of this invention contained in the fluorescent substance containing composition of this invention, It can select arbitrarily from what was mentioned above. Moreover, the fluorescent substance of this invention contained in the fluorescent substance containing composition of this invention may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
Furthermore, you may make the fluorescent substance containing composition of this invention contain fluorescent substances other than the fluorescent substance of this invention, unless the effect of this invention is impaired remarkably.

[2-1-1. Phosphor content]
The phosphor content in the phosphor-containing composition of the present invention is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 50% by weight or more based on the entire phosphor-containing composition of the present invention, Preferably it is 75 weight% or more, Usually 99 weight% or less, Preferably it is 95 weight% or less. The proportion of the phosphor of the present invention in the phosphor in the phosphor-containing composition is also arbitrary, but is usually 5% by weight or more, preferably 15% by weight or more, and usually 100% by weight or less. If the phosphor content in the phosphor-containing composition is too large, the fluidity of the phosphor-containing composition may be poor and may be difficult to handle. If the phosphor content is too small, the emission intensity tends to decrease.

[2-2. Liquid medium]
The liquid medium used in the phosphor-containing composition of the present invention is not particularly limited as long as the performance of the phosphor is not impaired within the intended range. For example, any inorganic material and / or organic material may be used as long as it exhibits liquid properties under the desired use conditions, suitably disperses the phosphor of the present invention, and does not cause an undesirable reaction. it can.

  As the inorganic material, for example, a solution obtained by hydrolytic polymerization of a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination thereof is solidified (for example, a siloxane bond). Inorganic materials having

Examples of organic materials include thermoplastic resins, thermosetting resins, and photocurable resins. Specifically, for example, methacrylic resin such as polymethylmethacrylate; styrene resin such as polystyrene and styrene-acrylonitrile copolymer; polycarbonate resin; polyester resin; phenoxy resin; butyral resin; polyvinyl alcohol; Cellulose resins such as cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins.

Among these, particularly when using a phosphor for a high-power light-emitting device such as illumination, it is preferable to use a silicon-containing compound for the purpose of heat resistance and light resistance.
The silicon-containing compound refers to a compound having a silicon atom in the molecule, for example, an organic material (silicone material) such as polyorganosiloxane, an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, and borosilicate, Examples thereof include glass materials such as phosphosilicate and alkali silicate. Among these, from the viewpoint of ease of handling and the like, silicone materials, particularly those described in JP-A Nos. 2007-129297 to 112975 and JP-A No. 2007-19459 are preferable.

[2-2-1. Content of liquid medium]
The content of the liquid medium is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 50% by weight or more, preferably 75% by weight or more, based on the entire phosphor-containing composition of the present invention. It is 99 weight% or less, Preferably it is 95 weight% or less. When the amount of the liquid medium is large, no particular problem occurs. However, in order to obtain a desired chromaticity coordinate, color rendering index, luminous efficiency, etc. in the case of a semiconductor light emitting device, it is usually at a blending ratio as described above. It is desirable to use a liquid medium. On the other hand, if the amount of the liquid medium is too small, there is a possibility that the liquid medium is not fluid and difficult to handle.

  The liquid medium mainly has a role as a binder in the phosphor-containing composition of the present invention. The liquid medium may be used alone or in combination of two or more in any combination and ratio. For example, when a silicon-containing compound is used for the purpose of heat resistance, light resistance, etc., other thermosetting resins such as an epoxy resin may be contained to the extent that the durability of the silicon-containing compound is not impaired. In this case, the content of the other thermosetting resin is usually 25% by weight or less, preferably 10% by weight or less, based on the total amount of the liquid medium as the binder.

[2-3. Other ingredients]
In addition, in the phosphor-containing composition of the present invention, in addition to the phosphor and the liquid medium, other components, for example, a metal oxide for adjusting the refractive index described later, as long as the effects of the present invention are not significantly impaired, You may contain additives, such as a spreading | diffusion agent, a filler, a viscosity modifier, and an ultraviolet absorber. Moreover, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

[3. Light emitting device]
The light-emitting device of the present invention is a light-emitting device that includes a first light-emitting body and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body. Includes at least one of the phosphors of the present invention as a first phosphor, has a first light emitter that can serve as an excitation light source, and uses the phosphor of the present invention as a second light emitter. As long as it contains the 1st fluorescent substance containing at least 1 or more types, what is necessary is just to take a well-known apparatus structure arbitrarily.

[3-1. Configuration of Light Emitting Device (First Light Emitter)]
The first illuminant emits light having a wavelength of usually 200 nm or more. Specifically, the peak is usually 300 nm or more, more preferably 330 nm or more, still more preferably 360 nm or more, and usually a peak of 420 nm or less. A near-ultraviolet illuminant having an emission wavelength or a blue illuminant having a peak emission wavelength of usually 420 nm or more, more preferably 430 nm or more, and usually 500 nm or less, preferably 480 nm or less is used.

As the first light emitter, a semiconductor light emitting element is generally used, and specifically, a light emitting LED, a semiconductor laser diode (hereinafter abbreviated as “LD” as appropriate), or the like can be used. . In addition, as a light-emitting body which can be used as a 1st light-emitting body, an organic electroluminescent light emitting element, an inorganic electroluminescent light emitting element, etc. are mentioned, for example. However, what can be used as a 1st light-emitting body is not restricted to what is illustrated by this specification.
Among these, as the first light emitter, a GaN-based LED or LD using a GaN-based compound semiconductor is preferable.

[3-2. Configuration of light emitting device (second light emitter)]
The second light emitter in the light emitting device of the present invention is a light emitter that emits visible light when irradiated with light from the first light emitter described above, and the phosphor of the present invention described above (red) as the first phosphor. And a second phosphor (a green phosphor, a blue phosphor, a yellow phosphor, etc.) to be described later as appropriate depending on the application. Further, for example, the second light emitter is configured by dispersing the first and second phosphors in a sealing material.

[3-2-1. First phosphor]
The second light emitter in the light emitting device of the present invention contains at least the above-described phosphor of the present invention as the first phosphor. Any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio.
In addition to the phosphor of the present invention, a phosphor that emits fluorescence of the same color as the phosphor of the present invention (same color combined phosphor) may be used as the first phosphor. Since the phosphor of the present invention is usually a red phosphor, other types of red phosphors can be used together with the phosphor of the present invention as the first phosphor.

  The weight median diameter of the first phosphor used in the light emitting device of the present invention is usually in the range of 10 μm or more, especially 12 μm or more, and usually 30 μm or less, especially 25 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur.

(Orange to red phosphor)
When an orange or red phosphor is used in combination with the phosphor of the present invention, any orange or red phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the orange to red phosphor is usually in the wavelength range of 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. Is preferred.

Such an orange to red phosphor is composed of, for example, grown particles having a substantially spherical shape as a regular crystal growth shape, and emits light in a red region (Y, La, Gd, Lu) ₂ O ₂ S. : Europium activated rare earth oxychalcogenide phosphor represented by Eu.
Furthermore, an oxynitride and / or an oxysulfide containing at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, W, and Mo described in JP-A-2004-300247 A phosphor containing an oxynitride having an alpha sialon structure in which a part or all of the Al element is substituted with a Ga element can also be used in the present invention. These are phosphors containing oxynitride and / or oxysulfide.

In addition, as the orange to red phosphor, Eu such as (La, Y) ₂ O ₂ S: Eu, (La, Y) ₂ O ₂ S: Eu, (Mg, Ti, Nb, Ta, Ga) is used. Activated oxysulfide phosphor, Eu-activated oxide phosphor such as Y (V, P) O ₄ : Eu, Y ₂ O ₃ : Eu, (Ba, Mg) ₂ SiO ₄ : Eu, Mn, (Ba , Sr, Ca, Mg) ₂ SiO ₄ : Eu, Mn activated silicate phosphor such as Eu, Mn, LiW ₂ O ₈ : Eu, LiW ₂ O ₈ : Eu, Sm, Eu ₂ W ₂ O ₉ , Eu ₂ W ₂ O ₉ : Nb, Eu ₂ W ₂ O ₉ : Eu-activated tungstate phosphor such as Sm, (Ca, Sr) S: Eu-activated sulfide phosphor such as Eu, YAlO ₃ : Eu, etc. Eu-activated aluminate _{phosphor, Ca 2 Y 8 (SiO 4} ) 6 O 2: Eu, LiY 9 _{SiO 4) 6 O 2: Eu} , (Sr, Ba, Ca) 3 SiO 5: Eu, Sr 2 BaSiO 5: Eu -activated silicate phosphors such as _{Eu, (Y, Gd) 3} Al 5 O 12: Ce , (Tb, Gd) ₃ Al ₅ O ₁₂ : Ce-activated aluminate phosphor such as Ce, (Mg, Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Mg, Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Eu-activated oxide such as Eu, nitride or oxynitride phosphor, Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Ce-activated oxide such as Ce, nitride or oxynitride phosphor, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl _2: Eu, Eu such as Mn, Mn-activated halophosphate _phosphor, Ba 3 MgSi ₂ O _{8 Eu, Mn, (Ba, Sr} , Ca, Mg) 3 (Zn, Mg) Si 2 O 8: Eu, Eu such as Mn, Mn-activated silicate phosphor, 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn-activated germanate phosphor such as Mn, Eu-activated oxynitride phosphor such as Eu-activated α sialon, (Gd, Y, Lu, La) ₂ O ₃ : Eu, Bi such as Eu, Bi Activated oxide phosphor, (Gd, Y, Lu, La) ₂ O ₂ S: Eu, Bi activated oxysulfide phosphor such as Eu, Bi, (Gd, Y, Lu, La) VO ₄ : Eu Eu, Bi activated vanadate phosphors such as Bi, Bi, etc., SrY ₂ S ₄ : Eu, Ce activated sulfide phosphors such as Eu, Ce, and Ce activated sulfide phosphors such as CaLa ₂ S ₄ : Ce _{, (Ba, Sr, Ca)} MgP 2 O 7: Eu, Mn, (Sr, Ca, Ba, Mg, Zn) P ₂ O _7: Eu, Eu such as Mn, Mn-activated phosphate _{phosphor, (Y, Lu) 2 WO} 6: Eu, Eu such as Mo, Mo-activated tungstate phosphor, (Ba, Sr _{, Ca) a Si B N C} : Eu, Ce ( where, a, B, C represents an integer of 1 or more. Eu, Ce-activated nitride phosphors such as (Ca, Sr, Ba, Mg) ₁₀ (PO ₄ ) ₆ (F, Cl, Br, OH): Eu, Mn-activated halophosphoric acid such as Eu, Mn _{phosphor, ((Y, Lu, Gd} , Tb) 1-m-n Sc m Ce n) 2 (Ca, Mg) 1-r (Mg, Zn) 2 + r Si z-q Ge q O 12 + δ , etc. Ce It is also possible to use an activated silicate phosphor or the like.

  Examples of red phosphors include β-diketonates, β-diketones, aromatic carboxylic acids, red organic phosphors composed of rare earth element ion complexes having an anion such as Bronsted acid as a ligand, and perylene pigments (for example, Dibenzo {[f, f ′]-4,4 ′, 7,7′-tetraphenyl} diindeno [1,2,3-cd: 1 ′, 2 ′, 3′-lm] perylene), anthraquinone pigment, Lake pigments, azo pigments, quinacridone pigments, anthracene pigments, isoindoline pigments, isoindolinone pigments, phthalocyanine pigments, triphenylmethane basic dyes, indanthrone pigments, indophenol pigments, It is also possible to use a cyanine pigment or a dioxazine pigment.

Among these, as the red phosphor, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) ) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, (La, Y) ₂ O ₂ S: Eu, (La, Y) ₂ O ₂ S: Eu, (Mg, Ti, Nb, Ta, Ga) or Eu complex is preferably included, and (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, (La, Y _{) 2 O 2 S: Eu,} (Mg, Ti, Nb, Ta, Ga) or _{(La, Y) 2 O 2} S: Eu, also Ku is more preferably containing Eu _{(dibenzoylmethane)} 3 · 1,10-beta-diketone Eu complex or carboxylic acid Eu complex phenanthroline complex, _{etc., (Sr, Ca) AlSiN 3} : Eu, (La, Y) ₂ O ₂ S: Eu or (La, Y) ₂ O ₂ S: Eu, (Mg, Ti, Nb, Ta, Ga) is more preferable, and (La, Y) ₂ O from the viewpoint of long persistence. ₂ S: Eu, (Mg, Ti, Nb, Ta, Ga) is particularly preferred.
Moreover, among the above examples, (Sr, Ba) ₃ SiO ₅ : Eu is preferable as the orange phosphor.

[3-2-2. Second phosphor]
The second light emitter in the light emitting device of the present invention may contain a phosphor (that is, a second phosphor) in addition to the first phosphor described above, depending on the application. The second phosphor is a phosphor having an emission wavelength different from that of the first phosphor. Usually, since these second phosphors are used to adjust the color tone of light emitted from the second light emitter, the second phosphor emits fluorescence having a color different from that of the first phosphor. Often phosphors are used. In the present invention, as described above, since the phosphor of the present invention, which is usually a red phosphor, is used as the first phosphor, examples of the second phosphor include a green phosphor, a blue phosphor, and a yellow phosphor. A phosphor other than a red phosphor such as a body is used.

  The weight median diameter of the second phosphor used in the light emitting device of the present invention is usually in the range of 10 μm or more, especially 12 μm or more, and usually 30 μm or less, especially 25 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur.

(Green phosphor)
When the green phosphor is used, any green phosphor can be used as long as the effect of the present invention is not significantly impaired. At this time, the emission peak wavelength of the green phosphor is usually larger than 500 nm, preferably 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 540 nm or less, and further preferably 535 nm or less. If this emission peak wavelength is too short, it tends to be bluish, while if it is too long, it tends to be yellowish, and any of these may be detrimental to the characteristics of green light.

Specifically, the green phosphor is composed of, for example, fractured particles having a fractured surface, and emits a green region (Mg, Ca, Sr, Ba) with europium represented by (Si ₂ O ₂ N ₂ : Eu). Examples include active alkaline earth silicon oxynitride phosphors.
Other green phosphors include Sr ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) Al ₂ O ₄ : Eu, SrAl ₂ O ₄ : Eu, (Dy, Nd, Sm), Sr ₄ Al ₁₄ O ₂₅ : Eu-activated aluminate phosphor such as Eu (Dy, Nd, Sm), (Sr, Ba) Al ₂ Si ₂ O ₈ : Eu, (Ba, Mg) ₂ SiO ₄ : Eu, Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu, (Ba, Ca, Sr, Mg) ₉ (Sc, Y, Lu , Gd) ₂ (Si, Ge) ₆ O ₂₄ : Eu-activated silicate phosphor such as Eu, Y ₂ SiO ₅ : Ce, Tb-activated silicate phosphor such as Ce and Tb, Sr ₂ P ₂ O ₇ -Sr ₂ B ₂ O _5: Eu-activated borate phosphate phosphors such as Eu, S _{r 2 Si 3 O 8 -2SrCl 2} : Eu activated halo silicate phosphor such as _Eu, Zn 2 _SiO 4: Mn-activated silicate phosphors such as _{Mn, CeMgAl 11 O 19: Tb} , Y 3 Al 5 O ₁₂ : Tb-activated aluminate phosphor such as Tb, Tb-activated silicate phosphor such as Ca ₂ Y ₈ (SiO ₄ ) ₆ O ₂ : Tb, La ₃ Ga ₅ SiO ₁₄ : Tb, (Sr, Ba , Ca) Ga ₂ S ₄ : Eu, Tb, Sm activated thiogallate phosphor such as Eu, Tb, Sm, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Y, Ga, Tb, La, Sm, Pr, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce-activated aluminate phosphor such as Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce-activated silicate fluorescence such as Ce Bodies, Ce activated oxide phosphors such as CaSc ₂ O ₄ : Ce, Eu activated oxynitride phosphors such as Eu activated β sialon, BaMgAl ₁₀ O ₁₇ : Eu, Mn activated aluminas such as Eu and Mn Acid phosphor, (La, Gd, Y) ₂ O ₂ S: Tb activated oxysulfide phosphor such as Tb, LaPO ₄ : Ce, Tb activated phosphate phosphor such as Ce, Tb, ZnS: Cu, Al, ZnS: Cu, Au, sulfide phosphor such as _{Al, (Y, Ga, Lu} , Sc, La) BO 3: Ce, Tb, Na 2 Gd 2 B 2 O 7: Ce, Tb, ( Ba, Sr) ₂ (Ca, Mg, Zn) B ₂ O ₆ : Ce, Tb-activated borate phosphors such as K, Ce, Tb, Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu, Mn, etc. Eu, Mn activated halosilicate phosphor, (Sr, Ca, Ba) (Al, Ga, In) ₂ S ₄ : Eu-activated thioaluminate phosphor such as Eu or thiogallate phosphor, (Ca, Sr) ₈ (Mg, Zn) (SiO ₄ ) ₄ Cl ₂ : Eu, Mn-activated halo such as Eu, Mn Silicate phosphor, M ₃ Si ₆ O ₉ N ₄ : Eu, M ₃ Si ₆ O ₁₂ N ₂ : Eu (where M represents an alkaline earth metal element). It is also possible to use Eu-activated oxynitride phosphors such as SrAl ₂ O ₄ : Eu, (Dy, Nd, Sm) or Sr ₄ Al ₁₄ O _{25 from} the viewpoint of long persistence. : Eu (Dy, Nd, Sm) is preferable.

  In addition, as the green phosphor, it is also possible to use a pyridine-phthalimide condensed derivative, a benzoxazinone-based, a quinazolinone-based, a coumarin-based, a quinophthalone-based, a nartaric imide-based fluorescent dye, or an organic phosphor such as a terbium complex. is there.

  Any of the green phosphors exemplified above may be used alone, or two or more may be used in any combination and ratio.

(Blue phosphor)
When a blue phosphor is used as the second phosphor, any blue phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the blue phosphor is usually 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, preferably 480 nm or less, more preferably 470 nm or less, and further preferably 460 nm or less. It is preferable to be in the wavelength range.

Such a blue phosphor is composed of growing particles having a substantially hexagonal shape as a regular crystal growth shape, and europium represented by (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu that emits light in a blue region. The activated barium magnesium aluminate phosphor is composed of growing particles having a substantially spherical shape as a regular crystal growth shape, and emits light in the blue region (Mg, Ca, Sr, Ba) ₅ (PO ₄ ) ₃ ( Cl, F): a europium-activated calcium halophosphate phosphor represented by Eu, composed of grown particles having a substantially cubic shape as a regular crystal growth shape, and emits light in a blue region (Ca, Sr, Ba) ₂ Examples include europium-activated alkaline earth chloroborate phosphors represented by B ₅ O ₉ Cl: Eu.

In addition, as the blue phosphor, Sn-activated phosphate phosphors such as Sr ₂ P ₂ O ₇ : Sn, BaMgAl ₁₀ O ₁₇ : Eu, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Tb, Sm, BaAl ₈ O ₁₃ : Eu-activated aluminate phosphor such as Eu, SrGa ₂ S ₄ : Ce, Ca-activated thiogallate phosphor such as CaGa ₂ S ₄ : Ce, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn activated aluminate phosphor such as Eu, Mn, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba , Sr, Ca) ₅ (PO ₄ ) ₃ (Cl, F, Br, OH): Eu-activated halophosphate phosphors such as Eu, Mn, Sb, BaAl ₂ Si ₂ O ₈ : Eu, (Sr, Ba ) ₃ M _{Si 2 O 8: Eu, (} Ca, Sr, Ba) 3 MgSi 2 O 8: Eu, (Dy, Cl, Br) Eu -activated silicate phosphors such _{as, Sr 2 P 2 O 7:} Eu such as Eu Activated phosphate phosphor, sulfide phosphor such as ZnS: Ag, ZnS: Ag, Al, Ce activated silicate phosphor such as Y ₂ SiO ₅ : Ce, tungstate phosphor such as CaWO ₄ (Ba, Sr, Ca) BPO ₅ : Eu, Mn, (Sr, Ca) ₁₀ (PO ₄ ) ₆ · nB ₂ O ₃ : Eu, 2SrO · 0.84P ₂ O ₅ · 0.16B ₂ O ₃ : Eu Eu, Mn activated boric acid phosphor phosphor such as Sr ₂ Si ₃ O ₈ · 2SrCl ₂ : Eu activated halosilicate phosphor such as Eu, SrSi ₉ Al ₁₉ ON ₃₁ : Eu, EuSi ₉ Al ₁₉ ON Eu Tsukekatsusan nitride phosphor such as _31, La _{-E Ce e Al (Si 6-} f Al f) (N 10-f O f) ( where, e and f are each a number satisfying 0 ≦ e ≦ 1,0 ≦ f ≦ 6.), _{la 1-g-h Ce g} Ca h Al (Si 6-i Al i) (N 10-i O i) ( wherein, g, h, and i, respectively, 0 ≦ g ≦ 1,0 ≦ h It is also possible to use Ce-activated oxynitride phosphors such as ≦ 1, 0 ≦ i ≦ 6.

  In addition, as the blue phosphor, for example, naphthalic acid imide-based, benzoxazole-based, styryl-based, coumarin-based, pyralizone-based, triazole-based compound fluorescent dyes, thulium complexes and other organic phosphors can be used. .

Among the above examples, as the blue phosphor, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, It preferably contains (Ba, Ca, Mg, Sr) ₂ SiO ₄ : Eu or (Ca, Sr, Ba) ₃ MgSi ₂ O ₈ : Eu, (Dy, Cl, Br), and (Ca, Sr, Ba). MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu or (Ca, Sr , Ba) ₃ MgSi ₂ O ₈ : Eu, (Dy, Cl, Br) is more preferable, BaMgAl ₁₀ O ₁₇ : Eu, Sr ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, Ba ₃ MgSi ₂ O ₈ : E It is more preferable to contain u or (Ca, Sr, Ba) ₃ MgSi ₂ O ₈ : Eu, (Dy, Cl, Br). Moreover, these lighting applications and as display applications _{(Sr, Ca, Ba, Mg} ) 10 (PO 4) 6 Cl 2: Eu or _{(Ca, Sr, Ba) MgAl} 10 O 17: Eu is particularly preferred, long afterglow From the viewpoint of optical properties, (Ca, Sr, Ba) ₃ MgSi ₂ O ₈ : Eu, (Dy, Cl, Br) is particularly preferable.

  Any of the blue phosphors exemplified above may be used alone, or two or more may be used in any combination and ratio.

(Yellow phosphor)
When a yellow phosphor is used as the second phosphor, any yellow phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the yellow phosphor is usually in the wavelength range of 530 nm or more, preferably 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, preferably 600 nm or less, more preferably 580 nm or less. Is preferred.

Examples of such yellow phosphors include various oxide-based, nitride-based, oxynitride-based, sulfide-based, and oxysulfide-based phosphors.
In particular, RE ₃ M ′ ₅ O ₁₂ : Ce (where RE represents at least one element selected from the group consisting of Y, Tb, Gd, Lu, and Sm, and M ′ represents Al, Ga, And at least one element selected from the group consisting of Sc and M ^a ₃ M ^b ₂ M ^c ₃ O ₁₂ : Ce (where M ^a is a divalent metal element, M ^b is a trivalent element) metal element, ^{M c} represents a tetravalent metal element) garnet phosphor having a garnet structure represented by ^{_{like, AE 2 M d O 4:}} . Eu ( where, AE is, Ba, Sr, Ca, Mg And at least one element selected from the group consisting of Zn, M ^d represents Si and / or Ge, etc.), etc., and constituent elements of the phosphors of these systems A portion of the oxygen in the atmosphere was replaced by nitrogen Nitride-based fluorescent material, AEAlSiN _3: Ce (., Where, AE is, Ba, Sr, Ca, represents at least one element selected from the group consisting of Mg and Zn) nitride having CaAlSiN ₃ structures such as And phosphors activated with Ce, such as phosphors based on phosphors.

In addition, as yellow phosphors, sulfide-based fluorescence such as CaGa ₂ S ₄ : Eu, (Ca, Sr) Ga ₂ S ₄ : Eu, (Ca, Sr) (Ga, Al) ₂ S ₄ : Eu, etc. Body, Cax (Si, Al) ₁₂ (O, N) ₁₆ : phosphor activated by Eu such as oxynitride-based phosphor having a SiAlON structure such as Eu, (M _1-a-b Eu _a Mn _b ) ₂ (BO ₃ ) _1-p (PO ₄ ) _p X (where M represents one or more elements selected from the group consisting of Ca, Sr, and Ba, and X represents F, Cl, and Br) Represents one or more elements selected from the group consisting of: a, b, and p are 0.001 ≦ a ≦ 0.3, 0 ≦ b ≦ 0.3, and 0 ≦ p ≦ 0.2, respectively. Eu activated or Eu, Mn co-activated halogenated borate phosphor, alkaline earth metal element It is also possible to use a rare earth-activated珪窒halide phosphor or the like having a good La ₃ Si ₆ N ₁₁ structure also contain.

  Examples of the yellow phosphor include fluorescent dyes such as brilliant sulfoflavine FF (Colour Index Number 56205), basic yellow HG (Colour Index Number 46040), eosine (Colour Index Number 45380), rhodamine 6G (Colour Index Number 45160), and the like. Etc. can also be used.

  Any one of the yellow phosphors exemplified above may be used alone, or two or more may be used in any combination and ratio.

(Other matters concerning the second phosphor)
As said 2nd fluorescent substance, 1 type of fluorescent substance may be used independently, and 2 or more types of fluorescent substance may be used together by arbitrary combinations and a ratio. Further, the ratio between the first phosphor and the second phosphor is also arbitrary as long as the effects of the present invention are not significantly impaired. Therefore, the usage amount of the second phosphor, the combination of phosphors used as the second phosphor, and the ratio thereof may be arbitrarily set according to the use of the light emitting device.

For example, when the light emitting device of the present invention is configured as a red light emitting device, only the first phosphor (red phosphor) may be used, and the use of the second phosphor is usually unnecessary. .
On the other hand, when the light emitting device of the present invention is configured as a white light emitting device, the first light emitter, the first phosphor (red phosphor), and the first phosphor so as to obtain desired white light. The two phosphors may be combined appropriately. Specifically, examples of preferable combinations of the first light emitter, the first phosphor, and the second phosphor in the case where the light emitting device of the present invention is configured as a white light emitting device include the following: (A) to (C) are included.

(A) A blue phosphor (such as a blue LED) is used as the first phosphor, a red phosphor (such as the phosphor of the present invention) is used as the first phosphor, and green fluorescence is used as the second phosphor. Body or yellow phosphor. Examples of the green phosphor include (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu phosphor, CaSc ₂ O ₄ : Ce phosphor, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce phosphor, and SrGa. ₂ S ₄ : Eu-based phosphor, M ₃ Si ₆ O ₁₂ N ₂ : Eu (where M represents an alkaline earth metal element) is preferably one or two or more green phosphors. . As the yellow phosphor, one or two selected from the group consisting of Y ₃ Al ₅ O ₁₂ : Ce phosphor, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu phosphor, and α-sialon phosphor More than one kind of yellow phosphor is preferred. A green phosphor and a yellow phosphor may be used in combination.

(B) A near ultraviolet light emitter (near ultraviolet LED or the like) is used as the first light emitter, a red phosphor (such as the phosphor of the present invention) is used as the first phosphor, and the second phosphor is used as the second phosphor. A blue phosphor and a green phosphor are used in combination. In this case, BaMgAl ₁₀ O ₁₇ : Eu and / or (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu are preferable as the blue phosphor. Also, as the green _{phosphor, BaMgAl 10 O 17: Eu,} Mn, (Ba, Sr, Ca, Mg) 2 SiO 4: Eu _{phosphor, (Ba, Sr, Ca)} 4 Al 14 O 25: Eu, One or two or more green phosphors selected from the group consisting of (Ba, Sr, Ca) Al ₂ O ₄ : Eu are preferable. Among them, a near-ultraviolet LED, the phosphor of the present invention, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu as a blue phosphor, and BaMgAl ₁₀ O as a green phosphor. ₁₇ : It is preferable to use Eu and Mn in combination.

(C) A blue phosphor (blue LED or the like) is used as the first phosphor, a red phosphor (such as the phosphor of the present invention) is used as the first phosphor, and orange fluorescence is used as the second phosphor. Use the body. In this case, (Sr, Ba) ₃ SiO ₅ : Eu is preferable as the orange phosphor.

  In addition, the phosphor of the present invention is mixed with other phosphors (here, mixing does not necessarily mean that the phosphors need to be mixed with each other, but means that different types of phosphors are combined). ) Can be used. In particular, when phosphors are mixed in the combination described above, a preferable phosphor mixture is obtained. In addition, there is no restriction | limiting in particular in the kind of fluorescent substance to mix, and its ratio.

[3-3. Sealing material]
In the light emitting device of the present invention, each phosphor used is usually used by being dispersed in a liquid medium which is a sealing material.
Examples of the liquid medium include [2-2. Examples thereof include those described in the section “Liquid medium”.
The liquid medium can contain a metal element that can be a metal oxide having a high refractive index in order to adjust the refractive index of the sealing member. Examples of metal elements that give a metal oxide having a high refractive index include Si, Al, Zr, Ti, Y, Nb, and B. These metal elements may be used alone or in combination of two or more in any combination and ratio.

The presence form of such a metal element is not particularly limited as long as the transparency of the sealing member is not impaired. For example, even if a uniform glass layer is formed as a metalloxane bond, the metal element is present in a particulate form in the sealing member. It may be. When present in the form of particles, the structure inside the particles may be either amorphous or crystalline, but is preferably a crystalline structure in order to provide a high refractive index. Further, the particle diameter is usually not more than the emission wavelength of the semiconductor light emitting device, preferably not more than 100 nm, more preferably not more than 50 nm, particularly preferably not more than 30 nm so as not to impair the transparency of the sealing member. For example, by mixing particles of metal oxide such as silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, niobium oxide, etc. with silicone material, the above metal elements are present in the sealing member in the form of particles Can be made.
The liquid medium may further contain known additives such as a diffusing agent, a filler, a viscosity modifier, and an ultraviolet absorber.

[3-4. Configuration of light emitting device (others)]
The light-emitting device of the present invention is not particularly limited as long as it includes the above-described excitation light source (first light emitter) and phosphor (second light emitter). The above-described excitation light source (first light emitter) and phosphor (second light emitter) are arranged. At this time, the phosphor (second illuminant) is excited by the light emission of the excitation light source (first illuminant) to generate light, and the emission and / or fluorescence of the excitation light source (first illuminant) is generated. It arrange | positions so that light emission of a body (2nd light-emitting body) may be taken out outside. Here, when using two or more kinds of phosphors, the phosphors are not necessarily mixed in the same layer. For example, the second phosphor is placed on the layer containing the first phosphor. You may make it contain a fluorescent substance in a separate layer for every color development of a fluorescent substance, such as a layer to contain is laminated | stacked.

  In the light emitting device of the present invention, members other than the above-described excitation light source (first light emitter), phosphor (second light emitter), and frame may be used. Examples thereof include the aforementioned sealing materials. In addition to the purpose of dispersing the phosphor (second light emitter) in the light emitting device, the sealing material is provided between the excitation light source (first light emitter), the phosphor (second light emitter), and the frame. It can be used for the purpose of bonding.

[3-5. Embodiment of Light Emitting Device]
Hereinafter, the light-emitting device of the present invention will be described in more detail with reference to specific embodiments. However, the present invention is not limited to the following embodiments, and does not depart from the gist of the present invention. It can be implemented with arbitrary modifications.

  FIG. 1 is a schematic perspective view showing a positional relationship between a first light emitter serving as an excitation light source and a second light emitter configured as a phosphor containing portion having a phosphor in an example of the light emitting device of the present invention. Shown in In FIG. 1, reference numeral 1 denotes a phosphor-containing portion (second light emitter), reference numeral 2 denotes a surface-emitting GaN-based LD as an excitation light source (first light emitter), and reference numeral 3 denotes a substrate. In order to create a state in which they are in contact with each other, LD (2) and phosphor-containing portion (second light emitter) (1) are produced separately, and their surfaces are brought into contact with each other by an adhesive or other means. Alternatively, the phosphor-containing portion (second light emitter) may be formed (molded) on the light emitting surface of the LD (2). As a result, the LD (2) and the phosphor-containing portion (second light emitter) (1) can be brought into contact with each other.

  When such an apparatus configuration is employed, the light loss is such that light from the excitation light source (first light emitter) is reflected by the film surface of the phosphor-containing portion (second light emitter) and oozes out. Therefore, the light emission efficiency of the entire device can be improved.

  FIG. 2A is a typical example of a light emitting device of a form generally referred to as a shell type, and has a light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the light emitting device (4), reference numeral 5 denotes a mount lead, reference numeral 6 denotes an inner lead, reference numeral 7 denotes an excitation light source (first light emitter), reference numeral 8 denotes a phosphor-containing portion, reference numeral 9 denotes a conductive wire, reference numeral 10 Indicates a mold member.

  FIG. 2B is a typical example of a light-emitting device of a form called a surface-mount type, and has light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the figure, reference numeral 22 is an excitation light source (first light emitter), reference numeral 23 is a phosphor-containing portion (second light emitter), reference numeral 24 is a frame, reference numeral 25 is a conductive wire, reference numerals 26 and 27 are electrodes. Respectively.

[3-6. Other matters concerning light emitting device]
All of the light emitting devices of the present invention described above use the excitation light source as described above as the excitation light source (first light emitter), and the red phosphor, green phosphor, and blue of the present invention as described above. A known phosphor such as a phosphor and a yellow phosphor can be used in any combination, and a known device configuration can be adopted to form a white light emitting device. Here, the white color of the white light emitting device means all of (yellowish) white, (greenish) white, (blueish) white, (purple) white and white defined by JIS Z8701. Of these, white is preferred.

[4. Application of light emitting device]
The application of the light-emitting device of the present invention is not particularly limited, and can be used in various fields in which ordinary light-emitting devices are used. Even if it suddenly stops emitting light for some reason, it can continue to emit light as a display element or light source, and it can be used for indoor and outdoor displays such as clock faces, road signs, emergency exits, etc. It can be used for the light source of an apparatus.

[4-1. Lighting device]
When the light-emitting device of the present invention is applied to a lighting device, the above-described light-emitting device may be appropriately incorporated into a known lighting device. For example, a surface emitting illumination device (11) incorporating the above-described light emitting device (4) as shown in FIG. 3 can be mentioned.

  FIG. 3 is a cross-sectional view schematically showing one embodiment of the illumination device of the present invention. As shown in FIG. 3, the surface-emitting illumination device has a number of light-emitting devices (13) (described above) on the bottom surface of a rectangular holding case (12) whose inner surface is light-opaque such as a white smooth surface. The light emitting device (4) corresponds to the lid portion of the holding case (12) by arranging a power source and a circuit (not shown) for driving the light emitting device (13) on the outside thereof. A diffuser plate (14) such as a milky white acrylic plate is fixed at a location for uniform light emission.

  Then, the surface emitting illumination device (11) is driven to apply light to the excitation light source (first light emitter) of the light emitting device (13) to emit light, and part of the light emission is converted into the phosphor. The phosphor in the containing part (second illuminant) absorbs and emits visible light. On the other hand, light emission with high color rendering is obtained by mixing with blue light or the like that is not absorbed by the phosphor. Is transmitted through the diffusion plate (14) and emitted upward in the drawing, so that illumination light with uniform brightness can be obtained within the surface of the diffusion plate (14) of the holding case (12).

[4-2. Image display device]
When the light emitting device of the present invention is used as a light source of an image display device, the specific configuration of the image display device is not limited, but it is preferably used with a color filter. For example, when the image display device is a color image display device using color liquid crystal display elements, the light emitting device is used as a backlight, a light shutter using liquid crystal, and a color filter having red, green, and blue pixels; By combining these, an image display device can be formed.

[4-3. Fluorescent paint and laminate using the same]
The phosphor of the present invention is dispersed in various organic solvents and / or binder resins such as acrylic resin, epoxy resin, polyimide resin, glass, and the like, and further added with additives as necessary, so that a fluorescent paint (hereinafter, as appropriate) It shall be called “fluorescent paint of the present invention”).

  The fluorescent paint of the present invention may contain only one kind of the phosphor of the present invention, or may contain two or more kinds in any combination and ratio. Further, the fluorescent paint of the present invention may contain a phosphor other than the phosphor of the present invention, and even in that case, may contain only one type of phosphor other than the phosphor of the present invention, Two or more kinds may be included in any combination and ratio.

  What is necessary is just to set arbitrarily content of the fluorescent substance in the fluorescent paint of this invention according to a well-known technique.

  The fluorescent paint can be applied to various labels / display boards, toys, etc., as described in the above-mentioned use of the phosphor. The fluorescent paint is applied on a substrate for each use and dried on the substrate. It can be set as the laminated body which laminated | stacked the fluorescent substance layer. In addition to the substrate and the phosphor layer, the laminated body may have other layers according to each application at an arbitrary place.

  The thickness of the phosphor layer at this time is usually 10 μm or more, preferably 100 μm or more, and is usually 5 mm or less, preferably 1 mm or less.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless departing from the gist thereof.

[Method of measuring afterglow]
Afterglow is measured by measuring a temporal change curve of afterglow intensity observed after blocking 450 nm irradiation excitation with a shutter (hereinafter referred to as afterglow intensity change curve), and then logarithmically expressed afterglow intensity. In detail (hereinafter referred to as logarithmic afterglow intensity change). This measurement was performed at room temperature using the Hitachi spectrofluorometer F-4500 with the FL Solution program according to the following experimental procedure.

  After starting the program, change the measurement mode to time in [General] on the condition setting screen. In [Apparatus], the data mode is fluorescence, the excitation wavelength is 450 nm, the fluorescence wavelength is 600 nm, the measurement time is 9999 ms, and the initial waiting time is 0 s. The excitation side slit was 10.0 nm, the light receiving side slit was 10.0 nm, the photomultiplier voltage was 400 V, the response was 2.0 s, and the measurement was repeated once.

After filling the sample holder into the sample holder, place it in the measurement site, and then press the shutter open / close button on the toolbar at the right end of the measurement screen to open the shutter, and confirm that the numerical value is counted on the fluorescence intensity monitor Then, the measurement start button was pressed to start the measurement, and after a few seconds, the shutter was closed and the afterglow intensity change curve was recorded.
The afterglow intensity measured in each sample was subjected to logarithmic display processing to create a logarithmic afterglow intensity change curve.

Example 1
0.29 g of Ca ₃ N ₂ (manufactured by CERAC, purity 99%) 0.29 g, so that each raw material charged composition of the phosphor is (Ca _0.99 Eu _0.005 Tm _0.005 ) ₂ Si ₅ N _{8 2} O ₃ (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%) 5.3 mg, Tm ₂ O ₃ (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%) 5.8 mg, and α-Si ₃ N ₄ (manufactured by Ube Industries, Ltd.) SN-E10) 0.70 g was weighed in a glow box filled with nitrogen gas, and these raw material powders were put in an agate mortar and mixed by a dry mixing method until uniform. The mixture thus obtained was placed in a boron nitride crucible and tightly packed. This boron nitride crucible was placed in a resistance heating type reducing atmosphere thermal firing furnace (manufactured). The reducing atmosphere at this time is under atmospheric pressure while flowing nitrogen gas at a flow rate of 3.5 (l / min) and Ar—H ₂ mixed gas (H ₂ = 5 vol%) at 0.5 (l / min). Firing was performed at 1,400 ° C. for 8 hours.

Comparative Example 1
The raw materials were mixed and fired at 1350 ° C. for 5 hours so as to be (Ca _0.9775 Eu _0.0075 Tm _0.015 ) ₂ Si ₅ N ₈ having the same composition as that of JP-A-2004-10786. Here, although the firing atmosphere described in the publication is an ammonia atmosphere, the ammonia gas is decomposed into N ₂ and H ₂ gas at 1350 ° C., so in Example 1 instead of ammonia gas. Firing was performed in a reducing atmosphere using the indicated nitrogen gas and mixed gas.

Example 2, Comparative Example 2 and Comparative Example 3
A phosphor was manufactured in the same manner as in Example 1 except that the amounts of Eu and Tm were changed as shown in Table 1.

Example 3
The composition of the phosphor was the same as in Example 1, and the firing conditions were changed to produce a phosphor.

That is, a boron nitride crucible containing a mixed sample was placed in a resistance heating vacuum pressurizing atmosphere furnace (manufactured by Fuji Denpa Kogyo Co., Ltd.) and heated from room temperature to 800 ° C. under a reduced pressure of <5 × 10 ⁻³ Pa. Vacuum heating was performed at 20 ° C./min. When the temperature reached 800 ° C., the temperature was maintained and high-purity nitrogen gas (99.9995%) was introduced for 30 minutes until the pressure became 0.92 MPa, and then the temperature was further increased while maintaining 0.92 MPa. The temperature was raised to 1200 ° C. at a rate of 20 ° C./min. The temperature was maintained for 5 minutes, the thermocouple was changed to a radiation thermometer, and further heated to 1600 ° C. at a rate of temperature increase of 20 ° C./min. When the temperature reached 1600 ° C., the temperature was maintained for 2 hours. Furthermore, it heated to 1800 degreeC with the temperature increase rate of 20 degreeC / min, and when it reached 1800 degreeC, it hold | maintained for 2 hours. Thereafter, it was cooled to 1200 ° C. at a temperature lowering rate of 20 ° C./min, then allowed to cool, and pulverized in an alumina mortar to obtain a phosphor.

  The emission peak wavelength of this phosphor when excited with light having a wavelength of 455 nm is 602 nm, and the relative emission peak intensity of LP-B4 manufactured by Kasei Optonix Co., Ltd. when the wavelength intensity at excitation of 365 nm is 100 is 24. there were. These values are obtained from the emission spectrum measured as follows.

  The emission spectrum was measured using a 150 W xenon lamp as an excitation light source and a fluorescence measuring device (manufactured by JASCO Corporation) equipped with a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring device. The light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 455 nm was irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of the excitation light is dispersed by a diffraction grating spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm to 800 nm, and a personal computer is used. The emission spectrum was measured through signal processing such as sensitivity correction. During the measurement, the slit width of the light-receiving side spectroscope was set to 1 nm.

Further, the ratio (I _10min / I) of the emission intensity at the time when 10 minutes had elapsed after the interruption to the emission intensity immediately after the irradiation excitation interruption was 0.002.

<Evaluation of persistence>
The afterglow was measured by the above-described measurement method for the fired products obtained in the above Examples and Comparative Examples. The logarithmic afterglow intensity change curve is shown in FIG.
Here, in order to compare the shapes of the logarithmic afterglow intensity change curves of the respective examples and comparative examples, the logarithmic afterglow intensity change curve is obtained by changing the initial afterglow intensity to the initial afterglow intensity obtained in Example 3. It was described together.

  From this result, in all of the phosphors of the comparative examples, the logarithmic afterglow intensity change decreases linearly with respect to time, but the phosphor of the present application deviates from the straight line, and Eu, Tm concentration, and Eu / Tm ratio It has been clarified that it has excellent afterglow characteristics by optimizing and improving the firing conditions.

Examples 4-7
A phosphor was obtained in the same manner as in Example 3 except that the values of x and y were changed as shown in Table 2.
Table 2 shows the emission peak wavelength, relative emission peak intensity, and I _10min / I measured for these phosphors in the same manner as in Example 3. In Table 2, the results of Example 3 are also shown.

From the above results, it can be seen that the phosphor of the present invention in which the values of x and y are in a specific range have high values in terms of the emission peak intensity value and I _{10 min} / I.

Examples 8-12 and Comparative Example 4
A phosphor was obtained in the same manner as in Example 3 except that the values of x and y were changed as shown in Table 3.
Table 3 shows the emission peak wavelength, relative emission peak intensity, and I _10min / I measured for these phosphors in the same manner as in Example 3.
Moreover, the logarithmic afterglow intensity change curve regarding the fluorescent substance of Example 8 is shown in FIG.

From the above results, the phosphors of Examples 8 to 12 are inferior in emission peak intensity as compared with Examples 3 to 7, but the value of I _10min / I is very high, and the afterglow characteristics are as follows. It turns out that it has become more excellent.

  The red phosphor of the present invention has a high persistence and is particularly suitable for use as a phosphorescent phosphor.

It is a typical perspective view which shows the positional relationship of an excitation light source (1st light emission body) and a fluorescent substance containing part (2nd light emission body) in an example of the light-emitting device of this invention. 2 (a) and 2 (b) are schematic views showing an embodiment of a light emitting device having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is sectional drawing. It is sectional drawing which shows typically one Embodiment of the illuminating device of this invention. It is a figure which shows the logarithmic persistence intensity change curve about the fluorescent substance of Examples 1-3 and 8 and Comparative Examples 1-3.

Explanation of symbols

1: Second light emitter 2: Surface-emitting GaN-based LD
3: Substrate 4: Light emitting device 5: Mount lead 6: Inner lead 7: First light emitter 8: Phosphor containing portion 9: Conductive wire 10: Mold member 11: Surface light emitting illumination device 12: Holding case 13: Light emission Device 14: Diffuser 22: First light emitter 23: Phosphor-containing portion 24: Frame 25: Conductive wire 26: Electrode 27: Electrode

Claims (7)

A phosphor represented by the following formula (I):
Eu _2x Tm _2y (Mg, Ca, Sr, Ba) _2-2x-2y Si ₅ X ₈ (I)
(In the formula (I), X represents one or more elements selected from the group consisting of nitrogen and oxygen, and x and y are positive numbers satisfying any of the following (i) and (ii), respectively. Indicates.
(i) 0 <x ≦ 0.02
0.5 <x / y <2
(ii) 0.0005 ≦ x <0.005
x + y <0.025)   A phosphor-containing composition comprising the phosphor according to claim 1 and a liquid medium. A first light emitter, and a second light emitter that emits visible light when irradiated with light from the first light emitter,
The light emitting device, wherein the second light emitter contains one or more of the phosphors according to claim 1 as a first phosphor.   The illuminating device which has a light-emitting device of Claim 3.   An image display device comprising the light emitting device according to claim 3.   A fluorescent paint containing the phosphor according to claim 1.   A laminate obtained by applying the fluorescent paint according to claim 6 to a substrate.

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